182 files changed, 0 insertions, 137566 deletions

diff --git a/lib/libcxx/include/CMakeLists.txt b/lib/libcxx/include/CMakeLists.txt
deleted file mode 100644
index 73f7cfc4d8e..00000000000
--- a/lib/libcxx/include/CMakeLists.txt
+++ /dev/null
@@ -1,273 +0,0 @@
-set(files
-  __bit_reference
-  __bsd_locale_defaults.h
-  __bsd_locale_fallbacks.h
-  __errc
-  __debug
-  __functional_03
-  __functional_base
-  __functional_base_03
-  __hash_table
-  __libcpp_version
-  __locale
-  __mutex_base
-  __node_handle
-  __nullptr
-  __split_buffer
-  __sso_allocator
-  __std_stream
-  __string
-  __threading_support
-  __tree
-  __tuple
-  __undef_macros
-  algorithm
-  any
-  array
-  atomic
-  bit
-  bitset
-  cassert
-  ccomplex
-  cctype
-  cerrno
-  cfenv
-  cfloat
-  charconv
-  chrono
-  cinttypes
-  ciso646
-  climits
-  clocale
-  cmath
-  codecvt
-  compare
-  complex
-  complex.h
-  condition_variable
-  csetjmp
-  csignal
-  cstdarg
-  cstdbool
-  cstddef
-  cstdint
-  cstdio
-  cstdlib
-  cstring
-  ctgmath
-  ctime
-  ctype.h
-  cwchar
-  cwctype
-  deque
-  errno.h
-  exception
-  experimental/__config
-  experimental/__memory
-  experimental/algorithm
-  experimental/any
-  experimental/chrono
-  experimental/coroutine
-  experimental/deque
-  experimental/filesystem
-  experimental/forward_list
-  experimental/functional
-  experimental/iterator
-  experimental/list
-  experimental/map
-  experimental/memory_resource
-  experimental/numeric
-  experimental/optional
-  experimental/propagate_const
-  experimental/ratio
-  experimental/regex
-  experimental/set
-  experimental/simd
-  experimental/string
-  experimental/string_view
-  experimental/system_error
-  experimental/tuple
-  experimental/type_traits
-  experimental/unordered_map
-  experimental/unordered_set
-  experimental/utility
-  experimental/vector
-  ext/__hash
-  ext/hash_map
-  ext/hash_set
-  filesystem
-  float.h
-  forward_list
-  fstream
-  functional
-  future
-  initializer_list
-  inttypes.h
-  iomanip
-  ios
-  iosfwd
-  iostream
-  istream
-  iterator
-  limits
-  limits.h
-  list
-  locale
-  locale.h
-  map
-  math.h
-  memory
-  module.modulemap
-  mutex
-  new
-  numeric
-  optional
-  ostream
-  queue
-  random
-  ratio
-  regex
-  scoped_allocator
-  set
-  setjmp.h
-  shared_mutex
-  span
-  sstream
-  stack
-  stdbool.h
-  stddef.h
-  stdexcept
-  stdint.h
-  stdio.h
-  stdlib.h
-  streambuf
-  string
-  string.h
-  string_view
-  strstream
-  system_error
-  tgmath.h
-  thread
-  tuple
-  type_traits
-  typeindex
-  typeinfo
-  unordered_map
-  unordered_set
-  utility
-  valarray
-  variant
-  vector
-  version
-  wchar.h
-  wctype.h
-  )
-
-if(LIBCXX_INSTALL_SUPPORT_HEADERS)
-  set(files
-    ${files}
-    support/android/locale_bionic.h
-    support/fuchsia/xlocale.h
-    support/ibm/limits.h
-    support/ibm/locale_mgmt_aix.h
-    support/ibm/support.h
-    support/ibm/xlocale.h
-    support/musl/xlocale.h
-    support/newlib/xlocale.h
-    support/solaris/floatingpoint.h
-    support/solaris/wchar.h
-    support/solaris/xlocale.h
-    support/win32/limits_msvc_win32.h
-    support/win32/locale_win32.h
-    support/xlocale/__nop_locale_mgmt.h
-    support/xlocale/__posix_l_fallback.h
-    support/xlocale/__strtonum_fallback.h
-    support/xlocale/xlocale.h
-    )
-endif()
-
-if (LIBCXX_NEEDS_SITE_CONFIG)
-  # Generate a custom __config header. The new header is created
-  # by prepending __config_site to the current __config header.
-  add_custom_command(OUTPUT ${LIBCXX_BINARY_DIR}/__generated_config
-    COMMAND ${PYTHON_EXECUTABLE} ${LIBCXX_SOURCE_DIR}/utils/cat_files.py
-      ${LIBCXX_BINARY_DIR}/__config_site
-      ${LIBCXX_SOURCE_DIR}/include/__config
-      -o ${LIBCXX_BINARY_DIR}/__generated_config
-    DEPENDS ${LIBCXX_SOURCE_DIR}/include/__config
-            ${LIBCXX_BINARY_DIR}/__config_site
-  )
-  # Add a target that executes the generation commands.
-  add_custom_target(cxx-generated-config ALL
-    DEPENDS ${LIBCXX_BINARY_DIR}/__generated_config)
-  set(generated_config_deps cxx-generated-config)
-else()
-  set(files
-    ${files}
-    __config
-    )
-endif()
-
-if(NOT LIBCXX_USING_INSTALLED_LLVM AND LIBCXX_HEADER_DIR)
-  set(output_dir ${LIBCXX_HEADER_DIR}/include/c++/v1)
-
-  set(out_files)
-  foreach(f ${files})
-    set(src ${CMAKE_CURRENT_SOURCE_DIR}/${f})
-    set(dst ${output_dir}/${f})
-    add_custom_command(OUTPUT ${dst}
-      DEPENDS ${src}
-      COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src} ${dst}
-      COMMENT "Copying CXX header ${f}")
-    list(APPEND out_files ${dst})
-  endforeach()
-
-  if (LIBCXX_NEEDS_SITE_CONFIG)
-    # Copy the generated header as __config into build directory.
-    set(src ${LIBCXX_BINARY_DIR}/__generated_config)
-    set(dst ${output_dir}/__config)
-    add_custom_command(OUTPUT ${dst}
-        DEPENDS ${src} ${generated_config_deps}
-        COMMAND ${CMAKE_COMMAND} -E copy_if_different ${src} ${dst}
-        COMMENT "Copying CXX __config")
-    list(APPEND out_files ${dst})
-  endif()
-
-  add_custom_target(cxx-headers ALL DEPENDS ${out_files} ${LIBCXX_CXX_ABI_HEADER_TARGET})
-else()
-  add_custom_target(cxx-headers)
-endif()
-set_target_properties(cxx-headers PROPERTIES FOLDER "Misc")
-
-if (LIBCXX_INSTALL_HEADERS)
-  foreach(file ${files})
-    get_filename_component(dir ${file} DIRECTORY)
-    install(FILES ${file}
-      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1/${dir}
-      COMPONENT cxx-headers
-      PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
-    )
-  endforeach()
-
-  if (LIBCXX_NEEDS_SITE_CONFIG)
-    # Install the generated header as __config.
-    install(FILES ${LIBCXX_BINARY_DIR}/__generated_config
-      DESTINATION ${LIBCXX_INSTALL_HEADER_PREFIX}include/c++/v1
-      PERMISSIONS OWNER_READ OWNER_WRITE GROUP_READ WORLD_READ
-      RENAME __config
-      COMPONENT cxx-headers)
-  endif()
-
-  if (NOT CMAKE_CONFIGURATION_TYPES)
-    add_custom_target(install-cxx-headers
-                      DEPENDS cxx-headers ${generated_config_deps}
-                      COMMAND "${CMAKE_COMMAND}"
-                              -DCMAKE_INSTALL_COMPONENT=cxx-headers
-                              -P "${CMAKE_BINARY_DIR}/cmake_install.cmake")
-    # Stripping is a no-op for headers
-    add_custom_target(install-cxx-headers-stripped DEPENDS install-cxx-headers)
-
-    add_custom_target(install-libcxx-headers DEPENDS install-cxx-headers)
-    add_custom_target(install-libcxx-headers-stripped DEPENDS install-cxx-headers-stripped)
-  endif()
-endif()
diff --git a/lib/libcxx/include/__bit_reference b/lib/libcxx/include/__bit_reference
deleted file mode 100644
index c208af2b4d7..00000000000
--- a/lib/libcxx/include/__bit_reference
+++ /dev/null
@@ -1,1281 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___BIT_REFERENCE
-#define _LIBCPP___BIT_REFERENCE
-
-#include <__config>
-#include <bit>
-#include <algorithm>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Cp, bool _IsConst, typename _Cp::__storage_type = 0> class __bit_iterator;
-template <class _Cp> class __bit_const_reference;
-
-template <class _Tp>
-struct __has_storage_type
-{
-    static const bool value = false;
-};
-
-template <class _Cp, bool = __has_storage_type<_Cp>::value>
-class __bit_reference
-{
-    typedef typename _Cp::__storage_type    __storage_type;
-    typedef typename _Cp::__storage_pointer __storage_pointer;
-
-    __storage_pointer __seg_;
-    __storage_type    __mask_;
-
-    friend typename _Cp::__self;
-
-    friend class __bit_const_reference<_Cp>;
-    friend class __bit_iterator<_Cp, false>;
-public:
-    _LIBCPP_INLINE_VISIBILITY operator bool() const _NOEXCEPT
-        {return static_cast<bool>(*__seg_ & __mask_);}
-    _LIBCPP_INLINE_VISIBILITY bool operator ~() const _NOEXCEPT
-        {return !static_cast<bool>(*this);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __bit_reference& operator=(bool __x) _NOEXCEPT
-    {
-        if (__x)
-            *__seg_ |= __mask_;
-        else
-            *__seg_ &= ~__mask_;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __bit_reference& operator=(const __bit_reference& __x) _NOEXCEPT
-        {return operator=(static_cast<bool>(__x));}
-
-    _LIBCPP_INLINE_VISIBILITY void flip() _NOEXCEPT {*__seg_ ^= __mask_;}
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator<_Cp, false> operator&() const _NOEXCEPT
-        {return __bit_iterator<_Cp, false>(__seg_, static_cast<unsigned>(__ctz(__mask_)));}
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    __bit_reference(__storage_pointer __s, __storage_type __m) _NOEXCEPT
-        : __seg_(__s), __mask_(__m) {}
-};
-
-template <class _Cp>
-class __bit_reference<_Cp, false>
-{
-};
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__bit_reference<_Cp> __x, __bit_reference<_Cp> __y) _NOEXCEPT
-{
-    bool __t = __x;
-    __x = __y;
-    __y = __t;
-}
-
-template <class _Cp, class _Dp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__bit_reference<_Cp> __x, __bit_reference<_Dp> __y) _NOEXCEPT
-{
-    bool __t = __x;
-    __x = __y;
-    __y = __t;
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__bit_reference<_Cp> __x, bool& __y) _NOEXCEPT
-{
-    bool __t = __x;
-    __x = __y;
-    __y = __t;
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(bool& __x, __bit_reference<_Cp> __y) _NOEXCEPT
-{
-    bool __t = __x;
-    __x = __y;
-    __y = __t;
-}
-
-template <class _Cp>
-class __bit_const_reference
-{
-    typedef typename _Cp::__storage_type          __storage_type;
-    typedef typename _Cp::__const_storage_pointer __storage_pointer;
-
-    __storage_pointer        __seg_;
-    __storage_type __mask_;
-
-    friend typename _Cp::__self;
-    friend class __bit_iterator<_Cp, true>;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __bit_const_reference(const __bit_reference<_Cp>& __x) _NOEXCEPT
-        : __seg_(__x.__seg_), __mask_(__x.__mask_) {}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR operator bool() const _NOEXCEPT
-        {return static_cast<bool>(*__seg_ & __mask_);}
-
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator<_Cp, true> operator&() const _NOEXCEPT
-        {return __bit_iterator<_Cp, true>(__seg_, static_cast<unsigned>(__ctz(__mask_)));}
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR
-    __bit_const_reference(__storage_pointer __s, __storage_type __m) _NOEXCEPT
-        : __seg_(__s), __mask_(__m) {}
-
-    __bit_const_reference& operator=(const __bit_const_reference& __x);
-};
-
-// find
-
-template <class _Cp, bool _IsConst>
-__bit_iterator<_Cp, _IsConst>
-__find_bool_true(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
-{
-    typedef __bit_iterator<_Cp, _IsConst> _It;
-    typedef typename _It::__storage_type __storage_type;
-    static const int __bits_per_word = _It::__bits_per_word;
-    // do first partial word
-    if (__first.__ctz_ != 0)
-    {
-        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
-        __storage_type __dn = _VSTD::min(__clz_f, __n);
-        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-        __storage_type __b = *__first.__seg_ & __m;
-        if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
-        if (__n == __dn)
-            return __first + __n;
-        __n -= __dn;
-        ++__first.__seg_;
-    }
-    // do middle whole words
-    for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
-        if (*__first.__seg_)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(*__first.__seg_)));
-    // do last partial word
-    if (__n > 0)
-    {
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        __storage_type __b = *__first.__seg_ & __m;
-        if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
-    }
-    return _It(__first.__seg_, static_cast<unsigned>(__n));
-}
-
-template <class _Cp, bool _IsConst>
-__bit_iterator<_Cp, _IsConst>
-__find_bool_false(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
-{
-    typedef __bit_iterator<_Cp, _IsConst> _It;
-    typedef typename _It::__storage_type __storage_type;
-    const int __bits_per_word = _It::__bits_per_word;
-    // do first partial word
-    if (__first.__ctz_ != 0)
-    {
-        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
-        __storage_type __dn = _VSTD::min(__clz_f, __n);
-        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-        __storage_type __b = ~*__first.__seg_ & __m;
-        if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
-        if (__n == __dn)
-            return __first + __n;
-        __n -= __dn;
-        ++__first.__seg_;
-    }
-    // do middle whole words
-    for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
-    {
-        __storage_type __b = ~*__first.__seg_;
-        if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
-    }
-    // do last partial word
-    if (__n > 0)
-    {
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        __storage_type __b = ~*__first.__seg_ & __m;
-        if (__b)
-            return _It(__first.__seg_, static_cast<unsigned>(_VSTD::__ctz(__b)));
-    }
-    return _It(__first.__seg_, static_cast<unsigned>(__n));
-}
-
-template <class _Cp, bool _IsConst, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__bit_iterator<_Cp, _IsConst>
-find(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, const _Tp& __value_)
-{
-    if (static_cast<bool>(__value_))
-        return __find_bool_true(__first, static_cast<typename _Cp::size_type>(__last - __first));
-    return __find_bool_false(__first, static_cast<typename _Cp::size_type>(__last - __first));
-}
-
-// count
-
-template <class _Cp, bool _IsConst>
-typename __bit_iterator<_Cp, _IsConst>::difference_type
-__count_bool_true(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
-{
-    typedef __bit_iterator<_Cp, _IsConst> _It;
-    typedef typename _It::__storage_type __storage_type;
-    typedef typename _It::difference_type difference_type;
-    const int __bits_per_word = _It::__bits_per_word;
-    difference_type __r = 0;
-    // do first partial word
-    if (__first.__ctz_ != 0)
-    {
-        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
-        __storage_type __dn = _VSTD::min(__clz_f, __n);
-        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-        __r = _VSTD::__popcount(*__first.__seg_ & __m);
-        __n -= __dn;
-        ++__first.__seg_;
-    }
-    // do middle whole words
-    for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
-        __r += _VSTD::__popcount(*__first.__seg_);
-    // do last partial word
-    if (__n > 0)
-    {
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        __r += _VSTD::__popcount(*__first.__seg_ & __m);
-    }
-    return __r;
-}
-
-template <class _Cp, bool _IsConst>
-typename __bit_iterator<_Cp, _IsConst>::difference_type
-__count_bool_false(__bit_iterator<_Cp, _IsConst> __first, typename _Cp::size_type __n)
-{
-    typedef __bit_iterator<_Cp, _IsConst> _It;
-    typedef typename _It::__storage_type __storage_type;
-    typedef typename _It::difference_type difference_type;
-    const int __bits_per_word = _It::__bits_per_word;
-    difference_type __r = 0;
-    // do first partial word
-    if (__first.__ctz_ != 0)
-    {
-        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
-        __storage_type __dn = _VSTD::min(__clz_f, __n);
-        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-        __r = _VSTD::__popcount(~*__first.__seg_ & __m);
-        __n -= __dn;
-        ++__first.__seg_;
-    }
-    // do middle whole words
-    for (; __n >= __bits_per_word; ++__first.__seg_, __n -= __bits_per_word)
-        __r += _VSTD::__popcount(~*__first.__seg_);
-    // do last partial word
-    if (__n > 0)
-    {
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        __r += _VSTD::__popcount(~*__first.__seg_ & __m);
-    }
-    return __r;
-}
-
-template <class _Cp, bool _IsConst, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __bit_iterator<_Cp, _IsConst>::difference_type
-count(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, const _Tp& __value_)
-{
-    if (static_cast<bool>(__value_))
-        return __count_bool_true(__first, static_cast<typename _Cp::size_type>(__last - __first));
-    return __count_bool_false(__first, static_cast<typename _Cp::size_type>(__last - __first));
-}
-
-// fill_n
-
-template <class _Cp>
-void
-__fill_n_false(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n)
-{
-    typedef __bit_iterator<_Cp, false> _It;
-    typedef typename _It::__storage_type __storage_type;
-    const int __bits_per_word = _It::__bits_per_word;
-    // do first partial word
-    if (__first.__ctz_ != 0)
-    {
-        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
-        __storage_type __dn = _VSTD::min(__clz_f, __n);
-        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-        *__first.__seg_ &= ~__m;
-        __n -= __dn;
-        ++__first.__seg_;
-    }
-    // do middle whole words
-    __storage_type __nw = __n / __bits_per_word;
-    _VSTD::memset(_VSTD::__to_raw_pointer(__first.__seg_), 0, __nw * sizeof(__storage_type));
-    __n -= __nw * __bits_per_word;
-    // do last partial word
-    if (__n > 0)
-    {
-        __first.__seg_ += __nw;
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        *__first.__seg_ &= ~__m;
-    }
-}
-
-template <class _Cp>
-void
-__fill_n_true(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n)
-{
-    typedef __bit_iterator<_Cp, false> _It;
-    typedef typename _It::__storage_type __storage_type;
-    const int __bits_per_word = _It::__bits_per_word;
-    // do first partial word
-    if (__first.__ctz_ != 0)
-    {
-        __storage_type __clz_f = static_cast<__storage_type>(__bits_per_word - __first.__ctz_);
-        __storage_type __dn = _VSTD::min(__clz_f, __n);
-        __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-        *__first.__seg_ |= __m;
-        __n -= __dn;
-        ++__first.__seg_;
-    }
-    // do middle whole words
-    __storage_type __nw = __n / __bits_per_word;
-    _VSTD::memset(_VSTD::__to_raw_pointer(__first.__seg_), -1, __nw * sizeof(__storage_type));
-    __n -= __nw * __bits_per_word;
-    // do last partial word
-    if (__n > 0)
-    {
-        __first.__seg_ += __nw;
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        *__first.__seg_ |= __m;
-    }
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-fill_n(__bit_iterator<_Cp, false> __first, typename _Cp::size_type __n, bool __value_)
-{
-    if (__n > 0)
-    {
-        if (__value_)
-            __fill_n_true(__first, __n);
-        else
-            __fill_n_false(__first, __n);
-    }
-}
-
-// fill
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-fill(__bit_iterator<_Cp, false> __first, __bit_iterator<_Cp, false> __last, bool __value_)
-{
-    _VSTD::fill_n(__first, static_cast<typename _Cp::size_type>(__last - __first), __value_);
-}
-
-// copy
-
-template <class _Cp, bool _IsConst>
-__bit_iterator<_Cp, false>
-__copy_aligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
-                                                     __bit_iterator<_Cp, false> __result)
-{
-    typedef __bit_iterator<_Cp, _IsConst> _In;
-    typedef  typename _In::difference_type difference_type;
-    typedef typename _In::__storage_type __storage_type;
-    const int __bits_per_word = _In::__bits_per_word;
-    difference_type __n = __last - __first;
-    if (__n > 0)
-    {
-        // do first word
-        if (__first.__ctz_ != 0)
-        {
-            unsigned __clz = __bits_per_word - __first.__ctz_;
-            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz), __n);
-            __n -= __dn;
-            __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz - __dn));
-            __storage_type __b = *__first.__seg_ & __m;
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b;
-            __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word;
-            __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word);
-            ++__first.__seg_;
-            // __first.__ctz_ = 0;
-        }
-        // __first.__ctz_ == 0;
-        // do middle words
-        __storage_type __nw = __n / __bits_per_word;
-        _VSTD::memmove(_VSTD::__to_raw_pointer(__result.__seg_),
-                       _VSTD::__to_raw_pointer(__first.__seg_),
-                       __nw * sizeof(__storage_type));
-        __n -= __nw * __bits_per_word;
-        __result.__seg_ += __nw;
-        // do last word
-        if (__n > 0)
-        {
-            __first.__seg_ += __nw;
-            __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-            __storage_type __b = *__first.__seg_ & __m;
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b;
-            __result.__ctz_ = static_cast<unsigned>(__n);
-        }
-    }
-    return __result;
-}
-
-template <class _Cp, bool _IsConst>
-__bit_iterator<_Cp, false>
-__copy_unaligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
-                                                       __bit_iterator<_Cp, false> __result)
-{
-    typedef __bit_iterator<_Cp, _IsConst> _In;
-    typedef  typename _In::difference_type difference_type;
-    typedef typename _In::__storage_type __storage_type;
-    static const int __bits_per_word = _In::__bits_per_word;
-    difference_type __n = __last - __first;
-    if (__n > 0)
-    {
-        // do first word
-        if (__first.__ctz_ != 0)
-        {
-            unsigned __clz_f = __bits_per_word - __first.__ctz_;
-            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz_f), __n);
-            __n -= __dn;
-            __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-            __storage_type __b = *__first.__seg_ & __m;
-            unsigned __clz_r = __bits_per_word - __result.__ctz_;
-            __storage_type __ddn = _VSTD::min<__storage_type>(__dn, __clz_r);
-            __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __ddn));
-            *__result.__seg_ &= ~__m;
-            if (__result.__ctz_ > __first.__ctz_)
-                *__result.__seg_ |= __b << (__result.__ctz_ - __first.__ctz_);
-            else
-                *__result.__seg_ |= __b >> (__first.__ctz_ - __result.__ctz_);
-            __result.__seg_ += (__ddn + __result.__ctz_) / __bits_per_word;
-            __result.__ctz_ = static_cast<unsigned>((__ddn + __result.__ctz_)  % __bits_per_word);
-            __dn -= __ddn;
-            if (__dn > 0)
-            {
-                __m = ~__storage_type(0) >> (__bits_per_word - __dn);
-                *__result.__seg_ &= ~__m;
-                *__result.__seg_ |= __b >> (__first.__ctz_ + __ddn);
-                __result.__ctz_ = static_cast<unsigned>(__dn);
-            }
-            ++__first.__seg_;
-            // __first.__ctz_ = 0;
-        }
-        // __first.__ctz_ == 0;
-        // do middle words
-        unsigned __clz_r = __bits_per_word - __result.__ctz_;
-        __storage_type __m = ~__storage_type(0) << __result.__ctz_;
-        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first.__seg_)
-        {
-            __storage_type __b = *__first.__seg_;
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b << __result.__ctz_;
-            ++__result.__seg_;
-            *__result.__seg_ &= __m;
-            *__result.__seg_ |= __b >> __clz_r;
-        }
-        // do last word
-        if (__n > 0)
-        {
-            __m = ~__storage_type(0) >> (__bits_per_word - __n);
-            __storage_type __b = *__first.__seg_ & __m;
-            __storage_type __dn = _VSTD::min(__n, static_cast<difference_type>(__clz_r));
-            __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __dn));
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b << __result.__ctz_;
-            __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word;
-            __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word);
-            __n -= __dn;
-            if (__n > 0)
-            {
-                __m = ~__storage_type(0) >> (__bits_per_word - __n);
-                *__result.__seg_ &= ~__m;
-                *__result.__seg_ |= __b >> __dn;
-                __result.__ctz_ = static_cast<unsigned>(__n);
-            }
-        }
-    }
-    return __result;
-}
-
-template <class _Cp, bool _IsConst>
-inline _LIBCPP_INLINE_VISIBILITY
-__bit_iterator<_Cp, false>
-copy(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
-{
-    if (__first.__ctz_ == __result.__ctz_)
-        return __copy_aligned(__first, __last, __result);
-    return __copy_unaligned(__first, __last, __result);
-}
-
-// copy_backward
-
-template <class _Cp, bool _IsConst>
-__bit_iterator<_Cp, false>
-__copy_backward_aligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
-                                                     __bit_iterator<_Cp, false> __result)
-{
-    typedef __bit_iterator<_Cp, _IsConst> _In;
-    typedef  typename _In::difference_type difference_type;
-    typedef typename _In::__storage_type __storage_type;
-    const int __bits_per_word = _In::__bits_per_word;
-    difference_type __n = __last - __first;
-    if (__n > 0)
-    {
-        // do first word
-        if (__last.__ctz_ != 0)
-        {
-            difference_type __dn = _VSTD::min(static_cast<difference_type>(__last.__ctz_), __n);
-            __n -= __dn;
-            unsigned __clz = __bits_per_word - __last.__ctz_;
-            __storage_type __m = (~__storage_type(0) << (__last.__ctz_ - __dn)) & (~__storage_type(0) >> __clz);
-            __storage_type __b = *__last.__seg_ & __m;
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b;
-            __result.__ctz_ = static_cast<unsigned>(((-__dn & (__bits_per_word - 1)) +
-                                                       __result.__ctz_)  % __bits_per_word);
-            // __last.__ctz_ = 0
-         }
-        // __last.__ctz_ == 0 || __n == 0
-        // __result.__ctz_ == 0 || __n == 0
-        // do middle words
-        __storage_type __nw = __n / __bits_per_word;
-        __result.__seg_ -= __nw;
-        __last.__seg_ -= __nw;
-        _VSTD::memmove(_VSTD::__to_raw_pointer(__result.__seg_),
-                       _VSTD::__to_raw_pointer(__last.__seg_),
-                       __nw * sizeof(__storage_type));
-        __n -= __nw * __bits_per_word;
-        // do last word
-        if (__n > 0)
-        {
-            __storage_type __m = ~__storage_type(0) << (__bits_per_word - __n);
-            __storage_type __b = *--__last.__seg_ & __m;
-            *--__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b;
-            __result.__ctz_ = static_cast<unsigned>(-__n & (__bits_per_word - 1));
-        }
-    }
-    return __result;
-}
-
-template <class _Cp, bool _IsConst>
-__bit_iterator<_Cp, false>
-__copy_backward_unaligned(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last,
-                                                       __bit_iterator<_Cp, false> __result)
-{
-    typedef __bit_iterator<_Cp, _IsConst> _In;
-    typedef  typename _In::difference_type difference_type;
-    typedef typename _In::__storage_type __storage_type;
-    const int __bits_per_word = _In::__bits_per_word;
-    difference_type __n = __last - __first;
-    if (__n > 0)
-    {
-        // do first word
-        if (__last.__ctz_ != 0)
-        {
-            difference_type __dn = _VSTD::min(static_cast<difference_type>(__last.__ctz_), __n);
-            __n -= __dn;
-            unsigned __clz_l = __bits_per_word - __last.__ctz_;
-            __storage_type __m = (~__storage_type(0) << (__last.__ctz_ - __dn)) & (~__storage_type(0) >> __clz_l);
-            __storage_type __b = *__last.__seg_ & __m;
-            unsigned __clz_r = __bits_per_word - __result.__ctz_;
-            __storage_type __ddn = _VSTD::min(__dn, static_cast<difference_type>(__result.__ctz_));
-            if (__ddn > 0)
-            {
-                __m = (~__storage_type(0) << (__result.__ctz_ - __ddn)) & (~__storage_type(0) >> __clz_r);
-                *__result.__seg_ &= ~__m;
-                if (__result.__ctz_ > __last.__ctz_)
-                    *__result.__seg_ |= __b << (__result.__ctz_ - __last.__ctz_);
-                else
-                    *__result.__seg_ |= __b >> (__last.__ctz_ - __result.__ctz_);
-                __result.__ctz_ = static_cast<unsigned>(((-__ddn & (__bits_per_word - 1)) +
-                                                         __result.__ctz_)  % __bits_per_word);
-                __dn -= __ddn;
-            }
-            if (__dn > 0)
-            {
-                // __result.__ctz_ == 0
-                --__result.__seg_;
-                __result.__ctz_ = static_cast<unsigned>(-__dn & (__bits_per_word - 1));
-                __m = ~__storage_type(0) << __result.__ctz_;
-                *__result.__seg_ &= ~__m;
-                __last.__ctz_ -= __dn + __ddn;
-                *__result.__seg_ |= __b << (__result.__ctz_ - __last.__ctz_);
-            }
-            // __last.__ctz_ = 0
-         }
-        // __last.__ctz_ == 0 || __n == 0
-        // __result.__ctz_ != 0 || __n == 0
-        // do middle words
-        unsigned __clz_r = __bits_per_word - __result.__ctz_;
-        __storage_type __m = ~__storage_type(0) >> __clz_r;
-        for (; __n >= __bits_per_word; __n -= __bits_per_word)
-        {
-            __storage_type __b = *--__last.__seg_;
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b >> __clz_r;
-            *--__result.__seg_ &= __m;
-            *__result.__seg_ |= __b << __result.__ctz_;
-        }
-        // do last word
-        if (__n > 0)
-        {
-            __m = ~__storage_type(0) << (__bits_per_word - __n);
-            __storage_type __b = *--__last.__seg_ & __m;
-            __clz_r = __bits_per_word - __result.__ctz_;
-            __storage_type __dn = _VSTD::min(__n, static_cast<difference_type>(__result.__ctz_));
-            __m = (~__storage_type(0) << (__result.__ctz_ - __dn)) & (~__storage_type(0) >> __clz_r);
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b >> (__bits_per_word - __result.__ctz_);
-            __result.__ctz_ = static_cast<unsigned>(((-__dn & (__bits_per_word - 1)) +
-                                                     __result.__ctz_)  % __bits_per_word);
-            __n -= __dn;
-            if (__n > 0)
-            {
-                // __result.__ctz_ == 0
-                --__result.__seg_;
-                __result.__ctz_ = static_cast<unsigned>(-__n & (__bits_per_word - 1));
-                __m = ~__storage_type(0) << __result.__ctz_;
-                *__result.__seg_ &= ~__m;
-                *__result.__seg_ |= __b << (__result.__ctz_ - (__bits_per_word - __n - __dn));
-            }
-        }
-    }
-    return __result;
-}
-
-template <class _Cp, bool _IsConst>
-inline _LIBCPP_INLINE_VISIBILITY
-__bit_iterator<_Cp, false>
-copy_backward(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
-{
-    if (__last.__ctz_ == __result.__ctz_)
-        return __copy_backward_aligned(__first, __last, __result);
-    return __copy_backward_unaligned(__first, __last, __result);
-}
-
-// move
-
-template <class _Cp, bool _IsConst>
-inline _LIBCPP_INLINE_VISIBILITY
-__bit_iterator<_Cp, false>
-move(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
-{
-    return _VSTD::copy(__first, __last, __result);
-}
-
-// move_backward
-
-template <class _Cp, bool _IsConst>
-inline _LIBCPP_INLINE_VISIBILITY
-__bit_iterator<_Cp, false>
-move_backward(__bit_iterator<_Cp, _IsConst> __first, __bit_iterator<_Cp, _IsConst> __last, __bit_iterator<_Cp, false> __result)
-{
-    return _VSTD::copy_backward(__first, __last, __result);
-}
-
-// swap_ranges
-
-template <class __C1, class __C2>
-__bit_iterator<__C2, false>
-__swap_ranges_aligned(__bit_iterator<__C1, false> __first, __bit_iterator<__C1, false> __last,
-                      __bit_iterator<__C2, false> __result)
-{
-    typedef __bit_iterator<__C1, false> _I1;
-    typedef  typename _I1::difference_type difference_type;
-    typedef typename _I1::__storage_type __storage_type;
-    const int __bits_per_word = _I1::__bits_per_word;
-    difference_type __n = __last - __first;
-    if (__n > 0)
-    {
-        // do first word
-        if (__first.__ctz_ != 0)
-        {
-            unsigned __clz = __bits_per_word - __first.__ctz_;
-            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz), __n);
-            __n -= __dn;
-            __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz - __dn));
-            __storage_type __b1 = *__first.__seg_ & __m;
-            *__first.__seg_ &= ~__m;
-            __storage_type __b2 = *__result.__seg_ & __m;
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b1;
-            *__first.__seg_  |= __b2;
-            __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word;
-            __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word);
-            ++__first.__seg_;
-            // __first.__ctz_ = 0;
-        }
-        // __first.__ctz_ == 0;
-        // do middle words
-        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first.__seg_, ++__result.__seg_)
-            swap(*__first.__seg_, *__result.__seg_);
-        // do last word
-        if (__n > 0)
-        {
-            __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-            __storage_type __b1 = *__first.__seg_ & __m;
-            *__first.__seg_ &= ~__m;
-            __storage_type __b2 = *__result.__seg_ & __m;
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b1;
-            *__first.__seg_  |= __b2;
-            __result.__ctz_ = static_cast<unsigned>(__n);
-        }
-    }
-    return __result;
-}
-
-template <class __C1, class __C2>
-__bit_iterator<__C2, false>
-__swap_ranges_unaligned(__bit_iterator<__C1, false> __first, __bit_iterator<__C1, false> __last,
-                        __bit_iterator<__C2, false> __result)
-{
-    typedef __bit_iterator<__C1, false> _I1;
-    typedef  typename _I1::difference_type difference_type;
-    typedef typename _I1::__storage_type __storage_type;
-    const int __bits_per_word = _I1::__bits_per_word;
-    difference_type __n = __last - __first;
-    if (__n > 0)
-    {
-        // do first word
-        if (__first.__ctz_ != 0)
-        {
-            unsigned __clz_f = __bits_per_word - __first.__ctz_;
-            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz_f), __n);
-            __n -= __dn;
-            __storage_type __m = (~__storage_type(0) << __first.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-            __storage_type __b1 = *__first.__seg_ & __m;
-            *__first.__seg_ &= ~__m;
-            unsigned __clz_r = __bits_per_word - __result.__ctz_;
-            __storage_type __ddn = _VSTD::min<__storage_type>(__dn, __clz_r);
-            __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __ddn));
-            __storage_type __b2 = *__result.__seg_ & __m;
-            *__result.__seg_ &= ~__m;
-            if (__result.__ctz_ > __first.__ctz_)
-            {
-                unsigned __s = __result.__ctz_ - __first.__ctz_;
-                *__result.__seg_ |= __b1 << __s;
-                *__first.__seg_  |= __b2 >> __s;
-            }
-            else
-            {
-                unsigned __s = __first.__ctz_ - __result.__ctz_;
-                *__result.__seg_ |= __b1 >> __s;
-                *__first.__seg_  |= __b2 << __s;
-            }
-            __result.__seg_ += (__ddn + __result.__ctz_) / __bits_per_word;
-            __result.__ctz_ = static_cast<unsigned>((__ddn + __result.__ctz_)  % __bits_per_word);
-            __dn -= __ddn;
-            if (__dn > 0)
-            {
-                __m = ~__storage_type(0) >> (__bits_per_word - __dn);
-                __b2 = *__result.__seg_ & __m;
-                *__result.__seg_ &= ~__m;
-                unsigned __s = __first.__ctz_ + __ddn;
-                *__result.__seg_ |= __b1 >> __s;
-                *__first.__seg_  |= __b2 << __s;
-                __result.__ctz_ = static_cast<unsigned>(__dn);
-            }
-            ++__first.__seg_;
-            // __first.__ctz_ = 0;
-        }
-        // __first.__ctz_ == 0;
-        // do middle words
-        __storage_type __m = ~__storage_type(0) << __result.__ctz_;
-        unsigned __clz_r = __bits_per_word - __result.__ctz_;
-        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first.__seg_)
-        {
-            __storage_type __b1 = *__first.__seg_;
-            __storage_type __b2 = *__result.__seg_ & __m;
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b1 << __result.__ctz_;
-            *__first.__seg_  = __b2 >> __result.__ctz_;
-            ++__result.__seg_;
-            __b2 = *__result.__seg_ & ~__m;
-            *__result.__seg_ &= __m;
-            *__result.__seg_ |= __b1 >> __clz_r;
-            *__first.__seg_  |= __b2 << __clz_r;
-        }
-        // do last word
-        if (__n > 0)
-        {
-            __m = ~__storage_type(0) >> (__bits_per_word - __n);
-            __storage_type __b1 = *__first.__seg_ & __m;
-            *__first.__seg_ &= ~__m;
-            __storage_type __dn = _VSTD::min<__storage_type>(__n, __clz_r);
-            __m = (~__storage_type(0) << __result.__ctz_) & (~__storage_type(0) >> (__clz_r - __dn));
-            __storage_type __b2 = *__result.__seg_ & __m;
-            *__result.__seg_ &= ~__m;
-            *__result.__seg_ |= __b1 << __result.__ctz_;
-            *__first.__seg_  |= __b2 >> __result.__ctz_;
-            __result.__seg_ += (__dn + __result.__ctz_) / __bits_per_word;
-            __result.__ctz_ = static_cast<unsigned>((__dn + __result.__ctz_)  % __bits_per_word);
-            __n -= __dn;
-            if (__n > 0)
-            {
-                __m = ~__storage_type(0) >> (__bits_per_word - __n);
-                __b2 = *__result.__seg_ & __m;
-                *__result.__seg_ &= ~__m;
-                *__result.__seg_ |= __b1 >> __dn;
-                *__first.__seg_  |= __b2 << __dn;
-                __result.__ctz_ = static_cast<unsigned>(__n);
-            }
-        }
-    }
-    return __result;
-}
-
-template <class __C1, class __C2>
-inline _LIBCPP_INLINE_VISIBILITY
-__bit_iterator<__C2, false>
-swap_ranges(__bit_iterator<__C1, false> __first1, __bit_iterator<__C1, false> __last1,
-            __bit_iterator<__C2, false> __first2)
-{
-    if (__first1.__ctz_ == __first2.__ctz_)
-        return __swap_ranges_aligned(__first1, __last1, __first2);
-    return __swap_ranges_unaligned(__first1, __last1, __first2);
-}
-
-// rotate
-
-template <class _Cp>
-struct __bit_array
-{
-    typedef typename _Cp::difference_type difference_type;
-    typedef typename _Cp::__storage_type  __storage_type;
-    typedef typename _Cp::__storage_pointer __storage_pointer;
-    typedef typename _Cp::iterator        iterator;
-    static const unsigned __bits_per_word = _Cp::__bits_per_word;
-    static const unsigned _Np = 4;
-
-    difference_type __size_;
-    __storage_type __word_[_Np];
-
-    _LIBCPP_INLINE_VISIBILITY static difference_type capacity()
-        {return static_cast<difference_type>(_Np * __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY explicit __bit_array(difference_type __s) : __size_(__s) {}
-    _LIBCPP_INLINE_VISIBILITY iterator begin()
-    {
-        return iterator(pointer_traits<__storage_pointer>::pointer_to(__word_[0]), 0);
-    }
-    _LIBCPP_INLINE_VISIBILITY iterator end()
-    {
-        return iterator(pointer_traits<__storage_pointer>::pointer_to(__word_[0]) + __size_ / __bits_per_word,
-                                                  static_cast<unsigned>(__size_ % __bits_per_word));
-    }
-};
-
-template <class _Cp>
-__bit_iterator<_Cp, false>
-rotate(__bit_iterator<_Cp, false> __first, __bit_iterator<_Cp, false> __middle, __bit_iterator<_Cp, false> __last)
-{
-    typedef __bit_iterator<_Cp, false> _I1;
-    typedef  typename _I1::difference_type difference_type;
-    difference_type __d1 = __middle - __first;
-    difference_type __d2 = __last - __middle;
-    _I1 __r = __first + __d2;
-    while (__d1 != 0 && __d2 != 0)
-    {
-        if (__d1 <= __d2)
-        {
-            if (__d1 <= __bit_array<_Cp>::capacity())
-            {
-                __bit_array<_Cp> __b(__d1);
-                _VSTD::copy(__first, __middle, __b.begin());
-                _VSTD::copy(__b.begin(), __b.end(), _VSTD::copy(__middle, __last, __first));
-                break;
-            }
-            else
-            {
-                __bit_iterator<_Cp, false> __mp = _VSTD::swap_ranges(__first, __middle, __middle);
-                __first = __middle;
-                __middle = __mp;
-                __d2 -= __d1;
-            }
-        }
-        else
-        {
-            if (__d2 <= __bit_array<_Cp>::capacity())
-            {
-                __bit_array<_Cp> __b(__d2);
-                _VSTD::copy(__middle, __last, __b.begin());
-                _VSTD::copy_backward(__b.begin(), __b.end(), _VSTD::copy_backward(__first, __middle, __last));
-                break;
-            }
-            else
-            {
-                __bit_iterator<_Cp, false> __mp = __first + __d2;
-                _VSTD::swap_ranges(__first, __mp, __middle);
-                __first = __mp;
-                __d1 -= __d2;
-            }
-        }
-    }
-    return __r;
-}
-
-// equal
-
-template <class _Cp, bool _IC1, bool _IC2>
-bool
-__equal_unaligned(__bit_iterator<_Cp, _IC1> __first1, __bit_iterator<_Cp, _IC1> __last1,
-                  __bit_iterator<_Cp, _IC2> __first2)
-{
-    typedef __bit_iterator<_Cp, _IC1> _It;
-    typedef  typename _It::difference_type difference_type;
-    typedef typename _It::__storage_type __storage_type;
-    static const int __bits_per_word = _It::__bits_per_word;
-    difference_type __n = __last1 - __first1;
-    if (__n > 0)
-    {
-        // do first word
-        if (__first1.__ctz_ != 0)
-        {
-            unsigned __clz_f = __bits_per_word - __first1.__ctz_;
-            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz_f), __n);
-            __n -= __dn;
-            __storage_type __m = (~__storage_type(0) << __first1.__ctz_) & (~__storage_type(0) >> (__clz_f - __dn));
-            __storage_type __b = *__first1.__seg_ & __m;
-            unsigned __clz_r = __bits_per_word - __first2.__ctz_;
-            __storage_type __ddn = _VSTD::min<__storage_type>(__dn, __clz_r);
-            __m = (~__storage_type(0) << __first2.__ctz_) & (~__storage_type(0) >> (__clz_r - __ddn));
-            if (__first2.__ctz_ > __first1.__ctz_)
-            {
-                if ((*__first2.__seg_ & __m) != (__b << (__first2.__ctz_ - __first1.__ctz_)))
-                    return false;
-            }
-            else
-            {
-                if ((*__first2.__seg_ & __m) != (__b >> (__first1.__ctz_ - __first2.__ctz_)))
-                    return false;
-            }
-            __first2.__seg_ += (__ddn + __first2.__ctz_) / __bits_per_word;
-            __first2.__ctz_ = static_cast<unsigned>((__ddn + __first2.__ctz_)  % __bits_per_word);
-            __dn -= __ddn;
-            if (__dn > 0)
-            {
-                __m = ~__storage_type(0) >> (__bits_per_word - __dn);
-                if ((*__first2.__seg_ & __m) != (__b >> (__first1.__ctz_ + __ddn)))
-                    return false;
-                __first2.__ctz_ = static_cast<unsigned>(__dn);
-            }
-            ++__first1.__seg_;
-            // __first1.__ctz_ = 0;
-        }
-        // __first1.__ctz_ == 0;
-        // do middle words
-        unsigned __clz_r = __bits_per_word - __first2.__ctz_;
-        __storage_type __m = ~__storage_type(0) << __first2.__ctz_;
-        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first1.__seg_)
-        {
-            __storage_type __b = *__first1.__seg_;
-            if ((*__first2.__seg_ & __m) != (__b << __first2.__ctz_))
-                return false;
-            ++__first2.__seg_;
-            if ((*__first2.__seg_ & ~__m) != (__b >> __clz_r))
-                return false;
-        }
-        // do last word
-        if (__n > 0)
-        {
-            __m = ~__storage_type(0) >> (__bits_per_word - __n);
-            __storage_type __b = *__first1.__seg_ & __m;
-            __storage_type __dn = _VSTD::min(__n, static_cast<difference_type>(__clz_r));
-            __m = (~__storage_type(0) << __first2.__ctz_) & (~__storage_type(0) >> (__clz_r - __dn));
-            if ((*__first2.__seg_ & __m) != (__b << __first2.__ctz_))
-                return false;
-            __first2.__seg_ += (__dn + __first2.__ctz_) / __bits_per_word;
-            __first2.__ctz_ = static_cast<unsigned>((__dn + __first2.__ctz_)  % __bits_per_word);
-            __n -= __dn;
-            if (__n > 0)
-            {
-                __m = ~__storage_type(0) >> (__bits_per_word - __n);
-                if ((*__first2.__seg_ & __m) != (__b >> __dn))
-                    return false;
-            }
-        }
-    }
-    return true;
-}
-
-template <class _Cp, bool _IC1, bool _IC2>
-bool
-__equal_aligned(__bit_iterator<_Cp, _IC1> __first1, __bit_iterator<_Cp, _IC1> __last1,
-                __bit_iterator<_Cp, _IC2> __first2)
-{
-    typedef __bit_iterator<_Cp, _IC1> _It;
-    typedef  typename _It::difference_type difference_type;
-    typedef typename _It::__storage_type __storage_type;
-    static const int __bits_per_word = _It::__bits_per_word;
-    difference_type __n = __last1 - __first1;
-    if (__n > 0)
-    {
-        // do first word
-        if (__first1.__ctz_ != 0)
-        {
-            unsigned __clz = __bits_per_word - __first1.__ctz_;
-            difference_type __dn = _VSTD::min(static_cast<difference_type>(__clz), __n);
-            __n -= __dn;
-            __storage_type __m = (~__storage_type(0) << __first1.__ctz_) & (~__storage_type(0) >> (__clz - __dn));
-            if ((*__first2.__seg_ & __m) != (*__first1.__seg_ & __m))
-                return false;
-            ++__first2.__seg_;
-            ++__first1.__seg_;
-            // __first1.__ctz_ = 0;
-            // __first2.__ctz_ = 0;
-        }
-        // __first1.__ctz_ == 0;
-        // __first2.__ctz_ == 0;
-        // do middle words
-        for (; __n >= __bits_per_word; __n -= __bits_per_word, ++__first1.__seg_, ++__first2.__seg_)
-            if (*__first2.__seg_ != *__first1.__seg_)
-                return false;
-        // do last word
-        if (__n > 0)
-        {
-            __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-            if ((*__first2.__seg_ & __m) != (*__first1.__seg_ & __m))
-                return false;
-        }
-    }
-    return true;
-}
-
-template <class _Cp, bool _IC1, bool _IC2>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-equal(__bit_iterator<_Cp, _IC1> __first1, __bit_iterator<_Cp, _IC1> __last1, __bit_iterator<_Cp, _IC2> __first2)
-{
-    if (__first1.__ctz_ == __first2.__ctz_)
-        return __equal_aligned(__first1, __last1, __first2);
-    return __equal_unaligned(__first1, __last1, __first2);
-}
-
-template <class _Cp, bool _IsConst,
-          typename _Cp::__storage_type>
-class __bit_iterator
-{
-public:
-    typedef typename _Cp::difference_type                                                          difference_type;
-    typedef bool                                                                                  value_type;
-    typedef __bit_iterator                                                                        pointer;
-    typedef typename conditional<_IsConst, __bit_const_reference<_Cp>, __bit_reference<_Cp> >::type reference;
-    typedef random_access_iterator_tag                                                            iterator_category;
-
-private:
-    typedef typename _Cp::__storage_type                                           __storage_type;
-    typedef typename conditional<_IsConst, typename _Cp::__const_storage_pointer,
-                                           typename _Cp::__storage_pointer>::type  __storage_pointer;
-    static const unsigned __bits_per_word = _Cp::__bits_per_word;
-
-    __storage_pointer __seg_;
-    unsigned          __ctz_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator() _NOEXCEPT
-#if _LIBCPP_STD_VER > 11
-    : __seg_(nullptr), __ctz_(0)
-#endif
-    {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __bit_iterator(const __bit_iterator<_Cp, false>& __it) _NOEXCEPT
-        : __seg_(__it.__seg_), __ctz_(__it.__ctz_) {}
-
-    _LIBCPP_INLINE_VISIBILITY reference operator*() const _NOEXCEPT
-        {return reference(__seg_, __storage_type(1) << __ctz_);}
-
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator++()
-    {
-        if (__ctz_ != __bits_per_word-1)
-            ++__ctz_;
-        else
-        {
-            __ctz_ = 0;
-            ++__seg_;
-        }
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator operator++(int)
-    {
-        __bit_iterator __tmp = *this;
-        ++(*this);
-        return __tmp;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator--()
-    {
-        if (__ctz_ != 0)
-            --__ctz_;
-        else
-        {
-            __ctz_ = __bits_per_word - 1;
-            --__seg_;
-        }
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator operator--(int)
-    {
-        __bit_iterator __tmp = *this;
-        --(*this);
-        return __tmp;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator+=(difference_type __n)
-    {
-        if (__n >= 0)
-            __seg_ += (__n + __ctz_) / __bits_per_word;
-        else
-            __seg_ += static_cast<difference_type>(__n - __bits_per_word + __ctz_ + 1)
-                    / static_cast<difference_type>(__bits_per_word);
-        __n &= (__bits_per_word - 1);
-        __ctz_ = static_cast<unsigned>((__n + __ctz_)  % __bits_per_word);
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator& operator-=(difference_type __n)
-    {
-        return *this += -__n;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator operator+(difference_type __n) const
-    {
-        __bit_iterator __t(*this);
-        __t += __n;
-        return __t;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __bit_iterator operator-(difference_type __n) const
-    {
-        __bit_iterator __t(*this);
-        __t -= __n;
-        return __t;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    friend __bit_iterator operator+(difference_type __n, const __bit_iterator& __it) {return __it + __n;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    friend difference_type operator-(const __bit_iterator& __x, const __bit_iterator& __y)
-        {return (__x.__seg_ - __y.__seg_) * __bits_per_word + __x.__ctz_ - __y.__ctz_;}
-
-    _LIBCPP_INLINE_VISIBILITY reference operator[](difference_type __n) const {return *(*this + __n);}
-
-    _LIBCPP_INLINE_VISIBILITY friend bool operator==(const __bit_iterator& __x, const __bit_iterator& __y)
-        {return __x.__seg_ == __y.__seg_ && __x.__ctz_ == __y.__ctz_;}
-
-    _LIBCPP_INLINE_VISIBILITY friend bool operator!=(const __bit_iterator& __x, const __bit_iterator& __y)
-        {return !(__x == __y);}
-
-    _LIBCPP_INLINE_VISIBILITY friend bool operator<(const __bit_iterator& __x, const __bit_iterator& __y)
-        {return __x.__seg_ < __y.__seg_ || (__x.__seg_ == __y.__seg_ && __x.__ctz_ < __y.__ctz_);}
-
-    _LIBCPP_INLINE_VISIBILITY friend bool operator>(const __bit_iterator& __x, const __bit_iterator& __y)
-        {return __y < __x;}
-
-    _LIBCPP_INLINE_VISIBILITY friend bool operator<=(const __bit_iterator& __x, const __bit_iterator& __y)
-        {return !(__y < __x);}
-
-    _LIBCPP_INLINE_VISIBILITY friend bool operator>=(const __bit_iterator& __x, const __bit_iterator& __y)
-        {return !(__x < __y);}
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    __bit_iterator(__storage_pointer __s, unsigned __ctz) _NOEXCEPT
-        : __seg_(__s), __ctz_(__ctz) {}
-
-    friend typename _Cp::__self;
-
-    friend class __bit_reference<_Cp>;
-    friend class __bit_const_reference<_Cp>;
-    friend class __bit_iterator<_Cp, true>;
-    template <class _Dp> friend struct __bit_array;
-    template <class _Dp> friend void __fill_n_false(__bit_iterator<_Dp, false> __first, typename _Dp::size_type __n);
-    template <class _Dp> friend void __fill_n_true(__bit_iterator<_Dp, false> __first, typename _Dp::size_type __n);
-    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> __copy_aligned(__bit_iterator<_Dp, _IC> __first,
-                                                                                  __bit_iterator<_Dp, _IC> __last,
-                                                                                  __bit_iterator<_Dp, false> __result);
-    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> __copy_unaligned(__bit_iterator<_Dp, _IC> __first,
-                                                                                    __bit_iterator<_Dp, _IC> __last,
-                                                                                    __bit_iterator<_Dp, false> __result);
-    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> copy(__bit_iterator<_Dp, _IC> __first,
-                                                                        __bit_iterator<_Dp, _IC> __last,
-                                                                        __bit_iterator<_Dp, false> __result);
-    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> __copy_backward_aligned(__bit_iterator<_Dp, _IC> __first,
-                                                                                           __bit_iterator<_Dp, _IC> __last,
-                                                                                           __bit_iterator<_Dp, false> __result);
-    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> __copy_backward_unaligned(__bit_iterator<_Dp, _IC> __first,
-                                                                                             __bit_iterator<_Dp, _IC> __last,
-                                                                                             __bit_iterator<_Dp, false> __result);
-    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, false> copy_backward(__bit_iterator<_Dp, _IC> __first,
-                                                                                 __bit_iterator<_Dp, _IC> __last,
-                                                                                 __bit_iterator<_Dp, false> __result);
-    template <class __C1, class __C2>friend __bit_iterator<__C2, false> __swap_ranges_aligned(__bit_iterator<__C1, false>,
-                                                                                           __bit_iterator<__C1, false>,
-                                                                                           __bit_iterator<__C2, false>);
-    template <class __C1, class __C2>friend __bit_iterator<__C2, false> __swap_ranges_unaligned(__bit_iterator<__C1, false>,
-                                                                                             __bit_iterator<__C1, false>,
-                                                                                             __bit_iterator<__C2, false>);
-    template <class __C1, class __C2>friend __bit_iterator<__C2, false> swap_ranges(__bit_iterator<__C1, false>,
-                                                                                 __bit_iterator<__C1, false>,
-                                                                                 __bit_iterator<__C2, false>);
-    template <class _Dp> friend __bit_iterator<_Dp, false> rotate(__bit_iterator<_Dp, false>,
-                                                                __bit_iterator<_Dp, false>,
-                                                                __bit_iterator<_Dp, false>);
-    template <class _Dp, bool _IC1, bool _IC2> friend bool __equal_aligned(__bit_iterator<_Dp, _IC1>,
-                                                    __bit_iterator<_Dp, _IC1>,
-                                                    __bit_iterator<_Dp, _IC2>);
-    template <class _Dp, bool _IC1, bool _IC2> friend bool __equal_unaligned(__bit_iterator<_Dp, _IC1>,
-                                                      __bit_iterator<_Dp, _IC1>,
-                                                      __bit_iterator<_Dp, _IC2>);
-    template <class _Dp, bool _IC1, bool _IC2> friend bool equal(__bit_iterator<_Dp, _IC1>,
-                                                                __bit_iterator<_Dp, _IC1>,
-                                                                __bit_iterator<_Dp, _IC2>);
-    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, _IC> __find_bool_true(__bit_iterator<_Dp, _IC>,
-                                                                          typename _Dp::size_type);
-    template <class _Dp, bool _IC> friend __bit_iterator<_Dp, _IC> __find_bool_false(__bit_iterator<_Dp, _IC>,
-                                                                           typename _Dp::size_type);
-    template <class _Dp, bool _IC> friend typename __bit_iterator<_Dp, _IC>::difference_type
-                   __count_bool_true(__bit_iterator<_Dp, _IC>, typename _Dp::size_type);
-    template <class _Dp, bool _IC> friend typename __bit_iterator<_Dp, _IC>::difference_type
-                   __count_bool_false(__bit_iterator<_Dp, _IC>, typename _Dp::size_type);
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP___BIT_REFERENCE
diff --git a/lib/libcxx/include/__bsd_locale_defaults.h b/lib/libcxx/include/__bsd_locale_defaults.h
deleted file mode 100644
index cbc407d1030..00000000000
--- a/lib/libcxx/include/__bsd_locale_defaults.h
+++ /dev/null
@@ -1,37 +0,0 @@
-// -*- C++ -*-
-//===---------------------- __bsd_locale_defaults.h -----------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-// The BSDs have lots of *_l functions.  We don't want to define those symbols
-// on other platforms though, for fear of conflicts with user code.  So here,
-// we will define the mapping from an internal macro to the real BSD symbol.
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_BSD_LOCALE_DEFAULTS_H
-#define _LIBCPP_BSD_LOCALE_DEFAULTS_H
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#define __libcpp_mb_cur_max_l(loc)                          MB_CUR_MAX_L(loc)
-#define __libcpp_btowc_l(ch, loc)                           btowc_l(ch, loc)
-#define __libcpp_wctob_l(wch, loc)                          wctob_l(wch, loc)
-#define __libcpp_wcsnrtombs_l(dst, src, nwc, len, ps, loc)  wcsnrtombs_l(dst, src, nwc, len, ps, loc)
-#define __libcpp_wcrtomb_l(src, wc, ps, loc)                wcrtomb_l(src, wc, ps, loc)
-#define __libcpp_mbsnrtowcs_l(dst, src, nms, len, ps, loc)  mbsnrtowcs_l(dst, src, nms, len, ps, loc)
-#define __libcpp_mbrtowc_l(pwc, s, n, ps, l)                mbrtowc_l(pwc, s, n, ps, l)
-#define __libcpp_mbtowc_l(pwc, pmb, max, l)                 mbtowc_l(pwc, pmb, max, l)
-#define __libcpp_mbrlen_l(s, n, ps, l)                      mbrlen_l(s, n, ps, l)
-#define __libcpp_localeconv_l(l)                            localeconv_l(l)
-#define __libcpp_mbsrtowcs_l(dest, src, len, ps, l)         mbsrtowcs_l(dest, src, len, ps, l)
-#define __libcpp_snprintf_l(...)                            snprintf_l(__VA_ARGS__)
-#define __libcpp_asprintf_l(...)                            asprintf_l(__VA_ARGS__)
-#define __libcpp_sscanf_l(...)                              sscanf_l(__VA_ARGS__)
-
-#endif // _LIBCPP_BSD_LOCALE_DEFAULTS_H
diff --git a/lib/libcxx/include/__bsd_locale_fallbacks.h b/lib/libcxx/include/__bsd_locale_fallbacks.h
deleted file mode 100644
index 3097b01410d..00000000000
--- a/lib/libcxx/include/__bsd_locale_fallbacks.h
+++ /dev/null
@@ -1,140 +0,0 @@
-// -*- C++ -*-
-//===---------------------- __bsd_locale_fallbacks.h ----------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-// The BSDs have lots of *_l functions.  This file provides reimplementations
-// of those functions for non-BSD platforms.
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_BSD_LOCALE_FALLBACKS_DEFAULTS_H
-#define _LIBCPP_BSD_LOCALE_FALLBACKS_DEFAULTS_H
-
-#include <stdlib.h>
-#include <stdarg.h>
-#include <memory>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-inline _LIBCPP_INLINE_VISIBILITY
-decltype(MB_CUR_MAX) __libcpp_mb_cur_max_l(locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return MB_CUR_MAX;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-wint_t __libcpp_btowc_l(int __c, locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return btowc(__c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __libcpp_wctob_l(wint_t __c, locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return wctob(__c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-size_t __libcpp_wcsnrtombs_l(char *__dest, const wchar_t **__src, size_t __nwc,
-                         size_t __len, mbstate_t *__ps, locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return wcsnrtombs(__dest, __src, __nwc, __len, __ps);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-size_t __libcpp_wcrtomb_l(char *__s, wchar_t __wc, mbstate_t *__ps, locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return wcrtomb(__s, __wc, __ps);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-size_t __libcpp_mbsnrtowcs_l(wchar_t * __dest, const char **__src, size_t __nms,
-                      size_t __len, mbstate_t *__ps, locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return mbsnrtowcs(__dest, __src, __nms, __len, __ps);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-size_t __libcpp_mbrtowc_l(wchar_t *__pwc, const char *__s, size_t __n,
-                   mbstate_t *__ps, locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return mbrtowc(__pwc, __s, __n, __ps);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __libcpp_mbtowc_l(wchar_t *__pwc, const char *__pmb, size_t __max, locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return mbtowc(__pwc, __pmb, __max);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-size_t __libcpp_mbrlen_l(const char *__s, size_t __n, mbstate_t *__ps, locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return mbrlen(__s, __n, __ps);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-lconv *__libcpp_localeconv_l(locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return localeconv();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-size_t __libcpp_mbsrtowcs_l(wchar_t *__dest, const char **__src, size_t __len,
-                     mbstate_t *__ps, locale_t __l)
-{
-    __libcpp_locale_guard __current(__l);
-    return mbsrtowcs(__dest, __src, __len, __ps);
-}
-
-inline
-int __libcpp_snprintf_l(char *__s, size_t __n, locale_t __l, const char *__format, ...) {
-    va_list __va;
-    va_start(__va, __format);
-    __libcpp_locale_guard __current(__l);
-    int __res = vsnprintf(__s, __n, __format, __va);
-    va_end(__va);
-    return __res;
-}
-
-inline
-int __libcpp_asprintf_l(char **__s, locale_t __l, const char *__format, ...) {
-    va_list __va;
-    va_start(__va, __format);
-    __libcpp_locale_guard __current(__l);
-    int __res = vasprintf(__s, __format, __va);
-    va_end(__va);
-    return __res;
-}
-
-inline
-int __libcpp_sscanf_l(const char *__s, locale_t __l, const char *__format, ...) {
-    va_list __va;
-    va_start(__va, __format);
-    __libcpp_locale_guard __current(__l);
-    int __res = vsscanf(__s, __format, __va);
-    va_end(__va);
-    return __res;
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP_BSD_LOCALE_FALLBACKS_DEFAULTS_H
diff --git a/lib/libcxx/include/__config b/lib/libcxx/include/__config
deleted file mode 100644
index 7ec1d3de5d8..00000000000
--- a/lib/libcxx/include/__config
+++ /dev/null
@@ -1,1457 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- __config ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CONFIG
-#define _LIBCPP_CONFIG
-
-#if defined(_MSC_VER) && !defined(__clang__)
-#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#    define _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
-#  endif
-#endif
-
-#ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
-#pragma GCC system_header
-#endif
-
-#ifdef __cplusplus
-
-#ifdef __GNUC__
-#  define _GNUC_VER (__GNUC__ * 100 + __GNUC_MINOR__)
-// The _GNUC_VER_NEW macro better represents the new GCC versioning scheme
-// introduced in GCC 5.0.
-#  define _GNUC_VER_NEW (_GNUC_VER * 10 + __GNUC_PATCHLEVEL__)
-#else
-#  define _GNUC_VER 0
-#  define _GNUC_VER_NEW 0
-#endif
-
-#define _LIBCPP_VERSION 8000
-
-#ifndef _LIBCPP_ABI_VERSION
-#  define _LIBCPP_ABI_VERSION 1
-#endif
-
-#ifndef _LIBCPP_STD_VER
-#  if  __cplusplus <= 201103L
-#    define _LIBCPP_STD_VER 11
-#  elif __cplusplus <= 201402L
-#    define _LIBCPP_STD_VER 14
-#  elif __cplusplus <= 201703L
-#    define _LIBCPP_STD_VER 17
-#  else
-#    define _LIBCPP_STD_VER 18  // current year, or date of c++2a ratification
-#  endif
-#endif  // _LIBCPP_STD_VER
-
-#if defined(__ELF__)
-#  define _LIBCPP_OBJECT_FORMAT_ELF   1
-#elif defined(__MACH__)
-#  define _LIBCPP_OBJECT_FORMAT_MACHO 1
-#elif defined(_WIN32)
-#  define _LIBCPP_OBJECT_FORMAT_COFF  1
-#elif defined(__wasm__)
-#  define _LIBCPP_OBJECT_FORMAT_WASM  1
-#else
-#  error Unknown object file format
-#endif
-
-#if defined(_LIBCPP_ABI_UNSTABLE) || _LIBCPP_ABI_VERSION >= 2
-// Change short string representation so that string data starts at offset 0,
-// improving its alignment in some cases.
-#  define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-// Fix deque iterator type in order to support incomplete types.
-#  define _LIBCPP_ABI_INCOMPLETE_TYPES_IN_DEQUE
-// Fix undefined behavior in how std::list stores its linked nodes.
-#  define _LIBCPP_ABI_LIST_REMOVE_NODE_POINTER_UB
-// Fix undefined behavior in  how __tree stores its end and parent nodes.
-#  define _LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB
-// Fix undefined behavior in how __hash_table stores its pointer types.
-#  define _LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB
-#  define _LIBCPP_ABI_FORWARD_LIST_REMOVE_NODE_POINTER_UB
-#  define _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE
-// Don't use a nullptr_t simulation type in C++03 instead using C++11 nullptr
-// provided under the alternate keyword __nullptr, which changes the mangling
-// of nullptr_t. This option is ABI incompatible with GCC in C++03 mode.
-#  define _LIBCPP_ABI_ALWAYS_USE_CXX11_NULLPTR
-// Define the `pointer_safety` enum as a C++11 strongly typed enumeration
-// instead of as a class simulating an enum. If this option is enabled
-// `pointer_safety` and `get_pointer_safety()` will no longer be available
-// in C++03.
-#  define _LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE
-// Define a key function for `bad_function_call` in the library, to centralize
-// its vtable and typeinfo to libc++ rather than having all other libraries
-// using that class define their own copies.
-#  define _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
-// Enable optimized version of __do_get_(un)signed which avoids redundant copies.
-#  define _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
-// Use the smallest possible integer type to represent the index of the variant.
-// Previously libc++ used "unsigned int" exclusivly.
-#  define _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION
-// Unstable attempt to provide a more optimized std::function
-#  define _LIBCPP_ABI_OPTIMIZED_FUNCTION
-#elif _LIBCPP_ABI_VERSION == 1
-#  if !defined(_LIBCPP_OBJECT_FORMAT_COFF)
-// Enable compiling copies of now inline methods into the dylib to support
-// applications compiled against older libraries. This is unnecessary with
-// COFF dllexport semantics, since dllexport forces a non-inline definition
-// of inline functions to be emitted anyway. Our own non-inline copy would
-// conflict with the dllexport-emitted copy, so we disable it.
-#    define _LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS
-#  endif
-// Feature macros for disabling pre ABI v1 features. All of these options
-// are deprecated.
-#  if defined(__FreeBSD__)
-#    define _LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR
-#  endif
-#endif
-
-#ifdef _LIBCPP_TRIVIAL_PAIR_COPY_CTOR
-#error "_LIBCPP_TRIVIAL_PAIR_COPY_CTOR" is no longer supported. \
-       use _LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR instead
-#endif
-
-#define _LIBCPP_CONCAT1(_LIBCPP_X,_LIBCPP_Y) _LIBCPP_X##_LIBCPP_Y
-#define _LIBCPP_CONCAT(_LIBCPP_X,_LIBCPP_Y) _LIBCPP_CONCAT1(_LIBCPP_X,_LIBCPP_Y)
-
-#ifndef _LIBCPP_ABI_NAMESPACE
-# define _LIBCPP_ABI_NAMESPACE _LIBCPP_CONCAT(__,_LIBCPP_ABI_VERSION)
-#endif
-
-#if __cplusplus < 201103L
-#define _LIBCPP_CXX03_LANG
-#endif
-
-#ifndef __has_attribute
-#define __has_attribute(__x) 0
-#endif
-
-#ifndef __has_builtin
-#define __has_builtin(__x) 0
-#endif
-
-#ifndef __has_extension
-#define __has_extension(__x) 0
-#endif
-
-#ifndef __has_feature
-#define __has_feature(__x) 0
-#endif
-
-#ifndef __has_cpp_attribute
-#define __has_cpp_attribute(__x) 0
-#endif
-
-// '__is_identifier' returns '0' if '__x' is a reserved identifier provided by
-// the compiler and '1' otherwise.
-#ifndef __is_identifier
-#define __is_identifier(__x) 1
-#endif
-
-#ifndef __has_declspec_attribute
-#define __has_declspec_attribute(__x) 0
-#endif
-
-#define __has_keyword(__x) !(__is_identifier(__x))
-
-#ifndef __has_include
-#define __has_include(...) 0
-#endif
-
-#if defined(__clang__)
-#  define _LIBCPP_COMPILER_CLANG
-#  ifndef __apple_build_version__
-#    define _LIBCPP_CLANG_VER (__clang_major__ * 100 + __clang_minor__)
-#  endif
-#elif defined(__GNUC__)
-#  define _LIBCPP_COMPILER_GCC
-#elif defined(_MSC_VER)
-#  define _LIBCPP_COMPILER_MSVC
-#elif defined(__IBMCPP__)
-#  define _LIBCPP_COMPILER_IBM
-#endif
-
-#ifndef _LIBCPP_CLANG_VER
-#define _LIBCPP_CLANG_VER 0
-#endif
-
-// FIXME: ABI detection should be done via compiler builtin macros. This
-// is just a placeholder until Clang implements such macros. For now assume
-// that Windows compilers pretending to be MSVC++ target the Microsoft ABI,
-// and allow the user to explicitly specify the ABI to handle cases where this
-// heuristic falls short.
-#if defined(_LIBCPP_ABI_FORCE_ITANIUM) && defined(_LIBCPP_ABI_FORCE_MICROSOFT)
-#  error "Only one of _LIBCPP_ABI_FORCE_ITANIUM and _LIBCPP_ABI_FORCE_MICROSOFT can be defined"
-#elif defined(_LIBCPP_ABI_FORCE_ITANIUM)
-#  define _LIBCPP_ABI_ITANIUM
-#elif defined(_LIBCPP_ABI_FORCE_MICROSOFT)
-#  define _LIBCPP_ABI_MICROSOFT
-#else
-#  if defined(_WIN32) && defined(_MSC_VER)
-#    define _LIBCPP_ABI_MICROSOFT
-#  else
-#    define _LIBCPP_ABI_ITANIUM
-#  endif
-#endif
-
-// Need to detect which libc we're using if we're on Linux.
-#if defined(__linux__)
-#  include <features.h>
-#  if defined(__GLIBC_PREREQ)
-#    define _LIBCPP_GLIBC_PREREQ(a, b) __GLIBC_PREREQ(a, b)
-#  else
-#    define _LIBCPP_GLIBC_PREREQ(a, b) 0
-#  endif // defined(__GLIBC_PREREQ)
-#endif // defined(__linux__)
-
-#ifdef __LITTLE_ENDIAN__
-#  if __LITTLE_ENDIAN__
-#    define _LIBCPP_LITTLE_ENDIAN
-#  endif  // __LITTLE_ENDIAN__
-#endif  // __LITTLE_ENDIAN__
-
-#ifdef __BIG_ENDIAN__
-#  if __BIG_ENDIAN__
-#    define _LIBCPP_BIG_ENDIAN
-#  endif  // __BIG_ENDIAN__
-#endif  // __BIG_ENDIAN__
-
-#ifdef __BYTE_ORDER__
-#  if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-#    define _LIBCPP_LITTLE_ENDIAN
-#  elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#    define _LIBCPP_BIG_ENDIAN
-#  endif // __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#endif // __BYTE_ORDER__
-
-#ifdef __FreeBSD__
-#  include <sys/endian.h>
-#  if _BYTE_ORDER == _LITTLE_ENDIAN
-#    define _LIBCPP_LITTLE_ENDIAN
-#  else  // _BYTE_ORDER == _LITTLE_ENDIAN
-#    define _LIBCPP_BIG_ENDIAN
-#  endif  // _BYTE_ORDER == _LITTLE_ENDIAN
-#  ifndef __LONG_LONG_SUPPORTED
-#    define _LIBCPP_HAS_NO_LONG_LONG
-#  endif  // __LONG_LONG_SUPPORTED
-#endif  // __FreeBSD__
-
-#ifdef __NetBSD__
-#  include <sys/endian.h>
-#  if _BYTE_ORDER == _LITTLE_ENDIAN
-#    define _LIBCPP_LITTLE_ENDIAN
-#  else  // _BYTE_ORDER == _LITTLE_ENDIAN
-#    define _LIBCPP_BIG_ENDIAN
-#  endif  // _BYTE_ORDER == _LITTLE_ENDIAN
-#  define _LIBCPP_HAS_QUICK_EXIT
-#endif  // __NetBSD__
-
-#ifdef __OpenBSD__
-# include <sys/_endian.h>
-#  if _BYTE_ORDER == _LITTLE_ENDIAN
-#   define _LIBCPP_LITTLE_ENDIAN
-# else  // _BYTE_ORDER == _LITTLE_ENDIAN
-#   define _LIBCPP_BIG_ENDIAN
-# endif  // _BYTE_ORDER == _LITTLE_ENDIAN
-#endif  // __OpenBSD__
-
-#if defined(_WIN32)
-#  define _LIBCPP_WIN32API
-#  define _LIBCPP_LITTLE_ENDIAN
-#  define _LIBCPP_SHORT_WCHAR   1
-// Both MinGW and native MSVC provide a "MSVC"-like enviroment
-#  define _LIBCPP_MSVCRT_LIKE
-// If mingw not explicitly detected, assume using MS C runtime only if
-// a MS compatibility version is specified.
-#  if defined(_MSC_VER) && !defined(__MINGW32__)
-#    define _LIBCPP_MSVCRT // Using Microsoft's C Runtime library
-#  endif
-#  if (defined(_M_AMD64) || defined(__x86_64__)) || (defined(_M_ARM) || defined(__arm__))
-#    define _LIBCPP_HAS_BITSCAN64
-#  endif
-#  define _LIBCPP_HAS_OPEN_WITH_WCHAR
-#  if defined(_LIBCPP_MSVCRT)
-#    define _LIBCPP_HAS_QUICK_EXIT
-#  endif
-
-// Some CRT APIs are unavailable to store apps
-#  if defined(WINAPI_FAMILY)
-#    include <winapifamily.h>
-#    if !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_DESKTOP) &&                  \
-        (!defined(WINAPI_PARTITION_SYSTEM) ||                                  \
-         !WINAPI_FAMILY_PARTITION(WINAPI_PARTITION_SYSTEM))
-#      define _LIBCPP_WINDOWS_STORE_APP
-#    endif
-#  endif
-#endif // defined(_WIN32)
-
-#ifdef __sun__
-#  include <sys/isa_defs.h>
-#  ifdef _LITTLE_ENDIAN
-#    define _LIBCPP_LITTLE_ENDIAN
-#  else
-#    define _LIBCPP_BIG_ENDIAN
-#  endif
-#endif // __sun__
-
-#if defined(__CloudABI__) || defined(__OpenBSD__)
-   // Certain architectures provide arc4random(). Prefer using
-   // arc4random() over /dev/{u,}random to make it possible to obtain
-   // random data even when using sandboxing mechanisms such as chroots,
-   // Capsicum, etc.
-#  define _LIBCPP_USING_ARC4_RANDOM
-#elif defined(__Fuchsia__)
-#  define _LIBCPP_USING_GETENTROPY
-#elif defined(__native_client__)
-   // NaCl's sandbox (which PNaCl also runs in) doesn't allow filesystem access,
-   // including accesses to the special files under /dev. C++11's
-   // std::random_device is instead exposed through a NaCl syscall.
-#  define _LIBCPP_USING_NACL_RANDOM
-#elif defined(_LIBCPP_WIN32API)
-#  define _LIBCPP_USING_WIN32_RANDOM
-#else
-#  define _LIBCPP_USING_DEV_RANDOM
-#endif
-
-#if !defined(_LIBCPP_LITTLE_ENDIAN) && !defined(_LIBCPP_BIG_ENDIAN)
-#  include <endian.h>
-#  if __BYTE_ORDER == __LITTLE_ENDIAN
-#    define _LIBCPP_LITTLE_ENDIAN
-#  elif __BYTE_ORDER == __BIG_ENDIAN
-#    define _LIBCPP_BIG_ENDIAN
-#  else  // __BYTE_ORDER == __BIG_ENDIAN
-#    error unable to determine endian
-#  endif
-#endif  // !defined(_LIBCPP_LITTLE_ENDIAN) && !defined(_LIBCPP_BIG_ENDIAN)
-
-#if __has_attribute(__no_sanitize__) && !defined(_LIBCPP_COMPILER_GCC)
-#  define _LIBCPP_NO_CFI __attribute__((__no_sanitize__("cfi")))
-#else
-#  define _LIBCPP_NO_CFI
-#endif
-
-#if __ISO_C_VISIBLE >= 2011 || __cplusplus >= 201103L
-#  if defined(__FreeBSD__)
-#    define _LIBCPP_HAS_QUICK_EXIT
-#    define _LIBCPP_HAS_C11_FEATURES
-#  elif defined(__OpenBSD__)
-#    define _LIBCPP_HAS_TIMESPEC_GET
-#    define _LIBCPP_HAS_C11_FEATURES
-#  elif defined(__Fuchsia__)
-#    define _LIBCPP_HAS_QUICK_EXIT
-#    define _LIBCPP_HAS_TIMESPEC_GET
-#    define _LIBCPP_HAS_C11_FEATURES
-#  elif defined(__linux__)
-#    if !defined(_LIBCPP_HAS_MUSL_LIBC)
-#      if _LIBCPP_GLIBC_PREREQ(2, 15) || defined(__BIONIC__)
-#        define _LIBCPP_HAS_QUICK_EXIT
-#      endif
-#      if _LIBCPP_GLIBC_PREREQ(2, 17)
-#        define _LIBCPP_HAS_C11_FEATURES
-#        define _LIBCPP_HAS_TIMESPEC_GET
-#      endif
-#    else // defined(_LIBCPP_HAS_MUSL_LIBC)
-#      define _LIBCPP_HAS_QUICK_EXIT
-#      define _LIBCPP_HAS_TIMESPEC_GET
-#      define _LIBCPP_HAS_C11_FEATURES
-#    endif
-#  endif // __linux__
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-# define _LIBCPP_ALIGNOF(_Tp) alignof(_Tp)
-#elif defined(_LIBCPP_COMPILER_CLANG)
-# define _LIBCPP_ALIGNOF(_Tp) _Alignof(_Tp)
-#else
-// This definition is potentially buggy, but it's only taken with GCC in C++03,
-// which we barely support anyway. See llvm.org/PR39713
-# define _LIBCPP_ALIGNOF(_Tp) __alignof(_Tp)
-#endif
-
-#define _LIBCPP_PREFERRED_ALIGNOF(_Tp) __alignof(_Tp)
-
-#if defined(_LIBCPP_COMPILER_CLANG)
-
-// _LIBCPP_ALTERNATE_STRING_LAYOUT is an old name for
-// _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT left here for backward compatibility.
-#if (defined(__APPLE__) && !defined(__i386__) && !defined(__x86_64__) &&       \
-     (!defined(__arm__) || __ARM_ARCH_7K__ >= 2)) ||                           \
-    defined(_LIBCPP_ALTERNATE_STRING_LAYOUT)
-#define _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-#endif
-
-#if __has_feature(cxx_alignas)
-#  define _ALIGNAS_TYPE(x) alignas(x)
-#  define _ALIGNAS(x) alignas(x)
-#else
-#  define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
-#  define _ALIGNAS(x) __attribute__((__aligned__(x)))
-#endif
-
-#if __cplusplus < 201103L
-typedef __char16_t char16_t;
-typedef __char32_t char32_t;
-#endif
-
-#if !(__has_feature(cxx_exceptions)) && !defined(_LIBCPP_NO_EXCEPTIONS)
-#define _LIBCPP_NO_EXCEPTIONS
-#endif
-
-#if !(__has_feature(cxx_rtti)) && !defined(_LIBCPP_NO_RTTI)
-#define _LIBCPP_NO_RTTI
-#endif
-
-#if !(__has_feature(cxx_strong_enums))
-#define _LIBCPP_HAS_NO_STRONG_ENUMS
-#endif
-
-#if !(__has_feature(cxx_decltype))
-#define _LIBCPP_HAS_NO_DECLTYPE
-#endif
-
-#if __has_feature(cxx_attributes)
-#  define _LIBCPP_NORETURN [[noreturn]]
-#else
-#  define _LIBCPP_NORETURN __attribute__ ((noreturn))
-#endif
-
-#if !(__has_feature(cxx_lambdas))
-#define _LIBCPP_HAS_NO_LAMBDAS
-#endif
-
-#if !(__has_feature(cxx_nullptr))
-#  if (__has_extension(cxx_nullptr) || __has_keyword(__nullptr)) && defined(_LIBCPP_ABI_ALWAYS_USE_CXX11_NULLPTR)
-#    define nullptr __nullptr
-#  else
-#    define _LIBCPP_HAS_NO_NULLPTR
-#  endif
-#endif
-
-#if !(__has_feature(cxx_rvalue_references))
-#define _LIBCPP_HAS_NO_RVALUE_REFERENCES
-#endif
-
-#if !(__has_feature(cxx_auto_type))
-#define _LIBCPP_HAS_NO_AUTO_TYPE
-#endif
-
-#if !(__has_feature(cxx_variadic_templates))
-#define _LIBCPP_HAS_NO_VARIADICS
-#endif
-
-#if !(__has_feature(cxx_generalized_initializers))
-#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
-#endif
-
-#if __has_feature(is_base_of)
-#define _LIBCPP_HAS_IS_BASE_OF
-#endif
-
-#if __has_feature(is_final)
-#define _LIBCPP_HAS_IS_FINAL
-#endif
-
-// Objective-C++ features (opt-in)
-#if __has_feature(objc_arc)
-#define _LIBCPP_HAS_OBJC_ARC
-#endif
-
-#if __has_feature(objc_arc_weak)
-#define _LIBCPP_HAS_OBJC_ARC_WEAK
-#endif
-
-#if !(__has_feature(cxx_constexpr))
-#define _LIBCPP_HAS_NO_CONSTEXPR
-#endif
-
-#if !(__has_feature(cxx_relaxed_constexpr))
-#define _LIBCPP_HAS_NO_CXX14_CONSTEXPR
-#endif
-
-#if !(__has_feature(cxx_variable_templates))
-#define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
-#endif
-
-#if !(__has_feature(cxx_noexcept))
-#define _LIBCPP_HAS_NO_NOEXCEPT
-#endif
-
-#if __has_feature(underlying_type)
-#define _LIBCPP_UNDERLYING_TYPE(T) __underlying_type(T)
-#endif
-
-#if __has_feature(is_literal)
-#define _LIBCPP_IS_LITERAL(T) __is_literal(T)
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_ASAN) && !__has_feature(address_sanitizer)
-#define _LIBCPP_HAS_NO_ASAN
-#endif
-
-// Allow for build-time disabling of unsigned integer sanitization
-#if !defined(_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK) && __has_attribute(no_sanitize)
-#define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK __attribute__((__no_sanitize__("unsigned-integer-overflow")))
-#endif
-
-#if __has_builtin(__builtin_launder)
-#define _LIBCPP_COMPILER_HAS_BUILTIN_LAUNDER
-#endif
-
-#if !__is_identifier(__has_unique_object_representations)
-#define _LIBCPP_HAS_UNIQUE_OBJECT_REPRESENTATIONS
-#endif
-
-#define _LIBCPP_ALWAYS_INLINE __attribute__ ((__always_inline__))
-
-// No apple compilers support ""d and ""y at this time.
-#if _LIBCPP_CLANG_VER < 800 || defined(__apple_build_version__)
-#define	_LIBCPP_HAS_NO_CXX20_CHRONO_LITERALS
-#endif
-
-#elif defined(_LIBCPP_COMPILER_GCC)
-
-#define _ALIGNAS(x) __attribute__((__aligned__(x)))
-#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
-
-#define _LIBCPP_NORETURN __attribute__((noreturn))
-
-#if _GNUC_VER >= 407
-#define _LIBCPP_UNDERLYING_TYPE(T) __underlying_type(T)
-#define _LIBCPP_IS_LITERAL(T) __is_literal_type(T)
-#define _LIBCPP_HAS_IS_FINAL
-#endif
-
-#if defined(__GNUC__) && _GNUC_VER >= 403
-#define _LIBCPP_HAS_IS_BASE_OF
-#endif
-
-#if !__EXCEPTIONS && !defined(_LIBCPP_NO_EXCEPTIONS)
-#define _LIBCPP_NO_EXCEPTIONS
-#endif
-
-// constexpr was added to GCC in 4.6.
-#if _GNUC_VER < 406
-#  define _LIBCPP_HAS_NO_CONSTEXPR
-// Can only use constexpr in c++11 mode.
-#elif !defined(__GXX_EXPERIMENTAL_CXX0X__) && __cplusplus < 201103L
-#  define _LIBCPP_HAS_NO_CONSTEXPR
-#endif
-
-// Determine if GCC supports relaxed constexpr
-#if !defined(__cpp_constexpr) || __cpp_constexpr < 201304L
-#define _LIBCPP_HAS_NO_CXX14_CONSTEXPR
-#endif
-
-// GCC 5 will support variable templates
-#if !defined(__cpp_variable_templates) || __cpp_variable_templates < 201304L
-#define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
-#endif
-
-#ifndef __GXX_EXPERIMENTAL_CXX0X__
-
-#define _LIBCPP_HAS_NO_DECLTYPE
-#define _LIBCPP_HAS_NO_NULLPTR
-#define _LIBCPP_HAS_NO_UNICODE_CHARS
-#define _LIBCPP_HAS_NO_VARIADICS
-#define _LIBCPP_HAS_NO_RVALUE_REFERENCES
-#define _LIBCPP_HAS_NO_STRONG_ENUMS
-#define _LIBCPP_HAS_NO_NOEXCEPT
-
-#else  // __GXX_EXPERIMENTAL_CXX0X__
-
-#if _GNUC_VER < 403
-#define _LIBCPP_HAS_NO_RVALUE_REFERENCES
-#endif
-
-
-#if _GNUC_VER < 404
-#define _LIBCPP_HAS_NO_DECLTYPE
-#define _LIBCPP_HAS_NO_UNICODE_CHARS
-#define _LIBCPP_HAS_NO_VARIADICS
-#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
-#endif  // _GNUC_VER < 404
-
-#if _GNUC_VER < 406
-#define _LIBCPP_HAS_NO_NOEXCEPT
-#define _LIBCPP_HAS_NO_NULLPTR
-#endif
-
-#endif  // __GXX_EXPERIMENTAL_CXX0X__
-
-#if !defined(_LIBCPP_HAS_NO_ASAN) && !defined(__SANITIZE_ADDRESS__)
-#define _LIBCPP_HAS_NO_ASAN
-#endif
-
-#if _GNUC_VER >= 700
-#define _LIBCPP_COMPILER_HAS_BUILTIN_LAUNDER
-#endif
-
-#if _GNUC_VER >= 700
-#define _LIBCPP_HAS_UNIQUE_OBJECT_REPRESENTATIONS
-#endif
-
-#define _LIBCPP_ALWAYS_INLINE __attribute__ ((__always_inline__))
-
-#elif defined(_LIBCPP_COMPILER_MSVC)
-
-#define _LIBCPP_TOSTRING2(x) #x
-#define _LIBCPP_TOSTRING(x) _LIBCPP_TOSTRING2(x)
-#define _LIBCPP_WARNING(x) __pragma(message(__FILE__ "(" _LIBCPP_TOSTRING(__LINE__) ") : warning note: " x))
-
-#if _MSC_VER < 1900
-#error "MSVC versions prior to Visual Studio 2015 are not supported"
-#endif
-
-#define _LIBCPP_HAS_IS_BASE_OF
-#define _LIBCPP_HAS_NO_CONSTEXPR
-#define _LIBCPP_HAS_NO_CXX14_CONSTEXPR
-#define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
-#define _LIBCPP_HAS_NO_NOEXCEPT
-#define __alignof__ __alignof
-#define _LIBCPP_NORETURN __declspec(noreturn)
-#define _ALIGNAS(x) __declspec(align(x))
-#define _ALIGNAS_TYPE(x) alignas(x)
-#define _LIBCPP_HAS_NO_VARIADICS
-
-#define _LIBCPP_WEAK
-
-#define _LIBCPP_HAS_NO_ASAN
-
-#define _LIBCPP_ALWAYS_INLINE __forceinline
-
-#define _LIBCPP_HAS_NO_VECTOR_EXTENSION
-
-#elif defined(_LIBCPP_COMPILER_IBM)
-
-#define _ALIGNAS(x) __attribute__((__aligned__(x)))
-#define _ALIGNAS_TYPE(x) __attribute__((__aligned__(_LIBCPP_ALIGNOF(x))))
-#define _ATTRIBUTE(x) __attribute__((x))
-#define _LIBCPP_NORETURN __attribute__((noreturn))
-
-#define _LIBCPP_HAS_NO_GENERALIZED_INITIALIZERS
-#define _LIBCPP_HAS_NO_NOEXCEPT
-#define _LIBCPP_HAS_NO_NULLPTR
-#define _LIBCPP_HAS_NO_UNICODE_CHARS
-#define _LIBCPP_HAS_IS_BASE_OF
-#define _LIBCPP_HAS_IS_FINAL
-#define _LIBCPP_HAS_NO_VARIABLE_TEMPLATES
-
-#if defined(_AIX)
-#define __MULTILOCALE_API
-#endif
-
-#define _LIBCPP_HAS_NO_ASAN
-
-#define _LIBCPP_ALWAYS_INLINE __attribute__ ((__always_inline__))
-
-#define _LIBCPP_HAS_NO_VECTOR_EXTENSION
-
-#endif // _LIBCPP_COMPILER_[CLANG|GCC|MSVC|IBM]
-
-#if defined(_LIBCPP_OBJECT_FORMAT_COFF)
-
-#ifdef _DLL
-#  define _LIBCPP_CRT_FUNC __declspec(dllimport)
-#else
-#  define _LIBCPP_CRT_FUNC
-#endif
-
-#if defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-#  define _LIBCPP_DLL_VIS
-#  define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
-#  define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
-#  define _LIBCPP_OVERRIDABLE_FUNC_VIS
-#  define _LIBCPP_EXPORTED_FROM_ABI
-#elif defined(_LIBCPP_BUILDING_LIBRARY)
-#  define _LIBCPP_DLL_VIS __declspec(dllexport)
-#  define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
-#  define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS _LIBCPP_DLL_VIS
-#  define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_DLL_VIS
-#  define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllexport)
-#else
-#  define _LIBCPP_DLL_VIS __declspec(dllimport)
-#  define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS _LIBCPP_DLL_VIS
-#  define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
-#  define _LIBCPP_OVERRIDABLE_FUNC_VIS
-#  define _LIBCPP_EXPORTED_FROM_ABI __declspec(dllimport)
-#endif
-
-#define _LIBCPP_TYPE_VIS            _LIBCPP_DLL_VIS
-#define _LIBCPP_FUNC_VIS            _LIBCPP_DLL_VIS
-#define _LIBCPP_EXCEPTION_ABI       _LIBCPP_DLL_VIS
-#define _LIBCPP_HIDDEN
-#define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-#define _LIBCPP_TEMPLATE_VIS
-#define _LIBCPP_ENUM_VIS
-
-#endif // defined(_LIBCPP_OBJECT_FORMAT_COFF)
-
-#ifndef _LIBCPP_HIDDEN
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-#    define _LIBCPP_HIDDEN __attribute__ ((__visibility__("hidden")))
-#  else
-#    define _LIBCPP_HIDDEN
-#  endif
-#endif
-
-#ifndef _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-// The inline should be removed once PR32114 is resolved
-#    define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS inline _LIBCPP_HIDDEN
-#  else
-#    define _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-#  endif
-#endif
-
-#ifndef _LIBCPP_FUNC_VIS
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-#    define _LIBCPP_FUNC_VIS __attribute__ ((__visibility__("default")))
-#  else
-#    define _LIBCPP_FUNC_VIS
-#  endif
-#endif
-
-#ifndef _LIBCPP_TYPE_VIS
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-#    define _LIBCPP_TYPE_VIS __attribute__ ((__visibility__("default")))
-#  else
-#    define _LIBCPP_TYPE_VIS
-#  endif
-#endif
-
-#ifndef _LIBCPP_TEMPLATE_VIS
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-#    if __has_attribute(__type_visibility__)
-#      define _LIBCPP_TEMPLATE_VIS __attribute__ ((__type_visibility__("default")))
-#    else
-#      define _LIBCPP_TEMPLATE_VIS __attribute__ ((__visibility__("default")))
-#    endif
-#  else
-#    define _LIBCPP_TEMPLATE_VIS
-#  endif
-#endif
-
-#ifndef _LIBCPP_EXPORTED_FROM_ABI
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-#    define _LIBCPP_EXPORTED_FROM_ABI __attribute__((__visibility__("default")))
-#  else
-#    define _LIBCPP_EXPORTED_FROM_ABI
-#  endif
-#endif
-
-#ifndef _LIBCPP_OVERRIDABLE_FUNC_VIS
-#define _LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_FUNC_VIS
-#endif
-
-#ifndef _LIBCPP_EXCEPTION_ABI
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS)
-#    define _LIBCPP_EXCEPTION_ABI __attribute__ ((__visibility__("default")))
-#  else
-#    define _LIBCPP_EXCEPTION_ABI
-#  endif
-#endif
-
-#ifndef _LIBCPP_ENUM_VIS
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && __has_attribute(__type_visibility__)
-#    define _LIBCPP_ENUM_VIS __attribute__ ((__type_visibility__("default")))
-#  else
-#    define _LIBCPP_ENUM_VIS
-#  endif
-#endif
-
-#ifndef _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
-#  if !defined(_LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS) && __has_attribute(__type_visibility__)
-#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __attribute__ ((__visibility__("default")))
-#  else
-#    define _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS
-#  endif
-#endif
-
-#ifndef _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
-#define _LIBCPP_CLASS_TEMPLATE_INSTANTIATION_VIS
-#endif
-
-#if __has_attribute(internal_linkage)
-#  define _LIBCPP_INTERNAL_LINKAGE __attribute__ ((internal_linkage))
-#else
-#  define _LIBCPP_INTERNAL_LINKAGE _LIBCPP_ALWAYS_INLINE
-#endif
-
-#if __has_attribute(exclude_from_explicit_instantiation)
-#  define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION __attribute__ ((__exclude_from_explicit_instantiation__))
-#else
-   // Try to approximate the effect of exclude_from_explicit_instantiation
-   // (which is that entities are not assumed to be provided by explicit
-   // template instantitations in the dylib) by always inlining those entities.
-#  define _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION _LIBCPP_ALWAYS_INLINE
-#endif
-
-#ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU
-#  ifndef _LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT
-#    define _LIBCPP_HIDE_FROM_ABI_PER_TU 0
-#  else
-#    define _LIBCPP_HIDE_FROM_ABI_PER_TU 1
-#  endif
-#endif
-
-#ifndef _LIBCPP_HIDE_FROM_ABI
-#  if _LIBCPP_HIDE_FROM_ABI_PER_TU
-#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_INTERNAL_LINKAGE
-#  else
-#    define _LIBCPP_HIDE_FROM_ABI _LIBCPP_HIDDEN _LIBCPP_EXCLUDE_FROM_EXPLICIT_INSTANTIATION
-#  endif
-#endif
-
-#ifdef _LIBCPP_BUILDING_LIBRARY
-#  if _LIBCPP_ABI_VERSION > 1
-#    define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
-#  else
-#    define _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-#  endif
-#else
-#  define _LIBCPP_HIDE_FROM_ABI_AFTER_V1 _LIBCPP_HIDE_FROM_ABI
-#endif
-
-// Just so we can migrate to the new macros gradually.
-#define _LIBCPP_INLINE_VISIBILITY _LIBCPP_HIDE_FROM_ABI
-
-// Inline namespaces are available in Clang/GCC/MSVC regardless of C++ dialect.
-#define _LIBCPP_BEGIN_NAMESPACE_STD namespace std { inline namespace _LIBCPP_ABI_NAMESPACE {
-#define _LIBCPP_END_NAMESPACE_STD  } }
-#define _VSTD std::_LIBCPP_ABI_NAMESPACE
-_LIBCPP_BEGIN_NAMESPACE_STD _LIBCPP_END_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER >= 17
-#define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM \
-  _LIBCPP_BEGIN_NAMESPACE_STD inline namespace __fs { namespace filesystem {
-#else
-#define _LIBCPP_BEGIN_NAMESPACE_FILESYSTEM \
-  _LIBCPP_BEGIN_NAMESPACE_STD namespace __fs { namespace filesystem {
-#endif
-
-#define _LIBCPP_END_NAMESPACE_FILESYSTEM \
-  _LIBCPP_END_NAMESPACE_STD } }
-
-#define _VSTD_FS _VSTD::__fs::filesystem
-
-#ifndef _LIBCPP_PREFERRED_OVERLOAD
-#  if __has_attribute(__enable_if__)
-#    define _LIBCPP_PREFERRED_OVERLOAD __attribute__ ((__enable_if__(true, "")))
-#  endif
-#endif
-
-#ifndef _LIBCPP_HAS_NO_NOEXCEPT
-#  define _NOEXCEPT noexcept
-#  define _NOEXCEPT_(x) noexcept(x)
-#else
-#  define _NOEXCEPT throw()
-#  define _NOEXCEPT_(x)
-#endif
-
-#if defined(_LIBCPP_DEBUG_USE_EXCEPTIONS)
-#  if !defined(_LIBCPP_DEBUG)
-#    error cannot use _LIBCPP_DEBUG_USE_EXCEPTIONS unless _LIBCPP_DEBUG is defined
-#  endif
-#  ifdef _LIBCPP_HAS_NO_NOEXCEPT
-#    define _NOEXCEPT_DEBUG
-#    define _NOEXCEPT_DEBUG_(x)
-#  else
-#    define _NOEXCEPT_DEBUG noexcept(false)
-#    define _NOEXCEPT_DEBUG_(x) noexcept(false)
-#  endif
-#else
-#  define _NOEXCEPT_DEBUG _NOEXCEPT
-#  define _NOEXCEPT_DEBUG_(x) _NOEXCEPT_(x)
-#endif
-
-#ifdef _LIBCPP_HAS_NO_UNICODE_CHARS
-typedef unsigned short char16_t;
-typedef unsigned int   char32_t;
-#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
-
-#ifndef __SIZEOF_INT128__
-#define _LIBCPP_HAS_NO_INT128
-#endif
-
-#ifdef _LIBCPP_CXX03_LANG
-#  if __has_extension(c_static_assert)
-#    define static_assert(__b, __m) _Static_assert(__b, __m)
-#  else
-extern "C++" {
-template <bool> struct __static_assert_test;
-template <> struct __static_assert_test<true> {};
-template <unsigned> struct __static_assert_check {};
-}
-#    define static_assert(__b, __m) \
-       typedef __static_assert_check<sizeof(__static_assert_test<(__b)>)> \
-       _LIBCPP_CONCAT(__t, __LINE__)
-#  endif // __has_extension(c_static_assert)
-#endif  // _LIBCPP_CXX03_LANG
-
-#ifdef _LIBCPP_HAS_NO_DECLTYPE
-// GCC 4.6 provides __decltype in all standard modes.
-#  if __has_keyword(__decltype) || _LIBCPP_CLANG_VER >= 304 || _GNUC_VER >= 406
-#    define decltype(__x) __decltype(__x)
-#  else
-#    define decltype(__x) __typeof__(__x)
-#  endif
-#endif
-
-#ifdef _LIBCPP_HAS_NO_CONSTEXPR
-#  define _LIBCPP_CONSTEXPR
-#else
-#  define _LIBCPP_CONSTEXPR constexpr
-#endif
-
-#ifdef _LIBCPP_CXX03_LANG
-#  define _LIBCPP_DEFAULT {}
-#else
-#  define _LIBCPP_DEFAULT = default;
-#endif
-
-#ifdef _LIBCPP_CXX03_LANG
-#  define _LIBCPP_EQUAL_DELETE
-#else
-#  define _LIBCPP_EQUAL_DELETE = delete
-#endif
-
-#ifdef __GNUC__
-#  define _NOALIAS __attribute__((__malloc__))
-#else
-#  define _NOALIAS
-#endif
-
-#if __has_feature(cxx_explicit_conversions) || defined(__IBMCPP__) || \
-    (!defined(_LIBCPP_CXX03_LANG) && defined(__GNUC__)) // All supported GCC versions
-#  define _LIBCPP_EXPLICIT explicit
-#else
-#  define _LIBCPP_EXPLICIT
-#endif
-
-#if !__has_builtin(__builtin_operator_new) || !__has_builtin(__builtin_operator_delete)
-#define _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
-#endif
-
-#ifdef _LIBCPP_HAS_NO_STRONG_ENUMS
-#  define _LIBCPP_DECLARE_STRONG_ENUM(x) struct _LIBCPP_TYPE_VIS x { enum __lx
-#  define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x) \
-     __lx __v_; \
-     _LIBCPP_INLINE_VISIBILITY x(__lx __v) : __v_(__v) {} \
-     _LIBCPP_INLINE_VISIBILITY explicit x(int __v) : __v_(static_cast<__lx>(__v)) {} \
-     _LIBCPP_INLINE_VISIBILITY operator int() const {return __v_;} \
-     };
-#else  // _LIBCPP_HAS_NO_STRONG_ENUMS
-#  define _LIBCPP_DECLARE_STRONG_ENUM(x) enum class _LIBCPP_ENUM_VIS x
-#  define _LIBCPP_DECLARE_STRONG_ENUM_EPILOG(x)
-#endif  // _LIBCPP_HAS_NO_STRONG_ENUMS
-
-#ifdef _LIBCPP_DEBUG
-#  if _LIBCPP_DEBUG == 0
-#    define _LIBCPP_DEBUG_LEVEL 1
-#  elif _LIBCPP_DEBUG == 1
-#    define _LIBCPP_DEBUG_LEVEL 2
-#  else
-#    error Supported values for _LIBCPP_DEBUG are 0 and 1
-#  endif
-#  if !defined(_LIBCPP_BUILDING_LIBRARY)
-#    define _LIBCPP_EXTERN_TEMPLATE(...)
-#  endif
-#endif
-
-#ifdef _LIBCPP_DISABLE_EXTERN_TEMPLATE
-#define _LIBCPP_EXTERN_TEMPLATE(...)
-#define _LIBCPP_EXTERN_TEMPLATE2(...)
-#endif
-
-#ifndef _LIBCPP_EXTERN_TEMPLATE
-#define _LIBCPP_EXTERN_TEMPLATE(...) extern template __VA_ARGS__;
-#endif
-
-#ifndef _LIBCPP_EXTERN_TEMPLATE2
-#define _LIBCPP_EXTERN_TEMPLATE2(...) extern template __VA_ARGS__;
-#endif
-
-#if defined(__APPLE__) && defined(__LP64__) && !defined(__x86_64__)
-#define _LIBCPP_NONUNIQUE_RTTI_BIT (1ULL << 63)
-#endif
-
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(_LIBCPP_MSVCRT_LIKE) || \
-    defined(__sun__) || defined(__NetBSD__) || defined(__CloudABI__)
-#define _LIBCPP_LOCALE__L_EXTENSIONS 1
-#endif
-
-#if defined(__unix__) || (defined(__APPLE__) && defined(__MACH__))
-// Most unix variants have catopen.  These are the specific ones that don't.
-#  if !defined(__BIONIC__) && !defined(_NEWLIB_VERSION)
-#    define _LIBCPP_HAS_CATOPEN 1
-#  endif
-#endif
-
-#ifdef __FreeBSD__
-#define _DECLARE_C99_LDBL_MATH 1
-#endif
-
-// If we are getting operator new from the MSVC CRT, then allocation overloads
-// for align_val_t were added in 19.12, aka VS 2017 version 15.3.
-#if defined(_LIBCPP_MSVCRT) && defined(_MSC_VER) && _MSC_VER < 1912
-#  define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-#elif defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
-#  define _LIBCPP_DEFER_NEW_TO_VCRUNTIME
-#  if !defined(__cpp_aligned_new)
-     // We're defering to Microsoft's STL to provide aligned new et al. We don't
-     // have it unless the language feature test macro is defined.
-#    define _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-#  endif
-#endif
-
-#if defined(__APPLE__)
-#  if !defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && \
-      defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__)
-#    define __MAC_OS_X_VERSION_MIN_REQUIRED __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__
-#  endif
-#endif // defined(__APPLE__)
-
-#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION) && \
-    (defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION) || \
-    (!defined(__cpp_aligned_new) || __cpp_aligned_new < 201606))
-#  define _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
-#endif
-
-#if defined(__APPLE__) || defined(__FreeBSD__)
-#define _LIBCPP_HAS_DEFAULTRUNELOCALE
-#endif
-
-#if defined(__APPLE__) || defined(__FreeBSD__) || defined(__sun__)
-#define _LIBCPP_WCTYPE_IS_MASK
-#endif
-
-#if _LIBCPP_STD_VER <= 17 || !defined(__cpp_char8_t)
-#define _LIBCPP_NO_HAS_CHAR8_T
-#endif
-
-// Deprecation macros.
-// Deprecations warnings are only enabled when _LIBCPP_ENABLE_DEPRECATION_WARNINGS is defined.
-#if defined(_LIBCPP_ENABLE_DEPRECATION_WARNINGS)
-#  if __has_attribute(deprecated)
-#    define _LIBCPP_DEPRECATED __attribute__ ((deprecated))
-#  elif _LIBCPP_STD_VER > 11
-#    define _LIBCPP_DEPRECATED [[deprecated]]
-#  else
-#    define _LIBCPP_DEPRECATED
-#  endif
-#else
-#  define _LIBCPP_DEPRECATED
-#endif
-
-#if !defined(_LIBCPP_CXX03_LANG)
-#  define _LIBCPP_DEPRECATED_IN_CXX11 _LIBCPP_DEPRECATED
-#else
-#  define _LIBCPP_DEPRECATED_IN_CXX11
-#endif
-
-#if _LIBCPP_STD_VER >= 14
-#  define _LIBCPP_DEPRECATED_IN_CXX14 _LIBCPP_DEPRECATED
-#else
-#  define _LIBCPP_DEPRECATED_IN_CXX14
-#endif
-
-#if _LIBCPP_STD_VER >= 17
-#  define _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_DEPRECATED
-#else
-#  define _LIBCPP_DEPRECATED_IN_CXX17
-#endif
-
-#if _LIBCPP_STD_VER <= 11
-#  define _LIBCPP_EXPLICIT_AFTER_CXX11
-#else
-#  define _LIBCPP_EXPLICIT_AFTER_CXX11 explicit
-#endif
-
-#if _LIBCPP_STD_VER > 11 && !defined(_LIBCPP_HAS_NO_CXX14_CONSTEXPR)
-#  define _LIBCPP_CONSTEXPR_AFTER_CXX11 constexpr
-#else
-#  define _LIBCPP_CONSTEXPR_AFTER_CXX11
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_CXX14_CONSTEXPR)
-#  define _LIBCPP_CONSTEXPR_AFTER_CXX14 constexpr
-#else
-#  define _LIBCPP_CONSTEXPR_AFTER_CXX14
-#endif
-
-#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CXX14_CONSTEXPR)
-#  define _LIBCPP_CONSTEXPR_AFTER_CXX17 constexpr
-#else
-#  define _LIBCPP_CONSTEXPR_AFTER_CXX17
-#endif
-
-// The _LIBCPP_NODISCARD_ATTRIBUTE should only be used to define other
-// NODISCARD macros to the correct attribute.
-#if __has_cpp_attribute(nodiscard) || defined(_LIBCPP_COMPILER_MSVC)
-#  define _LIBCPP_NODISCARD_ATTRIBUTE [[nodiscard]]
-#elif defined(_LIBCPP_COMPILER_CLANG) && !defined(_LIBCPP_CXX03_LANG)
-#  define _LIBCPP_NODISCARD_ATTRIBUTE [[clang::warn_unused_result]]
-#else
-// We can't use GCC's [[gnu::warn_unused_result]] and
-// __attribute__((warn_unused_result)), because GCC does not silence them via
-// (void) cast.
-#  define _LIBCPP_NODISCARD_ATTRIBUTE
-#endif
-
-// _LIBCPP_NODISCARD_EXT may be used to apply [[nodiscard]] to entities not
-// specified as such as an extension.
-#if defined(_LIBCPP_ENABLE_NODISCARD) && !defined(_LIBCPP_DISABLE_NODISCARD_EXT)
-#  define _LIBCPP_NODISCARD_EXT _LIBCPP_NODISCARD_ATTRIBUTE
-#else
-#  define _LIBCPP_NODISCARD_EXT
-#endif
-
-#if !defined(_LIBCPP_DISABLE_NODISCARD_AFTER_CXX17) && \
-    (_LIBCPP_STD_VER > 17 || defined(_LIBCPP_ENABLE_NODISCARD))
-#  define _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_NODISCARD_ATTRIBUTE
-#else
-#  define _LIBCPP_NODISCARD_AFTER_CXX17
-#endif
-
-#if _LIBCPP_STD_VER > 14 && defined(__cpp_inline_variables) && (__cpp_inline_variables >= 201606L)
-#  define _LIBCPP_INLINE_VAR inline
-#else
-#  define _LIBCPP_INLINE_VAR
-#endif
-
-#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-#  define _LIBCPP_EXPLICIT_MOVE(x) _VSTD::move(x)
-#else
-#  define _LIBCPP_EXPLICIT_MOVE(x) (x)
-#endif
-
-#ifndef _LIBCPP_CONSTEXPR_IF_NODEBUG
-#if defined(_LIBCPP_DEBUG) || defined(_LIBCPP_HAS_NO_CXX14_CONSTEXPR)
-#define _LIBCPP_CONSTEXPR_IF_NODEBUG
-#else
-#define _LIBCPP_CONSTEXPR_IF_NODEBUG constexpr
-#endif
-#endif
-
-#ifndef _LIBCPP_HAS_NO_ASAN
-_LIBCPP_FUNC_VIS extern "C" void __sanitizer_annotate_contiguous_container(
-  const void *, const void *, const void *, const void *);
-#endif
-
-// Try to find out if RTTI is disabled.
-// g++ and cl.exe have RTTI on by default and define a macro when it is.
-// g++ only defines the macro in 4.3.2 and onwards.
-#if !defined(_LIBCPP_NO_RTTI)
-#  if defined(__GNUC__) && \
-      ((__GNUC__ >= 5) || \
-       (__GNUC__ == 4 && (__GNUC_MINOR__ >= 3 || __GNUC_PATCHLEVEL__ >= 2))) && \
-      !defined(__GXX_RTTI)
-#    define _LIBCPP_NO_RTTI
-#  elif defined(_LIBCPP_COMPILER_MSVC) && !defined(_CPPRTTI)
-#    define _LIBCPP_NO_RTTI
-#  endif
-#endif
-
-#ifndef _LIBCPP_WEAK
-#define _LIBCPP_WEAK __attribute__((__weak__))
-#endif
-
-// Thread API
-#if !defined(_LIBCPP_HAS_NO_THREADS) && \
-    !defined(_LIBCPP_HAS_THREAD_API_PTHREAD) && \
-    !defined(_LIBCPP_HAS_THREAD_API_WIN32) && \
-    !defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
-#  if defined(__FreeBSD__) || \
-      defined(__Fuchsia__) || \
-      defined(__NetBSD__) || \
-      defined(__linux__) || \
-      defined(__GNU__) || \
-      defined(__APPLE__) || \
-      defined(__CloudABI__) || \
-      defined(__sun__) || \
-      (defined(__MINGW32__) && __has_include(<pthread.h>)) || \
-      defined(__OpenBSD__)
-#    define _LIBCPP_HAS_THREAD_API_PTHREAD
-#  elif defined(_LIBCPP_WIN32API)
-#    define _LIBCPP_HAS_THREAD_API_WIN32
-#  else
-#    error "No thread API"
-#  endif // _LIBCPP_HAS_THREAD_API
-#endif // _LIBCPP_HAS_NO_THREADS
-
-#if defined(_LIBCPP_HAS_NO_THREADS) && defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
-#error _LIBCPP_HAS_THREAD_API_PTHREAD may only be defined when \
-       _LIBCPP_HAS_NO_THREADS is not defined.
-#endif
-
-#if defined(_LIBCPP_HAS_NO_THREADS) && defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
-#error _LIBCPP_HAS_THREAD_API_EXTERNAL may not be defined when \
-       _LIBCPP_HAS_NO_THREADS is defined.
-#endif
-
-#if defined(_LIBCPP_HAS_NO_MONOTONIC_CLOCK) && !defined(_LIBCPP_HAS_NO_THREADS)
-#error _LIBCPP_HAS_NO_MONOTONIC_CLOCK may only be defined when \
-       _LIBCPP_HAS_NO_THREADS is defined.
-#endif
-
-// Systems that use capability-based security (FreeBSD with Capsicum,
-// Nuxi CloudABI) may only provide local filesystem access (using *at()).
-// Functions like open(), rename(), unlink() and stat() should not be
-// used, as they attempt to access the global filesystem namespace.
-#ifdef __CloudABI__
-#define _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-#endif
-
-// CloudABI is intended for running networked services. Processes do not
-// have standard input and output channels.
-#ifdef __CloudABI__
-#define _LIBCPP_HAS_NO_STDIN
-#define _LIBCPP_HAS_NO_STDOUT
-#endif
-
-#if defined(__BIONIC__) || defined(__CloudABI__) ||                            \
-    defined(__Fuchsia__) || defined(_LIBCPP_HAS_MUSL_LIBC) ||                  \
-    defined(__OpenBSD__)
-#define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE
-#endif
-
-// Thread-unsafe functions such as strtok() and localtime()
-// are not available.
-#ifdef __CloudABI__
-#define _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
-#endif
-
-#if __has_feature(cxx_atomic) || __has_extension(c_atomic) || __has_keyword(_Atomic)
-#  define _LIBCPP_HAS_C_ATOMIC_IMP
-#elif _GNUC_VER > 407
-#  define _LIBCPP_HAS_GCC_ATOMIC_IMP
-#endif
-
-#if (!defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP)) \
-     || defined(_LIBCPP_HAS_NO_THREADS)
-#define _LIBCPP_HAS_NO_ATOMIC_HEADER
-#endif
-
-#ifndef _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-#define _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-#endif
-
-#if defined(_LIBCPP_ENABLE_THREAD_SAFETY_ANNOTATIONS)
-#  if defined(__clang__) && __has_attribute(acquire_capability)
-// Work around the attribute handling in clang.  When both __declspec and
-// __attribute__ are present, the processing goes awry preventing the definition
-// of the types.
-#    if !defined(_LIBCPP_OBJECT_FORMAT_COFF)
-#      define _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
-#    endif
-#  endif
-#endif
-
-#if __has_attribute(require_constant_initialization)
-#  define _LIBCPP_SAFE_STATIC __attribute__((__require_constant_initialization__))
-#else
-#  define _LIBCPP_SAFE_STATIC
-#endif
-
-#if !__has_builtin(__builtin_addressof) && _GNUC_VER < 700
-#define _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
-#  if defined(_LIBCPP_MSVCRT) || defined(_NEWLIB_VERSION)
-#    define _LIBCPP_HAS_NO_OFF_T_FUNCTIONS
-#  endif
-#endif
-
-#if __has_attribute(diagnose_if) && !defined(_LIBCPP_DISABLE_ADDITIONAL_DIAGNOSTICS)
-#  define _LIBCPP_DIAGNOSE_WARNING(...) \
-     __attribute__((diagnose_if(__VA_ARGS__, "warning")))
-#  define _LIBCPP_DIAGNOSE_ERROR(...) \
-     __attribute__((diagnose_if(__VA_ARGS__, "error")))
-#else
-#  define _LIBCPP_DIAGNOSE_WARNING(...)
-#  define _LIBCPP_DIAGNOSE_ERROR(...)
-#endif
-
-// Use a function like macro to imply that it must be followed by a semicolon
-#if __cplusplus > 201402L && __has_cpp_attribute(fallthrough)
-#  define _LIBCPP_FALLTHROUGH() [[fallthrough]]
-#elif __has_cpp_attribute(clang::fallthrough)
-#  define _LIBCPP_FALLTHROUGH() [[clang::fallthrough]]
-#elif __has_attribute(fallthough) || _GNUC_VER >= 700
-#  define _LIBCPP_FALLTHROUGH() __attribute__((__fallthrough__))
-#else
-#  define _LIBCPP_FALLTHROUGH() ((void)0)
-#endif
-
-#if defined(_LIBCPP_ABI_MICROSOFT) && \
-    (defined(_LIBCPP_COMPILER_MSVC) || __has_declspec_attribute(empty_bases))
-#  define _LIBCPP_DECLSPEC_EMPTY_BASES __declspec(empty_bases)
-#else
-#  define _LIBCPP_DECLSPEC_EMPTY_BASES
-#endif
-
-#if defined(_LIBCPP_ENABLE_CXX17_REMOVED_FEATURES)
-#define _LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR
-#define _LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS
-#define _LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE
-#define _LIBCPP_ENABLE_CXX17_REMOVED_BINDERS
-#endif // _LIBCPP_ENABLE_CXX17_REMOVED_FEATURES
-
-#if !defined(__cpp_deduction_guides) || __cpp_deduction_guides < 201611
-#define _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-#endif
-
-#if !__has_keyword(__is_aggregate) && (_GNUC_VER_NEW < 7001)
-#define _LIBCPP_HAS_NO_IS_AGGREGATE
-#endif
-
-#if !defined(__cpp_coroutines) || __cpp_coroutines < 201703L
-#define _LIBCPP_HAS_NO_COROUTINES
-#endif
-
-// FIXME: Correct this macro when either (A) a feature test macro for the
-// spaceship operator is provided, or (B) a compiler provides a complete
-// implementation.
-#define _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-
-// Decide whether to use availability macros.
-#if !defined(_LIBCPP_BUILDING_LIBRARY) &&                                      \
-    !defined(_LIBCPP_DISABLE_AVAILABILITY) &&                                  \
-    __has_feature(attribute_availability_with_strict) &&                       \
-    __has_feature(attribute_availability_in_templates)
-#  ifdef __APPLE__
-#    define _LIBCPP_USE_AVAILABILITY_APPLE
-#  endif
-#endif
-
-// Define availability macros.
-#if defined(_LIBCPP_USE_AVAILABILITY_APPLE)
-#  define _LIBCPP_AVAILABILITY_SHARED_MUTEX                                    \
-     __attribute__((availability(macosx,strict,introduced=10.12)))             \
-     __attribute__((availability(ios,strict,introduced=10.0)))                 \
-     __attribute__((availability(tvos,strict,introduced=10.0)))                \
-     __attribute__((availability(watchos,strict,introduced=3.0)))
-#  define _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS                             \
-     __attribute__((availability(macosx,strict,introduced=10.14)))             \
-     __attribute__((availability(ios,strict,introduced=12.0)))                 \
-     __attribute__((availability(tvos,strict,introduced=12.0)))                \
-     __attribute__((availability(watchos,strict,introduced=5.0)))
-#  define _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS                              \
-     _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
-#  define _LIBCPP_AVAILABILITY_BAD_ANY_CAST                                    \
-     _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
-#  define _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS                             \
-     __attribute__((availability(macosx,strict,introduced=10.12)))             \
-     __attribute__((availability(ios,strict,introduced=10.0)))                 \
-     __attribute__((availability(tvos,strict,introduced=10.0)))                \
-     __attribute__((availability(watchos,strict,introduced=3.0)))
-#  define _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE                                \
-     __attribute__((availability(macosx,strict,introduced=10.12)))             \
-     __attribute__((availability(ios,strict,introduced=10.0)))                 \
-     __attribute__((availability(tvos,strict,introduced=10.0)))                \
-     __attribute__((availability(watchos,strict,introduced=3.0)))
-#  define _LIBCPP_AVAILABILITY_FUTURE_ERROR                                    \
-     __attribute__((availability(ios,strict,introduced=6.0)))
-#  define _LIBCPP_AVAILABILITY_TYPEINFO_VTABLE                                 \
-     __attribute__((availability(macosx,strict,introduced=10.9)))              \
-     __attribute__((availability(ios,strict,introduced=7.0)))
-#  define _LIBCPP_AVAILABILITY_LOCALE_CATEGORY                                 \
-     __attribute__((availability(macosx,strict,introduced=10.9)))              \
-     __attribute__((availability(ios,strict,introduced=7.0)))
-#  define _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR                               \
-     __attribute__((availability(macosx,strict,introduced=10.9)))              \
-     __attribute__((availability(ios,strict,introduced=7.0)))
-#else
-#  define _LIBCPP_AVAILABILITY_SHARED_MUTEX
-#  define _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS
-#  define _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
-#  define _LIBCPP_AVAILABILITY_BAD_ANY_CAST
-#  define _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS
-#  define _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE
-#  define _LIBCPP_AVAILABILITY_FUTURE_ERROR
-#  define _LIBCPP_AVAILABILITY_TYPEINFO_VTABLE
-#  define _LIBCPP_AVAILABILITY_LOCALE_CATEGORY
-#  define _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-#endif
-
-// Define availability that depends on _LIBCPP_NO_EXCEPTIONS.
-#ifdef _LIBCPP_NO_EXCEPTIONS
-#  define _LIBCPP_AVAILABILITY_FUTURE
-#  define _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
-#  define _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
-#  define _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-#else
-#  define _LIBCPP_AVAILABILITY_FUTURE                    _LIBCPP_AVAILABILITY_FUTURE_ERROR
-#  define _LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST        _LIBCPP_AVAILABILITY_BAD_ANY_CAST
-#  define _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS
-#  define _LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS  _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS
-#endif
-
-// The stream API was dropped and re-added in the dylib shipped on macOS
-// and iOS. We can only assume the dylib to provide these definitions for
-// macosx >= 10.9 and ios >= 7.0. Otherwise, the definitions are available
-// from the headers, but not from the dylib. Explicit instantiation
-// declarations for streams exist conditionally to this; if we provide
-// an explicit instantiation declaration and we try to deploy to a dylib
-// that does not provide those symbols, we'll get a load-time error.
-#if !defined(_LIBCPP_BUILDING_LIBRARY) &&                                      \
-    ((defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) &&                \
-      __ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__ < 1090) ||                 \
-     (defined(__ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__) &&               \
-      __ENVIRONMENT_IPHONE_OS_VERSION_MIN_REQUIRED__ < 70000))
-#  define _LIBCPP_DO_NOT_ASSUME_STREAMS_EXPLICIT_INSTANTIATION_IN_DYLIB
-#endif
-
-#if defined(_LIBCPP_COMPILER_IBM)
-#define _LIBCPP_HAS_NO_PRAGMA_PUSH_POP_MACRO
-#endif
-
-#if defined(_LIBCPP_HAS_NO_PRAGMA_PUSH_POP_MACRO)
-#  define _LIBCPP_PUSH_MACROS
-#  define _LIBCPP_POP_MACROS
-#else
-  // Don't warn about macro conflicts when we can restore them at the
-  // end of the header.
-#  ifndef _LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS
-#    define _LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS
-#  endif
-#  if defined(_LIBCPP_COMPILER_MSVC)
-#    define _LIBCPP_PUSH_MACROS    \
-       __pragma(push_macro("min")) \
-       __pragma(push_macro("max"))
-#    define _LIBCPP_POP_MACROS     \
-       __pragma(pop_macro("min"))  \
-       __pragma(pop_macro("max"))
-#  else
-#    define _LIBCPP_PUSH_MACROS        \
-       _Pragma("push_macro(\"min\")")  \
-       _Pragma("push_macro(\"max\")")
-#    define _LIBCPP_POP_MACROS         \
-       _Pragma("pop_macro(\"min\")")   \
-       _Pragma("pop_macro(\"max\")")
-#  endif
-#endif // defined(_LIBCPP_HAS_NO_PRAGMA_PUSH_POP_MACRO)
-
-#ifndef _LIBCPP_NO_AUTO_LINK
-#  if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
-#    if defined(_DLL)
-#      pragma comment(lib, "c++.lib")
-#    else
-#      pragma comment(lib, "libc++.lib")
-#    endif
-#  endif // defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_BUILDING_LIBRARY)
-#endif // _LIBCPP_NO_AUTO_LINK
-
-#define _LIBCPP_UNUSED_VAR(x) ((void)(x))
-
-#endif // __cplusplus
-
-#endif // _LIBCPP_CONFIG
diff --git a/lib/libcxx/include/__config_site.in b/lib/libcxx/include/__config_site.in
deleted file mode 100644
index 580a6aa4c07..00000000000
--- a/lib/libcxx/include/__config_site.in
+++ /dev/null
@@ -1,35 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CONFIG_SITE
-#define _LIBCPP_CONFIG_SITE
-
-#cmakedefine _LIBCPP_ABI_VERSION @_LIBCPP_ABI_VERSION@
-#cmakedefine _LIBCPP_ABI_UNSTABLE
-#cmakedefine _LIBCPP_ABI_FORCE_ITANIUM
-#cmakedefine _LIBCPP_ABI_FORCE_MICROSOFT
-#cmakedefine _LIBCPP_HIDE_FROM_ABI_PER_TU_BY_DEFAULT
-#cmakedefine _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-#cmakedefine _LIBCPP_HAS_NO_STDIN
-#cmakedefine _LIBCPP_HAS_NO_STDOUT
-#cmakedefine _LIBCPP_HAS_NO_THREADS
-#cmakedefine _LIBCPP_HAS_NO_MONOTONIC_CLOCK
-#cmakedefine _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
-#cmakedefine _LIBCPP_HAS_MUSL_LIBC
-#cmakedefine _LIBCPP_HAS_THREAD_API_PTHREAD
-#cmakedefine _LIBCPP_HAS_THREAD_API_EXTERNAL
-#cmakedefine _LIBCPP_HAS_THREAD_API_WIN32
-#cmakedefine _LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL
-#cmakedefine _LIBCPP_DISABLE_VISIBILITY_ANNOTATIONS
-#cmakedefine _LIBCPP_NO_VCRUNTIME
-#cmakedefine _LIBCPP_ABI_NAMESPACE @_LIBCPP_ABI_NAMESPACE@
-
-@_LIBCPP_ABI_DEFINES@
-
-#endif // _LIBCPP_CONFIG_SITE
diff --git a/lib/libcxx/include/__debug b/lib/libcxx/include/__debug
deleted file mode 100644
index a8788f68f8f..00000000000
--- a/lib/libcxx/include/__debug
+++ /dev/null
@@ -1,302 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- __debug ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_DEBUG_H
-#define _LIBCPP_DEBUG_H
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#if defined(_LIBCPP_HAS_NO_NULLPTR)
-# include <cstddef>
-#endif
-
-#if _LIBCPP_DEBUG_LEVEL >= 1 || defined(_LIBCPP_BUILDING_LIBRARY)
-#   include <cstdlib>
-#   include <cstdio>
-#   include <cstddef>
-#   include <exception>
-#endif
-
-#if _LIBCPP_DEBUG_LEVEL >= 1 && !defined(_LIBCPP_ASSERT)
-# define _LIBCPP_ASSERT(x, m) ((x) ? (void)0 : \
-  _VSTD::__libcpp_debug_function(_VSTD::__libcpp_debug_info(__FILE__, __LINE__, #x, m)))
-#endif
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-#ifndef _LIBCPP_DEBUG_ASSERT
-#define _LIBCPP_DEBUG_ASSERT(x, m) _LIBCPP_ASSERT(x, m)
-#endif
-#define _LIBCPP_DEBUG_MODE(...) __VA_ARGS__
-#endif
-
-#ifndef _LIBCPP_ASSERT
-#   define _LIBCPP_ASSERT(x, m) ((void)0)
-#endif
-#ifndef _LIBCPP_DEBUG_ASSERT
-#   define _LIBCPP_DEBUG_ASSERT(x, m) ((void)0)
-#endif
-#ifndef _LIBCPP_DEBUG_MODE
-#define _LIBCPP_DEBUG_MODE(...) ((void)0)
-#endif
-
-#if _LIBCPP_DEBUG_LEVEL < 1
-class _LIBCPP_EXCEPTION_ABI __libcpp_debug_exception;
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-struct _LIBCPP_TEMPLATE_VIS __libcpp_debug_info {
-  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-  __libcpp_debug_info()
-      : __file_(nullptr), __line_(-1), __pred_(nullptr), __msg_(nullptr) {}
-  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-  __libcpp_debug_info(const char* __f, int __l, const char* __p, const char* __m)
-    : __file_(__f), __line_(__l), __pred_(__p), __msg_(__m) {}
-  const char* __file_;
-  int __line_;
-  const char* __pred_;
-  const char* __msg_;
-};
-
-/// __libcpp_debug_function_type - The type of the assertion failure handler.
-typedef void(*__libcpp_debug_function_type)(__libcpp_debug_info const&);
-
-/// __libcpp_debug_function - The handler function called when a _LIBCPP_ASSERT
-///    fails.
-extern _LIBCPP_EXPORTED_FROM_ABI __libcpp_debug_function_type __libcpp_debug_function;
-
-/// __libcpp_abort_debug_function - A debug handler that aborts when called.
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS
-void __libcpp_abort_debug_function(__libcpp_debug_info const&);
-
-/// __libcpp_throw_debug_function - A debug handler that throws
-///   an instance of __libcpp_debug_exception when called.
- _LIBCPP_NORETURN _LIBCPP_FUNC_VIS
-void __libcpp_throw_debug_function(__libcpp_debug_info const&);
-
-/// __libcpp_set_debug_function - Set the debug handler to the specified
-///    function.
-_LIBCPP_FUNC_VIS
-bool __libcpp_set_debug_function(__libcpp_debug_function_type __func);
-
-// Setup the throwing debug handler during dynamic initialization.
-#if _LIBCPP_DEBUG_LEVEL >= 1 && defined(_LIBCPP_DEBUG_USE_EXCEPTIONS)
-# if defined(_LIBCPP_NO_EXCEPTIONS)
-#   error _LIBCPP_DEBUG_USE_EXCEPTIONS cannot be used when exceptions are disabled.
-# endif
-static bool __init_dummy = __libcpp_set_debug_function(__libcpp_throw_debug_function);
-#endif
-
-#if _LIBCPP_DEBUG_LEVEL >= 1 || defined(_LIBCPP_BUILDING_LIBRARY)
-class _LIBCPP_EXCEPTION_ABI __libcpp_debug_exception : public exception {
-public:
-  __libcpp_debug_exception() _NOEXCEPT;
-  explicit __libcpp_debug_exception(__libcpp_debug_info const& __i);
-  __libcpp_debug_exception(__libcpp_debug_exception const&);
-  ~__libcpp_debug_exception() _NOEXCEPT;
-  const char* what() const _NOEXCEPT;
-private:
-  struct __libcpp_debug_exception_imp;
-  __libcpp_debug_exception_imp *__imp_;
-};
-#endif
-
-#if _LIBCPP_DEBUG_LEVEL >= 2 || defined(_LIBCPP_BUILDING_LIBRARY)
-
-struct _LIBCPP_TYPE_VIS __c_node;
-
-struct _LIBCPP_TYPE_VIS __i_node
-{
-    void* __i_;
-    __i_node* __next_;
-    __c_node* __c_;
-
-#ifndef _LIBCPP_CXX03_LANG
-    __i_node(const __i_node&) = delete;
-    __i_node& operator=(const __i_node&) = delete;
-#else
-private:
-    __i_node(const __i_node&);
-    __i_node& operator=(const __i_node&);
-public:
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    __i_node(void* __i, __i_node* __next, __c_node* __c)
-        : __i_(__i), __next_(__next), __c_(__c) {}
-    ~__i_node();
-};
-
-struct _LIBCPP_TYPE_VIS __c_node
-{
-    void* __c_;
-    __c_node* __next_;
-    __i_node** beg_;
-    __i_node** end_;
-    __i_node** cap_;
-
-#ifndef _LIBCPP_CXX03_LANG
-    __c_node(const __c_node&) = delete;
-    __c_node& operator=(const __c_node&) = delete;
-#else
-private:
-    __c_node(const __c_node&);
-    __c_node& operator=(const __c_node&);
-public:
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    __c_node(void* __c, __c_node* __next)
-        : __c_(__c), __next_(__next), beg_(nullptr), end_(nullptr), cap_(nullptr) {}
-    virtual ~__c_node();
-
-    virtual bool __dereferenceable(const void*) const = 0;
-    virtual bool __decrementable(const void*) const = 0;
-    virtual bool __addable(const void*, ptrdiff_t) const = 0;
-    virtual bool __subscriptable(const void*, ptrdiff_t) const = 0;
-
-    void __add(__i_node* __i);
-    _LIBCPP_HIDDEN void __remove(__i_node* __i);
-};
-
-template <class _Cont>
-struct _C_node
-    : public __c_node
-{
-    _C_node(void* __c, __c_node* __n)
-        : __c_node(__c, __n) {}
-
-    virtual bool __dereferenceable(const void*) const;
-    virtual bool __decrementable(const void*) const;
-    virtual bool __addable(const void*, ptrdiff_t) const;
-    virtual bool __subscriptable(const void*, ptrdiff_t) const;
-};
-
-template <class _Cont>
-inline bool
-_C_node<_Cont>::__dereferenceable(const void* __i) const
-{
-    typedef typename _Cont::const_iterator iterator;
-    const iterator* __j = static_cast<const iterator*>(__i);
-    _Cont* _Cp = static_cast<_Cont*>(__c_);
-    return _Cp->__dereferenceable(__j);
-}
-
-template <class _Cont>
-inline bool
-_C_node<_Cont>::__decrementable(const void* __i) const
-{
-    typedef typename _Cont::const_iterator iterator;
-    const iterator* __j = static_cast<const iterator*>(__i);
-    _Cont* _Cp = static_cast<_Cont*>(__c_);
-    return _Cp->__decrementable(__j);
-}
-
-template <class _Cont>
-inline bool
-_C_node<_Cont>::__addable(const void* __i, ptrdiff_t __n) const
-{
-    typedef typename _Cont::const_iterator iterator;
-    const iterator* __j = static_cast<const iterator*>(__i);
-    _Cont* _Cp = static_cast<_Cont*>(__c_);
-    return _Cp->__addable(__j, __n);
-}
-
-template <class _Cont>
-inline bool
-_C_node<_Cont>::__subscriptable(const void* __i, ptrdiff_t __n) const
-{
-    typedef typename _Cont::const_iterator iterator;
-    const iterator* __j = static_cast<const iterator*>(__i);
-    _Cont* _Cp = static_cast<_Cont*>(__c_);
-    return _Cp->__subscriptable(__j, __n);
-}
-
-class _LIBCPP_TYPE_VIS __libcpp_db
-{
-    __c_node** __cbeg_;
-    __c_node** __cend_;
-    size_t   __csz_;
-    __i_node** __ibeg_;
-    __i_node** __iend_;
-    size_t   __isz_;
-
-    __libcpp_db();
-public:
-#ifndef _LIBCPP_CXX03_LANG
-    __libcpp_db(const __libcpp_db&) = delete;
-    __libcpp_db& operator=(const __libcpp_db&) = delete;
-#else
-private:
-    __libcpp_db(const __libcpp_db&);
-    __libcpp_db& operator=(const __libcpp_db&);
-public:
-#endif
-    ~__libcpp_db();
-
-    class __db_c_iterator;
-    class __db_c_const_iterator;
-    class __db_i_iterator;
-    class __db_i_const_iterator;
-
-    __db_c_const_iterator __c_end() const;
-    __db_i_const_iterator __i_end() const;
-
-    template <class _Cont>
-    _LIBCPP_INLINE_VISIBILITY
-    void __insert_c(_Cont* __c)
-    {
-        __c_node* __n = __insert_c(static_cast<void*>(__c));
-        ::new(__n) _C_node<_Cont>(__n->__c_, __n->__next_);
-    }
-
-    void __insert_i(void* __i);
-    __c_node* __insert_c(void* __c);
-    void __erase_c(void* __c);
-
-    void __insert_ic(void* __i, const void* __c);
-    void __iterator_copy(void* __i, const void* __i0);
-    void __erase_i(void* __i);
-
-    void* __find_c_from_i(void* __i) const;
-    void __invalidate_all(void* __c);
-    __c_node* __find_c_and_lock(void* __c) const;
-    __c_node* __find_c(void* __c) const;
-    void unlock() const;
-
-    void swap(void* __c1, void* __c2);
-
-
-    bool __dereferenceable(const void* __i) const;
-    bool __decrementable(const void* __i) const;
-    bool __addable(const void* __i, ptrdiff_t __n) const;
-    bool __subscriptable(const void* __i, ptrdiff_t __n) const;
-    bool __less_than_comparable(const void* __i, const void* __j) const;
-private:
-    _LIBCPP_HIDDEN
-    __i_node* __insert_iterator(void* __i);
-    _LIBCPP_HIDDEN
-    __i_node* __find_iterator(const void* __i) const;
-
-    friend _LIBCPP_FUNC_VIS __libcpp_db* __get_db();
-};
-
-_LIBCPP_FUNC_VIS __libcpp_db* __get_db();
-_LIBCPP_FUNC_VIS const __libcpp_db* __get_const_db();
-
-
-#endif // _LIBCPP_DEBUG_LEVEL >= 2 || defined(_LIBCPP_BUILDING_LIBRARY)
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_DEBUG_H
-
diff --git a/lib/libcxx/include/__errc b/lib/libcxx/include/__errc
deleted file mode 100644
index d0f00b7f0be..00000000000
--- a/lib/libcxx/include/__errc
+++ /dev/null
@@ -1,218 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- __errc ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___ERRC
-#define _LIBCPP___ERRC
-
-/*
-    system_error synopsis
-
-namespace std
-{
-
-enum class errc
-{
-    address_family_not_supported,       // EAFNOSUPPORT
-    address_in_use,                     // EADDRINUSE
-    address_not_available,              // EADDRNOTAVAIL
-    already_connected,                  // EISCONN
-    argument_list_too_long,             // E2BIG
-    argument_out_of_domain,             // EDOM
-    bad_address,                        // EFAULT
-    bad_file_descriptor,                // EBADF
-    bad_message,                        // EBADMSG
-    broken_pipe,                        // EPIPE
-    connection_aborted,                 // ECONNABORTED
-    connection_already_in_progress,     // EALREADY
-    connection_refused,                 // ECONNREFUSED
-    connection_reset,                   // ECONNRESET
-    cross_device_link,                  // EXDEV
-    destination_address_required,       // EDESTADDRREQ
-    device_or_resource_busy,            // EBUSY
-    directory_not_empty,                // ENOTEMPTY
-    executable_format_error,            // ENOEXEC
-    file_exists,                        // EEXIST
-    file_too_large,                     // EFBIG
-    filename_too_long,                  // ENAMETOOLONG
-    function_not_supported,             // ENOSYS
-    host_unreachable,                   // EHOSTUNREACH
-    identifier_removed,                 // EIDRM
-    illegal_byte_sequence,              // EILSEQ
-    inappropriate_io_control_operation, // ENOTTY
-    interrupted,                        // EINTR
-    invalid_argument,                   // EINVAL
-    invalid_seek,                       // ESPIPE
-    io_error,                           // EIO
-    is_a_directory,                     // EISDIR
-    message_size,                       // EMSGSIZE
-    network_down,                       // ENETDOWN
-    network_reset,                      // ENETRESET
-    network_unreachable,                // ENETUNREACH
-    no_buffer_space,                    // ENOBUFS
-    no_child_process,                   // ECHILD
-    no_link,                            // ENOLINK
-    no_lock_available,                  // ENOLCK
-    no_message_available,               // ENODATA
-    no_message,                         // ENOMSG
-    no_protocol_option,                 // ENOPROTOOPT
-    no_space_on_device,                 // ENOSPC
-    no_stream_resources,                // ENOSR
-    no_such_device_or_address,          // ENXIO
-    no_such_device,                     // ENODEV
-    no_such_file_or_directory,          // ENOENT
-    no_such_process,                    // ESRCH
-    not_a_directory,                    // ENOTDIR
-    not_a_socket,                       // ENOTSOCK
-    not_a_stream,                       // ENOSTR
-    not_connected,                      // ENOTCONN
-    not_enough_memory,                  // ENOMEM
-    not_supported,                      // ENOTSUP
-    operation_canceled,                 // ECANCELED
-    operation_in_progress,              // EINPROGRESS
-    operation_not_permitted,            // EPERM
-    operation_not_supported,            // EOPNOTSUPP
-    operation_would_block,              // EWOULDBLOCK
-    owner_dead,                         // EOWNERDEAD
-    permission_denied,                  // EACCES
-    protocol_error,                     // EPROTO
-    protocol_not_supported,             // EPROTONOSUPPORT
-    read_only_file_system,              // EROFS
-    resource_deadlock_would_occur,      // EDEADLK
-    resource_unavailable_try_again,     // EAGAIN
-    result_out_of_range,                // ERANGE
-    state_not_recoverable,              // ENOTRECOVERABLE
-    stream_timeout,                     // ETIME
-    text_file_busy,                     // ETXTBSY
-    timed_out,                          // ETIMEDOUT
-    too_many_files_open_in_system,      // ENFILE
-    too_many_files_open,                // EMFILE
-    too_many_links,                     // EMLINK
-    too_many_symbolic_link_levels,      // ELOOP
-    value_too_large,                    // EOVERFLOW
-    wrong_protocol_type                 // EPROTOTYPE
-};
-
-*/
-
-#include <__config>
-#include <cerrno>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// Some error codes are not present on all platforms, so we provide equivalents
-// for them:
-
-//enum class errc
-_LIBCPP_DECLARE_STRONG_ENUM(errc)
-{
-    address_family_not_supported        = EAFNOSUPPORT,
-    address_in_use                      = EADDRINUSE,
-    address_not_available               = EADDRNOTAVAIL,
-    already_connected                   = EISCONN,
-    argument_list_too_long              = E2BIG,
-    argument_out_of_domain              = EDOM,
-    bad_address                         = EFAULT,
-    bad_file_descriptor                 = EBADF,
-    bad_message                         = EBADMSG,
-    broken_pipe                         = EPIPE,
-    connection_aborted                  = ECONNABORTED,
-    connection_already_in_progress      = EALREADY,
-    connection_refused                  = ECONNREFUSED,
-    connection_reset                    = ECONNRESET,
-    cross_device_link                   = EXDEV,
-    destination_address_required        = EDESTADDRREQ,
-    device_or_resource_busy             = EBUSY,
-    directory_not_empty                 = ENOTEMPTY,
-    executable_format_error             = ENOEXEC,
-    file_exists                         = EEXIST,
-    file_too_large                      = EFBIG,
-    filename_too_long                   = ENAMETOOLONG,
-    function_not_supported              = ENOSYS,
-    host_unreachable                    = EHOSTUNREACH,
-    identifier_removed                  = EIDRM,
-    illegal_byte_sequence               = EILSEQ,
-    inappropriate_io_control_operation  = ENOTTY,
-    interrupted                         = EINTR,
-    invalid_argument                    = EINVAL,
-    invalid_seek                        = ESPIPE,
-    io_error                            = EIO,
-    is_a_directory                      = EISDIR,
-    message_size                        = EMSGSIZE,
-    network_down                        = ENETDOWN,
-    network_reset                       = ENETRESET,
-    network_unreachable                 = ENETUNREACH,
-    no_buffer_space                     = ENOBUFS,
-    no_child_process                    = ECHILD,
-    no_link                             = ENOLINK,
-    no_lock_available                   = ENOLCK,
-#ifdef ENODATA
-    no_message_available                = ENODATA,
-#else
-    no_message_available                = ENOMSG,
-#endif
-    no_message                          = ENOMSG,
-    no_protocol_option                  = ENOPROTOOPT,
-    no_space_on_device                  = ENOSPC,
-#ifdef ENOSR
-    no_stream_resources                 = ENOSR,
-#else
-    no_stream_resources                 = ENOMEM,
-#endif
-    no_such_device_or_address           = ENXIO,
-    no_such_device                      = ENODEV,
-    no_such_file_or_directory           = ENOENT,
-    no_such_process                     = ESRCH,
-    not_a_directory                     = ENOTDIR,
-    not_a_socket                        = ENOTSOCK,
-#ifdef ENOSTR
-    not_a_stream                        = ENOSTR,
-#else
-    not_a_stream                        = EINVAL,
-#endif
-    not_connected                       = ENOTCONN,
-    not_enough_memory                   = ENOMEM,
-    not_supported                       = ENOTSUP,
-    operation_canceled                  = ECANCELED,
-    operation_in_progress               = EINPROGRESS,
-    operation_not_permitted             = EPERM,
-    operation_not_supported             = EOPNOTSUPP,
-    operation_would_block               = EWOULDBLOCK,
-    owner_dead                          = EOWNERDEAD,
-    permission_denied                   = EACCES,
-    protocol_error                      = EPROTO,
-    protocol_not_supported              = EPROTONOSUPPORT,
-    read_only_file_system               = EROFS,
-    resource_deadlock_would_occur       = EDEADLK,
-    resource_unavailable_try_again      = EAGAIN,
-    result_out_of_range                 = ERANGE,
-    state_not_recoverable               = ENOTRECOVERABLE,
-#ifdef ETIME
-    stream_timeout                      = ETIME,
-#else
-    stream_timeout                      = ETIMEDOUT,
-#endif
-    text_file_busy                      = ETXTBSY,
-    timed_out                           = ETIMEDOUT,
-    too_many_files_open_in_system       = ENFILE,
-    too_many_files_open                 = EMFILE,
-    too_many_links                      = EMLINK,
-    too_many_symbolic_link_levels       = ELOOP,
-    value_too_large                     = EOVERFLOW,
-    wrong_protocol_type                 = EPROTOTYPE
-};
-_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(errc)
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP___ERRC
diff --git a/lib/libcxx/include/__functional_03 b/lib/libcxx/include/__functional_03
deleted file mode 100644
index 0a3bfbaa3d2..00000000000
--- a/lib/libcxx/include/__functional_03
+++ /dev/null
@@ -1,1592 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_FUNCTIONAL_03
-#define _LIBCPP_FUNCTIONAL_03
-
-// manual variadic expansion for <functional>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-namespace __function {
-
-template<class _Fp> class __base;
-
-template<class _Rp>
-class __base<_Rp()>
-{
-    __base(const __base&);
-    __base& operator=(const __base&);
-public:
-    __base() {}
-    virtual ~__base() {}
-    virtual __base* __clone() const = 0;
-    virtual void __clone(__base*) const = 0;
-    virtual void destroy() = 0;
-    virtual void destroy_deallocate() = 0;
-    virtual _Rp operator()() = 0;
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const = 0;
-    virtual const std::type_info& target_type() const = 0;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Rp, class _A0>
-class __base<_Rp(_A0)>
-{
-    __base(const __base&);
-    __base& operator=(const __base&);
-public:
-    __base() {}
-    virtual ~__base() {}
-    virtual __base* __clone() const = 0;
-    virtual void __clone(__base*) const = 0;
-    virtual void destroy() = 0;
-    virtual void destroy_deallocate() = 0;
-    virtual _Rp operator()(_A0) = 0;
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const = 0;
-    virtual const std::type_info& target_type() const = 0;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Rp, class _A0, class _A1>
-class __base<_Rp(_A0, _A1)>
-{
-    __base(const __base&);
-    __base& operator=(const __base&);
-public:
-    __base() {}
-    virtual ~__base() {}
-    virtual __base* __clone() const = 0;
-    virtual void __clone(__base*) const = 0;
-    virtual void destroy() = 0;
-    virtual void destroy_deallocate() = 0;
-    virtual _Rp operator()(_A0, _A1) = 0;
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const = 0;
-    virtual const std::type_info& target_type() const = 0;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Rp, class _A0, class _A1, class _A2>
-class __base<_Rp(_A0, _A1, _A2)>
-{
-    __base(const __base&);
-    __base& operator=(const __base&);
-public:
-    __base() {}
-    virtual ~__base() {}
-    virtual __base* __clone() const = 0;
-    virtual void __clone(__base*) const = 0;
-    virtual void destroy() = 0;
-    virtual void destroy_deallocate() = 0;
-    virtual _Rp operator()(_A0, _A1, _A2) = 0;
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const = 0;
-    virtual const std::type_info& target_type() const = 0;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _FD, class _Alloc, class _FB> class __func;
-
-template<class _Fp, class _Alloc, class _Rp>
-class __func<_Fp, _Alloc, _Rp()>
-    : public  __base<_Rp()>
-{
-    __compressed_pair<_Fp, _Alloc> __f_;
-public:
-    explicit __func(_Fp __f) : __f_(_VSTD::move(__f)) {}
-    explicit __func(_Fp __f, _Alloc __a) : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
-    virtual __base<_Rp()>* __clone() const;
-    virtual void __clone(__base<_Rp()>*) const;
-    virtual void destroy();
-    virtual void destroy_deallocate();
-    virtual _Rp operator()();
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const;
-    virtual const std::type_info& target_type() const;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Fp, class _Alloc, class _Rp>
-__base<_Rp()>*
-__func<_Fp, _Alloc, _Rp()>::__clone() const
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.second());
-    typedef __allocator_destructor<_Ap> _Dp;
-    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-    ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
-    return __hold.release();
-}
-
-template<class _Fp, class _Alloc, class _Rp>
-void
-__func<_Fp, _Alloc, _Rp()>::__clone(__base<_Rp()>* __p) const
-{
-    ::new (__p) __func(__f_.first(), __f_.second());
-}
-
-template<class _Fp, class _Alloc, class _Rp>
-void
-__func<_Fp, _Alloc, _Rp()>::destroy()
-{
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-}
-
-template<class _Fp, class _Alloc, class _Rp>
-void
-__func<_Fp, _Alloc, _Rp()>::destroy_deallocate()
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.second());
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-    __a.deallocate(this, 1);
-}
-
-template<class _Fp, class _Alloc, class _Rp>
-_Rp
-__func<_Fp, _Alloc, _Rp()>::operator()()
-{
-    typedef __invoke_void_return_wrapper<_Rp> _Invoker;
-    return _Invoker::__call(__f_.first());
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Fp, class _Alloc, class _Rp>
-const void*
-__func<_Fp, _Alloc, _Rp()>::target(const type_info& __ti) const
-{
-    if (__ti == typeid(_Fp))
-        return &__f_.first();
-    return (const void*)0;
-}
-
-template<class _Fp, class _Alloc, class _Rp>
-const std::type_info&
-__func<_Fp, _Alloc, _Rp()>::target_type() const
-{
-    return typeid(_Fp);
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template<class _Fp, class _Alloc, class _Rp, class _A0>
-class __func<_Fp, _Alloc, _Rp(_A0)>
-    : public  __base<_Rp(_A0)>
-{
-    __compressed_pair<_Fp, _Alloc> __f_;
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f) : __f_(_VSTD::move(__f)) {}
-    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f, _Alloc __a)
-        : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
-    virtual __base<_Rp(_A0)>* __clone() const;
-    virtual void __clone(__base<_Rp(_A0)>*) const;
-    virtual void destroy();
-    virtual void destroy_deallocate();
-    virtual _Rp operator()(_A0);
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const;
-    virtual const std::type_info& target_type() const;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Fp, class _Alloc, class _Rp, class _A0>
-__base<_Rp(_A0)>*
-__func<_Fp, _Alloc, _Rp(_A0)>::__clone() const
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.second());
-    typedef __allocator_destructor<_Ap> _Dp;
-    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-    ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
-    return __hold.release();
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0>
-void
-__func<_Fp, _Alloc, _Rp(_A0)>::__clone(__base<_Rp(_A0)>* __p) const
-{
-    ::new (__p) __func(__f_.first(), __f_.second());
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0>
-void
-__func<_Fp, _Alloc, _Rp(_A0)>::destroy()
-{
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0>
-void
-__func<_Fp, _Alloc, _Rp(_A0)>::destroy_deallocate()
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.second());
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-    __a.deallocate(this, 1);
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0>
-_Rp
-__func<_Fp, _Alloc, _Rp(_A0)>::operator()(_A0 __a0)
-{
-    typedef __invoke_void_return_wrapper<_Rp> _Invoker;
-    return _Invoker::__call(__f_.first(), __a0);
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Fp, class _Alloc, class _Rp, class _A0>
-const void*
-__func<_Fp, _Alloc, _Rp(_A0)>::target(const type_info& __ti) const
-{
-    if (__ti == typeid(_Fp))
-        return &__f_.first();
-    return (const void*)0;
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0>
-const std::type_info&
-__func<_Fp, _Alloc, _Rp(_A0)>::target_type() const
-{
-    return typeid(_Fp);
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
-class __func<_Fp, _Alloc, _Rp(_A0, _A1)>
-    : public  __base<_Rp(_A0, _A1)>
-{
-    __compressed_pair<_Fp, _Alloc> __f_;
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f) : __f_(_VSTD::move(__f)) {}
-    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f, _Alloc __a)
-        : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
-    virtual __base<_Rp(_A0, _A1)>* __clone() const;
-    virtual void __clone(__base<_Rp(_A0, _A1)>*) const;
-    virtual void destroy();
-    virtual void destroy_deallocate();
-    virtual _Rp operator()(_A0, _A1);
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const;
-    virtual const std::type_info& target_type() const;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
-__base<_Rp(_A0, _A1)>*
-__func<_Fp, _Alloc, _Rp(_A0, _A1)>::__clone() const
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.second());
-    typedef __allocator_destructor<_Ap> _Dp;
-    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-    ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
-    return __hold.release();
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
-void
-__func<_Fp, _Alloc, _Rp(_A0, _A1)>::__clone(__base<_Rp(_A0, _A1)>* __p) const
-{
-    ::new (__p) __func(__f_.first(), __f_.second());
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
-void
-__func<_Fp, _Alloc, _Rp(_A0, _A1)>::destroy()
-{
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
-void
-__func<_Fp, _Alloc, _Rp(_A0, _A1)>::destroy_deallocate()
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.second());
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-    __a.deallocate(this, 1);
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
-_Rp
-__func<_Fp, _Alloc, _Rp(_A0, _A1)>::operator()(_A0 __a0, _A1 __a1)
-{
-    typedef __invoke_void_return_wrapper<_Rp> _Invoker;
-    return _Invoker::__call(__f_.first(), __a0, __a1);
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
-const void*
-__func<_Fp, _Alloc, _Rp(_A0, _A1)>::target(const type_info& __ti) const
-{
-    if (__ti == typeid(_Fp))
-        return &__f_.first();
-    return (const void*)0;
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1>
-const std::type_info&
-__func<_Fp, _Alloc, _Rp(_A0, _A1)>::target_type() const
-{
-    return typeid(_Fp);
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
-class __func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>
-    : public  __base<_Rp(_A0, _A1, _A2)>
-{
-    __compressed_pair<_Fp, _Alloc> __f_;
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f) : __f_(_VSTD::move(__f)) {}
-    _LIBCPP_INLINE_VISIBILITY explicit __func(_Fp __f, _Alloc __a)
-        : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
-    virtual __base<_Rp(_A0, _A1, _A2)>* __clone() const;
-    virtual void __clone(__base<_Rp(_A0, _A1, _A2)>*) const;
-    virtual void destroy();
-    virtual void destroy_deallocate();
-    virtual _Rp operator()(_A0, _A1, _A2);
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const;
-    virtual const std::type_info& target_type() const;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
-__base<_Rp(_A0, _A1, _A2)>*
-__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::__clone() const
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.second());
-    typedef __allocator_destructor<_Ap> _Dp;
-    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-    ::new (__hold.get()) __func(__f_.first(), _Alloc(__a));
-    return __hold.release();
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
-void
-__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::__clone(__base<_Rp(_A0, _A1, _A2)>* __p) const
-{
-    ::new (__p) __func(__f_.first(), __f_.second());
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
-void
-__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::destroy()
-{
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
-void
-__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::destroy_deallocate()
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.second());
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-    __a.deallocate(this, 1);
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
-_Rp
-__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::operator()(_A0 __a0, _A1 __a1, _A2 __a2)
-{
-    typedef __invoke_void_return_wrapper<_Rp> _Invoker;
-    return _Invoker::__call(__f_.first(), __a0, __a1, __a2);
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
-const void*
-__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::target(const type_info& __ti) const
-{
-    if (__ti == typeid(_Fp))
-        return &__f_.first();
-    return (const void*)0;
-}
-
-template<class _Fp, class _Alloc, class _Rp, class _A0, class _A1, class _A2>
-const std::type_info&
-__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)>::target_type() const
-{
-    return typeid(_Fp);
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-}  // __function
-
-template<class _Rp>
-class _LIBCPP_TEMPLATE_VIS function<_Rp()>
-{
-    typedef __function::__base<_Rp()> __base;
-    aligned_storage<3*sizeof(void*)>::type __buf_;
-    __base* __f_;
-
-public:
-    typedef _Rp result_type;
-
-    // 20.7.16.2.1, construct/copy/destroy:
-    _LIBCPP_INLINE_VISIBILITY explicit function() : __f_(0) {}
-    _LIBCPP_INLINE_VISIBILITY function(nullptr_t) : __f_(0) {}
-    function(const function&);
-    template<class _Fp>
-      function(_Fp,
-               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
-
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&) : __f_(0) {}
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&, nullptr_t) : __f_(0) {}
-    template<class _Alloc>
-      function(allocator_arg_t, const _Alloc&, const function&);
-    template<class _Fp, class _Alloc>
-      function(allocator_arg_t, const _Alloc& __a, _Fp __f,
-               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
-
-    function& operator=(const function&);
-    function& operator=(nullptr_t);
-    template<class _Fp>
-      typename enable_if
-      <
-        !is_integral<_Fp>::value,
-        function&
-      >::type
-      operator=(_Fp);
-
-    ~function();
-
-    // 20.7.16.2.2, function modifiers:
-    void swap(function&);
-    template<class _Fp, class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      void assign(_Fp __f, const _Alloc& __a)
-        {function(allocator_arg, __a, __f).swap(*this);}
-
-    // 20.7.16.2.3, function capacity:
-    _LIBCPP_INLINE_VISIBILITY operator bool() const {return __f_;}
-
-private:
-    // deleted overloads close possible hole in the type system
-    template<class _R2>
-      bool operator==(const function<_R2()>&) const;// = delete;
-    template<class _R2>
-      bool operator!=(const function<_R2()>&) const;// = delete;
-public:
-    // 20.7.16.2.4, function invocation:
-    _Rp operator()() const;
-
-#ifndef _LIBCPP_NO_RTTI
-    // 20.7.16.2.5, function target access:
-    const std::type_info& target_type() const;
-    template <typename _Tp> _Tp* target();
-    template <typename _Tp> const _Tp* target() const;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Rp>
-function<_Rp()>::function(const function& __f)
-{
-    if (__f.__f_ == 0)
-        __f_ = 0;
-    else if (__f.__f_ == (const __base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__clone(__f_);
-    }
-    else
-        __f_ = __f.__f_->__clone();
-}
-
-template<class _Rp>
-template<class _Alloc>
-function<_Rp()>::function(allocator_arg_t, const _Alloc&, const function& __f)
-{
-    if (__f.__f_ == 0)
-        __f_ = 0;
-    else if (__f.__f_ == (const __base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__clone(__f_);
-    }
-    else
-        __f_ = __f.__f_->__clone();
-}
-
-template<class _Rp>
-template <class _Fp>
-function<_Rp()>::function(_Fp __f,
-                                     typename enable_if<!is_integral<_Fp>::value>::type*)
-    : __f_(0)
-{
-    if (__function::__not_null(__f))
-    {
-        typedef __function::__func<_Fp, allocator<_Fp>, _Rp()> _FF;
-        if (sizeof(_FF) <= sizeof(__buf_))
-        {
-            __f_ = (__base*)&__buf_;
-            ::new (__f_) _FF(__f);
-        }
-        else
-        {
-            typedef allocator<_FF> _Ap;
-            _Ap __a;
-            typedef __allocator_destructor<_Ap> _Dp;
-            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-            ::new (__hold.get()) _FF(__f, allocator<_Fp>(__a));
-            __f_ = __hold.release();
-        }
-    }
-}
-
-template<class _Rp>
-template <class _Fp, class _Alloc>
-function<_Rp()>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
-                                     typename enable_if<!is_integral<_Fp>::value>::type*)
-    : __f_(0)
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    if (__function::__not_null(__f))
-    {
-        typedef __function::__func<_Fp, _Alloc, _Rp()> _FF;
-        if (sizeof(_FF) <= sizeof(__buf_))
-        {
-            __f_ = (__base*)&__buf_;
-            ::new (__f_) _FF(__f, __a0);
-        }
-        else
-        {
-            typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
-            _Ap __a(__a0);
-            typedef __allocator_destructor<_Ap> _Dp;
-            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-            ::new (__hold.get()) _FF(__f, _Alloc(__a));
-            __f_ = __hold.release();
-        }
-    }
-}
-
-template<class _Rp>
-function<_Rp()>&
-function<_Rp()>::operator=(const function& __f)
-{
-    if (__f)
-        function(__f).swap(*this);
-    else
-        *this = nullptr;
-    return *this;
-}
-
-template<class _Rp>
-function<_Rp()>&
-function<_Rp()>::operator=(nullptr_t)
-{
-    __base* __t = __f_;
-    __f_ = 0;
-    if (__t == (__base*)&__buf_)
-        __t->destroy();
-    else if (__t)
-        __t->destroy_deallocate();
-    return *this;
-}
-
-template<class _Rp>
-template <class _Fp>
-typename enable_if
-<
-    !is_integral<_Fp>::value,
-    function<_Rp()>&
->::type
-function<_Rp()>::operator=(_Fp __f)
-{
-    function(_VSTD::move(__f)).swap(*this);
-    return *this;
-}
-
-template<class _Rp>
-function<_Rp()>::~function()
-{
-    if (__f_ == (__base*)&__buf_)
-        __f_->destroy();
-    else if (__f_)
-        __f_->destroy_deallocate();
-}
-
-template<class _Rp>
-void
-function<_Rp()>::swap(function& __f)
-{
-    if (_VSTD::addressof(__f) == this)
-      return;
-    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
-    {
-        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
-        __base* __t = (__base*)&__tempbuf;
-        __f_->__clone(__t);
-        __f_->destroy();
-        __f_ = 0;
-        __f.__f_->__clone((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = 0;
-        __f_ = (__base*)&__buf_;
-        __t->__clone((__base*)&__f.__buf_);
-        __t->destroy();
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f_ == (__base*)&__buf_)
-    {
-        __f_->__clone((__base*)&__f.__buf_);
-        __f_->destroy();
-        __f_ = __f.__f_;
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f.__f_ == (__base*)&__f.__buf_)
-    {
-        __f.__f_->__clone((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = __f_;
-        __f_ = (__base*)&__buf_;
-    }
-    else
-        _VSTD::swap(__f_, __f.__f_);
-}
-
-template<class _Rp>
-_Rp
-function<_Rp()>::operator()() const
-{
-    if (__f_ == 0)
-        __throw_bad_function_call();
-    return (*__f_)();
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Rp>
-const std::type_info&
-function<_Rp()>::target_type() const
-{
-    if (__f_ == 0)
-        return typeid(void);
-    return __f_->target_type();
-}
-
-template<class _Rp>
-template <typename _Tp>
-_Tp*
-function<_Rp()>::target()
-{
-    if (__f_ == 0)
-        return (_Tp*)0;
-    return (_Tp*) const_cast<void *>(__f_->target(typeid(_Tp)));
-}
-
-template<class _Rp>
-template <typename _Tp>
-const _Tp*
-function<_Rp()>::target() const
-{
-    if (__f_ == 0)
-        return (const _Tp*)0;
-    return (const _Tp*)__f_->target(typeid(_Tp));
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template<class _Rp, class _A0>
-class _LIBCPP_TEMPLATE_VIS function<_Rp(_A0)>
-    : public unary_function<_A0, _Rp>
-{
-    typedef __function::__base<_Rp(_A0)> __base;
-    aligned_storage<3*sizeof(void*)>::type __buf_;
-    __base* __f_;
-
-public:
-    typedef _Rp result_type;
-
-    // 20.7.16.2.1, construct/copy/destroy:
-    _LIBCPP_INLINE_VISIBILITY explicit function() : __f_(0) {}
-    _LIBCPP_INLINE_VISIBILITY function(nullptr_t) : __f_(0) {}
-    function(const function&);
-    template<class _Fp>
-      function(_Fp,
-               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
-
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&) : __f_(0) {}
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&, nullptr_t) : __f_(0) {}
-    template<class _Alloc>
-      function(allocator_arg_t, const _Alloc&, const function&);
-    template<class _Fp, class _Alloc>
-      function(allocator_arg_t, const _Alloc& __a, _Fp __f,
-               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
-
-    function& operator=(const function&);
-    function& operator=(nullptr_t);
-    template<class _Fp>
-      typename enable_if
-      <
-        !is_integral<_Fp>::value,
-        function&
-      >::type
-      operator=(_Fp);
-
-    ~function();
-
-    // 20.7.16.2.2, function modifiers:
-    void swap(function&);
-    template<class _Fp, class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      void assign(_Fp __f, const _Alloc& __a)
-        {function(allocator_arg, __a, __f).swap(*this);}
-
-    // 20.7.16.2.3, function capacity:
-    _LIBCPP_INLINE_VISIBILITY operator bool() const {return __f_;}
-
-private:
-    // deleted overloads close possible hole in the type system
-    template<class _R2, class _B0>
-      bool operator==(const function<_R2(_B0)>&) const;// = delete;
-    template<class _R2, class _B0>
-      bool operator!=(const function<_R2(_B0)>&) const;// = delete;
-public:
-    // 20.7.16.2.4, function invocation:
-    _Rp operator()(_A0) const;
-
-#ifndef _LIBCPP_NO_RTTI
-    // 20.7.16.2.5, function target access:
-    const std::type_info& target_type() const;
-    template <typename _Tp> _Tp* target();
-    template <typename _Tp> const _Tp* target() const;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Rp, class _A0>
-function<_Rp(_A0)>::function(const function& __f)
-{
-    if (__f.__f_ == 0)
-        __f_ = 0;
-    else if (__f.__f_ == (const __base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__clone(__f_);
-    }
-    else
-        __f_ = __f.__f_->__clone();
-}
-
-template<class _Rp, class _A0>
-template<class _Alloc>
-function<_Rp(_A0)>::function(allocator_arg_t, const _Alloc&, const function& __f)
-{
-    if (__f.__f_ == 0)
-        __f_ = 0;
-    else if (__f.__f_ == (const __base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__clone(__f_);
-    }
-    else
-        __f_ = __f.__f_->__clone();
-}
-
-template<class _Rp, class _A0>
-template <class _Fp>
-function<_Rp(_A0)>::function(_Fp __f,
-                                     typename enable_if<!is_integral<_Fp>::value>::type*)
-    : __f_(0)
-{
-    if (__function::__not_null(__f))
-    {
-        typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_A0)> _FF;
-        if (sizeof(_FF) <= sizeof(__buf_))
-        {
-            __f_ = (__base*)&__buf_;
-            ::new (__f_) _FF(__f);
-        }
-        else
-        {
-            typedef allocator<_FF> _Ap;
-            _Ap __a;
-            typedef __allocator_destructor<_Ap> _Dp;
-            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-            ::new (__hold.get()) _FF(__f, allocator<_Fp>(__a));
-            __f_ = __hold.release();
-        }
-    }
-}
-
-template<class _Rp, class _A0>
-template <class _Fp, class _Alloc>
-function<_Rp(_A0)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
-                                     typename enable_if<!is_integral<_Fp>::value>::type*)
-    : __f_(0)
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    if (__function::__not_null(__f))
-    {
-        typedef __function::__func<_Fp, _Alloc, _Rp(_A0)> _FF;
-        if (sizeof(_FF) <= sizeof(__buf_))
-        {
-            __f_ = (__base*)&__buf_;
-            ::new (__f_) _FF(__f, __a0);
-        }
-        else
-        {
-            typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
-            _Ap __a(__a0);
-            typedef __allocator_destructor<_Ap> _Dp;
-            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-            ::new (__hold.get()) _FF(__f, _Alloc(__a));
-            __f_ = __hold.release();
-        }
-    }
-}
-
-template<class _Rp, class _A0>
-function<_Rp(_A0)>&
-function<_Rp(_A0)>::operator=(const function& __f)
-{
-    if (__f)
-        function(__f).swap(*this);
-    else
-        *this = nullptr;
-    return *this;
-}
-
-template<class _Rp, class _A0>
-function<_Rp(_A0)>&
-function<_Rp(_A0)>::operator=(nullptr_t)
-{
-    __base* __t = __f_;
-    __f_ = 0;
-    if (__t == (__base*)&__buf_)
-        __t->destroy();
-    else if (__t)
-        __t->destroy_deallocate();
-    return *this;
-}
-
-template<class _Rp, class _A0>
-template <class _Fp>
-typename enable_if
-<
-    !is_integral<_Fp>::value,
-    function<_Rp(_A0)>&
->::type
-function<_Rp(_A0)>::operator=(_Fp __f)
-{
-    function(_VSTD::move(__f)).swap(*this);
-    return *this;
-}
-
-template<class _Rp, class _A0>
-function<_Rp(_A0)>::~function()
-{
-    if (__f_ == (__base*)&__buf_)
-        __f_->destroy();
-    else if (__f_)
-        __f_->destroy_deallocate();
-}
-
-template<class _Rp, class _A0>
-void
-function<_Rp(_A0)>::swap(function& __f)
-{
-    if (_VSTD::addressof(__f) == this)
-      return;
-    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
-    {
-        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
-        __base* __t = (__base*)&__tempbuf;
-        __f_->__clone(__t);
-        __f_->destroy();
-        __f_ = 0;
-        __f.__f_->__clone((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = 0;
-        __f_ = (__base*)&__buf_;
-        __t->__clone((__base*)&__f.__buf_);
-        __t->destroy();
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f_ == (__base*)&__buf_)
-    {
-        __f_->__clone((__base*)&__f.__buf_);
-        __f_->destroy();
-        __f_ = __f.__f_;
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f.__f_ == (__base*)&__f.__buf_)
-    {
-        __f.__f_->__clone((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = __f_;
-        __f_ = (__base*)&__buf_;
-    }
-    else
-        _VSTD::swap(__f_, __f.__f_);
-}
-
-template<class _Rp, class _A0>
-_Rp
-function<_Rp(_A0)>::operator()(_A0 __a0) const
-{
-    if (__f_ == 0)
-        __throw_bad_function_call();
-    return (*__f_)(__a0);
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Rp, class _A0>
-const std::type_info&
-function<_Rp(_A0)>::target_type() const
-{
-    if (__f_ == 0)
-        return typeid(void);
-    return __f_->target_type();
-}
-
-template<class _Rp, class _A0>
-template <typename _Tp>
-_Tp*
-function<_Rp(_A0)>::target()
-{
-    if (__f_ == 0)
-        return (_Tp*)0;
-    return (_Tp*) const_cast<void *>(__f_->target(typeid(_Tp)));
-}
-
-template<class _Rp, class _A0>
-template <typename _Tp>
-const _Tp*
-function<_Rp(_A0)>::target() const
-{
-    if (__f_ == 0)
-        return (const _Tp*)0;
-    return (const _Tp*)__f_->target(typeid(_Tp));
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template<class _Rp, class _A0, class _A1>
-class _LIBCPP_TEMPLATE_VIS function<_Rp(_A0, _A1)>
-    : public binary_function<_A0, _A1, _Rp>
-{
-    typedef __function::__base<_Rp(_A0, _A1)> __base;
-    aligned_storage<3*sizeof(void*)>::type __buf_;
-    __base* __f_;
-
-public:
-    typedef _Rp result_type;
-
-    // 20.7.16.2.1, construct/copy/destroy:
-    _LIBCPP_INLINE_VISIBILITY explicit function() : __f_(0) {}
-    _LIBCPP_INLINE_VISIBILITY function(nullptr_t) : __f_(0) {}
-    function(const function&);
-    template<class _Fp>
-      function(_Fp,
-               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
-
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&) : __f_(0) {}
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&, nullptr_t) : __f_(0) {}
-    template<class _Alloc>
-      function(allocator_arg_t, const _Alloc&, const function&);
-    template<class _Fp, class _Alloc>
-      function(allocator_arg_t, const _Alloc& __a, _Fp __f,
-               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
-
-    function& operator=(const function&);
-    function& operator=(nullptr_t);
-    template<class _Fp>
-      typename enable_if
-      <
-        !is_integral<_Fp>::value,
-        function&
-      >::type
-      operator=(_Fp);
-
-    ~function();
-
-    // 20.7.16.2.2, function modifiers:
-    void swap(function&);
-    template<class _Fp, class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      void assign(_Fp __f, const _Alloc& __a)
-        {function(allocator_arg, __a, __f).swap(*this);}
-
-    // 20.7.16.2.3, function capacity:
-    operator bool() const {return __f_;}
-
-private:
-    // deleted overloads close possible hole in the type system
-    template<class _R2, class _B0, class _B1>
-      bool operator==(const function<_R2(_B0, _B1)>&) const;// = delete;
-    template<class _R2, class _B0, class _B1>
-      bool operator!=(const function<_R2(_B0, _B1)>&) const;// = delete;
-public:
-    // 20.7.16.2.4, function invocation:
-    _Rp operator()(_A0, _A1) const;
-
-#ifndef _LIBCPP_NO_RTTI
-    // 20.7.16.2.5, function target access:
-    const std::type_info& target_type() const;
-    template <typename _Tp> _Tp* target();
-    template <typename _Tp> const _Tp* target() const;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Rp, class _A0, class _A1>
-function<_Rp(_A0, _A1)>::function(const function& __f)
-{
-    if (__f.__f_ == 0)
-        __f_ = 0;
-    else if (__f.__f_ == (const __base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__clone(__f_);
-    }
-    else
-        __f_ = __f.__f_->__clone();
-}
-
-template<class _Rp, class _A0, class _A1>
-template<class _Alloc>
-function<_Rp(_A0, _A1)>::function(allocator_arg_t, const _Alloc&, const function& __f)
-{
-    if (__f.__f_ == 0)
-        __f_ = 0;
-    else if (__f.__f_ == (const __base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__clone(__f_);
-    }
-    else
-        __f_ = __f.__f_->__clone();
-}
-
-template<class _Rp, class _A0, class _A1>
-template <class _Fp>
-function<_Rp(_A0, _A1)>::function(_Fp __f,
-                                 typename enable_if<!is_integral<_Fp>::value>::type*)
-    : __f_(0)
-{
-    if (__function::__not_null(__f))
-    {
-        typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_A0, _A1)> _FF;
-        if (sizeof(_FF) <= sizeof(__buf_))
-        {
-            __f_ = (__base*)&__buf_;
-            ::new (__f_) _FF(__f);
-        }
-        else
-        {
-            typedef allocator<_FF> _Ap;
-            _Ap __a;
-            typedef __allocator_destructor<_Ap> _Dp;
-            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-            ::new (__hold.get()) _FF(__f, allocator<_Fp>(__a));
-            __f_ = __hold.release();
-        }
-    }
-}
-
-template<class _Rp, class _A0, class _A1>
-template <class _Fp, class _Alloc>
-function<_Rp(_A0, _A1)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
-                                 typename enable_if<!is_integral<_Fp>::value>::type*)
-    : __f_(0)
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    if (__function::__not_null(__f))
-    {
-        typedef __function::__func<_Fp, _Alloc, _Rp(_A0, _A1)> _FF;
-        if (sizeof(_FF) <= sizeof(__buf_))
-        {
-            __f_ = (__base*)&__buf_;
-            ::new (__f_) _FF(__f, __a0);
-        }
-        else
-        {
-            typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
-            _Ap __a(__a0);
-            typedef __allocator_destructor<_Ap> _Dp;
-            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-            ::new (__hold.get()) _FF(__f, _Alloc(__a));
-            __f_ = __hold.release();
-        }
-    }
-}
-
-template<class _Rp, class _A0, class _A1>
-function<_Rp(_A0, _A1)>&
-function<_Rp(_A0, _A1)>::operator=(const function& __f)
-{
-    if (__f)
-        function(__f).swap(*this);
-    else
-        *this = nullptr;
-    return *this;
-}
-
-template<class _Rp, class _A0, class _A1>
-function<_Rp(_A0, _A1)>&
-function<_Rp(_A0, _A1)>::operator=(nullptr_t)
-{
-    __base* __t = __f_;
-    __f_ = 0;
-    if (__t == (__base*)&__buf_)
-        __t->destroy();
-    else if (__t)
-        __t->destroy_deallocate();
-    return *this;
-}
-
-template<class _Rp, class _A0, class _A1>
-template <class _Fp>
-typename enable_if
-<
-    !is_integral<_Fp>::value,
-    function<_Rp(_A0, _A1)>&
->::type
-function<_Rp(_A0, _A1)>::operator=(_Fp __f)
-{
-    function(_VSTD::move(__f)).swap(*this);
-    return *this;
-}
-
-template<class _Rp, class _A0, class _A1>
-function<_Rp(_A0, _A1)>::~function()
-{
-    if (__f_ == (__base*)&__buf_)
-        __f_->destroy();
-    else if (__f_)
-        __f_->destroy_deallocate();
-}
-
-template<class _Rp, class _A0, class _A1>
-void
-function<_Rp(_A0, _A1)>::swap(function& __f)
-{
-    if (_VSTD::addressof(__f) == this)
-      return;
-    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
-    {
-        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
-        __base* __t = (__base*)&__tempbuf;
-        __f_->__clone(__t);
-        __f_->destroy();
-        __f_ = 0;
-        __f.__f_->__clone((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = 0;
-        __f_ = (__base*)&__buf_;
-        __t->__clone((__base*)&__f.__buf_);
-        __t->destroy();
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f_ == (__base*)&__buf_)
-    {
-        __f_->__clone((__base*)&__f.__buf_);
-        __f_->destroy();
-        __f_ = __f.__f_;
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f.__f_ == (__base*)&__f.__buf_)
-    {
-        __f.__f_->__clone((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = __f_;
-        __f_ = (__base*)&__buf_;
-    }
-    else
-        _VSTD::swap(__f_, __f.__f_);
-}
-
-template<class _Rp, class _A0, class _A1>
-_Rp
-function<_Rp(_A0, _A1)>::operator()(_A0 __a0, _A1 __a1) const
-{
-    if (__f_ == 0)
-        __throw_bad_function_call();
-    return (*__f_)(__a0, __a1);
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Rp, class _A0, class _A1>
-const std::type_info&
-function<_Rp(_A0, _A1)>::target_type() const
-{
-    if (__f_ == 0)
-        return typeid(void);
-    return __f_->target_type();
-}
-
-template<class _Rp, class _A0, class _A1>
-template <typename _Tp>
-_Tp*
-function<_Rp(_A0, _A1)>::target()
-{
-    if (__f_ == 0)
-        return (_Tp*)0;
-    return (_Tp*) const_cast<void *>(__f_->target(typeid(_Tp)));
-}
-
-template<class _Rp, class _A0, class _A1>
-template <typename _Tp>
-const _Tp*
-function<_Rp(_A0, _A1)>::target() const
-{
-    if (__f_ == 0)
-        return (const _Tp*)0;
-    return (const _Tp*)__f_->target(typeid(_Tp));
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template<class _Rp, class _A0, class _A1, class _A2>
-class _LIBCPP_TEMPLATE_VIS function<_Rp(_A0, _A1, _A2)>
-{
-    typedef __function::__base<_Rp(_A0, _A1, _A2)> __base;
-    aligned_storage<3*sizeof(void*)>::type __buf_;
-    __base* __f_;
-
-public:
-    typedef _Rp result_type;
-
-    // 20.7.16.2.1, construct/copy/destroy:
-    _LIBCPP_INLINE_VISIBILITY explicit function() : __f_(0) {}
-    _LIBCPP_INLINE_VISIBILITY function(nullptr_t) : __f_(0) {}
-    function(const function&);
-    template<class _Fp>
-      function(_Fp,
-               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
-
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&) : __f_(0) {}
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&, nullptr_t) : __f_(0) {}
-    template<class _Alloc>
-      function(allocator_arg_t, const _Alloc&, const function&);
-    template<class _Fp, class _Alloc>
-      function(allocator_arg_t, const _Alloc& __a, _Fp __f,
-               typename enable_if<!is_integral<_Fp>::value>::type* = 0);
-
-    function& operator=(const function&);
-    function& operator=(nullptr_t);
-    template<class _Fp>
-      typename enable_if
-      <
-        !is_integral<_Fp>::value,
-        function&
-      >::type
-      operator=(_Fp);
-
-    ~function();
-
-    // 20.7.16.2.2, function modifiers:
-    void swap(function&);
-    template<class _Fp, class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      void assign(_Fp __f, const _Alloc& __a)
-        {function(allocator_arg, __a, __f).swap(*this);}
-
-    // 20.7.16.2.3, function capacity:
-    _LIBCPP_INLINE_VISIBILITY operator bool() const {return __f_;}
-
-private:
-    // deleted overloads close possible hole in the type system
-    template<class _R2, class _B0, class _B1, class _B2>
-      bool operator==(const function<_R2(_B0, _B1, _B2)>&) const;// = delete;
-    template<class _R2, class _B0, class _B1, class _B2>
-      bool operator!=(const function<_R2(_B0, _B1, _B2)>&) const;// = delete;
-public:
-    // 20.7.16.2.4, function invocation:
-    _Rp operator()(_A0, _A1, _A2) const;
-
-#ifndef _LIBCPP_NO_RTTI
-    // 20.7.16.2.5, function target access:
-    const std::type_info& target_type() const;
-    template <typename _Tp> _Tp* target();
-    template <typename _Tp> const _Tp* target() const;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Rp, class _A0, class _A1, class _A2>
-function<_Rp(_A0, _A1, _A2)>::function(const function& __f)
-{
-    if (__f.__f_ == 0)
-        __f_ = 0;
-    else if (__f.__f_ == (const __base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__clone(__f_);
-    }
-    else
-        __f_ = __f.__f_->__clone();
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-template<class _Alloc>
-function<_Rp(_A0, _A1, _A2)>::function(allocator_arg_t, const _Alloc&,
-                                      const function& __f)
-{
-    if (__f.__f_ == 0)
-        __f_ = 0;
-    else if (__f.__f_ == (const __base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__clone(__f_);
-    }
-    else
-        __f_ = __f.__f_->__clone();
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-template <class _Fp>
-function<_Rp(_A0, _A1, _A2)>::function(_Fp __f,
-                                     typename enable_if<!is_integral<_Fp>::value>::type*)
-    : __f_(0)
-{
-    if (__function::__not_null(__f))
-    {
-        typedef __function::__func<_Fp, allocator<_Fp>, _Rp(_A0, _A1, _A2)> _FF;
-        if (sizeof(_FF) <= sizeof(__buf_))
-        {
-            __f_ = (__base*)&__buf_;
-            ::new (__f_) _FF(__f);
-        }
-        else
-        {
-            typedef allocator<_FF> _Ap;
-            _Ap __a;
-            typedef __allocator_destructor<_Ap> _Dp;
-            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-            ::new (__hold.get()) _FF(__f, allocator<_Fp>(__a));
-            __f_ = __hold.release();
-        }
-    }
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-template <class _Fp, class _Alloc>
-function<_Rp(_A0, _A1, _A2)>::function(allocator_arg_t, const _Alloc& __a0, _Fp __f,
-                                     typename enable_if<!is_integral<_Fp>::value>::type*)
-    : __f_(0)
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    if (__function::__not_null(__f))
-    {
-        typedef __function::__func<_Fp, _Alloc, _Rp(_A0, _A1, _A2)> _FF;
-        if (sizeof(_FF) <= sizeof(__buf_))
-        {
-            __f_ = (__base*)&__buf_;
-            ::new (__f_) _FF(__f, __a0);
-        }
-        else
-        {
-            typedef typename __rebind_alloc_helper<__alloc_traits, _FF>::type _Ap;
-            _Ap __a(__a0);
-            typedef __allocator_destructor<_Ap> _Dp;
-            unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-            ::new (__hold.get()) _FF(__f, _Alloc(__a));
-            __f_ = __hold.release();
-        }
-    }
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-function<_Rp(_A0, _A1, _A2)>&
-function<_Rp(_A0, _A1, _A2)>::operator=(const function& __f)
-{
-    if (__f)
-        function(__f).swap(*this);
-    else
-        *this = nullptr;
-    return *this;
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-function<_Rp(_A0, _A1, _A2)>&
-function<_Rp(_A0, _A1, _A2)>::operator=(nullptr_t)
-{
-    __base* __t = __f_;
-    __f_ = 0;
-    if (__t == (__base*)&__buf_)
-        __t->destroy();
-    else if (__t)
-        __t->destroy_deallocate();
-    return *this;
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-template <class _Fp>
-typename enable_if
-<
-    !is_integral<_Fp>::value,
-    function<_Rp(_A0, _A1, _A2)>&
->::type
-function<_Rp(_A0, _A1, _A2)>::operator=(_Fp __f)
-{
-    function(_VSTD::move(__f)).swap(*this);
-    return *this;
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-function<_Rp(_A0, _A1, _A2)>::~function()
-{
-    if (__f_ == (__base*)&__buf_)
-        __f_->destroy();
-    else if (__f_)
-        __f_->destroy_deallocate();
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-void
-function<_Rp(_A0, _A1, _A2)>::swap(function& __f)
-{
-    if (_VSTD::addressof(__f) == this)
-      return;
-    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
-    {
-        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
-        __base* __t = (__base*)&__tempbuf;
-        __f_->__clone(__t);
-        __f_->destroy();
-        __f_ = 0;
-        __f.__f_->__clone((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = 0;
-        __f_ = (__base*)&__buf_;
-        __t->__clone((__base*)&__f.__buf_);
-        __t->destroy();
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f_ == (__base*)&__buf_)
-    {
-        __f_->__clone((__base*)&__f.__buf_);
-        __f_->destroy();
-        __f_ = __f.__f_;
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f.__f_ == (__base*)&__f.__buf_)
-    {
-        __f.__f_->__clone((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = __f_;
-        __f_ = (__base*)&__buf_;
-    }
-    else
-        _VSTD::swap(__f_, __f.__f_);
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-_Rp
-function<_Rp(_A0, _A1, _A2)>::operator()(_A0 __a0, _A1 __a1, _A2 __a2) const
-{
-    if (__f_ == 0)
-        __throw_bad_function_call();
-    return (*__f_)(__a0, __a1, __a2);
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Rp, class _A0, class _A1, class _A2>
-const std::type_info&
-function<_Rp(_A0, _A1, _A2)>::target_type() const
-{
-    if (__f_ == 0)
-        return typeid(void);
-    return __f_->target_type();
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-template <typename _Tp>
-_Tp*
-function<_Rp(_A0, _A1, _A2)>::target()
-{
-    if (__f_ == 0)
-        return (_Tp*)0;
-    return (_Tp*) const_cast<void *>(__f_->target(typeid(_Tp)));
-}
-
-template<class _Rp, class _A0, class _A1, class _A2>
-template <typename _Tp>
-const _Tp*
-function<_Rp(_A0, _A1, _A2)>::target() const
-{
-    if (__f_ == 0)
-        return (const _Tp*)0;
-    return (const _Tp*)__f_->target(typeid(_Tp));
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template <class _Fp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const function<_Fp>& __f, nullptr_t) {return !__f;}
-
-template <class _Fp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(nullptr_t, const function<_Fp>& __f) {return !__f;}
-
-template <class _Fp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const function<_Fp>& __f, nullptr_t) {return (bool)__f;}
-
-template <class _Fp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(nullptr_t, const function<_Fp>& __f) {return (bool)__f;}
-
-template <class _Fp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(function<_Fp>& __x, function<_Fp>& __y)
-{return __x.swap(__y);}
-
-#endif  // _LIBCPP_FUNCTIONAL_03
diff --git a/lib/libcxx/include/__functional_base b/lib/libcxx/include/__functional_base
deleted file mode 100644
index 032be99bf6a..00000000000
--- a/lib/libcxx/include/__functional_base
+++ /dev/null
@@ -1,653 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_FUNCTIONAL_BASE
-#define _LIBCPP_FUNCTIONAL_BASE
-
-#include <__config>
-#include <type_traits>
-#include <typeinfo>
-#include <exception>
-#include <new>
-#include <utility>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Arg1, class _Arg2, class _Result>
-struct _LIBCPP_TEMPLATE_VIS binary_function
-{
-    typedef _Arg1   first_argument_type;
-    typedef _Arg2   second_argument_type;
-    typedef _Result result_type;
-};
-
-template <class _Tp>
-struct __has_result_type
-{
-private:
-    struct __two {char __lx; char __lxx;};
-    template <class _Up> static __two __test(...);
-    template <class _Up> static char __test(typename _Up::result_type* = 0);
-public:
-    static const bool value = sizeof(__test<_Tp>(0)) == 1;
-};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS less : binary_function<_Tp, _Tp, bool>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x < __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS less<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) < _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-// __weak_result_type
-
-template <class _Tp>
-struct __derives_from_unary_function
-{
-private:
-    struct __two {char __lx; char __lxx;};
-    static __two __test(...);
-    template <class _Ap, class _Rp>
-        static unary_function<_Ap, _Rp>
-        __test(const volatile unary_function<_Ap, _Rp>*);
-public:
-    static const bool value = !is_same<decltype(__test((_Tp*)0)), __two>::value;
-    typedef decltype(__test((_Tp*)0)) type;
-};
-
-template <class _Tp>
-struct __derives_from_binary_function
-{
-private:
-    struct __two {char __lx; char __lxx;};
-    static __two __test(...);
-    template <class _A1, class _A2, class _Rp>
-        static binary_function<_A1, _A2, _Rp>
-        __test(const volatile binary_function<_A1, _A2, _Rp>*);
-public:
-    static const bool value = !is_same<decltype(__test((_Tp*)0)), __two>::value;
-    typedef decltype(__test((_Tp*)0)) type;
-};
-
-template <class _Tp, bool = __derives_from_unary_function<_Tp>::value>
-struct __maybe_derive_from_unary_function  // bool is true
-    : public __derives_from_unary_function<_Tp>::type
-{
-};
-
-template <class _Tp>
-struct __maybe_derive_from_unary_function<_Tp, false>
-{
-};
-
-template <class _Tp, bool = __derives_from_binary_function<_Tp>::value>
-struct __maybe_derive_from_binary_function  // bool is true
-    : public __derives_from_binary_function<_Tp>::type
-{
-};
-
-template <class _Tp>
-struct __maybe_derive_from_binary_function<_Tp, false>
-{
-};
-
-template <class _Tp, bool = __has_result_type<_Tp>::value>
-struct __weak_result_type_imp // bool is true
-    : public __maybe_derive_from_unary_function<_Tp>,
-      public __maybe_derive_from_binary_function<_Tp>
-{
-    typedef typename _Tp::result_type result_type;
-};
-
-template <class _Tp>
-struct __weak_result_type_imp<_Tp, false>
-    : public __maybe_derive_from_unary_function<_Tp>,
-      public __maybe_derive_from_binary_function<_Tp>
-{
-};
-
-template <class _Tp>
-struct __weak_result_type
-    : public __weak_result_type_imp<_Tp>
-{
-};
-
-// 0 argument case
-
-template <class _Rp>
-struct __weak_result_type<_Rp ()>
-{
-    typedef _Rp result_type;
-};
-
-template <class _Rp>
-struct __weak_result_type<_Rp (&)()>
-{
-    typedef _Rp result_type;
-};
-
-template <class _Rp>
-struct __weak_result_type<_Rp (*)()>
-{
-    typedef _Rp result_type;
-};
-
-// 1 argument case
-
-template <class _Rp, class _A1>
-struct __weak_result_type<_Rp (_A1)>
-    : public unary_function<_A1, _Rp>
-{
-};
-
-template <class _Rp, class _A1>
-struct __weak_result_type<_Rp (&)(_A1)>
-    : public unary_function<_A1, _Rp>
-{
-};
-
-template <class _Rp, class _A1>
-struct __weak_result_type<_Rp (*)(_A1)>
-    : public unary_function<_A1, _Rp>
-{
-};
-
-template <class _Rp, class _Cp>
-struct __weak_result_type<_Rp (_Cp::*)()>
-    : public unary_function<_Cp*, _Rp>
-{
-};
-
-template <class _Rp, class _Cp>
-struct __weak_result_type<_Rp (_Cp::*)() const>
-    : public unary_function<const _Cp*, _Rp>
-{
-};
-
-template <class _Rp, class _Cp>
-struct __weak_result_type<_Rp (_Cp::*)() volatile>
-    : public unary_function<volatile _Cp*, _Rp>
-{
-};
-
-template <class _Rp, class _Cp>
-struct __weak_result_type<_Rp (_Cp::*)() const volatile>
-    : public unary_function<const volatile _Cp*, _Rp>
-{
-};
-
-// 2 argument case
-
-template <class _Rp, class _A1, class _A2>
-struct __weak_result_type<_Rp (_A1, _A2)>
-    : public binary_function<_A1, _A2, _Rp>
-{
-};
-
-template <class _Rp, class _A1, class _A2>
-struct __weak_result_type<_Rp (*)(_A1, _A2)>
-    : public binary_function<_A1, _A2, _Rp>
-{
-};
-
-template <class _Rp, class _A1, class _A2>
-struct __weak_result_type<_Rp (&)(_A1, _A2)>
-    : public binary_function<_A1, _A2, _Rp>
-{
-};
-
-template <class _Rp, class _Cp, class _A1>
-struct __weak_result_type<_Rp (_Cp::*)(_A1)>
-    : public binary_function<_Cp*, _A1, _Rp>
-{
-};
-
-template <class _Rp, class _Cp, class _A1>
-struct __weak_result_type<_Rp (_Cp::*)(_A1) const>
-    : public binary_function<const _Cp*, _A1, _Rp>
-{
-};
-
-template <class _Rp, class _Cp, class _A1>
-struct __weak_result_type<_Rp (_Cp::*)(_A1) volatile>
-    : public binary_function<volatile _Cp*, _A1, _Rp>
-{
-};
-
-template <class _Rp, class _Cp, class _A1>
-struct __weak_result_type<_Rp (_Cp::*)(_A1) const volatile>
-    : public binary_function<const volatile _Cp*, _A1, _Rp>
-{
-};
-
-
-#ifndef _LIBCPP_CXX03_LANG
-// 3 or more arguments
-
-template <class _Rp, class _A1, class _A2, class _A3, class ..._A4>
-struct __weak_result_type<_Rp (_A1, _A2, _A3, _A4...)>
-{
-    typedef _Rp result_type;
-};
-
-template <class _Rp, class _A1, class _A2, class _A3, class ..._A4>
-struct __weak_result_type<_Rp (&)(_A1, _A2, _A3, _A4...)>
-{
-    typedef _Rp result_type;
-};
-
-template <class _Rp, class _A1, class _A2, class _A3, class ..._A4>
-struct __weak_result_type<_Rp (*)(_A1, _A2, _A3, _A4...)>
-{
-    typedef _Rp result_type;
-};
-
-template <class _Rp, class _Cp, class _A1, class _A2, class ..._A3>
-struct __weak_result_type<_Rp (_Cp::*)(_A1, _A2, _A3...)>
-{
-    typedef _Rp result_type;
-};
-
-template <class _Rp, class _Cp, class _A1, class _A2, class ..._A3>
-struct __weak_result_type<_Rp (_Cp::*)(_A1, _A2, _A3...) const>
-{
-    typedef _Rp result_type;
-};
-
-template <class _Rp, class _Cp, class _A1, class _A2, class ..._A3>
-struct __weak_result_type<_Rp (_Cp::*)(_A1, _A2, _A3...) volatile>
-{
-    typedef _Rp result_type;
-};
-
-template <class _Rp, class _Cp, class _A1, class _A2, class ..._A3>
-struct __weak_result_type<_Rp (_Cp::*)(_A1, _A2, _A3...) const volatile>
-{
-    typedef _Rp result_type;
-};
-
-template <class _Tp, class ..._Args>
-struct __invoke_return
-{
-    typedef decltype(__invoke(_VSTD::declval<_Tp>(), _VSTD::declval<_Args>()...)) type;
-};
-
-#else // defined(_LIBCPP_CXX03_LANG)
-
-#include <__functional_base_03>
-
-#endif  // !defined(_LIBCPP_CXX03_LANG)
-
-
-template <class _Ret>
-struct __invoke_void_return_wrapper
-{
-#ifndef _LIBCPP_CXX03_LANG
-    template <class ..._Args>
-    static _Ret __call(_Args&&... __args) {
-        return __invoke(_VSTD::forward<_Args>(__args)...);
-    }
-#else
-    template <class _Fn>
-    static _Ret __call(_Fn __f) {
-        return __invoke(__f);
-    }
-
-    template <class _Fn, class _A0>
-    static _Ret __call(_Fn __f, _A0& __a0) {
-        return __invoke(__f, __a0);
-    }
-
-    template <class _Fn, class _A0, class _A1>
-    static _Ret __call(_Fn __f, _A0& __a0, _A1& __a1) {
-        return __invoke(__f, __a0, __a1);
-    }
-
-    template <class _Fn, class _A0, class _A1, class _A2>
-    static _Ret __call(_Fn __f, _A0& __a0, _A1& __a1, _A2& __a2){
-        return __invoke(__f, __a0, __a1, __a2);
-    }
-#endif
-};
-
-template <>
-struct __invoke_void_return_wrapper<void>
-{
-#ifndef _LIBCPP_CXX03_LANG
-    template <class ..._Args>
-    static void __call(_Args&&... __args) {
-        __invoke(_VSTD::forward<_Args>(__args)...);
-    }
-#else
-    template <class _Fn>
-    static void __call(_Fn __f) {
-        __invoke(__f);
-    }
-
-    template <class _Fn, class _A0>
-    static void __call(_Fn __f, _A0& __a0) {
-        __invoke(__f, __a0);
-    }
-
-    template <class _Fn, class _A0, class _A1>
-    static void __call(_Fn __f, _A0& __a0, _A1& __a1) {
-        __invoke(__f, __a0, __a1);
-    }
-
-    template <class _Fn, class _A0, class _A1, class _A2>
-    static void __call(_Fn __f, _A0& __a0, _A1& __a1, _A2& __a2) {
-        __invoke(__f, __a0, __a1, __a2);
-    }
-#endif
-};
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS reference_wrapper
-    : public __weak_result_type<_Tp>
-{
-public:
-    // types
-    typedef _Tp type;
-private:
-    type* __f_;
-
-public:
-    // construct/copy/destroy
-    _LIBCPP_INLINE_VISIBILITY reference_wrapper(type& __f) _NOEXCEPT
-        : __f_(_VSTD::addressof(__f)) {}
-#ifndef _LIBCPP_CXX03_LANG
-    private: reference_wrapper(type&&); public: // = delete; // do not bind to temps
-#endif
-
-    // access
-    _LIBCPP_INLINE_VISIBILITY operator type&    () const _NOEXCEPT {return *__f_;}
-    _LIBCPP_INLINE_VISIBILITY          type& get() const _NOEXCEPT {return *__f_;}
-
-#ifndef _LIBCPP_CXX03_LANG
-    // invoke
-    template <class... _ArgTypes>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_of<type&, _ArgTypes...>::type
-    operator() (_ArgTypes&&... __args) const {
-        return __invoke(get(), _VSTD::forward<_ArgTypes>(__args)...);
-    }
-#else
-
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return<type>::type
-    operator() () const {
-        return __invoke(get());
-    }
-
-    template <class _A0>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return0<type, _A0>::type
-    operator() (_A0& __a0) const {
-        return __invoke(get(), __a0);
-    }
-
-    template <class _A0>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return0<type, _A0 const>::type
-    operator() (_A0 const& __a0) const {
-        return __invoke(get(), __a0);
-    }
-
-    template <class _A0, class _A1>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return1<type, _A0, _A1>::type
-    operator() (_A0& __a0, _A1& __a1) const {
-        return __invoke(get(), __a0, __a1);
-    }
-
-    template <class _A0, class _A1>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return1<type, _A0 const, _A1>::type
-    operator() (_A0 const& __a0, _A1& __a1) const {
-        return __invoke(get(), __a0, __a1);
-    }
-
-    template <class _A0, class _A1>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return1<type, _A0, _A1 const>::type
-    operator() (_A0& __a0, _A1 const& __a1) const {
-        return __invoke(get(), __a0, __a1);
-    }
-
-    template <class _A0, class _A1>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return1<type, _A0 const, _A1 const>::type
-    operator() (_A0 const& __a0, _A1 const& __a1) const {
-        return __invoke(get(), __a0, __a1);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0, _A1, _A2>::type
-    operator() (_A0& __a0, _A1& __a1, _A2& __a2) const {
-        return __invoke(get(), __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0 const, _A1, _A2>::type
-    operator() (_A0 const& __a0, _A1& __a1, _A2& __a2) const {
-        return __invoke(get(), __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0, _A1 const, _A2>::type
-    operator() (_A0& __a0, _A1 const& __a1, _A2& __a2) const {
-        return __invoke(get(), __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0, _A1, _A2 const>::type
-    operator() (_A0& __a0, _A1& __a1, _A2 const& __a2) const {
-        return __invoke(get(), __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0 const, _A1 const, _A2>::type
-    operator() (_A0 const& __a0, _A1 const& __a1, _A2& __a2) const {
-        return __invoke(get(), __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0 const, _A1, _A2 const>::type
-    operator() (_A0 const& __a0, _A1& __a1, _A2 const& __a2) const {
-        return __invoke(get(), __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0, _A1 const, _A2 const>::type
-    operator() (_A0& __a0, _A1 const& __a1, _A2 const& __a2) const {
-        return __invoke(get(), __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0 const, _A1 const, _A2 const>::type
-    operator() (_A0 const& __a0, _A1 const& __a1, _A2 const& __a2) const {
-        return __invoke(get(), __a0, __a1, __a2);
-    }
-#endif // _LIBCPP_CXX03_LANG
-};
-
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-reference_wrapper<_Tp>
-ref(_Tp& __t) _NOEXCEPT
-{
-    return reference_wrapper<_Tp>(__t);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-reference_wrapper<_Tp>
-ref(reference_wrapper<_Tp> __t) _NOEXCEPT
-{
-    return ref(__t.get());
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-reference_wrapper<const _Tp>
-cref(const _Tp& __t) _NOEXCEPT
-{
-    return reference_wrapper<const _Tp>(__t);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-reference_wrapper<const _Tp>
-cref(reference_wrapper<_Tp> __t) _NOEXCEPT
-{
-    return cref(__t.get());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp> void ref(const _Tp&&) = delete;
-template <class _Tp> void cref(const _Tp&&) = delete;
-#endif
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp, class, class = void>
-struct __is_transparent : false_type {};
-
-template <class _Tp, class _Up>
-struct __is_transparent<_Tp, _Up,
-                        typename __void_t<typename _Tp::is_transparent>::type>
-   : true_type {};
-#endif
-
-// allocator_arg_t
-
-struct _LIBCPP_TEMPLATE_VIS allocator_arg_t { };
-
-#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
-extern _LIBCPP_EXPORTED_FROM_ABI const allocator_arg_t allocator_arg;
-#else
-/* _LIBCPP_INLINE_VAR */ constexpr allocator_arg_t allocator_arg = allocator_arg_t();
-#endif
-
-// uses_allocator
-
-template <class _Tp>
-struct __has_allocator_type
-{
-private:
-    struct __two {char __lx; char __lxx;};
-    template <class _Up> static __two __test(...);
-    template <class _Up> static char __test(typename _Up::allocator_type* = 0);
-public:
-    static const bool value = sizeof(__test<_Tp>(0)) == 1;
-};
-
-template <class _Tp, class _Alloc, bool = __has_allocator_type<_Tp>::value>
-struct __uses_allocator
-    : public integral_constant<bool,
-        is_convertible<_Alloc, typename _Tp::allocator_type>::value>
-{
-};
-
-template <class _Tp, class _Alloc>
-struct __uses_allocator<_Tp, _Alloc, false>
-    : public false_type
-{
-};
-
-template <class _Tp, class _Alloc>
-struct _LIBCPP_TEMPLATE_VIS uses_allocator
-    : public __uses_allocator<_Tp, _Alloc>
-{
-};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp, class _Alloc>
-_LIBCPP_INLINE_VAR constexpr size_t uses_allocator_v = uses_allocator<_Tp, _Alloc>::value;
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-
-// allocator construction
-
-template <class _Tp, class _Alloc, class ..._Args>
-struct __uses_alloc_ctor_imp
-{
-    typedef typename __uncvref<_Alloc>::type _RawAlloc;
-    static const bool __ua = uses_allocator<_Tp, _RawAlloc>::value;
-    static const bool __ic =
-        is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value;
-    static const int value = __ua ? 2 - __ic : 0;
-};
-
-template <class _Tp, class _Alloc, class ..._Args>
-struct __uses_alloc_ctor
-    : integral_constant<int, __uses_alloc_ctor_imp<_Tp, _Alloc, _Args...>::value>
-    {};
-
-template <class _Tp, class _Allocator, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-void __user_alloc_construct_impl (integral_constant<int, 0>, _Tp *__storage, const _Allocator &, _Args &&... __args )
-{
-    new (__storage) _Tp (_VSTD::forward<_Args>(__args)...);
-}
-
-// FIXME: This should have a version which takes a non-const alloc.
-template <class _Tp, class _Allocator, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-void __user_alloc_construct_impl (integral_constant<int, 1>, _Tp *__storage, const _Allocator &__a, _Args &&... __args )
-{
-    new (__storage) _Tp (allocator_arg, __a, _VSTD::forward<_Args>(__args)...);
-}
-
-// FIXME: This should have a version which takes a non-const alloc.
-template <class _Tp, class _Allocator, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-void __user_alloc_construct_impl (integral_constant<int, 2>, _Tp *__storage, const _Allocator &__a, _Args &&... __args )
-{
-    new (__storage) _Tp (_VSTD::forward<_Args>(__args)..., __a);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_FUNCTIONAL_BASE
diff --git a/lib/libcxx/include/__functional_base_03 b/lib/libcxx/include/__functional_base_03
deleted file mode 100644
index 8407dcfa39c..00000000000
--- a/lib/libcxx/include/__functional_base_03
+++ /dev/null
@@ -1,224 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_FUNCTIONAL_BASE_03
-#define _LIBCPP_FUNCTIONAL_BASE_03
-
-// manual variadic expansion for <functional>
-
-// __invoke
-
-template <class _Ret, class _T1, bool _IsFunc, bool _IsBase>
-struct __enable_invoke_imp;
-
-template <class _Ret, class _T1>
-struct __enable_invoke_imp<_Ret, _T1, true, true> {
-    typedef _Ret _Bullet1;
-    typedef _Bullet1 type;
-};
-
-template <class _Ret, class _T1>
-struct __enable_invoke_imp<_Ret, _T1, true, false>  {
-    typedef _Ret _Bullet2;
-    typedef _Bullet2 type;
-};
-
-template <class _Ret, class _T1>
-struct __enable_invoke_imp<_Ret, _T1, false, true>  {
-    typedef typename add_lvalue_reference<
-                typename __apply_cv<_T1, _Ret>::type
-            >::type _Bullet3;
-    typedef _Bullet3 type;
-};
-
-template <class _Ret, class _T1>
-struct __enable_invoke_imp<_Ret, _T1, false, false>  {
-    typedef typename add_lvalue_reference<
-                typename __apply_cv<decltype(*_VSTD::declval<_T1>()), _Ret>::type
-            >::type _Bullet4;
-    typedef _Bullet4 type;
-};
-
-template <class _Ret, class _T1>
-struct __enable_invoke_imp<_Ret, _T1*, false, false>  {
-    typedef typename add_lvalue_reference<
-                typename __apply_cv<_T1, _Ret>::type
-            >::type _Bullet4;
-    typedef _Bullet4  type;
-};
-
-template <class _Fn, class _T1,
-          class _Traits = __member_pointer_traits<_Fn>,
-          class _Ret = typename _Traits::_ReturnType,
-          class _Class = typename _Traits::_ClassType>
-struct __enable_invoke : __enable_invoke_imp<
-    _Ret, _T1,
-    is_member_function_pointer<_Fn>::value,
-    is_base_of<_Class, typename remove_reference<_T1>::type>::value>
-{
-};
-
-__nat __invoke(__any, ...);
-
-// first bullet
-
-template <class _Fn, class _T1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet1
-__invoke(_Fn __f, _T1& __t1) {
-    return (__t1.*__f)();
-}
-
-template <class _Fn, class _T1, class _A0>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet1
-__invoke(_Fn __f, _T1& __t1, _A0& __a0) {
-    return (__t1.*__f)(__a0);
-}
-
-template <class _Fn, class _T1, class _A0, class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet1
-__invoke(_Fn __f, _T1& __t1, _A0& __a0, _A1& __a1) {
-    return (__t1.*__f)(__a0, __a1);
-}
-
-template <class _Fn, class _T1, class _A0, class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet1
-__invoke(_Fn __f, _T1& __t1, _A0& __a0, _A1& __a1, _A2& __a2) {
-    return (__t1.*__f)(__a0, __a1, __a2);
-}
-
-template <class _Fn, class _T1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet2
-__invoke(_Fn __f, _T1& __t1) {
-    return ((*__t1).*__f)();
-}
-
-template <class _Fn, class _T1, class _A0>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet2
-__invoke(_Fn __f, _T1& __t1, _A0& __a0) {
-    return ((*__t1).*__f)(__a0);
-}
-
-template <class _Fn, class _T1, class _A0, class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet2
-__invoke(_Fn __f, _T1& __t1, _A0& __a0, _A1& __a1) {
-    return ((*__t1).*__f)(__a0, __a1);
-}
-
-template <class _Fn, class _T1, class _A0, class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet2
-__invoke(_Fn __f, _T1& __t1, _A0& __a0, _A1& __a1, _A2& __a2) {
-    return ((*__t1).*__f)(__a0, __a1, __a2);
-}
-
-template <class _Fn, class _T1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet3
-__invoke(_Fn __f, _T1& __t1) {
-    return __t1.*__f;
-}
-
-template <class _Fn, class _T1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __enable_invoke<_Fn, _T1>::_Bullet4
-__invoke(_Fn __f, _T1& __t1) {
-    return (*__t1).*__f;
-}
-
-// fifth bullet
-
-template <class _Fp>
-inline _LIBCPP_INLINE_VISIBILITY
-decltype(_VSTD::declval<_Fp&>()())
-__invoke(_Fp& __f)
-{
-    return __f();
-}
-
-template <class _Fp, class _A0>
-inline _LIBCPP_INLINE_VISIBILITY
-decltype(_VSTD::declval<_Fp&>()(_VSTD::declval<_A0&>()))
-__invoke(_Fp& __f, _A0& __a0)
-{
-    return __f(__a0);
-}
-
-template <class _Fp, class _A0, class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-decltype(_VSTD::declval<_Fp&>()(_VSTD::declval<_A0&>(), _VSTD::declval<_A1&>()))
-__invoke(_Fp& __f, _A0& __a0, _A1& __a1)
-{
-    return __f(__a0, __a1);
-}
-
-template <class _Fp, class _A0, class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-decltype(_VSTD::declval<_Fp&>()(_VSTD::declval<_A0&>(), _VSTD::declval<_A1&>(), _VSTD::declval<_A2&>()))
-__invoke(_Fp& __f, _A0& __a0, _A1& __a1, _A2& __a2)
-{
-    return __f(__a0, __a1, __a2);
-}
-
-template <class _Fp, bool = __has_result_type<__weak_result_type<_Fp> >::value>
-struct __invoke_return
-{
-    typedef typename __weak_result_type<_Fp>::result_type type;
-};
-
-template <class _Fp>
-struct __invoke_return<_Fp, false>
-{
-    typedef decltype(__invoke(_VSTD::declval<_Fp&>())) type;
-};
-
-template <class _Tp, class _A0>
-struct __invoke_return0
-{
-    typedef decltype(__invoke(_VSTD::declval<_Tp&>(), _VSTD::declval<_A0&>())) type;
-};
-
-template <class _Rp, class _Tp, class _A0>
-struct __invoke_return0<_Rp _Tp::*, _A0>
-{
-    typedef typename __enable_invoke<_Rp _Tp::*, _A0>::type type;
-};
-
-template <class _Tp, class _A0, class _A1>
-struct __invoke_return1
-{
-    typedef decltype(__invoke(_VSTD::declval<_Tp&>(), _VSTD::declval<_A0&>(),
-                                                      _VSTD::declval<_A1&>())) type;
-};
-
-template <class _Rp, class _Class, class _A0, class _A1>
-struct __invoke_return1<_Rp _Class::*, _A0, _A1> {
-    typedef typename __enable_invoke<_Rp _Class::*, _A0>::type type;
-};
-
-template <class _Tp, class _A0, class _A1, class _A2>
-struct __invoke_return2
-{
-    typedef decltype(__invoke(_VSTD::declval<_Tp&>(), _VSTD::declval<_A0&>(),
-                                                      _VSTD::declval<_A1&>(),
-                                                      _VSTD::declval<_A2&>())) type;
-};
-
-template <class _Ret, class _Class, class _A0, class _A1, class _A2>
-struct __invoke_return2<_Ret _Class::*, _A0, _A1, _A2> {
-    typedef typename __enable_invoke<_Ret _Class::*, _A0>::type type;
-};
-#endif  // _LIBCPP_FUNCTIONAL_BASE_03
diff --git a/lib/libcxx/include/__hash_table b/lib/libcxx/include/__hash_table
deleted file mode 100644
index 6f5b183105e..00000000000
--- a/lib/libcxx/include/__hash_table
+++ /dev/null
@@ -1,2913 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP__HASH_TABLE
-#define _LIBCPP__HASH_TABLE
-
-#include <__config>
-#include <initializer_list>
-#include <memory>
-#include <iterator>
-#include <algorithm>
-#include <cmath>
-#include <utility>
-#include <type_traits>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Key, class _Tp>
-struct __hash_value_type;
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp>
-struct __is_hash_value_type_imp : false_type {};
-
-template <class _Key, class _Value>
-struct __is_hash_value_type_imp<__hash_value_type<_Key, _Value>> : true_type {};
-
-template <class ..._Args>
-struct __is_hash_value_type : false_type {};
-
-template <class _One>
-struct __is_hash_value_type<_One> : __is_hash_value_type_imp<typename __uncvref<_One>::type> {};
-#endif
-
-_LIBCPP_FUNC_VIS
-size_t __next_prime(size_t __n);
-
-template <class _NodePtr>
-struct __hash_node_base
-{
-    typedef typename pointer_traits<_NodePtr>::element_type __node_type;
-    typedef __hash_node_base __first_node;
-    typedef typename __rebind_pointer<_NodePtr, __first_node>::type __node_base_pointer;
-    typedef _NodePtr __node_pointer;
-
-#if defined(_LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB)
-  typedef __node_base_pointer __next_pointer;
-#else
-  typedef typename conditional<
-      is_pointer<__node_pointer>::value,
-      __node_base_pointer,
-      __node_pointer>::type   __next_pointer;
-#endif
-
-    __next_pointer    __next_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __next_pointer __ptr() _NOEXCEPT {
-        return static_cast<__next_pointer>(
-            pointer_traits<__node_base_pointer>::pointer_to(*this));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __upcast() _NOEXCEPT {
-        return static_cast<__node_pointer>(
-            pointer_traits<__node_base_pointer>::pointer_to(*this));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t __hash() const _NOEXCEPT {
-        return static_cast<__node_type const&>(*this).__hash_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __hash_node_base() _NOEXCEPT : __next_(nullptr) {}
-};
-
-template <class _Tp, class _VoidPtr>
-struct __hash_node
-    : public __hash_node_base
-             <
-                 typename __rebind_pointer<_VoidPtr, __hash_node<_Tp, _VoidPtr> >::type
-             >
-{
-    typedef _Tp __node_value_type;
-
-    size_t            __hash_;
-    __node_value_type __value_;
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-__is_hash_power2(size_t __bc)
-{
-    return __bc > 2 && !(__bc & (__bc - 1));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-size_t
-__constrain_hash(size_t __h, size_t __bc)
-{
-    return !(__bc & (__bc - 1)) ? __h & (__bc - 1) :
-        (__h < __bc ? __h : __h % __bc);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-size_t
-__next_hash_pow2(size_t __n)
-{
-    return __n < 2 ? __n : (size_t(1) << (std::numeric_limits<size_t>::digits - __clz(__n-1)));
-}
-
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc> class __hash_table;
-
-template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_iterator;
-template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
-template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_local_iterator;
-template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
-template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
-template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
-
-template <class _Tp>
-struct __hash_key_value_types {
-  static_assert(!is_reference<_Tp>::value && !is_const<_Tp>::value, "");
-  typedef _Tp key_type;
-  typedef _Tp __node_value_type;
-  typedef _Tp __container_value_type;
-  static const bool __is_map = false;
-
-  _LIBCPP_INLINE_VISIBILITY
-  static key_type const& __get_key(_Tp const& __v) {
-    return __v;
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type const& __get_value(__node_value_type const& __v) {
-    return __v;
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type* __get_ptr(__node_value_type& __n) {
-    return _VSTD::addressof(__n);
-  }
-#ifndef _LIBCPP_CXX03_LANG
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type&& __move(__node_value_type& __v) {
-    return _VSTD::move(__v);
-  }
-#endif
-};
-
-template <class _Key, class _Tp>
-struct __hash_key_value_types<__hash_value_type<_Key, _Tp> > {
-  typedef _Key                                         key_type;
-  typedef _Tp                                          mapped_type;
-  typedef __hash_value_type<_Key, _Tp>                 __node_value_type;
-  typedef pair<const _Key, _Tp>                        __container_value_type;
-  typedef __container_value_type                       __map_value_type;
-  static const bool __is_map = true;
-
-  _LIBCPP_INLINE_VISIBILITY
-  static key_type const& __get_key(__container_value_type const& __v) {
-    return __v.first;
-  }
-
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  static typename enable_if<__is_same_uncvref<_Up, __node_value_type>::value,
-      __container_value_type const&>::type
-  __get_value(_Up& __t) {
-    return __t.__get_value();
-  }
-
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value,
-      __container_value_type const&>::type
-  __get_value(_Up& __t) {
-    return __t;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type* __get_ptr(__node_value_type& __n) {
-    return _VSTD::addressof(__n.__get_value());
-  }
-#ifndef _LIBCPP_CXX03_LANG
-  _LIBCPP_INLINE_VISIBILITY
-  static pair<key_type&&, mapped_type&&> __move(__node_value_type& __v) {
-    return __v.__move();
-  }
-#endif
-
-};
-
-template <class _Tp, class _AllocPtr, class _KVTypes = __hash_key_value_types<_Tp>,
-          bool = _KVTypes::__is_map>
-struct __hash_map_pointer_types {};
-
-template <class _Tp, class _AllocPtr, class _KVTypes>
-struct __hash_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> {
-  typedef typename _KVTypes::__map_value_type   _Mv;
-  typedef typename __rebind_pointer<_AllocPtr, _Mv>::type
-                                                       __map_value_type_pointer;
-  typedef typename __rebind_pointer<_AllocPtr, const _Mv>::type
-                                                 __const_map_value_type_pointer;
-};
-
-template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type>
-struct __hash_node_types;
-
-template <class _NodePtr, class _Tp, class _VoidPtr>
-struct __hash_node_types<_NodePtr, __hash_node<_Tp, _VoidPtr> >
-    : public __hash_key_value_types<_Tp>, __hash_map_pointer_types<_Tp, _VoidPtr>
-
-{
-  typedef __hash_key_value_types<_Tp>           __base;
-
-public:
-  typedef ptrdiff_t difference_type;
-  typedef size_t size_type;
-
-  typedef typename __rebind_pointer<_NodePtr, void>::type       __void_pointer;
-
-  typedef typename pointer_traits<_NodePtr>::element_type       __node_type;
-  typedef _NodePtr                                              __node_pointer;
-
-  typedef __hash_node_base<__node_pointer>                      __node_base_type;
-  typedef typename __rebind_pointer<_NodePtr, __node_base_type>::type
-                                                             __node_base_pointer;
-
-  typedef typename __node_base_type::__next_pointer          __next_pointer;
-
-  typedef _Tp                                                 __node_value_type;
-  typedef typename __rebind_pointer<_VoidPtr, __node_value_type>::type
-                                                      __node_value_type_pointer;
-  typedef typename __rebind_pointer<_VoidPtr, const __node_value_type>::type
-                                                __const_node_value_type_pointer;
-
-private:
-    static_assert(!is_const<__node_type>::value,
-                "_NodePtr should never be a pointer to const");
-    static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value),
-                  "_VoidPtr does not point to unqualified void type");
-    static_assert((is_same<typename __rebind_pointer<_VoidPtr, __node_type>::type,
-                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr.");
-};
-
-template <class _HashIterator>
-struct __hash_node_types_from_iterator;
-template <class _NodePtr>
-struct __hash_node_types_from_iterator<__hash_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
-template <class _NodePtr>
-struct __hash_node_types_from_iterator<__hash_const_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
-template <class _NodePtr>
-struct __hash_node_types_from_iterator<__hash_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
-template <class _NodePtr>
-struct __hash_node_types_from_iterator<__hash_const_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
-
-
-template <class _NodeValueTp, class _VoidPtr>
-struct __make_hash_node_types {
-  typedef __hash_node<_NodeValueTp, _VoidPtr> _NodeTp;
-  typedef typename __rebind_pointer<_VoidPtr, _NodeTp>::type _NodePtr;
-  typedef __hash_node_types<_NodePtr> type;
-};
-
-template <class _NodePtr>
-class _LIBCPP_TEMPLATE_VIS __hash_iterator
-{
-    typedef __hash_node_types<_NodePtr> _NodeTypes;
-    typedef _NodePtr                            __node_pointer;
-    typedef typename _NodeTypes::__next_pointer __next_pointer;
-
-    __next_pointer            __node_;
-
-public:
-    typedef forward_iterator_tag                           iterator_category;
-    typedef typename _NodeTypes::__node_value_type         value_type;
-    typedef typename _NodeTypes::difference_type           difference_type;
-    typedef value_type&                                    reference;
-    typedef typename _NodeTypes::__node_value_type_pointer pointer;
-
-    _LIBCPP_INLINE_VISIBILITY __hash_iterator() _NOEXCEPT : __node_(nullptr) {
-        _LIBCPP_DEBUG_MODE(__get_db()->__insert_i(this));
-    }
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_iterator(const __hash_iterator& __i)
-        : __node_(__i.__node_)
-    {
-        __get_db()->__iterator_copy(this, &__i);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__hash_iterator()
-    {
-        __get_db()->__erase_i(this);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_iterator& operator=(const __hash_iterator& __i)
-    {
-        if (this != &__i)
-        {
-            __get_db()->__iterator_copy(this, &__i);
-            __node_ = __i.__node_;
-        }
-        return *this;
-    }
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                             "Attempted to dereference a non-dereferenceable unordered container iterator");
-        return __node_->__upcast()->__value_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                           "Attempted to dereference a non-dereferenceable unordered container iterator");
-        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_iterator& operator++() {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to increment non-incrementable unordered container iterator");
-        __node_ = __node_->__next_;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_iterator operator++(int)
-    {
-        __hash_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __hash_iterator& __x, const __hash_iterator& __y)
-    {
-        return __x.__node_ == __y.__node_;
-    }
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __hash_iterator& __x, const __hash_iterator& __y)
-        {return !(__x == __y);}
-
-private:
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_iterator(__next_pointer __node, const void* __c) _NOEXCEPT
-        : __node_(__node)
-        {
-            __get_db()->__insert_ic(this, __c);
-        }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_iterator(__next_pointer __node) _NOEXCEPT
-        : __node_(__node)
-        {}
-#endif
-    template <class, class, class, class> friend class __hash_table;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
-};
-
-template <class _NodePtr>
-class _LIBCPP_TEMPLATE_VIS __hash_const_iterator
-{
-    static_assert(!is_const<typename pointer_traits<_NodePtr>::element_type>::value, "");
-    typedef __hash_node_types<_NodePtr> _NodeTypes;
-    typedef _NodePtr                            __node_pointer;
-    typedef typename _NodeTypes::__next_pointer __next_pointer;
-
-    __next_pointer __node_;
-
-public:
-    typedef __hash_iterator<_NodePtr> __non_const_iterator;
-
-    typedef forward_iterator_tag                                 iterator_category;
-    typedef typename _NodeTypes::__node_value_type               value_type;
-    typedef typename _NodeTypes::difference_type                 difference_type;
-    typedef const value_type&                                    reference;
-    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
-
-
-    _LIBCPP_INLINE_VISIBILITY __hash_const_iterator() _NOEXCEPT : __node_(nullptr) {
-        _LIBCPP_DEBUG_MODE(__get_db()->__insert_i(this));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_iterator(const __non_const_iterator& __x) _NOEXCEPT
-        : __node_(__x.__node_)
-    {
-        _LIBCPP_DEBUG_MODE(__get_db()->__iterator_copy(this, &__x));
-    }
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_iterator(const __hash_const_iterator& __i)
-        : __node_(__i.__node_)
-    {
-        __get_db()->__iterator_copy(this, &__i);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__hash_const_iterator()
-    {
-        __get_db()->__erase_i(this);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_iterator& operator=(const __hash_const_iterator& __i)
-    {
-        if (this != &__i)
-        {
-            __get_db()->__iterator_copy(this, &__i);
-            __node_ = __i.__node_;
-        }
-        return *this;
-    }
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
-        return __node_->__upcast()->__value_;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
-        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_iterator& operator++() {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                             "Attempted to increment non-incrementable unordered container const_iterator");
-        __node_ = __node_->__next_;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_iterator operator++(int)
-    {
-        __hash_const_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
-    {
-        return __x.__node_ == __y.__node_;
-    }
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
-        {return !(__x == __y);}
-
-private:
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_iterator(__next_pointer __node, const void* __c) _NOEXCEPT
-        : __node_(__node)
-        {
-            __get_db()->__insert_ic(this, __c);
-        }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_iterator(__next_pointer __node) _NOEXCEPT
-        : __node_(__node)
-        {}
-#endif
-    template <class, class, class, class> friend class __hash_table;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
-};
-
-template <class _NodePtr>
-class _LIBCPP_TEMPLATE_VIS __hash_local_iterator
-{
-    typedef __hash_node_types<_NodePtr> _NodeTypes;
-    typedef _NodePtr                            __node_pointer;
-    typedef typename _NodeTypes::__next_pointer __next_pointer;
-
-    __next_pointer         __node_;
-    size_t                 __bucket_;
-    size_t                 __bucket_count_;
-
-public:
-    typedef forward_iterator_tag                                iterator_category;
-    typedef typename _NodeTypes::__node_value_type              value_type;
-    typedef typename _NodeTypes::difference_type                difference_type;
-    typedef value_type&                                         reference;
-    typedef typename _NodeTypes::__node_value_type_pointer      pointer;
-
-    _LIBCPP_INLINE_VISIBILITY __hash_local_iterator() _NOEXCEPT : __node_(nullptr) {
-        _LIBCPP_DEBUG_MODE(__get_db()->__insert_i(this));
-    }
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_local_iterator(const __hash_local_iterator& __i)
-        : __node_(__i.__node_),
-          __bucket_(__i.__bucket_),
-          __bucket_count_(__i.__bucket_count_)
-    {
-        __get_db()->__iterator_copy(this, &__i);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__hash_local_iterator()
-    {
-        __get_db()->__erase_i(this);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_local_iterator& operator=(const __hash_local_iterator& __i)
-    {
-        if (this != &__i)
-        {
-            __get_db()->__iterator_copy(this, &__i);
-            __node_ = __i.__node_;
-            __bucket_ = __i.__bucket_;
-            __bucket_count_ = __i.__bucket_count_;
-        }
-        return *this;
-    }
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                           "Attempted to dereference a non-dereferenceable unordered container local_iterator");
-        return __node_->__upcast()->__value_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                             "Attempted to dereference a non-dereferenceable unordered container local_iterator");
-        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_local_iterator& operator++() {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to increment non-incrementable unordered container local_iterator");
-        __node_ = __node_->__next_;
-        if (__node_ != nullptr && __constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
-            __node_ = nullptr;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_local_iterator operator++(int)
-    {
-        __hash_local_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
-    {
-        return __x.__node_ == __y.__node_;
-    }
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
-        {return !(__x == __y);}
-
-private:
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_local_iterator(__next_pointer __node, size_t __bucket,
-                          size_t __bucket_count, const void* __c) _NOEXCEPT
-        : __node_(__node),
-          __bucket_(__bucket),
-          __bucket_count_(__bucket_count)
-        {
-            __get_db()->__insert_ic(this, __c);
-            if (__node_ != nullptr)
-                __node_ = __node_->__next_;
-        }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_local_iterator(__next_pointer __node, size_t __bucket,
-                          size_t __bucket_count) _NOEXCEPT
-        : __node_(__node),
-          __bucket_(__bucket),
-          __bucket_count_(__bucket_count)
-        {
-            if (__node_ != nullptr)
-                __node_ = __node_->__next_;
-        }
-#endif
-    template <class, class, class, class> friend class __hash_table;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
-};
-
-template <class _ConstNodePtr>
-class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator
-{
-    typedef __hash_node_types<_ConstNodePtr> _NodeTypes;
-    typedef _ConstNodePtr                       __node_pointer;
-    typedef typename _NodeTypes::__next_pointer __next_pointer;
-
-    __next_pointer         __node_;
-    size_t                 __bucket_;
-    size_t                 __bucket_count_;
-
-    typedef pointer_traits<__node_pointer>          __pointer_traits;
-    typedef typename __pointer_traits::element_type __node;
-    typedef typename remove_const<__node>::type     __non_const_node;
-    typedef typename __rebind_pointer<__node_pointer, __non_const_node>::type
-        __non_const_node_pointer;
-public:
-    typedef __hash_local_iterator<__non_const_node_pointer>
-                                                    __non_const_iterator;
-
-    typedef forward_iterator_tag                                 iterator_category;
-    typedef typename _NodeTypes::__node_value_type               value_type;
-    typedef typename _NodeTypes::difference_type                 difference_type;
-    typedef const value_type&                                    reference;
-    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
-
-
-    _LIBCPP_INLINE_VISIBILITY __hash_const_local_iterator() _NOEXCEPT : __node_(nullptr) {
-        _LIBCPP_DEBUG_MODE(__get_db()->__insert_i(this));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_local_iterator(const __non_const_iterator& __x) _NOEXCEPT
-        : __node_(__x.__node_),
-          __bucket_(__x.__bucket_),
-          __bucket_count_(__x.__bucket_count_)
-    {
-        _LIBCPP_DEBUG_MODE(__get_db()->__iterator_copy(this, &__x));
-    }
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_local_iterator(const __hash_const_local_iterator& __i)
-        : __node_(__i.__node_),
-          __bucket_(__i.__bucket_),
-          __bucket_count_(__i.__bucket_count_)
-    {
-        __get_db()->__iterator_copy(this, &__i);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__hash_const_local_iterator()
-    {
-        __get_db()->__erase_i(this);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_local_iterator& operator=(const __hash_const_local_iterator& __i)
-    {
-        if (this != &__i)
-        {
-            __get_db()->__iterator_copy(this, &__i);
-            __node_ = __i.__node_;
-            __bucket_ = __i.__bucket_;
-            __bucket_count_ = __i.__bucket_count_;
-        }
-        return *this;
-    }
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
-        return __node_->__upcast()->__value_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
-        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_local_iterator& operator++() {
-        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to increment non-incrementable unordered container const_local_iterator");
-        __node_ = __node_->__next_;
-        if (__node_ != nullptr && __constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
-            __node_ = nullptr;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_local_iterator operator++(int)
-    {
-        __hash_const_local_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
-    {
-        return __x.__node_ == __y.__node_;
-    }
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
-        {return !(__x == __y);}
-
-private:
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_local_iterator(__next_pointer __node, size_t __bucket,
-                                size_t __bucket_count, const void* __c) _NOEXCEPT
-        : __node_(__node),
-          __bucket_(__bucket),
-          __bucket_count_(__bucket_count)
-        {
-            __get_db()->__insert_ic(this, __c);
-            if (__node_ != nullptr)
-                __node_ = __node_->__next_;
-        }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_const_local_iterator(__next_pointer __node, size_t __bucket,
-                                size_t __bucket_count) _NOEXCEPT
-        : __node_(__node),
-          __bucket_(__bucket),
-          __bucket_count_(__bucket_count)
-        {
-            if (__node_ != nullptr)
-                __node_ = __node_->__next_;
-        }
-#endif
-    template <class, class, class, class> friend class __hash_table;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
-};
-
-template <class _Alloc>
-class __bucket_list_deallocator
-{
-    typedef _Alloc                                          allocator_type;
-    typedef allocator_traits<allocator_type>                __alloc_traits;
-    typedef typename __alloc_traits::size_type              size_type;
-
-    __compressed_pair<size_type, allocator_type> __data_;
-public:
-    typedef typename __alloc_traits::pointer pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __bucket_list_deallocator()
-        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
-        : __data_(0) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __bucket_list_deallocator(const allocator_type& __a, size_type __size)
-        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
-        : __data_(__size, __a) {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __bucket_list_deallocator(__bucket_list_deallocator&& __x)
-        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
-        : __data_(_VSTD::move(__x.__data_))
-    {
-        __x.size() = 0;
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type& size() _NOEXCEPT {return __data_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type  size() const _NOEXCEPT {return __data_.first();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type& __alloc() _NOEXCEPT {return __data_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const allocator_type& __alloc() const _NOEXCEPT {return __data_.second();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()(pointer __p) _NOEXCEPT
-    {
-        __alloc_traits::deallocate(__alloc(), __p, size());
-    }
-};
-
-template <class _Alloc> class __hash_map_node_destructor;
-
-template <class _Alloc>
-class __hash_node_destructor
-{
-    typedef _Alloc                                          allocator_type;
-    typedef allocator_traits<allocator_type>                __alloc_traits;
-
-public:
-    typedef typename __alloc_traits::pointer                pointer;
-private:
-    typedef __hash_node_types<pointer> _NodeTypes;
-
-    allocator_type& __na_;
-
-    __hash_node_destructor& operator=(const __hash_node_destructor&);
-
-public:
-    bool __value_constructed;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __hash_node_destructor(allocator_type& __na,
-                                    bool __constructed = false) _NOEXCEPT
-        : __na_(__na),
-          __value_constructed(__constructed)
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()(pointer __p) _NOEXCEPT
-    {
-        if (__value_constructed)
-            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_));
-        if (__p)
-            __alloc_traits::deallocate(__na_, __p, 1);
-    }
-
-    template <class> friend class __hash_map_node_destructor;
-};
-
-#if _LIBCPP_STD_VER > 14
-template <class _NodeType, class _Alloc>
-struct __generic_container_node_destructor;
-
-template <class _Tp, class _VoidPtr, class _Alloc>
-struct __generic_container_node_destructor<__hash_node<_Tp, _VoidPtr>, _Alloc>
-    : __hash_node_destructor<_Alloc>
-{
-    using __hash_node_destructor<_Alloc>::__hash_node_destructor;
-};
-#endif
-
-template <class _Key, class _Hash, class _Equal>
-struct __enforce_unordered_container_requirements {
-#ifndef _LIBCPP_CXX03_LANG
-    static_assert(__check_hash_requirements<_Key, _Hash>::value,
-    "the specified hash does not meet the Hash requirements");
-    static_assert(is_copy_constructible<_Equal>::value,
-    "the specified comparator is required to be copy constructible");
-#endif
-    typedef int type;
-};
-
-template <class _Key, class _Hash, class _Equal>
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Equal const&, _Key const&, _Key const&>::value,
-    "the specified comparator type does not provide a const call operator")
-    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Hash const&, _Key const&>::value,
-    "the specified hash functor does not provide a const call operator")
-#endif
-typename __enforce_unordered_container_requirements<_Key, _Hash, _Equal>::type
-__diagnose_unordered_container_requirements(int);
-
-// This dummy overload is used so that the compiler won't emit a spurious
-// "no matching function for call to __diagnose_unordered_xxx" diagnostic
-// when the overload above causes a hard error.
-template <class _Key, class _Hash, class _Equal>
-int __diagnose_unordered_container_requirements(void*);
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-class __hash_table
-{
-public:
-    typedef _Tp    value_type;
-    typedef _Hash  hasher;
-    typedef _Equal key_equal;
-    typedef _Alloc allocator_type;
-
-private:
-    typedef allocator_traits<allocator_type> __alloc_traits;
-    typedef typename
-      __make_hash_node_types<value_type, typename __alloc_traits::void_pointer>::type
-                                                                     _NodeTypes;
-public:
-
-    typedef typename _NodeTypes::__node_value_type           __node_value_type;
-    typedef typename _NodeTypes::__container_value_type      __container_value_type;
-    typedef typename _NodeTypes::key_type                    key_type;
-    typedef value_type&                              reference;
-    typedef const value_type&                        const_reference;
-    typedef typename __alloc_traits::pointer         pointer;
-    typedef typename __alloc_traits::const_pointer   const_pointer;
-#ifndef _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE
-    typedef typename __alloc_traits::size_type       size_type;
-#else
-    typedef typename _NodeTypes::size_type           size_type;
-#endif
-    typedef typename _NodeTypes::difference_type     difference_type;
-public:
-    // Create __node
-
-    typedef typename _NodeTypes::__node_type __node;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
-    typedef allocator_traits<__node_allocator>       __node_traits;
-    typedef typename _NodeTypes::__void_pointer      __void_pointer;
-    typedef typename _NodeTypes::__node_pointer      __node_pointer;
-    typedef typename _NodeTypes::__node_pointer      __node_const_pointer;
-    typedef typename _NodeTypes::__node_base_type    __first_node;
-    typedef typename _NodeTypes::__node_base_pointer __node_base_pointer;
-    typedef typename _NodeTypes::__next_pointer      __next_pointer;
-
-private:
-    // check for sane allocator pointer rebinding semantics. Rebinding the
-    // allocator for a new pointer type should be exactly the same as rebinding
-    // the pointer using 'pointer_traits'.
-    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value),
-                  "Allocator does not rebind pointers in a sane manner.");
-    typedef typename __rebind_alloc_helper<__node_traits, __first_node>::type
-        __node_base_allocator;
-    typedef allocator_traits<__node_base_allocator> __node_base_traits;
-    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value),
-                 "Allocator does not rebind pointers in a sane manner.");
-
-private:
-
-    typedef typename __rebind_alloc_helper<__node_traits, __next_pointer>::type __pointer_allocator;
-    typedef __bucket_list_deallocator<__pointer_allocator> __bucket_list_deleter;
-    typedef unique_ptr<__next_pointer[], __bucket_list_deleter> __bucket_list;
-    typedef allocator_traits<__pointer_allocator>          __pointer_alloc_traits;
-    typedef typename __bucket_list_deleter::pointer       __node_pointer_pointer;
-
-    // --- Member data begin ---
-    __bucket_list                                         __bucket_list_;
-    __compressed_pair<__first_node, __node_allocator>     __p1_;
-    __compressed_pair<size_type, hasher>                  __p2_;
-    __compressed_pair<float, key_equal>                   __p3_;
-    // --- Member data end ---
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type& size() _NOEXCEPT {return __p2_.first();}
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    size_type  size() const _NOEXCEPT {return __p2_.first();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    hasher& hash_function() _NOEXCEPT {return __p2_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const hasher& hash_function() const _NOEXCEPT {return __p2_.second();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    float& max_load_factor() _NOEXCEPT {return __p3_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-    float  max_load_factor() const _NOEXCEPT {return __p3_.first();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    key_equal& key_eq() _NOEXCEPT {return __p3_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const key_equal& key_eq() const _NOEXCEPT {return __p3_.second();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __node_allocator& __node_alloc() _NOEXCEPT {return __p1_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const __node_allocator& __node_alloc() const _NOEXCEPT
-        {return __p1_.second();}
-
-public:
-    typedef __hash_iterator<__node_pointer>                   iterator;
-    typedef __hash_const_iterator<__node_pointer>             const_iterator;
-    typedef __hash_local_iterator<__node_pointer>             local_iterator;
-    typedef __hash_const_local_iterator<__node_pointer>       const_local_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_table()
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<__bucket_list>::value &&
-            is_nothrow_default_constructible<__first_node>::value &&
-            is_nothrow_default_constructible<__node_allocator>::value &&
-            is_nothrow_default_constructible<hasher>::value &&
-            is_nothrow_default_constructible<key_equal>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_table(const hasher& __hf, const key_equal& __eql);
-    __hash_table(const hasher& __hf, const key_equal& __eql,
-                 const allocator_type& __a);
-    explicit __hash_table(const allocator_type& __a);
-    __hash_table(const __hash_table& __u);
-    __hash_table(const __hash_table& __u, const allocator_type& __a);
-#ifndef _LIBCPP_CXX03_LANG
-    __hash_table(__hash_table&& __u)
-        _NOEXCEPT_(
-            is_nothrow_move_constructible<__bucket_list>::value &&
-            is_nothrow_move_constructible<__first_node>::value &&
-            is_nothrow_move_constructible<__node_allocator>::value &&
-            is_nothrow_move_constructible<hasher>::value &&
-            is_nothrow_move_constructible<key_equal>::value);
-    __hash_table(__hash_table&& __u, const allocator_type& __a);
-#endif  // _LIBCPP_CXX03_LANG
-    ~__hash_table();
-
-    __hash_table& operator=(const __hash_table& __u);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_table& operator=(__hash_table&& __u)
-        _NOEXCEPT_(
-            __node_traits::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<__node_allocator>::value &&
-            is_nothrow_move_assignable<hasher>::value &&
-            is_nothrow_move_assignable<key_equal>::value);
-#endif
-    template <class _InputIterator>
-        void __assign_unique(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        void __assign_multi(_InputIterator __first, _InputIterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT
-    {
-        return std::min<size_type>(
-            __node_traits::max_size(__node_alloc()),
-            numeric_limits<difference_type >::max()
-        );
-    }
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    __next_pointer __node_insert_multi_prepare(size_t __cp_hash,
-                                               value_type& __cp_val);
-    _LIBCPP_INLINE_VISIBILITY
-    void __node_insert_multi_perform(__node_pointer __cp,
-                                     __next_pointer __pn) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __next_pointer __node_insert_unique_prepare(size_t __nd_hash,
-                                                value_type& __nd_val);
-    _LIBCPP_INLINE_VISIBILITY
-    void __node_insert_unique_perform(__node_pointer __ptr) _NOEXCEPT;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator             __node_insert_multi(__node_pointer __nd);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator             __node_insert_multi(const_iterator __p,
-                                             __node_pointer __nd);
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Key, class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique_key_args(_Key const& __k, _Args&&... __args);
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique(_Pp&& __x) {
-      return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x),
-                                          __can_extract_key<_Pp, key_type>());
-    }
-
-    template <class _First, class _Second>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<
-        __can_extract_map_key<_First, key_type, __container_value_type>::value,
-        pair<iterator, bool>
-    >::type __emplace_unique(_First&& __f, _Second&& __s) {
-        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f),
-                                              _VSTD::forward<_Second>(__s));
-    }
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique(_Args&&... __args) {
-      return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) {
-      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x));
-    }
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) {
-      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x));
-    }
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) {
-      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x));
-    }
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __emplace_multi(_Args&&... __args);
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
-
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __insert_unique(__container_value_type&& __x) {
-      return __emplace_unique_key_args(_NodeTypes::__get_key(__x), _VSTD::move(__x));
-    }
-
-    template <class _Pp, class = typename enable_if<
-            !__is_same_uncvref<_Pp, __container_value_type>::value
-        >::type>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __insert_unique(_Pp&& __x) {
-      return __emplace_unique(_VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(_Pp&& __x) {
-      return __emplace_multi(_VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(const_iterator __p, _Pp&& __x) {
-        return __emplace_hint_multi(__p, _VSTD::forward<_Pp>(__x));
-    }
-
-#else  // !defined(_LIBCPP_CXX03_LANG)
-    template <class _Key, class _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique_key_args(_Key const&, _Args& __args);
-
-    iterator __insert_multi(const __container_value_type& __x);
-    iterator __insert_multi(const_iterator __p, const __container_value_type& __x);
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __insert_unique(const __container_value_type& __x) {
-        return __emplace_unique_key_args(_NodeTypes::__get_key(__x), __x);
-    }
-
-#if _LIBCPP_STD_VER > 14
-    template <class _NodeHandle, class _InsertReturnType>
-    _LIBCPP_INLINE_VISIBILITY
-    _InsertReturnType __node_handle_insert_unique(_NodeHandle&& __nh);
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_handle_insert_unique(const_iterator __hint,
-                                         _NodeHandle&& __nh);
-    template <class _Table>
-    _LIBCPP_INLINE_VISIBILITY
-    void __node_handle_merge_unique(_Table& __source);
-
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_handle_insert_multi(_NodeHandle&& __nh);
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_handle_insert_multi(const_iterator __hint, _NodeHandle&& __nh);
-    template <class _Table>
-    _LIBCPP_INLINE_VISIBILITY
-    void __node_handle_merge_multi(_Table& __source);
-
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    _NodeHandle __node_handle_extract(key_type const& __key);
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    _NodeHandle __node_handle_extract(const_iterator __it);
-#endif
-
-    void clear() _NOEXCEPT;
-    void rehash(size_type __n);
-    _LIBCPP_INLINE_VISIBILITY void reserve(size_type __n)
-        {rehash(static_cast<size_type>(ceil(__n / max_load_factor())));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_count() const _NOEXCEPT
-    {
-        return __bucket_list_.get_deleter().size();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT;
-
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        size_type bucket(const _Key& __k) const
-        {
-            _LIBCPP_ASSERT(bucket_count() > 0,
-                "unordered container::bucket(key) called when bucket_count() == 0");
-            return __constrain_hash(hash_function()(__k), bucket_count());
-        }
-
-    template <class _Key>
-        iterator       find(const _Key& __x);
-    template <class _Key>
-        const_iterator find(const _Key& __x) const;
-
-    typedef __hash_node_destructor<__node_allocator> _Dp;
-    typedef unique_ptr<__node, _Dp> __node_holder;
-
-    iterator erase(const_iterator __p);
-    iterator erase(const_iterator __first, const_iterator __last);
-    template <class _Key>
-        size_type __erase_unique(const _Key& __k);
-    template <class _Key>
-        size_type __erase_multi(const _Key& __k);
-    __node_holder remove(const_iterator __p) _NOEXCEPT;
-
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        size_type __count_unique(const _Key& __k) const;
-    template <class _Key>
-        size_type __count_multi(const _Key& __k) const;
-
-    template <class _Key>
-        pair<iterator, iterator>
-        __equal_range_unique(const _Key& __k);
-    template <class _Key>
-        pair<const_iterator, const_iterator>
-        __equal_range_unique(const _Key& __k) const;
-
-    template <class _Key>
-        pair<iterator, iterator>
-        __equal_range_multi(const _Key& __k);
-    template <class _Key>
-        pair<const_iterator, const_iterator>
-        __equal_range_multi(const _Key& __k) const;
-
-    void swap(__hash_table& __u)
-#if _LIBCPP_STD_VER <= 11
-        _NOEXCEPT_DEBUG_(
-            __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
-            && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
-                  || __is_nothrow_swappable<__pointer_allocator>::value)
-            && (!__node_traits::propagate_on_container_swap::value
-                  || __is_nothrow_swappable<__node_allocator>::value)
-            );
-#else
-     _NOEXCEPT_DEBUG_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value);
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_bucket_count() const _NOEXCEPT
-        {return max_size(); }
-    size_type bucket_size(size_type __n) const;
-    _LIBCPP_INLINE_VISIBILITY float load_factor() const _NOEXCEPT
-    {
-        size_type __bc = bucket_count();
-        return __bc != 0 ? (float)size() / __bc : 0.f;
-    }
-    _LIBCPP_INLINE_VISIBILITY void max_load_factor(float __mlf) _NOEXCEPT
-    {
-        _LIBCPP_ASSERT(__mlf > 0,
-            "unordered container::max_load_factor(lf) called with lf <= 0");
-        max_load_factor() = _VSTD::max(__mlf, load_factor());
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator
-    begin(size_type __n)
-    {
-        _LIBCPP_ASSERT(__n < bucket_count(),
-            "unordered container::begin(n) called with n >= bucket_count()");
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        return local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
-#else
-        return local_iterator(__bucket_list_[__n], __n, bucket_count());
-#endif
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator
-    end(size_type __n)
-    {
-        _LIBCPP_ASSERT(__n < bucket_count(),
-            "unordered container::end(n) called with n >= bucket_count()");
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        return local_iterator(nullptr, __n, bucket_count(), this);
-#else
-        return local_iterator(nullptr, __n, bucket_count());
-#endif
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator
-    cbegin(size_type __n) const
-    {
-        _LIBCPP_ASSERT(__n < bucket_count(),
-            "unordered container::cbegin(n) called with n >= bucket_count()");
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        return const_local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
-#else
-        return const_local_iterator(__bucket_list_[__n], __n, bucket_count());
-#endif
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator
-    cend(size_type __n) const
-    {
-        _LIBCPP_ASSERT(__n < bucket_count(),
-            "unordered container::cend(n) called with n >= bucket_count()");
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        return const_local_iterator(nullptr, __n, bucket_count(), this);
-#else
-        return const_local_iterator(nullptr, __n, bucket_count());
-#endif
-    }
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    bool __dereferenceable(const const_iterator* __i) const;
-    bool __decrementable(const const_iterator* __i) const;
-    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
-    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-private:
-    void __rehash(size_type __n);
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class ..._Args>
-    __node_holder __construct_node(_Args&& ...__args);
-
-    template <class _First, class ..._Rest>
-    __node_holder __construct_node_hash(size_t __hash, _First&& __f, _Rest&&... __rest);
-#else // _LIBCPP_CXX03_LANG
-    __node_holder __construct_node(const __container_value_type& __v);
-    __node_holder __construct_node_hash(size_t __hash, const __container_value_type& __v);
-#endif
-
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __hash_table& __u)
-        {__copy_assign_alloc(__u, integral_constant<bool,
-             __node_traits::propagate_on_container_copy_assignment::value>());}
-    void __copy_assign_alloc(const __hash_table& __u, true_type);
-    _LIBCPP_INLINE_VISIBILITY
-        void __copy_assign_alloc(const __hash_table&, false_type) {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    void __move_assign(__hash_table& __u, false_type);
-    void __move_assign(__hash_table& __u, true_type)
-        _NOEXCEPT_(
-            is_nothrow_move_assignable<__node_allocator>::value &&
-            is_nothrow_move_assignable<hasher>::value &&
-            is_nothrow_move_assignable<key_equal>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__hash_table& __u)
-        _NOEXCEPT_(
-            !__node_traits::propagate_on_container_move_assignment::value ||
-            (is_nothrow_move_assignable<__pointer_allocator>::value &&
-             is_nothrow_move_assignable<__node_allocator>::value))
-        {__move_assign_alloc(__u, integral_constant<bool,
-             __node_traits::propagate_on_container_move_assignment::value>());}
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__hash_table& __u, true_type)
-        _NOEXCEPT_(
-            is_nothrow_move_assignable<__pointer_allocator>::value &&
-            is_nothrow_move_assignable<__node_allocator>::value)
-    {
-        __bucket_list_.get_deleter().__alloc() =
-                _VSTD::move(__u.__bucket_list_.get_deleter().__alloc());
-        __node_alloc() = _VSTD::move(__u.__node_alloc());
-    }
-    _LIBCPP_INLINE_VISIBILITY
-        void __move_assign_alloc(__hash_table&, false_type) _NOEXCEPT {}
-#endif // _LIBCPP_CXX03_LANG
-
-    void __deallocate_node(__next_pointer __np) _NOEXCEPT;
-    __next_pointer __detach() _NOEXCEPT;
-
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
-};
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-inline
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table()
-    _NOEXCEPT_(
-        is_nothrow_default_constructible<__bucket_list>::value &&
-        is_nothrow_default_constructible<__first_node>::value &&
-        is_nothrow_default_constructible<__node_allocator>::value &&
-        is_nothrow_default_constructible<hasher>::value &&
-        is_nothrow_default_constructible<key_equal>::value)
-    : __p2_(0),
-      __p3_(1.0f)
-{
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-inline
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
-                                                       const key_equal& __eql)
-    : __bucket_list_(nullptr, __bucket_list_deleter()),
-      __p1_(),
-      __p2_(0, __hf),
-      __p3_(1.0f, __eql)
-{
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
-                                                       const key_equal& __eql,
-                                                       const allocator_type& __a)
-    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
-      __p1_(__second_tag(), __node_allocator(__a)),
-      __p2_(0, __hf),
-      __p3_(1.0f, __eql)
-{
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const allocator_type& __a)
-    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
-      __p1_(__second_tag(), __node_allocator(__a)),
-      __p2_(0),
-      __p3_(1.0f)
-{
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u)
-    : __bucket_list_(nullptr,
-          __bucket_list_deleter(allocator_traits<__pointer_allocator>::
-              select_on_container_copy_construction(
-                  __u.__bucket_list_.get_deleter().__alloc()), 0)),
-      __p1_(__second_tag(), allocator_traits<__node_allocator>::
-          select_on_container_copy_construction(__u.__node_alloc())),
-      __p2_(0, __u.hash_function()),
-      __p3_(__u.__p3_)
-{
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u,
-                                                       const allocator_type& __a)
-    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
-      __p1_(__second_tag(), __node_allocator(__a)),
-      __p2_(0, __u.hash_function()),
-      __p3_(__u.__p3_)
-{
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u)
-        _NOEXCEPT_(
-            is_nothrow_move_constructible<__bucket_list>::value &&
-            is_nothrow_move_constructible<__first_node>::value &&
-            is_nothrow_move_constructible<__node_allocator>::value &&
-            is_nothrow_move_constructible<hasher>::value &&
-            is_nothrow_move_constructible<key_equal>::value)
-    : __bucket_list_(_VSTD::move(__u.__bucket_list_)),
-      __p1_(_VSTD::move(__u.__p1_)),
-      __p2_(_VSTD::move(__u.__p2_)),
-      __p3_(_VSTD::move(__u.__p3_))
-{
-    if (size() > 0)
-    {
-        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
-            __p1_.first().__ptr();
-        __u.__p1_.first().__next_ = nullptr;
-        __u.size() = 0;
-    }
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u,
-                                                       const allocator_type& __a)
-    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
-      __p1_(__second_tag(), __node_allocator(__a)),
-      __p2_(0, _VSTD::move(__u.hash_function())),
-      __p3_(_VSTD::move(__u.__p3_))
-{
-    if (__a == allocator_type(__u.__node_alloc()))
-    {
-        __bucket_list_.reset(__u.__bucket_list_.release());
-        __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
-        __u.__bucket_list_.get_deleter().size() = 0;
-        if (__u.size() > 0)
-        {
-            __p1_.first().__next_ = __u.__p1_.first().__next_;
-            __u.__p1_.first().__next_ = nullptr;
-            __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
-                __p1_.first().__ptr();
-            size() = __u.size();
-            __u.size() = 0;
-        }
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::~__hash_table()
-{
-#if defined(_LIBCPP_CXX03_LANG)
-    static_assert((is_copy_constructible<key_equal>::value),
-                 "Predicate must be copy-constructible.");
-    static_assert((is_copy_constructible<hasher>::value),
-                 "Hasher must be copy-constructible.");
-#endif
-
-    __deallocate_node(__p1_.first().__next_);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__erase_c(this);
-#endif
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__copy_assign_alloc(
-        const __hash_table& __u, true_type)
-{
-    if (__node_alloc() != __u.__node_alloc())
-    {
-        clear();
-        __bucket_list_.reset();
-        __bucket_list_.get_deleter().size() = 0;
-    }
-    __bucket_list_.get_deleter().__alloc() = __u.__bucket_list_.get_deleter().__alloc();
-    __node_alloc() = __u.__node_alloc();
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>&
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(const __hash_table& __u)
-{
-    if (this != &__u)
-    {
-        __copy_assign_alloc(__u);
-        hash_function() = __u.hash_function();
-        key_eq() = __u.key_eq();
-        max_load_factor() = __u.max_load_factor();
-        __assign_multi(__u.begin(), __u.end());
-    }
-    return *this;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__deallocate_node(__next_pointer __np)
-    _NOEXCEPT
-{
-    __node_allocator& __na = __node_alloc();
-    while (__np != nullptr)
-    {
-        __next_pointer __next = __np->__next_;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __c_node* __c = __get_db()->__find_c_and_lock(this);
-        for (__i_node** __p = __c->end_; __p != __c->beg_; )
-        {
-            --__p;
-            iterator* __i = static_cast<iterator*>((*__p)->__i_);
-            if (__i->__node_ == __np)
-            {
-                (*__p)->__c_ = nullptr;
-                if (--__c->end_ != __p)
-                    memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
-            }
-        }
-        __get_db()->unlock();
-#endif
-        __node_pointer __real_np = __np->__upcast();
-        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__real_np->__value_));
-        __node_traits::deallocate(__na, __real_np, 1);
-        __np = __next;
-    }
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__detach() _NOEXCEPT
-{
-    size_type __bc = bucket_count();
-    for (size_type __i = 0; __i < __bc; ++__i)
-        __bucket_list_[__i] = nullptr;
-    size() = 0;
-    __next_pointer __cache = __p1_.first().__next_;
-    __p1_.first().__next_ = nullptr;
-    return __cache;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
-        __hash_table& __u, true_type)
-    _NOEXCEPT_(
-        is_nothrow_move_assignable<__node_allocator>::value &&
-        is_nothrow_move_assignable<hasher>::value &&
-        is_nothrow_move_assignable<key_equal>::value)
-{
-    clear();
-    __bucket_list_.reset(__u.__bucket_list_.release());
-    __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
-    __u.__bucket_list_.get_deleter().size() = 0;
-    __move_assign_alloc(__u);
-    size() = __u.size();
-    hash_function() = _VSTD::move(__u.hash_function());
-    max_load_factor() = __u.max_load_factor();
-    key_eq() = _VSTD::move(__u.key_eq());
-    __p1_.first().__next_ = __u.__p1_.first().__next_;
-    if (size() > 0)
-    {
-        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
-            __p1_.first().__ptr();
-        __u.__p1_.first().__next_ = nullptr;
-        __u.size() = 0;
-    }
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
-        __hash_table& __u, false_type)
-{
-    if (__node_alloc() == __u.__node_alloc())
-        __move_assign(__u, true_type());
-    else
-    {
-        hash_function() = _VSTD::move(__u.hash_function());
-        key_eq() = _VSTD::move(__u.key_eq());
-        max_load_factor() = __u.max_load_factor();
-        if (bucket_count() != 0)
-        {
-            __next_pointer __cache = __detach();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-            try
-            {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-                const_iterator __i = __u.begin();
-                while (__cache != nullptr && __u.size() != 0)
-                {
-                    __cache->__upcast()->__value_ =
-                        _VSTD::move(__u.remove(__i++)->__value_);
-                    __next_pointer __next = __cache->__next_;
-                    __node_insert_multi(__cache->__upcast());
-                    __cache = __next;
-                }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-            }
-            catch (...)
-            {
-                __deallocate_node(__cache);
-                throw;
-            }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            __deallocate_node(__cache);
-        }
-        const_iterator __i = __u.begin();
-        while (__u.size() != 0)
-        {
-            __node_holder __h = __construct_node(_NodeTypes::__move(__u.remove(__i++)->__value_));
-            __node_insert_multi(__h.get());
-            __h.release();
-        }
-    }
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-inline
-__hash_table<_Tp, _Hash, _Equal, _Alloc>&
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(__hash_table&& __u)
-    _NOEXCEPT_(
-        __node_traits::propagate_on_container_move_assignment::value &&
-        is_nothrow_move_assignable<__node_allocator>::value &&
-        is_nothrow_move_assignable<hasher>::value &&
-        is_nothrow_move_assignable<key_equal>::value)
-{
-    __move_assign(__u, integral_constant<bool,
-                  __node_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _InputIterator>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_unique(_InputIterator __first,
-                                                          _InputIterator __last)
-{
-    typedef iterator_traits<_InputIterator> _ITraits;
-    typedef typename _ITraits::value_type _ItValueType;
-    static_assert((is_same<_ItValueType, __container_value_type>::value),
-                  "__assign_unique may only be called with the containers value type");
-
-    if (bucket_count() != 0)
-    {
-        __next_pointer __cache = __detach();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (; __cache != nullptr && __first != __last; ++__first)
-            {
-                __cache->__upcast()->__value_ = *__first;
-                __next_pointer __next = __cache->__next_;
-                __node_insert_unique(__cache->__upcast());
-                __cache = __next;
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __deallocate_node(__cache);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __deallocate_node(__cache);
-    }
-    for (; __first != __last; ++__first)
-        __insert_unique(*__first);
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _InputIterator>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_multi(_InputIterator __first,
-                                                         _InputIterator __last)
-{
-    typedef iterator_traits<_InputIterator> _ITraits;
-    typedef typename _ITraits::value_type _ItValueType;
-    static_assert((is_same<_ItValueType, __container_value_type>::value ||
-                  is_same<_ItValueType, __node_value_type>::value),
-                  "__assign_multi may only be called with the containers value type"
-                  " or the nodes value type");
-    if (bucket_count() != 0)
-    {
-        __next_pointer __cache = __detach();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (; __cache != nullptr && __first != __last; ++__first)
-            {
-                __cache->__upcast()->__value_ = *__first;
-                __next_pointer __next = __cache->__next_;
-                __node_insert_multi(__cache->__upcast());
-                __cache = __next;
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __deallocate_node(__cache);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __deallocate_node(__cache);
-    }
-    for (; __first != __last; ++__first)
-        __insert_multi(_NodeTypes::__get_value(*__first));
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-inline
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() _NOEXCEPT
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator(__p1_.first().__next_, this);
-#else
-    return iterator(__p1_.first().__next_);
-#endif
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-inline
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() _NOEXCEPT
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator(nullptr, this);
-#else
-    return iterator(nullptr);
-#endif
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-inline
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() const _NOEXCEPT
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return const_iterator(__p1_.first().__next_, this);
-#else
-    return const_iterator(__p1_.first().__next_);
-#endif
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-inline
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() const _NOEXCEPT
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return const_iterator(nullptr, this);
-#else
-    return const_iterator(nullptr);
-#endif
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::clear() _NOEXCEPT
-{
-    if (size() > 0)
-    {
-        __deallocate_node(__p1_.first().__next_);
-        __p1_.first().__next_ = nullptr;
-        size_type __bc = bucket_count();
-        for (size_type __i = 0; __i < __bc; ++__i)
-            __bucket_list_[__i] = nullptr;
-        size() = 0;
-    }
-}
-
-
-// Prepare the container for an insertion of the value __value with the hash
-// __hash. This does a lookup into the container to see if __value is already
-// present, and performs a rehash if necessary. Returns a pointer to the
-// existing element if it exists, otherwise nullptr.
-//
-// Note that this function does forward exceptions if key_eq() throws, and never
-// mutates __value or actually inserts into the map.
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-_LIBCPP_INLINE_VISIBILITY
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique_prepare(
-    size_t __hash, value_type& __value)
-{
-    size_type __bc = bucket_count();
-
-    if (__bc != 0)
-    {
-        size_t __chash = __constrain_hash(__hash, __bc);
-        __next_pointer __ndptr = __bucket_list_[__chash];
-        if (__ndptr != nullptr)
-        {
-            for (__ndptr = __ndptr->__next_; __ndptr != nullptr &&
-                                             __constrain_hash(__ndptr->__hash(), __bc) == __chash;
-                                                     __ndptr = __ndptr->__next_)
-            {
-                if (key_eq()(__ndptr->__upcast()->__value_, __value))
-                    return __ndptr;
-            }
-        }
-    }
-    if (size()+1 > __bc * max_load_factor() || __bc == 0)
-    {
-        rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
-                                     size_type(ceil(float(size() + 1) / max_load_factor()))));
-    }
-    return nullptr;
-}
-
-// Insert the node __nd into the container by pushing it into the right bucket,
-// and updating size(). Assumes that __nd->__hash is up-to-date, and that
-// rehashing has already occurred and that no element with the same key exists
-// in the map.
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-_LIBCPP_INLINE_VISIBILITY
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique_perform(
-    __node_pointer __nd) _NOEXCEPT
-{
-    size_type __bc = bucket_count();
-    size_t __chash = __constrain_hash(__nd->__hash(), __bc);
-    // insert_after __bucket_list_[__chash], or __first_node if bucket is null
-    __next_pointer __pn = __bucket_list_[__chash];
-    if (__pn == nullptr)
-    {
-        __pn =__p1_.first().__ptr();
-        __nd->__next_ = __pn->__next_;
-        __pn->__next_ = __nd->__ptr();
-        // fix up __bucket_list_
-        __bucket_list_[__chash] = __pn;
-        if (__nd->__next_ != nullptr)
-            __bucket_list_[__constrain_hash(__nd->__next_->__hash(), __bc)] = __nd->__ptr();
-    }
-    else
-    {
-        __nd->__next_ = __pn->__next_;
-        __pn->__next_ = __nd->__ptr();
-    }
-    ++size();
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique(__node_pointer __nd)
-{
-    __nd->__hash_ = hash_function()(__nd->__value_);
-    __next_pointer __existing_node =
-        __node_insert_unique_prepare(__nd->__hash(), __nd->__value_);
-
-    // Insert the node, unless it already exists in the container.
-    bool __inserted = false;
-    if (__existing_node == nullptr)
-    {
-        __node_insert_unique_perform(__nd);
-        __existing_node = __nd->__ptr();
-        __inserted = true;
-    }
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return pair<iterator, bool>(iterator(__existing_node, this), __inserted);
-#else
-    return pair<iterator, bool>(iterator(__existing_node), __inserted);
-#endif
-}
-
-// Prepare the container for an insertion of the value __cp_val with the hash
-// __cp_hash. This does a lookup into the container to see if __cp_value is
-// already present, and performs a rehash if necessary. Returns a pointer to the
-// last occurance of __cp_val in the map.
-//
-// Note that this function does forward exceptions if key_eq() throws, and never
-// mutates __value or actually inserts into the map.
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi_prepare(
-    size_t __cp_hash, value_type& __cp_val)
-{
-    size_type __bc = bucket_count();
-    if (size()+1 > __bc * max_load_factor() || __bc == 0)
-    {
-        rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
-                       size_type(ceil(float(size() + 1) / max_load_factor()))));
-        __bc = bucket_count();
-    }
-    size_t __chash = __constrain_hash(__cp_hash, __bc);
-    __next_pointer __pn = __bucket_list_[__chash];
-    if (__pn != nullptr)
-    {
-        for (bool __found = false; __pn->__next_ != nullptr &&
-                                   __constrain_hash(__pn->__next_->__hash(), __bc) == __chash;
-                                                           __pn = __pn->__next_)
-        {
-            //      __found    key_eq()     action
-            //      false       false       loop
-            //      true        true        loop
-            //      false       true        set __found to true
-            //      true        false       break
-            if (__found != (__pn->__next_->__hash() == __cp_hash &&
-                            key_eq()(__pn->__next_->__upcast()->__value_, __cp_val)))
-            {
-                if (!__found)
-                    __found = true;
-                else
-                    break;
-            }
-        }
-    }
-    return __pn;
-}
-
-// Insert the node __cp into the container after __pn (which is the last node in
-// the bucket that compares equal to __cp). Rehashing, and checking for
-// uniqueness has already been performed (in __node_insert_multi_prepare), so
-// all we need to do is update the bucket and size(). Assumes that __cp->__hash
-// is up-to-date.
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi_perform(
-    __node_pointer __cp, __next_pointer __pn) _NOEXCEPT
-{
-    size_type __bc = bucket_count();
-    size_t __chash = __constrain_hash(__cp->__hash_, __bc);
-    if (__pn == nullptr)
-    {
-        __pn =__p1_.first().__ptr();
-        __cp->__next_ = __pn->__next_;
-        __pn->__next_ = __cp->__ptr();
-        // fix up __bucket_list_
-        __bucket_list_[__chash] = __pn;
-        if (__cp->__next_ != nullptr)
-            __bucket_list_[__constrain_hash(__cp->__next_->__hash(), __bc)]
-                = __cp->__ptr();
-    }
-    else
-    {
-        __cp->__next_ = __pn->__next_;
-        __pn->__next_ = __cp->__ptr();
-        if (__cp->__next_ != nullptr)
-        {
-            size_t __nhash = __constrain_hash(__cp->__next_->__hash(), __bc);
-            if (__nhash != __chash)
-                __bucket_list_[__nhash] = __cp->__ptr();
-        }
-    }
-    ++size();
-}
-
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(__node_pointer __cp)
-{
-    __cp->__hash_ = hash_function()(__cp->__value_);
-    __next_pointer __pn = __node_insert_multi_prepare(__cp->__hash(), __cp->__value_);
-    __node_insert_multi_perform(__cp, __pn);
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator(__cp->__ptr(), this);
-#else
-    return iterator(__cp->__ptr());
-#endif
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(
-        const_iterator __p, __node_pointer __cp)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
-        " referring to this unordered container");
-#endif
-    if (__p != end() && key_eq()(*__p, __cp->__value_))
-    {
-        __next_pointer __np = __p.__node_;
-        __cp->__hash_ = __np->__hash();
-        size_type __bc = bucket_count();
-        if (size()+1 > __bc * max_load_factor() || __bc == 0)
-        {
-            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
-                           size_type(ceil(float(size() + 1) / max_load_factor()))));
-            __bc = bucket_count();
-        }
-        size_t __chash = __constrain_hash(__cp->__hash_, __bc);
-        __next_pointer __pp = __bucket_list_[__chash];
-        while (__pp->__next_ != __np)
-            __pp = __pp->__next_;
-        __cp->__next_ = __np;
-        __pp->__next_ = static_cast<__next_pointer>(__cp);
-        ++size();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        return iterator(static_cast<__next_pointer>(__cp), this);
-#else
-        return iterator(static_cast<__next_pointer>(__cp));
-#endif
-    }
-    return __node_insert_multi(__cp);
-}
-
-
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key, class ..._Args>
-pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args)
-#else
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key, class _Args>
-pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_key_args(_Key const& __k, _Args& __args)
-#endif
-{
-
-    size_t __hash = hash_function()(__k);
-    size_type __bc = bucket_count();
-    bool __inserted = false;
-    __next_pointer __nd;
-    size_t __chash;
-    if (__bc != 0)
-    {
-        __chash = __constrain_hash(__hash, __bc);
-        __nd = __bucket_list_[__chash];
-        if (__nd != nullptr)
-        {
-            for (__nd = __nd->__next_; __nd != nullptr &&
-                (__nd->__hash() == __hash || __constrain_hash(__nd->__hash(), __bc) == __chash);
-                                                           __nd = __nd->__next_)
-            {
-                if (key_eq()(__nd->__upcast()->__value_, __k))
-                    goto __done;
-            }
-        }
-    }
-    {
-#ifndef _LIBCPP_CXX03_LANG
-        __node_holder __h = __construct_node_hash(__hash, _VSTD::forward<_Args>(__args)...);
-#else
-        __node_holder __h = __construct_node_hash(__hash, __args);
-#endif
-        if (size()+1 > __bc * max_load_factor() || __bc == 0)
-        {
-            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
-                           size_type(ceil(float(size() + 1) / max_load_factor()))));
-            __bc = bucket_count();
-            __chash = __constrain_hash(__hash, __bc);
-        }
-        // insert_after __bucket_list_[__chash], or __first_node if bucket is null
-        __next_pointer __pn = __bucket_list_[__chash];
-        if (__pn == nullptr)
-        {
-            __pn = __p1_.first().__ptr();
-            __h->__next_ = __pn->__next_;
-            __pn->__next_ = __h.get()->__ptr();
-            // fix up __bucket_list_
-            __bucket_list_[__chash] = __pn;
-            if (__h->__next_ != nullptr)
-                __bucket_list_[__constrain_hash(__h->__next_->__hash(), __bc)]
-                    = __h.get()->__ptr();
-        }
-        else
-        {
-            __h->__next_ = __pn->__next_;
-            __pn->__next_ = static_cast<__next_pointer>(__h.get());
-        }
-        __nd = static_cast<__next_pointer>(__h.release());
-        // increment size
-        ++size();
-        __inserted = true;
-    }
-__done:
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return pair<iterator, bool>(iterator(__nd, this), __inserted);
-#else
-    return pair<iterator, bool>(iterator(__nd), __inserted);
-#endif
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class... _Args>
-pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_impl(_Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    pair<iterator, bool> __r = __node_insert_unique(__h.get());
-    if (__r.second)
-        __h.release();
-    return __r;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class... _Args>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_multi(_Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    iterator __r = __node_insert_multi(__h.get());
-    __h.release();
-    return __r;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class... _Args>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_hint_multi(
-        const_iterator __p, _Args&&... __args)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
-        " referring to this unordered container");
-#endif
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    iterator __r = __node_insert_multi(__p, __h.get());
-    __h.release();
-    return __r;
-}
-
-#else // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(const __container_value_type& __x)
-{
-    __node_holder __h = __construct_node(__x);
-    iterator __r = __node_insert_multi(__h.get());
-    __h.release();
-    return __r;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__insert_multi(const_iterator __p,
-                                                         const __container_value_type& __x)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "unordered container::insert(const_iterator, lvalue) called with an iterator not"
-        " referring to this unordered container");
-#endif
-    __node_holder __h = __construct_node(__x);
-    iterator __r = __node_insert_multi(__p, __h.get());
-    __h.release();
-    return __r;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _NodeHandle, class _InsertReturnType>
-_LIBCPP_INLINE_VISIBILITY
-_InsertReturnType
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
-    _NodeHandle&& __nh)
-{
-    if (__nh.empty())
-        return _InsertReturnType{end(), false, _NodeHandle()};
-    pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
-    if (__result.second)
-        __nh.__release();
-    return _InsertReturnType{__result.first, __result.second, _VSTD::move(__nh)};
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
-    const_iterator, _NodeHandle&& __nh)
-{
-    if (__nh.empty())
-        return end();
-    pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
-    if (__result.second)
-        __nh.__release();
-    return __result.first;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-_NodeHandle
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_extract(
-    key_type const& __key)
-{
-    iterator __i = find(__key);
-    if (__i == end())
-        return _NodeHandle();
-    return __node_handle_extract<_NodeHandle>(__i);
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-_NodeHandle
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_extract(
-    const_iterator __p)
-{
-    allocator_type __alloc(__node_alloc());
-    return _NodeHandle(remove(__p).release(), __alloc);
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Table>
-_LIBCPP_INLINE_VISIBILITY
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_merge_unique(
-    _Table& __source)
-{
-    static_assert(is_same<__node, typename _Table::__node>::value, "");
-
-    for (typename _Table::iterator __it = __source.begin();
-         __it != __source.end();)
-    {
-        __node_pointer __src_ptr = __it.__node_->__upcast();
-        size_t __hash = hash_function()(__src_ptr->__value_);
-        __next_pointer __existing_node =
-            __node_insert_unique_prepare(__hash, __src_ptr->__value_);
-        auto __prev_iter = __it++;
-        if (__existing_node == nullptr)
-        {
-            (void)__source.remove(__prev_iter).release();
-            __src_ptr->__hash_ = __hash;
-            __node_insert_unique_perform(__src_ptr);
-        }
-    }
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
-    _NodeHandle&& __nh)
-{
-    if (__nh.empty())
-        return end();
-    iterator __result = __node_insert_multi(__nh.__ptr_);
-    __nh.__release();
-    return __result;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
-    const_iterator __hint, _NodeHandle&& __nh)
-{
-    if (__nh.empty())
-        return end();
-    iterator __result = __node_insert_multi(__hint, __nh.__ptr_);
-    __nh.__release();
-    return __result;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Table>
-_LIBCPP_INLINE_VISIBILITY
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_merge_multi(
-    _Table& __source)
-{
-    static_assert(is_same<typename _Table::__node, __node>::value, "");
-
-    for (typename _Table::iterator __it = __source.begin();
-         __it != __source.end();)
-    {
-        __node_pointer __src_ptr = __it.__node_->__upcast();
-        size_t __src_hash = hash_function()(__src_ptr->__value_);
-        __next_pointer __pn =
-            __node_insert_multi_prepare(__src_hash, __src_ptr->__value_);
-        (void)__source.remove(__it++).release();
-        __src_ptr->__hash_ = __src_hash;
-        __node_insert_multi_perform(__src_ptr, __pn);
-    }
-}
-#endif  // _LIBCPP_STD_VER > 14
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::rehash(size_type __n)
-{
-    if (__n == 1)
-        __n = 2;
-    else if (__n & (__n - 1))
-        __n = __next_prime(__n);
-    size_type __bc = bucket_count();
-    if (__n > __bc)
-        __rehash(__n);
-    else if (__n < __bc)
-    {
-        __n = _VSTD::max<size_type>
-              (
-                  __n,
-                  __is_hash_power2(__bc) ? __next_hash_pow2(size_t(ceil(float(size()) / max_load_factor()))) :
-                                           __next_prime(size_t(ceil(float(size()) / max_load_factor())))
-              );
-        if (__n < __bc)
-            __rehash(__n);
-    }
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__rehash(size_type __nbc)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__invalidate_all(this);
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-    __pointer_allocator& __npa = __bucket_list_.get_deleter().__alloc();
-    __bucket_list_.reset(__nbc > 0 ?
-                      __pointer_alloc_traits::allocate(__npa, __nbc) : nullptr);
-    __bucket_list_.get_deleter().size() = __nbc;
-    if (__nbc > 0)
-    {
-        for (size_type __i = 0; __i < __nbc; ++__i)
-            __bucket_list_[__i] = nullptr;
-        __next_pointer __pp = __p1_.first().__ptr();
-        __next_pointer __cp = __pp->__next_;
-        if (__cp != nullptr)
-        {
-            size_type __chash = __constrain_hash(__cp->__hash(), __nbc);
-            __bucket_list_[__chash] = __pp;
-            size_type __phash = __chash;
-            for (__pp = __cp, __cp = __cp->__next_; __cp != nullptr;
-                                                           __cp = __pp->__next_)
-            {
-                __chash = __constrain_hash(__cp->__hash(), __nbc);
-                if (__chash == __phash)
-                    __pp = __cp;
-                else
-                {
-                    if (__bucket_list_[__chash] == nullptr)
-                    {
-                        __bucket_list_[__chash] = __pp;
-                        __pp = __cp;
-                        __phash = __chash;
-                    }
-                    else
-                    {
-                        __next_pointer __np = __cp;
-                        for (; __np->__next_ != nullptr &&
-                               key_eq()(__cp->__upcast()->__value_,
-                                        __np->__next_->__upcast()->__value_);
-                                                           __np = __np->__next_)
-                            ;
-                        __pp->__next_ = __np->__next_;
-                        __np->__next_ = __bucket_list_[__chash]->__next_;
-                        __bucket_list_[__chash]->__next_ = __cp;
-
-                    }
-                }
-            }
-        }
-    }
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k)
-{
-    size_t __hash = hash_function()(__k);
-    size_type __bc = bucket_count();
-    if (__bc != 0)
-    {
-        size_t __chash = __constrain_hash(__hash, __bc);
-        __next_pointer __nd = __bucket_list_[__chash];
-        if (__nd != nullptr)
-        {
-            for (__nd = __nd->__next_; __nd != nullptr &&
-                (__nd->__hash() == __hash
-                  || __constrain_hash(__nd->__hash(), __bc) == __chash);
-                                                           __nd = __nd->__next_)
-            {
-                if ((__nd->__hash() == __hash)
-                    && key_eq()(__nd->__upcast()->__value_, __k))
-#if _LIBCPP_DEBUG_LEVEL >= 2
-                    return iterator(__nd, this);
-#else
-                    return iterator(__nd);
-#endif
-            }
-        }
-    }
-    return end();
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k) const
-{
-    size_t __hash = hash_function()(__k);
-    size_type __bc = bucket_count();
-    if (__bc != 0)
-    {
-        size_t __chash = __constrain_hash(__hash, __bc);
-        __next_pointer __nd = __bucket_list_[__chash];
-        if (__nd != nullptr)
-        {
-            for (__nd = __nd->__next_; __nd != nullptr &&
-                (__hash == __nd->__hash()
-                    || __constrain_hash(__nd->__hash(), __bc) == __chash);
-                                                           __nd = __nd->__next_)
-            {
-                if ((__nd->__hash() == __hash)
-                    && key_eq()(__nd->__upcast()->__value_, __k))
-#if _LIBCPP_DEBUG_LEVEL >= 2
-                    return const_iterator(__nd, this);
-#else
-                    return const_iterator(__nd);
-#endif
-            }
-        }
-
-    }
-    return end();
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class ..._Args>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(_Args&& ...__args)
-{
-    static_assert(!__is_hash_value_type<_Args...>::value,
-                  "Construct cannot be called with a hash value type");
-    __node_allocator& __na = __node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...);
-    __h.get_deleter().__value_constructed = true;
-    __h->__hash_ = hash_function()(__h->__value_);
-    __h->__next_ = nullptr;
-    return __h;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _First, class ..._Rest>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node_hash(
-    size_t __hash, _First&& __f, _Rest&& ...__rest)
-{
-    static_assert(!__is_hash_value_type<_First, _Rest...>::value,
-                  "Construct cannot be called with a hash value type");
-    __node_allocator& __na = __node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_),
-                             _VSTD::forward<_First>(__f),
-                             _VSTD::forward<_Rest>(__rest)...);
-    __h.get_deleter().__value_constructed = true;
-    __h->__hash_ = __hash;
-    __h->__next_ = nullptr;
-    return __h;
-}
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(const __container_value_type& __v)
-{
-    __node_allocator& __na = __node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), __v);
-    __h.get_deleter().__value_constructed = true;
-    __h->__hash_ = hash_function()(__h->__value_);
-    __h->__next_ = nullptr;
-    return _LIBCPP_EXPLICIT_MOVE(__h);  // explicitly moved for C++03
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node_hash(size_t __hash,
-                                                                const __container_value_type& __v)
-{
-    __node_allocator& __na = __node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), __v);
-    __h.get_deleter().__value_constructed = true;
-    __h->__hash_ = __hash;
-    __h->__next_ = nullptr;
-    return _LIBCPP_EXPLICIT_MOVE(__h);  // explicitly moved for C++03
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __p)
-{
-    __next_pointer __np = __p.__node_;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "unordered container erase(iterator) called with an iterator not"
-        " referring to this container");
-    _LIBCPP_ASSERT(__p != end(),
-        "unordered container erase(iterator) called with a non-dereferenceable iterator");
-    iterator __r(__np, this);
-#else
-    iterator __r(__np);
-#endif
-    ++__r;
-    remove(__p);
-    return __r;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __first,
-                                                const_iterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
-        "unodered container::erase(iterator, iterator) called with an iterator not"
-        " referring to this unodered container");
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__last) == this,
-        "unodered container::erase(iterator, iterator) called with an iterator not"
-        " referring to this unodered container");
-#endif
-    for (const_iterator __p = __first; __first != __last; __p = __first)
-    {
-        ++__first;
-        erase(__p);
-    }
-    __next_pointer __np = __last.__node_;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator (__np, this);
-#else
-    return iterator (__np);
-#endif
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_unique(const _Key& __k)
-{
-    iterator __i = find(__k);
-    if (__i == end())
-        return 0;
-    erase(__i);
-    return 1;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_multi(const _Key& __k)
-{
-    size_type __r = 0;
-    iterator __i = find(__k);
-    if (__i != end())
-    {
-        iterator __e = end();
-        do
-        {
-            erase(__i++);
-            ++__r;
-        } while (__i != __e && key_eq()(*__i, __k));
-    }
-    return __r;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::remove(const_iterator __p) _NOEXCEPT
-{
-    // current node
-    __next_pointer __cn = __p.__node_;
-    size_type __bc = bucket_count();
-    size_t __chash = __constrain_hash(__cn->__hash(), __bc);
-    // find previous node
-    __next_pointer __pn = __bucket_list_[__chash];
-    for (; __pn->__next_ != __cn; __pn = __pn->__next_)
-        ;
-    // Fix up __bucket_list_
-        // if __pn is not in same bucket (before begin is not in same bucket) &&
-        //    if __cn->__next_ is not in same bucket (nullptr is not in same bucket)
-    if (__pn == __p1_.first().__ptr()
-            || __constrain_hash(__pn->__hash(), __bc) != __chash)
-    {
-        if (__cn->__next_ == nullptr
-            || __constrain_hash(__cn->__next_->__hash(), __bc) != __chash)
-            __bucket_list_[__chash] = nullptr;
-    }
-        // if __cn->__next_ is not in same bucket (nullptr is in same bucket)
-    if (__cn->__next_ != nullptr)
-    {
-        size_t __nhash = __constrain_hash(__cn->__next_->__hash(), __bc);
-        if (__nhash != __chash)
-            __bucket_list_[__nhash] = __pn;
-    }
-    // remove __cn
-    __pn->__next_ = __cn->__next_;
-    __cn->__next_ = nullptr;
-    --size();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __c_node* __c = __get_db()->__find_c_and_lock(this);
-    for (__i_node** __dp = __c->end_; __dp != __c->beg_; )
-    {
-        --__dp;
-        iterator* __i = static_cast<iterator*>((*__dp)->__i_);
-        if (__i->__node_ == __cn)
-        {
-            (*__dp)->__c_ = nullptr;
-            if (--__c->end_ != __dp)
-                memmove(__dp, __dp+1, (__c->end_ - __dp)*sizeof(__i_node*));
-        }
-    }
-    __get_db()->unlock();
-#endif
-    return __node_holder(__cn->__upcast(), _Dp(__node_alloc(), true));
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-inline
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_unique(const _Key& __k) const
-{
-    return static_cast<size_type>(find(__k) != end());
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_multi(const _Key& __k) const
-{
-    size_type __r = 0;
-    const_iterator __i = find(__k);
-    if (__i != end())
-    {
-        const_iterator __e = end();
-        do
-        {
-            ++__i;
-            ++__r;
-        } while (__i != __e && key_eq()(*__i, __k));
-    }
-    return __r;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
-     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
-        const _Key& __k)
-{
-    iterator __i = find(__k);
-    iterator __j = __i;
-    if (__i != end())
-        ++__j;
-    return pair<iterator, iterator>(__i, __j);
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
-     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
-        const _Key& __k) const
-{
-    const_iterator __i = find(__k);
-    const_iterator __j = __i;
-    if (__i != end())
-        ++__j;
-    return pair<const_iterator, const_iterator>(__i, __j);
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
-     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
-        const _Key& __k)
-{
-    iterator __i = find(__k);
-    iterator __j = __i;
-    if (__i != end())
-    {
-        iterator __e = end();
-        do
-        {
-            ++__j;
-        } while (__j != __e && key_eq()(*__j, __k));
-    }
-    return pair<iterator, iterator>(__i, __j);
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-template <class _Key>
-pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
-     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
-        const _Key& __k) const
-{
-    const_iterator __i = find(__k);
-    const_iterator __j = __i;
-    if (__i != end())
-    {
-        const_iterator __e = end();
-        do
-        {
-            ++__j;
-        } while (__j != __e && key_eq()(*__j, __k));
-    }
-    return pair<const_iterator, const_iterator>(__i, __j);
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-void
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::swap(__hash_table& __u)
-#if _LIBCPP_STD_VER <= 11
-    _NOEXCEPT_DEBUG_(
-        __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
-        && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
-              || __is_nothrow_swappable<__pointer_allocator>::value)
-        && (!__node_traits::propagate_on_container_swap::value
-              || __is_nothrow_swappable<__node_allocator>::value)
-            )
-#else
-  _NOEXCEPT_DEBUG_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value)
-#endif
-{
-    _LIBCPP_ASSERT(__node_traits::propagate_on_container_swap::value ||
-                   this->__node_alloc() == __u.__node_alloc(),
-                   "list::swap: Either propagate_on_container_swap must be true"
-                   " or the allocators must compare equal");
-    {
-    __node_pointer_pointer __npp = __bucket_list_.release();
-    __bucket_list_.reset(__u.__bucket_list_.release());
-    __u.__bucket_list_.reset(__npp);
-    }
-    _VSTD::swap(__bucket_list_.get_deleter().size(), __u.__bucket_list_.get_deleter().size());
-    __swap_allocator(__bucket_list_.get_deleter().__alloc(),
-             __u.__bucket_list_.get_deleter().__alloc());
-    __swap_allocator(__node_alloc(), __u.__node_alloc());
-    _VSTD::swap(__p1_.first().__next_, __u.__p1_.first().__next_);
-    __p2_.swap(__u.__p2_);
-    __p3_.swap(__u.__p3_);
-    if (size() > 0)
-        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
-            __p1_.first().__ptr();
-    if (__u.size() > 0)
-        __u.__bucket_list_[__constrain_hash(__u.__p1_.first().__next_->__hash(), __u.bucket_count())] =
-            __u.__p1_.first().__ptr();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::bucket_size(size_type __n) const
-{
-    _LIBCPP_ASSERT(__n < bucket_count(),
-        "unordered container::bucket_size(n) called with n >= bucket_count()");
-    __next_pointer __np = __bucket_list_[__n];
-    size_type __bc = bucket_count();
-    size_type __r = 0;
-    if (__np != nullptr)
-    {
-        for (__np = __np->__next_; __np != nullptr &&
-                                   __constrain_hash(__np->__hash(), __bc) == __n;
-                                                    __np = __np->__next_, ++__r)
-            ;
-    }
-    return __r;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__hash_table<_Tp, _Hash, _Equal, _Alloc>& __x,
-     __hash_table<_Tp, _Hash, _Equal, _Alloc>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-bool
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__dereferenceable(const const_iterator* __i) const
-{
-    return __i->__node_ != nullptr;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-bool
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__decrementable(const const_iterator*) const
-{
-    return false;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-bool
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__addable(const const_iterator*, ptrdiff_t) const
-{
-    return false;
-}
-
-template <class _Tp, class _Hash, class _Equal, class _Alloc>
-bool
-__hash_table<_Tp, _Hash, _Equal, _Alloc>::__subscriptable(const const_iterator*, ptrdiff_t) const
-{
-    return false;
-}
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP__HASH_TABLE
diff --git a/lib/libcxx/include/__libcpp_version b/lib/libcxx/include/__libcpp_version
deleted file mode 100644
index e002b3628b3..00000000000
--- a/lib/libcxx/include/__libcpp_version
+++ /dev/null
@@ -1 +0,0 @@
-8000
diff --git a/lib/libcxx/include/__locale b/lib/libcxx/include/__locale
deleted file mode 100644
index af5e5d02e83..00000000000
--- a/lib/libcxx/include/__locale
+++ /dev/null
@@ -1,1523 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___LOCALE
-#define _LIBCPP___LOCALE
-
-#include <__config>
-#include <string>
-#include <memory>
-#include <utility>
-#include <mutex>
-#include <cstdint>
-#include <cctype>
-#include <locale.h>
-#if defined(_LIBCPP_MSVCRT_LIKE)
-# include <support/win32/locale_win32.h>
-#elif defined(_AIX)
-# include <support/ibm/xlocale.h>
-#elif defined(__ANDROID__)
-# include <support/android/locale_bionic.h>
-#elif defined(__sun__)
-# include <xlocale.h>
-# include <support/solaris/xlocale.h>
-#elif defined(_NEWLIB_VERSION) || defined(__OpenBSD__)
-# include <support/newlib/xlocale.h>
-#elif (defined(__APPLE__)      || defined(__FreeBSD__) \
-    || defined(__EMSCRIPTEN__) || defined(__IBMCPP__))
-# include <xlocale.h>
-#elif defined(__Fuchsia__)
-# include <support/fuchsia/xlocale.h>
-#elif defined(_LIBCPP_HAS_MUSL_LIBC)
-# include <support/musl/xlocale.h>
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if !defined(_LIBCPP_LOCALE__L_EXTENSIONS)
-struct __libcpp_locale_guard {
-  _LIBCPP_INLINE_VISIBILITY
-  __libcpp_locale_guard(locale_t& __loc) : __old_loc_(uselocale(__loc)) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  ~__libcpp_locale_guard() {
-    if (__old_loc_)
-      uselocale(__old_loc_);
-  }
-
-  locale_t __old_loc_;
-private:
-  __libcpp_locale_guard(__libcpp_locale_guard const&);
-  __libcpp_locale_guard& operator=(__libcpp_locale_guard const&);
-};
-#elif defined(_LIBCPP_MSVCRT_LIKE)
-struct __libcpp_locale_guard {
-    __libcpp_locale_guard(locale_t __l) :
-        __status(_configthreadlocale(_ENABLE_PER_THREAD_LOCALE)),
-        __locale_collate(setlocale(LC_COLLATE, __l.__get_locale())),
-        __locale_ctype(setlocale(LC_CTYPE, __l.__get_locale())),
-        __locale_monetary(setlocale(LC_MONETARY, __l.__get_locale())),
-        __locale_numeric(setlocale(LC_NUMERIC, __l.__get_locale())),
-        __locale_time(setlocale(LC_TIME, __l.__get_locale()))
-        // LC_MESSAGES is not supported on Windows.
-    {}
-    ~__libcpp_locale_guard() {
-        setlocale(LC_COLLATE, __locale_collate);
-        setlocale(LC_CTYPE, __locale_ctype);
-        setlocale(LC_MONETARY, __locale_monetary);
-        setlocale(LC_NUMERIC, __locale_numeric);
-        setlocale(LC_TIME, __locale_time);
-        _configthreadlocale(__status);
-    }
-    int __status;
-    char* __locale_collate;
-    char* __locale_ctype;
-    char* __locale_monetary;
-    char* __locale_numeric;
-    char* __locale_time;
-};
-#endif
-
-
-class _LIBCPP_TYPE_VIS locale;
-
-template <class _Facet>
-_LIBCPP_INLINE_VISIBILITY
-bool
-has_facet(const locale&) _NOEXCEPT;
-
-template <class _Facet>
-_LIBCPP_INLINE_VISIBILITY
-const _Facet&
-use_facet(const locale&);
-
-class _LIBCPP_TYPE_VIS locale
-{
-public:
-    // types:
-    class _LIBCPP_TYPE_VIS facet;
-    class _LIBCPP_TYPE_VIS id;
-
-    typedef int category;
-    _LIBCPP_AVAILABILITY_LOCALE_CATEGORY
-    static const category // values assigned here are for exposition only
-        none     = 0,
-        collate  = LC_COLLATE_MASK,
-        ctype    = LC_CTYPE_MASK,
-        monetary = LC_MONETARY_MASK,
-        numeric  = LC_NUMERIC_MASK,
-        time     = LC_TIME_MASK,
-        messages = LC_MESSAGES_MASK,
-        all = collate | ctype | monetary | numeric | time | messages;
-
-    // construct/copy/destroy:
-    locale()  _NOEXCEPT;
-    locale(const locale&)  _NOEXCEPT;
-    explicit locale(const char*);
-    explicit locale(const string&);
-    locale(const locale&, const char*, category);
-    locale(const locale&, const string&, category);
-    template <class _Facet>
-        _LIBCPP_INLINE_VISIBILITY locale(const locale&, _Facet*);
-    locale(const locale&, const locale&, category);
-
-    ~locale();
-
-    const locale& operator=(const locale&)  _NOEXCEPT;
-
-    template <class _Facet>
-      _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-      locale combine(const locale&) const;
-
-    // locale operations:
-    string name() const;
-    bool operator==(const locale&) const;
-    bool operator!=(const locale& __y) const {return !(*this == __y);}
-    template <class _CharT, class _Traits, class _Allocator>
-      _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-      bool operator()(const basic_string<_CharT, _Traits, _Allocator>&,
-                      const basic_string<_CharT, _Traits, _Allocator>&) const;
-
-    // global locale objects:
-    static locale global(const locale&);
-    static const locale& classic();
-
-private:
-    class __imp;
-    __imp* __locale_;
-
-    void __install_ctor(const locale&, facet*, long);
-    static locale& __global();
-    bool has_facet(id&) const;
-    const facet* use_facet(id&) const;
-
-    template <class _Facet> friend bool has_facet(const locale&)  _NOEXCEPT;
-    template <class _Facet> friend const _Facet& use_facet(const locale&);
-};
-
-class _LIBCPP_TYPE_VIS locale::facet
-    : public __shared_count
-{
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit facet(size_t __refs = 0)
-        : __shared_count(static_cast<long>(__refs)-1) {}
-
-    virtual ~facet();
-
-//    facet(const facet&) = delete;     // effectively done in __shared_count
-//    void operator=(const facet&) = delete;
-private:
-    virtual void __on_zero_shared() _NOEXCEPT;
-};
-
-class _LIBCPP_TYPE_VIS locale::id
-{
-    once_flag      __flag_;
-    int32_t        __id_;
-
-    static int32_t __next_id;
-public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR id() :__id_(0) {}
-private:
-    void __init();
-    void operator=(const id&); // = delete;
-    id(const id&); // = delete;
-public:  // only needed for tests
-    long __get();
-
-    friend class locale;
-    friend class locale::__imp;
-};
-
-template <class _Facet>
-inline _LIBCPP_INLINE_VISIBILITY
-locale::locale(const locale& __other, _Facet* __f)
-{
-    __install_ctor(__other, __f, __f ? __f->id.__get() : 0);
-}
-
-template <class _Facet>
-locale
-locale::combine(const locale& __other) const
-{
-    if (!_VSTD::has_facet<_Facet>(__other))
-        __throw_runtime_error("locale::combine: locale missing facet");
-
-    return locale(*this, &const_cast<_Facet&>(_VSTD::use_facet<_Facet>(__other)));
-}
-
-template <class _Facet>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-has_facet(const locale& __l)  _NOEXCEPT
-{
-    return __l.has_facet(_Facet::id);
-}
-
-template <class _Facet>
-inline _LIBCPP_INLINE_VISIBILITY
-const _Facet&
-use_facet(const locale& __l)
-{
-    return static_cast<const _Facet&>(*__l.use_facet(_Facet::id));
-}
-
-// template <class _CharT> class collate;
-
-template <class _CharT>
-class _LIBCPP_TEMPLATE_VIS collate
-    : public locale::facet
-{
-public:
-    typedef _CharT char_type;
-    typedef basic_string<char_type> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit collate(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    int compare(const char_type* __lo1, const char_type* __hi1,
-                const char_type* __lo2, const char_type* __hi2) const
-    {
-        return do_compare(__lo1, __hi1, __lo2, __hi2);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    string_type transform(const char_type* __lo, const char_type* __hi) const
-    {
-        return do_transform(__lo, __hi);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    long hash(const char_type* __lo, const char_type* __hi) const
-    {
-        return do_hash(__lo, __hi);
-    }
-
-    static locale::id id;
-
-protected:
-    ~collate();
-    virtual int do_compare(const char_type* __lo1, const char_type* __hi1,
-                           const char_type* __lo2, const char_type* __hi2) const;
-    virtual string_type do_transform(const char_type* __lo, const char_type* __hi) const
-        {return string_type(__lo, __hi);}
-    virtual long do_hash(const char_type* __lo, const char_type* __hi) const;
-};
-
-template <class _CharT> locale::id collate<_CharT>::id;
-
-template <class _CharT>
-collate<_CharT>::~collate()
-{
-}
-
-template <class _CharT>
-int
-collate<_CharT>::do_compare(const char_type* __lo1, const char_type* __hi1,
-                            const char_type* __lo2, const char_type* __hi2) const
-{
-    for (; __lo2 != __hi2; ++__lo1, ++__lo2)
-    {
-        if (__lo1 == __hi1 || *__lo1 < *__lo2)
-            return -1;
-        if (*__lo2 < *__lo1)
-            return 1;
-    }
-    return __lo1 != __hi1;
-}
-
-template <class _CharT>
-long
-collate<_CharT>::do_hash(const char_type* __lo, const char_type* __hi) const
-{
-    size_t __h = 0;
-    const size_t __sr = __CHAR_BIT__ * sizeof(size_t) - 8;
-    const size_t __mask = size_t(0xF) << (__sr + 4);
-    for(const char_type* __p = __lo; __p != __hi; ++__p)
-    {
-        __h = (__h << 4) + static_cast<size_t>(*__p);
-        size_t __g = __h & __mask;
-        __h ^= __g | (__g >> __sr);
-    }
-    return static_cast<long>(__h);
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS collate<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS collate<wchar_t>)
-
-// template <class CharT> class collate_byname;
-
-template <class _CharT> class _LIBCPP_TEMPLATE_VIS collate_byname;
-
-template <>
-class _LIBCPP_TYPE_VIS collate_byname<char>
-    : public collate<char>
-{
-    locale_t __l;
-public:
-    typedef char char_type;
-    typedef basic_string<char_type> string_type;
-
-    explicit collate_byname(const char* __n, size_t __refs = 0);
-    explicit collate_byname(const string& __n, size_t __refs = 0);
-
-protected:
-    ~collate_byname();
-    virtual int do_compare(const char_type* __lo1, const char_type* __hi1,
-                           const char_type* __lo2, const char_type* __hi2) const;
-    virtual string_type do_transform(const char_type* __lo, const char_type* __hi) const;
-};
-
-template <>
-class _LIBCPP_TYPE_VIS collate_byname<wchar_t>
-    : public collate<wchar_t>
-{
-    locale_t __l;
-public:
-    typedef wchar_t char_type;
-    typedef basic_string<char_type> string_type;
-
-    explicit collate_byname(const char* __n, size_t __refs = 0);
-    explicit collate_byname(const string& __n, size_t __refs = 0);
-
-protected:
-    ~collate_byname();
-
-    virtual int do_compare(const char_type* __lo1, const char_type* __hi1,
-                           const char_type* __lo2, const char_type* __hi2) const;
-    virtual string_type do_transform(const char_type* __lo, const char_type* __hi) const;
-};
-
-template <class _CharT, class _Traits, class _Allocator>
-bool
-locale::operator()(const basic_string<_CharT, _Traits, _Allocator>& __x,
-                   const basic_string<_CharT, _Traits, _Allocator>& __y) const
-{
-    return _VSTD::use_facet<_VSTD::collate<_CharT> >(*this).compare(
-                                       __x.data(), __x.data() + __x.size(),
-                                       __y.data(), __y.data() + __y.size()) < 0;
-}
-
-// template <class charT> class ctype
-
-class _LIBCPP_TYPE_VIS ctype_base
-{
-public:
-#if defined(__GLIBC__)
-    typedef unsigned short mask;
-    static const mask space  = _ISspace;
-    static const mask print  = _ISprint;
-    static const mask cntrl  = _IScntrl;
-    static const mask upper  = _ISupper;
-    static const mask lower  = _ISlower;
-    static const mask alpha  = _ISalpha;
-    static const mask digit  = _ISdigit;
-    static const mask punct  = _ISpunct;
-    static const mask xdigit = _ISxdigit;
-    static const mask blank  = _ISblank;
-#elif defined(_LIBCPP_MSVCRT_LIKE)
-    typedef unsigned short mask;
-    static const mask space  = _SPACE;
-    static const mask print  = _BLANK|_PUNCT|_ALPHA|_DIGIT;
-    static const mask cntrl  = _CONTROL;
-    static const mask upper  = _UPPER;
-    static const mask lower  = _LOWER;
-    static const mask alpha  = _ALPHA;
-    static const mask digit  = _DIGIT;
-    static const mask punct  = _PUNCT;
-    static const mask xdigit = _HEX;
-    static const mask blank  = _BLANK;
-# define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
-#elif defined(__APPLE__) || defined(__FreeBSD__) || defined(__EMSCRIPTEN__) || defined(__NetBSD__)
-# ifdef __APPLE__
-    typedef __uint32_t mask;
-# elif defined(__FreeBSD__)
-    typedef unsigned long mask;
-# elif defined(__EMSCRIPTEN__) || defined(__NetBSD__)
-    typedef unsigned short mask;
-# endif
-    static const mask space  = _CTYPE_S;
-    static const mask print  = _CTYPE_R;
-    static const mask cntrl  = _CTYPE_C;
-    static const mask upper  = _CTYPE_U;
-    static const mask lower  = _CTYPE_L;
-    static const mask alpha  = _CTYPE_A;
-    static const mask digit  = _CTYPE_D;
-    static const mask punct  = _CTYPE_P;
-    static const mask xdigit = _CTYPE_X;
-
-# if defined(__NetBSD__)
-    static const mask blank  = _CTYPE_BL;
-# else
-    static const mask blank  = _CTYPE_B;
-# endif
-#elif defined(__sun__) || defined(_AIX)
-    typedef unsigned int mask;
-    static const mask space  = _ISSPACE;
-    static const mask print  = _ISPRINT;
-    static const mask cntrl  = _ISCNTRL;
-    static const mask upper  = _ISUPPER;
-    static const mask lower  = _ISLOWER;
-    static const mask alpha  = _ISALPHA;
-    static const mask digit  = _ISDIGIT;
-    static const mask punct  = _ISPUNCT;
-    static const mask xdigit = _ISXDIGIT;
-    static const mask blank  = _ISBLANK;
-#elif defined(_NEWLIB_VERSION)
-    // Same type as Newlib's _ctype_ array in newlib/libc/include/ctype.h.
-    typedef char mask;
-    static const mask space  = _S;
-    static const mask print  = _P | _U | _L | _N | _B;
-    static const mask cntrl  = _C;
-    static const mask upper  = _U;
-    static const mask lower  = _L;
-    static const mask alpha  = _U | _L;
-    static const mask digit  = _N;
-    static const mask punct  = _P;
-    static const mask xdigit = _X | _N;
-    static const mask blank  = _B;
-# define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
-# define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_ALPHA
-# define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_XDIGIT
-#else
-    typedef unsigned long mask;
-    static const mask space  = 1<<0;
-    static const mask print  = 1<<1;
-    static const mask cntrl  = 1<<2;
-    static const mask upper  = 1<<3;
-    static const mask lower  = 1<<4;
-    static const mask alpha  = 1<<5;
-    static const mask digit  = 1<<6;
-    static const mask punct  = 1<<7;
-    static const mask xdigit = 1<<8;
-    static const mask blank  = 1<<9;
-#endif
-    static const mask alnum  = alpha | digit;
-    static const mask graph  = alnum | punct;
-
-    _LIBCPP_INLINE_VISIBILITY ctype_base() {}
-};
-
-template <class _CharT> class _LIBCPP_TEMPLATE_VIS ctype;
-
-template <>
-class _LIBCPP_TYPE_VIS ctype<wchar_t>
-    : public locale::facet,
-      public ctype_base
-{
-public:
-    typedef wchar_t char_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit ctype(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool is(mask __m, char_type __c) const
-    {
-        return do_is(__m, __c);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* is(const char_type* __low, const char_type* __high, mask* __vec) const
-    {
-        return do_is(__low, __high, __vec);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* scan_is(mask __m, const char_type* __low, const char_type* __high) const
-    {
-        return do_scan_is(__m, __low, __high);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* scan_not(mask __m, const char_type* __low, const char_type* __high) const
-    {
-        return do_scan_not(__m, __low, __high);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    char_type toupper(char_type __c) const
-    {
-        return do_toupper(__c);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* toupper(char_type* __low, const char_type* __high) const
-    {
-        return do_toupper(__low, __high);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    char_type tolower(char_type __c) const
-    {
-        return do_tolower(__c);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* tolower(char_type* __low, const char_type* __high) const
-    {
-        return do_tolower(__low, __high);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    char_type widen(char __c) const
-    {
-        return do_widen(__c);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char* widen(const char* __low, const char* __high, char_type* __to) const
-    {
-        return do_widen(__low, __high, __to);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    char narrow(char_type __c, char __dfault) const
-    {
-        return do_narrow(__c, __dfault);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* narrow(const char_type* __low, const char_type* __high, char __dfault, char* __to) const
-    {
-        return do_narrow(__low, __high, __dfault, __to);
-    }
-
-    static locale::id id;
-
-protected:
-    ~ctype();
-    virtual bool do_is(mask __m, char_type __c) const;
-    virtual const char_type* do_is(const char_type* __low, const char_type* __high, mask* __vec) const;
-    virtual const char_type* do_scan_is(mask __m, const char_type* __low, const char_type* __high) const;
-    virtual const char_type* do_scan_not(mask __m, const char_type* __low, const char_type* __high) const;
-    virtual char_type do_toupper(char_type) const;
-    virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
-    virtual char_type do_tolower(char_type) const;
-    virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
-    virtual char_type do_widen(char) const;
-    virtual const char* do_widen(const char* __low, const char* __high, char_type* __dest) const;
-    virtual char do_narrow(char_type, char __dfault) const;
-    virtual const char_type* do_narrow(const char_type* __low, const char_type* __high, char __dfault, char* __dest) const;
-};
-
-template <>
-class _LIBCPP_TYPE_VIS ctype<char>
-    : public locale::facet, public ctype_base
-{
-    const mask* __tab_;
-    bool        __del_;
-public:
-    typedef char char_type;
-
-    explicit ctype(const mask* __tab = 0, bool __del = false, size_t __refs = 0);
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool is(mask __m, char_type __c) const
-    {
-        return isascii(__c) ? (__tab_[static_cast<int>(__c)] & __m) !=0 : false;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* is(const char_type* __low, const char_type* __high, mask* __vec) const
-    {
-        for (; __low != __high; ++__low, ++__vec)
-            *__vec = isascii(*__low) ? __tab_[static_cast<int>(*__low)] : 0;
-        return __low;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* scan_is (mask __m, const char_type* __low, const char_type* __high) const
-    {
-        for (; __low != __high; ++__low)
-            if (isascii(*__low) && (__tab_[static_cast<int>(*__low)] & __m))
-                break;
-        return __low;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* scan_not(mask __m, const char_type* __low, const char_type* __high) const
-    {
-        for (; __low != __high; ++__low)
-            if (!(isascii(*__low) && (__tab_[static_cast<int>(*__low)] & __m)))
-                break;
-        return __low;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    char_type toupper(char_type __c) const
-    {
-        return do_toupper(__c);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* toupper(char_type* __low, const char_type* __high) const
-    {
-        return do_toupper(__low, __high);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    char_type tolower(char_type __c) const
-    {
-        return do_tolower(__c);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char_type* tolower(char_type* __low, const char_type* __high) const
-    {
-        return do_tolower(__low, __high);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    char_type widen(char __c) const
-    {
-        return do_widen(__c);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char* widen(const char* __low, const char* __high, char_type* __to) const
-    {
-        return do_widen(__low, __high, __to);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    char narrow(char_type __c, char __dfault) const
-    {
-        return do_narrow(__c, __dfault);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const char* narrow(const char_type* __low, const char_type* __high, char __dfault, char* __to) const
-    {
-        return do_narrow(__low, __high, __dfault, __to);
-    }
-
-    static locale::id id;
-
-#ifdef _CACHED_RUNES
-    static const size_t table_size = _CACHED_RUNES;
-#else
-    static const size_t table_size = 256;  // FIXME: Don't hardcode this.
-#endif
-    _LIBCPP_INLINE_VISIBILITY const mask* table() const  _NOEXCEPT {return __tab_;}
-    static const mask* classic_table()  _NOEXCEPT;
-#if defined(__GLIBC__) || defined(__EMSCRIPTEN__)
-    static const int* __classic_upper_table() _NOEXCEPT;
-    static const int* __classic_lower_table() _NOEXCEPT;
-#endif
-#if defined(__NetBSD__)
-    static const short* __classic_upper_table() _NOEXCEPT;
-    static const short* __classic_lower_table() _NOEXCEPT;
-#endif
-
-protected:
-    ~ctype();
-    virtual char_type do_toupper(char_type __c) const;
-    virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
-    virtual char_type do_tolower(char_type __c) const;
-    virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
-    virtual char_type do_widen(char __c) const;
-    virtual const char* do_widen(const char* __low, const char* __high, char_type* __to) const;
-    virtual char do_narrow(char_type __c, char __dfault) const;
-    virtual const char* do_narrow(const char_type* __low, const char_type* __high, char __dfault, char* __to) const;
-};
-
-// template <class CharT> class ctype_byname;
-
-template <class _CharT> class _LIBCPP_TEMPLATE_VIS ctype_byname;
-
-template <>
-class _LIBCPP_TYPE_VIS ctype_byname<char>
-    : public ctype<char>
-{
-    locale_t __l;
-
-public:
-    explicit ctype_byname(const char*, size_t = 0);
-    explicit ctype_byname(const string&, size_t = 0);
-
-protected:
-    ~ctype_byname();
-    virtual char_type do_toupper(char_type) const;
-    virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
-    virtual char_type do_tolower(char_type) const;
-    virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
-};
-
-template <>
-class _LIBCPP_TYPE_VIS ctype_byname<wchar_t>
-    : public ctype<wchar_t>
-{
-    locale_t __l;
-
-public:
-    explicit ctype_byname(const char*, size_t = 0);
-    explicit ctype_byname(const string&, size_t = 0);
-
-protected:
-    ~ctype_byname();
-    virtual bool do_is(mask __m, char_type __c) const;
-    virtual const char_type* do_is(const char_type* __low, const char_type* __high, mask* __vec) const;
-    virtual const char_type* do_scan_is(mask __m, const char_type* __low, const char_type* __high) const;
-    virtual const char_type* do_scan_not(mask __m, const char_type* __low, const char_type* __high) const;
-    virtual char_type do_toupper(char_type) const;
-    virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
-    virtual char_type do_tolower(char_type) const;
-    virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
-    virtual char_type do_widen(char) const;
-    virtual const char* do_widen(const char* __low, const char* __high, char_type* __dest) const;
-    virtual char do_narrow(char_type, char __dfault) const;
-    virtual const char_type* do_narrow(const char_type* __low, const char_type* __high, char __dfault, char* __dest) const;
-};
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isspace(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::space, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isprint(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::print, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-iscntrl(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::cntrl, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isupper(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::upper, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-islower(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::lower, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isalpha(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::alpha, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isdigit(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::digit, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-ispunct(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::punct, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isxdigit(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::xdigit, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isalnum(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::alnum, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isgraph(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).is(ctype_base::graph, __c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-_CharT
-toupper(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).toupper(__c);
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-_CharT
-tolower(_CharT __c, const locale& __loc)
-{
-    return use_facet<ctype<_CharT> >(__loc).tolower(__c);
-}
-
-// codecvt_base
-
-class _LIBCPP_TYPE_VIS codecvt_base
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY codecvt_base() {}
-    enum result {ok, partial, error, noconv};
-};
-
-// template <class internT, class externT, class stateT> class codecvt;
-
-template <class _InternT, class _ExternT, class _StateT> class _LIBCPP_TEMPLATE_VIS codecvt;
-
-// template <> class codecvt<char, char, mbstate_t>
-
-template <>
-class _LIBCPP_TYPE_VIS codecvt<char, char, mbstate_t>
-    : public locale::facet,
-      public codecvt_base
-{
-public:
-    typedef char      intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
-    {
-        return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
-    {
-        return do_unshift(__st, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const
-    {
-        return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int encoding() const  _NOEXCEPT
-    {
-        return do_encoding();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool always_noconv() const  _NOEXCEPT
-    {
-        return do_always_noconv();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const
-    {
-        return do_length(__st, __frm, __end, __mx);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int max_length() const  _NOEXCEPT
-    {
-        return do_max_length();
-    }
-
-    static locale::id id;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt(const char*, size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    ~codecvt();
-
-    virtual result do_out(state_type& __st,
-                          const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-                          extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result do_in(state_type& __st,
-                         const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-                         intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result do_unshift(state_type& __st,
-                              extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const  _NOEXCEPT;
-    virtual bool do_always_noconv() const  _NOEXCEPT;
-    virtual int do_length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
-    virtual int do_max_length() const  _NOEXCEPT;
-};
-
-// template <> class codecvt<wchar_t, char, mbstate_t>
-
-template <>
-class _LIBCPP_TYPE_VIS codecvt<wchar_t, char, mbstate_t>
-    : public locale::facet,
-      public codecvt_base
-{
-    locale_t __l;
-public:
-    typedef wchar_t   intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    explicit codecvt(size_t __refs = 0);
-
-    _LIBCPP_INLINE_VISIBILITY
-    result out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
-    {
-        return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
-    {
-        return do_unshift(__st, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const
-    {
-        return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int encoding() const  _NOEXCEPT
-    {
-        return do_encoding();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool always_noconv() const  _NOEXCEPT
-    {
-        return do_always_noconv();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const
-    {
-        return do_length(__st, __frm, __end, __mx);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int max_length() const  _NOEXCEPT
-    {
-        return do_max_length();
-    }
-
-    static locale::id id;
-
-protected:
-    explicit codecvt(const char*, size_t __refs = 0);
-
-    ~codecvt();
-
-    virtual result do_out(state_type& __st,
-                          const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-                          extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result do_in(state_type& __st,
-                         const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-                         intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result do_unshift(state_type& __st,
-                              extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const  _NOEXCEPT;
-    virtual bool do_always_noconv() const  _NOEXCEPT;
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
-    virtual int do_max_length() const  _NOEXCEPT;
-};
-
-// template <> class codecvt<char16_t, char, mbstate_t>
-
-template <>
-class _LIBCPP_TYPE_VIS codecvt<char16_t, char, mbstate_t>
-    : public locale::facet,
-      public codecvt_base
-{
-public:
-    typedef char16_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
-    {
-        return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
-    {
-        return do_unshift(__st, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const
-    {
-        return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int encoding() const  _NOEXCEPT
-    {
-        return do_encoding();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool always_noconv() const  _NOEXCEPT
-    {
-        return do_always_noconv();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const
-    {
-        return do_length(__st, __frm, __end, __mx);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int max_length() const  _NOEXCEPT
-    {
-        return do_max_length();
-    }
-
-    static locale::id id;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt(const char*, size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    ~codecvt();
-
-    virtual result do_out(state_type& __st,
-                          const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-                          extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result do_in(state_type& __st,
-                         const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-                         intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result do_unshift(state_type& __st,
-                              extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const  _NOEXCEPT;
-    virtual bool do_always_noconv() const  _NOEXCEPT;
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
-    virtual int do_max_length() const  _NOEXCEPT;
-};
-
-// template <> class codecvt<char32_t, char, mbstate_t>
-
-template <>
-class _LIBCPP_TYPE_VIS codecvt<char32_t, char, mbstate_t>
-    : public locale::facet,
-      public codecvt_base
-{
-public:
-    typedef char32_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
-    {
-        return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const
-    {
-        return do_unshift(__st, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const
-    {
-        return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int encoding() const  _NOEXCEPT
-    {
-        return do_encoding();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool always_noconv() const  _NOEXCEPT
-    {
-        return do_always_noconv();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const
-    {
-        return do_length(__st, __frm, __end, __mx);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int max_length() const  _NOEXCEPT
-    {
-        return do_max_length();
-    }
-
-    static locale::id id;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt(const char*, size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    ~codecvt();
-
-    virtual result do_out(state_type& __st,
-                          const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-                          extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result do_in(state_type& __st,
-                         const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-                         intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result do_unshift(state_type& __st,
-                              extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const  _NOEXCEPT;
-    virtual bool do_always_noconv() const  _NOEXCEPT;
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
-    virtual int do_max_length() const  _NOEXCEPT;
-};
-
-// template <class _InternT, class _ExternT, class _StateT> class codecvt_byname
-
-template <class _InternT, class _ExternT, class _StateT>
-class _LIBCPP_TEMPLATE_VIS codecvt_byname
-    : public codecvt<_InternT, _ExternT, _StateT>
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt_byname(const char* __nm, size_t __refs = 0)
-        : codecvt<_InternT, _ExternT, _StateT>(__nm, __refs) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt_byname(const string& __nm, size_t __refs = 0)
-        : codecvt<_InternT, _ExternT, _StateT>(__nm.c_str(), __refs) {}
-protected:
-    ~codecvt_byname();
-};
-
-template <class _InternT, class _ExternT, class _StateT>
-codecvt_byname<_InternT, _ExternT, _StateT>::~codecvt_byname()
-{
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char, char, mbstate_t>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<wchar_t, char, mbstate_t>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char16_t, char, mbstate_t>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char32_t, char, mbstate_t>)
-
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_runtime_error(const char*);
-
-template <size_t _Np>
-struct __narrow_to_utf8
-{
-    template <class _OutputIterator, class _CharT>
-    _OutputIterator
-    operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const;
-};
-
-template <>
-struct __narrow_to_utf8<8>
-{
-    template <class _OutputIterator, class _CharT>
-    _LIBCPP_INLINE_VISIBILITY
-    _OutputIterator
-    operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const
-    {
-        for (; __wb < __we; ++__wb, ++__s)
-            *__s = *__wb;
-        return __s;
-    }
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS __narrow_to_utf8<16>
-    : public codecvt<char16_t, char, mbstate_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    __narrow_to_utf8() : codecvt<char16_t, char, mbstate_t>(1) {}
-
-    _LIBCPP_EXPORTED_FROM_ABI ~__narrow_to_utf8();
-
-    template <class _OutputIterator, class _CharT>
-    _LIBCPP_INLINE_VISIBILITY
-    _OutputIterator
-    operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const
-    {
-        result __r = ok;
-        mbstate_t __mb;
-        while (__wb < __we && __r != error)
-        {
-            const int __sz = 32;
-            char __buf[__sz];
-            char* __bn;
-            const char16_t* __wn = (const char16_t*)__wb;
-            __r = do_out(__mb, (const char16_t*)__wb, (const char16_t*)__we, __wn,
-                         __buf, __buf+__sz, __bn);
-            if (__r == codecvt_base::error || __wn == (const char16_t*)__wb)
-                __throw_runtime_error("locale not supported");
-            for (const char* __p = __buf; __p < __bn; ++__p, ++__s)
-                *__s = *__p;
-            __wb = (const _CharT*)__wn;
-        }
-        return __s;
-    }
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS __narrow_to_utf8<32>
-    : public codecvt<char32_t, char, mbstate_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    __narrow_to_utf8() : codecvt<char32_t, char, mbstate_t>(1) {}
-
-    _LIBCPP_EXPORTED_FROM_ABI ~__narrow_to_utf8();
-
-    template <class _OutputIterator, class _CharT>
-    _LIBCPP_INLINE_VISIBILITY
-    _OutputIterator
-    operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const
-    {
-        result __r = ok;
-        mbstate_t __mb;
-        while (__wb < __we && __r != error)
-        {
-            const int __sz = 32;
-            char __buf[__sz];
-            char* __bn;
-            const char32_t* __wn = (const char32_t*)__wb;
-            __r = do_out(__mb, (const char32_t*)__wb, (const char32_t*)__we, __wn,
-                         __buf, __buf+__sz, __bn);
-            if (__r == codecvt_base::error || __wn == (const char32_t*)__wb)
-                __throw_runtime_error("locale not supported");
-            for (const char* __p = __buf; __p < __bn; ++__p, ++__s)
-                *__s = *__p;
-            __wb = (const _CharT*)__wn;
-        }
-        return __s;
-    }
-};
-
-template <size_t _Np>
-struct __widen_from_utf8
-{
-    template <class _OutputIterator>
-    _OutputIterator
-    operator()(_OutputIterator __s, const char* __nb, const char* __ne) const;
-};
-
-template <>
-struct __widen_from_utf8<8>
-{
-    template <class _OutputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-    _OutputIterator
-    operator()(_OutputIterator __s, const char* __nb, const char* __ne) const
-    {
-        for (; __nb < __ne; ++__nb, ++__s)
-            *__s = *__nb;
-        return __s;
-    }
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS __widen_from_utf8<16>
-    : public codecvt<char16_t, char, mbstate_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    __widen_from_utf8() : codecvt<char16_t, char, mbstate_t>(1) {}
-
-    _LIBCPP_EXPORTED_FROM_ABI ~__widen_from_utf8();
-
-    template <class _OutputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-    _OutputIterator
-    operator()(_OutputIterator __s, const char* __nb, const char* __ne) const
-    {
-        result __r = ok;
-        mbstate_t __mb;
-        while (__nb < __ne && __r != error)
-        {
-            const int __sz = 32;
-            char16_t __buf[__sz];
-            char16_t* __bn;
-            const char* __nn = __nb;
-            __r = do_in(__mb, __nb, __ne - __nb > __sz ? __nb+__sz : __ne, __nn,
-                        __buf, __buf+__sz, __bn);
-            if (__r == codecvt_base::error || __nn == __nb)
-                __throw_runtime_error("locale not supported");
-            for (const char16_t* __p = __buf; __p < __bn; ++__p, ++__s)
-                *__s = (wchar_t)*__p;
-            __nb = __nn;
-        }
-        return __s;
-    }
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS __widen_from_utf8<32>
-    : public codecvt<char32_t, char, mbstate_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    __widen_from_utf8() : codecvt<char32_t, char, mbstate_t>(1) {}
-
-    _LIBCPP_EXPORTED_FROM_ABI ~__widen_from_utf8();
-
-    template <class _OutputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-    _OutputIterator
-    operator()(_OutputIterator __s, const char* __nb, const char* __ne) const
-    {
-        result __r = ok;
-        mbstate_t __mb;
-        while (__nb < __ne && __r != error)
-        {
-            const int __sz = 32;
-            char32_t __buf[__sz];
-            char32_t* __bn;
-            const char* __nn = __nb;
-            __r = do_in(__mb, __nb, __ne - __nb > __sz ? __nb+__sz : __ne, __nn,
-                        __buf, __buf+__sz, __bn);
-            if (__r == codecvt_base::error || __nn == __nb)
-                __throw_runtime_error("locale not supported");
-            for (const char32_t* __p = __buf; __p < __bn; ++__p, ++__s)
-                *__s = (wchar_t)*__p;
-            __nb = __nn;
-        }
-        return __s;
-    }
-};
-
-// template <class charT> class numpunct
-
-template <class _CharT> class _LIBCPP_TEMPLATE_VIS numpunct;
-
-template <>
-class _LIBCPP_TYPE_VIS numpunct<char>
-    : public locale::facet
-{
-public:
-    typedef char char_type;
-    typedef basic_string<char_type> string_type;
-
-    explicit numpunct(size_t __refs = 0);
-
-    _LIBCPP_INLINE_VISIBILITY char_type decimal_point() const {return do_decimal_point();}
-    _LIBCPP_INLINE_VISIBILITY char_type thousands_sep() const {return do_thousands_sep();}
-    _LIBCPP_INLINE_VISIBILITY string grouping() const         {return do_grouping();}
-    _LIBCPP_INLINE_VISIBILITY string_type truename() const    {return do_truename();}
-    _LIBCPP_INLINE_VISIBILITY string_type falsename() const   {return do_falsename();}
-
-    static locale::id id;
-
-protected:
-    ~numpunct();
-    virtual char_type do_decimal_point() const;
-    virtual char_type do_thousands_sep() const;
-    virtual string do_grouping() const;
-    virtual string_type do_truename() const;
-    virtual string_type do_falsename() const;
-
-    char_type __decimal_point_;
-    char_type __thousands_sep_;
-    string __grouping_;
-};
-
-template <>
-class _LIBCPP_TYPE_VIS numpunct<wchar_t>
-    : public locale::facet
-{
-public:
-    typedef wchar_t char_type;
-    typedef basic_string<char_type> string_type;
-
-    explicit numpunct(size_t __refs = 0);
-
-    _LIBCPP_INLINE_VISIBILITY char_type decimal_point() const {return do_decimal_point();}
-    _LIBCPP_INLINE_VISIBILITY char_type thousands_sep() const {return do_thousands_sep();}
-    _LIBCPP_INLINE_VISIBILITY string grouping() const         {return do_grouping();}
-    _LIBCPP_INLINE_VISIBILITY string_type truename() const    {return do_truename();}
-    _LIBCPP_INLINE_VISIBILITY string_type falsename() const   {return do_falsename();}
-
-    static locale::id id;
-
-protected:
-    ~numpunct();
-    virtual char_type do_decimal_point() const;
-    virtual char_type do_thousands_sep() const;
-    virtual string do_grouping() const;
-    virtual string_type do_truename() const;
-    virtual string_type do_falsename() const;
-
-    char_type __decimal_point_;
-    char_type __thousands_sep_;
-    string __grouping_;
-};
-
-// template <class charT> class numpunct_byname
-
-template <class _CharT> class _LIBCPP_TEMPLATE_VIS numpunct_byname;
-
-template <>
-class _LIBCPP_TYPE_VIS numpunct_byname<char>
-: public numpunct<char>
-{
-public:
-    typedef char char_type;
-    typedef basic_string<char_type> string_type;
-
-    explicit numpunct_byname(const char* __nm, size_t __refs = 0);
-    explicit numpunct_byname(const string& __nm, size_t __refs = 0);
-
-protected:
-    ~numpunct_byname();
-
-private:
-    void __init(const char*);
-};
-
-template <>
-class _LIBCPP_TYPE_VIS numpunct_byname<wchar_t>
-: public numpunct<wchar_t>
-{
-public:
-    typedef wchar_t char_type;
-    typedef basic_string<char_type> string_type;
-
-    explicit numpunct_byname(const char* __nm, size_t __refs = 0);
-    explicit numpunct_byname(const string& __nm, size_t __refs = 0);
-
-protected:
-    ~numpunct_byname();
-
-private:
-    void __init(const char*);
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP___LOCALE
diff --git a/lib/libcxx/include/__mutex_base b/lib/libcxx/include/__mutex_base
deleted file mode 100644
index da21a5f8eb6..00000000000
--- a/lib/libcxx/include/__mutex_base
+++ /dev/null
@@ -1,440 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___MUTEX_BASE
-#define _LIBCPP___MUTEX_BASE
-
-#include <__config>
-#include <chrono>
-#include <system_error>
-#include <__threading_support>
-
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#ifndef _LIBCPP_HAS_NO_THREADS
-
-#ifndef _LIBCPP_THREAD_SAFETY_ANNOTATION
-#  ifdef _LIBCPP_HAS_THREAD_SAFETY_ANNOTATIONS
-#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x) __attribute__((x))
-#  else
-#    define _LIBCPP_THREAD_SAFETY_ANNOTATION(x)
-#  endif
-#endif  // _LIBCPP_THREAD_SAFETY_ANNOTATION
-
-class _LIBCPP_TYPE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(capability("mutex")) mutex
-{
-#ifndef _LIBCPP_CXX03_LANG
-    __libcpp_mutex_t __m_ = _LIBCPP_MUTEX_INITIALIZER;
-#else
-    __libcpp_mutex_t __m_;
-#endif
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_CXX03_LANG
-    constexpr mutex() = default;
-#else
-    mutex() _NOEXCEPT {__m_ = (__libcpp_mutex_t)_LIBCPP_MUTEX_INITIALIZER;}
-#endif
-    ~mutex();
-
-private:
-    mutex(const mutex&);// = delete;
-    mutex& operator=(const mutex&);// = delete;
-
-public:
-    void lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability());
-    bool try_lock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(try_acquire_capability(true));
-    void unlock() _NOEXCEPT _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability());
-
-    typedef __libcpp_mutex_t* native_handle_type;
-    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__m_;}
-};
-
-static_assert(is_nothrow_default_constructible<mutex>::value,
-              "the default constructor for std::mutex must be nothrow");
-
-struct _LIBCPP_TYPE_VIS defer_lock_t {};
-struct _LIBCPP_TYPE_VIS try_to_lock_t {};
-struct _LIBCPP_TYPE_VIS adopt_lock_t {};
-
-#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
-
-extern _LIBCPP_EXPORTED_FROM_ABI const defer_lock_t  defer_lock;
-extern _LIBCPP_EXPORTED_FROM_ABI const try_to_lock_t try_to_lock;
-extern _LIBCPP_EXPORTED_FROM_ABI const adopt_lock_t  adopt_lock;
-
-#else
-
-/* _LIBCPP_INLINE_VAR */ constexpr defer_lock_t  defer_lock  = defer_lock_t();
-/* _LIBCPP_INLINE_VAR */ constexpr try_to_lock_t try_to_lock = try_to_lock_t();
-/* _LIBCPP_INLINE_VAR */ constexpr adopt_lock_t  adopt_lock  = adopt_lock_t();
-
-#endif
-
-template <class _Mutex>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable)
-lock_guard
-{
-public:
-    typedef _Mutex mutex_type;
-
-private:
-    mutex_type& __m_;
-public:
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit lock_guard(mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
-        : __m_(__m) {__m_.lock();}
-    _LIBCPP_INLINE_VISIBILITY
-    lock_guard(mutex_type& __m, adopt_lock_t) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
-        : __m_(__m) {}
-    _LIBCPP_INLINE_VISIBILITY
-    ~lock_guard() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}
-
-private:
-    lock_guard(lock_guard const&) _LIBCPP_EQUAL_DELETE;
-    lock_guard& operator=(lock_guard const&) _LIBCPP_EQUAL_DELETE;
-};
-
-template <class _Mutex>
-class _LIBCPP_TEMPLATE_VIS unique_lock
-{
-public:
-    typedef _Mutex mutex_type;
-
-private:
-    mutex_type* __m_;
-    bool __owns_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    unique_lock() _NOEXCEPT : __m_(nullptr), __owns_(false) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit unique_lock(mutex_type& __m)
-        : __m_(_VSTD::addressof(__m)), __owns_(true) {__m_->lock();}
-    _LIBCPP_INLINE_VISIBILITY
-    unique_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
-        : __m_(_VSTD::addressof(__m)), __owns_(false) {}
-    _LIBCPP_INLINE_VISIBILITY
-    unique_lock(mutex_type& __m, try_to_lock_t)
-        : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock()) {}
-    _LIBCPP_INLINE_VISIBILITY
-    unique_lock(mutex_type& __m, adopt_lock_t)
-        : __m_(_VSTD::addressof(__m)), __owns_(true) {}
-    template <class _Clock, class _Duration>
-    _LIBCPP_INLINE_VISIBILITY
-        unique_lock(mutex_type& __m, const chrono::time_point<_Clock, _Duration>& __t)
-            : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock_until(__t)) {}
-    template <class _Rep, class _Period>
-    _LIBCPP_INLINE_VISIBILITY
-        unique_lock(mutex_type& __m, const chrono::duration<_Rep, _Period>& __d)
-            : __m_(_VSTD::addressof(__m)), __owns_(__m.try_lock_for(__d)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    ~unique_lock()
-    {
-        if (__owns_)
-            __m_->unlock();
-    }
-
-private:
-    unique_lock(unique_lock const&); // = delete;
-    unique_lock& operator=(unique_lock const&); // = delete;
-
-public:
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    unique_lock(unique_lock&& __u) _NOEXCEPT
-        : __m_(__u.__m_), __owns_(__u.__owns_)
-        {__u.__m_ = nullptr; __u.__owns_ = false;}
-    _LIBCPP_INLINE_VISIBILITY
-    unique_lock& operator=(unique_lock&& __u) _NOEXCEPT
-        {
-            if (__owns_)
-                __m_->unlock();
-            __m_ = __u.__m_;
-            __owns_ = __u.__owns_;
-            __u.__m_ = nullptr;
-            __u.__owns_ = false;
-            return *this;
-        }
-
-#endif  // _LIBCPP_CXX03_LANG
-
-    void lock();
-    bool try_lock();
-
-    template <class _Rep, class _Period>
-        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d);
-    template <class _Clock, class _Duration>
-        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
-
-    void unlock();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(unique_lock& __u) _NOEXCEPT
-    {
-        _VSTD::swap(__m_, __u.__m_);
-        _VSTD::swap(__owns_, __u.__owns_);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    mutex_type* release() _NOEXCEPT
-    {
-        mutex_type* __m = __m_;
-        __m_ = nullptr;
-        __owns_ = false;
-        return __m;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool owns_lock() const _NOEXCEPT {return __owns_;}
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_EXPLICIT
-        operator bool () const _NOEXCEPT {return __owns_;}
-    _LIBCPP_INLINE_VISIBILITY
-    mutex_type* mutex() const _NOEXCEPT {return __m_;}
-};
-
-template <class _Mutex>
-void
-unique_lock<_Mutex>::lock()
-{
-    if (__m_ == nullptr)
-        __throw_system_error(EPERM, "unique_lock::lock: references null mutex");
-    if (__owns_)
-        __throw_system_error(EDEADLK, "unique_lock::lock: already locked");
-    __m_->lock();
-    __owns_ = true;
-}
-
-template <class _Mutex>
-bool
-unique_lock<_Mutex>::try_lock()
-{
-    if (__m_ == nullptr)
-        __throw_system_error(EPERM, "unique_lock::try_lock: references null mutex");
-    if (__owns_)
-        __throw_system_error(EDEADLK, "unique_lock::try_lock: already locked");
-    __owns_ = __m_->try_lock();
-    return __owns_;
-}
-
-template <class _Mutex>
-template <class _Rep, class _Period>
-bool
-unique_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
-{
-    if (__m_ == nullptr)
-        __throw_system_error(EPERM, "unique_lock::try_lock_for: references null mutex");
-    if (__owns_)
-        __throw_system_error(EDEADLK, "unique_lock::try_lock_for: already locked");
-    __owns_ = __m_->try_lock_for(__d);
-    return __owns_;
-}
-
-template <class _Mutex>
-template <class _Clock, class _Duration>
-bool
-unique_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
-{
-    if (__m_ == nullptr)
-        __throw_system_error(EPERM, "unique_lock::try_lock_until: references null mutex");
-    if (__owns_)
-        __throw_system_error(EDEADLK, "unique_lock::try_lock_until: already locked");
-    __owns_ = __m_->try_lock_until(__t);
-    return __owns_;
-}
-
-template <class _Mutex>
-void
-unique_lock<_Mutex>::unlock()
-{
-    if (!__owns_)
-        __throw_system_error(EPERM, "unique_lock::unlock: not locked");
-    __m_->unlock();
-    __owns_ = false;
-}
-
-template <class _Mutex>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(unique_lock<_Mutex>& __x, unique_lock<_Mutex>& __y) _NOEXCEPT
-    {__x.swap(__y);}
-
-//enum class cv_status
-_LIBCPP_DECLARE_STRONG_ENUM(cv_status)
-{
-    no_timeout,
-    timeout
-};
-_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(cv_status)
-
-class _LIBCPP_TYPE_VIS condition_variable
-{
-#ifndef _LIBCPP_CXX03_LANG
-    __libcpp_condvar_t __cv_ = _LIBCPP_CONDVAR_INITIALIZER;
-#else
-    __libcpp_condvar_t __cv_;
-#endif
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_CXX03_LANG
-    constexpr condition_variable() _NOEXCEPT = default;
-#else
-    condition_variable() _NOEXCEPT {__cv_ = (__libcpp_condvar_t)_LIBCPP_CONDVAR_INITIALIZER;}
-#endif
-    ~condition_variable();
-
-private:
-    condition_variable(const condition_variable&); // = delete;
-    condition_variable& operator=(const condition_variable&); // = delete;
-
-public:
-    void notify_one() _NOEXCEPT;
-    void notify_all() _NOEXCEPT;
-
-    void wait(unique_lock<mutex>& __lk) _NOEXCEPT;
-    template <class _Predicate>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        void wait(unique_lock<mutex>& __lk, _Predicate __pred);
-
-    template <class _Clock, class _Duration>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        cv_status
-        wait_until(unique_lock<mutex>& __lk,
-                   const chrono::time_point<_Clock, _Duration>& __t);
-
-    template <class _Clock, class _Duration, class _Predicate>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        bool
-        wait_until(unique_lock<mutex>& __lk,
-                   const chrono::time_point<_Clock, _Duration>& __t,
-                   _Predicate __pred);
-
-    template <class _Rep, class _Period>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        cv_status
-        wait_for(unique_lock<mutex>& __lk,
-                 const chrono::duration<_Rep, _Period>& __d);
-
-    template <class _Rep, class _Period, class _Predicate>
-        bool
-        _LIBCPP_INLINE_VISIBILITY
-        wait_for(unique_lock<mutex>& __lk,
-                 const chrono::duration<_Rep, _Period>& __d,
-                 _Predicate __pred);
-
-    typedef __libcpp_condvar_t* native_handle_type;
-    _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() {return &__cv_;}
-
-private:
-    void __do_timed_wait(unique_lock<mutex>& __lk,
-       chrono::time_point<chrono::system_clock, chrono::nanoseconds>) _NOEXCEPT;
-};
-#endif // !_LIBCPP_HAS_NO_THREADS
-
-template <class _To, class _Rep, class _Period>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    chrono::__is_duration<_To>::value,
-    _To
->::type
-__ceil(chrono::duration<_Rep, _Period> __d)
-{
-    using namespace chrono;
-    _To __r = duration_cast<_To>(__d);
-    if (__r < __d)
-        ++__r;
-    return __r;
-}
-
-#ifndef _LIBCPP_HAS_NO_THREADS
-template <class _Predicate>
-void
-condition_variable::wait(unique_lock<mutex>& __lk, _Predicate __pred)
-{
-    while (!__pred())
-        wait(__lk);
-}
-
-template <class _Clock, class _Duration>
-cv_status
-condition_variable::wait_until(unique_lock<mutex>& __lk,
-                               const chrono::time_point<_Clock, _Duration>& __t)
-{
-    using namespace chrono;
-    wait_for(__lk, __t - _Clock::now());
-    return _Clock::now() < __t ? cv_status::no_timeout : cv_status::timeout;
-}
-
-template <class _Clock, class _Duration, class _Predicate>
-bool
-condition_variable::wait_until(unique_lock<mutex>& __lk,
-                   const chrono::time_point<_Clock, _Duration>& __t,
-                   _Predicate __pred)
-{
-    while (!__pred())
-    {
-        if (wait_until(__lk, __t) == cv_status::timeout)
-            return __pred();
-    }
-    return true;
-}
-
-template <class _Rep, class _Period>
-cv_status
-condition_variable::wait_for(unique_lock<mutex>& __lk,
-                             const chrono::duration<_Rep, _Period>& __d)
-{
-    using namespace chrono;
-    if (__d <= __d.zero())
-        return cv_status::timeout;
-    typedef time_point<system_clock, duration<long double, nano> > __sys_tpf;
-    typedef time_point<system_clock, nanoseconds> __sys_tpi;
-    __sys_tpf _Max = __sys_tpi::max();
-    steady_clock::time_point __c_now = steady_clock::now();
-    system_clock::time_point __s_now = system_clock::now();
-    if (_Max - __d > __s_now)
-        __do_timed_wait(__lk, __s_now + __ceil<nanoseconds>(__d));
-    else
-        __do_timed_wait(__lk, __sys_tpi::max());
-    return steady_clock::now() - __c_now < __d ? cv_status::no_timeout :
-                                                 cv_status::timeout;
-}
-
-template <class _Rep, class _Period, class _Predicate>
-inline
-bool
-condition_variable::wait_for(unique_lock<mutex>& __lk,
-                             const chrono::duration<_Rep, _Period>& __d,
-                             _Predicate __pred)
-{
-    return wait_until(__lk, chrono::steady_clock::now() + __d,
-                      _VSTD::move(__pred));
-}
-
-#endif // !_LIBCPP_HAS_NO_THREADS
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP___MUTEX_BASE
diff --git a/lib/libcxx/include/__node_handle b/lib/libcxx/include/__node_handle
deleted file mode 100644
index a9cf3b7217a..00000000000
--- a/lib/libcxx/include/__node_handle
+++ /dev/null
@@ -1,210 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___NODE_HANDLE
-#define _LIBCPP___NODE_HANDLE
-
-#include <__config>
-#include <memory>
-#include <optional>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER > 14
-
-// Specialized in __tree & __hash_table for their _NodeType.
-template <class _NodeType, class _Alloc>
-struct __generic_container_node_destructor;
-
-template <class _NodeType, class _Alloc,
-          template <class, class> class _MapOrSetSpecifics>
-class _LIBCPP_TEMPLATE_VIS __basic_node_handle
-    : public _MapOrSetSpecifics<
-          _NodeType,
-          __basic_node_handle<_NodeType, _Alloc, _MapOrSetSpecifics>>
-{
-    template <class _Tp, class _Compare, class _Allocator>
-        friend class __tree;
-    template <class _Tp, class _Hash, class _Equal, class _Allocator>
-        friend class __hash_table;
-    friend struct _MapOrSetSpecifics<
-        _NodeType, __basic_node_handle<_NodeType, _Alloc, _MapOrSetSpecifics>>;
-
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_pointer<typename __alloc_traits::void_pointer,
-                                      _NodeType>::type
-        __node_pointer_type;
-
-public:
-    typedef _Alloc allocator_type;
-
-private:
-    __node_pointer_type __ptr_ = nullptr;
-    optional<allocator_type> __alloc_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __release()
-    {
-        __ptr_ = nullptr;
-        __alloc_ = _VSTD::nullopt;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __destroy_node_pointer()
-    {
-        if (__ptr_ != nullptr)
-        {
-            typedef typename __allocator_traits_rebind<
-                allocator_type, _NodeType>::type __node_alloc_type;
-            __node_alloc_type __alloc(*__alloc_);
-            __generic_container_node_destructor<_NodeType, __node_alloc_type>(
-                __alloc, true)(__ptr_);
-            __ptr_ = nullptr;
-        }
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __basic_node_handle(__node_pointer_type __ptr,
-                        allocator_type const& __alloc)
-            : __ptr_(__ptr), __alloc_(__alloc)
-    {
-    }
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __basic_node_handle() = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __basic_node_handle(__basic_node_handle&& __other) noexcept
-            : __ptr_(__other.__ptr_),
-              __alloc_(_VSTD::move(__other.__alloc_))
-    {
-        __other.__ptr_ = nullptr;
-        __other.__alloc_ = _VSTD::nullopt;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __basic_node_handle& operator=(__basic_node_handle&& __other)
-    {
-        _LIBCPP_ASSERT(
-            __alloc_ == _VSTD::nullopt ||
-            __alloc_traits::propagate_on_container_move_assignment::value ||
-            __alloc_ == __other.__alloc_,
-            "node_type with incompatible allocator passed to "
-            "node_type::operator=(node_type&&)");
-
-        __destroy_node_pointer();
-        __ptr_ = __other.__ptr_;
-
-        if (__alloc_traits::propagate_on_container_move_assignment::value ||
-            __alloc_ == _VSTD::nullopt)
-            __alloc_ = _VSTD::move(__other.__alloc_);
-
-        __other.__ptr_ = nullptr;
-        __other.__alloc_ = _VSTD::nullopt;
-
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const { return *__alloc_; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit operator bool() const { return __ptr_ != nullptr; }
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const { return __ptr_ == nullptr; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(__basic_node_handle& __other) noexcept(
-        __alloc_traits::propagate_on_container_swap::value ||
-        __alloc_traits::is_always_equal::value)
-    {
-        using _VSTD::swap;
-        swap(__ptr_, __other.__ptr_);
-        if (__alloc_traits::propagate_on_container_swap::value ||
-            __alloc_ == _VSTD::nullopt || __other.__alloc_ == _VSTD::nullopt)
-            swap(__alloc_, __other.__alloc_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    friend void swap(__basic_node_handle& __a, __basic_node_handle& __b)
-        noexcept(noexcept(__a.swap(__b))) { __a.swap(__b); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__basic_node_handle()
-    {
-        __destroy_node_pointer();
-    }
-};
-
-template <class _NodeType, class _Derived>
-struct __set_node_handle_specifics
-{
-    typedef typename _NodeType::__node_value_type value_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type& value() const
-    {
-        return static_cast<_Derived const*>(this)->__ptr_->__value_;
-    }
-};
-
-template <class _NodeType, class _Derived>
-struct __map_node_handle_specifics
-{
-    typedef typename _NodeType::__node_value_type::key_type key_type;
-    typedef typename _NodeType::__node_value_type::mapped_type mapped_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    key_type& key() const
-    {
-        return static_cast<_Derived const*>(this)->
-            __ptr_->__value_.__ref().first;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    mapped_type& mapped() const
-    {
-        return static_cast<_Derived const*>(this)->
-            __ptr_->__value_.__ref().second;
-    }
-};
-
-template <class _NodeType, class _Alloc>
-using __set_node_handle =
-    __basic_node_handle< _NodeType, _Alloc, __set_node_handle_specifics>;
-
-template <class _NodeType, class _Alloc>
-using __map_node_handle =
-    __basic_node_handle< _NodeType, _Alloc, __map_node_handle_specifics>;
-
-template <class _Iterator, class _NodeType>
-_LIBCPP_TEMPLATE_VIS
-struct __insert_return_type
-{
-    _Iterator position;
-    bool inserted;
-    _NodeType node;
-};
-
-#endif // _LIBCPP_STD_VER > 14
-
-_LIBCPP_END_NAMESPACE_STD
-_LIBCPP_POP_MACROS
-
-#endif
diff --git a/lib/libcxx/include/__nullptr b/lib/libcxx/include/__nullptr
deleted file mode 100644
index aa3b4d2145a..00000000000
--- a/lib/libcxx/include/__nullptr
+++ /dev/null
@@ -1,62 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- __nullptr --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_NULLPTR
-#define _LIBCPP_NULLPTR
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef _LIBCPP_HAS_NO_NULLPTR
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-struct _LIBCPP_TEMPLATE_VIS nullptr_t
-{
-    void* __lx;
-
-    struct __nat {int __for_bool_;};
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t() : __lx(0) {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t(int __nat::*) : __lx(0) {}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR operator int __nat::*() const {return 0;}
-
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-        operator _Tp* () const {return 0;}
-
-    template <class _Tp, class _Up>
-        _LIBCPP_INLINE_VISIBILITY
-        operator _Tp _Up::* () const {return 0;}
-
-    friend _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR bool operator==(nullptr_t, nullptr_t) {return true;}
-    friend _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR bool operator!=(nullptr_t, nullptr_t) {return false;}
-};
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);}
-
-#define nullptr _VSTD::__get_nullptr_t()
-
-_LIBCPP_END_NAMESPACE_STD
-
-#else  // _LIBCPP_HAS_NO_NULLPTR
-
-namespace std
-{
-    typedef decltype(nullptr) nullptr_t;
-}
-
-#endif  // _LIBCPP_HAS_NO_NULLPTR
-
-#endif  // _LIBCPP_NULLPTR
diff --git a/lib/libcxx/include/__split_buffer b/lib/libcxx/include/__split_buffer
deleted file mode 100644
index 1daa4e5ada3..00000000000
--- a/lib/libcxx/include/__split_buffer
+++ /dev/null
@@ -1,637 +0,0 @@
-// -*- C++ -*-
-#ifndef _LIBCPP_SPLIT_BUFFER
-#define _LIBCPP_SPLIT_BUFFER
-
-#include <__config>
-#include <type_traits>
-#include <algorithm>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <bool>
-class __split_buffer_common
-{
-protected:
-    void __throw_length_error() const;
-    void __throw_out_of_range() const;
-};
-
-template <class _Tp, class _Allocator = allocator<_Tp> >
-struct __split_buffer
-    : private __split_buffer_common<true>
-{
-private:
-    __split_buffer(const __split_buffer&);
-    __split_buffer& operator=(const __split_buffer&);
-public:
-    typedef _Tp                                             value_type;
-    typedef _Allocator                                      allocator_type;
-    typedef typename remove_reference<allocator_type>::type __alloc_rr;
-    typedef allocator_traits<__alloc_rr>                    __alloc_traits;
-    typedef value_type&                                     reference;
-    typedef const value_type&                               const_reference;
-    typedef typename __alloc_traits::size_type              size_type;
-    typedef typename __alloc_traits::difference_type        difference_type;
-    typedef typename __alloc_traits::pointer                pointer;
-    typedef typename __alloc_traits::const_pointer          const_pointer;
-    typedef pointer                                         iterator;
-    typedef const_pointer                                   const_iterator;
-
-    pointer                                         __first_;
-    pointer                                         __begin_;
-    pointer                                         __end_;
-    __compressed_pair<pointer, allocator_type> __end_cap_;
-
-    typedef typename add_lvalue_reference<allocator_type>::type __alloc_ref;
-    typedef typename add_lvalue_reference<allocator_type>::type __alloc_const_ref;
-
-    _LIBCPP_INLINE_VISIBILITY __alloc_rr&           __alloc() _NOEXCEPT         {return __end_cap_.second();}
-    _LIBCPP_INLINE_VISIBILITY const __alloc_rr&     __alloc() const _NOEXCEPT   {return __end_cap_.second();}
-    _LIBCPP_INLINE_VISIBILITY pointer&              __end_cap() _NOEXCEPT       {return __end_cap_.first();}
-    _LIBCPP_INLINE_VISIBILITY const pointer&        __end_cap() const _NOEXCEPT {return __end_cap_.first();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __split_buffer()
-        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __split_buffer(__alloc_rr& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __split_buffer(const __alloc_rr& __a);
-    __split_buffer(size_type __cap, size_type __start, __alloc_rr& __a);
-    ~__split_buffer();
-
-#ifndef _LIBCPP_CXX03_LANG
-    __split_buffer(__split_buffer&& __c)
-        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
-    __split_buffer(__split_buffer&& __c, const __alloc_rr& __a);
-    __split_buffer& operator=(__split_buffer&& __c)
-        _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
-                is_nothrow_move_assignable<allocator_type>::value) ||
-               !__alloc_traits::propagate_on_container_move_assignment::value);
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY       iterator begin() _NOEXCEPT       {return __begin_;}
-    _LIBCPP_INLINE_VISIBILITY const_iterator begin() const _NOEXCEPT {return __begin_;}
-    _LIBCPP_INLINE_VISIBILITY       iterator end() _NOEXCEPT         {return __end_;}
-    _LIBCPP_INLINE_VISIBILITY const_iterator end() const _NOEXCEPT   {return __end_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT
-        {__destruct_at_end(__begin_);}
-    _LIBCPP_INLINE_VISIBILITY size_type size() const {return static_cast<size_type>(__end_ - __begin_);}
-    _LIBCPP_INLINE_VISIBILITY bool empty()     const {return __end_ == __begin_;}
-    _LIBCPP_INLINE_VISIBILITY size_type capacity() const {return static_cast<size_type>(__end_cap() - __first_);}
-    _LIBCPP_INLINE_VISIBILITY size_type __front_spare() const {return static_cast<size_type>(__begin_ - __first_);}
-    _LIBCPP_INLINE_VISIBILITY size_type __back_spare() const {return static_cast<size_type>(__end_cap() - __end_);}
-
-    _LIBCPP_INLINE_VISIBILITY       reference front()       {return *__begin_;}
-    _LIBCPP_INLINE_VISIBILITY const_reference front() const {return *__begin_;}
-    _LIBCPP_INLINE_VISIBILITY       reference back()        {return *(__end_ - 1);}
-    _LIBCPP_INLINE_VISIBILITY const_reference back() const  {return *(__end_ - 1);}
-
-    void reserve(size_type __n);
-    void shrink_to_fit() _NOEXCEPT;
-    void push_front(const_reference __x);
-    _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
-#ifndef _LIBCPP_CXX03_LANG
-    void push_front(value_type&& __x);
-    void push_back(value_type&& __x);
-    template <class... _Args>
-        void emplace_back(_Args&&... __args);
-#endif  // !defined(_LIBCPP_CXX03_LANG)
-
-    _LIBCPP_INLINE_VISIBILITY void pop_front() {__destruct_at_begin(__begin_+1);}
-    _LIBCPP_INLINE_VISIBILITY void pop_back() {__destruct_at_end(__end_-1);}
-
-    void __construct_at_end(size_type __n);
-    void __construct_at_end(size_type __n, const_reference __x);
-    template <class _InputIter>
-        typename enable_if
-        <
-            __is_input_iterator<_InputIter>::value &&
-           !__is_forward_iterator<_InputIter>::value,
-            void
-        >::type
-        __construct_at_end(_InputIter __first, _InputIter __last);
-    template <class _ForwardIterator>
-        typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value,
-            void
-        >::type
-        __construct_at_end(_ForwardIterator __first, _ForwardIterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY void __destruct_at_begin(pointer __new_begin)
-        {__destruct_at_begin(__new_begin, is_trivially_destructible<value_type>());}
-        _LIBCPP_INLINE_VISIBILITY
-        void __destruct_at_begin(pointer __new_begin, false_type);
-        _LIBCPP_INLINE_VISIBILITY
-        void __destruct_at_begin(pointer __new_begin, true_type);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __destruct_at_end(pointer __new_last) _NOEXCEPT
-        {__destruct_at_end(__new_last, false_type());}
-    _LIBCPP_INLINE_VISIBILITY
-        void __destruct_at_end(pointer __new_last, false_type) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-        void __destruct_at_end(pointer __new_last, true_type) _NOEXCEPT;
-
-    void swap(__split_buffer& __x)
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
-                   __is_nothrow_swappable<__alloc_rr>::value);
-
-    bool __invariants() const;
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__split_buffer& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-        {
-            __alloc() = _VSTD::move(__c.__alloc());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__split_buffer&, false_type) _NOEXCEPT
-        {}
-};
-
-template <class _Tp, class _Allocator>
-bool
-__split_buffer<_Tp, _Allocator>::__invariants() const
-{
-    if (__first_ == nullptr)
-    {
-        if (__begin_ != nullptr)
-            return false;
-        if (__end_ != nullptr)
-            return false;
-        if (__end_cap() != nullptr)
-            return false;
-    }
-    else
-    {
-        if (__begin_ < __first_)
-            return false;
-        if (__end_ < __begin_)
-            return false;
-        if (__end_cap() < __end_)
-            return false;
-    }
-    return true;
-}
-
-//  Default constructs __n objects starting at __end_
-//  throws if construction throws
-//  Precondition:  __n > 0
-//  Precondition:  size() + __n <= capacity()
-//  Postcondition:  size() == size() + __n
-template <class _Tp, class _Allocator>
-void
-__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n)
-{
-    __alloc_rr& __a = this->__alloc();
-    do
-    {
-        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_));
-        ++this->__end_;
-        --__n;
-    } while (__n > 0);
-}
-
-//  Copy constructs __n objects starting at __end_ from __x
-//  throws if construction throws
-//  Precondition:  __n > 0
-//  Precondition:  size() + __n <= capacity()
-//  Postcondition:  size() == old size() + __n
-//  Postcondition:  [i] == __x for all i in [size() - __n, __n)
-template <class _Tp, class _Allocator>
-void
-__split_buffer<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x)
-{
-    __alloc_rr& __a = this->__alloc();
-    do
-    {
-        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), __x);
-        ++this->__end_;
-        --__n;
-    } while (__n > 0);
-}
-
-template <class _Tp, class _Allocator>
-template <class _InputIter>
-typename enable_if
-<
-     __is_input_iterator<_InputIter>::value &&
-    !__is_forward_iterator<_InputIter>::value,
-    void
->::type
-__split_buffer<_Tp, _Allocator>::__construct_at_end(_InputIter __first, _InputIter __last)
-{
-    __alloc_rr& __a = this->__alloc();
-    for (; __first != __last; ++__first)
-    {
-        if (__end_ == __end_cap())
-        {
-            size_type __old_cap = __end_cap() - __first_;
-            size_type __new_cap = _VSTD::max<size_type>(2 * __old_cap, 8);
-            __split_buffer __buf(__new_cap, 0, __a);
-            for (pointer __p = __begin_; __p != __end_; ++__p, ++__buf.__end_)
-                __alloc_traits::construct(__buf.__alloc(),
-                        _VSTD::__to_raw_pointer(__buf.__end_), _VSTD::move(*__p));
-            swap(__buf);
-        }
-        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), *__first);
-        ++this->__end_;
-    }
-}
-
-template <class _Tp, class _Allocator>
-template <class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value,
-    void
->::type
-__split_buffer<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last)
-{
-    __alloc_rr& __a = this->__alloc();
-    for (; __first != __last; ++__first)
-    {
-        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), *__first);
-        ++this->__end_;
-    }
-}
-
-template <class _Tp, class _Allocator>
-inline
-void
-__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, false_type)
-{
-    while (__begin_ != __new_begin)
-        __alloc_traits::destroy(__alloc(), __to_raw_pointer(__begin_++));
-}
-
-template <class _Tp, class _Allocator>
-inline
-void
-__split_buffer<_Tp, _Allocator>::__destruct_at_begin(pointer __new_begin, true_type)
-{
-    __begin_ = __new_begin;
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, false_type) _NOEXCEPT
-{
-    while (__new_last != __end_)
-        __alloc_traits::destroy(__alloc(), __to_raw_pointer(--__end_));
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__split_buffer<_Tp, _Allocator>::__destruct_at_end(pointer __new_last, true_type) _NOEXCEPT
-{
-    __end_ = __new_last;
-}
-
-template <class _Tp, class _Allocator>
-__split_buffer<_Tp, _Allocator>::__split_buffer(size_type __cap, size_type __start, __alloc_rr& __a)
-    : __end_cap_(nullptr, __a)
-{
-    __first_ = __cap != 0 ? __alloc_traits::allocate(__alloc(), __cap) : nullptr;
-    __begin_ = __end_ = __first_ + __start;
-    __end_cap() = __first_ + __cap;
-}
-
-template <class _Tp, class _Allocator>
-inline
-__split_buffer<_Tp, _Allocator>::__split_buffer()
-    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
-    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr)
-{
-}
-
-template <class _Tp, class _Allocator>
-inline
-__split_buffer<_Tp, _Allocator>::__split_buffer(__alloc_rr& __a)
-    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
-{
-}
-
-template <class _Tp, class _Allocator>
-inline
-__split_buffer<_Tp, _Allocator>::__split_buffer(const __alloc_rr& __a)
-    : __first_(nullptr), __begin_(nullptr), __end_(nullptr), __end_cap_(nullptr, __a)
-{
-}
-
-template <class _Tp, class _Allocator>
-__split_buffer<_Tp, _Allocator>::~__split_buffer()
-{
-    clear();
-    if (__first_)
-        __alloc_traits::deallocate(__alloc(), __first_, capacity());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c)
-    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
-    : __first_(_VSTD::move(__c.__first_)),
-      __begin_(_VSTD::move(__c.__begin_)),
-      __end_(_VSTD::move(__c.__end_)),
-      __end_cap_(_VSTD::move(__c.__end_cap_))
-{
-    __c.__first_ = nullptr;
-    __c.__begin_ = nullptr;
-    __c.__end_ = nullptr;
-    __c.__end_cap() = nullptr;
-}
-
-template <class _Tp, class _Allocator>
-__split_buffer<_Tp, _Allocator>::__split_buffer(__split_buffer&& __c, const __alloc_rr& __a)
-    : __end_cap_(__second_tag(), __a)
-{
-    if (__a == __c.__alloc())
-    {
-        __first_ = __c.__first_;
-        __begin_ = __c.__begin_;
-        __end_ = __c.__end_;
-        __end_cap() = __c.__end_cap();
-        __c.__first_ = nullptr;
-        __c.__begin_ = nullptr;
-        __c.__end_ = nullptr;
-        __c.__end_cap() = nullptr;
-    }
-    else
-    {
-        size_type __cap = __c.size();
-        __first_ = __alloc_traits::allocate(__alloc(), __cap);
-        __begin_ = __end_ = __first_;
-        __end_cap() = __first_ + __cap;
-        typedef move_iterator<iterator> _Ip;
-        __construct_at_end(_Ip(__c.begin()), _Ip(__c.end()));
-    }
-}
-
-template <class _Tp, class _Allocator>
-__split_buffer<_Tp, _Allocator>&
-__split_buffer<_Tp, _Allocator>::operator=(__split_buffer&& __c)
-    _NOEXCEPT_((__alloc_traits::propagate_on_container_move_assignment::value &&
-                is_nothrow_move_assignable<allocator_type>::value) ||
-               !__alloc_traits::propagate_on_container_move_assignment::value)
-{
-    clear();
-    shrink_to_fit();
-    __first_ = __c.__first_;
-    __begin_ = __c.__begin_;
-    __end_ = __c.__end_;
-    __end_cap() = __c.__end_cap();
-    __move_assign_alloc(__c,
-        integral_constant<bool,
-                          __alloc_traits::propagate_on_container_move_assignment::value>());
-    __c.__first_ = __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr;
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-void
-__split_buffer<_Tp, _Allocator>::swap(__split_buffer& __x)
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value||
-                   __is_nothrow_swappable<__alloc_rr>::value)
-{
-    _VSTD::swap(__first_, __x.__first_);
-    _VSTD::swap(__begin_, __x.__begin_);
-    _VSTD::swap(__end_, __x.__end_);
-    _VSTD::swap(__end_cap(), __x.__end_cap());
-    __swap_allocator(__alloc(), __x.__alloc());
-}
-
-template <class _Tp, class _Allocator>
-void
-__split_buffer<_Tp, _Allocator>::reserve(size_type __n)
-{
-    if (__n < capacity())
-    {
-        __split_buffer<value_type, __alloc_rr&> __t(__n, 0, __alloc());
-        __t.__construct_at_end(move_iterator<pointer>(__begin_),
-                               move_iterator<pointer>(__end_));
-        _VSTD::swap(__first_, __t.__first_);
-        _VSTD::swap(__begin_, __t.__begin_);
-        _VSTD::swap(__end_, __t.__end_);
-        _VSTD::swap(__end_cap(), __t.__end_cap());
-    }
-}
-
-template <class _Tp, class _Allocator>
-void
-__split_buffer<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
-{
-    if (capacity() > size())
-    {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            __split_buffer<value_type, __alloc_rr&> __t(size(), 0, __alloc());
-            __t.__construct_at_end(move_iterator<pointer>(__begin_),
-                                   move_iterator<pointer>(__end_));
-            __t.__end_ = __t.__begin_ + (__end_ - __begin_);
-            _VSTD::swap(__first_, __t.__first_);
-            _VSTD::swap(__begin_, __t.__begin_);
-            _VSTD::swap(__end_, __t.__end_);
-            _VSTD::swap(__end_cap(), __t.__end_cap());
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template <class _Tp, class _Allocator>
-void
-__split_buffer<_Tp, _Allocator>::push_front(const_reference __x)
-{
-    if (__begin_ == __first_)
-    {
-        if (__end_ < __end_cap())
-        {
-            difference_type __d = __end_cap() - __end_;
-            __d = (__d + 1) / 2;
-            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d);
-            __end_ += __d;
-        }
-        else
-        {
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
-            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc());
-            __t.__construct_at_end(move_iterator<pointer>(__begin_),
-                                   move_iterator<pointer>(__end_));
-            _VSTD::swap(__first_, __t.__first_);
-            _VSTD::swap(__begin_, __t.__begin_);
-            _VSTD::swap(__end_, __t.__end_);
-            _VSTD::swap(__end_cap(), __t.__end_cap());
-        }
-    }
-    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__begin_-1), __x);
-    --__begin_;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-void
-__split_buffer<_Tp, _Allocator>::push_front(value_type&& __x)
-{
-    if (__begin_ == __first_)
-    {
-        if (__end_ < __end_cap())
-        {
-            difference_type __d = __end_cap() - __end_;
-            __d = (__d + 1) / 2;
-            __begin_ = _VSTD::move_backward(__begin_, __end_, __end_ + __d);
-            __end_ += __d;
-        }
-        else
-        {
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
-            __split_buffer<value_type, __alloc_rr&> __t(__c, (__c + 3) / 4, __alloc());
-            __t.__construct_at_end(move_iterator<pointer>(__begin_),
-                                   move_iterator<pointer>(__end_));
-            _VSTD::swap(__first_, __t.__first_);
-            _VSTD::swap(__begin_, __t.__begin_);
-            _VSTD::swap(__end_, __t.__end_);
-            _VSTD::swap(__end_cap(), __t.__end_cap());
-        }
-    }
-    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__begin_-1),
-            _VSTD::move(__x));
-    --__begin_;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__split_buffer<_Tp, _Allocator>::push_back(const_reference __x)
-{
-    if (__end_ == __end_cap())
-    {
-        if (__begin_ > __first_)
-        {
-            difference_type __d = __begin_ - __first_;
-            __d = (__d + 1) / 2;
-            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
-            __begin_ -= __d;
-        }
-        else
-        {
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
-            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
-            __t.__construct_at_end(move_iterator<pointer>(__begin_),
-                                   move_iterator<pointer>(__end_));
-            _VSTD::swap(__first_, __t.__first_);
-            _VSTD::swap(__begin_, __t.__begin_);
-            _VSTD::swap(__end_, __t.__end_);
-            _VSTD::swap(__end_cap(), __t.__end_cap());
-        }
-    }
-    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__end_), __x);
-    ++__end_;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-void
-__split_buffer<_Tp, _Allocator>::push_back(value_type&& __x)
-{
-    if (__end_ == __end_cap())
-    {
-        if (__begin_ > __first_)
-        {
-            difference_type __d = __begin_ - __first_;
-            __d = (__d + 1) / 2;
-            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
-            __begin_ -= __d;
-        }
-        else
-        {
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
-            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
-            __t.__construct_at_end(move_iterator<pointer>(__begin_),
-                                   move_iterator<pointer>(__end_));
-            _VSTD::swap(__first_, __t.__first_);
-            _VSTD::swap(__begin_, __t.__begin_);
-            _VSTD::swap(__end_, __t.__end_);
-            _VSTD::swap(__end_cap(), __t.__end_cap());
-        }
-    }
-    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__end_),
-            _VSTD::move(__x));
-    ++__end_;
-}
-
-template <class _Tp, class _Allocator>
-template <class... _Args>
-void
-__split_buffer<_Tp, _Allocator>::emplace_back(_Args&&... __args)
-{
-    if (__end_ == __end_cap())
-    {
-        if (__begin_ > __first_)
-        {
-            difference_type __d = __begin_ - __first_;
-            __d = (__d + 1) / 2;
-            __end_ = _VSTD::move(__begin_, __end_, __begin_ - __d);
-            __begin_ -= __d;
-        }
-        else
-        {
-            size_type __c = max<size_type>(2 * static_cast<size_t>(__end_cap() - __first_), 1);
-            __split_buffer<value_type, __alloc_rr&> __t(__c, __c / 4, __alloc());
-            __t.__construct_at_end(move_iterator<pointer>(__begin_),
-                                   move_iterator<pointer>(__end_));
-            _VSTD::swap(__first_, __t.__first_);
-            _VSTD::swap(__begin_, __t.__begin_);
-            _VSTD::swap(__end_, __t.__end_);
-            _VSTD::swap(__end_cap(), __t.__end_cap());
-        }
-    }
-    __alloc_traits::construct(__alloc(), _VSTD::__to_raw_pointer(__end_),
-                              _VSTD::forward<_Args>(__args)...);
-    ++__end_;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__split_buffer<_Tp, _Allocator>& __x, __split_buffer<_Tp, _Allocator>& __y)
-        _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_SPLIT_BUFFER
diff --git a/lib/libcxx/include/__sso_allocator b/lib/libcxx/include/__sso_allocator
deleted file mode 100644
index 8aca0495d75..00000000000
--- a/lib/libcxx/include/__sso_allocator
+++ /dev/null
@@ -1,77 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___SSO_ALLOCATOR
-#define _LIBCPP___SSO_ALLOCATOR
-
-#include <__config>
-#include <type_traits>
-#include <new>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp, size_t _Np> class _LIBCPP_HIDDEN __sso_allocator;
-
-template <size_t _Np>
-class _LIBCPP_HIDDEN __sso_allocator<void, _Np>
-{
-public:
-    typedef const void*       const_pointer;
-    typedef void              value_type;
-};
-
-template <class _Tp, size_t _Np>
-class _LIBCPP_HIDDEN __sso_allocator
-{
-    typename aligned_storage<sizeof(_Tp) * _Np>::type buf_;
-    bool __allocated_;
-public:
-    typedef size_t            size_type;
-    typedef _Tp*              pointer;
-    typedef _Tp               value_type;
-
-    _LIBCPP_INLINE_VISIBILITY __sso_allocator() throw() : __allocated_(false) {}
-    _LIBCPP_INLINE_VISIBILITY __sso_allocator(const __sso_allocator&) throw() : __allocated_(false) {}
-    template <class _Up> _LIBCPP_INLINE_VISIBILITY __sso_allocator(const __sso_allocator<_Up, _Np>&) throw()
-         : __allocated_(false) {}
-private:
-    __sso_allocator& operator=(const __sso_allocator&);
-public:
-    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, typename __sso_allocator<void, _Np>::const_pointer = 0)
-    {
-        if (!__allocated_ && __n <= _Np)
-        {
-            __allocated_ = true;
-            return (pointer)&buf_;
-        }
-        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
-    }
-    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n)
-    {
-        if (__p == (pointer)&buf_)
-            __allocated_ = false;
-        else
-            _VSTD::__libcpp_deallocate(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
-    }
-    _LIBCPP_INLINE_VISIBILITY size_type max_size() const throw() {return size_type(~0) / sizeof(_Tp);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator==(__sso_allocator& __a) const {return &buf_ == &__a.buf_;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(__sso_allocator& __a) const {return &buf_ != &__a.buf_;}
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP___SSO_ALLOCATOR
diff --git a/lib/libcxx/include/__std_stream b/lib/libcxx/include/__std_stream
deleted file mode 100644
index db90795f66f..00000000000
--- a/lib/libcxx/include/__std_stream
+++ /dev/null
@@ -1,362 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___STD_STREAM
-#define _LIBCPP___STD_STREAM
-
-#include <__config>
-#include <ostream>
-#include <istream>
-#include <__locale>
-#include <cstdio>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-static const int __limit = 8;
-
-// __stdinbuf
-
-template <class _CharT>
-class _LIBCPP_HIDDEN __stdinbuf
-    : public basic_streambuf<_CharT, char_traits<_CharT> >
-{
-public:
-    typedef _CharT                           char_type;
-    typedef char_traits<char_type>           traits_type;
-    typedef typename traits_type::int_type   int_type;
-    typedef typename traits_type::pos_type   pos_type;
-    typedef typename traits_type::off_type   off_type;
-    typedef typename traits_type::state_type state_type;
-
-    __stdinbuf(FILE* __fp, state_type* __st);
-
-protected:
-    virtual int_type underflow();
-    virtual int_type uflow();
-    virtual int_type pbackfail(int_type __c = traits_type::eof());
-    virtual void imbue(const locale& __loc);
-
-private:
-
-    FILE* __file_;
-    const codecvt<char_type, char, state_type>* __cv_;
-    state_type* __st_;
-    int __encoding_;
-    int_type __last_consumed_;
-    bool __last_consumed_is_next_;
-    bool __always_noconv_;
-
-    __stdinbuf(const __stdinbuf&);
-    __stdinbuf& operator=(const __stdinbuf&);
-
-    int_type __getchar(bool __consume);
-};
-
-template <class _CharT>
-__stdinbuf<_CharT>::__stdinbuf(FILE* __fp, state_type* __st)
-    : __file_(__fp),
-      __st_(__st),
-      __last_consumed_(traits_type::eof()),
-      __last_consumed_is_next_(false)
-{
-    imbue(this->getloc());
-}
-
-template <class _CharT>
-void
-__stdinbuf<_CharT>::imbue(const locale& __loc)
-{
-    __cv_ = &use_facet<codecvt<char_type, char, state_type> >(__loc);
-    __encoding_ = __cv_->encoding();
-    __always_noconv_ = __cv_->always_noconv();
-    if (__encoding_ > __limit)
-        __throw_runtime_error("unsupported locale for standard input");
-}
-
-template <class _CharT>
-typename __stdinbuf<_CharT>::int_type
-__stdinbuf<_CharT>::underflow()
-{
-    return __getchar(false);
-}
-
-template <class _CharT>
-typename __stdinbuf<_CharT>::int_type
-__stdinbuf<_CharT>::uflow()
-{
-    return __getchar(true);
-}
-
-template <class _CharT>
-typename __stdinbuf<_CharT>::int_type
-__stdinbuf<_CharT>::__getchar(bool __consume)
-{
-    if (__last_consumed_is_next_)
-    {
-        int_type __result = __last_consumed_;
-        if (__consume)
-        {
-            __last_consumed_ = traits_type::eof();
-            __last_consumed_is_next_ = false;
-        }
-        return __result;
-    }
-    char __extbuf[__limit];
-    int __nread = _VSTD::max(1, __encoding_);
-    for (int __i = 0; __i < __nread; ++__i)
-    {
-        int __c = getc(__file_);
-        if (__c == EOF)
-            return traits_type::eof();
-        __extbuf[__i] = static_cast<char>(__c);
-    }
-    char_type __1buf;
-    if (__always_noconv_)
-        __1buf = static_cast<char_type>(__extbuf[0]);
-    else
-    {
-        const char* __enxt;
-        char_type* __inxt;
-        codecvt_base::result __r;
-        do
-        {
-            state_type __sv_st = *__st_;
-            __r = __cv_->in(*__st_, __extbuf, __extbuf + __nread, __enxt,
-                                   &__1buf, &__1buf + 1, __inxt);
-            switch (__r)
-            {
-            case _VSTD::codecvt_base::ok:
-                break;
-            case codecvt_base::partial:
-                *__st_ = __sv_st;
-                if (__nread == sizeof(__extbuf))
-                    return traits_type::eof();
-                {
-                    int __c = getc(__file_);
-                    if (__c == EOF)
-                        return traits_type::eof();
-                    __extbuf[__nread] = static_cast<char>(__c);
-                }
-                ++__nread;
-                break;
-            case codecvt_base::error:
-                return traits_type::eof();
-            case _VSTD::codecvt_base::noconv:
-                __1buf = static_cast<char_type>(__extbuf[0]);
-                break;
-            }
-        } while (__r == _VSTD::codecvt_base::partial);
-    }
-    if (!__consume)
-    {
-        for (int __i = __nread; __i > 0;)
-        {
-            if (ungetc(traits_type::to_int_type(__extbuf[--__i]), __file_) == EOF)
-                return traits_type::eof();
-        }
-    }
-    else
-        __last_consumed_ = traits_type::to_int_type(__1buf);
-    return traits_type::to_int_type(__1buf);
-}
-
-template <class _CharT>
-typename __stdinbuf<_CharT>::int_type
-__stdinbuf<_CharT>::pbackfail(int_type __c)
-{
-    if (traits_type::eq_int_type(__c, traits_type::eof()))
-    {
-        if (!__last_consumed_is_next_)
-        {
-            __c = __last_consumed_;
-            __last_consumed_is_next_ = !traits_type::eq_int_type(__last_consumed_,
-                                                                 traits_type::eof());
-        }
-        return __c;
-    }
-    if (__last_consumed_is_next_)
-    {
-        char __extbuf[__limit];
-        char* __enxt;
-        const char_type __ci = traits_type::to_char_type(__last_consumed_);
-        const char_type* __inxt;
-        switch (__cv_->out(*__st_, &__ci, &__ci + 1, __inxt,
-                                  __extbuf, __extbuf + sizeof(__extbuf), __enxt))
-        {
-        case _VSTD::codecvt_base::ok:
-            break;
-        case _VSTD::codecvt_base::noconv:
-            __extbuf[0] = static_cast<char>(__last_consumed_);
-            __enxt = __extbuf + 1;
-            break;
-        case codecvt_base::partial:
-        case codecvt_base::error:
-            return traits_type::eof();
-        }
-        while (__enxt > __extbuf)
-            if (ungetc(*--__enxt, __file_) == EOF)
-                return traits_type::eof();
-    }
-    __last_consumed_ = __c;
-    __last_consumed_is_next_ = true;
-    return __c;
-}
-
-// __stdoutbuf
-
-template <class _CharT>
-class _LIBCPP_HIDDEN __stdoutbuf
-    : public basic_streambuf<_CharT, char_traits<_CharT> >
-{
-public:
-    typedef _CharT                           char_type;
-    typedef char_traits<char_type>           traits_type;
-    typedef typename traits_type::int_type   int_type;
-    typedef typename traits_type::pos_type   pos_type;
-    typedef typename traits_type::off_type   off_type;
-    typedef typename traits_type::state_type state_type;
-
-    __stdoutbuf(FILE* __fp, state_type* __st);
-
-protected:
-    virtual int_type overflow (int_type __c = traits_type::eof());
-    virtual streamsize xsputn(const char_type* __s, streamsize __n);
-    virtual int sync();
-    virtual void imbue(const locale& __loc);
-
-private:
-    FILE* __file_;
-    const codecvt<char_type, char, state_type>* __cv_;
-    state_type* __st_;
-    bool __always_noconv_;
-
-    __stdoutbuf(const __stdoutbuf&);
-    __stdoutbuf& operator=(const __stdoutbuf&);
-};
-
-template <class _CharT>
-__stdoutbuf<_CharT>::__stdoutbuf(FILE* __fp, state_type* __st)
-    : __file_(__fp),
-      __cv_(&use_facet<codecvt<char_type, char, state_type> >(this->getloc())),
-      __st_(__st),
-      __always_noconv_(__cv_->always_noconv())
-{
-}
-
-template <class _CharT>
-typename __stdoutbuf<_CharT>::int_type
-__stdoutbuf<_CharT>::overflow(int_type __c)
-{
-    char __extbuf[__limit];
-    char_type __1buf;
-    if (!traits_type::eq_int_type(__c, traits_type::eof()))
-    {
-        __1buf = traits_type::to_char_type(__c);
-        if (__always_noconv_)
-        {
-            if (fwrite(&__1buf, sizeof(char_type), 1, __file_) != 1)
-                return traits_type::eof();
-        }
-        else
-        {
-            char* __extbe = __extbuf;
-            codecvt_base::result __r;
-            char_type* pbase = &__1buf;
-            char_type* pptr = pbase + 1;
-            do
-            {
-                const char_type* __e;
-                __r = __cv_->out(*__st_, pbase, pptr, __e,
-                                        __extbuf,
-                                        __extbuf + sizeof(__extbuf),
-                                        __extbe);
-                if (__e == pbase)
-                    return traits_type::eof();
-                if (__r == codecvt_base::noconv)
-                {
-                    if (fwrite(pbase, 1, 1, __file_) != 1)
-                        return traits_type::eof();
-                }
-                else if (__r == codecvt_base::ok || __r == codecvt_base::partial)
-                {
-                    size_t __nmemb = static_cast<size_t>(__extbe - __extbuf);
-                    if (fwrite(__extbuf, 1, __nmemb, __file_) != __nmemb)
-                        return traits_type::eof();
-                    if (__r == codecvt_base::partial)
-                    {
-                        pbase = const_cast<char_type*>(__e);
-                    }
-                }
-                else
-                    return traits_type::eof();
-            } while (__r == codecvt_base::partial);
-        }
-    }
-    return traits_type::not_eof(__c);
-}
-
-template <class _CharT>
-streamsize
-__stdoutbuf<_CharT>::xsputn(const char_type* __s, streamsize __n)
-{
-    if (__always_noconv_)
-        return fwrite(__s, sizeof(char_type), __n, __file_);
-    streamsize __i = 0;
-    for (; __i < __n; ++__i, ++__s)
-        if (overflow(traits_type::to_int_type(*__s)) == traits_type::eof())
-            break;
-    return __i;
-}
-
-template <class _CharT>
-int
-__stdoutbuf<_CharT>::sync()
-{
-    char __extbuf[__limit];
-    codecvt_base::result __r;
-    do
-    {
-        char* __extbe;
-        __r = __cv_->unshift(*__st_, __extbuf,
-                                    __extbuf + sizeof(__extbuf),
-                                    __extbe);
-        size_t __nmemb = static_cast<size_t>(__extbe - __extbuf);
-        if (fwrite(__extbuf, 1, __nmemb, __file_) != __nmemb)
-            return -1;
-    } while (__r == codecvt_base::partial);
-    if (__r == codecvt_base::error)
-        return -1;
-    if (fflush(__file_))
-        return -1;
-    return 0;
-}
-
-template <class _CharT>
-void
-__stdoutbuf<_CharT>::imbue(const locale& __loc)
-{
-    sync();
-    __cv_ = &use_facet<codecvt<char_type, char, state_type> >(__loc);
-    __always_noconv_ = __cv_->always_noconv();
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP___STD_STREAM
diff --git a/lib/libcxx/include/__string b/lib/libcxx/include/__string
deleted file mode 100644
index 1ddeec7149f..00000000000
--- a/lib/libcxx/include/__string
+++ /dev/null
@@ -1,974 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- __string ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___STRING
-#define _LIBCPP___STRING
-
-/*
-    string synopsis
-
-namespace std
-{
-
-template <class charT>
-struct char_traits
-{
-    typedef charT     char_type;
-    typedef ...       int_type;
-    typedef streamoff off_type;
-    typedef streampos pos_type;
-    typedef mbstate_t state_type;
-
-    static constexpr void assign(char_type& c1, const char_type& c2) noexcept;
-    static constexpr bool eq(char_type c1, char_type c2) noexcept;
-    static constexpr bool lt(char_type c1, char_type c2) noexcept;
-
-    static constexpr int    compare(const char_type* s1, const char_type* s2, size_t n);
-    static constexpr size_t length(const char_type* s);
-    static constexpr const char_type* 
-                            find(const char_type* s, size_t n, const char_type& a);
-    static char_type*       move(char_type* s1, const char_type* s2, size_t n);
-    static char_type*       copy(char_type* s1, const char_type* s2, size_t n);
-    static char_type*       assign(char_type* s, size_t n, char_type a);
-
-    static constexpr int_type  not_eof(int_type c) noexcept;
-    static constexpr char_type to_char_type(int_type c) noexcept;
-    static constexpr int_type  to_int_type(char_type c) noexcept;
-    static constexpr bool      eq_int_type(int_type c1, int_type c2) noexcept;
-    static constexpr int_type  eof() noexcept;
-};
-
-template <> struct char_traits<char>;
-template <> struct char_traits<wchar_t>;
-template <> struct char_traits<char8_t>;  // c++20
-
-}  // std
-
-*/
-
-#include <__config>
-#include <algorithm>  // for search and min
-#include <cstdio>     // For EOF.
-#include <memory>     // for __murmur2_or_cityhash
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// char_traits
-
-template <class _CharT>
-struct _LIBCPP_TEMPLATE_VIS char_traits
-{
-    typedef _CharT    char_type;
-    typedef int       int_type;
-    typedef streamoff off_type;
-    typedef streampos pos_type;
-    typedef mbstate_t state_type;
-
-    static inline void _LIBCPP_CONSTEXPR_AFTER_CXX14
-        assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
-    static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
-        {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
-        {return __c1 < __c2;}
-
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    int compare(const char_type* __s1, const char_type* __s2, size_t __n);
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    size_t length(const char_type* __s);
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const char_type* find(const char_type* __s, size_t __n, const char_type& __a);
-    static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n);
-    _LIBCPP_INLINE_VISIBILITY
-    static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n);
-    _LIBCPP_INLINE_VISIBILITY
-    static char_type*       assign(char_type* __s, size_t __n, char_type __a);
-
-    static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
-        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
-    static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
-        {return char_type(__c);}
-    static inline _LIBCPP_CONSTEXPR int_type  to_int_type(char_type __c) _NOEXCEPT
-        {return int_type(__c);}
-    static inline _LIBCPP_CONSTEXPR bool      eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
-        {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR int_type  eof() _NOEXCEPT
-        {return int_type(EOF);}
-};
-
-template <class _CharT>
-_LIBCPP_CONSTEXPR_AFTER_CXX14 int
-char_traits<_CharT>::compare(const char_type* __s1, const char_type* __s2, size_t __n)
-{
-    for (; __n; --__n, ++__s1, ++__s2)
-    {
-        if (lt(*__s1, *__s2))
-            return -1;
-        if (lt(*__s2, *__s1))
-            return 1;
-    }
-    return 0;
-}
-
-template <class _CharT>
-inline
-_LIBCPP_CONSTEXPR_AFTER_CXX14 size_t
-char_traits<_CharT>::length(const char_type* __s)
-{
-    size_t __len = 0;
-    for (; !eq(*__s, char_type(0)); ++__s)
-        ++__len;
-    return __len;
-}
-
-template <class _CharT>
-inline
-_LIBCPP_CONSTEXPR_AFTER_CXX14 const _CharT*
-char_traits<_CharT>::find(const char_type* __s, size_t __n, const char_type& __a)
-{
-    for (; __n; --__n)
-    {
-        if (eq(*__s, __a))
-            return __s;
-        ++__s;
-    }
-    return 0;
-}
-
-template <class _CharT>
-_CharT*
-char_traits<_CharT>::move(char_type* __s1, const char_type* __s2, size_t __n)
-{
-    char_type* __r = __s1;
-    if (__s1 < __s2)
-    {
-        for (; __n; --__n, ++__s1, ++__s2)
-            assign(*__s1, *__s2);
-    }
-    else if (__s2 < __s1)
-    {
-        __s1 += __n;
-        __s2 += __n;
-        for (; __n; --__n)
-            assign(*--__s1, *--__s2);
-    }
-    return __r;
-}
-
-template <class _CharT>
-inline
-_CharT*
-char_traits<_CharT>::copy(char_type* __s1, const char_type* __s2, size_t __n)
-{
-    _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
-    char_type* __r = __s1;
-    for (; __n; --__n, ++__s1, ++__s2)
-        assign(*__s1, *__s2);
-    return __r;
-}
-
-template <class _CharT>
-inline
-_CharT*
-char_traits<_CharT>::assign(char_type* __s, size_t __n, char_type __a)
-{
-    char_type* __r = __s;
-    for (; __n; --__n, ++__s)
-        assign(*__s, __a);
-    return __r;
-}
-
-// char_traits<char>
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS char_traits<char>
-{
-    typedef char      char_type;
-    typedef int       int_type;
-    typedef streamoff off_type;
-    typedef streampos pos_type;
-    typedef mbstate_t state_type;
-
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-    void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
-    static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
-            {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
-        {return (unsigned char)__c1 < (unsigned char)__c2;}
-
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    static inline size_t _LIBCPP_CONSTEXPR_AFTER_CXX14
-    length(const char_type* __s)  _NOEXCEPT {return __builtin_strlen(__s);}
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
-    static inline char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-        {return __n == 0 ? __s1 : (char_type*) memmove(__s1, __s2, __n);}
-    static inline char_type* copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-        {
-            _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
-            return __n == 0 ? __s1 : (char_type*)memcpy(__s1, __s2, __n);
-        }
-    static inline char_type* assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT
-        {return __n == 0 ? __s : (char_type*)memset(__s, to_int_type(__a), __n);}
-
-    static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
-        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
-    static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
-        {return char_type(__c);}
-    static inline _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT
-        {return int_type((unsigned char)__c);}
-    static inline _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
-        {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR int_type  eof() _NOEXCEPT
-        {return int_type(EOF);}
-};
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-int
-char_traits<char>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-{
-    if (__n == 0)
-        return 0;
-#if __has_feature(cxx_constexpr_string_builtins)
-    return __builtin_memcmp(__s1, __s2, __n);
-#elif _LIBCPP_STD_VER <= 14
-    return memcmp(__s1, __s2, __n);
-#else
-    for (; __n; --__n, ++__s1, ++__s2)
-    {
-        if (lt(*__s1, *__s2))
-            return -1;
-        if (lt(*__s2, *__s1))
-            return 1;
-    }
-    return 0;
-#endif
-}
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-const char*
-char_traits<char>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
-{
-    if (__n == 0)
-        return nullptr;
-#if __has_feature(cxx_constexpr_string_builtins)
-    return __builtin_char_memchr(__s, to_int_type(__a), __n);
-#elif _LIBCPP_STD_VER <= 14
-    return (const char_type*) memchr(__s, to_int_type(__a), __n);
-#else
-    for (; __n; --__n)
-    {
-        if (eq(*__s, __a))
-            return __s;
-        ++__s;
-    }
-    return nullptr;
-#endif
-}
-
-
-// char_traits<wchar_t>
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS char_traits<wchar_t>
-{
-    typedef wchar_t   char_type;
-    typedef wint_t    int_type;
-    typedef streamoff off_type;
-    typedef streampos pos_type;
-    typedef mbstate_t state_type;
-
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-    void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
-    static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
-        {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
-        {return __c1 < __c2;}
-
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    int compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    size_t length(const char_type* __s) _NOEXCEPT;
-    static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
-    static inline char_type* move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-        {return __n == 0 ? __s1 : (char_type*)wmemmove(__s1, __s2, __n);}
-    static inline char_type* copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-        {
-            _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
-            return __n == 0 ? __s1 : (char_type*)wmemcpy(__s1, __s2, __n);
-        }
-    static inline char_type* assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT
-        {return __n == 0 ? __s : (char_type*)wmemset(__s, __a, __n);}
-
-    static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
-        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
-    static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
-        {return char_type(__c);}
-    static inline _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT
-        {return int_type(__c);}
-    static inline _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
-        {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT
-        {return int_type(WEOF);}
-};
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-int
-char_traits<wchar_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-{
-    if (__n == 0)
-        return 0;
-#if __has_feature(cxx_constexpr_string_builtins)
-    return __builtin_wmemcmp(__s1, __s2, __n);
-#elif _LIBCPP_STD_VER <= 14
-    return wmemcmp(__s1, __s2, __n);
-#else
-    for (; __n; --__n, ++__s1, ++__s2)
-    {
-        if (lt(*__s1, *__s2))
-            return -1;
-        if (lt(*__s2, *__s1))
-            return 1;
-    }
-    return 0;
-#endif
-}
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-size_t
-char_traits<wchar_t>::length(const char_type* __s) _NOEXCEPT
-{
-#if __has_feature(cxx_constexpr_string_builtins)
-    return __builtin_wcslen(__s);
-#elif _LIBCPP_STD_VER <= 14
-    return wcslen(__s);
-#else
-    size_t __len = 0;
-    for (; !eq(*__s, char_type(0)); ++__s)
-        ++__len;
-    return __len;
-#endif
-}
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-const wchar_t*
-char_traits<wchar_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
-{
-    if (__n == 0)
-        return nullptr;
-#if __has_feature(cxx_constexpr_string_builtins)
-    return __builtin_wmemchr(__s, __a, __n);
-#elif _LIBCPP_STD_VER <= 14
-    return wmemchr(__s, __a, __n);
-#else
-    for (; __n; --__n)
-    {
-        if (eq(*__s, __a))
-            return __s;
-        ++__s;
-    }
-    return nullptr;
-#endif
-}
-
-
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS char_traits<char8_t>
-{
-    typedef char8_t        char_type;
-    typedef unsigned int   int_type;
-    typedef streamoff      off_type;
-    typedef u8streampos    pos_type;
-    typedef mbstate_t      state_type;
-
-    static inline constexpr void assign(char_type& __c1, const char_type& __c2) noexcept
-        {__c1 = __c2;}
-    static inline constexpr bool eq(char_type __c1, char_type __c2) noexcept
-        {return __c1 == __c2;}
-    static inline constexpr bool lt(char_type __c1, char_type __c2) noexcept
-        {return __c1 < __c2;}
-
-    static constexpr
-    int              compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-
-    static constexpr
-    size_t           length(const char_type* __s) _NOEXCEPT;
- 
-    _LIBCPP_INLINE_VISIBILITY static constexpr
-    const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
- 
-    static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-        {return __n == 0 ? __s1 : (char_type*) memmove(__s1, __s2, __n);}
- 
-    static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-       {
-            _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
-            return __n == 0 ? __s1 : (char_type*)memcpy(__s1, __s2, __n);
-       }
- 
-    static char_type*       assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT
-        {return __n == 0 ? __s : (char_type*)memset(__s, to_int_type(__a), __n);}
-
-    static inline constexpr int_type  not_eof(int_type __c) noexcept
-        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
-    static inline constexpr char_type to_char_type(int_type __c) noexcept
-        {return char_type(__c);}
-    static inline constexpr int_type to_int_type(char_type __c) noexcept
-        {return int_type(__c);}
-    static inline constexpr bool eq_int_type(int_type __c1, int_type __c2) noexcept
-        {return __c1 == __c2;}
-    static inline constexpr int_type eof() noexcept
-        {return int_type(EOF);}
-};
-
-// TODO use '__builtin_strlen' if it ever supports char8_t ??
-inline constexpr
-size_t
-char_traits<char8_t>::length(const char_type* __s) _NOEXCEPT
-{
-    size_t __len = 0;
-    for (; !eq(*__s, char_type(0)); ++__s)
-        ++__len;
-    return __len;
-}
-
-inline constexpr
-int
-char_traits<char8_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-{
-#if __has_feature(cxx_constexpr_string_builtins)
-    return __builtin_memcmp(__s1, __s2, __n);
-#else
-    for (; __n; --__n, ++__s1, ++__s2)
-    {
-        if (lt(*__s1, *__s2))
-            return -1;
-        if (lt(*__s2, *__s1))
-            return 1;
-    }
-    return 0;
-#endif
-}
-
-// TODO use '__builtin_char_memchr' if it ever supports char8_t ??
-inline constexpr
-const char8_t*
-char_traits<char8_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
-{
-    for (; __n; --__n)
-    {
-        if (eq(*__s, __a))
-            return __s;
-        ++__s;
-    }
-    return 0;
-}
-
-#endif // #_LIBCPP_NO_HAS_CHAR8_T
-
-#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS char_traits<char16_t>
-{
-    typedef char16_t       char_type;
-    typedef uint_least16_t int_type;
-    typedef streamoff      off_type;
-    typedef u16streampos   pos_type;
-    typedef mbstate_t      state_type;
-
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-    void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
-    static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
-        {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
-        {return __c1 < __c2;}
-
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    int              compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    size_t           length(const char_type* __s) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    static char_type*       assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT;
-
-    static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
-        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
-    static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
-        {return char_type(__c);}
-    static inline _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT
-        {return int_type(__c);}
-    static inline _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
-        {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT
-        {return int_type(0xFFFF);}
-};
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-int
-char_traits<char16_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-{
-    for (; __n; --__n, ++__s1, ++__s2)
-    {
-        if (lt(*__s1, *__s2))
-            return -1;
-        if (lt(*__s2, *__s1))
-            return 1;
-    }
-    return 0;
-}
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-size_t
-char_traits<char16_t>::length(const char_type* __s) _NOEXCEPT
-{
-    size_t __len = 0;
-    for (; !eq(*__s, char_type(0)); ++__s)
-        ++__len;
-    return __len;
-}
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-const char16_t*
-char_traits<char16_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
-{
-    for (; __n; --__n)
-    {
-        if (eq(*__s, __a))
-            return __s;
-        ++__s;
-    }
-    return 0;
-}
-
-inline
-char16_t*
-char_traits<char16_t>::move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-{
-    char_type* __r = __s1;
-    if (__s1 < __s2)
-    {
-        for (; __n; --__n, ++__s1, ++__s2)
-            assign(*__s1, *__s2);
-    }
-    else if (__s2 < __s1)
-    {
-        __s1 += __n;
-        __s2 += __n;
-        for (; __n; --__n)
-            assign(*--__s1, *--__s2);
-    }
-    return __r;
-}
-
-inline
-char16_t*
-char_traits<char16_t>::copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
-    char_type* __r = __s1;
-    for (; __n; --__n, ++__s1, ++__s2)
-        assign(*__s1, *__s2);
-    return __r;
-}
-
-inline
-char16_t*
-char_traits<char16_t>::assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT
-{
-    char_type* __r = __s;
-    for (; __n; --__n, ++__s)
-        assign(*__s, __a);
-    return __r;
-}
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS char_traits<char32_t>
-{
-    typedef char32_t       char_type;
-    typedef uint_least32_t int_type;
-    typedef streamoff      off_type;
-    typedef u32streampos   pos_type;
-    typedef mbstate_t      state_type;
-
-    static inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-    void assign(char_type& __c1, const char_type& __c2) _NOEXCEPT {__c1 = __c2;}
-    static inline _LIBCPP_CONSTEXPR bool eq(char_type __c1, char_type __c2) _NOEXCEPT
-        {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR bool lt(char_type __c1, char_type __c2) _NOEXCEPT
-        {return __c1 < __c2;}
-
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    int              compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    size_t           length(const char_type* __s) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const char_type* find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    static char_type*       move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    static char_type*       copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    static char_type*       assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT;
-
-    static inline _LIBCPP_CONSTEXPR int_type  not_eof(int_type __c) _NOEXCEPT
-        {return eq_int_type(__c, eof()) ? ~eof() : __c;}
-    static inline _LIBCPP_CONSTEXPR char_type to_char_type(int_type __c) _NOEXCEPT
-        {return char_type(__c);}
-    static inline _LIBCPP_CONSTEXPR int_type to_int_type(char_type __c) _NOEXCEPT
-        {return int_type(__c);}
-    static inline _LIBCPP_CONSTEXPR bool eq_int_type(int_type __c1, int_type __c2) _NOEXCEPT
-        {return __c1 == __c2;}
-    static inline _LIBCPP_CONSTEXPR int_type eof() _NOEXCEPT
-        {return int_type(0xFFFFFFFF);}
-};
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-int
-char_traits<char32_t>::compare(const char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-{
-    for (; __n; --__n, ++__s1, ++__s2)
-    {
-        if (lt(*__s1, *__s2))
-            return -1;
-        if (lt(*__s2, *__s1))
-            return 1;
-    }
-    return 0;
-}
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-size_t
-char_traits<char32_t>::length(const char_type* __s) _NOEXCEPT
-{
-    size_t __len = 0;
-    for (; !eq(*__s, char_type(0)); ++__s)
-        ++__len;
-    return __len;
-}
-
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-const char32_t*
-char_traits<char32_t>::find(const char_type* __s, size_t __n, const char_type& __a) _NOEXCEPT
-{
-    for (; __n; --__n)
-    {
-        if (eq(*__s, __a))
-            return __s;
-        ++__s;
-    }
-    return 0;
-}
-
-inline
-char32_t*
-char_traits<char32_t>::move(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-{
-    char_type* __r = __s1;
-    if (__s1 < __s2)
-    {
-        for (; __n; --__n, ++__s1, ++__s2)
-            assign(*__s1, *__s2);
-    }
-    else if (__s2 < __s1)
-    {
-        __s1 += __n;
-        __s2 += __n;
-        for (; __n; --__n)
-            assign(*--__s1, *--__s2);
-    }
-    return __r;
-}
-
-inline
-char32_t*
-char_traits<char32_t>::copy(char_type* __s1, const char_type* __s2, size_t __n) _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s2 < __s1 || __s2 >= __s1+__n, "char_traits::copy overlapped range");
-    char_type* __r = __s1;
-    for (; __n; --__n, ++__s1, ++__s2)
-        assign(*__s1, *__s2);
-    return __r;
-}
-
-inline
-char32_t*
-char_traits<char32_t>::assign(char_type* __s, size_t __n, char_type __a) _NOEXCEPT
-{
-    char_type* __r = __s;
-    for (; __n; --__n, ++__s)
-        assign(*__s, __a);
-    return __r;
-}
-
-#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
-
-// helper fns for basic_string and string_view
-
-// __str_find
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_find(const _CharT *__p, _SizeT __sz, 
-             _CharT __c, _SizeT __pos) _NOEXCEPT
-{
-    if (__pos >= __sz)
-        return __npos;
-    const _CharT* __r = _Traits::find(__p + __pos, __sz - __pos, __c);
-    if (__r == 0)
-        return __npos;
-    return static_cast<_SizeT>(__r - __p);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX11 const _CharT *
-__search_substring(const _CharT *__first1, const _CharT *__last1,
-                   const _CharT *__first2, const _CharT *__last2) {
-  // Take advantage of knowing source and pattern lengths.
-  // Stop short when source is smaller than pattern.
-  const ptrdiff_t __len2 = __last2 - __first2;
-  if (__len2 == 0)
-    return __first1;
-
-  ptrdiff_t __len1 = __last1 - __first1;
-  if (__len1 < __len2)
-    return __last1;
-
-  // First element of __first2 is loop invariant.
-  _CharT __f2 = *__first2;
-  while (true) {
-    __len1 = __last1 - __first1;
-    // Check whether __first1 still has at least __len2 bytes.
-    if (__len1 < __len2)
-      return __last1;
-
-    // Find __f2 the first byte matching in __first1.
-    __first1 = _Traits::find(__first1, __len1 - __len2 + 1, __f2);
-    if (__first1 == 0)
-      return __last1;
-
-    // It is faster to compare from the first byte of __first1 even if we
-    // already know that it matches the first byte of __first2: this is because
-    // __first2 is most likely aligned, as it is user's "pattern" string, and
-    // __first1 + 1 is most likely not aligned, as the match is in the middle of
-    // the string.
-    if (_Traits::compare(__first1, __first2, __len2) == 0)
-      return __first1;
-
-    ++__first1;
-  }
-}
-
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_find(const _CharT *__p, _SizeT __sz, 
-       const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
-{
-    if (__pos > __sz)
-        return __npos;
-
-    if (__n == 0) // There is nothing to search, just return __pos.
-        return __pos;
-
-    const _CharT *__r = __search_substring<_CharT, _Traits>(
-        __p + __pos, __p + __sz, __s, __s + __n);
-
-    if (__r == __p + __sz)
-        return __npos;
-    return static_cast<_SizeT>(__r - __p);
-}
-
-
-// __str_rfind
-
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_rfind(const _CharT *__p, _SizeT __sz, 
-              _CharT __c, _SizeT __pos) _NOEXCEPT
-{
-    if (__sz < 1)
-        return __npos;
-    if (__pos < __sz)
-        ++__pos;
-    else
-        __pos = __sz;
-    for (const _CharT* __ps = __p + __pos; __ps != __p;)
-    {
-        if (_Traits::eq(*--__ps, __c))
-            return static_cast<_SizeT>(__ps - __p);
-    }
-    return __npos;
-}
-
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_rfind(const _CharT *__p, _SizeT __sz, 
-        const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
-{
-    __pos = _VSTD::min(__pos, __sz);
-    if (__n < __sz - __pos)
-        __pos += __n;
-    else
-        __pos = __sz;
-    const _CharT* __r = _VSTD::__find_end(
-                  __p, __p + __pos, __s, __s + __n, _Traits::eq, 
-                        random_access_iterator_tag(), random_access_iterator_tag());
-    if (__n > 0 && __r == __p + __pos)
-        return __npos;
-    return static_cast<_SizeT>(__r - __p);
-}
-
-// __str_find_first_of
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_find_first_of(const _CharT *__p, _SizeT __sz,
-                const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
-{
-    if (__pos >= __sz || __n == 0)
-        return __npos;
-    const _CharT* __r = _VSTD::__find_first_of_ce
-        (__p + __pos, __p + __sz, __s, __s + __n, _Traits::eq );
-    if (__r == __p + __sz)
-        return __npos;
-    return static_cast<_SizeT>(__r - __p);
-}
-
-
-// __str_find_last_of
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_find_last_of(const _CharT *__p, _SizeT __sz,
-               const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
-    {
-    if (__n != 0)
-    {
-        if (__pos < __sz)
-            ++__pos;
-        else
-            __pos = __sz;
-        for (const _CharT* __ps = __p + __pos; __ps != __p;)
-        {
-            const _CharT* __r = _Traits::find(__s, __n, *--__ps);
-            if (__r)
-                return static_cast<_SizeT>(__ps - __p);
-        }
-    }
-    return __npos;
-}
-
-
-// __str_find_first_not_of
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_find_first_not_of(const _CharT *__p, _SizeT __sz,
-                    const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
-{
-    if (__pos < __sz)
-    {
-        const _CharT* __pe = __p + __sz;
-        for (const _CharT* __ps = __p + __pos; __ps != __pe; ++__ps)
-            if (_Traits::find(__s, __n, *__ps) == 0)
-                return static_cast<_SizeT>(__ps - __p);
-    }
-    return __npos;
-}
-
-
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_find_first_not_of(const _CharT *__p, _SizeT __sz,
-                          _CharT __c, _SizeT __pos) _NOEXCEPT
-{
-    if (__pos < __sz)
-    {
-        const _CharT* __pe = __p + __sz;
-        for (const _CharT* __ps = __p + __pos; __ps != __pe; ++__ps)
-            if (!_Traits::eq(*__ps, __c))
-                return static_cast<_SizeT>(__ps - __p);
-    }
-    return __npos;
-}
-
-
-// __str_find_last_not_of
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_find_last_not_of(const _CharT *__p, _SizeT __sz,
-                   const _CharT* __s, _SizeT __pos, _SizeT __n) _NOEXCEPT
-{
-    if (__pos < __sz)
-        ++__pos;
-    else
-        __pos = __sz;
-    for (const _CharT* __ps = __p + __pos; __ps != __p;)
-        if (_Traits::find(__s, __n, *--__ps) == 0)
-            return static_cast<_SizeT>(__ps - __p);
-    return __npos;
-}
-
-
-template<class _CharT, class _SizeT, class _Traits, _SizeT __npos>
-inline _SizeT _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-__str_find_last_not_of(const _CharT *__p, _SizeT __sz,
-                         _CharT __c, _SizeT __pos) _NOEXCEPT
-{
-    if (__pos < __sz)
-        ++__pos;
-    else
-        __pos = __sz;
-    for (const _CharT* __ps = __p + __pos; __ps != __p;)
-        if (!_Traits::eq(*--__ps, __c))
-            return static_cast<_SizeT>(__ps - __p);
-    return __npos;
-}
-
-template<class _Ptr>
-inline _LIBCPP_INLINE_VISIBILITY
-size_t __do_string_hash(_Ptr __p, _Ptr __e)
-{
-    typedef typename iterator_traits<_Ptr>::value_type value_type;
-    return __murmur2_or_cityhash<size_t>()(__p, (__e-__p)*sizeof(value_type));
-}
-
-template <class _CharT, class _Iter, class _Traits=char_traits<_CharT> >
-struct __quoted_output_proxy
-{
-    _Iter  __first;
-    _Iter  __last;
-    _CharT  __delim;
-    _CharT  __escape;
-
-    __quoted_output_proxy(_Iter __f, _Iter __l, _CharT __d, _CharT __e)
-    : __first(__f), __last(__l), __delim(__d), __escape(__e) {}
-    //  This would be a nice place for a string_ref 
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP___STRING
diff --git a/lib/libcxx/include/__threading_support b/lib/libcxx/include/__threading_support
deleted file mode 100644
index 20249006272..00000000000
--- a/lib/libcxx/include/__threading_support
+++ /dev/null
@@ -1,402 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_THREADING_SUPPORT
-#define _LIBCPP_THREADING_SUPPORT
-
-#include <__config>
-#include <chrono>
-#include <errno.h>
-
-#ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
-#pragma GCC system_header
-#endif
-
-#if defined(_LIBCPP_HAS_THREAD_API_EXTERNAL)
-# include <__external_threading>
-#elif !defined(_LIBCPP_HAS_NO_THREADS)
-
-#if defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
-# include <pthread.h>
-# include <sched.h>
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-#if defined(_LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL) || \
-    defined(_LIBCPP_BUILDING_THREAD_LIBRARY_EXTERNAL) || \
-    defined(_LIBCPP_HAS_THREAD_API_WIN32)
-#define _LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_FUNC_VIS
-#else
-#define _LIBCPP_THREAD_ABI_VISIBILITY inline _LIBCPP_INLINE_VISIBILITY
-#endif
-
-#if defined(__FreeBSD__) && defined(__clang__) && __has_attribute(no_thread_safety_analysis)
-#define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS __attribute__((no_thread_safety_analysis))
-#else
-#define _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
-// Mutex
-typedef pthread_mutex_t __libcpp_mutex_t;
-#define _LIBCPP_MUTEX_INITIALIZER PTHREAD_MUTEX_INITIALIZER
-
-typedef pthread_mutex_t __libcpp_recursive_mutex_t;
-
-// Condition Variable
-typedef pthread_cond_t __libcpp_condvar_t;
-#define _LIBCPP_CONDVAR_INITIALIZER PTHREAD_COND_INITIALIZER
-
-// Execute once
-typedef pthread_once_t __libcpp_exec_once_flag;
-#define _LIBCPP_EXEC_ONCE_INITIALIZER PTHREAD_ONCE_INIT
-
-// Thread id
-typedef pthread_t __libcpp_thread_id;
-
-// Thread
-#define _LIBCPP_NULL_THREAD 0U
-
-typedef pthread_t __libcpp_thread_t;
-
-// Thread Local Storage
-typedef pthread_key_t __libcpp_tls_key;
-
-#define _LIBCPP_TLS_DESTRUCTOR_CC
-#else
-// Mutex
-typedef void* __libcpp_mutex_t;
-#define _LIBCPP_MUTEX_INITIALIZER 0
-
-#if defined(_M_IX86) || defined(__i386__) || defined(_M_ARM) || defined(__arm__)
-typedef void* __libcpp_recursive_mutex_t[6];
-#elif defined(_M_AMD64) || defined(__x86_64__) || defined(_M_ARM64) || defined(__aarch64__)
-typedef void* __libcpp_recursive_mutex_t[5];
-#else
-# error Unsupported architecture
-#endif
-
-// Condition Variable
-typedef void* __libcpp_condvar_t;
-#define _LIBCPP_CONDVAR_INITIALIZER 0
-
-// Execute Once
-typedef void* __libcpp_exec_once_flag;
-#define _LIBCPP_EXEC_ONCE_INITIALIZER 0
-
-// Thread ID
-typedef long __libcpp_thread_id;
-
-// Thread
-#define _LIBCPP_NULL_THREAD 0U
-
-typedef void* __libcpp_thread_t;
-
-// Thread Local Storage
-typedef long __libcpp_tls_key;
-
-#define _LIBCPP_TLS_DESTRUCTOR_CC __stdcall
-#endif
-
-// Mutex
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_recursive_mutex_init(__libcpp_recursive_mutex_t *__m);
-
-_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
-int __libcpp_recursive_mutex_lock(__libcpp_recursive_mutex_t *__m);
-
-_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
-bool __libcpp_recursive_mutex_trylock(__libcpp_recursive_mutex_t *__m);
-
-_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
-int __libcpp_recursive_mutex_unlock(__libcpp_recursive_mutex_t *__m);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_recursive_mutex_destroy(__libcpp_recursive_mutex_t *__m);
-
-_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
-int __libcpp_mutex_lock(__libcpp_mutex_t *__m);
-
-_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
-bool __libcpp_mutex_trylock(__libcpp_mutex_t *__m);
-
-_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
-int __libcpp_mutex_unlock(__libcpp_mutex_t *__m);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_mutex_destroy(__libcpp_mutex_t *__m);
-
-// Condition variable
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_condvar_signal(__libcpp_condvar_t* __cv);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_condvar_broadcast(__libcpp_condvar_t* __cv);
-
-_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
-int __libcpp_condvar_wait(__libcpp_condvar_t* __cv, __libcpp_mutex_t* __m);
-
-_LIBCPP_THREAD_ABI_VISIBILITY _LIBCPP_NO_THREAD_SAFETY_ANALYSIS
-int __libcpp_condvar_timedwait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m,
-                               timespec *__ts);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_condvar_destroy(__libcpp_condvar_t* __cv);
-
-// Execute once
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_execute_once(__libcpp_exec_once_flag *flag,
-                          void (*init_routine)(void));
-
-// Thread id
-_LIBCPP_THREAD_ABI_VISIBILITY
-bool __libcpp_thread_id_equal(__libcpp_thread_id t1, __libcpp_thread_id t2);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-bool __libcpp_thread_id_less(__libcpp_thread_id t1, __libcpp_thread_id t2);
-
-// Thread
-_LIBCPP_THREAD_ABI_VISIBILITY
-bool __libcpp_thread_isnull(const __libcpp_thread_t *__t);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_thread_create(__libcpp_thread_t *__t, void *(*__func)(void *),
-                           void *__arg);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-__libcpp_thread_id __libcpp_thread_get_current_id();
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-__libcpp_thread_id __libcpp_thread_get_id(const __libcpp_thread_t *__t);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_thread_join(__libcpp_thread_t *__t);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_thread_detach(__libcpp_thread_t *__t);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-void __libcpp_thread_yield();
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-void __libcpp_thread_sleep_for(const chrono::nanoseconds& __ns);
-
-// Thread local storage
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_tls_create(__libcpp_tls_key* __key,
-                        void(_LIBCPP_TLS_DESTRUCTOR_CC* __at_exit)(void*));
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-void *__libcpp_tls_get(__libcpp_tls_key __key);
-
-_LIBCPP_THREAD_ABI_VISIBILITY
-int __libcpp_tls_set(__libcpp_tls_key __key, void *__p);
-
-#if (!defined(_LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL) || \
-     defined(_LIBCPP_BUILDING_THREAD_LIBRARY_EXTERNAL)) && \
-    defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
-
-int __libcpp_recursive_mutex_init(__libcpp_recursive_mutex_t *__m)
-{
-  pthread_mutexattr_t attr;
-  int __ec = pthread_mutexattr_init(&attr);
-  if (__ec)
-    return __ec;
-  __ec = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
-  if (__ec) {
-    pthread_mutexattr_destroy(&attr);
-    return __ec;
-  }
-  __ec = pthread_mutex_init(__m, &attr);
-  if (__ec) {
-    pthread_mutexattr_destroy(&attr);
-    return __ec;
-  }
-  __ec = pthread_mutexattr_destroy(&attr);
-  if (__ec) {
-    pthread_mutex_destroy(__m);
-    return __ec;
-  }
-  return 0;
-}
-
-int __libcpp_recursive_mutex_lock(__libcpp_recursive_mutex_t *__m)
-{
-  return pthread_mutex_lock(__m);
-}
-
-bool __libcpp_recursive_mutex_trylock(__libcpp_recursive_mutex_t *__m)
-{
-  return pthread_mutex_trylock(__m) == 0;
-}
-
-int __libcpp_recursive_mutex_unlock(__libcpp_mutex_t *__m)
-{
-  return pthread_mutex_unlock(__m);
-}
-
-int __libcpp_recursive_mutex_destroy(__libcpp_recursive_mutex_t *__m)
-{
-  return pthread_mutex_destroy(__m);
-}
-
-int __libcpp_mutex_lock(__libcpp_mutex_t *__m)
-{
-  return pthread_mutex_lock(__m);
-}
-
-bool __libcpp_mutex_trylock(__libcpp_mutex_t *__m)
-{
-  return pthread_mutex_trylock(__m) == 0;
-}
-
-int __libcpp_mutex_unlock(__libcpp_mutex_t *__m)
-{
-  return pthread_mutex_unlock(__m);
-}
-
-int __libcpp_mutex_destroy(__libcpp_mutex_t *__m)
-{
-  return pthread_mutex_destroy(__m);
-}
-
-// Condition Variable
-int __libcpp_condvar_signal(__libcpp_condvar_t *__cv)
-{
-  return pthread_cond_signal(__cv);
-}
-
-int __libcpp_condvar_broadcast(__libcpp_condvar_t *__cv)
-{
-  return pthread_cond_broadcast(__cv);
-}
-
-int __libcpp_condvar_wait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m)
-{
-  return pthread_cond_wait(__cv, __m);
-}
-
-int __libcpp_condvar_timedwait(__libcpp_condvar_t *__cv, __libcpp_mutex_t *__m,
-                               timespec *__ts)
-{
-  return pthread_cond_timedwait(__cv, __m, __ts);
-}
-
-int __libcpp_condvar_destroy(__libcpp_condvar_t *__cv)
-{
-  return pthread_cond_destroy(__cv);
-}
-
-// Execute once
-int __libcpp_execute_once(__libcpp_exec_once_flag *flag,
-                          void (*init_routine)(void)) {
-  return pthread_once(flag, init_routine);
-}
-
-// Thread id
-// Returns non-zero if the thread ids are equal, otherwise 0
-bool __libcpp_thread_id_equal(__libcpp_thread_id t1, __libcpp_thread_id t2)
-{
-  return pthread_equal(t1, t2) != 0;
-}
-
-// Returns non-zero if t1 < t2, otherwise 0
-bool __libcpp_thread_id_less(__libcpp_thread_id t1, __libcpp_thread_id t2)
-{
-  return t1 < t2;
-}
-
-// Thread
-bool __libcpp_thread_isnull(const __libcpp_thread_t *__t) {
-  return *__t == 0;
-}
-
-int __libcpp_thread_create(__libcpp_thread_t *__t, void *(*__func)(void *),
-                           void *__arg)
-{
-  return pthread_create(__t, 0, __func, __arg);
-}
-
-__libcpp_thread_id __libcpp_thread_get_current_id()
-{
-  return pthread_self();
-}
-
-__libcpp_thread_id __libcpp_thread_get_id(const __libcpp_thread_t *__t)
-{
-  return *__t;
-}
-
-int __libcpp_thread_join(__libcpp_thread_t *__t)
-{
-  return pthread_join(*__t, 0);
-}
-
-int __libcpp_thread_detach(__libcpp_thread_t *__t)
-{
-  return pthread_detach(*__t);
-}
-
-void __libcpp_thread_yield()
-{
-  sched_yield();
-}
-
-void __libcpp_thread_sleep_for(const chrono::nanoseconds& __ns)
-{
-   using namespace chrono;
-   seconds __s = duration_cast<seconds>(__ns);
-   timespec __ts;
-   typedef decltype(__ts.tv_sec) ts_sec;
-   _LIBCPP_CONSTEXPR ts_sec __ts_sec_max = numeric_limits<ts_sec>::max();
-
-   if (__s.count() < __ts_sec_max)
-   {
-     __ts.tv_sec = static_cast<ts_sec>(__s.count());
-     __ts.tv_nsec = static_cast<decltype(__ts.tv_nsec)>((__ns - __s).count());
-   }
-   else
-   {
-     __ts.tv_sec = __ts_sec_max;
-     __ts.tv_nsec = 999999999; // (10^9 - 1)
-   }
-
-   while (nanosleep(&__ts, &__ts) == -1 && errno == EINTR);
-}
-
-// Thread local storage
-int __libcpp_tls_create(__libcpp_tls_key *__key, void (*__at_exit)(void *))
-{
-  return pthread_key_create(__key, __at_exit);
-}
-
-void *__libcpp_tls_get(__libcpp_tls_key __key)
-{
-  return pthread_getspecific(__key);
-}
-
-int __libcpp_tls_set(__libcpp_tls_key __key, void *__p)
-{
-    return pthread_setspecific(__key, __p);
-}
-
-#endif // !_LIBCPP_HAS_THREAD_LIBRARY_EXTERNAL || _LIBCPP_BUILDING_THREAD_LIBRARY_EXTERNAL
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif // !_LIBCPP_HAS_NO_THREADS
-
-#endif // _LIBCPP_THREADING_SUPPORT
diff --git a/lib/libcxx/include/__tree b/lib/libcxx/include/__tree
deleted file mode 100644
index 814851085b9..00000000000
--- a/lib/libcxx/include/__tree
+++ /dev/null
@@ -1,2879 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___TREE
-#define _LIBCPP___TREE
-
-#include <__config>
-#include <iterator>
-#include <memory>
-#include <stdexcept>
-#include <algorithm>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp, class _Compare, class _Allocator> class __tree;
-template <class _Tp, class _NodePtr, class _DiffType>
-    class _LIBCPP_TEMPLATE_VIS __tree_iterator;
-template <class _Tp, class _ConstNodePtr, class _DiffType>
-    class _LIBCPP_TEMPLATE_VIS __tree_const_iterator;
-
-template <class _Pointer> class __tree_end_node;
-template <class _VoidPtr> class __tree_node_base;
-template <class _Tp, class _VoidPtr> class __tree_node;
-
-template <class _Key, class _Value>
-struct __value_type;
-
-template <class _Allocator> class __map_node_destructor;
-template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_iterator;
-template <class _TreeIterator> class _LIBCPP_TEMPLATE_VIS __map_const_iterator;
-
-/*
-
-_NodePtr algorithms
-
-The algorithms taking _NodePtr are red black tree algorithms.  Those
-algorithms taking a parameter named __root should assume that __root
-points to a proper red black tree (unless otherwise specified).
-
-Each algorithm herein assumes that __root->__parent_ points to a non-null
-structure which has a member __left_ which points back to __root.  No other
-member is read or written to at __root->__parent_.
-
-__root->__parent_ will be referred to below (in comments only) as end_node.
-end_node->__left_ is an externably accessible lvalue for __root, and can be
-changed by node insertion and removal (without explicit reference to end_node).
-
-All nodes (with the exception of end_node), even the node referred to as
-__root, have a non-null __parent_ field.
-
-*/
-
-// Returns:  true if __x is a left child of its parent, else false
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-__tree_is_left_child(_NodePtr __x) _NOEXCEPT
-{
-    return __x == __x->__parent_->__left_;
-}
-
-// Determines if the subtree rooted at __x is a proper red black subtree.  If
-//    __x is a proper subtree, returns the black height (null counts as 1).  If
-//    __x is an improper subtree, returns 0.
-template <class _NodePtr>
-unsigned
-__tree_sub_invariant(_NodePtr __x)
-{
-    if (__x == nullptr)
-        return 1;
-    // parent consistency checked by caller
-    // check __x->__left_ consistency
-    if (__x->__left_ != nullptr && __x->__left_->__parent_ != __x)
-        return 0;
-    // check __x->__right_ consistency
-    if (__x->__right_ != nullptr && __x->__right_->__parent_ != __x)
-        return 0;
-    // check __x->__left_ != __x->__right_ unless both are nullptr
-    if (__x->__left_ == __x->__right_ && __x->__left_ != nullptr)
-        return 0;
-    // If this is red, neither child can be red
-    if (!__x->__is_black_)
-    {
-        if (__x->__left_ && !__x->__left_->__is_black_)
-            return 0;
-        if (__x->__right_ && !__x->__right_->__is_black_)
-            return 0;
-    }
-    unsigned __h = __tree_sub_invariant(__x->__left_);
-    if (__h == 0)
-        return 0;  // invalid left subtree
-    if (__h != __tree_sub_invariant(__x->__right_))
-        return 0;  // invalid or different height right subtree
-    return __h + __x->__is_black_;  // return black height of this node
-}
-
-// Determines if the red black tree rooted at __root is a proper red black tree.
-//    __root == nullptr is a proper tree.  Returns true is __root is a proper
-//    red black tree, else returns false.
-template <class _NodePtr>
-bool
-__tree_invariant(_NodePtr __root)
-{
-    if (__root == nullptr)
-        return true;
-    // check __x->__parent_ consistency
-    if (__root->__parent_ == nullptr)
-        return false;
-    if (!__tree_is_left_child(__root))
-        return false;
-    // root must be black
-    if (!__root->__is_black_)
-        return false;
-    // do normal node checks
-    return __tree_sub_invariant(__root) != 0;
-}
-
-// Returns:  pointer to the left-most node under __x.
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-_NodePtr
-__tree_min(_NodePtr __x) _NOEXCEPT
-{
-    while (__x->__left_ != nullptr)
-        __x = __x->__left_;
-    return __x;
-}
-
-// Returns:  pointer to the right-most node under __x.
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-_NodePtr
-__tree_max(_NodePtr __x) _NOEXCEPT
-{
-    while (__x->__right_ != nullptr)
-        __x = __x->__right_;
-    return __x;
-}
-
-// Returns:  pointer to the next in-order node after __x.
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-_NodePtr
-__tree_next(_NodePtr __x) _NOEXCEPT
-{
-    if (__x->__right_ != nullptr)
-        return __tree_min(__x->__right_);
-    while (!__tree_is_left_child(__x))
-        __x = __x->__parent_unsafe();
-    return __x->__parent_unsafe();
-}
-
-template <class _EndNodePtr, class _NodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-_EndNodePtr
-__tree_next_iter(_NodePtr __x) _NOEXCEPT
-{
-    if (__x->__right_ != nullptr)
-        return static_cast<_EndNodePtr>(__tree_min(__x->__right_));
-    while (!__tree_is_left_child(__x))
-        __x = __x->__parent_unsafe();
-    return static_cast<_EndNodePtr>(__x->__parent_);
-}
-
-// Returns:  pointer to the previous in-order node before __x.
-// Precondition:  __x != nullptr.
-// Note: __x may be the end node.
-template <class _NodePtr, class _EndNodePtr>
-inline _LIBCPP_INLINE_VISIBILITY
-_NodePtr
-__tree_prev_iter(_EndNodePtr __x) _NOEXCEPT
-{
-    if (__x->__left_ != nullptr)
-        return __tree_max(__x->__left_);
-    _NodePtr __xx = static_cast<_NodePtr>(__x);
-    while (__tree_is_left_child(__xx))
-        __xx = __xx->__parent_unsafe();
-    return __xx->__parent_unsafe();
-}
-
-// Returns:  pointer to a node which has no children
-// Precondition:  __x != nullptr.
-template <class _NodePtr>
-_NodePtr
-__tree_leaf(_NodePtr __x) _NOEXCEPT
-{
-    while (true)
-    {
-        if (__x->__left_ != nullptr)
-        {
-            __x = __x->__left_;
-            continue;
-        }
-        if (__x->__right_ != nullptr)
-        {
-            __x = __x->__right_;
-            continue;
-        }
-        break;
-    }
-    return __x;
-}
-
-// Effects:  Makes __x->__right_ the subtree root with __x as its left child
-//           while preserving in-order order.
-// Precondition:  __x->__right_ != nullptr
-template <class _NodePtr>
-void
-__tree_left_rotate(_NodePtr __x) _NOEXCEPT
-{
-    _NodePtr __y = __x->__right_;
-    __x->__right_ = __y->__left_;
-    if (__x->__right_ != nullptr)
-        __x->__right_->__set_parent(__x);
-    __y->__parent_ = __x->__parent_;
-    if (__tree_is_left_child(__x))
-        __x->__parent_->__left_ = __y;
-    else
-        __x->__parent_unsafe()->__right_ = __y;
-    __y->__left_ = __x;
-    __x->__set_parent(__y);
-}
-
-// Effects:  Makes __x->__left_ the subtree root with __x as its right child
-//           while preserving in-order order.
-// Precondition:  __x->__left_ != nullptr
-template <class _NodePtr>
-void
-__tree_right_rotate(_NodePtr __x) _NOEXCEPT
-{
-    _NodePtr __y = __x->__left_;
-    __x->__left_ = __y->__right_;
-    if (__x->__left_ != nullptr)
-        __x->__left_->__set_parent(__x);
-    __y->__parent_ = __x->__parent_;
-    if (__tree_is_left_child(__x))
-        __x->__parent_->__left_ = __y;
-    else
-        __x->__parent_unsafe()->__right_ = __y;
-    __y->__right_ = __x;
-    __x->__set_parent(__y);
-}
-
-// Effects:  Rebalances __root after attaching __x to a leaf.
-// Precondition:  __root != nulptr && __x != nullptr.
-//                __x has no children.
-//                __x == __root or == a direct or indirect child of __root.
-//                If __x were to be unlinked from __root (setting __root to
-//                  nullptr if __root == __x), __tree_invariant(__root) == true.
-// Postcondition: __tree_invariant(end_node->__left_) == true.  end_node->__left_
-//                may be different than the value passed in as __root.
-template <class _NodePtr>
-void
-__tree_balance_after_insert(_NodePtr __root, _NodePtr __x) _NOEXCEPT
-{
-    __x->__is_black_ = __x == __root;
-    while (__x != __root && !__x->__parent_unsafe()->__is_black_)
-    {
-        // __x->__parent_ != __root because __x->__parent_->__is_black == false
-        if (__tree_is_left_child(__x->__parent_unsafe()))
-        {
-            _NodePtr __y = __x->__parent_unsafe()->__parent_unsafe()->__right_;
-            if (__y != nullptr && !__y->__is_black_)
-            {
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = true;
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = __x == __root;
-                __y->__is_black_ = true;
-            }
-            else
-            {
-                if (!__tree_is_left_child(__x))
-                {
-                    __x = __x->__parent_unsafe();
-                    __tree_left_rotate(__x);
-                }
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = true;
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = false;
-                __tree_right_rotate(__x);
-                break;
-            }
-        }
-        else
-        {
-            _NodePtr __y = __x->__parent_unsafe()->__parent_->__left_;
-            if (__y != nullptr && !__y->__is_black_)
-            {
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = true;
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = __x == __root;
-                __y->__is_black_ = true;
-            }
-            else
-            {
-                if (__tree_is_left_child(__x))
-                {
-                    __x = __x->__parent_unsafe();
-                    __tree_right_rotate(__x);
-                }
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = true;
-                __x = __x->__parent_unsafe();
-                __x->__is_black_ = false;
-                __tree_left_rotate(__x);
-                break;
-            }
-        }
-    }
-}
-
-// Precondition:  __root != nullptr && __z != nullptr.
-//                __tree_invariant(__root) == true.
-//                __z == __root or == a direct or indirect child of __root.
-// Effects:  unlinks __z from the tree rooted at __root, rebalancing as needed.
-// Postcondition: __tree_invariant(end_node->__left_) == true && end_node->__left_
-//                nor any of its children refer to __z.  end_node->__left_
-//                may be different than the value passed in as __root.
-template <class _NodePtr>
-void
-__tree_remove(_NodePtr __root, _NodePtr __z) _NOEXCEPT
-{
-    // __z will be removed from the tree.  Client still needs to destruct/deallocate it
-    // __y is either __z, or if __z has two children, __tree_next(__z).
-    // __y will have at most one child.
-    // __y will be the initial hole in the tree (make the hole at a leaf)
-    _NodePtr __y = (__z->__left_ == nullptr || __z->__right_ == nullptr) ?
-                    __z : __tree_next(__z);
-    // __x is __y's possibly null single child
-    _NodePtr __x = __y->__left_ != nullptr ? __y->__left_ : __y->__right_;
-    // __w is __x's possibly null uncle (will become __x's sibling)
-    _NodePtr __w = nullptr;
-    // link __x to __y's parent, and find __w
-    if (__x != nullptr)
-        __x->__parent_ = __y->__parent_;
-    if (__tree_is_left_child(__y))
-    {
-        __y->__parent_->__left_ = __x;
-        if (__y != __root)
-            __w = __y->__parent_unsafe()->__right_;
-        else
-            __root = __x;  // __w == nullptr
-    }
-    else
-    {
-        __y->__parent_unsafe()->__right_ = __x;
-        // __y can't be root if it is a right child
-        __w = __y->__parent_->__left_;
-    }
-    bool __removed_black = __y->__is_black_;
-    // If we didn't remove __z, do so now by splicing in __y for __z,
-    //    but copy __z's color.  This does not impact __x or __w.
-    if (__y != __z)
-    {
-        // __z->__left_ != nulptr but __z->__right_ might == __x == nullptr
-        __y->__parent_ = __z->__parent_;
-        if (__tree_is_left_child(__z))
-            __y->__parent_->__left_ = __y;
-        else
-            __y->__parent_unsafe()->__right_ = __y;
-        __y->__left_ = __z->__left_;
-        __y->__left_->__set_parent(__y);
-        __y->__right_ = __z->__right_;
-        if (__y->__right_ != nullptr)
-            __y->__right_->__set_parent(__y);
-        __y->__is_black_ = __z->__is_black_;
-        if (__root == __z)
-            __root = __y;
-    }
-    // There is no need to rebalance if we removed a red, or if we removed
-    //     the last node.
-    if (__removed_black && __root != nullptr)
-    {
-        // Rebalance:
-        // __x has an implicit black color (transferred from the removed __y)
-        //    associated with it, no matter what its color is.
-        // If __x is __root (in which case it can't be null), it is supposed
-        //    to be black anyway, and if it is doubly black, then the double
-        //    can just be ignored.
-        // If __x is red (in which case it can't be null), then it can absorb
-        //    the implicit black just by setting its color to black.
-        // Since __y was black and only had one child (which __x points to), __x
-        //   is either red with no children, else null, otherwise __y would have
-        //   different black heights under left and right pointers.
-        // if (__x == __root || __x != nullptr && !__x->__is_black_)
-        if (__x != nullptr)
-            __x->__is_black_ = true;
-        else
-        {
-            //  Else __x isn't root, and is "doubly black", even though it may
-            //     be null.  __w can not be null here, else the parent would
-            //     see a black height >= 2 on the __x side and a black height
-            //     of 1 on the __w side (__w must be a non-null black or a red
-            //     with a non-null black child).
-            while (true)
-            {
-                if (!__tree_is_left_child(__w))  // if x is left child
-                {
-                    if (!__w->__is_black_)
-                    {
-                        __w->__is_black_ = true;
-                        __w->__parent_unsafe()->__is_black_ = false;
-                        __tree_left_rotate(__w->__parent_unsafe());
-                        // __x is still valid
-                        // reset __root only if necessary
-                        if (__root == __w->__left_)
-                            __root = __w;
-                        // reset sibling, and it still can't be null
-                        __w = __w->__left_->__right_;
-                    }
-                    // __w->__is_black_ is now true, __w may have null children
-                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) &&
-                        (__w->__right_ == nullptr || __w->__right_->__is_black_))
-                    {
-                        __w->__is_black_ = false;
-                        __x = __w->__parent_unsafe();
-                        // __x can no longer be null
-                        if (__x == __root || !__x->__is_black_)
-                        {
-                            __x->__is_black_ = true;
-                            break;
-                        }
-                        // reset sibling, and it still can't be null
-                        __w = __tree_is_left_child(__x) ?
-                                    __x->__parent_unsafe()->__right_ :
-                                    __x->__parent_->__left_;
-                        // continue;
-                    }
-                    else  // __w has a red child
-                    {
-                        if (__w->__right_ == nullptr || __w->__right_->__is_black_)
-                        {
-                            // __w left child is non-null and red
-                            __w->__left_->__is_black_ = true;
-                            __w->__is_black_ = false;
-                            __tree_right_rotate(__w);
-                            // __w is known not to be root, so root hasn't changed
-                            // reset sibling, and it still can't be null
-                            __w = __w->__parent_unsafe();
-                        }
-                        // __w has a right red child, left child may be null
-                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_;
-                        __w->__parent_unsafe()->__is_black_ = true;
-                        __w->__right_->__is_black_ = true;
-                        __tree_left_rotate(__w->__parent_unsafe());
-                        break;
-                    }
-                }
-                else
-                {
-                    if (!__w->__is_black_)
-                    {
-                        __w->__is_black_ = true;
-                        __w->__parent_unsafe()->__is_black_ = false;
-                        __tree_right_rotate(__w->__parent_unsafe());
-                        // __x is still valid
-                        // reset __root only if necessary
-                        if (__root == __w->__right_)
-                            __root = __w;
-                        // reset sibling, and it still can't be null
-                        __w = __w->__right_->__left_;
-                    }
-                    // __w->__is_black_ is now true, __w may have null children
-                    if ((__w->__left_  == nullptr || __w->__left_->__is_black_) &&
-                        (__w->__right_ == nullptr || __w->__right_->__is_black_))
-                    {
-                        __w->__is_black_ = false;
-                        __x = __w->__parent_unsafe();
-                        // __x can no longer be null
-                        if (!__x->__is_black_ || __x == __root)
-                        {
-                            __x->__is_black_ = true;
-                            break;
-                        }
-                        // reset sibling, and it still can't be null
-                        __w = __tree_is_left_child(__x) ?
-                                    __x->__parent_unsafe()->__right_ :
-                                    __x->__parent_->__left_;
-                        // continue;
-                    }
-                    else  // __w has a red child
-                    {
-                        if (__w->__left_ == nullptr || __w->__left_->__is_black_)
-                        {
-                            // __w right child is non-null and red
-                            __w->__right_->__is_black_ = true;
-                            __w->__is_black_ = false;
-                            __tree_left_rotate(__w);
-                            // __w is known not to be root, so root hasn't changed
-                            // reset sibling, and it still can't be null
-                            __w = __w->__parent_unsafe();
-                        }
-                        // __w has a left red child, right child may be null
-                        __w->__is_black_ = __w->__parent_unsafe()->__is_black_;
-                        __w->__parent_unsafe()->__is_black_ = true;
-                        __w->__left_->__is_black_ = true;
-                        __tree_right_rotate(__w->__parent_unsafe());
-                        break;
-                    }
-                }
-            }
-        }
-    }
-}
-
-// node traits
-
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp>
-struct __is_tree_value_type_imp : false_type {};
-
-template <class _Key, class _Value>
-struct __is_tree_value_type_imp<__value_type<_Key, _Value>> : true_type {};
-
-template <class ..._Args>
-struct __is_tree_value_type : false_type {};
-
-template <class _One>
-struct __is_tree_value_type<_One> : __is_tree_value_type_imp<typename __uncvref<_One>::type> {};
-#endif
-
-template <class _Tp>
-struct __tree_key_value_types {
-  typedef _Tp key_type;
-  typedef _Tp __node_value_type;
-  typedef _Tp __container_value_type;
-  static const bool __is_map = false;
-
-  _LIBCPP_INLINE_VISIBILITY
-  static key_type const& __get_key(_Tp const& __v) {
-    return __v;
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type const& __get_value(__node_value_type const& __v) {
-    return __v;
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type* __get_ptr(__node_value_type& __n) {
-    return _VSTD::addressof(__n);
-  }
-#ifndef _LIBCPP_CXX03_LANG
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type&& __move(__node_value_type& __v) {
-    return _VSTD::move(__v);
-  }
-#endif
-};
-
-template <class _Key, class _Tp>
-struct __tree_key_value_types<__value_type<_Key, _Tp> > {
-  typedef _Key                                         key_type;
-  typedef _Tp                                          mapped_type;
-  typedef __value_type<_Key, _Tp>                      __node_value_type;
-  typedef pair<const _Key, _Tp>                        __container_value_type;
-  typedef __container_value_type                       __map_value_type;
-  static const bool __is_map = true;
-
-  _LIBCPP_INLINE_VISIBILITY
-  static key_type const&
-  __get_key(__node_value_type const& __t) {
-    return __t.__get_value().first;
-  }
-
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value,
-      key_type const&>::type
-  __get_key(_Up& __t) {
-    return __t.first;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type const&
-  __get_value(__node_value_type const& __t) {
-    return __t.__get_value();
-  }
-
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value,
-      __container_value_type const&>::type
-  __get_value(_Up& __t) {
-    return __t;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  static __container_value_type* __get_ptr(__node_value_type& __n) {
-    return _VSTD::addressof(__n.__get_value());
-  }
-
-#ifndef _LIBCPP_CXX03_LANG
-  _LIBCPP_INLINE_VISIBILITY
-  static pair<key_type&&, mapped_type&&> __move(__node_value_type& __v) {
-    return __v.__move();
-  }
-#endif
-};
-
-template <class _VoidPtr>
-struct __tree_node_base_types {
-  typedef _VoidPtr                                               __void_pointer;
-
-  typedef __tree_node_base<__void_pointer>                      __node_base_type;
-  typedef typename __rebind_pointer<_VoidPtr, __node_base_type>::type
-                                                             __node_base_pointer;
-
-  typedef __tree_end_node<__node_base_pointer>                  __end_node_type;
-  typedef typename __rebind_pointer<_VoidPtr, __end_node_type>::type
-                                                             __end_node_pointer;
-#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB)
-  typedef __end_node_pointer __parent_pointer;
-#else
-  typedef typename conditional<
-      is_pointer<__end_node_pointer>::value,
-        __end_node_pointer,
-        __node_base_pointer>::type __parent_pointer;
-#endif
-
-private:
-  static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value),
-                  "_VoidPtr does not point to unqualified void type");
-};
-
-template <class _Tp, class _AllocPtr, class _KVTypes = __tree_key_value_types<_Tp>,
-         bool = _KVTypes::__is_map>
-struct __tree_map_pointer_types {};
-
-template <class _Tp, class _AllocPtr, class _KVTypes>
-struct __tree_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> {
-  typedef typename _KVTypes::__map_value_type   _Mv;
-  typedef typename __rebind_pointer<_AllocPtr, _Mv>::type
-                                                       __map_value_type_pointer;
-  typedef typename __rebind_pointer<_AllocPtr, const _Mv>::type
-                                                 __const_map_value_type_pointer;
-};
-
-template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type>
-struct __tree_node_types;
-
-template <class _NodePtr, class _Tp, class _VoidPtr>
-struct __tree_node_types<_NodePtr, __tree_node<_Tp, _VoidPtr> >
-    : public __tree_node_base_types<_VoidPtr>,
-             __tree_key_value_types<_Tp>,
-             __tree_map_pointer_types<_Tp, _VoidPtr>
-{
-  typedef __tree_node_base_types<_VoidPtr> __base;
-  typedef __tree_key_value_types<_Tp>      __key_base;
-  typedef __tree_map_pointer_types<_Tp, _VoidPtr> __map_pointer_base;
-public:
-
-  typedef typename pointer_traits<_NodePtr>::element_type       __node_type;
-  typedef _NodePtr                                              __node_pointer;
-
-  typedef _Tp                                                 __node_value_type;
-  typedef typename __rebind_pointer<_VoidPtr, __node_value_type>::type
-                                                      __node_value_type_pointer;
-  typedef typename __rebind_pointer<_VoidPtr, const __node_value_type>::type
-                                                __const_node_value_type_pointer;
-#if defined(_LIBCPP_ABI_TREE_REMOVE_NODE_POINTER_UB)
-  typedef typename __base::__end_node_pointer __iter_pointer;
-#else
-  typedef typename conditional<
-      is_pointer<__node_pointer>::value,
-        typename __base::__end_node_pointer,
-        __node_pointer>::type __iter_pointer;
-#endif
-private:
-    static_assert(!is_const<__node_type>::value,
-                "_NodePtr should never be a pointer to const");
-    static_assert((is_same<typename __rebind_pointer<_VoidPtr, __node_type>::type,
-                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr.");
-};
-
-template <class _ValueTp, class _VoidPtr>
-struct __make_tree_node_types {
-  typedef typename __rebind_pointer<_VoidPtr, __tree_node<_ValueTp, _VoidPtr> >::type
-                                                                        _NodePtr;
-  typedef __tree_node_types<_NodePtr> type;
-};
-
-// node
-
-template <class _Pointer>
-class __tree_end_node
-{
-public:
-    typedef _Pointer pointer;
-    pointer __left_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_end_node() _NOEXCEPT : __left_() {}
-};
-
-template <class _VoidPtr>
-class __tree_node_base
-    : public __tree_node_base_types<_VoidPtr>::__end_node_type
-{
-    typedef __tree_node_base_types<_VoidPtr> _NodeBaseTypes;
-
-public:
-    typedef typename _NodeBaseTypes::__node_base_pointer pointer;
-    typedef typename _NodeBaseTypes::__parent_pointer __parent_pointer;
-
-    pointer          __right_;
-    __parent_pointer __parent_;
-    bool __is_black_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    pointer __parent_unsafe() const { return static_cast<pointer>(__parent_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __set_parent(pointer __p) {
-        __parent_ = static_cast<__parent_pointer>(__p);
-    }
-
-private:
-  ~__tree_node_base() _LIBCPP_EQUAL_DELETE;
-  __tree_node_base(__tree_node_base const&) _LIBCPP_EQUAL_DELETE;
-  __tree_node_base& operator=(__tree_node_base const&) _LIBCPP_EQUAL_DELETE;
-};
-
-template <class _Tp, class _VoidPtr>
-class __tree_node
-    : public __tree_node_base<_VoidPtr>
-{
-public:
-    typedef _Tp __node_value_type;
-
-    __node_value_type __value_;
-
-private:
-  ~__tree_node() _LIBCPP_EQUAL_DELETE;
-  __tree_node(__tree_node const&) _LIBCPP_EQUAL_DELETE;
-  __tree_node& operator=(__tree_node const&) _LIBCPP_EQUAL_DELETE;
-};
-
-
-template <class _Allocator>
-class __tree_node_destructor
-{
-    typedef _Allocator                                      allocator_type;
-    typedef allocator_traits<allocator_type>                __alloc_traits;
-
-public:
-    typedef typename __alloc_traits::pointer                pointer;
-private:
-    typedef __tree_node_types<pointer> _NodeTypes;
-    allocator_type& __na_;
-
-    __tree_node_destructor& operator=(const __tree_node_destructor&);
-
-public:
-    bool __value_constructed;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_node_destructor(allocator_type& __na, bool __val = false) _NOEXCEPT
-        : __na_(__na),
-          __value_constructed(__val)
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()(pointer __p) _NOEXCEPT
-    {
-        if (__value_constructed)
-            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_));
-        if (__p)
-            __alloc_traits::deallocate(__na_, __p, 1);
-    }
-
-    template <class> friend class __map_node_destructor;
-};
-
-#if _LIBCPP_STD_VER > 14
-template <class _NodeType, class _Alloc>
-struct __generic_container_node_destructor;
-template <class _Tp, class _VoidPtr, class _Alloc>
-struct __generic_container_node_destructor<__tree_node<_Tp, _VoidPtr>, _Alloc>
-    : __tree_node_destructor<_Alloc>
-{
-    using __tree_node_destructor<_Alloc>::__tree_node_destructor;
-};
-#endif
-
-template <class _Tp, class _NodePtr, class _DiffType>
-class _LIBCPP_TEMPLATE_VIS __tree_iterator
-{
-    typedef __tree_node_types<_NodePtr>                     _NodeTypes;
-    typedef _NodePtr                                        __node_pointer;
-    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer;
-    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer;
-    typedef typename _NodeTypes::__iter_pointer             __iter_pointer;
-    typedef pointer_traits<__node_pointer> __pointer_traits;
-
-    __iter_pointer __ptr_;
-
-public:
-    typedef bidirectional_iterator_tag                     iterator_category;
-    typedef _Tp                                            value_type;
-    typedef _DiffType                                      difference_type;
-    typedef value_type&                                    reference;
-    typedef typename _NodeTypes::__node_value_type_pointer pointer;
-
-    _LIBCPP_INLINE_VISIBILITY __tree_iterator() _NOEXCEPT
-#if _LIBCPP_STD_VER > 11
-    : __ptr_(nullptr)
-#endif
-    {}
-
-    _LIBCPP_INLINE_VISIBILITY reference operator*() const
-        {return __get_np()->__value_;}
-    _LIBCPP_INLINE_VISIBILITY pointer operator->() const
-        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_iterator& operator++() {
-      __ptr_ = static_cast<__iter_pointer>(
-          __tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_)));
-      return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_iterator operator++(int)
-        {__tree_iterator __t(*this); ++(*this); return __t;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_iterator& operator--() {
-      __ptr_ = static_cast<__iter_pointer>(__tree_prev_iter<__node_base_pointer>(
-          static_cast<__end_node_pointer>(__ptr_)));
-      return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_iterator operator--(int)
-        {__tree_iterator __t(*this); --(*this); return __t;}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const __tree_iterator& __x, const __tree_iterator& __y)
-        {return __x.__ptr_ == __y.__ptr_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const __tree_iterator& __x, const __tree_iterator& __y)
-        {return !(__x == __y);}
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_iterator(__node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_iterator(__end_node_pointer __p) _NOEXCEPT : __ptr_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); }
-    template <class, class, class> friend class __tree;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS __tree_const_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_iterator;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset;
-};
-
-template <class _Tp, class _NodePtr, class _DiffType>
-class _LIBCPP_TEMPLATE_VIS __tree_const_iterator
-{
-    typedef __tree_node_types<_NodePtr>                     _NodeTypes;
-    typedef typename _NodeTypes::__node_pointer             __node_pointer;
-    typedef typename _NodeTypes::__node_base_pointer        __node_base_pointer;
-    typedef typename _NodeTypes::__end_node_pointer         __end_node_pointer;
-    typedef typename _NodeTypes::__iter_pointer             __iter_pointer;
-    typedef pointer_traits<__node_pointer> __pointer_traits;
-
-    __iter_pointer __ptr_;
-
-public:
-    typedef bidirectional_iterator_tag                           iterator_category;
-    typedef _Tp                                                  value_type;
-    typedef _DiffType                                            difference_type;
-    typedef const value_type&                                    reference;
-    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
-
-    _LIBCPP_INLINE_VISIBILITY __tree_const_iterator() _NOEXCEPT
-#if _LIBCPP_STD_VER > 11
-    : __ptr_(nullptr)
-#endif
-    {}
-
-private:
-    typedef __tree_iterator<value_type, __node_pointer, difference_type>
-                                                           __non_const_iterator;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator(__non_const_iterator __p) _NOEXCEPT
-        : __ptr_(__p.__ptr_) {}
-
-    _LIBCPP_INLINE_VISIBILITY reference operator*() const
-        {return __get_np()->__value_;}
-    _LIBCPP_INLINE_VISIBILITY pointer operator->() const
-        {return pointer_traits<pointer>::pointer_to(__get_np()->__value_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator& operator++() {
-      __ptr_ = static_cast<__iter_pointer>(
-          __tree_next_iter<__end_node_pointer>(static_cast<__node_base_pointer>(__ptr_)));
-      return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator operator++(int)
-        {__tree_const_iterator __t(*this); ++(*this); return __t;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator& operator--() {
-      __ptr_ = static_cast<__iter_pointer>(__tree_prev_iter<__node_base_pointer>(
-          static_cast<__end_node_pointer>(__ptr_)));
-      return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tree_const_iterator operator--(int)
-        {__tree_const_iterator __t(*this); --(*this); return __t;}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const __tree_const_iterator& __x, const __tree_const_iterator& __y)
-        {return __x.__ptr_ == __y.__ptr_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const __tree_const_iterator& __x, const __tree_const_iterator& __y)
-        {return !(__x == __y);}
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_const_iterator(__node_pointer __p) _NOEXCEPT
-        : __ptr_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __tree_const_iterator(__end_node_pointer __p) _NOEXCEPT
-        : __ptr_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __get_np() const { return static_cast<__node_pointer>(__ptr_); }
-
-    template <class, class, class> friend class __tree;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS set;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS multiset;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_const_iterator;
-
-};
-
-template<class _Tp, class _Compare>
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_DIAGNOSE_WARNING(!std::__invokable<_Compare const&, _Tp const&, _Tp const&>::value,
-        "the specified comparator type does not provide a const call operator")
-#endif
-int __diagnose_non_const_comparator();
-
-template <class _Tp, class _Compare, class _Allocator>
-class __tree
-{
-public:
-    typedef _Tp                                      value_type;
-    typedef _Compare                                 value_compare;
-    typedef _Allocator                               allocator_type;
-
-private:
-    typedef allocator_traits<allocator_type>         __alloc_traits;
-    typedef typename __make_tree_node_types<value_type,
-        typename __alloc_traits::void_pointer>::type
-                                                    _NodeTypes;
-    typedef typename _NodeTypes::key_type           key_type;
-public:
-    typedef typename _NodeTypes::__node_value_type      __node_value_type;
-    typedef typename _NodeTypes::__container_value_type __container_value_type;
-
-    typedef typename __alloc_traits::pointer         pointer;
-    typedef typename __alloc_traits::const_pointer   const_pointer;
-    typedef typename __alloc_traits::size_type       size_type;
-    typedef typename __alloc_traits::difference_type difference_type;
-
-public:
-    typedef typename _NodeTypes::__void_pointer        __void_pointer;
-
-    typedef typename _NodeTypes::__node_type           __node;
-    typedef typename _NodeTypes::__node_pointer        __node_pointer;
-
-    typedef typename _NodeTypes::__node_base_type      __node_base;
-    typedef typename _NodeTypes::__node_base_pointer   __node_base_pointer;
-
-    typedef typename _NodeTypes::__end_node_type       __end_node_t;
-    typedef typename _NodeTypes::__end_node_pointer    __end_node_ptr;
-
-    typedef typename _NodeTypes::__parent_pointer      __parent_pointer;
-    typedef typename _NodeTypes::__iter_pointer        __iter_pointer;
-
-    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
-    typedef allocator_traits<__node_allocator>         __node_traits;
-
-private:
-    // check for sane allocator pointer rebinding semantics. Rebinding the
-    // allocator for a new pointer type should be exactly the same as rebinding
-    // the pointer using 'pointer_traits'.
-    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value),
-                  "Allocator does not rebind pointers in a sane manner.");
-    typedef typename __rebind_alloc_helper<__node_traits, __node_base>::type
-        __node_base_allocator;
-    typedef allocator_traits<__node_base_allocator> __node_base_traits;
-    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value),
-                 "Allocator does not rebind pointers in a sane manner.");
-
-private:
-    __iter_pointer                                     __begin_node_;
-    __compressed_pair<__end_node_t, __node_allocator>  __pair1_;
-    __compressed_pair<size_type, value_compare>        __pair3_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __iter_pointer __end_node() _NOEXCEPT
-    {
-        return static_cast<__iter_pointer>(
-                pointer_traits<__end_node_ptr>::pointer_to(__pair1_.first())
-        );
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __iter_pointer __end_node() const _NOEXCEPT
-    {
-        return static_cast<__iter_pointer>(
-            pointer_traits<__end_node_ptr>::pointer_to(
-                const_cast<__end_node_t&>(__pair1_.first())
-            )
-        );
-    }
-    _LIBCPP_INLINE_VISIBILITY
-          __node_allocator& __node_alloc() _NOEXCEPT {return __pair1_.second();}
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    const __node_allocator& __node_alloc() const _NOEXCEPT
-        {return __pair1_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-          __iter_pointer& __begin_node() _NOEXCEPT {return __begin_node_;}
-    _LIBCPP_INLINE_VISIBILITY
-    const __iter_pointer& __begin_node() const _NOEXCEPT {return __begin_node_;}
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type __alloc() const _NOEXCEPT
-        {return allocator_type(__node_alloc());}
-private:
-    _LIBCPP_INLINE_VISIBILITY
-          size_type& size() _NOEXCEPT {return __pair3_.first();}
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    const size_type& size() const _NOEXCEPT {return __pair3_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-          value_compare& value_comp() _NOEXCEPT {return __pair3_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const value_compare& value_comp() const _NOEXCEPT
-        {return __pair3_.second();}
-public:
-
-    _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __root() const _NOEXCEPT
-        {return static_cast<__node_pointer>(__end_node()->__left_);}
-
-    __node_base_pointer* __root_ptr() const _NOEXCEPT {
-        return _VSTD::addressof(__end_node()->__left_);
-    }
-
-    typedef __tree_iterator<value_type, __node_pointer, difference_type>             iterator;
-    typedef __tree_const_iterator<value_type, __node_pointer, difference_type> const_iterator;
-
-    explicit __tree(const value_compare& __comp)
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<__node_allocator>::value &&
-            is_nothrow_copy_constructible<value_compare>::value);
-    explicit __tree(const allocator_type& __a);
-    __tree(const value_compare& __comp, const allocator_type& __a);
-    __tree(const __tree& __t);
-    __tree& operator=(const __tree& __t);
-    template <class _InputIterator>
-        void __assign_unique(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        void __assign_multi(_InputIterator __first, _InputIterator __last);
-#ifndef _LIBCPP_CXX03_LANG
-    __tree(__tree&& __t)
-        _NOEXCEPT_(
-            is_nothrow_move_constructible<__node_allocator>::value &&
-            is_nothrow_move_constructible<value_compare>::value);
-    __tree(__tree&& __t, const allocator_type& __a);
-    __tree& operator=(__tree&& __t)
-        _NOEXCEPT_(
-            __node_traits::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<value_compare>::value &&
-            is_nothrow_move_assignable<__node_allocator>::value);
-#endif // _LIBCPP_CXX03_LANG
-
-    ~__tree();
-
-    _LIBCPP_INLINE_VISIBILITY
-          iterator begin()  _NOEXCEPT {return       iterator(__begin_node());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT {return const_iterator(__begin_node());}
-    _LIBCPP_INLINE_VISIBILITY
-          iterator end() _NOEXCEPT {return       iterator(__end_node());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT {return const_iterator(__end_node());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT
-        {return std::min<size_type>(
-                __node_traits::max_size(__node_alloc()),
-                numeric_limits<difference_type >::max());}
-
-    void clear() _NOEXCEPT;
-
-    void swap(__tree& __t)
-#if _LIBCPP_STD_VER <= 11
-        _NOEXCEPT_(
-            __is_nothrow_swappable<value_compare>::value
-            && (!__node_traits::propagate_on_container_swap::value ||
-                 __is_nothrow_swappable<__node_allocator>::value)
-            );
-#else
-        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value);
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Key, class ..._Args>
-    pair<iterator, bool>
-    __emplace_unique_key_args(_Key const&, _Args&&... __args);
-    template <class _Key, class ..._Args>
-    iterator
-    __emplace_hint_unique_key_args(const_iterator, _Key const&, _Args&&...);
-
-    template <class... _Args>
-    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);
-
-    template <class... _Args>
-    iterator __emplace_hint_unique_impl(const_iterator __p, _Args&&... __args);
-
-    template <class... _Args>
-    iterator __emplace_multi(_Args&&... __args);
-
-    template <class... _Args>
-    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique(_Pp&& __x) {
-        return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x),
-                                            __can_extract_key<_Pp, key_type>());
-    }
-
-    template <class _First, class _Second>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<
-        __can_extract_map_key<_First, key_type, __container_value_type>::value,
-        pair<iterator, bool>
-    >::type __emplace_unique(_First&& __f, _Second&& __s) {
-        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f),
-                                              _VSTD::forward<_Second>(__s));
-    }
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique(_Args&&... __args) {
-        return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) {
-      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) {
-      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) {
-      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __emplace_hint_unique(const_iterator __p, _Pp&& __x) {
-        return __emplace_hint_unique_extract_key(__p, _VSTD::forward<_Pp>(__x),
-                                            __can_extract_key<_Pp, key_type>());
-    }
-
-    template <class _First, class _Second>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<
-        __can_extract_map_key<_First, key_type, __container_value_type>::value,
-        iterator
-    >::type __emplace_hint_unique(const_iterator __p, _First&& __f, _Second&& __s) {
-        return __emplace_hint_unique_key_args(__p, __f,
-                                              _VSTD::forward<_First>(__f),
-                                              _VSTD::forward<_Second>(__s));
-    }
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __emplace_hint_unique(const_iterator __p, _Args&&... __args) {
-        return __emplace_hint_unique_impl(__p, _VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator
-    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_fail_tag) {
-      return __emplace_hint_unique_impl(__p, _VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator
-    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_self_tag) {
-      return __emplace_hint_unique_key_args(__p, __x, _VSTD::forward<_Pp>(__x));
-    }
-
-    template <class _Pp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator
-    __emplace_hint_unique_extract_key(const_iterator __p, _Pp&& __x, __extract_key_first_tag) {
-      return __emplace_hint_unique_key_args(__p, __x.first, _VSTD::forward<_Pp>(__x));
-    }
-
-#else
-    template <class _Key, class _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __emplace_unique_key_args(_Key const&, _Args& __args);
-    template <class _Key, class _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __emplace_hint_unique_key_args(const_iterator, _Key const&, _Args&);
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __insert_unique(const __container_value_type& __v) {
-        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_unique(const_iterator __p, const __container_value_type& __v) {
-        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), __v);
-    }
-
-#ifdef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(const __container_value_type& __v);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(const_iterator __p, const __container_value_type& __v);
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __insert_unique(__container_value_type&& __v) {
-        return __emplace_unique_key_args(_NodeTypes::__get_key(__v), _VSTD::move(__v));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_unique(const_iterator __p, __container_value_type&& __v) {
-        return __emplace_hint_unique_key_args(__p, _NodeTypes::__get_key(__v), _VSTD::move(__v));
-    }
-
-    template <class _Vp, class = typename enable_if<
-            !is_same<typename __unconstref<_Vp>::type,
-                     __container_value_type
-            >::value
-        >::type>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __insert_unique(_Vp&& __v) {
-        return __emplace_unique(_VSTD::forward<_Vp>(__v));
-    }
-
-    template <class _Vp, class = typename enable_if<
-            !is_same<typename __unconstref<_Vp>::type,
-                     __container_value_type
-            >::value
-        >::type>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_unique(const_iterator __p, _Vp&& __v) {
-        return __emplace_hint_unique(__p, _VSTD::forward<_Vp>(__v));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(__container_value_type&& __v) {
-        return __emplace_multi(_VSTD::move(__v));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(const_iterator __p, __container_value_type&& __v) {
-        return __emplace_hint_multi(__p, _VSTD::move(__v));
-    }
-
-    template <class _Vp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(_Vp&& __v) {
-        return __emplace_multi(_VSTD::forward<_Vp>(__v));
-    }
-
-    template <class _Vp>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __insert_multi(const_iterator __p, _Vp&& __v) {
-        return __emplace_hint_multi(__p, _VSTD::forward<_Vp>(__v));
-    }
-
-#endif // !_LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator             __node_insert_unique(const_iterator __p,
-                                              __node_pointer __nd);
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_insert_multi(__node_pointer __nd);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_insert_multi(const_iterator __p, __node_pointer __nd);
-
-
-    _LIBCPP_INLINE_VISIBILITY iterator
-    __remove_node_pointer(__node_pointer) _NOEXCEPT;
-
-#if _LIBCPP_STD_VER > 14
-    template <class _NodeHandle, class _InsertReturnType>
-    _LIBCPP_INLINE_VISIBILITY
-    _InsertReturnType __node_handle_insert_unique(_NodeHandle&&);
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_handle_insert_unique(const_iterator, _NodeHandle&&);
-    template <class _Tree>
-    _LIBCPP_INLINE_VISIBILITY
-    void __node_handle_merge_unique(_Tree& __source);
-
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_handle_insert_multi(_NodeHandle&&);
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __node_handle_insert_multi(const_iterator, _NodeHandle&&);
-    template <class _Tree>
-    _LIBCPP_INLINE_VISIBILITY
-    void __node_handle_merge_multi(_Tree& __source);
-
-
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    _NodeHandle __node_handle_extract(key_type const&);
-    template <class _NodeHandle>
-    _LIBCPP_INLINE_VISIBILITY
-    _NodeHandle __node_handle_extract(const_iterator);
-#endif
-
-    iterator erase(const_iterator __p);
-    iterator erase(const_iterator __f, const_iterator __l);
-    template <class _Key>
-        size_type __erase_unique(const _Key& __k);
-    template <class _Key>
-        size_type __erase_multi(const _Key& __k);
-
-    void __insert_node_at(__parent_pointer     __parent,
-                          __node_base_pointer& __child,
-                          __node_base_pointer __new_node) _NOEXCEPT;
-
-    template <class _Key>
-        iterator find(const _Key& __v);
-    template <class _Key>
-        const_iterator find(const _Key& __v) const;
-
-    template <class _Key>
-        size_type __count_unique(const _Key& __k) const;
-    template <class _Key>
-        size_type __count_multi(const _Key& __k) const;
-
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator lower_bound(const _Key& __v)
-            {return __lower_bound(__v, __root(), __end_node());}
-    template <class _Key>
-        iterator __lower_bound(const _Key& __v,
-                               __node_pointer __root,
-                               __iter_pointer __result);
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        const_iterator lower_bound(const _Key& __v) const
-            {return __lower_bound(__v, __root(), __end_node());}
-    template <class _Key>
-        const_iterator __lower_bound(const _Key& __v,
-                                     __node_pointer __root,
-                                     __iter_pointer __result) const;
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator upper_bound(const _Key& __v)
-            {return __upper_bound(__v, __root(), __end_node());}
-    template <class _Key>
-        iterator __upper_bound(const _Key& __v,
-                               __node_pointer __root,
-                               __iter_pointer __result);
-    template <class _Key>
-        _LIBCPP_INLINE_VISIBILITY
-        const_iterator upper_bound(const _Key& __v) const
-            {return __upper_bound(__v, __root(), __end_node());}
-    template <class _Key>
-        const_iterator __upper_bound(const _Key& __v,
-                                     __node_pointer __root,
-                                     __iter_pointer __result) const;
-    template <class _Key>
-        pair<iterator, iterator>
-        __equal_range_unique(const _Key& __k);
-    template <class _Key>
-        pair<const_iterator, const_iterator>
-        __equal_range_unique(const _Key& __k) const;
-
-    template <class _Key>
-        pair<iterator, iterator>
-        __equal_range_multi(const _Key& __k);
-    template <class _Key>
-        pair<const_iterator, const_iterator>
-        __equal_range_multi(const _Key& __k) const;
-
-    typedef __tree_node_destructor<__node_allocator> _Dp;
-    typedef unique_ptr<__node, _Dp> __node_holder;
-
-    __node_holder remove(const_iterator __p) _NOEXCEPT;
-private:
-    __node_base_pointer&
-        __find_leaf_low(__parent_pointer& __parent, const key_type& __v);
-    __node_base_pointer&
-        __find_leaf_high(__parent_pointer& __parent, const key_type& __v);
-    __node_base_pointer&
-        __find_leaf(const_iterator __hint,
-                    __parent_pointer& __parent, const key_type& __v);
-    // FIXME: Make this function const qualified. Unfortunetly doing so
-    // breaks existing code which uses non-const callable comparators.
-    template <class _Key>
-    __node_base_pointer&
-        __find_equal(__parent_pointer& __parent, const _Key& __v);
-    template <class _Key>
-    _LIBCPP_INLINE_VISIBILITY __node_base_pointer&
-    __find_equal(__parent_pointer& __parent, const _Key& __v) const {
-      return const_cast<__tree*>(this)->__find_equal(__parent, __v);
-    }
-    template <class _Key>
-    __node_base_pointer&
-        __find_equal(const_iterator __hint, __parent_pointer& __parent,
-                     __node_base_pointer& __dummy,
-                     const _Key& __v);
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class ..._Args>
-    __node_holder __construct_node(_Args&& ...__args);
-#else
-    __node_holder __construct_node(const __container_value_type& __v);
-#endif
-
-    void destroy(__node_pointer __nd) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __tree& __t)
-        {__copy_assign_alloc(__t, integral_constant<bool,
-             __node_traits::propagate_on_container_copy_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __tree& __t, true_type)
-        {
-        if (__node_alloc() != __t.__node_alloc())
-            clear();
-        __node_alloc() = __t.__node_alloc();
-        }
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __tree&, false_type) {}
-
-    void __move_assign(__tree& __t, false_type);
-    void __move_assign(__tree& __t, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value &&
-                   is_nothrow_move_assignable<__node_allocator>::value);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__tree& __t)
-        _NOEXCEPT_(
-            !__node_traits::propagate_on_container_move_assignment::value ||
-            is_nothrow_move_assignable<__node_allocator>::value)
-        {__move_assign_alloc(__t, integral_constant<bool,
-             __node_traits::propagate_on_container_move_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__tree& __t, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
-        {__node_alloc() = _VSTD::move(__t.__node_alloc());}
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__tree&, false_type) _NOEXCEPT {}
-
-    __node_pointer __detach();
-    static __node_pointer __detach(__node_pointer);
-
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
-};
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp)
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<__node_allocator>::value &&
-            is_nothrow_copy_constructible<value_compare>::value)
-    : __pair3_(0, __comp)
-{
-    __begin_node() = __end_node();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(const allocator_type& __a)
-    : __begin_node_(__iter_pointer()),
-      __pair1_(__second_tag(), __node_allocator(__a)),
-      __pair3_(0)
-{
-    __begin_node() = __end_node();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(const value_compare& __comp,
-                                           const allocator_type& __a)
-    : __begin_node_(__iter_pointer()),
-      __pair1_(__second_tag(), __node_allocator(__a)),
-      __pair3_(0, __comp)
-{
-    __begin_node() = __end_node();
-}
-
-// Precondition:  size() != 0
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
-__tree<_Tp, _Compare, _Allocator>::__detach()
-{
-    __node_pointer __cache = static_cast<__node_pointer>(__begin_node());
-    __begin_node() = __end_node();
-    __end_node()->__left_->__parent_ = nullptr;
-    __end_node()->__left_ = nullptr;
-    size() = 0;
-    // __cache->__left_ == nullptr
-    if (__cache->__right_ != nullptr)
-        __cache = static_cast<__node_pointer>(__cache->__right_);
-    // __cache->__left_ == nullptr
-    // __cache->__right_ == nullptr
-    return __cache;
-}
-
-// Precondition:  __cache != nullptr
-//    __cache->left_ == nullptr
-//    __cache->right_ == nullptr
-//    This is no longer a red-black tree
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_pointer
-__tree<_Tp, _Compare, _Allocator>::__detach(__node_pointer __cache)
-{
-    if (__cache->__parent_ == nullptr)
-        return nullptr;
-    if (__tree_is_left_child(static_cast<__node_base_pointer>(__cache)))
-    {
-        __cache->__parent_->__left_ = nullptr;
-        __cache = static_cast<__node_pointer>(__cache->__parent_);
-        if (__cache->__right_ == nullptr)
-            return __cache;
-        return static_cast<__node_pointer>(__tree_leaf(__cache->__right_));
-    }
-    // __cache is right child
-    __cache->__parent_unsafe()->__right_ = nullptr;
-    __cache = static_cast<__node_pointer>(__cache->__parent_);
-    if (__cache->__left_ == nullptr)
-        return __cache;
-    return static_cast<__node_pointer>(__tree_leaf(__cache->__left_));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>&
-__tree<_Tp, _Compare, _Allocator>::operator=(const __tree& __t)
-{
-    if (this != &__t)
-    {
-        value_comp() = __t.value_comp();
-        __copy_assign_alloc(__t);
-        __assign_multi(__t.begin(), __t.end());
-    }
-    return *this;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _InputIterator>
-void
-__tree<_Tp, _Compare, _Allocator>::__assign_unique(_InputIterator __first, _InputIterator __last)
-{
-    typedef iterator_traits<_InputIterator> _ITraits;
-    typedef typename _ITraits::value_type _ItValueType;
-    static_assert((is_same<_ItValueType, __container_value_type>::value),
-                  "__assign_unique may only be called with the containers value type");
-
-    if (size() != 0)
-    {
-        __node_pointer __cache = __detach();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (; __cache != nullptr && __first != __last; ++__first)
-            {
-                __cache->__value_ = *__first;
-                __node_pointer __next = __detach(__cache);
-                __node_insert_unique(__cache);
-                __cache = __next;
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (__cache->__parent_ != nullptr)
-                __cache = static_cast<__node_pointer>(__cache->__parent_);
-            destroy(__cache);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        if (__cache != nullptr)
-        {
-            while (__cache->__parent_ != nullptr)
-                __cache = static_cast<__node_pointer>(__cache->__parent_);
-            destroy(__cache);
-        }
-    }
-    for (; __first != __last; ++__first)
-        __insert_unique(*__first);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _InputIterator>
-void
-__tree<_Tp, _Compare, _Allocator>::__assign_multi(_InputIterator __first, _InputIterator __last)
-{
-    typedef iterator_traits<_InputIterator> _ITraits;
-    typedef typename _ITraits::value_type _ItValueType;
-    static_assert((is_same<_ItValueType, __container_value_type>::value ||
-                  is_same<_ItValueType, __node_value_type>::value),
-                  "__assign_multi may only be called with the containers value type"
-                  " or the nodes value type");
-    if (size() != 0)
-    {
-        __node_pointer __cache = __detach();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (; __cache != nullptr && __first != __last; ++__first)
-            {
-                __cache->__value_ = *__first;
-                __node_pointer __next = __detach(__cache);
-                __node_insert_multi(__cache);
-                __cache = __next;
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (__cache->__parent_ != nullptr)
-                __cache = static_cast<__node_pointer>(__cache->__parent_);
-            destroy(__cache);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        if (__cache != nullptr)
-        {
-            while (__cache->__parent_ != nullptr)
-                __cache = static_cast<__node_pointer>(__cache->__parent_);
-            destroy(__cache);
-        }
-    }
-    for (; __first != __last; ++__first)
-        __insert_multi(_NodeTypes::__get_value(*__first));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(const __tree& __t)
-    : __begin_node_(__iter_pointer()),
-      __pair1_(__second_tag(), __node_traits::select_on_container_copy_construction(__t.__node_alloc())),
-      __pair3_(0, __t.value_comp())
-{
-    __begin_node() = __end_node();
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t)
-    _NOEXCEPT_(
-        is_nothrow_move_constructible<__node_allocator>::value &&
-        is_nothrow_move_constructible<value_compare>::value)
-    : __begin_node_(_VSTD::move(__t.__begin_node_)),
-      __pair1_(_VSTD::move(__t.__pair1_)),
-      __pair3_(_VSTD::move(__t.__pair3_))
-{
-    if (size() == 0)
-        __begin_node() = __end_node();
-    else
-    {
-        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
-        __t.__begin_node() = __t.__end_node();
-        __t.__end_node()->__left_ = nullptr;
-        __t.size() = 0;
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::__tree(__tree&& __t, const allocator_type& __a)
-    : __pair1_(__second_tag(), __node_allocator(__a)),
-      __pair3_(0, _VSTD::move(__t.value_comp()))
-{
-    if (__a == __t.__alloc())
-    {
-        if (__t.size() == 0)
-            __begin_node() = __end_node();
-        else
-        {
-            __begin_node() = __t.__begin_node();
-            __end_node()->__left_ = __t.__end_node()->__left_;
-            __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
-            size() = __t.size();
-            __t.__begin_node() = __t.__end_node();
-            __t.__end_node()->__left_ = nullptr;
-            __t.size() = 0;
-        }
-    }
-    else
-    {
-        __begin_node() = __end_node();
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, true_type)
-    _NOEXCEPT_(is_nothrow_move_assignable<value_compare>::value &&
-               is_nothrow_move_assignable<__node_allocator>::value)
-{
-    destroy(static_cast<__node_pointer>(__end_node()->__left_));
-    __begin_node_ = __t.__begin_node_;
-    __pair1_.first() = __t.__pair1_.first();
-    __move_assign_alloc(__t);
-    __pair3_ = _VSTD::move(__t.__pair3_);
-    if (size() == 0)
-        __begin_node() = __end_node();
-    else
-    {
-        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
-        __t.__begin_node() = __t.__end_node();
-        __t.__end_node()->__left_ = nullptr;
-        __t.size() = 0;
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::__move_assign(__tree& __t, false_type)
-{
-    if (__node_alloc() == __t.__node_alloc())
-        __move_assign(__t, true_type());
-    else
-    {
-        value_comp() = _VSTD::move(__t.value_comp());
-        const_iterator __e = end();
-        if (size() != 0)
-        {
-            __node_pointer __cache = __detach();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-            try
-            {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-                while (__cache != nullptr && __t.size() != 0)
-                {
-                    __cache->__value_ = _VSTD::move(__t.remove(__t.begin())->__value_);
-                    __node_pointer __next = __detach(__cache);
-                    __node_insert_multi(__cache);
-                    __cache = __next;
-                }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-            }
-            catch (...)
-            {
-                while (__cache->__parent_ != nullptr)
-                    __cache = static_cast<__node_pointer>(__cache->__parent_);
-                destroy(__cache);
-                throw;
-            }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            if (__cache != nullptr)
-            {
-                while (__cache->__parent_ != nullptr)
-                    __cache = static_cast<__node_pointer>(__cache->__parent_);
-                destroy(__cache);
-            }
-        }
-        while (__t.size() != 0)
-            __insert_multi(__e, _NodeTypes::__move(__t.remove(__t.begin())->__value_));
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>&
-__tree<_Tp, _Compare, _Allocator>::operator=(__tree&& __t)
-    _NOEXCEPT_(
-        __node_traits::propagate_on_container_move_assignment::value &&
-        is_nothrow_move_assignable<value_compare>::value &&
-        is_nothrow_move_assignable<__node_allocator>::value)
-
-{
-    __move_assign(__t, integral_constant<bool,
-                  __node_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Compare, class _Allocator>
-__tree<_Tp, _Compare, _Allocator>::~__tree()
-{
-    static_assert((is_copy_constructible<value_compare>::value),
-                 "Comparator must be copy-constructible.");
-  destroy(__root());
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::destroy(__node_pointer __nd) _NOEXCEPT
-{
-    if (__nd != nullptr)
-    {
-        destroy(static_cast<__node_pointer>(__nd->__left_));
-        destroy(static_cast<__node_pointer>(__nd->__right_));
-        __node_allocator& __na = __node_alloc();
-        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__nd->__value_));
-        __node_traits::deallocate(__na, __nd, 1);
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::swap(__tree& __t)
-#if _LIBCPP_STD_VER <= 11
-        _NOEXCEPT_(
-            __is_nothrow_swappable<value_compare>::value
-            && (!__node_traits::propagate_on_container_swap::value ||
-                 __is_nothrow_swappable<__node_allocator>::value)
-            )
-#else
-        _NOEXCEPT_(__is_nothrow_swappable<value_compare>::value)
-#endif
-{
-    using _VSTD::swap;
-    swap(__begin_node_, __t.__begin_node_);
-    swap(__pair1_.first(), __t.__pair1_.first());
-    __swap_allocator(__node_alloc(), __t.__node_alloc());
-    __pair3_.swap(__t.__pair3_);
-    if (size() == 0)
-        __begin_node() = __end_node();
-    else
-        __end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__end_node());
-    if (__t.size() == 0)
-        __t.__begin_node() = __t.__end_node();
-    else
-        __t.__end_node()->__left_->__parent_ = static_cast<__parent_pointer>(__t.__end_node());
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void
-__tree<_Tp, _Compare, _Allocator>::clear() _NOEXCEPT
-{
-    destroy(__root());
-    size() = 0;
-    __begin_node() = __end_node();
-    __end_node()->__left_ = nullptr;
-}
-
-// Find lower_bound place to insert
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_leaf_low(__parent_pointer& __parent,
-                                                   const key_type& __v)
-{
-    __node_pointer __nd = __root();
-    if (__nd != nullptr)
-    {
-        while (true)
-        {
-            if (value_comp()(__nd->__value_, __v))
-            {
-                if (__nd->__right_ != nullptr)
-                    __nd = static_cast<__node_pointer>(__nd->__right_);
-                else
-                {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __nd->__right_;
-                }
-            }
-            else
-            {
-                if (__nd->__left_ != nullptr)
-                    __nd = static_cast<__node_pointer>(__nd->__left_);
-                else
-                {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __parent->__left_;
-                }
-            }
-        }
-    }
-    __parent = static_cast<__parent_pointer>(__end_node());
-    return __parent->__left_;
-}
-
-// Find upper_bound place to insert
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_leaf_high(__parent_pointer& __parent,
-                                                    const key_type& __v)
-{
-    __node_pointer __nd = __root();
-    if (__nd != nullptr)
-    {
-        while (true)
-        {
-            if (value_comp()(__v, __nd->__value_))
-            {
-                if (__nd->__left_ != nullptr)
-                    __nd = static_cast<__node_pointer>(__nd->__left_);
-                else
-                {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __parent->__left_;
-                }
-            }
-            else
-            {
-                if (__nd->__right_ != nullptr)
-                    __nd = static_cast<__node_pointer>(__nd->__right_);
-                else
-                {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __nd->__right_;
-                }
-            }
-        }
-    }
-    __parent = static_cast<__parent_pointer>(__end_node());
-    return __parent->__left_;
-}
-
-// Find leaf place to insert closest to __hint
-// First check prior to __hint.
-// Next check after __hint.
-// Next do O(log N) search.
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_leaf(const_iterator __hint,
-                                               __parent_pointer& __parent,
-                                               const key_type& __v)
-{
-    if (__hint == end() || !value_comp()(*__hint, __v))  // check before
-    {
-        // __v <= *__hint
-        const_iterator __prior = __hint;
-        if (__prior == begin() || !value_comp()(__v, *--__prior))
-        {
-            // *prev(__hint) <= __v <= *__hint
-            if (__hint.__ptr_->__left_ == nullptr)
-            {
-                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
-                return __parent->__left_;
-            }
-            else
-            {
-                __parent = static_cast<__parent_pointer>(__prior.__ptr_);
-                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_;
-            }
-        }
-        // __v < *prev(__hint)
-        return __find_leaf_high(__parent, __v);
-    }
-    // else __v > *__hint
-    return __find_leaf_low(__parent, __v);
-}
-
-// Find place to insert if __v doesn't exist
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-// If __v exists, set parent to node of __v and return reference to node of __v
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_equal(__parent_pointer& __parent,
-                                                const _Key& __v)
-{
-    __node_pointer __nd = __root();
-    __node_base_pointer* __nd_ptr = __root_ptr();
-    if (__nd != nullptr)
-    {
-        while (true)
-        {
-            if (value_comp()(__v, __nd->__value_))
-            {
-                if (__nd->__left_ != nullptr) {
-                    __nd_ptr = _VSTD::addressof(__nd->__left_);
-                    __nd = static_cast<__node_pointer>(__nd->__left_);
-                } else {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __parent->__left_;
-                }
-            }
-            else if (value_comp()(__nd->__value_, __v))
-            {
-                if (__nd->__right_ != nullptr) {
-                    __nd_ptr = _VSTD::addressof(__nd->__right_);
-                    __nd = static_cast<__node_pointer>(__nd->__right_);
-                } else {
-                    __parent = static_cast<__parent_pointer>(__nd);
-                    return __nd->__right_;
-                }
-            }
-            else
-            {
-                __parent = static_cast<__parent_pointer>(__nd);
-                return *__nd_ptr;
-            }
-        }
-    }
-    __parent = static_cast<__parent_pointer>(__end_node());
-    return __parent->__left_;
-}
-
-// Find place to insert if __v doesn't exist
-// First check prior to __hint.
-// Next check after __hint.
-// Next do O(log N) search.
-// Set __parent to parent of null leaf
-// Return reference to null leaf
-// If __v exists, set parent to node of __v and return reference to node of __v
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::__node_base_pointer&
-__tree<_Tp, _Compare, _Allocator>::__find_equal(const_iterator __hint,
-                                                __parent_pointer& __parent,
-                                                __node_base_pointer& __dummy,
-                                                const _Key& __v)
-{
-    if (__hint == end() || value_comp()(__v, *__hint))  // check before
-    {
-        // __v < *__hint
-        const_iterator __prior = __hint;
-        if (__prior == begin() || value_comp()(*--__prior, __v))
-        {
-            // *prev(__hint) < __v < *__hint
-            if (__hint.__ptr_->__left_ == nullptr)
-            {
-                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
-                return __parent->__left_;
-            }
-            else
-            {
-                __parent = static_cast<__parent_pointer>(__prior.__ptr_);
-                return static_cast<__node_base_pointer>(__prior.__ptr_)->__right_;
-            }
-        }
-        // __v <= *prev(__hint)
-        return __find_equal(__parent, __v);
-    }
-    else if (value_comp()(*__hint, __v))  // check after
-    {
-        // *__hint < __v
-        const_iterator __next = _VSTD::next(__hint);
-        if (__next == end() || value_comp()(__v, *__next))
-        {
-            // *__hint < __v < *_VSTD::next(__hint)
-            if (__hint.__get_np()->__right_ == nullptr)
-            {
-                __parent = static_cast<__parent_pointer>(__hint.__ptr_);
-                return static_cast<__node_base_pointer>(__hint.__ptr_)->__right_;
-            }
-            else
-            {
-                __parent = static_cast<__parent_pointer>(__next.__ptr_);
-                return __parent->__left_;
-            }
-        }
-        // *next(__hint) <= __v
-        return __find_equal(__parent, __v);
-    }
-    // else __v == *__hint
-    __parent = static_cast<__parent_pointer>(__hint.__ptr_);
-    __dummy = static_cast<__node_base_pointer>(__hint.__ptr_);
-    return __dummy;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-void __tree<_Tp, _Compare, _Allocator>::__insert_node_at(
-    __parent_pointer __parent, __node_base_pointer& __child,
-    __node_base_pointer __new_node) _NOEXCEPT
-{
-    __new_node->__left_   = nullptr;
-    __new_node->__right_  = nullptr;
-    __new_node->__parent_ = __parent;
-    // __new_node->__is_black_ is initialized in __tree_balance_after_insert
-    __child = __new_node;
-    if (__begin_node()->__left_ != nullptr)
-        __begin_node() = static_cast<__iter_pointer>(__begin_node()->__left_);
-    __tree_balance_after_insert(__end_node()->__left_, __child);
-    ++size();
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key, class... _Args>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args)
-#else
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key, class _Args>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__emplace_unique_key_args(_Key const& __k, _Args& __args)
-#endif
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__parent, __k);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    bool __inserted = false;
-    if (__child == nullptr)
-    {
-#ifndef _LIBCPP_CXX03_LANG
-        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-#else
-        __node_holder __h = __construct_node(__args);
-#endif
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-        __inserted = true;
-    }
-    return pair<iterator, bool>(iterator(__r), __inserted);
-}
-
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key, class... _Args>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_key_args(
-    const_iterator __p, _Key const& __k, _Args&&... __args)
-#else
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key, class _Args>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_key_args(
-    const_iterator __p, _Key const& __k, _Args& __args)
-#endif
-{
-    __parent_pointer __parent;
-    __node_base_pointer __dummy;
-    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __k);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    if (__child == nullptr)
-    {
-#ifndef _LIBCPP_CXX03_LANG
-        __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-#else
-        __node_holder __h = __construct_node(__args);
-#endif
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-    }
-    return iterator(__r);
-}
-
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class ..._Args>
-typename __tree<_Tp, _Compare, _Allocator>::__node_holder
-__tree<_Tp, _Compare, _Allocator>::__construct_node(_Args&& ...__args)
-{
-    static_assert(!__is_tree_value_type<_Args...>::value,
-                  "Cannot construct from __value_type");
-    __node_allocator& __na = __node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...);
-    __h.get_deleter().__value_constructed = true;
-    return __h;
-}
-
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class... _Args>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__emplace_unique_impl(_Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__parent, __h->__value_);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    bool __inserted = false;
-    if (__child == nullptr)
-    {
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-        __inserted = true;
-    }
-    return pair<iterator, bool>(iterator(__r), __inserted);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class... _Args>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__emplace_hint_unique_impl(const_iterator __p, _Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __parent_pointer __parent;
-    __node_base_pointer __dummy;
-    __node_base_pointer& __child = __find_equal(__p, __parent, __dummy, __h->__value_);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    if (__child == nullptr)
-    {
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-    }
-    return iterator(__r);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class... _Args>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__emplace_multi(_Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__h->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(static_cast<__node_pointer>(__h.release()));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class... _Args>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__emplace_hint_multi(const_iterator __p,
-                                                        _Args&&... __args)
-{
-    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__h->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(static_cast<__node_pointer>(__h.release()));
-}
-
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_holder
-__tree<_Tp, _Compare, _Allocator>::__construct_node(const __container_value_type& __v)
-{
-    __node_allocator& __na = __node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), __v);
-    __h.get_deleter().__value_constructed = true;
-    return _LIBCPP_EXPLICIT_MOVE(__h);  // explicitly moved for C++03
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#ifdef _LIBCPP_CXX03_LANG
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_multi(const __container_value_type& __v)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__v));
-    __node_holder __h = __construct_node(__v);
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(__h.release());
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__insert_multi(const_iterator __p, const __container_value_type& __v)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__v));
-    __node_holder __h = __construct_node(__v);
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-    return iterator(__h.release());
-}
-#endif
-
-template <class _Tp, class _Compare, class _Allocator>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator, bool>
-__tree<_Tp, _Compare, _Allocator>::__node_insert_unique(__node_pointer __nd)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__parent, __nd->__value_);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    bool __inserted = false;
-    if (__child == nullptr)
-    {
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
-        __r = __nd;
-        __inserted = true;
-    }
-    return pair<iterator, bool>(iterator(__r), __inserted);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__node_insert_unique(const_iterator __p,
-                                                        __node_pointer __nd)
-{
-    __parent_pointer __parent;
-    __node_base_pointer __dummy;
-    __node_base_pointer& __child = __find_equal(__p, __parent, __nd->__value_);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    if (__child == nullptr)
-    {
-        __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
-        __r = __nd;
-    }
-    return iterator(__r);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(__node_pointer __nd)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(__parent, _NodeTypes::__get_key(__nd->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
-    return iterator(__nd);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__node_insert_multi(const_iterator __p,
-                                                       __node_pointer __nd)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__p, __parent, _NodeTypes::__get_key(__nd->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__nd));
-    return iterator(__nd);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__remove_node_pointer(__node_pointer __ptr) _NOEXCEPT
-{
-    iterator __r(__ptr);
-    ++__r;
-    if (__begin_node() == __ptr)
-        __begin_node() = __r.__ptr_;
-    --size();
-    __tree_remove(__end_node()->__left_,
-                  static_cast<__node_base_pointer>(__ptr));
-    return __r;
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp, class _Compare, class _Allocator>
-template <class _NodeHandle, class _InsertReturnType>
-_LIBCPP_INLINE_VISIBILITY
-_InsertReturnType
-__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
-    _NodeHandle&& __nh)
-{
-    if (__nh.empty())
-        return _InsertReturnType{end(), false, _NodeHandle()};
-
-    __node_pointer __ptr = __nh.__ptr_;
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_equal(__parent,
-                                                __ptr->__value_);
-    if (__child != nullptr)
-        return _InsertReturnType{
-            iterator(static_cast<__node_pointer>(__child)),
-            false, _VSTD::move(__nh)};
-
-    __insert_node_at(__parent, __child,
-                     static_cast<__node_base_pointer>(__ptr));
-    __nh.__release();
-    return _InsertReturnType{iterator(__ptr), true, _NodeHandle()};
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_unique(
-    const_iterator __hint, _NodeHandle&& __nh)
-{
-    if (__nh.empty())
-        return end();
-
-    __node_pointer __ptr = __nh.__ptr_;
-    __parent_pointer __parent;
-    __node_base_pointer __dummy;
-    __node_base_pointer& __child = __find_equal(__hint, __parent, __dummy,
-                                                __ptr->__value_);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    if (__child == nullptr)
-    {
-        __insert_node_at(__parent, __child,
-                         static_cast<__node_base_pointer>(__ptr));
-        __r = __ptr;
-        __nh.__release();
-    }
-    return iterator(__r);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-_NodeHandle
-__tree<_Tp, _Compare, _Allocator>::__node_handle_extract(key_type const& __key)
-{
-    iterator __it = find(__key);
-    if (__it == end())
-        return _NodeHandle();
-    return __node_handle_extract<_NodeHandle>(__it);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-_NodeHandle
-__tree<_Tp, _Compare, _Allocator>::__node_handle_extract(const_iterator __p)
-{
-    __node_pointer __np = __p.__get_np();
-    __remove_node_pointer(__np);
-    return _NodeHandle(__np, __alloc());
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Tree>
-_LIBCPP_INLINE_VISIBILITY
-void
-__tree<_Tp, _Compare, _Allocator>::__node_handle_merge_unique(_Tree& __source)
-{
-    static_assert(is_same<typename _Tree::__node_pointer, __node_pointer>::value, "");
-
-    for (typename _Tree::iterator __i = __source.begin();
-         __i != __source.end();)
-    {
-        __node_pointer __src_ptr = __i.__get_np();
-        __parent_pointer __parent;
-        __node_base_pointer& __child =
-            __find_equal(__parent, _NodeTypes::__get_key(__src_ptr->__value_));
-        ++__i;
-        if (__child != nullptr)
-            continue;
-        __source.__remove_node_pointer(__src_ptr);
-        __insert_node_at(__parent, __child,
-                         static_cast<__node_base_pointer>(__src_ptr));
-    }
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(_NodeHandle&& __nh)
-{
-    if (__nh.empty())
-        return end();
-    __node_pointer __ptr = __nh.__ptr_;
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf_high(
-        __parent, _NodeTypes::__get_key(__ptr->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
-    __nh.__release();
-    return iterator(__ptr);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _NodeHandle>
-_LIBCPP_INLINE_VISIBILITY
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__node_handle_insert_multi(
-    const_iterator __hint, _NodeHandle&& __nh)
-{
-    if (__nh.empty())
-        return end();
-
-    __node_pointer __ptr = __nh.__ptr_;
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __find_leaf(__hint, __parent,
-                                               _NodeTypes::__get_key(__ptr->__value_));
-    __insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__ptr));
-    __nh.__release();
-    return iterator(__ptr);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Tree>
-_LIBCPP_INLINE_VISIBILITY
-void
-__tree<_Tp, _Compare, _Allocator>::__node_handle_merge_multi(_Tree& __source)
-{
-    static_assert(is_same<typename _Tree::__node_pointer, __node_pointer>::value, "");
-
-    for (typename _Tree::iterator __i = __source.begin();
-         __i != __source.end();)
-    {
-        __node_pointer __src_ptr = __i.__get_np();
-        __parent_pointer __parent;
-        __node_base_pointer& __child = __find_leaf_high(
-            __parent, _NodeTypes::__get_key(__src_ptr->__value_));
-        ++__i;
-        __source.__remove_node_pointer(__src_ptr);
-        __insert_node_at(__parent, __child,
-                         static_cast<__node_base_pointer>(__src_ptr));
-    }
-}
-
-#endif  // _LIBCPP_STD_VER > 14
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __p)
-{
-    __node_pointer __np = __p.__get_np();
-    iterator __r = __remove_node_pointer(__np);
-    __node_allocator& __na = __node_alloc();
-    __node_traits::destroy(__na, _NodeTypes::__get_ptr(
-        const_cast<__node_value_type&>(*__p)));
-    __node_traits::deallocate(__na, __np, 1);
-    return __r;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::erase(const_iterator __f, const_iterator __l)
-{
-    while (__f != __l)
-        __f = erase(__f);
-    return iterator(__l.__ptr_);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::size_type
-__tree<_Tp, _Compare, _Allocator>::__erase_unique(const _Key& __k)
-{
-    iterator __i = find(__k);
-    if (__i == end())
-        return 0;
-    erase(__i);
-    return 1;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::size_type
-__tree<_Tp, _Compare, _Allocator>::__erase_multi(const _Key& __k)
-{
-    pair<iterator, iterator> __p = __equal_range_multi(__k);
-    size_type __r = 0;
-    for (; __p.first != __p.second; ++__r)
-        __p.first = erase(__p.first);
-    return __r;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v)
-{
-    iterator __p = __lower_bound(__v, __root(), __end_node());
-    if (__p != end() && !value_comp()(__v, *__p))
-        return __p;
-    return end();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::const_iterator
-__tree<_Tp, _Compare, _Allocator>::find(const _Key& __v) const
-{
-    const_iterator __p = __lower_bound(__v, __root(), __end_node());
-    if (__p != end() && !value_comp()(__v, *__p))
-        return __p;
-    return end();
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::size_type
-__tree<_Tp, _Compare, _Allocator>::__count_unique(const _Key& __k) const
-{
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return 1;
-    }
-    return 0;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::size_type
-__tree<_Tp, _Compare, _Allocator>::__count_multi(const _Key& __k) const
-{
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _VSTD::distance(
-                __lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)),
-                __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result)
-            );
-    }
-    return 0;
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v,
-                                                 __node_pointer __root,
-                                                 __iter_pointer __result)
-{
-    while (__root != nullptr)
-    {
-        if (!value_comp()(__root->__value_, __v))
-        {
-            __result = static_cast<__iter_pointer>(__root);
-            __root = static_cast<__node_pointer>(__root->__left_);
-        }
-        else
-            __root = static_cast<__node_pointer>(__root->__right_);
-    }
-    return iterator(__result);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::const_iterator
-__tree<_Tp, _Compare, _Allocator>::__lower_bound(const _Key& __v,
-                                                 __node_pointer __root,
-                                                 __iter_pointer __result) const
-{
-    while (__root != nullptr)
-    {
-        if (!value_comp()(__root->__value_, __v))
-        {
-            __result = static_cast<__iter_pointer>(__root);
-            __root = static_cast<__node_pointer>(__root->__left_);
-        }
-        else
-            __root = static_cast<__node_pointer>(__root->__right_);
-    }
-    return const_iterator(__result);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::iterator
-__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v,
-                                                 __node_pointer __root,
-                                                 __iter_pointer __result)
-{
-    while (__root != nullptr)
-    {
-        if (value_comp()(__v, __root->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__root);
-            __root = static_cast<__node_pointer>(__root->__left_);
-        }
-        else
-            __root = static_cast<__node_pointer>(__root->__right_);
-    }
-    return iterator(__result);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-typename __tree<_Tp, _Compare, _Allocator>::const_iterator
-__tree<_Tp, _Compare, _Allocator>::__upper_bound(const _Key& __v,
-                                                 __node_pointer __root,
-                                                 __iter_pointer __result) const
-{
-    while (__root != nullptr)
-    {
-        if (value_comp()(__v, __root->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__root);
-            __root = static_cast<__node_pointer>(__root->__left_);
-        }
-        else
-            __root = static_cast<__node_pointer>(__root->__right_);
-    }
-    return const_iterator(__result);
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
-     typename __tree<_Tp, _Compare, _Allocator>::iterator>
-__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k)
-{
-    typedef pair<iterator, iterator> _Pp;
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _Pp(iterator(__rt),
-                      iterator(
-                          __rt->__right_ != nullptr ?
-                              static_cast<__iter_pointer>(__tree_min(__rt->__right_))
-                            : __result));
-    }
-    return _Pp(iterator(__result), iterator(__result));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
-     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
-__tree<_Tp, _Compare, _Allocator>::__equal_range_unique(const _Key& __k) const
-{
-    typedef pair<const_iterator, const_iterator> _Pp;
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _Pp(const_iterator(__rt),
-                      const_iterator(
-                          __rt->__right_ != nullptr ?
-                              static_cast<__iter_pointer>(__tree_min(__rt->__right_))
-                            : __result));
-    }
-    return _Pp(const_iterator(__result), const_iterator(__result));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-pair<typename __tree<_Tp, _Compare, _Allocator>::iterator,
-     typename __tree<_Tp, _Compare, _Allocator>::iterator>
-__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k)
-{
-    typedef pair<iterator, iterator> _Pp;
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)),
-                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
-    }
-    return _Pp(iterator(__result), iterator(__result));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-template <class _Key>
-pair<typename __tree<_Tp, _Compare, _Allocator>::const_iterator,
-     typename __tree<_Tp, _Compare, _Allocator>::const_iterator>
-__tree<_Tp, _Compare, _Allocator>::__equal_range_multi(const _Key& __k) const
-{
-    typedef pair<const_iterator, const_iterator> _Pp;
-    __iter_pointer __result = __end_node();
-    __node_pointer __rt = __root();
-    while (__rt != nullptr)
-    {
-        if (value_comp()(__k, __rt->__value_))
-        {
-            __result = static_cast<__iter_pointer>(__rt);
-            __rt = static_cast<__node_pointer>(__rt->__left_);
-        }
-        else if (value_comp()(__rt->__value_, __k))
-            __rt = static_cast<__node_pointer>(__rt->__right_);
-        else
-            return _Pp(__lower_bound(__k, static_cast<__node_pointer>(__rt->__left_), static_cast<__iter_pointer>(__rt)),
-                      __upper_bound(__k, static_cast<__node_pointer>(__rt->__right_), __result));
-    }
-    return _Pp(const_iterator(__result), const_iterator(__result));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-typename __tree<_Tp, _Compare, _Allocator>::__node_holder
-__tree<_Tp, _Compare, _Allocator>::remove(const_iterator __p) _NOEXCEPT
-{
-    __node_pointer __np = __p.__get_np();
-    if (__begin_node() == __p.__ptr_)
-    {
-        if (__np->__right_ != nullptr)
-            __begin_node() = static_cast<__iter_pointer>(__np->__right_);
-        else
-            __begin_node() = static_cast<__iter_pointer>(__np->__parent_);
-    }
-    --size();
-    __tree_remove(__end_node()->__left_,
-                  static_cast<__node_base_pointer>(__np));
-    return __node_holder(__np, _Dp(__node_alloc(), true));
-}
-
-template <class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__tree<_Tp, _Compare, _Allocator>& __x,
-     __tree<_Tp, _Compare, _Allocator>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP___TREE
diff --git a/lib/libcxx/include/__tuple b/lib/libcxx/include/__tuple
deleted file mode 100644
index 3b23d78afa1..00000000000
--- a/lib/libcxx/include/__tuple
+++ /dev/null
@@ -1,556 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP___TUPLE
-#define _LIBCPP___TUPLE
-
-#include <__config>
-#include <cstddef>
-#include <type_traits>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size;
-
-#if !defined(_LIBCPP_CXX03_LANG)
-template <class _Tp, class...>
-using __enable_if_tuple_size_imp = _Tp;
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp<
-    const _Tp,
-    typename enable_if<!is_volatile<_Tp>::value>::type,
-    integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
-    : public integral_constant<size_t, tuple_size<_Tp>::value> {};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp<
-    volatile _Tp,
-    typename enable_if<!is_const<_Tp>::value>::type,
-    integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
-    : public integral_constant<size_t, tuple_size<_Tp>::value> {};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS tuple_size<__enable_if_tuple_size_imp<
-    const volatile _Tp,
-    integral_constant<size_t, sizeof(tuple_size<_Tp>)>>>
-    : public integral_constant<size_t, tuple_size<_Tp>::value> {};
-
-#else
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size<const _Tp> : public tuple_size<_Tp> {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size<volatile _Tp> : public tuple_size<_Tp> {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS tuple_size<const volatile _Tp> : public tuple_size<_Tp> {};
-#endif
-
-template <size_t _Ip, class _Tp> class _LIBCPP_TEMPLATE_VIS tuple_element;
-
-template <size_t _Ip, class _Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const _Tp>
-{
-public:
-    typedef typename add_const<typename tuple_element<_Ip, _Tp>::type>::type type;
-};
-
-template <size_t _Ip, class _Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, volatile _Tp>
-{
-public:
-    typedef typename add_volatile<typename tuple_element<_Ip, _Tp>::type>::type type;
-};
-
-template <size_t _Ip, class _Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const volatile _Tp>
-{
-public:
-    typedef typename add_cv<typename tuple_element<_Ip, _Tp>::type>::type type;
-};
-
-template <class _Tp> struct __tuple_like : false_type {};
-
-template <class _Tp> struct __tuple_like<const _Tp> : public __tuple_like<_Tp> {};
-template <class _Tp> struct __tuple_like<volatile _Tp> : public __tuple_like<_Tp> {};
-template <class _Tp> struct __tuple_like<const volatile _Tp> : public __tuple_like<_Tp> {};
-
-// tuple specializations
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <size_t...> struct __tuple_indices {};
-
-template <class _IdxType, _IdxType... _Values>
-struct __integer_sequence {
-  template <template <class _OIdxType, _OIdxType...> class _ToIndexSeq, class _ToIndexType>
-  using __convert = _ToIndexSeq<_ToIndexType, _Values...>;
-
-  template <size_t _Sp>
-  using __to_tuple_indices = __tuple_indices<(_Values + _Sp)...>;
-};
-
-#if !__has_builtin(__make_integer_seq) || defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
-namespace __detail {
-
-template<typename _Tp, size_t ..._Extra> struct __repeat;
-template<typename _Tp, _Tp ..._Np, size_t ..._Extra> struct __repeat<__integer_sequence<_Tp, _Np...>, _Extra...> {
-  typedef __integer_sequence<_Tp,
-                           _Np...,
-                           sizeof...(_Np) + _Np...,
-                           2 * sizeof...(_Np) + _Np...,
-                           3 * sizeof...(_Np) + _Np...,
-                           4 * sizeof...(_Np) + _Np...,
-                           5 * sizeof...(_Np) + _Np...,
-                           6 * sizeof...(_Np) + _Np...,
-                           7 * sizeof...(_Np) + _Np...,
-                           _Extra...> type;
-};
-
-template<size_t _Np> struct __parity;
-template<size_t _Np> struct __make : __parity<_Np % 8>::template __pmake<_Np> {};
-
-template<> struct __make<0> { typedef __integer_sequence<size_t> type; };
-template<> struct __make<1> { typedef __integer_sequence<size_t, 0> type; };
-template<> struct __make<2> { typedef __integer_sequence<size_t, 0, 1> type; };
-template<> struct __make<3> { typedef __integer_sequence<size_t, 0, 1, 2> type; };
-template<> struct __make<4> { typedef __integer_sequence<size_t, 0, 1, 2, 3> type; };
-template<> struct __make<5> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4> type; };
-template<> struct __make<6> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5> type; };
-template<> struct __make<7> { typedef __integer_sequence<size_t, 0, 1, 2, 3, 4, 5, 6> type; };
-
-template<> struct __parity<0> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type> {}; };
-template<> struct __parity<1> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 1> {}; };
-template<> struct __parity<2> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 2, _Np - 1> {}; };
-template<> struct __parity<3> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 3, _Np - 2, _Np - 1> {}; };
-template<> struct __parity<4> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
-template<> struct __parity<5> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
-template<> struct __parity<6> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 6, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
-template<> struct __parity<7> { template<size_t _Np> struct __pmake : __repeat<typename __make<_Np / 8>::type, _Np - 7, _Np - 6, _Np - 5, _Np - 4, _Np - 3, _Np - 2, _Np - 1> {}; };
-
-} // namespace detail
-
-#endif  // !__has_builtin(__make_integer_seq) || defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
-
-#if __has_builtin(__make_integer_seq)
-template <size_t _Ep, size_t _Sp>
-using __make_indices_imp =
-    typename __make_integer_seq<__integer_sequence, size_t, _Ep - _Sp>::template
-    __to_tuple_indices<_Sp>;
-#else
-template <size_t _Ep, size_t _Sp>
-using __make_indices_imp =
-    typename __detail::__make<_Ep - _Sp>::type::template __to_tuple_indices<_Sp>;
-
-#endif
-
-template <size_t _Ep, size_t _Sp = 0>
-struct __make_tuple_indices
-{
-    static_assert(_Sp <= _Ep, "__make_tuple_indices input error");
-    typedef __make_indices_imp<_Ep, _Sp> type;
-};
-
-
-template <class ..._Tp> class _LIBCPP_TEMPLATE_VIS tuple;
-
-template <class... _Tp> struct __tuple_like<tuple<_Tp...> > : true_type {};
-
-template <class ..._Tp>
-struct _LIBCPP_TEMPLATE_VIS tuple_size<tuple<_Tp...> >
-    : public integral_constant<size_t, sizeof...(_Tp)>
-{
-};
-
-template <size_t _Ip, class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename tuple_element<_Ip, tuple<_Tp...> >::type&
-get(tuple<_Tp...>&) _NOEXCEPT;
-
-template <size_t _Ip, class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const typename tuple_element<_Ip, tuple<_Tp...> >::type&
-get(const tuple<_Tp...>&) _NOEXCEPT;
-
-template <size_t _Ip, class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename tuple_element<_Ip, tuple<_Tp...> >::type&&
-get(tuple<_Tp...>&&) _NOEXCEPT;
-
-template <size_t _Ip, class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const typename tuple_element<_Ip, tuple<_Tp...> >::type&&
-get(const tuple<_Tp...>&&) _NOEXCEPT;
-
-#endif // !defined(_LIBCPP_CXX03_LANG)
-
-// pair specializations
-
-template <class _T1, class _T2> struct __tuple_like<pair<_T1, _T2> > : true_type {};
-
-template <size_t _Ip, class _T1, class _T2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename tuple_element<_Ip, pair<_T1, _T2> >::type&
-get(pair<_T1, _T2>&) _NOEXCEPT;
-
-template <size_t _Ip, class _T1, class _T2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
-get(const pair<_T1, _T2>&) _NOEXCEPT;
-
-#ifndef _LIBCPP_CXX03_LANG
-template <size_t _Ip, class _T1, class _T2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
-get(pair<_T1, _T2>&&) _NOEXCEPT;
-
-template <size_t _Ip, class _T1, class _T2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
-get(const pair<_T1, _T2>&&) _NOEXCEPT;
-#endif
-
-// array specializations
-
-template <class _Tp, size_t _Size> struct _LIBCPP_TEMPLATE_VIS array;
-
-template <class _Tp, size_t _Size> struct __tuple_like<array<_Tp, _Size> > : true_type {};
-
-template <size_t _Ip, class _Tp, size_t _Size>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp&
-get(array<_Tp, _Size>&) _NOEXCEPT;
-
-template <size_t _Ip, class _Tp, size_t _Size>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-get(const array<_Tp, _Size>&) _NOEXCEPT;
-
-#ifndef _LIBCPP_CXX03_LANG
-template <size_t _Ip, class _Tp, size_t _Size>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp&&
-get(array<_Tp, _Size>&&) _NOEXCEPT;
-
-template <size_t _Ip, class _Tp, size_t _Size>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&&
-get(const array<_Tp, _Size>&&) _NOEXCEPT;
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-
-// __tuple_types
-
-template <class ..._Tp> struct __tuple_types {};
-
-#if !__has_builtin(__type_pack_element)
-
-namespace __indexer_detail {
-
-template <size_t _Idx, class _Tp>
-struct __indexed { using type = _Tp; };
-
-template <class _Types, class _Indexes> struct __indexer;
-
-template <class ..._Types, size_t ..._Idx>
-struct __indexer<__tuple_types<_Types...>, __tuple_indices<_Idx...>>
-    : __indexed<_Idx, _Types>...
-{};
-
-template <size_t _Idx, class _Tp>
-__indexed<_Idx, _Tp> __at_index(__indexed<_Idx, _Tp> const&);
-
-} // namespace __indexer_detail
-
-template <size_t _Idx, class ..._Types>
-using __type_pack_element = typename decltype(
-    __indexer_detail::__at_index<_Idx>(
-        __indexer_detail::__indexer<
-            __tuple_types<_Types...>,
-            typename __make_tuple_indices<sizeof...(_Types)>::type
-        >{})
-  )::type;
-#endif
-
-template <size_t _Ip, class ..._Types>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, __tuple_types<_Types...>>
-{
-public:
-    static_assert(_Ip < sizeof...(_Types), "tuple_element index out of range");
-    typedef __type_pack_element<_Ip, _Types...> type;
-};
-
-
-template <class ..._Tp>
-struct _LIBCPP_TEMPLATE_VIS tuple_size<__tuple_types<_Tp...> >
-    : public integral_constant<size_t, sizeof...(_Tp)>
-{
-};
-
-template <class... _Tp> struct __tuple_like<__tuple_types<_Tp...> > : true_type {};
-
-template <bool _ApplyLV, bool _ApplyConst, bool _ApplyVolatile>
-struct __apply_cv_mf;
-template <>
-struct __apply_cv_mf<false, false, false> {
-  template <class _Tp> using __apply = _Tp;
-};
-template <>
-struct __apply_cv_mf<false, true, false> {
-  template <class _Tp> using __apply = const _Tp;
-};
-template <>
-struct __apply_cv_mf<false, false, true> {
-  template <class _Tp> using __apply = volatile _Tp;
-};
-template <>
-struct __apply_cv_mf<false, true, true> {
-  template <class _Tp> using __apply = const volatile _Tp;
-};
-template <>
-struct __apply_cv_mf<true, false, false> {
-  template <class _Tp> using __apply = _Tp&;
-};
-template <>
-struct __apply_cv_mf<true, true, false> {
-  template <class _Tp> using __apply = const _Tp&;
-};
-template <>
-struct __apply_cv_mf<true, false, true> {
-  template <class _Tp> using __apply = volatile _Tp&;
-};
-template <>
-struct __apply_cv_mf<true, true, true> {
-  template <class _Tp> using __apply = const volatile _Tp&;
-};
-template <class _Tp, class _RawTp = typename remove_reference<_Tp>::type>
-using __apply_cv_t = __apply_cv_mf<
-    is_lvalue_reference<_Tp>::value,
-    is_const<_RawTp>::value,
-    is_volatile<_RawTp>::value>;
-
-// __make_tuple_types
-
-// __make_tuple_types<_Tuple<_Types...>, _Ep, _Sp>::type is a
-// __tuple_types<_Types...> using only those _Types in the range [_Sp, _Ep).
-// _Sp defaults to 0 and _Ep defaults to tuple_size<_Tuple>.  If _Tuple is a
-// lvalue_reference type, then __tuple_types<_Types&...> is the result.
-
-template <class _TupleTypes, class _TupleIndices>
-struct __make_tuple_types_flat;
-
-template <template <class...> class _Tuple, class ..._Types, size_t ..._Idx>
-struct __make_tuple_types_flat<_Tuple<_Types...>, __tuple_indices<_Idx...>> {
-  // Specialization for pair, tuple, and __tuple_types
-  template <class _Tp, class _ApplyFn = __apply_cv_t<_Tp>>
-  using __apply_quals = __tuple_types<
-      typename _ApplyFn::template __apply<__type_pack_element<_Idx, _Types...>>...
-    >;
-};
-
-template <class _Vt, size_t _Np, size_t ..._Idx>
-struct __make_tuple_types_flat<array<_Vt, _Np>, __tuple_indices<_Idx...>> {
-  template <size_t>
-  using __value_type = _Vt;
-  template <class _Tp, class _ApplyFn = __apply_cv_t<_Tp>>
-  using __apply_quals = __tuple_types<
-      typename _ApplyFn::template __apply<__value_type<_Idx>>...
-    >;
-};
-
-template <class _Tp, size_t _Ep = tuple_size<typename remove_reference<_Tp>::type>::value,
-          size_t _Sp = 0,
-          bool _SameSize = (_Ep == tuple_size<typename remove_reference<_Tp>::type>::value)>
-struct __make_tuple_types
-{
-    static_assert(_Sp <= _Ep, "__make_tuple_types input error");
-    using _RawTp = typename remove_cv<typename remove_reference<_Tp>::type>::type;
-    using _Maker = __make_tuple_types_flat<_RawTp, typename __make_tuple_indices<_Ep, _Sp>::type>;
-    using type = typename _Maker::template __apply_quals<_Tp>;
-};
-
-template <class ..._Types, size_t _Ep>
-struct __make_tuple_types<tuple<_Types...>, _Ep, 0, true> {
-  typedef __tuple_types<_Types...> type;
-};
-
-template <class ..._Types, size_t _Ep>
-struct __make_tuple_types<__tuple_types<_Types...>, _Ep, 0, true> {
-  typedef __tuple_types<_Types...> type;
-};
-
-template <bool ..._Preds>
-struct __all_dummy;
-
-template <bool ..._Pred>
-using __all = is_same<__all_dummy<_Pred...>, __all_dummy<((void)_Pred, true)...>>;
-
-struct __tuple_sfinae_base {
-  template <template <class, class...> class _Trait,
-            class ..._LArgs, class ..._RArgs>
-  static auto __do_test(__tuple_types<_LArgs...>, __tuple_types<_RArgs...>)
-    -> __all<typename enable_if<_Trait<_LArgs, _RArgs>::value, bool>::type{true}...>;
-  template <template <class...> class>
-  static auto __do_test(...) -> false_type;
-
-  template <class _FromArgs, class _ToArgs>
-  using __constructible = decltype(__do_test<is_constructible>(_ToArgs{}, _FromArgs{}));
-  template <class _FromArgs, class _ToArgs>
-  using __convertible = decltype(__do_test<is_convertible>(_FromArgs{}, _ToArgs{}));
-  template <class _FromArgs, class _ToArgs>
-  using __assignable = decltype(__do_test<is_assignable>(_ToArgs{}, _FromArgs{}));
-};
-
-// __tuple_convertible
-
-template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
-                                bool = __tuple_like<_Up>::value>
-struct __tuple_convertible
-    : public false_type {};
-
-template <class _Tp, class _Up>
-struct __tuple_convertible<_Tp, _Up, true, true>
-    : public __tuple_sfinae_base::__convertible<
-      typename __make_tuple_types<_Tp>::type
-    , typename __make_tuple_types<_Up>::type
-    >
-{};
-
-// __tuple_constructible
-
-template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
-                                bool = __tuple_like<_Up>::value>
-struct __tuple_constructible
-    : public false_type {};
-
-template <class _Tp, class _Up>
-struct __tuple_constructible<_Tp, _Up, true, true>
-    : public __tuple_sfinae_base::__constructible<
-      typename __make_tuple_types<_Tp>::type
-    , typename __make_tuple_types<_Up>::type
-    >
-{};
-
-// __tuple_assignable
-
-template <class _Tp, class _Up, bool = __tuple_like<typename remove_reference<_Tp>::type>::value,
-                                bool = __tuple_like<_Up>::value>
-struct __tuple_assignable
-    : public false_type {};
-
-template <class _Tp, class _Up>
-struct __tuple_assignable<_Tp, _Up, true, true>
-    : public __tuple_sfinae_base::__assignable<
-      typename __make_tuple_types<_Tp>::type
-    , typename __make_tuple_types<_Up&>::type
-    >
-{};
-
-
-template <size_t _Ip, class ..._Tp>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, tuple<_Tp...> >
-{
-public:
-    typedef typename tuple_element<_Ip, __tuple_types<_Tp...> >::type type;
-};
-
-#if _LIBCPP_STD_VER > 11
-template <size_t _Ip, class ..._Tp>
-using tuple_element_t = typename tuple_element <_Ip, _Tp...>::type;
-#endif
-
-template <bool _IsTuple, class _SizeTrait, size_t _Expected>
-struct __tuple_like_with_size_imp : false_type {};
-
-template <class _SizeTrait, size_t _Expected>
-struct __tuple_like_with_size_imp<true, _SizeTrait, _Expected>
-    : integral_constant<bool, _SizeTrait::value == _Expected> {};
-
-template <class _Tuple, size_t _ExpectedSize,
-          class _RawTuple = typename __uncvref<_Tuple>::type>
-using __tuple_like_with_size = __tuple_like_with_size_imp<
-                                   __tuple_like<_RawTuple>::value,
-                                   tuple_size<_RawTuple>, _ExpectedSize
-                              >;
-
-struct _LIBCPP_TYPE_VIS __check_tuple_constructor_fail {
-    template <class ...>
-    static constexpr bool __enable_default() { return false; }
-    template <class ...>
-    static constexpr bool __enable_explicit() { return false; }
-    template <class ...>
-    static constexpr bool __enable_implicit() { return false; }
-    template <class ...>
-    static constexpr bool __enable_assign() { return false; }
-};
-#endif // !defined(_LIBCPP_CXX03_LANG)
-
-#if _LIBCPP_STD_VER > 14
-
-template <bool _CanCopy, bool _CanMove>
-struct __sfinae_ctor_base {};
-template <>
-struct __sfinae_ctor_base<false, false> {
-  __sfinae_ctor_base() = default;
-  __sfinae_ctor_base(__sfinae_ctor_base const&) = delete;
-  __sfinae_ctor_base(__sfinae_ctor_base &&) = delete;
-  __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default;
-  __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default;
-};
-template <>
-struct __sfinae_ctor_base<true, false> {
-  __sfinae_ctor_base() = default;
-  __sfinae_ctor_base(__sfinae_ctor_base const&) = default;
-  __sfinae_ctor_base(__sfinae_ctor_base &&) = delete;
-  __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default;
-  __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default;
-};
-template <>
-struct __sfinae_ctor_base<false, true> {
-  __sfinae_ctor_base() = default;
-  __sfinae_ctor_base(__sfinae_ctor_base const&) = delete;
-  __sfinae_ctor_base(__sfinae_ctor_base &&) = default;
-  __sfinae_ctor_base& operator=(__sfinae_ctor_base const&) = default;
-  __sfinae_ctor_base& operator=(__sfinae_ctor_base&&) = default;
-};
-
-template <bool _CanCopy, bool _CanMove>
-struct __sfinae_assign_base {};
-template <>
-struct __sfinae_assign_base<false, false> {
-  __sfinae_assign_base() = default;
-  __sfinae_assign_base(__sfinae_assign_base const&) = default;
-  __sfinae_assign_base(__sfinae_assign_base &&) = default;
-  __sfinae_assign_base& operator=(__sfinae_assign_base const&) = delete;
-  __sfinae_assign_base& operator=(__sfinae_assign_base&&) = delete;
-};
-template <>
-struct __sfinae_assign_base<true, false> {
-  __sfinae_assign_base() = default;
-  __sfinae_assign_base(__sfinae_assign_base const&) = default;
-  __sfinae_assign_base(__sfinae_assign_base &&) = default;
-  __sfinae_assign_base& operator=(__sfinae_assign_base const&) = default;
-  __sfinae_assign_base& operator=(__sfinae_assign_base&&) = delete;
-};
-template <>
-struct __sfinae_assign_base<false, true> {
-  __sfinae_assign_base() = default;
-  __sfinae_assign_base(__sfinae_assign_base const&) = default;
-  __sfinae_assign_base(__sfinae_assign_base &&) = default;
-  __sfinae_assign_base& operator=(__sfinae_assign_base const&) = delete;
-  __sfinae_assign_base& operator=(__sfinae_assign_base&&) = default;
-};
-#endif // _LIBCPP_STD_VER > 14
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP___TUPLE
diff --git a/lib/libcxx/include/__undef_macros b/lib/libcxx/include/__undef_macros
deleted file mode 100644
index 60ab1dbfb5f..00000000000
--- a/lib/libcxx/include/__undef_macros
+++ /dev/null
@@ -1,34 +0,0 @@
-// -*- C++ -*-
-//===------------------------ __undef_macros ------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-
-#ifdef min
-#if !defined(_LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS)
-#if defined(_LIBCPP_WARNING)
-_LIBCPP_WARNING("macro min is incompatible with C++.  Try #define NOMINMAX "
-                "before any Windows header. #undefing min")
-#else
-#warning: macro min is incompatible with C++.  #undefing min
-#endif
-#endif
-#undef min
-#endif
-
-#ifdef max
-#if !defined(_LIBCPP_DISABLE_MACRO_CONFLICT_WARNINGS)
-#if defined(_LIBCPP_WARNING)
-_LIBCPP_WARNING("macro max is incompatible with C++.  Try #define NOMINMAX "
-                "before any Windows header. #undefing max")
-#else
-#warning: macro max is incompatible with C++.  #undefing max
-#endif
-#endif
-#undef max
-#endif
diff --git a/lib/libcxx/include/algorithm b/lib/libcxx/include/algorithm
deleted file mode 100644
index d102899f2df..00000000000
--- a/lib/libcxx/include/algorithm
+++ /dev/null
@@ -1,5710 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- algorithm ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_ALGORITHM
-#define _LIBCPP_ALGORITHM
-
-/*
-    algorithm synopsis
-
-#include <initializer_list>
-
-namespace std
-{
-
-template <class InputIterator, class Predicate>
-    constexpr bool     // constexpr in C++20
-    all_of(InputIterator first, InputIterator last, Predicate pred);
-
-template <class InputIterator, class Predicate>
-    constexpr bool     // constexpr in C++20
-    any_of(InputIterator first, InputIterator last, Predicate pred);
-
-template <class InputIterator, class Predicate>
-    constexpr bool     // constexpr in C++20
-    none_of(InputIterator first, InputIterator last, Predicate pred);
-
-template <class InputIterator, class Function>
-    constexpr Function          // constexpr in C++20
-    for_each(InputIterator first, InputIterator last, Function f);
-
-template<class InputIterator, class Size, class Function>
-    constexpr InputIterator     // constexpr in C++20
-    for_each_n(InputIterator first, Size n, Function f); // C++17
-
-template <class InputIterator, class T>
-    constexpr InputIterator     // constexpr in C++20
-    find(InputIterator first, InputIterator last, const T& value);
-
-template <class InputIterator, class Predicate>
-    constexpr InputIterator     // constexpr in C++20
-    find_if(InputIterator first, InputIterator last, Predicate pred);
-
-template<class InputIterator, class Predicate>
-    InputIterator               // constexpr in C++20
-    find_if_not(InputIterator first, InputIterator last, Predicate pred);
-
-template <class ForwardIterator1, class ForwardIterator2>
-    ForwardIterator1            // constexpr in C++20
-    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
-             ForwardIterator2 first2, ForwardIterator2 last2);
-
-template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    ForwardIterator1            // constexpr in C++20
-    find_end(ForwardIterator1 first1, ForwardIterator1 last1,
-             ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
-
-template <class ForwardIterator1, class ForwardIterator2>
-    constexpr ForwardIterator1  // constexpr in C++20
-    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
-                  ForwardIterator2 first2, ForwardIterator2 last2);
-
-template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    constexpr ForwardIterator1  // constexpr in C++20
-    find_first_of(ForwardIterator1 first1, ForwardIterator1 last1,
-                  ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
-
-template <class ForwardIterator>
-    constexpr ForwardIterator   // constexpr in C++20
-    adjacent_find(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class BinaryPredicate>
-    constexpr ForwardIterator   // constexpr in C++20
-    adjacent_find(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
-
-template <class InputIterator, class T>
-    constexpr typename iterator_traits<InputIterator>::difference_type  // constexpr in C++20
-    count(InputIterator first, InputIterator last, const T& value);
-
-template <class InputIterator, class Predicate>
-    constexpr typename iterator_traits<InputIterator>::difference_type // constexpr in C++20
-    count_if(InputIterator first, InputIterator last, Predicate pred);
-
-template <class InputIterator1, class InputIterator2>
-    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
-    mismatch(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
-
-template <class InputIterator1, class InputIterator2>
-    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
-    mismatch(InputIterator1 first1, InputIterator1 last1,
-             InputIterator2 first2, InputIterator2 last2); // **C++14**
-
-template <class InputIterator1, class InputIterator2, class BinaryPredicate>
-    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
-    mismatch(InputIterator1 first1, InputIterator1 last1,
-             InputIterator2 first2, BinaryPredicate pred);
-
-template <class InputIterator1, class InputIterator2, class BinaryPredicate>
-    constexpr pair<InputIterator1, InputIterator2>   // constexpr in C++20
-    mismatch(InputIterator1 first1, InputIterator1 last1,
-             InputIterator2 first2, InputIterator2 last2,
-             BinaryPredicate pred); // **C++14**
-
-template <class InputIterator1, class InputIterator2>
-    constexpr bool      // constexpr in C++20
-    equal(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2);
-
-template <class InputIterator1, class InputIterator2>
-    constexpr bool      // constexpr in C++20
-    equal(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, InputIterator2 last2); // **C++14**
-
-template <class InputIterator1, class InputIterator2, class BinaryPredicate>
-    constexpr bool      // constexpr in C++20
-    equal(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, BinaryPredicate pred);
-
-template <class InputIterator1, class InputIterator2, class BinaryPredicate>
-    constexpr bool      // constexpr in C++20
-    equal(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, InputIterator2 last2,
-          BinaryPredicate pred); // **C++14**
-
-template<class ForwardIterator1, class ForwardIterator2>
-    constexpr bool      // constexpr in C++20
-    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
-                   ForwardIterator2 first2);
-
-template<class ForwardIterator1, class ForwardIterator2>
-    constexpr bool      // constexpr in C++20
-    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
-                   ForwardIterator2 first2, ForwardIterator2 last2); // **C++14**
-
-template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    constexpr bool      // constexpr in C++20
-    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
-                   ForwardIterator2 first2, BinaryPredicate pred);
-
-template<class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    constexpr bool      // constexpr in C++20
-    is_permutation(ForwardIterator1 first1, ForwardIterator1 last1,
-                   ForwardIterator2 first2, ForwardIterator2 last2,
-                   BinaryPredicate pred);  // **C++14**
-
-template <class ForwardIterator1, class ForwardIterator2>
-    constexpr ForwardIterator1      // constexpr in C++20
-    search(ForwardIterator1 first1, ForwardIterator1 last1,
-           ForwardIterator2 first2, ForwardIterator2 last2);
-
-template <class ForwardIterator1, class ForwardIterator2, class BinaryPredicate>
-    constexpr ForwardIterator1      // constexpr in C++20
-    search(ForwardIterator1 first1, ForwardIterator1 last1,
-           ForwardIterator2 first2, ForwardIterator2 last2, BinaryPredicate pred);
-
-template <class ForwardIterator, class Size, class T>
-    constexpr ForwardIterator       // constexpr in C++20
-    search_n(ForwardIterator first, ForwardIterator last, Size count, const T& value);
-
-template <class ForwardIterator, class Size, class T, class BinaryPredicate>
-    constexpr ForwardIterator       // constexpr in C++20
-    search_n(ForwardIterator first, ForwardIterator last,
-             Size count, const T& value, BinaryPredicate pred);
-
-template <class InputIterator, class OutputIterator>
-    OutputIterator
-    copy(InputIterator first, InputIterator last, OutputIterator result);
-
-template<class InputIterator, class OutputIterator, class Predicate>
-    OutputIterator
-    copy_if(InputIterator first, InputIterator last,
-            OutputIterator result, Predicate pred);
-
-template<class InputIterator, class Size, class OutputIterator>
-    OutputIterator
-    copy_n(InputIterator first, Size n, OutputIterator result);
-
-template <class BidirectionalIterator1, class BidirectionalIterator2>
-    BidirectionalIterator2
-    copy_backward(BidirectionalIterator1 first, BidirectionalIterator1 last,
-                  BidirectionalIterator2 result);
-
-template <class ForwardIterator1, class ForwardIterator2>
-    ForwardIterator2
-    swap_ranges(ForwardIterator1 first1, ForwardIterator1 last1, ForwardIterator2 first2);
-
-template <class ForwardIterator1, class ForwardIterator2>
-    void
-    iter_swap(ForwardIterator1 a, ForwardIterator2 b);
-
-template <class InputIterator, class OutputIterator, class UnaryOperation>
-    constexpr OutputIterator      // constexpr in C++20
-    transform(InputIterator first, InputIterator last, OutputIterator result, UnaryOperation op);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class BinaryOperation>
-    constexpr OutputIterator      // constexpr in C++20
-    transform(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
-              OutputIterator result, BinaryOperation binary_op);
-
-template <class ForwardIterator, class T>
-    constexpr void      // constexpr in C++20
-    replace(ForwardIterator first, ForwardIterator last, const T& old_value, const T& new_value);
-
-template <class ForwardIterator, class Predicate, class T>
-    constexpr void      // constexpr in C++20
-    replace_if(ForwardIterator first, ForwardIterator last, Predicate pred, const T& new_value);
-
-template <class InputIterator, class OutputIterator, class T>
-    constexpr OutputIterator      // constexpr in C++20
-    replace_copy(InputIterator first, InputIterator last, OutputIterator result,
-                 const T& old_value, const T& new_value);
-
-template <class InputIterator, class OutputIterator, class Predicate, class T>
-    constexpr OutputIterator      // constexpr in C++20
-    replace_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred, const T& new_value);
-
-template <class ForwardIterator, class T>
-    constexpr void      // constexpr in C++20
-    fill(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class OutputIterator, class Size, class T>
-    constexpr OutputIterator      // constexpr in C++20
-    fill_n(OutputIterator first, Size n, const T& value);
-
-template <class ForwardIterator, class Generator>
-    constexpr void      // constexpr in C++20
-    generate(ForwardIterator first, ForwardIterator last, Generator gen);
-
-template <class OutputIterator, class Size, class Generator>
-    constexpr OutputIterator      // constexpr in C++20
-    generate_n(OutputIterator first, Size n, Generator gen);
-
-template <class ForwardIterator, class T>
-    constexpr ForwardIterator     // constexpr in C++20
-    remove(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class Predicate>
-    constexpr ForwardIterator     // constexpr in C++20
-    remove_if(ForwardIterator first, ForwardIterator last, Predicate pred);
-
-template <class InputIterator, class OutputIterator, class T>
-    constexpr OutputIterator     // constexpr in C++20
-    remove_copy(InputIterator first, InputIterator last, OutputIterator result, const T& value);
-
-template <class InputIterator, class OutputIterator, class Predicate>
-    constexpr OutputIterator     // constexpr in C++20
-    remove_copy_if(InputIterator first, InputIterator last, OutputIterator result, Predicate pred);
-
-template <class ForwardIterator>
-    ForwardIterator
-    unique(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class BinaryPredicate>
-    ForwardIterator
-    unique(ForwardIterator first, ForwardIterator last, BinaryPredicate pred);
-
-template <class InputIterator, class OutputIterator>
-    OutputIterator
-    unique_copy(InputIterator first, InputIterator last, OutputIterator result);
-
-template <class InputIterator, class OutputIterator, class BinaryPredicate>
-    OutputIterator
-    unique_copy(InputIterator first, InputIterator last, OutputIterator result, BinaryPredicate pred);
-
-template <class BidirectionalIterator>
-    void
-    reverse(BidirectionalIterator first, BidirectionalIterator last);
-
-template <class BidirectionalIterator, class OutputIterator>
-    constexpr OutputIterator       // constexpr in C++20
-    reverse_copy(BidirectionalIterator first, BidirectionalIterator last, OutputIterator result);
-
-template <class ForwardIterator>
-    ForwardIterator
-    rotate(ForwardIterator first, ForwardIterator middle, ForwardIterator last);
-
-template <class ForwardIterator, class OutputIterator>
-    OutputIterator
-    rotate_copy(ForwardIterator first, ForwardIterator middle, ForwardIterator last, OutputIterator result);
-
-template <class RandomAccessIterator>
-    void
-    random_shuffle(RandomAccessIterator first, RandomAccessIterator last); // deprecated in C++14, removed in C++17
-
-template <class RandomAccessIterator, class RandomNumberGenerator>
-    void
-    random_shuffle(RandomAccessIterator first, RandomAccessIterator last,
-                   RandomNumberGenerator& rand);  // deprecated in C++14, removed in C++17
-
-template<class PopulationIterator, class SampleIterator,
-         class Distance, class UniformRandomBitGenerator>
-    SampleIterator sample(PopulationIterator first, PopulationIterator last,
-                          SampleIterator out, Distance n,
-                          UniformRandomBitGenerator&& g); // C++17
-
-template<class RandomAccessIterator, class UniformRandomNumberGenerator>
-    void shuffle(RandomAccessIterator first, RandomAccessIterator last,
-                 UniformRandomNumberGenerator&& g);
-
-template <class InputIterator, class Predicate>
-    constexpr bool  // constexpr in C++20
-    is_partitioned(InputIterator first, InputIterator last, Predicate pred);
-
-template <class ForwardIterator, class Predicate>
-    ForwardIterator
-    partition(ForwardIterator first, ForwardIterator last, Predicate pred);
-
-template <class InputIterator, class OutputIterator1,
-          class OutputIterator2, class Predicate>
-    constexpr pair<OutputIterator1, OutputIterator2>   // constexpr in C++20
-    partition_copy(InputIterator first, InputIterator last,
-                   OutputIterator1 out_true, OutputIterator2 out_false,
-                   Predicate pred);
-
-template <class ForwardIterator, class Predicate>
-    ForwardIterator
-    stable_partition(ForwardIterator first, ForwardIterator last, Predicate pred);
-
-template<class ForwardIterator, class Predicate>
-    constexpr ForwardIterator  // constexpr in C++20
-    partition_point(ForwardIterator first, ForwardIterator last, Predicate pred);
-
-template <class ForwardIterator>
-    constexpr bool  // constexpr in C++20
-    is_sorted(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class Compare>
-    bool
-    is_sorted(ForwardIterator first, ForwardIterator last, Compare comp);
-
-template<class ForwardIterator>
-    constexpr ForwardIterator    // constexpr in C++20
-    is_sorted_until(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class Compare>
-    constexpr ForwardIterator    // constexpr in C++20
-    is_sorted_until(ForwardIterator first, ForwardIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    sort(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    stable_sort(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    stable_sort(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    partial_sort(RandomAccessIterator first, RandomAccessIterator middle, RandomAccessIterator last, Compare comp);
-
-template <class InputIterator, class RandomAccessIterator>
-    RandomAccessIterator
-    partial_sort_copy(InputIterator first, InputIterator last,
-                      RandomAccessIterator result_first, RandomAccessIterator result_last);
-
-template <class InputIterator, class RandomAccessIterator, class Compare>
-    RandomAccessIterator
-    partial_sort_copy(InputIterator first, InputIterator last,
-                      RandomAccessIterator result_first, RandomAccessIterator result_last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    nth_element(RandomAccessIterator first, RandomAccessIterator nth, RandomAccessIterator last, Compare comp);
-
-template <class ForwardIterator, class T>
-    constexpr ForwardIterator                         // constexpr in C++20
-    lower_bound(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class T, class Compare>
-    constexpr ForwardIterator                         // constexpr in C++20
-    lower_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
-
-template <class ForwardIterator, class T>
-    constexpr ForwardIterator                         // constexpr in C++20
-    upper_bound(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class T, class Compare>
-    constexpr ForwardIterator                         // constexpr in C++20
-    upper_bound(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
-
-template <class ForwardIterator, class T>
-    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
-    equal_range(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class T, class Compare>
-    constexpr pair<ForwardIterator, ForwardIterator>  // constexpr in C++20
-    equal_range(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
-
-template <class ForwardIterator, class T>
-    constexpr bool                                    // constexpr in C++20
-    binary_search(ForwardIterator first, ForwardIterator last, const T& value);
-
-template <class ForwardIterator, class T, class Compare>
-    constexpr bool                                    // constexpr in C++20
-    binary_search(ForwardIterator first, ForwardIterator last, const T& value, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    OutputIterator
-    merge(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    OutputIterator
-    merge(InputIterator1 first1, InputIterator1 last1,
-          InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class BidirectionalIterator>
-    void
-    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last);
-
-template <class BidirectionalIterator, class Compare>
-    void
-    inplace_merge(BidirectionalIterator first, BidirectionalIterator middle, BidirectionalIterator last, Compare comp);
-
-template <class InputIterator1, class InputIterator2>
-    constexpr bool                                    // constexpr in C++20
-    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
-
-template <class InputIterator1, class InputIterator2, class Compare>
-    constexpr bool                                    // constexpr in C++20
-    includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    OutputIterator
-    set_union(InputIterator1 first1, InputIterator1 last1,
-              InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    OutputIterator
-    set_union(InputIterator1 first1, InputIterator1 last1,
-              InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    constexpr OutputIterator                         // constexpr in C++20
-    set_intersection(InputIterator1 first1, InputIterator1 last1,
-                     InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    constexpr OutputIterator                         // constexpr in C++20
-    set_intersection(InputIterator1 first1, InputIterator1 last1,
-                     InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    OutputIterator
-    set_difference(InputIterator1 first1, InputIterator1 last1,
-                   InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    OutputIterator
-    set_difference(InputIterator1 first1, InputIterator1 last1,
-                   InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator>
-    OutputIterator
-    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
-                             InputIterator2 first2, InputIterator2 last2, OutputIterator result);
-
-template <class InputIterator1, class InputIterator2, class OutputIterator, class Compare>
-    OutputIterator
-    set_symmetric_difference(InputIterator1 first1, InputIterator1 last1,
-                             InputIterator2 first2, InputIterator2 last2, OutputIterator result, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    push_heap(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    push_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    pop_heap(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    pop_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    make_heap(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    make_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    void
-    sort_heap(RandomAccessIterator first, RandomAccessIterator last);
-
-template <class RandomAccessIterator, class Compare>
-    void
-    sort_heap(RandomAccessIterator first, RandomAccessIterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    constexpr bool   // constexpr in C++20
-    is_heap(RandomAccessIterator first, RandomAccessiterator last);
-
-template <class RandomAccessIterator, class Compare>
-    constexpr bool   // constexpr in C++20
-    is_heap(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
-
-template <class RandomAccessIterator>
-    constexpr RandomAccessIterator   // constexpr in C++20
-    is_heap_until(RandomAccessIterator first, RandomAccessiterator last);
-
-template <class RandomAccessIterator, class Compare>
-    constexpr RandomAccessIterator   // constexpr in C++20
-    is_heap_until(RandomAccessIterator first, RandomAccessiterator last, Compare comp);
-
-template <class ForwardIterator>
-    ForwardIterator
-    min_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
-
-template <class ForwardIterator, class Compare>
-    ForwardIterator
-    min_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
-
-template <class T>
-    const T&
-    min(const T& a, const T& b);  // constexpr in C++14
-
-template <class T, class Compare>
-    const T&
-    min(const T& a, const T& b, Compare comp);  // constexpr in C++14
-
-template<class T>
-    T
-    min(initializer_list<T> t);  // constexpr in C++14
-
-template<class T, class Compare>
-    T
-    min(initializer_list<T> t, Compare comp);  // constexpr in C++14
-
-template<class T>
-    constexpr const T& clamp( const T& v, const T& lo, const T& hi );               // C++17
-
-template<class T, class Compare>
-    constexpr const T& clamp( const T& v, const T& lo, const T& hi, Compare comp ); // C++17
-
-template <class ForwardIterator>
-    ForwardIterator
-    max_element(ForwardIterator first, ForwardIterator last);  // constexpr in C++14
-
-template <class ForwardIterator, class Compare>
-    ForwardIterator
-    max_element(ForwardIterator first, ForwardIterator last, Compare comp);  // constexpr in C++14
-
-template <class T>
-    const T&
-    max(const T& a, const T& b); // constexpr in C++14
-
-template <class T, class Compare>
-    const T&
-    max(const T& a, const T& b, Compare comp);  // constexpr in C++14
-
-template<class T>
-    T
-    max(initializer_list<T> t);  // constexpr in C++14
-
-template<class T, class Compare>
-    T
-    max(initializer_list<T> t, Compare comp);  // constexpr in C++14
-
-template<class ForwardIterator>
-    pair<ForwardIterator, ForwardIterator>
-    minmax_element(ForwardIterator first, ForwardIterator last);   // constexpr in C++14
-
-template<class ForwardIterator, class Compare>
-    pair<ForwardIterator, ForwardIterator>
-    minmax_element(ForwardIterator first, ForwardIterator last, Compare comp);   // constexpr in C++14
-
-template<class T>
-    pair<const T&, const T&>
-    minmax(const T& a, const T& b);  // constexpr in C++14
-
-template<class T, class Compare>
-    pair<const T&, const T&>
-    minmax(const T& a, const T& b, Compare comp);  // constexpr in C++14
-
-template<class T>
-    pair<T, T>
-    minmax(initializer_list<T> t);  // constexpr in C++14
-
-template<class T, class Compare>
-    pair<T, T>
-    minmax(initializer_list<T> t, Compare comp);  // constexpr in C++14
-
-template <class InputIterator1, class InputIterator2>
-    constexpr bool     // constexpr in C++20
-    lexicographical_compare(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2);
-
-template <class InputIterator1, class InputIterator2, class Compare>
-    constexpr bool     // constexpr in C++20
-    lexicographical_compare(InputIterator1 first1, InputIterator1 last1,
-                            InputIterator2 first2, InputIterator2 last2, Compare comp);
-
-template <class BidirectionalIterator>
-    bool
-    next_permutation(BidirectionalIterator first, BidirectionalIterator last);
-
-template <class BidirectionalIterator, class Compare>
-    bool
-    next_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
-
-template <class BidirectionalIterator>
-    bool
-    prev_permutation(BidirectionalIterator first, BidirectionalIterator last);
-
-template <class BidirectionalIterator, class Compare>
-    bool
-    prev_permutation(BidirectionalIterator first, BidirectionalIterator last, Compare comp);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <initializer_list>
-#include <type_traits>
-#include <cstring>
-#include <utility> // needed to provide swap_ranges.
-#include <memory>
-#include <functional>
-#include <iterator>
-#include <cstddef>
-#include <bit>
-#include <version>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// I'd like to replace these with _VSTD::equal_to<void>, but can't because:
-//   * That only works with C++14 and later, and
-//   * We haven't included <functional> here.
-template <class _T1, class _T2 = _T1>
-struct __equal_to
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T1& __x, const _T2& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T1& __y) const {return __x == __y;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 bool operator()(const _T2& __x, const _T2& __y) const {return __x == __y;}
-};
-
-template <class _T1>
-struct __equal_to<_T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-};
-
-template <class _T1>
-struct __equal_to<const _T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-};
-
-template <class _T1>
-struct __equal_to<_T1, const _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x == __y;}
-};
-
-template <class _T1, class _T2 = _T1>
-struct __less
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T2& __y) const {return __x < __y;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T2& __x, const _T1& __y) const {return __x < __y;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T2& __x, const _T2& __y) const {return __x < __y;}
-};
-
-template <class _T1>
-struct __less<_T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-};
-
-template <class _T1>
-struct __less<const _T1, _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-};
-
-template <class _T1>
-struct __less<_T1, const _T1>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _T1& __x, const _T1& __y) const {return __x < __y;}
-};
-
-template <class _Predicate>
-class __invert // invert the sense of a comparison
-{
-private:
-    _Predicate __p_;
-public:
-    _LIBCPP_INLINE_VISIBILITY __invert() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __invert(_Predicate __p) : __p_(__p) {}
-
-    template <class _T1>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _T1& __x) {return !__p_(__x);}
-
-    template <class _T1, class _T2>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _T1& __x, const _T2& __y) {return __p_(__y, __x);}
-};
-
-// Perform division by two quickly for positive integers (llvm.org/PR39129)
-
-template <typename _Integral>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    is_integral<_Integral>::value,
-    _Integral
->::type
-__half_positive(_Integral __value)
-{
-    return static_cast<_Integral>(static_cast<typename make_unsigned<_Integral>::type>(__value) / 2);
-}
-
-template <typename _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    !is_integral<_Tp>::value,
-    _Tp
->::type
-__half_positive(_Tp __value)
-{
-    return __value / 2;
-}
-
-#ifdef _LIBCPP_DEBUG
-
-template <class _Compare>
-struct __debug_less
-{
-    _Compare __comp_;
-    __debug_less(_Compare& __c) : __comp_(__c) {}
-
-    template <class _Tp, class _Up>
-    bool operator()(const _Tp& __x, const _Up& __y)
-    {
-        bool __r = __comp_(__x, __y);
-        if (__r)
-            __do_compare_assert(0, __y, __x);
-        return __r;
-    }
-
-    template <class _LHS, class _RHS>
-    inline _LIBCPP_INLINE_VISIBILITY
-    decltype((void)_VSTD::declval<_Compare&>()(
-        _VSTD::declval<_LHS const&>(), _VSTD::declval<_RHS const&>()))
-    __do_compare_assert(int, _LHS const& __l, _RHS const& __r) {
-        _LIBCPP_ASSERT(!__comp_(__l, __r),
-            "Comparator does not induce a strict weak ordering");
-    }
-
-    template <class _LHS, class _RHS>
-    inline _LIBCPP_INLINE_VISIBILITY
-    void __do_compare_assert(long, _LHS const&, _RHS const&) {}
-};
-
-#endif  // _LIBCPP_DEBUG
-
-// all_of
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-all_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (!__pred(*__first))
-            return false;
-    return true;
-}
-
-// any_of
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-any_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            return true;
-    return false;
-}
-
-// none_of
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-none_of(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            return false;
-    return true;
-}
-
-// for_each
-
-template <class _InputIterator, class _Function>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_Function
-for_each(_InputIterator __first, _InputIterator __last, _Function __f)
-{
-    for (; __first != __last; ++__first)
-        __f(*__first);
-    return __f;
-}
-
-#if _LIBCPP_STD_VER > 14
-// for_each_n
-
-template <class _InputIterator, class _Size, class _Function>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-for_each_n(_InputIterator __first, _Size __orig_n, _Function __f)
-{
-    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
-    _IntegralSize __n = __orig_n;
-    while (__n > 0)
-    {
-         __f(*__first);
-         ++__first;
-         --__n;
-    }
-    return __first;
-}
-#endif
-
-// find
-
-template <class _InputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-find(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
-{
-    for (; __first != __last; ++__first)
-        if (*__first == __value_)
-            break;
-    return __first;
-}
-
-// find_if
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-find_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            break;
-    return __first;
-}
-
-// find_if_not
-
-template<class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_InputIterator
-find_if_not(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (!__pred(*__first))
-            break;
-    return __first;
-}
-
-// find_end
-
-template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator1
-__find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-           _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
-           forward_iterator_tag, forward_iterator_tag)
-{
-    // modeled after search algorithm
-    _ForwardIterator1 __r = __last1;  // __last1 is the "default" answer
-    if (__first2 == __last2)
-        return __r;
-    while (true)
-    {
-        while (true)
-        {
-            if (__first1 == __last1)         // if source exhausted return last correct answer
-                return __r;                  //    (or __last1 if never found)
-            if (__pred(*__first1, *__first2))
-                break;
-            ++__first1;
-        }
-        // *__first1 matches *__first2, now match elements after here
-        _ForwardIterator1 __m1 = __first1;
-        _ForwardIterator2 __m2 = __first2;
-        while (true)
-        {
-            if (++__m2 == __last2)
-            {                         // Pattern exhaused, record answer and search for another one
-                __r = __first1;
-                ++__first1;
-                break;
-            }
-            if (++__m1 == __last1)     // Source exhausted, return last answer
-                return __r;
-            if (!__pred(*__m1, *__m2))  // mismatch, restart with a new __first
-            {
-                ++__first1;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _BidirectionalIterator1, class _BidirectionalIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _BidirectionalIterator1
-__find_end(_BidirectionalIterator1 __first1, _BidirectionalIterator1 __last1,
-           _BidirectionalIterator2 __first2, _BidirectionalIterator2 __last2, _BinaryPredicate __pred,
-           bidirectional_iterator_tag, bidirectional_iterator_tag)
-{
-    // modeled after search algorithm (in reverse)
-    if (__first2 == __last2)
-        return __last1;  // Everything matches an empty sequence
-    _BidirectionalIterator1 __l1 = __last1;
-    _BidirectionalIterator2 __l2 = __last2;
-    --__l2;
-    while (true)
-    {
-        // Find last element in sequence 1 that matchs *(__last2-1), with a mininum of loop checks
-        while (true)
-        {
-            if (__first1 == __l1)  // return __last1 if no element matches *__first2
-                return __last1;
-            if (__pred(*--__l1, *__l2))
-                break;
-        }
-        // *__l1 matches *__l2, now match elements before here
-        _BidirectionalIterator1 __m1 = __l1;
-        _BidirectionalIterator2 __m2 = __l2;
-        while (true)
-        {
-            if (__m2 == __first2)  // If pattern exhausted, __m1 is the answer (works for 1 element pattern)
-                return __m1;
-            if (__m1 == __first1)  // Otherwise if source exhaused, pattern not found
-                return __last1;
-            if (!__pred(*--__m1, *--__m2))  // if there is a mismatch, restart with a new __l1
-            {
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _RandomAccessIterator1
-__find_end(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
-           _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
-           random_access_iterator_tag, random_access_iterator_tag)
-{
-    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
-    typename iterator_traits<_RandomAccessIterator2>::difference_type __len2 = __last2 - __first2;
-    if (__len2 == 0)
-        return __last1;
-    typename iterator_traits<_RandomAccessIterator1>::difference_type __len1 = __last1 - __first1;
-    if (__len1 < __len2)
-        return __last1;
-    const _RandomAccessIterator1 __s = __first1 + (__len2 - 1);  // End of pattern match can't go before here
-    _RandomAccessIterator1 __l1 = __last1;
-    _RandomAccessIterator2 __l2 = __last2;
-    --__l2;
-    while (true)
-    {
-        while (true)
-        {
-            if (__s == __l1)
-                return __last1;
-            if (__pred(*--__l1, *__l2))
-                break;
-        }
-        _RandomAccessIterator1 __m1 = __l1;
-        _RandomAccessIterator2 __m2 = __l2;
-        while (true)
-        {
-            if (__m2 == __first2)
-                return __m1;
-                                 // no need to check range on __m1 because __s guarantees we have enough source
-            if (!__pred(*--__m1, *--__m2))
-            {
-                break;
-            }
-        }
-    }
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    return _VSTD::__find_end<typename add_lvalue_reference<_BinaryPredicate>::type>
-                         (__first1, __last1, __first2, __last2, __pred,
-                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
-                          typename iterator_traits<_ForwardIterator2>::iterator_category());
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_end(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-         _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::find_end(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-
-// find_first_of
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _ForwardIterator1
-__find_first_of_ce(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1; ++__first1)
-        for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
-            if (__pred(*__first1, *__j))
-                return __first1;
-    return __last1;
-}
-
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY  _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-              _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __pred);
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY  _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-find_first_of(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-              _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::__find_first_of_ce(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-
-// adjacent_find
-
-template <class _ForwardIterator, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-adjacent_find(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (__pred(*__first, *__i))
-                return __first;
-            __first = __i;
-        }
-    }
-    return __last;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-adjacent_find(_ForwardIterator __first, _ForwardIterator __last)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
-    return _VSTD::adjacent_find(__first, __last, __equal_to<__v>());
-}
-
-// count
-
-template <class _InputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-typename iterator_traits<_InputIterator>::difference_type
-count(_InputIterator __first, _InputIterator __last, const _Tp& __value_)
-{
-    typename iterator_traits<_InputIterator>::difference_type __r(0);
-    for (; __first != __last; ++__first)
-        if (*__first == __value_)
-            ++__r;
-    return __r;
-}
-
-// count_if
-
-template <class _InputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-typename iterator_traits<_InputIterator>::difference_type
-count_if(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    typename iterator_traits<_InputIterator>::difference_type __r(0);
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            ++__r;
-    return __r;
-}
-
-// mismatch
-
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
-         _InputIterator2 __first2, _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::mismatch(__first1, __last1, __first2, __equal_to<__v1, __v2>());
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
-         _InputIterator2 __first2, _InputIterator2 __last2,
-         _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    return pair<_InputIterator1, _InputIterator2>(__first1, __first2);
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_InputIterator1, _InputIterator2>
-mismatch(_InputIterator1 __first1, _InputIterator1 __last1,
-         _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::mismatch(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-#endif
-
-// equal
-
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _BinaryPredicate __pred)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            return false;
-    return true;
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _BinaryPredicate, class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-__equal(_InputIterator1 __first1, _InputIterator1 __last1,
-        _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred,
-        input_iterator_tag, input_iterator_tag )
-{
-    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            return false;
-    return __first1 == __last1 && __first2 == __last2;
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-__equal(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
-        _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
-      random_access_iterator_tag, random_access_iterator_tag )
-{
-    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
-        return false;
-    return _VSTD::equal<_RandomAccessIterator1, _RandomAccessIterator2,
-                        typename add_lvalue_reference<_BinaryPredicate>::type>
-                       (__first1, __last1, __first2, __pred );
-}
-
-template <class _InputIterator1, class _InputIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2, _BinaryPredicate __pred )
-{
-    return _VSTD::__equal<typename add_lvalue_reference<_BinaryPredicate>::type>
-       (__first1, __last1, __first2, __last2, __pred,
-        typename iterator_traits<_InputIterator1>::iterator_category(),
-        typename iterator_traits<_InputIterator2>::iterator_category());
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-equal(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
-        typename iterator_traits<_InputIterator1>::iterator_category(),
-        typename iterator_traits<_InputIterator2>::iterator_category());
-}
-#endif
-
-// is_permutation
-
-template<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2, _BinaryPredicate __pred)
-{
-//  shorten sequences as much as possible by lopping of any equal prefix
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    if (__first1 == __last1)
-        return true;
-
-//  __first1 != __last1 && *__first1 != *__first2
-    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
-    _D1 __l1 = _VSTD::distance(__first1, __last1);
-    if (__l1 == _D1(1))
-        return false;
-    _ForwardIterator2 __last2 = _VSTD::next(__first2, __l1);
-    // For each element in [f1, l1) see if there are the same number of
-    //    equal elements in [f2, l2)
-    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
-    {
-    //  Have we already counted the number of *__i in [f1, l1)?
-        _ForwardIterator1 __match = __first1;
-        for (; __match != __i; ++__match)
-            if (__pred(*__match, *__i))
-                break;
-        if (__match == __i) {
-            // Count number of *__i in [f2, l2)
-            _D1 __c2 = 0;
-            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c2;
-            if (__c2 == 0)
-                return false;
-            // Count number of *__i in [__i, l1) (we can start with 1)
-            _D1 __c1 = 1;
-            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c1;
-            if (__c1 != __c2)
-                return false;
-        }
-    }
-    return true;
-}
-
-template<class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::is_permutation(__first1, __last1, __first2, __equal_to<__v1, __v2>());
-}
-
-#if _LIBCPP_STD_VER > 11
-template<class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-                 _ForwardIterator2 __first2, _ForwardIterator2 __last2,
-                 _BinaryPredicate __pred,
-                 forward_iterator_tag, forward_iterator_tag )
-{
-//  shorten sequences as much as possible by lopping of any equal prefix
-    for (; __first1 != __last1 && __first2 != __last2; ++__first1, (void) ++__first2)
-        if (!__pred(*__first1, *__first2))
-            break;
-    if (__first1 == __last1)
-        return __first2 == __last2;
-    else if (__first2 == __last2)
-        return false;
-
-    typedef typename iterator_traits<_ForwardIterator1>::difference_type _D1;
-    _D1 __l1 = _VSTD::distance(__first1, __last1);
-
-    typedef typename iterator_traits<_ForwardIterator2>::difference_type _D2;
-    _D2 __l2 = _VSTD::distance(__first2, __last2);
-    if (__l1 != __l2)
-        return false;
-
-    // For each element in [f1, l1) see if there are the same number of
-    //    equal elements in [f2, l2)
-    for (_ForwardIterator1 __i = __first1; __i != __last1; ++__i)
-    {
-    //  Have we already counted the number of *__i in [f1, l1)?
-        _ForwardIterator1 __match = __first1;
-        for (; __match != __i; ++__match)
-            if (__pred(*__match, *__i))
-                break;
-        if (__match == __i) {
-            // Count number of *__i in [f2, l2)
-            _D1 __c2 = 0;
-            for (_ForwardIterator2 __j = __first2; __j != __last2; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c2;
-            if (__c2 == 0)
-                return false;
-            // Count number of *__i in [__i, l1) (we can start with 1)
-            _D1 __c1 = 1;
-            for (_ForwardIterator1 __j = _VSTD::next(__i); __j != __last1; ++__j)
-                if (__pred(*__i, *__j))
-                    ++__c1;
-            if (__c1 != __c2)
-                return false;
-        }
-    }
-    return true;
-}
-
-template<class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__is_permutation(_RandomAccessIterator1 __first1, _RandomAccessIterator2 __last1,
-               _RandomAccessIterator1 __first2, _RandomAccessIterator2 __last2,
-               _BinaryPredicate __pred,
-               random_access_iterator_tag, random_access_iterator_tag )
-{
-    if ( _VSTD::distance(__first1, __last1) != _VSTD::distance(__first2, __last2))
-        return false;
-    return _VSTD::is_permutation<_RandomAccessIterator1, _RandomAccessIterator2,
-                                 typename add_lvalue_reference<_BinaryPredicate>::type>
-                                (__first1, __last1, __first2, __pred );
-}
-
-template<class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2, _ForwardIterator2 __last2,
-               _BinaryPredicate __pred )
-{
-    return _VSTD::__is_permutation<typename add_lvalue_reference<_BinaryPredicate>::type>
-       (__first1, __last1, __first2, __last2, __pred,
-        typename iterator_traits<_ForwardIterator1>::iterator_category(),
-        typename iterator_traits<_ForwardIterator2>::iterator_category());
-}
-
-template<class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_permutation(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-               _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::__is_permutation(__first1, __last1, __first2, __last2,
-        __equal_to<__v1, __v2>(),
-        typename iterator_traits<_ForwardIterator1>::iterator_category(),
-        typename iterator_traits<_ForwardIterator2>::iterator_category());
-}
-#endif
-
-// search
-// __search is in <functional>
-
-template <class _ForwardIterator1, class _ForwardIterator2, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-       _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred)
-{
-    return _VSTD::__search<typename add_lvalue_reference<_BinaryPredicate>::type>
-                         (__first1, __last1, __first2, __last2, __pred,
-                          typename iterator_traits<_ForwardIterator1>::iterator_category(),
-                          typename iterator_traits<_ForwardIterator2>::iterator_category())
-            .first;
-}
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator1
-search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-       _ForwardIterator2 __first2, _ForwardIterator2 __last2)
-{
-    typedef typename iterator_traits<_ForwardIterator1>::value_type __v1;
-    typedef typename iterator_traits<_ForwardIterator2>::value_type __v2;
-    return _VSTD::search(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>());
-}
-
-
-#if _LIBCPP_STD_VER > 14
-template <class _ForwardIterator, class _Searcher>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
-{ return __s(__f, __l).first; }
-#endif
-
-// search_n
-
-template <class _BinaryPredicate, class _ForwardIterator, class _Size, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__search_n(_ForwardIterator __first, _ForwardIterator __last,
-           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, forward_iterator_tag)
-{
-    if (__count <= 0)
-        return __first;
-    while (true)
-    {
-        // Find first element in sequence that matchs __value_, with a mininum of loop checks
-        while (true)
-        {
-            if (__first == __last)  // return __last if no element matches __value_
-                return __last;
-            if (__pred(*__first, __value_))
-                break;
-            ++__first;
-        }
-        // *__first matches __value_, now match elements after here
-        _ForwardIterator __m = __first;
-        _Size __c(0);
-        while (true)
-        {
-            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
-                return __first;
-            if (++__m == __last)  // Otherwise if source exhaused, pattern not found
-                return __last;
-            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
-            {
-                __first = __m;
-                ++__first;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator, class _Size, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
-__search_n(_RandomAccessIterator __first, _RandomAccessIterator __last,
-           _Size __count, const _Tp& __value_, _BinaryPredicate __pred, random_access_iterator_tag)
-{
-    if (__count <= 0)
-        return __first;
-    _Size __len = static_cast<_Size>(__last - __first);
-    if (__len < __count)
-        return __last;
-    const _RandomAccessIterator __s = __last - (__count - 1);  // Start of pattern match can't go beyond here
-    while (true)
-    {
-        // Find first element in sequence that matchs __value_, with a mininum of loop checks
-        while (true)
-        {
-            if (__first >= __s)  // return __last if no element matches __value_
-                return __last;
-            if (__pred(*__first, __value_))
-                break;
-            ++__first;
-        }
-        // *__first matches __value_, now match elements after here
-        _RandomAccessIterator __m = __first;
-        _Size __c(0);
-        while (true)
-        {
-            if (++__c == __count)  // If pattern exhausted, __first is the answer (works for 1 element pattern)
-                return __first;
-             ++__m;          // no need to check range on __m because __s guarantees we have enough source
-            if (!__pred(*__m, __value_))  // if there is a mismatch, restart with a new __first
-            {
-                __first = __m;
-                ++__first;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _ForwardIterator, class _Size, class _Tp, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-search_n(_ForwardIterator __first, _ForwardIterator __last,
-         _Size __count, const _Tp& __value_, _BinaryPredicate __pred)
-{
-    return _VSTD::__search_n<typename add_lvalue_reference<_BinaryPredicate>::type>
-           (__first, __last, __convert_to_integral(__count), __value_, __pred,
-           typename iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-template <class _ForwardIterator, class _Size, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-search_n(_ForwardIterator __first, _ForwardIterator __last, _Size __count, const _Tp& __value_)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
-    return _VSTD::search_n(__first, __last, __convert_to_integral(__count),
-                           __value_, __equal_to<__v, _Tp>());
-}
-
-// copy
-template <class _Iter>
-inline _LIBCPP_INLINE_VISIBILITY
-_Iter
-__unwrap_iter(_Iter __i)
-{
-    return __i;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_trivially_copy_assignable<_Tp>::value,
-    _Tp*
->::type
-__unwrap_iter(move_iterator<_Tp*> __i)
-{
-    return __i.base();
-}
-
-#if _LIBCPP_DEBUG_LEVEL < 2
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-typename enable_if
-<
-    is_trivially_copy_assignable<_Tp>::value,
-    _Tp*
->::type
-__unwrap_iter(__wrap_iter<_Tp*> __i)
-{
-    return __i.base();
-}
-
-#else
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-typename enable_if
-<
-    is_trivially_copy_assignable<_Tp>::value,
-    __wrap_iter<_Tp*>
->::type
-__unwrap_iter(__wrap_iter<_Tp*> __i)
-{
-    return __i;
-}
-
-#endif  // _LIBCPP_DEBUG_LEVEL < 2
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        *__result = *__first;
-    return __result;
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__copy(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    return __result + __n;
-}
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    return _VSTD::__copy(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
-}
-
-// copy_backward
-
-template <class _BidirectionalIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__copy_backward(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
-{
-    while (__first != __last)
-        *--__result = *--__last;
-    return __result;
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__copy_backward(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-    {
-        __result -= __n;
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    }
-    return __result;
-}
-
-template <class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_INLINE_VISIBILITY
-_BidirectionalIterator2
-copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
-              _BidirectionalIterator2 __result)
-{
-    return _VSTD::__copy_backward(__unwrap_iter(__first),
-                                  __unwrap_iter(__last),
-                                  __unwrap_iter(__result));
-}
-
-// copy_if
-
-template<class _InputIterator, class _OutputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-copy_if(_InputIterator __first, _InputIterator __last,
-        _OutputIterator __result, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-    {
-        if (__pred(*__first))
-        {
-            *__result = *__first;
-            ++__result;
-        }
-    }
-    return __result;
-}
-
-// copy_n
-
-template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_input_iterator<_InputIterator>::value &&
-   !__is_random_access_iterator<_InputIterator>::value,
-    _OutputIterator
->::type
-copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
-{
-    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
-    _IntegralSize __n = __orig_n;
-    if (__n > 0)
-    {
-        *__result = *__first;
-        ++__result;
-        for (--__n; __n > 0; --__n)
-        {
-            ++__first;
-            *__result = *__first;
-            ++__result;
-        }
-    }
-    return __result;
-}
-
-template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_random_access_iterator<_InputIterator>::value,
-    _OutputIterator
->::type
-copy_n(_InputIterator __first, _Size __orig_n, _OutputIterator __result)
-{
-    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
-    _IntegralSize __n = __orig_n;
-    return _VSTD::copy(__first, __first + __n, __result);
-}
-
-// move
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        *__result = _VSTD::move(*__first);
-    return __result;
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__move(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    return __result + __n;
-}
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-move(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    return _VSTD::__move(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
-}
-
-// move_backward
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-__move_backward(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    while (__first != __last)
-        *--__result = _VSTD::move(*--__last);
-    return __result;
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<typename remove_const<_Tp>::type, _Up>::value &&
-    is_trivially_copy_assignable<_Up>::value,
-    _Up*
->::type
-__move_backward(_Tp* __first, _Tp* __last, _Up* __result)
-{
-    const size_t __n = static_cast<size_t>(__last - __first);
-    if (__n > 0)
-    {
-        __result -= __n;
-        _VSTD::memmove(__result, __first, __n * sizeof(_Up));
-    }
-    return __result;
-}
-
-template <class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_INLINE_VISIBILITY
-_BidirectionalIterator2
-move_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
-              _BidirectionalIterator2 __result)
-{
-    return _VSTD::__move_backward(__unwrap_iter(__first), __unwrap_iter(__last), __unwrap_iter(__result));
-}
-
-// iter_swap
-
-// moved to <type_traits> for better swap / noexcept support
-
-// transform
-
-template <class _InputIterator, class _OutputIterator, class _UnaryOperation>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-transform(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _UnaryOperation __op)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        *__result = __op(*__first);
-    return __result;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _BinaryOperation>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-transform(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
-          _OutputIterator __result, _BinaryOperation __binary_op)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2, ++__result)
-        *__result = __binary_op(*__first1, *__first2);
-    return __result;
-}
-
-// replace
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-replace(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __old_value, const _Tp& __new_value)
-{
-    for (; __first != __last; ++__first)
-        if (*__first == __old_value)
-            *__first = __new_value;
-}
-
-// replace_if
-
-template <class _ForwardIterator, class _Predicate, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-replace_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, const _Tp& __new_value)
-{
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            *__first = __new_value;
-}
-
-// replace_copy
-
-template <class _InputIterator, class _OutputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-replace_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
-             const _Tp& __old_value, const _Tp& __new_value)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        if (*__first == __old_value)
-            *__result = __new_value;
-        else
-            *__result = *__first;
-    return __result;
-}
-
-// replace_copy_if
-
-template <class _InputIterator, class _OutputIterator, class _Predicate, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-replace_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
-                _Predicate __pred, const _Tp& __new_value)
-{
-    for (; __first != __last; ++__first, (void) ++__result)
-        if (__pred(*__first))
-            *__result = __new_value;
-        else
-            *__result = *__first;
-    return __result;
-}
-
-// fill_n
-
-template <class _OutputIterator, class _Size, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-__fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
-{
-    for (; __n > 0; ++__first, (void) --__n)
-        *__first = __value_;
-    return __first;
-}
-
-template <class _OutputIterator, class _Size, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-fill_n(_OutputIterator __first, _Size __n, const _Tp& __value_)
-{
-   return _VSTD::__fill_n(__first, __convert_to_integral(__n), __value_);
-}
-
-// fill
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-__fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, forward_iterator_tag)
-{
-    for (; __first != __last; ++__first)
-        *__first = __value_;
-}
-
-template <class _RandomAccessIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-__fill(_RandomAccessIterator __first, _RandomAccessIterator __last, const _Tp& __value_, random_access_iterator_tag)
-{
-    _VSTD::fill_n(__first, __last - __first, __value_);
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-fill(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    _VSTD::__fill(__first, __last, __value_, typename iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-// generate
-
-template <class _ForwardIterator, class _Generator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-void
-generate(_ForwardIterator __first, _ForwardIterator __last, _Generator __gen)
-{
-    for (; __first != __last; ++__first)
-        *__first = __gen();
-}
-
-// generate_n
-
-template <class _OutputIterator, class _Size, class _Generator>
-inline _LIBCPP_INLINE_VISIBILITY  _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-generate_n(_OutputIterator __first, _Size __orig_n, _Generator __gen)
-{
-    typedef decltype(__convert_to_integral(__orig_n)) _IntegralSize;
-    _IntegralSize __n = __orig_n;
-    for (; __n > 0; ++__first, (void) --__n)
-        *__first = __gen();
-    return __first;
-}
-
-// remove
-
-template <class _ForwardIterator, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-remove(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    __first = _VSTD::find(__first, __last, __value_);
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (!(*__i == __value_))
-            {
-                *__first = _VSTD::move(*__i);
-                ++__first;
-            }
-        }
-    }
-    return __first;
-}
-
-// remove_if
-
-template <class _ForwardIterator, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-remove_if(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
-{
-    __first = _VSTD::find_if<_ForwardIterator, typename add_lvalue_reference<_Predicate>::type>
-                           (__first, __last, __pred);
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (!__pred(*__i))
-            {
-                *__first = _VSTD::move(*__i);
-                ++__first;
-            }
-        }
-    }
-    return __first;
-}
-
-// remove_copy
-
-template <class _InputIterator, class _OutputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-remove_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, const _Tp& __value_)
-{
-    for (; __first != __last; ++__first)
-    {
-        if (!(*__first == __value_))
-        {
-            *__result = *__first;
-            ++__result;
-        }
-    }
-    return __result;
-}
-
-// remove_copy_if
-
-template <class _InputIterator, class _OutputIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-remove_copy_if(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-    {
-        if (!__pred(*__first))
-        {
-            *__result = *__first;
-            ++__result;
-        }
-    }
-    return __result;
-}
-
-// unique
-
-template <class _ForwardIterator, class _BinaryPredicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-unique(_ForwardIterator __first, _ForwardIterator __last, _BinaryPredicate __pred)
-{
-    __first = _VSTD::adjacent_find<_ForwardIterator, typename add_lvalue_reference<_BinaryPredicate>::type>
-                                 (__first, __last, __pred);
-    if (__first != __last)
-    {
-        // ...  a  a  ?  ...
-        //      f     i
-        _ForwardIterator __i = __first;
-        for (++__i; ++__i != __last;)
-            if (!__pred(*__first, *__i))
-                *++__first = _VSTD::move(*__i);
-        ++__first;
-    }
-    return __first;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-unique(_ForwardIterator __first, _ForwardIterator __last)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type __v;
-    return _VSTD::unique(__first, __last, __equal_to<__v>());
-}
-
-// unique_copy
-
-template <class _BinaryPredicate, class _InputIterator, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
-__unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
-              input_iterator_tag, output_iterator_tag)
-{
-    if (__first != __last)
-    {
-        typename iterator_traits<_InputIterator>::value_type __t(*__first);
-        *__result = __t;
-        ++__result;
-        while (++__first != __last)
-        {
-            if (!__pred(__t, *__first))
-            {
-                __t = *__first;
-                *__result = __t;
-                ++__result;
-            }
-        }
-    }
-    return __result;
-}
-
-template <class _BinaryPredicate, class _ForwardIterator, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
-__unique_copy(_ForwardIterator __first, _ForwardIterator __last, _OutputIterator __result, _BinaryPredicate __pred,
-              forward_iterator_tag, output_iterator_tag)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        *__result = *__i;
-        ++__result;
-        while (++__first != __last)
-        {
-            if (!__pred(*__i, *__first))
-            {
-                *__result = *__first;
-                ++__result;
-                __i = __first;
-            }
-        }
-    }
-    return __result;
-}
-
-template <class _BinaryPredicate, class _InputIterator, class _ForwardIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__unique_copy(_InputIterator __first, _InputIterator __last, _ForwardIterator __result, _BinaryPredicate __pred,
-              input_iterator_tag, forward_iterator_tag)
-{
-    if (__first != __last)
-    {
-        *__result = *__first;
-        while (++__first != __last)
-            if (!__pred(*__result, *__first))
-                *++__result = *__first;
-        ++__result;
-    }
-    return __result;
-}
-
-template <class _InputIterator, class _OutputIterator, class _BinaryPredicate>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result, _BinaryPredicate __pred)
-{
-    return _VSTD::__unique_copy<typename add_lvalue_reference<_BinaryPredicate>::type>
-                              (__first, __last, __result, __pred,
-                               typename iterator_traits<_InputIterator>::iterator_category(),
-                               typename iterator_traits<_OutputIterator>::iterator_category());
-}
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-unique_copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    typedef typename iterator_traits<_InputIterator>::value_type __v;
-    return _VSTD::unique_copy(__first, __last, __result, __equal_to<__v>());
-}
-
-// reverse
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__reverse(_BidirectionalIterator __first, _BidirectionalIterator __last, bidirectional_iterator_tag)
-{
-    while (__first != __last)
-    {
-        if (__first == --__last)
-            break;
-        _VSTD::iter_swap(__first, __last);
-        ++__first;
-    }
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__reverse(_RandomAccessIterator __first, _RandomAccessIterator __last, random_access_iterator_tag)
-{
-    if (__first != __last)
-        for (; __first < --__last; ++__first)
-            _VSTD::iter_swap(__first, __last);
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-reverse(_BidirectionalIterator __first, _BidirectionalIterator __last)
-{
-    _VSTD::__reverse(__first, __last, typename iterator_traits<_BidirectionalIterator>::iterator_category());
-}
-
-// reverse_copy
-
-template <class _BidirectionalIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-reverse_copy(_BidirectionalIterator __first, _BidirectionalIterator __last, _OutputIterator __result)
-{
-    for (; __first != __last; ++__result)
-        *__result = *--__last;
-    return __result;
-}
-
-// rotate
-
-template <class _ForwardIterator>
-_ForwardIterator
-__rotate_left(_ForwardIterator __first, _ForwardIterator __last)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-    value_type __tmp = _VSTD::move(*__first);
-    _ForwardIterator __lm1 = _VSTD::move(_VSTD::next(__first), __last, __first);
-    *__lm1 = _VSTD::move(__tmp);
-    return __lm1;
-}
-
-template <class _BidirectionalIterator>
-_BidirectionalIterator
-__rotate_right(_BidirectionalIterator __first, _BidirectionalIterator __last)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    _BidirectionalIterator __lm1 = _VSTD::prev(__last);
-    value_type __tmp = _VSTD::move(*__lm1);
-    _BidirectionalIterator __fp1 = _VSTD::move_backward(__first, __lm1, __last);
-    *__first = _VSTD::move(__tmp);
-    return __fp1;
-}
-
-template <class _ForwardIterator>
-_ForwardIterator
-__rotate_forward(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
-{
-    _ForwardIterator __i = __middle;
-    while (true)
-    {
-        swap(*__first, *__i);
-        ++__first;
-        if (++__i == __last)
-            break;
-        if (__first == __middle)
-            __middle = __i;
-    }
-    _ForwardIterator __r = __first;
-    if (__first != __middle)
-    {
-        __i = __middle;
-        while (true)
-        {
-            swap(*__first, *__i);
-            ++__first;
-            if (++__i == __last)
-            {
-                if (__first == __middle)
-                    break;
-                __i = __middle;
-            }
-            else if (__first == __middle)
-                __middle = __i;
-        }
-    }
-    return __r;
-}
-
-template<typename _Integral>
-inline _LIBCPP_INLINE_VISIBILITY
-_Integral
-__algo_gcd(_Integral __x, _Integral __y)
-{
-    do
-    {
-        _Integral __t = __x % __y;
-        __x = __y;
-        __y = __t;
-    } while (__y);
-    return __x;
-}
-
-template<typename _RandomAccessIterator>
-_RandomAccessIterator
-__rotate_gcd(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-
-    const difference_type __m1 = __middle - __first;
-    const difference_type __m2 = __last - __middle;
-    if (__m1 == __m2)
-    {
-        _VSTD::swap_ranges(__first, __middle, __middle);
-        return __middle;
-    }
-    const difference_type __g = _VSTD::__algo_gcd(__m1, __m2);
-    for (_RandomAccessIterator __p = __first + __g; __p != __first;)
-    {
-        value_type __t(_VSTD::move(*--__p));
-        _RandomAccessIterator __p1 = __p;
-        _RandomAccessIterator __p2 = __p1 + __m1;
-        do
-        {
-            *__p1 = _VSTD::move(*__p2);
-            __p1 = __p2;
-            const difference_type __d = __last - __p2;
-            if (__m1 < __d)
-                __p2 += __m1;
-            else
-                __p2 = __first + (__m1 - __d);
-        } while (__p2 != __p);
-        *__p1 = _VSTD::move(__t);
-    }
-    return __first + __m2;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator
-__rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last,
-         _VSTD::forward_iterator_tag)
-{
-    typedef typename _VSTD::iterator_traits<_ForwardIterator>::value_type value_type;
-    if (_VSTD::is_trivially_move_assignable<value_type>::value)
-    {
-        if (_VSTD::next(__first) == __middle)
-            return _VSTD::__rotate_left(__first, __last);
-    }
-    return _VSTD::__rotate_forward(__first, __middle, __last);
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_BidirectionalIterator
-__rotate(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
-         _VSTD::bidirectional_iterator_tag)
-{
-    typedef typename _VSTD::iterator_traits<_BidirectionalIterator>::value_type value_type;
-    if (_VSTD::is_trivially_move_assignable<value_type>::value)
-    {
-        if (_VSTD::next(__first) == __middle)
-            return _VSTD::__rotate_left(__first, __last);
-        if (_VSTD::next(__middle) == __last)
-            return _VSTD::__rotate_right(__first, __last);
-    }
-    return _VSTD::__rotate_forward(__first, __middle, __last);
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_RandomAccessIterator
-__rotate(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
-         _VSTD::random_access_iterator_tag)
-{
-    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::value_type value_type;
-    if (_VSTD::is_trivially_move_assignable<value_type>::value)
-    {
-        if (_VSTD::next(__first) == __middle)
-            return _VSTD::__rotate_left(__first, __last);
-        if (_VSTD::next(__middle) == __last)
-            return _VSTD::__rotate_right(__first, __last);
-        return _VSTD::__rotate_gcd(__first, __middle, __last);
-    }
-    return _VSTD::__rotate_forward(__first, __middle, __last);
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator
-rotate(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last)
-{
-    if (__first == __middle)
-        return __last;
-    if (__middle == __last)
-        return __first;
-    return _VSTD::__rotate(__first, __middle, __last,
-                           typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-// rotate_copy
-
-template <class _ForwardIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-rotate_copy(_ForwardIterator __first, _ForwardIterator __middle, _ForwardIterator __last, _OutputIterator __result)
-{
-    return _VSTD::copy(__first, __middle, _VSTD::copy(__middle, __last, __result));
-}
-
-// min_element
-
-template <class _ForwardIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_ForwardIterator
-min_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-    static_assert(__is_forward_iterator<_ForwardIterator>::value,
-        "std::min_element requires a ForwardIterator");
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-            if (__comp(*__i, *__first))
-                __first = __i;
-    }
-    return __first;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_ForwardIterator
-min_element(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::min_element(__first, __last,
-              __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// min
-
-template <class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-min(const _Tp& __a, const _Tp& __b, _Compare __comp)
-{
-    return __comp(__b, __a) ? __b : __a;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-min(const _Tp& __a, const _Tp& __b)
-{
-    return _VSTD::min(__a, __b, __less<_Tp>());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-min(initializer_list<_Tp> __t, _Compare __comp)
-{
-    return *_VSTD::min_element(__t.begin(), __t.end(), __comp);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-min(initializer_list<_Tp> __t)
-{
-    return *_VSTD::min_element(__t.begin(), __t.end(), __less<_Tp>());
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-// max_element
-
-template <class _ForwardIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_ForwardIterator
-max_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-    static_assert(__is_forward_iterator<_ForwardIterator>::value,
-        "std::max_element requires a ForwardIterator");
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-            if (__comp(*__first, *__i))
-                __first = __i;
-    }
-    return __first;
-}
-
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_ForwardIterator
-max_element(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::max_element(__first, __last,
-              __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// max
-
-template <class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-max(const _Tp& __a, const _Tp& __b, _Compare __comp)
-{
-    return __comp(__a, __b) ? __b : __a;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-max(const _Tp& __a, const _Tp& __b)
-{
-    return _VSTD::max(__a, __b, __less<_Tp>());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-max(initializer_list<_Tp> __t, _Compare __comp)
-{
-    return *_VSTD::max_element(__t.begin(), __t.end(), __comp);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-max(initializer_list<_Tp> __t)
-{
-    return *_VSTD::max_element(__t.begin(), __t.end(), __less<_Tp>());
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER > 14
-// clamp
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-const _Tp&
-clamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi, _Compare __comp)
-{
-    _LIBCPP_ASSERT(!__comp(__hi, __lo), "Bad bounds passed to std::clamp");
-    return __comp(__v, __lo) ? __lo : __comp(__hi, __v) ? __hi : __v;
-
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-const _Tp&
-clamp(const _Tp& __v, const _Tp& __lo, const _Tp& __hi)
-{
-    return _VSTD::clamp(__v, __lo, __hi, __less<_Tp>());
-}
-#endif
-
-// minmax_element
-
-template <class _ForwardIterator, class _Compare>
-_LIBCPP_CONSTEXPR_AFTER_CXX11
-std::pair<_ForwardIterator, _ForwardIterator>
-minmax_element(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-  static_assert(__is_forward_iterator<_ForwardIterator>::value,
-        "std::minmax_element requires a ForwardIterator");
-  std::pair<_ForwardIterator, _ForwardIterator> __result(__first, __first);
-  if (__first != __last)
-  {
-      if (++__first != __last)
-      {
-          if (__comp(*__first, *__result.first))
-              __result.first = __first;
-          else
-              __result.second = __first;
-          while (++__first != __last)
-          {
-              _ForwardIterator __i = __first;
-              if (++__first == __last)
-              {
-                  if (__comp(*__i, *__result.first))
-                      __result.first = __i;
-                  else if (!__comp(*__i, *__result.second))
-                      __result.second = __i;
-                  break;
-              }
-              else
-              {
-                  if (__comp(*__first, *__i))
-                  {
-                      if (__comp(*__first, *__result.first))
-                          __result.first = __first;
-                      if (!__comp(*__i, *__result.second))
-                          __result.second = __i;
-                  }
-                  else
-                  {
-                      if (__comp(*__i, *__result.first))
-                          __result.first = __i;
-                      if (!__comp(*__first, *__result.second))
-                          __result.second = __first;
-                  }
-              }
-          }
-      }
-  }
-  return __result;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-std::pair<_ForwardIterator, _ForwardIterator>
-minmax_element(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::minmax_element(__first, __last,
-              __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// minmax
-
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<const _Tp&, const _Tp&>
-minmax(const _Tp& __a, const _Tp& __b, _Compare __comp)
-{
-    return __comp(__b, __a) ? pair<const _Tp&, const _Tp&>(__b, __a) :
-                              pair<const _Tp&, const _Tp&>(__a, __b);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<const _Tp&, const _Tp&>
-minmax(const _Tp& __a, const _Tp& __b)
-{
-    return _VSTD::minmax(__a, __b, __less<_Tp>());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<_Tp, _Tp>
-minmax(initializer_list<_Tp> __t, _Compare __comp)
-{
-    typedef typename initializer_list<_Tp>::const_iterator _Iter;
-    _Iter __first = __t.begin();
-    _Iter __last  = __t.end();
-    std::pair<_Tp, _Tp> __result(*__first, *__first);
-
-    ++__first;
-    if (__t.size() % 2 == 0)
-    {
-        if (__comp(*__first,  __result.first))
-            __result.first  = *__first;
-        else
-            __result.second = *__first;
-        ++__first;
-    }
-
-    while (__first != __last)
-    {
-        _Tp __prev = *__first++;
-        if (__comp(*__first, __prev)) {
-            if ( __comp(*__first, __result.first)) __result.first  = *__first;
-            if (!__comp(__prev, __result.second))  __result.second = __prev;
-            }
-        else {
-            if ( __comp(__prev, __result.first))    __result.first  = __prev;
-            if (!__comp(*__first, __result.second)) __result.second = *__first;
-            }
-
-        __first++;
-    }
-    return __result;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<_Tp, _Tp>
-minmax(initializer_list<_Tp> __t)
-{
-    return _VSTD::minmax(__t, __less<_Tp>());
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-// random_shuffle
-
-// __independent_bits_engine
-
-template <unsigned long long _Xp, size_t _Rp>
-struct __log2_imp
-{
-    static const size_t value = _Xp & ((unsigned long long)(1) << _Rp) ? _Rp
-                                           : __log2_imp<_Xp, _Rp - 1>::value;
-};
-
-template <unsigned long long _Xp>
-struct __log2_imp<_Xp, 0>
-{
-    static const size_t value = 0;
-};
-
-template <size_t _Rp>
-struct __log2_imp<0, _Rp>
-{
-    static const size_t value = _Rp + 1;
-};
-
-template <class _UIntType, _UIntType _Xp>
-struct __log2
-{
-    static const size_t value = __log2_imp<_Xp,
-                                         sizeof(_UIntType) * __CHAR_BIT__ - 1>::value;
-};
-
-template<class _Engine, class _UIntType>
-class __independent_bits_engine
-{
-public:
-    // types
-    typedef _UIntType result_type;
-
-private:
-    typedef typename _Engine::result_type _Engine_result_type;
-    typedef typename conditional
-        <
-            sizeof(_Engine_result_type) <= sizeof(result_type),
-                result_type,
-                _Engine_result_type
-        >::type _Working_result_type;
-
-    _Engine& __e_;
-    size_t __w_;
-    size_t __w0_;
-    size_t __n_;
-    size_t __n0_;
-    _Working_result_type __y0_;
-    _Working_result_type __y1_;
-    _Engine_result_type __mask0_;
-    _Engine_result_type __mask1_;
-
-#ifdef _LIBCPP_CXX03_LANG
-    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
-                                          + _Working_result_type(1);
-#else
-    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
-                                                      + _Working_result_type(1);
-#endif
-    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
-    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
-    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
-
-public:
-    // constructors and seeding functions
-    __independent_bits_engine(_Engine& __e, size_t __w);
-
-    // generating functions
-    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
-
-private:
-    result_type __eval(false_type);
-    result_type __eval(true_type);
-};
-
-template<class _Engine, class _UIntType>
-__independent_bits_engine<_Engine, _UIntType>
-    ::__independent_bits_engine(_Engine& __e, size_t __w)
-        : __e_(__e),
-          __w_(__w)
-{
-    __n_ = __w_ / __m + (__w_ % __m != 0);
-    __w0_ = __w_ / __n_;
-    if (_Rp == 0)
-        __y0_ = _Rp;
-    else if (__w0_ < _WDt)
-        __y0_ = (_Rp >> __w0_) << __w0_;
-    else
-        __y0_ = 0;
-    if (_Rp - __y0_ > __y0_ / __n_)
-    {
-        ++__n_;
-        __w0_ = __w_ / __n_;
-        if (__w0_ < _WDt)
-            __y0_ = (_Rp >> __w0_) << __w0_;
-        else
-            __y0_ = 0;
-    }
-    __n0_ = __n_ - __w_ % __n_;
-    if (__w0_ < _WDt - 1)
-        __y1_ = (_Rp >> (__w0_ + 1)) << (__w0_ + 1);
-    else
-        __y1_ = 0;
-    __mask0_ = __w0_ > 0 ? _Engine_result_type(~0) >> (_EDt - __w0_) :
-                          _Engine_result_type(0);
-    __mask1_ = __w0_ < _EDt - 1 ?
-                               _Engine_result_type(~0) >> (_EDt - (__w0_ + 1)) :
-                               _Engine_result_type(~0);
-}
-
-template<class _Engine, class _UIntType>
-inline
-_UIntType
-__independent_bits_engine<_Engine, _UIntType>::__eval(false_type)
-{
-    return static_cast<result_type>(__e_() & __mask0_);
-}
-
-template<class _Engine, class _UIntType>
-_UIntType
-__independent_bits_engine<_Engine, _UIntType>::__eval(true_type)
-{
-    const size_t _WRt = numeric_limits<result_type>::digits;
-    result_type _Sp = 0;
-    for (size_t __k = 0; __k < __n0_; ++__k)
-    {
-        _Engine_result_type __u;
-        do
-        {
-            __u = __e_() - _Engine::min();
-        } while (__u >= __y0_);
-        if (__w0_ < _WRt)
-            _Sp <<= __w0_;
-        else
-            _Sp = 0;
-        _Sp += __u & __mask0_;
-    }
-    for (size_t __k = __n0_; __k < __n_; ++__k)
-    {
-        _Engine_result_type __u;
-        do
-        {
-            __u = __e_() - _Engine::min();
-        } while (__u >= __y1_);
-        if (__w0_ < _WRt - 1)
-            _Sp <<= __w0_ + 1;
-        else
-            _Sp = 0;
-        _Sp += __u & __mask1_;
-    }
-    return _Sp;
-}
-
-// uniform_int_distribution
-
-template<class _IntType = int>
-class uniform_int_distribution
-{
-public:
-    // types
-    typedef _IntType result_type;
-
-    class param_type
-    {
-        result_type __a_;
-        result_type __b_;
-    public:
-        typedef uniform_int_distribution distribution_type;
-
-        explicit param_type(result_type __a = 0,
-                            result_type __b = numeric_limits<result_type>::max())
-            : __a_(__a), __b_(__b) {}
-
-        result_type a() const {return __a_;}
-        result_type b() const {return __b_;}
-
-        friend bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
-        friend bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructors and reset functions
-    explicit uniform_int_distribution(result_type __a = 0,
-                                      result_type __b = numeric_limits<result_type>::max())
-        : __p_(param_type(__a, __b)) {}
-    explicit uniform_int_distribution(const param_type& __p) : __p_(__p) {}
-    void reset() {}
-
-    // generating functions
-    template<class _URNG> result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    result_type a() const {return __p_.a();}
-    result_type b() const {return __p_.b();}
-
-    param_type param() const {return __p_;}
-    void param(const param_type& __p) {__p_ = __p;}
-
-    result_type min() const {return a();}
-    result_type max() const {return b();}
-
-    friend bool operator==(const uniform_int_distribution& __x,
-                           const uniform_int_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend bool operator!=(const uniform_int_distribution& __x,
-                           const uniform_int_distribution& __y)
-            {return !(__x == __y);}
-};
-
-template<class _IntType>
-template<class _URNG>
-typename uniform_int_distribution<_IntType>::result_type
-uniform_int_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
-_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-{
-    typedef typename conditional<sizeof(result_type) <= sizeof(uint32_t),
-                                            uint32_t, uint64_t>::type _UIntType;
-    const _UIntType _Rp = _UIntType(__p.b()) - _UIntType(__p.a()) + _UIntType(1);
-    if (_Rp == 1)
-        return __p.a();
-    const size_t _Dt = numeric_limits<_UIntType>::digits;
-    typedef __independent_bits_engine<_URNG, _UIntType> _Eng;
-    if (_Rp == 0)
-        return static_cast<result_type>(_Eng(__g, _Dt)());
-    size_t __w = _Dt - __clz(_Rp) - 1;
-    if ((_Rp & (std::numeric_limits<_UIntType>::max() >> (_Dt - __w))) != 0)
-        ++__w;
-    _Eng __e(__g, __w);
-    _UIntType __u;
-    do
-    {
-        __u = __e();
-    } while (__u >= _Rp);
-    return static_cast<result_type>(__u + __p.a());
-}
-
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_RANDOM_SHUFFLE) \
-  || defined(_LIBCPP_BUILDING_LIBRARY)
-class _LIBCPP_TYPE_VIS __rs_default;
-
-_LIBCPP_FUNC_VIS __rs_default __rs_get();
-
-class _LIBCPP_TYPE_VIS __rs_default
-{
-    static unsigned __c_;
-
-    __rs_default();
-public:
-    typedef uint_fast32_t result_type;
-
-    static const result_type _Min = 0;
-    static const result_type _Max = 0xFFFFFFFF;
-
-    __rs_default(const __rs_default&);
-    ~__rs_default();
-
-    result_type operator()();
-
-    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
-    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
-
-    friend _LIBCPP_FUNC_VIS __rs_default __rs_get();
-};
-
-_LIBCPP_FUNC_VIS __rs_default __rs_get();
-
-template <class _RandomAccessIterator>
-_LIBCPP_DEPRECATED_IN_CXX14 void
-random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef uniform_int_distribution<ptrdiff_t> _Dp;
-    typedef typename _Dp::param_type _Pp;
-    difference_type __d = __last - __first;
-    if (__d > 1)
-    {
-        _Dp __uid;
-        __rs_default __g = __rs_get();
-        for (--__last, --__d; __first < __last; ++__first, --__d)
-        {
-            difference_type __i = __uid(__g, _Pp(0, __d));
-            if (__i != difference_type(0))
-                swap(*__first, *(__first + __i));
-        }
-    }
-}
-
-template <class _RandomAccessIterator, class _RandomNumberGenerator>
-_LIBCPP_DEPRECATED_IN_CXX14 void
-random_shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
-#ifndef _LIBCPP_CXX03_LANG
-               _RandomNumberGenerator&& __rand)
-#else
-               _RandomNumberGenerator& __rand)
-#endif
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    difference_type __d = __last - __first;
-    if (__d > 1)
-    {
-        for (--__last; __first < __last; ++__first, --__d)
-        {
-            difference_type __i = __rand(__d);
-            if (__i != difference_type(0))
-              swap(*__first, *(__first + __i));
-        }
-    }
-}
-#endif
-
-template <class _PopulationIterator, class _SampleIterator, class _Distance,
-          class _UniformRandomNumberGenerator>
-_LIBCPP_INLINE_VISIBILITY
-_SampleIterator __sample(_PopulationIterator __first,
-                         _PopulationIterator __last, _SampleIterator __output_iter,
-                         _Distance __n,
-                         _UniformRandomNumberGenerator & __g,
-                         input_iterator_tag) {
-
-  _Distance __k = 0;
-  for (; __first != __last && __k < __n; ++__first, (void)++__k)
-    __output_iter[__k] = *__first;
-  _Distance __sz = __k;
-  for (; __first != __last; ++__first, (void)++__k) {
-    _Distance __r = _VSTD::uniform_int_distribution<_Distance>(0, __k)(__g);
-    if (__r < __sz)
-      __output_iter[__r] = *__first;
-  }
-  return __output_iter + _VSTD::min(__n, __k);
-}
-
-template <class _PopulationIterator, class _SampleIterator, class _Distance,
-          class _UniformRandomNumberGenerator>
-_LIBCPP_INLINE_VISIBILITY
-_SampleIterator __sample(_PopulationIterator __first,
-                         _PopulationIterator __last, _SampleIterator __output_iter,
-                         _Distance __n,
-                         _UniformRandomNumberGenerator& __g,
-                         forward_iterator_tag) {
-  _Distance __unsampled_sz = _VSTD::distance(__first, __last);
-  for (__n = _VSTD::min(__n, __unsampled_sz); __n != 0; ++__first) {
-    _Distance __r =
-        _VSTD::uniform_int_distribution<_Distance>(0, --__unsampled_sz)(__g);
-    if (__r < __n) {
-      *__output_iter++ = *__first;
-      --__n;
-    }
-  }
-  return __output_iter;
-}
-
-template <class _PopulationIterator, class _SampleIterator, class _Distance,
-          class _UniformRandomNumberGenerator>
-_LIBCPP_INLINE_VISIBILITY
-_SampleIterator __sample(_PopulationIterator __first,
-                         _PopulationIterator __last, _SampleIterator __output_iter,
-                         _Distance __n, _UniformRandomNumberGenerator& __g) {
-  typedef typename iterator_traits<_PopulationIterator>::iterator_category
-        _PopCategory;
-  typedef typename iterator_traits<_PopulationIterator>::difference_type
-        _Difference;
-  static_assert(__is_forward_iterator<_PopulationIterator>::value ||
-                __is_random_access_iterator<_SampleIterator>::value,
-                "SampleIterator must meet the requirements of RandomAccessIterator");
-  typedef typename common_type<_Distance, _Difference>::type _CommonType;
-  _LIBCPP_ASSERT(__n >= 0, "N must be a positive number.");
-  return _VSTD::__sample(
-      __first, __last, __output_iter, _CommonType(__n),
-      __g, _PopCategory());
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _PopulationIterator, class _SampleIterator, class _Distance,
-          class _UniformRandomNumberGenerator>
-inline _LIBCPP_INLINE_VISIBILITY
-_SampleIterator sample(_PopulationIterator __first,
-                       _PopulationIterator __last, _SampleIterator __output_iter,
-                       _Distance __n, _UniformRandomNumberGenerator&& __g) {
-    return _VSTD::__sample(__first, __last, __output_iter, __n, __g);
-}
-#endif // _LIBCPP_STD_VER > 14
-
-template<class _RandomAccessIterator, class _UniformRandomNumberGenerator>
-    void shuffle(_RandomAccessIterator __first, _RandomAccessIterator __last,
-#ifndef _LIBCPP_CXX03_LANG
-                 _UniformRandomNumberGenerator&& __g)
-#else
-                 _UniformRandomNumberGenerator& __g)
-#endif
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef uniform_int_distribution<ptrdiff_t> _Dp;
-    typedef typename _Dp::param_type _Pp;
-    difference_type __d = __last - __first;
-    if (__d > 1)
-    {
-        _Dp __uid;
-        for (--__last, --__d; __first < __last; ++__first, --__d)
-        {
-            difference_type __i = __uid(__g, _Pp(0, __d));
-            if (__i != difference_type(0))
-                swap(*__first, *(__first + __i));
-        }
-    }
-}
-
-template <class _InputIterator, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-is_partitioned(_InputIterator __first, _InputIterator __last, _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-        if (!__pred(*__first))
-            break;
-    if ( __first == __last )
-        return true;
-    ++__first;
-    for (; __first != __last; ++__first)
-        if (__pred(*__first))
-            return false;
-    return true;
-}
-
-// partition
-
-template <class _Predicate, class _ForwardIterator>
-_ForwardIterator
-__partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred, forward_iterator_tag)
-{
-    while (true)
-    {
-        if (__first == __last)
-            return __first;
-        if (!__pred(*__first))
-            break;
-        ++__first;
-    }
-    for (_ForwardIterator __p = __first; ++__p != __last;)
-    {
-        if (__pred(*__p))
-        {
-            swap(*__first, *__p);
-            ++__first;
-        }
-    }
-    return __first;
-}
-
-template <class _Predicate, class _BidirectionalIterator>
-_BidirectionalIterator
-__partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
-            bidirectional_iterator_tag)
-{
-    while (true)
-    {
-        while (true)
-        {
-            if (__first == __last)
-                return __first;
-            if (!__pred(*__first))
-                break;
-            ++__first;
-        }
-        do
-        {
-            if (__first == --__last)
-                return __first;
-        } while (!__pred(*__last));
-        swap(*__first, *__last);
-        ++__first;
-    }
-}
-
-template <class _ForwardIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator
-partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
-{
-    return _VSTD::__partition<typename add_lvalue_reference<_Predicate>::type>
-                            (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-// partition_copy
-
-template <class _InputIterator, class _OutputIterator1,
-          class _OutputIterator2, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_OutputIterator1, _OutputIterator2>
-partition_copy(_InputIterator __first, _InputIterator __last,
-               _OutputIterator1 __out_true, _OutputIterator2 __out_false,
-               _Predicate __pred)
-{
-    for (; __first != __last; ++__first)
-    {
-        if (__pred(*__first))
-        {
-            *__out_true = *__first;
-            ++__out_true;
-        }
-        else
-        {
-            *__out_false = *__first;
-            ++__out_false;
-        }
-    }
-    return pair<_OutputIterator1, _OutputIterator2>(__out_true, __out_false);
-}
-
-// partition_point
-
-template<class _ForwardIterator, class _Predicate>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-partition_point(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
-{
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    while (__len != 0)
-    {
-        difference_type __l2 = _VSTD::__half_positive(__len);
-        _ForwardIterator __m = __first;
-        _VSTD::advance(__m, __l2);
-        if (__pred(*__m))
-        {
-            __first = ++__m;
-            __len -= __l2 + 1;
-        }
-        else
-            __len = __l2;
-    }
-    return __first;
-}
-
-// stable_partition
-
-template <class _Predicate, class _ForwardIterator, class _Distance, class _Pair>
-_ForwardIterator
-__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
-                   _Distance __len, _Pair __p, forward_iterator_tag __fit)
-{
-    // *__first is known to be false
-    // __len >= 1
-    if (__len == 1)
-        return __first;
-    if (__len == 2)
-    {
-        _ForwardIterator __m = __first;
-        if (__pred(*++__m))
-        {
-            swap(*__first, *__m);
-            return __m;
-        }
-        return __first;
-    }
-    if (__len <= __p.second)
-    {   // The buffer is big enough to use
-        typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
-        // Move the falses into the temporary buffer, and the trues to the front of the line
-        // Update __first to always point to the end of the trues
-        value_type* __t = __p.first;
-        ::new(__t) value_type(_VSTD::move(*__first));
-        __d.__incr((value_type*)0);
-        ++__t;
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (__pred(*__i))
-            {
-                *__first = _VSTD::move(*__i);
-                ++__first;
-            }
-            else
-            {
-                ::new(__t) value_type(_VSTD::move(*__i));
-                __d.__incr((value_type*)0);
-                ++__t;
-            }
-        }
-        // All trues now at start of range, all falses in buffer
-        // Move falses back into range, but don't mess up __first which points to first false
-        __i = __first;
-        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
-            *__i = _VSTD::move(*__t2);
-        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
-        return __first;
-    }
-    // Else not enough buffer, do in place
-    // __len >= 3
-    _ForwardIterator __m = __first;
-    _Distance __len2 = __len / 2;  // __len2 >= 2
-    _VSTD::advance(__m, __len2);
-    // recurse on [__first, __m), *__first know to be false
-    // F?????????????????
-    // f       m         l
-    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
-    _ForwardIterator __first_false = __stable_partition<_PredRef>(__first, __m, __pred, __len2, __p, __fit);
-    // TTTFFFFF??????????
-    // f  ff   m         l
-    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
-    _ForwardIterator __m1 = __m;
-    _ForwardIterator __second_false = __last;
-    _Distance __len_half = __len - __len2;
-    while (__pred(*__m1))
-    {
-        if (++__m1 == __last)
-            goto __second_half_done;
-        --__len_half;
-    }
-    // TTTFFFFFTTTF??????
-    // f  ff   m  m1     l
-    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __fit);
-__second_half_done:
-    // TTTFFFFFTTTTTFFFFF
-    // f  ff   m    sf   l
-    return _VSTD::rotate(__first_false, __m, __second_false);
-    // TTTTTTTTFFFFFFFFFF
-    //         |
-}
-
-struct __return_temporary_buffer
-{
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) const {_VSTD::return_temporary_buffer(__p);}
-};
-
-template <class _Predicate, class _ForwardIterator>
-_ForwardIterator
-__stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred,
-                   forward_iterator_tag)
-{
-    const unsigned __alloc_limit = 3;  // might want to make this a function of trivial assignment
-    // Either prove all true and return __first or point to first false
-    while (true)
-    {
-        if (__first == __last)
-            return __first;
-        if (!__pred(*__first))
-            break;
-        ++__first;
-    }
-    // We now have a reduced range [__first, __last)
-    // *__first is known to be false
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    pair<value_type*, ptrdiff_t> __p(0, 0);
-    unique_ptr<value_type, __return_temporary_buffer> __h;
-    if (__len >= __alloc_limit)
-    {
-        __p = _VSTD::get_temporary_buffer<value_type>(__len);
-        __h.reset(__p.first);
-    }
-    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
-                             (__first, __last, __pred, __len, __p, forward_iterator_tag());
-}
-
-template <class _Predicate, class _BidirectionalIterator, class _Distance, class _Pair>
-_BidirectionalIterator
-__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
-                   _Distance __len, _Pair __p, bidirectional_iterator_tag __bit)
-{
-    // *__first is known to be false
-    // *__last is known to be true
-    // __len >= 2
-    if (__len == 2)
-    {
-        swap(*__first, *__last);
-        return __last;
-    }
-    if (__len == 3)
-    {
-        _BidirectionalIterator __m = __first;
-        if (__pred(*++__m))
-        {
-            swap(*__first, *__m);
-            swap(*__m, *__last);
-            return __last;
-        }
-        swap(*__m, *__last);
-        swap(*__first, *__m);
-        return __m;
-    }
-    if (__len <= __p.second)
-    {   // The buffer is big enough to use
-        typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h(__p.first, __d);
-        // Move the falses into the temporary buffer, and the trues to the front of the line
-        // Update __first to always point to the end of the trues
-        value_type* __t = __p.first;
-        ::new(__t) value_type(_VSTD::move(*__first));
-        __d.__incr((value_type*)0);
-        ++__t;
-        _BidirectionalIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (__pred(*__i))
-            {
-                *__first = _VSTD::move(*__i);
-                ++__first;
-            }
-            else
-            {
-                ::new(__t) value_type(_VSTD::move(*__i));
-                __d.__incr((value_type*)0);
-                ++__t;
-            }
-        }
-        // move *__last, known to be true
-        *__first = _VSTD::move(*__i);
-        __i = ++__first;
-        // All trues now at start of range, all falses in buffer
-        // Move falses back into range, but don't mess up __first which points to first false
-        for (value_type* __t2 = __p.first; __t2 < __t; ++__t2, ++__i)
-            *__i = _VSTD::move(*__t2);
-        // __h destructs moved-from values out of the temp buffer, but doesn't deallocate buffer
-        return __first;
-    }
-    // Else not enough buffer, do in place
-    // __len >= 4
-    _BidirectionalIterator __m = __first;
-    _Distance __len2 = __len / 2;  // __len2 >= 2
-    _VSTD::advance(__m, __len2);
-    // recurse on [__first, __m-1], except reduce __m-1 until *(__m-1) is true, *__first know to be false
-    // F????????????????T
-    // f       m        l
-    _BidirectionalIterator __m1 = __m;
-    _BidirectionalIterator __first_false = __first;
-    _Distance __len_half = __len2;
-    while (!__pred(*--__m1))
-    {
-        if (__m1 == __first)
-            goto __first_half_done;
-        --__len_half;
-    }
-    // F???TFFF?????????T
-    // f   m1  m        l
-    typedef typename add_lvalue_reference<_Predicate>::type _PredRef;
-    __first_false = __stable_partition<_PredRef>(__first, __m1, __pred, __len_half, __p, __bit);
-__first_half_done:
-    // TTTFFFFF?????????T
-    // f  ff   m        l
-    // recurse on [__m, __last], except increase __m until *(__m) is false, *__last know to be true
-    __m1 = __m;
-    _BidirectionalIterator __second_false = __last;
-    ++__second_false;
-    __len_half = __len - __len2;
-    while (__pred(*__m1))
-    {
-        if (++__m1 == __last)
-            goto __second_half_done;
-        --__len_half;
-    }
-    // TTTFFFFFTTTF?????T
-    // f  ff   m  m1    l
-    __second_false = __stable_partition<_PredRef>(__m1, __last, __pred, __len_half, __p, __bit);
-__second_half_done:
-    // TTTFFFFFTTTTTFFFFF
-    // f  ff   m    sf  l
-    return _VSTD::rotate(__first_false, __m, __second_false);
-    // TTTTTTTTFFFFFFFFFF
-    //         |
-}
-
-template <class _Predicate, class _BidirectionalIterator>
-_BidirectionalIterator
-__stable_partition(_BidirectionalIterator __first, _BidirectionalIterator __last, _Predicate __pred,
-                   bidirectional_iterator_tag)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    const difference_type __alloc_limit = 4;  // might want to make this a function of trivial assignment
-    // Either prove all true and return __first or point to first false
-    while (true)
-    {
-        if (__first == __last)
-            return __first;
-        if (!__pred(*__first))
-            break;
-        ++__first;
-    }
-    // __first points to first false, everything prior to __first is already set.
-    // Either prove [__first, __last) is all false and return __first, or point __last to last true
-    do
-    {
-        if (__first == --__last)
-            return __first;
-    } while (!__pred(*__last));
-    // We now have a reduced range [__first, __last]
-    // *__first is known to be false
-    // *__last is known to be true
-    // __len >= 2
-    difference_type __len = _VSTD::distance(__first, __last) + 1;
-    pair<value_type*, ptrdiff_t> __p(0, 0);
-    unique_ptr<value_type, __return_temporary_buffer> __h;
-    if (__len >= __alloc_limit)
-    {
-        __p = _VSTD::get_temporary_buffer<value_type>(__len);
-        __h.reset(__p.first);
-    }
-    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
-                             (__first, __last, __pred, __len, __p, bidirectional_iterator_tag());
-}
-
-template <class _ForwardIterator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator
-stable_partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred)
-{
-    return __stable_partition<typename add_lvalue_reference<_Predicate>::type>
-                             (__first, __last, __pred, typename iterator_traits<_ForwardIterator>::iterator_category());
-}
-
-// is_sorted_until
-
-template <class _ForwardIterator, class _Compare>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-is_sorted_until(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __i = __first;
-        while (++__i != __last)
-        {
-            if (__comp(*__i, *__first))
-                return __i;
-            __first = __i;
-        }
-    }
-    return __last;
-}
-
-template<class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-is_sorted_until(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::is_sorted_until(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// is_sorted
-
-template <class _ForwardIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_sorted(_ForwardIterator __first, _ForwardIterator __last, _Compare __comp)
-{
-    return _VSTD::is_sorted_until(__first, __last, __comp) == __last;
-}
-
-template<class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_sorted(_ForwardIterator __first, _ForwardIterator __last)
-{
-    return _VSTD::is_sorted(__first, __last, __less<typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// sort
-
-// stable, 2-3 compares, 0-2 swaps
-
-template <class _Compare, class _ForwardIterator>
-unsigned
-__sort3(_ForwardIterator __x, _ForwardIterator __y, _ForwardIterator __z, _Compare __c)
-{
-    unsigned __r = 0;
-    if (!__c(*__y, *__x))          // if x <= y
-    {
-        if (!__c(*__z, *__y))      // if y <= z
-            return __r;            // x <= y && y <= z
-                                   // x <= y && y > z
-        swap(*__y, *__z);          // x <= z && y < z
-        __r = 1;
-        if (__c(*__y, *__x))       // if x > y
-        {
-            swap(*__x, *__y);      // x < y && y <= z
-            __r = 2;
-        }
-        return __r;                // x <= y && y < z
-    }
-    if (__c(*__z, *__y))           // x > y, if y > z
-    {
-        swap(*__x, *__z);          // x < y && y < z
-        __r = 1;
-        return __r;
-    }
-    swap(*__x, *__y);              // x > y && y <= z
-    __r = 1;                       // x < y && x <= z
-    if (__c(*__z, *__y))           // if y > z
-    {
-        swap(*__y, *__z);          // x <= y && y < z
-        __r = 2;
-    }
-    return __r;
-}                                  // x <= y && y <= z
-
-// stable, 3-6 compares, 0-5 swaps
-
-template <class _Compare, class _ForwardIterator>
-unsigned
-__sort4(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
-            _ForwardIterator __x4, _Compare __c)
-{
-    unsigned __r = __sort3<_Compare>(__x1, __x2, __x3, __c);
-    if (__c(*__x4, *__x3))
-    {
-        swap(*__x3, *__x4);
-        ++__r;
-        if (__c(*__x3, *__x2))
-        {
-            swap(*__x2, *__x3);
-            ++__r;
-            if (__c(*__x2, *__x1))
-            {
-                swap(*__x1, *__x2);
-                ++__r;
-            }
-        }
-    }
-    return __r;
-}
-
-// stable, 4-10 compares, 0-9 swaps
-
-template <class _Compare, class _ForwardIterator>
-_LIBCPP_HIDDEN
-unsigned
-__sort5(_ForwardIterator __x1, _ForwardIterator __x2, _ForwardIterator __x3,
-            _ForwardIterator __x4, _ForwardIterator __x5, _Compare __c)
-{
-    unsigned __r = __sort4<_Compare>(__x1, __x2, __x3, __x4, __c);
-    if (__c(*__x5, *__x4))
-    {
-        swap(*__x4, *__x5);
-        ++__r;
-        if (__c(*__x4, *__x3))
-        {
-            swap(*__x3, *__x4);
-            ++__r;
-            if (__c(*__x3, *__x2))
-            {
-                swap(*__x2, *__x3);
-                ++__r;
-                if (__c(*__x2, *__x1))
-                {
-                    swap(*__x1, *__x2);
-                    ++__r;
-                }
-            }
-        }
-    }
-    return __r;
-}
-
-// Assumes size > 0
-template <class _Compare, class _BirdirectionalIterator>
-void
-__selection_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
-{
-    _BirdirectionalIterator __lm1 = __last;
-    for (--__lm1; __first != __lm1; ++__first)
-    {
-        _BirdirectionalIterator __i = _VSTD::min_element<_BirdirectionalIterator,
-                                                        typename add_lvalue_reference<_Compare>::type>
-                                                       (__first, __last, __comp);
-        if (__i != __first)
-            swap(*__first, *__i);
-    }
-}
-
-template <class _Compare, class _BirdirectionalIterator>
-void
-__insertion_sort(_BirdirectionalIterator __first, _BirdirectionalIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
-    if (__first != __last)
-    {
-        _BirdirectionalIterator __i = __first;
-        for (++__i; __i != __last; ++__i)
-        {
-            _BirdirectionalIterator __j = __i;
-            value_type __t(_VSTD::move(*__j));
-            for (_BirdirectionalIterator __k = __i; __k != __first && __comp(__t,  *--__k); --__j)
-                *__j = _VSTD::move(*__k);
-            *__j = _VSTD::move(__t);
-        }
-    }
-}
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__insertion_sort_3(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    _RandomAccessIterator __j = __first+2;
-    __sort3<_Compare>(__first, __first+1, __j, __comp);
-    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
-    {
-        if (__comp(*__i, *__j))
-        {
-            value_type __t(_VSTD::move(*__i));
-            _RandomAccessIterator __k = __j;
-            __j = __i;
-            do
-            {
-                *__j = _VSTD::move(*__k);
-                __j = __k;
-            } while (__j != __first && __comp(__t, *--__k));
-            *__j = _VSTD::move(__t);
-        }
-        __j = __i;
-    }
-}
-
-template <class _Compare, class _RandomAccessIterator>
-bool
-__insertion_sort_incomplete(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    switch (__last - __first)
-    {
-    case 0:
-    case 1:
-        return true;
-    case 2:
-        if (__comp(*--__last, *__first))
-            swap(*__first, *__last);
-        return true;
-    case 3:
-        _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
-        return true;
-    case 4:
-        _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
-        return true;
-    case 5:
-        _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
-        return true;
-    }
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    _RandomAccessIterator __j = __first+2;
-    __sort3<_Compare>(__first, __first+1, __j, __comp);
-    const unsigned __limit = 8;
-    unsigned __count = 0;
-    for (_RandomAccessIterator __i = __j+1; __i != __last; ++__i)
-    {
-        if (__comp(*__i, *__j))
-        {
-            value_type __t(_VSTD::move(*__i));
-            _RandomAccessIterator __k = __j;
-            __j = __i;
-            do
-            {
-                *__j = _VSTD::move(*__k);
-                __j = __k;
-            } while (__j != __first && __comp(__t, *--__k));
-            *__j = _VSTD::move(__t);
-            if (++__count == __limit)
-                return ++__i == __last;
-        }
-        __j = __i;
-    }
-    return true;
-}
-
-template <class _Compare, class _BirdirectionalIterator>
-void
-__insertion_sort_move(_BirdirectionalIterator __first1, _BirdirectionalIterator __last1,
-                      typename iterator_traits<_BirdirectionalIterator>::value_type* __first2, _Compare __comp)
-{
-    typedef typename iterator_traits<_BirdirectionalIterator>::value_type value_type;
-    if (__first1 != __last1)
-    {
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h(__first2, __d);
-        value_type* __last2 = __first2;
-        ::new(__last2) value_type(_VSTD::move(*__first1));
-        __d.__incr((value_type*)0);
-        for (++__last2; ++__first1 != __last1; ++__last2)
-        {
-            value_type* __j2 = __last2;
-            value_type* __i2 = __j2;
-            if (__comp(*__first1, *--__i2))
-            {
-                ::new(__j2) value_type(_VSTD::move(*__i2));
-                __d.__incr((value_type*)0);
-                for (--__j2; __i2 != __first2 && __comp(*__first1,  *--__i2); --__j2)
-                    *__j2 = _VSTD::move(*__i2);
-                *__j2 = _VSTD::move(*__first1);
-            }
-            else
-            {
-                ::new(__j2) value_type(_VSTD::move(*__first1));
-                __d.__incr((value_type*)0);
-            }
-        }
-        __h.release();
-    }
-}
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    // _Compare is known to be a reference type
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    const difference_type __limit = is_trivially_copy_constructible<value_type>::value &&
-                                    is_trivially_copy_assignable<value_type>::value ? 30 : 6;
-    while (true)
-    {
-    __restart:
-        difference_type __len = __last - __first;
-        switch (__len)
-        {
-        case 0:
-        case 1:
-            return;
-        case 2:
-            if (__comp(*--__last, *__first))
-                swap(*__first, *__last);
-            return;
-        case 3:
-            _VSTD::__sort3<_Compare>(__first, __first+1, --__last, __comp);
-            return;
-        case 4:
-            _VSTD::__sort4<_Compare>(__first, __first+1, __first+2, --__last, __comp);
-            return;
-        case 5:
-            _VSTD::__sort5<_Compare>(__first, __first+1, __first+2, __first+3, --__last, __comp);
-            return;
-        }
-        if (__len <= __limit)
-        {
-            _VSTD::__insertion_sort_3<_Compare>(__first, __last, __comp);
-            return;
-        }
-        // __len > 5
-        _RandomAccessIterator __m = __first;
-        _RandomAccessIterator __lm1 = __last;
-        --__lm1;
-        unsigned __n_swaps;
-        {
-        difference_type __delta;
-        if (__len >= 1000)
-        {
-            __delta = __len/2;
-            __m += __delta;
-            __delta /= 2;
-            __n_swaps = _VSTD::__sort5<_Compare>(__first, __first + __delta, __m, __m+__delta, __lm1, __comp);
-        }
-        else
-        {
-            __delta = __len/2;
-            __m += __delta;
-            __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, __lm1, __comp);
-        }
-        }
-        // *__m is median
-        // partition [__first, __m) < *__m and *__m <= [__m, __last)
-        // (this inhibits tossing elements equivalent to __m around unnecessarily)
-        _RandomAccessIterator __i = __first;
-        _RandomAccessIterator __j = __lm1;
-        // j points beyond range to be tested, *__m is known to be <= *__lm1
-        // The search going up is known to be guarded but the search coming down isn't.
-        // Prime the downward search with a guard.
-        if (!__comp(*__i, *__m))  // if *__first == *__m
-        {
-            // *__first == *__m, *__first doesn't go in first part
-            // manually guard downward moving __j against __i
-            while (true)
-            {
-                if (__i == --__j)
-                {
-                    // *__first == *__m, *__m <= all other elements
-                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
-                    ++__i;  // __first + 1
-                    __j = __last;
-                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
-                    {
-                        while (true)
-                        {
-                            if (__i == __j)
-                                return;  // [__first, __last) all equivalent elements
-                            if (__comp(*__first, *__i))
-                            {
-                                swap(*__i, *__j);
-                                ++__n_swaps;
-                                ++__i;
-                                break;
-                            }
-                            ++__i;
-                        }
-                    }
-                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
-                    if (__i == __j)
-                        return;
-                    while (true)
-                    {
-                        while (!__comp(*__first, *__i))
-                            ++__i;
-                        while (__comp(*__first, *--__j))
-                            ;
-                        if (__i >= __j)
-                            break;
-                        swap(*__i, *__j);
-                        ++__n_swaps;
-                        ++__i;
-                    }
-                    // [__first, __i) == *__first and *__first < [__i, __last)
-                    // The first part is sorted, sort the secod part
-                    // _VSTD::__sort<_Compare>(__i, __last, __comp);
-                    __first = __i;
-                    goto __restart;
-                }
-                if (__comp(*__j, *__m))
-                {
-                    swap(*__i, *__j);
-                    ++__n_swaps;
-                    break;  // found guard for downward moving __j, now use unguarded partition
-                }
-            }
-        }
-        // It is known that *__i < *__m
-        ++__i;
-        // j points beyond range to be tested, *__m is known to be <= *__lm1
-        // if not yet partitioned...
-        if (__i < __j)
-        {
-            // known that *(__i - 1) < *__m
-            // known that __i <= __m
-            while (true)
-            {
-                // __m still guards upward moving __i
-                while (__comp(*__i, *__m))
-                    ++__i;
-                // It is now known that a guard exists for downward moving __j
-                while (!__comp(*--__j, *__m))
-                    ;
-                if (__i > __j)
-                    break;
-                swap(*__i, *__j);
-                ++__n_swaps;
-                // It is known that __m != __j
-                // If __m just moved, follow it
-                if (__m == __i)
-                    __m = __j;
-                ++__i;
-            }
-        }
-        // [__first, __i) < *__m and *__m <= [__i, __last)
-        if (__i != __m && __comp(*__m, *__i))
-        {
-            swap(*__i, *__m);
-            ++__n_swaps;
-        }
-        // [__first, __i) < *__i and *__i <= [__i+1, __last)
-        // If we were given a perfect partition, see if insertion sort is quick...
-        if (__n_swaps == 0)
-        {
-            bool __fs = _VSTD::__insertion_sort_incomplete<_Compare>(__first, __i, __comp);
-            if (_VSTD::__insertion_sort_incomplete<_Compare>(__i+1, __last, __comp))
-            {
-                if (__fs)
-                    return;
-                __last = __i;
-                continue;
-            }
-            else
-            {
-                if (__fs)
-                {
-                    __first = ++__i;
-                    continue;
-                }
-            }
-        }
-        // sort smaller range with recursive call and larger with tail recursion elimination
-        if (__i - __first < __last - __i)
-        {
-            _VSTD::__sort<_Compare>(__first, __i, __comp);
-            // _VSTD::__sort<_Compare>(__i+1, __last, __comp);
-            __first = ++__i;
-        }
-        else
-        {
-            _VSTD::__sort<_Compare>(__i+1, __last, __comp);
-            // _VSTD::__sort<_Compare>(__first, __i, __comp);
-            __last = __i;
-        }
-    }
-}
-
-// This forwarder keeps the top call and the recursive calls using the same instantiation, forcing a reference _Compare
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __sort<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __sort<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(_Tp** __first, _Tp** __last)
-{
-    _VSTD::sort((size_t*)__first, (size_t*)__last, __less<size_t>());
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last)
-{
-    _VSTD::sort(__first.base(), __last.base());
-}
-
-template <class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort(__wrap_iter<_Tp*> __first, __wrap_iter<_Tp*> __last, _Compare __comp)
-{
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    _VSTD::sort<_Tp*, _Comp_ref>(__first.base(), __last.base(), __comp);
-}
-
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<char>&, char*>(char*, char*, __less<char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<short>&, short*>(short*, short*, __less<short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<int>&, int*>(int*, int*, __less<int>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long>&, long*>(long*, long*, __less<long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<float>&, float*>(float*, float*, __less<float>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<double>&, double*>(double*, double*, __less<double>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void __sort<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
-
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<char>&, char*>(char*, char*, __less<char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<wchar_t>&, wchar_t*>(wchar_t*, wchar_t*, __less<wchar_t>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<signed char>&, signed char*>(signed char*, signed char*, __less<signed char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned char>&, unsigned char*>(unsigned char*, unsigned char*, __less<unsigned char>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<short>&, short*>(short*, short*, __less<short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned short>&, unsigned short*>(unsigned short*, unsigned short*, __less<unsigned short>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<int>&, int*>(int*, int*, __less<int>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned>&, unsigned*>(unsigned*, unsigned*, __less<unsigned>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long>&, long*>(long*, long*, __less<long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long>&, unsigned long*>(unsigned long*, unsigned long*, __less<unsigned long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long long>&, long long*>(long long*, long long*, __less<long long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<unsigned long long>&, unsigned long long*>(unsigned long long*, unsigned long long*, __less<unsigned long long>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<float>&, float*>(float*, float*, __less<float>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<double>&, double*>(double*, double*, __less<double>&))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS bool __insertion_sort_incomplete<__less<long double>&, long double*>(long double*, long double*, __less<long double>&))
-
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS unsigned __sort5<__less<long double>&, long double*>(long double*, long double*, long double*, long double*, long double*, __less<long double>&))
-
-// lower_bound
-
-template <class _Compare, class _ForwardIterator, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    while (__len != 0)
-    {
-        difference_type __l2 = _VSTD::__half_positive(__len);
-        _ForwardIterator __m = __first;
-        _VSTD::advance(__m, __l2);
-        if (__comp(*__m, __value_))
-        {
-            __first = ++__m;
-            __len -= __l2 + 1;
-        }
-        else
-            __len = __l2;
-    }
-    return __first;
-}
-
-template <class _ForwardIterator, class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __lower_bound<_Comp_ref>(__first, __last, __value_, __comp);
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-lower_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    return _VSTD::lower_bound(__first, __last, __value_,
-                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
-}
-
-// upper_bound
-
-template <class _Compare, class _ForwardIterator, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
-__upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    while (__len != 0)
-    {
-        difference_type __l2 = _VSTD::__half_positive(__len);
-        _ForwardIterator __m = __first;
-        _VSTD::advance(__m, __l2);
-        if (__comp(__value_, *__m))
-            __len = __l2;
-        else
-        {
-            __first = ++__m;
-            __len -= __l2 + 1;
-        }
-    }
-    return __first;
-}
-
-template <class _ForwardIterator, class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __upper_bound<_Comp_ref>(__first, __last, __value_, __comp);
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_ForwardIterator
-upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    return _VSTD::upper_bound(__first, __last, __value_,
-                             __less<_Tp, typename iterator_traits<_ForwardIterator>::value_type>());
-}
-
-// equal_range
-
-template <class _Compare, class _ForwardIterator, class _Tp>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 pair<_ForwardIterator, _ForwardIterator>
-__equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
-    difference_type __len = _VSTD::distance(__first, __last);
-    while (__len != 0)
-    {
-        difference_type __l2 = _VSTD::__half_positive(__len);
-        _ForwardIterator __m = __first;
-        _VSTD::advance(__m, __l2);
-        if (__comp(*__m, __value_))
-        {
-            __first = ++__m;
-            __len -= __l2 + 1;
-        }
-        else if (__comp(__value_, *__m))
-        {
-            __last = __m;
-            __len = __l2;
-        }
-        else
-        {
-            _ForwardIterator __mp1 = __m;
-            return pair<_ForwardIterator, _ForwardIterator>
-                   (
-                      __lower_bound<_Compare>(__first, __m, __value_, __comp),
-                      __upper_bound<_Compare>(++__mp1, __last, __value_, __comp)
-                   );
-        }
-    }
-    return pair<_ForwardIterator, _ForwardIterator>(__first, __first);
-}
-
-template <class _ForwardIterator, class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_ForwardIterator, _ForwardIterator>
-equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __equal_range<_Comp_ref>(__first, __last, __value_, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __equal_range<_Comp_ref>(__first, __last, __value_, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-pair<_ForwardIterator, _ForwardIterator>
-equal_range(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    return _VSTD::equal_range(__first, __last, __value_,
-                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
-}
-
-// binary_search
-
-template <class _Compare, class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-__binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-    __first = __lower_bound<_Compare>(__first, __last, __value_, __comp);
-    return __first != __last && !__comp(__value_, *__first);
-}
-
-template <class _ForwardIterator, class _Tp, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __binary_search<_Comp_ref>(__first, __last, __value_, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __binary_search<_Comp_ref>(__first, __last, __value_, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
-{
-    return _VSTD::binary_search(__first, __last, __value_,
-                             __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
-}
-
-// merge
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_OutputIterator
-__merge(_InputIterator1 __first1, _InputIterator1 __last1,
-        _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    for (; __first1 != __last1; ++__result)
-    {
-        if (__first2 == __last2)
-            return _VSTD::copy(__first1, __last1, __result);
-        if (__comp(*__first2, *__first1))
-        {
-            *__result = *__first2;
-            ++__first2;
-        }
-        else
-        {
-            *__result = *__first1;
-            ++__first1;
-        }
-    }
-    return _VSTD::copy(__first2, __last2, __result);
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-merge(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return _VSTD::__merge<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-merge(_InputIterator1 __first1, _InputIterator1 __last1,
-      _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-    typedef typename iterator_traits<_InputIterator2>::value_type __v2;
-    return merge(__first1, __last1, __first2, __last2, __result, __less<__v1, __v2>());
-}
-
-// inplace_merge
-
-template <class _Compare, class _InputIterator1, class _InputIterator2,
-          class _OutputIterator>
-void __half_inplace_merge(_InputIterator1 __first1, _InputIterator1 __last1,
-                          _InputIterator2 __first2, _InputIterator2 __last2,
-                          _OutputIterator __result, _Compare __comp)
-{
-    for (; __first1 != __last1; ++__result)
-    {
-        if (__first2 == __last2)
-        {
-            _VSTD::move(__first1, __last1, __result);
-            return;
-        }
-
-        if (__comp(*__first2, *__first1))
-        {
-            *__result = _VSTD::move(*__first2);
-            ++__first2;
-        }
-        else
-        {
-            *__result = _VSTD::move(*__first1);
-            ++__first1;
-        }
-    }
-    // __first2 through __last2 are already in the right spot.
-}
-
-template <class _Compare, class _BidirectionalIterator>
-void
-__buffered_inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
-                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
-                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
-                typename iterator_traits<_BidirectionalIterator>::value_type* __buff)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    __destruct_n __d(0);
-    unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
-    if (__len1 <= __len2)
-    {
-        value_type* __p = __buff;
-        for (_BidirectionalIterator __i = __first; __i != __middle; __d.__incr((value_type*)0), (void) ++__i, ++__p)
-            ::new(__p) value_type(_VSTD::move(*__i));
-        __half_inplace_merge(__buff, __p, __middle, __last, __first, __comp);
-    }
-    else
-    {
-        value_type* __p = __buff;
-        for (_BidirectionalIterator __i = __middle; __i != __last; __d.__incr((value_type*)0), (void) ++__i, ++__p)
-            ::new(__p) value_type(_VSTD::move(*__i));
-        typedef reverse_iterator<_BidirectionalIterator> _RBi;
-        typedef reverse_iterator<value_type*> _Rv;
-        __half_inplace_merge(_Rv(__p), _Rv(__buff),
-                             _RBi(__middle), _RBi(__first),
-                             _RBi(__last), __invert<_Compare>(__comp));
-    }
-}
-
-template <class _Compare, class _BidirectionalIterator>
-void
-__inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
-                _Compare __comp, typename iterator_traits<_BidirectionalIterator>::difference_type __len1,
-                                 typename iterator_traits<_BidirectionalIterator>::difference_type __len2,
-                typename iterator_traits<_BidirectionalIterator>::value_type* __buff, ptrdiff_t __buff_size)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
-    while (true)
-    {
-        // if __middle == __last, we're done
-        if (__len2 == 0)
-            return;
-        if (__len1 <= __buff_size || __len2 <= __buff_size)
-            return __buffered_inplace_merge<_Compare>
-                   (__first, __middle, __last, __comp, __len1, __len2, __buff);
-        // shrink [__first, __middle) as much as possible (with no moves), returning if it shrinks to 0
-        for (; true; ++__first, (void) --__len1)
-        {
-            if (__len1 == 0)
-                return;
-            if (__comp(*__middle, *__first))
-                break;
-        }
-        // __first < __middle < __last
-        // *__first > *__middle
-        // partition [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last) such that
-        //     all elements in:
-        //         [__first, __m1)  <= [__middle, __m2)
-        //         [__middle, __m2) <  [__m1, __middle)
-        //         [__m1, __middle) <= [__m2, __last)
-        //     and __m1 or __m2 is in the middle of its range
-        _BidirectionalIterator __m1;  // "median" of [__first, __middle)
-        _BidirectionalIterator __m2;  // "median" of [__middle, __last)
-        difference_type __len11;      // distance(__first, __m1)
-        difference_type __len21;      // distance(__middle, __m2)
-        // binary search smaller range
-        if (__len1 < __len2)
-        {   // __len >= 1, __len2 >= 2
-            __len21 = __len2 / 2;
-            __m2 = __middle;
-            _VSTD::advance(__m2, __len21);
-            __m1 = __upper_bound<_Compare>(__first, __middle, *__m2, __comp);
-            __len11 = _VSTD::distance(__first, __m1);
-        }
-        else
-        {
-            if (__len1 == 1)
-            {   // __len1 >= __len2 && __len2 > 0, therefore __len2 == 1
-                // It is known *__first > *__middle
-                swap(*__first, *__middle);
-                return;
-            }
-            // __len1 >= 2, __len2 >= 1
-            __len11 = __len1 / 2;
-            __m1 = __first;
-            _VSTD::advance(__m1, __len11);
-            __m2 = __lower_bound<_Compare>(__middle, __last, *__m1, __comp);
-            __len21 = _VSTD::distance(__middle, __m2);
-        }
-        difference_type __len12 = __len1 - __len11;  // distance(__m1, __middle)
-        difference_type __len22 = __len2 - __len21;  // distance(__m2, __last)
-        // [__first, __m1) [__m1, __middle) [__middle, __m2) [__m2, __last)
-        // swap middle two partitions
-        __middle = _VSTD::rotate(__m1, __middle, __m2);
-        // __len12 and __len21 now have swapped meanings
-        // merge smaller range with recurisve call and larger with tail recursion elimination
-        if (__len11 + __len21 < __len12 + __len22)
-        {
-            __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
-//          __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
-            __first = __middle;
-            __middle = __m2;
-            __len1 = __len12;
-            __len2 = __len22;
-        }
-        else
-        {
-            __inplace_merge<_Compare>(__middle, __m2, __last, __comp, __len12, __len22, __buff, __buff_size);
-//          __inplace_merge<_Compare>(__first, __m1, __middle, __comp, __len11, __len21, __buff, __buff_size);
-            __last = __middle;
-            __middle = __m1;
-            __len1 = __len11;
-            __len2 = __len21;
-        }
-    }
-}
-
-template <class _BidirectionalIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last,
-              _Compare __comp)
-{
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type value_type;
-    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
-    difference_type __len1 = _VSTD::distance(__first, __middle);
-    difference_type __len2 = _VSTD::distance(__middle, __last);
-    difference_type __buf_size = _VSTD::min(__len1, __len2);
-    pair<value_type*, ptrdiff_t> __buf = _VSTD::get_temporary_buffer<value_type>(__buf_size);
-    unique_ptr<value_type, __return_temporary_buffer> __h(__buf.first);
-
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __c, __len1, __len2,
-                                            __buf.first, __buf.second);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return _VSTD::__inplace_merge<_Comp_ref>(__first, __middle, __last, __comp, __len1, __len2,
-                                            __buf.first, __buf.second);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-inplace_merge(_BidirectionalIterator __first, _BidirectionalIterator __middle, _BidirectionalIterator __last)
-{
-    _VSTD::inplace_merge(__first, __middle, __last,
-                        __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
-}
-
-// stable_sort
-
-template <class _Compare, class _InputIterator1, class _InputIterator2>
-void
-__merge_move_construct(_InputIterator1 __first1, _InputIterator1 __last1,
-        _InputIterator2 __first2, _InputIterator2 __last2,
-        typename iterator_traits<_InputIterator1>::value_type* __result, _Compare __comp)
-{
-    typedef typename iterator_traits<_InputIterator1>::value_type value_type;
-    __destruct_n __d(0);
-    unique_ptr<value_type, __destruct_n&> __h(__result, __d);
-    for (; true; ++__result)
-    {
-        if (__first1 == __last1)
-        {
-            for (; __first2 != __last2; ++__first2, ++__result, __d.__incr((value_type*)0))
-                ::new (__result) value_type(_VSTD::move(*__first2));
-            __h.release();
-            return;
-        }
-        if (__first2 == __last2)
-        {
-            for (; __first1 != __last1; ++__first1, ++__result, __d.__incr((value_type*)0))
-                ::new (__result) value_type(_VSTD::move(*__first1));
-            __h.release();
-            return;
-        }
-        if (__comp(*__first2, *__first1))
-        {
-            ::new (__result) value_type(_VSTD::move(*__first2));
-            __d.__incr((value_type*)0);
-            ++__first2;
-        }
-        else
-        {
-            ::new (__result) value_type(_VSTD::move(*__first1));
-            __d.__incr((value_type*)0);
-            ++__first1;
-        }
-    }
-}
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-void
-__merge_move_assign(_InputIterator1 __first1, _InputIterator1 __last1,
-        _InputIterator2 __first2, _InputIterator2 __last2,
-        _OutputIterator __result, _Compare __comp)
-{
-    for (; __first1 != __last1; ++__result)
-    {
-        if (__first2 == __last2)
-        {
-            for (; __first1 != __last1; ++__first1, ++__result)
-                *__result = _VSTD::move(*__first1);
-            return;
-        }
-        if (__comp(*__first2, *__first1))
-        {
-            *__result = _VSTD::move(*__first2);
-            ++__first2;
-        }
-        else
-        {
-            *__result = _VSTD::move(*__first1);
-            ++__first1;
-        }
-    }
-    for (; __first2 != __last2; ++__first2, ++__result)
-        *__result = _VSTD::move(*__first2);
-}
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
-              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
-              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size);
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__stable_sort_move(_RandomAccessIterator __first1, _RandomAccessIterator __last1, _Compare __comp,
-                   typename iterator_traits<_RandomAccessIterator>::difference_type __len,
-                   typename iterator_traits<_RandomAccessIterator>::value_type* __first2)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    switch (__len)
-    {
-    case 0:
-        return;
-    case 1:
-        ::new(__first2) value_type(_VSTD::move(*__first1));
-        return;
-    case 2:
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h2(__first2, __d);
-        if (__comp(*--__last1, *__first1))
-        {
-            ::new(__first2) value_type(_VSTD::move(*__last1));
-            __d.__incr((value_type*)0);
-            ++__first2;
-            ::new(__first2) value_type(_VSTD::move(*__first1));
-        }
-        else
-        {
-            ::new(__first2) value_type(_VSTD::move(*__first1));
-            __d.__incr((value_type*)0);
-            ++__first2;
-            ::new(__first2) value_type(_VSTD::move(*__last1));
-        }
-        __h2.release();
-        return;
-    }
-    if (__len <= 8)
-    {
-        __insertion_sort_move<_Compare>(__first1, __last1, __first2, __comp);
-        return;
-    }
-    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
-    _RandomAccessIterator __m = __first1 + __l2;
-    __stable_sort<_Compare>(__first1, __m, __comp, __l2, __first2, __l2);
-    __stable_sort<_Compare>(__m, __last1, __comp, __len - __l2, __first2 + __l2, __len - __l2);
-    __merge_move_construct<_Compare>(__first1, __m, __m, __last1, __first2, __comp);
-}
-
-template <class _Tp>
-struct __stable_sort_switch
-{
-    static const unsigned value = 128*is_trivially_copy_assignable<_Tp>::value;
-};
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
-              typename iterator_traits<_RandomAccessIterator>::difference_type __len,
-              typename iterator_traits<_RandomAccessIterator>::value_type* __buff, ptrdiff_t __buff_size)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    switch (__len)
-    {
-    case 0:
-    case 1:
-        return;
-    case 2:
-        if (__comp(*--__last, *__first))
-            swap(*__first, *__last);
-        return;
-    }
-    if (__len <= static_cast<difference_type>(__stable_sort_switch<value_type>::value))
-    {
-        __insertion_sort<_Compare>(__first, __last, __comp);
-        return;
-    }
-    typename iterator_traits<_RandomAccessIterator>::difference_type __l2 = __len / 2;
-    _RandomAccessIterator __m = __first + __l2;
-    if (__len <= __buff_size)
-    {
-        __destruct_n __d(0);
-        unique_ptr<value_type, __destruct_n&> __h2(__buff, __d);
-        __stable_sort_move<_Compare>(__first, __m, __comp, __l2, __buff);
-        __d.__set(__l2, (value_type*)0);
-        __stable_sort_move<_Compare>(__m, __last, __comp, __len - __l2, __buff + __l2);
-        __d.__set(__len, (value_type*)0);
-        __merge_move_assign<_Compare>(__buff, __buff + __l2, __buff + __l2, __buff + __len, __first, __comp);
-//         __merge<_Compare>(move_iterator<value_type*>(__buff),
-//                           move_iterator<value_type*>(__buff + __l2),
-//                           move_iterator<_RandomAccessIterator>(__buff + __l2),
-//                           move_iterator<_RandomAccessIterator>(__buff + __len),
-//                           __first, __comp);
-        return;
-    }
-    __stable_sort<_Compare>(__first, __m, __comp, __l2, __buff, __buff_size);
-    __stable_sort<_Compare>(__m, __last, __comp, __len - __l2, __buff, __buff_size);
-    __inplace_merge<_Compare>(__first, __m, __last, __comp, __l2, __len - __l2, __buff, __buff_size);
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    difference_type __len = __last - __first;
-    pair<value_type*, ptrdiff_t> __buf(0, 0);
-    unique_ptr<value_type, __return_temporary_buffer> __h;
-    if (__len > static_cast<difference_type>(__stable_sort_switch<value_type>::value))
-    {
-        __buf = _VSTD::get_temporary_buffer<value_type>(__len);
-        __h.reset(__buf.first);
-    }
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __stable_sort<_Comp_ref>(__first, __last, __c, __len, __buf.first, __buf.second);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __stable_sort<_Comp_ref>(__first, __last, __comp, __len, __buf.first, __buf.second);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-stable_sort(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::stable_sort(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// is_heap_until
-
-template <class _RandomAccessIterator, class _Compare>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _RandomAccessIterator
-is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename _VSTD::iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    difference_type __len = __last - __first;
-    difference_type __p = 0;
-    difference_type __c = 1;
-    _RandomAccessIterator __pp = __first;
-    while (__c < __len)
-    {
-        _RandomAccessIterator __cp = __first + __c;
-        if (__comp(*__pp, *__cp))
-            return __cp;
-        ++__c;
-        ++__cp;
-        if (__c == __len)
-            return __last;
-        if (__comp(*__pp, *__cp))
-            return __cp;
-        ++__p;
-        ++__pp;
-        __c = 2 * __p + 1;
-    }
-    return __last;
-}
-
-template<class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_RandomAccessIterator
-is_heap_until(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    return _VSTD::is_heap_until(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// is_heap
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    return _VSTD::is_heap_until(__first, __last, __comp) == __last;
-}
-
-template<class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-is_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    return _VSTD::is_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// push_heap
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__sift_up(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
-          typename iterator_traits<_RandomAccessIterator>::difference_type __len)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    if (__len > 1)
-    {
-        __len = (__len - 2) / 2;
-        _RandomAccessIterator __ptr = __first + __len;
-        if (__comp(*__ptr, *--__last))
-        {
-            value_type __t(_VSTD::move(*__last));
-            do
-            {
-                *__last = _VSTD::move(*__ptr);
-                __last = __ptr;
-                if (__len == 0)
-                    break;
-                __len = (__len - 1) / 2;
-                __ptr = __first + __len;
-            } while (__comp(*__ptr, __t));
-            *__last = _VSTD::move(__t);
-        }
-    }
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __sift_up<_Comp_ref>(__first, __last, __c, __last - __first);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __sift_up<_Comp_ref>(__first, __last, __comp, __last - __first);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-push_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::push_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// pop_heap
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__sift_down(_RandomAccessIterator __first, _RandomAccessIterator /*__last*/,
-            _Compare __comp,
-            typename iterator_traits<_RandomAccessIterator>::difference_type __len,
-            _RandomAccessIterator __start)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    typedef typename iterator_traits<_RandomAccessIterator>::value_type value_type;
-    // left-child of __start is at 2 * __start + 1
-    // right-child of __start is at 2 * __start + 2
-    difference_type __child = __start - __first;
-
-    if (__len < 2 || (__len - 2) / 2 < __child)
-        return;
-
-    __child = 2 * __child + 1;
-    _RandomAccessIterator __child_i = __first + __child;
-
-    if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
-        // right-child exists and is greater than left-child
-        ++__child_i;
-        ++__child;
-    }
-
-    // check if we are in heap-order
-    if (__comp(*__child_i, *__start))
-        // we are, __start is larger than it's largest child
-        return;
-
-    value_type __top(_VSTD::move(*__start));
-    do
-    {
-        // we are not in heap-order, swap the parent with it's largest child
-        *__start = _VSTD::move(*__child_i);
-        __start = __child_i;
-
-        if ((__len - 2) / 2 < __child)
-            break;
-
-        // recompute the child based off of the updated parent
-        __child = 2 * __child + 1;
-        __child_i = __first + __child;
-
-        if ((__child + 1) < __len && __comp(*__child_i, *(__child_i + 1))) {
-            // right-child exists and is greater than left-child
-            ++__child_i;
-            ++__child;
-        }
-
-        // check if we are in heap-order
-    } while (!__comp(*__child_i, __top));
-    *__start = _VSTD::move(__top);
-}
-
-template <class _Compare, class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp,
-           typename iterator_traits<_RandomAccessIterator>::difference_type __len)
-{
-    if (__len > 1)
-    {
-        swap(*__first, *--__last);
-        __sift_down<_Compare>(__first, __last, __comp, __len - 1, __first);
-    }
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __pop_heap<_Comp_ref>(__first, __last, __c, __last - __first);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __pop_heap<_Comp_ref>(__first, __last, __comp, __last - __first);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-pop_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::pop_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// make_heap
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    difference_type __n = __last - __first;
-    if (__n > 1)
-    {
-        // start from the first parent, there is no need to consider children
-        for (difference_type __start = (__n - 2) / 2; __start >= 0; --__start)
-        {
-            __sift_down<_Compare>(__first, __last, __comp, __n, __first + __start);
-        }
-    }
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __make_heap<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __make_heap<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-make_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::make_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// sort_heap
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    for (difference_type __n = __last - __first; __n > 1; --__last, --__n)
-        __pop_heap<_Compare>(__first, __last, __comp, __n);
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __sort_heap<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __sort_heap<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sort_heap(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    _VSTD::sort_heap(__first, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// partial_sort
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
-             _Compare __comp)
-{
-    __make_heap<_Compare>(__first, __middle, __comp);
-    typename iterator_traits<_RandomAccessIterator>::difference_type __len = __middle - __first;
-    for (_RandomAccessIterator __i = __middle; __i != __last; ++__i)
-    {
-        if (__comp(*__i, *__first))
-        {
-            swap(*__i, *__first);
-            __sift_down<_Compare>(__first, __middle, __comp, __len, __first);
-        }
-    }
-    __sort_heap<_Compare>(__first, __middle, __comp);
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last,
-             _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __partial_sort<_Comp_ref>(__first, __middle, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __partial_sort<_Comp_ref>(__first, __middle, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-partial_sort(_RandomAccessIterator __first, _RandomAccessIterator __middle, _RandomAccessIterator __last)
-{
-    _VSTD::partial_sort(__first, __middle, __last,
-                       __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// partial_sort_copy
-
-template <class _Compare, class _InputIterator, class _RandomAccessIterator>
-_RandomAccessIterator
-__partial_sort_copy(_InputIterator __first, _InputIterator __last,
-                    _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
-{
-    _RandomAccessIterator __r = __result_first;
-    if (__r != __result_last)
-    {
-        for (; __first != __last && __r != __result_last; (void) ++__first, ++__r)
-            *__r = *__first;
-        __make_heap<_Compare>(__result_first, __r, __comp);
-        typename iterator_traits<_RandomAccessIterator>::difference_type __len = __r - __result_first;
-        for (; __first != __last; ++__first)
-            if (__comp(*__first, *__result_first))
-            {
-                *__result_first = *__first;
-                __sift_down<_Compare>(__result_first, __r, __comp, __len, __result_first);
-            }
-        __sort_heap<_Compare>(__result_first, __r, __comp);
-    }
-    return __r;
-}
-
-template <class _InputIterator, class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_RandomAccessIterator
-partial_sort_copy(_InputIterator __first, _InputIterator __last,
-                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __partial_sort_copy<_Comp_ref>(__first, __last, __result_first, __result_last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator, class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_RandomAccessIterator
-partial_sort_copy(_InputIterator __first, _InputIterator __last,
-                  _RandomAccessIterator __result_first, _RandomAccessIterator __result_last)
-{
-    return _VSTD::partial_sort_copy(__first, __last, __result_first, __result_last,
-                                   __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// nth_element
-
-template <class _Compare, class _RandomAccessIterator>
-void
-__nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
-{
-    // _Compare is known to be a reference type
-    typedef typename iterator_traits<_RandomAccessIterator>::difference_type difference_type;
-    const difference_type __limit = 7;
-    while (true)
-    {
-    __restart:
-        if (__nth == __last)
-            return;
-        difference_type __len = __last - __first;
-        switch (__len)
-        {
-        case 0:
-        case 1:
-            return;
-        case 2:
-            if (__comp(*--__last, *__first))
-                swap(*__first, *__last);
-            return;
-        case 3:
-            {
-            _RandomAccessIterator __m = __first;
-            _VSTD::__sort3<_Compare>(__first, ++__m, --__last, __comp);
-            return;
-            }
-        }
-        if (__len <= __limit)
-        {
-            __selection_sort<_Compare>(__first, __last, __comp);
-            return;
-        }
-        // __len > __limit >= 3
-        _RandomAccessIterator __m = __first + __len/2;
-        _RandomAccessIterator __lm1 = __last;
-        unsigned __n_swaps = _VSTD::__sort3<_Compare>(__first, __m, --__lm1, __comp);
-        // *__m is median
-        // partition [__first, __m) < *__m and *__m <= [__m, __last)
-        // (this inhibits tossing elements equivalent to __m around unnecessarily)
-        _RandomAccessIterator __i = __first;
-        _RandomAccessIterator __j = __lm1;
-        // j points beyond range to be tested, *__lm1 is known to be <= *__m
-        // The search going up is known to be guarded but the search coming down isn't.
-        // Prime the downward search with a guard.
-        if (!__comp(*__i, *__m))  // if *__first == *__m
-        {
-            // *__first == *__m, *__first doesn't go in first part
-            // manually guard downward moving __j against __i
-            while (true)
-            {
-                if (__i == --__j)
-                {
-                    // *__first == *__m, *__m <= all other elements
-                    // Parition instead into [__first, __i) == *__first and *__first < [__i, __last)
-                    ++__i;  // __first + 1
-                    __j = __last;
-                    if (!__comp(*__first, *--__j))  // we need a guard if *__first == *(__last-1)
-                    {
-                        while (true)
-                        {
-                            if (__i == __j)
-                                return;  // [__first, __last) all equivalent elements
-                            if (__comp(*__first, *__i))
-                            {
-                                swap(*__i, *__j);
-                                ++__n_swaps;
-                                ++__i;
-                                break;
-                            }
-                            ++__i;
-                        }
-                    }
-                    // [__first, __i) == *__first and *__first < [__j, __last) and __j == __last - 1
-                    if (__i == __j)
-                        return;
-                    while (true)
-                    {
-                        while (!__comp(*__first, *__i))
-                            ++__i;
-                        while (__comp(*__first, *--__j))
-                            ;
-                        if (__i >= __j)
-                            break;
-                        swap(*__i, *__j);
-                        ++__n_swaps;
-                        ++__i;
-                    }
-                    // [__first, __i) == *__first and *__first < [__i, __last)
-                    // The first part is sorted,
-                    if (__nth < __i)
-                        return;
-                    // __nth_element the secod part
-                    // __nth_element<_Compare>(__i, __nth, __last, __comp);
-                    __first = __i;
-                    goto __restart;
-                }
-                if (__comp(*__j, *__m))
-                {
-                    swap(*__i, *__j);
-                    ++__n_swaps;
-                    break;  // found guard for downward moving __j, now use unguarded partition
-                }
-            }
-        }
-        ++__i;
-        // j points beyond range to be tested, *__lm1 is known to be <= *__m
-        // if not yet partitioned...
-        if (__i < __j)
-        {
-            // known that *(__i - 1) < *__m
-            while (true)
-            {
-                // __m still guards upward moving __i
-                while (__comp(*__i, *__m))
-                    ++__i;
-                // It is now known that a guard exists for downward moving __j
-                while (!__comp(*--__j, *__m))
-                    ;
-                if (__i >= __j)
-                    break;
-                swap(*__i, *__j);
-                ++__n_swaps;
-                // It is known that __m != __j
-                // If __m just moved, follow it
-                if (__m == __i)
-                    __m = __j;
-                ++__i;
-            }
-        }
-        // [__first, __i) < *__m and *__m <= [__i, __last)
-        if (__i != __m && __comp(*__m, *__i))
-        {
-            swap(*__i, *__m);
-            ++__n_swaps;
-        }
-        // [__first, __i) < *__i and *__i <= [__i+1, __last)
-        if (__nth == __i)
-            return;
-        if (__n_swaps == 0)
-        {
-            // We were given a perfectly partitioned sequence.  Coincidence?
-            if (__nth < __i)
-            {
-                // Check for [__first, __i) already sorted
-                __j = __m = __first;
-                while (++__j != __i)
-                {
-                    if (__comp(*__j, *__m))
-                        // not yet sorted, so sort
-                        goto not_sorted;
-                    __m = __j;
-                }
-                // [__first, __i) sorted
-                return;
-            }
-            else
-            {
-                // Check for [__i, __last) already sorted
-                __j = __m = __i;
-                while (++__j != __last)
-                {
-                    if (__comp(*__j, *__m))
-                        // not yet sorted, so sort
-                        goto not_sorted;
-                    __m = __j;
-                }
-                // [__i, __last) sorted
-                return;
-            }
-        }
-not_sorted:
-        // __nth_element on range containing __nth
-        if (__nth < __i)
-        {
-            // __nth_element<_Compare>(__first, __nth, __i, __comp);
-            __last = __i;
-        }
-        else
-        {
-            // __nth_element<_Compare>(__i+1, __nth, __last, __comp);
-            __first = ++__i;
-        }
-    }
-}
-
-template <class _RandomAccessIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    __nth_element<_Comp_ref>(__first, __nth, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    __nth_element<_Comp_ref>(__first, __nth, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _RandomAccessIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-nth_element(_RandomAccessIterator __first, _RandomAccessIterator __nth, _RandomAccessIterator __last)
-{
-    _VSTD::nth_element(__first, __nth, __last, __less<typename iterator_traits<_RandomAccessIterator>::value_type>());
-}
-
-// includes
-
-template <class _Compare, class _InputIterator1, class _InputIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
-           _Compare __comp)
-{
-    for (; __first2 != __last2; ++__first1)
-    {
-        if (__first1 == __last1 || __comp(*__first2, *__first1))
-            return false;
-        if (!__comp(*__first1, *__first2))
-            ++__first2;
-    }
-    return true;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2,
-         _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __includes<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-includes(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    return _VSTD::includes(__first1, __last1, __first2, __last2,
-                          __less<typename iterator_traits<_InputIterator1>::value_type,
-                                 typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// set_union
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_OutputIterator
-__set_union(_InputIterator1 __first1, _InputIterator1 __last1,
-            _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    for (; __first1 != __last1; ++__result)
-    {
-        if (__first2 == __last2)
-            return _VSTD::copy(__first1, __last1, __result);
-        if (__comp(*__first2, *__first1))
-        {
-            *__result = *__first2;
-            ++__first2;
-        }
-        else
-        {
-            if (!__comp(*__first1, *__first2))
-                ++__first2;
-            *__result = *__first1;
-            ++__first1;
-        }
-    }
-    return _VSTD::copy(__first2, __last2, __result);
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_union(_InputIterator1 __first1, _InputIterator1 __last1,
-          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __set_union<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_union(_InputIterator1 __first1, _InputIterator1 __last1,
-          _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    return _VSTD::set_union(__first1, __last1, __first2, __last2, __result,
-                          __less<typename iterator_traits<_InputIterator1>::value_type,
-                                 typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// set_intersection
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 _OutputIterator
-__set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
-                   _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    while (__first1 != __last1 && __first2 != __last2)
-    {
-        if (__comp(*__first1, *__first2))
-            ++__first1;
-        else
-        {
-            if (!__comp(*__first2, *__first1))
-            {
-                *__result = *__first1;
-                ++__result;
-                ++__first1;
-            }
-            ++__first2;
-        }
-    }
-    return __result;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
-                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __set_intersection<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_OutputIterator
-set_intersection(_InputIterator1 __first1, _InputIterator1 __last1,
-                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    return _VSTD::set_intersection(__first1, __last1, __first2, __last2, __result,
-                                  __less<typename iterator_traits<_InputIterator1>::value_type,
-                                         typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// set_difference
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_OutputIterator
-__set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-                 _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    while (__first1 != __last1)
-    {
-        if (__first2 == __last2)
-            return _VSTD::copy(__first1, __last1, __result);
-        if (__comp(*__first1, *__first2))
-        {
-            *__result = *__first1;
-            ++__result;
-            ++__first1;
-        }
-        else
-        {
-            if (!__comp(*__first2, *__first1))
-                ++__first1;
-            ++__first2;
-        }
-    }
-    return __result;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __set_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-               _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    return _VSTD::set_difference(__first1, __last1, __first2, __last2, __result,
-                                __less<typename iterator_traits<_InputIterator1>::value_type,
-                                       typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// set_symmetric_difference
-
-template <class _Compare, class _InputIterator1, class _InputIterator2, class _OutputIterator>
-_OutputIterator
-__set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-                           _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-    while (__first1 != __last1)
-    {
-        if (__first2 == __last2)
-            return _VSTD::copy(__first1, __last1, __result);
-        if (__comp(*__first1, *__first2))
-        {
-            *__result = *__first1;
-            ++__result;
-            ++__first1;
-        }
-        else
-        {
-            if (__comp(*__first2, *__first1))
-            {
-                *__result = *__first2;
-                ++__result;
-            }
-            else
-                ++__first1;
-            ++__first2;
-        }
-    }
-    return _VSTD::copy(__first2, __last2, __result);
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __set_symmetric_difference<_Comp_ref>(__first1, __last1, __first2, __last2, __result, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-set_symmetric_difference(_InputIterator1 __first1, _InputIterator1 __last1,
-                         _InputIterator2 __first2, _InputIterator2 __last2, _OutputIterator __result)
-{
-    return _VSTD::set_symmetric_difference(__first1, __last1, __first2, __last2, __result,
-                                          __less<typename iterator_traits<_InputIterator1>::value_type,
-                                                 typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// lexicographical_compare
-
-template <class _Compare, class _InputIterator1, class _InputIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-__lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
-                          _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
-{
-    for (; __first2 != __last2; ++__first1, (void) ++__first2)
-    {
-        if (__first1 == __last1 || __comp(*__first1, *__first2))
-            return true;
-        if (__comp(*__first2, *__first1))
-            return false;
-    }
-    return false;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
-                        _InputIterator2 __first2, _InputIterator2 __last2, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __lexicographical_compare<_Comp_ref>(__first1, __last1, __first2, __last2, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _InputIterator1, class _InputIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-bool
-lexicographical_compare(_InputIterator1 __first1, _InputIterator1 __last1,
-                        _InputIterator2 __first2, _InputIterator2 __last2)
-{
-    return _VSTD::lexicographical_compare(__first1, __last1, __first2, __last2,
-                                         __less<typename iterator_traits<_InputIterator1>::value_type,
-                                                typename iterator_traits<_InputIterator2>::value_type>());
-}
-
-// next_permutation
-
-template <class _Compare, class _BidirectionalIterator>
-bool
-__next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-    _BidirectionalIterator __i = __last;
-    if (__first == __last || __first == --__i)
-        return false;
-    while (true)
-    {
-        _BidirectionalIterator __ip1 = __i;
-        if (__comp(*--__i, *__ip1))
-        {
-            _BidirectionalIterator __j = __last;
-            while (!__comp(*__i, *--__j))
-                ;
-            swap(*__i, *__j);
-            _VSTD::reverse(__ip1, __last);
-            return true;
-        }
-        if (__i == __first)
-        {
-            _VSTD::reverse(__first, __last);
-            return false;
-        }
-    }
-}
-
-template <class _BidirectionalIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __next_permutation<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __next_permutation<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-next_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
-{
-    return _VSTD::next_permutation(__first, __last,
-                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
-}
-
-// prev_permutation
-
-template <class _Compare, class _BidirectionalIterator>
-bool
-__prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-    _BidirectionalIterator __i = __last;
-    if (__first == __last || __first == --__i)
-        return false;
-    while (true)
-    {
-        _BidirectionalIterator __ip1 = __i;
-        if (__comp(*__ip1, *--__i))
-        {
-            _BidirectionalIterator __j = __last;
-            while (!__comp(*--__j, *__i))
-                ;
-            swap(*__i, *__j);
-            _VSTD::reverse(__ip1, __last);
-            return true;
-        }
-        if (__i == __first)
-        {
-            _VSTD::reverse(__first, __last);
-            return false;
-        }
-    }
-}
-
-template <class _BidirectionalIterator, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last, _Compare __comp)
-{
-#ifdef _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<__debug_less<_Compare> >::type _Comp_ref;
-    __debug_less<_Compare> __c(__comp);
-    return __prev_permutation<_Comp_ref>(__first, __last, __c);
-#else  // _LIBCPP_DEBUG
-    typedef typename add_lvalue_reference<_Compare>::type _Comp_ref;
-    return __prev_permutation<_Comp_ref>(__first, __last, __comp);
-#endif  // _LIBCPP_DEBUG
-}
-
-template <class _BidirectionalIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-prev_permutation(_BidirectionalIterator __first, _BidirectionalIterator __last)
-{
-    return _VSTD::prev_permutation(__first, __last,
-                                  __less<typename iterator_traits<_BidirectionalIterator>::value_type>());
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_ALGORITHM
diff --git a/lib/libcxx/include/any b/lib/libcxx/include/any
deleted file mode 100644
index 781eee7869c..00000000000
--- a/lib/libcxx/include/any
+++ /dev/null
@@ -1,672 +0,0 @@
-// -*- C++ -*-
-//===------------------------------ any -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_ANY
-#define _LIBCPP_ANY
-
-/*
-   any synopsis
-
-namespace std {
-
-  class bad_any_cast : public bad_cast
-  {
-  public:
-    virtual const char* what() const noexcept;
-  };
-
-  class any
-  {
-  public:
-
-    // 6.3.1 any construct/destruct
-    any() noexcept;
-
-    any(const any& other);
-    any(any&& other) noexcept;
-
-    template <class ValueType>
-      any(ValueType&& value);
-
-    ~any();
-
-    // 6.3.2 any assignments
-    any& operator=(const any& rhs);
-    any& operator=(any&& rhs) noexcept;
-
-    template <class ValueType>
-      any& operator=(ValueType&& rhs);
-
-    // 6.3.3 any modifiers
-    template <class ValueType, class... Args>
-      decay_t<ValueType>& emplace(Args&&... args);
-    template <class ValueType, class U, class... Args>
-      decay_t<ValueType>& emplace(initializer_list<U>, Args&&...);
-    void reset() noexcept;
-    void swap(any& rhs) noexcept;
-
-    // 6.3.4 any observers
-    bool has_value() const noexcept;
-    const type_info& type() const noexcept;
-  };
-
-   // 6.4 Non-member functions
-  void swap(any& x, any& y) noexcept;
-
-  template <class T, class ...Args>
-    any make_any(Args&& ...args);
-  template <class T, class U, class ...Args>
-    any make_any(initializer_list<U>, Args&& ...args);
-
-  template<class ValueType>
-    ValueType any_cast(const any& operand);
-  template<class ValueType>
-    ValueType any_cast(any& operand);
-  template<class ValueType>
-    ValueType any_cast(any&& operand);
-
-  template<class ValueType>
-    const ValueType* any_cast(const any* operand) noexcept;
-  template<class ValueType>
-    ValueType* any_cast(any* operand) noexcept;
-
-} // namespace std
-
-*/
-
-#include <experimental/__config>
-#include <memory>
-#include <new>
-#include <typeinfo>
-#include <type_traits>
-#include <cstdlib>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-namespace std {
-class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_ANY_CAST bad_any_cast : public bad_cast
-{
-public:
-    virtual const char* what() const _NOEXCEPT;
-};
-} // namespace std
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER > 14
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
-void __throw_bad_any_cast()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw bad_any_cast();
-#else
-    _VSTD::abort();
-#endif
-}
-
-// Forward declarations
-class _LIBCPP_TEMPLATE_VIS any;
-
-template <class _ValueType>
-_LIBCPP_INLINE_VISIBILITY
-add_pointer_t<add_const_t<_ValueType>>
-any_cast(any const *) _NOEXCEPT;
-
-template <class _ValueType>
-_LIBCPP_INLINE_VISIBILITY
-add_pointer_t<_ValueType> any_cast(any *) _NOEXCEPT;
-
-namespace __any_imp
-{
-  using _Buffer = aligned_storage_t<3*sizeof(void*), alignment_of<void*>::value>;
-
-  template <class _Tp>
-  using _IsSmallObject = integral_constant<bool
-        , sizeof(_Tp) <= sizeof(_Buffer)
-          && alignment_of<_Buffer>::value
-             % alignment_of<_Tp>::value == 0
-          && is_nothrow_move_constructible<_Tp>::value
-        >;
-
-  enum class _Action {
-    _Destroy,
-    _Copy,
-    _Move,
-    _Get,
-    _TypeInfo
-  };
-
-  template <class _Tp> struct _SmallHandler;
-  template <class _Tp> struct _LargeHandler;
-
-  template <class _Tp>
-  struct  _LIBCPP_TEMPLATE_VIS __unique_typeinfo { static constexpr int __id = 0; };
-  template <class _Tp> constexpr int __unique_typeinfo<_Tp>::__id;
-
-  template <class _Tp>
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr const void* __get_fallback_typeid() {
-      return &__unique_typeinfo<decay_t<_Tp>>::__id;
-  }
-
-  template <class _Tp>
-  inline _LIBCPP_INLINE_VISIBILITY
-  bool __compare_typeid(type_info const* __id, const void* __fallback_id)
-  {
-#if !defined(_LIBCPP_NO_RTTI)
-      if (__id && *__id == typeid(_Tp))
-          return true;
-#endif
-      if (!__id && __fallback_id == __any_imp::__get_fallback_typeid<_Tp>())
-          return true;
-      return false;
-  }
-
-  template <class _Tp>
-  using _Handler = conditional_t<
-    _IsSmallObject<_Tp>::value, _SmallHandler<_Tp>, _LargeHandler<_Tp>>;
-
-} // namespace __any_imp
-
-class _LIBCPP_TEMPLATE_VIS any
-{
-public:
-  // construct/destruct
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr any() _NOEXCEPT : __h(nullptr) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  any(any const & __other) : __h(nullptr)
-  {
-    if (__other.__h) __other.__call(_Action::_Copy, this);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  any(any && __other) _NOEXCEPT : __h(nullptr)
-  {
-    if (__other.__h) __other.__call(_Action::_Move, this);
-  }
-
-  template <
-      class _ValueType
-    , class _Tp = decay_t<_ValueType>
-    , class = enable_if_t<
-        !is_same<_Tp, any>::value &&
-        !__is_inplace_type<_ValueType>::value &&
-        is_copy_constructible<_Tp>::value>
-    >
-  _LIBCPP_INLINE_VISIBILITY
-  any(_ValueType && __value);
-
-  template <class _ValueType, class ..._Args,
-    class _Tp = decay_t<_ValueType>,
-    class = enable_if_t<
-        is_constructible<_Tp, _Args...>::value &&
-        is_copy_constructible<_Tp>::value
-    >
-  >
-  _LIBCPP_INLINE_VISIBILITY
-  explicit any(in_place_type_t<_ValueType>, _Args&&... __args);
-
-  template <class _ValueType, class _Up, class ..._Args,
-    class _Tp = decay_t<_ValueType>,
-    class = enable_if_t<
-        is_constructible<_Tp, initializer_list<_Up>&, _Args...>::value &&
-        is_copy_constructible<_Tp>::value>
-  >
-  _LIBCPP_INLINE_VISIBILITY
-  explicit any(in_place_type_t<_ValueType>, initializer_list<_Up>, _Args&&... __args);
-
-  _LIBCPP_INLINE_VISIBILITY
-  ~any() { this->reset(); }
-
-  // assignments
-  _LIBCPP_INLINE_VISIBILITY
-  any & operator=(any const & __rhs) {
-    any(__rhs).swap(*this);
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  any & operator=(any && __rhs) _NOEXCEPT {
-    any(_VSTD::move(__rhs)).swap(*this);
-    return *this;
-  }
-
-  template <
-      class _ValueType
-    , class _Tp = decay_t<_ValueType>
-    , class = enable_if_t<
-          !is_same<_Tp, any>::value
-          && is_copy_constructible<_Tp>::value>
-    >
-  _LIBCPP_INLINE_VISIBILITY
-  any & operator=(_ValueType && __rhs);
-
-  template <class _ValueType, class ..._Args,
-    class _Tp = decay_t<_ValueType>,
-    class = enable_if_t<
-        is_constructible<_Tp, _Args...>::value &&
-        is_copy_constructible<_Tp>::value>
-    >
-  _LIBCPP_INLINE_VISIBILITY
-  _Tp& emplace(_Args&&... args);
-
-  template <class _ValueType, class _Up, class ..._Args,
-    class _Tp = decay_t<_ValueType>,
-    class = enable_if_t<
-        is_constructible<_Tp, initializer_list<_Up>&, _Args...>::value &&
-        is_copy_constructible<_Tp>::value>
-  >
-  _LIBCPP_INLINE_VISIBILITY
-  _Tp& emplace(initializer_list<_Up>, _Args&&...);
-
-  // 6.3.3 any modifiers
-  _LIBCPP_INLINE_VISIBILITY
-  void reset() _NOEXCEPT { if (__h) this->__call(_Action::_Destroy); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void swap(any & __rhs) _NOEXCEPT;
-
-  // 6.3.4 any observers
-  _LIBCPP_INLINE_VISIBILITY
-  bool has_value() const _NOEXCEPT { return __h != nullptr; }
-
-#if !defined(_LIBCPP_NO_RTTI)
-  _LIBCPP_INLINE_VISIBILITY
-  const type_info & type() const _NOEXCEPT {
-    if (__h) {
-        return *static_cast<type_info const *>(this->__call(_Action::_TypeInfo));
-    } else {
-        return typeid(void);
-    }
-  }
-#endif
-
-private:
-    typedef __any_imp::_Action _Action;
-    using _HandleFuncPtr =  void* (*)(_Action, any const *, any *, const type_info *,
-      const void* __fallback_info);
-
-    union _Storage {
-        constexpr _Storage() : __ptr(nullptr) {}
-        void *  __ptr;
-        __any_imp::_Buffer __buf;
-    };
-
-    _LIBCPP_INLINE_VISIBILITY
-    void * __call(_Action __a, any * __other = nullptr,
-                  type_info const * __info = nullptr,
-                   const void* __fallback_info = nullptr) const
-    {
-        return __h(__a, this, __other, __info, __fallback_info);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void * __call(_Action __a, any * __other = nullptr,
-                  type_info const * __info = nullptr,
-                  const void* __fallback_info = nullptr)
-    {
-        return __h(__a, this, __other, __info, __fallback_info);
-    }
-
-    template <class>
-    friend struct __any_imp::_SmallHandler;
-    template <class>
-    friend struct __any_imp::_LargeHandler;
-
-    template <class _ValueType>
-    friend add_pointer_t<add_const_t<_ValueType>>
-    any_cast(any const *) _NOEXCEPT;
-
-    template <class _ValueType>
-    friend add_pointer_t<_ValueType>
-    any_cast(any *) _NOEXCEPT;
-
-    _HandleFuncPtr __h = nullptr;
-    _Storage __s;
-};
-
-namespace __any_imp
-{
-  template <class _Tp>
-  struct _LIBCPP_TEMPLATE_VIS _SmallHandler
-  {
-     _LIBCPP_INLINE_VISIBILITY
-     static void* __handle(_Action __act, any const * __this, any * __other,
-                           type_info const * __info, const void* __fallback_info)
-     {
-        switch (__act)
-        {
-        case _Action::_Destroy:
-          __destroy(const_cast<any &>(*__this));
-          return nullptr;
-        case _Action::_Copy:
-            __copy(*__this, *__other);
-            return nullptr;
-        case _Action::_Move:
-          __move(const_cast<any &>(*__this), *__other);
-          return nullptr;
-        case _Action::_Get:
-            return __get(const_cast<any &>(*__this), __info, __fallback_info);
-        case _Action::_TypeInfo:
-          return __type_info();
-        }
-    }
-
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    static _Tp& __create(any & __dest, _Args&&... __args) {
-        _Tp* __ret = ::new (static_cast<void*>(&__dest.__s.__buf)) _Tp(_VSTD::forward<_Args>(__args)...);
-        __dest.__h = &_SmallHandler::__handle;
-        return *__ret;
-    }
-
-  private:
-    _LIBCPP_INLINE_VISIBILITY
-    static void __destroy(any & __this) {
-        _Tp & __value = *static_cast<_Tp *>(static_cast<void*>(&__this.__s.__buf));
-        __value.~_Tp();
-        __this.__h = nullptr;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void __copy(any const & __this, any & __dest) {
-        _SmallHandler::__create(__dest, *static_cast<_Tp const *>(
-            static_cast<void const *>(&__this.__s.__buf)));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void __move(any & __this, any & __dest) {
-        _SmallHandler::__create(__dest, _VSTD::move(
-            *static_cast<_Tp*>(static_cast<void*>(&__this.__s.__buf))));
-        __destroy(__this);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void* __get(any & __this,
-                       type_info const * __info,
-                       const void* __fallback_id)
-    {
-        if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_id))
-            return static_cast<void*>(&__this.__s.__buf);
-        return nullptr;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void* __type_info()
-    {
-#if !defined(_LIBCPP_NO_RTTI)
-        return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
-#else
-        return nullptr;
-#endif
-    }
-  };
-
-  template <class _Tp>
-  struct _LIBCPP_TEMPLATE_VIS _LargeHandler
-  {
-    _LIBCPP_INLINE_VISIBILITY
-    static void* __handle(_Action __act, any const * __this,
-                          any * __other, type_info const * __info,
-                          void const* __fallback_info)
-    {
-        switch (__act)
-        {
-        case _Action::_Destroy:
-          __destroy(const_cast<any &>(*__this));
-          return nullptr;
-        case _Action::_Copy:
-          __copy(*__this, *__other);
-          return nullptr;
-        case _Action::_Move:
-          __move(const_cast<any &>(*__this), *__other);
-          return nullptr;
-        case _Action::_Get:
-            return __get(const_cast<any &>(*__this), __info, __fallback_info);
-        case _Action::_TypeInfo:
-          return __type_info();
-        }
-    }
-
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    static _Tp& __create(any & __dest, _Args&&... __args) {
-        typedef allocator<_Tp> _Alloc;
-        typedef __allocator_destructor<_Alloc> _Dp;
-        _Alloc __a;
-        unique_ptr<_Tp, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-        _Tp* __ret = ::new ((void*)__hold.get()) _Tp(_VSTD::forward<_Args>(__args)...);
-        __dest.__s.__ptr = __hold.release();
-        __dest.__h = &_LargeHandler::__handle;
-        return *__ret;
-    }
-
-  private:
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void __destroy(any & __this){
-        delete static_cast<_Tp*>(__this.__s.__ptr);
-        __this.__h = nullptr;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void __copy(any const & __this, any & __dest) {
-        _LargeHandler::__create(__dest, *static_cast<_Tp const *>(__this.__s.__ptr));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void __move(any & __this, any & __dest) {
-      __dest.__s.__ptr = __this.__s.__ptr;
-      __dest.__h = &_LargeHandler::__handle;
-      __this.__h = nullptr;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void* __get(any & __this, type_info const * __info,
-                       void const* __fallback_info)
-    {
-        if (__any_imp::__compare_typeid<_Tp>(__info, __fallback_info))
-            return static_cast<void*>(__this.__s.__ptr);
-        return nullptr;
-
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void* __type_info()
-    {
-#if !defined(_LIBCPP_NO_RTTI)
-        return const_cast<void*>(static_cast<void const *>(&typeid(_Tp)));
-#else
-        return nullptr;
-#endif
-    }
-  };
-
-} // namespace __any_imp
-
-
-template <class _ValueType, class _Tp, class>
-any::any(_ValueType && __v) : __h(nullptr)
-{
-  __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_ValueType>(__v));
-}
-
-template <class _ValueType, class ..._Args, class _Tp, class>
-any::any(in_place_type_t<_ValueType>, _Args&&... __args) {
-  __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_Args>(__args)...);
-};
-
-template <class _ValueType, class _Up, class ..._Args, class _Tp, class>
-any::any(in_place_type_t<_ValueType>, initializer_list<_Up> __il, _Args&&... __args) {
-  __any_imp::_Handler<_Tp>::__create(*this, __il, _VSTD::forward<_Args>(__args)...);
-}
-
-template <class _ValueType, class, class>
-inline _LIBCPP_INLINE_VISIBILITY
-any & any::operator=(_ValueType && __v)
-{
-  any(_VSTD::forward<_ValueType>(__v)).swap(*this);
-  return *this;
-}
-
-template <class _ValueType, class ..._Args, class _Tp, class>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp& any::emplace(_Args&&... __args) {
-  reset();
-  return __any_imp::_Handler<_Tp>::__create(*this, _VSTD::forward<_Args>(__args)...);
-}
-
-template <class _ValueType, class _Up, class ..._Args, class _Tp, class>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp& any::emplace(initializer_list<_Up> __il, _Args&&... __args) {
-  reset();
-  return __any_imp::_Handler<_Tp>::__create(*this, __il, _VSTD::forward<_Args>(__args)...);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void any::swap(any & __rhs) _NOEXCEPT
-{
-    if (this == &__rhs)
-      return;
-    if (__h && __rhs.__h) {
-        any __tmp;
-        __rhs.__call(_Action::_Move, &__tmp);
-        this->__call(_Action::_Move, &__rhs);
-        __tmp.__call(_Action::_Move, this);
-    }
-    else if (__h) {
-        this->__call(_Action::_Move, &__rhs);
-    }
-    else if (__rhs.__h) {
-        __rhs.__call(_Action::_Move, this);
-    }
-}
-
-// 6.4 Non-member functions
-
-inline _LIBCPP_INLINE_VISIBILITY
-void swap(any & __lhs, any & __rhs) _NOEXCEPT
-{
-    __lhs.swap(__rhs);
-}
-
-template <class _Tp, class ..._Args>
-inline _LIBCPP_INLINE_VISIBILITY
-any make_any(_Args&&... __args) {
-    return any(in_place_type<_Tp>, _VSTD::forward<_Args>(__args)...);
-}
-
-template <class _Tp, class _Up, class ..._Args>
-inline _LIBCPP_INLINE_VISIBILITY
-any make_any(initializer_list<_Up> __il, _Args&&... __args) {
-    return any(in_place_type<_Tp>, __il, _VSTD::forward<_Args>(__args)...);
-}
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
-_ValueType any_cast(any const & __v)
-{
-    using _RawValueType = __uncvref_t<_ValueType>;
-    static_assert(is_constructible<_ValueType, _RawValueType const &>::value,
-                  "ValueType is required to be a const lvalue reference "
-                  "or a CopyConstructible type");
-    auto __tmp = _VSTD::any_cast<add_const_t<_RawValueType>>(&__v);
-    if (__tmp == nullptr)
-        __throw_bad_any_cast();
-    return static_cast<_ValueType>(*__tmp);
-}
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
-_ValueType any_cast(any & __v)
-{
-    using _RawValueType = __uncvref_t<_ValueType>;
-    static_assert(is_constructible<_ValueType, _RawValueType &>::value,
-                  "ValueType is required to be an lvalue reference "
-                  "or a CopyConstructible type");
-    auto __tmp = _VSTD::any_cast<_RawValueType>(&__v);
-    if (__tmp == nullptr)
-        __throw_bad_any_cast();
-    return static_cast<_ValueType>(*__tmp);
-}
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_ANY_CAST
-_ValueType any_cast(any && __v)
-{
-    using _RawValueType = __uncvref_t<_ValueType>;
-    static_assert(is_constructible<_ValueType, _RawValueType>::value,
-                  "ValueType is required to be an rvalue reference "
-                  "or a CopyConstructible type");
-    auto __tmp = _VSTD::any_cast<_RawValueType>(&__v);
-    if (__tmp == nullptr)
-        __throw_bad_any_cast();
-    return static_cast<_ValueType>(_VSTD::move(*__tmp));
-}
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-add_pointer_t<add_const_t<_ValueType>>
-any_cast(any const * __any) _NOEXCEPT
-{
-    static_assert(!is_reference<_ValueType>::value,
-                  "_ValueType may not be a reference.");
-    return _VSTD::any_cast<_ValueType>(const_cast<any *>(__any));
-}
-
-template <class _RetType>
-inline _LIBCPP_INLINE_VISIBILITY
-_RetType __pointer_or_func_cast(void* __p, /*IsFunction*/false_type) noexcept {
-  return static_cast<_RetType>(__p);
-}
-
-template <class _RetType>
-inline _LIBCPP_INLINE_VISIBILITY
-_RetType __pointer_or_func_cast(void*, /*IsFunction*/true_type) noexcept {
-  return nullptr;
-}
-
-template <class _ValueType>
-add_pointer_t<_ValueType>
-any_cast(any * __any) _NOEXCEPT
-{
-    using __any_imp::_Action;
-    static_assert(!is_reference<_ValueType>::value,
-                  "_ValueType may not be a reference.");
-    typedef typename add_pointer<_ValueType>::type _ReturnType;
-    if (__any && __any->__h) {
-      void *__p = __any->__call(_Action::_Get, nullptr,
-#if !defined(_LIBCPP_NO_RTTI)
-                          &typeid(_ValueType),
-#else
-                          nullptr,
-#endif
-                          __any_imp::__get_fallback_typeid<_ValueType>());
-        return _VSTD::__pointer_or_func_cast<_ReturnType>(
-            __p, is_function<_ValueType>{});
-    }
-    return nullptr;
-}
-
-#endif // _LIBCPP_STD_VER > 14
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP_ANY
diff --git a/lib/libcxx/include/array b/lib/libcxx/include/array
deleted file mode 100644
index 56f6887655a..00000000000
--- a/lib/libcxx/include/array
+++ /dev/null
@@ -1,486 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- array -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_ARRAY
-#define _LIBCPP_ARRAY
-
-/*
-    array synopsis
-
-namespace std
-{
-template <class T, size_t N >
-struct array
-{
-    // types:
-    typedef T & reference;
-    typedef const T & const_reference;
-    typedef implementation defined iterator;
-    typedef implementation defined const_iterator;
-    typedef size_t size_type;
-    typedef ptrdiff_t difference_type;
-    typedef T value_type;
-    typedef T* pointer;
-    typedef const T* const_pointer;
-    typedef std::reverse_iterator<iterator> reverse_iterator;
-    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
-
-    // No explicit construct/copy/destroy for aggregate type
-    void fill(const T& u);
-    void swap(array& a) noexcept(is_nothrow_swappable_v<T>);
-
-    // iterators:
-    iterator begin() noexcept;
-    const_iterator begin() const noexcept;
-    iterator end() noexcept;
-    const_iterator end() const noexcept;
-
-    reverse_iterator rbegin() noexcept;
-    const_reverse_iterator rbegin() const noexcept;
-    reverse_iterator rend() noexcept;
-    const_reverse_iterator rend() const noexcept;
-
-    const_iterator cbegin() const noexcept;
-    const_iterator cend() const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend() const noexcept;
-
-    // capacity:
-    constexpr size_type size() const noexcept;
-    constexpr size_type max_size() const noexcept;
-    constexpr bool empty() const noexcept;
-
-    // element access:
-    reference operator[](size_type n);
-    const_reference operator[](size_type n) const; // constexpr in C++14
-    const_reference at(size_type n) const; // constexpr in C++14
-    reference at(size_type n);
-
-    reference front();
-    const_reference front() const; // constexpr in C++14
-    reference back();
-    const_reference back() const; // constexpr in C++14
-
-    T* data() noexcept;
-    const T* data() const noexcept;
-};
-
-  template <class T, class... U>
-    array(T, U...) -> array<T, 1 + sizeof...(U)>;
-
-template <class T, size_t N>
-  bool operator==(const array<T,N>& x, const array<T,N>& y);
-template <class T, size_t N>
-  bool operator!=(const array<T,N>& x, const array<T,N>& y);
-template <class T, size_t N>
-  bool operator<(const array<T,N>& x, const array<T,N>& y);
-template <class T, size_t N>
-  bool operator>(const array<T,N>& x, const array<T,N>& y);
-template <class T, size_t N>
-  bool operator<=(const array<T,N>& x, const array<T,N>& y);
-template <class T, size_t N>
-  bool operator>=(const array<T,N>& x, const array<T,N>& y);
-
-template <class T, size_t N >
-  void swap(array<T,N>& x, array<T,N>& y) noexcept(noexcept(x.swap(y))); // C++17
-
-template <class T> struct tuple_size;
-template <size_t I, class T> class tuple_element;
-template <class T, size_t N> struct tuple_size<array<T, N>>;
-template <size_t I, class T, size_t N> struct tuple_element<I, array<T, N>>;
-template <size_t I, class T, size_t N> T& get(array<T, N>&) noexcept; // constexpr in C++14
-template <size_t I, class T, size_t N> const T& get(const array<T, N>&) noexcept; // constexpr in C++14
-template <size_t I, class T, size_t N> T&& get(array<T, N>&&) noexcept; // constexpr in C++14
-template <size_t I, class T, size_t N> const T&& get(const array<T, N>&&) noexcept; // constexpr in C++14
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__tuple>
-#include <type_traits>
-#include <utility>
-#include <iterator>
-#include <algorithm>
-#include <stdexcept>
-#include <cstdlib> // for _LIBCPP_UNREACHABLE
-#include <version>
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-
-template <class _Tp, size_t _Size>
-struct _LIBCPP_TEMPLATE_VIS array
-{
-    // types:
-    typedef array __self;
-    typedef _Tp                                   value_type;
-    typedef value_type&                           reference;
-    typedef const value_type&                     const_reference;
-    typedef value_type*                           iterator;
-    typedef const value_type*                     const_iterator;
-    typedef value_type*                           pointer;
-    typedef const value_type*                     const_pointer;
-    typedef size_t                                size_type;
-    typedef ptrdiff_t                             difference_type;
-    typedef std::reverse_iterator<iterator>       reverse_iterator;
-    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
-
-    _Tp __elems_[_Size];
-
-    // No explicit construct/copy/destroy for aggregate type
-    _LIBCPP_INLINE_VISIBILITY void fill(const value_type& __u) {
-      _VSTD::fill_n(__elems_, _Size, __u);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(array& __a) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value) {
-      std::swap_ranges(__elems_, __elems_ + _Size, __a.__elems_);
-    }
-
-    // iterators:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    iterator begin() _NOEXCEPT {return iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    iterator end() _NOEXCEPT {return iterator(data() + _Size);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const_iterator end() const _NOEXCEPT {return const_iterator(data() + _Size);}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const_iterator cbegin() const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
-
-    // capacity:
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return _Size;}
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return _Size;}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return false; }
-
-    // element access:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reference operator[](size_type __n)             {return __elems_[__n];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const_reference operator[](size_type __n) const {return __elems_[__n];}
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX14       reference at(size_type __n);
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference at(size_type __n) const;
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference front()             {return __elems_[0];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference front() const {return __elems_[0];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 reference back()              {return __elems_[_Size - 1];}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const_reference back() const  {return __elems_[_Size - 1];}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    value_type* data() _NOEXCEPT {return __elems_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    const value_type* data() const _NOEXCEPT {return __elems_;}
-};
-
-
-template <class _Tp, size_t _Size>
-_LIBCPP_CONSTEXPR_AFTER_CXX14
-typename array<_Tp, _Size>::reference
-array<_Tp, _Size>::at(size_type __n)
-{
-    if (__n >= _Size)
-        __throw_out_of_range("array::at");
-
-    return __elems_[__n];
-}
-
-template <class _Tp, size_t _Size>
-_LIBCPP_CONSTEXPR_AFTER_CXX11
-typename array<_Tp, _Size>::const_reference
-array<_Tp, _Size>::at(size_type __n) const
-{
-    if (__n >= _Size)
-        __throw_out_of_range("array::at");
-    return __elems_[__n];
-}
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS array<_Tp, 0>
-{
-    // types:
-    typedef array __self;
-    typedef _Tp                                   value_type;
-    typedef value_type&                           reference;
-    typedef const value_type&                     const_reference;
-    typedef value_type*                           iterator;
-    typedef const value_type*                     const_iterator;
-    typedef value_type*                           pointer;
-    typedef const value_type*                     const_pointer;
-    typedef size_t                                size_type;
-    typedef ptrdiff_t                             difference_type;
-    typedef std::reverse_iterator<iterator>       reverse_iterator;
-    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
-
-    typedef typename conditional<is_const<_Tp>::value, const char,
-                                char>::type _CharType;
-
-    struct  _ArrayInStructT { _Tp __data_[1]; };
-    _ALIGNAS_TYPE(_ArrayInStructT) _CharType __elems_[sizeof(_ArrayInStructT)];
-
-    // No explicit construct/copy/destroy for aggregate type
-    _LIBCPP_INLINE_VISIBILITY void fill(const value_type&) {
-      static_assert(!is_const<_Tp>::value,
-                    "cannot fill zero-sized array of type 'const T'");
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(array&) _NOEXCEPT {
-      static_assert(!is_const<_Tp>::value,
-                    "cannot swap zero-sized array of type 'const T'");
-    }
-
-    // iterators:
-    _LIBCPP_INLINE_VISIBILITY
-    iterator begin() _NOEXCEPT {return iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT {return const_iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator end() _NOEXCEPT {return iterator(data());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT {return const_iterator(data());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin() const _NOEXCEPT {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend() const _NOEXCEPT {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
-
-    // capacity:
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR size_type size() const _NOEXCEPT {return 0; }
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR size_type max_size() const _NOEXCEPT {return 0;}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR bool empty() const _NOEXCEPT {return true;}
-
-    // element access:
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator[](size_type) {
-      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
-      _LIBCPP_UNREACHABLE();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const_reference operator[](size_type) const {
-      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::operator[] on a zero-sized array");
-      _LIBCPP_UNREACHABLE();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference at(size_type) {
-      __throw_out_of_range("array<T, 0>::at");
-      _LIBCPP_UNREACHABLE();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference at(size_type) const {
-      __throw_out_of_range("array<T, 0>::at");
-      _LIBCPP_UNREACHABLE();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference front() {
-      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
-      _LIBCPP_UNREACHABLE();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference front() const {
-      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::front() on a zero-sized array");
-      _LIBCPP_UNREACHABLE();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference back() {
-      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
-      _LIBCPP_UNREACHABLE();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference back() const {
-      _LIBCPP_ASSERT(false, "cannot call array<T, 0>::back() on a zero-sized array");
-      _LIBCPP_UNREACHABLE();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type* data() _NOEXCEPT {return reinterpret_cast<value_type*>(__elems_);}
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type* data() const _NOEXCEPT {return reinterpret_cast<const value_type*>(__elems_);}
-};
-
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class _Tp, class... _Args,
-         class = typename enable_if<(is_same_v<_Tp, _Args> && ...), void>::type
-         >
-array(_Tp, _Args...)
-  -> array<_Tp, 1 + sizeof...(_Args)>;
-#endif
-
-template <class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-operator==(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
-{
-    return _VSTD::equal(__x.begin(), __x.end(), __y.begin());
-}
-
-template <class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-operator!=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-operator<(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
-{
-    return _VSTD::lexicographical_compare(__x.begin(), __x.end(),
-                                          __y.begin(), __y.end());
-}
-
-template <class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-operator>(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-operator<=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX17 bool
-operator>=(const array<_Tp, _Size>& __x, const array<_Tp, _Size>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    _Size == 0 ||
-    __is_swappable<_Tp>::value,
-    void
->::type
-swap(array<_Tp, _Size>& __x, array<_Tp, _Size>& __y)
-                                  _NOEXCEPT_(noexcept(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-template <class _Tp, size_t _Size>
-struct _LIBCPP_TEMPLATE_VIS tuple_size<array<_Tp, _Size> >
-    : public integral_constant<size_t, _Size> {};
-
-template <size_t _Ip, class _Tp, size_t _Size>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, array<_Tp, _Size> >
-{
-    static_assert(_Ip < _Size, "Index out of bounds in std::tuple_element<> (std::array)");
-public:
-    typedef _Tp type;
-};
-
-template <size_t _Ip, class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp&
-get(array<_Tp, _Size>& __a) _NOEXCEPT
-{
-    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array)");
-    return __a.__elems_[_Ip];
-}
-
-template <size_t _Ip, class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&
-get(const array<_Tp, _Size>& __a) _NOEXCEPT
-{
-    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array)");
-    return __a.__elems_[_Ip];
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <size_t _Ip, class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp&&
-get(array<_Tp, _Size>&& __a) _NOEXCEPT
-{
-    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (std::array &&)");
-    return _VSTD::move(__a.__elems_[_Ip]);
-}
-
-template <size_t _Ip, class _Tp, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Tp&&
-get(const array<_Tp, _Size>&& __a) _NOEXCEPT
-{
-    static_assert(_Ip < _Size, "Index out of bounds in std::get<> (const std::array &&)");
-    return _VSTD::move(__a.__elems_[_Ip]);
-}
-
-#endif  // !_LIBCPP_CXX03_LANG
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_ARRAY
diff --git a/lib/libcxx/include/atomic b/lib/libcxx/include/atomic
deleted file mode 100644
index d37e7b4b035..00000000000
--- a/lib/libcxx/include/atomic
+++ /dev/null
@@ -1,1888 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- atomic -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_ATOMIC
-#define _LIBCPP_ATOMIC
-
-/*
-    atomic synopsis
-
-namespace std
-{
-
-// feature test macro
-
-#define __cpp_lib_atomic_is_always_lock_free // as specified by SG10
-
-// order and consistency
-
-typedef enum memory_order
-{
-    memory_order_relaxed,
-    memory_order_consume,  // load-consume
-    memory_order_acquire,  // load-acquire
-    memory_order_release,  // store-release
-    memory_order_acq_rel,  // store-release load-acquire
-    memory_order_seq_cst   // store-release load-acquire
-} memory_order;
-
-template <class T> T kill_dependency(T y) noexcept;
-
-// lock-free property
-
-#define ATOMIC_BOOL_LOCK_FREE unspecified
-#define ATOMIC_CHAR_LOCK_FREE unspecified
-#define ATOMIC_CHAR16_T_LOCK_FREE unspecified
-#define ATOMIC_CHAR32_T_LOCK_FREE unspecified
-#define ATOMIC_WCHAR_T_LOCK_FREE unspecified
-#define ATOMIC_SHORT_LOCK_FREE unspecified
-#define ATOMIC_INT_LOCK_FREE unspecified
-#define ATOMIC_LONG_LOCK_FREE unspecified
-#define ATOMIC_LLONG_LOCK_FREE unspecified
-#define ATOMIC_POINTER_LOCK_FREE unspecified
-
-// flag type and operations
-
-typedef struct atomic_flag
-{
-    bool test_and_set(memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool test_and_set(memory_order m = memory_order_seq_cst) noexcept;
-    void clear(memory_order m = memory_order_seq_cst) volatile noexcept;
-    void clear(memory_order m = memory_order_seq_cst) noexcept;
-    atomic_flag()  noexcept = default;
-    atomic_flag(const atomic_flag&) = delete;
-    atomic_flag& operator=(const atomic_flag&) = delete;
-    atomic_flag& operator=(const atomic_flag&) volatile = delete;
-} atomic_flag;
-
-bool
-    atomic_flag_test_and_set(volatile atomic_flag* obj) noexcept;
-
-bool
-    atomic_flag_test_and_set(atomic_flag* obj) noexcept;
-
-bool
-    atomic_flag_test_and_set_explicit(volatile atomic_flag* obj,
-                                      memory_order m) noexcept;
-
-bool
-    atomic_flag_test_and_set_explicit(atomic_flag* obj, memory_order m) noexcept;
-
-void
-    atomic_flag_clear(volatile atomic_flag* obj) noexcept;
-
-void
-    atomic_flag_clear(atomic_flag* obj) noexcept;
-
-void
-    atomic_flag_clear_explicit(volatile atomic_flag* obj, memory_order m) noexcept;
-
-void
-    atomic_flag_clear_explicit(atomic_flag* obj, memory_order m) noexcept;
-
-#define ATOMIC_FLAG_INIT see below
-#define ATOMIC_VAR_INIT(value) see below
-
-template <class T>
-struct atomic
-{
-    static constexpr bool is_always_lock_free;
-    bool is_lock_free() const volatile noexcept;
-    bool is_lock_free() const noexcept;
-    void store(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    void store(T desr, memory_order m = memory_order_seq_cst) noexcept;
-    T load(memory_order m = memory_order_seq_cst) const volatile noexcept;
-    T load(memory_order m = memory_order_seq_cst) const noexcept;
-    operator T() const volatile noexcept;
-    operator T() const noexcept;
-    T exchange(T desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    T exchange(T desr, memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_weak(T& expc, T desr,
-                               memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_weak(T& expc, T desr, memory_order s, memory_order f) noexcept;
-    bool compare_exchange_strong(T& expc, T desr,
-                                 memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_strong(T& expc, T desr,
-                                 memory_order s, memory_order f) noexcept;
-    bool compare_exchange_weak(T& expc, T desr,
-                               memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_weak(T& expc, T desr,
-                               memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_strong(T& expc, T desr,
-                                memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_strong(T& expc, T desr,
-                                 memory_order m = memory_order_seq_cst) noexcept;
-
-    atomic() noexcept = default;
-    constexpr atomic(T desr) noexcept;
-    atomic(const atomic&) = delete;
-    atomic& operator=(const atomic&) = delete;
-    atomic& operator=(const atomic&) volatile = delete;
-    T operator=(T) volatile noexcept;
-    T operator=(T) noexcept;
-};
-
-template <>
-struct atomic<integral>
-{
-    static constexpr bool is_always_lock_free;
-    bool is_lock_free() const volatile noexcept;
-    bool is_lock_free() const noexcept;
-    void store(integral desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    void store(integral desr, memory_order m = memory_order_seq_cst) noexcept;
-    integral load(memory_order m = memory_order_seq_cst) const volatile noexcept;
-    integral load(memory_order m = memory_order_seq_cst) const noexcept;
-    operator integral() const volatile noexcept;
-    operator integral() const noexcept;
-    integral exchange(integral desr,
-                      memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral exchange(integral desr, memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_weak(integral& expc, integral desr,
-                               memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_weak(integral& expc, integral desr,
-                               memory_order s, memory_order f) noexcept;
-    bool compare_exchange_strong(integral& expc, integral desr,
-                                 memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_strong(integral& expc, integral desr,
-                                 memory_order s, memory_order f) noexcept;
-    bool compare_exchange_weak(integral& expc, integral desr,
-                               memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_weak(integral& expc, integral desr,
-                               memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_strong(integral& expc, integral desr,
-                                memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_strong(integral& expc, integral desr,
-                                 memory_order m = memory_order_seq_cst) noexcept;
-
-    integral
-        fetch_add(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_add(integral op, memory_order m = memory_order_seq_cst) noexcept;
-    integral
-        fetch_sub(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_sub(integral op, memory_order m = memory_order_seq_cst) noexcept;
-    integral
-        fetch_and(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_and(integral op, memory_order m = memory_order_seq_cst) noexcept;
-    integral
-        fetch_or(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_or(integral op, memory_order m = memory_order_seq_cst) noexcept;
-    integral
-        fetch_xor(integral op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    integral fetch_xor(integral op, memory_order m = memory_order_seq_cst) noexcept;
-
-    atomic() noexcept = default;
-    constexpr atomic(integral desr) noexcept;
-    atomic(const atomic&) = delete;
-    atomic& operator=(const atomic&) = delete;
-    atomic& operator=(const atomic&) volatile = delete;
-    integral operator=(integral desr) volatile noexcept;
-    integral operator=(integral desr) noexcept;
-
-    integral operator++(int) volatile noexcept;
-    integral operator++(int) noexcept;
-    integral operator--(int) volatile noexcept;
-    integral operator--(int) noexcept;
-    integral operator++() volatile noexcept;
-    integral operator++() noexcept;
-    integral operator--() volatile noexcept;
-    integral operator--() noexcept;
-    integral operator+=(integral op) volatile noexcept;
-    integral operator+=(integral op) noexcept;
-    integral operator-=(integral op) volatile noexcept;
-    integral operator-=(integral op) noexcept;
-    integral operator&=(integral op) volatile noexcept;
-    integral operator&=(integral op) noexcept;
-    integral operator|=(integral op) volatile noexcept;
-    integral operator|=(integral op) noexcept;
-    integral operator^=(integral op) volatile noexcept;
-    integral operator^=(integral op) noexcept;
-};
-
-template <class T>
-struct atomic<T*>
-{
-    static constexpr bool is_always_lock_free;
-    bool is_lock_free() const volatile noexcept;
-    bool is_lock_free() const noexcept;
-    void store(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    void store(T* desr, memory_order m = memory_order_seq_cst) noexcept;
-    T* load(memory_order m = memory_order_seq_cst) const volatile noexcept;
-    T* load(memory_order m = memory_order_seq_cst) const noexcept;
-    operator T*() const volatile noexcept;
-    operator T*() const noexcept;
-    T* exchange(T* desr, memory_order m = memory_order_seq_cst) volatile noexcept;
-    T* exchange(T* desr, memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_weak(T*& expc, T* desr,
-                               memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_weak(T*& expc, T* desr,
-                               memory_order s, memory_order f) noexcept;
-    bool compare_exchange_strong(T*& expc, T* desr,
-                                 memory_order s, memory_order f) volatile noexcept;
-    bool compare_exchange_strong(T*& expc, T* desr,
-                                 memory_order s, memory_order f) noexcept;
-    bool compare_exchange_weak(T*& expc, T* desr,
-                               memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_weak(T*& expc, T* desr,
-                               memory_order m = memory_order_seq_cst) noexcept;
-    bool compare_exchange_strong(T*& expc, T* desr,
-                                memory_order m = memory_order_seq_cst) volatile noexcept;
-    bool compare_exchange_strong(T*& expc, T* desr,
-                                 memory_order m = memory_order_seq_cst) noexcept;
-    T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    T* fetch_add(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;
-    T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) volatile noexcept;
-    T* fetch_sub(ptrdiff_t op, memory_order m = memory_order_seq_cst) noexcept;
-
-    atomic() noexcept = default;
-    constexpr atomic(T* desr) noexcept;
-    atomic(const atomic&) = delete;
-    atomic& operator=(const atomic&) = delete;
-    atomic& operator=(const atomic&) volatile = delete;
-
-    T* operator=(T*) volatile noexcept;
-    T* operator=(T*) noexcept;
-    T* operator++(int) volatile noexcept;
-    T* operator++(int) noexcept;
-    T* operator--(int) volatile noexcept;
-    T* operator--(int) noexcept;
-    T* operator++() volatile noexcept;
-    T* operator++() noexcept;
-    T* operator--() volatile noexcept;
-    T* operator--() noexcept;
-    T* operator+=(ptrdiff_t op) volatile noexcept;
-    T* operator+=(ptrdiff_t op) noexcept;
-    T* operator-=(ptrdiff_t op) volatile noexcept;
-    T* operator-=(ptrdiff_t op) noexcept;
-};
-
-
-template <class T>
-    bool
-    atomic_is_lock_free(const volatile atomic<T>* obj) noexcept;
-
-template <class T>
-    bool
-    atomic_is_lock_free(const atomic<T>* obj) noexcept;
-
-template <class T>
-    void
-    atomic_init(volatile atomic<T>* obj, T desr) noexcept;
-
-template <class T>
-    void
-    atomic_init(atomic<T>* obj, T desr) noexcept;
-
-template <class T>
-    void
-    atomic_store(volatile atomic<T>* obj, T desr) noexcept;
-
-template <class T>
-    void
-    atomic_store(atomic<T>* obj, T desr) noexcept;
-
-template <class T>
-    void
-    atomic_store_explicit(volatile atomic<T>* obj, T desr, memory_order m) noexcept;
-
-template <class T>
-    void
-    atomic_store_explicit(atomic<T>* obj, T desr, memory_order m) noexcept;
-
-template <class T>
-    T
-    atomic_load(const volatile atomic<T>* obj) noexcept;
-
-template <class T>
-    T
-    atomic_load(const atomic<T>* obj) noexcept;
-
-template <class T>
-    T
-    atomic_load_explicit(const volatile atomic<T>* obj, memory_order m) noexcept;
-
-template <class T>
-    T
-    atomic_load_explicit(const atomic<T>* obj, memory_order m) noexcept;
-
-template <class T>
-    T
-    atomic_exchange(volatile atomic<T>* obj, T desr) noexcept;
-
-template <class T>
-    T
-    atomic_exchange(atomic<T>* obj, T desr) noexcept;
-
-template <class T>
-    T
-    atomic_exchange_explicit(volatile atomic<T>* obj, T desr, memory_order m) noexcept;
-
-template <class T>
-    T
-    atomic_exchange_explicit(atomic<T>* obj, T desr, memory_order m) noexcept;
-
-template <class T>
-    bool
-    atomic_compare_exchange_weak(volatile atomic<T>* obj, T* expc, T desr) noexcept;
-
-template <class T>
-    bool
-    atomic_compare_exchange_weak(atomic<T>* obj, T* expc, T desr) noexcept;
-
-template <class T>
-    bool
-    atomic_compare_exchange_strong(volatile atomic<T>* obj, T* expc, T desr) noexcept;
-
-template <class T>
-    bool
-    atomic_compare_exchange_strong(atomic<T>* obj, T* expc, T desr) noexcept;
-
-template <class T>
-    bool
-    atomic_compare_exchange_weak_explicit(volatile atomic<T>* obj, T* expc,
-                                          T desr,
-                                          memory_order s, memory_order f) noexcept;
-
-template <class T>
-    bool
-    atomic_compare_exchange_weak_explicit(atomic<T>* obj, T* expc, T desr,
-                                          memory_order s, memory_order f) noexcept;
-
-template <class T>
-    bool
-    atomic_compare_exchange_strong_explicit(volatile atomic<T>* obj,
-                                            T* expc, T desr,
-                                            memory_order s, memory_order f) noexcept;
-
-template <class T>
-    bool
-    atomic_compare_exchange_strong_explicit(atomic<T>* obj, T* expc,
-                                            T desr,
-                                            memory_order s, memory_order f) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_add(volatile atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_add(atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_add_explicit(volatile atomic<Integral>* obj, Integral op,
-                              memory_order m) noexcept;
-template <class Integral>
-    Integral
-    atomic_fetch_add_explicit(atomic<Integral>* obj, Integral op,
-                              memory_order m) noexcept;
-template <class Integral>
-    Integral
-    atomic_fetch_sub(volatile atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_sub(atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_sub_explicit(volatile atomic<Integral>* obj, Integral op,
-                              memory_order m) noexcept;
-template <class Integral>
-    Integral
-    atomic_fetch_sub_explicit(atomic<Integral>* obj, Integral op,
-                              memory_order m) noexcept;
-template <class Integral>
-    Integral
-    atomic_fetch_and(volatile atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_and(atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_and_explicit(volatile atomic<Integral>* obj, Integral op,
-                              memory_order m) noexcept;
-template <class Integral>
-    Integral
-    atomic_fetch_and_explicit(atomic<Integral>* obj, Integral op,
-                              memory_order m) noexcept;
-template <class Integral>
-    Integral
-    atomic_fetch_or(volatile atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_or(atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_or_explicit(volatile atomic<Integral>* obj, Integral op,
-                             memory_order m) noexcept;
-template <class Integral>
-    Integral
-    atomic_fetch_or_explicit(atomic<Integral>* obj, Integral op,
-                             memory_order m) noexcept;
-template <class Integral>
-    Integral
-    atomic_fetch_xor(volatile atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_xor(atomic<Integral>* obj, Integral op) noexcept;
-
-template <class Integral>
-    Integral
-    atomic_fetch_xor_explicit(volatile atomic<Integral>* obj, Integral op,
-                              memory_order m) noexcept;
-template <class Integral>
-    Integral
-    atomic_fetch_xor_explicit(atomic<Integral>* obj, Integral op,
-                              memory_order m) noexcept;
-
-template <class T>
-    T*
-    atomic_fetch_add(volatile atomic<T*>* obj, ptrdiff_t op) noexcept;
-
-template <class T>
-    T*
-    atomic_fetch_add(atomic<T*>* obj, ptrdiff_t op) noexcept;
-
-template <class T>
-    T*
-    atomic_fetch_add_explicit(volatile atomic<T*>* obj, ptrdiff_t op,
-                              memory_order m) noexcept;
-template <class T>
-    T*
-    atomic_fetch_add_explicit(atomic<T*>* obj, ptrdiff_t op, memory_order m) noexcept;
-
-template <class T>
-    T*
-    atomic_fetch_sub(volatile atomic<T*>* obj, ptrdiff_t op) noexcept;
-
-template <class T>
-    T*
-    atomic_fetch_sub(atomic<T*>* obj, ptrdiff_t op) noexcept;
-
-template <class T>
-    T*
-    atomic_fetch_sub_explicit(volatile atomic<T*>* obj, ptrdiff_t op,
-                              memory_order m) noexcept;
-template <class T>
-    T*
-    atomic_fetch_sub_explicit(atomic<T*>* obj, ptrdiff_t op, memory_order m) noexcept;
-
-// Atomics for standard typedef types
-
-typedef atomic<bool>               atomic_bool;
-typedef atomic<char>               atomic_char;
-typedef atomic<signed char>        atomic_schar;
-typedef atomic<unsigned char>      atomic_uchar;
-typedef atomic<short>              atomic_short;
-typedef atomic<unsigned short>     atomic_ushort;
-typedef atomic<int>                atomic_int;
-typedef atomic<unsigned int>       atomic_uint;
-typedef atomic<long>               atomic_long;
-typedef atomic<unsigned long>      atomic_ulong;
-typedef atomic<long long>          atomic_llong;
-typedef atomic<unsigned long long> atomic_ullong;
-typedef atomic<char16_t>           atomic_char16_t;
-typedef atomic<char32_t>           atomic_char32_t;
-typedef atomic<wchar_t>            atomic_wchar_t;
-
-typedef atomic<int_least8_t>   atomic_int_least8_t;
-typedef atomic<uint_least8_t>  atomic_uint_least8_t;
-typedef atomic<int_least16_t>  atomic_int_least16_t;
-typedef atomic<uint_least16_t> atomic_uint_least16_t;
-typedef atomic<int_least32_t>  atomic_int_least32_t;
-typedef atomic<uint_least32_t> atomic_uint_least32_t;
-typedef atomic<int_least64_t>  atomic_int_least64_t;
-typedef atomic<uint_least64_t> atomic_uint_least64_t;
-
-typedef atomic<int_fast8_t>   atomic_int_fast8_t;
-typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
-typedef atomic<int_fast16_t>  atomic_int_fast16_t;
-typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
-typedef atomic<int_fast32_t>  atomic_int_fast32_t;
-typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
-typedef atomic<int_fast64_t>  atomic_int_fast64_t;
-typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
-
-typedef atomic<int8_t>   atomic_int8_t;
-typedef atomic<uint8_t>  atomic_uint8_t;
-typedef atomic<int16_t>  atomic_int16_t;
-typedef atomic<uint16_t> atomic_uint16_t;
-typedef atomic<int32_t>  atomic_int32_t;
-typedef atomic<uint32_t> atomic_uint32_t;
-typedef atomic<int64_t>  atomic_int64_t;
-typedef atomic<uint64_t> atomic_uint64_t;
-
-typedef atomic<intptr_t>  atomic_intptr_t;
-typedef atomic<uintptr_t> atomic_uintptr_t;
-typedef atomic<size_t>    atomic_size_t;
-typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
-typedef atomic<intmax_t>  atomic_intmax_t;
-typedef atomic<uintmax_t> atomic_uintmax_t;
-
-// fences
-
-void atomic_thread_fence(memory_order m) noexcept;
-void atomic_signal_fence(memory_order m) noexcept;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <cstddef>
-#include <cstdint>
-#include <type_traits>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef _LIBCPP_HAS_NO_THREADS
-#error <atomic> is not supported on this single threaded system
-#endif
-#if !defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_GCC_ATOMIC_IMP)
-#error <atomic> is not implemented
-#endif
-#ifdef kill_dependency
-#error C++ standard library is incompatible with <stdatomic.h>
-#endif
-
-#define _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m) \
-  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_consume || \
-                           __m == memory_order_acquire || \
-                           __m == memory_order_acq_rel,   \
-                        "memory order argument to atomic operation is invalid")
-
-#define _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m) \
-  _LIBCPP_DIAGNOSE_WARNING(__m == memory_order_release || \
-                           __m == memory_order_acq_rel,   \
-                        "memory order argument to atomic operation is invalid")
-
-#define _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__m, __f) \
-  _LIBCPP_DIAGNOSE_WARNING(__f == memory_order_release || \
-                           __f == memory_order_acq_rel,   \
-                        "memory order argument to atomic operation is invalid")
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-typedef enum memory_order
-{
-    memory_order_relaxed, memory_order_consume, memory_order_acquire,
-    memory_order_release, memory_order_acq_rel, memory_order_seq_cst
-} memory_order;
-
-#if defined(_LIBCPP_HAS_GCC_ATOMIC_IMP)
-namespace __gcc_atomic {
-template <typename _Tp>
-struct __gcc_atomic_t {
-
-#if _GNUC_VER >= 501
-    static_assert(is_trivially_copyable<_Tp>::value,
-      "std::atomic<Tp> requires that 'Tp' be a trivially copyable type");
-#endif
-
-  _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_CXX03_LANG
-    __gcc_atomic_t() _NOEXCEPT = default;
-#else
-    __gcc_atomic_t() _NOEXCEPT : __a_value() {}
-#endif // _LIBCPP_CXX03_LANG
-  _LIBCPP_CONSTEXPR explicit __gcc_atomic_t(_Tp value) _NOEXCEPT
-    : __a_value(value) {}
-  _Tp __a_value;
-};
-#define _Atomic(x) __gcc_atomic::__gcc_atomic_t<x>
-
-template <typename _Tp> _Tp __create();
-
-template <typename _Tp, typename _Td>
-typename enable_if<sizeof(_Tp()->__a_value = __create<_Td>()), char>::type
-    __test_atomic_assignable(int);
-template <typename _Tp, typename _Up>
-__two __test_atomic_assignable(...);
-
-template <typename _Tp, typename _Td>
-struct __can_assign {
-  static const bool value =
-      sizeof(__test_atomic_assignable<_Tp, _Td>(1)) == sizeof(char);
-};
-
-static inline _LIBCPP_CONSTEXPR int __to_gcc_order(memory_order __order) {
-  // Avoid switch statement to make this a constexpr.
-  return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
-         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
-          (__order == memory_order_release ? __ATOMIC_RELEASE:
-           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
-            (__order == memory_order_acq_rel ? __ATOMIC_ACQ_REL:
-              __ATOMIC_CONSUME))));
-}
-
-static inline _LIBCPP_CONSTEXPR int __to_gcc_failure_order(memory_order __order) {
-  // Avoid switch statement to make this a constexpr.
-  return __order == memory_order_relaxed ? __ATOMIC_RELAXED:
-         (__order == memory_order_acquire ? __ATOMIC_ACQUIRE:
-          (__order == memory_order_release ? __ATOMIC_RELAXED:
-           (__order == memory_order_seq_cst ? __ATOMIC_SEQ_CST:
-            (__order == memory_order_acq_rel ? __ATOMIC_ACQUIRE:
-              __ATOMIC_CONSUME))));
-}
-
-} // namespace __gcc_atomic
-
-template <typename _Tp>
-static inline
-typename enable_if<
-    __gcc_atomic::__can_assign<volatile _Atomic(_Tp)*, _Tp>::value>::type
-__c11_atomic_init(volatile _Atomic(_Tp)* __a,  _Tp __val) {
-  __a->__a_value = __val;
-}
-
-template <typename _Tp>
-static inline
-typename enable_if<
-    !__gcc_atomic::__can_assign<volatile _Atomic(_Tp)*, _Tp>::value &&
-     __gcc_atomic::__can_assign<         _Atomic(_Tp)*, _Tp>::value>::type
-__c11_atomic_init(volatile _Atomic(_Tp)* __a,  _Tp __val) {
-  // [atomics.types.generic]p1 guarantees _Tp is trivially copyable. Because
-  // the default operator= in an object is not volatile, a byte-by-byte copy
-  // is required.
-  volatile char* to = reinterpret_cast<volatile char*>(&__a->__a_value);
-  volatile char* end = to + sizeof(_Tp);
-  char* from = reinterpret_cast<char*>(&__val);
-  while (to != end) {
-    *to++ = *from++;
-  }
-}
-
-template <typename _Tp>
-static inline void __c11_atomic_init(_Atomic(_Tp)* __a,  _Tp __val) {
-  __a->__a_value = __val;
-}
-
-static inline void __c11_atomic_thread_fence(memory_order __order) {
-  __atomic_thread_fence(__gcc_atomic::__to_gcc_order(__order));
-}
-
-static inline void __c11_atomic_signal_fence(memory_order __order) {
-  __atomic_signal_fence(__gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-static inline void __c11_atomic_store(volatile _Atomic(_Tp)* __a,  _Tp __val,
-                                      memory_order __order) {
-  return __atomic_store(&__a->__a_value, &__val,
-                        __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-static inline void __c11_atomic_store(_Atomic(_Tp)* __a,  _Tp __val,
-                                      memory_order __order) {
-  __atomic_store(&__a->__a_value, &__val,
-                 __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_load(const volatile _Atomic(_Tp)* __a,
-                                    memory_order __order) {
-  _Tp __ret;
-  __atomic_load(&__a->__a_value, &__ret,
-                __gcc_atomic::__to_gcc_order(__order));
-  return __ret;
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_load(const _Atomic(_Tp)* __a, memory_order __order) {
-  _Tp __ret;
-  __atomic_load(&__a->__a_value, &__ret,
-                __gcc_atomic::__to_gcc_order(__order));
-  return __ret;
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_exchange(volatile _Atomic(_Tp)* __a,
-                                        _Tp __value, memory_order __order) {
-  _Tp __ret;
-  __atomic_exchange(&__a->__a_value, &__value, &__ret,
-                    __gcc_atomic::__to_gcc_order(__order));
-  return __ret;
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_exchange(_Atomic(_Tp)* __a, _Tp __value,
-                                        memory_order __order) {
-  _Tp __ret;
-  __atomic_exchange(&__a->__a_value, &__value, &__ret,
-                    __gcc_atomic::__to_gcc_order(__order));
-  return __ret;
-}
-
-template <typename _Tp>
-static inline bool __c11_atomic_compare_exchange_strong(
-    volatile _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value,
-    memory_order __success, memory_order __failure) {
-  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
-                                   false,
-                                   __gcc_atomic::__to_gcc_order(__success),
-                                   __gcc_atomic::__to_gcc_failure_order(__failure));
-}
-
-template <typename _Tp>
-static inline bool __c11_atomic_compare_exchange_strong(
-    _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value, memory_order __success,
-    memory_order __failure) {
-  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
-                                   false,
-                                   __gcc_atomic::__to_gcc_order(__success),
-                                   __gcc_atomic::__to_gcc_failure_order(__failure));
-}
-
-template <typename _Tp>
-static inline bool __c11_atomic_compare_exchange_weak(
-    volatile _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value,
-    memory_order __success, memory_order __failure) {
-  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
-                                   true,
-                                   __gcc_atomic::__to_gcc_order(__success),
-                                   __gcc_atomic::__to_gcc_failure_order(__failure));
-}
-
-template <typename _Tp>
-static inline bool __c11_atomic_compare_exchange_weak(
-    _Atomic(_Tp)* __a, _Tp* __expected, _Tp __value, memory_order __success,
-    memory_order __failure) {
-  return __atomic_compare_exchange(&__a->__a_value, __expected, &__value,
-                                   true,
-                                   __gcc_atomic::__to_gcc_order(__success),
-                                   __gcc_atomic::__to_gcc_failure_order(__failure));
-}
-
-template <typename _Tp>
-struct __skip_amt { enum {value = 1}; };
-
-template <typename _Tp>
-struct __skip_amt<_Tp*> { enum {value = sizeof(_Tp)}; };
-
-// FIXME: Haven't figured out what the spec says about using arrays with
-// atomic_fetch_add. Force a failure rather than creating bad behavior.
-template <typename _Tp>
-struct __skip_amt<_Tp[]> { };
-template <typename _Tp, int n>
-struct __skip_amt<_Tp[n]> { };
-
-template <typename _Tp, typename _Td>
-static inline _Tp __c11_atomic_fetch_add(volatile _Atomic(_Tp)* __a,
-                                         _Td __delta, memory_order __order) {
-  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
-                            __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp, typename _Td>
-static inline _Tp __c11_atomic_fetch_add(_Atomic(_Tp)* __a, _Td __delta,
-                                         memory_order __order) {
-  return __atomic_fetch_add(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
-                            __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp, typename _Td>
-static inline _Tp __c11_atomic_fetch_sub(volatile _Atomic(_Tp)* __a,
-                                         _Td __delta, memory_order __order) {
-  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
-                            __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp, typename _Td>
-static inline _Tp __c11_atomic_fetch_sub(_Atomic(_Tp)* __a, _Td __delta,
-                                         memory_order __order) {
-  return __atomic_fetch_sub(&__a->__a_value, __delta * __skip_amt<_Tp>::value,
-                            __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_fetch_and(volatile _Atomic(_Tp)* __a,
-                                         _Tp __pattern, memory_order __order) {
-  return __atomic_fetch_and(&__a->__a_value, __pattern,
-                            __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_fetch_and(_Atomic(_Tp)* __a,
-                                         _Tp __pattern, memory_order __order) {
-  return __atomic_fetch_and(&__a->__a_value, __pattern,
-                            __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_fetch_or(volatile _Atomic(_Tp)* __a,
-                                        _Tp __pattern, memory_order __order) {
-  return __atomic_fetch_or(&__a->__a_value, __pattern,
-                           __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_fetch_or(_Atomic(_Tp)* __a, _Tp __pattern,
-                                        memory_order __order) {
-  return __atomic_fetch_or(&__a->__a_value, __pattern,
-                           __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_fetch_xor(volatile _Atomic(_Tp)* __a,
-                                         _Tp __pattern, memory_order __order) {
-  return __atomic_fetch_xor(&__a->__a_value, __pattern,
-                            __gcc_atomic::__to_gcc_order(__order));
-}
-
-template <typename _Tp>
-static inline _Tp __c11_atomic_fetch_xor(_Atomic(_Tp)* __a, _Tp __pattern,
-                                         memory_order __order) {
-  return __atomic_fetch_xor(&__a->__a_value, __pattern,
-                            __gcc_atomic::__to_gcc_order(__order));
-}
-#endif // _LIBCPP_HAS_GCC_ATOMIC_IMP
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-kill_dependency(_Tp __y) _NOEXCEPT
-{
-    return __y;
-}
-
-#if defined(__CLANG_ATOMIC_BOOL_LOCK_FREE)
-# define ATOMIC_BOOL_LOCK_FREE      __CLANG_ATOMIC_BOOL_LOCK_FREE
-# define ATOMIC_CHAR_LOCK_FREE      __CLANG_ATOMIC_CHAR_LOCK_FREE
-# define ATOMIC_CHAR16_T_LOCK_FREE  __CLANG_ATOMIC_CHAR16_T_LOCK_FREE
-# define ATOMIC_CHAR32_T_LOCK_FREE  __CLANG_ATOMIC_CHAR32_T_LOCK_FREE
-# define ATOMIC_WCHAR_T_LOCK_FREE   __CLANG_ATOMIC_WCHAR_T_LOCK_FREE
-# define ATOMIC_SHORT_LOCK_FREE     __CLANG_ATOMIC_SHORT_LOCK_FREE
-# define ATOMIC_INT_LOCK_FREE       __CLANG_ATOMIC_INT_LOCK_FREE
-# define ATOMIC_LONG_LOCK_FREE      __CLANG_ATOMIC_LONG_LOCK_FREE
-# define ATOMIC_LLONG_LOCK_FREE     __CLANG_ATOMIC_LLONG_LOCK_FREE
-# define ATOMIC_POINTER_LOCK_FREE   __CLANG_ATOMIC_POINTER_LOCK_FREE
-#else
-# define ATOMIC_BOOL_LOCK_FREE      __GCC_ATOMIC_BOOL_LOCK_FREE
-# define ATOMIC_CHAR_LOCK_FREE      __GCC_ATOMIC_CHAR_LOCK_FREE
-# define ATOMIC_CHAR16_T_LOCK_FREE  __GCC_ATOMIC_CHAR16_T_LOCK_FREE
-# define ATOMIC_CHAR32_T_LOCK_FREE  __GCC_ATOMIC_CHAR32_T_LOCK_FREE
-# define ATOMIC_WCHAR_T_LOCK_FREE   __GCC_ATOMIC_WCHAR_T_LOCK_FREE
-# define ATOMIC_SHORT_LOCK_FREE     __GCC_ATOMIC_SHORT_LOCK_FREE
-# define ATOMIC_INT_LOCK_FREE       __GCC_ATOMIC_INT_LOCK_FREE
-# define ATOMIC_LONG_LOCK_FREE      __GCC_ATOMIC_LONG_LOCK_FREE
-# define ATOMIC_LLONG_LOCK_FREE     __GCC_ATOMIC_LLONG_LOCK_FREE
-# define ATOMIC_POINTER_LOCK_FREE   __GCC_ATOMIC_POINTER_LOCK_FREE
-#endif
-
-// general atomic<T>
-
-template <class _Tp, bool = is_integral<_Tp>::value && !is_same<_Tp, bool>::value>
-struct __atomic_base  // false
-{
-    mutable _Atomic(_Tp) __a_;
-
-#if defined(__cpp_lib_atomic_is_always_lock_free)
-  static _LIBCPP_CONSTEXPR bool is_always_lock_free = __atomic_always_lock_free(sizeof(__a_), 0);
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool is_lock_free() const volatile _NOEXCEPT
-    {
-#if defined(_LIBCPP_HAS_C_ATOMIC_IMP)
-    return __c11_atomic_is_lock_free(sizeof(_Tp));
-#else
-    return __atomic_is_lock_free(sizeof(_Tp), 0);
-#endif
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    bool is_lock_free() const _NOEXCEPT
-        {return static_cast<__atomic_base const volatile*>(this)->is_lock_free();}
-    _LIBCPP_INLINE_VISIBILITY
-    void store(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
-        {__c11_atomic_store(&__a_, __d, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    void store(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-      _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
-        {__c11_atomic_store(&__a_, __d, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp load(memory_order __m = memory_order_seq_cst) const volatile _NOEXCEPT
-      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-        {return __c11_atomic_load(&__a_, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp load(memory_order __m = memory_order_seq_cst) const _NOEXCEPT
-      _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-        {return __c11_atomic_load(&__a_, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    operator _Tp() const volatile _NOEXCEPT {return load();}
-    _LIBCPP_INLINE_VISIBILITY
-    operator _Tp() const _NOEXCEPT          {return load();}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __c11_atomic_exchange(&__a_, __d, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp exchange(_Tp __d, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_exchange(&__a_, __d, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_weak(_Tp& __e, _Tp __d,
-                               memory_order __s, memory_order __f) volatile _NOEXCEPT
-      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-        {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_weak(_Tp& __e, _Tp __d,
-                               memory_order __s, memory_order __f) _NOEXCEPT
-      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-        {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __s, __f);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_strong(_Tp& __e, _Tp __d,
-                                 memory_order __s, memory_order __f) volatile _NOEXCEPT
-      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-        {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_strong(_Tp& __e, _Tp __d,
-                                 memory_order __s, memory_order __f) _NOEXCEPT
-      _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-        {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __s, __f);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_weak(_Tp& __e, _Tp __d,
-                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_weak(_Tp& __e, _Tp __d,
-                               memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_compare_exchange_weak(&__a_, &__e, __d, __m, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_strong(_Tp& __e, _Tp __d,
-                              memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool compare_exchange_strong(_Tp& __e, _Tp __d,
-                                 memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_compare_exchange_strong(&__a_, &__e, __d, __m, __m);}
-
-    _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_CXX03_LANG
-    __atomic_base() _NOEXCEPT = default;
-#else
-    __atomic_base() _NOEXCEPT : __a_() {}
-#endif // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __a_(__d) {}
-#ifndef _LIBCPP_CXX03_LANG
-    __atomic_base(const __atomic_base&) = delete;
-    __atomic_base& operator=(const __atomic_base&) = delete;
-    __atomic_base& operator=(const __atomic_base&) volatile = delete;
-#else
-private:
-    __atomic_base(const __atomic_base&);
-    __atomic_base& operator=(const __atomic_base&);
-    __atomic_base& operator=(const __atomic_base&) volatile;
-#endif
-};
-
-#if defined(__cpp_lib_atomic_is_always_lock_free)
-template <class _Tp, bool __b>
-_LIBCPP_CONSTEXPR bool __atomic_base<_Tp, __b>::is_always_lock_free;
-#endif
-
-// atomic<Integral>
-
-template <class _Tp>
-struct __atomic_base<_Tp, true>
-    : public __atomic_base<_Tp, false>
-{
-    typedef __atomic_base<_Tp, false> __base;
-    _LIBCPP_INLINE_VISIBILITY
-    __atomic_base() _NOEXCEPT _LIBCPP_DEFAULT
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR __atomic_base(_Tp __d) _NOEXCEPT : __base(__d) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_add(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_sub(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __c11_atomic_fetch_and(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_and(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_fetch_and(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __c11_atomic_fetch_or(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_or(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_fetch_or(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __c11_atomic_fetch_xor(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp fetch_xor(_Tp __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_fetch_xor(&this->__a_, __op, __m);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator++(int) volatile _NOEXCEPT      {return fetch_add(_Tp(1));}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator++(int) _NOEXCEPT               {return fetch_add(_Tp(1));}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator--(int) volatile _NOEXCEPT      {return fetch_sub(_Tp(1));}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator--(int) _NOEXCEPT               {return fetch_sub(_Tp(1));}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator++() volatile _NOEXCEPT         {return fetch_add(_Tp(1)) + _Tp(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator++() _NOEXCEPT                  {return fetch_add(_Tp(1)) + _Tp(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator--() volatile _NOEXCEPT         {return fetch_sub(_Tp(1)) - _Tp(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator--() _NOEXCEPT                  {return fetch_sub(_Tp(1)) - _Tp(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator+=(_Tp __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator+=(_Tp __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator-=(_Tp __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator-=(_Tp __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator&=(_Tp __op) volatile _NOEXCEPT {return fetch_and(__op) & __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator&=(_Tp __op) _NOEXCEPT          {return fetch_and(__op) & __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator|=(_Tp __op) volatile _NOEXCEPT {return fetch_or(__op) | __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator|=(_Tp __op) _NOEXCEPT          {return fetch_or(__op) | __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator^=(_Tp __op) volatile _NOEXCEPT {return fetch_xor(__op) ^ __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator^=(_Tp __op) _NOEXCEPT          {return fetch_xor(__op) ^ __op;}
-};
-
-// atomic<T>
-
-template <class _Tp>
-struct atomic
-    : public __atomic_base<_Tp>
-{
-    typedef __atomic_base<_Tp> __base;
-    _LIBCPP_INLINE_VISIBILITY
-    atomic() _NOEXCEPT _LIBCPP_DEFAULT
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR atomic(_Tp __d) _NOEXCEPT : __base(__d) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator=(_Tp __d) volatile _NOEXCEPT
-        {__base::store(__d); return __d;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator=(_Tp __d) _NOEXCEPT
-        {__base::store(__d); return __d;}
-};
-
-// atomic<T*>
-
-template <class _Tp>
-struct atomic<_Tp*>
-    : public __atomic_base<_Tp*>
-{
-    typedef __atomic_base<_Tp*> __base;
-    _LIBCPP_INLINE_VISIBILITY
-    atomic() _NOEXCEPT _LIBCPP_DEFAULT
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR atomic(_Tp* __d) _NOEXCEPT : __base(__d) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator=(_Tp* __d) volatile _NOEXCEPT
-        {__base::store(__d); return __d;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator=(_Tp* __d) _NOEXCEPT
-        {__base::store(__d); return __d;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst)
-                                                                        volatile _NOEXCEPT
-        {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* fetch_add(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_fetch_add(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst)
-                                                                        volatile _NOEXCEPT
-        {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* fetch_sub(ptrdiff_t __op, memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_fetch_sub(&this->__a_, __op, __m);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator++(int) volatile _NOEXCEPT            {return fetch_add(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator++(int) _NOEXCEPT                     {return fetch_add(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator--(int) volatile _NOEXCEPT            {return fetch_sub(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator--(int) _NOEXCEPT                     {return fetch_sub(1);}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator++() volatile _NOEXCEPT               {return fetch_add(1) + 1;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator++() _NOEXCEPT                        {return fetch_add(1) + 1;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator--() volatile _NOEXCEPT               {return fetch_sub(1) - 1;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator--() _NOEXCEPT                        {return fetch_sub(1) - 1;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator+=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_add(__op) + __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator+=(ptrdiff_t __op) _NOEXCEPT          {return fetch_add(__op) + __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator-=(ptrdiff_t __op) volatile _NOEXCEPT {return fetch_sub(__op) - __op;}
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* operator-=(ptrdiff_t __op) _NOEXCEPT          {return fetch_sub(__op) - __op;}
-};
-
-// atomic_is_lock_free
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_is_lock_free(const volatile atomic<_Tp>* __o) _NOEXCEPT
-{
-    return __o->is_lock_free();
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_is_lock_free(const atomic<_Tp>* __o) _NOEXCEPT
-{
-    return __o->is_lock_free();
-}
-
-// atomic_init
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_init(volatile atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
-{
-    __c11_atomic_init(&__o->__a_, __d);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_init(atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
-{
-    __c11_atomic_init(&__o->__a_, __d);
-}
-
-// atomic_store
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_store(volatile atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
-{
-    __o->store(__d);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_store(atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
-{
-    __o->store(__d);
-}
-
-// atomic_store_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_store_explicit(volatile atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
-{
-    __o->store(__d, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_store_explicit(atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_STORE_MEMORY_ORDER(__m)
-{
-    __o->store(__d, __m);
-}
-
-// atomic_load
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_load(const volatile atomic<_Tp>* __o) _NOEXCEPT
-{
-    return __o->load();
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_load(const atomic<_Tp>* __o) _NOEXCEPT
-{
-    return __o->load();
-}
-
-// atomic_load_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_load_explicit(const volatile atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-{
-    return __o->load(__m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_load_explicit(const atomic<_Tp>* __o, memory_order __m) _NOEXCEPT
-  _LIBCPP_CHECK_LOAD_MEMORY_ORDER(__m)
-{
-    return __o->load(__m);
-}
-
-// atomic_exchange
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_exchange(volatile atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
-{
-    return __o->exchange(__d);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_exchange(atomic<_Tp>* __o, _Tp __d) _NOEXCEPT
-{
-    return __o->exchange(__d);
-}
-
-// atomic_exchange_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_exchange_explicit(volatile atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
-{
-    return __o->exchange(__d, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-atomic_exchange_explicit(atomic<_Tp>* __o, _Tp __d, memory_order __m) _NOEXCEPT
-{
-    return __o->exchange(__d, __m);
-}
-
-// atomic_compare_exchange_weak
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_weak(volatile atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
-{
-    return __o->compare_exchange_weak(*__e, __d);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_weak(atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
-{
-    return __o->compare_exchange_weak(*__e, __d);
-}
-
-// atomic_compare_exchange_strong
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_strong(volatile atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
-{
-    return __o->compare_exchange_strong(*__e, __d);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_strong(atomic<_Tp>* __o, _Tp* __e, _Tp __d) _NOEXCEPT
-{
-    return __o->compare_exchange_strong(*__e, __d);
-}
-
-// atomic_compare_exchange_weak_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_weak_explicit(volatile atomic<_Tp>* __o, _Tp* __e,
-                                      _Tp __d,
-                                      memory_order __s, memory_order __f) _NOEXCEPT
-  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-{
-    return __o->compare_exchange_weak(*__e, __d, __s, __f);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_weak_explicit(atomic<_Tp>* __o, _Tp* __e, _Tp __d,
-                                      memory_order __s, memory_order __f) _NOEXCEPT
-  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-{
-    return __o->compare_exchange_weak(*__e, __d, __s, __f);
-}
-
-// atomic_compare_exchange_strong_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_strong_explicit(volatile atomic<_Tp>* __o,
-                                        _Tp* __e, _Tp __d,
-                                        memory_order __s, memory_order __f) _NOEXCEPT
-  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-{
-    return __o->compare_exchange_strong(*__e, __d, __s, __f);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_compare_exchange_strong_explicit(atomic<_Tp>* __o, _Tp* __e,
-                                        _Tp __d,
-                                        memory_order __s, memory_order __f) _NOEXCEPT
-  _LIBCPP_CHECK_EXCHANGE_MEMORY_ORDER(__s, __f)
-{
-    return __o->compare_exchange_strong(*__e, __d, __s, __f);
-}
-
-// atomic_fetch_add
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_add(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_add(__op);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_add(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_add(__op);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-atomic_fetch_add(volatile atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
-{
-    return __o->fetch_add(__op);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-atomic_fetch_add(atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
-{
-    return __o->fetch_add(__op);
-}
-
-// atomic_fetch_add_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_add_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_add(__op, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_add_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_add(__op, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-atomic_fetch_add_explicit(volatile atomic<_Tp*>* __o, ptrdiff_t __op,
-                          memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_add(__op, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-atomic_fetch_add_explicit(atomic<_Tp*>* __o, ptrdiff_t __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_add(__op, __m);
-}
-
-// atomic_fetch_sub
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_sub(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_sub(__op);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_sub(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_sub(__op);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-atomic_fetch_sub(volatile atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
-{
-    return __o->fetch_sub(__op);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-atomic_fetch_sub(atomic<_Tp*>* __o, ptrdiff_t __op) _NOEXCEPT
-{
-    return __o->fetch_sub(__op);
-}
-
-// atomic_fetch_sub_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_sub_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_sub(__op, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_sub_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_sub(__op, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-atomic_fetch_sub_explicit(volatile atomic<_Tp*>* __o, ptrdiff_t __op,
-                          memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_sub(__op, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-atomic_fetch_sub_explicit(atomic<_Tp*>* __o, ptrdiff_t __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_sub(__op, __m);
-}
-
-// atomic_fetch_and
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_and(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_and(__op);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_and(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_and(__op);
-}
-
-// atomic_fetch_and_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_and_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_and(__op, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_and_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_and(__op, __m);
-}
-
-// atomic_fetch_or
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_or(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_or(__op);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_or(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_or(__op);
-}
-
-// atomic_fetch_or_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_or_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_or(__op, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_or_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_or(__op, __m);
-}
-
-// atomic_fetch_xor
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_xor(volatile atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_xor(__op);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_xor(atomic<_Tp>* __o, _Tp __op) _NOEXCEPT
-{
-    return __o->fetch_xor(__op);
-}
-
-// atomic_fetch_xor_explicit
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_xor_explicit(volatile atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_xor(__op, __m);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value && !is_same<_Tp, bool>::value,
-    _Tp
->::type
-atomic_fetch_xor_explicit(atomic<_Tp>* __o, _Tp __op, memory_order __m) _NOEXCEPT
-{
-    return __o->fetch_xor(__op, __m);
-}
-
-// flag type and operations
-
-typedef struct atomic_flag
-{
-    _Atomic(bool) __a_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool test_and_set(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {return __c11_atomic_exchange(&__a_, true, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool test_and_set(memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {return __c11_atomic_exchange(&__a_, true, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear(memory_order __m = memory_order_seq_cst) volatile _NOEXCEPT
-        {__c11_atomic_store(&__a_, false, __m);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear(memory_order __m = memory_order_seq_cst) _NOEXCEPT
-        {__c11_atomic_store(&__a_, false, __m);}
-
-    _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_CXX03_LANG
-    atomic_flag() _NOEXCEPT = default;
-#else
-    atomic_flag() _NOEXCEPT : __a_() {}
-#endif // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    atomic_flag(bool __b) _NOEXCEPT : __a_(__b) {} // EXTENSION
-
-#ifndef _LIBCPP_CXX03_LANG
-    atomic_flag(const atomic_flag&) = delete;
-    atomic_flag& operator=(const atomic_flag&) = delete;
-    atomic_flag& operator=(const atomic_flag&) volatile = delete;
-#else
-private:
-    atomic_flag(const atomic_flag&);
-    atomic_flag& operator=(const atomic_flag&);
-    atomic_flag& operator=(const atomic_flag&) volatile;
-#endif
-} atomic_flag;
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_and_set(volatile atomic_flag* __o) _NOEXCEPT
-{
-    return __o->test_and_set();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_and_set(atomic_flag* __o) _NOEXCEPT
-{
-    return __o->test_and_set();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_and_set_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    return __o->test_and_set(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_flag_test_and_set_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    return __o->test_and_set(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_flag_clear(volatile atomic_flag* __o) _NOEXCEPT
-{
-    __o->clear();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_flag_clear(atomic_flag* __o) _NOEXCEPT
-{
-    __o->clear();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_flag_clear_explicit(volatile atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    __o->clear(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_flag_clear_explicit(atomic_flag* __o, memory_order __m) _NOEXCEPT
-{
-    __o->clear(__m);
-}
-
-// fences
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_thread_fence(memory_order __m) _NOEXCEPT
-{
-    __c11_atomic_thread_fence(__m);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-atomic_signal_fence(memory_order __m) _NOEXCEPT
-{
-    __c11_atomic_signal_fence(__m);
-}
-
-// Atomics for standard typedef types
-
-typedef atomic<bool>               atomic_bool;
-typedef atomic<char>               atomic_char;
-typedef atomic<signed char>        atomic_schar;
-typedef atomic<unsigned char>      atomic_uchar;
-typedef atomic<short>              atomic_short;
-typedef atomic<unsigned short>     atomic_ushort;
-typedef atomic<int>                atomic_int;
-typedef atomic<unsigned int>       atomic_uint;
-typedef atomic<long>               atomic_long;
-typedef atomic<unsigned long>      atomic_ulong;
-typedef atomic<long long>          atomic_llong;
-typedef atomic<unsigned long long> atomic_ullong;
-typedef atomic<char16_t>           atomic_char16_t;
-typedef atomic<char32_t>           atomic_char32_t;
-typedef atomic<wchar_t>            atomic_wchar_t;
-
-typedef atomic<int_least8_t>   atomic_int_least8_t;
-typedef atomic<uint_least8_t>  atomic_uint_least8_t;
-typedef atomic<int_least16_t>  atomic_int_least16_t;
-typedef atomic<uint_least16_t> atomic_uint_least16_t;
-typedef atomic<int_least32_t>  atomic_int_least32_t;
-typedef atomic<uint_least32_t> atomic_uint_least32_t;
-typedef atomic<int_least64_t>  atomic_int_least64_t;
-typedef atomic<uint_least64_t> atomic_uint_least64_t;
-
-typedef atomic<int_fast8_t>   atomic_int_fast8_t;
-typedef atomic<uint_fast8_t>  atomic_uint_fast8_t;
-typedef atomic<int_fast16_t>  atomic_int_fast16_t;
-typedef atomic<uint_fast16_t> atomic_uint_fast16_t;
-typedef atomic<int_fast32_t>  atomic_int_fast32_t;
-typedef atomic<uint_fast32_t> atomic_uint_fast32_t;
-typedef atomic<int_fast64_t>  atomic_int_fast64_t;
-typedef atomic<uint_fast64_t> atomic_uint_fast64_t;
-
-typedef atomic< int8_t>  atomic_int8_t;
-typedef atomic<uint8_t>  atomic_uint8_t;
-typedef atomic< int16_t> atomic_int16_t;
-typedef atomic<uint16_t> atomic_uint16_t;
-typedef atomic< int32_t> atomic_int32_t;
-typedef atomic<uint32_t> atomic_uint32_t;
-typedef atomic< int64_t> atomic_int64_t;
-typedef atomic<uint64_t> atomic_uint64_t;
-
-typedef atomic<intptr_t>  atomic_intptr_t;
-typedef atomic<uintptr_t> atomic_uintptr_t;
-typedef atomic<size_t>    atomic_size_t;
-typedef atomic<ptrdiff_t> atomic_ptrdiff_t;
-typedef atomic<intmax_t>  atomic_intmax_t;
-typedef atomic<uintmax_t> atomic_uintmax_t;
-
-#define ATOMIC_FLAG_INIT {false}
-#define ATOMIC_VAR_INIT(__v) {__v}
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_ATOMIC
diff --git a/lib/libcxx/include/bit b/lib/libcxx/include/bit
deleted file mode 100644
index db3812e5b5b..00000000000
--- a/lib/libcxx/include/bit
+++ /dev/null
@@ -1,158 +0,0 @@
-// -*- C++ -*-
-//===------------------------------ bit ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===---------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_BIT
-#define _LIBCPP_BIT
-
-/*
-    bit synopsis
-
-namespace std {
-
-} // namespace std
-
-*/
-
-#include <__config>
-#include <version>
-
-#if defined(__IBMCPP__)
-#include "support/ibm/support.h"
-#endif
-#if defined(_LIBCPP_COMPILER_MSVC)
-#include <intrin.h>
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#ifndef _LIBCPP_COMPILER_MSVC
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __ctz(unsigned __x)           { return __builtin_ctz(__x); }
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __ctz(unsigned long __x)      { return __builtin_ctzl(__x); }
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __ctz(unsigned long long __x) { return __builtin_ctzll(__x); }
-
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __clz(unsigned __x)           { return __builtin_clz(__x); }
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __clz(unsigned long __x)      { return __builtin_clzl(__x); }
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __clz(unsigned long long __x) { return __builtin_clzll(__x); }
-
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __popcount(unsigned __x)           { return __builtin_popcount(__x); }
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __popcount(unsigned long __x)      { return __builtin_popcountl(__x); }
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __popcount(unsigned long long __x) { return __builtin_popcountll(__x); }
-
-#else  // _LIBCPP_COMPILER_MSVC
-
-// Precondition:  __x != 0
-inline _LIBCPP_INLINE_VISIBILITY
-int __ctz(unsigned __x) {
-  static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
-  static_assert(sizeof(unsigned long) == 4, "");
-  unsigned long __where;
-  if (_BitScanForward(&__where, __x))
-    return static_cast<int>(__where);
-  return 32;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __ctz(unsigned long __x) {
-    static_assert(sizeof(unsigned long) == sizeof(unsigned), "");
-    return __ctz(static_cast<unsigned>(__x));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __ctz(unsigned long long __x) {
-    unsigned long __where;
-#if defined(_LIBCPP_HAS_BITSCAN64)
-    (defined(_M_AMD64) || defined(__x86_64__))
-  if (_BitScanForward64(&__where, __x))
-    return static_cast<int>(__where);
-#else
-  // Win32 doesn't have _BitScanForward64 so emulate it with two 32 bit calls.
-  if (_BitScanForward(&__where, static_cast<unsigned long>(__x)))
-    return static_cast<int>(__where);
-  if (_BitScanForward(&__where, static_cast<unsigned long>(__x >> 32)))
-    return static_cast<int>(__where + 32);
-#endif
-  return 64;
-}
-
-// Precondition:  __x != 0
-inline _LIBCPP_INLINE_VISIBILITY
-int __clz(unsigned __x) {
-  static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
-  static_assert(sizeof(unsigned long) == 4, "");
-  unsigned long __where;
-  if (_BitScanReverse(&__where, __x))
-    return static_cast<int>(31 - __where);
-  return 32; // Undefined Behavior.
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __clz(unsigned long __x) {
-    static_assert(sizeof(unsigned) == sizeof(unsigned long), "");
-    return __clz(static_cast<unsigned>(__x));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-int __clz(unsigned long long __x) {
-  unsigned long __where;
-#if defined(_LIBCPP_HAS_BITSCAN64)
-  if (_BitScanReverse64(&__where, __x))
-    return static_cast<int>(63 - __where);
-#else
-  // Win32 doesn't have _BitScanReverse64 so emulate it with two 32 bit calls.
-  if (_BitScanReverse(&__where, static_cast<unsigned long>(__x >> 32)))
-    return static_cast<int>(63 - (__where + 32));
-  if (_BitScanReverse(&__where, static_cast<unsigned long>(__x)))
-    return static_cast<int>(63 - __where);
-#endif
-  return 64; // Undefined Behavior.
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned __x) {
-  static_assert(sizeof(unsigned) == 4, "");
-  return __popcnt(__x);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned long __x) {
-  static_assert(sizeof(unsigned long) == 4, "");
-  return __popcnt(__x);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int __popcount(unsigned long long __x) {
-  static_assert(sizeof(unsigned long long) == 8, "");
-  return __popcnt64(__x);
-}
-
-#endif // _LIBCPP_COMPILER_MSVC
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP_BIT
diff --git a/lib/libcxx/include/bitset b/lib/libcxx/include/bitset
deleted file mode 100644
index 98947e027c1..00000000000
--- a/lib/libcxx/include/bitset
+++ /dev/null
@@ -1,1110 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- bitset ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_BITSET
-#define _LIBCPP_BITSET
-
-/*
-    bitset synopsis
-
-namespace std
-{
-
-namespace std {
-
-template <size_t N>
-class bitset
-{
-public:
-    // bit reference:
-    class reference
-    {
-        friend class bitset;
-        reference() noexcept;
-    public:
-        ~reference() noexcept;
-        reference& operator=(bool x) noexcept;           // for b[i] = x;
-        reference& operator=(const reference&) noexcept; // for b[i] = b[j];
-        bool operator~() const noexcept;                 // flips the bit
-        operator bool() const noexcept;                  // for x = b[i];
-        reference& flip() noexcept;                      // for b[i].flip();
-    };
-
-    // 23.3.5.1 constructors:
-    constexpr bitset() noexcept;
-    constexpr bitset(unsigned long long val) noexcept;
-    template <class charT>
-        explicit bitset(const charT* str,
-                        typename basic_string<charT>::size_type n = basic_string<charT>::npos,
-                        charT zero = charT('0'), charT one = charT('1'));
-    template<class charT, class traits, class Allocator>
-        explicit bitset(const basic_string<charT,traits,Allocator>& str,
-                        typename basic_string<charT,traits,Allocator>::size_type pos = 0,
-                        typename basic_string<charT,traits,Allocator>::size_type n =
-                                 basic_string<charT,traits,Allocator>::npos,
-                        charT zero = charT('0'), charT one = charT('1'));
-
-    // 23.3.5.2 bitset operations:
-    bitset& operator&=(const bitset& rhs) noexcept;
-    bitset& operator|=(const bitset& rhs) noexcept;
-    bitset& operator^=(const bitset& rhs) noexcept;
-    bitset& operator<<=(size_t pos) noexcept;
-    bitset& operator>>=(size_t pos) noexcept;
-    bitset& set() noexcept;
-    bitset& set(size_t pos, bool val = true);
-    bitset& reset() noexcept;
-    bitset& reset(size_t pos);
-    bitset operator~() const noexcept;
-    bitset& flip() noexcept;
-    bitset& flip(size_t pos);
-
-    // element access:
-    constexpr bool operator[](size_t pos) const; // for b[i];
-    reference operator[](size_t pos);            // for b[i];
-    unsigned long to_ulong() const;
-    unsigned long long to_ullong() const;
-    template <class charT, class traits, class Allocator>
-        basic_string<charT, traits, Allocator> to_string(charT zero = charT('0'), charT one = charT('1')) const;
-    template <class charT, class traits>
-        basic_string<charT, traits, allocator<charT> > to_string(charT zero = charT('0'), charT one = charT('1')) const;
-    template <class charT>
-        basic_string<charT, char_traits<charT>, allocator<charT> > to_string(charT zero = charT('0'), charT one = charT('1')) const;
-    basic_string<char, char_traits<char>, allocator<char> > to_string(char zero = '0', char one = '1') const;
-    size_t count() const noexcept;
-    constexpr size_t size() const noexcept;
-    bool operator==(const bitset& rhs) const noexcept;
-    bool operator!=(const bitset& rhs) const noexcept;
-    bool test(size_t pos) const;
-    bool all() const noexcept;
-    bool any() const noexcept;
-    bool none() const noexcept;
-    bitset operator<<(size_t pos) const noexcept;
-    bitset operator>>(size_t pos) const noexcept;
-};
-
-// 23.3.5.3 bitset operators:
-template <size_t N>
-bitset<N> operator&(const bitset<N>&, const bitset<N>&) noexcept;
-
-template <size_t N>
-bitset<N> operator|(const bitset<N>&, const bitset<N>&) noexcept;
-
-template <size_t N>
-bitset<N> operator^(const bitset<N>&, const bitset<N>&) noexcept;
-
-template <class charT, class traits, size_t N>
-basic_istream<charT, traits>&
-operator>>(basic_istream<charT, traits>& is, bitset<N>& x);
-
-template <class charT, class traits, size_t N>
-basic_ostream<charT, traits>&
-operator<<(basic_ostream<charT, traits>& os, const bitset<N>& x);
-
-template <size_t N> struct hash<std::bitset<N>>;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__bit_reference>
-#include <cstddef>
-#include <climits>
-#include <string>
-#include <stdexcept>
-#include <iosfwd>
-#include <__functional_base>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <size_t _N_words, size_t _Size>
-class __bitset;
-
-template <size_t _N_words, size_t _Size>
-struct __has_storage_type<__bitset<_N_words, _Size> >
-{
-    static const bool value = true;
-};
-
-template <size_t _N_words, size_t _Size>
-class __bitset
-{
-public:
-    typedef ptrdiff_t              difference_type;
-    typedef size_t                 size_type;
-    typedef size_type              __storage_type;
-protected:
-    typedef __bitset __self;
-    typedef       __storage_type*  __storage_pointer;
-    typedef const __storage_type*  __const_storage_pointer;
-    static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
-
-    friend class __bit_reference<__bitset>;
-    friend class __bit_const_reference<__bitset>;
-    friend class __bit_iterator<__bitset, false>;
-    friend class __bit_iterator<__bitset, true>;
-    friend struct __bit_array<__bitset>;
-
-    __storage_type __first_[_N_words];
-
-    typedef __bit_reference<__bitset>                  reference;
-    typedef __bit_const_reference<__bitset>            const_reference;
-    typedef __bit_iterator<__bitset, false>            iterator;
-    typedef __bit_iterator<__bitset, true>             const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR __bitset() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    explicit _LIBCPP_CONSTEXPR __bitset(unsigned long long __v) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t __pos) _NOEXCEPT
-        {return reference(__first_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR const_reference __make_ref(size_t __pos) const _NOEXCEPT
-        {return const_reference(__first_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos) _NOEXCEPT
-        {return iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const _NOEXCEPT
-        {return const_iterator(__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator&=(const __bitset& __v) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    void operator|=(const __bitset& __v) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    void operator^=(const __bitset& __v) _NOEXCEPT;
-
-    void flip() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY unsigned long to_ulong() const
-        {return to_ulong(integral_constant<bool, _Size < sizeof(unsigned long) * CHAR_BIT>());}
-    _LIBCPP_INLINE_VISIBILITY unsigned long long to_ullong() const
-        {return to_ullong(integral_constant<bool, _Size < sizeof(unsigned long long) * CHAR_BIT>());}
-
-    bool all() const _NOEXCEPT;
-    bool any() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_t __hash_code() const _NOEXCEPT;
-private:
-#ifdef _LIBCPP_CXX03_LANG
-    void __init(unsigned long long __v, false_type) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    void __init(unsigned long long __v, true_type) _NOEXCEPT;
-#endif  // _LIBCPP_CXX03_LANG
-    unsigned long to_ulong(false_type) const;
-    _LIBCPP_INLINE_VISIBILITY
-    unsigned long to_ulong(true_type) const;
-    unsigned long long to_ullong(false_type) const;
-    _LIBCPP_INLINE_VISIBILITY
-    unsigned long long to_ullong(true_type) const;
-    _LIBCPP_INLINE_VISIBILITY
-    unsigned long long to_ullong(true_type, false_type) const;
-    unsigned long long to_ullong(true_type, true_type) const;
-};
-
-template <size_t _N_words, size_t _Size>
-inline
-_LIBCPP_CONSTEXPR
-__bitset<_N_words, _Size>::__bitset() _NOEXCEPT
-#ifndef _LIBCPP_CXX03_LANG
-    : __first_{0}
-#endif
-{
-#ifdef _LIBCPP_CXX03_LANG
-    _VSTD::fill_n(__first_, _N_words, __storage_type(0));
-#endif
-}
-
-#ifdef _LIBCPP_CXX03_LANG
-
-template <size_t _N_words, size_t _Size>
-void
-__bitset<_N_words, _Size>::__init(unsigned long long __v, false_type) _NOEXCEPT
-{
-    __storage_type __t[sizeof(unsigned long long) / sizeof(__storage_type)];
-    size_t __sz = _Size;
-    for (size_t __i = 0; __i < sizeof(__t)/sizeof(__t[0]); ++__i, __v >>= __bits_per_word, __sz -= __bits_per_word )
-        if ( __sz < __bits_per_word)
-            __t[__i] = static_cast<__storage_type>(__v) & ( 1ULL << __sz ) - 1;
-        else
-            __t[__i] = static_cast<__storage_type>(__v);
-
-    _VSTD::copy(__t, __t + sizeof(__t)/sizeof(__t[0]), __first_);
-    _VSTD::fill(__first_ + sizeof(__t)/sizeof(__t[0]), __first_ + sizeof(__first_)/sizeof(__first_[0]),
-               __storage_type(0));
-}
-
-template <size_t _N_words, size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__bitset<_N_words, _Size>::__init(unsigned long long __v, true_type) _NOEXCEPT
-{
-    __first_[0] = __v;
-    if (_Size < __bits_per_word)
-        __first_[0] &= ( 1ULL << _Size ) - 1;
-
-    _VSTD::fill(__first_ + 1, __first_ + sizeof(__first_)/sizeof(__first_[0]), __storage_type(0));
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <size_t _N_words, size_t _Size>
-inline
-_LIBCPP_CONSTEXPR
-__bitset<_N_words, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
-#ifndef _LIBCPP_CXX03_LANG
-#if __SIZEOF_SIZE_T__ == 8
-    : __first_{__v}
-#elif __SIZEOF_SIZE_T__ == 4
-    : __first_{static_cast<__storage_type>(__v),
-                _Size >= 2 * __bits_per_word ? static_cast<__storage_type>(__v >> __bits_per_word)
-                : static_cast<__storage_type>((__v >> __bits_per_word) & (__storage_type(1) << (_Size - __bits_per_word)) - 1)}
-#else
-#error This constructor has not been ported to this platform
-#endif
-#endif
-{
-#ifdef _LIBCPP_CXX03_LANG
-    __init(__v, integral_constant<bool, sizeof(unsigned long long) == sizeof(__storage_type)>());
-#endif
-}
-
-template <size_t _N_words, size_t _Size>
-inline
-void
-__bitset<_N_words, _Size>::operator&=(const __bitset& __v) _NOEXCEPT
-{
-    for (size_type __i = 0; __i < _N_words; ++__i)
-        __first_[__i] &= __v.__first_[__i];
-}
-
-template <size_t _N_words, size_t _Size>
-inline
-void
-__bitset<_N_words, _Size>::operator|=(const __bitset& __v) _NOEXCEPT
-{
-    for (size_type __i = 0; __i < _N_words; ++__i)
-        __first_[__i] |= __v.__first_[__i];
-}
-
-template <size_t _N_words, size_t _Size>
-inline
-void
-__bitset<_N_words, _Size>::operator^=(const __bitset& __v) _NOEXCEPT
-{
-    for (size_type __i = 0; __i < _N_words; ++__i)
-        __first_[__i] ^= __v.__first_[__i];
-}
-
-template <size_t _N_words, size_t _Size>
-void
-__bitset<_N_words, _Size>::flip() _NOEXCEPT
-{
-    // do middle whole words
-    size_type __n = _Size;
-    __storage_pointer __p = __first_;
-    for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
-        *__p = ~*__p;
-    // do last partial word
-    if (__n > 0)
-    {
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        __storage_type __b = *__p & __m;
-        *__p &= ~__m;
-        *__p |= ~__b & __m;
-    }
-}
-
-template <size_t _N_words, size_t _Size>
-unsigned long
-__bitset<_N_words, _Size>::to_ulong(false_type) const
-{
-    const_iterator __e = __make_iter(_Size);
-    const_iterator __i = _VSTD::find(__make_iter(sizeof(unsigned long) * CHAR_BIT), __e, true);
-    if (__i != __e)
-        __throw_overflow_error("bitset to_ulong overflow error");
-
-    return __first_[0];
-}
-
-template <size_t _N_words, size_t _Size>
-inline
-unsigned long
-__bitset<_N_words, _Size>::to_ulong(true_type) const
-{
-    return __first_[0];
-}
-
-template <size_t _N_words, size_t _Size>
-unsigned long long
-__bitset<_N_words, _Size>::to_ullong(false_type) const
-{
-    const_iterator __e = __make_iter(_Size);
-    const_iterator __i = _VSTD::find(__make_iter(sizeof(unsigned long long) * CHAR_BIT), __e, true);
-    if (__i != __e)
-        __throw_overflow_error("bitset to_ullong overflow error");
-
-    return to_ullong(true_type());
-}
-
-template <size_t _N_words, size_t _Size>
-inline
-unsigned long long
-__bitset<_N_words, _Size>::to_ullong(true_type) const
-{
-    return to_ullong(true_type(), integral_constant<bool, sizeof(__storage_type) < sizeof(unsigned long long)>());
-}
-
-template <size_t _N_words, size_t _Size>
-inline
-unsigned long long
-__bitset<_N_words, _Size>::to_ullong(true_type, false_type) const
-{
-    return __first_[0];
-}
-
-template <size_t _N_words, size_t _Size>
-unsigned long long
-__bitset<_N_words, _Size>::to_ullong(true_type, true_type) const
-{
-    unsigned long long __r = __first_[0];
-    for (std::size_t __i = 1; __i < sizeof(unsigned long long) / sizeof(__storage_type); ++__i)
-        __r |= static_cast<unsigned long long>(__first_[__i]) << (sizeof(__storage_type) * CHAR_BIT);
-    return __r;
-}
-
-template <size_t _N_words, size_t _Size>
-bool
-__bitset<_N_words, _Size>::all() const _NOEXCEPT
-{
-    // do middle whole words
-    size_type __n = _Size;
-    __const_storage_pointer __p = __first_;
-    for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
-        if (~*__p)
-            return false;
-    // do last partial word
-    if (__n > 0)
-    {
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        if (~*__p & __m)
-            return false;
-    }
-    return true;
-}
-
-template <size_t _N_words, size_t _Size>
-bool
-__bitset<_N_words, _Size>::any() const _NOEXCEPT
-{
-    // do middle whole words
-    size_type __n = _Size;
-    __const_storage_pointer __p = __first_;
-    for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
-        if (*__p)
-            return true;
-    // do last partial word
-    if (__n > 0)
-    {
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        if (*__p & __m)
-            return true;
-    }
-    return false;
-}
-
-template <size_t _N_words, size_t _Size>
-inline
-size_t
-__bitset<_N_words, _Size>::__hash_code() const _NOEXCEPT
-{
-    size_t __h = 0;
-    for (size_type __i = 0; __i < _N_words; ++__i)
-        __h ^= __first_[__i];
-    return __h;
-}
-
-template <size_t _Size>
-class __bitset<1, _Size>
-{
-public:
-    typedef ptrdiff_t              difference_type;
-    typedef size_t                 size_type;
-    typedef size_type              __storage_type;
-protected:
-    typedef __bitset __self;
-    typedef       __storage_type*  __storage_pointer;
-    typedef const __storage_type*  __const_storage_pointer;
-    static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
-
-    friend class __bit_reference<__bitset>;
-    friend class __bit_const_reference<__bitset>;
-    friend class __bit_iterator<__bitset, false>;
-    friend class __bit_iterator<__bitset, true>;
-    friend struct __bit_array<__bitset>;
-
-    __storage_type __first_;
-
-    typedef __bit_reference<__bitset>                  reference;
-    typedef __bit_const_reference<__bitset>            const_reference;
-    typedef __bit_iterator<__bitset, false>            iterator;
-    typedef __bit_iterator<__bitset, true>             const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR __bitset() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    explicit _LIBCPP_CONSTEXPR __bitset(unsigned long long __v) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t __pos) _NOEXCEPT
-        {return reference(&__first_, __storage_type(1) << __pos);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR const_reference __make_ref(size_t __pos) const _NOEXCEPT
-        {return const_reference(&__first_, __storage_type(1) << __pos);}
-    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t __pos) _NOEXCEPT
-        {return iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t __pos) const _NOEXCEPT
-        {return const_iterator(&__first_ + __pos / __bits_per_word, __pos % __bits_per_word);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator&=(const __bitset& __v) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    void operator|=(const __bitset& __v) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    void operator^=(const __bitset& __v) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void flip() _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    unsigned long to_ulong() const;
-    _LIBCPP_INLINE_VISIBILITY
-    unsigned long long to_ullong() const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool all() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    bool any() const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t __hash_code() const _NOEXCEPT;
-};
-
-template <size_t _Size>
-inline
-_LIBCPP_CONSTEXPR
-__bitset<1, _Size>::__bitset() _NOEXCEPT
-    : __first_(0)
-{
-}
-
-template <size_t _Size>
-inline
-_LIBCPP_CONSTEXPR
-__bitset<1, _Size>::__bitset(unsigned long long __v) _NOEXCEPT
-    : __first_(
-        _Size == __bits_per_word ? static_cast<__storage_type>(__v)
-                                 : static_cast<__storage_type>(__v) & ((__storage_type(1) << _Size) - 1)
-    )
-{
-}
-
-template <size_t _Size>
-inline
-void
-__bitset<1, _Size>::operator&=(const __bitset& __v) _NOEXCEPT
-{
-    __first_ &= __v.__first_;
-}
-
-template <size_t _Size>
-inline
-void
-__bitset<1, _Size>::operator|=(const __bitset& __v) _NOEXCEPT
-{
-    __first_ |= __v.__first_;
-}
-
-template <size_t _Size>
-inline
-void
-__bitset<1, _Size>::operator^=(const __bitset& __v) _NOEXCEPT
-{
-    __first_ ^= __v.__first_;
-}
-
-template <size_t _Size>
-inline
-void
-__bitset<1, _Size>::flip() _NOEXCEPT
-{
-    __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
-    __first_ = ~__first_;
-    __first_ &= __m;
-}
-
-template <size_t _Size>
-inline
-unsigned long
-__bitset<1, _Size>::to_ulong() const
-{
-    return __first_;
-}
-
-template <size_t _Size>
-inline
-unsigned long long
-__bitset<1, _Size>::to_ullong() const
-{
-    return __first_;
-}
-
-template <size_t _Size>
-inline
-bool
-__bitset<1, _Size>::all() const _NOEXCEPT
-{
-    __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
-    return !(~__first_ & __m);
-}
-
-template <size_t _Size>
-inline
-bool
-__bitset<1, _Size>::any() const _NOEXCEPT
-{
-    __storage_type __m = ~__storage_type(0) >> (__bits_per_word - _Size);
-    return __first_ & __m;
-}
-
-template <size_t _Size>
-inline
-size_t
-__bitset<1, _Size>::__hash_code() const _NOEXCEPT
-{
-    return __first_;
-}
-
-template <>
-class __bitset<0, 0>
-{
-public:
-    typedef ptrdiff_t              difference_type;
-    typedef size_t                 size_type;
-    typedef size_type              __storage_type;
-protected:
-    typedef __bitset __self;
-    typedef       __storage_type*  __storage_pointer;
-    typedef const __storage_type*  __const_storage_pointer;
-    static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
-
-    friend class __bit_reference<__bitset>;
-    friend class __bit_const_reference<__bitset>;
-    friend class __bit_iterator<__bitset, false>;
-    friend class __bit_iterator<__bitset, true>;
-    friend struct __bit_array<__bitset>;
-
-    typedef __bit_reference<__bitset>                  reference;
-    typedef __bit_const_reference<__bitset>            const_reference;
-    typedef __bit_iterator<__bitset, false>            iterator;
-    typedef __bit_iterator<__bitset, true>             const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR __bitset() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    explicit _LIBCPP_CONSTEXPR __bitset(unsigned long long) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY reference __make_ref(size_t) _NOEXCEPT
-        {return reference(0, 1);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR const_reference __make_ref(size_t) const _NOEXCEPT
-        {return const_reference(0, 1);}
-    _LIBCPP_INLINE_VISIBILITY iterator __make_iter(size_t) _NOEXCEPT
-        {return iterator(0, 0);}
-    _LIBCPP_INLINE_VISIBILITY const_iterator __make_iter(size_t) const _NOEXCEPT
-        {return const_iterator(0, 0);}
-
-    _LIBCPP_INLINE_VISIBILITY void operator&=(const __bitset&) _NOEXCEPT {}
-    _LIBCPP_INLINE_VISIBILITY void operator|=(const __bitset&) _NOEXCEPT {}
-    _LIBCPP_INLINE_VISIBILITY void operator^=(const __bitset&) _NOEXCEPT {}
-
-    _LIBCPP_INLINE_VISIBILITY void flip() _NOEXCEPT {}
-
-    _LIBCPP_INLINE_VISIBILITY unsigned long to_ulong() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY unsigned long long to_ullong() const {return 0;}
-
-    _LIBCPP_INLINE_VISIBILITY bool all() const _NOEXCEPT {return true;}
-    _LIBCPP_INLINE_VISIBILITY bool any() const _NOEXCEPT {return false;}
-
-    _LIBCPP_INLINE_VISIBILITY size_t __hash_code() const _NOEXCEPT {return 0;}
-};
-
-inline
-_LIBCPP_CONSTEXPR
-__bitset<0, 0>::__bitset() _NOEXCEPT
-{
-}
-
-inline
-_LIBCPP_CONSTEXPR
-__bitset<0, 0>::__bitset(unsigned long long) _NOEXCEPT
-{
-}
-
-template <size_t _Size> class _LIBCPP_TEMPLATE_VIS bitset;
-template <size_t _Size> struct hash<bitset<_Size> >;
-
-template <size_t _Size>
-class _LIBCPP_TEMPLATE_VIS bitset
-    : private __bitset<_Size == 0 ? 0 : (_Size - 1) / (sizeof(size_t) * CHAR_BIT) + 1, _Size>
-{
-public:
-    static const unsigned __n_words = _Size == 0 ? 0 : (_Size - 1) / (sizeof(size_t) * CHAR_BIT) + 1;
-    typedef __bitset<__n_words, _Size> base;
-
-public:
-    typedef typename base::reference       reference;
-    typedef typename base::const_reference const_reference;
-
-    // 23.3.5.1 constructors:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR bitset() _NOEXCEPT {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-        bitset(unsigned long long __v) _NOEXCEPT : base(__v) {}
-    template<class _CharT>
-        explicit bitset(const _CharT* __str,
-                        typename basic_string<_CharT>::size_type __n = basic_string<_CharT>::npos,
-                        _CharT __zero = _CharT('0'), _CharT __one = _CharT('1'));
-    template<class _CharT, class _Traits, class _Allocator>
-        explicit bitset(const basic_string<_CharT,_Traits,_Allocator>& __str,
-                        typename basic_string<_CharT,_Traits,_Allocator>::size_type __pos = 0,
-                        typename basic_string<_CharT,_Traits,_Allocator>::size_type __n =
-                                (basic_string<_CharT,_Traits,_Allocator>::npos),
-                        _CharT __zero = _CharT('0'), _CharT __one = _CharT('1'));
-
-    // 23.3.5.2 bitset operations:
-    _LIBCPP_INLINE_VISIBILITY
-    bitset& operator&=(const bitset& __rhs) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    bitset& operator|=(const bitset& __rhs) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    bitset& operator^=(const bitset& __rhs) _NOEXCEPT;
-    bitset& operator<<=(size_t __pos) _NOEXCEPT;
-    bitset& operator>>=(size_t __pos) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    bitset& set() _NOEXCEPT;
-    bitset& set(size_t __pos, bool __val = true);
-    _LIBCPP_INLINE_VISIBILITY
-    bitset& reset() _NOEXCEPT;
-    bitset& reset(size_t __pos);
-    _LIBCPP_INLINE_VISIBILITY
-    bitset  operator~() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    bitset& flip() _NOEXCEPT;
-    bitset& flip(size_t __pos);
-
-    // element access:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-                              const_reference operator[](size_t __p) const {return base::__make_ref(__p);}
-    _LIBCPP_INLINE_VISIBILITY       reference operator[](size_t __p)       {return base::__make_ref(__p);}
-    _LIBCPP_INLINE_VISIBILITY
-    unsigned long to_ulong() const;
-    _LIBCPP_INLINE_VISIBILITY
-    unsigned long long to_ullong() const;
-    template <class _CharT, class _Traits, class _Allocator>
-        basic_string<_CharT, _Traits, _Allocator> to_string(_CharT __zero = _CharT('0'),
-                                                            _CharT __one = _CharT('1')) const;
-    template <class _CharT, class _Traits>
-        _LIBCPP_INLINE_VISIBILITY
-        basic_string<_CharT, _Traits, allocator<_CharT> > to_string(_CharT __zero = _CharT('0'),
-                                                                    _CharT __one = _CharT('1')) const;
-    template <class _CharT>
-        _LIBCPP_INLINE_VISIBILITY
-        basic_string<_CharT, char_traits<_CharT>, allocator<_CharT> > to_string(_CharT __zero = _CharT('0'),
-                                                                                _CharT __one = _CharT('1')) const;
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string<char, char_traits<char>, allocator<char> > to_string(char __zero = '0',
-                                                                      char __one = '1') const;
-    _LIBCPP_INLINE_VISIBILITY
-    size_t count() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR size_t size() const _NOEXCEPT {return _Size;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const bitset& __rhs) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const bitset& __rhs) const _NOEXCEPT;
-    bool test(size_t __pos) const;
-    _LIBCPP_INLINE_VISIBILITY
-    bool all() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    bool any() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY bool none() const _NOEXCEPT {return !any();}
-    _LIBCPP_INLINE_VISIBILITY
-    bitset operator<<(size_t __pos) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    bitset operator>>(size_t __pos) const _NOEXCEPT;
-
-private:
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t __hash_code() const _NOEXCEPT {return base::__hash_code();}
-
-    friend struct hash<bitset>;
-};
-
-template <size_t _Size>
-template<class _CharT>
-bitset<_Size>::bitset(const _CharT* __str,
-                      typename basic_string<_CharT>::size_type __n,
-                      _CharT __zero, _CharT __one)
-{
-    size_t __rlen = _VSTD::min(__n, char_traits<_CharT>::length(__str));
-    for (size_t __i = 0; __i < __rlen; ++__i)
-        if (__str[__i] != __zero && __str[__i] != __one)
-            __throw_invalid_argument("bitset string ctor has invalid argument");
-
-    size_t _Mp = _VSTD::min(__rlen, _Size);
-    size_t __i = 0;
-    for (; __i < _Mp; ++__i)
-    {
-        _CharT __c = __str[_Mp - 1 - __i];
-        if (__c == __zero)
-            (*this)[__i] = false;
-        else
-            (*this)[__i] = true;
-    }
-    _VSTD::fill(base::__make_iter(__i), base::__make_iter(_Size), false);
-}
-
-template <size_t _Size>
-template<class _CharT, class _Traits, class _Allocator>
-bitset<_Size>::bitset(const basic_string<_CharT,_Traits,_Allocator>& __str,
-       typename basic_string<_CharT,_Traits,_Allocator>::size_type __pos,
-       typename basic_string<_CharT,_Traits,_Allocator>::size_type __n,
-       _CharT __zero, _CharT __one)
-{
-    if (__pos > __str.size())
-        __throw_out_of_range("bitset string pos out of range");
-
-    size_t __rlen = _VSTD::min(__n, __str.size() - __pos);
-    for (size_t __i = __pos; __i < __pos + __rlen; ++__i)
-        if (!_Traits::eq(__str[__i], __zero) && !_Traits::eq(__str[__i], __one))
-            __throw_invalid_argument("bitset string ctor has invalid argument");
-
-    size_t _Mp = _VSTD::min(__rlen, _Size);
-    size_t __i = 0;
-    for (; __i < _Mp; ++__i)
-    {
-        _CharT __c = __str[__pos + _Mp - 1 - __i];
-        if (_Traits::eq(__c, __zero))
-            (*this)[__i] = false;
-        else
-            (*this)[__i] = true;
-    }
-    _VSTD::fill(base::__make_iter(__i), base::__make_iter(_Size), false);
-}
-
-template <size_t _Size>
-inline
-bitset<_Size>&
-bitset<_Size>::operator&=(const bitset& __rhs) _NOEXCEPT
-{
-    base::operator&=(__rhs);
-    return *this;
-}
-
-template <size_t _Size>
-inline
-bitset<_Size>&
-bitset<_Size>::operator|=(const bitset& __rhs) _NOEXCEPT
-{
-    base::operator|=(__rhs);
-    return *this;
-}
-
-template <size_t _Size>
-inline
-bitset<_Size>&
-bitset<_Size>::operator^=(const bitset& __rhs) _NOEXCEPT
-{
-    base::operator^=(__rhs);
-    return *this;
-}
-
-template <size_t _Size>
-bitset<_Size>&
-bitset<_Size>::operator<<=(size_t __pos) _NOEXCEPT
-{
-    __pos = _VSTD::min(__pos, _Size);
-    _VSTD::copy_backward(base::__make_iter(0), base::__make_iter(_Size - __pos), base::__make_iter(_Size));
-    _VSTD::fill_n(base::__make_iter(0), __pos, false);
-    return *this;
-}
-
-template <size_t _Size>
-bitset<_Size>&
-bitset<_Size>::operator>>=(size_t __pos) _NOEXCEPT
-{
-    __pos = _VSTD::min(__pos, _Size);
-    _VSTD::copy(base::__make_iter(__pos), base::__make_iter(_Size), base::__make_iter(0));
-    _VSTD::fill_n(base::__make_iter(_Size - __pos), __pos, false);
-    return *this;
-}
-
-template <size_t _Size>
-inline
-bitset<_Size>&
-bitset<_Size>::set() _NOEXCEPT
-{
-    _VSTD::fill_n(base::__make_iter(0), _Size, true);
-    return *this;
-}
-
-template <size_t _Size>
-bitset<_Size>&
-bitset<_Size>::set(size_t __pos, bool __val)
-{
-    if (__pos >= _Size)
-        __throw_out_of_range("bitset set argument out of range");
-
-    (*this)[__pos] = __val;
-    return *this;
-}
-
-template <size_t _Size>
-inline
-bitset<_Size>&
-bitset<_Size>::reset() _NOEXCEPT
-{
-    _VSTD::fill_n(base::__make_iter(0), _Size, false);
-    return *this;
-}
-
-template <size_t _Size>
-bitset<_Size>&
-bitset<_Size>::reset(size_t __pos)
-{
-    if (__pos >= _Size)
-        __throw_out_of_range("bitset reset argument out of range");
-
-    (*this)[__pos] = false;
-    return *this;
-}
-
-template <size_t _Size>
-inline
-bitset<_Size>
-bitset<_Size>::operator~() const _NOEXCEPT
-{
-    bitset __x(*this);
-    __x.flip();
-    return __x;
-}
-
-template <size_t _Size>
-inline
-bitset<_Size>&
-bitset<_Size>::flip() _NOEXCEPT
-{
-    base::flip();
-    return *this;
-}
-
-template <size_t _Size>
-bitset<_Size>&
-bitset<_Size>::flip(size_t __pos)
-{
-    if (__pos >= _Size)
-        __throw_out_of_range("bitset flip argument out of range");
-
-    reference r = base::__make_ref(__pos);
-    r = ~r;
-    return *this;
-}
-
-template <size_t _Size>
-inline
-unsigned long
-bitset<_Size>::to_ulong() const
-{
-    return base::to_ulong();
-}
-
-template <size_t _Size>
-inline
-unsigned long long
-bitset<_Size>::to_ullong() const
-{
-    return base::to_ullong();
-}
-
-template <size_t _Size>
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-bitset<_Size>::to_string(_CharT __zero, _CharT __one) const
-{
-    basic_string<_CharT, _Traits, _Allocator> __r(_Size, __zero);
-    for (size_t __i = 0; __i < _Size; ++__i)
-    {
-        if ((*this)[__i])
-            __r[_Size - 1 - __i] = __one;
-    }
-    return __r;
-}
-
-template <size_t _Size>
-template <class _CharT, class _Traits>
-inline
-basic_string<_CharT, _Traits, allocator<_CharT> >
-bitset<_Size>::to_string(_CharT __zero, _CharT __one) const
-{
-    return to_string<_CharT, _Traits, allocator<_CharT> >(__zero, __one);
-}
-
-template <size_t _Size>
-template <class _CharT>
-inline
-basic_string<_CharT, char_traits<_CharT>, allocator<_CharT> >
-bitset<_Size>::to_string(_CharT __zero, _CharT __one) const
-{
-    return to_string<_CharT, char_traits<_CharT>, allocator<_CharT> >(__zero, __one);
-}
-
-template <size_t _Size>
-inline
-basic_string<char, char_traits<char>, allocator<char> >
-bitset<_Size>::to_string(char __zero, char __one) const
-{
-    return to_string<char, char_traits<char>, allocator<char> >(__zero, __one);
-}
-
-template <size_t _Size>
-inline
-size_t
-bitset<_Size>::count() const _NOEXCEPT
-{
-    return static_cast<size_t>(__count_bool_true(base::__make_iter(0), _Size));
-}
-
-template <size_t _Size>
-inline
-bool
-bitset<_Size>::operator==(const bitset& __rhs) const _NOEXCEPT
-{
-    return _VSTD::equal(base::__make_iter(0), base::__make_iter(_Size), __rhs.__make_iter(0));
-}
-
-template <size_t _Size>
-inline
-bool
-bitset<_Size>::operator!=(const bitset& __rhs) const _NOEXCEPT
-{
-    return !(*this == __rhs);
-}
-
-template <size_t _Size>
-bool
-bitset<_Size>::test(size_t __pos) const
-{
-    if (__pos >= _Size)
-        __throw_out_of_range("bitset test argument out of range");
-
-    return (*this)[__pos];
-}
-
-template <size_t _Size>
-inline
-bool
-bitset<_Size>::all() const _NOEXCEPT
-{
-    return base::all();
-}
-
-template <size_t _Size>
-inline
-bool
-bitset<_Size>::any() const _NOEXCEPT
-{
-    return base::any();
-}
-
-template <size_t _Size>
-inline
-bitset<_Size>
-bitset<_Size>::operator<<(size_t __pos) const _NOEXCEPT
-{
-    bitset __r = *this;
-    __r <<= __pos;
-    return __r;
-}
-
-template <size_t _Size>
-inline
-bitset<_Size>
-bitset<_Size>::operator>>(size_t __pos) const _NOEXCEPT
-{
-    bitset __r = *this;
-    __r >>= __pos;
-    return __r;
-}
-
-template <size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-bitset<_Size>
-operator&(const bitset<_Size>& __x, const bitset<_Size>& __y) _NOEXCEPT
-{
-    bitset<_Size> __r = __x;
-    __r &= __y;
-    return __r;
-}
-
-template <size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-bitset<_Size>
-operator|(const bitset<_Size>& __x, const bitset<_Size>& __y) _NOEXCEPT
-{
-    bitset<_Size> __r = __x;
-    __r |= __y;
-    return __r;
-}
-
-template <size_t _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-bitset<_Size>
-operator^(const bitset<_Size>& __x, const bitset<_Size>& __y) _NOEXCEPT
-{
-    bitset<_Size> __r = __x;
-    __r ^= __y;
-    return __r;
-}
-
-template <size_t _Size>
-struct _LIBCPP_TEMPLATE_VIS hash<bitset<_Size> >
-    : public unary_function<bitset<_Size>, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const bitset<_Size>& __bs) const _NOEXCEPT
-        {return __bs.__hash_code();}
-};
-
-template <class _CharT, class _Traits, size_t _Size>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, bitset<_Size>& __x);
-
-template <class _CharT, class _Traits, size_t _Size>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const bitset<_Size>& __x);
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_BITSET
diff --git a/lib/libcxx/include/cassert b/lib/libcxx/include/cassert
deleted file mode 100644
index 3775990640a..00000000000
--- a/lib/libcxx/include/cassert
+++ /dev/null
@@ -1,25 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- cassert -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-/*
-    cassert synopsis
-
-Macros:
-
-    assert
-
-*/
-
-#include <__config>
-#include <assert.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
diff --git a/lib/libcxx/include/ccomplex b/lib/libcxx/include/ccomplex
deleted file mode 100644
index 6ed116445e6..00000000000
--- a/lib/libcxx/include/ccomplex
+++ /dev/null
@@ -1,29 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- ccomplex ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CCOMPLEX
-#define _LIBCPP_CCOMPLEX
-
-/*
-    ccomplex synopsis
-
-#include <complex>
-
-*/
-
-#include <complex>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-// hh 080623 Created
-
-#endif  // _LIBCPP_CCOMPLEX
diff --git a/lib/libcxx/include/cctype b/lib/libcxx/include/cctype
deleted file mode 100644
index 7fc81344696..00000000000
--- a/lib/libcxx/include/cctype
+++ /dev/null
@@ -1,121 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- cctype ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CCTYPE
-#define _LIBCPP_CCTYPE
-
-/*
-    cctype synopsis
-
-namespace std
-{
-
-int isalnum(int c);
-int isalpha(int c);
-int isblank(int c);  // C99
-int iscntrl(int c);
-int isdigit(int c);
-int isgraph(int c);
-int islower(int c);
-int isprint(int c);
-int ispunct(int c);
-int isspace(int c);
-int isupper(int c);
-int isxdigit(int c);
-int tolower(int c);
-int toupper(int c);
-
-}  // std
-*/
-
-#include <__config>
-#include <ctype.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#ifdef isalnum
-#undef isalnum
-#endif
-
-#ifdef isalpha
-#undef isalpha
-#endif
-
-#ifdef isblank
-#undef isblank
-#endif
-
-#ifdef iscntrl
-#undef iscntrl
-#endif
-
-#ifdef isdigit
-#undef isdigit
-#endif
-
-#ifdef isgraph
-#undef isgraph
-#endif
-
-#ifdef islower
-#undef islower
-#endif
-
-#ifdef isprint
-#undef isprint
-#endif
-
-#ifdef ispunct
-#undef ispunct
-#endif
-
-#ifdef isspace
-#undef isspace
-#endif
-
-#ifdef isupper
-#undef isupper
-#endif
-
-#ifdef isxdigit
-#undef isxdigit
-#endif
-
-#ifdef tolower
-#undef tolower
-#endif
-
-#ifdef toupper
-#undef toupper
-#endif
-
-
-using ::isalnum;
-using ::isalpha;
-using ::isblank;
-using ::iscntrl;
-using ::isdigit;
-using ::isgraph;
-using ::islower;
-using ::isprint;
-using ::ispunct;
-using ::isspace;
-using ::isupper;
-using ::isxdigit;
-using ::tolower;
-using ::toupper;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CCTYPE
diff --git a/lib/libcxx/include/cerrno b/lib/libcxx/include/cerrno
deleted file mode 100644
index bab13b8aa86..00000000000
--- a/lib/libcxx/include/cerrno
+++ /dev/null
@@ -1,33 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- cerrno ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CERRNO
-#define _LIBCPP_CERRNO
-
-/*
-    cerrno synopsis
-
-Macros:
-
-    EDOM
-    EILSEQ  // C99
-    ERANGE
-    errno
-
-*/
-
-#include <__config>
-#include <errno.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#endif  // _LIBCPP_CERRNO
diff --git a/lib/libcxx/include/cfenv b/lib/libcxx/include/cfenv
deleted file mode 100644
index 4fc630419bd..00000000000
--- a/lib/libcxx/include/cfenv
+++ /dev/null
@@ -1,82 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- cfenv -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CFENV
-#define _LIBCPP_CFENV
-
-/*
-    cfenv synopsis
-
-This entire header is C99 / C++0X
-
-Macros:
-
-    FE_DIVBYZERO
-    FE_INEXACT
-    FE_INVALID
-    FE_OVERFLOW
-    FE_UNDERFLOW
-    FE_ALL_EXCEPT
-    FE_DOWNWARD
-    FE_TONEAREST
-    FE_TOWARDZERO
-    FE_UPWARD
-    FE_DFL_ENV
-
-namespace std
-{
-
-Types:
-
-    fenv_t
-    fexcept_t
-
-int feclearexcept(int excepts);
-int fegetexceptflag(fexcept_t* flagp, int excepts);
-int feraiseexcept(int excepts);
-int fesetexceptflag(const fexcept_t* flagp, int excepts);
-int fetestexcept(int excepts);
-int fegetround();
-int fesetround(int round);
-int fegetenv(fenv_t* envp);
-int feholdexcept(fenv_t* envp);
-int fesetenv(const fenv_t* envp);
-int feupdateenv(const fenv_t* envp);
-
-}  // std
-*/
-
-#include <__config>
-#include <fenv.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::fenv_t;
-using ::fexcept_t;
-
-using ::feclearexcept;
-using ::fegetexceptflag;
-using ::feraiseexcept;
-using ::fesetexceptflag;
-using ::fetestexcept;
-using ::fegetround;
-using ::fesetround;
-using ::fegetenv;
-using ::feholdexcept;
-using ::fesetenv;
-using ::feupdateenv;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CFENV
diff --git a/lib/libcxx/include/cfloat b/lib/libcxx/include/cfloat
deleted file mode 100644
index 0abe84bf175..00000000000
--- a/lib/libcxx/include/cfloat
+++ /dev/null
@@ -1,80 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cfloat -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CFLOAT
-#define _LIBCPP_CFLOAT
-
-/*
-    cfloat synopsis
-
-Macros:
-
-    FLT_ROUNDS
-    FLT_EVAL_METHOD     // C99
-    FLT_RADIX
-
-    FLT_HAS_SUBNORM     // C11
-    DBL_HAS_SUBNORM     // C11
-    LDBL_HAS_SUBNORM    // C11
-
-    FLT_MANT_DIG
-    DBL_MANT_DIG
-    LDBL_MANT_DIG
-
-    DECIMAL_DIG         // C99
-    FLT_DECIMAL_DIG     // C11
-    DBL_DECIMAL_DIG     // C11
-    LDBL_DECIMAL_DIG    // C11
-
-    FLT_DIG
-    DBL_DIG
-    LDBL_DIG
-
-    FLT_MIN_EXP
-    DBL_MIN_EXP
-    LDBL_MIN_EXP
-
-    FLT_MIN_10_EXP
-    DBL_MIN_10_EXP
-    LDBL_MIN_10_EXP
-
-    FLT_MAX_EXP
-    DBL_MAX_EXP
-    LDBL_MAX_EXP
-
-    FLT_MAX_10_EXP
-    DBL_MAX_10_EXP
-    LDBL_MAX_10_EXP
-
-    FLT_MAX
-    DBL_MAX
-    LDBL_MAX
-
-    FLT_EPSILON
-    DBL_EPSILON
-    LDBL_EPSILON
-
-    FLT_MIN
-    DBL_MIN
-    LDBL_MIN
-
-    FLT_TRUE_MIN        // C11
-    DBL_TRUE_MIN        // C11
-    LDBL_TRUE_MIN       // C11
-*/
-
-#include <__config>
-#include <float.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#endif  // _LIBCPP_CFLOAT
diff --git a/lib/libcxx/include/charconv b/lib/libcxx/include/charconv
deleted file mode 100644
index 064f2e11c3f..00000000000
--- a/lib/libcxx/include/charconv
+++ /dev/null
@@ -1,617 +0,0 @@
-// -*- C++ -*-
-//===------------------------------ charconv ------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CHARCONV
-#define _LIBCPP_CHARCONV
-
-/*
-    charconv synopsis
-
-namespace std {
-
-  // floating-point format for primitive numerical conversion
-  enum class chars_format {
-    scientific = unspecified,
-    fixed = unspecified,
-    hex = unspecified,
-    general = fixed | scientific
-  };
-
-  // 23.20.2, primitive numerical output conversion
-  struct to_chars_result {
-    char* ptr;
-    errc ec;
-  };
-
-  to_chars_result to_chars(char* first, char* last, see below value,
-                           int base = 10);
-
-  to_chars_result to_chars(char* first, char* last, float value);
-  to_chars_result to_chars(char* first, char* last, double value);
-  to_chars_result to_chars(char* first, char* last, long double value);
-
-  to_chars_result to_chars(char* first, char* last, float value,
-                           chars_format fmt);
-  to_chars_result to_chars(char* first, char* last, double value,
-                           chars_format fmt);
-  to_chars_result to_chars(char* first, char* last, long double value,
-                           chars_format fmt);
-
-  to_chars_result to_chars(char* first, char* last, float value,
-                           chars_format fmt, int precision);
-  to_chars_result to_chars(char* first, char* last, double value,
-                           chars_format fmt, int precision);
-  to_chars_result to_chars(char* first, char* last, long double value,
-                           chars_format fmt, int precision);
-
-  // 23.20.3, primitive numerical input conversion
-  struct from_chars_result {
-    const char* ptr;
-    errc ec;
-  };
-
-  from_chars_result from_chars(const char* first, const char* last,
-                               see below& value, int base = 10);
-
-  from_chars_result from_chars(const char* first, const char* last,
-                               float& value,
-                               chars_format fmt = chars_format::general);
-  from_chars_result from_chars(const char* first, const char* last,
-                               double& value,
-                               chars_format fmt = chars_format::general);
-  from_chars_result from_chars(const char* first, const char* last,
-                               long double& value,
-                               chars_format fmt = chars_format::general);
-
-} // namespace std
-
-*/
-
-#include <__errc>
-#include <type_traits>
-#include <limits>
-#include <stdint.h>
-#include <string.h>
-#include <math.h>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-namespace __itoa {
-_LIBCPP_FUNC_VIS char* __u64toa(uint64_t __value, char* __buffer);
-_LIBCPP_FUNC_VIS char* __u32toa(uint32_t __value, char* __buffer);
-}
-
-#if _LIBCPP_STD_VER > 11
-
-enum class _LIBCPP_ENUM_VIS chars_format
-{
-    scientific = 0x1,
-    fixed = 0x2,
-    hex = 0x4,
-    general = fixed | scientific
-};
-
-struct _LIBCPP_TYPE_VIS to_chars_result
-{
-    char* ptr;
-    errc ec;
-};
-
-struct _LIBCPP_TYPE_VIS from_chars_result
-{
-    const char* ptr;
-    errc ec;
-};
-
-void to_chars(char*, char*, bool, int = 10) = delete;
-void from_chars(const char*, const char*, bool, int = 10) = delete;
-
-namespace __itoa
-{
-
-static constexpr uint64_t __pow10_64[] = {
-    UINT64_C(0),
-    UINT64_C(10),
-    UINT64_C(100),
-    UINT64_C(1000),
-    UINT64_C(10000),
-    UINT64_C(100000),
-    UINT64_C(1000000),
-    UINT64_C(10000000),
-    UINT64_C(100000000),
-    UINT64_C(1000000000),
-    UINT64_C(10000000000),
-    UINT64_C(100000000000),
-    UINT64_C(1000000000000),
-    UINT64_C(10000000000000),
-    UINT64_C(100000000000000),
-    UINT64_C(1000000000000000),
-    UINT64_C(10000000000000000),
-    UINT64_C(100000000000000000),
-    UINT64_C(1000000000000000000),
-    UINT64_C(10000000000000000000),
-};
-
-static constexpr uint32_t __pow10_32[] = {
-    UINT32_C(0),          UINT32_C(10),       UINT32_C(100),
-    UINT32_C(1000),       UINT32_C(10000),    UINT32_C(100000),
-    UINT32_C(1000000),    UINT32_C(10000000), UINT32_C(100000000),
-    UINT32_C(1000000000),
-};
-
-template <typename _Tp, typename = void>
-struct _LIBCPP_HIDDEN __traits_base
-{
-    using type = uint64_t;
-
-#if !defined(_LIBCPP_COMPILER_MSVC)
-    static _LIBCPP_INLINE_VISIBILITY int __width(_Tp __v)
-    {
-        auto __t = (64 - __builtin_clzll(__v | 1)) * 1233 >> 12;
-        return __t - (__v < __pow10_64[__t]) + 1;
-    }
-#endif
-
-    static _LIBCPP_INLINE_VISIBILITY char* __convert(_Tp __v, char* __p)
-    {
-        return __u64toa(__v, __p);
-    }
-
-    static _LIBCPP_INLINE_VISIBILITY auto& __pow() { return __pow10_64; }
-};
-
-template <typename _Tp>
-struct _LIBCPP_HIDDEN
-    __traits_base<_Tp, decltype(void(uint32_t{declval<_Tp>()}))>
-{
-    using type = uint32_t;
-
-#if !defined(_LIBCPP_COMPILER_MSVC)
-    static _LIBCPP_INLINE_VISIBILITY int __width(_Tp __v)
-    {
-        auto __t = (32 - __builtin_clz(__v | 1)) * 1233 >> 12;
-        return __t - (__v < __pow10_32[__t]) + 1;
-    }
-#endif
-
-    static _LIBCPP_INLINE_VISIBILITY char* __convert(_Tp __v, char* __p)
-    {
-        return __u32toa(__v, __p);
-    }
-
-    static _LIBCPP_INLINE_VISIBILITY auto& __pow() { return __pow10_32; }
-};
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY bool
-__mul_overflowed(unsigned char __a, _Tp __b, unsigned char& __r)
-{
-    auto __c = __a * __b;
-    __r = __c;
-    return __c > (numeric_limits<unsigned char>::max)();
-}
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY bool
-__mul_overflowed(unsigned short __a, _Tp __b, unsigned short& __r)
-{
-    auto __c = __a * __b;
-    __r = __c;
-    return __c > (numeric_limits<unsigned short>::max)();
-}
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY bool
-__mul_overflowed(_Tp __a, _Tp __b, _Tp& __r)
-{
-    static_assert(is_unsigned<_Tp>::value, "");
-#if !defined(_LIBCPP_COMPILER_MSVC)
-    return __builtin_mul_overflow(__a, __b, &__r);
-#else
-    bool __did = __b && ((numeric_limits<_Tp>::max)() / __b) < __a;
-    __r = __a * __b;
-    return __did;
-#endif
-}
-
-template <typename _Tp, typename _Up>
-inline _LIBCPP_INLINE_VISIBILITY bool
-__mul_overflowed(_Tp __a, _Up __b, _Tp& __r)
-{
-    return __mul_overflowed(__a, static_cast<_Tp>(__b), __r);
-}
-
-template <typename _Tp>
-struct _LIBCPP_HIDDEN __traits : __traits_base<_Tp>
-{
-    static constexpr int digits = numeric_limits<_Tp>::digits10 + 1;
-    using __traits_base<_Tp>::__pow;
-    using typename __traits_base<_Tp>::type;
-
-    // precondition: at least one non-zero character available
-    static _LIBCPP_INLINE_VISIBILITY char const*
-    __read(char const* __p, char const* __ep, type& __a, type& __b)
-    {
-        type __cprod[digits];
-        int __j = digits - 1;
-        int __i = digits;
-        do
-        {
-            if (!('0' <= *__p && *__p <= '9'))
-                break;
-            __cprod[--__i] = *__p++ - '0';
-        } while (__p != __ep && __i != 0);
-
-        __a = __inner_product(__cprod + __i + 1, __cprod + __j, __pow() + 1,
-                              __cprod[__i]);
-        if (__mul_overflowed(__cprod[__j], __pow()[__j - __i], __b))
-            --__p;
-        return __p;
-    }
-
-    template <typename _It1, typename _It2, class _Up>
-    static _LIBCPP_INLINE_VISIBILITY _Up
-    __inner_product(_It1 __first1, _It1 __last1, _It2 __first2, _Up __init)
-    {
-        for (; __first1 < __last1; ++__first1, ++__first2)
-            __init = __init + *__first1 * *__first2;
-        return __init;
-    }
-};
-
-}  // namespace __itoa
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _Tp
-__complement(_Tp __x)
-{
-    static_assert(is_unsigned<_Tp>::value, "cast to unsigned first");
-    return _Tp(~__x + 1);
-}
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY auto
-__to_unsigned(_Tp __x)
-{
-    return static_cast<make_unsigned_t<_Tp>>(__x);
-}
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY to_chars_result
-__to_chars_itoa(char* __first, char* __last, _Tp __value, true_type)
-{
-    auto __x = __to_unsigned(__value);
-    if (__value < 0 && __first != __last)
-    {
-        *__first++ = '-';
-        __x = __complement(__x);
-    }
-
-    return __to_chars_itoa(__first, __last, __x, false_type());
-}
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY to_chars_result
-__to_chars_itoa(char* __first, char* __last, _Tp __value, false_type)
-{
-    using __tx = __itoa::__traits<_Tp>;
-    auto __diff = __last - __first;
-
-#if !defined(_LIBCPP_COMPILER_MSVC)
-    if (__tx::digits <= __diff || __tx::__width(__value) <= __diff)
-        return {__tx::__convert(__value, __first), {}};
-    else
-        return {__last, errc::value_too_large};
-#else
-    if (__tx::digits <= __diff)
-        return {__tx::__convert(__value, __first), {}};
-    else
-    {
-        char __buf[__tx::digits];
-        auto __p = __tx::__convert(__value, __buf);
-        auto __len = __p - __buf;
-        if (__len <= __diff)
-        {
-            memcpy(__first, __buf, __len);
-            return {__first + __len, {}};
-        }
-        else
-            return {__last, errc::value_too_large};
-    }
-#endif
-}
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY to_chars_result
-__to_chars_integral(char* __first, char* __last, _Tp __value, int __base,
-                    true_type)
-{
-    auto __x = __to_unsigned(__value);
-    if (__value < 0 && __first != __last)
-    {
-        *__first++ = '-';
-        __x = __complement(__x);
-    }
-
-    return __to_chars_integral(__first, __last, __x, __base, false_type());
-}
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY to_chars_result
-__to_chars_integral(char* __first, char* __last, _Tp __value, int __base,
-                    false_type)
-{
-    if (__base == 10)
-        return __to_chars_itoa(__first, __last, __value, false_type());
-
-    auto __p = __last;
-    while (__p != __first)
-    {
-        auto __c = __value % __base;
-        __value /= __base;
-        *--__p = "0123456789abcdefghijklmnopqrstuvwxyz"[__c];
-        if (__value == 0)
-            break;
-    }
-
-    auto __len = __last - __p;
-    if (__value != 0 || !__len)
-        return {__last, errc::value_too_large};
-    else
-    {
-        memmove(__first, __p, __len);
-        return {__first + __len, {}};
-    }
-}
-
-template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
-inline _LIBCPP_INLINE_VISIBILITY to_chars_result
-to_chars(char* __first, char* __last, _Tp __value)
-{
-    return __to_chars_itoa(__first, __last, __value, is_signed<_Tp>());
-}
-
-template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
-inline _LIBCPP_INLINE_VISIBILITY to_chars_result
-to_chars(char* __first, char* __last, _Tp __value, int __base)
-{
-    _LIBCPP_ASSERT(2 <= __base && __base <= 36, "base not in [2, 36]");
-    return __to_chars_integral(__first, __last, __value, __base,
-                               is_signed<_Tp>());
-}
-
-template <typename _It, typename _Tp, typename _Fn, typename... _Ts>
-inline _LIBCPP_INLINE_VISIBILITY from_chars_result
-__sign_combinator(_It __first, _It __last, _Tp& __value, _Fn __f, _Ts... __args)
-{
-    using __tl = numeric_limits<_Tp>;
-    decltype(__to_unsigned(__value)) __x;
-
-    bool __neg = (__first != __last && *__first == '-');
-    auto __r = __f(__neg ? __first + 1 : __first, __last, __x, __args...);
-    switch (__r.ec)
-    {
-    case errc::invalid_argument:
-        return {__first, __r.ec};
-    case errc::result_out_of_range:
-        return __r;
-    default:
-        break;
-    }
-
-    if (__neg)
-    {
-        if (__x <= __complement(__to_unsigned(__tl::min())))
-        {
-            __x = __complement(__x);
-            memcpy(&__value, &__x, sizeof(__x));
-            return __r;
-        }
-    }
-    else
-    {
-        if (__x <= (__tl::max)())
-        {
-            __value = __x;
-            return __r;
-        }
-    }
-
-    return {__r.ptr, errc::result_out_of_range};
-}
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY bool
-__in_pattern(_Tp __c)
-{
-    return '0' <= __c && __c <= '9';
-}
-
-struct _LIBCPP_HIDDEN __in_pattern_result
-{
-    bool __ok;
-    int __val;
-
-    explicit _LIBCPP_INLINE_VISIBILITY operator bool() const { return __ok; }
-};
-
-template <typename _Tp>
-inline _LIBCPP_INLINE_VISIBILITY __in_pattern_result
-__in_pattern(_Tp __c, int __base)
-{
-    if (__base <= 10)
-        return {'0' <= __c && __c < '0' + __base, __c - '0'};
-    else if (__in_pattern(__c))
-        return {true, __c - '0'};
-    else if ('a' <= __c && __c < 'a' + __base - 10)
-        return {true, __c - 'a' + 10};
-    else
-        return {'A' <= __c && __c < 'A' + __base - 10, __c - 'A' + 10};
-}
-
-template <typename _It, typename _Tp, typename _Fn, typename... _Ts>
-inline _LIBCPP_INLINE_VISIBILITY from_chars_result
-__subject_seq_combinator(_It __first, _It __last, _Tp& __value, _Fn __f,
-                         _Ts... __args)
-{
-    auto __find_non_zero = [](_It __first, _It __last) {
-        for (; __first != __last; ++__first)
-            if (*__first != '0')
-                break;
-        return __first;
-    };
-
-    auto __p = __find_non_zero(__first, __last);
-    if (__p == __last || !__in_pattern(*__p, __args...))
-    {
-        if (__p == __first)
-            return {__first, errc::invalid_argument};
-        else
-        {
-            __value = 0;
-            return {__p, {}};
-        }
-    }
-
-    auto __r = __f(__p, __last, __value, __args...);
-    if (__r.ec == errc::result_out_of_range)
-    {
-        for (; __r.ptr != __last; ++__r.ptr)
-        {
-            if (!__in_pattern(*__r.ptr, __args...))
-                break;
-        }
-    }
-
-    return __r;
-}
-
-template <typename _Tp, enable_if_t<is_unsigned<_Tp>::value, int> = 0>
-inline _LIBCPP_INLINE_VISIBILITY from_chars_result
-__from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
-{
-    using __tx = __itoa::__traits<_Tp>;
-    using __output_type = typename __tx::type;
-
-    return __subject_seq_combinator(
-        __first, __last, __value,
-        [](const char* __first, const char* __last,
-           _Tp& __value) -> from_chars_result {
-            __output_type __a, __b;
-            auto __p = __tx::__read(__first, __last, __a, __b);
-            if (__p == __last || !__in_pattern(*__p))
-            {
-                __output_type __m = (numeric_limits<_Tp>::max)();
-                if (__m >= __a && __m - __a >= __b)
-                {
-                    __value = __a + __b;
-                    return {__p, {}};
-                }
-            }
-            return {__p, errc::result_out_of_range};
-        });
-}
-
-template <typename _Tp, enable_if_t<is_signed<_Tp>::value, int> = 0>
-inline _LIBCPP_INLINE_VISIBILITY from_chars_result
-__from_chars_atoi(const char* __first, const char* __last, _Tp& __value)
-{
-    using __t = decltype(__to_unsigned(__value));
-    return __sign_combinator(__first, __last, __value, __from_chars_atoi<__t>);
-}
-
-template <typename _Tp, enable_if_t<is_unsigned<_Tp>::value, int> = 0>
-inline _LIBCPP_INLINE_VISIBILITY from_chars_result
-__from_chars_integral(const char* __first, const char* __last, _Tp& __value,
-                      int __base)
-{
-    if (__base == 10)
-        return __from_chars_atoi(__first, __last, __value);
-
-    return __subject_seq_combinator(
-        __first, __last, __value,
-        [](const char* __p, const char* __last, _Tp& __value,
-           int __base) -> from_chars_result {
-            using __tl = numeric_limits<_Tp>;
-            auto __digits = __tl::digits / log2f(float(__base));
-            _Tp __a = __in_pattern(*__p++, __base).__val, __b = 0;
-
-            for (int __i = 1; __p != __last; ++__i, ++__p)
-            {
-                if (auto __c = __in_pattern(*__p, __base))
-                {
-                    if (__i < __digits - 1)
-                        __a = __a * __base + __c.__val;
-                    else
-                    {
-                        if (!__itoa::__mul_overflowed(__a, __base, __a))
-                            ++__p;
-                        __b = __c.__val;
-                        break;
-                    }
-                }
-                else
-                    break;
-            }
-
-            if (__p == __last || !__in_pattern(*__p, __base))
-            {
-                if ((__tl::max)() - __a >= __b)
-                {
-                    __value = __a + __b;
-                    return {__p, {}};
-                }
-            }
-            return {__p, errc::result_out_of_range};
-        },
-        __base);
-}
-
-template <typename _Tp, enable_if_t<is_signed<_Tp>::value, int> = 0>
-inline _LIBCPP_INLINE_VISIBILITY from_chars_result
-__from_chars_integral(const char* __first, const char* __last, _Tp& __value,
-                      int __base)
-{
-    using __t = decltype(__to_unsigned(__value));
-    return __sign_combinator(__first, __last, __value,
-                             __from_chars_integral<__t>, __base);
-}
-
-template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
-inline _LIBCPP_INLINE_VISIBILITY from_chars_result
-from_chars(const char* __first, const char* __last, _Tp& __value)
-{
-    return __from_chars_atoi(__first, __last, __value);
-}
-
-template <typename _Tp, enable_if_t<is_integral<_Tp>::value, int> = 0>
-inline _LIBCPP_INLINE_VISIBILITY from_chars_result
-from_chars(const char* __first, const char* __last, _Tp& __value, int __base)
-{
-    _LIBCPP_ASSERT(2 <= __base && __base <= 36, "base not in [2, 36]");
-    return __from_chars_integral(__first, __last, __value, __base);
-}
-
-#endif  // _LIBCPP_STD_VER > 11
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_CHARCONV
diff --git a/lib/libcxx/include/chrono b/lib/libcxx/include/chrono
deleted file mode 100644
index 96759f9860e..00000000000
--- a/lib/libcxx/include/chrono
+++ /dev/null
@@ -1,2865 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- chrono ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CHRONO
-#define _LIBCPP_CHRONO
-
-/*
-    chrono synopsis
-
-namespace std
-{
-namespace chrono
-{
-
-template <class ToDuration, class Rep, class Period>
-constexpr
-ToDuration
-duration_cast(const duration<Rep, Period>& fd);
-
-template <class Rep> struct treat_as_floating_point : is_floating_point<Rep> {};
-
-template <class Rep> inline constexpr bool treat_as_floating_point_v
-    = treat_as_floating_point<Rep>::value;                       // C++17
-
-template <class Rep>
-struct duration_values
-{
-public:
-    static constexpr Rep zero(); // noexcept in C++20
-    static constexpr Rep max();  // noexcept in C++20
-    static constexpr Rep min();  // noexcept in C++20
-};
-
-// duration
-
-template <class Rep, class Period = ratio<1>>
-class duration
-{
-    static_assert(!__is_duration<Rep>::value, "A duration representation can not be a duration");
-    static_assert(__is_ratio<Period>::value, "Second template parameter of duration must be a std::ratio");
-    static_assert(Period::num > 0, "duration period must be positive");
-public:
-    typedef Rep rep;
-    typedef typename _Period::type period;
-
-    constexpr duration() = default;
-    template <class Rep2>
-        constexpr explicit duration(const Rep2& r,
-            typename enable_if
-            <
-               is_convertible<Rep2, rep>::value &&
-               (treat_as_floating_point<rep>::value ||
-               !treat_as_floating_point<rep>::value && !treat_as_floating_point<Rep2>::value)
-            >::type* = 0);
-
-    // conversions
-    template <class Rep2, class Period2>
-        constexpr duration(const duration<Rep2, Period2>& d,
-            typename enable_if
-            <
-                treat_as_floating_point<rep>::value ||
-                ratio_divide<Period2, period>::type::den == 1
-            >::type* = 0);
-
-    // observer
-
-    constexpr rep count() const;
-
-    // arithmetic
-
-    constexpr common_type<duration>::type  operator+() const;
-    constexpr common_type<duration>::type  operator-() const;
-    constexpr duration& operator++();    // constexpr in C++17
-    constexpr duration  operator++(int); // constexpr in C++17
-    constexpr duration& operator--();    // constexpr in C++17
-    constexpr duration  operator--(int); // constexpr in C++17
-
-    constexpr duration& operator+=(const duration& d);  // constexpr in C++17
-    constexpr duration& operator-=(const duration& d);  // constexpr in C++17
-
-    duration& operator*=(const rep& rhs);       // constexpr in C++17
-    duration& operator/=(const rep& rhs);       // constexpr in C++17
-    duration& operator%=(const rep& rhs);       // constexpr in C++17
-    duration& operator%=(const duration& rhs);  // constexpr in C++17
-
-    // special values
-
-    static constexpr duration zero(); // noexcept in C++20
-    static constexpr duration min();  // noexcept in C++20
-    static constexpr duration max();  // noexcept in C++20
-};
-
-typedef duration<long long,         nano> nanoseconds;
-typedef duration<long long,        micro> microseconds;
-typedef duration<long long,        milli> milliseconds;
-typedef duration<long long              > seconds;
-typedef duration<     long, ratio<  60> > minutes;
-typedef duration<     long, ratio<3600> > hours;
-
-template <class Clock, class Duration = typename Clock::duration>
-class time_point
-{
-public:
-    typedef Clock                     clock;
-    typedef Duration                  duration;
-    typedef typename duration::rep    rep;
-    typedef typename duration::period period;
-private:
-    duration d_;  // exposition only
-
-public:
-    time_point();  // has value "epoch" // constexpr in C++14
-    explicit time_point(const duration& d);  // same as time_point() + d // constexpr in C++14
-
-    // conversions
-    template <class Duration2>
-       time_point(const time_point<clock, Duration2>& t); // constexpr in C++14
-
-    // observer
-
-    duration time_since_epoch() const; // constexpr in C++14
-
-    // arithmetic
-
-    time_point& operator+=(const duration& d); // constexpr in C++17
-    time_point& operator-=(const duration& d); // constexpr in C++17
-
-    // special values
-
-    static constexpr time_point min();  // noexcept in C++20
-    static constexpr time_point max();  // noexcept in C++20
-};
-
-} // chrono
-
-// common_type traits
-template <class Rep1, class Period1, class Rep2, class Period2>
-  struct common_type<chrono::duration<Rep1, Period1>, chrono::duration<Rep2, Period2>>;
-
-template <class Clock, class Duration1, class Duration2>
-  struct common_type<chrono::time_point<Clock, Duration1>, chrono::time_point<Clock, Duration2>>;
-
-namespace chrono {
-
-
-template<class T> struct is_clock;  // C++20
-template<class T> inline constexpr bool is_clock_v = is_clock<T>::value;   // C++20
-
-
-// duration arithmetic
-template <class Rep1, class Period1, class Rep2, class Period2>
-  constexpr
-  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
-  operator+(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-  constexpr
-  typename common_type<duration<Rep1, Period1>, duration<Rep2, Period2>>::type
-  operator-(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period, class Rep2>
-  constexpr
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator*(const duration<Rep1, Period>& d, const Rep2& s);
-template <class Rep1, class Period, class Rep2>
-  constexpr
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator*(const Rep1& s, const duration<Rep2, Period>& d);
-template <class Rep1, class Period, class Rep2>
-  constexpr
-  duration<typename common_type<Rep1, Rep2>::type, Period>
-  operator/(const duration<Rep1, Period>& d, const Rep2& s);
-template <class Rep1, class Period1, class Rep2, class Period2>
-  constexpr
-  typename common_type<Rep1, Rep2>::type
-  operator/(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-
-// duration comparisons
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr
-   bool operator==(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr
-   bool operator!=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr
-   bool operator< (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr
-   bool operator<=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr
-   bool operator> (const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Rep2, class Period2>
-   constexpr
-   bool operator>=(const duration<Rep1, Period1>& lhs, const duration<Rep2, Period2>& rhs);
-
-// duration_cast
-template <class ToDuration, class Rep, class Period>
-  ToDuration duration_cast(const duration<Rep, Period>& d);
-
-template <class ToDuration, class Rep, class Period>
-    constexpr ToDuration floor(const duration<Rep, Period>& d);    // C++17
-template <class ToDuration, class Rep, class Period>
-    constexpr ToDuration ceil(const duration<Rep, Period>& d);     // C++17
-template <class ToDuration, class Rep, class Period>
-    constexpr ToDuration round(const duration<Rep, Period>& d);    // C++17
-
-// duration I/O is elsewhere
-
-// time_point arithmetic (all constexpr in C++14)
-template <class Clock, class Duration1, class Rep2, class Period2>
-  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
-  operator+(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Rep1, class Period1, class Clock, class Duration2>
-  time_point<Clock, typename common_type<duration<Rep1, Period1>, Duration2>::type>
-  operator+(const duration<Rep1, Period1>& lhs, const time_point<Clock, Duration2>& rhs);
-template <class Clock, class Duration1, class Rep2, class Period2>
-  time_point<Clock, typename common_type<Duration1, duration<Rep2, Period2>>::type>
-  operator-(const time_point<Clock, Duration1>& lhs, const duration<Rep2, Period2>& rhs);
-template <class Clock, class Duration1, class Duration2>
-  typename common_type<Duration1, Duration2>::type
-  operator-(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
-
-// time_point comparisons (all constexpr in C++14)
-template <class Clock, class Duration1, class Duration2>
-   bool operator==(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
-template <class Clock, class Duration1, class Duration2>
-   bool operator!=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
-template <class Clock, class Duration1, class Duration2>
-   bool operator< (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
-template <class Clock, class Duration1, class Duration2>
-   bool operator<=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
-template <class Clock, class Duration1, class Duration2>
-   bool operator> (const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
-template <class Clock, class Duration1, class Duration2>
-   bool operator>=(const time_point<Clock, Duration1>& lhs, const time_point<Clock, Duration2>& rhs);
-
-// time_point_cast (constexpr in C++14)
-
-template <class ToDuration, class Clock, class Duration>
-  time_point<Clock, ToDuration> time_point_cast(const time_point<Clock, Duration>& t);
-
-template <class ToDuration, class Clock, class Duration>
-    constexpr time_point<Clock, ToDuration>
-    floor(const time_point<Clock, Duration>& tp);                  // C++17
-
-template <class ToDuration, class Clock, class Duration>
-    constexpr time_point<Clock, ToDuration>
-    ceil(const time_point<Clock, Duration>& tp);                   // C++17
-
-template <class ToDuration, class Clock, class Duration>
-    constexpr time_point<Clock, ToDuration>
-    round(const time_point<Clock, Duration>& tp);                  // C++17
-
-template <class Rep, class Period>
-    constexpr duration<Rep, Period> abs(duration<Rep, Period> d);  // C++17
-
-// Clocks
-
-class system_clock
-{
-public:
-    typedef microseconds                     duration;
-    typedef duration::rep                    rep;
-    typedef duration::period                 period;
-    typedef chrono::time_point<system_clock> time_point;
-    static const bool is_steady =            false; // constexpr in C++14
-
-    static time_point now() noexcept;
-    static time_t     to_time_t  (const time_point& __t) noexcept;
-    static time_point from_time_t(time_t __t) noexcept;
-};
-
-template <class Duration>
-  using sys_time  = time_point<system_clock, Duration>; // C++20
-using sys_seconds = sys_time<seconds>;                  // C++20
-using sys_days    = sys_time<days>;                     // C++20
-
-class utc_clock;                                        // C++20
-
-template <class Duration>
-  using utc_time  = time_point<utc_clock, Duration>;    // C++20
-using utc_seconds = utc_time<seconds>;                  // C++20
-
-class tai_clock;                                        // C++20
-
-template <class Duration>
-  using tai_time  = time_point<tai_clock, Duration>;    // C++20
-using tai_seconds = tai_time<seconds>;                  // C++20
-
-class file_clock;                                       // C++20
-
-template<class Duration>
-  using file_time = time_point<file_clock, Duration>;   // C++20
-
-class steady_clock
-{
-public:
-    typedef nanoseconds                                   duration;
-    typedef duration::rep                                 rep;
-    typedef duration::period                              period;
-    typedef chrono::time_point<steady_clock, duration>    time_point;
-    static const bool is_steady =                         true; // constexpr in C++14
-
-    static time_point now() noexcept;
-};
-
-typedef steady_clock high_resolution_clock;
-
-// 25.7.8, local time           // C++20
-struct local_t {};
-template<class Duration>
-  using local_time  = time_point<local_t, Duration>;
-using local_seconds = local_time<seconds>;
-using local_days    = local_time<days>;
-
-// 25.7.9, time_point conversions template<class DestClock, class SourceClock>    // C++20
-struct clock_time_conversion;
-
-template<class DestClock, class SourceClock, class Duration>
-  auto clock_cast(const time_point<SourceClock, Duration>& t);
-
-// 25.8.2, class last_spec    // C++20
-struct last_spec;
-
-// 25.8.3, class day          // C++20
-
-class day;
-constexpr bool operator==(const day& x, const day& y) noexcept;
-constexpr bool operator!=(const day& x, const day& y) noexcept;
-constexpr bool operator< (const day& x, const day& y) noexcept;
-constexpr bool operator> (const day& x, const day& y) noexcept;
-constexpr bool operator<=(const day& x, const day& y) noexcept;
-constexpr bool operator>=(const day& x, const day& y) noexcept;
-constexpr day  operator+(const day&  x, const days& y) noexcept;
-constexpr day  operator+(const days& x, const day&  y) noexcept;
-constexpr day  operator-(const day&  x, const days& y) noexcept;
-constexpr days operator-(const day&  x, const day&  y) noexcept;
-
-// 25.8.4, class month    // C++20
-class month;
-constexpr bool operator==(const month& x, const month& y) noexcept;
-constexpr bool operator!=(const month& x, const month& y) noexcept;
-constexpr bool operator< (const month& x, const month& y) noexcept;
-constexpr bool operator> (const month& x, const month& y) noexcept;
-constexpr bool operator<=(const month& x, const month& y) noexcept;
-constexpr bool operator>=(const month& x, const month& y) noexcept;
-constexpr month  operator+(const month&  x, const months& y) noexcept;
-constexpr month  operator+(const months& x,  const month& y) noexcept;
-constexpr month  operator-(const month&  x, const months& y) noexcept;
-constexpr months operator-(const month&  x,  const month& y) noexcept;
-
-// 25.8.5, class year    // C++20
-class year;
-constexpr bool operator==(const year& x, const year& y) noexcept;
-constexpr bool operator!=(const year& x, const year& y) noexcept;
-constexpr bool operator< (const year& x, const year& y) noexcept;
-constexpr bool operator> (const year& x, const year& y) noexcept;
-constexpr bool operator<=(const year& x, const year& y) noexcept;
-constexpr bool operator>=(const year& x, const year& y) noexcept;
-constexpr year  operator+(const year&  x, const years& y) noexcept;
-constexpr year  operator+(const years& x, const year&  y) noexcept;
-constexpr year  operator-(const year&  x, const years& y) noexcept;
-constexpr years operator-(const year&  x, const year&  y) noexcept;
-
-// 25.8.6, class weekday    // C++20
-class weekday;
-
-constexpr bool operator==(const weekday& x, const weekday& y) noexcept;
-constexpr bool operator!=(const weekday& x, const weekday& y) noexcept;
-constexpr weekday operator+(const weekday& x, const days&    y) noexcept;
-constexpr weekday operator+(const days&    x, const weekday& y) noexcept;
-constexpr weekday operator-(const weekday& x, const days&    y) noexcept;
-constexpr days    operator-(const weekday& x, const weekday& y) noexcept;
-
-// 25.8.7, class weekday_indexed    // C++20
-
-class weekday_indexed;
-constexpr bool operator==(const weekday_indexed& x, const weekday_indexed& y) noexcept;
-constexpr bool operator!=(const weekday_indexed& x, const weekday_indexed& y) noexcept;
-
-// 25.8.8, class weekday_last    // C++20
-class weekday_last;
-
-constexpr bool operator==(const weekday_last& x, const weekday_last& y) noexcept;
-constexpr bool operator!=(const weekday_last& x, const weekday_last& y) noexcept;
-
-// 25.8.9, class month_day    // C++20
-class month_day;
-
-constexpr bool operator==(const month_day& x, const month_day& y) noexcept;
-constexpr bool operator!=(const month_day& x, const month_day& y) noexcept;
-constexpr bool operator< (const month_day& x, const month_day& y) noexcept;
-constexpr bool operator> (const month_day& x, const month_day& y) noexcept;
-constexpr bool operator<=(const month_day& x, const month_day& y) noexcept;
-constexpr bool operator>=(const month_day& x, const month_day& y) noexcept;
-
-
-// 25.8.10, class month_day_last    // C++20
-class month_day_last;
-
-constexpr bool operator==(const month_day_last& x, const month_day_last& y) noexcept;
-constexpr bool operator!=(const month_day_last& x, const month_day_last& y) noexcept;
-constexpr bool operator< (const month_day_last& x, const month_day_last& y) noexcept;
-constexpr bool operator> (const month_day_last& x, const month_day_last& y) noexcept;
-constexpr bool operator<=(const month_day_last& x, const month_day_last& y) noexcept;
-constexpr bool operator>=(const month_day_last& x, const month_day_last& y) noexcept;
-
-// 25.8.11, class month_weekday    // C++20
-class month_weekday;
-
-constexpr bool operator==(const month_weekday& x, const month_weekday& y) noexcept;
-constexpr bool operator!=(const month_weekday& x, const month_weekday& y) noexcept;
-
-// 25.8.12, class month_weekday_last    // C++20
-class month_weekday_last;
-
-constexpr bool operator==(const month_weekday_last& x, const month_weekday_last& y) noexcept;
-constexpr bool operator!=(const month_weekday_last& x, const month_weekday_last& y) noexcept;
-
-
-// 25.8.13, class year_month    // C++20
-class year_month;
-
-constexpr bool operator==(const year_month& x, const year_month& y) noexcept;
-constexpr bool operator!=(const year_month& x, const year_month& y) noexcept;
-constexpr bool operator< (const year_month& x, const year_month& y) noexcept;
-constexpr bool operator> (const year_month& x, const year_month& y) noexcept;
-constexpr bool operator<=(const year_month& x, const year_month& y) noexcept;
-constexpr bool operator>=(const year_month& x, const year_month& y) noexcept;
-
-constexpr year_month operator+(const year_month& ym, const months& dm) noexcept;
-constexpr year_month operator+(const months& dm, const year_month& ym) noexcept;
-constexpr year_month operator-(const year_month& ym, const months& dm) noexcept;
-constexpr months operator-(const year_month& x, const year_month& y) noexcept;
-constexpr year_month operator+(const year_month& ym, const years& dy) noexcept;
-constexpr year_month operator+(const years& dy, const year_month& ym) noexcept;
-constexpr year_month operator-(const year_month& ym, const years& dy) noexcept;
-
-// 25.8.14, class year_month_day class    // C++20
-year_month_day;
-
-constexpr bool operator==(const year_month_day& x, const year_month_day& y) noexcept;
-constexpr bool operator!=(const year_month_day& x, const year_month_day& y) noexcept;
-constexpr bool operator< (const year_month_day& x, const year_month_day& y) noexcept;
-constexpr bool operator> (const year_month_day& x, const year_month_day& y) noexcept;
-constexpr bool operator<=(const year_month_day& x, const year_month_day& y) noexcept;
-constexpr bool operator>=(const year_month_day& x, const year_month_day& y) noexcept;
-
-constexpr year_month_day operator+(const year_month_day& ymd, const months& dm) noexcept;
-constexpr year_month_day operator+(const months& dm, const year_month_day& ymd) noexcept;
-constexpr year_month_day operator+(const year_month_day& ymd, const years& dy) noexcept;
-constexpr year_month_day operator+(const years& dy, const year_month_day& ymd) noexcept;
-constexpr year_month_day operator-(const year_month_day& ymd, const months& dm) noexcept;
-constexpr year_month_day operator-(const year_month_day& ymd, const years& dy) noexcept;
-
-
-// 25.8.15, class year_month_day_last    // C++20
-class year_month_day_last;
-
-constexpr bool operator==(const year_month_day_last& x,
-                          const year_month_day_last& y) noexcept;
-constexpr bool operator!=(const year_month_day_last& x,
-                          const year_month_day_last& y) noexcept;
-constexpr bool operator< (const year_month_day_last& x,
-                          const year_month_day_last& y) noexcept;
-constexpr bool operator> (const year_month_day_last& x,
-                          const year_month_day_last& y) noexcept;
-constexpr bool operator<=(const year_month_day_last& x,
-                          const year_month_day_last& y) noexcept;
-constexpr bool operator>=(const year_month_day_last& x,
-                          const year_month_day_last& y) noexcept;
-
-constexpr year_month_day_last
-  operator+(const year_month_day_last& ymdl, const months& dm) noexcept;
-constexpr year_month_day_last
-  operator+(const months& dm, const year_month_day_last& ymdl) noexcept;
-constexpr year_month_day_last
-  operator+(const year_month_day_last& ymdl, const years& dy) noexcept;
-constexpr year_month_day_last
-  operator+(const years& dy, const year_month_day_last& ymdl) noexcept;
-constexpr year_month_day_last
-  operator-(const year_month_day_last& ymdl, const months& dm) noexcept;
-constexpr year_month_day_last
-  operator-(const year_month_day_last& ymdl, const years& dy) noexcept;
-
-// 25.8.16, class year_month_weekday    // C++20
-class year_month_weekday;
-
-constexpr bool operator==(const year_month_weekday& x,
-                          const year_month_weekday& y) noexcept;
-constexpr bool operator!=(const year_month_weekday& x,
-                          const year_month_weekday& y) noexcept;
-
-constexpr year_month_weekday
-  operator+(const year_month_weekday& ymwd, const months& dm) noexcept;
-constexpr year_month_weekday
-  operator+(const months& dm, const year_month_weekday& ymwd) noexcept;
-constexpr year_month_weekday
-  operator+(const year_month_weekday& ymwd, const years& dy) noexcept;
-constexpr year_month_weekday
-  operator+(const years& dy, const year_month_weekday& ymwd) noexcept;
-constexpr year_month_weekday
-  operator-(const year_month_weekday& ymwd, const months& dm) noexcept;
-constexpr year_month_weekday
-  operator-(const year_month_weekday& ymwd, const years& dy) noexcept;
-
-// 25.8.17, class year_month_weekday_last    // C++20
-class year_month_weekday_last;
-
-constexpr bool operator==(const year_month_weekday_last& x,
-                          const year_month_weekday_last& y) noexcept;
-constexpr bool operator!=(const year_month_weekday_last& x,
-                          const year_month_weekday_last& y) noexcept;
-constexpr year_month_weekday_last
-  operator+(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
-constexpr year_month_weekday_last
-  operator+(const months& dm, const year_month_weekday_last& ymwdl) noexcept;
-constexpr year_month_weekday_last
-  operator+(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
-constexpr year_month_weekday_last
-  operator+(const years& dy, const year_month_weekday_last& ymwdl) noexcept;
-constexpr year_month_weekday_last
-  operator-(const year_month_weekday_last& ymwdl, const months& dm) noexcept;
-constexpr year_month_weekday_last
-  operator-(const year_month_weekday_last& ymwdl, const years& dy) noexcept;
-
-// 25.8.18, civil calendar conventional syntax operators    // C++20
-constexpr year_month
-  operator/(const year& y, const month& m) noexcept;
-constexpr year_month
-  operator/(const year& y, int m) noexcept;
-constexpr month_day
-  operator/(const month& m, const day& d) noexcept;
-constexpr month_day
-  operator/(const month& m, int d) noexcept;
-constexpr month_day
-  operator/(int m, const day& d) noexcept;
-constexpr month_day
-  operator/(const day& d, const month& m) noexcept;
-constexpr month_day
-  operator/(const day& d, int m) noexcept;
-constexpr month_day_last
-  operator/(const month& m, last_spec) noexcept;
-constexpr month_day_last
-  operator/(int m, last_spec) noexcept;
-constexpr month_day_last
-  operator/(last_spec, const month& m) noexcept;
-constexpr month_day_last
-  operator/(last_spec, int m) noexcept;
-constexpr month_weekday
-  operator/(const month& m, const weekday_indexed& wdi) noexcept;
-constexpr month_weekday
-  operator/(int m, const weekday_indexed& wdi) noexcept;
-constexpr month_weekday
-  operator/(const weekday_indexed& wdi, const month& m) noexcept;
-constexpr month_weekday
-  operator/(const weekday_indexed& wdi, int m) noexcept;
-constexpr month_weekday_last
-  operator/(const month& m, const weekday_last& wdl) noexcept;
-constexpr month_weekday_last
-  operator/(int m, const weekday_last& wdl) noexcept;
-constexpr month_weekday_last
-  operator/(const weekday_last& wdl, const month& m) noexcept;
-constexpr month_weekday_last
-  operator/(const weekday_last& wdl, int m) noexcept;
-constexpr year_month_day
-  operator/(const year_month& ym, const day& d) noexcept;
-constexpr year_month_day
-  operator/(const year_month& ym, int d) noexcept;
-constexpr year_month_day
-  operator/(const year& y, const month_day& md) noexcept;
-constexpr year_month_day
-  operator/(int y, const month_day& md) noexcept;
-constexpr year_month_day
-  operator/(const month_day& md, const year& y) noexcept;
-constexpr year_month_day
-  operator/(const month_day& md, int y) noexcept;
-constexpr year_month_day_last
-  operator/(const year_month& ym, last_spec) noexcept;
-constexpr year_month_day_last
-  operator/(const year& y, const month_day_last& mdl) noexcept;
-constexpr year_month_day_last
-  operator/(int y, const month_day_last& mdl) noexcept;
-constexpr year_month_day_last
-  operator/(const month_day_last& mdl, const year& y) noexcept;
-constexpr year_month_day_last
-  operator/(const month_day_last& mdl, int y) noexcept;
-constexpr year_month_weekday
-  operator/(const year_month& ym, const weekday_indexed& wdi) noexcept;
-constexpr year_month_weekday
-  operator/(const year& y, const month_weekday& mwd) noexcept;
-constexpr year_month_weekday
-  operator/(int y, const month_weekday& mwd) noexcept;
-constexpr year_month_weekday
-  operator/(const month_weekday& mwd, const year& y) noexcept;
-constexpr year_month_weekday
-  operator/(const month_weekday& mwd, int y) noexcept;
-constexpr year_month_weekday_last
-  operator/(const year_month& ym, const weekday_last& wdl) noexcept;
-constexpr year_month_weekday_last
-  operator/(const year& y, const month_weekday_last& mwdl) noexcept;
-constexpr year_month_weekday_last
-  operator/(int y, const month_weekday_last& mwdl) noexcept;
-constexpr year_month_weekday_last
-  operator/(const month_weekday_last& mwdl, const year& y) noexcept;
-constexpr year_month_weekday_last
-  operator/(const month_weekday_last& mwdl, int y) noexcept;
-
-// 25.9, class template time_of_day    // C++20
-template<class Duration> class time_of_day;
-
-template<> class time_of_day<hours>;
-template<> class time_of_day<minutes>;
-template<> class time_of_day<seconds>;
-template<class Rep, class Period> class time_of_day<duration<Rep, Period>>;
-
-// 25.10.2, time zone database     // C++20
-struct tzdb;
-class tzdb_list;
-
-// 25.10.2.3, time zone database access    // C++20
-const tzdb& get_tzdb();
-tzdb_list& get_tzdb_list();
-const time_zone* locate_zone(string_view tz_name);
-const time_zone* current_zone();
-
-// 25.10.2.4, remote time zone database support    // C++20
-const tzdb& reload_tzdb();
-string remote_version();
-
-// 25.10.3, exception classes    // C++20
-class nonexistent_local_time;
-class ambiguous_local_time;
-
-// 25.10.4, information classes    // C++20
-struct sys_info;
-struct local_info;
-
-// 25.10.5, class time_zone    // C++20
-enum class choose {earliest, latest};
-class time_zone;
-bool operator==(const time_zone& x, const time_zone& y) noexcept;
-bool operator!=(const time_zone& x, const time_zone& y) noexcept;
-bool operator<(const time_zone& x, const time_zone& y) noexcept;
-bool operator>(const time_zone& x, const time_zone& y) noexcept;
-bool operator<=(const time_zone& x, const time_zone& y) noexcept;
-bool operator>=(const time_zone& x, const time_zone& y) noexcept;
-
-// 25.10.6, class template zoned_traits    // C++20
-template<class T> struct zoned_traits;
-
-// 25.10.7, class template zoned_time    // C++20
-template<class Duration, class TimeZonePtr = const time_zone*> class zoned_time;
-using zoned_seconds = zoned_time<seconds>;
-
-template<class Duration1, class Duration2, class TimeZonePtr>
-  bool operator==(const zoned_time<Duration1, TimeZonePtr>& x,
-                  const zoned_time<Duration2, TimeZonePtr>& y);
-template<class Duration1, class Duration2, class TimeZonePtr>
-  bool operator!=(const zoned_time<Duration1, TimeZonePtr>& x,
-                  const zoned_time<Duration2, TimeZonePtr>& y);
-
-// 25.10.8, leap second support    // C++20
-class leap;
-
-bool operator==(const leap& x, const leap& y);
-bool operator!=(const leap& x, const leap& y);
-bool operator< (const leap& x, const leap& y);
-bool operator> (const leap& x, const leap& y);
-bool operator<=(const leap& x, const leap& y);
-bool operator>=(const leap& x, const leap& y);
-template<class Duration>
-  bool operator==(const leap& x, const sys_time<Duration>& y);
-template<class Duration>
-  bool operator==(const sys_time<Duration>& x, const leap& y);
-template<class Duration>
-  bool operator!=(const leap& x, const sys_time<Duration>& y);
-template<class Duration>
-  bool operator!=(const sys_time<Duration>& x, const leap& y);
-template<class Duration>
-  bool operator< (const leap& x, const sys_time<Duration>& y);
-template<class Duration>
-  bool operator< (const sys_time<Duration>& x, const leap& y);
-template<class Duration>
-  bool operator> (const leap& x, const sys_time<Duration>& y);
-template<class Duration>
-  bool operator> (const sys_time<Duration>& x, const leap& y);
-template<class Duration>
-  bool operator<=(const leap& x, const sys_time<Duration>& y);
-template<class Duration>
-  bool operator<=(const sys_time<Duration>& x, const leap& y);
-template<class Duration>
-  bool operator>=(const leap& x, const sys_time<Duration>& y);
-template<class Duration>
-  bool operator>=(const sys_time<Duration>& x, const leap& y);
-
-// 25.10.9, class link    // C++20
-class link;
-bool operator==(const link& x, const link& y);
-bool operator!=(const link& x, const link& y);
-bool operator< (const link& x, const link& y);
-bool operator> (const link& x, const link& y);
-bool operator<=(const link& x, const link& y);
-bool operator>=(const link& x, const link& y);
-
-// 25.11, formatting    // C++20
-template<class charT, class Streamable>
-  basic_string<charT>
-    format(const charT* fmt, const Streamable& s);
-
-template<class charT, class Streamable>
-  basic_string<charT>
-    format(const locale& loc, const charT* fmt, const Streamable& s);
-
-template<class charT, class traits, class Alloc, class Streamable>
-  basic_string<charT, traits, Alloc>
-    format(const basic_string<charT, traits, Alloc>& fmt, const Streamable& s);
-
-template<class charT, class traits, class Alloc, class Streamable>
-  basic_string<charT, traits, Alloc>
-    format(const locale& loc, const basic_string<charT, traits, Alloc>& fmt,
-           const Streamable& s);
-
-// 25.12, parsing    // C++20
-template<class charT, class traits, class Alloc, class Parsable>
-unspecified
-    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp);
-
-template<class charT, class traits, class Alloc, class Parsable>
-unspecified
-    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp,
-          basic_string<charT, traits, Alloc>& abbrev);
-
-template<class charT, class traits, class Alloc, class Parsable>
-unspecified
-    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp,
-          minutes& offset);
-
-template<class charT, class traits, class Alloc, class Parsable>
-unspecified
-    parse(const basic_string<charT, traits, Alloc>& format, Parsable& tp,
-          basic_string<charT, traits, Alloc>& abbrev, minutes& offset);
-
-// calendrical constants
-inline constexpr last_spec                              last{};       // C++20
-inline constexpr chrono::weekday                        Sunday{0};    // C++20
-inline constexpr chrono::weekday                        Monday{1};    // C++20
-inline constexpr chrono::weekday                        Tuesday{2};   // C++20
-inline constexpr chrono::weekday                        Wednesday{3}; // C++20
-inline constexpr chrono::weekday                        Thursday{4};  // C++20
-inline constexpr chrono::weekday                        Friday{5};    // C++20
-inline constexpr chrono::weekday                        Saturday{6};  // C++20
-
-inline constexpr chrono::month                          January{1};   // C++20
-inline constexpr chrono::month                          February{2};  // C++20
-inline constexpr chrono::month                          March{3};     // C++20
-inline constexpr chrono::month                          April{4};     // C++20
-inline constexpr chrono::month                          May{5};       // C++20
-inline constexpr chrono::month                          June{6};      // C++20
-inline constexpr chrono::month                          July{7};      // C++20
-inline constexpr chrono::month                          August{8};    // C++20
-inline constexpr chrono::month                          September{9}; // C++20
-inline constexpr chrono::month                          October{10};  // C++20
-inline constexpr chrono::month                          November{11}; // C++20
-inline constexpr chrono::month                          December{12}; // C++20
-}  // chrono
-
-inline namespace literals {
-  inline namespace chrono_literals {
-constexpr chrono::hours                                 operator ""h(unsigned long long); // C++14
-constexpr chrono::duration<unspecified , ratio<3600,1>> operator ""h(long double); // C++14
-constexpr chrono::minutes                               operator ""min(unsigned long long); // C++14
-constexpr chrono::duration<unspecified , ratio<60,1>>   operator ""min(long double); // C++14
-constexpr chrono::seconds                               operator ""s(unsigned long long); // C++14
-constexpr chrono::duration<unspecified >                operator ""s(long double); // C++14
-constexpr chrono::milliseconds                          operator ""ms(unsigned long long); // C++14
-constexpr chrono::duration<unspecified , milli>         operator ""ms(long double); // C++14
-constexpr chrono::microseconds                          operator ""us(unsigned long long); // C++14
-constexpr chrono::duration<unspecified , micro>         operator ""us(long double); // C++14
-constexpr chrono::nanoseconds                           operator ""ns(unsigned long long); // C++14
-constexpr chrono::duration<unspecified , nano>          operator ""ns(long double); // C++14
-constexpr chrono::day                                   operator ""d(unsigned long long d) noexcept; // C++20
-constexpr chrono::year                                  operator ""y(unsigned long long y) noexcept; // C++20
-}  // chrono_literals
-}  // literals
-
-}  // std
-*/
-
-#include <__config>
-#include <ctime>
-#include <type_traits>
-#include <ratio>
-#include <limits>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-#ifndef _LIBCPP_CXX03_LANG
-_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
-struct _FilesystemClock;
-_LIBCPP_END_NAMESPACE_FILESYSTEM
-#endif // !_LIBCPP_CXX03_LANG
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-namespace chrono
-{
-
-template <class _Rep, class _Period = ratio<1> > class _LIBCPP_TEMPLATE_VIS duration;
-
-template <class _Tp>
-struct __is_duration : false_type {};
-
-template <class _Rep, class _Period>
-struct __is_duration<duration<_Rep, _Period> > : true_type  {};
-
-template <class _Rep, class _Period>
-struct __is_duration<const duration<_Rep, _Period> > : true_type  {};
-
-template <class _Rep, class _Period>
-struct __is_duration<volatile duration<_Rep, _Period> > : true_type  {};
-
-template <class _Rep, class _Period>
-struct __is_duration<const volatile duration<_Rep, _Period> > : true_type  {};
-
-} // chrono
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-struct _LIBCPP_TEMPLATE_VIS common_type<chrono::duration<_Rep1, _Period1>,
-                                         chrono::duration<_Rep2, _Period2> >
-{
-    typedef chrono::duration<typename common_type<_Rep1, _Rep2>::type,
-                             typename __ratio_gcd<_Period1, _Period2>::type> type;
-};
-
-namespace chrono {
-
-// duration_cast
-
-template <class _FromDuration, class _ToDuration,
-          class _Period = typename ratio_divide<typename _FromDuration::period, typename _ToDuration::period>::type,
-          bool = _Period::num == 1,
-          bool = _Period::den == 1>
-struct __duration_cast;
-
-template <class _FromDuration, class _ToDuration, class _Period>
-struct __duration_cast<_FromDuration, _ToDuration, _Period, true, true>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    _ToDuration operator()(const _FromDuration& __fd) const
-    {
-        return _ToDuration(static_cast<typename _ToDuration::rep>(__fd.count()));
-    }
-};
-
-template <class _FromDuration, class _ToDuration, class _Period>
-struct __duration_cast<_FromDuration, _ToDuration, _Period, true, false>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    _ToDuration operator()(const _FromDuration& __fd) const
-    {
-        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
-        return _ToDuration(static_cast<typename _ToDuration::rep>(
-                           static_cast<_Ct>(__fd.count()) / static_cast<_Ct>(_Period::den)));
-    }
-};
-
-template <class _FromDuration, class _ToDuration, class _Period>
-struct __duration_cast<_FromDuration, _ToDuration, _Period, false, true>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    _ToDuration operator()(const _FromDuration& __fd) const
-    {
-        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
-        return _ToDuration(static_cast<typename _ToDuration::rep>(
-                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)));
-    }
-};
-
-template <class _FromDuration, class _ToDuration, class _Period>
-struct __duration_cast<_FromDuration, _ToDuration, _Period, false, false>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    _ToDuration operator()(const _FromDuration& __fd) const
-    {
-        typedef typename common_type<typename _ToDuration::rep, typename _FromDuration::rep, intmax_t>::type _Ct;
-        return _ToDuration(static_cast<typename _ToDuration::rep>(
-                           static_cast<_Ct>(__fd.count()) * static_cast<_Ct>(_Period::num)
-                                                          / static_cast<_Ct>(_Period::den)));
-    }
-};
-
-template <class _ToDuration, class _Rep, class _Period>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-typename enable_if
-<
-    __is_duration<_ToDuration>::value,
-    _ToDuration
->::type
-duration_cast(const duration<_Rep, _Period>& __fd)
-{
-    return __duration_cast<duration<_Rep, _Period>, _ToDuration>()(__fd);
-}
-
-template <class _Rep>
-struct _LIBCPP_TEMPLATE_VIS treat_as_floating_point : is_floating_point<_Rep> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Rep>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool treat_as_floating_point_v
-    = treat_as_floating_point<_Rep>::value;
-#endif
-
-template <class _Rep>
-struct _LIBCPP_TEMPLATE_VIS duration_values
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep zero() _NOEXCEPT {return _Rep(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep max()  _NOEXCEPT {return numeric_limits<_Rep>::max();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR _Rep min()  _NOEXCEPT {return numeric_limits<_Rep>::lowest();}
-};
-
-#if _LIBCPP_STD_VER > 14
-template <class _ToDuration, class _Rep, class _Period>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    __is_duration<_ToDuration>::value,
-    _ToDuration
->::type
-floor(const duration<_Rep, _Period>& __d)
-{
-    _ToDuration __t = duration_cast<_ToDuration>(__d);
-    if (__t > __d)
-        __t = __t - _ToDuration{1};
-    return __t;
-}
-
-template <class _ToDuration, class _Rep, class _Period>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    __is_duration<_ToDuration>::value,
-    _ToDuration
->::type
-ceil(const duration<_Rep, _Period>& __d)
-{
-    _ToDuration __t = duration_cast<_ToDuration>(__d);
-    if (__t < __d)
-        __t = __t + _ToDuration{1};
-    return __t;
-}
-
-template <class _ToDuration, class _Rep, class _Period>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    __is_duration<_ToDuration>::value,
-    _ToDuration
->::type
-round(const duration<_Rep, _Period>& __d)
-{
-    _ToDuration __lower = floor<_ToDuration>(__d);
-    _ToDuration __upper = __lower + _ToDuration{1};
-    auto __lowerDiff = __d - __lower;
-    auto __upperDiff = __upper - __d;
-    if (__lowerDiff < __upperDiff)
-        return __lower;
-    if (__lowerDiff > __upperDiff)
-        return __upper;
-    return __lower.count() & 1 ? __upper : __lower;
-}
-#endif
-
-// duration
-
-template <class _Rep, class _Period>
-class _LIBCPP_TEMPLATE_VIS duration
-{
-    static_assert(!__is_duration<_Rep>::value, "A duration representation can not be a duration");
-    static_assert(__is_ratio<_Period>::value, "Second template parameter of duration must be a std::ratio");
-    static_assert(_Period::num > 0, "duration period must be positive");
-
-    template <class _R1, class _R2>
-    struct __no_overflow
-    {
-    private:
-        static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
-        static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
-        static const intmax_t __n1 = _R1::num / __gcd_n1_n2;
-        static const intmax_t __d1 = _R1::den / __gcd_d1_d2;
-        static const intmax_t __n2 = _R2::num / __gcd_n1_n2;
-        static const intmax_t __d2 = _R2::den / __gcd_d1_d2;
-        static const intmax_t max = -((intmax_t(1) << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1);
-
-        template <intmax_t _Xp, intmax_t _Yp, bool __overflow>
-        struct __mul    // __overflow == false
-        {
-            static const intmax_t value = _Xp * _Yp;
-        };
-
-        template <intmax_t _Xp, intmax_t _Yp>
-        struct __mul<_Xp, _Yp, true>
-        {
-            static const intmax_t value = 1;
-        };
-
-    public:
-        static const bool value = (__n1 <= max / __d2) && (__n2 <= max / __d1);
-        typedef ratio<__mul<__n1, __d2, !value>::value,
-                      __mul<__n2, __d1, !value>::value> type;
-    };
-
-public:
-    typedef _Rep rep;
-    typedef typename _Period::type period;
-private:
-    rep __rep_;
-public:
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-#ifndef _LIBCPP_CXX03_LANG
-        duration() = default;
-#else
-        duration() {}
-#endif
-
-    template <class _Rep2>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-        explicit duration(const _Rep2& __r,
-            typename enable_if
-            <
-               is_convertible<_Rep2, rep>::value &&
-               (treat_as_floating_point<rep>::value ||
-               !treat_as_floating_point<_Rep2>::value)
-            >::type* = 0)
-                : __rep_(__r) {}
-
-    // conversions
-    template <class _Rep2, class _Period2>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-        duration(const duration<_Rep2, _Period2>& __d,
-            typename enable_if
-            <
-                __no_overflow<_Period2, period>::value && (
-                treat_as_floating_point<rep>::value ||
-                (__no_overflow<_Period2, period>::type::den == 1 &&
-                 !treat_as_floating_point<_Rep2>::value))
-            >::type* = 0)
-                : __rep_(_VSTD::chrono::duration_cast<duration>(__d).count()) {}
-
-    // observer
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR rep count() const {return __rep_;}
-
-    // arithmetic
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator+() const {return typename common_type<duration>::type(*this);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR typename common_type<duration>::type operator-() const {return typename common_type<duration>::type(-__rep_);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator++()      {++__rep_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator++(int)   {return duration(__rep_++);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator--()      {--__rep_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration  operator--(int)   {return duration(__rep_--);}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator+=(const duration& __d) {__rep_ += __d.count(); return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator-=(const duration& __d) {__rep_ -= __d.count(); return *this;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator*=(const rep& rhs) {__rep_ *= rhs; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator/=(const rep& rhs) {__rep_ /= rhs; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator%=(const rep& rhs) {__rep_ %= rhs; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 duration& operator%=(const duration& rhs) {__rep_ %= rhs.count(); return *this;}
-
-    // special values
-
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration zero() _NOEXCEPT {return duration(duration_values<rep>::zero());}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration min()  _NOEXCEPT {return duration(duration_values<rep>::min());}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR duration max()  _NOEXCEPT {return duration(duration_values<rep>::max());}
-};
-
-typedef duration<long long,         nano> nanoseconds;
-typedef duration<long long,        micro> microseconds;
-typedef duration<long long,        milli> milliseconds;
-typedef duration<long long              > seconds;
-typedef duration<     long, ratio<  60> > minutes;
-typedef duration<     long, ratio<3600> > hours;
-#if _LIBCPP_STD_VER > 17
-typedef duration<     int, ratio_multiply<ratio<24>, hours::period>>         days;
-typedef duration<     int, ratio_multiply<ratio<7>,   days::period>>         weeks;
-typedef duration<     int, ratio_multiply<ratio<146097, 400>, days::period>> years;
-typedef duration<     int, ratio_divide<years::period, ratio<12>>>           months;
-#endif
-// Duration ==
-
-template <class _LhsDuration, class _RhsDuration>
-struct __duration_eq
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
-        {
-            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
-            return _Ct(__lhs).count() == _Ct(__rhs).count();
-        }
-};
-
-template <class _LhsDuration>
-struct __duration_eq<_LhsDuration, _LhsDuration>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
-        {return __lhs.count() == __rhs.count();}
-};
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-bool
-operator==(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    return __duration_eq<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
-}
-
-// Duration !=
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-bool
-operator!=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    return !(__lhs == __rhs);
-}
-
-// Duration <
-
-template <class _LhsDuration, class _RhsDuration>
-struct __duration_lt
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    bool operator()(const _LhsDuration& __lhs, const _RhsDuration& __rhs) const
-        {
-            typedef typename common_type<_LhsDuration, _RhsDuration>::type _Ct;
-            return _Ct(__lhs).count() < _Ct(__rhs).count();
-        }
-};
-
-template <class _LhsDuration>
-struct __duration_lt<_LhsDuration, _LhsDuration>
-{
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    bool operator()(const _LhsDuration& __lhs, const _LhsDuration& __rhs) const
-        {return __lhs.count() < __rhs.count();}
-};
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-bool
-operator< (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    return __duration_lt<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >()(__lhs, __rhs);
-}
-
-// Duration >
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-bool
-operator> (const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    return __rhs < __lhs;
-}
-
-// Duration <=
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-bool
-operator<=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    return !(__rhs < __lhs);
-}
-
-// Duration >=
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-bool
-operator>=(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    return !(__lhs < __rhs);
-}
-
-// Duration +
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
-operator+(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
-    return _Cd(_Cd(__lhs).count() + _Cd(__rhs).count());
-}
-
-// Duration -
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
-operator-(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
-    return _Cd(_Cd(__lhs).count() - _Cd(__rhs).count());
-}
-
-// Duration *
-
-template <class _Rep1, class _Period, class _Rep2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-typename enable_if
-<
-    is_convertible<_Rep2, typename common_type<_Rep1, _Rep2>::type>::value,
-    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
->::type
-operator*(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
-{
-    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
-    typedef duration<_Cr, _Period> _Cd;
-    return _Cd(_Cd(__d).count() * static_cast<_Cr>(__s));
-}
-
-template <class _Rep1, class _Period, class _Rep2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-typename enable_if
-<
-    is_convertible<_Rep1, typename common_type<_Rep1, _Rep2>::type>::value,
-    duration<typename common_type<_Rep1, _Rep2>::type, _Period>
->::type
-operator*(const _Rep1& __s, const duration<_Rep2, _Period>& __d)
-{
-    return __d * __s;
-}
-
-// Duration /
-
-template <class _Duration, class _Rep, bool = __is_duration<_Rep>::value>
-struct __duration_divide_result
-{
-};
-
-template <class _Duration, class _Rep2,
-    bool = is_convertible<_Rep2,
-                          typename common_type<typename _Duration::rep, _Rep2>::type>::value>
-struct __duration_divide_imp
-{
-};
-
-template <class _Rep1, class _Period, class _Rep2>
-struct __duration_divide_imp<duration<_Rep1, _Period>, _Rep2, true>
-{
-    typedef duration<typename common_type<_Rep1, _Rep2>::type, _Period> type;
-};
-
-template <class _Rep1, class _Period, class _Rep2>
-struct __duration_divide_result<duration<_Rep1, _Period>, _Rep2, false>
-    : __duration_divide_imp<duration<_Rep1, _Period>, _Rep2>
-{
-};
-
-template <class _Rep1, class _Period, class _Rep2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
-operator/(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
-{
-    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
-    typedef duration<_Cr, _Period> _Cd;
-    return _Cd(_Cd(__d).count() / static_cast<_Cr>(__s));
-}
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-typename common_type<_Rep1, _Rep2>::type
-operator/(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Ct;
-    return _Ct(__lhs).count() / _Ct(__rhs).count();
-}
-
-// Duration %
-
-template <class _Rep1, class _Period, class _Rep2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-typename __duration_divide_result<duration<_Rep1, _Period>, _Rep2>::type
-operator%(const duration<_Rep1, _Period>& __d, const _Rep2& __s)
-{
-    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
-    typedef duration<_Cr, _Period> _Cd;
-    return _Cd(_Cd(__d).count() % static_cast<_Cr>(__s));
-}
-
-template <class _Rep1, class _Period1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type
-operator%(const duration<_Rep1, _Period1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    typedef typename common_type<_Rep1, _Rep2>::type _Cr;
-    typedef typename common_type<duration<_Rep1, _Period1>, duration<_Rep2, _Period2> >::type _Cd;
-    return _Cd(static_cast<_Cr>(_Cd(__lhs).count()) % static_cast<_Cr>(_Cd(__rhs).count()));
-}
-
-//////////////////////////////////////////////////////////
-///////////////////// time_point /////////////////////////
-//////////////////////////////////////////////////////////
-
-template <class _Clock, class _Duration = typename _Clock::duration>
-class _LIBCPP_TEMPLATE_VIS time_point
-{
-    static_assert(__is_duration<_Duration>::value,
-                  "Second template parameter of time_point must be a std::chrono::duration");
-public:
-    typedef _Clock                    clock;
-    typedef _Duration                 duration;
-    typedef typename duration::rep    rep;
-    typedef typename duration::period period;
-private:
-    duration __d_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 time_point() : __d_(duration::zero()) {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 explicit time_point(const duration& __d) : __d_(__d) {}
-
-    // conversions
-    template <class _Duration2>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    time_point(const time_point<clock, _Duration2>& t,
-        typename enable_if
-        <
-            is_convertible<_Duration2, duration>::value
-        >::type* = 0)
-            : __d_(t.time_since_epoch()) {}
-
-    // observer
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 duration time_since_epoch() const {return __d_;}
-
-    // arithmetic
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator+=(const duration& __d) {__d_ += __d; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 time_point& operator-=(const duration& __d) {__d_ -= __d; return *this;}
-
-    // special values
-
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point min() _NOEXCEPT {return time_point(duration::min());}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR time_point max() _NOEXCEPT {return time_point(duration::max());}
-};
-
-} // chrono
-
-template <class _Clock, class _Duration1, class _Duration2>
-struct _LIBCPP_TEMPLATE_VIS common_type<chrono::time_point<_Clock, _Duration1>,
-                                         chrono::time_point<_Clock, _Duration2> >
-{
-    typedef chrono::time_point<_Clock, typename common_type<_Duration1, _Duration2>::type> type;
-};
-
-namespace chrono {
-
-template <class _ToDuration, class _Clock, class _Duration>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-time_point<_Clock, _ToDuration>
-time_point_cast(const time_point<_Clock, _Duration>& __t)
-{
-    return time_point<_Clock, _ToDuration>(_VSTD::chrono::duration_cast<_ToDuration>(__t.time_since_epoch()));
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _ToDuration, class _Clock, class _Duration>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    __is_duration<_ToDuration>::value,
-    time_point<_Clock, _ToDuration>
->::type
-floor(const time_point<_Clock, _Duration>& __t)
-{
-    return time_point<_Clock, _ToDuration>{floor<_ToDuration>(__t.time_since_epoch())};
-}
-
-template <class _ToDuration, class _Clock, class _Duration>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    __is_duration<_ToDuration>::value,
-    time_point<_Clock, _ToDuration>
->::type
-ceil(const time_point<_Clock, _Duration>& __t)
-{
-    return time_point<_Clock, _ToDuration>{ceil<_ToDuration>(__t.time_since_epoch())};
-}
-
-template <class _ToDuration, class _Clock, class _Duration>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    __is_duration<_ToDuration>::value,
-    time_point<_Clock, _ToDuration>
->::type
-round(const time_point<_Clock, _Duration>& __t)
-{
-    return time_point<_Clock, _ToDuration>{round<_ToDuration>(__t.time_since_epoch())};
-}
-
-template <class _Rep, class _Period>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if
-<
-    numeric_limits<_Rep>::is_signed,
-    duration<_Rep, _Period>
->::type
-abs(duration<_Rep, _Period> __d)
-{
-    return __d >= __d.zero() ? __d : -__d;
-}
-#endif
-
-// time_point ==
-
-template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator==(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
-{
-    return __lhs.time_since_epoch() == __rhs.time_since_epoch();
-}
-
-// time_point !=
-
-template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator!=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
-{
-    return !(__lhs == __rhs);
-}
-
-// time_point <
-
-template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator<(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
-{
-    return __lhs.time_since_epoch() < __rhs.time_since_epoch();
-}
-
-// time_point >
-
-template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator>(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
-{
-    return __rhs < __lhs;
-}
-
-// time_point <=
-
-template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator<=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
-{
-    return !(__rhs < __lhs);
-}
-
-// time_point >=
-
-template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator>=(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
-{
-    return !(__lhs < __rhs);
-}
-
-// time_point operator+(time_point x, duration y);
-
-template <class _Clock, class _Duration1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
-operator+(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Tr;
-    return _Tr (__lhs.time_since_epoch() + __rhs);
-}
-
-// time_point operator+(duration x, time_point y);
-
-template <class _Rep1, class _Period1, class _Clock, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-time_point<_Clock, typename common_type<duration<_Rep1, _Period1>, _Duration2>::type>
-operator+(const duration<_Rep1, _Period1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
-{
-    return __rhs + __lhs;
-}
-
-// time_point operator-(time_point x, duration y);
-
-template <class _Clock, class _Duration1, class _Rep2, class _Period2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type>
-operator-(const time_point<_Clock, _Duration1>& __lhs, const duration<_Rep2, _Period2>& __rhs)
-{
-    typedef time_point<_Clock, typename common_type<_Duration1, duration<_Rep2, _Period2> >::type> _Ret;
-    return _Ret(__lhs.time_since_epoch() -__rhs);
-}
-
-// duration operator-(time_point x, time_point y);
-
-template <class _Clock, class _Duration1, class _Duration2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename common_type<_Duration1, _Duration2>::type
-operator-(const time_point<_Clock, _Duration1>& __lhs, const time_point<_Clock, _Duration2>& __rhs)
-{
-    return __lhs.time_since_epoch() - __rhs.time_since_epoch();
-}
-
-//////////////////////////////////////////////////////////
-/////////////////////// clocks ///////////////////////////
-//////////////////////////////////////////////////////////
-
-class _LIBCPP_TYPE_VIS system_clock
-{
-public:
-    typedef microseconds                     duration;
-    typedef duration::rep                    rep;
-    typedef duration::period                 period;
-    typedef chrono::time_point<system_clock> time_point;
-    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
-
-    static time_point now() _NOEXCEPT;
-    static time_t     to_time_t  (const time_point& __t) _NOEXCEPT;
-    static time_point from_time_t(time_t __t) _NOEXCEPT;
-};
-
-#ifndef _LIBCPP_HAS_NO_MONOTONIC_CLOCK
-class _LIBCPP_TYPE_VIS steady_clock
-{
-public:
-    typedef nanoseconds                                   duration;
-    typedef duration::rep                                 rep;
-    typedef duration::period                              period;
-    typedef chrono::time_point<steady_clock, duration>    time_point;
-    static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = true;
-
-    static time_point now() _NOEXCEPT;
-};
-
-typedef steady_clock high_resolution_clock;
-#else
-typedef system_clock high_resolution_clock;
-#endif
-
-#if _LIBCPP_STD_VER > 17
-// [time.clock.file], type file_clock
-using file_clock = _VSTD_FS::_FilesystemClock;
-
-template<class _Duration>
-using file_time = time_point<file_clock, _Duration>;
-
-
-template <class _Duration>
-using sys_time    = time_point<system_clock, _Duration>;
-using sys_seconds = sys_time<seconds>;
-using sys_days    = sys_time<days>;
-
-struct local_t {};
-template<class Duration>
-using local_time  = time_point<local_t, Duration>;
-using local_seconds = local_time<seconds>;
-using local_days    = local_time<days>;
-
-
-struct _LIBCPP_TYPE_VIS last_spec { explicit last_spec() = default; };
-
-class _LIBCPP_TYPE_VIS day {
-private:
-    unsigned char __d;
-public:
-    day() = default;
-    explicit inline constexpr day(unsigned __val) noexcept : __d(static_cast<unsigned char>(__val)) {}
-    inline constexpr day& operator++()    noexcept { ++__d; return *this; }
-    inline constexpr day  operator++(int) noexcept { day __tmp = *this; ++(*this); return __tmp; }
-    inline constexpr day& operator--()    noexcept { --__d; return *this; }
-    inline constexpr day  operator--(int) noexcept { day __tmp = *this; --(*this); return __tmp; }
-           constexpr day& operator+=(const days& __dd) noexcept;
-           constexpr day& operator-=(const days& __dd) noexcept;
-    explicit inline constexpr operator unsigned() const noexcept { return __d; }
-    inline constexpr bool ok() const noexcept { return __d >= 1 && __d <= 31; }
-  };
-
-
-inline constexpr
-bool operator==(const day& __lhs, const day& __rhs) noexcept
-{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
-
-inline constexpr
-bool operator!=(const day& __lhs, const day& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-bool operator< (const day& __lhs, const day& __rhs) noexcept
-{ return static_cast<unsigned>(__lhs) <  static_cast<unsigned>(__rhs); }
-
-inline constexpr
-bool operator> (const day& __lhs, const day& __rhs) noexcept
-{ return __rhs < __lhs; }
-
-inline constexpr
-bool operator<=(const day& __lhs, const day& __rhs) noexcept
-{ return !(__rhs < __lhs);}
-
-inline constexpr
-bool operator>=(const day& __lhs, const day& __rhs) noexcept
-{ return !(__lhs < __rhs); }
-
-inline constexpr
-day operator+ (const day& __lhs, const days& __rhs) noexcept
-{ return day(static_cast<unsigned>(__lhs) + __rhs.count()); }
-
-inline constexpr
-day operator+ (const days& __lhs, const day& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-day operator- (const day& __lhs, const days& __rhs) noexcept
-{ return __lhs + -__rhs; }
-
-inline constexpr
-days operator-(const day& __lhs, const day& __rhs) noexcept
-{ return days(static_cast<int>(static_cast<unsigned>(__lhs)) -
-              static_cast<int>(static_cast<unsigned>(__rhs))); }
-
-inline constexpr day& day::operator+=(const days& __dd) noexcept
-{ *this = *this + __dd; return *this; }
-
-inline constexpr day& day::operator-=(const days& __dd) noexcept
-{ *this = *this - __dd; return *this; }
-
-
-class _LIBCPP_TYPE_VIS month {
-private:
-    unsigned char __m;
-public:
-    month() = default;
-    explicit inline constexpr month(unsigned __val) noexcept : __m(static_cast<unsigned char>(__val)) {}
-    inline constexpr month& operator++()    noexcept { ++__m; return *this; }
-    inline constexpr month  operator++(int) noexcept { month __tmp = *this; ++(*this); return __tmp; }
-    inline constexpr month& operator--()    noexcept { --__m; return *this; }
-    inline constexpr month  operator--(int) noexcept { month __tmp = *this; --(*this); return __tmp; }
-           constexpr month& operator+=(const months& __m1) noexcept;
-           constexpr month& operator-=(const months& __m1) noexcept;
-    explicit inline constexpr operator unsigned() const noexcept { return __m; }
-    inline constexpr bool ok() const noexcept { return __m >= 1 && __m <= 12; }
-};
-
-
-inline constexpr
-bool operator==(const month& __lhs, const month& __rhs) noexcept
-{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
-
-inline constexpr
-bool operator!=(const month& __lhs, const month& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-bool operator< (const month& __lhs, const month& __rhs) noexcept
-{ return static_cast<unsigned>(__lhs)  < static_cast<unsigned>(__rhs); }
-
-inline constexpr
-bool operator> (const month& __lhs, const month& __rhs) noexcept
-{ return __rhs < __lhs; }
-
-inline constexpr
-bool operator<=(const month& __lhs, const month& __rhs) noexcept
-{ return !(__rhs < __lhs); }
-
-inline constexpr
-bool operator>=(const month& __lhs, const month& __rhs) noexcept
-{ return !(__lhs < __rhs); }
-
-inline constexpr
-month operator+ (const month& __lhs, const months& __rhs) noexcept
-{
-    auto const __mu = static_cast<long long>(static_cast<unsigned>(__lhs)) + (__rhs.count() - 1);
-    auto const __yr = (__mu >= 0 ? __mu : __mu - 11) / 12;
-    return month{static_cast<unsigned>(__mu - __yr * 12 + 1)};
-}
-
-inline constexpr
-month operator+ (const months& __lhs, const month& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-month operator- (const month& __lhs, const months& __rhs) noexcept
-{ return __lhs + -__rhs; }
-
-inline constexpr
-months operator-(const month& __lhs, const month& __rhs) noexcept
-{
-    auto const __dm = static_cast<unsigned>(__lhs) - static_cast<unsigned>(__rhs);
-    return months(__dm <= 11 ? __dm : __dm + 12);
-}
-
-inline constexpr month& month::operator+=(const months& __dm) noexcept
-{ *this = *this + __dm; return *this; }
-
-inline constexpr month& month::operator-=(const months& __dm) noexcept
-{ *this = *this - __dm; return *this; }
-
-
-class _LIBCPP_TYPE_VIS year {
-private:
-    short __y;
-public:
-    year() = default;
-    explicit inline constexpr year(int __val) noexcept : __y(static_cast<short>(__val)) {}
-
-    inline constexpr year& operator++()    noexcept { ++__y; return *this; };
-    inline constexpr year  operator++(int) noexcept { year __tmp = *this; ++(*this); return __tmp; };
-    inline constexpr year& operator--()    noexcept { --__y; return *this; };
-    inline constexpr year  operator--(int) noexcept { year __tmp = *this; --(*this); return __tmp; };
-           constexpr year& operator+=(const years& __dy) noexcept;
-           constexpr year& operator-=(const years& __dy) noexcept;
-    inline constexpr year operator+() const noexcept { return *this; }
-    inline constexpr year operator-() const noexcept { return year{-__y}; };
-
-    inline constexpr bool is_leap() const noexcept { return __y % 4 == 0 && (__y % 100 != 0 || __y % 400 == 0); }
-    explicit inline constexpr operator int() const noexcept { return __y; }
-           constexpr bool ok() const noexcept;
-    static inline constexpr year min() noexcept { return year{-32767}; }
-    static inline constexpr year max() noexcept { return year{ 32767}; }
-};
-
-
-inline constexpr
-bool operator==(const year& __lhs, const year& __rhs) noexcept
-{ return static_cast<int>(__lhs) == static_cast<int>(__rhs); }
-
-inline constexpr
-bool operator!=(const year& __lhs, const year& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-bool operator< (const year& __lhs, const year& __rhs) noexcept
-{ return static_cast<int>(__lhs)  < static_cast<int>(__rhs); }
-
-inline constexpr
-bool operator> (const year& __lhs, const year& __rhs) noexcept
-{ return __rhs < __lhs; }
-
-inline constexpr
-bool operator<=(const year& __lhs, const year& __rhs) noexcept
-{ return !(__rhs < __lhs); }
-
-inline constexpr
-bool operator>=(const year& __lhs, const year& __rhs) noexcept
-{ return !(__lhs < __rhs); }
-
-inline constexpr
-year operator+ (const year& __lhs, const years& __rhs) noexcept
-{ return year(static_cast<int>(__lhs) + __rhs.count()); }
-
-inline constexpr
-year operator+ (const years& __lhs, const year& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-year operator- (const year& __lhs, const years& __rhs) noexcept
-{ return __lhs + -__rhs; }
-
-inline constexpr
-years operator-(const year& __lhs, const year& __rhs) noexcept
-{ return years{static_cast<int>(__lhs) - static_cast<int>(__rhs)}; }
-
-
-inline constexpr year& year::operator+=(const years& __dy) noexcept
-{ *this = *this + __dy; return *this; }
-
-inline constexpr year& year::operator-=(const years& __dy) noexcept
-{ *this = *this - __dy; return *this; }
-
-inline constexpr bool year::ok() const noexcept
-{ return static_cast<int>(min()) <= __y && __y <= static_cast<int>(max()); }
-
-class _LIBCPP_TYPE_VIS weekday_indexed;
-class _LIBCPP_TYPE_VIS weekday_last;
-
-class _LIBCPP_TYPE_VIS weekday {
-private:
-    unsigned char __wd;
-public:
-  weekday() = default;
-  inline explicit constexpr weekday(unsigned __val) noexcept : __wd(static_cast<unsigned char>(__val)) {}
-  inline constexpr          weekday(const sys_days& __sysd) noexcept
-          : __wd(__weekday_from_days(__sysd.time_since_epoch().count())) {}
-  inline explicit constexpr weekday(const local_days& __locd) noexcept
-          : __wd(__weekday_from_days(__locd.time_since_epoch().count())) {}
-
-  inline constexpr weekday& operator++()    noexcept { __wd = (__wd == 6 ? 0 : __wd + 1); return *this; }
-  inline constexpr weekday  operator++(int) noexcept { weekday __tmp = *this; ++(*this); return __tmp; }
-  inline constexpr weekday& operator--()    noexcept { __wd = (__wd == 0 ? 6 : __wd - 1); return *this; }
-  inline constexpr weekday  operator--(int) noexcept { weekday __tmp = *this; --(*this); return __tmp; }
-         constexpr weekday& operator+=(const days& __dd) noexcept;
-         constexpr weekday& operator-=(const days& __dd) noexcept;
-  inline explicit constexpr operator unsigned() const noexcept { return __wd; }
-  inline constexpr bool ok() const noexcept { return __wd <= 6; }
-         constexpr weekday_indexed operator[](unsigned __index) const noexcept;
-         constexpr weekday_last    operator[](last_spec) const noexcept;
-
-  static constexpr unsigned char __weekday_from_days(int __days) noexcept;
-};
-
-
-// https://howardhinnant.github.io/date_algorithms.html#weekday_from_days
-inline constexpr
-unsigned char weekday::__weekday_from_days(int __days) noexcept
-{
-    return static_cast<unsigned char>(
-              static_cast<unsigned>(__days >= -4 ? (__days+4) % 7 : (__days+5) % 7 + 6)
-           );
-}
-
-inline constexpr
-bool operator==(const weekday& __lhs, const weekday& __rhs) noexcept
-{ return static_cast<unsigned>(__lhs) == static_cast<unsigned>(__rhs); }
-
-inline constexpr
-bool operator!=(const weekday& __lhs, const weekday& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-bool operator< (const weekday& __lhs, const weekday& __rhs) noexcept
-{ return static_cast<unsigned>(__lhs) <  static_cast<unsigned>(__rhs); }
-
-inline constexpr
-bool operator> (const weekday& __lhs, const weekday& __rhs) noexcept
-{ return __rhs < __lhs; }
-
-inline constexpr
-bool operator<=(const weekday& __lhs, const weekday& __rhs) noexcept
-{ return !(__rhs < __lhs);}
-
-inline constexpr
-bool operator>=(const weekday& __lhs, const weekday& __rhs) noexcept
-{ return !(__lhs < __rhs); }
-
-constexpr weekday operator+(const weekday& __lhs, const days& __rhs) noexcept
-{
-    auto const __mu = static_cast<long long>(static_cast<unsigned>(__lhs)) + __rhs.count();
-    auto const __yr = (__mu >= 0 ? __mu : __mu - 6) / 7;
-    return weekday{static_cast<unsigned>(__mu - __yr * 7)};
-}
-
-constexpr weekday operator+(const days& __lhs, const weekday& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-constexpr weekday operator-(const weekday& __lhs, const days& __rhs) noexcept
-{ return __lhs + -__rhs; }
-
-constexpr days operator-(const weekday& __lhs, const weekday& __rhs) noexcept
-{
-    const int __wdu = static_cast<unsigned>(__lhs) - static_cast<unsigned>(__rhs);
-    const int __wk = (__wdu >= 0 ? __wdu : __wdu-6) / 7;
-    return days{__wdu - __wk * 7};
-}
-
-inline constexpr weekday& weekday::operator+=(const days& __dd) noexcept
-{ *this = *this + __dd; return *this; }
-
-inline constexpr weekday& weekday::operator-=(const days& __dd) noexcept
-{ *this = *this - __dd; return *this; }
-
-
-class _LIBCPP_TYPE_VIS weekday_indexed {
-private:
-    _VSTD::chrono::weekday __wd;
-    unsigned char          __idx;
-public:
-    weekday_indexed() = default;
-    inline constexpr weekday_indexed(const _VSTD::chrono::weekday& __wdval, unsigned __idxval) noexcept
-        : __wd{__wdval}, __idx(__idxval) {}
-    inline constexpr _VSTD::chrono::weekday weekday() const noexcept { return __wd; }
-    inline constexpr unsigned                 index() const noexcept { return __idx; }
-    inline constexpr bool ok() const noexcept { return __wd.ok() && __idx >= 1 && __idx <= 5; }
-};
-
-inline constexpr
-bool operator==(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
-{ return __lhs.weekday() == __rhs.weekday() && __lhs.index() == __rhs.index(); }
-
-inline constexpr
-bool operator!=(const weekday_indexed& __lhs, const weekday_indexed& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-
-class _LIBCPP_TYPE_VIS weekday_last {
-private:
-    _VSTD::chrono::weekday __wd;
-public:
-    explicit constexpr weekday_last(const _VSTD::chrono::weekday& __val) noexcept
-        : __wd{__val} {}
-    constexpr _VSTD::chrono::weekday weekday() const noexcept { return __wd; }
-    constexpr bool ok() const noexcept { return __wd.ok(); }
-};
-
-inline constexpr
-bool operator==(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
-{ return __lhs.weekday() == __rhs.weekday(); }
-
-inline constexpr
-bool operator!=(const weekday_last& __lhs, const weekday_last& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-weekday_indexed weekday::operator[](unsigned __index) const noexcept { return weekday_indexed{*this, __index}; }
-
-inline constexpr 
-weekday_last    weekday::operator[](last_spec) const noexcept { return weekday_last{*this}; }
-
-
-inline constexpr last_spec last{};
-inline constexpr weekday   Sunday{0};
-inline constexpr weekday   Monday{1};
-inline constexpr weekday   Tuesday{2};
-inline constexpr weekday   Wednesday{3};
-inline constexpr weekday   Thursday{4};
-inline constexpr weekday   Friday{5};
-inline constexpr weekday   Saturday{6};
-
-inline constexpr month January{1};
-inline constexpr month February{2};
-inline constexpr month March{3};
-inline constexpr month April{4};
-inline constexpr month May{5};
-inline constexpr month June{6};
-inline constexpr month July{7};
-inline constexpr month August{8};
-inline constexpr month September{9};
-inline constexpr month October{10};
-inline constexpr month November{11};
-inline constexpr month December{12};
-
-
-class _LIBCPP_TYPE_VIS month_day {
-private:
-   chrono::month __m;
-   chrono::day   __d;
-public:
-    month_day() = default;
-    constexpr month_day(const chrono::month& __mval, const chrono::day& __dval) noexcept
-        : __m{__mval}, __d{__dval} {}
-    inline constexpr chrono::month month() const noexcept { return __m; }
-    inline constexpr chrono::day   day()   const noexcept { return __d; }
-    constexpr bool ok() const noexcept;
-};
-
-inline constexpr
-bool month_day::ok() const noexcept
-{
-    if (!__m.ok()) return false;
-    const unsigned __dval = static_cast<unsigned>(__d);
-    if (__dval < 1 || __dval > 31) return false;
-    if (__dval <= 29) return true;
-//  Now we've got either 30 or 31
-    const unsigned __mval = static_cast<unsigned>(__m);
-    if (__mval == 2) return false;
-    if (__mval == 4 || __mval == 6 || __mval == 9 || __mval == 11)
-        return __dval == 30;
-    return true;
-}
-
-inline constexpr
-bool operator==(const month_day& __lhs, const month_day& __rhs) noexcept
-{ return __lhs.month() == __rhs.month() && __lhs.day() == __rhs.day(); }
-
-inline constexpr
-bool operator!=(const month_day& __lhs, const month_day& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-month_day operator/(const month& __lhs, const day& __rhs) noexcept
-{ return month_day{__lhs, __rhs}; }
-
-constexpr
-month_day operator/(const day& __lhs, const month& __rhs) noexcept
-{ return __rhs / __lhs; }
-
-inline constexpr
-month_day operator/(const month& __lhs, int __rhs) noexcept
-{ return __lhs / day(__rhs); }
-
-constexpr
-month_day operator/(int __lhs, const day& __rhs) noexcept
-{ return month(__lhs) / __rhs; }
-
-constexpr
-month_day operator/(const day& __lhs, int __rhs) noexcept
-{ return month(__rhs) / __lhs; }
-
-
-inline constexpr
-bool operator< (const month_day& __lhs, const month_day& __rhs) noexcept
-{ return __lhs.month() != __rhs.month() ? __lhs.month() < __rhs.month() : __lhs.day() < __rhs.day(); }
-
-inline constexpr
-bool operator> (const month_day& __lhs, const month_day& __rhs) noexcept
-{ return __rhs < __lhs; }
-
-inline constexpr
-bool operator<=(const month_day& __lhs, const month_day& __rhs) noexcept
-{ return !(__rhs < __lhs);}
-
-inline constexpr
-bool operator>=(const month_day& __lhs, const month_day& __rhs) noexcept
-{ return !(__lhs < __rhs); }
-
-
-
-class _LIBCPP_TYPE_VIS month_day_last {
-private:
-    chrono::month __m;
-public:
-    explicit constexpr month_day_last(const chrono::month& __val) noexcept
-        : __m{__val} {}
-    inline constexpr chrono::month month() const noexcept { return __m; }
-    inline constexpr bool ok() const noexcept { return __m.ok(); }
-};
-
-inline constexpr
-bool operator==(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
-{ return __lhs.month() == __rhs.month(); }
-
-inline constexpr
-bool operator!=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-bool operator< (const month_day_last& __lhs, const month_day_last& __rhs) noexcept
-{ return __lhs.month() < __rhs.month(); }
-
-inline constexpr
-bool operator> (const month_day_last& __lhs, const month_day_last& __rhs) noexcept
-{ return __rhs < __lhs; }
-
-inline constexpr
-bool operator<=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
-{ return !(__rhs < __lhs);}
-
-inline constexpr
-bool operator>=(const month_day_last& __lhs, const month_day_last& __rhs) noexcept
-{ return !(__lhs < __rhs); }
-
-inline constexpr
-month_day_last operator/(const month& __lhs, last_spec) noexcept
-{ return month_day_last{__lhs}; }
-
-inline constexpr
-month_day_last operator/(last_spec, const month& __rhs) noexcept
-{ return month_day_last{__rhs}; }
-
-inline constexpr
-month_day_last operator/(int __lhs, last_spec) noexcept
-{ return month_day_last{month(__lhs)}; }
-
-inline constexpr
-month_day_last operator/(last_spec, int __rhs) noexcept
-{ return month_day_last{month(__rhs)}; }
-
-
-class _LIBCPP_TYPE_VIS month_weekday {
-private:
-    chrono::month __m;
-    chrono::weekday_indexed __wdi;
-public:
-    month_weekday() = default;
-    constexpr month_weekday(const chrono::month& __mval, const chrono::weekday_indexed& __wdival) noexcept
-        : __m{__mval}, __wdi{__wdival} {}
-    inline constexpr chrono::month                     month() const noexcept { return __m; }
-    inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
-    inline constexpr bool                                 ok() const noexcept { return __m.ok() && __wdi.ok(); }
-};
-
-inline constexpr
-bool operator==(const month_weekday& __lhs, const month_weekday& __rhs) noexcept
-{ return __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
-
-inline constexpr
-bool operator!=(const month_weekday& __lhs, const month_weekday& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-month_weekday operator/(const month& __lhs, const weekday_indexed& __rhs) noexcept
-{ return month_weekday{__lhs, __rhs}; }
-
-inline constexpr
-month_weekday operator/(int __lhs, const weekday_indexed& __rhs) noexcept
-{ return month_weekday{month(__lhs), __rhs}; }
-
-inline constexpr
-month_weekday operator/(const weekday_indexed& __lhs, const month& __rhs) noexcept
-{ return month_weekday{__rhs, __lhs}; }
-
-inline constexpr
-month_weekday operator/(const weekday_indexed& __lhs, int __rhs) noexcept
-{ return month_weekday{month(__rhs), __lhs}; }
-
-
-class _LIBCPP_TYPE_VIS month_weekday_last {
-    chrono::month        __m;
-    chrono::weekday_last __wdl;
-  public:
-    constexpr month_weekday_last(const chrono::month& __mval, const chrono::weekday_last& __wdlval) noexcept
-        : __m{__mval}, __wdl{__wdlval} {}
-    inline constexpr chrono::month               month() const noexcept { return __m; }
-    inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
-    inline constexpr bool                           ok() const noexcept { return __m.ok() && __wdl.ok(); }
-};
-
-inline constexpr
-bool operator==(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept
-{ return __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
-
-inline constexpr
-bool operator!=(const month_weekday_last& __lhs, const month_weekday_last& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-
-inline constexpr
-month_weekday_last operator/(const month& __lhs, const weekday_last& __rhs) noexcept
-{ return month_weekday_last{__lhs, __rhs}; }
-
-inline constexpr
-month_weekday_last operator/(int __lhs, const weekday_last& __rhs) noexcept
-{ return month_weekday_last{month(__lhs), __rhs}; }
-
-inline constexpr
-month_weekday_last operator/(const weekday_last& __lhs, const month& __rhs) noexcept
-{ return month_weekday_last{__rhs, __lhs}; }
-
-inline constexpr
-month_weekday_last operator/(const weekday_last& __lhs, int __rhs) noexcept
-{ return month_weekday_last{month(__rhs), __lhs}; }
-
-
-class _LIBCPP_TYPE_VIS year_month {
-    chrono::year  __y;
-    chrono::month __m;
-public:
-    year_month() = default;
-    constexpr year_month(const chrono::year& __yval, const chrono::month& __mval) noexcept
-        : __y{__yval}, __m{__mval} {}
-    inline constexpr chrono::year  year()  const noexcept { return __y; }
-    inline constexpr chrono::month month() const noexcept { return __m; }
-    inline constexpr year_month& operator+=(const months& __dm) noexcept { this->__m += __dm; return *this; }
-    inline constexpr year_month& operator-=(const months& __dm) noexcept { this->__m -= __dm; return *this; }
-    inline constexpr year_month& operator+=(const years& __dy)  noexcept { this->__y += __dy; return *this; }
-    inline constexpr year_month& operator-=(const years& __dy)  noexcept { this->__y -= __dy; return *this; }
-    inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok(); }
-};
-
-inline constexpr
-year_month operator/(const year& __y, const month& __m) noexcept { return year_month{__y, __m}; }
-
-inline constexpr
-year_month operator/(const year& __y, int __m) noexcept { return year_month{__y, month(__m)}; }
-
-inline constexpr
-bool operator==(const year_month& __lhs, const year_month& __rhs) noexcept
-{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month(); }
-
-inline constexpr
-bool operator!=(const year_month& __lhs, const year_month& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-bool operator< (const year_month& __lhs, const year_month& __rhs) noexcept
-{ return __lhs.year() != __rhs.year() ? __lhs.year() < __rhs.year() : __lhs.month() < __rhs.month(); }
-
-inline constexpr
-bool operator> (const year_month& __lhs, const year_month& __rhs) noexcept
-{ return __rhs < __lhs; }
-
-inline constexpr
-bool operator<=(const year_month& __lhs, const year_month& __rhs) noexcept
-{ return !(__rhs < __lhs);}
-
-inline constexpr
-bool operator>=(const year_month& __lhs, const year_month& __rhs) noexcept
-{ return !(__lhs < __rhs); }
-
-constexpr year_month operator+(const year_month& __lhs, const months& __rhs) noexcept
-{
-    int __dmi = static_cast<int>(static_cast<unsigned>(__lhs.month())) - 1 + __rhs.count();
-    const int __dy = (__dmi >= 0 ? __dmi : __dmi-11) / 12;
-    __dmi = __dmi - __dy * 12 + 1;
-    return (__lhs.year() + years(__dy)) / month(static_cast<unsigned>(__dmi));
-}
-
-constexpr year_month operator+(const months& __lhs, const year_month& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-constexpr year_month operator+(const year_month& __lhs, const years& __rhs) noexcept
-{ return (__lhs.year() + __rhs) / __lhs.month(); }
-
-constexpr year_month operator+(const years& __lhs, const year_month& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-constexpr months     operator-(const year_month& __lhs, const year_month& __rhs) noexcept
-{ return (__lhs.year() - __rhs.year()) + months(static_cast<unsigned>(__lhs.month()) - static_cast<unsigned>(__rhs.month())); }
-
-constexpr year_month operator-(const year_month& __lhs, const months& __rhs) noexcept
-{ return __lhs + -__rhs; }
-
-constexpr year_month operator-(const year_month& __lhs, const years& __rhs) noexcept
-{ return __lhs + -__rhs; }
-
-class year_month_day_last;
-
-class _LIBCPP_TYPE_VIS year_month_day {
-private:
-    chrono::year  __y;
-    chrono::month __m;
-    chrono::day   __d;
-public:
-     year_month_day() = default;
-     inline constexpr year_month_day(
-            const chrono::year& __yval, const chrono::month& __mval, const chrono::day& __dval) noexcept
-            : __y{__yval}, __m{__mval}, __d{__dval} {}  
-            constexpr year_month_day(const year_month_day_last& __ymdl) noexcept;
-     inline constexpr year_month_day(const sys_days& __sysd) noexcept
-            : year_month_day(__from_days(__sysd.time_since_epoch())) {}
-     inline explicit constexpr year_month_day(const local_days& __locd) noexcept
-            : year_month_day(__from_days(__locd.time_since_epoch())) {}
-
-            constexpr year_month_day& operator+=(const months& __dm) noexcept;
-            constexpr year_month_day& operator-=(const months& __dm) noexcept;
-            constexpr year_month_day& operator+=(const years& __dy)  noexcept;
-            constexpr year_month_day& operator-=(const years& __dy)  noexcept;
-
-     inline constexpr chrono::year   year() const noexcept { return __y; }
-     inline constexpr chrono::month month() const noexcept { return __m; }
-     inline constexpr chrono::day     day() const noexcept { return __d; }
-     inline constexpr operator   sys_days() const noexcept          { return   sys_days{__to_days()}; }
-     inline explicit constexpr operator local_days() const noexcept { return local_days{__to_days()}; }
-
-            constexpr bool             ok() const noexcept;
-
-     static constexpr year_month_day __from_days(days __d) noexcept;
-     constexpr days __to_days() const noexcept;
-};
-
-
-// https://howardhinnant.github.io/date_algorithms.html#civil_from_days
-inline constexpr
-year_month_day
-year_month_day::__from_days(days __d) noexcept
-{
-    static_assert(std::numeric_limits<unsigned>::digits >= 18, "");
-    static_assert(std::numeric_limits<int>::digits >= 20     , "");
-    const int      __z = __d.count() + 719468;
-    const int      __era = (__z >= 0 ? __z : __z - 146096) / 146097;
-    const unsigned __doe = static_cast<unsigned>(__z - __era * 146097);              // [0, 146096]
-    const unsigned __yoe = (__doe - __doe/1460 + __doe/36524 - __doe/146096) / 365;  // [0, 399]
-    const int      __yr = static_cast<int>(__yoe) + __era * 400;
-    const unsigned __doy = __doe - (365 * __yoe + __yoe/4 - __yoe/100);              // [0, 365]
-    const unsigned __mp = (5 * __doy + 2)/153;                                       // [0, 11]
-    const unsigned __dy = __doy - (153 * __mp + 2)/5 + 1;                            // [1, 31]
-    const unsigned __mth = __mp + (__mp < 10 ? 3 : -9);                              // [1, 12]
-    return year_month_day{chrono::year{__yr + (__mth <= 2)}, chrono::month{__mth}, chrono::day{__dy}};
-}
-
-// https://howardhinnant.github.io/date_algorithms.html#days_from_civil
-inline constexpr days year_month_day::__to_days() const noexcept
-{
-    static_assert(std::numeric_limits<unsigned>::digits >= 18, "");
-    static_assert(std::numeric_limits<int>::digits >= 20     , "");
-
-    const int      __yr  = static_cast<int>(__y) - (__m <= February);
-    const unsigned __mth = static_cast<unsigned>(__m);
-    const unsigned __dy  = static_cast<unsigned>(__d);
-
-    const int      __era = (__yr >= 0 ? __yr : __yr - 399) / 400;
-    const unsigned __yoe = static_cast<unsigned>(__yr - __era * 400);                // [0, 399]
-    const unsigned __doy = (153 * (__mth + (__mth > 2 ? -3 : 9)) + 2) / 5 + __dy-1;  // [0, 365]
-    const unsigned __doe = __yoe * 365 + __yoe/4 - __yoe/100 + __doy;                // [0, 146096]
-    return days{__era * 146097 + static_cast<int>(__doe) - 719468};
-}
-
-inline constexpr
-bool operator==(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
-{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.day() == __rhs.day(); }
-
-inline constexpr
-bool operator!=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-bool operator< (const year_month_day& __lhs, const year_month_day& __rhs) noexcept
-{
-    if (__lhs.year() < __rhs.year()) return true;
-    if (__lhs.year() > __rhs.year()) return false;
-    if (__lhs.month() < __rhs.month()) return true;
-    if (__lhs.month() > __rhs.month()) return false;
-    return __lhs.day() < __rhs.day();
-}
-
-inline constexpr
-bool operator> (const year_month_day& __lhs, const year_month_day& __rhs) noexcept
-{ return __rhs < __lhs; }
-
-inline constexpr
-bool operator<=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
-{ return !(__rhs < __lhs);}
-
-inline constexpr
-bool operator>=(const year_month_day& __lhs, const year_month_day& __rhs) noexcept
-{ return !(__lhs < __rhs); }
-
-inline constexpr
-year_month_day operator/(const year_month& __lhs, const day& __rhs) noexcept
-{ return year_month_day{__lhs.year(), __lhs.month(), __rhs}; }
-
-inline constexpr
-year_month_day operator/(const year_month& __lhs, int __rhs) noexcept
-{ return __lhs / day(__rhs); }
-
-inline constexpr
-year_month_day operator/(const year& __lhs, const month_day& __rhs) noexcept
-{ return __lhs / __rhs.month() / __rhs.day(); }
-
-inline constexpr
-year_month_day operator/(int __lhs, const month_day& __rhs) noexcept
-{ return year(__lhs) / __rhs; }
-
-inline constexpr
-year_month_day operator/(const month_day& __lhs, const year& __rhs) noexcept
-{ return __rhs / __lhs; }
-
-inline constexpr
-year_month_day operator/(const month_day& __lhs, int __rhs) noexcept
-{ return year(__rhs) / __lhs; }
-
-
-inline constexpr
-year_month_day operator+(const year_month_day& __lhs, const months& __rhs) noexcept
-{ return (__lhs.year()/__lhs.month() + __rhs)/__lhs.day(); }
-
-inline constexpr
-year_month_day operator+(const months& __lhs, const year_month_day& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-year_month_day operator-(const year_month_day& __lhs, const months& __rhs) noexcept
-{ return __lhs + -__rhs; }
-
-inline constexpr
-year_month_day operator+(const year_month_day& __lhs, const years& __rhs) noexcept
-{ return (__lhs.year() + __rhs) / __lhs.month() / __lhs.day(); }
-
-inline constexpr
-year_month_day operator+(const years& __lhs, const year_month_day& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-year_month_day operator-(const year_month_day& __lhs, const years& __rhs) noexcept
-{ return __lhs + -__rhs; }
-
-inline constexpr year_month_day& year_month_day::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
-inline constexpr year_month_day& year_month_day::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
-inline constexpr year_month_day& year_month_day::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
-inline constexpr year_month_day& year_month_day::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
-
-class _LIBCPP_TYPE_VIS year_month_day_last {
-private:
-    chrono::year           __y;
-    chrono::month_day_last __mdl;
-public:
-     constexpr year_month_day_last(const year& __yval, const month_day_last& __mdlval) noexcept
-        : __y{__yval}, __mdl{__mdlval} {}
-
-     constexpr year_month_day_last& operator+=(const months& __m) noexcept;
-     constexpr year_month_day_last& operator-=(const months& __m) noexcept;
-     constexpr year_month_day_last& operator+=(const years& __y)  noexcept;
-     constexpr year_month_day_last& operator-=(const years& __y)  noexcept;
-
-     inline constexpr chrono::year                     year() const noexcept { return __y; }
-     inline constexpr chrono::month                   month() const noexcept { return __mdl.month(); }
-     inline constexpr chrono::month_day_last month_day_last() const noexcept { return __mdl; }
-            constexpr chrono::day                       day() const noexcept;
-     inline constexpr operator                     sys_days() const noexcept { return   sys_days{year()/month()/day()}; }
-     inline explicit constexpr operator          local_days() const noexcept { return local_days{year()/month()/day()}; }
-     inline constexpr bool                               ok() const noexcept { return __y.ok() && __mdl.ok(); }
-};
-
-inline constexpr
-chrono::day year_month_day_last::day() const noexcept
-{
-    constexpr chrono::day __d[] =
-    {
-        chrono::day(31), chrono::day(28), chrono::day(31),
-        chrono::day(30), chrono::day(31), chrono::day(30),
-        chrono::day(31), chrono::day(31), chrono::day(30),
-        chrono::day(31), chrono::day(30), chrono::day(31)
-    };
-    return month() != February || !__y.is_leap() ?
-        __d[static_cast<unsigned>(month()) - 1] : chrono::day{29};
-}
-
-inline constexpr
-bool operator==(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
-{ return __lhs.year() == __rhs.year() && __lhs.month_day_last() == __rhs.month_day_last(); }
-
-inline constexpr
-bool operator!=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-bool operator< (const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
-{
-    if (__lhs.year() < __rhs.year()) return true;
-    if (__lhs.year() > __rhs.year()) return false;
-    return __lhs.month_day_last() < __rhs.month_day_last();
-}
-
-inline constexpr
-bool operator> (const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
-{ return __rhs < __lhs; }
-
-inline constexpr
-bool operator<=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
-{ return !(__rhs < __lhs);}
-
-inline constexpr
-bool operator>=(const year_month_day_last& __lhs, const year_month_day_last& __rhs) noexcept
-{ return !(__lhs < __rhs); }
-
-inline constexpr year_month_day_last operator/(const year_month& __lhs, last_spec) noexcept
-{ return year_month_day_last{__lhs.year(), month_day_last{__lhs.month()}}; }
-
-inline constexpr year_month_day_last operator/(const year& __lhs, const month_day_last& __rhs) noexcept
-{ return year_month_day_last{__lhs, __rhs}; }
-
-inline constexpr year_month_day_last operator/(int __lhs, const month_day_last& __rhs) noexcept
-{ return year_month_day_last{year{__lhs}, __rhs}; }
-
-inline constexpr year_month_day_last operator/(const month_day_last& __lhs, const year& __rhs) noexcept
-{ return __rhs / __lhs; }
-
-inline constexpr year_month_day_last operator/(const month_day_last& __lhs, int __rhs) noexcept
-{ return year{__rhs} / __lhs; }
-
-
-inline constexpr
-year_month_day_last operator+(const year_month_day_last& __lhs, const months& __rhs) noexcept
-{ return (__lhs.year() / __lhs.month() + __rhs) / last; }
-
-inline constexpr
-year_month_day_last operator+(const months& __lhs, const year_month_day_last& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-year_month_day_last operator-(const year_month_day_last& __lhs, const months& __rhs) noexcept
-{ return __lhs + (-__rhs); }
-
-inline constexpr
-year_month_day_last operator+(const year_month_day_last& __lhs, const years& __rhs) noexcept
-{ return year_month_day_last{__lhs.year() + __rhs, __lhs.month_day_last()}; }
-
-inline constexpr
-year_month_day_last operator+(const years& __lhs, const year_month_day_last& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-year_month_day_last operator-(const year_month_day_last& __lhs, const years& __rhs) noexcept
-{ return __lhs + (-__rhs); }
-
-inline constexpr year_month_day_last& year_month_day_last::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
-inline constexpr year_month_day_last& year_month_day_last::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
-inline constexpr year_month_day_last& year_month_day_last::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
-inline constexpr year_month_day_last& year_month_day_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
-
-inline constexpr year_month_day::year_month_day(const year_month_day_last& __ymdl) noexcept
-    : __y{__ymdl.year()}, __m{__ymdl.month()}, __d{__ymdl.day()} {}  
-
-inline constexpr bool year_month_day::ok() const noexcept
-{
-    if (!__y.ok() || !__m.ok()) return false;
-    return chrono::day{1} <= __d && __d <= (__y / __m / last).day();
-}
-
-class _LIBCPP_TYPE_VIS year_month_weekday {
-    chrono::year            __y;
-    chrono::month           __m;
-    chrono::weekday_indexed __wdi;
-public:
-    year_month_weekday() = default;
-    constexpr year_month_weekday(const chrono::year& __yval, const chrono::month& __mval,
-                               const chrono::weekday_indexed& __wdival) noexcept
-        : __y{__yval}, __m{__mval}, __wdi{__wdival} {}
-    constexpr year_month_weekday(const sys_days& __sysd) noexcept
-            : year_month_weekday(__from_days(__sysd.time_since_epoch())) {}
-    inline explicit constexpr year_month_weekday(const local_days& __locd) noexcept
-            : year_month_weekday(__from_days(__locd.time_since_epoch())) {}
-    constexpr year_month_weekday& operator+=(const months& m) noexcept;
-    constexpr year_month_weekday& operator-=(const months& m) noexcept;
-    constexpr year_month_weekday& operator+=(const years& y)  noexcept;
-    constexpr year_month_weekday& operator-=(const years& y)  noexcept;
-
-    inline constexpr chrono::year                       year() const noexcept { return __y; }
-    inline constexpr chrono::month                     month() const noexcept { return __m; }
-    inline constexpr chrono::weekday                 weekday() const noexcept { return __wdi.weekday(); }
-    inline constexpr unsigned                          index() const noexcept { return __wdi.index(); }
-    inline constexpr chrono::weekday_indexed weekday_indexed() const noexcept { return __wdi; }
-
-    inline constexpr                       operator sys_days() const noexcept { return   sys_days{__to_days()}; }
-    inline explicit constexpr operator            local_days() const noexcept { return local_days{__to_days()}; }
-    inline constexpr bool ok() const noexcept
-    {
-        if (!__y.ok() || !__m.ok() || !__wdi.ok()) return false;
-    //  TODO: make sure it's a valid date
-        return true;
-    }
-
-    static constexpr year_month_weekday __from_days(days __d) noexcept;
-    constexpr days __to_days() const noexcept;
-};
-
-inline constexpr
-year_month_weekday year_month_weekday::__from_days(days __d) noexcept
-{
-    const sys_days      __sysd{__d};
-    const chrono::weekday __wd = chrono::weekday(__sysd);
-    const year_month_day __ymd = year_month_day(__sysd);
-    return year_month_weekday{__ymd.year(), __ymd.month(), 
-                              __wd[(static_cast<unsigned>(__ymd.day())-1)/7+1]};
-}
-
-inline constexpr
-days year_month_weekday::__to_days() const noexcept
-{
-    const sys_days __sysd = sys_days(__y/__m/1);
-    return (__sysd + (__wdi.weekday() - chrono::weekday(__sysd) + days{(__wdi.index()-1)*7}))
-                .time_since_epoch();
-}
-
-inline constexpr
-bool operator==(const year_month_weekday& __lhs, const year_month_weekday& __rhs) noexcept
-{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_indexed() == __rhs.weekday_indexed(); }
-
-inline constexpr
-bool operator!=(const year_month_weekday& __lhs, const year_month_weekday& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-inline constexpr
-year_month_weekday operator/(const year_month& __lhs, const weekday_indexed& __rhs) noexcept
-{ return year_month_weekday{__lhs.year(), __lhs.month(), __rhs}; }
-
-inline constexpr
-year_month_weekday operator/(const year& __lhs, const month_weekday& __rhs) noexcept
-{ return year_month_weekday{__lhs, __rhs.month(), __rhs.weekday_indexed()}; }
-
-inline constexpr
-year_month_weekday operator/(int __lhs, const month_weekday& __rhs) noexcept
-{ return year(__lhs) / __rhs; }
-
-inline constexpr
-year_month_weekday operator/(const month_weekday& __lhs, const year& __rhs) noexcept
-{ return __rhs / __lhs; }
-
-inline constexpr
-year_month_weekday operator/(const month_weekday& __lhs, int __rhs) noexcept
-{ return year(__rhs) / __lhs; }
-
-
-inline constexpr
-year_month_weekday operator+(const year_month_weekday& __lhs, const months& __rhs) noexcept
-{ return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_indexed(); }
-
-inline constexpr
-year_month_weekday operator+(const months& __lhs, const year_month_weekday& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-year_month_weekday operator-(const year_month_weekday& __lhs, const months& __rhs) noexcept
-{ return __lhs + (-__rhs); }
-
-inline constexpr
-year_month_weekday operator+(const year_month_weekday& __lhs, const years& __rhs) noexcept
-{ return year_month_weekday{__lhs.year() + __rhs, __lhs.month(), __lhs.weekday_indexed()}; }
-
-inline constexpr
-year_month_weekday operator+(const years& __lhs, const year_month_weekday& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-year_month_weekday operator-(const year_month_weekday& __lhs, const years& __rhs) noexcept
-{ return __lhs + (-__rhs); }
-
-
-inline constexpr year_month_weekday& year_month_weekday::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
-inline constexpr year_month_weekday& year_month_weekday::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
-inline constexpr year_month_weekday& year_month_weekday::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
-inline constexpr year_month_weekday& year_month_weekday::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
-
-class _LIBCPP_TYPE_VIS year_month_weekday_last {
-private:
-    chrono::year         __y;
-    chrono::month        __m;
-    chrono::weekday_last __wdl;
-public:
-    constexpr year_month_weekday_last(const chrono::year& __yval, const chrono::month& __mval,
-                                      const chrono::weekday_last& __wdlval) noexcept
-                : __y{__yval}, __m{__mval}, __wdl{__wdlval} {}
-    constexpr year_month_weekday_last& operator+=(const months& __dm) noexcept;
-    constexpr year_month_weekday_last& operator-=(const months& __dm) noexcept;
-    constexpr year_month_weekday_last& operator+=(const years& __dy)  noexcept;
-    constexpr year_month_weekday_last& operator-=(const years& __dy)  noexcept;
-
-    inline constexpr chrono::year                 year() const noexcept { return __y; }
-    inline constexpr chrono::month               month() const noexcept { return __m; }
-    inline constexpr chrono::weekday           weekday() const noexcept { return __wdl.weekday(); }
-    inline constexpr chrono::weekday_last weekday_last() const noexcept { return __wdl; }
-    inline constexpr operator                 sys_days() const noexcept { return   sys_days{__to_days()}; }
-    inline explicit constexpr operator      local_days() const noexcept { return local_days{__to_days()}; }
-    inline constexpr bool ok() const noexcept { return __y.ok() && __m.ok() && __wdl.ok(); }
-    
-    constexpr days __to_days() const noexcept;
-    
-};
-
-inline constexpr
-days year_month_weekday_last::__to_days() const noexcept
-{
-    const sys_days __last = sys_days{__y/__m/last};
-    return (__last - (chrono::weekday{__last} - __wdl.weekday())).time_since_epoch();
-
-}
-
-inline constexpr
-bool operator==(const year_month_weekday_last& __lhs, const year_month_weekday_last& __rhs) noexcept
-{ return __lhs.year() == __rhs.year() && __lhs.month() == __rhs.month() && __lhs.weekday_last() == __rhs.weekday_last(); }
-
-inline constexpr
-bool operator!=(const year_month_weekday_last& __lhs, const year_month_weekday_last& __rhs) noexcept
-{ return !(__lhs == __rhs); }
-
-
-inline constexpr
-year_month_weekday_last operator/(const year_month& __lhs, const weekday_last& __rhs) noexcept
-{ return year_month_weekday_last{__lhs.year(), __lhs.month(), __rhs}; }
-
-inline constexpr
-year_month_weekday_last operator/(const year& __lhs, const month_weekday_last& __rhs) noexcept
-{ return year_month_weekday_last{__lhs, __rhs.month(), __rhs.weekday_last()}; }
-
-inline constexpr
-year_month_weekday_last operator/(int __lhs, const month_weekday_last& __rhs) noexcept
-{ return year(__lhs) / __rhs; }
-
-inline constexpr
-year_month_weekday_last operator/(const month_weekday_last& __lhs, const year& __rhs) noexcept
-{ return __rhs / __lhs; }
-
-inline constexpr
-year_month_weekday_last operator/(const month_weekday_last& __lhs, int __rhs) noexcept
-{ return year(__rhs) / __lhs; }  
-
-
-inline constexpr
-year_month_weekday_last operator+(const year_month_weekday_last& __lhs, const months& __rhs) noexcept
-{ return (__lhs.year() / __lhs.month() + __rhs) / __lhs.weekday_last(); }
-
-inline constexpr
-year_month_weekday_last operator+(const months& __lhs, const year_month_weekday_last& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-year_month_weekday_last operator-(const year_month_weekday_last& __lhs, const months& __rhs) noexcept
-{ return __lhs + (-__rhs); }
-
-inline constexpr
-year_month_weekday_last operator+(const year_month_weekday_last& __lhs, const years& __rhs) noexcept
-{ return year_month_weekday_last{__lhs.year() + __rhs, __lhs.month(), __lhs.weekday_last()}; }
-
-inline constexpr
-year_month_weekday_last operator+(const years& __lhs, const year_month_weekday_last& __rhs) noexcept
-{ return __rhs + __lhs; }
-
-inline constexpr
-year_month_weekday_last operator-(const year_month_weekday_last& __lhs, const years& __rhs) noexcept
-{ return __lhs + (-__rhs); }
-
-inline constexpr year_month_weekday_last& year_month_weekday_last::operator+=(const months& __dm) noexcept { *this = *this + __dm; return *this; }
-inline constexpr year_month_weekday_last& year_month_weekday_last::operator-=(const months& __dm) noexcept { *this = *this - __dm; return *this; }
-inline constexpr year_month_weekday_last& year_month_weekday_last::operator+=(const years& __dy)  noexcept { *this = *this + __dy; return *this; }
-inline constexpr year_month_weekday_last& year_month_weekday_last::operator-=(const years& __dy)  noexcept { *this = *this - __dy; return *this; }
-
-#endif // _LIBCPP_STD_VER > 17
-} // chrono
-
-#if _LIBCPP_STD_VER > 11
-// Suffixes for duration literals [time.duration.literals]
-inline namespace literals
-{
-  inline namespace chrono_literals
-  {
-
-    constexpr chrono::hours operator""h(unsigned long long __h)
-    {
-        return chrono::hours(static_cast<chrono::hours::rep>(__h));
-    }
-
-    constexpr chrono::duration<long double, ratio<3600,1>> operator""h(long double __h)
-    {
-        return chrono::duration<long double, ratio<3600,1>>(__h);
-    }
-
-
-    constexpr chrono::minutes operator""min(unsigned long long __m)
-    {
-        return chrono::minutes(static_cast<chrono::minutes::rep>(__m));
-    }
-
-    constexpr chrono::duration<long double, ratio<60,1>> operator""min(long double __m)
-    {
-        return chrono::duration<long double, ratio<60,1>> (__m);
-    }
-
-
-    constexpr chrono::seconds operator""s(unsigned long long __s)
-    {
-        return chrono::seconds(static_cast<chrono::seconds::rep>(__s));
-    }
-
-    constexpr chrono::duration<long double> operator""s(long double __s)
-    {
-        return chrono::duration<long double> (__s);
-    }
-
-
-    constexpr chrono::milliseconds operator""ms(unsigned long long __ms)
-    {
-        return chrono::milliseconds(static_cast<chrono::milliseconds::rep>(__ms));
-    }
-
-    constexpr chrono::duration<long double, milli> operator""ms(long double __ms)
-    {
-        return chrono::duration<long double, milli>(__ms);
-    }
-
-
-    constexpr chrono::microseconds operator""us(unsigned long long __us)
-    {
-        return chrono::microseconds(static_cast<chrono::microseconds::rep>(__us));
-    }
-
-    constexpr chrono::duration<long double, micro> operator""us(long double __us)
-    {
-        return chrono::duration<long double, micro> (__us);
-    }
-
-
-    constexpr chrono::nanoseconds operator""ns(unsigned long long __ns)
-    {
-        return chrono::nanoseconds(static_cast<chrono::nanoseconds::rep>(__ns));
-    }
-
-    constexpr chrono::duration<long double, nano> operator""ns(long double __ns)
-    {
-        return chrono::duration<long double, nano> (__ns);
-    }
-
-#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CXX20_CHRONO_LITERALS)
-    constexpr chrono::day operator ""d(unsigned long long __d) noexcept
-    {
-        return chrono::day(static_cast<unsigned>(__d));
-    }
- 
-    constexpr chrono::year operator ""y(unsigned long long __y) noexcept
-    {
-        return chrono::year(static_cast<int>(__y));
-    }
-#endif
-}}
-
-namespace chrono { // hoist the literals into namespace std::chrono
-   using namespace literals::chrono_literals;
-}
-
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#ifndef _LIBCPP_CXX03_LANG
-_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
-struct _FilesystemClock {
-#if !defined(_LIBCPP_HAS_NO_INT128)
-  typedef __int128_t rep;
-  typedef nano period;
-#else
-  typedef long long rep;
-  typedef nano period;
-#endif
-
-  typedef chrono::duration<rep, period> duration;
-  typedef chrono::time_point<_FilesystemClock> time_point;
-
-  static _LIBCPP_CONSTEXPR_AFTER_CXX11 const bool is_steady = false;
-
-  _LIBCPP_FUNC_VIS static time_point now() noexcept;
-
-  _LIBCPP_INLINE_VISIBILITY
-  static time_t to_time_t(const time_point& __t) noexcept {
-      typedef chrono::duration<rep> __secs;
-      return time_t(
-          chrono::duration_cast<__secs>(__t.time_since_epoch()).count());
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  static time_point from_time_t(time_t __t) noexcept {
-      typedef chrono::duration<rep> __secs;
-      return time_point(__secs(__t));
-  }
-};
-_LIBCPP_END_NAMESPACE_FILESYSTEM
-#endif // !_LIBCPP_CXX03_LANG
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_CHRONO
diff --git a/lib/libcxx/include/cinttypes b/lib/libcxx/include/cinttypes
deleted file mode 100644
index 3f61b0634b1..00000000000
--- a/lib/libcxx/include/cinttypes
+++ /dev/null
@@ -1,258 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cinttypes --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CINTTYPES
-#define _LIBCPP_CINTTYPES
-
-/*
-    cinttypes synopsis
-
-This entire header is C99 / C++0X
-
-#include <cstdint>  // <cinttypes> includes <cstdint>
-
-Macros:
-
-    PRId8
-    PRId16
-    PRId32
-    PRId64
-
-    PRIdLEAST8
-    PRIdLEAST16
-    PRIdLEAST32
-    PRIdLEAST64
-
-    PRIdFAST8
-    PRIdFAST16
-    PRIdFAST32
-    PRIdFAST64
-
-    PRIdMAX
-    PRIdPTR
-
-    PRIi8
-    PRIi16
-    PRIi32
-    PRIi64
-
-    PRIiLEAST8
-    PRIiLEAST16
-    PRIiLEAST32
-    PRIiLEAST64
-
-    PRIiFAST8
-    PRIiFAST16
-    PRIiFAST32
-    PRIiFAST64
-
-    PRIiMAX
-    PRIiPTR
-
-    PRIo8
-    PRIo16
-    PRIo32
-    PRIo64
-
-    PRIoLEAST8
-    PRIoLEAST16
-    PRIoLEAST32
-    PRIoLEAST64
-
-    PRIoFAST8
-    PRIoFAST16
-    PRIoFAST32
-    PRIoFAST64
-
-    PRIoMAX
-    PRIoPTR
-
-    PRIu8
-    PRIu16
-    PRIu32
-    PRIu64
-
-    PRIuLEAST8
-    PRIuLEAST16
-    PRIuLEAST32
-    PRIuLEAST64
-
-    PRIuFAST8
-    PRIuFAST16
-    PRIuFAST32
-    PRIuFAST64
-
-    PRIuMAX
-    PRIuPTR
-
-    PRIx8
-    PRIx16
-    PRIx32
-    PRIx64
-
-    PRIxLEAST8
-    PRIxLEAST16
-    PRIxLEAST32
-    PRIxLEAST64
-
-    PRIxFAST8
-    PRIxFAST16
-    PRIxFAST32
-    PRIxFAST64
-
-    PRIxMAX
-    PRIxPTR
-
-    PRIX8
-    PRIX16
-    PRIX32
-    PRIX64
-
-    PRIXLEAST8
-    PRIXLEAST16
-    PRIXLEAST32
-    PRIXLEAST64
-
-    PRIXFAST8
-    PRIXFAST16
-    PRIXFAST32
-    PRIXFAST64
-
-    PRIXMAX
-    PRIXPTR
-
-    SCNd8
-    SCNd16
-    SCNd32
-    SCNd64
-
-    SCNdLEAST8
-    SCNdLEAST16
-    SCNdLEAST32
-    SCNdLEAST64
-
-    SCNdFAST8
-    SCNdFAST16
-    SCNdFAST32
-    SCNdFAST64
-
-    SCNdMAX
-    SCNdPTR
-
-    SCNi8
-    SCNi16
-    SCNi32
-    SCNi64
-
-    SCNiLEAST8
-    SCNiLEAST16
-    SCNiLEAST32
-    SCNiLEAST64
-
-    SCNiFAST8
-    SCNiFAST16
-    SCNiFAST32
-    SCNiFAST64
-
-    SCNiMAX
-    SCNiPTR
-
-    SCNo8
-    SCNo16
-    SCNo32
-    SCNo64
-
-    SCNoLEAST8
-    SCNoLEAST16
-    SCNoLEAST32
-    SCNoLEAST64
-
-    SCNoFAST8
-    SCNoFAST16
-    SCNoFAST32
-    SCNoFAST64
-
-    SCNoMAX
-    SCNoPTR
-
-    SCNu8
-    SCNu16
-    SCNu32
-    SCNu64
-
-    SCNuLEAST8
-    SCNuLEAST16
-    SCNuLEAST32
-    SCNuLEAST64
-
-    SCNuFAST8
-    SCNuFAST16
-    SCNuFAST32
-    SCNuFAST64
-
-    SCNuMAX
-    SCNuPTR
-
-    SCNx8
-    SCNx16
-    SCNx32
-    SCNx64
-
-    SCNxLEAST8
-    SCNxLEAST16
-    SCNxLEAST32
-    SCNxLEAST64
-
-    SCNxFAST8
-    SCNxFAST16
-    SCNxFAST32
-    SCNxFAST64
-
-    SCNxMAX
-    SCNxPTR
-
-namespace std
-{
-
-Types:
-
-    imaxdiv_t
-
-intmax_t  imaxabs(intmax_t j);
-imaxdiv_t imaxdiv(intmax_t numer, intmax_t denom);
-intmax_t  strtoimax(const char* restrict nptr, char** restrict endptr, int base);
-uintmax_t strtoumax(const char* restrict nptr, char** restrict endptr, int base);
-intmax_t  wcstoimax(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
-uintmax_t wcstoumax(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
-
-}  // std
-*/
-
-#include <__config>
-#include <cstdint>
-#include <inttypes.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using::imaxdiv_t;
-using::imaxabs;
-using::imaxdiv;
-using::strtoimax;
-using::strtoumax;
-using::wcstoimax;
-using::wcstoumax;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CINTTYPES
diff --git a/lib/libcxx/include/ciso646 b/lib/libcxx/include/ciso646
deleted file mode 100644
index b2efc72a9aa..00000000000
--- a/lib/libcxx/include/ciso646
+++ /dev/null
@@ -1,25 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- ciso646 ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CISO646
-#define _LIBCPP_CISO646
-
-/*
-    ciso646 synopsis
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#endif  // _LIBCPP_CISO646
diff --git a/lib/libcxx/include/climits b/lib/libcxx/include/climits
deleted file mode 100644
index 81ffecdf6ee..00000000000
--- a/lib/libcxx/include/climits
+++ /dev/null
@@ -1,48 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- climits ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CLIMITS
-#define _LIBCPP_CLIMITS
-
-/*
-    climits synopsis
-
-Macros:
-
-    CHAR_BIT
-    SCHAR_MIN
-    SCHAR_MAX
-    UCHAR_MAX
-    CHAR_MIN
-    CHAR_MAX
-    MB_LEN_MAX
-    SHRT_MIN
-    SHRT_MAX
-    USHRT_MAX
-    INT_MIN
-    INT_MAX
-    UINT_MAX
-    LONG_MIN
-    LONG_MAX
-    ULONG_MAX
-    LLONG_MIN   // C99
-    LLONG_MAX   // C99
-    ULLONG_MAX  // C99
-
-*/
-
-#include <__config>
-#include <limits.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#endif  // _LIBCPP_CLIMITS
diff --git a/lib/libcxx/include/clocale b/lib/libcxx/include/clocale
deleted file mode 100644
index 05fa9c6edda..00000000000
--- a/lib/libcxx/include/clocale
+++ /dev/null
@@ -1,55 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- clocale ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CLOCALE
-#define _LIBCPP_CLOCALE
-
-/*
-    clocale synopsis
-
-Macros:
-
-    LC_ALL
-    LC_COLLATE
-    LC_CTYPE
-    LC_MONETARY
-    LC_NUMERIC
-    LC_TIME
-    NULL
-
-namespace std
-{
-
-struct lconv;
-char* setlocale(int category, const char* locale);
-lconv* localeconv();
-
-}  // std
-
-*/
-
-#include <__config>
-#include <locale.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::lconv;
-#ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
-using ::setlocale;
-#endif
-using ::localeconv;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CLOCALE
diff --git a/lib/libcxx/include/cmath b/lib/libcxx/include/cmath
deleted file mode 100644
index f5f62adcfb8..00000000000
--- a/lib/libcxx/include/cmath
+++ /dev/null
@@ -1,612 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- cmath -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CMATH
-#define _LIBCPP_CMATH
-
-/*
-    cmath synopsis
-
-Macros:
-
-    HUGE_VAL
-    HUGE_VALF               // C99
-    HUGE_VALL               // C99
-    INFINITY                // C99
-    NAN                     // C99
-    FP_INFINITE             // C99
-    FP_NAN                  // C99
-    FP_NORMAL               // C99
-    FP_SUBNORMAL            // C99
-    FP_ZERO                 // C99
-    FP_FAST_FMA             // C99
-    FP_FAST_FMAF            // C99
-    FP_FAST_FMAL            // C99
-    FP_ILOGB0               // C99
-    FP_ILOGBNAN             // C99
-    MATH_ERRNO              // C99
-    MATH_ERREXCEPT          // C99
-    math_errhandling        // C99
-
-namespace std
-{
-
-Types:
-
-    float_t                 // C99
-    double_t                // C99
-
-// C90
-
-floating_point abs(floating_point x);
-
-floating_point acos (arithmetic x);
-float          acosf(float x);
-long double    acosl(long double x);
-
-floating_point asin (arithmetic x);
-float          asinf(float x);
-long double    asinl(long double x);
-
-floating_point atan (arithmetic x);
-float          atanf(float x);
-long double    atanl(long double x);
-
-floating_point atan2 (arithmetic y, arithmetic x);
-float          atan2f(float y, float x);
-long double    atan2l(long double y, long double x);
-
-floating_point ceil (arithmetic x);
-float          ceilf(float x);
-long double    ceill(long double x);
-
-floating_point cos (arithmetic x);
-float          cosf(float x);
-long double    cosl(long double x);
-
-floating_point cosh (arithmetic x);
-float          coshf(float x);
-long double    coshl(long double x);
-
-floating_point exp (arithmetic x);
-float          expf(float x);
-long double    expl(long double x);
-
-floating_point fabs (arithmetic x);
-float          fabsf(float x);
-long double    fabsl(long double x);
-
-floating_point floor (arithmetic x);
-float          floorf(float x);
-long double    floorl(long double x);
-
-floating_point fmod (arithmetic x, arithmetic y);
-float          fmodf(float x, float y);
-long double    fmodl(long double x, long double y);
-
-floating_point frexp (arithmetic value, int* exp);
-float          frexpf(float value, int* exp);
-long double    frexpl(long double value, int* exp);
-
-floating_point ldexp (arithmetic value, int exp);
-float          ldexpf(float value, int exp);
-long double    ldexpl(long double value, int exp);
-
-floating_point log (arithmetic x);
-float          logf(float x);
-long double    logl(long double x);
-
-floating_point log10 (arithmetic x);
-float          log10f(float x);
-long double    log10l(long double x);
-
-floating_point modf (floating_point value, floating_point* iptr);
-float          modff(float value, float* iptr);
-long double    modfl(long double value, long double* iptr);
-
-floating_point pow (arithmetic x, arithmetic y);
-float          powf(float x, float y);
-long double    powl(long double x, long double y);
-
-floating_point sin (arithmetic x);
-float          sinf(float x);
-long double    sinl(long double x);
-
-floating_point sinh (arithmetic x);
-float          sinhf(float x);
-long double    sinhl(long double x);
-
-floating_point sqrt (arithmetic x);
-float          sqrtf(float x);
-long double    sqrtl(long double x);
-
-floating_point tan (arithmetic x);
-float          tanf(float x);
-long double    tanl(long double x);
-
-floating_point tanh (arithmetic x);
-float          tanhf(float x);
-long double    tanhl(long double x);
-
-//  C99
-
-bool signbit(arithmetic x);
-
-int fpclassify(arithmetic x);
-
-bool isfinite(arithmetic x);
-bool isinf(arithmetic x);
-bool isnan(arithmetic x);
-bool isnormal(arithmetic x);
-
-bool isgreater(arithmetic x, arithmetic y);
-bool isgreaterequal(arithmetic x, arithmetic y);
-bool isless(arithmetic x, arithmetic y);
-bool islessequal(arithmetic x, arithmetic y);
-bool islessgreater(arithmetic x, arithmetic y);
-bool isunordered(arithmetic x, arithmetic y);
-
-floating_point acosh (arithmetic x);
-float          acoshf(float x);
-long double    acoshl(long double x);
-
-floating_point asinh (arithmetic x);
-float          asinhf(float x);
-long double    asinhl(long double x);
-
-floating_point atanh (arithmetic x);
-float          atanhf(float x);
-long double    atanhl(long double x);
-
-floating_point cbrt (arithmetic x);
-float          cbrtf(float x);
-long double    cbrtl(long double x);
-
-floating_point copysign (arithmetic x, arithmetic y);
-float          copysignf(float x, float y);
-long double    copysignl(long double x, long double y);
-
-floating_point erf (arithmetic x);
-float          erff(float x);
-long double    erfl(long double x);
-
-floating_point erfc (arithmetic x);
-float          erfcf(float x);
-long double    erfcl(long double x);
-
-floating_point exp2 (arithmetic x);
-float          exp2f(float x);
-long double    exp2l(long double x);
-
-floating_point expm1 (arithmetic x);
-float          expm1f(float x);
-long double    expm1l(long double x);
-
-floating_point fdim (arithmetic x, arithmetic y);
-float          fdimf(float x, float y);
-long double    fdiml(long double x, long double y);
-
-floating_point fma (arithmetic x, arithmetic y, arithmetic z);
-float          fmaf(float x, float y, float z);
-long double    fmal(long double x, long double y, long double z);
-
-floating_point fmax (arithmetic x, arithmetic y);
-float          fmaxf(float x, float y);
-long double    fmaxl(long double x, long double y);
-
-floating_point fmin (arithmetic x, arithmetic y);
-float          fminf(float x, float y);
-long double    fminl(long double x, long double y);
-
-floating_point hypot (arithmetic x, arithmetic y);
-float          hypotf(float x, float y);
-long double    hypotl(long double x, long double y);
-
-double       hypot(double x, double y, double z);                // C++17
-float        hypot(float x, float y, float z);                   // C++17
-long double  hypot(long double x, long double y, long double z); // C++17
-
-int ilogb (arithmetic x);
-int ilogbf(float x);
-int ilogbl(long double x);
-
-floating_point lgamma (arithmetic x);
-float          lgammaf(float x);
-long double    lgammal(long double x);
-
-long long llrint (arithmetic x);
-long long llrintf(float x);
-long long llrintl(long double x);
-
-long long llround (arithmetic x);
-long long llroundf(float x);
-long long llroundl(long double x);
-
-floating_point log1p (arithmetic x);
-float          log1pf(float x);
-long double    log1pl(long double x);
-
-floating_point log2 (arithmetic x);
-float          log2f(float x);
-long double    log2l(long double x);
-
-floating_point logb (arithmetic x);
-float          logbf(float x);
-long double    logbl(long double x);
-
-long lrint (arithmetic x);
-long lrintf(float x);
-long lrintl(long double x);
-
-long lround (arithmetic x);
-long lroundf(float x);
-long lroundl(long double x);
-
-double      nan (const char* str);
-float       nanf(const char* str);
-long double nanl(const char* str);
-
-floating_point nearbyint (arithmetic x);
-float          nearbyintf(float x);
-long double    nearbyintl(long double x);
-
-floating_point nextafter (arithmetic x, arithmetic y);
-float          nextafterf(float x, float y);
-long double    nextafterl(long double x, long double y);
-
-floating_point nexttoward (arithmetic x, long double y);
-float          nexttowardf(float x, long double y);
-long double    nexttowardl(long double x, long double y);
-
-floating_point remainder (arithmetic x, arithmetic y);
-float          remainderf(float x, float y);
-long double    remainderl(long double x, long double y);
-
-floating_point remquo (arithmetic x, arithmetic y, int* pquo);
-float          remquof(float x, float y, int* pquo);
-long double    remquol(long double x, long double y, int* pquo);
-
-floating_point rint (arithmetic x);
-float          rintf(float x);
-long double    rintl(long double x);
-
-floating_point round (arithmetic x);
-float          roundf(float x);
-long double    roundl(long double x);
-
-floating_point scalbln (arithmetic x, long ex);
-float          scalblnf(float x, long ex);
-long double    scalblnl(long double x, long ex);
-
-floating_point scalbn (arithmetic x, int ex);
-float          scalbnf(float x, int ex);
-long double    scalbnl(long double x, int ex);
-
-floating_point tgamma (arithmetic x);
-float          tgammaf(float x);
-long double    tgammal(long double x);
-
-floating_point trunc (arithmetic x);
-float          truncf(float x);
-long double    truncl(long double x);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <math.h>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::signbit;
-using ::fpclassify;
-using ::isfinite;
-using ::isinf;
-using ::isnan;
-using ::isnormal;
-using ::isgreater;
-using ::isgreaterequal;
-using ::isless;
-using ::islessequal;
-using ::islessgreater;
-using ::isunordered;
-using ::isunordered;
-
-using ::float_t;
-using ::double_t;
-
-#ifndef _AIX
-using ::abs;
-#endif
-
-using ::acos;
-using ::acosf;
-using ::asin;
-using ::asinf;
-using ::atan;
-using ::atanf;
-using ::atan2;
-using ::atan2f;
-using ::ceil;
-using ::ceilf;
-using ::cos;
-using ::cosf;
-using ::cosh;
-using ::coshf;
-
-using ::exp;
-using ::expf;
-
-using ::fabs;
-using ::fabsf;
-using ::floor;
-using ::floorf;
-
-using ::fmod;
-using ::fmodf;
-
-using ::frexp;
-using ::frexpf;
-using ::ldexp;
-using ::ldexpf;
-
-using ::log;
-using ::logf;
-
-using ::log10;
-using ::log10f;
-using ::modf;
-using ::modff;
-
-using ::pow;
-using ::powf;
-
-using ::sin;
-using ::sinf;
-using ::sinh;
-using ::sinhf;
-
-using ::sqrt;
-using ::sqrtf;
-using ::tan;
-using ::tanf;
-
-using ::tanh;
-using ::tanhf;
-
-using ::acosh;
-using ::acoshf;
-using ::asinh;
-using ::asinhf;
-using ::atanh;
-using ::atanhf;
-using ::cbrt;
-using ::cbrtf;
-
-using ::copysign;
-using ::copysignf;
-
-using ::erf;
-using ::erff;
-using ::erfc;
-using ::erfcf;
-using ::exp2;
-using ::exp2f;
-using ::expm1;
-using ::expm1f;
-using ::fdim;
-using ::fdimf;
-using ::fmaf;
-using ::fma;
-using ::fmax;
-using ::fmaxf;
-using ::fmin;
-using ::fminf;
-using ::hypot;
-using ::hypotf;
-using ::ilogb;
-using ::ilogbf;
-using ::lgamma;
-using ::lgammaf;
-using ::llrint;
-using ::llrintf;
-using ::llround;
-using ::llroundf;
-using ::log1p;
-using ::log1pf;
-using ::log2;
-using ::log2f;
-using ::logb;
-using ::logbf;
-using ::lrint;
-using ::lrintf;
-using ::lround;
-using ::lroundf;
-
-using ::nan;
-using ::nanf;
-
-using ::nearbyint;
-using ::nearbyintf;
-using ::nextafter;
-using ::nextafterf;
-using ::nexttoward;
-using ::nexttowardf;
-using ::remainder;
-using ::remainderf;
-using ::remquo;
-using ::remquof;
-using ::rint;
-using ::rintf;
-using ::round;
-using ::roundf;
-using ::scalbln;
-using ::scalblnf;
-using ::scalbn;
-using ::scalbnf;
-using ::tgamma;
-using ::tgammaf;
-using ::trunc;
-using ::truncf;
-
-using ::acosl;
-using ::asinl;
-using ::atanl;
-using ::atan2l;
-using ::ceill;
-using ::cosl;
-using ::coshl;
-using ::expl;
-using ::fabsl;
-using ::floorl;
-using ::fmodl;
-using ::frexpl;
-using ::ldexpl;
-using ::logl;
-using ::log10l;
-using ::modfl;
-using ::powl;
-using ::sinl;
-using ::sinhl;
-using ::sqrtl;
-using ::tanl;
-
-using ::tanhl;
-using ::acoshl;
-using ::asinhl;
-using ::atanhl;
-using ::cbrtl;
-
-using ::copysignl;
-
-using ::erfl;
-using ::erfcl;
-using ::exp2l;
-using ::expm1l;
-using ::fdiml;
-using ::fmal;
-using ::fmaxl;
-using ::fminl;
-using ::hypotl;
-using ::ilogbl;
-using ::lgammal;
-using ::llrintl;
-using ::llroundl;
-using ::log1pl;
-using ::log2l;
-using ::logbl;
-using ::lrintl;
-using ::lroundl;
-using ::nanl;
-using ::nearbyintl;
-using ::nextafterl;
-using ::nexttowardl;
-using ::remainderl;
-using ::remquol;
-using ::rintl;
-using ::roundl;
-using ::scalblnl;
-using ::scalbnl;
-using ::tgammal;
-using ::truncl;
-
-#if _LIBCPP_STD_VER > 14
-inline _LIBCPP_INLINE_VISIBILITY float       hypot(       float x,       float y,       float z ) { return sqrt(x*x + y*y + z*z); }
-inline _LIBCPP_INLINE_VISIBILITY double      hypot(      double x,      double y,      double z ) { return sqrt(x*x + y*y + z*z); }
-inline _LIBCPP_INLINE_VISIBILITY long double hypot( long double x, long double y, long double z ) { return sqrt(x*x + y*y + z*z); }
-
-template <class _A1, class _A2, class _A3>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __lazy_enable_if
-<
-    is_arithmetic<_A1>::value &&
-    is_arithmetic<_A2>::value &&
-    is_arithmetic<_A3>::value,
-    __promote<_A1, _A2, _A3>
->::type
-hypot(_A1 __lcpp_x, _A2 __lcpp_y, _A3 __lcpp_z) _NOEXCEPT
-{
-    typedef typename __promote<_A1, _A2, _A3>::type __result_type;
-    static_assert((!(is_same<_A1, __result_type>::value &&
-                     is_same<_A2, __result_type>::value &&
-                     is_same<_A3, __result_type>::value)), "");
-    return hypot((__result_type)__lcpp_x, (__result_type)__lcpp_y, (__result_type)__lcpp_z);
-}
-#endif
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR typename enable_if<is_floating_point<_A1>::value, bool>::type
-__libcpp_isnan_or_builtin(_A1 __lcpp_x) _NOEXCEPT
-{
-#if __has_builtin(__builtin_isnan)
-    return __builtin_isnan(__lcpp_x);
-#else
-    return isnan(__lcpp_x);
-#endif
-}
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR typename enable_if<!is_floating_point<_A1>::value, bool>::type
-__libcpp_isnan_or_builtin(_A1 __lcpp_x) _NOEXCEPT
-{
-    return isnan(__lcpp_x);
-}
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR typename enable_if<is_floating_point<_A1>::value, bool>::type
-__libcpp_isinf_or_builtin(_A1 __lcpp_x) _NOEXCEPT
-{
-#if __has_builtin(__builtin_isinf)
-    return __builtin_isinf(__lcpp_x);
-#else
-    return isinf(__lcpp_x);
-#endif
-}
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR typename enable_if<!is_floating_point<_A1>::value, bool>::type
-__libcpp_isinf_or_builtin(_A1 __lcpp_x) _NOEXCEPT
-{
-    return isinf(__lcpp_x);
-}
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR typename enable_if<is_floating_point<_A1>::value, bool>::type
-__libcpp_isfinite_or_builtin(_A1 __lcpp_x) _NOEXCEPT
-{
-#if __has_builtin(__builtin_isfinite)
-    return __builtin_isfinite(__lcpp_x);
-#else
-    return isfinite(__lcpp_x);
-#endif
-}
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR typename enable_if<!is_floating_point<_A1>::value, bool>::type
-__libcpp_isfinite_or_builtin(_A1 __lcpp_x) _NOEXCEPT
-{
-    return isfinite(__lcpp_x);
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CMATH
diff --git a/lib/libcxx/include/codecvt b/lib/libcxx/include/codecvt
deleted file mode 100644
index 5eb9d154911..00000000000
--- a/lib/libcxx/include/codecvt
+++ /dev/null
@@ -1,550 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- codecvt -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CODECVT
-#define _LIBCPP_CODECVT
-
-/*
-    codecvt synopsis
-
-namespace std
-{
-
-enum codecvt_mode
-{
-    consume_header = 4,
-    generate_header = 2,
-    little_endian = 1
-};
-
-template <class Elem, unsigned long Maxcode = 0x10ffff,
-          codecvt_mode Mode = (codecvt_mode)0>
-class codecvt_utf8
-    : public codecvt<Elem, char, mbstate_t>
-{
-    explicit codecvt_utf8(size_t refs = 0);
-    ~codecvt_utf8();
-};
-
-template <class Elem, unsigned long Maxcode = 0x10ffff,
-          codecvt_mode Mode = (codecvt_mode)0>
-class codecvt_utf16
-    : public codecvt<Elem, char, mbstate_t>
-{
-    explicit codecvt_utf16(size_t refs = 0);
-    ~codecvt_utf16();
-};
-
-template <class Elem, unsigned long Maxcode = 0x10ffff,
-          codecvt_mode Mode = (codecvt_mode)0>
-class codecvt_utf8_utf16
-    : public codecvt<Elem, char, mbstate_t>
-{
-    explicit codecvt_utf8_utf16(size_t refs = 0);
-    ~codecvt_utf8_utf16();
-};
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__locale>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-enum codecvt_mode
-{
-    consume_header = 4,
-    generate_header = 2,
-    little_endian = 1
-};
-
-// codecvt_utf8
-
-template <class _Elem> class __codecvt_utf8;
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf8<wchar_t>
-    : public codecvt<wchar_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef wchar_t   intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf8(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf8<char16_t>
-    : public codecvt<char16_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef char16_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf8(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf8<char32_t>
-    : public codecvt<char32_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef char32_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf8(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <class _Elem, unsigned long _Maxcode = 0x10ffff,
-          codecvt_mode _Mode = (codecvt_mode)0>
-class _LIBCPP_TEMPLATE_VIS codecvt_utf8
-    : public __codecvt_utf8<_Elem>
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt_utf8(size_t __refs = 0)
-        : __codecvt_utf8<_Elem>(__refs, _Maxcode, _Mode) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~codecvt_utf8() {}
-};
-
-// codecvt_utf16
-
-template <class _Elem, bool _LittleEndian> class __codecvt_utf16;
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf16<wchar_t, false>
-    : public codecvt<wchar_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef wchar_t   intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf16<wchar_t, true>
-    : public codecvt<wchar_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef wchar_t   intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf16<char16_t, false>
-    : public codecvt<char16_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef char16_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf16<char16_t, true>
-    : public codecvt<char16_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef char16_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf16<char32_t, false>
-    : public codecvt<char32_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef char32_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf16<char32_t, true>
-    : public codecvt<char32_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef char32_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf16(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <class _Elem, unsigned long _Maxcode = 0x10ffff,
-          codecvt_mode _Mode = (codecvt_mode)0>
-class _LIBCPP_TEMPLATE_VIS codecvt_utf16
-    : public __codecvt_utf16<_Elem, _Mode & little_endian>
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt_utf16(size_t __refs = 0)
-        : __codecvt_utf16<_Elem, _Mode & little_endian>(__refs, _Maxcode, _Mode) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~codecvt_utf16() {}
-};
-
-// codecvt_utf8_utf16
-
-template <class _Elem> class __codecvt_utf8_utf16;
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf8_utf16<wchar_t>
-    : public codecvt<wchar_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef wchar_t   intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf8_utf16(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<wchar_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf8_utf16<char32_t>
-    : public codecvt<char32_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef char32_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf8_utf16(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<char32_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <>
-class _LIBCPP_TYPE_VIS __codecvt_utf8_utf16<char16_t>
-    : public codecvt<char16_t, char, mbstate_t>
-{
-    unsigned long _Maxcode_;
-    codecvt_mode _Mode_;
-public:
-    typedef char16_t  intern_type;
-    typedef char      extern_type;
-    typedef mbstate_t state_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __codecvt_utf8_utf16(size_t __refs, unsigned long _Maxcode,
-                            codecvt_mode _Mode)
-        : codecvt<char16_t, char, mbstate_t>(__refs), _Maxcode_(_Maxcode),
-          _Mode_(_Mode) {}
-protected:
-    virtual result
-        do_out(state_type& __st,
-               const intern_type* __frm, const intern_type* __frm_end, const intern_type*& __frm_nxt,
-               extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual result
-        do_in(state_type& __st,
-              const extern_type* __frm, const extern_type* __frm_end, const extern_type*& __frm_nxt,
-              intern_type* __to, intern_type* __to_end, intern_type*& __to_nxt) const;
-    virtual result
-        do_unshift(state_type& __st,
-                   extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
-    virtual int do_encoding() const throw();
-    virtual bool do_always_noconv() const throw();
-    virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end,
-                          size_t __mx) const;
-    virtual int do_max_length() const throw();
-};
-
-template <class _Elem, unsigned long _Maxcode = 0x10ffff,
-          codecvt_mode _Mode = (codecvt_mode)0>
-class _LIBCPP_TEMPLATE_VIS codecvt_utf8_utf16
-    : public __codecvt_utf8_utf16<_Elem>
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit codecvt_utf8_utf16(size_t __refs = 0)
-        : __codecvt_utf8_utf16<_Elem>(__refs, _Maxcode, _Mode) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~codecvt_utf8_utf16() {}
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CODECVT
diff --git a/lib/libcxx/include/compare b/lib/libcxx/include/compare
deleted file mode 100644
index 07f88f09cb3..00000000000
--- a/lib/libcxx/include/compare
+++ /dev/null
@@ -1,679 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- compare -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_COMPARE
-#define _LIBCPP_COMPARE
-
-/*
-    compare synopsis
-
-namespace std {
-  // [cmp.categories], comparison category types
-  class weak_equality;
-  class strong_equality;
-  class partial_ordering;
-  class weak_ordering;
-  class strong_ordering;
-
-  // named comparison functions
-  constexpr bool is_eq  (weak_equality cmp) noexcept    { return cmp == 0; }
-  constexpr bool is_neq (weak_equality cmp) noexcept    { return cmp != 0; }
-  constexpr bool is_lt  (partial_ordering cmp) noexcept { return cmp < 0; }
-  constexpr bool is_lteq(partial_ordering cmp) noexcept { return cmp <= 0; }
-  constexpr bool is_gt  (partial_ordering cmp) noexcept { return cmp > 0; }
-  constexpr bool is_gteq(partial_ordering cmp) noexcept { return cmp >= 0; }
-
-  // [cmp.common], common comparison category type
-  template<class... Ts>
-  struct common_comparison_category {
-    using type = see below;
-  };
-  template<class... Ts>
-    using common_comparison_category_t = typename common_comparison_category<Ts...>::type;
-
-  // [cmp.alg], comparison algorithms
-  template<class T> constexpr strong_ordering strong_order(const T& a, const T& b);
-  template<class T> constexpr weak_ordering weak_order(const T& a, const T& b);
-  template<class T> constexpr partial_ordering partial_order(const T& a, const T& b);
-  template<class T> constexpr strong_equality strong_equal(const T& a, const T& b);
-  template<class T> constexpr weak_equality weak_equal(const T& a, const T& b);
-}
-*/
-
-#include <__config>
-#include <type_traits>
-#include <array>
-
-#ifndef _LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER > 17
-
-// exposition only
-enum class _LIBCPP_ENUM_VIS _EqResult : unsigned char {
-  __zero = 0,
-  __equal = __zero,
-  __equiv = __equal,
-  __nonequal = 1,
-  __nonequiv = __nonequal
-};
-
-enum class _LIBCPP_ENUM_VIS _OrdResult : signed char {
-  __less = -1,
-  __greater = 1
-};
-
-enum class _LIBCPP_ENUM_VIS _NCmpResult : signed char {
-  __unordered = -127
-};
-
-struct _CmpUnspecifiedType;
-using _CmpUnspecifiedParam = void (_CmpUnspecifiedType::*)();
-
-class  weak_equality {
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr explicit weak_equality(_EqResult __val) noexcept : __value_(__val) {}
-
-public:
-  static const weak_equality equivalent;
-  static const weak_equality nonequivalent;
-
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(weak_equality __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(_CmpUnspecifiedParam, weak_equality __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(weak_equality __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(_CmpUnspecifiedParam, weak_equality __v) noexcept;
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-  _LIBCPP_INLINE_VISIBILITY friend constexpr weak_equality operator<=>(weak_equality __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr weak_equality operator<=>(_CmpUnspecifiedParam, weak_equality __v) noexcept;
-#endif
-
-private:
-  _EqResult __value_;
-};
-
-_LIBCPP_INLINE_VAR constexpr weak_equality weak_equality::equivalent(_EqResult::__equiv);
-_LIBCPP_INLINE_VAR constexpr weak_equality weak_equality::nonequivalent(_EqResult::__nonequiv);
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr bool operator==(weak_equality __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ == _EqResult::__zero;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr bool operator==(_CmpUnspecifiedParam, weak_equality __v) noexcept {
-  return __v.__value_ == _EqResult::__zero;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr bool operator!=(weak_equality __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ != _EqResult::__zero;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr bool operator!=(_CmpUnspecifiedParam, weak_equality __v) noexcept {
-  return __v.__value_ != _EqResult::__zero;
-}
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr weak_equality operator<=>(weak_equality __v, _CmpUnspecifiedParam) noexcept {
-  return __v;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr weak_equality operator<=>(_CmpUnspecifiedParam, weak_equality __v) noexcept {
-  return __v;
-}
-#endif
-
-class strong_equality {
-  _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr strong_equality(_EqResult __val) noexcept : __value_(__val) {}
-
-public:
-  static const strong_equality equal;
-  static const strong_equality nonequal;
-  static const strong_equality equivalent;
-  static const strong_equality nonequivalent;
-
-  // conversion
-  _LIBCPP_INLINE_VISIBILITY constexpr operator weak_equality() const noexcept {
-    return __value_ == _EqResult::__zero ? weak_equality::equivalent
-          : weak_equality::nonequivalent;
-  }
-
-  // comparisons
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(strong_equality __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(strong_equality __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(_CmpUnspecifiedParam, strong_equality __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(_CmpUnspecifiedParam, strong_equality __v) noexcept;
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-  _LIBCPP_INLINE_VISIBILITY friend constexpr strong_equality operator<=>(strong_equality __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr strong_equality operator<=>(_CmpUnspecifiedParam, strong_equality __v) noexcept;
-#endif
-private:
-  _EqResult __value_;
-};
-
-_LIBCPP_INLINE_VAR constexpr strong_equality strong_equality::equal(_EqResult::__equal);
-_LIBCPP_INLINE_VAR constexpr strong_equality strong_equality::nonequal(_EqResult::__nonequal);
-_LIBCPP_INLINE_VAR constexpr strong_equality strong_equality::equivalent(_EqResult::__equiv);
-_LIBCPP_INLINE_VAR constexpr strong_equality strong_equality::nonequivalent(_EqResult::__nonequiv);
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(strong_equality __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ == _EqResult::__zero;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(_CmpUnspecifiedParam, strong_equality __v) noexcept {
-  return __v.__value_ == _EqResult::__zero;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(strong_equality __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ != _EqResult::__zero;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(_CmpUnspecifiedParam, strong_equality __v) noexcept {
-  return __v.__value_ != _EqResult::__zero;
-}
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-_LIBCPP_INLINE_VISIBILITY
-constexpr strong_equality operator<=>(strong_equality __v, _CmpUnspecifiedParam) noexcept {
-  return __v;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr strong_equality operator<=>(_CmpUnspecifiedParam, strong_equality __v) noexcept {
-  return __v;
-}
-#endif // _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-
-class partial_ordering {
-  using _ValueT = signed char;
-
-  _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr partial_ordering(_EqResult __v) noexcept
-      : __value_(_ValueT(__v)) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr partial_ordering(_OrdResult __v) noexcept
-      : __value_(_ValueT(__v)) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr partial_ordering(_NCmpResult __v) noexcept
-      : __value_(_ValueT(__v)) {}
-
-  constexpr bool __is_ordered() const noexcept {
-    return __value_ != _ValueT(_NCmpResult::__unordered);
-  }
-public:
-  // valid values
-  static const partial_ordering less;
-  static const partial_ordering equivalent;
-  static const partial_ordering greater;
-  static const partial_ordering unordered;
-
-  // conversion
-  constexpr operator weak_equality() const noexcept {
-    return __value_ == 0 ? weak_equality::equivalent : weak_equality::nonequivalent;
-  }
-
-  // comparisons
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(partial_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(partial_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator< (partial_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator<=(partial_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator> (partial_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator>=(partial_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(_CmpUnspecifiedParam, partial_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(_CmpUnspecifiedParam, partial_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator< (_CmpUnspecifiedParam, partial_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator<=(_CmpUnspecifiedParam, partial_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator> (_CmpUnspecifiedParam, partial_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator>=(_CmpUnspecifiedParam, partial_ordering __v) noexcept;
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-  _LIBCPP_INLINE_VISIBILITY friend constexpr partial_ordering operator<=>(partial_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr partial_ordering operator<=>(_CmpUnspecifiedParam, partial_ordering __v) noexcept;
-#endif
-
-private:
-  _ValueT __value_;
-};
-
-_LIBCPP_INLINE_VAR constexpr partial_ordering partial_ordering::less(_OrdResult::__less);
-_LIBCPP_INLINE_VAR constexpr partial_ordering partial_ordering::equivalent(_EqResult::__equiv);
-_LIBCPP_INLINE_VAR constexpr partial_ordering partial_ordering::greater(_OrdResult::__greater);
-_LIBCPP_INLINE_VAR constexpr partial_ordering partial_ordering::unordered(_NCmpResult ::__unordered);
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(partial_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__is_ordered() && __v.__value_ == 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator< (partial_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__is_ordered() && __v.__value_ < 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<=(partial_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__is_ordered() && __v.__value_ <= 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator> (partial_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__is_ordered() && __v.__value_ > 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>=(partial_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__is_ordered() && __v.__value_ >= 0;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(_CmpUnspecifiedParam, partial_ordering __v) noexcept {
-  return __v.__is_ordered() && 0 == __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator< (_CmpUnspecifiedParam, partial_ordering __v) noexcept {
-  return __v.__is_ordered() && 0 < __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<=(_CmpUnspecifiedParam, partial_ordering __v) noexcept {
-  return __v.__is_ordered() && 0 <= __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator> (_CmpUnspecifiedParam, partial_ordering __v) noexcept {
-  return __v.__is_ordered() && 0 > __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>=(_CmpUnspecifiedParam, partial_ordering __v) noexcept {
-  return __v.__is_ordered() && 0 >= __v.__value_;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(partial_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return !__v.__is_ordered() || __v.__value_ != 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(_CmpUnspecifiedParam, partial_ordering __v) noexcept {
-  return !__v.__is_ordered() || __v.__value_ != 0;
-}
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-_LIBCPP_INLINE_VISIBILITY
-constexpr partial_ordering operator<=>(partial_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr partial_ordering operator<=>(_CmpUnspecifiedParam, partial_ordering __v) noexcept {
-  return __v < 0 ? partial_ordering::greater : (__v > 0 ? partial_ordering::less : __v);
-}
-#endif // _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-
-class weak_ordering {
-  using _ValueT = signed char;
-
-  _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr weak_ordering(_EqResult __v) noexcept : __value_(_ValueT(__v)) {}
-  _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr weak_ordering(_OrdResult __v) noexcept : __value_(_ValueT(__v)) {}
-
-public:
-  static const weak_ordering less;
-  static const weak_ordering equivalent;
-  static const weak_ordering greater;
-
-  // conversions
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr operator weak_equality() const noexcept {
-    return __value_ == 0 ? weak_equality::equivalent
-                         : weak_equality::nonequivalent;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr operator partial_ordering() const noexcept {
-    return __value_ == 0 ? partial_ordering::equivalent
-        : (__value_ < 0 ? partial_ordering::less : partial_ordering::greater);
-  }
-
-  // comparisons
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(weak_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(weak_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator< (weak_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator<=(weak_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator> (weak_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator>=(weak_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(_CmpUnspecifiedParam, weak_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(_CmpUnspecifiedParam, weak_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator< (_CmpUnspecifiedParam, weak_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator<=(_CmpUnspecifiedParam, weak_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator> (_CmpUnspecifiedParam, weak_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator>=(_CmpUnspecifiedParam, weak_ordering __v) noexcept;
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-  _LIBCPP_INLINE_VISIBILITY friend constexpr weak_ordering operator<=>(weak_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr weak_ordering operator<=>(_CmpUnspecifiedParam, weak_ordering __v) noexcept;
-#endif
-
-private:
-  _ValueT __value_;
-};
-
-_LIBCPP_INLINE_VAR constexpr weak_ordering weak_ordering::less(_OrdResult::__less);
-_LIBCPP_INLINE_VAR constexpr weak_ordering weak_ordering::equivalent(_EqResult::__equiv);
-_LIBCPP_INLINE_VAR constexpr weak_ordering weak_ordering::greater(_OrdResult::__greater);
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(weak_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ == 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(weak_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ != 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator< (weak_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ < 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<=(weak_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ <= 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator> (weak_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ > 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>=(weak_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ >= 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(_CmpUnspecifiedParam, weak_ordering __v) noexcept {
-  return 0 == __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(_CmpUnspecifiedParam, weak_ordering __v) noexcept {
-  return 0 != __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator< (_CmpUnspecifiedParam, weak_ordering __v) noexcept {
-  return 0 < __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<=(_CmpUnspecifiedParam, weak_ordering __v) noexcept {
-  return 0 <= __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator> (_CmpUnspecifiedParam, weak_ordering __v) noexcept {
-  return 0 > __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>=(_CmpUnspecifiedParam, weak_ordering __v) noexcept {
-  return 0 >= __v.__value_;
-}
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-_LIBCPP_INLINE_VISIBILITY
-constexpr weak_ordering operator<=>(weak_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr weak_ordering operator<=>(_CmpUnspecifiedParam, weak_ordering __v) noexcept {
-  return __v < 0 ? weak_ordering::greater : (__v > 0 ? weak_ordering::less : __v);
-}
-#endif // _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-
-class strong_ordering {
-  using _ValueT = signed char;
-
-  _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr strong_ordering(_EqResult __v) noexcept : __value_(_ValueT(__v)) {}
-  _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr strong_ordering(_OrdResult __v) noexcept : __value_(_ValueT(__v)) {}
-
-public:
-  static const strong_ordering less;
-  static const strong_ordering equal;
-  static const strong_ordering equivalent;
-  static const strong_ordering greater;
-
-  // conversions
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr operator weak_equality() const noexcept {
-    return __value_ == 0 ? weak_equality::equivalent
-                         : weak_equality::nonequivalent;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr operator strong_equality() const noexcept {
-    return __value_ == 0 ? strong_equality::equal
-                         : strong_equality::nonequal;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr operator partial_ordering() const noexcept {
-    return __value_ == 0 ? partial_ordering::equivalent
-        : (__value_ < 0 ? partial_ordering::less : partial_ordering::greater);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr operator weak_ordering() const noexcept {
-    return __value_ == 0 ? weak_ordering::equivalent
-        : (__value_ < 0 ? weak_ordering::less : weak_ordering::greater);
-  }
-
-  // comparisons
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(strong_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(strong_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator< (strong_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator<=(strong_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator> (strong_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator>=(strong_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator==(_CmpUnspecifiedParam, strong_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator!=(_CmpUnspecifiedParam, strong_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator< (_CmpUnspecifiedParam, strong_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator<=(_CmpUnspecifiedParam, strong_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator> (_CmpUnspecifiedParam, strong_ordering __v) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr bool operator>=(_CmpUnspecifiedParam, strong_ordering __v) noexcept;
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-  _LIBCPP_INLINE_VISIBILITY friend constexpr strong_ordering operator<=>(strong_ordering __v, _CmpUnspecifiedParam) noexcept;
-  _LIBCPP_INLINE_VISIBILITY friend constexpr strong_ordering operator<=>(_CmpUnspecifiedParam, strong_ordering __v) noexcept;
-#endif
-
-private:
-  _ValueT __value_;
-};
-
-_LIBCPP_INLINE_VAR constexpr strong_ordering strong_ordering::less(_OrdResult::__less);
-_LIBCPP_INLINE_VAR constexpr strong_ordering strong_ordering::equal(_EqResult::__equal);
-_LIBCPP_INLINE_VAR constexpr strong_ordering strong_ordering::equivalent(_EqResult::__equiv);
-_LIBCPP_INLINE_VAR constexpr strong_ordering strong_ordering::greater(_OrdResult::__greater);
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(strong_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ == 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(strong_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ != 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator< (strong_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ < 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<=(strong_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ <= 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator> (strong_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ > 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>=(strong_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v.__value_ >= 0;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(_CmpUnspecifiedParam, strong_ordering __v) noexcept {
-  return 0 == __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(_CmpUnspecifiedParam, strong_ordering __v) noexcept {
-  return 0 != __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator< (_CmpUnspecifiedParam, strong_ordering __v) noexcept {
-  return 0 < __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<=(_CmpUnspecifiedParam, strong_ordering __v) noexcept {
-  return 0 <= __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator> (_CmpUnspecifiedParam, strong_ordering __v) noexcept {
-  return 0 > __v.__value_;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>=(_CmpUnspecifiedParam, strong_ordering __v) noexcept {
-  return 0 >= __v.__value_;
-}
-
-#ifndef _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-_LIBCPP_INLINE_VISIBILITY
-constexpr strong_ordering operator<=>(strong_ordering __v, _CmpUnspecifiedParam) noexcept {
-  return __v;
-}
-_LIBCPP_INLINE_VISIBILITY
-constexpr strong_ordering operator<=>(_CmpUnspecifiedParam, strong_ordering __v) noexcept {
-  return __v < 0 ? strong_ordering::greater : (__v > 0 ? strong_ordering::less : __v);
-}
-#endif // _LIBCPP_HAS_NO_SPACESHIP_OPERATOR
-
-// named comparison functions
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool is_eq(weak_equality __cmp) noexcept    { return __cmp == 0; }
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool is_neq(weak_equality __cmp) noexcept    { return __cmp != 0; }
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool is_lt(partial_ordering __cmp) noexcept { return __cmp < 0; }
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool is_lteq(partial_ordering __cmp) noexcept { return __cmp <= 0; }
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool is_gt(partial_ordering __cmp) noexcept { return __cmp > 0; }
-
-_LIBCPP_INLINE_VISIBILITY
-constexpr bool is_gteq(partial_ordering __cmp) noexcept { return __cmp >= 0; }
-
-namespace __comp_detail {
-
-enum _ClassifyCompCategory : unsigned{
-  _None,
-  _WeakEq,
-  _StrongEq,
-  _PartialOrd,
-  _WeakOrd,
-  _StrongOrd,
-  _CCC_Size
-};
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-constexpr _ClassifyCompCategory __type_to_enum() noexcept {
-  if (is_same_v<_Tp, weak_equality>)
-    return _WeakEq;
-  if (is_same_v<_Tp, strong_equality>)
-    return _StrongEq;
-  if (is_same_v<_Tp, partial_ordering>)
-    return _PartialOrd;
-  if (is_same_v<_Tp, weak_ordering>)
-    return _WeakOrd;
-  if (is_same_v<_Tp, strong_ordering>)
-    return _StrongOrd;
-  return _None;
-}
-
-template <size_t _Size>
-constexpr _ClassifyCompCategory
-__compute_comp_type(std::array<_ClassifyCompCategory, _Size> __types) {
-  std::array<int, _CCC_Size> __seen = {};
-  for (auto __type : __types)
-    ++__seen[__type];
-  if (__seen[_None])
-    return _None;
-  if (__seen[_WeakEq])
-    return _WeakEq;
-  if (__seen[_StrongEq] && (__seen[_PartialOrd] || __seen[_WeakOrd]))
-    return _WeakEq;
-  if (__seen[_StrongEq])
-    return _StrongEq;
-  if (__seen[_PartialOrd])
-    return _PartialOrd;
-  if (__seen[_WeakOrd])
-    return _WeakOrd;
-  return _StrongOrd;
-}
-
-template <class ..._Ts>
-constexpr auto __get_comp_type() {
-  using _CCC = _ClassifyCompCategory;
-  constexpr array<_CCC, sizeof...(_Ts)> __type_kinds{{__comp_detail::__type_to_enum<_Ts>()...}};
-  constexpr _CCC _Cat = sizeof...(_Ts) == 0 ? _StrongOrd
-      : __compute_comp_type(__type_kinds);
-  if constexpr (_Cat == _None)
-    return void();
-  else if constexpr (_Cat == _WeakEq)
-    return weak_equality::equivalent;
-  else if constexpr (_Cat == _StrongEq)
-    return strong_equality::equivalent;
-  else if constexpr (_Cat == _PartialOrd)
-    return partial_ordering::equivalent;
-  else if constexpr (_Cat == _WeakOrd)
-    return weak_ordering::equivalent;
-  else if constexpr (_Cat == _StrongOrd)
-    return strong_ordering::equivalent;
-  else
-    static_assert(_Cat != _Cat, "unhandled case");
-}
-} // namespace __comp_detail
-
-// [cmp.common], common comparison category type
-template<class... _Ts>
-struct _LIBCPP_TEMPLATE_VIS common_comparison_category {
-  using type = decltype(__comp_detail::__get_comp_type<_Ts...>());
-};
-
-template<class... _Ts>
-using common_comparison_category_t = typename common_comparison_category<_Ts...>::type;
-
-// [cmp.alg], comparison algorithms
-// TODO: unimplemented
-template<class _Tp> constexpr strong_ordering strong_order(const _Tp& __lhs, const _Tp& __rhs);
-template<class _Tp> constexpr weak_ordering weak_order(const _Tp& __lhs, const _Tp& __rhs);
-template<class _Tp> constexpr partial_ordering partial_order(const _Tp& __lhs, const _Tp& __rhs);
-template<class _Tp> constexpr strong_equality strong_equal(const _Tp& __lhs, const _Tp& __rhs);
-template<class _Tp> constexpr weak_equality weak_equal(const _Tp& __lhs, const _Tp& __rhs);
-
-#endif // _LIBCPP_STD_VER > 17
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP_COMPARE
diff --git a/lib/libcxx/include/complex b/lib/libcxx/include/complex
deleted file mode 100644
index 8cf6a946d71..00000000000
--- a/lib/libcxx/include/complex
+++ /dev/null
@@ -1,1496 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- complex ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_COMPLEX
-#define _LIBCPP_COMPLEX
-
-/*
-    complex synopsis
-
-namespace std
-{
-
-template<class T>
-class complex
-{
-public:
-    typedef T value_type;
-
-    complex(const T& re = T(), const T& im = T()); // constexpr in C++14
-    complex(const complex&);  // constexpr in C++14
-    template<class X> complex(const complex<X>&);  // constexpr in C++14
-
-    T real() const; // constexpr in C++14
-    T imag() const; // constexpr in C++14
-
-    void real(T);
-    void imag(T);
-
-    complex<T>& operator= (const T&);
-    complex<T>& operator+=(const T&);
-    complex<T>& operator-=(const T&);
-    complex<T>& operator*=(const T&);
-    complex<T>& operator/=(const T&);
-
-    complex& operator=(const complex&);
-    template<class X> complex<T>& operator= (const complex<X>&);
-    template<class X> complex<T>& operator+=(const complex<X>&);
-    template<class X> complex<T>& operator-=(const complex<X>&);
-    template<class X> complex<T>& operator*=(const complex<X>&);
-    template<class X> complex<T>& operator/=(const complex<X>&);
-};
-
-template<>
-class complex<float>
-{
-public:
-    typedef float value_type;
-
-    constexpr complex(float re = 0.0f, float im = 0.0f);
-    explicit constexpr complex(const complex<double>&);
-    explicit constexpr complex(const complex<long double>&);
-
-    constexpr float real() const;
-    void real(float);
-    constexpr float imag() const;
-    void imag(float);
-
-    complex<float>& operator= (float);
-    complex<float>& operator+=(float);
-    complex<float>& operator-=(float);
-    complex<float>& operator*=(float);
-    complex<float>& operator/=(float);
-
-    complex<float>& operator=(const complex<float>&);
-    template<class X> complex<float>& operator= (const complex<X>&);
-    template<class X> complex<float>& operator+=(const complex<X>&);
-    template<class X> complex<float>& operator-=(const complex<X>&);
-    template<class X> complex<float>& operator*=(const complex<X>&);
-    template<class X> complex<float>& operator/=(const complex<X>&);
-};
-
-template<>
-class complex<double>
-{
-public:
-    typedef double value_type;
-
-    constexpr complex(double re = 0.0, double im = 0.0);
-    constexpr complex(const complex<float>&);
-    explicit constexpr complex(const complex<long double>&);
-
-    constexpr double real() const;
-    void real(double);
-    constexpr double imag() const;
-    void imag(double);
-
-    complex<double>& operator= (double);
-    complex<double>& operator+=(double);
-    complex<double>& operator-=(double);
-    complex<double>& operator*=(double);
-    complex<double>& operator/=(double);
-    complex<double>& operator=(const complex<double>&);
-
-    template<class X> complex<double>& operator= (const complex<X>&);
-    template<class X> complex<double>& operator+=(const complex<X>&);
-    template<class X> complex<double>& operator-=(const complex<X>&);
-    template<class X> complex<double>& operator*=(const complex<X>&);
-    template<class X> complex<double>& operator/=(const complex<X>&);
-};
-
-template<>
-class complex<long double>
-{
-public:
-    typedef long double value_type;
-
-    constexpr complex(long double re = 0.0L, long double im = 0.0L);
-    constexpr complex(const complex<float>&);
-    constexpr complex(const complex<double>&);
-
-    constexpr long double real() const;
-    void real(long double);
-    constexpr long double imag() const;
-    void imag(long double);
-
-    complex<long double>& operator=(const complex<long double>&);
-    complex<long double>& operator= (long double);
-    complex<long double>& operator+=(long double);
-    complex<long double>& operator-=(long double);
-    complex<long double>& operator*=(long double);
-    complex<long double>& operator/=(long double);
-
-    template<class X> complex<long double>& operator= (const complex<X>&);
-    template<class X> complex<long double>& operator+=(const complex<X>&);
-    template<class X> complex<long double>& operator-=(const complex<X>&);
-    template<class X> complex<long double>& operator*=(const complex<X>&);
-    template<class X> complex<long double>& operator/=(const complex<X>&);
-};
-
-// 26.3.6 operators:
-template<class T> complex<T> operator+(const complex<T>&, const complex<T>&);
-template<class T> complex<T> operator+(const complex<T>&, const T&);
-template<class T> complex<T> operator+(const T&, const complex<T>&);
-template<class T> complex<T> operator-(const complex<T>&, const complex<T>&);
-template<class T> complex<T> operator-(const complex<T>&, const T&);
-template<class T> complex<T> operator-(const T&, const complex<T>&);
-template<class T> complex<T> operator*(const complex<T>&, const complex<T>&);
-template<class T> complex<T> operator*(const complex<T>&, const T&);
-template<class T> complex<T> operator*(const T&, const complex<T>&);
-template<class T> complex<T> operator/(const complex<T>&, const complex<T>&);
-template<class T> complex<T> operator/(const complex<T>&, const T&);
-template<class T> complex<T> operator/(const T&, const complex<T>&);
-template<class T> complex<T> operator+(const complex<T>&);
-template<class T> complex<T> operator-(const complex<T>&);
-template<class T> bool operator==(const complex<T>&, const complex<T>&); // constexpr in C++14
-template<class T> bool operator==(const complex<T>&, const T&); // constexpr in C++14
-template<class T> bool operator==(const T&, const complex<T>&); // constexpr in C++14
-template<class T> bool operator!=(const complex<T>&, const complex<T>&); // constexpr in C++14
-template<class T> bool operator!=(const complex<T>&, const T&); // constexpr in C++14
-template<class T> bool operator!=(const T&, const complex<T>&); // constexpr in C++14
-
-template<class T, class charT, class traits>
-  basic_istream<charT, traits>&
-  operator>>(basic_istream<charT, traits>&, complex<T>&);
-template<class T, class charT, class traits>
-  basic_ostream<charT, traits>&
-  operator<<(basic_ostream<charT, traits>&, const complex<T>&);
-
-// 26.3.7 values:
-
-template<class T>              T real(const complex<T>&); // constexpr in C++14
-                     long double real(long double);       // constexpr in C++14
-                          double real(double);            // constexpr in C++14
-template<Integral T>      double real(T);                 // constexpr in C++14
-                          float  real(float);             // constexpr in C++14
-
-template<class T>              T imag(const complex<T>&); // constexpr in C++14
-                     long double imag(long double);       // constexpr in C++14
-                          double imag(double);            // constexpr in C++14
-template<Integral T>      double imag(T);                 // constexpr in C++14
-                          float  imag(float);             // constexpr in C++14
-
-template<class T> T abs(const complex<T>&);
-
-template<class T>              T arg(const complex<T>&);
-                     long double arg(long double);
-                          double arg(double);
-template<Integral T>      double arg(T);
-                          float  arg(float);
-
-template<class T>              T norm(const complex<T>&);
-                     long double norm(long double);
-                          double norm(double);
-template<Integral T>      double norm(T);
-                          float  norm(float);
-
-template<class T>      complex<T>           conj(const complex<T>&);
-                       complex<long double> conj(long double);
-                       complex<double>      conj(double);
-template<Integral T>   complex<double>      conj(T);
-                       complex<float>       conj(float);
-
-template<class T>    complex<T>           proj(const complex<T>&);
-                     complex<long double> proj(long double);
-                     complex<double>      proj(double);
-template<Integral T> complex<double>      proj(T);
-                     complex<float>       proj(float);
-
-template<class T> complex<T> polar(const T&, const T& = T());
-
-// 26.3.8 transcendentals:
-template<class T> complex<T> acos(const complex<T>&);
-template<class T> complex<T> asin(const complex<T>&);
-template<class T> complex<T> atan(const complex<T>&);
-template<class T> complex<T> acosh(const complex<T>&);
-template<class T> complex<T> asinh(const complex<T>&);
-template<class T> complex<T> atanh(const complex<T>&);
-template<class T> complex<T> cos (const complex<T>&);
-template<class T> complex<T> cosh (const complex<T>&);
-template<class T> complex<T> exp (const complex<T>&);
-template<class T> complex<T> log (const complex<T>&);
-template<class T> complex<T> log10(const complex<T>&);
-
-template<class T> complex<T> pow(const complex<T>&, const T&);
-template<class T> complex<T> pow(const complex<T>&, const complex<T>&);
-template<class T> complex<T> pow(const T&, const complex<T>&);
-
-template<class T> complex<T> sin (const complex<T>&);
-template<class T> complex<T> sinh (const complex<T>&);
-template<class T> complex<T> sqrt (const complex<T>&);
-template<class T> complex<T> tan (const complex<T>&);
-template<class T> complex<T> tanh (const complex<T>&);
-
-template<class T, class charT, class traits>
-  basic_istream<charT, traits>&
-  operator>>(basic_istream<charT, traits>& is, complex<T>& x);
-
-template<class T, class charT, class traits>
-  basic_ostream<charT, traits>&
-  operator<<(basic_ostream<charT, traits>& o, const complex<T>& x);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <type_traits>
-#include <stdexcept>
-#include <cmath>
-#include <sstream>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template<class _Tp> class _LIBCPP_TEMPLATE_VIS complex;
-
-template<class _Tp> complex<_Tp> operator*(const complex<_Tp>& __z, const complex<_Tp>& __w);
-template<class _Tp> complex<_Tp> operator/(const complex<_Tp>& __x, const complex<_Tp>& __y);
-
-template<class _Tp>
-class _LIBCPP_TEMPLATE_VIS complex
-{
-public:
-    typedef _Tp value_type;
-private:
-    value_type __re_;
-    value_type __im_;
-public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    complex(const value_type& __re = value_type(), const value_type& __im = value_type())
-        : __re_(__re), __im_(__im) {}
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    complex(const complex<_Xp>& __c)
-        : __re_(__c.real()), __im_(__c.imag()) {}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 value_type real() const {return __re_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 value_type imag() const {return __im_;}
-
-    _LIBCPP_INLINE_VISIBILITY void real(value_type __re) {__re_ = __re;}
-    _LIBCPP_INLINE_VISIBILITY void imag(value_type __im) {__im_ = __im;}
-
-    _LIBCPP_INLINE_VISIBILITY complex& operator= (const value_type& __re)
-        {__re_ = __re; __im_ = value_type(); return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator+=(const value_type& __re) {__re_ += __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator-=(const value_type& __re) {__re_ -= __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator*=(const value_type& __re) {__re_ *= __re; __im_ *= __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator/=(const value_type& __re) {__re_ /= __re; __im_ /= __re; return *this;}
-
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator= (const complex<_Xp>& __c)
-        {
-            __re_ = __c.real();
-            __im_ = __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator+=(const complex<_Xp>& __c)
-        {
-            __re_ += __c.real();
-            __im_ += __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator-=(const complex<_Xp>& __c)
-        {
-            __re_ -= __c.real();
-            __im_ -= __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator*=(const complex<_Xp>& __c)
-        {
-            *this = *this * complex(__c.real(), __c.imag());
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator/=(const complex<_Xp>& __c)
-        {
-            *this = *this / complex(__c.real(), __c.imag());
-            return *this;
-        }
-};
-
-template<> class _LIBCPP_TEMPLATE_VIS complex<double>;
-template<> class _LIBCPP_TEMPLATE_VIS complex<long double>;
-
-template<>
-class _LIBCPP_TEMPLATE_VIS complex<float>
-{
-    float __re_;
-    float __im_;
-public:
-    typedef float value_type;
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR complex(float __re = 0.0f, float __im = 0.0f)
-        : __re_(__re), __im_(__im) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit _LIBCPP_CONSTEXPR complex(const complex<double>& __c);
-    _LIBCPP_INLINE_VISIBILITY
-    explicit _LIBCPP_CONSTEXPR complex(const complex<long double>& __c);
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR float real() const {return __re_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR float imag() const {return __im_;}
-
-    _LIBCPP_INLINE_VISIBILITY void real(value_type __re) {__re_ = __re;}
-    _LIBCPP_INLINE_VISIBILITY void imag(value_type __im) {__im_ = __im;}
-
-    _LIBCPP_INLINE_VISIBILITY complex& operator= (float __re)
-        {__re_ = __re; __im_ = value_type(); return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator+=(float __re) {__re_ += __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator-=(float __re) {__re_ -= __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator*=(float __re) {__re_ *= __re; __im_ *= __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator/=(float __re) {__re_ /= __re; __im_ /= __re; return *this;}
-
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator= (const complex<_Xp>& __c)
-        {
-            __re_ = __c.real();
-            __im_ = __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator+=(const complex<_Xp>& __c)
-        {
-            __re_ += __c.real();
-            __im_ += __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator-=(const complex<_Xp>& __c)
-        {
-            __re_ -= __c.real();
-            __im_ -= __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator*=(const complex<_Xp>& __c)
-        {
-            *this = *this * complex(__c.real(), __c.imag());
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator/=(const complex<_Xp>& __c)
-        {
-            *this = *this / complex(__c.real(), __c.imag());
-            return *this;
-        }
-};
-
-template<>
-class _LIBCPP_TEMPLATE_VIS complex<double>
-{
-    double __re_;
-    double __im_;
-public:
-    typedef double value_type;
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR complex(double __re = 0.0, double __im = 0.0)
-        : __re_(__re), __im_(__im) {}
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR complex(const complex<float>& __c);
-    _LIBCPP_INLINE_VISIBILITY
-    explicit _LIBCPP_CONSTEXPR complex(const complex<long double>& __c);
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR double real() const {return __re_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR double imag() const {return __im_;}
-
-    _LIBCPP_INLINE_VISIBILITY void real(value_type __re) {__re_ = __re;}
-    _LIBCPP_INLINE_VISIBILITY void imag(value_type __im) {__im_ = __im;}
-
-    _LIBCPP_INLINE_VISIBILITY complex& operator= (double __re)
-        {__re_ = __re; __im_ = value_type(); return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator+=(double __re) {__re_ += __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator-=(double __re) {__re_ -= __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator*=(double __re) {__re_ *= __re; __im_ *= __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator/=(double __re) {__re_ /= __re; __im_ /= __re; return *this;}
-
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator= (const complex<_Xp>& __c)
-        {
-            __re_ = __c.real();
-            __im_ = __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator+=(const complex<_Xp>& __c)
-        {
-            __re_ += __c.real();
-            __im_ += __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator-=(const complex<_Xp>& __c)
-        {
-            __re_ -= __c.real();
-            __im_ -= __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator*=(const complex<_Xp>& __c)
-        {
-            *this = *this * complex(__c.real(), __c.imag());
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator/=(const complex<_Xp>& __c)
-        {
-            *this = *this / complex(__c.real(), __c.imag());
-            return *this;
-        }
-};
-
-template<>
-class _LIBCPP_TEMPLATE_VIS complex<long double>
-{
-    long double __re_;
-    long double __im_;
-public:
-    typedef long double value_type;
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR complex(long double __re = 0.0L, long double __im = 0.0L)
-        : __re_(__re), __im_(__im) {}
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR complex(const complex<float>& __c);
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR complex(const complex<double>& __c);
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR long double real() const {return __re_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR long double imag() const {return __im_;}
-
-    _LIBCPP_INLINE_VISIBILITY void real(value_type __re) {__re_ = __re;}
-    _LIBCPP_INLINE_VISIBILITY void imag(value_type __im) {__im_ = __im;}
-
-    _LIBCPP_INLINE_VISIBILITY complex& operator= (long double __re)
-        {__re_ = __re; __im_ = value_type(); return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator+=(long double __re) {__re_ += __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator-=(long double __re) {__re_ -= __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator*=(long double __re) {__re_ *= __re; __im_ *= __re; return *this;}
-    _LIBCPP_INLINE_VISIBILITY complex& operator/=(long double __re) {__re_ /= __re; __im_ /= __re; return *this;}
-
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator= (const complex<_Xp>& __c)
-        {
-            __re_ = __c.real();
-            __im_ = __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator+=(const complex<_Xp>& __c)
-        {
-            __re_ += __c.real();
-            __im_ += __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator-=(const complex<_Xp>& __c)
-        {
-            __re_ -= __c.real();
-            __im_ -= __c.imag();
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator*=(const complex<_Xp>& __c)
-        {
-            *this = *this * complex(__c.real(), __c.imag());
-            return *this;
-        }
-    template<class _Xp> _LIBCPP_INLINE_VISIBILITY complex& operator/=(const complex<_Xp>& __c)
-        {
-            *this = *this / complex(__c.real(), __c.imag());
-            return *this;
-        }
-};
-
-inline
-_LIBCPP_CONSTEXPR
-complex<float>::complex(const complex<double>& __c)
-    : __re_(__c.real()), __im_(__c.imag()) {}
-
-inline
-_LIBCPP_CONSTEXPR
-complex<float>::complex(const complex<long double>& __c)
-    : __re_(__c.real()), __im_(__c.imag()) {}
-
-inline
-_LIBCPP_CONSTEXPR
-complex<double>::complex(const complex<float>& __c)
-    : __re_(__c.real()), __im_(__c.imag()) {}
-
-inline
-_LIBCPP_CONSTEXPR
-complex<double>::complex(const complex<long double>& __c)
-    : __re_(__c.real()), __im_(__c.imag()) {}
-
-inline
-_LIBCPP_CONSTEXPR
-complex<long double>::complex(const complex<float>& __c)
-    : __re_(__c.real()), __im_(__c.imag()) {}
-
-inline
-_LIBCPP_CONSTEXPR
-complex<long double>::complex(const complex<double>& __c)
-    : __re_(__c.real()), __im_(__c.imag()) {}
-
-// 26.3.6 operators:
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator+(const complex<_Tp>& __x, const complex<_Tp>& __y)
-{
-    complex<_Tp> __t(__x);
-    __t += __y;
-    return __t;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator+(const complex<_Tp>& __x, const _Tp& __y)
-{
-    complex<_Tp> __t(__x);
-    __t += __y;
-    return __t;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator+(const _Tp& __x, const complex<_Tp>& __y)
-{
-    complex<_Tp> __t(__y);
-    __t += __x;
-    return __t;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator-(const complex<_Tp>& __x, const complex<_Tp>& __y)
-{
-    complex<_Tp> __t(__x);
-    __t -= __y;
-    return __t;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator-(const complex<_Tp>& __x, const _Tp& __y)
-{
-    complex<_Tp> __t(__x);
-    __t -= __y;
-    return __t;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator-(const _Tp& __x, const complex<_Tp>& __y)
-{
-    complex<_Tp> __t(-__y);
-    __t += __x;
-    return __t;
-}
-
-template<class _Tp>
-complex<_Tp>
-operator*(const complex<_Tp>& __z, const complex<_Tp>& __w)
-{
-    _Tp __a = __z.real();
-    _Tp __b = __z.imag();
-    _Tp __c = __w.real();
-    _Tp __d = __w.imag();
-    _Tp __ac = __a * __c;
-    _Tp __bd = __b * __d;
-    _Tp __ad = __a * __d;
-    _Tp __bc = __b * __c;
-    _Tp __x = __ac - __bd;
-    _Tp __y = __ad + __bc;
-    if (__libcpp_isnan_or_builtin(__x) && __libcpp_isnan_or_builtin(__y))
-    {
-        bool __recalc = false;
-        if (__libcpp_isinf_or_builtin(__a) || __libcpp_isinf_or_builtin(__b))
-        {
-            __a = copysign(__libcpp_isinf_or_builtin(__a) ? _Tp(1) : _Tp(0), __a);
-            __b = copysign(__libcpp_isinf_or_builtin(__b) ? _Tp(1) : _Tp(0), __b);
-            if (__libcpp_isnan_or_builtin(__c))
-                __c = copysign(_Tp(0), __c);
-            if (__libcpp_isnan_or_builtin(__d))
-                __d = copysign(_Tp(0), __d);
-            __recalc = true;
-        }
-        if (__libcpp_isinf_or_builtin(__c) || __libcpp_isinf_or_builtin(__d))
-        {
-            __c = copysign(__libcpp_isinf_or_builtin(__c) ? _Tp(1) : _Tp(0), __c);
-            __d = copysign(__libcpp_isinf_or_builtin(__d) ? _Tp(1) : _Tp(0), __d);
-            if (__libcpp_isnan_or_builtin(__a))
-                __a = copysign(_Tp(0), __a);
-            if (__libcpp_isnan_or_builtin(__b))
-                __b = copysign(_Tp(0), __b);
-            __recalc = true;
-        }
-        if (!__recalc && (__libcpp_isinf_or_builtin(__ac) || __libcpp_isinf_or_builtin(__bd) ||
-                          __libcpp_isinf_or_builtin(__ad) || __libcpp_isinf_or_builtin(__bc)))
-        {
-            if (__libcpp_isnan_or_builtin(__a))
-                __a = copysign(_Tp(0), __a);
-            if (__libcpp_isnan_or_builtin(__b))
-                __b = copysign(_Tp(0), __b);
-            if (__libcpp_isnan_or_builtin(__c))
-                __c = copysign(_Tp(0), __c);
-            if (__libcpp_isnan_or_builtin(__d))
-                __d = copysign(_Tp(0), __d);
-            __recalc = true;
-        }
-        if (__recalc)
-        {
-            __x = _Tp(INFINITY) * (__a * __c - __b * __d);
-            __y = _Tp(INFINITY) * (__a * __d + __b * __c);
-        }
-    }
-    return complex<_Tp>(__x, __y);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator*(const complex<_Tp>& __x, const _Tp& __y)
-{
-    complex<_Tp> __t(__x);
-    __t *= __y;
-    return __t;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator*(const _Tp& __x, const complex<_Tp>& __y)
-{
-    complex<_Tp> __t(__y);
-    __t *= __x;
-    return __t;
-}
-
-template<class _Tp>
-complex<_Tp>
-operator/(const complex<_Tp>& __z, const complex<_Tp>& __w)
-{
-    int __ilogbw = 0;
-    _Tp __a = __z.real();
-    _Tp __b = __z.imag();
-    _Tp __c = __w.real();
-    _Tp __d = __w.imag();
-    _Tp __logbw = logb(fmax(fabs(__c), fabs(__d)));
-    if (__libcpp_isfinite_or_builtin(__logbw))
-    {
-        __ilogbw = static_cast<int>(__logbw);
-        __c = scalbn(__c, -__ilogbw);
-        __d = scalbn(__d, -__ilogbw);
-    }
-    _Tp __denom = __c * __c + __d * __d;
-    _Tp __x = scalbn((__a * __c + __b * __d) / __denom, -__ilogbw);
-    _Tp __y = scalbn((__b * __c - __a * __d) / __denom, -__ilogbw);
-    if (__libcpp_isnan_or_builtin(__x) && __libcpp_isnan_or_builtin(__y))
-    {
-        if ((__denom == _Tp(0)) && (!__libcpp_isnan_or_builtin(__a) || !__libcpp_isnan_or_builtin(__b)))
-        {
-            __x = copysign(_Tp(INFINITY), __c) * __a;
-            __y = copysign(_Tp(INFINITY), __c) * __b;
-        }
-        else if ((__libcpp_isinf_or_builtin(__a) || __libcpp_isinf_or_builtin(__b)) && __libcpp_isfinite_or_builtin(__c) && __libcpp_isfinite_or_builtin(__d))
-        {
-            __a = copysign(__libcpp_isinf_or_builtin(__a) ? _Tp(1) : _Tp(0), __a);
-            __b = copysign(__libcpp_isinf_or_builtin(__b) ? _Tp(1) : _Tp(0), __b);
-            __x = _Tp(INFINITY) * (__a * __c + __b * __d);
-            __y = _Tp(INFINITY) * (__b * __c - __a * __d);
-        }
-        else if (__libcpp_isinf_or_builtin(__logbw) && __logbw > _Tp(0) && __libcpp_isfinite_or_builtin(__a) && __libcpp_isfinite_or_builtin(__b))
-        {
-            __c = copysign(__libcpp_isinf_or_builtin(__c) ? _Tp(1) : _Tp(0), __c);
-            __d = copysign(__libcpp_isinf_or_builtin(__d) ? _Tp(1) : _Tp(0), __d);
-            __x = _Tp(0) * (__a * __c + __b * __d);
-            __y = _Tp(0) * (__b * __c - __a * __d);
-        }
-    }
-    return complex<_Tp>(__x, __y);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator/(const complex<_Tp>& __x, const _Tp& __y)
-{
-    return complex<_Tp>(__x.real() / __y, __x.imag() / __y);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator/(const _Tp& __x, const complex<_Tp>& __y)
-{
-    complex<_Tp> __t(__x);
-    __t /= __y;
-    return __t;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator+(const complex<_Tp>& __x)
-{
-    return __x;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-operator-(const complex<_Tp>& __x)
-{
-    return complex<_Tp>(-__x.real(), -__x.imag());
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator==(const complex<_Tp>& __x, const complex<_Tp>& __y)
-{
-    return __x.real() == __y.real() && __x.imag() == __y.imag();
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator==(const complex<_Tp>& __x, const _Tp& __y)
-{
-    return __x.real() == __y && __x.imag() == 0;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator==(const _Tp& __x, const complex<_Tp>& __y)
-{
-    return __x == __y.real() && 0 == __y.imag();
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator!=(const complex<_Tp>& __x, const complex<_Tp>& __y)
-{
-    return !(__x == __y);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator!=(const complex<_Tp>& __x, const _Tp& __y)
-{
-    return !(__x == __y);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator!=(const _Tp& __x, const complex<_Tp>& __y)
-{
-    return !(__x == __y);
-}
-
-// 26.3.7 values:
-
-template <class _Tp, bool = is_integral<_Tp>::value,
-                     bool = is_floating_point<_Tp>::value
-                     >
-struct __libcpp_complex_overload_traits {};
-
-// Integral Types
-template <class _Tp>
-struct __libcpp_complex_overload_traits<_Tp, true, false>
-{
-    typedef double _ValueType;
-    typedef complex<double> _ComplexType;
-};
-
-// Floating point types
-template <class _Tp>
-struct __libcpp_complex_overload_traits<_Tp, false, true>
-{
-    typedef _Tp _ValueType;
-    typedef complex<_Tp> _ComplexType;
-};
-
-// real
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-real(const complex<_Tp>& __c)
-{
-    return __c.real();
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename __libcpp_complex_overload_traits<_Tp>::_ValueType
-real(_Tp __re)
-{
-    return __re;
-}
-
-// imag
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp
-imag(const complex<_Tp>& __c)
-{
-    return __c.imag();
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename __libcpp_complex_overload_traits<_Tp>::_ValueType
-imag(_Tp)
-{
-    return 0;
-}
-
-// abs
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-abs(const complex<_Tp>& __c)
-{
-    return hypot(__c.real(), __c.imag());
-}
-
-// arg
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-arg(const complex<_Tp>& __c)
-{
-    return atan2(__c.imag(), __c.real());
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if<
-    is_same<_Tp, long double>::value,
-    long double
->::type
-arg(_Tp __re)
-{
-    return atan2l(0.L, __re);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value || is_same<_Tp, double>::value,
-    double
->::type
-arg(_Tp __re)
-{
-    return atan2(0., __re);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if<
-    is_same<_Tp, float>::value,
-    float
->::type
-arg(_Tp __re)
-{
-    return atan2f(0.F, __re);
-}
-
-// norm
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-norm(const complex<_Tp>& __c)
-{
-    if (__libcpp_isinf_or_builtin(__c.real()))
-        return abs(__c.real());
-    if (__libcpp_isinf_or_builtin(__c.imag()))
-        return abs(__c.imag());
-    return __c.real() * __c.real() + __c.imag() * __c.imag();
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __libcpp_complex_overload_traits<_Tp>::_ValueType
-norm(_Tp __re)
-{
-    typedef typename __libcpp_complex_overload_traits<_Tp>::_ValueType _ValueType;
-    return static_cast<_ValueType>(__re) * __re;
-}
-
-// conj
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-conj(const complex<_Tp>& __c)
-{
-    return complex<_Tp>(__c.real(), -__c.imag());
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __libcpp_complex_overload_traits<_Tp>::_ComplexType
-conj(_Tp __re)
-{
-    typedef typename __libcpp_complex_overload_traits<_Tp>::_ComplexType _ComplexType;
-    return _ComplexType(__re);
-}
-
-
-
-// proj
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-proj(const complex<_Tp>& __c)
-{
-    std::complex<_Tp> __r = __c;
-    if (__libcpp_isinf_or_builtin(__c.real()) || __libcpp_isinf_or_builtin(__c.imag()))
-        __r = complex<_Tp>(INFINITY, copysign(_Tp(0), __c.imag()));
-    return __r;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_floating_point<_Tp>::value,
-    typename __libcpp_complex_overload_traits<_Tp>::_ComplexType
->::type
-proj(_Tp __re)
-{
-    if (__libcpp_isinf_or_builtin(__re))
-        __re = abs(__re);
-    return complex<_Tp>(__re);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_integral<_Tp>::value,
-    typename __libcpp_complex_overload_traits<_Tp>::_ComplexType
->::type
-proj(_Tp __re)
-{
-    typedef typename __libcpp_complex_overload_traits<_Tp>::_ComplexType _ComplexType;
-    return _ComplexType(__re);
-}
-
-// polar
-
-template<class _Tp>
-complex<_Tp>
-polar(const _Tp& __rho, const _Tp& __theta = _Tp())
-{
-    if (__libcpp_isnan_or_builtin(__rho) || signbit(__rho))
-        return complex<_Tp>(_Tp(NAN), _Tp(NAN));
-    if (__libcpp_isnan_or_builtin(__theta))
-    {
-        if (__libcpp_isinf_or_builtin(__rho))
-            return complex<_Tp>(__rho, __theta);
-        return complex<_Tp>(__theta, __theta);
-    }
-    if (__libcpp_isinf_or_builtin(__theta))
-    {
-        if (__libcpp_isinf_or_builtin(__rho))
-            return complex<_Tp>(__rho, _Tp(NAN));
-        return complex<_Tp>(_Tp(NAN), _Tp(NAN));
-    }
-    _Tp __x = __rho * cos(__theta);
-    if (__libcpp_isnan_or_builtin(__x))
-        __x = 0;
-    _Tp __y = __rho * sin(__theta);
-    if (__libcpp_isnan_or_builtin(__y))
-        __y = 0;
-    return complex<_Tp>(__x, __y);
-}
-
-// log
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-log(const complex<_Tp>& __x)
-{
-    return complex<_Tp>(log(abs(__x)), arg(__x));
-}
-
-// log10
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-log10(const complex<_Tp>& __x)
-{
-    return log(__x) / log(_Tp(10));
-}
-
-// sqrt
-
-template<class _Tp>
-complex<_Tp>
-sqrt(const complex<_Tp>& __x)
-{
-    if (__libcpp_isinf_or_builtin(__x.imag()))
-        return complex<_Tp>(_Tp(INFINITY), __x.imag());
-    if (__libcpp_isinf_or_builtin(__x.real()))
-    {
-        if (__x.real() > _Tp(0))
-            return complex<_Tp>(__x.real(), __libcpp_isnan_or_builtin(__x.imag()) ? __x.imag() : copysign(_Tp(0), __x.imag()));
-        return complex<_Tp>(__libcpp_isnan_or_builtin(__x.imag()) ? __x.imag() : _Tp(0), copysign(__x.real(), __x.imag()));
-    }
-    return polar(sqrt(abs(__x)), arg(__x) / _Tp(2));
-}
-
-// exp
-
-template<class _Tp>
-complex<_Tp>
-exp(const complex<_Tp>& __x)
-{
-    _Tp __i = __x.imag();
-    if (__libcpp_isinf_or_builtin(__x.real()))
-    {
-        if (__x.real() < _Tp(0))
-        {
-            if (!__libcpp_isfinite_or_builtin(__i))
-                __i = _Tp(1);
-        }
-        else if (__i == 0 || !__libcpp_isfinite_or_builtin(__i))
-        {
-            if (__libcpp_isinf_or_builtin(__i))
-                __i = _Tp(NAN);
-            return complex<_Tp>(__x.real(), __i);
-        }
-    }
-    else if (__libcpp_isnan_or_builtin(__x.real()) && __x.imag() == 0)
-        return __x;
-    _Tp __e = exp(__x.real());
-    return complex<_Tp>(__e * cos(__i), __e * sin(__i));
-}
-
-// pow
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-pow(const complex<_Tp>& __x, const complex<_Tp>& __y)
-{
-    return exp(__y * log(__x));
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<typename __promote<_Tp, _Up>::type>
-pow(const complex<_Tp>& __x, const complex<_Up>& __y)
-{
-    typedef complex<typename __promote<_Tp, _Up>::type> result_type;
-    return _VSTD::pow(result_type(__x), result_type(__y));
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_arithmetic<_Up>::value,
-    complex<typename __promote<_Tp, _Up>::type>
->::type
-pow(const complex<_Tp>& __x, const _Up& __y)
-{
-    typedef complex<typename __promote<_Tp, _Up>::type> result_type;
-    return _VSTD::pow(result_type(__x), result_type(__y));
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_arithmetic<_Tp>::value,
-    complex<typename __promote<_Tp, _Up>::type>
->::type
-pow(const _Tp& __x, const complex<_Up>& __y)
-{
-    typedef complex<typename __promote<_Tp, _Up>::type> result_type;
-    return _VSTD::pow(result_type(__x), result_type(__y));
-}
-
-// __sqr, computes pow(x, 2)
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-__sqr(const complex<_Tp>& __x)
-{
-    return complex<_Tp>((__x.real() - __x.imag()) * (__x.real() + __x.imag()),
-                        _Tp(2) * __x.real() * __x.imag());
-}
-
-// asinh
-
-template<class _Tp>
-complex<_Tp>
-asinh(const complex<_Tp>& __x)
-{
-    const _Tp __pi(atan2(+0., -0.));
-    if (__libcpp_isinf_or_builtin(__x.real()))
-    {
-        if (__libcpp_isnan_or_builtin(__x.imag()))
-            return __x;
-        if (__libcpp_isinf_or_builtin(__x.imag()))
-            return complex<_Tp>(__x.real(), copysign(__pi * _Tp(0.25), __x.imag()));
-        return complex<_Tp>(__x.real(), copysign(_Tp(0), __x.imag()));
-    }
-    if (__libcpp_isnan_or_builtin(__x.real()))
-    {
-        if (__libcpp_isinf_or_builtin(__x.imag()))
-            return complex<_Tp>(__x.imag(), __x.real());
-        if (__x.imag() == 0)
-            return __x;
-        return complex<_Tp>(__x.real(), __x.real());
-    }
-    if (__libcpp_isinf_or_builtin(__x.imag()))
-        return complex<_Tp>(copysign(__x.imag(), __x.real()), copysign(__pi/_Tp(2), __x.imag()));
-    complex<_Tp> __z = log(__x + sqrt(__sqr(__x) + _Tp(1)));
-    return complex<_Tp>(copysign(__z.real(), __x.real()), copysign(__z.imag(), __x.imag()));
-}
-
-// acosh
-
-template<class _Tp>
-complex<_Tp>
-acosh(const complex<_Tp>& __x)
-{
-    const _Tp __pi(atan2(+0., -0.));
-    if (__libcpp_isinf_or_builtin(__x.real()))
-    {
-        if (__libcpp_isnan_or_builtin(__x.imag()))
-            return complex<_Tp>(abs(__x.real()), __x.imag());
-        if (__libcpp_isinf_or_builtin(__x.imag()))
-        {
-            if (__x.real() > 0)
-                return complex<_Tp>(__x.real(), copysign(__pi * _Tp(0.25), __x.imag()));
-            else
-                return complex<_Tp>(-__x.real(), copysign(__pi * _Tp(0.75), __x.imag()));
-        }
-        if (__x.real() < 0)
-            return complex<_Tp>(-__x.real(), copysign(__pi, __x.imag()));
-        return complex<_Tp>(__x.real(), copysign(_Tp(0), __x.imag()));
-    }
-    if (__libcpp_isnan_or_builtin(__x.real()))
-    {
-        if (__libcpp_isinf_or_builtin(__x.imag()))
-            return complex<_Tp>(abs(__x.imag()), __x.real());
-        return complex<_Tp>(__x.real(), __x.real());
-    }
-    if (__libcpp_isinf_or_builtin(__x.imag()))
-        return complex<_Tp>(abs(__x.imag()), copysign(__pi/_Tp(2), __x.imag()));
-    complex<_Tp> __z = log(__x + sqrt(__sqr(__x) - _Tp(1)));
-    return complex<_Tp>(copysign(__z.real(), _Tp(0)), copysign(__z.imag(), __x.imag()));
-}
-
-// atanh
-
-template<class _Tp>
-complex<_Tp>
-atanh(const complex<_Tp>& __x)
-{
-    const _Tp __pi(atan2(+0., -0.));
-    if (__libcpp_isinf_or_builtin(__x.imag()))
-    {
-        return complex<_Tp>(copysign(_Tp(0), __x.real()), copysign(__pi/_Tp(2), __x.imag()));
-    }
-    if (__libcpp_isnan_or_builtin(__x.imag()))
-    {
-        if (__libcpp_isinf_or_builtin(__x.real()) || __x.real() == 0)
-            return complex<_Tp>(copysign(_Tp(0), __x.real()), __x.imag());
-        return complex<_Tp>(__x.imag(), __x.imag());
-    }
-    if (__libcpp_isnan_or_builtin(__x.real()))
-    {
-        return complex<_Tp>(__x.real(), __x.real());
-    }
-    if (__libcpp_isinf_or_builtin(__x.real()))
-    {
-        return complex<_Tp>(copysign(_Tp(0), __x.real()), copysign(__pi/_Tp(2), __x.imag()));
-    }
-    if (abs(__x.real()) == _Tp(1) && __x.imag() == _Tp(0))
-    {
-        return complex<_Tp>(copysign(_Tp(INFINITY), __x.real()), copysign(_Tp(0), __x.imag()));
-    }
-    complex<_Tp> __z = log((_Tp(1) + __x) / (_Tp(1) - __x)) / _Tp(2);
-    return complex<_Tp>(copysign(__z.real(), __x.real()), copysign(__z.imag(), __x.imag()));
-}
-
-// sinh
-
-template<class _Tp>
-complex<_Tp>
-sinh(const complex<_Tp>& __x)
-{
-    if (__libcpp_isinf_or_builtin(__x.real()) && !__libcpp_isfinite_or_builtin(__x.imag()))
-        return complex<_Tp>(__x.real(), _Tp(NAN));
-    if (__x.real() == 0 && !__libcpp_isfinite_or_builtin(__x.imag()))
-        return complex<_Tp>(__x.real(), _Tp(NAN));
-    if (__x.imag() == 0 && !__libcpp_isfinite_or_builtin(__x.real()))
-        return __x;
-    return complex<_Tp>(sinh(__x.real()) * cos(__x.imag()), cosh(__x.real()) * sin(__x.imag()));
-}
-
-// cosh
-
-template<class _Tp>
-complex<_Tp>
-cosh(const complex<_Tp>& __x)
-{
-    if (__libcpp_isinf_or_builtin(__x.real()) && !__libcpp_isfinite_or_builtin(__x.imag()))
-        return complex<_Tp>(abs(__x.real()), _Tp(NAN));
-    if (__x.real() == 0 && !__libcpp_isfinite_or_builtin(__x.imag()))
-        return complex<_Tp>(_Tp(NAN), __x.real());
-    if (__x.real() == 0 && __x.imag() == 0)
-        return complex<_Tp>(_Tp(1), __x.imag());
-    if (__x.imag() == 0 && !__libcpp_isfinite_or_builtin(__x.real()))
-        return complex<_Tp>(abs(__x.real()), __x.imag());
-    return complex<_Tp>(cosh(__x.real()) * cos(__x.imag()), sinh(__x.real()) * sin(__x.imag()));
-}
-
-// tanh
-
-template<class _Tp>
-complex<_Tp>
-tanh(const complex<_Tp>& __x)
-{
-    if (__libcpp_isinf_or_builtin(__x.real()))
-    {
-        if (!__libcpp_isfinite_or_builtin(__x.imag()))
-            return complex<_Tp>(_Tp(1), _Tp(0));
-        return complex<_Tp>(_Tp(1), copysign(_Tp(0), sin(_Tp(2) * __x.imag())));
-    }
-    if (__libcpp_isnan_or_builtin(__x.real()) && __x.imag() == 0)
-        return __x;
-    _Tp __2r(_Tp(2) * __x.real());
-    _Tp __2i(_Tp(2) * __x.imag());
-    _Tp __d(cosh(__2r) + cos(__2i));
-    _Tp __2rsh(sinh(__2r));
-    if (__libcpp_isinf_or_builtin(__2rsh) && __libcpp_isinf_or_builtin(__d))
-        return complex<_Tp>(__2rsh > _Tp(0) ? _Tp(1) : _Tp(-1),
-                            __2i > _Tp(0) ? _Tp(0) : _Tp(-0.));
-    return  complex<_Tp>(__2rsh/__d, sin(__2i)/__d);
-}
-
-// asin
-
-template<class _Tp>
-complex<_Tp>
-asin(const complex<_Tp>& __x)
-{
-    complex<_Tp> __z = asinh(complex<_Tp>(-__x.imag(), __x.real()));
-    return complex<_Tp>(__z.imag(), -__z.real());
-}
-
-// acos
-
-template<class _Tp>
-complex<_Tp>
-acos(const complex<_Tp>& __x)
-{
-    const _Tp __pi(atan2(+0., -0.));
-    if (__libcpp_isinf_or_builtin(__x.real()))
-    {
-        if (__libcpp_isnan_or_builtin(__x.imag()))
-            return complex<_Tp>(__x.imag(), __x.real());
-        if (__libcpp_isinf_or_builtin(__x.imag()))
-        {
-            if (__x.real() < _Tp(0))
-                return complex<_Tp>(_Tp(0.75) * __pi, -__x.imag());
-            return complex<_Tp>(_Tp(0.25) * __pi, -__x.imag());
-        }
-        if (__x.real() < _Tp(0))
-            return complex<_Tp>(__pi, signbit(__x.imag()) ? -__x.real() : __x.real());
-        return complex<_Tp>(_Tp(0), signbit(__x.imag()) ? __x.real() : -__x.real());
-    }
-    if (__libcpp_isnan_or_builtin(__x.real()))
-    {
-        if (__libcpp_isinf_or_builtin(__x.imag()))
-            return complex<_Tp>(__x.real(), -__x.imag());
-        return complex<_Tp>(__x.real(), __x.real());
-    }
-    if (__libcpp_isinf_or_builtin(__x.imag()))
-        return complex<_Tp>(__pi/_Tp(2), -__x.imag());
-    if (__x.real() == 0 && (__x.imag() == 0 || isnan(__x.imag())))
-        return complex<_Tp>(__pi/_Tp(2), -__x.imag());
-    complex<_Tp> __z = log(__x + sqrt(__sqr(__x) - _Tp(1)));
-    if (signbit(__x.imag()))
-        return complex<_Tp>(abs(__z.imag()), abs(__z.real()));
-    return complex<_Tp>(abs(__z.imag()), -abs(__z.real()));
-}
-
-// atan
-
-template<class _Tp>
-complex<_Tp>
-atan(const complex<_Tp>& __x)
-{
-    complex<_Tp> __z = atanh(complex<_Tp>(-__x.imag(), __x.real()));
-    return complex<_Tp>(__z.imag(), -__z.real());
-}
-
-// sin
-
-template<class _Tp>
-complex<_Tp>
-sin(const complex<_Tp>& __x)
-{
-    complex<_Tp> __z = sinh(complex<_Tp>(-__x.imag(), __x.real()));
-    return complex<_Tp>(__z.imag(), -__z.real());
-}
-
-// cos
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-complex<_Tp>
-cos(const complex<_Tp>& __x)
-{
-    return cosh(complex<_Tp>(-__x.imag(), __x.real()));
-}
-
-// tan
-
-template<class _Tp>
-complex<_Tp>
-tan(const complex<_Tp>& __x)
-{
-    complex<_Tp> __z = tanh(complex<_Tp>(-__x.imag(), __x.real()));
-    return complex<_Tp>(__z.imag(), -__z.real());
-}
-
-template<class _Tp, class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, complex<_Tp>& __x)
-{
-    if (__is.good())
-    {
-        ws(__is);
-        if (__is.peek() == _CharT('('))
-        {
-            __is.get();
-            _Tp __r;
-            __is >> __r;
-            if (!__is.fail())
-            {
-                ws(__is);
-                _CharT __c = __is.peek();
-                if (__c == _CharT(','))
-                {
-                    __is.get();
-                    _Tp __i;
-                    __is >> __i;
-                    if (!__is.fail())
-                    {
-                        ws(__is);
-                        __c = __is.peek();
-                        if (__c == _CharT(')'))
-                        {
-                            __is.get();
-                            __x = complex<_Tp>(__r, __i);
-                        }
-                        else
-                            __is.setstate(ios_base::failbit);
-                    }
-                    else
-                        __is.setstate(ios_base::failbit);
-                }
-                else if (__c == _CharT(')'))
-                {
-                    __is.get();
-                    __x = complex<_Tp>(__r, _Tp(0));
-                }
-                else
-                    __is.setstate(ios_base::failbit);
-            }
-            else
-                __is.setstate(ios_base::failbit);
-        }
-        else
-        {
-            _Tp __r;
-            __is >> __r;
-            if (!__is.fail())
-                __x = complex<_Tp>(__r, _Tp(0));
-            else
-                __is.setstate(ios_base::failbit);
-        }
-    }
-    else
-        __is.setstate(ios_base::failbit);
-    return __is;
-}
-
-template<class _Tp, class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const complex<_Tp>& __x)
-{
-    basic_ostringstream<_CharT, _Traits> __s;
-    __s.flags(__os.flags());
-    __s.imbue(__os.getloc());
-    __s.precision(__os.precision());
-    __s << '(' << __x.real() << ',' << __x.imag() << ')';
-    return __os << __s.str();
-}
-
-#if _LIBCPP_STD_VER > 11 
-// Literal suffix for complex number literals [complex.literals]
-inline namespace literals
-{ 
-  inline namespace complex_literals
-  {
-    constexpr complex<long double> operator""il(long double __im)
-    {
-        return { 0.0l, __im };
-    }
-
-    constexpr complex<long double> operator""il(unsigned long long __im)
-    {
-        return { 0.0l, static_cast<long double>(__im) };
-    }
-
-
-    constexpr complex<double> operator""i(long double __im)
-    {
-        return { 0.0, static_cast<double>(__im) };
-    }
-
-    constexpr complex<double> operator""i(unsigned long long __im)
-    {
-        return { 0.0, static_cast<double>(__im) };
-    }
-
-
-    constexpr complex<float> operator""if(long double __im)
-    {
-        return { 0.0f, static_cast<float>(__im) };
-    }
-
-    constexpr complex<float> operator""if(unsigned long long __im)
-    {
-        return { 0.0f, static_cast<float>(__im) };
-    }
-  }
-}
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_COMPLEX
diff --git a/lib/libcxx/include/complex.h b/lib/libcxx/include/complex.h
deleted file mode 100644
index c2359665add..00000000000
--- a/lib/libcxx/include/complex.h
+++ /dev/null
@@ -1,37 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- complex.h --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_COMPLEX_H
-#define _LIBCPP_COMPLEX_H
-
-/*
-    complex.h synopsis
-
-#include <ccomplex>
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef __cplusplus
-
-#include <ccomplex>
-
-#else  // __cplusplus
-
-#include_next <complex.h>
-
-#endif  // __cplusplus
-
-#endif  // _LIBCPP_COMPLEX_H
diff --git a/lib/libcxx/include/condition_variable b/lib/libcxx/include/condition_variable
deleted file mode 100644
index c45a326d898..00000000000
--- a/lib/libcxx/include/condition_variable
+++ /dev/null
@@ -1,269 +0,0 @@
-// -*- C++ -*-
-//===---------------------- condition_variable ----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CONDITION_VARIABLE
-#define _LIBCPP_CONDITION_VARIABLE
-
-/*
-    condition_variable synopsis
-
-namespace std
-{
-
-enum class cv_status { no_timeout, timeout };
-
-class condition_variable
-{
-public:
-    condition_variable();
-    ~condition_variable();
-
-    condition_variable(const condition_variable&) = delete;
-    condition_variable& operator=(const condition_variable&) = delete;
-
-    void notify_one() noexcept;
-    void notify_all() noexcept;
-
-    void wait(unique_lock<mutex>& lock);
-    template <class Predicate>
-        void wait(unique_lock<mutex>& lock, Predicate pred);
-
-    template <class Clock, class Duration>
-        cv_status
-        wait_until(unique_lock<mutex>& lock,
-                   const chrono::time_point<Clock, Duration>& abs_time);
-
-    template <class Clock, class Duration, class Predicate>
-        bool
-        wait_until(unique_lock<mutex>& lock,
-                   const chrono::time_point<Clock, Duration>& abs_time,
-                   Predicate pred);
-
-    template <class Rep, class Period>
-        cv_status
-        wait_for(unique_lock<mutex>& lock,
-                 const chrono::duration<Rep, Period>& rel_time);
-
-    template <class Rep, class Period, class Predicate>
-        bool
-        wait_for(unique_lock<mutex>& lock,
-                 const chrono::duration<Rep, Period>& rel_time,
-                 Predicate pred);
-
-    typedef pthread_cond_t* native_handle_type;
-    native_handle_type native_handle();
-};
-
-void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk);
-
-class condition_variable_any
-{
-public:
-    condition_variable_any();
-    ~condition_variable_any();
-
-    condition_variable_any(const condition_variable_any&) = delete;
-    condition_variable_any& operator=(const condition_variable_any&) = delete;
-
-    void notify_one() noexcept;
-    void notify_all() noexcept;
-
-    template <class Lock>
-        void wait(Lock& lock);
-    template <class Lock, class Predicate>
-        void wait(Lock& lock, Predicate pred);
-
-    template <class Lock, class Clock, class Duration>
-        cv_status
-        wait_until(Lock& lock,
-                   const chrono::time_point<Clock, Duration>& abs_time);
-
-    template <class Lock, class Clock, class Duration, class Predicate>
-        bool
-        wait_until(Lock& lock,
-                   const chrono::time_point<Clock, Duration>& abs_time,
-                   Predicate pred);
-
-    template <class Lock, class Rep, class Period>
-        cv_status
-        wait_for(Lock& lock,
-                 const chrono::duration<Rep, Period>& rel_time);
-
-    template <class Lock, class Rep, class Period, class Predicate>
-        bool
-        wait_for(Lock& lock,
-                 const chrono::duration<Rep, Period>& rel_time,
-                 Predicate pred);
-};
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__mutex_base>
-#include <memory>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifndef _LIBCPP_HAS_NO_THREADS
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-class _LIBCPP_TYPE_VIS condition_variable_any
-{
-    condition_variable __cv_;
-    shared_ptr<mutex>  __mut_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    condition_variable_any();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void notify_one() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    void notify_all() _NOEXCEPT;
-
-    template <class _Lock>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        void wait(_Lock& __lock);
-    template <class _Lock, class _Predicate>
-        _LIBCPP_INLINE_VISIBILITY
-        void wait(_Lock& __lock, _Predicate __pred);
-
-    template <class _Lock, class _Clock, class _Duration>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        cv_status
-        wait_until(_Lock& __lock,
-                   const chrono::time_point<_Clock, _Duration>& __t);
-
-    template <class _Lock, class _Clock, class _Duration, class _Predicate>
-        bool
-        _LIBCPP_INLINE_VISIBILITY
-        wait_until(_Lock& __lock,
-                   const chrono::time_point<_Clock, _Duration>& __t,
-                   _Predicate __pred);
-
-    template <class _Lock, class _Rep, class _Period>
-        cv_status
-        _LIBCPP_INLINE_VISIBILITY
-        wait_for(_Lock& __lock,
-                 const chrono::duration<_Rep, _Period>& __d);
-
-    template <class _Lock, class _Rep, class _Period, class _Predicate>
-        bool
-        _LIBCPP_INLINE_VISIBILITY
-        wait_for(_Lock& __lock,
-                 const chrono::duration<_Rep, _Period>& __d,
-                 _Predicate __pred);
-};
-
-inline
-condition_variable_any::condition_variable_any()
-    : __mut_(make_shared<mutex>()) {}
-
-inline
-void
-condition_variable_any::notify_one() _NOEXCEPT
-{
-    {lock_guard<mutex> __lx(*__mut_);}
-    __cv_.notify_one();
-}
-
-inline
-void
-condition_variable_any::notify_all() _NOEXCEPT
-{
-    {lock_guard<mutex> __lx(*__mut_);}
-    __cv_.notify_all();
-}
-
-struct __lock_external
-{
-    template <class _Lock>
-    void operator()(_Lock* __m) {__m->lock();}
-};
-
-template <class _Lock>
-void
-condition_variable_any::wait(_Lock& __lock)
-{
-    shared_ptr<mutex> __mut = __mut_;
-    unique_lock<mutex> __lk(*__mut);
-    __lock.unlock();
-    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
-    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
-    __cv_.wait(__lk);
-}  // __mut_.unlock(), __lock.lock()
-
-template <class _Lock, class _Predicate>
-inline
-void
-condition_variable_any::wait(_Lock& __lock, _Predicate __pred)
-{
-    while (!__pred())
-        wait(__lock);
-}
-
-template <class _Lock, class _Clock, class _Duration>
-cv_status
-condition_variable_any::wait_until(_Lock& __lock,
-                                   const chrono::time_point<_Clock, _Duration>& __t)
-{
-    shared_ptr<mutex> __mut = __mut_;
-    unique_lock<mutex> __lk(*__mut);
-    __lock.unlock();
-    unique_ptr<_Lock, __lock_external> __lxx(&__lock);
-    lock_guard<unique_lock<mutex> > __lx(__lk, adopt_lock);
-    return __cv_.wait_until(__lk, __t);
-}  // __mut_.unlock(), __lock.lock()
-
-template <class _Lock, class _Clock, class _Duration, class _Predicate>
-inline
-bool
-condition_variable_any::wait_until(_Lock& __lock,
-                                   const chrono::time_point<_Clock, _Duration>& __t,
-                                   _Predicate __pred)
-{
-    while (!__pred())
-        if (wait_until(__lock, __t) == cv_status::timeout)
-            return __pred();
-    return true;
-}
-
-template <class _Lock, class _Rep, class _Period>
-inline
-cv_status
-condition_variable_any::wait_for(_Lock& __lock,
-                                 const chrono::duration<_Rep, _Period>& __d)
-{
-    return wait_until(__lock, chrono::steady_clock::now() + __d);
-}
-
-template <class _Lock, class _Rep, class _Period, class _Predicate>
-inline
-bool
-condition_variable_any::wait_for(_Lock& __lock,
-                                 const chrono::duration<_Rep, _Period>& __d,
-                                 _Predicate __pred)
-{
-    return wait_until(__lock, chrono::steady_clock::now() + __d,
-                      _VSTD::move(__pred));
-}
-
-_LIBCPP_FUNC_VIS
-void notify_all_at_thread_exit(condition_variable& cond, unique_lock<mutex> lk);
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // !_LIBCPP_HAS_NO_THREADS
-
-#endif  // _LIBCPP_CONDITION_VARIABLE
diff --git a/lib/libcxx/include/csetjmp b/lib/libcxx/include/csetjmp
deleted file mode 100644
index 58a9c73ab56..00000000000
--- a/lib/libcxx/include/csetjmp
+++ /dev/null
@@ -1,48 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- csetjmp ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CSETJMP
-#define _LIBCPP_CSETJMP
-
-/*
-    csetjmp synopsis
-
-Macros:
-
-    setjmp
-
-namespace std
-{
-
-Types:
-
-    jmp_buf
-
-void longjmp(jmp_buf env, int val);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <setjmp.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::jmp_buf;
-using ::longjmp;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CSETJMP
diff --git a/lib/libcxx/include/csignal b/lib/libcxx/include/csignal
deleted file mode 100644
index 97282661872..00000000000
--- a/lib/libcxx/include/csignal
+++ /dev/null
@@ -1,58 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- csignal ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CSIGNAL
-#define _LIBCPP_CSIGNAL
-
-/*
-    csignal synopsis
-
-Macros:
-
-    SIG_DFL
-    SIG_ERR
-    SIG_IGN
-    SIGABRT
-    SIGFPE
-    SIGILL
-    SIGINT
-    SIGSEGV
-    SIGTERM
-
-namespace std
-{
-
-Types:
-
-    sig_atomic_t
-
-void (*signal(int sig, void (*func)(int)))(int);
-int raise(int sig);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <signal.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::sig_atomic_t;
-using ::signal;
-using ::raise;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CSIGNAL
diff --git a/lib/libcxx/include/cstdarg b/lib/libcxx/include/cstdarg
deleted file mode 100644
index c8b6999242f..00000000000
--- a/lib/libcxx/include/cstdarg
+++ /dev/null
@@ -1,48 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cstdarg ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CSTDARG
-#define _LIBCPP_CSTDARG
-
-/*
-    cstdarg synopsis
-
-Macros:
-
-    type va_arg(va_list ap, type);
-    void va_copy(va_list dest, va_list src);  // C99
-    void va_end(va_list ap);
-    void va_start(va_list ap, parmN);
-
-namespace std
-{
-
-Types:
-
-    va_list
-
-}  // std
-
-*/
-
-#include <__config>
-#include <stdarg.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::va_list;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CSTDARG
diff --git a/lib/libcxx/include/cstdbool b/lib/libcxx/include/cstdbool
deleted file mode 100644
index 2c764a61f21..00000000000
--- a/lib/libcxx/include/cstdbool
+++ /dev/null
@@ -1,32 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cstdbool ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CSTDBOOL
-#define _LIBCPP_CSTDBOOL
-
-/*
-    cstdbool synopsis
-
-Macros:
-
-    __bool_true_false_are_defined
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#undef __bool_true_false_are_defined
-#define __bool_true_false_are_defined 1
-
-#endif  // _LIBCPP_CSTDBOOL
diff --git a/lib/libcxx/include/cstddef b/lib/libcxx/include/cstddef
deleted file mode 100644
index b4c42b19ddb..00000000000
--- a/lib/libcxx/include/cstddef
+++ /dev/null
@@ -1,114 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cstddef ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CSTDDEF
-#define _LIBCPP_CSTDDEF
-
-/*
-    cstddef synopsis
-
-Macros:
-
-    offsetof(type,member-designator)
-    NULL
-
-namespace std
-{
-
-Types:
-
-    ptrdiff_t
-    size_t
-    max_align_t
-    nullptr_t
-    byte // C++17
-
-}  // std
-
-*/
-
-#include <__config>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-// Don't include our own <stddef.h>; we don't want to declare ::nullptr_t.
-#include_next <stddef.h>
-#include <__nullptr>
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::ptrdiff_t;
-using ::size_t;
-
-#if defined(__CLANG_MAX_ALIGN_T_DEFINED) || defined(_GCC_MAX_ALIGN_T) || \
-    defined(__DEFINED_max_align_t) || defined(__NetBSD__)
-// Re-use the compiler's <stddef.h> max_align_t where possible.
-using ::max_align_t;
-#else
-typedef long double max_align_t;
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER > 14
-namespace std  // purposefully not versioned
-{
-enum class byte : unsigned char {};
-
-constexpr byte  operator| (byte  __lhs, byte __rhs) noexcept
-{
-    return static_cast<byte>(
-      static_cast<unsigned char>(
-         static_cast<unsigned int>(__lhs) | static_cast<unsigned int>(__rhs)
-    ));
-}
-
-constexpr byte& operator|=(byte& __lhs, byte __rhs) noexcept
-{ return __lhs = __lhs | __rhs; }
-
-constexpr byte  operator& (byte  __lhs, byte __rhs) noexcept
-{
-    return static_cast<byte>(
-      static_cast<unsigned char>(
-         static_cast<unsigned int>(__lhs) & static_cast<unsigned int>(__rhs)
-    ));
-}
-
-constexpr byte& operator&=(byte& __lhs, byte __rhs) noexcept
-{ return __lhs = __lhs & __rhs; }
-
-constexpr byte  operator^ (byte  __lhs, byte __rhs) noexcept
-{
-    return static_cast<byte>(
-      static_cast<unsigned char>(
-         static_cast<unsigned int>(__lhs) ^ static_cast<unsigned int>(__rhs)
-    ));
-}
-
-constexpr byte& operator^=(byte& __lhs, byte __rhs) noexcept
-{ return __lhs = __lhs ^ __rhs; }
-
-constexpr byte  operator~ (byte __b) noexcept
-{
-    return static_cast<byte>(
-      static_cast<unsigned char>(
-        ~static_cast<unsigned int>(__b)
-    ));
-}
-
-}
-
-#include <type_traits>  // rest of byte
-#endif
-
-#endif  // _LIBCPP_CSTDDEF
diff --git a/lib/libcxx/include/cstdint b/lib/libcxx/include/cstdint
deleted file mode 100644
index 7a187d3ebf2..00000000000
--- a/lib/libcxx/include/cstdint
+++ /dev/null
@@ -1,191 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cstdint ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CSTDINT
-#define _LIBCPP_CSTDINT
-
-/*
-    cstdint synopsis
-
-Macros:
-
-    INT8_MIN
-    INT16_MIN
-    INT32_MIN
-    INT64_MIN
-
-    INT8_MAX
-    INT16_MAX
-    INT32_MAX
-    INT64_MAX
-
-    UINT8_MAX
-    UINT16_MAX
-    UINT32_MAX
-    UINT64_MAX
-
-    INT_LEAST8_MIN
-    INT_LEAST16_MIN
-    INT_LEAST32_MIN
-    INT_LEAST64_MIN
-
-    INT_LEAST8_MAX
-    INT_LEAST16_MAX
-    INT_LEAST32_MAX
-    INT_LEAST64_MAX
-
-    UINT_LEAST8_MAX
-    UINT_LEAST16_MAX
-    UINT_LEAST32_MAX
-    UINT_LEAST64_MAX
-
-    INT_FAST8_MIN
-    INT_FAST16_MIN
-    INT_FAST32_MIN
-    INT_FAST64_MIN
-
-    INT_FAST8_MAX
-    INT_FAST16_MAX
-    INT_FAST32_MAX
-    INT_FAST64_MAX
-
-    UINT_FAST8_MAX
-    UINT_FAST16_MAX
-    UINT_FAST32_MAX
-    UINT_FAST64_MAX
-
-    INTPTR_MIN
-    INTPTR_MAX
-    UINTPTR_MAX
-
-    INTMAX_MIN
-    INTMAX_MAX
-
-    UINTMAX_MAX
-
-    PTRDIFF_MIN
-    PTRDIFF_MAX
-
-    SIG_ATOMIC_MIN
-    SIG_ATOMIC_MAX
-
-    SIZE_MAX
-
-    WCHAR_MIN
-    WCHAR_MAX
-
-    WINT_MIN
-    WINT_MAX
-
-    INT8_C(value)
-    INT16_C(value)
-    INT32_C(value)
-    INT64_C(value)
-
-    UINT8_C(value)
-    UINT16_C(value)
-    UINT32_C(value)
-    UINT64_C(value)
-
-    INTMAX_C(value)
-    UINTMAX_C(value)
-
-namespace std
-{
-
-Types:
-
-    int8_t
-    int16_t
-    int32_t
-    int64_t
-
-    uint8_t
-    uint16_t
-    uint32_t
-    uint64_t
-
-    int_least8_t
-    int_least16_t
-    int_least32_t
-    int_least64_t
-
-    uint_least8_t
-    uint_least16_t
-    uint_least32_t
-    uint_least64_t
-
-    int_fast8_t
-    int_fast16_t
-    int_fast32_t
-    int_fast64_t
-
-    uint_fast8_t
-    uint_fast16_t
-    uint_fast32_t
-    uint_fast64_t
-
-    intptr_t
-    uintptr_t
-
-    intmax_t
-    uintmax_t
-
-}  // std
-*/
-
-#include <__config>
-#include <stdint.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using::int8_t;
-using::int16_t;
-using::int32_t;
-using::int64_t;
-
-using::uint8_t;
-using::uint16_t;
-using::uint32_t;
-using::uint64_t;
-
-using::int_least8_t;
-using::int_least16_t;
-using::int_least32_t;
-using::int_least64_t;
-
-using::uint_least8_t;
-using::uint_least16_t;
-using::uint_least32_t;
-using::uint_least64_t;
-
-using::int_fast8_t;
-using::int_fast16_t;
-using::int_fast32_t;
-using::int_fast64_t;
-
-using::uint_fast8_t;
-using::uint_fast16_t;
-using::uint_fast32_t;
-using::uint_fast64_t;
-
-using::intptr_t;
-using::uintptr_t;
-
-using::intmax_t;
-using::uintmax_t;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CSTDINT
diff --git a/lib/libcxx/include/cstdio b/lib/libcxx/include/cstdio
deleted file mode 100644
index 48643c5eb4b..00000000000
--- a/lib/libcxx/include/cstdio
+++ /dev/null
@@ -1,172 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- cstdio ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CSTDIO
-#define _LIBCPP_CSTDIO
-
-/*
-    cstdio synopsis
-
-Macros:
-
-    BUFSIZ
-    EOF
-    FILENAME_MAX
-    FOPEN_MAX
-    L_tmpnam
-    NULL
-    SEEK_CUR
-    SEEK_END
-    SEEK_SET
-    TMP_MAX
-    _IOFBF
-    _IOLBF
-    _IONBF
-    stderr
-    stdin
-    stdout
-
-namespace std
-{
-
-Types:
-
-FILE
-fpos_t
-size_t
-
-int remove(const char* filename);
-int rename(const char* old, const char* new);
-FILE* tmpfile(void);
-char* tmpnam(char* s);
-int fclose(FILE* stream);
-int fflush(FILE* stream);
-FILE* fopen(const char* restrict filename, const char* restrict mode);
-FILE* freopen(const char* restrict filename, const char * restrict mode,
-              FILE * restrict stream);
-void setbuf(FILE* restrict stream, char* restrict buf);
-int setvbuf(FILE* restrict stream, char* restrict buf, int mode, size_t size);
-int fprintf(FILE* restrict stream, const char* restrict format, ...);
-int fscanf(FILE* restrict stream, const char * restrict format, ...);
-int printf(const char* restrict format, ...);
-int scanf(const char* restrict format, ...);
-int snprintf(char* restrict s, size_t n, const char* restrict format, ...);    // C99
-int sprintf(char* restrict s, const char* restrict format, ...);
-int sscanf(const char* restrict s, const char* restrict format, ...);
-int vfprintf(FILE* restrict stream, const char* restrict format, va_list arg);
-int vfscanf(FILE* restrict stream, const char* restrict format, va_list arg);  // C99
-int vprintf(const char* restrict format, va_list arg);
-int vscanf(const char* restrict format, va_list arg);                          // C99
-int vsnprintf(char* restrict s, size_t n, const char* restrict format,         // C99
-              va_list arg);
-int vsprintf(char* restrict s, const char* restrict format, va_list arg);
-int vsscanf(const char* restrict s, const char* restrict format, va_list arg); // C99
-int fgetc(FILE* stream);
-char* fgets(char* restrict s, int n, FILE* restrict stream);
-int fputc(int c, FILE* stream);
-int fputs(const char* restrict s, FILE* restrict stream);
-int getc(FILE* stream);
-int getchar(void);
-char* gets(char* s);  // removed in C++14
-int putc(int c, FILE* stream);
-int putchar(int c);
-int puts(const char* s);
-int ungetc(int c, FILE* stream);
-size_t fread(void* restrict ptr, size_t size, size_t nmemb,
-             FILE* restrict stream);
-size_t fwrite(const void* restrict ptr, size_t size, size_t nmemb,
-              FILE* restrict stream);
-int fgetpos(FILE* restrict stream, fpos_t* restrict pos);
-int fseek(FILE* stream, long offset, int whence);
-int fsetpos(FILE*stream, const fpos_t* pos);
-long ftell(FILE* stream);
-void rewind(FILE* stream);
-void clearerr(FILE* stream);
-int feof(FILE* stream);
-int ferror(FILE* stream);
-void perror(const char* s);
-
-}  // std
-*/
-
-#include <__config>
-#include <stdio.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::FILE;
-using ::fpos_t;
-using ::size_t;
-
-using ::fclose;
-using ::fflush;
-using ::setbuf;
-using ::setvbuf;
-using ::fprintf;
-using ::fscanf;
-using ::snprintf;
-using ::sprintf;
-using ::sscanf;
-using ::vfprintf;
-using ::vfscanf;
-using ::vsscanf;
-using ::vsnprintf;
-using ::vsprintf;
-using ::fgetc;
-using ::fgets;
-using ::fputc;
-using ::fputs;
-using ::getc;
-using ::putc;
-using ::ungetc;
-using ::fread;
-using ::fwrite;
-using ::fgetpos;
-using ::fseek;
-using ::fsetpos;
-using ::ftell;
-using ::rewind;
-using ::clearerr;
-using ::feof;
-using ::ferror;
-using ::perror;
-
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-using ::fopen;
-using ::freopen;
-using ::remove;
-using ::rename;
-using ::tmpfile;
-using ::tmpnam;
-#endif
-
-#ifndef _LIBCPP_HAS_NO_STDIN
-using ::getchar;
-#if _LIBCPP_STD_VER <= 11 && !defined(_LIBCPP_MSVCRT) && !defined(__OpenBSD__)
-using ::gets;
-#endif
-using ::scanf;
-using ::vscanf;
-#endif
-
-#ifndef _LIBCPP_HAS_NO_STDOUT
-using ::printf;
-using ::putchar;
-using ::puts;
-using ::vprintf;
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CSTDIO
diff --git a/lib/libcxx/include/cstdlib b/lib/libcxx/include/cstdlib
deleted file mode 100644
index 00c604e6762..00000000000
--- a/lib/libcxx/include/cstdlib
+++ /dev/null
@@ -1,164 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cstdlib ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CSTDLIB
-#define _LIBCPP_CSTDLIB
-
-/*
-    cstdlib synopsis
-
-Macros:
-
-    EXIT_FAILURE
-    EXIT_SUCCESS
-    MB_CUR_MAX
-    NULL
-    RAND_MAX
-
-namespace std
-{
-
-Types:
-
-    size_t
-    div_t
-    ldiv_t
-    lldiv_t                                                               // C99
-
-double    atof (const char* nptr);
-int       atoi (const char* nptr);
-long      atol (const char* nptr);
-long long atoll(const char* nptr);                                        // C99
-double             strtod  (const char* restrict nptr, char** restrict endptr);
-float              strtof  (const char* restrict nptr, char** restrict endptr); // C99
-long double        strtold (const char* restrict nptr, char** restrict endptr); // C99
-long               strtol  (const char* restrict nptr, char** restrict endptr, int base);
-long long          strtoll (const char* restrict nptr, char** restrict endptr, int base); // C99
-unsigned long      strtoul (const char* restrict nptr, char** restrict endptr, int base);
-unsigned long long strtoull(const char* restrict nptr, char** restrict endptr, int base); // C99
-int rand(void);
-void srand(unsigned int seed);
-void* calloc(size_t nmemb, size_t size);
-void free(void* ptr);
-void* malloc(size_t size);
-void* realloc(void* ptr, size_t size);
-void abort(void);
-int atexit(void (*func)(void));
-void exit(int status);
-void _Exit(int status);
-char* getenv(const char* name);
-int system(const char* string);
-void* bsearch(const void* key, const void* base, size_t nmemb, size_t size,
-              int (*compar)(const void *, const void *));
-void qsort(void* base, size_t nmemb, size_t size,
-           int (*compar)(const void *, const void *));
-int         abs(      int j);
-long        abs(     long j);
-long long   abs(long long j);                                             // C++0X
-long       labs(     long j);
-long long llabs(long long j);                                             // C99
-div_t     div(      int numer,       int denom);
-ldiv_t    div(     long numer,      long denom);
-lldiv_t   div(long long numer, long long denom);                          // C++0X
-ldiv_t   ldiv(     long numer,      long denom);
-lldiv_t lldiv(long long numer, long long denom);                          // C99
-int mblen(const char* s, size_t n);
-int mbtowc(wchar_t* restrict pwc, const char* restrict s, size_t n);
-int wctomb(char* s, wchar_t wchar);
-size_t mbstowcs(wchar_t* restrict pwcs, const char* restrict s, size_t n);
-size_t wcstombs(char* restrict s, const wchar_t* restrict pwcs, size_t n);
-int at_quick_exit(void (*func)(void))                                     // C++11
-void quick_exit(int status);                                              // C++11
-void *aligned_alloc(size_t alignment, size_t size);                       // C11
-
-}  // std
-
-*/
-
-#include <__config>
-#include <stdlib.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef __GNUC__
-#define _LIBCPP_UNREACHABLE() __builtin_unreachable()
-#else
-#define _LIBCPP_UNREACHABLE() _VSTD::abort()
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::size_t;
-using ::div_t;
-using ::ldiv_t;
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-using ::lldiv_t;
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-using ::atof;
-using ::atoi;
-using ::atol;
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-using ::atoll;
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-using ::strtod;
-using ::strtof;
-using ::strtold;
-using ::strtol;
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-using ::strtoll;
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-using ::strtoul;
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-using ::strtoull;
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-using ::rand;
-using ::srand;
-using ::calloc;
-using ::free;
-using ::malloc;
-using ::realloc;
-using ::abort;
-using ::atexit;
-using ::exit;
-using ::_Exit;
-#ifndef _LIBCPP_WINDOWS_STORE_APP
-using ::getenv;
-using ::system;
-#endif
-using ::bsearch;
-using ::qsort;
-using ::abs;
-using ::labs;
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-using ::llabs;
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-using ::div;
-using ::ldiv;
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-using ::lldiv;
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-using ::mblen;
-using ::mbtowc;
-using ::wctomb;
-using ::mbstowcs;
-using ::wcstombs;
-#if !defined(_LIBCPP_CXX03_LANG) && defined(_LIBCPP_HAS_QUICK_EXIT)
-using ::at_quick_exit;
-using ::quick_exit;
-#endif
-#if _LIBCPP_STD_VER > 14 && defined(_LIBCPP_HAS_C11_FEATURES)
-using ::aligned_alloc;
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CSTDLIB
diff --git a/lib/libcxx/include/cstring b/lib/libcxx/include/cstring
deleted file mode 100644
index d550695caa4..00000000000
--- a/lib/libcxx/include/cstring
+++ /dev/null
@@ -1,97 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cstring ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CSTRING
-#define _LIBCPP_CSTRING
-
-/*
-    cstring synopsis
-
-Macros:
-
-    NULL
-
-namespace std
-{
-
-Types:
-
-    size_t
-
-void* memcpy(void* restrict s1, const void* restrict s2, size_t n);
-void* memmove(void* s1, const void* s2, size_t n);
-char* strcpy (char* restrict s1, const char* restrict s2);
-char* strncpy(char* restrict s1, const char* restrict s2, size_t n);
-char* strcat (char* restrict s1, const char* restrict s2);
-char* strncat(char* restrict s1, const char* restrict s2, size_t n);
-int memcmp(const void* s1, const void* s2, size_t n);
-int strcmp (const char* s1, const char* s2);
-int strncmp(const char* s1, const char* s2, size_t n);
-int strcoll(const char* s1, const char* s2);
-size_t strxfrm(char* restrict s1, const char* restrict s2, size_t n);
-const void* memchr(const void* s, int c, size_t n);
-      void* memchr(      void* s, int c, size_t n);
-const char* strchr(const char* s, int c);
-      char* strchr(      char* s, int c);
-size_t strcspn(const char* s1, const char* s2);
-const char* strpbrk(const char* s1, const char* s2);
-      char* strpbrk(      char* s1, const char* s2);
-const char* strrchr(const char* s, int c);
-      char* strrchr(      char* s, int c);
-size_t strspn(const char* s1, const char* s2);
-const char* strstr(const char* s1, const char* s2);
-      char* strstr(      char* s1, const char* s2);
-char* strtok(char* restrict s1, const char* restrict s2);
-void* memset(void* s, int c, size_t n);
-char* strerror(int errnum);
-size_t strlen(const char* s);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <string.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::size_t;
-using ::memcpy;
-using ::memmove;
-using ::strcpy;
-using ::strncpy;
-using ::strcat;
-using ::strncat;
-using ::memcmp;
-using ::strcmp;
-using ::strncmp;
-using ::strcoll;
-using ::strxfrm;
-using ::memchr;
-using ::strchr;
-using ::strcspn;
-using ::strpbrk;
-using ::strrchr;
-using ::strspn;
-using ::strstr;
-#ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
-using ::strtok;
-#endif
-using ::memset;
-using ::strerror;
-using ::strlen;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CSTRING
diff --git a/lib/libcxx/include/ctgmath b/lib/libcxx/include/ctgmath
deleted file mode 100644
index 535eb7dccd1..00000000000
--- a/lib/libcxx/include/ctgmath
+++ /dev/null
@@ -1,29 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- ctgmath -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CTGMATH
-#define _LIBCPP_CTGMATH
-
-/*
-    ctgmath synopsis
-
-#include <ccomplex>
-#include <cmath>
-
-*/
-
-#include <ccomplex>
-#include <cmath>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#endif  // _LIBCPP_CTGMATH
diff --git a/lib/libcxx/include/ctime b/lib/libcxx/include/ctime
deleted file mode 100644
index 8264fe33b96..00000000000
--- a/lib/libcxx/include/ctime
+++ /dev/null
@@ -1,82 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- ctime -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CTIME
-#define _LIBCPP_CTIME
-
-/*
-    ctime synopsis
-
-Macros:
-
-    NULL
-    CLOCKS_PER_SEC
-    TIME_UTC // C++17
-    
-namespace std
-{
-
-Types:
-
-    clock_t
-    size_t
-    time_t
-    tm
-    timespec // C++17
-    
-clock_t clock();
-double difftime(time_t time1, time_t time0);
-time_t mktime(tm* timeptr);
-time_t time(time_t* timer);
-char* asctime(const tm* timeptr);
-char* ctime(const time_t* timer);
-tm*    gmtime(const time_t* timer);
-tm* localtime(const time_t* timer);
-size_t strftime(char* restrict s, size_t maxsize, const char* restrict format,
-                const tm* restrict timeptr);
-int timespec_get( struct timespec *ts, int base); // C++17
-}  // std
-
-*/
-
-#include <__config>
-#include <time.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::clock_t;
-using ::size_t;
-using ::time_t;
-using ::tm;
-#if _LIBCPP_STD_VER > 14 && defined(_LIBCPP_HAS_C11_FEATURES)
-using ::timespec;
-#endif
-using ::clock;
-using ::difftime;
-using ::mktime;
-using ::time;
-#ifndef _LIBCPP_HAS_NO_THREAD_UNSAFE_C_FUNCTIONS
-using ::asctime;
-using ::ctime;
-using ::gmtime;
-using ::localtime;
-#endif
-using ::strftime;
-#if _LIBCPP_STD_VER > 14 && defined(_LIBCPP_HAS_TIMESPEC_GET)
-using ::timespec_get;
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CTIME
diff --git a/lib/libcxx/include/ctype.h b/lib/libcxx/include/ctype.h
deleted file mode 100644
index e97ff3c4887..00000000000
--- a/lib/libcxx/include/ctype.h
+++ /dev/null
@@ -1,60 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- ctype.h ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CTYPE_H
-#define _LIBCPP_CTYPE_H
-
-/*
-    ctype.h synopsis
-
-int isalnum(int c);
-int isalpha(int c);
-int isblank(int c);  // C99
-int iscntrl(int c);
-int isdigit(int c);
-int isgraph(int c);
-int islower(int c);
-int isprint(int c);
-int ispunct(int c);
-int isspace(int c);
-int isupper(int c);
-int isxdigit(int c);
-int tolower(int c);
-int toupper(int c);
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <ctype.h>
-
-#ifdef __cplusplus
-
-#undef isalnum
-#undef isalpha
-#undef isblank
-#undef iscntrl
-#undef isdigit
-#undef isgraph
-#undef islower
-#undef isprint
-#undef ispunct
-#undef isspace
-#undef isupper
-#undef isxdigit
-#undef tolower
-#undef toupper
-
-#endif
-
-#endif  // _LIBCPP_CTYPE_H
diff --git a/lib/libcxx/include/cwchar b/lib/libcxx/include/cwchar
deleted file mode 100644
index d268e8bbd39..00000000000
--- a/lib/libcxx/include/cwchar
+++ /dev/null
@@ -1,193 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cwchar -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CWCHAR
-#define _LIBCPP_CWCHAR
-
-/*
-    cwchar synopsis
-
-Macros:
-
-    NULL
-    WCHAR_MAX
-    WCHAR_MIN
-    WEOF
-
-namespace std
-{
-
-Types:
-
-    mbstate_t
-    size_t
-    tm
-    wint_t
-
-int fwprintf(FILE* restrict stream, const wchar_t* restrict format, ...);
-int fwscanf(FILE* restrict stream, const wchar_t* restrict format, ...);
-int swprintf(wchar_t* restrict s, size_t n, const wchar_t* restrict format, ...);
-int swscanf(const wchar_t* restrict s, const wchar_t* restrict format, ...);
-int vfwprintf(FILE* restrict stream, const wchar_t* restrict format, va_list arg);
-int vfwscanf(FILE* restrict stream, const wchar_t* restrict format, va_list arg);  // C99
-int vswprintf(wchar_t* restrict s, size_t n, const wchar_t* restrict format, va_list arg);
-int vswscanf(const wchar_t* restrict s, const wchar_t* restrict format, va_list arg);  // C99
-int vwprintf(const wchar_t* restrict format, va_list arg);
-int vwscanf(const wchar_t* restrict format, va_list arg);  // C99
-int wprintf(const wchar_t* restrict format, ...);
-int wscanf(const wchar_t* restrict format, ...);
-wint_t fgetwc(FILE* stream);
-wchar_t* fgetws(wchar_t* restrict s, int n, FILE* restrict stream);
-wint_t fputwc(wchar_t c, FILE* stream);
-int fputws(const wchar_t* restrict s, FILE* restrict stream);
-int fwide(FILE* stream, int mode);
-wint_t getwc(FILE* stream);
-wint_t getwchar();
-wint_t putwc(wchar_t c, FILE* stream);
-wint_t putwchar(wchar_t c);
-wint_t ungetwc(wint_t c, FILE* stream);
-double wcstod(const wchar_t* restrict nptr, wchar_t** restrict endptr);
-float wcstof(const wchar_t* restrict nptr, wchar_t** restrict endptr);         // C99
-long double wcstold(const wchar_t* restrict nptr, wchar_t** restrict endptr);  // C99
-long wcstol(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
-long long wcstoll(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);  // C99
-unsigned long wcstoul(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
-unsigned long long wcstoull(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);  // C99
-wchar_t* wcscpy(wchar_t* restrict s1, const wchar_t* restrict s2);
-wchar_t* wcsncpy(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-wchar_t* wcscat(wchar_t* restrict s1, const wchar_t* restrict s2);
-wchar_t* wcsncat(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-int wcscmp(const wchar_t* s1, const wchar_t* s2);
-int wcscoll(const wchar_t* s1, const wchar_t* s2);
-int wcsncmp(const wchar_t* s1, const wchar_t* s2, size_t n);
-size_t wcsxfrm(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-const wchar_t* wcschr(const wchar_t* s, wchar_t c);
-      wchar_t* wcschr(      wchar_t* s, wchar_t c);
-size_t wcscspn(const wchar_t* s1, const wchar_t* s2);
-size_t wcslen(const wchar_t* s);
-const wchar_t* wcspbrk(const wchar_t* s1, const wchar_t* s2);
-      wchar_t* wcspbrk(      wchar_t* s1, const wchar_t* s2);
-const wchar_t* wcsrchr(const wchar_t* s, wchar_t c);
-      wchar_t* wcsrchr(      wchar_t* s, wchar_t c);
-size_t wcsspn(const wchar_t* s1, const wchar_t* s2);
-const wchar_t* wcsstr(const wchar_t* s1, const wchar_t* s2);
-      wchar_t* wcsstr(      wchar_t* s1, const wchar_t* s2);
-wchar_t* wcstok(wchar_t* restrict s1, const wchar_t* restrict s2, wchar_t** restrict ptr);
-const wchar_t* wmemchr(const wchar_t* s, wchar_t c, size_t n);
-      wchar_t* wmemchr(      wchar_t* s, wchar_t c, size_t n);
-int wmemcmp(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-wchar_t* wmemcpy(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-wchar_t* wmemmove(wchar_t* s1, const wchar_t* s2, size_t n);
-wchar_t* wmemset(wchar_t* s, wchar_t c, size_t n);
-size_t wcsftime(wchar_t* restrict s, size_t maxsize, const wchar_t* restrict format,
-                const tm* restrict timeptr);
-wint_t btowc(int c);
-int wctob(wint_t c);
-int mbsinit(const mbstate_t* ps);
-size_t mbrlen(const char* restrict s, size_t n, mbstate_t* restrict ps);
-size_t mbrtowc(wchar_t* restrict pwc, const char* restrict s, size_t n, mbstate_t* restrict ps);
-size_t wcrtomb(char* restrict s, wchar_t wc, mbstate_t* restrict ps);
-size_t mbsrtowcs(wchar_t* restrict dst, const char** restrict src, size_t len,
-                 mbstate_t* restrict ps);
-size_t wcsrtombs(char* restrict dst, const wchar_t** restrict src, size_t len,
-                 mbstate_t* restrict ps);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <cwctype>
-#include <wchar.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::mbstate_t;
-using ::size_t;
-using ::tm;
-using ::wint_t;
-using ::FILE;
-using ::fwprintf;
-using ::fwscanf;
-using ::swprintf;
-using ::vfwprintf;
-using ::vswprintf;
-using ::swscanf;
-using ::vfwscanf;
-using ::vswscanf;
-using ::fgetwc;
-using ::fgetws;
-using ::fputwc;
-using ::fputws;
-using ::fwide;
-using ::getwc;
-using ::putwc;
-using ::ungetwc;
-using ::wcstod;
-using ::wcstof;
-using ::wcstold;
-using ::wcstol;
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-using ::wcstoll;
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-using ::wcstoul;
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-using ::wcstoull;
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-using ::wcscpy;
-using ::wcsncpy;
-using ::wcscat;
-using ::wcsncat;
-using ::wcscmp;
-using ::wcscoll;
-using ::wcsncmp;
-using ::wcsxfrm;
-using ::wcschr;
-using ::wcspbrk;
-using ::wcsrchr;
-using ::wcsstr;
-using ::wmemchr;
-using ::wcscspn;
-using ::wcslen;
-using ::wcsspn;
-using ::wcstok;
-using ::wmemcmp;
-using ::wmemcpy;
-using ::wmemmove;
-using ::wmemset;
-using ::wcsftime;
-using ::btowc;
-using ::wctob;
-using ::mbsinit;
-using ::mbrlen;
-using ::mbrtowc;
-using ::wcrtomb;
-using ::mbsrtowcs;
-using ::wcsrtombs;
-
-#ifndef _LIBCPP_HAS_NO_STDIN
-using ::getwchar;
-using ::vwscanf;
-using ::wscanf;
-#endif
-
-#ifndef _LIBCPP_HAS_NO_STDOUT
-using ::putwchar;
-using ::vwprintf;
-using ::wprintf;
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CWCHAR
diff --git a/lib/libcxx/include/cwctype b/lib/libcxx/include/cwctype
deleted file mode 100644
index 25b2489edf2..00000000000
--- a/lib/libcxx/include/cwctype
+++ /dev/null
@@ -1,87 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- cwctype ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_CWCTYPE
-#define _LIBCPP_CWCTYPE
-
-/*
-    cwctype synopsis
-
-Macros:
-
-    WEOF
-
-namespace std
-{
-
-Types:
-
-    wint_t
-    wctrans_t
-    wctype_t
-
-int iswalnum(wint_t wc);
-int iswalpha(wint_t wc);
-int iswblank(wint_t wc);  // C99
-int iswcntrl(wint_t wc);
-int iswdigit(wint_t wc);
-int iswgraph(wint_t wc);
-int iswlower(wint_t wc);
-int iswprint(wint_t wc);
-int iswpunct(wint_t wc);
-int iswspace(wint_t wc);
-int iswupper(wint_t wc);
-int iswxdigit(wint_t wc);
-int iswctype(wint_t wc, wctype_t desc);
-wctype_t wctype(const char* property);
-wint_t towlower(wint_t wc);
-wint_t towupper(wint_t wc);
-wint_t towctrans(wint_t wc, wctrans_t desc);
-wctrans_t wctrans(const char* property);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <cctype>
-#include <wctype.h>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-using ::wint_t;
-using ::wctrans_t;
-using ::wctype_t;
-using ::iswalnum;
-using ::iswalpha;
-using ::iswblank;
-using ::iswcntrl;
-using ::iswdigit;
-using ::iswgraph;
-using ::iswlower;
-using ::iswprint;
-using ::iswpunct;
-using ::iswspace;
-using ::iswupper;
-using ::iswxdigit;
-using ::iswctype;
-using ::wctype;
-using ::towlower;
-using ::towupper;
-using ::towctrans;
-using ::wctrans;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_CWCTYPE
diff --git a/lib/libcxx/include/deque b/lib/libcxx/include/deque
deleted file mode 100644
index 6f7d04be52b..00000000000
--- a/lib/libcxx/include/deque
+++ /dev/null
@@ -1,2953 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- deque -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_DEQUE
-#define _LIBCPP_DEQUE
-
-/*
-    deque synopsis
-
-namespace std
-{
-
-template <class T, class Allocator = allocator<T> >
-class deque
-{
-public:
-    // types:
-    typedef T value_type;
-    typedef Allocator allocator_type;
-
-    typedef typename allocator_type::reference       reference;
-    typedef typename allocator_type::const_reference const_reference;
-    typedef implementation-defined                   iterator;
-    typedef implementation-defined                   const_iterator;
-    typedef typename allocator_type::size_type       size_type;
-    typedef typename allocator_type::difference_type difference_type;
-
-    typedef typename allocator_type::pointer         pointer;
-    typedef typename allocator_type::const_pointer   const_pointer;
-    typedef std::reverse_iterator<iterator>          reverse_iterator;
-    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
-
-    // construct/copy/destroy:
-    deque() noexcept(is_nothrow_default_constructible<allocator_type>::value);
-    explicit deque(const allocator_type& a);
-    explicit deque(size_type n);
-    explicit deque(size_type n, const allocator_type& a); // C++14
-    deque(size_type n, const value_type& v);
-    deque(size_type n, const value_type& v, const allocator_type& a);
-    template <class InputIterator>
-        deque(InputIterator f, InputIterator l);
-    template <class InputIterator>
-        deque(InputIterator f, InputIterator l, const allocator_type& a);
-    deque(const deque& c);
-    deque(deque&& c)
-        noexcept(is_nothrow_move_constructible<allocator_type>::value);
-    deque(initializer_list<value_type> il, const Allocator& a = allocator_type());
-    deque(const deque& c, const allocator_type& a);
-    deque(deque&& c, const allocator_type& a);
-    ~deque();
-
-    deque& operator=(const deque& c);
-    deque& operator=(deque&& c)
-        noexcept(
-             allocator_type::propagate_on_container_move_assignment::value &&
-             is_nothrow_move_assignable<allocator_type>::value);
-    deque& operator=(initializer_list<value_type> il);
-
-    template <class InputIterator>
-        void assign(InputIterator f, InputIterator l);
-    void assign(size_type n, const value_type& v);
-    void assign(initializer_list<value_type> il);
-
-    allocator_type get_allocator() const noexcept;
-
-    // iterators:
-
-    iterator       begin() noexcept;
-    const_iterator begin() const noexcept;
-    iterator       end() noexcept;
-    const_iterator end() const noexcept;
-
-    reverse_iterator       rbegin() noexcept;
-    const_reverse_iterator rbegin() const noexcept;
-    reverse_iterator       rend() noexcept;
-    const_reverse_iterator rend() const noexcept;
-
-    const_iterator         cbegin() const noexcept;
-    const_iterator         cend() const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend() const noexcept;
-
-    // capacity:
-    size_type size() const noexcept;
-    size_type max_size() const noexcept;
-    void resize(size_type n);
-    void resize(size_type n, const value_type& v);
-    void shrink_to_fit();
-    bool empty() const noexcept;
-
-    // element access:
-    reference operator[](size_type i);
-    const_reference operator[](size_type i) const;
-    reference at(size_type i);
-    const_reference at(size_type i) const;
-    reference front();
-    const_reference front() const;
-    reference back();
-    const_reference back() const;
-
-    // modifiers:
-    void push_front(const value_type& v);
-    void push_front(value_type&& v);
-    void push_back(const value_type& v);
-    void push_back(value_type&& v);
-    template <class... Args> reference emplace_front(Args&&... args);  // reference in C++17
-    template <class... Args> reference emplace_back(Args&&... args);   // reference in C++17
-    template <class... Args> iterator emplace(const_iterator p, Args&&... args);
-    iterator insert(const_iterator p, const value_type& v);
-    iterator insert(const_iterator p, value_type&& v);
-    iterator insert(const_iterator p, size_type n, const value_type& v);
-    template <class InputIterator>
-        iterator insert(const_iterator p, InputIterator f, InputIterator l);
-    iterator insert(const_iterator p, initializer_list<value_type> il);
-    void pop_front();
-    void pop_back();
-    iterator erase(const_iterator p);
-    iterator erase(const_iterator f, const_iterator l);
-    void swap(deque& c)
-        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
-    void clear() noexcept;
-};
-
-template <class InputIterator, class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
-   deque(InputIterator, InputIterator, Allocator = Allocator())
-   -> deque<typename iterator_traits<InputIterator>::value_type, Allocator>;
-
-template <class T, class Allocator>
-    bool operator==(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
-template <class T, class Allocator>
-    bool operator< (const deque<T,Allocator>& x, const deque<T,Allocator>& y);
-template <class T, class Allocator>
-    bool operator!=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
-template <class T, class Allocator>
-    bool operator> (const deque<T,Allocator>& x, const deque<T,Allocator>& y);
-template <class T, class Allocator>
-    bool operator>=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
-template <class T, class Allocator>
-    bool operator<=(const deque<T,Allocator>& x, const deque<T,Allocator>& y);
-
-// specialized algorithms:
-template <class T, class Allocator>
-    void swap(deque<T,Allocator>& x, deque<T,Allocator>& y)
-         noexcept(noexcept(x.swap(y)));
-
-template <class T, class Allocator, class U>
-    void erase(deque<T, Allocator>& c, const U& value);       // C++20
-template <class T, class Allocator, class Predicate>
-    void erase_if(deque<T, Allocator>& c, Predicate pred);    // C++20
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__split_buffer>
-#include <type_traits>
-#include <initializer_list>
-#include <iterator>
-#include <algorithm>
-#include <stdexcept>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp, class _Allocator> class __deque_base;
-template <class _Tp, class _Allocator = allocator<_Tp> > class _LIBCPP_TEMPLATE_VIS deque;
-
-template <class _ValueType, class _Pointer, class _Reference, class _MapPointer,
-          class _DiffType, _DiffType _BlockSize>
-class _LIBCPP_TEMPLATE_VIS __deque_iterator;
-
-template <class _RAIter,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-copy(_RAIter __f,
-     _RAIter __l,
-     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _OutputIterator>
-_OutputIterator
-copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-     _OutputIterator __r);
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
-
-template <class _RAIter,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-copy_backward(_RAIter __f,
-              _RAIter __l,
-              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _OutputIterator>
-_OutputIterator
-copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-              _OutputIterator __r);
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
-
-template <class _RAIter,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-move(_RAIter __f,
-     _RAIter __l,
-     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _OutputIterator>
-_OutputIterator
-move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-     _OutputIterator __r);
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
-
-template <class _RAIter,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-move_backward(_RAIter __f,
-              _RAIter __l,
-              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _OutputIterator>
-_OutputIterator
-move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-              _OutputIterator __r);
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
-
-template <class _ValueType, class _DiffType>
-struct __deque_block_size {
-  static const _DiffType value = sizeof(_ValueType) < 256 ? 4096 / sizeof(_ValueType) : 16;
-};
-
-template <class _ValueType, class _Pointer, class _Reference, class _MapPointer,
-          class _DiffType, _DiffType _BS =
-#ifdef _LIBCPP_ABI_INCOMPLETE_TYPES_IN_DEQUE
-// Keep template parameter to avoid changing all template declarations thoughout
-// this file.
-                               0
-#else
-                               __deque_block_size<_ValueType, _DiffType>::value
-#endif
-          >
-class _LIBCPP_TEMPLATE_VIS __deque_iterator
-{
-    typedef _MapPointer __map_iterator;
-public:
-    typedef _Pointer  pointer;
-    typedef _DiffType difference_type;
-private:
-    __map_iterator __m_iter_;
-    pointer        __ptr_;
-
-    static const difference_type __block_size;
-public:
-    typedef _ValueType                  value_type;
-    typedef random_access_iterator_tag  iterator_category;
-    typedef _Reference                  reference;
-
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator() _NOEXCEPT
-#if _LIBCPP_STD_VER > 11
-     : __m_iter_(nullptr), __ptr_(nullptr)
-#endif
-     {}
-
-    template <class _Pp, class _Rp, class _MP>
-    _LIBCPP_INLINE_VISIBILITY
-    __deque_iterator(const __deque_iterator<value_type, _Pp, _Rp, _MP, difference_type, _BS>& __it,
-                typename enable_if<is_convertible<_Pp, pointer>::value>::type* = 0) _NOEXCEPT
-        : __m_iter_(__it.__m_iter_), __ptr_(__it.__ptr_) {}
-
-    _LIBCPP_INLINE_VISIBILITY reference operator*() const {return *__ptr_;}
-    _LIBCPP_INLINE_VISIBILITY pointer operator->() const {return __ptr_;}
-
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator++()
-    {
-        if (++__ptr_ - *__m_iter_ == __block_size)
-        {
-            ++__m_iter_;
-            __ptr_ = *__m_iter_;
-        }
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator++(int)
-    {
-        __deque_iterator __tmp = *this;
-        ++(*this);
-        return __tmp;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator--()
-    {
-        if (__ptr_ == *__m_iter_)
-        {
-            --__m_iter_;
-            __ptr_ = *__m_iter_ + __block_size;
-        }
-        --__ptr_;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator--(int)
-    {
-        __deque_iterator __tmp = *this;
-        --(*this);
-        return __tmp;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator+=(difference_type __n)
-    {
-        if (__n != 0)
-        {
-            __n += __ptr_ - *__m_iter_;
-            if (__n > 0)
-            {
-                __m_iter_ += __n / __block_size;
-                __ptr_ = *__m_iter_ + __n % __block_size;
-            }
-            else // (__n < 0)
-            {
-                difference_type __z = __block_size - 1 - __n;
-                __m_iter_ -= __z / __block_size;
-                __ptr_ = *__m_iter_ + (__block_size - 1 - __z % __block_size);
-            }
-        }
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator& operator-=(difference_type __n)
-    {
-        return *this += -__n;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator+(difference_type __n) const
-    {
-        __deque_iterator __t(*this);
-        __t += __n;
-        return __t;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator operator-(difference_type __n) const
-    {
-        __deque_iterator __t(*this);
-        __t -= __n;
-        return __t;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    friend __deque_iterator operator+(difference_type __n, const __deque_iterator& __it)
-        {return __it + __n;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    friend difference_type operator-(const __deque_iterator& __x, const __deque_iterator& __y)
-    {
-        if (__x != __y)
-            return (__x.__m_iter_ - __y.__m_iter_) * __block_size
-                 + (__x.__ptr_ - *__x.__m_iter_)
-                 - (__y.__ptr_ - *__y.__m_iter_);
-        return 0;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY reference operator[](difference_type __n) const
-        {return *(*this + __n);}
-
-    _LIBCPP_INLINE_VISIBILITY friend
-        bool operator==(const __deque_iterator& __x, const __deque_iterator& __y)
-        {return __x.__ptr_ == __y.__ptr_;}
-
-    _LIBCPP_INLINE_VISIBILITY friend
-        bool operator!=(const __deque_iterator& __x, const __deque_iterator& __y)
-        {return !(__x == __y);}
-
-    _LIBCPP_INLINE_VISIBILITY friend
-        bool operator<(const __deque_iterator& __x, const __deque_iterator& __y)
-        {return __x.__m_iter_ < __y.__m_iter_ ||
-               (__x.__m_iter_ == __y.__m_iter_ && __x.__ptr_ < __y.__ptr_);}
-
-    _LIBCPP_INLINE_VISIBILITY friend
-        bool operator>(const __deque_iterator& __x, const __deque_iterator& __y)
-        {return __y < __x;}
-
-    _LIBCPP_INLINE_VISIBILITY friend
-        bool operator<=(const __deque_iterator& __x, const __deque_iterator& __y)
-        {return !(__y < __x);}
-
-    _LIBCPP_INLINE_VISIBILITY friend
-        bool operator>=(const __deque_iterator& __x, const __deque_iterator& __y)
-        {return !(__x < __y);}
-
-private:
-    _LIBCPP_INLINE_VISIBILITY __deque_iterator(__map_iterator __m, pointer __p) _NOEXCEPT
-        : __m_iter_(__m), __ptr_(__p) {}
-
-    template <class _Tp, class _Ap> friend class __deque_base;
-    template <class _Tp, class _Ap> friend class _LIBCPP_TEMPLATE_VIS deque;
-    template <class _Vp, class _Pp, class _Rp, class _MP, class _Dp, _Dp>
-        friend class _LIBCPP_TEMPLATE_VIS __deque_iterator;
-
-    template <class _RAIter,
-              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-    friend
-    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-    copy(_RAIter __f,
-         _RAIter __l,
-         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-         typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
-
-    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-              class _OutputIterator>
-    friend
-    _OutputIterator
-    copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-         _OutputIterator __r);
-
-    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-    friend
-    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-    copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
-
-    template <class _RAIter,
-              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-    friend
-    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-    copy_backward(_RAIter __f,
-                  _RAIter __l,
-                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-                  typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
-
-    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-              class _OutputIterator>
-    friend
-    _OutputIterator
-    copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-                  _OutputIterator __r);
-
-    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-    friend
-    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-    copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
-
-    template <class _RAIter,
-              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-    friend
-    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-    move(_RAIter __f,
-         _RAIter __l,
-         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-         typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
-
-    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-              class _OutputIterator>
-    friend
-    _OutputIterator
-    move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-         _OutputIterator __r);
-
-    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-    friend
-    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-    move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-         __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-         __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
-
-    template <class _RAIter,
-              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-    friend
-    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-    move_backward(_RAIter __f,
-                  _RAIter __l,
-                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-                  typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*);
-
-    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-              class _OutputIterator>
-    friend
-    _OutputIterator
-    move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-                  _OutputIterator __r);
-
-    template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-              class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-    friend
-    __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-    move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-                  __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-                  __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r);
-};
-
-template <class _ValueType, class _Pointer, class _Reference, class _MapPointer,
-          class _DiffType, _DiffType _BlockSize>
-const _DiffType __deque_iterator<_ValueType, _Pointer, _Reference, _MapPointer,
-                                 _DiffType, _BlockSize>::__block_size =
-    __deque_block_size<_ValueType, _DiffType>::value;
-
-// copy
-
-template <class _RAIter,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-copy(_RAIter __f,
-     _RAIter __l,
-     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
-{
-    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
-    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
-    const difference_type __block_size = __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::__block_size;
-    while (__f != __l)
-    {
-        pointer __rb = __r.__ptr_;
-        pointer __re = *__r.__m_iter_ + __block_size;
-        difference_type __bs = __re - __rb;
-        difference_type __n = __l - __f;
-        _RAIter __m = __l;
-        if (__n > __bs)
-        {
-            __n = __bs;
-            __m = __f + __n;
-        }
-        _VSTD::copy(__f, __m, __rb);
-        __f = __m;
-        __r += __n;
-    }
-    return __r;
-}
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _OutputIterator>
-_OutputIterator
-copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-     _OutputIterator __r)
-{
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
-    const difference_type __block_size = __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::__block_size;
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        pointer __fb = __f.__ptr_;
-        pointer __fe = *__f.__m_iter_ + __block_size;
-        difference_type __bs = __fe - __fb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __fe = __fb + __bs;
-        }
-        __r = _VSTD::copy(__fb, __fe, __r);
-        __n -= __bs;
-        __f += __bs;
-    }
-    return __r;
-}
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-copy(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
-{
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
-    const difference_type __block_size = __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::__block_size;
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        pointer __fb = __f.__ptr_;
-        pointer __fe = *__f.__m_iter_ + __block_size;
-        difference_type __bs = __fe - __fb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __fe = __fb + __bs;
-        }
-        __r = _VSTD::copy(__fb, __fe, __r);
-        __n -= __bs;
-        __f += __bs;
-    }
-    return __r;
-}
-
-// copy_backward
-
-template <class _RAIter,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-copy_backward(_RAIter __f,
-              _RAIter __l,
-              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
-{
-    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
-    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
-    while (__f != __l)
-    {
-        __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __rp = _VSTD::prev(__r);
-        pointer __rb = *__rp.__m_iter_;
-        pointer __re = __rp.__ptr_ + 1;
-        difference_type __bs = __re - __rb;
-        difference_type __n = __l - __f;
-        _RAIter __m = __f;
-        if (__n > __bs)
-        {
-            __n = __bs;
-            __m = __l - __n;
-        }
-        _VSTD::copy_backward(__m, __l, __re);
-        __l = __m;
-        __r -= __n;
-    }
-    return __r;
-}
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _OutputIterator>
-_OutputIterator
-copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-              _OutputIterator __r)
-{
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        --__l;
-        pointer __lb = *__l.__m_iter_;
-        pointer __le = __l.__ptr_ + 1;
-        difference_type __bs = __le - __lb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __lb = __le - __bs;
-        }
-        __r = _VSTD::copy_backward(__lb, __le, __r);
-        __n -= __bs;
-        __l -= __bs - 1;
-    }
-    return __r;
-}
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-copy_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
-{
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        --__l;
-        pointer __lb = *__l.__m_iter_;
-        pointer __le = __l.__ptr_ + 1;
-        difference_type __bs = __le - __lb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __lb = __le - __bs;
-        }
-        __r = _VSTD::copy_backward(__lb, __le, __r);
-        __n -= __bs;
-        __l -= __bs - 1;
-    }
-    return __r;
-}
-
-// move
-
-template <class _RAIter,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-move(_RAIter __f,
-     _RAIter __l,
-     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-     typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
-{
-    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
-    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
-    const difference_type __block_size = __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::__block_size;
-    while (__f != __l)
-    {
-        pointer __rb = __r.__ptr_;
-        pointer __re = *__r.__m_iter_ + __block_size;
-        difference_type __bs = __re - __rb;
-        difference_type __n = __l - __f;
-        _RAIter __m = __l;
-        if (__n > __bs)
-        {
-            __n = __bs;
-            __m = __f + __n;
-        }
-        _VSTD::move(__f, __m, __rb);
-        __f = __m;
-        __r += __n;
-    }
-    return __r;
-}
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _OutputIterator>
-_OutputIterator
-move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-     _OutputIterator __r)
-{
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
-    const difference_type __block_size = __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::__block_size;
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        pointer __fb = __f.__ptr_;
-        pointer __fe = *__f.__m_iter_ + __block_size;
-        difference_type __bs = __fe - __fb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __fe = __fb + __bs;
-        }
-        __r = _VSTD::move(__fb, __fe, __r);
-        __n -= __bs;
-        __f += __bs;
-    }
-    return __r;
-}
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-move(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-     __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-     __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
-{
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
-    const difference_type __block_size = __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::__block_size;
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        pointer __fb = __f.__ptr_;
-        pointer __fe = *__f.__m_iter_ + __block_size;
-        difference_type __bs = __fe - __fb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __fe = __fb + __bs;
-        }
-        __r = _VSTD::move(__fb, __fe, __r);
-        __n -= __bs;
-        __f += __bs;
-    }
-    return __r;
-}
-
-// move_backward
-
-template <class _RAIter,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-move_backward(_RAIter __f,
-              _RAIter __l,
-              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r,
-              typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
-{
-    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::difference_type difference_type;
-    typedef typename __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>::pointer pointer;
-    while (__f != __l)
-    {
-        __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __rp = _VSTD::prev(__r);
-        pointer __rb = *__rp.__m_iter_;
-        pointer __re = __rp.__ptr_ + 1;
-        difference_type __bs = __re - __rb;
-        difference_type __n = __l - __f;
-        _RAIter __m = __f;
-        if (__n > __bs)
-        {
-            __n = __bs;
-            __m = __l - __n;
-        }
-        _VSTD::move_backward(__m, __l, __re);
-        __l = __m;
-        __r -= __n;
-    }
-    return __r;
-}
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _OutputIterator>
-_OutputIterator
-move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-              _OutputIterator __r)
-{
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        --__l;
-        pointer __lb = *__l.__m_iter_;
-        pointer __le = __l.__ptr_ + 1;
-        difference_type __bs = __le - __lb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __lb = __le - __bs;
-        }
-        __r = _VSTD::move_backward(__lb, __le, __r);
-        __n -= __bs;
-        __l -= __bs - 1;
-    }
-    return __r;
-}
-
-template <class _V1, class _P1, class _R1, class _M1, class _D1, _D1 _B1,
-          class _V2, class _P2, class _R2, class _M2, class _D2, _D2 _B2>
-__deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2>
-move_backward(__deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __f,
-              __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1> __l,
-              __deque_iterator<_V2, _P2, _R2, _M2, _D2, _B2> __r)
-{
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::difference_type difference_type;
-    typedef typename __deque_iterator<_V1, _P1, _R1, _M1, _D1, _B1>::pointer pointer;
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        --__l;
-        pointer __lb = *__l.__m_iter_;
-        pointer __le = __l.__ptr_ + 1;
-        difference_type __bs = __le - __lb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __lb = __le - __bs;
-        }
-        __r = _VSTD::move_backward(__lb, __le, __r);
-        __n -= __bs;
-        __l -= __bs - 1;
-    }
-    return __r;
-}
-
-template <bool>
-class __deque_base_common
-{
-protected:
-    _LIBCPP_NORETURN void __throw_length_error() const;
-    _LIBCPP_NORETURN void __throw_out_of_range() const;
-};
-
-template <bool __b>
-void
-__deque_base_common<__b>::__throw_length_error() const
-{
-    _VSTD::__throw_length_error("deque");
-}
-
-template <bool __b>
-void
-__deque_base_common<__b>::__throw_out_of_range() const
-{
-    _VSTD::__throw_out_of_range("deque");
-}
-
-template <class _Tp, class _Allocator>
-class __deque_base
-    : protected __deque_base_common<true>
-{
-    __deque_base(const __deque_base& __c);
-    __deque_base& operator=(const __deque_base& __c);
-public:
-    typedef _Allocator                               allocator_type;
-    typedef allocator_traits<allocator_type>         __alloc_traits;
-    typedef typename __alloc_traits::size_type       size_type;
-protected:
-    typedef _Tp                                      value_type;
-    typedef value_type&                              reference;
-    typedef const value_type&                        const_reference;
-    typedef typename __alloc_traits::difference_type difference_type;
-    typedef typename __alloc_traits::pointer         pointer;
-    typedef typename __alloc_traits::const_pointer   const_pointer;
-
-    static const difference_type __block_size;
-
-    typedef typename __rebind_alloc_helper<__alloc_traits, pointer>::type __pointer_allocator;
-    typedef allocator_traits<__pointer_allocator>        __map_traits;
-    typedef typename __map_traits::pointer               __map_pointer;
-    typedef typename __rebind_alloc_helper<__alloc_traits, const_pointer>::type __const_pointer_allocator;
-    typedef typename allocator_traits<__const_pointer_allocator>::const_pointer __map_const_pointer;
-    typedef __split_buffer<pointer, __pointer_allocator> __map;
-
-    typedef __deque_iterator<value_type, pointer, reference, __map_pointer,
-                             difference_type>    iterator;
-    typedef __deque_iterator<value_type, const_pointer, const_reference, __map_const_pointer,
-                             difference_type>    const_iterator;
-
-protected:
-    __map __map_;
-    size_type __start_;
-    __compressed_pair<size_type, allocator_type> __size_;
-
-    iterator       begin() _NOEXCEPT;
-    const_iterator begin() const _NOEXCEPT;
-    iterator       end() _NOEXCEPT;
-    const_iterator end() const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY size_type&            size()          {return __size_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-    const size_type& size() const _NOEXCEPT {return __size_.first();}
-    _LIBCPP_INLINE_VISIBILITY allocator_type&       __alloc()       {return __size_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const allocator_type& __alloc() const _NOEXCEPT {return __size_.second();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __deque_base()
-        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __deque_base(const allocator_type& __a);
-public:
-    ~__deque_base();
-
-#ifndef _LIBCPP_CXX03_LANG
-    __deque_base(__deque_base&& __c)
-        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
-    __deque_base(__deque_base&& __c, const allocator_type& __a);
-#endif  // _LIBCPP_CXX03_LANG
-
-    void swap(__deque_base& __c)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT;
-#else
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
-                    __is_nothrow_swappable<allocator_type>::value);
-#endif
-protected:
-    void clear() _NOEXCEPT;
-
-    bool __invariants() const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign(__deque_base& __c)
-        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
-                   is_nothrow_move_assignable<allocator_type>::value)
-    {
-        __map_ = _VSTD::move(__c.__map_);
-        __start_ = __c.__start_;
-        size() = __c.size();
-        __move_assign_alloc(__c);
-        __c.__start_ = __c.size() = 0;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__deque_base& __c)
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_move_assignment::value ||
-                   is_nothrow_move_assignable<allocator_type>::value)
-        {__move_assign_alloc(__c, integral_constant<bool,
-                      __alloc_traits::propagate_on_container_move_assignment::value>());}
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__deque_base& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-        {
-            __alloc() = _VSTD::move(__c.__alloc());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__deque_base&, false_type) _NOEXCEPT
-        {}
-};
-
-template <class _Tp, class _Allocator>
-const typename __deque_base<_Tp, _Allocator>::difference_type
-    __deque_base<_Tp, _Allocator>::__block_size =
-        __deque_block_size<value_type, difference_type>::value;
-
-template <class _Tp, class _Allocator>
-bool
-__deque_base<_Tp, _Allocator>::__invariants() const
-{
-    if (!__map_.__invariants())
-        return false;
-    if (__map_.size() >= size_type(-1) / __block_size)
-        return false;
-    for (typename __map::const_iterator __i = __map_.begin(), __e = __map_.end();
-         __i != __e; ++__i)
-        if (*__i == nullptr)
-            return false;
-    if (__map_.size() != 0)
-    {
-        if (size() >= __map_.size() * __block_size)
-            return false;
-        if (__start_ >= __map_.size() * __block_size - size())
-            return false;
-    }
-    else
-    {
-        if (size() != 0)
-            return false;
-        if (__start_ != 0)
-            return false;
-    }
-    return true;
-}
-
-template <class _Tp, class _Allocator>
-typename __deque_base<_Tp, _Allocator>::iterator
-__deque_base<_Tp, _Allocator>::begin() _NOEXCEPT
-{
-    __map_pointer __mp = __map_.begin() + __start_ / __block_size;
-    return iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
-}
-
-template <class _Tp, class _Allocator>
-typename __deque_base<_Tp, _Allocator>::const_iterator
-__deque_base<_Tp, _Allocator>::begin() const _NOEXCEPT
-{
-    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __start_ / __block_size);
-    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __start_ % __block_size);
-}
-
-template <class _Tp, class _Allocator>
-typename __deque_base<_Tp, _Allocator>::iterator
-__deque_base<_Tp, _Allocator>::end() _NOEXCEPT
-{
-    size_type __p = size() + __start_;
-    __map_pointer __mp = __map_.begin() + __p / __block_size;
-    return iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
-}
-
-template <class _Tp, class _Allocator>
-typename __deque_base<_Tp, _Allocator>::const_iterator
-__deque_base<_Tp, _Allocator>::end() const _NOEXCEPT
-{
-    size_type __p = size() + __start_;
-    __map_const_pointer __mp = static_cast<__map_const_pointer>(__map_.begin() + __p / __block_size);
-    return const_iterator(__mp, __map_.empty() ? 0 : *__mp + __p % __block_size);
-}
-
-template <class _Tp, class _Allocator>
-inline
-__deque_base<_Tp, _Allocator>::__deque_base()
-    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
-    : __start_(0), __size_(0) {}
-
-template <class _Tp, class _Allocator>
-inline
-__deque_base<_Tp, _Allocator>::__deque_base(const allocator_type& __a)
-    : __map_(__pointer_allocator(__a)), __start_(0), __size_(0, __a) {}
-
-template <class _Tp, class _Allocator>
-__deque_base<_Tp, _Allocator>::~__deque_base()
-{
-    clear();
-    typename __map::iterator __i = __map_.begin();
-    typename __map::iterator __e = __map_.end();
-    for (; __i != __e; ++__i)
-        __alloc_traits::deallocate(__alloc(), *__i, __block_size);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-__deque_base<_Tp, _Allocator>::__deque_base(__deque_base&& __c)
-    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
-    : __map_(_VSTD::move(__c.__map_)),
-      __start_(_VSTD::move(__c.__start_)),
-      __size_(_VSTD::move(__c.__size_))
-{
-    __c.__start_ = 0;
-    __c.size() = 0;
-}
-
-template <class _Tp, class _Allocator>
-__deque_base<_Tp, _Allocator>::__deque_base(__deque_base&& __c, const allocator_type& __a)
-    : __map_(_VSTD::move(__c.__map_), __pointer_allocator(__a)),
-      __start_(_VSTD::move(__c.__start_)),
-      __size_(_VSTD::move(__c.size()), __a)
-{
-    if (__a == __c.__alloc())
-    {
-        __c.__start_ = 0;
-        __c.size() = 0;
-    }
-    else
-    {
-        __map_.clear();
-        __start_ = 0;
-        size() = 0;
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-void
-__deque_base<_Tp, _Allocator>::swap(__deque_base& __c)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT
-#else
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
-                    __is_nothrow_swappable<allocator_type>::value)
-#endif
-{
-    __map_.swap(__c.__map_);
-    _VSTD::swap(__start_, __c.__start_);
-    _VSTD::swap(size(), __c.size());
-    __swap_allocator(__alloc(), __c.__alloc());
-}
-
-template <class _Tp, class _Allocator>
-void
-__deque_base<_Tp, _Allocator>::clear() _NOEXCEPT
-{
-    allocator_type& __a = __alloc();
-    for (iterator __i = begin(), __e = end(); __i != __e; ++__i)
-        __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
-    size() = 0;
-    while (__map_.size() > 2)
-    {
-        __alloc_traits::deallocate(__a, __map_.front(), __block_size);
-        __map_.pop_front();
-    }
-    switch (__map_.size())
-    {
-    case 1:
-        __start_ = __block_size / 2;
-        break;
-    case 2:
-        __start_ = __block_size;
-        break;
-    }
-}
-
-template <class _Tp, class _Allocator /*= allocator<_Tp>*/>
-class _LIBCPP_TEMPLATE_VIS deque
-    : private __deque_base<_Tp, _Allocator>
-{
-public:
-    // types:
-
-    typedef _Tp value_type;
-    typedef _Allocator allocator_type;
-
-    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
-                  "Allocator::value_type must be same type as value_type");
-
-    typedef __deque_base<value_type, allocator_type> __base;
-
-    typedef typename __base::__alloc_traits        __alloc_traits;
-    typedef typename __base::reference             reference;
-    typedef typename __base::const_reference       const_reference;
-    typedef typename __base::iterator              iterator;
-    typedef typename __base::const_iterator        const_iterator;
-    typedef typename __base::size_type             size_type;
-    typedef typename __base::difference_type       difference_type;
-
-    typedef typename __base::pointer               pointer;
-    typedef typename __base::const_pointer         const_pointer;
-    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
-    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
-
-    // construct/copy/destroy:
-    _LIBCPP_INLINE_VISIBILITY
-    deque()
-        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
-        {}
-    _LIBCPP_INLINE_VISIBILITY explicit deque(const allocator_type& __a) : __base(__a) {}
-    explicit deque(size_type __n);
-#if _LIBCPP_STD_VER > 11
-    explicit deque(size_type __n, const _Allocator& __a);
-#endif
-    deque(size_type __n, const value_type& __v);
-    deque(size_type __n, const value_type& __v, const allocator_type& __a);
-    template <class _InputIter>
-        deque(_InputIter __f, _InputIter __l,
-              typename enable_if<__is_input_iterator<_InputIter>::value>::type* = 0);
-    template <class _InputIter>
-        deque(_InputIter __f, _InputIter __l, const allocator_type& __a,
-              typename enable_if<__is_input_iterator<_InputIter>::value>::type* = 0);
-    deque(const deque& __c);
-    deque(const deque& __c, const allocator_type& __a);
-
-    deque& operator=(const deque& __c);
-
-#ifndef _LIBCPP_CXX03_LANG
-    deque(initializer_list<value_type> __il);
-    deque(initializer_list<value_type> __il, const allocator_type& __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    deque& operator=(initializer_list<value_type> __il) {assign(__il); return *this;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    deque(deque&& __c) _NOEXCEPT_(is_nothrow_move_constructible<__base>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    deque(deque&& __c, const allocator_type& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    deque& operator=(deque&& __c)
-        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
-                   is_nothrow_move_assignable<allocator_type>::value);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void assign(initializer_list<value_type> __il) {assign(__il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    template <class _InputIter>
-        void assign(_InputIter __f, _InputIter __l,
-                    typename enable_if<__is_input_iterator<_InputIter>::value &&
-                                      !__is_random_access_iterator<_InputIter>::value>::type* = 0);
-    template <class _RAIter>
-        void assign(_RAIter __f, _RAIter __l,
-                    typename enable_if<__is_random_access_iterator<_RAIter>::value>::type* = 0);
-    void assign(size_type __n, const value_type& __v);
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT;
-
-    // iterators:
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin() _NOEXCEPT       {return __base::begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT {return __base::begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end() _NOEXCEPT         {return __base::end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()   const _NOEXCEPT {return __base::end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator       rbegin() _NOEXCEPT
-        {return       reverse_iterator(__base::end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin() const _NOEXCEPT
-        {return const_reverse_iterator(__base::end());}
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator       rend() _NOEXCEPT
-        {return       reverse_iterator(__base::begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend()   const _NOEXCEPT
-        {return const_reverse_iterator(__base::begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator         cbegin()  const _NOEXCEPT
-        {return __base::begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator         cend()    const _NOEXCEPT
-        {return __base::end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT
-        {return const_reverse_iterator(__base::end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend()   const _NOEXCEPT
-        {return const_reverse_iterator(__base::begin());}
-
-    // capacity:
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT {return __base::size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT
-        {return std::min<size_type>(
-            __alloc_traits::max_size(__base::__alloc()),
-            numeric_limits<difference_type>::max());}
-    void resize(size_type __n);
-    void resize(size_type __n, const value_type& __v);
-    void shrink_to_fit() _NOEXCEPT;
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT {return __base::size() == 0;}
-
-    // element access:
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator[](size_type __i);
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference operator[](size_type __i) const;
-    _LIBCPP_INLINE_VISIBILITY
-    reference at(size_type __i);
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference at(size_type __i) const;
-    _LIBCPP_INLINE_VISIBILITY
-    reference front();
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference front() const;
-    _LIBCPP_INLINE_VISIBILITY
-    reference back();
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference back() const;
-
-    // 23.2.2.3 modifiers:
-    void push_front(const value_type& __v);
-    void push_back(const value_type& __v);
-#ifndef _LIBCPP_CXX03_LANG
-#if _LIBCPP_STD_VER > 14
-    template <class... _Args> reference emplace_front(_Args&&... __args);
-    template <class... _Args> reference emplace_back (_Args&&... __args);
-#else
-    template <class... _Args> void      emplace_front(_Args&&... __args);
-    template <class... _Args> void      emplace_back (_Args&&... __args);
-#endif
-    template <class... _Args> iterator emplace(const_iterator __p, _Args&&... __args);
-
-    void push_front(value_type&& __v);
-    void push_back(value_type&& __v);
-    iterator insert(const_iterator __p, value_type&& __v);
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, initializer_list<value_type> __il)
-        {return insert(__p, __il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-    iterator insert(const_iterator __p, const value_type& __v);
-    iterator insert(const_iterator __p, size_type __n, const value_type& __v);
-    template <class _InputIter>
-        iterator insert(const_iterator __p, _InputIter __f, _InputIter __l,
-                         typename enable_if<__is_input_iterator<_InputIter>::value
-                                         &&!__is_forward_iterator<_InputIter>::value>::type* = 0);
-    template <class _ForwardIterator>
-        iterator insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l,
-                               typename enable_if<__is_forward_iterator<_ForwardIterator>::value
-                                         &&!__is_bidirectional_iterator<_ForwardIterator>::value>::type* = 0);
-    template <class _BiIter>
-        iterator insert(const_iterator __p, _BiIter __f, _BiIter __l,
-                         typename enable_if<__is_bidirectional_iterator<_BiIter>::value>::type* = 0);
-
-    void pop_front();
-    void pop_back();
-    iterator erase(const_iterator __p);
-    iterator erase(const_iterator __f, const_iterator __l);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(deque& __c)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT;
-#else
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
-                   __is_nothrow_swappable<allocator_type>::value);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool __invariants() const {return __base::__invariants();}
-private:
-    typedef typename __base::__map_const_pointer __map_const_pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    static size_type __recommend_blocks(size_type __n)
-    {
-        return __n / __base::__block_size + (__n % __base::__block_size != 0);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    size_type __capacity() const
-    {
-        return __base::__map_.size() == 0 ? 0 : __base::__map_.size() * __base::__block_size - 1;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    size_type __front_spare() const
-    {
-        return __base::__start_;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    size_type __back_spare() const
-    {
-        return __capacity() - (__base::__start_ + __base::size());
-    }
-
-    template <class _InpIter>
-        void __append(_InpIter __f, _InpIter __l,
-                 typename enable_if<__is_input_iterator<_InpIter>::value &&
-                                   !__is_forward_iterator<_InpIter>::value>::type* = 0);
-    template <class _ForIter>
-        void __append(_ForIter __f, _ForIter __l,
-                      typename enable_if<__is_forward_iterator<_ForIter>::value>::type* = 0);
-    void __append(size_type __n);
-    void __append(size_type __n, const value_type& __v);
-    void __erase_to_end(const_iterator __f);
-    void __add_front_capacity();
-    void __add_front_capacity(size_type __n);
-    void __add_back_capacity();
-    void __add_back_capacity(size_type __n);
-    iterator __move_and_check(iterator __f, iterator __l, iterator __r,
-                              const_pointer& __vt);
-    iterator __move_backward_and_check(iterator __f, iterator __l, iterator __r,
-                                       const_pointer& __vt);
-    void __move_construct_and_check(iterator __f, iterator __l,
-                                    iterator __r, const_pointer& __vt);
-    void __move_construct_backward_and_check(iterator __f, iterator __l,
-                                             iterator __r, const_pointer& __vt);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const deque& __c)
-        {__copy_assign_alloc(__c, integral_constant<bool,
-                      __alloc_traits::propagate_on_container_copy_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const deque& __c, true_type)
-        {
-            if (__base::__alloc() != __c.__alloc())
-            {
-                clear();
-                shrink_to_fit();
-            }
-            __base::__alloc() = __c.__alloc();
-            __base::__map_.__alloc() = __c.__map_.__alloc();
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const deque&, false_type)
-        {}
-
-    void __move_assign(deque& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
-    void __move_assign(deque& __c, false_type);
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class _InputIterator,
-         class _Alloc = typename std::allocator<typename iterator_traits<_InputIterator>::value_type>,
-         class = typename enable_if<__is_allocator<_Alloc>::value, void>::type
-         >
-deque(_InputIterator, _InputIterator)
-  -> deque<typename iterator_traits<_InputIterator>::value_type, _Alloc>;
-
-template<class _InputIterator,
-         class _Alloc,
-         class = typename enable_if<__is_allocator<_Alloc>::value, void>::type
-         >
-deque(_InputIterator, _InputIterator, _Alloc)
-  -> deque<typename iterator_traits<_InputIterator>::value_type, _Alloc>;
-#endif
-
-
-template <class _Tp, class _Allocator>
-deque<_Tp, _Allocator>::deque(size_type __n)
-{
-    if (__n > 0)
-        __append(__n);
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp, class _Allocator>
-deque<_Tp, _Allocator>::deque(size_type __n, const _Allocator& __a)
-    : __base(__a)
-{
-    if (__n > 0)
-        __append(__n);
-}
-#endif
-
-template <class _Tp, class _Allocator>
-deque<_Tp, _Allocator>::deque(size_type __n, const value_type& __v)
-{
-    if (__n > 0)
-        __append(__n, __v);
-}
-
-template <class _Tp, class _Allocator>
-deque<_Tp, _Allocator>::deque(size_type __n, const value_type& __v, const allocator_type& __a)
-    : __base(__a)
-{
-    if (__n > 0)
-        __append(__n, __v);
-}
-
-template <class _Tp, class _Allocator>
-template <class _InputIter>
-deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l,
-              typename enable_if<__is_input_iterator<_InputIter>::value>::type*)
-{
-    __append(__f, __l);
-}
-
-template <class _Tp, class _Allocator>
-template <class _InputIter>
-deque<_Tp, _Allocator>::deque(_InputIter __f, _InputIter __l, const allocator_type& __a,
-              typename enable_if<__is_input_iterator<_InputIter>::value>::type*)
-    : __base(__a)
-{
-    __append(__f, __l);
-}
-
-template <class _Tp, class _Allocator>
-deque<_Tp, _Allocator>::deque(const deque& __c)
-    : __base(__alloc_traits::select_on_container_copy_construction(__c.__alloc()))
-{
-    __append(__c.begin(), __c.end());
-}
-
-template <class _Tp, class _Allocator>
-deque<_Tp, _Allocator>::deque(const deque& __c, const allocator_type& __a)
-    : __base(__a)
-{
-    __append(__c.begin(), __c.end());
-}
-
-template <class _Tp, class _Allocator>
-deque<_Tp, _Allocator>&
-deque<_Tp, _Allocator>::operator=(const deque& __c)
-{
-    if (this != &__c)
-    {
-        __copy_assign_alloc(__c);
-        assign(__c.begin(), __c.end());
-    }
-    return *this;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-deque<_Tp, _Allocator>::deque(initializer_list<value_type> __il)
-{
-    __append(__il.begin(), __il.end());
-}
-
-template <class _Tp, class _Allocator>
-deque<_Tp, _Allocator>::deque(initializer_list<value_type> __il, const allocator_type& __a)
-    : __base(__a)
-{
-    __append(__il.begin(), __il.end());
-}
-
-template <class _Tp, class _Allocator>
-inline
-deque<_Tp, _Allocator>::deque(deque&& __c)
-    _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
-    : __base(_VSTD::move(__c))
-{
-}
-
-template <class _Tp, class _Allocator>
-inline
-deque<_Tp, _Allocator>::deque(deque&& __c, const allocator_type& __a)
-    : __base(_VSTD::move(__c), __a)
-{
-    if (__a != __c.__alloc())
-    {
-        typedef move_iterator<iterator> _Ip;
-        assign(_Ip(__c.begin()), _Ip(__c.end()));
-    }
-}
-
-template <class _Tp, class _Allocator>
-inline
-deque<_Tp, _Allocator>&
-deque<_Tp, _Allocator>::operator=(deque&& __c)
-        _NOEXCEPT_(__alloc_traits::propagate_on_container_move_assignment::value &&
-                   is_nothrow_move_assignable<allocator_type>::value)
-{
-    __move_assign(__c, integral_constant<bool,
-          __alloc_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__move_assign(deque& __c, false_type)
-{
-    if (__base::__alloc() != __c.__alloc())
-    {
-        typedef move_iterator<iterator> _Ip;
-        assign(_Ip(__c.begin()), _Ip(__c.end()));
-    }
-    else
-        __move_assign(__c, true_type());
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__move_assign(deque& __c, true_type)
-    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-{
-    clear();
-    shrink_to_fit();
-    __base::__move_assign(__c);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-template <class _InputIter>
-void
-deque<_Tp, _Allocator>::assign(_InputIter __f, _InputIter __l,
-                               typename enable_if<__is_input_iterator<_InputIter>::value &&
-                                                 !__is_random_access_iterator<_InputIter>::value>::type*)
-{
-    iterator __i = __base::begin();
-    iterator __e = __base::end();
-    for (; __f != __l && __i != __e; ++__f, (void) ++__i)
-        *__i = *__f;
-    if (__f != __l)
-        __append(__f, __l);
-    else
-        __erase_to_end(__i);
-}
-
-template <class _Tp, class _Allocator>
-template <class _RAIter>
-void
-deque<_Tp, _Allocator>::assign(_RAIter __f, _RAIter __l,
-                               typename enable_if<__is_random_access_iterator<_RAIter>::value>::type*)
-{
-    if (static_cast<size_type>(__l - __f) > __base::size())
-    {
-        _RAIter __m = __f + __base::size();
-        _VSTD::copy(__f, __m, __base::begin());
-        __append(__m, __l);
-    }
-    else
-        __erase_to_end(_VSTD::copy(__f, __l, __base::begin()));
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::assign(size_type __n, const value_type& __v)
-{
-    if (__n > __base::size())
-    {
-        _VSTD::fill_n(__base::begin(), __base::size(), __v);
-        __n -= __base::size();
-        __append(__n, __v);
-    }
-    else
-        __erase_to_end(_VSTD::fill_n(__base::begin(), __n, __v));
-}
-
-template <class _Tp, class _Allocator>
-inline
-_Allocator
-deque<_Tp, _Allocator>::get_allocator() const _NOEXCEPT
-{
-    return __base::__alloc();
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::resize(size_type __n)
-{
-    if (__n > __base::size())
-        __append(__n - __base::size());
-    else if (__n < __base::size())
-        __erase_to_end(__base::begin() + __n);
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::resize(size_type __n, const value_type& __v)
-{
-    if (__n > __base::size())
-        __append(__n - __base::size(), __v);
-    else if (__n < __base::size())
-        __erase_to_end(__base::begin() + __n);
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
-{
-    allocator_type& __a = __base::__alloc();
-    if (empty())
-    {
-        while (__base::__map_.size() > 0)
-        {
-            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
-            __base::__map_.pop_back();
-        }
-        __base::__start_ = 0;
-    }
-    else
-    {
-        if (__front_spare() >= __base::__block_size)
-        {
-            __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
-            __base::__map_.pop_front();
-            __base::__start_ -= __base::__block_size;
-        }
-        if (__back_spare() >= __base::__block_size)
-        {
-            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
-            __base::__map_.pop_back();
-        }
-    }
-    __base::__map_.shrink_to_fit();
-}
-
-template <class _Tp, class _Allocator>
-inline
-typename deque<_Tp, _Allocator>::reference
-deque<_Tp, _Allocator>::operator[](size_type __i)
-{
-    size_type __p = __base::__start_ + __i;
-    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
-}
-
-template <class _Tp, class _Allocator>
-inline
-typename deque<_Tp, _Allocator>::const_reference
-deque<_Tp, _Allocator>::operator[](size_type __i) const
-{
-    size_type __p = __base::__start_ + __i;
-    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
-}
-
-template <class _Tp, class _Allocator>
-inline
-typename deque<_Tp, _Allocator>::reference
-deque<_Tp, _Allocator>::at(size_type __i)
-{
-    if (__i >= __base::size())
-        __base::__throw_out_of_range();
-    size_type __p = __base::__start_ + __i;
-    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
-}
-
-template <class _Tp, class _Allocator>
-inline
-typename deque<_Tp, _Allocator>::const_reference
-deque<_Tp, _Allocator>::at(size_type __i) const
-{
-    if (__i >= __base::size())
-        __base::__throw_out_of_range();
-    size_type __p = __base::__start_ + __i;
-    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
-}
-
-template <class _Tp, class _Allocator>
-inline
-typename deque<_Tp, _Allocator>::reference
-deque<_Tp, _Allocator>::front()
-{
-    return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
-                                      + __base::__start_ % __base::__block_size);
-}
-
-template <class _Tp, class _Allocator>
-inline
-typename deque<_Tp, _Allocator>::const_reference
-deque<_Tp, _Allocator>::front() const
-{
-    return *(*(__base::__map_.begin() + __base::__start_ / __base::__block_size)
-                                      + __base::__start_ % __base::__block_size);
-}
-
-template <class _Tp, class _Allocator>
-inline
-typename deque<_Tp, _Allocator>::reference
-deque<_Tp, _Allocator>::back()
-{
-    size_type __p = __base::size() + __base::__start_ - 1;
-    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
-}
-
-template <class _Tp, class _Allocator>
-inline
-typename deque<_Tp, _Allocator>::const_reference
-deque<_Tp, _Allocator>::back() const
-{
-    size_type __p = __base::size() + __base::__start_ - 1;
-    return *(*(__base::__map_.begin() + __p / __base::__block_size) + __p % __base::__block_size);
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::push_back(const value_type& __v)
-{
-    allocator_type& __a = __base::__alloc();
-    if (__back_spare() == 0)
-        __add_back_capacity();
-    // __back_spare() >= 1
-    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), __v);
-    ++__base::size();
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::push_front(const value_type& __v)
-{
-    allocator_type& __a = __base::__alloc();
-    if (__front_spare() == 0)
-        __add_front_capacity();
-    // __front_spare() >= 1
-    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), __v);
-    --__base::__start_;
-    ++__base::size();
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::push_back(value_type&& __v)
-{
-    allocator_type& __a = __base::__alloc();
-    if (__back_spare() == 0)
-        __add_back_capacity();
-    // __back_spare() >= 1
-    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::move(__v));
-    ++__base::size();
-}
-
-template <class _Tp, class _Allocator>
-template <class... _Args>
-#if _LIBCPP_STD_VER > 14
-typename deque<_Tp, _Allocator>::reference
-#else
-void
-#endif
-deque<_Tp, _Allocator>::emplace_back(_Args&&... __args)
-{
-    allocator_type& __a = __base::__alloc();
-    if (__back_spare() == 0)
-        __add_back_capacity();
-    // __back_spare() >= 1
-    __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()),
-                              _VSTD::forward<_Args>(__args)...);
-    ++__base::size();
-#if _LIBCPP_STD_VER > 14
-    return *--__base::end();
-#endif
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::push_front(value_type&& __v)
-{
-    allocator_type& __a = __base::__alloc();
-    if (__front_spare() == 0)
-        __add_front_capacity();
-    // __front_spare() >= 1
-    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::move(__v));
-    --__base::__start_;
-    ++__base::size();
-}
-
-
-template <class _Tp, class _Allocator>
-template <class... _Args>
-#if _LIBCPP_STD_VER > 14
-typename deque<_Tp, _Allocator>::reference
-#else
-void
-#endif
-deque<_Tp, _Allocator>::emplace_front(_Args&&... __args)
-{
-    allocator_type& __a = __base::__alloc();
-    if (__front_spare() == 0)
-        __add_front_capacity();
-    // __front_spare() >= 1
-    __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::forward<_Args>(__args)...);
-    --__base::__start_;
-    ++__base::size();
-#if _LIBCPP_STD_VER > 14
-    return *__base::begin();
-#endif
-}
-
-template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::insert(const_iterator __p, value_type&& __v)
-{
-    size_type __pos = __p - __base::begin();
-    size_type __to_end = __base::size() - __pos;
-    allocator_type& __a = __base::__alloc();
-    if (__pos < __to_end)
-    {   // insert by shifting things backward
-        if (__front_spare() == 0)
-            __add_front_capacity();
-        // __front_spare() >= 1
-        if (__pos == 0)
-        {
-            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::move(__v));
-            --__base::__start_;
-            ++__base::size();
-        }
-        else
-        {
-            iterator __b = __base::begin();
-            iterator __bm1 = _VSTD::prev(__b);
-            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
-            --__base::__start_;
-            ++__base::size();
-            if (__pos > 1)
-                __b = _VSTD::move(_VSTD::next(__b), __b + __pos, __b);
-            *__b = _VSTD::move(__v);
-        }
-    }
-    else
-    {   // insert by shifting things forward
-        if (__back_spare() == 0)
-            __add_back_capacity();
-        // __back_capacity >= 1
-        size_type __de = __base::size() - __pos;
-        if (__de == 0)
-        {
-            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::move(__v));
-            ++__base::size();
-        }
-        else
-        {
-            iterator __e = __base::end();
-            iterator __em1 = _VSTD::prev(__e);
-            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
-            ++__base::size();
-            if (__de > 1)
-                __e = _VSTD::move_backward(__e - __de, __em1, __e);
-            *--__e = _VSTD::move(__v);
-        }
-    }
-    return __base::begin() + __pos;
-}
-
-template <class _Tp, class _Allocator>
-template <class... _Args>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::emplace(const_iterator __p, _Args&&... __args)
-{
-    size_type __pos = __p - __base::begin();
-    size_type __to_end = __base::size() - __pos;
-    allocator_type& __a = __base::__alloc();
-    if (__pos < __to_end)
-    {   // insert by shifting things backward
-        if (__front_spare() == 0)
-            __add_front_capacity();
-        // __front_spare() >= 1
-        if (__pos == 0)
-        {
-            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), _VSTD::forward<_Args>(__args)...);
-            --__base::__start_;
-            ++__base::size();
-        }
-        else
-        {
-            __temp_value<value_type, _Allocator> __tmp(this->__alloc(), _VSTD::forward<_Args>(__args)...);
-            iterator __b = __base::begin();
-            iterator __bm1 = _VSTD::prev(__b);
-            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
-            --__base::__start_;
-            ++__base::size();
-            if (__pos > 1)
-                __b = _VSTD::move(_VSTD::next(__b), __b + __pos, __b);
-            *__b = _VSTD::move(__tmp.get());
-        }
-    }
-    else
-    {   // insert by shifting things forward
-        if (__back_spare() == 0)
-            __add_back_capacity();
-        // __back_capacity >= 1
-        size_type __de = __base::size() - __pos;
-        if (__de == 0)
-        {
-            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), _VSTD::forward<_Args>(__args)...);
-            ++__base::size();
-        }
-        else
-        {
-            __temp_value<value_type, _Allocator> __tmp(this->__alloc(), _VSTD::forward<_Args>(__args)...);
-            iterator __e = __base::end();
-            iterator __em1 = _VSTD::prev(__e);
-            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
-            ++__base::size();
-            if (__de > 1)
-                __e = _VSTD::move_backward(__e - __de, __em1, __e);
-            *--__e = _VSTD::move(__tmp.get());
-        }
-    }
-    return __base::begin() + __pos;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-
-template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::insert(const_iterator __p, const value_type& __v)
-{
-    size_type __pos = __p - __base::begin();
-    size_type __to_end = __base::size() - __pos;
-    allocator_type& __a = __base::__alloc();
-    if (__pos < __to_end)
-    {   // insert by shifting things backward
-        if (__front_spare() == 0)
-            __add_front_capacity();
-        // __front_spare() >= 1
-        if (__pos == 0)
-        {
-            __alloc_traits::construct(__a, _VSTD::addressof(*--__base::begin()), __v);
-            --__base::__start_;
-            ++__base::size();
-        }
-        else
-        {
-            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
-            iterator __b = __base::begin();
-            iterator __bm1 = _VSTD::prev(__b);
-            if (__vt == pointer_traits<const_pointer>::pointer_to(*__b))
-                __vt = pointer_traits<const_pointer>::pointer_to(*__bm1);
-            __alloc_traits::construct(__a, _VSTD::addressof(*__bm1), _VSTD::move(*__b));
-            --__base::__start_;
-            ++__base::size();
-            if (__pos > 1)
-                __b = __move_and_check(_VSTD::next(__b), __b + __pos, __b, __vt);
-            *__b = *__vt;
-        }
-    }
-    else
-    {   // insert by shifting things forward
-        if (__back_spare() == 0)
-            __add_back_capacity();
-        // __back_capacity >= 1
-        size_type __de = __base::size() - __pos;
-        if (__de == 0)
-        {
-            __alloc_traits::construct(__a, _VSTD::addressof(*__base::end()), __v);
-            ++__base::size();
-        }
-        else
-        {
-            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
-            iterator __e = __base::end();
-            iterator __em1 = _VSTD::prev(__e);
-            if (__vt == pointer_traits<const_pointer>::pointer_to(*__em1))
-                __vt = pointer_traits<const_pointer>::pointer_to(*__e);
-            __alloc_traits::construct(__a, _VSTD::addressof(*__e), _VSTD::move(*__em1));
-            ++__base::size();
-            if (__de > 1)
-                __e = __move_backward_and_check(__e - __de, __em1, __e, __vt);
-            *--__e = *__vt;
-        }
-    }
-    return __base::begin() + __pos;
-}
-
-template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::insert(const_iterator __p, size_type __n, const value_type& __v)
-{
-    size_type __pos = __p - __base::begin();
-    size_type __to_end = __base::size() - __pos;
-    allocator_type& __a = __base::__alloc();
-    if (__pos < __to_end)
-    {   // insert by shifting things backward
-        if (__n > __front_spare())
-            __add_front_capacity(__n - __front_spare());
-        // __n <= __front_spare()
-        iterator __old_begin = __base::begin();
-        iterator __i = __old_begin;
-        if (__n > __pos)
-        {
-            for (size_type __m = __n - __pos; __m; --__m, --__base::__start_, ++__base::size())
-                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), __v);
-            __n = __pos;
-        }
-        if (__n > 0)
-        {
-            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
-            iterator __obn = __old_begin + __n;
-            __move_construct_backward_and_check(__old_begin, __obn, __i, __vt);
-            if (__n < __pos)
-                __old_begin = __move_and_check(__obn, __old_begin + __pos, __old_begin, __vt);
-            _VSTD::fill_n(__old_begin, __n, *__vt);
-        }
-    }
-    else
-    {   // insert by shifting things forward
-        size_type __back_capacity = __back_spare();
-        if (__n > __back_capacity)
-            __add_back_capacity(__n - __back_capacity);
-        // __n <= __back_capacity
-        iterator __old_end = __base::end();
-        iterator __i = __old_end;
-        size_type __de = __base::size() - __pos;
-        if (__n > __de)
-        {
-            for (size_type __m = __n - __de; __m; --__m, ++__i, ++__base::size())
-                __alloc_traits::construct(__a, _VSTD::addressof(*__i), __v);
-            __n = __de;
-        }
-        if (__n > 0)
-        {
-            const_pointer __vt = pointer_traits<const_pointer>::pointer_to(__v);
-            iterator __oen = __old_end - __n;
-            __move_construct_and_check(__oen, __old_end, __i, __vt);
-            if (__n < __de)
-                __old_end = __move_backward_and_check(__old_end - __de, __oen, __old_end, __vt);
-            _VSTD::fill_n(__old_end - __n, __n, *__vt);
-        }
-    }
-    return __base::begin() + __pos;
-}
-
-template <class _Tp, class _Allocator>
-template <class _InputIter>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::insert(const_iterator __p, _InputIter __f, _InputIter __l,
-                               typename enable_if<__is_input_iterator<_InputIter>::value
-                                               &&!__is_forward_iterator<_InputIter>::value>::type*)
-{
-    __split_buffer<value_type, allocator_type&> __buf(__base::__alloc());
-    __buf.__construct_at_end(__f, __l);
-    typedef typename __split_buffer<value_type, allocator_type&>::iterator __bi;
-    return insert(__p, move_iterator<__bi>(__buf.begin()), move_iterator<__bi>(__buf.end()));
-}
-
-template <class _Tp, class _Allocator>
-template <class _ForwardIterator>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::insert(const_iterator __p, _ForwardIterator __f, _ForwardIterator __l,
-                               typename enable_if<__is_forward_iterator<_ForwardIterator>::value
-                                               &&!__is_bidirectional_iterator<_ForwardIterator>::value>::type*)
-{
-    size_type __n = _VSTD::distance(__f, __l);
-    __split_buffer<value_type, allocator_type&> __buf(__n, 0, __base::__alloc());
-    __buf.__construct_at_end(__f, __l);
-    typedef typename __split_buffer<value_type, allocator_type&>::iterator __fwd;
-    return insert(__p, move_iterator<__fwd>(__buf.begin()), move_iterator<__fwd>(__buf.end()));
-}
-
-template <class _Tp, class _Allocator>
-template <class _BiIter>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::insert(const_iterator __p, _BiIter __f, _BiIter __l,
-                               typename enable_if<__is_bidirectional_iterator<_BiIter>::value>::type*)
-{
-    size_type __n = _VSTD::distance(__f, __l);
-    size_type __pos = __p - __base::begin();
-    size_type __to_end = __base::size() - __pos;
-    allocator_type& __a = __base::__alloc();
-    if (__pos < __to_end)
-    {   // insert by shifting things backward
-        if (__n > __front_spare())
-            __add_front_capacity(__n - __front_spare());
-        // __n <= __front_spare()
-        iterator __old_begin = __base::begin();
-        iterator __i = __old_begin;
-        _BiIter __m = __f;
-        if (__n > __pos)
-        {
-            __m = __pos < __n / 2 ? _VSTD::prev(__l, __pos) : _VSTD::next(__f, __n - __pos);
-            for (_BiIter __j = __m; __j != __f; --__base::__start_, ++__base::size())
-                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), *--__j);
-            __n = __pos;
-        }
-        if (__n > 0)
-        {
-            iterator __obn = __old_begin + __n;
-            for (iterator __j = __obn; __j != __old_begin;)
-            {
-                __alloc_traits::construct(__a, _VSTD::addressof(*--__i), _VSTD::move(*--__j));
-                --__base::__start_;
-                ++__base::size();
-            }
-            if (__n < __pos)
-                __old_begin = _VSTD::move(__obn, __old_begin + __pos, __old_begin);
-            _VSTD::copy(__m, __l, __old_begin);
-        }
-    }
-    else
-    {   // insert by shifting things forward
-        size_type __back_capacity = __back_spare();
-        if (__n > __back_capacity)
-            __add_back_capacity(__n - __back_capacity);
-        // __n <= __back_capacity
-        iterator __old_end = __base::end();
-        iterator __i = __old_end;
-        _BiIter __m = __l;
-        size_type __de = __base::size() - __pos;
-        if (__n > __de)
-        {
-            __m = __de < __n / 2 ? _VSTD::next(__f, __de) : _VSTD::prev(__l, __n - __de);
-            for (_BiIter __j = __m; __j != __l; ++__i, (void) ++__j, ++__base::size())
-                __alloc_traits::construct(__a, _VSTD::addressof(*__i), *__j);
-            __n = __de;
-        }
-        if (__n > 0)
-        {
-            iterator __oen = __old_end - __n;
-            for (iterator __j = __oen; __j != __old_end; ++__i, ++__j, ++__base::size())
-                __alloc_traits::construct(__a, _VSTD::addressof(*__i), _VSTD::move(*__j));
-            if (__n < __de)
-                __old_end = _VSTD::move_backward(__old_end - __de, __oen, __old_end);
-            _VSTD::copy_backward(__f, __m, __old_end);
-        }
-    }
-    return __base::begin() + __pos;
-}
-
-template <class _Tp, class _Allocator>
-template <class _InpIter>
-void
-deque<_Tp, _Allocator>::__append(_InpIter __f, _InpIter __l,
-                                 typename enable_if<__is_input_iterator<_InpIter>::value &&
-                                                   !__is_forward_iterator<_InpIter>::value>::type*)
-{
-    for (; __f != __l; ++__f)
-#ifdef _LIBCPP_CXX03_LANG
-        push_back(*__f);
-#else
-        emplace_back(*__f);
-#endif
-}
-
-template <class _Tp, class _Allocator>
-template <class _ForIter>
-void
-deque<_Tp, _Allocator>::__append(_ForIter __f, _ForIter __l,
-                                 typename enable_if<__is_forward_iterator<_ForIter>::value>::type*)
-{
-    size_type __n = _VSTD::distance(__f, __l);
-    allocator_type& __a = __base::__alloc();
-    size_type __back_capacity = __back_spare();
-    if (__n > __back_capacity)
-        __add_back_capacity(__n - __back_capacity);
-    // __n <= __back_capacity
-    for (iterator __i = __base::end(); __f != __l; ++__i, (void) ++__f, ++__base::size())
-        __alloc_traits::construct(__a, _VSTD::addressof(*__i), *__f);
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__append(size_type __n)
-{
-    allocator_type& __a = __base::__alloc();
-    size_type __back_capacity = __back_spare();
-    if (__n > __back_capacity)
-        __add_back_capacity(__n - __back_capacity);
-    // __n <= __back_capacity
-    for (iterator __i = __base::end(); __n; --__n, ++__i, ++__base::size())
-        __alloc_traits::construct(__a, _VSTD::addressof(*__i));
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__append(size_type __n, const value_type& __v)
-{
-    allocator_type& __a = __base::__alloc();
-    size_type __back_capacity = __back_spare();
-    if (__n > __back_capacity)
-        __add_back_capacity(__n - __back_capacity);
-    // __n <= __back_capacity
-    for (iterator __i = __base::end(); __n; --__n, ++__i, ++__base::size())
-        __alloc_traits::construct(__a, _VSTD::addressof(*__i), __v);
-}
-
-// Create front capacity for one block of elements.
-// Strong guarantee.  Either do it or don't touch anything.
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__add_front_capacity()
-{
-    allocator_type& __a = __base::__alloc();
-    if (__back_spare() >= __base::__block_size)
-    {
-        __base::__start_ += __base::__block_size;
-        pointer __pt = __base::__map_.back();
-        __base::__map_.pop_back();
-        __base::__map_.push_front(__pt);
-    }
-    // Else if __base::__map_.size() < __base::__map_.capacity() then we need to allocate 1 buffer
-    else if (__base::__map_.size() < __base::__map_.capacity())
-    {   // we can put the new buffer into the map, but don't shift things around
-        // until all buffers are allocated.  If we throw, we don't need to fix
-        // anything up (any added buffers are undetectible)
-        if (__base::__map_.__front_spare() > 0)
-            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
-        else
-        {
-            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
-            // Done allocating, reorder capacity
-            pointer __pt = __base::__map_.back();
-            __base::__map_.pop_back();
-            __base::__map_.push_front(__pt);
-        }
-        __base::__start_ = __base::__map_.size() == 1 ?
-                               __base::__block_size / 2 :
-                               __base::__start_ + __base::__block_size;
-    }
-    // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
-    else
-    {
-        __split_buffer<pointer, typename __base::__pointer_allocator&>
-            __buf(max<size_type>(2 * __base::__map_.capacity(), 1),
-                  0, __base::__map_.__alloc());
-
-        typedef __allocator_destructor<_Allocator> _Dp;
-        unique_ptr<pointer, _Dp> __hold(
-            __alloc_traits::allocate(__a, __base::__block_size),
-                _Dp(__a, __base::__block_size));
-        __buf.push_back(__hold.get());
-        __hold.release();
-
-        for (typename __base::__map_pointer __i = __base::__map_.begin();
-                __i != __base::__map_.end(); ++__i)
-            __buf.push_back(*__i);
-        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
-        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
-        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
-        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
-        __base::__start_ = __base::__map_.size() == 1 ?
-                               __base::__block_size / 2 :
-                               __base::__start_ + __base::__block_size;
-    }
-}
-
-// Create front capacity for __n elements.
-// Strong guarantee.  Either do it or don't touch anything.
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__add_front_capacity(size_type __n)
-{
-    allocator_type& __a = __base::__alloc();
-    size_type __nb = __recommend_blocks(__n + __base::__map_.empty());
-    // Number of unused blocks at back:
-    size_type __back_capacity = __back_spare() / __base::__block_size;
-    __back_capacity = _VSTD::min(__back_capacity, __nb);  // don't take more than you need
-    __nb -= __back_capacity;  // number of blocks need to allocate
-    // If __nb == 0, then we have sufficient capacity.
-    if (__nb == 0)
-    {
-        __base::__start_ += __base::__block_size * __back_capacity;
-        for (; __back_capacity > 0; --__back_capacity)
-        {
-            pointer __pt = __base::__map_.back();
-            __base::__map_.pop_back();
-            __base::__map_.push_front(__pt);
-        }
-    }
-    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
-    else if (__nb <= __base::__map_.capacity() - __base::__map_.size())
-    {   // we can put the new buffers into the map, but don't shift things around
-        // until all buffers are allocated.  If we throw, we don't need to fix
-        // anything up (any added buffers are undetectible)
-        for (; __nb > 0; --__nb, __base::__start_ += __base::__block_size - (__base::__map_.size() == 1))
-        {
-            if (__base::__map_.__front_spare() == 0)
-                break;
-            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
-        }
-        for (; __nb > 0; --__nb, ++__back_capacity)
-            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
-        // Done allocating, reorder capacity
-        __base::__start_ += __back_capacity * __base::__block_size;
-        for (; __back_capacity > 0; --__back_capacity)
-        {
-            pointer __pt = __base::__map_.back();
-            __base::__map_.pop_back();
-            __base::__map_.push_front(__pt);
-        }
-    }
-    // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
-    else
-    {
-        size_type __ds = (__nb + __back_capacity) * __base::__block_size - __base::__map_.empty();
-        __split_buffer<pointer, typename __base::__pointer_allocator&>
-            __buf(max<size_type>(2* __base::__map_.capacity(),
-                                 __nb + __base::__map_.size()),
-                  0, __base::__map_.__alloc());
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (; __nb > 0; --__nb)
-                __buf.push_back(__alloc_traits::allocate(__a, __base::__block_size));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            for (typename __base::__map_pointer __i = __buf.begin();
-                    __i != __buf.end(); ++__i)
-                __alloc_traits::deallocate(__a, *__i, __base::__block_size);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        for (; __back_capacity > 0; --__back_capacity)
-        {
-            __buf.push_back(__base::__map_.back());
-            __base::__map_.pop_back();
-        }
-        for (typename __base::__map_pointer __i = __base::__map_.begin();
-                __i != __base::__map_.end(); ++__i)
-            __buf.push_back(*__i);
-        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
-        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
-        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
-        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
-        __base::__start_ += __ds;
-    }
-}
-
-// Create back capacity for one block of elements.
-// Strong guarantee.  Either do it or don't touch anything.
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__add_back_capacity()
-{
-    allocator_type& __a = __base::__alloc();
-    if (__front_spare() >= __base::__block_size)
-    {
-        __base::__start_ -= __base::__block_size;
-        pointer __pt = __base::__map_.front();
-        __base::__map_.pop_front();
-        __base::__map_.push_back(__pt);
-    }
-    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
-    else if (__base::__map_.size() < __base::__map_.capacity())
-    {   // we can put the new buffer into the map, but don't shift things around
-        // until it is allocated.  If we throw, we don't need to fix
-        // anything up (any added buffers are undetectible)
-        if (__base::__map_.__back_spare() != 0)
-            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
-        else
-        {
-            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
-            // Done allocating, reorder capacity
-            pointer __pt = __base::__map_.front();
-            __base::__map_.pop_front();
-            __base::__map_.push_back(__pt);
-        }
-    }
-    // Else need to allocate 1 buffer, *and* we need to reallocate __map_.
-    else
-    {
-        __split_buffer<pointer, typename __base::__pointer_allocator&>
-            __buf(max<size_type>(2* __base::__map_.capacity(), 1),
-                  __base::__map_.size(),
-                  __base::__map_.__alloc());
-
-        typedef __allocator_destructor<_Allocator> _Dp;
-        unique_ptr<pointer, _Dp> __hold(
-            __alloc_traits::allocate(__a, __base::__block_size),
-                _Dp(__a, __base::__block_size));
-        __buf.push_back(__hold.get());
-        __hold.release();
-
-        for (typename __base::__map_pointer __i = __base::__map_.end();
-                __i != __base::__map_.begin();)
-            __buf.push_front(*--__i);
-        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
-        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
-        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
-        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
-    }
-}
-
-// Create back capacity for __n elements.
-// Strong guarantee.  Either do it or don't touch anything.
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__add_back_capacity(size_type __n)
-{
-    allocator_type& __a = __base::__alloc();
-    size_type __nb = __recommend_blocks(__n + __base::__map_.empty());
-    // Number of unused blocks at front:
-    size_type __front_capacity = __front_spare() / __base::__block_size;
-    __front_capacity = _VSTD::min(__front_capacity, __nb);  // don't take more than you need
-    __nb -= __front_capacity;  // number of blocks need to allocate
-    // If __nb == 0, then we have sufficient capacity.
-    if (__nb == 0)
-    {
-        __base::__start_ -= __base::__block_size * __front_capacity;
-        for (; __front_capacity > 0; --__front_capacity)
-        {
-            pointer __pt = __base::__map_.front();
-            __base::__map_.pop_front();
-            __base::__map_.push_back(__pt);
-        }
-    }
-    // Else if __nb <= __map_.capacity() - __map_.size() then we need to allocate __nb buffers
-    else if (__nb <= __base::__map_.capacity() - __base::__map_.size())
-    {   // we can put the new buffers into the map, but don't shift things around
-        // until all buffers are allocated.  If we throw, we don't need to fix
-        // anything up (any added buffers are undetectible)
-        for (; __nb > 0; --__nb)
-        {
-            if (__base::__map_.__back_spare() == 0)
-                break;
-            __base::__map_.push_back(__alloc_traits::allocate(__a, __base::__block_size));
-        }
-        for (; __nb > 0; --__nb, ++__front_capacity, __base::__start_ +=
-                                 __base::__block_size - (__base::__map_.size() == 1))
-            __base::__map_.push_front(__alloc_traits::allocate(__a, __base::__block_size));
-        // Done allocating, reorder capacity
-        __base::__start_ -= __base::__block_size * __front_capacity;
-        for (; __front_capacity > 0; --__front_capacity)
-        {
-            pointer __pt = __base::__map_.front();
-            __base::__map_.pop_front();
-            __base::__map_.push_back(__pt);
-        }
-    }
-    // Else need to allocate __nb buffers, *and* we need to reallocate __map_.
-    else
-    {
-        size_type __ds = __front_capacity * __base::__block_size;
-        __split_buffer<pointer, typename __base::__pointer_allocator&>
-            __buf(max<size_type>(2* __base::__map_.capacity(),
-                                 __nb + __base::__map_.size()),
-                  __base::__map_.size() - __front_capacity,
-                  __base::__map_.__alloc());
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (; __nb > 0; --__nb)
-                __buf.push_back(__alloc_traits::allocate(__a, __base::__block_size));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            for (typename __base::__map_pointer __i = __buf.begin();
-                    __i != __buf.end(); ++__i)
-                __alloc_traits::deallocate(__a, *__i, __base::__block_size);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        for (; __front_capacity > 0; --__front_capacity)
-        {
-            __buf.push_back(__base::__map_.front());
-            __base::__map_.pop_front();
-        }
-        for (typename __base::__map_pointer __i = __base::__map_.end();
-                __i != __base::__map_.begin();)
-            __buf.push_front(*--__i);
-        _VSTD::swap(__base::__map_.__first_, __buf.__first_);
-        _VSTD::swap(__base::__map_.__begin_, __buf.__begin_);
-        _VSTD::swap(__base::__map_.__end_, __buf.__end_);
-        _VSTD::swap(__base::__map_.__end_cap(), __buf.__end_cap());
-        __base::__start_ -= __ds;
-    }
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::pop_front()
-{
-    allocator_type& __a = __base::__alloc();
-    __alloc_traits::destroy(__a, __to_raw_pointer(*(__base::__map_.begin() +
-                                                    __base::__start_ / __base::__block_size) +
-                                                    __base::__start_ % __base::__block_size));
-    --__base::size();
-    if (++__base::__start_ >= 2 * __base::__block_size)
-    {
-        __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
-        __base::__map_.pop_front();
-        __base::__start_ -= __base::__block_size;
-    }
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::pop_back()
-{
-    _LIBCPP_ASSERT(!empty(), "deque::pop_back called for empty deque");
-    allocator_type& __a = __base::__alloc();
-    size_type __p = __base::size() + __base::__start_ - 1;
-    __alloc_traits::destroy(__a, __to_raw_pointer(*(__base::__map_.begin() +
-                                                    __p / __base::__block_size) +
-                                                    __p % __base::__block_size));
-    --__base::size();
-    if (__back_spare() >= 2 * __base::__block_size)
-    {
-        __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
-        __base::__map_.pop_back();
-    }
-}
-
-// move assign [__f, __l) to [__r, __r + (__l-__f)).
-// If __vt points into [__f, __l), then subtract (__f - __r) from __vt.
-template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::__move_and_check(iterator __f, iterator __l, iterator __r,
-                                         const_pointer& __vt)
-{
-    // as if
-    //   for (; __f != __l; ++__f, ++__r)
-    //       *__r = _VSTD::move(*__f);
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        pointer __fb = __f.__ptr_;
-        pointer __fe = *__f.__m_iter_ + __base::__block_size;
-        difference_type __bs = __fe - __fb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __fe = __fb + __bs;
-        }
-        if (__fb <= __vt && __vt < __fe)
-            __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) -= __f - __r).__ptr_;
-        __r = _VSTD::move(__fb, __fe, __r);
-        __n -= __bs;
-        __f += __bs;
-    }
-    return __r;
-}
-
-// move assign [__f, __l) to [__r - (__l-__f), __r) backwards.
-// If __vt points into [__f, __l), then add (__r - __l) to __vt.
-template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::__move_backward_and_check(iterator __f, iterator __l, iterator __r,
-                                                  const_pointer& __vt)
-{
-    // as if
-    //   while (__f != __l)
-    //       *--__r = _VSTD::move(*--__l);
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        --__l;
-        pointer __lb = *__l.__m_iter_;
-        pointer __le = __l.__ptr_ + 1;
-        difference_type __bs = __le - __lb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __lb = __le - __bs;
-        }
-        if (__lb <= __vt && __vt < __le)
-            __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) += __r - __l - 1).__ptr_;
-        __r = _VSTD::move_backward(__lb, __le, __r);
-        __n -= __bs;
-        __l -= __bs - 1;
-    }
-    return __r;
-}
-
-// move construct [__f, __l) to [__r, __r + (__l-__f)).
-// If __vt points into [__f, __l), then add (__r - __f) to __vt.
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__move_construct_and_check(iterator __f, iterator __l,
-                                                   iterator __r, const_pointer& __vt)
-{
-    allocator_type& __a = __base::__alloc();
-    // as if
-    //   for (; __f != __l; ++__r, ++__f, ++__base::size())
-    //       __alloc_traits::construct(__a, _VSTD::addressof(*__r), _VSTD::move(*__f));
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        pointer __fb = __f.__ptr_;
-        pointer __fe = *__f.__m_iter_ + __base::__block_size;
-        difference_type __bs = __fe - __fb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __fe = __fb + __bs;
-        }
-        if (__fb <= __vt && __vt < __fe)
-            __vt = (const_iterator(static_cast<__map_const_pointer>(__f.__m_iter_), __vt) += __r - __f).__ptr_;
-        for (; __fb != __fe; ++__fb, ++__r, ++__base::size())
-            __alloc_traits::construct(__a, _VSTD::addressof(*__r), _VSTD::move(*__fb));
-        __n -= __bs;
-        __f += __bs;
-    }
-}
-
-// move construct [__f, __l) to [__r - (__l-__f), __r) backwards.
-// If __vt points into [__f, __l), then subtract (__l - __r) from __vt.
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__move_construct_backward_and_check(iterator __f, iterator __l,
-                                                            iterator __r, const_pointer& __vt)
-{
-    allocator_type& __a = __base::__alloc();
-    // as if
-    //   for (iterator __j = __l; __j != __f;)
-    //   {
-    //       __alloc_traitsconstruct(__a, _VSTD::addressof(*--__r), _VSTD::move(*--__j));
-    //       --__base::__start_;
-    //       ++__base::size();
-    //   }
-    difference_type __n = __l - __f;
-    while (__n > 0)
-    {
-        --__l;
-        pointer __lb = *__l.__m_iter_;
-        pointer __le = __l.__ptr_ + 1;
-        difference_type __bs = __le - __lb;
-        if (__bs > __n)
-        {
-            __bs = __n;
-            __lb = __le - __bs;
-        }
-        if (__lb <= __vt && __vt < __le)
-            __vt = (const_iterator(static_cast<__map_const_pointer>(__l.__m_iter_), __vt) -= __l - __r + 1).__ptr_;
-        while (__le != __lb)
-        {
-            __alloc_traits::construct(__a, _VSTD::addressof(*--__r), _VSTD::move(*--__le));
-            --__base::__start_;
-            ++__base::size();
-        }
-        __n -= __bs;
-        __l -= __bs - 1;
-    }
-}
-
-template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::erase(const_iterator __f)
-{
-    iterator __b = __base::begin();
-    difference_type __pos = __f - __b;
-    iterator __p = __b + __pos;
-    allocator_type& __a = __base::__alloc();
-    if (static_cast<size_t>(__pos) <= (__base::size() - 1) / 2)
-    {   // erase from front
-        _VSTD::move_backward(__b, __p, _VSTD::next(__p));
-        __alloc_traits::destroy(__a, _VSTD::addressof(*__b));
-        --__base::size();
-        ++__base::__start_;
-        if (__front_spare() >= 2 * __base::__block_size)
-        {
-            __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
-            __base::__map_.pop_front();
-            __base::__start_ -= __base::__block_size;
-        }
-    }
-    else
-    {   // erase from back
-        iterator __i = _VSTD::move(_VSTD::next(__p), __base::end(), __p);
-        __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
-        --__base::size();
-        if (__back_spare() >= 2 * __base::__block_size)
-        {
-            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
-            __base::__map_.pop_back();
-        }
-    }
-    return __base::begin() + __pos;
-}
-
-template <class _Tp, class _Allocator>
-typename deque<_Tp, _Allocator>::iterator
-deque<_Tp, _Allocator>::erase(const_iterator __f, const_iterator __l)
-{
-    difference_type __n = __l - __f;
-    iterator __b = __base::begin();
-    difference_type __pos = __f - __b;
-    iterator __p = __b + __pos;
-    if (__n > 0)
-    {
-        allocator_type& __a = __base::__alloc();
-        if (static_cast<size_t>(__pos) <= (__base::size() - __n) / 2)
-        {   // erase from front
-            iterator __i = _VSTD::move_backward(__b, __p, __p + __n);
-            for (; __b != __i; ++__b)
-                __alloc_traits::destroy(__a, _VSTD::addressof(*__b));
-            __base::size() -= __n;
-            __base::__start_ += __n;
-            while (__front_spare() >= 2 * __base::__block_size)
-            {
-                __alloc_traits::deallocate(__a, __base::__map_.front(), __base::__block_size);
-                __base::__map_.pop_front();
-                __base::__start_ -= __base::__block_size;
-            }
-        }
-        else
-        {   // erase from back
-            iterator __i = _VSTD::move(__p + __n, __base::end(), __p);
-            for (iterator __e = __base::end(); __i != __e; ++__i)
-                __alloc_traits::destroy(__a, _VSTD::addressof(*__i));
-            __base::size() -= __n;
-            while (__back_spare() >= 2 * __base::__block_size)
-            {
-                __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
-                __base::__map_.pop_back();
-            }
-        }
-    }
-    return __base::begin() + __pos;
-}
-
-template <class _Tp, class _Allocator>
-void
-deque<_Tp, _Allocator>::__erase_to_end(const_iterator __f)
-{
-    iterator __e = __base::end();
-    difference_type __n = __e - __f;
-    if (__n > 0)
-    {
-        allocator_type& __a = __base::__alloc();
-        iterator __b = __base::begin();
-        difference_type __pos = __f - __b;
-        for (iterator __p = __b + __pos; __p != __e; ++__p)
-            __alloc_traits::destroy(__a, _VSTD::addressof(*__p));
-        __base::size() -= __n;
-        while (__back_spare() >= 2 * __base::__block_size)
-        {
-            __alloc_traits::deallocate(__a, __base::__map_.back(), __base::__block_size);
-            __base::__map_.pop_back();
-        }
-    }
-}
-
-template <class _Tp, class _Allocator>
-inline
-void
-deque<_Tp, _Allocator>::swap(deque& __c)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT
-#else
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
-                    __is_nothrow_swappable<allocator_type>::value)
-#endif
-{
-    __base::swap(__c);
-}
-
-template <class _Tp, class _Allocator>
-inline
-void
-deque<_Tp, _Allocator>::clear() _NOEXCEPT
-{
-    __base::clear();
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
-{
-    const typename deque<_Tp, _Allocator>::size_type __sz = __x.size();
-    return __sz == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
-{
-    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const deque<_Tp, _Allocator>& __x, const deque<_Tp, _Allocator>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(deque<_Tp, _Allocator>& __x, deque<_Tp, _Allocator>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Tp, class _Allocator, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase(deque<_Tp, _Allocator>& __c, const _Up& __v)
-{ __c.erase(_VSTD::remove(__c.begin(), __c.end(), __v), __c.end()); }
-
-template <class _Tp, class _Allocator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(deque<_Tp, _Allocator>& __c, _Predicate __pred)
-{ __c.erase(_VSTD::remove_if(__c.begin(), __c.end(), __pred), __c.end()); }
-#endif
-
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_DEQUE
diff --git a/lib/libcxx/include/errno.h b/lib/libcxx/include/errno.h
deleted file mode 100644
index ee6429110cc..00000000000
--- a/lib/libcxx/include/errno.h
+++ /dev/null
@@ -1,398 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- errno.h -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_ERRNO_H
-#define _LIBCPP_ERRNO_H
-
-/*
-    errno.h synopsis
-
-Macros:
-
-    EDOM
-    EILSEQ  // C99
-    ERANGE
-    errno
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <errno.h>
-
-#ifdef __cplusplus
-
-#if !defined(EOWNERDEAD) || !defined(ENOTRECOVERABLE)
-
-#ifdef ELAST
-
-static const int __elast1 = ELAST+1;
-static const int __elast2 = ELAST+2;
-
-#else
-
-static const int __elast1 = 104;
-static const int __elast2 = 105;
-
-#endif
-
-#ifdef ENOTRECOVERABLE
-
-#define EOWNERDEAD __elast1
-
-#ifdef ELAST
-#undef ELAST
-#define ELAST EOWNERDEAD
-#endif
-
-#elif defined(EOWNERDEAD)
-
-#define ENOTRECOVERABLE __elast1
-#ifdef ELAST
-#undef ELAST
-#define ELAST ENOTRECOVERABLE
-#endif
-
-#else  // defined(EOWNERDEAD)
-
-#define EOWNERDEAD __elast1
-#define ENOTRECOVERABLE __elast2
-#ifdef ELAST
-#undef ELAST
-#define ELAST ENOTRECOVERABLE
-#endif
-
-#endif  // defined(EOWNERDEAD)
-
-#endif  // !defined(EOWNERDEAD) || !defined(ENOTRECOVERABLE)
-
-//  supply errno values likely to be missing, particularly on Windows
-
-#ifndef EAFNOSUPPORT
-#define EAFNOSUPPORT 9901
-#endif
-
-#ifndef EADDRINUSE
-#define EADDRINUSE 9902
-#endif
-
-#ifndef EADDRNOTAVAIL
-#define EADDRNOTAVAIL 9903
-#endif
-
-#ifndef EISCONN
-#define EISCONN 9904
-#endif
-
-#ifndef EBADMSG
-#define EBADMSG 9905
-#endif
-
-#ifndef ECONNABORTED
-#define ECONNABORTED 9906
-#endif
-
-#ifndef EALREADY
-#define EALREADY 9907
-#endif
-
-#ifndef ECONNREFUSED
-#define ECONNREFUSED 9908
-#endif
-
-#ifndef ECONNRESET
-#define ECONNRESET 9909
-#endif
-
-#ifndef EDESTADDRREQ
-#define EDESTADDRREQ 9910
-#endif
-
-#ifndef EHOSTUNREACH
-#define EHOSTUNREACH 9911
-#endif
-
-#ifndef EIDRM
-#define EIDRM 9912
-#endif
-
-#ifndef EMSGSIZE
-#define EMSGSIZE 9913
-#endif
-
-#ifndef ENETDOWN
-#define ENETDOWN 9914
-#endif
-
-#ifndef ENETRESET
-#define ENETRESET 9915
-#endif
-
-#ifndef ENETUNREACH
-#define ENETUNREACH 9916
-#endif
-
-#ifndef ENOBUFS
-#define ENOBUFS 9917
-#endif
-
-#ifndef ENOLINK
-#define ENOLINK 9918
-#endif
-
-#ifndef ENODATA
-#define ENODATA 9919
-#endif
-
-#ifndef ENOMSG
-#define ENOMSG 9920
-#endif
-
-#ifndef ENOPROTOOPT
-#define ENOPROTOOPT 9921
-#endif
-
-#ifndef ENOSR
-#define ENOSR 9922
-#endif
-
-#ifndef ENOTSOCK
-#define ENOTSOCK 9923
-#endif
-
-#ifndef ENOSTR
-#define ENOSTR 9924
-#endif
-
-#ifndef ENOTCONN
-#define ENOTCONN 9925
-#endif
-
-#ifndef ENOTSUP
-#define ENOTSUP 9926
-#endif
-
-#ifndef ECANCELED
-#define ECANCELED 9927
-#endif
-
-#ifndef EINPROGRESS
-#define EINPROGRESS 9928
-#endif
-
-#ifndef EOPNOTSUPP
-#define EOPNOTSUPP 9929
-#endif
-
-#ifndef EWOULDBLOCK
-#define EWOULDBLOCK 9930
-#endif
-
-#ifndef EOWNERDEAD
-#define EOWNERDEAD  9931
-#endif
-
-#ifndef EPROTO
-#define EPROTO 9932
-#endif
-
-#ifndef EPROTONOSUPPORT
-#define EPROTONOSUPPORT 9933
-#endif
-
-#ifndef ENOTRECOVERABLE
-#define ENOTRECOVERABLE 9934
-#endif
-
-#ifndef ETIME
-#define ETIME 9935
-#endif
-
-#ifndef ETXTBSY
-#define ETXTBSY 9936
-#endif
-
-#ifndef ETIMEDOUT
-#define ETIMEDOUT 9938
-#endif
-
-#ifndef ELOOP
-#define ELOOP 9939
-#endif
-
-#ifndef EOVERFLOW
-#define EOVERFLOW 9940
-#endif
-
-#ifndef EPROTOTYPE
-#define EPROTOTYPE 9941
-#endif
-
-#ifndef ENOSYS
-#define ENOSYS 9942
-#endif
-
-#ifndef EINVAL
-#define EINVAL 9943
-#endif
-
-#ifndef ERANGE
-#define ERANGE 9944
-#endif
-
-#ifndef EILSEQ
-#define EILSEQ 9945
-#endif
-
-//  Windows Mobile doesn't appear to define these:
-
-#ifndef E2BIG
-#define E2BIG 9946
-#endif
-
-#ifndef EDOM
-#define EDOM 9947
-#endif
-
-#ifndef EFAULT
-#define EFAULT 9948
-#endif
-
-#ifndef EBADF
-#define EBADF 9949
-#endif
-
-#ifndef EPIPE
-#define EPIPE 9950
-#endif
-
-#ifndef EXDEV
-#define EXDEV 9951
-#endif
-
-#ifndef EBUSY
-#define EBUSY 9952
-#endif
-
-#ifndef ENOTEMPTY
-#define ENOTEMPTY 9953
-#endif
-
-#ifndef ENOEXEC
-#define ENOEXEC 9954
-#endif
-
-#ifndef EEXIST
-#define EEXIST 9955
-#endif
-
-#ifndef EFBIG
-#define EFBIG 9956
-#endif
-
-#ifndef ENAMETOOLONG
-#define ENAMETOOLONG 9957
-#endif
-
-#ifndef ENOTTY
-#define ENOTTY 9958
-#endif
-
-#ifndef EINTR
-#define EINTR 9959
-#endif
-
-#ifndef ESPIPE
-#define ESPIPE 9960
-#endif
-
-#ifndef EIO
-#define EIO 9961
-#endif
-
-#ifndef EISDIR
-#define EISDIR 9962
-#endif
-
-#ifndef ECHILD
-#define ECHILD 9963
-#endif
-
-#ifndef ENOLCK
-#define ENOLCK 9964
-#endif
-
-#ifndef ENOSPC
-#define ENOSPC 9965
-#endif
-
-#ifndef ENXIO
-#define ENXIO 9966
-#endif
-
-#ifndef ENODEV
-#define ENODEV 9967
-#endif
-
-#ifndef ENOENT
-#define ENOENT 9968
-#endif
-
-#ifndef ESRCH
-#define ESRCH 9969
-#endif
-
-#ifndef ENOTDIR
-#define ENOTDIR 9970
-#endif
-
-#ifndef ENOMEM
-#define ENOMEM 9971
-#endif
-
-#ifndef EPERM
-#define EPERM 9972
-#endif
-
-#ifndef EACCES
-#define EACCES 9973
-#endif
-
-#ifndef EROFS
-#define EROFS 9974
-#endif
-
-#ifndef EDEADLK
-#define EDEADLK 9975
-#endif
-
-#ifndef EAGAIN
-#define EAGAIN 9976
-#endif
-
-#ifndef ENFILE
-#define ENFILE 9977
-#endif
-
-#ifndef EMFILE
-#define EMFILE 9978
-#endif
-
-#ifndef EMLINK
-#define EMLINK 9979
-#endif
-
-#endif // __cplusplus
-
-#endif  // _LIBCPP_ERRNO_H
diff --git a/lib/libcxx/include/exception b/lib/libcxx/include/exception
deleted file mode 100644
index fdd83d10c3d..00000000000
--- a/lib/libcxx/include/exception
+++ /dev/null
@@ -1,338 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- exception ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXCEPTION
-#define _LIBCPP_EXCEPTION
-
-/*
-    exception synopsis
-
-namespace std
-{
-
-class exception
-{
-public:
-    exception() noexcept;
-    exception(const exception&) noexcept;
-    exception& operator=(const exception&) noexcept;
-    virtual ~exception() noexcept;
-    virtual const char* what() const noexcept;
-};
-
-class bad_exception
-    : public exception
-{
-public:
-    bad_exception() noexcept;
-    bad_exception(const bad_exception&) noexcept;
-    bad_exception& operator=(const bad_exception&) noexcept;
-    virtual ~bad_exception() noexcept;
-    virtual const char* what() const noexcept;
-};
-
-typedef void (*unexpected_handler)();
-unexpected_handler set_unexpected(unexpected_handler  f ) noexcept;
-unexpected_handler get_unexpected() noexcept;
-[[noreturn]] void unexpected();
-
-typedef void (*terminate_handler)();
-terminate_handler set_terminate(terminate_handler  f ) noexcept;
-terminate_handler get_terminate() noexcept;
-[[noreturn]] void terminate() noexcept;
-
-bool uncaught_exception()  noexcept;
-int  uncaught_exceptions() noexcept;  // C++17
-
-typedef unspecified exception_ptr;
-
-exception_ptr current_exception() noexcept;
-void rethrow_exception [[noreturn]] (exception_ptr p);
-template<class E> exception_ptr make_exception_ptr(E e) noexcept;
-
-class nested_exception
-{
-public:
-    nested_exception() noexcept;
-    nested_exception(const nested_exception&) noexcept = default;
-    nested_exception& operator=(const nested_exception&) noexcept = default;
-    virtual ~nested_exception() = default;
-
-    // access functions
-    [[noreturn]] void rethrow_nested() const;
-    exception_ptr nested_ptr() const noexcept;
-};
-
-template <class T> [[noreturn]] void throw_with_nested(T&& t);
-template <class E> void rethrow_if_nested(const E& e);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <cstddef>
-#include <cstdlib>
-#include <type_traits>
-#include <version>
-
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
-#include <vcruntime_exception.h>
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-namespace std  // purposefully not using versioning namespace
-{
-
-#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
-class _LIBCPP_EXCEPTION_ABI exception
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY exception() _NOEXCEPT {}
-    virtual ~exception() _NOEXCEPT;
-    virtual const char* what() const _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI bad_exception
-    : public exception
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY bad_exception() _NOEXCEPT {}
-    virtual ~bad_exception() _NOEXCEPT;
-    virtual const char* what() const _NOEXCEPT;
-};
-#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
-
-#if _LIBCPP_STD_VER <= 14 \
-    || defined(_LIBCPP_ENABLE_CXX17_REMOVED_UNEXPECTED_FUNCTIONS) \
-    || defined(_LIBCPP_BUILDING_LIBRARY)
-typedef void (*unexpected_handler)();
-_LIBCPP_FUNC_VIS unexpected_handler set_unexpected(unexpected_handler) _NOEXCEPT;
-_LIBCPP_FUNC_VIS unexpected_handler get_unexpected() _NOEXCEPT;
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void unexpected();
-#endif
-
-typedef void (*terminate_handler)();
-_LIBCPP_FUNC_VIS terminate_handler set_terminate(terminate_handler) _NOEXCEPT;
-_LIBCPP_FUNC_VIS terminate_handler get_terminate() _NOEXCEPT;
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void terminate() _NOEXCEPT;
-
-_LIBCPP_FUNC_VIS bool uncaught_exception() _NOEXCEPT;
-_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_UNCAUGHT_EXCEPTIONS int uncaught_exceptions() _NOEXCEPT;
-
-class _LIBCPP_TYPE_VIS exception_ptr;
-
-_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
-
-#ifndef _LIBCPP_ABI_MICROSOFT
-
-class _LIBCPP_TYPE_VIS exception_ptr
-{
-    void* __ptr_;
-public:
-    _LIBCPP_INLINE_VISIBILITY exception_ptr() _NOEXCEPT : __ptr_() {}
-    _LIBCPP_INLINE_VISIBILITY exception_ptr(nullptr_t) _NOEXCEPT : __ptr_() {}
-
-    exception_ptr(const exception_ptr&) _NOEXCEPT;
-    exception_ptr& operator=(const exception_ptr&) _NOEXCEPT;
-    ~exception_ptr() _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT
-    {return __ptr_ != nullptr;}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
-        {return __x.__ptr_ == __y.__ptr_;}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
-        {return !(__x == __y);}
-
-    friend _LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
-    friend _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr);
-};
-
-template<class _Ep>
-_LIBCPP_INLINE_VISIBILITY exception_ptr
-make_exception_ptr(_Ep __e) _NOEXCEPT
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-        throw __e;
-    }
-    catch (...)
-    {
-        return current_exception();
-    }
-#else
-    ((void)__e);
-    _VSTD::abort();
-#endif
-}
-
-#else // _LIBCPP_ABI_MICROSOFT
-
-class _LIBCPP_TYPE_VIS exception_ptr
-{
-#if defined(__clang__)
-#pragma clang diagnostic push
-#pragma clang diagnostic ignored "-Wunused-private-field"
-#endif
-    void* __ptr1_;
-    void* __ptr2_;
-#if defined(__clang__)
-#pragma clang diagnostic pop
-#endif
-public:
-    exception_ptr() _NOEXCEPT;
-    exception_ptr(nullptr_t) _NOEXCEPT;
-    exception_ptr(const exception_ptr& __other) _NOEXCEPT;
-    exception_ptr& operator=(const exception_ptr& __other) _NOEXCEPT;
-    exception_ptr& operator=(nullptr_t) _NOEXCEPT;
-    ~exception_ptr() _NOEXCEPT;
-    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT;
-};
-
-_LIBCPP_FUNC_VIS
-bool operator==(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT;
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(const exception_ptr& __x, const exception_ptr& __y) _NOEXCEPT
-    {return !(__x == __y);}
-
-_LIBCPP_FUNC_VIS void swap(exception_ptr&, exception_ptr&) _NOEXCEPT;
-
-_LIBCPP_FUNC_VIS exception_ptr __copy_exception_ptr(void *__except, const void* __ptr);
-_LIBCPP_FUNC_VIS exception_ptr current_exception() _NOEXCEPT;
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void rethrow_exception(exception_ptr p);
-
-// This is a built-in template function which automagically extracts the required
-// information.
-template <class _E> void *__GetExceptionInfo(_E);
-
-template<class _Ep>
-_LIBCPP_INLINE_VISIBILITY exception_ptr
-make_exception_ptr(_Ep __e) _NOEXCEPT
-{
-  return __copy_exception_ptr(_VSTD::addressof(__e), __GetExceptionInfo(__e));
-}
-
-#endif // _LIBCPP_ABI_MICROSOFT
-// nested_exception
-
-class _LIBCPP_EXCEPTION_ABI nested_exception
-{
-    exception_ptr __ptr_;
-public:
-    nested_exception() _NOEXCEPT;
-//     nested_exception(const nested_exception&) noexcept = default;
-//     nested_exception& operator=(const nested_exception&) noexcept = default;
-    virtual ~nested_exception() _NOEXCEPT;
-
-    // access functions
-    _LIBCPP_NORETURN void rethrow_nested() const;
-    _LIBCPP_INLINE_VISIBILITY exception_ptr nested_ptr() const _NOEXCEPT {return __ptr_;}
-};
-
-template <class _Tp>
-struct __nested
-    : public _Tp,
-      public nested_exception
-{
-    _LIBCPP_INLINE_VISIBILITY explicit __nested(const _Tp& __t) : _Tp(__t) {}
-};
-
-#ifndef _LIBCPP_NO_EXCEPTIONS
-template <class _Tp, class _Up, bool>
-struct __throw_with_nested;
-
-template <class _Tp, class _Up>
-struct __throw_with_nested<_Tp, _Up, true> {
-    _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
-#ifndef _LIBCPP_CXX03_LANG
-    __do_throw(_Tp&& __t)
-#else
-    __do_throw (_Tp& __t)
-#endif  // _LIBCPP_CXX03_LANG
-    {
-        throw __nested<_Up>(_VSTD::forward<_Tp>(__t));
-    }
-};
-
-template <class _Tp, class _Up>
-struct __throw_with_nested<_Tp, _Up, false> {
-    _LIBCPP_NORETURN static inline _LIBCPP_INLINE_VISIBILITY void
-#ifndef _LIBCPP_CXX03_LANG
-    __do_throw(_Tp&& __t)
-#else
-    __do_throw (_Tp& __t)
-#endif  // _LIBCPP_CXX03_LANG
-    {
-        throw _VSTD::forward<_Tp>(__t);
-    }
-};
-#endif
-
-template <class _Tp>
-_LIBCPP_NORETURN
-void
-#ifndef _LIBCPP_CXX03_LANG
-throw_with_nested(_Tp&& __t)
-#else
-throw_with_nested (_Tp& __t)
-#endif // _LIBCPP_CXX03_LANG
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    typedef typename decay<_Tp>::type _Up;
-    static_assert( is_copy_constructible<_Up>::value, "type thrown must be CopyConstructible");
-    __throw_with_nested<_Tp, _Up,
-        is_class<_Up>::value &&
-        !is_base_of<nested_exception, _Up>::value &&
-        !__libcpp_is_final<_Up>::value>::
-            __do_throw(_VSTD::forward<_Tp>(__t));
-#else
-    ((void)__t);
-    // FIXME: Make this abort
-#endif
-}
-
-template <class _From, class _To>
-struct __can_dynamic_cast : public _LIBCPP_BOOL_CONSTANT(
-              is_polymorphic<_From>::value &&
-                 (!is_base_of<_To, _From>::value ||
-                   is_convertible<const _From*, const _To*>::value)) {};
-
-template <class _Ep>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-rethrow_if_nested(const _Ep& __e,
-                  typename enable_if< __can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
-{
-    const nested_exception* __nep = dynamic_cast<const nested_exception*>(_VSTD::addressof(__e));
-    if (__nep)
-        __nep->rethrow_nested();
-}
-
-template <class _Ep>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-rethrow_if_nested(const _Ep&,
-                  typename enable_if<!__can_dynamic_cast<_Ep, nested_exception>::value>::type* = 0)
-{
-}
-
-}  // std
-
-#endif  // _LIBCPP_EXCEPTION
diff --git a/lib/libcxx/include/experimental/__config b/lib/libcxx/include/experimental/__config
deleted file mode 100644
index c6f17762022..00000000000
--- a/lib/libcxx/include/experimental/__config
+++ /dev/null
@@ -1,74 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- __config ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_CONFIG
-#define _LIBCPP_EXPERIMENTAL_CONFIG
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL namespace std { namespace experimental {
-#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL  } }
-#define _VSTD_EXPERIMENTAL std::experimental
-
-#define _LIBCPP_BEGIN_NAMESPACE_LFTS _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace fundamentals_v1 {
-#define _LIBCPP_END_NAMESPACE_LFTS  } } }
-#define _VSTD_LFTS _VSTD_EXPERIMENTAL::fundamentals_v1
-
-#define _LIBCPP_BEGIN_NAMESPACE_LFTS_V2 _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace fundamentals_v2 {
-#define _LIBCPP_END_NAMESPACE_LFTS_V2  } } }
-#define _VSTD_LFTS_V2 _VSTD_EXPERIMENTAL::fundamentals_v2
-
-#define _LIBCPP_BEGIN_NAMESPACE_LFTS_PMR _LIBCPP_BEGIN_NAMESPACE_LFTS namespace pmr {
-#define _LIBCPP_END_NAMESPACE_LFTS_PMR _LIBCPP_END_NAMESPACE_LFTS }
-#define _VSTD_LFTS_PMR _VSTD_LFTS::pmr
-
-#define _LIBCPP_BEGIN_NAMESPACE_CHRONO_LFTS _LIBCPP_BEGIN_NAMESPACE_STD        \
-  namespace chrono { namespace experimental { inline namespace fundamentals_v1 {
-#define _LIBCPP_END_NAMESPACE_CHRONO_LFTS _LIBCPP_END_NAMESPACE_STD } } }
-
-#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FILESYSTEM \
-    _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL namespace filesystem { \
-    inline namespace v1 {
-
-#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL_FILESYSTEM \
-    } } _LIBCPP_END_NAMESPACE_EXPERIMENTAL
-
-#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_COROUTINES \
-  _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace coroutines_v1 {
-
-#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL_COROUTINES \
-  } _LIBCPP_END_NAMESPACE_EXPERIMENTAL
-
-#define _VSTD_CORO _VSTD_EXPERIMENTAL::coroutines_v1
-
-#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD \
-    _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL inline namespace parallelism_v2 {
-
-#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD \
-    } _LIBCPP_END_NAMESPACE_EXPERIMENTAL
-
-#define _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD_ABI \
-    _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD namespace simd_abi {
-
-#define _LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD_ABI \
-    } _LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD
-
-// TODO: support more targets
-#if defined(__AVX__)
-#define _LIBCPP_NATIVE_SIMD_WIDTH_IN_BYTES 32
-#else
-#define _LIBCPP_NATIVE_SIMD_WIDTH_IN_BYTES 16
-#endif
-
-#endif
diff --git a/lib/libcxx/include/experimental/__memory b/lib/libcxx/include/experimental/__memory
deleted file mode 100644
index 229fea605bf..00000000000
--- a/lib/libcxx/include/experimental/__memory
+++ /dev/null
@@ -1,90 +0,0 @@
-// -*- C++ -*-
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL___MEMORY
-#define _LIBCPP_EXPERIMENTAL___MEMORY
-
-#include <experimental/__config>
-#include <experimental/utility> // for erased_type
-#include <__functional_base>
-#include <type_traits>
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS
-
-template <
-    class _Tp, class _Alloc
-  , bool = uses_allocator<_Tp, _Alloc>::value
-  , bool = __has_allocator_type<_Tp>::value
-  >
-struct __lfts_uses_allocator : public false_type {};
-
-template <class _Tp, class _Alloc>
-struct __lfts_uses_allocator<_Tp, _Alloc, false, false> : public false_type {};
-
-template <class _Tp, class _Alloc, bool HasAlloc>
-struct __lfts_uses_allocator<_Tp, _Alloc, true, HasAlloc> : public true_type {};
-
-template <class _Tp, class _Alloc>
-struct __lfts_uses_allocator<_Tp, _Alloc, false, true>
-  : public integral_constant<bool
-    , is_convertible<_Alloc, typename _Tp::allocator_type>::value
-      || is_same<erased_type, typename _Tp::allocator_type>::value
-    >
-{};
-
-template <bool _UsesAlloc, class _Tp, class _Alloc, class ..._Args>
-struct __lfts_uses_alloc_ctor_imp
-{
-    static const int value = 0;
-};
-
-template <class _Tp, class _Alloc, class ..._Args>
-struct __lfts_uses_alloc_ctor_imp<true, _Tp, _Alloc, _Args...>
-{
-    static const bool __ic_first
-        = is_constructible<_Tp, allocator_arg_t, _Alloc, _Args...>::value;
-
-    static const bool __ic_second =
-        conditional<
-            __ic_first,
-            false_type,
-            is_constructible<_Tp, _Args..., _Alloc>
-        >::type::value;
-
-    static_assert(__ic_first || __ic_second,
-                  "Request for uses allocator construction is ill-formed");
-
-    static const int value = __ic_first ? 1 : 2;
-};
-
-template <class _Tp, class _Alloc, class ..._Args>
-struct __lfts_uses_alloc_ctor
-  : integral_constant<int,
-        __lfts_uses_alloc_ctor_imp<
-            __lfts_uses_allocator<_Tp, _Alloc>::value
-          , _Tp, _Alloc, _Args...
-        >::value
-    >
-{};
-
-template <class _Tp, class _Alloc, class ..._Args>
-inline _LIBCPP_INLINE_VISIBILITY
-void __lfts_user_alloc_construct(
-    _Tp * __store, const _Alloc & __a, _Args &&... __args)
-{
-    _VSTD::__user_alloc_construct_impl(
-        typename __lfts_uses_alloc_ctor<_Tp, _Alloc, _Args...>::type()
-       , __store, __a, _VSTD::forward<_Args>(__args)...
-       );
-}
-
-_LIBCPP_END_NAMESPACE_LFTS
-
-#endif /* _LIBCPP_EXPERIMENTAL___MEMORY */
diff --git a/lib/libcxx/include/experimental/algorithm b/lib/libcxx/include/experimental/algorithm
deleted file mode 100644
index eb3bad6ef98..00000000000
--- a/lib/libcxx/include/experimental/algorithm
+++ /dev/null
@@ -1,60 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- algorithm ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_ALGORITHM
-#define _LIBCPP_EXPERIMENTAL_ALGORITHM
-
-/*
-   experimental/algorithm synopsis
-
-#include <algorithm>
-
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-
-template <class ForwardIterator, class Searcher>
-ForwardIterator search(ForwardIterator first, ForwardIterator last,
-                       const Searcher &searcher);
-
-// sample removed because it's now part of C++17
-
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
-*/
-
-#include <experimental/__config>
-#include <algorithm>
-#include <type_traits>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS
-
-template <class _ForwardIterator, class _Searcher>
-_LIBCPP_INLINE_VISIBILITY
-_ForwardIterator search(_ForwardIterator __f, _ForwardIterator __l, const _Searcher &__s)
-{ return __s(__f, __l).first; }
-
-_LIBCPP_END_NAMESPACE_LFTS
-
-_LIBCPP_POP_MACROS
-
-#endif /* _LIBCPP_EXPERIMENTAL_ALGORITHM */
diff --git a/lib/libcxx/include/experimental/any b/lib/libcxx/include/experimental/any
deleted file mode 100644
index d9c95342589..00000000000
--- a/lib/libcxx/include/experimental/any
+++ /dev/null
@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===------------------------------- any ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_ANY
-#define _LIBCPP_EXPERIMENTAL_ANY
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/any> has been removed. Use <any> instead.")
-#else
-# warning "<experimental/any> has been removed. Use <any> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_ANY
diff --git a/lib/libcxx/include/experimental/chrono b/lib/libcxx/include/experimental/chrono
deleted file mode 100644
index 30c7e4a9d5a..00000000000
--- a/lib/libcxx/include/experimental/chrono
+++ /dev/null
@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- chrono ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_CHRONO
-#define _LIBCPP_EXPERIMENTAL_CHRONO
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/chrono> has been removed. Use <chrono> instead.")
-#else
-# warning "<experimental/chrono> has been removed. Use <chrono> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_CHRONO
diff --git a/lib/libcxx/include/experimental/coroutine b/lib/libcxx/include/experimental/coroutine
deleted file mode 100644
index 7cb39b81b48..00000000000
--- a/lib/libcxx/include/experimental/coroutine
+++ /dev/null
@@ -1,336 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- coroutine -----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_COROUTINE
-#define _LIBCPP_EXPERIMENTAL_COROUTINE
-
-/**
-    experimental/coroutine synopsis
-
-// C++next
-
-namespace std {
-namespace experimental {
-inline namespace coroutines_v1 {
-
-  // 18.11.1 coroutine traits
-template <typename R, typename... ArgTypes>
-class coroutine_traits;
-// 18.11.2 coroutine handle
-template <typename Promise = void>
-class coroutine_handle;
-// 18.11.2.7 comparison operators:
-bool operator==(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
-bool operator!=(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
-bool operator<(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
-bool operator<=(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
-bool operator>=(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
-bool operator>(coroutine_handle<> x, coroutine_handle<> y) _NOEXCEPT;
-// 18.11.3 trivial awaitables
-struct suspend_never;
-struct suspend_always;
-// 18.11.2.8 hash support:
-template <class T> struct hash;
-template <class P> struct hash<coroutine_handle<P>>;
-
-} // namespace coroutines_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <new>
-#include <type_traits>
-#include <functional>
-#include <memory> // for hash<T*>
-#include <cstddef>
-#include <cassert>
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef _LIBCPP_HAS_NO_COROUTINES
-# if defined(_LIBCPP_WARNING)
-    _LIBCPP_WARNING("<experimental/coroutine> cannot be used with this compiler")
-# else
-#   warning <experimental/coroutine> cannot be used with this compiler
-# endif
-#endif
-
-#ifndef _LIBCPP_HAS_NO_COROUTINES
-
-_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_COROUTINES
-
-template <class _Tp, class = void>
-struct __coroutine_traits_sfinae {};
-
-template <class _Tp>
-struct __coroutine_traits_sfinae<
-    _Tp, typename __void_t<typename _Tp::promise_type>::type>
-{
-  using promise_type = typename _Tp::promise_type;
-};
-
-template <typename _Ret, typename... _Args>
-struct _LIBCPP_TEMPLATE_VIS coroutine_traits
-    : public __coroutine_traits_sfinae<_Ret>
-{
-};
-
-template <typename _Promise = void>
-class _LIBCPP_TEMPLATE_VIS coroutine_handle;
-
-template <>
-class _LIBCPP_TEMPLATE_VIS coroutine_handle<void> {
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR coroutine_handle() _NOEXCEPT : __handle_(nullptr) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR coroutine_handle(nullptr_t) _NOEXCEPT : __handle_(nullptr) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    coroutine_handle& operator=(nullptr_t) _NOEXCEPT {
-        __handle_ = nullptr;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR void* address() const _NOEXCEPT { return __handle_; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR explicit operator bool() const _NOEXCEPT { return __handle_; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()() { resume(); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void resume() {
-      _LIBCPP_ASSERT(__is_suspended(),
-                     "resume() can only be called on suspended coroutines");
-      _LIBCPP_ASSERT(!done(),
-                "resume() has undefined behavior when the coroutine is done");
-      __builtin_coro_resume(__handle_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void destroy() {
-      _LIBCPP_ASSERT(__is_suspended(),
-                     "destroy() can only be called on suspended coroutines");
-      __builtin_coro_destroy(__handle_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool done() const {
-      _LIBCPP_ASSERT(__is_suspended(),
-                     "done() can only be called on suspended coroutines");
-      return __builtin_coro_done(__handle_);
-    }
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    static coroutine_handle from_address(void* __addr) _NOEXCEPT {
-        coroutine_handle __tmp;
-        __tmp.__handle_ = __addr;
-        return __tmp;
-    }
-
-    // FIXME: Should from_address(nullptr) be allowed?
-    _LIBCPP_INLINE_VISIBILITY
-    static coroutine_handle from_address(nullptr_t) _NOEXCEPT {
-      return coroutine_handle(nullptr);
-    }
-
-    template <class _Tp, bool _CallIsValid = false>
-    static coroutine_handle from_address(_Tp*) {
-      static_assert(_CallIsValid,
-       "coroutine_handle<void>::from_address cannot be called with "
-        "non-void pointers");
-    }
-
-private:
-  bool __is_suspended() const _NOEXCEPT  {
-    // FIXME actually implement a check for if the coro is suspended.
-    return __handle_;
-  }
-
-  template <class _PromiseT> friend class coroutine_handle;
-  void* __handle_;
-};
-
-// 18.11.2.7 comparison operators:
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
-    return __x.address() == __y.address();
-}
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
-    return !(__x == __y);
-}
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator<(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
-    return less<void*>()(__x.address(), __y.address());
-}
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator>(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
-    return __y < __x;
-}
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator<=(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
-    return !(__x > __y);
-}
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator>=(coroutine_handle<> __x, coroutine_handle<> __y) _NOEXCEPT {
-    return !(__x < __y);
-}
-
-template <typename _Promise>
-class _LIBCPP_TEMPLATE_VIS coroutine_handle : public coroutine_handle<> {
-    using _Base = coroutine_handle<>;
-public:
-#ifndef _LIBCPP_CXX03_LANG
-    // 18.11.2.1 construct/reset
-    using coroutine_handle<>::coroutine_handle;
-#else
-    _LIBCPP_INLINE_VISIBILITY coroutine_handle() _NOEXCEPT : _Base() {}
-    _LIBCPP_INLINE_VISIBILITY coroutine_handle(nullptr_t) _NOEXCEPT : _Base(nullptr) {}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    coroutine_handle& operator=(nullptr_t) _NOEXCEPT {
-        _Base::operator=(nullptr);
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Promise& promise() const {
-        return *static_cast<_Promise*>(
-            __builtin_coro_promise(this->__handle_, _LIBCPP_ALIGNOF(_Promise), false));
-    }
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    static coroutine_handle from_address(void* __addr) _NOEXCEPT {
-        coroutine_handle __tmp;
-        __tmp.__handle_ = __addr;
-        return __tmp;
-    }
-
-    // NOTE: this overload isn't required by the standard but is needed so
-    // the deleted _Promise* overload doesn't make from_address(nullptr)
-    // ambiguous.
-    // FIXME: should from_address work with nullptr?
-    _LIBCPP_INLINE_VISIBILITY
-    static coroutine_handle from_address(nullptr_t) _NOEXCEPT {
-      return coroutine_handle(nullptr);
-    }
-
-    template <class _Tp, bool _CallIsValid = false>
-    static coroutine_handle from_address(_Tp*) {
-      static_assert(_CallIsValid,
-       "coroutine_handle<promise_type>::from_address cannot be called with "
-        "non-void pointers");
-    }
-
-    template <bool _CallIsValid = false>
-    static coroutine_handle from_address(_Promise*) {
-      static_assert(_CallIsValid,
-       "coroutine_handle<promise_type>::from_address cannot be used with "
-        "pointers to the coroutine's promise type; use 'from_promise' instead");
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static coroutine_handle from_promise(_Promise& __promise) _NOEXCEPT {
-        typedef typename remove_cv<_Promise>::type _RawPromise;
-        coroutine_handle __tmp;
-        __tmp.__handle_ = __builtin_coro_promise(
-            _VSTD::addressof(const_cast<_RawPromise&>(__promise)),
-             _LIBCPP_ALIGNOF(_Promise), true);
-        return __tmp;
-    }
-};
-
-#if __has_builtin(__builtin_coro_noop)
-struct noop_coroutine_promise {};
-
-template <>
-class _LIBCPP_TEMPLATE_VIS coroutine_handle<noop_coroutine_promise>
-    : public coroutine_handle<> {
-  using _Base = coroutine_handle<>;
-  using _Promise = noop_coroutine_promise;
-public:
-
-  _LIBCPP_INLINE_VISIBILITY
-  _Promise& promise() const {
-    return *static_cast<_Promise*>(
-      __builtin_coro_promise(this->__handle_, _LIBCPP_ALIGNOF(_Promise), false));
-  }
-
-  _LIBCPP_CONSTEXPR explicit operator bool() const _NOEXCEPT { return true; }
-  _LIBCPP_CONSTEXPR bool done() const _NOEXCEPT { return false; }
-
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 void operator()() const _NOEXCEPT {}
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 void resume() const _NOEXCEPT {}
-  _LIBCPP_CONSTEXPR_AFTER_CXX17 void destroy() const _NOEXCEPT {}
-
-private:
-  _LIBCPP_INLINE_VISIBILITY
-  friend coroutine_handle<noop_coroutine_promise> noop_coroutine() _NOEXCEPT;
-
-  _LIBCPP_INLINE_VISIBILITY coroutine_handle() _NOEXCEPT {
-    this->__handle_ = __builtin_coro_noop();
-  }
-};
-
-using noop_coroutine_handle = coroutine_handle<noop_coroutine_promise>;
-
-inline _LIBCPP_INLINE_VISIBILITY
-noop_coroutine_handle noop_coroutine() _NOEXCEPT {
-  return noop_coroutine_handle();
-}
-#endif // __has_builtin(__builtin_coro_noop)
-
-struct _LIBCPP_TYPE_VIS suspend_never {
-  _LIBCPP_INLINE_VISIBILITY
-  bool await_ready() const _NOEXCEPT { return true; }
-  _LIBCPP_INLINE_VISIBILITY
-  void await_suspend(coroutine_handle<>) const _NOEXCEPT {}
-  _LIBCPP_INLINE_VISIBILITY
-  void await_resume() const _NOEXCEPT {}
-};
-
-struct _LIBCPP_TYPE_VIS suspend_always {
-  _LIBCPP_INLINE_VISIBILITY
-  bool await_ready() const _NOEXCEPT { return false; }
-  _LIBCPP_INLINE_VISIBILITY
-  void await_suspend(coroutine_handle<>) const _NOEXCEPT {}
-  _LIBCPP_INLINE_VISIBILITY
-  void await_resume() const _NOEXCEPT {}
-};
-
-_LIBCPP_END_NAMESPACE_EXPERIMENTAL_COROUTINES
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp>
-struct hash<_VSTD_CORO::coroutine_handle<_Tp> > {
-    using __arg_type = _VSTD_CORO::coroutine_handle<_Tp>;
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(__arg_type const& __v) const _NOEXCEPT
-    {return hash<void*>()(__v.address());}
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // !defined(_LIBCPP_HAS_NO_COROUTINES)
-
-#endif /* _LIBCPP_EXPERIMENTAL_COROUTINE */
diff --git a/lib/libcxx/include/experimental/deque b/lib/libcxx/include/experimental/deque
deleted file mode 100644
index f8495743c1f..00000000000
--- a/lib/libcxx/include/experimental/deque
+++ /dev/null
@@ -1,47 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- deque ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_DEQUE
-#define _LIBCPP_EXPERIMENTAL_DEQUE
-/*
-    experimental/deque synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  template <class T>
-  using deque = std::deque<T,polymorphic_allocator<T>>;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <deque>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _ValueT>
-using deque = _VSTD::deque<_ValueT, polymorphic_allocator<_ValueT>>;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_DEQUE */
diff --git a/lib/libcxx/include/experimental/filesystem b/lib/libcxx/include/experimental/filesystem
deleted file mode 100644
index 28d8dcf4fc1..00000000000
--- a/lib/libcxx/include/experimental/filesystem
+++ /dev/null
@@ -1,257 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- filesystem -------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_FILESYSTEM
-#define _LIBCPP_EXPERIMENTAL_FILESYSTEM
-/*
-    filesystem synopsis
-
-    namespace std { namespace experimental { namespace filesystem { inline namespace v1 {
-
-    class path;
-
-    void swap(path& lhs, path& rhs) noexcept;
-    size_t hash_value(const path& p) noexcept;
-
-    bool operator==(const path& lhs, const path& rhs) noexcept;
-    bool operator!=(const path& lhs, const path& rhs) noexcept;
-    bool operator< (const path& lhs, const path& rhs) noexcept;
-    bool operator<=(const path& lhs, const path& rhs) noexcept;
-    bool operator> (const path& lhs, const path& rhs) noexcept;
-    bool operator>=(const path& lhs, const path& rhs) noexcept;
-
-    path operator/ (const path& lhs, const path& rhs);
-
-    // fs.path.io operators are friends of path.
-    template <class charT, class traits>
-    friend basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os, const path& p);
-
-    template <class charT, class traits>
-    friend basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is, path& p);
-
-    template <class Source>
-      path u8path(const Source& source);
-    template <class InputIterator>
-      path u8path(InputIterator first, InputIterator last);
-
-    class filesystem_error;
-    class directory_entry;
-
-    class directory_iterator;
-
-    // enable directory_iterator range-based for statements
-    directory_iterator begin(directory_iterator iter) noexcept;
-    directory_iterator end(const directory_iterator&) noexcept;
-
-    class recursive_directory_iterator;
-
-    // enable recursive_directory_iterator range-based for statements
-    recursive_directory_iterator begin(recursive_directory_iterator iter) noexcept;
-    recursive_directory_iterator end(const recursive_directory_iterator&) noexcept;
-
-    class file_status;
-
-    struct space_info
-    {
-      uintmax_t capacity;
-      uintmax_t free;
-      uintmax_t available;
-    };
-
-    enum class file_type;
-    enum class perms;
-    enum class perm_options;
-    enum class copy_options;
-    enum class directory_options;
-
-    typedef chrono::time_point<trivial-clock>  file_time_type;
-
-    // operational functions
-
-    path absolute(const path& p);
-    path absolute(const path& p, error_code &ec);
-
-    path canonical(const path& p);
-    path canonical(const path& p, error_code& ec);
-
-    void copy(const path& from, const path& to);
-    void copy(const path& from, const path& to, error_code& ec);
-    void copy(const path& from, const path& to, copy_options options);
-    void copy(const path& from, const path& to, copy_options options,
-                   error_code& ec);
-
-    bool copy_file(const path& from, const path& to);
-    bool copy_file(const path& from, const path& to, error_code& ec);
-    bool copy_file(const path& from, const path& to, copy_options option);
-    bool copy_file(const path& from, const path& to, copy_options option,
-                           error_code& ec);
-
-    void copy_symlink(const path& existing_symlink, const path& new_symlink);
-    void copy_symlink(const path& existing_symlink, const path& new_symlink,
-                              error_code& ec) noexcept;
-
-    bool create_directories(const path& p);
-    bool create_directories(const path& p, error_code& ec);
-
-    bool create_directory(const path& p);
-    bool create_directory(const path& p, error_code& ec) noexcept;
-
-    bool create_directory(const path& p, const path& attributes);
-    bool create_directory(const path& p, const path& attributes,
-                                  error_code& ec) noexcept;
-
-    void create_directory_symlink(const path& to, const path& new_symlink);
-    void create_directory_symlink(const path& to, const path& new_symlink,
-                                          error_code& ec) noexcept;
-
-    void create_hard_link(const path& to, const path& new_hard_link);
-    void create_hard_link(const path& to, const path& new_hard_link,
-                                  error_code& ec) noexcept;
-
-    void create_symlink(const path& to, const path& new_symlink);
-    void create_symlink(const path& to, const path& new_symlink,
-                                error_code& ec) noexcept;
-
-    path current_path();
-    path current_path(error_code& ec);
-    void current_path(const path& p);
-    void current_path(const path& p, error_code& ec) noexcept;
-
-    bool exists(file_status s) noexcept;
-    bool exists(const path& p);
-    bool exists(const path& p, error_code& ec) noexcept;
-
-    bool equivalent(const path& p1, const path& p2);
-    bool equivalent(const path& p1, const path& p2, error_code& ec) noexcept;
-
-    uintmax_t    file_size(const path& p);
-    uintmax_t    file_size(const path& p, error_code& ec) noexcept;
-
-    uintmax_t    hard_link_count(const path& p);
-    uintmax_t    hard_link_count(const path& p, error_code& ec) noexcept;
-
-    bool is_block_file(file_status s) noexcept;
-    bool is_block_file(const path& p);
-    bool is_block_file(const path& p, error_code& ec) noexcept;
-
-    bool is_character_file(file_status s) noexcept;
-    bool is_character_file(const path& p);
-    bool is_character_file(const path& p, error_code& ec) noexcept;
-
-    bool is_directory(file_status s) noexcept;
-    bool is_directory(const path& p);
-    bool is_directory(const path& p, error_code& ec) noexcept;
-
-    bool is_empty(const path& p);
-    bool is_empty(const path& p, error_code& ec) noexcept;
-
-    bool is_fifo(file_status s) noexcept;
-    bool is_fifo(const path& p);
-    bool is_fifo(const path& p, error_code& ec) noexcept;
-
-    bool is_other(file_status s) noexcept;
-    bool is_other(const path& p);
-    bool is_other(const path& p, error_code& ec) noexcept;
-
-    bool is_regular_file(file_status s) noexcept;
-    bool is_regular_file(const path& p);
-    bool is_regular_file(const path& p, error_code& ec) noexcept;
-
-    bool is_socket(file_status s) noexcept;
-    bool is_socket(const path& p);
-    bool is_socket(const path& p, error_code& ec) noexcept;
-
-    bool is_symlink(file_status s) noexcept;
-    bool is_symlink(const path& p);
-    bool is_symlink(const path& p, error_code& ec) noexcept;
-
-    file_time_type  last_write_time(const path& p);
-    file_time_type  last_write_time(const path& p, error_code& ec) noexcept;
-    void last_write_time(const path& p, file_time_type new_time);
-    void last_write_time(const path& p, file_time_type new_time,
-                                 error_code& ec) noexcept;
-
-    void permissions(const path& p, perms prms,
-                     perm_options opts=perm_options::replace);
-    void permissions(const path& p, perms prms, error_code& ec) noexcept;
-    void permissions(const path& p, perms prms, perm_options opts,
-                     error_code& ec);
-
-    path proximate(const path& p, error_code& ec);
-    path proximate(const path& p, const path& base = current_path());
-    path proximate(const path& p, const path& base, error_code &ec);
-
-    path read_symlink(const path& p);
-    path read_symlink(const path& p, error_code& ec);
-
-    path relative(const path& p, error_code& ec);
-    path relative(const path& p, const path& base=current_path());
-    path relative(const path& p, const path& base, error_code& ec);
-
-    bool remove(const path& p);
-    bool remove(const path& p, error_code& ec) noexcept;
-
-    uintmax_t    remove_all(const path& p);
-    uintmax_t    remove_all(const path& p, error_code& ec);
-
-    void rename(const path& from, const path& to);
-    void rename(const path& from, const path& to, error_code& ec) noexcept;
-
-    void resize_file(const path& p, uintmax_t size);
-    void resize_file(const path& p, uintmax_t size, error_code& ec) noexcept;
-
-    space_info   space(const path& p);
-    space_info   space(const path& p, error_code& ec) noexcept;
-
-    file_status  status(const path& p);
-    file_status  status(const path& p, error_code& ec) noexcept;
-
-    bool status_known(file_status s) noexcept;
-
-    file_status  symlink_status(const path& p);
-    file_status  symlink_status(const path& p, error_code& ec) noexcept;
-
-    path temp_directory_path();
-    path temp_directory_path(error_code& ec);
-
-    path weakly_canonical(path const& p);
-    path weakly_canonical(path const& p, error_code& ec);
-
-
-} } } }  // namespaces std::experimental::filesystem::v1
-
-*/
-
-#include <experimental/__config>
-#include <filesystem>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-#ifndef _LIBCPP_CXX03_LANG
-
-#define __cpp_lib_experimental_filesystem 201406
-
-_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FILESYSTEM
-
-using namespace _VSTD_FS;
-
-_LIBCPP_END_NAMESPACE_EXPERIMENTAL_FILESYSTEM
-
-#endif // !_LIBCPP_CXX03_LANG
-
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_EXPERIMENTAL_FILESYSTEM
diff --git a/lib/libcxx/include/experimental/forward_list b/lib/libcxx/include/experimental/forward_list
deleted file mode 100644
index 55e195f446f..00000000000
--- a/lib/libcxx/include/experimental/forward_list
+++ /dev/null
@@ -1,47 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- forward_list -----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_FORWARD_LIST
-#define _LIBCPP_EXPERIMENTAL_FORWARD_LIST
-/*
-    experimental/forward_list synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  template <class T>
-  using forward_list = std::forward_list<T,polymorphic_allocator<T>>;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <forward_list>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _ValueT>
-using forward_list = _VSTD::forward_list<_ValueT, polymorphic_allocator<_ValueT>>;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_FORWARD_LIST */
diff --git a/lib/libcxx/include/experimental/functional b/lib/libcxx/include/experimental/functional
deleted file mode 100644
index f63dfb07bb0..00000000000
--- a/lib/libcxx/include/experimental/functional
+++ /dev/null
@@ -1,462 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- functional --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_FUNCTIONAL
-#define _LIBCPP_EXPERIMENTAL_FUNCTIONAL
-
-/*
-   experimental/functional synopsis
-
-#include <algorithm>
-
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-
-    // See C++14 20.9.9, Function object binders
-    template <class T> constexpr bool is_bind_expression_v
-      = is_bind_expression<T>::value;
-    template <class T> constexpr int is_placeholder_v
-      = is_placeholder<T>::value;
-
-    // 4.2, Class template function
-    template<class> class function; // undefined
-    template<class R, class... ArgTypes> class function<R(ArgTypes...)>;
-
-    template<class R, class... ArgTypes>
-    void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&);
-
-    template<class R, class... ArgTypes>
-    bool operator==(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
-    template<class R, class... ArgTypes>
-    bool operator==(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
-    template<class R, class... ArgTypes>
-    bool operator!=(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
-    template<class R, class... ArgTypes>
-    bool operator!=(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
-
-    // 4.3, Searchers
-    template<class ForwardIterator, class BinaryPredicate = equal_to<>>
-      class default_searcher;
-
-    template<class RandomAccessIterator,
-             class Hash = hash<typename iterator_traits<RandomAccessIterator>::value_type>,
-             class BinaryPredicate = equal_to<>>
-      class boyer_moore_searcher;
-
-    template<class RandomAccessIterator,
-             class Hash = hash<typename iterator_traits<RandomAccessIterator>::value_type>,
-             class BinaryPredicate = equal_to<>>
-      class boyer_moore_horspool_searcher;
-
-    template<class ForwardIterator, class BinaryPredicate = equal_to<>>
-    default_searcher<ForwardIterator, BinaryPredicate>
-    make_default_searcher(ForwardIterator pat_first, ForwardIterator pat_last,
-                          BinaryPredicate pred = BinaryPredicate());
-
-    template<class RandomAccessIterator,
-             class Hash = hash<typename iterator_traits<RandomAccessIterator>::value_type>,
-             class BinaryPredicate = equal_to<>>
-    boyer_moore_searcher<RandomAccessIterator, Hash, BinaryPredicate>
-    make_boyer_moore_searcher(
-        RandomAccessIterator pat_first, RandomAccessIterator pat_last,
-        Hash hf = Hash(), BinaryPredicate pred = BinaryPredicate());
-
-    template<class RandomAccessIterator,
-             class Hash = hash<typename iterator_traits<RandomAccessIterator>::value_type>,
-             class BinaryPredicate = equal_to<>>
-    boyer_moore_horspool_searcher<RandomAccessIterator, Hash, BinaryPredicate>
-    make_boyer_moore_horspool_searcher(
-        RandomAccessIterator pat_first, RandomAccessIterator pat_last,
-        Hash hf = Hash(), BinaryPredicate pred = BinaryPredicate());
-
-  } // namespace fundamentals_v1
-  } // namespace experimental
-
-  template<class R, class... ArgTypes, class Alloc>
-  struct uses_allocator<experimental::function<R(ArgTypes...)>, Alloc>;
-
-} // namespace std
-
-*/
-
-#include <experimental/__config>
-#include <functional>
-#include <algorithm>
-#include <type_traits>
-#include <vector>
-#include <array>
-#include <unordered_map>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS
-
-#if _LIBCPP_STD_VER > 11
-// default searcher
-template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
-_LIBCPP_TYPE_VIS
-class default_searcher {
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    default_searcher(_ForwardIterator __f, _ForwardIterator __l, 
-                       _BinaryPredicate __p = _BinaryPredicate())
-        : __first_(__f), __last_(__l), __pred_(__p) {}
-
-    template <typename _ForwardIterator2>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<_ForwardIterator2, _ForwardIterator2>
-    operator () (_ForwardIterator2 __f, _ForwardIterator2 __l) const
-    {
-        return _VSTD::__search(__f, __l, __first_, __last_, __pred_,
-            typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category(),
-            typename _VSTD::iterator_traits<_ForwardIterator2>::iterator_category());
-    }
-
-private:
-    _ForwardIterator __first_;
-    _ForwardIterator __last_;
-    _BinaryPredicate __pred_;
-    };
-
-template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
-_LIBCPP_INLINE_VISIBILITY
-default_searcher<_ForwardIterator, _BinaryPredicate>
-make_default_searcher( _ForwardIterator __f, _ForwardIterator __l, _BinaryPredicate __p = _BinaryPredicate ())
-{
-    return default_searcher<_ForwardIterator, _BinaryPredicate>(__f, __l, __p);
-}
-
-template<class _Key, class _Value, class _Hash, class _BinaryPredicate, bool /*useArray*/> class _BMSkipTable;
-
-//  General case for BM data searching; use a map
-template<class _Key, typename _Value, class _Hash, class _BinaryPredicate>
-class _BMSkipTable<_Key, _Value, _Hash, _BinaryPredicate, false> {
-public: // TODO private:
-    typedef _Value value_type;
-    typedef _Key   key_type;
-
-    const _Value __default_value_;
-    std::unordered_map<_Key, _Value, _Hash, _BinaryPredicate> __table;
-    
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    _BMSkipTable(std::size_t __sz, _Value __default, _Hash __hf, _BinaryPredicate __pred)
-        : __default_value_(__default), __table(__sz, __hf, __pred) {}
-    
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(const key_type &__key, value_type __val)
-    {
-        __table [__key] = __val;    // Would skip_.insert (val) be better here?
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type operator [](const key_type & __key) const
-    {
-        auto __it = __table.find (__key);
-        return __it == __table.end() ? __default_value_ : __it->second;
-    }
-};
-    
-
-//  Special case small numeric values; use an array
-template<class _Key, typename _Value, class _Hash, class _BinaryPredicate>
-class _BMSkipTable<_Key, _Value, _Hash, _BinaryPredicate, true> {
-private:
-    typedef _Value value_type;
-    typedef _Key   key_type;
-
-    typedef typename std::make_unsigned<key_type>::type unsigned_key_type;
-    typedef std::array<value_type, _VSTD::numeric_limits<unsigned_key_type>::max()> skip_map;
-    skip_map __table;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    _BMSkipTable(std::size_t /*__sz*/, _Value __default, _Hash /*__hf*/, _BinaryPredicate /*__pred*/)
-    {
-        std::fill_n(__table.begin(), __table.size(), __default);
-    }
-    
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(key_type __key, value_type __val)
-    {
-        __table[static_cast<unsigned_key_type>(__key)] = __val;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type operator [](key_type __key) const
-    {
-        return __table[static_cast<unsigned_key_type>(__key)];
-    }
-};
-
-
-template <class _RandomAccessIterator1, 
-          class _Hash = hash<typename iterator_traits<_RandomAccessIterator1>::value_type>, 
-          class _BinaryPredicate = equal_to<>>
-_LIBCPP_TYPE_VIS
-class boyer_moore_searcher {
-private:
-    typedef typename std::iterator_traits<_RandomAccessIterator1>::difference_type difference_type;
-    typedef typename std::iterator_traits<_RandomAccessIterator1>::value_type      value_type;
-    typedef _BMSkipTable<value_type, difference_type, _Hash, _BinaryPredicate,
-                    _VSTD::is_integral<value_type>::value && // what about enums?
-                    sizeof(value_type) == 1 &&
-                    is_same<_Hash, hash<value_type>>::value &&
-                    is_same<_BinaryPredicate, equal_to<>>::value
-            > skip_table_type;
-    
-public:
-    boyer_moore_searcher(_RandomAccessIterator1 __f, _RandomAccessIterator1 __l, 
-                _Hash __hf = _Hash(), _BinaryPredicate __pred = _BinaryPredicate())
-            : __first_(__f), __last_(__l), __pred_(__pred),
-              __pattern_length_(_VSTD::distance(__first_, __last_)),
-              __skip_{make_shared<skip_table_type>(__pattern_length_, -1, __hf, __pred_)},
-              __suffix_{make_shared<vector<difference_type>>(__pattern_length_ + 1)}
-        {
-    //  build the skip table
-        for ( difference_type __i = 0; __f != __l; ++__f, (void) ++__i )
-            __skip_->insert(*__f, __i);
-
-        this->__build_suffix_table ( __first_, __last_, __pred_ );
-        }
-        
-    template <typename _RandomAccessIterator2>
-    pair<_RandomAccessIterator2, _RandomAccessIterator2>
-    operator ()(_RandomAccessIterator2 __f, _RandomAccessIterator2 __l) const
-    {
-        static_assert ( std::is_same<
-                typename std::__uncvref<typename std::iterator_traits<_RandomAccessIterator1>::value_type>::type, 
-                typename std::__uncvref<typename std::iterator_traits<_RandomAccessIterator2>::value_type>::type
-                    >::value,
-                "Corpus and Pattern iterators must point to the same type" );
-
-        if (__f      == __l )    return make_pair(__l, __l); // empty corpus
-        if (__first_ == __last_) return make_pair(__f, __f); // empty pattern
-
-    //  If the pattern is larger than the corpus, we can't find it!
-        if ( __pattern_length_ > _VSTD::distance (__f, __l)) 
-            return make_pair(__l, __l);
-
-    //  Do the search 
-        return this->__search(__f, __l);
-    }
-        
-public: // TODO private:
-    _RandomAccessIterator1               __first_;
-    _RandomAccessIterator1               __last_;
-    _BinaryPredicate                     __pred_;
-    difference_type                      __pattern_length_;
-    shared_ptr<skip_table_type>          __skip_;
-    shared_ptr<vector<difference_type>>  __suffix_;
-
-    template <typename _RandomAccessIterator2>
-    pair<_RandomAccessIterator2, _RandomAccessIterator2>
-    __search(_RandomAccessIterator2 __f, _RandomAccessIterator2 __l) const
-    {
-        _RandomAccessIterator2 __cur = __f;
-        const _RandomAccessIterator2 __last = __l - __pattern_length_;
-        const skip_table_type &         __skip   = *__skip_.get();
-        const vector<difference_type> & __suffix = *__suffix_.get();
-        
-        while (__cur <= __last)
-        {
-
-        //  Do we match right where we are?
-            difference_type __j = __pattern_length_;
-            while (__pred_(__first_ [__j-1], __cur [__j-1])) {
-                __j--;
-            //  We matched - we're done!
-                if ( __j == 0 )
-                    return make_pair(__cur, __cur + __pattern_length_);
-                }
-            
-        //  Since we didn't match, figure out how far to skip forward
-            difference_type __k = __skip[__cur [ __j - 1 ]];
-            difference_type __m = __j - __k - 1;
-            if (__k < __j && __m > __suffix[ __j ])
-                __cur += __m;
-            else
-                __cur += __suffix[ __j ];
-        }
-    
-        return make_pair(__l, __l);     // We didn't find anything
-    }
-
-
-    template<typename _Iterator, typename _Container>
-    void __compute_bm_prefix ( _Iterator __f, _Iterator __l, _BinaryPredicate __pred, _Container &__prefix )
-    {
-        const std::size_t __count = _VSTD::distance(__f, __l);
-                        
-        __prefix[0] = 0;
-        std::size_t __k = 0;
-        for ( std::size_t __i = 1; __i < __count; ++__i )
-        {
-            while ( __k > 0 && !__pred ( __f[__k], __f[__i] ))
-                __k = __prefix [ __k - 1 ];
-                
-            if ( __pred ( __f[__k], __f[__i] ))
-                __k++;
-            __prefix [ __i ] = __k;
-        }
-    }
-
-    void __build_suffix_table(_RandomAccessIterator1 __f, _RandomAccessIterator1 __l, 
-                                                    _BinaryPredicate __pred)
-    {
-        const std::size_t __count = _VSTD::distance(__f, __l);
-        vector<difference_type> & __suffix = *__suffix_.get();
-        if (__count > 0)
-        {
-            _VSTD::vector<value_type> __scratch(__count);
-            
-            __compute_bm_prefix(__f, __l, __pred, __scratch);
-            for ( std::size_t __i = 0; __i <= __count; __i++ )
-                __suffix[__i] = __count - __scratch[__count-1];
-    
-            typedef _VSTD::reverse_iterator<_RandomAccessIterator1> _RevIter;
-            __compute_bm_prefix(_RevIter(__l), _RevIter(__f), __pred, __scratch);
-     
-            for ( std::size_t __i = 0; __i < __count; __i++ )
-            {
-                const std::size_t     __j = __count - __scratch[__i];
-                const difference_type __k = __i     - __scratch[__i] + 1;
-     
-                if (__suffix[__j] > __k)
-                    __suffix[__j] = __k;
-            }
-        }
-    }
-
-};
-
-template<class _RandomAccessIterator, 
-         class _Hash = hash<typename iterator_traits<_RandomAccessIterator>::value_type>, 
-         class _BinaryPredicate = equal_to<>>
-_LIBCPP_INLINE_VISIBILITY
-boyer_moore_searcher<_RandomAccessIterator, _Hash, _BinaryPredicate>
-make_boyer_moore_searcher( _RandomAccessIterator __f, _RandomAccessIterator __l, 
-                    _Hash __hf = _Hash(), _BinaryPredicate __p = _BinaryPredicate ())
-{
-    return boyer_moore_searcher<_RandomAccessIterator, _Hash, _BinaryPredicate>(__f, __l, __hf, __p);
-}
-
-// boyer-moore-horspool
-template <class _RandomAccessIterator1, 
-          class _Hash = hash<typename iterator_traits<_RandomAccessIterator1>::value_type>, 
-          class _BinaryPredicate = equal_to<>>
-_LIBCPP_TYPE_VIS
-class boyer_moore_horspool_searcher {
-private:
-    typedef typename std::iterator_traits<_RandomAccessIterator1>::difference_type difference_type;
-    typedef typename std::iterator_traits<_RandomAccessIterator1>::value_type      value_type;
-    typedef _BMSkipTable<value_type, difference_type, _Hash, _BinaryPredicate,
-                    _VSTD::is_integral<value_type>::value && // what about enums?
-                    sizeof(value_type) == 1 &&
-                    is_same<_Hash, hash<value_type>>::value &&
-                    is_same<_BinaryPredicate, equal_to<>>::value
-            > skip_table_type;
-
-public:
-    boyer_moore_horspool_searcher(_RandomAccessIterator1 __f, _RandomAccessIterator1 __l, 
-                _Hash __hf = _Hash(), _BinaryPredicate __pred = _BinaryPredicate())
-            : __first_(__f), __last_(__l), __pred_(__pred),
-              __pattern_length_(_VSTD::distance(__first_, __last_)),
-              __skip_{_VSTD::make_shared<skip_table_type>(__pattern_length_, __pattern_length_, __hf, __pred_)}
-        {
-    //  build the skip table
-            if ( __f != __l )
-            {
-                __l = __l - 1;
-                for ( difference_type __i = 0; __f != __l; ++__f, (void) ++__i )
-                    __skip_->insert(*__f, __pattern_length_ - 1 - __i);
-            }
-        }
-            
-    template <typename _RandomAccessIterator2>
-    pair<_RandomAccessIterator2, _RandomAccessIterator2>
-    operator ()(_RandomAccessIterator2 __f, _RandomAccessIterator2 __l) const
-    {
-        static_assert ( std::is_same<
-                typename std::__uncvref<typename std::iterator_traits<_RandomAccessIterator1>::value_type>::type, 
-                typename std::__uncvref<typename std::iterator_traits<_RandomAccessIterator2>::value_type>::type
-                    >::value,
-                "Corpus and Pattern iterators must point to the same type" );
-
-        if (__f      == __l )    return make_pair(__l, __l); // empty corpus
-        if (__first_ == __last_) return make_pair(__f, __f); // empty pattern
-
-    //  If the pattern is larger than the corpus, we can't find it!
-        if ( __pattern_length_ > _VSTD::distance (__f, __l)) 
-            return make_pair(__l, __l);
-
-    //  Do the search 
-        return this->__search(__f, __l);
-    }
-        
-private:
-    _RandomAccessIterator1      __first_;
-    _RandomAccessIterator1      __last_;
-    _BinaryPredicate            __pred_;
-    difference_type             __pattern_length_;
-    shared_ptr<skip_table_type> __skip_;
-
-    template <typename _RandomAccessIterator2>
-    pair<_RandomAccessIterator2, _RandomAccessIterator2>
-    __search ( _RandomAccessIterator2 __f, _RandomAccessIterator2 __l ) const {
-        _RandomAccessIterator2 __cur = __f;
-        const _RandomAccessIterator2 __last = __l - __pattern_length_;
-        const skip_table_type & __skip = *__skip_.get();
-
-        while (__cur <= __last)
-        {
-        //  Do we match right where we are?
-            difference_type __j = __pattern_length_;
-            while (__pred_(__first_[__j-1], __cur[__j-1]))
-            {
-                __j--;
-            //  We matched - we're done!
-                if ( __j == 0 )
-                    return make_pair(__cur, __cur + __pattern_length_);
-            }
-            __cur += __skip[__cur[__pattern_length_-1]];
-        }
-        
-        return make_pair(__l, __l);
-    }
-};
-
-template<class _RandomAccessIterator, 
-         class _Hash = hash<typename iterator_traits<_RandomAccessIterator>::value_type>, 
-         class _BinaryPredicate = equal_to<>>
-_LIBCPP_INLINE_VISIBILITY
-boyer_moore_horspool_searcher<_RandomAccessIterator, _Hash, _BinaryPredicate>
-make_boyer_moore_horspool_searcher( _RandomAccessIterator __f, _RandomAccessIterator __l, 
-                    _Hash __hf = _Hash(), _BinaryPredicate __p = _BinaryPredicate ())
-{
-    return boyer_moore_horspool_searcher<_RandomAccessIterator, _Hash, _BinaryPredicate>(__f, __l, __hf, __p);
-}
-
-#endif // _LIBCPP_STD_VER > 11
-
-_LIBCPP_END_NAMESPACE_LFTS
-
-_LIBCPP_POP_MACROS
-
-#endif /* _LIBCPP_EXPERIMENTAL_FUNCTIONAL */
diff --git a/lib/libcxx/include/experimental/iterator b/lib/libcxx/include/experimental/iterator
deleted file mode 100644
index ea672e96631..00000000000
--- a/lib/libcxx/include/experimental/iterator
+++ /dev/null
@@ -1,114 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- iterator -------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_ITERATOR
-#define _LIBCPP_EXPERIMENTAL_ITERATOR
-
-/*
-namespace std {
-  namespace experimental {
-    inline namespace fundamentals_v2 {
-
-    template <class DelimT, class charT = char, class traits = char_traits<charT>>
-        class ostream_joiner {
-        public:
-         typedef charT                        char_type;
-         typedef traits                       traits_type;
-         typedef basic_ostream<charT, traits> ostream_type;
-         typedef output_iterator_tag          iterator_category;
-         typedef void                         value_type;
-         typedef void                         difference_type;
-         typedef void                         pointer;
-         typedef void                         reference;
-      
-         ostream_joiner(ostream_type& s, const DelimT& delimiter);
-         ostream_joiner(ostream_type& s, DelimT&& delimiter);
-
-         template<typename T>  
-         ostream_joiner& operator=(const T& value);
-
-         ostream_joiner& operator*() noexcept;
-         ostream_joiner& operator++() noexcept;
-         ostream_joiner& operator++(int) noexcept;
-   private:
-      ostream_type* out_stream;   // exposition only 
-      DelimT delim;               // exposition only 
-      bool first_element;         // exposition only
-   };
-
-  template <class charT, class traits, class DelimT>
-    ostream_joiner<decay_t<DelimT>, charT, traits>
-    make_ostream_joiner(basic_ostream<charT, traits>& os, DelimT&& delimiter);
-
-    } // inline namespace fundamentals_v2
-  } // namespace experimental
-} // namespace std
-
-*/
-
-#include <experimental/__config>
-
-#if _LIBCPP_STD_VER > 11
-
-#include <iterator>
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS
-
-template <class _Delim, class _CharT = char, class _Traits = char_traits<_CharT>>
-class ostream_joiner {
-public:
-
-    typedef _CharT                               char_type;
-    typedef _Traits                              traits_type;
-    typedef basic_ostream<char_type,traits_type> ostream_type;
-    typedef output_iterator_tag                  iterator_category;
-    typedef void                                 value_type;
-    typedef void                                 difference_type;
-    typedef void                                 pointer;
-    typedef void                                 reference;
-
-    ostream_joiner(ostream_type& __os, _Delim&& __d)
-        : __output_iter(_VSTD::addressof(__os)), __delim(_VSTD::move(__d)), __first(true) {}
-        
-    ostream_joiner(ostream_type& __os, const _Delim& __d)
-        : __output_iter(_VSTD::addressof(__os)), __delim(__d), __first(true) {}
-    
-
-    template<typename _Tp>
-    ostream_joiner& operator=(const _Tp& __v)
-    {
-        if (!__first)
-            *__output_iter << __delim;
-        __first = false;
-        *__output_iter << __v;
-        return *this;
-    }
-
-    ostream_joiner& operator*()     _NOEXCEPT { return *this; }
-    ostream_joiner& operator++()    _NOEXCEPT { return *this; }
-    ostream_joiner& operator++(int) _NOEXCEPT { return *this; }
-
-private:
-    ostream_type*   __output_iter;
-    _Delim          __delim;
-    bool            __first;
-};
-
-
-template <class _CharT, class _Traits, class _Delim>
-ostream_joiner<typename decay<_Delim>::type, _CharT, _Traits>
-make_ostream_joiner(basic_ostream<_CharT, _Traits>& __os, _Delim && __d)
-{ return ostream_joiner<typename decay<_Delim>::type, _CharT, _Traits>(__os, _VSTD::forward<_Delim>(__d)); }
-
-_LIBCPP_END_NAMESPACE_LFTS
-
-#endif /* _LIBCPP_STD_VER > 11 */
-
-#endif // _LIBCPP_EXPERIMENTAL_ITERATOR
diff --git a/lib/libcxx/include/experimental/list b/lib/libcxx/include/experimental/list
deleted file mode 100644
index 1678ee3e93c..00000000000
--- a/lib/libcxx/include/experimental/list
+++ /dev/null
@@ -1,47 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- list ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_LIST
-#define _LIBCPP_EXPERIMENTAL_LIST
-/*
-    experimental/list synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  template <class T>
-  using list = std::list<T,polymorphic_allocator<T>>;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <list>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _ValueT>
-using list = _VSTD::list<_ValueT, polymorphic_allocator<_ValueT>>;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_LIST */
diff --git a/lib/libcxx/include/experimental/map b/lib/libcxx/include/experimental/map
deleted file mode 100644
index cff2c5e52c0..00000000000
--- a/lib/libcxx/include/experimental/map
+++ /dev/null
@@ -1,57 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- map ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_MAP
-#define _LIBCPP_EXPERIMENTAL_MAP
-/*
-    experimental/map synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  template <class Key, class T, class Compare = less<Key>>
-  using map = std::map<Key, T, Compare,
-                       polymorphic_allocator<pair<const Key,T>>>;
-
-  template <class Key, class T, class Compare = less<Key>>
-  using multimap = std::multimap<Key, T, Compare,
-                                 polymorphic_allocator<pair<const Key,T>>>;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <map>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _Key, class _Value, class  _Compare = less<_Key>>
-using map = _VSTD::map<_Key, _Value, _Compare,
-                        polymorphic_allocator<pair<const _Key, _Value>>>;
-
-template <class _Key, class _Value, class  _Compare = less<_Key>>
-using multimap = _VSTD::multimap<_Key, _Value, _Compare,
-                        polymorphic_allocator<pair<const _Key, _Value>>>;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_MAP */
diff --git a/lib/libcxx/include/experimental/memory_resource b/lib/libcxx/include/experimental/memory_resource
deleted file mode 100644
index 83781d46203..00000000000
--- a/lib/libcxx/include/experimental/memory_resource
+++ /dev/null
@@ -1,427 +0,0 @@
-// -*- C++ -*-
-//===------------------------ memory_resource -----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_MEMORY_RESOURCE
-#define _LIBCPP_EXPERIMENTAL_MEMORY_RESOURCE
-
-/**
-    experimental/memory_resource synopsis
-
-// C++1y
-
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  class memory_resource;
-
-  bool operator==(const memory_resource& a,
-                  const memory_resource& b) noexcept;
-  bool operator!=(const memory_resource& a,
-                  const memory_resource& b) noexcept;
-
-  template <class Tp> class polymorphic_allocator;
-
-  template <class T1, class T2>
-  bool operator==(const polymorphic_allocator<T1>& a,
-                  const polymorphic_allocator<T2>& b) noexcept;
-  template <class T1, class T2>
-  bool operator!=(const polymorphic_allocator<T1>& a,
-                  const polymorphic_allocator<T2>& b) noexcept;
-
-  // The name resource_adaptor_imp is for exposition only.
-  template <class Allocator> class resource_adaptor_imp;
-
-  template <class Allocator>
-    using resource_adaptor = resource_adaptor_imp<
-      allocator_traits<Allocator>::rebind_alloc<char>>;
-
-  // Global memory resources
-  memory_resource* new_delete_resource() noexcept;
-  memory_resource* null_memory_resource() noexcept;
-
-  // The default memory resource
-  memory_resource* set_default_resource(memory_resource* r) noexcept;
-  memory_resource* get_default_resource() noexcept;
-
-  // Standard memory resources
-  struct pool_options;
-  class synchronized_pool_resource;
-  class unsynchronized_pool_resource;
-  class monotonic_buffer_resource;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <experimental/__memory>
-#include <limits>
-#include <memory>
-#include <new>
-#include <stdexcept>
-#include <__tuple>
-#include <type_traits>
-#include <utility>
-#include <cstddef>
-#include <cstdlib>
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-// Round __s up to next multiple of __a.
-inline _LIBCPP_INLINE_VISIBILITY
-size_t __aligned_allocation_size(size_t __s, size_t __a) _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s + __a > __s, "aligned allocation size overflows");
-    return (__s + __a - 1) & ~(__a - 1);
-}
-
-// 8.5, memory.resource
-class _LIBCPP_TYPE_VIS memory_resource
-{
-    static const size_t __max_align = _LIBCPP_ALIGNOF(max_align_t);
-
-// 8.5.2, memory.resource.public
-public:
-    virtual ~memory_resource() = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void* allocate(size_t __bytes, size_t __align = __max_align)
-        { return do_allocate(__bytes, __align); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void deallocate(void * __p, size_t __bytes, size_t __align = __max_align)
-        { do_deallocate(__p, __bytes, __align); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool is_equal(memory_resource const & __other) const _NOEXCEPT
-        { return do_is_equal(__other); }
-
-// 8.5.3, memory.resource.priv
-protected:
-    virtual void* do_allocate(size_t, size_t) = 0;
-    virtual void do_deallocate(void*, size_t, size_t) = 0;
-    virtual bool do_is_equal(memory_resource const &) const _NOEXCEPT = 0;
-};
-
-// 8.5.4, memory.resource.eq
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(memory_resource const & __lhs,
-                memory_resource const & __rhs) _NOEXCEPT
-{
-    return &__lhs == &__rhs || __lhs.is_equal(__rhs);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(memory_resource const & __lhs,
-                memory_resource const & __rhs) _NOEXCEPT
-{
-    return !(__lhs == __rhs);
-}
-
-_LIBCPP_FUNC_VIS
-memory_resource * new_delete_resource() _NOEXCEPT;
-
-_LIBCPP_FUNC_VIS
-memory_resource * null_memory_resource() _NOEXCEPT;
-
-_LIBCPP_FUNC_VIS
-memory_resource * get_default_resource() _NOEXCEPT;
-
-_LIBCPP_FUNC_VIS
-memory_resource * set_default_resource(memory_resource * __new_res) _NOEXCEPT;
-
-// 8.6, memory.polymorphic.allocator.class
-
-// 8.6.1, memory.polymorphic.allocator.overview
-template <class _ValueType>
-class _LIBCPP_TEMPLATE_VIS polymorphic_allocator
-{
-public:
-    typedef _ValueType value_type;
-
-    // 8.6.2, memory.polymorphic.allocator.ctor
-    _LIBCPP_INLINE_VISIBILITY
-    polymorphic_allocator() _NOEXCEPT
-      : __res_(_VSTD_LFTS_PMR::get_default_resource())
-    {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    polymorphic_allocator(memory_resource * __r) _NOEXCEPT
-      : __res_(__r)
-    {}
-
-    polymorphic_allocator(polymorphic_allocator const &) = default;
-
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY
-    polymorphic_allocator(polymorphic_allocator<_Tp> const & __other) _NOEXCEPT
-      : __res_(__other.resource())
-    {}
-
-    polymorphic_allocator &
-    operator=(polymorphic_allocator const &) = delete;
-
-    // 8.6.3, memory.polymorphic.allocator.mem
-    _LIBCPP_INLINE_VISIBILITY
-    _ValueType* allocate(size_t __n) {
-        if (__n > __max_size()) {
-            __throw_length_error(
-                "std::experimental::pmr::polymorphic_allocator<T>::allocate(size_t n)"
-                " 'n' exceeds maximum supported size");
-        }
-        return static_cast<_ValueType*>(
-            __res_->allocate(__n * sizeof(_ValueType), _LIBCPP_ALIGNOF(_ValueType))
-        );
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void deallocate(_ValueType * __p, size_t __n) _NOEXCEPT {
-        _LIBCPP_ASSERT(__n <= __max_size(),
-                       "deallocate called for size which exceeds max_size()");
-        __res_->deallocate(__p, __n * sizeof(_ValueType), _LIBCPP_ALIGNOF(_ValueType));
-    }
-
-    template <class _Tp, class ..._Ts>
-    _LIBCPP_INLINE_VISIBILITY
-    void construct(_Tp* __p, _Ts &&... __args)
-    {
-        _VSTD_LFTS::__lfts_user_alloc_construct(
-            __p, *this, _VSTD::forward<_Ts>(__args)...
-          );
-    }
-
-    template <class _T1, class _T2, class ..._Args1, class ..._Args2>
-    _LIBCPP_INLINE_VISIBILITY
-    void construct(pair<_T1, _T2>* __p, piecewise_construct_t,
-                   tuple<_Args1...> __x, tuple<_Args2...> __y)
-    {
-        ::new ((void*)__p) pair<_T1, _T2>(piecewise_construct
-          , __transform_tuple(
-              typename __lfts_uses_alloc_ctor<
-                  _T1, polymorphic_allocator&, _Args1...
-              >::type()
-            , _VSTD::move(__x)
-            , typename __make_tuple_indices<sizeof...(_Args1)>::type{}
-          )
-          , __transform_tuple(
-              typename __lfts_uses_alloc_ctor<
-                  _T2, polymorphic_allocator&, _Args2...
-              >::type()
-            , _VSTD::move(__y)
-            , typename __make_tuple_indices<sizeof...(_Args2)>::type{}
-          )
-        );
-    }
-
-    template <class _T1, class _T2>
-    _LIBCPP_INLINE_VISIBILITY
-    void construct(pair<_T1, _T2>* __p) {
-        construct(__p, piecewise_construct, tuple<>(), tuple<>());
-    }
-
-    template <class _T1, class _T2, class _Up, class _Vp>
-    _LIBCPP_INLINE_VISIBILITY
-    void construct(pair<_T1, _T2> * __p, _Up && __u, _Vp && __v) {
-        construct(__p, piecewise_construct
-          , _VSTD::forward_as_tuple(_VSTD::forward<_Up>(__u))
-          , _VSTD::forward_as_tuple(_VSTD::forward<_Vp>(__v)));
-    }
-
-    template <class _T1, class _T2, class _U1, class _U2>
-    _LIBCPP_INLINE_VISIBILITY
-    void construct(pair<_T1, _T2> * __p, pair<_U1, _U2> const & __pr) {
-        construct(__p, piecewise_construct
-            , _VSTD::forward_as_tuple(__pr.first)
-            , _VSTD::forward_as_tuple(__pr.second));
-    }
-
-    template <class _T1, class _T2, class _U1, class _U2>
-    _LIBCPP_INLINE_VISIBILITY
-    void construct(pair<_T1, _T2> * __p, pair<_U1, _U2> && __pr){
-        construct(__p, piecewise_construct
-            , _VSTD::forward_as_tuple(_VSTD::forward<_U1>(__pr.first))
-            , _VSTD::forward_as_tuple(_VSTD::forward<_U2>(__pr.second)));
-    }
-
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY
-    void destroy(_Tp * __p) _NOEXCEPT
-        { __p->~_Tp(); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    polymorphic_allocator
-    select_on_container_copy_construction() const _NOEXCEPT
-        { return polymorphic_allocator(); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    memory_resource * resource() const _NOEXCEPT
-        { return __res_; }
-
-private:
-    template <class ..._Args, size_t ..._Idx>
-    _LIBCPP_INLINE_VISIBILITY
-    tuple<_Args&&...>
-    __transform_tuple(integral_constant<int, 0>, tuple<_Args...>&& __t,
-                      __tuple_indices<_Idx...>) const
-    {
-        return _VSTD::forward_as_tuple(_VSTD::get<_Idx>(_VSTD::move(__t))...);
-    }
-
-    template <class ..._Args, size_t ..._Idx>
-    _LIBCPP_INLINE_VISIBILITY
-    tuple<allocator_arg_t const&, polymorphic_allocator&, _Args&&...>
-    __transform_tuple(integral_constant<int, 1>, tuple<_Args...> && __t,
-                      __tuple_indices<_Idx...>)
-    {
-        using _Tup = tuple<allocator_arg_t const&, polymorphic_allocator&, _Args&&...>;
-        return _Tup(allocator_arg, *this,
-                    _VSTD::get<_Idx>(_VSTD::move(__t))...);
-    }
-
-    template <class ..._Args, size_t ..._Idx>
-    _LIBCPP_INLINE_VISIBILITY
-    tuple<_Args&&..., polymorphic_allocator&>
-    __transform_tuple(integral_constant<int, 2>, tuple<_Args...> && __t,
-                      __tuple_indices<_Idx...>)
-    {
-        using _Tup = tuple<_Args&&..., polymorphic_allocator&>;
-        return _Tup(_VSTD::get<_Idx>(_VSTD::move(__t))..., *this);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t __max_size() const _NOEXCEPT
-        { return numeric_limits<size_t>::max() / sizeof(value_type); }
-
-    memory_resource * __res_;
-};
-
-// 8.6.4, memory.polymorphic.allocator.eq
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(polymorphic_allocator<_Tp> const & __lhs,
-                polymorphic_allocator<_Up> const & __rhs) _NOEXCEPT
-{
-    return *__lhs.resource() == *__rhs.resource();
-}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(polymorphic_allocator<_Tp> const & __lhs,
-                polymorphic_allocator<_Up> const & __rhs) _NOEXCEPT
-{
-    return !(__lhs == __rhs);
-}
-
-// 8.7, memory.resource.adaptor
-
-// 8.7.1, memory.resource.adaptor.overview
-template <class _CharAlloc>
-class _LIBCPP_TEMPLATE_VIS __resource_adaptor_imp
-  : public memory_resource
-{
-    using _CTraits = allocator_traits<_CharAlloc>;
-    static_assert(is_same<typename _CTraits::value_type, char>::value
-               && is_same<typename _CTraits::pointer, char*>::value
-               && is_same<typename _CTraits::void_pointer, void*>::value, "");
-
-    static const size_t _MaxAlign = _LIBCPP_ALIGNOF(max_align_t);
-
-    using _Alloc = typename _CTraits::template rebind_alloc<
-            typename aligned_storage<_MaxAlign, _MaxAlign>::type
-        >;
-
-    using _ValueType = typename _Alloc::value_type;
-
-    _Alloc __alloc_;
-
-public:
-    typedef _CharAlloc allocator_type;
-
-    __resource_adaptor_imp() = default;
-    __resource_adaptor_imp(__resource_adaptor_imp const &) = default;
-    __resource_adaptor_imp(__resource_adaptor_imp &&) = default;
-
-    // 8.7.2, memory.resource.adaptor.ctor
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __resource_adaptor_imp(allocator_type const & __a)
-      : __alloc_(__a)
-    {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __resource_adaptor_imp(allocator_type && __a)
-      : __alloc_(_VSTD::move(__a))
-    {}
-
-    __resource_adaptor_imp &
-    operator=(__resource_adaptor_imp const &) = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const
-    { return __alloc_; }
-
-// 8.7.3, memory.resource.adaptor.mem
-protected:
-    virtual void * do_allocate(size_t __bytes, size_t)
-    {
-        if (__bytes > __max_size()) {
-            __throw_length_error(
-                "std::experimental::pmr::resource_adaptor<T>::do_allocate(size_t bytes, size_t align)"
-                " 'bytes' exceeds maximum supported size");
-        }
-        size_t __s = __aligned_allocation_size(__bytes, _MaxAlign) / _MaxAlign;
-        return __alloc_.allocate(__s);
-    }
-
-    virtual void do_deallocate(void * __p, size_t __bytes, size_t)
-    {
-        _LIBCPP_ASSERT(__bytes <= __max_size(),
-            "do_deallocate called for size which exceeds the maximum allocation size");
-        size_t __s = __aligned_allocation_size(__bytes, _MaxAlign) / _MaxAlign;
-        __alloc_.deallocate((_ValueType*)__p, __s);
-    }
-
-    virtual bool do_is_equal(memory_resource const & __other) const _NOEXCEPT {
-        __resource_adaptor_imp const * __p
-          = dynamic_cast<__resource_adaptor_imp const *>(&__other);
-        return __p  ? __alloc_ == __p->__alloc_ : false;
-    }
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    size_t __max_size() const _NOEXCEPT {
-        return numeric_limits<size_t>::max() - _MaxAlign;
-    }
-};
-
-template <class _Alloc>
-using resource_adaptor = __resource_adaptor_imp<
-    typename allocator_traits<_Alloc>::template rebind_alloc<char>
-  >;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-_LIBCPP_POP_MACROS
-
-#endif /* _LIBCPP_EXPERIMENTAL_MEMORY_RESOURCE */
diff --git a/lib/libcxx/include/experimental/numeric b/lib/libcxx/include/experimental/numeric
deleted file mode 100644
index 19c65313f0f..00000000000
--- a/lib/libcxx/include/experimental/numeric
+++ /dev/null
@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- numeric ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_NUMERIC
-#define _LIBCPP_EXPERIMENTAL_NUMERIC
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/numeric> has been removed. Use <numeric> instead.")
-#else
-# warning "<experimental/numeric> has been removed. Use <numeric> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_NUMERIC
diff --git a/lib/libcxx/include/experimental/optional b/lib/libcxx/include/experimental/optional
deleted file mode 100644
index 6eb4a2618d2..00000000000
--- a/lib/libcxx/include/experimental/optional
+++ /dev/null
@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- optional ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_OPTIONAL
-#define _LIBCPP_EXPERIMENTAL_OPTIONAL
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/optional> has been removed. Use <optional> instead.")
-#else
-# warning "<experimental/optional> has been removed. Use <optional> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_OPTIONAL
diff --git a/lib/libcxx/include/experimental/propagate_const b/lib/libcxx/include/experimental/propagate_const
deleted file mode 100644
index 188548596b8..00000000000
--- a/lib/libcxx/include/experimental/propagate_const
+++ /dev/null
@@ -1,579 +0,0 @@
-// -*- C++ -*-
-//===------------------------ propagate_const -----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_PROPAGATE_CONST
-#define _LIBCPP_EXPERIMENTAL_PROPAGATE_CONST
-/*
-    propagate_const synopsis
-
-    namespace std { namespace experimental { inline namespace fundamentals_v2 {
-
-    // [propagate_const]
-    template <class T> class propagate_const;
-
-    // [propagate_const.underlying], underlying pointer access
-    constexpr const _Tp& _VSTD_LFTS_V2::get_underlying(const propagate_const<T>& pt) noexcept;
-    constexpr T& _VSTD_LFTS_V2::get_underlying(propagate_const<T>& pt) noexcept;
-
-    // [propagate_const.relational], relational operators
-    template <class T> constexpr bool operator==(const propagate_const<T>& pt, nullptr_t);
-    template <class T> constexpr bool operator==(nullptr_t, const propagate_const<T>& pu);
-    template <class T> constexpr bool operator!=(const propagate_const<T>& pt, nullptr_t);
-    template <class T> constexpr bool operator!=(nullptr_t, const propagate_const<T>& pu);
-    template <class T, class U> constexpr bool operator==(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator!=(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator<(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator>(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator<=(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator>=(const propagate_const<T>& pt, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator==(const propagate_const<T>& pt, const _Up& u);
-    template <class T, class U> constexpr bool operator!=(const propagate_const<T>& pt, const _Up& u);
-    template <class T, class U> constexpr bool operator<(const propagate_const<T>& pt, const _Up& u);
-    template <class T, class U> constexpr bool operator>(const propagate_const<T>& pt, const _Up& u);
-    template <class T, class U> constexpr bool operator<=(const propagate_const<T>& pt, const _Up& u);
-    template <class T, class U> constexpr bool operator>=(const propagate_const<T>& pt, const _Up& u);
-    template <class T, class U> constexpr bool operator==(const _Tp& t, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator!=(const _Tp& t, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator<(const _Tp& t, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator>(const _Tp& t, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator<=(const _Tp& t, const propagate_const<_Up>& pu);
-    template <class T, class U> constexpr bool operator>=(const _Tp& t, const propagate_const<_Up>& pu);
-
-    // [propagate_const.algorithms], specialized algorithms
-    template <class T> constexpr void swap(propagate_const<T>& pt, propagate_const<T>& pu) noexcept(see below);
-
-    template <class T>
-    class propagate_const
-    {
-
-    public:
-      typedef remove_reference_t<decltype(*declval<T&>())> element_type;
-
-      // [propagate_const.ctor], constructors
-      constexpr propagate_const() = default;
-      propagate_const(const propagate_const& p) = delete;
-      constexpr propagate_const(propagate_const&& p) = default;
-      template <class U> EXPLICIT constexpr propagate_const(propagate_const<_Up>&& pu); // see below
-      template <class U> EXPLICIT constexpr propagate_const(U&& u); // see below
-
-      // [propagate_const.assignment], assignment
-      propagate_const& operator=(const propagate_const& p) = delete;
-      constexpr propagate_const& operator=(propagate_const&& p) = default;
-      template <class U> constexpr propagate_const& operator=(propagate_const<_Up>&& pu);
-      template <class U> constexpr propagate_const& operator=(U&& u); // see below
-
-      // [propagate_const.const_observers], const observers
-      explicit constexpr operator bool() const;
-      constexpr const element_type* operator->() const;
-      constexpr operator const element_type*() const; // Not always defined
-      constexpr const element_type& operator*() const;
-      constexpr const element_type* get() const;
-
-      // [propagate_const.non_const_observers], non-const observers
-      constexpr element_type* operator->();
-      constexpr operator element_type*(); // Not always defined
-      constexpr element_type& operator*();
-      constexpr element_type* get();
-
-      // [propagate_const.modifiers], modifiers
-      constexpr void swap(propagate_const& pt) noexcept(see below)
-
-    private:
-      T t_; // exposition only
-    };
-
-  } // namespace fundamentals_v2
-  } // namespace experimental
-
-  // [propagate_const.hash], hash support
-  template <class T> struct hash<experimental::fundamentals_v2::propagate_const<T>>;
-
-  // [propagate_const.comparison_function_objects], comparison function objects
-  template <class T> struct equal_to<experimental::fundamentals_v2::propagate_const<T>>;
-  template <class T> struct not_equal_to<experimental::fundamentals_v2::propagate_const<T>>;
-  template <class T> struct less<experimental::fundamentals_v2::propagate_const<T>>;
-  template <class T> struct greater<experimental::fundamentals_v2::propagate_const<T>>;
-  template <class T> struct less_equal<experimental::fundamentals_v2::propagate_const<T>>;
-  template <class T> struct greater_equal<experimental::fundamentals_v2::propagate_const<T>>;
-
-} // namespace std
-
-*/
-
-#include <experimental/__config>
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#if _LIBCPP_STD_VER > 11
-
-#include <type_traits>
-#include <utility>
-#include <functional>
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_V2
-
-
-template <class _Tp>
-class propagate_const;
-
-template <class _Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-const _Up& get_underlying(const propagate_const<_Up>& __pu) _NOEXCEPT;
-
-template <class _Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-_Up& get_underlying(propagate_const<_Up>& __pu) _NOEXCEPT;
-
-template <class _Tp>
-class propagate_const
-{
-public:
-  typedef remove_reference_t<decltype(*_VSTD::declval<_Tp&>())> element_type;
-
-  static_assert(!is_array<_Tp>::value,
-      "Instantiation of propagate_const with an array type is ill-formed.");
-  static_assert(!is_reference<_Tp>::value,
-      "Instantiation of propagate_const with a reference type is ill-formed.");
-  static_assert(!(is_pointer<_Tp>::value && is_function<typename remove_pointer<_Tp>::type>::value),
-      "Instantiation of propagate_const with a function-pointer type is ill-formed.");
-  static_assert(!(is_pointer<_Tp>::value && is_same<typename remove_cv<typename remove_pointer<_Tp>::type>::type, void>::value),
-      "Instantiation of propagate_const with a pointer to (possibly cv-qualified) void is ill-formed.");
-
-private:
-  template <class _Up>
-  static _LIBCPP_CONSTEXPR element_type* __get_pointer(_Up* __u)
-  {
-    return __u;
-  }
-
-  template <class _Up>
-  static _LIBCPP_CONSTEXPR element_type* __get_pointer(_Up& __u)
-  {
-    return __get_pointer(__u.get());
-  }
-
-  template <class _Up>
-  static _LIBCPP_CONSTEXPR const element_type* __get_pointer(const _Up* __u)
-  {
-    return __u;
-  }
-
-  template <class _Up>
-  static _LIBCPP_CONSTEXPR const element_type* __get_pointer(const _Up& __u)
-  {
-    return __get_pointer(__u.get());
-  }
-
-  template <class _Up>
-  struct __is_propagate_const : false_type
-  {
-  };
-
-  template <class _Up>
-  struct __is_propagate_const<propagate_const<_Up>> : true_type
-  {
-  };
-
-  _Tp __t_;
-
-public:
-
-  template <class _Up> friend _LIBCPP_CONSTEXPR const _Up& ::_VSTD_LFTS_V2::get_underlying(const propagate_const<_Up>& __pu) _NOEXCEPT;
-  template <class _Up> friend _LIBCPP_CONSTEXPR _Up& ::_VSTD_LFTS_V2::get_underlying(propagate_const<_Up>& __pu) _NOEXCEPT;
-
-  _LIBCPP_CONSTEXPR propagate_const() = default;
-
-  propagate_const(const propagate_const&) = delete;
-
-  _LIBCPP_CONSTEXPR propagate_const(propagate_const&&) = default;
-
-  template <class _Up, enable_if_t<!is_convertible<_Up, _Tp>::value &&
-                                 is_constructible<_Tp, _Up&&>::value,bool> = true>
-  explicit _LIBCPP_CONSTEXPR propagate_const(propagate_const<_Up>&& __pu)
-      : __t_(std::move(_VSTD_LFTS_V2::get_underlying(__pu)))
-  {
-  }
-
-  template <class _Up, enable_if_t<is_convertible<_Up&&, _Tp>::value &&
-                                 is_constructible<_Tp, _Up&&>::value,bool> = false>
-  _LIBCPP_CONSTEXPR propagate_const(propagate_const<_Up>&& __pu)
-      : __t_(std::move(_VSTD_LFTS_V2::get_underlying(__pu)))
-  {
-  }
-
-  template <class _Up, enable_if_t<!is_convertible<_Up&&, _Tp>::value &&
-                                 is_constructible<_Tp, _Up&&>::value &&
-                                 !__is_propagate_const<decay_t<_Up>>::value,bool> = true>
-  explicit _LIBCPP_CONSTEXPR propagate_const(_Up&& __u)
-      : __t_(std::forward<_Up>(__u))
-  {
-  }
-
-  template <class _Up, enable_if_t<is_convertible<_Up&&, _Tp>::value &&
-                                 is_constructible<_Tp, _Up&&>::value &&
-                                 !__is_propagate_const<decay_t<_Up>>::value,bool> = false>
-  _LIBCPP_CONSTEXPR propagate_const(_Up&& __u)
-      : __t_(std::forward<_Up>(__u))
-  {
-  }
-
-  propagate_const& operator=(const propagate_const&) = delete;
-
-  _LIBCPP_CONSTEXPR propagate_const& operator=(propagate_const&&) = default;
-
-  template <class _Up>
-  _LIBCPP_CONSTEXPR propagate_const& operator=(propagate_const<_Up>&& __pu)
-  {
-    __t_ = std::move(_VSTD_LFTS_V2::get_underlying(__pu));
-    return *this;
-  }
-
-  template <class _Up, class _Vp = enable_if_t<!__is_propagate_const<decay_t<_Up>>::value>>
-  _LIBCPP_CONSTEXPR propagate_const& operator=(_Up&& __u)
-  {
-    __t_ = std::forward<_Up>(__u);
-    return *this;
-  }
-
-  _LIBCPP_CONSTEXPR const element_type* get() const
-  {
-    return __get_pointer(__t_);
-  }
-
-  _LIBCPP_CONSTEXPR element_type* get()
-  {
-    return __get_pointer(__t_);
-  }
-
-  explicit _LIBCPP_CONSTEXPR operator bool() const
-  {
-    return get() != nullptr;
-  }
-
-  _LIBCPP_CONSTEXPR const element_type* operator->() const
-  {
-    return get();
-  }
-
-  template <class _Tp_ = _Tp, class _Up = enable_if_t<is_convertible<
-                                  const _Tp_, const element_type *>::value>>
-  _LIBCPP_CONSTEXPR operator const element_type *() const {
-    return get();
-  }
-
-  _LIBCPP_CONSTEXPR const element_type& operator*() const
-  {
-    return *get();
-  }
-
-  _LIBCPP_CONSTEXPR element_type* operator->()
-  {
-    return get();
-  }
-
-  template <class _Tp_ = _Tp, class _Up = enable_if_t<
-                                  is_convertible<_Tp_, element_type *>::value>>
-  _LIBCPP_CONSTEXPR operator element_type *() {
-    return get();
-  }
-
-  _LIBCPP_CONSTEXPR element_type& operator*()
-  {
-    return *get();
-  }
-
-  _LIBCPP_CONSTEXPR void swap(propagate_const& __pt) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
-  {
-    using _VSTD::swap;
-    swap(__t_, __pt.__t_);
-  }
-};
-
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator==(const propagate_const<_Tp>& __pt, nullptr_t)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) == nullptr;
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator==(nullptr_t, const propagate_const<_Tp>& __pt)
-{
-  return nullptr == _VSTD_LFTS_V2::get_underlying(__pt);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator!=(const propagate_const<_Tp>& __pt, nullptr_t)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) != nullptr;
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator!=(nullptr_t, const propagate_const<_Tp>& __pt)
-{
-  return nullptr != _VSTD_LFTS_V2::get_underlying(__pt);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator==(const propagate_const<_Tp>& __pt,
-                          const propagate_const<_Up>& __pu)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) == _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator!=(const propagate_const<_Tp>& __pt,
-                          const propagate_const<_Up>& __pu)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) != _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator<(const propagate_const<_Tp>& __pt,
-                         const propagate_const<_Up>& __pu)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) < _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator>(const propagate_const<_Tp>& __pt,
-                         const propagate_const<_Up>& __pu)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) > _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator<=(const propagate_const<_Tp>& __pt,
-                          const propagate_const<_Up>& __pu)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) <= _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator>=(const propagate_const<_Tp>& __pt,
-                          const propagate_const<_Up>& __pu)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) >= _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator==(const propagate_const<_Tp>& __pt, const _Up& __u)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) == __u;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator!=(const propagate_const<_Tp>& __pt, const _Up& __u)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) != __u;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator<(const propagate_const<_Tp>& __pt, const _Up& __u)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) < __u;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator>(const propagate_const<_Tp>& __pt, const _Up& __u)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) > __u;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator<=(const propagate_const<_Tp>& __pt, const _Up& __u)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) <= __u;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator>=(const propagate_const<_Tp>& __pt, const _Up& __u)
-{
-  return _VSTD_LFTS_V2::get_underlying(__pt) >= __u;
-}
-
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator==(const _Tp& __t, const propagate_const<_Up>& __pu)
-{
-  return __t == _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator!=(const _Tp& __t, const propagate_const<_Up>& __pu)
-{
-  return __t != _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator<(const _Tp& __t, const propagate_const<_Up>& __pu)
-{
-  return __t < _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator>(const _Tp& __t, const propagate_const<_Up>& __pu)
-{
-  return __t > _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator<=(const _Tp& __t, const propagate_const<_Up>& __pu)
-{
-  return __t <= _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR bool operator>=(const _Tp& __t, const propagate_const<_Up>& __pu)
-{
-  return __t >= _VSTD_LFTS_V2::get_underlying(__pu);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR void swap(propagate_const<_Tp>& __pc1, propagate_const<_Tp>& __pc2) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
-{
-  __pc1.swap(__pc2);
-}
-
-template <class _Tp>
-_LIBCPP_CONSTEXPR const _Tp& get_underlying(const propagate_const<_Tp>& __pt) _NOEXCEPT
-{
-  return __pt.__t_;
-}
-
-template <class _Tp>
-_LIBCPP_CONSTEXPR _Tp& get_underlying(propagate_const<_Tp>& __pt) _NOEXCEPT
-{
-  return __pt.__t_;
-}
-
-_LIBCPP_END_NAMESPACE_LFTS_V2
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp>
-struct hash<experimental::fundamentals_v2::propagate_const<_Tp>>
-{
-  typedef size_t result_type;
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> argument_type;
-
-  size_t operator()(const experimental::fundamentals_v2::propagate_const<_Tp>& __pc1) const
-  {
-    return std::hash<_Tp>()(_VSTD_LFTS_V2::get_underlying(__pc1));
-  }
-};
-
-template <class _Tp>
-struct equal_to<experimental::fundamentals_v2::propagate_const<_Tp>>
-{
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> first_argument_type;
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> second_argument_type;
-
-  bool operator()(const experimental::fundamentals_v2::propagate_const<_Tp>& __pc1,
-      const experimental::fundamentals_v2::propagate_const<_Tp>& __pc2) const
-  {
-    return std::equal_to<_Tp>()(_VSTD_LFTS_V2::get_underlying(__pc1), _VSTD_LFTS_V2::get_underlying(__pc2));
-  }
-};
-
-template <class _Tp>
-struct not_equal_to<experimental::fundamentals_v2::propagate_const<_Tp>>
-{
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> first_argument_type;
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> second_argument_type;
-
-  bool operator()(const experimental::fundamentals_v2::propagate_const<_Tp>& __pc1,
-      const experimental::fundamentals_v2::propagate_const<_Tp>& __pc2) const
-  {
-    return std::not_equal_to<_Tp>()(_VSTD_LFTS_V2::get_underlying(__pc1), _VSTD_LFTS_V2::get_underlying(__pc2));
-  }
-};
-
-template <class _Tp>
-struct less<experimental::fundamentals_v2::propagate_const<_Tp>>
-{
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> first_argument_type;
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> second_argument_type;
-
-  bool operator()(const experimental::fundamentals_v2::propagate_const<_Tp>& __pc1,
-      const experimental::fundamentals_v2::propagate_const<_Tp>& __pc2) const
-  {
-    return std::less<_Tp>()(_VSTD_LFTS_V2::get_underlying(__pc1), _VSTD_LFTS_V2::get_underlying(__pc2));
-  }
-};
-
-template <class _Tp>
-struct greater<experimental::fundamentals_v2::propagate_const<_Tp>>
-{
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> first_argument_type;
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> second_argument_type;
-
-  bool operator()(const experimental::fundamentals_v2::propagate_const<_Tp>& __pc1,
-      const experimental::fundamentals_v2::propagate_const<_Tp>& __pc2) const
-  {
-    return std::greater<_Tp>()(_VSTD_LFTS_V2::get_underlying(__pc1), _VSTD_LFTS_V2::get_underlying(__pc2));
-  }
-};
-
-template <class _Tp>
-struct less_equal<experimental::fundamentals_v2::propagate_const<_Tp>>
-{
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> first_argument_type;
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> second_argument_type;
-
-  bool operator()(const experimental::fundamentals_v2::propagate_const<_Tp>& __pc1,
-      const experimental::fundamentals_v2::propagate_const<_Tp>& __pc2) const
-  {
-    return std::less_equal<_Tp>()(_VSTD_LFTS_V2::get_underlying(__pc1), _VSTD_LFTS_V2::get_underlying(__pc2));
-  }
-};
-
-template <class _Tp>
-struct greater_equal<experimental::fundamentals_v2::propagate_const<_Tp>>
-{
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> first_argument_type;
-  typedef experimental::fundamentals_v2::propagate_const<_Tp> second_argument_type;
-
-  bool operator()(const experimental::fundamentals_v2::propagate_const<_Tp>& __pc1,
-      const experimental::fundamentals_v2::propagate_const<_Tp>& __pc2) const
-  {
-    return std::greater_equal<_Tp>()(_VSTD_LFTS_V2::get_underlying(__pc1), _VSTD_LFTS_V2::get_underlying(__pc2));
-  }
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP_STD_VER > 11
-#endif // _LIBCPP_EXPERIMENTAL_PROPAGATE_CONST
-
diff --git a/lib/libcxx/include/experimental/ratio b/lib/libcxx/include/experimental/ratio
deleted file mode 100644
index 52c12004dba..00000000000
--- a/lib/libcxx/include/experimental/ratio
+++ /dev/null
@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- ratio ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_RATIO
-#define _LIBCPP_EXPERIMENTAL_RATIO
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/ratio> has been removed. Use <ratio> instead.")
-#else
-# warning "<experimental/ratio> has been removed. Use <ratio> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_RATIO
diff --git a/lib/libcxx/include/experimental/regex b/lib/libcxx/include/experimental/regex
deleted file mode 100644
index d38891c374b..00000000000
--- a/lib/libcxx/include/experimental/regex
+++ /dev/null
@@ -1,62 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- regex ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_REGEX
-#define _LIBCPP_EXPERIMENTAL_REGEX
-/*
-    experimental/regex synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  template <class BidirectionalIterator>
-  using match_results =
-    std::match_results<BidirectionalIterator,
-                       polymorphic_allocator<sub_match<BidirectionalIterator>>>;
-
-  typedef match_results<const char*> cmatch;
-  typedef match_results<const wchar_t*> wcmatch;
-  typedef match_results<string::const_iterator> smatch;
-  typedef match_results<wstring::const_iterator> wsmatch;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <regex>
-#include <experimental/string>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _BiDirIter>
-using match_results =
-    _VSTD::match_results<_BiDirIter,
-        polymorphic_allocator<_VSTD::sub_match<_BiDirIter>>>;
-
-typedef match_results<const char*> cmatch;
-typedef match_results<const wchar_t*> wcmatch;
-typedef match_results<_VSTD_LFTS_PMR::string::const_iterator> smatch;
-typedef match_results<_VSTD_LFTS_PMR::wstring::const_iterator> wsmatch;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_REGEX */
diff --git a/lib/libcxx/include/experimental/set b/lib/libcxx/include/experimental/set
deleted file mode 100644
index 20cf6d4a389..00000000000
--- a/lib/libcxx/include/experimental/set
+++ /dev/null
@@ -1,57 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- list ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_SET
-#define _LIBCPP_EXPERIMENTAL_SET
-/*
-    experimental/set synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  template <class Key, class T, class Compare = less<Key>>
-  using set = std::set<Key, T, Compare,
-                       polymorphic_allocator<pair<const Key,T>>>;
-
-  template <class Key, class T, class Compare = less<Key>>
-  using multiset = std::multiset<Key, T, Compare,
-                                 polymorphic_allocator<pair<const Key,T>>>;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <set>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _Value, class  _Compare = less<_Value>>
-using set = _VSTD::set<_Value, _Compare,
-                        polymorphic_allocator<_Value>>;
-
-template <class _Value, class  _Compare = less<_Value>>
-using multiset = _VSTD::multiset<_Value, _Compare,
-                        polymorphic_allocator<_Value>>;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_SET */
diff --git a/lib/libcxx/include/experimental/simd b/lib/libcxx/include/experimental/simd
deleted file mode 100644
index 6580443f7b0..00000000000
--- a/lib/libcxx/include/experimental/simd
+++ /dev/null
@@ -1,1570 +0,0 @@
-// -*- C++ -*-
-//===------------------------------- simd ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_SIMD
-#define _LIBCPP_EXPERIMENTAL_SIMD
-
-/*
-    experimental/simd synopsis
-
-namespace std::experimental {
-
-inline namespace parallelism_v2 {
-
-namespace simd_abi {
-
-struct scalar {};
-template <int N> struct fixed_size {};
-template <typename T> inline constexpr int max_fixed_size = implementation-defined;
-template <typename T> using compatible = implementation-defined;
-template <typename T> using native = implementation-defined;
-
-} // simd_abi
-
-struct element_aligned_tag {};
-struct vector_aligned_tag {};
-template <size_t> struct overaligned_tag {};
-inline constexpr element_aligned_tag element_aligned{};
-inline constexpr vector_aligned_tag vector_aligned{};
-template <size_t N> inline constexpr overaligned_tag<N> overaligned{};
-
-// traits [simd.traits]
-template <class T> struct is_abi_tag;
-template <class T> inline constexpr bool is_abi_tag_v = is_abi_tag<T>::value;
-
-template <class T> struct is_simd;
-template <class T> inline constexpr bool is_simd_v = is_simd<T>::value;
-
-template <class T> struct is_simd_mask;
-template <class T> inline constexpr bool is_simd_mask_v = is_simd_mask<T>::value;
-
-template <class T> struct is_simd_flag_type;
-template <class T> inline constexpr bool is_simd_flag_type_v = is_simd_flag_type<T>::value;
-
-template <class T, size_t N> struct abi_for_size { using type = see below; };
-template <class T, size_t N> using abi_for_size_t = typename abi_for_size<T, N>::type;
-
-template <class T, class Abi = simd_abi::compatible<T>> struct simd_size;
-template <class T, class Abi = simd_abi::compatible<T>>
-inline constexpr size_t simd_size_v = simd_size<T, Abi>::value;
-
-template <class T, class U = typename T::value_type> struct memory_alignment;
-template <class T, class U = typename T::value_type>
-inline constexpr size_t memory_alignment_v = memory_alignment<T, U>::value;
-
-// class template simd [simd.class]
-template <class T, class Abi = simd_abi::compatible<T>> class simd;
-template <class T> using native_simd = simd<T, simd_abi::native<T>>;
-template <class T, int N> using fixed_size_simd = simd<T, simd_abi::fixed_size<N>>;
-
-// class template simd_mask [simd.mask.class]
-template <class T, class Abi = simd_abi::compatible<T>> class simd_mask;
-template <class T> using native_simd_mask = simd_mask<T, simd_abi::native<T>>;
-template <class T, int N> using fixed_size_simd_mask = simd_mask<T, simd_abi::fixed_size<N>>;
-
-// casts [simd.casts]
-template <class T, class U, class Abi> see below simd_cast(const simd<U, Abi>&);
-template <class T, class U, class Abi> see below static_simd_cast(const simd<U, Abi>&);
-
-template <class T, class Abi>
-fixed_size_simd<T, simd_size_v<T, Abi>> to_fixed_size(const simd<T, Abi>&) noexcept;
-template <class T, class Abi>
-fixed_size_simd_mask<T, simd_size_v<T, Abi>> to_fixed_size(const simd_mask<T, Abi>&) noexcept;
-template <class T, size_t N> native_simd<T> to_native(const fixed_size_simd<T, N>&) noexcept;
-template <class T, size_t N>
-native_simd_mask<T> to_native(const fixed_size_simd_mask<T, N>> &) noexcept;
-template <class T, size_t N> simd<T> to_compatible(const fixed_size_simd<T, N>&) noexcept;
-template <class T, size_t N> simd_mask<T> to_compatible(const fixed_size_simd_mask<T, N>&) noexcept;
-
-template <size_t... Sizes, class T, class Abi>
-tuple<simd<T, abi_for_size_t<Sizes>>...> split(const simd<T, Abi>&);
-template <size_t... Sizes, class T, class Abi>
-tuple<simd_mask<T, abi_for_size_t<Sizes>>...> split(const simd_mask<T, Abi>&);
-template <class V, class Abi>
-array<V, simd_size_v<typename V::value_type, Abi> / V::size()> split(
-const simd<typename V::value_type, Abi>&);
-template <class V, class Abi>
-array<V, simd_size_v<typename V::value_type, Abi> / V::size()> split(
-const simd_mask<typename V::value_type, Abi>&);
-
-template <class T, class... Abis>
-simd<T, abi_for_size_t<T, (simd_size_v<T, Abis> + ...)>> concat(const simd<T, Abis>&...);
-template <class T, class... Abis>
-simd_mask<T, abi_for_size_t<T, (simd_size_v<T, Abis> + ...)>> concat(const simd_mask<T, Abis>&...);
-
-// reductions [simd.mask.reductions]
-template <class T, class Abi> bool all_of(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> bool any_of(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> bool none_of(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> bool some_of(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> int popcount(const simd_mask<T, Abi>&) noexcept;
-template <class T, class Abi> int find_first_set(const simd_mask<T, Abi>&);
-template <class T, class Abi> int find_last_set(const simd_mask<T, Abi>&);
-
-bool all_of(see below) noexcept;
-bool any_of(see below) noexcept;
-bool none_of(see below) noexcept;
-bool some_of(see below) noexcept;
-int popcount(see below) noexcept;
-int find_first_set(see below) noexcept;
-int find_last_set(see below) noexcept;
-
-// masked assignment [simd.whereexpr]
-template <class M, class T> class const_where_expression;
-template <class M, class T> class where_expression;
-
-// masked assignment [simd.mask.where]
-template <class T> struct nodeduce { using type = T; }; // exposition only
-
-template <class T> using nodeduce_t = typename nodeduce<T>::type; // exposition only
-
-template <class T, class Abi>
-where_expression<simd_mask<T, Abi>, simd<T, Abi>>
-where(const typename simd<T, Abi>::mask_type&, simd<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-const_where_expression<simd_mask<T, Abi>, const simd<T, Abi>>
-where(const typename simd<T, Abi>::mask_type&, const simd<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-where_expression<simd_mask<T, Abi>, simd_mask<T, Abi>>
-where(const nodeduce_t<simd_mask<T, Abi>>&, simd_mask<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-const_where_expression<simd_mask<T, Abi>, const simd_mask<T, Abi>>
-where(const nodeduce_t<simd_mask<T, Abi>>&, const simd_mask<T, Abi>&) noexcept;
-
-template <class T> where_expression<bool, T> where(see below k, T& d) noexcept;
-
-template <class T>
-const_where_expression<bool, const T> where(see below k, const T& d) noexcept;
-
-// reductions [simd.reductions]
-template <class T, class Abi, class BinaryOperation = std::plus<>>
-T reduce(const simd<T, Abi>&, BinaryOperation = BinaryOperation());
-
-template <class M, class V, class BinaryOperation>
-typename V::value_type reduce(const const_where_expression<M, V>& x,
-typename V::value_type neutral_element, BinaryOperation binary_op);
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, plus<> binary_op = plus<>());
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, multiplies<> binary_op);
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, bit_and<> binary_op);
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, bit_or<> binary_op);
-
-template <class M, class V>
-typename V::value_type reduce(const const_where_expression<M, V>& x, bit_xor<> binary_op);
-
-template <class T, class Abi> T hmin(const simd<T, Abi>&);
-template <class M, class V> T hmin(const const_where_expression<M, V>&);
-template <class T, class Abi> T hmax(const simd<T, Abi>&);
-template <class M, class V> T hmax(const const_where_expression<M, V>&);
-
-// algorithms [simd.alg]
-template <class T, class Abi> simd<T, Abi> min(const simd<T, Abi>&, const simd<T, Abi>&) noexcept;
-
-template <class T, class Abi> simd<T, Abi> max(const simd<T, Abi>&, const simd<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-std::pair<simd<T, Abi>, simd<T, Abi>> minmax(const simd<T, Abi>&, const simd<T, Abi>&) noexcept;
-
-template <class T, class Abi>
-simd<T, Abi> clamp(const simd<T, Abi>& v, const simd<T, Abi>& lo, const simd<T, Abi>& hi);
-
-// [simd.whereexpr]
-template <class M, class T>
-class const_where_expression {
-  const M& mask; // exposition only
-  T& data; // exposition only
-public:
-  const_where_expression(const const_where_expression&) = delete;
-  const_where_expression& operator=(const const_where_expression&) = delete;
-  remove_const_t<T> operator-() const &&;
-  template <class U, class Flags> void copy_to(U* mem, Flags f) const &&;
-};
-
-template <class M, class T>
-class where_expression : public const_where_expression<M, T> {
-public:
-  where_expression(const where_expression&) = delete;
-  where_expression& operator=(const where_expression&) = delete;
-  template <class U> void operator=(U&& x);
-  template <class U> void operator+=(U&& x);
-  template <class U> void operator-=(U&& x);
-  template <class U> void operator*=(U&& x);
-  template <class U> void operator/=(U&& x);
-  template <class U> void operator%=(U&& x);
-  template <class U> void operator&=(U&& x);
-  template <class U> void operator|=(U&& x);
-  template <class U> void operator^=(U&& x);
-  template <class U> void operator<<=(U&& x);
-  template <class U> void operator>>=(U&& x);
-  void operator++();
-  void operator++(int);
-  void operator--();
-  void operator--(int);
-  template <class U, class Flags> void copy_from(const U* mem, Flags);
-};
-
-// [simd.class]
-template <class T, class Abi> class simd {
-public:
-  using value_type = T;
-  using reference = see below;
-  using mask_type = simd_mask<T, Abi>;
-
-  using abi_type = Abi;
-  static constexpr size_t size() noexcept;
-  simd() = default;
-
-  // implicit type conversion constructor
-  template <class U> simd(const simd<U, simd_abi::fixed_size<size()>>&);
-
-  // implicit broadcast constructor (see below for constraints)
-  template <class U> simd(U&& value);
-
-  // generator constructor (see below for constraints)
-  template <class G> explicit simd(G&& gen);
-
-  // load constructor
-  template <class U, class Flags> simd(const U* mem, Flags f);
-
-  // loads [simd.load]
-  template <class U, class Flags> void copy_from(const U* mem, Flags f);
-
-  // stores [simd.store]
-  template <class U, class Flags> void copy_to(U* mem, Flags f) const;
-
-  // scalar access [simd.subscr]
-  reference operator[](size_t);
-  value_type operator[](size_t) const;
-
-  // unary operators [simd.unary]
-  simd& operator++();
-  simd operator++(int);
-  simd& operator--();
-  simd operator--(int);
-  mask_type operator!() const;
-  simd operator~() const; // see below
-  simd operator+() const;
-  simd operator-() const;
-
-  // binary operators [simd.binary]
-  friend simd operator+ (const simd&, const simd&);
-  friend simd operator- (const simd&, const simd&);
-  friend simd operator* (const simd&, const simd&);
-  friend simd operator/ (const simd&, const simd&);
-  friend simd operator% (const simd&, const simd&);
-  friend simd operator& (const simd&, const simd&);
-  friend simd operator| (const simd&, const simd&);
-  friend simd operator^ (const simd&, const simd&);
-  friend simd operator<<(const simd&, const simd&);
-  friend simd operator>>(const simd&, const simd&);
-  friend simd operator<<(const simd&, int);
-  friend simd operator>>(const simd&, int);
-
-  // compound assignment [simd.cassign]
-  friend simd& operator+= (simd&, const simd&);
-  friend simd& operator-= (simd&, const simd&);
-  friend simd& operator*= (simd&, const simd&);
-  friend simd& operator/= (simd&, const simd&);
-  friend simd& operator%= (simd&, const simd&);
-
-  friend simd& operator&= (simd&, const simd&);
-  friend simd& operator|= (simd&, const simd&);
-  friend simd& operator^= (simd&, const simd&);
-  friend simd& operator<<=(simd&, const simd&);
-  friend simd& operator>>=(simd&, const simd&);
-  friend simd& operator<<=(simd&, int);
-  friend simd& operator>>=(simd&, int);
-
-  // compares [simd.comparison]
-  friend mask_type operator==(const simd&, const simd&);
-  friend mask_type operator!=(const simd&, const simd&);
-  friend mask_type operator>=(const simd&, const simd&);
-  friend mask_type operator<=(const simd&, const simd&);
-  friend mask_type operator> (const simd&, const simd&);
-  friend mask_type operator< (const simd&, const simd&);
-};
-
-// [simd.math]
-template <class Abi> using scharv = simd<signed char, Abi>; // exposition only
-template <class Abi> using shortv = simd<short, Abi>; // exposition only
-template <class Abi> using intv = simd<int, Abi>; // exposition only
-template <class Abi> using longv = simd<long int, Abi>; // exposition only
-template <class Abi> using llongv = simd<long long int, Abi>; // exposition only
-template <class Abi> using floatv = simd<float, Abi>; // exposition only
-template <class Abi> using doublev = simd<double, Abi>; // exposition only
-template <class Abi> using ldoublev = simd<long double, Abi>; // exposition only
-template <class T, class V> using samesize = fixed_size_simd<T, V::size()>; // exposition only
-
-template <class Abi> floatv<Abi> acos(floatv<Abi> x);
-template <class Abi> doublev<Abi> acos(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> acos(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> asin(floatv<Abi> x);
-template <class Abi> doublev<Abi> asin(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> asin(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> atan(floatv<Abi> x);
-template <class Abi> doublev<Abi> atan(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> atan(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> atan2(floatv<Abi> y, floatv<Abi> x);
-template <class Abi> doublev<Abi> atan2(doublev<Abi> y, doublev<Abi> x);
-template <class Abi> ldoublev<Abi> atan2(ldoublev<Abi> y, ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> cos(floatv<Abi> x);
-template <class Abi> doublev<Abi> cos(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> cos(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> sin(floatv<Abi> x);
-template <class Abi> doublev<Abi> sin(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> sin(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> tan(floatv<Abi> x);
-template <class Abi> doublev<Abi> tan(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> tan(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> acosh(floatv<Abi> x);
-template <class Abi> doublev<Abi> acosh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> acosh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> asinh(floatv<Abi> x);
-template <class Abi> doublev<Abi> asinh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> asinh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> atanh(floatv<Abi> x);
-template <class Abi> doublev<Abi> atanh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> atanh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> cosh(floatv<Abi> x);
-template <class Abi> doublev<Abi> cosh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> cosh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> sinh(floatv<Abi> x);
-template <class Abi> doublev<Abi> sinh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> sinh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> tanh(floatv<Abi> x);
-template <class Abi> doublev<Abi> tanh(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> tanh(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> exp(floatv<Abi> x);
-template <class Abi> doublev<Abi> exp(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> exp(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> exp2(floatv<Abi> x);
-template <class Abi> doublev<Abi> exp2(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> exp2(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> expm1(floatv<Abi> x);
-template <class Abi> doublev<Abi> expm1(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> expm1(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> frexp(floatv<Abi> value, samesize<int, floatv<Abi>>* exp);
-template <class Abi> doublev<Abi> frexp(doublev<Abi> value, samesize<int, doublev<Abi>>* exp);
-template <class Abi> ldoublev<Abi> frexp(ldoublev<Abi> value, samesize<int, ldoublev<Abi>>* exp);
-
-template <class Abi> samesize<int, floatv<Abi>> ilogb(floatv<Abi> x);
-template <class Abi> samesize<int, doublev<Abi>> ilogb(doublev<Abi> x);
-template <class Abi> samesize<int, ldoublev<Abi>> ilogb(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> ldexp(floatv<Abi> x, samesize<int, floatv<Abi>> exp);
-template <class Abi> doublev<Abi> ldexp(doublev<Abi> x, samesize<int, doublev<Abi>> exp);
-template <class Abi> ldoublev<Abi> ldexp(ldoublev<Abi> x, samesize<int, ldoublev<Abi>> exp);
-
-template <class Abi> floatv<Abi> log(floatv<Abi> x);
-template <class Abi> doublev<Abi> log(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> log(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> log10(floatv<Abi> x);
-template <class Abi> doublev<Abi> log10(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> log10(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> log1p(floatv<Abi> x);
-template <class Abi> doublev<Abi> log1p(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> log1p(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> log2(floatv<Abi> x);
-template <class Abi> doublev<Abi> log2(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> log2(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> logb(floatv<Abi> x);
-template <class Abi> doublev<Abi> logb(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> logb(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> modf(floatv<Abi> value, floatv<Abi>* iptr);
-template <class Abi> doublev<Abi> modf(doublev<Abi> value, doublev<Abi>* iptr);
-template <class Abi> ldoublev<Abi> modf(ldoublev<Abi> value, ldoublev<Abi>* iptr);
-
-template <class Abi> floatv<Abi> scalbn(floatv<Abi> x, samesize<int, floatv<Abi>> n);
-template <class Abi> doublev<Abi> scalbn(doublev<Abi> x, samesize<int, doublev<Abi>> n);
-template <class Abi> ldoublev<Abi> scalbn(ldoublev<Abi> x, samesize<int, ldoublev<Abi>> n);
-template <class Abi> floatv<Abi> scalbln(floatv<Abi> x, samesize<long int, floatv<Abi>> n);
-template <class Abi> doublev<Abi> scalbln(doublev<Abi> x, samesize<long int, doublev<Abi>> n);
-template <class Abi> ldoublev<Abi> scalbln(ldoublev<Abi> x, samesize<long int, ldoublev<Abi>> n);
-
-template <class Abi> floatv<Abi> cbrt(floatv<Abi> x);
-template <class Abi> doublev<Abi> cbrt(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> cbrt(ldoublev<Abi> x);
-
-template <class Abi> scharv<Abi> abs(scharv<Abi> j);
-template <class Abi> shortv<Abi> abs(shortv<Abi> j);
-template <class Abi> intv<Abi> abs(intv<Abi> j);
-template <class Abi> longv<Abi> abs(longv<Abi> j);
-template <class Abi> llongv<Abi> abs(llongv<Abi> j);
-template <class Abi> floatv<Abi> abs(floatv<Abi> j);
-template <class Abi> doublev<Abi> abs(doublev<Abi> j);
-template <class Abi> ldoublev<Abi> abs(ldoublev<Abi> j);
-
-template <class Abi> floatv<Abi> hypot(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> hypot(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> hypot(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> floatv<Abi> hypot(floatv<Abi> x, floatv<Abi> y, floatv<Abi> z);
-template <class Abi> doublev<Abi> hypot(doublev<Abi> x, doublev<Abi> y, doublev<Abi> z);
-template <class Abi> ldoublev<Abi> hypot(ldoublev<Abi> x, ldoublev<Abi> y, ldoublev<Abi> z);
-
-template <class Abi> floatv<Abi> pow(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> pow(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> pow(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> sqrt(floatv<Abi> x);
-template <class Abi> doublev<Abi> sqrt(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> sqrt(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> erf(floatv<Abi> x);
-template <class Abi> doublev<Abi> erf(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> erf(ldoublev<Abi> x);
-template <class Abi> floatv<Abi> erfc(floatv<Abi> x);
-template <class Abi> doublev<Abi> erfc(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> erfc(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> lgamma(floatv<Abi> x);
-template <class Abi> doublev<Abi> lgamma(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> lgamma(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> tgamma(floatv<Abi> x);
-template <class Abi> doublev<Abi> tgamma(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> tgamma(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> ceil(floatv<Abi> x);
-template <class Abi> doublev<Abi> ceil(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> ceil(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> floor(floatv<Abi> x);
-template <class Abi> doublev<Abi> floor(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> floor(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> nearbyint(floatv<Abi> x);
-template <class Abi> doublev<Abi> nearbyint(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> nearbyint(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> rint(floatv<Abi> x);
-template <class Abi> doublev<Abi> rint(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> rint(ldoublev<Abi> x);
-
-template <class Abi> samesize<long int, floatv<Abi>> lrint(floatv<Abi> x);
-template <class Abi> samesize<long int, doublev<Abi>> lrint(doublev<Abi> x);
-template <class Abi> samesize<long int, ldoublev<Abi>> lrint(ldoublev<Abi> x);
-template <class Abi> samesize<long long int, floatv<Abi>> llrint(floatv<Abi> x);
-template <class Abi> samesize<long long int, doublev<Abi>> llrint(doublev<Abi> x);
-template <class Abi> samesize<long long int, ldoublev<Abi>> llrint(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> round(floatv<Abi> x);
-template <class Abi> doublev<Abi> round(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> round(ldoublev<Abi> x);
-template <class Abi> samesize<long int, floatv<Abi>> lround(floatv<Abi> x);
-template <class Abi> samesize<long int, doublev<Abi>> lround(doublev<Abi> x);
-template <class Abi> samesize<long int, ldoublev<Abi>> lround(ldoublev<Abi> x);
-template <class Abi> samesize<long long int, floatv<Abi>> llround(floatv<Abi> x);
-template <class Abi> samesize<long long int, doublev<Abi>> llround(doublev<Abi> x);
-template <class Abi> samesize<long long int, ldoublev<Abi>> llround(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> trunc(floatv<Abi> x);
-template <class Abi> doublev<Abi> trunc(doublev<Abi> x);
-template <class Abi> ldoublev<Abi> trunc(ldoublev<Abi> x);
-
-template <class Abi> floatv<Abi> fmod(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> fmod(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> fmod(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> remainder(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> remainder(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> remainder(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> remquo(floatv<Abi> x, floatv<Abi> y, samesize<int, floatv<Abi>>* quo);
-template <class Abi> doublev<Abi> remquo(doublev<Abi> x, doublev<Abi> y, samesize<int, doublev<Abi>>* quo);
-template <class Abi> ldoublev<Abi> remquo(ldoublev<Abi> x, ldoublev<Abi> y, samesize<int, ldoublev<Abi>>* quo);
-
-template <class Abi> floatv<Abi> copysign(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> copysign(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> copysign(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> doublev<Abi> nan(const char* tagp);
-template <class Abi> floatv<Abi> nanf(const char* tagp);
-template <class Abi> ldoublev<Abi> nanl(const char* tagp);
-
-template <class Abi> floatv<Abi> nextafter(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> nextafter(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> nextafter(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> nexttoward(floatv<Abi> x, ldoublev<Abi> y);
-template <class Abi> doublev<Abi> nexttoward(doublev<Abi> x, ldoublev<Abi> y);
-template <class Abi> ldoublev<Abi> nexttoward(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> fdim(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> fdim(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> fdim(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> fmax(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> fmax(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> fmax(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> fmin(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> doublev<Abi> fmin(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> ldoublev<Abi> fmin(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> floatv<Abi> fma(floatv<Abi> x, floatv<Abi> y, floatv<Abi> z);
-template <class Abi> doublev<Abi> fma(doublev<Abi> x, doublev<Abi> y, doublev<Abi> z);
-template <class Abi> ldoublev<Abi> fma(ldoublev<Abi> x, ldoublev<Abi> y, ldoublev<Abi> z);
-
-template <class Abi> samesize<int, floatv<Abi>> fpclassify(floatv<Abi> x);
-template <class Abi> samesize<int, doublev<Abi>> fpclassify(doublev<Abi> x);
-template <class Abi> samesize<int, ldoublev<Abi>> fpclassify(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isfinite(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> isfinite(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> isfinite(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isinf(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> isinf(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> isinf(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isnan(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> isnan(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> isnan(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isnormal(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> isnormal(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> isnormal(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> signbit(floatv<Abi> x);
-template <class Abi> simd_mask<double, Abi> signbit(doublev<Abi> x);
-template <class Abi> simd_mask<long double, Abi> signbit(ldoublev<Abi> x);
-
-template <class Abi> simd_mask<float, Abi> isgreater(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> isgreater(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> isgreater(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> isgreaterequal(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> isgreaterequal(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> isgreaterequal(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> isless(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> isless(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> isless(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> islessequal(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> islessequal(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> islessequal(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> islessgreater(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> islessgreater(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> islessgreater(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class Abi> simd_mask<float, Abi> isunordered(floatv<Abi> x, floatv<Abi> y);
-template <class Abi> simd_mask<double, Abi> isunordered(doublev<Abi> x, doublev<Abi> y);
-template <class Abi> simd_mask<long double, Abi> isunordered(ldoublev<Abi> x, ldoublev<Abi> y);
-
-template <class V> struct simd_div_t { V quot, rem; };
-template <class Abi> simd_div_t<scharv<Abi>> div(scharv<Abi> numer, scharv<Abi> denom);
-template <class Abi> simd_div_t<shortv<Abi>> div(shortv<Abi> numer, shortv<Abi> denom);
-template <class Abi> simd_div_t<intv<Abi>> div(intv<Abi> numer, intv<Abi> denom);
-template <class Abi> simd_div_t<longv<Abi>> div(longv<Abi> numer, longv<Abi> denom);
-template <class Abi> simd_div_t<llongv<Abi>> div(llongv<Abi> numer, llongv<Abi> denom);
-
-// [simd.mask.class]
-template <class T, class Abi>
-class simd_mask {
-public:
-  using value_type = bool;
-  using reference = see below;
-  using simd_type = simd<T, Abi>;
-  using abi_type = Abi;
-  static constexpr size_t size() noexcept;
-  simd_mask() = default;
-
-  // broadcast constructor
-  explicit simd_mask(value_type) noexcept;
-
-  // implicit type conversion constructor
-  template <class U> simd_mask(const simd_mask<U, simd_abi::fixed_size<size()>>&) noexcept;
-
-  // load constructor
-  template <class Flags> simd_mask(const value_type* mem, Flags);
-
-  // loads [simd.mask.copy]
-  template <class Flags> void copy_from(const value_type* mem, Flags);
-  template <class Flags> void copy_to(value_type* mem, Flags) const;
-
-  // scalar access [simd.mask.subscr]
-  reference operator[](size_t);
-  value_type operator[](size_t) const;
-
-  // unary operators [simd.mask.unary]
-  simd_mask operator!() const noexcept;
-
-  // simd_mask binary operators [simd.mask.binary]
-  friend simd_mask operator&&(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator||(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator& (const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator| (const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator^ (const simd_mask&, const simd_mask&) noexcept;
-
-  // simd_mask compound assignment [simd.mask.cassign]
-  friend simd_mask& operator&=(simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask& operator|=(simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask& operator^=(simd_mask&, const simd_mask&) noexcept;
-
-  // simd_mask compares [simd.mask.comparison]
-  friend simd_mask operator==(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator!=(const simd_mask&, const simd_mask&) noexcept;
-};
-
-} // parallelism_v2
-} // std::experimental
-
-*/
-
-#include <experimental/__config>
-#include <algorithm>
-#include <array>
-#include <cstddef>
-#include <functional>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD
-
-#if _LIBCPP_STD_VER >= 17
-
-enum class _StorageKind {
-  _Scalar,
-  _Array,
-  _VecExt,
-};
-
-template <_StorageKind __kind, int _Np>
-struct __simd_abi {};
-
-template <class _Tp, class _Abi>
-class __simd_storage {};
-
-template <class _Tp, int __num_element>
-class __simd_storage<_Tp, __simd_abi<_StorageKind::_Array, __num_element>> {
-  std::array<_Tp, __num_element> __storage_;
-
-  template <class, class>
-  friend struct simd;
-
-  template <class, class>
-  friend struct simd_mask;
-
-public:
-  _Tp __get(size_t __index) const noexcept { return __storage_[__index]; };
-  void __set(size_t __index, _Tp __val) noexcept {
-    __storage_[__index] = __val;
-  }
-};
-
-template <class _Tp>
-class __simd_storage<_Tp, __simd_abi<_StorageKind::_Scalar, 1>> {
-  _Tp __storage_;
-
-  template <class, class>
-  friend struct simd;
-
-  template <class, class>
-  friend struct simd_mask;
-
-public:
-  _Tp __get(size_t __index) const noexcept { return (&__storage_)[__index]; };
-  void __set(size_t __index, _Tp __val) noexcept {
-    (&__storage_)[__index] = __val;
-  }
-};
-
-#ifndef _LIBCPP_HAS_NO_VECTOR_EXTENSION
-
-constexpr size_t __floor_pow_of_2(size_t __val) {
-  return ((__val - 1) & __val) == 0 ? __val
-                                    : __floor_pow_of_2((__val - 1) & __val);
-}
-
-constexpr size_t __ceil_pow_of_2(size_t __val) {
-  return __val == 1 ? 1 : __floor_pow_of_2(__val - 1) << 1;
-}
-
-template <class _Tp, size_t __bytes>
-struct __vec_ext_traits {
-#if !defined(_LIBCPP_COMPILER_CLANG)
-  typedef _Tp type __attribute__((vector_size(__ceil_pow_of_2(__bytes))));
-#endif
-};
-
-#if defined(_LIBCPP_COMPILER_CLANG)
-#define _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, _NUM_ELEMENT)                        \
-  template <>                                                                  \
-  struct __vec_ext_traits<_TYPE, sizeof(_TYPE) * _NUM_ELEMENT> {               \
-    using type =                                                               \
-        _TYPE __attribute__((vector_size(sizeof(_TYPE) * _NUM_ELEMENT)));      \
-  }
-
-#define _LIBCPP_SPECIALIZE_VEC_EXT_32(_TYPE)                                   \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 1);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 2);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 3);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 4);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 5);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 6);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 7);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 8);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 9);                                        \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 10);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 11);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 12);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 13);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 14);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 15);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 16);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 17);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 18);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 19);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 20);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 21);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 22);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 23);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 24);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 25);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 26);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 27);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 28);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 29);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 30);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 31);                                       \
-  _LIBCPP_SPECIALIZE_VEC_EXT(_TYPE, 32);
-
-_LIBCPP_SPECIALIZE_VEC_EXT_32(char);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(char16_t);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(char32_t);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(wchar_t);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed char);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed short);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed int);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed long);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(signed long long);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned char);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned short);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned int);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned long);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(unsigned long long);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(float);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(double);
-_LIBCPP_SPECIALIZE_VEC_EXT_32(long double);
-
-#undef _LIBCPP_SPECIALIZE_VEC_EXT_32
-#undef _LIBCPP_SPECIALIZE_VEC_EXT
-#endif
-
-template <class _Tp, int __num_element>
-class __simd_storage<_Tp, __simd_abi<_StorageKind::_VecExt, __num_element>> {
-  using _StorageType =
-      typename __vec_ext_traits<_Tp, sizeof(_Tp) * __num_element>::type;
-
-  _StorageType __storage_;
-
-  template <class, class>
-  friend struct simd;
-
-  template <class, class>
-  friend struct simd_mask;
-
-public:
-  _Tp __get(size_t __index) const noexcept { return __storage_[__index]; };
-  void __set(size_t __index, _Tp __val) noexcept {
-    __storage_[__index] = __val;
-  }
-};
-
-#endif // _LIBCPP_HAS_NO_VECTOR_EXTENSION
-
-template <class _Vp, class _Tp, class _Abi>
-class __simd_reference {
-  static_assert(std::is_same<_Vp, _Tp>::value, "");
-
-  template <class, class>
-  friend struct simd;
-
-  template <class, class>
-  friend struct simd_mask;
-
-  __simd_storage<_Tp, _Abi>* __ptr_;
-  size_t __index_;
-
-  __simd_reference(__simd_storage<_Tp, _Abi>* __ptr, size_t __index)
-      : __ptr_(__ptr), __index_(__index) {}
-
-  __simd_reference(const __simd_reference&) = default;
-
-public:
-  __simd_reference() = delete;
-  __simd_reference& operator=(const __simd_reference&) = delete;
-
-  operator _Vp() const { return __ptr_->__get(__index_); }
-
-  __simd_reference operator=(_Vp __value) && {
-    __ptr_->__set(__index_, __value);
-    return *this;
-  }
-
-  __simd_reference operator++() && {
-    return std::move(*this) = __ptr_->__get(__index_) + 1;
-  }
-
-  _Vp operator++(int) && {
-    auto __val = __ptr_->__get(__index_);
-    __ptr_->__set(__index_, __val + 1);
-    return __val;
-  }
-
-  __simd_reference operator--() && {
-    return std::move(*this) = __ptr_->__get(__index_) - 1;
-  }
-
-  _Vp operator--(int) && {
-    auto __val = __ptr_->__get(__index_);
-    __ptr_->__set(__index_, __val - 1);
-    return __val;
-  }
-
-  __simd_reference operator+=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) + __value;
-  }
-
-  __simd_reference operator-=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) - __value;
-  }
-
-  __simd_reference operator*=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) * __value;
-  }
-
-  __simd_reference operator/=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) / __value;
-  }
-
-  __simd_reference operator%=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) % __value;
-  }
-
-  __simd_reference operator>>=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) >> __value;
-  }
-
-  __simd_reference operator<<=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) << __value;
-  }
-
-  __simd_reference operator&=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) & __value;
-  }
-
-  __simd_reference operator|=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) | __value;
-  }
-
-  __simd_reference operator^=(_Vp __value) && {
-    return std::move(*this) = __ptr_->__get(__index_) ^ __value;
-  }
-};
-
-template <class _To, class _From>
-constexpr decltype(_To{std::declval<_From>()}, true)
-__is_non_narrowing_convertible_impl(_From) {
-  return true;
-}
-
-template <class _To>
-constexpr bool __is_non_narrowing_convertible_impl(...) {
-  return false;
-}
-
-template <class _From, class _To>
-constexpr typename std::enable_if<std::is_arithmetic<_To>::value &&
-                                      std::is_arithmetic<_From>::value,
-                                  bool>::type
-__is_non_narrowing_arithmetic_convertible() {
-  return __is_non_narrowing_convertible_impl<_To>(_From{});
-}
-
-template <class _From, class _To>
-constexpr typename std::enable_if<!(std::is_arithmetic<_To>::value &&
-                                    std::is_arithmetic<_From>::value),
-                                  bool>::type
-__is_non_narrowing_arithmetic_convertible() {
-  return false;
-}
-
-template <class _Tp>
-constexpr _Tp __variadic_sum() {
-  return _Tp{};
-}
-
-template <class _Tp, class _Up, class... _Args>
-constexpr _Tp __variadic_sum(_Up __first, _Args... __rest) {
-  return static_cast<_Tp>(__first) + __variadic_sum<_Tp>(__rest...);
-}
-
-template <class _Tp>
-struct __nodeduce {
-  using type = _Tp;
-};
-
-template <class _Tp>
-constexpr bool __vectorizable() {
-  return std::is_arithmetic<_Tp>::value && !std::is_const<_Tp>::value &&
-         !std::is_volatile<_Tp>::value && !std::is_same<_Tp, bool>::value;
-}
-
-_LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD
-_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD_ABI
-
-using scalar = __simd_abi<_StorageKind::_Scalar, 1>;
-
-template <int _Np>
-using fixed_size = __simd_abi<_StorageKind::_Array, _Np>;
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr size_t max_fixed_size = 32;
-
-template <class _Tp>
-using compatible = fixed_size<16 / sizeof(_Tp)>;
-
-#ifndef _LIBCPP_HAS_NO_VECTOR_EXTENSION
-template <class _Tp>
-using native = __simd_abi<_StorageKind::_VecExt,
-                          _LIBCPP_NATIVE_SIMD_WIDTH_IN_BYTES / sizeof(_Tp)>;
-#else
-template <class _Tp>
-using native =
-    fixed_size<_Tp, _LIBCPP_NATIVE_SIMD_WIDTH_IN_BYTES / sizeof(_Tp)>;
-#endif // _LIBCPP_HAS_NO_VECTOR_EXTENSION
-
-_LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD_ABI
-_LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_SIMD
-
-template <class _Tp, class _Abi = simd_abi::compatible<_Tp>>
-class simd;
-template <class _Tp, class _Abi = simd_abi::compatible<_Tp>>
-class simd_mask;
-
-struct element_aligned_tag {};
-struct vector_aligned_tag {};
-template <size_t>
-struct overaligned_tag {};
-_LIBCPP_INLINE_VAR constexpr element_aligned_tag element_aligned{};
-_LIBCPP_INLINE_VAR constexpr vector_aligned_tag vector_aligned{};
-template <size_t _Np>
-_LIBCPP_INLINE_VAR constexpr overaligned_tag<_Np> overaligned{};
-
-// traits [simd.traits]
-template <class _Tp>
-struct is_abi_tag : std::integral_constant<bool, false> {};
-
-template <_StorageKind __kind, int _Np>
-struct is_abi_tag<__simd_abi<__kind, _Np>>
-    : std::integral_constant<bool, true> {};
-
-template <class _Tp>
-struct is_simd : std::integral_constant<bool, false> {};
-
-template <class _Tp, class _Abi>
-struct is_simd<simd<_Tp, _Abi>> : std::integral_constant<bool, true> {};
-
-template <class _Tp>
-struct is_simd_mask : std::integral_constant<bool, false> {};
-
-template <class _Tp, class _Abi>
-struct is_simd_mask<simd_mask<_Tp, _Abi>> : std::integral_constant<bool, true> {
-};
-
-template <class _Tp>
-struct is_simd_flag_type : std::integral_constant<bool, false> {};
-
-template <>
-struct is_simd_flag_type<element_aligned_tag>
-    : std::integral_constant<bool, true> {};
-
-template <>
-struct is_simd_flag_type<vector_aligned_tag>
-    : std::integral_constant<bool, true> {};
-
-template <size_t _Align>
-struct is_simd_flag_type<overaligned_tag<_Align>>
-    : std::integral_constant<bool, true> {};
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr bool is_abi_tag_v = is_abi_tag<_Tp>::value;
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr bool is_simd_v = is_simd<_Tp>::value;
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr bool is_simd_mask_v = is_simd_mask<_Tp>::value;
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr bool is_simd_flag_type_v =
-    is_simd_flag_type<_Tp>::value;
-template <class _Tp, size_t _Np>
-struct abi_for_size {
-  using type = simd_abi::fixed_size<_Np>;
-};
-template <class _Tp, size_t _Np>
-using abi_for_size_t = typename abi_for_size<_Tp, _Np>::type;
-
-template <class _Tp, class _Abi = simd_abi::compatible<_Tp>>
-struct simd_size;
-
-template <class _Tp, _StorageKind __kind, int _Np>
-struct simd_size<_Tp, __simd_abi<__kind, _Np>>
-    : std::integral_constant<size_t, _Np> {
-  static_assert(
-      std::is_arithmetic<_Tp>::value &&
-          !std::is_same<typename std::remove_const<_Tp>::type, bool>::value,
-      "Element type should be vectorizable");
-};
-
-// TODO: implement it.
-template <class _Tp, class _Up = typename _Tp::value_type>
-struct memory_alignment;
-
-template <class _Tp, class _Abi = simd_abi::compatible<_Tp>>
-_LIBCPP_INLINE_VAR constexpr size_t simd_size_v = simd_size<_Tp, _Abi>::value;
-
-template <class _Tp, class _Up = typename _Tp::value_type>
-_LIBCPP_INLINE_VAR constexpr size_t memory_alignment_v =
-    memory_alignment<_Tp, _Up>::value;
-
-// class template simd [simd.class]
-template <class _Tp>
-using native_simd = simd<_Tp, simd_abi::native<_Tp>>;
-template <class _Tp, int _Np>
-using fixed_size_simd = simd<_Tp, simd_abi::fixed_size<_Np>>;
-
-// class template simd_mask [simd.mask.class]
-template <class _Tp>
-using native_simd_mask = simd_mask<_Tp, simd_abi::native<_Tp>>;
-
-template <class _Tp, int _Np>
-using fixed_size_simd_mask = simd_mask<_Tp, simd_abi::fixed_size<_Np>>;
-
-// casts [simd.casts]
-template <class _Tp>
-struct __static_simd_cast_traits {
-  template <class _Up, class _Abi>
-  static simd<_Tp, _Abi> __apply(const simd<_Up, _Abi>& __v);
-};
-
-template <class _Tp, class _NewAbi>
-struct __static_simd_cast_traits<simd<_Tp, _NewAbi>> {
-  template <class _Up, class _Abi>
-  static typename std::enable_if<simd<_Up, _Abi>::size() ==
-                                     simd<_Tp, _NewAbi>::size(),
-                                 simd<_Tp, _NewAbi>>::type
-  __apply(const simd<_Up, _Abi>& __v);
-};
-
-template <class _Tp>
-struct __simd_cast_traits {
-  template <class _Up, class _Abi>
-  static typename std::enable_if<
-      __is_non_narrowing_arithmetic_convertible<_Up, _Tp>(),
-      simd<_Tp, _Abi>>::type
-  __apply(const simd<_Up, _Abi>& __v);
-};
-
-template <class _Tp, class _NewAbi>
-struct __simd_cast_traits<simd<_Tp, _NewAbi>> {
-  template <class _Up, class _Abi>
-  static typename std::enable_if<
-      __is_non_narrowing_arithmetic_convertible<_Up, _Tp>() &&
-          simd<_Up, _Abi>::size() == simd<_Tp, _NewAbi>::size(),
-      simd<_Tp, _NewAbi>>::type
-  __apply(const simd<_Up, _Abi>& __v);
-};
-
-template <class _Tp, class _Up, class _Abi>
-auto simd_cast(const simd<_Up, _Abi>& __v)
-    -> decltype(__simd_cast_traits<_Tp>::__apply(__v)) {
-  return __simd_cast_traits<_Tp>::__apply(__v);
-}
-
-template <class _Tp, class _Up, class _Abi>
-auto static_simd_cast(const simd<_Up, _Abi>& __v)
-    -> decltype(__static_simd_cast_traits<_Tp>::__apply(__v)) {
-  return __static_simd_cast_traits<_Tp>::__apply(__v);
-}
-
-template <class _Tp, class _Abi>
-fixed_size_simd<_Tp, simd_size<_Tp, _Abi>::value>
-to_fixed_size(const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-fixed_size_simd_mask<_Tp, simd_size<_Tp, _Abi>::value>
-to_fixed_size(const simd_mask<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, size_t _Np>
-native_simd<_Tp> to_native(const fixed_size_simd<_Tp, _Np>&) noexcept;
-
-template <class _Tp, size_t _Np>
-native_simd_mask<_Tp> to_native(const fixed_size_simd_mask<_Tp, _Np>&) noexcept;
-
-template <class _Tp, size_t _Np>
-simd<_Tp> to_compatible(const fixed_size_simd<_Tp, _Np>&) noexcept;
-
-template <class _Tp, size_t _Np>
-simd_mask<_Tp> to_compatible(const fixed_size_simd_mask<_Tp, _Np>&) noexcept;
-
-template <size_t... __sizes, class _Tp, class _Abi>
-tuple<simd<_Tp, abi_for_size_t<_Tp, __sizes>>...> split(const simd<_Tp, _Abi>&);
-
-template <size_t... __sizes, class _Tp, class _Abi>
-tuple<simd_mask<_Tp, abi_for_size_t<_Tp, __sizes>>...>
-split(const simd_mask<_Tp, _Abi>&);
-
-template <class _SimdType, class _Abi>
-array<_SimdType, simd_size<typename _SimdType::value_type, _Abi>::value /
-                     _SimdType::size()>
-split(const simd<typename _SimdType::value_type, _Abi>&);
-
-template <class _SimdType, class _Abi>
-array<_SimdType, simd_size<typename _SimdType::value_type, _Abi>::value /
-                     _SimdType::size()>
-split(const simd_mask<typename _SimdType::value_type, _Abi>&);
-
-template <class _Tp, class... _Abis>
-simd<_Tp, abi_for_size_t<_Tp, __variadic_sum(simd_size<_Tp, _Abis>::value...)>>
-concat(const simd<_Tp, _Abis>&...);
-
-template <class _Tp, class... _Abis>
-simd_mask<_Tp,
-          abi_for_size_t<_Tp, __variadic_sum(simd_size<_Tp, _Abis>::value...)>>
-concat(const simd_mask<_Tp, _Abis>&...);
-
-// reductions [simd.mask.reductions]
-template <class _Tp, class _Abi>
-bool all_of(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-bool any_of(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-bool none_of(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-bool some_of(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-int popcount(const simd_mask<_Tp, _Abi>&) noexcept;
-template <class _Tp, class _Abi>
-int find_first_set(const simd_mask<_Tp, _Abi>&);
-template <class _Tp, class _Abi>
-int find_last_set(const simd_mask<_Tp, _Abi>&);
-bool all_of(bool) noexcept;
-bool any_of(bool) noexcept;
-bool none_of(bool) noexcept;
-bool some_of(bool) noexcept;
-int popcount(bool) noexcept;
-int find_first_set(bool) noexcept;
-int find_last_set(bool) noexcept;
-
-// masked assignment [simd.whereexpr]
-template <class _MaskType, class _Tp>
-class const_where_expression;
-template <class _MaskType, class _Tp>
-class where_expression;
-
-// masked assignment [simd.mask.where]
-template <class _Tp, class _Abi>
-where_expression<simd_mask<_Tp, _Abi>, simd<_Tp, _Abi>>
-where(const typename simd<_Tp, _Abi>::mask_type&, simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-const_where_expression<simd_mask<_Tp, _Abi>, const simd<_Tp, _Abi>>
-where(const typename simd<_Tp, _Abi>::mask_type&,
-      const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-where_expression<simd_mask<_Tp, _Abi>, simd_mask<_Tp, _Abi>>
-where(const typename __nodeduce<simd_mask<_Tp, _Abi>>::type&,
-      simd_mask<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-const_where_expression<simd_mask<_Tp, _Abi>, const simd_mask<_Tp, _Abi>>
-where(const typename __nodeduce<simd_mask<_Tp, _Abi>>::type&,
-      const simd_mask<_Tp, _Abi>&) noexcept;
-
-template <class _Tp>
-where_expression<bool, _Tp> where(bool, _Tp&) noexcept;
-
-template <class _Tp>
-const_where_expression<bool, const _Tp> where(bool, const _Tp&) noexcept;
-
-// reductions [simd.reductions]
-template <class _Tp, class _Abi, class _BinaryOp = std::plus<_Tp>>
-_Tp reduce(const simd<_Tp, _Abi>&, _BinaryOp = _BinaryOp());
-
-template <class _MaskType, class _SimdType, class _BinaryOp>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       typename _SimdType::value_type neutral_element, _BinaryOp binary_op);
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       plus<typename _SimdType::value_type> binary_op = {});
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       multiplies<typename _SimdType::value_type> binary_op);
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       bit_and<typename _SimdType::value_type> binary_op);
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       bit_or<typename _SimdType::value_type> binary_op);
-
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-reduce(const const_where_expression<_MaskType, _SimdType>&,
-       bit_xor<typename _SimdType::value_type> binary_op);
-
-template <class _Tp, class _Abi>
-_Tp hmin(const simd<_Tp, _Abi>&);
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-hmin(const const_where_expression<_MaskType, _SimdType>&);
-template <class _Tp, class _Abi>
-_Tp hmax(const simd<_Tp, _Abi>&);
-template <class _MaskType, class _SimdType>
-typename _SimdType::value_type
-hmax(const const_where_expression<_MaskType, _SimdType>&);
-
-// algorithms [simd.alg]
-template <class _Tp, class _Abi>
-simd<_Tp, _Abi> min(const simd<_Tp, _Abi>&, const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-simd<_Tp, _Abi> max(const simd<_Tp, _Abi>&, const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-std::pair<simd<_Tp, _Abi>, simd<_Tp, _Abi>>
-minmax(const simd<_Tp, _Abi>&, const simd<_Tp, _Abi>&) noexcept;
-
-template <class _Tp, class _Abi>
-simd<_Tp, _Abi> clamp(const simd<_Tp, _Abi>&, const simd<_Tp, _Abi>&,
-                      const simd<_Tp, _Abi>&);
-
-// [simd.whereexpr]
-// TODO implement where expressions.
-template <class _MaskType, class _Tp>
-class const_where_expression {
-public:
-  const_where_expression(const const_where_expression&) = delete;
-  const_where_expression& operator=(const const_where_expression&) = delete;
-  typename remove_const<_Tp>::type operator-() const&&;
-  template <class _Up, class _Flags>
-  void copy_to(_Up*, _Flags) const&&;
-};
-
-template <class _MaskType, class _Tp>
-class where_expression : public const_where_expression<_MaskType, _Tp> {
-public:
-  where_expression(const where_expression&) = delete;
-  where_expression& operator=(const where_expression&) = delete;
-  template <class _Up>
-  void operator=(_Up&&);
-  template <class _Up>
-  void operator+=(_Up&&);
-  template <class _Up>
-  void operator-=(_Up&&);
-  template <class _Up>
-  void operator*=(_Up&&);
-  template <class _Up>
-  void operator/=(_Up&&);
-  template <class _Up>
-  void operator%=(_Up&&);
-  template <class _Up>
-  void operator&=(_Up&&);
-  template <class _Up>
-  void operator|=(_Up&&);
-  template <class _Up>
-  void operator^=(_Up&&);
-  template <class _Up>
-  void operator<<=(_Up&&);
-  template <class _Up>
-  void operator>>=(_Up&&);
-  void operator++();
-  void operator++(int);
-  void operator--();
-  void operator--(int);
-  template <class _Up, class _Flags>
-  void copy_from(const _Up*, _Flags);
-};
-
-// [simd.class]
-// TODO: implement simd
-template <class _Tp, class _Abi>
-class simd {
-public:
-  using value_type = _Tp;
-  using reference = __simd_reference<_Tp, _Tp, _Abi>;
-  using mask_type = simd_mask<_Tp, _Abi>;
-  using abi_type = _Abi;
-
-  simd() = default;
-  simd(const simd&) = default;
-  simd& operator=(const simd&) = default;
-
-  static constexpr size_t size() noexcept {
-    return simd_size<_Tp, _Abi>::value;
-  }
-
-private:
-  __simd_storage<_Tp, _Abi> __s_;
-
-  template <class _Up>
-  static constexpr bool __can_broadcast() {
-    return (std::is_arithmetic<_Up>::value &&
-            __is_non_narrowing_arithmetic_convertible<_Up, _Tp>()) ||
-           (!std::is_arithmetic<_Up>::value &&
-            std::is_convertible<_Up, _Tp>::value) ||
-           std::is_same<typename std::remove_const<_Up>::type, int>::value ||
-           (std::is_same<typename std::remove_const<_Up>::type,
-                         unsigned int>::value &&
-            std::is_unsigned<_Tp>::value);
-  }
-
-  template <class _Generator, size_t... __indicies>
-  static constexpr decltype(
-      std::forward_as_tuple(std::declval<_Generator>()(
-          std::integral_constant<size_t, __indicies>())...),
-      bool())
-  __can_generate(std::index_sequence<__indicies...>) {
-    return !__variadic_sum<bool>(
-        !__can_broadcast<decltype(std::declval<_Generator>()(
-            std::integral_constant<size_t, __indicies>()))>()...);
-  }
-
-  template <class _Generator>
-  static bool __can_generate(...) {
-    return false;
-  }
-
-  template <class _Generator, size_t... __indicies>
-  void __generator_init(_Generator&& __g, std::index_sequence<__indicies...>) {
-    int __not_used[]{((*this)[__indicies] =
-                          __g(std::integral_constant<size_t, __indicies>()),
-                      0)...};
-    (void)__not_used;
-  }
-
-public:
-  // implicit type conversion constructor
-  template <class _Up,
-            class = typename std::enable_if<
-                std::is_same<_Abi, simd_abi::fixed_size<size()>>::value &&
-                __is_non_narrowing_arithmetic_convertible<_Up, _Tp>()>::type>
-  simd(const simd<_Up, simd_abi::fixed_size<size()>>& __v) {
-    for (size_t __i = 0; __i < size(); __i++) {
-      (*this)[__i] = static_cast<_Tp>(__v[__i]);
-    }
-  }
-
-  // implicit broadcast constructor
-  template <class _Up,
-            class = typename std::enable_if<__can_broadcast<_Up>()>::type>
-  simd(_Up&& __rv) {
-    auto __v = static_cast<_Tp>(__rv);
-    for (size_t __i = 0; __i < size(); __i++) {
-      (*this)[__i] = __v;
-    }
-  }
-
-  // generator constructor
-  template <class _Generator,
-            int = typename std::enable_if<
-                __can_generate<_Generator>(std::make_index_sequence<size()>()),
-                int>::type()>
-  explicit simd(_Generator&& __g) {
-    __generator_init(std::forward<_Generator>(__g),
-                     std::make_index_sequence<size()>());
-  }
-
-  // load constructor
-  template <
-      class _Up, class _Flags,
-      class = typename std::enable_if<__vectorizable<_Up>()>::type,
-      class = typename std::enable_if<is_simd_flag_type<_Flags>::value>::type>
-  simd(const _Up* __buffer, _Flags) {
-    // TODO: optimize for overaligned flags
-    for (size_t __i = 0; __i < size(); __i++) {
-      (*this)[__i] = static_cast<_Tp>(__buffer[__i]);
-    }
-  }
-
-  // loads [simd.load]
-  template <class _Up, class _Flags>
-  typename std::enable_if<__vectorizable<_Up>() &&
-                          is_simd_flag_type<_Flags>::value>::type
-  copy_from(const _Up* __buffer, _Flags) {
-    *this = simd(__buffer, _Flags());
-  }
-
-  // stores [simd.store]
-  template <class _Up, class _Flags>
-  typename std::enable_if<__vectorizable<_Up>() &&
-                          is_simd_flag_type<_Flags>::value>::type
-  copy_to(_Up* __buffer, _Flags) const {
-    // TODO: optimize for overaligned flags
-    for (size_t __i = 0; __i < size(); __i++) {
-      __buffer[__i] = static_cast<_Up>((*this)[__i]);
-    }
-  }
-
-  // scalar access [simd.subscr]
-  reference operator[](size_t __i) { return reference(&__s_, __i); }
-
-  value_type operator[](size_t __i) const { return __s_.__get(__i); }
-
-  // unary operators [simd.unary]
-  simd& operator++();
-  simd operator++(int);
-  simd& operator--();
-  simd operator--(int);
-  mask_type operator!() const;
-  simd operator~() const;
-  simd operator+() const;
-  simd operator-() const;
-
-  // binary operators [simd.binary]
-  friend simd operator+(const simd&, const simd&);
-  friend simd operator-(const simd&, const simd&);
-  friend simd operator*(const simd&, const simd&);
-  friend simd operator/(const simd&, const simd&);
-  friend simd operator%(const simd&, const simd&);
-  friend simd operator&(const simd&, const simd&);
-  friend simd operator|(const simd&, const simd&);
-  friend simd operator^(const simd&, const simd&);
-  friend simd operator<<(const simd&, const simd&);
-  friend simd operator>>(const simd&, const simd&);
-  friend simd operator<<(const simd&, int);
-  friend simd operator>>(const simd&, int);
-
-  // compound assignment [simd.cassign]
-  friend simd& operator+=(simd&, const simd&);
-  friend simd& operator-=(simd&, const simd&);
-  friend simd& operator*=(simd&, const simd&);
-  friend simd& operator/=(simd&, const simd&);
-  friend simd& operator%=(simd&, const simd&);
-
-  friend simd& operator&=(simd&, const simd&);
-  friend simd& operator|=(simd&, const simd&);
-  friend simd& operator^=(simd&, const simd&);
-  friend simd& operator<<=(simd&, const simd&);
-  friend simd& operator>>=(simd&, const simd&);
-  friend simd& operator<<=(simd&, int);
-  friend simd& operator>>=(simd&, int);
-
-  // compares [simd.comparison]
-  friend mask_type operator==(const simd&, const simd&);
-  friend mask_type operator!=(const simd&, const simd&);
-  friend mask_type operator>=(const simd&, const simd&);
-  friend mask_type operator<=(const simd&, const simd&);
-  friend mask_type operator>(const simd&, const simd&);
-  friend mask_type operator<(const simd&, const simd&);
-};
-
-// [simd.mask.class]
-template <class _Tp, class _Abi>
-// TODO: implement simd_mask
-class simd_mask {
-public:
-  using value_type = bool;
-  // TODO: this is strawman implementation. Turn it into a proxy type.
-  using reference = bool&;
-  using simd_type = simd<_Tp, _Abi>;
-  using abi_type = _Abi;
-  static constexpr size_t size() noexcept;
-  simd_mask() = default;
-
-  // broadcast constructor
-  explicit simd_mask(value_type) noexcept;
-
-  // implicit type conversion constructor
-  template <class _Up>
-  simd_mask(const simd_mask<_Up, simd_abi::fixed_size<size()>>&) noexcept;
-
-  // load constructor
-  template <class _Flags>
-  simd_mask(const value_type*, _Flags);
-
-  // loads [simd.mask.copy]
-  template <class _Flags>
-  void copy_from(const value_type*, _Flags);
-  template <class _Flags>
-  void copy_to(value_type*, _Flags) const;
-
-  // scalar access [simd.mask.subscr]
-  reference operator[](size_t);
-  value_type operator[](size_t) const;
-
-  // unary operators [simd.mask.unary]
-  simd_mask operator!() const noexcept;
-
-  // simd_mask binary operators [simd.mask.binary]
-  friend simd_mask operator&&(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator||(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator&(const simd_mask&, const simd_mask&)noexcept;
-  friend simd_mask operator|(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator^(const simd_mask&, const simd_mask&) noexcept;
-
-  // simd_mask compound assignment [simd.mask.cassign]
-  friend simd_mask& operator&=(simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask& operator|=(simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask& operator^=(simd_mask&, const simd_mask&) noexcept;
-
-  // simd_mask compares [simd.mask.comparison]
-  friend simd_mask operator==(const simd_mask&, const simd_mask&) noexcept;
-  friend simd_mask operator!=(const simd_mask&, const simd_mask&) noexcept;
-};
-
-#endif // _LIBCPP_STD_VER >= 17
-
-_LIBCPP_END_NAMESPACE_EXPERIMENTAL_SIMD
-
-#endif /* _LIBCPP_EXPERIMENTAL_SIMD */
diff --git a/lib/libcxx/include/experimental/string b/lib/libcxx/include/experimental/string
deleted file mode 100644
index 8b8545128f2..00000000000
--- a/lib/libcxx/include/experimental/string
+++ /dev/null
@@ -1,62 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- string ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_STRING
-#define _LIBCPP_EXPERIMENTAL_STRING
-/*
-    experimental/string synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  // basic_string using polymorphic allocator in namespace pmr
-  template <class charT, class traits = char_traits<charT>>
-   using basic_string =
-     std::basic_string<charT, traits, polymorphic_allocator<charT>>;
-
-  // basic_string typedef names using polymorphic allocator in namespace
-  // std::experimental::pmr
-  typedef basic_string<char> string;
-  typedef basic_string<char16_t> u16string;
-  typedef basic_string<char32_t> u32string;
-  typedef basic_string<wchar_t> wstring;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <string>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _CharT, class _Traits = char_traits<_CharT>>
-using basic_string =
-    _VSTD::basic_string<_CharT, _Traits, polymorphic_allocator<_CharT>>;
-
-typedef basic_string<char> string;
-typedef basic_string<char16_t> u16string;
-typedef basic_string<char32_t> u32string;
-typedef basic_string<wchar_t> wstring;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_STRING */
diff --git a/lib/libcxx/include/experimental/string_view b/lib/libcxx/include/experimental/string_view
deleted file mode 100644
index 100bdfe7273..00000000000
--- a/lib/libcxx/include/experimental/string_view
+++ /dev/null
@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===------------------------ string_view ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_STRING_VIEW
-#define _LIBCPP_EXPERIMENTAL_STRING_VIEW
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/string_view> has been removed. Use <string_view> instead.")
-#else
-# warning "<experimental/string_view> has been removed. Use <string_view> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_STRING_VIEW
diff --git a/lib/libcxx/include/experimental/system_error b/lib/libcxx/include/experimental/system_error
deleted file mode 100644
index 1cf84ee0125..00000000000
--- a/lib/libcxx/include/experimental/system_error
+++ /dev/null
@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- system_error ------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_SYSTEM_ERROR
-#define _LIBCPP_EXPERIMENTAL_SYSTEM_ERROR
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/system_error> has been removed. Use <system_error> instead.")
-#else
-# warning "<experimental/system_error> has been removed. Use <system_error> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_SYSTEM_ERROR
diff --git a/lib/libcxx/include/experimental/tuple b/lib/libcxx/include/experimental/tuple
deleted file mode 100644
index 6d71bb559b0..00000000000
--- a/lib/libcxx/include/experimental/tuple
+++ /dev/null
@@ -1,21 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- tuple ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_EXPERIMENTAL_TUPLE
-#define _LIBCPP_EXPERIMENTAL_TUPLE
-
-#include <__config>
-
-#ifdef _LIBCPP_WARNING
-_LIBCPP_WARNING("<experimental/tuple> has been removed. Use <tuple> instead.")
-#else
-# warning "<experimental/tuple> has been removed. Use <tuple> instead."
-#endif
-
-#endif // _LIBCPP_EXPERIMENTAL_TUPLE
diff --git a/lib/libcxx/include/experimental/type_traits b/lib/libcxx/include/experimental/type_traits
deleted file mode 100644
index afe491567ce..00000000000
--- a/lib/libcxx/include/experimental/type_traits
+++ /dev/null
@@ -1,155 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- type_traits -------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_TYPE_TRAITS
-#define _LIBCPP_EXPERIMENTAL_TYPE_TRAITS
-
-/**
-    experimental/type_traits synopsis
-
-// C++1y
-#include <type_traits>
-
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-
-  // 3.3.2, Other type transformations
-  template <class> class invocation_type; // not defined
-  template <class F, class... ArgTypes> class invocation_type<F(ArgTypes...)>;
-  template <class> class raw_invocation_type; // not defined
-  template <class F, class... ArgTypes> class raw_invocation_type<F(ArgTypes...)>;
-
-  template <class T>
-    using invocation_type_t = typename invocation_type<T>::type;
-  template <class T>
-    using raw_invocation_type_t = typename raw_invocation_type<T>::type;
-
-  // 3.3.4, Detection idiom
-  template <class...> using void_t = void;
-
-  struct nonesuch {
-    nonesuch() = delete;
-    ~nonesuch() = delete;
-    nonesuch(nonesuch const&) = delete;
-    void operator=(nonesuch const&) = delete;
-  };
-
-  template <template<class...> class Op, class... Args>
-    using is_detected = see below;
-  template <template<class...> class Op, class... Args>
-    constexpr bool is_detected_v = is_detected<Op, Args...>::value;
-  template <template<class...> class Op, class... Args>
-    using detected_t = see below;
-  template <class Default, template<class...> class Op, class... Args>
-    using detected_or = see below;
-  template <class Default, template<class...> class Op, class... Args>
-    using detected_or_t = typename detected_or<Default, Op, Args...>::type;
-  template <class Expected, template<class...> class Op, class... Args>
-    using is_detected_exact = is_same<Expected, detected_t<Op, Args...>>;
-  template <class Expected, template<class...> class Op, class... Args>
-    constexpr bool is_detected_exact_v
-      = is_detected_exact<Expected, Op, Args...>::value;
-  template <class To, template<class...> class Op, class... Args>
-     using is_detected_convertible = is_convertible<detected_t<Op, Args...>, To>;
-  template <class To, template<class...> class Op, class... Args>
-     constexpr bool is_detected_convertible_v
-       = is_detected_convertible<To, Op, Args...>::value;  
-
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-
-#if _LIBCPP_STD_VER > 11
-
-#include <type_traits>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS
-
-// 3.3.2, Other type transformations
-/*
-template <class>
-class _LIBCPP_TEMPLATE_VIS raw_invocation_type;
-
-template <class _Fn, class ..._Args>
-class _LIBCPP_TEMPLATE_VIS raw_invocation_type<_Fn(_Args...)>;
-
-template <class>
-class _LIBCPP_TEMPLATE_VIS invokation_type;
-
-template <class _Fn, class ..._Args>
-class _LIBCPP_TEMPLATE_VIS invokation_type<_Fn(_Args...)>;
-
-template <class _Tp>
-using invokation_type_t = typename invokation_type<_Tp>::type;
-
-template <class _Tp>
-using raw_invocation_type_t = typename raw_invocation_type<_Tp>::type;
-*/
-
-// 3.3.4, Detection idiom
-template <class...> using void_t = void;
-
-struct nonesuch {
-    nonesuch()  = delete;
-    ~nonesuch() = delete;
-    nonesuch      (nonesuch const&) = delete;
-    void operator=(nonesuch const&) = delete;
-  };
-
-template <class _Default, class _AlwaysVoid, template <class...> class _Op, class... _Args>
-struct _DETECTOR {
-   using value_t = false_type;
-   using type = _Default;
-   };
-
-template <class _Default, template <class...> class _Op, class... _Args>
-struct _DETECTOR<_Default, void_t<_Op<_Args...>>, _Op, _Args...> {
-   using value_t = true_type;
-   using type = _Op<_Args...>;
-   };
-     
-
-template <template<class...> class _Op, class... _Args>
-  using is_detected = typename _DETECTOR<nonesuch, void, _Op, _Args...>::value_t;
-template <template<class...> class _Op, class... _Args>
-  using detected_t = typename _DETECTOR<nonesuch, void, _Op, _Args...>::type;
-template <template<class...> class _Op, class... _Args>
-  _LIBCPP_CONSTEXPR bool is_detected_v = is_detected<_Op, _Args...>::value;
-
-template <class Default, template<class...> class _Op, class... _Args>
-  using detected_or = _DETECTOR<Default, void, _Op, _Args...>;
-template <class Default, template<class...> class _Op, class... _Args>
-  using detected_or_t = typename detected_or<Default, _Op, _Args...>::type;
-
-template <class Expected, template<class...> class _Op, class... _Args>
-  using is_detected_exact = is_same<Expected, detected_t<_Op, _Args...>>;
-template <class Expected, template<class...> class _Op, class... _Args>
-  _LIBCPP_CONSTEXPR bool is_detected_exact_v = is_detected_exact<Expected, _Op, _Args...>::value;
-
-template <class To, template<class...> class _Op, class... _Args>
-  using is_detected_convertible = is_convertible<detected_t<_Op, _Args...>, To>;
-template <class To, template<class...> class _Op, class... _Args>
-  _LIBCPP_CONSTEXPR bool is_detected_convertible_v = is_detected_convertible<To, _Op, _Args...>::value;  
-
-
-_LIBCPP_END_NAMESPACE_LFTS
-
-#endif /* _LIBCPP_STD_VER > 11 */
-
-#endif /* _LIBCPP_EXPERIMENTAL_TYPE_TRAITS */
diff --git a/lib/libcxx/include/experimental/unordered_map b/lib/libcxx/include/experimental/unordered_map
deleted file mode 100644
index 1f998c2d4c7..00000000000
--- a/lib/libcxx/include/experimental/unordered_map
+++ /dev/null
@@ -1,65 +0,0 @@
-// -*- C++ -*-
-//===------------------------- unordered_map ------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_UNORDERED_MAP
-#define _LIBCPP_EXPERIMENTAL_UNORDERED_MAP
-/*
-    experimental/unordered_map synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  template <class Key, class T,
-            class Hash = hash<Key>,
-            class Pred = equal_to<Key>>
-  using unordered_map =
-    std::unordered_map<Key, T, Hash, Pred,
-                       polymorphic_allocator<pair<const Key,T>>>;
-
-  template <class Key, class T,
-            class Hash = hash<Key>,
-            class Pred = equal_to<Key>>
-  using unordered_multimap =
-    std::unordered_multimap<Key, T, Hash, Pred,
-                            polymorphic_allocator<pair<const Key,T>>>;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <unordered_map>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _Key, class _Value,
-          class _Hash = hash<_Key>, class _Pred = equal_to<_Key>>
-using unordered_map = _VSTD::unordered_map<_Key, _Value, _Hash, _Pred,
-                        polymorphic_allocator<pair<const _Key, _Value>>>;
-
-template <class _Key, class _Value,
-          class _Hash = hash<_Key>, class _Pred = equal_to<_Key>>
-using unordered_multimap = _VSTD::unordered_multimap<_Key, _Value, _Hash, _Pred,
-                        polymorphic_allocator<pair<const _Key, _Value>>>;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_UNORDERED_MAP */
diff --git a/lib/libcxx/include/experimental/unordered_set b/lib/libcxx/include/experimental/unordered_set
deleted file mode 100644
index d00a8375340..00000000000
--- a/lib/libcxx/include/experimental/unordered_set
+++ /dev/null
@@ -1,59 +0,0 @@
-// -*- C++ -*-
-//===------------------------- unordered_set ------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_UNORDERED_SET
-#define _LIBCPP_EXPERIMENTAL_UNORDERED_SET
-/*
-    experimental/unordered_set synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  template <class T, class Hash = hash<T>, class Pred = equal_to<T>>
-  using unordered_set = std::unordered_set<T, Hash, Pred,
-                       polymorphic_allocator<T>>;
-
-  template <class T, class Hash = hash<T>, class Pred = equal_to<T>>
-  using unordered_multiset = std::unordered_multiset<T, Hash, Pred,
-                       polymorphic_allocator<T>>;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <unordered_set>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _Value,
-          class _Hash = hash<_Value>, class _Pred = equal_to<_Value>>
-using unordered_set = _VSTD::unordered_set<_Value, _Hash, _Pred,
-                        polymorphic_allocator<_Value>>;
-
-template <class _Value,
-          class _Hash = hash<_Value>, class _Pred = equal_to<_Value>>
-using unordered_multiset = _VSTD::unordered_multiset<_Value, _Hash, _Pred,
-                        polymorphic_allocator<_Value>>;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_UNORDERED_SET */
diff --git a/lib/libcxx/include/experimental/utility b/lib/libcxx/include/experimental/utility
deleted file mode 100644
index 8effa71c131..00000000000
--- a/lib/libcxx/include/experimental/utility
+++ /dev/null
@@ -1,47 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- utility ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_UTILITY
-#define _LIBCPP_EXPERIMENTAL_UTILITY
-
-/*
-    experimental/utility synopsis
-
-// C++1y
-
-#include <utility>
-
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-
-  3.1.2, erased-type placeholder
-  struct erased_type { };
-
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <utility>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS
-
-  struct _LIBCPP_TEMPLATE_VIS erased_type { };
-
-_LIBCPP_END_NAMESPACE_LFTS
-
-#endif /* _LIBCPP_EXPERIMENTAL_UTILITY */
diff --git a/lib/libcxx/include/experimental/vector b/lib/libcxx/include/experimental/vector
deleted file mode 100644
index bd10492bfef..00000000000
--- a/lib/libcxx/include/experimental/vector
+++ /dev/null
@@ -1,47 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- vector ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXPERIMENTAL_VECTOR
-#define _LIBCPP_EXPERIMENTAL_VECTOR
-/*
-    experimental/vector synopsis
-
-// C++1z
-namespace std {
-namespace experimental {
-inline namespace fundamentals_v1 {
-namespace pmr {
-
-  template <class T>
-  using vector = std::vector<T, polymorphic_allocator<T>>;
-
-} // namespace pmr
-} // namespace fundamentals_v1
-} // namespace experimental
-} // namespace std
-
- */
-
-#include <experimental/__config>
-#include <vector>
-#include <experimental/memory_resource>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
-
-template <class _ValueT>
-using vector = _VSTD::vector<_ValueT, polymorphic_allocator<_ValueT>>;
-
-_LIBCPP_END_NAMESPACE_LFTS_PMR
-
-#endif /* _LIBCPP_EXPERIMENTAL_VECTOR */
diff --git a/lib/libcxx/include/ext/__hash b/lib/libcxx/include/ext/__hash
deleted file mode 100644
index 318cb1f97b0..00000000000
--- a/lib/libcxx/include/ext/__hash
+++ /dev/null
@@ -1,135 +0,0 @@
-// -*- C++ -*-
-//===------------------------- hash_set ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_EXT_HASH
-#define _LIBCPP_EXT_HASH
-
-#pragma GCC system_header
-
-#include <string>
-#include <cstring>
-
-namespace __gnu_cxx {
-using namespace std;
-
-template <typename _Tp> struct _LIBCPP_TEMPLATE_VIS hash { };
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<const char*>
-    : public unary_function<const char*, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const char *__c) const _NOEXCEPT
-    {
-        return __do_string_hash(__c, __c + strlen(__c));
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<char *>
-    : public unary_function<char*, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(char *__c) const _NOEXCEPT
-    {
-        return __do_string_hash<const char *>(__c, __c + strlen(__c));
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<char>
-    : public unary_function<char, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(char __c) const _NOEXCEPT
-    {
-        return __c;
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<signed char>
-    : public unary_function<signed char, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(signed char __c) const _NOEXCEPT
-    {
-        return __c;
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned char>
-    : public unary_function<unsigned char, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(unsigned char __c) const _NOEXCEPT
-    {
-        return __c;
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<short>
-    : public unary_function<short, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(short __c) const _NOEXCEPT
-    {
-        return __c;
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned short>
-    : public unary_function<unsigned short, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(unsigned short __c) const _NOEXCEPT
-    {
-        return __c;
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<int>
-    : public unary_function<int, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(int __c) const _NOEXCEPT
-    {
-        return __c;
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned int>
-    : public unary_function<unsigned int, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(unsigned int __c) const _NOEXCEPT
-    {
-        return __c;
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<long>
-    : public unary_function<long, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(long __c) const _NOEXCEPT
-    {
-        return __c;
-    }
-};
-
-template <> struct _LIBCPP_TEMPLATE_VIS hash<unsigned long>
-    : public unary_function<unsigned long, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(unsigned long __c) const _NOEXCEPT
-    {
-        return __c;
-    }
-};
-}
-
-#endif  // _LIBCPP_EXT_HASH
diff --git a/lib/libcxx/include/ext/hash_map b/lib/libcxx/include/ext/hash_map
deleted file mode 100644
index 998e8f65994..00000000000
--- a/lib/libcxx/include/ext/hash_map
+++ /dev/null
@@ -1,984 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- hash_map ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_HASH_MAP
-#define _LIBCPP_HASH_MAP
-
-/*
-
-    hash_map synopsis
-
-namespace __gnu_cxx
-{
-
-template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
-          class Alloc = allocator<pair<const Key, T>>>
-class hash_map
-{
-public:
-    // types
-    typedef Key                                                        key_type;
-    typedef T                                                          mapped_type;
-    typedef Hash                                                       hasher;
-    typedef Pred                                                       key_equal;
-    typedef Alloc                                                      allocator_type;
-    typedef pair<const key_type, mapped_type>                          value_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef /unspecified/ iterator;
-    typedef /unspecified/ const_iterator;
-
-    explicit hash_map(size_type n = 193, const hasher& hf = hasher(),
-                           const key_equal& eql = key_equal(),
-                           const allocator_type& a = allocator_type());
-    template <class InputIterator>
-        hash_map(InputIterator f, InputIterator l,
-                      size_type n = 193, const hasher& hf = hasher(),
-                      const key_equal& eql = key_equal(),
-                      const allocator_type& a = allocator_type());
-    hash_map(const hash_map&);
-    ~hash_map();
-    hash_map& operator=(const hash_map&);
-
-    allocator_type get_allocator() const;
-
-    bool      empty() const;
-    size_type size() const;
-    size_type max_size() const;
-
-    iterator       begin();
-    iterator       end();
-    const_iterator begin()  const;
-    const_iterator end()    const;
-
-    pair<iterator, bool> insert(const value_type& obj);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-
-    void erase(const_iterator position);
-    size_type erase(const key_type& k);
-    void erase(const_iterator first, const_iterator last);
-    void clear();
-
-    void swap(hash_map&);
-
-    hasher hash_funct() const;
-    key_equal key_eq() const;
-
-    iterator       find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    size_type count(const key_type& k) const;
-    pair<iterator, iterator>             equal_range(const key_type& k);
-    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
-
-    mapped_type& operator[](const key_type& k);
-
-    size_type bucket_count() const;
-    size_type max_bucket_count() const;
-
-    size_type elems_in_bucket(size_type n) const;
-
-    void resize(size_type n);
-};
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    void swap(hash_map<Key, T, Hash, Pred, Alloc>& x,
-              hash_map<Key, T, Hash, Pred, Alloc>& y);
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    bool
-    operator==(const hash_map<Key, T, Hash, Pred, Alloc>& x,
-               const hash_map<Key, T, Hash, Pred, Alloc>& y);
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    bool
-    operator!=(const hash_map<Key, T, Hash, Pred, Alloc>& x,
-               const hash_map<Key, T, Hash, Pred, Alloc>& y);
-
-template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
-          class Alloc = allocator<pair<const Key, T>>>
-class hash_multimap
-{
-public:
-    // types
-    typedef Key                                                        key_type;
-    typedef T                                                          mapped_type;
-    typedef Hash                                                       hasher;
-    typedef Pred                                                       key_equal;
-    typedef Alloc                                                      allocator_type;
-    typedef pair<const key_type, mapped_type>                          value_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef /unspecified/ iterator;
-    typedef /unspecified/ const_iterator;
-
-    explicit hash_multimap(size_type n = 193, const hasher& hf = hasher(),
-                           const key_equal& eql = key_equal(),
-                           const allocator_type& a = allocator_type());
-    template <class InputIterator>
-        hash_multimap(InputIterator f, InputIterator l,
-                      size_type n = 193, const hasher& hf = hasher(),
-                      const key_equal& eql = key_equal(),
-                      const allocator_type& a = allocator_type());
-    explicit hash_multimap(const allocator_type&);
-    hash_multimap(const hash_multimap&);
-    ~hash_multimap();
-    hash_multimap& operator=(const hash_multimap&);
-
-    allocator_type get_allocator() const;
-
-    bool      empty() const;
-    size_type size() const;
-    size_type max_size() const;
-
-    iterator       begin();
-    iterator       end();
-    const_iterator begin()  const;
-    const_iterator end()    const;
-
-    iterator insert(const value_type& obj);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-
-    void erase(const_iterator position);
-    size_type erase(const key_type& k);
-    void erase(const_iterator first, const_iterator last);
-    void clear();
-
-    void swap(hash_multimap&);
-
-    hasher hash_funct() const;
-    key_equal key_eq() const;
-
-    iterator       find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    size_type count(const key_type& k) const;
-    pair<iterator, iterator>             equal_range(const key_type& k);
-    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
-
-    size_type bucket_count() const;
-    size_type max_bucket_count() const;
-
-    size_type elems_in_bucket(size_type n) const;
-
-    void resize(size_type n);
-};
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    void swap(hash_multimap<Key, T, Hash, Pred, Alloc>& x,
-              hash_multimap<Key, T, Hash, Pred, Alloc>& y);
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    bool
-    operator==(const hash_multimap<Key, T, Hash, Pred, Alloc>& x,
-               const hash_multimap<Key, T, Hash, Pred, Alloc>& y);
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    bool
-    operator!=(const hash_multimap<Key, T, Hash, Pred, Alloc>& x,
-               const hash_multimap<Key, T, Hash, Pred, Alloc>& y);
-
-}  // __gnu_cxx
-
-*/
-
-#include <__config>
-#include <__hash_table>
-#include <functional>
-#include <stdexcept>
-#include <type_traits>
-#include <ext/__hash>
-
-#if __DEPRECATED
-#if defined(_LIBCPP_WARNING)
-    _LIBCPP_WARNING("Use of the header <ext/hash_map> is deprecated.  Migrate to <unordered_map>")
-#else
-#   warning Use of the header <ext/hash_map> is deprecated.  Migrate to <unordered_map>
-#endif
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-namespace __gnu_cxx {
-
-using namespace std;
-
-template <class _Tp, class _Hash,
-          bool = is_empty<_Hash>::value && !__libcpp_is_final<_Hash>::value
-        >
-class __hash_map_hasher
-    : private _Hash
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY __hash_map_hasher() : _Hash() {}
-    _LIBCPP_INLINE_VISIBILITY __hash_map_hasher(const _Hash& __h) : _Hash(__h) {}
-    _LIBCPP_INLINE_VISIBILITY const _Hash& hash_function() const {return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const _Tp& __x) const
-        {return static_cast<const _Hash&>(*this)(__x.first);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const typename _Tp::first_type& __x) const
-        {return static_cast<const _Hash&>(*this)(__x);}
-};
-
-template <class _Tp, class _Hash>
-class __hash_map_hasher<_Tp, _Hash, false>
-{
-    _Hash __hash_;
-public:
-    _LIBCPP_INLINE_VISIBILITY __hash_map_hasher() : __hash_() {}
-    _LIBCPP_INLINE_VISIBILITY __hash_map_hasher(const _Hash& __h) : __hash_(__h) {}
-    _LIBCPP_INLINE_VISIBILITY const _Hash& hash_function() const {return __hash_;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const _Tp& __x) const
-        {return __hash_(__x.first);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const typename _Tp::first_type& __x) const
-        {return __hash_(__x);}
-};
-
-template <class _Tp, class _Pred,
-          bool = is_empty<_Pred>::value && !__libcpp_is_final<_Pred>::value
-         >
-class __hash_map_equal
-    : private _Pred
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY __hash_map_equal() : _Pred() {}
-    _LIBCPP_INLINE_VISIBILITY __hash_map_equal(const _Pred& __p) : _Pred(__p) {}
-    _LIBCPP_INLINE_VISIBILITY const _Pred& key_eq() const {return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return static_cast<const _Pred&>(*this)(__x.first, __y.first);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const typename _Tp::first_type& __x, const _Tp& __y) const
-        {return static_cast<const _Pred&>(*this)(__x, __y.first);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const typename _Tp::first_type& __y) const
-        {return static_cast<const _Pred&>(*this)(__x.first, __y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const typename _Tp::first_type& __x,
-                    const typename _Tp::first_type& __y) const
-        {return static_cast<const _Pred&>(*this)(__x, __y);}
-};
-
-template <class _Tp, class _Pred>
-class __hash_map_equal<_Tp, _Pred, false>
-{
-    _Pred __pred_;
-public:
-    _LIBCPP_INLINE_VISIBILITY __hash_map_equal() : __pred_() {}
-    _LIBCPP_INLINE_VISIBILITY __hash_map_equal(const _Pred& __p) : __pred_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY const _Pred& key_eq() const {return __pred_;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return __pred_(__x.first, __y.first);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const typename _Tp::first_type& __x, const _Tp& __y) const
-        {return __pred_(__x, __y.first);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const typename _Tp::first_type& __y) const
-        {return __pred_(__x.first, __y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const typename _Tp::first_type& __x,
-                    const typename _Tp::first_type& __y) const
-        {return __pred_(__x, __y);}
-};
-
-template <class _Alloc>
-class __hash_map_node_destructor
-{
-    typedef _Alloc                              allocator_type;
-    typedef allocator_traits<allocator_type>    __alloc_traits;
-    typedef typename __alloc_traits::value_type::__node_value_type value_type;
-public:
-    typedef typename __alloc_traits::pointer    pointer;
-private:
-    typedef typename value_type::first_type     first_type;
-    typedef typename value_type::second_type    second_type;
-
-    allocator_type& __na_;
-
-    __hash_map_node_destructor& operator=(const __hash_map_node_destructor&);
-
-public:
-    bool __first_constructed;
-    bool __second_constructed;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __hash_map_node_destructor(allocator_type& __na)
-        : __na_(__na),
-          __first_constructed(false),
-          __second_constructed(false)
-        {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_node_destructor(__hash_node_destructor<allocator_type>&& __x)
-        : __na_(__x.__na_),
-          __first_constructed(__x.__value_constructed),
-          __second_constructed(__x.__value_constructed)
-        {
-            __x.__value_constructed = false;
-        }
-#else  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_node_destructor(const __hash_node_destructor<allocator_type>& __x)
-        : __na_(__x.__na_),
-          __first_constructed(__x.__value_constructed),
-          __second_constructed(__x.__value_constructed)
-        {
-            const_cast<bool&>(__x.__value_constructed) = false;
-        }
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()(pointer __p)
-    {
-        if (__second_constructed)
-            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.second));
-        if (__first_constructed)
-            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.first));
-        if (__p)
-            __alloc_traits::deallocate(__na_, __p, 1);
-    }
-};
-
-template <class _HashIterator>
-class _LIBCPP_TEMPLATE_VIS __hash_map_iterator
-{
-    _HashIterator __i_;
-
-    typedef const typename _HashIterator::value_type::first_type key_type;
-    typedef typename _HashIterator::value_type::second_type      mapped_type;
-public:
-    typedef forward_iterator_tag                                 iterator_category;
-    typedef pair<key_type, mapped_type>                          value_type;
-    typedef typename _HashIterator::difference_type              difference_type;
-    typedef value_type&                                          reference;
-    typedef typename __rebind_pointer<typename _HashIterator::pointer, value_type>::type
-        pointer;
-
-    _LIBCPP_INLINE_VISIBILITY __hash_map_iterator() {}
-
-    _LIBCPP_INLINE_VISIBILITY __hash_map_iterator(_HashIterator __i) : __i_(__i) {}
-
-    _LIBCPP_INLINE_VISIBILITY reference operator*() const {return *operator->();}
-    _LIBCPP_INLINE_VISIBILITY pointer operator->() const {return (pointer)__i_.operator->();}
-
-    _LIBCPP_INLINE_VISIBILITY __hash_map_iterator& operator++() {++__i_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_iterator operator++(int)
-    {
-        __hash_map_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY 
-    bool operator==(const __hash_map_iterator& __x, const __hash_map_iterator& __y)
-        {return __x.__i_ == __y.__i_;}
-    friend _LIBCPP_INLINE_VISIBILITY 
-    bool operator!=(const __hash_map_iterator& __x, const __hash_map_iterator& __y)
-        {return __x.__i_ != __y.__i_;}
-
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS hash_map;
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS hash_multimap;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
-};
-
-template <class _HashIterator>
-class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator
-{
-    _HashIterator __i_;
-
-    typedef const typename _HashIterator::value_type::first_type key_type;
-    typedef typename _HashIterator::value_type::second_type      mapped_type;
-public:
-    typedef forward_iterator_tag                                 iterator_category;
-    typedef pair<key_type, mapped_type>                          value_type;
-    typedef typename _HashIterator::difference_type              difference_type;
-    typedef const value_type&                                    reference;
-    typedef typename __rebind_pointer<typename _HashIterator::pointer, const value_type>::type
-        pointer;
-
-    _LIBCPP_INLINE_VISIBILITY __hash_map_const_iterator() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_const_iterator(_HashIterator __i) : __i_(__i) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_const_iterator(
-            __hash_map_iterator<typename _HashIterator::__non_const_iterator> __i)
-                : __i_(__i.__i_) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {return *operator->();}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {return (pointer)__i_.operator->();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_const_iterator& operator++() {++__i_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_const_iterator operator++(int)
-    {
-        __hash_map_const_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y)
-        {return __x.__i_ == __y.__i_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y)
-        {return __x.__i_ != __y.__i_;}
-
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS hash_map;
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS hash_multimap;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
-};
-
-template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = equal_to<_Key>,
-          class _Alloc = allocator<pair<const _Key, _Tp> > >
-class _LIBCPP_TEMPLATE_VIS hash_map
-{
-public:
-    // types
-    typedef _Key                                           key_type;
-    typedef _Tp                                            mapped_type;
-    typedef _Tp                                            data_type;
-    typedef _Hash                                          hasher;
-    typedef _Pred                                          key_equal;
-    typedef _Alloc                                         allocator_type;
-    typedef pair<const key_type, mapped_type>              value_type;
-    typedef value_type&                                    reference;
-    typedef const value_type&                              const_reference;
-
-private:
-    typedef pair<key_type, mapped_type>                    __value_type;
-    typedef __hash_map_hasher<__value_type, hasher>   __hasher;
-    typedef __hash_map_equal<__value_type, key_equal> __key_equal;
-    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>, __value_type>::type __allocator_type;
-
-    typedef __hash_table<__value_type, __hasher,
-                         __key_equal,  __allocator_type>   __table;
-
-    __table __table_;
-
-    typedef typename __table::__node_pointer               __node_pointer;
-    typedef typename __table::__node_const_pointer         __node_const_pointer;
-    typedef typename __table::__node_traits                __node_traits;
-    typedef typename __table::__node_allocator             __node_allocator;
-    typedef typename __table::__node                       __node;
-    typedef __hash_map_node_destructor<__node_allocator>   _Dp;
-    typedef unique_ptr<__node, _Dp>                         __node_holder;
-    typedef allocator_traits<allocator_type>               __alloc_traits;
-public:
-    typedef typename __alloc_traits::pointer         pointer;
-    typedef typename __alloc_traits::const_pointer   const_pointer;
-    typedef typename __alloc_traits::size_type       size_type;
-    typedef typename __alloc_traits::difference_type difference_type;
-
-    typedef __hash_map_iterator<typename __table::iterator>       iterator;
-    typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY hash_map() {__table_.rehash(193);}
-    explicit hash_map(size_type __n, const hasher& __hf = hasher(),
-                           const key_equal& __eql = key_equal());
-    hash_map(size_type __n, const hasher& __hf,
-                  const key_equal& __eql,
-                  const allocator_type& __a);
-    template <class _InputIterator>
-        hash_map(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        hash_map(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf = hasher(),
-                      const key_equal& __eql = key_equal());
-    template <class _InputIterator>
-        hash_map(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf,
-                      const key_equal& __eql,
-                      const allocator_type& __a);
-    hash_map(const hash_map& __u);
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const
-        {return allocator_type(__table_.__node_alloc());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const {return __table_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const  {return __table_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const {return __table_.max_size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin()        {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end()          {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const {return __table_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> insert(const value_type& __x)
-        {return __table_.__insert_unique(__x);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator, const value_type& __x) {return insert(__x).first;}
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __first, _InputIterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void erase(const_iterator __p) {__table_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __table_.__erase_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    void erase(const_iterator __first, const_iterator __last)
-        {__table_.erase(__first.__i_, __last.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() {__table_.clear();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(hash_map& __u) {__table_.swap(__u.__table_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    hasher hash_funct() const
-        {return __table_.hash_function().hash_function();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_equal key_eq() const
-        {return __table_.key_eq().key_eq();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       find(const key_type& __k)       {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type count(const key_type& __k) const {return __table_.__count_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
-        {return __table_.__equal_range_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
-        {return __table_.__equal_range_unique(__k);}
-
-    mapped_type& operator[](const key_type& __k);
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_count() const {return __table_.bucket_count();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_bucket_count() const {return __table_.max_bucket_count();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type elems_in_bucket(size_type __n) const
-        {return __table_.bucket_size(__n);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void resize(size_type __n) {__table_.rehash(__n);}
-
-private:
-    __node_holder __construct_node(const key_type& __k);
-};
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
-        size_type __n, const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-    __table_.rehash(__n);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
-        size_type __n, const hasher& __hf, const key_equal& __eql,
-        const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-    __table_.rehash(__n);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
-        _InputIterator __first, _InputIterator __last)
-{
-    __table_.rehash(193);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_map(
-        const hash_map& __u)
-    : __table_(__u.__table_)
-{
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-typename hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
-hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node(const key_type& __k)
-{
-    __node_allocator& __na = __table_.__node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.first), __k);
-    __h.get_deleter().__first_constructed = true;
-    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.second));
-    __h.get_deleter().__second_constructed = true;
-    return _LIBCPP_EXPLICIT_MOVE(__h);  // explicitly moved for C++03
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-inline
-void
-hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
-                                                       _InputIterator __last)
-{
-    for (; __first != __last; ++__first)
-        __table_.__insert_unique(*__first);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-_Tp&
-hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](const key_type& __k)
-{
-    iterator __i = find(__k);
-    if (__i != end())
-        return __i->second;
-    __node_holder __h = __construct_node(__k);
-    pair<iterator, bool> __r = __table_.__node_insert_unique(__h.get());
-    __h.release();
-    return __r.first->second;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-     hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-bool
-operator==(const hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-           const hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    if (__x.size() != __y.size())
-        return false;
-    typedef typename hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator
-                                                                 const_iterator;
-    for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end();
-            __i != __ex; ++__i)
-    {
-        const_iterator __j = __y.find(__i->first);
-        if (__j == __ey || !(*__i == *__j))
-            return false;
-    }
-    return true;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-           const hash_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = equal_to<_Key>,
-          class _Alloc = allocator<pair<const _Key, _Tp> > >
-class _LIBCPP_TEMPLATE_VIS hash_multimap
-{
-public:
-    // types
-    typedef _Key                                           key_type;
-    typedef _Tp                                            mapped_type;
-    typedef _Tp                                            data_type;
-    typedef _Hash                                          hasher;
-    typedef _Pred                                          key_equal;
-    typedef _Alloc                                         allocator_type;
-    typedef pair<const key_type, mapped_type>              value_type;
-    typedef value_type&                                    reference;
-    typedef const value_type&                              const_reference;
-
-private:
-    typedef pair<key_type, mapped_type>                    __value_type;
-    typedef __hash_map_hasher<__value_type, hasher>   __hasher;
-    typedef __hash_map_equal<__value_type, key_equal> __key_equal;
-    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>, __value_type>::type __allocator_type;
-
-    typedef __hash_table<__value_type, __hasher,
-                         __key_equal,  __allocator_type>   __table;
-
-    __table __table_;
-
-    typedef typename __table::__node_traits                __node_traits;
-    typedef typename __table::__node_allocator             __node_allocator;
-    typedef typename __table::__node                       __node;
-    typedef __hash_map_node_destructor<__node_allocator>   _Dp;
-    typedef unique_ptr<__node, _Dp>                         __node_holder;
-    typedef allocator_traits<allocator_type>               __alloc_traits;
-public:
-    typedef typename __alloc_traits::pointer         pointer;
-    typedef typename __alloc_traits::const_pointer   const_pointer;
-    typedef typename __alloc_traits::size_type       size_type;
-    typedef typename __alloc_traits::difference_type difference_type;
-
-    typedef __hash_map_iterator<typename __table::iterator>       iterator;
-    typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    hash_multimap() {__table_.rehash(193);}
-    explicit hash_multimap(size_type __n, const hasher& __hf = hasher(),
-                                const key_equal& __eql = key_equal());
-    hash_multimap(size_type __n, const hasher& __hf,
-                                const key_equal& __eql,
-                                const allocator_type& __a);
-    template <class _InputIterator>
-        hash_multimap(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        hash_multimap(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf = hasher(),
-                      const key_equal& __eql = key_equal());
-    template <class _InputIterator>
-        hash_multimap(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf,
-                      const key_equal& __eql,
-                      const allocator_type& __a);
-    hash_multimap(const hash_multimap& __u);
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const
-        {return allocator_type(__table_.__node_alloc());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const {return __table_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const  {return __table_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const {return __table_.max_size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin()        {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end()          {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const {return __table_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const value_type& __x) {return __table_.__insert_multi(__x);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator, const value_type& __x) {return insert(__x);}
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __first, _InputIterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void erase(const_iterator __p) {__table_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __table_.__erase_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    void erase(const_iterator __first, const_iterator __last)
-        {__table_.erase(__first.__i_, __last.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() {__table_.clear();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(hash_multimap& __u) {__table_.swap(__u.__table_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    hasher hash_funct() const
-        {return __table_.hash_function().hash_function();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_equal key_eq() const
-        {return __table_.key_eq().key_eq();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       find(const key_type& __k)       {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type count(const key_type& __k) const {return __table_.__count_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
-        {return __table_.__equal_range_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
-        {return __table_.__equal_range_multi(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_count() const {return __table_.bucket_count();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_bucket_count() const {return __table_.max_bucket_count();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type elems_in_bucket(size_type __n) const
-        {return __table_.bucket_size(__n);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void resize(size_type __n) {__table_.rehash(__n);}
-};
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
-        size_type __n, const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-    __table_.rehash(__n);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
-        size_type __n, const hasher& __hf, const key_equal& __eql,
-        const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-    __table_.rehash(__n);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
-        _InputIterator __first, _InputIterator __last)
-{
-    __table_.rehash(193);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::hash_multimap(
-        const hash_multimap& __u)
-    : __table_(__u.__table_)
-{
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-inline
-void
-hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
-                                                            _InputIterator __last)
-{
-    for (; __first != __last; ++__first)
-        __table_.__insert_multi(*__first);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-     hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-bool
-operator==(const hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-           const hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    if (__x.size() != __y.size())
-        return false;
-    typedef typename hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator
-                                                                 const_iterator;
-    typedef pair<const_iterator, const_iterator> _EqRng;
-    for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
-    {
-        _EqRng __xeq = __x.equal_range(__i->first);
-        _EqRng __yeq = __y.equal_range(__i->first);
-        if (_VSTD::distance(__xeq.first, __xeq.second) !=
-            _VSTD::distance(__yeq.first, __yeq.second) ||
-                  !_VSTD::is_permutation(__xeq.first, __xeq.second, __yeq.first))
-            return false;
-        __i = __xeq.second;
-    }
-    return true;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-           const hash_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-} // __gnu_cxx
-
-#endif  // _LIBCPP_HASH_MAP
diff --git a/lib/libcxx/include/ext/hash_set b/lib/libcxx/include/ext/hash_set
deleted file mode 100644
index 38f81ed3b5c..00000000000
--- a/lib/libcxx/include/ext/hash_set
+++ /dev/null
@@ -1,663 +0,0 @@
-// -*- C++ -*-
-//===------------------------- hash_set ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_HASH_SET
-#define _LIBCPP_HASH_SET
-
-/*
-
-    hash_set synopsis
-
-namespace __gnu_cxx
-{
-
-template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
-          class Alloc = allocator<Value>>
-class hash_set
-{
-public:
-    // types
-    typedef Value                                                      key_type;
-    typedef key_type                                                   value_type;
-    typedef Hash                                                       hasher;
-    typedef Pred                                                       key_equal;
-    typedef Alloc                                                      allocator_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef /unspecified/ iterator;
-    typedef /unspecified/ const_iterator;
-
-    explicit hash_set(size_type n = 193, const hasher& hf = hasher(),
-                           const key_equal& eql = key_equal(),
-                           const allocator_type& a = allocator_type());
-    template <class InputIterator>
-        hash_set(InputIterator f, InputIterator l,
-                      size_type n = 193, const hasher& hf = hasher(),
-                      const key_equal& eql = key_equal(),
-                      const allocator_type& a = allocator_type());
-    hash_set(const hash_set&);
-    ~hash_set();
-    hash_set& operator=(const hash_set&);
-
-    allocator_type get_allocator() const;
-
-    bool      empty() const;
-    size_type size() const;
-    size_type max_size() const;
-
-    iterator       begin();
-    iterator       end();
-    const_iterator begin()  const;
-    const_iterator end()    const;
-
-    pair<iterator, bool> insert(const value_type& obj);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-
-    void erase(const_iterator position);
-    size_type erase(const key_type& k);
-    void erase(const_iterator first, const_iterator last);
-    void clear();
-
-    void swap(hash_set&);
-
-    hasher hash_funct() const;
-    key_equal key_eq() const;
-
-    iterator       find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    size_type count(const key_type& k) const;
-    pair<iterator, iterator>             equal_range(const key_type& k);
-    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
-
-    size_type bucket_count() const;
-    size_type max_bucket_count() const;
-
-    size_type elems_in_bucket(size_type n) const;
-
-    void resize(size_type n);
-};
-
-template <class Value, class Hash, class Pred, class Alloc>
-    void swap(hash_set<Value, Hash, Pred, Alloc>& x,
-              hash_set<Value, Hash, Pred, Alloc>& y);
-
-template <class Value, class Hash, class Pred, class Alloc>
-    bool
-    operator==(const hash_set<Value, Hash, Pred, Alloc>& x,
-               const hash_set<Value, Hash, Pred, Alloc>& y);
-
-template <class Value, class Hash, class Pred, class Alloc>
-    bool
-    operator!=(const hash_set<Value, Hash, Pred, Alloc>& x,
-               const hash_set<Value, Hash, Pred, Alloc>& y);
-
-template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
-          class Alloc = allocator<Value>>
-class hash_multiset
-{
-public:
-    // types
-    typedef Value                                                      key_type;
-    typedef key_type                                                   value_type;
-    typedef Hash                                                       hasher;
-    typedef Pred                                                       key_equal;
-    typedef Alloc                                                      allocator_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef /unspecified/ iterator;
-    typedef /unspecified/ const_iterator;
-
-    explicit hash_multiset(size_type n = 193, const hasher& hf = hasher(),
-                           const key_equal& eql = key_equal(),
-                           const allocator_type& a = allocator_type());
-    template <class InputIterator>
-        hash_multiset(InputIterator f, InputIterator l,
-                      size_type n = 193, const hasher& hf = hasher(),
-                      const key_equal& eql = key_equal(),
-                      const allocator_type& a = allocator_type());
-    hash_multiset(const hash_multiset&);
-    ~hash_multiset();
-    hash_multiset& operator=(const hash_multiset&);
-
-    allocator_type get_allocator() const;
-
-    bool      empty() const;
-    size_type size() const;
-    size_type max_size() const;
-
-    iterator       begin();
-    iterator       end();
-    const_iterator begin()  const;
-    const_iterator end()    const;
-
-    iterator insert(const value_type& obj);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-
-    void erase(const_iterator position);
-    size_type erase(const key_type& k);
-    void erase(const_iterator first, const_iterator last);
-    void clear();
-
-    void swap(hash_multiset&);
-
-    hasher hash_funct() const;
-    key_equal key_eq() const;
-
-    iterator       find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    size_type count(const key_type& k) const;
-    pair<iterator, iterator>             equal_range(const key_type& k);
-    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
-
-    size_type bucket_count() const;
-    size_type max_bucket_count() const;
-
-    size_type elems_in_bucket(size_type n) const;
-
-    void resize(size_type n);
-};
-
-template <class Value, class Hash, class Pred, class Alloc>
-    void swap(hash_multiset<Value, Hash, Pred, Alloc>& x,
-              hash_multiset<Value, Hash, Pred, Alloc>& y);
-
-template <class Value, class Hash, class Pred, class Alloc>
-    bool
-    operator==(const hash_multiset<Value, Hash, Pred, Alloc>& x,
-               const hash_multiset<Value, Hash, Pred, Alloc>& y);
-
-template <class Value, class Hash, class Pred, class Alloc>
-    bool
-    operator!=(const hash_multiset<Value, Hash, Pred, Alloc>& x,
-               const hash_multiset<Value, Hash, Pred, Alloc>& y);
-}  // __gnu_cxx
-
-*/
-
-#include <__config>
-#include <__hash_table>
-#include <functional>
-#include <ext/__hash>
-
-#if __DEPRECATED
-#if defined(_LIBCPP_WARNING)
-    _LIBCPP_WARNING("Use of the header <ext/hash_set> is deprecated.  Migrate to <unordered_set>")
-#else
-#   warning Use of the header <ext/hash_set> is deprecated.  Migrate to <unordered_set>
-#endif
-#endif
-
-namespace __gnu_cxx {
-
-using namespace std;
-
-template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
-          class _Alloc = allocator<_Value> >
-class _LIBCPP_TEMPLATE_VIS hash_set
-{
-public:
-    // types
-    typedef _Value                                                     key_type;
-    typedef key_type                                                   value_type;
-    typedef _Hash                                                      hasher;
-    typedef _Pred                                                      key_equal;
-    typedef _Alloc                                                     allocator_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-
-private:
-    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
-
-    __table __table_;
-
-public:
-    typedef typename __table::pointer         pointer;
-    typedef typename __table::const_pointer   const_pointer;
-    typedef typename __table::size_type       size_type;
-    typedef typename __table::difference_type difference_type;
-
-    typedef typename __table::const_iterator       iterator;
-    typedef typename __table::const_iterator       const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    hash_set() {__table_.rehash(193);}
-    explicit hash_set(size_type __n, const hasher& __hf = hasher(),
-                           const key_equal& __eql = key_equal());
-    hash_set(size_type __n, const hasher& __hf, const key_equal& __eql,
-                  const allocator_type& __a);
-    template <class _InputIterator>
-        hash_set(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        hash_set(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf = hasher(),
-                      const key_equal& __eql = key_equal());
-    template <class _InputIterator>
-        hash_set(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf, const key_equal& __eql,
-                      const allocator_type& __a);
-    hash_set(const hash_set& __u);
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const
-        {return allocator_type(__table_.__node_alloc());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const {return __table_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const  {return __table_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const {return __table_.max_size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin()        {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end()          {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const {return __table_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> insert(const value_type& __x)
-        {return __table_.__insert_unique(__x);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator, const value_type& __x) {return insert(__x).first;}
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __first, _InputIterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void erase(const_iterator __p) {__table_.erase(__p);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __table_.__erase_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    void erase(const_iterator __first, const_iterator __last)
-        {__table_.erase(__first, __last);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() {__table_.clear();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(hash_set& __u) {__table_.swap(__u.__table_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    hasher hash_funct() const {return __table_.hash_function();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_equal key_eq() const {return __table_.key_eq();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       find(const key_type& __k)       {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type count(const key_type& __k) const {return __table_.__count_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
-        {return __table_.__equal_range_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
-        {return __table_.__equal_range_unique(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_count() const {return __table_.bucket_count();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_bucket_count() const {return __table_.max_bucket_count();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type elems_in_bucket(size_type __n) const {return __table_.bucket_size(__n);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void resize(size_type __n) {__table_.rehash(__n);}
-};
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-    __table_.rehash(__n);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-    __table_.rehash(__n);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
-        _InputIterator __first, _InputIterator __last)
-{
-    __table_.rehash(193);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
-        const hash_set& __u)
-    : __table_(__u.__table_)
-{
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-inline
-void
-hash_set<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
-                                                    _InputIterator __last)
-{
-    for (; __first != __last; ++__first)
-        __table_.__insert_unique(*__first);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(hash_set<_Value, _Hash, _Pred, _Alloc>& __x,
-     hash_set<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-bool
-operator==(const hash_set<_Value, _Hash, _Pred, _Alloc>& __x,
-           const hash_set<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    if (__x.size() != __y.size())
-        return false;
-    typedef typename hash_set<_Value, _Hash, _Pred, _Alloc>::const_iterator
-                                                                 const_iterator;
-    for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end();
-            __i != __ex; ++__i)
-    {
-        const_iterator __j = __y.find(*__i);
-        if (__j == __ey || !(*__i == *__j))
-            return false;
-    }
-    return true;
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const hash_set<_Value, _Hash, _Pred, _Alloc>& __x,
-           const hash_set<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
-          class _Alloc = allocator<_Value> >
-class _LIBCPP_TEMPLATE_VIS hash_multiset
-{
-public:
-    // types
-    typedef _Value                                                     key_type;
-    typedef key_type                                                   value_type;
-    typedef _Hash                                                      hasher;
-    typedef _Pred                                                      key_equal;
-    typedef _Alloc                                                     allocator_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-
-private:
-    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
-
-    __table __table_;
-
-public:
-    typedef typename __table::pointer         pointer;
-    typedef typename __table::const_pointer   const_pointer;
-    typedef typename __table::size_type       size_type;
-    typedef typename __table::difference_type difference_type;
-
-    typedef typename __table::const_iterator       iterator;
-    typedef typename __table::const_iterator       const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    hash_multiset() {__table_.rehash(193);}
-    explicit hash_multiset(size_type __n, const hasher& __hf = hasher(),
-                                const key_equal& __eql = key_equal());
-    hash_multiset(size_type __n, const hasher& __hf,
-                       const key_equal& __eql, const allocator_type& __a);
-    template <class _InputIterator>
-        hash_multiset(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        hash_multiset(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf = hasher(),
-                      const key_equal& __eql = key_equal());
-    template <class _InputIterator>
-        hash_multiset(_InputIterator __first, _InputIterator __last,
-                      size_type __n , const hasher& __hf,
-                      const key_equal& __eql, const allocator_type& __a);
-    hash_multiset(const hash_multiset& __u);
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const
-        {return allocator_type(__table_.__node_alloc());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const {return __table_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const  {return __table_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const {return __table_.max_size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin()        {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end()          {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const {return __table_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const value_type& __x) {return __table_.__insert_multi(__x);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator, const value_type& __x) {return insert(__x);}
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __first, _InputIterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void erase(const_iterator __p) {__table_.erase(__p);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __table_.__erase_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    void erase(const_iterator __first, const_iterator __last)
-        {__table_.erase(__first, __last);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() {__table_.clear();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(hash_multiset& __u) {__table_.swap(__u.__table_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    hasher hash_funct() const {return __table_.hash_function();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_equal key_eq() const {return __table_.key_eq();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       find(const key_type& __k)       {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type count(const key_type& __k) const {return __table_.__count_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
-        {return __table_.__equal_range_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
-        {return __table_.__equal_range_multi(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_count() const {return __table_.bucket_count();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_bucket_count() const {return __table_.max_bucket_count();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type elems_in_bucket(size_type __n) const {return __table_.bucket_size(__n);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void resize(size_type __n) {__table_.rehash(__n);}
-};
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
-        size_type __n, const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-    __table_.rehash(__n);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
-        size_type __n, const hasher& __hf, const key_equal& __eql,
-        const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-    __table_.rehash(__n);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
-        _InputIterator __first, _InputIterator __last)
-{
-    __table_.rehash(193);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
-        const hash_multiset& __u)
-    : __table_(__u.__table_)
-{
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-inline
-void
-hash_multiset<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
-                                                         _InputIterator __last)
-{
-    for (; __first != __last; ++__first)
-        __table_.__insert_multi(*__first);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
-     hash_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-bool
-operator==(const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
-           const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    if (__x.size() != __y.size())
-        return false;
-    typedef typename hash_multiset<_Value, _Hash, _Pred, _Alloc>::const_iterator
-                                                                 const_iterator;
-    typedef pair<const_iterator, const_iterator> _EqRng;
-    for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
-    {
-        _EqRng __xeq = __x.equal_range(*__i);
-        _EqRng __yeq = __y.equal_range(*__i);
-        if (_VSTD::distance(__xeq.first, __xeq.second) !=
-            _VSTD::distance(__yeq.first, __yeq.second) ||
-                  !_VSTD::is_permutation(__xeq.first, __xeq.second, __yeq.first))
-            return false;
-        __i = __xeq.second;
-    }
-    return true;
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
-           const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-} // __gnu_cxx
-
-#endif  // _LIBCPP_HASH_SET
diff --git a/lib/libcxx/include/filesystem b/lib/libcxx/include/filesystem
deleted file mode 100644
index af713a06358..00000000000
--- a/lib/libcxx/include/filesystem
+++ /dev/null
@@ -1,2637 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- filesystem -------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_FILESYSTEM
-#define _LIBCPP_FILESYSTEM
-/*
-    filesystem synopsis
-
-    namespace std { namespace filesystem {
-
-    class path;
-
-    void swap(path& lhs, path& rhs) noexcept;
-    size_t hash_value(const path& p) noexcept;
-
-    bool operator==(const path& lhs, const path& rhs) noexcept;
-    bool operator!=(const path& lhs, const path& rhs) noexcept;
-    bool operator< (const path& lhs, const path& rhs) noexcept;
-    bool operator<=(const path& lhs, const path& rhs) noexcept;
-    bool operator> (const path& lhs, const path& rhs) noexcept;
-    bool operator>=(const path& lhs, const path& rhs) noexcept;
-
-    path operator/ (const path& lhs, const path& rhs);
-
-    // fs.path.io operators are friends of path.
-    template <class charT, class traits>
-    friend basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os, const path& p);
-
-    template <class charT, class traits>
-    friend basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is, path& p);
-
-    template <class Source>
-      path u8path(const Source& source);
-    template <class InputIterator>
-      path u8path(InputIterator first, InputIterator last);
-
-    class filesystem_error;
-    class directory_entry;
-
-    class directory_iterator;
-
-    // enable directory_iterator range-based for statements
-    directory_iterator begin(directory_iterator iter) noexcept;
-    directory_iterator end(const directory_iterator&) noexcept;
-
-    class recursive_directory_iterator;
-
-    // enable recursive_directory_iterator range-based for statements
-    recursive_directory_iterator begin(recursive_directory_iterator iter) noexcept;
-    recursive_directory_iterator end(const recursive_directory_iterator&) noexcept;
-
-    class file_status;
-
-    struct space_info
-    {
-      uintmax_t capacity;
-      uintmax_t free;
-      uintmax_t available;
-    };
-
-    enum class file_type;
-    enum class perms;
-    enum class perm_options;
-    enum class copy_options;
-    enum class directory_options;
-
-    typedef chrono::time_point<trivial-clock>  file_time_type;
-
-    // operational functions
-
-    path absolute(const path& p);
-    path absolute(const path& p, error_code &ec);
-
-    path canonical(const path& p);
-    path canonical(const path& p, error_code& ec);
-
-    void copy(const path& from, const path& to);
-    void copy(const path& from, const path& to, error_code& ec);
-    void copy(const path& from, const path& to, copy_options options);
-    void copy(const path& from, const path& to, copy_options options,
-                   error_code& ec);
-
-    bool copy_file(const path& from, const path& to);
-    bool copy_file(const path& from, const path& to, error_code& ec);
-    bool copy_file(const path& from, const path& to, copy_options option);
-    bool copy_file(const path& from, const path& to, copy_options option,
-                           error_code& ec);
-
-    void copy_symlink(const path& existing_symlink, const path& new_symlink);
-    void copy_symlink(const path& existing_symlink, const path& new_symlink,
-                              error_code& ec) noexcept;
-
-    bool create_directories(const path& p);
-    bool create_directories(const path& p, error_code& ec);
-
-    bool create_directory(const path& p);
-    bool create_directory(const path& p, error_code& ec) noexcept;
-
-    bool create_directory(const path& p, const path& attributes);
-    bool create_directory(const path& p, const path& attributes,
-                                  error_code& ec) noexcept;
-
-    void create_directory_symlink(const path& to, const path& new_symlink);
-    void create_directory_symlink(const path& to, const path& new_symlink,
-                                          error_code& ec) noexcept;
-
-    void create_hard_link(const path& to, const path& new_hard_link);
-    void create_hard_link(const path& to, const path& new_hard_link,
-                                  error_code& ec) noexcept;
-
-    void create_symlink(const path& to, const path& new_symlink);
-    void create_symlink(const path& to, const path& new_symlink,
-                                error_code& ec) noexcept;
-
-    path current_path();
-    path current_path(error_code& ec);
-    void current_path(const path& p);
-    void current_path(const path& p, error_code& ec) noexcept;
-
-    bool exists(file_status s) noexcept;
-    bool exists(const path& p);
-    bool exists(const path& p, error_code& ec) noexcept;
-
-    bool equivalent(const path& p1, const path& p2);
-    bool equivalent(const path& p1, const path& p2, error_code& ec) noexcept;
-
-    uintmax_t    file_size(const path& p);
-    uintmax_t    file_size(const path& p, error_code& ec) noexcept;
-
-    uintmax_t    hard_link_count(const path& p);
-    uintmax_t    hard_link_count(const path& p, error_code& ec) noexcept;
-
-    bool is_block_file(file_status s) noexcept;
-    bool is_block_file(const path& p);
-    bool is_block_file(const path& p, error_code& ec) noexcept;
-
-    bool is_character_file(file_status s) noexcept;
-    bool is_character_file(const path& p);
-    bool is_character_file(const path& p, error_code& ec) noexcept;
-
-    bool is_directory(file_status s) noexcept;
-    bool is_directory(const path& p);
-    bool is_directory(const path& p, error_code& ec) noexcept;
-
-    bool is_empty(const path& p);
-    bool is_empty(const path& p, error_code& ec) noexcept;
-
-    bool is_fifo(file_status s) noexcept;
-    bool is_fifo(const path& p);
-    bool is_fifo(const path& p, error_code& ec) noexcept;
-
-    bool is_other(file_status s) noexcept;
-    bool is_other(const path& p);
-    bool is_other(const path& p, error_code& ec) noexcept;
-
-    bool is_regular_file(file_status s) noexcept;
-    bool is_regular_file(const path& p);
-    bool is_regular_file(const path& p, error_code& ec) noexcept;
-
-    bool is_socket(file_status s) noexcept;
-    bool is_socket(const path& p);
-    bool is_socket(const path& p, error_code& ec) noexcept;
-
-    bool is_symlink(file_status s) noexcept;
-    bool is_symlink(const path& p);
-    bool is_symlink(const path& p, error_code& ec) noexcept;
-
-    file_time_type  last_write_time(const path& p);
-    file_time_type  last_write_time(const path& p, error_code& ec) noexcept;
-    void last_write_time(const path& p, file_time_type new_time);
-    void last_write_time(const path& p, file_time_type new_time,
-                                 error_code& ec) noexcept;
-
-    void permissions(const path& p, perms prms,
-                     perm_options opts=perm_options::replace);
-    void permissions(const path& p, perms prms, error_code& ec) noexcept;
-    void permissions(const path& p, perms prms, perm_options opts,
-                     error_code& ec);
-
-    path proximate(const path& p, error_code& ec);
-    path proximate(const path& p, const path& base = current_path());
-    path proximate(const path& p, const path& base, error_code &ec);
-
-    path read_symlink(const path& p);
-    path read_symlink(const path& p, error_code& ec);
-
-    path relative(const path& p, error_code& ec);
-    path relative(const path& p, const path& base=current_path());
-    path relative(const path& p, const path& base, error_code& ec);
-
-    bool remove(const path& p);
-    bool remove(const path& p, error_code& ec) noexcept;
-
-    uintmax_t    remove_all(const path& p);
-    uintmax_t    remove_all(const path& p, error_code& ec);
-
-    void rename(const path& from, const path& to);
-    void rename(const path& from, const path& to, error_code& ec) noexcept;
-
-    void resize_file(const path& p, uintmax_t size);
-    void resize_file(const path& p, uintmax_t size, error_code& ec) noexcept;
-
-    space_info   space(const path& p);
-    space_info   space(const path& p, error_code& ec) noexcept;
-
-    file_status  status(const path& p);
-    file_status  status(const path& p, error_code& ec) noexcept;
-
-    bool status_known(file_status s) noexcept;
-
-    file_status  symlink_status(const path& p);
-    file_status  symlink_status(const path& p, error_code& ec) noexcept;
-
-    path temp_directory_path();
-    path temp_directory_path(error_code& ec);
-
-    path weakly_canonical(path const& p);
-    path weakly_canonical(path const& p, error_code& ec);
-
-
-} }  // namespaces std::filesystem
-
-*/
-
-#include <__config>
-#include <cstddef>
-#include <cstdlib>
-#include <chrono>
-#include <iterator>
-#include <iosfwd>
-#include <locale>
-#include <memory>
-#include <stack>
-#include <string>
-#include <system_error>
-#include <utility>
-#include <iomanip> // for quoted
-#include <string_view>
-#include <version>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-#ifndef _LIBCPP_CXX03_LANG
-
-_LIBCPP_BEGIN_NAMESPACE_FILESYSTEM
-
-typedef chrono::time_point<_FilesystemClock> file_time_type;
-
-struct _LIBCPP_TYPE_VIS space_info {
-  uintmax_t capacity;
-  uintmax_t free;
-  uintmax_t available;
-};
-
-enum class _LIBCPP_ENUM_VIS file_type : signed char {
-  none = 0,
-  not_found = -1,
-  regular = 1,
-  directory = 2,
-  symlink = 3,
-  block = 4,
-  character = 5,
-  fifo = 6,
-  socket = 7,
-  unknown = 8
-};
-
-enum class _LIBCPP_ENUM_VIS perms : unsigned {
-  none = 0,
-
-  owner_read = 0400,
-  owner_write = 0200,
-  owner_exec = 0100,
-  owner_all = 0700,
-
-  group_read = 040,
-  group_write = 020,
-  group_exec = 010,
-  group_all = 070,
-
-  others_read = 04,
-  others_write = 02,
-  others_exec = 01,
-  others_all = 07,
-
-  all = 0777,
-
-  set_uid = 04000,
-  set_gid = 02000,
-  sticky_bit = 01000,
-  mask = 07777,
-  unknown = 0xFFFF,
-};
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr perms operator&(perms _LHS, perms _RHS) {
-  return static_cast<perms>(static_cast<unsigned>(_LHS) &
-                            static_cast<unsigned>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr perms operator|(perms _LHS, perms _RHS) {
-  return static_cast<perms>(static_cast<unsigned>(_LHS) |
-                            static_cast<unsigned>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr perms operator^(perms _LHS, perms _RHS) {
-  return static_cast<perms>(static_cast<unsigned>(_LHS) ^
-                            static_cast<unsigned>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr perms operator~(perms _LHS) {
-  return static_cast<perms>(~static_cast<unsigned>(_LHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline perms& operator&=(perms& _LHS, perms _RHS) { return _LHS = _LHS & _RHS; }
-
-_LIBCPP_INLINE_VISIBILITY
-inline perms& operator|=(perms& _LHS, perms _RHS) { return _LHS = _LHS | _RHS; }
-
-_LIBCPP_INLINE_VISIBILITY
-inline perms& operator^=(perms& _LHS, perms _RHS) { return _LHS = _LHS ^ _RHS; }
-
-enum class _LIBCPP_ENUM_VIS perm_options : unsigned char {
-  replace = 1,
-  add = 2,
-  remove = 4,
-  nofollow = 8
-};
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr perm_options operator&(perm_options _LHS, perm_options _RHS) {
-  return static_cast<perm_options>(static_cast<unsigned>(_LHS) &
-                                   static_cast<unsigned>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr perm_options operator|(perm_options _LHS, perm_options _RHS) {
-  return static_cast<perm_options>(static_cast<unsigned>(_LHS) |
-                                   static_cast<unsigned>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr perm_options operator^(perm_options _LHS, perm_options _RHS) {
-  return static_cast<perm_options>(static_cast<unsigned>(_LHS) ^
-                                   static_cast<unsigned>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr perm_options operator~(perm_options _LHS) {
-  return static_cast<perm_options>(~static_cast<unsigned>(_LHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline perm_options& operator&=(perm_options& _LHS, perm_options _RHS) {
-  return _LHS = _LHS & _RHS;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline perm_options& operator|=(perm_options& _LHS, perm_options _RHS) {
-  return _LHS = _LHS | _RHS;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline perm_options& operator^=(perm_options& _LHS, perm_options _RHS) {
-  return _LHS = _LHS ^ _RHS;
-}
-
-enum class _LIBCPP_ENUM_VIS copy_options : unsigned short {
-  none = 0,
-  skip_existing = 1,
-  overwrite_existing = 2,
-  update_existing = 4,
-  recursive = 8,
-  copy_symlinks = 16,
-  skip_symlinks = 32,
-  directories_only = 64,
-  create_symlinks = 128,
-  create_hard_links = 256,
-  __in_recursive_copy = 512,
-};
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr copy_options operator&(copy_options _LHS, copy_options _RHS) {
-  return static_cast<copy_options>(static_cast<unsigned short>(_LHS) &
-                                   static_cast<unsigned short>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr copy_options operator|(copy_options _LHS, copy_options _RHS) {
-  return static_cast<copy_options>(static_cast<unsigned short>(_LHS) |
-                                   static_cast<unsigned short>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr copy_options operator^(copy_options _LHS, copy_options _RHS) {
-  return static_cast<copy_options>(static_cast<unsigned short>(_LHS) ^
-                                   static_cast<unsigned short>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr copy_options operator~(copy_options _LHS) {
-  return static_cast<copy_options>(~static_cast<unsigned short>(_LHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline copy_options& operator&=(copy_options& _LHS, copy_options _RHS) {
-  return _LHS = _LHS & _RHS;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline copy_options& operator|=(copy_options& _LHS, copy_options _RHS) {
-  return _LHS = _LHS | _RHS;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline copy_options& operator^=(copy_options& _LHS, copy_options _RHS) {
-  return _LHS = _LHS ^ _RHS;
-}
-
-enum class _LIBCPP_ENUM_VIS directory_options : unsigned char {
-  none = 0,
-  follow_directory_symlink = 1,
-  skip_permission_denied = 2
-};
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr directory_options operator&(directory_options _LHS,
-                                             directory_options _RHS) {
-  return static_cast<directory_options>(static_cast<unsigned char>(_LHS) &
-                                        static_cast<unsigned char>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr directory_options operator|(directory_options _LHS,
-                                             directory_options _RHS) {
-  return static_cast<directory_options>(static_cast<unsigned char>(_LHS) |
-                                        static_cast<unsigned char>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr directory_options operator^(directory_options _LHS,
-                                             directory_options _RHS) {
-  return static_cast<directory_options>(static_cast<unsigned char>(_LHS) ^
-                                        static_cast<unsigned char>(_RHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline constexpr directory_options operator~(directory_options _LHS) {
-  return static_cast<directory_options>(~static_cast<unsigned char>(_LHS));
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline directory_options& operator&=(directory_options& _LHS,
-                                     directory_options _RHS) {
-  return _LHS = _LHS & _RHS;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline directory_options& operator|=(directory_options& _LHS,
-                                     directory_options _RHS) {
-  return _LHS = _LHS | _RHS;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline directory_options& operator^=(directory_options& _LHS,
-                                     directory_options _RHS) {
-  return _LHS = _LHS ^ _RHS;
-}
-
-class _LIBCPP_TYPE_VIS file_status {
-public:
-  // constructors
-  _LIBCPP_INLINE_VISIBILITY
-  file_status() noexcept : file_status(file_type::none) {}
-  _LIBCPP_INLINE_VISIBILITY
-  explicit file_status(file_type __ft, perms __prms = perms::unknown) noexcept
-      : __ft_(__ft),
-        __prms_(__prms) {}
-
-  file_status(const file_status&) noexcept = default;
-  file_status(file_status&&) noexcept = default;
-
-  _LIBCPP_INLINE_VISIBILITY
-  ~file_status() {}
-
-  file_status& operator=(const file_status&) noexcept = default;
-  file_status& operator=(file_status&&) noexcept = default;
-
-  // observers
-  _LIBCPP_INLINE_VISIBILITY
-  file_type type() const noexcept { return __ft_; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  perms permissions() const noexcept { return __prms_; }
-
-  // modifiers
-  _LIBCPP_INLINE_VISIBILITY
-  void type(file_type __ft) noexcept { __ft_ = __ft; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void permissions(perms __p) noexcept { __prms_ = __p; }
-
-private:
-  file_type __ft_;
-  perms __prms_;
-};
-
-class _LIBCPP_TYPE_VIS directory_entry;
-
-template <class _Tp>
-struct __can_convert_char {
-  static const bool value = false;
-};
-template <class _Tp>
-struct __can_convert_char<const _Tp> : public __can_convert_char<_Tp> {};
-template <>
-struct __can_convert_char<char> {
-  static const bool value = true;
-  using __char_type = char;
-};
-template <>
-struct __can_convert_char<wchar_t> {
-  static const bool value = true;
-  using __char_type = wchar_t;
-};
-template <>
-struct __can_convert_char<char16_t> {
-  static const bool value = true;
-  using __char_type = char16_t;
-};
-template <>
-struct __can_convert_char<char32_t> {
-  static const bool value = true;
-  using __char_type = char32_t;
-};
-
-template <class _ECharT>
-typename enable_if<__can_convert_char<_ECharT>::value, bool>::type
-__is_separator(_ECharT __e) {
-  return __e == _ECharT('/');
-}
-
-struct _NullSentinal {};
-
-template <class _Tp>
-using _Void = void;
-
-template <class _Tp, class = void>
-struct __is_pathable_string : public false_type {};
-
-template <class _ECharT, class _Traits, class _Alloc>
-struct __is_pathable_string<
-    basic_string<_ECharT, _Traits, _Alloc>,
-    _Void<typename __can_convert_char<_ECharT>::__char_type> >
-    : public __can_convert_char<_ECharT> {
-  using _Str = basic_string<_ECharT, _Traits, _Alloc>;
-  using _Base = __can_convert_char<_ECharT>;
-  static _ECharT const* __range_begin(_Str const& __s) { return __s.data(); }
-  static _ECharT const* __range_end(_Str const& __s) {
-    return __s.data() + __s.length();
-  }
-  static _ECharT __first_or_null(_Str const& __s) {
-    return __s.empty() ? _ECharT{} : __s[0];
-  }
-};
-
-template <class _ECharT, class _Traits>
-struct __is_pathable_string<
-    basic_string_view<_ECharT, _Traits>,
-    _Void<typename __can_convert_char<_ECharT>::__char_type> >
-    : public __can_convert_char<_ECharT> {
-  using _Str = basic_string_view<_ECharT, _Traits>;
-  using _Base = __can_convert_char<_ECharT>;
-  static _ECharT const* __range_begin(_Str const& __s) { return __s.data(); }
-  static _ECharT const* __range_end(_Str const& __s) {
-    return __s.data() + __s.length();
-  }
-  static _ECharT __first_or_null(_Str const& __s) {
-    return __s.empty() ? _ECharT{} : __s[0];
-  }
-};
-
-template <class _Source, class _DS = typename decay<_Source>::type,
-          class _UnqualPtrType =
-              typename remove_const<typename remove_pointer<_DS>::type>::type,
-          bool _IsCharPtr = is_pointer<_DS>::value&&
-              __can_convert_char<_UnqualPtrType>::value>
-struct __is_pathable_char_array : false_type {};
-
-template <class _Source, class _ECharT, class _UPtr>
-struct __is_pathable_char_array<_Source, _ECharT*, _UPtr, true>
-    : __can_convert_char<typename remove_const<_ECharT>::type> {
-  using _Base = __can_convert_char<typename remove_const<_ECharT>::type>;
-
-  static _ECharT const* __range_begin(const _ECharT* __b) { return __b; }
-  static _ECharT const* __range_end(const _ECharT* __b) {
-    using _Iter = const _ECharT*;
-    const _ECharT __sentinal = _ECharT{};
-    _Iter __e = __b;
-    for (; *__e != __sentinal; ++__e)
-      ;
-    return __e;
-  }
-
-  static _ECharT __first_or_null(const _ECharT* __b) { return *__b; }
-};
-
-template <class _Iter, bool _IsIt = __is_input_iterator<_Iter>::value,
-          class = void>
-struct __is_pathable_iter : false_type {};
-
-template <class _Iter>
-struct __is_pathable_iter<
-    _Iter, true,
-    _Void<typename __can_convert_char<
-        typename iterator_traits<_Iter>::value_type>::__char_type> >
-    : __can_convert_char<typename iterator_traits<_Iter>::value_type> {
-  using _ECharT = typename iterator_traits<_Iter>::value_type;
-  using _Base = __can_convert_char<_ECharT>;
-
-  static _Iter __range_begin(_Iter __b) { return __b; }
-  static _NullSentinal __range_end(_Iter) { return _NullSentinal{}; }
-
-  static _ECharT __first_or_null(_Iter __b) { return *__b; }
-};
-
-template <class _Tp, bool _IsStringT = __is_pathable_string<_Tp>::value,
-          bool _IsCharIterT = __is_pathable_char_array<_Tp>::value,
-          bool _IsIterT = !_IsCharIterT && __is_pathable_iter<_Tp>::value>
-struct __is_pathable : false_type {
-  static_assert(!_IsStringT && !_IsCharIterT && !_IsIterT, "Must all be false");
-};
-
-template <class _Tp>
-struct __is_pathable<_Tp, true, false, false> : __is_pathable_string<_Tp> {};
-
-template <class _Tp>
-struct __is_pathable<_Tp, false, true, false> : __is_pathable_char_array<_Tp> {
-};
-
-template <class _Tp>
-struct __is_pathable<_Tp, false, false, true> : __is_pathable_iter<_Tp> {};
-
-template <class _ECharT>
-struct _PathCVT {
-  static_assert(__can_convert_char<_ECharT>::value,
-                "Char type not convertible");
-
-  typedef __narrow_to_utf8<sizeof(_ECharT) * __CHAR_BIT__> _Narrower;
-
-  static void __append_range(string& __dest, _ECharT const* __b,
-                             _ECharT const* __e) {
-    _Narrower()(back_inserter(__dest), __b, __e);
-  }
-
-  template <class _Iter>
-  static void __append_range(string& __dest, _Iter __b, _Iter __e) {
-    static_assert(!is_same<_Iter, _ECharT*>::value, "Call const overload");
-    if (__b == __e)
-      return;
-    basic_string<_ECharT> __tmp(__b, __e);
-    _Narrower()(back_inserter(__dest), __tmp.data(),
-                __tmp.data() + __tmp.length());
-  }
-
-  template <class _Iter>
-  static void __append_range(string& __dest, _Iter __b, _NullSentinal) {
-    static_assert(!is_same<_Iter, _ECharT*>::value, "Call const overload");
-    const _ECharT __sentinal = _ECharT{};
-    if (*__b == __sentinal)
-      return;
-    basic_string<_ECharT> __tmp;
-    for (; *__b != __sentinal; ++__b)
-      __tmp.push_back(*__b);
-    _Narrower()(back_inserter(__dest), __tmp.data(),
-                __tmp.data() + __tmp.length());
-  }
-
-  template <class _Source>
-  static void __append_source(string& __dest, _Source const& __s) {
-    using _Traits = __is_pathable<_Source>;
-    __append_range(__dest, _Traits::__range_begin(__s),
-                   _Traits::__range_end(__s));
-  }
-};
-
-template <>
-struct _PathCVT<char> {
-
-  template <class _Iter>
-  static typename enable_if<__is_exactly_input_iterator<_Iter>::value>::type
-  __append_range(string& __dest, _Iter __b, _Iter __e) {
-    for (; __b != __e; ++__b)
-      __dest.push_back(*__b);
-  }
-
-  template <class _Iter>
-  static typename enable_if<__is_forward_iterator<_Iter>::value>::type
-  __append_range(string& __dest, _Iter __b, _Iter __e) {
-    __dest.__append_forward_unsafe(__b, __e);
-  }
-
-  template <class _Iter>
-  static void __append_range(string& __dest, _Iter __b, _NullSentinal) {
-    const char __sentinal = char{};
-    for (; *__b != __sentinal; ++__b)
-      __dest.push_back(*__b);
-  }
-
-  template <class _Source>
-  static void __append_source(string& __dest, _Source const& __s) {
-    using _Traits = __is_pathable<_Source>;
-    __append_range(__dest, _Traits::__range_begin(__s),
-                   _Traits::__range_end(__s));
-  }
-};
-
-class _LIBCPP_TYPE_VIS path {
-  template <class _SourceOrIter, class _Tp = path&>
-  using _EnableIfPathable =
-      typename enable_if<__is_pathable<_SourceOrIter>::value, _Tp>::type;
-
-  template <class _Tp>
-  using _SourceChar = typename __is_pathable<_Tp>::__char_type;
-
-  template <class _Tp>
-  using _SourceCVT = _PathCVT<_SourceChar<_Tp> >;
-
-public:
-  typedef char value_type;
-  typedef basic_string<value_type> string_type;
-  typedef _VSTD::string_view __string_view;
-  static constexpr value_type preferred_separator = '/';
-
-  enum class _LIBCPP_ENUM_VIS format : unsigned char {
-    auto_format,
-    native_format,
-    generic_format
-  };
-
-  // constructors and destructor
-  _LIBCPP_INLINE_VISIBILITY path() noexcept {}
-  _LIBCPP_INLINE_VISIBILITY path(const path& __p) : __pn_(__p.__pn_) {}
-  _LIBCPP_INLINE_VISIBILITY path(path&& __p) noexcept
-      : __pn_(_VSTD::move(__p.__pn_)) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  path(string_type&& __s, format = format::auto_format) noexcept
-      : __pn_(_VSTD::move(__s)) {}
-
-  template <class _Source, class = _EnableIfPathable<_Source, void> >
-  path(const _Source& __src, format = format::auto_format) {
-    _SourceCVT<_Source>::__append_source(__pn_, __src);
-  }
-
-  template <class _InputIt>
-  path(_InputIt __first, _InputIt __last, format = format::auto_format) {
-    typedef typename iterator_traits<_InputIt>::value_type _ItVal;
-    _PathCVT<_ItVal>::__append_range(__pn_, __first, __last);
-  }
-
-  // TODO Implement locale conversions.
-  template <class _Source, class = _EnableIfPathable<_Source, void> >
-  path(const _Source& __src, const locale& __loc, format = format::auto_format);
-  template <class _InputIt>
-  path(_InputIt __first, _InputIt _last, const locale& __loc,
-       format = format::auto_format);
-
-  _LIBCPP_INLINE_VISIBILITY
-  ~path() = default;
-
-  // assignments
-  _LIBCPP_INLINE_VISIBILITY
-  path& operator=(const path& __p) {
-    __pn_ = __p.__pn_;
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  path& operator=(path&& __p) noexcept {
-    __pn_ = _VSTD::move(__p.__pn_);
-    return *this;
-  }
-
-  template <class = void>
-  _LIBCPP_INLINE_VISIBILITY path& operator=(string_type&& __s) noexcept {
-    __pn_ = _VSTD::move(__s);
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  path& assign(string_type&& __s) noexcept {
-    __pn_ = _VSTD::move(__s);
-    return *this;
-  }
-
-  template <class _Source>
-  _LIBCPP_INLINE_VISIBILITY _EnableIfPathable<_Source>
-  operator=(const _Source& __src) {
-    return this->assign(__src);
-  }
-
-  template <class _Source>
-  _EnableIfPathable<_Source> assign(const _Source& __src) {
-    __pn_.clear();
-    _SourceCVT<_Source>::__append_source(__pn_, __src);
-    return *this;
-  }
-
-  template <class _InputIt>
-  path& assign(_InputIt __first, _InputIt __last) {
-    typedef typename iterator_traits<_InputIt>::value_type _ItVal;
-    __pn_.clear();
-    _PathCVT<_ItVal>::__append_range(__pn_, __first, __last);
-    return *this;
-  }
-
-private:
-  template <class _ECharT>
-  static bool __source_is_absolute(_ECharT __first_or_null) {
-    return __is_separator(__first_or_null);
-  }
-
-public:
-  // appends
-  path& operator/=(const path& __p) {
-    if (__p.is_absolute()) {
-      __pn_ = __p.__pn_;
-      return *this;
-    }
-    if (has_filename())
-      __pn_ += preferred_separator;
-    __pn_ += __p.native();
-    return *this;
-  }
-
-  // FIXME: Use _LIBCPP_DIAGNOSE_WARNING to produce a diagnostic when __src
-  // is known at compile time to be "/' since the user almost certainly intended
-  // to append a separator instead of overwriting the path with "/"
-  template <class _Source>
-  _LIBCPP_INLINE_VISIBILITY _EnableIfPathable<_Source>
-  operator/=(const _Source& __src) {
-    return this->append(__src);
-  }
-
-  template <class _Source>
-  _EnableIfPathable<_Source> append(const _Source& __src) {
-    using _Traits = __is_pathable<_Source>;
-    using _CVT = _PathCVT<_SourceChar<_Source> >;
-    if (__source_is_absolute(_Traits::__first_or_null(__src)))
-      __pn_.clear();
-    else if (has_filename())
-      __pn_ += preferred_separator;
-    _CVT::__append_source(__pn_, __src);
-    return *this;
-  }
-
-  template <class _InputIt>
-  path& append(_InputIt __first, _InputIt __last) {
-    typedef typename iterator_traits<_InputIt>::value_type _ItVal;
-    static_assert(__can_convert_char<_ItVal>::value, "Must convertible");
-    using _CVT = _PathCVT<_ItVal>;
-    if (__first != __last && __source_is_absolute(*__first))
-      __pn_.clear();
-    else if (has_filename())
-      __pn_ += preferred_separator;
-    _CVT::__append_range(__pn_, __first, __last);
-    return *this;
-  }
-
-  // concatenation
-  _LIBCPP_INLINE_VISIBILITY
-  path& operator+=(const path& __x) {
-    __pn_ += __x.__pn_;
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  path& operator+=(const string_type& __x) {
-    __pn_ += __x;
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  path& operator+=(__string_view __x) {
-    __pn_ += __x;
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  path& operator+=(const value_type* __x) {
-    __pn_ += __x;
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  path& operator+=(value_type __x) {
-    __pn_ += __x;
-    return *this;
-  }
-
-  template <class _ECharT>
-  typename enable_if<__can_convert_char<_ECharT>::value, path&>::type
-  operator+=(_ECharT __x) {
-    basic_string<_ECharT> __tmp;
-    __tmp += __x;
-    _PathCVT<_ECharT>::__append_source(__pn_, __tmp);
-    return *this;
-  }
-
-  template <class _Source>
-  _EnableIfPathable<_Source> operator+=(const _Source& __x) {
-    return this->concat(__x);
-  }
-
-  template <class _Source>
-  _EnableIfPathable<_Source> concat(const _Source& __x) {
-    _SourceCVT<_Source>::__append_source(__pn_, __x);
-    return *this;
-  }
-
-  template <class _InputIt>
-  path& concat(_InputIt __first, _InputIt __last) {
-    typedef typename iterator_traits<_InputIt>::value_type _ItVal;
-    _PathCVT<_ItVal>::__append_range(__pn_, __first, __last);
-    return *this;
-  }
-
-  // modifiers
-  _LIBCPP_INLINE_VISIBILITY
-  void clear() noexcept { __pn_.clear(); }
-
-  path& make_preferred() { return *this; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  path& remove_filename() {
-    auto __fname = __filename();
-    if (!__fname.empty())
-      __pn_.erase(__fname.data() - __pn_.data());
-    return *this;
-  }
-
-  path& replace_filename(const path& __replacement) {
-    remove_filename();
-    return (*this /= __replacement);
-  }
-
-  path& replace_extension(const path& __replacement = path());
-
-  _LIBCPP_INLINE_VISIBILITY
-  void swap(path& __rhs) noexcept { __pn_.swap(__rhs.__pn_); }
-
-  // private helper to allow reserving memory in the path
-  _LIBCPP_INLINE_VISIBILITY
-  void __reserve(size_t __s) { __pn_.reserve(__s); }
-
-  // native format observers
-  _LIBCPP_INLINE_VISIBILITY
-  const string_type& native() const noexcept { return __pn_; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  const value_type* c_str() const noexcept { return __pn_.c_str(); }
-
-  _LIBCPP_INLINE_VISIBILITY operator string_type() const { return __pn_; }
-
-  template <class _ECharT, class _Traits = char_traits<_ECharT>,
-            class _Allocator = allocator<_ECharT> >
-  basic_string<_ECharT, _Traits, _Allocator>
-  string(const _Allocator& __a = _Allocator()) const {
-    using _CVT = __widen_from_utf8<sizeof(_ECharT) * __CHAR_BIT__>;
-    using _Str = basic_string<_ECharT, _Traits, _Allocator>;
-    _Str __s(__a);
-    __s.reserve(__pn_.size());
-    _CVT()(back_inserter(__s), __pn_.data(), __pn_.data() + __pn_.size());
-    return __s;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY std::string string() const { return __pn_; }
-  _LIBCPP_INLINE_VISIBILITY std::wstring wstring() const {
-    return string<wchar_t>();
-  }
-  _LIBCPP_INLINE_VISIBILITY std::string u8string() const { return __pn_; }
-  _LIBCPP_INLINE_VISIBILITY std::u16string u16string() const {
-    return string<char16_t>();
-  }
-  _LIBCPP_INLINE_VISIBILITY std::u32string u32string() const {
-    return string<char32_t>();
-  }
-
-  // generic format observers
-  template <class _ECharT, class _Traits = char_traits<_ECharT>,
-            class _Allocator = allocator<_ECharT> >
-  basic_string<_ECharT, _Traits, _Allocator>
-  generic_string(const _Allocator& __a = _Allocator()) const {
-    return string<_ECharT, _Traits, _Allocator>(__a);
-  }
-
-  std::string generic_string() const { return __pn_; }
-  std::wstring generic_wstring() const { return string<wchar_t>(); }
-  std::string generic_u8string() const { return __pn_; }
-  std::u16string generic_u16string() const { return string<char16_t>(); }
-  std::u32string generic_u32string() const { return string<char32_t>(); }
-
-private:
-  int __compare(__string_view) const;
-  __string_view __root_name() const;
-  __string_view __root_directory() const;
-  __string_view __root_path_raw() const;
-  __string_view __relative_path() const;
-  __string_view __parent_path() const;
-  __string_view __filename() const;
-  __string_view __stem() const;
-  __string_view __extension() const;
-
-public:
-  // compare
-  _LIBCPP_INLINE_VISIBILITY int compare(const path& __p) const noexcept {
-    return __compare(__p.__pn_);
-  }
-  _LIBCPP_INLINE_VISIBILITY int compare(const string_type& __s) const {
-    return __compare(__s);
-  }
-  _LIBCPP_INLINE_VISIBILITY int compare(__string_view __s) const {
-    return __compare(__s);
-  }
-  _LIBCPP_INLINE_VISIBILITY int compare(const value_type* __s) const {
-    return __compare(__s);
-  }
-
-  // decomposition
-  _LIBCPP_INLINE_VISIBILITY path root_name() const {
-    return string_type(__root_name());
-  }
-  _LIBCPP_INLINE_VISIBILITY path root_directory() const {
-    return string_type(__root_directory());
-  }
-  _LIBCPP_INLINE_VISIBILITY path root_path() const {
-    return root_name().append(string_type(__root_directory()));
-  }
-  _LIBCPP_INLINE_VISIBILITY path relative_path() const {
-    return string_type(__relative_path());
-  }
-  _LIBCPP_INLINE_VISIBILITY path parent_path() const {
-    return string_type(__parent_path());
-  }
-  _LIBCPP_INLINE_VISIBILITY path filename() const {
-    return string_type(__filename());
-  }
-  _LIBCPP_INLINE_VISIBILITY path stem() const { return string_type(__stem()); }
-  _LIBCPP_INLINE_VISIBILITY path extension() const {
-    return string_type(__extension());
-  }
-
-  // query
-  _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY bool
-  empty() const noexcept {
-    return __pn_.empty();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY bool has_root_name() const {
-    return !__root_name().empty();
-  }
-  _LIBCPP_INLINE_VISIBILITY bool has_root_directory() const {
-    return !__root_directory().empty();
-  }
-  _LIBCPP_INLINE_VISIBILITY bool has_root_path() const {
-    return !__root_path_raw().empty();
-  }
-  _LIBCPP_INLINE_VISIBILITY bool has_relative_path() const {
-    return !__relative_path().empty();
-  }
-  _LIBCPP_INLINE_VISIBILITY bool has_parent_path() const {
-    return !__parent_path().empty();
-  }
-  _LIBCPP_INLINE_VISIBILITY bool has_filename() const {
-    return !__filename().empty();
-  }
-  _LIBCPP_INLINE_VISIBILITY bool has_stem() const { return !__stem().empty(); }
-  _LIBCPP_INLINE_VISIBILITY bool has_extension() const {
-    return !__extension().empty();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY bool is_absolute() const {
-    return has_root_directory();
-  }
-  _LIBCPP_INLINE_VISIBILITY bool is_relative() const { return !is_absolute(); }
-
-  // relative paths
-  path lexically_normal() const;
-  path lexically_relative(const path& __base) const;
-
-  _LIBCPP_INLINE_VISIBILITY path lexically_proximate(const path& __base) const {
-    path __result = this->lexically_relative(__base);
-    if (__result.native().empty())
-      return *this;
-    return __result;
-  }
-
-  // iterators
-  class _LIBCPP_TYPE_VIS iterator;
-  typedef iterator const_iterator;
-
-  iterator begin() const;
-  iterator end() const;
-
-  template <class _CharT, class _Traits>
-  _LIBCPP_INLINE_VISIBILITY friend
-      typename enable_if<is_same<_CharT, char>::value &&
-                             is_same<_Traits, char_traits<char> >::value,
-                         basic_ostream<_CharT, _Traits>&>::type
-      operator<<(basic_ostream<_CharT, _Traits>& __os, const path& __p) {
-    __os << std::__quoted(__p.native());
-    return __os;
-  }
-
-  template <class _CharT, class _Traits>
-  _LIBCPP_INLINE_VISIBILITY friend
-      typename enable_if<!is_same<_CharT, char>::value ||
-                             !is_same<_Traits, char_traits<char> >::value,
-                         basic_ostream<_CharT, _Traits>&>::type
-      operator<<(basic_ostream<_CharT, _Traits>& __os, const path& __p) {
-    __os << std::__quoted(__p.string<_CharT, _Traits>());
-    return __os;
-  }
-
-  template <class _CharT, class _Traits>
-  _LIBCPP_INLINE_VISIBILITY friend basic_istream<_CharT, _Traits>&
-  operator>>(basic_istream<_CharT, _Traits>& __is, path& __p) {
-    basic_string<_CharT, _Traits> __tmp;
-    __is >> __quoted(__tmp);
-    __p = __tmp;
-    return __is;
-  }
-
-  friend _LIBCPP_INLINE_VISIBILITY bool operator==(const path& __lhs, const path& __rhs) noexcept {
-    return __lhs.compare(__rhs) == 0;
-  }
-  friend _LIBCPP_INLINE_VISIBILITY bool operator!=(const path& __lhs, const path& __rhs) noexcept {
-    return __lhs.compare(__rhs) != 0;
-  }
-  friend _LIBCPP_INLINE_VISIBILITY bool operator<(const path& __lhs, const path& __rhs) noexcept {
-    return __lhs.compare(__rhs) < 0;
-  }
-  friend _LIBCPP_INLINE_VISIBILITY bool operator<=(const path& __lhs, const path& __rhs) noexcept {
-    return __lhs.compare(__rhs) <= 0;
-  }
-  friend _LIBCPP_INLINE_VISIBILITY bool operator>(const path& __lhs, const path& __rhs) noexcept {
-    return __lhs.compare(__rhs) > 0;
-  }
-  friend _LIBCPP_INLINE_VISIBILITY bool operator>=(const path& __lhs, const path& __rhs) noexcept {
-    return __lhs.compare(__rhs) >= 0;
-  }
-
-  friend _LIBCPP_INLINE_VISIBILITY path operator/(const path& __lhs,
-                                                  const path& __rhs) {
-    path __result(__lhs);
-    __result /= __rhs;
-    return __result;
-  }
-private:
-  inline _LIBCPP_INLINE_VISIBILITY path&
-  __assign_view(__string_view const& __s) noexcept {
-    __pn_ = string_type(__s);
-    return *this;
-  }
-  string_type __pn_;
-};
-
-inline _LIBCPP_INLINE_VISIBILITY void swap(path& __lhs, path& __rhs) noexcept {
-  __lhs.swap(__rhs);
-}
-
-_LIBCPP_FUNC_VIS
-size_t hash_value(const path& __p) noexcept;
-
-template <class _Source>
-_LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_pathable<_Source>::value, path>::type
-    u8path(const _Source& __s) {
-  static_assert(
-      is_same<typename __is_pathable<_Source>::__char_type, char>::value,
-      "u8path(Source const&) requires Source have a character type of type "
-      "'char'");
-  return path(__s);
-}
-
-template <class _InputIt>
-_LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_pathable<_InputIt>::value, path>::type
-    u8path(_InputIt __f, _InputIt __l) {
-  static_assert(
-      is_same<typename __is_pathable<_InputIt>::__char_type, char>::value,
-      "u8path(Iter, Iter) requires Iter have a value_type of type 'char'");
-  return path(__f, __l);
-}
-
-class _LIBCPP_TYPE_VIS path::iterator {
-public:
-  enum _ParserState : unsigned char {
-    _Singular,
-    _BeforeBegin,
-    _InRootName,
-    _InRootDir,
-    _InFilenames,
-    _InTrailingSep,
-    _AtEnd
-  };
-
-public:
-  typedef bidirectional_iterator_tag iterator_category;
-
-  typedef path value_type;
-  typedef std::ptrdiff_t difference_type;
-  typedef const path* pointer;
-  typedef const path& reference;
-
-  typedef void
-      __stashing_iterator_tag; // See reverse_iterator and __is_stashing_iterator
-
-public:
-  _LIBCPP_INLINE_VISIBILITY
-  iterator()
-      : __stashed_elem_(), __path_ptr_(nullptr), __entry_(),
-        __state_(_Singular) {}
-
-  iterator(const iterator&) = default;
-  ~iterator() = default;
-
-  iterator& operator=(const iterator&) = default;
-
-  _LIBCPP_INLINE_VISIBILITY
-  reference operator*() const { return __stashed_elem_; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  pointer operator->() const { return &__stashed_elem_; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  iterator& operator++() {
-    _LIBCPP_ASSERT(__state_ != _Singular,
-                   "attempting to increment a singular iterator");
-    _LIBCPP_ASSERT(__state_ != _AtEnd,
-                   "attempting to increment the end iterator");
-    return __increment();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  iterator operator++(int) {
-    iterator __it(*this);
-    this->operator++();
-    return __it;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  iterator& operator--() {
-    _LIBCPP_ASSERT(__state_ != _Singular,
-                   "attempting to decrement a singular iterator");
-    _LIBCPP_ASSERT(__entry_.data() != __path_ptr_->native().data(),
-                   "attempting to decrement the begin iterator");
-    return __decrement();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  iterator operator--(int) {
-    iterator __it(*this);
-    this->operator--();
-    return __it;
-  }
-
-private:
-  friend class path;
-
-  inline _LIBCPP_INLINE_VISIBILITY friend bool operator==(const iterator&,
-                                                          const iterator&);
-
-  iterator& __increment();
-  iterator& __decrement();
-
-  path __stashed_elem_;
-  const path* __path_ptr_;
-  path::__string_view __entry_;
-  _ParserState __state_;
-};
-
-inline _LIBCPP_INLINE_VISIBILITY bool operator==(const path::iterator& __lhs,
-                                                 const path::iterator& __rhs) {
-  return __lhs.__path_ptr_ == __rhs.__path_ptr_ &&
-         __lhs.__entry_.data() == __rhs.__entry_.data();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool operator!=(const path::iterator& __lhs,
-                                                 const path::iterator& __rhs) {
-  return !(__lhs == __rhs);
-}
-
-class _LIBCPP_EXCEPTION_ABI filesystem_error : public system_error {
-public:
-  _LIBCPP_INLINE_VISIBILITY
-  filesystem_error(const string& __what, error_code __ec)
-      : system_error(__ec, __what),
-        __storage_(make_shared<_Storage>(path(), path())) {
-    __create_what(0);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  filesystem_error(const string& __what, const path& __p1, error_code __ec)
-      : system_error(__ec, __what),
-        __storage_(make_shared<_Storage>(__p1, path())) {
-    __create_what(1);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  filesystem_error(const string& __what, const path& __p1, const path& __p2,
-                   error_code __ec)
-      : system_error(__ec, __what),
-        __storage_(make_shared<_Storage>(__p1, __p2)) {
-    __create_what(2);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  const path& path1() const noexcept { return __storage_->__p1_; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  const path& path2() const noexcept { return __storage_->__p2_; }
-
-  ~filesystem_error() override; // key function
-
-  _LIBCPP_INLINE_VISIBILITY
-  const char* what() const noexcept override {
-    return __storage_->__what_.c_str();
-  }
-
-  _LIBCPP_FUNC_VIS
-  void __create_what(int __num_paths);
-
-private:
-  struct _Storage {
-    _LIBCPP_INLINE_VISIBILITY
-    _Storage(const path& __p1, const path& __p2) : __p1_(__p1), __p2_(__p2) {}
-
-    path __p1_;
-    path __p2_;
-    string __what_;
-  };
-  shared_ptr<_Storage> __storage_;
-};
-
-template <class... _Args>
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    void
-    __throw_filesystem_error(_Args&&... __args) {
-  throw filesystem_error(std::forward<_Args>(__args)...);
-}
-#else
-    void
-    __throw_filesystem_error(_Args&&...) {
-  _VSTD::abort();
-}
-#endif
-
-// operational functions
-
-_LIBCPP_FUNC_VIS
-path __absolute(const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-path __canonical(const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __copy(const path& __from, const path& __to, copy_options __opt,
-            error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-bool __copy_file(const path& __from, const path& __to, copy_options __opt,
-                 error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __copy_symlink(const path& __existing_symlink, const path& __new_symlink,
-                    error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-bool __create_directories(const path& p, error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-bool __create_directory(const path& p, error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-bool __create_directory(const path& p, const path& attributes,
-                        error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __create_directory_symlink(const path& __to, const path& __new_symlink,
-                                error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __create_hard_link(const path& __to, const path& __new_hard_link,
-                        error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __create_symlink(const path& __to, const path& __new_symlink,
-                      error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-path __current_path(error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __current_path(const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-bool __equivalent(const path&, const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-uintmax_t __file_size(const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-uintmax_t __hard_link_count(const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-bool __fs_is_empty(const path& p, error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-file_time_type __last_write_time(const path& p, error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __last_write_time(const path& p, file_time_type new_time,
-                       error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __permissions(const path&, perms, perm_options, error_code* = nullptr);
-_LIBCPP_FUNC_VIS
-path __read_symlink(const path& p, error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-bool __remove(const path& p, error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-uintmax_t __remove_all(const path& p, error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __rename(const path& from, const path& to, error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-void __resize_file(const path& p, uintmax_t size, error_code* ec = nullptr);
-_LIBCPP_FUNC_VIS
-space_info __space(const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-file_status __status(const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-file_status __symlink_status(const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-path __system_complete(const path&, error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-path __temp_directory_path(error_code* __ec = nullptr);
-_LIBCPP_FUNC_VIS
-path __weakly_canonical(path const& __p, error_code* __ec = nullptr);
-
-inline _LIBCPP_INLINE_VISIBILITY path current_path() {
-  return __current_path();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path current_path(error_code& __ec) {
-  return __current_path(&__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void current_path(const path& __p) {
-  __current_path(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void current_path(const path& __p,
-                                                   error_code& __ec) noexcept {
-  __current_path(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path absolute(const path& __p) {
-  return __absolute(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path absolute(const path& __p,
-                                               error_code& __ec) {
-  return __absolute(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path canonical(const path& __p) {
-  return __canonical(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path canonical(const path& __p,
-                                                error_code& __ec) {
-  return __canonical(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void copy(const path& __from,
-                                           const path& __to) {
-  __copy(__from, __to, copy_options::none);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void copy(const path& __from, const path& __to,
-                                           error_code& __ec) {
-  __copy(__from, __to, copy_options::none, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void copy(const path& __from, const path& __to,
-                                           copy_options __opt) {
-  __copy(__from, __to, __opt);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void copy(const path& __from, const path& __to,
-                                           copy_options __opt,
-                                           error_code& __ec) {
-  __copy(__from, __to, __opt, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool copy_file(const path& __from,
-                                                const path& __to) {
-  return __copy_file(__from, __to, copy_options::none);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-copy_file(const path& __from, const path& __to, error_code& __ec) {
-  return __copy_file(__from, __to, copy_options::none, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-copy_file(const path& __from, const path& __to, copy_options __opt) {
-  return __copy_file(__from, __to, __opt);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool copy_file(const path& __from,
-                                                const path& __to,
-                                                copy_options __opt,
-                                                error_code& __ec) {
-  return __copy_file(__from, __to, __opt, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void copy_symlink(const path& __existing,
-                                                   const path& __new) {
-  __copy_symlink(__existing, __new);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void
-copy_symlink(const path& __ext, const path& __new, error_code& __ec) noexcept {
-  __copy_symlink(__ext, __new, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool create_directories(const path& __p) {
-  return __create_directories(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool create_directories(const path& __p,
-                                                         error_code& __ec) {
-  return __create_directories(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool create_directory(const path& __p) {
-  return __create_directory(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-create_directory(const path& __p, error_code& __ec) noexcept {
-  return __create_directory(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool create_directory(const path& __p,
-                                                       const path& __attrs) {
-  return __create_directory(__p, __attrs);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-create_directory(const path& __p, const path& __attrs,
-                 error_code& __ec) noexcept {
-  return __create_directory(__p, __attrs, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void
-create_directory_symlink(const path& __to, const path& __new) {
-  __create_directory_symlink(__to, __new);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void
-create_directory_symlink(const path& __to, const path& __new,
-                         error_code& __ec) noexcept {
-  __create_directory_symlink(__to, __new, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void create_hard_link(const path& __to,
-                                                       const path& __new) {
-  __create_hard_link(__to, __new);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void
-create_hard_link(const path& __to, const path& __new,
-                 error_code& __ec) noexcept {
-  __create_hard_link(__to, __new, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void create_symlink(const path& __to,
-                                                     const path& __new) {
-  __create_symlink(__to, __new);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void
-create_symlink(const path& __to, const path& __new, error_code& __ec) noexcept {
-  return __create_symlink(__to, __new, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool status_known(file_status __s) noexcept {
-  return __s.type() != file_type::none;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool exists(file_status __s) noexcept {
-  return status_known(__s) && __s.type() != file_type::not_found;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool exists(const path& __p) {
-  return exists(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool exists(const path& __p,
-                                             error_code& __ec) noexcept {
-  auto __s = __status(__p, &__ec);
-  if (status_known(__s))
-    __ec.clear();
-  return exists(__s);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool equivalent(const path& __p1,
-                                                 const path& __p2) {
-  return __equivalent(__p1, __p2);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-equivalent(const path& __p1, const path& __p2, error_code& __ec) noexcept {
-  return __equivalent(__p1, __p2, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY uintmax_t file_size(const path& __p) {
-  return __file_size(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY uintmax_t
-file_size(const path& __p, error_code& __ec) noexcept {
-  return __file_size(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY uintmax_t hard_link_count(const path& __p) {
-  return __hard_link_count(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY uintmax_t
-hard_link_count(const path& __p, error_code& __ec) noexcept {
-  return __hard_link_count(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_block_file(file_status __s) noexcept {
-  return __s.type() == file_type::block;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_block_file(const path& __p) {
-  return is_block_file(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_block_file(const path& __p,
-                                                    error_code& __ec) noexcept {
-  return is_block_file(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-is_character_file(file_status __s) noexcept {
-  return __s.type() == file_type::character;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_character_file(const path& __p) {
-  return is_character_file(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-is_character_file(const path& __p, error_code& __ec) noexcept {
-  return is_character_file(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_directory(file_status __s) noexcept {
-  return __s.type() == file_type::directory;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_directory(const path& __p) {
-  return is_directory(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_directory(const path& __p,
-                                                   error_code& __ec) noexcept {
-  return is_directory(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_empty(const path& __p) {
-  return __fs_is_empty(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_empty(const path& __p,
-                                               error_code& __ec) {
-  return __fs_is_empty(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_fifo(file_status __s) noexcept {
-  return __s.type() == file_type::fifo;
-}
-inline _LIBCPP_INLINE_VISIBILITY bool is_fifo(const path& __p) {
-  return is_fifo(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_fifo(const path& __p,
-                                              error_code& __ec) noexcept {
-  return is_fifo(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-is_regular_file(file_status __s) noexcept {
-  return __s.type() == file_type::regular;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_regular_file(const path& __p) {
-  return is_regular_file(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-is_regular_file(const path& __p, error_code& __ec) noexcept {
-  return is_regular_file(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_socket(file_status __s) noexcept {
-  return __s.type() == file_type::socket;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_socket(const path& __p) {
-  return is_socket(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_socket(const path& __p,
-                                                error_code& __ec) noexcept {
-  return is_socket(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_symlink(file_status __s) noexcept {
-  return __s.type() == file_type::symlink;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_symlink(const path& __p) {
-  return is_symlink(__symlink_status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_symlink(const path& __p,
-                                                 error_code& __ec) noexcept {
-  return is_symlink(__symlink_status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_other(file_status __s) noexcept {
-  return exists(__s) && !is_regular_file(__s) && !is_directory(__s) &&
-         !is_symlink(__s);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_other(const path& __p) {
-  return is_other(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool is_other(const path& __p,
-                                               error_code& __ec) noexcept {
-  return is_other(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY file_time_type
-last_write_time(const path& __p) {
-  return __last_write_time(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY file_time_type
-last_write_time(const path& __p, error_code& __ec) noexcept {
-  return __last_write_time(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void last_write_time(const path& __p,
-                                                      file_time_type __t) {
-  __last_write_time(__p, __t);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void
-last_write_time(const path& __p, file_time_type __t,
-                error_code& __ec) noexcept {
-  __last_write_time(__p, __t, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void
-permissions(const path& __p, perms __prms,
-            perm_options __opts = perm_options::replace) {
-  __permissions(__p, __prms, __opts);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void permissions(const path& __p, perms __prms,
-                                                  error_code& __ec) noexcept {
-  __permissions(__p, __prms, perm_options::replace, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void permissions(const path& __p, perms __prms,
-                                                  perm_options __opts,
-                                                  error_code& __ec) {
-  __permissions(__p, __prms, __opts, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path proximate(const path& __p,
-                                                const path& __base,
-                                                error_code& __ec) {
-  path __tmp = __weakly_canonical(__p, &__ec);
-  if (__ec)
-    return {};
-  path __tmp_base = __weakly_canonical(__base, &__ec);
-  if (__ec)
-    return {};
-  return __tmp.lexically_proximate(__tmp_base);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path proximate(const path& __p,
-                                                error_code& __ec) {
-  return proximate(__p, current_path(), __ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path
-proximate(const path& __p, const path& __base = current_path()) {
-  return __weakly_canonical(__p).lexically_proximate(
-      __weakly_canonical(__base));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path read_symlink(const path& __p) {
-  return __read_symlink(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path read_symlink(const path& __p,
-                                                   error_code& __ec) {
-  return __read_symlink(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path relative(const path& __p,
-                                               const path& __base,
-                                               error_code& __ec) {
-  path __tmp = __weakly_canonical(__p, &__ec);
-  if (__ec)
-    return path();
-  path __tmpbase = __weakly_canonical(__base, &__ec);
-  if (__ec)
-    return path();
-  return __tmp.lexically_relative(__tmpbase);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path relative(const path& __p,
-                                               error_code& __ec) {
-  return relative(__p, current_path(), __ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path
-relative(const path& __p, const path& __base = current_path()) {
-  return __weakly_canonical(__p).lexically_relative(__weakly_canonical(__base));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool remove(const path& __p) {
-  return __remove(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool remove(const path& __p,
-                                             error_code& __ec) noexcept {
-  return __remove(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY uintmax_t remove_all(const path& __p) {
-  return __remove_all(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY uintmax_t remove_all(const path& __p,
-                                                      error_code& __ec) {
-  return __remove_all(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void rename(const path& __from,
-                                             const path& __to) {
-  return __rename(__from, __to);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void
-rename(const path& __from, const path& __to, error_code& __ec) noexcept {
-  return __rename(__from, __to, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void resize_file(const path& __p,
-                                                  uintmax_t __ns) {
-  return __resize_file(__p, __ns);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void
-resize_file(const path& __p, uintmax_t __ns, error_code& __ec) noexcept {
-  return __resize_file(__p, __ns, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY space_info space(const path& __p) {
-  return __space(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY space_info space(const path& __p,
-                                                  error_code& __ec) noexcept {
-  return __space(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY file_status status(const path& __p) {
-  return __status(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY file_status status(const path& __p,
-                                                    error_code& __ec) noexcept {
-  return __status(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY file_status symlink_status(const path& __p) {
-  return __symlink_status(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY file_status
-symlink_status(const path& __p, error_code& __ec) noexcept {
-  return __symlink_status(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path temp_directory_path() {
-  return __temp_directory_path();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path temp_directory_path(error_code& __ec) {
-  return __temp_directory_path(&__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path weakly_canonical(path const& __p) {
-  return __weakly_canonical(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY path weakly_canonical(path const& __p,
-                                                       error_code& __ec) {
-  return __weakly_canonical(__p, &__ec);
-}
-
-class directory_iterator;
-class recursive_directory_iterator;
-class __dir_stream;
-
-class directory_entry {
-  typedef _VSTD_FS::path _Path;
-
-public:
-  // constructors and destructors
-  directory_entry() noexcept = default;
-  directory_entry(directory_entry const&) = default;
-  directory_entry(directory_entry&&) noexcept = default;
-
-  _LIBCPP_INLINE_VISIBILITY
-  explicit directory_entry(_Path const& __p) : __p_(__p) {
-    error_code __ec;
-    __refresh(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  directory_entry(_Path const& __p, error_code& __ec) : __p_(__p) {
-    __refresh(&__ec);
-  }
-
-  ~directory_entry() {}
-
-  directory_entry& operator=(directory_entry const&) = default;
-  directory_entry& operator=(directory_entry&&) noexcept = default;
-
-  _LIBCPP_INLINE_VISIBILITY
-  void assign(_Path const& __p) {
-    __p_ = __p;
-    error_code __ec;
-    __refresh(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void assign(_Path const& __p, error_code& __ec) {
-    __p_ = __p;
-    __refresh(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void replace_filename(_Path const& __p) {
-    __p_.replace_filename(__p);
-    error_code __ec;
-    __refresh(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void replace_filename(_Path const& __p, error_code& __ec) {
-    __p_ = __p_.parent_path() / __p;
-    __refresh(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void refresh() { __refresh(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void refresh(error_code& __ec) noexcept { __refresh(&__ec); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  _Path const& path() const noexcept { return __p_; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  operator const _Path&() const noexcept { return __p_; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool exists() const { return _VSTD_FS::exists(file_status{__get_ft()}); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool exists(error_code& __ec) const noexcept {
-    return _VSTD_FS::exists(file_status{__get_ft(&__ec)});
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_block_file() const { return __get_ft() == file_type::block; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_block_file(error_code& __ec) const noexcept {
-    return __get_ft(&__ec) == file_type::block;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_character_file() const { return __get_ft() == file_type::character; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_character_file(error_code& __ec) const noexcept {
-    return __get_ft(&__ec) == file_type::character;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_directory() const { return __get_ft() == file_type::directory; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_directory(error_code& __ec) const noexcept {
-    return __get_ft(&__ec) == file_type::directory;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_fifo() const { return __get_ft() == file_type::fifo; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_fifo(error_code& __ec) const noexcept {
-    return __get_ft(&__ec) == file_type::fifo;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_other() const { return _VSTD_FS::is_other(file_status{__get_ft()}); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_other(error_code& __ec) const noexcept {
-    return _VSTD_FS::is_other(file_status{__get_ft(&__ec)});
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_regular_file() const { return __get_ft() == file_type::regular; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_regular_file(error_code& __ec) const noexcept {
-    return __get_ft(&__ec) == file_type::regular;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_socket() const { return __get_ft() == file_type::socket; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_socket(error_code& __ec) const noexcept {
-    return __get_ft(&__ec) == file_type::socket;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_symlink() const { return __get_sym_ft() == file_type::symlink; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool is_symlink(error_code& __ec) const noexcept {
-    return __get_sym_ft(&__ec) == file_type::symlink;
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  uintmax_t file_size() const { return __get_size(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  uintmax_t file_size(error_code& __ec) const noexcept {
-    return __get_size(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  uintmax_t hard_link_count() const { return __get_nlink(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  uintmax_t hard_link_count(error_code& __ec) const noexcept {
-    return __get_nlink(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_time_type last_write_time() const { return __get_write_time(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_time_type last_write_time(error_code& __ec) const noexcept {
-    return __get_write_time(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_status status() const { return __get_status(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_status status(error_code& __ec) const noexcept {
-    return __get_status(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_status symlink_status() const { return __get_symlink_status(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_status symlink_status(error_code& __ec) const noexcept {
-    return __get_symlink_status(&__ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool operator<(directory_entry const& __rhs) const noexcept {
-    return __p_ < __rhs.__p_;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool operator==(directory_entry const& __rhs) const noexcept {
-    return __p_ == __rhs.__p_;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool operator!=(directory_entry const& __rhs) const noexcept {
-    return __p_ != __rhs.__p_;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool operator<=(directory_entry const& __rhs) const noexcept {
-    return __p_ <= __rhs.__p_;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool operator>(directory_entry const& __rhs) const noexcept {
-    return __p_ > __rhs.__p_;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool operator>=(directory_entry const& __rhs) const noexcept {
-    return __p_ >= __rhs.__p_;
-  }
-
-private:
-  friend class directory_iterator;
-  friend class recursive_directory_iterator;
-  friend class __dir_stream;
-
-  enum _CacheType : unsigned char {
-    _Empty,
-    _IterSymlink,
-    _IterNonSymlink,
-    _RefreshSymlink,
-    _RefreshSymlinkUnresolved,
-    _RefreshNonSymlink
-  };
-
-  struct __cached_data {
-    uintmax_t __size_;
-    uintmax_t __nlink_;
-    file_time_type __write_time_;
-    perms __sym_perms_;
-    perms __non_sym_perms_;
-    file_type __type_;
-    _CacheType __cache_type_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __cached_data() noexcept { __reset(); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __reset() {
-      __cache_type_ = _Empty;
-      __type_ = file_type::none;
-      __sym_perms_ = __non_sym_perms_ = perms::unknown;
-      __size_ = __nlink_ = uintmax_t(-1);
-      __write_time_ = file_time_type::min();
-    }
-  };
-
-  _LIBCPP_INLINE_VISIBILITY
-  static __cached_data __create_iter_result(file_type __ft) {
-    __cached_data __data;
-    __data.__type_ = __ft;
-    __data.__cache_type_ = [&]() {
-      switch (__ft) {
-      case file_type::none:
-        return _Empty;
-      case file_type::symlink:
-        return _IterSymlink;
-      default:
-        return _IterNonSymlink;
-      }
-    }();
-    return __data;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void __assign_iter_entry(_Path&& __p, __cached_data __dt) {
-    __p_ = std::move(__p);
-    __data_ = __dt;
-  }
-
-  _LIBCPP_FUNC_VIS
-  error_code __do_refresh() noexcept;
-
-  _LIBCPP_INLINE_VISIBILITY
-  static bool __is_dne_error(error_code const& __ec) {
-    if (!__ec)
-      return true;
-    switch (static_cast<errc>(__ec.value())) {
-    case errc::no_such_file_or_directory:
-    case errc::not_a_directory:
-      return true;
-    default:
-      return false;
-    }
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void __handle_error(const char* __msg, error_code* __dest_ec,
-                      error_code const& __ec, bool __allow_dne = false) const {
-    if (__dest_ec) {
-      *__dest_ec = __ec;
-      return;
-    }
-    if (__ec && (!__allow_dne || !__is_dne_error(__ec)))
-      __throw_filesystem_error(__msg, __p_, __ec);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void __refresh(error_code* __ec = nullptr) {
-    __handle_error("in directory_entry::refresh", __ec, __do_refresh(),
-                   /*allow_dne*/ true);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_type __get_sym_ft(error_code* __ec = nullptr) const {
-    switch (__data_.__cache_type_) {
-    case _Empty:
-      return __symlink_status(__p_, __ec).type();
-    case _IterSymlink:
-    case _RefreshSymlink:
-    case _RefreshSymlinkUnresolved:
-      if (__ec)
-        __ec->clear();
-      return file_type::symlink;
-    case _IterNonSymlink:
-    case _RefreshNonSymlink:
-      file_status __st(__data_.__type_);
-      if (__ec && !_VSTD_FS::exists(__st))
-        *__ec = make_error_code(errc::no_such_file_or_directory);
-      else if (__ec)
-        __ec->clear();
-      return __data_.__type_;
-    }
-    _LIBCPP_UNREACHABLE();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_type __get_ft(error_code* __ec = nullptr) const {
-    switch (__data_.__cache_type_) {
-    case _Empty:
-    case _IterSymlink:
-    case _RefreshSymlinkUnresolved:
-      return __status(__p_, __ec).type();
-    case _IterNonSymlink:
-    case _RefreshNonSymlink:
-    case _RefreshSymlink: {
-      file_status __st(__data_.__type_);
-      if (__ec && !_VSTD_FS::exists(__st))
-        *__ec = make_error_code(errc::no_such_file_or_directory);
-      else if (__ec)
-        __ec->clear();
-      return __data_.__type_;
-    }
-    }
-    _LIBCPP_UNREACHABLE();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_status __get_status(error_code* __ec = nullptr) const {
-    switch (__data_.__cache_type_) {
-    case _Empty:
-    case _IterNonSymlink:
-    case _IterSymlink:
-    case _RefreshSymlinkUnresolved:
-      return __status(__p_, __ec);
-    case _RefreshNonSymlink:
-    case _RefreshSymlink:
-      return file_status(__get_ft(__ec), __data_.__non_sym_perms_);
-    }
-    _LIBCPP_UNREACHABLE();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_status __get_symlink_status(error_code* __ec = nullptr) const {
-    switch (__data_.__cache_type_) {
-    case _Empty:
-    case _IterNonSymlink:
-    case _IterSymlink:
-      return __symlink_status(__p_, __ec);
-    case _RefreshNonSymlink:
-      return file_status(__get_sym_ft(__ec), __data_.__non_sym_perms_);
-    case _RefreshSymlink:
-    case _RefreshSymlinkUnresolved:
-      return file_status(__get_sym_ft(__ec), __data_.__sym_perms_);
-    }
-    _LIBCPP_UNREACHABLE();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  uintmax_t __get_size(error_code* __ec = nullptr) const {
-    switch (__data_.__cache_type_) {
-    case _Empty:
-    case _IterNonSymlink:
-    case _IterSymlink:
-    case _RefreshSymlinkUnresolved:
-      return _VSTD_FS::__file_size(__p_, __ec);
-    case _RefreshSymlink:
-    case _RefreshNonSymlink: {
-      error_code __m_ec;
-      file_status __st(__get_ft(&__m_ec));
-      __handle_error("in directory_entry::file_size", __ec, __m_ec);
-      if (_VSTD_FS::exists(__st) && !_VSTD_FS::is_regular_file(__st)) {
-        errc __err_kind = _VSTD_FS::is_directory(__st) ? errc::is_a_directory
-                                                       : errc::not_supported;
-        __handle_error("in directory_entry::file_size", __ec,
-                       make_error_code(__err_kind));
-      }
-      return __data_.__size_;
-    }
-    }
-    _LIBCPP_UNREACHABLE();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  uintmax_t __get_nlink(error_code* __ec = nullptr) const {
-    switch (__data_.__cache_type_) {
-    case _Empty:
-    case _IterNonSymlink:
-    case _IterSymlink:
-    case _RefreshSymlinkUnresolved:
-      return _VSTD_FS::__hard_link_count(__p_, __ec);
-    case _RefreshSymlink:
-    case _RefreshNonSymlink: {
-      error_code __m_ec;
-      (void)__get_ft(&__m_ec);
-      __handle_error("in directory_entry::hard_link_count", __ec, __m_ec);
-      return __data_.__nlink_;
-    }
-    }
-    _LIBCPP_UNREACHABLE();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  file_time_type __get_write_time(error_code* __ec = nullptr) const {
-    switch (__data_.__cache_type_) {
-    case _Empty:
-    case _IterNonSymlink:
-    case _IterSymlink:
-    case _RefreshSymlinkUnresolved:
-      return _VSTD_FS::__last_write_time(__p_, __ec);
-    case _RefreshSymlink:
-    case _RefreshNonSymlink: {
-      error_code __m_ec;
-      file_status __st(__get_ft(&__m_ec));
-      __handle_error("in directory_entry::last_write_time", __ec, __m_ec);
-      if (_VSTD_FS::exists(__st) &&
-          __data_.__write_time_ == file_time_type::min())
-        __handle_error("in directory_entry::last_write_time", __ec,
-                       make_error_code(errc::value_too_large));
-      return __data_.__write_time_;
-    }
-    }
-    _LIBCPP_UNREACHABLE();
-  }
-
-private:
-  _Path __p_;
-  __cached_data __data_;
-};
-
-class __dir_element_proxy {
-public:
-  inline _LIBCPP_INLINE_VISIBILITY directory_entry operator*() {
-    return _VSTD::move(__elem_);
-  }
-
-private:
-  friend class directory_iterator;
-  friend class recursive_directory_iterator;
-  explicit __dir_element_proxy(directory_entry const& __e) : __elem_(__e) {}
-  __dir_element_proxy(__dir_element_proxy&& __o)
-      : __elem_(_VSTD::move(__o.__elem_)) {}
-  directory_entry __elem_;
-};
-
-class directory_iterator {
-public:
-  typedef directory_entry value_type;
-  typedef ptrdiff_t difference_type;
-  typedef value_type const* pointer;
-  typedef value_type const& reference;
-  typedef input_iterator_tag iterator_category;
-
-public:
-  //ctor & dtor
-  directory_iterator() noexcept {}
-
-  explicit directory_iterator(const path& __p)
-      : directory_iterator(__p, nullptr) {}
-
-  directory_iterator(const path& __p, directory_options __opts)
-      : directory_iterator(__p, nullptr, __opts) {}
-
-  directory_iterator(const path& __p, error_code& __ec)
-      : directory_iterator(__p, &__ec) {}
-
-  directory_iterator(const path& __p, directory_options __opts,
-                     error_code& __ec)
-      : directory_iterator(__p, &__ec, __opts) {}
-
-  directory_iterator(const directory_iterator&) = default;
-  directory_iterator(directory_iterator&&) = default;
-  directory_iterator& operator=(const directory_iterator&) = default;
-
-  directory_iterator& operator=(directory_iterator&& __o) noexcept {
-    // non-default implementation provided to support self-move assign.
-    if (this != &__o) {
-      __imp_ = _VSTD::move(__o.__imp_);
-    }
-    return *this;
-  }
-
-  ~directory_iterator() = default;
-
-  const directory_entry& operator*() const {
-    _LIBCPP_ASSERT(__imp_, "The end iterator cannot be dereferenced");
-    return __dereference();
-  }
-
-  const directory_entry* operator->() const { return &**this; }
-
-  directory_iterator& operator++() { return __increment(); }
-
-  __dir_element_proxy operator++(int) {
-    __dir_element_proxy __p(**this);
-    __increment();
-    return __p;
-  }
-
-  directory_iterator& increment(error_code& __ec) { return __increment(&__ec); }
-
-private:
-  inline _LIBCPP_INLINE_VISIBILITY friend bool
-  operator==(const directory_iterator& __lhs,
-             const directory_iterator& __rhs) noexcept;
-
-  // construct the dir_stream
-  _LIBCPP_FUNC_VIS
-  directory_iterator(const path&, error_code*,
-                     directory_options = directory_options::none);
-
-  _LIBCPP_FUNC_VIS
-  directory_iterator& __increment(error_code* __ec = nullptr);
-
-  _LIBCPP_FUNC_VIS
-  const directory_entry& __dereference() const;
-
-private:
-  shared_ptr<__dir_stream> __imp_;
-};
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-operator==(const directory_iterator& __lhs,
-           const directory_iterator& __rhs) noexcept {
-  return __lhs.__imp_ == __rhs.__imp_;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-operator!=(const directory_iterator& __lhs,
-           const directory_iterator& __rhs) noexcept {
-  return !(__lhs == __rhs);
-}
-
-// enable directory_iterator range-based for statements
-inline _LIBCPP_INLINE_VISIBILITY directory_iterator
-begin(directory_iterator __iter) noexcept {
-  return __iter;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY directory_iterator
-end(const directory_iterator&) noexcept {
-  return directory_iterator();
-}
-
-class recursive_directory_iterator {
-public:
-  using value_type = directory_entry;
-  using difference_type = std::ptrdiff_t;
-  using pointer = directory_entry const*;
-  using reference = directory_entry const&;
-  using iterator_category = std::input_iterator_tag;
-
-public:
-  // constructors and destructor
-  _LIBCPP_INLINE_VISIBILITY
-  recursive_directory_iterator() noexcept : __rec_(false) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  explicit recursive_directory_iterator(
-      const path& __p, directory_options __xoptions = directory_options::none)
-      : recursive_directory_iterator(__p, __xoptions, nullptr) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  recursive_directory_iterator(const path& __p, directory_options __xoptions,
-                               error_code& __ec)
-      : recursive_directory_iterator(__p, __xoptions, &__ec) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  recursive_directory_iterator(const path& __p, error_code& __ec)
-      : recursive_directory_iterator(__p, directory_options::none, &__ec) {}
-
-  recursive_directory_iterator(const recursive_directory_iterator&) = default;
-  recursive_directory_iterator(recursive_directory_iterator&&) = default;
-
-  recursive_directory_iterator&
-  operator=(const recursive_directory_iterator&) = default;
-
-  _LIBCPP_INLINE_VISIBILITY
-  recursive_directory_iterator&
-  operator=(recursive_directory_iterator&& __o) noexcept {
-    // non-default implementation provided to support self-move assign.
-    if (this != &__o) {
-      __imp_ = _VSTD::move(__o.__imp_);
-      __rec_ = __o.__rec_;
-    }
-    return *this;
-  }
-
-  ~recursive_directory_iterator() = default;
-
-  _LIBCPP_INLINE_VISIBILITY
-  const directory_entry& operator*() const { return __dereference(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  const directory_entry* operator->() const { return &__dereference(); }
-
-  recursive_directory_iterator& operator++() { return __increment(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  __dir_element_proxy operator++(int) {
-    __dir_element_proxy __p(**this);
-    __increment();
-    return __p;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  recursive_directory_iterator& increment(error_code& __ec) {
-    return __increment(&__ec);
-  }
-
-  _LIBCPP_FUNC_VIS directory_options options() const;
-  _LIBCPP_FUNC_VIS int depth() const;
-
-  _LIBCPP_INLINE_VISIBILITY
-  void pop() { __pop(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void pop(error_code& __ec) { __pop(&__ec); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  bool recursion_pending() const { return __rec_; }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void disable_recursion_pending() { __rec_ = false; }
-
-private:
-  recursive_directory_iterator(const path& __p, directory_options __opt,
-                               error_code* __ec);
-
-  _LIBCPP_FUNC_VIS
-  const directory_entry& __dereference() const;
-
-  _LIBCPP_FUNC_VIS
-  bool __try_recursion(error_code* __ec);
-
-  _LIBCPP_FUNC_VIS
-  void __advance(error_code* __ec = nullptr);
-
-  _LIBCPP_FUNC_VIS
-  recursive_directory_iterator& __increment(error_code* __ec = nullptr);
-
-  _LIBCPP_FUNC_VIS
-  void __pop(error_code* __ec = nullptr);
-
-  inline _LIBCPP_INLINE_VISIBILITY friend bool
-  operator==(const recursive_directory_iterator&,
-             const recursive_directory_iterator&) noexcept;
-
-  struct __shared_imp;
-  shared_ptr<__shared_imp> __imp_;
-  bool __rec_;
-}; // class recursive_directory_iterator
-
-inline _LIBCPP_INLINE_VISIBILITY bool
-operator==(const recursive_directory_iterator& __lhs,
-           const recursive_directory_iterator& __rhs) noexcept {
-  return __lhs.__imp_ == __rhs.__imp_;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline bool operator!=(const recursive_directory_iterator& __lhs,
-                       const recursive_directory_iterator& __rhs) noexcept {
-  return !(__lhs == __rhs);
-}
-// enable recursive_directory_iterator range-based for statements
-inline _LIBCPP_INLINE_VISIBILITY recursive_directory_iterator
-begin(recursive_directory_iterator __iter) noexcept {
-  return __iter;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY recursive_directory_iterator
-end(const recursive_directory_iterator&) noexcept {
-  return recursive_directory_iterator();
-}
-
-_LIBCPP_END_NAMESPACE_FILESYSTEM
-
-#endif // !_LIBCPP_CXX03_LANG
-
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_FILESYSTEM
diff --git a/lib/libcxx/include/float.h b/lib/libcxx/include/float.h
deleted file mode 100644
index 759ac8e7954..00000000000
--- a/lib/libcxx/include/float.h
+++ /dev/null
@@ -1,94 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- float.h ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_FLOAT_H
-#define _LIBCPP_FLOAT_H
-
-/*
-    float.h synopsis
-
-Macros:
-
-    FLT_ROUNDS
-    FLT_EVAL_METHOD     // C99
-    FLT_RADIX
-
-    FLT_MANT_DIG
-    DBL_MANT_DIG
-    LDBL_MANT_DIG
-
-    FLT_HAS_SUBNORM     // C11
-    DBL_HAS_SUBNORM     // C11
-    LDBL_HAS_SUBNORM    // C11
-
-    DECIMAL_DIG         // C99
-    FLT_DECIMAL_DIG     // C11
-    DBL_DECIMAL_DIG     // C11
-    LDBL_DECIMAL_DIG    // C11
-
-    FLT_DIG
-    DBL_DIG
-    LDBL_DIG
-
-    FLT_MIN_EXP
-    DBL_MIN_EXP
-    LDBL_MIN_EXP
-
-    FLT_MIN_10_EXP
-    DBL_MIN_10_EXP
-    LDBL_MIN_10_EXP
-
-    FLT_MAX_EXP
-    DBL_MAX_EXP
-    LDBL_MAX_EXP
-
-    FLT_MAX_10_EXP
-    DBL_MAX_10_EXP
-    LDBL_MAX_10_EXP
-
-    FLT_MAX
-    DBL_MAX
-    LDBL_MAX
-
-    FLT_EPSILON
-    DBL_EPSILON
-    LDBL_EPSILON
-
-    FLT_MIN
-    DBL_MIN
-    LDBL_MIN
-
-    FLT_TRUE_MIN        // C11
-    DBL_TRUE_MIN        // C11
-    LDBL_TRUE_MIN       // C11
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <float.h>
-
-#ifdef __cplusplus
-
-#ifndef FLT_EVAL_METHOD
-#define FLT_EVAL_METHOD __FLT_EVAL_METHOD__
-#endif
-
-#ifndef DECIMAL_DIG
-#define DECIMAL_DIG __DECIMAL_DIG__
-#endif
-
-#endif // __cplusplus
-
-#endif  // _LIBCPP_FLOAT_H
diff --git a/lib/libcxx/include/forward_list b/lib/libcxx/include/forward_list
deleted file mode 100644
index b506acd1ff2..00000000000
--- a/lib/libcxx/include/forward_list
+++ /dev/null
@@ -1,1768 +0,0 @@
-// -*- C++ -*-
-//===----------------------- forward_list ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_FORWARD_LIST
-#define _LIBCPP_FORWARD_LIST
-
-/*
-    forward_list synopsis
-
-namespace std
-{
-
-template <class T, class Allocator = allocator<T>>
-class forward_list
-{
-public:
-    typedef T         value_type;
-    typedef Allocator allocator_type;
-
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef <details> iterator;
-    typedef <details> const_iterator;
-
-    forward_list()
-        noexcept(is_nothrow_default_constructible<allocator_type>::value);
-    explicit forward_list(const allocator_type& a);
-    explicit forward_list(size_type n);
-    explicit forward_list(size_type n, const allocator_type& a); // C++14
-    forward_list(size_type n, const value_type& v);
-    forward_list(size_type n, const value_type& v, const allocator_type& a);
-    template <class InputIterator>
-        forward_list(InputIterator first, InputIterator last);
-    template <class InputIterator>
-        forward_list(InputIterator first, InputIterator last, const allocator_type& a);
-    forward_list(const forward_list& x);
-    forward_list(const forward_list& x, const allocator_type& a);
-    forward_list(forward_list&& x)
-        noexcept(is_nothrow_move_constructible<allocator_type>::value);
-    forward_list(forward_list&& x, const allocator_type& a);
-    forward_list(initializer_list<value_type> il);
-    forward_list(initializer_list<value_type> il, const allocator_type& a);
-
-    ~forward_list();
-
-    forward_list& operator=(const forward_list& x);
-    forward_list& operator=(forward_list&& x)
-        noexcept(
-             allocator_type::propagate_on_container_move_assignment::value &&
-             is_nothrow_move_assignable<allocator_type>::value);
-    forward_list& operator=(initializer_list<value_type> il);
-
-    template <class InputIterator>
-        void assign(InputIterator first, InputIterator last);
-    void assign(size_type n, const value_type& v);
-    void assign(initializer_list<value_type> il);
-
-    allocator_type get_allocator() const noexcept;
-
-    iterator       begin() noexcept;
-    const_iterator begin() const noexcept;
-    iterator       end() noexcept;
-    const_iterator end() const noexcept;
-
-    const_iterator cbegin() const noexcept;
-    const_iterator cend() const noexcept;
-
-    iterator       before_begin() noexcept;
-    const_iterator before_begin() const noexcept;
-    const_iterator cbefore_begin() const noexcept;
-
-    bool empty() const noexcept;
-    size_type max_size() const noexcept;
-
-    reference       front();
-    const_reference front() const;
-
-    template <class... Args> reference emplace_front(Args&&... args);  // reference in C++17
-    void push_front(const value_type& v);
-    void push_front(value_type&& v);
-
-    void pop_front();
-
-    template <class... Args>
-        iterator emplace_after(const_iterator p, Args&&... args);
-    iterator insert_after(const_iterator p, const value_type& v);
-    iterator insert_after(const_iterator p, value_type&& v);
-    iterator insert_after(const_iterator p, size_type n, const value_type& v);
-    template <class InputIterator>
-        iterator insert_after(const_iterator p,
-                              InputIterator first, InputIterator last);
-    iterator insert_after(const_iterator p, initializer_list<value_type> il);
-
-    iterator erase_after(const_iterator p);
-    iterator erase_after(const_iterator first, const_iterator last);
-
-    void swap(forward_list& x)
-        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
-
-    void resize(size_type n);
-    void resize(size_type n, const value_type& v);
-    void clear() noexcept;
-
-    void splice_after(const_iterator p, forward_list& x);
-    void splice_after(const_iterator p, forward_list&& x);
-    void splice_after(const_iterator p, forward_list& x, const_iterator i);
-    void splice_after(const_iterator p, forward_list&& x, const_iterator i);
-    void splice_after(const_iterator p, forward_list& x,
-                      const_iterator first, const_iterator last);
-    void splice_after(const_iterator p, forward_list&& x,
-                      const_iterator first, const_iterator last);
-    void remove(const value_type& v);
-    template <class Predicate> void remove_if(Predicate pred);
-    void unique();
-    template <class BinaryPredicate> void unique(BinaryPredicate binary_pred);
-    void merge(forward_list& x);
-    void merge(forward_list&& x);
-    template <class Compare> void merge(forward_list& x, Compare comp);
-    template <class Compare> void merge(forward_list&& x, Compare comp);
-    void sort();
-    template <class Compare> void sort(Compare comp);
-    void reverse() noexcept;
-};
-
-
-template <class InputIterator, class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
-    forward_list(InputIterator, InputIterator, Allocator = Allocator())
-    -> forward_list<typename iterator_traits<InputIterator>::value_type, Allocator>;  // C++17
-
-template <class T, class Allocator>
-    bool operator==(const forward_list<T, Allocator>& x,
-                    const forward_list<T, Allocator>& y);
-
-template <class T, class Allocator>
-    bool operator< (const forward_list<T, Allocator>& x,
-                    const forward_list<T, Allocator>& y);
-
-template <class T, class Allocator>
-    bool operator!=(const forward_list<T, Allocator>& x,
-                    const forward_list<T, Allocator>& y);
-
-template <class T, class Allocator>
-    bool operator> (const forward_list<T, Allocator>& x,
-                    const forward_list<T, Allocator>& y);
-
-template <class T, class Allocator>
-    bool operator>=(const forward_list<T, Allocator>& x,
-                    const forward_list<T, Allocator>& y);
-
-template <class T, class Allocator>
-    bool operator<=(const forward_list<T, Allocator>& x,
-                    const forward_list<T, Allocator>& y);
-
-template <class T, class Allocator>
-    void swap(forward_list<T, Allocator>& x, forward_list<T, Allocator>& y)
-         noexcept(noexcept(x.swap(y)));
-
-template <class T, class Allocator, class U>
-    void erase(forward_list<T, Allocator>& c, const U& value);       // C++20
-template <class T, class Allocator, class Predicate>
-    void erase_if(forward_list<T, Allocator>& c, Predicate pred);    // C++20
-
-}  // std
-
-*/
-
-#include <__config>
-#include <initializer_list>
-#include <memory>
-#include <limits>
-#include <iterator>
-#include <algorithm>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp, class _VoidPtr> struct __forward_list_node;
-template <class _NodePtr> struct __forward_begin_node;
-
-
-template <class>
-struct __forward_list_node_value_type;
-
-template <class _Tp, class _VoidPtr>
-struct __forward_list_node_value_type<__forward_list_node<_Tp, _VoidPtr> > {
-  typedef _Tp type;
-};
-
-template <class _NodePtr>
-struct __forward_node_traits {
-
-  typedef typename remove_cv<
-        typename pointer_traits<_NodePtr>::element_type>::type  __node;
-  typedef typename __forward_list_node_value_type<__node>::type __node_value_type;
-  typedef _NodePtr                                              __node_pointer;
-  typedef __forward_begin_node<_NodePtr>                        __begin_node;
-  typedef typename __rebind_pointer<_NodePtr, __begin_node>::type
-                                                                __begin_node_pointer;
-  typedef typename __rebind_pointer<_NodePtr, void>::type       __void_pointer;
-
-#if defined(_LIBCPP_ABI_FORWARD_LIST_REMOVE_NODE_POINTER_UB)
-  typedef __begin_node_pointer __iter_node_pointer;
-#else
-  typedef typename conditional<
-          is_pointer<__void_pointer>::value,
-          __begin_node_pointer,
-          __node_pointer
-    >::type __iter_node_pointer;
-#endif
-
-  typedef typename conditional<
-          is_same<__iter_node_pointer, __node_pointer>::value,
-          __begin_node_pointer,
-          __node_pointer
-    >::type __non_iter_node_pointer;
-
-  _LIBCPP_INLINE_VISIBILITY
-  static __iter_node_pointer __as_iter_node(__iter_node_pointer __p) {
-      return __p;
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  static __iter_node_pointer __as_iter_node(__non_iter_node_pointer __p) {
-      return static_cast<__iter_node_pointer>(static_cast<__void_pointer>(__p));
-  }
-};
-
-template <class _NodePtr>
-struct __forward_begin_node
-{
-    typedef _NodePtr pointer;
-    typedef typename __rebind_pointer<_NodePtr, __forward_begin_node>::type __begin_node_pointer;
-
-    pointer __next_;
-
-    _LIBCPP_INLINE_VISIBILITY __forward_begin_node() : __next_(nullptr) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __begin_node_pointer __next_as_begin() const {
-        return static_cast<__begin_node_pointer>(__next_);
-    }
-};
-
-template <class _Tp, class _VoidPtr>
-struct _LIBCPP_HIDDEN __begin_node_of
-{
-    typedef __forward_begin_node<
-        typename __rebind_pointer<_VoidPtr, __forward_list_node<_Tp, _VoidPtr> >::type
-    > type;
-};
-
-template <class _Tp, class _VoidPtr>
-struct __forward_list_node
-    : public __begin_node_of<_Tp, _VoidPtr>::type
-{
-    typedef _Tp value_type;
-
-    value_type __value_;
-};
-
-
-template <class _Tp, class _Alloc = allocator<_Tp> > class _LIBCPP_TEMPLATE_VIS forward_list;
-template<class _NodeConstPtr> class _LIBCPP_TEMPLATE_VIS __forward_list_const_iterator;
-
-template <class _NodePtr>
-class _LIBCPP_TEMPLATE_VIS __forward_list_iterator
-{
-    typedef __forward_node_traits<_NodePtr>         __traits;
-    typedef typename __traits::__node_pointer       __node_pointer;
-    typedef typename __traits::__begin_node_pointer __begin_node_pointer;
-    typedef typename __traits::__iter_node_pointer  __iter_node_pointer;
-    typedef typename __traits::__void_pointer       __void_pointer;
-
-    __iter_node_pointer __ptr_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __begin_node_pointer __get_begin() const {
-        return static_cast<__begin_node_pointer>(
-                static_cast<__void_pointer>(__ptr_));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __get_unsafe_node_pointer() const {
-        return static_cast<__node_pointer>(
-                static_cast<__void_pointer>(__ptr_));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __forward_list_iterator(nullptr_t) _NOEXCEPT : __ptr_(nullptr) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __forward_list_iterator(__begin_node_pointer __p) _NOEXCEPT
-        : __ptr_(__traits::__as_iter_node(__p)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __forward_list_iterator(__node_pointer __p) _NOEXCEPT
-        : __ptr_(__traits::__as_iter_node(__p)) {}
-
-    template<class, class> friend class _LIBCPP_TEMPLATE_VIS forward_list;
-    template<class> friend class _LIBCPP_TEMPLATE_VIS __forward_list_const_iterator;
-
-public:
-    typedef forward_iterator_tag                              iterator_category;
-    typedef typename __traits::__node_value_type              value_type;
-    typedef value_type&                                       reference;
-    typedef typename pointer_traits<__node_pointer>::difference_type
-                                                              difference_type;
-    typedef typename __rebind_pointer<__node_pointer, value_type>::type pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_iterator() _NOEXCEPT : __ptr_(nullptr) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {return __get_unsafe_node_pointer()->__value_;}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {
-        return pointer_traits<pointer>::pointer_to(__get_unsafe_node_pointer()->__value_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_iterator& operator++()
-    {
-        __ptr_ = __traits::__as_iter_node(__ptr_->__next_);
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_iterator operator++(int)
-    {
-        __forward_list_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __forward_list_iterator& __x,
-                    const __forward_list_iterator& __y)
-        {return __x.__ptr_ == __y.__ptr_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __forward_list_iterator& __x,
-                    const __forward_list_iterator& __y)
-        {return !(__x == __y);}
-};
-
-template <class _NodeConstPtr>
-class _LIBCPP_TEMPLATE_VIS __forward_list_const_iterator
-{
-    static_assert((!is_const<typename pointer_traits<_NodeConstPtr>::element_type>::value), "");
-    typedef _NodeConstPtr _NodePtr;
-
-    typedef __forward_node_traits<_NodePtr>         __traits;
-    typedef typename __traits::__node               __node;
-    typedef typename __traits::__node_pointer       __node_pointer;
-    typedef typename __traits::__begin_node_pointer __begin_node_pointer;
-    typedef typename __traits::__iter_node_pointer  __iter_node_pointer;
-    typedef typename __traits::__void_pointer       __void_pointer;
-
-    __iter_node_pointer __ptr_;
-
-    __begin_node_pointer __get_begin() const {
-        return static_cast<__begin_node_pointer>(
-                static_cast<__void_pointer>(__ptr_));
-    }
-    __node_pointer __get_unsafe_node_pointer() const {
-        return static_cast<__node_pointer>(
-                static_cast<__void_pointer>(__ptr_));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __forward_list_const_iterator(nullptr_t) _NOEXCEPT
-        : __ptr_(nullptr) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __forward_list_const_iterator(__begin_node_pointer __p) _NOEXCEPT
-        : __ptr_(__traits::__as_iter_node(__p)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __forward_list_const_iterator(__node_pointer __p) _NOEXCEPT
-        : __ptr_(__traits::__as_iter_node(__p)) {}
-
-
-    template<class, class> friend class forward_list;
-
-public:
-    typedef forward_iterator_tag                              iterator_category;
-    typedef typename __traits::__node_value_type              value_type;
-    typedef const value_type&                                 reference;
-    typedef typename pointer_traits<__node_pointer>::difference_type
-                                                              difference_type;
-    typedef typename __rebind_pointer<__node_pointer, const value_type>::type
-                                                              pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_const_iterator() _NOEXCEPT : __ptr_(nullptr) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_const_iterator(__forward_list_iterator<__node_pointer> __p) _NOEXCEPT
-        : __ptr_(__p.__ptr_) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {return __get_unsafe_node_pointer()->__value_;}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {return pointer_traits<pointer>::pointer_to(
-                __get_unsafe_node_pointer()->__value_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_const_iterator& operator++()
-    {
-        __ptr_ = __traits::__as_iter_node(__ptr_->__next_);
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_const_iterator operator++(int)
-    {
-        __forward_list_const_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __forward_list_const_iterator& __x,
-                    const __forward_list_const_iterator& __y)
-        {return __x.__ptr_ == __y.__ptr_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __forward_list_const_iterator& __x,
-                           const __forward_list_const_iterator& __y)
-        {return !(__x == __y);}
-};
-
-template <class _Tp, class _Alloc>
-class __forward_list_base
-{
-protected:
-    typedef _Tp    value_type;
-    typedef _Alloc allocator_type;
-
-    typedef typename allocator_traits<allocator_type>::void_pointer  void_pointer;
-    typedef __forward_list_node<value_type, void_pointer>            __node;
-    typedef typename __begin_node_of<value_type, void_pointer>::type __begin_node;
-    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>, __node>::type __node_allocator;
-    typedef allocator_traits<__node_allocator>        __node_traits;
-    typedef typename __node_traits::pointer           __node_pointer;
-
-    typedef typename __rebind_alloc_helper<
-        allocator_traits<allocator_type>, __begin_node
-    >::type                                           __begin_node_allocator;
-    typedef typename allocator_traits<__begin_node_allocator>::pointer
-                                                      __begin_node_pointer;
-
-    static_assert((!is_same<allocator_type, __node_allocator>::value),
-                  "internal allocator type must differ from user-specified "
-                  "type; otherwise overload resolution breaks");
-
-    __compressed_pair<__begin_node, __node_allocator> __before_begin_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __begin_node_pointer        __before_begin() _NOEXCEPT
-        {return pointer_traits<__begin_node_pointer>::pointer_to(__before_begin_.first());}
-    _LIBCPP_INLINE_VISIBILITY
-    __begin_node_pointer __before_begin() const _NOEXCEPT
-        {return pointer_traits<__begin_node_pointer>::pointer_to(const_cast<__begin_node&>(__before_begin_.first()));}
-
-    _LIBCPP_INLINE_VISIBILITY
-          __node_allocator& __alloc() _NOEXCEPT
-            {return __before_begin_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const __node_allocator& __alloc() const _NOEXCEPT
-        {return __before_begin_.second();}
-
-    typedef __forward_list_iterator<__node_pointer>             iterator;
-    typedef __forward_list_const_iterator<__node_pointer>       const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_base()
-        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
-        : __before_begin_(__begin_node()) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __forward_list_base(const allocator_type& __a)
-        : __before_begin_(__begin_node(), __node_allocator(__a)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __forward_list_base(const __node_allocator& __a)
-        : __before_begin_(__begin_node(), __a) {}
-#ifndef _LIBCPP_CXX03_LANG
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_base(__forward_list_base&& __x)
-        _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    __forward_list_base(__forward_list_base&& __x, const allocator_type& __a);
-#endif  // _LIBCPP_CXX03_LANG
-
-private:
-    __forward_list_base(const __forward_list_base&);
-    __forward_list_base& operator=(const __forward_list_base&);
-
-public:
-    ~__forward_list_base();
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __forward_list_base& __x)
-        {__copy_assign_alloc(__x, integral_constant<bool,
-              __node_traits::propagate_on_container_copy_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__forward_list_base& __x)
-        _NOEXCEPT_(!__node_traits::propagate_on_container_move_assignment::value ||
-                   is_nothrow_move_assignable<__node_allocator>::value)
-        {__move_assign_alloc(__x, integral_constant<bool,
-              __node_traits::propagate_on_container_move_assignment::value>());}
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(__forward_list_base& __x)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT;
-#else
-        _NOEXCEPT_(!__node_traits::propagate_on_container_move_assignment::value || 
-                    __is_nothrow_swappable<__node_allocator>::value);
-#endif
-protected:
-    void clear() _NOEXCEPT;
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __forward_list_base&, false_type) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __forward_list_base& __x, true_type)
-    {
-        if (__alloc() != __x.__alloc())
-            clear();
-        __alloc() = __x.__alloc();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__forward_list_base&, false_type) _NOEXCEPT
-        {}
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__forward_list_base& __x, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
-        {__alloc() = _VSTD::move(__x.__alloc());}
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-inline
-__forward_list_base<_Tp, _Alloc>::__forward_list_base(__forward_list_base&& __x)
-        _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value)
-    : __before_begin_(_VSTD::move(__x.__before_begin_))
-{
-    __x.__before_begin()->__next_ = nullptr;
-}
-
-template <class _Tp, class _Alloc>
-inline
-__forward_list_base<_Tp, _Alloc>::__forward_list_base(__forward_list_base&& __x,
-                                                      const allocator_type& __a)
-    : __before_begin_(__begin_node(), __node_allocator(__a))
-{
-    if (__alloc() == __x.__alloc())
-    {
-        __before_begin()->__next_ = __x.__before_begin()->__next_;
-        __x.__before_begin()->__next_ = nullptr;
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-__forward_list_base<_Tp, _Alloc>::~__forward_list_base()
-{
-    clear();
-}
-
-template <class _Tp, class _Alloc>
-inline
-void
-__forward_list_base<_Tp, _Alloc>::swap(__forward_list_base& __x)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT
-#else
-        _NOEXCEPT_(!__node_traits::propagate_on_container_move_assignment::value || 
-                    __is_nothrow_swappable<__node_allocator>::value)
-#endif
-{
-    __swap_allocator(__alloc(), __x.__alloc(), 
-            integral_constant<bool, __node_traits::propagate_on_container_swap::value>());
-    using _VSTD::swap;
-    swap(__before_begin()->__next_, __x.__before_begin()->__next_);
-}
-
-template <class _Tp, class _Alloc>
-void
-__forward_list_base<_Tp, _Alloc>::clear() _NOEXCEPT
-{
-    __node_allocator& __a = __alloc();
-    for (__node_pointer __p = __before_begin()->__next_; __p != nullptr;)
-    {
-        __node_pointer __next = __p->__next_;
-        __node_traits::destroy(__a, _VSTD::addressof(__p->__value_));
-        __node_traits::deallocate(__a, __p, 1);
-        __p = __next;
-    }
-    __before_begin()->__next_ = nullptr;
-}
-
-template <class _Tp, class _Alloc /*= allocator<_Tp>*/>
-class _LIBCPP_TEMPLATE_VIS forward_list
-    : private __forward_list_base<_Tp, _Alloc>
-{
-    typedef __forward_list_base<_Tp, _Alloc> base;
-    typedef typename base::__node_allocator  __node_allocator;
-    typedef typename base::__node               __node;
-    typedef typename base::__node_traits        __node_traits;
-    typedef typename base::__node_pointer       __node_pointer;
-    typedef typename base::__begin_node_pointer __begin_node_pointer;
-
-public:
-    typedef _Tp    value_type;
-    typedef _Alloc allocator_type;
-
-    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
-                  "Allocator::value_type must be same type as value_type");
-
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef typename base::iterator       iterator;
-    typedef typename base::const_iterator const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    forward_list()
-        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
-        {} // = default;
-    _LIBCPP_INLINE_VISIBILITY
-    explicit forward_list(const allocator_type& __a);
-    explicit forward_list(size_type __n);
-#if _LIBCPP_STD_VER > 11
-    explicit forward_list(size_type __n, const allocator_type& __a);
-#endif
-    forward_list(size_type __n, const value_type& __v);
-    forward_list(size_type __n, const value_type& __v, const allocator_type& __a);
-    template <class _InputIterator>
-        forward_list(_InputIterator __f, _InputIterator __l,
-                     typename enable_if<
-                       __is_input_iterator<_InputIterator>::value
-                     >::type* = nullptr);
-    template <class _InputIterator>
-        forward_list(_InputIterator __f, _InputIterator __l,
-                     const allocator_type& __a,
-                     typename enable_if<
-                       __is_input_iterator<_InputIterator>::value
-                     >::type* = nullptr);
-    forward_list(const forward_list& __x);
-    forward_list(const forward_list& __x, const allocator_type& __a);
-
-    forward_list& operator=(const forward_list& __x);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    forward_list(forward_list&& __x)
-        _NOEXCEPT_(is_nothrow_move_constructible<base>::value)
-        : base(_VSTD::move(__x)) {}
-    forward_list(forward_list&& __x, const allocator_type& __a);
-
-    forward_list(initializer_list<value_type> __il);
-    forward_list(initializer_list<value_type> __il, const allocator_type& __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    forward_list& operator=(forward_list&& __x)
-        _NOEXCEPT_(
-             __node_traits::propagate_on_container_move_assignment::value &&
-             is_nothrow_move_assignable<allocator_type>::value);
-
-    _LIBCPP_INLINE_VISIBILITY
-    forward_list& operator=(initializer_list<value_type> __il);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void assign(initializer_list<value_type> __il);
-#endif  // _LIBCPP_CXX03_LANG
-
-    // ~forward_list() = default;
-
-    template <class _InputIterator>
-        typename enable_if
-        <
-            __is_input_iterator<_InputIterator>::value,
-            void
-        >::type
-        assign(_InputIterator __f, _InputIterator __l);
-    void assign(size_type __n, const value_type& __v);
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT
-        {return allocator_type(base::__alloc());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin() _NOEXCEPT
-        {return       iterator(base::__before_begin()->__next_);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT
-        {return const_iterator(base::__before_begin()->__next_);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end() _NOEXCEPT
-        {return       iterator(nullptr);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT
-        {return const_iterator(nullptr);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT
-        {return const_iterator(base::__before_begin()->__next_);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend() const _NOEXCEPT
-        {return const_iterator(nullptr);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       before_begin() _NOEXCEPT
-        {return       iterator(base::__before_begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator before_begin() const _NOEXCEPT
-        {return const_iterator(base::__before_begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbefore_begin() const _NOEXCEPT
-        {return const_iterator(base::__before_begin());}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT
-        {return base::__before_begin()->__next_ == nullptr;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {
-        return std::min<size_type>(
-            __node_traits::max_size(base::__alloc()),
-            numeric_limits<difference_type>::max());
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference       front()       {return base::__before_begin()->__next_->__value_;}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference front() const {return base::__before_begin()->__next_->__value_;}
-
-#ifndef _LIBCPP_CXX03_LANG
-#if _LIBCPP_STD_VER > 14
-    template <class... _Args> reference emplace_front(_Args&&... __args);
-#else
-    template <class... _Args> void      emplace_front(_Args&&... __args);
-#endif
-    void push_front(value_type&& __v);
-#endif  // _LIBCPP_CXX03_LANG
-    void push_front(const value_type& __v);
-
-    void pop_front();
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class... _Args>
-        iterator emplace_after(const_iterator __p, _Args&&... __args);
-
-    iterator insert_after(const_iterator __p, value_type&& __v);
-    iterator insert_after(const_iterator __p, initializer_list<value_type> __il)
-        {return insert_after(__p, __il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-    iterator insert_after(const_iterator __p, const value_type& __v);
-    iterator insert_after(const_iterator __p, size_type __n, const value_type& __v);
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __is_input_iterator<_InputIterator>::value,
-            iterator
-        >::type
-        insert_after(const_iterator __p, _InputIterator __f, _InputIterator __l);
-
-    iterator erase_after(const_iterator __p);
-    iterator erase_after(const_iterator __f, const_iterator __l);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(forward_list& __x)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT
-#else
-        _NOEXCEPT_(!__node_traits::propagate_on_container_swap::value ||
-                   __is_nothrow_swappable<__node_allocator>::value)
-#endif
-        {base::swap(__x);}
-
-    void resize(size_type __n);
-    void resize(size_type __n, const value_type& __v);
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {base::clear();}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void splice_after(const_iterator __p, forward_list&& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    void splice_after(const_iterator __p, forward_list&& __x, const_iterator __i);
-    _LIBCPP_INLINE_VISIBILITY
-    void splice_after(const_iterator __p, forward_list&& __x,
-                      const_iterator __f, const_iterator __l);
-#endif  // _LIBCPP_CXX03_LANG
-    void splice_after(const_iterator __p, forward_list& __x);
-    void splice_after(const_iterator __p, forward_list& __x, const_iterator __i);
-    void splice_after(const_iterator __p, forward_list& __x,
-                      const_iterator __f, const_iterator __l);
-    void remove(const value_type& __v);
-    template <class _Predicate> void remove_if(_Predicate __pred);
-    _LIBCPP_INLINE_VISIBILITY
-    void unique() {unique(__equal_to<value_type>());}
-    template <class _BinaryPredicate> void unique(_BinaryPredicate __binary_pred);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(forward_list&& __x) {merge(__x, __less<value_type>());}
-    template <class _Compare>
-        _LIBCPP_INLINE_VISIBILITY
-        void merge(forward_list&& __x, _Compare __comp)
-        {merge(__x, _VSTD::move(__comp));}
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(forward_list& __x) {merge(__x, __less<value_type>());}
-    template <class _Compare> void merge(forward_list& __x, _Compare __comp);
-    _LIBCPP_INLINE_VISIBILITY
-    void sort() {sort(__less<value_type>());}
-    template <class _Compare> _LIBCPP_INLINE_VISIBILITY void sort(_Compare __comp);
-    void reverse() _NOEXCEPT;
-
-private:
-
-#ifndef _LIBCPP_CXX03_LANG
-    void __move_assign(forward_list& __x, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
-    void __move_assign(forward_list& __x, false_type);
-#endif  // _LIBCPP_CXX03_LANG
-
-    template <class _Compare>
-        static
-        __node_pointer
-        __merge(__node_pointer __f1, __node_pointer __f2, _Compare& __comp);
-
-    template <class _Compare>
-        static
-        __node_pointer
-        __sort(__node_pointer __f, difference_type __sz, _Compare& __comp);
-};
-
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class _InputIterator,
-         class _Alloc = typename std::allocator<typename iterator_traits<_InputIterator>::value_type>,
-         class = typename enable_if<__is_allocator<_Alloc>::value, void>::type
-         >
-forward_list(_InputIterator, _InputIterator)
-  -> forward_list<typename iterator_traits<_InputIterator>::value_type, _Alloc>;
-
-template<class _InputIterator,
-         class _Alloc,
-         class = typename enable_if<__is_allocator<_Alloc>::value, void>::type
-         >
-forward_list(_InputIterator, _InputIterator, _Alloc)
-  -> forward_list<typename iterator_traits<_InputIterator>::value_type, _Alloc>;
-#endif
-
-template <class _Tp, class _Alloc>
-inline
-forward_list<_Tp, _Alloc>::forward_list(const allocator_type& __a)
-    : base(__a)
-{
-}
-
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>::forward_list(size_type __n)
-{
-    if (__n > 0)
-    {
-        __node_allocator& __a = base::__alloc();
-        typedef __allocator_destructor<__node_allocator> _Dp;
-        unique_ptr<__node, _Dp> __h(nullptr, _Dp(__a, 1));
-        for (__begin_node_pointer __p = base::__before_begin(); __n > 0; --__n,
-                                                             __p = __p->__next_as_begin())
-        {
-            __h.reset(__node_traits::allocate(__a, 1));
-            __node_traits::construct(__a, _VSTD::addressof(__h->__value_));
-            __h->__next_ = nullptr;
-            __p->__next_ = __h.release();
-        }
-    }
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>::forward_list(size_type __n,
-                                        const allocator_type& __base_alloc)
-    : base ( __base_alloc )
-{
-    if (__n > 0)
-    {
-        __node_allocator& __a = base::__alloc();
-        typedef __allocator_destructor<__node_allocator> _Dp;
-        unique_ptr<__node, _Dp> __h(nullptr, _Dp(__a, 1));
-        for (__begin_node_pointer __p = base::__before_begin(); __n > 0; --__n,
-                                                             __p = __p->__next_as_begin())
-        {
-            __h.reset(__node_traits::allocate(__a, 1));
-            __node_traits::construct(__a, _VSTD::addressof(__h->__value_));
-            __h->__next_ = nullptr;
-            __p->__next_ = __h.release();
-        }
-    }
-}
-#endif
-
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>::forward_list(size_type __n, const value_type& __v)
-{
-    insert_after(cbefore_begin(), __n, __v);
-}
-
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>::forward_list(size_type __n, const value_type& __v,
-                                        const allocator_type& __a)
-    : base(__a)
-{
-    insert_after(cbefore_begin(), __n, __v);
-}
-
-template <class _Tp, class _Alloc>
-template <class _InputIterator>
-forward_list<_Tp, _Alloc>::forward_list(_InputIterator __f, _InputIterator __l,
-                                        typename enable_if<
-                                          __is_input_iterator<_InputIterator>::value
-                                        >::type*)
-{
-    insert_after(cbefore_begin(), __f, __l);
-}
-
-template <class _Tp, class _Alloc>
-template <class _InputIterator>
-forward_list<_Tp, _Alloc>::forward_list(_InputIterator __f, _InputIterator __l,
-                                        const allocator_type& __a,
-                                        typename enable_if<
-                                          __is_input_iterator<_InputIterator>::value
-                                        >::type*)
-    : base(__a)
-{
-    insert_after(cbefore_begin(), __f, __l);
-}
-
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>::forward_list(const forward_list& __x)
-    : base(
-          __node_traits::select_on_container_copy_construction(__x.__alloc())) {
-  insert_after(cbefore_begin(), __x.begin(), __x.end());
-}
-
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>::forward_list(const forward_list& __x,
-                                        const allocator_type& __a)
-    : base(__a)
-{
-    insert_after(cbefore_begin(), __x.begin(), __x.end());
-}
-
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>&
-forward_list<_Tp, _Alloc>::operator=(const forward_list& __x)
-{
-    if (this != &__x)
-    {
-        base::__copy_assign_alloc(__x);
-        assign(__x.begin(), __x.end());
-    }
-    return *this;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>::forward_list(forward_list&& __x,
-                                        const allocator_type& __a)
-    : base(_VSTD::move(__x), __a)
-{
-    if (base::__alloc() != __x.__alloc())
-    {
-        typedef move_iterator<iterator> _Ip;
-        insert_after(cbefore_begin(), _Ip(__x.begin()), _Ip(__x.end()));
-    }
-}
-
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>::forward_list(initializer_list<value_type> __il)
-{
-    insert_after(cbefore_begin(), __il.begin(), __il.end());
-}
-
-template <class _Tp, class _Alloc>
-forward_list<_Tp, _Alloc>::forward_list(initializer_list<value_type> __il,
-                                        const allocator_type& __a)
-    : base(__a)
-{
-    insert_after(cbefore_begin(), __il.begin(), __il.end());
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::__move_assign(forward_list& __x, true_type)
-    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-{
-    clear();
-    base::__move_assign_alloc(__x);
-    base::__before_begin()->__next_ = __x.__before_begin()->__next_;
-    __x.__before_begin()->__next_ = nullptr;
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::__move_assign(forward_list& __x, false_type)
-{
-    if (base::__alloc() == __x.__alloc())
-        __move_assign(__x, true_type());
-    else
-    {
-        typedef move_iterator<iterator> _Ip;
-        assign(_Ip(__x.begin()), _Ip(__x.end()));
-    }
-}
-
-template <class _Tp, class _Alloc>
-inline
-forward_list<_Tp, _Alloc>&
-forward_list<_Tp, _Alloc>::operator=(forward_list&& __x)
-    _NOEXCEPT_(
-             __node_traits::propagate_on_container_move_assignment::value &&
-             is_nothrow_move_assignable<allocator_type>::value)
-{
-    __move_assign(__x, integral_constant<bool,
-          __node_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
-template <class _Tp, class _Alloc>
-inline
-forward_list<_Tp, _Alloc>&
-forward_list<_Tp, _Alloc>::operator=(initializer_list<value_type> __il)
-{
-    assign(__il.begin(), __il.end());
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-template <class _InputIterator>
-typename enable_if
-<
-    __is_input_iterator<_InputIterator>::value,
-    void
->::type
-forward_list<_Tp, _Alloc>::assign(_InputIterator __f, _InputIterator __l)
-{
-    iterator __i = before_begin();
-    iterator __j = _VSTD::next(__i);
-    iterator __e = end();
-    for (; __j != __e && __f != __l; ++__i, (void) ++__j, ++__f)
-        *__j = *__f;
-    if (__j == __e)
-        insert_after(__i, __f, __l);
-    else
-        erase_after(__i, __e);
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::assign(size_type __n, const value_type& __v)
-{
-    iterator __i = before_begin();
-    iterator __j = _VSTD::next(__i);
-    iterator __e = end();
-    for (; __j != __e && __n > 0; --__n, ++__i, ++__j)
-        *__j = __v;
-    if (__j == __e)
-        insert_after(__i, __n, __v);
-    else
-        erase_after(__i, __e);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-inline
-void
-forward_list<_Tp, _Alloc>::assign(initializer_list<value_type> __il)
-{
-    assign(__il.begin(), __il.end());
-}
-
-template <class _Tp, class _Alloc>
-template <class... _Args>
-#if _LIBCPP_STD_VER > 14
-typename forward_list<_Tp, _Alloc>::reference
-#else
-void
-#endif
-forward_list<_Tp, _Alloc>::emplace_front(_Args&&... __args)
-{
-    __node_allocator& __a = base::__alloc();
-    typedef __allocator_destructor<__node_allocator> _Dp;
-    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
-    __node_traits::construct(__a, _VSTD::addressof(__h->__value_),
-                                  _VSTD::forward<_Args>(__args)...);
-    __h->__next_ = base::__before_begin()->__next_;
-    base::__before_begin()->__next_ = __h.release();
-#if _LIBCPP_STD_VER > 14
-    return base::__before_begin()->__next_->__value_;
-#endif
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::push_front(value_type&& __v)
-{
-    __node_allocator& __a = base::__alloc();
-    typedef __allocator_destructor<__node_allocator> _Dp;
-    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
-    __node_traits::construct(__a, _VSTD::addressof(__h->__value_), _VSTD::move(__v));
-    __h->__next_ = base::__before_begin()->__next_;
-    base::__before_begin()->__next_ = __h.release();
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::push_front(const value_type& __v)
-{
-    __node_allocator& __a = base::__alloc();
-    typedef __allocator_destructor<__node_allocator> _Dp;
-    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
-    __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
-    __h->__next_ = base::__before_begin()->__next_;
-    base::__before_begin()->__next_ = __h.release();
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::pop_front()
-{
-    __node_allocator& __a = base::__alloc();
-    __node_pointer __p = base::__before_begin()->__next_;
-    base::__before_begin()->__next_ = __p->__next_;
-    __node_traits::destroy(__a, _VSTD::addressof(__p->__value_));
-    __node_traits::deallocate(__a, __p, 1);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-template <class... _Args>
-typename forward_list<_Tp, _Alloc>::iterator
-forward_list<_Tp, _Alloc>::emplace_after(const_iterator __p, _Args&&... __args)
-{
-    __begin_node_pointer const __r = __p.__get_begin();
-    __node_allocator& __a = base::__alloc();
-    typedef __allocator_destructor<__node_allocator> _Dp;
-    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
-    __node_traits::construct(__a, _VSTD::addressof(__h->__value_),
-                                  _VSTD::forward<_Args>(__args)...);
-    __h->__next_ = __r->__next_;
-    __r->__next_ = __h.release();
-    return iterator(__r->__next_);
-}
-
-template <class _Tp, class _Alloc>
-typename forward_list<_Tp, _Alloc>::iterator
-forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, value_type&& __v)
-{
-    __begin_node_pointer const __r = __p.__get_begin();
-    __node_allocator& __a = base::__alloc();
-    typedef __allocator_destructor<__node_allocator> _Dp;
-    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
-    __node_traits::construct(__a, _VSTD::addressof(__h->__value_), _VSTD::move(__v));
-    __h->__next_ = __r->__next_;
-    __r->__next_ = __h.release();
-    return iterator(__r->__next_);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-typename forward_list<_Tp, _Alloc>::iterator
-forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, const value_type& __v)
-{
-    __begin_node_pointer const __r = __p.__get_begin();
-    __node_allocator& __a = base::__alloc();
-    typedef __allocator_destructor<__node_allocator> _Dp;
-    unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
-    __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
-    __h->__next_ = __r->__next_;
-    __r->__next_ = __h.release();
-    return iterator(__r->__next_);
-}
-
-template <class _Tp, class _Alloc>
-typename forward_list<_Tp, _Alloc>::iterator
-forward_list<_Tp, _Alloc>::insert_after(const_iterator __p, size_type __n,
-                                        const value_type& __v)
-{
-    __begin_node_pointer __r = __p.__get_begin();
-    if (__n > 0)
-    {
-        __node_allocator& __a = base::__alloc();
-        typedef __allocator_destructor<__node_allocator> _Dp;
-        unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
-        __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
-        __node_pointer __first = __h.release();
-        __node_pointer __last = __first;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (--__n; __n != 0; --__n, __last = __last->__next_)
-            {
-                __h.reset(__node_traits::allocate(__a, 1));
-                __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
-                __last->__next_ = __h.release();
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (__first != nullptr)
-            {
-                __node_pointer __next = __first->__next_;
-                __node_traits::destroy(__a, _VSTD::addressof(__first->__value_));
-                __node_traits::deallocate(__a, __first, 1);
-                __first = __next;
-            }
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __last->__next_ = __r->__next_;
-        __r->__next_ = __first;
-        __r = static_cast<__begin_node_pointer>(__last);
-    }
-    return iterator(__r);
-}
-
-template <class _Tp, class _Alloc>
-template <class _InputIterator>
-typename enable_if
-<
-    __is_input_iterator<_InputIterator>::value,
-    typename forward_list<_Tp, _Alloc>::iterator
->::type
-forward_list<_Tp, _Alloc>::insert_after(const_iterator __p,
-                                        _InputIterator __f, _InputIterator __l)
-{
-    __begin_node_pointer __r = __p.__get_begin();
-    if (__f != __l)
-    {
-        __node_allocator& __a = base::__alloc();
-        typedef __allocator_destructor<__node_allocator> _Dp;
-        unique_ptr<__node, _Dp> __h(__node_traits::allocate(__a, 1), _Dp(__a, 1));
-        __node_traits::construct(__a, _VSTD::addressof(__h->__value_), *__f);
-        __node_pointer __first = __h.release();
-        __node_pointer __last = __first;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (++__f; __f != __l; ++__f, ((void)(__last = __last->__next_)))
-            {
-                __h.reset(__node_traits::allocate(__a, 1));
-                __node_traits::construct(__a, _VSTD::addressof(__h->__value_), *__f);
-                __last->__next_ = __h.release();
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (__first != nullptr)
-            {
-                __node_pointer __next = __first->__next_;
-                __node_traits::destroy(__a, _VSTD::addressof(__first->__value_));
-                __node_traits::deallocate(__a, __first, 1);
-                __first = __next;
-            }
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __last->__next_ = __r->__next_;
-        __r->__next_ = __first;
-        __r = static_cast<__begin_node_pointer>(__last);
-    }
-    return iterator(__r);
-}
-
-template <class _Tp, class _Alloc>
-typename forward_list<_Tp, _Alloc>::iterator
-forward_list<_Tp, _Alloc>::erase_after(const_iterator __f)
-{
-    __begin_node_pointer __p = __f.__get_begin();
-    __node_pointer __n = __p->__next_;
-    __p->__next_ = __n->__next_;
-    __node_allocator& __a = base::__alloc();
-    __node_traits::destroy(__a, _VSTD::addressof(__n->__value_));
-    __node_traits::deallocate(__a, __n, 1);
-    return iterator(__p->__next_);
-}
-
-template <class _Tp, class _Alloc>
-typename forward_list<_Tp, _Alloc>::iterator
-forward_list<_Tp, _Alloc>::erase_after(const_iterator __f, const_iterator __l)
-{
-    __node_pointer __e = __l.__get_unsafe_node_pointer();
-    if (__f != __l)
-    {
-        __begin_node_pointer __bp = __f.__get_begin();
-
-        __node_pointer __n = __bp->__next_;
-        if (__n != __e)
-        {
-            __bp->__next_ = __e;
-            __node_allocator& __a = base::__alloc();
-            do
-            {
-                __node_pointer __tmp = __n->__next_;
-                __node_traits::destroy(__a, _VSTD::addressof(__n->__value_));
-                __node_traits::deallocate(__a, __n, 1);
-                __n = __tmp;
-            } while (__n != __e);
-        }
-    }
-    return iterator(__e);
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::resize(size_type __n)
-{
-    size_type __sz = 0;
-    iterator __p = before_begin();
-    iterator __i = begin();
-    iterator __e = end();
-    for (; __i != __e && __sz < __n; ++__p, ++__i, ++__sz)
-        ;
-    if (__i != __e)
-        erase_after(__p, __e);
-    else
-    {
-        __n -= __sz;
-        if (__n > 0)
-        {
-            __node_allocator& __a = base::__alloc();
-            typedef __allocator_destructor<__node_allocator> _Dp;
-            unique_ptr<__node, _Dp> __h(nullptr, _Dp(__a, 1));
-            for (__begin_node_pointer __ptr = __p.__get_begin(); __n > 0; --__n,
-                                                         __ptr = __ptr->__next_as_begin())
-            {
-                __h.reset(__node_traits::allocate(__a, 1));
-                __node_traits::construct(__a, _VSTD::addressof(__h->__value_));
-                __h->__next_ = nullptr;
-                __ptr->__next_ = __h.release();
-            }
-        }
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::resize(size_type __n, const value_type& __v)
-{
-    size_type __sz = 0;
-    iterator __p = before_begin();
-    iterator __i = begin();
-    iterator __e = end();
-    for (; __i != __e && __sz < __n; ++__p, ++__i, ++__sz)
-        ;
-    if (__i != __e)
-        erase_after(__p, __e);
-    else
-    {
-        __n -= __sz;
-        if (__n > 0)
-        {
-            __node_allocator& __a = base::__alloc();
-            typedef __allocator_destructor<__node_allocator> _Dp;
-            unique_ptr<__node, _Dp> __h(nullptr, _Dp(__a, 1));
-            for (__begin_node_pointer __ptr = __p.__get_begin(); __n > 0; --__n,
-                                                         __ptr = __ptr->__next_as_begin())
-            {
-                __h.reset(__node_traits::allocate(__a, 1));
-                __node_traits::construct(__a, _VSTD::addressof(__h->__value_), __v);
-                __h->__next_ = nullptr;
-                __ptr->__next_ = __h.release();
-            }
-        }
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
-                                        forward_list& __x)
-{
-    if (!__x.empty())
-    {
-        if (__p.__get_begin()->__next_ != nullptr)
-        {
-            const_iterator __lm1 = __x.before_begin();
-            while (__lm1.__get_begin()->__next_ != nullptr)
-                ++__lm1;
-            __lm1.__get_begin()->__next_ = __p.__get_begin()->__next_;
-        }
-        __p.__get_begin()->__next_ = __x.__before_begin()->__next_;
-        __x.__before_begin()->__next_ = nullptr;
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
-                                        forward_list& /*__other*/,
-                                        const_iterator __i)
-{
-    const_iterator __lm1 = _VSTD::next(__i);
-    if (__p != __i && __p != __lm1)
-    {
-        __i.__get_begin()->__next_ = __lm1.__get_begin()->__next_;
-        __lm1.__get_begin()->__next_ = __p.__get_begin()->__next_;
-        __p.__get_begin()->__next_ = __lm1.__get_unsafe_node_pointer();
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
-                                        forward_list& /*__other*/,
-                                        const_iterator __f, const_iterator __l)
-{
-    if (__f != __l && __p != __f)
-    {
-        const_iterator __lm1 = __f;
-        while (__lm1.__get_begin()->__next_ != __l.__get_begin())
-            ++__lm1;
-        if (__f != __lm1)
-        {
-            __lm1.__get_begin()->__next_ = __p.__get_begin()->__next_;
-            __p.__get_begin()->__next_ = __f.__get_begin()->__next_;
-            __f.__get_begin()->__next_ = __l.__get_unsafe_node_pointer();
-        }
-    }
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
-                                        forward_list&& __x)
-{
-    splice_after(__p, __x);
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
-                                        forward_list&& __x,
-                                        const_iterator __i)
-{
-    splice_after(__p, __x, __i);
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-forward_list<_Tp, _Alloc>::splice_after(const_iterator __p,
-                                        forward_list&& __x,
-                                        const_iterator __f, const_iterator __l)
-{
-    splice_after(__p, __x, __f, __l);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::remove(const value_type& __v)
-{
-    forward_list<_Tp, _Alloc> __deleted_nodes; // collect the nodes we're removing
-    iterator __e = end();
-    for (iterator __i = before_begin(); __i.__get_begin()->__next_ != nullptr;)
-    {
-        if (__i.__get_begin()->__next_->__value_ == __v)
-        {
-            iterator __j = _VSTD::next(__i, 2);
-            for (; __j != __e && *__j == __v; ++__j)
-                ;
-            __deleted_nodes.splice_after(__deleted_nodes.before_begin(), *this, __i, __j);
-            if (__j == __e)
-                break;
-            __i = __j;
-        }
-        else
-            ++__i;
-    }
-}
-
-template <class _Tp, class _Alloc>
-template <class _Predicate>
-void
-forward_list<_Tp, _Alloc>::remove_if(_Predicate __pred)
-{
-    iterator __e = end();
-    for (iterator __i = before_begin(); __i.__get_begin()->__next_ != nullptr;)
-    {
-        if (__pred(__i.__get_begin()->__next_->__value_))
-        {
-            iterator __j = _VSTD::next(__i, 2);
-            for (; __j != __e && __pred(*__j); ++__j)
-                ;
-            erase_after(__i, __j);
-            if (__j == __e)
-                break;
-            __i = __j;
-        }
-        else
-            ++__i;
-    }
-}
-
-template <class _Tp, class _Alloc>
-template <class _BinaryPredicate>
-void
-forward_list<_Tp, _Alloc>::unique(_BinaryPredicate __binary_pred)
-{
-    for (iterator __i = begin(), __e = end(); __i != __e;)
-    {
-        iterator __j = _VSTD::next(__i);
-        for (; __j != __e && __binary_pred(*__i, *__j); ++__j)
-            ;
-        if (__i.__get_begin()->__next_ != __j.__get_unsafe_node_pointer())
-            erase_after(__i, __j);
-        __i = __j;
-    }
-}
-
-template <class _Tp, class _Alloc>
-template <class _Compare>
-void
-forward_list<_Tp, _Alloc>::merge(forward_list& __x, _Compare __comp)
-{
-    if (this != &__x)
-    {
-        base::__before_begin()->__next_ = __merge(base::__before_begin()->__next_,
-                                                    __x.__before_begin()->__next_,
-                                                    __comp);
-        __x.__before_begin()->__next_ = nullptr;
-    }
-}
-
-template <class _Tp, class _Alloc>
-template <class _Compare>
-typename forward_list<_Tp, _Alloc>::__node_pointer
-forward_list<_Tp, _Alloc>::__merge(__node_pointer __f1, __node_pointer __f2,
-                                   _Compare& __comp)
-{
-    if (__f1 == nullptr)
-        return __f2;
-    if (__f2 == nullptr)
-        return __f1;
-    __node_pointer __r;
-    if (__comp(__f2->__value_, __f1->__value_))
-    {
-        __node_pointer __t = __f2;
-        while (__t->__next_ != nullptr &&
-                             __comp(__t->__next_->__value_, __f1->__value_))
-            __t = __t->__next_;
-        __r = __f2;
-        __f2 = __t->__next_;
-        __t->__next_ = __f1;
-    }
-    else
-        __r = __f1;
-    __node_pointer __p = __f1;
-    __f1 = __f1->__next_;
-    while (__f1 != nullptr && __f2 != nullptr)
-    {
-        if (__comp(__f2->__value_, __f1->__value_))
-        {
-            __node_pointer __t = __f2;
-            while (__t->__next_ != nullptr &&
-                                 __comp(__t->__next_->__value_, __f1->__value_))
-                __t = __t->__next_;
-            __p->__next_ = __f2;
-            __f2 = __t->__next_;
-            __t->__next_ = __f1;
-        }
-        __p = __f1;
-        __f1 = __f1->__next_;
-    }
-    if (__f2 != nullptr)
-        __p->__next_ = __f2;
-    return __r;
-}
-
-template <class _Tp, class _Alloc>
-template <class _Compare>
-inline
-void
-forward_list<_Tp, _Alloc>::sort(_Compare __comp)
-{
-    base::__before_begin()->__next_ = __sort(base::__before_begin()->__next_,
-                                       _VSTD::distance(begin(), end()), __comp);
-}
-
-template <class _Tp, class _Alloc>
-template <class _Compare>
-typename forward_list<_Tp, _Alloc>::__node_pointer
-forward_list<_Tp, _Alloc>::__sort(__node_pointer __f1, difference_type __sz,
-                                  _Compare& __comp)
-{
-    switch (__sz)
-    {
-    case 0:
-    case 1:
-        return __f1;
-    case 2:
-        if (__comp(__f1->__next_->__value_, __f1->__value_))
-        {
-            __node_pointer __t = __f1->__next_;
-            __t->__next_ = __f1;
-            __f1->__next_ = nullptr;
-            __f1 = __t;
-        }
-        return __f1;
-    }
-    difference_type __sz1 = __sz / 2;
-    difference_type __sz2 = __sz - __sz1;
-    __node_pointer __t = _VSTD::next(iterator(__f1), __sz1 - 1).__get_unsafe_node_pointer();
-    __node_pointer __f2 = __t->__next_;
-    __t->__next_ = nullptr;
-    return __merge(__sort(__f1, __sz1, __comp),
-                   __sort(__f2, __sz2, __comp), __comp);
-}
-
-template <class _Tp, class _Alloc>
-void
-forward_list<_Tp, _Alloc>::reverse() _NOEXCEPT
-{
-    __node_pointer __p = base::__before_begin()->__next_;
-    if (__p != nullptr)
-    {
-        __node_pointer __f = __p->__next_;
-        __p->__next_ = nullptr;
-        while (__f != nullptr)
-        {
-            __node_pointer __t = __f->__next_;
-            __f->__next_ = __p;
-            __p = __f;
-            __f = __t;
-        }
-        base::__before_begin()->__next_ = __p;
-    }
-}
-
-template <class _Tp, class _Alloc>
-bool operator==(const forward_list<_Tp, _Alloc>& __x,
-                const forward_list<_Tp, _Alloc>& __y)
-{
-    typedef forward_list<_Tp, _Alloc> _Cp;
-    typedef typename _Cp::const_iterator _Ip;
-    _Ip __ix = __x.begin();
-    _Ip __ex = __x.end();
-    _Ip __iy = __y.begin();
-    _Ip __ey = __y.end();
-    for (; __ix != __ex && __iy != __ey; ++__ix, ++__iy)
-        if (!(*__ix == *__iy))
-            return false;
-    return (__ix == __ex) == (__iy == __ey);
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(const forward_list<_Tp, _Alloc>& __x,
-                const forward_list<_Tp, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator< (const forward_list<_Tp, _Alloc>& __x,
-                const forward_list<_Tp, _Alloc>& __y)
-{
-    return _VSTD::lexicographical_compare(__x.begin(), __x.end(),
-                                         __y.begin(), __y.end());
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator> (const forward_list<_Tp, _Alloc>& __x,
-                const forward_list<_Tp, _Alloc>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator>=(const forward_list<_Tp, _Alloc>& __x,
-                const forward_list<_Tp, _Alloc>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator<=(const forward_list<_Tp, _Alloc>& __x,
-                const forward_list<_Tp, _Alloc>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(forward_list<_Tp, _Alloc>& __x, forward_list<_Tp, _Alloc>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Tp, class _Allocator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(forward_list<_Tp, _Allocator>& __c, _Predicate __pred)
-{ __c.remove_if(__pred); }
-
-template <class _Tp, class _Allocator, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase(forward_list<_Tp, _Allocator>& __c, const _Up& __v)
-{ _VSTD::erase_if(__c, [&](auto& __elem) { return __elem == __v; }); }
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_FORWARD_LIST
diff --git a/lib/libcxx/include/fstream b/lib/libcxx/include/fstream
deleted file mode 100644
index 711e484e2dc..00000000000
--- a/lib/libcxx/include/fstream
+++ /dev/null
@@ -1,1765 +0,0 @@
-// -*- C++ -*-
-//===------------------------- fstream ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_FSTREAM
-#define _LIBCPP_FSTREAM
-
-/*
-    fstream synopsis
-
-template <class charT, class traits = char_traits<charT> >
-class basic_filebuf
-    : public basic_streambuf<charT, traits>
-{
-public:
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    // 27.9.1.2 Constructors/destructor:
-    basic_filebuf();
-    basic_filebuf(basic_filebuf&& rhs);
-    virtual ~basic_filebuf();
-
-    // 27.9.1.3 Assign/swap:
-    basic_filebuf& operator=(basic_filebuf&& rhs);
-    void swap(basic_filebuf& rhs);
-
-    // 27.9.1.4 Members:
-    bool is_open() const;
-    basic_filebuf* open(const char* s, ios_base::openmode mode);
-    basic_filebuf* open(const string& s, ios_base::openmode mode);
-    basic_filebuf* open(const filesystem::path& p, ios_base::openmode mode); // C++17
-    basic_filebuf* close();
-
-protected:
-    // 27.9.1.5 Overridden virtual functions:
-    virtual streamsize showmanyc();
-    virtual int_type underflow();
-    virtual int_type uflow();
-    virtual int_type pbackfail(int_type c = traits_type::eof());
-    virtual int_type overflow (int_type c = traits_type::eof());
-    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* s, streamsize n);
-    virtual pos_type seekoff(off_type off, ios_base::seekdir way,
-                             ios_base::openmode which = ios_base::in | ios_base::out);
-    virtual pos_type seekpos(pos_type sp,
-                             ios_base::openmode which = ios_base::in | ios_base::out);
-    virtual int sync();
-    virtual void imbue(const locale& loc);
-};
-
-template <class charT, class traits>
-  void
-  swap(basic_filebuf<charT, traits>& x, basic_filebuf<charT, traits>& y);
-
-typedef basic_filebuf<char>    filebuf;
-typedef basic_filebuf<wchar_t> wfilebuf;
-
-template <class charT, class traits = char_traits<charT> >
-class basic_ifstream
-    : public basic_istream<charT,traits>
-{
-public:
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    basic_ifstream();
-    explicit basic_ifstream(const char* s, ios_base::openmode mode = ios_base::in);
-    explicit basic_ifstream(const string& s, ios_base::openmode mode = ios_base::in);
-    explicit basic_ifstream(const filesystem::path& p,
-                            ios_base::openmode mode = ios_base::in); // C++17
-    basic_ifstream(basic_ifstream&& rhs);
-
-    basic_ifstream& operator=(basic_ifstream&& rhs);
-    void swap(basic_ifstream& rhs);
-
-    basic_filebuf<char_type, traits_type>* rdbuf() const;
-    bool is_open() const;
-    void open(const char* s, ios_base::openmode mode = ios_base::in);
-    void open(const string& s, ios_base::openmode mode = ios_base::in);
-    void open(const filesystem::path& s, ios_base::openmode mode = ios_base::in); // C++17
-
-    void close();
-};
-
-template <class charT, class traits>
-  void
-  swap(basic_ifstream<charT, traits>& x, basic_ifstream<charT, traits>& y);
-
-typedef basic_ifstream<char>    ifstream;
-typedef basic_ifstream<wchar_t> wifstream;
-
-template <class charT, class traits = char_traits<charT> >
-class basic_ofstream
-    : public basic_ostream<charT,traits>
-{
-public:
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    basic_ofstream();
-    explicit basic_ofstream(const char* s, ios_base::openmode mode = ios_base::out);
-    explicit basic_ofstream(const string& s, ios_base::openmode mode = ios_base::out);
-    explicit basic_ofstream(const filesystem::path& p,
-                            ios_base::openmode mode = ios_base::out); // C++17
-    basic_ofstream(basic_ofstream&& rhs);
-
-    basic_ofstream& operator=(basic_ofstream&& rhs);
-    void swap(basic_ofstream& rhs);
-
-    basic_filebuf<char_type, traits_type>* rdbuf() const;
-    bool is_open() const;
-    void open(const char* s, ios_base::openmode mode = ios_base::out);
-    void open(const string& s, ios_base::openmode mode = ios_base::out);
-    void open(const filesystem::path& p,
-              ios_base::openmode mode = ios_base::out); // C++17
-
-    void close();
-};
-
-template <class charT, class traits>
-  void
-  swap(basic_ofstream<charT, traits>& x, basic_ofstream<charT, traits>& y);
-
-typedef basic_ofstream<char>    ofstream;
-typedef basic_ofstream<wchar_t> wofstream;
-
-template <class charT, class traits=char_traits<charT> >
-class basic_fstream
-    : public basic_iostream<charT,traits>
-{
-public:
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    basic_fstream();
-    explicit basic_fstream(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
-    explicit basic_fstream(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
-    explicit basic_fstream(const filesystem::path& p,
-                           ios_base::openmode mode = ios_base::in|ios_base::out); C++17
-    basic_fstream(basic_fstream&& rhs);
-
-    basic_fstream& operator=(basic_fstream&& rhs);
-    void swap(basic_fstream& rhs);
-
-    basic_filebuf<char_type, traits_type>* rdbuf() const;
-    bool is_open() const;
-    void open(const char* s, ios_base::openmode mode = ios_base::in|ios_base::out);
-    void open(const string& s, ios_base::openmode mode = ios_base::in|ios_base::out);
-    void open(const filesystem::path& s,
-              ios_base::openmode mode = ios_base::in|ios_base::out); // C++17
-
-    void close();
-};
-
-template <class charT, class traits>
-  void swap(basic_fstream<charT, traits>& x, basic_fstream<charT, traits>& y);
-
-typedef basic_fstream<char>    fstream;
-typedef basic_fstream<wchar_t> wfstream;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <ostream>
-#include <istream>
-#include <__locale>
-#include <cstdio>
-#include <cstdlib>
-#include <filesystem>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_filebuf
-    : public basic_streambuf<_CharT, _Traits>
-{
-public:
-    typedef _CharT                           char_type;
-    typedef _Traits                          traits_type;
-    typedef typename traits_type::int_type   int_type;
-    typedef typename traits_type::pos_type   pos_type;
-    typedef typename traits_type::off_type   off_type;
-    typedef typename traits_type::state_type state_type;
-
-    // 27.9.1.2 Constructors/destructor:
-    basic_filebuf();
-#ifndef _LIBCPP_CXX03_LANG
-    basic_filebuf(basic_filebuf&& __rhs);
-#endif
-    virtual ~basic_filebuf();
-
-    // 27.9.1.3 Assign/swap:
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_filebuf& operator=(basic_filebuf&& __rhs);
-#endif
-    void swap(basic_filebuf& __rhs);
-
-    // 27.9.1.4 Members:
-    _LIBCPP_INLINE_VISIBILITY
-    bool is_open() const;
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-    basic_filebuf* open(const char* __s, ios_base::openmode __mode);
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-    basic_filebuf* open(const wchar_t* __s, ios_base::openmode __mode);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    basic_filebuf* open(const string& __s, ios_base::openmode __mode);
-
-#if _LIBCPP_STD_VER >= 17
-    _LIBCPP_INLINE_VISIBILITY
-    basic_filebuf* open(const _VSTD_FS::path& __p, ios_base::openmode __mode) {
-      return open(__p.c_str(), __mode);
-    }
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    basic_filebuf* __open(int __fd, ios_base::openmode __mode);
-#endif
-    basic_filebuf* close();
-
-    _LIBCPP_INLINE_VISIBILITY
-    inline static const char*
-    __make_mdstring(ios_base::openmode __mode) _NOEXCEPT;
-
-  protected:
-    // 27.9.1.5 Overridden virtual functions:
-    virtual int_type underflow();
-    virtual int_type pbackfail(int_type __c = traits_type::eof());
-    virtual int_type overflow (int_type __c = traits_type::eof());
-    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* __s, streamsize __n);
-    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way,
-                             ios_base::openmode __wch = ios_base::in | ios_base::out);
-    virtual pos_type seekpos(pos_type __sp,
-                             ios_base::openmode __wch = ios_base::in | ios_base::out);
-    virtual int sync();
-    virtual void imbue(const locale& __loc);
-
-private:
-  char* __extbuf_;
-  const char* __extbufnext_;
-  const char* __extbufend_;
-  char __extbuf_min_[8];
-  size_t __ebs_;
-  char_type* __intbuf_;
-  size_t __ibs_;
-  FILE* __file_;
-  const codecvt<char_type, char, state_type>* __cv_;
-  state_type __st_;
-  state_type __st_last_;
-  ios_base::openmode __om_;
-  ios_base::openmode __cm_;
-  bool __owns_eb_;
-  bool __owns_ib_;
-  bool __always_noconv_;
-
-  bool __read_mode();
-  void __write_mode();
-};
-
-template <class _CharT, class _Traits>
-basic_filebuf<_CharT, _Traits>::basic_filebuf()
-    : __extbuf_(0),
-      __extbufnext_(0),
-      __extbufend_(0),
-      __ebs_(0),
-      __intbuf_(0),
-      __ibs_(0),
-      __file_(0),
-      __cv_(nullptr),
-      __st_(),
-      __st_last_(),
-      __om_(0),
-      __cm_(0),
-      __owns_eb_(false),
-      __owns_ib_(false),
-      __always_noconv_(false)
-{
-    if (has_facet<codecvt<char_type, char, state_type> >(this->getloc()))
-    {
-        __cv_ = &use_facet<codecvt<char_type, char, state_type> >(this->getloc());
-        __always_noconv_ = __cv_->always_noconv();
-    }
-    setbuf(0, 4096);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-basic_filebuf<_CharT, _Traits>::basic_filebuf(basic_filebuf&& __rhs)
-    : basic_streambuf<_CharT, _Traits>(__rhs)
-{
-    if (__rhs.__extbuf_ == __rhs.__extbuf_min_)
-    {
-        __extbuf_ = __extbuf_min_;
-        __extbufnext_ = __extbuf_ + (__rhs.__extbufnext_ - __rhs.__extbuf_);
-        __extbufend_ = __extbuf_ + (__rhs.__extbufend_ - __rhs.__extbuf_);
-    }
-    else
-    {
-        __extbuf_ = __rhs.__extbuf_;
-        __extbufnext_ = __rhs.__extbufnext_;
-        __extbufend_ = __rhs.__extbufend_;
-    }
-    __ebs_ = __rhs.__ebs_;
-    __intbuf_ = __rhs.__intbuf_;
-    __ibs_ = __rhs.__ibs_;
-    __file_ = __rhs.__file_;
-    __cv_ = __rhs.__cv_;
-    __st_ = __rhs.__st_;
-    __st_last_ = __rhs.__st_last_;
-    __om_ = __rhs.__om_;
-    __cm_ = __rhs.__cm_;
-    __owns_eb_ = __rhs.__owns_eb_;
-    __owns_ib_ = __rhs.__owns_ib_;
-    __always_noconv_ = __rhs.__always_noconv_;
-    if (__rhs.pbase())
-    {
-        if (__rhs.pbase() == __rhs.__intbuf_)
-            this->setp(__intbuf_, __intbuf_ + (__rhs. epptr() - __rhs.pbase()));
-        else
-            this->setp((char_type*)__extbuf_,
-                       (char_type*)__extbuf_ + (__rhs. epptr() - __rhs.pbase()));
-        this->__pbump(__rhs. pptr() - __rhs.pbase());
-    }
-    else if (__rhs.eback())
-    {
-        if (__rhs.eback() == __rhs.__intbuf_)
-            this->setg(__intbuf_, __intbuf_ + (__rhs.gptr() - __rhs.eback()),
-                                  __intbuf_ + (__rhs.egptr() - __rhs.eback()));
-        else
-            this->setg((char_type*)__extbuf_,
-                       (char_type*)__extbuf_ + (__rhs.gptr() - __rhs.eback()),
-                       (char_type*)__extbuf_ + (__rhs.egptr() - __rhs.eback()));
-    }
-    __rhs.__extbuf_ = 0;
-    __rhs.__extbufnext_ = 0;
-    __rhs.__extbufend_ = 0;
-    __rhs.__ebs_ = 0;
-    __rhs.__intbuf_ = 0;
-    __rhs.__ibs_ = 0;
-    __rhs.__file_ = 0;
-    __rhs.__st_ = state_type();
-    __rhs.__st_last_ = state_type();
-    __rhs.__om_ = 0;
-    __rhs.__cm_ = 0;
-    __rhs.__owns_eb_ = false;
-    __rhs.__owns_ib_ = false;
-    __rhs.setg(0, 0, 0);
-    __rhs.setp(0, 0);
-}
-
-template <class _CharT, class _Traits>
-inline
-basic_filebuf<_CharT, _Traits>&
-basic_filebuf<_CharT, _Traits>::operator=(basic_filebuf&& __rhs)
-{
-    close();
-    swap(__rhs);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-basic_filebuf<_CharT, _Traits>::~basic_filebuf()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        close();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    if (__owns_eb_)
-        delete [] __extbuf_;
-    if (__owns_ib_)
-        delete [] __intbuf_;
-}
-
-template <class _CharT, class _Traits>
-void
-basic_filebuf<_CharT, _Traits>::swap(basic_filebuf& __rhs)
-{
-    basic_streambuf<char_type, traits_type>::swap(__rhs);
-    if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
-    {
-        _VSTD::swap(__extbuf_, __rhs.__extbuf_);
-        _VSTD::swap(__extbufnext_, __rhs.__extbufnext_);
-        _VSTD::swap(__extbufend_, __rhs.__extbufend_);
-    }
-    else
-    {
-        ptrdiff_t __ln = __extbufnext_ - __extbuf_;
-        ptrdiff_t __le = __extbufend_ - __extbuf_;
-        ptrdiff_t __rn = __rhs.__extbufnext_ - __rhs.__extbuf_;
-        ptrdiff_t __re = __rhs.__extbufend_ - __rhs.__extbuf_;
-        if (__extbuf_ == __extbuf_min_ && __rhs.__extbuf_ != __rhs.__extbuf_min_)
-        {
-            __extbuf_ = __rhs.__extbuf_;
-            __rhs.__extbuf_ = __rhs.__extbuf_min_;
-        }
-        else if (__extbuf_ != __extbuf_min_ && __rhs.__extbuf_ == __rhs.__extbuf_min_)
-        {
-            __rhs.__extbuf_ = __extbuf_;
-            __extbuf_ = __extbuf_min_;
-        }
-        __extbufnext_ = __extbuf_ + __rn;
-        __extbufend_ = __extbuf_ + __re;
-        __rhs.__extbufnext_ = __rhs.__extbuf_ + __ln;
-        __rhs.__extbufend_ = __rhs.__extbuf_ + __le;
-    }
-    _VSTD::swap(__ebs_, __rhs.__ebs_);
-    _VSTD::swap(__intbuf_, __rhs.__intbuf_);
-    _VSTD::swap(__ibs_, __rhs.__ibs_);
-    _VSTD::swap(__file_, __rhs.__file_);
-    _VSTD::swap(__cv_, __rhs.__cv_);
-    _VSTD::swap(__st_, __rhs.__st_);
-    _VSTD::swap(__st_last_, __rhs.__st_last_);
-    _VSTD::swap(__om_, __rhs.__om_);
-    _VSTD::swap(__cm_, __rhs.__cm_);
-    _VSTD::swap(__owns_eb_, __rhs.__owns_eb_);
-    _VSTD::swap(__owns_ib_, __rhs.__owns_ib_);
-    _VSTD::swap(__always_noconv_, __rhs.__always_noconv_);
-    if (this->eback() == (char_type*)__rhs.__extbuf_min_)
-    {
-        ptrdiff_t __n = this->gptr() - this->eback();
-        ptrdiff_t __e = this->egptr() - this->eback();
-        this->setg((char_type*)__extbuf_min_,
-                   (char_type*)__extbuf_min_ + __n,
-                   (char_type*)__extbuf_min_ + __e);
-    }
-    else if (this->pbase() == (char_type*)__rhs.__extbuf_min_)
-    {
-        ptrdiff_t __n = this->pptr() - this->pbase();
-        ptrdiff_t __e = this->epptr() - this->pbase();
-        this->setp((char_type*)__extbuf_min_,
-                   (char_type*)__extbuf_min_ + __e);
-        this->__pbump(__n);
-    }
-    if (__rhs.eback() == (char_type*)__extbuf_min_)
-    {
-        ptrdiff_t __n = __rhs.gptr() - __rhs.eback();
-        ptrdiff_t __e = __rhs.egptr() - __rhs.eback();
-        __rhs.setg((char_type*)__rhs.__extbuf_min_,
-                   (char_type*)__rhs.__extbuf_min_ + __n,
-                   (char_type*)__rhs.__extbuf_min_ + __e);
-    }
-    else if (__rhs.pbase() == (char_type*)__extbuf_min_)
-    {
-        ptrdiff_t __n = __rhs.pptr() - __rhs.pbase();
-        ptrdiff_t __e = __rhs.epptr() - __rhs.pbase();
-        __rhs.setp((char_type*)__rhs.__extbuf_min_,
-                   (char_type*)__rhs.__extbuf_min_ + __e);
-        __rhs.__pbump(__n);
-    }
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_filebuf<_CharT, _Traits>& __x, basic_filebuf<_CharT, _Traits>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _CharT, class _Traits>
-inline
-bool
-basic_filebuf<_CharT, _Traits>::is_open() const
-{
-    return __file_ != 0;
-}
-
-template <class _CharT, class _Traits>
-const char* basic_filebuf<_CharT, _Traits>::__make_mdstring(
-    ios_base::openmode __mode) _NOEXCEPT {
-  switch (__mode & ~ios_base::ate) {
-  case ios_base::out:
-  case ios_base::out | ios_base::trunc:
-    return "w";
-  case ios_base::out | ios_base::app:
-  case ios_base::app:
-    return "a";
-  case ios_base::in:
-    return "r";
-  case ios_base::in | ios_base::out:
-    return "r+";
-  case ios_base::in | ios_base::out | ios_base::trunc:
-    return "w+";
-  case ios_base::in | ios_base::out | ios_base::app:
-  case ios_base::in | ios_base::app:
-    return "a+";
-  case ios_base::out | ios_base::binary:
-  case ios_base::out | ios_base::trunc | ios_base::binary:
-    return "wb";
-  case ios_base::out | ios_base::app | ios_base::binary:
-  case ios_base::app | ios_base::binary:
-    return "ab";
-  case ios_base::in | ios_base::binary:
-    return "rb";
-  case ios_base::in | ios_base::out | ios_base::binary:
-    return "r+b";
-  case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
-    return "w+b";
-  case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
-  case ios_base::in | ios_base::app | ios_base::binary:
-    return "a+b";
-  default:
-    return nullptr;
-  }
-  _LIBCPP_UNREACHABLE();
-}
-
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-template <class _CharT, class _Traits>
-basic_filebuf<_CharT, _Traits>*
-basic_filebuf<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
-{
-    basic_filebuf<_CharT, _Traits>* __rt = 0;
-    if (__file_ == 0)
-    {
-      if (const char* __mdstr = __make_mdstring(__mode)) {
-        __rt = this;
-        __file_ = fopen(__s, __mdstr);
-        if (__file_) {
-          __om_ = __mode;
-          if (__mode & ios_base::ate) {
-            if (fseek(__file_, 0, SEEK_END)) {
-              fclose(__file_);
-              __file_ = 0;
-              __rt = 0;
-            }
-          }
-        } else
-          __rt = 0;
-      }
-    }
-    return __rt;
-}
-
-template <class _CharT, class _Traits>
-_LIBCPP_INLINE_VISIBILITY basic_filebuf<_CharT, _Traits>*
-basic_filebuf<_CharT, _Traits>::__open(int __fd, ios_base::openmode __mode) {
-  basic_filebuf<_CharT, _Traits>* __rt = 0;
-  if (__file_ == 0) {
-    if (const char* __mdstr = __make_mdstring(__mode)) {
-      __rt = this;
-      __file_ = fdopen(__fd, __mdstr);
-      if (__file_) {
-        __om_ = __mode;
-        if (__mode & ios_base::ate) {
-          if (fseek(__file_, 0, SEEK_END)) {
-            fclose(__file_);
-            __file_ = 0;
-            __rt = 0;
-          }
-        }
-      } else
-        __rt = 0;
-    }
-  }
-  return __rt;
-}
-
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-// This is basically the same as the char* overload except that it uses _wfopen
-// and long mode strings.
-template <class _CharT, class _Traits>
-basic_filebuf<_CharT, _Traits>*
-basic_filebuf<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
-{
-    basic_filebuf<_CharT, _Traits>* __rt = 0;
-    if (__file_ == 0)
-    {
-        __rt = this;
-        const wchar_t* __mdstr;
-        switch (__mode & ~ios_base::ate)
-        {
-        case ios_base::out:
-        case ios_base::out | ios_base::trunc:
-            __mdstr = L"w";
-            break;
-        case ios_base::out | ios_base::app:
-        case ios_base::app:
-            __mdstr = L"a";
-            break;
-        case ios_base::in:
-            __mdstr = L"r";
-            break;
-        case ios_base::in | ios_base::out:
-            __mdstr = L"r+";
-            break;
-        case ios_base::in | ios_base::out | ios_base::trunc:
-            __mdstr = L"w+";
-            break;
-        case ios_base::in | ios_base::out | ios_base::app:
-        case ios_base::in | ios_base::app:
-            __mdstr = L"a+";
-            break;
-        case ios_base::out | ios_base::binary:
-        case ios_base::out | ios_base::trunc | ios_base::binary:
-            __mdstr = L"wb";
-            break;
-        case ios_base::out | ios_base::app | ios_base::binary:
-        case ios_base::app | ios_base::binary:
-            __mdstr = L"ab";
-            break;
-        case ios_base::in | ios_base::binary:
-            __mdstr = L"rb";
-            break;
-        case ios_base::in | ios_base::out | ios_base::binary:
-            __mdstr = L"r+b";
-            break;
-        case ios_base::in | ios_base::out | ios_base::trunc | ios_base::binary:
-            __mdstr = L"w+b";
-            break;
-        case ios_base::in | ios_base::out | ios_base::app | ios_base::binary:
-        case ios_base::in | ios_base::app | ios_base::binary:
-            __mdstr = L"a+b";
-            break;
-        default:
-            __rt = 0;
-            break;
-        }
-        if (__rt)
-        {
-            __file_ = _wfopen(__s, __mdstr);
-            if (__file_)
-            {
-                __om_ = __mode;
-                if (__mode & ios_base::ate)
-                {
-                    if (fseek(__file_, 0, SEEK_END))
-                    {
-                        fclose(__file_);
-                        __file_ = 0;
-                        __rt = 0;
-                    }
-                }
-            }
-            else
-                __rt = 0;
-        }
-    }
-    return __rt;
-}
-#endif
-
-template <class _CharT, class _Traits>
-inline
-basic_filebuf<_CharT, _Traits>*
-basic_filebuf<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
-{
-    return open(__s.c_str(), __mode);
-}
-#endif
-
-template <class _CharT, class _Traits>
-basic_filebuf<_CharT, _Traits>*
-basic_filebuf<_CharT, _Traits>::close()
-{
-    basic_filebuf<_CharT, _Traits>* __rt = 0;
-    if (__file_)
-    {
-        __rt = this;
-        unique_ptr<FILE, int(*)(FILE*)> __h(__file_, fclose);
-        if (sync())
-            __rt = 0;
-        if (fclose(__h.release()) == 0)
-            __file_ = 0;
-        else
-            __rt = 0;
-        setbuf(0, 0);
-    }
-    return __rt;
-}
-
-template <class _CharT, class _Traits>
-typename basic_filebuf<_CharT, _Traits>::int_type
-basic_filebuf<_CharT, _Traits>::underflow()
-{
-    if (__file_ == 0)
-        return traits_type::eof();
-    bool __initial = __read_mode();
-    char_type __1buf;
-    if (this->gptr() == 0)
-        this->setg(&__1buf, &__1buf+1, &__1buf+1);
-    const size_t __unget_sz = __initial ? 0 : min<size_t>((this->egptr() - this->eback()) / 2, 4);
-    int_type __c = traits_type::eof();
-    if (this->gptr() == this->egptr())
-    {
-        memmove(this->eback(), this->egptr() - __unget_sz, __unget_sz * sizeof(char_type));
-        if (__always_noconv_)
-        {
-            size_t __nmemb = static_cast<size_t>(this->egptr() - this->eback() - __unget_sz);
-            __nmemb = fread(this->eback() + __unget_sz, 1, __nmemb, __file_);
-            if (__nmemb != 0)
-            {
-                this->setg(this->eback(),
-                           this->eback() + __unget_sz,
-                           this->eback() + __unget_sz + __nmemb);
-                __c = traits_type::to_int_type(*this->gptr());
-            }
-        }
-        else
-        {
-            _LIBCPP_ASSERT ( !(__extbufnext_ == NULL && (__extbufend_ != __extbufnext_)), "underflow moving from NULL" );
-            if (__extbufend_ != __extbufnext_)
-                memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
-            __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
-            __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
-            size_t __nmemb = _VSTD::min(static_cast<size_t>(__ibs_ - __unget_sz),
-                                 static_cast<size_t>(__extbufend_ - __extbufnext_));
-            codecvt_base::result __r;
-            __st_last_ = __st_;
-            size_t __nr = fread((void*) const_cast<char *>(__extbufnext_), 1, __nmemb, __file_);
-            if (__nr != 0)
-            {
-                if (!__cv_)
-                    __throw_bad_cast();
-
-                __extbufend_ = __extbufnext_ + __nr;
-                char_type*  __inext;
-                __r = __cv_->in(__st_, __extbuf_, __extbufend_, __extbufnext_,
-                                       this->eback() + __unget_sz,
-                                       this->eback() + __ibs_, __inext);
-                if (__r == codecvt_base::noconv)
-                {
-                    this->setg((char_type*)__extbuf_, (char_type*)__extbuf_, 
-                                          (char_type*)const_cast<char *>(__extbufend_));
-                    __c = traits_type::to_int_type(*this->gptr());
-                }
-                else if (__inext != this->eback() + __unget_sz)
-                {
-                    this->setg(this->eback(), this->eback() + __unget_sz, __inext);
-                    __c = traits_type::to_int_type(*this->gptr());
-                }
-            }
-        }
-    }
-    else
-        __c = traits_type::to_int_type(*this->gptr());
-    if (this->eback() == &__1buf)
-        this->setg(0, 0, 0);
-    return __c;
-}
-
-template <class _CharT, class _Traits>
-typename basic_filebuf<_CharT, _Traits>::int_type
-basic_filebuf<_CharT, _Traits>::pbackfail(int_type __c)
-{
-    if (__file_ && this->eback() < this->gptr())
-    {
-        if (traits_type::eq_int_type(__c, traits_type::eof()))
-        {
-            this->gbump(-1);
-            return traits_type::not_eof(__c);
-        }
-        if ((__om_ & ios_base::out) ||
-            traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1]))
-        {
-            this->gbump(-1);
-            *this->gptr() = traits_type::to_char_type(__c);
-            return __c;
-        }
-    }
-    return traits_type::eof();
-}
-
-template <class _CharT, class _Traits>
-typename basic_filebuf<_CharT, _Traits>::int_type
-basic_filebuf<_CharT, _Traits>::overflow(int_type __c)
-{
-    if (__file_ == 0)
-        return traits_type::eof();
-    __write_mode();
-    char_type __1buf;
-    char_type* __pb_save = this->pbase();
-    char_type* __epb_save = this->epptr();
-    if (!traits_type::eq_int_type(__c, traits_type::eof()))
-    {
-        if (this->pptr() == 0)
-            this->setp(&__1buf, &__1buf+1);
-        *this->pptr() = traits_type::to_char_type(__c);
-        this->pbump(1);
-    }
-    if (this->pptr() != this->pbase())
-    {
-        if (__always_noconv_)
-        {
-            size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
-            if (fwrite(this->pbase(), sizeof(char_type), __nmemb, __file_) != __nmemb)
-                return traits_type::eof();
-        }
-        else
-        {
-            char* __extbe = __extbuf_;
-            codecvt_base::result __r;
-            do
-            {
-                if (!__cv_)
-                    __throw_bad_cast();
-
-                const char_type* __e;
-                __r = __cv_->out(__st_, this->pbase(), this->pptr(), __e,
-                                        __extbuf_, __extbuf_ + __ebs_, __extbe);
-                if (__e == this->pbase())
-                    return traits_type::eof();
-                if (__r == codecvt_base::noconv)
-                {
-                    size_t __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
-                    if (fwrite(this->pbase(), 1, __nmemb, __file_) != __nmemb)
-                        return traits_type::eof();
-                }
-                else if (__r == codecvt_base::ok || __r == codecvt_base::partial)
-                {
-                    size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
-                    if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
-                        return traits_type::eof();
-                    if (__r == codecvt_base::partial)
-                    {
-                        this->setp(const_cast<char_type*>(__e), this->pptr());
-                        this->__pbump(this->epptr() - this->pbase());
-                    }
-                }
-                else
-                    return traits_type::eof();
-            } while (__r == codecvt_base::partial);
-        }
-        this->setp(__pb_save, __epb_save);
-    }
-    return traits_type::not_eof(__c);
-}
-
-template <class _CharT, class _Traits>
-basic_streambuf<_CharT, _Traits>*
-basic_filebuf<_CharT, _Traits>::setbuf(char_type* __s, streamsize __n)
-{
-    this->setg(0, 0, 0);
-    this->setp(0, 0);
-    if (__owns_eb_)
-        delete [] __extbuf_;
-    if (__owns_ib_)
-        delete [] __intbuf_;
-    __ebs_ = __n;
-    if (__ebs_ > sizeof(__extbuf_min_))
-    {
-        if (__always_noconv_ && __s)
-        {
-            __extbuf_ = (char*)__s;
-            __owns_eb_ = false;
-        }
-        else
-        {
-            __extbuf_ = new char[__ebs_];
-            __owns_eb_ = true;
-        }
-    }
-    else
-    {
-        __extbuf_ = __extbuf_min_;
-        __ebs_ = sizeof(__extbuf_min_);
-        __owns_eb_ = false;
-    }
-    if (!__always_noconv_)
-    {
-        __ibs_ = max<streamsize>(__n, sizeof(__extbuf_min_));
-        if (__s && __ibs_ >= sizeof(__extbuf_min_))
-        {
-            __intbuf_ = __s;
-            __owns_ib_ = false;
-        }
-        else
-        {
-            __intbuf_ = new char_type[__ibs_];
-            __owns_ib_ = true;
-        }
-    }
-    else
-    {
-        __ibs_ = 0;
-        __intbuf_ = 0;
-        __owns_ib_ = false;
-    }
-    return this;
-}
-
-template <class _CharT, class _Traits>
-typename basic_filebuf<_CharT, _Traits>::pos_type
-basic_filebuf<_CharT, _Traits>::seekoff(off_type __off, ios_base::seekdir __way,
-                                        ios_base::openmode)
-{
-    if (!__cv_)
-        __throw_bad_cast();
-
-    int __width = __cv_->encoding();
-    if (__file_ == 0 || (__width <= 0 && __off != 0) || sync())
-        return pos_type(off_type(-1));
-    // __width > 0 || __off == 0
-    int __whence;
-    switch (__way)
-    {
-    case ios_base::beg:
-        __whence = SEEK_SET;
-        break;
-    case ios_base::cur:
-        __whence = SEEK_CUR;
-        break;
-    case ios_base::end:
-        __whence = SEEK_END;
-        break;
-    default:
-        return pos_type(off_type(-1));
-    }
-#if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
-    if (fseek(__file_, __width > 0 ? __width * __off : 0, __whence))
-        return pos_type(off_type(-1));
-    pos_type __r = ftell(__file_);
-#else
-    if (fseeko(__file_, __width > 0 ? __width * __off : 0, __whence))
-        return pos_type(off_type(-1));
-    pos_type __r = ftello(__file_);
-#endif
-    __r.state(__st_);
-    return __r;
-}
-
-template <class _CharT, class _Traits>
-typename basic_filebuf<_CharT, _Traits>::pos_type
-basic_filebuf<_CharT, _Traits>::seekpos(pos_type __sp, ios_base::openmode)
-{
-    if (__file_ == 0 || sync())
-        return pos_type(off_type(-1));
-#if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
-    if (fseek(__file_, __sp, SEEK_SET))
-        return pos_type(off_type(-1));
-#else
-    if (fseeko(__file_, __sp, SEEK_SET))
-        return pos_type(off_type(-1));
-#endif
-    __st_ = __sp.state();
-    return __sp;
-}
-
-template <class _CharT, class _Traits>
-int
-basic_filebuf<_CharT, _Traits>::sync()
-{
-    if (__file_ == 0)
-        return 0;
-    if (!__cv_)
-        __throw_bad_cast();
-
-    if (__cm_ & ios_base::out)
-    {
-        if (this->pptr() != this->pbase())
-            if (overflow() == traits_type::eof())
-                return -1;
-        codecvt_base::result __r;
-        do
-        {
-            char* __extbe;
-            __r = __cv_->unshift(__st_, __extbuf_, __extbuf_ + __ebs_, __extbe);
-            size_t __nmemb = static_cast<size_t>(__extbe - __extbuf_);
-            if (fwrite(__extbuf_, 1, __nmemb, __file_) != __nmemb)
-                return -1;
-        } while (__r == codecvt_base::partial);
-        if (__r == codecvt_base::error)
-            return -1;
-        if (fflush(__file_))
-            return -1;
-    }
-    else if (__cm_ & ios_base::in)
-    {
-        off_type __c;
-        state_type __state = __st_last_;
-        bool __update_st = false;
-        if (__always_noconv_)
-            __c = this->egptr() - this->gptr();
-        else
-        {
-            int __width = __cv_->encoding();
-            __c = __extbufend_ - __extbufnext_;
-            if (__width > 0)
-                __c += __width * (this->egptr() - this->gptr());
-            else
-            {
-                if (this->gptr() != this->egptr())
-                {
-                    const int __off =  __cv_->length(__state, __extbuf_,
-                                                     __extbufnext_,
-                                                     this->gptr() - this->eback());
-                    __c += __extbufnext_ - __extbuf_ - __off;
-                    __update_st = true;
-                }
-            }
-        }
-#if defined(_LIBCPP_HAS_NO_OFF_T_FUNCTIONS)
-        if (fseek(__file_, -__c, SEEK_CUR))
-            return -1;
-#else
-        if (fseeko(__file_, -__c, SEEK_CUR))
-            return -1;
-#endif
-        if (__update_st)
-            __st_ = __state;
-        __extbufnext_ = __extbufend_ = __extbuf_;
-        this->setg(0, 0, 0);
-        __cm_ = 0;
-    }
-    return 0;
-}
-
-template <class _CharT, class _Traits>
-void
-basic_filebuf<_CharT, _Traits>::imbue(const locale& __loc)
-{
-    sync();
-    __cv_ = &use_facet<codecvt<char_type, char, state_type> >(__loc);
-    bool __old_anc = __always_noconv_;
-    __always_noconv_ = __cv_->always_noconv();
-    if (__old_anc != __always_noconv_)
-    {
-        this->setg(0, 0, 0);
-        this->setp(0, 0);
-        // invariant, char_type is char, else we couldn't get here
-        if (__always_noconv_)  // need to dump __intbuf_
-        {
-            if (__owns_eb_)
-                delete [] __extbuf_;
-            __owns_eb_ = __owns_ib_;
-            __ebs_ = __ibs_;
-            __extbuf_ = (char*)__intbuf_;
-            __ibs_ = 0;
-            __intbuf_ = 0;
-            __owns_ib_ = false;
-        }
-        else  // need to obtain an __intbuf_.
-        {     // If __extbuf_ is user-supplied, use it, else new __intbuf_
-            if (!__owns_eb_ && __extbuf_ != __extbuf_min_)
-            {
-                __ibs_ = __ebs_;
-                __intbuf_ = (char_type*)__extbuf_;
-                __owns_ib_ = false;
-                __extbuf_ = new char[__ebs_];
-                __owns_eb_ = true;
-            }
-            else
-            {
-                __ibs_ = __ebs_;
-                __intbuf_ = new char_type[__ibs_];
-                __owns_ib_ = true;
-            }
-        }
-    }
-}
-
-template <class _CharT, class _Traits>
-bool
-basic_filebuf<_CharT, _Traits>::__read_mode()
-{
-    if (!(__cm_ & ios_base::in))
-    {
-        this->setp(0, 0);
-        if (__always_noconv_)
-            this->setg((char_type*)__extbuf_,
-                       (char_type*)__extbuf_ + __ebs_,
-                       (char_type*)__extbuf_ + __ebs_);
-        else
-            this->setg(__intbuf_, __intbuf_ + __ibs_, __intbuf_ + __ibs_);
-        __cm_ = ios_base::in;
-        return true;
-    }
-    return false;
-}
-
-template <class _CharT, class _Traits>
-void
-basic_filebuf<_CharT, _Traits>::__write_mode()
-{
-    if (!(__cm_ & ios_base::out))
-    {
-        this->setg(0, 0, 0);
-        if (__ebs_ > sizeof(__extbuf_min_))
-        {
-            if (__always_noconv_)
-                this->setp((char_type*)__extbuf_,
-                           (char_type*)__extbuf_ + (__ebs_ - 1));
-            else
-                this->setp(__intbuf_, __intbuf_ + (__ibs_ - 1));
-        }
-        else
-            this->setp(0, 0);
-        __cm_ = ios_base::out;
-    }
-}
-
-// basic_ifstream
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_ifstream
-    : public basic_istream<_CharT, _Traits>
-{
-public:
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ifstream();
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ifstream(const char* __s, ios_base::openmode __mode = ios_base::in);
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ifstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ifstream(const string& __s, ios_base::openmode __mode = ios_base::in);
-#if _LIBCPP_STD_VER >= 17
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ifstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in)
-      : basic_ifstream(__p.c_str(), __mode) {}
-#endif // _LIBCPP_STD_VER >= 17
-#endif
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ifstream(basic_ifstream&& __rhs);
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ifstream& operator=(basic_ifstream&& __rhs);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(basic_ifstream& __rhs);
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_filebuf<char_type, traits_type>* rdbuf() const;
-    _LIBCPP_INLINE_VISIBILITY
-    bool is_open() const;
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-    void open(const char* __s, ios_base::openmode __mode = ios_base::in);
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in);
-#endif
-    void open(const string& __s, ios_base::openmode __mode = ios_base::in);
-#if _LIBCPP_STD_VER >= 17
-    _LIBCPP_INLINE_VISIBILITY
-    void open(const filesystem::path& __p,
-              ios_base::openmode __mode = ios_base::in) {
-      return open(__p.c_str(), __mode);
-    }
-#endif // _LIBCPP_STD_VER >= 17
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __open(int __fd, ios_base::openmode __mode);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    void close();
-
-private:
-    basic_filebuf<char_type, traits_type> __sb_;
-};
-
-template <class _CharT, class _Traits>
-inline
-basic_ifstream<_CharT, _Traits>::basic_ifstream()
-    : basic_istream<char_type, traits_type>(&__sb_)
-{
-}
-
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-template <class _CharT, class _Traits>
-inline
-basic_ifstream<_CharT, _Traits>::basic_ifstream(const char* __s, ios_base::openmode __mode)
-    : basic_istream<char_type, traits_type>(&__sb_)
-{
-    if (__sb_.open(__s, __mode | ios_base::in) == 0)
-        this->setstate(ios_base::failbit);
-}
-
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-template <class _CharT, class _Traits>
-inline
-basic_ifstream<_CharT, _Traits>::basic_ifstream(const wchar_t* __s, ios_base::openmode __mode)
-    : basic_istream<char_type, traits_type>(&__sb_)
-{
-    if (__sb_.open(__s, __mode | ios_base::in) == 0)
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-template <class _CharT, class _Traits>
-inline
-basic_ifstream<_CharT, _Traits>::basic_ifstream(const string& __s, ios_base::openmode __mode)
-    : basic_istream<char_type, traits_type>(&__sb_)
-{
-    if (__sb_.open(__s, __mode | ios_base::in) == 0)
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-inline
-basic_ifstream<_CharT, _Traits>::basic_ifstream(basic_ifstream&& __rhs)
-    : basic_istream<char_type, traits_type>(_VSTD::move(__rhs)),
-      __sb_(_VSTD::move(__rhs.__sb_))
-{
-    this->set_rdbuf(&__sb_);
-}
-
-template <class _CharT, class _Traits>
-inline
-basic_ifstream<_CharT, _Traits>&
-basic_ifstream<_CharT, _Traits>::operator=(basic_ifstream&& __rhs)
-{
-    basic_istream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
-    __sb_ = _VSTD::move(__rhs.__sb_);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-inline
-void
-basic_ifstream<_CharT, _Traits>::swap(basic_ifstream& __rhs)
-{
-    basic_istream<char_type, traits_type>::swap(__rhs);
-    __sb_.swap(__rhs.__sb_);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_ifstream<_CharT, _Traits>& __x, basic_ifstream<_CharT, _Traits>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _CharT, class _Traits>
-inline
-basic_filebuf<_CharT, _Traits>*
-basic_ifstream<_CharT, _Traits>::rdbuf() const
-{
-    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
-}
-
-template <class _CharT, class _Traits>
-inline
-bool
-basic_ifstream<_CharT, _Traits>::is_open() const
-{
-    return __sb_.is_open();
-}
-
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-template <class _CharT, class _Traits>
-void
-basic_ifstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
-{
-    if (__sb_.open(__s, __mode | ios_base::in))
-        this->clear();
-    else
-        this->setstate(ios_base::failbit);
-}
-
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-template <class _CharT, class _Traits>
-void
-basic_ifstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
-{
-    if (__sb_.open(__s, __mode | ios_base::in))
-        this->clear();
-    else
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-template <class _CharT, class _Traits>
-void
-basic_ifstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
-{
-    if (__sb_.open(__s, __mode | ios_base::in))
-        this->clear();
-    else
-        this->setstate(ios_base::failbit);
-}
-
-template <class _CharT, class _Traits>
-void basic_ifstream<_CharT, _Traits>::__open(int __fd,
-                                             ios_base::openmode __mode) {
-  if (__sb_.__open(__fd, __mode | ios_base::in))
-    this->clear();
-  else
-    this->setstate(ios_base::failbit);
-}
-#endif
-
-template <class _CharT, class _Traits>
-inline
-void
-basic_ifstream<_CharT, _Traits>::close()
-{
-    if (__sb_.close() == 0)
-        this->setstate(ios_base::failbit);
-}
-
-// basic_ofstream
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_ofstream
-    : public basic_ostream<_CharT, _Traits>
-{
-public:
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ofstream();
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ofstream(const char* __s, ios_base::openmode __mode = ios_base::out);
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ofstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::out);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ofstream(const string& __s, ios_base::openmode __mode = ios_base::out);
-
-#if _LIBCPP_STD_VER >= 17
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ofstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::out)
-      : basic_ofstream(__p.c_str(), __mode) {}
-#endif // _LIBCPP_STD_VER >= 17
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ofstream(basic_ofstream&& __rhs);
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ofstream& operator=(basic_ofstream&& __rhs);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(basic_ofstream& __rhs);
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_filebuf<char_type, traits_type>* rdbuf() const;
-    _LIBCPP_INLINE_VISIBILITY
-    bool is_open() const;
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-    void open(const char* __s, ios_base::openmode __mode = ios_base::out);
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::out);
-#endif
-    void open(const string& __s, ios_base::openmode __mode = ios_base::out);
-
-#if _LIBCPP_STD_VER >= 17
-    _LIBCPP_INLINE_VISIBILITY
-    void open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::out)
-    { return open(__p.c_str(), __mode); }
-#endif // _LIBCPP_STD_VER >= 17
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __open(int __fd, ios_base::openmode __mode);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    void close();
-
-private:
-    basic_filebuf<char_type, traits_type> __sb_;
-};
-
-template <class _CharT, class _Traits>
-inline
-basic_ofstream<_CharT, _Traits>::basic_ofstream()
-    : basic_ostream<char_type, traits_type>(&__sb_)
-{
-}
-
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-template <class _CharT, class _Traits>
-inline
-basic_ofstream<_CharT, _Traits>::basic_ofstream(const char* __s, ios_base::openmode __mode)
-    : basic_ostream<char_type, traits_type>(&__sb_)
-{
-    if (__sb_.open(__s, __mode | ios_base::out) == 0)
-        this->setstate(ios_base::failbit);
-}
-
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-template <class _CharT, class _Traits>
-inline
-basic_ofstream<_CharT, _Traits>::basic_ofstream(const wchar_t* __s, ios_base::openmode __mode)
-    : basic_ostream<char_type, traits_type>(&__sb_)
-{
-    if (__sb_.open(__s, __mode | ios_base::out) == 0)
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-template <class _CharT, class _Traits>
-inline
-basic_ofstream<_CharT, _Traits>::basic_ofstream(const string& __s, ios_base::openmode __mode)
-    : basic_ostream<char_type, traits_type>(&__sb_)
-{
-    if (__sb_.open(__s, __mode | ios_base::out) == 0)
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-inline
-basic_ofstream<_CharT, _Traits>::basic_ofstream(basic_ofstream&& __rhs)
-    : basic_ostream<char_type, traits_type>(_VSTD::move(__rhs)),
-      __sb_(_VSTD::move(__rhs.__sb_))
-{
-    this->set_rdbuf(&__sb_);
-}
-
-template <class _CharT, class _Traits>
-inline
-basic_ofstream<_CharT, _Traits>&
-basic_ofstream<_CharT, _Traits>::operator=(basic_ofstream&& __rhs)
-{
-    basic_ostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
-    __sb_ = _VSTD::move(__rhs.__sb_);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-inline
-void
-basic_ofstream<_CharT, _Traits>::swap(basic_ofstream& __rhs)
-{
-    basic_ostream<char_type, traits_type>::swap(__rhs);
-    __sb_.swap(__rhs.__sb_);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_ofstream<_CharT, _Traits>& __x, basic_ofstream<_CharT, _Traits>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _CharT, class _Traits>
-inline
-basic_filebuf<_CharT, _Traits>*
-basic_ofstream<_CharT, _Traits>::rdbuf() const
-{
-    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
-}
-
-template <class _CharT, class _Traits>
-inline
-bool
-basic_ofstream<_CharT, _Traits>::is_open() const
-{
-    return __sb_.is_open();
-}
-
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-template <class _CharT, class _Traits>
-void
-basic_ofstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
-{
-    if (__sb_.open(__s, __mode | ios_base::out))
-        this->clear();
-    else
-        this->setstate(ios_base::failbit);
-}
-
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-template <class _CharT, class _Traits>
-void
-basic_ofstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
-{
-    if (__sb_.open(__s, __mode | ios_base::out))
-        this->clear();
-    else
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-template <class _CharT, class _Traits>
-void
-basic_ofstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
-{
-    if (__sb_.open(__s, __mode | ios_base::out))
-        this->clear();
-    else
-        this->setstate(ios_base::failbit);
-}
-
-template <class _CharT, class _Traits>
-void basic_ofstream<_CharT, _Traits>::__open(int __fd,
-                                             ios_base::openmode __mode) {
-  if (__sb_.__open(__fd, __mode | ios_base::out))
-    this->clear();
-  else
-    this->setstate(ios_base::failbit);
-}
-#endif
-
-template <class _CharT, class _Traits>
-inline
-void
-basic_ofstream<_CharT, _Traits>::close()
-{
-    if (__sb_.close() == 0)
-        this->setstate(ios_base::failbit);
-}
-
-// basic_fstream
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_fstream
-    : public basic_iostream<_CharT, _Traits>
-{
-public:
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_fstream();
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_fstream(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_fstream(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_fstream(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
-
-#if _LIBCPP_STD_VER >= 17
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_fstream(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in | ios_base::out)
-      : basic_fstream(__p.c_str(), __mode) {}
-#endif // _LIBCPP_STD_VER >= 17
-
-#endif
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_fstream(basic_fstream&& __rhs);
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_fstream& operator=(basic_fstream&& __rhs);
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(basic_fstream& __rhs);
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_filebuf<char_type, traits_type>* rdbuf() const;
-    _LIBCPP_INLINE_VISIBILITY
-    bool is_open() const;
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-    void open(const char* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-    void open(const wchar_t* __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
-#endif
-    void open(const string& __s, ios_base::openmode __mode = ios_base::in | ios_base::out);
-
-#if _LIBCPP_STD_VER >= 17
-    _LIBCPP_INLINE_VISIBILITY
-    void open(const filesystem::path& __p, ios_base::openmode __mode = ios_base::in|ios_base::out)
-    { return open(__p.c_str(), __mode); }
-#endif // _LIBCPP_STD_VER >= 17
-
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    void close();
-
-private:
-    basic_filebuf<char_type, traits_type> __sb_;
-};
-
-template <class _CharT, class _Traits>
-inline
-basic_fstream<_CharT, _Traits>::basic_fstream()
-    : basic_iostream<char_type, traits_type>(&__sb_)
-{
-}
-
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-template <class _CharT, class _Traits>
-inline
-basic_fstream<_CharT, _Traits>::basic_fstream(const char* __s, ios_base::openmode __mode)
-    : basic_iostream<char_type, traits_type>(&__sb_)
-{
-    if (__sb_.open(__s, __mode) == 0)
-        this->setstate(ios_base::failbit);
-}
-
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-template <class _CharT, class _Traits>
-inline
-basic_fstream<_CharT, _Traits>::basic_fstream(const wchar_t* __s, ios_base::openmode __mode)
-    : basic_iostream<char_type, traits_type>(&__sb_)
-{
-    if (__sb_.open(__s, __mode) == 0)
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-template <class _CharT, class _Traits>
-inline
-basic_fstream<_CharT, _Traits>::basic_fstream(const string& __s, ios_base::openmode __mode)
-    : basic_iostream<char_type, traits_type>(&__sb_)
-{
-    if (__sb_.open(__s, __mode) == 0)
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-inline
-basic_fstream<_CharT, _Traits>::basic_fstream(basic_fstream&& __rhs)
-    : basic_iostream<char_type, traits_type>(_VSTD::move(__rhs)),
-      __sb_(_VSTD::move(__rhs.__sb_))
-{
-    this->set_rdbuf(&__sb_);
-}
-
-template <class _CharT, class _Traits>
-inline
-basic_fstream<_CharT, _Traits>&
-basic_fstream<_CharT, _Traits>::operator=(basic_fstream&& __rhs)
-{
-    basic_iostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
-    __sb_ = _VSTD::move(__rhs.__sb_);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-inline
-void
-basic_fstream<_CharT, _Traits>::swap(basic_fstream& __rhs)
-{
-    basic_iostream<char_type, traits_type>::swap(__rhs);
-    __sb_.swap(__rhs.__sb_);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_fstream<_CharT, _Traits>& __x, basic_fstream<_CharT, _Traits>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _CharT, class _Traits>
-inline
-basic_filebuf<_CharT, _Traits>*
-basic_fstream<_CharT, _Traits>::rdbuf() const
-{
-    return const_cast<basic_filebuf<char_type, traits_type>*>(&__sb_);
-}
-
-template <class _CharT, class _Traits>
-inline
-bool
-basic_fstream<_CharT, _Traits>::is_open() const
-{
-    return __sb_.is_open();
-}
-
-#ifndef _LIBCPP_HAS_NO_GLOBAL_FILESYSTEM_NAMESPACE
-template <class _CharT, class _Traits>
-void
-basic_fstream<_CharT, _Traits>::open(const char* __s, ios_base::openmode __mode)
-{
-    if (__sb_.open(__s, __mode))
-        this->clear();
-    else
-        this->setstate(ios_base::failbit);
-}
-
-#ifdef _LIBCPP_HAS_OPEN_WITH_WCHAR
-template <class _CharT, class _Traits>
-void
-basic_fstream<_CharT, _Traits>::open(const wchar_t* __s, ios_base::openmode __mode)
-{
-    if (__sb_.open(__s, __mode))
-        this->clear();
-    else
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-template <class _CharT, class _Traits>
-void
-basic_fstream<_CharT, _Traits>::open(const string& __s, ios_base::openmode __mode)
-{
-    if (__sb_.open(__s, __mode))
-        this->clear();
-    else
-        this->setstate(ios_base::failbit);
-}
-#endif
-
-template <class _CharT, class _Traits>
-inline
-void
-basic_fstream<_CharT, _Traits>::close()
-{
-    if (__sb_.close() == 0)
-        this->setstate(ios_base::failbit);
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_FSTREAM
diff --git a/lib/libcxx/include/functional b/lib/libcxx/include/functional
deleted file mode 100644
index 95491879b0c..00000000000
--- a/lib/libcxx/include/functional
+++ /dev/null
@@ -1,2970 +0,0 @@
-// -*- C++ -*-
-//===------------------------ functional ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_FUNCTIONAL
-#define _LIBCPP_FUNCTIONAL
-
-/*
-    functional synopsis
-
-namespace std
-{
-
-template <class Arg, class Result>
-struct unary_function
-{
-    typedef Arg    argument_type;
-    typedef Result result_type;
-};
-
-template <class Arg1, class Arg2, class Result>
-struct binary_function
-{
-    typedef Arg1   first_argument_type;
-    typedef Arg2   second_argument_type;
-    typedef Result result_type;
-};
-
-template <class T>
-class reference_wrapper
-    : public unary_function<T1, R> // if wrapping a unary functor
-    : public binary_function<T1, T2, R> // if wraping a binary functor
-{
-public:
-    // types
-    typedef T type;
-    typedef see below result_type; // Not always defined
-
-    // construct/copy/destroy
-    reference_wrapper(T&) noexcept;
-    reference_wrapper(T&&) = delete; // do not bind to temps
-    reference_wrapper(const reference_wrapper<T>& x) noexcept;
-
-    // assignment
-    reference_wrapper& operator=(const reference_wrapper<T>& x) noexcept;
-
-    // access
-    operator T& () const noexcept;
-    T& get() const noexcept;
-
-    // invoke
-    template <class... ArgTypes>
-      typename result_of<T&(ArgTypes&&...)>::type
-          operator() (ArgTypes&&...) const;
-};
-
-template <class T> reference_wrapper<T> ref(T& t) noexcept;
-template <class T> void ref(const T&& t) = delete;
-template <class T> reference_wrapper<T> ref(reference_wrapper<T>t) noexcept;
-
-template <class T> reference_wrapper<const T> cref(const T& t) noexcept;
-template <class T> void cref(const T&& t) = delete;
-template <class T> reference_wrapper<const T> cref(reference_wrapper<T> t) noexcept;
-
-template <class T> struct unwrap_reference;                                       // since C++20
-template <class T> struct unwrap_ref_decay : unwrap_reference<decay_t<T>> { };    // since C++20
-template <class T> using unwrap_reference_t = typename unwrap_reference<T>::type; // since C++20
-template <class T> using unwrap_ref_decay_t = typename unwrap_ref_decay<T>::type; // since C++20
-
-template <class T> // <class T=void> in C++14
-struct plus : binary_function<T, T, T>
-{
-    T operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct minus : binary_function<T, T, T>
-{
-    T operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct multiplies : binary_function<T, T, T>
-{
-    T operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct divides : binary_function<T, T, T>
-{
-    T operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct modulus : binary_function<T, T, T>
-{
-    T operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct negate : unary_function<T, T>
-{
-    T operator()(const T& x) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct equal_to : binary_function<T, T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct not_equal_to : binary_function<T, T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct greater : binary_function<T, T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct less : binary_function<T, T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct greater_equal : binary_function<T, T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct less_equal : binary_function<T, T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct logical_and : binary_function<T, T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct logical_or : binary_function<T, T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct logical_not : unary_function<T, bool>
-{
-    bool operator()(const T& x) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct bit_and : unary_function<T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct bit_or : unary_function<T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T> // <class T=void> in C++14
-struct bit_xor : unary_function<T, bool>
-{
-    bool operator()(const T& x, const T& y) const;
-};
-
-template <class T=void> // C++14
-struct bit_xor : unary_function<T, bool>
-{
-    bool operator()(const T& x) const;
-};
-
-template <class Predicate>
-class unary_negate // deprecated in C++17
-    : public unary_function<typename Predicate::argument_type, bool>
-{
-public:
-    explicit unary_negate(const Predicate& pred);
-    bool operator()(const typename Predicate::argument_type& x) const;
-};
-
-template <class Predicate> // deprecated in C++17
-unary_negate<Predicate> not1(const Predicate& pred);
-
-template <class Predicate>
-class binary_negate // deprecated in C++17
-    : public binary_function<typename Predicate::first_argument_type,
-                             typename Predicate::second_argument_type,
-                             bool>
-{
-public:
-    explicit binary_negate(const Predicate& pred);
-    bool operator()(const typename Predicate::first_argument_type& x,
-                    const typename Predicate::second_argument_type& y) const;
-};
-
-template <class Predicate> // deprecated in C++17
-binary_negate<Predicate> not2(const Predicate& pred);
-
-template <class F> unspecified not_fn(F&& f); // C++17
-
-template<class T> struct is_bind_expression;
-template<class T> struct is_placeholder;
-
-    // See C++14 20.9.9, Function object binders
-template <class T> inline constexpr bool is_bind_expression_v
-  = is_bind_expression<T>::value; // C++17
-template <class T> inline constexpr int is_placeholder_v
-  = is_placeholder<T>::value; // C++17
-
-
-template<class Fn, class... BoundArgs>
-  unspecified bind(Fn&&, BoundArgs&&...);
-template<class R, class Fn, class... BoundArgs>
-  unspecified bind(Fn&&, BoundArgs&&...);
-
-namespace placeholders {
-  // M is the implementation-defined number of placeholders
-  extern unspecified _1;
-  extern unspecified _2;
-  .
-  .
-  .
-  extern unspecified _Mp;
-}
-
-template <class Operation>
-class binder1st     // deprecated in C++11, removed in C++17
-    : public unary_function<typename Operation::second_argument_type,
-                            typename Operation::result_type>
-{
-protected:
-    Operation                               op;
-    typename Operation::first_argument_type value;
-public:
-    binder1st(const Operation& x, const typename Operation::first_argument_type y);
-    typename Operation::result_type operator()(      typename Operation::second_argument_type& x) const;
-    typename Operation::result_type operator()(const typename Operation::second_argument_type& x) const;
-};
-
-template <class Operation, class T>
-binder1st<Operation> bind1st(const Operation& op, const T& x);  // deprecated in C++11, removed in C++17
-
-template <class Operation>
-class binder2nd     // deprecated in C++11, removed in C++17
-    : public unary_function<typename Operation::first_argument_type,
-                            typename Operation::result_type>
-{
-protected:
-    Operation                                op;
-    typename Operation::second_argument_type value;
-public:
-    binder2nd(const Operation& x, const typename Operation::second_argument_type y);
-    typename Operation::result_type operator()(      typename Operation::first_argument_type& x) const;
-    typename Operation::result_type operator()(const typename Operation::first_argument_type& x) const;
-};
-
-template <class Operation, class T>
-binder2nd<Operation> bind2nd(const Operation& op, const T& x);  // deprecated in C++11, removed in C++17
-
-template <class Arg, class Result>      // deprecated in C++11, removed in C++17
-class pointer_to_unary_function : public unary_function<Arg, Result>
-{
-public:
-    explicit pointer_to_unary_function(Result (*f)(Arg));
-    Result operator()(Arg x) const;
-};
-
-template <class Arg, class Result>
-pointer_to_unary_function<Arg,Result> ptr_fun(Result (*f)(Arg));      // deprecated in C++11, removed in C++17
-
-template <class Arg1, class Arg2, class Result>      // deprecated in C++11, removed in C++17
-class pointer_to_binary_function : public binary_function<Arg1, Arg2, Result>
-{
-public:
-    explicit pointer_to_binary_function(Result (*f)(Arg1, Arg2));
-    Result operator()(Arg1 x, Arg2 y) const;
-};
-
-template <class Arg1, class Arg2, class Result>
-pointer_to_binary_function<Arg1,Arg2,Result> ptr_fun(Result (*f)(Arg1,Arg2));      // deprecated in C++11, removed in C++17
-
-template<class S, class T>      // deprecated in C++11, removed in C++17
-class mem_fun_t : public unary_function<T*, S>
-{
-public:
-    explicit mem_fun_t(S (T::*p)());
-    S operator()(T* p) const;
-};
-
-template<class S, class T, class A>
-class mem_fun1_t : public binary_function<T*, A, S>      // deprecated in C++11, removed in C++17
-{
-public:
-    explicit mem_fun1_t(S (T::*p)(A));
-    S operator()(T* p, A x) const;
-};
-
-template<class S, class T>          mem_fun_t<S,T>    mem_fun(S (T::*f)());      // deprecated in C++11, removed in C++17
-template<class S, class T, class A> mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A));     // deprecated in C++11, removed in C++17
-
-template<class S, class T>
-class mem_fun_ref_t : public unary_function<T, S>      // deprecated in C++11, removed in C++17
-{
-public:
-    explicit mem_fun_ref_t(S (T::*p)());
-    S operator()(T& p) const;
-};
-
-template<class S, class T, class A>
-class mem_fun1_ref_t : public binary_function<T, A, S>      // deprecated in C++11, removed in C++17
-{
-public:
-    explicit mem_fun1_ref_t(S (T::*p)(A));
-    S operator()(T& p, A x) const;
-};
-
-template<class S, class T>          mem_fun_ref_t<S,T>    mem_fun_ref(S (T::*f)());      // deprecated in C++11, removed in C++17
-template<class S, class T, class A> mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A));     // deprecated in C++11, removed in C++17
-
-template <class S, class T>
-class const_mem_fun_t : public unary_function<const T*, S>      // deprecated in C++11, removed in C++17
-{
-public:
-    explicit const_mem_fun_t(S (T::*p)() const);
-    S operator()(const T* p) const;
-};
-
-template <class S, class T, class A>
-class const_mem_fun1_t : public binary_function<const T*, A, S>      // deprecated in C++11, removed in C++17
-{
-public:
-    explicit const_mem_fun1_t(S (T::*p)(A) const);
-    S operator()(const T* p, A x) const;
-};
-
-template <class S, class T>          const_mem_fun_t<S,T>    mem_fun(S (T::*f)() const);      // deprecated in C++11, removed in C++17
-template <class S, class T, class A> const_mem_fun1_t<S,T,A> mem_fun(S (T::*f)(A) const);     // deprecated in C++11, removed in C++17
-
-template <class S, class T>
-class const_mem_fun_ref_t : public unary_function<T, S>      // deprecated in C++11, removed in C++17
-{
-public:
-    explicit const_mem_fun_ref_t(S (T::*p)() const);
-    S operator()(const T& p) const;
-};
-
-template <class S, class T, class A>
-class const_mem_fun1_ref_t : public binary_function<T, A, S>      // deprecated in C++11, removed in C++17
-{
-public:
-    explicit const_mem_fun1_ref_t(S (T::*p)(A) const);
-    S operator()(const T& p, A x) const;
-};
-
-template <class S, class T>          const_mem_fun_ref_t<S,T>    mem_fun_ref(S (T::*f)() const);   // deprecated in C++11, removed in C++17
-template <class S, class T, class A> const_mem_fun1_ref_t<S,T,A> mem_fun_ref(S (T::*f)(A) const);  // deprecated in C++11, removed in C++17
-
-template<class R, class T> unspecified mem_fn(R T::*);
-
-class bad_function_call
-    : public exception
-{
-};
-
-template<class> class function; // undefined
-
-template<class R, class... ArgTypes>
-class function<R(ArgTypes...)>
-  : public unary_function<T1, R>      // iff sizeof...(ArgTypes) == 1 and
-                                      // ArgTypes contains T1
-  : public binary_function<T1, T2, R> // iff sizeof...(ArgTypes) == 2 and
-                                      // ArgTypes contains T1 and T2
-{
-public:
-    typedef R result_type;
-
-    // construct/copy/destroy:
-    function() noexcept;
-    function(nullptr_t) noexcept;
-    function(const function&);
-    function(function&&) noexcept;
-    template<class F>
-      function(F);
-    template<Allocator Alloc>
-      function(allocator_arg_t, const Alloc&) noexcept;            // removed in C++17
-    template<Allocator Alloc>
-      function(allocator_arg_t, const Alloc&, nullptr_t) noexcept; // removed in C++17
-    template<Allocator Alloc>
-      function(allocator_arg_t, const Alloc&, const function&);    // removed in C++17
-    template<Allocator Alloc>
-      function(allocator_arg_t, const Alloc&, function&&);         // removed in C++17
-    template<class F, Allocator Alloc>
-      function(allocator_arg_t, const Alloc&, F);                  // removed in C++17
-
-    function& operator=(const function&);
-    function& operator=(function&&) noexcept;
-    function& operator=(nullptr_t) noexcept;
-    template<class F>
-      function& operator=(F&&);
-    template<class F>
-      function& operator=(reference_wrapper<F>) noexcept;
-
-    ~function();
-
-    // function modifiers:
-    void swap(function&) noexcept;
-    template<class F, class Alloc>
-      void assign(F&&, const Alloc&);                 // Removed in C++17
-
-    // function capacity:
-    explicit operator bool() const noexcept;
-
-    // function invocation:
-    R operator()(ArgTypes...) const;
-
-    // function target access:
-    const std::type_info& target_type() const noexcept;
-    template <typename T>       T* target() noexcept;
-    template <typename T> const T* target() const noexcept;
-};
-
-// Null pointer comparisons:
-template <class R, class ... ArgTypes>
-  bool operator==(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
-
-template <class R, class ... ArgTypes>
-  bool operator==(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
-
-template <class R, class ... ArgTypes>
-  bool operator!=(const function<R(ArgTypes...)>&, nullptr_t) noexcept;
-
-template <class  R, class ... ArgTypes>
-  bool operator!=(nullptr_t, const function<R(ArgTypes...)>&) noexcept;
-
-// specialized algorithms:
-template <class  R, class ... ArgTypes>
-  void swap(function<R(ArgTypes...)>&, function<R(ArgTypes...)>&) noexcept;
-
-template <class T> struct hash;
-
-template <> struct hash<bool>;
-template <> struct hash<char>;
-template <> struct hash<signed char>;
-template <> struct hash<unsigned char>;
-template <> struct hash<char16_t>;
-template <> struct hash<char32_t>;
-template <> struct hash<wchar_t>;
-template <> struct hash<short>;
-template <> struct hash<unsigned short>;
-template <> struct hash<int>;
-template <> struct hash<unsigned int>;
-template <> struct hash<long>;
-template <> struct hash<long long>;
-template <> struct hash<unsigned long>;
-template <> struct hash<unsigned long long>;
-
-template <> struct hash<float>;
-template <> struct hash<double>;
-template <> struct hash<long double>;
-
-template<class T> struct hash<T*>;
-template <> struct hash<nullptr_t>;  // C++17
-
-}  // std
-
-POLICY:  For non-variadic implementations, the number of arguments is limited
-         to 3.  It is hoped that the need for non-variadic implementations
-         will be minimal.
-
-*/
-
-#include <__config>
-#include <type_traits>
-#include <typeinfo>
-#include <exception>
-#include <memory>
-#include <tuple>
-#include <utility>
-#include <version>
-
-#include <__functional_base>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS plus : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x + __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS plus<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS minus : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x - __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS minus<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) - _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS multiplies : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x * __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS multiplies<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) * _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS divides : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x / __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS divides<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) / _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS modulus : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x % __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS modulus<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) % _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS negate : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return -__x;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS negate<void>
-{
-    template <class _Tp>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_Tp&& __x) const
-    _NOEXCEPT_(noexcept(- _VSTD::forward<_Tp>(__x)))
-    -> decltype        (- _VSTD::forward<_Tp>(__x))
-        { return        - _VSTD::forward<_Tp>(__x); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS equal_to : binary_function<_Tp, _Tp, bool>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x == __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS equal_to<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) == _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS not_equal_to : binary_function<_Tp, _Tp, bool>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x != __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS not_equal_to<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) != _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS greater : binary_function<_Tp, _Tp, bool>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x > __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS greater<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) > _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-// less in <__functional_base>
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS greater_equal : binary_function<_Tp, _Tp, bool>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x >= __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS greater_equal<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) >= _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS less_equal : binary_function<_Tp, _Tp, bool>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x <= __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS less_equal<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) <= _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS logical_and : binary_function<_Tp, _Tp, bool>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x && __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS logical_and<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) && _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS logical_or : binary_function<_Tp, _Tp, bool>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x || __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS logical_or<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) || _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS logical_not : unary_function<_Tp, bool>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Tp& __x) const
-        {return !__x;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS logical_not<void>
-{
-    template <class _Tp>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_Tp&& __x) const
-    _NOEXCEPT_(noexcept(!_VSTD::forward<_Tp>(__x)))
-    -> decltype        (!_VSTD::forward<_Tp>(__x))
-        { return        !_VSTD::forward<_Tp>(__x); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS bit_and : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x & __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS bit_and<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) & _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS bit_or : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x | __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS bit_or<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) | _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-#else
-template <class _Tp>
-#endif
-struct _LIBCPP_TEMPLATE_VIS bit_xor : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x ^ __y;}
-};
-
-#if _LIBCPP_STD_VER > 11
-template <>
-struct _LIBCPP_TEMPLATE_VIS bit_xor<void>
-{
-    template <class _T1, class _T2>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_T1&& __t, _T2&& __u) const
-    _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u)))
-    -> decltype        (_VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u))
-        { return        _VSTD::forward<_T1>(__t) ^ _VSTD::forward<_T2>(__u); }
-    typedef void is_transparent;
-};
-#endif
-
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp = void>
-struct _LIBCPP_TEMPLATE_VIS bit_not : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return ~__x;}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS bit_not<void>
-{
-    template <class _Tp>
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_Tp&& __x) const
-    _NOEXCEPT_(noexcept(~_VSTD::forward<_Tp>(__x)))
-    -> decltype        (~_VSTD::forward<_Tp>(__x))
-        { return        ~_VSTD::forward<_Tp>(__x); }
-    typedef void is_transparent;
-};
-#endif
-
-template <class _Predicate>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 unary_negate
-    : public unary_function<typename _Predicate::argument_type, bool>
-{
-    _Predicate __pred_;
-public:
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    explicit unary_negate(const _Predicate& __pred)
-        : __pred_(__pred) {}
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const typename _Predicate::argument_type& __x) const
-        {return !__pred_(__x);}
-};
-
-template <class _Predicate>
-_LIBCPP_DEPRECATED_IN_CXX17 inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-unary_negate<_Predicate>
-not1(const _Predicate& __pred) {return unary_negate<_Predicate>(__pred);}
-
-template <class _Predicate>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 binary_negate
-    : public binary_function<typename _Predicate::first_argument_type,
-                             typename _Predicate::second_argument_type,
-                             bool>
-{
-    _Predicate __pred_;
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit _LIBCPP_CONSTEXPR_AFTER_CXX11
-    binary_negate(const _Predicate& __pred) : __pred_(__pred) {}
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const typename _Predicate::first_argument_type& __x,
-                    const typename _Predicate::second_argument_type& __y) const
-        {return !__pred_(__x, __y);}
-};
-
-template <class _Predicate>
-_LIBCPP_DEPRECATED_IN_CXX17 inline _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-binary_negate<_Predicate>
-not2(const _Predicate& __pred) {return binary_negate<_Predicate>(__pred);}
-
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_BINDERS)
-template <class __Operation>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 binder1st
-    : public unary_function<typename __Operation::second_argument_type,
-                            typename __Operation::result_type>
-{
-protected:
-    __Operation                               op;
-    typename __Operation::first_argument_type value;
-public:
-    _LIBCPP_INLINE_VISIBILITY binder1st(const __Operation& __x,
-                               const typename __Operation::first_argument_type __y)
-        : op(__x), value(__y) {}
-    _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
-        (typename __Operation::second_argument_type& __x) const
-            {return op(value, __x);}
-    _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
-        (const typename __Operation::second_argument_type& __x) const
-            {return op(value, __x);}
-};
-
-template <class __Operation, class _Tp>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-binder1st<__Operation>
-bind1st(const __Operation& __op, const _Tp& __x)
-    {return binder1st<__Operation>(__op, __x);}
-
-template <class __Operation>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 binder2nd
-    : public unary_function<typename __Operation::first_argument_type,
-                            typename __Operation::result_type>
-{
-protected:
-    __Operation                                op;
-    typename __Operation::second_argument_type value;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    binder2nd(const __Operation& __x, const typename __Operation::second_argument_type __y)
-        : op(__x), value(__y) {}
-    _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
-        (      typename __Operation::first_argument_type& __x) const
-            {return op(__x, value);}
-    _LIBCPP_INLINE_VISIBILITY typename __Operation::result_type operator()
-        (const typename __Operation::first_argument_type& __x) const
-            {return op(__x, value);}
-};
-
-template <class __Operation, class _Tp>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-binder2nd<__Operation>
-bind2nd(const __Operation& __op, const _Tp& __x)
-    {return binder2nd<__Operation>(__op, __x);}
-
-template <class _Arg, class _Result>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 pointer_to_unary_function
-    : public unary_function<_Arg, _Result>
-{
-    _Result (*__f_)(_Arg);
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit pointer_to_unary_function(_Result (*__f)(_Arg))
-        : __f_(__f) {}
-    _LIBCPP_INLINE_VISIBILITY _Result operator()(_Arg __x) const
-        {return __f_(__x);}
-};
-
-template <class _Arg, class _Result>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-pointer_to_unary_function<_Arg,_Result>
-ptr_fun(_Result (*__f)(_Arg))
-    {return pointer_to_unary_function<_Arg,_Result>(__f);}
-
-template <class _Arg1, class _Arg2, class _Result>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 pointer_to_binary_function
-    : public binary_function<_Arg1, _Arg2, _Result>
-{
-    _Result (*__f_)(_Arg1, _Arg2);
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit pointer_to_binary_function(_Result (*__f)(_Arg1, _Arg2))
-        : __f_(__f) {}
-    _LIBCPP_INLINE_VISIBILITY _Result operator()(_Arg1 __x, _Arg2 __y) const
-        {return __f_(__x, __y);}
-};
-
-template <class _Arg1, class _Arg2, class _Result>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-pointer_to_binary_function<_Arg1,_Arg2,_Result>
-ptr_fun(_Result (*__f)(_Arg1,_Arg2))
-    {return pointer_to_binary_function<_Arg1,_Arg2,_Result>(__f);}
-
-template<class _Sp, class _Tp>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 mem_fun_t
-    : public unary_function<_Tp*, _Sp>
-{
-    _Sp (_Tp::*__p_)();
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit mem_fun_t(_Sp (_Tp::*__p)())
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp* __p) const
-        {return (__p->*__p_)();}
-};
-
-template<class _Sp, class _Tp, class _Ap>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 mem_fun1_t
-    : public binary_function<_Tp*, _Ap, _Sp>
-{
-    _Sp (_Tp::*__p_)(_Ap);
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit mem_fun1_t(_Sp (_Tp::*__p)(_Ap))
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp* __p, _Ap __x) const
-        {return (__p->*__p_)(__x);}
-};
-
-template<class _Sp, class _Tp>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-mem_fun_t<_Sp,_Tp>
-mem_fun(_Sp (_Tp::*__f)())
-    {return mem_fun_t<_Sp,_Tp>(__f);}
-
-template<class _Sp, class _Tp, class _Ap>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-mem_fun1_t<_Sp,_Tp,_Ap>
-mem_fun(_Sp (_Tp::*__f)(_Ap))
-    {return mem_fun1_t<_Sp,_Tp,_Ap>(__f);}
-
-template<class _Sp, class _Tp>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 mem_fun_ref_t
-    : public unary_function<_Tp, _Sp>
-{
-    _Sp (_Tp::*__p_)();
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit mem_fun_ref_t(_Sp (_Tp::*__p)())
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp& __p) const
-        {return (__p.*__p_)();}
-};
-
-template<class _Sp, class _Tp, class _Ap>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 mem_fun1_ref_t
-    : public binary_function<_Tp, _Ap, _Sp>
-{
-    _Sp (_Tp::*__p_)(_Ap);
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit mem_fun1_ref_t(_Sp (_Tp::*__p)(_Ap))
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY _Sp operator()(_Tp& __p, _Ap __x) const
-        {return (__p.*__p_)(__x);}
-};
-
-template<class _Sp, class _Tp>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-mem_fun_ref_t<_Sp,_Tp>
-mem_fun_ref(_Sp (_Tp::*__f)())
-    {return mem_fun_ref_t<_Sp,_Tp>(__f);}
-
-template<class _Sp, class _Tp, class _Ap>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-mem_fun1_ref_t<_Sp,_Tp,_Ap>
-mem_fun_ref(_Sp (_Tp::*__f)(_Ap))
-    {return mem_fun1_ref_t<_Sp,_Tp,_Ap>(__f);}
-
-template <class _Sp, class _Tp>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 const_mem_fun_t
-    : public unary_function<const _Tp*, _Sp>
-{
-    _Sp (_Tp::*__p_)() const;
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun_t(_Sp (_Tp::*__p)() const)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp* __p) const
-        {return (__p->*__p_)();}
-};
-
-template <class _Sp, class _Tp, class _Ap>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 const_mem_fun1_t
-    : public binary_function<const _Tp*, _Ap, _Sp>
-{
-    _Sp (_Tp::*__p_)(_Ap) const;
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun1_t(_Sp (_Tp::*__p)(_Ap) const)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp* __p, _Ap __x) const
-        {return (__p->*__p_)(__x);}
-};
-
-template <class _Sp, class _Tp>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-const_mem_fun_t<_Sp,_Tp>
-mem_fun(_Sp (_Tp::*__f)() const)
-    {return const_mem_fun_t<_Sp,_Tp>(__f);}
-
-template <class _Sp, class _Tp, class _Ap>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-const_mem_fun1_t<_Sp,_Tp,_Ap>
-mem_fun(_Sp (_Tp::*__f)(_Ap) const)
-    {return const_mem_fun1_t<_Sp,_Tp,_Ap>(__f);}
-
-template <class _Sp, class _Tp>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 const_mem_fun_ref_t
-    : public unary_function<_Tp, _Sp>
-{
-    _Sp (_Tp::*__p_)() const;
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun_ref_t(_Sp (_Tp::*__p)() const)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp& __p) const
-        {return (__p.*__p_)();}
-};
-
-template <class _Sp, class _Tp, class _Ap>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 const_mem_fun1_ref_t
-    : public binary_function<_Tp, _Ap, _Sp>
-{
-    _Sp (_Tp::*__p_)(_Ap) const;
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit const_mem_fun1_ref_t(_Sp (_Tp::*__p)(_Ap) const)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY _Sp operator()(const _Tp& __p, _Ap __x) const
-        {return (__p.*__p_)(__x);}
-};
-
-template <class _Sp, class _Tp>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-const_mem_fun_ref_t<_Sp,_Tp>
-mem_fun_ref(_Sp (_Tp::*__f)() const)
-    {return const_mem_fun_ref_t<_Sp,_Tp>(__f);}
-
-template <class _Sp, class _Tp, class _Ap>
-_LIBCPP_DEPRECATED_IN_CXX11 inline _LIBCPP_INLINE_VISIBILITY
-const_mem_fun1_ref_t<_Sp,_Tp,_Ap>
-mem_fun_ref(_Sp (_Tp::*__f)(_Ap) const)
-    {return const_mem_fun1_ref_t<_Sp,_Tp,_Ap>(__f);}
-#endif
-
-////////////////////////////////////////////////////////////////////////////////
-//                                MEMFUN
-//==============================================================================
-
-template <class _Tp>
-class __mem_fn
-    : public __weak_result_type<_Tp>
-{
-public:
-    // types
-    typedef _Tp type;
-private:
-    type __f_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY __mem_fn(type __f) _NOEXCEPT : __f_(__f) {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    // invoke
-    template <class... _ArgTypes>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return<type, _ArgTypes...>::type
-    operator() (_ArgTypes&&... __args) const {
-        return __invoke(__f_, _VSTD::forward<_ArgTypes>(__args)...);
-    }
-#else
-
-    template <class _A0>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return0<type, _A0>::type
-    operator() (_A0& __a0) const {
-        return __invoke(__f_, __a0);
-    }
-
-    template <class _A0>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return0<type, _A0 const>::type
-    operator() (_A0 const& __a0) const {
-        return __invoke(__f_, __a0);
-    }
-
-    template <class _A0, class _A1>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return1<type, _A0, _A1>::type
-    operator() (_A0& __a0, _A1& __a1) const {
-        return __invoke(__f_, __a0, __a1);
-    }
-
-    template <class _A0, class _A1>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return1<type, _A0 const, _A1>::type
-    operator() (_A0 const& __a0, _A1& __a1) const {
-        return __invoke(__f_, __a0, __a1);
-    }
-
-    template <class _A0, class _A1>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return1<type, _A0, _A1 const>::type
-    operator() (_A0& __a0, _A1 const& __a1) const {
-        return __invoke(__f_, __a0, __a1);
-    }
-
-    template <class _A0, class _A1>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return1<type, _A0 const, _A1 const>::type
-    operator() (_A0 const& __a0, _A1 const& __a1) const {
-        return __invoke(__f_, __a0, __a1);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0, _A1, _A2>::type
-    operator() (_A0& __a0, _A1& __a1, _A2& __a2) const {
-        return __invoke(__f_, __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0 const, _A1, _A2>::type
-    operator() (_A0 const& __a0, _A1& __a1, _A2& __a2) const {
-        return __invoke(__f_, __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0, _A1 const, _A2>::type
-    operator() (_A0& __a0, _A1 const& __a1, _A2& __a2) const {
-        return __invoke(__f_, __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0, _A1, _A2 const>::type
-    operator() (_A0& __a0, _A1& __a1, _A2 const& __a2) const {
-        return __invoke(__f_, __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0 const, _A1 const, _A2>::type
-    operator() (_A0 const& __a0, _A1 const& __a1, _A2& __a2) const {
-        return __invoke(__f_, __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0 const, _A1, _A2 const>::type
-    operator() (_A0 const& __a0, _A1& __a1, _A2 const& __a2) const {
-        return __invoke(__f_, __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0, _A1 const, _A2 const>::type
-    operator() (_A0& __a0, _A1 const& __a1, _A2 const& __a2) const {
-        return __invoke(__f_, __a0, __a1, __a2);
-    }
-
-    template <class _A0, class _A1, class _A2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename __invoke_return2<type, _A0 const, _A1 const, _A2 const>::type
-    operator() (_A0 const& __a0, _A1 const& __a1, _A2 const& __a2) const {
-        return __invoke(__f_, __a0, __a1, __a2);
-    }
-#endif
-};
-
-template<class _Rp, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__mem_fn<_Rp _Tp::*>
-mem_fn(_Rp _Tp::* __pm) _NOEXCEPT
-{
-    return __mem_fn<_Rp _Tp::*>(__pm);
-}
-
-////////////////////////////////////////////////////////////////////////////////
-//                                FUNCTION
-//==============================================================================
-
-// bad_function_call
-
-class _LIBCPP_EXCEPTION_ABI bad_function_call
-    : public exception
-{
-#ifdef _LIBCPP_ABI_BAD_FUNCTION_CALL_KEY_FUNCTION
-public:
-    virtual ~bad_function_call() _NOEXCEPT;
-
-    virtual const char* what() const _NOEXCEPT;
-#endif
-};
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_bad_function_call()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw bad_function_call();
-#else
-    _VSTD::abort();
-#endif
-}
-
-template<class _Fp> class _LIBCPP_TEMPLATE_VIS function; // undefined
-
-namespace __function
-{
-
-template<class _Rp>
-struct __maybe_derive_from_unary_function
-{
-};
-
-template<class _Rp, class _A1>
-struct __maybe_derive_from_unary_function<_Rp(_A1)>
-    : public unary_function<_A1, _Rp>
-{
-};
-
-template<class _Rp>
-struct __maybe_derive_from_binary_function
-{
-};
-
-template<class _Rp, class _A1, class _A2>
-struct __maybe_derive_from_binary_function<_Rp(_A1, _A2)>
-    : public binary_function<_A1, _A2, _Rp>
-{
-};
-
-template <class _Fp>
-_LIBCPP_INLINE_VISIBILITY
-bool __not_null(_Fp const&) { return true; }
-
-template <class _Fp>
-_LIBCPP_INLINE_VISIBILITY
-bool __not_null(_Fp* __ptr) { return __ptr; }
-
-template <class _Ret, class _Class>
-_LIBCPP_INLINE_VISIBILITY
-bool __not_null(_Ret _Class::*__ptr) { return __ptr; }
-
-template <class _Fp>
-_LIBCPP_INLINE_VISIBILITY
-bool __not_null(function<_Fp> const& __f) { return !!__f; }
-
-} // namespace __function
-
-#ifndef _LIBCPP_CXX03_LANG
-
-namespace __function {
-
-// __alloc_func holds a functor and an allocator.
-
-template <class _Fp, class _Ap, class _FB> class __alloc_func;
-
-template <class _Fp, class _Ap, class _Rp, class... _ArgTypes>
-class __alloc_func<_Fp, _Ap, _Rp(_ArgTypes...)>
-{
-    __compressed_pair<_Fp, _Ap> __f_;
-
-  public:
-    typedef _Fp _Target;
-    typedef _Ap _Alloc;
-
-    _LIBCPP_INLINE_VISIBILITY
-    const _Target& __target() const { return __f_.first(); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const _Alloc& __allocator() const { return __f_.second(); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __alloc_func(_Target&& __f)
-        : __f_(piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__f)),
-               _VSTD::forward_as_tuple())
-    {
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __alloc_func(const _Target& __f, const _Alloc& __a)
-        : __f_(piecewise_construct, _VSTD::forward_as_tuple(__f),
-               _VSTD::forward_as_tuple(__a))
-    {
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __alloc_func(const _Target& __f, _Alloc&& __a)
-        : __f_(piecewise_construct, _VSTD::forward_as_tuple(__f),
-               _VSTD::forward_as_tuple(_VSTD::move(__a)))
-    {
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __alloc_func(_Target&& __f, _Alloc&& __a)
-        : __f_(piecewise_construct, _VSTD::forward_as_tuple(_VSTD::move(__f)),
-               _VSTD::forward_as_tuple(_VSTD::move(__a)))
-    {
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Rp operator()(_ArgTypes&&... __arg)
-    {
-        typedef __invoke_void_return_wrapper<_Rp> _Invoker;
-        return _Invoker::__call(__f_.first(),
-                                _VSTD::forward<_ArgTypes>(__arg)...);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __alloc_func* __clone() const
-    {
-        typedef allocator_traits<_Alloc> __alloc_traits;
-        typedef
-            typename __rebind_alloc_helper<__alloc_traits, __alloc_func>::type
-                _AA;
-        _AA __a(__f_.second());
-        typedef __allocator_destructor<_AA> _Dp;
-        unique_ptr<__alloc_func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-        ::new ((void*)__hold.get()) __alloc_func(__f_.first(), _Alloc(__a));
-        return __hold.release();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void destroy() _NOEXCEPT { __f_.~__compressed_pair<_Target, _Alloc>(); }
-};
-
-// __base provides an abstract interface for copyable functors.
-
-template<class _Fp> class __base;
-
-template<class _Rp, class ..._ArgTypes>
-class __base<_Rp(_ArgTypes...)>
-{
-    __base(const __base&);
-    __base& operator=(const __base&);
-public:
-    _LIBCPP_INLINE_VISIBILITY __base() {}
-    _LIBCPP_INLINE_VISIBILITY virtual ~__base() {}
-    virtual __base* __clone() const = 0;
-    virtual void __clone(__base*) const = 0;
-    virtual void destroy() _NOEXCEPT = 0;
-    virtual void destroy_deallocate() _NOEXCEPT = 0;
-    virtual _Rp operator()(_ArgTypes&& ...) = 0;
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const _NOEXCEPT = 0;
-    virtual const std::type_info& target_type() const _NOEXCEPT = 0;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-// __func implements __base for a given functor type.
-
-template<class _FD, class _Alloc, class _FB> class __func;
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-class __func<_Fp, _Alloc, _Rp(_ArgTypes...)>
-    : public  __base<_Rp(_ArgTypes...)>
-{
-    __alloc_func<_Fp, _Alloc, _Rp(_ArgTypes...)> __f_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __func(_Fp&& __f)
-        : __f_(_VSTD::move(__f)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __func(const _Fp& __f, const _Alloc& __a)
-        : __f_(__f, __a) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __func(const _Fp& __f, _Alloc&& __a)
-        : __f_(__f, _VSTD::move(__a)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __func(_Fp&& __f, _Alloc&& __a)
-        : __f_(_VSTD::move(__f), _VSTD::move(__a)) {}
-
-    virtual __base<_Rp(_ArgTypes...)>* __clone() const;
-    virtual void __clone(__base<_Rp(_ArgTypes...)>*) const;
-    virtual void destroy() _NOEXCEPT;
-    virtual void destroy_deallocate() _NOEXCEPT;
-    virtual _Rp operator()(_ArgTypes&&... __arg);
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* target(const type_info&) const _NOEXCEPT;
-    virtual const std::type_info& target_type() const _NOEXCEPT;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-__base<_Rp(_ArgTypes...)>*
-__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__clone() const
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.__allocator());
-    typedef __allocator_destructor<_Ap> _Dp;
-    unique_ptr<__func, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-    ::new ((void*)__hold.get()) __func(__f_.__target(), _Alloc(__a));
-    return __hold.release();
-}
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-void
-__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__clone(__base<_Rp(_ArgTypes...)>* __p) const
-{
-    ::new (__p) __func(__f_.__target(), __f_.__allocator());
-}
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-void
-__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy() _NOEXCEPT
-{
-    __f_.destroy();
-}
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-void
-__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy_deallocate() _NOEXCEPT
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __func>::type _Ap;
-    _Ap __a(__f_.__allocator());
-    __f_.destroy();
-    __a.deallocate(this, 1);
-}
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-_Rp
-__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::operator()(_ArgTypes&& ... __arg)
-{
-    return __f_(_VSTD::forward<_ArgTypes>(__arg)...);
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-const void*
-__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::target(const type_info& __ti) const _NOEXCEPT
-{
-    if (__ti == typeid(_Fp))
-        return &__f_.__target();
-    return (const void*)0;
-}
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-const std::type_info&
-__func<_Fp, _Alloc, _Rp(_ArgTypes...)>::target_type() const _NOEXCEPT
-{
-    return typeid(_Fp);
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-// __value_func creates a value-type from a __func.
-
-template <class _Fp> class __value_func;
-
-template <class _Rp, class... _ArgTypes> class __value_func<_Rp(_ArgTypes...)>
-{
-    typename aligned_storage<3 * sizeof(void*)>::type __buf_;
-
-    typedef __base<_Rp(_ArgTypes...)> __func;
-    __func* __f_;
-
-    _LIBCPP_NO_CFI static __func* __as_base(void* p)
-    {
-        return reinterpret_cast<__func*>(p);
-    }
-
-  public:
-    _LIBCPP_INLINE_VISIBILITY
-    __value_func() _NOEXCEPT : __f_(0) {}
-
-    template <class _Fp, class _Alloc>
-    _LIBCPP_INLINE_VISIBILITY __value_func(_Fp&& __f, const _Alloc __a)
-        : __f_(0)
-    {
-        typedef allocator_traits<_Alloc> __alloc_traits;
-        typedef __function::__func<_Fp, _Alloc, _Rp(_ArgTypes...)> _Fun;
-        typedef typename __rebind_alloc_helper<__alloc_traits, _Fun>::type
-            _FunAlloc;
-
-        if (__function::__not_null(__f))
-        {
-            _FunAlloc __af(__a);
-            if (sizeof(_Fun) <= sizeof(__buf_) &&
-                is_nothrow_copy_constructible<_Fp>::value &&
-                is_nothrow_copy_constructible<_FunAlloc>::value)
-            {
-                __f_ =
-                    ::new ((void*)&__buf_) _Fun(_VSTD::move(__f), _Alloc(__af));
-            }
-            else
-            {
-                typedef __allocator_destructor<_FunAlloc> _Dp;
-                unique_ptr<__func, _Dp> __hold(__af.allocate(1), _Dp(__af, 1));
-                ::new ((void*)__hold.get()) _Fun(_VSTD::move(__f), _Alloc(__a));
-                __f_ = __hold.release();
-            }
-        }
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __value_func(const __value_func& __f)
-    {
-        if (__f.__f_ == 0)
-            __f_ = 0;
-        else if ((void*)__f.__f_ == &__f.__buf_)
-        {
-            __f_ = __as_base(&__buf_);
-            __f.__f_->__clone(__f_);
-        }
-        else
-            __f_ = __f.__f_->__clone();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __value_func(__value_func&& __f) _NOEXCEPT
-    {
-        if (__f.__f_ == 0)
-            __f_ = 0;
-        else if ((void*)__f.__f_ == &__f.__buf_)
-        {
-            __f_ = __as_base(&__buf_);
-            __f.__f_->__clone(__f_);
-        }
-        else
-        {
-            __f_ = __f.__f_;
-            __f.__f_ = 0;
-        }
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__value_func()
-    {
-        if ((void*)__f_ == &__buf_)
-            __f_->destroy();
-        else if (__f_)
-            __f_->destroy_deallocate();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __value_func& operator=(__value_func&& __f)
-    {
-        *this = nullptr;
-        if (__f.__f_ == 0)
-            __f_ = 0;
-        else if ((void*)__f.__f_ == &__f.__buf_)
-        {
-            __f_ = __as_base(&__buf_);
-            __f.__f_->__clone(__f_);
-        }
-        else
-        {
-            __f_ = __f.__f_;
-            __f.__f_ = 0;
-        }
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __value_func& operator=(nullptr_t)
-    {
-        __func* __f = __f_;
-        __f_ = 0;
-        if ((void*)__f == &__buf_)
-            __f->destroy();
-        else if (__f)
-            __f->destroy_deallocate();
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Rp operator()(_ArgTypes&&... __args) const
-    {
-        if (__f_ == 0)
-            __throw_bad_function_call();
-        return (*__f_)(_VSTD::forward<_ArgTypes>(__args)...);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(__value_func& __f) _NOEXCEPT
-    {
-        if (&__f == this)
-            return;
-        if ((void*)__f_ == &__buf_ && (void*)__f.__f_ == &__f.__buf_)
-        {
-            typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
-            __func* __t = __as_base(&__tempbuf);
-            __f_->__clone(__t);
-            __f_->destroy();
-            __f_ = 0;
-            __f.__f_->__clone(__as_base(&__buf_));
-            __f.__f_->destroy();
-            __f.__f_ = 0;
-            __f_ = __as_base(&__buf_);
-            __t->__clone(__as_base(&__f.__buf_));
-            __t->destroy();
-            __f.__f_ = __as_base(&__f.__buf_);
-        }
-        else if ((void*)__f_ == &__buf_)
-        {
-            __f_->__clone(__as_base(&__f.__buf_));
-            __f_->destroy();
-            __f_ = __f.__f_;
-            __f.__f_ = __as_base(&__f.__buf_);
-        }
-        else if ((void*)__f.__f_ == &__f.__buf_)
-        {
-            __f.__f_->__clone(__as_base(&__buf_));
-            __f.__f_->destroy();
-            __f.__f_ = __f_;
-            __f_ = __as_base(&__buf_);
-        }
-        else
-            _VSTD::swap(__f_, __f.__f_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT { return __f_ != 0; }
-
-#ifndef _LIBCPP_NO_RTTI
-    _LIBCPP_INLINE_VISIBILITY
-    const std::type_info& target_type() const _NOEXCEPT
-    {
-        if (__f_ == 0)
-            return typeid(void);
-        return __f_->target_type();
-    }
-
-    template <typename _Tp>
-    _LIBCPP_INLINE_VISIBILITY const _Tp* target() const _NOEXCEPT
-    {
-        if (__f_ == 0)
-            return 0;
-        return (const _Tp*)__f_->target(typeid(_Tp));
-    }
-#endif // _LIBCPP_NO_RTTI
-};
-
-// Storage for a functor object, to be used with __policy to manage copy and
-// destruction.
-union __policy_storage
-{
-    mutable char __small[sizeof(void*) * 2];
-    void* __large;
-};
-
-// True if _Fun can safely be held in __policy_storage.__small.
-template <typename _Fun>
-struct __use_small_storage
-    : public _VSTD::integral_constant<
-          bool, sizeof(_Fun) <= sizeof(__policy_storage) &&
-                    _LIBCPP_ALIGNOF(_Fun) <= _LIBCPP_ALIGNOF(__policy_storage) &&
-                    _VSTD::is_trivially_copy_constructible<_Fun>::value &&
-                    _VSTD::is_trivially_destructible<_Fun>::value> {};
-
-// Policy contains information about how to copy, destroy, and move the
-// underlying functor. You can think of it as a vtable of sorts.
-struct __policy
-{
-    // Used to copy or destroy __large values. null for trivial objects.
-    void* (*const __clone)(const void*);
-    void (*const __destroy)(void*);
-
-    // True if this is the null policy (no value).
-    const bool __is_null;
-
-    // The target type. May be null if RTTI is disabled.
-    const std::type_info* const __type_info;
-
-    // Returns a pointer to a static policy object suitable for the functor
-    // type.
-    template <typename _Fun>
-    _LIBCPP_INLINE_VISIBILITY static const __policy* __create()
-    {
-        return __choose_policy<_Fun>(__use_small_storage<_Fun>());
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static const __policy* __create_empty()
-    {
-        static const _LIBCPP_CONSTEXPR __policy __policy_ = {nullptr, nullptr,
-                                                             true,
-#ifndef _LIBCPP_NO_RTTI
-                                                             &typeid(void)
-#else
-                                                             nullptr
-#endif
-        };
-        return &__policy_;
-    }
-
-  private:
-    template <typename _Fun> static void* __large_clone(const void* __s)
-    {
-        const _Fun* __f = static_cast<const _Fun*>(__s);
-        return __f->__clone();
-    }
-
-    template <typename _Fun> static void __large_destroy(void* __s)
-    {
-        typedef allocator_traits<typename _Fun::_Alloc> __alloc_traits;
-        typedef typename __rebind_alloc_helper<__alloc_traits, _Fun>::type
-            _FunAlloc;
-        _Fun* __f = static_cast<_Fun*>(__s);
-        _FunAlloc __a(__f->__allocator());
-        __f->destroy();
-        __a.deallocate(__f, 1);
-    }
-
-    template <typename _Fun>
-    _LIBCPP_INLINE_VISIBILITY static const __policy*
-        __choose_policy(/* is_small = */ false_type)
-    {
-        static const _LIBCPP_CONSTEXPR __policy __policy_ = {
-            &__large_clone<_Fun>, &__large_destroy<_Fun>, false,
-#ifndef _LIBCPP_NO_RTTI
-            &typeid(typename _Fun::_Target)
-#else
-            nullptr
-#endif
-        };
-        return &__policy_;
-    }
-
-    template <typename _Fun>
-    _LIBCPP_INLINE_VISIBILITY static const __policy*
-        __choose_policy(/* is_small = */ true_type)
-    {
-        static const _LIBCPP_CONSTEXPR __policy __policy_ = {
-            nullptr, nullptr, false,
-#ifndef _LIBCPP_NO_RTTI
-            &typeid(typename _Fun::_Target)
-#else
-            nullptr
-#endif
-        };
-        return &__policy_;
-    }
-};
-
-// Used to choose between perfect forwarding or pass-by-value. Pass-by-value is
-// faster for types that can be passed in registers.
-template <typename _Tp>
-using __fast_forward =
-    typename _VSTD::conditional<_VSTD::is_scalar<_Tp>::value, _Tp, _Tp&&>::type;
-
-// __policy_invoker calls an instance of __alloc_func held in __policy_storage.
-
-template <class _Fp> struct __policy_invoker;
-
-template <class _Rp, class... _ArgTypes>
-struct __policy_invoker<_Rp(_ArgTypes...)>
-{
-    typedef _Rp (*__Call)(const __policy_storage*,
-                          __fast_forward<_ArgTypes>...);
-
-    __Call __call_;
-
-    // Creates an invoker that throws bad_function_call.
-    _LIBCPP_INLINE_VISIBILITY
-    __policy_invoker() : __call_(&__call_empty) {}
-
-    // Creates an invoker that calls the given instance of __func.
-    template <typename _Fun>
-    _LIBCPP_INLINE_VISIBILITY static __policy_invoker __create()
-    {
-        return __policy_invoker(&__call_impl<_Fun>);
-    }
-
-  private:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __policy_invoker(__Call __c) : __call_(__c) {}
-
-    static _Rp __call_empty(const __policy_storage*,
-                            __fast_forward<_ArgTypes>...)
-    {
-        __throw_bad_function_call();
-    }
-
-    template <typename _Fun>
-    static _Rp __call_impl(const __policy_storage* __buf,
-                           __fast_forward<_ArgTypes>... __args)
-    {
-        _Fun* __f = reinterpret_cast<_Fun*>(__use_small_storage<_Fun>::value
-                                                ? &__buf->__small
-                                                : __buf->__large);
-        return (*__f)(_VSTD::forward<_ArgTypes>(__args)...);
-    }
-};
-
-// __policy_func uses a __policy and __policy_invoker to create a type-erased,
-// copyable functor.
-
-template <class _Fp> class __policy_func;
-
-template <class _Rp, class... _ArgTypes> class __policy_func<_Rp(_ArgTypes...)>
-{
-    // Inline storage for small objects.
-    __policy_storage __buf_;
-
-    // Calls the value stored in __buf_. This could technically be part of
-    // policy, but storing it here eliminates a level of indirection inside
-    // operator().
-    typedef __function::__policy_invoker<_Rp(_ArgTypes...)> __invoker;
-    __invoker __invoker_;
-
-    // The policy that describes how to move / copy / destroy __buf_. Never
-    // null, even if the function is empty.
-    const __policy* __policy_;
-
-  public:
-    _LIBCPP_INLINE_VISIBILITY
-    __policy_func() : __policy_(__policy::__create_empty()) {}
-
-    template <class _Fp, class _Alloc>
-    _LIBCPP_INLINE_VISIBILITY __policy_func(_Fp&& __f, const _Alloc& __a)
-        : __policy_(__policy::__create_empty())
-    {
-        typedef __alloc_func<_Fp, _Alloc, _Rp(_ArgTypes...)> _Fun;
-        typedef allocator_traits<_Alloc> __alloc_traits;
-        typedef typename __rebind_alloc_helper<__alloc_traits, _Fun>::type
-            _FunAlloc;
-
-        if (__function::__not_null(__f))
-        {
-            __invoker_ = __invoker::template __create<_Fun>();
-            __policy_ = __policy::__create<_Fun>();
-
-            _FunAlloc __af(__a);
-            if (__use_small_storage<_Fun>())
-            {
-                ::new ((void*)&__buf_.__small)
-                    _Fun(_VSTD::move(__f), _Alloc(__af));
-            }
-            else
-            {
-                typedef __allocator_destructor<_FunAlloc> _Dp;
-                unique_ptr<_Fun, _Dp> __hold(__af.allocate(1), _Dp(__af, 1));
-                ::new ((void*)__hold.get())
-                    _Fun(_VSTD::move(__f), _Alloc(__af));
-                __buf_.__large = __hold.release();
-            }
-        }
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __policy_func(const __policy_func& __f)
-        : __buf_(__f.__buf_), __invoker_(__f.__invoker_),
-          __policy_(__f.__policy_)
-    {
-        if (__policy_->__clone)
-            __buf_.__large = __policy_->__clone(__f.__buf_.__large);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __policy_func(__policy_func&& __f)
-        : __buf_(__f.__buf_), __invoker_(__f.__invoker_),
-          __policy_(__f.__policy_)
-    {
-        if (__policy_->__destroy)
-        {
-            __f.__policy_ = __policy::__create_empty();
-            __f.__invoker_ = __invoker();
-        }
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__policy_func()
-    {
-        if (__policy_->__destroy)
-            __policy_->__destroy(__buf_.__large);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __policy_func& operator=(__policy_func&& __f)
-    {
-        *this = nullptr;
-        __buf_ = __f.__buf_;
-        __invoker_ = __f.__invoker_;
-        __policy_ = __f.__policy_;
-        __f.__policy_ = __policy::__create_empty();
-        __f.__invoker_ = __invoker();
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __policy_func& operator=(nullptr_t)
-    {
-        const __policy* __p = __policy_;
-        __policy_ = __policy::__create_empty();
-        __invoker_ = __invoker();
-        if (__p->__destroy)
-            __p->__destroy(__buf_.__large);
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Rp operator()(_ArgTypes&&... __args) const
-    {
-        return __invoker_.__call_(_VSTD::addressof(__buf_),
-                                  _VSTD::forward<_ArgTypes>(__args)...);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(__policy_func& __f)
-    {
-        _VSTD::swap(__invoker_, __f.__invoker_);
-        _VSTD::swap(__policy_, __f.__policy_);
-        _VSTD::swap(__buf_, __f.__buf_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit operator bool() const _NOEXCEPT
-    {
-        return !__policy_->__is_null;
-    }
-
-#ifndef _LIBCPP_NO_RTTI
-    _LIBCPP_INLINE_VISIBILITY
-    const std::type_info& target_type() const _NOEXCEPT
-    {
-        return *__policy_->__type_info;
-    }
-
-    template <typename _Tp>
-    _LIBCPP_INLINE_VISIBILITY const _Tp* target() const _NOEXCEPT
-    {
-        if (__policy_->__is_null || typeid(_Tp) != *__policy_->__type_info)
-            return nullptr;
-        if (__policy_->__clone) // Out of line storage.
-            return reinterpret_cast<const _Tp*>(__buf_.__large);
-        else
-            return reinterpret_cast<const _Tp*>(&__buf_.__small);
-    }
-#endif // _LIBCPP_NO_RTTI
-};
-
-}  // __function
-
-template<class _Rp, class ..._ArgTypes>
-class _LIBCPP_TEMPLATE_VIS function<_Rp(_ArgTypes...)>
-    : public __function::__maybe_derive_from_unary_function<_Rp(_ArgTypes...)>,
-      public __function::__maybe_derive_from_binary_function<_Rp(_ArgTypes...)>
-{
-#ifndef _LIBCPP_ABI_OPTIMIZED_FUNCTION
-    typedef __function::__value_func<_Rp(_ArgTypes...)> __func;
-#else
-    typedef __function::__policy_func<_Rp(_ArgTypes...)> __func;
-#endif
-
-    __func __f_;
-
-    template <class _Fp, bool = __lazy_and<
-        integral_constant<bool, !is_same<__uncvref_t<_Fp>, function>::value>,
-        __invokable<_Fp&, _ArgTypes...>
-    >::value>
-    struct __callable;
-    template <class _Fp>
-        struct __callable<_Fp, true>
-        {
-            static const bool value = is_same<void, _Rp>::value ||
-                is_convertible<typename __invoke_of<_Fp&, _ArgTypes...>::type,
-                               _Rp>::value;
-        };
-    template <class _Fp>
-        struct __callable<_Fp, false>
-        {
-            static const bool value = false;
-        };
-
-  template <class _Fp>
-  using _EnableIfCallable = typename enable_if<__callable<_Fp>::value>::type;
-public:
-    typedef _Rp result_type;
-
-    // construct/copy/destroy:
-    _LIBCPP_INLINE_VISIBILITY
-    function() _NOEXCEPT { }
-    _LIBCPP_INLINE_VISIBILITY
-    function(nullptr_t) _NOEXCEPT {}
-    function(const function&);
-    function(function&&) _NOEXCEPT;
-    template<class _Fp, class = _EnableIfCallable<_Fp>>
-    function(_Fp);
-
-#if _LIBCPP_STD_VER <= 14
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&) _NOEXCEPT {}
-    template<class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      function(allocator_arg_t, const _Alloc&, nullptr_t) _NOEXCEPT {}
-    template<class _Alloc>
-      function(allocator_arg_t, const _Alloc&, const function&);
-    template<class _Alloc>
-      function(allocator_arg_t, const _Alloc&, function&&);
-    template<class _Fp, class _Alloc, class = _EnableIfCallable<_Fp>>
-      function(allocator_arg_t, const _Alloc& __a, _Fp __f);
-#endif
-
-    function& operator=(const function&);
-    function& operator=(function&&) _NOEXCEPT;
-    function& operator=(nullptr_t) _NOEXCEPT;
-    template<class _Fp, class = _EnableIfCallable<_Fp>>
-    function& operator=(_Fp&&);
-
-    ~function();
-
-    // function modifiers:
-    void swap(function&) _NOEXCEPT;
-
-#if _LIBCPP_STD_VER <= 14
-    template<class _Fp, class _Alloc>
-      _LIBCPP_INLINE_VISIBILITY
-      void assign(_Fp&& __f, const _Alloc& __a)
-        {function(allocator_arg, __a, _VSTD::forward<_Fp>(__f)).swap(*this);}
-#endif
-
-    // function capacity:
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
-      return static_cast<bool>(__f_);
-    }
-
-    // deleted overloads close possible hole in the type system
-    template<class _R2, class... _ArgTypes2>
-      bool operator==(const function<_R2(_ArgTypes2...)>&) const = delete;
-    template<class _R2, class... _ArgTypes2>
-      bool operator!=(const function<_R2(_ArgTypes2...)>&) const = delete;
-public:
-    // function invocation:
-    _Rp operator()(_ArgTypes...) const;
-
-#ifndef _LIBCPP_NO_RTTI
-    // function target access:
-    const std::type_info& target_type() const _NOEXCEPT;
-    template <typename _Tp> _Tp* target() _NOEXCEPT;
-    template <typename _Tp> const _Tp* target() const _NOEXCEPT;
-#endif  // _LIBCPP_NO_RTTI
-};
-
-template<class _Rp, class ..._ArgTypes>
-function<_Rp(_ArgTypes...)>::function(const function& __f) : __f_(__f.__f_) {}
-
-#if _LIBCPP_STD_VER <= 14
-template<class _Rp, class ..._ArgTypes>
-template <class _Alloc>
-function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&,
-                                     const function& __f) : __f_(__f.__f_) {}
-#endif
-
-template <class _Rp, class... _ArgTypes>
-function<_Rp(_ArgTypes...)>::function(function&& __f) _NOEXCEPT
-    : __f_(_VSTD::move(__f.__f_)) {}
-
-#if _LIBCPP_STD_VER <= 14
-template<class _Rp, class ..._ArgTypes>
-template <class _Alloc>
-function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc&,
-                                      function&& __f)
-    : __f_(_VSTD::move(__f.__f_)) {}
-#endif
-
-template <class _Rp, class... _ArgTypes>
-template <class _Fp, class>
-function<_Rp(_ArgTypes...)>::function(_Fp __f)
-    : __f_(_VSTD::move(__f), allocator<_Fp>()) {}
-
-#if _LIBCPP_STD_VER <= 14
-template <class _Rp, class... _ArgTypes>
-template <class _Fp, class _Alloc, class>
-function<_Rp(_ArgTypes...)>::function(allocator_arg_t, const _Alloc& __a,
-                                      _Fp __f)
-    : __f_(_VSTD::move(__f), __a) {}
-#endif
-
-template<class _Rp, class ..._ArgTypes>
-function<_Rp(_ArgTypes...)>&
-function<_Rp(_ArgTypes...)>::operator=(const function& __f)
-{
-    function(__f).swap(*this);
-    return *this;
-}
-
-template<class _Rp, class ..._ArgTypes>
-function<_Rp(_ArgTypes...)>&
-function<_Rp(_ArgTypes...)>::operator=(function&& __f) _NOEXCEPT
-{
-    __f_ = std::move(__f.__f_);
-    return *this;
-}
-
-template<class _Rp, class ..._ArgTypes>
-function<_Rp(_ArgTypes...)>&
-function<_Rp(_ArgTypes...)>::operator=(nullptr_t) _NOEXCEPT
-{
-    __f_ = nullptr;
-    return *this;
-}
-
-template<class _Rp, class ..._ArgTypes>
-template <class _Fp, class>
-function<_Rp(_ArgTypes...)>&
-function<_Rp(_ArgTypes...)>::operator=(_Fp&& __f)
-{
-    function(_VSTD::forward<_Fp>(__f)).swap(*this);
-    return *this;
-}
-
-template<class _Rp, class ..._ArgTypes>
-function<_Rp(_ArgTypes...)>::~function() {}
-
-template<class _Rp, class ..._ArgTypes>
-void
-function<_Rp(_ArgTypes...)>::swap(function& __f) _NOEXCEPT
-{
-    __f_.swap(__f.__f_);
-}
-
-template<class _Rp, class ..._ArgTypes>
-_Rp
-function<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __arg) const
-{
-    return __f_(_VSTD::forward<_ArgTypes>(__arg)...);
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Rp, class ..._ArgTypes>
-const std::type_info&
-function<_Rp(_ArgTypes...)>::target_type() const _NOEXCEPT
-{
-    return __f_.target_type();
-}
-
-template<class _Rp, class ..._ArgTypes>
-template <typename _Tp>
-_Tp*
-function<_Rp(_ArgTypes...)>::target() _NOEXCEPT
-{
-    return (_Tp*)(__f_.template target<_Tp>());
-}
-
-template<class _Rp, class ..._ArgTypes>
-template <typename _Tp>
-const _Tp*
-function<_Rp(_ArgTypes...)>::target() const _NOEXCEPT
-{
-    return __f_.template target<_Tp>();
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template <class _Rp, class... _ArgTypes>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {return !__f;}
-
-template <class _Rp, class... _ArgTypes>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {return !__f;}
-
-template <class _Rp, class... _ArgTypes>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const function<_Rp(_ArgTypes...)>& __f, nullptr_t) _NOEXCEPT {return (bool)__f;}
-
-template <class _Rp, class... _ArgTypes>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(nullptr_t, const function<_Rp(_ArgTypes...)>& __f) _NOEXCEPT {return (bool)__f;}
-
-template <class _Rp, class... _ArgTypes>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(function<_Rp(_ArgTypes...)>& __x, function<_Rp(_ArgTypes...)>& __y) _NOEXCEPT
-{return __x.swap(__y);}
-
-#else // _LIBCPP_CXX03_LANG
-
-#include <__functional_03>
-
-#endif
-
-////////////////////////////////////////////////////////////////////////////////
-//                                  BIND
-//==============================================================================
-
-template<class _Tp> struct __is_bind_expression : public false_type {};
-template<class _Tp> struct _LIBCPP_TEMPLATE_VIS is_bind_expression
-    : public __is_bind_expression<typename remove_cv<_Tp>::type> {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr size_t is_bind_expression_v = is_bind_expression<_Tp>::value;
-#endif
-
-template<class _Tp> struct __is_placeholder : public integral_constant<int, 0> {};
-template<class _Tp> struct _LIBCPP_TEMPLATE_VIS is_placeholder
-    : public __is_placeholder<typename remove_cv<_Tp>::type> {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr size_t is_placeholder_v = is_placeholder<_Tp>::value;
-#endif
-
-namespace placeholders
-{
-
-template <int _Np> struct __ph {};
-
-#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
-_LIBCPP_FUNC_VIS extern const __ph<1>   _1;
-_LIBCPP_FUNC_VIS extern const __ph<2>   _2;
-_LIBCPP_FUNC_VIS extern const __ph<3>   _3;
-_LIBCPP_FUNC_VIS extern const __ph<4>   _4;
-_LIBCPP_FUNC_VIS extern const __ph<5>   _5;
-_LIBCPP_FUNC_VIS extern const __ph<6>   _6;
-_LIBCPP_FUNC_VIS extern const __ph<7>   _7;
-_LIBCPP_FUNC_VIS extern const __ph<8>   _8;
-_LIBCPP_FUNC_VIS extern const __ph<9>   _9;
-_LIBCPP_FUNC_VIS extern const __ph<10> _10;
-#else
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<1>   _1{};
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<2>   _2{};
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<3>   _3{};
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<4>   _4{};
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<5>   _5{};
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<6>   _6{};
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<7>   _7{};
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<8>   _8{};
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<9>   _9{};
-/* _LIBCPP_INLINE_VAR */ constexpr __ph<10> _10{};
-#endif // defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
-
-}  // placeholders
-
-template<int _Np>
-struct __is_placeholder<placeholders::__ph<_Np> >
-    : public integral_constant<int, _Np> {};
-
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Uj>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp&
-__mu(reference_wrapper<_Tp> __t, _Uj&)
-{
-    return __t.get();
-}
-
-template <class _Ti, class ..._Uj, size_t ..._Indx>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __invoke_of<_Ti&, _Uj...>::type
-__mu_expand(_Ti& __ti, tuple<_Uj...>& __uj, __tuple_indices<_Indx...>)
-{
-    return __ti(_VSTD::forward<_Uj>(_VSTD::get<_Indx>(__uj))...);
-}
-
-template <class _Ti, class ..._Uj>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __lazy_enable_if
-<
-    is_bind_expression<_Ti>::value,
-    __invoke_of<_Ti&, _Uj...>
->::type
-__mu(_Ti& __ti, tuple<_Uj...>& __uj)
-{
-    typedef typename __make_tuple_indices<sizeof...(_Uj)>::type __indices;
-    return  __mu_expand(__ti, __uj, __indices());
-}
-
-template <bool IsPh, class _Ti, class _Uj>
-struct __mu_return2 {};
-
-template <class _Ti, class _Uj>
-struct __mu_return2<true, _Ti, _Uj>
-{
-    typedef typename tuple_element<is_placeholder<_Ti>::value - 1, _Uj>::type type;
-};
-
-template <class _Ti, class _Uj>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    0 < is_placeholder<_Ti>::value,
-    typename __mu_return2<0 < is_placeholder<_Ti>::value, _Ti, _Uj>::type
->::type
-__mu(_Ti&, _Uj& __uj)
-{
-    const size_t _Indx = is_placeholder<_Ti>::value - 1;
-    return _VSTD::forward<typename tuple_element<_Indx, _Uj>::type>(_VSTD::get<_Indx>(__uj));
-}
-
-template <class _Ti, class _Uj>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    !is_bind_expression<_Ti>::value &&
-    is_placeholder<_Ti>::value == 0 &&
-    !__is_reference_wrapper<_Ti>::value,
-    _Ti&
->::type
-__mu(_Ti& __ti, _Uj&)
-{
-    return __ti;
-}
-
-template <class _Ti, bool IsReferenceWrapper, bool IsBindEx, bool IsPh,
-          class _TupleUj>
-struct __mu_return_impl;
-
-template <bool _Invokable, class _Ti, class ..._Uj>
-struct __mu_return_invokable  // false
-{
-    typedef __nat type;
-};
-
-template <class _Ti, class ..._Uj>
-struct __mu_return_invokable<true, _Ti, _Uj...>
-{
-    typedef typename __invoke_of<_Ti&, _Uj...>::type type;
-};
-
-template <class _Ti, class ..._Uj>
-struct __mu_return_impl<_Ti, false, true, false, tuple<_Uj...> >
-    : public __mu_return_invokable<__invokable<_Ti&, _Uj...>::value, _Ti, _Uj...>
-{
-};
-
-template <class _Ti, class _TupleUj>
-struct __mu_return_impl<_Ti, false, false, true, _TupleUj>
-{
-    typedef typename tuple_element<is_placeholder<_Ti>::value - 1,
-                                   _TupleUj>::type&& type;
-};
-
-template <class _Ti, class _TupleUj>
-struct __mu_return_impl<_Ti, true, false, false, _TupleUj>
-{
-    typedef typename _Ti::type& type;
-};
-
-template <class _Ti, class _TupleUj>
-struct __mu_return_impl<_Ti, false, false, false, _TupleUj>
-{
-    typedef _Ti& type;
-};
-
-template <class _Ti, class _TupleUj>
-struct __mu_return
-    : public __mu_return_impl<_Ti,
-                              __is_reference_wrapper<_Ti>::value,
-                              is_bind_expression<_Ti>::value,
-                              0 < is_placeholder<_Ti>::value &&
-                              is_placeholder<_Ti>::value <= tuple_size<_TupleUj>::value,
-                              _TupleUj>
-{
-};
-
-template <class _Fp, class _BoundArgs, class _TupleUj>
-struct __is_valid_bind_return
-{
-    static const bool value = false;
-};
-
-template <class _Fp, class ..._BoundArgs, class _TupleUj>
-struct __is_valid_bind_return<_Fp, tuple<_BoundArgs...>, _TupleUj>
-{
-    static const bool value = __invokable<_Fp,
-                    typename __mu_return<_BoundArgs, _TupleUj>::type...>::value;
-};
-
-template <class _Fp, class ..._BoundArgs, class _TupleUj>
-struct __is_valid_bind_return<_Fp, const tuple<_BoundArgs...>, _TupleUj>
-{
-    static const bool value = __invokable<_Fp,
-                    typename __mu_return<const _BoundArgs, _TupleUj>::type...>::value;
-};
-
-template <class _Fp, class _BoundArgs, class _TupleUj,
-          bool = __is_valid_bind_return<_Fp, _BoundArgs, _TupleUj>::value>
-struct __bind_return;
-
-template <class _Fp, class ..._BoundArgs, class _TupleUj>
-struct __bind_return<_Fp, tuple<_BoundArgs...>, _TupleUj, true>
-{
-    typedef typename __invoke_of
-    <
-        _Fp&,
-        typename __mu_return
-        <
-            _BoundArgs,
-            _TupleUj
-        >::type...
-    >::type type;
-};
-
-template <class _Fp, class ..._BoundArgs, class _TupleUj>
-struct __bind_return<_Fp, const tuple<_BoundArgs...>, _TupleUj, true>
-{
-    typedef typename __invoke_of
-    <
-        _Fp&,
-        typename __mu_return
-        <
-            const _BoundArgs,
-            _TupleUj
-        >::type...
-    >::type type;
-};
-
-template <class _Fp, class _BoundArgs, size_t ..._Indx, class _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __bind_return<_Fp, _BoundArgs, _Args>::type
-__apply_functor(_Fp& __f, _BoundArgs& __bound_args, __tuple_indices<_Indx...>,
-                _Args&& __args)
-{
-    return _VSTD::__invoke(__f, _VSTD::__mu(_VSTD::get<_Indx>(__bound_args), __args)...);
-}
-
-template<class _Fp, class ..._BoundArgs>
-class __bind
-    : public __weak_result_type<typename decay<_Fp>::type>
-{
-protected:
-    typedef typename decay<_Fp>::type _Fd;
-    typedef tuple<typename decay<_BoundArgs>::type...> _Td;
-private:
-    _Fd __f_;
-    _Td __bound_args_;
-
-    typedef typename __make_tuple_indices<sizeof...(_BoundArgs)>::type __indices;
-public:
-    template <class _Gp, class ..._BA,
-              class = typename enable_if
-                               <
-                                  is_constructible<_Fd, _Gp>::value &&
-                                  !is_same<typename remove_reference<_Gp>::type,
-                                           __bind>::value
-                               >::type>
-      _LIBCPP_INLINE_VISIBILITY
-      explicit __bind(_Gp&& __f, _BA&& ...__bound_args)
-        : __f_(_VSTD::forward<_Gp>(__f)),
-          __bound_args_(_VSTD::forward<_BA>(__bound_args)...) {}
-
-    template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY
-        typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type
-        operator()(_Args&& ...__args)
-        {
-            return _VSTD::__apply_functor(__f_, __bound_args_, __indices(),
-                                  tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
-        }
-
-    template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY
-        typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type
-        operator()(_Args&& ...__args) const
-        {
-            return _VSTD::__apply_functor(__f_, __bound_args_, __indices(),
-                                   tuple<_Args&&...>(_VSTD::forward<_Args>(__args)...));
-        }
-};
-
-template<class _Fp, class ..._BoundArgs>
-struct __is_bind_expression<__bind<_Fp, _BoundArgs...> > : public true_type {};
-
-template<class _Rp, class _Fp, class ..._BoundArgs>
-class __bind_r
-    : public __bind<_Fp, _BoundArgs...>
-{
-    typedef __bind<_Fp, _BoundArgs...> base;
-    typedef typename base::_Fd _Fd;
-    typedef typename base::_Td _Td;
-public:
-    typedef _Rp result_type;
-
-
-    template <class _Gp, class ..._BA,
-              class = typename enable_if
-                               <
-                                  is_constructible<_Fd, _Gp>::value &&
-                                  !is_same<typename remove_reference<_Gp>::type,
-                                           __bind_r>::value
-                               >::type>
-      _LIBCPP_INLINE_VISIBILITY
-      explicit __bind_r(_Gp&& __f, _BA&& ...__bound_args)
-        : base(_VSTD::forward<_Gp>(__f),
-               _VSTD::forward<_BA>(__bound_args)...) {}
-
-    template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            is_convertible<typename __bind_return<_Fd, _Td, tuple<_Args&&...> >::type,
-                           result_type>::value || is_void<_Rp>::value,
-            result_type
-        >::type
-        operator()(_Args&& ...__args)
-        {
-            typedef __invoke_void_return_wrapper<_Rp> _Invoker;
-            return _Invoker::__call(static_cast<base&>(*this), _VSTD::forward<_Args>(__args)...);
-        }
-
-    template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            is_convertible<typename __bind_return<const _Fd, const _Td, tuple<_Args&&...> >::type,
-                           result_type>::value || is_void<_Rp>::value,
-            result_type
-        >::type
-        operator()(_Args&& ...__args) const
-        {
-            typedef __invoke_void_return_wrapper<_Rp> _Invoker;
-            return _Invoker::__call(static_cast<base const&>(*this), _VSTD::forward<_Args>(__args)...);
-        }
-};
-
-template<class _Rp, class _Fp, class ..._BoundArgs>
-struct __is_bind_expression<__bind_r<_Rp, _Fp, _BoundArgs...> > : public true_type {};
-
-template<class _Fp, class ..._BoundArgs>
-inline _LIBCPP_INLINE_VISIBILITY
-__bind<_Fp, _BoundArgs...>
-bind(_Fp&& __f, _BoundArgs&&... __bound_args)
-{
-    typedef __bind<_Fp, _BoundArgs...> type;
-    return type(_VSTD::forward<_Fp>(__f), _VSTD::forward<_BoundArgs>(__bound_args)...);
-}
-
-template<class _Rp, class _Fp, class ..._BoundArgs>
-inline _LIBCPP_INLINE_VISIBILITY
-__bind_r<_Rp, _Fp, _BoundArgs...>
-bind(_Fp&& __f, _BoundArgs&&... __bound_args)
-{
-    typedef __bind_r<_Rp, _Fp, _BoundArgs...> type;
-    return type(_VSTD::forward<_Fp>(__f), _VSTD::forward<_BoundArgs>(__bound_args)...);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER > 14
-
-template <class _Fn, class ..._Args>
-result_of_t<_Fn&&(_Args&&...)>
-invoke(_Fn&& __f, _Args&&... __args)
-    noexcept(noexcept(_VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...)))
-{
-    return _VSTD::__invoke(_VSTD::forward<_Fn>(__f), _VSTD::forward<_Args>(__args)...);
-}
-
-template <class _DecayFunc>
-class _LIBCPP_TEMPLATE_VIS __not_fn_imp {
-  _DecayFunc __fd;
-
-public:
-    __not_fn_imp() = delete;
-
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_Args&& ...__args) &
-            noexcept(noexcept(!_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...)))
-        -> decltype(          !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...))
-        { return              !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...); }
-
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_Args&& ...__args) &&
-            noexcept(noexcept(!_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...)))
-        -> decltype(          !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...))
-        { return              !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...); }
-
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_Args&& ...__args) const&
-            noexcept(noexcept(!_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...)))
-        -> decltype(          !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...))
-        { return              !_VSTD::invoke(__fd, _VSTD::forward<_Args>(__args)...); }
-
-
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    auto operator()(_Args&& ...__args) const&&
-            noexcept(noexcept(!_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...)))
-        -> decltype(          !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...))
-        { return              !_VSTD::invoke(_VSTD::move(__fd), _VSTD::forward<_Args>(__args)...); }
-
-private:
-    template <class _RawFunc,
-              class = enable_if_t<!is_same<decay_t<_RawFunc>, __not_fn_imp>::value>>
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __not_fn_imp(_RawFunc&& __rf)
-        : __fd(_VSTD::forward<_RawFunc>(__rf)) {}
-
-    template <class _RawFunc>
-    friend inline _LIBCPP_INLINE_VISIBILITY
-    __not_fn_imp<decay_t<_RawFunc>> not_fn(_RawFunc&&);
-};
-
-template <class _RawFunc>
-inline _LIBCPP_INLINE_VISIBILITY
-__not_fn_imp<decay_t<_RawFunc>> not_fn(_RawFunc&& __fn) {
-    return __not_fn_imp<decay_t<_RawFunc>>(_VSTD::forward<_RawFunc>(__fn));
-}
-
-#endif
-
-// struct hash<T*> in <memory>
-
-template <class _BinaryPredicate, class _ForwardIterator1, class _ForwardIterator2>
-pair<_ForwardIterator1, _ForwardIterator1> _LIBCPP_CONSTEXPR_AFTER_CXX11
-__search(_ForwardIterator1 __first1, _ForwardIterator1 __last1,
-         _ForwardIterator2 __first2, _ForwardIterator2 __last2, _BinaryPredicate __pred,
-         forward_iterator_tag, forward_iterator_tag)
-{
-    if (__first2 == __last2)
-        return make_pair(__first1, __first1);  // Everything matches an empty sequence
-    while (true)
-    {
-        // Find first element in sequence 1 that matchs *__first2, with a mininum of loop checks
-        while (true)
-        {
-            if (__first1 == __last1)  // return __last1 if no element matches *__first2
-                return make_pair(__last1, __last1);
-            if (__pred(*__first1, *__first2))
-                break;
-            ++__first1;
-        }
-        // *__first1 matches *__first2, now match elements after here
-        _ForwardIterator1 __m1 = __first1;
-        _ForwardIterator2 __m2 = __first2;
-        while (true)
-        {
-            if (++__m2 == __last2)  // If pattern exhausted, __first1 is the answer (works for 1 element pattern)
-                return make_pair(__first1, __m1);
-            if (++__m1 == __last1)  // Otherwise if source exhaused, pattern not found
-                return make_pair(__last1, __last1);
-            if (!__pred(*__m1, *__m2))  // if there is a mismatch, restart with a new __first1
-            {
-                ++__first1;
-                break;
-            }  // else there is a match, check next elements
-        }
-    }
-}
-
-template <class _BinaryPredicate, class _RandomAccessIterator1, class _RandomAccessIterator2>
-_LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<_RandomAccessIterator1, _RandomAccessIterator1>
-__search(_RandomAccessIterator1 __first1, _RandomAccessIterator1 __last1,
-         _RandomAccessIterator2 __first2, _RandomAccessIterator2 __last2, _BinaryPredicate __pred,
-           random_access_iterator_tag, random_access_iterator_tag)
-{
-    typedef typename iterator_traits<_RandomAccessIterator1>::difference_type _D1;
-    typedef typename iterator_traits<_RandomAccessIterator2>::difference_type _D2;
-    // Take advantage of knowing source and pattern lengths.  Stop short when source is smaller than pattern
-    const _D2 __len2 = __last2 - __first2;
-    if (__len2 == 0)
-        return make_pair(__first1, __first1);
-    const _D1 __len1 = __last1 - __first1;
-    if (__len1 < __len2)
-        return make_pair(__last1, __last1);
-    const _RandomAccessIterator1 __s = __last1 - (__len2 - 1);  // Start of pattern match can't go beyond here
-
-    while (true)
-    {
-        while (true)
-        {
-            if (__first1 == __s)
-                return make_pair(__last1, __last1);
-            if (__pred(*__first1, *__first2))
-                break;
-            ++__first1;
-        }
-
-        _RandomAccessIterator1 __m1 = __first1;
-        _RandomAccessIterator2 __m2 = __first2;
-         while (true)
-         {
-             if (++__m2 == __last2)
-                 return make_pair(__first1, __first1 + __len2);
-             ++__m1;          // no need to check range on __m1 because __s guarantees we have enough source
-             if (!__pred(*__m1, *__m2))
-             {
-                 ++__first1;
-                 break;
-             }
-         }
-    }
-}
-
-#if _LIBCPP_STD_VER > 14
-
-// default searcher
-template<class _ForwardIterator, class _BinaryPredicate = equal_to<>>
-class _LIBCPP_TYPE_VIS default_searcher {
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    default_searcher(_ForwardIterator __f, _ForwardIterator __l,
-                       _BinaryPredicate __p = _BinaryPredicate())
-        : __first_(__f), __last_(__l), __pred_(__p) {}
-
-    template <typename _ForwardIterator2>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<_ForwardIterator2, _ForwardIterator2>
-    operator () (_ForwardIterator2 __f, _ForwardIterator2 __l) const
-    {
-        return _VSTD::__search(__f, __l, __first_, __last_, __pred_,
-            typename _VSTD::iterator_traits<_ForwardIterator>::iterator_category(),
-            typename _VSTD::iterator_traits<_ForwardIterator2>::iterator_category());
-    }
-
-private:
-    _ForwardIterator __first_;
-    _ForwardIterator __last_;
-    _BinaryPredicate __pred_;
-    };
-
-#endif // _LIBCPP_STD_VER > 14
-
-#if _LIBCPP_STD_VER > 17
-template <class _Tp>
-using unwrap_reference_t = typename unwrap_reference<_Tp>::type;
-
-template <class _Tp>
-using unwrap_ref_decay_t = typename unwrap_ref_decay<_Tp>::type;
-#endif // > C++17
-
-template <class _Container, class _Predicate>
-inline void __libcpp_erase_if_container( _Container& __c, _Predicate __pred)
-{
-	for (typename _Container::iterator __iter = __c.begin(), __last = __c.end(); __iter != __last;)
-	{
-		if (__pred(*__iter))
-			__iter = __c.erase(__iter);
-		else
-			++__iter;
-	}
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_FUNCTIONAL
diff --git a/lib/libcxx/include/future b/lib/libcxx/include/future
deleted file mode 100644
index b3ffc7e3517..00000000000
--- a/lib/libcxx/include/future
+++ /dev/null
@@ -1,2613 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- future -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_FUTURE
-#define _LIBCPP_FUTURE
-
-/*
-    future synopsis
-
-namespace std
-{
-
-enum class future_errc
-{
-    future_already_retrieved = 1,
-    promise_already_satisfied,
-    no_state,
-    broken_promise
-};
-
-enum class launch
-{
-    async = 1,
-    deferred = 2,
-    any = async | deferred
-};
-
-enum class future_status
-{
-    ready,
-    timeout,
-    deferred
-};
-
-template <> struct is_error_code_enum<future_errc> : public true_type { };
-error_code make_error_code(future_errc e) noexcept;
-error_condition make_error_condition(future_errc e) noexcept;
-
-const error_category& future_category() noexcept;
-
-class future_error
-    : public logic_error
-{
-public:
-    future_error(error_code ec);  // exposition only
-    explicit future_error(future_errc); // C++17
-    const error_code& code() const noexcept;
-    const char*       what() const noexcept;
-};
-
-template <class R>
-class promise
-{
-public:
-    promise();
-    template <class Allocator>
-        promise(allocator_arg_t, const Allocator& a);
-    promise(promise&& rhs) noexcept;
-    promise(const promise& rhs) = delete;
-    ~promise();
-
-    // assignment
-    promise& operator=(promise&& rhs) noexcept;
-    promise& operator=(const promise& rhs) = delete;
-    void swap(promise& other) noexcept;
-
-    // retrieving the result
-    future<R> get_future();
-
-    // setting the result
-    void set_value(const R& r);
-    void set_value(R&& r);
-    void set_exception(exception_ptr p);
-
-    // setting the result with deferred notification
-    void set_value_at_thread_exit(const R& r);
-    void set_value_at_thread_exit(R&& r);
-    void set_exception_at_thread_exit(exception_ptr p);
-};
-
-template <class R>
-class promise<R&>
-{
-public:
-    promise();
-    template <class Allocator>
-        promise(allocator_arg_t, const Allocator& a);
-    promise(promise&& rhs) noexcept;
-    promise(const promise& rhs) = delete;
-    ~promise();
-
-    // assignment
-    promise& operator=(promise&& rhs) noexcept;
-    promise& operator=(const promise& rhs) = delete;
-    void swap(promise& other) noexcept;
-
-    // retrieving the result
-    future<R&> get_future();
-
-    // setting the result
-    void set_value(R& r);
-    void set_exception(exception_ptr p);
-
-    // setting the result with deferred notification
-    void set_value_at_thread_exit(R&);
-    void set_exception_at_thread_exit(exception_ptr p);
-};
-
-template <>
-class promise<void>
-{
-public:
-    promise();
-    template <class Allocator>
-        promise(allocator_arg_t, const Allocator& a);
-    promise(promise&& rhs) noexcept;
-    promise(const promise& rhs) = delete;
-    ~promise();
-
-    // assignment
-    promise& operator=(promise&& rhs) noexcept;
-    promise& operator=(const promise& rhs) = delete;
-    void swap(promise& other) noexcept;
-
-    // retrieving the result
-    future<void> get_future();
-
-    // setting the result
-    void set_value();
-    void set_exception(exception_ptr p);
-
-    // setting the result with deferred notification
-    void set_value_at_thread_exit();
-    void set_exception_at_thread_exit(exception_ptr p);
-};
-
-template <class R> void swap(promise<R>& x, promise<R>& y) noexcept;
-
-template <class R, class Alloc>
-    struct uses_allocator<promise<R>, Alloc> : public true_type {};
-
-template <class R>
-class future
-{
-public:
-    future() noexcept;
-    future(future&&) noexcept;
-    future(const future& rhs) = delete;
-    ~future();
-    future& operator=(const future& rhs) = delete;
-    future& operator=(future&&) noexcept;
-    shared_future<R> share() noexcept;
-
-    // retrieving the value
-    R get();
-
-    // functions to check state
-    bool valid() const noexcept;
-
-    void wait() const;
-    template <class Rep, class Period>
-        future_status
-        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
-    template <class Clock, class Duration>
-        future_status
-        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
-};
-
-template <class R>
-class future<R&>
-{
-public:
-    future() noexcept;
-    future(future&&) noexcept;
-    future(const future& rhs) = delete;
-    ~future();
-    future& operator=(const future& rhs) = delete;
-    future& operator=(future&&) noexcept;
-    shared_future<R&> share() noexcept;
-
-    // retrieving the value
-    R& get();
-
-    // functions to check state
-    bool valid() const noexcept;
-
-    void wait() const;
-    template <class Rep, class Period>
-        future_status
-        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
-    template <class Clock, class Duration>
-        future_status
-        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
-};
-
-template <>
-class future<void>
-{
-public:
-    future() noexcept;
-    future(future&&) noexcept;
-    future(const future& rhs) = delete;
-    ~future();
-    future& operator=(const future& rhs) = delete;
-    future& operator=(future&&) noexcept;
-    shared_future<void> share() noexcept;
-
-    // retrieving the value
-    void get();
-
-    // functions to check state
-    bool valid() const noexcept;
-
-    void wait() const;
-    template <class Rep, class Period>
-        future_status
-        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
-    template <class Clock, class Duration>
-        future_status
-        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
-};
-
-template <class R>
-class shared_future
-{
-public:
-    shared_future() noexcept;
-    shared_future(const shared_future& rhs);
-    shared_future(future<R>&&) noexcept;
-    shared_future(shared_future&& rhs) noexcept;
-    ~shared_future();
-    shared_future& operator=(const shared_future& rhs);
-    shared_future& operator=(shared_future&& rhs) noexcept;
-
-    // retrieving the value
-    const R& get() const;
-
-    // functions to check state
-    bool valid() const noexcept;
-
-    void wait() const;
-    template <class Rep, class Period>
-        future_status
-        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
-    template <class Clock, class Duration>
-        future_status
-        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
-};
-
-template <class R>
-class shared_future<R&>
-{
-public:
-    shared_future() noexcept;
-    shared_future(const shared_future& rhs);
-    shared_future(future<R&>&&) noexcept;
-    shared_future(shared_future&& rhs) noexcept;
-    ~shared_future();
-    shared_future& operator=(const shared_future& rhs);
-    shared_future& operator=(shared_future&& rhs) noexcept;
-
-    // retrieving the value
-    R& get() const;
-
-    // functions to check state
-    bool valid() const noexcept;
-
-    void wait() const;
-    template <class Rep, class Period>
-        future_status
-        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
-    template <class Clock, class Duration>
-        future_status
-        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
-};
-
-template <>
-class shared_future<void>
-{
-public:
-    shared_future() noexcept;
-    shared_future(const shared_future& rhs);
-    shared_future(future<void>&&) noexcept;
-    shared_future(shared_future&& rhs) noexcept;
-    ~shared_future();
-    shared_future& operator=(const shared_future& rhs);
-    shared_future& operator=(shared_future&& rhs) noexcept;
-
-    // retrieving the value
-    void get() const;
-
-    // functions to check state
-    bool valid() const noexcept;
-
-    void wait() const;
-    template <class Rep, class Period>
-        future_status
-        wait_for(const chrono::duration<Rep, Period>& rel_time) const;
-    template <class Clock, class Duration>
-        future_status
-        wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
-};
-
-template <class F, class... Args>
-  future<typename result_of<typename decay<F>::type(typename decay<Args>::type...)>::type>
-  async(F&& f, Args&&... args);
-
-template <class F, class... Args>
-  future<typename result_of<typename decay<F>::type(typename decay<Args>::type...)>::type>
-  async(launch policy, F&& f, Args&&... args);
-
-template <class> class packaged_task; // undefined
-
-template <class R, class... ArgTypes>
-class packaged_task<R(ArgTypes...)>
-{
-public:
-    typedef R result_type; // extension
-
-    // construction and destruction
-    packaged_task() noexcept;
-    template <class F>
-        explicit packaged_task(F&& f);
-    template <class F, class Allocator>
-        packaged_task(allocator_arg_t, const Allocator& a, F&& f);
-    ~packaged_task();
-
-    // no copy
-    packaged_task(const packaged_task&) = delete;
-    packaged_task& operator=(const packaged_task&) = delete;
-
-    // move support
-    packaged_task(packaged_task&& other) noexcept;
-    packaged_task& operator=(packaged_task&& other) noexcept;
-    void swap(packaged_task& other) noexcept;
-
-    bool valid() const noexcept;
-
-    // result retrieval
-    future<R> get_future();
-
-    // execution
-    void operator()(ArgTypes... );
-    void make_ready_at_thread_exit(ArgTypes...);
-
-    void reset();
-};
-
-template <class R>
-  void swap(packaged_task<R(ArgTypes...)&, packaged_task<R(ArgTypes...)>&) noexcept;
-
-template <class R, class Alloc> struct uses_allocator<packaged_task<R>, Alloc>;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <system_error>
-#include <memory>
-#include <chrono>
-#include <exception>
-#include <mutex>
-#include <thread>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef _LIBCPP_HAS_NO_THREADS
-#error <future> is not supported on this single threaded system
-#else // !_LIBCPP_HAS_NO_THREADS
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-//enum class future_errc
-_LIBCPP_DECLARE_STRONG_ENUM(future_errc)
-{
-    future_already_retrieved = 1,
-    promise_already_satisfied,
-    no_state,
-    broken_promise
-};
-_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(future_errc)
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS is_error_code_enum<future_errc> : public true_type {};
-
-#ifdef _LIBCPP_HAS_NO_STRONG_ENUMS
-template <>
-struct _LIBCPP_TEMPLATE_VIS is_error_code_enum<future_errc::__lx> : public true_type { };
-#endif
-
-//enum class launch
-_LIBCPP_DECLARE_STRONG_ENUM(launch)
-{
-    async = 1,
-    deferred = 2,
-    any = async | deferred
-};
-_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(launch)
-
-#ifndef _LIBCPP_HAS_NO_STRONG_ENUMS
-
-#ifdef _LIBCPP_UNDERLYING_TYPE
-typedef underlying_type<launch>::type __launch_underlying_type;
-#else
-typedef int __launch_underlying_type;
-#endif
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-launch
-operator&(launch __x, launch __y)
-{
-    return static_cast<launch>(static_cast<__launch_underlying_type>(__x) &
-                               static_cast<__launch_underlying_type>(__y));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-launch
-operator|(launch __x, launch __y)
-{
-    return static_cast<launch>(static_cast<__launch_underlying_type>(__x) |
-                               static_cast<__launch_underlying_type>(__y));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-launch
-operator^(launch __x, launch __y)
-{
-    return static_cast<launch>(static_cast<__launch_underlying_type>(__x) ^
-                               static_cast<__launch_underlying_type>(__y));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-launch
-operator~(launch __x)
-{
-    return static_cast<launch>(~static_cast<__launch_underlying_type>(__x) & 3);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-launch&
-operator&=(launch& __x, launch __y)
-{
-    __x = __x & __y; return __x;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-launch&
-operator|=(launch& __x, launch __y)
-{
-    __x = __x | __y; return __x;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-launch&
-operator^=(launch& __x, launch __y)
-{
-    __x = __x ^ __y; return __x;
-}
-
-#endif  // !_LIBCPP_HAS_NO_STRONG_ENUMS
-
-//enum class future_status
-_LIBCPP_DECLARE_STRONG_ENUM(future_status)
-{
-    ready,
-    timeout,
-    deferred
-};
-_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(future_status)
-
-_LIBCPP_FUNC_VIS
-const error_category& future_category() _NOEXCEPT;
-
-inline _LIBCPP_INLINE_VISIBILITY
-error_code
-make_error_code(future_errc __e) _NOEXCEPT
-{
-    return error_code(static_cast<int>(__e), future_category());
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-error_condition
-make_error_condition(future_errc __e) _NOEXCEPT
-{
-    return error_condition(static_cast<int>(__e), future_category());
-}
-
-class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_FUTURE_ERROR future_error
-    : public logic_error
-{
-    error_code __ec_;
-public:
-    future_error(error_code __ec);
-#if _LIBCPP_STD_VERS > 14
-    explicit future_error(future_errc _Ev) : logic_error(), __ec_(make_error_code(_Ev)) {}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    const error_code& code() const _NOEXCEPT {return __ec_;}
-
-    virtual ~future_error() _NOEXCEPT;
-};
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_NO_EXCEPTIONS
-_LIBCPP_AVAILABILITY_FUTURE_ERROR
-#endif
-void __throw_future_error(future_errc _Ev)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw future_error(make_error_code(_Ev));
-#else
-    ((void)_Ev);
-    _VSTD::abort();
-#endif
-}
-
-class _LIBCPP_TYPE_VIS _LIBCPP_AVAILABILITY_FUTURE __assoc_sub_state
-    : public __shared_count
-{
-protected:
-    exception_ptr __exception_;
-    mutable mutex __mut_;
-    mutable condition_variable __cv_;
-    unsigned __state_;
-
-    virtual void __on_zero_shared() _NOEXCEPT;
-    void __sub_wait(unique_lock<mutex>& __lk);
-public:
-    enum
-    {
-        __constructed = 1,
-        __future_attached = 2,
-        ready = 4,
-        deferred = 8
-    };
-
-    _LIBCPP_INLINE_VISIBILITY
-    __assoc_sub_state() : __state_(0) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool __has_value() const
-        {return (__state_ & __constructed) || (__exception_ != nullptr);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __attach_future() {
-        lock_guard<mutex> __lk(__mut_);
-        bool __has_future_attached = (__state_ & __future_attached) != 0;
-        if (__has_future_attached)
-            __throw_future_error(future_errc::future_already_retrieved);
-        this->__add_shared();
-        __state_ |= __future_attached;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __set_deferred() {__state_ |= deferred;}
-
-    void __make_ready();
-    _LIBCPP_INLINE_VISIBILITY
-    bool __is_ready() const {return (__state_ & ready) != 0;}
-
-    void set_value();
-    void set_value_at_thread_exit();
-
-    void set_exception(exception_ptr __p);
-    void set_exception_at_thread_exit(exception_ptr __p);
-
-    void copy();
-
-    void wait();
-    template <class _Rep, class _Period>
-        future_status
-        _LIBCPP_INLINE_VISIBILITY
-        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const;
-    template <class _Clock, class _Duration>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        future_status
-        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const;
-
-    virtual void __execute();
-};
-
-template <class _Clock, class _Duration>
-future_status
-__assoc_sub_state::wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
-{
-    unique_lock<mutex> __lk(__mut_);
-    if (__state_ & deferred)
-        return future_status::deferred;
-    while (!(__state_ & ready) && _Clock::now() < __abs_time)
-        __cv_.wait_until(__lk, __abs_time);
-    if (__state_ & ready)
-        return future_status::ready;
-    return future_status::timeout;
-}
-
-template <class _Rep, class _Period>
-inline
-future_status
-__assoc_sub_state::wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
-{
-    return wait_until(chrono::steady_clock::now() + __rel_time);
-}
-
-template <class _Rp>
-class _LIBCPP_AVAILABILITY_FUTURE __assoc_state
-    : public __assoc_sub_state
-{
-    typedef __assoc_sub_state base;
-    typedef typename aligned_storage<sizeof(_Rp), alignment_of<_Rp>::value>::type _Up;
-protected:
-    _Up __value_;
-
-    virtual void __on_zero_shared() _NOEXCEPT;
-public:
-
-    template <class _Arg>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-        void set_value(_Arg&& __arg);
-#else
-        void set_value(_Arg& __arg);
-#endif
-
-    template <class _Arg>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-        void set_value_at_thread_exit(_Arg&& __arg);
-#else
-        void set_value_at_thread_exit(_Arg& __arg);
-#endif
-
-    _Rp move();
-    typename add_lvalue_reference<_Rp>::type copy();
-};
-
-template <class _Rp>
-void
-__assoc_state<_Rp>::__on_zero_shared() _NOEXCEPT
-{
-    if (this->__state_ & base::__constructed)
-        reinterpret_cast<_Rp*>(&__value_)->~_Rp();
-    delete this;
-}
-
-template <class _Rp>
-template <class _Arg>
-_LIBCPP_AVAILABILITY_FUTURE
-void
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-__assoc_state<_Rp>::set_value(_Arg&& __arg)
-#else
-__assoc_state<_Rp>::set_value(_Arg& __arg)
-#endif
-{
-    unique_lock<mutex> __lk(this->__mut_);
-    if (this->__has_value())
-        __throw_future_error(future_errc::promise_already_satisfied);
-    ::new(&__value_) _Rp(_VSTD::forward<_Arg>(__arg));
-    this->__state_ |= base::__constructed | base::ready;
-    __cv_.notify_all();
-}
-
-template <class _Rp>
-template <class _Arg>
-void
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-__assoc_state<_Rp>::set_value_at_thread_exit(_Arg&& __arg)
-#else
-__assoc_state<_Rp>::set_value_at_thread_exit(_Arg& __arg)
-#endif
-{
-    unique_lock<mutex> __lk(this->__mut_);
-    if (this->__has_value())
-        __throw_future_error(future_errc::promise_already_satisfied);
-    ::new(&__value_) _Rp(_VSTD::forward<_Arg>(__arg));
-    this->__state_ |= base::__constructed;
-    __thread_local_data()->__make_ready_at_thread_exit(this);
-}
-
-template <class _Rp>
-_Rp
-__assoc_state<_Rp>::move()
-{
-    unique_lock<mutex> __lk(this->__mut_);
-    this->__sub_wait(__lk);
-    if (this->__exception_ != nullptr)
-        rethrow_exception(this->__exception_);
-    return _VSTD::move(*reinterpret_cast<_Rp*>(&__value_));
-}
-
-template <class _Rp>
-typename add_lvalue_reference<_Rp>::type
-__assoc_state<_Rp>::copy()
-{
-    unique_lock<mutex> __lk(this->__mut_);
-    this->__sub_wait(__lk);
-    if (this->__exception_ != nullptr)
-        rethrow_exception(this->__exception_);
-    return *reinterpret_cast<_Rp*>(&__value_);
-}
-
-template <class _Rp>
-class _LIBCPP_AVAILABILITY_FUTURE __assoc_state<_Rp&>
-    : public __assoc_sub_state
-{
-    typedef __assoc_sub_state base;
-    typedef _Rp* _Up;
-protected:
-    _Up __value_;
-
-    virtual void __on_zero_shared() _NOEXCEPT;
-public:
-
-    void set_value(_Rp& __arg);
-    void set_value_at_thread_exit(_Rp& __arg);
-
-    _Rp& copy();
-};
-
-template <class _Rp>
-void
-__assoc_state<_Rp&>::__on_zero_shared() _NOEXCEPT
-{
-    delete this;
-}
-
-template <class _Rp>
-void
-__assoc_state<_Rp&>::set_value(_Rp& __arg)
-{
-    unique_lock<mutex> __lk(this->__mut_);
-    if (this->__has_value())
-        __throw_future_error(future_errc::promise_already_satisfied);
-    __value_ = _VSTD::addressof(__arg);
-    this->__state_ |= base::__constructed | base::ready;
-    __cv_.notify_all();
-}
-
-template <class _Rp>
-void
-__assoc_state<_Rp&>::set_value_at_thread_exit(_Rp& __arg)
-{
-    unique_lock<mutex> __lk(this->__mut_);
-    if (this->__has_value())
-        __throw_future_error(future_errc::promise_already_satisfied);
-    __value_ = _VSTD::addressof(__arg);
-    this->__state_ |= base::__constructed;
-    __thread_local_data()->__make_ready_at_thread_exit(this);
-}
-
-template <class _Rp>
-_Rp&
-__assoc_state<_Rp&>::copy()
-{
-    unique_lock<mutex> __lk(this->__mut_);
-    this->__sub_wait(__lk);
-    if (this->__exception_ != nullptr)
-        rethrow_exception(this->__exception_);
-    return *__value_;
-}
-
-template <class _Rp, class _Alloc>
-class _LIBCPP_AVAILABILITY_FUTURE __assoc_state_alloc
-    : public __assoc_state<_Rp>
-{
-    typedef __assoc_state<_Rp> base;
-    _Alloc __alloc_;
-
-    virtual void __on_zero_shared() _NOEXCEPT;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __assoc_state_alloc(const _Alloc& __a)
-        : __alloc_(__a) {}
-};
-
-template <class _Rp, class _Alloc>
-void
-__assoc_state_alloc<_Rp, _Alloc>::__on_zero_shared() _NOEXCEPT
-{
-    if (this->__state_ & base::__constructed)
-        reinterpret_cast<_Rp*>(_VSTD::addressof(this->__value_))->~_Rp();
-    typedef typename __allocator_traits_rebind<_Alloc, __assoc_state_alloc>::type _Al;
-    typedef allocator_traits<_Al> _ATraits;
-    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
-    _Al __a(__alloc_);
-    this->~__assoc_state_alloc();
-    __a.deallocate(_PTraits::pointer_to(*this), 1);
-}
-
-template <class _Rp, class _Alloc>
-class _LIBCPP_AVAILABILITY_FUTURE __assoc_state_alloc<_Rp&, _Alloc>
-    : public __assoc_state<_Rp&>
-{
-    typedef __assoc_state<_Rp&> base;
-    _Alloc __alloc_;
-
-    virtual void __on_zero_shared() _NOEXCEPT;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __assoc_state_alloc(const _Alloc& __a)
-        : __alloc_(__a) {}
-};
-
-template <class _Rp, class _Alloc>
-void
-__assoc_state_alloc<_Rp&, _Alloc>::__on_zero_shared() _NOEXCEPT
-{
-    typedef typename __allocator_traits_rebind<_Alloc, __assoc_state_alloc>::type _Al;
-    typedef allocator_traits<_Al> _ATraits;
-    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
-    _Al __a(__alloc_);
-    this->~__assoc_state_alloc();
-    __a.deallocate(_PTraits::pointer_to(*this), 1);
-}
-
-template <class _Alloc>
-class _LIBCPP_AVAILABILITY_FUTURE __assoc_sub_state_alloc
-    : public __assoc_sub_state
-{
-    typedef __assoc_sub_state base;
-    _Alloc __alloc_;
-
-    virtual void __on_zero_shared() _NOEXCEPT;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __assoc_sub_state_alloc(const _Alloc& __a)
-        : __alloc_(__a) {}
-};
-
-template <class _Alloc>
-void
-__assoc_sub_state_alloc<_Alloc>::__on_zero_shared() _NOEXCEPT
-{
-    typedef typename __allocator_traits_rebind<_Alloc, __assoc_sub_state_alloc>::type _Al;
-    typedef allocator_traits<_Al> _ATraits;
-    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
-    _Al __a(__alloc_);
-    this->~__assoc_sub_state_alloc();
-    __a.deallocate(_PTraits::pointer_to(*this), 1);
-}
-
-template <class _Rp, class _Fp>
-class _LIBCPP_AVAILABILITY_FUTURE __deferred_assoc_state
-    : public __assoc_state<_Rp>
-{
-    typedef __assoc_state<_Rp> base;
-
-    _Fp __func_;
-
-public:
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __deferred_assoc_state(_Fp&& __f);
-#endif
-
-    virtual void __execute();
-};
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Rp, class _Fp>
-inline
-__deferred_assoc_state<_Rp, _Fp>::__deferred_assoc_state(_Fp&& __f)
-    : __func_(_VSTD::forward<_Fp>(__f))
-{
-    this->__set_deferred();
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Rp, class _Fp>
-void
-__deferred_assoc_state<_Rp, _Fp>::__execute()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        this->set_value(__func_());
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->set_exception(current_exception());
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template <class _Fp>
-class _LIBCPP_AVAILABILITY_FUTURE __deferred_assoc_state<void, _Fp>
-    : public __assoc_sub_state
-{
-    typedef __assoc_sub_state base;
-
-    _Fp __func_;
-
-public:
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __deferred_assoc_state(_Fp&& __f);
-#endif
-
-    virtual void __execute();
-};
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Fp>
-inline
-__deferred_assoc_state<void, _Fp>::__deferred_assoc_state(_Fp&& __f)
-    : __func_(_VSTD::forward<_Fp>(__f))
-{
-    this->__set_deferred();
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Fp>
-void
-__deferred_assoc_state<void, _Fp>::__execute()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __func_();
-        this->set_value();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->set_exception(current_exception());
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template <class _Rp, class _Fp>
-class _LIBCPP_AVAILABILITY_FUTURE __async_assoc_state
-    : public __assoc_state<_Rp>
-{
-    typedef __assoc_state<_Rp> base;
-
-    _Fp __func_;
-
-    virtual void __on_zero_shared() _NOEXCEPT;
-public:
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __async_assoc_state(_Fp&& __f);
-#endif
-
-    virtual void __execute();
-};
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Rp, class _Fp>
-inline
-__async_assoc_state<_Rp, _Fp>::__async_assoc_state(_Fp&& __f)
-    : __func_(_VSTD::forward<_Fp>(__f))
-{
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Rp, class _Fp>
-void
-__async_assoc_state<_Rp, _Fp>::__execute()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        this->set_value(__func_());
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->set_exception(current_exception());
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template <class _Rp, class _Fp>
-void
-__async_assoc_state<_Rp, _Fp>::__on_zero_shared() _NOEXCEPT
-{
-    this->wait();
-    base::__on_zero_shared();
-}
-
-template <class _Fp>
-class _LIBCPP_AVAILABILITY_FUTURE __async_assoc_state<void, _Fp>
-    : public __assoc_sub_state
-{
-    typedef __assoc_sub_state base;
-
-    _Fp __func_;
-
-    virtual void __on_zero_shared() _NOEXCEPT;
-public:
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __async_assoc_state(_Fp&& __f);
-#endif
-
-    virtual void __execute();
-};
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Fp>
-inline
-__async_assoc_state<void, _Fp>::__async_assoc_state(_Fp&& __f)
-    : __func_(_VSTD::forward<_Fp>(__f))
-{
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Fp>
-void
-__async_assoc_state<void, _Fp>::__execute()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __func_();
-        this->set_value();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->set_exception(current_exception());
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template <class _Fp>
-void
-__async_assoc_state<void, _Fp>::__on_zero_shared() _NOEXCEPT
-{
-    this->wait();
-    base::__on_zero_shared();
-}
-
-template <class _Rp> class _LIBCPP_TEMPLATE_VIS promise;
-template <class _Rp> class _LIBCPP_TEMPLATE_VIS shared_future;
-
-// future
-
-template <class _Rp> class _LIBCPP_TEMPLATE_VIS future;
-
-template <class _Rp, class _Fp>
-future<_Rp>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-__make_deferred_assoc_state(_Fp&& __f);
-#else
-__make_deferred_assoc_state(_Fp __f);
-#endif
-
-template <class _Rp, class _Fp>
-future<_Rp>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-__make_async_assoc_state(_Fp&& __f);
-#else
-__make_async_assoc_state(_Fp __f);
-#endif
-
-template <class _Rp>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FUTURE future
-{
-    __assoc_state<_Rp>* __state_;
-
-    explicit future(__assoc_state<_Rp>* __state);
-
-    template <class> friend class promise;
-    template <class> friend class shared_future;
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_async_assoc_state(_Fp&& __f);
-#else
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_deferred_assoc_state(_Fp __f);
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_async_assoc_state(_Fp __f);
-#endif
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    future() _NOEXCEPT : __state_(nullptr) {}
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    future(future&& __rhs) _NOEXCEPT
-        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
-    future(const future&) = delete;
-    future& operator=(const future&) = delete;
-    _LIBCPP_INLINE_VISIBILITY
-    future& operator=(future&& __rhs) _NOEXCEPT
-        {
-            future(std::move(__rhs)).swap(*this);
-            return *this;
-        }
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-private:
-    future(const future&);
-    future& operator=(const future&);
-public:
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~future();
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future<_Rp> share() _NOEXCEPT;
-
-    // retrieving the value
-    _Rp get();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
-
-    // functions to check state
-    _LIBCPP_INLINE_VISIBILITY
-    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void wait() const {__state_->wait();}
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
-            {return __state_->wait_for(__rel_time);}
-    template <class _Clock, class _Duration>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
-            {return __state_->wait_until(__abs_time);}
-};
-
-template <class _Rp>
-future<_Rp>::future(__assoc_state<_Rp>* __state)
-    : __state_(__state)
-{
-    __state_->__attach_future();
-}
-
-struct __release_shared_count
-{
-    void operator()(__shared_count* p) {p->__release_shared();}
-};
-
-template <class _Rp>
-future<_Rp>::~future()
-{
-    if (__state_)
-        __state_->__release_shared();
-}
-
-template <class _Rp>
-_Rp
-future<_Rp>::get()
-{
-    unique_ptr<__shared_count, __release_shared_count> __(__state_);
-    __assoc_state<_Rp>* __s = __state_;
-    __state_ = nullptr;
-    return __s->move();
-}
-
-template <class _Rp>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FUTURE future<_Rp&>
-{
-    __assoc_state<_Rp&>* __state_;
-
-    explicit future(__assoc_state<_Rp&>* __state);
-
-    template <class> friend class promise;
-    template <class> friend class shared_future;
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_async_assoc_state(_Fp&& __f);
-#else
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_deferred_assoc_state(_Fp __f);
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_async_assoc_state(_Fp __f);
-#endif
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    future() _NOEXCEPT : __state_(nullptr) {}
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    future(future&& __rhs) _NOEXCEPT
-        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
-    future(const future&) = delete;
-    future& operator=(const future&) = delete;
-    _LIBCPP_INLINE_VISIBILITY
-    future& operator=(future&& __rhs) _NOEXCEPT
-        {
-            future(std::move(__rhs)).swap(*this);
-            return *this;
-        }
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-private:
-    future(const future&);
-    future& operator=(const future&);
-public:
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~future();
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future<_Rp&> share() _NOEXCEPT;
-
-    // retrieving the value
-    _Rp& get();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
-
-    // functions to check state
-    _LIBCPP_INLINE_VISIBILITY
-    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void wait() const {__state_->wait();}
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
-            {return __state_->wait_for(__rel_time);}
-    template <class _Clock, class _Duration>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
-            {return __state_->wait_until(__abs_time);}
-};
-
-template <class _Rp>
-future<_Rp&>::future(__assoc_state<_Rp&>* __state)
-    : __state_(__state)
-{
-    __state_->__attach_future();
-}
-
-template <class _Rp>
-future<_Rp&>::~future()
-{
-    if (__state_)
-        __state_->__release_shared();
-}
-
-template <class _Rp>
-_Rp&
-future<_Rp&>::get()
-{
-    unique_ptr<__shared_count, __release_shared_count> __(__state_);
-    __assoc_state<_Rp&>* __s = __state_;
-    __state_ = nullptr;
-    return __s->copy();
-}
-
-template <>
-class _LIBCPP_TYPE_VIS _LIBCPP_AVAILABILITY_FUTURE future<void>
-{
-    __assoc_sub_state* __state_;
-
-    explicit future(__assoc_sub_state* __state);
-
-    template <class> friend class promise;
-    template <class> friend class shared_future;
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_deferred_assoc_state(_Fp&& __f);
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_async_assoc_state(_Fp&& __f);
-#else
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_deferred_assoc_state(_Fp __f);
-    template <class _R1, class _Fp>
-        friend future<_R1> __make_async_assoc_state(_Fp __f);
-#endif
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    future() _NOEXCEPT : __state_(nullptr) {}
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    future(future&& __rhs) _NOEXCEPT
-        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
-    future(const future&) = delete;
-    future& operator=(const future&) = delete;
-    _LIBCPP_INLINE_VISIBILITY
-    future& operator=(future&& __rhs) _NOEXCEPT
-        {
-            future(std::move(__rhs)).swap(*this);
-            return *this;
-        }
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-private:
-    future(const future&);
-    future& operator=(const future&);
-public:
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~future();
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future<void> share() _NOEXCEPT;
-
-    // retrieving the value
-    void get();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
-
-    // functions to check state
-    _LIBCPP_INLINE_VISIBILITY
-    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void wait() const {__state_->wait();}
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
-            {return __state_->wait_for(__rel_time);}
-    template <class _Clock, class _Duration>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
-            {return __state_->wait_until(__abs_time);}
-};
-
-template <class _Rp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(future<_Rp>& __x, future<_Rp>& __y) _NOEXCEPT
-{
-    __x.swap(__y);
-}
-
-// promise<R>
-
-template <class _Callable> class packaged_task;
-
-template <class _Rp>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FUTURE promise
-{
-    __assoc_state<_Rp>* __state_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
-
-    template <class> friend class packaged_task;
-public:
-    promise();
-    template <class _Alloc>
-        promise(allocator_arg_t, const _Alloc& __a);
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    promise(promise&& __rhs) _NOEXCEPT
-        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
-    promise(const promise& __rhs) = delete;
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-private:
-    promise(const promise& __rhs);
-public:
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~promise();
-
-    // assignment
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    promise& operator=(promise&& __rhs) _NOEXCEPT
-        {
-            promise(std::move(__rhs)).swap(*this);
-            return *this;
-        }
-    promise& operator=(const promise& __rhs) = delete;
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-private:
-    promise& operator=(const promise& __rhs);
-public:
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(promise& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
-
-    // retrieving the result
-    future<_Rp> get_future();
-
-    // setting the result
-    void set_value(const _Rp& __r);
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    void set_value(_Rp&& __r);
-#endif
-    void set_exception(exception_ptr __p);
-
-    // setting the result with deferred notification
-    void set_value_at_thread_exit(const _Rp& __r);
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    void set_value_at_thread_exit(_Rp&& __r);
-#endif
-    void set_exception_at_thread_exit(exception_ptr __p);
-};
-
-template <class _Rp>
-promise<_Rp>::promise()
-    : __state_(new __assoc_state<_Rp>)
-{
-}
-
-template <class _Rp>
-template <class _Alloc>
-promise<_Rp>::promise(allocator_arg_t, const _Alloc& __a0)
-{
-    typedef __assoc_state_alloc<_Rp, _Alloc> _State;
-    typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
-    typedef __allocator_destructor<_A2> _D2;
-    _A2 __a(__a0);
-    unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
-    ::new(static_cast<void*>(_VSTD::addressof(*__hold.get()))) _State(__a0);
-    __state_ = _VSTD::addressof(*__hold.release());
-}
-
-template <class _Rp>
-promise<_Rp>::~promise()
-{
-    if (__state_)
-    {
-        if (!__state_->__has_value() && __state_->use_count() > 1)
-            __state_->set_exception(make_exception_ptr(
-                      future_error(make_error_code(future_errc::broken_promise))
-                                                      ));
-        __state_->__release_shared();
-    }
-}
-
-template <class _Rp>
-future<_Rp>
-promise<_Rp>::get_future()
-{
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    return future<_Rp>(__state_);
-}
-
-template <class _Rp>
-void
-promise<_Rp>::set_value(const _Rp& __r)
-{
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_value(__r);
-}
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Rp>
-void
-promise<_Rp>::set_value(_Rp&& __r)
-{
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_value(_VSTD::move(__r));
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Rp>
-void
-promise<_Rp>::set_exception(exception_ptr __p)
-{
-    _LIBCPP_ASSERT( __p != nullptr, "promise::set_exception: received nullptr" );
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_exception(__p);
-}
-
-template <class _Rp>
-void
-promise<_Rp>::set_value_at_thread_exit(const _Rp& __r)
-{
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_value_at_thread_exit(__r);
-}
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Rp>
-void
-promise<_Rp>::set_value_at_thread_exit(_Rp&& __r)
-{
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_value_at_thread_exit(_VSTD::move(__r));
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Rp>
-void
-promise<_Rp>::set_exception_at_thread_exit(exception_ptr __p)
-{
-    _LIBCPP_ASSERT( __p != nullptr, "promise::set_exception_at_thread_exit: received nullptr" );
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_exception_at_thread_exit(__p);
-}
-
-// promise<R&>
-
-template <class _Rp>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FUTURE promise<_Rp&>
-{
-    __assoc_state<_Rp&>* __state_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
-
-    template <class> friend class packaged_task;
-
-public:
-    promise();
-    template <class _Allocator>
-        promise(allocator_arg_t, const _Allocator& __a);
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    promise(promise&& __rhs) _NOEXCEPT
-        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
-    promise(const promise& __rhs) = delete;
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-private:
-    promise(const promise& __rhs);
-public:
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~promise();
-
-    // assignment
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    promise& operator=(promise&& __rhs) _NOEXCEPT
-        {
-            promise(std::move(__rhs)).swap(*this);
-            return *this;
-        }
-    promise& operator=(const promise& __rhs) = delete;
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-private:
-    promise& operator=(const promise& __rhs);
-public:
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(promise& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
-
-    // retrieving the result
-    future<_Rp&> get_future();
-
-    // setting the result
-    void set_value(_Rp& __r);
-    void set_exception(exception_ptr __p);
-
-    // setting the result with deferred notification
-    void set_value_at_thread_exit(_Rp&);
-    void set_exception_at_thread_exit(exception_ptr __p);
-};
-
-template <class _Rp>
-promise<_Rp&>::promise()
-    : __state_(new __assoc_state<_Rp&>)
-{
-}
-
-template <class _Rp>
-template <class _Alloc>
-promise<_Rp&>::promise(allocator_arg_t, const _Alloc& __a0)
-{
-    typedef __assoc_state_alloc<_Rp&, _Alloc> _State;
-    typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
-    typedef __allocator_destructor<_A2> _D2;
-    _A2 __a(__a0);
-    unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
-    ::new(static_cast<void*>(_VSTD::addressof(*__hold.get()))) _State(__a0);
-    __state_ = _VSTD::addressof(*__hold.release());
-}
-
-template <class _Rp>
-promise<_Rp&>::~promise()
-{
-    if (__state_)
-    {
-        if (!__state_->__has_value() && __state_->use_count() > 1)
-            __state_->set_exception(make_exception_ptr(
-                      future_error(make_error_code(future_errc::broken_promise))
-                                                      ));
-        __state_->__release_shared();
-    }
-}
-
-template <class _Rp>
-future<_Rp&>
-promise<_Rp&>::get_future()
-{
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    return future<_Rp&>(__state_);
-}
-
-template <class _Rp>
-void
-promise<_Rp&>::set_value(_Rp& __r)
-{
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_value(__r);
-}
-
-template <class _Rp>
-void
-promise<_Rp&>::set_exception(exception_ptr __p)
-{
-    _LIBCPP_ASSERT( __p != nullptr, "promise::set_exception: received nullptr" );
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_exception(__p);
-}
-
-template <class _Rp>
-void
-promise<_Rp&>::set_value_at_thread_exit(_Rp& __r)
-{
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_value_at_thread_exit(__r);
-}
-
-template <class _Rp>
-void
-promise<_Rp&>::set_exception_at_thread_exit(exception_ptr __p)
-{
-    _LIBCPP_ASSERT( __p != nullptr, "promise::set_exception_at_thread_exit: received nullptr" );
-    if (__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    __state_->set_exception_at_thread_exit(__p);
-}
-
-// promise<void>
-
-template <>
-class _LIBCPP_TYPE_VIS _LIBCPP_AVAILABILITY_FUTURE promise<void>
-{
-    __assoc_sub_state* __state_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit promise(nullptr_t) _NOEXCEPT : __state_(nullptr) {}
-
-    template <class> friend class packaged_task;
-
-public:
-    promise();
-    template <class _Allocator>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        promise(allocator_arg_t, const _Allocator& __a);
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    promise(promise&& __rhs) _NOEXCEPT
-        : __state_(__rhs.__state_) {__rhs.__state_ = nullptr;}
-    promise(const promise& __rhs) = delete;
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-private:
-    promise(const promise& __rhs);
-public:
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~promise();
-
-    // assignment
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    promise& operator=(promise&& __rhs) _NOEXCEPT
-        {
-            promise(std::move(__rhs)).swap(*this);
-            return *this;
-        }
-    promise& operator=(const promise& __rhs) = delete;
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-private:
-    promise& operator=(const promise& __rhs);
-public:
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(promise& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
-
-    // retrieving the result
-    future<void> get_future();
-
-    // setting the result
-    void set_value();
-    void set_exception(exception_ptr __p);
-
-    // setting the result with deferred notification
-    void set_value_at_thread_exit();
-    void set_exception_at_thread_exit(exception_ptr __p);
-};
-
-template <class _Alloc>
-promise<void>::promise(allocator_arg_t, const _Alloc& __a0)
-{
-    typedef __assoc_sub_state_alloc<_Alloc> _State;
-    typedef typename __allocator_traits_rebind<_Alloc, _State>::type _A2;
-    typedef __allocator_destructor<_A2> _D2;
-    _A2 __a(__a0);
-    unique_ptr<_State, _D2> __hold(__a.allocate(1), _D2(__a, 1));
-    ::new(static_cast<void*>(_VSTD::addressof(*__hold.get()))) _State(__a0);
-    __state_ = _VSTD::addressof(*__hold.release());
-}
-
-template <class _Rp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(promise<_Rp>& __x, promise<_Rp>& __y) _NOEXCEPT
-{
-    __x.swap(__y);
-}
-
-template <class _Rp, class _Alloc>
-    struct _LIBCPP_TEMPLATE_VIS uses_allocator<promise<_Rp>, _Alloc>
-        : public true_type {};
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-// packaged_task
-
-template<class _Fp> class __packaged_task_base;
-
-template<class _Rp, class ..._ArgTypes>
-class _LIBCPP_AVAILABILITY_FUTURE __packaged_task_base<_Rp(_ArgTypes...)>
-{
-    __packaged_task_base(const __packaged_task_base&);
-    __packaged_task_base& operator=(const __packaged_task_base&);
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __packaged_task_base() {}
-    _LIBCPP_INLINE_VISIBILITY
-    virtual ~__packaged_task_base() {}
-    virtual void __move_to(__packaged_task_base*) _NOEXCEPT = 0;
-    virtual void destroy() = 0;
-    virtual void destroy_deallocate() = 0;
-    virtual _Rp operator()(_ArgTypes&& ...) = 0;
-};
-
-template<class _FD, class _Alloc, class _FB> class __packaged_task_func;
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-class _LIBCPP_AVAILABILITY_FUTURE __packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>
-    : public  __packaged_task_base<_Rp(_ArgTypes...)>
-{
-    __compressed_pair<_Fp, _Alloc> __f_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __packaged_task_func(const _Fp& __f) : __f_(__f) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __packaged_task_func(_Fp&& __f) : __f_(_VSTD::move(__f)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __packaged_task_func(const _Fp& __f, const _Alloc& __a)
-        : __f_(__f, __a) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __packaged_task_func(_Fp&& __f, const _Alloc& __a)
-        : __f_(_VSTD::move(__f), __a) {}
-    virtual void __move_to(__packaged_task_base<_Rp(_ArgTypes...)>*) _NOEXCEPT;
-    virtual void destroy();
-    virtual void destroy_deallocate();
-    virtual _Rp operator()(_ArgTypes&& ... __args);
-};
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-void
-__packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::__move_to(
-                              __packaged_task_base<_Rp(_ArgTypes...)>* __p) _NOEXCEPT
-{
-    ::new (__p) __packaged_task_func(_VSTD::move(__f_.first()), _VSTD::move(__f_.second()));
-}
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-void
-__packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy()
-{
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-}
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-void
-__packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::destroy_deallocate()
-{
-    typedef typename __allocator_traits_rebind<_Alloc, __packaged_task_func>::type _Ap;
-    typedef allocator_traits<_Ap> _ATraits;
-    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
-    _Ap __a(__f_.second());
-    __f_.~__compressed_pair<_Fp, _Alloc>();
-    __a.deallocate(_PTraits::pointer_to(*this), 1);
-}
-
-template<class _Fp, class _Alloc, class _Rp, class ..._ArgTypes>
-_Rp
-__packaged_task_func<_Fp, _Alloc, _Rp(_ArgTypes...)>::operator()(_ArgTypes&& ... __arg)
-{
-    return __invoke(__f_.first(), _VSTD::forward<_ArgTypes>(__arg)...);
-}
-
-template <class _Callable> class __packaged_task_function;
-
-template<class _Rp, class ..._ArgTypes>
-class _LIBCPP_AVAILABILITY_FUTURE __packaged_task_function<_Rp(_ArgTypes...)>
-{
-    typedef __packaged_task_base<_Rp(_ArgTypes...)> __base;
-    typename aligned_storage<3*sizeof(void*)>::type __buf_;
-    __base* __f_;
-
-public:
-    typedef _Rp result_type;
-
-    // construct/copy/destroy:
-    _LIBCPP_INLINE_VISIBILITY
-    __packaged_task_function() _NOEXCEPT : __f_(nullptr) {}
-    template<class _Fp>
-      __packaged_task_function(_Fp&& __f);
-    template<class _Fp, class _Alloc>
-      __packaged_task_function(allocator_arg_t, const _Alloc& __a, _Fp&& __f);
-
-    __packaged_task_function(__packaged_task_function&&) _NOEXCEPT;
-    __packaged_task_function& operator=(__packaged_task_function&&) _NOEXCEPT;
-
-    __packaged_task_function(const __packaged_task_function&) =  delete;
-    __packaged_task_function& operator=(const __packaged_task_function&) =  delete;
-
-    ~__packaged_task_function();
-
-    void swap(__packaged_task_function&) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Rp operator()(_ArgTypes...) const;
-};
-
-template<class _Rp, class ..._ArgTypes>
-__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(__packaged_task_function&& __f) _NOEXCEPT
-{
-    if (__f.__f_ == nullptr)
-        __f_ = nullptr;
-    else if (__f.__f_ == (__base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__move_to(__f_);
-    }
-    else
-    {
-        __f_ = __f.__f_;
-        __f.__f_ = nullptr;
-    }
-}
-
-template<class _Rp, class ..._ArgTypes>
-template <class _Fp>
-__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(_Fp&& __f)
-    : __f_(nullptr)
-{
-    typedef typename remove_reference<typename decay<_Fp>::type>::type _FR;
-    typedef __packaged_task_func<_FR, allocator<_FR>, _Rp(_ArgTypes...)> _FF;
-    if (sizeof(_FF) <= sizeof(__buf_))
-    {
-        __f_ = (__base*)&__buf_;
-        ::new (__f_) _FF(_VSTD::forward<_Fp>(__f));
-    }
-    else
-    {
-        typedef allocator<_FF> _Ap;
-        _Ap __a;
-        typedef __allocator_destructor<_Ap> _Dp;
-        unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-        ::new (__hold.get()) _FF(_VSTD::forward<_Fp>(__f), allocator<_FR>(__a));
-        __f_ = __hold.release();
-    }
-}
-
-template<class _Rp, class ..._ArgTypes>
-template <class _Fp, class _Alloc>
-__packaged_task_function<_Rp(_ArgTypes...)>::__packaged_task_function(
-                                  allocator_arg_t, const _Alloc& __a0, _Fp&& __f)
-    : __f_(nullptr)
-{
-    typedef typename remove_reference<typename decay<_Fp>::type>::type _FR;
-    typedef __packaged_task_func<_FR, _Alloc, _Rp(_ArgTypes...)> _FF;
-    if (sizeof(_FF) <= sizeof(__buf_))
-    {
-        __f_ = (__base*)&__buf_;
-        ::new (__f_) _FF(_VSTD::forward<_Fp>(__f));
-    }
-    else
-    {
-        typedef typename __allocator_traits_rebind<_Alloc, _FF>::type _Ap;
-        _Ap __a(__a0);
-        typedef __allocator_destructor<_Ap> _Dp;
-        unique_ptr<__base, _Dp> __hold(__a.allocate(1), _Dp(__a, 1));
-        ::new (static_cast<void*>(_VSTD::addressof(*__hold.get())))
-            _FF(_VSTD::forward<_Fp>(__f), _Alloc(__a));
-        __f_ = _VSTD::addressof(*__hold.release());
-    }
-}
-
-template<class _Rp, class ..._ArgTypes>
-__packaged_task_function<_Rp(_ArgTypes...)>&
-__packaged_task_function<_Rp(_ArgTypes...)>::operator=(__packaged_task_function&& __f) _NOEXCEPT
-{
-    if (__f_ == (__base*)&__buf_)
-        __f_->destroy();
-    else if (__f_)
-        __f_->destroy_deallocate();
-    __f_ = nullptr;
-    if (__f.__f_ == nullptr)
-        __f_ = nullptr;
-    else if (__f.__f_ == (__base*)&__f.__buf_)
-    {
-        __f_ = (__base*)&__buf_;
-        __f.__f_->__move_to(__f_);
-    }
-    else
-    {
-        __f_ = __f.__f_;
-        __f.__f_ = nullptr;
-    }
-    return *this;
-}
-
-template<class _Rp, class ..._ArgTypes>
-__packaged_task_function<_Rp(_ArgTypes...)>::~__packaged_task_function()
-{
-    if (__f_ == (__base*)&__buf_)
-        __f_->destroy();
-    else if (__f_)
-        __f_->destroy_deallocate();
-}
-
-template<class _Rp, class ..._ArgTypes>
-void
-__packaged_task_function<_Rp(_ArgTypes...)>::swap(__packaged_task_function& __f) _NOEXCEPT
-{
-    if (__f_ == (__base*)&__buf_ && __f.__f_ == (__base*)&__f.__buf_)
-    {
-        typename aligned_storage<sizeof(__buf_)>::type __tempbuf;
-        __base* __t = (__base*)&__tempbuf;
-        __f_->__move_to(__t);
-        __f_->destroy();
-        __f_ = nullptr;
-        __f.__f_->__move_to((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = nullptr;
-        __f_ = (__base*)&__buf_;
-        __t->__move_to((__base*)&__f.__buf_);
-        __t->destroy();
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f_ == (__base*)&__buf_)
-    {
-        __f_->__move_to((__base*)&__f.__buf_);
-        __f_->destroy();
-        __f_ = __f.__f_;
-        __f.__f_ = (__base*)&__f.__buf_;
-    }
-    else if (__f.__f_ == (__base*)&__f.__buf_)
-    {
-        __f.__f_->__move_to((__base*)&__buf_);
-        __f.__f_->destroy();
-        __f.__f_ = __f_;
-        __f_ = (__base*)&__buf_;
-    }
-    else
-        _VSTD::swap(__f_, __f.__f_);
-}
-
-template<class _Rp, class ..._ArgTypes>
-inline
-_Rp
-__packaged_task_function<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __arg) const
-{
-    return (*__f_)(_VSTD::forward<_ArgTypes>(__arg)...);
-}
-
-template<class _Rp, class ..._ArgTypes>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FUTURE packaged_task<_Rp(_ArgTypes...)>
-{
-public:
-    typedef _Rp result_type; // extension
-
-private:
-    __packaged_task_function<result_type(_ArgTypes...)> __f_;
-    promise<result_type>                                __p_;
-
-public:
-    // construction and destruction
-    _LIBCPP_INLINE_VISIBILITY
-    packaged_task() _NOEXCEPT : __p_(nullptr) {}
-    template <class _Fp,
-              class = typename enable_if
-              <
-                  !is_same<
-                      typename __uncvref<_Fp>::type, 
-                      packaged_task
-                      >::value
-                  >::type
-             >
-        _LIBCPP_INLINE_VISIBILITY
-        explicit packaged_task(_Fp&& __f) : __f_(_VSTD::forward<_Fp>(__f)) {}
-    template <class _Fp, class _Allocator,
-              class = typename enable_if
-              <
-                  !is_same<
-                      typename __uncvref<_Fp>::type, 
-                      packaged_task
-                      >::value
-                  >::type
-              >
-        _LIBCPP_INLINE_VISIBILITY
-        packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
-             : __f_(allocator_arg, __a, _VSTD::forward<_Fp>(__f)),
-               __p_(allocator_arg, __a) {}
-    // ~packaged_task() = default;
-
-    // no copy
-    packaged_task(const packaged_task&) = delete;
-    packaged_task& operator=(const packaged_task&) = delete;
-
-    // move support
-    _LIBCPP_INLINE_VISIBILITY
-    packaged_task(packaged_task&& __other) _NOEXCEPT
-        : __f_(_VSTD::move(__other.__f_)), __p_(_VSTD::move(__other.__p_)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    packaged_task& operator=(packaged_task&& __other) _NOEXCEPT
-    {
-        __f_ = _VSTD::move(__other.__f_);
-        __p_ = _VSTD::move(__other.__p_);
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(packaged_task& __other) _NOEXCEPT
-    {
-        __f_.swap(__other.__f_);
-        __p_.swap(__other.__p_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool valid() const _NOEXCEPT {return __p_.__state_ != nullptr;}
-
-    // result retrieval
-    _LIBCPP_INLINE_VISIBILITY
-    future<result_type> get_future() {return __p_.get_future();}
-
-    // execution
-    void operator()(_ArgTypes... __args);
-    void make_ready_at_thread_exit(_ArgTypes... __args);
-
-    void reset();
-};
-
-template<class _Rp, class ..._ArgTypes>
-void
-packaged_task<_Rp(_ArgTypes...)>::operator()(_ArgTypes... __args)
-{
-    if (__p_.__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    if (__p_.__state_->__has_value())
-        __throw_future_error(future_errc::promise_already_satisfied);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __p_.set_value(__f_(_VSTD::forward<_ArgTypes>(__args)...));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __p_.set_exception(current_exception());
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template<class _Rp, class ..._ArgTypes>
-void
-packaged_task<_Rp(_ArgTypes...)>::make_ready_at_thread_exit(_ArgTypes... __args)
-{
-    if (__p_.__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    if (__p_.__state_->__has_value())
-        __throw_future_error(future_errc::promise_already_satisfied);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __p_.set_value_at_thread_exit(__f_(_VSTD::forward<_ArgTypes>(__args)...));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __p_.set_exception_at_thread_exit(current_exception());
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template<class _Rp, class ..._ArgTypes>
-void
-packaged_task<_Rp(_ArgTypes...)>::reset()
-{
-    if (!valid())
-        __throw_future_error(future_errc::no_state);
-    __p_ = promise<result_type>();
-}
-
-template<class ..._ArgTypes>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_AVAILABILITY_FUTURE packaged_task<void(_ArgTypes...)>
-{
-public:
-    typedef void result_type; // extension
-
-private:
-    __packaged_task_function<result_type(_ArgTypes...)> __f_;
-    promise<result_type>                                __p_;
-
-public:
-    // construction and destruction
-    _LIBCPP_INLINE_VISIBILITY
-    packaged_task() _NOEXCEPT : __p_(nullptr) {}
-    template <class _Fp,
-              class = typename enable_if
-              <
-                  !is_same<
-                      typename __uncvref<_Fp>::type, 
-                      packaged_task
-                      >::value
-                  >::type
-              >
-        _LIBCPP_INLINE_VISIBILITY
-        explicit packaged_task(_Fp&& __f) : __f_(_VSTD::forward<_Fp>(__f)) {}
-    template <class _Fp, class _Allocator,
-              class = typename enable_if
-              <
-                  !is_same<
-                      typename __uncvref<_Fp>::type, 
-                      packaged_task
-                      >::value
-                  >::type
-              >    
-        _LIBCPP_INLINE_VISIBILITY
-        packaged_task(allocator_arg_t, const _Allocator& __a, _Fp&& __f)
-             : __f_(allocator_arg, __a, _VSTD::forward<_Fp>(__f)),
-               __p_(allocator_arg, __a) {}
-    // ~packaged_task() = default;
-
-    // no copy
-    packaged_task(const packaged_task&) = delete;
-    packaged_task& operator=(const packaged_task&) = delete;
-
-    // move support
-    _LIBCPP_INLINE_VISIBILITY
-    packaged_task(packaged_task&& __other) _NOEXCEPT
-        : __f_(_VSTD::move(__other.__f_)), __p_(_VSTD::move(__other.__p_)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    packaged_task& operator=(packaged_task&& __other) _NOEXCEPT
-    {
-        __f_ = _VSTD::move(__other.__f_);
-        __p_ = _VSTD::move(__other.__p_);
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(packaged_task& __other) _NOEXCEPT
-    {
-        __f_.swap(__other.__f_);
-        __p_.swap(__other.__p_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool valid() const _NOEXCEPT {return __p_.__state_ != nullptr;}
-
-    // result retrieval
-    _LIBCPP_INLINE_VISIBILITY
-    future<result_type> get_future() {return __p_.get_future();}
-
-    // execution
-    void operator()(_ArgTypes... __args);
-    void make_ready_at_thread_exit(_ArgTypes... __args);
-
-    void reset();
-};
-
-template<class ..._ArgTypes>
-void
-packaged_task<void(_ArgTypes...)>::operator()(_ArgTypes... __args)
-{
-    if (__p_.__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    if (__p_.__state_->__has_value())
-        __throw_future_error(future_errc::promise_already_satisfied);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __f_(_VSTD::forward<_ArgTypes>(__args)...);
-        __p_.set_value();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __p_.set_exception(current_exception());
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template<class ..._ArgTypes>
-void
-packaged_task<void(_ArgTypes...)>::make_ready_at_thread_exit(_ArgTypes... __args)
-{
-    if (__p_.__state_ == nullptr)
-        __throw_future_error(future_errc::no_state);
-    if (__p_.__state_->__has_value())
-        __throw_future_error(future_errc::promise_already_satisfied);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __f_(_VSTD::forward<_ArgTypes>(__args)...);
-        __p_.set_value_at_thread_exit();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __p_.set_exception_at_thread_exit(current_exception());
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template<class ..._ArgTypes>
-void
-packaged_task<void(_ArgTypes...)>::reset()
-{
-    if (!valid())
-        __throw_future_error(future_errc::no_state);
-    __p_ = promise<result_type>();
-}
-
-template <class _Callable>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(packaged_task<_Callable>& __x, packaged_task<_Callable>& __y) _NOEXCEPT
-{
-    __x.swap(__y);
-}
-
-template <class _Callable, class _Alloc>
-struct _LIBCPP_TEMPLATE_VIS uses_allocator<packaged_task<_Callable>, _Alloc>
-    : public true_type {};
-
-template <class _Rp, class _Fp>
-future<_Rp>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-__make_deferred_assoc_state(_Fp&& __f)
-#else
-__make_deferred_assoc_state(_Fp __f)
-#endif
-{
-    unique_ptr<__deferred_assoc_state<_Rp, _Fp>, __release_shared_count>
-        __h(new __deferred_assoc_state<_Rp, _Fp>(_VSTD::forward<_Fp>(__f)));
-    return future<_Rp>(__h.get());
-}
-
-template <class _Rp, class _Fp>
-future<_Rp>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-__make_async_assoc_state(_Fp&& __f)
-#else
-__make_async_assoc_state(_Fp __f)
-#endif
-{
-    unique_ptr<__async_assoc_state<_Rp, _Fp>, __release_shared_count>
-        __h(new __async_assoc_state<_Rp, _Fp>(_VSTD::forward<_Fp>(__f)));
-    _VSTD::thread(&__async_assoc_state<_Rp, _Fp>::__execute, __h.get()).detach();
-    return future<_Rp>(__h.get());
-}
-
-template <class _Fp, class... _Args>
-class __async_func
-{
-    tuple<_Fp, _Args...> __f_;
-
-public:
-    typedef typename __invoke_of<_Fp, _Args...>::type _Rp;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __async_func(_Fp&& __f, _Args&&... __args)
-        : __f_(_VSTD::move(__f), _VSTD::move(__args)...) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __async_func(__async_func&& __f) : __f_(_VSTD::move(__f.__f_)) {}
-
-    _Rp operator()()
-    {
-        typedef typename __make_tuple_indices<1+sizeof...(_Args), 1>::type _Index;
-        return __execute(_Index());
-    }
-private:
-    template <size_t ..._Indices>
-    _Rp
-    __execute(__tuple_indices<_Indices...>)
-    {
-        return __invoke(_VSTD::move(_VSTD::get<0>(__f_)), _VSTD::move(_VSTD::get<_Indices>(__f_))...);
-    }
-};
-
-inline _LIBCPP_INLINE_VISIBILITY bool __does_policy_contain(launch __policy, launch __value )
-{ return (int(__policy) & int(__value)) != 0; }
-
-template <class _Fp, class... _Args>
-_LIBCPP_NODISCARD_AFTER_CXX17
-future<typename __invoke_of<typename decay<_Fp>::type, typename decay<_Args>::type...>::type>
-async(launch __policy, _Fp&& __f, _Args&&... __args)
-{
-    typedef __async_func<typename decay<_Fp>::type, typename decay<_Args>::type...> _BF;
-    typedef typename _BF::_Rp _Rp;
-
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif
-        if (__does_policy_contain(__policy, launch::async))
-        return _VSTD::__make_async_assoc_state<_Rp>(_BF(__decay_copy(_VSTD::forward<_Fp>(__f)),
-                                                     __decay_copy(_VSTD::forward<_Args>(__args))...));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch ( ... ) { if (__policy == launch::async) throw ; }
-#endif
-
-    if (__does_policy_contain(__policy, launch::deferred))
-        return _VSTD::__make_deferred_assoc_state<_Rp>(_BF(__decay_copy(_VSTD::forward<_Fp>(__f)),
-                                                        __decay_copy(_VSTD::forward<_Args>(__args))...));
-    return future<_Rp>{};
-}
-
-template <class _Fp, class... _Args>
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
-future<typename __invoke_of<typename decay<_Fp>::type, typename decay<_Args>::type...>::type>
-async(_Fp&& __f, _Args&&... __args)
-{
-    return _VSTD::async(launch::any, _VSTD::forward<_Fp>(__f),
-                                    _VSTD::forward<_Args>(__args)...);
-}
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-// shared_future
-
-template <class _Rp>
-class _LIBCPP_TEMPLATE_VIS shared_future
-{
-    __assoc_state<_Rp>* __state_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future() _NOEXCEPT : __state_(nullptr) {}
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future(const shared_future& __rhs)  _NOEXCEPT : __state_(__rhs.__state_)
-        {if (__state_) __state_->__add_shared();}
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future(future<_Rp>&& __f) _NOEXCEPT : __state_(__f.__state_)
-        {__f.__state_ = nullptr;}
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_)
-        {__rhs.__state_ = nullptr;}
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~shared_future();
-    shared_future& operator=(const shared_future& __rhs) _NOEXCEPT;
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future& operator=(shared_future&& __rhs) _NOEXCEPT
-        {
-            shared_future(std::move(__rhs)).swap(*this);
-            return *this;
-        }
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-    // retrieving the value
-    _LIBCPP_INLINE_VISIBILITY
-    const _Rp& get() const {return __state_->copy();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(shared_future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
-
-    // functions to check state
-    _LIBCPP_INLINE_VISIBILITY
-    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void wait() const {__state_->wait();}
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
-            {return __state_->wait_for(__rel_time);}
-    template <class _Clock, class _Duration>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
-            {return __state_->wait_until(__abs_time);}
-};
-
-template <class _Rp>
-shared_future<_Rp>::~shared_future()
-{
-    if (__state_)
-        __state_->__release_shared();
-}
-
-template <class _Rp>
-shared_future<_Rp>&
-shared_future<_Rp>::operator=(const shared_future& __rhs) _NOEXCEPT
-{
-    if (__rhs.__state_)
-        __rhs.__state_->__add_shared();
-    if (__state_)
-        __state_->__release_shared();
-    __state_ = __rhs.__state_;
-    return *this;
-}
-
-template <class _Rp>
-class _LIBCPP_TEMPLATE_VIS shared_future<_Rp&>
-{
-    __assoc_state<_Rp&>* __state_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future() _NOEXCEPT : __state_(nullptr) {}
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future(const shared_future& __rhs) : __state_(__rhs.__state_)
-        {if (__state_) __state_->__add_shared();}
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future(future<_Rp&>&& __f) _NOEXCEPT : __state_(__f.__state_)
-        {__f.__state_ = nullptr;}
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_)
-        {__rhs.__state_ = nullptr;}
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~shared_future();
-    shared_future& operator=(const shared_future& __rhs);
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future& operator=(shared_future&& __rhs) _NOEXCEPT
-        {
-            shared_future(std::move(__rhs)).swap(*this);
-            return *this;
-        }
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-    // retrieving the value
-    _LIBCPP_INLINE_VISIBILITY
-    _Rp& get() const {return __state_->copy();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(shared_future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
-
-    // functions to check state
-    _LIBCPP_INLINE_VISIBILITY
-    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void wait() const {__state_->wait();}
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
-            {return __state_->wait_for(__rel_time);}
-    template <class _Clock, class _Duration>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
-            {return __state_->wait_until(__abs_time);}
-};
-
-template <class _Rp>
-shared_future<_Rp&>::~shared_future()
-{
-    if (__state_)
-        __state_->__release_shared();
-}
-
-template <class _Rp>
-shared_future<_Rp&>&
-shared_future<_Rp&>::operator=(const shared_future& __rhs)
-{
-    if (__rhs.__state_)
-        __rhs.__state_->__add_shared();
-    if (__state_)
-        __state_->__release_shared();
-    __state_ = __rhs.__state_;
-    return *this;
-}
-
-template <>
-class _LIBCPP_TYPE_VIS _LIBCPP_AVAILABILITY_FUTURE shared_future<void>
-{
-    __assoc_sub_state* __state_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future() _NOEXCEPT : __state_(nullptr) {}
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future(const shared_future& __rhs) : __state_(__rhs.__state_)
-        {if (__state_) __state_->__add_shared();}
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future(future<void>&& __f) _NOEXCEPT : __state_(__f.__state_)
-        {__f.__state_ = nullptr;}
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future(shared_future&& __rhs) _NOEXCEPT : __state_(__rhs.__state_)
-        {__rhs.__state_ = nullptr;}
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~shared_future();
-    shared_future& operator=(const shared_future& __rhs);
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    shared_future& operator=(shared_future&& __rhs) _NOEXCEPT
-        {
-            shared_future(std::move(__rhs)).swap(*this);
-            return *this;
-        }
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-    // retrieving the value
-    _LIBCPP_INLINE_VISIBILITY
-    void get() const {__state_->copy();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(shared_future& __rhs) _NOEXCEPT {_VSTD::swap(__state_, __rhs.__state_);}
-
-    // functions to check state
-    _LIBCPP_INLINE_VISIBILITY
-    bool valid() const _NOEXCEPT {return __state_ != nullptr;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void wait() const {__state_->wait();}
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_for(const chrono::duration<_Rep, _Period>& __rel_time) const
-            {return __state_->wait_for(__rel_time);}
-    template <class _Clock, class _Duration>
-        _LIBCPP_INLINE_VISIBILITY
-        future_status
-        wait_until(const chrono::time_point<_Clock, _Duration>& __abs_time) const
-            {return __state_->wait_until(__abs_time);}
-};
-
-template <class _Rp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(shared_future<_Rp>& __x, shared_future<_Rp>& __y) _NOEXCEPT
-{
-    __x.swap(__y);
-}
-
-template <class _Rp>
-inline
-shared_future<_Rp>
-future<_Rp>::share() _NOEXCEPT
-{
-    return shared_future<_Rp>(_VSTD::move(*this));
-}
-
-template <class _Rp>
-inline
-shared_future<_Rp&>
-future<_Rp&>::share() _NOEXCEPT
-{
-    return shared_future<_Rp&>(_VSTD::move(*this));
-}
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-inline
-shared_future<void>
-future<void>::share() _NOEXCEPT
-{
-    return shared_future<void>(_VSTD::move(*this));
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // !_LIBCPP_HAS_NO_THREADS
-
-#endif  // _LIBCPP_FUTURE
diff --git a/lib/libcxx/include/initializer_list b/lib/libcxx/include/initializer_list
deleted file mode 100644
index b934637b83d..00000000000
--- a/lib/libcxx/include/initializer_list
+++ /dev/null
@@ -1,118 +0,0 @@
-// -*- C++ -*-
-//===----------------------- initializer_list -----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_INITIALIZER_LIST
-#define _LIBCPP_INITIALIZER_LIST
-
-/*
-    initializer_list synopsis
-
-namespace std
-{
-
-template<class E>
-class initializer_list
-{
-public:
-    typedef E        value_type;
-    typedef const E& reference;
-    typedef const E& const_reference;
-    typedef size_t   size_type;
-
-    typedef const E* iterator;
-    typedef const E* const_iterator;
-
-    initializer_list() noexcept; // constexpr in C++14
-
-    size_t   size()  const noexcept; // constexpr in C++14
-    const E* begin() const noexcept; // constexpr in C++14
-    const E* end()   const noexcept; // constexpr in C++14
-};
-
-template<class E> const E* begin(initializer_list<E> il) noexcept; // constexpr in C++14
-template<class E> const E* end(initializer_list<E> il) noexcept; // constexpr in C++14
-
-}  // std
-
-*/
-
-#include <__config>
-#include <cstddef>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-namespace std  // purposefully not versioned
-{
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Ep>
-class _LIBCPP_TEMPLATE_VIS initializer_list
-{
-    const _Ep* __begin_;
-    size_t    __size_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
-    initializer_list(const _Ep* __b, size_t __s) _NOEXCEPT
-        : __begin_(__b),
-          __size_(__s)
-        {}
-public:
-    typedef _Ep        value_type;
-    typedef const _Ep& reference;
-    typedef const _Ep& const_reference;
-    typedef size_t    size_type;
-
-    typedef const _Ep* iterator;
-    typedef const _Ep* const_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
-    initializer_list() _NOEXCEPT : __begin_(nullptr), __size_(0) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
-    size_t    size()  const _NOEXCEPT {return __size_;}
-    
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const _Ep* begin() const _NOEXCEPT {return __begin_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const _Ep* end()   const _NOEXCEPT {return __begin_ + __size_;}
-};
-
-template<class _Ep>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Ep*
-begin(initializer_list<_Ep> __il) _NOEXCEPT
-{
-    return __il.begin();
-}
-
-template<class _Ep>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR_AFTER_CXX11
-const _Ep*
-end(initializer_list<_Ep> __il) _NOEXCEPT
-{
-    return __il.end();
-}
-
-#endif  // !defined(_LIBCPP_CXX03_LANG)
-
-}  // std
-
-#endif  // _LIBCPP_INITIALIZER_LIST
diff --git a/lib/libcxx/include/inttypes.h b/lib/libcxx/include/inttypes.h
deleted file mode 100644
index 058f54b5161..00000000000
--- a/lib/libcxx/include/inttypes.h
+++ /dev/null
@@ -1,258 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- inttypes.h -------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_INTTYPES_H
-#define _LIBCPP_INTTYPES_H
-
-/*
-    inttypes.h synopsis
-
-This entire header is C99 / C++0X
-
-#include <stdint.h>  // <cinttypes> includes <cstdint>
-
-Macros:
-
-    PRId8
-    PRId16
-    PRId32
-    PRId64
-
-    PRIdLEAST8
-    PRIdLEAST16
-    PRIdLEAST32
-    PRIdLEAST64
-
-    PRIdFAST8
-    PRIdFAST16
-    PRIdFAST32
-    PRIdFAST64
-
-    PRIdMAX
-    PRIdPTR
-
-    PRIi8
-    PRIi16
-    PRIi32
-    PRIi64
-
-    PRIiLEAST8
-    PRIiLEAST16
-    PRIiLEAST32
-    PRIiLEAST64
-
-    PRIiFAST8
-    PRIiFAST16
-    PRIiFAST32
-    PRIiFAST64
-
-    PRIiMAX
-    PRIiPTR
-
-    PRIo8
-    PRIo16
-    PRIo32
-    PRIo64
-
-    PRIoLEAST8
-    PRIoLEAST16
-    PRIoLEAST32
-    PRIoLEAST64
-
-    PRIoFAST8
-    PRIoFAST16
-    PRIoFAST32
-    PRIoFAST64
-
-    PRIoMAX
-    PRIoPTR
-
-    PRIu8
-    PRIu16
-    PRIu32
-    PRIu64
-
-    PRIuLEAST8
-    PRIuLEAST16
-    PRIuLEAST32
-    PRIuLEAST64
-
-    PRIuFAST8
-    PRIuFAST16
-    PRIuFAST32
-    PRIuFAST64
-
-    PRIuMAX
-    PRIuPTR
-
-    PRIx8
-    PRIx16
-    PRIx32
-    PRIx64
-
-    PRIxLEAST8
-    PRIxLEAST16
-    PRIxLEAST32
-    PRIxLEAST64
-
-    PRIxFAST8
-    PRIxFAST16
-    PRIxFAST32
-    PRIxFAST64
-
-    PRIxMAX
-    PRIxPTR
-
-    PRIX8
-    PRIX16
-    PRIX32
-    PRIX64
-
-    PRIXLEAST8
-    PRIXLEAST16
-    PRIXLEAST32
-    PRIXLEAST64
-
-    PRIXFAST8
-    PRIXFAST16
-    PRIXFAST32
-    PRIXFAST64
-
-    PRIXMAX
-    PRIXPTR
-
-    SCNd8
-    SCNd16
-    SCNd32
-    SCNd64
-
-    SCNdLEAST8
-    SCNdLEAST16
-    SCNdLEAST32
-    SCNdLEAST64
-
-    SCNdFAST8
-    SCNdFAST16
-    SCNdFAST32
-    SCNdFAST64
-
-    SCNdMAX
-    SCNdPTR
-
-    SCNi8
-    SCNi16
-    SCNi32
-    SCNi64
-
-    SCNiLEAST8
-    SCNiLEAST16
-    SCNiLEAST32
-    SCNiLEAST64
-
-    SCNiFAST8
-    SCNiFAST16
-    SCNiFAST32
-    SCNiFAST64
-
-    SCNiMAX
-    SCNiPTR
-
-    SCNo8
-    SCNo16
-    SCNo32
-    SCNo64
-
-    SCNoLEAST8
-    SCNoLEAST16
-    SCNoLEAST32
-    SCNoLEAST64
-
-    SCNoFAST8
-    SCNoFAST16
-    SCNoFAST32
-    SCNoFAST64
-
-    SCNoMAX
-    SCNoPTR
-
-    SCNu8
-    SCNu16
-    SCNu32
-    SCNu64
-
-    SCNuLEAST8
-    SCNuLEAST16
-    SCNuLEAST32
-    SCNuLEAST64
-
-    SCNuFAST8
-    SCNuFAST16
-    SCNuFAST32
-    SCNuFAST64
-
-    SCNuMAX
-    SCNuPTR
-
-    SCNx8
-    SCNx16
-    SCNx32
-    SCNx64
-
-    SCNxLEAST8
-    SCNxLEAST16
-    SCNxLEAST32
-    SCNxLEAST64
-
-    SCNxFAST8
-    SCNxFAST16
-    SCNxFAST32
-    SCNxFAST64
-
-    SCNxMAX
-    SCNxPTR
-
-Types:
-
-    imaxdiv_t
-
-intmax_t  imaxabs(intmax_t j);
-imaxdiv_t imaxdiv(intmax_t numer, intmax_t denom);
-intmax_t  strtoimax(const char* restrict nptr, char** restrict endptr, int base);
-uintmax_t strtoumax(const char* restrict nptr, char** restrict endptr, int base);
-intmax_t  wcstoimax(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
-uintmax_t wcstoumax(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-/* C99 stdlib (e.g. glibc < 2.18) does not provide format macros needed
-   for C++11 unless __STDC_FORMAT_MACROS is defined
-*/
-#if defined(__cplusplus) && !defined(__STDC_FORMAT_MACROS)
-#   define __STDC_FORMAT_MACROS
-#endif
-
-#include_next <inttypes.h>
-
-#ifdef __cplusplus
-
-#include <stdint.h>
-
-#undef imaxabs
-#undef imaxdiv
-
-#endif // __cplusplus
-
-#endif  // _LIBCPP_INTTYPES_H
diff --git a/lib/libcxx/include/iomanip b/lib/libcxx/include/iomanip
deleted file mode 100644
index 36c11167a44..00000000000
--- a/lib/libcxx/include/iomanip
+++ /dev/null
@@ -1,671 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- iomanip ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_IOMANIP
-#define _LIBCPP_IOMANIP
-
-/*
-    iomanip synopsis
-
-namespace std {
-
-// types T1, T2, ... are unspecified implementation types
-T1 resetiosflags(ios_base::fmtflags mask);
-T2 setiosflags (ios_base::fmtflags mask);
-T3 setbase(int base);
-template<charT> T4 setfill(charT c);
-T5 setprecision(int n);
-T6 setw(int n);
-template <class moneyT> T7 get_money(moneyT& mon, bool intl = false);
-template <class charT, class moneyT> T8 put_money(const moneyT& mon, bool intl = false);
-template <class charT> T9 get_time(struct tm* tmb, const charT* fmt);
-template <class charT> T10 put_time(const struct tm* tmb, const charT* fmt);
-
-template <class charT>
-  T11 quoted(const charT* s, charT delim=charT('"'), charT escape=charT('\\')); // C++14
-
-template <class charT, class traits, class Allocator>
-  T12 quoted(const basic_string<charT, traits, Allocator>& s,
-             charT delim=charT('"'), charT escape=charT('\\')); // C++14
-
-template <class charT, class traits, class Allocator>
-  T13 quoted(basic_string<charT, traits, Allocator>& s,
-             charT delim=charT('"'), charT escape=charT('\\')); // C++14
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__string>
-#include <istream>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// resetiosflags
-
-class __iom_t1
-{
-    ios_base::fmtflags __mask_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __iom_t1(ios_base::fmtflags __m) : __mask_(__m) {}
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t1& __x)
-    {
-        __is.unsetf(__x.__mask_);
-        return __is;
-    }
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t1& __x)
-    {
-        __os.unsetf(__x.__mask_);
-        return __os;
-    }
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t1
-resetiosflags(ios_base::fmtflags __mask)
-{
-    return __iom_t1(__mask);
-}
-
-// setiosflags
-
-class __iom_t2
-{
-    ios_base::fmtflags __mask_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __iom_t2(ios_base::fmtflags __m) : __mask_(__m) {}
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t2& __x)
-    {
-        __is.setf(__x.__mask_);
-        return __is;
-    }
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t2& __x)
-    {
-        __os.setf(__x.__mask_);
-        return __os;
-    }
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t2
-setiosflags(ios_base::fmtflags __mask)
-{
-    return __iom_t2(__mask);
-}
-
-// setbase
-
-class __iom_t3
-{
-    int __base_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __iom_t3(int __b) : __base_(__b) {}
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t3& __x)
-    {
-        __is.setf(__x.__base_ == 8  ? ios_base::oct :
-                  __x.__base_ == 10 ? ios_base::dec :
-                  __x.__base_ == 16 ? ios_base::hex :
-                  ios_base::fmtflags(0), ios_base::basefield);
-        return __is;
-    }
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t3& __x)
-    {
-        __os.setf(__x.__base_ == 8  ? ios_base::oct :
-                  __x.__base_ == 10 ? ios_base::dec :
-                  __x.__base_ == 16 ? ios_base::hex :
-                  ios_base::fmtflags(0), ios_base::basefield);
-        return __os;
-    }
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t3
-setbase(int __base)
-{
-    return __iom_t3(__base);
-}
-
-// setfill
-
-template<class _CharT>
-class __iom_t4
-{
-    _CharT __fill_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __iom_t4(_CharT __c) : __fill_(__c) {}
-
-    template <class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t4& __x)
-    {
-        __os.fill(__x.__fill_);
-        return __os;
-    }
-};
-
-template<class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t4<_CharT>
-setfill(_CharT __c)
-{
-    return __iom_t4<_CharT>(__c);
-}
-
-// setprecision
-
-class __iom_t5
-{
-    int __n_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __iom_t5(int __n) : __n_(__n) {}
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t5& __x)
-    {
-        __is.precision(__x.__n_);
-        return __is;
-    }
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t5& __x)
-    {
-        __os.precision(__x.__n_);
-        return __os;
-    }
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t5
-setprecision(int __n)
-{
-    return __iom_t5(__n);
-}
-
-// setw
-
-class __iom_t6
-{
-    int __n_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __iom_t6(int __n) : __n_(__n) {}
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t6& __x)
-    {
-        __is.width(__x.__n_);
-        return __is;
-    }
-
-    template <class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t6& __x)
-    {
-        __os.width(__x.__n_);
-        return __os;
-    }
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t6
-setw(int __n)
-{
-    return __iom_t6(__n);
-}
-
-// get_money
-
-template <class _MoneyT> class __iom_t7;
-
-template <class _CharT, class _Traits, class _MoneyT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t7<_MoneyT>& __x);
-
-template <class _MoneyT>
-class __iom_t7
-{
-    _MoneyT& __mon_;
-    bool __intl_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __iom_t7(_MoneyT& __mon, bool __intl)
-        : __mon_(__mon), __intl_(__intl) {}
-
-    template <class _CharT, class _Traits, class _Mp>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t7<_Mp>& __x);
-};
-
-template <class _CharT, class _Traits, class _MoneyT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t7<_MoneyT>& __x)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __s(__is);
-        if (__s)
-        {
-            typedef istreambuf_iterator<_CharT, _Traits> _Ip;
-            typedef money_get<_CharT, _Ip> _Fp;
-            ios_base::iostate __err = ios_base::goodbit;
-            const _Fp& __mf = use_facet<_Fp>(__is.getloc());
-            __mf.get(_Ip(__is), _Ip(), __x.__intl_, __is, __err, __x.__mon_);
-            __is.setstate(__err);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-template <class _MoneyT>
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t7<_MoneyT>
-get_money(_MoneyT& __mon, bool __intl = false)
-{
-    return __iom_t7<_MoneyT>(__mon, __intl);
-}
-
-// put_money
-
-template <class _MoneyT> class __iom_t8;
-
-template <class _CharT, class _Traits, class _MoneyT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t8<_MoneyT>& __x);
-
-template <class _MoneyT>
-class __iom_t8
-{
-    const _MoneyT& __mon_;
-    bool __intl_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __iom_t8(const _MoneyT& __mon, bool __intl)
-        : __mon_(__mon), __intl_(__intl) {}
-
-    template <class _CharT, class _Traits, class _Mp>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t8<_Mp>& __x);
-};
-
-template <class _CharT, class _Traits, class _MoneyT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t8<_MoneyT>& __x)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
-        if (__s)
-        {
-            typedef ostreambuf_iterator<_CharT, _Traits> _Op;
-            typedef money_put<_CharT, _Op> _Fp;
-            const _Fp& __mf = use_facet<_Fp>(__os.getloc());
-            if (__mf.put(_Op(__os), __x.__intl_, __os, __os.fill(), __x.__mon_).failed())
-                __os.setstate(ios_base::badbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __os.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __os;
-}
-
-template <class _MoneyT>
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t8<_MoneyT>
-put_money(const _MoneyT& __mon, bool __intl = false)
-{
-    return __iom_t8<_MoneyT>(__mon, __intl);
-}
-
-// get_time
-
-template <class _CharT> class __iom_t9;
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t9<_CharT>& __x);
-
-template <class _CharT>
-class __iom_t9
-{
-    tm* __tm_;
-    const _CharT* __fmt_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __iom_t9(tm* __tm, const _CharT* __fmt)
-        : __tm_(__tm), __fmt_(__fmt) {}
-
-    template <class _Cp, class _Traits>
-    friend
-    basic_istream<_Cp, _Traits>&
-    operator>>(basic_istream<_Cp, _Traits>& __is, const __iom_t9<_Cp>& __x);
-};
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, const __iom_t9<_CharT>& __x)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __s(__is);
-        if (__s)
-        {
-            typedef istreambuf_iterator<_CharT, _Traits> _Ip;
-            typedef time_get<_CharT, _Ip> _Fp;
-            ios_base::iostate __err = ios_base::goodbit;
-            const _Fp& __tf = use_facet<_Fp>(__is.getloc());
-            __tf.get(_Ip(__is), _Ip(), __is, __err, __x.__tm_,
-                     __x.__fmt_, __x.__fmt_ + _Traits::length(__x.__fmt_));
-            __is.setstate(__err);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t9<_CharT>
-get_time(tm* __tm, const _CharT* __fmt)
-{
-    return __iom_t9<_CharT>(__tm, __fmt);
-}
-
-// put_time
-
-template <class _CharT> class __iom_t10;
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t10<_CharT>& __x);
-
-template <class _CharT>
-class __iom_t10
-{
-    const tm* __tm_;
-    const _CharT* __fmt_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __iom_t10(const tm* __tm, const _CharT* __fmt)
-        : __tm_(__tm), __fmt_(__fmt) {}
-
-    template <class _Cp, class _Traits>
-    friend
-    basic_ostream<_Cp, _Traits>&
-    operator<<(basic_ostream<_Cp, _Traits>& __os, const __iom_t10<_Cp>& __x);
-};
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const __iom_t10<_CharT>& __x)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
-        if (__s)
-        {
-            typedef ostreambuf_iterator<_CharT, _Traits> _Op;
-            typedef time_put<_CharT, _Op> _Fp;
-            const _Fp& __tf = use_facet<_Fp>(__os.getloc());
-            if (__tf.put(_Op(__os), __os, __os.fill(), __x.__tm_,
-                         __x.__fmt_, __x.__fmt_ + _Traits::length(__x.__fmt_)).failed())
-                __os.setstate(ios_base::badbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __os.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __os;
-}
-
-template <class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-__iom_t10<_CharT>
-put_time(const tm* __tm, const _CharT* __fmt)
-{
-    return __iom_t10<_CharT>(__tm, __fmt);
-}
-
-template <class _CharT, class _Traits, class _ForwardIterator>
-std::basic_ostream<_CharT, _Traits> &
-__quoted_output ( basic_ostream<_CharT, _Traits> &__os, 
-        _ForwardIterator __first, _ForwardIterator __last, _CharT __delim, _CharT __escape )
-{
-    _VSTD::basic_string<_CharT, _Traits> __str;
-    __str.push_back(__delim);
-    for ( ; __first != __last; ++ __first )
-    {
-        if (_Traits::eq (*__first, __escape) || _Traits::eq (*__first, __delim))
-            __str.push_back(__escape);
-        __str.push_back(*__first);
-    }
-    __str.push_back(__delim);
-    return __put_character_sequence(__os, __str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _String>
-basic_istream<_CharT, _Traits> &
-__quoted_input ( basic_istream<_CharT, _Traits> &__is, _String & __string, _CharT __delim, _CharT __escape )
-{
-    __string.clear ();
-    _CharT __c;
-    __is >> __c;
-    if ( __is.fail ())
-        return __is;
-
-    if (!_Traits::eq (__c, __delim))    // no delimiter, read the whole string
-    {
-        __is.unget ();
-        __is >> __string;
-        return __is;
-    }
-
-    __save_flags<_CharT, _Traits> sf(__is);
-    noskipws (__is);
-    while (true)
-        {
-        __is >> __c;
-        if ( __is.fail ())
-            break;
-        if (_Traits::eq (__c, __escape))
-        {
-            __is >> __c;
-            if ( __is.fail ())
-                break;
-        }
-        else if (_Traits::eq (__c, __delim))
-            break;
-        __string.push_back ( __c );
-        }
-    return __is;
-}
-
-
-template <class _CharT, class _Traits, class _Iter>
-basic_ostream<_CharT, _Traits>& operator<<(
-         basic_ostream<_CharT, _Traits>& __os, 
-         const __quoted_output_proxy<_CharT, _Iter, _Traits> & __proxy)
-{
-    return __quoted_output (__os, __proxy.__first, __proxy.__last, __proxy.__delim, __proxy.__escape);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-struct __quoted_proxy
-{
-    basic_string<_CharT, _Traits, _Allocator> &__string;
-    _CharT  __delim;
-    _CharT  __escape;
-
-    __quoted_proxy(basic_string<_CharT, _Traits, _Allocator> &__s, _CharT __d, _CharT __e)
-    : __string(__s), __delim(__d), __escape(__e) {}
-};
-
-template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>& operator<<(
-        basic_ostream<_CharT, _Traits>& __os, 
-        const __quoted_proxy<_CharT, _Traits, _Allocator> & __proxy)
-{
-    return __quoted_output (__os, __proxy.__string.cbegin (), __proxy.__string.cend (), __proxy.__delim, __proxy.__escape);
-}
-
-//  extractor for non-const basic_string& proxies
-template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>& operator>>(
-        basic_istream<_CharT, _Traits>& __is, 
-        const __quoted_proxy<_CharT, _Traits, _Allocator> & __proxy)
-{
-    return __quoted_input ( __is, __proxy.__string, __proxy.__delim, __proxy.__escape );
-}
-
-
-template <class _CharT>
-_LIBCPP_INLINE_VISIBILITY
-__quoted_output_proxy<_CharT, const _CharT *>
-quoted ( const _CharT *__s, _CharT __delim = _CharT('"'), _CharT __escape =_CharT('\\'))
-{
-    const _CharT *__end = __s;
-    while ( *__end ) ++__end;
-    return __quoted_output_proxy<_CharT, const _CharT *> ( __s, __end, __delim, __escape );
-}
-
-
-template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_INLINE_VISIBILITY
-__quoted_output_proxy<_CharT, typename basic_string <_CharT, _Traits, _Allocator>::const_iterator>
-__quoted ( const basic_string <_CharT, _Traits, _Allocator> &__s, _CharT __delim = _CharT('"'), _CharT __escape=_CharT('\\'))
-{
-    return __quoted_output_proxy<_CharT,
-            typename basic_string <_CharT, _Traits, _Allocator>::const_iterator>
-                    ( __s.cbegin(), __s.cend (), __delim, __escape );
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_INLINE_VISIBILITY
-__quoted_proxy<_CharT, _Traits, _Allocator>
-__quoted ( basic_string <_CharT, _Traits, _Allocator> &__s, _CharT __delim = _CharT('"'), _CharT __escape=_CharT('\\'))
-{
-    return __quoted_proxy<_CharT, _Traits, _Allocator>( __s, __delim, __escape );
-}
-
-
-#if _LIBCPP_STD_VER > 11
-
-template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_INLINE_VISIBILITY
-__quoted_output_proxy<_CharT, typename basic_string <_CharT, _Traits, _Allocator>::const_iterator>
-quoted ( const basic_string <_CharT, _Traits, _Allocator> &__s, _CharT __delim = _CharT('"'), _CharT __escape=_CharT('\\'))
-{
-    return __quoted(__s, __delim, __escape);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-_LIBCPP_INLINE_VISIBILITY
-__quoted_proxy<_CharT, _Traits, _Allocator>
-quoted ( basic_string <_CharT, _Traits, _Allocator> &__s, _CharT __delim = _CharT('"'), _CharT __escape=_CharT('\\'))
-{
-    return __quoted(__s, __delim, __escape);
-}
-
-template <class _CharT, class _Traits>
-__quoted_output_proxy<_CharT, const _CharT *, _Traits>
-quoted (basic_string_view <_CharT, _Traits> __sv,
-             _CharT __delim = _CharT('"'), _CharT __escape=_CharT('\\'))
-{
-    return __quoted_output_proxy<_CharT, const _CharT *, _Traits> 
-         ( __sv.data(), __sv.data() + __sv.size(), __delim, __escape );
-}
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_IOMANIP
diff --git a/lib/libcxx/include/ios b/lib/libcxx/include/ios
deleted file mode 100644
index 040b2d4e04f..00000000000
--- a/lib/libcxx/include/ios
+++ /dev/null
@@ -1,1048 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- ios -------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_IOS
-#define _LIBCPP_IOS
-
-/*
-    ios synopsis
-
-#include <iosfwd>
-
-namespace std
-{
-
-typedef OFF_T streamoff;
-typedef SZ_T streamsize;
-template <class stateT> class fpos;
-
-class ios_base
-{
-public:
-    class failure;
-
-    typedef T1 fmtflags;
-    static constexpr fmtflags boolalpha;
-    static constexpr fmtflags dec;
-    static constexpr fmtflags fixed;
-    static constexpr fmtflags hex;
-    static constexpr fmtflags internal;
-    static constexpr fmtflags left;
-    static constexpr fmtflags oct;
-    static constexpr fmtflags right;
-    static constexpr fmtflags scientific;
-    static constexpr fmtflags showbase;
-    static constexpr fmtflags showpoint;
-    static constexpr fmtflags showpos;
-    static constexpr fmtflags skipws;
-    static constexpr fmtflags unitbuf;
-    static constexpr fmtflags uppercase;
-    static constexpr fmtflags adjustfield;
-    static constexpr fmtflags basefield;
-    static constexpr fmtflags floatfield;
-
-    typedef T2 iostate;
-    static constexpr iostate badbit;
-    static constexpr iostate eofbit;
-    static constexpr iostate failbit;
-    static constexpr iostate goodbit;
-
-    typedef T3 openmode;
-    static constexpr openmode app;
-    static constexpr openmode ate;
-    static constexpr openmode binary;
-    static constexpr openmode in;
-    static constexpr openmode out;
-    static constexpr openmode trunc;
-
-    typedef T4 seekdir;
-    static constexpr seekdir beg;
-    static constexpr seekdir cur;
-    static constexpr seekdir end;
-
-    class Init;
-
-    // 27.5.2.2 fmtflags state:
-    fmtflags flags() const;
-    fmtflags flags(fmtflags fmtfl);
-    fmtflags setf(fmtflags fmtfl);
-    fmtflags setf(fmtflags fmtfl, fmtflags mask);
-    void unsetf(fmtflags mask);
-
-    streamsize precision() const;
-    streamsize precision(streamsize prec);
-    streamsize width() const;
-    streamsize width(streamsize wide);
-
-    // 27.5.2.3 locales:
-    locale imbue(const locale& loc);
-    locale getloc() const;
-
-    // 27.5.2.5 storage:
-    static int xalloc();
-    long& iword(int index);
-    void*& pword(int index);
-
-    // destructor
-    virtual ~ios_base();
-
-    // 27.5.2.6 callbacks;
-    enum event { erase_event, imbue_event, copyfmt_event };
-    typedef void (*event_callback)(event, ios_base&, int index);
-    void register_callback(event_callback fn, int index);
-
-    ios_base(const ios_base&) = delete;
-    ios_base& operator=(const ios_base&) = delete;
-
-    static bool sync_with_stdio(bool sync = true);
-
-protected:
-    ios_base();
-};
-
-template <class charT, class traits = char_traits<charT> >
-class basic_ios
-    : public ios_base
-{
-public:
-    // types:
-    typedef charT char_type;
-    typedef typename traits::int_type int_type;  // removed in C++17
-    typedef typename traits::pos_type pos_type;  // removed in C++17
-    typedef typename traits::off_type off_type;  // removed in C++17
-    typedef traits traits_type;
-
-    operator unspecified-bool-type() const;
-    bool operator!() const;
-    iostate rdstate() const;
-    void clear(iostate state = goodbit);
-    void setstate(iostate state);
-    bool good() const;
-    bool eof() const;
-    bool fail() const;
-    bool bad() const;
-
-    iostate exceptions() const;
-    void exceptions(iostate except);
-
-    // 27.5.4.1 Constructor/destructor:
-    explicit basic_ios(basic_streambuf<charT,traits>* sb);
-    virtual ~basic_ios();
-
-    // 27.5.4.2 Members:
-    basic_ostream<charT,traits>* tie() const;
-    basic_ostream<charT,traits>* tie(basic_ostream<charT,traits>* tiestr);
-
-    basic_streambuf<charT,traits>* rdbuf() const;
-    basic_streambuf<charT,traits>* rdbuf(basic_streambuf<charT,traits>* sb);
-
-    basic_ios& copyfmt(const basic_ios& rhs);
-
-    char_type fill() const;
-    char_type fill(char_type ch);
-
-    locale imbue(const locale& loc);
-
-    char narrow(char_type c, char dfault) const;
-    char_type widen(char c) const;
-
-    basic_ios(const basic_ios& ) = delete;
-    basic_ios& operator=(const basic_ios&) = delete;
-
-protected:
-    basic_ios();
-    void init(basic_streambuf<charT,traits>* sb);
-    void move(basic_ios& rhs);
-    void swap(basic_ios& rhs) noexcept;
-    void set_rdbuf(basic_streambuf<charT, traits>* sb);
-};
-
-// 27.5.5, manipulators:
-ios_base& boolalpha (ios_base& str);
-ios_base& noboolalpha(ios_base& str);
-ios_base& showbase (ios_base& str);
-ios_base& noshowbase (ios_base& str);
-ios_base& showpoint (ios_base& str);
-ios_base& noshowpoint(ios_base& str);
-ios_base& showpos (ios_base& str);
-ios_base& noshowpos (ios_base& str);
-ios_base& skipws (ios_base& str);
-ios_base& noskipws (ios_base& str);
-ios_base& uppercase (ios_base& str);
-ios_base& nouppercase(ios_base& str);
-ios_base& unitbuf (ios_base& str);
-ios_base& nounitbuf (ios_base& str);
-
-// 27.5.5.2 adjustfield:
-ios_base& internal (ios_base& str);
-ios_base& left (ios_base& str);
-ios_base& right (ios_base& str);
-
-// 27.5.5.3 basefield:
-ios_base& dec (ios_base& str);
-ios_base& hex (ios_base& str);
-ios_base& oct (ios_base& str);
-
-// 27.5.5.4 floatfield:
-ios_base& fixed (ios_base& str);
-ios_base& scientific (ios_base& str);
-ios_base& hexfloat (ios_base& str);
-ios_base& defaultfloat(ios_base& str);
-
-// 27.5.5.5 error reporting:
-enum class io_errc
-{
-    stream = 1
-};
-
-concept_map ErrorCodeEnum<io_errc> { };
-error_code make_error_code(io_errc e) noexcept; 
-error_condition make_error_condition(io_errc e) noexcept; 
-storage-class-specifier const error_category& iostream_category() noexcept;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <iosfwd>
-#include <__locale>
-#include <system_error>
-
-#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
-#include <atomic>     // for __xindex_
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-typedef ptrdiff_t streamsize;
-
-class _LIBCPP_TYPE_VIS ios_base
-{
-public:
-    class _LIBCPP_EXCEPTION_ABI failure;
-
-    typedef unsigned int fmtflags;
-    static const fmtflags boolalpha   = 0x0001;
-    static const fmtflags dec         = 0x0002;
-    static const fmtflags fixed       = 0x0004;
-    static const fmtflags hex         = 0x0008;
-    static const fmtflags internal    = 0x0010;
-    static const fmtflags left        = 0x0020;
-    static const fmtflags oct         = 0x0040;
-    static const fmtflags right       = 0x0080;
-    static const fmtflags scientific  = 0x0100;
-    static const fmtflags showbase    = 0x0200;
-    static const fmtflags showpoint   = 0x0400;
-    static const fmtflags showpos     = 0x0800;
-    static const fmtflags skipws      = 0x1000;
-    static const fmtflags unitbuf     = 0x2000;
-    static const fmtflags uppercase   = 0x4000;
-    static const fmtflags adjustfield = left | right | internal;
-    static const fmtflags basefield   = dec | oct | hex;
-    static const fmtflags floatfield  = scientific | fixed;
-
-    typedef unsigned int iostate;
-    static const iostate badbit  = 0x1;
-    static const iostate eofbit  = 0x2;
-    static const iostate failbit = 0x4;
-    static const iostate goodbit = 0x0;
-
-    typedef unsigned int openmode;
-    static const openmode app    = 0x01;
-    static const openmode ate    = 0x02;
-    static const openmode binary = 0x04;
-    static const openmode in     = 0x08;
-    static const openmode out    = 0x10;
-    static const openmode trunc  = 0x20;
-
-    enum seekdir {beg, cur, end};
-
-#if _LIBCPP_STD_VER <= 14
-    typedef iostate      io_state;
-    typedef openmode     open_mode;
-    typedef seekdir      seek_dir;
-
-    typedef _VSTD::streamoff streamoff;
-    typedef _VSTD::streampos streampos;
-#endif
-
-    class _LIBCPP_TYPE_VIS Init;
-
-    // 27.5.2.2 fmtflags state:
-    _LIBCPP_INLINE_VISIBILITY fmtflags flags() const;
-    _LIBCPP_INLINE_VISIBILITY fmtflags flags(fmtflags __fmtfl);
-    _LIBCPP_INLINE_VISIBILITY fmtflags setf(fmtflags __fmtfl);
-    _LIBCPP_INLINE_VISIBILITY fmtflags setf(fmtflags __fmtfl, fmtflags __mask);
-    _LIBCPP_INLINE_VISIBILITY void unsetf(fmtflags __mask);
-
-    _LIBCPP_INLINE_VISIBILITY streamsize precision() const;
-    _LIBCPP_INLINE_VISIBILITY streamsize precision(streamsize __prec);
-    _LIBCPP_INLINE_VISIBILITY streamsize width() const;
-    _LIBCPP_INLINE_VISIBILITY streamsize width(streamsize __wide);
-
-    // 27.5.2.3 locales:
-    locale imbue(const locale& __loc);
-    locale getloc() const;
-
-    // 27.5.2.5 storage:
-    static int xalloc();
-    long& iword(int __index);
-    void*& pword(int __index);
-
-    // destructor
-    virtual ~ios_base();
-
-    // 27.5.2.6 callbacks;
-    enum event { erase_event, imbue_event, copyfmt_event };
-    typedef void (*event_callback)(event, ios_base&, int __index);
-    void register_callback(event_callback __fn, int __index);
-
-private:
-    ios_base(const ios_base&); // = delete;
-    ios_base& operator=(const ios_base&); // = delete;
-
-public:
-    static bool sync_with_stdio(bool __sync = true);
-
-    _LIBCPP_INLINE_VISIBILITY iostate rdstate() const;
-    void clear(iostate __state = goodbit);
-    _LIBCPP_INLINE_VISIBILITY void setstate(iostate __state);
-
-    _LIBCPP_INLINE_VISIBILITY bool good() const;
-    _LIBCPP_INLINE_VISIBILITY bool eof() const;
-    _LIBCPP_INLINE_VISIBILITY bool fail() const;
-    _LIBCPP_INLINE_VISIBILITY bool bad() const;
-
-    _LIBCPP_INLINE_VISIBILITY iostate exceptions() const;
-    _LIBCPP_INLINE_VISIBILITY void exceptions(iostate __iostate);
-
-    void __set_badbit_and_consider_rethrow();
-    void __set_failbit_and_consider_rethrow();
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ios_base() {// purposefully does no initialization
-               }
-
-    void init(void* __sb);
-    _LIBCPP_INLINE_VISIBILITY void* rdbuf() const {return __rdbuf_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void rdbuf(void* __sb)
-    {
-        __rdbuf_ = __sb;
-        clear();
-    }
-
-    void __call_callbacks(event);
-    void copyfmt(const ios_base&);
-    void move(ios_base&);
-    void swap(ios_base&) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void set_rdbuf(void* __sb)
-    {
-        __rdbuf_ = __sb;
-    }
-
-private:
-    // All data members must be scalars
-    fmtflags        __fmtflags_;
-    streamsize      __precision_;
-    streamsize      __width_;
-    iostate         __rdstate_;
-    iostate         __exceptions_;
-    void*           __rdbuf_;
-    void*           __loc_;
-    event_callback* __fn_;
-    int*            __index_;
-    size_t          __event_size_;
-    size_t          __event_cap_;
-// TODO(EricWF): Enable this for both Clang and GCC. Currently it is only
-// enabled with clang.
-#if defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_NO_THREADS)
-    static atomic<int> __xindex_;
-#else
-    static int      __xindex_;
-#endif
-    long*           __iarray_;
-    size_t          __iarray_size_;
-    size_t          __iarray_cap_;
-    void**          __parray_;
-    size_t          __parray_size_;
-    size_t          __parray_cap_;
-};
-
-//enum class io_errc
-_LIBCPP_DECLARE_STRONG_ENUM(io_errc)
-{
-    stream = 1
-};
-_LIBCPP_DECLARE_STRONG_ENUM_EPILOG(io_errc)
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS is_error_code_enum<io_errc> : public true_type { };
-
-#ifdef _LIBCPP_HAS_NO_STRONG_ENUMS
-template <>
-struct _LIBCPP_TEMPLATE_VIS is_error_code_enum<io_errc::__lx> : public true_type { };
-#endif
-
-_LIBCPP_FUNC_VIS
-const error_category& iostream_category() _NOEXCEPT;
-
-inline _LIBCPP_INLINE_VISIBILITY
-error_code
-make_error_code(io_errc __e) _NOEXCEPT
-{
-    return error_code(static_cast<int>(__e), iostream_category());
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-error_condition
-make_error_condition(io_errc __e) _NOEXCEPT
-{
-    return error_condition(static_cast<int>(__e), iostream_category());
-}
-
-class _LIBCPP_EXCEPTION_ABI ios_base::failure
-    : public system_error
-{
-public:
-    explicit failure(const string& __msg, const error_code& __ec = io_errc::stream);
-    explicit failure(const char* __msg, const error_code& __ec = io_errc::stream);
-    virtual ~failure() throw();
-};
-
-class _LIBCPP_TYPE_VIS ios_base::Init
-{
-public:
-    Init();
-    ~Init();
-};
-
-// fmtflags
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base::fmtflags
-ios_base::flags() const
-{
-    return __fmtflags_;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base::fmtflags
-ios_base::flags(fmtflags __fmtfl)
-{
-    fmtflags __r = __fmtflags_;
-    __fmtflags_ = __fmtfl;
-    return __r;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base::fmtflags
-ios_base::setf(fmtflags __fmtfl)
-{
-    fmtflags __r = __fmtflags_;
-    __fmtflags_ |= __fmtfl;
-    return __r;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-ios_base::unsetf(fmtflags __mask)
-{
-    __fmtflags_ &= ~__mask;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base::fmtflags
-ios_base::setf(fmtflags __fmtfl, fmtflags __mask)
-{
-    fmtflags __r = __fmtflags_;
-    unsetf(__mask);
-    __fmtflags_ |= __fmtfl & __mask;
-    return __r;
-}
-
-// precision
-
-inline _LIBCPP_INLINE_VISIBILITY
-streamsize
-ios_base::precision() const
-{
-    return __precision_;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-streamsize
-ios_base::precision(streamsize __prec)
-{
-    streamsize __r = __precision_;
-    __precision_ = __prec;
-    return __r;
-}
-
-// width
-
-inline _LIBCPP_INLINE_VISIBILITY
-streamsize
-ios_base::width() const
-{
-    return __width_;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-streamsize
-ios_base::width(streamsize __wide)
-{
-    streamsize __r = __width_;
-    __width_ = __wide;
-    return __r;
-}
-
-// iostate
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base::iostate
-ios_base::rdstate() const
-{
-    return __rdstate_;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-ios_base::setstate(iostate __state)
-{
-    clear(__rdstate_ | __state);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-ios_base::good() const
-{
-    return __rdstate_ == 0;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-ios_base::eof() const
-{
-    return (__rdstate_ & eofbit) != 0;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-ios_base::fail() const
-{
-    return (__rdstate_ & (failbit | badbit)) != 0;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-ios_base::bad() const
-{
-    return (__rdstate_ & badbit) != 0;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base::iostate
-ios_base::exceptions() const
-{
-    return __exceptions_;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void
-ios_base::exceptions(iostate __iostate)
-{
-    __exceptions_ = __iostate;
-    clear(__rdstate_);
-}
-
-#if defined(_LIBCPP_CXX03_LANG)
-struct _LIBCPP_TYPE_VIS __cxx03_bool {
-  typedef void (__cxx03_bool::*__bool_type)();
-  void __true_value() {}
-};
-#endif
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_ios
-    : public ios_base
-{
-public:
-    // types:
-    typedef _CharT char_type;
-    typedef _Traits traits_type;
-
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
-                  "traits_type::char_type must be the same type as CharT");
-
-  // __true_value will generate undefined references when linking unless
-  // we give it internal linkage.
-
-#if defined(_LIBCPP_CXX03_LANG)
-    _LIBCPP_INLINE_VISIBILITY
-    operator __cxx03_bool::__bool_type() const {
-        return !fail() ? &__cxx03_bool::__true_value : nullptr;
-    }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_EXPLICIT operator bool() const {return !fail();}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY bool operator!() const    {return  fail();}
-    _LIBCPP_INLINE_VISIBILITY iostate rdstate() const   {return ios_base::rdstate();}
-    _LIBCPP_INLINE_VISIBILITY void clear(iostate __state = goodbit) {ios_base::clear(__state);}
-    _LIBCPP_INLINE_VISIBILITY void setstate(iostate __state) {ios_base::setstate(__state);}
-    _LIBCPP_INLINE_VISIBILITY bool good() const {return ios_base::good();}
-    _LIBCPP_INLINE_VISIBILITY bool eof() const  {return ios_base::eof();}
-    _LIBCPP_INLINE_VISIBILITY bool fail() const {return ios_base::fail();}
-    _LIBCPP_INLINE_VISIBILITY bool bad() const  {return ios_base::bad();}
-
-    _LIBCPP_INLINE_VISIBILITY iostate exceptions() const {return ios_base::exceptions();}
-    _LIBCPP_INLINE_VISIBILITY void exceptions(iostate __iostate) {ios_base::exceptions(__iostate);}
-
-    // 27.5.4.1 Constructor/destructor:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ios(basic_streambuf<char_type,traits_type>* __sb);
-    virtual ~basic_ios();
-
-    // 27.5.4.2 Members:
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_ostream<char_type, traits_type>* tie() const;
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_ostream<char_type, traits_type>* tie(basic_ostream<char_type, traits_type>* __tiestr);
-
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_streambuf<char_type, traits_type>* rdbuf() const;
-    _LIBCPP_INLINE_VISIBILITY 
-    basic_streambuf<char_type, traits_type>* rdbuf(basic_streambuf<char_type, traits_type>* __sb);
-
-    basic_ios& copyfmt(const basic_ios& __rhs);
-
-    _LIBCPP_INLINE_VISIBILITY 
-    char_type fill() const;
-    _LIBCPP_INLINE_VISIBILITY 
-    char_type fill(char_type __ch);
-
-    _LIBCPP_INLINE_VISIBILITY 
-    locale imbue(const locale& __loc);
-
-    _LIBCPP_INLINE_VISIBILITY 
-    char narrow(char_type __c, char __dfault) const;
-    _LIBCPP_INLINE_VISIBILITY 
-    char_type widen(char __c) const;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ios() {// purposefully does no initialization
-                }
-    _LIBCPP_INLINE_VISIBILITY 
-    void init(basic_streambuf<char_type, traits_type>* __sb);
-
-    _LIBCPP_INLINE_VISIBILITY 
-    void move(basic_ios& __rhs);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void move(basic_ios&& __rhs) {move(__rhs);}
-#endif
-    _LIBCPP_INLINE_VISIBILITY 
-    void swap(basic_ios& __rhs) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY 
-    void set_rdbuf(basic_streambuf<char_type, traits_type>* __sb);
-private:
-    basic_ostream<char_type, traits_type>* __tie_;
-    mutable int_type __fill_;
-};
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ios<_CharT, _Traits>::basic_ios(basic_streambuf<char_type,traits_type>* __sb)
-{
-    init(__sb);
-}
-
-template <class _CharT, class _Traits>
-basic_ios<_CharT, _Traits>::~basic_ios()
-{
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-basic_ios<_CharT, _Traits>::init(basic_streambuf<char_type, traits_type>* __sb)
-{
-    ios_base::init(__sb);
-    __tie_ = 0;
-    __fill_ = traits_type::eof();
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>*
-basic_ios<_CharT, _Traits>::tie() const
-{
-    return __tie_;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>*
-basic_ios<_CharT, _Traits>::tie(basic_ostream<char_type, traits_type>* __tiestr)
-{
-    basic_ostream<char_type, traits_type>* __r = __tie_;
-    __tie_ = __tiestr;
-    return __r;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_streambuf<_CharT, _Traits>*
-basic_ios<_CharT, _Traits>::rdbuf() const
-{
-    return static_cast<basic_streambuf<char_type, traits_type>*>(ios_base::rdbuf());
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_streambuf<_CharT, _Traits>*
-basic_ios<_CharT, _Traits>::rdbuf(basic_streambuf<char_type, traits_type>* __sb)
-{
-    basic_streambuf<char_type, traits_type>* __r = rdbuf();
-    ios_base::rdbuf(__sb);
-    return __r;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-locale
-basic_ios<_CharT, _Traits>::imbue(const locale& __loc)
-{
-    locale __r = getloc();
-    ios_base::imbue(__loc);
-    if (rdbuf())
-        rdbuf()->pubimbue(__loc);
-    return __r;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-char
-basic_ios<_CharT, _Traits>::narrow(char_type __c, char __dfault) const
-{
-    return use_facet<ctype<char_type> >(getloc()).narrow(__c, __dfault);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-_CharT
-basic_ios<_CharT, _Traits>::widen(char __c) const
-{
-    return use_facet<ctype<char_type> >(getloc()).widen(__c);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-_CharT
-basic_ios<_CharT, _Traits>::fill() const
-{
-    if (traits_type::eq_int_type(traits_type::eof(), __fill_))
-        __fill_ = widen(' ');
-    return __fill_;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-_CharT
-basic_ios<_CharT, _Traits>::fill(char_type __ch)
-{
-    char_type __r = __fill_;
-    __fill_ = __ch;
-    return __r;
-}
-
-template <class _CharT, class _Traits>
-basic_ios<_CharT, _Traits>&
-basic_ios<_CharT, _Traits>::copyfmt(const basic_ios& __rhs)
-{
-    if (this != &__rhs)
-    {
-        __call_callbacks(erase_event);
-        ios_base::copyfmt(__rhs);
-        __tie_ = __rhs.__tie_;
-        __fill_ = __rhs.__fill_;
-        __call_callbacks(copyfmt_event);
-        exceptions(__rhs.exceptions());
-    }
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-basic_ios<_CharT, _Traits>::move(basic_ios& __rhs)
-{
-    ios_base::move(__rhs);
-    __tie_ = __rhs.__tie_;
-    __rhs.__tie_ = 0;
-    __fill_ = __rhs.__fill_;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-basic_ios<_CharT, _Traits>::swap(basic_ios& __rhs) _NOEXCEPT
-{
-    ios_base::swap(__rhs);
-    _VSTD::swap(__tie_, __rhs.__tie_);
-    _VSTD::swap(__fill_, __rhs.__fill_);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-basic_ios<_CharT, _Traits>::set_rdbuf(basic_streambuf<char_type, traits_type>* __sb)
-{
-    ios_base::set_rdbuf(__sb);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-boolalpha(ios_base& __str)
-{
-    __str.setf(ios_base::boolalpha);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-noboolalpha(ios_base& __str)
-{
-    __str.unsetf(ios_base::boolalpha);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-showbase(ios_base& __str)
-{
-    __str.setf(ios_base::showbase);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-noshowbase(ios_base& __str)
-{
-    __str.unsetf(ios_base::showbase);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-showpoint(ios_base& __str)
-{
-    __str.setf(ios_base::showpoint);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-noshowpoint(ios_base& __str)
-{
-    __str.unsetf(ios_base::showpoint);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-showpos(ios_base& __str)
-{
-    __str.setf(ios_base::showpos);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-noshowpos(ios_base& __str)
-{
-    __str.unsetf(ios_base::showpos);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-skipws(ios_base& __str)
-{
-    __str.setf(ios_base::skipws);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-noskipws(ios_base& __str)
-{
-    __str.unsetf(ios_base::skipws);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-uppercase(ios_base& __str)
-{
-    __str.setf(ios_base::uppercase);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-nouppercase(ios_base& __str)
-{
-    __str.unsetf(ios_base::uppercase);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-unitbuf(ios_base& __str)
-{
-    __str.setf(ios_base::unitbuf);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-nounitbuf(ios_base& __str)
-{
-    __str.unsetf(ios_base::unitbuf);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-internal(ios_base& __str)
-{
-    __str.setf(ios_base::internal, ios_base::adjustfield);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-left(ios_base& __str)
-{
-    __str.setf(ios_base::left, ios_base::adjustfield);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-right(ios_base& __str)
-{
-    __str.setf(ios_base::right, ios_base::adjustfield);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-dec(ios_base& __str)
-{
-    __str.setf(ios_base::dec, ios_base::basefield);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-hex(ios_base& __str)
-{
-    __str.setf(ios_base::hex, ios_base::basefield);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-oct(ios_base& __str)
-{
-    __str.setf(ios_base::oct, ios_base::basefield);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-fixed(ios_base& __str)
-{
-    __str.setf(ios_base::fixed, ios_base::floatfield);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-scientific(ios_base& __str)
-{
-    __str.setf(ios_base::scientific, ios_base::floatfield);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-hexfloat(ios_base& __str)
-{
-    __str.setf(ios_base::fixed | ios_base::scientific, ios_base::floatfield);
-    return __str;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-ios_base&
-defaultfloat(ios_base& __str)
-{
-    __str.unsetf(ios_base::floatfield);
-    return __str;
-}
-
-template <class _CharT, class _Traits>
-class __save_flags
-{
-    typedef basic_ios<_CharT, _Traits> __stream_type;
-    typedef typename __stream_type::fmtflags fmtflags;
-
-    __stream_type& __stream_;
-    fmtflags       __fmtflags_;
-    _CharT         __fill_;
-
-    __save_flags(const __save_flags&);
-    __save_flags& operator=(const __save_flags&);
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __save_flags(__stream_type& __stream)
-        : __stream_(__stream),
-          __fmtflags_(__stream.flags()),
-          __fill_(__stream.fill())
-        {}
-    _LIBCPP_INLINE_VISIBILITY
-    ~__save_flags()
-    {
-        __stream_.flags(__fmtflags_);
-        __stream_.fill(__fill_);
-    }
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_IOS
diff --git a/lib/libcxx/include/iosfwd b/lib/libcxx/include/iosfwd
deleted file mode 100644
index 31f1902e5f5..00000000000
--- a/lib/libcxx/include/iosfwd
+++ /dev/null
@@ -1,221 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- iosfwd -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_IOSFWD
-#define _LIBCPP_IOSFWD
-
-/*
-    iosfwd synopsis
-
-namespace std
-{
-
-template<class charT> struct char_traits;
-template<>            struct char_traits<char>;
-template<>            struct char_traits<char8_t>;  // C++20
-template<>            struct char_traits<char16_t>;
-template<>            struct char_traits<char32_t>;
-template<>            struct char_traits<wchar_t>;
-
-template<class T>     class allocator;
-
-class ios_base;
-template <class charT, class traits = char_traits<charT> > class basic_ios;
-
-template <class charT, class traits = char_traits<charT> > class basic_streambuf;
-template <class charT, class traits = char_traits<charT> > class basic_istream;
-template <class charT, class traits = char_traits<charT> > class basic_ostream;
-template <class charT, class traits = char_traits<charT> > class basic_iostream;
-
-template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
-    class basic_stringbuf;
-template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
-    class basic_istringstream;
-template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
-    class basic_ostringstream;
-template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
-    class basic_stringstream;
-
-template <class charT, class traits = char_traits<charT> > class basic_filebuf;
-template <class charT, class traits = char_traits<charT> > class basic_ifstream;
-template <class charT, class traits = char_traits<charT> > class basic_ofstream;
-template <class charT, class traits = char_traits<charT> > class basic_fstream;
-
-template <class charT, class traits = char_traits<charT> > class istreambuf_iterator;
-template <class charT, class traits = char_traits<charT> > class ostreambuf_iterator;
-
-typedef basic_ios<char>              ios;
-typedef basic_ios<wchar_t>           wios;
-
-typedef basic_streambuf<char>        streambuf;
-typedef basic_istream<char>          istream;
-typedef basic_ostream<char>          ostream;
-typedef basic_iostream<char>         iostream;
-
-typedef basic_stringbuf<char>        stringbuf;
-typedef basic_istringstream<char>    istringstream;
-typedef basic_ostringstream<char>    ostringstream;
-typedef basic_stringstream<char>     stringstream;
-
-typedef basic_filebuf<char>          filebuf;
-typedef basic_ifstream<char>         ifstream;
-typedef basic_ofstream<char>         ofstream;
-typedef basic_fstream<char>          fstream;
-
-typedef basic_streambuf<wchar_t>     wstreambuf;
-typedef basic_istream<wchar_t>       wistream;
-typedef basic_ostream<wchar_t>       wostream;
-typedef basic_iostream<wchar_t>      wiostream;
-
-typedef basic_stringbuf<wchar_t>     wstringbuf;
-typedef basic_istringstream<wchar_t> wistringstream;
-typedef basic_ostringstream<wchar_t> wostringstream;
-typedef basic_stringstream<wchar_t>  wstringstream;
-
-typedef basic_filebuf<wchar_t>       wfilebuf;
-typedef basic_ifstream<wchar_t>      wifstream;
-typedef basic_ofstream<wchar_t>      wofstream;
-typedef basic_fstream<wchar_t>       wfstream;
-
-template <class state> class fpos;
-typedef fpos<char_traits<char>::state_type>    streampos;
-typedef fpos<char_traits<wchar_t>::state_type> wstreampos;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <wchar.h>  // for mbstate_t
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-class _LIBCPP_TYPE_VIS ios_base;
-
-template<class _CharT>  struct _LIBCPP_TEMPLATE_VIS char_traits;
-template<> struct char_traits<char>;
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-template<> struct char_traits<char8_t>;
-#endif
-template<> struct char_traits<char16_t>;
-template<> struct char_traits<char32_t>;
-template<> struct char_traits<wchar_t>;
-
-template<class _Tp>     class _LIBCPP_TEMPLATE_VIS allocator;
-
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_ios;
-
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_streambuf;
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_istream;
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_ostream;
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_iostream;
-
-template <class _CharT, class _Traits = char_traits<_CharT>,
-          class _Allocator = allocator<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_stringbuf;
-template <class _CharT, class _Traits = char_traits<_CharT>,
-          class _Allocator = allocator<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_istringstream;
-template <class _CharT, class _Traits = char_traits<_CharT>,
-          class _Allocator = allocator<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_ostringstream;
-template <class _CharT, class _Traits = char_traits<_CharT>,
-          class _Allocator = allocator<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_stringstream;
-
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_filebuf;
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_ifstream;
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_ofstream;
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_fstream;
-
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS istreambuf_iterator;
-template <class _CharT, class _Traits = char_traits<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS ostreambuf_iterator;
-
-typedef basic_ios<char>              ios;
-typedef basic_ios<wchar_t>           wios;
-
-typedef basic_streambuf<char>        streambuf;
-typedef basic_istream<char>          istream;
-typedef basic_ostream<char>          ostream;
-typedef basic_iostream<char>         iostream;
-
-typedef basic_stringbuf<char>        stringbuf;
-typedef basic_istringstream<char>    istringstream;
-typedef basic_ostringstream<char>    ostringstream;
-typedef basic_stringstream<char>     stringstream;
-
-typedef basic_filebuf<char>          filebuf;
-typedef basic_ifstream<char>         ifstream;
-typedef basic_ofstream<char>         ofstream;
-typedef basic_fstream<char>          fstream;
-
-typedef basic_streambuf<wchar_t>     wstreambuf;
-typedef basic_istream<wchar_t>       wistream;
-typedef basic_ostream<wchar_t>       wostream;
-typedef basic_iostream<wchar_t>      wiostream;
-
-typedef basic_stringbuf<wchar_t>     wstringbuf;
-typedef basic_istringstream<wchar_t> wistringstream;
-typedef basic_ostringstream<wchar_t> wostringstream;
-typedef basic_stringstream<wchar_t>  wstringstream;
-
-typedef basic_filebuf<wchar_t>       wfilebuf;
-typedef basic_ifstream<wchar_t>      wifstream;
-typedef basic_ofstream<wchar_t>      wofstream;
-typedef basic_fstream<wchar_t>       wfstream;
-
-template <class _State>             class _LIBCPP_TEMPLATE_VIS fpos;
-typedef fpos<mbstate_t>    streampos;
-typedef fpos<mbstate_t>    wstreampos;
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-typedef fpos<mbstate_t>    u8streampos;
-#endif
-#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
-typedef fpos<mbstate_t>    u16streampos;
-typedef fpos<mbstate_t>    u32streampos;
-#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
-
-#if defined(_NEWLIB_VERSION)
-// On newlib, off_t is 'long int'
-typedef long int streamoff;         // for char_traits in <string>
-#else
-typedef long long streamoff;        // for char_traits in <string>
-#endif
-
-template <class _CharT,             // for <stdexcept>
-          class _Traits = char_traits<_CharT>,
-          class _Allocator = allocator<_CharT> >
-    class _LIBCPP_TEMPLATE_VIS basic_string;
-typedef basic_string<char, char_traits<char>, allocator<char> > string;
-typedef basic_string<wchar_t, char_traits<wchar_t>, allocator<wchar_t> > wstring;
-
-
-// Include other forward declarations here
-template <class _Tp, class _Alloc = allocator<_Tp> >
-class _LIBCPP_TEMPLATE_VIS vector;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_IOSFWD
diff --git a/lib/libcxx/include/iostream b/lib/libcxx/include/iostream
deleted file mode 100644
index 136a849777f..00000000000
--- a/lib/libcxx/include/iostream
+++ /dev/null
@@ -1,64 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- iostream ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_IOSTREAM
-#define _LIBCPP_IOSTREAM
-
-/*
-    iostream synopsis
-
-#include <ios>
-#include <streambuf>
-#include <istream>
-#include <ostream>
-
-namespace std {
-
-extern istream cin;
-extern ostream cout;
-extern ostream cerr;
-extern ostream clog;
-extern wistream wcin;
-extern wostream wcout;
-extern wostream wcerr;
-extern wostream wclog;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <ios>
-#include <streambuf>
-#include <istream>
-#include <ostream>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#ifndef _LIBCPP_HAS_NO_STDIN
-extern _LIBCPP_FUNC_VIS istream cin;
-extern _LIBCPP_FUNC_VIS wistream wcin;
-#endif
-#ifndef _LIBCPP_HAS_NO_STDOUT
-extern _LIBCPP_FUNC_VIS ostream cout;
-extern _LIBCPP_FUNC_VIS wostream wcout;
-#endif
-extern _LIBCPP_FUNC_VIS ostream cerr;
-extern _LIBCPP_FUNC_VIS wostream wcerr;
-extern _LIBCPP_FUNC_VIS ostream clog;
-extern _LIBCPP_FUNC_VIS wostream wclog;
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_IOSTREAM
diff --git a/lib/libcxx/include/istream b/lib/libcxx/include/istream
deleted file mode 100644
index 30ee4f4b871..00000000000
--- a/lib/libcxx/include/istream
+++ /dev/null
@@ -1,1518 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- istream ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_ISTREAM
-#define _LIBCPP_ISTREAM
-
-/*
-    istream synopsis
-
-template <class charT, class traits = char_traits<charT> >
-class basic_istream
-    : virtual public basic_ios<charT,traits>
-{
-public:
-    // types (inherited from basic_ios (27.5.4)):
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    // 27.7.1.1.1 Constructor/destructor:
-    explicit basic_istream(basic_streambuf<char_type, traits_type>* sb);
-    basic_istream(basic_istream&& rhs);
-    virtual ~basic_istream();
-
-    // 27.7.1.1.2 Assign/swap:
-    basic_istream& operator=(basic_istream&& rhs);
-    void swap(basic_istream& rhs);
-
-    // 27.7.1.1.3 Prefix/suffix:
-    class sentry;
-
-    // 27.7.1.2 Formatted input:
-    basic_istream& operator>>(basic_istream& (*pf)(basic_istream&));
-    basic_istream& operator>>(basic_ios<char_type, traits_type>&
-                              (*pf)(basic_ios<char_type, traits_type>&));
-    basic_istream& operator>>(ios_base& (*pf)(ios_base&));
-    basic_istream& operator>>(basic_streambuf<char_type, traits_type>* sb);
-    basic_istream& operator>>(bool& n);
-    basic_istream& operator>>(short& n);
-    basic_istream& operator>>(unsigned short& n);
-    basic_istream& operator>>(int& n);
-    basic_istream& operator>>(unsigned int& n);
-    basic_istream& operator>>(long& n);
-    basic_istream& operator>>(unsigned long& n);
-    basic_istream& operator>>(long long& n);
-    basic_istream& operator>>(unsigned long long& n);
-    basic_istream& operator>>(float& f);
-    basic_istream& operator>>(double& f);
-    basic_istream& operator>>(long double& f);
-    basic_istream& operator>>(void*& p);
-
-    // 27.7.1.3 Unformatted input:
-    streamsize gcount() const;
-    int_type get();
-    basic_istream& get(char_type& c);
-    basic_istream& get(char_type* s, streamsize n);
-    basic_istream& get(char_type* s, streamsize n, char_type delim);
-    basic_istream& get(basic_streambuf<char_type,traits_type>& sb);
-    basic_istream& get(basic_streambuf<char_type,traits_type>& sb, char_type delim);
-
-    basic_istream& getline(char_type* s, streamsize n);
-    basic_istream& getline(char_type* s, streamsize n, char_type delim);
-
-    basic_istream& ignore(streamsize n = 1, int_type delim = traits_type::eof());
-    int_type peek();
-    basic_istream& read (char_type* s, streamsize n);
-    streamsize readsome(char_type* s, streamsize n);
-
-    basic_istream& putback(char_type c);
-    basic_istream& unget();
-    int sync();
-
-    pos_type tellg();
-    basic_istream& seekg(pos_type);
-    basic_istream& seekg(off_type, ios_base::seekdir);
-protected:
-    basic_istream(const basic_istream& rhs) = delete;
-    basic_istream(basic_istream&& rhs);
-    // 27.7.2.1.2 Assign/swap:
-    basic_istream& operator=(const basic_istream& rhs) = delete;
-    basic_istream& operator=(basic_istream&& rhs);
-    void swap(basic_istream& rhs);
-};
-
-// 27.7.1.2.3 character extraction templates:
-template<class charT, class traits>
-  basic_istream<charT,traits>& operator>>(basic_istream<charT,traits>&, charT&);
-
-template<class traits>
-  basic_istream<char,traits>& operator>>(basic_istream<char,traits>&, unsigned char&);
-
-template<class traits>
-  basic_istream<char,traits>& operator>>(basic_istream<char,traits>&, signed char&);
-
-template<class charT, class traits>
-  basic_istream<charT,traits>& operator>>(basic_istream<charT,traits>&, charT*);
-
-template<class traits>
-  basic_istream<char,traits>& operator>>(basic_istream<char,traits>&, unsigned char*);
-
-template<class traits>
-  basic_istream<char,traits>& operator>>(basic_istream<char,traits>&, signed char*);
-
-template <class charT, class traits>
-  void
-  swap(basic_istream<charT, traits>& x, basic_istream<charT, traits>& y);
-
-typedef basic_istream<char> istream;
-typedef basic_istream<wchar_t> wistream;
-
-template <class charT, class traits = char_traits<charT> >
-class basic_iostream :
-    public basic_istream<charT,traits>,
-    public basic_ostream<charT,traits>
-{
-public:
-    // types:
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    // constructor/destructor
-    explicit basic_iostream(basic_streambuf<char_type, traits_type>* sb);
-    basic_iostream(basic_iostream&& rhs);
-    virtual ~basic_iostream();
-
-    // assign/swap
-    basic_iostream& operator=(basic_iostream&& rhs);
-    void swap(basic_iostream& rhs);
-};
-
-template <class charT, class traits>
-  void
-  swap(basic_iostream<charT, traits>& x, basic_iostream<charT, traits>& y);
-
-typedef basic_iostream<char> iostream;
-typedef basic_iostream<wchar_t> wiostream;
-
-template <class charT, class traits>
-  basic_istream<charT,traits>&
-  ws(basic_istream<charT,traits>& is);
-
-template <class charT, class traits, class T>
-  basic_istream<charT, traits>&
-  operator>>(basic_istream<charT, traits>&& is, T& x);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <version>
-#include <ostream>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_istream
-    : virtual public basic_ios<_CharT, _Traits>
-{
-    streamsize __gc_;
-public:
-    // types (inherited from basic_ios (27.5.4)):
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    // 27.7.1.1.1 Constructor/destructor:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    explicit basic_istream(basic_streambuf<char_type, traits_type>* __sb) : __gc_(0)
-    { this->init(__sb); }
-    virtual ~basic_istream();
-protected:
-#ifndef _LIBCPP_CXX03_LANG
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_istream(basic_istream&& __rhs);
-
-    // 27.7.1.1.2 Assign/swap:
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_istream& operator=(basic_istream&& __rhs);
-#endif
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    void swap(basic_istream& __rhs) {
-      _VSTD::swap(__gc_, __rhs.__gc_);
-      basic_ios<char_type, traits_type>::swap(__rhs);
-    }
-
-#ifndef _LIBCPP_CXX03_LANG
-    basic_istream           (const basic_istream& __rhs) = delete;
-    basic_istream& operator=(const basic_istream& __rhs) = delete;
-#endif
-public:
-
-    // 27.7.1.1.3 Prefix/suffix:
-    class _LIBCPP_TEMPLATE_VIS sentry;
-
-    // 27.7.1.2 Formatted input:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_istream& operator>>(basic_istream& (*__pf)(basic_istream&))
-    { return __pf(*this); }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_istream& operator>>(basic_ios<char_type, traits_type>&
-                              (*__pf)(basic_ios<char_type, traits_type>&))
-    { __pf(*this); return *this; }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_istream& operator>>(ios_base& (*__pf)(ios_base&))
-    { __pf(*this); return *this; }
-
-    basic_istream& operator>>(basic_streambuf<char_type, traits_type>* __sb);
-    basic_istream& operator>>(bool& __n);
-    basic_istream& operator>>(short& __n);
-    basic_istream& operator>>(unsigned short& __n);
-    basic_istream& operator>>(int& __n);
-    basic_istream& operator>>(unsigned int& __n);
-    basic_istream& operator>>(long& __n);
-    basic_istream& operator>>(unsigned long& __n);
-    basic_istream& operator>>(long long& __n);
-    basic_istream& operator>>(unsigned long long& __n);
-    basic_istream& operator>>(float& __f);
-    basic_istream& operator>>(double& __f);
-    basic_istream& operator>>(long double& __f);
-    basic_istream& operator>>(void*& __p);
-
-    // 27.7.1.3 Unformatted input:
-    _LIBCPP_INLINE_VISIBILITY
-    streamsize gcount() const {return __gc_;}
-    int_type get();
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_istream& get(char_type& __c) {
-      int_type __ch = get();
-      if (__ch != traits_type::eof())
-        __c = traits_type::to_char_type(__ch);
-      return *this;
-    }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_istream& get(char_type* __s, streamsize __n)
-    { return get(__s, __n, this->widen('\n')); }
-
-    basic_istream& get(char_type* __s, streamsize __n, char_type __dlm);
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_istream& get(basic_streambuf<char_type, traits_type>& __sb)
-    { return get(__sb, this->widen('\n')); }
-
-    basic_istream& get(basic_streambuf<char_type, traits_type>& __sb, char_type __dlm);
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_istream& getline(char_type* __s, streamsize __n)
-    { return getline(__s, __n, this->widen('\n')); }
-
-    basic_istream& getline(char_type* __s, streamsize __n, char_type __dlm);
-
-    basic_istream& ignore(streamsize __n = 1, int_type __dlm = traits_type::eof());
-    int_type peek();
-    basic_istream& read (char_type* __s, streamsize __n);
-    streamsize readsome(char_type* __s, streamsize __n);
-
-    basic_istream& putback(char_type __c);
-    basic_istream& unget();
-    int sync();
-
-    pos_type tellg();
-    basic_istream& seekg(pos_type __pos);
-    basic_istream& seekg(off_type __off, ios_base::seekdir __dir);
-};
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_istream<_CharT, _Traits>::sentry
-{
-    bool __ok_;
-
-    sentry(const sentry&); // = delete;
-    sentry& operator=(const sentry&); // = delete;
-
-public:
-    explicit sentry(basic_istream<_CharT, _Traits>& __is, bool __noskipws = false);
-//    ~sentry() = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-        _LIBCPP_EXPLICIT
-        operator bool() const {return __ok_;}
-};
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>::sentry::sentry(basic_istream<_CharT, _Traits>& __is,
-                                               bool __noskipws)
-    : __ok_(false)
-{
-    if (__is.good())
-    {
-        if (__is.tie())
-            __is.tie()->flush();
-        if (!__noskipws && (__is.flags() & ios_base::skipws))
-        {
-            typedef istreambuf_iterator<_CharT, _Traits> _Ip;
-            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
-            _Ip __i(__is);
-            _Ip __eof;
-            for (; __i != __eof; ++__i)
-                if (!__ct.is(__ct.space, *__i))
-                    break;
-            if (__i == __eof)
-                __is.setstate(ios_base::failbit | ios_base::eofbit);
-        }
-        __ok_ = __is.good();
-    }
-    else
-        __is.setstate(ios_base::failbit);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>::basic_istream(basic_istream&& __rhs)
-    : __gc_(__rhs.__gc_)
-{
-    __rhs.__gc_ = 0;
-    this->move(__rhs);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator=(basic_istream&& __rhs)
-{
-    swap(__rhs);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>::~basic_istream()
-{
-}
-
-template <class _Tp, class _CharT, class _Traits>
-_LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-__input_arithmetic(basic_istream<_CharT, _Traits>& __is, _Tp& __n) {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __s(__is);
-        if (__s)
-        {
-            typedef istreambuf_iterator<_CharT, _Traits> _Ip;
-            typedef num_get<_CharT, _Ip> _Fp;
-            ios_base::iostate __err = ios_base::goodbit;
-            use_facet<_Fp>(__is.getloc()).get(_Ip(__is), _Ip(), __is, __err, __n);
-            __is.setstate(__err);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(unsigned short& __n)
-{
-    return _VSTD::__input_arithmetic<unsigned short>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(unsigned int& __n)
-{
-    return _VSTD::__input_arithmetic<unsigned int>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(long& __n)
-{
-    return _VSTD::__input_arithmetic<long>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(unsigned long& __n)
-{
-    return _VSTD::__input_arithmetic<unsigned long>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(long long& __n)
-{
-    return _VSTD::__input_arithmetic<long long>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(unsigned long long& __n)
-{
-    return _VSTD::__input_arithmetic<unsigned long long>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(float& __n)
-{
-    return _VSTD::__input_arithmetic<float>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(double& __n)
-{
-    return _VSTD::__input_arithmetic<double>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(long double& __n)
-{
-    return _VSTD::__input_arithmetic<long double>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(bool& __n)
-{
-    return _VSTD::__input_arithmetic<bool>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(void*& __n)
-{
-    return _VSTD::__input_arithmetic<void*>(*this, __n);
-}
-
-template <class _Tp, class _CharT, class _Traits>
-_LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-__input_arithmetic_with_numeric_limits(basic_istream<_CharT, _Traits>& __is, _Tp& __n) {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __s(__is);
-        if (__s)
-        {
-            typedef istreambuf_iterator<_CharT, _Traits> _Ip;
-            typedef num_get<_CharT, _Ip> _Fp;
-            ios_base::iostate __err = ios_base::goodbit;
-            long __temp;
-            use_facet<_Fp>(__is.getloc()).get(_Ip(__is), _Ip(), __is, __err, __temp);
-            if (__temp < numeric_limits<_Tp>::min())
-            {
-                __err |= ios_base::failbit;
-                __n = numeric_limits<_Tp>::min();
-            }
-            else if (__temp > numeric_limits<_Tp>::max())
-            {
-                __err |= ios_base::failbit;
-                __n = numeric_limits<_Tp>::max();
-            }
-            else
-                __n = static_cast<_Tp>(__temp);
-            __is.setstate(__err);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(short& __n)
-{
-    return _VSTD::__input_arithmetic_with_numeric_limits<short>(*this, __n);
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(int& __n)
-{
-    return _VSTD::__input_arithmetic_with_numeric_limits<int>(*this, __n);
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-__input_c_string(basic_istream<_CharT, _Traits>& __is, _CharT* __p, size_t __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __sen(__is);
-        if (__sen)
-        {
-            auto __s = __p;
-            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
-            ios_base::iostate __err = ios_base::goodbit;
-            while (__s != __p + (__n-1))
-            {
-                typename _Traits::int_type __i = __is.rdbuf()->sgetc();
-                if (_Traits::eq_int_type(__i, _Traits::eof()))
-                {
-                   __err |= ios_base::eofbit;
-                   break;
-                }
-                _CharT __ch = _Traits::to_char_type(__i);
-                if (__ct.is(__ct.space, __ch))
-                    break;
-                *__s++ = __ch;
-                 __is.rdbuf()->sbumpc();
-            }
-            *__s = _CharT();
-            __is.width(0);
-            if (__s == __p)
-               __err |= ios_base::failbit;
-            __is.setstate(__err);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-#if _LIBCPP_STD_VER > 17
-
-template<class _CharT, class _Traits, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, _CharT (&__buf)[_Np])
-{
-    auto __n = _Np;
-    if (__is.width() > 0)
-        __n = _VSTD::min(size_t(__is.width()), _Np);
-    return _VSTD::__input_c_string(__is, __buf, __n);
-}
-
-template<class _Traits, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<char, _Traits>&
-operator>>(basic_istream<char, _Traits>& __is, unsigned char (&__buf)[_Np])
-{
-    return __is >> (char(&)[_Np])__buf;
-}
-
-template<class _Traits, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<char, _Traits>&
-operator>>(basic_istream<char, _Traits>& __is, signed char (&__buf)[_Np])
-{
-    return __is >> (char(&)[_Np])__buf;
-}
-
-#else
-
-template<class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, _CharT* __s)
-{
-    streamsize __n = __is.width();
-    if (__n <= 0)
-        __n = numeric_limits<streamsize>::max() / sizeof(_CharT) - 1;
-    return _VSTD::__input_c_string(__is, __s, size_t(__n));
-}
-
-template<class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<char, _Traits>&
-operator>>(basic_istream<char, _Traits>& __is, unsigned char* __s)
-{
-    return __is >> (char*)__s;
-}
-
-template<class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<char, _Traits>&
-operator>>(basic_istream<char, _Traits>& __is, signed char* __s)
-{
-    return __is >> (char*)__s;
-}
-
-#endif  // _LIBCPP_STD_VER > 17
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, _CharT& __c)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __sen(__is);
-        if (__sen)
-        {
-            typename _Traits::int_type __i = __is.rdbuf()->sbumpc();
-            if (_Traits::eq_int_type(__i, _Traits::eof()))
-                __is.setstate(ios_base::eofbit | ios_base::failbit);
-            else
-                __c = _Traits::to_char_type(__i);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-template<class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<char, _Traits>&
-operator>>(basic_istream<char, _Traits>& __is, unsigned char& __c)
-{
-    return __is >> (char&)__c;
-}
-
-template<class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<char, _Traits>&
-operator>>(basic_istream<char, _Traits>& __is, signed char& __c)
-{
-    return __is >> (char&)__c;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::operator>>(basic_streambuf<char_type, traits_type>* __sb)
-{
-    __gc_ = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this, true);
-        if (__s)
-        {
-            if (__sb)
-            {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-                try
-                {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-                    ios_base::iostate __err = ios_base::goodbit;
-                    while (true)
-                    {
-                        typename traits_type::int_type __i = this->rdbuf()->sgetc();
-                        if (traits_type::eq_int_type(__i, _Traits::eof()))
-                        {
-                           __err |= ios_base::eofbit;
-                           break;
-                        }
-                        if (traits_type::eq_int_type(
-                                __sb->sputc(traits_type::to_char_type(__i)),
-                                traits_type::eof()))
-                            break;
-                        ++__gc_;
-                        this->rdbuf()->sbumpc();
-                    }
-                    if (__gc_ == 0)
-                       __err |= ios_base::failbit;
-                    this->setstate(__err);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-                }
-                catch (...)
-                {
-                    if (__gc_ == 0)
-                        this->__set_failbit_and_consider_rethrow();
-                }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            }
-            else
-                this->setstate(ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-typename basic_istream<_CharT, _Traits>::int_type
-basic_istream<_CharT, _Traits>::get()
-{
-    __gc_ = 0;
-    int_type __r = traits_type::eof();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this, true);
-        if (__s)
-        {
-            __r = this->rdbuf()->sbumpc();
-            if (traits_type::eq_int_type(__r, traits_type::eof()))
-               this->setstate(ios_base::failbit | ios_base::eofbit);
-            else
-                __gc_ = 1;
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __r;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::get(char_type* __s, streamsize __n, char_type __dlm)
-{
-    __gc_ = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            if (__n > 0)
-            {
-                ios_base::iostate __err = ios_base::goodbit;
-                while (__gc_ < __n-1)
-                {
-                    int_type __i = this->rdbuf()->sgetc();
-                    if (traits_type::eq_int_type(__i, traits_type::eof()))
-                    {
-                       __err |= ios_base::eofbit;
-                       break;
-                    }
-                    char_type __ch = traits_type::to_char_type(__i);
-                    if (traits_type::eq(__ch, __dlm))
-                        break;
-                    *__s++ = __ch;
-                    ++__gc_;
-                     this->rdbuf()->sbumpc();
-                }
-                if (__gc_ == 0)
-                   __err |= ios_base::failbit;
-                this->setstate(__err);
-            }
-            else
-                this->setstate(ios_base::failbit);
-        }
-        if (__n > 0)
-            *__s = char_type();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        if (__n > 0)
-            *__s = char_type();
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::get(basic_streambuf<char_type, traits_type>& __sb,
-                                    char_type __dlm)
-{
-    __gc_ = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            ios_base::iostate __err = ios_base::goodbit;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-            try
-            {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-                while (true)
-                {
-                    typename traits_type::int_type __i = this->rdbuf()->sgetc();
-                    if (traits_type::eq_int_type(__i, traits_type::eof()))
-                    {
-                       __err |= ios_base::eofbit;
-                       break;
-                    }
-                    char_type __ch = traits_type::to_char_type(__i);
-                    if (traits_type::eq(__ch, __dlm))
-                        break;
-                    if (traits_type::eq_int_type(__sb.sputc(__ch), traits_type::eof()))
-                        break;
-                    ++__gc_;
-                    this->rdbuf()->sbumpc();
-                }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-            }
-            catch (...)
-            {
-            }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            if (__gc_ == 0)
-               __err |= ios_base::failbit;
-            this->setstate(__err);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::getline(char_type* __s, streamsize __n, char_type __dlm)
-{
-    __gc_ = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            ios_base::iostate __err = ios_base::goodbit;
-            while (true)
-            {
-                typename traits_type::int_type __i = this->rdbuf()->sgetc();
-                if (traits_type::eq_int_type(__i, traits_type::eof()))
-                {
-                   __err |= ios_base::eofbit;
-                   break;
-                }
-                char_type __ch = traits_type::to_char_type(__i);
-                if (traits_type::eq(__ch, __dlm))
-                {
-                    this->rdbuf()->sbumpc();
-                    ++__gc_;
-                    break;
-                }
-                if (__gc_ >= __n-1)
-                {
-                    __err |= ios_base::failbit;
-                    break;
-                }
-                *__s++ = __ch;
-                this->rdbuf()->sbumpc();
-                ++__gc_;
-            }
-            if (__gc_ == 0)
-               __err |= ios_base::failbit;
-            this->setstate(__err);
-        }
-        if (__n > 0)
-            *__s = char_type();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        if (__n > 0)
-            *__s = char_type();
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::ignore(streamsize __n, int_type __dlm)
-{
-    __gc_ = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            ios_base::iostate __err = ios_base::goodbit;
-            if (__n == numeric_limits<streamsize>::max())
-            {
-                while (true)
-                {
-                    typename traits_type::int_type __i = this->rdbuf()->sbumpc();
-                    if (traits_type::eq_int_type(__i, traits_type::eof()))
-                    {
-                       __err |= ios_base::eofbit;
-                       break;
-                    }
-                    ++__gc_;
-                    if (traits_type::eq_int_type(__i, __dlm))
-                        break;
-                }
-            }
-            else
-            {
-                while (__gc_ < __n)
-                {
-                    typename traits_type::int_type __i = this->rdbuf()->sbumpc();
-                    if (traits_type::eq_int_type(__i, traits_type::eof()))
-                    {
-                       __err |= ios_base::eofbit;
-                       break;
-                    }
-                    ++__gc_;
-                    if (traits_type::eq_int_type(__i, __dlm))
-                        break;
-                }
-            }
-            this->setstate(__err);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-typename basic_istream<_CharT, _Traits>::int_type
-basic_istream<_CharT, _Traits>::peek()
-{
-    __gc_ = 0;
-    int_type __r = traits_type::eof();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            __r = this->rdbuf()->sgetc();
-            if (traits_type::eq_int_type(__r, traits_type::eof()))
-                this->setstate(ios_base::eofbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __r;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::read(char_type* __s, streamsize __n)
-{
-    __gc_ = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            __gc_ = this->rdbuf()->sgetn(__s, __n);
-            if (__gc_ != __n)
-                this->setstate(ios_base::failbit | ios_base::eofbit);
-        }
-        else
-            this->setstate(ios_base::failbit);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-streamsize
-basic_istream<_CharT, _Traits>::readsome(char_type* __s, streamsize __n)
-{
-    __gc_ = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            streamsize __c = this->rdbuf()->in_avail();
-            switch (__c)
-            {
-            case -1:
-                this->setstate(ios_base::eofbit);
-                break;
-            case 0:
-                break;
-            default:
-                read(__s, _VSTD::min(__c, __n));
-                break;
-            }
-        }
-        else
-            this->setstate(ios_base::failbit);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __gc_;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::putback(char_type __c)
-{
-    __gc_ = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        this->clear(this->rdstate() & ~ios_base::eofbit);
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            if (this->rdbuf() == 0 || this->rdbuf()->sputbackc(__c) == traits_type::eof())
-                this->setstate(ios_base::badbit);
-        }
-        else
-            this->setstate(ios_base::failbit);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::unget()
-{
-    __gc_ = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        this->clear(this->rdstate() & ~ios_base::eofbit);
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            if (this->rdbuf() == 0 || this->rdbuf()->sungetc() == traits_type::eof())
-                this->setstate(ios_base::badbit);
-        }
-        else
-            this->setstate(ios_base::failbit);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-int
-basic_istream<_CharT, _Traits>::sync()
-{
-    int __r = 0;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            if (this->rdbuf() == 0)
-                return -1;
-            if (this->rdbuf()->pubsync() == -1)
-            {
-                this->setstate(ios_base::badbit);
-                return -1;
-            }
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __r;
-}
-
-template<class _CharT, class _Traits>
-typename basic_istream<_CharT, _Traits>::pos_type
-basic_istream<_CharT, _Traits>::tellg()
-{
-    pos_type __r(-1);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this, true);
-        if (__sen)
-            __r = this->rdbuf()->pubseekoff(0, ios_base::cur, ios_base::in);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __r;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::seekg(pos_type __pos)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        this->clear(this->rdstate() & ~ios_base::eofbit);
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            if (this->rdbuf()->pubseekpos(__pos, ios_base::in) == pos_type(-1))
-                this->setstate(ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-basic_istream<_CharT, _Traits>::seekg(off_type __off, ios_base::seekdir __dir)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        this->clear(this->rdstate() & ~ios_base::eofbit);
-        sentry __sen(*this, true);
-        if (__sen)
-        {
-            if (this->rdbuf()->pubseekoff(__off, __dir, ios_base::in) == pos_type(-1))
-                this->setstate(ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-ws(basic_istream<_CharT, _Traits>& __is)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __sen(__is, true);
-        if (__sen)
-        {
-            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
-            while (true)
-            {
-                typename _Traits::int_type __i = __is.rdbuf()->sgetc();
-                if (_Traits::eq_int_type(__i, _Traits::eof()))
-                {
-                   __is.setstate(ios_base::eofbit);
-                   break;
-                }
-                if (!__ct.is(__ct.space, _Traits::to_char_type(__i)))
-                    break;
-                __is.rdbuf()->sbumpc();
-            }
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>&& __is, _Tp&& __x)
-{
-    __is >> _VSTD::forward<_Tp>(__x);
-    return __is;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_iostream
-    : public basic_istream<_CharT, _Traits>,
-      public basic_ostream<_CharT, _Traits>
-{
-public:
-    // types:
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    // constructor/destructor
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    explicit basic_iostream(basic_streambuf<char_type, traits_type>* __sb)
-      : basic_istream<_CharT, _Traits>(__sb)
-    {}
-
-    virtual ~basic_iostream();
-protected:
-#ifndef _LIBCPP_CXX03_LANG
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_iostream(basic_iostream&& __rhs);
-
-    // assign/swap
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_iostream& operator=(basic_iostream&& __rhs);
-#endif
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    void swap(basic_iostream& __rhs)
-    { basic_istream<char_type, traits_type>::swap(__rhs); }
-public:
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-basic_iostream<_CharT, _Traits>::basic_iostream(basic_iostream&& __rhs)
-    : basic_istream<_CharT, _Traits>(_VSTD::move(__rhs))
-{
-}
-
-template <class _CharT, class _Traits>
-basic_iostream<_CharT, _Traits>&
-basic_iostream<_CharT, _Traits>::operator=(basic_iostream&& __rhs)
-{
-    swap(__rhs);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-basic_iostream<_CharT, _Traits>::~basic_iostream()
-{
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           basic_string<_CharT, _Traits, _Allocator>& __str)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __sen(__is);
-        if (__sen)
-        {
-            __str.clear();
-            streamsize __n = __is.width();
-            if (__n <= 0)
-                __n = __str.max_size();
-            if (__n <= 0)
-                __n = numeric_limits<streamsize>::max();
-            streamsize __c = 0;
-            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
-            ios_base::iostate __err = ios_base::goodbit;
-            while (__c < __n)
-            {
-                typename _Traits::int_type __i = __is.rdbuf()->sgetc();
-                if (_Traits::eq_int_type(__i, _Traits::eof()))
-                {
-                   __err |= ios_base::eofbit;
-                   break;
-                }
-                _CharT __ch = _Traits::to_char_type(__i);
-                if (__ct.is(__ct.space, __ch))
-                    break;
-                __str.push_back(__ch);
-                ++__c;
-                 __is.rdbuf()->sbumpc();
-            }
-            __is.width(0);
-            if (__c == 0)
-               __err |= ios_base::failbit;
-            __is.setstate(__err);
-        }
-        else
-            __is.setstate(ios_base::failbit);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_istream<_CharT, _Traits>&
-getline(basic_istream<_CharT, _Traits>& __is,
-        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __sen(__is, true);
-        if (__sen)
-        {
-            __str.clear();
-            ios_base::iostate __err = ios_base::goodbit;
-            streamsize __extr = 0;
-            while (true)
-            {
-                typename _Traits::int_type __i = __is.rdbuf()->sbumpc();
-                if (_Traits::eq_int_type(__i, _Traits::eof()))
-                {
-                   __err |= ios_base::eofbit;
-                   break;
-                }
-                ++__extr;
-                _CharT __ch = _Traits::to_char_type(__i);
-                if (_Traits::eq(__ch, __dlm))
-                    break;
-                __str.push_back(__ch);
-                if (__str.size() == __str.max_size())
-                {
-                    __err |= ios_base::failbit;
-                    break;
-                }
-            }
-            if (__extr == 0)
-               __err |= ios_base::failbit;
-            __is.setstate(__err);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-getline(basic_istream<_CharT, _Traits>& __is,
-        basic_string<_CharT, _Traits, _Allocator>& __str)
-{
-    return getline(__is, __str, __is.widen('\n'));
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-getline(basic_istream<_CharT, _Traits>&& __is,
-        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm)
-{
-    return getline(__is, __str, __dlm);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-getline(basic_istream<_CharT, _Traits>&& __is,
-        basic_string<_CharT, _Traits, _Allocator>& __str)
-{
-    return getline(__is, __str, __is.widen('\n'));
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, size_t _Size>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, bitset<_Size>& __x)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_istream<_CharT, _Traits>::sentry __sen(__is);
-        if (__sen)
-        {
-            basic_string<_CharT, _Traits> __str;
-            const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__is.getloc());
-            size_t __c = 0;
-            ios_base::iostate __err = ios_base::goodbit;
-            _CharT __zero = __ct.widen('0');
-            _CharT __one = __ct.widen('1');
-            while (__c < _Size)
-            {
-                typename _Traits::int_type __i = __is.rdbuf()->sgetc();
-                if (_Traits::eq_int_type(__i, _Traits::eof()))
-                {
-                   __err |= ios_base::eofbit;
-                   break;
-                }
-                _CharT __ch = _Traits::to_char_type(__i);
-                if (!_Traits::eq(__ch, __zero) && !_Traits::eq(__ch, __one))
-                    break;
-                __str.push_back(__ch);
-                ++__c;
-                 __is.rdbuf()->sbumpc();
-            }
-            __x = bitset<_Size>(__str);
-            if (__c == 0)
-               __err |= ios_base::failbit;
-            __is.setstate(__err);
-        }
-        else
-            __is.setstate(ios_base::failbit);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __is.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __is;
-}
-
-#ifndef _LIBCPP_DO_NOT_ASSUME_STREAMS_EXPLICIT_INSTANTIATION_IN_DYLIB
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_istream<char>)
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_istream<wchar_t>)
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_iostream<char>)
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_ISTREAM
diff --git a/lib/libcxx/include/iterator b/lib/libcxx/include/iterator
deleted file mode 100644
index bda177e11e6..00000000000
--- a/lib/libcxx/include/iterator
+++ /dev/null
@@ -1,1903 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- iterator ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_ITERATOR
-#define _LIBCPP_ITERATOR
-
-/*
-    iterator synopsis
-
-namespace std
-{
-
-template<class Iterator>
-struct iterator_traits
-{
-    typedef typename Iterator::difference_type difference_type;
-    typedef typename Iterator::value_type value_type;
-    typedef typename Iterator::pointer pointer;
-    typedef typename Iterator::reference reference;
-    typedef typename Iterator::iterator_category iterator_category;
-};
-
-template<class T>
-struct iterator_traits<T*>
-{
-    typedef ptrdiff_t difference_type;
-    typedef T value_type;
-    typedef T* pointer;
-    typedef T& reference;
-    typedef random_access_iterator_tag iterator_category;
-};
-
-template<class Category, class T, class Distance = ptrdiff_t,
-         class Pointer = T*, class Reference = T&>
-struct iterator
-{
-    typedef T         value_type;
-    typedef Distance  difference_type;
-    typedef Pointer   pointer;
-    typedef Reference reference;
-    typedef Category  iterator_category;
-};
-
-struct input_iterator_tag  {};
-struct output_iterator_tag {};
-struct forward_iterator_tag       : public input_iterator_tag         {};
-struct bidirectional_iterator_tag : public forward_iterator_tag       {};
-struct random_access_iterator_tag : public bidirectional_iterator_tag {};
-
-// 27.4.3, iterator operations
-// extension: second argument not conforming to C++03
-template <class InputIterator>  // constexpr in C++17
-  constexpr void advance(InputIterator& i,
-             typename iterator_traits<InputIterator>::difference_type n);
-
-template <class InputIterator>  // constexpr in C++17
-  constexpr typename iterator_traits<InputIterator>::difference_type
-    distance(InputIterator first, InputIterator last);
-
-template <class InputIterator>  // constexpr in C++17
-  constexpr InputIterator next(InputIterator x,
-typename iterator_traits<InputIterator>::difference_type n = 1);
-
-template <class BidirectionalIterator>  // constexpr in C++17
-  constexpr BidirectionalIterator prev(BidirectionalIterator x,
-    typename iterator_traits<BidirectionalIterator>::difference_type n = 1);    
-
-template <class Iterator>
-class reverse_iterator
-    : public iterator<typename iterator_traits<Iterator>::iterator_category,
-                      typename iterator_traits<Iterator>::value_type,
-                      typename iterator_traits<Iterator>::difference_type,
-                      typename iterator_traits<Iterator>::pointer,
-                      typename iterator_traits<Iterator>::reference>
-{
-protected:
-    Iterator current;
-public:
-    typedef Iterator                                            iterator_type;
-    typedef typename iterator_traits<Iterator>::difference_type difference_type;
-    typedef typename iterator_traits<Iterator>::reference       reference;
-    typedef typename iterator_traits<Iterator>::pointer         pointer;
-
-    constexpr reverse_iterator();
-    constexpr explicit reverse_iterator(Iterator x);
-    template <class U> constexpr reverse_iterator(const reverse_iterator<U>& u);
-    template <class U> constexpr reverse_iterator& operator=(const reverse_iterator<U>& u);
-    constexpr Iterator base() const;
-    constexpr reference operator*() const;
-    constexpr pointer   operator->() const;
-    constexpr reverse_iterator& operator++();
-    constexpr reverse_iterator  operator++(int);
-    constexpr reverse_iterator& operator--();
-    constexpr reverse_iterator  operator--(int);
-    constexpr reverse_iterator  operator+ (difference_type n) const;
-    constexpr reverse_iterator& operator+=(difference_type n);
-    constexpr reverse_iterator  operator- (difference_type n) const;
-    constexpr reverse_iterator& operator-=(difference_type n);
-    constexpr reference         operator[](difference_type n) const;
-};
-
-template <class Iterator1, class Iterator2>
-constexpr bool                          // constexpr in C++17
-operator==(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool                          // constexpr in C++17
-operator<(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool                          // constexpr in C++17
-operator!=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool                          // constexpr in C++17
-operator>(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool                          // constexpr in C++17
-operator>=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool                          // constexpr in C++17
-operator<=(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr auto
-operator-(const reverse_iterator<Iterator1>& x, const reverse_iterator<Iterator2>& y)
--> decltype(__y.base() - __x.base());   // constexpr in C++17
-
-template <class Iterator>
-constexpr reverse_iterator<Iterator>
-operator+(typename reverse_iterator<Iterator>::difference_type n, 
-          const reverse_iterator<Iterator>& x);   // constexpr in C++17
-
-template <class Iterator>
-constexpr reverse_iterator<Iterator> make_reverse_iterator(Iterator i); // C++14, constexpr in C++17
-
-template <class Container>
-class back_insert_iterator
-{
-protected:
-    Container* container;
-public:
-    typedef Container                   container_type;
-    typedef void                        value_type;
-    typedef void                        difference_type;
-    typedef void                        reference;
-    typedef void                        pointer;
-
-    explicit back_insert_iterator(Container& x);
-    back_insert_iterator& operator=(const typename Container::value_type& value);
-    back_insert_iterator& operator*();
-    back_insert_iterator& operator++();
-    back_insert_iterator  operator++(int);
-};
-
-template <class Container> back_insert_iterator<Container> back_inserter(Container& x);
-
-template <class Container>
-class front_insert_iterator
-{
-protected:
-    Container* container;
-public:
-    typedef Container                    container_type;
-    typedef void                         value_type;
-    typedef void                         difference_type;
-    typedef void                         reference;
-    typedef void                         pointer;
-
-    explicit front_insert_iterator(Container& x);
-    front_insert_iterator& operator=(const typename Container::value_type& value);
-    front_insert_iterator& operator*();
-    front_insert_iterator& operator++();
-    front_insert_iterator  operator++(int);
-};
-
-template <class Container> front_insert_iterator<Container> front_inserter(Container& x);
-
-template <class Container>
-class insert_iterator
-{
-protected:
-    Container* container;
-    typename Container::iterator iter;
-public:
-    typedef Container              container_type;
-    typedef void                   value_type;
-    typedef void                   difference_type;
-    typedef void                   reference;
-    typedef void                   pointer;
-
-    insert_iterator(Container& x, typename Container::iterator i);
-    insert_iterator& operator=(const typename Container::value_type& value);
-    insert_iterator& operator*();
-    insert_iterator& operator++();
-    insert_iterator& operator++(int);
-};
-
-template <class Container, class Iterator>
-insert_iterator<Container> inserter(Container& x, Iterator i);
-
-template <class Iterator>
-class move_iterator {
-public:
-    typedef Iterator                                              iterator_type;
-    typedef typename iterator_traits<Iterator>::difference_type   difference_type;
-    typedef Iterator                                              pointer;
-    typedef typename iterator_traits<Iterator>::value_type        value_type;
-    typedef typename iterator_traits<Iterator>::iterator_category iterator_category;
-    typedef value_type&&                                          reference;
- 
-    constexpr move_iterator();  // all the constexprs are in C++17
-    constexpr explicit move_iterator(Iterator i);
-    template <class U>
-      constexpr move_iterator(const move_iterator<U>& u);
-    template <class U>
-      constexpr move_iterator& operator=(const move_iterator<U>& u);
-    constexpr iterator_type base() const;
-    constexpr reference operator*() const;
-    constexpr pointer operator->() const;
-    constexpr move_iterator& operator++();
-    constexpr move_iterator operator++(int);
-    constexpr move_iterator& operator--();
-    constexpr move_iterator operator--(int);
-    constexpr move_iterator operator+(difference_type n) const; 
-    constexpr move_iterator& operator+=(difference_type n); 
-    constexpr move_iterator operator-(difference_type n) const; 
-    constexpr move_iterator& operator-=(difference_type n); 
-    constexpr unspecified operator[](difference_type n) const;
-private:
-    Iterator current; // exposition only
-};
-
-template <class Iterator1, class Iterator2>
-constexpr bool   // constexpr in C++17
-operator==(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool   // constexpr in C++17
-operator!=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool   // constexpr in C++17
-operator<(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool   // constexpr in C++17
-operator<=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool   // constexpr in C++17
-operator>(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr bool   // constexpr in C++17
-operator>=(const move_iterator<Iterator1>& x, const move_iterator<Iterator2>& y);
-
-template <class Iterator1, class Iterator2>
-constexpr auto   // constexpr in C++17
-operator-(const move_iterator<Iterator1>& x,
-          const move_iterator<Iterator2>& y) -> decltype(x.base() - y.base());
-
-template <class Iterator>
-constexpr move_iterator<Iterator> operator+(   // constexpr in C++17
-            typename move_iterator<Iterator>::difference_type n, 
-            const move_iterator<Iterator>& x);
-
-template <class Iterator>   // constexpr in C++17
-constexpr  move_iterator<Iterator> make_move_iterator(const Iterator& i);
-
-
-template <class T, class charT = char, class traits = char_traits<charT>, class Distance = ptrdiff_t>
-class istream_iterator
-    : public iterator<input_iterator_tag, T, Distance, const T*, const T&>
-{
-public:
-    typedef charT char_type;
-    typedef traits traits_type;
-    typedef basic_istream<charT,traits> istream_type;
-
-    constexpr istream_iterator();
-    istream_iterator(istream_type& s);
-    istream_iterator(const istream_iterator& x);
-    ~istream_iterator();
-
-    const T& operator*() const;
-    const T* operator->() const;
-    istream_iterator& operator++();
-    istream_iterator  operator++(int);
-};
-
-template <class T, class charT, class traits, class Distance>
-bool operator==(const istream_iterator<T,charT,traits,Distance>& x,
-                const istream_iterator<T,charT,traits,Distance>& y);
-template <class T, class charT, class traits, class Distance>
-bool operator!=(const istream_iterator<T,charT,traits,Distance>& x,
-                const istream_iterator<T,charT,traits,Distance>& y);
-
-template <class T, class charT = char, class traits = char_traits<charT> >
-class ostream_iterator
-    : public iterator<output_iterator_tag, void, void, void ,void>
-{
-public:
-    typedef charT char_type;
-    typedef traits traits_type;
-    typedef basic_ostream<charT,traits> ostream_type;
-
-    ostream_iterator(ostream_type& s);
-    ostream_iterator(ostream_type& s, const charT* delimiter);
-    ostream_iterator(const ostream_iterator& x);
-    ~ostream_iterator();
-    ostream_iterator& operator=(const T& value);
-
-    ostream_iterator& operator*();
-    ostream_iterator& operator++();
-    ostream_iterator& operator++(int);
-};
-
-template<class charT, class traits = char_traits<charT> >
-class istreambuf_iterator
-    : public iterator<input_iterator_tag, charT,
-                      typename traits::off_type, unspecified,
-                      charT>
-{
-public:
-    typedef charT                         char_type;
-    typedef traits                        traits_type;
-    typedef typename traits::int_type     int_type;
-    typedef basic_streambuf<charT,traits> streambuf_type;
-    typedef basic_istream<charT,traits>   istream_type;
-
-    istreambuf_iterator() noexcept;
-    istreambuf_iterator(istream_type& s) noexcept;
-    istreambuf_iterator(streambuf_type* s) noexcept;
-    istreambuf_iterator(a-private-type) noexcept;
-
-    charT                operator*() const;
-    pointer operator->() const;
-    istreambuf_iterator& operator++();
-    a-private-type       operator++(int);
-
-    bool equal(const istreambuf_iterator& b) const;
-};
-
-template <class charT, class traits>
-bool operator==(const istreambuf_iterator<charT,traits>& a,
-                const istreambuf_iterator<charT,traits>& b);
-template <class charT, class traits>
-bool operator!=(const istreambuf_iterator<charT,traits>& a,
-                const istreambuf_iterator<charT,traits>& b);
-
-template <class charT, class traits = char_traits<charT> >
-class ostreambuf_iterator
-    : public iterator<output_iterator_tag, void, void, void, void>
-{
-public:
-    typedef charT                         char_type;
-    typedef traits                        traits_type;
-    typedef basic_streambuf<charT,traits> streambuf_type;
-    typedef basic_ostream<charT,traits>   ostream_type;
-
-    ostreambuf_iterator(ostream_type& s) noexcept;
-    ostreambuf_iterator(streambuf_type* s) noexcept;
-    ostreambuf_iterator& operator=(charT c);
-    ostreambuf_iterator& operator*();
-    ostreambuf_iterator& operator++();
-    ostreambuf_iterator& operator++(int);
-    bool failed() const noexcept;
-};
-
-template <class C> constexpr auto begin(C& c) -> decltype(c.begin());
-template <class C> constexpr auto begin(const C& c) -> decltype(c.begin());
-template <class C> constexpr auto end(C& c) -> decltype(c.end());
-template <class C> constexpr auto end(const C& c) -> decltype(c.end());
-template <class T, size_t N> constexpr T* begin(T (&array)[N]);
-template <class T, size_t N> constexpr T* end(T (&array)[N]);
-
-template <class C> auto constexpr cbegin(const C& c) -> decltype(std::begin(c));        // C++14
-template <class C> auto constexpr cend(const C& c) -> decltype(std::end(c));            // C++14
-template <class C> auto constexpr rbegin(C& c) -> decltype(c.rbegin());                 // C++14
-template <class C> auto constexpr rbegin(const C& c) -> decltype(c.rbegin());           // C++14
-template <class C> auto constexpr rend(C& c) -> decltype(c.rend());                     // C++14
-template <class C> constexpr auto rend(const C& c) -> decltype(c.rend());               // C++14
-template <class E> reverse_iterator<const E*> constexpr rbegin(initializer_list<E> il); // C++14
-template <class E> reverse_iterator<const E*> constexpr rend(initializer_list<E> il);   // C++14
-template <class T, size_t N> reverse_iterator<T*> constexpr rbegin(T (&array)[N]);      // C++14
-template <class T, size_t N> reverse_iterator<T*> constexpr rend(T (&array)[N]);        // C++14
-template <class C> constexpr auto crbegin(const C& c) -> decltype(std::rbegin(c));      // C++14
-template <class C> constexpr auto crend(const C& c) -> decltype(std::rend(c));          // C++14
-
-// 24.8, container access:
-template <class C> constexpr auto size(const C& c) -> decltype(c.size());         // C++17
-template <class T, size_t N> constexpr size_t size(const T (&array)[N]) noexcept; // C++17
-template <class C> constexpr auto empty(const C& c) -> decltype(c.empty());       // C++17
-template <class T, size_t N> constexpr bool empty(const T (&array)[N]) noexcept;  // C++17
-template <class E> constexpr bool empty(initializer_list<E> il) noexcept;         // C++17
-template <class C> constexpr auto data(C& c) -> decltype(c.data());               // C++17
-template <class C> constexpr auto data(const C& c) -> decltype(c.data());         // C++17
-template <class T, size_t N> constexpr T* data(T (&array)[N]) noexcept;           // C++17
-template <class E> constexpr const E* data(initializer_list<E> il) noexcept;      // C++17
-
-}  // std
-
-*/
-
-#include <__config>
-#include <iosfwd> // for forward declarations of vector and string.
-#include <__functional_base>
-#include <type_traits>
-#include <cstddef>
-#include <initializer_list>
-#include <version>
-#ifdef __APPLE__
-#include <Availability.h>
-#endif
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-struct _LIBCPP_TEMPLATE_VIS input_iterator_tag {};
-struct _LIBCPP_TEMPLATE_VIS output_iterator_tag {};
-struct _LIBCPP_TEMPLATE_VIS forward_iterator_tag       : public input_iterator_tag {};
-struct _LIBCPP_TEMPLATE_VIS bidirectional_iterator_tag : public forward_iterator_tag {};
-struct _LIBCPP_TEMPLATE_VIS random_access_iterator_tag : public bidirectional_iterator_tag {};
-
-template <class _Tp>
-struct __has_iterator_typedefs
-{
-private:
-    struct __two {char __lx; char __lxx;};
-    template <class _Up> static __two __test(...);
-    template <class _Up> static char __test(typename std::__void_t<typename _Up::iterator_category>::type* = 0,
-    										typename std::__void_t<typename _Up::difference_type>::type* = 0,
-    										typename std::__void_t<typename _Up::value_type>::type* = 0,
-    										typename std::__void_t<typename _Up::reference>::type* = 0,
-    										typename std::__void_t<typename _Up::pointer>::type* = 0
-    										);
-public:
-    static const bool value = sizeof(__test<_Tp>(0,0,0,0,0)) == 1;
-};
-
-
-template <class _Tp>
-struct __has_iterator_category
-{
-private:
-    struct __two {char __lx; char __lxx;};
-    template <class _Up> static __two __test(...);
-    template <class _Up> static char __test(typename _Up::iterator_category* = 0);
-public:
-    static const bool value = sizeof(__test<_Tp>(0)) == 1;
-};
-
-template <class _Iter, bool> struct __iterator_traits_impl {};
-
-template <class _Iter>
-struct __iterator_traits_impl<_Iter, true>
-{
-    typedef typename _Iter::difference_type   difference_type;
-    typedef typename _Iter::value_type        value_type;
-    typedef typename _Iter::pointer           pointer;
-    typedef typename _Iter::reference         reference;
-    typedef typename _Iter::iterator_category iterator_category;
-};
-
-template <class _Iter, bool> struct __iterator_traits {};
-
-template <class _Iter>
-struct __iterator_traits<_Iter, true>
-    :  __iterator_traits_impl
-      <
-        _Iter,
-        is_convertible<typename _Iter::iterator_category, input_iterator_tag>::value ||
-        is_convertible<typename _Iter::iterator_category, output_iterator_tag>::value
-      >
-{};
-
-// iterator_traits<Iterator> will only have the nested types if Iterator::iterator_category
-//    exists.  Else iterator_traits<Iterator> will be an empty class.  This is a
-//    conforming extension which allows some programs to compile and behave as
-//    the client expects instead of failing at compile time.
-
-template <class _Iter>
-struct _LIBCPP_TEMPLATE_VIS iterator_traits
-    : __iterator_traits<_Iter, __has_iterator_typedefs<_Iter>::value> {};
-
-template<class _Tp>
-struct _LIBCPP_TEMPLATE_VIS iterator_traits<_Tp*>
-{
-    typedef ptrdiff_t difference_type;
-    typedef typename remove_cv<_Tp>::type value_type;
-    typedef _Tp* pointer;
-    typedef _Tp& reference;
-    typedef random_access_iterator_tag iterator_category;
-};
-
-template <class _Tp, class _Up, bool = __has_iterator_category<iterator_traits<_Tp> >::value>
-struct __has_iterator_category_convertible_to
-    : public integral_constant<bool, is_convertible<typename iterator_traits<_Tp>::iterator_category, _Up>::value>
-{};
-
-template <class _Tp, class _Up>
-struct __has_iterator_category_convertible_to<_Tp, _Up, false> : public false_type {};
-
-template <class _Tp>
-struct __is_input_iterator : public __has_iterator_category_convertible_to<_Tp, input_iterator_tag> {};
-
-template <class _Tp>
-struct __is_forward_iterator : public __has_iterator_category_convertible_to<_Tp, forward_iterator_tag> {};
-
-template <class _Tp>
-struct __is_bidirectional_iterator : public __has_iterator_category_convertible_to<_Tp, bidirectional_iterator_tag> {};
-
-template <class _Tp>
-struct __is_random_access_iterator : public __has_iterator_category_convertible_to<_Tp, random_access_iterator_tag> {};
-
-template <class _Tp>
-struct __is_exactly_input_iterator
-    : public integral_constant<bool, 
-         __has_iterator_category_convertible_to<_Tp, input_iterator_tag>::value && 
-        !__has_iterator_category_convertible_to<_Tp, forward_iterator_tag>::value> {};
-
-template<class _Category, class _Tp, class _Distance = ptrdiff_t,
-         class _Pointer = _Tp*, class _Reference = _Tp&>
-struct _LIBCPP_TEMPLATE_VIS iterator
-{
-    typedef _Tp        value_type;
-    typedef _Distance  difference_type;
-    typedef _Pointer   pointer;
-    typedef _Reference reference;
-    typedef _Category  iterator_category;
-};
-
-template <class _InputIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-void __advance(_InputIter& __i,
-             typename iterator_traits<_InputIter>::difference_type __n, input_iterator_tag)
-{
-    for (; __n > 0; --__n)
-        ++__i;
-}
-
-template <class _BiDirIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-void __advance(_BiDirIter& __i,
-             typename iterator_traits<_BiDirIter>::difference_type __n, bidirectional_iterator_tag)
-{
-    if (__n >= 0)
-        for (; __n > 0; --__n)
-            ++__i;
-    else
-        for (; __n < 0; ++__n)
-            --__i;
-}
-
-template <class _RandIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-void __advance(_RandIter& __i,
-             typename iterator_traits<_RandIter>::difference_type __n, random_access_iterator_tag)
-{
-   __i += __n;
-}
-
-template <class _InputIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-void advance(_InputIter& __i,
-             typename iterator_traits<_InputIter>::difference_type __n)
-{
-    __advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category());
-}
-
-template <class _InputIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-typename iterator_traits<_InputIter>::difference_type
-__distance(_InputIter __first, _InputIter __last, input_iterator_tag)
-{
-    typename iterator_traits<_InputIter>::difference_type __r(0);
-    for (; __first != __last; ++__first)
-        ++__r;
-    return __r;
-}
-
-template <class _RandIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-typename iterator_traits<_RandIter>::difference_type
-__distance(_RandIter __first, _RandIter __last, random_access_iterator_tag)
-{
-    return __last - __first;
-}
-
-template <class _InputIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-typename iterator_traits<_InputIter>::difference_type
-distance(_InputIter __first, _InputIter __last)
-{
-    return __distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());
-}
-
-template <class _InputIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-typename enable_if
-<
-    __is_input_iterator<_InputIter>::value, 
-    _InputIter
->::type
-next(_InputIter __x,
-     typename iterator_traits<_InputIter>::difference_type __n = 1)
-{
-    _VSTD::advance(__x, __n);
-    return __x;
-}
-
-template <class _BidirectionalIter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-typename enable_if
-<
-    __is_bidirectional_iterator<_BidirectionalIter>::value, 
-    _BidirectionalIter
->::type
-prev(_BidirectionalIter __x,
-     typename iterator_traits<_BidirectionalIter>::difference_type __n = 1)
-{
-    _VSTD::advance(__x, -__n);
-    return __x;
-}
-
-
-template <class _Tp, class = void>
-struct __is_stashing_iterator : false_type {};
-
-template <class _Tp>
-struct __is_stashing_iterator<_Tp, typename __void_t<typename _Tp::__stashing_iterator_tag>::type>
-  : true_type {};
-
-template <class _Iter>
-class _LIBCPP_TEMPLATE_VIS reverse_iterator
-    : public iterator<typename iterator_traits<_Iter>::iterator_category,
-                      typename iterator_traits<_Iter>::value_type,
-                      typename iterator_traits<_Iter>::difference_type,
-                      typename iterator_traits<_Iter>::pointer,
-                      typename iterator_traits<_Iter>::reference>
-{
-private:
-    /*mutable*/ _Iter __t;  // no longer used as of LWG #2360, not removed due to ABI break
-
-    static_assert(!__is_stashing_iterator<_Iter>::value,
-      "The specified iterator type cannot be used with reverse_iterator; "
-      "Using stashing iterators with reverse_iterator causes undefined behavior");
-
-protected:
-    _Iter current;
-public:
-    typedef _Iter                                            iterator_type;
-    typedef typename iterator_traits<_Iter>::difference_type difference_type;
-    typedef typename iterator_traits<_Iter>::reference       reference;
-    typedef typename iterator_traits<_Iter>::pointer         pointer;
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator() : __t(), current() {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    explicit reverse_iterator(_Iter __x) : __t(__x), current(__x) {}
-    template <class _Up>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-        reverse_iterator(const reverse_iterator<_Up>& __u) : __t(__u.base()), current(__u.base()) {}
-    template <class _Up>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-        reverse_iterator& operator=(const reverse_iterator<_Up>& __u)
-            { __t = current = __u.base(); return *this; }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    _Iter base() const {return current;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reference operator*() const {_Iter __tmp = current; return *--__tmp;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    pointer  operator->() const {return _VSTD::addressof(operator*());}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator& operator++() {--current; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator  operator++(int) {reverse_iterator __tmp(*this); --current; return __tmp;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator& operator--() {++current; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator  operator--(int) {reverse_iterator __tmp(*this); ++current; return __tmp;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator  operator+ (difference_type __n) const {return reverse_iterator(current - __n);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator& operator+=(difference_type __n) {current -= __n; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator  operator- (difference_type __n) const {return reverse_iterator(current + __n);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reverse_iterator& operator-=(difference_type __n) {current += __n; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reference         operator[](difference_type __n) const {return *(*this + __n);}
-};
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator==(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
-{
-    return __x.base() == __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator<(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
-{
-    return __x.base() > __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator!=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
-{
-    return __x.base() != __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator>(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
-{
-    return __x.base() < __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator>=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
-{
-    return __x.base() <= __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator<=(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
-{
-    return __x.base() >= __y.base();
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto
-operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
--> decltype(__y.base() - __x.base())
-{
-    return __y.base() - __x.base();
-}
-#else
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename reverse_iterator<_Iter1>::difference_type
-operator-(const reverse_iterator<_Iter1>& __x, const reverse_iterator<_Iter2>& __y)
-{
-    return __y.base() - __x.base();
-}
-#endif
-
-template <class _Iter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-reverse_iterator<_Iter>
-operator+(typename reverse_iterator<_Iter>::difference_type __n, const reverse_iterator<_Iter>& __x)
-{
-    return reverse_iterator<_Iter>(__x.base() - __n);
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _Iter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-reverse_iterator<_Iter> make_reverse_iterator(_Iter __i)
-{
-    return reverse_iterator<_Iter>(__i);
-}
-#endif
-
-template <class _Container>
-class _LIBCPP_TEMPLATE_VIS back_insert_iterator
-    : public iterator<output_iterator_tag,
-                      void,
-                      void,
-                      void,
-                      void>
-{
-protected:
-    _Container* container;
-public:
-    typedef _Container container_type;
-
-    _LIBCPP_INLINE_VISIBILITY explicit back_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
-    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(const typename _Container::value_type& __value_)
-        {container->push_back(__value_); return *this;}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator=(typename _Container::value_type&& __value_)
-        {container->push_back(_VSTD::move(__value_)); return *this;}
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator*()     {return *this;}
-    _LIBCPP_INLINE_VISIBILITY back_insert_iterator& operator++()    {return *this;}
-    _LIBCPP_INLINE_VISIBILITY back_insert_iterator  operator++(int) {return *this;}
-};
-
-template <class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-back_insert_iterator<_Container>
-back_inserter(_Container& __x)
-{
-    return back_insert_iterator<_Container>(__x);
-}
-
-template <class _Container>
-class _LIBCPP_TEMPLATE_VIS front_insert_iterator
-    : public iterator<output_iterator_tag,
-                      void,
-                      void,
-                      void,
-                      void>
-{
-protected:
-    _Container* container;
-public:
-    typedef _Container container_type;
-
-    _LIBCPP_INLINE_VISIBILITY explicit front_insert_iterator(_Container& __x) : container(_VSTD::addressof(__x)) {}
-    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(const typename _Container::value_type& __value_)
-        {container->push_front(__value_); return *this;}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator=(typename _Container::value_type&& __value_)
-        {container->push_front(_VSTD::move(__value_)); return *this;}
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator*()     {return *this;}
-    _LIBCPP_INLINE_VISIBILITY front_insert_iterator& operator++()    {return *this;}
-    _LIBCPP_INLINE_VISIBILITY front_insert_iterator  operator++(int) {return *this;}
-};
-
-template <class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-front_insert_iterator<_Container>
-front_inserter(_Container& __x)
-{
-    return front_insert_iterator<_Container>(__x);
-}
-
-template <class _Container>
-class _LIBCPP_TEMPLATE_VIS insert_iterator
-    : public iterator<output_iterator_tag,
-                      void,
-                      void,
-                      void,
-                      void>
-{
-protected:
-    _Container* container;
-    typename _Container::iterator iter;
-public:
-    typedef _Container container_type;
-
-    _LIBCPP_INLINE_VISIBILITY insert_iterator(_Container& __x, typename _Container::iterator __i)
-        : container(_VSTD::addressof(__x)), iter(__i) {}
-    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(const typename _Container::value_type& __value_)
-        {iter = container->insert(iter, __value_); ++iter; return *this;}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator=(typename _Container::value_type&& __value_)
-        {iter = container->insert(iter, _VSTD::move(__value_)); ++iter; return *this;}
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator*()        {return *this;}
-    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++()       {return *this;}
-    _LIBCPP_INLINE_VISIBILITY insert_iterator& operator++(int)    {return *this;}
-};
-
-template <class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-insert_iterator<_Container>
-inserter(_Container& __x, typename _Container::iterator __i)
-{
-    return insert_iterator<_Container>(__x, __i);
-}
-
-template <class _Tp, class _CharT = char,
-          class _Traits = char_traits<_CharT>, class _Distance = ptrdiff_t>
-class _LIBCPP_TEMPLATE_VIS istream_iterator
-    : public iterator<input_iterator_tag, _Tp, _Distance, const _Tp*, const _Tp&>
-{
-public:
-    typedef _CharT char_type;
-    typedef _Traits traits_type;
-    typedef basic_istream<_CharT,_Traits> istream_type;
-private:
-    istream_type* __in_stream_;
-    _Tp __value_;
-public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istream_iterator() : __in_stream_(0), __value_() {}
-    _LIBCPP_INLINE_VISIBILITY istream_iterator(istream_type& __s) : __in_stream_(_VSTD::addressof(__s))
-        {
-            if (!(*__in_stream_ >> __value_))
-                __in_stream_ = 0;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY const _Tp& operator*() const {return __value_;}
-    _LIBCPP_INLINE_VISIBILITY const _Tp* operator->() const {return _VSTD::addressof((operator*()));}
-    _LIBCPP_INLINE_VISIBILITY istream_iterator& operator++()
-        {
-            if (!(*__in_stream_ >> __value_))
-                __in_stream_ = 0;
-            return *this;
-        }
-    _LIBCPP_INLINE_VISIBILITY istream_iterator  operator++(int)
-        {istream_iterator __t(*this); ++(*this); return __t;}
-
-    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool
-    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
-               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
-
-    template <class _Up, class _CharU, class _TraitsU, class _DistanceU>
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool
-    operator==(const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __x,
-               const istream_iterator<_Up, _CharU, _TraitsU, _DistanceU>& __y);
-};
-
-template <class _Tp, class _CharT, class _Traits, class _Distance>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
-           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
-{
-    return __x.__in_stream_ == __y.__in_stream_;
-}
-
-template <class _Tp, class _CharT, class _Traits, class _Distance>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __x,
-           const istream_iterator<_Tp, _CharT, _Traits, _Distance>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Tp, class _CharT = char, class _Traits = char_traits<_CharT> >
-class _LIBCPP_TEMPLATE_VIS ostream_iterator
-    : public iterator<output_iterator_tag, void, void, void, void>
-{
-public:
-    typedef _CharT char_type;
-    typedef _Traits traits_type;
-    typedef basic_ostream<_CharT,_Traits> ostream_type;
-private:
-    ostream_type* __out_stream_;
-    const char_type* __delim_;
-public:
-    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s) _NOEXCEPT
-        : __out_stream_(_VSTD::addressof(__s)), __delim_(0) {}
-    _LIBCPP_INLINE_VISIBILITY ostream_iterator(ostream_type& __s, const _CharT* __delimiter) _NOEXCEPT
-        : __out_stream_(_VSTD::addressof(__s)), __delim_(__delimiter) {}
-    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator=(const _Tp& __value_)
-        {
-            *__out_stream_ << __value_;
-            if (__delim_)
-                *__out_stream_ << __delim_;
-            return *this;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator*()     {return *this;}
-    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++()    {return *this;}
-    _LIBCPP_INLINE_VISIBILITY ostream_iterator& operator++(int) {return *this;}
-};
-
-template<class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS istreambuf_iterator
-    : public iterator<input_iterator_tag, _CharT,
-                      typename _Traits::off_type, _CharT*,
-                      _CharT>
-{
-public:
-    typedef _CharT                          char_type;
-    typedef _Traits                         traits_type;
-    typedef typename _Traits::int_type      int_type;
-    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
-    typedef basic_istream<_CharT,_Traits>   istream_type;
-private:
-    mutable streambuf_type* __sbuf_;
-
-    class __proxy
-    {
-        char_type __keep_;
-        streambuf_type* __sbuf_;
-        _LIBCPP_INLINE_VISIBILITY __proxy(char_type __c, streambuf_type* __s)
-            : __keep_(__c), __sbuf_(__s) {}
-        friend class istreambuf_iterator;
-    public:
-        _LIBCPP_INLINE_VISIBILITY char_type operator*() const {return __keep_;}
-    };
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool __test_for_eof() const
-    {
-        if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sgetc(), traits_type::eof()))
-            __sbuf_ = 0;
-        return __sbuf_ == 0;
-    }
-public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR istreambuf_iterator() _NOEXCEPT : __sbuf_(0) {}
-    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(istream_type& __s) _NOEXCEPT
-        : __sbuf_(__s.rdbuf()) {}
-    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(streambuf_type* __s) _NOEXCEPT
-        : __sbuf_(__s) {}
-    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator(const __proxy& __p) _NOEXCEPT
-        : __sbuf_(__p.__sbuf_) {}
-
-    _LIBCPP_INLINE_VISIBILITY char_type  operator*() const
-        {return static_cast<char_type>(__sbuf_->sgetc());}
-    _LIBCPP_INLINE_VISIBILITY istreambuf_iterator& operator++()
-        {
-            __sbuf_->sbumpc();
-            return *this;
-        }
-    _LIBCPP_INLINE_VISIBILITY __proxy              operator++(int)
-        {
-            return __proxy(__sbuf_->sbumpc(), __sbuf_);
-        }
-
-    _LIBCPP_INLINE_VISIBILITY bool equal(const istreambuf_iterator& __b) const
-        {return __test_for_eof() == __b.__test_for_eof();}
-};
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(const istreambuf_iterator<_CharT,_Traits>& __a,
-                const istreambuf_iterator<_CharT,_Traits>& __b)
-                {return __a.equal(__b);}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(const istreambuf_iterator<_CharT,_Traits>& __a,
-                const istreambuf_iterator<_CharT,_Traits>& __b)
-                {return !__a.equal(__b);}
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS ostreambuf_iterator
-    : public iterator<output_iterator_tag, void, void, void, void>
-{
-public:
-    typedef _CharT                          char_type;
-    typedef _Traits                         traits_type;
-    typedef basic_streambuf<_CharT,_Traits> streambuf_type;
-    typedef basic_ostream<_CharT,_Traits>   ostream_type;
-private:
-    streambuf_type* __sbuf_;
-public:
-    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(ostream_type& __s) _NOEXCEPT
-        : __sbuf_(__s.rdbuf()) {}
-    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator(streambuf_type* __s) _NOEXCEPT
-        : __sbuf_(__s) {}
-    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator=(_CharT __c)
-        {
-            if (__sbuf_ && traits_type::eq_int_type(__sbuf_->sputc(__c), traits_type::eof()))
-                __sbuf_ = 0;
-            return *this;
-        }
-    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator*()     {return *this;}
-    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++()    {return *this;}
-    _LIBCPP_INLINE_VISIBILITY ostreambuf_iterator& operator++(int) {return *this;}
-    _LIBCPP_INLINE_VISIBILITY bool failed() const _NOEXCEPT {return __sbuf_ == 0;}
-
-#if !defined(__APPLE__) || \
-    (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED > __MAC_10_8) || \
-    (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED > __IPHONE_6_0)
-
-    template <class _Ch, class _Tr>
-    friend
-    _LIBCPP_HIDDEN
-    ostreambuf_iterator<_Ch, _Tr>
-    __pad_and_output(ostreambuf_iterator<_Ch, _Tr> __s,
-                     const _Ch* __ob, const _Ch* __op, const _Ch* __oe,
-                     ios_base& __iob, _Ch __fl);
-#endif
-};
-
-template <class _Iter>
-class _LIBCPP_TEMPLATE_VIS move_iterator
-{
-private:
-    _Iter __i;
-public:
-    typedef _Iter                                            iterator_type;
-    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
-    typedef typename iterator_traits<iterator_type>::value_type value_type;
-    typedef typename iterator_traits<iterator_type>::difference_type difference_type;
-    typedef iterator_type pointer;
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename iterator_traits<iterator_type>::reference __reference;
-    typedef typename conditional<
-            is_reference<__reference>::value,
-            typename remove_reference<__reference>::type&&,
-            __reference
-        >::type reference;
-#else
-    typedef typename iterator_traits<iterator_type>::reference reference;
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    move_iterator() : __i() {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    explicit move_iterator(_Iter __x) : __i(__x) {}
-    template <class _Up>
-      _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-      move_iterator(const move_iterator<_Up>& __u) : __i(__u.base()) {}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 _Iter base() const {return __i;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14 
-    reference operator*() const { return static_cast<reference>(*__i); }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    pointer  operator->() const { return __i;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    move_iterator& operator++() {++__i; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    move_iterator  operator++(int) {move_iterator __tmp(*this); ++__i; return __tmp;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    move_iterator& operator--() {--__i; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    move_iterator  operator--(int) {move_iterator __tmp(*this); --__i; return __tmp;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    move_iterator  operator+ (difference_type __n) const {return move_iterator(__i + __n);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    move_iterator& operator+=(difference_type __n) {__i += __n; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    move_iterator  operator- (difference_type __n) const {return move_iterator(__i - __n);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    move_iterator& operator-=(difference_type __n) {__i -= __n; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-    reference operator[](difference_type __n) const { return static_cast<reference>(__i[__n]); }
-};
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator==(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
-{
-    return __x.base() == __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator<(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
-{
-    return __x.base() < __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator!=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
-{
-    return __x.base() != __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator>(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
-{
-    return __x.base() > __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator>=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
-{
-    return __x.base() >= __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-bool
-operator<=(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
-{
-    return __x.base() <= __y.base();
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto
-operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
--> decltype(__x.base() - __y.base())
-{
-    return __x.base() - __y.base();
-}
-#else
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename move_iterator<_Iter1>::difference_type
-operator-(const move_iterator<_Iter1>& __x, const move_iterator<_Iter2>& __y)
-{
-    return __x.base() - __y.base();
-}
-#endif
-
-template <class _Iter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-move_iterator<_Iter>
-operator+(typename move_iterator<_Iter>::difference_type __n, const move_iterator<_Iter>& __x)
-{
-    return move_iterator<_Iter>(__x.base() + __n);
-}
-
-template <class _Iter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-move_iterator<_Iter>
-make_move_iterator(_Iter __i)
-{
-    return move_iterator<_Iter>(__i);
-}
-
-// __wrap_iter
-
-template <class _Iter> class __wrap_iter;
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-template <class _Iter1, class _Iter2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Iter1, class _Iter2>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-auto
-operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
--> decltype(__x.base() - __y.base());
-#else
-template <class _Iter1, class _Iter2>
-_LIBCPP_INLINE_VISIBILITY
-typename __wrap_iter<_Iter1>::difference_type
-operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-#endif
-
-template <class _Iter>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-__wrap_iter<_Iter>
-operator+(typename __wrap_iter<_Iter>::difference_type, __wrap_iter<_Iter>) _NOEXCEPT_DEBUG;
-
-template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY copy(_Ip, _Ip, _Op);
-template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY copy_backward(_B1, _B1, _B2);
-template <class _Ip, class _Op> _Op _LIBCPP_INLINE_VISIBILITY move(_Ip, _Ip, _Op);
-template <class _B1, class _B2> _B2 _LIBCPP_INLINE_VISIBILITY move_backward(_B1, _B1, _B2);
-
-#if _LIBCPP_DEBUG_LEVEL < 2
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-typename enable_if
-<
-    is_trivially_copy_assignable<_Tp>::value,
-    _Tp*
->::type
-__unwrap_iter(__wrap_iter<_Tp*>);
-
-#else
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-typename enable_if
-<
-    is_trivially_copy_assignable<_Tp>::value,
-    __wrap_iter<_Tp*>
->::type
-__unwrap_iter(__wrap_iter<_Tp*> __i);
-
-#endif
-
-template <class _Iter>
-class __wrap_iter
-{
-public:
-    typedef _Iter                                                      iterator_type;
-    typedef typename iterator_traits<iterator_type>::iterator_category iterator_category;
-    typedef typename iterator_traits<iterator_type>::value_type        value_type;
-    typedef typename iterator_traits<iterator_type>::difference_type   difference_type;
-    typedef typename iterator_traits<iterator_type>::pointer           pointer;
-    typedef typename iterator_traits<iterator_type>::reference         reference;
-private:
-    iterator_type __i;
-public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter() _NOEXCEPT_DEBUG
-#if _LIBCPP_STD_VER > 11
-                : __i{}
-#endif
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->__insert_i(this);
-#endif
-    }
-    template <class _Up> _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-        __wrap_iter(const __wrap_iter<_Up>& __u,
-            typename enable_if<is_convertible<_Up, iterator_type>::value>::type* = 0) _NOEXCEPT_DEBUG
-            : __i(__u.base())
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->__iterator_copy(this, &__u);
-#endif
-    }
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-    __wrap_iter(const __wrap_iter& __x)
-        : __i(__x.base())
-    {
-        __get_db()->__iterator_copy(this, &__x);
-    }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-    __wrap_iter& operator=(const __wrap_iter& __x)
-    {
-        if (this != &__x)
-        {
-            __get_db()->__iterator_copy(this, &__x);
-            __i = __x.__i;
-        }
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-    ~__wrap_iter()
-    {
-        __get_db()->__erase_i(this);
-    }
-#endif
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference operator*() const _NOEXCEPT_DEBUG
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to dereference a non-dereferenceable iterator");
-#endif
-        return *__i;
-    }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG pointer  operator->() const _NOEXCEPT_DEBUG
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to dereference a non-dereferenceable iterator");
-#endif
-        return (pointer)_VSTD::addressof(*__i);
-    }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator++() _NOEXCEPT_DEBUG
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to increment non-incrementable iterator");
-#endif
-        ++__i;
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator++(int) _NOEXCEPT_DEBUG
-        {__wrap_iter __tmp(*this); ++(*this); return __tmp;}
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator--() _NOEXCEPT_DEBUG
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
-                       "Attempted to decrement non-decrementable iterator");
-#endif
-        --__i;
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator--(int) _NOEXCEPT_DEBUG
-        {__wrap_iter __tmp(*this); --(*this); return __tmp;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator+ (difference_type __n) const _NOEXCEPT_DEBUG
-        {__wrap_iter __w(*this); __w += __n; return __w;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator+=(difference_type __n) _NOEXCEPT_DEBUG
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__addable(this, __n),
-                   "Attempted to add/subtract iterator outside of valid range");
-#endif
-        __i += __n;
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter  operator- (difference_type __n) const _NOEXCEPT_DEBUG
-        {return *this + (-__n);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter& operator-=(difference_type __n) _NOEXCEPT_DEBUG
-        {*this += -__n; return *this;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG reference    operator[](difference_type __n) const _NOEXCEPT_DEBUG
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__subscriptable(this, __n),
-                   "Attempted to subscript iterator outside of valid range");
-#endif
-        return __i[__n];
-    }
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG iterator_type base() const _NOEXCEPT_DEBUG {return __i;}
-
-private:
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(const void* __p, iterator_type __x) : __i(__x)
-    {
-        __get_db()->__insert_ic(this, __p);
-    }
-#else
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG __wrap_iter(iterator_type __x) _NOEXCEPT_DEBUG : __i(__x) {}
-#endif
-
-    template <class _Up> friend class __wrap_iter;
-    template <class _CharT, class _Traits, class _Alloc> friend class basic_string;
-    template <class _Tp, class _Alloc> friend class _LIBCPP_TEMPLATE_VIS vector;
-    template <class _Tp, ptrdiff_t> friend class _LIBCPP_TEMPLATE_VIS span;
-
-    template <class _Iter1, class _Iter2>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    bool
-    operator==(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-    template <class _Iter1, class _Iter2>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    bool
-    operator<(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-    template <class _Iter1, class _Iter2>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    bool
-    operator!=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-    template <class _Iter1, class _Iter2>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    bool
-    operator>(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-    template <class _Iter1, class _Iter2>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    bool
-    operator>=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-    template <class _Iter1, class _Iter2>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    bool
-    operator<=(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Iter1, class _Iter2>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    auto
-    operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
-    -> decltype(__x.base() - __y.base());
-#else
-    template <class _Iter1, class _Iter2>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    typename __wrap_iter<_Iter1>::difference_type
-    operator-(const __wrap_iter<_Iter1>&, const __wrap_iter<_Iter2>&) _NOEXCEPT_DEBUG;
-#endif
-
-    template <class _Iter1>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    __wrap_iter<_Iter1>
-    operator+(typename __wrap_iter<_Iter1>::difference_type, __wrap_iter<_Iter1>) _NOEXCEPT_DEBUG;
-
-    template <class _Ip, class _Op> friend _Op copy(_Ip, _Ip, _Op);
-    template <class _B1, class _B2> friend _B2 copy_backward(_B1, _B1, _B2);
-    template <class _Ip, class _Op> friend _Op move(_Ip, _Ip, _Op);
-    template <class _B1, class _B2> friend _B2 move_backward(_B1, _B1, _B2);
-
-#if _LIBCPP_DEBUG_LEVEL < 2
-    template <class _Tp>
-    _LIBCPP_CONSTEXPR_IF_NODEBUG friend
-    typename enable_if
-    <
-        is_trivially_copy_assignable<_Tp>::value,
-        _Tp*
-    >::type
-    __unwrap_iter(__wrap_iter<_Tp*>);
-#else
-  template <class _Tp>
-  inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-  typename enable_if
-  <
-      is_trivially_copy_assignable<_Tp>::value,
-      __wrap_iter<_Tp*>
-  >::type
-  __unwrap_iter(__wrap_iter<_Tp*> __i);
-#endif
-};
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator==(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
-{
-    return __x.base() == __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator<(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
-                   "Attempted to compare incomparable iterators");
-#endif
-    return __x.base() < __y.base();
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
-{
-    return !(__x == __y);
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
-{
-    return __y < __x;
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
-{
-    return !(__x < __y);
-}
-
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
-{
-    return !(__y < __x);
-}
-
-template <class _Iter1>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator!=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
-{
-    return !(__x == __y);
-}
-
-template <class _Iter1>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator>(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
-{
-    return __y < __x;
-}
-
-template <class _Iter1>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator>=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
-{
-    return !(__x < __y);
-}
-
-template <class _Iter1>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-bool
-operator<=(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter1>& __y) _NOEXCEPT_DEBUG
-{
-    return !(__y < __x);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-auto
-operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
--> decltype(__x.base() - __y.base())
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
-                   "Attempted to subtract incompatible iterators");
-#endif
-    return __x.base() - __y.base();
-}
-#else
-template <class _Iter1, class _Iter2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-typename __wrap_iter<_Iter1>::difference_type
-operator-(const __wrap_iter<_Iter1>& __x, const __wrap_iter<_Iter2>& __y) _NOEXCEPT_DEBUG
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__less_than_comparable(&__x, &__y),
-                   "Attempted to subtract incompatible iterators");
-#endif
-    return __x.base() - __y.base();
-}
-#endif
-
-template <class _Iter>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_IF_NODEBUG
-__wrap_iter<_Iter>
-operator+(typename __wrap_iter<_Iter>::difference_type __n,
-          __wrap_iter<_Iter> __x) _NOEXCEPT_DEBUG
-{
-    __x += __n;
-    return __x;
-}
-
-template <class _Iter>
-struct __libcpp_is_trivial_iterator
-    : public _LIBCPP_BOOL_CONSTANT(is_pointer<_Iter>::value) {};
-    
-template <class _Iter>
-struct __libcpp_is_trivial_iterator<move_iterator<_Iter> >
-    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
-
-template <class _Iter>
-struct __libcpp_is_trivial_iterator<reverse_iterator<_Iter> >
-    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
-
-template <class _Iter>
-struct __libcpp_is_trivial_iterator<__wrap_iter<_Iter> >
-    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value) {};
-
-
-template <class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp*
-begin(_Tp (&__array)[_Np])
-{
-    return __array;
-}
-
-template <class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-_Tp*
-end(_Tp (&__array)[_Np])
-{
-    return __array + _Np;
-}
-
-#if !defined(_LIBCPP_CXX03_LANG)
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto
-begin(_Cp& __c) -> decltype(__c.begin())
-{
-    return __c.begin();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto
-begin(const _Cp& __c) -> decltype(__c.begin())
-{
-    return __c.begin();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto
-end(_Cp& __c) -> decltype(__c.end())
-{
-    return __c.end();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto
-end(const _Cp& __c) -> decltype(__c.end())
-{
-    return __c.end();
-}
-
-#if _LIBCPP_STD_VER > 11
-
-template <class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-reverse_iterator<_Tp*> rbegin(_Tp (&__array)[_Np])
-{
-    return reverse_iterator<_Tp*>(__array + _Np);
-}
-
-template <class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-reverse_iterator<_Tp*> rend(_Tp (&__array)[_Np])
-{
-    return reverse_iterator<_Tp*>(__array);
-}
-
-template <class _Ep>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-reverse_iterator<const _Ep*> rbegin(initializer_list<_Ep> __il)
-{
-    return reverse_iterator<const _Ep*>(__il.end());
-}
-
-template <class _Ep>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-reverse_iterator<const _Ep*> rend(initializer_list<_Ep> __il)
-{
-    return reverse_iterator<const _Ep*>(__il.begin());
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-auto cbegin(const _Cp& __c) -> decltype(_VSTD::begin(__c))
-{
-    return _VSTD::begin(__c);
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-auto cend(const _Cp& __c) -> decltype(_VSTD::end(__c))
-{
-    return _VSTD::end(__c);
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto rbegin(_Cp& __c) -> decltype(__c.rbegin())
-{
-    return __c.rbegin();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto rbegin(const _Cp& __c) -> decltype(__c.rbegin())
-{
-    return __c.rbegin();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto rend(_Cp& __c) -> decltype(__c.rend())
-{
-    return __c.rend();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto rend(const _Cp& __c) -> decltype(__c.rend())
-{
-    return __c.rend();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto crbegin(const _Cp& __c) -> decltype(_VSTD::rbegin(__c))
-{
-    return _VSTD::rbegin(__c);
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-auto crend(const _Cp& __c) -> decltype(_VSTD::rend(__c))
-{
-    return _VSTD::rend(__c);
-}
-
-#endif
-
-
-#else  // defined(_LIBCPP_CXX03_LANG)
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename _Cp::iterator
-begin(_Cp& __c)
-{
-    return __c.begin();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename _Cp::const_iterator
-begin(const _Cp& __c)
-{
-    return __c.begin();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename _Cp::iterator
-end(_Cp& __c)
-{
-    return __c.end();
-}
-
-template <class _Cp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename _Cp::const_iterator
-end(const _Cp& __c)
-{
-    return __c.end();
-}
-
-#endif  // !defined(_LIBCPP_CXX03_LANG)
-
-#if _LIBCPP_STD_VER > 14
-
-// #if _LIBCPP_STD_VER > 11
-// template <>
-// struct _LIBCPP_TEMPLATE_VIS plus<void>
-// {
-//     template <class _T1, class _T2>
-//     _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-//     auto operator()(_T1&& __t, _T2&& __u) const
-//     _NOEXCEPT_(noexcept(_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u)))
-//     -> decltype        (_VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u))
-//         { return        _VSTD::forward<_T1>(__t) + _VSTD::forward<_T2>(__u); }
-//     typedef void is_transparent;
-// };
-// #endif
-
-template <class _Cont>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr auto size(const _Cont& __c)
-_NOEXCEPT_(noexcept(__c.size()))
--> decltype        (__c.size())
-{ return            __c.size(); }
-
-template <class _Tp, size_t _Sz>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr size_t size(const _Tp (&)[_Sz]) noexcept { return _Sz; }
-
-template <class _Cont>
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
-constexpr auto empty(const _Cont& __c)
-_NOEXCEPT_(noexcept(__c.empty()))
--> decltype        (__c.empty())
-{ return            __c.empty(); }
-
-template <class _Tp, size_t _Sz>
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool empty(const _Tp (&)[_Sz]) noexcept { return false; }
-
-template <class _Ep>
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool empty(initializer_list<_Ep> __il) noexcept { return __il.size() == 0; }
-
-template <class _Cont> constexpr
-inline _LIBCPP_INLINE_VISIBILITY
-auto data(_Cont& __c)
-_NOEXCEPT_(noexcept(__c.data()))
--> decltype        (__c.data())
-{ return            __c.data(); }
-
-template <class _Cont> constexpr
-inline _LIBCPP_INLINE_VISIBILITY
-auto data(const _Cont& __c)
-_NOEXCEPT_(noexcept(__c.data()))
--> decltype        (__c.data()) 
-{ return            __c.data(); }
-
-template <class _Tp, size_t _Sz>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _Tp* data(_Tp (&__array)[_Sz]) noexcept { return __array; }
-
-template <class _Ep>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr const _Ep* data(initializer_list<_Ep> __il) noexcept { return __il.begin(); }
-#endif
-
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_ITERATOR
diff --git a/lib/libcxx/include/limits b/lib/libcxx/include/limits
deleted file mode 100644
index 5ea9a9e6fdf..00000000000
--- a/lib/libcxx/include/limits
+++ /dev/null
@@ -1,819 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- limits ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_LIMITS
-#define _LIBCPP_LIMITS
-
-/*
-    limits synopsis
-
-namespace std
-{
-
-template<class T>
-class numeric_limits
-{
-public:
-    static constexpr bool is_specialized = false;
-    static constexpr T min() noexcept;
-    static constexpr T max() noexcept;
-    static constexpr T lowest() noexcept;
-
-    static constexpr int  digits = 0;
-    static constexpr int  digits10 = 0;
-    static constexpr int  max_digits10 = 0;
-    static constexpr bool is_signed = false;
-    static constexpr bool is_integer = false;
-    static constexpr bool is_exact = false;
-    static constexpr int  radix = 0;
-    static constexpr T epsilon() noexcept;
-    static constexpr T round_error() noexcept;
-
-    static constexpr int  min_exponent = 0;
-    static constexpr int  min_exponent10 = 0;
-    static constexpr int  max_exponent = 0;
-    static constexpr int  max_exponent10 = 0;
-
-    static constexpr bool has_infinity = false;
-    static constexpr bool has_quiet_NaN = false;
-    static constexpr bool has_signaling_NaN = false;
-    static constexpr float_denorm_style has_denorm = denorm_absent;
-    static constexpr bool has_denorm_loss = false;
-    static constexpr T infinity() noexcept;
-    static constexpr T quiet_NaN() noexcept;
-    static constexpr T signaling_NaN() noexcept;
-    static constexpr T denorm_min() noexcept;
-
-    static constexpr bool is_iec559 = false;
-    static constexpr bool is_bounded = false;
-    static constexpr bool is_modulo = false;
-
-    static constexpr bool traps = false;
-    static constexpr bool tinyness_before = false;
-    static constexpr float_round_style round_style = round_toward_zero;
-};
-
-enum float_round_style
-{
-    round_indeterminate       = -1,
-    round_toward_zero         =  0,
-    round_to_nearest          =  1,
-    round_toward_infinity     =  2,
-    round_toward_neg_infinity =  3
-};
-
-enum float_denorm_style
-{
-    denorm_indeterminate = -1,
-    denorm_absent = 0,
-    denorm_present = 1
-};
-
-template<> class numeric_limits<cv bool>;
-
-template<> class numeric_limits<cv char>;
-template<> class numeric_limits<cv signed char>;
-template<> class numeric_limits<cv unsigned char>;
-template<> class numeric_limits<cv wchar_t>;
-template<> class numeric_limits<cv char8_t>; // C++20
-template<> class numeric_limits<cv char16_t>;
-template<> class numeric_limits<cv char32_t>;
-
-template<> class numeric_limits<cv short>;
-template<> class numeric_limits<cv int>;
-template<> class numeric_limits<cv long>;
-template<> class numeric_limits<cv long long>;
-template<> class numeric_limits<cv unsigned short>;
-template<> class numeric_limits<cv unsigned int>;
-template<> class numeric_limits<cv unsigned long>;
-template<> class numeric_limits<cv unsigned long long>;
-
-template<> class numeric_limits<cv float>;
-template<> class numeric_limits<cv double>;
-template<> class numeric_limits<cv long double>;
-
-}  // std
-
-*/
-#include <__config>
-#include <type_traits>
-
-#if defined(_LIBCPP_COMPILER_MSVC)
-#include "support/win32/limits_msvc_win32.h"
-#endif // _LIBCPP_MSVCRT
-
-#if defined(__IBMCPP__)
-#include "support/ibm/limits.h"
-#endif // __IBMCPP__
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-#include <version>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-enum float_round_style
-{
-    round_indeterminate       = -1,
-    round_toward_zero         =  0,
-    round_to_nearest          =  1,
-    round_toward_infinity     =  2,
-    round_toward_neg_infinity =  3
-};
-
-enum float_denorm_style
-{
-    denorm_indeterminate = -1,
-    denorm_absent = 0,
-    denorm_present = 1
-};
-
-template <class _Tp, bool = is_arithmetic<_Tp>::value>
-class __libcpp_numeric_limits
-{
-protected:
-    typedef _Tp type;
-
-    static _LIBCPP_CONSTEXPR const  bool is_specialized = false;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return type();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return type();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return type();}
-
-    static _LIBCPP_CONSTEXPR const int  digits = 0;
-    static _LIBCPP_CONSTEXPR const int  digits10 = 0;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = 0;
-    static _LIBCPP_CONSTEXPR const bool is_signed = false;
-    static _LIBCPP_CONSTEXPR const bool is_integer = false;
-    static _LIBCPP_CONSTEXPR const bool is_exact = false;
-    static _LIBCPP_CONSTEXPR const int  radix = 0;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return type();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return type();}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = 0;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = 0;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = 0;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = 0;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = false;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = false;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = false;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_absent;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return type();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return type();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return type();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return type();}
-
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = false;
-    static _LIBCPP_CONSTEXPR const bool is_bounded = false;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
-
-    static _LIBCPP_CONSTEXPR const bool traps = false;
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_toward_zero;
-};
-
-template <class _Tp, int __digits, bool _IsSigned>
-struct __libcpp_compute_min
-{
-    static _LIBCPP_CONSTEXPR const _Tp value = _Tp(_Tp(1) << __digits);
-};
-
-template <class _Tp, int __digits>
-struct __libcpp_compute_min<_Tp, __digits, false>
-{
-    static _LIBCPP_CONSTEXPR const _Tp value = _Tp(0);
-};
-
-template <class _Tp>
-class __libcpp_numeric_limits<_Tp, true>
-{
-protected:
-    typedef _Tp type;
-
-    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
-
-    static _LIBCPP_CONSTEXPR const bool is_signed = type(-1) < type(0);
-    static _LIBCPP_CONSTEXPR const int  digits = static_cast<int>(sizeof(type) * __CHAR_BIT__ - is_signed);
-    static _LIBCPP_CONSTEXPR const int  digits10 = digits * 3 / 10;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = 0;
-    static _LIBCPP_CONSTEXPR const type __min = __libcpp_compute_min<type, digits, is_signed>::value;
-    static _LIBCPP_CONSTEXPR const type __max = is_signed ? type(type(~0) ^ __min) : type(~0);
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __min;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __max;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return min();}
-
-    static _LIBCPP_CONSTEXPR const bool is_integer = true;
-    static _LIBCPP_CONSTEXPR const bool is_exact = true;
-    static _LIBCPP_CONSTEXPR const int  radix = 2;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return type(0);}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = 0;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = 0;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = 0;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = 0;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = false;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = false;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = false;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_absent;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return type(0);}
-
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = false;
-    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = !_VSTD::is_signed<_Tp>::value;
-
-#if defined(__i386__) || defined(__x86_64__) || defined(__pnacl__) || \
-    defined(__wasm__)
-    static _LIBCPP_CONSTEXPR const bool traps = true;
-#else
-    static _LIBCPP_CONSTEXPR const bool traps = false;
-#endif
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_toward_zero;
-};
-
-template <>
-class __libcpp_numeric_limits<bool, true>
-{
-protected:
-    typedef bool type;
-
-    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
-
-    static _LIBCPP_CONSTEXPR const bool is_signed = false;
-    static _LIBCPP_CONSTEXPR const int  digits = 1;
-    static _LIBCPP_CONSTEXPR const int  digits10 = 0;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = 0;
-    static _LIBCPP_CONSTEXPR const type __min = false;
-    static _LIBCPP_CONSTEXPR const type __max = true;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __min;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __max;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return min();}
-
-    static _LIBCPP_CONSTEXPR const bool is_integer = true;
-    static _LIBCPP_CONSTEXPR const bool is_exact = true;
-    static _LIBCPP_CONSTEXPR const int  radix = 2;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return type(0);}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = 0;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = 0;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = 0;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = 0;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = false;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = false;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = false;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_absent;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return type(0);}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return type(0);}
-
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = false;
-    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
-
-    static _LIBCPP_CONSTEXPR const bool traps = false;
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_toward_zero;
-};
-
-template <>
-class __libcpp_numeric_limits<float, true>
-{
-protected:
-    typedef float type;
-
-    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
-
-    static _LIBCPP_CONSTEXPR const bool is_signed = true;
-    static _LIBCPP_CONSTEXPR const int  digits = __FLT_MANT_DIG__;
-    static _LIBCPP_CONSTEXPR const int  digits10 = __FLT_DIG__;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = 2+(digits * 30103l)/100000l;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __FLT_MIN__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __FLT_MAX__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return -max();}
-
-    static _LIBCPP_CONSTEXPR const bool is_integer = false;
-    static _LIBCPP_CONSTEXPR const bool is_exact = false;
-    static _LIBCPP_CONSTEXPR const int  radix = __FLT_RADIX__;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __FLT_EPSILON__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return 0.5F;}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = __FLT_MIN_EXP__;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __FLT_MIN_10_EXP__;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = __FLT_MAX_EXP__;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __FLT_MAX_10_EXP__;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = true;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = true;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = true;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_present;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __builtin_huge_valf();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __builtin_nanf("");}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __builtin_nansf("");}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __FLT_DENORM_MIN__;}
-
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = true;
-    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
-
-    static _LIBCPP_CONSTEXPR const bool traps = false;
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_to_nearest;
-};
-
-template <>
-class __libcpp_numeric_limits<double, true>
-{
-protected:
-    typedef double type;
-
-    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
-
-    static _LIBCPP_CONSTEXPR const bool is_signed = true;
-    static _LIBCPP_CONSTEXPR const int  digits = __DBL_MANT_DIG__;
-    static _LIBCPP_CONSTEXPR const int  digits10 = __DBL_DIG__;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = 2+(digits * 30103l)/100000l;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __DBL_MIN__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __DBL_MAX__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return -max();}
-
-    static _LIBCPP_CONSTEXPR const bool is_integer = false;
-    static _LIBCPP_CONSTEXPR const bool is_exact = false;
-    static _LIBCPP_CONSTEXPR const int  radix = __FLT_RADIX__;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __DBL_EPSILON__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return 0.5;}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = __DBL_MIN_EXP__;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __DBL_MIN_10_EXP__;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = __DBL_MAX_EXP__;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __DBL_MAX_10_EXP__;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = true;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = true;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = true;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_present;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __builtin_huge_val();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __builtin_nan("");}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __builtin_nans("");}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __DBL_DENORM_MIN__;}
-
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = true;
-    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
-
-    static _LIBCPP_CONSTEXPR const bool traps = false;
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_to_nearest;
-};
-
-template <>
-class __libcpp_numeric_limits<long double, true>
-{
-protected:
-    typedef long double type;
-
-    static _LIBCPP_CONSTEXPR const bool is_specialized = true;
-
-    static _LIBCPP_CONSTEXPR const bool is_signed = true;
-    static _LIBCPP_CONSTEXPR const int  digits = __LDBL_MANT_DIG__;
-    static _LIBCPP_CONSTEXPR const int  digits10 = __LDBL_DIG__;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = 2+(digits * 30103l)/100000l;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __LDBL_MIN__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __LDBL_MAX__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return -max();}
-
-    static _LIBCPP_CONSTEXPR const bool is_integer = false;
-    static _LIBCPP_CONSTEXPR const bool is_exact = false;
-    static _LIBCPP_CONSTEXPR const int  radix = __FLT_RADIX__;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __LDBL_EPSILON__;}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return 0.5;}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = __LDBL_MIN_EXP__;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __LDBL_MIN_10_EXP__;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = __LDBL_MAX_EXP__;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __LDBL_MAX_10_EXP__;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = true;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = true;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = true;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = denorm_present;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = false;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __builtin_huge_vall();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __builtin_nanl("");}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __builtin_nansl("");}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __LDBL_DENORM_MIN__;}
-
-#if (defined(__ppc__) || defined(__ppc64__))
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = false;
-#else
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = true;
-#endif
-    static _LIBCPP_CONSTEXPR const bool is_bounded = true;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = false;
-
-    static _LIBCPP_CONSTEXPR const bool traps = false;
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = false;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = round_to_nearest;
-};
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS numeric_limits
-    : private __libcpp_numeric_limits<typename remove_cv<_Tp>::type>
-{
-    typedef __libcpp_numeric_limits<typename remove_cv<_Tp>::type> __base;
-    typedef typename __base::type type;
-public:
-    static _LIBCPP_CONSTEXPR const bool is_specialized = __base::is_specialized;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __base::min();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __base::max();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return __base::lowest();}
-
-    static _LIBCPP_CONSTEXPR const int  digits = __base::digits;
-    static _LIBCPP_CONSTEXPR const int  digits10 = __base::digits10;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = __base::max_digits10;
-    static _LIBCPP_CONSTEXPR const bool is_signed = __base::is_signed;
-    static _LIBCPP_CONSTEXPR const bool is_integer = __base::is_integer;
-    static _LIBCPP_CONSTEXPR const bool is_exact = __base::is_exact;
-    static _LIBCPP_CONSTEXPR const int  radix = __base::radix;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __base::epsilon();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return __base::round_error();}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = __base::min_exponent;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __base::min_exponent10;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = __base::max_exponent;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __base::max_exponent10;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = __base::has_infinity;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = __base::has_quiet_NaN;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = __base::has_signaling_NaN;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = __base::has_denorm;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = __base::has_denorm_loss;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __base::infinity();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __base::quiet_NaN();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __base::signaling_NaN();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __base::denorm_min();}
-
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = __base::is_iec559;
-    static _LIBCPP_CONSTEXPR const bool is_bounded = __base::is_bounded;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = __base::is_modulo;
-
-    static _LIBCPP_CONSTEXPR const bool traps = __base::traps;
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = __base::tinyness_before;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = __base::round_style;
-};
-
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_specialized;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::digits;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::digits10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::max_digits10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_signed;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_integer;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_exact;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::radix;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::min_exponent;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::min_exponent10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::max_exponent;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<_Tp>::max_exponent10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::has_infinity;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::has_quiet_NaN;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::has_signaling_NaN;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const float_denorm_style numeric_limits<_Tp>::has_denorm;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::has_denorm_loss;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_iec559;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_bounded;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::is_modulo;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::traps;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<_Tp>::tinyness_before;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const float_round_style numeric_limits<_Tp>::round_style;
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS numeric_limits<const _Tp>
-    : private numeric_limits<_Tp>
-{
-    typedef numeric_limits<_Tp> __base;
-    typedef _Tp type;
-public:
-    static _LIBCPP_CONSTEXPR const bool is_specialized = __base::is_specialized;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __base::min();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __base::max();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return __base::lowest();}
-
-    static _LIBCPP_CONSTEXPR const int  digits = __base::digits;
-    static _LIBCPP_CONSTEXPR const int  digits10 = __base::digits10;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = __base::max_digits10;
-    static _LIBCPP_CONSTEXPR const bool is_signed = __base::is_signed;
-    static _LIBCPP_CONSTEXPR const bool is_integer = __base::is_integer;
-    static _LIBCPP_CONSTEXPR const bool is_exact = __base::is_exact;
-    static _LIBCPP_CONSTEXPR const int  radix = __base::radix;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __base::epsilon();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return __base::round_error();}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = __base::min_exponent;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __base::min_exponent10;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = __base::max_exponent;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __base::max_exponent10;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = __base::has_infinity;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = __base::has_quiet_NaN;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = __base::has_signaling_NaN;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = __base::has_denorm;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = __base::has_denorm_loss;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __base::infinity();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __base::quiet_NaN();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __base::signaling_NaN();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __base::denorm_min();}
-
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = __base::is_iec559;
-    static _LIBCPP_CONSTEXPR const bool is_bounded = __base::is_bounded;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = __base::is_modulo;
-
-    static _LIBCPP_CONSTEXPR const bool traps = __base::traps;
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = __base::tinyness_before;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = __base::round_style;
-};
-
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_specialized;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::digits;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::digits10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::max_digits10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_signed;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_integer;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_exact;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::radix;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::min_exponent;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::min_exponent10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::max_exponent;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const _Tp>::max_exponent10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::has_infinity;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::has_quiet_NaN;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::has_signaling_NaN;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const float_denorm_style numeric_limits<const _Tp>::has_denorm;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::has_denorm_loss;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_iec559;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_bounded;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::is_modulo;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::traps;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const _Tp>::tinyness_before;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const float_round_style numeric_limits<const _Tp>::round_style;
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS numeric_limits<volatile _Tp>
-    : private numeric_limits<_Tp>
-{
-    typedef numeric_limits<_Tp> __base;
-    typedef _Tp type;
-public:
-    static _LIBCPP_CONSTEXPR const bool is_specialized = __base::is_specialized;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __base::min();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __base::max();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return __base::lowest();}
-
-    static _LIBCPP_CONSTEXPR const int  digits = __base::digits;
-    static _LIBCPP_CONSTEXPR const int  digits10 = __base::digits10;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = __base::max_digits10;
-    static _LIBCPP_CONSTEXPR const bool is_signed = __base::is_signed;
-    static _LIBCPP_CONSTEXPR const bool is_integer = __base::is_integer;
-    static _LIBCPP_CONSTEXPR const bool is_exact = __base::is_exact;
-    static _LIBCPP_CONSTEXPR const int  radix = __base::radix;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __base::epsilon();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return __base::round_error();}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = __base::min_exponent;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __base::min_exponent10;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = __base::max_exponent;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __base::max_exponent10;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = __base::has_infinity;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = __base::has_quiet_NaN;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = __base::has_signaling_NaN;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = __base::has_denorm;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = __base::has_denorm_loss;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __base::infinity();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __base::quiet_NaN();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __base::signaling_NaN();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __base::denorm_min();}
-
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = __base::is_iec559;
-    static _LIBCPP_CONSTEXPR const bool is_bounded = __base::is_bounded;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = __base::is_modulo;
-
-    static _LIBCPP_CONSTEXPR const bool traps = __base::traps;
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = __base::tinyness_before;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = __base::round_style;
-};
-
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_specialized;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::digits;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::digits10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::max_digits10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_signed;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_integer;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_exact;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::radix;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::min_exponent;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::min_exponent10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::max_exponent;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<volatile _Tp>::max_exponent10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::has_infinity;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::has_quiet_NaN;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::has_signaling_NaN;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const float_denorm_style numeric_limits<volatile _Tp>::has_denorm;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::has_denorm_loss;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_iec559;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_bounded;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::is_modulo;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::traps;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<volatile _Tp>::tinyness_before;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const float_round_style numeric_limits<volatile _Tp>::round_style;
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS numeric_limits<const volatile _Tp>
-    : private numeric_limits<_Tp>
-{
-    typedef numeric_limits<_Tp> __base;
-    typedef _Tp type;
-public:
-    static _LIBCPP_CONSTEXPR const bool is_specialized = __base::is_specialized;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type min() _NOEXCEPT {return __base::min();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type max() _NOEXCEPT {return __base::max();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type lowest() _NOEXCEPT {return __base::lowest();}
-
-    static _LIBCPP_CONSTEXPR const int  digits = __base::digits;
-    static _LIBCPP_CONSTEXPR const int  digits10 = __base::digits10;
-    static _LIBCPP_CONSTEXPR const int  max_digits10 = __base::max_digits10;
-    static _LIBCPP_CONSTEXPR const bool is_signed = __base::is_signed;
-    static _LIBCPP_CONSTEXPR const bool is_integer = __base::is_integer;
-    static _LIBCPP_CONSTEXPR const bool is_exact = __base::is_exact;
-    static _LIBCPP_CONSTEXPR const int  radix = __base::radix;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type epsilon() _NOEXCEPT {return __base::epsilon();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type round_error() _NOEXCEPT {return __base::round_error();}
-
-    static _LIBCPP_CONSTEXPR const int  min_exponent = __base::min_exponent;
-    static _LIBCPP_CONSTEXPR const int  min_exponent10 = __base::min_exponent10;
-    static _LIBCPP_CONSTEXPR const int  max_exponent = __base::max_exponent;
-    static _LIBCPP_CONSTEXPR const int  max_exponent10 = __base::max_exponent10;
-
-    static _LIBCPP_CONSTEXPR const bool has_infinity = __base::has_infinity;
-    static _LIBCPP_CONSTEXPR const bool has_quiet_NaN = __base::has_quiet_NaN;
-    static _LIBCPP_CONSTEXPR const bool has_signaling_NaN = __base::has_signaling_NaN;
-    static _LIBCPP_CONSTEXPR const float_denorm_style has_denorm = __base::has_denorm;
-    static _LIBCPP_CONSTEXPR const bool has_denorm_loss = __base::has_denorm_loss;
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type infinity() _NOEXCEPT {return __base::infinity();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type quiet_NaN() _NOEXCEPT {return __base::quiet_NaN();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type signaling_NaN() _NOEXCEPT {return __base::signaling_NaN();}
-    _LIBCPP_INLINE_VISIBILITY static _LIBCPP_CONSTEXPR type denorm_min() _NOEXCEPT {return __base::denorm_min();}
-
-    static _LIBCPP_CONSTEXPR const bool is_iec559 = __base::is_iec559;
-    static _LIBCPP_CONSTEXPR const bool is_bounded = __base::is_bounded;
-    static _LIBCPP_CONSTEXPR const bool is_modulo = __base::is_modulo;
-
-    static _LIBCPP_CONSTEXPR const bool traps = __base::traps;
-    static _LIBCPP_CONSTEXPR const bool tinyness_before = __base::tinyness_before;
-    static _LIBCPP_CONSTEXPR const float_round_style round_style = __base::round_style;
-};
-
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_specialized;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::digits;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::digits10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::max_digits10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_signed;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_integer;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_exact;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::radix;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::min_exponent;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::min_exponent10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::max_exponent;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const int numeric_limits<const volatile _Tp>::max_exponent10;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::has_infinity;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::has_quiet_NaN;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::has_signaling_NaN;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const float_denorm_style numeric_limits<const volatile _Tp>::has_denorm;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::has_denorm_loss;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_iec559;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_bounded;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::is_modulo;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::traps;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const bool numeric_limits<const volatile _Tp>::tinyness_before;
-template <class _Tp>
-    _LIBCPP_CONSTEXPR const float_round_style numeric_limits<const volatile _Tp>::round_style;
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_LIMITS
diff --git a/lib/libcxx/include/limits.h b/lib/libcxx/include/limits.h
deleted file mode 100644
index 1867b104857..00000000000
--- a/lib/libcxx/include/limits.h
+++ /dev/null
@@ -1,65 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- limits.h ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_LIMITS_H
-#define _LIBCPP_LIMITS_H
-
-/*
-    limits.h synopsis
-
-Macros:
-
-    CHAR_BIT
-    SCHAR_MIN
-    SCHAR_MAX
-    UCHAR_MAX
-    CHAR_MIN
-    CHAR_MAX
-    MB_LEN_MAX
-    SHRT_MIN
-    SHRT_MAX
-    USHRT_MAX
-    INT_MIN
-    INT_MAX
-    UINT_MAX
-    LONG_MIN
-    LONG_MAX
-    ULONG_MAX
-    LLONG_MIN   // C99
-    LLONG_MAX   // C99
-    ULLONG_MAX  // C99
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifndef __GNUC__
-#include_next <limits.h>
-#else
-// GCC header limits.h recursively includes itself through another header called
-// syslimits.h for some reason. This setup breaks down if we directly
-// #include_next GCC's limits.h (reasons not entirely clear to me). Therefore,
-// we manually re-create the necessary include sequence below:
-
-// Get the system limits.h defines (force recurse into the next level)
-#define _GCC_LIMITS_H_
-#define _GCC_NEXT_LIMITS_H
-#include_next <limits.h>
-
-// Get the ISO C defines
-#undef _GCC_LIMITS_H_
-#include_next <limits.h>
-#endif // __GNUC__
-
-#endif  // _LIBCPP_LIMITS_H
diff --git a/lib/libcxx/include/list b/lib/libcxx/include/list
deleted file mode 100644
index c69e31d93a4..00000000000
--- a/lib/libcxx/include/list
+++ /dev/null
@@ -1,2474 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- list ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_LIST
-#define _LIBCPP_LIST
-
-/*
-    list synopsis
-
-namespace std
-{
-
-template <class T, class Alloc = allocator<T> >
-class list
-{
-public:
-
-    // types:
-    typedef T value_type;
-    typedef Alloc allocator_type;
-    typedef typename allocator_type::reference reference;
-    typedef typename allocator_type::const_reference const_reference;
-    typedef typename allocator_type::pointer pointer;
-    typedef typename allocator_type::const_pointer const_pointer;
-    typedef implementation-defined iterator;
-    typedef implementation-defined const_iterator;
-    typedef implementation-defined size_type;
-    typedef implementation-defined difference_type;
-    typedef reverse_iterator<iterator> reverse_iterator;
-    typedef reverse_iterator<const_iterator> const_reverse_iterator;
-
-    list()
-        noexcept(is_nothrow_default_constructible<allocator_type>::value);
-    explicit list(const allocator_type& a);
-    explicit list(size_type n);
-    explicit list(size_type n, const allocator_type& a); // C++14
-    list(size_type n, const value_type& value);
-    list(size_type n, const value_type& value, const allocator_type& a);
-    template <class Iter>
-        list(Iter first, Iter last);
-    template <class Iter>
-        list(Iter first, Iter last, const allocator_type& a);
-    list(const list& x);
-    list(const list&, const allocator_type& a);
-    list(list&& x)
-        noexcept(is_nothrow_move_constructible<allocator_type>::value);
-    list(list&&, const allocator_type& a);
-    list(initializer_list<value_type>);
-    list(initializer_list<value_type>, const allocator_type& a);
-
-    ~list();
-
-    list& operator=(const list& x);
-    list& operator=(list&& x)
-        noexcept(
-             allocator_type::propagate_on_container_move_assignment::value &&
-             is_nothrow_move_assignable<allocator_type>::value);
-    list& operator=(initializer_list<value_type>);
-    template <class Iter>
-        void assign(Iter first, Iter last);
-    void assign(size_type n, const value_type& t);
-    void assign(initializer_list<value_type>);
-
-    allocator_type get_allocator() const noexcept;
-
-    iterator begin() noexcept;
-    const_iterator begin() const noexcept;
-    iterator end() noexcept;
-    const_iterator end() const noexcept;
-    reverse_iterator rbegin() noexcept;
-    const_reverse_iterator rbegin() const noexcept;
-    reverse_iterator rend() noexcept;
-    const_reverse_iterator rend() const noexcept;
-    const_iterator cbegin() const noexcept;
-    const_iterator cend() const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend() const noexcept;
-
-    reference front();
-    const_reference front() const;
-    reference back();
-    const_reference back() const;
-
-    bool empty() const noexcept;
-    size_type size() const noexcept;
-    size_type max_size() const noexcept;
-
-    template <class... Args>
-        reference emplace_front(Args&&... args); // reference in C++17
-    void pop_front();
-    template <class... Args>
-        reference emplace_back(Args&&... args);  // reference in C++17
-    void pop_back();
-    void push_front(const value_type& x);
-    void push_front(value_type&& x);
-    void push_back(const value_type& x);
-    void push_back(value_type&& x);
-    template <class... Args>
-        iterator emplace(const_iterator position, Args&&... args);
-    iterator insert(const_iterator position, const value_type& x);
-    iterator insert(const_iterator position, value_type&& x);
-    iterator insert(const_iterator position, size_type n, const value_type& x);
-    template <class Iter>
-        iterator insert(const_iterator position, Iter first, Iter last);
-    iterator insert(const_iterator position, initializer_list<value_type> il);
-
-    iterator erase(const_iterator position);
-    iterator erase(const_iterator position, const_iterator last);
-
-    void resize(size_type sz);
-    void resize(size_type sz, const value_type& c);
-
-    void swap(list&)
-        noexcept(allocator_traits<allocator_type>::is_always_equal::value);  // C++17
-    void clear() noexcept;
-
-    void splice(const_iterator position, list& x);
-    void splice(const_iterator position, list&& x);
-    void splice(const_iterator position, list& x, const_iterator i);
-    void splice(const_iterator position, list&& x, const_iterator i);
-    void splice(const_iterator position, list& x, const_iterator first,
-                                                  const_iterator last);
-    void splice(const_iterator position, list&& x, const_iterator first,
-                                                  const_iterator last);
-
-    void remove(const value_type& value);
-    template <class Pred> void remove_if(Pred pred);
-    void unique();
-    template <class BinaryPredicate>
-        void unique(BinaryPredicate binary_pred);
-    void merge(list& x);
-    void merge(list&& x);
-    template <class Compare>
-        void merge(list& x, Compare comp);
-    template <class Compare>
-        void merge(list&& x, Compare comp);
-    void sort();
-    template <class Compare>
-        void sort(Compare comp);
-    void reverse() noexcept;
-};
-
-
-template <class InputIterator, class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
-    list(InputIterator, InputIterator, Allocator = Allocator())
-    -> list<typename iterator_traits<InputIterator>::value_type, Allocator>;  // C++17
-
-template <class T, class Alloc>
-    bool operator==(const list<T,Alloc>& x, const list<T,Alloc>& y);
-template <class T, class Alloc>
-    bool operator< (const list<T,Alloc>& x, const list<T,Alloc>& y);
-template <class T, class Alloc>
-    bool operator!=(const list<T,Alloc>& x, const list<T,Alloc>& y);
-template <class T, class Alloc>
-    bool operator> (const list<T,Alloc>& x, const list<T,Alloc>& y);
-template <class T, class Alloc>
-    bool operator>=(const list<T,Alloc>& x, const list<T,Alloc>& y);
-template <class T, class Alloc>
-    bool operator<=(const list<T,Alloc>& x, const list<T,Alloc>& y);
-
-template <class T, class Alloc>
-    void swap(list<T,Alloc>& x, list<T,Alloc>& y)
-         noexcept(noexcept(x.swap(y)));
-
-template <class T, class Allocator, class U>
-    void erase(list<T, Allocator>& c, const U& value);       // C++20
-template <class T, class Allocator, class Predicate>
-    void erase_if(list<T, Allocator>& c, Predicate pred);    // C++20
-
-}  // std
-
-*/
-
-#include <__config>
-
-#include <memory>
-#include <limits>
-#include <initializer_list>
-#include <iterator>
-#include <algorithm>
-#include <type_traits>
-#include <version>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp, class _VoidPtr> struct __list_node;
-template <class _Tp, class _VoidPtr> struct __list_node_base;
-
-template <class _Tp, class _VoidPtr>
-struct __list_node_pointer_traits {
-  typedef typename __rebind_pointer<_VoidPtr, __list_node<_Tp, _VoidPtr> >::type
-        __node_pointer;
-  typedef typename __rebind_pointer<_VoidPtr, __list_node_base<_Tp, _VoidPtr> >::type
-        __base_pointer;
-
-#if defined(_LIBCPP_ABI_LIST_REMOVE_NODE_POINTER_UB)
-  typedef __base_pointer __link_pointer;
-#else
-  typedef typename conditional<
-          is_pointer<_VoidPtr>::value,
-          __base_pointer,
-          __node_pointer
-  >::type __link_pointer;
-#endif
-
-  typedef typename conditional<
-          is_same<__link_pointer, __node_pointer>::value,
-          __base_pointer,
-          __node_pointer
-  >::type __non_link_pointer;
-
-  static _LIBCPP_INLINE_VISIBILITY
-  __link_pointer __unsafe_link_pointer_cast(__link_pointer __p) {
-      return __p;
-  }
-
-  static _LIBCPP_INLINE_VISIBILITY
-  __link_pointer __unsafe_link_pointer_cast(__non_link_pointer __p) {
-      return static_cast<__link_pointer>(static_cast<_VoidPtr>(__p));
-  }
-
-};
-
-template <class _Tp, class _VoidPtr>
-struct __list_node_base
-{
-    typedef __list_node_pointer_traits<_Tp, _VoidPtr> _NodeTraits;
-    typedef typename _NodeTraits::__node_pointer __node_pointer;
-    typedef typename _NodeTraits::__base_pointer __base_pointer;
-    typedef typename _NodeTraits::__link_pointer __link_pointer;
-
-    __link_pointer __prev_;
-    __link_pointer __next_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_node_base() : __prev_(_NodeTraits::__unsafe_link_pointer_cast(__self())),
-                         __next_(_NodeTraits::__unsafe_link_pointer_cast(__self())) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __base_pointer __self() {
-        return pointer_traits<__base_pointer>::pointer_to(*this);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __node_pointer __as_node() {
-        return static_cast<__node_pointer>(__self());
-    }
-};
-
-template <class _Tp, class _VoidPtr>
-struct __list_node
-    : public __list_node_base<_Tp, _VoidPtr>
-{
-    _Tp __value_;
-
-    typedef __list_node_base<_Tp, _VoidPtr> __base;
-    typedef typename __base::__link_pointer __link_pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __link_pointer __as_link() {
-        return static_cast<__link_pointer>(__base::__self());
-    }
-};
-
-template <class _Tp, class _Alloc = allocator<_Tp> > class _LIBCPP_TEMPLATE_VIS list;
-template <class _Tp, class _Alloc> class __list_imp;
-template <class _Tp, class _VoidPtr> class _LIBCPP_TEMPLATE_VIS __list_const_iterator;
-
-template <class _Tp, class _VoidPtr>
-class _LIBCPP_TEMPLATE_VIS __list_iterator
-{
-    typedef __list_node_pointer_traits<_Tp, _VoidPtr> _NodeTraits;
-    typedef typename _NodeTraits::__link_pointer __link_pointer;
-
-    __link_pointer __ptr_;
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __list_iterator(__link_pointer __p, const void* __c) _NOEXCEPT
-        : __ptr_(__p)
-    {
-        __get_db()->__insert_ic(this, __c);
-    }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __list_iterator(__link_pointer __p) _NOEXCEPT : __ptr_(__p) {}
-#endif
-
-
-
-    template<class, class> friend class list;
-    template<class, class> friend class __list_imp;
-    template<class, class> friend class __list_const_iterator;
-public:
-    typedef bidirectional_iterator_tag       iterator_category;
-    typedef _Tp                              value_type;
-    typedef value_type&                      reference;
-    typedef typename __rebind_pointer<_VoidPtr, value_type>::type pointer;
-    typedef typename pointer_traits<pointer>::difference_type difference_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_iterator() _NOEXCEPT : __ptr_(nullptr)
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->__insert_i(this);
-#endif
-    }
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_iterator(const __list_iterator& __p)
-        : __ptr_(__p.__ptr_)
-    {
-        __get_db()->__iterator_copy(this, &__p);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__list_iterator()
-    {
-        __get_db()->__erase_i(this);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_iterator& operator=(const __list_iterator& __p)
-    {
-        if (this != &__p)
-        {
-            __get_db()->__iterator_copy(this, &__p);
-            __ptr_ = __p.__ptr_;
-        }
-        return *this;
-    }
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to dereference a non-dereferenceable list::iterator");
-#endif
-        return __ptr_->__as_node()->__value_;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to dereference a non-dereferenceable list::iterator");
-#endif
-        return pointer_traits<pointer>::pointer_to(__ptr_->__as_node()->__value_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_iterator& operator++()
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to increment non-incrementable list::iterator");
-#endif
-        __ptr_ = __ptr_->__next_;
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __list_iterator operator++(int) {__list_iterator __t(*this); ++(*this); return __t;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_iterator& operator--()
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
-                       "Attempted to decrement non-decrementable list::iterator");
-#endif
-        __ptr_ = __ptr_->__prev_;
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __list_iterator operator--(int) {__list_iterator __t(*this); --(*this); return __t;}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __list_iterator& __x, const __list_iterator& __y)
-    {
-        return __x.__ptr_ == __y.__ptr_;
-    }
-    friend _LIBCPP_INLINE_VISIBILITY
-     bool operator!=(const __list_iterator& __x, const __list_iterator& __y)
-        {return !(__x == __y);}
-};
-
-template <class _Tp, class _VoidPtr>
-class _LIBCPP_TEMPLATE_VIS __list_const_iterator
-{
-    typedef __list_node_pointer_traits<_Tp, _VoidPtr> _NodeTraits;
-    typedef typename _NodeTraits::__link_pointer __link_pointer;
-
-    __link_pointer __ptr_;
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __list_const_iterator(__link_pointer __p, const void* __c) _NOEXCEPT
-        : __ptr_(__p)
-    {
-        __get_db()->__insert_ic(this, __c);
-    }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __list_const_iterator(__link_pointer __p) _NOEXCEPT : __ptr_(__p) {}
-#endif
-
-    template<class, class> friend class list;
-    template<class, class> friend class __list_imp;
-public:
-    typedef bidirectional_iterator_tag       iterator_category;
-    typedef _Tp                              value_type;
-    typedef const value_type&                reference;
-    typedef typename __rebind_pointer<_VoidPtr, const value_type>::type pointer;
-    typedef typename pointer_traits<pointer>::difference_type difference_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_const_iterator() _NOEXCEPT : __ptr_(nullptr)
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->__insert_i(this);
-#endif
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __list_const_iterator(const __list_iterator<_Tp, _VoidPtr>& __p) _NOEXCEPT
-        : __ptr_(__p.__ptr_)
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->__iterator_copy(this, &__p);
-#endif
-    }
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_const_iterator(const __list_const_iterator& __p)
-        : __ptr_(__p.__ptr_)
-    {
-        __get_db()->__iterator_copy(this, &__p);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__list_const_iterator()
-    {
-        __get_db()->__erase_i(this);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_const_iterator& operator=(const __list_const_iterator& __p)
-    {
-        if (this != &__p)
-        {
-            __get_db()->__iterator_copy(this, &__p);
-            __ptr_ = __p.__ptr_;
-        }
-        return *this;
-    }
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to dereference a non-dereferenceable list::const_iterator");
-#endif
-        return __ptr_->__as_node()->__value_;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to dereference a non-dereferenceable list::const_iterator");
-#endif
-        return pointer_traits<pointer>::pointer_to(__ptr_->__as_node()->__value_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_const_iterator& operator++()
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(this),
-                       "Attempted to increment non-incrementable list::const_iterator");
-#endif
-        __ptr_ = __ptr_->__next_;
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __list_const_iterator operator++(int) {__list_const_iterator __t(*this); ++(*this); return __t;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_const_iterator& operator--()
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__decrementable(this),
-                       "Attempted to decrement non-decrementable list::const_iterator");
-#endif
-        __ptr_ = __ptr_->__prev_;
-        return *this;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    __list_const_iterator operator--(int) {__list_const_iterator __t(*this); --(*this); return __t;}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __list_const_iterator& __x, const __list_const_iterator& __y)
-    {
-        return __x.__ptr_ == __y.__ptr_;
-    }
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __list_const_iterator& __x, const __list_const_iterator& __y)
-        {return !(__x == __y);}
-};
-
-template <class _Tp, class _Alloc>
-class __list_imp
-{
-    __list_imp(const __list_imp&);
-    __list_imp& operator=(const __list_imp&);
-public:
-    typedef _Alloc                                                  allocator_type;
-    typedef allocator_traits<allocator_type>                        __alloc_traits;
-    typedef typename __alloc_traits::size_type                      size_type;
-protected:
-    typedef _Tp                                                     value_type;
-    typedef typename __alloc_traits::void_pointer                   __void_pointer;
-    typedef __list_iterator<value_type, __void_pointer>             iterator;
-    typedef __list_const_iterator<value_type, __void_pointer>       const_iterator;
-    typedef __list_node_base<value_type, __void_pointer>            __node_base;
-    typedef __list_node<value_type, __void_pointer>                 __node;
-    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
-    typedef allocator_traits<__node_allocator>                       __node_alloc_traits;
-    typedef typename __node_alloc_traits::pointer                    __node_pointer;
-    typedef typename __node_alloc_traits::pointer                    __node_const_pointer;
-    typedef __list_node_pointer_traits<value_type, __void_pointer> __node_pointer_traits;
-    typedef typename __node_pointer_traits::__link_pointer __link_pointer;
-    typedef __link_pointer __link_const_pointer;
-    typedef typename __alloc_traits::pointer                         pointer;
-    typedef typename __alloc_traits::const_pointer                   const_pointer;
-    typedef typename __alloc_traits::difference_type                 difference_type;
-
-    typedef typename __rebind_alloc_helper<__alloc_traits, __node_base>::type __node_base_allocator;
-    typedef typename allocator_traits<__node_base_allocator>::pointer __node_base_pointer;
-    static_assert((!is_same<allocator_type, __node_allocator>::value),
-                  "internal allocator type must differ from user-specified "
-                  "type; otherwise overload resolution breaks");
-
-    __node_base __end_;
-    __compressed_pair<size_type, __node_allocator> __size_alloc_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __link_pointer __end_as_link() const _NOEXCEPT {
-        return __node_pointer_traits::__unsafe_link_pointer_cast(
-                const_cast<__node_base&>(__end_).__self());
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-          size_type& __sz() _NOEXCEPT {return __size_alloc_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-    const size_type& __sz() const _NOEXCEPT
-        {return __size_alloc_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-          __node_allocator& __node_alloc() _NOEXCEPT
-          {return __size_alloc_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const __node_allocator& __node_alloc() const _NOEXCEPT
-        {return __size_alloc_.second();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type __node_alloc_max_size() const _NOEXCEPT {
-        return __node_alloc_traits::max_size(__node_alloc());
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    static void __unlink_nodes(__link_pointer __f, __link_pointer __l) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __list_imp()
-        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    __list_imp(const allocator_type& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    __list_imp(const __node_allocator& __a);
-#ifndef _LIBCPP_CXX03_LANG
-    __list_imp(__node_allocator&& __a) _NOEXCEPT;
-#endif
-    ~__list_imp();
-    void clear() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT {return __sz() == 0;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator begin() _NOEXCEPT
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        return iterator(__end_.__next_, this);
-#else
-        return iterator(__end_.__next_);
-#endif
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const  _NOEXCEPT
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        return const_iterator(__end_.__next_, this);
-#else
-        return const_iterator(__end_.__next_);
-#endif
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    iterator end() _NOEXCEPT
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        return iterator(__end_as_link(), this);
-#else
-        return iterator(__end_as_link());
-#endif
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        return const_iterator(__end_as_link(), this);
-#else
-        return const_iterator(__end_as_link());
-#endif
-    }
-
-    void swap(__list_imp& __c)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT_DEBUG;
-#else
-        _NOEXCEPT_DEBUG_(!__alloc_traits::propagate_on_container_swap::value ||
-                    __is_nothrow_swappable<allocator_type>::value);
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __list_imp& __c)
-        {__copy_assign_alloc(__c, integral_constant<bool,
-                      __node_alloc_traits::propagate_on_container_copy_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__list_imp& __c)
-        _NOEXCEPT_(
-            !__node_alloc_traits::propagate_on_container_move_assignment::value ||
-            is_nothrow_move_assignable<__node_allocator>::value)
-        {__move_assign_alloc(__c, integral_constant<bool,
-                      __node_alloc_traits::propagate_on_container_move_assignment::value>());}
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __list_imp& __c, true_type)
-        {
-            if (__node_alloc() != __c.__node_alloc())
-                clear();
-            __node_alloc() = __c.__node_alloc();
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __list_imp&, false_type)
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__list_imp& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
-        {
-            __node_alloc() = _VSTD::move(__c.__node_alloc());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__list_imp&, false_type)
-        _NOEXCEPT
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __invalidate_all_iterators() {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-      __get_db()->__invalidate_all(this);
-#endif
-    }
-};
-
-// Unlink nodes [__f, __l]
-template <class _Tp, class _Alloc>
-inline
-void
-__list_imp<_Tp, _Alloc>::__unlink_nodes(__link_pointer __f, __link_pointer __l)
-    _NOEXCEPT
-{
-    __f->__prev_->__next_ = __l->__next_;
-    __l->__next_->__prev_ = __f->__prev_;
-}
-
-template <class _Tp, class _Alloc>
-inline
-__list_imp<_Tp, _Alloc>::__list_imp()
-        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
-    : __size_alloc_(0)
-{
-}
-
-template <class _Tp, class _Alloc>
-inline
-__list_imp<_Tp, _Alloc>::__list_imp(const allocator_type& __a)
-    : __size_alloc_(0, __node_allocator(__a))
-{
-}
-
-template <class _Tp, class _Alloc>
-inline __list_imp<_Tp, _Alloc>::__list_imp(const __node_allocator& __a)
-    : __size_alloc_(0, __a) {}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp, class _Alloc>
-inline __list_imp<_Tp, _Alloc>::__list_imp(__node_allocator&& __a) _NOEXCEPT
-    : __size_alloc_(0, std::move(__a)) {}
-#endif
-
-template <class _Tp, class _Alloc>
-__list_imp<_Tp, _Alloc>::~__list_imp() {
-  clear();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__erase_c(this);
-#endif
-}
-
-template <class _Tp, class _Alloc>
-void
-__list_imp<_Tp, _Alloc>::clear() _NOEXCEPT
-{
-    if (!empty())
-    {
-        __node_allocator& __na = __node_alloc();
-        __link_pointer __f = __end_.__next_;
-        __link_pointer __l = __end_as_link();
-        __unlink_nodes(__f, __l->__prev_);
-        __sz() = 0;
-        while (__f != __l)
-        {
-            __node_pointer __np = __f->__as_node();
-            __f = __f->__next_;
-            __node_alloc_traits::destroy(__na, _VSTD::addressof(__np->__value_));
-            __node_alloc_traits::deallocate(__na, __np, 1);
-        }
-        __invalidate_all_iterators();
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-__list_imp<_Tp, _Alloc>::swap(__list_imp& __c)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT_DEBUG
-#else
-        _NOEXCEPT_DEBUG_(!__alloc_traits::propagate_on_container_swap::value ||
-                    __is_nothrow_swappable<allocator_type>::value)
-#endif
-{
-    _LIBCPP_ASSERT(__alloc_traits::propagate_on_container_swap::value ||
-                   this->__node_alloc() == __c.__node_alloc(),
-                   "list::swap: Either propagate_on_container_swap must be true"
-                   " or the allocators must compare equal");
-    using _VSTD::swap;
-    __swap_allocator(__node_alloc(), __c.__node_alloc());
-    swap(__sz(), __c.__sz());
-    swap(__end_, __c.__end_);
-    if (__sz() == 0)
-        __end_.__next_ = __end_.__prev_ = __end_as_link();
-    else
-        __end_.__prev_->__next_ = __end_.__next_->__prev_ = __end_as_link();
-    if (__c.__sz() == 0)
-        __c.__end_.__next_ = __c.__end_.__prev_ = __c.__end_as_link();
-    else
-        __c.__end_.__prev_->__next_ = __c.__end_.__next_->__prev_ = __c.__end_as_link();
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __libcpp_db* __db = __get_db();
-    __c_node* __cn1 = __db->__find_c_and_lock(this);
-    __c_node* __cn2 = __db->__find_c(&__c);
-    std::swap(__cn1->beg_, __cn2->beg_);
-    std::swap(__cn1->end_, __cn2->end_);
-    std::swap(__cn1->cap_, __cn2->cap_);
-    for (__i_node** __p = __cn1->end_; __p != __cn1->beg_;)
-    {
-        --__p;
-        const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_);
-        if (__i->__ptr_ == __c.__end_as_link())
-        {
-            __cn2->__add(*__p);
-            if (--__cn1->end_ != __p)
-                memmove(__p, __p+1, (__cn1->end_ - __p)*sizeof(__i_node*));
-        }
-        else
-            (*__p)->__c_ = __cn1;
-    }
-    for (__i_node** __p = __cn2->end_; __p != __cn2->beg_;)
-    {
-        --__p;
-        const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_);
-        if (__i->__ptr_ == __end_as_link())
-        {
-            __cn1->__add(*__p);
-            if (--__cn2->end_ != __p)
-                memmove(__p, __p+1, (__cn2->end_ - __p)*sizeof(__i_node*));
-        }
-        else
-            (*__p)->__c_ = __cn2;
-    }
-    __db->unlock();
-#endif
-}
-
-template <class _Tp, class _Alloc /*= allocator<_Tp>*/>
-class _LIBCPP_TEMPLATE_VIS list
-    : private __list_imp<_Tp, _Alloc>
-{
-    typedef __list_imp<_Tp, _Alloc> base;
-    typedef typename base::__node              __node;
-    typedef typename base::__node_allocator    __node_allocator;
-    typedef typename base::__node_pointer      __node_pointer;
-    typedef typename base::__node_alloc_traits __node_alloc_traits;
-    typedef typename base::__node_base         __node_base;
-    typedef typename base::__node_base_pointer __node_base_pointer;
-    typedef typename base::__link_pointer __link_pointer;
-
-public:
-    typedef _Tp                                      value_type;
-    typedef _Alloc                                   allocator_type;
-    static_assert((is_same<value_type, typename allocator_type::value_type>::value),
-                  "Invalid allocator::value_type");
-    typedef value_type&                              reference;
-    typedef const value_type&                        const_reference;
-    typedef typename base::pointer                   pointer;
-    typedef typename base::const_pointer             const_pointer;
-    typedef typename base::size_type                 size_type;
-    typedef typename base::difference_type           difference_type;
-    typedef typename base::iterator                  iterator;
-    typedef typename base::const_iterator            const_iterator;
-    typedef _VSTD::reverse_iterator<iterator>         reverse_iterator;
-    typedef _VSTD::reverse_iterator<const_iterator>   const_reverse_iterator;
-
-    _LIBCPP_INLINE_VISIBILITY
-    list()
-        _NOEXCEPT_(is_nothrow_default_constructible<__node_allocator>::value)
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->__insert_c(this);
-#endif
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    explicit list(const allocator_type& __a) : base(__a)
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->__insert_c(this);
-#endif
-    }
-    explicit list(size_type __n);
-#if _LIBCPP_STD_VER > 11
-    explicit list(size_type __n, const allocator_type& __a);
-#endif
-    list(size_type __n, const value_type& __x);
-    list(size_type __n, const value_type& __x, const allocator_type& __a);
-    template <class _InpIter>
-        list(_InpIter __f, _InpIter __l,
-             typename enable_if<__is_input_iterator<_InpIter>::value>::type* = 0);
-    template <class _InpIter>
-        list(_InpIter __f, _InpIter __l, const allocator_type& __a,
-             typename enable_if<__is_input_iterator<_InpIter>::value>::type* = 0);
-
-    list(const list& __c);
-    list(const list& __c, const allocator_type& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    list& operator=(const list& __c);
-#ifndef _LIBCPP_CXX03_LANG
-    list(initializer_list<value_type> __il);
-    list(initializer_list<value_type> __il, const allocator_type& __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    list(list&& __c)
-        _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    list(list&& __c, const allocator_type& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    list& operator=(list&& __c)
-        _NOEXCEPT_(
-            __node_alloc_traits::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<__node_allocator>::value);
-
-    _LIBCPP_INLINE_VISIBILITY
-    list& operator=(initializer_list<value_type> __il)
-        {assign(__il.begin(), __il.end()); return *this;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void assign(initializer_list<value_type> __il)
-        {assign(__il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    template <class _InpIter>
-        void assign(_InpIter __f, _InpIter __l,
-             typename enable_if<__is_input_iterator<_InpIter>::value>::type* = 0);
-    void assign(size_type __n, const value_type& __x);
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT     {return base::__sz();}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT         {return base::empty();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT
-        {
-            return std::min<size_type>(
-                base::__node_alloc_max_size(),
-                numeric_limits<difference_type >::max());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-          iterator begin() _NOEXCEPT        {return base::begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const _NOEXCEPT {return base::begin();}
-    _LIBCPP_INLINE_VISIBILITY
-          iterator end() _NOEXCEPT          {return base::end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const _NOEXCEPT {return base::end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT {return base::begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend()   const _NOEXCEPT {return base::end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rbegin() _NOEXCEPT
-            {return       reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin()  const _NOEXCEPT
-        {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rend() _NOEXCEPT
-            {return       reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend()    const _NOEXCEPT
-        {return const_reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT
-        {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend()   const _NOEXCEPT
-        {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference front()
-    {
-        _LIBCPP_ASSERT(!empty(), "list::front called on empty list");
-        return base::__end_.__next_->__as_node()->__value_;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference front() const
-    {
-        _LIBCPP_ASSERT(!empty(), "list::front called on empty list");
-        return base::__end_.__next_->__as_node()->__value_;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    reference back()
-    {
-        _LIBCPP_ASSERT(!empty(), "list::back called on empty list");
-        return base::__end_.__prev_->__as_node()->__value_;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference back() const
-    {
-        _LIBCPP_ASSERT(!empty(), "list::back called on empty list");
-        return base::__end_.__prev_->__as_node()->__value_;
-    }
-
-#ifndef _LIBCPP_CXX03_LANG
-    void push_front(value_type&& __x);
-    void push_back(value_type&& __x);
-
-    template <class... _Args>
-#if _LIBCPP_STD_VER > 14
-       reference emplace_front(_Args&&... __args);
-#else
-       void      emplace_front(_Args&&... __args);
-#endif
-    template <class... _Args>
-#if _LIBCPP_STD_VER > 14
-        reference emplace_back(_Args&&... __args);
-#else
-       void       emplace_back(_Args&&... __args);
-#endif
-    template <class... _Args>
-        iterator emplace(const_iterator __p, _Args&&... __args);
-
-    iterator insert(const_iterator __p, value_type&& __x);
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, initializer_list<value_type> __il)
-        {return insert(__p, __il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    void push_front(const value_type& __x);
-    void push_back(const value_type& __x);
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Arg>
-    _LIBCPP_INLINE_VISIBILITY
-    void __emplace_back(_Arg&& __arg) { emplace_back(_VSTD::forward<_Arg>(__arg)); }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    void __emplace_back(value_type const& __arg) { push_back(__arg); }
-#endif
-
-    iterator insert(const_iterator __p, const value_type& __x);
-    iterator insert(const_iterator __p, size_type __n, const value_type& __x);
-    template <class _InpIter>
-        iterator insert(const_iterator __p, _InpIter __f, _InpIter __l,
-             typename enable_if<__is_input_iterator<_InpIter>::value>::type* = 0);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(list& __c)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT_DEBUG
-#else
-        _NOEXCEPT_DEBUG_(!__node_alloc_traits::propagate_on_container_swap::value ||
-                   __is_nothrow_swappable<__node_allocator>::value)
-#endif
-        {base::swap(__c);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {base::clear();}
-
-    void pop_front();
-    void pop_back();
-
-    iterator erase(const_iterator __p);
-    iterator erase(const_iterator __f, const_iterator __l);
-
-    void resize(size_type __n);
-    void resize(size_type __n, const value_type& __x);
-
-    void splice(const_iterator __p, list& __c);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void splice(const_iterator __p, list&& __c) {splice(__p, __c);}
-    _LIBCPP_INLINE_VISIBILITY
-    void splice(const_iterator __p, list&& __c, const_iterator __i)
-        {splice(__p, __c, __i);}
-    _LIBCPP_INLINE_VISIBILITY
-    void splice(const_iterator __p, list&& __c, const_iterator __f, const_iterator __l)
-        {splice(__p, __c, __f, __l);}
-#endif
-    void splice(const_iterator __p, list& __c, const_iterator __i);
-    void splice(const_iterator __p, list& __c, const_iterator __f, const_iterator __l);
-
-    void remove(const value_type& __x);
-    template <class _Pred> void remove_if(_Pred __pred);
-    _LIBCPP_INLINE_VISIBILITY
-    void unique();
-    template <class _BinaryPred>
-        void unique(_BinaryPred __binary_pred);
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(list& __c);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(list&& __c) {merge(__c);}
-
-    template <class _Comp>
-    _LIBCPP_INLINE_VISIBILITY
-        void merge(list&& __c, _Comp __comp) {merge(__c, __comp);}
-#endif
-    template <class _Comp>
-        void merge(list& __c, _Comp __comp);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void sort();
-    template <class _Comp>
-        _LIBCPP_INLINE_VISIBILITY
-        void sort(_Comp __comp);
-
-    void reverse() _NOEXCEPT;
-
-    bool __invariants() const;
-
-    typedef __allocator_destructor<__node_allocator> __node_destructor;
-    typedef unique_ptr<__node, __node_destructor> __hold_pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hold_pointer __allocate_node(__node_allocator& __na) {
-      __node_pointer __p = __node_alloc_traits::allocate(__na, 1);
-      __p->__prev_ = nullptr;
-      return __hold_pointer(__p, __node_destructor(__na, 1));
-    }
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    bool __dereferenceable(const const_iterator* __i) const;
-    bool __decrementable(const const_iterator* __i) const;
-    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
-    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    static void __link_nodes  (__link_pointer __p, __link_pointer __f, __link_pointer __l);
-    _LIBCPP_INLINE_VISIBILITY
-    void __link_nodes_at_front(__link_pointer __f, __link_pointer __l);
-    _LIBCPP_INLINE_VISIBILITY
-    void __link_nodes_at_back (__link_pointer __f, __link_pointer __l);
-    iterator __iterator(size_type __n);
-    template <class _Comp>
-        static iterator __sort(iterator __f1, iterator __e2, size_type __n, _Comp& __comp);
-
-    void __move_assign(list& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value);
-    void __move_assign(list& __c, false_type);
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class _InputIterator,
-         class _Alloc = typename std::allocator<typename iterator_traits<_InputIterator>::value_type>,
-         class = typename enable_if<__is_allocator<_Alloc>::value, void>::type
-         >
-list(_InputIterator, _InputIterator)
-  -> list<typename iterator_traits<_InputIterator>::value_type, _Alloc>;
-
-template<class _InputIterator,
-         class _Alloc,
-         class = typename enable_if<__is_allocator<_Alloc>::value, void>::type
-         >
-list(_InputIterator, _InputIterator, _Alloc)
-  -> list<typename iterator_traits<_InputIterator>::value_type, _Alloc>;
-#endif
-
-// Link in nodes [__f, __l] just prior to __p
-template <class _Tp, class _Alloc>
-inline
-void
-list<_Tp, _Alloc>::__link_nodes(__link_pointer __p, __link_pointer __f, __link_pointer __l)
-{
-    __p->__prev_->__next_ = __f;
-    __f->__prev_ = __p->__prev_;
-    __p->__prev_ = __l;
-    __l->__next_ = __p;
-}
-
-// Link in nodes [__f, __l] at the front of the list
-template <class _Tp, class _Alloc>
-inline
-void
-list<_Tp, _Alloc>::__link_nodes_at_front(__link_pointer __f, __link_pointer __l)
-{
-    __f->__prev_ = base::__end_as_link();
-    __l->__next_ = base::__end_.__next_;
-    __l->__next_->__prev_ = __l;
-    base::__end_.__next_ = __f;
-}
-
-// Link in nodes [__f, __l] at the back of the list
-template <class _Tp, class _Alloc>
-inline
-void
-list<_Tp, _Alloc>::__link_nodes_at_back(__link_pointer __f, __link_pointer __l)
-{
-    __l->__next_ = base::__end_as_link();
-    __f->__prev_ = base::__end_.__prev_;
-    __f->__prev_->__next_ = __f;
-    base::__end_.__prev_ = __l;
-}
-
-
-template <class _Tp, class _Alloc>
-inline
-typename list<_Tp, _Alloc>::iterator
-list<_Tp, _Alloc>::__iterator(size_type __n)
-{
-    return __n <= base::__sz() / 2 ? _VSTD::next(begin(), __n)
-                                   : _VSTD::prev(end(), base::__sz() - __n);
-}
-
-template <class _Tp, class _Alloc>
-list<_Tp, _Alloc>::list(size_type __n)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (; __n > 0; --__n)
-#ifndef _LIBCPP_CXX03_LANG
-        emplace_back();
-#else
-        push_back(value_type());
-#endif
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp, class _Alloc>
-list<_Tp, _Alloc>::list(size_type __n, const allocator_type& __a) : base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (; __n > 0; --__n)
-        emplace_back();
-}
-#endif
-
-template <class _Tp, class _Alloc>
-list<_Tp, _Alloc>::list(size_type __n, const value_type& __x)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (; __n > 0; --__n)
-        push_back(__x);
-}
-
-template <class _Tp, class _Alloc>
-list<_Tp, _Alloc>::list(size_type __n, const value_type& __x, const allocator_type& __a)
-    : base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (; __n > 0; --__n)
-        push_back(__x);
-}
-
-template <class _Tp, class _Alloc>
-template <class _InpIter>
-list<_Tp, _Alloc>::list(_InpIter __f, _InpIter __l,
-                        typename enable_if<__is_input_iterator<_InpIter>::value>::type*)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (; __f != __l; ++__f)
-        __emplace_back(*__f);
-}
-
-template <class _Tp, class _Alloc>
-template <class _InpIter>
-list<_Tp, _Alloc>::list(_InpIter __f, _InpIter __l, const allocator_type& __a,
-                        typename enable_if<__is_input_iterator<_InpIter>::value>::type*)
-    : base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (; __f != __l; ++__f)
-        __emplace_back(*__f);
-}
-
-template <class _Tp, class _Alloc>
-list<_Tp, _Alloc>::list(const list& __c)
-    : base(__node_alloc_traits::select_on_container_copy_construction(
-          __c.__node_alloc())) {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (const_iterator __i = __c.begin(), __e = __c.end(); __i != __e; ++__i)
-        push_back(*__i);
-}
-
-template <class _Tp, class _Alloc>
-list<_Tp, _Alloc>::list(const list& __c, const allocator_type& __a)
-    : base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (const_iterator __i = __c.begin(), __e = __c.end(); __i != __e; ++__i)
-        push_back(*__i);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-list<_Tp, _Alloc>::list(initializer_list<value_type> __il, const allocator_type& __a)
-    : base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (typename initializer_list<value_type>::const_iterator __i = __il.begin(),
-            __e = __il.end(); __i != __e; ++__i)
-        push_back(*__i);
-}
-
-template <class _Tp, class _Alloc>
-list<_Tp, _Alloc>::list(initializer_list<value_type> __il)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (typename initializer_list<value_type>::const_iterator __i = __il.begin(),
-            __e = __il.end(); __i != __e; ++__i)
-        push_back(*__i);
-}
-
-template <class _Tp, class _Alloc>
-inline list<_Tp, _Alloc>::list(list&& __c)
-    _NOEXCEPT_(is_nothrow_move_constructible<__node_allocator>::value)
-    : base(_VSTD::move(__c.__node_alloc())) {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    splice(end(), __c);
-}
-
-template <class _Tp, class _Alloc>
-inline
-list<_Tp, _Alloc>::list(list&& __c, const allocator_type& __a)
-    : base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__a == __c.get_allocator())
-        splice(end(), __c);
-    else
-    {
-        typedef move_iterator<iterator> _Ip;
-        assign(_Ip(__c.begin()), _Ip(__c.end()));
-    }
-}
-
-template <class _Tp, class _Alloc>
-inline
-list<_Tp, _Alloc>&
-list<_Tp, _Alloc>::operator=(list&& __c)
-        _NOEXCEPT_(
-            __node_alloc_traits::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<__node_allocator>::value)
-{
-    __move_assign(__c, integral_constant<bool,
-          __node_alloc_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::__move_assign(list& __c, false_type)
-{
-    if (base::__node_alloc() != __c.__node_alloc())
-    {
-        typedef move_iterator<iterator> _Ip;
-        assign(_Ip(__c.begin()), _Ip(__c.end()));
-    }
-    else
-        __move_assign(__c, true_type());
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::__move_assign(list& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<__node_allocator>::value)
-{
-    clear();
-    base::__move_assign_alloc(__c);
-    splice(end(), __c);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-inline
-list<_Tp, _Alloc>&
-list<_Tp, _Alloc>::operator=(const list& __c)
-{
-    if (this != &__c)
-    {
-        base::__copy_assign_alloc(__c);
-        assign(__c.begin(), __c.end());
-    }
-    return *this;
-}
-
-template <class _Tp, class _Alloc>
-template <class _InpIter>
-void
-list<_Tp, _Alloc>::assign(_InpIter __f, _InpIter __l,
-                          typename enable_if<__is_input_iterator<_InpIter>::value>::type*)
-{
-    iterator __i = begin();
-    iterator __e = end();
-    for (; __f != __l && __i != __e; ++__f, ++__i)
-        *__i = *__f;
-    if (__i == __e)
-        insert(__e, __f, __l);
-    else
-        erase(__i, __e);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-      __get_db()->__invalidate_all(this);
-#endif
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::assign(size_type __n, const value_type& __x)
-{
-    iterator __i = begin();
-    iterator __e = end();
-    for (; __n > 0 && __i != __e; --__n, ++__i)
-        *__i = __x;
-    if (__i == __e)
-        insert(__e, __n, __x);
-    else
-        erase(__i, __e);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-      __get_db()->__invalidate_all(this);
-#endif
-}
-
-template <class _Tp, class _Alloc>
-inline
-_Alloc
-list<_Tp, _Alloc>::get_allocator() const _NOEXCEPT
-{
-    return allocator_type(base::__node_alloc());
-}
-
-template <class _Tp, class _Alloc>
-typename list<_Tp, _Alloc>::iterator
-list<_Tp, _Alloc>::insert(const_iterator __p, const value_type& __x)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "list::insert(iterator, x) called with an iterator not"
-        " referring to this list");
-#endif
-    __node_allocator& __na = base::__node_alloc();
-    __hold_pointer __hold = __allocate_node(__na);
-    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
-    __link_nodes(__p.__ptr_, __hold->__as_link(), __hold->__as_link());
-    ++base::__sz();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator(__hold.release()->__as_link(), this);
-#else
-    return iterator(__hold.release()->__as_link());
-#endif
-}
-
-template <class _Tp, class _Alloc>
-typename list<_Tp, _Alloc>::iterator
-list<_Tp, _Alloc>::insert(const_iterator __p, size_type __n, const value_type& __x)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "list::insert(iterator, n, x) called with an iterator not"
-        " referring to this list");
-    iterator __r(__p.__ptr_, this);
-#else
-    iterator __r(__p.__ptr_);
-#endif
-    if (__n > 0)
-    {
-        size_type __ds = 0;
-        __node_allocator& __na = base::__node_alloc();
-        __hold_pointer __hold = __allocate_node(__na);
-        __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
-        ++__ds;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __r = iterator(__hold->__as_link(), this);
-#else
-        __r = iterator(__hold->__as_link());
-#endif
-        __hold.release();
-        iterator __e = __r;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (--__n; __n != 0; --__n, ++__e, ++__ds)
-            {
-                __hold.reset(__node_alloc_traits::allocate(__na, 1));
-                __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
-                __e.__ptr_->__next_ = __hold->__as_link();
-                __hold->__prev_ = __e.__ptr_;
-                __hold.release();
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (true)
-            {
-                __node_alloc_traits::destroy(__na, _VSTD::addressof(*__e));
-                __link_pointer __prev = __e.__ptr_->__prev_;
-                __node_alloc_traits::deallocate(__na, __e.__ptr_->__as_node(), 1);
-                if (__prev == 0)
-                    break;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-                __e = iterator(__prev, this);
-#else
-                __e = iterator(__prev);
-#endif
-            }
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __link_nodes(__p.__ptr_, __r.__ptr_, __e.__ptr_);
-        base::__sz() += __ds;
-    }
-    return __r;
-}
-
-template <class _Tp, class _Alloc>
-template <class _InpIter>
-typename list<_Tp, _Alloc>::iterator
-list<_Tp, _Alloc>::insert(const_iterator __p, _InpIter __f, _InpIter __l,
-             typename enable_if<__is_input_iterator<_InpIter>::value>::type*)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "list::insert(iterator, range) called with an iterator not"
-        " referring to this list");
-    iterator __r(__p.__ptr_, this);
-#else
-    iterator __r(__p.__ptr_);
-#endif
-    if (__f != __l)
-    {
-        size_type __ds = 0;
-        __node_allocator& __na = base::__node_alloc();
-        __hold_pointer __hold = __allocate_node(__na);
-        __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), *__f);
-        ++__ds;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __r = iterator(__hold.get()->__as_link(), this);
-#else
-        __r = iterator(__hold.get()->__as_link());
-#endif
-        __hold.release();
-        iterator __e = __r;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (++__f; __f != __l; ++__f, (void) ++__e, (void) ++__ds)
-            {
-                __hold.reset(__node_alloc_traits::allocate(__na, 1));
-                __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), *__f);
-                __e.__ptr_->__next_ = __hold.get()->__as_link();
-                __hold->__prev_ = __e.__ptr_;
-                __hold.release();
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (true)
-            {
-                __node_alloc_traits::destroy(__na, _VSTD::addressof(*__e));
-                __link_pointer __prev = __e.__ptr_->__prev_;
-                __node_alloc_traits::deallocate(__na, __e.__ptr_->__as_node(), 1);
-                if (__prev == 0)
-                    break;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-                __e = iterator(__prev, this);
-#else
-                __e = iterator(__prev);
-#endif
-            }
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __link_nodes(__p.__ptr_, __r.__ptr_, __e.__ptr_);
-        base::__sz() += __ds;
-    }
-    return __r;
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::push_front(const value_type& __x)
-{
-    __node_allocator& __na = base::__node_alloc();
-    __hold_pointer __hold = __allocate_node(__na);
-    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
-    __link_pointer __nl = __hold->__as_link();
-    __link_nodes_at_front(__nl, __nl);
-    ++base::__sz();
-    __hold.release();
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::push_back(const value_type& __x)
-{
-    __node_allocator& __na = base::__node_alloc();
-    __hold_pointer __hold = __allocate_node(__na);
-    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
-    __link_nodes_at_back(__hold.get()->__as_link(), __hold.get()->__as_link());
-    ++base::__sz();
-    __hold.release();
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::push_front(value_type&& __x)
-{
-    __node_allocator& __na = base::__node_alloc();
-    __hold_pointer __hold = __allocate_node(__na);
-    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::move(__x));
-    __link_nodes_at_front(__hold.get()->__as_link(), __hold.get()->__as_link());
-    ++base::__sz();
-    __hold.release();
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::push_back(value_type&& __x)
-{
-    __node_allocator& __na = base::__node_alloc();
-    __hold_pointer __hold = __allocate_node(__na);
-    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::move(__x));
-    __link_nodes_at_back(__hold.get()->__as_link(), __hold.get()->__as_link());
-    ++base::__sz();
-    __hold.release();
-}
-
-template <class _Tp, class _Alloc>
-template <class... _Args>
-#if _LIBCPP_STD_VER > 14
-typename list<_Tp, _Alloc>::reference
-#else
-void
-#endif
-list<_Tp, _Alloc>::emplace_front(_Args&&... __args)
-{
-    __node_allocator& __na = base::__node_alloc();
-    __hold_pointer __hold = __allocate_node(__na);
-    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::forward<_Args>(__args)...);
-    __link_nodes_at_front(__hold.get()->__as_link(), __hold.get()->__as_link());
-    ++base::__sz();
-#if _LIBCPP_STD_VER > 14
-    return __hold.release()->__value_;
-#else
-    __hold.release();
-#endif
-}
-
-template <class _Tp, class _Alloc>
-template <class... _Args>
-#if _LIBCPP_STD_VER > 14
-typename list<_Tp, _Alloc>::reference
-#else
-void
-#endif
-list<_Tp, _Alloc>::emplace_back(_Args&&... __args)
-{
-    __node_allocator& __na = base::__node_alloc();
-    __hold_pointer __hold = __allocate_node(__na);
-    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::forward<_Args>(__args)...);
-    __link_pointer __nl = __hold->__as_link();
-    __link_nodes_at_back(__nl, __nl);
-    ++base::__sz();
-#if _LIBCPP_STD_VER > 14
-    return __hold.release()->__value_;
-#else
-    __hold.release();
-#endif
-}
-
-template <class _Tp, class _Alloc>
-template <class... _Args>
-typename list<_Tp, _Alloc>::iterator
-list<_Tp, _Alloc>::emplace(const_iterator __p, _Args&&... __args)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "list::emplace(iterator, args...) called with an iterator not"
-        " referring to this list");
-#endif
-    __node_allocator& __na = base::__node_alloc();
-    __hold_pointer __hold = __allocate_node(__na);
-    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::forward<_Args>(__args)...);
-    __link_pointer __nl = __hold.get()->__as_link();
-    __link_nodes(__p.__ptr_, __nl, __nl);
-    ++base::__sz();
-    __hold.release();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator(__nl, this);
-#else
-    return iterator(__nl);
-#endif
-}
-
-template <class _Tp, class _Alloc>
-typename list<_Tp, _Alloc>::iterator
-list<_Tp, _Alloc>::insert(const_iterator __p, value_type&& __x)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "list::insert(iterator, x) called with an iterator not"
-        " referring to this list");
-#endif
-    __node_allocator& __na = base::__node_alloc();
-    __hold_pointer __hold = __allocate_node(__na);
-    __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), _VSTD::move(__x));
-    __link_pointer __nl = __hold->__as_link();
-    __link_nodes(__p.__ptr_, __nl, __nl);
-    ++base::__sz();
-    __hold.release();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator(__nl, this);
-#else
-    return iterator(__nl);
-#endif
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::pop_front()
-{
-    _LIBCPP_ASSERT(!empty(), "list::pop_front() called with empty list");
-    __node_allocator& __na = base::__node_alloc();
-    __link_pointer __n = base::__end_.__next_;
-    base::__unlink_nodes(__n, __n);
-    --base::__sz();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __c_node* __c = __get_db()->__find_c_and_lock(this);
-    for (__i_node** __p = __c->end_; __p != __c->beg_; )
-    {
-        --__p;
-        iterator* __i = static_cast<iterator*>((*__p)->__i_);
-        if (__i->__ptr_ == __n)
-        {
-            (*__p)->__c_ = nullptr;
-            if (--__c->end_ != __p)
-                memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
-        }
-    }
-    __get_db()->unlock();
-#endif
-    __node_pointer __np = __n->__as_node();
-    __node_alloc_traits::destroy(__na, _VSTD::addressof(__np->__value_));
-    __node_alloc_traits::deallocate(__na, __np, 1);
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::pop_back()
-{
-    _LIBCPP_ASSERT(!empty(), "list::pop_back() called with empty list");
-    __node_allocator& __na = base::__node_alloc();
-    __link_pointer __n = base::__end_.__prev_;
-    base::__unlink_nodes(__n, __n);
-    --base::__sz();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __c_node* __c = __get_db()->__find_c_and_lock(this);
-    for (__i_node** __p = __c->end_; __p != __c->beg_; )
-    {
-        --__p;
-        iterator* __i = static_cast<iterator*>((*__p)->__i_);
-        if (__i->__ptr_ == __n)
-        {
-            (*__p)->__c_ = nullptr;
-            if (--__c->end_ != __p)
-                memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
-        }
-    }
-    __get_db()->unlock();
-#endif
-    __node_pointer __np = __n->__as_node();
-    __node_alloc_traits::destroy(__na, _VSTD::addressof(__np->__value_));
-    __node_alloc_traits::deallocate(__na, __np, 1);
-}
-
-template <class _Tp, class _Alloc>
-typename list<_Tp, _Alloc>::iterator
-list<_Tp, _Alloc>::erase(const_iterator __p)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "list::erase(iterator) called with an iterator not"
-        " referring to this list");
-#endif
-    _LIBCPP_ASSERT(__p != end(),
-        "list::erase(iterator) called with a non-dereferenceable iterator");
-    __node_allocator& __na = base::__node_alloc();
-    __link_pointer __n = __p.__ptr_;
-    __link_pointer __r = __n->__next_;
-    base::__unlink_nodes(__n, __n);
-    --base::__sz();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __c_node* __c = __get_db()->__find_c_and_lock(this);
-    for (__i_node** __ip = __c->end_; __ip != __c->beg_; )
-    {
-        --__ip;
-        iterator* __i = static_cast<iterator*>((*__ip)->__i_);
-        if (__i->__ptr_ == __n)
-        {
-            (*__ip)->__c_ = nullptr;
-            if (--__c->end_ != __ip)
-                memmove(__ip, __ip+1, (__c->end_ - __ip)*sizeof(__i_node*));
-        }
-    }
-    __get_db()->unlock();
-#endif
-    __node_pointer __np = __n->__as_node();
-    __node_alloc_traits::destroy(__na, _VSTD::addressof(__np->__value_));
-    __node_alloc_traits::deallocate(__na, __np, 1);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator(__r, this);
-#else
-    return iterator(__r);
-#endif
-}
-
-template <class _Tp, class _Alloc>
-typename list<_Tp, _Alloc>::iterator
-list<_Tp, _Alloc>::erase(const_iterator __f, const_iterator __l)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__f) == this,
-        "list::erase(iterator, iterator) called with an iterator not"
-        " referring to this list");
-   _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__l) == this,
-        "list::erase(iterator, iterator) called with an iterator not"
-        " referring to this list");
-#endif
-    if (__f != __l)
-    {
-        __node_allocator& __na = base::__node_alloc();
-        base::__unlink_nodes(__f.__ptr_, __l.__ptr_->__prev_);
-        while (__f != __l)
-        {
-            __link_pointer __n = __f.__ptr_;
-            ++__f;
-            --base::__sz();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-            __c_node* __c = __get_db()->__find_c_and_lock(this);
-            for (__i_node** __p = __c->end_; __p != __c->beg_; )
-            {
-                --__p;
-                iterator* __i = static_cast<iterator*>((*__p)->__i_);
-                if (__i->__ptr_ == __n)
-                {
-                    (*__p)->__c_ = nullptr;
-                    if (--__c->end_ != __p)
-                        memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
-                }
-            }
-            __get_db()->unlock();
-#endif
-            __node_pointer __np = __n->__as_node();
-            __node_alloc_traits::destroy(__na, _VSTD::addressof(__np->__value_));
-            __node_alloc_traits::deallocate(__na, __np, 1);
-        }
-    }
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator(__l.__ptr_, this);
-#else
-    return iterator(__l.__ptr_);
-#endif
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::resize(size_type __n)
-{
-    if (__n < base::__sz())
-        erase(__iterator(__n), end());
-    else if (__n > base::__sz())
-    {
-        __n -= base::__sz();
-        size_type __ds = 0;
-        __node_allocator& __na = base::__node_alloc();
-        __hold_pointer __hold = __allocate_node(__na);
-        __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_));
-        ++__ds;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        iterator __r = iterator(__hold.release()->__as_link(), this);
-#else
-        iterator __r = iterator(__hold.release()->__as_link());
-#endif
-        iterator __e = __r;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (--__n; __n != 0; --__n, ++__e, ++__ds)
-            {
-                __hold.reset(__node_alloc_traits::allocate(__na, 1));
-                __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_));
-                __e.__ptr_->__next_ = __hold.get()->__as_link();
-                __hold->__prev_ = __e.__ptr_;
-                __hold.release();
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (true)
-            {
-                __node_alloc_traits::destroy(__na, _VSTD::addressof(*__e));
-                __link_pointer __prev = __e.__ptr_->__prev_;
-                __node_alloc_traits::deallocate(__na, __e.__ptr_->__as_node(), 1);
-                if (__prev == 0)
-                    break;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-                __e = iterator(__prev, this);
-#else
-                __e = iterator(__prev);
-#endif
-            }
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __link_nodes_at_back(__r.__ptr_, __e.__ptr_);
-        base::__sz() += __ds;
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::resize(size_type __n, const value_type& __x)
-{
-    if (__n < base::__sz())
-        erase(__iterator(__n), end());
-    else if (__n > base::__sz())
-    {
-        __n -= base::__sz();
-        size_type __ds = 0;
-        __node_allocator& __na = base::__node_alloc();
-        __hold_pointer __hold = __allocate_node(__na);
-        __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
-        ++__ds;
-        __link_pointer __nl = __hold.release()->__as_link();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        iterator __r = iterator(__nl, this);
-#else
-        iterator __r = iterator(__nl);
-#endif
-        iterator __e = __r;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (--__n; __n != 0; --__n, ++__e, ++__ds)
-            {
-                __hold.reset(__node_alloc_traits::allocate(__na, 1));
-                __node_alloc_traits::construct(__na, _VSTD::addressof(__hold->__value_), __x);
-                __e.__ptr_->__next_ = __hold.get()->__as_link();
-                __hold->__prev_ = __e.__ptr_;
-                __hold.release();
-            }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            while (true)
-            {
-                __node_alloc_traits::destroy(__na, _VSTD::addressof(*__e));
-                __link_pointer __prev = __e.__ptr_->__prev_;
-                __node_alloc_traits::deallocate(__na, __e.__ptr_->__as_node(), 1);
-                if (__prev == 0)
-                    break;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-                __e = iterator(__prev, this);
-#else
-                __e = iterator(__prev);
-#endif
-            }
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        __link_nodes(base::__end_as_link(), __r.__ptr_, __e.__ptr_);
-        base::__sz() += __ds;
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::splice(const_iterator __p, list& __c)
-{
-    _LIBCPP_ASSERT(this != &__c,
-                   "list::splice(iterator, list) called with this == &list");
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "list::splice(iterator, list) called with an iterator not"
-        " referring to this list");
-#endif
-    if (!__c.empty())
-    {
-        __link_pointer __f = __c.__end_.__next_;
-        __link_pointer __l = __c.__end_.__prev_;
-        base::__unlink_nodes(__f, __l);
-        __link_nodes(__p.__ptr_, __f, __l);
-        base::__sz() += __c.__sz();
-        __c.__sz() = 0;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __libcpp_db* __db = __get_db();
-        __c_node* __cn1 = __db->__find_c_and_lock(this);
-        __c_node* __cn2 = __db->__find_c(&__c);
-        for (__i_node** __ip = __cn2->end_; __ip != __cn2->beg_;)
-        {
-            --__ip;
-            iterator* __i = static_cast<iterator*>((*__ip)->__i_);
-            if (__i->__ptr_ != __c.__end_as_link())
-            {
-                __cn1->__add(*__ip);
-                (*__ip)->__c_ = __cn1;
-                if (--__cn2->end_ != __ip)
-                    memmove(__ip, __ip+1, (__cn2->end_ - __ip)*sizeof(__i_node*));
-            }
-        }
-        __db->unlock();
-#endif
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::splice(const_iterator __p, list& __c, const_iterator __i)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "list::splice(iterator, list, iterator) called with first iterator not"
-        " referring to this list");
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__i) == &__c,
-        "list::splice(iterator, list, iterator) called with second iterator not"
-        " referring to list argument");
-    _LIBCPP_ASSERT(__get_const_db()->__dereferenceable(&__i),
-        "list::splice(iterator, list, iterator) called with second iterator not"
-        " derefereceable");
-#endif
-    if (__p.__ptr_ != __i.__ptr_ && __p.__ptr_ != __i.__ptr_->__next_)
-    {
-        __link_pointer __f = __i.__ptr_;
-        base::__unlink_nodes(__f, __f);
-        __link_nodes(__p.__ptr_, __f, __f);
-        --__c.__sz();
-        ++base::__sz();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __libcpp_db* __db = __get_db();
-        __c_node* __cn1 = __db->__find_c_and_lock(this);
-        __c_node* __cn2 = __db->__find_c(&__c);
-        for (__i_node** __ip = __cn2->end_; __ip != __cn2->beg_;)
-        {
-            --__ip;
-            iterator* __j = static_cast<iterator*>((*__ip)->__i_);
-            if (__j->__ptr_ == __f)
-            {
-                __cn1->__add(*__ip);
-                (*__ip)->__c_ = __cn1;
-                if (--__cn2->end_ != __ip)
-                    memmove(__ip, __ip+1, (__cn2->end_ - __ip)*sizeof(__i_node*));
-            }
-        }
-        __db->unlock();
-#endif
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::splice(const_iterator __p, list& __c, const_iterator __f, const_iterator __l)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-        "list::splice(iterator, list, iterator, iterator) called with first iterator not"
-        " referring to this list");
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__f) == &__c,
-        "list::splice(iterator, list, iterator, iterator) called with second iterator not"
-        " referring to list argument");
-    if (this == &__c)
-    {
-        for (const_iterator __i = __f; __i != __l; ++__i)
-            _LIBCPP_ASSERT(__i != __p,
-                           "list::splice(iterator, list, iterator, iterator)"
-                           " called with the first iterator within the range"
-                           " of the second and third iterators");
-    }
-#endif
-    if (__f != __l)
-    {
-        __link_pointer __first = __f.__ptr_;
-        --__l;
-        __link_pointer __last = __l.__ptr_;
-        if (this != &__c)
-        {
-            size_type __s = _VSTD::distance(__f, __l) + 1;
-            __c.__sz() -= __s;
-            base::__sz() += __s;
-        }
-        base::__unlink_nodes(__first, __last);
-        __link_nodes(__p.__ptr_, __first, __last);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __libcpp_db* __db = __get_db();
-        __c_node* __cn1 = __db->__find_c_and_lock(this);
-        __c_node* __cn2 = __db->__find_c(&__c);
-        for (__i_node** __ip = __cn2->end_; __ip != __cn2->beg_;)
-        {
-            --__ip;
-            iterator* __j = static_cast<iterator*>((*__ip)->__i_);
-            for (__link_pointer __k = __f.__ptr_;
-                                          __k != __l.__ptr_; __k = __k->__next_)
-            {
-                if (__j->__ptr_ == __k)
-                {
-                    __cn1->__add(*__ip);
-                    (*__ip)->__c_ = __cn1;
-                    if (--__cn2->end_ != __ip)
-                        memmove(__ip, __ip+1, (__cn2->end_ - __ip)*sizeof(__i_node*));
-                }
-            }
-        }
-        __db->unlock();
-#endif
-    }
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::remove(const value_type& __x)
-{
-    list<_Tp, _Alloc> __deleted_nodes(get_allocator()); // collect the nodes we're removing
-    for (const_iterator __i = begin(), __e = end(); __i != __e;)
-    {
-        if (*__i == __x)
-        {
-            const_iterator __j = _VSTD::next(__i);
-            for (; __j != __e && *__j == __x; ++__j)
-                ;
-            __deleted_nodes.splice(__deleted_nodes.end(), *this, __i, __j);
-            __i = __j;
-            if (__i != __e)
-                ++__i;
-        }
-        else
-            ++__i;
-    }
-}
-
-template <class _Tp, class _Alloc>
-template <class _Pred>
-void
-list<_Tp, _Alloc>::remove_if(_Pred __pred)
-{
-    for (iterator __i = begin(), __e = end(); __i != __e;)
-    {
-        if (__pred(*__i))
-        {
-            iterator __j = _VSTD::next(__i);
-            for (; __j != __e && __pred(*__j); ++__j)
-                ;
-            __i = erase(__i, __j);
-            if (__i != __e)
-                ++__i;
-        }
-        else
-            ++__i;
-    }
-}
-
-template <class _Tp, class _Alloc>
-inline
-void
-list<_Tp, _Alloc>::unique()
-{
-    unique(__equal_to<value_type>());
-}
-
-template <class _Tp, class _Alloc>
-template <class _BinaryPred>
-void
-list<_Tp, _Alloc>::unique(_BinaryPred __binary_pred)
-{
-    for (iterator __i = begin(), __e = end(); __i != __e;)
-    {
-        iterator __j = _VSTD::next(__i);
-        for (; __j != __e && __binary_pred(*__i, *__j); ++__j)
-            ;
-        if (++__i != __j)
-            __i = erase(__i, __j);
-    }
-}
-
-template <class _Tp, class _Alloc>
-inline
-void
-list<_Tp, _Alloc>::merge(list& __c)
-{
-    merge(__c, __less<value_type>());
-}
-
-template <class _Tp, class _Alloc>
-template <class _Comp>
-void
-list<_Tp, _Alloc>::merge(list& __c, _Comp __comp)
-{
-    if (this != _VSTD::addressof(__c))
-    {
-        iterator __f1 = begin();
-        iterator __e1 = end();
-        iterator __f2 = __c.begin();
-        iterator __e2 = __c.end();
-        while (__f1 != __e1 && __f2 != __e2)
-        {
-            if (__comp(*__f2, *__f1))
-            {
-                size_type __ds = 1;
-                iterator __m2 = _VSTD::next(__f2);
-                for (; __m2 != __e2 && __comp(*__m2, *__f1); ++__m2, ++__ds)
-                    ;
-                base::__sz() += __ds;
-                __c.__sz() -= __ds;
-                __link_pointer __f = __f2.__ptr_;
-                __link_pointer __l = __m2.__ptr_->__prev_;
-                __f2 = __m2;
-                base::__unlink_nodes(__f, __l);
-                __m2 = _VSTD::next(__f1);
-                __link_nodes(__f1.__ptr_, __f, __l);
-                __f1 = __m2;
-            }
-            else
-                ++__f1;
-        }
-        splice(__e1, __c);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __libcpp_db* __db = __get_db();
-        __c_node* __cn1 = __db->__find_c_and_lock(this);
-        __c_node* __cn2 = __db->__find_c(&__c);
-        for (__i_node** __p = __cn2->end_; __p != __cn2->beg_;)
-        {
-            --__p;
-            iterator* __i = static_cast<iterator*>((*__p)->__i_);
-            if (__i->__ptr_ != __c.__end_as_link())
-            {
-                __cn1->__add(*__p);
-                (*__p)->__c_ = __cn1;
-                if (--__cn2->end_ != __p)
-                    memmove(__p, __p+1, (__cn2->end_ - __p)*sizeof(__i_node*));
-            }
-        }
-        __db->unlock();
-#endif
-    }
-}
-
-template <class _Tp, class _Alloc>
-inline
-void
-list<_Tp, _Alloc>::sort()
-{
-    sort(__less<value_type>());
-}
-
-template <class _Tp, class _Alloc>
-template <class _Comp>
-inline
-void
-list<_Tp, _Alloc>::sort(_Comp __comp)
-{
-    __sort(begin(), end(), base::__sz(), __comp);
-}
-
-template <class _Tp, class _Alloc>
-template <class _Comp>
-typename list<_Tp, _Alloc>::iterator
-list<_Tp, _Alloc>::__sort(iterator __f1, iterator __e2, size_type __n, _Comp& __comp)
-{
-    switch (__n)
-    {
-    case 0:
-    case 1:
-        return __f1;
-    case 2:
-        if (__comp(*--__e2, *__f1))
-        {
-            __link_pointer __f = __e2.__ptr_;
-            base::__unlink_nodes(__f, __f);
-            __link_nodes(__f1.__ptr_, __f, __f);
-            return __e2;
-        }
-        return __f1;
-    }
-    size_type __n2 = __n / 2;
-    iterator __e1 = _VSTD::next(__f1, __n2);
-    iterator  __r = __f1 = __sort(__f1, __e1, __n2, __comp);
-    iterator __f2 = __e1 = __sort(__e1, __e2, __n - __n2, __comp);
-    if (__comp(*__f2, *__f1))
-    {
-        iterator __m2 = _VSTD::next(__f2);
-        for (; __m2 != __e2 && __comp(*__m2, *__f1); ++__m2)
-            ;
-        __link_pointer __f = __f2.__ptr_;
-        __link_pointer __l = __m2.__ptr_->__prev_;
-        __r = __f2;
-        __e1 = __f2 = __m2;
-        base::__unlink_nodes(__f, __l);
-        __m2 = _VSTD::next(__f1);
-        __link_nodes(__f1.__ptr_, __f, __l);
-        __f1 = __m2;
-    }
-    else
-        ++__f1;
-    while (__f1 != __e1 && __f2 != __e2)
-    {
-        if (__comp(*__f2, *__f1))
-        {
-            iterator __m2 = _VSTD::next(__f2);
-            for (; __m2 != __e2 && __comp(*__m2, *__f1); ++__m2)
-                ;
-            __link_pointer __f = __f2.__ptr_;
-            __link_pointer __l = __m2.__ptr_->__prev_;
-            if (__e1 == __f2)
-                __e1 = __m2;
-            __f2 = __m2;
-            base::__unlink_nodes(__f, __l);
-            __m2 = _VSTD::next(__f1);
-            __link_nodes(__f1.__ptr_, __f, __l);
-            __f1 = __m2;
-        }
-        else
-            ++__f1;
-    }
-    return __r;
-}
-
-template <class _Tp, class _Alloc>
-void
-list<_Tp, _Alloc>::reverse() _NOEXCEPT
-{
-    if (base::__sz() > 1)
-    {
-        iterator __e = end();
-        for (iterator __i = begin(); __i.__ptr_ != __e.__ptr_;)
-        {
-            _VSTD::swap(__i.__ptr_->__prev_, __i.__ptr_->__next_);
-            __i.__ptr_ = __i.__ptr_->__prev_;
-        }
-        _VSTD::swap(__e.__ptr_->__prev_, __e.__ptr_->__next_);
-    }
-}
-
-template <class _Tp, class _Alloc>
-bool
-list<_Tp, _Alloc>::__invariants() const
-{
-    return size() == _VSTD::distance(begin(), end());
-}
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-template <class _Tp, class _Alloc>
-bool
-list<_Tp, _Alloc>::__dereferenceable(const const_iterator* __i) const
-{
-    return __i->__ptr_ != this->__end_as_link();
-}
-
-template <class _Tp, class _Alloc>
-bool
-list<_Tp, _Alloc>::__decrementable(const const_iterator* __i) const
-{
-    return !empty() &&  __i->__ptr_ != base::__end_.__next_;
-}
-
-template <class _Tp, class _Alloc>
-bool
-list<_Tp, _Alloc>::__addable(const const_iterator*, ptrdiff_t) const
-{
-    return false;
-}
-
-template <class _Tp, class _Alloc>
-bool
-list<_Tp, _Alloc>::__subscriptable(const const_iterator*, ptrdiff_t) const
-{
-    return false;
-}
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
-{
-    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
-{
-    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const list<_Tp, _Alloc>& __x, const list<_Tp, _Alloc>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(list<_Tp, _Alloc>& __x, list<_Tp, _Alloc>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Tp, class _Allocator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(list<_Tp, _Allocator>& __c, _Predicate __pred)
-{ __c.remove_if(__pred); }
-
-template <class _Tp, class _Allocator, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase(list<_Tp, _Allocator>& __c, const _Up& __v)
-{ _VSTD::erase_if(__c, [&](auto& __elem) { return __elem == __v; }); }
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_LIST
diff --git a/lib/libcxx/include/locale b/lib/libcxx/include/locale
deleted file mode 100644
index aa6a9ab916e..00000000000
--- a/lib/libcxx/include/locale
+++ /dev/null
@@ -1,4360 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- locale ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_LOCALE
-#define _LIBCPP_LOCALE
-
-/*
-    locale synopsis
-
-namespace std
-{
-
-class locale
-{
-public:
-    // types:
-    class facet;
-    class id;
-
-    typedef int category;
-    static const category // values assigned here are for exposition only
-        none     = 0x000,
-        collate  = 0x010,
-        ctype    = 0x020,
-        monetary = 0x040,
-        numeric  = 0x080,
-        time     = 0x100,
-        messages = 0x200,
-        all = collate | ctype | monetary | numeric | time | messages;
-
-    // construct/copy/destroy:
-    locale() noexcept;
-    locale(const locale& other) noexcept;
-    explicit locale(const char* std_name);
-    explicit locale(const string& std_name);
-    locale(const locale& other, const char* std_name, category);
-    locale(const locale& other, const string& std_name, category);
-    template <class Facet> locale(const locale& other, Facet* f);
-    locale(const locale& other, const locale& one, category);
-
-    ~locale(); // not virtual
-
-    const locale& operator=(const locale& other) noexcept;
-
-    template <class Facet> locale combine(const locale& other) const;
-
-    // locale operations:
-    basic_string<char> name() const;
-    bool operator==(const locale& other) const;
-    bool operator!=(const locale& other) const;
-    template <class charT, class Traits, class Allocator>
-      bool operator()(const basic_string<charT,Traits,Allocator>& s1,
-                      const basic_string<charT,Traits,Allocator>& s2) const;
-
-    // global locale objects:
-    static locale global(const locale&);
-    static const locale& classic();
-};
-
-template <class Facet> const Facet& use_facet(const locale&);
-template <class Facet> bool has_facet(const locale&) noexcept;
-
-// 22.3.3, convenience interfaces:
-template <class charT> bool isspace (charT c, const locale& loc);
-template <class charT> bool isprint (charT c, const locale& loc);
-template <class charT> bool iscntrl (charT c, const locale& loc);
-template <class charT> bool isupper (charT c, const locale& loc);
-template <class charT> bool islower (charT c, const locale& loc);
-template <class charT> bool isalpha (charT c, const locale& loc);
-template <class charT> bool isdigit (charT c, const locale& loc);
-template <class charT> bool ispunct (charT c, const locale& loc);
-template <class charT> bool isxdigit(charT c, const locale& loc);
-template <class charT> bool isalnum (charT c, const locale& loc);
-template <class charT> bool isgraph (charT c, const locale& loc);
-template <class charT> charT toupper(charT c, const locale& loc);
-template <class charT> charT tolower(charT c, const locale& loc);
-
-template<class Codecvt, class Elem = wchar_t,
-         class Wide_alloc = allocator<Elem>,
-         class Byte_alloc = allocator<char>>
-class wstring_convert
-{
-public:
-    typedef basic_string<char, char_traits<char>, Byte_alloc> byte_string;
-    typedef basic_string<Elem, char_traits<Elem>, Wide_alloc> wide_string;
-    typedef typename Codecvt::state_type                      state_type;
-    typedef typename wide_string::traits_type::int_type       int_type;
-
-    explicit wstring_convert(Codecvt* pcvt = new Codecvt);          // explicit in C++14
-    wstring_convert(Codecvt* pcvt, state_type state);
-    explicit wstring_convert(const byte_string& byte_err,           // explicit in C++14
-                    const wide_string& wide_err = wide_string());
-    wstring_convert(const wstring_convert&) = delete;               // C++14
-    wstring_convert & operator=(const wstring_convert &) = delete;  // C++14
-    ~wstring_convert();
-
-    wide_string from_bytes(char byte);
-    wide_string from_bytes(const char* ptr);
-    wide_string from_bytes(const byte_string& str);
-    wide_string from_bytes(const char* first, const char* last);
-
-    byte_string to_bytes(Elem wchar);
-    byte_string to_bytes(const Elem* wptr);
-    byte_string to_bytes(const wide_string& wstr);
-    byte_string to_bytes(const Elem* first, const Elem* last);
-
-    size_t converted() const; // noexcept in C++14
-    state_type state() const;
-};
-
-template <class Codecvt, class Elem = wchar_t, class Tr = char_traits<Elem>>
-class wbuffer_convert
-    : public basic_streambuf<Elem, Tr>
-{
-public:
-    typedef typename Tr::state_type state_type;
-
-    explicit wbuffer_convert(streambuf* bytebuf = 0, Codecvt* pcvt = new Codecvt,
-                    state_type state = state_type());       // explicit in C++14
-    wbuffer_convert(const wbuffer_convert&) = delete;               // C++14
-    wbuffer_convert & operator=(const wbuffer_convert &) = delete;  // C++14
-    ~wbuffer_convert();                                             // C++14
-    
-    streambuf* rdbuf() const;
-    streambuf* rdbuf(streambuf* bytebuf);
-
-    state_type state() const;
-};
-
-// 22.4.1 and 22.4.1.3, ctype:
-class ctype_base;
-template <class charT> class ctype;
-template <> class ctype<char>; // specialization
-template <class charT> class ctype_byname;
-template <> class ctype_byname<char>; // specialization
-
-class codecvt_base;
-template <class internT, class externT, class stateT> class codecvt;
-template <class internT, class externT, class stateT> class codecvt_byname;
-
-// 22.4.2 and 22.4.3, numeric:
-template <class charT, class InputIterator> class num_get;
-template <class charT, class OutputIterator> class num_put;
-template <class charT> class numpunct;
-template <class charT> class numpunct_byname;
-
-// 22.4.4, col lation:
-template <class charT> class collate;
-template <class charT> class collate_byname;
-
-// 22.4.5, date and time:
-class time_base;
-template <class charT, class InputIterator> class time_get;
-template <class charT, class InputIterator> class time_get_byname;
-template <class charT, class OutputIterator> class time_put;
-template <class charT, class OutputIterator> class time_put_byname;
-
-// 22.4.6, money:
-class money_base;
-template <class charT, class InputIterator> class money_get;
-template <class charT, class OutputIterator> class money_put;
-template <class charT, bool Intl> class moneypunct;
-template <class charT, bool Intl> class moneypunct_byname;
-
-// 22.4.7, message retrieval:
-class messages_base;
-template <class charT> class messages;
-template <class charT> class messages_byname;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__locale>
-#include <__debug>
-#include <algorithm>
-#include <memory>
-#include <ios>
-#include <streambuf>
-#include <iterator>
-#include <limits>
-#include <version>
-#ifndef __APPLE__
-#include <cstdarg>
-#endif
-#include <cstdlib>
-#include <ctime>
-#include <cstdio>
-#ifdef _LIBCPP_HAS_CATOPEN
-#include <nl_types.h>
-#endif
-
-#ifdef __APPLE__
-#include <Availability.h>
-#endif
-
-#ifdef _LIBCPP_LOCALE__L_EXTENSIONS
-#include <__bsd_locale_defaults.h>
-#else
-#include <__bsd_locale_fallbacks.h>
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if defined(__APPLE__) || defined(__FreeBSD__)
-#  define _LIBCPP_GET_C_LOCALE 0
-#elif defined(__CloudABI__) || defined(__NetBSD__)
-#  define _LIBCPP_GET_C_LOCALE LC_C_LOCALE
-#else
-#  define _LIBCPP_GET_C_LOCALE __cloc()
-   // Get the C locale object
-   _LIBCPP_FUNC_VIS locale_t __cloc();
-#define __cloc_defined
-#endif
-
-// __scan_keyword
-// Scans [__b, __e) until a match is found in the basic_strings range
-//  [__kb, __ke) or until it can be shown that there is no match in [__kb, __ke).
-//  __b will be incremented (visibly), consuming CharT until a match is found
-//  or proved to not exist.  A keyword may be "", in which will match anything.
-//  If one keyword is a prefix of another, and the next CharT in the input
-//  might match another keyword, the algorithm will attempt to find the longest
-//  matching keyword.  If the longer matching keyword ends up not matching, then
-//  no keyword match is found.  If no keyword match is found, __ke is returned
-//  and failbit is set in __err.
-//  Else an iterator pointing to the matching keyword is found.  If more than
-//  one keyword matches, an iterator to the first matching keyword is returned.
-//  If on exit __b == __e, eofbit is set in __err.  If __case_sensitive is false,
-//  __ct is used to force to lower case before comparing characters.
-//  Examples:
-//  Keywords:  "a", "abb"
-//  If the input is "a", the first keyword matches and eofbit is set.
-//  If the input is "abc", no match is found and "ab" are consumed.
-template <class _InputIterator, class _ForwardIterator, class _Ctype>
-_LIBCPP_HIDDEN
-_ForwardIterator
-__scan_keyword(_InputIterator& __b, _InputIterator __e,
-               _ForwardIterator __kb, _ForwardIterator __ke,
-               const _Ctype& __ct, ios_base::iostate& __err,
-               bool __case_sensitive = true)
-{
-    typedef typename iterator_traits<_InputIterator>::value_type _CharT;
-    size_t __nkw = static_cast<size_t>(_VSTD::distance(__kb, __ke));
-    const unsigned char __doesnt_match = '\0';
-    const unsigned char __might_match = '\1';
-    const unsigned char __does_match = '\2';
-    unsigned char __statbuf[100];
-    unsigned char* __status = __statbuf;
-    unique_ptr<unsigned char, void(*)(void*)> __stat_hold(0, free);
-    if (__nkw > sizeof(__statbuf))
-    {
-        __status = (unsigned char*)malloc(__nkw);
-        if (__status == 0)
-            __throw_bad_alloc();
-        __stat_hold.reset(__status);
-    }
-    size_t __n_might_match = __nkw;  // At this point, any keyword might match
-    size_t __n_does_match = 0;       // but none of them definitely do
-    // Initialize all statuses to __might_match, except for "" keywords are __does_match
-    unsigned char* __st = __status;
-    for (_ForwardIterator __ky = __kb; __ky != __ke; ++__ky, (void) ++__st)
-    {
-        if (!__ky->empty())
-            *__st = __might_match;
-        else
-        {
-            *__st = __does_match;
-            --__n_might_match;
-            ++__n_does_match;
-        }
-    }
-    // While there might be a match, test keywords against the next CharT
-    for (size_t __indx = 0; __b != __e && __n_might_match > 0; ++__indx)
-    {
-        // Peek at the next CharT but don't consume it
-        _CharT __c = *__b;
-        if (!__case_sensitive)
-            __c = __ct.toupper(__c);
-        bool __consume = false;
-        // For each keyword which might match, see if the __indx character is __c
-        // If a match if found, consume __c
-        // If a match is found, and that is the last character in the keyword,
-        //    then that keyword matches.
-        // If the keyword doesn't match this character, then change the keyword
-        //    to doesn't match
-        __st = __status;
-        for (_ForwardIterator __ky = __kb; __ky != __ke; ++__ky, (void) ++__st)
-        {
-            if (*__st == __might_match)
-            {
-                _CharT __kc = (*__ky)[__indx];
-                if (!__case_sensitive)
-                    __kc = __ct.toupper(__kc);
-                if (__c == __kc)
-                {
-                    __consume = true;
-                    if (__ky->size() == __indx+1)
-                    {
-                        *__st = __does_match;
-                        --__n_might_match;
-                        ++__n_does_match;
-                    }
-                }
-                else
-                {
-                    *__st = __doesnt_match;
-                    --__n_might_match;
-                }
-            }
-        }
-        // consume if we matched a character
-        if (__consume)
-        {
-            ++__b;
-            // If we consumed a character and there might be a matched keyword that
-            //   was marked matched on a previous iteration, then such keywords
-            //   which are now marked as not matching.
-            if (__n_might_match + __n_does_match > 1)
-            {
-                __st = __status;
-                for (_ForwardIterator __ky = __kb; __ky != __ke; ++__ky, (void) ++__st)
-                {
-                    if (*__st == __does_match && __ky->size() != __indx+1)
-                    {
-                        *__st = __doesnt_match;
-                        --__n_does_match;
-                    }
-                }
-            }
-        }
-    }
-    // We've exited the loop because we hit eof and/or we have no more "might matches".
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-    // Return the first matching result
-    for (__st = __status; __kb != __ke; ++__kb, (void) ++__st)
-        if (*__st == __does_match)
-            break;
-    if (__kb == __ke)
-        __err |= ios_base::failbit;
-    return __kb;
-}
-
-struct _LIBCPP_TYPE_VIS __num_get_base
-{
-    static const int __num_get_buf_sz = 40;
-
-    static int __get_base(ios_base&);
-    static const char __src[33];
-};
-
-_LIBCPP_FUNC_VIS
-void __check_grouping(const string& __grouping, unsigned* __g, unsigned* __g_end,
-                      ios_base::iostate& __err);
-
-template <class _CharT>
-struct __num_get
-    : protected __num_get_base
-{
-    static string __stage2_float_prep(ios_base& __iob, _CharT* __atoms, _CharT& __decimal_point,
-                                      _CharT& __thousands_sep);
-
-    static int __stage2_float_loop(_CharT __ct, bool& __in_units, char& __exp,
-                                   char* __a, char*& __a_end,
-                                   _CharT __decimal_point, _CharT __thousands_sep,
-                                   const string& __grouping, unsigned* __g,
-                                   unsigned*& __g_end, unsigned& __dc, _CharT* __atoms);
-#ifndef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
-    static string __stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep);
-    static int __stage2_int_loop(_CharT __ct, int __base, char* __a, char*& __a_end,
-                  unsigned& __dc, _CharT __thousands_sep, const string& __grouping,
-                  unsigned* __g, unsigned*& __g_end, _CharT* __atoms);
-
-#else
-    static string __stage2_int_prep(ios_base& __iob, _CharT& __thousands_sep)
-    {
-        locale __loc = __iob.getloc();
-        const numpunct<_CharT>& __np = use_facet<numpunct<_CharT> >(__loc);
-        __thousands_sep = __np.thousands_sep();
-        return __np.grouping();
-    }
-
-    const _CharT* __do_widen(ios_base& __iob, _CharT* __atoms) const
-    {
-      return __do_widen_p(__iob, __atoms);
-    }
-
-
-    static int __stage2_int_loop(_CharT __ct, int __base, char* __a, char*& __a_end,
-                  unsigned& __dc, _CharT __thousands_sep, const string& __grouping,
-                  unsigned* __g, unsigned*& __g_end, const _CharT* __atoms);
-private:
-    template<typename T>
-    const T* __do_widen_p(ios_base& __iob, T* __atoms) const
-    {
-      locale __loc = __iob.getloc();
-      use_facet<ctype<T> >(__loc).widen(__src, __src + 26, __atoms);
-      return __atoms;
-    }
-
-    const char* __do_widen_p(ios_base& __iob, char* __atoms) const
-    {
-      (void)__iob;
-      (void)__atoms;
-      return __src;
-    }
-#endif
-};
-
-#ifndef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
-template <class _CharT>
-string
-__num_get<_CharT>::__stage2_int_prep(ios_base& __iob, _CharT* __atoms, _CharT& __thousands_sep)
-{
-    locale __loc = __iob.getloc();
-    use_facet<ctype<_CharT> >(__loc).widen(__src, __src + 26, __atoms);
-    const numpunct<_CharT>& __np = use_facet<numpunct<_CharT> >(__loc);
-    __thousands_sep = __np.thousands_sep();
-    return __np.grouping();
-}
-#endif
-
-template <class _CharT>
-string
-__num_get<_CharT>::__stage2_float_prep(ios_base& __iob, _CharT* __atoms, _CharT& __decimal_point,
-                    _CharT& __thousands_sep)
-{
-    locale __loc = __iob.getloc();
-    use_facet<ctype<_CharT> >(__loc).widen(__src, __src + 32, __atoms);
-    const numpunct<_CharT>& __np = use_facet<numpunct<_CharT> >(__loc);
-    __decimal_point = __np.decimal_point();
-    __thousands_sep = __np.thousands_sep();
-    return __np.grouping();
-}
-
-template <class _CharT>
-int
-#ifndef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
-__num_get<_CharT>::__stage2_int_loop(_CharT __ct, int __base, char* __a, char*& __a_end,
-                  unsigned& __dc, _CharT __thousands_sep, const string& __grouping,
-                  unsigned* __g, unsigned*& __g_end, _CharT* __atoms)
-#else
-__num_get<_CharT>::__stage2_int_loop(_CharT __ct, int __base, char* __a, char*& __a_end,
-                  unsigned& __dc, _CharT __thousands_sep, const string& __grouping,
-                  unsigned* __g, unsigned*& __g_end, const _CharT* __atoms)
-
-#endif
-{
-    if (__a_end == __a && (__ct == __atoms[24] || __ct == __atoms[25]))
-    {
-        *__a_end++ = __ct == __atoms[24] ? '+' : '-';
-        __dc = 0;
-        return 0;
-    }
-    if (__grouping.size() != 0 && __ct == __thousands_sep)
-    {
-        if (__g_end-__g < __num_get_buf_sz)
-        {
-            *__g_end++ = __dc;
-            __dc = 0;
-        }
-        return 0;
-    }
-    ptrdiff_t __f = find(__atoms, __atoms + 26, __ct) - __atoms;
-    if (__f >= 24)
-        return -1;
-    switch (__base)
-    {
-    case 8:
-    case 10:
-        if (__f >= __base)
-            return -1;
-        break;
-    case 16:
-        if (__f < 22)
-            break;
-        if (__a_end != __a && __a_end - __a <= 2 && __a_end[-1] == '0')
-        {
-            __dc = 0;
-            *__a_end++ = __src[__f];
-            return 0;
-        }
-        return -1;
-    }
-    *__a_end++ = __src[__f];
-    ++__dc;
-    return 0;
-}
-
-template <class _CharT>
-int
-__num_get<_CharT>::__stage2_float_loop(_CharT __ct, bool& __in_units, char& __exp, char* __a, char*& __a_end,
-                    _CharT __decimal_point, _CharT __thousands_sep, const string& __grouping,
-                    unsigned* __g, unsigned*& __g_end, unsigned& __dc, _CharT* __atoms)
-{
-    if (__ct == __decimal_point)
-    {
-        if (!__in_units)
-            return -1;
-        __in_units = false;
-        *__a_end++ = '.';
-        if (__grouping.size() != 0 && __g_end-__g < __num_get_buf_sz)
-            *__g_end++ = __dc;
-        return 0;
-    }
-    if (__ct == __thousands_sep && __grouping.size() != 0)
-    {
-        if (!__in_units)
-            return -1;
-        if (__g_end-__g < __num_get_buf_sz)
-        {
-            *__g_end++ = __dc;
-            __dc = 0;
-        }
-        return 0;
-    }
-    ptrdiff_t __f = find(__atoms, __atoms + 32, __ct) - __atoms;
-    if (__f >= 32)
-        return -1;
-    char __x = __src[__f];
-    if (__x == '-' || __x == '+')
-    {
-        if (__a_end == __a || (__a_end[-1] & 0x5F) == (__exp & 0x7F))
-        {
-            *__a_end++ = __x;
-            return 0;
-        }
-        return -1;
-    }
-    if (__x == 'x' || __x == 'X')
-        __exp = 'P';
-    else if ((__x & 0x5F) == __exp)
-    {
-        __exp |= 0x80;
-        if (__in_units)
-        {
-            __in_units = false;
-            if (__grouping.size() != 0 && __g_end-__g < __num_get_buf_sz)
-                *__g_end++ = __dc;
-        }
-    }
-    *__a_end++ = __x;
-    if (__f >= 22)
-        return 0;
-    ++__dc;
-    return 0;
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(struct _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __num_get<char>)
-_LIBCPP_EXTERN_TEMPLATE2(struct _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __num_get<wchar_t>)
-
-template <class _CharT, class _InputIterator = istreambuf_iterator<_CharT> >
-class _LIBCPP_TEMPLATE_VIS num_get
-    : public locale::facet,
-      private __num_get<_CharT>
-{
-public:
-    typedef _CharT char_type;
-    typedef _InputIterator iter_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit num_get(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, bool& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, long& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, long long& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, unsigned short& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, unsigned int& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, unsigned long& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, unsigned long long& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, float& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, double& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, long double& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, void*& __v) const
-    {
-        return do_get(__b, __e, __iob, __err, __v);
-    }
-
-    static locale::id id;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~num_get() {}
-
-    template <class _Fp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    iter_type __do_get_floating_point
-                            (iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, _Fp& __v) const;
-
-    template <class _Signed>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    iter_type __do_get_signed
-                            (iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, _Signed& __v) const;
-
-    template <class _Unsigned>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    iter_type __do_get_unsigned
-                            (iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, _Unsigned& __v) const;
-
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, bool& __v) const;
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, long& __v) const
-    { return this->__do_get_signed ( __b, __e, __iob, __err, __v ); }
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, long long& __v) const
-    { return this->__do_get_signed ( __b, __e, __iob, __err, __v ); }
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, unsigned short& __v) const
-    { return this->__do_get_unsigned ( __b, __e, __iob, __err, __v ); }
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, unsigned int& __v) const
-    { return this->__do_get_unsigned ( __b, __e, __iob, __err, __v ); }
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, unsigned long& __v) const
-    { return this->__do_get_unsigned ( __b, __e, __iob, __err, __v ); }
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, unsigned long long& __v) const
-    { return this->__do_get_unsigned ( __b, __e, __iob, __err, __v ); }
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, float& __v) const
-    { return this->__do_get_floating_point ( __b, __e, __iob, __err, __v ); }
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, double& __v) const
-    { return this->__do_get_floating_point ( __b, __e, __iob, __err, __v ); }
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, long double& __v) const
-    { return this->__do_get_floating_point ( __b, __e, __iob, __err, __v ); }
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, void*& __v) const;
-};
-
-template <class _CharT, class _InputIterator>
-locale::id
-num_get<_CharT, _InputIterator>::id;
-
-template <class _Tp>
-_LIBCPP_HIDDEN _Tp
-__num_get_signed_integral(const char* __a, const char* __a_end,
-                          ios_base::iostate& __err, int __base)
-{
-    if (__a != __a_end)
-    {
-        typename remove_reference<decltype(errno)>::type __save_errno = errno;
-        errno = 0;
-        char *__p2;
-        long long __ll = strtoll_l(__a, &__p2, __base, _LIBCPP_GET_C_LOCALE);
-        typename remove_reference<decltype(errno)>::type __current_errno = errno;
-        if (__current_errno == 0)
-            errno = __save_errno;
-        if (__p2 != __a_end)
-        {
-            __err = ios_base::failbit;
-            return 0;
-        }
-        else if (__current_errno == ERANGE         ||
-                 __ll < numeric_limits<_Tp>::min() ||
-                 numeric_limits<_Tp>::max() < __ll)
-        {
-            __err = ios_base::failbit;
-            if (__ll > 0)
-                return numeric_limits<_Tp>::max();
-            else
-                return numeric_limits<_Tp>::min();
-        }
-        return static_cast<_Tp>(__ll);
-    }
-    __err = ios_base::failbit;
-    return 0;
-}
-
-template <class _Tp>
-_LIBCPP_HIDDEN _Tp
-__num_get_unsigned_integral(const char* __a, const char* __a_end,
-                            ios_base::iostate& __err, int __base)
-{
-    if (__a != __a_end)
-    {
-        const bool __negate = *__a == '-';
-        if (__negate && ++__a == __a_end) {
-          __err = ios_base::failbit;
-          return 0;
-        }
-        typename remove_reference<decltype(errno)>::type __save_errno = errno;
-        errno = 0;
-        char *__p2;
-        unsigned long long __ll = strtoull_l(__a, &__p2, __base, _LIBCPP_GET_C_LOCALE);
-        typename remove_reference<decltype(errno)>::type __current_errno = errno;
-        if (__current_errno == 0)
-            errno = __save_errno;
-        if (__p2 != __a_end)
-        {
-            __err = ios_base::failbit;
-            return 0;
-        }
-        else if (__current_errno == ERANGE || numeric_limits<_Tp>::max() < __ll)
-        {
-            __err = ios_base::failbit;
-            return numeric_limits<_Tp>::max();
-        }
-        _Tp __res = static_cast<_Tp>(__ll);
-        if (__negate) __res = -__res;
-        return __res;
-    }
-    __err = ios_base::failbit;
-    return 0;
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp __do_strtod(const char* __a, char** __p2);
-
-template <>
-inline _LIBCPP_INLINE_VISIBILITY
-float __do_strtod<float>(const char* __a, char** __p2) {
-    return strtof_l(__a, __p2, _LIBCPP_GET_C_LOCALE);
-}
-
-template <>
-inline _LIBCPP_INLINE_VISIBILITY
-double __do_strtod<double>(const char* __a, char** __p2) {
-    return strtod_l(__a, __p2, _LIBCPP_GET_C_LOCALE);
-}
-
-template <>
-inline _LIBCPP_INLINE_VISIBILITY
-long double __do_strtod<long double>(const char* __a, char** __p2) {
-    return strtold_l(__a, __p2, _LIBCPP_GET_C_LOCALE);
-}
-
-template <class _Tp>
-_LIBCPP_HIDDEN
-_Tp
-__num_get_float(const char* __a, const char* __a_end, ios_base::iostate& __err)
-{
-    if (__a != __a_end)
-    {
-        typename remove_reference<decltype(errno)>::type __save_errno = errno;
-        errno = 0;
-        char *__p2;
-        _Tp __ld = __do_strtod<_Tp>(__a, &__p2);
-        typename remove_reference<decltype(errno)>::type __current_errno = errno;
-        if (__current_errno == 0)
-            errno = __save_errno;
-        if (__p2 != __a_end)
-        {
-            __err = ios_base::failbit;
-            return 0;
-        }
-        else if (__current_errno == ERANGE)
-            __err = ios_base::failbit;
-        return __ld;
-    }
-    __err = ios_base::failbit;
-    return 0;
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-num_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
-                                        ios_base& __iob,
-                                        ios_base::iostate& __err,
-                                        bool& __v) const
-{
-    if ((__iob.flags() & ios_base::boolalpha) == 0)
-    {
-        long __lv = -1;
-        __b = do_get(__b, __e, __iob, __err, __lv);
-        switch (__lv)
-        {
-        case 0:
-            __v = false;
-            break;
-        case 1:
-            __v = true;
-            break;
-        default:
-            __v = true;
-            __err = ios_base::failbit;
-            break;
-        }
-        return __b;
-    }
-    const ctype<_CharT>& __ct = use_facet<ctype<_CharT> >(__iob.getloc());
-    const numpunct<_CharT>& __np = use_facet<numpunct<_CharT> >(__iob.getloc());
-    typedef typename numpunct<_CharT>::string_type string_type;
-    const string_type __names[2] = {__np.truename(), __np.falsename()};
-    const string_type* __i = __scan_keyword(__b, __e, __names, __names+2,
-                                            __ct, __err);
-    __v = __i == __names;
-    return __b;
-}
-
-// signed
-
-template <class _CharT, class _InputIterator>
-template <class _Signed>
-_InputIterator
-num_get<_CharT, _InputIterator>::__do_get_signed(iter_type __b, iter_type __e,
-                                        ios_base& __iob,
-                                        ios_base::iostate& __err,
-                                        _Signed& __v) const
-{
-    // Stage 1
-    int __base = this->__get_base(__iob);
-    // Stage 2
-    char_type __thousands_sep;
-    const int __atoms_size = 26;
-#ifdef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
-    char_type __atoms1[__atoms_size];
-    const char_type *__atoms = this->__do_widen(__iob, __atoms1);
-    string __grouping = this->__stage2_int_prep(__iob, __thousands_sep);
-#else
-    char_type __atoms[__atoms_size];
-    string __grouping = this->__stage2_int_prep(__iob, __atoms, __thousands_sep);
-#endif
-    string __buf;
-    __buf.resize(__buf.capacity());
-    char* __a = &__buf[0];
-    char* __a_end = __a;
-    unsigned __g[__num_get_base::__num_get_buf_sz];
-    unsigned* __g_end = __g;
-    unsigned __dc = 0;
-    for (; __b != __e; ++__b)
-    {
-        if (__a_end == __a + __buf.size())
-        {
-            size_t __tmp = __buf.size();
-            __buf.resize(2*__buf.size());
-            __buf.resize(__buf.capacity());
-            __a = &__buf[0];
-            __a_end = __a + __tmp;
-        }
-        if (this->__stage2_int_loop(*__b, __base, __a, __a_end, __dc,
-                                    __thousands_sep, __grouping, __g, __g_end,
-                                    __atoms))
-            break;
-    }
-    if (__grouping.size() != 0 && __g_end-__g < __num_get_base::__num_get_buf_sz)
-        *__g_end++ = __dc;
-    // Stage 3
-    __v = __num_get_signed_integral<_Signed>(__a, __a_end, __err, __base);
-    // Digit grouping checked
-    __check_grouping(__grouping, __g, __g_end, __err);
-    // EOF checked
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-    return __b;
-}
-
-// unsigned
-
-template <class _CharT, class _InputIterator>
-template <class _Unsigned>
-_InputIterator
-num_get<_CharT, _InputIterator>::__do_get_unsigned(iter_type __b, iter_type __e,
-                                        ios_base& __iob,
-                                        ios_base::iostate& __err,
-                                        _Unsigned& __v) const
-{
-    // Stage 1
-    int __base = this->__get_base(__iob);
-    // Stage 2
-    char_type __thousands_sep;
-    const int __atoms_size = 26;
-#ifdef _LIBCPP_ABI_OPTIMIZED_LOCALE_NUM_GET
-    char_type __atoms1[__atoms_size];
-    const char_type *__atoms = this->__do_widen(__iob, __atoms1);
-    string __grouping = this->__stage2_int_prep(__iob, __thousands_sep);
-#else
-    char_type __atoms[__atoms_size];
-    string __grouping = this->__stage2_int_prep(__iob, __atoms, __thousands_sep);
-#endif
-    string __buf;
-    __buf.resize(__buf.capacity());
-    char* __a = &__buf[0];
-    char* __a_end = __a;
-    unsigned __g[__num_get_base::__num_get_buf_sz];
-    unsigned* __g_end = __g;
-    unsigned __dc = 0;
-    for (; __b != __e; ++__b)
-    {
-        if (__a_end == __a + __buf.size())
-        {
-            size_t __tmp = __buf.size();
-            __buf.resize(2*__buf.size());
-            __buf.resize(__buf.capacity());
-            __a = &__buf[0];
-            __a_end = __a + __tmp;
-        }
-        if (this->__stage2_int_loop(*__b, __base, __a, __a_end, __dc,
-                                    __thousands_sep, __grouping, __g, __g_end,
-                                    __atoms))
-            break;
-    }
-    if (__grouping.size() != 0 && __g_end-__g < __num_get_base::__num_get_buf_sz)
-        *__g_end++ = __dc;
-    // Stage 3
-    __v = __num_get_unsigned_integral<_Unsigned>(__a, __a_end, __err, __base);
-    // Digit grouping checked
-    __check_grouping(__grouping, __g, __g_end, __err);
-    // EOF checked
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-    return __b;
-}
-
-// floating point
-
-template <class _CharT, class _InputIterator>
-template <class _Fp>
-_InputIterator
-num_get<_CharT, _InputIterator>::__do_get_floating_point(iter_type __b, iter_type __e,
-                                        ios_base& __iob,
-                                        ios_base::iostate& __err,
-                                        _Fp& __v) const
-{
-    // Stage 1, nothing to do
-    // Stage 2
-    char_type __atoms[32];
-    char_type __decimal_point;
-    char_type __thousands_sep;
-    string __grouping = this->__stage2_float_prep(__iob, __atoms,
-                                                  __decimal_point,
-                                                  __thousands_sep);
-    string __buf;
-    __buf.resize(__buf.capacity());
-    char* __a = &__buf[0];
-    char* __a_end = __a;
-    unsigned __g[__num_get_base::__num_get_buf_sz];
-    unsigned* __g_end = __g;
-    unsigned __dc = 0;
-    bool __in_units = true;
-    char __exp = 'E';
-    for (; __b != __e; ++__b)
-    {
-        if (__a_end == __a + __buf.size())
-        {
-            size_t __tmp = __buf.size();
-            __buf.resize(2*__buf.size());
-            __buf.resize(__buf.capacity());
-            __a = &__buf[0];
-            __a_end = __a + __tmp;
-        }
-        if (this->__stage2_float_loop(*__b, __in_units, __exp, __a, __a_end,
-                                      __decimal_point, __thousands_sep,
-                                      __grouping, __g, __g_end,
-                                      __dc, __atoms))
-            break;
-    }
-    if (__grouping.size() != 0 && __in_units && __g_end-__g < __num_get_base::__num_get_buf_sz)
-        *__g_end++ = __dc;
-    // Stage 3
-    __v = __num_get_float<_Fp>(__a, __a_end, __err);
-    // Digit grouping checked
-    __check_grouping(__grouping, __g, __g_end, __err);
-    // EOF checked
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-    return __b;
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-num_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
-                                        ios_base& __iob,
-                                        ios_base::iostate& __err,
-                                        void*& __v) const
-{
-    // Stage 1
-    int __base = 16;
-    // Stage 2
-    char_type __atoms[26];
-    char_type __thousands_sep = 0;
-    string __grouping;
-    use_facet<ctype<_CharT> >(__iob.getloc()).widen(__num_get_base::__src,
-                                                    __num_get_base::__src + 26, __atoms);
-    string __buf;
-    __buf.resize(__buf.capacity());
-    char* __a = &__buf[0];
-    char* __a_end = __a;
-    unsigned __g[__num_get_base::__num_get_buf_sz];
-    unsigned* __g_end = __g;
-    unsigned __dc = 0;
-    for (; __b != __e; ++__b)
-    {
-        if (__a_end == __a + __buf.size())
-        {
-            size_t __tmp = __buf.size();
-            __buf.resize(2*__buf.size());
-            __buf.resize(__buf.capacity());
-            __a = &__buf[0];
-            __a_end = __a + __tmp;
-        }
-        if (this->__stage2_int_loop(*__b, __base, __a, __a_end, __dc,
-                                    __thousands_sep, __grouping,
-                                    __g, __g_end, __atoms))
-            break;
-    }
-    // Stage 3
-    __buf.resize(__a_end - __a);
-    if (__libcpp_sscanf_l(__buf.c_str(), _LIBCPP_GET_C_LOCALE, "%p", &__v) != 1)
-        __err = ios_base::failbit;
-    // EOF checked
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-    return __b;
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS num_get<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS num_get<wchar_t>)
-
-struct _LIBCPP_TYPE_VIS __num_put_base
-{
-protected:
-    static void __format_int(char* __fmt, const char* __len, bool __signd,
-                             ios_base::fmtflags __flags);
-    static bool __format_float(char* __fmt, const char* __len,
-                               ios_base::fmtflags __flags);
-    static char* __identify_padding(char* __nb, char* __ne,
-                                    const ios_base& __iob);
-};
-
-template <class _CharT>
-struct __num_put
-    : protected __num_put_base
-{
-    static void __widen_and_group_int(char* __nb, char* __np, char* __ne,
-                                      _CharT* __ob, _CharT*& __op, _CharT*& __oe,
-                                      const locale& __loc);
-    static void __widen_and_group_float(char* __nb, char* __np, char* __ne,
-                                        _CharT* __ob, _CharT*& __op, _CharT*& __oe,
-                                        const locale& __loc);
-};
-
-template <class _CharT>
-void
-__num_put<_CharT>::__widen_and_group_int(char* __nb, char* __np, char* __ne,
-                                         _CharT* __ob, _CharT*& __op, _CharT*& __oe,
-                                         const locale& __loc)
-{
-    const ctype<_CharT>&    __ct = use_facet<ctype<_CharT> >   (__loc);
-    const numpunct<_CharT>& __npt = use_facet<numpunct<_CharT> >(__loc);
-    string __grouping = __npt.grouping();
-    if (__grouping.empty())
-    {
-        __ct.widen(__nb, __ne, __ob);
-        __oe = __ob + (__ne - __nb);
-    }
-    else
-    {
-        __oe = __ob;
-        char* __nf = __nb;
-        if (*__nf == '-' || *__nf == '+')
-            *__oe++ = __ct.widen(*__nf++);
-        if (__ne - __nf >= 2 && __nf[0] == '0' && (__nf[1] == 'x' ||
-                                                   __nf[1] == 'X'))
-        {
-            *__oe++ = __ct.widen(*__nf++);
-            *__oe++ = __ct.widen(*__nf++);
-        }
-        reverse(__nf, __ne);
-        _CharT __thousands_sep = __npt.thousands_sep();
-        unsigned __dc = 0;
-        unsigned __dg = 0;
-        for (char* __p = __nf; __p < __ne; ++__p)
-        {
-            if (static_cast<unsigned>(__grouping[__dg]) > 0 &&
-                __dc == static_cast<unsigned>(__grouping[__dg]))
-            {
-                *__oe++ = __thousands_sep;
-                __dc = 0;
-                if (__dg < __grouping.size()-1)
-                    ++__dg;
-            }
-            *__oe++ = __ct.widen(*__p);
-            ++__dc;
-        }
-        reverse(__ob + (__nf - __nb), __oe);
-    }
-    if (__np == __ne)
-        __op = __oe;
-    else
-        __op = __ob + (__np - __nb);
-}
-
-template <class _CharT>
-void
-__num_put<_CharT>::__widen_and_group_float(char* __nb, char* __np, char* __ne,
-                                           _CharT* __ob, _CharT*& __op, _CharT*& __oe,
-                                           const locale& __loc)
-{
-    const ctype<_CharT>&    __ct = use_facet<ctype<_CharT> >   (__loc);
-    const numpunct<_CharT>& __npt = use_facet<numpunct<_CharT> >(__loc);
-    string __grouping = __npt.grouping();
-    __oe = __ob;
-    char* __nf = __nb;
-    if (*__nf == '-' || *__nf == '+')
-        *__oe++ = __ct.widen(*__nf++);
-    char* __ns;
-    if (__ne - __nf >= 2 && __nf[0] == '0' && (__nf[1] == 'x' ||
-                                               __nf[1] == 'X'))
-    {
-        *__oe++ = __ct.widen(*__nf++);
-        *__oe++ = __ct.widen(*__nf++);
-        for (__ns = __nf; __ns < __ne; ++__ns)
-            if (!isxdigit_l(*__ns, _LIBCPP_GET_C_LOCALE))
-                break;
-    }
-    else
-    {
-        for (__ns = __nf; __ns < __ne; ++__ns)
-            if (!isdigit_l(*__ns, _LIBCPP_GET_C_LOCALE))
-                break;
-    }
-    if (__grouping.empty())
-    {
-        __ct.widen(__nf, __ns, __oe);
-        __oe += __ns - __nf;
-    }
-    else
-    {
-        reverse(__nf, __ns);
-        _CharT __thousands_sep = __npt.thousands_sep();
-        unsigned __dc = 0;
-        unsigned __dg = 0;
-        for (char* __p = __nf; __p < __ns; ++__p)
-        {
-            if (__grouping[__dg] > 0 && __dc == static_cast<unsigned>(__grouping[__dg]))
-            {
-                *__oe++ = __thousands_sep;
-                __dc = 0;
-                if (__dg < __grouping.size()-1)
-                    ++__dg;
-            }
-            *__oe++ = __ct.widen(*__p);
-            ++__dc;
-        }
-        reverse(__ob + (__nf - __nb), __oe);
-    }
-    for (__nf = __ns; __nf < __ne; ++__nf)
-    {
-        if (*__nf == '.')
-        {
-            *__oe++ = __npt.decimal_point();
-            ++__nf;
-            break;
-        }
-        else
-            *__oe++ = __ct.widen(*__nf);
-    }
-    __ct.widen(__nf, __ne, __oe);
-    __oe += __ne - __nf;
-    if (__np == __ne)
-        __op = __oe;
-    else
-        __op = __ob + (__np - __nb);
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(struct _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __num_put<char>)
-_LIBCPP_EXTERN_TEMPLATE2(struct _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __num_put<wchar_t>)
-
-template <class _CharT, class _OutputIterator = ostreambuf_iterator<_CharT> >
-class _LIBCPP_TEMPLATE_VIS num_put
-    : public locale::facet,
-      private __num_put<_CharT>
-{
-public:
-    typedef _CharT char_type;
-    typedef _OutputIterator iter_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit num_put(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
-                  bool __v) const
-    {
-        return do_put(__s, __iob, __fl, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
-                  long __v) const
-    {
-        return do_put(__s, __iob, __fl, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
-                  long long __v) const
-    {
-        return do_put(__s, __iob, __fl, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
-                  unsigned long __v) const
-    {
-        return do_put(__s, __iob, __fl, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
-                  unsigned long long __v) const
-    {
-        return do_put(__s, __iob, __fl, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
-                  double __v) const
-    {
-        return do_put(__s, __iob, __fl, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
-                  long double __v) const
-    {
-        return do_put(__s, __iob, __fl, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
-                  const void* __v) const
-    {
-        return do_put(__s, __iob, __fl, __v);
-    }
-
-    static locale::id id;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~num_put() {}
-
-    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
-                             bool __v) const;
-    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
-                             long __v) const;
-    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
-                             long long __v) const;
-    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
-                             unsigned long) const;
-    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
-                             unsigned long long) const;
-    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
-                             double __v) const;
-    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
-                             long double __v) const;
-    virtual iter_type do_put(iter_type __s, ios_base& __iob, char_type __fl,
-                             const void* __v) const;
-};
-
-template <class _CharT, class _OutputIterator>
-locale::id
-num_put<_CharT, _OutputIterator>::id;
-
-template <class _CharT, class _OutputIterator>
-_LIBCPP_HIDDEN
-_OutputIterator
-__pad_and_output(_OutputIterator __s,
-                 const _CharT* __ob, const _CharT* __op, const _CharT* __oe,
-                 ios_base& __iob, _CharT __fl)
-{
-    streamsize __sz = __oe - __ob;
-    streamsize __ns = __iob.width();
-    if (__ns > __sz)
-        __ns -= __sz;
-    else
-        __ns = 0;
-    for (;__ob < __op; ++__ob, ++__s)
-        *__s = *__ob;
-    for (; __ns; --__ns, ++__s)
-        *__s = __fl;
-    for (; __ob < __oe; ++__ob, ++__s)
-        *__s = *__ob;
-    __iob.width(0);
-    return __s;
-}
-
-#if !defined(__APPLE__) || \
-    (defined(__MAC_OS_X_VERSION_MIN_REQUIRED) && __MAC_OS_X_VERSION_MIN_REQUIRED > __MAC_10_8) || \
-    (defined(__IPHONE_OS_VERSION_MIN_REQUIRED) && __IPHONE_OS_VERSION_MIN_REQUIRED > __IPHONE_6_0)
-
-template <class _CharT, class _Traits>
-_LIBCPP_HIDDEN
-ostreambuf_iterator<_CharT, _Traits>
-__pad_and_output(ostreambuf_iterator<_CharT, _Traits> __s,
-                 const _CharT* __ob, const _CharT* __op, const _CharT* __oe,
-                 ios_base& __iob, _CharT __fl)
-{
-    if (__s.__sbuf_ == nullptr)
-        return __s;
-    streamsize __sz = __oe - __ob;
-    streamsize __ns = __iob.width();
-    if (__ns > __sz)
-        __ns -= __sz;
-    else
-        __ns = 0;
-    streamsize __np = __op - __ob;
-    if (__np > 0)
-    {
-        if (__s.__sbuf_->sputn(__ob, __np) != __np)
-        {
-            __s.__sbuf_ = nullptr;
-            return __s;
-        }
-    }
-    if (__ns > 0)
-    {
-        basic_string<_CharT, _Traits> __sp(__ns, __fl);
-        if (__s.__sbuf_->sputn(__sp.data(), __ns) != __ns)
-        {
-            __s.__sbuf_ = nullptr;
-            return __s;
-        }
-    }
-    __np = __oe - __op;
-    if (__np > 0)
-    {
-        if (__s.__sbuf_->sputn(__op, __np) != __np)
-        {
-            __s.__sbuf_ = nullptr;
-            return __s;
-        }
-    }
-    __iob.width(0);
-    return __s;
-}
-
-#endif
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
-                                         char_type __fl, bool __v) const
-{
-    if ((__iob.flags() & ios_base::boolalpha) == 0)
-        return do_put(__s, __iob, __fl, (unsigned long)__v);
-    const numpunct<char_type>& __np = use_facet<numpunct<char_type> >(__iob.getloc());
-    typedef typename numpunct<char_type>::string_type string_type;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    string_type __tmp(__v ? __np.truename() : __np.falsename());
-    string_type __nm = _VSTD::move(__tmp);
-#else
-    string_type __nm = __v ? __np.truename() : __np.falsename();
-#endif
-    for (typename string_type::iterator __i = __nm.begin(); __i != __nm.end(); ++__i, ++__s)
-        *__s = *__i;
-    return __s;
-}
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
-                                         char_type __fl, long __v) const
-{
-    // Stage 1 - Get number in narrow char
-    char __fmt[6] = {'%', 0};
-    const char* __len = "l";
-    this->__format_int(__fmt+1, __len, true, __iob.flags());
-    const unsigned __nbuf = (numeric_limits<long>::digits / 3)
-                          + ((numeric_limits<long>::digits % 3) != 0)
-                          + ((__iob.flags() & ios_base::showbase) != 0)
-                          + 2;
-    char __nar[__nbuf];
-    int __nc = __libcpp_snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
-    char* __ne = __nar + __nc;
-    char* __np = this->__identify_padding(__nar, __ne, __iob);
-    // Stage 2 - Widen __nar while adding thousands separators
-    char_type __o[2*(__nbuf-1) - 1];
-    char_type* __op;  // pad here
-    char_type* __oe;  // end of output
-    this->__widen_and_group_int(__nar, __np, __ne, __o, __op, __oe, __iob.getloc());
-    // [__o, __oe) contains thousands_sep'd wide number
-    // Stage 3 & 4
-    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
-}
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
-                                         char_type __fl, long long __v) const
-{
-    // Stage 1 - Get number in narrow char
-    char __fmt[8] = {'%', 0};
-    const char* __len = "ll";
-    this->__format_int(__fmt+1, __len, true, __iob.flags());
-    const unsigned __nbuf = (numeric_limits<long long>::digits / 3)
-                          + ((numeric_limits<long long>::digits % 3) != 0)
-                          + ((__iob.flags() & ios_base::showbase) != 0)
-                          + 2;
-    char __nar[__nbuf];
-    int __nc = __libcpp_snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
-    char* __ne = __nar + __nc;
-    char* __np = this->__identify_padding(__nar, __ne, __iob);
-    // Stage 2 - Widen __nar while adding thousands separators
-    char_type __o[2*(__nbuf-1) - 1];
-    char_type* __op;  // pad here
-    char_type* __oe;  // end of output
-    this->__widen_and_group_int(__nar, __np, __ne, __o, __op, __oe, __iob.getloc());
-    // [__o, __oe) contains thousands_sep'd wide number
-    // Stage 3 & 4
-    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
-}
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
-                                         char_type __fl, unsigned long __v) const
-{
-    // Stage 1 - Get number in narrow char
-    char __fmt[6] = {'%', 0};
-    const char* __len = "l";
-    this->__format_int(__fmt+1, __len, false, __iob.flags());
-    const unsigned __nbuf = (numeric_limits<unsigned long>::digits / 3)
-                          + ((numeric_limits<unsigned long>::digits % 3) != 0)
-                          + ((__iob.flags() & ios_base::showbase) != 0)
-                          + 1;
-    char __nar[__nbuf];
-    int __nc = __libcpp_snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
-    char* __ne = __nar + __nc;
-    char* __np = this->__identify_padding(__nar, __ne, __iob);
-    // Stage 2 - Widen __nar while adding thousands separators
-    char_type __o[2*(__nbuf-1) - 1];
-    char_type* __op;  // pad here
-    char_type* __oe;  // end of output
-    this->__widen_and_group_int(__nar, __np, __ne, __o, __op, __oe, __iob.getloc());
-    // [__o, __oe) contains thousands_sep'd wide number
-    // Stage 3 & 4
-    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
-}
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
-                                         char_type __fl, unsigned long long __v) const
-{
-    // Stage 1 - Get number in narrow char
-    char __fmt[8] = {'%', 0};
-    const char* __len = "ll";
-    this->__format_int(__fmt+1, __len, false, __iob.flags());
-    const unsigned __nbuf = (numeric_limits<unsigned long long>::digits / 3)
-                          + ((numeric_limits<unsigned long long>::digits % 3) != 0)
-                          + ((__iob.flags() & ios_base::showbase) != 0)
-                          + 1;
-    char __nar[__nbuf];
-    int __nc = __libcpp_snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
-    char* __ne = __nar + __nc;
-    char* __np = this->__identify_padding(__nar, __ne, __iob);
-    // Stage 2 - Widen __nar while adding thousands separators
-    char_type __o[2*(__nbuf-1) - 1];
-    char_type* __op;  // pad here
-    char_type* __oe;  // end of output
-    this->__widen_and_group_int(__nar, __np, __ne, __o, __op, __oe, __iob.getloc());
-    // [__o, __oe) contains thousands_sep'd wide number
-    // Stage 3 & 4
-    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
-}
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
-                                         char_type __fl, double __v) const
-{
-    // Stage 1 - Get number in narrow char
-    char __fmt[8] = {'%', 0};
-    const char* __len = "";
-    bool __specify_precision = this->__format_float(__fmt+1, __len, __iob.flags());
-    const unsigned __nbuf = 30;
-    char __nar[__nbuf];
-    char* __nb = __nar;
-    int __nc;
-    if (__specify_precision)
-        __nc = __libcpp_snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt,
-                                   (int)__iob.precision(), __v);
-    else
-        __nc = __libcpp_snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt, __v);
-    unique_ptr<char, void(*)(void*)> __nbh(0, free);
-    if (__nc > static_cast<int>(__nbuf-1))
-    {
-        if (__specify_precision)
-            __nc = __libcpp_asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, (int)__iob.precision(), __v);
-        else
-            __nc = __libcpp_asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, __v);
-        if (__nc == -1)
-            __throw_bad_alloc();
-        __nbh.reset(__nb);
-    }
-    char* __ne = __nb + __nc;
-    char* __np = this->__identify_padding(__nb, __ne, __iob);
-    // Stage 2 - Widen __nar while adding thousands separators
-    char_type __o[2*(__nbuf-1) - 1];
-    char_type* __ob = __o;
-    unique_ptr<char_type, void(*)(void*)> __obh(0, free);
-    if (__nb != __nar)
-    {
-        __ob = (char_type*)malloc(2*static_cast<size_t>(__nc)*sizeof(char_type));
-        if (__ob == 0)
-            __throw_bad_alloc();
-        __obh.reset(__ob);
-    }
-    char_type* __op;  // pad here
-    char_type* __oe;  // end of output
-    this->__widen_and_group_float(__nb, __np, __ne, __ob, __op, __oe, __iob.getloc());
-    // [__o, __oe) contains thousands_sep'd wide number
-    // Stage 3 & 4
-    __s = __pad_and_output(__s, __ob, __op, __oe, __iob, __fl);
-    return __s;
-}
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
-                                         char_type __fl, long double __v) const
-{
-    // Stage 1 - Get number in narrow char
-    char __fmt[8] = {'%', 0};
-    const char* __len = "L";
-    bool __specify_precision = this->__format_float(__fmt+1, __len, __iob.flags());
-    const unsigned __nbuf = 30;
-    char __nar[__nbuf];
-    char* __nb = __nar;
-    int __nc;
-    if (__specify_precision)
-        __nc = __libcpp_snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt,
-                                   (int)__iob.precision(), __v);
-    else
-        __nc = __libcpp_snprintf_l(__nb, __nbuf, _LIBCPP_GET_C_LOCALE, __fmt, __v);
-    unique_ptr<char, void(*)(void*)> __nbh(0, free);
-    if (__nc > static_cast<int>(__nbuf-1))
-    {
-        if (__specify_precision)
-            __nc = __libcpp_asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, (int)__iob.precision(), __v);
-        else
-            __nc = __libcpp_asprintf_l(&__nb, _LIBCPP_GET_C_LOCALE, __fmt, __v);
-        if (__nc == -1)
-            __throw_bad_alloc();
-        __nbh.reset(__nb);
-    }
-    char* __ne = __nb + __nc;
-    char* __np = this->__identify_padding(__nb, __ne, __iob);
-    // Stage 2 - Widen __nar while adding thousands separators
-    char_type __o[2*(__nbuf-1) - 1];
-    char_type* __ob = __o;
-    unique_ptr<char_type, void(*)(void*)> __obh(0, free);
-    if (__nb != __nar)
-    {
-        __ob = (char_type*)malloc(2*static_cast<size_t>(__nc)*sizeof(char_type));
-        if (__ob == 0)
-            __throw_bad_alloc();
-        __obh.reset(__ob);
-    }
-    char_type* __op;  // pad here
-    char_type* __oe;  // end of output
-    this->__widen_and_group_float(__nb, __np, __ne, __ob, __op, __oe, __iob.getloc());
-    // [__o, __oe) contains thousands_sep'd wide number
-    // Stage 3 & 4
-    __s = __pad_and_output(__s, __ob, __op, __oe, __iob, __fl);
-    return __s;
-}
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-num_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base& __iob,
-                                         char_type __fl, const void* __v) const
-{
-    // Stage 1 - Get pointer in narrow char
-    char __fmt[6] = "%p";
-    const unsigned __nbuf = 20;
-    char __nar[__nbuf];
-    int __nc = __libcpp_snprintf_l(__nar, sizeof(__nar), _LIBCPP_GET_C_LOCALE, __fmt, __v);
-    char* __ne = __nar + __nc;
-    char* __np = this->__identify_padding(__nar, __ne, __iob);
-    // Stage 2 - Widen __nar
-    char_type __o[2*(__nbuf-1) - 1];
-    char_type* __op;  // pad here
-    char_type* __oe;  // end of output
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
-    __ct.widen(__nar, __ne, __o);
-    __oe = __o + (__ne - __nar);
-    if (__np == __ne)
-        __op = __oe;
-    else
-        __op = __o + (__np - __nar);
-    // [__o, __oe) contains wide number
-    // Stage 3 & 4
-    return __pad_and_output(__s, __o, __op, __oe, __iob, __fl);
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS num_put<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS num_put<wchar_t>)
-
-template <class _CharT, class _InputIterator>
-_LIBCPP_HIDDEN
-int
-__get_up_to_n_digits(_InputIterator& __b, _InputIterator __e,
-                     ios_base::iostate& __err, const ctype<_CharT>& __ct, int __n)
-{
-    // Precondition:  __n >= 1
-    if (__b == __e)
-    {
-        __err |= ios_base::eofbit | ios_base::failbit;
-        return 0;
-    }
-    // get first digit
-    _CharT __c = *__b;
-    if (!__ct.is(ctype_base::digit, __c))
-    {
-        __err |= ios_base::failbit;
-        return 0;
-    }
-    int __r = __ct.narrow(__c, 0) - '0';
-    for (++__b, (void) --__n; __b != __e && __n > 0; ++__b, (void) --__n)
-    {
-        // get next digit
-        __c = *__b;
-        if (!__ct.is(ctype_base::digit, __c))
-            return __r;
-        __r = __r * 10 + __ct.narrow(__c, 0) - '0';
-    }
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-    return __r;
-}
-
-class _LIBCPP_TYPE_VIS time_base
-{
-public:
-    enum dateorder {no_order, dmy, mdy, ymd, ydm};
-};
-
-template <class _CharT>
-class _LIBCPP_TEMPLATE_VIS __time_get_c_storage
-{
-protected:
-    typedef basic_string<_CharT> string_type;
-
-    virtual const string_type* __weeks() const;
-    virtual const string_type* __months() const;
-    virtual const string_type* __am_pm() const;
-    virtual const string_type& __c() const;
-    virtual const string_type& __r() const;
-    virtual const string_type& __x() const;
-    virtual const string_type& __X() const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__time_get_c_storage() {}
-};
-
-template <> _LIBCPP_FUNC_VIS const string* __time_get_c_storage<char>::__weeks() const;
-template <> _LIBCPP_FUNC_VIS const string* __time_get_c_storage<char>::__months() const;
-template <> _LIBCPP_FUNC_VIS const string* __time_get_c_storage<char>::__am_pm() const;
-template <> _LIBCPP_FUNC_VIS const string& __time_get_c_storage<char>::__c() const;
-template <> _LIBCPP_FUNC_VIS const string& __time_get_c_storage<char>::__r() const;
-template <> _LIBCPP_FUNC_VIS const string& __time_get_c_storage<char>::__x() const;
-template <> _LIBCPP_FUNC_VIS const string& __time_get_c_storage<char>::__X() const;
-
-template <> _LIBCPP_FUNC_VIS const wstring* __time_get_c_storage<wchar_t>::__weeks() const;
-template <> _LIBCPP_FUNC_VIS const wstring* __time_get_c_storage<wchar_t>::__months() const;
-template <> _LIBCPP_FUNC_VIS const wstring* __time_get_c_storage<wchar_t>::__am_pm() const;
-template <> _LIBCPP_FUNC_VIS const wstring& __time_get_c_storage<wchar_t>::__c() const;
-template <> _LIBCPP_FUNC_VIS const wstring& __time_get_c_storage<wchar_t>::__r() const;
-template <> _LIBCPP_FUNC_VIS const wstring& __time_get_c_storage<wchar_t>::__x() const;
-template <> _LIBCPP_FUNC_VIS const wstring& __time_get_c_storage<wchar_t>::__X() const;
-
-template <class _CharT, class _InputIterator = istreambuf_iterator<_CharT> >
-class _LIBCPP_TEMPLATE_VIS time_get
-    : public locale::facet,
-      public time_base,
-      private __time_get_c_storage<_CharT>
-{
-public:
-    typedef _CharT                  char_type;
-    typedef _InputIterator          iter_type;
-    typedef time_base::dateorder    dateorder;
-    typedef basic_string<char_type> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit time_get(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    dateorder date_order() const
-    {
-        return this->do_date_order();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get_time(iter_type __b, iter_type __e, ios_base& __iob,
-                       ios_base::iostate& __err, tm* __tm) const
-    {
-        return do_get_time(__b, __e, __iob, __err, __tm);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get_date(iter_type __b, iter_type __e, ios_base& __iob,
-                       ios_base::iostate& __err, tm* __tm) const
-    {
-        return do_get_date(__b, __e, __iob, __err, __tm);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get_weekday(iter_type __b, iter_type __e, ios_base& __iob,
-                          ios_base::iostate& __err, tm* __tm) const
-    {
-        return do_get_weekday(__b, __e, __iob, __err, __tm);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get_monthname(iter_type __b, iter_type __e, ios_base& __iob,
-                            ios_base::iostate& __err, tm* __tm) const
-    {
-        return do_get_monthname(__b, __e, __iob, __err, __tm);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get_year(iter_type __b, iter_type __e, ios_base& __iob,
-                       ios_base::iostate& __err, tm* __tm) const
-    {
-        return do_get_year(__b, __e, __iob, __err, __tm);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, tm *__tm,
-                  char __fmt, char __mod = 0) const
-    {
-        return do_get(__b, __e, __iob, __err, __tm, __fmt, __mod);
-    }
-
-    iter_type get(iter_type __b, iter_type __e, ios_base& __iob,
-                  ios_base::iostate& __err, tm* __tm,
-                  const char_type* __fmtb, const char_type* __fmte) const;
-
-    static locale::id id;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~time_get() {}
-
-    virtual dateorder do_date_order() const;
-    virtual iter_type do_get_time(iter_type __b, iter_type __e, ios_base& __iob,
-                                  ios_base::iostate& __err, tm* __tm) const;
-    virtual iter_type do_get_date(iter_type __b, iter_type __e, ios_base& __iob,
-                                  ios_base::iostate& __err, tm* __tm) const;
-    virtual iter_type do_get_weekday(iter_type __b, iter_type __e, ios_base& __iob,
-                                     ios_base::iostate& __err, tm* __tm) const;
-    virtual iter_type do_get_monthname(iter_type __b, iter_type __e, ios_base& __iob,
-                                       ios_base::iostate& __err, tm* __tm) const;
-    virtual iter_type do_get_year(iter_type __b, iter_type __e, ios_base& __iob,
-                                  ios_base::iostate& __err, tm* __tm) const;
-    virtual iter_type do_get(iter_type __b, iter_type __e, ios_base& __iob,
-                             ios_base::iostate& __err, tm* __tm,
-                             char __fmt, char __mod) const;
-private:
-    void __get_white_space(iter_type& __b, iter_type __e,
-                           ios_base::iostate& __err, const ctype<char_type>& __ct) const;
-    void __get_percent(iter_type& __b, iter_type __e, ios_base::iostate& __err,
-                       const ctype<char_type>& __ct) const;
-
-    void __get_weekdayname(int& __m,
-                           iter_type& __b, iter_type __e,
-                           ios_base::iostate& __err,
-                           const ctype<char_type>& __ct) const;
-    void __get_monthname(int& __m,
-                         iter_type& __b, iter_type __e,
-                         ios_base::iostate& __err,
-                         const ctype<char_type>& __ct) const;
-    void __get_day(int& __d,
-                   iter_type& __b, iter_type __e,
-                   ios_base::iostate& __err,
-                   const ctype<char_type>& __ct) const;
-    void __get_month(int& __m,
-                     iter_type& __b, iter_type __e,
-                     ios_base::iostate& __err,
-                     const ctype<char_type>& __ct) const;
-    void __get_year(int& __y,
-                   iter_type& __b, iter_type __e,
-                   ios_base::iostate& __err,
-                   const ctype<char_type>& __ct) const;
-    void __get_year4(int& __y,
-                    iter_type& __b, iter_type __e,
-                    ios_base::iostate& __err,
-                    const ctype<char_type>& __ct) const;
-    void __get_hour(int& __d,
-                    iter_type& __b, iter_type __e,
-                    ios_base::iostate& __err,
-                    const ctype<char_type>& __ct) const;
-    void __get_12_hour(int& __h,
-                       iter_type& __b, iter_type __e,
-                       ios_base::iostate& __err,
-                       const ctype<char_type>& __ct) const;
-    void __get_am_pm(int& __h,
-                     iter_type& __b, iter_type __e,
-                     ios_base::iostate& __err,
-                     const ctype<char_type>& __ct) const;
-    void __get_minute(int& __m,
-                      iter_type& __b, iter_type __e,
-                      ios_base::iostate& __err,
-                      const ctype<char_type>& __ct) const;
-    void __get_second(int& __s,
-                      iter_type& __b, iter_type __e,
-                      ios_base::iostate& __err,
-                      const ctype<char_type>& __ct) const;
-    void __get_weekday(int& __w,
-                       iter_type& __b, iter_type __e,
-                       ios_base::iostate& __err,
-                       const ctype<char_type>& __ct) const;
-    void __get_day_year_num(int& __w,
-                            iter_type& __b, iter_type __e,
-                            ios_base::iostate& __err,
-                            const ctype<char_type>& __ct) const;
-};
-
-template <class _CharT, class _InputIterator>
-locale::id
-time_get<_CharT, _InputIterator>::id;
-
-// time_get primitives
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_weekdayname(int& __w,
-                                                    iter_type& __b, iter_type __e,
-                                                    ios_base::iostate& __err,
-                                                    const ctype<char_type>& __ct) const
-{
-    // Note:  ignoring case comes from the POSIX strptime spec
-    const string_type* __wk = this->__weeks();
-    ptrdiff_t __i = __scan_keyword(__b, __e, __wk, __wk+14, __ct, __err, false) - __wk;
-    if (__i < 14)
-        __w = __i % 7;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_monthname(int& __m,
-                                                  iter_type& __b, iter_type __e,
-                                                  ios_base::iostate& __err,
-                                                  const ctype<char_type>& __ct) const
-{
-    // Note:  ignoring case comes from the POSIX strptime spec
-    const string_type* __month = this->__months();
-    ptrdiff_t __i = __scan_keyword(__b, __e, __month, __month+24, __ct, __err, false) - __month;
-    if (__i < 24)
-        __m = __i % 12;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_day(int& __d,
-                                            iter_type& __b, iter_type __e,
-                                            ios_base::iostate& __err,
-                                            const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
-    if (!(__err & ios_base::failbit) && 1 <= __t && __t <= 31)
-        __d = __t;
-    else
-        __err |= ios_base::failbit;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_month(int& __m,
-                                              iter_type& __b, iter_type __e,
-                                              ios_base::iostate& __err,
-                                              const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2) - 1;
-    if (!(__err & ios_base::failbit) && __t <= 11)
-        __m = __t;
-    else
-        __err |= ios_base::failbit;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_year(int& __y,
-                                             iter_type& __b, iter_type __e,
-                                             ios_base::iostate& __err,
-                                             const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 4);
-    if (!(__err & ios_base::failbit))
-    {
-        if (__t < 69)
-            __t += 2000;
-        else if (69 <= __t && __t <= 99)
-            __t += 1900;
-        __y = __t - 1900;
-    }
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_year4(int& __y,
-                                              iter_type& __b, iter_type __e,
-                                              ios_base::iostate& __err,
-                                              const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 4);
-    if (!(__err & ios_base::failbit))
-        __y = __t - 1900;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_hour(int& __h,
-                                             iter_type& __b, iter_type __e,
-                                             ios_base::iostate& __err,
-                                             const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
-    if (!(__err & ios_base::failbit) && __t <= 23)
-        __h = __t;
-    else
-        __err |= ios_base::failbit;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_12_hour(int& __h,
-                                                iter_type& __b, iter_type __e,
-                                                ios_base::iostate& __err,
-                                                const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
-    if (!(__err & ios_base::failbit) && 1 <= __t && __t <= 12)
-        __h = __t;
-    else
-        __err |= ios_base::failbit;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_minute(int& __m,
-                                               iter_type& __b, iter_type __e,
-                                               ios_base::iostate& __err,
-                                               const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
-    if (!(__err & ios_base::failbit) && __t <= 59)
-        __m = __t;
-    else
-        __err |= ios_base::failbit;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_second(int& __s,
-                                               iter_type& __b, iter_type __e,
-                                               ios_base::iostate& __err,
-                                               const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 2);
-    if (!(__err & ios_base::failbit) && __t <= 60)
-        __s = __t;
-    else
-        __err |= ios_base::failbit;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_weekday(int& __w,
-                                                iter_type& __b, iter_type __e,
-                                                ios_base::iostate& __err,
-                                                const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 1);
-    if (!(__err & ios_base::failbit) && __t <= 6)
-        __w = __t;
-    else
-        __err |= ios_base::failbit;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_day_year_num(int& __d,
-                                                     iter_type& __b, iter_type __e,
-                                                     ios_base::iostate& __err,
-                                                     const ctype<char_type>& __ct) const
-{
-    int __t = __get_up_to_n_digits(__b, __e, __err, __ct, 3);
-    if (!(__err & ios_base::failbit) && __t <= 365)
-        __d = __t;
-    else
-        __err |= ios_base::failbit;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_white_space(iter_type& __b, iter_type __e,
-                                                    ios_base::iostate& __err,
-                                                    const ctype<char_type>& __ct) const
-{
-    for (; __b != __e && __ct.is(ctype_base::space, *__b); ++__b)
-        ;
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_am_pm(int& __h,
-                                              iter_type& __b, iter_type __e,
-                                              ios_base::iostate& __err,
-                                              const ctype<char_type>& __ct) const
-{
-    const string_type* __ap = this->__am_pm();
-    if (__ap[0].size() + __ap[1].size() == 0)
-    {
-        __err |= ios_base::failbit;
-        return;
-    }
-    ptrdiff_t __i = __scan_keyword(__b, __e, __ap, __ap+2, __ct, __err, false) - __ap;
-    if (__i == 0 && __h == 12)
-        __h = 0;
-    else if (__i == 1 && __h < 12)
-        __h += 12;
-}
-
-template <class _CharT, class _InputIterator>
-void
-time_get<_CharT, _InputIterator>::__get_percent(iter_type& __b, iter_type __e,
-                                                ios_base::iostate& __err,
-                                                const ctype<char_type>& __ct) const
-{
-    if (__b == __e)
-    {
-        __err |= ios_base::eofbit | ios_base::failbit;
-        return;
-    }
-    if (__ct.narrow(*__b, 0) != '%')
-        __err |= ios_base::failbit;
-    else if(++__b == __e)
-        __err |= ios_base::eofbit;
-}
-
-// time_get end primitives
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-time_get<_CharT, _InputIterator>::get(iter_type __b, iter_type __e,
-                                      ios_base& __iob,
-                                      ios_base::iostate& __err, tm* __tm,
-                                      const char_type* __fmtb, const char_type* __fmte) const
-{
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
-    __err = ios_base::goodbit;
-    while (__fmtb != __fmte && __err == ios_base::goodbit)
-    {
-        if (__b == __e)
-        {
-            __err = ios_base::failbit;
-            break;
-        }
-        if (__ct.narrow(*__fmtb, 0) == '%')
-        {
-            if (++__fmtb == __fmte)
-            {
-                __err = ios_base::failbit;
-                break;
-            }
-            char __cmd = __ct.narrow(*__fmtb, 0);
-            char __opt = '\0';
-            if (__cmd == 'E' || __cmd == '0')
-            {
-                if (++__fmtb == __fmte)
-                {
-                    __err = ios_base::failbit;
-                    break;
-                }
-                __opt = __cmd;
-                __cmd = __ct.narrow(*__fmtb, 0);
-            }
-            __b = do_get(__b, __e, __iob, __err, __tm, __cmd, __opt);
-            ++__fmtb;
-        }
-        else if (__ct.is(ctype_base::space, *__fmtb))
-        {
-            for (++__fmtb; __fmtb != __fmte && __ct.is(ctype_base::space, *__fmtb); ++__fmtb)
-                ;
-            for (        ;    __b != __e    && __ct.is(ctype_base::space, *__b);    ++__b)
-                ;
-        }
-        else if (__ct.toupper(*__b) == __ct.toupper(*__fmtb))
-        {
-            ++__b;
-            ++__fmtb;
-        }
-        else
-            __err = ios_base::failbit;
-    }
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-    return __b;
-}
-
-template <class _CharT, class _InputIterator>
-typename time_get<_CharT, _InputIterator>::dateorder
-time_get<_CharT, _InputIterator>::do_date_order() const
-{
-    return mdy;
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-time_get<_CharT, _InputIterator>::do_get_time(iter_type __b, iter_type __e,
-                                              ios_base& __iob,
-                                              ios_base::iostate& __err,
-                                              tm* __tm) const
-{
-    const char_type __fmt[] = {'%', 'H', ':', '%', 'M', ':', '%', 'S'};
-    return get(__b, __e, __iob, __err, __tm, __fmt, __fmt + sizeof(__fmt)/sizeof(__fmt[0]));
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-time_get<_CharT, _InputIterator>::do_get_date(iter_type __b, iter_type __e,
-                                              ios_base& __iob,
-                                              ios_base::iostate& __err,
-                                              tm* __tm) const
-{
-    const string_type& __fmt = this->__x();
-    return get(__b, __e, __iob, __err, __tm, __fmt.data(), __fmt.data() + __fmt.size());
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-time_get<_CharT, _InputIterator>::do_get_weekday(iter_type __b, iter_type __e,
-                                                 ios_base& __iob,
-                                                 ios_base::iostate& __err,
-                                                 tm* __tm) const
-{
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
-    __get_weekdayname(__tm->tm_wday, __b, __e, __err, __ct);
-    return __b;
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-time_get<_CharT, _InputIterator>::do_get_monthname(iter_type __b, iter_type __e,
-                                                   ios_base& __iob,
-                                                   ios_base::iostate& __err,
-                                                   tm* __tm) const
-{
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
-    __get_monthname(__tm->tm_mon, __b, __e, __err, __ct);
-    return __b;
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-time_get<_CharT, _InputIterator>::do_get_year(iter_type __b, iter_type __e,
-                                              ios_base& __iob,
-                                              ios_base::iostate& __err,
-                                              tm* __tm) const
-{
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
-    __get_year(__tm->tm_year, __b, __e, __err, __ct);
-    return __b;
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-time_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
-                                         ios_base& __iob,
-                                         ios_base::iostate& __err, tm* __tm,
-                                         char __fmt, char) const
-{
-    __err = ios_base::goodbit;
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
-    switch (__fmt)
-    {
-    case 'a':
-    case 'A':
-        __get_weekdayname(__tm->tm_wday, __b, __e, __err, __ct);
-        break;
-    case 'b':
-    case 'B':
-    case 'h':
-        __get_monthname(__tm->tm_mon, __b, __e, __err, __ct);
-        break;
-    case 'c':
-        {
-        const string_type& __fm = this->__c();
-        __b = get(__b, __e, __iob, __err, __tm, __fm.data(), __fm.data() + __fm.size());
-        }
-        break;
-    case 'd':
-    case 'e':
-        __get_day(__tm->tm_mday, __b, __e, __err, __ct);
-        break;
-    case 'D':
-        {
-        const char_type __fm[] = {'%', 'm', '/', '%', 'd', '/', '%', 'y'};
-        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
-        }
-        break;
-    case 'F':
-        {
-        const char_type __fm[] = {'%', 'Y', '-', '%', 'm', '-', '%', 'd'};
-        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
-        }
-        break;
-    case 'H':
-        __get_hour(__tm->tm_hour, __b, __e, __err, __ct);
-        break;
-    case 'I':
-        __get_12_hour(__tm->tm_hour, __b, __e, __err, __ct);
-        break;
-    case 'j':
-        __get_day_year_num(__tm->tm_yday, __b, __e, __err, __ct);
-        break;
-    case 'm':
-        __get_month(__tm->tm_mon, __b, __e, __err, __ct);
-        break;
-    case 'M':
-        __get_minute(__tm->tm_min, __b, __e, __err, __ct);
-        break;
-    case 'n':
-    case 't':
-        __get_white_space(__b, __e, __err, __ct);
-        break;
-    case 'p':
-        __get_am_pm(__tm->tm_hour, __b, __e, __err, __ct);
-        break;
-    case 'r':
-        {
-        const char_type __fm[] = {'%', 'I', ':', '%', 'M', ':', '%', 'S', ' ', '%', 'p'};
-        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
-        }
-        break;
-    case 'R':
-        {
-        const char_type __fm[] = {'%', 'H', ':', '%', 'M'};
-        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
-        }
-        break;
-    case 'S':
-        __get_second(__tm->tm_sec, __b, __e, __err, __ct);
-        break;
-    case 'T':
-        {
-        const char_type __fm[] = {'%', 'H', ':', '%', 'M', ':', '%', 'S'};
-        __b = get(__b, __e, __iob, __err, __tm, __fm, __fm + sizeof(__fm)/sizeof(__fm[0]));
-        }
-        break;
-    case 'w':
-        __get_weekday(__tm->tm_wday, __b, __e, __err, __ct);
-        break;
-    case 'x':
-        return do_get_date(__b, __e, __iob, __err, __tm);
-    case 'X':
-        {
-        const string_type& __fm = this->__X();
-        __b = get(__b, __e, __iob, __err, __tm, __fm.data(), __fm.data() + __fm.size());
-        }
-        break;
-    case 'y':
-        __get_year(__tm->tm_year, __b, __e, __err, __ct);
-        break;
-    case 'Y':
-        __get_year4(__tm->tm_year, __b, __e, __err, __ct);
-        break;
-    case '%':
-        __get_percent(__b, __e, __err, __ct);
-        break;
-    default:
-        __err |= ios_base::failbit;
-    }
-    return __b;
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS time_get<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS time_get<wchar_t>)
-
-class _LIBCPP_TYPE_VIS __time_get
-{
-protected:
-    locale_t __loc_;
-
-    __time_get(const char* __nm);
-    __time_get(const string& __nm);
-    ~__time_get();
-};
-
-template <class _CharT>
-class _LIBCPP_TEMPLATE_VIS __time_get_storage
-    : public __time_get
-{
-protected:
-    typedef basic_string<_CharT> string_type;
-
-    string_type __weeks_[14];
-    string_type __months_[24];
-    string_type __am_pm_[2];
-    string_type __c_;
-    string_type __r_;
-    string_type __x_;
-    string_type __X_;
-
-    explicit __time_get_storage(const char* __nm);
-    explicit __time_get_storage(const string& __nm);
-
-    _LIBCPP_INLINE_VISIBILITY ~__time_get_storage() {}
-
-    time_base::dateorder __do_date_order() const;
-
-private:
-    void init(const ctype<_CharT>&);
-    string_type __analyze(char __fmt, const ctype<_CharT>&);
-};
-
-#define _LIBCPP_TIME_GET_STORAGE_EXPLICIT_INSTANTIATION(_CharT) \
-template <> _LIBCPP_FUNC_VIS time_base::dateorder __time_get_storage<_CharT>::__do_date_order() const; \
-template <> _LIBCPP_FUNC_VIS __time_get_storage<_CharT>::__time_get_storage(const char*); \
-template <> _LIBCPP_FUNC_VIS __time_get_storage<_CharT>::__time_get_storage(const string&); \
-template <> _LIBCPP_FUNC_VIS void __time_get_storage<_CharT>::init(const ctype<_CharT>&); \
-template <> _LIBCPP_FUNC_VIS __time_get_storage<_CharT>::string_type __time_get_storage<_CharT>::__analyze(char, const ctype<_CharT>&); \
-extern template _LIBCPP_FUNC_VIS time_base::dateorder __time_get_storage<_CharT>::__do_date_order() const; \
-extern template _LIBCPP_FUNC_VIS __time_get_storage<_CharT>::__time_get_storage(const char*); \
-extern template _LIBCPP_FUNC_VIS __time_get_storage<_CharT>::__time_get_storage(const string&); \
-extern template _LIBCPP_FUNC_VIS void __time_get_storage<_CharT>::init(const ctype<_CharT>&); \
-extern template _LIBCPP_FUNC_VIS __time_get_storage<_CharT>::string_type __time_get_storage<_CharT>::__analyze(char, const ctype<_CharT>&); \
-/**/
-
-_LIBCPP_TIME_GET_STORAGE_EXPLICIT_INSTANTIATION(char)
-_LIBCPP_TIME_GET_STORAGE_EXPLICIT_INSTANTIATION(wchar_t)
-#undef _LIBCPP_TIME_GET_STORAGE_EXPLICIT_INSTANTIATION
-
-template <class _CharT, class _InputIterator = istreambuf_iterator<_CharT> >
-class _LIBCPP_TEMPLATE_VIS time_get_byname
-    : public time_get<_CharT, _InputIterator>,
-      private __time_get_storage<_CharT>
-{
-public:
-    typedef time_base::dateorder    dateorder;
-    typedef _InputIterator          iter_type;
-    typedef _CharT                  char_type;
-    typedef basic_string<char_type> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit time_get_byname(const char* __nm, size_t __refs = 0)
-        : time_get<_CharT, _InputIterator>(__refs),
-          __time_get_storage<_CharT>(__nm) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit time_get_byname(const string& __nm, size_t __refs = 0)
-        : time_get<_CharT, _InputIterator>(__refs),
-          __time_get_storage<_CharT>(__nm) {}
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~time_get_byname() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    virtual dateorder do_date_order() const {return this->__do_date_order();}
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    virtual const string_type* __weeks() const  {return this->__weeks_;}
-    _LIBCPP_INLINE_VISIBILITY
-    virtual const string_type* __months() const {return this->__months_;}
-    _LIBCPP_INLINE_VISIBILITY
-    virtual const string_type* __am_pm() const  {return this->__am_pm_;}
-    _LIBCPP_INLINE_VISIBILITY
-    virtual const string_type& __c() const      {return this->__c_;}
-    _LIBCPP_INLINE_VISIBILITY
-    virtual const string_type& __r() const      {return this->__r_;}
-    _LIBCPP_INLINE_VISIBILITY
-    virtual const string_type& __x() const      {return this->__x_;}
-    _LIBCPP_INLINE_VISIBILITY
-    virtual const string_type& __X() const      {return this->__X_;}
-};
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS time_get_byname<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS time_get_byname<wchar_t>)
-
-class _LIBCPP_TYPE_VIS __time_put
-{
-    locale_t __loc_;
-protected:
-    _LIBCPP_INLINE_VISIBILITY __time_put() : __loc_(_LIBCPP_GET_C_LOCALE) {}
-    __time_put(const char* __nm);
-    __time_put(const string& __nm);
-    ~__time_put();
-    void __do_put(char* __nb, char*& __ne, const tm* __tm,
-                  char __fmt, char __mod) const;
-    void __do_put(wchar_t* __wb, wchar_t*& __we, const tm* __tm,
-                  char __fmt, char __mod) const;
-};
-
-template <class _CharT, class _OutputIterator = ostreambuf_iterator<_CharT> >
-class _LIBCPP_TEMPLATE_VIS time_put
-    : public locale::facet,
-      private __time_put
-{
-public:
-    typedef _CharT char_type;
-    typedef _OutputIterator iter_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit time_put(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl, const tm* __tm,
-                  const char_type* __pb, const char_type* __pe) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, ios_base& __iob, char_type __fl,
-                  const tm* __tm, char __fmt, char __mod = 0) const
-    {
-        return do_put(__s, __iob, __fl, __tm, __fmt, __mod);
-    }
-
-    static locale::id id;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~time_put() {}
-    virtual iter_type do_put(iter_type __s, ios_base&, char_type, const tm* __tm,
-                             char __fmt, char __mod) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit time_put(const char* __nm, size_t __refs)
-        : locale::facet(__refs),
-          __time_put(__nm) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit time_put(const string& __nm, size_t __refs)
-        : locale::facet(__refs),
-          __time_put(__nm) {}
-};
-
-template <class _CharT, class _OutputIterator>
-locale::id
-time_put<_CharT, _OutputIterator>::id;
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-time_put<_CharT, _OutputIterator>::put(iter_type __s, ios_base& __iob,
-                                       char_type __fl, const tm* __tm,
-                                       const char_type* __pb,
-                                       const char_type* __pe) const
-{
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__iob.getloc());
-    for (; __pb != __pe; ++__pb)
-    {
-        if (__ct.narrow(*__pb, 0) == '%')
-        {
-            if (++__pb == __pe)
-            {
-                *__s++ = __pb[-1];
-                break;
-            }
-            char __mod = 0;
-            char __fmt = __ct.narrow(*__pb, 0);
-            if (__fmt == 'E' || __fmt == 'O')
-            {
-                if (++__pb == __pe)
-                {
-                    *__s++ = __pb[-2];
-                    *__s++ = __pb[-1];
-                    break;
-                }
-                __mod = __fmt;
-                __fmt = __ct.narrow(*__pb, 0);
-            }
-            __s = do_put(__s, __iob, __fl, __tm, __fmt, __mod);
-        }
-        else
-            *__s++ = *__pb;
-    }
-    return __s;
-}
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-time_put<_CharT, _OutputIterator>::do_put(iter_type __s, ios_base&,
-                                          char_type, const tm* __tm,
-                                          char __fmt, char __mod) const
-{
-    char_type __nar[100];
-    char_type* __nb = __nar;
-    char_type* __ne = __nb + 100;
-    __do_put(__nb, __ne, __tm, __fmt, __mod);
-    return _VSTD::copy(__nb, __ne, __s);
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS time_put<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS time_put<wchar_t>)
-
-template <class _CharT, class _OutputIterator = ostreambuf_iterator<_CharT> >
-class _LIBCPP_TEMPLATE_VIS time_put_byname
-    : public time_put<_CharT, _OutputIterator>
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit time_put_byname(const char* __nm, size_t __refs = 0)
-        : time_put<_CharT, _OutputIterator>(__nm, __refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit time_put_byname(const string& __nm, size_t __refs = 0)
-        : time_put<_CharT, _OutputIterator>(__nm, __refs) {}
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~time_put_byname() {}
-};
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS time_put_byname<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS time_put_byname<wchar_t>)
-
-// money_base
-
-class _LIBCPP_TYPE_VIS money_base
-{
-public:
-    enum part {none, space, symbol, sign, value};
-    struct pattern {char field[4];};
-
-    _LIBCPP_INLINE_VISIBILITY money_base() {}
-};
-
-// moneypunct
-
-template <class _CharT, bool _International = false>
-class _LIBCPP_TEMPLATE_VIS moneypunct
-    : public locale::facet,
-      public money_base
-{
-public:
-    typedef _CharT                  char_type;
-    typedef basic_string<char_type> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit moneypunct(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY char_type   decimal_point() const {return do_decimal_point();}
-    _LIBCPP_INLINE_VISIBILITY char_type   thousands_sep() const {return do_thousands_sep();}
-    _LIBCPP_INLINE_VISIBILITY string      grouping()      const {return do_grouping();}
-    _LIBCPP_INLINE_VISIBILITY string_type curr_symbol()   const {return do_curr_symbol();}
-    _LIBCPP_INLINE_VISIBILITY string_type positive_sign() const {return do_positive_sign();}
-    _LIBCPP_INLINE_VISIBILITY string_type negative_sign() const {return do_negative_sign();}
-    _LIBCPP_INLINE_VISIBILITY int         frac_digits()   const {return do_frac_digits();}
-    _LIBCPP_INLINE_VISIBILITY pattern     pos_format()    const {return do_pos_format();}
-    _LIBCPP_INLINE_VISIBILITY pattern     neg_format()    const {return do_neg_format();}
-
-    static locale::id id;
-    static const bool intl = _International;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~moneypunct() {}
-
-    virtual char_type   do_decimal_point() const {return numeric_limits<char_type>::max();}
-    virtual char_type   do_thousands_sep() const {return numeric_limits<char_type>::max();}
-    virtual string      do_grouping()      const {return string();}
-    virtual string_type do_curr_symbol()   const {return string_type();}
-    virtual string_type do_positive_sign() const {return string_type();}
-    virtual string_type do_negative_sign() const {return string_type(1, '-');}
-    virtual int         do_frac_digits()   const {return 0;}
-    virtual pattern     do_pos_format()    const
-        {pattern __p = {{symbol, sign, none, value}}; return __p;}
-    virtual pattern     do_neg_format()    const
-        {pattern __p = {{symbol, sign, none, value}}; return __p;}
-};
-
-template <class _CharT, bool _International>
-locale::id
-moneypunct<_CharT, _International>::id;
-
-template <class _CharT, bool _International>
-const bool
-moneypunct<_CharT, _International>::intl;
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS moneypunct<char, false>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS moneypunct<char, true>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS moneypunct<wchar_t, false>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS moneypunct<wchar_t, true>)
-
-// moneypunct_byname
-
-template <class _CharT, bool _International = false>
-class _LIBCPP_TEMPLATE_VIS moneypunct_byname
-    : public moneypunct<_CharT, _International>
-{
-public:
-    typedef money_base::pattern  pattern;
-    typedef _CharT                  char_type;
-    typedef basic_string<char_type> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit moneypunct_byname(const char* __nm, size_t __refs = 0)
-        : moneypunct<_CharT, _International>(__refs) {init(__nm);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit moneypunct_byname(const string& __nm, size_t __refs = 0)
-        : moneypunct<_CharT, _International>(__refs) {init(__nm.c_str());}
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~moneypunct_byname() {}
-
-    virtual char_type   do_decimal_point() const {return __decimal_point_;}
-    virtual char_type   do_thousands_sep() const {return __thousands_sep_;}
-    virtual string      do_grouping()      const {return __grouping_;}
-    virtual string_type do_curr_symbol()   const {return __curr_symbol_;}
-    virtual string_type do_positive_sign() const {return __positive_sign_;}
-    virtual string_type do_negative_sign() const {return __negative_sign_;}
-    virtual int         do_frac_digits()   const {return __frac_digits_;}
-    virtual pattern     do_pos_format()    const {return __pos_format_;}
-    virtual pattern     do_neg_format()    const {return __neg_format_;}
-
-private:
-    char_type   __decimal_point_;
-    char_type   __thousands_sep_;
-    string      __grouping_;
-    string_type __curr_symbol_;
-    string_type __positive_sign_;
-    string_type __negative_sign_;
-    int         __frac_digits_;
-    pattern     __pos_format_;
-    pattern     __neg_format_;
-
-    void init(const char*);
-};
-
-template<> _LIBCPP_FUNC_VIS void moneypunct_byname<char, false>::init(const char*);
-template<> _LIBCPP_FUNC_VIS void moneypunct_byname<char, true>::init(const char*);
-template<> _LIBCPP_FUNC_VIS void moneypunct_byname<wchar_t, false>::init(const char*);
-template<> _LIBCPP_FUNC_VIS void moneypunct_byname<wchar_t, true>::init(const char*);
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS moneypunct_byname<char, false>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS moneypunct_byname<char, true>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS moneypunct_byname<wchar_t, false>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS moneypunct_byname<wchar_t, true>)
-
-// money_get
-
-template <class _CharT>
-class __money_get
-{
-protected:
-    typedef _CharT                  char_type;
-    typedef basic_string<char_type> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY __money_get() {}
-
-    static void __gather_info(bool __intl, const locale& __loc,
-                              money_base::pattern& __pat, char_type& __dp,
-                              char_type& __ts, string& __grp,
-                              string_type& __sym, string_type& __psn,
-                              string_type& __nsn, int& __fd);
-};
-
-template <class _CharT>
-void
-__money_get<_CharT>::__gather_info(bool __intl, const locale& __loc,
-                                   money_base::pattern& __pat, char_type& __dp,
-                                   char_type& __ts, string& __grp,
-                                   string_type& __sym, string_type& __psn,
-                                   string_type& __nsn, int& __fd)
-{
-    if (__intl)
-    {
-        const moneypunct<char_type, true>& __mp =
-            use_facet<moneypunct<char_type, true> >(__loc);
-        __pat = __mp.neg_format();
-        __nsn = __mp.negative_sign();
-        __psn = __mp.positive_sign();
-        __dp = __mp.decimal_point();
-        __ts = __mp.thousands_sep();
-        __grp = __mp.grouping();
-        __sym = __mp.curr_symbol();
-        __fd = __mp.frac_digits();
-    }
-    else
-    {
-        const moneypunct<char_type, false>& __mp =
-            use_facet<moneypunct<char_type, false> >(__loc);
-        __pat = __mp.neg_format();
-        __nsn = __mp.negative_sign();
-        __psn = __mp.positive_sign();
-        __dp = __mp.decimal_point();
-        __ts = __mp.thousands_sep();
-        __grp = __mp.grouping();
-        __sym = __mp.curr_symbol();
-        __fd = __mp.frac_digits();
-    }
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __money_get<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __money_get<wchar_t>)
-
-template <class _CharT, class _InputIterator = istreambuf_iterator<_CharT> >
-class _LIBCPP_TEMPLATE_VIS money_get
-    : public locale::facet,
-      private __money_get<_CharT>
-{
-public:
-    typedef _CharT                  char_type;
-    typedef _InputIterator          iter_type;
-    typedef basic_string<char_type> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit money_get(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, bool __intl, ios_base& __iob,
-                  ios_base::iostate& __err, long double& __v) const
-    {
-        return do_get(__b, __e, __intl, __iob, __err, __v);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type get(iter_type __b, iter_type __e, bool __intl, ios_base& __iob,
-                  ios_base::iostate& __err, string_type& __v) const
-    {
-        return do_get(__b, __e, __intl, __iob, __err, __v);
-    }
-
-    static locale::id id;
-
-protected:
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~money_get() {}
-
-    virtual iter_type do_get(iter_type __b, iter_type __e, bool __intl,
-                             ios_base& __iob, ios_base::iostate& __err,
-                             long double& __v) const;
-    virtual iter_type do_get(iter_type __b, iter_type __e, bool __intl,
-                             ios_base& __iob, ios_base::iostate& __err,
-                             string_type& __v) const;
-
-private:
-    static bool __do_get(iter_type& __b, iter_type __e,
-                         bool __intl, const locale& __loc,
-                         ios_base::fmtflags __flags, ios_base::iostate& __err,
-                         bool& __neg, const ctype<char_type>& __ct,
-                         unique_ptr<char_type, void(*)(void*)>& __wb,
-                         char_type*& __wn, char_type* __we);
-};
-
-template <class _CharT, class _InputIterator>
-locale::id
-money_get<_CharT, _InputIterator>::id;
-
-_LIBCPP_FUNC_VIS void __do_nothing(void*);
-
-template <class _Tp>
-_LIBCPP_HIDDEN
-void
-__double_or_nothing(unique_ptr<_Tp, void(*)(void*)>& __b, _Tp*& __n, _Tp*& __e)
-{
-    bool __owns = __b.get_deleter() != __do_nothing;
-    size_t __cur_cap = static_cast<size_t>(__e-__b.get()) * sizeof(_Tp);
-    size_t __new_cap = __cur_cap < numeric_limits<size_t>::max() / 2 ?
-                       2 * __cur_cap : numeric_limits<size_t>::max();
-    if (__new_cap == 0)
-        __new_cap = sizeof(_Tp);
-    size_t __n_off = static_cast<size_t>(__n - __b.get());
-    _Tp* __t = (_Tp*)realloc(__owns ? __b.get() : 0, __new_cap);
-    if (__t == 0)
-        __throw_bad_alloc();
-    if (__owns)
-        __b.release();
-    __b = unique_ptr<_Tp, void(*)(void*)>(__t, free);
-    __new_cap /= sizeof(_Tp);
-    __n = __b.get() + __n_off;
-    __e = __b.get() + __new_cap;
-}
-
-// true == success
-template <class _CharT, class _InputIterator>
-bool
-money_get<_CharT, _InputIterator>::__do_get(iter_type& __b, iter_type __e,
-                                            bool __intl, const locale& __loc,
-                                            ios_base::fmtflags __flags,
-                                            ios_base::iostate& __err,
-                                            bool& __neg,
-                                            const ctype<char_type>& __ct,
-                                            unique_ptr<char_type, void(*)(void*)>& __wb,
-                                            char_type*& __wn, char_type* __we)
-{
-    const unsigned __bz = 100;
-    unsigned __gbuf[__bz];
-    unique_ptr<unsigned, void(*)(void*)> __gb(__gbuf, __do_nothing);
-    unsigned* __gn = __gb.get();
-    unsigned* __ge = __gn + __bz;
-    money_base::pattern __pat;
-    char_type __dp;
-    char_type __ts;
-    string __grp;
-    string_type __sym;
-    string_type __psn;
-    string_type __nsn;
-    // Capture the spaces read into money_base::{space,none} so they
-    // can be compared to initial spaces in __sym.
-    string_type __spaces;
-    int __fd;
-    __money_get<_CharT>::__gather_info(__intl, __loc, __pat, __dp, __ts, __grp,
-                                       __sym, __psn, __nsn, __fd);
-    const string_type* __trailing_sign = 0;
-    __wn = __wb.get();
-    for (unsigned __p = 0; __p < 4 && __b != __e; ++__p)
-    {
-        switch (__pat.field[__p])
-        {
-        case money_base::space:
-            if (__p != 3)
-            {
-                if (__ct.is(ctype_base::space, *__b))
-                    __spaces.push_back(*__b++);
-                else
-                {
-                    __err |= ios_base::failbit;
-                    return false;
-                }
-            }
-            _LIBCPP_FALLTHROUGH();
-        case money_base::none:
-            if (__p != 3)
-            {
-                while (__b != __e && __ct.is(ctype_base::space, *__b))
-                    __spaces.push_back(*__b++);
-            }
-            break;
-        case money_base::sign:
-            if (__psn.size() + __nsn.size() > 0)
-            {
-                if (__psn.size() == 0 || __nsn.size() == 0)
-                {   // sign is optional
-                    if (__psn.size() > 0)
-                    {   // __nsn.size() == 0
-                        if (*__b == __psn[0])
-                        {
-                            ++__b;
-                            if (__psn.size() > 1)
-                                __trailing_sign = &__psn;
-                        }
-                        else
-                            __neg = true;
-                    }
-                    else if (*__b == __nsn[0])  // __nsn.size() > 0 &&  __psn.size() == 0
-                    {
-                        ++__b;
-                        __neg = true;
-                        if (__nsn.size() > 1)
-                            __trailing_sign = &__nsn;
-                    }
-                }
-                else  // sign is required
-                {
-                    if (*__b == __psn[0])
-                    {
-                        ++__b;
-                        if (__psn.size() > 1)
-                            __trailing_sign = &__psn;
-                    }
-                    else if (*__b == __nsn[0])
-                    {
-                        ++__b;
-                        __neg = true;
-                        if (__nsn.size() > 1)
-                            __trailing_sign = &__nsn;
-                    }
-                    else
-                    {
-                        __err |= ios_base::failbit;
-                        return false;
-                    }
-                }
-            }
-            break;
-        case money_base::symbol:
-            {
-            bool __more_needed = __trailing_sign ||
-                                 (__p < 2)       ||
-                                 (__p == 2 && __pat.field[3] != static_cast<char>(money_base::none));
-            bool __sb = (__flags & ios_base::showbase) != 0;
-            if (__sb || __more_needed)
-            {
-                typename string_type::const_iterator __sym_space_end = __sym.begin();
-                if (__p > 0 && (__pat.field[__p - 1] == money_base::none ||
-                                __pat.field[__p - 1] == money_base::space)) {
-                    // Match spaces we've already read against spaces at
-                    // the beginning of __sym.
-                    while (__sym_space_end != __sym.end() &&
-                           __ct.is(ctype_base::space, *__sym_space_end))
-                        ++__sym_space_end;
-                    const size_t __num_spaces = __sym_space_end - __sym.begin();
-                    if (__num_spaces > __spaces.size() ||
-                        !equal(__spaces.end() - __num_spaces, __spaces.end(),
-                               __sym.begin())) {
-                        // No match. Put __sym_space_end back at the
-                        // beginning of __sym, which will prevent a
-                        // match in the next loop.
-                        __sym_space_end = __sym.begin();
-                    }
-                }
-                typename string_type::const_iterator __sym_curr_char = __sym_space_end;
-                while (__sym_curr_char != __sym.end() && __b != __e &&
-                       *__b == *__sym_curr_char) {
-                    ++__b;
-                    ++__sym_curr_char;
-                }
-                if (__sb && __sym_curr_char != __sym.end())
-                {
-                    __err |= ios_base::failbit;
-                    return false;
-                }
-            }
-            }
-            break;
-        case money_base::value:
-            {
-            unsigned __ng = 0;
-            for (; __b != __e; ++__b)
-            {
-                char_type __c = *__b;
-                if (__ct.is(ctype_base::digit, __c))
-                {
-                    if (__wn == __we)
-                        __double_or_nothing(__wb, __wn, __we);
-                    *__wn++ = __c;
-                    ++__ng;
-                }
-                else if (__grp.size() > 0 && __ng > 0 && __c == __ts)
-                {
-                    if (__gn == __ge)
-                        __double_or_nothing(__gb, __gn, __ge);
-                    *__gn++ = __ng;
-                    __ng = 0;
-                }
-                else
-                    break;
-            }
-            if (__gb.get() != __gn && __ng > 0)
-            {
-                if (__gn == __ge)
-                    __double_or_nothing(__gb, __gn, __ge);
-                *__gn++ = __ng;
-            }
-            if (__fd > 0)
-            {
-                if (__b == __e || *__b != __dp)
-                {
-                    __err |= ios_base::failbit;
-                    return false;
-                }
-                for (++__b; __fd > 0; --__fd, ++__b)
-                {
-                    if (__b == __e || !__ct.is(ctype_base::digit, *__b))
-                    {
-                        __err |= ios_base::failbit;
-                        return false;
-                    }
-                    if (__wn == __we)
-                        __double_or_nothing(__wb, __wn, __we);
-                    *__wn++ = *__b;
-                }
-            }
-            if (__wn == __wb.get())
-            {
-                __err |= ios_base::failbit;
-                return false;
-            }
-            }
-            break;
-        }
-    }
-    if (__trailing_sign)
-    {
-        for (unsigned __i = 1; __i < __trailing_sign->size(); ++__i, ++__b)
-        {
-            if (__b == __e || *__b != (*__trailing_sign)[__i])
-            {
-                __err |= ios_base::failbit;
-                return false;
-            }
-        }
-    }
-    if (__gb.get() != __gn)
-    {
-        ios_base::iostate __et = ios_base::goodbit;
-        __check_grouping(__grp, __gb.get(), __gn, __et);
-        if (__et)
-        {
-            __err |= ios_base::failbit;
-            return false;
-        }
-    }
-    return true;
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-money_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
-                                          bool __intl, ios_base& __iob,
-                                          ios_base::iostate& __err,
-                                          long double& __v) const
-{
-    const int __bz = 100;
-    char_type __wbuf[__bz];
-    unique_ptr<char_type, void(*)(void*)> __wb(__wbuf, __do_nothing);
-    char_type* __wn;
-    char_type* __we = __wbuf + __bz;
-    locale __loc = __iob.getloc();
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__loc);
-    bool __neg = false;
-    if (__do_get(__b, __e, __intl, __loc, __iob.flags(), __err, __neg, __ct,
-                 __wb, __wn, __we))
-    {
-        const char __src[] = "0123456789";
-        char_type __atoms[sizeof(__src)-1];
-        __ct.widen(__src, __src + (sizeof(__src)-1), __atoms);
-        char __nbuf[__bz];
-        char* __nc = __nbuf;
-        unique_ptr<char, void(*)(void*)> __h(0, free);
-        if (__wn - __wb.get() > __bz-2)
-        {
-            __h.reset((char*)malloc(static_cast<size_t>(__wn - __wb.get() + 2)));
-            if (__h.get() == 0)
-                __throw_bad_alloc();
-            __nc = __h.get();
-        }
-        if (__neg)
-            *__nc++ = '-';
-        for (const char_type* __w = __wb.get(); __w < __wn; ++__w, ++__nc)
-            *__nc = __src[find(__atoms, _VSTD::end(__atoms), *__w) - __atoms];
-        *__nc = char();
-        if (sscanf(__nbuf, "%Lf", &__v) != 1)
-            __throw_runtime_error("money_get error");
-    }
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-    return __b;
-}
-
-template <class _CharT, class _InputIterator>
-_InputIterator
-money_get<_CharT, _InputIterator>::do_get(iter_type __b, iter_type __e,
-                                          bool __intl, ios_base& __iob,
-                                          ios_base::iostate& __err,
-                                          string_type& __v) const
-{
-    const int __bz = 100;
-    char_type __wbuf[__bz];
-    unique_ptr<char_type, void(*)(void*)> __wb(__wbuf, __do_nothing);
-    char_type* __wn;
-    char_type* __we = __wbuf + __bz;
-    locale __loc = __iob.getloc();
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__loc);
-    bool __neg = false;
-    if (__do_get(__b, __e, __intl, __loc, __iob.flags(), __err, __neg, __ct,
-                 __wb, __wn, __we))
-    {
-        __v.clear();
-        if (__neg)
-            __v.push_back(__ct.widen('-'));
-        char_type __z = __ct.widen('0');
-        char_type* __w;
-        for (__w = __wb.get(); __w < __wn-1; ++__w)
-            if (*__w != __z)
-                break;
-        __v.append(__w, __wn);
-    }
-    if (__b == __e)
-        __err |= ios_base::eofbit;
-    return __b;
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS money_get<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS money_get<wchar_t>)
-
-// money_put
-
-template <class _CharT>
-class __money_put
-{
-protected:
-    typedef _CharT                  char_type;
-    typedef basic_string<char_type> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY __money_put() {}
-
-    static void __gather_info(bool __intl, bool __neg, const locale& __loc,
-                              money_base::pattern& __pat, char_type& __dp,
-                              char_type& __ts, string& __grp,
-                              string_type& __sym, string_type& __sn,
-                              int& __fd);
-    static void __format(char_type* __mb, char_type*& __mi, char_type*& __me,
-                         ios_base::fmtflags __flags,
-                         const char_type* __db, const char_type* __de,
-                         const ctype<char_type>& __ct, bool __neg,
-                         const money_base::pattern& __pat, char_type __dp,
-                         char_type __ts, const string& __grp,
-                         const string_type& __sym, const string_type& __sn,
-                         int __fd);
-};
-
-template <class _CharT>
-void
-__money_put<_CharT>::__gather_info(bool __intl, bool __neg, const locale& __loc,
-                                   money_base::pattern& __pat, char_type& __dp,
-                                   char_type& __ts, string& __grp,
-                                   string_type& __sym, string_type& __sn,
-                                   int& __fd)
-{
-    if (__intl)
-    {
-        const moneypunct<char_type, true>& __mp =
-            use_facet<moneypunct<char_type, true> >(__loc);
-        if (__neg)
-        {
-            __pat = __mp.neg_format();
-            __sn = __mp.negative_sign();
-        }
-        else
-        {
-            __pat = __mp.pos_format();
-            __sn = __mp.positive_sign();
-        }
-        __dp = __mp.decimal_point();
-        __ts = __mp.thousands_sep();
-        __grp = __mp.grouping();
-        __sym = __mp.curr_symbol();
-        __fd = __mp.frac_digits();
-    }
-    else
-    {
-        const moneypunct<char_type, false>& __mp =
-            use_facet<moneypunct<char_type, false> >(__loc);
-        if (__neg)
-        {
-            __pat = __mp.neg_format();
-            __sn = __mp.negative_sign();
-        }
-        else
-        {
-            __pat = __mp.pos_format();
-            __sn = __mp.positive_sign();
-        }
-        __dp = __mp.decimal_point();
-        __ts = __mp.thousands_sep();
-        __grp = __mp.grouping();
-        __sym = __mp.curr_symbol();
-        __fd = __mp.frac_digits();
-    }
-}
-
-template <class _CharT>
-void
-__money_put<_CharT>::__format(char_type* __mb, char_type*& __mi, char_type*& __me,
-                              ios_base::fmtflags __flags,
-                              const char_type* __db, const char_type* __de,
-                              const ctype<char_type>& __ct, bool __neg,
-                              const money_base::pattern& __pat, char_type __dp,
-                              char_type __ts, const string& __grp,
-                              const string_type& __sym, const string_type& __sn,
-                              int __fd)
-{
-    __me = __mb;
-    for (unsigned __p = 0; __p < 4; ++__p)
-    {
-        switch (__pat.field[__p])
-        {
-        case money_base::none:
-            __mi = __me;
-            break;
-        case money_base::space:
-            __mi = __me;
-            *__me++ = __ct.widen(' ');
-            break;
-        case money_base::sign:
-            if (!__sn.empty())
-                *__me++ = __sn[0];
-            break;
-        case money_base::symbol:
-            if (!__sym.empty() && (__flags & ios_base::showbase))
-                __me = _VSTD::copy(__sym.begin(), __sym.end(), __me);
-            break;
-        case money_base::value:
-            {
-            // remember start of value so we can reverse it
-            char_type* __t = __me;
-            // find beginning of digits
-            if (__neg)
-                ++__db;
-            // find end of digits
-            const char_type* __d;
-            for (__d = __db; __d < __de; ++__d)
-                if (!__ct.is(ctype_base::digit, *__d))
-                    break;
-            // print fractional part
-            if (__fd > 0)
-            {
-                int __f;
-                for (__f = __fd; __d > __db && __f > 0; --__f)
-                    *__me++ = *--__d;
-                char_type __z = __f > 0 ? __ct.widen('0') : char_type();
-                for (; __f > 0; --__f)
-                    *__me++ = __z;
-                *__me++ = __dp;
-            }
-            // print units part
-            if (__d == __db)
-            {
-                *__me++ = __ct.widen('0');
-            }
-            else
-            {
-                unsigned __ng = 0;
-                unsigned __ig = 0;
-                unsigned __gl = __grp.empty() ? numeric_limits<unsigned>::max()
-                                              : static_cast<unsigned>(__grp[__ig]);
-                while (__d != __db)
-                {
-                    if (__ng == __gl)
-                    {
-                        *__me++ = __ts;
-                        __ng = 0;
-                        if (++__ig < __grp.size())
-                            __gl = __grp[__ig] == numeric_limits<char>::max() ?
-                                        numeric_limits<unsigned>::max() :
-                                        static_cast<unsigned>(__grp[__ig]);
-                    }
-                    *__me++ = *--__d;
-                    ++__ng;
-                }
-            }
-            // reverse it
-            reverse(__t, __me);
-            }
-            break;
-        }
-    }
-    // print rest of sign, if any
-    if (__sn.size() > 1)
-        __me = _VSTD::copy(__sn.begin()+1, __sn.end(), __me);
-    // set alignment
-    if ((__flags & ios_base::adjustfield) == ios_base::left)
-        __mi = __me;
-    else if ((__flags & ios_base::adjustfield) != ios_base::internal)
-        __mi = __mb;
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __money_put<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __money_put<wchar_t>)
-
-template <class _CharT, class _OutputIterator = ostreambuf_iterator<_CharT> >
-class _LIBCPP_TEMPLATE_VIS money_put
-    : public locale::facet,
-      private __money_put<_CharT>
-{
-public:
-    typedef _CharT                  char_type;
-    typedef _OutputIterator         iter_type;
-    typedef basic_string<char_type> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit money_put(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, bool __intl, ios_base& __iob, char_type __fl,
-                  long double __units) const
-    {
-        return do_put(__s, __intl, __iob, __fl, __units);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iter_type put(iter_type __s, bool __intl, ios_base& __iob, char_type __fl,
-                  const string_type& __digits) const
-    {
-        return do_put(__s, __intl, __iob, __fl, __digits);
-    }
-
-    static locale::id id;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~money_put() {}
-
-    virtual iter_type do_put(iter_type __s, bool __intl, ios_base& __iob,
-                             char_type __fl, long double __units) const;
-    virtual iter_type do_put(iter_type __s, bool __intl, ios_base& __iob,
-                             char_type __fl, const string_type& __digits) const;
-};
-
-template <class _CharT, class _OutputIterator>
-locale::id
-money_put<_CharT, _OutputIterator>::id;
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-money_put<_CharT, _OutputIterator>::do_put(iter_type __s, bool __intl,
-                                           ios_base& __iob, char_type __fl,
-                                           long double __units) const
-{
-    // convert to char
-    const size_t __bs = 100;
-    char __buf[__bs];
-    char* __bb = __buf;
-    char_type __digits[__bs];
-    char_type* __db = __digits;
-    size_t __n = static_cast<size_t>(snprintf(__bb, __bs, "%.0Lf", __units));
-    unique_ptr<char, void(*)(void*)> __hn(0, free);
-    unique_ptr<char_type, void(*)(void*)> __hd(0, free);
-    // secure memory for digit storage
-    if (__n > __bs-1)
-    {
-        __n = static_cast<size_t>(__libcpp_asprintf_l(&__bb, _LIBCPP_GET_C_LOCALE, "%.0Lf", __units));
-        if (__n == -1)
-            __throw_bad_alloc();
-        __hn.reset(__bb);
-        __hd.reset((char_type*)malloc(__n * sizeof(char_type)));
-        if (__hd == nullptr)
-            __throw_bad_alloc();
-        __db = __hd.get();
-    }
-    // gather info
-    locale __loc = __iob.getloc();
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__loc);
-    __ct.widen(__bb, __bb + __n, __db);
-    bool __neg = __n > 0 && __bb[0] == '-';
-    money_base::pattern __pat;
-    char_type __dp;
-    char_type __ts;
-    string __grp;
-    string_type __sym;
-    string_type __sn;
-    int __fd;
-    this->__gather_info(__intl, __neg, __loc, __pat, __dp, __ts, __grp, __sym, __sn, __fd);
-    // secure memory for formatting
-    char_type __mbuf[__bs];
-    char_type* __mb = __mbuf;
-    unique_ptr<char_type, void(*)(void*)> __hw(0, free);
-    size_t __exn = static_cast<int>(__n) > __fd ?
-                   (__n - static_cast<size_t>(__fd)) * 2 + __sn.size() +
-                    __sym.size() + static_cast<size_t>(__fd) + 1
-                 : __sn.size() + __sym.size() + static_cast<size_t>(__fd) + 2;
-    if (__exn > __bs)
-    {
-        __hw.reset((char_type*)malloc(__exn * sizeof(char_type)));
-        __mb = __hw.get();
-        if (__mb == 0)
-            __throw_bad_alloc();
-    }
-    // format
-    char_type* __mi;
-    char_type* __me;
-    this->__format(__mb, __mi, __me, __iob.flags(),
-                   __db, __db + __n, __ct,
-                   __neg, __pat, __dp, __ts, __grp, __sym, __sn, __fd);
-    return __pad_and_output(__s, __mb, __mi, __me, __iob, __fl);
-}
-
-template <class _CharT, class _OutputIterator>
-_OutputIterator
-money_put<_CharT, _OutputIterator>::do_put(iter_type __s, bool __intl,
-                                           ios_base& __iob, char_type __fl,
-                                           const string_type& __digits) const
-{
-    // gather info
-    locale __loc = __iob.getloc();
-    const ctype<char_type>& __ct = use_facet<ctype<char_type> >(__loc);
-    bool __neg = __digits.size() > 0 && __digits[0] == __ct.widen('-');
-    money_base::pattern __pat;
-    char_type __dp;
-    char_type __ts;
-    string __grp;
-    string_type __sym;
-    string_type __sn;
-    int __fd;
-    this->__gather_info(__intl, __neg, __loc, __pat, __dp, __ts, __grp, __sym, __sn, __fd);
-    // secure memory for formatting
-    char_type __mbuf[100];
-    char_type* __mb = __mbuf;
-    unique_ptr<char_type, void(*)(void*)> __h(0, free);
-    size_t __exn = static_cast<int>(__digits.size()) > __fd ?
-                   (__digits.size() - static_cast<size_t>(__fd)) * 2 +
-                    __sn.size() + __sym.size() + static_cast<size_t>(__fd) + 1
-                 : __sn.size() + __sym.size() + static_cast<size_t>(__fd) + 2;
-    if (__exn > 100)
-    {
-        __h.reset((char_type*)malloc(__exn * sizeof(char_type)));
-        __mb = __h.get();
-        if (__mb == 0)
-            __throw_bad_alloc();
-    }
-    // format
-    char_type* __mi;
-    char_type* __me;
-    this->__format(__mb, __mi, __me, __iob.flags(),
-                   __digits.data(), __digits.data() + __digits.size(), __ct,
-                   __neg, __pat, __dp, __ts, __grp, __sym, __sn, __fd);
-    return __pad_and_output(__s, __mb, __mi, __me, __iob, __fl);
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS money_put<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS money_put<wchar_t>)
-
-// messages
-
-class _LIBCPP_TYPE_VIS messages_base
-{
-public:
-    typedef ptrdiff_t catalog;
-
-    _LIBCPP_INLINE_VISIBILITY messages_base() {}
-};
-
-template <class _CharT>
-class _LIBCPP_TEMPLATE_VIS messages
-    : public locale::facet,
-      public messages_base
-{
-public:
-    typedef _CharT               char_type;
-    typedef basic_string<_CharT> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit messages(size_t __refs = 0)
-        : locale::facet(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    catalog open(const basic_string<char>& __nm, const locale& __loc) const
-    {
-        return do_open(__nm, __loc);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    string_type get(catalog __c, int __set, int __msgid,
-                    const string_type& __dflt) const
-    {
-        return do_get(__c, __set, __msgid, __dflt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void close(catalog __c) const
-    {
-        do_close(__c);
-    }
-
-    static locale::id id;
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~messages() {}
-
-    virtual catalog do_open(const basic_string<char>&, const locale&) const;
-    virtual string_type do_get(catalog, int __set, int __msgid,
-                               const string_type& __dflt) const;
-    virtual void do_close(catalog) const;
-};
-
-template <class _CharT>
-locale::id
-messages<_CharT>::id;
-
-template <class _CharT>
-typename messages<_CharT>::catalog
-messages<_CharT>::do_open(const basic_string<char>& __nm, const locale&) const
-{
-#ifdef _LIBCPP_HAS_CATOPEN
-    catalog __cat = (catalog)catopen(__nm.c_str(), NL_CAT_LOCALE);
-    if (__cat != -1)
-        __cat = static_cast<catalog>((static_cast<size_t>(__cat) >> 1));
-    return __cat;
-#else // !_LIBCPP_HAS_CATOPEN
-    _LIBCPP_UNUSED_VAR(__nm);
-    return -1;
-#endif // _LIBCPP_HAS_CATOPEN
-}
-
-template <class _CharT>
-typename messages<_CharT>::string_type
-messages<_CharT>::do_get(catalog __c, int __set, int __msgid,
-                         const string_type& __dflt) const
-{
-#ifdef _LIBCPP_HAS_CATOPEN
-    string __ndflt;
-    __narrow_to_utf8<sizeof(char_type)*__CHAR_BIT__>()(back_inserter(__ndflt),
-                                                       __dflt.c_str(),
-                                                       __dflt.c_str() + __dflt.size());
-    if (__c != -1)
-        __c <<= 1;
-    nl_catd __cat = (nl_catd)__c;
-    char* __n = catgets(__cat, __set, __msgid, __ndflt.c_str());
-    string_type __w;
-    __widen_from_utf8<sizeof(char_type)*__CHAR_BIT__>()(back_inserter(__w),
-                                                        __n, __n + strlen(__n));
-    return __w;
-#else // !_LIBCPP_HAS_CATOPEN
-    _LIBCPP_UNUSED_VAR(__c);
-    _LIBCPP_UNUSED_VAR(__set);
-    _LIBCPP_UNUSED_VAR(__msgid);
-    return __dflt;
-#endif // _LIBCPP_HAS_CATOPEN
-}
-
-template <class _CharT>
-void
-messages<_CharT>::do_close(catalog __c) const
-{
-#ifdef _LIBCPP_HAS_CATOPEN
-    if (__c != -1)
-        __c <<= 1;
-    nl_catd __cat = (nl_catd)__c;
-    catclose(__cat);
-#else // !_LIBCPP_HAS_CATOPEN
-    _LIBCPP_UNUSED_VAR(__c);
-#endif // _LIBCPP_HAS_CATOPEN
-}
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS messages<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS messages<wchar_t>)
-
-template <class _CharT>
-class _LIBCPP_TEMPLATE_VIS messages_byname
-    : public messages<_CharT>
-{
-public:
-    typedef messages_base::catalog catalog;
-    typedef basic_string<_CharT> string_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit messages_byname(const char*, size_t __refs = 0)
-        : messages<_CharT>(__refs) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit messages_byname(const string&, size_t __refs = 0)
-        : messages<_CharT>(__refs) {}
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    ~messages_byname() {}
-};
-
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS messages_byname<char>)
-_LIBCPP_EXTERN_TEMPLATE2(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS messages_byname<wchar_t>)
-
-template<class _Codecvt, class _Elem = wchar_t,
-         class _Wide_alloc = allocator<_Elem>,
-         class _Byte_alloc = allocator<char> >
-class _LIBCPP_TEMPLATE_VIS wstring_convert
-{
-public:
-    typedef basic_string<char, char_traits<char>, _Byte_alloc>   byte_string;
-    typedef basic_string<_Elem, char_traits<_Elem>, _Wide_alloc> wide_string;
-    typedef typename _Codecvt::state_type                        state_type;
-    typedef typename wide_string::traits_type::int_type          int_type;
-
-private:
-    byte_string __byte_err_string_;
-    wide_string __wide_err_string_;
-    _Codecvt* __cvtptr_;
-    state_type __cvtstate_;
-    size_t __cvtcount_;
-
-    wstring_convert(const wstring_convert& __wc);
-    wstring_convert& operator=(const wstring_convert& __wc);
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_EXPLICIT_AFTER_CXX11 wstring_convert(_Codecvt* __pcvt = new _Codecvt);
-    _LIBCPP_INLINE_VISIBILITY
-    wstring_convert(_Codecvt* __pcvt, state_type __state);
-    _LIBCPP_EXPLICIT_AFTER_CXX11 wstring_convert(const byte_string& __byte_err,
-                    const wide_string& __wide_err = wide_string());
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    wstring_convert(wstring_convert&& __wc);
-#endif
-    ~wstring_convert();
-
-    _LIBCPP_INLINE_VISIBILITY
-    wide_string from_bytes(char __byte)
-        {return from_bytes(&__byte, &__byte+1);}
-    _LIBCPP_INLINE_VISIBILITY
-    wide_string from_bytes(const char* __ptr)
-        {return from_bytes(__ptr, __ptr + char_traits<char>::length(__ptr));}
-    _LIBCPP_INLINE_VISIBILITY
-    wide_string from_bytes(const byte_string& __str)
-        {return from_bytes(__str.data(), __str.data() + __str.size());}
-    wide_string from_bytes(const char* __first, const char* __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    byte_string to_bytes(_Elem __wchar)
-        {return to_bytes(&__wchar, &__wchar+1);}
-    _LIBCPP_INLINE_VISIBILITY
-    byte_string to_bytes(const _Elem* __wptr)
-        {return to_bytes(__wptr, __wptr + char_traits<_Elem>::length(__wptr));}
-    _LIBCPP_INLINE_VISIBILITY
-    byte_string to_bytes(const wide_string& __wstr)
-        {return to_bytes(__wstr.data(), __wstr.data() + __wstr.size());}
-    byte_string to_bytes(const _Elem* __first, const _Elem* __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t converted() const _NOEXCEPT {return __cvtcount_;}
-    _LIBCPP_INLINE_VISIBILITY
-    state_type state() const {return __cvtstate_;}
-};
-
-template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
-inline
-wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
-    wstring_convert(_Codecvt* __pcvt)
-        : __cvtptr_(__pcvt), __cvtstate_(), __cvtcount_(0)
-{
-}
-
-template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
-inline
-wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
-    wstring_convert(_Codecvt* __pcvt, state_type __state)
-        : __cvtptr_(__pcvt), __cvtstate_(__state), __cvtcount_(0)
-{
-}
-
-template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
-wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
-    wstring_convert(const byte_string& __byte_err, const wide_string& __wide_err)
-        : __byte_err_string_(__byte_err), __wide_err_string_(__wide_err),
-          __cvtstate_(), __cvtcount_(0)
-{
-    __cvtptr_ = new _Codecvt;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
-inline
-wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
-    wstring_convert(wstring_convert&& __wc)
-        : __byte_err_string_(_VSTD::move(__wc.__byte_err_string_)),
-          __wide_err_string_(_VSTD::move(__wc.__wide_err_string_)),
-          __cvtptr_(__wc.__cvtptr_),
-          __cvtstate_(__wc.__cvtstate_), __cvtcount_(__wc.__cvtcount_)
-{
-    __wc.__cvtptr_ = nullptr;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
-wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::~wstring_convert()
-{
-    delete __cvtptr_;
-}
-
-template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
-typename wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::wide_string
-wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
-    from_bytes(const char* __frm, const char* __frm_end)
-{
-    __cvtcount_ = 0;
-    if (__cvtptr_ != nullptr)
-    {
-        wide_string __ws(2*(__frm_end - __frm), _Elem());
-        if (__frm != __frm_end)
-            __ws.resize(__ws.capacity());
-        codecvt_base::result __r = codecvt_base::ok;
-        state_type __st = __cvtstate_;
-        if (__frm != __frm_end)
-        {
-            _Elem* __to = &__ws[0];
-            _Elem* __to_end = __to + __ws.size();
-            const char* __frm_nxt;
-            do
-            {
-                _Elem* __to_nxt;
-                __r = __cvtptr_->in(__st, __frm, __frm_end, __frm_nxt,
-                                          __to, __to_end, __to_nxt);
-                __cvtcount_ += __frm_nxt - __frm;
-                if (__frm_nxt == __frm)
-                {
-                    __r = codecvt_base::error;
-                }
-                else if (__r == codecvt_base::noconv)
-                {
-                    __ws.resize(__to - &__ws[0]);
-                    // This only gets executed if _Elem is char
-                    __ws.append((const _Elem*)__frm, (const _Elem*)__frm_end);
-                    __frm = __frm_nxt;
-                    __r = codecvt_base::ok;
-                }
-                else if (__r == codecvt_base::ok)
-                {
-                    __ws.resize(__to_nxt - &__ws[0]);
-                    __frm = __frm_nxt;
-                }
-                else if (__r == codecvt_base::partial)
-                {
-                    ptrdiff_t __s = __to_nxt - &__ws[0];
-                    __ws.resize(2 * __s);
-                    __to = &__ws[0] + __s;
-                    __to_end = &__ws[0] + __ws.size();
-                    __frm = __frm_nxt;
-                }
-            } while (__r == codecvt_base::partial && __frm_nxt < __frm_end);
-        }
-        if (__r == codecvt_base::ok)
-            return __ws;
-    }
-
-    if (__wide_err_string_.empty())
-        __throw_range_error("wstring_convert: from_bytes error");
-
-    return __wide_err_string_;
-}
-
-template<class _Codecvt, class _Elem, class _Wide_alloc, class _Byte_alloc>
-typename wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::byte_string
-wstring_convert<_Codecvt, _Elem, _Wide_alloc, _Byte_alloc>::
-    to_bytes(const _Elem* __frm, const _Elem* __frm_end)
-{
-    __cvtcount_ = 0;
-    if (__cvtptr_ != nullptr)
-    {
-        byte_string __bs(2*(__frm_end - __frm), char());
-        if (__frm != __frm_end)
-            __bs.resize(__bs.capacity());
-        codecvt_base::result __r = codecvt_base::ok;
-        state_type __st = __cvtstate_;
-        if (__frm != __frm_end)
-        {
-            char* __to = &__bs[0];
-            char* __to_end = __to + __bs.size();
-            const _Elem* __frm_nxt;
-            do
-            {
-                char* __to_nxt;
-                __r = __cvtptr_->out(__st, __frm, __frm_end, __frm_nxt,
-                                           __to, __to_end, __to_nxt);
-                __cvtcount_ += __frm_nxt - __frm;
-                if (__frm_nxt == __frm)
-                {
-                    __r = codecvt_base::error;
-                }
-                else if (__r == codecvt_base::noconv)
-                {
-                    __bs.resize(__to - &__bs[0]);
-                    // This only gets executed if _Elem is char
-                    __bs.append((const char*)__frm, (const char*)__frm_end);
-                    __frm = __frm_nxt;
-                    __r = codecvt_base::ok;
-                }
-                else if (__r == codecvt_base::ok)
-                {
-                    __bs.resize(__to_nxt - &__bs[0]);
-                    __frm = __frm_nxt;
-                }
-                else if (__r == codecvt_base::partial)
-                {
-                    ptrdiff_t __s = __to_nxt - &__bs[0];
-                    __bs.resize(2 * __s);
-                    __to = &__bs[0] + __s;
-                    __to_end = &__bs[0] + __bs.size();
-                    __frm = __frm_nxt;
-                }
-            } while (__r == codecvt_base::partial && __frm_nxt < __frm_end);
-        }
-        if (__r == codecvt_base::ok)
-        {
-            size_t __s = __bs.size();
-            __bs.resize(__bs.capacity());
-            char* __to = &__bs[0] + __s;
-            char* __to_end = __to + __bs.size();
-            do
-            {
-                char* __to_nxt;
-                __r = __cvtptr_->unshift(__st, __to, __to_end, __to_nxt);
-                if (__r == codecvt_base::noconv)
-                {
-                    __bs.resize(__to - &__bs[0]);
-                    __r = codecvt_base::ok;
-                }
-                else if (__r == codecvt_base::ok)
-                {
-                    __bs.resize(__to_nxt - &__bs[0]);
-                }
-                else if (__r == codecvt_base::partial)
-                {
-                    ptrdiff_t __sp = __to_nxt - &__bs[0];
-                    __bs.resize(2 * __sp);
-                    __to = &__bs[0] + __sp;
-                    __to_end = &__bs[0] + __bs.size();
-                }
-            } while (__r == codecvt_base::partial);
-            if (__r == codecvt_base::ok)
-                return __bs;
-        }
-    }
-
-    if (__byte_err_string_.empty())
-        __throw_range_error("wstring_convert: to_bytes error");
-
-    return __byte_err_string_;
-}
-
-template <class _Codecvt, class _Elem = wchar_t, class _Tr = char_traits<_Elem> >
-class _LIBCPP_TEMPLATE_VIS wbuffer_convert
-    : public basic_streambuf<_Elem, _Tr>
-{
-public:
-    // types:
-    typedef _Elem                          char_type;
-    typedef _Tr                            traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-    typedef typename _Codecvt::state_type  state_type;
-
-private:
-    char*       __extbuf_;
-    const char* __extbufnext_;
-    const char* __extbufend_;
-    char __extbuf_min_[8];
-    size_t __ebs_;
-    char_type* __intbuf_;
-    size_t __ibs_;
-    streambuf* __bufptr_;
-    _Codecvt* __cv_;
-    state_type __st_;
-    ios_base::openmode __cm_;
-    bool __owns_eb_;
-    bool __owns_ib_;
-    bool __always_noconv_;
-
-    wbuffer_convert(const wbuffer_convert&);
-    wbuffer_convert& operator=(const wbuffer_convert&);
-public:
-    _LIBCPP_EXPLICIT_AFTER_CXX11 wbuffer_convert(streambuf* __bytebuf = 0, 
-            _Codecvt* __pcvt = new _Codecvt, state_type __state = state_type());
-    ~wbuffer_convert();
-
-    _LIBCPP_INLINE_VISIBILITY
-    streambuf* rdbuf() const {return __bufptr_;}
-    _LIBCPP_INLINE_VISIBILITY
-    streambuf* rdbuf(streambuf* __bytebuf)
-    {
-        streambuf* __r = __bufptr_;
-        __bufptr_ = __bytebuf;
-        return __r;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    state_type state() const {return __st_;}
-
-protected:
-    virtual int_type underflow();
-    virtual int_type pbackfail(int_type __c = traits_type::eof());
-    virtual int_type overflow (int_type __c = traits_type::eof());
-    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type* __s,
-                                                            streamsize __n);
-    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way,
-                             ios_base::openmode __wch = ios_base::in | ios_base::out);
-    virtual pos_type seekpos(pos_type __sp,
-                             ios_base::openmode __wch = ios_base::in | ios_base::out);
-    virtual int sync();
-
-private:
-    bool __read_mode();
-    void __write_mode();
-    wbuffer_convert* __close();
-};
-
-template <class _Codecvt, class _Elem, class _Tr>
-wbuffer_convert<_Codecvt, _Elem, _Tr>::
-    wbuffer_convert(streambuf* __bytebuf, _Codecvt* __pcvt, state_type __state)
-    : __extbuf_(0),
-      __extbufnext_(0),
-      __extbufend_(0),
-      __ebs_(0),
-      __intbuf_(0),
-      __ibs_(0),
-      __bufptr_(__bytebuf),
-      __cv_(__pcvt),
-      __st_(__state),
-      __cm_(0),
-      __owns_eb_(false),
-      __owns_ib_(false),
-      __always_noconv_(__cv_ ? __cv_->always_noconv() : false)
-{
-    setbuf(0, 4096);
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-wbuffer_convert<_Codecvt, _Elem, _Tr>::~wbuffer_convert()
-{
-    __close();
-    delete __cv_;
-    if (__owns_eb_)
-        delete [] __extbuf_;
-    if (__owns_ib_)
-        delete [] __intbuf_;
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-typename wbuffer_convert<_Codecvt, _Elem, _Tr>::int_type
-wbuffer_convert<_Codecvt, _Elem, _Tr>::underflow()
-{
-    if (__cv_ == 0 || __bufptr_ == 0)
-        return traits_type::eof();
-    bool __initial = __read_mode();
-    char_type __1buf;
-    if (this->gptr() == 0)
-        this->setg(&__1buf, &__1buf+1, &__1buf+1);
-    const size_t __unget_sz = __initial ? 0 : min<size_t>((this->egptr() - this->eback()) / 2, 4);
-    int_type __c = traits_type::eof();
-    if (this->gptr() == this->egptr())
-    {
-        memmove(this->eback(), this->egptr() - __unget_sz, __unget_sz * sizeof(char_type));
-        if (__always_noconv_)
-        {
-            streamsize __nmemb = static_cast<streamsize>(this->egptr() - this->eback() - __unget_sz);
-            __nmemb = __bufptr_->sgetn((char*)this->eback() + __unget_sz, __nmemb);
-            if (__nmemb != 0)
-            {
-                this->setg(this->eback(),
-                           this->eback() + __unget_sz,
-                           this->eback() + __unget_sz + __nmemb);
-                __c = *this->gptr();
-            }
-        }
-        else
-        {
-             _LIBCPP_ASSERT(!(__extbufnext_ == NULL && (__extbufend_ != __extbufnext_)), "underflow moving from NULL" );
-             if (__extbufend_ != __extbufnext_)
-                memmove(__extbuf_, __extbufnext_, __extbufend_ - __extbufnext_);
-            __extbufnext_ = __extbuf_ + (__extbufend_ - __extbufnext_);
-            __extbufend_ = __extbuf_ + (__extbuf_ == __extbuf_min_ ? sizeof(__extbuf_min_) : __ebs_);
-            streamsize __nmemb = _VSTD::min(static_cast<streamsize>(this->egptr() - this->eback() - __unget_sz),
-                                 static_cast<streamsize>(__extbufend_ - __extbufnext_));
-            codecvt_base::result __r;
-            // FIXME: Do we ever need to restore the state here?
-            //state_type __svs = __st_;
-            streamsize __nr = __bufptr_->sgetn(const_cast<char*>(__extbufnext_), __nmemb);
-            if (__nr != 0)
-            {
-                __extbufend_ = __extbufnext_ + __nr;
-                char_type*  __inext;
-                __r = __cv_->in(__st_, __extbuf_, __extbufend_, __extbufnext_,
-                                       this->eback() + __unget_sz,
-                                       this->egptr(), __inext);
-                if (__r == codecvt_base::noconv)
-                {
-                    this->setg((char_type*)__extbuf_, (char_type*)__extbuf_, 
-                               (char_type*) const_cast<char *>(__extbufend_));
-                    __c = *this->gptr();
-                }
-                else if (__inext != this->eback() + __unget_sz)
-                {
-                    this->setg(this->eback(), this->eback() + __unget_sz, __inext);
-                    __c = *this->gptr();
-                }
-            }
-        }
-    }
-    else
-        __c = *this->gptr();
-    if (this->eback() == &__1buf)
-        this->setg(0, 0, 0);
-    return __c;
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-typename wbuffer_convert<_Codecvt, _Elem, _Tr>::int_type
-wbuffer_convert<_Codecvt, _Elem, _Tr>::pbackfail(int_type __c)
-{
-    if (__cv_ != 0 && __bufptr_ != 0 && this->eback() < this->gptr())
-    {
-        if (traits_type::eq_int_type(__c, traits_type::eof()))
-        {
-            this->gbump(-1);
-            return traits_type::not_eof(__c);
-        }
-        if (traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1]))
-        {
-            this->gbump(-1);
-            *this->gptr() = traits_type::to_char_type(__c);
-            return __c;
-        }
-    }
-    return traits_type::eof();
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-typename wbuffer_convert<_Codecvt, _Elem, _Tr>::int_type
-wbuffer_convert<_Codecvt, _Elem, _Tr>::overflow(int_type __c)
-{
-    if (__cv_ == 0 || __bufptr_ == 0)
-        return traits_type::eof();
-    __write_mode();
-    char_type __1buf;
-    char_type* __pb_save = this->pbase();
-    char_type* __epb_save = this->epptr();
-    if (!traits_type::eq_int_type(__c, traits_type::eof()))
-    {
-        if (this->pptr() == 0)
-            this->setp(&__1buf, &__1buf+1);
-        *this->pptr() = traits_type::to_char_type(__c);
-        this->pbump(1);
-    }
-    if (this->pptr() != this->pbase())
-    {
-        if (__always_noconv_)
-        {
-            streamsize __nmemb = static_cast<streamsize>(this->pptr() - this->pbase());
-            if (__bufptr_->sputn((const char*)this->pbase(), __nmemb) != __nmemb)
-                return traits_type::eof();
-        }
-        else
-        {
-            char* __extbe = __extbuf_;
-            codecvt_base::result __r;
-            do
-            {
-                const char_type* __e;
-                __r = __cv_->out(__st_, this->pbase(), this->pptr(), __e,
-                                        __extbuf_, __extbuf_ + __ebs_, __extbe);
-                if (__e == this->pbase())
-                    return traits_type::eof();
-                if (__r == codecvt_base::noconv)
-                {
-                    streamsize __nmemb = static_cast<size_t>(this->pptr() - this->pbase());
-                    if (__bufptr_->sputn((const char*)this->pbase(), __nmemb) != __nmemb)
-                        return traits_type::eof();
-                }
-                else if (__r == codecvt_base::ok || __r == codecvt_base::partial)
-                {
-                    streamsize __nmemb = static_cast<size_t>(__extbe - __extbuf_);
-                    if (__bufptr_->sputn(__extbuf_, __nmemb) != __nmemb)
-                        return traits_type::eof();
-                    if (__r == codecvt_base::partial)
-                    {
-                        this->setp(const_cast<char_type *>(__e), this->pptr());
-                        this->__pbump(this->epptr() - this->pbase());
-                    }
-                }
-                else
-                    return traits_type::eof();
-            } while (__r == codecvt_base::partial);
-        }
-        this->setp(__pb_save, __epb_save);
-    }
-    return traits_type::not_eof(__c);
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-basic_streambuf<_Elem, _Tr>*
-wbuffer_convert<_Codecvt, _Elem, _Tr>::setbuf(char_type* __s, streamsize __n)
-{
-    this->setg(0, 0, 0);
-    this->setp(0, 0);
-    if (__owns_eb_)
-        delete [] __extbuf_;
-    if (__owns_ib_)
-        delete [] __intbuf_;
-    __ebs_ = __n;
-    if (__ebs_ > sizeof(__extbuf_min_))
-    {
-        if (__always_noconv_ && __s)
-        {
-            __extbuf_ = (char*)__s;
-            __owns_eb_ = false;
-        }
-        else
-        {
-            __extbuf_ = new char[__ebs_];
-            __owns_eb_ = true;
-        }
-    }
-    else
-    {
-        __extbuf_ = __extbuf_min_;
-        __ebs_ = sizeof(__extbuf_min_);
-        __owns_eb_ = false;
-    }
-    if (!__always_noconv_)
-    {
-        __ibs_ = max<streamsize>(__n, sizeof(__extbuf_min_));
-        if (__s && __ibs_ >= sizeof(__extbuf_min_))
-        {
-            __intbuf_ = __s;
-            __owns_ib_ = false;
-        }
-        else
-        {
-            __intbuf_ = new char_type[__ibs_];
-            __owns_ib_ = true;
-        }
-    }
-    else
-    {
-        __ibs_ = 0;
-        __intbuf_ = 0;
-        __owns_ib_ = false;
-    }
-    return this;
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-typename wbuffer_convert<_Codecvt, _Elem, _Tr>::pos_type
-wbuffer_convert<_Codecvt, _Elem, _Tr>::seekoff(off_type __off, ios_base::seekdir __way,
-                                        ios_base::openmode __om)
-{
-    int __width = __cv_->encoding();
-    if (__cv_ == 0 || __bufptr_ == 0 || (__width <= 0 && __off != 0) || sync())
-        return pos_type(off_type(-1));
-    // __width > 0 || __off == 0, now check __way
-    if (__way != ios_base::beg && __way != ios_base::cur && __way != ios_base::end)
-        return pos_type(off_type(-1));
-    pos_type __r = __bufptr_->pubseekoff(__width * __off, __way, __om);
-    __r.state(__st_);
-    return __r;
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-typename wbuffer_convert<_Codecvt, _Elem, _Tr>::pos_type
-wbuffer_convert<_Codecvt, _Elem, _Tr>::seekpos(pos_type __sp, ios_base::openmode __wch)
-{
-    if (__cv_ == 0 || __bufptr_ == 0 || sync())
-        return pos_type(off_type(-1));
-    if (__bufptr_->pubseekpos(__sp, __wch) == pos_type(off_type(-1)))
-        return pos_type(off_type(-1));
-    return __sp;
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-int
-wbuffer_convert<_Codecvt, _Elem, _Tr>::sync()
-{
-    if (__cv_ == 0 || __bufptr_ == 0)
-        return 0;
-    if (__cm_ & ios_base::out)
-    {
-        if (this->pptr() != this->pbase())
-            if (overflow() == traits_type::eof())
-                return -1;
-        codecvt_base::result __r;
-        do
-        {
-            char* __extbe;
-            __r = __cv_->unshift(__st_, __extbuf_, __extbuf_ + __ebs_, __extbe);
-            streamsize __nmemb = static_cast<streamsize>(__extbe - __extbuf_);
-            if (__bufptr_->sputn(__extbuf_, __nmemb) != __nmemb)
-                return -1;
-        } while (__r == codecvt_base::partial);
-        if (__r == codecvt_base::error)
-            return -1;
-        if (__bufptr_->pubsync())
-            return -1;
-    }
-    else if (__cm_ & ios_base::in)
-    {
-        off_type __c;
-        if (__always_noconv_)
-            __c = this->egptr() - this->gptr();
-        else
-        {
-            int __width = __cv_->encoding();
-            __c = __extbufend_ - __extbufnext_;
-            if (__width > 0)
-                __c += __width * (this->egptr() - this->gptr());
-            else
-            {
-                if (this->gptr() != this->egptr())
-                {
-                    reverse(this->gptr(), this->egptr());
-                    codecvt_base::result __r;
-                    const char_type* __e = this->gptr();
-                    char* __extbe;
-                    do
-                    {
-                        __r = __cv_->out(__st_, __e, this->egptr(), __e,
-                                         __extbuf_, __extbuf_ + __ebs_, __extbe);
-                        switch (__r)
-                        {
-                        case codecvt_base::noconv:
-                            __c += this->egptr() - this->gptr();
-                            break;
-                        case codecvt_base::ok:
-                        case codecvt_base::partial:
-                            __c += __extbe - __extbuf_;
-                            break;
-                        default:
-                            return -1;
-                        }
-                    } while (__r == codecvt_base::partial);
-                }
-            }
-        }
-        if (__bufptr_->pubseekoff(-__c, ios_base::cur, __cm_) == pos_type(off_type(-1)))
-            return -1;
-        this->setg(0, 0, 0);
-        __cm_ = 0;
-    }
-    return 0;
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-bool
-wbuffer_convert<_Codecvt, _Elem, _Tr>::__read_mode()
-{
-    if (!(__cm_ & ios_base::in))
-    {
-        this->setp(0, 0);
-        if (__always_noconv_)
-            this->setg((char_type*)__extbuf_,
-                       (char_type*)__extbuf_ + __ebs_,
-                       (char_type*)__extbuf_ + __ebs_);
-        else
-            this->setg(__intbuf_, __intbuf_ + __ibs_, __intbuf_ + __ibs_);
-        __cm_ = ios_base::in;
-        return true;
-    }
-    return false;
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-void
-wbuffer_convert<_Codecvt, _Elem, _Tr>::__write_mode()
-{
-    if (!(__cm_ & ios_base::out))
-    {
-        this->setg(0, 0, 0);
-        if (__ebs_ > sizeof(__extbuf_min_))
-        {
-            if (__always_noconv_)
-                this->setp((char_type*)__extbuf_,
-                           (char_type*)__extbuf_ + (__ebs_ - 1));
-            else
-                this->setp(__intbuf_, __intbuf_ + (__ibs_ - 1));
-        }
-        else
-            this->setp(0, 0);
-        __cm_ = ios_base::out;
-    }
-}
-
-template <class _Codecvt, class _Elem, class _Tr>
-wbuffer_convert<_Codecvt, _Elem, _Tr>*
-wbuffer_convert<_Codecvt, _Elem, _Tr>::__close()
-{
-    wbuffer_convert* __rt = 0;
-    if (__cv_ != 0 && __bufptr_ != 0)
-    {
-        __rt = this;
-        if ((__cm_ & ios_base::out) && sync())
-            __rt = 0;
-    }
-    return __rt;
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_LOCALE
diff --git a/lib/libcxx/include/locale.h b/lib/libcxx/include/locale.h
deleted file mode 100644
index cad7b8b53eb..00000000000
--- a/lib/libcxx/include/locale.h
+++ /dev/null
@@ -1,45 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- locale.h --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_LOCALE_H
-#define _LIBCPP_LOCALE_H
-
-/*
-    locale.h synopsis
-
-Macros:
-
-    LC_ALL
-    LC_COLLATE
-    LC_CTYPE
-    LC_MONETARY
-    LC_NUMERIC
-    LC_TIME
-
-Types:
-
-    lconv
-
-Functions:
-
-   setlocale
-   localeconv
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <locale.h>
-
-#endif  // _LIBCPP_LOCALE_H
diff --git a/lib/libcxx/include/map b/lib/libcxx/include/map
deleted file mode 100644
index 616bb46cfcc..00000000000
--- a/lib/libcxx/include/map
+++ /dev/null
@@ -1,2178 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- map ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_MAP
-#define _LIBCPP_MAP
-
-/*
-
-    map synopsis
-
-namespace std
-{
-
-template <class Key, class T, class Compare = less<Key>,
-          class Allocator = allocator<pair<const Key, T>>>
-class map
-{
-public:
-    // types:
-    typedef Key                                      key_type;
-    typedef T                                        mapped_type;
-    typedef pair<const key_type, mapped_type>        value_type;
-    typedef Compare                                  key_compare;
-    typedef Allocator                                allocator_type;
-    typedef typename allocator_type::reference       reference;
-    typedef typename allocator_type::const_reference const_reference;
-    typedef typename allocator_type::pointer         pointer;
-    typedef typename allocator_type::const_pointer   const_pointer;
-    typedef typename allocator_type::size_type       size_type;
-    typedef typename allocator_type::difference_type difference_type;
-
-    typedef implementation-defined                   iterator;
-    typedef implementation-defined                   const_iterator;
-    typedef std::reverse_iterator<iterator>          reverse_iterator;
-    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
-    typedef unspecified                              node_type;              // C++17
-    typedef INSERT_RETURN_TYPE<iterator, node_type>  insert_return_type;     // C++17
-
-    class value_compare
-        : public binary_function<value_type, value_type, bool>
-    {
-        friend class map;
-    protected:
-        key_compare comp;
-
-        value_compare(key_compare c);
-    public:
-        bool operator()(const value_type& x, const value_type& y) const;
-    };
-
-    // construct/copy/destroy:
-    map()
-        noexcept(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_default_constructible<key_compare>::value &&
-            is_nothrow_copy_constructible<key_compare>::value);
-    explicit map(const key_compare& comp);
-    map(const key_compare& comp, const allocator_type& a);
-    template <class InputIterator>
-        map(InputIterator first, InputIterator last,
-            const key_compare& comp = key_compare());
-    template <class InputIterator>
-        map(InputIterator first, InputIterator last,
-            const key_compare& comp, const allocator_type& a);
-    map(const map& m);
-    map(map&& m)
-        noexcept(
-            is_nothrow_move_constructible<allocator_type>::value &&
-            is_nothrow_move_constructible<key_compare>::value);
-    explicit map(const allocator_type& a);
-    map(const map& m, const allocator_type& a);
-    map(map&& m, const allocator_type& a);
-    map(initializer_list<value_type> il, const key_compare& comp = key_compare());
-    map(initializer_list<value_type> il, const key_compare& comp, const allocator_type& a);
-    template <class InputIterator>
-        map(InputIterator first, InputIterator last, const allocator_type& a)
-            : map(first, last, Compare(), a) {}  // C++14
-    map(initializer_list<value_type> il, const allocator_type& a)
-        : map(il, Compare(), a) {}  // C++14
-   ~map();
-
-    map& operator=(const map& m);
-    map& operator=(map&& m)
-        noexcept(
-            allocator_type::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<allocator_type>::value &&
-            is_nothrow_move_assignable<key_compare>::value);
-    map& operator=(initializer_list<value_type> il);
-
-    // iterators:
-          iterator begin() noexcept;
-    const_iterator begin() const noexcept;
-          iterator end() noexcept;
-    const_iterator end()   const noexcept;
-
-          reverse_iterator rbegin() noexcept;
-    const_reverse_iterator rbegin() const noexcept;
-          reverse_iterator rend() noexcept;
-    const_reverse_iterator rend()   const noexcept;
-
-    const_iterator         cbegin()  const noexcept;
-    const_iterator         cend()    const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend()   const noexcept;
-
-    // capacity:
-    bool      empty()    const noexcept;
-    size_type size()     const noexcept;
-    size_type max_size() const noexcept;
-
-    // element access:
-    mapped_type& operator[](const key_type& k);
-    mapped_type& operator[](key_type&& k);
-
-          mapped_type& at(const key_type& k);
-    const mapped_type& at(const key_type& k) const;
-
-    // modifiers:
-    template <class... Args>
-        pair<iterator, bool> emplace(Args&&... args);
-    template <class... Args>
-        iterator emplace_hint(const_iterator position, Args&&... args);
-    pair<iterator, bool> insert(const value_type& v);
-    pair<iterator, bool> insert(      value_type&& v);                                // C++17
-    template <class P>
-        pair<iterator, bool> insert(P&& p);
-    iterator insert(const_iterator position, const value_type& v);
-    iterator insert(const_iterator position,       value_type&& v);                   // C++17
-    template <class P>
-        iterator insert(const_iterator position, P&& p);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-    void insert(initializer_list<value_type> il);
-
-    node_type extract(const_iterator position);                                       // C++17
-    node_type extract(const key_type& x);                                             // C++17
-    insert_return_type insert(node_type&& nh);                                        // C++17
-    iterator insert(const_iterator hint, node_type&& nh);                             // C++17
-
-    template <class... Args>
-        pair<iterator, bool> try_emplace(const key_type& k, Args&&... args);          // C++17
-    template <class... Args>
-        pair<iterator, bool> try_emplace(key_type&& k, Args&&... args);               // C++17
-    template <class... Args>
-        iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args); // C++17
-    template <class... Args>
-        iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args);      // C++17
-    template <class M>
-        pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj);            // C++17
-    template <class M>
-        pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj);                 // C++17
-    template <class M>
-        iterator insert_or_assign(const_iterator hint, const key_type& k, M&& obj);   // C++17
-    template <class M>
-        iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj);        // C++17
-
-    iterator  erase(const_iterator position);
-    iterator  erase(iterator position); // C++14
-    size_type erase(const key_type& k);
-    iterator  erase(const_iterator first, const_iterator last);
-    void clear() noexcept;
-
-    template<class C2>
-      void merge(map<Key, T, C2, Allocator>& source);         // C++17
-    template<class C2>
-      void merge(map<Key, T, C2, Allocator>&& source);        // C++17
-    template<class C2>
-      void merge(multimap<Key, T, C2, Allocator>& source);    // C++17
-    template<class C2>
-      void merge(multimap<Key, T, C2, Allocator>&& source);   // C++17
-
-    void swap(map& m)
-        noexcept(allocator_traits<allocator_type>::is_always_equal::value &&
-            is_nothrow_swappable<key_compare>::value); // C++17
-
-    // observers:
-    allocator_type get_allocator() const noexcept;
-    key_compare    key_comp()      const;
-    value_compare  value_comp()    const;
-
-    // map operations:
-          iterator find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    template<typename K>
-        iterator find(const K& x);              // C++14
-    template<typename K>
-        const_iterator find(const K& x) const;  // C++14
-    template<typename K>
-      size_type count(const K& x) const;        // C++14
-
-    size_type      count(const key_type& k) const;
-          iterator lower_bound(const key_type& k);
-    const_iterator lower_bound(const key_type& k) const;
-    template<typename K>
-        iterator lower_bound(const K& x);              // C++14
-    template<typename K>
-        const_iterator lower_bound(const K& x) const;  // C++14
-
-          iterator upper_bound(const key_type& k);
-    const_iterator upper_bound(const key_type& k) const;
-    template<typename K>
-        iterator upper_bound(const K& x);              // C++14
-    template<typename K>
-        const_iterator upper_bound(const K& x) const;  // C++14
-
-    pair<iterator,iterator>             equal_range(const key_type& k);
-    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
-    template<typename K>
-        pair<iterator,iterator>             equal_range(const K& x);        // C++14
-    template<typename K>
-        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
-};
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator==(const map<Key, T, Compare, Allocator>& x,
-           const map<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator< (const map<Key, T, Compare, Allocator>& x,
-           const map<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator!=(const map<Key, T, Compare, Allocator>& x,
-           const map<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator> (const map<Key, T, Compare, Allocator>& x,
-           const map<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator>=(const map<Key, T, Compare, Allocator>& x,
-           const map<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator<=(const map<Key, T, Compare, Allocator>& x,
-           const map<Key, T, Compare, Allocator>& y);
-
-// specialized algorithms:
-template <class Key, class T, class Compare, class Allocator>
-void
-swap(map<Key, T, Compare, Allocator>& x, map<Key, T, Compare, Allocator>& y)
-    noexcept(noexcept(x.swap(y)));
-
-template <class Key, class T, class Compare, class Allocator, class Predicate>
-  void erase_if(map<Key, T, Compare, Allocator>& c, Predicate pred);  // C++20
-
-
-template <class Key, class T, class Compare = less<Key>,
-          class Allocator = allocator<pair<const Key, T>>>
-class multimap
-{
-public:
-    // types:
-    typedef Key                                      key_type;
-    typedef T                                        mapped_type;
-    typedef pair<const key_type,mapped_type>         value_type;
-    typedef Compare                                  key_compare;
-    typedef Allocator                                allocator_type;
-    typedef typename allocator_type::reference       reference;
-    typedef typename allocator_type::const_reference const_reference;
-    typedef typename allocator_type::size_type       size_type;
-    typedef typename allocator_type::difference_type difference_type;
-    typedef typename allocator_type::pointer         pointer;
-    typedef typename allocator_type::const_pointer   const_pointer;
-
-    typedef implementation-defined                   iterator;
-    typedef implementation-defined                   const_iterator;
-    typedef std::reverse_iterator<iterator>          reverse_iterator;
-    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
-    typedef unspecified                              node_type;              // C++17
-
-    class value_compare
-        : public binary_function<value_type,value_type,bool>
-    {
-        friend class multimap;
-    protected:
-        key_compare comp;
-        value_compare(key_compare c);
-    public:
-        bool operator()(const value_type& x, const value_type& y) const;
-    };
-
-    // construct/copy/destroy:
-    multimap()
-        noexcept(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_default_constructible<key_compare>::value &&
-            is_nothrow_copy_constructible<key_compare>::value);
-    explicit multimap(const key_compare& comp);
-    multimap(const key_compare& comp, const allocator_type& a);
-    template <class InputIterator>
-        multimap(InputIterator first, InputIterator last, const key_compare& comp);
-    template <class InputIterator>
-        multimap(InputIterator first, InputIterator last, const key_compare& comp,
-                 const allocator_type& a);
-    multimap(const multimap& m);
-    multimap(multimap&& m)
-        noexcept(
-            is_nothrow_move_constructible<allocator_type>::value &&
-            is_nothrow_move_constructible<key_compare>::value);
-    explicit multimap(const allocator_type& a);
-    multimap(const multimap& m, const allocator_type& a);
-    multimap(multimap&& m, const allocator_type& a);
-    multimap(initializer_list<value_type> il, const key_compare& comp = key_compare());
-    multimap(initializer_list<value_type> il, const key_compare& comp,
-             const allocator_type& a);
-    template <class InputIterator>
-        multimap(InputIterator first, InputIterator last, const allocator_type& a)
-            : multimap(first, last, Compare(), a) {} // C++14
-    multimap(initializer_list<value_type> il, const allocator_type& a)
-        : multimap(il, Compare(), a) {} // C++14
-    ~multimap();
-
-    multimap& operator=(const multimap& m);
-    multimap& operator=(multimap&& m)
-        noexcept(
-            allocator_type::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<allocator_type>::value &&
-            is_nothrow_move_assignable<key_compare>::value);
-    multimap& operator=(initializer_list<value_type> il);
-
-    // iterators:
-          iterator begin() noexcept;
-    const_iterator begin() const noexcept;
-          iterator end() noexcept;
-    const_iterator end()   const noexcept;
-
-          reverse_iterator rbegin() noexcept;
-    const_reverse_iterator rbegin() const noexcept;
-          reverse_iterator rend() noexcept;
-    const_reverse_iterator rend()   const noexcept;
-
-    const_iterator         cbegin()  const noexcept;
-    const_iterator         cend()    const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend()   const noexcept;
-
-    // capacity:
-    bool      empty()    const noexcept;
-    size_type size()     const noexcept;
-    size_type max_size() const noexcept;
-
-    // modifiers:
-    template <class... Args>
-        iterator emplace(Args&&... args);
-    template <class... Args>
-        iterator emplace_hint(const_iterator position, Args&&... args);
-    iterator insert(const value_type& v);
-    iterator insert(      value_type&& v);                                            // C++17
-    template <class P>
-        iterator insert(P&& p);
-    iterator insert(const_iterator position, const value_type& v);
-    iterator insert(const_iterator position,       value_type&& v);                   // C++17
-    template <class P>
-        iterator insert(const_iterator position, P&& p);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-    void insert(initializer_list<value_type> il);
-
-    node_type extract(const_iterator position);                                       // C++17
-    node_type extract(const key_type& x);                                             // C++17
-    iterator insert(node_type&& nh);                                                  // C++17
-    iterator insert(const_iterator hint, node_type&& nh);                             // C++17
-
-    iterator  erase(const_iterator position);
-    iterator  erase(iterator position); // C++14
-    size_type erase(const key_type& k);
-    iterator  erase(const_iterator first, const_iterator last);
-    void clear() noexcept;
-
-    template<class C2>
-      void merge(multimap<Key, T, C2, Allocator>& source);    // C++17
-    template<class C2>
-      void merge(multimap<Key, T, C2, Allocator>&& source);   // C++17
-    template<class C2>
-      void merge(map<Key, T, C2, Allocator>& source);         // C++17
-    template<class C2>
-      void merge(map<Key, T, C2, Allocator>&& source);        // C++17
-
-    void swap(multimap& m)
-        noexcept(allocator_traits<allocator_type>::is_always_equal::value &&
-            is_nothrow_swappable<key_compare>::value); // C++17
-
-    // observers:
-    allocator_type get_allocator() const noexcept;
-    key_compare    key_comp()      const;
-    value_compare  value_comp()    const;
-
-    // map operations:
-          iterator find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    template<typename K>
-        iterator find(const K& x);              // C++14
-    template<typename K>
-        const_iterator find(const K& x) const;  // C++14
-    template<typename K>
-      size_type count(const K& x) const;        // C++14
-
-    size_type      count(const key_type& k) const;
-          iterator lower_bound(const key_type& k);
-    const_iterator lower_bound(const key_type& k) const;
-    template<typename K>
-        iterator lower_bound(const K& x);              // C++14
-    template<typename K>
-        const_iterator lower_bound(const K& x) const;  // C++14
-
-          iterator upper_bound(const key_type& k);
-    const_iterator upper_bound(const key_type& k) const;
-    template<typename K>
-        iterator upper_bound(const K& x);              // C++14
-    template<typename K>
-        const_iterator upper_bound(const K& x) const;  // C++14
-
-    pair<iterator,iterator>             equal_range(const key_type& k);
-    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
-    template<typename K>
-        pair<iterator,iterator>             equal_range(const K& x);        // C++14
-    template<typename K>
-        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
-};
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator==(const multimap<Key, T, Compare, Allocator>& x,
-           const multimap<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator< (const multimap<Key, T, Compare, Allocator>& x,
-           const multimap<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator!=(const multimap<Key, T, Compare, Allocator>& x,
-           const multimap<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator> (const multimap<Key, T, Compare, Allocator>& x,
-           const multimap<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator>=(const multimap<Key, T, Compare, Allocator>& x,
-           const multimap<Key, T, Compare, Allocator>& y);
-
-template <class Key, class T, class Compare, class Allocator>
-bool
-operator<=(const multimap<Key, T, Compare, Allocator>& x,
-           const multimap<Key, T, Compare, Allocator>& y);
-
-// specialized algorithms:
-template <class Key, class T, class Compare, class Allocator>
-void
-swap(multimap<Key, T, Compare, Allocator>& x,
-     multimap<Key, T, Compare, Allocator>& y)
-    noexcept(noexcept(x.swap(y)));
-
-template <class Key, class T, class Compare, class Allocator, class Predicate>
-  void erase_if(multimap<Key, T, Compare, Allocator>& c, Predicate pred);  // C++20
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__tree>
-#include <__node_handle>
-#include <iterator>
-#include <memory>
-#include <utility>
-#include <functional>
-#include <initializer_list>
-#include <type_traits>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Key, class _CP, class _Compare,
-          bool = is_empty<_Compare>::value && !__libcpp_is_final<_Compare>::value>
-class __map_value_compare
-    : private _Compare
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __map_value_compare()
-        _NOEXCEPT_(is_nothrow_default_constructible<_Compare>::value)
-        : _Compare() {}
-    _LIBCPP_INLINE_VISIBILITY
-    __map_value_compare(_Compare c)
-        _NOEXCEPT_(is_nothrow_copy_constructible<_Compare>::value)
-        : _Compare(c) {}
-    _LIBCPP_INLINE_VISIBILITY
-    const _Compare& key_comp() const _NOEXCEPT {return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _CP& __x, const _CP& __y) const
-        {return static_cast<const _Compare&>(*this)(__x.__get_value().first, __y.__get_value().first);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _CP& __x, const _Key& __y) const
-        {return static_cast<const _Compare&>(*this)(__x.__get_value().first, __y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Key& __x, const _CP& __y) const
-        {return static_cast<const _Compare&>(*this)(__x, __y.__get_value().first);}
-    void swap(__map_value_compare&__y)
-        _NOEXCEPT_(__is_nothrow_swappable<_Compare>::value)
-    {
-      using _VSTD::swap;
-      swap(static_cast<_Compare&>(*this), static_cast<_Compare&>(__y));
-    }
-
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value, bool>::type
-    operator () ( const _K2& __x, const _CP& __y ) const
-        {return static_cast<const _Compare&>(*this) (__x, __y.__get_value().first);}
-
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value, bool>::type
-    operator () (const _CP& __x, const _K2& __y) const
-        {return static_cast<const _Compare&>(*this) (__x.__get_value().first, __y);}
-#endif
-};
-
-template <class _Key, class _CP, class _Compare>
-class __map_value_compare<_Key, _CP, _Compare, false>
-{
-    _Compare comp;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __map_value_compare()
-        _NOEXCEPT_(is_nothrow_default_constructible<_Compare>::value)
-        : comp() {}
-    _LIBCPP_INLINE_VISIBILITY
-    __map_value_compare(_Compare c)
-        _NOEXCEPT_(is_nothrow_copy_constructible<_Compare>::value)
-        : comp(c) {}
-    _LIBCPP_INLINE_VISIBILITY
-    const _Compare& key_comp() const _NOEXCEPT {return comp;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _CP& __x, const _CP& __y) const
-        {return comp(__x.__get_value().first, __y.__get_value().first);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _CP& __x, const _Key& __y) const
-        {return comp(__x.__get_value().first, __y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Key& __x, const _CP& __y) const
-        {return comp(__x, __y.__get_value().first);}
-    void swap(__map_value_compare&__y)
-        _NOEXCEPT_(__is_nothrow_swappable<_Compare>::value)
-    {
-        using _VSTD::swap;
-        swap(comp, __y.comp);
-    }
-
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value, bool>::type
-    operator () ( const _K2& __x, const _CP& __y ) const
-        {return comp (__x, __y.__get_value().first);}
-
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value, bool>::type
-    operator () (const _CP& __x, const _K2& __y) const
-        {return comp (__x.__get_value().first, __y);}
-#endif
-};
-
-template <class _Key, class _CP, class _Compare, bool __b>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__map_value_compare<_Key, _CP, _Compare, __b>& __x,
-     __map_value_compare<_Key, _CP, _Compare, __b>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-template <class _Allocator>
-class __map_node_destructor
-{
-    typedef _Allocator                          allocator_type;
-    typedef allocator_traits<allocator_type>    __alloc_traits;
-
-public:
-    typedef typename __alloc_traits::pointer    pointer;
-
-private:
-    allocator_type& __na_;
-
-    __map_node_destructor& operator=(const __map_node_destructor&);
-
-public:
-    bool __first_constructed;
-    bool __second_constructed;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __map_node_destructor(allocator_type& __na) _NOEXCEPT
-        : __na_(__na),
-          __first_constructed(false),
-          __second_constructed(false)
-        {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __map_node_destructor(__tree_node_destructor<allocator_type>&& __x) _NOEXCEPT
-        : __na_(__x.__na_),
-          __first_constructed(__x.__value_constructed),
-          __second_constructed(__x.__value_constructed)
-        {
-            __x.__value_constructed = false;
-        }
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()(pointer __p) _NOEXCEPT
-    {
-        if (__second_constructed)
-            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.__get_value().second));
-        if (__first_constructed)
-            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.__get_value().first));
-        if (__p)
-            __alloc_traits::deallocate(__na_, __p, 1);
-    }
-};
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-    class map;
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-    class multimap;
-template <class _TreeIterator> class __map_const_iterator;
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Tp>
-struct __value_type
-{
-    typedef _Key                                     key_type;
-    typedef _Tp                                      mapped_type;
-    typedef pair<const key_type, mapped_type>        value_type;
-    typedef pair<key_type&, mapped_type&>            __nc_ref_pair_type;
-    typedef pair<key_type&&, mapped_type&&>          __nc_rref_pair_type;
-
-private:
-    value_type __cc;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    value_type& __get_value()
-    {
-#if _LIBCPP_STD_VER > 14
-        return *_VSTD::launder(_VSTD::addressof(__cc));
-#else
-        return __cc;
-#endif
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type& __get_value() const
-    {
-#if _LIBCPP_STD_VER > 14
-        return *_VSTD::launder(_VSTD::addressof(__cc));
-#else
-        return __cc;
-#endif
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __nc_ref_pair_type __ref()
-    {
-        value_type& __v = __get_value();
-        return __nc_ref_pair_type(const_cast<key_type&>(__v.first), __v.second);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __nc_rref_pair_type __move()
-    {
-        value_type& __v = __get_value();
-        return __nc_rref_pair_type(
-            _VSTD::move(const_cast<key_type&>(__v.first)),
-            _VSTD::move(__v.second));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __value_type& operator=(const __value_type& __v)
-    {
-        __ref() = __v.__get_value();
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __value_type& operator=(__value_type&& __v)
-    {
-        __ref() = __v.__move();
-        return *this;
-    }
-
-    template <class _ValueTp,
-              class = typename enable_if<
-                    __is_same_uncvref<_ValueTp, value_type>::value
-                 >::type
-             >
-    _LIBCPP_INLINE_VISIBILITY
-    __value_type& operator=(_ValueTp&& __v)
-    {
-        __ref() = _VSTD::forward<_ValueTp>(__v);
-        return *this;
-    }
-
-private:
-    __value_type() _LIBCPP_EQUAL_DELETE;
-    ~__value_type() _LIBCPP_EQUAL_DELETE;
-    __value_type(const __value_type& __v) _LIBCPP_EQUAL_DELETE;
-    __value_type(__value_type&& __v) _LIBCPP_EQUAL_DELETE;
-};
-
-#else
-
-template <class _Key, class _Tp>
-struct __value_type
-{
-    typedef _Key                                     key_type;
-    typedef _Tp                                      mapped_type;
-    typedef pair<const key_type, mapped_type>        value_type;
-
-private:
-    value_type __cc;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    value_type& __get_value() { return __cc; }
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type& __get_value() const { return __cc; }
-
-private:
-   __value_type();
-   __value_type(__value_type const&);
-   __value_type& operator=(__value_type const&);
-   ~__value_type();
-};
-
-#endif // _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-struct __extract_key_value_types;
-
-template <class _Key, class _Tp>
-struct __extract_key_value_types<__value_type<_Key, _Tp> >
-{
-  typedef _Key const __key_type;
-  typedef _Tp        __mapped_type;
-};
-
-template <class _TreeIterator>
-class _LIBCPP_TEMPLATE_VIS __map_iterator
-{
-    typedef typename _TreeIterator::_NodeTypes                   _NodeTypes;
-    typedef typename _TreeIterator::__pointer_traits             __pointer_traits;
-
-    _TreeIterator __i_;
-
-public:
-    typedef bidirectional_iterator_tag                           iterator_category;
-    typedef typename _NodeTypes::__map_value_type                value_type;
-    typedef typename _TreeIterator::difference_type              difference_type;
-    typedef value_type&                                          reference;
-    typedef typename _NodeTypes::__map_value_type_pointer        pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __map_iterator() _NOEXCEPT {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __map_iterator(_TreeIterator __i) _NOEXCEPT : __i_(__i) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {return __i_->__get_value();}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {return pointer_traits<pointer>::pointer_to(__i_->__get_value());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __map_iterator& operator++() {++__i_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    __map_iterator operator++(int)
-    {
-        __map_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __map_iterator& operator--() {--__i_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    __map_iterator operator--(int)
-    {
-        __map_iterator __t(*this);
-        --(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __map_iterator& __x, const __map_iterator& __y)
-        {return __x.__i_ == __y.__i_;}
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __map_iterator& __x, const __map_iterator& __y)
-        {return __x.__i_ != __y.__i_;}
-
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __map_const_iterator;
-};
-
-template <class _TreeIterator>
-class _LIBCPP_TEMPLATE_VIS __map_const_iterator
-{
-    typedef typename _TreeIterator::_NodeTypes                   _NodeTypes;
-    typedef typename _TreeIterator::__pointer_traits             __pointer_traits;
-
-    _TreeIterator __i_;
-
-public:
-    typedef bidirectional_iterator_tag                           iterator_category;
-    typedef typename _NodeTypes::__map_value_type                value_type;
-    typedef typename _TreeIterator::difference_type              difference_type;
-    typedef const value_type&                                    reference;
-    typedef typename _NodeTypes::__const_map_value_type_pointer  pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __map_const_iterator() _NOEXCEPT {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __map_const_iterator(_TreeIterator __i) _NOEXCEPT : __i_(__i) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __map_const_iterator(__map_iterator<
-        typename _TreeIterator::__non_const_iterator> __i) _NOEXCEPT
-        : __i_(__i.__i_) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {return __i_->__get_value();}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {return pointer_traits<pointer>::pointer_to(__i_->__get_value());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __map_const_iterator& operator++() {++__i_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    __map_const_iterator operator++(int)
-    {
-        __map_const_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __map_const_iterator& operator--() {--__i_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    __map_const_iterator operator--(int)
-    {
-        __map_const_iterator __t(*this);
-        --(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const __map_const_iterator& __x, const __map_const_iterator& __y)
-        {return __x.__i_ == __y.__i_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const __map_const_iterator& __x, const __map_const_iterator& __y)
-        {return __x.__i_ != __y.__i_;}
-
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS multimap;
-    template <class, class, class> friend class _LIBCPP_TEMPLATE_VIS __tree_const_iterator;
-};
-
-template <class _Key, class _Tp, class _Compare = less<_Key>,
-          class _Allocator = allocator<pair<const _Key, _Tp> > >
-class _LIBCPP_TEMPLATE_VIS map
-{
-public:
-    // types:
-    typedef _Key                                     key_type;
-    typedef _Tp                                      mapped_type;
-    typedef pair<const key_type, mapped_type>        value_type;
-    typedef _Compare                                 key_compare;
-    typedef _Allocator                               allocator_type;
-    typedef value_type&                              reference;
-    typedef const value_type&                        const_reference;
-
-    static_assert(sizeof(__diagnose_non_const_comparator<_Key, _Compare>()), "");
-    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
-                  "Allocator::value_type must be same type as value_type");
-
-    class _LIBCPP_TEMPLATE_VIS value_compare
-        : public binary_function<value_type, value_type, bool>
-    {
-        friend class map;
-    protected:
-        key_compare comp;
-
-        _LIBCPP_INLINE_VISIBILITY value_compare(key_compare c) : comp(c) {}
-    public:
-        _LIBCPP_INLINE_VISIBILITY
-        bool operator()(const value_type& __x, const value_type& __y) const
-            {return comp(__x.first, __y.first);}
-    };
-
-private:
-
-    typedef _VSTD::__value_type<key_type, mapped_type>             __value_type;
-    typedef __map_value_compare<key_type, __value_type, key_compare> __vc;
-    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>,
-                                                 __value_type>::type __allocator_type;
-    typedef __tree<__value_type, __vc, __allocator_type>   __base;
-    typedef typename __base::__node_traits                 __node_traits;
-    typedef allocator_traits<allocator_type>               __alloc_traits;
-
-    __base __tree_;
-
-public:
-    typedef typename __alloc_traits::pointer               pointer;
-    typedef typename __alloc_traits::const_pointer         const_pointer;
-    typedef typename __alloc_traits::size_type             size_type;
-    typedef typename __alloc_traits::difference_type       difference_type;
-    typedef __map_iterator<typename __base::iterator>             iterator;
-    typedef __map_const_iterator<typename __base::const_iterator> const_iterator;
-    typedef _VSTD::reverse_iterator<iterator>               reverse_iterator;
-    typedef _VSTD::reverse_iterator<const_iterator>         const_reverse_iterator;
-
-#if _LIBCPP_STD_VER > 14
-    typedef __map_node_handle<typename __base::__node, allocator_type> node_type;
-    typedef __insert_return_type<iterator, node_type> insert_return_type;
-#endif
-
-    template <class _Key2, class _Value2, class _Comp2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class _Key2, class _Value2, class _Comp2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS multimap;
-
-    _LIBCPP_INLINE_VISIBILITY
-    map()
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_default_constructible<key_compare>::value &&
-            is_nothrow_copy_constructible<key_compare>::value)
-        : __tree_(__vc(key_compare())) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit map(const key_compare& __comp)
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_copy_constructible<key_compare>::value)
-        : __tree_(__vc(__comp)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit map(const key_compare& __comp, const allocator_type& __a)
-        : __tree_(__vc(__comp), typename __base::allocator_type(__a)) {}
-
-    template <class _InputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-        map(_InputIterator __f, _InputIterator __l,
-            const key_compare& __comp = key_compare())
-        : __tree_(__vc(__comp))
-        {
-            insert(__f, __l);
-        }
-
-    template <class _InputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-        map(_InputIterator __f, _InputIterator __l,
-            const key_compare& __comp, const allocator_type& __a)
-        : __tree_(__vc(__comp), typename __base::allocator_type(__a))
-        {
-            insert(__f, __l);
-        }
-
-#if _LIBCPP_STD_VER > 11
-    template <class _InputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-    map(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
-        : map(__f, __l, key_compare(), __a) {}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    map(const map& __m)
-        : __tree_(__m.__tree_)
-        {
-            insert(__m.begin(), __m.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    map& operator=(const map& __m)
-        {
-#ifndef _LIBCPP_CXX03_LANG
-            __tree_ = __m.__tree_;
-#else
-            if (this != &__m) {
-                __tree_.clear();
-                __tree_.value_comp() = __m.__tree_.value_comp();
-                __tree_.__copy_assign_alloc(__m.__tree_);
-                insert(__m.begin(), __m.end());
-            }
-#endif
-            return *this;
-        }
-
-#ifndef _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    map(map&& __m)
-        _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
-        : __tree_(_VSTD::move(__m.__tree_))
-        {
-        }
-
-    map(map&& __m, const allocator_type& __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    map& operator=(map&& __m)
-        _NOEXCEPT_(is_nothrow_move_assignable<__base>::value)
-        {
-            __tree_ = _VSTD::move(__m.__tree_);
-            return *this;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    map(initializer_list<value_type> __il, const key_compare& __comp = key_compare())
-        : __tree_(__vc(__comp))
-        {
-            insert(__il.begin(), __il.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    map(initializer_list<value_type> __il, const key_compare& __comp, const allocator_type& __a)
-        : __tree_(__vc(__comp), typename __base::allocator_type(__a))
-        {
-            insert(__il.begin(), __il.end());
-        }
-
-#if _LIBCPP_STD_VER > 11
-    _LIBCPP_INLINE_VISIBILITY
-    map(initializer_list<value_type> __il, const allocator_type& __a)
-        : map(__il, key_compare(), __a) {}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    map& operator=(initializer_list<value_type> __il)
-        {
-            __tree_.__assign_unique(__il.begin(), __il.end());
-            return *this;
-        }
-
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit map(const allocator_type& __a)
-        : __tree_(typename __base::allocator_type(__a))
-        {
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    map(const map& __m, const allocator_type& __a)
-        : __tree_(__m.__tree_.value_comp(), typename __base::allocator_type(__a))
-        {
-            insert(__m.begin(), __m.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-          iterator begin() _NOEXCEPT {return __tree_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT {return __tree_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-          iterator end() _NOEXCEPT {return __tree_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT {return __tree_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin() const _NOEXCEPT
-        {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rend() _NOEXCEPT
-            {return       reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend() const _NOEXCEPT
-        {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const _NOEXCEPT {return __tree_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT {return __tree_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {return __tree_.max_size();}
-
-    mapped_type& operator[](const key_type& __k);
-#ifndef _LIBCPP_CXX03_LANG
-    mapped_type& operator[](key_type&& __k);
-#endif
-
-          mapped_type& at(const key_type& __k);
-    const mapped_type& at(const key_type& __k) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT {return allocator_type(__tree_.__alloc());}
-    _LIBCPP_INLINE_VISIBILITY
-    key_compare    key_comp()      const {return __tree_.value_comp().key_comp();}
-    _LIBCPP_INLINE_VISIBILITY
-    value_compare  value_comp()    const {return value_compare(__tree_.value_comp().key_comp());}
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> emplace(_Args&& ...__args) {
-        return __tree_.__emplace_unique(_VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator emplace_hint(const_iterator __p, _Args&& ...__args) {
-        return __tree_.__emplace_hint_unique(__p.__i_, _VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class _Pp,
-              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> insert(_Pp&& __p)
-            {return __tree_.__insert_unique(_VSTD::forward<_Pp>(__p));}
-
-    template <class _Pp,
-              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator insert(const_iterator __pos, _Pp&& __p)
-            {return __tree_.__insert_unique(__pos.__i_, _VSTD::forward<_Pp>(__p));}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-        insert(const value_type& __v) {return __tree_.__insert_unique(__v);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator
-        insert(const_iterator __p, const value_type& __v)
-            {return __tree_.__insert_unique(__p.__i_, __v);}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool>
-    insert(value_type&& __v) {return __tree_.__insert_unique(_VSTD::move(__v));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p,  value_type&& __v)
-    {return __tree_.__insert_unique(__p.__i_, _VSTD::move(__v));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(initializer_list<value_type> __il)
-        {insert(__il.begin(), __il.end());}
-#endif
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __f, _InputIterator __l)
-        {
-            for (const_iterator __e = cend(); __f != __l; ++__f)
-                insert(__e.__i_, *__f);
-        }
-
-#if _LIBCPP_STD_VER > 14
-
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> try_emplace(const key_type& __k, _Args&&... __args)
-    {
-        return __tree_.__emplace_unique_key_args(__k,
-            _VSTD::piecewise_construct,
-            _VSTD::forward_as_tuple(__k),
-            _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...));
-    }
-
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> try_emplace(key_type&& __k, _Args&&... __args)
-    {
-        return __tree_.__emplace_unique_key_args(__k,
-            _VSTD::piecewise_construct,
-            _VSTD::forward_as_tuple(_VSTD::move(__k)),
-            _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...));
-    }
-
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator try_emplace(const_iterator __h, const key_type& __k, _Args&&... __args)
-    {
-        return __tree_.__emplace_hint_unique_key_args(__h.__i_, __k,
-            _VSTD::piecewise_construct,
-            _VSTD::forward_as_tuple(__k),
-            _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...));
-    }
-
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator try_emplace(const_iterator __h, key_type&& __k, _Args&&... __args)
-    {
-        return __tree_.__emplace_hint_unique_key_args(__h.__i_, __k,
-            _VSTD::piecewise_construct,
-            _VSTD::forward_as_tuple(_VSTD::move(__k)),
-            _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...));
-    }
-
-    template <class _Vp>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> insert_or_assign(const key_type& __k, _Vp&& __v)
-    {
-        iterator __p = lower_bound(__k);
-        if ( __p != end() && !key_comp()(__k, __p->first))
-        {
-            __p->second = _VSTD::forward<_Vp>(__v);
-            return _VSTD::make_pair(__p, false);
-        }
-        return _VSTD::make_pair(emplace_hint(__p, __k, _VSTD::forward<_Vp>(__v)), true);
-    }
-
-    template <class _Vp>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> insert_or_assign(key_type&& __k, _Vp&& __v)
-    {
-        iterator __p = lower_bound(__k);
-        if ( __p != end() && !key_comp()(__k, __p->first))
-        {
-            __p->second = _VSTD::forward<_Vp>(__v);
-            return _VSTD::make_pair(__p, false);
-        }
-        return _VSTD::make_pair(emplace_hint(__p, _VSTD::move(__k), _VSTD::forward<_Vp>(__v)), true);
-    }
-
-    template <class _Vp>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator insert_or_assign(const_iterator __h, const key_type& __k, _Vp&& __v)
-     {
-        iterator __p = lower_bound(__k);
-        if ( __p != end() && !key_comp()(__k, __p->first))
-        {
-            __p->second = _VSTD::forward<_Vp>(__v);
-            return __p;
-        }
-        return emplace_hint(__h, __k, _VSTD::forward<_Vp>(__v));
-     }
-
-    template <class _Vp>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator insert_or_assign(const_iterator __h, key_type&& __k, _Vp&& __v)
-     {
-        iterator __p = lower_bound(__k);
-        if ( __p != end() && !key_comp()(__k, __p->first))
-        {
-            __p->second = _VSTD::forward<_Vp>(__v);
-            return __p;
-        }
-        return emplace_hint(__h, _VSTD::move(__k), _VSTD::forward<_Vp>(__v));
-     }
-
-#endif // _LIBCPP_STD_VER > 14
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __p) {return __tree_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(iterator __p)       {return __tree_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k)
-        {return __tree_.__erase_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator  erase(const_iterator __f, const_iterator __l)
-        {return __tree_.erase(__f.__i_, __l.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {__tree_.clear();}
-
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY
-    insert_return_type insert(node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to map::insert()");
-        return __tree_.template __node_handle_insert_unique<
-            node_type, insert_return_type>(_VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __hint, node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to map::insert()");
-        return __tree_.template __node_handle_insert_unique<node_type>(
-            __hint.__i_, _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(key_type const& __key)
-    {
-        return __tree_.template __node_handle_extract<node_type>(__key);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(const_iterator __it)
-    {
-        return __tree_.template __node_handle_extract<node_type>(__it.__i_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(map<key_type, mapped_type, _Compare2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_unique(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(map<key_type, mapped_type, _Compare2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_unique(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(multimap<key_type, mapped_type, _Compare2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_unique(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(multimap<key_type, mapped_type, _Compare2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_unique(__source.__tree_);
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(map& __m)
-        _NOEXCEPT_(__is_nothrow_swappable<__base>::value)
-        {__tree_.swap(__m.__tree_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator find(const key_type& __k)             {return __tree_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __tree_.find(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
-    find(const _K2& __k)                           {return __tree_.find(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    find(const _K2& __k) const                     {return __tree_.find(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type      count(const key_type& __k) const
-        {return __tree_.__count_unique(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,size_type>::type
-    count(const _K2& __k) const {return __tree_.__count_multi(__k);}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    iterator lower_bound(const key_type& __k)
-        {return __tree_.lower_bound(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator lower_bound(const key_type& __k) const
-        {return __tree_.lower_bound(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
-    lower_bound(const _K2& __k)       {return __tree_.lower_bound(__k);}
-
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    lower_bound(const _K2& __k) const {return __tree_.lower_bound(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator upper_bound(const key_type& __k)
-        {return __tree_.upper_bound(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator upper_bound(const key_type& __k) const
-        {return __tree_.upper_bound(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
-    upper_bound(const _K2& __k)       {return __tree_.upper_bound(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    upper_bound(const _K2& __k) const {return __tree_.upper_bound(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator,iterator> equal_range(const key_type& __k)
-        {return __tree_.__equal_range_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator,const_iterator> equal_range(const key_type& __k) const
-        {return __tree_.__equal_range_unique(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<iterator,iterator>>::type
-    equal_range(const _K2& __k)       {return __tree_.__equal_range_multi(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<const_iterator,const_iterator>>::type
-    equal_range(const _K2& __k) const {return __tree_.__equal_range_multi(__k);}
-#endif
-
-private:
-    typedef typename __base::__node                    __node;
-    typedef typename __base::__node_allocator          __node_allocator;
-    typedef typename __base::__node_pointer            __node_pointer;
-    typedef typename __base::__node_base_pointer       __node_base_pointer;
-    typedef typename __base::__parent_pointer          __parent_pointer;
-
-    typedef __map_node_destructor<__node_allocator> _Dp;
-    typedef unique_ptr<__node, _Dp> __node_holder;
-
-#ifdef _LIBCPP_CXX03_LANG
-    __node_holder __construct_node_with_key(const key_type& __k);
-#endif
-};
-
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-map<_Key, _Tp, _Compare, _Allocator>::map(map&& __m, const allocator_type& __a)
-    : __tree_(_VSTD::move(__m.__tree_), typename __base::allocator_type(__a))
-{
-    if (__a != __m.get_allocator())
-    {
-        const_iterator __e = cend();
-        while (!__m.empty())
-            __tree_.__insert_unique(__e.__i_,
-                    __m.__tree_.remove(__m.begin().__i_)->__value_.__move());
-    }
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-_Tp&
-map<_Key, _Tp, _Compare, _Allocator>::operator[](const key_type& __k)
-{
-    return __tree_.__emplace_unique_key_args(__k,
-        _VSTD::piecewise_construct,
-        _VSTD::forward_as_tuple(__k),
-        _VSTD::forward_as_tuple()).first->__get_value().second;
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-_Tp&
-map<_Key, _Tp, _Compare, _Allocator>::operator[](key_type&& __k)
-{
-    return __tree_.__emplace_unique_key_args(__k,
-        _VSTD::piecewise_construct,
-        _VSTD::forward_as_tuple(_VSTD::move(__k)),
-        _VSTD::forward_as_tuple()).first->__get_value().second;
-}
-
-#else // _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-typename map<_Key, _Tp, _Compare, _Allocator>::__node_holder
-map<_Key, _Tp, _Compare, _Allocator>::__construct_node_with_key(const key_type& __k)
-{
-    __node_allocator& __na = __tree_.__node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__get_value().first), __k);
-    __h.get_deleter().__first_constructed = true;
-    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__get_value().second));
-    __h.get_deleter().__second_constructed = true;
-    return _LIBCPP_EXPLICIT_MOVE(__h);  // explicitly moved for C++03
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-_Tp&
-map<_Key, _Tp, _Compare, _Allocator>::operator[](const key_type& __k)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __tree_.__find_equal(__parent, __k);
-    __node_pointer __r = static_cast<__node_pointer>(__child);
-    if (__child == nullptr)
-    {
-        __node_holder __h = __construct_node_with_key(__k);
-        __tree_.__insert_node_at(__parent, __child, static_cast<__node_base_pointer>(__h.get()));
-        __r = __h.release();
-    }
-    return __r->__value_.__get_value().second;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-_Tp&
-map<_Key, _Tp, _Compare, _Allocator>::at(const key_type& __k)
-{
-    __parent_pointer __parent;
-    __node_base_pointer& __child = __tree_.__find_equal(__parent, __k);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    if (__child == nullptr)
-        throw out_of_range("map::at:  key not found");
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return static_cast<__node_pointer>(__child)->__value_.__get_value().second;
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-const _Tp&
-map<_Key, _Tp, _Compare, _Allocator>::at(const key_type& __k) const
-{
-    __parent_pointer __parent;
-    __node_base_pointer __child = __tree_.__find_equal(__parent, __k);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    if (__child == nullptr)
-        throw out_of_range("map::at:  key not found");
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return static_cast<__node_pointer>(__child)->__value_.__get_value().second;
-}
-
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const map<_Key, _Tp, _Compare, _Allocator>& __x,
-           const map<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const map<_Key, _Tp, _Compare, _Allocator>& __x,
-           const map<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const map<_Key, _Tp, _Compare, _Allocator>& __x,
-           const map<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const map<_Key, _Tp, _Compare, _Allocator>& __x,
-           const map<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const map<_Key, _Tp, _Compare, _Allocator>& __x,
-           const map<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const map<_Key, _Tp, _Compare, _Allocator>& __x,
-           const map<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(map<_Key, _Tp, _Compare, _Allocator>& __x,
-     map<_Key, _Tp, _Compare, _Allocator>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Key, class _Tp, class _Compare, class _Allocator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(map<_Key, _Tp, _Compare, _Allocator>& __c, _Predicate __pred)
-{ __libcpp_erase_if_container(__c, __pred); }
-#endif
-
-
-template <class _Key, class _Tp, class _Compare = less<_Key>,
-          class _Allocator = allocator<pair<const _Key, _Tp> > >
-class _LIBCPP_TEMPLATE_VIS multimap
-{
-public:
-    // types:
-    typedef _Key                                     key_type;
-    typedef _Tp                                      mapped_type;
-    typedef pair<const key_type, mapped_type>        value_type;
-    typedef _Compare                                 key_compare;
-    typedef _Allocator                               allocator_type;
-    typedef value_type&                              reference;
-    typedef const value_type&                        const_reference;
-
-    static_assert(sizeof(__diagnose_non_const_comparator<_Key, _Compare>()), "");
-    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
-                  "Allocator::value_type must be same type as value_type");
-
-    class _LIBCPP_TEMPLATE_VIS value_compare
-        : public binary_function<value_type, value_type, bool>
-    {
-        friend class multimap;
-    protected:
-        key_compare comp;
-
-        _LIBCPP_INLINE_VISIBILITY
-        value_compare(key_compare c) : comp(c) {}
-    public:
-        _LIBCPP_INLINE_VISIBILITY
-        bool operator()(const value_type& __x, const value_type& __y) const
-            {return comp(__x.first, __y.first);}
-    };
-
-private:
-
-    typedef _VSTD::__value_type<key_type, mapped_type>             __value_type;
-    typedef __map_value_compare<key_type, __value_type, key_compare> __vc;
-    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>,
-                                                 __value_type>::type __allocator_type;
-    typedef __tree<__value_type, __vc, __allocator_type>            __base;
-    typedef typename __base::__node_traits                          __node_traits;
-    typedef allocator_traits<allocator_type>                        __alloc_traits;
-
-    __base __tree_;
-
-public:
-    typedef typename __alloc_traits::pointer               pointer;
-    typedef typename __alloc_traits::const_pointer         const_pointer;
-    typedef typename __alloc_traits::size_type             size_type;
-    typedef typename __alloc_traits::difference_type       difference_type;
-    typedef __map_iterator<typename __base::iterator>      iterator;
-    typedef __map_const_iterator<typename __base::const_iterator> const_iterator;
-    typedef _VSTD::reverse_iterator<iterator>               reverse_iterator;
-    typedef _VSTD::reverse_iterator<const_iterator>         const_reverse_iterator;
-
-#if _LIBCPP_STD_VER > 14
-    typedef __map_node_handle<typename __base::__node, allocator_type> node_type;
-#endif
-
-    template <class _Key2, class _Value2, class _Comp2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS map;
-    template <class _Key2, class _Value2, class _Comp2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS multimap;
-
-    _LIBCPP_INLINE_VISIBILITY
-    multimap()
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_default_constructible<key_compare>::value &&
-            is_nothrow_copy_constructible<key_compare>::value)
-        : __tree_(__vc(key_compare())) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit multimap(const key_compare& __comp)
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_copy_constructible<key_compare>::value)
-        : __tree_(__vc(__comp)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit multimap(const key_compare& __comp, const allocator_type& __a)
-        : __tree_(__vc(__comp), typename __base::allocator_type(__a)) {}
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        multimap(_InputIterator __f, _InputIterator __l,
-            const key_compare& __comp = key_compare())
-        : __tree_(__vc(__comp))
-        {
-            insert(__f, __l);
-        }
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        multimap(_InputIterator __f, _InputIterator __l,
-            const key_compare& __comp, const allocator_type& __a)
-        : __tree_(__vc(__comp), typename __base::allocator_type(__a))
-        {
-            insert(__f, __l);
-        }
-
-#if _LIBCPP_STD_VER > 11
-    template <class _InputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-    multimap(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
-        : multimap(__f, __l, key_compare(), __a) {}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    multimap(const multimap& __m)
-        : __tree_(__m.__tree_.value_comp(),
-          __alloc_traits::select_on_container_copy_construction(__m.__tree_.__alloc()))
-        {
-            insert(__m.begin(), __m.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    multimap& operator=(const multimap& __m)
-        {
-#ifndef _LIBCPP_CXX03_LANG
-            __tree_ = __m.__tree_;
-#else
-            if (this != &__m) {
-                __tree_.clear();
-                __tree_.value_comp() = __m.__tree_.value_comp();
-                __tree_.__copy_assign_alloc(__m.__tree_);
-                insert(__m.begin(), __m.end());
-            }
-#endif
-            return *this;
-        }
-
-#ifndef _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    multimap(multimap&& __m)
-        _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
-        : __tree_(_VSTD::move(__m.__tree_))
-        {
-        }
-
-    multimap(multimap&& __m, const allocator_type& __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    multimap& operator=(multimap&& __m)
-        _NOEXCEPT_(is_nothrow_move_assignable<__base>::value)
-        {
-            __tree_ = _VSTD::move(__m.__tree_);
-            return *this;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    multimap(initializer_list<value_type> __il, const key_compare& __comp = key_compare())
-        : __tree_(__vc(__comp))
-        {
-            insert(__il.begin(), __il.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    multimap(initializer_list<value_type> __il, const key_compare& __comp, const allocator_type& __a)
-        : __tree_(__vc(__comp), typename __base::allocator_type(__a))
-        {
-            insert(__il.begin(), __il.end());
-        }
-
-#if _LIBCPP_STD_VER > 11
-    _LIBCPP_INLINE_VISIBILITY
-    multimap(initializer_list<value_type> __il, const allocator_type& __a)
-        : multimap(__il, key_compare(), __a) {}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    multimap& operator=(initializer_list<value_type> __il)
-        {
-            __tree_.__assign_multi(__il.begin(), __il.end());
-            return *this;
-        }
-
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit multimap(const allocator_type& __a)
-        : __tree_(typename __base::allocator_type(__a))
-        {
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    multimap(const multimap& __m, const allocator_type& __a)
-        : __tree_(__m.__tree_.value_comp(), typename __base::allocator_type(__a))
-        {
-            insert(__m.begin(), __m.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-          iterator begin() _NOEXCEPT {return __tree_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT {return __tree_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-          iterator end() _NOEXCEPT {return __tree_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT {return __tree_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rbegin() _NOEXCEPT {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin() const _NOEXCEPT
-        {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rend() _NOEXCEPT {return reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend() const _NOEXCEPT
-        {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin()  const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT {return __tree_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT {return __tree_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {return __tree_.max_size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT {return allocator_type(__tree_.__alloc());}
-    _LIBCPP_INLINE_VISIBILITY
-    key_compare    key_comp() const {return __tree_.value_comp().key_comp();}
-    _LIBCPP_INLINE_VISIBILITY
-    value_compare  value_comp() const
-        {return value_compare(__tree_.value_comp().key_comp());}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator emplace(_Args&& ...__args) {
-        return __tree_.__emplace_multi(_VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class ..._Args>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator emplace_hint(const_iterator __p, _Args&& ...__args) {
-        return __tree_.__emplace_hint_multi(__p.__i_, _VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class _Pp,
-              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator insert(_Pp&& __p)
-            {return __tree_.__insert_multi(_VSTD::forward<_Pp>(__p));}
-
-    template <class _Pp,
-              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator insert(const_iterator __pos, _Pp&& __p)
-            {return __tree_.__insert_multi(__pos.__i_, _VSTD::forward<_Pp>(__p));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(value_type&& __v)
-        {return __tree_.__insert_multi(_VSTD::move(__v));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, value_type&& __v)
-        {return __tree_.__insert_multi(__p.__i_, _VSTD::move(__v));}
-
-
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(initializer_list<value_type> __il)
-        {insert(__il.begin(), __il.end());}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const value_type& __v) {return __tree_.__insert_multi(__v);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, const value_type& __v)
-            {return __tree_.__insert_multi(__p.__i_, __v);}
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __f, _InputIterator __l)
-        {
-            for (const_iterator __e = cend(); __f != __l; ++__f)
-                __tree_.__insert_multi(__e.__i_, *__f);
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __p) {return __tree_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(iterator __p)       {return __tree_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __tree_.__erase_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator  erase(const_iterator __f, const_iterator __l)
-        {return __tree_.erase(__f.__i_, __l.__i_);}
-
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to multimap::insert()");
-        return __tree_.template __node_handle_insert_multi<node_type>(
-            _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __hint, node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to multimap::insert()");
-        return __tree_.template __node_handle_insert_multi<node_type>(
-            __hint.__i_, _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(key_type const& __key)
-    {
-        return __tree_.template __node_handle_extract<node_type>(__key);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(const_iterator __it)
-    {
-        return __tree_.template __node_handle_extract<node_type>(
-            __it.__i_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(multimap<key_type, mapped_type, _Compare2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __tree_.__node_handle_merge_multi(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(multimap<key_type, mapped_type, _Compare2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __tree_.__node_handle_merge_multi(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(map<key_type, mapped_type, _Compare2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __tree_.__node_handle_merge_multi(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(map<key_type, mapped_type, _Compare2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __tree_.__node_handle_merge_multi(__source.__tree_);
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {__tree_.clear();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(multimap& __m)
-        _NOEXCEPT_(__is_nothrow_swappable<__base>::value)
-        {__tree_.swap(__m.__tree_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator find(const key_type& __k)             {return __tree_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __tree_.find(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
-    find(const _K2& __k)                           {return __tree_.find(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    find(const _K2& __k) const                     {return __tree_.find(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type      count(const key_type& __k) const
-        {return __tree_.__count_multi(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,size_type>::type
-    count(const _K2& __k) const {return __tree_.__count_multi(__k);}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    iterator lower_bound(const key_type& __k)
-        {return __tree_.lower_bound(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator lower_bound(const key_type& __k) const
-            {return __tree_.lower_bound(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
-    lower_bound(const _K2& __k)       {return __tree_.lower_bound(__k);}
-
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    lower_bound(const _K2& __k) const {return __tree_.lower_bound(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator upper_bound(const key_type& __k)
-            {return __tree_.upper_bound(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator upper_bound(const key_type& __k) const
-            {return __tree_.upper_bound(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
-    upper_bound(const _K2& __k)       {return __tree_.upper_bound(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    upper_bound(const _K2& __k) const {return __tree_.upper_bound(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator,iterator>             equal_range(const key_type& __k)
-            {return __tree_.__equal_range_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator,const_iterator> equal_range(const key_type& __k) const
-            {return __tree_.__equal_range_multi(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<iterator,iterator>>::type
-    equal_range(const _K2& __k)       {return __tree_.__equal_range_multi(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<const_iterator,const_iterator>>::type
-    equal_range(const _K2& __k) const {return __tree_.__equal_range_multi(__k);}
-#endif
-
-private:
-    typedef typename __base::__node                    __node;
-    typedef typename __base::__node_allocator          __node_allocator;
-    typedef typename __base::__node_pointer            __node_pointer;
-
-    typedef __map_node_destructor<__node_allocator> _Dp;
-    typedef unique_ptr<__node, _Dp> __node_holder;
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-multimap<_Key, _Tp, _Compare, _Allocator>::multimap(multimap&& __m, const allocator_type& __a)
-    : __tree_(_VSTD::move(__m.__tree_), typename __base::allocator_type(__a))
-{
-    if (__a != __m.get_allocator())
-    {
-        const_iterator __e = cend();
-        while (!__m.empty())
-            __tree_.__insert_multi(__e.__i_,
-                    _VSTD::move(__m.__tree_.remove(__m.begin().__i_)->__value_.__move()));
-    }
-}
-#endif
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
-           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
-           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
-           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
-           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
-           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const multimap<_Key, _Tp, _Compare, _Allocator>& __x,
-           const multimap<_Key, _Tp, _Compare, _Allocator>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Key, class _Tp, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(multimap<_Key, _Tp, _Compare, _Allocator>& __x,
-     multimap<_Key, _Tp, _Compare, _Allocator>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Key, class _Tp, class _Compare, class _Allocator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(multimap<_Key, _Tp, _Compare, _Allocator>& __c, _Predicate __pred)
-{ __libcpp_erase_if_container(__c, __pred); }
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_MAP
diff --git a/lib/libcxx/include/math.h b/lib/libcxx/include/math.h
deleted file mode 100644
index 3cc72aa2791..00000000000
--- a/lib/libcxx/include/math.h
+++ /dev/null
@@ -1,1531 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- math.h ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_MATH_H
-#define _LIBCPP_MATH_H
-
-/*
-    math.h synopsis
-
-Macros:
-
-    HUGE_VAL
-    HUGE_VALF               // C99
-    HUGE_VALL               // C99
-    INFINITY                // C99
-    NAN                     // C99
-    FP_INFINITE             // C99
-    FP_NAN                  // C99
-    FP_NORMAL               // C99
-    FP_SUBNORMAL            // C99
-    FP_ZERO                 // C99
-    FP_FAST_FMA             // C99
-    FP_FAST_FMAF            // C99
-    FP_FAST_FMAL            // C99
-    FP_ILOGB0               // C99
-    FP_ILOGBNAN             // C99
-    MATH_ERRNO              // C99
-    MATH_ERREXCEPT          // C99
-    math_errhandling        // C99
-
-Types:
-
-    float_t                 // C99
-    double_t                // C99
-
-// C90
-
-floating_point abs(floating_point x);
-
-floating_point acos (arithmetic x);
-float          acosf(float x);
-long double    acosl(long double x);
-
-floating_point asin (arithmetic x);
-float          asinf(float x);
-long double    asinl(long double x);
-
-floating_point atan (arithmetic x);
-float          atanf(float x);
-long double    atanl(long double x);
-
-floating_point atan2 (arithmetic y, arithmetic x);
-float          atan2f(float y, float x);
-long double    atan2l(long double y, long double x);
-
-floating_point ceil (arithmetic x);
-float          ceilf(float x);
-long double    ceill(long double x);
-
-floating_point cos (arithmetic x);
-float          cosf(float x);
-long double    cosl(long double x);
-
-floating_point cosh (arithmetic x);
-float          coshf(float x);
-long double    coshl(long double x);
-
-floating_point exp (arithmetic x);
-float          expf(float x);
-long double    expl(long double x);
-
-floating_point fabs (arithmetic x);
-float          fabsf(float x);
-long double    fabsl(long double x);
-
-floating_point floor (arithmetic x);
-float          floorf(float x);
-long double    floorl(long double x);
-
-floating_point fmod (arithmetic x, arithmetic y);
-float          fmodf(float x, float y);
-long double    fmodl(long double x, long double y);
-
-floating_point frexp (arithmetic value, int* exp);
-float          frexpf(float value, int* exp);
-long double    frexpl(long double value, int* exp);
-
-floating_point ldexp (arithmetic value, int exp);
-float          ldexpf(float value, int exp);
-long double    ldexpl(long double value, int exp);
-
-floating_point log (arithmetic x);
-float          logf(float x);
-long double    logl(long double x);
-
-floating_point log10 (arithmetic x);
-float          log10f(float x);
-long double    log10l(long double x);
-
-floating_point modf (floating_point value, floating_point* iptr);
-float          modff(float value, float* iptr);
-long double    modfl(long double value, long double* iptr);
-
-floating_point pow (arithmetic x, arithmetic y);
-float          powf(float x, float y);
-long double    powl(long double x, long double y);
-
-floating_point sin (arithmetic x);
-float          sinf(float x);
-long double    sinl(long double x);
-
-floating_point sinh (arithmetic x);
-float          sinhf(float x);
-long double    sinhl(long double x);
-
-floating_point sqrt (arithmetic x);
-float          sqrtf(float x);
-long double    sqrtl(long double x);
-
-floating_point tan (arithmetic x);
-float          tanf(float x);
-long double    tanl(long double x);
-
-floating_point tanh (arithmetic x);
-float          tanhf(float x);
-long double    tanhl(long double x);
-
-//  C99
-
-bool signbit(arithmetic x);
-
-int fpclassify(arithmetic x);
-
-bool isfinite(arithmetic x);
-bool isinf(arithmetic x);
-bool isnan(arithmetic x);
-bool isnormal(arithmetic x);
-
-bool isgreater(arithmetic x, arithmetic y);
-bool isgreaterequal(arithmetic x, arithmetic y);
-bool isless(arithmetic x, arithmetic y);
-bool islessequal(arithmetic x, arithmetic y);
-bool islessgreater(arithmetic x, arithmetic y);
-bool isunordered(arithmetic x, arithmetic y);
-
-floating_point acosh (arithmetic x);
-float          acoshf(float x);
-long double    acoshl(long double x);
-
-floating_point asinh (arithmetic x);
-float          asinhf(float x);
-long double    asinhl(long double x);
-
-floating_point atanh (arithmetic x);
-float          atanhf(float x);
-long double    atanhl(long double x);
-
-floating_point cbrt (arithmetic x);
-float          cbrtf(float x);
-long double    cbrtl(long double x);
-
-floating_point copysign (arithmetic x, arithmetic y);
-float          copysignf(float x, float y);
-long double    copysignl(long double x, long double y);
-
-floating_point erf (arithmetic x);
-float          erff(float x);
-long double    erfl(long double x);
-
-floating_point erfc (arithmetic x);
-float          erfcf(float x);
-long double    erfcl(long double x);
-
-floating_point exp2 (arithmetic x);
-float          exp2f(float x);
-long double    exp2l(long double x);
-
-floating_point expm1 (arithmetic x);
-float          expm1f(float x);
-long double    expm1l(long double x);
-
-floating_point fdim (arithmetic x, arithmetic y);
-float          fdimf(float x, float y);
-long double    fdiml(long double x, long double y);
-
-floating_point fma (arithmetic x, arithmetic y, arithmetic z);
-float          fmaf(float x, float y, float z);
-long double    fmal(long double x, long double y, long double z);
-
-floating_point fmax (arithmetic x, arithmetic y);
-float          fmaxf(float x, float y);
-long double    fmaxl(long double x, long double y);
-
-floating_point fmin (arithmetic x, arithmetic y);
-float          fminf(float x, float y);
-long double    fminl(long double x, long double y);
-
-floating_point hypot (arithmetic x, arithmetic y);
-float          hypotf(float x, float y);
-long double    hypotl(long double x, long double y);
-
-int ilogb (arithmetic x);
-int ilogbf(float x);
-int ilogbl(long double x);
-
-floating_point lgamma (arithmetic x);
-float          lgammaf(float x);
-long double    lgammal(long double x);
-
-long long llrint (arithmetic x);
-long long llrintf(float x);
-long long llrintl(long double x);
-
-long long llround (arithmetic x);
-long long llroundf(float x);
-long long llroundl(long double x);
-
-floating_point log1p (arithmetic x);
-float          log1pf(float x);
-long double    log1pl(long double x);
-
-floating_point log2 (arithmetic x);
-float          log2f(float x);
-long double    log2l(long double x);
-
-floating_point logb (arithmetic x);
-float          logbf(float x);
-long double    logbl(long double x);
-
-long lrint (arithmetic x);
-long lrintf(float x);
-long lrintl(long double x);
-
-long lround (arithmetic x);
-long lroundf(float x);
-long lroundl(long double x);
-
-double      nan (const char* str);
-float       nanf(const char* str);
-long double nanl(const char* str);
-
-floating_point nearbyint (arithmetic x);
-float          nearbyintf(float x);
-long double    nearbyintl(long double x);
-
-floating_point nextafter (arithmetic x, arithmetic y);
-float          nextafterf(float x, float y);
-long double    nextafterl(long double x, long double y);
-
-floating_point nexttoward (arithmetic x, long double y);
-float          nexttowardf(float x, long double y);
-long double    nexttowardl(long double x, long double y);
-
-floating_point remainder (arithmetic x, arithmetic y);
-float          remainderf(float x, float y);
-long double    remainderl(long double x, long double y);
-
-floating_point remquo (arithmetic x, arithmetic y, int* pquo);
-float          remquof(float x, float y, int* pquo);
-long double    remquol(long double x, long double y, int* pquo);
-
-floating_point rint (arithmetic x);
-float          rintf(float x);
-long double    rintl(long double x);
-
-floating_point round (arithmetic x);
-float          roundf(float x);
-long double    roundl(long double x);
-
-floating_point scalbln (arithmetic x, long ex);
-float          scalblnf(float x, long ex);
-long double    scalblnl(long double x, long ex);
-
-floating_point scalbn (arithmetic x, int ex);
-float          scalbnf(float x, int ex);
-long double    scalbnl(long double x, int ex);
-
-floating_point tgamma (arithmetic x);
-float          tgammaf(float x);
-long double    tgammal(long double x);
-
-floating_point trunc (arithmetic x);
-float          truncf(float x);
-long double    truncl(long double x);
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <math.h>
-
-#ifdef __cplusplus
-
-// We support including .h headers inside 'extern "C"' contexts, so switch
-// back to C++ linkage before including these C++ headers.
-extern "C++" {
-
-#include <type_traits>
-#include <limits>
-
-// signbit
-
-#ifdef signbit
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_signbit(_A1 __lcpp_x) _NOEXCEPT
-{
-    return signbit(__lcpp_x);
-}
-
-#undef signbit
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_floating_point<_A1>::value, bool>::type
-signbit(_A1 __lcpp_x) _NOEXCEPT
-{
-    return __libcpp_signbit((typename std::__promote<_A1>::type)__lcpp_x);
-}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<
-    std::is_integral<_A1>::value && std::is_signed<_A1>::value, bool>::type
-signbit(_A1 __lcpp_x) _NOEXCEPT
-{ return __lcpp_x < 0; }
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<
-    std::is_integral<_A1>::value && !std::is_signed<_A1>::value, bool>::type
-signbit(_A1) _NOEXCEPT
-{ return false; }
-
-#elif defined(_LIBCPP_MSVCRT)
-
-template <typename _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_floating_point<_A1>::value, bool>::type
-signbit(_A1 __lcpp_x) _NOEXCEPT
-{
-  return ::signbit(static_cast<typename std::__promote<_A1>::type>(__lcpp_x));
-}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<
-    std::is_integral<_A1>::value && std::is_signed<_A1>::value, bool>::type
-signbit(_A1 __lcpp_x) _NOEXCEPT
-{ return __lcpp_x < 0; }
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<
-    std::is_integral<_A1>::value && !std::is_signed<_A1>::value, bool>::type
-signbit(_A1) _NOEXCEPT
-{ return false; }
-
-#endif  // signbit
-
-// fpclassify
-
-#ifdef fpclassify
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-int
-__libcpp_fpclassify(_A1 __lcpp_x) _NOEXCEPT
-{
-    return fpclassify(__lcpp_x);
-}
-
-#undef fpclassify
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_floating_point<_A1>::value, int>::type
-fpclassify(_A1 __lcpp_x) _NOEXCEPT
-{
-    return __libcpp_fpclassify((typename std::__promote<_A1>::type)__lcpp_x);
-}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, int>::type
-fpclassify(_A1 __lcpp_x) _NOEXCEPT
-{ return __lcpp_x == 0 ? FP_ZERO : FP_NORMAL; }
-
-#elif defined(_LIBCPP_MSVCRT)
-
-template <typename _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_floating_point<_A1>::value, bool>::type
-fpclassify(_A1 __lcpp_x) _NOEXCEPT
-{
-  return ::fpclassify(static_cast<typename std::__promote<_A1>::type>(__lcpp_x));
-}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, int>::type
-fpclassify(_A1 __lcpp_x) _NOEXCEPT
-{ return __lcpp_x == 0 ? FP_ZERO : FP_NORMAL; }
-
-#endif  // fpclassify
-
-// isfinite
-
-#ifdef isfinite
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_isfinite(_A1 __lcpp_x) _NOEXCEPT
-{
-    return isfinite(__lcpp_x);
-}
-
-#undef isfinite
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<
-    std::is_arithmetic<_A1>::value && std::numeric_limits<_A1>::has_infinity,
-    bool>::type
-isfinite(_A1 __lcpp_x) _NOEXCEPT
-{
-    return __libcpp_isfinite((typename std::__promote<_A1>::type)__lcpp_x);
-}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<
-    std::is_arithmetic<_A1>::value && !std::numeric_limits<_A1>::has_infinity,
-    bool>::type
-isfinite(_A1) _NOEXCEPT
-{ return true; }
-
-#endif  // isfinite
-
-// isinf
-
-#ifdef isinf
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_isinf(_A1 __lcpp_x) _NOEXCEPT
-{
-    return isinf(__lcpp_x);
-}
-
-#undef isinf
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<
-    std::is_arithmetic<_A1>::value && std::numeric_limits<_A1>::has_infinity,
-    bool>::type
-isinf(_A1 __lcpp_x) _NOEXCEPT
-{
-    return __libcpp_isinf((typename std::__promote<_A1>::type)__lcpp_x);
-}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<
-    std::is_arithmetic<_A1>::value && !std::numeric_limits<_A1>::has_infinity,
-    bool>::type
-isinf(_A1) _NOEXCEPT
-{ return false; }
-
-#ifdef _LIBCPP_PREFERRED_OVERLOAD
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isinf(float __lcpp_x) _NOEXCEPT { return __libcpp_isinf(__lcpp_x); }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-bool
-isinf(double __lcpp_x) _NOEXCEPT { return __libcpp_isinf(__lcpp_x); }
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isinf(long double __lcpp_x) _NOEXCEPT { return __libcpp_isinf(__lcpp_x); }
-#endif
-
-#endif  // isinf
-
-// isnan
-
-#ifdef isnan
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_isnan(_A1 __lcpp_x) _NOEXCEPT
-{
-    return isnan(__lcpp_x);
-}
-
-#undef isnan
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_floating_point<_A1>::value, bool>::type
-isnan(_A1 __lcpp_x) _NOEXCEPT
-{
-    return __libcpp_isnan((typename std::__promote<_A1>::type)__lcpp_x);
-}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, bool>::type
-isnan(_A1) _NOEXCEPT
-{ return false; }
-
-#ifdef _LIBCPP_PREFERRED_OVERLOAD
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isnan(float __lcpp_x) _NOEXCEPT { return __libcpp_isnan(__lcpp_x); }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-bool
-isnan(double __lcpp_x) _NOEXCEPT { return __libcpp_isnan(__lcpp_x); }
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-isnan(long double __lcpp_x) _NOEXCEPT { return __libcpp_isnan(__lcpp_x); }
-#endif
-
-#endif  // isnan
-
-// isnormal
-
-#ifdef isnormal
-
-template <class _A1>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_isnormal(_A1 __lcpp_x) _NOEXCEPT
-{
-    return isnormal(__lcpp_x);
-}
-
-#undef isnormal
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_floating_point<_A1>::value, bool>::type
-isnormal(_A1 __lcpp_x) _NOEXCEPT
-{
-    return __libcpp_isnormal((typename std::__promote<_A1>::type)__lcpp_x);
-}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, bool>::type
-isnormal(_A1 __lcpp_x) _NOEXCEPT
-{ return __lcpp_x != 0; }
-
-#endif  // isnormal
-
-// isgreater
-
-#ifdef isgreater
-
-template <class _A1, class _A2>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_isgreater(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    return isgreater(__lcpp_x, __lcpp_y);
-}
-
-#undef isgreater
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    bool
->::type
-isgreater(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type type;
-    return __libcpp_isgreater((type)__lcpp_x, (type)__lcpp_y);
-}
-
-#endif  // isgreater
-
-// isgreaterequal
-
-#ifdef isgreaterequal
-
-template <class _A1, class _A2>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_isgreaterequal(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    return isgreaterequal(__lcpp_x, __lcpp_y);
-}
-
-#undef isgreaterequal
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    bool
->::type
-isgreaterequal(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type type;
-    return __libcpp_isgreaterequal((type)__lcpp_x, (type)__lcpp_y);
-}
-
-#endif  // isgreaterequal
-
-// isless
-
-#ifdef isless
-
-template <class _A1, class _A2>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_isless(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    return isless(__lcpp_x, __lcpp_y);
-}
-
-#undef isless
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    bool
->::type
-isless(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type type;
-    return __libcpp_isless((type)__lcpp_x, (type)__lcpp_y);
-}
-
-#endif  // isless
-
-// islessequal
-
-#ifdef islessequal
-
-template <class _A1, class _A2>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_islessequal(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    return islessequal(__lcpp_x, __lcpp_y);
-}
-
-#undef islessequal
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    bool
->::type
-islessequal(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type type;
-    return __libcpp_islessequal((type)__lcpp_x, (type)__lcpp_y);
-}
-
-#endif  // islessequal
-
-// islessgreater
-
-#ifdef islessgreater
-
-template <class _A1, class _A2>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_islessgreater(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    return islessgreater(__lcpp_x, __lcpp_y);
-}
-
-#undef islessgreater
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    bool
->::type
-islessgreater(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type type;
-    return __libcpp_islessgreater((type)__lcpp_x, (type)__lcpp_y);
-}
-
-#endif  // islessgreater
-
-// isunordered
-
-#ifdef isunordered
-
-template <class _A1, class _A2>
-_LIBCPP_INLINE_VISIBILITY
-bool
-__libcpp_isunordered(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    return isunordered(__lcpp_x, __lcpp_y);
-}
-
-#undef isunordered
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    bool
->::type
-isunordered(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type type;
-    return __libcpp_isunordered((type)__lcpp_x, (type)__lcpp_y);
-}
-
-#endif  // isunordered
-
-// abs
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY
-float
-abs(float __lcpp_x) _NOEXCEPT {return ::fabsf(__lcpp_x);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-double
-abs(double __lcpp_x) _NOEXCEPT {return ::fabs(__lcpp_x);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-long double
-abs(long double __lcpp_x) _NOEXCEPT {return ::fabsl(__lcpp_x);}
-#endif // !(defined(_AIX) || defined(__sun__))
-
-// acos
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       acos(float __lcpp_x) _NOEXCEPT       {return ::acosf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double acos(long double __lcpp_x) _NOEXCEPT {return ::acosl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-acos(_A1 __lcpp_x) _NOEXCEPT {return ::acos((double)__lcpp_x);}
-
-// asin
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       asin(float __lcpp_x) _NOEXCEPT       {return ::asinf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double asin(long double __lcpp_x) _NOEXCEPT {return ::asinl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-asin(_A1 __lcpp_x) _NOEXCEPT {return ::asin((double)__lcpp_x);}
-
-// atan
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       atan(float __lcpp_x) _NOEXCEPT       {return ::atanf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double atan(long double __lcpp_x) _NOEXCEPT {return ::atanl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-atan(_A1 __lcpp_x) _NOEXCEPT {return ::atan((double)__lcpp_x);}
-
-// atan2
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       atan2(float __lcpp_y, float __lcpp_x) _NOEXCEPT             {return ::atan2f(__lcpp_y, __lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double atan2(long double __lcpp_y, long double __lcpp_x) _NOEXCEPT {return ::atan2l(__lcpp_y, __lcpp_x);}
-#endif
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-atan2(_A1 __lcpp_y, _A2 __lcpp_x) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::atan2((__result_type)__lcpp_y, (__result_type)__lcpp_x);
-}
-
-// ceil
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       ceil(float __lcpp_x) _NOEXCEPT       {return ::ceilf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double ceil(long double __lcpp_x) _NOEXCEPT {return ::ceill(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-ceil(_A1 __lcpp_x) _NOEXCEPT {return ::ceil((double)__lcpp_x);}
-
-// cos
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       cos(float __lcpp_x) _NOEXCEPT       {return ::cosf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double cos(long double __lcpp_x) _NOEXCEPT {return ::cosl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-cos(_A1 __lcpp_x) _NOEXCEPT {return ::cos((double)__lcpp_x);}
-
-// cosh
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       cosh(float __lcpp_x) _NOEXCEPT       {return ::coshf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double cosh(long double __lcpp_x) _NOEXCEPT {return ::coshl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-cosh(_A1 __lcpp_x) _NOEXCEPT {return ::cosh((double)__lcpp_x);}
-
-// exp
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       exp(float __lcpp_x) _NOEXCEPT       {return ::expf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double exp(long double __lcpp_x) _NOEXCEPT {return ::expl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-exp(_A1 __lcpp_x) _NOEXCEPT {return ::exp((double)__lcpp_x);}
-
-// fabs
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       fabs(float __lcpp_x) _NOEXCEPT       {return ::fabsf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double fabs(long double __lcpp_x) _NOEXCEPT {return ::fabsl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-fabs(_A1 __lcpp_x) _NOEXCEPT {return ::fabs((double)__lcpp_x);}
-
-// floor
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       floor(float __lcpp_x) _NOEXCEPT       {return ::floorf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double floor(long double __lcpp_x) _NOEXCEPT {return ::floorl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-floor(_A1 __lcpp_x) _NOEXCEPT {return ::floor((double)__lcpp_x);}
-
-// fmod
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       fmod(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::fmodf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double fmod(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::fmodl(__lcpp_x, __lcpp_y);}
-#endif
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-fmod(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::fmod((__result_type)__lcpp_x, (__result_type)__lcpp_y);
-}
-
-// frexp
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       frexp(float __lcpp_x, int* __lcpp_e) _NOEXCEPT       {return ::frexpf(__lcpp_x, __lcpp_e);}
-inline _LIBCPP_INLINE_VISIBILITY long double frexp(long double __lcpp_x, int* __lcpp_e) _NOEXCEPT {return ::frexpl(__lcpp_x, __lcpp_e);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-frexp(_A1 __lcpp_x, int* __lcpp_e) _NOEXCEPT {return ::frexp((double)__lcpp_x, __lcpp_e);}
-
-// ldexp
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       ldexp(float __lcpp_x, int __lcpp_e) _NOEXCEPT       {return ::ldexpf(__lcpp_x, __lcpp_e);}
-inline _LIBCPP_INLINE_VISIBILITY long double ldexp(long double __lcpp_x, int __lcpp_e) _NOEXCEPT {return ::ldexpl(__lcpp_x, __lcpp_e);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-ldexp(_A1 __lcpp_x, int __lcpp_e) _NOEXCEPT {return ::ldexp((double)__lcpp_x, __lcpp_e);}
-
-// log
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       log(float __lcpp_x) _NOEXCEPT       {return ::logf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double log(long double __lcpp_x) _NOEXCEPT {return ::logl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-log(_A1 __lcpp_x) _NOEXCEPT {return ::log((double)__lcpp_x);}
-
-// log10
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       log10(float __lcpp_x) _NOEXCEPT       {return ::log10f(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double log10(long double __lcpp_x) _NOEXCEPT {return ::log10l(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-log10(_A1 __lcpp_x) _NOEXCEPT {return ::log10((double)__lcpp_x);}
-
-// modf
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       modf(float __lcpp_x, float* __lcpp_y) _NOEXCEPT             {return ::modff(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double modf(long double __lcpp_x, long double* __lcpp_y) _NOEXCEPT {return ::modfl(__lcpp_x, __lcpp_y);}
-#endif
-
-// pow
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       pow(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::powf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double pow(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::powl(__lcpp_x, __lcpp_y);}
-#endif
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-pow(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::pow((__result_type)__lcpp_x, (__result_type)__lcpp_y);
-}
-
-// sin
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       sin(float __lcpp_x) _NOEXCEPT       {return ::sinf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double sin(long double __lcpp_x) _NOEXCEPT {return ::sinl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-sin(_A1 __lcpp_x) _NOEXCEPT {return ::sin((double)__lcpp_x);}
-
-// sinh
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       sinh(float __lcpp_x) _NOEXCEPT       {return ::sinhf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double sinh(long double __lcpp_x) _NOEXCEPT {return ::sinhl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-sinh(_A1 __lcpp_x) _NOEXCEPT {return ::sinh((double)__lcpp_x);}
-
-// sqrt
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       sqrt(float __lcpp_x) _NOEXCEPT       {return ::sqrtf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double sqrt(long double __lcpp_x) _NOEXCEPT {return ::sqrtl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-sqrt(_A1 __lcpp_x) _NOEXCEPT {return ::sqrt((double)__lcpp_x);}
-
-// tan
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       tan(float __lcpp_x) _NOEXCEPT       {return ::tanf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double tan(long double __lcpp_x) _NOEXCEPT {return ::tanl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-tan(_A1 __lcpp_x) _NOEXCEPT {return ::tan((double)__lcpp_x);}
-
-// tanh
-
-#if !(defined(_AIX) || defined(__sun__))
-inline _LIBCPP_INLINE_VISIBILITY float       tanh(float __lcpp_x) _NOEXCEPT       {return ::tanhf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double tanh(long double __lcpp_x) _NOEXCEPT {return ::tanhl(__lcpp_x);}
-#endif
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-tanh(_A1 __lcpp_x) _NOEXCEPT {return ::tanh((double)__lcpp_x);}
-
-// acosh
-
-inline _LIBCPP_INLINE_VISIBILITY float       acosh(float __lcpp_x) _NOEXCEPT       {return ::acoshf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double acosh(long double __lcpp_x) _NOEXCEPT {return ::acoshl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-acosh(_A1 __lcpp_x) _NOEXCEPT {return ::acosh((double)__lcpp_x);}
-
-// asinh
-
-inline _LIBCPP_INLINE_VISIBILITY float       asinh(float __lcpp_x) _NOEXCEPT       {return ::asinhf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double asinh(long double __lcpp_x) _NOEXCEPT {return ::asinhl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-asinh(_A1 __lcpp_x) _NOEXCEPT {return ::asinh((double)__lcpp_x);}
-
-// atanh
-
-inline _LIBCPP_INLINE_VISIBILITY float       atanh(float __lcpp_x) _NOEXCEPT       {return ::atanhf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double atanh(long double __lcpp_x) _NOEXCEPT {return ::atanhl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-atanh(_A1 __lcpp_x) _NOEXCEPT {return ::atanh((double)__lcpp_x);}
-
-// cbrt
-
-inline _LIBCPP_INLINE_VISIBILITY float       cbrt(float __lcpp_x) _NOEXCEPT       {return ::cbrtf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double cbrt(long double __lcpp_x) _NOEXCEPT {return ::cbrtl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-cbrt(_A1 __lcpp_x) _NOEXCEPT {return ::cbrt((double)__lcpp_x);}
-
-// copysign
-
-inline _LIBCPP_INLINE_VISIBILITY float copysign(float __lcpp_x,
-                                                float __lcpp_y) _NOEXCEPT {
-  return ::copysignf(__lcpp_x, __lcpp_y);
-}
-inline _LIBCPP_INLINE_VISIBILITY long double
-copysign(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {
-  return ::copysignl(__lcpp_x, __lcpp_y);
-}
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-copysign(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::copysign((__result_type)__lcpp_x, (__result_type)__lcpp_y);
-}
-
-// erf
-
-inline _LIBCPP_INLINE_VISIBILITY float       erf(float __lcpp_x) _NOEXCEPT       {return ::erff(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double erf(long double __lcpp_x) _NOEXCEPT {return ::erfl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-erf(_A1 __lcpp_x) _NOEXCEPT {return ::erf((double)__lcpp_x);}
-
-// erfc
-
-inline _LIBCPP_INLINE_VISIBILITY float       erfc(float __lcpp_x) _NOEXCEPT       {return ::erfcf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double erfc(long double __lcpp_x) _NOEXCEPT {return ::erfcl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-erfc(_A1 __lcpp_x) _NOEXCEPT {return ::erfc((double)__lcpp_x);}
-
-// exp2
-
-inline _LIBCPP_INLINE_VISIBILITY float       exp2(float __lcpp_x) _NOEXCEPT       {return ::exp2f(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double exp2(long double __lcpp_x) _NOEXCEPT {return ::exp2l(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-exp2(_A1 __lcpp_x) _NOEXCEPT {return ::exp2((double)__lcpp_x);}
-
-// expm1
-
-inline _LIBCPP_INLINE_VISIBILITY float       expm1(float __lcpp_x) _NOEXCEPT       {return ::expm1f(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double expm1(long double __lcpp_x) _NOEXCEPT {return ::expm1l(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-expm1(_A1 __lcpp_x) _NOEXCEPT {return ::expm1((double)__lcpp_x);}
-
-// fdim
-
-inline _LIBCPP_INLINE_VISIBILITY float       fdim(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::fdimf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double fdim(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::fdiml(__lcpp_x, __lcpp_y);}
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-fdim(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::fdim((__result_type)__lcpp_x, (__result_type)__lcpp_y);
-}
-
-// fma
-
-inline _LIBCPP_INLINE_VISIBILITY float       fma(float __lcpp_x, float __lcpp_y, float __lcpp_z) _NOEXCEPT                   {return ::fmaf(__lcpp_x, __lcpp_y, __lcpp_z);}
-inline _LIBCPP_INLINE_VISIBILITY long double fma(long double __lcpp_x, long double __lcpp_y, long double __lcpp_z) _NOEXCEPT {return ::fmal(__lcpp_x, __lcpp_y, __lcpp_z);}
-
-template <class _A1, class _A2, class _A3>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value &&
-    std::is_arithmetic<_A3>::value,
-    std::__promote<_A1, _A2, _A3>
->::type
-fma(_A1 __lcpp_x, _A2 __lcpp_y, _A3 __lcpp_z) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2, _A3>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value &&
-                     std::is_same<_A3, __result_type>::value)), "");
-    return ::fma((__result_type)__lcpp_x, (__result_type)__lcpp_y, (__result_type)__lcpp_z);
-}
-
-// fmax
-
-inline _LIBCPP_INLINE_VISIBILITY float       fmax(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::fmaxf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double fmax(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::fmaxl(__lcpp_x, __lcpp_y);}
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-fmax(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::fmax((__result_type)__lcpp_x, (__result_type)__lcpp_y);
-}
-
-// fmin
-
-inline _LIBCPP_INLINE_VISIBILITY float       fmin(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::fminf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double fmin(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::fminl(__lcpp_x, __lcpp_y);}
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-fmin(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::fmin((__result_type)__lcpp_x, (__result_type)__lcpp_y);
-}
-
-// hypot
-
-inline _LIBCPP_INLINE_VISIBILITY float       hypot(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::hypotf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double hypot(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::hypotl(__lcpp_x, __lcpp_y);}
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-hypot(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::hypot((__result_type)__lcpp_x, (__result_type)__lcpp_y);
-}
-
-// ilogb
-
-inline _LIBCPP_INLINE_VISIBILITY int ilogb(float __lcpp_x) _NOEXCEPT       {return ::ilogbf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY int ilogb(long double __lcpp_x) _NOEXCEPT {return ::ilogbl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, int>::type
-ilogb(_A1 __lcpp_x) _NOEXCEPT {return ::ilogb((double)__lcpp_x);}
-
-// lgamma
-
-inline _LIBCPP_INLINE_VISIBILITY float       lgamma(float __lcpp_x) _NOEXCEPT       {return ::lgammaf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double lgamma(long double __lcpp_x) _NOEXCEPT {return ::lgammal(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-lgamma(_A1 __lcpp_x) _NOEXCEPT {return ::lgamma((double)__lcpp_x);}
-
-// llrint
-
-inline _LIBCPP_INLINE_VISIBILITY long long llrint(float __lcpp_x) _NOEXCEPT       {return ::llrintf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long long llrint(long double __lcpp_x) _NOEXCEPT {return ::llrintl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, long long>::type
-llrint(_A1 __lcpp_x) _NOEXCEPT {return ::llrint((double)__lcpp_x);}
-
-// llround
-
-inline _LIBCPP_INLINE_VISIBILITY long long llround(float __lcpp_x) _NOEXCEPT       {return ::llroundf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long long llround(long double __lcpp_x) _NOEXCEPT {return ::llroundl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, long long>::type
-llround(_A1 __lcpp_x) _NOEXCEPT {return ::llround((double)__lcpp_x);}
-
-// log1p
-
-inline _LIBCPP_INLINE_VISIBILITY float       log1p(float __lcpp_x) _NOEXCEPT       {return ::log1pf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double log1p(long double __lcpp_x) _NOEXCEPT {return ::log1pl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-log1p(_A1 __lcpp_x) _NOEXCEPT {return ::log1p((double)__lcpp_x);}
-
-// log2
-
-inline _LIBCPP_INLINE_VISIBILITY float       log2(float __lcpp_x) _NOEXCEPT       {return ::log2f(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double log2(long double __lcpp_x) _NOEXCEPT {return ::log2l(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-log2(_A1 __lcpp_x) _NOEXCEPT {return ::log2((double)__lcpp_x);}
-
-// logb
-
-inline _LIBCPP_INLINE_VISIBILITY float       logb(float __lcpp_x) _NOEXCEPT       {return ::logbf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double logb(long double __lcpp_x) _NOEXCEPT {return ::logbl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-logb(_A1 __lcpp_x) _NOEXCEPT {return ::logb((double)__lcpp_x);}
-
-// lrint
-
-inline _LIBCPP_INLINE_VISIBILITY long lrint(float __lcpp_x) _NOEXCEPT       {return ::lrintf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long lrint(long double __lcpp_x) _NOEXCEPT {return ::lrintl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, long>::type
-lrint(_A1 __lcpp_x) _NOEXCEPT {return ::lrint((double)__lcpp_x);}
-
-// lround
-
-inline _LIBCPP_INLINE_VISIBILITY long lround(float __lcpp_x) _NOEXCEPT       {return ::lroundf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long lround(long double __lcpp_x) _NOEXCEPT {return ::lroundl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, long>::type
-lround(_A1 __lcpp_x) _NOEXCEPT {return ::lround((double)__lcpp_x);}
-
-// nan
-
-// nearbyint
-
-inline _LIBCPP_INLINE_VISIBILITY float       nearbyint(float __lcpp_x) _NOEXCEPT       {return ::nearbyintf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double nearbyint(long double __lcpp_x) _NOEXCEPT {return ::nearbyintl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-nearbyint(_A1 __lcpp_x) _NOEXCEPT {return ::nearbyint((double)__lcpp_x);}
-
-// nextafter
-
-inline _LIBCPP_INLINE_VISIBILITY float       nextafter(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::nextafterf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double nextafter(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::nextafterl(__lcpp_x, __lcpp_y);}
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-nextafter(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::nextafter((__result_type)__lcpp_x, (__result_type)__lcpp_y);
-}
-
-// nexttoward
-
-inline _LIBCPP_INLINE_VISIBILITY float       nexttoward(float __lcpp_x, long double __lcpp_y) _NOEXCEPT       {return ::nexttowardf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double nexttoward(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::nexttowardl(__lcpp_x, __lcpp_y);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-nexttoward(_A1 __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::nexttoward((double)__lcpp_x, __lcpp_y);}
-
-// remainder
-
-inline _LIBCPP_INLINE_VISIBILITY float       remainder(float __lcpp_x, float __lcpp_y) _NOEXCEPT             {return ::remainderf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double remainder(long double __lcpp_x, long double __lcpp_y) _NOEXCEPT {return ::remainderl(__lcpp_x, __lcpp_y);}
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-remainder(_A1 __lcpp_x, _A2 __lcpp_y) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::remainder((__result_type)__lcpp_x, (__result_type)__lcpp_y);
-}
-
-// remquo
-
-inline _LIBCPP_INLINE_VISIBILITY float       remquo(float __lcpp_x, float __lcpp_y, int* __lcpp_z) _NOEXCEPT             {return ::remquof(__lcpp_x, __lcpp_y, __lcpp_z);}
-inline _LIBCPP_INLINE_VISIBILITY long double remquo(long double __lcpp_x, long double __lcpp_y, int* __lcpp_z) _NOEXCEPT {return ::remquol(__lcpp_x, __lcpp_y, __lcpp_z);}
-
-template <class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::__lazy_enable_if
-<
-    std::is_arithmetic<_A1>::value &&
-    std::is_arithmetic<_A2>::value,
-    std::__promote<_A1, _A2>
->::type
-remquo(_A1 __lcpp_x, _A2 __lcpp_y, int* __lcpp_z) _NOEXCEPT
-{
-    typedef typename std::__promote<_A1, _A2>::type __result_type;
-    static_assert((!(std::is_same<_A1, __result_type>::value &&
-                     std::is_same<_A2, __result_type>::value)), "");
-    return ::remquo((__result_type)__lcpp_x, (__result_type)__lcpp_y, __lcpp_z);
-}
-
-// rint
-
-inline _LIBCPP_INLINE_VISIBILITY float       rint(float __lcpp_x) _NOEXCEPT       {return ::rintf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double rint(long double __lcpp_x) _NOEXCEPT {return ::rintl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-rint(_A1 __lcpp_x) _NOEXCEPT {return ::rint((double)__lcpp_x);}
-
-// round
-
-inline _LIBCPP_INLINE_VISIBILITY float       round(float __lcpp_x) _NOEXCEPT       {return ::roundf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double round(long double __lcpp_x) _NOEXCEPT {return ::roundl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-round(_A1 __lcpp_x) _NOEXCEPT {return ::round((double)__lcpp_x);}
-
-// scalbln
-
-inline _LIBCPP_INLINE_VISIBILITY float       scalbln(float __lcpp_x, long __lcpp_y) _NOEXCEPT       {return ::scalblnf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double scalbln(long double __lcpp_x, long __lcpp_y) _NOEXCEPT {return ::scalblnl(__lcpp_x, __lcpp_y);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-scalbln(_A1 __lcpp_x, long __lcpp_y) _NOEXCEPT {return ::scalbln((double)__lcpp_x, __lcpp_y);}
-
-// scalbn
-
-inline _LIBCPP_INLINE_VISIBILITY float       scalbn(float __lcpp_x, int __lcpp_y) _NOEXCEPT       {return ::scalbnf(__lcpp_x, __lcpp_y);}
-inline _LIBCPP_INLINE_VISIBILITY long double scalbn(long double __lcpp_x, int __lcpp_y) _NOEXCEPT {return ::scalbnl(__lcpp_x, __lcpp_y);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-scalbn(_A1 __lcpp_x, int __lcpp_y) _NOEXCEPT {return ::scalbn((double)__lcpp_x, __lcpp_y);}
-
-// tgamma
-
-inline _LIBCPP_INLINE_VISIBILITY float       tgamma(float __lcpp_x) _NOEXCEPT       {return ::tgammaf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double tgamma(long double __lcpp_x) _NOEXCEPT {return ::tgammal(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-tgamma(_A1 __lcpp_x) _NOEXCEPT {return ::tgamma((double)__lcpp_x);}
-
-// trunc
-
-inline _LIBCPP_INLINE_VISIBILITY float       trunc(float __lcpp_x) _NOEXCEPT       {return ::truncf(__lcpp_x);}
-inline _LIBCPP_INLINE_VISIBILITY long double trunc(long double __lcpp_x) _NOEXCEPT {return ::truncl(__lcpp_x);}
-
-template <class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-typename std::enable_if<std::is_integral<_A1>::value, double>::type
-trunc(_A1 __lcpp_x) _NOEXCEPT {return ::trunc((double)__lcpp_x);}
-
-} // extern "C++"
-
-#endif // __cplusplus
-
-#else // _LIBCPP_MATH_H
-
-// This include lives outside the header guard in order to support an MSVC
-// extension which allows users to do:
-//
-// #define _USE_MATH_DEFINES
-// #include <math.h>
-//
-// and receive the definitions of mathematical constants, even if <math.h>
-// has previously been included.
-#if defined(_LIBCPP_MSVCRT) && defined(_USE_MATH_DEFINES)
-#include_next <math.h>
-#endif
-
-#endif  // _LIBCPP_MATH_H
diff --git a/lib/libcxx/include/memory b/lib/libcxx/include/memory
deleted file mode 100644
index ce2c3576623..00000000000
--- a/lib/libcxx/include/memory
+++ /dev/null
@@ -1,5676 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- memory ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_MEMORY
-#define _LIBCPP_MEMORY
-
-/*
-    memory synopsis
-
-namespace std
-{
-
-struct allocator_arg_t { };
-inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();
-
-template <class T, class Alloc> struct uses_allocator;
-
-template <class Ptr>
-struct pointer_traits
-{
-    typedef Ptr pointer;
-    typedef <details> element_type;
-    typedef <details> difference_type;
-
-    template <class U> using rebind = <details>;
-
-    static pointer pointer_to(<details>);
-};
-
-template <class T>
-struct pointer_traits<T*>
-{
-    typedef T* pointer;
-    typedef T element_type;
-    typedef ptrdiff_t difference_type;
-
-    template <class U> using rebind = U*;
-
-    static pointer pointer_to(<details>) noexcept; // constexpr in C++20
-};
-
-template <class T> constexpr T* to_address(T* p) noexcept; // C++20
-template <class Ptr> auto to_address(const Ptr& p) noexcept; // C++20
-
-template <class Alloc>
-struct allocator_traits
-{
-    typedef Alloc                        allocator_type;
-    typedef typename allocator_type::value_type
-                                         value_type;
-
-    typedef Alloc::pointer | value_type* pointer;
-    typedef Alloc::const_pointer
-          | pointer_traits<pointer>::rebind<const value_type>
-                                         const_pointer;
-    typedef Alloc::void_pointer
-          | pointer_traits<pointer>::rebind<void>
-                                         void_pointer;
-    typedef Alloc::const_void_pointer
-          | pointer_traits<pointer>::rebind<const void>
-                                         const_void_pointer;
-    typedef Alloc::difference_type
-          | pointer_traits<pointer>::difference_type
-                                         difference_type;
-    typedef Alloc::size_type
-          | make_unsigned<difference_type>::type
-                                         size_type;
-    typedef Alloc::propagate_on_container_copy_assignment
-          | false_type                   propagate_on_container_copy_assignment;
-    typedef Alloc::propagate_on_container_move_assignment
-          | false_type                   propagate_on_container_move_assignment;
-    typedef Alloc::propagate_on_container_swap
-          | false_type                   propagate_on_container_swap;
-    typedef Alloc::is_always_equal
-          | is_empty                     is_always_equal;
-
-    template <class T> using rebind_alloc  = Alloc::rebind<U>::other | Alloc<T, Args...>;
-    template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
-
-    static pointer allocate(allocator_type& a, size_type n);                          // [[nodiscard]] in C++20
-    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint); // [[nodiscard]] in C++20
-
-    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept;
-
-    template <class T, class... Args>
-        static void construct(allocator_type& a, T* p, Args&&... args);
-
-    template <class T>
-        static void destroy(allocator_type& a, T* p);
-
-    static size_type max_size(const allocator_type& a); // noexcept in C++14
-
-    static allocator_type
-        select_on_container_copy_construction(const allocator_type& a);
-};
-
-template <>
-class allocator<void>
-{
-public:
-    typedef void*                                 pointer;
-    typedef const void*                           const_pointer;
-    typedef void                                  value_type;
-
-    template <class _Up> struct rebind {typedef allocator<_Up> other;};
-};
-
-template <class T>
-class allocator
-{
-public:
-    typedef size_t                                size_type;
-    typedef ptrdiff_t                             difference_type;
-    typedef T*                                    pointer;
-    typedef const T*                              const_pointer;
-    typedef typename add_lvalue_reference<T>::type       reference;
-    typedef typename add_lvalue_reference<const T>::type const_reference;
-    typedef T                                     value_type;
-
-    template <class U> struct rebind {typedef allocator<U> other;};
-
-    constexpr allocator() noexcept;                      // constexpr in C++20
-    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
-    template <class U>
-      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
-    ~allocator();
-    pointer address(reference x) const noexcept;
-    const_pointer address(const_reference x) const noexcept;
-    pointer allocate(size_type, allocator<void>::const_pointer hint = 0);
-    void deallocate(pointer p, size_type n) noexcept;
-    size_type max_size() const noexcept;
-    template<class U, class... Args>
-        void construct(U* p, Args&&... args);
-    template <class U>
-        void destroy(U* p);
-};
-
-template <class T, class U>
-bool operator==(const allocator<T>&, const allocator<U>&) noexcept;
-
-template <class T, class U>
-bool operator!=(const allocator<T>&, const allocator<U>&) noexcept;
-
-template <class OutputIterator, class T>
-class raw_storage_iterator
-    : public iterator<output_iterator_tag,
-                      T,                               // purposefully not C++03
-                      ptrdiff_t,                       // purposefully not C++03
-                      T*,                              // purposefully not C++03
-                      raw_storage_iterator&>           // purposefully not C++03
-{
-public:
-    explicit raw_storage_iterator(OutputIterator x);
-    raw_storage_iterator& operator*();
-    raw_storage_iterator& operator=(const T& element);
-    raw_storage_iterator& operator++();
-    raw_storage_iterator  operator++(int);
-};
-
-template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
-template <class T> void               return_temporary_buffer(T* p) noexcept;
-
-template <class T> T* addressof(T& r) noexcept;
-template <class T> T* addressof(const T&& r) noexcept = delete;
-
-template <class InputIterator, class ForwardIterator>
-ForwardIterator
-uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
-
-template <class InputIterator, class Size, class ForwardIterator>
-ForwardIterator
-uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
-
-template <class ForwardIterator, class T>
-void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
-
-template <class ForwardIterator, class Size, class T>
-ForwardIterator
-uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
-
-template <class T>
-void destroy_at(T* location);
-
-template <class ForwardIterator>
- void destroy(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class Size>
- ForwardIterator destroy_n(ForwardIterator first, Size n);
-
-template <class InputIterator, class ForwardIterator>
- ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
-
-template <class InputIterator, class Size, class ForwardIterator>
- pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
-
-template <class ForwardIterator>
- void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class Size>
- ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
-
-template <class ForwardIterator>
- void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
-
-template <class ForwardIterator, class Size>
- ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
-
-template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
-
-template<class X>
-class auto_ptr                                  // deprecated in C++11, removed in C++17
-{
-public:
-    typedef X element_type;
-
-    explicit auto_ptr(X* p =0) throw();
-    auto_ptr(auto_ptr&) throw();
-    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
-    auto_ptr& operator=(auto_ptr&) throw();
-    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
-    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
-    ~auto_ptr() throw();
-
-    typename add_lvalue_reference<X>::type operator*() const throw();
-    X* operator->() const throw();
-    X* get() const throw();
-    X* release() throw();
-    void reset(X* p =0) throw();
-
-    auto_ptr(auto_ptr_ref<X>) throw();
-    template<class Y> operator auto_ptr_ref<Y>() throw();
-    template<class Y> operator auto_ptr<Y>() throw();
-};
-
-template <class T>
-struct default_delete
-{
-    constexpr default_delete() noexcept = default;
-    template <class U> default_delete(const default_delete<U>&) noexcept;
-
-    void operator()(T*) const noexcept;
-};
-
-template <class T>
-struct default_delete<T[]>
-{
-    constexpr default_delete() noexcept = default;
-    void operator()(T*) const noexcept;
-    template <class U> void operator()(U*) const = delete;
-};
-
-template <class T, class D = default_delete<T>>
-class unique_ptr
-{
-public:
-    typedef see below pointer;
-    typedef T element_type;
-    typedef D deleter_type;
-
-    // constructors
-    constexpr unique_ptr() noexcept;
-    explicit unique_ptr(pointer p) noexcept;
-    unique_ptr(pointer p, see below d1) noexcept;
-    unique_ptr(pointer p, see below d2) noexcept;
-    unique_ptr(unique_ptr&& u) noexcept;
-    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
-    template <class U, class E>
-        unique_ptr(unique_ptr<U, E>&& u) noexcept;
-    template <class U>
-        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
-
-    // destructor
-    ~unique_ptr();
-
-    // assignment
-    unique_ptr& operator=(unique_ptr&& u) noexcept;
-    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
-    unique_ptr& operator=(nullptr_t) noexcept;
-
-    // observers
-    typename add_lvalue_reference<T>::type operator*() const;
-    pointer operator->() const noexcept;
-    pointer get() const noexcept;
-    deleter_type& get_deleter() noexcept;
-    const deleter_type& get_deleter() const noexcept;
-    explicit operator bool() const noexcept;
-
-    // modifiers
-    pointer release() noexcept;
-    void reset(pointer p = pointer()) noexcept;
-    void swap(unique_ptr& u) noexcept;
-};
-
-template <class T, class D>
-class unique_ptr<T[], D>
-{
-public:
-    typedef implementation-defined pointer;
-    typedef T element_type;
-    typedef D deleter_type;
-
-    // constructors
-    constexpr unique_ptr() noexcept;
-    explicit unique_ptr(pointer p) noexcept;
-    unique_ptr(pointer p, see below d) noexcept;
-    unique_ptr(pointer p, see below d) noexcept;
-    unique_ptr(unique_ptr&& u) noexcept;
-    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
-
-    // destructor
-    ~unique_ptr();
-
-    // assignment
-    unique_ptr& operator=(unique_ptr&& u) noexcept;
-    unique_ptr& operator=(nullptr_t) noexcept;
-
-    // observers
-    T& operator[](size_t i) const;
-    pointer get() const noexcept;
-    deleter_type& get_deleter() noexcept;
-    const deleter_type& get_deleter() const noexcept;
-    explicit operator bool() const noexcept;
-
-    // modifiers
-    pointer release() noexcept;
-    void reset(pointer p = pointer()) noexcept;
-    void reset(nullptr_t) noexcept;
-    template <class U> void reset(U) = delete;
-    void swap(unique_ptr& u) noexcept;
-};
-
-template <class T, class D>
-    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
-
-template <class T1, class D1, class T2, class D2>
-    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template <class T1, class D1, class T2, class D2>
-    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template <class T1, class D1, class T2, class D2>
-    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template <class T1, class D1, class T2, class D2>
-    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template <class T1, class D1, class T2, class D2>
-    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-template <class T1, class D1, class T2, class D2>
-    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
-
-template <class T, class D>
-    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
-template <class T, class D>
-    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
-template <class T, class D>
-    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
-template <class T, class D>
-    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
-
-template <class T, class D>
-    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
-template <class T, class D>
-    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
-template <class T, class D>
-    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
-template <class T, class D>
-    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
-template <class T, class D>
-    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
-template <class T, class D>
-    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
-template <class T, class D>
-    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
-template <class T, class D>
-    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
-
-class bad_weak_ptr
-    : public std::exception
-{
-    bad_weak_ptr() noexcept;
-};
-
-template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
-template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
-template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
-
-template<class E, class T, class Y, class D>
-    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
-
-template<class T>
-class shared_ptr
-{
-public:
-    typedef T element_type;
-    typedef weak_ptr<T> weak_type; // C++17
-
-    // constructors:
-    constexpr shared_ptr() noexcept;
-    template<class Y> explicit shared_ptr(Y* p);
-    template<class Y, class D> shared_ptr(Y* p, D d);
-    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
-    template <class D> shared_ptr(nullptr_t p, D d);
-    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
-    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
-    shared_ptr(const shared_ptr& r) noexcept;
-    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
-    shared_ptr(shared_ptr&& r) noexcept;
-    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
-    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
-    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
-    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
-    shared_ptr(nullptr_t) : shared_ptr() { }
-
-    // destructor:
-    ~shared_ptr();
-
-    // assignment:
-    shared_ptr& operator=(const shared_ptr& r) noexcept;
-    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
-    shared_ptr& operator=(shared_ptr&& r) noexcept;
-    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
-    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
-    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
-
-    // modifiers:
-    void swap(shared_ptr& r) noexcept;
-    void reset() noexcept;
-    template<class Y> void reset(Y* p);
-    template<class Y, class D> void reset(Y* p, D d);
-    template<class Y, class D, class A> void reset(Y* p, D d, A a);
-
-    // observers:
-    T* get() const noexcept;
-    T& operator*() const noexcept;
-    T* operator->() const noexcept;
-    long use_count() const noexcept;
-    bool unique() const noexcept;
-    explicit operator bool() const noexcept;
-    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
-    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
-};
-
-// shared_ptr comparisons:
-template<class T, class U>
-    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
-template<class T, class U>
-    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
-template<class T, class U>
-    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
-template<class T, class U>
-    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
-template<class T, class U>
-    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
-template<class T, class U>
-    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
-
-template <class T>
-    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
-template <class T>
-    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
-template <class T>
-    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
-template <class T>
-    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
-template <class T>
-    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
-template <class T>
-bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
-template <class T>
-    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
-template <class T>
-    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
-template <class T>
-    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
-template <class T>
-    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
-template <class T>
-    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
-template <class T>
-    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
-
-// shared_ptr specialized algorithms:
-template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
-
-// shared_ptr casts:
-template<class T, class U>
-    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
-template<class T, class U>
-    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
-template<class T, class U>
-    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
-
-// shared_ptr I/O:
-template<class E, class T, class Y>
-    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
-
-// shared_ptr get_deleter:
-template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
-
-template<class T, class... Args>
-    shared_ptr<T> make_shared(Args&&... args);
-template<class T, class A, class... Args>
-    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
-
-template<class T>
-class weak_ptr
-{
-public:
-    typedef T element_type;
-
-    // constructors
-    constexpr weak_ptr() noexcept;
-    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
-    weak_ptr(weak_ptr const& r) noexcept;
-    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
-    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
-    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
-
-    // destructor
-    ~weak_ptr();
-
-    // assignment
-    weak_ptr& operator=(weak_ptr const& r) noexcept;
-    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
-    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
-    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
-    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
-
-    // modifiers
-    void swap(weak_ptr& r) noexcept;
-    void reset() noexcept;
-
-    // observers
-    long use_count() const noexcept;
-    bool expired() const noexcept;
-    shared_ptr<T> lock() const noexcept;
-    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
-    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
-};
-
-// weak_ptr specialized algorithms:
-template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
-
-// class owner_less:
-template<class T> struct owner_less;
-
-template<class T>
-struct owner_less<shared_ptr<T>>
-    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
-{
-    typedef bool result_type;
-    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
-    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
-    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
-};
-
-template<class T>
-struct owner_less<weak_ptr<T>>
-    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
-{
-    typedef bool result_type;
-    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
-    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
-    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
-};
-
-template <>  // Added in C++14
-struct owner_less<void>
-{
-    template <class _Tp, class _Up>
-    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
-    template <class _Tp, class _Up>
-    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
-    template <class _Tp, class _Up>
-    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
-    template <class _Tp, class _Up>
-    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
-
-    typedef void is_transparent;
-};
-
-template<class T>
-class enable_shared_from_this
-{
-protected:
-    constexpr enable_shared_from_this() noexcept;
-    enable_shared_from_this(enable_shared_from_this const&) noexcept;
-    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
-    ~enable_shared_from_this();
-public:
-    shared_ptr<T> shared_from_this();
-    shared_ptr<T const> shared_from_this() const;
-};
-
-template<class T>
-    bool atomic_is_lock_free(const shared_ptr<T>* p);
-template<class T>
-    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
-template<class T>
-    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
-template<class T>
-    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
-template<class T>
-    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
-template<class T>
-    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
-template<class T>
-    shared_ptr<T>
-    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
-template<class T>
-    bool
-    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
-template<class T>
-    bool
-    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
-template<class T>
-    bool
-    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
-                                          shared_ptr<T> w, memory_order success,
-                                          memory_order failure);
-template<class T>
-    bool
-    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
-                                            shared_ptr<T> w, memory_order success,
-                                            memory_order failure);
-// Hash support
-template <class T> struct hash;
-template <class T, class D> struct hash<unique_ptr<T, D> >;
-template <class T> struct hash<shared_ptr<T> >;
-
-template <class T, class Alloc>
-  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
-
-// Pointer safety
-enum class pointer_safety { relaxed, preferred, strict };
-void declare_reachable(void *p);
-template <class T> T *undeclare_reachable(T *p);
-void declare_no_pointers(char *p, size_t n);
-void undeclare_no_pointers(char *p, size_t n);
-pointer_safety get_pointer_safety() noexcept;
-
-void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <type_traits>
-#include <typeinfo>
-#include <cstddef>
-#include <cstdint>
-#include <new>
-#include <utility>
-#include <limits>
-#include <iterator>
-#include <__functional_base>
-#include <iosfwd>
-#include <tuple>
-#include <stdexcept>
-#include <cstring>
-#include <cassert>
-#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
-#  include <atomic>
-#endif
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
-#if !defined(_LIBCPP_HAS_NO_THREADS) && \
-    defined(__ATOMIC_RELAXED) &&        \
-    (__has_builtin(__atomic_load_n) || _GNUC_VER >= 407)
-    return __atomic_load_n(__value, __ATOMIC_RELAXED);
-#else
-    return *__value;
-#endif
-}
-
-template <class _ValueType>
-inline _LIBCPP_INLINE_VISIBILITY
-_ValueType __libcpp_acquire_load(_ValueType const* __value) {
-#if !defined(_LIBCPP_HAS_NO_THREADS) && \
-    defined(__ATOMIC_ACQUIRE) &&        \
-    (__has_builtin(__atomic_load_n) || _GNUC_VER >= 407)
-    return __atomic_load_n(__value, __ATOMIC_ACQUIRE);
-#else
-    return *__value;
-#endif
-}
-
-// addressof moved to <type_traits>
-
-template <class _Tp> class allocator;
-
-template <>
-class _LIBCPP_TEMPLATE_VIS allocator<void>
-{
-public:
-    typedef void*             pointer;
-    typedef const void*       const_pointer;
-    typedef void              value_type;
-
-    template <class _Up> struct rebind {typedef allocator<_Up> other;};
-};
-
-template <>
-class _LIBCPP_TEMPLATE_VIS allocator<const void>
-{
-public:
-    typedef const void*       pointer;
-    typedef const void*       const_pointer;
-    typedef const void        value_type;
-
-    template <class _Up> struct rebind {typedef allocator<_Up> other;};
-};
-
-// pointer_traits
-
-template <class _Tp, class = void>
-struct __has_element_type : false_type {};
-
-template <class _Tp>
-struct __has_element_type<_Tp,
-              typename __void_t<typename _Tp::element_type>::type> : true_type {};
-
-template <class _Ptr, bool = __has_element_type<_Ptr>::value>
-struct __pointer_traits_element_type;
-
-template <class _Ptr>
-struct __pointer_traits_element_type<_Ptr, true>
-{
-    typedef typename _Ptr::element_type type;
-};
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-template <template <class, class...> class _Sp, class _Tp, class ..._Args>
-struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
-{
-    typedef typename _Sp<_Tp, _Args...>::element_type type;
-};
-
-template <template <class, class...> class _Sp, class _Tp, class ..._Args>
-struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
-{
-    typedef _Tp type;
-};
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-template <template <class> class _Sp, class _Tp>
-struct __pointer_traits_element_type<_Sp<_Tp>, true>
-{
-    typedef typename _Sp<_Tp>::element_type type;
-};
-
-template <template <class> class _Sp, class _Tp>
-struct __pointer_traits_element_type<_Sp<_Tp>, false>
-{
-    typedef _Tp type;
-};
-
-template <template <class, class> class _Sp, class _Tp, class _A0>
-struct __pointer_traits_element_type<_Sp<_Tp, _A0>, true>
-{
-    typedef typename _Sp<_Tp, _A0>::element_type type;
-};
-
-template <template <class, class> class _Sp, class _Tp, class _A0>
-struct __pointer_traits_element_type<_Sp<_Tp, _A0>, false>
-{
-    typedef _Tp type;
-};
-
-template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
-struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, true>
-{
-    typedef typename _Sp<_Tp, _A0, _A1>::element_type type;
-};
-
-template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
-struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, false>
-{
-    typedef _Tp type;
-};
-
-template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
-                                                           class _A1, class _A2>
-struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, true>
-{
-    typedef typename _Sp<_Tp, _A0, _A1, _A2>::element_type type;
-};
-
-template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
-                                                           class _A1, class _A2>
-struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, false>
-{
-    typedef _Tp type;
-};
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Tp, class = void>
-struct __has_difference_type : false_type {};
-
-template <class _Tp>
-struct __has_difference_type<_Tp,
-            typename __void_t<typename _Tp::difference_type>::type> : true_type {};
-
-template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
-struct __pointer_traits_difference_type
-{
-    typedef ptrdiff_t type;
-};
-
-template <class _Ptr>
-struct __pointer_traits_difference_type<_Ptr, true>
-{
-    typedef typename _Ptr::difference_type type;
-};
-
-template <class _Tp, class _Up>
-struct __has_rebind
-{
-private:
-    struct __two {char __lx; char __lxx;};
-    template <class _Xp> static __two __test(...);
-    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
-public:
-    static const bool value = sizeof(__test<_Tp>(0)) == 1;
-};
-
-template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
-struct __pointer_traits_rebind
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename _Tp::template rebind<_Up> type;
-#else
-    typedef typename _Tp::template rebind<_Up>::other type;
-#endif
-};
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
-#else
-    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
-#endif
-};
-
-template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
-{
-    typedef _Sp<_Up, _Args...> type;
-};
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-template <template <class> class _Sp, class _Tp, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp>, _Up, true>
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename _Sp<_Tp>::template rebind<_Up> type;
-#else
-    typedef typename _Sp<_Tp>::template rebind<_Up>::other type;
-#endif
-};
-
-template <template <class> class _Sp, class _Tp, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp>, _Up, false>
-{
-    typedef _Sp<_Up> type;
-};
-
-template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, true>
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename _Sp<_Tp, _A0>::template rebind<_Up> type;
-#else
-    typedef typename _Sp<_Tp, _A0>::template rebind<_Up>::other type;
-#endif
-};
-
-template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, false>
-{
-    typedef _Sp<_Up, _A0> type;
-};
-
-template <template <class, class, class> class _Sp, class _Tp, class _A0,
-                                         class _A1, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, true>
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up> type;
-#else
-    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up>::other type;
-#endif
-};
-
-template <template <class, class, class> class _Sp, class _Tp, class _A0,
-                                         class _A1, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, false>
-{
-    typedef _Sp<_Up, _A0, _A1> type;
-};
-
-template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
-                                                class _A1, class _A2, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, true>
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up> type;
-#else
-    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
-#endif
-};
-
-template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
-                                                class _A1, class _A2, class _Up>
-struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, false>
-{
-    typedef _Sp<_Up, _A0, _A1, _A2> type;
-};
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Ptr>
-struct _LIBCPP_TEMPLATE_VIS pointer_traits
-{
-    typedef _Ptr                                                     pointer;
-    typedef typename __pointer_traits_element_type<pointer>::type    element_type;
-    typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
-#else
-    template <class _Up> struct rebind
-        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
-#endif  // _LIBCPP_CXX03_LANG
-
-private:
-    struct __nat {};
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    static pointer pointer_to(typename conditional<is_void<element_type>::value,
-                                           __nat, element_type>::type& __r)
-        {return pointer::pointer_to(__r);}
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS pointer_traits<_Tp*>
-{
-    typedef _Tp*      pointer;
-    typedef _Tp       element_type;
-    typedef ptrdiff_t difference_type;
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Up> using rebind = _Up*;
-#else
-    template <class _Up> struct rebind {typedef _Up* other;};
-#endif
-
-private:
-    struct __nat {};
-public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-    static pointer pointer_to(typename conditional<is_void<element_type>::value,
-                                      __nat, element_type>::type& __r) _NOEXCEPT
-        {return _VSTD::addressof(__r);}
-};
-
-template <class _From, class _To>
-struct __rebind_pointer {
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename pointer_traits<_From>::template rebind<_To>        type;
-#else
-    typedef typename pointer_traits<_From>::template rebind<_To>::other type;
-#endif
-};
-
-// allocator_traits
-
-template <class _Tp, class = void>
-struct __has_pointer_type : false_type {};
-
-template <class _Tp>
-struct __has_pointer_type<_Tp,
-          typename __void_t<typename _Tp::pointer>::type> : true_type {};
-
-namespace __pointer_type_imp
-{
-
-template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
-struct __pointer_type
-{
-    typedef typename _Dp::pointer type;
-};
-
-template <class _Tp, class _Dp>
-struct __pointer_type<_Tp, _Dp, false>
-{
-    typedef _Tp* type;
-};
-
-}  // __pointer_type_imp
-
-template <class _Tp, class _Dp>
-struct __pointer_type
-{
-    typedef typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
-};
-
-template <class _Tp, class = void>
-struct __has_const_pointer : false_type {};
-
-template <class _Tp>
-struct __has_const_pointer<_Tp,
-            typename __void_t<typename _Tp::const_pointer>::type> : true_type {};
-
-template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
-struct __const_pointer
-{
-    typedef typename _Alloc::const_pointer type;
-};
-
-template <class _Tp, class _Ptr, class _Alloc>
-struct __const_pointer<_Tp, _Ptr, _Alloc, false>
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
-#else
-    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
-#endif
-};
-
-template <class _Tp, class = void>
-struct __has_void_pointer : false_type {};
-
-template <class _Tp>
-struct __has_void_pointer<_Tp,
-               typename __void_t<typename _Tp::void_pointer>::type> : true_type {};
-
-template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
-struct __void_pointer
-{
-    typedef typename _Alloc::void_pointer type;
-};
-
-template <class _Ptr, class _Alloc>
-struct __void_pointer<_Ptr, _Alloc, false>
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename pointer_traits<_Ptr>::template rebind<void> type;
-#else
-    typedef typename pointer_traits<_Ptr>::template rebind<void>::other type;
-#endif
-};
-
-template <class _Tp, class = void>
-struct __has_const_void_pointer : false_type {};
-
-template <class _Tp>
-struct __has_const_void_pointer<_Tp,
-            typename __void_t<typename _Tp::const_void_pointer>::type> : true_type {};
-
-template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
-struct __const_void_pointer
-{
-    typedef typename _Alloc::const_void_pointer type;
-};
-
-template <class _Ptr, class _Alloc>
-struct __const_void_pointer<_Ptr, _Alloc, false>
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename pointer_traits<_Ptr>::template rebind<const void> type;
-#else
-    typedef typename pointer_traits<_Ptr>::template rebind<const void>::other type;
-#endif
-};
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-_Tp*
-__to_raw_pointer(_Tp* __p) _NOEXCEPT
-{
-    return __p;
-}
-
-#if _LIBCPP_STD_VER <= 17
-template <class _Pointer>
-inline _LIBCPP_INLINE_VISIBILITY
-typename pointer_traits<_Pointer>::element_type*
-__to_raw_pointer(_Pointer __p) _NOEXCEPT
-{
-    return _VSTD::__to_raw_pointer(__p.operator->());
-}
-#else
-template <class _Pointer>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-__to_raw_pointer(const _Pointer& __p) _NOEXCEPT
--> decltype(pointer_traits<_Pointer>::to_address(__p))
-{
-    return pointer_traits<_Pointer>::to_address(__p);
-}
-
-template <class _Pointer, class... _None>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-__to_raw_pointer(const _Pointer& __p, _None...) _NOEXCEPT
-{
-    return _VSTD::__to_raw_pointer(__p.operator->());
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY constexpr
-_Tp*
-to_address(_Tp* __p) _NOEXCEPT
-{
-    static_assert(!is_function_v<_Tp>, "_Tp is a function type");
-    return __p;
-}
-
-template <class _Pointer>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-to_address(const _Pointer& __p) _NOEXCEPT
-{
-    return _VSTD::__to_raw_pointer(__p);
-}
-#endif
-
-template <class _Tp, class = void>
-struct __has_size_type : false_type {};
-
-template <class _Tp>
-struct __has_size_type<_Tp,
-               typename __void_t<typename _Tp::size_type>::type> : true_type {};
-
-template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
-struct __size_type
-{
-    typedef typename make_unsigned<_DiffType>::type type;
-};
-
-template <class _Alloc, class _DiffType>
-struct __size_type<_Alloc, _DiffType, true>
-{
-    typedef typename _Alloc::size_type type;
-};
-
-template <class _Tp, class = void>
-struct __has_propagate_on_container_copy_assignment : false_type {};
-
-template <class _Tp>
-struct __has_propagate_on_container_copy_assignment<_Tp,
-    typename __void_t<typename _Tp::propagate_on_container_copy_assignment>::type>
-        : true_type {};
-
-template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
-struct __propagate_on_container_copy_assignment
-{
-    typedef false_type type;
-};
-
-template <class _Alloc>
-struct __propagate_on_container_copy_assignment<_Alloc, true>
-{
-    typedef typename _Alloc::propagate_on_container_copy_assignment type;
-};
-
-template <class _Tp, class = void>
-struct __has_propagate_on_container_move_assignment : false_type {};
-
-template <class _Tp>
-struct __has_propagate_on_container_move_assignment<_Tp,
-           typename __void_t<typename _Tp::propagate_on_container_move_assignment>::type>
-               : true_type {};
-
-template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
-struct __propagate_on_container_move_assignment
-{
-    typedef false_type type;
-};
-
-template <class _Alloc>
-struct __propagate_on_container_move_assignment<_Alloc, true>
-{
-    typedef typename _Alloc::propagate_on_container_move_assignment type;
-};
-
-template <class _Tp, class = void>
-struct __has_propagate_on_container_swap : false_type {};
-
-template <class _Tp>
-struct __has_propagate_on_container_swap<_Tp,
-           typename __void_t<typename _Tp::propagate_on_container_swap>::type>
-               : true_type {};
-
-template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
-struct __propagate_on_container_swap
-{
-    typedef false_type type;
-};
-
-template <class _Alloc>
-struct __propagate_on_container_swap<_Alloc, true>
-{
-    typedef typename _Alloc::propagate_on_container_swap type;
-};
-
-template <class _Tp, class = void>
-struct __has_is_always_equal : false_type {};
-
-template <class _Tp>
-struct __has_is_always_equal<_Tp,
-           typename __void_t<typename _Tp::is_always_equal>::type>
-               : true_type {};
-
-template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
-struct __is_always_equal
-{
-    typedef typename _VSTD::is_empty<_Alloc>::type type;
-};
-
-template <class _Alloc>
-struct __is_always_equal<_Alloc, true>
-{
-    typedef typename _Alloc::is_always_equal type;
-};
-
-template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
-struct __has_rebind_other
-{
-private:
-    struct __two {char __lx; char __lxx;};
-    template <class _Xp> static __two __test(...);
-    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
-public:
-    static const bool value = sizeof(__test<_Tp>(0)) == 1;
-};
-
-template <class _Tp, class _Up>
-struct __has_rebind_other<_Tp, _Up, false>
-{
-    static const bool value = false;
-};
-
-template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
-struct __allocator_traits_rebind
-{
-    typedef typename _Tp::template rebind<_Up>::other type;
-};
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
-{
-    typedef typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
-};
-
-template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
-{
-    typedef _Alloc<_Up, _Args...> type;
-};
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-template <template <class> class _Alloc, class _Tp, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, true>
-{
-    typedef typename _Alloc<_Tp>::template rebind<_Up>::other type;
-};
-
-template <template <class> class _Alloc, class _Tp, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, false>
-{
-    typedef _Alloc<_Up> type;
-};
-
-template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, true>
-{
-    typedef typename _Alloc<_Tp, _A0>::template rebind<_Up>::other type;
-};
-
-template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, false>
-{
-    typedef _Alloc<_Up, _A0> type;
-};
-
-template <template <class, class, class> class _Alloc, class _Tp, class _A0,
-                                         class _A1, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, true>
-{
-    typedef typename _Alloc<_Tp, _A0, _A1>::template rebind<_Up>::other type;
-};
-
-template <template <class, class, class> class _Alloc, class _Tp, class _A0,
-                                         class _A1, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, false>
-{
-    typedef _Alloc<_Up, _A0, _A1> type;
-};
-
-template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
-                                                class _A1, class _A2, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, true>
-{
-    typedef typename _Alloc<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
-};
-
-template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
-                                                class _A1, class _A2, class _Up>
-struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, false>
-{
-    typedef _Alloc<_Up, _A0, _A1, _A2> type;
-};
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Alloc, class _SizeType, class _ConstVoidPtr>
-auto
-__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
-    -> decltype((void)__a.allocate(__sz, __p), true_type());
-
-template <class _Alloc, class _SizeType, class _ConstVoidPtr>
-auto
-__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
-    -> false_type;
-
-template <class _Alloc, class _SizeType, class _ConstVoidPtr>
-struct __has_allocate_hint
-    : integral_constant<bool,
-        is_same<
-            decltype(_VSTD::__has_allocate_hint_test(declval<_Alloc>(),
-                                          declval<_SizeType>(),
-                                          declval<_ConstVoidPtr>())),
-            true_type>::value>
-{
-};
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _Alloc, class _SizeType, class _ConstVoidPtr>
-struct __has_allocate_hint
-    : true_type
-{
-};
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#if !defined(_LIBCPP_CXX03_LANG)
-
-template <class _Alloc, class _Tp, class ..._Args>
-decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Tp*>(),
-                                           _VSTD::declval<_Args>()...),
-                                           true_type())
-__has_construct_test(_Alloc&& __a, _Tp* __p, _Args&& ...__args);
-
-template <class _Alloc, class _Pointer, class ..._Args>
-false_type
-__has_construct_test(const _Alloc& __a, _Pointer&& __p, _Args&& ...__args);
-
-template <class _Alloc, class _Pointer, class ..._Args>
-struct __has_construct
-    : integral_constant<bool,
-        is_same<
-            decltype(_VSTD::__has_construct_test(declval<_Alloc>(),
-                                          declval<_Pointer>(),
-                                          declval<_Args>()...)),
-            true_type>::value>
-{
-};
-
-template <class _Alloc, class _Pointer>
-auto
-__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
-    -> decltype(__a.destroy(__p), true_type());
-
-template <class _Alloc, class _Pointer>
-auto
-__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
-    -> false_type;
-
-template <class _Alloc, class _Pointer>
-struct __has_destroy
-    : integral_constant<bool,
-        is_same<
-            decltype(_VSTD::__has_destroy_test(declval<_Alloc>(),
-                                        declval<_Pointer>())),
-            true_type>::value>
-{
-};
-
-template <class _Alloc>
-auto
-__has_max_size_test(_Alloc&& __a)
-    -> decltype(__a.max_size(), true_type());
-
-template <class _Alloc>
-auto
-__has_max_size_test(const volatile _Alloc& __a)
-    -> false_type;
-
-template <class _Alloc>
-struct __has_max_size
-    : integral_constant<bool,
-        is_same<
-            decltype(_VSTD::__has_max_size_test(declval<_Alloc&>())),
-            true_type>::value>
-{
-};
-
-template <class _Alloc>
-auto
-__has_select_on_container_copy_construction_test(_Alloc&& __a)
-    -> decltype(__a.select_on_container_copy_construction(), true_type());
-
-template <class _Alloc>
-auto
-__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
-    -> false_type;
-
-template <class _Alloc>
-struct __has_select_on_container_copy_construction
-    : integral_constant<bool,
-        is_same<
-            decltype(_VSTD::__has_select_on_container_copy_construction_test(declval<_Alloc&>())),
-            true_type>::value>
-{
-};
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _Alloc, class _Pointer, class _Tp, class = void>
-struct __has_construct : std::false_type {};
-
-template <class _Alloc, class _Pointer, class _Tp>
-struct __has_construct<_Alloc, _Pointer, _Tp, typename __void_t<
-    decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Pointer>(), _VSTD::declval<_Tp>()))
->::type> : std::true_type {};
-
-template <class _Alloc, class _Pointer, class = void>
-struct __has_destroy : false_type {};
-
-template <class _Alloc, class _Pointer>
-struct __has_destroy<_Alloc, _Pointer, typename __void_t<
-    decltype(_VSTD::declval<_Alloc>().destroy(_VSTD::declval<_Pointer>()))
->::type> : std::true_type {};
-
-template <class _Alloc>
-struct __has_max_size
-    : true_type
-{
-};
-
-template <class _Alloc>
-struct __has_select_on_container_copy_construction
-    : false_type
-{
-};
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
-struct __alloc_traits_difference_type
-{
-    typedef typename pointer_traits<_Ptr>::difference_type type;
-};
-
-template <class _Alloc, class _Ptr>
-struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
-{
-    typedef typename _Alloc::difference_type type;
-};
-
-template <class _Tp>
-struct __is_default_allocator : false_type {};
-
-template <class _Tp>
-struct __is_default_allocator<_VSTD::allocator<_Tp> > : true_type {};
-
-template <class _Alloc>
-struct _LIBCPP_TEMPLATE_VIS allocator_traits
-{
-    typedef _Alloc                              allocator_type;
-    typedef typename allocator_type::value_type value_type;
-
-    typedef typename __pointer_type<value_type, allocator_type>::type pointer;
-    typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
-    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
-    typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;
-
-    typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
-    typedef typename __size_type<allocator_type, difference_type>::type size_type;
-
-    typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
-                     propagate_on_container_copy_assignment;
-    typedef typename __propagate_on_container_move_assignment<allocator_type>::type
-                     propagate_on_container_move_assignment;
-    typedef typename __propagate_on_container_swap<allocator_type>::type
-                     propagate_on_container_swap;
-    typedef typename __is_always_equal<allocator_type>::type
-                     is_always_equal;
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Tp> using rebind_alloc =
-                  typename __allocator_traits_rebind<allocator_type, _Tp>::type;
-    template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp>>;
-#else  // _LIBCPP_CXX03_LANG
-    template <class _Tp> struct rebind_alloc
-        {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
-    template <class _Tp> struct rebind_traits
-        {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    static pointer allocate(allocator_type& __a, size_type __n)
-        {return __a.allocate(__n);}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
-        {return __allocate(__a, __n, __hint,
-            __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
-        {__a.deallocate(__p, __n);}
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-    template <class _Tp, class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
-            {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
-                         __a, __p, _VSTD::forward<_Args>(__args)...);}
-#else  // _LIBCPP_HAS_NO_VARIADICS
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        static void construct(allocator_type&, _Tp* __p)
-            {
-                ::new ((void*)__p) _Tp();
-            }
-    template <class _Tp, class _A0>
-        _LIBCPP_INLINE_VISIBILITY
-        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0)
-            {
-                __construct(__has_construct<allocator_type, _Tp*, const _A0&>(),
-                            __a, __p, __a0);
-            }
-    template <class _Tp, class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
-                              const _A1& __a1)
-            {
-                ::new ((void*)__p) _Tp(__a0, __a1);
-            }
-    template <class _Tp, class _A0, class _A1, class _A2>
-        _LIBCPP_INLINE_VISIBILITY
-        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
-                              const _A1& __a1, const _A2& __a2)
-            {
-                ::new ((void*)__p) _Tp(__a0, __a1, __a2);
-            }
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        static void destroy(allocator_type& __a, _Tp* __p)
-            {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    static size_type max_size(const allocator_type& __a) _NOEXCEPT
-        {return __max_size(__has_max_size<const allocator_type>(), __a);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    static allocator_type
-        select_on_container_copy_construction(const allocator_type& __a)
-            {return __select_on_container_copy_construction(
-                __has_select_on_container_copy_construction<const allocator_type>(),
-                __a);}
-
-    template <class _Ptr>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        void
-        __construct_forward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
-        {
-            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
-                construct(__a, _VSTD::__to_raw_pointer(__begin2), _VSTD::move_if_noexcept(*__begin1));
-        }
-
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        typename enable_if
-        <
-            (__is_default_allocator<allocator_type>::value
-                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
-             is_trivially_move_constructible<_Tp>::value,
-            void
-        >::type
-        __construct_forward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
-        {
-            ptrdiff_t _Np = __end1 - __begin1;
-            if (_Np > 0)
-            {
-                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
-                __begin2 += _Np;
-            }
-        }
-
-    template <class _Iter, class _Ptr>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        void
-        __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
-        {
-            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
-                construct(__a, _VSTD::__to_raw_pointer(__begin2), *__begin1);
-        }
-
-    template <class _SourceTp, class _DestTp,
-              class _RawSourceTp = typename remove_const<_SourceTp>::type,
-              class _RawDestTp = typename remove_const<_DestTp>::type>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        typename enable_if
-        <
-            is_trivially_move_constructible<_DestTp>::value &&
-            is_same<_RawSourceTp, _RawDestTp>::value &&
-            (__is_default_allocator<allocator_type>::value ||
-             !__has_construct<allocator_type, _DestTp*, _SourceTp&>::value),
-            void
-        >::type
-        __construct_range_forward(allocator_type&, _SourceTp* __begin1, _SourceTp* __end1, _DestTp*& __begin2)
-        {
-            ptrdiff_t _Np = __end1 - __begin1;
-            if (_Np > 0)
-            {
-                _VSTD::memcpy(const_cast<_RawDestTp*>(__begin2), __begin1, _Np * sizeof(_DestTp));
-                __begin2 += _Np;
-            }
-        }
-
-    template <class _Ptr>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        void
-        __construct_backward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
-        {
-            while (__end1 != __begin1)
-            {
-                construct(__a, _VSTD::__to_raw_pointer(__end2-1), _VSTD::move_if_noexcept(*--__end1));
-                --__end2;
-            }
-        }
-
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        typename enable_if
-        <
-            (__is_default_allocator<allocator_type>::value
-                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
-             is_trivially_move_constructible<_Tp>::value,
-            void
-        >::type
-        __construct_backward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
-        {
-            ptrdiff_t _Np = __end1 - __begin1;
-            __end2 -= _Np;
-            if (_Np > 0)
-                _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
-        }
-
-private:
-
-    _LIBCPP_INLINE_VISIBILITY
-    static pointer __allocate(allocator_type& __a, size_type __n,
-        const_void_pointer __hint, true_type)
-        {return __a.allocate(__n, __hint);}
-    _LIBCPP_INLINE_VISIBILITY
-    static pointer __allocate(allocator_type& __a, size_type __n,
-        const_void_pointer, false_type)
-        {return __a.allocate(__n);}
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-    template <class _Tp, class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        static void __construct(true_type, allocator_type& __a, _Tp* __p, _Args&&... __args)
-            {__a.construct(__p, _VSTD::forward<_Args>(__args)...);}
-    template <class _Tp, class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        static void __construct(false_type, allocator_type&, _Tp* __p, _Args&&... __args)
-            {
-                ::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
-            }
-#else  // _LIBCPP_HAS_NO_VARIADICS
-    template <class _Tp, class _A0>
-        _LIBCPP_INLINE_VISIBILITY
-        static void __construct(true_type, allocator_type& __a, _Tp* __p,
-                                const _A0& __a0)
-            {__a.construct(__p, __a0);}
-    template <class _Tp, class _A0>
-        _LIBCPP_INLINE_VISIBILITY
-        static void __construct(false_type, allocator_type&, _Tp* __p,
-                                const _A0& __a0)
-            {
-                ::new ((void*)__p) _Tp(__a0);
-            }
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        static void __destroy(true_type, allocator_type& __a, _Tp* __p)
-            {__a.destroy(__p);}
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        static void __destroy(false_type, allocator_type&, _Tp* __p)
-            {
-                __p->~_Tp();
-            }
-
-    _LIBCPP_INLINE_VISIBILITY
-    static size_type __max_size(true_type, const allocator_type& __a) _NOEXCEPT
-            {return __a.max_size();}
-    _LIBCPP_INLINE_VISIBILITY
-    static size_type __max_size(false_type, const allocator_type&) _NOEXCEPT
-            {return numeric_limits<size_type>::max() / sizeof(value_type);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    static allocator_type
-        __select_on_container_copy_construction(true_type, const allocator_type& __a)
-            {return __a.select_on_container_copy_construction();}
-    _LIBCPP_INLINE_VISIBILITY
-    static allocator_type
-        __select_on_container_copy_construction(false_type, const allocator_type& __a)
-            {return __a;}
-};
-
-template <class _Traits, class _Tp>
-struct __rebind_alloc_helper
-{
-#ifndef _LIBCPP_CXX03_LANG
-    typedef typename _Traits::template rebind_alloc<_Tp>        type;
-#else
-    typedef typename _Traits::template rebind_alloc<_Tp>::other type;
-#endif
-};
-
-// allocator
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS allocator
-{
-public:
-    typedef size_t            size_type;
-    typedef ptrdiff_t         difference_type;
-    typedef _Tp*              pointer;
-    typedef const _Tp*        const_pointer;
-    typedef _Tp&              reference;
-    typedef const _Tp&        const_reference;
-    typedef _Tp               value_type;
-
-    typedef true_type propagate_on_container_move_assignment;
-    typedef true_type is_always_equal;
-
-    template <class _Up> struct rebind {typedef allocator<_Up> other;};
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-    allocator() _NOEXCEPT {}
-
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-    allocator(const allocator<_Up>&) _NOEXCEPT {}
-
-    _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
-        {return _VSTD::addressof(__x);}
-    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
-        {return _VSTD::addressof(__x);}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
-        {
-        if (__n > max_size())
-            __throw_length_error("allocator<T>::allocate(size_t n)"
-                                 " 'n' exceeds maximum supported size");
-        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
-        }
-    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
-        {_VSTD::__libcpp_deallocate((void*)__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
-    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
-        {return size_type(~0) / sizeof(_Tp);}
-#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-    template <class _Up, class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(_Up* __p, _Args&&... __args)
-        {
-            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
-        }
-#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p)
-        {
-            ::new((void*)__p) _Tp();
-        }
-# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
-
-    template <class _A0>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, _A0& __a0)
-        {
-            ::new((void*)__p) _Tp(__a0);
-        }
-    template <class _A0>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, const _A0& __a0)
-        {
-            ::new((void*)__p) _Tp(__a0);
-        }
-# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
-    template <class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, _A0& __a0, _A1& __a1)
-        {
-            ::new((void*)__p) _Tp(__a0, __a1);
-        }
-    template <class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, const _A0& __a0, _A1& __a1)
-        {
-            ::new((void*)__p) _Tp(__a0, __a1);
-        }
-    template <class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, _A0& __a0, const _A1& __a1)
-        {
-            ::new((void*)__p) _Tp(__a0, __a1);
-        }
-    template <class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, const _A0& __a0, const _A1& __a1)
-        {
-            ::new((void*)__p) _Tp(__a0, __a1);
-        }
-#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
-};
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
-{
-public:
-    typedef size_t            size_type;
-    typedef ptrdiff_t         difference_type;
-    typedef const _Tp*        pointer;
-    typedef const _Tp*        const_pointer;
-    typedef const _Tp&        reference;
-    typedef const _Tp&        const_reference;
-    typedef const _Tp         value_type;
-
-    typedef true_type propagate_on_container_move_assignment;
-    typedef true_type is_always_equal;
-
-    template <class _Up> struct rebind {typedef allocator<_Up> other;};
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-    allocator() _NOEXCEPT {}
-
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-    allocator(const allocator<_Up>&) _NOEXCEPT {}
-
-    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
-        {return _VSTD::addressof(__x);}
-    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
-    {
-        if (__n > max_size())
-            __throw_length_error("allocator<const T>::allocate(size_t n)"
-                                 " 'n' exceeds maximum supported size");
-        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
-    }
-    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
-        {_VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
-    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
-        {return size_type(~0) / sizeof(_Tp);}
-#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-    template <class _Up, class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(_Up* __p, _Args&&... __args)
-        {
-            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
-        }
-#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p)
-        {
-            ::new((void*) const_cast<_Tp *>(__p)) _Tp();
-        }
-# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
-
-    template <class _A0>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, _A0& __a0)
-        {
-            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
-        }
-    template <class _A0>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, const _A0& __a0)
-        {
-            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
-        }
-# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
-    template <class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, _A0& __a0, _A1& __a1)
-        {
-            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
-        }
-    template <class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, const _A0& __a0, _A1& __a1)
-        {
-            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
-        }
-    template <class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, _A0& __a0, const _A1& __a1)
-        {
-            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
-        }
-    template <class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        void
-        construct(pointer __p, const _A0& __a0, const _A1& __a1)
-        {
-            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
-        }
-#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
-};
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
-
-template <class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
-
-template <class _OutputIterator, class _Tp>
-class _LIBCPP_TEMPLATE_VIS raw_storage_iterator
-    : public iterator<output_iterator_tag,
-                      _Tp,                                         // purposefully not C++03
-                      ptrdiff_t,                                   // purposefully not C++03
-                      _Tp*,                                        // purposefully not C++03
-                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
-{
-private:
-    _OutputIterator __x_;
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
-    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
-    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
-        {::new(_VSTD::addressof(*__x_)) _Tp(__element); return *this;}
-#if _LIBCPP_STD_VER >= 14
-    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
-        {::new(_VSTD::addressof(*__x_)) _Tp(_VSTD::move(__element)); return *this;}
-#endif
-    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
-        {raw_storage_iterator __t(*this); ++__x_; return __t;}
-#if _LIBCPP_STD_VER >= 14
-    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
-#endif
-};
-
-template <class _Tp>
-_LIBCPP_NODISCARD_EXT _LIBCPP_NO_CFI
-pair<_Tp*, ptrdiff_t>
-get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
-{
-    pair<_Tp*, ptrdiff_t> __r(0, 0);
-    const ptrdiff_t __m = (~ptrdiff_t(0) ^
-                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
-                           / sizeof(_Tp);
-    if (__n > __m)
-        __n = __m;
-    while (__n > 0)
-    {
-#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
-    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
-        {
-            std::align_val_t __al =
-                std::align_val_t(std::alignment_of<_Tp>::value);
-            __r.first = static_cast<_Tp*>(::operator new(
-                __n * sizeof(_Tp), __al, nothrow));
-        } else {
-            __r.first = static_cast<_Tp*>(::operator new(
-                __n * sizeof(_Tp), nothrow));
-        }
-#else
-    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
-        {
-            // Since aligned operator new is unavailable, return an empty
-            // buffer rather than one with invalid alignment.
-            return __r;
-        }
-
-        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
-#endif
-
-        if (__r.first)
-        {
-            __r.second = __n;
-            break;
-        }
-        __n /= 2;
-    }
-    return __r;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void return_temporary_buffer(_Tp* __p) _NOEXCEPT
-{
-  _VSTD::__libcpp_deallocate_unsized((void*)__p, _LIBCPP_ALIGNOF(_Tp));
-}
-
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
-template <class _Tp>
-struct _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr_ref
-{
-    _Tp* __ptr_;
-};
-
-template<class _Tp>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr
-{
-private:
-    _Tp* __ptr_;
-public:
-    typedef _Tp element_type;
-
-    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) throw() : __ptr_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) throw() : __ptr_(__p.release()) {}
-    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) throw()
-        : __ptr_(__p.release()) {}
-    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) throw()
-        {reset(__p.release()); return *this;}
-    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) throw()
-        {reset(__p.release()); return *this;}
-    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) throw()
-        {reset(__p.__ptr_); return *this;}
-    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() throw() {delete __ptr_;}
-
-    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const throw()
-        {return *__ptr_;}
-    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const throw() {return __ptr_;}
-    _LIBCPP_INLINE_VISIBILITY _Tp* get() const throw() {return __ptr_;}
-    _LIBCPP_INLINE_VISIBILITY _Tp* release() throw()
-    {
-        _Tp* __t = __ptr_;
-        __ptr_ = 0;
-        return __t;
-    }
-    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) throw()
-    {
-        if (__ptr_ != __p)
-            delete __ptr_;
-        __ptr_ = __p;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) throw() : __ptr_(__p.__ptr_) {}
-    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() throw()
-        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
-    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() throw()
-        {return auto_ptr<_Up>(release());}
-};
-
-template <>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr<void>
-{
-public:
-    typedef void element_type;
-};
-#endif
-
-template <class _Tp, int _Idx,
-          bool _CanBeEmptyBase =
-              is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value>
-struct __compressed_pair_elem {
-  typedef _Tp _ParamT;
-  typedef _Tp& reference;
-  typedef const _Tp& const_reference;
-
-#ifndef _LIBCPP_CXX03_LANG
-  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() : __value_() {}
-
-  template <class _Up, class = typename enable_if<
-      !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
-  >::type>
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr explicit
-  __compressed_pair_elem(_Up&& __u)
-      : __value_(_VSTD::forward<_Up>(__u))
-    {
-    }
-
-  template <class... _Args, size_t... _Indexes>
-  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
-                         __tuple_indices<_Indexes...>)
-      : __value_(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
-#else
-  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_() {}
-  _LIBCPP_INLINE_VISIBILITY
-  __compressed_pair_elem(_ParamT __p) : __value_(std::forward<_ParamT>(__p)) {}
-#endif
-
-  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return __value_; }
-  _LIBCPP_INLINE_VISIBILITY
-  const_reference __get() const _NOEXCEPT { return __value_; }
-
-private:
-  _Tp __value_;
-};
-
-template <class _Tp, int _Idx>
-struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp {
-  typedef _Tp _ParamT;
-  typedef _Tp& reference;
-  typedef const _Tp& const_reference;
-  typedef _Tp __value_type;
-
-#ifndef _LIBCPP_CXX03_LANG
-  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() = default;
-
-  template <class _Up, class = typename enable_if<
-        !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
-  >::type>
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr explicit
-  __compressed_pair_elem(_Up&& __u)
-      : __value_type(_VSTD::forward<_Up>(__u))
-  {}
-
-  template <class... _Args, size_t... _Indexes>
-  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
-                         __tuple_indices<_Indexes...>)
-      : __value_type(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
-#else
-  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_type() {}
-  _LIBCPP_INLINE_VISIBILITY
-  __compressed_pair_elem(_ParamT __p)
-      : __value_type(std::forward<_ParamT>(__p)) {}
-#endif
-
-  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return *this; }
-  _LIBCPP_INLINE_VISIBILITY
-  const_reference __get() const _NOEXCEPT { return *this; }
-};
-
-// Tag used to construct the second element of the compressed pair.
-struct __second_tag {};
-
-template <class _T1, class _T2>
-class __compressed_pair : private __compressed_pair_elem<_T1, 0>,
-                          private __compressed_pair_elem<_T2, 1> {
-  typedef __compressed_pair_elem<_T1, 0> _Base1;
-  typedef __compressed_pair_elem<_T2, 1> _Base2;
-
-  // NOTE: This static assert should never fire because __compressed_pair
-  // is *almost never* used in a scenario where it's possible for T1 == T2.
-  // (The exception is std::function where it is possible that the function
-  //  object and the allocator have the same type).
-  static_assert((!is_same<_T1, _T2>::value),
-    "__compressed_pair cannot be instantated when T1 and T2 are the same type; "
-    "The current implementation is NOT ABI-compatible with the previous "
-    "implementation for this configuration");
-
-public:
-#ifndef _LIBCPP_CXX03_LANG
-  template <bool _Dummy = true,
-      class = typename enable_if<
-          __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
-          __dependent_type<is_default_constructible<_T2>, _Dummy>::value
-      >::type
-  >
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr __compressed_pair() {}
-
-  template <class _Tp, typename enable_if<!is_same<typename decay<_Tp>::type,
-                                                   __compressed_pair>::value,
-                                          bool>::type = true>
-  _LIBCPP_INLINE_VISIBILITY constexpr explicit
-  __compressed_pair(_Tp&& __t)
-      : _Base1(std::forward<_Tp>(__t)), _Base2() {}
-
-  template <class _Tp>
-  _LIBCPP_INLINE_VISIBILITY constexpr
-  __compressed_pair(__second_tag, _Tp&& __t)
-      : _Base1(), _Base2(std::forward<_Tp>(__t)) {}
-
-  template <class _U1, class _U2>
-  _LIBCPP_INLINE_VISIBILITY constexpr
-  __compressed_pair(_U1&& __t1, _U2&& __t2)
-      : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {}
-
-  template <class... _Args1, class... _Args2>
-  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
-  __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
-                    tuple<_Args2...> __second_args)
-      : _Base1(__pc, _VSTD::move(__first_args),
-               typename __make_tuple_indices<sizeof...(_Args1)>::type()),
-        _Base2(__pc, _VSTD::move(__second_args),
-               typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}
-
-#else
-  _LIBCPP_INLINE_VISIBILITY
-  __compressed_pair() {}
-
-  _LIBCPP_INLINE_VISIBILITY explicit
-  __compressed_pair(_T1 __t1) : _Base1(_VSTD::forward<_T1>(__t1)) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  __compressed_pair(__second_tag, _T2 __t2)
-      : _Base1(), _Base2(_VSTD::forward<_T2>(__t2)) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  __compressed_pair(_T1 __t1, _T2 __t2)
-      : _Base1(_VSTD::forward<_T1>(__t1)), _Base2(_VSTD::forward<_T2>(__t2)) {}
-#endif
-
-  _LIBCPP_INLINE_VISIBILITY
-  typename _Base1::reference first() _NOEXCEPT {
-    return static_cast<_Base1&>(*this).__get();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  typename _Base1::const_reference first() const _NOEXCEPT {
-    return static_cast<_Base1 const&>(*this).__get();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  typename _Base2::reference second() _NOEXCEPT {
-    return static_cast<_Base2&>(*this).__get();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  typename _Base2::const_reference second() const _NOEXCEPT {
-    return static_cast<_Base2 const&>(*this).__get();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void swap(__compressed_pair& __x)
-    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
-               __is_nothrow_swappable<_T2>::value)
-  {
-    using std::swap;
-    swap(first(), __x.first());
-    swap(second(), __x.second());
-  }
-};
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
-    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
-               __is_nothrow_swappable<_T2>::value) {
-  __x.swap(__y);
-}
-
-// default_delete
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS default_delete {
-    static_assert(!is_function<_Tp>::value,
-                  "default_delete cannot be instantiated for function types");
-#ifndef _LIBCPP_CXX03_LANG
-  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() noexcept = default;
-#else
-  _LIBCPP_INLINE_VISIBILITY default_delete() {}
-#endif
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  default_delete(const default_delete<_Up>&,
-                 typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* =
-                     0) _NOEXCEPT {}
-
-  _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __ptr) const _NOEXCEPT {
-    static_assert(sizeof(_Tp) > 0,
-                  "default_delete can not delete incomplete type");
-    static_assert(!is_void<_Tp>::value,
-                  "default_delete can not delete incomplete type");
-    delete __ptr;
-  }
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS default_delete<_Tp[]> {
-private:
-  template <class _Up>
-  struct _EnableIfConvertible
-      : enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value> {};
-
-public:
-#ifndef _LIBCPP_CXX03_LANG
-  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() noexcept = default;
-#else
-  _LIBCPP_INLINE_VISIBILITY default_delete() {}
-#endif
-
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  default_delete(const default_delete<_Up[]>&,
-                 typename _EnableIfConvertible<_Up>::type* = 0) _NOEXCEPT {}
-
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  typename _EnableIfConvertible<_Up>::type
-  operator()(_Up* __ptr) const _NOEXCEPT {
-    static_assert(sizeof(_Tp) > 0,
-                  "default_delete can not delete incomplete type");
-    static_assert(!is_void<_Tp>::value,
-                  "default_delete can not delete void type");
-    delete[] __ptr;
-  }
-};
-
-
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Deleter>
-struct __unique_ptr_deleter_sfinae {
-  static_assert(!is_reference<_Deleter>::value, "incorrect specialization");
-  typedef const _Deleter& __lval_ref_type;
-  typedef _Deleter&& __good_rval_ref_type;
-  typedef true_type __enable_rval_overload;
-};
-
-template <class _Deleter>
-struct __unique_ptr_deleter_sfinae<_Deleter const&> {
-  typedef const _Deleter& __lval_ref_type;
-  typedef const _Deleter&& __bad_rval_ref_type;
-  typedef false_type __enable_rval_overload;
-};
-
-template <class _Deleter>
-struct __unique_ptr_deleter_sfinae<_Deleter&> {
-  typedef _Deleter& __lval_ref_type;
-  typedef _Deleter&& __bad_rval_ref_type;
-  typedef false_type __enable_rval_overload;
-};
-#endif // !defined(_LIBCPP_CXX03_LANG)
-
-template <class _Tp, class _Dp = default_delete<_Tp> >
-class _LIBCPP_TEMPLATE_VIS unique_ptr {
-public:
-  typedef _Tp element_type;
-  typedef _Dp deleter_type;
-  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
-
-  static_assert(!is_rvalue_reference<deleter_type>::value,
-                "the specified deleter type cannot be an rvalue reference");
-
-private:
-  __compressed_pair<pointer, deleter_type> __ptr_;
-
-  struct __nat { int __for_bool_; };
-
-#ifndef _LIBCPP_CXX03_LANG
-  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
-
-  template <bool _Dummy>
-  using _LValRefType =
-      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
-
-  template <bool _Dummy>
-  using _GoodRValRefType =
-      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
-
-  template <bool _Dummy>
-  using _BadRValRefType =
-      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
-
-  template <bool _Dummy, class _Deleter = typename __dependent_type<
-                             __identity<deleter_type>, _Dummy>::type>
-  using _EnableIfDeleterDefaultConstructible =
-      typename enable_if<is_default_constructible<_Deleter>::value &&
-                         !is_pointer<_Deleter>::value>::type;
-
-  template <class _ArgType>
-  using _EnableIfDeleterConstructible =
-      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
-
-  template <class _UPtr, class _Up>
-  using _EnableIfMoveConvertible = typename enable_if<
-      is_convertible<typename _UPtr::pointer, pointer>::value &&
-      !is_array<_Up>::value
-  >::type;
-
-  template <class _UDel>
-  using _EnableIfDeleterConvertible = typename enable_if<
-      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
-      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
-    >::type;
-
-  template <class _UDel>
-  using _EnableIfDeleterAssignable = typename enable_if<
-      is_assignable<_Dp&, _UDel&&>::value
-    >::type;
-
-public:
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr unique_ptr() noexcept : __ptr_(pointer()) {}
-
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr unique_ptr(nullptr_t) noexcept : __ptr_(pointer()) {}
-
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
-  _LIBCPP_INLINE_VISIBILITY
-  explicit unique_ptr(pointer __p) noexcept : __ptr_(__p) {}
-
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>>
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(pointer __p, _LValRefType<_Dummy> __d) noexcept
-      : __ptr_(__p, __d) {}
-
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>>
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(pointer __p, _GoodRValRefType<_Dummy> __d) noexcept
-      : __ptr_(__p, _VSTD::move(__d)) {
-    static_assert(!is_reference<deleter_type>::value,
-                  "rvalue deleter bound to reference");
-  }
-
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy>>>
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(pointer __p, _BadRValRefType<_Dummy> __d) = delete;
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(unique_ptr&& __u) noexcept
-      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
-  }
-
-  template <class _Up, class _Ep,
-      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
-      class = _EnableIfDeleterConvertible<_Ep>
-  >
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
-      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
-
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(auto_ptr<_Up>&& __p,
-             typename enable_if<is_convertible<_Up*, _Tp*>::value &&
-                                    is_same<_Dp, default_delete<_Tp>>::value,
-                                __nat>::type = __nat()) _NOEXCEPT
-      : __ptr_(__p.release()) {}
-#endif
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
-    reset(__u.release());
-    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
-    return *this;
-  }
-
-  template <class _Up, class _Ep,
-      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
-      class = _EnableIfDeleterAssignable<_Ep>
-  >
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr& operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
-    reset(__u.release());
-    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
-    return *this;
-  }
-
-#else  // _LIBCPP_CXX03_LANG
-private:
-  unique_ptr(unique_ptr&);
-  template <class _Up, class _Ep> unique_ptr(unique_ptr<_Up, _Ep>&);
-
-  unique_ptr& operator=(unique_ptr&);
-  template <class _Up, class _Ep> unique_ptr& operator=(unique_ptr<_Up, _Ep>&);
-
-public:
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr() : __ptr_(pointer())
-  {
-    static_assert(!is_pointer<deleter_type>::value,
-                  "unique_ptr constructed with null function pointer deleter");
-    static_assert(is_default_constructible<deleter_type>::value,
-                  "unique_ptr::deleter_type is not default constructible");
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(nullptr_t) : __ptr_(pointer())
-  {
-    static_assert(!is_pointer<deleter_type>::value,
-                  "unique_ptr constructed with null function pointer deleter");
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  explicit unique_ptr(pointer __p)
-      : __ptr_(_VSTD::move(__p)) {
-    static_assert(!is_pointer<deleter_type>::value,
-                  "unique_ptr constructed with null function pointer deleter");
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  operator __rv<unique_ptr>() {
-    return __rv<unique_ptr>(*this);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(__rv<unique_ptr> __u)
-      : __ptr_(__u->release(),
-               _VSTD::forward<deleter_type>(__u->get_deleter())) {}
-
-  template <class _Up, class _Ep>
-  _LIBCPP_INLINE_VISIBILITY
-  typename enable_if<
-      !is_array<_Up>::value &&
-          is_convertible<typename unique_ptr<_Up, _Ep>::pointer,
-                         pointer>::value &&
-          is_assignable<deleter_type&, _Ep&>::value,
-      unique_ptr&>::type
-  operator=(unique_ptr<_Up, _Ep> __u) {
-    reset(__u.release());
-    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(pointer __p, deleter_type __d)
-      : __ptr_(_VSTD::move(__p), _VSTD::move(__d)) {}
-#endif // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
-  template <class _Up>
-  _LIBCPP_INLINE_VISIBILITY
-      typename enable_if<is_convertible<_Up*, _Tp*>::value &&
-                             is_same<_Dp, default_delete<_Tp> >::value,
-                         unique_ptr&>::type
-      operator=(auto_ptr<_Up> __p) {
-    reset(__p.release());
-    return *this;
-  }
-#endif
-
-  _LIBCPP_INLINE_VISIBILITY
-  ~unique_ptr() { reset(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
-    reset();
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  typename add_lvalue_reference<_Tp>::type
-  operator*() const {
-    return *__ptr_.first();
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  pointer operator->() const _NOEXCEPT {
-    return __ptr_.first();
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  pointer get() const _NOEXCEPT {
-    return __ptr_.first();
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  deleter_type& get_deleter() _NOEXCEPT {
-    return __ptr_.second();
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  const deleter_type& get_deleter() const _NOEXCEPT {
-    return __ptr_.second();
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
-    return __ptr_.first() != nullptr;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  pointer release() _NOEXCEPT {
-    pointer __t = __ptr_.first();
-    __ptr_.first() = pointer();
-    return __t;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void reset(pointer __p = pointer()) _NOEXCEPT {
-    pointer __tmp = __ptr_.first();
-    __ptr_.first() = __p;
-    if (__tmp)
-      __ptr_.second()(__tmp);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void swap(unique_ptr& __u) _NOEXCEPT {
-    __ptr_.swap(__u.__ptr_);
-  }
-};
-
-
-template <class _Tp, class _Dp>
-class _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
-public:
-  typedef _Tp element_type;
-  typedef _Dp deleter_type;
-  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
-
-private:
-  __compressed_pair<pointer, deleter_type> __ptr_;
-
-  template <class _From>
-  struct _CheckArrayPointerConversion : is_same<_From, pointer> {};
-
-  template <class _FromElem>
-  struct _CheckArrayPointerConversion<_FromElem*>
-      : integral_constant<bool,
-          is_same<_FromElem*, pointer>::value ||
-            (is_same<pointer, element_type*>::value &&
-             is_convertible<_FromElem(*)[], element_type(*)[]>::value)
-      >
-  {};
-
-#ifndef _LIBCPP_CXX03_LANG
-  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
-
-  template <bool _Dummy>
-  using _LValRefType =
-      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
-
-  template <bool _Dummy>
-  using _GoodRValRefType =
-      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
-
-  template <bool _Dummy>
-  using _BadRValRefType =
-      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
-
-  template <bool _Dummy, class _Deleter = typename __dependent_type<
-                             __identity<deleter_type>, _Dummy>::type>
-  using _EnableIfDeleterDefaultConstructible =
-      typename enable_if<is_default_constructible<_Deleter>::value &&
-                         !is_pointer<_Deleter>::value>::type;
-
-  template <class _ArgType>
-  using _EnableIfDeleterConstructible =
-      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
-
-  template <class _Pp>
-  using _EnableIfPointerConvertible = typename enable_if<
-      _CheckArrayPointerConversion<_Pp>::value
-  >::type;
-
-  template <class _UPtr, class _Up,
-        class _ElemT = typename _UPtr::element_type>
-  using _EnableIfMoveConvertible = typename enable_if<
-      is_array<_Up>::value &&
-      is_same<pointer, element_type*>::value &&
-      is_same<typename _UPtr::pointer, _ElemT*>::value &&
-      is_convertible<_ElemT(*)[], element_type(*)[]>::value
-    >::type;
-
-  template <class _UDel>
-  using _EnableIfDeleterConvertible = typename enable_if<
-      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
-      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
-    >::type;
-
-  template <class _UDel>
-  using _EnableIfDeleterAssignable = typename enable_if<
-      is_assignable<_Dp&, _UDel&&>::value
-    >::type;
-
-public:
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr unique_ptr() noexcept : __ptr_(pointer()) {}
-
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
-  _LIBCPP_INLINE_VISIBILITY
-  constexpr unique_ptr(nullptr_t) noexcept : __ptr_(pointer()) {}
-
-  template <class _Pp, bool _Dummy = true,
-            class = _EnableIfDeleterDefaultConstructible<_Dummy>,
-            class = _EnableIfPointerConvertible<_Pp>>
-  _LIBCPP_INLINE_VISIBILITY
-  explicit unique_ptr(_Pp __p) noexcept
-      : __ptr_(__p) {}
-
-  template <class _Pp, bool _Dummy = true,
-            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>,
-            class = _EnableIfPointerConvertible<_Pp>>
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(_Pp __p, _LValRefType<_Dummy> __d) noexcept
-      : __ptr_(__p, __d) {}
-
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>>
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(nullptr_t, _LValRefType<_Dummy> __d) noexcept
-      : __ptr_(nullptr, __d) {}
-
-  template <class _Pp, bool _Dummy = true,
-            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>,
-            class = _EnableIfPointerConvertible<_Pp>>
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(_Pp __p, _GoodRValRefType<_Dummy> __d) noexcept
-      : __ptr_(__p, _VSTD::move(__d)) {
-    static_assert(!is_reference<deleter_type>::value,
-                  "rvalue deleter bound to reference");
-  }
-
-  template <bool _Dummy = true,
-            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>>
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(nullptr_t, _GoodRValRefType<_Dummy> __d) noexcept
-      : __ptr_(nullptr, _VSTD::move(__d)) {
-    static_assert(!is_reference<deleter_type>::value,
-                  "rvalue deleter bound to reference");
-  }
-
-  template <class _Pp, bool _Dummy = true,
-            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy>>,
-            class = _EnableIfPointerConvertible<_Pp>>
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(_Pp __p, _BadRValRefType<_Dummy> __d) = delete;
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(unique_ptr&& __u) noexcept
-      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr& operator=(unique_ptr&& __u) noexcept {
-    reset(__u.release());
-    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
-    return *this;
-  }
-
-  template <class _Up, class _Ep,
-      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
-      class = _EnableIfDeleterConvertible<_Ep>
-  >
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
-      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {
-  }
-
-  template <class _Up, class _Ep,
-      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
-      class = _EnableIfDeleterAssignable<_Ep>
-  >
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr&
-  operator=(unique_ptr<_Up, _Ep>&& __u) noexcept {
-    reset(__u.release());
-    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
-    return *this;
-  }
-
-#else // _LIBCPP_CXX03_LANG
-private:
-  template <class _Up> explicit unique_ptr(_Up);
-
-  unique_ptr(unique_ptr&);
-  template <class _Up> unique_ptr(unique_ptr<_Up>&);
-
-  unique_ptr& operator=(unique_ptr&);
-  template <class _Up> unique_ptr& operator=(unique_ptr<_Up>&);
-
-  template <class _Up>
-  unique_ptr(_Up __u,
-             typename conditional<
-                 is_reference<deleter_type>::value, deleter_type,
-                 typename add_lvalue_reference<const deleter_type>::type>::type,
-             typename enable_if<is_convertible<_Up, pointer>::value,
-                                __nat>::type = __nat());
-public:
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr() : __ptr_(pointer()) {
-    static_assert(!is_pointer<deleter_type>::value,
-                  "unique_ptr constructed with null function pointer deleter");
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(nullptr_t) : __ptr_(pointer()) {
-    static_assert(!is_pointer<deleter_type>::value,
-                  "unique_ptr constructed with null function pointer deleter");
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  explicit unique_ptr(pointer __p) : __ptr_(__p) {
-    static_assert(!is_pointer<deleter_type>::value,
-                  "unique_ptr constructed with null function pointer deleter");
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(pointer __p, deleter_type __d)
-      : __ptr_(__p, _VSTD::forward<deleter_type>(__d)) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(nullptr_t, deleter_type __d)
-      : __ptr_(pointer(), _VSTD::forward<deleter_type>(__d)) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  operator __rv<unique_ptr>() {
-    return __rv<unique_ptr>(*this);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr(__rv<unique_ptr> __u)
-      : __ptr_(__u->release(),
-               _VSTD::forward<deleter_type>(__u->get_deleter())) {}
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr& operator=(__rv<unique_ptr> __u) {
-    reset(__u->release());
-    __ptr_.second() = _VSTD::forward<deleter_type>(__u->get_deleter());
-    return *this;
-  }
-
-#endif // _LIBCPP_CXX03_LANG
-
-public:
-  _LIBCPP_INLINE_VISIBILITY
-  ~unique_ptr() { reset(); }
-
-  _LIBCPP_INLINE_VISIBILITY
-  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
-    reset();
-    return *this;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  typename add_lvalue_reference<_Tp>::type
-  operator[](size_t __i) const {
-    return __ptr_.first()[__i];
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  pointer get() const _NOEXCEPT {
-    return __ptr_.first();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  deleter_type& get_deleter() _NOEXCEPT {
-    return __ptr_.second();
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  const deleter_type& get_deleter() const _NOEXCEPT {
-    return __ptr_.second();
-  }
-  _LIBCPP_INLINE_VISIBILITY
-  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
-    return __ptr_.first() != nullptr;
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  pointer release() _NOEXCEPT {
-    pointer __t = __ptr_.first();
-    __ptr_.first() = pointer();
-    return __t;
-  }
-
-  template <class _Pp>
-  _LIBCPP_INLINE_VISIBILITY
-  typename enable_if<
-      _CheckArrayPointerConversion<_Pp>::value
-  >::type
-  reset(_Pp __p) _NOEXCEPT {
-    pointer __tmp = __ptr_.first();
-    __ptr_.first() = __p;
-    if (__tmp)
-      __ptr_.second()(__tmp);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void reset(nullptr_t = nullptr) _NOEXCEPT {
-    pointer __tmp = __ptr_.first();
-    __ptr_.first() = nullptr;
-    if (__tmp)
-      __ptr_.second()(__tmp);
-  }
-
-  _LIBCPP_INLINE_VISIBILITY
-  void swap(unique_ptr& __u) _NOEXCEPT {
-    __ptr_.swap(__u.__ptr_);
-  }
-
-};
-
-template <class _Tp, class _Dp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if<
-    __is_swappable<_Dp>::value,
-    void
->::type
-swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
-
-template <class _T1, class _D1, class _T2, class _D2>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
-
-template <class _T1, class _D1, class _T2, class _D2>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
-
-template <class _T1, class _D1, class _T2, class _D2>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
-{
-    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
-    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
-    typedef typename common_type<_P1, _P2>::type _Vp;
-    return less<_Vp>()(__x.get(), __y.get());
-}
-
-template <class _T1, class _D1, class _T2, class _D2>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
-
-template <class _T1, class _D1, class _T2, class _D2>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
-
-template <class _T1, class _D1, class _T2, class _D2>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
-{
-    return !__x;
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
-{
-    return !__x;
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
-{
-    return static_cast<bool>(__x);
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
-{
-    return static_cast<bool>(__x);
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
-{
-    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
-    return less<_P1>()(__x.get(), nullptr);
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
-{
-    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
-    return less<_P1>()(nullptr, __x.get());
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
-{
-    return nullptr < __x;
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
-{
-    return __x < nullptr;
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
-{
-    return !(nullptr < __x);
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
-{
-    return !(__x < nullptr);
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
-{
-    return !(__x < nullptr);
-}
-
-template <class _T1, class _D1>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
-{
-    return !(nullptr < __x);
-}
-
-#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp, class _Dp>
-inline _LIBCPP_INLINE_VISIBILITY
-unique_ptr<_Tp, _Dp>
-move(unique_ptr<_Tp, _Dp>& __t)
-{
-    return unique_ptr<_Tp, _Dp>(__rv<unique_ptr<_Tp, _Dp> >(__t));
-}
-
-#endif
-
-#if _LIBCPP_STD_VER > 11
-
-template<class _Tp>
-struct __unique_if
-{
-    typedef unique_ptr<_Tp> __unique_single;
-};
-
-template<class _Tp>
-struct __unique_if<_Tp[]>
-{
-    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
-};
-
-template<class _Tp, size_t _Np>
-struct __unique_if<_Tp[_Np]>
-{
-    typedef void __unique_array_known_bound;
-};
-
-template<class _Tp, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __unique_if<_Tp>::__unique_single
-make_unique(_Args&&... __args)
-{
-    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename __unique_if<_Tp>::__unique_array_unknown_bound
-make_unique(size_t __n)
-{
-    typedef typename remove_extent<_Tp>::type _Up;
-    return unique_ptr<_Tp>(new _Up[__n]());
-}
-
-template<class _Tp, class... _Args>
-    typename __unique_if<_Tp>::__unique_array_known_bound
-    make_unique(_Args&&...) = delete;
-
-#endif  // _LIBCPP_STD_VER > 11
-
-template <class _Tp, class _Dp>
-#ifdef _LIBCPP_CXX03_LANG
-struct _LIBCPP_TEMPLATE_VIS hash<unique_ptr<_Tp, _Dp> >
-#else
-struct _LIBCPP_TEMPLATE_VIS hash<__enable_hash_helper<
-    unique_ptr<_Tp, _Dp>, typename unique_ptr<_Tp, _Dp>::pointer>>
-#endif
-{
-    typedef unique_ptr<_Tp, _Dp> argument_type;
-    typedef size_t               result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator()(const argument_type& __ptr) const
-    {
-        typedef typename argument_type::pointer pointer;
-        return hash<pointer>()(__ptr.get());
-    }
-};
-
-struct __destruct_n
-{
-private:
-    size_t __size_;
-
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
-        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
-
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
-        {++__size_;}
-    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
-        {__size_ = __s;}
-    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
-        {}
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
-        : __size_(__s) {}
-
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
-        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
-
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
-        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
-
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
-        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
-};
-
-template <class _Alloc>
-class __allocator_destructor
-{
-    typedef allocator_traits<_Alloc> __alloc_traits;
-public:
-    typedef typename __alloc_traits::pointer pointer;
-    typedef typename __alloc_traits::size_type size_type;
-private:
-    _Alloc& __alloc_;
-    size_type __s_;
-public:
-    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
-             _NOEXCEPT
-        : __alloc_(__a), __s_(__s) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()(pointer __p) _NOEXCEPT
-        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
-};
-
-template <class _InputIterator, class _ForwardIterator>
-_ForwardIterator
-uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    _ForwardIterator __s = __r;
-    try
-    {
-#endif
-        for (; __f != __l; ++__f, (void) ++__r)
-            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        for (; __s != __r; ++__s)
-            __s->~value_type();
-        throw;
-    }
-#endif
-    return __r;
-}
-
-template <class _InputIterator, class _Size, class _ForwardIterator>
-_ForwardIterator
-uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    _ForwardIterator __s = __r;
-    try
-    {
-#endif
-        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
-            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        for (; __s != __r; ++__s)
-            __s->~value_type();
-        throw;
-    }
-#endif
-    return __r;
-}
-
-template <class _ForwardIterator, class _Tp>
-void
-uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    _ForwardIterator __s = __f;
-    try
-    {
-#endif
-        for (; __f != __l; ++__f)
-            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        for (; __s != __f; ++__s)
-            __s->~value_type();
-        throw;
-    }
-#endif
-}
-
-template <class _ForwardIterator, class _Size, class _Tp>
-_ForwardIterator
-uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
-{
-    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    _ForwardIterator __s = __f;
-    try
-    {
-#endif
-        for (; __n > 0; ++__f, (void) --__n)
-            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        for (; __s != __f; ++__s)
-            __s->~value_type();
-        throw;
-    }
-#endif
-    return __f;
-}
-
-#if _LIBCPP_STD_VER > 14
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void destroy_at(_Tp* __loc) {
-    _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
-    __loc->~_Tp();
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void destroy(_ForwardIterator __first, _ForwardIterator __last) {
-    for (; __first != __last; ++__first)
-        _VSTD::destroy_at(_VSTD::addressof(*__first));
-}
-
-template <class _ForwardIterator, class _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
-    for (; __n > 0; (void)++__first, --__n)
-        _VSTD::destroy_at(_VSTD::addressof(*__first));
-    return __first;
-}
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
-    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
-    auto __idx = __first;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try {
-#endif
-    for (; __idx != __last; ++__idx)
-        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    } catch (...) {
-        _VSTD::destroy(__first, __idx);
-        throw;
-    }
-#endif
-}
-
-template <class _ForwardIterator, class _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
-    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
-    auto __idx = __first;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try {
-#endif
-    for (; __n > 0; (void)++__idx, --__n)
-        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
-    return __idx;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    } catch (...) {
-        _VSTD::destroy(__first, __idx);
-        throw;
-    }
-#endif
-}
-
-
-template <class _ForwardIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
-    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
-    auto __idx = __first;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try {
-#endif
-    for (; __idx != __last; ++__idx)
-        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    } catch (...) {
-        _VSTD::destroy(__first, __idx);
-        throw;
-    }
-#endif
-}
-
-template <class _ForwardIterator, class _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
-    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
-    auto __idx = __first;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try {
-#endif
-    for (; __n > 0; (void)++__idx, --__n)
-        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
-    return __idx;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    } catch (...) {
-        _VSTD::destroy(__first, __idx);
-        throw;
-    }
-#endif
-}
-
-
-template <class _InputIt, class _ForwardIt>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIt uninitialized_move(_InputIt __first, _InputIt __last, _ForwardIt __first_res) {
-    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
-    auto __idx = __first_res;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try {
-#endif
-    for (; __first != __last; (void)++__idx, ++__first)
-        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
-    return __idx;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    } catch (...) {
-        _VSTD::destroy(__first_res, __idx);
-        throw;
-    }
-#endif
-}
-
-template <class _InputIt, class _Size, class _ForwardIt>
-inline _LIBCPP_INLINE_VISIBILITY
-pair<_InputIt, _ForwardIt>
-uninitialized_move_n(_InputIt __first, _Size __n, _ForwardIt __first_res) {
-    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
-    auto __idx = __first_res;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try {
-#endif
-    for (; __n > 0; ++__idx, (void)++__first, --__n)
-        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
-    return {__first, __idx};
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    } catch (...) {
-        _VSTD::destroy(__first_res, __idx);
-        throw;
-    }
-#endif
-}
-
-
-#endif // _LIBCPP_STD_VER > 14
-
-// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
-// should be sufficient for thread safety.
-// See https://bugs.llvm.org/show_bug.cgi?id=22803
-#if defined(__clang__) && __has_builtin(__atomic_add_fetch)          \
-                       && defined(__ATOMIC_RELAXED)                  \
-                       && defined(__ATOMIC_ACQ_REL)
-#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
-#elif !defined(__clang__) && defined(_GNUC_VER) && _GNUC_VER >= 407
-#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
-#endif
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _Tp
-__libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT
-{
-#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
-    return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
-#else
-    return __t += 1;
-#endif
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _Tp
-__libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT
-{
-#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
-    return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
-#else
-    return __t -= 1;
-#endif
-}
-
-class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
-    : public std::exception
-{
-public:
-    virtual ~bad_weak_ptr() _NOEXCEPT;
-    virtual const char* what() const  _NOEXCEPT;
-};
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_bad_weak_ptr()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw bad_weak_ptr();
-#else
-    _VSTD::abort();
-#endif
-}
-
-template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr;
-
-class _LIBCPP_TYPE_VIS __shared_count
-{
-    __shared_count(const __shared_count&);
-    __shared_count& operator=(const __shared_count&);
-
-protected:
-    long __shared_owners_;
-    virtual ~__shared_count();
-private:
-    virtual void __on_zero_shared() _NOEXCEPT = 0;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __shared_count(long __refs = 0) _NOEXCEPT
-        : __shared_owners_(__refs) {}
-
-#if defined(_LIBCPP_BUILDING_LIBRARY) && \
-    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
-    void __add_shared() _NOEXCEPT;
-    bool __release_shared() _NOEXCEPT;
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_shared() _NOEXCEPT {
-      __libcpp_atomic_refcount_increment(__shared_owners_);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    bool __release_shared() _NOEXCEPT {
-      if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
-        __on_zero_shared();
-        return true;
-      }
-      return false;
-    }
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    long use_count() const _NOEXCEPT {
-        return __libcpp_relaxed_load(&__shared_owners_) + 1;
-    }
-};
-
-class _LIBCPP_TYPE_VIS __shared_weak_count
-    : private __shared_count
-{
-    long __shared_weak_owners_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
-        : __shared_count(__refs),
-          __shared_weak_owners_(__refs) {}
-protected:
-    virtual ~__shared_weak_count();
-
-public:
-#if defined(_LIBCPP_BUILDING_LIBRARY) && \
-    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
-    void __add_shared() _NOEXCEPT;
-    void __add_weak() _NOEXCEPT;
-    void __release_shared() _NOEXCEPT;
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_shared() _NOEXCEPT {
-      __shared_count::__add_shared();
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_weak() _NOEXCEPT {
-      __libcpp_atomic_refcount_increment(__shared_weak_owners_);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    void __release_shared() _NOEXCEPT {
-      if (__shared_count::__release_shared())
-        __release_weak();
-    }
-#endif
-    void __release_weak() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
-    __shared_weak_count* lock() _NOEXCEPT;
-
-    // Define the function out only if we build static libc++ without RTTI.
-    // Otherwise we may break clients who need to compile their projects with
-    // -fno-rtti and yet link against a libc++.dylib compiled
-    // without -fno-rtti.
-#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
-    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
-#endif
-private:
-    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
-};
-
-template <class _Tp, class _Dp, class _Alloc>
-class __shared_ptr_pointer
-    : public __shared_weak_count
-{
-    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
-        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
-
-#ifndef _LIBCPP_NO_RTTI
-    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
-#endif
-
-private:
-    virtual void __on_zero_shared() _NOEXCEPT;
-    virtual void __on_zero_shared_weak() _NOEXCEPT;
-};
-
-#ifndef _LIBCPP_NO_RTTI
-
-template <class _Tp, class _Dp, class _Alloc>
-const void*
-__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
-{
-    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr;
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template <class _Tp, class _Dp, class _Alloc>
-void
-__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
-{
-    __data_.first().second()(__data_.first().first());
-    __data_.first().second().~_Dp();
-}
-
-template <class _Tp, class _Dp, class _Alloc>
-void
-__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
-{
-    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
-    typedef allocator_traits<_Al> _ATraits;
-    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
-
-    _Al __a(__data_.second());
-    __data_.second().~_Alloc();
-    __a.deallocate(_PTraits::pointer_to(*this), 1);
-}
-
-template <class _Tp, class _Alloc>
-class __shared_ptr_emplace
-    : public __shared_weak_count
-{
-    __compressed_pair<_Alloc, _Tp> __data_;
-public:
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-    _LIBCPP_INLINE_VISIBILITY
-    __shared_ptr_emplace(_Alloc __a)
-        :  __data_(_VSTD::move(__a)) {}
-
-    template <class ..._Args>
-        _LIBCPP_INLINE_VISIBILITY
-        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
-            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
-                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-    _LIBCPP_INLINE_VISIBILITY
-    __shared_ptr_emplace(_Alloc __a)
-        :  __data_(__a) {}
-
-    template <class _A0>
-        _LIBCPP_INLINE_VISIBILITY
-        __shared_ptr_emplace(_Alloc __a, _A0& __a0)
-            :  __data_(__a, _Tp(__a0)) {}
-
-    template <class _A0, class _A1>
-        _LIBCPP_INLINE_VISIBILITY
-        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
-            :  __data_(__a, _Tp(__a0, __a1)) {}
-
-    template <class _A0, class _A1, class _A2>
-        _LIBCPP_INLINE_VISIBILITY
-        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
-            :  __data_(__a, _Tp(__a0, __a1, __a2)) {}
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-private:
-    virtual void __on_zero_shared() _NOEXCEPT;
-    virtual void __on_zero_shared_weak() _NOEXCEPT;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp* get() _NOEXCEPT {return _VSTD::addressof(__data_.second());}
-};
-
-template <class _Tp, class _Alloc>
-void
-__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
-{
-    __data_.second().~_Tp();
-}
-
-template <class _Tp, class _Alloc>
-void
-__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
-{
-    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
-    typedef allocator_traits<_Al> _ATraits;
-    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
-    _Al __a(__data_.first());
-    __data_.first().~_Alloc();
-    __a.deallocate(_PTraits::pointer_to(*this), 1);
-}
-
-struct __shared_ptr_dummy_rebind_allocator_type;
-template <>
-class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type>
-{
-public:
-    template <class _Other>
-    struct rebind
-    {
-        typedef allocator<_Other> other;
-    };
-};
-
-template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
-
-template<class _Tp>
-class _LIBCPP_TEMPLATE_VIS shared_ptr
-{
-public:
-    typedef _Tp element_type;
-
-#if _LIBCPP_STD_VER > 14
-    typedef weak_ptr<_Tp> weak_type;
-#endif
-private:
-    element_type*      __ptr_;
-    __shared_weak_count* __cntrl_;
-
-    struct __nat {int __for_bool_;};
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
-    template<class _Yp>
-        explicit shared_ptr(_Yp* __p,
-                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
-    template<class _Yp, class _Dp>
-        shared_ptr(_Yp* __p, _Dp __d,
-                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
-    template<class _Yp, class _Dp, class _Alloc>
-        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
-                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
-    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
-    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
-    template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
-    template<class _Yp>
-        _LIBCPP_INLINE_VISIBILITY
-        shared_ptr(const shared_ptr<_Yp>& __r,
-                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
-                       _NOEXCEPT;
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
-    template<class _Yp> _LIBCPP_INLINE_VISIBILITY  shared_ptr(shared_ptr<_Yp>&& __r,
-                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
-                       _NOEXCEPT;
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
-                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type= __nat());
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    template<class _Yp>
-        shared_ptr(auto_ptr<_Yp>&& __r,
-                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
-#else
-    template<class _Yp>
-        shared_ptr(auto_ptr<_Yp> __r,
-                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
-#endif
-#endif
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    template <class _Yp, class _Dp>
-        shared_ptr(unique_ptr<_Yp, _Dp>&&,
-                   typename enable_if
-                   <
-                       !is_lvalue_reference<_Dp>::value &&
-                       !is_array<_Yp>::value &&
-                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
-                       __nat
-                   >::type = __nat());
-    template <class _Yp, class _Dp>
-        shared_ptr(unique_ptr<_Yp, _Dp>&&,
-                   typename enable_if
-                   <
-                       is_lvalue_reference<_Dp>::value &&
-                       !is_array<_Yp>::value &&
-                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
-                       __nat
-                   >::type = __nat());
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    template <class _Yp, class _Dp>
-        shared_ptr(unique_ptr<_Yp, _Dp>,
-                   typename enable_if
-                   <
-                       !is_lvalue_reference<_Dp>::value &&
-                       !is_array<_Yp>::value &&
-                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
-                       __nat
-                   >::type = __nat());
-    template <class _Yp, class _Dp>
-        shared_ptr(unique_ptr<_Yp, _Dp>,
-                   typename enable_if
-                   <
-                       is_lvalue_reference<_Dp>::value &&
-                       !is_array<_Yp>::value &&
-                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
-                       __nat
-                   >::type = __nat());
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-    ~shared_ptr();
-
-    _LIBCPP_INLINE_VISIBILITY
-    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
-    template<class _Yp>
-        typename enable_if
-        <
-            is_convertible<_Yp*, element_type*>::value,
-            shared_ptr&
-        >::type
-        _LIBCPP_INLINE_VISIBILITY
-        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
-    template<class _Yp>
-        typename enable_if
-        <
-            is_convertible<_Yp*, element_type*>::value,
-            shared_ptr<_Tp>&
-        >::type
-        _LIBCPP_INLINE_VISIBILITY
-        operator=(shared_ptr<_Yp>&& __r);
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
-    template<class _Yp>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            !is_array<_Yp>::value &&
-            is_convertible<_Yp*, element_type*>::value,
-            shared_ptr
-        >::type&
-        operator=(auto_ptr<_Yp>&& __r);
-#endif
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
-    template<class _Yp>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            !is_array<_Yp>::value &&
-            is_convertible<_Yp*, element_type*>::value,
-            shared_ptr&
-        >::type
-        operator=(auto_ptr<_Yp> __r);
-#endif
-#endif
-    template <class _Yp, class _Dp>
-        typename enable_if
-        <
-            !is_array<_Yp>::value &&
-            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
-            shared_ptr&
-        >::type
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-        _LIBCPP_INLINE_VISIBILITY
-        operator=(unique_ptr<_Yp, _Dp>&& __r);
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-        _LIBCPP_INLINE_VISIBILITY
-        operator=(unique_ptr<_Yp, _Dp> __r);
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(shared_ptr& __r) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() _NOEXCEPT;
-    template<class _Yp>
-        typename enable_if
-        <
-            is_convertible<_Yp*, element_type*>::value,
-            void
-        >::type
-        _LIBCPP_INLINE_VISIBILITY
-        reset(_Yp* __p);
-    template<class _Yp, class _Dp>
-        typename enable_if
-        <
-            is_convertible<_Yp*, element_type*>::value,
-            void
-        >::type
-        _LIBCPP_INLINE_VISIBILITY
-        reset(_Yp* __p, _Dp __d);
-    template<class _Yp, class _Dp, class _Alloc>
-        typename enable_if
-        <
-            is_convertible<_Yp*, element_type*>::value,
-            void
-        >::type
-        _LIBCPP_INLINE_VISIBILITY
-        reset(_Yp* __p, _Dp __d, _Alloc __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    element_type* get() const _NOEXCEPT {return __ptr_;}
-    _LIBCPP_INLINE_VISIBILITY
-    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
-        {return *__ptr_;}
-    _LIBCPP_INLINE_VISIBILITY
-    element_type* operator->() const _NOEXCEPT {return __ptr_;}
-    _LIBCPP_INLINE_VISIBILITY
-    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool unique() const _NOEXCEPT {return use_count() == 1;}
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
-    template <class _Up>
-        _LIBCPP_INLINE_VISIBILITY
-        bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT
-        {return __cntrl_ < __p.__cntrl_;}
-    template <class _Up>
-        _LIBCPP_INLINE_VISIBILITY
-        bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT
-        {return __cntrl_ < __p.__cntrl_;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool
-    __owner_equivalent(const shared_ptr& __p) const
-        {return __cntrl_ == __p.__cntrl_;}
-
-#ifndef _LIBCPP_NO_RTTI
-    template <class _Dp>
-        _LIBCPP_INLINE_VISIBILITY
-        _Dp* __get_deleter() const _NOEXCEPT
-            {return static_cast<_Dp*>(__cntrl_
-                    ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp)))
-                      : nullptr);}
-#endif  // _LIBCPP_NO_RTTI
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-    template<class ..._Args>
-        static
-        shared_ptr<_Tp>
-        make_shared(_Args&& ...__args);
-
-    template<class _Alloc, class ..._Args>
-        static
-        shared_ptr<_Tp>
-        allocate_shared(const _Alloc& __a, _Args&& ...__args);
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-    static shared_ptr<_Tp> make_shared();
-
-    template<class _A0>
-        static shared_ptr<_Tp> make_shared(_A0&);
-
-    template<class _A0, class _A1>
-        static shared_ptr<_Tp> make_shared(_A0&, _A1&);
-
-    template<class _A0, class _A1, class _A2>
-        static shared_ptr<_Tp> make_shared(_A0&, _A1&, _A2&);
-
-    template<class _Alloc>
-        static shared_ptr<_Tp>
-        allocate_shared(const _Alloc& __a);
-
-    template<class _Alloc, class _A0>
-        static shared_ptr<_Tp>
-        allocate_shared(const _Alloc& __a, _A0& __a0);
-
-    template<class _Alloc, class _A0, class _A1>
-        static shared_ptr<_Tp>
-        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1);
-
-    template<class _Alloc, class _A0, class _A1, class _A2>
-        static shared_ptr<_Tp>
-        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2);
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-private:
-    template <class _Yp, bool = is_function<_Yp>::value>
-        struct __shared_ptr_default_allocator
-        {
-            typedef allocator<_Yp> type;
-        };
-
-    template <class _Yp>
-        struct __shared_ptr_default_allocator<_Yp, true>
-        {
-            typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
-        };
-
-    template <class _Yp, class _OrigPtr>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if<is_convertible<_OrigPtr*,
-                                          const enable_shared_from_this<_Yp>*
-        >::value,
-            void>::type
-        __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
-                           _OrigPtr* __ptr) _NOEXCEPT
-        {
-            typedef typename remove_cv<_Yp>::type _RawYp;
-            if (__e && __e->__weak_this_.expired())
-            {
-                __e->__weak_this_ = shared_ptr<_RawYp>(*this,
-                    const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
-            }
-        }
-
-    _LIBCPP_INLINE_VISIBILITY void __enable_weak_this(...) _NOEXCEPT {}
-
-    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
-    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
-};
-
-
-template<class _Tp>
-inline
-_LIBCPP_CONSTEXPR
-shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
-    : __ptr_(0),
-      __cntrl_(0)
-{
-}
-
-template<class _Tp>
-inline
-_LIBCPP_CONSTEXPR
-shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
-    : __ptr_(0),
-      __cntrl_(0)
-{
-}
-
-template<class _Tp>
-template<class _Yp>
-shared_ptr<_Tp>::shared_ptr(_Yp* __p,
-                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-    : __ptr_(__p)
-{
-    unique_ptr<_Yp> __hold(__p);
-    typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
-    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, _AllocT > _CntrlBlk;
-    __cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), _AllocT());
-    __hold.release();
-    __enable_weak_this(__p, __p);
-}
-
-template<class _Tp>
-template<class _Yp, class _Dp>
-shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
-                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-    : __ptr_(__p)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
-        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
-        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
-        __enable_weak_this(__p, __p);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __d(__p);
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template<class _Tp>
-template<class _Dp>
-shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
-    : __ptr_(0)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
-        typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
-        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __d(__p);
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template<class _Tp>
-template<class _Yp, class _Dp, class _Alloc>
-shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
-                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-    : __ptr_(__p)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
-        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
-        typedef __allocator_destructor<_A2> _D2;
-        _A2 __a2(__a);
-        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
-        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
-            _CntrlBlk(__p, __d, __a);
-        __cntrl_ = _VSTD::addressof(*__hold2.release());
-        __enable_weak_this(__p, __p);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __d(__p);
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template<class _Tp>
-template<class _Dp, class _Alloc>
-shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
-    : __ptr_(0)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
-        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
-        typedef __allocator_destructor<_A2> _D2;
-        _A2 __a2(__a);
-        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
-        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
-            _CntrlBlk(__p, __d, __a);
-        __cntrl_ = _VSTD::addressof(*__hold2.release());
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __d(__p);
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
-    : __ptr_(__p),
-      __cntrl_(__r.__cntrl_)
-{
-    if (__cntrl_)
-        __cntrl_->__add_shared();
-}
-
-template<class _Tp>
-inline
-shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_)
-{
-    if (__cntrl_)
-        __cntrl_->__add_shared();
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
-                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-         _NOEXCEPT
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_)
-{
-    if (__cntrl_)
-        __cntrl_->__add_shared();
-}
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template<class _Tp>
-inline
-shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_)
-{
-    __r.__ptr_ = 0;
-    __r.__cntrl_ = 0;
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
-                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-         _NOEXCEPT
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_)
-{
-    __r.__ptr_ = 0;
-    __r.__cntrl_ = 0;
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
-template<class _Tp>
-template<class _Yp>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
-#else
-shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp> __r,
-#endif
-                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-    : __ptr_(__r.get())
-{
-    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
-    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
-    __enable_weak_this(__r.get(), __r.get());
-    __r.release();
-}
-#endif
-
-template<class _Tp>
-template <class _Yp, class _Dp>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
-#else
-shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
-#endif
-                            typename enable_if
-                            <
-                                !is_lvalue_reference<_Dp>::value &&
-                                !is_array<_Yp>::value &&
-                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
-                                __nat
-                            >::type)
-    : __ptr_(__r.get())
-{
-#if _LIBCPP_STD_VER > 11
-    if (__ptr_ == nullptr)
-        __cntrl_ = nullptr;
-    else
-#endif
-    {
-        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
-        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
-        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), _AllocT());
-        __enable_weak_this(__r.get(), __r.get());
-    }
-    __r.release();
-}
-
-template<class _Tp>
-template <class _Yp, class _Dp>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
-#else
-shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
-#endif
-                            typename enable_if
-                            <
-                                is_lvalue_reference<_Dp>::value &&
-                                !is_array<_Yp>::value &&
-                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
-                                __nat
-                            >::type)
-    : __ptr_(__r.get())
-{
-#if _LIBCPP_STD_VER > 11
-    if (__ptr_ == nullptr)
-        __cntrl_ = nullptr;
-    else
-#endif
-    {
-        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
-        typedef __shared_ptr_pointer<_Yp*,
-                                     reference_wrapper<typename remove_reference<_Dp>::type>,
-                                     _AllocT > _CntrlBlk;
-        __cntrl_ = new _CntrlBlk(__r.get(), ref(__r.get_deleter()), _AllocT());
-        __enable_weak_this(__r.get(), __r.get());
-    }
-    __r.release();
-}
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-template<class _Tp>
-template<class ..._Args>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::make_shared(_Args&& ...__args)
-{
-    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in make_shared" );
-    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
-    typedef allocator<_CntrlBlk> _A2;
-    typedef __allocator_destructor<_A2> _D2;
-    _A2 __a2;
-    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
-    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = __hold2.release();
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-template<class _Tp>
-template<class _Alloc, class ..._Args>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _Args&& ...__args)
-{
-    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in allocate_shared" );
-    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
-    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
-    typedef __allocator_destructor<_A2> _D2;
-    _A2 __a2(__a);
-    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
-    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
-        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-template<class _Tp>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::make_shared()
-{
-    static_assert((is_constructible<_Tp>::value), "Can't construct object in make_shared" );
-    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
-    typedef allocator<_CntrlBlk> _Alloc2;
-    typedef __allocator_destructor<_Alloc2> _D2;
-    _Alloc2 __alloc2;
-    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
-    ::new(__hold2.get()) _CntrlBlk(__alloc2);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = __hold2.release();
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-template<class _Tp>
-template<class _A0>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::make_shared(_A0& __a0)
-{
-    static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in make_shared" );
-    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
-    typedef allocator<_CntrlBlk> _Alloc2;
-    typedef __allocator_destructor<_Alloc2> _D2;
-    _Alloc2 __alloc2;
-    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
-    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = __hold2.release();
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-template<class _Tp>
-template<class _A0, class _A1>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1)
-{
-    static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in make_shared" );
-    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
-    typedef allocator<_CntrlBlk> _Alloc2;
-    typedef __allocator_destructor<_Alloc2> _D2;
-    _Alloc2 __alloc2;
-    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
-    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = __hold2.release();
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-template<class _Tp>
-template<class _A0, class _A1, class _A2>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
-{
-    static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in make_shared" );
-    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
-    typedef allocator<_CntrlBlk> _Alloc2;
-    typedef __allocator_destructor<_Alloc2> _D2;
-    _Alloc2 __alloc2;
-    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
-    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1, __a2);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = __hold2.release();
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-template<class _Tp>
-template<class _Alloc>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::allocate_shared(const _Alloc& __a)
-{
-    static_assert((is_constructible<_Tp>::value), "Can't construct object in allocate_shared" );
-    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
-    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
-    typedef __allocator_destructor<_Alloc2> _D2;
-    _Alloc2 __alloc2(__a);
-    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
-    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
-        _CntrlBlk(__a);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-template<class _Tp>
-template<class _Alloc, class _A0>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0)
-{
-    static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in allocate_shared" );
-    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
-    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
-    typedef __allocator_destructor<_Alloc2> _D2;
-    _Alloc2 __alloc2(__a);
-    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
-    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
-        _CntrlBlk(__a, __a0);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-template<class _Tp>
-template<class _Alloc, class _A0, class _A1>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
-{
-    static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in allocate_shared" );
-    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
-    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
-    typedef __allocator_destructor<_Alloc2> _D2;
-    _Alloc2 __alloc2(__a);
-    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
-    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
-        _CntrlBlk(__a, __a0, __a1);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-template<class _Tp>
-template<class _Alloc, class _A0, class _A1, class _A2>
-shared_ptr<_Tp>
-shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
-{
-    static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in allocate_shared" );
-    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
-    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
-    typedef __allocator_destructor<_Alloc2> _D2;
-    _Alloc2 __alloc2(__a);
-    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
-    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
-        _CntrlBlk(__a, __a0, __a1, __a2);
-    shared_ptr<_Tp> __r;
-    __r.__ptr_ = __hold2.get()->get();
-    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
-    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
-    return __r;
-}
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-template<class _Tp>
-shared_ptr<_Tp>::~shared_ptr()
-{
-    if (__cntrl_)
-        __cntrl_->__release_shared();
-}
-
-template<class _Tp>
-inline
-shared_ptr<_Tp>&
-shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
-{
-    shared_ptr(__r).swap(*this);
-    return *this;
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-typename enable_if
-<
-    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
-    shared_ptr<_Tp>&
->::type
-shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
-{
-    shared_ptr(__r).swap(*this);
-    return *this;
-}
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template<class _Tp>
-inline
-shared_ptr<_Tp>&
-shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
-{
-    shared_ptr(_VSTD::move(__r)).swap(*this);
-    return *this;
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-typename enable_if
-<
-    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
-    shared_ptr<_Tp>&
->::type
-shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
-{
-    shared_ptr(_VSTD::move(__r)).swap(*this);
-    return *this;
-}
-
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
-template<class _Tp>
-template<class _Yp>
-inline
-typename enable_if
-<
-    !is_array<_Yp>::value &&
-    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
-    shared_ptr<_Tp>
->::type&
-shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
-{
-    shared_ptr(_VSTD::move(__r)).swap(*this);
-    return *this;
-}
-#endif
-
-template<class _Tp>
-template <class _Yp, class _Dp>
-inline
-typename enable_if
-<
-    !is_array<_Yp>::value &&
-    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
-                   typename shared_ptr<_Tp>::element_type*>::value,
-    shared_ptr<_Tp>&
->::type
-shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
-{
-    shared_ptr(_VSTD::move(__r)).swap(*this);
-    return *this;
-}
-
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
-template<class _Tp>
-template<class _Yp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    !is_array<_Yp>::value &&
-    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
-    shared_ptr<_Tp>&
->::type
-shared_ptr<_Tp>::operator=(auto_ptr<_Yp> __r)
-{
-    shared_ptr(__r).swap(*this);
-    return *this;
-}
-#endif
-
-template<class _Tp>
-template <class _Yp, class _Dp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    !is_array<_Yp>::value &&
-    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
-                   typename shared_ptr<_Tp>::element_type*>::value,
-    shared_ptr<_Tp>&
->::type
-shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp> __r)
-{
-    shared_ptr(_VSTD::move(__r)).swap(*this);
-    return *this;
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template<class _Tp>
-inline
-void
-shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
-{
-    _VSTD::swap(__ptr_, __r.__ptr_);
-    _VSTD::swap(__cntrl_, __r.__cntrl_);
-}
-
-template<class _Tp>
-inline
-void
-shared_ptr<_Tp>::reset() _NOEXCEPT
-{
-    shared_ptr().swap(*this);
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-typename enable_if
-<
-    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
-    void
->::type
-shared_ptr<_Tp>::reset(_Yp* __p)
-{
-    shared_ptr(__p).swap(*this);
-}
-
-template<class _Tp>
-template<class _Yp, class _Dp>
-inline
-typename enable_if
-<
-    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
-    void
->::type
-shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
-{
-    shared_ptr(__p, __d).swap(*this);
-}
-
-template<class _Tp>
-template<class _Yp, class _Dp, class _Alloc>
-inline
-typename enable_if
-<
-    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
-    void
->::type
-shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
-{
-    shared_ptr(__p, __d, __a).swap(*this);
-}
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-template<class _Tp, class ..._Args>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    !is_array<_Tp>::value,
-    shared_ptr<_Tp>
->::type
-make_shared(_Args&& ...__args)
-{
-    return shared_ptr<_Tp>::make_shared(_VSTD::forward<_Args>(__args)...);
-}
-
-template<class _Tp, class _Alloc, class ..._Args>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    !is_array<_Tp>::value,
-    shared_ptr<_Tp>
->::type
-allocate_shared(const _Alloc& __a, _Args&& ...__args)
-{
-    return shared_ptr<_Tp>::allocate_shared(__a, _VSTD::forward<_Args>(__args)...);
-}
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-shared_ptr<_Tp>
-make_shared()
-{
-    return shared_ptr<_Tp>::make_shared();
-}
-
-template<class _Tp, class _A0>
-inline _LIBCPP_INLINE_VISIBILITY
-shared_ptr<_Tp>
-make_shared(_A0& __a0)
-{
-    return shared_ptr<_Tp>::make_shared(__a0);
-}
-
-template<class _Tp, class _A0, class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-shared_ptr<_Tp>
-make_shared(_A0& __a0, _A1& __a1)
-{
-    return shared_ptr<_Tp>::make_shared(__a0, __a1);
-}
-
-template<class _Tp, class _A0, class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-shared_ptr<_Tp>
-make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
-{
-    return shared_ptr<_Tp>::make_shared(__a0, __a1, __a2);
-}
-
-template<class _Tp, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-shared_ptr<_Tp>
-allocate_shared(const _Alloc& __a)
-{
-    return shared_ptr<_Tp>::allocate_shared(__a);
-}
-
-template<class _Tp, class _Alloc, class _A0>
-inline _LIBCPP_INLINE_VISIBILITY
-shared_ptr<_Tp>
-allocate_shared(const _Alloc& __a, _A0& __a0)
-{
-    return shared_ptr<_Tp>::allocate_shared(__a, __a0);
-}
-
-template<class _Tp, class _Alloc, class _A0, class _A1>
-inline _LIBCPP_INLINE_VISIBILITY
-shared_ptr<_Tp>
-allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
-{
-    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1);
-}
-
-template<class _Tp, class _Alloc, class _A0, class _A1, class _A2>
-inline _LIBCPP_INLINE_VISIBILITY
-shared_ptr<_Tp>
-allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
-{
-    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1, __a2);
-}
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
-{
-    return __x.get() == __y.get();
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
-{
-    return !(__x == __y);
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
-{
-#if _LIBCPP_STD_VER <= 11
-    typedef typename common_type<_Tp*, _Up*>::type _Vp;
-    return less<_Vp>()(__x.get(), __y.get());
-#else
-    return less<>()(__x.get(), __y.get());
-#endif
-
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
-{
-    return __y < __x;
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
-{
-    return !(__y < __x);
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
-{
-    return !(__x < __y);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
-{
-    return !__x;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
-{
-    return !__x;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
-{
-    return static_cast<bool>(__x);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
-{
-    return static_cast<bool>(__x);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
-{
-    return less<_Tp*>()(__x.get(), nullptr);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
-{
-    return less<_Tp*>()(nullptr, __x.get());
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
-{
-    return nullptr < __x;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
-{
-    return __x < nullptr;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
-{
-    return !(nullptr < __x);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
-{
-    return !(__x < nullptr);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
-{
-    return !(__x < nullptr);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
-{
-    return !(nullptr < __x);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
-{
-    __x.swap(__y);
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    !is_array<_Tp>::value && !is_array<_Up>::value,
-    shared_ptr<_Tp>
->::type
-static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
-{
-    return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get()));
-}
-
-template<class _Tp, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    !is_array<_Tp>::value && !is_array<_Up>::value,
-    shared_ptr<_Tp>
->::type
-dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
-{
-    _Tp* __p = dynamic_cast<_Tp*>(__r.get());
-    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
-}
-
-template<class _Tp, class _Up>
-typename enable_if
-<
-    is_array<_Tp>::value == is_array<_Up>::value,
-    shared_ptr<_Tp>
->::type
-const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
-{
-    typedef typename remove_extent<_Tp>::type _RTp;
-    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
-}
-
-#ifndef _LIBCPP_NO_RTTI
-
-template<class _Dp, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Dp*
-get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
-{
-    return __p.template __get_deleter<_Dp>();
-}
-
-#endif  // _LIBCPP_NO_RTTI
-
-template<class _Tp>
-class _LIBCPP_TEMPLATE_VIS weak_ptr
-{
-public:
-    typedef _Tp element_type;
-private:
-    element_type*        __ptr_;
-    __shared_weak_count* __cntrl_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
-    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r,
-                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
-                        _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
-    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r,
-                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
-                         _NOEXCEPT;
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    _LIBCPP_INLINE_VISIBILITY
-    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
-    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r,
-                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
-                         _NOEXCEPT;
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    ~weak_ptr();
-
-    _LIBCPP_INLINE_VISIBILITY
-    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
-    template<class _Yp>
-        typename enable_if
-        <
-            is_convertible<_Yp*, element_type*>::value,
-            weak_ptr&
-        >::type
-        _LIBCPP_INLINE_VISIBILITY
-        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-    _LIBCPP_INLINE_VISIBILITY
-    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
-    template<class _Yp>
-        typename enable_if
-        <
-            is_convertible<_Yp*, element_type*>::value,
-            weak_ptr&
-        >::type
-        _LIBCPP_INLINE_VISIBILITY
-        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-    template<class _Yp>
-        typename enable_if
-        <
-            is_convertible<_Yp*, element_type*>::value,
-            weak_ptr&
-        >::type
-        _LIBCPP_INLINE_VISIBILITY
-        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(weak_ptr& __r) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    long use_count() const _NOEXCEPT
-        {return __cntrl_ ? __cntrl_->use_count() : 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool expired() const _NOEXCEPT
-        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
-    shared_ptr<_Tp> lock() const _NOEXCEPT;
-    template<class _Up>
-        _LIBCPP_INLINE_VISIBILITY
-        bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT
-        {return __cntrl_ < __r.__cntrl_;}
-    template<class _Up>
-        _LIBCPP_INLINE_VISIBILITY
-        bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT
-        {return __cntrl_ < __r.__cntrl_;}
-
-    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
-    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
-};
-
-template<class _Tp>
-inline
-_LIBCPP_CONSTEXPR
-weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
-    : __ptr_(0),
-      __cntrl_(0)
-{
-}
-
-template<class _Tp>
-inline
-weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_)
-{
-    if (__cntrl_)
-        __cntrl_->__add_weak();
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
-                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
-                         _NOEXCEPT
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_)
-{
-    if (__cntrl_)
-        __cntrl_->__add_weak();
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
-                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
-         _NOEXCEPT
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_)
-{
-    if (__cntrl_)
-        __cntrl_->__add_weak();
-}
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template<class _Tp>
-inline
-weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_)
-{
-    __r.__ptr_ = 0;
-    __r.__cntrl_ = 0;
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
-                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
-         _NOEXCEPT
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_)
-{
-    __r.__ptr_ = 0;
-    __r.__cntrl_ = 0;
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template<class _Tp>
-weak_ptr<_Tp>::~weak_ptr()
-{
-    if (__cntrl_)
-        __cntrl_->__release_weak();
-}
-
-template<class _Tp>
-inline
-weak_ptr<_Tp>&
-weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
-{
-    weak_ptr(__r).swap(*this);
-    return *this;
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-typename enable_if
-<
-    is_convertible<_Yp*, _Tp*>::value,
-    weak_ptr<_Tp>&
->::type
-weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
-{
-    weak_ptr(__r).swap(*this);
-    return *this;
-}
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template<class _Tp>
-inline
-weak_ptr<_Tp>&
-weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
-{
-    weak_ptr(_VSTD::move(__r)).swap(*this);
-    return *this;
-}
-
-template<class _Tp>
-template<class _Yp>
-inline
-typename enable_if
-<
-    is_convertible<_Yp*, _Tp*>::value,
-    weak_ptr<_Tp>&
->::type
-weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
-{
-    weak_ptr(_VSTD::move(__r)).swap(*this);
-    return *this;
-}
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template<class _Tp>
-template<class _Yp>
-inline
-typename enable_if
-<
-    is_convertible<_Yp*, _Tp*>::value,
-    weak_ptr<_Tp>&
->::type
-weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
-{
-    weak_ptr(__r).swap(*this);
-    return *this;
-}
-
-template<class _Tp>
-inline
-void
-weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
-{
-    _VSTD::swap(__ptr_, __r.__ptr_);
-    _VSTD::swap(__cntrl_, __r.__cntrl_);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
-{
-    __x.swap(__y);
-}
-
-template<class _Tp>
-inline
-void
-weak_ptr<_Tp>::reset() _NOEXCEPT
-{
-    weak_ptr().swap(*this);
-}
-
-template<class _Tp>
-template<class _Yp>
-shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
-                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
-    : __ptr_(__r.__ptr_),
-      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
-{
-    if (__cntrl_ == 0)
-        __throw_bad_weak_ptr();
-}
-
-template<class _Tp>
-shared_ptr<_Tp>
-weak_ptr<_Tp>::lock() const _NOEXCEPT
-{
-    shared_ptr<_Tp> __r;
-    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
-    if (__r.__cntrl_)
-        __r.__ptr_ = __ptr_;
-    return __r;
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp = void> struct owner_less;
-#else
-template <class _Tp> struct owner_less;
-#endif
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> >
-    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
-{
-    typedef bool result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> >
-    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
-{
-    typedef bool result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-};
-
-#if _LIBCPP_STD_VER > 14
-template <>
-struct _LIBCPP_TEMPLATE_VIS owner_less<void>
-{
-    template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-    template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-    template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-    template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
-        {return __x.owner_before(__y);}
-    typedef void is_transparent;
-};
-#endif
-
-template<class _Tp>
-class _LIBCPP_TEMPLATE_VIS enable_shared_from_this
-{
-    mutable weak_ptr<_Tp> __weak_this_;
-protected:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    enable_shared_from_this() _NOEXCEPT {}
-    _LIBCPP_INLINE_VISIBILITY
-    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
-    _LIBCPP_INLINE_VISIBILITY
-    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
-        {return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    ~enable_shared_from_this() {}
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    shared_ptr<_Tp> shared_from_this()
-        {return shared_ptr<_Tp>(__weak_this_);}
-    _LIBCPP_INLINE_VISIBILITY
-    shared_ptr<_Tp const> shared_from_this() const
-        {return shared_ptr<const _Tp>(__weak_this_);}
-
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY
-    weak_ptr<_Tp> weak_from_this() _NOEXCEPT
-       { return __weak_this_; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT
-        { return __weak_this_; }
-#endif // _LIBCPP_STD_VER > 14
-
-    template <class _Up> friend class shared_ptr;
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> >
-{
-    typedef shared_ptr<_Tp>      argument_type;
-    typedef size_t               result_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
-    {
-        return hash<_Tp*>()(__ptr.get());
-    }
-};
-
-template<class _CharT, class _Traits, class _Yp>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
-
-
-#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
-
-class _LIBCPP_TYPE_VIS __sp_mut
-{
-    void* __lx;
-public:
-    void lock() _NOEXCEPT;
-    void unlock() _NOEXCEPT;
-
-private:
-    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
-    __sp_mut(const __sp_mut&);
-    __sp_mut& operator=(const __sp_mut&);
-
-    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
-};
-
-_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-__sp_mut& __get_sp_mut(const void*);
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-atomic_is_lock_free(const shared_ptr<_Tp>*)
-{
-    return false;
-}
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-shared_ptr<_Tp>
-atomic_load(const shared_ptr<_Tp>* __p)
-{
-    __sp_mut& __m = __get_sp_mut(__p);
-    __m.lock();
-    shared_ptr<_Tp> __q = *__p;
-    __m.unlock();
-    return __q;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-shared_ptr<_Tp>
-atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
-{
-    return atomic_load(__p);
-}
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-void
-atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
-{
-    __sp_mut& __m = __get_sp_mut(__p);
-    __m.lock();
-    __p->swap(__r);
-    __m.unlock();
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-void
-atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
-{
-    atomic_store(__p, __r);
-}
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-shared_ptr<_Tp>
-atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
-{
-    __sp_mut& __m = __get_sp_mut(__p);
-    __m.lock();
-    __p->swap(__r);
-    __m.unlock();
-    return __r;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-shared_ptr<_Tp>
-atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
-{
-    return atomic_exchange(__p, __r);
-}
-
-template <class _Tp>
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-bool
-atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
-{
-    shared_ptr<_Tp> __temp;
-    __sp_mut& __m = __get_sp_mut(__p);
-    __m.lock();
-    if (__p->__owner_equivalent(*__v))
-    {
-        _VSTD::swap(__temp, *__p);
-        *__p = __w;
-        __m.unlock();
-        return true;
-    }
-    _VSTD::swap(__temp, *__v);
-    *__v = *__p;
-    __m.unlock();
-    return false;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-bool
-atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
-{
-    return atomic_compare_exchange_strong(__p, __v, __w);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-bool
-atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
-                                        shared_ptr<_Tp> __w, memory_order, memory_order)
-{
-    return atomic_compare_exchange_strong(__p, __v, __w);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
-bool
-atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
-                                      shared_ptr<_Tp> __w, memory_order, memory_order)
-{
-    return atomic_compare_exchange_weak(__p, __v, __w);
-}
-
-#endif  // !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
-
-//enum class
-#if defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE)
-# ifndef _LIBCPP_CXX03_LANG
-enum class pointer_safety : unsigned char {
-  relaxed,
-  preferred,
-  strict
-};
-# endif
-#else
-struct _LIBCPP_TYPE_VIS pointer_safety
-{
-    enum __lx
-    {
-        relaxed,
-        preferred,
-        strict
-    };
-
-    __lx __v_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    pointer_safety() : __v_() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    pointer_safety(__lx __v) : __v_(__v) {}
-    _LIBCPP_INLINE_VISIBILITY
-    operator int() const {return __v_;}
-};
-#endif
-
-#if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) && \
-    defined(_LIBCPP_BUILDING_LIBRARY)
-_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
-#else
-// This function is only offered in C++03 under ABI v1.
-# if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) || !defined(_LIBCPP_CXX03_LANG)
-inline _LIBCPP_INLINE_VISIBILITY
-pointer_safety get_pointer_safety() _NOEXCEPT {
-  return pointer_safety::relaxed;
-}
-# endif
-#endif
-
-
-_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
-_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
-_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
-_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-undeclare_reachable(_Tp* __p)
-{
-    return static_cast<_Tp*>(__undeclare_reachable(__p));
-}
-
-_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
-
-// --- Helper for container swap --
-template <typename _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
-#if _LIBCPP_STD_VER >= 14
-    _NOEXCEPT
-#else
-    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
-#endif
-{
-    __swap_allocator(__a1, __a2,
-      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
-}
-
-template <typename _Alloc>
-_LIBCPP_INLINE_VISIBILITY
-void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
-#if _LIBCPP_STD_VER >= 14
-    _NOEXCEPT
-#else
-    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
-#endif
-{
-    using _VSTD::swap;
-    swap(__a1, __a2);
-}
-
-template <typename _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
-
-template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
-struct __noexcept_move_assign_container : public integral_constant<bool,
-    _Traits::propagate_on_container_move_assignment::value
-#if _LIBCPP_STD_VER > 14
-        || _Traits::is_always_equal::value
-#else
-        && is_nothrow_move_assignable<_Alloc>::value
-#endif
-    > {};
-
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-template <class _Tp, class _Alloc>
-struct __temp_value {
-    typedef allocator_traits<_Alloc> _Traits;
-
-    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
-    _Alloc &__a;
-
-    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
-    _Tp &   get() { return *__addr(); }
-
-    template<class... _Args>
-    _LIBCPP_NO_CFI
-    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
-      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
-                         _VSTD::forward<_Args>(__args)...);
-    }
-
-    ~__temp_value() { _Traits::destroy(__a, __addr()); }
-    };
-#endif
-
-template<typename _Alloc, typename = void, typename = void>
-struct __is_allocator : false_type {};
-
-template<typename _Alloc>
-struct __is_allocator<_Alloc,
-       typename __void_t<typename _Alloc::value_type>::type,
-       typename __void_t<decltype(_VSTD::declval<_Alloc&>().allocate(size_t(0)))>::type
-     >
-   : true_type {};
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_MEMORY
diff --git a/lib/libcxx/include/module.modulemap b/lib/libcxx/include/module.modulemap
deleted file mode 100644
index 6d88f52113c..00000000000
--- a/lib/libcxx/include/module.modulemap
+++ /dev/null
@@ -1,605 +0,0 @@
-// define the module for __config outside of the top level 'std' module
-// since __config may be included from C headers which may create an
-// include cycle.
-module std_config [system] [extern_c] {
-    header "__config"
-}
-
-module std [system] {
-  export std_config
-  // FIXME: The standard does not require that each of these submodules
-  // re-exports its imported modules. We should provide an alternative form of
-  // export that issues a warning if a name from the submodule is used, and
-  // use that to provide a 'strict mode' for libc++.
-
-  // Deprecated C-compatibility headers. These can all be included from within
-  // an 'extern "C"' context.
-  module depr [extern_c] {
-    // <assert.h> provided by C library.
-    module ctype_h {
-      header "ctype.h"
-      export *
-    }
-    module errno_h {
-      header "errno.h"
-      export *
-    }
-    // <fenv.h> provided by C library.
-    // <float.h> provided by compiler or C library.
-    module inttypes_h {
-      header "inttypes.h"
-      export stdint_h
-      export *
-    }
-    // <iso646.h> provided by compiler.
-    // <limits.h> provided by compiler or C library.
-    module locale_h {
-      header "locale.h"
-      export *
-    }
-    module math_h {
-      header "math.h"
-      export *
-    }
-    module setjmp_h {
-      header "setjmp.h"
-      export *
-    }
-    // FIXME: <stdalign.h> is missing.
-    // <signal.h> provided by C library.
-    // <stdarg.h> provided by compiler.
-    // <stdbool.h> provided by compiler.
-    module stddef_h {
-      // <stddef.h>'s __need_* macros require textual inclusion.
-      textual header "stddef.h"
-    }
-    module stdint_h {
-      header "stdint.h"
-      export *
-      // FIXME: This module only exists on OS X and for some reason the
-      // wildcard above doesn't export it.
-      export Darwin.C.stdint
-    }
-    module stdio_h {
-      // <stdio.h>'s __need_* macros require textual inclusion.
-      textual header "stdio.h"
-      export *
-      export Darwin.C.stdio
-    }
-    module stdlib_h {
-      // <stdlib.h>'s __need_* macros require textual inclusion.
-      textual header "stdlib.h"
-      export *
-    }
-    module string_h {
-      header "string.h"
-      export *
-    }
-    // FIXME: <uchar.h> is missing.
-    // <time.h> provided by C library.
-    module wchar_h {
-      // <wchar.h>'s __need_* macros require textual inclusion.
-      textual header "wchar.h"
-      export *
-    }
-    module wctype_h {
-      header "wctype.h"
-      export *
-    }
-  }
-
-  // <complex.h> and <tgmath.h> are not C headers in any real sense, do not
-  // allow their use in extern "C" contexts.
-  module complex_h {
-    header "complex.h"
-    export ccomplex
-    export *
-  }
-  module tgmath_h {
-    header "tgmath.h"
-    export ccomplex
-    export cmath
-    export *
-  }
-
-  // C compatibility headers.
-  module compat {
-    module cassert {
-      // <cassert>'s use of NDEBUG requires textual inclusion.
-      textual header "cassert"
-    }
-    module ccomplex {
-      header "ccomplex"
-      export complex
-      export *
-    }
-    module cctype {
-      header "cctype"
-      export *
-    }
-    module cerrno {
-      header "cerrno"
-      export *
-    }
-    module cfenv {
-      header "cfenv"
-      export *
-    }
-    module cfloat {
-      header "cfloat"
-      export *
-    }
-    module cinttypes {
-      header "cinttypes"
-      export cstdint
-      export *
-    }
-    module ciso646 {
-      header "ciso646"
-      export *
-    }
-    module climits {
-      header "climits"
-      export *
-    }
-    module clocale {
-      header "clocale"
-      export *
-    }
-    module cmath {
-      header "cmath"
-      export *
-    }
-    module csetjmp {
-      header "csetjmp"
-      export *
-    }
-    module csignal {
-      header "csignal"
-      export *
-    }
-    // FIXME: <cstdalign> is missing.
-    module cstdarg {
-      header "cstdarg"
-      export *
-    }
-    module cstdbool {
-      header "cstdbool"
-      export *
-    }
-    module cstddef {
-      header "cstddef"
-      export *
-    }
-    module cstdint {
-      header "cstdint"
-      export depr.stdint_h
-      export *
-    }
-    module cstdio {
-      header "cstdio"
-      export *
-    }
-    module cstdlib {
-      header "cstdlib"
-      export *
-    }
-    module cstring {
-      header "cstring"
-      export *
-    }
-    module ctgmath {
-      header "ctgmath"
-      export ccomplex
-      export cmath
-      export *
-    }
-    module ctime {
-      header "ctime"
-      export *
-    }
-    // FIXME: <cuchar> is missing.
-    module cwchar {
-      header "cwchar"
-      export depr.stdio_h
-      export *
-    }
-    module cwctype {
-      header "cwctype"
-      export *
-    }
-  }
-
-  module algorithm {
-    header "algorithm"
-    export initializer_list
-    export *
-  }
-  module any {
-    header "any"
-    export *
-  }
-  module array {
-    header "array"
-    export initializer_list
-    export *
-  }
-  module atomic {
-    header "atomic"
-    export *
-  }
-  module bit {
-    header "bit"
-    export *
-  }
-  module bitset {
-    header "bitset"
-    export string
-    export iosfwd
-    export *
-  }
-  // No submodule for cassert. It fundamentally needs repeated, textual inclusion.
-  module charconv {
-    header "charconv"
-    export *
-  }
-  module chrono {
-    header "chrono"
-    export *
-  }
-  module codecvt {
-    header "codecvt"
-    export *
-  }
-  module compare {
-    header "compare"
-    export *
-  }
-  module complex {
-    header "complex"
-    export *
-  }
-  module condition_variable {
-    header "condition_variable"
-    export *
-  }
-  module deque {
-    header "deque"
-    export initializer_list
-    export *
-  }
-  module exception {
-    header "exception"
-    export *
-  }
-  module filesystem {
-    header "filesystem"
-    export *
-  }
-  module forward_list {
-    header "forward_list"
-    export initializer_list
-    export *
-  }
-  module fstream {
-    header "fstream"
-    export *
-  }
-  module functional {
-    header "functional"
-    export *
-  }
-  module future {
-    header "future"
-    export *
-  }
-  module initializer_list {
-    header "initializer_list"
-    export *
-  }
-  module iomanip {
-    header "iomanip"
-    export *
-  }
-  module ios {
-    header "ios"
-    export iosfwd
-    export *
-  }
-  module iosfwd {
-    header "iosfwd"
-    export *
-  }
-  module iostream {
-    header "iostream"
-    export ios
-    export streambuf
-    export istream
-    export ostream
-    export *
-  }
-  module istream {
-    header "istream"
-    // FIXME: should re-export ios, streambuf?
-    export *
-  }
-  module iterator {
-    header "iterator"
-    export *
-  }
-  module limits {
-    header "limits"
-    export *
-  }
-  module list {
-    header "list"
-    export initializer_list
-    export *
-  }
-  module locale {
-    header "locale"
-    export *
-  }
-  module map {
-    header "map"
-    export initializer_list
-    export *
-  }
-  module memory {
-    header "memory"
-    export *
-  }
-  module mutex {
-    header "mutex"
-    export *
-  }
-  module new {
-    header "new"
-    export *
-  }
-  module numeric {
-    header "numeric"
-    export *
-  }
-  module optional {
-    header "optional"
-    export *
-  }
-  module ostream {
-    header "ostream"
-    // FIXME: should re-export ios, streambuf?
-    export *
-  }
-  module queue {
-    header "queue"
-    export initializer_list
-    export *
-  }
-  module random {
-    header "random"
-    export initializer_list
-    export *
-  }
-  module ratio {
-    header "ratio"
-    export *
-  }
-  module regex {
-    header "regex"
-    export initializer_list
-    export *
-  }
-  module scoped_allocator {
-    header "scoped_allocator"
-    export *
-  }
-  module set {
-    header "set"
-    export initializer_list
-    export *
-  }
-  module sstream {
-    header "sstream"
-    // FIXME: should re-export istream, ostream, ios, streambuf, string?
-    export *
-  }
-  module stack {
-    header "stack"
-    export initializer_list
-    export *
-  }
-  module stdexcept {
-    header "stdexcept"
-    export *
-  }
-  module streambuf {
-    header "streambuf"
-    export *
-  }
-  module string {
-    header "string"
-    export initializer_list
-    export string_view
-    export __string
-    export *
-  }
-  module string_view {
-    header "string_view"
-    export initializer_list
-    export __string
-    export *
-  }
-  module strstream {
-    header "strstream"
-    export *
-  }
-  module system_error {
-    header "system_error"
-    export *
-  }
-  module thread {
-    header "thread"
-    export *
-  }
-  module tuple {
-    header "tuple"
-    export *
-  }
-  module type_traits {
-    header "type_traits"
-    export *
-  }
-  module typeindex {
-    header "typeindex"
-    export *
-  }
-  module typeinfo {
-    header "typeinfo"
-    export *
-  }
-  module unordered_map {
-    header "unordered_map"
-    export initializer_list
-    export *
-  }
-  module unordered_set {
-    header "unordered_set"
-    export initializer_list
-    export *
-  }
-  module utility {
-    header "utility"
-    export initializer_list
-    export *
-  }
-  module valarray {
-    header "valarray"
-    export initializer_list
-    export *
-  }
-  module variant {
-    header "variant"
-    export *
-  }
-  module vector {
-    header "vector"
-    export initializer_list
-    export *
-  }
-  module version {
-    header "version"
-    export *
-  }
-
-  // FIXME: These should be private.
-  module __bit_reference { header "__bit_reference" export * }
-  module __debug { header "__debug" export * }
-  module __errc { header "__errc" export * }
-  module __functional_base { header "__functional_base" export * }
-  module __hash_table { header "__hash_table" export * }
-  module __locale { header "__locale" export * }
-  module __mutex_base { header "__mutex_base" export * }
-  module __split_buffer { header "__split_buffer" export * }
-  module __sso_allocator { header "__sso_allocator" export * }
-  module __std_stream { header "__std_stream" export * }
-  module __string { header "__string" export * }
-  module __tree { header "__tree" export * }
-  module __tuple { header "__tuple" export * }
-  module __undef_macros { header "__undef_macros" export * }
-  module __node_handle { header "__node_handle" export * }
-
-  module experimental {
-    requires cplusplus11
-
-    module algorithm {
-      header "experimental/algorithm"
-      export *
-    }
-     module coroutine {
-      requires coroutines
-      header "experimental/coroutine"
-      export *
-    }
-    module deque {
-      header "experimental/deque"
-      export *
-    }
-    module filesystem {
-      header "experimental/filesystem"
-      export *
-    }
-    module forward_list {
-      header "experimental/forward_list"
-      export *
-    }
-    module functional {
-      header "experimental/functional"
-      export *
-    }
-    module iterator {
-      header "experimental/iterator"
-      export *
-    }
-    module list {
-      header "experimental/list"
-      export *
-    }
-    module map {
-      header "experimental/map"
-      export *
-    }
-    module memory_resource {
-      header "experimental/memory_resource"
-      export *
-    }
-    module propagate_const {
-      header "experimental/propagate_const"
-      export *
-    }
-    module regex {
-      header "experimental/regex"
-      export *
-    }
-    module simd {
-      header "experimental/simd"
-      export *
-    }
-    module set {
-      header "experimental/set"
-      export *
-    }
-    module span {
-      header "span"
-      export *
-    }
-    module string {
-      header "experimental/string"
-      export *
-    }
-    module type_traits {
-      header "experimental/type_traits"
-      export *
-    }
-    module unordered_map {
-      header "experimental/unordered_map"
-      export *
-    }
-    module unordered_set {
-      header "experimental/unordered_set"
-      export *
-    }
-    module utility {
-      header "experimental/utility"
-      export *
-    }
-    module vector {
-      header "experimental/vector"
-      export *
-    }
-    // FIXME these should be private
-    module __memory {
-      header "experimental/__memory"
-      export *
-    }
-  } // end experimental
-}
diff --git a/lib/libcxx/include/mutex b/lib/libcxx/include/mutex
deleted file mode 100644
index 6d2de2b460e..00000000000
--- a/lib/libcxx/include/mutex
+++ /dev/null
@@ -1,703 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- mutex ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_MUTEX
-#define _LIBCPP_MUTEX
-
-/*
-    mutex synopsis
-
-namespace std
-{
-
-class mutex
-{
-public:
-     constexpr mutex() noexcept;
-     ~mutex();
-
-    mutex(const mutex&) = delete;
-    mutex& operator=(const mutex&) = delete;
-
-    void lock();
-    bool try_lock();
-    void unlock();
-
-    typedef pthread_mutex_t* native_handle_type;
-    native_handle_type native_handle();
-};
-
-class recursive_mutex
-{
-public:
-     recursive_mutex();
-     ~recursive_mutex();
-
-    recursive_mutex(const recursive_mutex&) = delete;
-    recursive_mutex& operator=(const recursive_mutex&) = delete;
-
-    void lock();
-    bool try_lock() noexcept;
-    void unlock();
-
-    typedef pthread_mutex_t* native_handle_type;
-    native_handle_type native_handle();
-};
-
-class timed_mutex
-{
-public:
-     timed_mutex();
-     ~timed_mutex();
-
-    timed_mutex(const timed_mutex&) = delete;
-    timed_mutex& operator=(const timed_mutex&) = delete;
-
-    void lock();
-    bool try_lock();
-    template <class Rep, class Period>
-        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
-    template <class Clock, class Duration>
-        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
-    void unlock();
-};
-
-class recursive_timed_mutex
-{
-public:
-     recursive_timed_mutex();
-     ~recursive_timed_mutex();
-
-    recursive_timed_mutex(const recursive_timed_mutex&) = delete;
-    recursive_timed_mutex& operator=(const recursive_timed_mutex&) = delete;
-
-    void lock();
-    bool try_lock() noexcept;
-    template <class Rep, class Period>
-        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
-    template <class Clock, class Duration>
-        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
-    void unlock();
-};
-
-struct defer_lock_t {};
-struct try_to_lock_t {};
-struct adopt_lock_t {};
-
-inline constexpr defer_lock_t  defer_lock{};
-inline constexpr try_to_lock_t try_to_lock{};
-inline constexpr adopt_lock_t  adopt_lock{};
-
-template <class Mutex>
-class lock_guard
-{
-public:
-    typedef Mutex mutex_type;
-
-    explicit lock_guard(mutex_type& m);
-    lock_guard(mutex_type& m, adopt_lock_t);
-    ~lock_guard();
-
-    lock_guard(lock_guard const&) = delete;
-    lock_guard& operator=(lock_guard const&) = delete;
-};
-
-template <class... MutexTypes>
-class scoped_lock // C++17
-{
-public:
-    using mutex_type = Mutex;  // If MutexTypes... consists of the single type Mutex
-
-    explicit scoped_lock(MutexTypes&... m);
-    scoped_lock(adopt_lock_t, MutexTypes&... m);
-    ~scoped_lock();
-    scoped_lock(scoped_lock const&) = delete;
-    scoped_lock& operator=(scoped_lock const&) = delete;
-private:
-    tuple<MutexTypes&...> pm; // exposition only
-};
-
-template <class Mutex>
-class unique_lock
-{
-public:
-    typedef Mutex mutex_type;
-    unique_lock() noexcept;
-    explicit unique_lock(mutex_type& m);
-    unique_lock(mutex_type& m, defer_lock_t) noexcept;
-    unique_lock(mutex_type& m, try_to_lock_t);
-    unique_lock(mutex_type& m, adopt_lock_t);
-    template <class Clock, class Duration>
-        unique_lock(mutex_type& m, const chrono::time_point<Clock, Duration>& abs_time);
-    template <class Rep, class Period>
-        unique_lock(mutex_type& m, const chrono::duration<Rep, Period>& rel_time);
-    ~unique_lock();
-
-    unique_lock(unique_lock const&) = delete;
-    unique_lock& operator=(unique_lock const&) = delete;
-
-    unique_lock(unique_lock&& u) noexcept;
-    unique_lock& operator=(unique_lock&& u) noexcept;
-
-    void lock();
-    bool try_lock();
-
-    template <class Rep, class Period>
-        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
-    template <class Clock, class Duration>
-        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
-
-    void unlock();
-
-    void swap(unique_lock& u) noexcept;
-    mutex_type* release() noexcept;
-
-    bool owns_lock() const noexcept;
-    explicit operator bool () const noexcept;
-    mutex_type* mutex() const noexcept;
-};
-
-template <class Mutex>
-  void swap(unique_lock<Mutex>& x, unique_lock<Mutex>& y) noexcept;
-
-template <class L1, class L2, class... L3>
-  int try_lock(L1&, L2&, L3&...);
-template <class L1, class L2, class... L3>
-  void lock(L1&, L2&, L3&...);
-
-struct once_flag
-{
-    constexpr once_flag() noexcept;
-
-    once_flag(const once_flag&) = delete;
-    once_flag& operator=(const once_flag&) = delete;
-};
-
-template<class Callable, class ...Args>
-  void call_once(once_flag& flag, Callable&& func, Args&&... args);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__mutex_base>
-#include <functional>
-#include <memory>
-#ifndef _LIBCPP_CXX03_LANG
-#include <tuple>
-#endif
-#include <version>
-#include <__threading_support>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#ifndef _LIBCPP_HAS_NO_THREADS
-
-class _LIBCPP_TYPE_VIS recursive_mutex
-{
-    __libcpp_recursive_mutex_t __m_;
-
-public:
-     recursive_mutex();
-     ~recursive_mutex();
-
-private:
-    recursive_mutex(const recursive_mutex&); // = delete;
-    recursive_mutex& operator=(const recursive_mutex&); // = delete;
-
-public:
-    void lock();
-    bool try_lock() _NOEXCEPT;
-    void unlock()  _NOEXCEPT;
-
-    typedef __libcpp_recursive_mutex_t* native_handle_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    native_handle_type native_handle() {return &__m_;}
-};
-
-class _LIBCPP_TYPE_VIS timed_mutex
-{
-    mutex              __m_;
-    condition_variable __cv_;
-    bool               __locked_;
-public:
-     timed_mutex();
-     ~timed_mutex();
-
-private:
-    timed_mutex(const timed_mutex&); // = delete;
-    timed_mutex& operator=(const timed_mutex&); // = delete;
-
-public:
-    void lock();
-    bool try_lock() _NOEXCEPT;
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
-            {return try_lock_until(chrono::steady_clock::now() + __d);}
-    template <class _Clock, class _Duration>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
-    void unlock() _NOEXCEPT;
-};
-
-template <class _Clock, class _Duration>
-bool
-timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
-{
-    using namespace chrono;
-    unique_lock<mutex> __lk(__m_);
-    bool no_timeout = _Clock::now() < __t;
-    while (no_timeout && __locked_)
-        no_timeout = __cv_.wait_until(__lk, __t) == cv_status::no_timeout;
-    if (!__locked_)
-    {
-        __locked_ = true;
-        return true;
-    }
-    return false;
-}
-
-class _LIBCPP_TYPE_VIS recursive_timed_mutex
-{
-    mutex              __m_;
-    condition_variable __cv_;
-    size_t             __count_;
-    __libcpp_thread_id __id_;
-public:
-     recursive_timed_mutex();
-     ~recursive_timed_mutex();
-
-private:
-    recursive_timed_mutex(const recursive_timed_mutex&); // = delete;
-    recursive_timed_mutex& operator=(const recursive_timed_mutex&); // = delete;
-
-public:
-    void lock();
-    bool try_lock() _NOEXCEPT;
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        bool try_lock_for(const chrono::duration<_Rep, _Period>& __d)
-            {return try_lock_until(chrono::steady_clock::now() + __d);}
-    template <class _Clock, class _Duration>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        bool try_lock_until(const chrono::time_point<_Clock, _Duration>& __t);
-    void unlock() _NOEXCEPT;
-};
-
-template <class _Clock, class _Duration>
-bool
-recursive_timed_mutex::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
-{
-    using namespace chrono;
-    __libcpp_thread_id __id = __libcpp_thread_get_current_id();
-    unique_lock<mutex> lk(__m_);
-    if (__libcpp_thread_id_equal(__id, __id_))
-    {
-        if (__count_ == numeric_limits<size_t>::max())
-            return false;
-        ++__count_;
-        return true;
-    }
-    bool no_timeout = _Clock::now() < __t;
-    while (no_timeout && __count_ != 0)
-        no_timeout = __cv_.wait_until(lk, __t) == cv_status::no_timeout;
-    if (__count_ == 0)
-    {
-        __count_ = 1;
-        __id_ = __id;
-        return true;
-    }
-    return false;
-}
-
-template <class _L0, class _L1>
-int
-try_lock(_L0& __l0, _L1& __l1)
-{
-    unique_lock<_L0> __u0(__l0, try_to_lock);
-    if (__u0.owns_lock())
-    {
-        if (__l1.try_lock())
-        {
-            __u0.release();
-            return -1;
-        }
-        else
-            return 1;
-    }
-    return 0;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _L0, class _L1, class _L2, class... _L3>
-int
-try_lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3)
-{
-    int __r = 0;
-    unique_lock<_L0> __u0(__l0, try_to_lock);
-    if (__u0.owns_lock())
-    {
-        __r = try_lock(__l1, __l2, __l3...);
-        if (__r == -1)
-            __u0.release();
-        else
-            ++__r;
-    }
-    return __r;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _L0, class _L1>
-void
-lock(_L0& __l0, _L1& __l1)
-{
-    while (true)
-    {
-        {
-            unique_lock<_L0> __u0(__l0);
-            if (__l1.try_lock())
-            {
-                __u0.release();
-                break;
-            }
-        }
-        __libcpp_thread_yield();
-        {
-            unique_lock<_L1> __u1(__l1);
-            if (__l0.try_lock())
-            {
-                __u1.release();
-                break;
-            }
-        }
-        __libcpp_thread_yield();
-    }
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _L0, class _L1, class _L2, class ..._L3>
-void
-__lock_first(int __i, _L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
-{
-    while (true)
-    {
-        switch (__i)
-        {
-        case 0:
-            {
-                unique_lock<_L0> __u0(__l0);
-                __i = try_lock(__l1, __l2, __l3...);
-                if (__i == -1)
-                {
-                    __u0.release();
-                    return;
-                }
-            }
-            ++__i;
-            __libcpp_thread_yield();
-            break;
-        case 1:
-            {
-                unique_lock<_L1> __u1(__l1);
-                __i = try_lock(__l2, __l3..., __l0);
-                if (__i == -1)
-                {
-                    __u1.release();
-                    return;
-                }
-            }
-            if (__i == sizeof...(_L3) + 1)
-                __i = 0;
-            else
-                __i += 2;
-            __libcpp_thread_yield();
-            break;
-        default:
-            __lock_first(__i - 2, __l2, __l3..., __l0, __l1);
-            return;
-        }
-    }
-}
-
-template <class _L0, class _L1, class _L2, class ..._L3>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-lock(_L0& __l0, _L1& __l1, _L2& __l2, _L3& ...__l3)
-{
-    __lock_first(0, __l0, __l1, __l2, __l3...);
-}
-
-template <class _L0>
-inline _LIBCPP_INLINE_VISIBILITY
-void __unlock(_L0& __l0) {
-    __l0.unlock();
-}
-
-template <class _L0, class _L1>
-inline _LIBCPP_INLINE_VISIBILITY
-void __unlock(_L0& __l0, _L1& __l1) {
-    __l0.unlock();
-    __l1.unlock();
-}
-
-template <class _L0, class _L1, class _L2, class ..._L3>
-inline _LIBCPP_INLINE_VISIBILITY
-void __unlock(_L0& __l0, _L1& __l1, _L2& __l2, _L3&... __l3) {
-    __l0.unlock();
-    __l1.unlock();
-    _VSTD::__unlock(__l2, __l3...);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER > 14
-template <class ..._Mutexes>
-class _LIBCPP_TEMPLATE_VIS scoped_lock;
-
-template <>
-class _LIBCPP_TEMPLATE_VIS scoped_lock<> {
-public:
-    explicit scoped_lock() {}
-    ~scoped_lock() = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit scoped_lock(adopt_lock_t) {}
-
-    scoped_lock(scoped_lock const&) = delete;
-    scoped_lock& operator=(scoped_lock const&) = delete;
-};
-
-template <class _Mutex>
-class _LIBCPP_TEMPLATE_VIS _LIBCPP_THREAD_SAFETY_ANNOTATION(scoped_lockable) scoped_lock<_Mutex> {
-public:
-    typedef _Mutex  mutex_type;
-private:
-    mutex_type& __m_;
-public:
-    explicit scoped_lock(mutex_type & __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability(__m))
-        : __m_(__m) {__m_.lock();}
-
-    ~scoped_lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability()) {__m_.unlock();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit scoped_lock(adopt_lock_t, mutex_type& __m) _LIBCPP_THREAD_SAFETY_ANNOTATION(requires_capability(__m))
-        : __m_(__m) {}
-
-    scoped_lock(scoped_lock const&) = delete;
-    scoped_lock& operator=(scoped_lock const&) = delete;
-};
-
-template <class ..._MArgs>
-class _LIBCPP_TEMPLATE_VIS scoped_lock
-{
-    static_assert(sizeof...(_MArgs) > 1, "At least 2 lock types required");
-    typedef tuple<_MArgs&...> _MutexTuple;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit scoped_lock(_MArgs&... __margs)
-      : __t_(__margs...)
-    {
-        _VSTD::lock(__margs...);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    scoped_lock(adopt_lock_t, _MArgs&... __margs)
-        : __t_(__margs...)
-    {
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~scoped_lock() {
-        typedef typename __make_tuple_indices<sizeof...(_MArgs)>::type _Indices;
-        __unlock_unpack(_Indices{}, __t_);
-    }
-
-    scoped_lock(scoped_lock const&) = delete;
-    scoped_lock& operator=(scoped_lock const&) = delete;
-
-private:
-    template <size_t ..._Indx>
-    _LIBCPP_INLINE_VISIBILITY
-    static void __unlock_unpack(__tuple_indices<_Indx...>, _MutexTuple& __mt) {
-        _VSTD::__unlock(_VSTD::get<_Indx>(__mt)...);
-    }
-
-    _MutexTuple __t_;
-};
-
-#endif // _LIBCPP_STD_VER > 14
-#endif // !_LIBCPP_HAS_NO_THREADS
-
-struct _LIBCPP_TEMPLATE_VIS once_flag;
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Callable, class... _Args>
-_LIBCPP_INLINE_VISIBILITY
-void call_once(once_flag&, _Callable&&, _Args&&...);
-
-#else  // _LIBCPP_CXX03_LANG
-
-template<class _Callable>
-_LIBCPP_INLINE_VISIBILITY
-void call_once(once_flag&, _Callable&);
-
-template<class _Callable>
-_LIBCPP_INLINE_VISIBILITY
-void call_once(once_flag&, const _Callable&);
-
-#endif  // _LIBCPP_CXX03_LANG
-
-struct _LIBCPP_TEMPLATE_VIS once_flag
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR
-        once_flag() _NOEXCEPT : __state_(0) {}
-
-private:
-    once_flag(const once_flag&); // = delete;
-    once_flag& operator=(const once_flag&); // = delete;
-
-    unsigned long __state_;
-
-#ifndef _LIBCPP_CXX03_LANG
-    template<class _Callable, class... _Args>
-    friend
-    void call_once(once_flag&, _Callable&&, _Args&&...);
-#else  // _LIBCPP_CXX03_LANG
-    template<class _Callable>
-    friend
-    void call_once(once_flag&, _Callable&);
-
-    template<class _Callable>
-    friend
-    void call_once(once_flag&, const _Callable&);
-#endif  // _LIBCPP_CXX03_LANG
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Fp>
-class __call_once_param
-{
-    _Fp& __f_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __call_once_param(_Fp& __f) : __f_(__f) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()()
-    {
-        typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 1>::type _Index;
-        __execute(_Index());
-    }
-
-private:
-    template <size_t ..._Indices>
-    _LIBCPP_INLINE_VISIBILITY
-    void __execute(__tuple_indices<_Indices...>)
-    {
-        __invoke(_VSTD::get<0>(_VSTD::move(__f_)), _VSTD::get<_Indices>(_VSTD::move(__f_))...);
-    }
-};
-
-#else
-
-template <class _Fp>
-class __call_once_param
-{
-    _Fp& __f_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __call_once_param(_Fp& __f) : __f_(__f) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()()
-    {
-        __f_();
-    }
-};
-
-#endif
-
-template <class _Fp>
-void
-__call_once_proxy(void* __vp)
-{
-    __call_once_param<_Fp>* __p = static_cast<__call_once_param<_Fp>*>(__vp);
-    (*__p)();
-}
-
-_LIBCPP_FUNC_VIS void __call_once(volatile unsigned long&, void*, void(*)(void*));
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _Callable, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-call_once(once_flag& __flag, _Callable&& __func, _Args&&... __args)
-{
-    if (__libcpp_acquire_load(&__flag.__state_) != ~0ul)
-    {
-        typedef tuple<_Callable&&, _Args&&...> _Gp;
-        _Gp __f(_VSTD::forward<_Callable>(__func), _VSTD::forward<_Args>(__args)...);
-        __call_once_param<_Gp> __p(__f);
-        __call_once(__flag.__state_, &__p, &__call_once_proxy<_Gp>);
-    }
-}
-
-#else  // _LIBCPP_CXX03_LANG
-
-template<class _Callable>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-call_once(once_flag& __flag, _Callable& __func)
-{
-    if (__libcpp_acquire_load(&__flag.__state_) != ~0ul)
-    {
-        __call_once_param<_Callable> __p(__func);
-        __call_once(__flag.__state_, &__p, &__call_once_proxy<_Callable>);
-    }
-}
-
-template<class _Callable>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-call_once(once_flag& __flag, const _Callable& __func)
-{
-    if (__libcpp_acquire_load(&__flag.__state_) != ~0ul)
-    {
-        __call_once_param<const _Callable> __p(__func);
-        __call_once(__flag.__state_, &__p, &__call_once_proxy<const _Callable>);
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_MUTEX
diff --git a/lib/libcxx/include/new b/lib/libcxx/include/new
deleted file mode 100644
index 24ffcad5a6b..00000000000
--- a/lib/libcxx/include/new
+++ /dev/null
@@ -1,358 +0,0 @@
-// -*- C++ -*-
-//===----------------------------- new ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_NEW
-#define _LIBCPP_NEW
-
-/*
-    new synopsis
-
-namespace std
-{
-
-class bad_alloc
-    : public exception
-{
-public:
-    bad_alloc() noexcept;
-    bad_alloc(const bad_alloc&) noexcept;
-    bad_alloc& operator=(const bad_alloc&) noexcept;
-    virtual const char* what() const noexcept;
-};
-
-class bad_array_new_length : public bad_alloc // C++14
-{
-public:
-    bad_array_new_length() noexcept;
-};
-
-enum class align_val_t : size_t {}; // C++17
-struct nothrow_t {};
-extern const nothrow_t nothrow;
-typedef void (*new_handler)();
-new_handler set_new_handler(new_handler new_p) noexcept;
-new_handler get_new_handler() noexcept;
-
-// 21.6.4, pointer optimization barrier
-template <class T> constexpr T* launder(T* p) noexcept; // C++17
-}  // std
-
-void* operator new(std::size_t size);                                   // replaceable, nodiscard in C++2a
-void* operator new(std::size_t size, std::align_val_t alignment);       // replaceable, C++17, nodiscard in C++2a
-void* operator new(std::size_t size, const std::nothrow_t&) noexcept;   // replaceable, nodiscard in C++2a
-void* operator new(std::size_t size, std::align_val_t alignment,
-                   const std::nothrow_t&) noexcept;                     // replaceable, C++17, nodiscard in C++2a
-void  operator delete(void* ptr) noexcept;                              // replaceable
-void  operator delete(void* ptr, std::size_t size) noexcept;            // replaceable, C++14
-void  operator delete(void* ptr, std::align_val_t alignment) noexcept;  // replaceable, C++17
-void  operator delete(void* ptr, std::size_t size,
-                      std::align_val_t alignment) noexcept;             // replaceable, C++17
-void  operator delete(void* ptr, const std::nothrow_t&) noexcept;       // replaceable
-void  operator delete(void* ptr, std:align_val_t alignment,
-                      const std::nothrow_t&) noexcept;                  // replaceable, C++17
-
-void* operator new[](std::size_t size);                                 // replaceable, nodiscard in C++2a
-void* operator new[](std::size_t size,
-                     std::align_val_t alignment) noexcept;              // replaceable, C++17, nodiscard in C++2a
-void* operator new[](std::size_t size, const std::nothrow_t&) noexcept; // replaceable, nodiscard in C++2a
-void* operator new[](std::size_t size, std::align_val_t alignment,
-                     const std::nothrow_t&) noexcept;                   // replaceable, C++17, nodiscard in C++2a
-void  operator delete[](void* ptr) noexcept;                            // replaceable
-void  operator delete[](void* ptr, std::size_t size) noexcept;          // replaceable, C++14
-void  operator delete[](void* ptr,
-                        std::align_val_t alignment) noexcept;           // replaceable, C++17
-void  operator delete[](void* ptr, std::size_t size,
-                        std::align_val_t alignment) noexcept;           // replaceable, C++17
-void  operator delete[](void* ptr, const std::nothrow_t&) noexcept;     // replaceable
-void  operator delete[](void* ptr, std::align_val_t alignment,
-                        const std::nothrow_t&) noexcept;                // replaceable, C++17
-
-void* operator new  (std::size_t size, void* ptr) noexcept;             // nodiscard in C++2a
-void* operator new[](std::size_t size, void* ptr) noexcept;             // nodiscard in C++2a
-void  operator delete  (void* ptr, void*) noexcept;
-void  operator delete[](void* ptr, void*) noexcept;
-
-*/
-
-#include <__config>
-#include <exception>
-#include <type_traits>
-#include <cstddef>
-#include <version>
-#ifdef _LIBCPP_NO_EXCEPTIONS
-#include <cstdlib>
-#endif
-
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
-#include <new.h>
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#if !defined(__cpp_sized_deallocation) || __cpp_sized_deallocation  < 201309L
-#define _LIBCPP_HAS_NO_LANGUAGE_SIZED_DEALLOCATION
-#endif
-
-#if !defined(_LIBCPP_BUILDING_LIBRARY) && _LIBCPP_STD_VER < 14 && \
-    defined(_LIBCPP_HAS_NO_LANGUAGE_SIZED_DEALLOCATION)
-# define _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
-#endif
-
-#if defined(_LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION) || \
-    defined(_LIBCPP_HAS_NO_LANGUAGE_SIZED_DEALLOCATION)
-# define _LIBCPP_HAS_NO_SIZED_DEALLOCATION
-#endif
-
-#if !__has_builtin(__builtin_operator_new) || \
-   __has_builtin(__builtin_operator_new) < 201802L
-#define _LIBCPP_HAS_NO_BUILTIN_OVERLOADED_OPERATOR_NEW_DELETE
-#endif
-
-namespace std  // purposefully not using versioning namespace
-{
-
-#if !defined(_LIBCPP_ABI_MICROSOFT) || defined(_LIBCPP_NO_VCRUNTIME)
-struct _LIBCPP_TYPE_VIS nothrow_t {};
-extern _LIBCPP_FUNC_VIS const nothrow_t nothrow;
-
-class _LIBCPP_EXCEPTION_ABI bad_alloc
-    : public exception
-{
-public:
-    bad_alloc() _NOEXCEPT;
-    virtual ~bad_alloc() _NOEXCEPT;
-    virtual const char* what() const _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI bad_array_new_length
-    : public bad_alloc
-{
-public:
-    bad_array_new_length() _NOEXCEPT;
-    virtual ~bad_array_new_length() _NOEXCEPT;
-    virtual const char* what() const _NOEXCEPT;
-};
-
-typedef void (*new_handler)();
-_LIBCPP_FUNC_VIS new_handler set_new_handler(new_handler) _NOEXCEPT;
-_LIBCPP_FUNC_VIS new_handler get_new_handler() _NOEXCEPT;
-
-#endif // !_LIBCPP_ABI_MICROSOFT || _LIBCPP_NO_VCRUNTIME
-
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_bad_alloc();  // not in C++ spec
-
-#if !defined(_LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION) && \
-    !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME)
-#ifndef _LIBCPP_CXX03_LANG
-enum class _LIBCPP_ENUM_VIS align_val_t : size_t { };
-#else
-enum align_val_t { __zero = 0, __max = (size_t)-1 };
-#endif
-#endif
-
-}  // std
-
-#if defined(_LIBCPP_CXX03_LANG)
-#define _THROW_BAD_ALLOC throw(std::bad_alloc)
-#else
-#define _THROW_BAD_ALLOC
-#endif
-
-#if !defined(_LIBCPP_DEFER_NEW_TO_VCRUNTIME)
-
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz) _THROW_BAD_ALLOC;
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
-_LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p) _NOEXCEPT;
-_LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p, const std::nothrow_t&) _NOEXCEPT;
-#ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
-_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void  operator delete(void* __p, std::size_t __sz) _NOEXCEPT;
-#endif
-
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz) _THROW_BAD_ALLOC;
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
-_LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete[](void* __p) _NOEXCEPT;
-_LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete[](void* __p, const std::nothrow_t&) _NOEXCEPT;
-#ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
-_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void  operator delete[](void* __p, std::size_t __sz) _NOEXCEPT;
-#endif
-
-#ifndef _LIBCPP_HAS_NO_LIBRARY_ALIGNED_ALLOCATION
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new(std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
-_LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p, std::align_val_t) _NOEXCEPT;
-_LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete(void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
-#ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
-_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void  operator delete(void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
-#endif
-
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t) _THROW_BAD_ALLOC;
-_LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_OVERRIDABLE_FUNC_VIS void* operator new[](std::size_t __sz, std::align_val_t, const std::nothrow_t&) _NOEXCEPT _NOALIAS;
-_LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete[](void* __p, std::align_val_t) _NOEXCEPT;
-_LIBCPP_OVERRIDABLE_FUNC_VIS void  operator delete[](void* __p, std::align_val_t, const std::nothrow_t&) _NOEXCEPT;
-#ifndef _LIBCPP_HAS_NO_LIBRARY_SIZED_DEALLOCATION
-_LIBCPP_OVERRIDABLE_FUNC_VIS _LIBCPP_AVAILABILITY_SIZED_NEW_DELETE void  operator delete[](void* __p, std::size_t __sz, std::align_val_t) _NOEXCEPT;
-#endif
-#endif
-
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new  (std::size_t, void* __p) _NOEXCEPT {return __p;}
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY void* operator new[](std::size_t, void* __p) _NOEXCEPT {return __p;}
-inline _LIBCPP_INLINE_VISIBILITY void  operator delete  (void*, void*) _NOEXCEPT {}
-inline _LIBCPP_INLINE_VISIBILITY void  operator delete[](void*, void*) _NOEXCEPT {}
-
-#endif // !_LIBCPP_DEFER_NEW_TO_VCRUNTIME
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-_LIBCPP_CONSTEXPR inline _LIBCPP_INLINE_VISIBILITY bool __is_overaligned_for_new(size_t __align) _NOEXCEPT {
-#ifdef __STDCPP_DEFAULT_NEW_ALIGNMENT__
-  return __align > __STDCPP_DEFAULT_NEW_ALIGNMENT__;
-#else
-  return __align > alignment_of<max_align_t>::value;
-#endif
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void *__libcpp_allocate(size_t __size, size_t __align) {
-#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
-  if (__is_overaligned_for_new(__align)) {
-    const align_val_t __align_val = static_cast<align_val_t>(__align);
-# ifdef _LIBCPP_HAS_NO_BUILTIN_OVERLOADED_OPERATOR_NEW_DELETE
-    return ::operator new(__size, __align_val);
-# else
-    return __builtin_operator_new(__size, __align_val);
-# endif
-  }
-#else
-  ((void)__align);
-#endif
-#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
-  return ::operator new(__size);
-#else
-  return __builtin_operator_new(__size);
-#endif
-}
-
-struct _DeallocateCaller {
-  static inline _LIBCPP_INLINE_VISIBILITY
-  void __do_deallocate_handle_size_align(void *__ptr, size_t __size, size_t __align) {
-#if defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
-    ((void)__align);
-    return __do_deallocate_handle_size(__ptr, __size);
-#else
-    if (__is_overaligned_for_new(__align)) {
-      const align_val_t __align_val = static_cast<align_val_t>(__align);
-      return __do_deallocate_handle_size(__ptr, __size, __align_val);
-    } else {
-      return __do_deallocate_handle_size(__ptr, __size);
-    }
-#endif
-  }
-
-  static inline _LIBCPP_INLINE_VISIBILITY
-  void __do_deallocate_handle_align(void *__ptr, size_t __align) {
-#if defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
-    ((void)__align);
-    return __do_call(__ptr);
-#else
-    if (__is_overaligned_for_new(__align)) {
-      const align_val_t __align_val = static_cast<align_val_t>(__align);
-      return __do_call(__ptr, __align_val);
-    } else {
-      return __do_call(__ptr);
-    }
-#endif
-  }
-
- private:
-  static inline void __do_deallocate_handle_size(void *__ptr, size_t __size) {
-#ifdef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
-    ((void)__size);
-    return __do_call(__ptr);
-#else
-    return __do_call(__ptr, __size);
-#endif
-  }
-
-#ifndef _LIBCPP_HAS_NO_ALIGNED_ALLOCATION
-  static inline void __do_deallocate_handle_size(void *__ptr, size_t __size, align_val_t __align) {
-#ifdef _LIBCPP_HAS_NO_SIZED_DEALLOCATION
-    ((void)__size);
-    return __do_call(__ptr, __align);
-#else
-    return __do_call(__ptr, __size, __align);
-#endif
-  }
-#endif
-
-private:
-  template <class _A1, class _A2>
-  static inline void __do_call(void *__ptr, _A1 __a1, _A2 __a2) {
-#if defined(_LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE) || \
-    defined(_LIBCPP_HAS_NO_BUILTIN_OVERLOADED_OPERATOR_NEW_DELETE)
-    return ::operator delete(__ptr, __a1, __a2);
-#else
-    return __builtin_operator_delete(__ptr, __a1, __a2);
-#endif
-  }
-
-  template <class _A1>
-  static inline void __do_call(void *__ptr, _A1 __a1) {
-#if defined(_LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE) || \
-    defined(_LIBCPP_HAS_NO_BUILTIN_OVERLOADED_OPERATOR_NEW_DELETE)
-    return ::operator delete(__ptr, __a1);
-#else
-    return __builtin_operator_delete(__ptr, __a1);
-#endif
-  }
-
-  static inline void __do_call(void *__ptr) {
-#ifdef _LIBCPP_HAS_NO_BUILTIN_OPERATOR_NEW_DELETE
-    return ::operator delete(__ptr);
-#else
-    return __builtin_operator_delete(__ptr);
-#endif
-  }
-};
-
-inline _LIBCPP_INLINE_VISIBILITY void __libcpp_deallocate(void* __ptr, size_t __size, size_t __align) {
-  _DeallocateCaller::__do_deallocate_handle_size_align(__ptr, __size, __align);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY void __libcpp_deallocate_unsized(void* __ptr, size_t __align) {
-  _DeallocateCaller::__do_deallocate_handle_align(__ptr, __align);
-}
-
-template <class _Tp>
-_LIBCPP_NODISCARD_AFTER_CXX17 inline
-_LIBCPP_CONSTEXPR _Tp* __launder(_Tp* __p) _NOEXCEPT
-{
-    static_assert (!(is_function<_Tp>::value), "can't launder functions" );
-    static_assert (!(is_same<void, typename remove_cv<_Tp>::type>::value), "can't launder cv-void" );
-#ifdef _LIBCPP_COMPILER_HAS_BUILTIN_LAUNDER
-    return __builtin_launder(__p);
-#else
-    return __p;
-#endif
-}
-
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-_LIBCPP_NODISCARD_AFTER_CXX17 inline _LIBCPP_INLINE_VISIBILITY
-constexpr _Tp* launder(_Tp* __p) noexcept
-{
-    return _VSTD::__launder(__p);
-}
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_NEW
diff --git a/lib/libcxx/include/numeric b/lib/libcxx/include/numeric
deleted file mode 100644
index 4e68239d059..00000000000
--- a/lib/libcxx/include/numeric
+++ /dev/null
@@ -1,527 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- numeric ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_NUMERIC
-#define _LIBCPP_NUMERIC
-
-/*
-    numeric synopsis
-
-namespace std
-{
-
-template <class InputIterator, class T>
-    T
-    accumulate(InputIterator first, InputIterator last, T init);
-
-template <class InputIterator, class T, class BinaryOperation>
-    T
-    accumulate(InputIterator first, InputIterator last, T init, BinaryOperation binary_op);
-
-template<class InputIterator>
-    typename iterator_traits<InputIterator>::value_type
-    reduce(InputIterator first, InputIterator last);  // C++17
-
-template<class InputIterator, class T>
-    T
-    reduce(InputIterator first, InputIterator last, T init);  // C++17
-
-template<class InputIterator, class T, class BinaryOperation>
-    T
-    reduce(InputIterator first, InputIterator last, T init, BinaryOperation binary_op);  // C++17
-
-template <class InputIterator1, class InputIterator2, class T>
-    T
-    inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, T init);
-
-template <class InputIterator1, class InputIterator2, class T, class BinaryOperation1, class BinaryOperation2>
-    T
-    inner_product(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2,
-                  T init, BinaryOperation1 binary_op1, BinaryOperation2 binary_op2);
-
-
-template<class InputIterator1, class InputIterator2, class T>
-    T
-    transform_reduce(InputIterator1 first1, InputIterator1 last1,
-                     InputIterator2 first2, T init);  // C++17
-
-template<class InputIterator1, class InputIterator2, class T, class BinaryOperation1, class BinaryOperation2>
-    T
-    transform_reduce(InputIterator1 first1, InputIterator1 last1,
-                     InputIterator2 first2, T init,
-                     BinaryOperation1 binary_op1, BinaryOperation2 binary_op2);  // C++17
-
-template<class InputIterator, class T, class BinaryOperation, class UnaryOperation>
-    T
-    transform_reduce(InputIterator first, InputIterator last, T init,
-                     BinaryOperation binary_op, UnaryOperation unary_op);  // C++17
-
-template <class InputIterator, class OutputIterator>
-    OutputIterator
-    partial_sum(InputIterator first, InputIterator last, OutputIterator result);
-
-template <class InputIterator, class OutputIterator, class BinaryOperation>
-    OutputIterator
-    partial_sum(InputIterator first, InputIterator last, OutputIterator result, BinaryOperation binary_op);
-
-template<class InputIterator, class OutputIterator, class T>
-    OutputIterator
-    exclusive_scan(InputIterator first, InputIterator last,
-                   OutputIterator result, T init); // C++17
-
-template<class InputIterator, class OutputIterator, class T, class BinaryOperation>
-    OutputIterator
-    exclusive_scan(InputIterator first, InputIterator last,
-                   OutputIterator result, T init, BinaryOperation binary_op); // C++17
-
-template<class InputIterator, class OutputIterator>
-    OutputIterator
-    inclusive_scan(InputIterator first, InputIterator last, OutputIterator result);  // C++17
-
-template<class InputIterator, class OutputIterator, class BinaryOperation>
-    OutputIterator
-    inclusive_scan(InputIterator first, InputIterator last,
-                   OutputIterator result, BinaryOperation binary_op);  // C++17
-
-template<class InputIterator, class OutputIterator, class BinaryOperation, class T>
-    OutputIterator
-    inclusive_scan(InputIterator first, InputIterator last,
-                   OutputIterator result, BinaryOperation binary_op, T init);  // C++17
-
-template<class InputIterator, class OutputIterator, class T,
-         class BinaryOperation, class UnaryOperation>
-    OutputIterator
-    transform_exclusive_scan(InputIterator first, InputIterator last,
-                             OutputIterator result, T init,
-                             BinaryOperation binary_op, UnaryOperation unary_op);  // C++17
-
-template<class InputIterator, class OutputIterator,
-         class BinaryOperation, class UnaryOperation>
-    OutputIterator
-    transform_inclusive_scan(InputIterator first, InputIterator last,
-                             OutputIterator result,
-                             BinaryOperation binary_op, UnaryOperation unary_op);  // C++17
-
-template<class InputIterator, class OutputIterator,
-         class BinaryOperation, class UnaryOperation, class T>
-    OutputIterator
-    transform_inclusive_scan(InputIterator first, InputIterator last,
-                             OutputIterator result,
-                             BinaryOperation binary_op, UnaryOperation unary_op,
-                             T init);  // C++17
-
-template <class InputIterator, class OutputIterator>
-    OutputIterator
-    adjacent_difference(InputIterator first, InputIterator last, OutputIterator result);
-
-template <class InputIterator, class OutputIterator, class BinaryOperation>
-    OutputIterator
-    adjacent_difference(InputIterator first, InputIterator last, OutputIterator result, BinaryOperation binary_op);
-
-template <class ForwardIterator, class T>
-    void iota(ForwardIterator first, ForwardIterator last, T value);
-
-template <class M, class N>
-    constexpr common_type_t<M,N> gcd(M m, N n);    // C++17
-
-template <class M, class N>
-    constexpr common_type_t<M,N> lcm(M m, N n);    // C++17
-
-}  // std
-
-*/
-
-#include <__config>
-#include <iterator>
-#include <limits> // for numeric_limits
-#include <functional>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _InputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-accumulate(_InputIterator __first, _InputIterator __last, _Tp __init)
-{
-    for (; __first != __last; ++__first)
-        __init = __init + *__first;
-    return __init;
-}
-
-template <class _InputIterator, class _Tp, class _BinaryOperation>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-accumulate(_InputIterator __first, _InputIterator __last, _Tp __init, _BinaryOperation __binary_op)
-{
-    for (; __first != __last; ++__first)
-        __init = __binary_op(__init, *__first);
-    return __init;
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _InputIterator, class _Tp, class _BinaryOp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-reduce(_InputIterator __first, _InputIterator __last, _Tp __init, _BinaryOp __b)
-{
-    for (; __first != __last; ++__first)
-        __init = __b(__init, *__first);
-    return __init;
-}
-
-template <class _InputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-reduce(_InputIterator __first, _InputIterator __last, _Tp __init)
-{
-    return _VSTD::reduce(__first, __last, __init, _VSTD::plus<>());
-}
-
-template <class _InputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename iterator_traits<_InputIterator>::value_type
-reduce(_InputIterator __first, _InputIterator __last)
-{
-    return _VSTD::reduce(__first, __last,
-       typename iterator_traits<_InputIterator>::value_type{});
-}
-#endif
-
-template <class _InputIterator1, class _InputIterator2, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _Tp __init)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        __init = __init + *__first1 * *__first2;
-    return __init;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _Tp, class _BinaryOperation1, class _BinaryOperation2>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-inner_product(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2,
-              _Tp __init, _BinaryOperation1 __binary_op1, _BinaryOperation2 __binary_op2)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        __init = __binary_op1(__init, __binary_op2(*__first1, *__first2));
-    return __init;
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _InputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-transform_reduce(_InputIterator __first, _InputIterator __last,
-           _Tp __init,  _BinaryOp __b, _UnaryOp __u)
-{
-    for (; __first != __last; ++__first)
-        __init = __b(__init, __u(*__first));
-    return __init;
-}
-
-template <class _InputIterator1, class _InputIterator2,
-          class _Tp, class _BinaryOp1, class _BinaryOp2>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-transform_reduce(_InputIterator1 __first1, _InputIterator1 __last1,
-                 _InputIterator2 __first2, _Tp __init,  _BinaryOp1 __b1, _BinaryOp2 __b2)
-{
-    for (; __first1 != __last1; ++__first1, (void) ++__first2)
-        __init = __b1(__init, __b2(*__first1, *__first2));
-    return __init;
-}
-
-template <class _InputIterator1, class _InputIterator2, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp
-transform_reduce(_InputIterator1 __first1, _InputIterator1 __last1,
-                 _InputIterator2 __first2, _Tp __init)
-{
-    return _VSTD::transform_reduce(__first1, __last1, __first2, _VSTD::move(__init),
-                                   _VSTD::plus<>(), _VSTD::multiplies<>());
-}
-#endif
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    if (__first != __last)
-    {
-        typename iterator_traits<_InputIterator>::value_type __t(*__first);
-        *__result = __t;
-        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
-        {
-            __t = __t + *__first;
-            *__result = __t;
-        }
-    }
-    return __result;
-}
-
-template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-partial_sum(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
-              _BinaryOperation __binary_op)
-{
-    if (__first != __last)
-    {
-        typename iterator_traits<_InputIterator>::value_type __t(*__first);
-        *__result = __t;
-        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
-        {
-            __t = __binary_op(__t, *__first);
-            *__result = __t;
-        }
-    }
-    return __result;
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-exclusive_scan(_InputIterator __first, _InputIterator __last,
-               _OutputIterator __result, _Tp __init, _BinaryOp __b)
-{
-    if (__first != __last)
-    {
-        _Tp __saved = __init;
-        do
-        {
-            __init = __b(__init, *__first);
-            *__result = __saved;
-            __saved = __init;
-            ++__result;
-        } while (++__first != __last);
-    }
-    return __result;
-}
-
-template <class _InputIterator, class _OutputIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-exclusive_scan(_InputIterator __first, _InputIterator __last,
-               _OutputIterator __result, _Tp __init)
-{
-    return _VSTD::exclusive_scan(__first, __last, __result, __init, _VSTD::plus<>());
-}
-
-template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp>
-_OutputIterator inclusive_scan(_InputIterator __first, _InputIterator __last,
-                               _OutputIterator __result, _BinaryOp __b,  _Tp __init)
-{
-    for (; __first != __last; ++__first, (void) ++__result) {
-        __init = __b(__init, *__first);
-        *__result = __init;
-        }
-    return __result;
-}
-
-template <class _InputIterator, class _OutputIterator, class _BinaryOp>
-_OutputIterator inclusive_scan(_InputIterator __first, _InputIterator __last,
-                               _OutputIterator __result, _BinaryOp __b)
-{
-    if (__first != __last) {
-        typename std::iterator_traits<_InputIterator>::value_type __init = *__first;
-        *__result++ = __init;
-        if (++__first != __last)
-            return _VSTD::inclusive_scan(__first, __last, __result, __b, __init);
-        }
-
-    return __result;
-}
-
-template <class _InputIterator, class _OutputIterator>
-_OutputIterator inclusive_scan(_InputIterator __first, _InputIterator __last,
-                               _OutputIterator __result)
-{
-    return _VSTD::inclusive_scan(__first, __last, __result, std::plus<>());
-}
-
-template <class _InputIterator, class _OutputIterator, class _Tp,
-          class _BinaryOp, class _UnaryOp>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-transform_exclusive_scan(_InputIterator __first, _InputIterator __last,
-                           _OutputIterator __result, _Tp __init,
-                           _BinaryOp __b, _UnaryOp __u)
-{
-    if (__first != __last)
-    {
-        _Tp __saved = __init;
-        do
-        {
-            __init = __b(__init, __u(*__first));
-            *__result = __saved;
-            __saved = __init;
-            ++__result;
-        } while (++__first != __last);
-    }
-    return __result;
-}
-
-template <class _InputIterator, class _OutputIterator, class _Tp, class _BinaryOp, class _UnaryOp>
-_OutputIterator transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
-                           _OutputIterator __result, _BinaryOp __b, _UnaryOp __u, _Tp __init)
-{
-    for (; __first != __last; ++__first, (void) ++__result) {
-        __init = __b(__init, __u(*__first));
-        *__result = __init;
-        }
-
-    return __result;
-}
-
-template <class _InputIterator, class _OutputIterator, class _BinaryOp, class _UnaryOp>
-_OutputIterator transform_inclusive_scan(_InputIterator __first, _InputIterator __last,
-                               _OutputIterator __result, _BinaryOp __b, _UnaryOp __u)
-{
-    if (__first != __last) {
-        typename std::iterator_traits<_InputIterator>::value_type __init = __u(*__first);
-        *__result++ = __init;
-        if (++__first != __last)
-            return _VSTD::transform_inclusive_scan(__first, __last, __result, __b, __u, __init);
-        }
-
-    return __result;
-}
-#endif
-
-template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
-{
-    if (__first != __last)
-    {
-        typename iterator_traits<_InputIterator>::value_type __t1(*__first);
-        *__result = __t1;
-        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
-        {
-            typename iterator_traits<_InputIterator>::value_type __t2(*__first);
-            *__result = __t2 - __t1;
-            __t1 = _VSTD::move(__t2);
-        }
-    }
-    return __result;
-}
-
-template <class _InputIterator, class _OutputIterator, class _BinaryOperation>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-adjacent_difference(_InputIterator __first, _InputIterator __last, _OutputIterator __result,
-                      _BinaryOperation __binary_op)
-{
-    if (__first != __last)
-    {
-        typename iterator_traits<_InputIterator>::value_type __t1(*__first);
-        *__result = __t1;
-        for (++__first, (void) ++__result; __first != __last; ++__first, (void) ++__result)
-        {
-            typename iterator_traits<_InputIterator>::value_type __t2(*__first);
-            *__result = __binary_op(__t2, __t1);
-            __t1 = _VSTD::move(__t2);
-        }
-    }
-    return __result;
-}
-
-template <class _ForwardIterator, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-iota(_ForwardIterator __first, _ForwardIterator __last, _Tp __value_)
-{
-    for (; __first != __last; ++__first, (void) ++__value_)
-        *__first = __value_;
-}
-
-
-#if _LIBCPP_STD_VER > 14
-template <typename _Result, typename _Source, bool _IsSigned = is_signed<_Source>::value> struct __abs;
-
-template <typename _Result, typename _Source>
-struct __abs<_Result, _Source, true> {
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    _Result operator()(_Source __t) const noexcept
-    {
-    if (__t >= 0) return __t;
-    if (__t == numeric_limits<_Source>::min()) return -static_cast<_Result>(__t);
-    return -__t;
-    }
-};
-
-template <typename _Result, typename _Source>
-struct __abs<_Result, _Source, false> {
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    _Result operator()(_Source __t) const noexcept { return __t; }
-};
-
-
-template<class _Tp>
-_LIBCPP_CONSTEXPR _LIBCPP_HIDDEN
-_Tp __gcd(_Tp __m, _Tp __n)
-{
-    static_assert((!is_signed<_Tp>::value), "");
-    return __n == 0 ? __m : _VSTD::__gcd<_Tp>(__n, __m % __n);
-}
-
-
-template<class _Tp, class _Up>
-_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-common_type_t<_Tp,_Up>
-gcd(_Tp __m, _Up __n)
-{
-    static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to gcd must be integer types");
-    static_assert((!is_same<typename remove_cv<_Tp>::type, bool>::value), "First argument to gcd cannot be bool" );
-    static_assert((!is_same<typename remove_cv<_Up>::type, bool>::value), "Second argument to gcd cannot be bool" );
-    using _Rp = common_type_t<_Tp,_Up>;
-    using _Wp = make_unsigned_t<_Rp>;
-    return static_cast<_Rp>(_VSTD::__gcd(
-        static_cast<_Wp>(__abs<_Rp, _Tp>()(__m)),
-        static_cast<_Wp>(__abs<_Rp, _Up>()(__n))));
-}
-
-template<class _Tp, class _Up>
-_LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-common_type_t<_Tp,_Up>
-lcm(_Tp __m, _Up __n)
-{
-    static_assert((is_integral<_Tp>::value && is_integral<_Up>::value), "Arguments to lcm must be integer types");
-    static_assert((!is_same<typename remove_cv<_Tp>::type, bool>::value), "First argument to lcm cannot be bool" );
-    static_assert((!is_same<typename remove_cv<_Up>::type, bool>::value), "Second argument to lcm cannot be bool" );
-    if (__m == 0 || __n == 0)
-        return 0;
-
-    using _Rp = common_type_t<_Tp,_Up>;
-    _Rp __val1 = __abs<_Rp, _Tp>()(__m) / _VSTD::gcd(__m, __n);
-    _Rp __val2 = __abs<_Rp, _Up>()(__n);
-    _LIBCPP_ASSERT((numeric_limits<_Rp>::max() / __val1 > __val2), "Overflow in lcm");
-    return __val1 * __val2;
-}
-
-#endif /* _LIBCPP_STD_VER > 14 */
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_NUMERIC
diff --git a/lib/libcxx/include/optional b/lib/libcxx/include/optional
deleted file mode 100644
index 70422068e28..00000000000
--- a/lib/libcxx/include/optional
+++ /dev/null
@@ -1,1414 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- optional ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_OPTIONAL
-#define _LIBCPP_OPTIONAL
-
-/*
-    optional synopsis
-
-// C++1z
-
-namespace std {
-  // 23.6.3, optional for object types
-  template <class T> class optional;
-
-  // 23.6.4, no-value state indicator
-  struct nullopt_t{see below };
-  inline constexpr nullopt_t nullopt(unspecified );
-
-  // 23.6.5, class bad_optional_access
-  class bad_optional_access;
-
-  // 23.6.6, relational operators
-  template <class T, class U>
-  constexpr bool operator==(const optional<T>&, const optional<U>&);
-  template <class T, class U>
-  constexpr bool operator!=(const optional<T>&, const optional<U>&);
-  template <class T, class U>
-  constexpr bool operator<(const optional<T>&, const optional<U>&);
-  template <class T, class U>
-  constexpr bool operator>(const optional<T>&, const optional<U>&);
-  template <class T, class U>
-  constexpr bool operator<=(const optional<T>&, const optional<U>&);
-  template <class T, class U>
-  constexpr bool operator>=(const optional<T>&, const optional<U>&);
-
-  // 23.6.7 comparison with nullopt
-  template <class T> constexpr bool operator==(const optional<T>&, nullopt_t) noexcept;
-  template <class T> constexpr bool operator==(nullopt_t, const optional<T>&) noexcept;
-  template <class T> constexpr bool operator!=(const optional<T>&, nullopt_t) noexcept;
-  template <class T> constexpr bool operator!=(nullopt_t, const optional<T>&) noexcept;
-  template <class T> constexpr bool operator<(const optional<T>&, nullopt_t) noexcept;
-  template <class T> constexpr bool operator<(nullopt_t, const optional<T>&) noexcept;
-  template <class T> constexpr bool operator<=(const optional<T>&, nullopt_t) noexcept;
-  template <class T> constexpr bool operator<=(nullopt_t, const optional<T>&) noexcept;
-  template <class T> constexpr bool operator>(const optional<T>&, nullopt_t) noexcept;
-  template <class T> constexpr bool operator>(nullopt_t, const optional<T>&) noexcept;
-  template <class T> constexpr bool operator>=(const optional<T>&, nullopt_t) noexcept;
-  template <class T> constexpr bool operator>=(nullopt_t, const optional<T>&) noexcept;
-
-  // 23.6.8, comparison with T
-  template <class T, class U> constexpr bool operator==(const optional<T>&, const U&);
-  template <class T, class U> constexpr bool operator==(const T&, const optional<U>&);
-  template <class T, class U> constexpr bool operator!=(const optional<T>&, const U&);
-  template <class T, class U> constexpr bool operator!=(const T&, const optional<U>&);
-  template <class T, class U> constexpr bool operator<(const optional<T>&, const U&);
-  template <class T, class U> constexpr bool operator<(const T&, const optional<U>&);
-  template <class T, class U> constexpr bool operator<=(const optional<T>&, const U&);
-  template <class T, class U> constexpr bool operator<=(const T&, const optional<U>&);
-  template <class T, class U> constexpr bool operator>(const optional<T>&, const U&);
-  template <class T, class U> constexpr bool operator>(const T&, const optional<U>&);
-  template <class T, class U> constexpr bool operator>=(const optional<T>&, const U&);
-  template <class T, class U> constexpr bool operator>=(const T&, const optional<U>&);
-
-  // 23.6.9, specialized algorithms
-  template <class T> void swap(optional<T>&, optional<T>&) noexcept(see below );
-  template <class T> constexpr optional<see below > make_optional(T&&);
-  template <class T, class... Args>
-    constexpr optional<T> make_optional(Args&&... args);
-  template <class T, class U, class... Args>
-    constexpr optional<T> make_optional(initializer_list<U> il, Args&&... args);
-
-  // 23.6.10, hash support
-  template <class T> struct hash;
-  template <class T> struct hash<optional<T>>;
-
-  template <class T> class optional {
-  public:
-    using value_type = T;
-
-    // 23.6.3.1, constructors
-    constexpr optional() noexcept;
-    constexpr optional(nullopt_t) noexcept;
-    optional(const optional &);
-    optional(optional &&) noexcept(see below);
-    template <class... Args> constexpr explicit optional(in_place_t, Args &&...);
-    template <class U, class... Args>
-      constexpr explicit optional(in_place_t, initializer_list<U>, Args &&...);
-    template <class U = T>
-      constexpr EXPLICIT optional(U &&);
-    template <class U>
-      constexpr EXPLICIT optional(const optional<U> &);
-    template <class U>
-      constexpr EXPLICIT optional(optional<U> &&);
-
-    // 23.6.3.2, destructor
-    ~optional();
-
-    // 23.6.3.3, assignment
-    optional &operator=(nullopt_t) noexcept;
-    optional &operator=(const optional &);                // constexpr in C++20
-    optional &operator=(optional &&) noexcept(see below); // constexpr in C++20
-    template <class U = T> optional &operator=(U &&);
-    template <class U> optional &operator=(const optional<U> &);
-    template <class U> optional &operator=(optional<U> &&);
-    template <class... Args> T& emplace(Args &&...);
-    template <class U, class... Args>
-      T& emplace(initializer_list<U>, Args &&...);
-
-    // 23.6.3.4, swap
-    void swap(optional &) noexcept(see below );
-
-    // 23.6.3.5, observers
-    constexpr T const *operator->() const;
-    constexpr T *operator->();
-    constexpr T const &operator*() const &;
-    constexpr T &operator*() &;
-    constexpr T &&operator*() &&;
-    constexpr const T &&operator*() const &&;
-    constexpr explicit operator bool() const noexcept;
-    constexpr bool has_value() const noexcept;
-    constexpr T const &value() const &;
-    constexpr T &value() &;
-    constexpr T &&value() &&;
-    constexpr const T &&value() const &&;
-    template <class U> constexpr T value_or(U &&) const &;
-    template <class U> constexpr T value_or(U &&) &&;
-
-    // 23.6.3.6, modifiers
-    void reset() noexcept;
-
-  private:
-    T *val; // exposition only
-  };
-
-template<class T>
-  optional(T) -> optional<T>;
-
-} // namespace std
-
-*/
-
-#include <__config>
-#include <__debug>
-#include <__functional_base>
-#include <functional>
-#include <initializer_list>
-#include <new>
-#include <stdexcept>
-#include <type_traits>
-#include <utility>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-namespace std  // purposefully not using versioning namespace
-{
-
-class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS bad_optional_access
-    : public exception
-{
-public:
-    // Get the key function ~bad_optional_access() into the dylib
-    virtual ~bad_optional_access() _NOEXCEPT;
-    virtual const char* what() const _NOEXCEPT;
-};
-
-}  // std
-
-#if _LIBCPP_STD_VER > 14
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-_LIBCPP_NORETURN
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
-void __throw_bad_optional_access() {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        throw bad_optional_access();
-#else
-        _VSTD::abort();
-#endif
-}
-
-struct nullopt_t
-{
-    struct __secret_tag { _LIBCPP_INLINE_VISIBILITY explicit __secret_tag() = default; };
-    _LIBCPP_INLINE_VISIBILITY constexpr explicit nullopt_t(__secret_tag, __secret_tag) noexcept {}
-};
-
-_LIBCPP_INLINE_VAR constexpr nullopt_t nullopt{nullopt_t::__secret_tag{}, nullopt_t::__secret_tag{}};
-
-template <class _Tp, bool = is_trivially_destructible<_Tp>::value>
-struct __optional_destruct_base;
-
-template <class _Tp>
-struct __optional_destruct_base<_Tp, false>
-{
-    typedef _Tp value_type;
-    static_assert(is_object_v<value_type>,
-        "instantiation of optional with a non-object type is undefined behavior");
-    union
-    {
-        char __null_state_;
-        value_type __val_;
-    };
-    bool __engaged_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~__optional_destruct_base()
-    {
-        if (__engaged_)
-            __val_.~value_type();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr __optional_destruct_base() noexcept
-        :  __null_state_(),
-           __engaged_(false) {}
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit __optional_destruct_base(in_place_t, _Args&&... __args)
-        :  __val_(_VSTD::forward<_Args>(__args)...),
-           __engaged_(true) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() noexcept
-    {
-        if (__engaged_)
-        {
-            __val_.~value_type();
-            __engaged_ = false;
-        }
-    }
-};
-
-template <class _Tp>
-struct __optional_destruct_base<_Tp, true>
-{
-    typedef _Tp value_type;
-    static_assert(is_object_v<value_type>,
-        "instantiation of optional with a non-object type is undefined behavior");
-    union
-    {
-        char __null_state_;
-        value_type __val_;
-    };
-    bool __engaged_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr __optional_destruct_base() noexcept
-        :  __null_state_(),
-           __engaged_(false) {}
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit __optional_destruct_base(in_place_t, _Args&&... __args)
-        :  __val_(_VSTD::forward<_Args>(__args)...),
-           __engaged_(true) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() noexcept
-    {
-        if (__engaged_)
-        {
-            __engaged_ = false;
-        }
-    }
-};
-
-template <class _Tp, bool = is_reference<_Tp>::value>
-struct __optional_storage_base : __optional_destruct_base<_Tp>
-{
-    using __base = __optional_destruct_base<_Tp>;
-    using value_type = _Tp;
-    using __base::__base;
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr bool has_value() const noexcept
-    {
-        return this->__engaged_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr value_type& __get() & noexcept
-    {
-        return this->__val_;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr const value_type& __get() const& noexcept
-    {
-        return this->__val_;
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr value_type&& __get() && noexcept
-    {
-        return _VSTD::move(this->__val_);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr const value_type&& __get() const&& noexcept
-    {
-        return _VSTD::move(this->__val_);
-    }
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    void __construct(_Args&&... __args)
-    {
-        _LIBCPP_ASSERT(!has_value(), "__construct called for engaged __optional_storage");
-        ::new((void*)_VSTD::addressof(this->__val_)) value_type(_VSTD::forward<_Args>(__args)...);
-        this->__engaged_ = true;
-    }
-
-    template <class _That>
-    _LIBCPP_INLINE_VISIBILITY
-    void __construct_from(_That&& __opt)
-    {
-        if (__opt.has_value())
-            __construct(_VSTD::forward<_That>(__opt).__get());
-    }
-
-    template <class _That>
-    _LIBCPP_INLINE_VISIBILITY
-    void __assign_from(_That&& __opt)
-    {
-        if (this->__engaged_ == __opt.has_value())
-        {
-            if (this->__engaged_)
-                this->__val_ = _VSTD::forward<_That>(__opt).__get();
-        }
-        else
-        {
-            if (this->__engaged_)
-                this->reset();
-            else
-                __construct(_VSTD::forward<_That>(__opt).__get());
-        }
-    }
-};
-
-// optional<T&> is currently required ill-formed, however it may to be in the
-// future. For this reason it has already been implemented to ensure we can
-// make the change in an ABI compatible manner.
-template <class _Tp>
-struct __optional_storage_base<_Tp, true>
-{
-    using value_type = _Tp;
-    using __raw_type = remove_reference_t<_Tp>;
-    __raw_type* __value_;
-
-    template <class _Up>
-    static constexpr bool __can_bind_reference() {
-        using _RawUp = typename remove_reference<_Up>::type;
-        using _UpPtr = _RawUp*;
-        using _RawTp = typename remove_reference<_Tp>::type;
-        using _TpPtr = _RawTp*;
-        using _CheckLValueArg = integral_constant<bool,
-            (is_lvalue_reference<_Up>::value && is_convertible<_UpPtr, _TpPtr>::value)
-        ||  is_same<_RawUp, reference_wrapper<_RawTp>>::value
-        ||  is_same<_RawUp, reference_wrapper<typename remove_const<_RawTp>::type>>::value
-        >;
-        return (is_lvalue_reference<_Tp>::value && _CheckLValueArg::value)
-            || (is_rvalue_reference<_Tp>::value && !is_lvalue_reference<_Up>::value &&
-                is_convertible<_UpPtr, _TpPtr>::value);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr __optional_storage_base() noexcept
-        :  __value_(nullptr) {}
-
-    template <class _UArg>
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit __optional_storage_base(in_place_t, _UArg&& __uarg)
-        :  __value_(_VSTD::addressof(__uarg))
-    {
-      static_assert(__can_bind_reference<_UArg>(),
-        "Attempted to construct a reference element in tuple from a "
-        "possible temporary");
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() noexcept { __value_ = nullptr; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr bool has_value() const noexcept
-      { return __value_ != nullptr; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr value_type& __get() const& noexcept
-      { return *__value_; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr value_type&& __get() const&& noexcept
-      { return _VSTD::forward<value_type>(*__value_); }
-
-    template <class _UArg>
-    _LIBCPP_INLINE_VISIBILITY
-    void __construct(_UArg&& __val)
-    {
-        _LIBCPP_ASSERT(!has_value(), "__construct called for engaged __optional_storage");
-        static_assert(__can_bind_reference<_UArg>(),
-            "Attempted to construct a reference element in tuple from a "
-            "possible temporary");
-        __value_ = _VSTD::addressof(__val);
-    }
-
-    template <class _That>
-    _LIBCPP_INLINE_VISIBILITY
-    void __construct_from(_That&& __opt)
-    {
-        if (__opt.has_value())
-            __construct(_VSTD::forward<_That>(__opt).__get());
-    }
-
-    template <class _That>
-    _LIBCPP_INLINE_VISIBILITY
-    void __assign_from(_That&& __opt)
-    {
-        if (has_value() == __opt.has_value())
-        {
-            if (has_value())
-                *__value_ = _VSTD::forward<_That>(__opt).__get();
-        }
-        else
-        {
-            if (has_value())
-                reset();
-            else
-                __construct(_VSTD::forward<_That>(__opt).__get());
-        }
-    }
-};
-
-template <class _Tp, bool = is_trivially_copy_constructible<_Tp>::value>
-struct __optional_copy_base : __optional_storage_base<_Tp>
-{
-    using __optional_storage_base<_Tp>::__optional_storage_base;
-};
-
-template <class _Tp>
-struct __optional_copy_base<_Tp, false> : __optional_storage_base<_Tp>
-{
-    using __optional_storage_base<_Tp>::__optional_storage_base;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_base() = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_base(const __optional_copy_base& __opt)
-    {
-        this->__construct_from(__opt);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_base(__optional_copy_base&&) = default;
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_base& operator=(const __optional_copy_base&) = default;
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_base& operator=(__optional_copy_base&&) = default;
-};
-
-template <class _Tp, bool = is_trivially_move_constructible<_Tp>::value>
-struct __optional_move_base : __optional_copy_base<_Tp>
-{
-    using __optional_copy_base<_Tp>::__optional_copy_base;
-};
-
-template <class _Tp>
-struct __optional_move_base<_Tp, false> : __optional_copy_base<_Tp>
-{
-    using value_type = _Tp;
-    using __optional_copy_base<_Tp>::__optional_copy_base;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_base() = default;
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_base(const __optional_move_base&) = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_base(__optional_move_base&& __opt)
-        noexcept(is_nothrow_move_constructible_v<value_type>)
-    {
-        this->__construct_from(_VSTD::move(__opt));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_base& operator=(const __optional_move_base&) = default;
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_base& operator=(__optional_move_base&&) = default;
-};
-
-template <class _Tp, bool =
-    is_trivially_destructible<_Tp>::value &&
-    is_trivially_copy_constructible<_Tp>::value &&
-    is_trivially_copy_assignable<_Tp>::value>
-struct __optional_copy_assign_base : __optional_move_base<_Tp>
-{
-    using __optional_move_base<_Tp>::__optional_move_base;
-};
-
-template <class _Tp>
-struct __optional_copy_assign_base<_Tp, false> : __optional_move_base<_Tp>
-{
-    using __optional_move_base<_Tp>::__optional_move_base;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_assign_base() = default;
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_assign_base(const __optional_copy_assign_base&) = default;
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_assign_base(__optional_copy_assign_base&&) = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_assign_base& operator=(const __optional_copy_assign_base& __opt)
-    {
-        this->__assign_from(__opt);
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_copy_assign_base& operator=(__optional_copy_assign_base&&) = default;
-};
-
-template <class _Tp, bool =
-    is_trivially_destructible<_Tp>::value &&
-    is_trivially_move_constructible<_Tp>::value &&
-    is_trivially_move_assignable<_Tp>::value>
-struct __optional_move_assign_base : __optional_copy_assign_base<_Tp>
-{
-    using __optional_copy_assign_base<_Tp>::__optional_copy_assign_base;
-};
-
-template <class _Tp>
-struct __optional_move_assign_base<_Tp, false> : __optional_copy_assign_base<_Tp>
-{
-    using value_type = _Tp;
-    using __optional_copy_assign_base<_Tp>::__optional_copy_assign_base;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_assign_base() = default;
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_assign_base(const __optional_move_assign_base& __opt) = default;
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_assign_base(__optional_move_assign_base&&) = default;
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_assign_base& operator=(const __optional_move_assign_base&) = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __optional_move_assign_base& operator=(__optional_move_assign_base&& __opt)
-        noexcept(is_nothrow_move_assignable_v<value_type> &&
-                 is_nothrow_move_constructible_v<value_type>)
-    {
-        this->__assign_from(_VSTD::move(__opt));
-        return *this;
-    }
-};
-
-template <class _Tp>
-using __optional_sfinae_ctor_base_t = __sfinae_ctor_base<
-    is_copy_constructible<_Tp>::value,
-    is_move_constructible<_Tp>::value
->;
-
-template <class _Tp>
-using __optional_sfinae_assign_base_t = __sfinae_assign_base<
-    (is_copy_constructible<_Tp>::value && is_copy_assignable<_Tp>::value),
-    (is_move_constructible<_Tp>::value && is_move_assignable<_Tp>::value)
->;
-
-template <class _Tp>
-class optional
-    : private __optional_move_assign_base<_Tp>
-    , private __optional_sfinae_ctor_base_t<_Tp>
-    , private __optional_sfinae_assign_base_t<_Tp>
-{
-    using __base = __optional_move_assign_base<_Tp>;
-public:
-    using value_type = _Tp;
-
-private:
-     // Disable the reference extension using this static assert.
-    static_assert(!is_same_v<value_type, in_place_t>,
-        "instantiation of optional with in_place_t is ill-formed");
-    static_assert(!is_same_v<__uncvref_t<value_type>, nullopt_t>,
-        "instantiation of optional with nullopt_t is ill-formed");
-    static_assert(!is_reference_v<value_type>,
-        "instantiation of optional with a reference type is ill-formed");
-    static_assert(is_destructible_v<value_type>,
-        "instantiation of optional with a non-destructible type is ill-formed");
-
-    // LWG2756: conditionally explicit conversion from _Up
-    struct _CheckOptionalArgsConstructor {
-      template <class _Up>
-      static constexpr bool __enable_implicit() {
-          return is_constructible_v<_Tp, _Up&&> &&
-                 is_convertible_v<_Up&&, _Tp>;
-      }
-
-      template <class _Up>
-      static constexpr bool __enable_explicit() {
-          return is_constructible_v<_Tp, _Up&&> &&
-                 !is_convertible_v<_Up&&, _Tp>;
-      }
-    };
-    template <class _Up>
-    using _CheckOptionalArgsCtor = conditional_t<
-        !is_same_v<__uncvref_t<_Up>, in_place_t> &&
-        !is_same_v<__uncvref_t<_Up>, optional>,
-        _CheckOptionalArgsConstructor,
-        __check_tuple_constructor_fail
-    >;
-    template <class _QualUp>
-    struct _CheckOptionalLikeConstructor {
-      template <class _Up, class _Opt = optional<_Up>>
-      using __check_constructible_from_opt = __lazy_or<
-          is_constructible<_Tp, _Opt&>,
-          is_constructible<_Tp, _Opt const&>,
-          is_constructible<_Tp, _Opt&&>,
-          is_constructible<_Tp, _Opt const&&>,
-          is_convertible<_Opt&, _Tp>,
-          is_convertible<_Opt const&, _Tp>,
-          is_convertible<_Opt&&, _Tp>,
-          is_convertible<_Opt const&&, _Tp>
-      >;
-      template <class _Up, class _Opt = optional<_Up>>
-      using __check_assignable_from_opt = __lazy_or<
-          is_assignable<_Tp&, _Opt&>,
-          is_assignable<_Tp&, _Opt const&>,
-          is_assignable<_Tp&, _Opt&&>,
-          is_assignable<_Tp&, _Opt const&&>
-      >;
-      template <class _Up, class _QUp = _QualUp>
-      static constexpr bool __enable_implicit() {
-          return is_convertible<_QUp, _Tp>::value &&
-              !__check_constructible_from_opt<_Up>::value;
-      }
-      template <class _Up, class _QUp = _QualUp>
-      static constexpr bool __enable_explicit() {
-          return !is_convertible<_QUp, _Tp>::value &&
-              !__check_constructible_from_opt<_Up>::value;
-      }
-      template <class _Up, class _QUp = _QualUp>
-      static constexpr bool __enable_assign() {
-          // Construction and assignability of _Qup to _Tp has already been
-          // checked.
-          return !__check_constructible_from_opt<_Up>::value &&
-              !__check_assignable_from_opt<_Up>::value;
-      }
-    };
-
-    template <class _Up, class _QualUp>
-    using _CheckOptionalLikeCtor = conditional_t<
-      __lazy_and<
-          __lazy_not<is_same<_Up, _Tp>>,
-          is_constructible<_Tp, _QualUp>
-      >::value,
-      _CheckOptionalLikeConstructor<_QualUp>,
-      __check_tuple_constructor_fail
-    >;
-    template <class _Up, class _QualUp>
-    using _CheckOptionalLikeAssign = conditional_t<
-      __lazy_and<
-          __lazy_not<is_same<_Up, _Tp>>,
-          is_constructible<_Tp, _QualUp>,
-          is_assignable<_Tp&, _QualUp>
-      >::value,
-      _CheckOptionalLikeConstructor<_QualUp>,
-      __check_tuple_constructor_fail
-    >;
-public:
-
-    _LIBCPP_INLINE_VISIBILITY constexpr optional() noexcept {}
-    _LIBCPP_INLINE_VISIBILITY constexpr optional(const optional&) = default;
-    _LIBCPP_INLINE_VISIBILITY constexpr optional(optional&&) = default;
-    _LIBCPP_INLINE_VISIBILITY constexpr optional(nullopt_t) noexcept {}
-
-    template <class... _Args, class = enable_if_t<
-        is_constructible_v<value_type, _Args...>>
-    >
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit optional(in_place_t, _Args&&... __args)
-        : __base(in_place, _VSTD::forward<_Args>(__args)...) {}
-
-    template <class _Up, class... _Args, class = enable_if_t<
-        is_constructible_v<value_type, initializer_list<_Up>&, _Args...>>
-    >
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit optional(in_place_t, initializer_list<_Up> __il, _Args&&... __args)
-        : __base(in_place, __il, _VSTD::forward<_Args>(__args)...) {}
-
-    template <class _Up = value_type, enable_if_t<
-        _CheckOptionalArgsCtor<_Up>::template __enable_implicit<_Up>()
-    , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr optional(_Up&& __v)
-        : __base(in_place, _VSTD::forward<_Up>(__v)) {}
-
-    template <class _Up, enable_if_t<
-        _CheckOptionalArgsCtor<_Up>::template __enable_explicit<_Up>()
-    , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit optional(_Up&& __v)
-        : __base(in_place, _VSTD::forward<_Up>(__v)) {}
-
-    // LWG2756: conditionally explicit conversion from const optional<_Up>&
-    template <class _Up, enable_if_t<
-        _CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_implicit<_Up>()
-    , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY
-    optional(const optional<_Up>& __v)
-    {
-        this->__construct_from(__v);
-    }
-    template <class _Up, enable_if_t<
-        _CheckOptionalLikeCtor<_Up, _Up const&>::template __enable_explicit<_Up>()
-    , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY
-    explicit optional(const optional<_Up>& __v)
-    {
-        this->__construct_from(__v);
-    }
-
-    // LWG2756: conditionally explicit conversion from optional<_Up>&&
-    template <class _Up, enable_if_t<
-        _CheckOptionalLikeCtor<_Up, _Up &&>::template __enable_implicit<_Up>()
-    , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY
-    optional(optional<_Up>&& __v)
-    {
-        this->__construct_from(_VSTD::move(__v));
-    }
-    template <class _Up, enable_if_t<
-        _CheckOptionalLikeCtor<_Up, _Up &&>::template __enable_explicit<_Up>()
-    , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY
-    explicit optional(optional<_Up>&& __v)
-    {
-        this->__construct_from(_VSTD::move(__v));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    optional& operator=(nullopt_t) noexcept
-    {
-        reset();
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY optional& operator=(const optional&) = default;
-    _LIBCPP_INLINE_VISIBILITY optional& operator=(optional&&) = default;
-
-    // LWG2756
-    template <class _Up = value_type,
-              class = enable_if_t
-                      <__lazy_and<
-                          integral_constant<bool,
-                              !is_same_v<__uncvref_t<_Up>, optional> &&
-                              !(is_same_v<_Up, value_type> && is_scalar_v<value_type>)
-                          >,
-                          is_constructible<value_type, _Up>,
-                          is_assignable<value_type&, _Up>
-                      >::value>
-             >
-    _LIBCPP_INLINE_VISIBILITY
-    optional&
-    operator=(_Up&& __v)
-    {
-        if (this->has_value())
-            this->__get() = _VSTD::forward<_Up>(__v);
-        else
-            this->__construct(_VSTD::forward<_Up>(__v));
-        return *this;
-    }
-
-    // LWG2756
-    template <class _Up, enable_if_t<
-        _CheckOptionalLikeAssign<_Up, _Up const&>::template __enable_assign<_Up>()
-    , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY
-    optional&
-    operator=(const optional<_Up>& __v)
-    {
-        this->__assign_from(__v);
-        return *this;
-    }
-
-    // LWG2756
-    template <class _Up, enable_if_t<
-        _CheckOptionalLikeCtor<_Up, _Up &&>::template __enable_assign<_Up>()
-    , int> = 0>
-    _LIBCPP_INLINE_VISIBILITY
-    optional&
-    operator=(optional<_Up>&& __v)
-    {
-        this->__assign_from(_VSTD::move(__v));
-        return *this;
-    }
-
-    template <class... _Args,
-              class = enable_if_t
-                      <
-                          is_constructible_v<value_type, _Args...>
-                      >
-             >
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp &
-    emplace(_Args&&... __args)
-    {
-        reset();
-        this->__construct(_VSTD::forward<_Args>(__args)...);
-        return this->__get();
-    }
-
-    template <class _Up, class... _Args,
-              class = enable_if_t
-                      <
-                          is_constructible_v<value_type, initializer_list<_Up>&, _Args...>
-                      >
-             >
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp &
-    emplace(initializer_list<_Up> __il, _Args&&... __args)
-    {
-        reset();
-        this->__construct(__il, _VSTD::forward<_Args>(__args)...);
-        return this->__get();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(optional& __opt)
-        noexcept(is_nothrow_move_constructible_v<value_type> &&
-                 is_nothrow_swappable_v<value_type>)
-    {
-        if (this->has_value() == __opt.has_value())
-        {
-            using _VSTD::swap;
-            if (this->has_value())
-                swap(this->__get(), __opt.__get());
-        }
-        else
-        {
-            if (this->has_value())
-            {
-                __opt.__construct(_VSTD::move(this->__get()));
-                reset();
-            }
-            else
-            {
-                this->__construct(_VSTD::move(__opt.__get()));
-                __opt.reset();
-            }
-        }
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr
-    add_pointer_t<value_type const>
-    operator->() const
-    {
-        _LIBCPP_ASSERT(this->has_value(), "optional operator-> called for disengaged value");
-#ifndef _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
-        return _VSTD::addressof(this->__get());
-#else
-        return __operator_arrow(__has_operator_addressof<value_type>{}, this->__get());
-#endif
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr
-    add_pointer_t<value_type>
-    operator->()
-    {
-        _LIBCPP_ASSERT(this->has_value(), "optional operator-> called for disengaged value");
-#ifndef _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
-        return _VSTD::addressof(this->__get());
-#else
-        return __operator_arrow(__has_operator_addressof<value_type>{}, this->__get());
-#endif
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr
-    const value_type&
-    operator*() const&
-    {
-        _LIBCPP_ASSERT(this->has_value(), "optional operator* called for disengaged value");
-        return this->__get();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr
-    value_type&
-    operator*() &
-    {
-        _LIBCPP_ASSERT(this->has_value(), "optional operator* called for disengaged value");
-        return this->__get();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr
-    value_type&&
-    operator*() &&
-    {
-        _LIBCPP_ASSERT(this->has_value(), "optional operator* called for disengaged value");
-        return _VSTD::move(this->__get());
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr
-    const value_type&&
-    operator*() const&&
-    {
-        _LIBCPP_ASSERT(this->has_value(), "optional operator* called for disengaged value");
-        return _VSTD::move(this->__get());
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr explicit operator bool() const noexcept { return has_value(); }
-
-    using __base::has_value;
-    using __base::__get;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
-    constexpr value_type const& value() const&
-    {
-        if (!this->has_value())
-            __throw_bad_optional_access();
-        return this->__get();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
-    constexpr value_type& value() &
-    {
-        if (!this->has_value())
-            __throw_bad_optional_access();
-        return this->__get();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
-    constexpr value_type&& value() &&
-    {
-        if (!this->has_value())
-            __throw_bad_optional_access();
-        return _VSTD::move(this->__get());
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_AVAILABILITY_THROW_BAD_OPTIONAL_ACCESS
-    constexpr value_type const&& value() const&&
-    {
-        if (!this->has_value())
-            __throw_bad_optional_access();
-        return _VSTD::move(this->__get());
-    }
-
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr value_type value_or(_Up&& __v) const&
-    {
-        static_assert(is_copy_constructible_v<value_type>,
-                      "optional<T>::value_or: T must be copy constructible");
-        static_assert(is_convertible_v<_Up, value_type>,
-                      "optional<T>::value_or: U must be convertible to T");
-        return this->has_value() ? this->__get() :
-                                  static_cast<value_type>(_VSTD::forward<_Up>(__v));
-    }
-
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr value_type value_or(_Up&& __v) &&
-    {
-        static_assert(is_move_constructible_v<value_type>,
-                      "optional<T>::value_or: T must be move constructible");
-        static_assert(is_convertible_v<_Up, value_type>,
-                      "optional<T>::value_or: U must be convertible to T");
-        return this->has_value() ? _VSTD::move(this->__get()) :
-                                  static_cast<value_type>(_VSTD::forward<_Up>(__v));
-    }
-
-    using __base::reset;
-
-private:
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    static _Up*
-    __operator_arrow(true_type, _Up& __x)
-    {
-        return _VSTD::addressof(__x);
-    }
-
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-    static constexpr _Up*
-    __operator_arrow(false_type, _Up& __x)
-    {
-        return &__x;
-    }
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class T>
-    optional(T) -> optional<T>;
-#endif
-
-// Comparisons between optionals
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() ==
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator==(const optional<_Tp>& __x, const optional<_Up>& __y)
-{
-    if (static_cast<bool>(__x) != static_cast<bool>(__y))
-        return false;
-    if (!static_cast<bool>(__x))
-        return true;
-    return *__x == *__y;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() !=
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator!=(const optional<_Tp>& __x, const optional<_Up>& __y)
-{
-    if (static_cast<bool>(__x) != static_cast<bool>(__y))
-        return true;
-    if (!static_cast<bool>(__x))
-        return false;
-    return *__x != *__y;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator<(const optional<_Tp>& __x, const optional<_Up>& __y)
-{
-    if (!static_cast<bool>(__y))
-        return false;
-    if (!static_cast<bool>(__x))
-        return true;
-    return *__x < *__y;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator>(const optional<_Tp>& __x, const optional<_Up>& __y)
-{
-    if (!static_cast<bool>(__x))
-        return false;
-    if (!static_cast<bool>(__y))
-        return true;
-    return *__x > *__y;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <=
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator<=(const optional<_Tp>& __x, const optional<_Up>& __y)
-{
-    if (!static_cast<bool>(__x))
-        return true;
-    if (!static_cast<bool>(__y))
-        return false;
-    return *__x <= *__y;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >=
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator>=(const optional<_Tp>& __x, const optional<_Up>& __y)
-{
-    if (!static_cast<bool>(__y))
-        return true;
-    if (!static_cast<bool>(__x))
-        return false;
-    return *__x >= *__y;
-}
-
-// Comparisons with nullopt
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator==(const optional<_Tp>& __x, nullopt_t) noexcept
-{
-    return !static_cast<bool>(__x);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator==(nullopt_t, const optional<_Tp>& __x) noexcept
-{
-    return !static_cast<bool>(__x);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator!=(const optional<_Tp>& __x, nullopt_t) noexcept
-{
-    return static_cast<bool>(__x);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator!=(nullopt_t, const optional<_Tp>& __x) noexcept
-{
-    return static_cast<bool>(__x);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator<(const optional<_Tp>&, nullopt_t) noexcept
-{
-    return false;
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator<(nullopt_t, const optional<_Tp>& __x) noexcept
-{
-    return static_cast<bool>(__x);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator<=(const optional<_Tp>& __x, nullopt_t) noexcept
-{
-    return !static_cast<bool>(__x);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator<=(nullopt_t, const optional<_Tp>&) noexcept
-{
-    return true;
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator>(const optional<_Tp>& __x, nullopt_t) noexcept
-{
-    return static_cast<bool>(__x);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator>(nullopt_t, const optional<_Tp>&) noexcept
-{
-    return false;
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator>=(const optional<_Tp>&, nullopt_t) noexcept
-{
-    return true;
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-bool
-operator>=(nullopt_t, const optional<_Tp>& __x) noexcept
-{
-    return !static_cast<bool>(__x);
-}
-
-// Comparisons with T
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() ==
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator==(const optional<_Tp>& __x, const _Up& __v)
-{
-    return static_cast<bool>(__x) ? *__x == __v : false;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() ==
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator==(const _Tp& __v, const optional<_Up>& __x)
-{
-    return static_cast<bool>(__x) ? __v == *__x : false;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() !=
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator!=(const optional<_Tp>& __x, const _Up& __v)
-{
-    return static_cast<bool>(__x) ? *__x != __v : true;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() !=
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator!=(const _Tp& __v, const optional<_Up>& __x)
-{
-    return static_cast<bool>(__x) ? __v != *__x : true;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator<(const optional<_Tp>& __x, const _Up& __v)
-{
-    return static_cast<bool>(__x) ? *__x < __v : true;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator<(const _Tp& __v, const optional<_Up>& __x)
-{
-    return static_cast<bool>(__x) ? __v < *__x : false;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <=
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator<=(const optional<_Tp>& __x, const _Up& __v)
-{
-    return static_cast<bool>(__x) ? *__x <= __v : true;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() <=
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator<=(const _Tp& __v, const optional<_Up>& __x)
-{
-    return static_cast<bool>(__x) ? __v <= *__x : false;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator>(const optional<_Tp>& __x, const _Up& __v)
-{
-    return static_cast<bool>(__x) ? *__x > __v : false;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator>(const _Tp& __v, const optional<_Up>& __x)
-{
-    return static_cast<bool>(__x) ? __v > *__x : true;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >=
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator>=(const optional<_Tp>& __x, const _Up& __v)
-{
-    return static_cast<bool>(__x) ? *__x >= __v : false;
-}
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VISIBILITY constexpr
-enable_if_t<
-    is_convertible_v<decltype(_VSTD::declval<const _Tp&>() >=
-        _VSTD::declval<const _Up&>()), bool>,
-    bool
->
-operator>=(const _Tp& __v, const optional<_Up>& __x)
-{
-    return static_cast<bool>(__x) ? __v >= *__x : true;
-}
-
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-enable_if_t<
-    is_move_constructible_v<_Tp> && is_swappable_v<_Tp>,
-    void
->
-swap(optional<_Tp>& __x, optional<_Tp>& __y) noexcept(noexcept(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY constexpr
-optional<decay_t<_Tp>> make_optional(_Tp&& __v)
-{
-    return optional<decay_t<_Tp>>(_VSTD::forward<_Tp>(__v));
-}
-
-template <class _Tp, class... _Args>
-_LIBCPP_INLINE_VISIBILITY constexpr
-optional<_Tp> make_optional(_Args&&... __args)
-{
-    return optional<_Tp>(in_place, _VSTD::forward<_Args>(__args)...);
-}
-
-template <class _Tp, class _Up, class... _Args>
-_LIBCPP_INLINE_VISIBILITY constexpr
-optional<_Tp> make_optional(initializer_list<_Up> __il,  _Args&&... __args)
-{
-    return optional<_Tp>(in_place, __il, _VSTD::forward<_Args>(__args)...);
-}
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS hash<
-    __enable_hash_helper<optional<_Tp>, remove_const_t<_Tp>>
->
-{
-    typedef optional<_Tp> argument_type;
-    typedef size_t        result_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator()(const argument_type& __opt) const
-    {
-        return static_cast<bool>(__opt) ? hash<remove_const_t<_Tp>>()(*__opt) : 0;
-    }
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_STD_VER > 14
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_OPTIONAL
diff --git a/lib/libcxx/include/ostream b/lib/libcxx/include/ostream
deleted file mode 100644
index d700a369b34..00000000000
--- a/lib/libcxx/include/ostream
+++ /dev/null
@@ -1,1103 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- ostream -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_OSTREAM
-#define _LIBCPP_OSTREAM
-
-/*
-    ostream synopsis
-
-template <class charT, class traits = char_traits<charT> >
-class basic_ostream
-    : virtual public basic_ios<charT,traits>
-{
-public:
-    // types (inherited from basic_ios (27.5.4)):
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    // 27.7.2.2 Constructor/destructor:
-    explicit basic_ostream(basic_streambuf<char_type,traits>* sb);
-    basic_ostream(basic_ostream&& rhs);
-    virtual ~basic_ostream();
-
-    // 27.7.2.3 Assign/swap
-    basic_ostream& operator=(const basic_ostream& rhs) = delete; // C++14
-    basic_ostream& operator=(basic_ostream&& rhs);
-    void swap(basic_ostream& rhs);
-
-    // 27.7.2.4 Prefix/suffix:
-    class sentry;
-
-    // 27.7.2.6 Formatted output:
-    basic_ostream& operator<<(basic_ostream& (*pf)(basic_ostream&));
-    basic_ostream& operator<<(basic_ios<charT, traits>& (*pf)(basic_ios<charT,traits>&));
-    basic_ostream& operator<<(ios_base& (*pf)(ios_base&));
-    basic_ostream& operator<<(bool n);
-    basic_ostream& operator<<(short n);
-    basic_ostream& operator<<(unsigned short n);
-    basic_ostream& operator<<(int n);
-    basic_ostream& operator<<(unsigned int n);
-    basic_ostream& operator<<(long n);
-    basic_ostream& operator<<(unsigned long n);
-    basic_ostream& operator<<(long long n);
-    basic_ostream& operator<<(unsigned long long n);
-    basic_ostream& operator<<(float f);
-    basic_ostream& operator<<(double f);
-    basic_ostream& operator<<(long double f);
-    basic_ostream& operator<<(const void* p);
-    basic_ostream& operator<<(basic_streambuf<char_type,traits>* sb);
-
-    // 27.7.2.7 Unformatted output:
-    basic_ostream& put(char_type c);
-    basic_ostream& write(const char_type* s, streamsize n);
-    basic_ostream& flush();
-
-    // 27.7.2.5 seeks:
-    pos_type tellp();
-    basic_ostream& seekp(pos_type);
-    basic_ostream& seekp(off_type, ios_base::seekdir);
-protected:
-    basic_ostream(const basic_ostream& rhs) = delete;
-    basic_ostream(basic_ostream&& rhs);
-    // 27.7.3.3 Assign/swap
-    basic_ostream& operator=(basic_ostream& rhs) = delete;
-    basic_ostream& operator=(const basic_ostream&& rhs);
-    void swap(basic_ostream& rhs);
-};
-
-// 27.7.2.6.4 character inserters
-
-template<class charT, class traits>
-  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>&, charT);
-
-template<class charT, class traits>
-  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>&, char);
-
-template<class traits>
-  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, char);
-
-// signed and unsigned
-
-template<class traits>
-  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, signed char);
-
-template<class traits>
-  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, unsigned char);
-
-// NTBS
-template<class charT, class traits>
-  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>&, const charT*);
-
-template<class charT, class traits>
-  basic_ostream<charT,traits>& operator<<(basic_ostream<charT,traits>&, const char*);
-
-template<class traits>
-  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, const char*);
-
-// signed and unsigned
-template<class traits>
-basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, const signed char*);
-
-template<class traits>
-  basic_ostream<char,traits>& operator<<(basic_ostream<char,traits>&, const unsigned char*);
-
-// swap:
-template <class charT, class traits>
-  void swap(basic_ostream<charT, traits>& x, basic_ostream<charT, traits>& y);
-
-template <class charT, class traits>
-  basic_ostream<charT,traits>& endl(basic_ostream<charT,traits>& os);
-
-template <class charT, class traits>
-  basic_ostream<charT,traits>& ends(basic_ostream<charT,traits>& os);
-
-template <class charT, class traits>
-  basic_ostream<charT,traits>& flush(basic_ostream<charT,traits>& os);
-
-// rvalue stream insertion
-template <class charT, class traits, class T>
-  basic_ostream<charT, traits>&
-  operator<<(basic_ostream<charT, traits>&& os, const T& x);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <ios>
-#include <streambuf>
-#include <locale>
-#include <iterator>
-#include <bitset>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_ostream
-    : virtual public basic_ios<_CharT, _Traits>
-{
-public:
-    // types (inherited from basic_ios (27.5.4)):
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    // 27.7.2.2 Constructor/destructor:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    explicit basic_ostream(basic_streambuf<char_type, traits_type>* __sb)
-    { this->init(__sb); }
-    virtual ~basic_ostream();
-protected:
-#ifndef _LIBCPP_CXX03_LANG
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_ostream(basic_ostream&& __rhs);
-
-    // 27.7.2.3 Assign/swap
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_ostream& operator=(basic_ostream&& __rhs);
-#endif
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    void swap(basic_ostream& __rhs)
-    { basic_ios<char_type, traits_type>::swap(__rhs); }
-
-#ifndef _LIBCPP_CXX03_LANG
-    basic_ostream           (const basic_ostream& __rhs) = delete;
-    basic_ostream& operator=(const basic_ostream& __rhs) = delete;
-#else
-    basic_ostream           (const basic_ostream& __rhs); // not defined
-    basic_ostream& operator=(const basic_ostream& __rhs); // not defined
-#endif
-public:
-
-    // 27.7.2.4 Prefix/suffix:
-    class _LIBCPP_TEMPLATE_VIS sentry;
-
-    // 27.7.2.6 Formatted output:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_ostream& operator<<(basic_ostream& (*__pf)(basic_ostream&))
-    { return __pf(*this); }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_ostream& operator<<(basic_ios<char_type, traits_type>&
-                              (*__pf)(basic_ios<char_type,traits_type>&))
-    { __pf(*this); return *this; }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_ostream& operator<<(ios_base& (*__pf)(ios_base&))
-    { __pf(*this); return *this; }
-
-    basic_ostream& operator<<(bool __n);
-    basic_ostream& operator<<(short __n);
-    basic_ostream& operator<<(unsigned short __n);
-    basic_ostream& operator<<(int __n);
-    basic_ostream& operator<<(unsigned int __n);
-    basic_ostream& operator<<(long __n);
-    basic_ostream& operator<<(unsigned long __n);
-    basic_ostream& operator<<(long long __n);
-    basic_ostream& operator<<(unsigned long long __n);
-    basic_ostream& operator<<(float __f);
-    basic_ostream& operator<<(double __f);
-    basic_ostream& operator<<(long double __f);
-    basic_ostream& operator<<(const void* __p);
-    basic_ostream& operator<<(basic_streambuf<char_type, traits_type>* __sb);
-
-    // 27.7.2.7 Unformatted output:
-    basic_ostream& put(char_type __c);
-    basic_ostream& write(const char_type* __s, streamsize __n);
-    basic_ostream& flush();
-
-    // 27.7.2.5 seeks:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    pos_type tellp();
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_ostream& seekp(pos_type __pos);
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_ostream& seekp(off_type __off, ios_base::seekdir __dir);
-
-protected:
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ostream() {}  // extension, intentially does not initialize
-};
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_ostream<_CharT, _Traits>::sentry
-{
-    bool __ok_;
-    basic_ostream<_CharT, _Traits>& __os_;
-
-    sentry(const sentry&); // = delete;
-    sentry& operator=(const sentry&); // = delete;
-
-public:
-    explicit sentry(basic_ostream<_CharT, _Traits>& __os);
-    ~sentry();
-
-    _LIBCPP_INLINE_VISIBILITY
-        _LIBCPP_EXPLICIT
-        operator bool() const {return __ok_;}
-};
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>::sentry::sentry(basic_ostream<_CharT, _Traits>& __os)
-    : __ok_(false),
-      __os_(__os)
-{
-    if (__os.good())
-    {
-        if (__os.tie())
-            __os.tie()->flush();
-        __ok_ = true;
-    }
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>::sentry::~sentry()
-{
-    if (__os_.rdbuf() && __os_.good() && (__os_.flags() & ios_base::unitbuf)
-                      && !uncaught_exception())
-    {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            if (__os_.rdbuf()->pubsync() == -1)
-                __os_.setstate(ios_base::badbit);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>::basic_ostream(basic_ostream&& __rhs)
-{
-    this->move(__rhs);
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator=(basic_ostream&& __rhs)
-{
-    swap(__rhs);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>::~basic_ostream()
-{
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(basic_streambuf<char_type, traits_type>* __sb)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            if (__sb)
-            {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-                try
-                {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-                    typedef istreambuf_iterator<_CharT, _Traits> _Ip;
-                    typedef ostreambuf_iterator<_CharT, _Traits> _Op;
-                    _Ip __i(__sb);
-                    _Ip __eof;
-                    _Op __o(*this);
-                    size_t __c = 0;
-                    for (; __i != __eof; ++__i, ++__o, ++__c)
-                    {
-                        *__o = *__i;
-                        if (__o.failed())
-                            break;
-                    }
-                    if (__c == 0)
-                        this->setstate(ios_base::failbit);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-                }
-                catch (...)
-                {
-                    this->__set_failbit_and_consider_rethrow();
-                }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            }
-            else
-                this->setstate(ios_base::badbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(bool __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), __n).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(short __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            ios_base::fmtflags __flags = ios_base::flags() & ios_base::basefield;
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(),
-                        __flags == ios_base::oct || __flags == ios_base::hex ?
-                        static_cast<long>(static_cast<unsigned short>(__n))  :
-                        static_cast<long>(__n)).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(unsigned short __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), static_cast<unsigned long>(__n)).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(int __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            ios_base::fmtflags __flags = ios_base::flags() & ios_base::basefield;
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(),
-                        __flags == ios_base::oct || __flags == ios_base::hex ?
-                        static_cast<long>(static_cast<unsigned int>(__n))  :
-                        static_cast<long>(__n)).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(unsigned int __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), static_cast<unsigned long>(__n)).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(long __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), __n).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(unsigned long __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), __n).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(long long __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), __n).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(unsigned long long __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), __n).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(float __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), static_cast<double>(__n)).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(double __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), __n).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(long double __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), __n).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::operator<<(const void* __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef num_put<char_type, ostreambuf_iterator<char_type, traits_type> > _Fp;
-            const _Fp& __f = use_facet<_Fp>(this->getloc());
-            if (__f.put(*this, *this, this->fill(), __n).failed())
-                this->setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template<class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-__put_character_sequence(basic_ostream<_CharT, _Traits>& __os,
-                          const _CharT* __str, size_t __len)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
-        if (__s)
-        {
-            typedef ostreambuf_iterator<_CharT, _Traits> _Ip;
-            if (__pad_and_output(_Ip(__os),
-                                 __str,
-                                 (__os.flags() & ios_base::adjustfield) == ios_base::left ?
-                                     __str + __len :
-                                     __str,
-                                 __str + __len,
-                                 __os,
-                                 __os.fill()).failed())
-                __os.setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __os.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __os;
-}
-
-
-template<class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, _CharT __c)
-{
-    return _VSTD::__put_character_sequence(__os, &__c, 1);
-}
-
-template<class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, char __cn)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
-        if (__s)
-        {
-            _CharT __c = __os.widen(__cn);
-            typedef ostreambuf_iterator<_CharT, _Traits> _Ip;
-            if (__pad_and_output(_Ip(__os),
-                                 &__c,
-                                 (__os.flags() & ios_base::adjustfield) == ios_base::left ?
-                                     &__c + 1 :
-                                     &__c,
-                                 &__c + 1,
-                                 __os,
-                                 __os.fill()).failed())
-                __os.setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __os.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __os;
-}
-
-template<class _Traits>
-basic_ostream<char, _Traits>&
-operator<<(basic_ostream<char, _Traits>& __os, char __c)
-{
-    return _VSTD::__put_character_sequence(__os, &__c, 1);
-}
-
-template<class _Traits>
-basic_ostream<char, _Traits>&
-operator<<(basic_ostream<char, _Traits>& __os, signed char __c)
-{
-    return _VSTD::__put_character_sequence(__os, (char *) &__c, 1);
-}
-
-template<class _Traits>
-basic_ostream<char, _Traits>&
-operator<<(basic_ostream<char, _Traits>& __os, unsigned char __c)
-{
-    return _VSTD::__put_character_sequence(__os, (char *) &__c, 1);
-}
-
-template<class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const _CharT* __str)
-{
-    return _VSTD::__put_character_sequence(__os, __str, _Traits::length(__str));
-}
-
-template<class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const char* __strn)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        typename basic_ostream<_CharT, _Traits>::sentry __s(__os);
-        if (__s)
-        {
-            typedef ostreambuf_iterator<_CharT, _Traits> _Ip;
-            size_t __len = char_traits<char>::length(__strn);
-            const int __bs = 100;
-            _CharT __wbb[__bs];
-            _CharT* __wb = __wbb;
-            unique_ptr<_CharT, void(*)(void*)> __h(0, free);
-            if (__len > __bs)
-            {
-                __wb = (_CharT*)malloc(__len*sizeof(_CharT));
-                if (__wb == 0)
-                    __throw_bad_alloc();
-                __h.reset(__wb);
-            }
-            for (_CharT* __p = __wb; *__strn != '\0'; ++__strn, ++__p)
-                *__p = __os.widen(*__strn);
-            if (__pad_and_output(_Ip(__os),
-                                 __wb,
-                                 (__os.flags() & ios_base::adjustfield) == ios_base::left ?
-                                     __wb + __len :
-                                     __wb,
-                                 __wb + __len,
-                                 __os,
-                                 __os.fill()).failed())
-                __os.setstate(ios_base::badbit | ios_base::failbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        __os.__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __os;
-}
-
-template<class _Traits>
-basic_ostream<char, _Traits>&
-operator<<(basic_ostream<char, _Traits>& __os, const char* __str)
-{
-    return _VSTD::__put_character_sequence(__os, __str, _Traits::length(__str));
-}
-
-template<class _Traits>
-basic_ostream<char, _Traits>&
-operator<<(basic_ostream<char, _Traits>& __os, const signed char* __str)
-{
-    const char *__s = (const char *) __str;
-    return _VSTD::__put_character_sequence(__os, __s, _Traits::length(__s));
-}
-
-template<class _Traits>
-basic_ostream<char, _Traits>&
-operator<<(basic_ostream<char, _Traits>& __os, const unsigned char* __str)
-{
-    const char *__s = (const char *) __str;
-    return _VSTD::__put_character_sequence(__os, __s, _Traits::length(__s));
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::put(char_type __c)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __s(*this);
-        if (__s)
-        {
-            typedef ostreambuf_iterator<_CharT, _Traits> _Op;
-            _Op __o(*this);
-            *__o = __c;
-            if (__o.failed())
-                this->setstate(ios_base::badbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::write(const char_type* __s, streamsize __n)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        sentry __sen(*this);
-        if (__sen && __n)
-        {
-            if (this->rdbuf()->sputn(__s, __n) != __n)
-                this->setstate(ios_base::badbit);
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::flush()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        if (this->rdbuf())
-        {
-            sentry __s(*this);
-            if (__s)
-            {
-                if (this->rdbuf()->pubsync() == -1)
-                    this->setstate(ios_base::badbit);
-            }
-        }
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        this->__set_badbit_and_consider_rethrow();
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-typename basic_ostream<_CharT, _Traits>::pos_type
-basic_ostream<_CharT, _Traits>::tellp()
-{
-    if (this->fail())
-        return pos_type(-1);
-    return this->rdbuf()->pubseekoff(0, ios_base::cur, ios_base::out);
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::seekp(pos_type __pos)
-{
-    sentry __s(*this);
-    if (!this->fail())
-    {
-        if (this->rdbuf()->pubseekpos(__pos, ios_base::out) == pos_type(-1))
-            this->setstate(ios_base::failbit);
-    }
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-basic_ostream<_CharT, _Traits>::seekp(off_type __off, ios_base::seekdir __dir)
-{
-    sentry __s(*this);
-    if (!this->fail())
-    {
-        if (this->rdbuf()->pubseekoff(__off, __dir, ios_base::out) == pos_type(-1))
-            this->setstate(ios_base::failbit);
-    }
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>&
-endl(basic_ostream<_CharT, _Traits>& __os)
-{
-    __os.put(__os.widen('\n'));
-    __os.flush();
-    return __os;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>&
-ends(basic_ostream<_CharT, _Traits>& __os)
-{
-    __os.put(_CharT());
-    return __os;
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>&
-flush(basic_ostream<_CharT, _Traits>& __os)
-{
-    __os.flush();
-    return __os;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Stream, class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    !is_lvalue_reference<_Stream>::value &&
-    is_base_of<ios_base, _Stream>::value,
-    _Stream&&
->::type
-operator<<(_Stream&& __os, const _Tp& __x)
-{
-    __os << __x;
-    return _VSTD::move(__os);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const basic_string<_CharT, _Traits, _Allocator>& __str)
-{
-    return _VSTD::__put_character_sequence(__os, __str.data(), __str.size());
-}
-
-template<class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const basic_string_view<_CharT, _Traits> __sv)
-{
-    return _VSTD::__put_character_sequence(__os, __sv.data(), __sv.size());
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const error_code& __ec)
-{
-    return __os << __ec.category().name() << ':' << __ec.value();
-}
-
-template<class _CharT, class _Traits, class _Yp>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p)
-{
-    return __os << __p.get();
-}
-
-template<class _CharT, class _Traits, class _Yp, class _Dp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    is_same<void, typename __void_t<decltype((declval<basic_ostream<_CharT, _Traits>&>() << declval<typename unique_ptr<_Yp, _Dp>::pointer>()))>::type>::value,
-    basic_ostream<_CharT, _Traits>&
->::type
-operator<<(basic_ostream<_CharT, _Traits>& __os, unique_ptr<_Yp, _Dp> const& __p)
-{
-    return __os << __p.get();
-}
-
-template <class _CharT, class _Traits, size_t _Size>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const bitset<_Size>& __x)
-{
-    return __os << __x.template to_string<_CharT, _Traits>
-                        (use_facet<ctype<_CharT> >(__os.getloc()).widen('0'),
-                         use_facet<ctype<_CharT> >(__os.getloc()).widen('1'));
-}
-
-#ifndef _LIBCPP_DO_NOT_ASSUME_STREAMS_EXPLICIT_INSTANTIATION_IN_DYLIB
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ostream<char>)
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ostream<wchar_t>)
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_OSTREAM
diff --git a/lib/libcxx/include/queue b/lib/libcxx/include/queue
deleted file mode 100644
index 4677e52ae3a..00000000000
--- a/lib/libcxx/include/queue
+++ /dev/null
@@ -1,804 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- queue ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_QUEUE
-#define _LIBCPP_QUEUE
-
-/*
-    queue synopsis
-
-namespace std
-{
-
-template <class T, class Container = deque<T>>
-class queue
-{
-public:
-    typedef Container                                container_type;
-    typedef typename container_type::value_type      value_type;
-    typedef typename container_type::reference       reference;
-    typedef typename container_type::const_reference const_reference;
-    typedef typename container_type::size_type       size_type;
-
-protected:
-    container_type c;
-
-public:
-    queue() = default;
-    ~queue() = default;
-
-    queue(const queue& q) = default;
-    queue(queue&& q) = default;
-
-    queue& operator=(const queue& q) = default;
-    queue& operator=(queue&& q) = default;
-
-    explicit queue(const container_type& c);
-    explicit queue(container_type&& c)
-    template <class Alloc>
-        explicit queue(const Alloc& a);
-    template <class Alloc>
-        queue(const container_type& c, const Alloc& a);
-    template <class Alloc>
-        queue(container_type&& c, const Alloc& a);
-    template <class Alloc>
-        queue(const queue& q, const Alloc& a);
-    template <class Alloc>
-        queue(queue&& q, const Alloc& a);
-
-    bool      empty() const;
-    size_type size() const;
-
-    reference       front();
-    const_reference front() const;
-    reference       back();
-    const_reference back() const;
-
-    void push(const value_type& v);
-    void push(value_type&& v);
-    template <class... Args> reference emplace(Args&&... args); // reference in C++17
-    void pop();
-
-    void swap(queue& q) noexcept(is_nothrow_swappable_v<Container>)
-};
-
-template<class Container>
-  queue(Container) -> queue<typename Container::value_type, Container>; // C++17
-  
-template<class Container, class Allocator> 
-  queue(Container, Allocator) -> queue<typename Container::value_type, Container>; // C++17
-
-template <class T, class Container>
-  bool operator==(const queue<T, Container>& x,const queue<T, Container>& y);
-
-template <class T, class Container>
-  bool operator< (const queue<T, Container>& x,const queue<T, Container>& y);
-
-template <class T, class Container>
-  bool operator!=(const queue<T, Container>& x,const queue<T, Container>& y);
-
-template <class T, class Container>
-  bool operator> (const queue<T, Container>& x,const queue<T, Container>& y);
-
-template <class T, class Container>
-  bool operator>=(const queue<T, Container>& x,const queue<T, Container>& y);
-
-template <class T, class Container>
-  bool operator<=(const queue<T, Container>& x,const queue<T, Container>& y);
-
-template <class T, class Container>
-  void swap(queue<T, Container>& x, queue<T, Container>& y)
-  noexcept(noexcept(x.swap(y)));
-
-template <class T, class Container = vector<T>,
-          class Compare = less<typename Container::value_type>>
-class priority_queue
-{
-public:
-    typedef Container                                container_type;
-    typedef typename container_type::value_type      value_type;
-    typedef typename container_type::reference       reference;
-    typedef typename container_type::const_reference const_reference;
-    typedef typename container_type::size_type       size_type;
-
-protected:
-    container_type c;
-    Compare comp;
-
-public:
-    priority_queue() = default;
-    ~priority_queue() = default;
-
-    priority_queue(const priority_queue& q) = default;
-    priority_queue(priority_queue&& q) = default;
-
-    priority_queue& operator=(const priority_queue& q) = default;
-    priority_queue& operator=(priority_queue&& q) = default;
-
-    explicit priority_queue(const Compare& comp);
-    priority_queue(const Compare& comp, const container_type& c);
-    explicit priority_queue(const Compare& comp, container_type&& c);
-    template <class InputIterator>
-        priority_queue(InputIterator first, InputIterator last,
-                       const Compare& comp = Compare());
-    template <class InputIterator>
-        priority_queue(InputIterator first, InputIterator last,
-                       const Compare& comp, const container_type& c);
-    template <class InputIterator>
-        priority_queue(InputIterator first, InputIterator last,
-                       const Compare& comp, container_type&& c);
-    template <class Alloc>
-        explicit priority_queue(const Alloc& a);
-    template <class Alloc>
-        priority_queue(const Compare& comp, const Alloc& a);
-    template <class Alloc>
-        priority_queue(const Compare& comp, const container_type& c,
-                       const Alloc& a);
-    template <class Alloc>
-        priority_queue(const Compare& comp, container_type&& c,
-                       const Alloc& a);
-    template <class Alloc>
-        priority_queue(const priority_queue& q, const Alloc& a);
-    template <class Alloc>
-        priority_queue(priority_queue&& q, const Alloc& a);
-
-    bool            empty() const;
-    size_type       size() const;
-    const_reference top() const;
-
-    void push(const value_type& v);
-    void push(value_type&& v);
-    template <class... Args> void emplace(Args&&... args);
-    void pop();
-
-    void swap(priority_queue& q)
-        noexcept(is_nothrow_swappable_v<Container> &&
-                 is_nothrow_swappable_v<Comp>)
-};
-
-template <class Compare, class Container>
-priority_queue(Compare, Container)
-    -> priority_queue<typename Container::value_type, Container, Compare>; // C++17
-  
-template<class InputIterator, 
-         class Compare = less<typename iterator_traits<InputIterator>::value_type>,
-         class Container = vector<typename iterator_traits<InputIterator>::value_type>>
-priority_queue(InputIterator, InputIterator, Compare = Compare(), Container = Container())
-    -> priority_queue<typename iterator_traits<InputIterator>::value_type, Container, Compare>; // C++17
-  
-template<class Compare, class Container, class Allocator>
-priority_queue(Compare, Container, Allocator)
-    -> priority_queue<typename Container::value_type, Container, Compare>; // C++17
-
-template <class T, class Container, class Compare>
-  void swap(priority_queue<T, Container, Compare>& x,
-            priority_queue<T, Container, Compare>& y)
-            noexcept(noexcept(x.swap(y)));
-
-}  // std
-
-*/
-
-#include <__config>
-#include <deque>
-#include <vector>
-#include <functional>
-#include <algorithm>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp, class _Container = deque<_Tp> > class _LIBCPP_TEMPLATE_VIS queue;
-
-template <class _Tp, class _Container>
-_LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y);
-
-template <class _Tp, class _Container>
-_LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y);
-
-template <class _Tp, class _Container /*= deque<_Tp>*/>
-class _LIBCPP_TEMPLATE_VIS queue
-{
-public:
-    typedef _Container                               container_type;
-    typedef typename container_type::value_type      value_type;
-    typedef typename container_type::reference       reference;
-    typedef typename container_type::const_reference const_reference;
-    typedef typename container_type::size_type       size_type;
-    static_assert((is_same<_Tp, value_type>::value), "" );
-
-protected:
-    container_type c;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    queue()
-        _NOEXCEPT_(is_nothrow_default_constructible<container_type>::value)
-        : c() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    queue(const queue& __q) : c(__q.c) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    queue& operator=(const queue& __q) {c = __q.c; return *this;}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    queue(queue&& __q)
-        _NOEXCEPT_(is_nothrow_move_constructible<container_type>::value)
-        : c(_VSTD::move(__q.c)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    queue& operator=(queue&& __q)
-        _NOEXCEPT_(is_nothrow_move_assignable<container_type>::value)
-        {c = _VSTD::move(__q.c); return *this;}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit queue(const container_type& __c)  : c(__c) {}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    explicit queue(container_type&& __c) : c(_VSTD::move(__c)) {}
-#endif  // _LIBCPP_CXX03_LANG
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit queue(const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0)
-            : c(__a) {}
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        queue(const queue& __q, const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0)
-            : c(__q.c, __a) {}
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        queue(const container_type& __c, const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0)
-            : c(__c, __a) {}
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        queue(container_type&& __c, const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0)
-            : c(_VSTD::move(__c), __a) {}
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        queue(queue&& __q, const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0)
-            : c(_VSTD::move(__q.c), __a) {}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const {return c.empty();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const  {return c.size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference       front()       {return c.front();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference front() const {return c.front();}
-    _LIBCPP_INLINE_VISIBILITY
-    reference       back()        {return c.back();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference back() const  {return c.back();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void push(const value_type& __v) {c.push_back(__v);}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void push(value_type&& __v)      {c.push_back(_VSTD::move(__v));}
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-#if _LIBCPP_STD_VER > 14
-        decltype(auto) emplace(_Args&&... __args)
-            { return c.emplace_back(_VSTD::forward<_Args>(__args)...);}
-#else
-        void     emplace(_Args&&... __args)
-            {        c.emplace_back(_VSTD::forward<_Args>(__args)...);}
-#endif
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void pop() {c.pop_front();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(queue& __q)
-        _NOEXCEPT_(__is_nothrow_swappable<container_type>::value)
-    {
-        using _VSTD::swap;
-        swap(c, __q.c);
-    }
-
-    template <class _T1, class _C1>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    bool
-    operator==(const queue<_T1, _C1>& __x,const queue<_T1, _C1>& __y);
-
-    template <class _T1, class _C1>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    bool
-    operator< (const queue<_T1, _C1>& __x,const queue<_T1, _C1>& __y);
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class _Container,
-         class = typename enable_if<!__is_allocator<_Container>::value, nullptr_t>::type
->
-queue(_Container)
-    -> queue<typename _Container::value_type, _Container>;
-  
-template<class _Container,
-         class _Alloc,
-         class = typename enable_if<!__is_allocator<_Container>::value, nullptr_t>::type,
-         class = typename enable_if< __is_allocator<_Alloc>::value, nullptr_t>::type
->
-queue(_Container, _Alloc)
-    -> queue<typename _Container::value_type, _Container>;
-#endif
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
-{
-    return __x.c == __y.c;
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
-{
-    return __x.c < __y.c;
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const queue<_Tp, _Container>& __x,const queue<_Tp, _Container>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if<
-    __is_swappable<_Container>::value,
-    void
->::type
-swap(queue<_Tp, _Container>& __x, queue<_Tp, _Container>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-template <class _Tp, class _Container, class _Alloc>
-struct _LIBCPP_TEMPLATE_VIS uses_allocator<queue<_Tp, _Container>, _Alloc>
-    : public uses_allocator<_Container, _Alloc>
-{
-};
-
-template <class _Tp, class _Container = vector<_Tp>,
-          class _Compare = less<typename _Container::value_type> >
-class _LIBCPP_TEMPLATE_VIS priority_queue
-{
-public:
-    typedef _Container                               container_type;
-    typedef _Compare                                 value_compare;
-    typedef typename container_type::value_type      value_type;
-    typedef typename container_type::reference       reference;
-    typedef typename container_type::const_reference const_reference;
-    typedef typename container_type::size_type       size_type;
-    static_assert((is_same<_Tp, value_type>::value), "" );
-
-protected:
-    container_type c;
-    value_compare comp;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    priority_queue()
-        _NOEXCEPT_(is_nothrow_default_constructible<container_type>::value &&
-                   is_nothrow_default_constructible<value_compare>::value)
-        : c(), comp() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    priority_queue(const priority_queue& __q) : c(__q.c), comp(__q.comp) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    priority_queue& operator=(const priority_queue& __q)
-        {c = __q.c; comp = __q.comp; return *this;}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    priority_queue(priority_queue&& __q)
-        _NOEXCEPT_(is_nothrow_move_constructible<container_type>::value &&
-                   is_nothrow_move_constructible<value_compare>::value)
-        : c(_VSTD::move(__q.c)), comp(_VSTD::move(__q.comp)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    priority_queue& operator=(priority_queue&& __q)
-        _NOEXCEPT_(is_nothrow_move_assignable<container_type>::value &&
-                   is_nothrow_move_assignable<value_compare>::value)
-        {c = _VSTD::move(__q.c); comp = _VSTD::move(__q.comp); return *this;}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit priority_queue(const value_compare& __comp)
-        : c(), comp(__comp) {}
-    _LIBCPP_INLINE_VISIBILITY
-    priority_queue(const value_compare& __comp, const container_type& __c);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    explicit priority_queue(const value_compare& __comp, container_type&& __c);
-#endif
-    template <class _InputIter>
-        _LIBCPP_INLINE_VISIBILITY
-        priority_queue(_InputIter __f, _InputIter __l,
-                       const value_compare& __comp = value_compare());
-    template <class _InputIter>
-        _LIBCPP_INLINE_VISIBILITY
-        priority_queue(_InputIter __f, _InputIter __l,
-                       const value_compare& __comp, const container_type& __c);
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _InputIter>
-        _LIBCPP_INLINE_VISIBILITY
-        priority_queue(_InputIter __f, _InputIter __l,
-                       const value_compare& __comp, container_type&& __c);
-#endif  // _LIBCPP_CXX03_LANG
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit priority_queue(const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0);
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        priority_queue(const value_compare& __comp, const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0);
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        priority_queue(const value_compare& __comp, const container_type& __c,
-                       const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0);
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        priority_queue(const priority_queue& __q, const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0);
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        priority_queue(const value_compare& __comp, container_type&& __c,
-                       const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0);
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        priority_queue(priority_queue&& __q, const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0);
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool            empty() const {return c.empty();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type       size() const  {return c.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference top() const   {return c.front();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void push(const value_type& __v);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void push(value_type&& __v);
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    void emplace(_Args&&... __args);
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void pop();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(priority_queue& __q)
-        _NOEXCEPT_(__is_nothrow_swappable<container_type>::value &&
-                   __is_nothrow_swappable<value_compare>::value);
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template <class _Compare,
-          class _Container,
-          class = typename enable_if<!__is_allocator<_Compare>::value, nullptr_t>::type,
-          class = typename enable_if<!__is_allocator<_Container>::value, nullptr_t>::type
->
-priority_queue(_Compare, _Container)
-    -> priority_queue<typename _Container::value_type, _Container, _Compare>;
-  
-template<class _InputIterator, 
-         class _Compare   = less<typename iterator_traits<_InputIterator>::value_type>,
-         class _Container = vector<typename iterator_traits<_InputIterator>::value_type>,
-         class = typename enable_if< __is_input_iterator<_InputIterator>::value, nullptr_t>::type,
-         class = typename enable_if<!__is_allocator<_Compare>::value, nullptr_t>::type,
-         class = typename enable_if<!__is_allocator<_Container>::value, nullptr_t>::type
->
-priority_queue(_InputIterator, _InputIterator, _Compare = _Compare(), _Container = _Container())
-    -> priority_queue<typename iterator_traits<_InputIterator>::value_type, _Container, _Compare>;
-  
-template<class _Compare, 
-         class _Container,
-         class _Alloc,
-         class = typename enable_if<!__is_allocator<_Compare>::value, nullptr_t>::type,
-         class = typename enable_if<!__is_allocator<_Container>::value, nullptr_t>::type,
-         class = typename enable_if< __is_allocator<_Alloc>::value, nullptr_t>::type
->
-priority_queue(_Compare, _Container, _Alloc)
-    -> priority_queue<typename _Container::value_type, _Container, _Compare>;
-#endif
-
-template <class _Tp, class _Container, class _Compare>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(const _Compare& __comp,
-                                                          const container_type& __c)
-    : c(__c),
-      comp(__comp)
-{
-    _VSTD::make_heap(c.begin(), c.end(), comp);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Container, class _Compare>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
-                                                          container_type&& __c)
-    : c(_VSTD::move(__c)),
-      comp(__comp)
-{
-    _VSTD::make_heap(c.begin(), c.end(), comp);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Container, class _Compare>
-template <class _InputIter>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(_InputIter __f, _InputIter __l,
-                                                          const value_compare& __comp)
-    : c(__f, __l),
-      comp(__comp)
-{
-    _VSTD::make_heap(c.begin(), c.end(), comp);
-}
-
-template <class _Tp, class _Container, class _Compare>
-template <class _InputIter>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(_InputIter __f, _InputIter __l,
-                                                          const value_compare& __comp,
-                                                          const container_type& __c)
-    : c(__c),
-      comp(__comp)
-{
-    c.insert(c.end(), __f, __l);
-    _VSTD::make_heap(c.begin(), c.end(), comp);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Container, class _Compare>
-template <class _InputIter>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(_InputIter __f, _InputIter __l,
-                                                          const value_compare& __comp,
-                                                          container_type&& __c)
-    : c(_VSTD::move(__c)),
-      comp(__comp)
-{
-    c.insert(c.end(), __f, __l);
-    _VSTD::make_heap(c.begin(), c.end(), comp);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Container, class _Compare>
-template <class _Alloc>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type*)
-    : c(__a)
-{
-}
-
-template <class _Tp, class _Container, class _Compare>
-template <class _Alloc>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
-                                                          const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type*)
-    : c(__a),
-      comp(__comp)
-{
-}
-
-template <class _Tp, class _Container, class _Compare>
-template <class _Alloc>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
-                                                          const container_type& __c,
-                                                          const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type*)
-    : c(__c, __a),
-      comp(__comp)
-{
-    _VSTD::make_heap(c.begin(), c.end(), comp);
-}
-
-template <class _Tp, class _Container, class _Compare>
-template <class _Alloc>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(const priority_queue& __q,
-                                                          const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type*)
-    : c(__q.c, __a),
-      comp(__q.comp)
-{
-    _VSTD::make_heap(c.begin(), c.end(), comp);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Container, class _Compare>
-template <class _Alloc>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(const value_compare& __comp,
-                                                          container_type&& __c,
-                                                          const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type*)
-    : c(_VSTD::move(__c), __a),
-      comp(__comp)
-{
-    _VSTD::make_heap(c.begin(), c.end(), comp);
-}
-
-template <class _Tp, class _Container, class _Compare>
-template <class _Alloc>
-inline
-priority_queue<_Tp, _Container, _Compare>::priority_queue(priority_queue&& __q,
-                                                          const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type*)
-    : c(_VSTD::move(__q.c), __a),
-      comp(_VSTD::move(__q.comp))
-{
-    _VSTD::make_heap(c.begin(), c.end(), comp);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Container, class _Compare>
-inline
-void
-priority_queue<_Tp, _Container, _Compare>::push(const value_type& __v)
-{
-    c.push_back(__v);
-    _VSTD::push_heap(c.begin(), c.end(), comp);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Container, class _Compare>
-inline
-void
-priority_queue<_Tp, _Container, _Compare>::push(value_type&& __v)
-{
-    c.push_back(_VSTD::move(__v));
-    _VSTD::push_heap(c.begin(), c.end(), comp);
-}
-
-template <class _Tp, class _Container, class _Compare>
-template <class... _Args>
-inline
-void
-priority_queue<_Tp, _Container, _Compare>::emplace(_Args&&... __args)
-{
-    c.emplace_back(_VSTD::forward<_Args>(__args)...);
-    _VSTD::push_heap(c.begin(), c.end(), comp);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Container, class _Compare>
-inline
-void
-priority_queue<_Tp, _Container, _Compare>::pop()
-{
-    _VSTD::pop_heap(c.begin(), c.end(), comp);
-    c.pop_back();
-}
-
-template <class _Tp, class _Container, class _Compare>
-inline
-void
-priority_queue<_Tp, _Container, _Compare>::swap(priority_queue& __q)
-        _NOEXCEPT_(__is_nothrow_swappable<container_type>::value &&
-                   __is_nothrow_swappable<value_compare>::value)
-{
-    using _VSTD::swap;
-    swap(c, __q.c);
-    swap(comp, __q.comp);
-}
-
-template <class _Tp, class _Container, class _Compare>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if<
-    __is_swappable<_Container>::value
-    && __is_swappable<_Compare>::value,
-    void
->::type
-swap(priority_queue<_Tp, _Container, _Compare>& __x,
-     priority_queue<_Tp, _Container, _Compare>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-template <class _Tp, class _Container, class _Compare, class _Alloc>
-struct _LIBCPP_TEMPLATE_VIS uses_allocator<priority_queue<_Tp, _Container, _Compare>, _Alloc>
-    : public uses_allocator<_Container, _Alloc>
-{
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_QUEUE
diff --git a/lib/libcxx/include/random b/lib/libcxx/include/random
deleted file mode 100644
index 724bd0fc215..00000000000
--- a/lib/libcxx/include/random
+++ /dev/null
@@ -1,6744 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- random -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_RANDOM
-#define _LIBCPP_RANDOM
-
-/*
-    random synopsis
-
-#include <initializer_list>
-
-namespace std
-{
-
-// Engines
-
-template <class UIntType, UIntType a, UIntType c, UIntType m>
-class linear_congruential_engine
-{
-public:
-    // types
-    typedef UIntType result_type;
-
-    // engine characteristics
-    static constexpr result_type multiplier = a;
-    static constexpr result_type increment = c;
-    static constexpr result_type modulus = m;
-    static constexpr result_type min() { return c == 0u ? 1u: 0u;}
-    static constexpr result_type max() { return m - 1u;}
-    static constexpr result_type default_seed = 1u;
-
-    // constructors and seeding functions
-    explicit linear_congruential_engine(result_type s = default_seed);
-    template<class Sseq> explicit linear_congruential_engine(Sseq& q);
-    void seed(result_type s = default_seed);
-    template<class Sseq> void seed(Sseq& q);
-
-    // generating functions
-    result_type operator()();
-    void discard(unsigned long long z);
-};
-
-template <class UIntType, UIntType a, UIntType c, UIntType m>
-bool
-operator==(const linear_congruential_engine<UIntType, a, c, m>& x,
-           const linear_congruential_engine<UIntType, a, c, m>& y);
-
-template <class UIntType, UIntType a, UIntType c, UIntType m>
-bool
-operator!=(const linear_congruential_engine<UIntType, a, c, m>& x,
-           const linear_congruential_engine<UIntType, a, c, m>& y);
-
-template <class charT, class traits,
-          class UIntType, UIntType a, UIntType c, UIntType m>
-basic_ostream<charT, traits>&
-operator<<(basic_ostream<charT, traits>& os,
-           const linear_congruential_engine<UIntType, a, c, m>& x);
-
-template <class charT, class traits,
-          class UIntType, UIntType a, UIntType c, UIntType m>
-basic_istream<charT, traits>&
-operator>>(basic_istream<charT, traits>& is,
-           linear_congruential_engine<UIntType, a, c, m>& x);
-
-template <class UIntType, size_t w, size_t n, size_t m, size_t r,
-          UIntType a, size_t u, UIntType d, size_t s,
-          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
-class mersenne_twister_engine
-{
-public:
-    // types
-    typedef UIntType result_type;
-
-    // engine characteristics
-    static constexpr size_t word_size = w;
-    static constexpr size_t state_size = n;
-    static constexpr size_t shift_size = m;
-    static constexpr size_t mask_bits = r;
-    static constexpr result_type xor_mask = a;
-    static constexpr size_t tempering_u = u;
-    static constexpr result_type tempering_d = d;
-    static constexpr size_t tempering_s = s;
-    static constexpr result_type tempering_b = b;
-    static constexpr size_t tempering_t = t;
-    static constexpr result_type tempering_c = c;
-    static constexpr size_t tempering_l = l;
-    static constexpr result_type initialization_multiplier = f;
-    static constexpr result_type min () { return 0; }
-    static constexpr result_type max() { return 2^w - 1; }
-    static constexpr result_type default_seed = 5489u;
-
-    // constructors and seeding functions
-    explicit mersenne_twister_engine(result_type value = default_seed);
-    template<class Sseq> explicit mersenne_twister_engine(Sseq& q);
-    void seed(result_type value = default_seed);
-    template<class Sseq> void seed(Sseq& q);
-
-    // generating functions
-    result_type operator()();
-    void discard(unsigned long long z);
-};
-
-template <class UIntType, size_t w, size_t n, size_t m, size_t r,
-          UIntType a, size_t u, UIntType d, size_t s,
-          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
-bool
-operator==(
-    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x,
-    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& y);
-
-template <class UIntType, size_t w, size_t n, size_t m, size_t r,
-          UIntType a, size_t u, UIntType d, size_t s,
-          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
-bool
-operator!=(
-    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x,
-    const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& y);
-
-template <class charT, class traits,
-          class UIntType, size_t w, size_t n, size_t m, size_t r,
-          UIntType a, size_t u, UIntType d, size_t s,
-          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
-basic_ostream<charT, traits>&
-operator<<(basic_ostream<charT, traits>& os,
-           const mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x);
-
-template <class charT, class traits,
-          class UIntType, size_t w, size_t n, size_t m, size_t r,
-          UIntType a, size_t u, UIntType d, size_t s,
-          UIntType b, size_t t, UIntType c, size_t l, UIntType f>
-basic_istream<charT, traits>&
-operator>>(basic_istream<charT, traits>& is,
-           mersenne_twister_engine<UIntType, w, n, m, r, a, u, d, s, b, t, c, l, f>& x);
-
-template<class UIntType, size_t w, size_t s, size_t r>
-class subtract_with_carry_engine
-{
-public:
-    // types
-    typedef UIntType result_type;
-
-    // engine characteristics
-    static constexpr size_t word_size = w;
-    static constexpr size_t short_lag = s;
-    static constexpr size_t long_lag = r;
-    static constexpr result_type min() { return 0; }
-    static constexpr result_type max() { return m-1; }
-    static constexpr result_type default_seed = 19780503u;
-
-    // constructors and seeding functions
-    explicit subtract_with_carry_engine(result_type value = default_seed);
-    template<class Sseq> explicit subtract_with_carry_engine(Sseq& q);
-    void seed(result_type value = default_seed);
-    template<class Sseq> void seed(Sseq& q);
-
-    // generating functions
-    result_type operator()();
-    void discard(unsigned long long z);
-};
-
-template<class UIntType, size_t w, size_t s, size_t r>
-bool
-operator==(
-    const subtract_with_carry_engine<UIntType, w, s, r>& x,
-    const subtract_with_carry_engine<UIntType, w, s, r>& y);
-
-template<class UIntType, size_t w, size_t s, size_t r>
-bool
-operator!=(
-    const subtract_with_carry_engine<UIntType, w, s, r>& x,
-    const subtract_with_carry_engine<UIntType, w, s, r>& y);
-
-template <class charT, class traits,
-          class UIntType, size_t w, size_t s, size_t r>
-basic_ostream<charT, traits>&
-operator<<(basic_ostream<charT, traits>& os,
-           const subtract_with_carry_engine<UIntType, w, s, r>& x);
-
-template <class charT, class traits,
-          class UIntType, size_t w, size_t s, size_t r>
-basic_istream<charT, traits>&
-operator>>(basic_istream<charT, traits>& is,
-           subtract_with_carry_engine<UIntType, w, s, r>& x);
-
-template<class Engine, size_t p, size_t r>
-class discard_block_engine
-{
-public:
-    // types
-    typedef typename Engine::result_type result_type;
-
-    // engine characteristics
-    static constexpr size_t block_size = p;
-    static constexpr size_t used_block = r;
-    static constexpr result_type min() { return Engine::min(); }
-    static constexpr result_type max() { return Engine::max(); }
-
-    // constructors and seeding functions
-    discard_block_engine();
-    explicit discard_block_engine(const Engine& e);
-    explicit discard_block_engine(Engine&& e);
-    explicit discard_block_engine(result_type s);
-    template<class Sseq> explicit discard_block_engine(Sseq& q);
-    void seed();
-    void seed(result_type s);
-    template<class Sseq> void seed(Sseq& q);
-
-    // generating functions
-    result_type operator()();
-    void discard(unsigned long long z);
-
-    // property functions
-    const Engine& base() const noexcept;
-};
-
-template<class Engine, size_t p, size_t r>
-bool
-operator==(
-    const discard_block_engine<Engine, p, r>& x,
-    const discard_block_engine<Engine, p, r>& y);
-
-template<class Engine, size_t p, size_t r>
-bool
-operator!=(
-    const discard_block_engine<Engine, p, r>& x,
-    const discard_block_engine<Engine, p, r>& y);
-
-template <class charT, class traits,
-          class Engine, size_t p, size_t r>
-basic_ostream<charT, traits>&
-operator<<(basic_ostream<charT, traits>& os,
-           const discard_block_engine<Engine, p, r>& x);
-
-template <class charT, class traits,
-          class Engine, size_t p, size_t r>
-basic_istream<charT, traits>&
-operator>>(basic_istream<charT, traits>& is,
-           discard_block_engine<Engine, p, r>& x);
-
-template<class Engine, size_t w, class UIntType>
-class independent_bits_engine
-{
-public:
-    // types
-    typedef UIntType result_type;
-
-    // engine characteristics
-    static constexpr result_type min() { return 0; }
-    static constexpr result_type max() { return 2^w - 1; }
-
-    // constructors and seeding functions
-    independent_bits_engine();
-    explicit independent_bits_engine(const Engine& e);
-    explicit independent_bits_engine(Engine&& e);
-    explicit independent_bits_engine(result_type s);
-    template<class Sseq> explicit independent_bits_engine(Sseq& q);
-    void seed();
-    void seed(result_type s);
-    template<class Sseq> void seed(Sseq& q);
-
-    // generating functions
-    result_type operator()(); void discard(unsigned long long z);
-
-    // property functions
-    const Engine& base() const noexcept;
-};
-
-template<class Engine, size_t w, class UIntType>
-bool
-operator==(
-    const independent_bits_engine<Engine, w, UIntType>& x,
-    const independent_bits_engine<Engine, w, UIntType>& y);
-
-template<class Engine, size_t w, class UIntType>
-bool
-operator!=(
-    const independent_bits_engine<Engine, w, UIntType>& x,
-    const independent_bits_engine<Engine, w, UIntType>& y);
-
-template <class charT, class traits,
-          class Engine, size_t w, class UIntType>
-basic_ostream<charT, traits>&
-operator<<(basic_ostream<charT, traits>& os,
-           const independent_bits_engine<Engine, w, UIntType>& x);
-
-template <class charT, class traits,
-          class Engine, size_t w, class UIntType>
-basic_istream<charT, traits>&
-operator>>(basic_istream<charT, traits>& is,
-           independent_bits_engine<Engine, w, UIntType>& x);
-
-template<class Engine, size_t k>
-class shuffle_order_engine
-{
-public:
-    // types
-    typedef typename Engine::result_type result_type;
-
-    // engine characteristics
-    static constexpr size_t table_size = k;
-    static constexpr result_type min() { return Engine::min; }
-    static constexpr result_type max() { return Engine::max; }
-
-    // constructors and seeding functions
-    shuffle_order_engine();
-    explicit shuffle_order_engine(const Engine& e);
-    explicit shuffle_order_engine(Engine&& e);
-    explicit shuffle_order_engine(result_type s);
-    template<class Sseq> explicit shuffle_order_engine(Sseq& q);
-    void seed();
-    void seed(result_type s);
-    template<class Sseq> void seed(Sseq& q);
-
-    // generating functions
-    result_type operator()();
-    void discard(unsigned long long z);
-
-    // property functions
-    const Engine& base() const noexcept;
-};
-
-template<class Engine, size_t k>
-bool
-operator==(
-    const shuffle_order_engine<Engine, k>& x,
-    const shuffle_order_engine<Engine, k>& y);
-
-template<class Engine, size_t k>
-bool
-operator!=(
-    const shuffle_order_engine<Engine, k>& x,
-    const shuffle_order_engine<Engine, k>& y);
-
-template <class charT, class traits,
-          class Engine, size_t k>
-basic_ostream<charT, traits>&
-operator<<(basic_ostream<charT, traits>& os,
-           const shuffle_order_engine<Engine, k>& x);
-
-template <class charT, class traits,
-          class Engine, size_t k>
-basic_istream<charT, traits>&
-operator>>(basic_istream<charT, traits>& is,
-           shuffle_order_engine<Engine, k>& x);
-
-typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647>
-                                                                   minstd_rand0;
-typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647>
-                                                                    minstd_rand;
-typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
-                                0x9908b0df,
-                                11, 0xffffffff,
-                                7,  0x9d2c5680,
-                                15, 0xefc60000,
-                                18, 1812433253>                         mt19937;
-typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
-                                0xb5026f5aa96619e9,
-                                29, 0x5555555555555555,
-                                17, 0x71d67fffeda60000,
-                                37, 0xfff7eee000000000,
-                                43, 6364136223846793005>             mt19937_64;
-typedef subtract_with_carry_engine<uint_fast32_t, 24, 10, 24>     ranlux24_base;
-typedef subtract_with_carry_engine<uint_fast64_t, 48,  5, 12>     ranlux48_base;
-typedef discard_block_engine<ranlux24_base, 223, 23>                   ranlux24;
-typedef discard_block_engine<ranlux48_base, 389, 11>                   ranlux48;
-typedef shuffle_order_engine<minstd_rand0, 256>                         knuth_b;
-typedef minstd_rand                                       default_random_engine;
-
-// Generators
-
-class random_device
-{
-public:
-    // types
-    typedef unsigned int result_type;
-
-    // generator characteristics
-    static constexpr result_type min() { return numeric_limits<result_type>::min(); }
-    static constexpr result_type max() { return numeric_limits<result_type>::max(); }
-
-    // constructors
-    explicit random_device(const string& token = "/dev/urandom");
-
-    // generating functions
-    result_type operator()();
-
-    // property functions
-    double entropy() const noexcept;
-
-    // no copy functions
-    random_device(const random_device& ) = delete;
-    void operator=(const random_device& ) = delete;
-};
-
-// Utilities
-
-class seed_seq
-{
-public:
-    // types
-    typedef uint_least32_t result_type;
-
-    // constructors
-    seed_seq();
-    template<class T>
-        seed_seq(initializer_list<T> il);
-    template<class InputIterator>
-        seed_seq(InputIterator begin, InputIterator end);
-
-    // generating functions
-    template<class RandomAccessIterator>
-        void generate(RandomAccessIterator begin, RandomAccessIterator end);
-
-    // property functions
-    size_t size() const;
-    template<class OutputIterator>
-        void param(OutputIterator dest) const;
-
-    // no copy functions
-    seed_seq(const seed_seq&) = delete;
-    void operator=(const seed_seq& ) = delete;
-};
-
-template<class RealType, size_t bits, class URNG>
-    RealType generate_canonical(URNG& g);
-
-// Distributions
-
-template<class IntType = int>
-class uniform_int_distribution
-{
-public:
-    // types
-    typedef IntType result_type;
-
-    class param_type
-    {
-    public:
-        typedef uniform_int_distribution distribution_type;
-
-        explicit param_type(IntType a = 0,
-                                    IntType b = numeric_limits<IntType>::max());
-
-        result_type a() const;
-        result_type b() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructors and reset functions
-    explicit uniform_int_distribution(IntType a = 0,
-                                    IntType b = numeric_limits<IntType>::max());
-    explicit uniform_int_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type a() const;
-    result_type b() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const uniform_int_distribution& x,
-                           const uniform_int_distribution& y);
-    friend bool operator!=(const uniform_int_distribution& x,
-                           const uniform_int_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const uniform_int_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               uniform_int_distribution& x);
-};
-
-template<class RealType = double>
-class uniform_real_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef uniform_real_distribution distribution_type;
-
-        explicit param_type(RealType a = 0,
-                            RealType b = 1);
-
-        result_type a() const;
-        result_type b() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructors and reset functions
-    explicit uniform_real_distribution(RealType a = 0.0, RealType b = 1.0);
-    explicit uniform_real_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type a() const;
-    result_type b() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const uniform_real_distribution& x,
-                           const uniform_real_distribution& y);
-    friend bool operator!=(const uniform_real_distribution& x,
-                           const uniform_real_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const uniform_real_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               uniform_real_distribution& x);
-};
-
-class bernoulli_distribution
-{
-public:
-    // types
-    typedef bool result_type;
-
-    class param_type
-    {
-    public:
-        typedef bernoulli_distribution distribution_type;
-
-        explicit param_type(double p = 0.5);
-
-        double p() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructors and reset functions
-    explicit bernoulli_distribution(double p = 0.5);
-    explicit bernoulli_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    double p() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const bernoulli_distribution& x,
-                           const bernoulli_distribution& y);
-    friend bool operator!=(const bernoulli_distribution& x,
-                           const bernoulli_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const bernoulli_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               bernoulli_distribution& x);
-};
-
-template<class IntType = int>
-class binomial_distribution
-{
-public:
-    // types
-    typedef IntType result_type;
-
-    class param_type
-    {
-    public:
-        typedef binomial_distribution distribution_type;
-
-        explicit param_type(IntType t = 1, double p = 0.5);
-
-        IntType t() const;
-        double p() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructors and reset functions
-    explicit binomial_distribution(IntType t = 1, double p = 0.5);
-    explicit binomial_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    IntType t() const;
-    double p() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const binomial_distribution& x,
-                           const binomial_distribution& y);
-    friend bool operator!=(const binomial_distribution& x,
-                           const binomial_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const binomial_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               binomial_distribution& x);
-};
-
-template<class IntType = int>
-class geometric_distribution
-{
-public:
-    // types
-    typedef IntType result_type;
-
-    class param_type
-    {
-    public:
-        typedef geometric_distribution distribution_type;
-
-        explicit param_type(double p = 0.5);
-
-        double p() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructors and reset functions
-    explicit geometric_distribution(double p = 0.5);
-    explicit geometric_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    double p() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const geometric_distribution& x,
-                           const geometric_distribution& y);
-    friend bool operator!=(const geometric_distribution& x,
-                           const geometric_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const geometric_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               geometric_distribution& x);
-};
-
-template<class IntType = int>
-class negative_binomial_distribution
-{
-public:
-    // types
-    typedef IntType result_type;
-
-    class param_type
-    {
-    public:
-        typedef negative_binomial_distribution distribution_type;
-
-        explicit param_type(result_type k = 1, double p = 0.5);
-
-        result_type k() const;
-        double p() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    explicit negative_binomial_distribution(result_type k = 1, double p = 0.5);
-    explicit negative_binomial_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type k() const;
-    double p() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const negative_binomial_distribution& x,
-                           const negative_binomial_distribution& y);
-    friend bool operator!=(const negative_binomial_distribution& x,
-                           const negative_binomial_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const negative_binomial_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               negative_binomial_distribution& x);
-};
-
-template<class IntType = int>
-class poisson_distribution
-{
-public:
-    // types
-    typedef IntType result_type;
-
-    class param_type
-    {
-    public:
-        typedef poisson_distribution distribution_type;
-
-        explicit param_type(double mean = 1.0);
-
-        double mean() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructors and reset functions
-    explicit poisson_distribution(double mean = 1.0);
-    explicit poisson_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    double mean() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const poisson_distribution& x,
-                           const poisson_distribution& y);
-    friend bool operator!=(const poisson_distribution& x,
-                           const poisson_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const poisson_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               poisson_distribution& x);
-};
-
-template<class RealType = double>
-class exponential_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef exponential_distribution distribution_type;
-
-        explicit param_type(result_type lambda = 1.0);
-
-        result_type lambda() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructors and reset functions
-    explicit exponential_distribution(result_type lambda = 1.0);
-    explicit exponential_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type lambda() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const exponential_distribution& x,
-                           const exponential_distribution& y);
-    friend bool operator!=(const exponential_distribution& x,
-                           const exponential_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const exponential_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               exponential_distribution& x);
-};
-
-template<class RealType = double>
-class gamma_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef gamma_distribution distribution_type;
-
-        explicit param_type(result_type alpha = 1, result_type beta = 1);
-
-        result_type alpha() const;
-        result_type beta() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructors and reset functions
-    explicit gamma_distribution(result_type alpha = 1, result_type beta = 1);
-    explicit gamma_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type alpha() const;
-    result_type beta() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const gamma_distribution& x,
-                           const gamma_distribution& y);
-    friend bool operator!=(const gamma_distribution& x,
-                           const gamma_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const gamma_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               gamma_distribution& x);
-};
-
-template<class RealType = double>
-class weibull_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef weibull_distribution distribution_type;
-
-        explicit param_type(result_type alpha = 1, result_type beta = 1);
-
-        result_type a() const;
-        result_type b() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    explicit weibull_distribution(result_type a = 1, result_type b = 1);
-    explicit weibull_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type a() const;
-    result_type b() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const weibull_distribution& x,
-                           const weibull_distribution& y);
-    friend bool operator!=(const weibull_distribution& x,
-                           const weibull_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const weibull_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               weibull_distribution& x);
-};
-
-template<class RealType = double>
-class extreme_value_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef extreme_value_distribution distribution_type;
-
-        explicit param_type(result_type a = 0, result_type b = 1);
-
-        result_type a() const;
-        result_type b() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    explicit extreme_value_distribution(result_type a = 0, result_type b = 1);
-    explicit extreme_value_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type a() const;
-    result_type b() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const extreme_value_distribution& x,
-                           const extreme_value_distribution& y);
-    friend bool operator!=(const extreme_value_distribution& x,
-                           const extreme_value_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const extreme_value_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               extreme_value_distribution& x);
-};
-
-template<class RealType = double>
-class normal_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef normal_distribution distribution_type;
-
-        explicit param_type(result_type mean = 0, result_type stddev = 1);
-
-        result_type mean() const;
-        result_type stddev() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructors and reset functions
-    explicit normal_distribution(result_type mean = 0, result_type stddev = 1);
-    explicit normal_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type mean() const;
-    result_type stddev() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const normal_distribution& x,
-                           const normal_distribution& y);
-    friend bool operator!=(const normal_distribution& x,
-                           const normal_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const normal_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               normal_distribution& x);
-};
-
-template<class RealType = double>
-class lognormal_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef lognormal_distribution distribution_type;
-
-        explicit param_type(result_type m = 0, result_type s = 1);
-
-        result_type m() const;
-        result_type s() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    explicit lognormal_distribution(result_type m = 0, result_type s = 1);
-    explicit lognormal_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type m() const;
-    result_type s() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const lognormal_distribution& x,
-                           const lognormal_distribution& y);
-    friend bool operator!=(const lognormal_distribution& x,
-                           const lognormal_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const lognormal_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               lognormal_distribution& x);
-};
-
-template<class RealType = double>
-class chi_squared_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef chi_squared_distribution distribution_type;
-
-        explicit param_type(result_type n = 1);
-
-        result_type n() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    explicit chi_squared_distribution(result_type n = 1);
-    explicit chi_squared_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type n() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const chi_squared_distribution& x,
-                           const chi_squared_distribution& y);
-    friend bool operator!=(const chi_squared_distribution& x,
-                           const chi_squared_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const chi_squared_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               chi_squared_distribution& x);
-};
-
-template<class RealType = double>
-class cauchy_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef cauchy_distribution distribution_type;
-
-        explicit param_type(result_type a = 0, result_type b = 1);
-
-        result_type a() const;
-        result_type b() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    explicit cauchy_distribution(result_type a = 0, result_type b = 1);
-    explicit cauchy_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type a() const;
-    result_type b() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const cauchy_distribution& x,
-                           const cauchy_distribution& y);
-    friend bool operator!=(const cauchy_distribution& x,
-                           const cauchy_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const cauchy_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               cauchy_distribution& x);
-};
-
-template<class RealType = double>
-class fisher_f_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef fisher_f_distribution distribution_type;
-
-        explicit param_type(result_type m = 1, result_type n = 1);
-
-        result_type m() const;
-        result_type n() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    explicit fisher_f_distribution(result_type m = 1, result_type n = 1);
-    explicit fisher_f_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type m() const;
-    result_type n() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const fisher_f_distribution& x,
-                           const fisher_f_distribution& y);
-    friend bool operator!=(const fisher_f_distribution& x,
-                           const fisher_f_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const fisher_f_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               fisher_f_distribution& x);
-};
-
-template<class RealType = double>
-class student_t_distribution
-{
-public:
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef student_t_distribution distribution_type;
-
-        explicit param_type(result_type n = 1);
-
-        result_type n() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    explicit student_t_distribution(result_type n = 1);
-    explicit student_t_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    result_type n() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const student_t_distribution& x,
-                           const student_t_distribution& y);
-    friend bool operator!=(const student_t_distribution& x,
-                           const student_t_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const student_t_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               student_t_distribution& x);
-};
-
-template<class IntType = int>
-class discrete_distribution
-{
-public:
-    // types
-    typedef IntType result_type;
-
-    class param_type
-    {
-    public:
-        typedef discrete_distribution distribution_type;
-
-        param_type();
-        template<class InputIterator>
-            param_type(InputIterator firstW, InputIterator lastW);
-        param_type(initializer_list<double> wl);
-        template<class UnaryOperation>
-            param_type(size_t nw, double xmin, double xmax, UnaryOperation fw);
-
-        vector<double> probabilities() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    discrete_distribution();
-    template<class InputIterator>
-        discrete_distribution(InputIterator firstW, InputIterator lastW);
-    discrete_distribution(initializer_list<double> wl);
-    template<class UnaryOperation>
-        discrete_distribution(size_t nw, double xmin, double xmax,
-                              UnaryOperation fw);
-    explicit discrete_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    vector<double> probabilities() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const discrete_distribution& x,
-                           const discrete_distribution& y);
-    friend bool operator!=(const discrete_distribution& x,
-                           const discrete_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const discrete_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               discrete_distribution& x);
-};
-
-template<class RealType = double>
-class piecewise_constant_distribution
-{
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef piecewise_constant_distribution distribution_type;
-
-        param_type();
-        template<class InputIteratorB, class InputIteratorW>
-            param_type(InputIteratorB firstB, InputIteratorB lastB,
-                       InputIteratorW firstW);
-        template<class UnaryOperation>
-            param_type(initializer_list<result_type> bl, UnaryOperation fw);
-        template<class UnaryOperation>
-            param_type(size_t nw, result_type xmin, result_type xmax,
-                       UnaryOperation fw);
-
-        vector<result_type> intervals() const;
-        vector<result_type> densities() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    piecewise_constant_distribution();
-    template<class InputIteratorB, class InputIteratorW>
-        piecewise_constant_distribution(InputIteratorB firstB,
-                                        InputIteratorB lastB,
-                                        InputIteratorW firstW);
-    template<class UnaryOperation>
-        piecewise_constant_distribution(initializer_list<result_type> bl,
-                                        UnaryOperation fw);
-    template<class UnaryOperation>
-        piecewise_constant_distribution(size_t nw, result_type xmin,
-                                        result_type xmax, UnaryOperation fw);
-    explicit piecewise_constant_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    vector<result_type> intervals() const;
-    vector<result_type> densities() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const piecewise_constant_distribution& x,
-                           const piecewise_constant_distribution& y);
-    friend bool operator!=(const piecewise_constant_distribution& x,
-                           const piecewise_constant_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const piecewise_constant_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               piecewise_constant_distribution& x);
-};
-
-template<class RealType = double>
-class piecewise_linear_distribution
-{
-    // types
-    typedef RealType result_type;
-
-    class param_type
-    {
-    public:
-        typedef piecewise_linear_distribution distribution_type;
-
-        param_type();
-        template<class InputIteratorB, class InputIteratorW>
-            param_type(InputIteratorB firstB, InputIteratorB lastB,
-                       InputIteratorW firstW);
-        template<class UnaryOperation>
-            param_type(initializer_list<result_type> bl, UnaryOperation fw);
-        template<class UnaryOperation>
-            param_type(size_t nw, result_type xmin, result_type xmax,
-                       UnaryOperation fw);
-
-        vector<result_type> intervals() const;
-        vector<result_type> densities() const;
-
-        friend bool operator==(const param_type& x, const param_type& y);
-        friend bool operator!=(const param_type& x, const param_type& y);
-    };
-
-    // constructor and reset functions
-    piecewise_linear_distribution();
-    template<class InputIteratorB, class InputIteratorW>
-        piecewise_linear_distribution(InputIteratorB firstB,
-                                      InputIteratorB lastB,
-                                      InputIteratorW firstW);
-
-    template<class UnaryOperation>
-        piecewise_linear_distribution(initializer_list<result_type> bl,
-                                      UnaryOperation fw);
-
-    template<class UnaryOperation>
-        piecewise_linear_distribution(size_t nw, result_type xmin,
-                                      result_type xmax, UnaryOperation fw);
-
-    explicit piecewise_linear_distribution(const param_type& parm);
-    void reset();
-
-    // generating functions
-    template<class URNG> result_type operator()(URNG& g);
-    template<class URNG> result_type operator()(URNG& g, const param_type& parm);
-
-    // property functions
-    vector<result_type> intervals() const;
-    vector<result_type> densities() const;
-
-    param_type param() const;
-    void param(const param_type& parm);
-
-    result_type min() const;
-    result_type max() const;
-
-    friend bool operator==(const piecewise_linear_distribution& x,
-                           const piecewise_linear_distribution& y);
-    friend bool operator!=(const piecewise_linear_distribution& x,
-                           const piecewise_linear_distribution& y);
-
-    template <class charT, class traits>
-    friend
-    basic_ostream<charT, traits>&
-    operator<<(basic_ostream<charT, traits>& os,
-               const piecewise_linear_distribution& x);
-
-    template <class charT, class traits>
-    friend
-    basic_istream<charT, traits>&
-    operator>>(basic_istream<charT, traits>& is,
-               piecewise_linear_distribution& x);
-};
-
-} // std
-*/
-
-#include <__config>
-#include <cstddef>
-#include <cstdint>
-#include <cmath>
-#include <type_traits>
-#include <initializer_list>
-#include <limits>
-#include <algorithm>
-#include <numeric>
-#include <vector>
-#include <string>
-#include <istream>
-#include <ostream>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// __is_seed_sequence
-
-template <class _Sseq, class _Engine>
-struct __is_seed_sequence
-{
-    static _LIBCPP_CONSTEXPR const bool value =
-              !is_convertible<_Sseq, typename _Engine::result_type>::value &&
-              !is_same<typename remove_cv<_Sseq>::type, _Engine>::value;
-};
-
-// linear_congruential_engine
-
-template <unsigned long long __a, unsigned long long __c,
-          unsigned long long __m, unsigned long long _Mp,
-          bool _MightOverflow = (__a != 0 && __m != 0 && __m-1 > (_Mp-__c)/__a)>
-struct __lce_ta;
-
-// 64
-
-template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
-struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), true>
-{
-    typedef unsigned long long result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type next(result_type __x)
-    {
-        // Schrage's algorithm
-        const result_type __q = __m / __a;
-        const result_type __r = __m % __a;
-        const result_type __t0 = __a * (__x % __q);
-        const result_type __t1 = __r * (__x / __q);
-        __x = __t0 + (__t0 < __t1) * __m - __t1;
-        __x += __c - (__x >= __m - __c) * __m;
-        return __x;
-    }
-};
-
-template <unsigned long long __a, unsigned long long __m>
-struct __lce_ta<__a, 0, __m, (unsigned long long)(~0), true>
-{
-    typedef unsigned long long result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type next(result_type __x)
-    {
-        // Schrage's algorithm
-        const result_type __q = __m / __a;
-        const result_type __r = __m % __a;
-        const result_type __t0 = __a * (__x % __q);
-        const result_type __t1 = __r * (__x / __q);
-        __x = __t0 + (__t0 < __t1) * __m - __t1;
-        return __x;
-    }
-};
-
-template <unsigned long long __a, unsigned long long __c, unsigned long long __m>
-struct __lce_ta<__a, __c, __m, (unsigned long long)(~0), false>
-{
-    typedef unsigned long long result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type next(result_type __x)
-    {
-        return (__a * __x + __c) % __m;
-    }
-};
-
-template <unsigned long long __a, unsigned long long __c>
-struct __lce_ta<__a, __c, 0, (unsigned long long)(~0), false>
-{
-    typedef unsigned long long result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type next(result_type __x)
-    {
-        return __a * __x + __c;
-    }
-};
-
-// 32
-
-template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
-struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), true>
-{
-    typedef unsigned result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type next(result_type __x)
-    {
-        const result_type __a = static_cast<result_type>(_Ap);
-        const result_type __c = static_cast<result_type>(_Cp);
-        const result_type __m = static_cast<result_type>(_Mp);
-        // Schrage's algorithm
-        const result_type __q = __m / __a;
-        const result_type __r = __m % __a;
-        const result_type __t0 = __a * (__x % __q);
-        const result_type __t1 = __r * (__x / __q);
-        __x = __t0 + (__t0 < __t1) * __m - __t1;
-        __x += __c - (__x >= __m - __c) * __m;
-        return __x;
-    }
-};
-
-template <unsigned long long _Ap, unsigned long long _Mp>
-struct __lce_ta<_Ap, 0, _Mp, unsigned(~0), true>
-{
-    typedef unsigned result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type next(result_type __x)
-    {
-        const result_type __a = static_cast<result_type>(_Ap);
-        const result_type __m = static_cast<result_type>(_Mp);
-        // Schrage's algorithm
-        const result_type __q = __m / __a;
-        const result_type __r = __m % __a;
-        const result_type __t0 = __a * (__x % __q);
-        const result_type __t1 = __r * (__x / __q);
-        __x = __t0 + (__t0 < __t1) * __m - __t1;
-        return __x;
-    }
-};
-
-template <unsigned long long _Ap, unsigned long long _Cp, unsigned long long _Mp>
-struct __lce_ta<_Ap, _Cp, _Mp, unsigned(~0), false>
-{
-    typedef unsigned result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type next(result_type __x)
-    {
-        const result_type __a = static_cast<result_type>(_Ap);
-        const result_type __c = static_cast<result_type>(_Cp);
-        const result_type __m = static_cast<result_type>(_Mp);
-        return (__a * __x + __c) % __m;
-    }
-};
-
-template <unsigned long long _Ap, unsigned long long _Cp>
-struct __lce_ta<_Ap, _Cp, 0, unsigned(~0), false>
-{
-    typedef unsigned result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type next(result_type __x)
-    {
-        const result_type __a = static_cast<result_type>(_Ap);
-        const result_type __c = static_cast<result_type>(_Cp);
-        return __a * __x + __c;
-    }
-};
-
-// 16
-
-template <unsigned long long __a, unsigned long long __c, unsigned long long __m, bool __b>
-struct __lce_ta<__a, __c, __m, (unsigned short)(~0), __b>
-{
-    typedef unsigned short result_type;
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type next(result_type __x)
-    {
-        return static_cast<result_type>(__lce_ta<__a, __c, __m, unsigned(~0)>::next(__x));
-    }
-};
-
-template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-class _LIBCPP_TEMPLATE_VIS linear_congruential_engine;
-
-template <class _CharT, class _Traits,
-          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
-_LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
-
-template <class _CharT, class _Traits,
-          class _Up, _Up _Ap, _Up _Cp, _Up _Np>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
-
-template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-class _LIBCPP_TEMPLATE_VIS linear_congruential_engine
-{
-public:
-    // types
-    typedef _UIntType result_type;
-
-private:
-    result_type __x_;
-
-    static _LIBCPP_CONSTEXPR const result_type _Mp = result_type(~0);
-
-    static_assert(__m == 0 || __a < __m, "linear_congruential_engine invalid parameters");
-    static_assert(__m == 0 || __c < __m, "linear_congruential_engine invalid parameters");
-public:
-    static _LIBCPP_CONSTEXPR const result_type _Min = __c == 0u ? 1u: 0u;
-    static _LIBCPP_CONSTEXPR const result_type _Max = __m - 1u;
-    static_assert(_Min < _Max,           "linear_congruential_engine invalid parameters");
-
-    // engine characteristics
-    static _LIBCPP_CONSTEXPR const result_type multiplier = __a;
-    static _LIBCPP_CONSTEXPR const result_type increment = __c;
-    static _LIBCPP_CONSTEXPR const result_type modulus = __m;
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type min() {return _Min;}
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type max() {return _Max;}
-    static _LIBCPP_CONSTEXPR const result_type default_seed = 1u;
-
-    // constructors and seeding functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit linear_congruential_engine(result_type __s = default_seed)
-        {seed(__s);}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit linear_congruential_engine(_Sseq& __q,
-        typename enable_if<__is_seed_sequence<_Sseq, linear_congruential_engine>::value>::type* = 0)
-        {seed(__q);}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed(result_type __s = default_seed)
-        {seed(integral_constant<bool, __m == 0>(),
-              integral_constant<bool, __c == 0>(), __s);}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __is_seed_sequence<_Sseq, linear_congruential_engine>::value,
-            void
-        >::type
-        seed(_Sseq& __q)
-            {__seed(__q, integral_constant<unsigned,
-                1 + (__m == 0 ? (sizeof(result_type) * __CHAR_BIT__ - 1)/32
-                             :  (__m > 0x100000000ull))>());}
-
-    // generating functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator()()
-        {return __x_ = static_cast<result_type>(__lce_ta<__a, __c, __m, _Mp>::next(__x_));}
-    _LIBCPP_INLINE_VISIBILITY
-    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const linear_congruential_engine& __x,
-                    const linear_congruential_engine& __y)
-        {return __x.__x_ == __y.__x_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const linear_congruential_engine& __x,
-                    const linear_congruential_engine& __y)
-        {return !(__x == __y);}
-
-private:
-
-    _LIBCPP_INLINE_VISIBILITY
-    void seed(true_type, true_type, result_type __s) {__x_ = __s == 0 ? 1 : __s;}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed(true_type, false_type, result_type __s) {__x_ = __s;}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed(false_type, true_type, result_type __s) {__x_ = __s % __m == 0 ?
-                                                                 1 : __s % __m;}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed(false_type, false_type, result_type __s) {__x_ = __s % __m;}
-
-    template<class _Sseq>
-        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
-    template<class _Sseq>
-        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
-
-    template <class _CharT, class _Traits,
-              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const linear_congruential_engine<_Up, _Ap, _Cp, _Np>&);
-
-    template <class _CharT, class _Traits,
-              class _Up, _Up _Ap, _Up _Cp, _Up _Np>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               linear_congruential_engine<_Up, _Ap, _Cp, _Np>& __x);
-};
-
-template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
-    linear_congruential_engine<_UIntType, __a, __c, __m>::multiplier;
-
-template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
-    linear_congruential_engine<_UIntType, __a, __c, __m>::increment;
-
-template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
-    linear_congruential_engine<_UIntType, __a, __c, __m>::modulus;
-
-template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-    _LIBCPP_CONSTEXPR const typename linear_congruential_engine<_UIntType, __a, __c, __m>::result_type
-    linear_congruential_engine<_UIntType, __a, __c, __m>::default_seed;
-
-template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-template<class _Sseq>
-void
-linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
-                                                 integral_constant<unsigned, 1>)
-{
-    const unsigned __k = 1;
-    uint32_t __ar[__k+3];
-    __q.generate(__ar, __ar + __k + 3);
-    result_type __s = static_cast<result_type>(__ar[3] % __m);
-    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
-}
-
-template <class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-template<class _Sseq>
-void
-linear_congruential_engine<_UIntType, __a, __c, __m>::__seed(_Sseq& __q,
-                                                 integral_constant<unsigned, 2>)
-{
-    const unsigned __k = 2;
-    uint32_t __ar[__k+3];
-    __q.generate(__ar, __ar + __k + 3);
-    result_type __s = static_cast<result_type>((__ar[3] +
-                                              ((uint64_t)__ar[4] << 32)) % __m);
-    __x_ = __c == 0 && __s == 0 ? result_type(1) : __s;
-}
-
-template <class _CharT, class _Traits,
-          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left);
-    __os.fill(__os.widen(' '));
-    return __os << __x.__x_;
-}
-
-template <class _CharT, class _Traits,
-          class _UIntType, _UIntType __a, _UIntType __c, _UIntType __m>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           linear_congruential_engine<_UIntType, __a, __c, __m>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    _UIntType __t;
-    __is >> __t;
-    if (!__is.fail())
-        __x.__x_ = __t;
-    return __is;
-}
-
-typedef linear_congruential_engine<uint_fast32_t, 16807, 0, 2147483647>
-                                                                   minstd_rand0;
-typedef linear_congruential_engine<uint_fast32_t, 48271, 0, 2147483647>
-                                                                    minstd_rand;
-typedef minstd_rand                                       default_random_engine;
-// mersenne_twister_engine
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine;
-
-template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-bool
-operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
-           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
-
-template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
-           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
-
-template <class _CharT, class _Traits,
-          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
-
-template <class _CharT, class _Traits,
-          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-class _LIBCPP_TEMPLATE_VIS mersenne_twister_engine
-{
-public:
-    // types
-    typedef _UIntType result_type;
-
-private:
-    result_type __x_[__n];
-    size_t      __i_;
-
-    static_assert(  0 <  __m, "mersenne_twister_engine invalid parameters");
-    static_assert(__m <= __n, "mersenne_twister_engine invalid parameters");
-    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
-    static_assert(__w <= _Dt, "mersenne_twister_engine invalid parameters");
-    static_assert(  2 <= __w, "mersenne_twister_engine invalid parameters");
-    static_assert(__r <= __w, "mersenne_twister_engine invalid parameters");
-    static_assert(__u <= __w, "mersenne_twister_engine invalid parameters");
-    static_assert(__s <= __w, "mersenne_twister_engine invalid parameters");
-    static_assert(__t <= __w, "mersenne_twister_engine invalid parameters");
-    static_assert(__l <= __w, "mersenne_twister_engine invalid parameters");
-public:
-    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
-    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
-                                                      (result_type(1) << __w) - result_type(1);
-    static_assert(_Min < _Max, "mersenne_twister_engine invalid parameters");
-    static_assert(__a <= _Max, "mersenne_twister_engine invalid parameters");
-    static_assert(__b <= _Max, "mersenne_twister_engine invalid parameters");
-    static_assert(__c <= _Max, "mersenne_twister_engine invalid parameters");
-    static_assert(__d <= _Max, "mersenne_twister_engine invalid parameters");
-    static_assert(__f <= _Max, "mersenne_twister_engine invalid parameters");
-
-    // engine characteristics
-    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
-    static _LIBCPP_CONSTEXPR const size_t state_size = __n;
-    static _LIBCPP_CONSTEXPR const size_t shift_size = __m;
-    static _LIBCPP_CONSTEXPR const size_t mask_bits = __r;
-    static _LIBCPP_CONSTEXPR const result_type xor_mask = __a;
-    static _LIBCPP_CONSTEXPR const size_t tempering_u = __u;
-    static _LIBCPP_CONSTEXPR const result_type tempering_d = __d;
-    static _LIBCPP_CONSTEXPR const size_t tempering_s = __s;
-    static _LIBCPP_CONSTEXPR const result_type tempering_b = __b;
-    static _LIBCPP_CONSTEXPR const size_t tempering_t = __t;
-    static _LIBCPP_CONSTEXPR const result_type tempering_c = __c;
-    static _LIBCPP_CONSTEXPR const size_t tempering_l = __l;
-    static _LIBCPP_CONSTEXPR const result_type initialization_multiplier = __f;
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
-    static _LIBCPP_CONSTEXPR const result_type default_seed = 5489u;
-
-    // constructors and seeding functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit mersenne_twister_engine(result_type __sd = default_seed)
-        {seed(__sd);}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit mersenne_twister_engine(_Sseq& __q,
-        typename enable_if<__is_seed_sequence<_Sseq, mersenne_twister_engine>::value>::type* = 0)
-        {seed(__q);}
-    void seed(result_type __sd = default_seed);
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __is_seed_sequence<_Sseq, mersenne_twister_engine>::value,
-            void
-        >::type
-        seed(_Sseq& __q)
-            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
-
-    // generating functions
-    result_type operator()();
-    _LIBCPP_INLINE_VISIBILITY
-    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
-
-    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-    friend
-    bool
-    operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
-               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
-
-    template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-    friend
-    bool
-    operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
-               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __y);
-
-    template <class _CharT, class _Traits,
-              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                             _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
-
-    template <class _CharT, class _Traits,
-              class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-              _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-              _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                       _Bp, _Tp, _Cp, _Lp, _Fp>& __x);
-private:
-
-    template<class _Sseq>
-        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
-    template<class _Sseq>
-        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
-
-    template <size_t __count>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        typename enable_if
-        <
-            __count < __w,
-            result_type
-        >::type
-        __lshift(result_type __x) {return (__x << __count) & _Max;}
-
-    template <size_t __count>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        typename enable_if
-        <
-            (__count >= __w),
-            result_type
-        >::type
-        __lshift(result_type) {return result_type(0);}
-
-    template <size_t __count>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        typename enable_if
-        <
-            __count < _Dt,
-            result_type
-        >::type
-        __rshift(result_type __x) {return __x >> __count;}
-
-    template <size_t __count>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        typename enable_if
-        <
-            (__count >= _Dt),
-            result_type
-        >::type
-        __rshift(result_type) {return result_type(0);}
-};
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const size_t
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::word_size;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const size_t 
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::state_size;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const size_t 
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::shift_size;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const size_t 
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::mask_bits;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::xor_mask;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const size_t 
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_u;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_d;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const size_t 
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_s;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_b;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const size_t 
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_t;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_c;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const size_t 
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::tempering_l;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::initialization_multiplier;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-    _LIBCPP_CONSTEXPR const typename mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::result_type
-    mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b, __t, __c, __l, __f>::default_seed;
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-void
-mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
-    __t, __c, __l, __f>::seed(result_type __sd)
-    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-{   // __w >= 2
-    __x_[0] = __sd & _Max;
-    for (size_t __i = 1; __i < __n; ++__i)
-        __x_[__i] = (__f * (__x_[__i-1] ^ __rshift<__w - 2>(__x_[__i-1])) + __i) & _Max;
-    __i_ = 0;
-}
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-template<class _Sseq>
-void
-mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
-    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 1>)
-{
-    const unsigned __k = 1;
-    uint32_t __ar[__n * __k];
-    __q.generate(__ar, __ar + __n * __k);
-    for (size_t __i = 0; __i < __n; ++__i)
-        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
-    const result_type __mask = __r == _Dt ? result_type(~0) :
-                                       (result_type(1) << __r) - result_type(1);
-    __i_ = 0;
-    if ((__x_[0] & ~__mask) == 0)
-    {
-        for (size_t __i = 1; __i < __n; ++__i)
-            if (__x_[__i] != 0)
-                return;
-        __x_[0] = result_type(1) << (__w - 1);
-    }
-}
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-template<class _Sseq>
-void
-mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
-    __t, __c, __l, __f>::__seed(_Sseq& __q, integral_constant<unsigned, 2>)
-{
-    const unsigned __k = 2;
-    uint32_t __ar[__n * __k];
-    __q.generate(__ar, __ar + __n * __k);
-    for (size_t __i = 0; __i < __n; ++__i)
-        __x_[__i] = static_cast<result_type>(
-            (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
-    const result_type __mask = __r == _Dt ? result_type(~0) :
-                                       (result_type(1) << __r) - result_type(1);
-    __i_ = 0;
-    if ((__x_[0] & ~__mask) == 0)
-    {
-        for (size_t __i = 1; __i < __n; ++__i)
-            if (__x_[__i] != 0)
-                return;
-        __x_[0] = result_type(1) << (__w - 1);
-    }
-}
-
-template <class _UIntType, size_t __w, size_t __n, size_t __m, size_t __r,
-          _UIntType __a, size_t __u, _UIntType __d, size_t __s,
-          _UIntType __b, size_t __t, _UIntType __c, size_t __l, _UIntType __f>
-_UIntType
-mersenne_twister_engine<_UIntType, __w, __n, __m, __r, __a, __u, __d, __s, __b,
-    __t, __c, __l, __f>::operator()()
-{
-    const size_t __j = (__i_ + 1) % __n;
-    const result_type __mask = __r == _Dt ? result_type(~0) :
-                                       (result_type(1) << __r) - result_type(1);
-    const result_type _Yp = (__x_[__i_] & ~__mask) | (__x_[__j] & __mask);
-    const size_t __k = (__i_ + __m) % __n;
-    __x_[__i_] = __x_[__k] ^ __rshift<1>(_Yp) ^ (__a * (_Yp & 1));
-    result_type __z = __x_[__i_] ^ (__rshift<__u>(__x_[__i_]) & __d);
-    __i_ = __j;
-    __z ^= __lshift<__s>(__z) & __b;
-    __z ^= __lshift<__t>(__z) & __c;
-    return __z ^ __rshift<__l>(__z);
-}
-
-template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-bool
-operator==(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
-           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
-{
-    if (__x.__i_ == __y.__i_)
-        return _VSTD::equal(__x.__x_, __x.__x_ + _Np, __y.__x_);
-    if (__x.__i_ == 0 || __y.__i_ == 0)
-    {
-        size_t __j = _VSTD::min(_Np - __x.__i_, _Np - __y.__i_);
-        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
-                         __y.__x_ + __y.__i_))
-            return false;
-        if (__x.__i_ == 0)
-            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Np, __y.__x_);
-        return _VSTD::equal(__x.__x_, __x.__x_ + (_Np - __j), __y.__x_ + __j);
-    }
-    if (__x.__i_ < __y.__i_)
-    {
-        size_t __j = _Np - __y.__i_;
-        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
-                         __y.__x_ + __y.__i_))
-            return false;
-        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Np,
-                         __y.__x_))
-            return false;
-        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
-                           __y.__x_ + (_Np - (__x.__i_ + __j)));
-    }
-    size_t __j = _Np - __x.__i_;
-    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
-                     __x.__x_ + __x.__i_))
-        return false;
-    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Np,
-                     __x.__x_))
-        return false;
-    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
-                       __x.__x_ + (_Np - (__y.__i_ + __j)));
-}
-
-template <class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x,
-           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _CharT, class _Traits,
-          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                         _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    __os << __x.__x_[__x.__i_];
-    for (size_t __j = __x.__i_ + 1; __j < _Np; ++__j)
-        __os << __sp << __x.__x_[__j];
-    for (size_t __j = 0; __j < __x.__i_; ++__j)
-        __os << __sp << __x.__x_[__j];
-    return __os;
-}
-
-template <class _CharT, class _Traits,
-          class _UInt, size_t _Wp, size_t _Np, size_t _Mp, size_t _Rp,
-          _UInt _Ap, size_t _Up, _UInt _Dp, size_t _Sp,
-          _UInt _Bp, size_t _Tp, _UInt _Cp, size_t _Lp, _UInt _Fp>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           mersenne_twister_engine<_UInt, _Wp, _Np, _Mp, _Rp, _Ap, _Up, _Dp, _Sp,
-                                   _Bp, _Tp, _Cp, _Lp, _Fp>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    _UInt __t[_Np];
-    for (size_t __i = 0; __i < _Np; ++__i)
-        __is >> __t[__i];
-    if (!__is.fail())
-    {
-        for (size_t __i = 0; __i < _Np; ++__i)
-            __x.__x_[__i] = __t[__i];
-        __x.__i_ = 0;
-    }
-    return __is;
-}
-
-typedef mersenne_twister_engine<uint_fast32_t, 32, 624, 397, 31,
-                                0x9908b0df, 11, 0xffffffff,
-                                7,  0x9d2c5680,
-                                15, 0xefc60000,
-                                18, 1812433253>                         mt19937;
-typedef mersenne_twister_engine<uint_fast64_t, 64, 312, 156, 31,
-                                0xb5026f5aa96619e9ULL, 29, 0x5555555555555555ULL,
-                                17, 0x71d67fffeda60000ULL,
-                                37, 0xfff7eee000000000ULL,
-                                43, 6364136223846793005ULL>          mt19937_64;
-
-// subtract_with_carry_engine
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine;
-
-template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-bool
-operator==(
-    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
-    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
-
-template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-_LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(
-    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
-    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
-
-template <class _CharT, class _Traits,
-          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
-
-template <class _CharT, class _Traits,
-          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-class _LIBCPP_TEMPLATE_VIS subtract_with_carry_engine
-{
-public:
-    // types
-    typedef _UIntType result_type;
-
-private:
-    result_type __x_[__r];
-    result_type  __c_;
-    size_t      __i_;
-
-    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
-    static_assert(  0 <  __w, "subtract_with_carry_engine invalid parameters");
-    static_assert(__w <= _Dt, "subtract_with_carry_engine invalid parameters");
-    static_assert(  0 <  __s, "subtract_with_carry_engine invalid parameters");
-    static_assert(__s <  __r, "subtract_with_carry_engine invalid parameters");
-public:
-    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
-    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
-                                                      (result_type(1) << __w) - result_type(1);
-    static_assert(_Min < _Max, "subtract_with_carry_engine invalid parameters");
-
-    // engine characteristics
-    static _LIBCPP_CONSTEXPR const size_t word_size = __w;
-    static _LIBCPP_CONSTEXPR const size_t short_lag = __s;
-    static _LIBCPP_CONSTEXPR const size_t long_lag = __r;
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
-    static _LIBCPP_CONSTEXPR const result_type default_seed = 19780503u;
-
-    // constructors and seeding functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit subtract_with_carry_engine(result_type __sd = default_seed)
-        {seed(__sd);}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit subtract_with_carry_engine(_Sseq& __q,
-        typename enable_if<__is_seed_sequence<_Sseq, subtract_with_carry_engine>::value>::type* = 0)
-        {seed(__q);}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed(result_type __sd = default_seed)
-        {seed(__sd, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __is_seed_sequence<_Sseq, subtract_with_carry_engine>::value,
-            void
-        >::type
-        seed(_Sseq& __q)
-            {__seed(__q, integral_constant<unsigned, 1 + (__w - 1) / 32>());}
-
-    // generating functions
-    result_type operator()();
-    _LIBCPP_INLINE_VISIBILITY
-    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
-
-    template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-    friend
-    bool
-    operator==(
-        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
-        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
-
-    template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-    friend
-    bool
-    operator!=(
-        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
-        const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y);
-
-    template <class _CharT, class _Traits,
-              class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
-
-    template <class _CharT, class _Traits,
-              class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x);
-
-private:
-
-    void seed(result_type __sd, integral_constant<unsigned, 1>);
-    void seed(result_type __sd, integral_constant<unsigned, 2>);
-    template<class _Sseq>
-        void __seed(_Sseq& __q, integral_constant<unsigned, 1>);
-    template<class _Sseq>
-        void __seed(_Sseq& __q, integral_constant<unsigned, 2>);
-};
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::word_size;
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::short_lag;
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-    _LIBCPP_CONSTEXPR const size_t subtract_with_carry_engine<_UIntType, __w, __s, __r>::long_lag;
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-    _LIBCPP_CONSTEXPR const typename subtract_with_carry_engine<_UIntType, __w, __s, __r>::result_type
-    subtract_with_carry_engine<_UIntType, __w, __s, __r>::default_seed;
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-void
-subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
-        integral_constant<unsigned, 1>)
-{
-    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
-        __e(__sd == 0u ? default_seed : __sd);
-    for (size_t __i = 0; __i < __r; ++__i)
-        __x_[__i] = static_cast<result_type>(__e() & _Max);
-    __c_ = __x_[__r-1] == 0;
-    __i_ = 0;
-}
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-void
-subtract_with_carry_engine<_UIntType, __w, __s, __r>::seed(result_type __sd,
-        integral_constant<unsigned, 2>)
-{
-    linear_congruential_engine<result_type, 40014u, 0u, 2147483563u>
-        __e(__sd == 0u ? default_seed : __sd);
-    for (size_t __i = 0; __i < __r; ++__i)
-    {
-        result_type __e0 = __e();
-        __x_[__i] = static_cast<result_type>(
-                                    (__e0 + ((uint64_t)__e() << 32)) & _Max);
-    }
-    __c_ = __x_[__r-1] == 0;
-    __i_ = 0;
-}
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-template<class _Sseq>
-void
-subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
-        integral_constant<unsigned, 1>)
-{
-    const unsigned __k = 1;
-    uint32_t __ar[__r * __k];
-    __q.generate(__ar, __ar + __r * __k);
-    for (size_t __i = 0; __i < __r; ++__i)
-        __x_[__i] = static_cast<result_type>(__ar[__i] & _Max);
-    __c_ = __x_[__r-1] == 0;
-    __i_ = 0;
-}
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-template<class _Sseq>
-void
-subtract_with_carry_engine<_UIntType, __w, __s, __r>::__seed(_Sseq& __q,
-        integral_constant<unsigned, 2>)
-{
-    const unsigned __k = 2;
-    uint32_t __ar[__r * __k];
-    __q.generate(__ar, __ar + __r * __k);
-    for (size_t __i = 0; __i < __r; ++__i)
-        __x_[__i] = static_cast<result_type>(
-                  (__ar[2 * __i] + ((uint64_t)__ar[2 * __i + 1] << 32)) & _Max);
-    __c_ = __x_[__r-1] == 0;
-    __i_ = 0;
-}
-
-template<class _UIntType, size_t __w, size_t __s, size_t __r>
-_UIntType
-subtract_with_carry_engine<_UIntType, __w, __s, __r>::operator()()
-{
-    const result_type& __xs = __x_[(__i_ + (__r - __s)) % __r];
-    result_type& __xr = __x_[__i_];
-    result_type __new_c = __c_ == 0 ? __xs < __xr : __xs != 0 ? __xs <= __xr : 1;
-    __xr = (__xs - __xr - __c_) & _Max;
-    __c_ = __new_c;
-    __i_ = (__i_ + 1) % __r;
-    return __xr;
-}
-
-template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-bool
-operator==(
-    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
-    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
-{
-    if (__x.__c_ != __y.__c_)
-        return false;
-    if (__x.__i_ == __y.__i_)
-        return _VSTD::equal(__x.__x_, __x.__x_ + _Rp, __y.__x_);
-    if (__x.__i_ == 0 || __y.__i_ == 0)
-    {
-        size_t __j = _VSTD::min(_Rp - __x.__i_, _Rp - __y.__i_);
-        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + __x.__i_ + __j,
-                         __y.__x_ + __y.__i_))
-            return false;
-        if (__x.__i_ == 0)
-            return _VSTD::equal(__x.__x_ + __j, __x.__x_ + _Rp, __y.__x_);
-        return _VSTD::equal(__x.__x_, __x.__x_ + (_Rp - __j), __y.__x_ + __j);
-    }
-    if (__x.__i_ < __y.__i_)
-    {
-        size_t __j = _Rp - __y.__i_;
-        if (!_VSTD::equal(__x.__x_ + __x.__i_, __x.__x_ + (__x.__i_ + __j),
-                         __y.__x_ + __y.__i_))
-            return false;
-        if (!_VSTD::equal(__x.__x_ + (__x.__i_ + __j), __x.__x_ + _Rp,
-                         __y.__x_))
-            return false;
-        return _VSTD::equal(__x.__x_, __x.__x_ + __x.__i_,
-                           __y.__x_ + (_Rp - (__x.__i_ + __j)));
-    }
-    size_t __j = _Rp - __x.__i_;
-    if (!_VSTD::equal(__y.__x_ + __y.__i_, __y.__x_ + (__y.__i_ + __j),
-                     __x.__x_ + __x.__i_))
-        return false;
-    if (!_VSTD::equal(__y.__x_ + (__y.__i_ + __j), __y.__x_ + _Rp,
-                     __x.__x_))
-        return false;
-    return _VSTD::equal(__y.__x_, __y.__x_ + __y.__i_,
-                       __x.__x_ + (_Rp - (__y.__i_ + __j)));
-}
-
-template<class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(
-    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x,
-    const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _CharT, class _Traits,
-          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    __os << __x.__x_[__x.__i_];
-    for (size_t __j = __x.__i_ + 1; __j < _Rp; ++__j)
-        __os << __sp << __x.__x_[__j];
-    for (size_t __j = 0; __j < __x.__i_; ++__j)
-        __os << __sp << __x.__x_[__j];
-    __os << __sp << __x.__c_;
-    return __os;
-}
-
-template <class _CharT, class _Traits,
-          class _UInt, size_t _Wp, size_t _Sp, size_t _Rp>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           subtract_with_carry_engine<_UInt, _Wp, _Sp, _Rp>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    _UInt __t[_Rp+1];
-    for (size_t __i = 0; __i < _Rp+1; ++__i)
-        __is >> __t[__i];
-    if (!__is.fail())
-    {
-        for (size_t __i = 0; __i < _Rp; ++__i)
-            __x.__x_[__i] = __t[__i];
-        __x.__c_ = __t[_Rp];
-        __x.__i_ = 0;
-    }
-    return __is;
-}
-
-typedef subtract_with_carry_engine<uint_fast32_t, 24, 10, 24>     ranlux24_base;
-typedef subtract_with_carry_engine<uint_fast64_t, 48,  5, 12>     ranlux48_base;
-
-// discard_block_engine
-
-template<class _Engine, size_t __p, size_t __r>
-class _LIBCPP_TEMPLATE_VIS discard_block_engine
-{
-    _Engine __e_;
-    int     __n_;
-
-    static_assert(  0 <  __r, "discard_block_engine invalid parameters");
-    static_assert(__r <= __p, "discard_block_engine invalid parameters");
-    static_assert(__r <= INT_MAX, "discard_block_engine invalid parameters");
-public:
-    // types
-    typedef typename _Engine::result_type result_type;
-
-    // engine characteristics
-    static _LIBCPP_CONSTEXPR const size_t block_size = __p;
-    static _LIBCPP_CONSTEXPR const size_t used_block = __r;
-
-#ifdef _LIBCPP_CXX03_LANG
-    static const result_type _Min = _Engine::_Min;
-    static const result_type _Max = _Engine::_Max;
-#else
-    static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();
-    static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type min() { return _Engine::min(); }
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type max() { return _Engine::max(); }
-
-    // constructors and seeding functions
-    _LIBCPP_INLINE_VISIBILITY
-    discard_block_engine() : __n_(0) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit discard_block_engine(const _Engine& __e)
-        : __e_(__e), __n_(0) {}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    explicit discard_block_engine(_Engine&& __e)
-        : __e_(_VSTD::move(__e)), __n_(0) {}
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    explicit discard_block_engine(result_type __sd) : __e_(__sd), __n_(0) {}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit discard_block_engine(_Sseq& __q,
-        typename enable_if<__is_seed_sequence<_Sseq, discard_block_engine>::value &&
-                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
-        : __e_(__q), __n_(0) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed() {__e_.seed(); __n_ = 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed(result_type __sd) {__e_.seed(__sd); __n_ = 0;}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __is_seed_sequence<_Sseq, discard_block_engine>::value,
-            void
-        >::type
-        seed(_Sseq& __q) {__e_.seed(__q); __n_ = 0;}
-
-    // generating functions
-    result_type operator()();
-    _LIBCPP_INLINE_VISIBILITY
-    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    const _Engine& base() const _NOEXCEPT {return __e_;}
-
-    template<class _Eng, size_t _Pp, size_t _Rp>
-    friend
-    bool
-    operator==(
-        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
-        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
-
-    template<class _Eng, size_t _Pp, size_t _Rp>
-    friend
-    bool
-    operator!=(
-        const discard_block_engine<_Eng, _Pp, _Rp>& __x,
-        const discard_block_engine<_Eng, _Pp, _Rp>& __y);
-
-    template <class _CharT, class _Traits,
-              class _Eng, size_t _Pp, size_t _Rp>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const discard_block_engine<_Eng, _Pp, _Rp>& __x);
-
-    template <class _CharT, class _Traits,
-              class _Eng, size_t _Pp, size_t _Rp>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               discard_block_engine<_Eng, _Pp, _Rp>& __x);
-};
-
-template<class _Engine, size_t __p, size_t __r>
-    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::block_size;
-
-template<class _Engine, size_t __p, size_t __r>
-    _LIBCPP_CONSTEXPR const size_t discard_block_engine<_Engine, __p, __r>::used_block;
-
-template<class _Engine, size_t __p, size_t __r>
-typename discard_block_engine<_Engine, __p, __r>::result_type
-discard_block_engine<_Engine, __p, __r>::operator()()
-{
-    if (__n_ >= static_cast<int>(__r))
-    {
-        __e_.discard(__p - __r);
-        __n_ = 0;
-    }
-    ++__n_;
-    return __e_();
-}
-
-template<class _Eng, size_t _Pp, size_t _Rp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
-           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
-{
-    return __x.__n_ == __y.__n_ && __x.__e_ == __y.__e_;
-}
-
-template<class _Eng, size_t _Pp, size_t _Rp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const discard_block_engine<_Eng, _Pp, _Rp>& __x,
-           const discard_block_engine<_Eng, _Pp, _Rp>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _CharT, class _Traits,
-          class _Eng, size_t _Pp, size_t _Rp>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const discard_block_engine<_Eng, _Pp, _Rp>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    return __os << __x.__e_ << __sp << __x.__n_;
-}
-
-template <class _CharT, class _Traits,
-          class _Eng, size_t _Pp, size_t _Rp>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           discard_block_engine<_Eng, _Pp, _Rp>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    _Eng __e;
-    int __n;
-    __is >> __e >> __n;
-    if (!__is.fail())
-    {
-        __x.__e_ = __e;
-        __x.__n_ = __n;
-    }
-    return __is;
-}
-
-typedef discard_block_engine<ranlux24_base, 223, 23> ranlux24;
-typedef discard_block_engine<ranlux48_base, 389, 11> ranlux48;
-
-// independent_bits_engine
-
-template<class _Engine, size_t __w, class _UIntType>
-class _LIBCPP_TEMPLATE_VIS independent_bits_engine
-{
-    template <class _UInt, _UInt _R0, size_t _Wp, size_t _Mp>
-    class __get_n
-    {
-        static _LIBCPP_CONSTEXPR const size_t _Dt = numeric_limits<_UInt>::digits;
-        static _LIBCPP_CONSTEXPR const size_t _Np = _Wp / _Mp + (_Wp % _Mp != 0);
-        static _LIBCPP_CONSTEXPR const size_t _W0 = _Wp / _Np;
-        static _LIBCPP_CONSTEXPR const _UInt _Y0 = _W0 >= _Dt ? 0 : (_R0 >> _W0) << _W0;
-    public:
-        static _LIBCPP_CONSTEXPR const size_t value = _R0 - _Y0 > _Y0 / _Np ? _Np + 1 : _Np;
-    };
-public:
-    // types
-    typedef _UIntType result_type;
-
-private:
-    _Engine __e_;
-
-    static _LIBCPP_CONSTEXPR const result_type _Dt = numeric_limits<result_type>::digits;
-    static_assert(  0 <  __w, "independent_bits_engine invalid parameters");
-    static_assert(__w <= _Dt, "independent_bits_engine invalid parameters");
-
-    typedef typename _Engine::result_type _Engine_result_type;
-    typedef typename conditional
-        <
-            sizeof(_Engine_result_type) <= sizeof(result_type),
-                result_type,
-                _Engine_result_type
-        >::type _Working_result_type;
-#ifdef _LIBCPP_CXX03_LANG
-    static const _Working_result_type _Rp = _Engine::_Max - _Engine::_Min
-                                          + _Working_result_type(1);
-#else
-    static _LIBCPP_CONSTEXPR const _Working_result_type _Rp = _Engine::max() - _Engine::min()
-                                                            + _Working_result_type(1);
-#endif
-    static _LIBCPP_CONSTEXPR const size_t __m = __log2<_Working_result_type, _Rp>::value;
-    static _LIBCPP_CONSTEXPR const size_t __n = __get_n<_Working_result_type, _Rp, __w, __m>::value;
-    static _LIBCPP_CONSTEXPR const size_t __w0 = __w / __n;
-    static _LIBCPP_CONSTEXPR const size_t __n0 = __n - __w % __n;
-    static _LIBCPP_CONSTEXPR const size_t _WDt = numeric_limits<_Working_result_type>::digits;
-    static _LIBCPP_CONSTEXPR const size_t _EDt = numeric_limits<_Engine_result_type>::digits;
-    static _LIBCPP_CONSTEXPR const _Working_result_type __y0 = __w0 >= _WDt ? 0 :
-                                                               (_Rp >> __w0) << __w0;
-    static _LIBCPP_CONSTEXPR const _Working_result_type __y1 = __w0 >= _WDt - 1 ? 0 :
-                                                               (_Rp >> (__w0+1)) << (__w0+1);
-    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask0 = __w0 > 0 ?
-                                _Engine_result_type(~0) >> (_EDt - __w0) :
-                                _Engine_result_type(0);
-    static _LIBCPP_CONSTEXPR const _Engine_result_type __mask1 = __w0 < _EDt - 1 ?
-                                _Engine_result_type(~0) >> (_EDt - (__w0 + 1)) :
-                                _Engine_result_type(~0);
-public:
-    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
-    static _LIBCPP_CONSTEXPR const result_type _Max = __w == _Dt ? result_type(~0) :
-                                                      (result_type(1) << __w) - result_type(1);
-    static_assert(_Min < _Max, "independent_bits_engine invalid parameters");
-
-    // engine characteristics
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
-
-    // constructors and seeding functions
-    _LIBCPP_INLINE_VISIBILITY
-    independent_bits_engine() {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit independent_bits_engine(const _Engine& __e)
-        : __e_(__e) {}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    explicit independent_bits_engine(_Engine&& __e)
-        : __e_(_VSTD::move(__e)) {}
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    explicit independent_bits_engine(result_type __sd) : __e_(__sd) {}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit independent_bits_engine(_Sseq& __q,
-        typename enable_if<__is_seed_sequence<_Sseq, independent_bits_engine>::value &&
-                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
-         : __e_(__q) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed() {__e_.seed();}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed(result_type __sd) {__e_.seed(__sd);}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __is_seed_sequence<_Sseq, independent_bits_engine>::value,
-            void
-        >::type
-        seed(_Sseq& __q) {__e_.seed(__q);}
-
-    // generating functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
-    _LIBCPP_INLINE_VISIBILITY
-    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    const _Engine& base() const _NOEXCEPT {return __e_;}
-
-    template<class _Eng, size_t _Wp, class _UInt>
-    friend
-    bool
-    operator==(
-        const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
-        const independent_bits_engine<_Eng, _Wp, _UInt>& __y);
-
-    template<class _Eng, size_t _Wp, class _UInt>
-    friend
-    bool
-    operator!=(
-        const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
-        const independent_bits_engine<_Eng, _Wp, _UInt>& __y);
-
-    template <class _CharT, class _Traits,
-              class _Eng, size_t _Wp, class _UInt>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const independent_bits_engine<_Eng, _Wp, _UInt>& __x);
-
-    template <class _CharT, class _Traits,
-              class _Eng, size_t _Wp, class _UInt>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               independent_bits_engine<_Eng, _Wp, _UInt>& __x);
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    result_type __eval(false_type);
-    result_type __eval(true_type);
-
-    template <size_t __count>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        typename enable_if
-        <
-            __count < _Dt,
-            result_type
-        >::type
-        __lshift(result_type __x) {return __x << __count;}
-
-    template <size_t __count>
-        _LIBCPP_INLINE_VISIBILITY
-        static
-        typename enable_if
-        <
-            (__count >= _Dt),
-            result_type
-        >::type
-        __lshift(result_type) {return result_type(0);}
-};
-
-template<class _Engine, size_t __w, class _UIntType>
-inline
-_UIntType
-independent_bits_engine<_Engine, __w, _UIntType>::__eval(false_type)
-{
-    return static_cast<result_type>(__e_() & __mask0);
-}
-
-template<class _Engine, size_t __w, class _UIntType>
-_UIntType
-independent_bits_engine<_Engine, __w, _UIntType>::__eval(true_type)
-{
-    result_type _Sp = 0;
-    for (size_t __k = 0; __k < __n0; ++__k)
-    {
-        _Engine_result_type __u;
-        do
-        {
-            __u = __e_() - _Engine::min();
-        } while (__u >= __y0);
-        _Sp = static_cast<result_type>(__lshift<__w0>(_Sp) + (__u & __mask0));
-    }
-    for (size_t __k = __n0; __k < __n; ++__k)
-    {
-        _Engine_result_type __u;
-        do
-        {
-            __u = __e_() - _Engine::min();
-        } while (__u >= __y1);
-        _Sp = static_cast<result_type>(__lshift<__w0+1>(_Sp) + (__u & __mask1));
-    }
-    return _Sp;
-}
-
-template<class _Eng, size_t _Wp, class _UInt>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(
-    const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
-    const independent_bits_engine<_Eng, _Wp, _UInt>& __y)
-{
-    return __x.base() == __y.base();
-}
-
-template<class _Eng, size_t _Wp, class _UInt>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(
-    const independent_bits_engine<_Eng, _Wp, _UInt>& __x,
-    const independent_bits_engine<_Eng, _Wp, _UInt>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _CharT, class _Traits,
-          class _Eng, size_t _Wp, class _UInt>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const independent_bits_engine<_Eng, _Wp, _UInt>& __x)
-{
-    return __os << __x.base();
-}
-
-template <class _CharT, class _Traits,
-          class _Eng, size_t _Wp, class _UInt>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           independent_bits_engine<_Eng, _Wp, _UInt>& __x)
-{
-    _Eng __e;
-    __is >> __e;
-    if (!__is.fail())
-        __x.__e_ = __e;
-    return __is;
-}
-
-// shuffle_order_engine
-
-template <uint64_t _Xp, uint64_t _Yp>
-struct __ugcd
-{
-    static _LIBCPP_CONSTEXPR const uint64_t value = __ugcd<_Yp, _Xp % _Yp>::value;
-};
-
-template <uint64_t _Xp>
-struct __ugcd<_Xp, 0>
-{
-    static _LIBCPP_CONSTEXPR const uint64_t value = _Xp;
-};
-
-template <uint64_t _Np, uint64_t _Dp>
-class __uratio
-{
-    static_assert(_Dp != 0, "__uratio divide by 0");
-    static _LIBCPP_CONSTEXPR const uint64_t __gcd = __ugcd<_Np, _Dp>::value;
-public:
-    static _LIBCPP_CONSTEXPR const uint64_t num = _Np / __gcd;
-    static _LIBCPP_CONSTEXPR const uint64_t den = _Dp / __gcd;
-
-    typedef __uratio<num, den> type;
-};
-
-template<class _Engine, size_t __k>
-class _LIBCPP_TEMPLATE_VIS shuffle_order_engine
-{
-    static_assert(0 < __k, "shuffle_order_engine invalid parameters");
-public:
-    // types
-    typedef typename _Engine::result_type result_type;
-
-private:
-    _Engine __e_;
-    result_type _V_[__k];
-    result_type _Y_;
-
-public:
-    // engine characteristics
-    static _LIBCPP_CONSTEXPR const size_t table_size = __k;
-
-#ifdef _LIBCPP_CXX03_LANG
-    static const result_type _Min = _Engine::_Min;
-    static const result_type _Max = _Engine::_Max;
-#else
-    static _LIBCPP_CONSTEXPR const result_type _Min = _Engine::min();
-    static _LIBCPP_CONSTEXPR const result_type _Max = _Engine::max();
-#endif
-    static_assert(_Min < _Max, "shuffle_order_engine invalid parameters");
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type min() { return _Min; }
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type max() { return _Max; }
-
-    static _LIBCPP_CONSTEXPR const unsigned long long _Rp = _Max - _Min + 1ull;
-
-    // constructors and seeding functions
-    _LIBCPP_INLINE_VISIBILITY
-    shuffle_order_engine() {__init();}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit shuffle_order_engine(const _Engine& __e)
-        : __e_(__e) {__init();}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    explicit shuffle_order_engine(_Engine&& __e)
-        : __e_(_VSTD::move(__e)) {__init();}
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    explicit shuffle_order_engine(result_type __sd) : __e_(__sd) {__init();}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit shuffle_order_engine(_Sseq& __q,
-        typename enable_if<__is_seed_sequence<_Sseq, shuffle_order_engine>::value &&
-                           !is_convertible<_Sseq, _Engine>::value>::type* = 0)
-         : __e_(__q) {__init();}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed() {__e_.seed(); __init();}
-    _LIBCPP_INLINE_VISIBILITY
-    void seed(result_type __sd) {__e_.seed(__sd); __init();}
-    template<class _Sseq>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __is_seed_sequence<_Sseq, shuffle_order_engine>::value,
-            void
-        >::type
-        seed(_Sseq& __q) {__e_.seed(__q); __init();}
-
-    // generating functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator()() {return __eval(integral_constant<bool, _Rp != 0>());}
-    _LIBCPP_INLINE_VISIBILITY
-    void discard(unsigned long long __z) {for (; __z; --__z) operator()();}
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    const _Engine& base() const _NOEXCEPT {return __e_;}
-
-private:
-    template<class _Eng, size_t _Kp>
-    friend
-    bool
-    operator==(
-        const shuffle_order_engine<_Eng, _Kp>& __x,
-        const shuffle_order_engine<_Eng, _Kp>& __y);
-
-    template<class _Eng, size_t _Kp>
-    friend
-    bool
-    operator!=(
-        const shuffle_order_engine<_Eng, _Kp>& __x,
-        const shuffle_order_engine<_Eng, _Kp>& __y);
-
-    template <class _CharT, class _Traits,
-              class _Eng, size_t _Kp>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const shuffle_order_engine<_Eng, _Kp>& __x);
-
-    template <class _CharT, class _Traits,
-              class _Eng, size_t _Kp>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               shuffle_order_engine<_Eng, _Kp>& __x);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __init()
-    {
-        for (size_t __i = 0; __i < __k; ++__i)
-            _V_[__i] = __e_();
-        _Y_ = __e_();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type __eval(false_type) {return __eval2(integral_constant<bool, __k & 1>());}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type __eval(true_type) {return __eval(__uratio<__k, _Rp>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type __eval2(false_type) {return __eval(__uratio<__k/2, 0x8000000000000000ull>());}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type __eval2(true_type) {return __evalf<__k, 0>();}
-
-    template <uint64_t _Np, uint64_t _Dp>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            (__uratio<_Np, _Dp>::num > 0xFFFFFFFFFFFFFFFFull / (_Max - _Min)),
-            result_type
-        >::type
-        __eval(__uratio<_Np, _Dp>)
-            {return __evalf<__uratio<_Np, _Dp>::num, __uratio<_Np, _Dp>::den>();}
-
-    template <uint64_t _Np, uint64_t _Dp>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __uratio<_Np, _Dp>::num <= 0xFFFFFFFFFFFFFFFFull / (_Max - _Min),
-            result_type
-        >::type
-        __eval(__uratio<_Np, _Dp>)
-        {
-            const size_t __j = static_cast<size_t>(__uratio<_Np, _Dp>::num * (_Y_ - _Min)
-                                                   / __uratio<_Np, _Dp>::den);
-            _Y_ = _V_[__j];
-            _V_[__j] = __e_();
-            return _Y_;
-        }
-
-    template <uint64_t __n, uint64_t __d>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type __evalf()
-        {
-            const double _Fp = __d == 0 ?
-                __n / (2. * 0x8000000000000000ull) :
-                __n / (double)__d;
-            const size_t __j = static_cast<size_t>(_Fp * (_Y_ - _Min));
-            _Y_ = _V_[__j];
-            _V_[__j] = __e_();
-            return _Y_;
-        }
-};
-
-template<class _Engine, size_t __k>
-    _LIBCPP_CONSTEXPR const size_t shuffle_order_engine<_Engine, __k>::table_size;
-
-template<class _Eng, size_t _Kp>
-bool
-operator==(
-    const shuffle_order_engine<_Eng, _Kp>& __x,
-    const shuffle_order_engine<_Eng, _Kp>& __y)
-{
-    return __x._Y_ == __y._Y_ && _VSTD::equal(__x._V_, __x._V_ + _Kp, __y._V_) &&
-           __x.__e_ == __y.__e_;
-}
-
-template<class _Eng, size_t _Kp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(
-    const shuffle_order_engine<_Eng, _Kp>& __x,
-    const shuffle_order_engine<_Eng, _Kp>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _CharT, class _Traits,
-          class _Eng, size_t _Kp>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const shuffle_order_engine<_Eng, _Kp>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    __os << __x.__e_ << __sp << __x._V_[0];
-    for (size_t __i = 1; __i < _Kp; ++__i)
-        __os << __sp << __x._V_[__i];
-    return __os << __sp << __x._Y_;
-}
-
-template <class _CharT, class _Traits,
-          class _Eng, size_t _Kp>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           shuffle_order_engine<_Eng, _Kp>& __x)
-{
-    typedef typename shuffle_order_engine<_Eng, _Kp>::result_type result_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    _Eng __e;
-    result_type _Vp[_Kp+1];
-    __is >> __e;
-    for (size_t __i = 0; __i < _Kp+1; ++__i)
-        __is >> _Vp[__i];
-    if (!__is.fail())
-    {
-        __x.__e_ = __e;
-        for (size_t __i = 0; __i < _Kp; ++__i)
-            __x._V_[__i] = _Vp[__i];
-        __x._Y_ = _Vp[_Kp];
-    }
-    return __is;
-}
-
-typedef shuffle_order_engine<minstd_rand0, 256>                         knuth_b;
-
-// random_device
-
-class _LIBCPP_TYPE_VIS random_device
-{
-#ifdef _LIBCPP_USING_DEV_RANDOM
-    int __f_;
-#endif // defined(_LIBCPP_USING_DEV_RANDOM)
-public:
-    // types
-    typedef unsigned result_type;
-
-    // generator characteristics
-    static _LIBCPP_CONSTEXPR const result_type _Min = 0;
-    static _LIBCPP_CONSTEXPR const result_type _Max = 0xFFFFFFFFu;
-
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type min() { return _Min;}
-    _LIBCPP_INLINE_VISIBILITY
-    static _LIBCPP_CONSTEXPR result_type max() { return _Max;}
-
-    // constructors
-    explicit random_device(const string& __token = "/dev/urandom");
-    ~random_device();
-
-    // generating functions
-    result_type operator()();
-
-    // property functions
-    double entropy() const _NOEXCEPT;
-
-private:
-    // no copy functions
-    random_device(const random_device&); // = delete;
-    random_device& operator=(const random_device&); // = delete;
-};
-
-// seed_seq
-
-class _LIBCPP_TEMPLATE_VIS seed_seq
-{
-public:
-    // types
-    typedef uint32_t result_type;
-
-private:
-    vector<result_type> __v_;
-
-    template<class _InputIterator>
-        void init(_InputIterator __first, _InputIterator __last);
-public:
-    // constructors
-    _LIBCPP_INLINE_VISIBILITY
-    seed_seq() _NOEXCEPT {}
-#ifndef _LIBCPP_CXX03_LANG
-    template<class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        seed_seq(initializer_list<_Tp> __il) {init(__il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    template<class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        seed_seq(_InputIterator __first, _InputIterator __last)
-             {init(__first, __last);}
-
-    // generating functions
-    template<class _RandomAccessIterator>
-        void generate(_RandomAccessIterator __first, _RandomAccessIterator __last);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const _NOEXCEPT {return __v_.size();}
-    template<class _OutputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void param(_OutputIterator __dest) const
-            {_VSTD::copy(__v_.begin(), __v_.end(), __dest);}
-
-private:
-    // no copy functions
-    seed_seq(const seed_seq&); // = delete;
-    void operator=(const seed_seq&); // = delete;
-
-    _LIBCPP_INLINE_VISIBILITY
-    static result_type _Tp(result_type __x) {return __x ^ (__x >> 27);}
-};
-
-template<class _InputIterator>
-void
-seed_seq::init(_InputIterator __first, _InputIterator __last)
-{
-    for (_InputIterator __s = __first; __s != __last; ++__s)
-        __v_.push_back(*__s & 0xFFFFFFFF);
-}
-
-template<class _RandomAccessIterator>
-void
-seed_seq::generate(_RandomAccessIterator __first, _RandomAccessIterator __last)
-{
-    if (__first != __last)
-    {
-        _VSTD::fill(__first, __last, 0x8b8b8b8b);
-        const size_t __n = static_cast<size_t>(__last - __first);
-        const size_t __s = __v_.size();
-        const size_t __t = (__n >= 623) ? 11
-                         : (__n >= 68) ? 7
-                         : (__n >= 39) ? 5
-                         : (__n >= 7)  ? 3
-                         : (__n - 1) / 2;
-        const size_t __p = (__n - __t) / 2;
-        const size_t __q = __p + __t;
-        const size_t __m = _VSTD::max(__s + 1, __n);
-        // __k = 0;
-        {
-            result_type __r = 1664525 * _Tp(__first[0] ^ __first[__p]
-                                                      ^  __first[__n - 1]);
-            __first[__p] += __r;
-            __r += __s;
-            __first[__q] += __r;
-            __first[0] = __r;
-        }
-        for (size_t __k = 1; __k <= __s; ++__k)
-        {
-            const size_t __kmodn = __k % __n;
-            const size_t __kpmodn = (__k + __p) % __n;
-            result_type __r = 1664525 * _Tp(__first[__kmodn] ^ __first[__kpmodn]
-                                           ^ __first[(__k - 1) % __n]);
-            __first[__kpmodn] += __r;
-            __r +=  __kmodn + __v_[__k-1];
-            __first[(__k + __q) % __n] += __r;
-            __first[__kmodn] = __r;
-        }
-        for (size_t __k = __s + 1; __k < __m; ++__k)
-        {
-            const size_t __kmodn = __k % __n;
-            const size_t __kpmodn = (__k + __p) % __n;
-            result_type __r = 1664525 * _Tp(__first[__kmodn] ^ __first[__kpmodn]
-                                           ^ __first[(__k - 1) % __n]);
-            __first[__kpmodn] += __r;
-            __r +=  __kmodn;
-            __first[(__k + __q) % __n] += __r;
-            __first[__kmodn] = __r;
-        }
-        for (size_t __k = __m; __k < __m + __n; ++__k)
-        {
-            const size_t __kmodn = __k % __n;
-            const size_t __kpmodn = (__k + __p) % __n;
-            result_type __r = 1566083941 * _Tp(__first[__kmodn] +
-                                              __first[__kpmodn] +
-                                              __first[(__k - 1) % __n]);
-            __first[__kpmodn] ^= __r;
-            __r -= __kmodn;
-            __first[(__k + __q) % __n] ^= __r;
-            __first[__kmodn] = __r;
-        }
-    }
-}
-
-// generate_canonical
-
-template<class _RealType, size_t __bits, class _URNG>
-_RealType
-generate_canonical(_URNG& __g)
-{
-    const size_t _Dt = numeric_limits<_RealType>::digits;
-    const size_t __b = _Dt < __bits ? _Dt : __bits;
-#ifdef _LIBCPP_CXX03_LANG
-    const size_t __logR = __log2<uint64_t, _URNG::_Max - _URNG::_Min + uint64_t(1)>::value;
-#else
-    const size_t __logR = __log2<uint64_t, _URNG::max() - _URNG::min() + uint64_t(1)>::value;
-#endif
-    const size_t __k = __b / __logR + (__b % __logR != 0) + (__b == 0);
-    const _RealType _Rp = _URNG::max() - _URNG::min() + _RealType(1);
-    _RealType __base = _Rp;
-    _RealType _Sp = __g() - _URNG::min();
-    for (size_t __i = 1; __i < __k; ++__i, __base *= _Rp)
-        _Sp += (__g() - _URNG::min()) * __base;
-    return _Sp / __base;
-}
-
-// uniform_int_distribution
-
-// in <algorithm>
-
-template <class _CharT, class _Traits, class _IT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const uniform_int_distribution<_IT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    return __os << __x.a() << __sp << __x.b();
-}
-
-template <class _CharT, class _Traits, class _IT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           uniform_int_distribution<_IT>& __x)
-{
-    typedef uniform_int_distribution<_IT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __a;
-    result_type __b;
-    __is >> __a >> __b;
-    if (!__is.fail())
-        __x.param(param_type(__a, __b));
-    return __is;
-}
-
-// uniform_real_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS uniform_real_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __a_;
-        result_type __b_;
-    public:
-        typedef uniform_real_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __a = 0,
-                            result_type __b = 1)
-            : __a_(__a), __b_(__b) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type a() const {return __a_;}
-        _LIBCPP_INLINE_VISIBILITY
-        result_type b() const {return __b_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructors and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit uniform_real_distribution(result_type __a = 0, result_type __b = 1)
-        : __p_(param_type(__a, __b)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit uniform_real_distribution(const param_type& __p) : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type a() const {return __p_.a();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type b() const {return __p_.b();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return a();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return b();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const uniform_real_distribution& __x,
-                        const uniform_real_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const uniform_real_distribution& __x,
-                        const uniform_real_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template<class _RealType>
-template<class _URNG>
-inline
-typename uniform_real_distribution<_RealType>::result_type
-uniform_real_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    return (__p.b() - __p.a())
-        * _VSTD::generate_canonical<_RealType, numeric_limits<_RealType>::digits>(__g)
-        + __p.a();
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const uniform_real_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    return __os << __x.a() << __sp << __x.b();
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           uniform_real_distribution<_RT>& __x)
-{
-    typedef uniform_real_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __a;
-    result_type __b;
-    __is >> __a >> __b;
-    if (!__is.fail())
-        __x.param(param_type(__a, __b));
-    return __is;
-}
-
-// bernoulli_distribution
-
-class _LIBCPP_TEMPLATE_VIS bernoulli_distribution
-{
-public:
-    // types
-    typedef bool result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        double __p_;
-    public:
-        typedef bernoulli_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(double __p = 0.5) : __p_(__p) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        double p() const {return __p_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__p_ == __y.__p_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructors and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit bernoulli_distribution(double __p = 0.5)
-        : __p_(param_type(__p)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit bernoulli_distribution(const param_type& __p) : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    double p() const {return __p_.p();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return false;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return true;}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const bernoulli_distribution& __x,
-                        const bernoulli_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const bernoulli_distribution& __x,
-                        const bernoulli_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template<class _URNG>
-inline
-bernoulli_distribution::result_type
-bernoulli_distribution::operator()(_URNG& __g, const param_type& __p)
-{
-    uniform_real_distribution<double> __gen;
-    return __gen(__g) < __p.p();
-}
-
-template <class _CharT, class _Traits>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os, const bernoulli_distribution& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    return __os << __x.p();
-}
-
-template <class _CharT, class _Traits>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, bernoulli_distribution& __x)
-{
-    typedef bernoulli_distribution _Eng;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    double __p;
-    __is >> __p;
-    if (!__is.fail())
-        __x.param(param_type(__p));
-    return __is;
-}
-
-// binomial_distribution
-
-template<class _IntType = int>
-class _LIBCPP_TEMPLATE_VIS binomial_distribution
-{
-public:
-    // types
-    typedef _IntType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __t_;
-        double __p_;
-        double __pr_;
-        double __odds_ratio_;
-        result_type __r0_;
-    public:
-        typedef binomial_distribution distribution_type;
-
-        explicit param_type(result_type __t = 1, double __p = 0.5);
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type t() const {return __t_;}
-        _LIBCPP_INLINE_VISIBILITY
-        double p() const {return __p_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__t_ == __y.__t_ && __x.__p_ == __y.__p_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-
-        friend class binomial_distribution;
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructors and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit binomial_distribution(result_type __t = 1, double __p = 0.5)
-        : __p_(param_type(__t, __p)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit binomial_distribution(const param_type& __p) : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type t() const {return __p_.t();}
-    _LIBCPP_INLINE_VISIBILITY
-    double p() const {return __p_.p();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return t();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const binomial_distribution& __x,
-                        const binomial_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const binomial_distribution& __x,
-                        const binomial_distribution& __y)
-        {return !(__x == __y);}
-};
-
-#ifndef _LIBCPP_MSVCRT
-extern "C" double lgamma_r(double, int *);
-#endif
-
-inline _LIBCPP_INLINE_VISIBILITY double __libcpp_lgamma(double __d) {
-#if defined(_LIBCPP_MSVCRT)
-  return lgamma(__d);
-#else
-  int __sign;
-  return lgamma_r(__d, &__sign);
-#endif
-}
-
-template<class _IntType>
-binomial_distribution<_IntType>::param_type::param_type(const result_type __t, const double __p)
-    : __t_(__t), __p_(__p)
-{
-    if (0 < __p_ && __p_ < 1)
-    {
-        __r0_ = static_cast<result_type>((__t_ + 1) * __p_);
-        __pr_ = _VSTD::exp(__libcpp_lgamma(__t_ + 1.) -
-                           __libcpp_lgamma(__r0_ + 1.) -
-                           __libcpp_lgamma(__t_ - __r0_ + 1.) + __r0_ * _VSTD::log(__p_) +
-                           (__t_ - __r0_) * _VSTD::log(1 - __p_));
-        __odds_ratio_ = __p_ / (1 - __p_);
-    }
-}
-
-// Reference: Kemp, C.D. (1986). `A modal method for generating binomial
-//           variables', Commun. Statist. - Theor. Meth. 15(3), 805-813.
-template<class _IntType>
-template<class _URNG>
-_IntType
-binomial_distribution<_IntType>::operator()(_URNG& __g, const param_type& __pr)
-{
-    if (__pr.__t_ == 0 || __pr.__p_ == 0)
-        return 0;
-    if (__pr.__p_ == 1)
-        return __pr.__t_;
-    uniform_real_distribution<double> __gen;
-    double __u = __gen(__g) - __pr.__pr_;
-    if (__u < 0)
-        return __pr.__r0_;
-    double __pu = __pr.__pr_;
-    double __pd = __pu;
-    result_type __ru = __pr.__r0_;
-    result_type __rd = __ru;
-    while (true)
-    {
-        if (__rd >= 1)
-        {
-            __pd *= __rd / (__pr.__odds_ratio_ * (__pr.__t_ - __rd + 1));
-            __u -= __pd;
-            if (__u < 0)
-                return __rd - 1;
-        }
-        if ( __rd != 0 )
-            --__rd;
-        ++__ru;
-        if (__ru <= __pr.__t_)
-        {
-            __pu *= (__pr.__t_ - __ru + 1) * __pr.__odds_ratio_ / __ru;
-            __u -= __pu;
-            if (__u < 0)
-                return __ru;
-        }
-    }
-}
-
-template <class _CharT, class _Traits, class _IntType>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const binomial_distribution<_IntType>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    return __os << __x.t() << __sp << __x.p();
-}
-
-template <class _CharT, class _Traits, class _IntType>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           binomial_distribution<_IntType>& __x)
-{
-    typedef binomial_distribution<_IntType> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __t;
-    double __p;
-    __is >> __t >> __p;
-    if (!__is.fail())
-        __x.param(param_type(__t, __p));
-    return __is;
-}
-
-// exponential_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS exponential_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __lambda_;
-    public:
-        typedef exponential_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __lambda = 1) : __lambda_(__lambda) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type lambda() const {return __lambda_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__lambda_ == __y.__lambda_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructors and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit exponential_distribution(result_type __lambda = 1)
-        : __p_(param_type(__lambda)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit exponential_distribution(const param_type& __p) : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type lambda() const {return __p_.lambda();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const exponential_distribution& __x,
-                        const exponential_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const exponential_distribution& __x,
-                        const exponential_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template <class _RealType>
-template<class _URNG>
-_RealType
-exponential_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    return -_VSTD::log
-                  (
-                      result_type(1) -
-                      _VSTD::generate_canonical<result_type,
-                                       numeric_limits<result_type>::digits>(__g)
-                  )
-                  / __p.lambda();
-}
-
-template <class _CharT, class _Traits, class _RealType>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const exponential_distribution<_RealType>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    return __os << __x.lambda();
-}
-
-template <class _CharT, class _Traits, class _RealType>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           exponential_distribution<_RealType>& __x)
-{
-    typedef exponential_distribution<_RealType> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __lambda;
-    __is >> __lambda;
-    if (!__is.fail())
-        __x.param(param_type(__lambda));
-    return __is;
-}
-
-// normal_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS normal_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __mean_;
-        result_type __stddev_;
-    public:
-        typedef normal_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __mean = 0, result_type __stddev = 1)
-            : __mean_(__mean), __stddev_(__stddev) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type mean() const {return __mean_;}
-        _LIBCPP_INLINE_VISIBILITY
-        result_type stddev() const {return __stddev_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__mean_ == __y.__mean_ && __x.__stddev_ == __y.__stddev_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-    result_type _V_;
-    bool _V_hot_;
-
-public:
-    // constructors and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit normal_distribution(result_type __mean = 0, result_type __stddev = 1)
-        : __p_(param_type(__mean, __stddev)), _V_hot_(false) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit normal_distribution(const param_type& __p)
-        : __p_(__p), _V_hot_(false) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {_V_hot_ = false;}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type mean() const {return __p_.mean();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type stddev() const {return __p_.stddev();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return -numeric_limits<result_type>::infinity();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const normal_distribution& __x,
-                        const normal_distribution& __y)
-        {return __x.__p_ == __y.__p_ && __x._V_hot_ == __y._V_hot_ &&
-                (!__x._V_hot_ || __x._V_ == __y._V_);}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const normal_distribution& __x,
-                        const normal_distribution& __y)
-        {return !(__x == __y);}
-
-    template <class _CharT, class _Traits, class _RT>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const normal_distribution<_RT>& __x);
-
-    template <class _CharT, class _Traits, class _RT>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               normal_distribution<_RT>& __x);
-};
-
-template <class _RealType>
-template<class _URNG>
-_RealType
-normal_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    result_type _Up;
-    if (_V_hot_)
-    {
-        _V_hot_ = false;
-        _Up = _V_;
-    }
-    else
-    {
-        uniform_real_distribution<result_type> _Uni(-1, 1);
-        result_type __u;
-        result_type __v;
-        result_type __s;
-        do
-        {
-            __u = _Uni(__g);
-            __v = _Uni(__g);
-            __s = __u * __u + __v * __v;
-        } while (__s > 1 || __s == 0);
-        result_type _Fp = _VSTD::sqrt(-2 * _VSTD::log(__s) / __s);
-        _V_ = __v * _Fp;
-        _V_hot_ = true;
-        _Up = __u * _Fp;
-    }
-    return _Up * __p.stddev() + __p.mean();
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const normal_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    __os << __x.mean() << __sp << __x.stddev() << __sp << __x._V_hot_;
-    if (__x._V_hot_)
-        __os << __sp << __x._V_;
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           normal_distribution<_RT>& __x)
-{
-    typedef normal_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __mean;
-    result_type __stddev;
-    result_type _Vp = 0;
-    bool _V_hot = false;
-    __is >> __mean >> __stddev >> _V_hot;
-    if (_V_hot)
-        __is >> _Vp;
-    if (!__is.fail())
-    {
-        __x.param(param_type(__mean, __stddev));
-        __x._V_hot_ = _V_hot;
-        __x._V_ = _Vp;
-    }
-    return __is;
-}
-
-// lognormal_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS lognormal_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        normal_distribution<result_type> __nd_;
-    public:
-        typedef lognormal_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __m = 0, result_type __s = 1)
-            : __nd_(__m, __s) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type m() const {return __nd_.mean();}
-        _LIBCPP_INLINE_VISIBILITY
-        result_type s() const {return __nd_.stddev();}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__nd_ == __y.__nd_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-        friend class lognormal_distribution;
-
-        template <class _CharT, class _Traits, class _RT>
-        friend
-        basic_ostream<_CharT, _Traits>&
-        operator<<(basic_ostream<_CharT, _Traits>& __os,
-                   const lognormal_distribution<_RT>& __x);
-
-        template <class _CharT, class _Traits, class _RT>
-        friend
-        basic_istream<_CharT, _Traits>&
-        operator>>(basic_istream<_CharT, _Traits>& __is,
-                   lognormal_distribution<_RT>& __x);
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit lognormal_distribution(result_type __m = 0, result_type __s = 1)
-        : __p_(param_type(__m, __s)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit lognormal_distribution(const param_type& __p)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {__p_.__nd_.reset();}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g, const param_type& __p)
-        {return _VSTD::exp(const_cast<normal_distribution<result_type>&>(__p.__nd_)(__g));}
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type m() const {return __p_.m();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type s() const {return __p_.s();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const lognormal_distribution& __x,
-                        const lognormal_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const lognormal_distribution& __x,
-                        const lognormal_distribution& __y)
-        {return !(__x == __y);}
-
-    template <class _CharT, class _Traits, class _RT>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const lognormal_distribution<_RT>& __x);
-
-    template <class _CharT, class _Traits, class _RT>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               lognormal_distribution<_RT>& __x);
-};
-
-template <class _CharT, class _Traits, class _RT>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const lognormal_distribution<_RT>& __x)
-{
-    return __os << __x.__p_.__nd_;
-}
-
-template <class _CharT, class _Traits, class _RT>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           lognormal_distribution<_RT>& __x)
-{
-    return __is >> __x.__p_.__nd_;
-}
-
-// poisson_distribution
-
-template<class _IntType = int>
-class _LIBCPP_TEMPLATE_VIS poisson_distribution
-{
-public:
-    // types
-    typedef _IntType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        double __mean_;
-        double __s_;
-        double __d_;
-        double __l_;
-        double __omega_;
-        double __c0_;
-        double __c1_;
-        double __c2_;
-        double __c3_;
-        double __c_;
-
-    public:
-        typedef poisson_distribution distribution_type;
-
-        explicit param_type(double __mean = 1.0);
-
-        _LIBCPP_INLINE_VISIBILITY
-        double mean() const {return __mean_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__mean_ == __y.__mean_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-
-        friend class poisson_distribution;
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructors and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit poisson_distribution(double __mean = 1.0) : __p_(__mean) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit poisson_distribution(const param_type& __p) : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    double mean() const {return __p_.mean();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::max();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const poisson_distribution& __x,
-                        const poisson_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const poisson_distribution& __x,
-                        const poisson_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template<class _IntType>
-poisson_distribution<_IntType>::param_type::param_type(double __mean)
-    : __mean_(__mean)
-{
-    if (__mean_ < 10)
-    {
-        __s_ = 0;
-        __d_ = 0;
-        __l_ = _VSTD::exp(-__mean_);
-        __omega_ = 0;
-        __c3_ = 0;
-        __c2_ = 0;
-        __c1_ = 0;
-        __c0_ = 0;
-        __c_ = 0;
-    }
-    else
-    {
-        __s_ = _VSTD::sqrt(__mean_);
-        __d_ = 6 * __mean_ * __mean_;
-        __l_ = static_cast<result_type>(__mean_ - 1.1484);
-        __omega_ = .3989423 / __s_;
-        double __b1_ = .4166667E-1 / __mean_;
-        double __b2_ = .3 * __b1_ * __b1_;
-        __c3_ = .1428571 * __b1_ * __b2_;
-        __c2_ = __b2_ - 15. * __c3_;
-        __c1_ = __b1_ - 6. * __b2_ + 45. * __c3_;
-        __c0_ = 1. - __b1_ + 3. * __b2_ - 15. * __c3_;
-        __c_ = .1069 / __mean_;
-    }
-}
-
-template <class _IntType>
-template<class _URNG>
-_IntType
-poisson_distribution<_IntType>::operator()(_URNG& __urng, const param_type& __pr)
-{
-    result_type __x;
-    uniform_real_distribution<double> __urd;
-    if (__pr.__mean_ < 10)
-    {
-         __x = 0;
-        for (double __p = __urd(__urng); __p > __pr.__l_; ++__x)
-            __p *= __urd(__urng);
-    }
-    else
-    {
-        double __difmuk;
-        double __g = __pr.__mean_ + __pr.__s_ * normal_distribution<double>()(__urng);
-        double __u;
-        if (__g > 0)
-        {
-            __x = static_cast<result_type>(__g);
-            if (__x >= __pr.__l_)
-                return __x;
-            __difmuk = __pr.__mean_ - __x;
-            __u = __urd(__urng);
-            if (__pr.__d_ * __u >= __difmuk * __difmuk * __difmuk)
-                return __x;
-        }
-        exponential_distribution<double> __edist;
-        for (bool __using_exp_dist = false; true; __using_exp_dist = true)
-        {
-            double __e;
-            if (__using_exp_dist || __g < 0)
-            {
-                double __t;
-                do
-                {
-                    __e = __edist(__urng);
-                    __u = __urd(__urng);
-                    __u += __u - 1;
-                    __t = 1.8 + (__u < 0 ? -__e : __e);
-                } while (__t <= -.6744);
-                __x = __pr.__mean_ + __pr.__s_ * __t;
-                __difmuk = __pr.__mean_ - __x;
-                __using_exp_dist = true;
-            }
-            double __px;
-            double __py;
-            if (__x < 10)
-            {
-                const double __fac[] = {1, 1, 2, 6, 24, 120, 720, 5040,
-                                             40320, 362880};
-                __px = -__pr.__mean_;
-                __py = _VSTD::pow(__pr.__mean_, (double)__x) / __fac[__x];
-            }
-            else
-            {
-                double __del = .8333333E-1 / __x;
-                __del -= 4.8 * __del * __del * __del;
-                double __v = __difmuk / __x;
-                if (_VSTD::abs(__v) > 0.25)
-                    __px = __x * _VSTD::log(1 + __v) - __difmuk - __del;
-                else
-                    __px = __x * __v * __v * (((((((.1250060 * __v + -.1384794) *
-                           __v + .1421878) * __v + -.1661269) * __v + .2000118) *
-                           __v + -.2500068) * __v + .3333333) * __v + -.5) - __del;
-                __py = .3989423 / _VSTD::sqrt(__x);
-            }
-            double __r = (0.5 - __difmuk) / __pr.__s_;
-            double __r2 = __r * __r;
-            double __fx = -0.5 * __r2;
-            double __fy = __pr.__omega_ * (((__pr.__c3_ * __r2 + __pr.__c2_) *
-                                        __r2 + __pr.__c1_) * __r2 + __pr.__c0_);
-            if (__using_exp_dist)
-            {
-                if (__pr.__c_ * _VSTD::abs(__u) <= __py * _VSTD::exp(__px + __e) -
-                                                   __fy * _VSTD::exp(__fx + __e))
-                    break;
-            }
-            else
-            {
-                if (__fy - __u * __fy <= __py * _VSTD::exp(__px - __fx))
-                    break;
-            }
-        }
-    }
-    return __x;
-}
-
-template <class _CharT, class _Traits, class _IntType>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const poisson_distribution<_IntType>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    return __os << __x.mean();
-}
-
-template <class _CharT, class _Traits, class _IntType>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           poisson_distribution<_IntType>& __x)
-{
-    typedef poisson_distribution<_IntType> _Eng;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    double __mean;
-    __is >> __mean;
-    if (!__is.fail())
-        __x.param(param_type(__mean));
-    return __is;
-}
-
-// weibull_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS weibull_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __a_;
-        result_type __b_;
-    public:
-        typedef weibull_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __a = 1, result_type __b = 1)
-            : __a_(__a), __b_(__b) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type a() const {return __a_;}
-        _LIBCPP_INLINE_VISIBILITY
-        result_type b() const {return __b_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit weibull_distribution(result_type __a = 1, result_type __b = 1)
-        : __p_(param_type(__a, __b)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit weibull_distribution(const param_type& __p)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g, const param_type& __p)
-        {return __p.b() *
-            _VSTD::pow(exponential_distribution<result_type>()(__g), 1/__p.a());}
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type a() const {return __p_.a();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type b() const {return __p_.b();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const weibull_distribution& __x,
-                        const weibull_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const weibull_distribution& __x,
-                        const weibull_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const weibull_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    __os << __x.a() << __sp << __x.b();
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           weibull_distribution<_RT>& __x)
-{
-    typedef weibull_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __a;
-    result_type __b;
-    __is >> __a >> __b;
-    if (!__is.fail())
-        __x.param(param_type(__a, __b));
-    return __is;
-}
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS extreme_value_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __a_;
-        result_type __b_;
-    public:
-        typedef extreme_value_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __a = 0, result_type __b = 1)
-            : __a_(__a), __b_(__b) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type a() const {return __a_;}
-        _LIBCPP_INLINE_VISIBILITY
-        result_type b() const {return __b_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit extreme_value_distribution(result_type __a = 0, result_type __b = 1)
-        : __p_(param_type(__a, __b)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit extreme_value_distribution(const param_type& __p)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type a() const {return __p_.a();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type b() const {return __p_.b();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return -numeric_limits<result_type>::infinity();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const extreme_value_distribution& __x,
-                        const extreme_value_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const extreme_value_distribution& __x,
-                        const extreme_value_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template<class _RealType>
-template<class _URNG>
-_RealType
-extreme_value_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    return __p.a() - __p.b() *
-         _VSTD::log(-_VSTD::log(1-uniform_real_distribution<result_type>()(__g)));
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const extreme_value_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    __os << __x.a() << __sp << __x.b();
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           extreme_value_distribution<_RT>& __x)
-{
-    typedef extreme_value_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __a;
-    result_type __b;
-    __is >> __a >> __b;
-    if (!__is.fail())
-        __x.param(param_type(__a, __b));
-    return __is;
-}
-
-// gamma_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS gamma_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __alpha_;
-        result_type __beta_;
-    public:
-        typedef gamma_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __alpha = 1, result_type __beta = 1)
-            : __alpha_(__alpha), __beta_(__beta) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type alpha() const {return __alpha_;}
-        _LIBCPP_INLINE_VISIBILITY
-        result_type beta() const {return __beta_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__alpha_ == __y.__alpha_ && __x.__beta_ == __y.__beta_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructors and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit gamma_distribution(result_type __alpha = 1, result_type __beta = 1)
-        : __p_(param_type(__alpha, __beta)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit gamma_distribution(const param_type& __p)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type alpha() const {return __p_.alpha();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type beta() const {return __p_.beta();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const gamma_distribution& __x,
-                        const gamma_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const gamma_distribution& __x,
-                        const gamma_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template <class _RealType>
-template<class _URNG>
-_RealType
-gamma_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    result_type __a = __p.alpha();
-    uniform_real_distribution<result_type> __gen(0, 1);
-    exponential_distribution<result_type> __egen;
-    result_type __x;
-    if (__a == 1)
-        __x = __egen(__g);
-    else if (__a > 1)
-    {
-        const result_type __b = __a - 1;
-        const result_type __c = 3 * __a - result_type(0.75);
-        while (true)
-        {
-            const result_type __u = __gen(__g);
-            const result_type __v = __gen(__g);
-            const result_type __w = __u * (1 - __u);
-            if (__w != 0)
-            {
-                const result_type __y = _VSTD::sqrt(__c / __w) *
-                                        (__u - result_type(0.5));
-                __x = __b + __y;
-                if (__x >= 0)
-                {
-                    const result_type __z = 64 * __w * __w * __w * __v * __v;
-                    if (__z <= 1 - 2 * __y * __y / __x)
-                        break;
-                    if (_VSTD::log(__z) <= 2 * (__b * _VSTD::log(__x / __b) - __y))
-                        break;
-                }
-            }
-        }
-    }
-    else  // __a < 1
-    {
-        while (true)
-        {
-            const result_type __u = __gen(__g);
-            const result_type __es = __egen(__g);
-            if (__u <= 1 - __a)
-            {
-                __x = _VSTD::pow(__u, 1 / __a);
-                if (__x <= __es)
-                    break;
-            }
-            else
-            {
-                const result_type __e = -_VSTD::log((1-__u)/__a);
-                __x = _VSTD::pow(1 - __a + __a * __e, 1 / __a);
-                if (__x <= __e + __es)
-                    break;
-            }
-        }
-    }
-    return __x * __p.beta();
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const gamma_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    __os << __x.alpha() << __sp << __x.beta();
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           gamma_distribution<_RT>& __x)
-{
-    typedef gamma_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __alpha;
-    result_type __beta;
-    __is >> __alpha >> __beta;
-    if (!__is.fail())
-        __x.param(param_type(__alpha, __beta));
-    return __is;
-}
-
-// negative_binomial_distribution
-
-template<class _IntType = int>
-class _LIBCPP_TEMPLATE_VIS negative_binomial_distribution
-{
-public:
-    // types
-    typedef _IntType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __k_;
-        double __p_;
-    public:
-        typedef negative_binomial_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __k = 1, double __p = 0.5)
-            : __k_(__k), __p_(__p) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type k() const {return __k_;}
-        _LIBCPP_INLINE_VISIBILITY
-        double p() const {return __p_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__k_ == __y.__k_ && __x.__p_ == __y.__p_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit negative_binomial_distribution(result_type __k = 1, double __p = 0.5)
-        : __p_(__k, __p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit negative_binomial_distribution(const param_type& __p) : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type k() const {return __p_.k();}
-    _LIBCPP_INLINE_VISIBILITY
-    double p() const {return __p_.p();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::max();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const negative_binomial_distribution& __x,
-                        const negative_binomial_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const negative_binomial_distribution& __x,
-                        const negative_binomial_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template <class _IntType>
-template<class _URNG>
-_IntType
-negative_binomial_distribution<_IntType>::operator()(_URNG& __urng, const param_type& __pr)
-{
-    result_type __k = __pr.k();
-    double __p = __pr.p();
-    if (__k <= 21 * __p)
-    {
-        bernoulli_distribution __gen(__p);
-        result_type __f = 0;
-        result_type __s = 0;
-        while (__s < __k)
-        {
-            if (__gen(__urng))
-                ++__s;
-            else
-                ++__f;
-        }
-        return __f;
-    }
-    return poisson_distribution<result_type>(gamma_distribution<double>
-                                            (__k, (1-__p)/__p)(__urng))(__urng);
-}
-
-template <class _CharT, class _Traits, class _IntType>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const negative_binomial_distribution<_IntType>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    return __os << __x.k() << __sp << __x.p();
-}
-
-template <class _CharT, class _Traits, class _IntType>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           negative_binomial_distribution<_IntType>& __x)
-{
-    typedef negative_binomial_distribution<_IntType> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __k;
-    double __p;
-    __is >> __k >> __p;
-    if (!__is.fail())
-        __x.param(param_type(__k, __p));
-    return __is;
-}
-
-// geometric_distribution
-
-template<class _IntType = int>
-class _LIBCPP_TEMPLATE_VIS geometric_distribution
-{
-public:
-    // types
-    typedef _IntType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        double __p_;
-    public:
-        typedef geometric_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(double __p = 0.5) : __p_(__p) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        double p() const {return __p_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__p_ == __y.__p_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructors and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit geometric_distribution(double __p = 0.5) : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit geometric_distribution(const param_type& __p) : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g, const param_type& __p)
-        {return negative_binomial_distribution<result_type>(1, __p.p())(__g);}
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    double p() const {return __p_.p();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::max();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const geometric_distribution& __x,
-                        const geometric_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const geometric_distribution& __x,
-                        const geometric_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template <class _CharT, class _Traits, class _IntType>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const geometric_distribution<_IntType>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    return __os << __x.p();
-}
-
-template <class _CharT, class _Traits, class _IntType>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           geometric_distribution<_IntType>& __x)
-{
-    typedef geometric_distribution<_IntType> _Eng;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    double __p;
-    __is >> __p;
-    if (!__is.fail())
-        __x.param(param_type(__p));
-    return __is;
-}
-
-// chi_squared_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS chi_squared_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __n_;
-    public:
-        typedef chi_squared_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __n = 1) : __n_(__n) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type n() const {return __n_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__n_ == __y.__n_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit chi_squared_distribution(result_type __n = 1)
-        : __p_(param_type(__n)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit chi_squared_distribution(const param_type& __p)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g, const param_type& __p)
-        {return gamma_distribution<result_type>(__p.n() / 2, 2)(__g);}
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type n() const {return __p_.n();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const chi_squared_distribution& __x,
-                        const chi_squared_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const chi_squared_distribution& __x,
-                        const chi_squared_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const chi_squared_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    __os << __x.n();
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           chi_squared_distribution<_RT>& __x)
-{
-    typedef chi_squared_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __n;
-    __is >> __n;
-    if (!__is.fail())
-        __x.param(param_type(__n));
-    return __is;
-}
-
-// cauchy_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS cauchy_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __a_;
-        result_type __b_;
-    public:
-        typedef cauchy_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __a = 0, result_type __b = 1)
-            : __a_(__a), __b_(__b) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type a() const {return __a_;}
-        _LIBCPP_INLINE_VISIBILITY
-        result_type b() const {return __b_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__a_ == __y.__a_ && __x.__b_ == __y.__b_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit cauchy_distribution(result_type __a = 0, result_type __b = 1)
-        : __p_(param_type(__a, __b)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit cauchy_distribution(const param_type& __p)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> _LIBCPP_INLINE_VISIBILITY result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type a() const {return __p_.a();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type b() const {return __p_.b();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return -numeric_limits<result_type>::infinity();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const cauchy_distribution& __x,
-                        const cauchy_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const cauchy_distribution& __x,
-                        const cauchy_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template <class _RealType>
-template<class _URNG>
-inline
-_RealType
-cauchy_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    uniform_real_distribution<result_type> __gen;
-    // purposefully let tan arg get as close to pi/2 as it wants, tan will return a finite
-    return __p.a() + __p.b() * _VSTD::tan(3.1415926535897932384626433832795 * __gen(__g));
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const cauchy_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    __os << __x.a() << __sp << __x.b();
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           cauchy_distribution<_RT>& __x)
-{
-    typedef cauchy_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __a;
-    result_type __b;
-    __is >> __a >> __b;
-    if (!__is.fail())
-        __x.param(param_type(__a, __b));
-    return __is;
-}
-
-// fisher_f_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS fisher_f_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __m_;
-        result_type __n_;
-    public:
-        typedef fisher_f_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __m = 1, result_type __n = 1)
-            : __m_(__m), __n_(__n) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type m() const {return __m_;}
-        _LIBCPP_INLINE_VISIBILITY
-        result_type n() const {return __n_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__m_ == __y.__m_ && __x.__n_ == __y.__n_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit fisher_f_distribution(result_type __m = 1, result_type __n = 1)
-        : __p_(param_type(__m, __n)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit fisher_f_distribution(const param_type& __p)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type m() const {return __p_.m();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type n() const {return __p_.n();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const fisher_f_distribution& __x,
-                        const fisher_f_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const fisher_f_distribution& __x,
-                        const fisher_f_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template <class _RealType>
-template<class _URNG>
-_RealType
-fisher_f_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    gamma_distribution<result_type> __gdm(__p.m() * result_type(.5));
-    gamma_distribution<result_type> __gdn(__p.n() * result_type(.5));
-    return __p.n() * __gdm(__g) / (__p.m() * __gdn(__g));
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const fisher_f_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    __os << __x.m() << __sp << __x.n();
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           fisher_f_distribution<_RT>& __x)
-{
-    typedef fisher_f_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __m;
-    result_type __n;
-    __is >> __m >> __n;
-    if (!__is.fail())
-        __x.param(param_type(__m, __n));
-    return __is;
-}
-
-// student_t_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS student_t_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        result_type __n_;
-    public:
-        typedef student_t_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        explicit param_type(result_type __n = 1) : __n_(__n) {}
-
-        _LIBCPP_INLINE_VISIBILITY
-        result_type n() const {return __n_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__n_ == __y.__n_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-    };
-
-private:
-    param_type __p_;
-    normal_distribution<result_type> __nd_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    explicit student_t_distribution(result_type __n = 1)
-        : __p_(param_type(__n)) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit student_t_distribution(const param_type& __p)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {__nd_.reset();}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    result_type n() const {return __p_.n();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return -numeric_limits<result_type>::infinity();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return numeric_limits<result_type>::infinity();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const student_t_distribution& __x,
-                        const student_t_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const student_t_distribution& __x,
-                        const student_t_distribution& __y)
-        {return !(__x == __y);}
-};
-
-template <class _RealType>
-template<class _URNG>
-_RealType
-student_t_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    gamma_distribution<result_type> __gd(__p.n() * .5, 2);
-    return __nd_(__g) * _VSTD::sqrt(__p.n()/__gd(__g));
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const student_t_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    __os << __x.n();
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           student_t_distribution<_RT>& __x)
-{
-    typedef student_t_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    typedef typename _Eng::param_type param_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    result_type __n;
-    __is >> __n;
-    if (!__is.fail())
-        __x.param(param_type(__n));
-    return __is;
-}
-
-// discrete_distribution
-
-template<class _IntType = int>
-class _LIBCPP_TEMPLATE_VIS discrete_distribution
-{
-public:
-    // types
-    typedef _IntType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        vector<double> __p_;
-    public:
-        typedef discrete_distribution distribution_type;
-
-        _LIBCPP_INLINE_VISIBILITY
-        param_type() {}
-        template<class _InputIterator>
-            _LIBCPP_INLINE_VISIBILITY
-            param_type(_InputIterator __f, _InputIterator __l)
-            : __p_(__f, __l) {__init();}
-#ifndef _LIBCPP_CXX03_LANG
-        _LIBCPP_INLINE_VISIBILITY
-        param_type(initializer_list<double> __wl)
-            : __p_(__wl.begin(), __wl.end()) {__init();}
-#endif  // _LIBCPP_CXX03_LANG
-        template<class _UnaryOperation>
-            param_type(size_t __nw, double __xmin, double __xmax,
-                       _UnaryOperation __fw);
-
-        vector<double> probabilities() const;
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__p_ == __y.__p_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-
-    private:
-        void __init();
-
-        friend class discrete_distribution;
-
-        template <class _CharT, class _Traits, class _IT>
-        friend
-        basic_ostream<_CharT, _Traits>&
-        operator<<(basic_ostream<_CharT, _Traits>& __os,
-                   const discrete_distribution<_IT>& __x);
-
-        template <class _CharT, class _Traits, class _IT>
-        friend
-        basic_istream<_CharT, _Traits>&
-        operator>>(basic_istream<_CharT, _Traits>& __is,
-                   discrete_distribution<_IT>& __x);
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    discrete_distribution() {}
-    template<class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        discrete_distribution(_InputIterator __f, _InputIterator __l)
-            : __p_(__f, __l) {}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    discrete_distribution(initializer_list<double> __wl)
-        : __p_(__wl) {}
-#endif  // _LIBCPP_CXX03_LANG
-    template<class _UnaryOperation>
-        _LIBCPP_INLINE_VISIBILITY
-        discrete_distribution(size_t __nw, double __xmin, double __xmax,
-                              _UnaryOperation __fw)
-        : __p_(__nw, __xmin, __xmax, __fw) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit discrete_distribution(const param_type& __p)
-        : __p_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    vector<double> probabilities() const {return __p_.probabilities();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return __p_.__p_.size();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const discrete_distribution& __x,
-                        const discrete_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const discrete_distribution& __x,
-                        const discrete_distribution& __y)
-        {return !(__x == __y);}
-
-    template <class _CharT, class _Traits, class _IT>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const discrete_distribution<_IT>& __x);
-
-    template <class _CharT, class _Traits, class _IT>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               discrete_distribution<_IT>& __x);
-};
-
-template<class _IntType>
-template<class _UnaryOperation>
-discrete_distribution<_IntType>::param_type::param_type(size_t __nw,
-                                                        double __xmin,
-                                                        double __xmax,
-                                                        _UnaryOperation __fw)
-{
-    if (__nw > 1)
-    {
-        __p_.reserve(__nw - 1);
-        double __d = (__xmax - __xmin) / __nw;
-        double __d2 = __d / 2;
-        for (size_t __k = 0; __k < __nw; ++__k)
-            __p_.push_back(__fw(__xmin + __k * __d + __d2));
-        __init();
-    }
-}
-
-template<class _IntType>
-void
-discrete_distribution<_IntType>::param_type::__init()
-{
-    if (!__p_.empty())
-    {
-        if (__p_.size() > 1)
-        {
-            double __s = _VSTD::accumulate(__p_.begin(), __p_.end(), 0.0);
-            for (_VSTD::vector<double>::iterator __i = __p_.begin(), __e = __p_.end();
-                                                                       __i < __e; ++__i)
-                *__i /= __s;
-            vector<double> __t(__p_.size() - 1);
-            _VSTD::partial_sum(__p_.begin(), __p_.end() - 1, __t.begin());
-            swap(__p_, __t);
-        }
-        else
-        {
-            __p_.clear();
-            __p_.shrink_to_fit();
-        }
-    }
-}
-
-template<class _IntType>
-vector<double>
-discrete_distribution<_IntType>::param_type::probabilities() const
-{
-    size_t __n = __p_.size();
-    _VSTD::vector<double> __p(__n+1);
-    _VSTD::adjacent_difference(__p_.begin(), __p_.end(), __p.begin());
-    if (__n > 0)
-        __p[__n] = 1 - __p_[__n-1];
-    else
-        __p[0] = 1;
-    return __p;
-}
-
-template<class _IntType>
-template<class _URNG>
-_IntType
-discrete_distribution<_IntType>::operator()(_URNG& __g, const param_type& __p)
-{
-    uniform_real_distribution<double> __gen;
-    return static_cast<_IntType>(
-           _VSTD::upper_bound(__p.__p_.begin(), __p.__p_.end(), __gen(__g)) -
-                                                              __p.__p_.begin());
-}
-
-template <class _CharT, class _Traits, class _IT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const discrete_distribution<_IT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    size_t __n = __x.__p_.__p_.size();
-    __os << __n;
-    for (size_t __i = 0; __i < __n; ++__i)
-        __os << __sp << __x.__p_.__p_[__i];
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _IT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           discrete_distribution<_IT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    size_t __n;
-    __is >> __n;
-    vector<double> __p(__n);
-    for (size_t __i = 0; __i < __n; ++__i)
-        __is >> __p[__i];
-    if (!__is.fail())
-        swap(__x.__p_.__p_, __p);
-    return __is;
-}
-
-// piecewise_constant_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS piecewise_constant_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        vector<result_type> __b_;
-        vector<result_type> __densities_;
-        vector<result_type> __areas_;
-    public:
-        typedef piecewise_constant_distribution distribution_type;
-
-        param_type();
-        template<class _InputIteratorB, class _InputIteratorW>
-            param_type(_InputIteratorB __fB, _InputIteratorB __lB,
-                       _InputIteratorW __fW);
-#ifndef _LIBCPP_CXX03_LANG
-        template<class _UnaryOperation>
-            param_type(initializer_list<result_type> __bl, _UnaryOperation __fw);
-#endif  // _LIBCPP_CXX03_LANG
-        template<class _UnaryOperation>
-            param_type(size_t __nw, result_type __xmin, result_type __xmax,
-                       _UnaryOperation __fw);
-        param_type & operator=(const param_type& __rhs);
-
-        _LIBCPP_INLINE_VISIBILITY
-        vector<result_type> intervals() const {return __b_;}
-        _LIBCPP_INLINE_VISIBILITY
-        vector<result_type> densities() const {return __densities_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-
-    private:
-        void __init();
-
-        friend class piecewise_constant_distribution;
-
-        template <class _CharT, class _Traits, class _RT>
-        friend
-        basic_ostream<_CharT, _Traits>&
-        operator<<(basic_ostream<_CharT, _Traits>& __os,
-                   const piecewise_constant_distribution<_RT>& __x);
-
-        template <class _CharT, class _Traits, class _RT>
-        friend
-        basic_istream<_CharT, _Traits>&
-        operator>>(basic_istream<_CharT, _Traits>& __is,
-                   piecewise_constant_distribution<_RT>& __x);
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    piecewise_constant_distribution() {}
-    template<class _InputIteratorB, class _InputIteratorW>
-        _LIBCPP_INLINE_VISIBILITY
-        piecewise_constant_distribution(_InputIteratorB __fB,
-                                        _InputIteratorB __lB,
-                                        _InputIteratorW __fW)
-        : __p_(__fB, __lB, __fW) {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    template<class _UnaryOperation>
-        _LIBCPP_INLINE_VISIBILITY
-        piecewise_constant_distribution(initializer_list<result_type> __bl,
-                                        _UnaryOperation __fw)
-        : __p_(__bl, __fw) {}
-#endif  // _LIBCPP_CXX03_LANG
-
-    template<class _UnaryOperation>
-        _LIBCPP_INLINE_VISIBILITY
-        piecewise_constant_distribution(size_t __nw, result_type __xmin,
-                                        result_type __xmax, _UnaryOperation __fw)
-        : __p_(__nw, __xmin, __xmax, __fw) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit piecewise_constant_distribution(const param_type& __p)
-        : __p_(__p) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    vector<result_type> intervals() const {return __p_.intervals();}
-    _LIBCPP_INLINE_VISIBILITY
-    vector<result_type> densities() const {return __p_.densities();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return __p_.__b_.front();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return __p_.__b_.back();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const piecewise_constant_distribution& __x,
-                        const piecewise_constant_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const piecewise_constant_distribution& __x,
-                           const piecewise_constant_distribution& __y)
-        {return !(__x == __y);}
-
-    template <class _CharT, class _Traits, class _RT>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const piecewise_constant_distribution<_RT>& __x);
-
-    template <class _CharT, class _Traits, class _RT>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               piecewise_constant_distribution<_RT>& __x);
-};
-
-template<class _RealType>
-typename piecewise_constant_distribution<_RealType>::param_type &
-piecewise_constant_distribution<_RealType>::param_type::operator=
-                                                       (const param_type& __rhs)
-{
-//  These can throw
-    __b_.reserve        (__rhs.__b_.size ());
-    __densities_.reserve(__rhs.__densities_.size());
-    __areas_.reserve    (__rhs.__areas_.size());
-
-//  These can not throw
-    __b_         = __rhs.__b_;
-    __densities_ = __rhs.__densities_;
-    __areas_     =  __rhs.__areas_;
-    return *this;
-}
-
-template<class _RealType>
-void
-piecewise_constant_distribution<_RealType>::param_type::__init()
-{
-    // __densities_ contains non-normalized areas
-    result_type __total_area = _VSTD::accumulate(__densities_.begin(),
-                                                __densities_.end(),
-                                                result_type());
-    for (size_t __i = 0; __i < __densities_.size(); ++__i)
-        __densities_[__i] /= __total_area;
-    // __densities_ contains normalized areas
-    __areas_.assign(__densities_.size(), result_type());
-    _VSTD::partial_sum(__densities_.begin(), __densities_.end() - 1,
-                                                          __areas_.begin() + 1);
-    // __areas_ contains partial sums of normalized areas: [0, __densities_ - 1]
-    __densities_.back() = 1 - __areas_.back();  // correct round off error
-    for (size_t __i = 0; __i < __densities_.size(); ++__i)
-        __densities_[__i] /= (__b_[__i+1] - __b_[__i]);
-    // __densities_ now contains __densities_
-}
-
-template<class _RealType>
-piecewise_constant_distribution<_RealType>::param_type::param_type()
-    : __b_(2),
-      __densities_(1, 1.0),
-      __areas_(1, 0.0)
-{
-    __b_[1] = 1;
-}
-
-template<class _RealType>
-template<class _InputIteratorB, class _InputIteratorW>
-piecewise_constant_distribution<_RealType>::param_type::param_type(
-        _InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW)
-    : __b_(__fB, __lB)
-{
-    if (__b_.size() < 2)
-    {
-        __b_.resize(2);
-        __b_[0] = 0;
-        __b_[1] = 1;
-        __densities_.assign(1, 1.0);
-        __areas_.assign(1, 0.0);
-    }
-    else
-    {
-        __densities_.reserve(__b_.size() - 1);
-        for (size_t __i = 0; __i < __b_.size() - 1; ++__i, ++__fW)
-            __densities_.push_back(*__fW);
-        __init();
-    }
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _RealType>
-template<class _UnaryOperation>
-piecewise_constant_distribution<_RealType>::param_type::param_type(
-        initializer_list<result_type> __bl, _UnaryOperation __fw)
-    : __b_(__bl.begin(), __bl.end())
-{
-    if (__b_.size() < 2)
-    {
-        __b_.resize(2);
-        __b_[0] = 0;
-        __b_[1] = 1;
-        __densities_.assign(1, 1.0);
-        __areas_.assign(1, 0.0);
-    }
-    else
-    {
-        __densities_.reserve(__b_.size() - 1);
-        for (size_t __i = 0; __i < __b_.size() - 1; ++__i)
-            __densities_.push_back(__fw((__b_[__i+1] + __b_[__i])*.5));
-        __init();
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template<class _RealType>
-template<class _UnaryOperation>
-piecewise_constant_distribution<_RealType>::param_type::param_type(
-        size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw)
-    : __b_(__nw == 0 ? 2 : __nw + 1)
-{
-    size_t __n = __b_.size() - 1;
-    result_type __d = (__xmax - __xmin) / __n;
-    __densities_.reserve(__n);
-    for (size_t __i = 0; __i < __n; ++__i)
-    {
-        __b_[__i] = __xmin + __i * __d;
-        __densities_.push_back(__fw(__b_[__i] + __d*.5));
-    }
-    __b_[__n] = __xmax;
-    __init();
-}
-
-template<class _RealType>
-template<class _URNG>
-_RealType
-piecewise_constant_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    typedef uniform_real_distribution<result_type> _Gen;
-    result_type __u = _Gen()(__g);
-    ptrdiff_t __k = _VSTD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(),
-                                      __u) - __p.__areas_.begin() - 1;
-    return (__u - __p.__areas_[__k]) / __p.__densities_[__k] + __p.__b_[__k];
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const piecewise_constant_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    size_t __n = __x.__p_.__b_.size();
-    __os << __n;
-    for (size_t __i = 0; __i < __n; ++__i)
-        __os << __sp << __x.__p_.__b_[__i];
-    __n = __x.__p_.__densities_.size();
-    __os << __sp << __n;
-    for (size_t __i = 0; __i < __n; ++__i)
-        __os << __sp << __x.__p_.__densities_[__i];
-    __n = __x.__p_.__areas_.size();
-    __os << __sp << __n;
-    for (size_t __i = 0; __i < __n; ++__i)
-        __os << __sp << __x.__p_.__areas_[__i];
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           piecewise_constant_distribution<_RT>& __x)
-{
-    typedef piecewise_constant_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    size_t __n;
-    __is >> __n;
-    vector<result_type> __b(__n);
-    for (size_t __i = 0; __i < __n; ++__i)
-        __is >> __b[__i];
-    __is >> __n;
-    vector<result_type> __densities(__n);
-    for (size_t __i = 0; __i < __n; ++__i)
-        __is >> __densities[__i];
-    __is >> __n;
-    vector<result_type> __areas(__n);
-    for (size_t __i = 0; __i < __n; ++__i)
-        __is >> __areas[__i];
-    if (!__is.fail())
-    {
-        swap(__x.__p_.__b_, __b);
-        swap(__x.__p_.__densities_, __densities);
-        swap(__x.__p_.__areas_, __areas);
-    }
-    return __is;
-}
-
-// piecewise_linear_distribution
-
-template<class _RealType = double>
-class _LIBCPP_TEMPLATE_VIS piecewise_linear_distribution
-{
-public:
-    // types
-    typedef _RealType result_type;
-
-    class _LIBCPP_TEMPLATE_VIS param_type
-    {
-        vector<result_type> __b_;
-        vector<result_type> __densities_;
-        vector<result_type> __areas_;
-    public:
-        typedef piecewise_linear_distribution distribution_type;
-
-        param_type();
-        template<class _InputIteratorB, class _InputIteratorW>
-            param_type(_InputIteratorB __fB, _InputIteratorB __lB,
-                       _InputIteratorW __fW);
-#ifndef _LIBCPP_CXX03_LANG
-        template<class _UnaryOperation>
-            param_type(initializer_list<result_type> __bl, _UnaryOperation __fw);
-#endif  // _LIBCPP_CXX03_LANG
-        template<class _UnaryOperation>
-            param_type(size_t __nw, result_type __xmin, result_type __xmax,
-                       _UnaryOperation __fw);
-        param_type & operator=(const param_type& __rhs);
-        
-        _LIBCPP_INLINE_VISIBILITY
-        vector<result_type> intervals() const {return __b_;}
-        _LIBCPP_INLINE_VISIBILITY
-        vector<result_type> densities() const {return __densities_;}
-
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator==(const param_type& __x, const param_type& __y)
-            {return __x.__densities_ == __y.__densities_ && __x.__b_ == __y.__b_;}
-        friend _LIBCPP_INLINE_VISIBILITY
-            bool operator!=(const param_type& __x, const param_type& __y)
-            {return !(__x == __y);}
-
-    private:
-        void __init();
-
-        friend class piecewise_linear_distribution;
-
-        template <class _CharT, class _Traits, class _RT>
-        friend
-        basic_ostream<_CharT, _Traits>&
-        operator<<(basic_ostream<_CharT, _Traits>& __os,
-                   const piecewise_linear_distribution<_RT>& __x);
-
-        template <class _CharT, class _Traits, class _RT>
-        friend
-        basic_istream<_CharT, _Traits>&
-        operator>>(basic_istream<_CharT, _Traits>& __is,
-                   piecewise_linear_distribution<_RT>& __x);
-    };
-
-private:
-    param_type __p_;
-
-public:
-    // constructor and reset functions
-    _LIBCPP_INLINE_VISIBILITY
-    piecewise_linear_distribution() {}
-    template<class _InputIteratorB, class _InputIteratorW>
-        _LIBCPP_INLINE_VISIBILITY
-        piecewise_linear_distribution(_InputIteratorB __fB,
-                                      _InputIteratorB __lB,
-                                      _InputIteratorW __fW)
-        : __p_(__fB, __lB, __fW) {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    template<class _UnaryOperation>
-        _LIBCPP_INLINE_VISIBILITY
-        piecewise_linear_distribution(initializer_list<result_type> __bl,
-                                      _UnaryOperation __fw)
-        : __p_(__bl, __fw) {}
-#endif  // _LIBCPP_CXX03_LANG
-
-    template<class _UnaryOperation>
-        _LIBCPP_INLINE_VISIBILITY
-        piecewise_linear_distribution(size_t __nw, result_type __xmin,
-                                      result_type __xmax, _UnaryOperation __fw)
-        : __p_(__nw, __xmin, __xmax, __fw) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit piecewise_linear_distribution(const param_type& __p)
-        : __p_(__p) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void reset() {}
-
-    // generating functions
-    template<class _URNG>
-        _LIBCPP_INLINE_VISIBILITY
-        result_type operator()(_URNG& __g)
-        {return (*this)(__g, __p_);}
-    template<class _URNG> result_type operator()(_URNG& __g, const param_type& __p);
-
-    // property functions
-    _LIBCPP_INLINE_VISIBILITY
-    vector<result_type> intervals() const {return __p_.intervals();}
-    _LIBCPP_INLINE_VISIBILITY
-    vector<result_type> densities() const {return __p_.densities();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    param_type param() const {return __p_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void param(const param_type& __p) {__p_ = __p;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const {return __p_.__b_.front();}
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const {return __p_.__b_.back();}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const piecewise_linear_distribution& __x,
-                        const piecewise_linear_distribution& __y)
-        {return __x.__p_ == __y.__p_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const piecewise_linear_distribution& __x,
-                        const piecewise_linear_distribution& __y)
-        {return !(__x == __y);}
-
-    template <class _CharT, class _Traits, class _RT>
-    friend
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os,
-               const piecewise_linear_distribution<_RT>& __x);
-
-    template <class _CharT, class _Traits, class _RT>
-    friend
-    basic_istream<_CharT, _Traits>&
-    operator>>(basic_istream<_CharT, _Traits>& __is,
-               piecewise_linear_distribution<_RT>& __x);
-};
-
-template<class _RealType>
-typename piecewise_linear_distribution<_RealType>::param_type &
-piecewise_linear_distribution<_RealType>::param_type::operator=
-                                                       (const param_type& __rhs)
-{
-//  These can throw
-    __b_.reserve        (__rhs.__b_.size ());
-    __densities_.reserve(__rhs.__densities_.size());
-    __areas_.reserve    (__rhs.__areas_.size());
-
-//  These can not throw
-    __b_         = __rhs.__b_;
-    __densities_ = __rhs.__densities_;
-    __areas_     =  __rhs.__areas_;
-    return *this;
-}
-
-
-template<class _RealType>
-void
-piecewise_linear_distribution<_RealType>::param_type::__init()
-{
-    __areas_.assign(__densities_.size() - 1, result_type());
-    result_type _Sp = 0;
-    for (size_t __i = 0; __i < __areas_.size(); ++__i)
-    {
-        __areas_[__i] = (__densities_[__i+1] + __densities_[__i]) *
-                        (__b_[__i+1] - __b_[__i]) * .5;
-        _Sp += __areas_[__i];
-    }
-    for (size_t __i = __areas_.size(); __i > 1;)
-    {
-        --__i;
-        __areas_[__i] = __areas_[__i-1] / _Sp;
-    }
-    __areas_[0] = 0;
-    for (size_t __i = 1; __i < __areas_.size(); ++__i)
-        __areas_[__i] += __areas_[__i-1];
-    for (size_t __i = 0; __i < __densities_.size(); ++__i)
-        __densities_[__i] /= _Sp;
-}
-
-template<class _RealType>
-piecewise_linear_distribution<_RealType>::param_type::param_type()
-    : __b_(2),
-      __densities_(2, 1.0),
-      __areas_(1, 0.0)
-{
-    __b_[1] = 1;
-}
-
-template<class _RealType>
-template<class _InputIteratorB, class _InputIteratorW>
-piecewise_linear_distribution<_RealType>::param_type::param_type(
-        _InputIteratorB __fB, _InputIteratorB __lB, _InputIteratorW __fW)
-    : __b_(__fB, __lB)
-{
-    if (__b_.size() < 2)
-    {
-        __b_.resize(2);
-        __b_[0] = 0;
-        __b_[1] = 1;
-        __densities_.assign(2, 1.0);
-        __areas_.assign(1, 0.0);
-    }
-    else
-    {
-        __densities_.reserve(__b_.size());
-        for (size_t __i = 0; __i < __b_.size(); ++__i, ++__fW)
-            __densities_.push_back(*__fW);
-        __init();
-    }
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _RealType>
-template<class _UnaryOperation>
-piecewise_linear_distribution<_RealType>::param_type::param_type(
-        initializer_list<result_type> __bl, _UnaryOperation __fw)
-    : __b_(__bl.begin(), __bl.end())
-{
-    if (__b_.size() < 2)
-    {
-        __b_.resize(2);
-        __b_[0] = 0;
-        __b_[1] = 1;
-        __densities_.assign(2, 1.0);
-        __areas_.assign(1, 0.0);
-    }
-    else
-    {
-        __densities_.reserve(__b_.size());
-        for (size_t __i = 0; __i < __b_.size(); ++__i)
-            __densities_.push_back(__fw(__b_[__i]));
-        __init();
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template<class _RealType>
-template<class _UnaryOperation>
-piecewise_linear_distribution<_RealType>::param_type::param_type(
-        size_t __nw, result_type __xmin, result_type __xmax, _UnaryOperation __fw)
-    : __b_(__nw == 0 ? 2 : __nw + 1)
-{
-    size_t __n = __b_.size() - 1;
-    result_type __d = (__xmax - __xmin) / __n;
-    __densities_.reserve(__b_.size());
-    for (size_t __i = 0; __i < __n; ++__i)
-    {
-        __b_[__i] = __xmin + __i * __d;
-        __densities_.push_back(__fw(__b_[__i]));
-    }
-    __b_[__n] = __xmax;
-    __densities_.push_back(__fw(__b_[__n]));
-    __init();
-}
-
-template<class _RealType>
-template<class _URNG>
-_RealType
-piecewise_linear_distribution<_RealType>::operator()(_URNG& __g, const param_type& __p)
-{
-    typedef uniform_real_distribution<result_type> _Gen;
-    result_type __u = _Gen()(__g);
-    ptrdiff_t __k = _VSTD::upper_bound(__p.__areas_.begin(), __p.__areas_.end(),
-                                      __u) - __p.__areas_.begin() - 1;
-    __u -= __p.__areas_[__k];
-    const result_type __dk = __p.__densities_[__k];
-    const result_type __dk1 = __p.__densities_[__k+1];
-    const result_type __deltad = __dk1 - __dk;
-    const result_type __bk = __p.__b_[__k];
-    if (__deltad == 0)
-        return __u / __dk + __bk;
-    const result_type __bk1 = __p.__b_[__k+1];
-    const result_type __deltab = __bk1 - __bk;
-    return (__bk * __dk1 - __bk1 * __dk +
-        _VSTD::sqrt(__deltab * (__deltab * __dk * __dk + 2 * __deltad * __u))) /
-        __deltad;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const piecewise_linear_distribution<_RT>& __x)
-{
-    __save_flags<_CharT, _Traits> __lx(__os);
-    __os.flags(ios_base::dec | ios_base::left | ios_base::fixed |
-               ios_base::scientific);
-    _CharT __sp = __os.widen(' ');
-    __os.fill(__sp);
-    size_t __n = __x.__p_.__b_.size();
-    __os << __n;
-    for (size_t __i = 0; __i < __n; ++__i)
-        __os << __sp << __x.__p_.__b_[__i];
-    __n = __x.__p_.__densities_.size();
-    __os << __sp << __n;
-    for (size_t __i = 0; __i < __n; ++__i)
-        __os << __sp << __x.__p_.__densities_[__i];
-    __n = __x.__p_.__areas_.size();
-    __os << __sp << __n;
-    for (size_t __i = 0; __i < __n; ++__i)
-        __os << __sp << __x.__p_.__areas_[__i];
-    return __os;
-}
-
-template <class _CharT, class _Traits, class _RT>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           piecewise_linear_distribution<_RT>& __x)
-{
-    typedef piecewise_linear_distribution<_RT> _Eng;
-    typedef typename _Eng::result_type result_type;
-    __save_flags<_CharT, _Traits> __lx(__is);
-    __is.flags(ios_base::dec | ios_base::skipws);
-    size_t __n;
-    __is >> __n;
-    vector<result_type> __b(__n);
-    for (size_t __i = 0; __i < __n; ++__i)
-        __is >> __b[__i];
-    __is >> __n;
-    vector<result_type> __densities(__n);
-    for (size_t __i = 0; __i < __n; ++__i)
-        __is >> __densities[__i];
-    __is >> __n;
-    vector<result_type> __areas(__n);
-    for (size_t __i = 0; __i < __n; ++__i)
-        __is >> __areas[__i];
-    if (!__is.fail())
-    {
-        swap(__x.__p_.__b_, __b);
-        swap(__x.__p_.__densities_, __densities);
-        swap(__x.__p_.__areas_, __areas);
-    }
-    return __is;
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_RANDOM
diff --git a/lib/libcxx/include/ratio b/lib/libcxx/include/ratio
deleted file mode 100644
index 7ee5ec24517..00000000000
--- a/lib/libcxx/include/ratio
+++ /dev/null
@@ -1,533 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- ratio -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_RATIO
-#define _LIBCPP_RATIO
-
-/*
-    ratio synopsis
-
-namespace std
-{
-
-template <intmax_t N, intmax_t D = 1>
-class ratio
-{
-public:
-    static constexpr intmax_t num;
-    static constexpr intmax_t den;
-    typedef ratio<num, den> type;
-};
-
-// ratio arithmetic
-template <class R1, class R2> using ratio_add = ...;
-template <class R1, class R2> using ratio_subtract = ...;
-template <class R1, class R2> using ratio_multiply = ...;
-template <class R1, class R2> using ratio_divide = ...;
-
-// ratio comparison
-template <class R1, class R2> struct ratio_equal;
-template <class R1, class R2> struct ratio_not_equal;
-template <class R1, class R2> struct ratio_less;
-template <class R1, class R2> struct ratio_less_equal;
-template <class R1, class R2> struct ratio_greater;
-template <class R1, class R2> struct ratio_greater_equal;
-
-// convenience SI typedefs
-typedef ratio<1, 1000000000000000000000000> yocto;  // not supported
-typedef ratio<1,    1000000000000000000000> zepto;  // not supported
-typedef ratio<1,       1000000000000000000> atto;
-typedef ratio<1,          1000000000000000> femto;
-typedef ratio<1,             1000000000000> pico;
-typedef ratio<1,                1000000000> nano;
-typedef ratio<1,                   1000000> micro;
-typedef ratio<1,                      1000> milli;
-typedef ratio<1,                       100> centi;
-typedef ratio<1,                        10> deci;
-typedef ratio<                       10, 1> deca;
-typedef ratio<                      100, 1> hecto;
-typedef ratio<                     1000, 1> kilo;
-typedef ratio<                  1000000, 1> mega;
-typedef ratio<               1000000000, 1> giga;
-typedef ratio<            1000000000000, 1> tera;
-typedef ratio<         1000000000000000, 1> peta;
-typedef ratio<      1000000000000000000, 1> exa;
-typedef ratio<   1000000000000000000000, 1> zetta;  // not supported
-typedef ratio<1000000000000000000000000, 1> yotta;  // not supported
-
-  // 20.11.5, ratio comparison
-  template <class R1, class R2> inline constexpr bool ratio_equal_v
-    = ratio_equal<R1, R2>::value;                                       // C++17
-  template <class R1, class R2> inline constexpr bool ratio_not_equal_v
-    = ratio_not_equal<R1, R2>::value;                                   // C++17
-  template <class R1, class R2> inline constexpr bool ratio_less_v
-    = ratio_less<R1, R2>::value;                                        // C++17
-  template <class R1, class R2> inline constexpr bool ratio_less_equal_v
-    = ratio_less_equal<R1, R2>::value;                                  // C++17
-  template <class R1, class R2> inline constexpr bool ratio_greater_v
-    = ratio_greater<R1, R2>::value;                                     // C++17
-  template <class R1, class R2> inline constexpr bool ratio_greater_equal_v
-    = ratio_greater_equal<R1, R2>::value;                               // C++17
-}
-*/
-
-#include <__config>
-#include <cstdint>
-#include <climits>
-#include <type_traits>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// __static_gcd
-
-template <intmax_t _Xp, intmax_t _Yp>
-struct __static_gcd
-{
-    static const intmax_t value = __static_gcd<_Yp, _Xp % _Yp>::value;
-};
-
-template <intmax_t _Xp>
-struct __static_gcd<_Xp, 0>
-{
-    static const intmax_t value = _Xp;
-};
-
-template <>
-struct __static_gcd<0, 0>
-{
-    static const intmax_t value = 1;
-};
-
-// __static_lcm
-
-template <intmax_t _Xp, intmax_t _Yp>
-struct __static_lcm
-{
-    static const intmax_t value = _Xp / __static_gcd<_Xp, _Yp>::value * _Yp;
-};
-
-template <intmax_t _Xp>
-struct __static_abs
-{
-    static const intmax_t value = _Xp < 0 ? -_Xp : _Xp;
-};
-
-template <intmax_t _Xp>
-struct __static_sign
-{
-    static const intmax_t value = _Xp == 0 ? 0 : (_Xp < 0 ? -1 : 1);
-};
-
-template <intmax_t _Xp, intmax_t _Yp, intmax_t = __static_sign<_Yp>::value>
-class __ll_add;
-
-template <intmax_t _Xp, intmax_t _Yp>
-class __ll_add<_Xp, _Yp, 1>
-{
-    static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
-    static const intmax_t max = -min;
-
-    static_assert(_Xp <= max - _Yp, "overflow in __ll_add");
-public:
-    static const intmax_t value = _Xp + _Yp;
-};
-
-template <intmax_t _Xp, intmax_t _Yp>
-class __ll_add<_Xp, _Yp, 0>
-{
-public:
-    static const intmax_t value = _Xp;
-};
-
-template <intmax_t _Xp, intmax_t _Yp>
-class __ll_add<_Xp, _Yp, -1>
-{
-    static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
-    static const intmax_t max = -min;
-
-    static_assert(min - _Yp <= _Xp, "overflow in __ll_add");
-public:
-    static const intmax_t value = _Xp + _Yp;
-};
-
-template <intmax_t _Xp, intmax_t _Yp, intmax_t = __static_sign<_Yp>::value>
-class __ll_sub;
-
-template <intmax_t _Xp, intmax_t _Yp>
-class __ll_sub<_Xp, _Yp, 1>
-{
-    static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
-    static const intmax_t max = -min;
-
-    static_assert(min + _Yp <= _Xp, "overflow in __ll_sub");
-public:
-    static const intmax_t value = _Xp - _Yp;
-};
-
-template <intmax_t _Xp, intmax_t _Yp>
-class __ll_sub<_Xp, _Yp, 0>
-{
-public:
-    static const intmax_t value = _Xp;
-};
-
-template <intmax_t _Xp, intmax_t _Yp>
-class __ll_sub<_Xp, _Yp, -1>
-{
-    static const intmax_t min = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1)) + 1;
-    static const intmax_t max = -min;
-
-    static_assert(_Xp <= max + _Yp, "overflow in __ll_sub");
-public:
-    static const intmax_t value = _Xp - _Yp;
-};
-
-template <intmax_t _Xp, intmax_t _Yp>
-class __ll_mul
-{
-    static const intmax_t nan = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1));
-    static const intmax_t min = nan + 1;
-    static const intmax_t max = -min;
-    static const intmax_t __a_x = __static_abs<_Xp>::value;
-    static const intmax_t __a_y = __static_abs<_Yp>::value;
-
-    static_assert(_Xp != nan && _Yp != nan && __a_x <= max / __a_y, "overflow in __ll_mul");
-public:
-    static const intmax_t value = _Xp * _Yp;
-};
-
-template <intmax_t _Yp>
-class __ll_mul<0, _Yp>
-{
-public:
-    static const intmax_t value = 0;
-};
-
-template <intmax_t _Xp>
-class __ll_mul<_Xp, 0>
-{
-public:
-    static const intmax_t value = 0;
-};
-
-template <>
-class __ll_mul<0, 0>
-{
-public:
-    static const intmax_t value = 0;
-};
-
-// Not actually used but left here in case needed in future maintenance
-template <intmax_t _Xp, intmax_t _Yp>
-class __ll_div
-{
-    static const intmax_t nan = (1LL << (sizeof(intmax_t) * CHAR_BIT - 1));
-    static const intmax_t min = nan + 1;
-    static const intmax_t max = -min;
-
-    static_assert(_Xp != nan && _Yp != nan && _Yp != 0, "overflow in __ll_div");
-public:
-    static const intmax_t value = _Xp / _Yp;
-};
-
-template <intmax_t _Num, intmax_t _Den = 1>
-class _LIBCPP_TEMPLATE_VIS ratio
-{
-    static_assert(__static_abs<_Num>::value >= 0, "ratio numerator is out of range");
-    static_assert(_Den != 0, "ratio divide by 0");
-    static_assert(__static_abs<_Den>::value >  0, "ratio denominator is out of range");
-    static _LIBCPP_CONSTEXPR const intmax_t __na = __static_abs<_Num>::value;
-    static _LIBCPP_CONSTEXPR const intmax_t __da = __static_abs<_Den>::value;
-    static _LIBCPP_CONSTEXPR const intmax_t __s = __static_sign<_Num>::value * __static_sign<_Den>::value;
-    static _LIBCPP_CONSTEXPR const intmax_t __gcd = __static_gcd<__na, __da>::value;
-public:
-    static _LIBCPP_CONSTEXPR const intmax_t num = __s * __na / __gcd;
-    static _LIBCPP_CONSTEXPR const intmax_t den = __da / __gcd;
-
-    typedef ratio<num, den> type;
-};
-
-template <intmax_t _Num, intmax_t _Den>
-_LIBCPP_CONSTEXPR const intmax_t ratio<_Num, _Den>::num;
-
-template <intmax_t _Num, intmax_t _Den>
-_LIBCPP_CONSTEXPR const intmax_t ratio<_Num, _Den>::den;
-
-template <class _Tp>                    struct __is_ratio                     : false_type {};
-template <intmax_t _Num, intmax_t _Den> struct __is_ratio<ratio<_Num, _Den> > : true_type  {};
-
-typedef ratio<1LL, 1000000000000000000LL> atto;
-typedef ratio<1LL,    1000000000000000LL> femto;
-typedef ratio<1LL,       1000000000000LL> pico;
-typedef ratio<1LL,          1000000000LL> nano;
-typedef ratio<1LL,             1000000LL> micro;
-typedef ratio<1LL,                1000LL> milli;
-typedef ratio<1LL,                 100LL> centi;
-typedef ratio<1LL,                  10LL> deci;
-typedef ratio<                 10LL, 1LL> deca;
-typedef ratio<                100LL, 1LL> hecto;
-typedef ratio<               1000LL, 1LL> kilo;
-typedef ratio<            1000000LL, 1LL> mega;
-typedef ratio<         1000000000LL, 1LL> giga;
-typedef ratio<      1000000000000LL, 1LL> tera;
-typedef ratio<   1000000000000000LL, 1LL> peta;
-typedef ratio<1000000000000000000LL, 1LL> exa;
-
-template <class _R1, class _R2>
-struct __ratio_multiply
-{
-private:
-    static const intmax_t __gcd_n1_d2 = __static_gcd<_R1::num, _R2::den>::value;
-    static const intmax_t __gcd_d1_n2 = __static_gcd<_R1::den, _R2::num>::value;
-public:
-    typedef typename ratio
-        <
-            __ll_mul<_R1::num / __gcd_n1_d2, _R2::num / __gcd_d1_n2>::value,
-            __ll_mul<_R2::den / __gcd_n1_d2, _R1::den / __gcd_d1_n2>::value
-        >::type type;
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2> using ratio_multiply
-                                    = typename __ratio_multiply<_R1, _R2>::type;
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_multiply
-    : public __ratio_multiply<_R1, _R2>::type {};
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2>
-struct __ratio_divide
-{
-private:
-    static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
-    static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
-public:
-    typedef typename ratio
-        <
-            __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
-            __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
-        >::type type;
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2> using ratio_divide
-                                      = typename __ratio_divide<_R1, _R2>::type;
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_divide
-    : public __ratio_divide<_R1, _R2>::type {};
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2>
-struct __ratio_add
-{
-private:
-    static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
-    static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
-public:
-    typedef typename ratio_multiply
-        <
-            ratio<__gcd_n1_n2, _R1::den / __gcd_d1_d2>,
-            ratio
-            <
-                __ll_add
-                <
-                    __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
-                    __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
-                >::value,
-                _R2::den
-            >
-        >::type type;
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2> using ratio_add
-                                         = typename __ratio_add<_R1, _R2>::type;
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_add
-    : public __ratio_add<_R1, _R2>::type {};
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2>
-struct __ratio_subtract
-{
-private:
-    static const intmax_t __gcd_n1_n2 = __static_gcd<_R1::num, _R2::num>::value;
-    static const intmax_t __gcd_d1_d2 = __static_gcd<_R1::den, _R2::den>::value;
-public:
-    typedef typename ratio_multiply
-        <
-            ratio<__gcd_n1_n2, _R1::den / __gcd_d1_d2>,
-            ratio
-            <
-                __ll_sub
-                <
-                    __ll_mul<_R1::num / __gcd_n1_n2, _R2::den / __gcd_d1_d2>::value,
-                    __ll_mul<_R2::num / __gcd_n1_n2, _R1::den / __gcd_d1_d2>::value
-                >::value,
-                _R2::den
-            >
-        >::type type;
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2> using ratio_subtract
-                                    = typename __ratio_subtract<_R1, _R2>::type;
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_subtract
-    : public __ratio_subtract<_R1, _R2>::type {};
-
-#endif  // _LIBCPP_CXX03_LANG
-
-// ratio_equal
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_equal
-    : public _LIBCPP_BOOL_CONSTANT((_R1::num == _R2::num && _R1::den == _R2::den)) {};
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_not_equal
-    : public _LIBCPP_BOOL_CONSTANT((!ratio_equal<_R1, _R2>::value)) {};
-
-// ratio_less
-
-template <class _R1, class _R2, bool _Odd = false,
-          intmax_t _Q1 = _R1::num / _R1::den, intmax_t _M1 = _R1::num % _R1::den,
-          intmax_t _Q2 = _R2::num / _R2::den, intmax_t _M2 = _R2::num % _R2::den>
-struct __ratio_less1
-{
-    static const bool value = _Odd ? _Q2 < _Q1 : _Q1 < _Q2;
-};
-
-template <class _R1, class _R2, bool _Odd, intmax_t _Qp>
-struct __ratio_less1<_R1, _R2, _Odd, _Qp, 0, _Qp, 0>
-{
-    static const bool value = false;
-};
-
-template <class _R1, class _R2, bool _Odd, intmax_t _Qp, intmax_t _M2>
-struct __ratio_less1<_R1, _R2, _Odd, _Qp, 0, _Qp, _M2>
-{
-    static const bool value = !_Odd;
-};
-
-template <class _R1, class _R2, bool _Odd, intmax_t _Qp, intmax_t _M1>
-struct __ratio_less1<_R1, _R2, _Odd, _Qp, _M1, _Qp, 0>
-{
-    static const bool value = _Odd;
-};
-
-template <class _R1, class _R2, bool _Odd, intmax_t _Qp, intmax_t _M1,
-                                                        intmax_t _M2>
-struct __ratio_less1<_R1, _R2, _Odd, _Qp, _M1, _Qp, _M2>
-{
-    static const bool value = __ratio_less1<ratio<_R1::den, _M1>,
-                                            ratio<_R2::den, _M2>, !_Odd>::value;
-};
-
-template <class _R1, class _R2, intmax_t _S1 = __static_sign<_R1::num>::value,
-                                intmax_t _S2 = __static_sign<_R2::num>::value>
-struct __ratio_less
-{
-    static const bool value = _S1 < _S2;
-};
-
-template <class _R1, class _R2>
-struct __ratio_less<_R1, _R2, 1LL, 1LL>
-{
-    static const bool value = __ratio_less1<_R1, _R2>::value;
-};
-
-template <class _R1, class _R2>
-struct __ratio_less<_R1, _R2, -1LL, -1LL>
-{
-    static const bool value = __ratio_less1<ratio<-_R2::num, _R2::den>, ratio<-_R1::num, _R1::den> >::value;
-};
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_less
-    : public _LIBCPP_BOOL_CONSTANT((__ratio_less<_R1, _R2>::value)) {};
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_less_equal
-    : public _LIBCPP_BOOL_CONSTANT((!ratio_less<_R2, _R1>::value)) {};
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_greater
-    : public _LIBCPP_BOOL_CONSTANT((ratio_less<_R2, _R1>::value)) {};
-
-template <class _R1, class _R2>
-struct _LIBCPP_TEMPLATE_VIS ratio_greater_equal
-    : public _LIBCPP_BOOL_CONSTANT((!ratio_less<_R1, _R2>::value)) {};
-
-template <class _R1, class _R2>
-struct __ratio_gcd
-{
-    typedef ratio<__static_gcd<_R1::num, _R2::num>::value,
-                  __static_lcm<_R1::den, _R2::den>::value> type;
-};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _R1, class _R2>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_equal_v
-    = ratio_equal<_R1, _R2>::value;
-
-template <class _R1, class _R2>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_not_equal_v
-    = ratio_not_equal<_R1, _R2>::value;
-
-template <class _R1, class _R2>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_less_v
-    = ratio_less<_R1, _R2>::value;
-
-template <class _R1, class _R2>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_less_equal_v
-    = ratio_less_equal<_R1, _R2>::value;
-
-template <class _R1, class _R2>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_greater_v
-    = ratio_greater<_R1, _R2>::value;
-
-template <class _R1, class _R2>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool ratio_greater_equal_v
-    = ratio_greater_equal<_R1, _R2>::value;
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_RATIO
diff --git a/lib/libcxx/include/regex b/lib/libcxx/include/regex
deleted file mode 100644
index bd83d7c10ca..00000000000
--- a/lib/libcxx/include/regex
+++ /dev/null
@@ -1,6619 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- regex ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_REGEX
-#define _LIBCPP_REGEX
-
-/*
-    regex synopsis
-
-#include <initializer_list>
-
-namespace std
-{
-
-namespace regex_constants
-{
-
-emum syntax_option_type
-{
-    icase      = unspecified,
-    nosubs     = unspecified,
-    optimize   = unspecified,
-    collate    = unspecified,
-    ECMAScript = unspecified,
-    basic      = unspecified,
-    extended   = unspecified,
-    awk        = unspecified,
-    grep       = unspecified,
-    egrep      = unspecified
-};
-
-constexpr syntax_option_type operator~(syntax_option_type f);
-constexpr syntax_option_type operator&(syntax_option_type lhs, syntax_option_type rhs);
-constexpr syntax_option_type operator|(syntax_option_type lhs, syntax_option_type rhs);
-
-enum match_flag_type
-{
-    match_default     = 0,
-    match_not_bol     = unspecified,
-    match_not_eol     = unspecified,
-    match_not_bow     = unspecified,
-    match_not_eow     = unspecified,
-    match_any         = unspecified,
-    match_not_null    = unspecified,
-    match_continuous  = unspecified,
-    match_prev_avail  = unspecified,
-    format_default    = 0,
-    format_sed        = unspecified,
-    format_no_copy    = unspecified,
-    format_first_only = unspecified
-};
-
-constexpr match_flag_type operator~(match_flag_type f);
-constexpr match_flag_type operator&(match_flag_type lhs, match_flag_type rhs);
-constexpr match_flag_type operator|(match_flag_type lhs, match_flag_type rhs);
-
-enum error_type
-{
-    error_collate    = unspecified,
-    error_ctype      = unspecified,
-    error_escape     = unspecified,
-    error_backref    = unspecified,
-    error_brack      = unspecified,
-    error_paren      = unspecified,
-    error_brace      = unspecified,
-    error_badbrace   = unspecified,
-    error_range      = unspecified,
-    error_space      = unspecified,
-    error_badrepeat  = unspecified,
-    error_complexity = unspecified,
-    error_stack      = unspecified
-};
-
-}  // regex_constants
-
-class regex_error
-    : public runtime_error
-{
-public:
-    explicit regex_error(regex_constants::error_type ecode);
-    regex_constants::error_type code() const;
-};
-
-template <class charT>
-struct regex_traits
-{
-public:
-    typedef charT                   char_type;
-    typedef basic_string<char_type> string_type;
-    typedef locale                  locale_type;
-    typedef /bitmask_type/          char_class_type;
-
-    regex_traits();
-
-    static size_t length(const char_type* p);
-    charT translate(charT c) const;
-    charT translate_nocase(charT c) const;
-    template <class ForwardIterator>
-        string_type
-        transform(ForwardIterator first, ForwardIterator last) const;
-    template <class ForwardIterator>
-        string_type
-        transform_primary( ForwardIterator first, ForwardIterator last) const;
-    template <class ForwardIterator>
-        string_type
-        lookup_collatename(ForwardIterator first, ForwardIterator last) const;
-    template <class ForwardIterator>
-        char_class_type
-        lookup_classname(ForwardIterator first, ForwardIterator last,
-                         bool icase = false) const;
-    bool isctype(charT c, char_class_type f) const;
-    int value(charT ch, int radix) const;
-    locale_type imbue(locale_type l);
-    locale_type getloc()const;
-};
-
-template <class charT, class traits = regex_traits<charT>>
-class basic_regex
-{
-public:
-    // types:
-    typedef charT                               value_type;
-    typedef traits                              traits_type;
-    typedef typename traits::string_type        string_type;
-    typedef regex_constants::syntax_option_type flag_type;
-    typedef typename traits::locale_type        locale_type;
-
-    // constants:
-    static constexpr regex_constants::syntax_option_type icase = regex_constants::icase;
-    static constexpr regex_constants::syntax_option_type nosubs = regex_constants::nosubs;
-    static constexpr regex_constants::syntax_option_type optimize = regex_constants::optimize;
-    static constexpr regex_constants::syntax_option_type collate = regex_constants::collate;
-    static constexpr regex_constants::syntax_option_type ECMAScript = regex_constants::ECMAScript;
-    static constexpr regex_constants::syntax_option_type basic = regex_constants::basic;
-    static constexpr regex_constants::syntax_option_type extended = regex_constants::extended;
-    static constexpr regex_constants::syntax_option_type awk = regex_constants::awk;
-    static constexpr regex_constants::syntax_option_type grep = regex_constants::grep;
-    static constexpr regex_constants::syntax_option_type egrep = regex_constants::egrep;
-
-    // construct/copy/destroy:
-    basic_regex();
-    explicit basic_regex(const charT* p, flag_type f = regex_constants::ECMAScript);
-    basic_regex(const charT* p, size_t len, flag_type f = regex_constants::ECMAScript);
-    basic_regex(const basic_regex&);
-    basic_regex(basic_regex&&) noexcept;
-    template <class ST, class SA>
-        explicit basic_regex(const basic_string<charT, ST, SA>& p,
-                             flag_type f = regex_constants::ECMAScript);
-    template <class ForwardIterator>
-        basic_regex(ForwardIterator first, ForwardIterator last,
-                    flag_type f = regex_constants::ECMAScript);
-    basic_regex(initializer_list<charT>, flag_type = regex_constants::ECMAScript);
-
-    ~basic_regex();
-
-    basic_regex& operator=(const basic_regex&);
-    basic_regex& operator=(basic_regex&&) noexcept;
-    basic_regex& operator=(const charT* ptr);
-    basic_regex& operator=(initializer_list<charT> il);
-    template <class ST, class SA>
-        basic_regex& operator=(const basic_string<charT, ST, SA>& p);
-
-    // assign:
-    basic_regex& assign(const basic_regex& that);
-    basic_regex& assign(basic_regex&& that) noexcept;
-    basic_regex& assign(const charT* ptr, flag_type f = regex_constants::ECMAScript);
-    basic_regex& assign(const charT* p, size_t len, flag_type f);
-    template <class string_traits, class A>
-        basic_regex& assign(const basic_string<charT, string_traits, A>& s,
-                            flag_type f = regex_constants::ECMAScript);
-    template <class InputIterator>
-        basic_regex& assign(InputIterator first, InputIterator last,
-                            flag_type f = regex_constants::ECMAScript);
-    basic_regex& assign(initializer_list<charT>, flag_type = regex_constants::ECMAScript);
-
-    // const operations:
-    unsigned mark_count() const;
-    flag_type flags() const;
-
-    // locale:
-    locale_type imbue(locale_type loc);
-    locale_type getloc() const;
-
-    // swap:
-    void swap(basic_regex&);
-};
-
-template<class ForwardIterator>
-basic_regex(ForwardIterator, ForwardIterator,
-            regex_constants::syntax_option_type = regex_constants::ECMAScript)
-    -> basic_regex<typename iterator_traits<ForwardIterator>::value_type>; // C++17
-
-typedef basic_regex<char>    regex;
-typedef basic_regex<wchar_t> wregex;
-
-template <class charT, class traits>
-    void swap(basic_regex<charT, traits>& e1, basic_regex<charT, traits>& e2);
-
-template <class BidirectionalIterator>
-class sub_match
-    : public pair<BidirectionalIterator, BidirectionalIterator>
-{
-public:
-    typedef typename iterator_traits<BidirectionalIterator>::value_type value_type;
-    typedef typename iterator_traits<BidirectionalIterator>::difference_type difference_type;
-    typedef BidirectionalIterator                                      iterator;
-    typedef basic_string<value_type>                                string_type;
-
-    bool matched;
-
-    constexpr sub_match();
-
-    difference_type length() const;
-    operator string_type() const;
-    string_type str() const;
-
-    int compare(const sub_match& s) const;
-    int compare(const string_type& s) const;
-    int compare(const value_type* s) const;
-};
-
-typedef sub_match<const char*>             csub_match;
-typedef sub_match<const wchar_t*>          wcsub_match;
-typedef sub_match<string::const_iterator>  ssub_match;
-typedef sub_match<wstring::const_iterator> wssub_match;
-
-template <class BiIter>
-    bool
-    operator==(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator!=(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator<(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator<=(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator>=(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator>(const sub_match<BiIter>& lhs, const sub_match<BiIter>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator==(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator!=(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator<(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-              const sub_match<BiIter>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator>(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-              const sub_match<BiIter>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool operator>=(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-                    const sub_match<BiIter>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator<=(const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator==(const sub_match<BiIter>& lhs,
-               const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator!=(const sub_match<BiIter>& lhs,
-               const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator<(const sub_match<BiIter>& lhs,
-              const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool operator>(const sub_match<BiIter>& lhs,
-                   const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator>=(const sub_match<BiIter>& lhs,
-               const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
-template <class BiIter, class ST, class SA>
-    bool
-    operator<=(const sub_match<BiIter>& lhs,
-               const basic_string<typename iterator_traits<BiIter>::value_type, ST, SA>& rhs);
-
-template <class BiIter>
-    bool
-    operator==(typename iterator_traits<BiIter>::value_type const* lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator!=(typename iterator_traits<BiIter>::value_type const* lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator<(typename iterator_traits<BiIter>::value_type const* lhs,
-              const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator>(typename iterator_traits<BiIter>::value_type const* lhs,
-              const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator>=(typename iterator_traits<BiIter>::value_type const* lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator<=(typename iterator_traits<BiIter>::value_type const* lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator==(const sub_match<BiIter>& lhs,
-               typename iterator_traits<BiIter>::value_type const* rhs);
-
-template <class BiIter>
-    bool
-    operator!=(const sub_match<BiIter>& lhs,
-               typename iterator_traits<BiIter>::value_type const* rhs);
-
-template <class BiIter>
-    bool
-    operator<(const sub_match<BiIter>& lhs,
-              typename iterator_traits<BiIter>::value_type const* rhs);
-
-template <class BiIter>
-    bool
-    operator>(const sub_match<BiIter>& lhs,
-              typename iterator_traits<BiIter>::value_type const* rhs);
-
-template <class BiIter>
-    bool
-    operator>=(const sub_match<BiIter>& lhs,
-               typename iterator_traits<BiIter>::value_type const* rhs);
-
-template <class BiIter>
-    bool
-    operator<=(const sub_match<BiIter>& lhs,
-               typename iterator_traits<BiIter>::value_type const* rhs);
-
-template <class BiIter>
-    bool
-    operator==(typename iterator_traits<BiIter>::value_type const& lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator!=(typename iterator_traits<BiIter>::value_type const& lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator<(typename iterator_traits<BiIter>::value_type const& lhs,
-              const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator>(typename iterator_traits<BiIter>::value_type const& lhs,
-              const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator>=(typename iterator_traits<BiIter>::value_type const& lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator<=(typename iterator_traits<BiIter>::value_type const& lhs,
-               const sub_match<BiIter>& rhs);
-
-template <class BiIter>
-    bool
-    operator==(const sub_match<BiIter>& lhs,
-               typename iterator_traits<BiIter>::value_type const& rhs);
-
-template <class BiIter>
-    bool
-    operator!=(const sub_match<BiIter>& lhs,
-               typename iterator_traits<BiIter>::value_type const& rhs);
-
-template <class BiIter>
-    bool
-    operator<(const sub_match<BiIter>& lhs,
-              typename iterator_traits<BiIter>::value_type const& rhs);
-
-template <class BiIter>
-    bool
-    operator>(const sub_match<BiIter>& lhs,
-              typename iterator_traits<BiIter>::value_type const& rhs);
-
-template <class BiIter>
-    bool
-    operator>=(const sub_match<BiIter>& lhs,
-               typename iterator_traits<BiIter>::value_type const& rhs);
-
-template <class BiIter>
-    bool
-    operator<=(const sub_match<BiIter>& lhs,
-               typename iterator_traits<BiIter>::value_type const& rhs);
-
-template <class charT, class ST, class BiIter>
-    basic_ostream<charT, ST>&
-    operator<<(basic_ostream<charT, ST>& os, const sub_match<BiIter>& m);
-
-template <class BidirectionalIterator,
-          class Allocator = allocator<sub_match<BidirectionalIterator>>>
-class match_results
-{
-public:
-    typedef sub_match<BidirectionalIterator>                  value_type;
-    typedef const value_type&                                 const_reference;
-    typedef value_type&                                       reference;
-    typedef /implementation-defined/                          const_iterator;
-    typedef const_iterator                                    iterator;
-    typedef typename iterator_traits<BidirectionalIterator>::difference_type difference_type;
-    typedef typename allocator_traits<Allocator>::size_type   size_type;
-    typedef Allocator                                         allocator_type;
-    typedef typename iterator_traits<BidirectionalIterator>::value_type char_type;
-    typedef basic_string<char_type>                           string_type;
-
-    // construct/copy/destroy:
-    explicit match_results(const Allocator& a = Allocator());
-    match_results(const match_results& m);
-    match_results(match_results&& m) noexcept;
-    match_results& operator=(const match_results& m);
-    match_results& operator=(match_results&& m);
-    ~match_results();
-
-    bool ready() const;
-
-    // size:
-    size_type size() const;
-    size_type max_size() const;
-    bool empty() const;
-
-    // element access:
-    difference_type length(size_type sub = 0) const;
-    difference_type position(size_type sub = 0) const;
-    string_type str(size_type sub = 0) const;
-    const_reference operator[](size_type n) const;
-
-    const_reference prefix() const;
-    const_reference suffix() const;
-
-    const_iterator begin() const;
-    const_iterator end() const;
-    const_iterator cbegin() const;
-    const_iterator cend() const;
-
-    // format:
-    template <class OutputIter>
-        OutputIter
-        format(OutputIter out, const char_type* fmt_first,
-               const char_type* fmt_last,
-               regex_constants::match_flag_type flags = regex_constants::format_default) const;
-    template <class OutputIter, class ST, class SA>
-        OutputIter
-        format(OutputIter out, const basic_string<char_type, ST, SA>& fmt,
-               regex_constants::match_flag_type flags = regex_constants::format_default) const;
-    template <class ST, class SA>
-        basic_string<char_type, ST, SA>
-        format(const basic_string<char_type, ST, SA>& fmt,
-               regex_constants::match_flag_type flags = regex_constants::format_default) const;
-    string_type
-        format(const char_type* fmt,
-               regex_constants::match_flag_type flags = regex_constants::format_default) const;
-
-    // allocator:
-    allocator_type get_allocator() const;
-
-    // swap:
-    void swap(match_results& that);
-};
-
-typedef match_results<const char*>             cmatch;
-typedef match_results<const wchar_t*>          wcmatch;
-typedef match_results<string::const_iterator>  smatch;
-typedef match_results<wstring::const_iterator> wsmatch;
-
-template <class BidirectionalIterator, class Allocator>
-    bool
-    operator==(const match_results<BidirectionalIterator, Allocator>& m1,
-               const match_results<BidirectionalIterator, Allocator>& m2);
-
-template <class BidirectionalIterator, class Allocator>
-    bool
-    operator!=(const match_results<BidirectionalIterator, Allocator>& m1,
-               const match_results<BidirectionalIterator, Allocator>& m2);
-
-template <class BidirectionalIterator, class Allocator>
-    void
-    swap(match_results<BidirectionalIterator, Allocator>& m1,
-         match_results<BidirectionalIterator, Allocator>& m2);
-
-template <class BidirectionalIterator, class Allocator, class charT, class traits>
-    bool
-    regex_match(BidirectionalIterator first, BidirectionalIterator last,
-                match_results<BidirectionalIterator, Allocator>& m,
-                const basic_regex<charT, traits>& e,
-                regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class BidirectionalIterator, class charT, class traits>
-    bool
-    regex_match(BidirectionalIterator first, BidirectionalIterator last,
-                const basic_regex<charT, traits>& e,
-                regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class charT, class Allocator, class traits>
-    bool
-    regex_match(const charT* str, match_results<const charT*, Allocator>& m,
-                const basic_regex<charT, traits>& e,
-                regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class ST, class SA, class Allocator, class charT, class traits>
-    bool
-    regex_match(const basic_string<charT, ST, SA>& s,
-                match_results<typename basic_string<charT, ST, SA>::const_iterator, Allocator>& m,
-                const basic_regex<charT, traits>& e,
-                regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class ST, class SA, class Allocator, class charT, class traits>
-    bool
-    regex_match(const basic_string<charT, ST, SA>&& s,
-                match_results<typename basic_string<charT, ST, SA>::const_iterator, Allocator>& m,
-                const basic_regex<charT, traits>& e,
-                regex_constants::match_flag_type flags = regex_constants::match_default) = delete; // C++14
-
-template <class charT, class traits>
-    bool
-    regex_match(const charT* str, const basic_regex<charT, traits>& e,
-                regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class ST, class SA, class charT, class traits>
-    bool
-    regex_match(const basic_string<charT, ST, SA>& s,
-                const basic_regex<charT, traits>& e,
-                regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class BidirectionalIterator, class Allocator, class charT, class traits>
-    bool
-    regex_search(BidirectionalIterator first, BidirectionalIterator last,
-                 match_results<BidirectionalIterator, Allocator>& m,
-                 const basic_regex<charT, traits>& e,
-                 regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class BidirectionalIterator, class charT, class traits>
-    bool
-    regex_search(BidirectionalIterator first, BidirectionalIterator last,
-                 const basic_regex<charT, traits>& e,
-                 regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class charT, class Allocator, class traits>
-    bool
-    regex_search(const charT* str, match_results<const charT*, Allocator>& m,
-                 const basic_regex<charT, traits>& e,
-                 regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class charT, class traits>
-    bool
-    regex_search(const charT* str, const basic_regex<charT, traits>& e,
-                 regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class ST, class SA, class charT, class traits>
-    bool
-    regex_search(const basic_string<charT, ST, SA>& s,
-                 const basic_regex<charT, traits>& e,
-                 regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class ST, class SA, class Allocator, class charT, class traits>
-    bool
-    regex_search(const basic_string<charT, ST, SA>& s,
-                 match_results<typename basic_string<charT, ST, SA>::const_iterator, Allocator>& m,
-                 const basic_regex<charT, traits>& e,
-                 regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class ST, class SA, class Allocator, class charT, class traits>
-    bool
-    regex_search(const basic_string<charT, ST, SA>&& s,
-                 match_results<typename basic_string<charT, ST, SA>::const_iterator, Allocator>& m,
-                 const basic_regex<charT, traits>& e,
-                 regex_constants::match_flag_type flags = regex_constants::match_default) = delete; // C++14
-
-template <class OutputIterator, class BidirectionalIterator,
-          class traits, class charT, class ST, class SA>
-    OutputIterator
-    regex_replace(OutputIterator out,
-                  BidirectionalIterator first, BidirectionalIterator last,
-                  const basic_regex<charT, traits>& e,
-                  const basic_string<charT, ST, SA>& fmt,
-                  regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class OutputIterator, class BidirectionalIterator,
-          class traits, class charT>
-    OutputIterator
-    regex_replace(OutputIterator out,
-                  BidirectionalIterator first, BidirectionalIterator last,
-                  const basic_regex<charT, traits>& e, const charT* fmt,
-                  regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class traits, class charT, class ST, class SA, class FST, class FSA>>
-    basic_string<charT, ST, SA>
-    regex_replace(const basic_string<charT, ST, SA>& s,
-                  const basic_regex<charT, traits>& e,
-                  const basic_string<charT, FST, FSA>& fmt,
-                  regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class traits, class charT, class ST, class SA>
-    basic_string<charT, ST, SA>
-    regex_replace(const basic_string<charT, ST, SA>& s,
-                  const basic_regex<charT, traits>& e, const charT* fmt,
-                  regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class traits, class charT, class ST, class SA>
-    basic_string<charT>
-    regex_replace(const charT* s,
-                  const basic_regex<charT, traits>& e,
-                  const basic_string<charT, ST, SA>& fmt,
-                  regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class traits, class charT>
-    basic_string<charT>
-    regex_replace(const charT* s,
-                  const basic_regex<charT, traits>& e,
-                  const charT* fmt,
-                  regex_constants::match_flag_type flags = regex_constants::match_default);
-
-template <class BidirectionalIterator,
-          class charT = typename iterator_traits< BidirectionalIterator>::value_type,
-          class traits = regex_traits<charT>>
-class regex_iterator
-{
-public:
-    typedef basic_regex<charT, traits>           regex_type;
-    typedef match_results<BidirectionalIterator> value_type;
-    typedef ptrdiff_t                            difference_type;
-    typedef const value_type*                    pointer;
-    typedef const value_type&                    reference;
-    typedef forward_iterator_tag                 iterator_category;
-
-    regex_iterator();
-    regex_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                   const regex_type& re,
-                   regex_constants::match_flag_type m = regex_constants::match_default);
-    regex_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                   const regex_type&& __re,
-                   regex_constants::match_flag_type __m 
-                                     = regex_constants::match_default) = delete; // C++14
-    regex_iterator(const regex_iterator&);
-    regex_iterator& operator=(const regex_iterator&);
-
-    bool operator==(const regex_iterator&) const;
-    bool operator!=(const regex_iterator&) const;
-
-    const value_type& operator*() const;
-    const value_type* operator->() const;
-
-    regex_iterator& operator++();
-    regex_iterator operator++(int);
-};
-
-typedef regex_iterator<const char*>             cregex_iterator;
-typedef regex_iterator<const wchar_t*>          wcregex_iterator;
-typedef regex_iterator<string::const_iterator>  sregex_iterator;
-typedef regex_iterator<wstring::const_iterator> wsregex_iterator;
-
-template <class BidirectionalIterator,
-          class charT = typename iterator_traits< BidirectionalIterator>::value_type,
-          class traits = regex_traits<charT>>
-class regex_token_iterator
-{
-public:
-    typedef basic_regex<charT, traits>       regex_type;
-    typedef sub_match<BidirectionalIterator> value_type;
-    typedef ptrdiff_t                        difference_type;
-    typedef const value_type*                pointer;
-    typedef const value_type&                reference;
-    typedef forward_iterator_tag             iterator_category;
-
-    regex_token_iterator();
-    regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                         const regex_type& re, int submatch = 0,
-                         regex_constants::match_flag_type m = regex_constants::match_default);
-    regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                         const regex_type&& re, int submatch = 0,
-                         regex_constants::match_flag_type m = regex_constants::match_default) = delete; // C++14
-    regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                         const regex_type& re, const vector<int>& submatches,
-                         regex_constants::match_flag_type m = regex_constants::match_default);
-    regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                         const regex_type&& re, const vector<int>& submatches,
-                         regex_constants::match_flag_type m = regex_constants::match_default) = delete; // C++14
-    regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                         const regex_type& re, initializer_list<int> submatches,
-                         regex_constants::match_flag_type m = regex_constants::match_default);
-    regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                         const regex_type&& re, initializer_list<int> submatches,
-                         regex_constants::match_flag_type m = regex_constants::match_default) = delete; // C++14
-    template <size_t N>
-        regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                             const regex_type& re, const int (&submatches)[N],
-                             regex_constants::match_flag_type m = regex_constants::match_default);
-    template <size_t N>
-        regex_token_iterator(BidirectionalIterator a, BidirectionalIterator b,
-                             const regex_type& re, const int (&submatches)[N],
-                             regex_constants::match_flag_type m = regex_constants::match_default) = delete // C++14;
-    regex_token_iterator(const regex_token_iterator&);
-    regex_token_iterator& operator=(const regex_token_iterator&);
-
-    bool operator==(const regex_token_iterator&) const;
-    bool operator!=(const regex_token_iterator&) const;
-
-    const value_type& operator*() const;
-    const value_type* operator->() const;
-
-    regex_token_iterator& operator++();
-    regex_token_iterator operator++(int);
-};
-
-typedef regex_token_iterator<const char*>             cregex_token_iterator;
-typedef regex_token_iterator<const wchar_t*>          wcregex_token_iterator;
-typedef regex_token_iterator<string::const_iterator>  sregex_token_iterator;
-typedef regex_token_iterator<wstring::const_iterator> wsregex_token_iterator;
-
-} // std
-*/
-
-#include <__config>
-#include <stdexcept>
-#include <__locale>
-#include <initializer_list>
-#include <utility>
-#include <iterator>
-#include <string>
-#include <memory>
-#include <vector>
-#include <deque>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-#define _LIBCPP_REGEX_COMPLEXITY_FACTOR 4096
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-namespace regex_constants
-{
-
-// syntax_option_type
-
-enum syntax_option_type
-{
-    icase      = 1 << 0,
-    nosubs     = 1 << 1,
-    optimize   = 1 << 2,
-    collate    = 1 << 3,
-    ECMAScript = 0,
-    basic      = 1 << 4,
-    extended   = 1 << 5,
-    awk        = 1 << 6,
-    grep       = 1 << 7,
-    egrep      = 1 << 8
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-syntax_option_type
-operator~(syntax_option_type __x)
-{
-    return syntax_option_type(~int(__x) & 0x1FF);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-syntax_option_type
-operator&(syntax_option_type __x, syntax_option_type __y)
-{
-    return syntax_option_type(int(__x) & int(__y));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-syntax_option_type
-operator|(syntax_option_type __x, syntax_option_type __y)
-{
-    return syntax_option_type(int(__x) | int(__y));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-syntax_option_type
-operator^(syntax_option_type __x, syntax_option_type __y)
-{
-    return syntax_option_type(int(__x) ^ int(__y));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-syntax_option_type&
-operator&=(syntax_option_type& __x, syntax_option_type __y)
-{
-    __x = __x & __y;
-    return __x;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-syntax_option_type&
-operator|=(syntax_option_type& __x, syntax_option_type __y)
-{
-    __x = __x | __y;
-    return __x;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-syntax_option_type&
-operator^=(syntax_option_type& __x, syntax_option_type __y)
-{
-    __x = __x ^ __y;
-    return __x;
-}
-
-// match_flag_type
-
-enum match_flag_type
-{
-    match_default     = 0,
-    match_not_bol     = 1 << 0,
-    match_not_eol     = 1 << 1,
-    match_not_bow     = 1 << 2,
-    match_not_eow     = 1 << 3,
-    match_any         = 1 << 4,
-    match_not_null    = 1 << 5,
-    match_continuous  = 1 << 6,
-    match_prev_avail  = 1 << 7,
-    format_default    = 0,
-    format_sed        = 1 << 8,
-    format_no_copy    = 1 << 9,
-    format_first_only = 1 << 10,
-    __no_update_pos   = 1 << 11,
-    __full_match      = 1 << 12
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-match_flag_type
-operator~(match_flag_type __x)
-{
-    return match_flag_type(~int(__x) & 0x0FFF);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-match_flag_type
-operator&(match_flag_type __x, match_flag_type __y)
-{
-    return match_flag_type(int(__x) & int(__y));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-match_flag_type
-operator|(match_flag_type __x, match_flag_type __y)
-{
-    return match_flag_type(int(__x) | int(__y));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR
-match_flag_type
-operator^(match_flag_type __x, match_flag_type __y)
-{
-    return match_flag_type(int(__x) ^ int(__y));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-match_flag_type&
-operator&=(match_flag_type& __x, match_flag_type __y)
-{
-    __x = __x & __y;
-    return __x;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-match_flag_type&
-operator|=(match_flag_type& __x, match_flag_type __y)
-{
-    __x = __x | __y;
-    return __x;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-match_flag_type&
-operator^=(match_flag_type& __x, match_flag_type __y)
-{
-    __x = __x ^ __y;
-    return __x;
-}
-
-enum error_type
-{
-    error_collate = 1,
-    error_ctype,
-    error_escape,
-    error_backref,
-    error_brack,
-    error_paren,
-    error_brace,
-    error_badbrace,
-    error_range,
-    error_space,
-    error_badrepeat,
-    error_complexity,
-    error_stack,
-    __re_err_grammar,
-    __re_err_empty,
-    __re_err_unknown
-};
-
-}  // regex_constants
-
-class _LIBCPP_EXCEPTION_ABI regex_error
-    : public runtime_error
-{
-    regex_constants::error_type __code_;
-public:
-    explicit regex_error(regex_constants::error_type __ecode);
-    virtual ~regex_error() throw();
-     _LIBCPP_INLINE_VISIBILITY
-    regex_constants::error_type code() const {return __code_;}
-};
-
-template <regex_constants::error_type _Ev>
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_regex_error()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw regex_error(_Ev);
-#else
-    _VSTD::abort();
-#endif
-}
-
-template <class _CharT>
-struct _LIBCPP_TEMPLATE_VIS regex_traits
-{
-public:
-    typedef _CharT                  char_type;
-    typedef basic_string<char_type> string_type;
-    typedef locale                  locale_type;
-    typedef ctype_base::mask        char_class_type;
-
-#if defined(__mips__) && defined(__GLIBC__)
-    static const char_class_type __regex_word = static_cast<char_class_type>(_ISbit(15));
-#elif defined(__NetBSD__)
-    // NetBSD defines classes up to 0x2000
-    // see sys/ctype_bits.h, _CTYPE_Q
-    static const char_class_type __regex_word = 0x8000;
-#else
-    static const char_class_type __regex_word = 0x80;
-#endif
-
-private:
-    locale __loc_;
-    const ctype<char_type>* __ct_;
-    const collate<char_type>* __col_;
-
-public:
-    regex_traits();
-
-    _LIBCPP_INLINE_VISIBILITY
-    static size_t length(const char_type* __p)
-        {return char_traits<char_type>::length(__p);}
-    _LIBCPP_INLINE_VISIBILITY
-    char_type translate(char_type __c) const {return __c;}
-    char_type translate_nocase(char_type __c) const;
-    template <class _ForwardIterator>
-        string_type
-        transform(_ForwardIterator __f, _ForwardIterator __l) const;
-    template <class _ForwardIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        string_type
-        transform_primary( _ForwardIterator __f, _ForwardIterator __l) const
-            {return __transform_primary(__f, __l, char_type());}
-    template <class _ForwardIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        string_type
-        lookup_collatename(_ForwardIterator __f, _ForwardIterator __l) const
-            {return __lookup_collatename(__f, __l, char_type());}
-    template <class _ForwardIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        char_class_type
-        lookup_classname(_ForwardIterator __f, _ForwardIterator __l,
-                         bool __icase = false) const
-            {return __lookup_classname(__f, __l, __icase, char_type());}
-    bool isctype(char_type __c, char_class_type __m) const;
-    _LIBCPP_INLINE_VISIBILITY
-    int value(char_type __ch, int __radix) const
-        {return __regex_traits_value(__ch, __radix);}
-    locale_type imbue(locale_type __l);
-    _LIBCPP_INLINE_VISIBILITY
-    locale_type getloc()const {return __loc_;}
-
-private:
-    void __init();
-
-    template <class _ForwardIterator>
-        string_type
-        __transform_primary(_ForwardIterator __f, _ForwardIterator __l, char) const;
-    template <class _ForwardIterator>
-        string_type
-        __transform_primary(_ForwardIterator __f, _ForwardIterator __l, wchar_t) const;
-
-    template <class _ForwardIterator>
-        string_type
-        __lookup_collatename(_ForwardIterator __f, _ForwardIterator __l, char) const;
-    template <class _ForwardIterator>
-        string_type
-        __lookup_collatename(_ForwardIterator __f, _ForwardIterator __l, wchar_t) const;
-
-    template <class _ForwardIterator>
-        char_class_type
-        __lookup_classname(_ForwardIterator __f, _ForwardIterator __l,
-                           bool __icase, char) const;
-    template <class _ForwardIterator>
-        char_class_type
-        __lookup_classname(_ForwardIterator __f, _ForwardIterator __l,
-                           bool __icase, wchar_t) const;
-
-    static int __regex_traits_value(unsigned char __ch, int __radix);
-    _LIBCPP_INLINE_VISIBILITY
-    int __regex_traits_value(char __ch, int __radix) const
-        {return __regex_traits_value(static_cast<unsigned char>(__ch), __radix);}
-    _LIBCPP_INLINE_VISIBILITY
-    int __regex_traits_value(wchar_t __ch, int __radix) const;
-};
-
-template <class _CharT>
-const typename regex_traits<_CharT>::char_class_type
-regex_traits<_CharT>::__regex_word;
-
-template <class _CharT>
-regex_traits<_CharT>::regex_traits()
-{
-    __init();
-}
-
-template <class _CharT>
-typename regex_traits<_CharT>::char_type
-regex_traits<_CharT>::translate_nocase(char_type __c) const
-{
-    return __ct_->tolower(__c);
-}
-
-template <class _CharT>
-template <class _ForwardIterator>
-typename regex_traits<_CharT>::string_type
-regex_traits<_CharT>::transform(_ForwardIterator __f, _ForwardIterator __l) const
-{
-    string_type __s(__f, __l);
-    return __col_->transform(__s.data(), __s.data() + __s.size());
-}
-
-template <class _CharT>
-void
-regex_traits<_CharT>::__init()
-{
-    __ct_ = &use_facet<ctype<char_type> >(__loc_);
-    __col_ = &use_facet<collate<char_type> >(__loc_);
-}
-
-template <class _CharT>
-typename regex_traits<_CharT>::locale_type
-regex_traits<_CharT>::imbue(locale_type __l)
-{
-    locale __r = __loc_;
-    __loc_ = __l;
-    __init();
-    return __r;
-}
-
-// transform_primary is very FreeBSD-specific
-
-template <class _CharT>
-template <class _ForwardIterator>
-typename regex_traits<_CharT>::string_type
-regex_traits<_CharT>::__transform_primary(_ForwardIterator __f,
-                                          _ForwardIterator __l, char) const
-{
-    const string_type __s(__f, __l);
-    string_type __d = __col_->transform(__s.data(), __s.data() + __s.size());
-    switch (__d.size())
-    {
-    case 1:
-        break;
-    case 12:
-        __d[11] = __d[3];
-        break;
-    default:
-        __d.clear();
-        break;
-    }
-    return __d;
-}
-
-template <class _CharT>
-template <class _ForwardIterator>
-typename regex_traits<_CharT>::string_type
-regex_traits<_CharT>::__transform_primary(_ForwardIterator __f,
-                                          _ForwardIterator __l, wchar_t) const
-{
-    const string_type __s(__f, __l);
-    string_type __d = __col_->transform(__s.data(), __s.data() + __s.size());
-    switch (__d.size())
-    {
-    case 1:
-        break;
-    case 3:
-        __d[2] = __d[0];
-        break;
-    default:
-        __d.clear();
-        break;
-    }
-    return __d;
-}
-
-// lookup_collatename is very FreeBSD-specific
-
-_LIBCPP_FUNC_VIS string __get_collation_name(const char* __s);
-
-template <class _CharT>
-template <class _ForwardIterator>
-typename regex_traits<_CharT>::string_type
-regex_traits<_CharT>::__lookup_collatename(_ForwardIterator __f,
-                                           _ForwardIterator __l, char) const
-{
-    string_type __s(__f, __l);
-    string_type __r;
-    if (!__s.empty())
-    {
-        __r = __get_collation_name(__s.c_str());
-        if (__r.empty() && __s.size() <= 2)
-        {
-            __r = __col_->transform(__s.data(), __s.data() + __s.size());
-            if (__r.size() == 1 || __r.size() == 12)
-                __r = __s;
-            else
-                __r.clear();
-        }
-    }
-    return __r;
-}
-
-template <class _CharT>
-template <class _ForwardIterator>
-typename regex_traits<_CharT>::string_type
-regex_traits<_CharT>::__lookup_collatename(_ForwardIterator __f,
-                                           _ForwardIterator __l, wchar_t) const
-{
-    string_type __s(__f, __l);
-    string __n;
-    __n.reserve(__s.size());
-    for (typename string_type::const_iterator __i = __s.begin(), __e = __s.end();
-                                                              __i != __e; ++__i)
-    {
-        if (static_cast<unsigned>(*__i) >= 127)
-            return string_type();
-        __n.push_back(char(*__i));
-    }
-    string_type __r;
-    if (!__s.empty())
-    {
-        __n = __get_collation_name(__n.c_str());
-        if (!__n.empty())
-            __r.assign(__n.begin(), __n.end());
-        else if (__s.size() <= 2)
-        {
-            __r = __col_->transform(__s.data(), __s.data() + __s.size());
-            if (__r.size() == 1 || __r.size() == 3)
-                __r = __s;
-            else
-                __r.clear();
-        }
-    }
-    return __r;
-}
-
-// lookup_classname
-
-regex_traits<char>::char_class_type _LIBCPP_FUNC_VIS
-__get_classname(const char* __s, bool __icase);
-
-template <class _CharT>
-template <class _ForwardIterator>
-typename regex_traits<_CharT>::char_class_type
-regex_traits<_CharT>::__lookup_classname(_ForwardIterator __f,
-                                         _ForwardIterator __l,
-                                         bool __icase, char) const
-{
-    string_type __s(__f, __l);
-    __ct_->tolower(&__s[0], &__s[0] + __s.size());
-    return __get_classname(__s.c_str(), __icase);
-}
-
-template <class _CharT>
-template <class _ForwardIterator>
-typename regex_traits<_CharT>::char_class_type
-regex_traits<_CharT>::__lookup_classname(_ForwardIterator __f,
-                                         _ForwardIterator __l,
-                                         bool __icase, wchar_t) const
-{
-    string_type __s(__f, __l);
-    __ct_->tolower(&__s[0], &__s[0] + __s.size());
-    string __n;
-    __n.reserve(__s.size());
-    for (typename string_type::const_iterator __i = __s.begin(), __e = __s.end();
-                                                              __i != __e; ++__i)
-    {
-        if (static_cast<unsigned>(*__i) >= 127)
-            return char_class_type();
-        __n.push_back(char(*__i));
-    }
-    return __get_classname(__n.c_str(), __icase);
-}
-
-template <class _CharT>
-bool
-regex_traits<_CharT>::isctype(char_type __c, char_class_type __m) const
-{
-    if (__ct_->is(__m, __c))
-        return true;
-    return (__c == '_' && (__m & __regex_word));
-}
-
-template <class _CharT>
-int
-regex_traits<_CharT>::__regex_traits_value(unsigned char __ch, int __radix)
-{
-    if ((__ch & 0xF8u) == 0x30)  // '0' <= __ch && __ch <= '7'
-        return __ch - '0';
-    if (__radix != 8)
-    {
-        if ((__ch & 0xFEu) == 0x38)  // '8' <= __ch && __ch <= '9'
-            return __ch - '0';
-        if (__radix == 16)
-        {
-            __ch |= 0x20;  // tolower
-            if ('a' <= __ch && __ch <= 'f')
-                return __ch - ('a' - 10);
-        }
-    }
-    return -1;
-}
-
-template <class _CharT>
-inline
-int
-regex_traits<_CharT>::__regex_traits_value(wchar_t __ch, int __radix) const
-{
-    return __regex_traits_value(static_cast<unsigned char>(__ct_->narrow(__ch, char_type())), __radix);
-}
-
-template <class _CharT> class __node;
-
-template <class _BidirectionalIterator> class _LIBCPP_TEMPLATE_VIS sub_match;
-
-template <class _BidirectionalIterator,
-          class _Allocator = allocator<sub_match<_BidirectionalIterator> > >
-class _LIBCPP_TEMPLATE_VIS match_results;
-
-template <class _CharT>
-struct __state
-{
-    enum
-    {
-        __end_state = -1000,
-        __consume_input,  // -999
-        __begin_marked_expr, // -998
-        __end_marked_expr,   // -997
-        __pop_state,           // -996
-        __accept_and_consume,  // -995
-        __accept_but_not_consume,  // -994
-        __reject,                  // -993
-        __split,
-        __repeat
-    };
-
-    int __do_;
-    const _CharT* __first_;
-    const _CharT* __current_;
-    const _CharT* __last_;
-    vector<sub_match<const _CharT*> > __sub_matches_;
-    vector<pair<size_t, const _CharT*> > __loop_data_;
-    const __node<_CharT>* __node_;
-    regex_constants::match_flag_type __flags_;
-    bool __at_first_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __state()
-        : __do_(0), __first_(nullptr), __current_(nullptr), __last_(nullptr),
-          __node_(nullptr), __flags_() {}
-};
-
-// __node
-
-template <class _CharT>
-class __node
-{
-    __node(const __node&);
-    __node& operator=(const __node&);
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __node() {}
-    _LIBCPP_INLINE_VISIBILITY
-    virtual ~__node() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    virtual void __exec(__state&) const {}
-    _LIBCPP_INLINE_VISIBILITY
-    virtual void __exec_split(bool, __state&) const {}
-};
-
-// __end_state
-
-template <class _CharT>
-class __end_state
-    : public __node<_CharT>
-{
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __end_state() {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__end_state<_CharT>::__exec(__state& __s) const
-{
-    __s.__do_ = __state::__end_state;
-}
-
-// __has_one_state
-
-template <class _CharT>
-class __has_one_state
-    : public __node<_CharT>
-{
-    __node<_CharT>* __first_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __has_one_state(__node<_CharT>* __s)
-        : __first_(__s) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __node<_CharT>*  first() const {return __first_;}
-    _LIBCPP_INLINE_VISIBILITY
-    __node<_CharT>*& first()       {return __first_;}
-};
-
-// __owns_one_state
-
-template <class _CharT>
-class __owns_one_state
-    : public __has_one_state<_CharT>
-{
-    typedef __has_one_state<_CharT> base;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __owns_one_state(__node<_CharT>* __s)
-        : base(__s) {}
-
-    virtual ~__owns_one_state();
-};
-
-template <class _CharT>
-__owns_one_state<_CharT>::~__owns_one_state()
-{
-    delete this->first();
-}
-
-// __empty_state
-
-template <class _CharT>
-class __empty_state
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __empty_state(__node<_CharT>* __s)
-        : base(__s) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__empty_state<_CharT>::__exec(__state& __s) const
-{
-    __s.__do_ = __state::__accept_but_not_consume;
-    __s.__node_ = this->first();
-}
-
-// __empty_non_own_state
-
-template <class _CharT>
-class __empty_non_own_state
-    : public __has_one_state<_CharT>
-{
-    typedef __has_one_state<_CharT> base;
-
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __empty_non_own_state(__node<_CharT>* __s)
-        : base(__s) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__empty_non_own_state<_CharT>::__exec(__state& __s) const
-{
-    __s.__do_ = __state::__accept_but_not_consume;
-    __s.__node_ = this->first();
-}
-
-// __repeat_one_loop
-
-template <class _CharT>
-class __repeat_one_loop
-    : public __has_one_state<_CharT>
-{
-    typedef __has_one_state<_CharT> base;
-
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __repeat_one_loop(__node<_CharT>* __s)
-        : base(__s) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__repeat_one_loop<_CharT>::__exec(__state& __s) const
-{
-    __s.__do_ = __state::__repeat;
-    __s.__node_ = this->first();
-}
-
-// __owns_two_states
-
-template <class _CharT>
-class __owns_two_states
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    base* __second_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __owns_two_states(__node<_CharT>* __s1, base* __s2)
-        : base(__s1), __second_(__s2) {}
-
-    virtual ~__owns_two_states();
-
-    _LIBCPP_INLINE_VISIBILITY
-    base*  second() const {return __second_;}
-    _LIBCPP_INLINE_VISIBILITY
-    base*& second()       {return __second_;}
-};
-
-template <class _CharT>
-__owns_two_states<_CharT>::~__owns_two_states()
-{
-    delete __second_;
-}
-
-// __loop
-
-template <class _CharT>
-class __loop
-    : public __owns_two_states<_CharT>
-{
-    typedef __owns_two_states<_CharT> base;
-
-    size_t __min_;
-    size_t __max_;
-    unsigned __loop_id_;
-    unsigned __mexp_begin_;
-    unsigned __mexp_end_;
-    bool __greedy_;
-
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __loop(unsigned __loop_id,
-                          __node<_CharT>* __s1, __owns_one_state<_CharT>* __s2,
-                          unsigned __mexp_begin, unsigned __mexp_end,
-                          bool __greedy = true,
-                          size_t __min = 0,
-                          size_t __max = numeric_limits<size_t>::max())
-        : base(__s1, __s2), __min_(__min), __max_(__max), __loop_id_(__loop_id),
-          __mexp_begin_(__mexp_begin), __mexp_end_(__mexp_end),
-          __greedy_(__greedy) {}
-
-    virtual void __exec(__state& __s) const;
-    virtual void __exec_split(bool __second, __state& __s) const;
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    void __init_repeat(__state& __s) const
-    {
-        __s.__loop_data_[__loop_id_].second = __s.__current_;
-        for (size_t __i = __mexp_begin_-1; __i != __mexp_end_-1; ++__i)
-        {
-            __s.__sub_matches_[__i].first = __s.__last_;
-            __s.__sub_matches_[__i].second = __s.__last_;
-            __s.__sub_matches_[__i].matched = false;
-        }
-    }
-};
-
-template <class _CharT>
-void
-__loop<_CharT>::__exec(__state& __s) const
-{
-    if (__s.__do_ == __state::__repeat)
-    {
-        bool __do_repeat = ++__s.__loop_data_[__loop_id_].first < __max_;
-        bool __do_alt = __s.__loop_data_[__loop_id_].first >= __min_;
-        if (__do_repeat && __do_alt &&
-                               __s.__loop_data_[__loop_id_].second == __s.__current_)
-            __do_repeat = false;
-        if (__do_repeat && __do_alt)
-            __s.__do_ = __state::__split;
-        else if (__do_repeat)
-        {
-            __s.__do_ = __state::__accept_but_not_consume;
-            __s.__node_ = this->first();
-            __init_repeat(__s);
-        }
-        else
-        {
-            __s.__do_ = __state::__accept_but_not_consume;
-            __s.__node_ = this->second();
-        }
-    }
-    else
-    {
-        __s.__loop_data_[__loop_id_].first = 0;
-        bool __do_repeat = 0 < __max_;
-        bool __do_alt = 0 >= __min_;
-        if (__do_repeat && __do_alt)
-            __s.__do_ = __state::__split;
-        else if (__do_repeat)
-        {
-            __s.__do_ = __state::__accept_but_not_consume;
-            __s.__node_ = this->first();
-            __init_repeat(__s);
-        }
-        else
-        {
-            __s.__do_ = __state::__accept_but_not_consume;
-            __s.__node_ = this->second();
-        }
-    }
-}
-
-template <class _CharT>
-void
-__loop<_CharT>::__exec_split(bool __second, __state& __s) const
-{
-    __s.__do_ = __state::__accept_but_not_consume;
-    if (__greedy_ != __second)
-    {
-        __s.__node_ = this->first();
-        __init_repeat(__s);
-    }
-    else
-        __s.__node_ = this->second();
-}
-
-// __alternate
-
-template <class _CharT>
-class __alternate
-    : public __owns_two_states<_CharT>
-{
-    typedef __owns_two_states<_CharT> base;
-
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __alternate(__owns_one_state<_CharT>* __s1,
-                         __owns_one_state<_CharT>* __s2)
-        : base(__s1, __s2) {}
-
-    virtual void __exec(__state& __s) const;
-    virtual void __exec_split(bool __second, __state& __s) const;
-};
-
-template <class _CharT>
-void
-__alternate<_CharT>::__exec(__state& __s) const
-{
-    __s.__do_ = __state::__split;
-}
-
-template <class _CharT>
-void
-__alternate<_CharT>::__exec_split(bool __second, __state& __s) const
-{
-    __s.__do_ = __state::__accept_but_not_consume;
-    if (__second)
-        __s.__node_ = this->second();
-    else
-        __s.__node_ = this->first();
-}
-
-// __begin_marked_subexpression
-
-template <class _CharT>
-class __begin_marked_subexpression
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    unsigned __mexp_;
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __begin_marked_subexpression(unsigned __mexp, __node<_CharT>* __s)
-        : base(__s), __mexp_(__mexp) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__begin_marked_subexpression<_CharT>::__exec(__state& __s) const
-{
-    __s.__do_ = __state::__accept_but_not_consume;
-    __s.__sub_matches_[__mexp_-1].first = __s.__current_;
-    __s.__node_ = this->first();
-}
-
-// __end_marked_subexpression
-
-template <class _CharT>
-class __end_marked_subexpression
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    unsigned __mexp_;
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __end_marked_subexpression(unsigned __mexp, __node<_CharT>* __s)
-        : base(__s), __mexp_(__mexp) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__end_marked_subexpression<_CharT>::__exec(__state& __s) const
-{
-    __s.__do_ = __state::__accept_but_not_consume;
-    __s.__sub_matches_[__mexp_-1].second = __s.__current_;
-    __s.__sub_matches_[__mexp_-1].matched = true;
-    __s.__node_ = this->first();
-}
-
-// __back_ref
-
-template <class _CharT>
-class __back_ref
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    unsigned __mexp_;
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __back_ref(unsigned __mexp, __node<_CharT>* __s)
-        : base(__s), __mexp_(__mexp) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__back_ref<_CharT>::__exec(__state& __s) const
-{
-    if (__mexp_ > __s.__sub_matches_.size())
-        __throw_regex_error<regex_constants::error_backref>();
-    sub_match<const _CharT*>& __sm = __s.__sub_matches_[__mexp_-1];
-    if (__sm.matched)
-    {
-        ptrdiff_t __len = __sm.second - __sm.first;
-        if (__s.__last_ - __s.__current_ >= __len &&
-            _VSTD::equal(__sm.first, __sm.second, __s.__current_))
-        {
-            __s.__do_ = __state::__accept_but_not_consume;
-            __s.__current_ += __len;
-            __s.__node_ = this->first();
-        }
-        else
-        {
-            __s.__do_ = __state::__reject;
-            __s.__node_ = nullptr;
-        }
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __back_ref_icase
-
-template <class _CharT, class _Traits>
-class __back_ref_icase
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    _Traits __traits_;
-    unsigned __mexp_;
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __back_ref_icase(const _Traits& __traits, unsigned __mexp,
-                              __node<_CharT>* __s)
-        : base(__s), __traits_(__traits), __mexp_(__mexp) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT, class _Traits>
-void
-__back_ref_icase<_CharT, _Traits>::__exec(__state& __s) const
-{
-    sub_match<const _CharT*>& __sm = __s.__sub_matches_[__mexp_-1];
-    if (__sm.matched)
-    {
-        ptrdiff_t __len = __sm.second - __sm.first;
-        if (__s.__last_ - __s.__current_ >= __len)
-        {
-            for (ptrdiff_t __i = 0; __i < __len; ++__i)
-            {
-                if (__traits_.translate_nocase(__sm.first[__i]) !=
-                                __traits_.translate_nocase(__s.__current_[__i]))
-                    goto __not_equal;
-            }
-            __s.__do_ = __state::__accept_but_not_consume;
-            __s.__current_ += __len;
-            __s.__node_ = this->first();
-        }
-        else
-        {
-            __s.__do_ = __state::__reject;
-            __s.__node_ = nullptr;
-        }
-    }
-    else
-    {
-__not_equal:
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __back_ref_collate
-
-template <class _CharT, class _Traits>
-class __back_ref_collate
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    _Traits __traits_;
-    unsigned __mexp_;
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __back_ref_collate(const _Traits& __traits, unsigned __mexp,
-                              __node<_CharT>* __s)
-        : base(__s), __traits_(__traits), __mexp_(__mexp) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT, class _Traits>
-void
-__back_ref_collate<_CharT, _Traits>::__exec(__state& __s) const
-{
-    sub_match<const _CharT*>& __sm = __s.__sub_matches_[__mexp_-1];
-    if (__sm.matched)
-    {
-        ptrdiff_t __len = __sm.second - __sm.first;
-        if (__s.__last_ - __s.__current_ >= __len)
-        {
-            for (ptrdiff_t __i = 0; __i < __len; ++__i)
-            {
-                if (__traits_.translate(__sm.first[__i]) !=
-                                       __traits_.translate(__s.__current_[__i]))
-                    goto __not_equal;
-            }
-            __s.__do_ = __state::__accept_but_not_consume;
-            __s.__current_ += __len;
-            __s.__node_ = this->first();
-        }
-        else
-        {
-            __s.__do_ = __state::__reject;
-            __s.__node_ = nullptr;
-        }
-    }
-    else
-    {
-__not_equal:
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __word_boundary
-
-template <class _CharT, class _Traits>
-class __word_boundary
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    _Traits __traits_;
-    bool __invert_;
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __word_boundary(const _Traits& __traits, bool __invert,
-                             __node<_CharT>* __s)
-        : base(__s), __traits_(__traits), __invert_(__invert) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT, class _Traits>
-void
-__word_boundary<_CharT, _Traits>::__exec(__state& __s) const
-{
-    bool __is_word_b = false;
-    if (__s.__first_ != __s.__last_)
-    {
-        if (__s.__current_ == __s.__last_)
-        {
-            if (!(__s.__flags_ & regex_constants::match_not_eow))
-            {
-                _CharT __c = __s.__current_[-1];
-                __is_word_b = __c == '_' ||
-                              __traits_.isctype(__c, ctype_base::alnum);
-            }
-        }
-        else if (__s.__current_ == __s.__first_ &&
-                !(__s.__flags_ & regex_constants::match_prev_avail))
-        {
-            if (!(__s.__flags_ & regex_constants::match_not_bow))
-            {
-                _CharT __c = *__s.__current_;
-                __is_word_b = __c == '_' ||
-                              __traits_.isctype(__c, ctype_base::alnum);
-            }
-        }
-        else
-        {
-            _CharT __c1 = __s.__current_[-1];
-            _CharT __c2 = *__s.__current_;
-            bool __is_c1_b = __c1 == '_' ||
-                             __traits_.isctype(__c1, ctype_base::alnum);
-            bool __is_c2_b = __c2 == '_' ||
-                             __traits_.isctype(__c2, ctype_base::alnum);
-            __is_word_b = __is_c1_b != __is_c2_b;
-        }
-    }
-    if (__is_word_b != __invert_)
-    {
-        __s.__do_ = __state::__accept_but_not_consume;
-        __s.__node_ = this->first();
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __l_anchor
-
-template <class _CharT>
-class __l_anchor
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __l_anchor(__node<_CharT>* __s)
-        : base(__s) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__l_anchor<_CharT>::__exec(__state& __s) const
-{
-    if (__s.__at_first_ && __s.__current_ == __s.__first_ &&
-        !(__s.__flags_ & regex_constants::match_not_bol))
-    {
-        __s.__do_ = __state::__accept_but_not_consume;
-        __s.__node_ = this->first();
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __r_anchor
-
-template <class _CharT>
-class __r_anchor
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __r_anchor(__node<_CharT>* __s)
-        : base(__s) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__r_anchor<_CharT>::__exec(__state& __s) const
-{
-    if (__s.__current_ == __s.__last_ &&
-        !(__s.__flags_ & regex_constants::match_not_eol))
-    {
-        __s.__do_ = __state::__accept_but_not_consume;
-        __s.__node_ = this->first();
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __match_any
-
-template <class _CharT>
-class __match_any
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __match_any(__node<_CharT>* __s)
-        : base(__s) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__match_any<_CharT>::__exec(__state& __s) const
-{
-    if (__s.__current_ != __s.__last_ && *__s.__current_ != 0)
-    {
-        __s.__do_ = __state::__accept_and_consume;
-        ++__s.__current_;
-        __s.__node_ = this->first();
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __match_any_but_newline
-
-template <class _CharT>
-class __match_any_but_newline
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __match_any_but_newline(__node<_CharT>* __s)
-        : base(__s) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <> _LIBCPP_FUNC_VIS void __match_any_but_newline<char>::__exec(__state&) const;
-template <> _LIBCPP_FUNC_VIS void __match_any_but_newline<wchar_t>::__exec(__state&) const;
-
-// __match_char
-
-template <class _CharT>
-class __match_char
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    _CharT __c_;
-
-    __match_char(const __match_char&);
-    __match_char& operator=(const __match_char&);
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __match_char(_CharT __c, __node<_CharT>* __s)
-        : base(__s), __c_(__c) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT>
-void
-__match_char<_CharT>::__exec(__state& __s) const
-{
-    if (__s.__current_ != __s.__last_ && *__s.__current_ == __c_)
-    {
-        __s.__do_ = __state::__accept_and_consume;
-        ++__s.__current_;
-        __s.__node_ = this->first();
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __match_char_icase
-
-template <class _CharT, class _Traits>
-class __match_char_icase
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    _Traits __traits_;
-    _CharT __c_;
-
-    __match_char_icase(const __match_char_icase&);
-    __match_char_icase& operator=(const __match_char_icase&);
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __match_char_icase(const _Traits& __traits, _CharT __c, __node<_CharT>* __s)
-        : base(__s), __traits_(__traits), __c_(__traits.translate_nocase(__c)) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT, class _Traits>
-void
-__match_char_icase<_CharT, _Traits>::__exec(__state& __s) const
-{
-    if (__s.__current_ != __s.__last_ &&
-        __traits_.translate_nocase(*__s.__current_) == __c_)
-    {
-        __s.__do_ = __state::__accept_and_consume;
-        ++__s.__current_;
-        __s.__node_ = this->first();
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __match_char_collate
-
-template <class _CharT, class _Traits>
-class __match_char_collate
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    _Traits __traits_;
-    _CharT __c_;
-
-    __match_char_collate(const __match_char_collate&);
-    __match_char_collate& operator=(const __match_char_collate&);
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __match_char_collate(const _Traits& __traits, _CharT __c, __node<_CharT>* __s)
-        : base(__s), __traits_(__traits), __c_(__traits.translate(__c)) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT, class _Traits>
-void
-__match_char_collate<_CharT, _Traits>::__exec(__state& __s) const
-{
-    if (__s.__current_ != __s.__last_ &&
-        __traits_.translate(*__s.__current_) == __c_)
-    {
-        __s.__do_ = __state::__accept_and_consume;
-        ++__s.__current_;
-        __s.__node_ = this->first();
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-// __bracket_expression
-
-template <class _CharT, class _Traits>
-class __bracket_expression
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-    typedef typename _Traits::string_type string_type;
-
-    _Traits __traits_;
-    vector<_CharT> __chars_;
-    vector<_CharT> __neg_chars_;
-    vector<pair<string_type, string_type> > __ranges_;
-    vector<pair<_CharT, _CharT> > __digraphs_;
-    vector<string_type> __equivalences_;
-    typename regex_traits<_CharT>::char_class_type __mask_;
-    typename regex_traits<_CharT>::char_class_type __neg_mask_;
-    bool __negate_;
-    bool __icase_;
-    bool __collate_;
-    bool __might_have_digraph_;
-
-    __bracket_expression(const __bracket_expression&);
-    __bracket_expression& operator=(const __bracket_expression&);
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __bracket_expression(const _Traits& __traits, __node<_CharT>* __s,
-                                 bool __negate, bool __icase, bool __collate)
-        : base(__s), __traits_(__traits), __mask_(), __neg_mask_(),
-          __negate_(__negate), __icase_(__icase), __collate_(__collate),
-          __might_have_digraph_(__traits_.getloc().name() != "C") {}
-
-    virtual void __exec(__state&) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool __negated() const {return __negate_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_char(_CharT __c)
-        {
-            if (__icase_)
-                __chars_.push_back(__traits_.translate_nocase(__c));
-            else if (__collate_)
-                __chars_.push_back(__traits_.translate(__c));
-            else
-                __chars_.push_back(__c);
-        }
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_neg_char(_CharT __c)
-        {
-            if (__icase_)
-                __neg_chars_.push_back(__traits_.translate_nocase(__c));
-            else if (__collate_)
-                __neg_chars_.push_back(__traits_.translate(__c));
-            else
-                __neg_chars_.push_back(__c);
-        }
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_range(string_type __b, string_type __e)
-        {
-            if (__collate_)
-            {
-                if (__icase_)
-                {
-                    for (size_t __i = 0; __i < __b.size(); ++__i)
-                        __b[__i] = __traits_.translate_nocase(__b[__i]);
-                    for (size_t __i = 0; __i < __e.size(); ++__i)
-                        __e[__i] = __traits_.translate_nocase(__e[__i]);
-                }
-                else
-                {
-                    for (size_t __i = 0; __i < __b.size(); ++__i)
-                        __b[__i] = __traits_.translate(__b[__i]);
-                    for (size_t __i = 0; __i < __e.size(); ++__i)
-                        __e[__i] = __traits_.translate(__e[__i]);
-                }
-                __ranges_.push_back(make_pair(
-                                  __traits_.transform(__b.begin(), __b.end()),
-                                  __traits_.transform(__e.begin(), __e.end())));
-            }
-            else
-            {
-                if (__b.size() != 1 || __e.size() != 1)
-                    __throw_regex_error<regex_constants::error_collate>();
-                if (__icase_)
-                {
-                    __b[0] = __traits_.translate_nocase(__b[0]);
-                    __e[0] = __traits_.translate_nocase(__e[0]);
-                }
-                __ranges_.push_back(make_pair(_VSTD::move(__b), _VSTD::move(__e)));
-            }
-        }
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_digraph(_CharT __c1, _CharT __c2)
-        {
-            if (__icase_)
-                __digraphs_.push_back(make_pair(__traits_.translate_nocase(__c1),
-                                                __traits_.translate_nocase(__c2)));
-            else if (__collate_)
-                __digraphs_.push_back(make_pair(__traits_.translate(__c1),
-                                                __traits_.translate(__c2)));
-            else
-                __digraphs_.push_back(make_pair(__c1, __c2));
-        }
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_equivalence(const string_type& __s)
-        {__equivalences_.push_back(__s);}
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_class(typename regex_traits<_CharT>::char_class_type __mask)
-        {__mask_ |= __mask;}
-    _LIBCPP_INLINE_VISIBILITY
-    void __add_neg_class(typename regex_traits<_CharT>::char_class_type __mask)
-        {__neg_mask_ |= __mask;}
-};
-
-template <class _CharT, class _Traits>
-void
-__bracket_expression<_CharT, _Traits>::__exec(__state& __s) const
-{
-    bool __found = false;
-    unsigned __consumed = 0;
-    if (__s.__current_ != __s.__last_)
-    {
-        ++__consumed;
-        if (__might_have_digraph_)
-        {
-            const _CharT* __next = _VSTD::next(__s.__current_);
-            if (__next != __s.__last_)
-            {
-                pair<_CharT, _CharT> __ch2(*__s.__current_, *__next);
-                if (__icase_)
-                {
-                    __ch2.first = __traits_.translate_nocase(__ch2.first);
-                    __ch2.second = __traits_.translate_nocase(__ch2.second);
-                }
-                else if (__collate_)
-                {
-                    __ch2.first = __traits_.translate(__ch2.first);
-                    __ch2.second = __traits_.translate(__ch2.second);
-                }
-                if (!__traits_.lookup_collatename(&__ch2.first, &__ch2.first+2).empty())
-                {
-                    // __ch2 is a digraph in this locale
-                    ++__consumed;
-                    for (size_t __i = 0; __i < __digraphs_.size(); ++__i)
-                    {
-                        if (__ch2 == __digraphs_[__i])
-                        {
-                            __found = true;
-                            goto __exit;
-                        }
-                    }
-                    if (__collate_ && !__ranges_.empty())
-                    {
-                        string_type __s2 = __traits_.transform(&__ch2.first,
-                                                               &__ch2.first + 2);
-                        for (size_t __i = 0; __i < __ranges_.size(); ++__i)
-                        {
-                            if (__ranges_[__i].first <= __s2 &&
-                                __s2 <= __ranges_[__i].second)
-                            {
-                                __found = true;
-                                goto __exit;
-                            }
-                        }
-                    }
-                    if (!__equivalences_.empty())
-                    {
-                        string_type __s2 = __traits_.transform_primary(&__ch2.first,
-                                                                       &__ch2.first + 2);
-                        for (size_t __i = 0; __i < __equivalences_.size(); ++__i)
-                        {
-                            if (__s2 == __equivalences_[__i])
-                            {
-                                __found = true;
-                                goto __exit;
-                            }
-                        }
-                    }
-                    if (__traits_.isctype(__ch2.first, __mask_) &&
-                        __traits_.isctype(__ch2.second, __mask_))
-                    {
-                        __found = true;
-                        goto __exit;
-                    }
-                    if (!__traits_.isctype(__ch2.first, __neg_mask_) &&
-                        !__traits_.isctype(__ch2.second, __neg_mask_))
-                    {
-                        __found = true;
-                        goto __exit;
-                    }
-                    goto __exit;
-                }
-            }
-        }
-        // test *__s.__current_ as not a digraph
-        _CharT __ch = *__s.__current_;
-        if (__icase_)
-            __ch = __traits_.translate_nocase(__ch);
-        else if (__collate_)
-            __ch = __traits_.translate(__ch);
-        for (size_t __i = 0; __i < __chars_.size(); ++__i)
-        {
-            if (__ch == __chars_[__i])
-            {
-                __found = true;
-                goto __exit;
-            }
-        }
-        // When there's at least one of __neg_chars_ and __neg_mask_, the set
-        // of "__found" chars is
-        //   union(complement(union(__neg_chars_, __neg_mask_)),
-        //         other cases...)
-        //
-        // It doesn't make sense to check this when there are no __neg_chars_
-        // and no __neg_mask_.
-        if (!(__neg_mask_ == 0 && __neg_chars_.empty()))
-        {
-            const bool __in_neg_mask = __traits_.isctype(__ch, __neg_mask_);
-          const bool __in_neg_chars =
-              std::find(__neg_chars_.begin(), __neg_chars_.end(), __ch) !=
-              __neg_chars_.end();
-          if (!(__in_neg_mask || __in_neg_chars))
-          {
-            __found = true;
-            goto __exit;
-          }
-        }
-        if (!__ranges_.empty())
-        {
-            string_type __s2 = __collate_ ?
-                                   __traits_.transform(&__ch, &__ch + 1) :
-                                   string_type(1, __ch);
-            for (size_t __i = 0; __i < __ranges_.size(); ++__i)
-            {
-                if (__ranges_[__i].first <= __s2 && __s2 <= __ranges_[__i].second)
-                {
-                    __found = true;
-                    goto __exit;
-                }
-            }
-        }
-        if (!__equivalences_.empty())
-        {
-            string_type __s2 = __traits_.transform_primary(&__ch, &__ch + 1);
-            for (size_t __i = 0; __i < __equivalences_.size(); ++__i)
-            {
-                if (__s2 == __equivalences_[__i])
-                {
-                    __found = true;
-                    goto __exit;
-                }
-            }
-        }
-        if (__traits_.isctype(__ch, __mask_))
-        {
-            __found = true;
-            goto __exit;
-        }
-    }
-    else
-        __found = __negate_;  // force reject
-__exit:
-    if (__found != __negate_)
-    {
-        __s.__do_ = __state::__accept_and_consume;
-        __s.__current_ += __consumed;
-        __s.__node_ = this->first();
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-template <class _CharT, class _Traits> class __lookahead;
-
-template <class _CharT, class _Traits = regex_traits<_CharT> >
-class _LIBCPP_TEMPLATE_VIS basic_regex
-{
-public:
-    // types:
-    typedef _CharT                              value_type;
-    typedef _Traits                             traits_type;
-    typedef typename _Traits::string_type       string_type;
-    typedef regex_constants::syntax_option_type flag_type;
-    typedef typename _Traits::locale_type       locale_type;
-
-private:
-    _Traits   __traits_;
-    flag_type __flags_;
-    unsigned __marked_count_;
-    unsigned __loop_count_;
-    int __open_count_;
-    shared_ptr<__empty_state<_CharT> > __start_;
-    __owns_one_state<_CharT>* __end_;
-
-    typedef _VSTD::__state<_CharT> __state;
-    typedef _VSTD::__node<_CharT> __node;
-
-public:
-    // constants:
-    static const regex_constants::syntax_option_type icase = regex_constants::icase;
-    static const regex_constants::syntax_option_type nosubs = regex_constants::nosubs;
-    static const regex_constants::syntax_option_type optimize = regex_constants::optimize;
-    static const regex_constants::syntax_option_type collate = regex_constants::collate;
-    static const regex_constants::syntax_option_type ECMAScript = regex_constants::ECMAScript;
-    static const regex_constants::syntax_option_type basic = regex_constants::basic;
-    static const regex_constants::syntax_option_type extended = regex_constants::extended;
-    static const regex_constants::syntax_option_type awk = regex_constants::awk;
-    static const regex_constants::syntax_option_type grep = regex_constants::grep;
-    static const regex_constants::syntax_option_type egrep = regex_constants::egrep;
-
-    // construct/copy/destroy:
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex()
-        : __flags_(), __marked_count_(0), __loop_count_(0), __open_count_(0),
-          __end_(0)
-        {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit basic_regex(const value_type* __p, flag_type __f = regex_constants::ECMAScript)
-        : __flags_(__f), __marked_count_(0), __loop_count_(0), __open_count_(0),
-          __end_(0)
-        {__parse(__p, __p + __traits_.length(__p));}
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex(const value_type* __p, size_t __len, flag_type __f = regex_constants::ECMAScript)
-        : __flags_(__f), __marked_count_(0), __loop_count_(0), __open_count_(0),
-          __end_(0)
-        {__parse(__p, __p + __len);}
-//     basic_regex(const basic_regex&) = default;
-//     basic_regex(basic_regex&&) = default;
-    template <class _ST, class _SA>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit basic_regex(const basic_string<value_type, _ST, _SA>& __p,
-                             flag_type __f = regex_constants::ECMAScript)
-        : __flags_(__f), __marked_count_(0), __loop_count_(0), __open_count_(0),
-          __end_(0)
-        {__parse(__p.begin(), __p.end());}
-    template <class _ForwardIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        basic_regex(_ForwardIterator __first, _ForwardIterator __last,
-                    flag_type __f = regex_constants::ECMAScript)
-        : __flags_(__f), __marked_count_(0), __loop_count_(0), __open_count_(0),
-          __end_(0)
-        {__parse(__first, __last);}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex(initializer_list<value_type> __il,
-                flag_type __f = regex_constants::ECMAScript)
-        : __flags_(__f), __marked_count_(0), __loop_count_(0), __open_count_(0),
-          __end_(0)
-        {__parse(__il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-//    ~basic_regex() = default;
-
-//     basic_regex& operator=(const basic_regex&) = default;
-//     basic_regex& operator=(basic_regex&&) = default;
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex& operator=(const value_type* __p)
-        {return assign(__p);}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex& operator=(initializer_list<value_type> __il)
-        {return assign(__il);}
-#endif  // _LIBCPP_CXX03_LANG
-    template <class _ST, class _SA>
-        _LIBCPP_INLINE_VISIBILITY
-        basic_regex& operator=(const basic_string<value_type, _ST, _SA>& __p)
-        {return assign(__p);}
-
-    // assign:
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex& assign(const basic_regex& __that)
-        {return *this = __that;}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex& assign(basic_regex&& __that) _NOEXCEPT
-        {return *this = _VSTD::move(__that);}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex& assign(const value_type* __p, flag_type __f = regex_constants::ECMAScript)
-        {return assign(__p, __p + __traits_.length(__p), __f);}
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex& assign(const value_type* __p, size_t __len, flag_type __f)
-        {return assign(__p, __p + __len, __f);}
-    template <class _ST, class _SA>
-        _LIBCPP_INLINE_VISIBILITY
-        basic_regex& assign(const basic_string<value_type, _ST, _SA>& __s,
-                            flag_type __f = regex_constants::ECMAScript)
-            {return assign(__s.begin(), __s.end(), __f);}
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-             __is_input_iterator  <_InputIterator>::value &&
-            !__is_forward_iterator<_InputIterator>::value,
-            basic_regex&
-        >::type
-        assign(_InputIterator __first, _InputIterator __last,
-                            flag_type __f = regex_constants::ECMAScript)
-        {
-            basic_string<_CharT> __t(__first, __last);
-            return assign(__t.begin(), __t.end(), __f);
-        }
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    void __member_init(flag_type __f)
-    {
-        __flags_ = __f;
-        __marked_count_ = 0;
-        __loop_count_ = 0;
-        __open_count_ = 0;
-        __end_ = nullptr;
-    }
-public:
-
-    template <class _ForwardIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value,
-            basic_regex&
-        >::type
-        assign(_ForwardIterator __first, _ForwardIterator __last,
-                            flag_type __f = regex_constants::ECMAScript)
-        {
-            return assign(basic_regex(__first, __last, __f));
-        }
-
-#ifndef _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_regex& assign(initializer_list<value_type> __il,
-                        flag_type __f = regex_constants::ECMAScript)
-        {return assign(__il.begin(), __il.end(), __f);}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-    // const operations:
-    _LIBCPP_INLINE_VISIBILITY
-    unsigned mark_count() const {return __marked_count_;}
-    _LIBCPP_INLINE_VISIBILITY
-    flag_type flags() const {return __flags_;}
-
-    // locale:
-    _LIBCPP_INLINE_VISIBILITY
-    locale_type imbue(locale_type __loc)
-    {
-        __member_init(ECMAScript);
-        __start_.reset();
-        return __traits_.imbue(__loc);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    locale_type getloc() const {return __traits_.getloc();}
-
-    // swap:
-    void swap(basic_regex& __r);
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    unsigned __loop_count() const {return __loop_count_;}
-
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_basic_reg_exp(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_RE_expression(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_simple_RE(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_nondupl_RE(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_one_char_or_coll_elem_RE(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_Back_open_paren(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_Back_close_paren(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_Back_open_brace(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_Back_close_brace(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_BACKREF(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_ORD_CHAR(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_QUOTED_CHAR(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_RE_dupl_symbol(_ForwardIterator __first, _ForwardIterator __last,
-                               __owns_one_state<_CharT>* __s,
-                               unsigned __mexp_begin, unsigned __mexp_end);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_ERE_dupl_symbol(_ForwardIterator __first, _ForwardIterator __last,
-                                __owns_one_state<_CharT>* __s,
-                                unsigned __mexp_begin, unsigned __mexp_end);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_bracket_expression(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_follow_list(_ForwardIterator __first, _ForwardIterator __last,
-                            __bracket_expression<_CharT, _Traits>* __ml);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_expression_term(_ForwardIterator __first, _ForwardIterator __last,
-                                __bracket_expression<_CharT, _Traits>* __ml);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_equivalence_class(_ForwardIterator __first, _ForwardIterator __last,
-                                  __bracket_expression<_CharT, _Traits>* __ml);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_character_class(_ForwardIterator __first, _ForwardIterator __last,
-                                __bracket_expression<_CharT, _Traits>* __ml);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_collating_symbol(_ForwardIterator __first, _ForwardIterator __last,
-                                 basic_string<_CharT>& __col_sym);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_DUP_COUNT(_ForwardIterator __first, _ForwardIterator __last, int& __c);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_extended_reg_exp(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_ERE_branch(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_ERE_expression(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_one_char_or_coll_elem_ERE(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_ORD_CHAR_ERE(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_QUOTED_CHAR_ERE(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_ecma_exp(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_alternative(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_term(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_assertion(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_atom(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_atom_escape(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_decimal_escape(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_character_class_escape(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_character_escape(_ForwardIterator __first, _ForwardIterator __last,
-                                 basic_string<_CharT>* __str = nullptr);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_pattern_character(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_grep(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_egrep(_ForwardIterator __first, _ForwardIterator __last);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_class_escape(_ForwardIterator __first, _ForwardIterator __last,
-                          basic_string<_CharT>& __str,
-                          __bracket_expression<_CharT, _Traits>* __ml);
-    template <class _ForwardIterator>
-        _ForwardIterator
-        __parse_awk_escape(_ForwardIterator __first, _ForwardIterator __last,
-                          basic_string<_CharT>* __str = nullptr);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __push_l_anchor();
-    void __push_r_anchor();
-    void __push_match_any();
-    void __push_match_any_but_newline();
-    _LIBCPP_INLINE_VISIBILITY
-    void __push_greedy_inf_repeat(size_t __min, __owns_one_state<_CharT>* __s,
-                                  unsigned __mexp_begin = 0, unsigned __mexp_end = 0)
-        {__push_loop(__min, numeric_limits<size_t>::max(), __s,
-                     __mexp_begin, __mexp_end);}
-    _LIBCPP_INLINE_VISIBILITY
-    void __push_nongreedy_inf_repeat(size_t __min, __owns_one_state<_CharT>* __s,
-                                  unsigned __mexp_begin = 0, unsigned __mexp_end = 0)
-        {__push_loop(__min, numeric_limits<size_t>::max(), __s,
-                     __mexp_begin, __mexp_end, false);}
-    void __push_loop(size_t __min, size_t __max, __owns_one_state<_CharT>* __s,
-                     size_t __mexp_begin = 0, size_t __mexp_end = 0,
-                     bool __greedy = true);
-    __bracket_expression<_CharT, _Traits>* __start_matching_list(bool __negate);
-    void __push_char(value_type __c);
-    void __push_back_ref(int __i);
-    void __push_alternation(__owns_one_state<_CharT>* __sa,
-                            __owns_one_state<_CharT>* __sb);
-    void __push_begin_marked_subexpression();
-    void __push_end_marked_subexpression(unsigned);
-    void __push_empty();
-    void __push_word_boundary(bool);
-    void __push_lookahead(const basic_regex&, bool, unsigned);
-
-    template <class _Allocator>
-        bool
-        __search(const _CharT* __first, const _CharT* __last,
-                 match_results<const _CharT*, _Allocator>& __m,
-                 regex_constants::match_flag_type __flags) const;
-
-    template <class _Allocator>
-        bool
-        __match_at_start(const _CharT* __first, const _CharT* __last,
-                 match_results<const _CharT*, _Allocator>& __m,
-                 regex_constants::match_flag_type __flags, bool) const;
-    template <class _Allocator>
-        bool
-        __match_at_start_ecma(const _CharT* __first, const _CharT* __last,
-                 match_results<const _CharT*, _Allocator>& __m,
-                 regex_constants::match_flag_type __flags, bool) const;
-    template <class _Allocator>
-        bool
-        __match_at_start_posix_nosubs(const _CharT* __first, const _CharT* __last,
-                 match_results<const _CharT*, _Allocator>& __m,
-                 regex_constants::match_flag_type __flags, bool) const;
-    template <class _Allocator>
-        bool
-        __match_at_start_posix_subs(const _CharT* __first, const _CharT* __last,
-                 match_results<const _CharT*, _Allocator>& __m,
-                 regex_constants::match_flag_type __flags, bool) const;
-
-    template <class _Bp, class _Ap, class _Cp, class _Tp>
-    friend
-    bool
-    regex_search(_Bp, _Bp, match_results<_Bp, _Ap>&, const basic_regex<_Cp, _Tp>&,
-                 regex_constants::match_flag_type);
-
-    template <class _Ap, class _Cp, class _Tp>
-    friend
-    bool
-    regex_search(const _Cp*, const _Cp*, match_results<const _Cp*, _Ap>&,
-                 const basic_regex<_Cp, _Tp>&, regex_constants::match_flag_type);
-
-    template <class _Bp, class _Cp, class _Tp>
-    friend
-    bool
-    regex_search(_Bp, _Bp, const basic_regex<_Cp, _Tp>&,
-                 regex_constants::match_flag_type);
-
-    template <class _Cp, class _Tp>
-    friend
-    bool
-    regex_search(const _Cp*, const _Cp*,
-                 const basic_regex<_Cp, _Tp>&, regex_constants::match_flag_type);
-
-    template <class _Cp, class _Ap, class _Tp>
-    friend
-    bool
-    regex_search(const _Cp*, match_results<const _Cp*, _Ap>&, const basic_regex<_Cp, _Tp>&,
-                 regex_constants::match_flag_type);
-
-    template <class _ST, class _SA, class _Cp, class _Tp>
-    friend
-    bool
-    regex_search(const basic_string<_Cp, _ST, _SA>& __s,
-                 const basic_regex<_Cp, _Tp>& __e,
-                 regex_constants::match_flag_type __flags);
-
-    template <class _ST, class _SA, class _Ap, class _Cp, class _Tp>
-    friend
-    bool
-    regex_search(const basic_string<_Cp, _ST, _SA>& __s,
-                 match_results<typename basic_string<_Cp, _ST, _SA>::const_iterator, _Ap>&,
-                 const basic_regex<_Cp, _Tp>& __e,
-                 regex_constants::match_flag_type __flags);
-
-    template <class _Iter, class _Ap, class _Cp, class _Tp>
-    friend
-    bool
-    regex_search(__wrap_iter<_Iter> __first,
-                 __wrap_iter<_Iter> __last,
-                 match_results<__wrap_iter<_Iter>, _Ap>& __m,
-                 const basic_regex<_Cp, _Tp>& __e,
-                 regex_constants::match_flag_type __flags);
-
-    template <class, class> friend class __lookahead;
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template <class _ForwardIterator,
-          class = typename enable_if<__is_forward_iterator<_ForwardIterator>::value, nullptr_t>::type
->
-basic_regex(_ForwardIterator, _ForwardIterator,
-            regex_constants::syntax_option_type = regex_constants::ECMAScript)
-    -> basic_regex<typename iterator_traits<_ForwardIterator>::value_type>;
-#endif
-
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::icase;
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::nosubs;
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::optimize;
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::collate;
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::ECMAScript;
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::basic;
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::extended;
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::awk;
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::grep;
-template <class _CharT, class _Traits>
-    const regex_constants::syntax_option_type basic_regex<_CharT, _Traits>::egrep;
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::swap(basic_regex& __r)
-{
-    using _VSTD::swap;
-    swap(__traits_, __r.__traits_);
-    swap(__flags_, __r.__flags_);
-    swap(__marked_count_, __r.__marked_count_);
-    swap(__loop_count_, __r.__loop_count_);
-    swap(__open_count_, __r.__open_count_);
-    swap(__start_, __r.__start_);
-    swap(__end_, __r.__end_);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_regex<_CharT, _Traits>& __x, basic_regex<_CharT, _Traits>& __y)
-{
-    return __x.swap(__y);
-}
-
-// __lookahead
-
-template <class _CharT, class _Traits>
-class __lookahead
-    : public __owns_one_state<_CharT>
-{
-    typedef __owns_one_state<_CharT> base;
-
-    basic_regex<_CharT, _Traits> __exp_;
-    unsigned __mexp_;
-    bool __invert_;
-
-    __lookahead(const __lookahead&);
-    __lookahead& operator=(const __lookahead&);
-public:
-    typedef _VSTD::__state<_CharT> __state;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __lookahead(const basic_regex<_CharT, _Traits>& __exp, bool __invert, __node<_CharT>* __s, unsigned __mexp)
-        : base(__s), __exp_(__exp), __mexp_(__mexp), __invert_(__invert) {}
-
-    virtual void __exec(__state&) const;
-};
-
-template <class _CharT, class _Traits>
-void
-__lookahead<_CharT, _Traits>::__exec(__state& __s) const
-{
-    match_results<const _CharT*> __m;
-    __m.__init(1 + __exp_.mark_count(), __s.__current_, __s.__last_);
-    bool __matched = __exp_.__match_at_start_ecma(
-        __s.__current_, __s.__last_,
-        __m,
-        (__s.__flags_ | regex_constants::match_continuous) &
-        ~regex_constants::__full_match,
-        __s.__at_first_ && __s.__current_ == __s.__first_);
-    if (__matched != __invert_)
-    {
-        __s.__do_ = __state::__accept_but_not_consume;
-        __s.__node_ = this->first();
-        for (unsigned __i = 1; __i < __m.size(); ++__i) {
-            __s.__sub_matches_[__mexp_ + __i - 1] = __m.__matches_[__i];
-        }
-    }
-    else
-    {
-        __s.__do_ = __state::__reject;
-        __s.__node_ = nullptr;
-    }
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse(_ForwardIterator __first,
-                                      _ForwardIterator __last)
-{
-    {
-        unique_ptr<__node> __h(new __end_state<_CharT>);
-        __start_.reset(new __empty_state<_CharT>(__h.get()));
-        __h.release();
-        __end_ = __start_.get();
-    }
-    switch (__flags_ & 0x1F0)
-    {
-    case ECMAScript:
-        __first = __parse_ecma_exp(__first, __last);
-        break;
-    case basic:
-        __first = __parse_basic_reg_exp(__first, __last);
-        break;
-    case extended:
-    case awk:
-        __first = __parse_extended_reg_exp(__first, __last);
-        break;
-    case grep:
-        __first = __parse_grep(__first, __last);
-        break;
-    case egrep:
-        __first = __parse_egrep(__first, __last);
-        break;
-    default:
-        __throw_regex_error<regex_constants::__re_err_grammar>();
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_basic_reg_exp(_ForwardIterator __first,
-                                                    _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        if (*__first == '^')
-        {
-            __push_l_anchor();
-            ++__first;
-        }
-        if (__first != __last)
-        {
-            __first = __parse_RE_expression(__first, __last);
-            if (__first != __last)
-            {
-                _ForwardIterator __temp = _VSTD::next(__first);
-                if (__temp == __last && *__first == '$')
-                {
-                    __push_r_anchor();
-                    ++__first;
-                }
-            }
-        }
-        if (__first != __last)
-            __throw_regex_error<regex_constants::__re_err_empty>();
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_extended_reg_exp(_ForwardIterator __first,
-                                                       _ForwardIterator __last)
-{
-    __owns_one_state<_CharT>* __sa = __end_;
-    _ForwardIterator __temp = __parse_ERE_branch(__first, __last);
-    if (__temp == __first)
-        __throw_regex_error<regex_constants::__re_err_empty>();
-    __first = __temp;
-    while (__first != __last && *__first == '|')
-    {
-        __owns_one_state<_CharT>* __sb = __end_;
-        __temp = __parse_ERE_branch(++__first, __last);
-        if (__temp == __first)
-            __throw_regex_error<regex_constants::__re_err_empty>();
-        __push_alternation(__sa, __sb);
-        __first = __temp;
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_ERE_branch(_ForwardIterator __first,
-                                                 _ForwardIterator __last)
-{
-    _ForwardIterator __temp = __parse_ERE_expression(__first, __last);
-    if (__temp == __first)
-        __throw_regex_error<regex_constants::__re_err_empty>();
-    do
-    {
-        __first = __temp;
-        __temp = __parse_ERE_expression(__first, __last);
-    } while (__temp != __first);
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_ERE_expression(_ForwardIterator __first,
-                                                     _ForwardIterator __last)
-{
-    __owns_one_state<_CharT>* __e = __end_;
-    unsigned __mexp_begin = __marked_count_;
-    _ForwardIterator __temp = __parse_one_char_or_coll_elem_ERE(__first, __last);
-    if (__temp == __first && __temp != __last)
-    {
-        switch (*__temp)
-        {
-        case '^':
-            __push_l_anchor();
-            ++__temp;
-            break;
-        case '$':
-            __push_r_anchor();
-            ++__temp;
-            break;
-        case '(':
-            __push_begin_marked_subexpression();
-            unsigned __temp_count = __marked_count_;
-            ++__open_count_;
-            __temp = __parse_extended_reg_exp(++__temp, __last);
-            if (__temp == __last || *__temp != ')')
-                __throw_regex_error<regex_constants::error_paren>();
-            __push_end_marked_subexpression(__temp_count);
-            --__open_count_;
-            ++__temp;
-            break;
-        }
-    }
-    if (__temp != __first)
-        __temp = __parse_ERE_dupl_symbol(__temp, __last, __e, __mexp_begin+1,
-                                         __marked_count_+1);
-    __first = __temp;
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_RE_expression(_ForwardIterator __first,
-                                                    _ForwardIterator __last)
-{
-    while (true)
-    {
-        _ForwardIterator __temp = __parse_simple_RE(__first, __last);
-        if (__temp == __first)
-            break;
-        __first = __temp;
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_simple_RE(_ForwardIterator __first,
-                                                _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        __owns_one_state<_CharT>* __e = __end_;
-        unsigned __mexp_begin = __marked_count_;
-        _ForwardIterator __temp = __parse_nondupl_RE(__first, __last);
-        if (__temp != __first)
-            __first = __parse_RE_dupl_symbol(__temp, __last, __e,
-                                             __mexp_begin+1, __marked_count_+1);
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_nondupl_RE(_ForwardIterator __first,
-                                                 _ForwardIterator __last)
-{
-    _ForwardIterator __temp = __first;
-    __first = __parse_one_char_or_coll_elem_RE(__first, __last);
-    if (__temp == __first)
-    {
-        __temp = __parse_Back_open_paren(__first, __last);
-        if (__temp != __first)
-        {
-            __push_begin_marked_subexpression();
-            unsigned __temp_count = __marked_count_;
-            __first = __parse_RE_expression(__temp, __last);
-            __temp = __parse_Back_close_paren(__first, __last);
-            if (__temp == __first)
-                __throw_regex_error<regex_constants::error_paren>();
-            __push_end_marked_subexpression(__temp_count);
-            __first = __temp;
-        }
-        else
-            __first = __parse_BACKREF(__first, __last);
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_one_char_or_coll_elem_RE(
-                                                       _ForwardIterator __first,
-                                                       _ForwardIterator __last)
-{
-    _ForwardIterator __temp = __parse_ORD_CHAR(__first, __last);
-    if (__temp == __first)
-    {
-        __temp = __parse_QUOTED_CHAR(__first, __last);
-        if (__temp == __first)
-        {
-            if (__temp != __last && *__temp == '.')
-            {
-                __push_match_any();
-                ++__temp;
-            }
-            else
-                __temp = __parse_bracket_expression(__first, __last);
-        }
-    }
-    __first = __temp;
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_one_char_or_coll_elem_ERE(
-                                                       _ForwardIterator __first,
-                                                       _ForwardIterator __last)
-{
-    _ForwardIterator __temp = __parse_ORD_CHAR_ERE(__first, __last);
-    if (__temp == __first)
-    {
-        __temp = __parse_QUOTED_CHAR_ERE(__first, __last);
-        if (__temp == __first)
-        {
-            if (__temp != __last && *__temp == '.')
-            {
-                __push_match_any();
-                ++__temp;
-            }
-            else
-                __temp = __parse_bracket_expression(__first, __last);
-        }
-    }
-    __first = __temp;
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_Back_open_paren(_ForwardIterator __first,
-                                                      _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __temp = _VSTD::next(__first);
-        if (__temp != __last)
-        {
-            if (*__first == '\\' && *__temp == '(')
-                __first = ++__temp;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_Back_close_paren(_ForwardIterator __first,
-                                                       _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __temp = _VSTD::next(__first);
-        if (__temp != __last)
-        {
-            if (*__first == '\\' && *__temp == ')')
-                __first = ++__temp;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_Back_open_brace(_ForwardIterator __first,
-                                                      _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __temp = _VSTD::next(__first);
-        if (__temp != __last)
-        {
-            if (*__first == '\\' && *__temp == '{')
-                __first = ++__temp;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_Back_close_brace(_ForwardIterator __first,
-                                                       _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __temp = _VSTD::next(__first);
-        if (__temp != __last)
-        {
-            if (*__first == '\\' && *__temp == '}')
-                __first = ++__temp;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_BACKREF(_ForwardIterator __first,
-                                              _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __temp = _VSTD::next(__first);
-        if (__temp != __last)
-        {
-            if (*__first == '\\')
-            { 
-                int __val = __traits_.value(*__temp, 10);
-                if (__val >= 1 && __val <= 9)
-                {
-                    __push_back_ref(__val);
-                    __first = ++__temp;
-                }
-            }
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_ORD_CHAR(_ForwardIterator __first,
-                                               _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __temp = _VSTD::next(__first);
-        if (__temp == __last && *__first == '$')
-            return __first;
-        // Not called inside a bracket
-        if (*__first == '.' || *__first == '\\' || *__first == '[')
-            return __first;
-        __push_char(*__first);
-        ++__first;
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_ORD_CHAR_ERE(_ForwardIterator __first,
-                                                   _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        switch (*__first)
-        {
-        case '^':
-        case '.':
-        case '[':
-        case '$':
-        case '(':
-        case '|':
-        case '*':
-        case '+':
-        case '?':
-        case '{':
-        case '\\':
-            break;
-        case ')':
-            if (__open_count_ == 0)
-            {
-                __push_char(*__first);
-                ++__first;
-            }
-            break;
-        default:
-            __push_char(*__first);
-            ++__first;
-            break;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_QUOTED_CHAR(_ForwardIterator __first,
-                                                  _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __temp = _VSTD::next(__first);
-        if (__temp != __last)
-        {
-            if (*__first == '\\')
-            {
-                switch (*__temp)
-                {
-                case '^':
-                case '.':
-                case '*':
-                case '[':
-                case '$':
-                case '\\':
-                    __push_char(*__temp);
-                    __first = ++__temp;
-                    break;
-                }
-            }
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_QUOTED_CHAR_ERE(_ForwardIterator __first,
-                                                      _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __temp = _VSTD::next(__first);
-        if (__temp != __last)
-        {
-            if (*__first == '\\')
-            {
-                switch (*__temp)
-                {
-                case '^':
-                case '.':
-                case '*':
-                case '[':
-                case '$':
-                case '\\':
-                case '(':
-                case ')':
-                case '|':
-                case '+':
-                case '?':
-                case '{':
-                case '}':
-                    __push_char(*__temp);
-                    __first = ++__temp;
-                    break;
-                default:
-                    if ((__flags_ & 0x1F0) == awk)
-                        __first = __parse_awk_escape(++__first, __last);
-                    break;
-                }
-            }
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_RE_dupl_symbol(_ForwardIterator __first,
-                                                     _ForwardIterator __last,
-                                                     __owns_one_state<_CharT>* __s,
-                                                     unsigned __mexp_begin,
-                                                     unsigned __mexp_end)
-{
-    if (__first != __last)
-    {
-        if (*__first == '*')
-        {
-            __push_greedy_inf_repeat(0, __s, __mexp_begin, __mexp_end);
-            ++__first;
-        }
-        else
-        {
-            _ForwardIterator __temp = __parse_Back_open_brace(__first, __last);
-            if (__temp != __first)
-            {
-                int __min = 0;
-                __first = __temp;
-                __temp = __parse_DUP_COUNT(__first, __last, __min);
-                if (__temp == __first)
-                    __throw_regex_error<regex_constants::error_badbrace>();
-                __first = __temp;
-                if (__first == __last)
-                    __throw_regex_error<regex_constants::error_brace>();
-                if (*__first != ',')
-                {
-                    __temp = __parse_Back_close_brace(__first, __last);
-                    if (__temp == __first)
-                        __throw_regex_error<regex_constants::error_brace>();
-                    __push_loop(__min, __min, __s, __mexp_begin, __mexp_end,
-                                    true);
-                    __first = __temp;
-                }
-                else
-                {
-                    ++__first;  // consume ','
-                    int __max = -1;
-                    __first = __parse_DUP_COUNT(__first, __last, __max);
-                    __temp = __parse_Back_close_brace(__first, __last);
-                    if (__temp == __first)
-                        __throw_regex_error<regex_constants::error_brace>();
-                    if (__max == -1)
-                        __push_greedy_inf_repeat(__min, __s, __mexp_begin, __mexp_end);
-                    else
-                    {
-                        if (__max < __min)
-                            __throw_regex_error<regex_constants::error_badbrace>();
-                        __push_loop(__min, __max, __s, __mexp_begin, __mexp_end,
-                                    true);
-                    }
-                    __first = __temp;
-                }
-            }
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_ERE_dupl_symbol(_ForwardIterator __first,
-                                                      _ForwardIterator __last,
-                                                      __owns_one_state<_CharT>* __s,
-                                                      unsigned __mexp_begin,
-                                                      unsigned __mexp_end)
-{
-    if (__first != __last)
-    {
-        unsigned __grammar = __flags_ & 0x1F0;
-        switch (*__first)
-        {
-        case '*':
-            ++__first;
-            if (__grammar == ECMAScript && __first != __last && *__first == '?')
-            {
-                ++__first;
-                __push_nongreedy_inf_repeat(0, __s, __mexp_begin, __mexp_end);
-            }
-            else
-                __push_greedy_inf_repeat(0, __s, __mexp_begin, __mexp_end);
-            break;
-        case '+':
-            ++__first;
-            if (__grammar == ECMAScript && __first != __last && *__first == '?')
-            {
-                ++__first;
-                __push_nongreedy_inf_repeat(1, __s, __mexp_begin, __mexp_end);
-            }
-            else
-                __push_greedy_inf_repeat(1, __s, __mexp_begin, __mexp_end);
-            break;
-        case '?':
-            ++__first;
-            if (__grammar == ECMAScript && __first != __last && *__first == '?')
-            {
-                ++__first;
-                __push_loop(0, 1, __s, __mexp_begin, __mexp_end, false);
-            }
-            else
-                __push_loop(0, 1, __s, __mexp_begin, __mexp_end);
-            break;
-        case '{':
-            {
-                int __min;
-                _ForwardIterator __temp = __parse_DUP_COUNT(++__first, __last, __min);
-                if (__temp == __first)
-                    __throw_regex_error<regex_constants::error_badbrace>();
-                __first = __temp;
-                if (__first == __last)
-                    __throw_regex_error<regex_constants::error_brace>();
-                switch (*__first)
-                {
-                case '}':
-                    ++__first;
-                    if (__grammar == ECMAScript && __first != __last && *__first == '?')
-                    {
-                        ++__first;
-                        __push_loop(__min, __min, __s, __mexp_begin, __mexp_end, false);
-                    }
-                    else
-                        __push_loop(__min, __min, __s, __mexp_begin, __mexp_end);
-                    break;
-                case ',':
-                    ++__first;
-                    if (__first == __last)
-                        __throw_regex_error<regex_constants::error_badbrace>();
-                    if (*__first == '}')
-                    {
-                        ++__first;
-                        if (__grammar == ECMAScript && __first != __last && *__first == '?')
-                        {
-                            ++__first;
-                            __push_nongreedy_inf_repeat(__min, __s, __mexp_begin, __mexp_end);
-                        }
-                        else
-                            __push_greedy_inf_repeat(__min, __s, __mexp_begin, __mexp_end);
-                    }
-                    else
-                    {
-                        int __max = -1;
-                        __temp = __parse_DUP_COUNT(__first, __last, __max);
-                        if (__temp == __first)
-                            __throw_regex_error<regex_constants::error_brace>();
-                        __first = __temp;
-                        if (__first == __last || *__first != '}')
-                            __throw_regex_error<regex_constants::error_brace>();
-                        ++__first;
-                        if (__max < __min)
-                            __throw_regex_error<regex_constants::error_badbrace>();
-                        if (__grammar == ECMAScript && __first != __last && *__first == '?')
-                        {
-                            ++__first;
-                            __push_loop(__min, __max, __s, __mexp_begin, __mexp_end, false);
-                        }
-                        else
-                            __push_loop(__min, __max, __s, __mexp_begin, __mexp_end);
-                    }
-                    break;
-                default:
-                    __throw_regex_error<regex_constants::error_badbrace>();
-                }
-            }
-            break;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_bracket_expression(_ForwardIterator __first,
-                                                         _ForwardIterator __last)
-{
-    if (__first != __last && *__first == '[')
-    {
-        ++__first;
-        if (__first == __last)
-            __throw_regex_error<regex_constants::error_brack>();
-        bool __negate = false;
-        if (*__first == '^')
-        {
-            ++__first;
-            __negate = true;
-        }
-        __bracket_expression<_CharT, _Traits>* __ml = __start_matching_list(__negate);
-        // __ml owned by *this
-        if (__first == __last)
-            __throw_regex_error<regex_constants::error_brack>();
-        if ((__flags_ & 0x1F0) != ECMAScript && *__first == ']')
-        {
-            __ml->__add_char(']');
-            ++__first;
-        }
-        __first = __parse_follow_list(__first, __last, __ml);
-        if (__first == __last)
-            __throw_regex_error<regex_constants::error_brack>();
-        if (*__first == '-')
-        {
-            __ml->__add_char('-');
-            ++__first;
-        }
-        if (__first == __last || *__first != ']')
-            __throw_regex_error<regex_constants::error_brack>();
-        ++__first;
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_follow_list(_ForwardIterator __first,
-                                    _ForwardIterator __last,
-                                    __bracket_expression<_CharT, _Traits>* __ml)
-{
-    if (__first != __last)
-    {
-        while (true)
-        {
-            _ForwardIterator __temp = __parse_expression_term(__first, __last,
-                                                              __ml);
-            if (__temp == __first)
-                break;
-            __first = __temp;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_expression_term(_ForwardIterator __first,
-                                    _ForwardIterator __last,
-                                    __bracket_expression<_CharT, _Traits>* __ml)
-{
-    if (__first != __last && *__first != ']')
-    {
-        _ForwardIterator __temp = _VSTD::next(__first);
-        basic_string<_CharT> __start_range;
-        if (__temp != __last && *__first == '[')
-        {
-            if (*__temp == '=')
-                return __parse_equivalence_class(++__temp, __last, __ml);
-            else if (*__temp == ':')
-                return __parse_character_class(++__temp, __last, __ml);
-            else if (*__temp == '.')
-                __first = __parse_collating_symbol(++__temp, __last, __start_range);
-        }
-        unsigned __grammar = __flags_ & 0x1F0;
-        if (__start_range.empty())
-        {
-            if ((__grammar == ECMAScript || __grammar == awk) && *__first == '\\')
-            {
-                if (__grammar == ECMAScript)
-                    __first = __parse_class_escape(++__first, __last, __start_range, __ml);
-                else
-                    __first = __parse_awk_escape(++__first, __last, &__start_range);
-            }
-            else
-            {
-                __start_range = *__first;
-                ++__first;
-            }
-        }
-        if (__first != __last && *__first != ']')
-        {
-            __temp = _VSTD::next(__first);
-            if (__temp != __last && *__first == '-' && *__temp != ']')
-            {
-                // parse a range
-                basic_string<_CharT> __end_range;
-                __first = __temp;
-                ++__temp;
-                if (__temp != __last && *__first == '[' && *__temp == '.')
-                    __first = __parse_collating_symbol(++__temp, __last, __end_range);
-                else
-                {
-                    if ((__grammar == ECMAScript || __grammar == awk) && *__first == '\\')
-                    {
-                        if (__grammar == ECMAScript)
-                            __first = __parse_class_escape(++__first, __last,
-                                                           __end_range, __ml);
-                        else
-                            __first = __parse_awk_escape(++__first, __last,
-                                                         &__end_range);
-                    }
-                    else
-                    {
-                        __end_range = *__first;
-                        ++__first;
-                    }
-                }
-                __ml->__add_range(_VSTD::move(__start_range), _VSTD::move(__end_range));
-            }
-            else if (!__start_range.empty())
-            {
-                if (__start_range.size() == 1)
-                    __ml->__add_char(__start_range[0]);
-                else
-                    __ml->__add_digraph(__start_range[0], __start_range[1]);
-            }
-        }
-        else if (!__start_range.empty())
-        {
-            if (__start_range.size() == 1)
-                __ml->__add_char(__start_range[0]);
-            else
-                __ml->__add_digraph(__start_range[0], __start_range[1]);
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_class_escape(_ForwardIterator __first,
-                          _ForwardIterator __last,
-                          basic_string<_CharT>& __str,
-                          __bracket_expression<_CharT, _Traits>* __ml)
-{
-    if (__first == __last)
-        __throw_regex_error<regex_constants::error_escape>();
-    switch (*__first)
-    {
-    case 0:
-        __str = *__first;
-        return ++__first;
-    case 'b':
-        __str = _CharT(8);
-        return ++__first;
-    case 'd':
-        __ml->__add_class(ctype_base::digit);
-        return ++__first;
-    case 'D':
-        __ml->__add_neg_class(ctype_base::digit);
-        return ++__first;
-    case 's':
-        __ml->__add_class(ctype_base::space);
-        return ++__first;
-    case 'S':
-        __ml->__add_neg_class(ctype_base::space);
-        return ++__first;
-    case 'w':
-        __ml->__add_class(ctype_base::alnum);
-        __ml->__add_char('_');
-        return ++__first;
-    case 'W':
-        __ml->__add_neg_class(ctype_base::alnum);
-        __ml->__add_neg_char('_');
-        return ++__first;
-    }
-    __first = __parse_character_escape(__first, __last, &__str);
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_awk_escape(_ForwardIterator __first,
-                          _ForwardIterator __last,
-                          basic_string<_CharT>* __str)
-{
-    if (__first == __last)
-        __throw_regex_error<regex_constants::error_escape>();
-    switch (*__first)
-    {
-    case '\\':
-    case '"':
-    case '/':
-        if (__str)
-            *__str = *__first;
-        else
-            __push_char(*__first);
-        return ++__first;
-    case 'a':
-        if (__str)
-            *__str = _CharT(7);
-        else
-            __push_char(_CharT(7));
-        return ++__first;
-    case 'b':
-        if (__str)
-            *__str = _CharT(8);
-        else
-            __push_char(_CharT(8));
-        return ++__first;
-    case 'f':
-        if (__str)
-            *__str = _CharT(0xC);
-        else
-            __push_char(_CharT(0xC));
-        return ++__first;
-    case 'n':
-        if (__str)
-            *__str = _CharT(0xA);
-        else
-            __push_char(_CharT(0xA));
-        return ++__first;
-    case 'r':
-        if (__str)
-            *__str = _CharT(0xD);
-        else
-            __push_char(_CharT(0xD));
-        return ++__first;
-    case 't':
-        if (__str)
-            *__str = _CharT(0x9);
-        else
-            __push_char(_CharT(0x9));
-        return ++__first;
-    case 'v':
-        if (__str)
-            *__str = _CharT(0xB);
-        else
-            __push_char(_CharT(0xB));
-        return ++__first;
-    }
-    if ('0' <= *__first && *__first <= '7')
-    {
-        unsigned __val = *__first - '0';
-        if (++__first != __last && ('0' <= *__first && *__first <= '7'))
-        {
-            __val = 8 * __val + *__first - '0';
-            if (++__first != __last && ('0' <= *__first && *__first <= '7'))
-                __val = 8 * __val + *__first++ - '0';
-        }
-        if (__str)
-            *__str = _CharT(__val);
-        else
-            __push_char(_CharT(__val));
-    }
-    else
-        __throw_regex_error<regex_constants::error_escape>();
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_equivalence_class(_ForwardIterator __first,
-                                    _ForwardIterator __last,
-                                    __bracket_expression<_CharT, _Traits>* __ml)
-{
-    // Found [=
-    //   This means =] must exist
-    value_type _Equal_close[2] = {'=', ']'};
-    _ForwardIterator __temp = _VSTD::search(__first, __last, _Equal_close,
-                                                            _Equal_close+2);
-    if (__temp == __last)
-        __throw_regex_error<regex_constants::error_brack>();
-    // [__first, __temp) contains all text in [= ... =]
-    string_type __collate_name =
-        __traits_.lookup_collatename(__first, __temp);
-    if (__collate_name.empty())
-        __throw_regex_error<regex_constants::error_collate>();
-    string_type __equiv_name =
-        __traits_.transform_primary(__collate_name.begin(),
-                                    __collate_name.end());
-    if (!__equiv_name.empty())
-        __ml->__add_equivalence(__equiv_name);
-    else
-    {
-        switch (__collate_name.size())
-        {
-        case 1:
-            __ml->__add_char(__collate_name[0]);
-            break;
-        case 2:
-            __ml->__add_digraph(__collate_name[0], __collate_name[1]);
-            break;
-        default:
-            __throw_regex_error<regex_constants::error_collate>();
-        }
-    }
-    __first = _VSTD::next(__temp, 2);
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_character_class(_ForwardIterator __first,
-                                    _ForwardIterator __last,
-                                    __bracket_expression<_CharT, _Traits>* __ml)
-{
-    // Found [:
-    //   This means :] must exist
-    value_type _Colon_close[2] = {':', ']'};
-    _ForwardIterator __temp = _VSTD::search(__first, __last, _Colon_close,
-                                                            _Colon_close+2);
-    if (__temp == __last)
-        __throw_regex_error<regex_constants::error_brack>();
-    // [__first, __temp) contains all text in [: ... :]
-    typedef typename _Traits::char_class_type char_class_type;
-    char_class_type __class_type =
-        __traits_.lookup_classname(__first, __temp, __flags_ & icase);
-    if (__class_type == 0)
-        __throw_regex_error<regex_constants::error_ctype>();
-    __ml->__add_class(__class_type);
-    __first = _VSTD::next(__temp, 2);
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_collating_symbol(_ForwardIterator __first,
-                                                _ForwardIterator __last,
-                                                basic_string<_CharT>& __col_sym)
-{
-    // Found [.
-    //   This means .] must exist
-    value_type _Dot_close[2] = {'.', ']'};
-    _ForwardIterator __temp = _VSTD::search(__first, __last, _Dot_close,
-                                                            _Dot_close+2);
-    if (__temp == __last)
-        __throw_regex_error<regex_constants::error_brack>();
-    // [__first, __temp) contains all text in [. ... .]
-    __col_sym = __traits_.lookup_collatename(__first, __temp);
-    switch (__col_sym.size())
-    {
-    case 1:
-    case 2:
-        break;
-    default:
-        __throw_regex_error<regex_constants::error_collate>();
-    }
-    __first = _VSTD::next(__temp, 2);
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_DUP_COUNT(_ForwardIterator __first,
-                                                _ForwardIterator __last,
-                                                int& __c)
-{
-    if (__first != __last )
-    {
-        int __val = __traits_.value(*__first, 10);
-        if ( __val != -1 )
-        {
-            __c = __val;
-            for (++__first; 
-                 __first != __last && ( __val = __traits_.value(*__first, 10)) != -1;
-                 ++__first)
-            {
-                if (__c >= std::numeric_limits<int>::max() / 10)
-                    __throw_regex_error<regex_constants::error_badbrace>();
-                __c *= 10;
-                __c += __val;
-            }
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_ecma_exp(_ForwardIterator __first,
-                                               _ForwardIterator __last)
-{
-    __owns_one_state<_CharT>* __sa = __end_;
-    _ForwardIterator __temp = __parse_alternative(__first, __last);
-    if (__temp == __first)
-        __push_empty();
-    __first = __temp;
-    while (__first != __last && *__first == '|')
-    {
-        __owns_one_state<_CharT>* __sb = __end_;
-        __temp = __parse_alternative(++__first, __last);
-        if (__temp == __first)
-            __push_empty();
-        __push_alternation(__sa, __sb);
-        __first = __temp;
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_alternative(_ForwardIterator __first,
-                                                  _ForwardIterator __last)
-{
-    while (true)
-    {
-        _ForwardIterator __temp = __parse_term(__first, __last);
-        if (__temp == __first)
-            break;
-        __first = __temp;
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_term(_ForwardIterator __first,
-                                           _ForwardIterator __last)
-{
-    _ForwardIterator __temp = __parse_assertion(__first, __last);
-    if (__temp == __first)
-    {
-        __owns_one_state<_CharT>* __e = __end_;
-        unsigned __mexp_begin = __marked_count_;
-        __temp = __parse_atom(__first, __last);
-        if (__temp != __first)
-            __first = __parse_ERE_dupl_symbol(__temp, __last, __e,
-                                              __mexp_begin+1, __marked_count_+1);
-    }
-    else
-        __first = __temp;
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_assertion(_ForwardIterator __first,
-                                                _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        switch (*__first)
-        {
-        case '^':
-            __push_l_anchor();
-            ++__first;
-            break;
-        case '$':
-            __push_r_anchor();
-            ++__first;
-            break;
-        case '\\':
-            {
-                _ForwardIterator __temp = _VSTD::next(__first);
-                if (__temp != __last)
-                {
-                    if (*__temp == 'b')
-                    {
-                        __push_word_boundary(false);
-                        __first = ++__temp;
-                    }
-                    else if (*__temp == 'B')
-                    {
-                        __push_word_boundary(true);
-                        __first = ++__temp;
-                    }
-                }
-            }
-            break;
-        case '(':
-            {
-                _ForwardIterator __temp = _VSTD::next(__first);
-                if (__temp != __last && *__temp == '?')
-                {
-                    if (++__temp != __last)
-                    {
-                        switch (*__temp)
-                        {
-                        case '=':
-                            {
-                                basic_regex __exp;
-                                __exp.__flags_ = __flags_;
-                                __temp = __exp.__parse(++__temp, __last);
-                                unsigned __mexp = __exp.__marked_count_;
-                                __push_lookahead(_VSTD::move(__exp), false, __marked_count_);
-                                __marked_count_ += __mexp;
-                                if (__temp == __last || *__temp != ')')
-                                    __throw_regex_error<regex_constants::error_paren>();
-                                __first = ++__temp;
-                            }
-                            break;
-                        case '!':
-                            {
-                                basic_regex __exp;
-                                __exp.__flags_ = __flags_;
-                                __temp = __exp.__parse(++__temp, __last);
-                                unsigned __mexp = __exp.__marked_count_;
-                                __push_lookahead(_VSTD::move(__exp), true, __marked_count_);
-                                __marked_count_ += __mexp;
-                                if (__temp == __last || *__temp != ')')
-                                    __throw_regex_error<regex_constants::error_paren>();
-                                __first = ++__temp;
-                            }
-                            break;
-                        }
-                    }
-                }
-            }
-            break;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_atom(_ForwardIterator __first,
-                                           _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        switch (*__first)
-        {
-        case '.':
-            __push_match_any_but_newline();
-            ++__first;
-            break;
-        case '\\':
-            __first = __parse_atom_escape(__first, __last);
-            break;
-        case '[':
-            __first = __parse_bracket_expression(__first, __last);
-            break;
-        case '(':
-            {
-                ++__first;
-                if (__first == __last)
-                    __throw_regex_error<regex_constants::error_paren>();
-                _ForwardIterator __temp = _VSTD::next(__first);
-                if (__temp != __last && *__first == '?' && *__temp == ':')
-                {
-                    ++__open_count_;
-                    __first = __parse_ecma_exp(++__temp, __last);
-                    if (__first == __last || *__first != ')')
-                        __throw_regex_error<regex_constants::error_paren>();
-                    --__open_count_;
-                    ++__first;
-                }
-                else
-                {
-                    __push_begin_marked_subexpression();
-                    unsigned __temp_count = __marked_count_;
-                    ++__open_count_;
-                    __first = __parse_ecma_exp(__first, __last);
-                    if (__first == __last || *__first != ')')
-                        __throw_regex_error<regex_constants::error_paren>();
-                    __push_end_marked_subexpression(__temp_count);
-                    --__open_count_;
-                    ++__first;
-                }
-            }
-            break;
-        case '*':
-        case '+':
-        case '?':
-        case '{':
-            __throw_regex_error<regex_constants::error_badrepeat>();
-            break;
-        default:
-            __first = __parse_pattern_character(__first, __last);
-            break;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_atom_escape(_ForwardIterator __first,
-                                                  _ForwardIterator __last)
-{
-    if (__first != __last && *__first == '\\')
-    {
-        _ForwardIterator __t1 = _VSTD::next(__first);
-        if (__t1 == __last)
-            __throw_regex_error<regex_constants::error_escape>();
-
-        _ForwardIterator __t2 = __parse_decimal_escape(__t1, __last);
-        if (__t2 != __t1)
-            __first = __t2;
-        else
-        {
-            __t2 = __parse_character_class_escape(__t1, __last);
-            if (__t2 != __t1)
-                __first = __t2;
-            else
-            {
-                __t2 = __parse_character_escape(__t1, __last);
-                if (__t2 != __t1)
-                    __first = __t2;
-            }
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_decimal_escape(_ForwardIterator __first,
-                                                     _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        if (*__first == '0')
-        {
-            __push_char(_CharT());
-            ++__first;
-        }
-        else if ('1' <= *__first && *__first <= '9')
-        {
-            unsigned __v = *__first - '0';
-            for (++__first;
-                    __first != __last && '0' <= *__first && *__first <= '9'; ++__first)
-                {
-                if (__v >= std::numeric_limits<unsigned>::max() / 10)
-                    __throw_regex_error<regex_constants::error_backref>();
-                __v = 10 * __v + *__first - '0';
-                }
-            if (__v == 0 || __v > mark_count())
-                __throw_regex_error<regex_constants::error_backref>();
-            __push_back_ref(__v);
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_character_class_escape(_ForwardIterator __first,
-                                                             _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        __bracket_expression<_CharT, _Traits>* __ml;
-        switch (*__first)
-        {
-        case 'd':
-            __ml = __start_matching_list(false);
-            __ml->__add_class(ctype_base::digit);
-            ++__first;
-            break;
-        case 'D':
-            __ml = __start_matching_list(true);
-            __ml->__add_class(ctype_base::digit);
-            ++__first;
-            break;
-        case 's':
-            __ml = __start_matching_list(false);
-            __ml->__add_class(ctype_base::space);
-            ++__first;
-            break;
-        case 'S':
-            __ml = __start_matching_list(true);
-            __ml->__add_class(ctype_base::space);
-            ++__first;
-            break;
-        case 'w':
-            __ml = __start_matching_list(false);
-            __ml->__add_class(ctype_base::alnum);
-            __ml->__add_char('_');
-            ++__first;
-            break;
-        case 'W':
-            __ml = __start_matching_list(true);
-            __ml->__add_class(ctype_base::alnum);
-            __ml->__add_char('_');
-            ++__first;
-            break;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_character_escape(_ForwardIterator __first,
-                                                    _ForwardIterator __last,
-                                                    basic_string<_CharT>* __str)
-{
-    if (__first != __last)
-    {
-        _ForwardIterator __t;
-        unsigned __sum = 0;
-        int __hd;
-        switch (*__first)
-        {
-        case 'f':
-            if (__str)
-                *__str = _CharT(0xC);
-            else
-                __push_char(_CharT(0xC));
-            ++__first;
-            break;
-        case 'n':
-            if (__str)
-                *__str = _CharT(0xA);
-            else
-                __push_char(_CharT(0xA));
-            ++__first;
-            break;
-        case 'r':
-            if (__str)
-                *__str = _CharT(0xD);
-            else
-                __push_char(_CharT(0xD));
-            ++__first;
-            break;
-        case 't':
-            if (__str)
-                *__str = _CharT(0x9);
-            else
-                __push_char(_CharT(0x9));
-            ++__first;
-            break;
-        case 'v':
-            if (__str)
-                *__str = _CharT(0xB);
-            else
-                __push_char(_CharT(0xB));
-            ++__first;
-            break;
-        case 'c':
-            if ((__t = _VSTD::next(__first)) != __last)
-            {
-                if (('A' <= *__t && *__t <= 'Z') || 
-                    ('a' <= *__t && *__t <= 'z'))
-                {
-                    if (__str)
-                        *__str = _CharT(*__t % 32);
-                    else
-                        __push_char(_CharT(*__t % 32));
-                    __first = ++__t;
-                }
-                else 
-                    __throw_regex_error<regex_constants::error_escape>();
-            }
-            else
-                __throw_regex_error<regex_constants::error_escape>();
-            break;
-        case 'u':
-            ++__first;
-            if (__first == __last)
-                __throw_regex_error<regex_constants::error_escape>();
-            __hd = __traits_.value(*__first, 16);
-            if (__hd == -1)
-                __throw_regex_error<regex_constants::error_escape>();
-            __sum = 16 * __sum + static_cast<unsigned>(__hd);
-            ++__first;
-            if (__first == __last)
-                __throw_regex_error<regex_constants::error_escape>();
-            __hd = __traits_.value(*__first, 16);
-            if (__hd == -1)
-                __throw_regex_error<regex_constants::error_escape>();
-            __sum = 16 * __sum + static_cast<unsigned>(__hd);
-            // drop through
-        case 'x':
-            ++__first;
-            if (__first == __last)
-                __throw_regex_error<regex_constants::error_escape>();
-            __hd = __traits_.value(*__first, 16);
-            if (__hd == -1)
-                __throw_regex_error<regex_constants::error_escape>();
-            __sum = 16 * __sum + static_cast<unsigned>(__hd);
-            ++__first;
-            if (__first == __last)
-                __throw_regex_error<regex_constants::error_escape>();
-            __hd = __traits_.value(*__first, 16);
-            if (__hd == -1)
-                __throw_regex_error<regex_constants::error_escape>();
-            __sum = 16 * __sum + static_cast<unsigned>(__hd);
-            if (__str)
-                *__str = _CharT(__sum);
-            else
-                __push_char(_CharT(__sum));
-            ++__first;
-            break;
-        case '0':
-            if (__str)
-                *__str = _CharT(0);
-            else
-                __push_char(_CharT(0));
-            ++__first;
-            break;
-        default:
-            if (*__first != '_' && !__traits_.isctype(*__first, ctype_base::alnum))
-            {
-                if (__str)
-                    *__str = *__first;
-                else
-                    __push_char(*__first);
-                ++__first;
-            }
-            else
-                __throw_regex_error<regex_constants::error_escape>();
-            break;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_pattern_character(_ForwardIterator __first,
-                                                        _ForwardIterator __last)
-{
-    if (__first != __last)
-    {
-        switch (*__first)
-        {
-        case '^':
-        case '$':
-        case '\\':
-        case '.':
-        case '*':
-        case '+':
-        case '?':
-        case '(':
-        case ')':
-        case '[':
-        case ']':
-        case '{':
-        case '}':
-        case '|':
-            break;
-        default:
-            __push_char(*__first);
-            ++__first;
-            break;
-        }
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_grep(_ForwardIterator __first,
-                                           _ForwardIterator __last)
-{
-    __owns_one_state<_CharT>* __sa = __end_;
-    _ForwardIterator __t1 = _VSTD::find(__first, __last, _CharT('\n'));
-    if (__t1 != __first)
-        __parse_basic_reg_exp(__first, __t1);
-    else
-        __push_empty();
-    __first = __t1;
-    if (__first != __last)
-        ++__first;
-    while (__first != __last)
-    {
-        __t1 = _VSTD::find(__first, __last, _CharT('\n'));
-        __owns_one_state<_CharT>* __sb = __end_;
-        if (__t1 != __first)
-            __parse_basic_reg_exp(__first, __t1);
-        else
-            __push_empty();
-        __push_alternation(__sa, __sb);
-        __first = __t1;
-        if (__first != __last)
-            ++__first;
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-template <class _ForwardIterator>
-_ForwardIterator
-basic_regex<_CharT, _Traits>::__parse_egrep(_ForwardIterator __first,
-                                            _ForwardIterator __last)
-{
-    __owns_one_state<_CharT>* __sa = __end_;
-    _ForwardIterator __t1 = _VSTD::find(__first, __last, _CharT('\n'));
-    if (__t1 != __first)
-        __parse_extended_reg_exp(__first, __t1);
-    else
-        __push_empty();
-    __first = __t1;
-    if (__first != __last)
-        ++__first;
-    while (__first != __last)
-    {
-        __t1 = _VSTD::find(__first, __last, _CharT('\n'));
-        __owns_one_state<_CharT>* __sb = __end_;
-        if (__t1 != __first)
-            __parse_extended_reg_exp(__first, __t1);
-        else
-            __push_empty();
-        __push_alternation(__sa, __sb);
-        __first = __t1;
-        if (__first != __last)
-            ++__first;
-    }
-    return __first;
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_loop(size_t __min, size_t __max,
-        __owns_one_state<_CharT>* __s, size_t __mexp_begin, size_t __mexp_end,
-        bool __greedy)
-{
-    unique_ptr<__empty_state<_CharT> > __e1(new __empty_state<_CharT>(__end_->first()));
-    __end_->first() = nullptr;
-    unique_ptr<__loop<_CharT> > __e2(new __loop<_CharT>(__loop_count_,
-                __s->first(), __e1.get(), __mexp_begin, __mexp_end, __greedy,
-                __min, __max));
-    __s->first() = nullptr;
-    __e1.release();
-    __end_->first() = new __repeat_one_loop<_CharT>(__e2.get());
-    __end_ = __e2->second();
-    __s->first() = __e2.release();
-    ++__loop_count_;
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_char(value_type __c)
-{
-    if (flags() & icase)
-        __end_->first() = new __match_char_icase<_CharT, _Traits>
-                                              (__traits_, __c, __end_->first());
-    else if (flags() & collate)
-        __end_->first() = new __match_char_collate<_CharT, _Traits>
-                                              (__traits_, __c, __end_->first());
-    else
-        __end_->first() = new __match_char<_CharT>(__c, __end_->first());
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_begin_marked_subexpression()
-{
-    if (!(__flags_ & nosubs))
-    {
-        __end_->first() =
-                new __begin_marked_subexpression<_CharT>(++__marked_count_,
-                                                         __end_->first());
-        __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-    }
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_end_marked_subexpression(unsigned __sub)
-{
-    if (!(__flags_ & nosubs))
-    {
-        __end_->first() =
-                new __end_marked_subexpression<_CharT>(__sub, __end_->first());
-        __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-    }
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_l_anchor()
-{
-    __end_->first() = new __l_anchor<_CharT>(__end_->first());
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_r_anchor()
-{
-    __end_->first() = new __r_anchor<_CharT>(__end_->first());
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_match_any()
-{
-    __end_->first() = new __match_any<_CharT>(__end_->first());
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_match_any_but_newline()
-{
-    __end_->first() = new __match_any_but_newline<_CharT>(__end_->first());
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_empty()
-{
-    __end_->first() = new __empty_state<_CharT>(__end_->first());
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_word_boundary(bool __invert)
-{
-    __end_->first() = new __word_boundary<_CharT, _Traits>(__traits_, __invert,
-                                                           __end_->first());
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_back_ref(int __i)
-{
-    if (flags() & icase)
-        __end_->first() = new __back_ref_icase<_CharT, _Traits>
-                                              (__traits_, __i, __end_->first());
-    else if (flags() & collate)
-        __end_->first() = new __back_ref_collate<_CharT, _Traits>
-                                              (__traits_, __i, __end_->first());
-    else
-        __end_->first() = new __back_ref<_CharT>(__i, __end_->first());
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_alternation(__owns_one_state<_CharT>* __sa,
-                                                 __owns_one_state<_CharT>* __ea)
-{
-    __sa->first() = new __alternate<_CharT>(
-                         static_cast<__owns_one_state<_CharT>*>(__sa->first()),
-                         static_cast<__owns_one_state<_CharT>*>(__ea->first()));
-    __ea->first() = nullptr;
-    __ea->first() = new __empty_state<_CharT>(__end_->first());
-    __end_->first() = nullptr;
-    __end_->first() = new __empty_non_own_state<_CharT>(__ea->first());
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__ea->first());
-}
-
-template <class _CharT, class _Traits>
-__bracket_expression<_CharT, _Traits>*
-basic_regex<_CharT, _Traits>::__start_matching_list(bool __negate)
-{
-    __bracket_expression<_CharT, _Traits>* __r =
-        new __bracket_expression<_CharT, _Traits>(__traits_, __end_->first(),
-                                                  __negate, __flags_ & icase,
-                                                  __flags_ & collate);
-    __end_->first() = __r;
-    __end_ = __r;
-    return __r;
-}
-
-template <class _CharT, class _Traits>
-void
-basic_regex<_CharT, _Traits>::__push_lookahead(const basic_regex& __exp,
-                                               bool __invert,
-                                               unsigned __mexp)
-{
-    __end_->first() = new __lookahead<_CharT, _Traits>(__exp, __invert,
-                                                           __end_->first(), __mexp);
-    __end_ = static_cast<__owns_one_state<_CharT>*>(__end_->first());
-}
-
-typedef basic_regex<char>    regex;
-typedef basic_regex<wchar_t> wregex;
-
-// sub_match
-
-template <class _BidirectionalIterator>
-class _LIBCPP_TEMPLATE_VIS sub_match
-    : public pair<_BidirectionalIterator, _BidirectionalIterator>
-{
-public:
-    typedef _BidirectionalIterator                              iterator;
-    typedef typename iterator_traits<iterator>::value_type      value_type;
-    typedef typename iterator_traits<iterator>::difference_type difference_type;
-    typedef basic_string<value_type>                            string_type;
-
-    bool matched;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR sub_match() : matched() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    difference_type length() const
-        {return matched ? _VSTD::distance(this->first, this->second) : 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    string_type str() const
-        {return matched ? string_type(this->first, this->second) : string_type();}
-    _LIBCPP_INLINE_VISIBILITY
-    operator string_type() const
-        {return str();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    int compare(const sub_match& __s) const
-        {return str().compare(__s.str());}
-    _LIBCPP_INLINE_VISIBILITY
-    int compare(const string_type& __s) const
-        {return str().compare(__s);}
-    _LIBCPP_INLINE_VISIBILITY
-    int compare(const value_type* __s) const
-        {return str().compare(__s);}
-};
-
-typedef sub_match<const char*>             csub_match;
-typedef sub_match<const wchar_t*>          wcsub_match;
-typedef sub_match<string::const_iterator>  ssub_match;
-typedef sub_match<wstring::const_iterator> wssub_match;
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const sub_match<_BiIter>& __x, const sub_match<_BiIter>& __y)
-{
-    return __x.compare(__y) == 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const sub_match<_BiIter>& __x, const sub_match<_BiIter>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const sub_match<_BiIter>& __x, const sub_match<_BiIter>& __y)
-{
-    return __x.compare(__y) < 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const sub_match<_BiIter>& __x, const sub_match<_BiIter>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const sub_match<_BiIter>& __x, const sub_match<_BiIter>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(const sub_match<_BiIter>& __x, const sub_match<_BiIter>& __y)
-{
-    return __y < __x;
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __x,
-           const sub_match<_BiIter>& __y)
-{
-    return __y.compare(typename sub_match<_BiIter>::string_type(__x.data(), __x.size())) == 0;
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __x,
-           const sub_match<_BiIter>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __x,
-          const sub_match<_BiIter>& __y)
-{
-    return __y.compare(typename sub_match<_BiIter>::string_type(__x.data(), __x.size())) > 0;
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __x,
-          const sub_match<_BiIter>& __y)
-{
-    return __y < __x;
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator>=(const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __x,
-                const sub_match<_BiIter>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __x,
-           const sub_match<_BiIter>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const sub_match<_BiIter>& __x,
-           const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __y)
-{
-    return __x.compare(typename sub_match<_BiIter>::string_type(__y.data(), __y.size())) == 0;
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const sub_match<_BiIter>& __x,
-           const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const sub_match<_BiIter>& __x,
-          const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __y)
-{
-    return __x.compare(typename sub_match<_BiIter>::string_type(__y.data(), __y.size())) < 0;
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator>(const sub_match<_BiIter>& __x,
-               const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __y)
-{
-    return __y < __x;
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const sub_match<_BiIter>& __x,
-           const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _BiIter, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const sub_match<_BiIter>& __x,
-           const basic_string<typename iterator_traits<_BiIter>::value_type, _ST, _SA>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(typename iterator_traits<_BiIter>::value_type const* __x,
-           const sub_match<_BiIter>& __y)
-{
-    return __y.compare(__x) == 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(typename iterator_traits<_BiIter>::value_type const* __x,
-           const sub_match<_BiIter>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(typename iterator_traits<_BiIter>::value_type const* __x,
-          const sub_match<_BiIter>& __y)
-{
-    return __y.compare(__x) > 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(typename iterator_traits<_BiIter>::value_type const* __x,
-          const sub_match<_BiIter>& __y)
-{
-    return __y < __x;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(typename iterator_traits<_BiIter>::value_type const* __x,
-           const sub_match<_BiIter>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(typename iterator_traits<_BiIter>::value_type const* __x,
-           const sub_match<_BiIter>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const sub_match<_BiIter>& __x,
-           typename iterator_traits<_BiIter>::value_type const* __y)
-{
-    return __x.compare(__y) == 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const sub_match<_BiIter>& __x,
-           typename iterator_traits<_BiIter>::value_type const* __y)
-{
-    return !(__x == __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const sub_match<_BiIter>& __x,
-          typename iterator_traits<_BiIter>::value_type const* __y)
-{
-    return __x.compare(__y) < 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(const sub_match<_BiIter>& __x,
-          typename iterator_traits<_BiIter>::value_type const* __y)
-{
-    return __y < __x;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const sub_match<_BiIter>& __x,
-           typename iterator_traits<_BiIter>::value_type const* __y)
-{
-    return !(__x < __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const sub_match<_BiIter>& __x,
-           typename iterator_traits<_BiIter>::value_type const* __y)
-{
-    return !(__y < __x);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(typename iterator_traits<_BiIter>::value_type const& __x,
-           const sub_match<_BiIter>& __y)
-{
-    typedef basic_string<typename iterator_traits<_BiIter>::value_type> string_type;
-    return __y.compare(string_type(1, __x)) == 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(typename iterator_traits<_BiIter>::value_type const& __x,
-           const sub_match<_BiIter>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(typename iterator_traits<_BiIter>::value_type const& __x,
-          const sub_match<_BiIter>& __y)
-{
-    typedef basic_string<typename iterator_traits<_BiIter>::value_type> string_type;
-    return __y.compare(string_type(1, __x)) > 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(typename iterator_traits<_BiIter>::value_type const& __x,
-          const sub_match<_BiIter>& __y)
-{
-    return __y < __x;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(typename iterator_traits<_BiIter>::value_type const& __x,
-           const sub_match<_BiIter>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(typename iterator_traits<_BiIter>::value_type const& __x,
-           const sub_match<_BiIter>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const sub_match<_BiIter>& __x,
-           typename iterator_traits<_BiIter>::value_type const& __y)
-{
-    typedef basic_string<typename iterator_traits<_BiIter>::value_type> string_type;
-    return __x.compare(string_type(1, __y)) == 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const sub_match<_BiIter>& __x,
-           typename iterator_traits<_BiIter>::value_type const& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const sub_match<_BiIter>& __x,
-          typename iterator_traits<_BiIter>::value_type const& __y)
-{
-    typedef basic_string<typename iterator_traits<_BiIter>::value_type> string_type;
-    return __x.compare(string_type(1, __y)) < 0;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>(const sub_match<_BiIter>& __x,
-          typename iterator_traits<_BiIter>::value_type const& __y)
-{
-    return __y < __x;
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const sub_match<_BiIter>& __x,
-           typename iterator_traits<_BiIter>::value_type const& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const sub_match<_BiIter>& __x,
-           typename iterator_traits<_BiIter>::value_type const& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _CharT, class _ST, class _BiIter>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_ostream<_CharT, _ST>&
-operator<<(basic_ostream<_CharT, _ST>& __os, const sub_match<_BiIter>& __m)
-{
-    return __os << __m.str();
-}
-
-template <class _BidirectionalIterator, class _Allocator>
-class _LIBCPP_TEMPLATE_VIS match_results
-{
-public:
-    typedef _Allocator                                        allocator_type;
-    typedef sub_match<_BidirectionalIterator>                 value_type;
-private:
-    typedef vector<value_type, allocator_type>                __container_type;
-
-    __container_type  __matches_;
-    value_type __unmatched_;
-    value_type __prefix_;
-    value_type __suffix_;
-    bool       __ready_;
-public:
-    _BidirectionalIterator __position_start_;
-    typedef const value_type&                                 const_reference;
-    typedef value_type&                                       reference;
-    typedef typename __container_type::const_iterator         const_iterator;
-    typedef const_iterator                                    iterator;
-    typedef typename iterator_traits<_BidirectionalIterator>::difference_type difference_type;
-    typedef typename allocator_traits<allocator_type>::size_type size_type;
-    typedef typename iterator_traits<_BidirectionalIterator>::value_type char_type;
-    typedef basic_string<char_type>                           string_type;
-
-    // construct/copy/destroy:
-    explicit match_results(const allocator_type& __a = allocator_type());
-//    match_results(const match_results&) = default;
-//    match_results& operator=(const match_results&) = default;
-//    match_results(match_results&& __m) = default;
-//    match_results& operator=(match_results&& __m) = default;
-//    ~match_results() = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool ready() const {return __ready_;}
-
-    // size:
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT {return __matches_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {return __matches_.max_size();}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT {return size() == 0;}
-
-    // element access:
-    _LIBCPP_INLINE_VISIBILITY
-    difference_type length(size_type __sub = 0) const
-        {return (*this)[__sub].length();}
-    _LIBCPP_INLINE_VISIBILITY
-    difference_type position(size_type __sub = 0) const
-        {return _VSTD::distance(__position_start_, (*this)[__sub].first);}
-    _LIBCPP_INLINE_VISIBILITY
-    string_type str(size_type __sub = 0) const
-        {return (*this)[__sub].str();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference operator[](size_type __n) const
-        {return __n < __matches_.size() ? __matches_[__n] : __unmatched_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference prefix() const {return __prefix_;}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference suffix() const {return __suffix_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const {return empty() ? __matches_.end() : __matches_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const {return __matches_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const {return empty() ? __matches_.end() : __matches_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend() const {return __matches_.end();}
-
-    // format:
-    template <class _OutputIter>
-        _OutputIter
-        format(_OutputIter __output_iter, const char_type* __fmt_first,
-               const char_type* __fmt_last,
-               regex_constants::match_flag_type __flags = regex_constants::format_default) const;
-    template <class _OutputIter, class _ST, class _SA>
-        _LIBCPP_INLINE_VISIBILITY
-        _OutputIter
-        format(_OutputIter __output_iter, const basic_string<char_type, _ST, _SA>& __fmt,
-               regex_constants::match_flag_type __flags = regex_constants::format_default) const
-            {return format(__output_iter, __fmt.data(), __fmt.data() + __fmt.size(), __flags);}
-    template <class _ST, class _SA>
-        _LIBCPP_INLINE_VISIBILITY
-        basic_string<char_type, _ST, _SA>
-        format(const basic_string<char_type, _ST, _SA>& __fmt,
-               regex_constants::match_flag_type __flags = regex_constants::format_default) const
-        {
-            basic_string<char_type, _ST, _SA> __r;
-            format(back_inserter(__r), __fmt.data(), __fmt.data() + __fmt.size(),
-                   __flags);
-            return __r;
-        }
-    _LIBCPP_INLINE_VISIBILITY
-    string_type
-        format(const char_type* __fmt,
-               regex_constants::match_flag_type __flags = regex_constants::format_default) const
-        {
-            string_type __r;
-            format(back_inserter(__r), __fmt,
-                   __fmt + char_traits<char_type>::length(__fmt), __flags);
-            return __r;
-        }
-
-    // allocator:
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const {return __matches_.get_allocator();}
-
-    // swap:
-    void swap(match_results& __m);
-
-    template <class _Bp, class _Ap>
-        _LIBCPP_INLINE_VISIBILITY
-        void __assign(_BidirectionalIterator __f, _BidirectionalIterator __l,
-                      const match_results<_Bp, _Ap>& __m, bool __no_update_pos)
-    {
-        _Bp __mf = __m.prefix().first;
-        __matches_.resize(__m.size());
-        for (size_type __i = 0; __i < __matches_.size(); ++__i)
-        {
-            __matches_[__i].first = _VSTD::next(__f, _VSTD::distance(__mf, __m[__i].first));
-            __matches_[__i].second = _VSTD::next(__f, _VSTD::distance(__mf, __m[__i].second));
-            __matches_[__i].matched = __m[__i].matched;
-        }
-        __unmatched_.first   = __l;
-        __unmatched_.second  = __l;
-        __unmatched_.matched = false;
-        __prefix_.first = _VSTD::next(__f, _VSTD::distance(__mf, __m.prefix().first));
-        __prefix_.second = _VSTD::next(__f, _VSTD::distance(__mf, __m.prefix().second));
-        __prefix_.matched = __m.prefix().matched;
-        __suffix_.first = _VSTD::next(__f, _VSTD::distance(__mf, __m.suffix().first));
-        __suffix_.second = _VSTD::next(__f, _VSTD::distance(__mf, __m.suffix().second));
-        __suffix_.matched = __m.suffix().matched;
-        if (!__no_update_pos)
-            __position_start_ = __prefix_.first;
-        __ready_ = __m.ready();
-    }
-
-private:
-    void __init(unsigned __s,
-                _BidirectionalIterator __f, _BidirectionalIterator __l,
-                bool __no_update_pos = false);
-
-    template <class, class> friend class basic_regex;
-
-    template <class _Bp, class _Ap, class _Cp, class _Tp>
-    friend
-    bool
-    regex_match(_Bp, _Bp, match_results<_Bp, _Ap>&, const basic_regex<_Cp, _Tp>&,
-                regex_constants::match_flag_type);
-
-    template <class _Bp, class _Ap>
-    friend
-    bool
-    operator==(const match_results<_Bp, _Ap>&, const match_results<_Bp, _Ap>&);
-
-    template <class, class> friend class __lookahead;
-};
-
-template <class _BidirectionalIterator, class _Allocator>
-match_results<_BidirectionalIterator, _Allocator>::match_results(
-        const allocator_type& __a)
-    : __matches_(__a),
-      __unmatched_(),
-      __prefix_(),
-      __suffix_(),
-      __ready_(false),
-      __position_start_()
-{
-}
-
-template <class _BidirectionalIterator, class _Allocator>
-void
-match_results<_BidirectionalIterator, _Allocator>::__init(unsigned __s,
-                         _BidirectionalIterator __f, _BidirectionalIterator __l,
-                         bool __no_update_pos)
-{
-    __unmatched_.first   = __l;
-    __unmatched_.second  = __l;
-    __unmatched_.matched = false;
-    __matches_.assign(__s, __unmatched_);
-    __prefix_.first      = __f;
-    __prefix_.second     = __f;
-    __prefix_.matched    = false;
-    __suffix_ = __unmatched_;
-    if (!__no_update_pos)
-        __position_start_ = __prefix_.first;
-    __ready_ = true;
-}
-
-template <class _BidirectionalIterator, class _Allocator>
-template <class _OutputIter>
-_OutputIter
-match_results<_BidirectionalIterator, _Allocator>::format(_OutputIter __output_iter,
-        const char_type* __fmt_first, const char_type* __fmt_last,
-        regex_constants::match_flag_type __flags) const
-{
-    if (__flags & regex_constants::format_sed)
-    {
-        for (; __fmt_first != __fmt_last; ++__fmt_first)
-        {
-            if (*__fmt_first == '&')
-                __output_iter = _VSTD::copy(__matches_[0].first, __matches_[0].second,
-                                   __output_iter);
-            else if (*__fmt_first == '\\' && __fmt_first + 1 != __fmt_last)
-            {
-                ++__fmt_first;
-                if ('0' <= *__fmt_first && *__fmt_first <= '9')
-                {
-                    size_t __i = *__fmt_first - '0';
-                    __output_iter = _VSTD::copy((*this)[__i].first,
-                                        (*this)[__i].second, __output_iter);
-                }
-                else
-                {
-                    *__output_iter = *__fmt_first;
-                    ++__output_iter;
-                }
-            }
-            else
-            {
-                *__output_iter = *__fmt_first;
-                ++__output_iter;
-            }
-        }
-    }
-    else
-    {
-        for (; __fmt_first != __fmt_last; ++__fmt_first)
-        {
-            if (*__fmt_first == '$' && __fmt_first + 1 != __fmt_last)
-            {
-                switch (__fmt_first[1])
-                {
-                case '$':
-                    *__output_iter = *++__fmt_first;
-                    ++__output_iter;
-                    break;
-                case '&':
-                    ++__fmt_first;
-                    __output_iter = _VSTD::copy(__matches_[0].first, __matches_[0].second,
-                                       __output_iter);
-                    break;
-                case '`':
-                    ++__fmt_first;
-                    __output_iter = _VSTD::copy(__prefix_.first, __prefix_.second, __output_iter);
-                    break;
-                case '\'':
-                    ++__fmt_first;
-                    __output_iter = _VSTD::copy(__suffix_.first, __suffix_.second, __output_iter);
-                    break;
-                default:
-                    if ('0' <= __fmt_first[1] && __fmt_first[1] <= '9')
-                    {
-                        ++__fmt_first;
-                        size_t __idx = *__fmt_first - '0';
-                        if (__fmt_first + 1 != __fmt_last &&
-                            '0' <= __fmt_first[1] && __fmt_first[1] <= '9')
-                        {
-                            ++__fmt_first;
-                            if (__idx >= std::numeric_limits<size_t>::max() / 10)
-                                __throw_regex_error<regex_constants::error_escape>();
-                            __idx = 10 * __idx + *__fmt_first - '0';
-                        }
-                        __output_iter = _VSTD::copy((*this)[__idx].first,
-                                            (*this)[__idx].second, __output_iter);
-                    }
-                    else
-                    {
-                        *__output_iter = *__fmt_first;
-                        ++__output_iter;
-                    }
-                    break;
-                }
-            }
-            else
-            {
-                *__output_iter = *__fmt_first;
-                ++__output_iter;
-            }
-        }
-    }
-    return __output_iter;
-}
-
-template <class _BidirectionalIterator, class _Allocator>
-void
-match_results<_BidirectionalIterator, _Allocator>::swap(match_results& __m)
-{
-    using _VSTD::swap;
-    swap(__matches_, __m.__matches_);
-    swap(__unmatched_, __m.__unmatched_);
-    swap(__prefix_, __m.__prefix_);
-    swap(__suffix_, __m.__suffix_);
-    swap(__position_start_, __m.__position_start_);
-    swap(__ready_, __m.__ready_);
-}
-
-typedef match_results<const char*>             cmatch;
-typedef match_results<const wchar_t*>          wcmatch;
-typedef match_results<string::const_iterator>  smatch;
-typedef match_results<wstring::const_iterator> wsmatch;
-
-template <class _BidirectionalIterator, class _Allocator>
-bool
-operator==(const match_results<_BidirectionalIterator, _Allocator>& __x,
-           const match_results<_BidirectionalIterator, _Allocator>& __y)
-{
-    if (__x.__ready_ != __y.__ready_)
-        return false;
-    if (!__x.__ready_)
-        return true;
-    return __x.__matches_ == __y.__matches_ &&
-           __x.__prefix_ == __y.__prefix_ &&
-           __x.__suffix_ == __y.__suffix_;
-}
-
-template <class _BidirectionalIterator, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const match_results<_BidirectionalIterator, _Allocator>& __x,
-           const match_results<_BidirectionalIterator, _Allocator>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _BidirectionalIterator, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(match_results<_BidirectionalIterator, _Allocator>& __x,
-     match_results<_BidirectionalIterator, _Allocator>& __y)
-{
-    __x.swap(__y);
-}
-
-// regex_search
-
-template <class _CharT, class _Traits>
-template <class _Allocator>
-bool
-basic_regex<_CharT, _Traits>::__match_at_start_ecma(
-        const _CharT* __first, const _CharT* __last,
-        match_results<const _CharT*, _Allocator>& __m,
-        regex_constants::match_flag_type __flags, bool __at_first) const
-{
-    vector<__state> __states;
-    __node* __st = __start_.get();
-    if (__st)
-    {
-        sub_match<const _CharT*> __unmatched;
-        __unmatched.first   = __last;
-        __unmatched.second  = __last;
-        __unmatched.matched = false;
-
-        __states.push_back(__state());
-        __states.back().__do_ = 0;
-        __states.back().__first_ = __first;
-        __states.back().__current_ = __first;
-        __states.back().__last_ = __last;
-        __states.back().__sub_matches_.resize(mark_count(), __unmatched);
-        __states.back().__loop_data_.resize(__loop_count());
-        __states.back().__node_ = __st;
-        __states.back().__flags_ = __flags;
-        __states.back().__at_first_ = __at_first;
-        int __counter = 0;
-        int __length = __last - __first;
-        do
-        {
-            ++__counter;
-            if (__counter % _LIBCPP_REGEX_COMPLEXITY_FACTOR == 0 &&
-                __counter / _LIBCPP_REGEX_COMPLEXITY_FACTOR >= __length)
-              __throw_regex_error<regex_constants::error_complexity>();
-            __state& __s = __states.back();
-            if (__s.__node_)
-                __s.__node_->__exec(__s);
-            switch (__s.__do_)
-            {
-            case __state::__end_state:
-                if ((__flags & regex_constants::match_not_null) &&
-                    __s.__current_ == __first)
-                {
-                  __states.pop_back();
-                  break;
-                }
-                if ((__flags & regex_constants::__full_match) &&
-                    __s.__current_ != __last)
-                {
-                  __states.pop_back();
-                  break;
-                }
-                __m.__matches_[0].first = __first;
-                __m.__matches_[0].second = _VSTD::next(__first, __s.__current_ - __first);
-                __m.__matches_[0].matched = true;
-                for (unsigned __i = 0; __i < __s.__sub_matches_.size(); ++__i)
-                    __m.__matches_[__i+1] = __s.__sub_matches_[__i];
-                return true;
-            case __state::__accept_and_consume:
-            case __state::__repeat:
-            case __state::__accept_but_not_consume:
-                break;
-            case __state::__split:
-                {
-                __state __snext = __s;
-                __s.__node_->__exec_split(true, __s);
-                __snext.__node_->__exec_split(false, __snext);
-                __states.push_back(_VSTD::move(__snext));
-                }
-                break;
-            case __state::__reject:
-                __states.pop_back();
-                break;
-            default:
-                __throw_regex_error<regex_constants::__re_err_unknown>();
-                break;
-
-            }
-        } while (!__states.empty());
-    }
-    return false;
-}
-
-template <class _CharT, class _Traits>
-template <class _Allocator>
-bool
-basic_regex<_CharT, _Traits>::__match_at_start_posix_nosubs(
-        const _CharT* __first, const _CharT* __last,
-        match_results<const _CharT*, _Allocator>& __m,
-        regex_constants::match_flag_type __flags, bool __at_first) const
-{
-    deque<__state> __states;
-    ptrdiff_t __highest_j = 0;
-    ptrdiff_t _Np = _VSTD::distance(__first, __last);
-    __node* __st = __start_.get();
-    if (__st)
-    {
-        __states.push_back(__state());
-        __states.back().__do_ = 0;
-        __states.back().__first_ = __first;
-        __states.back().__current_ = __first;
-        __states.back().__last_ = __last;
-        __states.back().__loop_data_.resize(__loop_count());
-        __states.back().__node_ = __st;
-        __states.back().__flags_ = __flags;
-        __states.back().__at_first_ = __at_first;
-        bool __matched = false;
-        int __counter = 0;
-        int __length = __last - __first;
-        do
-        {
-            ++__counter;
-            if (__counter % _LIBCPP_REGEX_COMPLEXITY_FACTOR == 0 &&
-                __counter / _LIBCPP_REGEX_COMPLEXITY_FACTOR >= __length)
-              __throw_regex_error<regex_constants::error_complexity>();
-            __state& __s = __states.back();
-            if (__s.__node_)
-                __s.__node_->__exec(__s);
-            switch (__s.__do_)
-            {
-            case __state::__end_state:
-                if ((__flags & regex_constants::match_not_null) &&
-                    __s.__current_ == __first)
-                {
-                  __states.pop_back();
-                  break;
-                }
-                if ((__flags & regex_constants::__full_match) &&
-                    __s.__current_ != __last)
-                {
-                  __states.pop_back();
-                  break;
-                }
-                if (!__matched || __highest_j < __s.__current_ - __s.__first_)
-                    __highest_j = __s.__current_ - __s.__first_;
-                __matched = true;
-                if (__highest_j == _Np)
-                    __states.clear();
-                else
-                    __states.pop_back();
-                break;
-            case __state::__consume_input:
-                break;
-            case __state::__accept_and_consume:
-                __states.push_front(_VSTD::move(__s));
-                __states.pop_back();
-                break;
-            case __state::__repeat:
-            case __state::__accept_but_not_consume:
-                break;
-            case __state::__split:
-                {
-                __state __snext = __s;
-                __s.__node_->__exec_split(true, __s);
-                __snext.__node_->__exec_split(false, __snext);
-                __states.push_back(_VSTD::move(__snext));
-                }
-                break;
-            case __state::__reject:
-                __states.pop_back();
-                break;
-            default:
-                __throw_regex_error<regex_constants::__re_err_unknown>();
-                break;
-            }
-        } while (!__states.empty());
-        if (__matched)
-        {
-            __m.__matches_[0].first = __first;
-            __m.__matches_[0].second = _VSTD::next(__first, __highest_j);
-            __m.__matches_[0].matched = true;
-            return true;
-        }
-    }
-    return false;
-}
-
-template <class _CharT, class _Traits>
-template <class _Allocator>
-bool
-basic_regex<_CharT, _Traits>::__match_at_start_posix_subs(
-        const _CharT* __first, const _CharT* __last,
-        match_results<const _CharT*, _Allocator>& __m,
-        regex_constants::match_flag_type __flags, bool __at_first) const
-{
-    vector<__state> __states;
-    __state __best_state;
-    ptrdiff_t __j = 0;
-    ptrdiff_t __highest_j = 0;
-    ptrdiff_t _Np = _VSTD::distance(__first, __last);
-    __node* __st = __start_.get();
-    if (__st)
-    {
-        sub_match<const _CharT*> __unmatched;
-        __unmatched.first   = __last;
-        __unmatched.second  = __last;
-        __unmatched.matched = false;
-
-        __states.push_back(__state());
-        __states.back().__do_ = 0;
-        __states.back().__first_ = __first;
-        __states.back().__current_ = __first;
-        __states.back().__last_ = __last;
-        __states.back().__sub_matches_.resize(mark_count(), __unmatched);
-        __states.back().__loop_data_.resize(__loop_count());
-        __states.back().__node_ = __st;
-        __states.back().__flags_ = __flags;
-        __states.back().__at_first_ = __at_first;
-        const _CharT* __current = __first;
-        bool __matched = false;
-        int __counter = 0;
-        int __length = __last - __first;
-        do
-        {
-            ++__counter;
-            if (__counter % _LIBCPP_REGEX_COMPLEXITY_FACTOR == 0 &&
-                __counter / _LIBCPP_REGEX_COMPLEXITY_FACTOR >= __length)
-              __throw_regex_error<regex_constants::error_complexity>();
-            __state& __s = __states.back();
-            if (__s.__node_)
-                __s.__node_->__exec(__s);
-            switch (__s.__do_)
-            {
-            case __state::__end_state:
-                if ((__flags & regex_constants::match_not_null) &&
-                    __s.__current_ == __first)
-                {
-                  __states.pop_back();
-                  break;
-                }
-                if ((__flags & regex_constants::__full_match) &&
-                    __s.__current_ != __last)
-                {
-                  __states.pop_back();
-                  break;
-                }
-                if (!__matched || __highest_j < __s.__current_ - __s.__first_)
-                {
-                    __highest_j = __s.__current_ - __s.__first_;
-                    __best_state = __s;
-                }
-                __matched = true;
-                if (__highest_j == _Np)
-                    __states.clear();
-                else
-                    __states.pop_back();
-                break;
-            case __state::__accept_and_consume:
-                __j += __s.__current_ - __current;
-                __current = __s.__current_;
-                break;
-            case __state::__repeat:
-            case __state::__accept_but_not_consume:
-                break;
-            case __state::__split:
-                {
-                __state __snext = __s;
-                __s.__node_->__exec_split(true, __s);
-                __snext.__node_->__exec_split(false, __snext);
-                __states.push_back(_VSTD::move(__snext));
-                }
-                break;
-            case __state::__reject:
-                __states.pop_back();
-                break;
-            default:
-                __throw_regex_error<regex_constants::__re_err_unknown>();
-                break;
-            }
-        } while (!__states.empty());
-        if (__matched)
-        {
-            __m.__matches_[0].first = __first;
-            __m.__matches_[0].second = _VSTD::next(__first, __highest_j);
-            __m.__matches_[0].matched = true;
-            for (unsigned __i = 0; __i < __best_state.__sub_matches_.size(); ++__i)
-                __m.__matches_[__i+1] = __best_state.__sub_matches_[__i];
-            return true;
-        }
-    }
-    return false;
-}
-
-template <class _CharT, class _Traits>
-template <class _Allocator>
-bool
-basic_regex<_CharT, _Traits>::__match_at_start(
-        const _CharT* __first, const _CharT* __last,
-        match_results<const _CharT*, _Allocator>& __m,
-        regex_constants::match_flag_type __flags, bool __at_first) const
-{
-    if ((__flags_ & 0x1F0) == ECMAScript)
-        return __match_at_start_ecma(__first, __last, __m, __flags, __at_first);
-    if (mark_count() == 0)
-        return __match_at_start_posix_nosubs(__first, __last, __m, __flags, __at_first);
-    return __match_at_start_posix_subs(__first, __last, __m, __flags, __at_first);
-}
-
-template <class _CharT, class _Traits>
-template <class _Allocator>
-bool
-basic_regex<_CharT, _Traits>::__search(
-        const _CharT* __first, const _CharT* __last,
-        match_results<const _CharT*, _Allocator>& __m,
-        regex_constants::match_flag_type __flags) const
-{
-    __m.__init(1 + mark_count(), __first, __last,
-                                    __flags & regex_constants::__no_update_pos);
-    if (__match_at_start(__first, __last, __m, __flags, 
-                                    !(__flags & regex_constants::__no_update_pos)))
-    {
-        __m.__prefix_.second = __m[0].first;
-        __m.__prefix_.matched = __m.__prefix_.first != __m.__prefix_.second;
-        __m.__suffix_.first = __m[0].second;
-        __m.__suffix_.matched = __m.__suffix_.first != __m.__suffix_.second;
-        return true;
-    }
-    if (__first != __last && !(__flags & regex_constants::match_continuous))
-    {
-        __flags |= regex_constants::match_prev_avail;
-        for (++__first; __first != __last; ++__first)
-        {
-            __m.__matches_.assign(__m.size(), __m.__unmatched_);
-            if (__match_at_start(__first, __last, __m, __flags, false))
-            {
-                __m.__prefix_.second = __m[0].first;
-                __m.__prefix_.matched = __m.__prefix_.first != __m.__prefix_.second;
-                __m.__suffix_.first = __m[0].second;
-                __m.__suffix_.matched = __m.__suffix_.first != __m.__suffix_.second;
-                return true;
-            }
-            __m.__matches_.assign(__m.size(), __m.__unmatched_);
-        }
-    }
-    __m.__matches_.clear();
-    return false;
-}
-
-template <class _BidirectionalIterator, class _Allocator, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_search(_BidirectionalIterator __first, _BidirectionalIterator __last,
-             match_results<_BidirectionalIterator, _Allocator>& __m,
-             const basic_regex<_CharT, _Traits>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    int __offset = (__flags & regex_constants::match_prev_avail) ? 1 : 0;
-    basic_string<_CharT> __s(_VSTD::prev(__first, __offset), __last);
-    match_results<const _CharT*> __mc;
-    bool __r = __e.__search(__s.data() + __offset, __s.data() + __s.size(), __mc, __flags);
-    __m.__assign(__first, __last, __mc, __flags & regex_constants::__no_update_pos);
-    return __r;
-}
-
-template <class _Iter, class _Allocator, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_search(__wrap_iter<_Iter> __first,
-             __wrap_iter<_Iter> __last,
-             match_results<__wrap_iter<_Iter>, _Allocator>& __m,
-             const basic_regex<_CharT, _Traits>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    match_results<const _CharT*> __mc;
-    bool __r = __e.__search(__first.base(), __last.base(), __mc, __flags);
-    __m.__assign(__first, __last, __mc, __flags & regex_constants::__no_update_pos);
-    return __r;
-}
-
-template <class _Allocator, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_search(const _CharT* __first, const _CharT* __last,
-             match_results<const _CharT*, _Allocator>& __m,
-             const basic_regex<_CharT, _Traits>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    return __e.__search(__first, __last, __m, __flags);
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_search(_BidirectionalIterator __first, _BidirectionalIterator __last,
-             const basic_regex<_CharT, _Traits>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    basic_string<_CharT> __s(__first, __last);
-    match_results<const _CharT*> __mc;
-    return __e.__search(__s.data(), __s.data() + __s.size(), __mc, __flags);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_search(const _CharT* __first, const _CharT* __last,
-             const basic_regex<_CharT, _Traits>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    match_results<const _CharT*> __mc;
-    return __e.__search(__first, __last, __mc, __flags);
-}
-
-template <class _CharT, class _Allocator, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_search(const _CharT* __str, match_results<const _CharT*, _Allocator>& __m,
-             const basic_regex<_CharT, _Traits>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    return __e.__search(__str, __str + _Traits::length(__str), __m, __flags);
-}
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_search(const _CharT* __str, const basic_regex<_CharT, _Traits>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    match_results<const _CharT*> __m;
-    return _VSTD::regex_search(__str, __m, __e, __flags);
-}
-
-template <class _ST, class _SA, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_search(const basic_string<_CharT, _ST, _SA>& __s,
-             const basic_regex<_CharT, _Traits>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    match_results<const _CharT*> __mc;
-    return __e.__search(__s.data(), __s.data() + __s.size(), __mc, __flags);
-}
-
-template <class _ST, class _SA, class _Allocator, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_search(const basic_string<_CharT, _ST, _SA>& __s,
-             match_results<typename basic_string<_CharT, _ST, _SA>::const_iterator, _Allocator>& __m,
-             const basic_regex<_CharT, _Traits>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    match_results<const _CharT*> __mc;
-    bool __r = __e.__search(__s.data(), __s.data() + __s.size(), __mc, __flags);
-    __m.__assign(__s.begin(), __s.end(), __mc, __flags & regex_constants::__no_update_pos);
-    return __r;
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _ST, class _SA, class _Ap, class _Cp, class _Tp>
-bool
-regex_search(const basic_string<_Cp, _ST, _SA>&& __s,
-             match_results<typename basic_string<_Cp, _ST, _SA>::const_iterator, _Ap>&,
-             const basic_regex<_Cp, _Tp>& __e,
-             regex_constants::match_flag_type __flags = regex_constants::match_default) = delete; 
-#endif
-
-// regex_match
-
-template <class _BidirectionalIterator, class _Allocator, class _CharT, class _Traits>
-bool
-regex_match(_BidirectionalIterator __first, _BidirectionalIterator __last,
-            match_results<_BidirectionalIterator, _Allocator>& __m,
-            const basic_regex<_CharT, _Traits>& __e,
-            regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    bool __r = _VSTD::regex_search(
-        __first, __last, __m, __e,
-        __flags | regex_constants::match_continuous |
-        regex_constants::__full_match);
-    if (__r)
-    {
-        __r = !__m.suffix().matched;
-        if (!__r)
-            __m.__matches_.clear();
-    }
-    return __r;
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_match(_BidirectionalIterator __first, _BidirectionalIterator __last,
-            const basic_regex<_CharT, _Traits>& __e,
-            regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    match_results<_BidirectionalIterator> __m;
-    return _VSTD::regex_match(__first, __last, __m, __e, __flags);
-}
-
-template <class _CharT, class _Allocator, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_match(const _CharT* __str, match_results<const _CharT*, _Allocator>& __m,
-            const basic_regex<_CharT, _Traits>& __e,
-            regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    return _VSTD::regex_match(__str, __str + _Traits::length(__str), __m, __e, __flags);
-}
-
-template <class _ST, class _SA, class _Allocator, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_match(const basic_string<_CharT, _ST, _SA>& __s,
-            match_results<typename basic_string<_CharT, _ST, _SA>::const_iterator, _Allocator>& __m,
-            const basic_regex<_CharT, _Traits>& __e,
-            regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    return _VSTD::regex_match(__s.begin(), __s.end(), __m, __e, __flags);
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _ST, class _SA, class _Allocator, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_match(const basic_string<_CharT, _ST, _SA>&& __s,
-            match_results<typename basic_string<_CharT, _ST, _SA>::const_iterator, _Allocator>& __m,
-            const basic_regex<_CharT, _Traits>& __e,
-            regex_constants::match_flag_type __flags = regex_constants::match_default) = delete; 
-#endif
-
-template <class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_match(const _CharT* __str, const basic_regex<_CharT, _Traits>& __e,
-            regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    return _VSTD::regex_match(__str, __str + _Traits::length(__str), __e, __flags);
-}
-
-template <class _ST, class _SA, class _CharT, class _Traits>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-regex_match(const basic_string<_CharT, _ST, _SA>& __s,
-            const basic_regex<_CharT, _Traits>& __e,
-            regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    return _VSTD::regex_match(__s.begin(), __s.end(), __e, __flags);
-}
-
-// regex_iterator
-
-template <class _BidirectionalIterator,
-          class _CharT = typename iterator_traits<_BidirectionalIterator>::value_type,
-          class _Traits = regex_traits<_CharT> >
-class _LIBCPP_TEMPLATE_VIS regex_iterator
-{
-public:
-    typedef basic_regex<_CharT, _Traits>          regex_type;
-    typedef match_results<_BidirectionalIterator> value_type;
-    typedef ptrdiff_t                             difference_type;
-    typedef const value_type*                     pointer;
-    typedef const value_type&                     reference;
-    typedef forward_iterator_tag                  iterator_category;
-
-private:
-    _BidirectionalIterator           __begin_;
-    _BidirectionalIterator           __end_;
-    const regex_type*                __pregex_;
-    regex_constants::match_flag_type __flags_;
-    value_type                       __match_;
-
-public:
-    regex_iterator();
-    regex_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                   const regex_type& __re,
-                   regex_constants::match_flag_type __m
-                                              = regex_constants::match_default);
-#if _LIBCPP_STD_VER > 11
-    regex_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                   const regex_type&& __re,
-                   regex_constants::match_flag_type __m 
-                                     = regex_constants::match_default) = delete;
-#endif
-
-    bool operator==(const regex_iterator& __x) const;
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const regex_iterator& __x) const {return !(*this == __x);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {return  __match_;}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const  {return &__match_;}
-
-    regex_iterator& operator++();
-    _LIBCPP_INLINE_VISIBILITY
-    regex_iterator operator++(int)
-    {
-        regex_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-};
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_iterator<_BidirectionalIterator, _CharT, _Traits>::regex_iterator()
-    : __begin_(), __end_(), __pregex_(nullptr), __flags_(), __match_()
-{
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    regex_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                   const regex_type& __re, regex_constants::match_flag_type __m)
-    : __begin_(__a),
-      __end_(__b),
-      __pregex_(&__re),
-      __flags_(__m)
-{
-    _VSTD::regex_search(__begin_, __end_, __match_, *__pregex_, __flags_);
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-bool
-regex_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    operator==(const regex_iterator& __x) const
-{
-    if (__match_.empty() && __x.__match_.empty())
-        return true;
-    if (__match_.empty() || __x.__match_.empty())
-        return false;
-    return __begin_ == __x.__begin_       &&
-           __end_ == __x.__end_           &&
-           __pregex_ == __x.__pregex_     &&
-           __flags_ == __x.__flags_       &&
-           __match_[0] == __x.__match_[0];
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_iterator<_BidirectionalIterator, _CharT, _Traits>&
-regex_iterator<_BidirectionalIterator, _CharT, _Traits>::operator++()
-{
-    __flags_ |= regex_constants::__no_update_pos;
-    _BidirectionalIterator __start = __match_[0].second;
-    if (__match_[0].first == __match_[0].second)
-    {
-        if (__start == __end_)
-        {
-            __match_ = value_type();
-            return *this;
-        }
-        else if (_VSTD::regex_search(__start, __end_, __match_, *__pregex_,
-                                    __flags_ | regex_constants::match_not_null |
-                                    regex_constants::match_continuous))
-            return *this;
-        else
-            ++__start;
-    }
-    __flags_ |= regex_constants::match_prev_avail;
-    if (!_VSTD::regex_search(__start, __end_, __match_, *__pregex_, __flags_))
-        __match_ = value_type();
-    return *this;
-}
-
-typedef regex_iterator<const char*>             cregex_iterator;
-typedef regex_iterator<const wchar_t*>          wcregex_iterator;
-typedef regex_iterator<string::const_iterator>  sregex_iterator;
-typedef regex_iterator<wstring::const_iterator> wsregex_iterator;
-
-// regex_token_iterator
-
-template <class _BidirectionalIterator,
-          class _CharT = typename iterator_traits<_BidirectionalIterator>::value_type,
-          class _Traits = regex_traits<_CharT> >
-class _LIBCPP_TEMPLATE_VIS regex_token_iterator
-{
-public:
-    typedef basic_regex<_CharT, _Traits>      regex_type;
-    typedef sub_match<_BidirectionalIterator> value_type;
-    typedef ptrdiff_t                         difference_type;
-    typedef const value_type*                 pointer;
-    typedef const value_type&                 reference;
-    typedef forward_iterator_tag              iterator_category;
-
-private:
-    typedef regex_iterator<_BidirectionalIterator, _CharT, _Traits> _Position;
-
-    _Position         __position_;
-    const value_type* __result_;
-    value_type        __suffix_;
-    ptrdiff_t         __n_;
-    vector<int>       __subs_;
-
-public:
-    regex_token_iterator();
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                         const regex_type& __re, int __submatch = 0,
-                         regex_constants::match_flag_type __m =
-                                                regex_constants::match_default);
-#if _LIBCPP_STD_VER > 11
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                         const regex_type&& __re, int __submatch = 0,
-                         regex_constants::match_flag_type __m =
-                                       regex_constants::match_default) = delete;
-#endif
-
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                         const regex_type& __re, const vector<int>& __submatches,
-                         regex_constants::match_flag_type __m =
-                                                regex_constants::match_default);
-#if _LIBCPP_STD_VER > 11
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                         const regex_type&& __re, const vector<int>& __submatches,
-                         regex_constants::match_flag_type __m =
-                                     regex_constants::match_default) = delete;
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                         const regex_type& __re,
-                         initializer_list<int> __submatches,
-                         regex_constants::match_flag_type __m =
-                                                regex_constants::match_default);
-
-#if _LIBCPP_STD_VER > 11
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                         const regex_type&& __re,
-                         initializer_list<int> __submatches,
-                         regex_constants::match_flag_type __m =
-                                       regex_constants::match_default) = delete;
-#endif
-#endif  // _LIBCPP_CXX03_LANG
-    template <size_t _Np>
-        regex_token_iterator(_BidirectionalIterator __a,
-                             _BidirectionalIterator __b,
-                             const regex_type& __re,
-                             const int (&__submatches)[_Np],
-                             regex_constants::match_flag_type __m =
-                                                regex_constants::match_default);
-#if _LIBCPP_STD_VER > 11
-    template <std::size_t _Np>
-        regex_token_iterator(_BidirectionalIterator __a,
-                             _BidirectionalIterator __b,
-                             const regex_type&& __re,
-                             const int (&__submatches)[_Np],
-                             regex_constants::match_flag_type __m =
-                                      regex_constants::match_default) = delete;
-#endif
-
-    regex_token_iterator(const regex_token_iterator&);
-    regex_token_iterator& operator=(const regex_token_iterator&);
-
-    bool operator==(const regex_token_iterator& __x) const;
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const regex_token_iterator& __x) const {return !(*this == __x);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type& operator*() const {return *__result_;}
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type* operator->() const {return __result_;}
-
-    regex_token_iterator& operator++();
-    _LIBCPP_INLINE_VISIBILITY
-    regex_token_iterator operator++(int)
-    {
-        regex_token_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-private:
-    void __init(_BidirectionalIterator __a, _BidirectionalIterator __b);
-    void __establish_result () {
-        if (__subs_[__n_] == -1)
-            __result_ = &__position_->prefix();
-        else
-            __result_ = &(*__position_)[__subs_[__n_]];
-        }       
-};
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    regex_token_iterator()
-    : __result_(nullptr),
-      __suffix_(),
-      __n_(0)
-{
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-void
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    __init(_BidirectionalIterator __a, _BidirectionalIterator __b)
-{
-    if (__position_ != _Position())
-        __establish_result ();
-    else if (__subs_[__n_] == -1)
-    {
-        __suffix_.matched = true;
-        __suffix_.first = __a;
-        __suffix_.second = __b;
-        __result_ = &__suffix_;
-    }
-    else
-        __result_ = nullptr;
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                         const regex_type& __re, int __submatch,
-                         regex_constants::match_flag_type __m)
-    : __position_(__a, __b, __re, __m),
-      __n_(0),
-      __subs_(1, __submatch)
-{
-    __init(__a, __b);
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                         const regex_type& __re, const vector<int>& __submatches,
-                         regex_constants::match_flag_type __m)
-    : __position_(__a, __b, __re, __m),
-      __n_(0),
-      __subs_(__submatches)
-{
-    __init(__a, __b);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                         const regex_type& __re,
-                         initializer_list<int> __submatches,
-                         regex_constants::match_flag_type __m)
-    : __position_(__a, __b, __re, __m),
-      __n_(0),
-      __subs_(__submatches)
-{
-    __init(__a, __b);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-template <size_t _Np>
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    regex_token_iterator(_BidirectionalIterator __a, _BidirectionalIterator __b,
-                             const regex_type& __re,
-                             const int (&__submatches)[_Np],
-                             regex_constants::match_flag_type __m)
-    : __position_(__a, __b, __re, __m),
-      __n_(0),
-      __subs_(__submatches, __submatches + _Np)
-{
-    __init(__a, __b);
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    regex_token_iterator(const regex_token_iterator& __x)
-    : __position_(__x.__position_),
-      __result_(__x.__result_),
-      __suffix_(__x.__suffix_),
-      __n_(__x.__n_),
-      __subs_(__x.__subs_)
-{
-    if (__x.__result_ == &__x.__suffix_)
-        __result_ = &__suffix_;
-    else if ( __result_ != nullptr )
-        __establish_result ();
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>&
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    operator=(const regex_token_iterator& __x)
-{
-    if (this != &__x)
-    {
-        __position_ = __x.__position_;
-        if (__x.__result_ == &__x.__suffix_)
-            __result_ = &__suffix_;
-        else
-            __result_ = __x.__result_;
-        __suffix_ = __x.__suffix_;
-        __n_ = __x.__n_;
-        __subs_ = __x.__subs_;
-
-        if ( __result_ != nullptr && __result_ != &__suffix_ )
-            __establish_result();
-    }
-    return *this;
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-bool
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::
-    operator==(const regex_token_iterator& __x) const
-{
-    if (__result_ == nullptr && __x.__result_ == nullptr)
-        return true;
-    if (__result_ == &__suffix_ && __x.__result_ == &__x.__suffix_ &&
-            __suffix_ == __x.__suffix_)
-        return true;
-    if (__result_ == nullptr || __x.__result_ == nullptr)
-        return false;
-    if (__result_ == &__suffix_ || __x.__result_ == &__x.__suffix_)
-        return false;
-    return __position_ == __x.__position_ && __n_ == __x.__n_ &&
-           __subs_ == __x.__subs_;
-}
-
-template <class _BidirectionalIterator, class _CharT, class _Traits>
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>&
-regex_token_iterator<_BidirectionalIterator, _CharT, _Traits>::operator++()
-{
-    _Position __prev = __position_;
-    if (__result_ == &__suffix_)
-        __result_ = nullptr;
-    else if (static_cast<size_t>(__n_ + 1) < __subs_.size())
-    {
-        ++__n_;
-        __establish_result();
-    }
-    else
-    {
-        __n_ = 0;
-        ++__position_;
-        if (__position_ != _Position())
-            __establish_result();
-        else
-        {
-            if (_VSTD::find(__subs_.begin(), __subs_.end(), -1) != __subs_.end()
-                && __prev->suffix().length() != 0)
-            {
-                __suffix_.matched = true;
-                __suffix_.first = __prev->suffix().first;
-                __suffix_.second = __prev->suffix().second;
-                __result_ = &__suffix_;
-            }
-            else
-                __result_ = nullptr;
-        }
-    }
-    return *this;
-}
-
-typedef regex_token_iterator<const char*>             cregex_token_iterator;
-typedef regex_token_iterator<const wchar_t*>          wcregex_token_iterator;
-typedef regex_token_iterator<string::const_iterator>  sregex_token_iterator;
-typedef regex_token_iterator<wstring::const_iterator> wsregex_token_iterator;
-
-// regex_replace
-
-template <class _OutputIterator, class _BidirectionalIterator,
-          class _Traits, class _CharT>
-_OutputIterator
-regex_replace(_OutputIterator __output_iter,
-              _BidirectionalIterator __first, _BidirectionalIterator __last,
-              const basic_regex<_CharT, _Traits>& __e, const _CharT* __fmt,
-              regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    typedef regex_iterator<_BidirectionalIterator, _CharT, _Traits> _Iter;
-    _Iter __i(__first, __last, __e, __flags);
-    _Iter __eof;
-    if (__i == __eof)
-    {
-        if (!(__flags & regex_constants::format_no_copy))
-            __output_iter = _VSTD::copy(__first, __last, __output_iter);
-    }
-    else
-    {
-        sub_match<_BidirectionalIterator> __lm;
-        for (size_t __len = char_traits<_CharT>::length(__fmt); __i != __eof; ++__i)
-        {
-            if (!(__flags & regex_constants::format_no_copy))
-                __output_iter = _VSTD::copy(__i->prefix().first, __i->prefix().second, __output_iter);
-            __output_iter = __i->format(__output_iter, __fmt, __fmt + __len, __flags);
-            __lm = __i->suffix();
-            if (__flags & regex_constants::format_first_only)
-                break;
-        }
-        if (!(__flags & regex_constants::format_no_copy))
-            __output_iter = _VSTD::copy(__lm.first, __lm.second, __output_iter);
-    }
-    return __output_iter;
-}
-
-template <class _OutputIterator, class _BidirectionalIterator,
-          class _Traits, class _CharT, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-_OutputIterator
-regex_replace(_OutputIterator __output_iter,
-              _BidirectionalIterator __first, _BidirectionalIterator __last,
-              const basic_regex<_CharT, _Traits>& __e,
-              const basic_string<_CharT, _ST, _SA>& __fmt,
-              regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    return _VSTD::regex_replace(__output_iter, __first, __last, __e, __fmt.c_str(), __flags);
-}
-
-template <class _Traits, class _CharT, class _ST, class _SA, class _FST,
-          class _FSA>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _ST, _SA>
-regex_replace(const basic_string<_CharT, _ST, _SA>& __s,
-              const basic_regex<_CharT, _Traits>& __e,
-              const basic_string<_CharT, _FST, _FSA>& __fmt,
-              regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    basic_string<_CharT, _ST, _SA> __r;
-    _VSTD::regex_replace(back_inserter(__r), __s.begin(), __s.end(), __e,
-                        __fmt.c_str(), __flags);
-    return __r;
-}
-
-template <class _Traits, class _CharT, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _ST, _SA>
-regex_replace(const basic_string<_CharT, _ST, _SA>& __s,
-              const basic_regex<_CharT, _Traits>& __e, const _CharT* __fmt,
-              regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    basic_string<_CharT, _ST, _SA> __r;
-    _VSTD::regex_replace(back_inserter(__r), __s.begin(), __s.end(), __e,
-                        __fmt, __flags);
-    return __r;
-}
-
-template <class _Traits, class _CharT, class _ST, class _SA>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT>
-regex_replace(const _CharT* __s,
-              const basic_regex<_CharT, _Traits>& __e,
-              const basic_string<_CharT, _ST, _SA>& __fmt,
-              regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    basic_string<_CharT> __r;
-    _VSTD::regex_replace(back_inserter(__r), __s,
-                        __s + char_traits<_CharT>::length(__s), __e,
-                        __fmt.c_str(), __flags);
-    return __r;
-}
-
-template <class _Traits, class _CharT>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT>
-regex_replace(const _CharT* __s,
-              const basic_regex<_CharT, _Traits>& __e,
-              const _CharT* __fmt,
-              regex_constants::match_flag_type __flags = regex_constants::match_default)
-{
-    basic_string<_CharT> __r;
-    _VSTD::regex_replace(back_inserter(__r), __s,
-                        __s + char_traits<_CharT>::length(__s), __e,
-                        __fmt, __flags);
-    return __r;
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_REGEX
diff --git a/lib/libcxx/include/scoped_allocator b/lib/libcxx/include/scoped_allocator
deleted file mode 100644
index bdbb0136b5c..00000000000
--- a/lib/libcxx/include/scoped_allocator
+++ /dev/null
@@ -1,684 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- scoped_allocator --------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SCOPED_ALLOCATOR
-#define _LIBCPP_SCOPED_ALLOCATOR
-
-/*
-    scoped_allocator synopsis
-
-namespace std
-{
-
-template <class OuterAlloc, class... InnerAllocs>
-class scoped_allocator_adaptor : public OuterAlloc
-{
-    typedef allocator_traits<OuterAlloc> OuterTraits; // exposition only
-    scoped_allocator_adaptor<InnerAllocs...> inner;   // exposition only
-public:
-
-    typedef OuterAlloc outer_allocator_type;
-    typedef see below inner_allocator_type;
-
-    typedef typename OuterTraits::value_type value_type;
-    typedef typename OuterTraits::size_type size_type;
-    typedef typename OuterTraits::difference_type difference_type;
-    typedef typename OuterTraits::pointer pointer;
-    typedef typename OuterTraits::const_pointer const_pointer;
-    typedef typename OuterTraits::void_pointer void_pointer;
-    typedef typename OuterTraits::const_void_pointer const_void_pointer;
-
-    typedef see below propagate_on_container_copy_assignment;
-    typedef see below propagate_on_container_move_assignment;
-    typedef see below propagate_on_container_swap;
-    typedef see below is_always_equal;
-
-    template <class Tp>
-        struct rebind
-        {
-            typedef scoped_allocator_adaptor<
-                OuterTraits::template rebind_alloc<Tp>, InnerAllocs...> other;
-        };
-
-    scoped_allocator_adaptor();
-    template <class OuterA2>
-        scoped_allocator_adaptor(OuterA2&& outerAlloc,
-                                 const InnerAllocs&... innerAllocs) noexcept;
-    scoped_allocator_adaptor(const scoped_allocator_adaptor& other) noexcept;
-    scoped_allocator_adaptor(scoped_allocator_adaptor&& other) noexcept;
-    template <class OuterA2>
-        scoped_allocator_adaptor(const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& other) noexcept;
-    template <class OuterA2>
-        scoped_allocator_adaptor(const scoped_allocator_adaptor<OuterA2, InnerAllocs...>&& other) noexcept;
-
-    scoped_allocator_adaptor& operator=(const scoped_allocator_adaptor&) = default;
-    scoped_allocator_adaptor& operator=(scoped_allocator_adaptor&&) = default;
-    ~scoped_allocator_adaptor();
-
-    inner_allocator_type& inner_allocator() noexcept;
-    const inner_allocator_type& inner_allocator() const noexcept;
-
-    outer_allocator_type& outer_allocator() noexcept;
-    const outer_allocator_type& outer_allocator() const noexcept;
-
-    pointer allocate(size_type n);                           // [[nodiscard]] in C++20
-    pointer allocate(size_type n, const_void_pointer hint);  // [[nodiscard]] in C++20
-    void deallocate(pointer p, size_type n) noexcept;
-
-    size_type max_size() const;
-    template <class T, class... Args> void construct(T* p, Args&& args);
-    template <class T1, class T2, class... Args1, class... Args2>
-        void construct(pair<T1, T2>* p, piecewise_construct t, tuple<Args1...> x,
-                       tuple<Args2...> y);
-    template <class T1, class T2>
-        void construct(pair<T1, T2>* p);
-    template <class T1, class T2, class U, class V>
-        void construct(pair<T1, T2>* p, U&& x, V&& y);
-    template <class T1, class T2, class U, class V>
-        void construct(pair<T1, T2>* p, const pair<U, V>& x);
-    template <class T1, class T2, class U, class V>
-        void construct(pair<T1, T2>* p, pair<U, V>&& x);
-    template <class T> void destroy(T* p);
-
-    template <class T> void destroy(T* p) noexcept;
-
-    scoped_allocator_adaptor select_on_container_copy_construction() const noexcept;
-};
-
-template <class OuterA1, class OuterA2, class... InnerAllocs>
-    bool
-    operator==(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a,
-               const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b) noexcept;
-
-template <class OuterA1, class OuterA2, class... InnerAllocs>
-    bool
-    operator!=(const scoped_allocator_adaptor<OuterA1, InnerAllocs...>& a,
-               const scoped_allocator_adaptor<OuterA2, InnerAllocs...>& b) noexcept;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <memory>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if !defined(_LIBCPP_CXX03_LANG)
-
-// scoped_allocator_adaptor
-
-template <class ..._Allocs>
-class scoped_allocator_adaptor;
-
-template <class ..._Allocs> struct __get_poc_copy_assignment;
-
-template <class _A0>
-struct __get_poc_copy_assignment<_A0>
-{
-    static const bool value = allocator_traits<_A0>::
-                              propagate_on_container_copy_assignment::value;
-};
-
-template <class _A0, class ..._Allocs>
-struct __get_poc_copy_assignment<_A0, _Allocs...>
-{
-    static const bool value =
-        allocator_traits<_A0>::propagate_on_container_copy_assignment::value ||
-        __get_poc_copy_assignment<_Allocs...>::value;
-};
-
-template <class ..._Allocs> struct __get_poc_move_assignment;
-
-template <class _A0>
-struct __get_poc_move_assignment<_A0>
-{
-    static const bool value = allocator_traits<_A0>::
-                              propagate_on_container_move_assignment::value;
-};
-
-template <class _A0, class ..._Allocs>
-struct __get_poc_move_assignment<_A0, _Allocs...>
-{
-    static const bool value =
-        allocator_traits<_A0>::propagate_on_container_move_assignment::value ||
-        __get_poc_move_assignment<_Allocs...>::value;
-};
-
-template <class ..._Allocs> struct __get_poc_swap;
-
-template <class _A0>
-struct __get_poc_swap<_A0>
-{
-    static const bool value = allocator_traits<_A0>::
-                              propagate_on_container_swap::value;
-};
-
-template <class _A0, class ..._Allocs>
-struct __get_poc_swap<_A0, _Allocs...>
-{
-    static const bool value =
-        allocator_traits<_A0>::propagate_on_container_swap::value ||
-        __get_poc_swap<_Allocs...>::value;
-};
-
-template <class ..._Allocs> struct __get_is_always_equal;
-
-template <class _A0>
-struct __get_is_always_equal<_A0>
-{
-    static const bool value = allocator_traits<_A0>::is_always_equal::value;
-};
-
-template <class _A0, class ..._Allocs>
-struct __get_is_always_equal<_A0, _Allocs...>
-{
-    static const bool value =
-        allocator_traits<_A0>::is_always_equal::value &&
-        __get_is_always_equal<_Allocs...>::value;
-};
-
-template <class ..._Allocs>
-class __scoped_allocator_storage;
-
-template <class _OuterAlloc, class... _InnerAllocs>
-class __scoped_allocator_storage<_OuterAlloc, _InnerAllocs...>
-    : public _OuterAlloc
-{
-    typedef _OuterAlloc outer_allocator_type;
-protected:
-    typedef scoped_allocator_adaptor<_InnerAllocs...> inner_allocator_type;
-
-private:
-    inner_allocator_type __inner_;
-
-protected:
-
-    _LIBCPP_INLINE_VISIBILITY
-    __scoped_allocator_storage() _NOEXCEPT {}
-
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, _OuterA2>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        __scoped_allocator_storage(_OuterA2&& __outerAlloc,
-                                   const _InnerAllocs& ...__innerAllocs) _NOEXCEPT
-            : outer_allocator_type(_VSTD::forward<_OuterA2>(__outerAlloc)),
-              __inner_(__innerAllocs...) {}
-
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, const _OuterA2&>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        __scoped_allocator_storage(
-            const __scoped_allocator_storage<_OuterA2, _InnerAllocs...>& __other) _NOEXCEPT
-            : outer_allocator_type(__other.outer_allocator()),
-              __inner_(__other.inner_allocator()) {}
-
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, _OuterA2>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        __scoped_allocator_storage(
-            __scoped_allocator_storage<_OuterA2, _InnerAllocs...>&& __other) _NOEXCEPT
-            : outer_allocator_type(_VSTD::move(__other.outer_allocator())),
-              __inner_(_VSTD::move(__other.inner_allocator())) {}
-
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, _OuterA2>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        __scoped_allocator_storage(_OuterA2&& __o,
-                                   const inner_allocator_type& __i) _NOEXCEPT
-            : outer_allocator_type(_VSTD::forward<_OuterA2>(__o)),
-              __inner_(__i)
-        {
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    inner_allocator_type& inner_allocator() _NOEXCEPT             {return __inner_;}
-    _LIBCPP_INLINE_VISIBILITY
-    const inner_allocator_type& inner_allocator() const _NOEXCEPT {return __inner_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    outer_allocator_type& outer_allocator() _NOEXCEPT
-        {return static_cast<outer_allocator_type&>(*this);}
-    _LIBCPP_INLINE_VISIBILITY
-    const outer_allocator_type& outer_allocator() const _NOEXCEPT
-        {return static_cast<const outer_allocator_type&>(*this);}
-
-    scoped_allocator_adaptor<outer_allocator_type, _InnerAllocs...>
-    _LIBCPP_INLINE_VISIBILITY
-    select_on_container_copy_construction() const _NOEXCEPT
-        {
-            return scoped_allocator_adaptor<outer_allocator_type, _InnerAllocs...>
-            (
-                allocator_traits<outer_allocator_type>::
-                    select_on_container_copy_construction(outer_allocator()),
-                allocator_traits<inner_allocator_type>::
-                    select_on_container_copy_construction(inner_allocator())
-            );
-        }
-
-    template <class...> friend class __scoped_allocator_storage;
-};
-
-template <class _OuterAlloc>
-class __scoped_allocator_storage<_OuterAlloc>
-    : public _OuterAlloc
-{
-    typedef _OuterAlloc outer_allocator_type;
-protected:
-    typedef scoped_allocator_adaptor<_OuterAlloc> inner_allocator_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __scoped_allocator_storage() _NOEXCEPT {}
-
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, _OuterA2>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        __scoped_allocator_storage(_OuterA2&& __outerAlloc) _NOEXCEPT
-            : outer_allocator_type(_VSTD::forward<_OuterA2>(__outerAlloc)) {}
-
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, const _OuterA2&>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        __scoped_allocator_storage(
-            const __scoped_allocator_storage<_OuterA2>& __other) _NOEXCEPT
-            : outer_allocator_type(__other.outer_allocator()) {}
-
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, _OuterA2>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        __scoped_allocator_storage(
-            __scoped_allocator_storage<_OuterA2>&& __other) _NOEXCEPT
-            : outer_allocator_type(_VSTD::move(__other.outer_allocator())) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    inner_allocator_type& inner_allocator() _NOEXCEPT
-        {return static_cast<inner_allocator_type&>(*this);}
-    _LIBCPP_INLINE_VISIBILITY
-    const inner_allocator_type& inner_allocator() const _NOEXCEPT
-        {return static_cast<const inner_allocator_type&>(*this);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    outer_allocator_type& outer_allocator() _NOEXCEPT
-        {return static_cast<outer_allocator_type&>(*this);}
-    _LIBCPP_INLINE_VISIBILITY
-    const outer_allocator_type& outer_allocator() const _NOEXCEPT
-        {return static_cast<const outer_allocator_type&>(*this);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    scoped_allocator_adaptor<outer_allocator_type>
-    select_on_container_copy_construction() const _NOEXCEPT
-        {return scoped_allocator_adaptor<outer_allocator_type>(
-            allocator_traits<outer_allocator_type>::
-                select_on_container_copy_construction(outer_allocator())
-        );}
-
-    __scoped_allocator_storage(const outer_allocator_type& __o,
-                               const inner_allocator_type& __i) _NOEXCEPT;
-
-    template <class...> friend class __scoped_allocator_storage;
-};
-
-// __outermost
-
-template <class _Alloc>
-decltype(declval<_Alloc>().outer_allocator(), true_type())
-__has_outer_allocator_test(_Alloc&& __a);
-
-template <class _Alloc>
-false_type
-__has_outer_allocator_test(const volatile _Alloc& __a);
-
-template <class _Alloc>
-struct __has_outer_allocator
-    : public common_type
-             <
-                 decltype(__has_outer_allocator_test(declval<_Alloc&>()))
-             >::type
-{
-};
-
-template <class _Alloc, bool = __has_outer_allocator<_Alloc>::value>
-struct __outermost
-{
-    typedef _Alloc type;
-    _LIBCPP_INLINE_VISIBILITY
-    type& operator()(type& __a) const _NOEXCEPT {return __a;}
-};
-
-template <class _Alloc>
-struct __outermost<_Alloc, true>
-{
-    typedef typename remove_reference
-                     <
-                        decltype(_VSTD::declval<_Alloc>().outer_allocator())
-                     >::type                                    _OuterAlloc;
-    typedef typename __outermost<_OuterAlloc>::type             type;
-    _LIBCPP_INLINE_VISIBILITY
-    type& operator()(_Alloc& __a) const _NOEXCEPT
-        {return __outermost<_OuterAlloc>()(__a.outer_allocator());}
-};
-
-template <class _OuterAlloc, class... _InnerAllocs>
-class _LIBCPP_TEMPLATE_VIS scoped_allocator_adaptor<_OuterAlloc, _InnerAllocs...>
-    : public __scoped_allocator_storage<_OuterAlloc, _InnerAllocs...>
-{
-    typedef __scoped_allocator_storage<_OuterAlloc, _InnerAllocs...> base;
-    typedef allocator_traits<_OuterAlloc>             _OuterTraits;
-public:
-    typedef _OuterAlloc                               outer_allocator_type;
-    typedef typename base::inner_allocator_type       inner_allocator_type;
-    typedef typename _OuterTraits::size_type          size_type;
-    typedef typename _OuterTraits::difference_type    difference_type;
-    typedef typename _OuterTraits::pointer            pointer;
-    typedef typename _OuterTraits::const_pointer      const_pointer;
-    typedef typename _OuterTraits::void_pointer       void_pointer;
-    typedef typename _OuterTraits::const_void_pointer const_void_pointer;
-
-    typedef integral_constant
-            <
-                bool,
-                __get_poc_copy_assignment<outer_allocator_type,
-                                          _InnerAllocs...>::value
-            > propagate_on_container_copy_assignment;
-    typedef integral_constant
-            <
-                bool,
-                __get_poc_move_assignment<outer_allocator_type,
-                                          _InnerAllocs...>::value
-            > propagate_on_container_move_assignment;
-    typedef integral_constant
-            <
-                bool,
-                __get_poc_swap<outer_allocator_type, _InnerAllocs...>::value
-            > propagate_on_container_swap;
-    typedef integral_constant
-            <
-                bool,
-                __get_is_always_equal<outer_allocator_type, _InnerAllocs...>::value
-            > is_always_equal;
-
-    template <class _Tp>
-    struct rebind
-    {
-        typedef scoped_allocator_adaptor
-        <
-            typename _OuterTraits::template rebind_alloc<_Tp>, _InnerAllocs...
-        > other;
-    };
-
-    _LIBCPP_INLINE_VISIBILITY
-    scoped_allocator_adaptor() _NOEXCEPT {}
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, _OuterA2>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        scoped_allocator_adaptor(_OuterA2&& __outerAlloc,
-                                 const _InnerAllocs& ...__innerAllocs) _NOEXCEPT
-            : base(_VSTD::forward<_OuterA2>(__outerAlloc), __innerAllocs...) {}
-    // scoped_allocator_adaptor(const scoped_allocator_adaptor& __other) = default;
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, const _OuterA2&>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        scoped_allocator_adaptor(
-            const scoped_allocator_adaptor<_OuterA2, _InnerAllocs...>& __other) _NOEXCEPT
-                : base(__other) {}
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, _OuterA2>::value
-                      >::type>
-        _LIBCPP_INLINE_VISIBILITY
-        scoped_allocator_adaptor(
-            scoped_allocator_adaptor<_OuterA2, _InnerAllocs...>&& __other) _NOEXCEPT
-                : base(_VSTD::move(__other)) {}
-
-    // scoped_allocator_adaptor& operator=(const scoped_allocator_adaptor&) = default;
-    // scoped_allocator_adaptor& operator=(scoped_allocator_adaptor&&) = default;
-    // ~scoped_allocator_adaptor() = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    inner_allocator_type& inner_allocator() _NOEXCEPT
-        {return base::inner_allocator();}
-    _LIBCPP_INLINE_VISIBILITY
-    const inner_allocator_type& inner_allocator() const _NOEXCEPT
-        {return base::inner_allocator();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    outer_allocator_type& outer_allocator() _NOEXCEPT
-        {return base::outer_allocator();}
-    _LIBCPP_INLINE_VISIBILITY
-    const outer_allocator_type& outer_allocator() const _NOEXCEPT
-        {return base::outer_allocator();}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    pointer allocate(size_type __n)
-        {return allocator_traits<outer_allocator_type>::
-            allocate(outer_allocator(), __n);}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    pointer allocate(size_type __n, const_void_pointer __hint)
-        {return allocator_traits<outer_allocator_type>::
-            allocate(outer_allocator(), __n, __hint);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void deallocate(pointer __p, size_type __n) _NOEXCEPT
-        {allocator_traits<outer_allocator_type>::
-            deallocate(outer_allocator(), __p, __n);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const
-        {return allocator_traits<outer_allocator_type>::max_size(outer_allocator());}
-
-    template <class _Tp, class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        void construct(_Tp* __p, _Args&& ...__args)
-            {__construct(__uses_alloc_ctor<_Tp, inner_allocator_type&, _Args...>(),
-                         __p, _VSTD::forward<_Args>(__args)...);}
-
-    template <class _T1, class _T2, class... _Args1, class... _Args2>
-    void construct(pair<_T1, _T2>* __p, piecewise_construct_t,
-                       tuple<_Args1...> __x, tuple<_Args2...> __y)
-    {
-        typedef __outermost<outer_allocator_type> _OM;
-        allocator_traits<typename _OM::type>::construct(
-            _OM()(outer_allocator()), __p, piecewise_construct
-          , __transform_tuple(
-              typename __uses_alloc_ctor<
-                  _T1, inner_allocator_type&, _Args1...
-              >::type()
-            , _VSTD::move(__x)
-            , typename __make_tuple_indices<sizeof...(_Args1)>::type{}
-          )
-          , __transform_tuple(
-              typename __uses_alloc_ctor<
-                  _T2, inner_allocator_type&, _Args2...
-              >::type()
-            , _VSTD::move(__y)
-            , typename __make_tuple_indices<sizeof...(_Args2)>::type{}
-          )
-        );
-    }
-
-    template <class _T1, class _T2>
-    void construct(pair<_T1, _T2>* __p)
-    { construct(__p, piecewise_construct, tuple<>{}, tuple<>{}); }
-
-    template <class _T1, class _T2, class _Up, class _Vp>
-    void construct(pair<_T1, _T2>* __p, _Up&& __x, _Vp&& __y) {
-        construct(__p, piecewise_construct,
-                  _VSTD::forward_as_tuple(_VSTD::forward<_Up>(__x)),
-                  _VSTD::forward_as_tuple(_VSTD::forward<_Vp>(__y)));
-    }
-
-    template <class _T1, class _T2, class _Up, class _Vp>
-    void construct(pair<_T1, _T2>* __p, const pair<_Up, _Vp>& __x) {
-        construct(__p, piecewise_construct,
-                  _VSTD::forward_as_tuple(__x.first),
-                  _VSTD::forward_as_tuple(__x.second));
-    }
-
-    template <class _T1, class _T2, class _Up, class _Vp>
-    void construct(pair<_T1, _T2>* __p, pair<_Up, _Vp>&& __x) {
-        construct(__p, piecewise_construct,
-                  _VSTD::forward_as_tuple(_VSTD::forward<_Up>(__x.first)),
-                  _VSTD::forward_as_tuple(_VSTD::forward<_Vp>(__x.second)));
-    }
-
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        void destroy(_Tp* __p)
-            {
-                typedef __outermost<outer_allocator_type> _OM;
-                allocator_traits<typename _OM::type>::
-                                         destroy(_OM()(outer_allocator()), __p);
-            }
-
-    _LIBCPP_INLINE_VISIBILITY
-    scoped_allocator_adaptor select_on_container_copy_construction() const _NOEXCEPT
-        {return base::select_on_container_copy_construction();}
-
-private:
-
-
-    template <class _OuterA2,
-              class = typename enable_if<
-                        is_constructible<outer_allocator_type, _OuterA2>::value
-                      >::type>
-    _LIBCPP_INLINE_VISIBILITY
-    scoped_allocator_adaptor(_OuterA2&& __o,
-                             const inner_allocator_type& __i) _NOEXCEPT
-        : base(_VSTD::forward<_OuterA2>(__o), __i) {}
-
-    template <class _Tp, class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        void __construct(integral_constant<int, 0>, _Tp* __p, _Args&& ...__args)
-            {
-                typedef __outermost<outer_allocator_type> _OM;
-                allocator_traits<typename _OM::type>::construct
-                (
-                    _OM()(outer_allocator()),
-                    __p,
-                    _VSTD::forward<_Args>(__args)...
-                );
-            }
-
-    template <class _Tp, class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        void __construct(integral_constant<int, 1>, _Tp* __p, _Args&& ...__args)
-            {
-                typedef __outermost<outer_allocator_type> _OM;
-                allocator_traits<typename _OM::type>::construct
-                (
-                    _OM()(outer_allocator()),
-                    __p, allocator_arg, inner_allocator(),
-                    _VSTD::forward<_Args>(__args)...
-                );
-            }
-
-    template <class _Tp, class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        void __construct(integral_constant<int, 2>, _Tp* __p, _Args&& ...__args)
-            {
-                typedef __outermost<outer_allocator_type> _OM;
-                allocator_traits<typename _OM::type>::construct
-                (
-                    _OM()(outer_allocator()),
-                    __p,
-                    _VSTD::forward<_Args>(__args)...,
-                    inner_allocator()
-                );
-            }
-
-    template <class ..._Args, size_t ..._Idx>
-    _LIBCPP_INLINE_VISIBILITY
-    tuple<_Args&&...>
-    __transform_tuple(integral_constant<int, 0>, tuple<_Args...>&& __t,
-                      __tuple_indices<_Idx...>)
-    {
-        return _VSTD::forward_as_tuple(_VSTD::get<_Idx>(_VSTD::move(__t))...);
-    }
-
-    template <class ..._Args, size_t ..._Idx>
-    _LIBCPP_INLINE_VISIBILITY
-    tuple<allocator_arg_t, inner_allocator_type&, _Args&&...>
-    __transform_tuple(integral_constant<int, 1>, tuple<_Args...> && __t,
-                      __tuple_indices<_Idx...>)
-    {
-        using _Tup = tuple<allocator_arg_t, inner_allocator_type&, _Args&&...>;
-        return _Tup(allocator_arg, inner_allocator(),
-                    _VSTD::get<_Idx>(_VSTD::move(__t))...);
-    }
-
-    template <class ..._Args, size_t ..._Idx>
-    _LIBCPP_INLINE_VISIBILITY
-    tuple<_Args&&..., inner_allocator_type&>
-    __transform_tuple(integral_constant<int, 2>, tuple<_Args...> && __t,
-                      __tuple_indices<_Idx...>)
-    {
-        using _Tup = tuple<_Args&&..., inner_allocator_type&>;
-        return _Tup(_VSTD::get<_Idx>(_VSTD::move(__t))..., inner_allocator());
-    }
-
-    template <class...> friend class __scoped_allocator_storage;
-};
-
-template <class _OuterA1, class _OuterA2>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const scoped_allocator_adaptor<_OuterA1>& __a,
-           const scoped_allocator_adaptor<_OuterA2>& __b) _NOEXCEPT
-{
-    return __a.outer_allocator() == __b.outer_allocator();
-}
-
-template <class _OuterA1, class _OuterA2, class _InnerA0, class... _InnerAllocs>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const scoped_allocator_adaptor<_OuterA1, _InnerA0, _InnerAllocs...>& __a,
-           const scoped_allocator_adaptor<_OuterA2, _InnerA0, _InnerAllocs...>& __b) _NOEXCEPT
-{
-    return __a.outer_allocator() == __b.outer_allocator() &&
-           __a.inner_allocator() == __b.inner_allocator();
-}
-
-template <class _OuterA1, class _OuterA2, class... _InnerAllocs>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const scoped_allocator_adaptor<_OuterA1, _InnerAllocs...>& __a,
-           const scoped_allocator_adaptor<_OuterA2, _InnerAllocs...>& __b) _NOEXCEPT
-{
-    return !(__a == __b);
-}
-
-#endif  // !defined(_LIBCPP_CXX03_LANG)
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_SCOPED_ALLOCATOR
diff --git a/lib/libcxx/include/set b/lib/libcxx/include/set
deleted file mode 100644
index a0155f0b275..00000000000
--- a/lib/libcxx/include/set
+++ /dev/null
@@ -1,1417 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- set -------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SET
-#define _LIBCPP_SET
-
-/*
-
-    set synopsis
-
-namespace std
-{
-
-template <class Key, class Compare = less<Key>,
-          class Allocator = allocator<Key>>
-class set
-{
-public:
-    // types:
-    typedef Key                                      key_type;
-    typedef key_type                                 value_type;
-    typedef Compare                                  key_compare;
-    typedef key_compare                              value_compare;
-    typedef Allocator                                allocator_type;
-    typedef typename allocator_type::reference       reference;
-    typedef typename allocator_type::const_reference const_reference;
-    typedef typename allocator_type::size_type       size_type;
-    typedef typename allocator_type::difference_type difference_type;
-    typedef typename allocator_type::pointer         pointer;
-    typedef typename allocator_type::const_pointer   const_pointer;
-
-    typedef implementation-defined                   iterator;
-    typedef implementation-defined                   const_iterator;
-    typedef std::reverse_iterator<iterator>          reverse_iterator;
-    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
-    typedef unspecified                              node_type;               // C++17
-    typedef INSERT_RETURN_TYPE<iterator, node_type>  insert_return_type;      // C++17
-
-    // construct/copy/destroy:
-    set()
-        noexcept(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_default_constructible<key_compare>::value &&
-            is_nothrow_copy_constructible<key_compare>::value);
-    explicit set(const value_compare& comp);
-    set(const value_compare& comp, const allocator_type& a);
-    template <class InputIterator>
-        set(InputIterator first, InputIterator last,
-            const value_compare& comp = value_compare());
-    template <class InputIterator>
-        set(InputIterator first, InputIterator last, const value_compare& comp,
-            const allocator_type& a);
-    set(const set& s);
-    set(set&& s)
-        noexcept(
-            is_nothrow_move_constructible<allocator_type>::value &&
-            is_nothrow_move_constructible<key_compare>::value);
-    explicit set(const allocator_type& a);
-    set(const set& s, const allocator_type& a);
-    set(set&& s, const allocator_type& a);
-    set(initializer_list<value_type> il, const value_compare& comp = value_compare());
-    set(initializer_list<value_type> il, const value_compare& comp,
-        const allocator_type& a);
-    template <class InputIterator>
-        set(InputIterator first, InputIterator last, const allocator_type& a)
-            : set(first, last, Compare(), a) {}  // C++14
-    set(initializer_list<value_type> il, const allocator_type& a)
-        : set(il, Compare(), a) {}  // C++14
-    ~set();
-
-    set& operator=(const set& s);
-    set& operator=(set&& s)
-        noexcept(
-            allocator_type::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<allocator_type>::value &&
-            is_nothrow_move_assignable<key_compare>::value);
-    set& operator=(initializer_list<value_type> il);
-
-    // iterators:
-          iterator begin() noexcept;
-    const_iterator begin() const noexcept;
-          iterator end() noexcept;
-    const_iterator end()   const noexcept;
-
-          reverse_iterator rbegin() noexcept;
-    const_reverse_iterator rbegin() const noexcept;
-          reverse_iterator rend() noexcept;
-    const_reverse_iterator rend()   const noexcept;
-
-    const_iterator         cbegin()  const noexcept;
-    const_iterator         cend()    const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend()   const noexcept;
-
-    // capacity:
-    bool      empty()    const noexcept;
-    size_type size()     const noexcept;
-    size_type max_size() const noexcept;
-
-    // modifiers:
-    template <class... Args>
-        pair<iterator, bool> emplace(Args&&... args);
-    template <class... Args>
-        iterator emplace_hint(const_iterator position, Args&&... args);
-    pair<iterator,bool> insert(const value_type& v);
-    pair<iterator,bool> insert(value_type&& v);
-    iterator insert(const_iterator position, const value_type& v);
-    iterator insert(const_iterator position, value_type&& v);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-    void insert(initializer_list<value_type> il);
-
-    node_type extract(const_iterator position);                                       // C++17
-    node_type extract(const key_type& x);                                             // C++17
-    insert_return_type insert(node_type&& nh);                                        // C++17
-    iterator insert(const_iterator hint, node_type&& nh);                             // C++17
-
-    iterator  erase(const_iterator position);
-    iterator  erase(iterator position);  // C++14
-    size_type erase(const key_type& k);
-    iterator  erase(const_iterator first, const_iterator last);
-    void clear() noexcept;
-
-    template<class C2>
-      void merge(set<Key, C2, Allocator>& source);         // C++17
-    template<class C2>
-      void merge(set<Key, C2, Allocator>&& source);        // C++17
-    template<class C2>
-      void merge(multiset<Key, C2, Allocator>& source);    // C++17
-    template<class C2>
-      void merge(multiset<Key, C2, Allocator>&& source);   // C++17
-
-    void swap(set& s)
-        noexcept(
-            __is_nothrow_swappable<key_compare>::value &&
-            (!allocator_type::propagate_on_container_swap::value ||
-             __is_nothrow_swappable<allocator_type>::value));
-
-    // observers:
-    allocator_type get_allocator() const noexcept;
-    key_compare    key_comp()      const;
-    value_compare  value_comp()    const;
-
-    // set operations:
-          iterator find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    template<typename K>
-        iterator find(const K& x);
-    template<typename K>
-        const_iterator find(const K& x) const;  // C++14
-    template<typename K>
-      size_type count(const K& x) const;        // C++14
-
-    size_type      count(const key_type& k) const;
-          iterator lower_bound(const key_type& k);
-    const_iterator lower_bound(const key_type& k) const;
-    template<typename K>
-        iterator lower_bound(const K& x);              // C++14
-    template<typename K>
-        const_iterator lower_bound(const K& x) const;  // C++14
-
-          iterator upper_bound(const key_type& k);
-    const_iterator upper_bound(const key_type& k) const;
-    template<typename K>
-        iterator upper_bound(const K& x);              // C++14
-    template<typename K>
-        const_iterator upper_bound(const K& x) const;  // C++14
-    pair<iterator,iterator>             equal_range(const key_type& k);
-    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
-    template<typename K>
-        pair<iterator,iterator>             equal_range(const K& x);        // C++14
-    template<typename K>
-        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
-};
-
-template <class Key, class Compare, class Allocator>
-bool
-operator==(const set<Key, Compare, Allocator>& x,
-           const set<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator< (const set<Key, Compare, Allocator>& x,
-           const set<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator!=(const set<Key, Compare, Allocator>& x,
-           const set<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator> (const set<Key, Compare, Allocator>& x,
-           const set<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator>=(const set<Key, Compare, Allocator>& x,
-           const set<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator<=(const set<Key, Compare, Allocator>& x,
-           const set<Key, Compare, Allocator>& y);
-
-// specialized algorithms:
-template <class Key, class Compare, class Allocator>
-void
-swap(set<Key, Compare, Allocator>& x, set<Key, Compare, Allocator>& y)
-    noexcept(noexcept(x.swap(y)));
-
-template <class Key, class Compare, class Allocator, class Predicate>
-  void erase_if(set<Key, Compare, Allocator>& c, Predicate pred);  // C++20
-
-template <class Key, class Compare = less<Key>,
-          class Allocator = allocator<Key>>
-class multiset
-{
-public:
-    // types:
-    typedef Key                                      key_type;
-    typedef key_type                                 value_type;
-    typedef Compare                                  key_compare;
-    typedef key_compare                              value_compare;
-    typedef Allocator                                allocator_type;
-    typedef typename allocator_type::reference       reference;
-    typedef typename allocator_type::const_reference const_reference;
-    typedef typename allocator_type::size_type       size_type;
-    typedef typename allocator_type::difference_type difference_type;
-    typedef typename allocator_type::pointer         pointer;
-    typedef typename allocator_type::const_pointer   const_pointer;
-
-    typedef implementation-defined                   iterator;
-    typedef implementation-defined                   const_iterator;
-    typedef std::reverse_iterator<iterator>          reverse_iterator;
-    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
-    typedef unspecified                              node_type;               // C++17
-
-    // construct/copy/destroy:
-    multiset()
-        noexcept(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_default_constructible<key_compare>::value &&
-            is_nothrow_copy_constructible<key_compare>::value);
-    explicit multiset(const value_compare& comp);
-    multiset(const value_compare& comp, const allocator_type& a);
-    template <class InputIterator>
-        multiset(InputIterator first, InputIterator last,
-                 const value_compare& comp = value_compare());
-    template <class InputIterator>
-        multiset(InputIterator first, InputIterator last,
-                 const value_compare& comp, const allocator_type& a);
-    multiset(const multiset& s);
-    multiset(multiset&& s)
-        noexcept(
-            is_nothrow_move_constructible<allocator_type>::value &&
-            is_nothrow_move_constructible<key_compare>::value);
-    explicit multiset(const allocator_type& a);
-    multiset(const multiset& s, const allocator_type& a);
-    multiset(multiset&& s, const allocator_type& a);
-    multiset(initializer_list<value_type> il, const value_compare& comp = value_compare());
-    multiset(initializer_list<value_type> il, const value_compare& comp,
-             const allocator_type& a);
-    template <class InputIterator>
-        multiset(InputIterator first, InputIterator last, const allocator_type& a)
-            : set(first, last, Compare(), a) {}  // C++14
-    multiset(initializer_list<value_type> il, const allocator_type& a)
-        : set(il, Compare(), a) {}  // C++14
-    ~multiset();
-
-    multiset& operator=(const multiset& s);
-    multiset& operator=(multiset&& s)
-        noexcept(
-            allocator_type::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<allocator_type>::value &&
-            is_nothrow_move_assignable<key_compare>::value);
-    multiset& operator=(initializer_list<value_type> il);
-
-    // iterators:
-          iterator begin() noexcept;
-    const_iterator begin() const noexcept;
-          iterator end() noexcept;
-    const_iterator end()   const noexcept;
-
-          reverse_iterator rbegin() noexcept;
-    const_reverse_iterator rbegin() const noexcept;
-          reverse_iterator rend() noexcept;
-    const_reverse_iterator rend()   const noexcept;
-
-    const_iterator         cbegin()  const noexcept;
-    const_iterator         cend()    const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend()   const noexcept;
-
-    // capacity:
-    bool      empty()    const noexcept;
-    size_type size()     const noexcept;
-    size_type max_size() const noexcept;
-
-    // modifiers:
-    template <class... Args>
-        iterator emplace(Args&&... args);
-    template <class... Args>
-        iterator emplace_hint(const_iterator position, Args&&... args);
-    iterator insert(const value_type& v);
-    iterator insert(value_type&& v);
-    iterator insert(const_iterator position, const value_type& v);
-    iterator insert(const_iterator position, value_type&& v);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-    void insert(initializer_list<value_type> il);
-
-    node_type extract(const_iterator position);                                       // C++17
-    node_type extract(const key_type& x);                                             // C++17
-    iterator insert(node_type&& nh);                                                  // C++17
-    iterator insert(const_iterator hint, node_type&& nh);                             // C++17
-
-    iterator  erase(const_iterator position);
-    iterator  erase(iterator position);  // C++14
-    size_type erase(const key_type& k);
-    iterator  erase(const_iterator first, const_iterator last);
-    void clear() noexcept;
-
-    template<class C2>
-      void merge(multiset<Key, C2, Allocator>& source);    // C++17
-    template<class C2>
-      void merge(multiset<Key, C2, Allocator>&& source);   // C++17
-    template<class C2>
-      void merge(set<Key, C2, Allocator>& source);         // C++17
-    template<class C2>
-      void merge(set<Key, C2, Allocator>&& source);        // C++17
-
-    void swap(multiset& s)
-        noexcept(
-            __is_nothrow_swappable<key_compare>::value &&
-            (!allocator_type::propagate_on_container_swap::value ||
-             __is_nothrow_swappable<allocator_type>::value));
-
-    // observers:
-    allocator_type get_allocator() const noexcept;
-    key_compare    key_comp()      const;
-    value_compare  value_comp()    const;
-
-    // set operations:
-          iterator find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    template<typename K>
-        iterator find(const K& x);
-    template<typename K>
-        const_iterator find(const K& x) const;  // C++14
-
-    size_type      count(const key_type& k) const;
-          iterator lower_bound(const key_type& k);
-    const_iterator lower_bound(const key_type& k) const;
-    template<typename K>
-        iterator lower_bound(const K& x);              // C++14
-    template<typename K>
-        const_iterator lower_bound(const K& x) const;  // C++14
-
-          iterator upper_bound(const key_type& k);
-    const_iterator upper_bound(const key_type& k) const;
-    template<typename K>
-        iterator upper_bound(const K& x);              // C++14
-    template<typename K>
-        const_iterator upper_bound(const K& x) const;  // C++14
-
-    pair<iterator,iterator>             equal_range(const key_type& k);
-    pair<const_iterator,const_iterator> equal_range(const key_type& k) const;
-    template<typename K>
-        pair<iterator,iterator>             equal_range(const K& x);        // C++14
-    template<typename K>
-        pair<const_iterator,const_iterator> equal_range(const K& x) const;  // C++14
-};
-
-template <class Key, class Compare, class Allocator>
-bool
-operator==(const multiset<Key, Compare, Allocator>& x,
-           const multiset<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator< (const multiset<Key, Compare, Allocator>& x,
-           const multiset<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator!=(const multiset<Key, Compare, Allocator>& x,
-           const multiset<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator> (const multiset<Key, Compare, Allocator>& x,
-           const multiset<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator>=(const multiset<Key, Compare, Allocator>& x,
-           const multiset<Key, Compare, Allocator>& y);
-
-template <class Key, class Compare, class Allocator>
-bool
-operator<=(const multiset<Key, Compare, Allocator>& x,
-           const multiset<Key, Compare, Allocator>& y);
-
-// specialized algorithms:
-template <class Key, class Compare, class Allocator>
-void
-swap(multiset<Key, Compare, Allocator>& x, multiset<Key, Compare, Allocator>& y)
-    noexcept(noexcept(x.swap(y)));
-
-template <class Key, class Compare, class Allocator, class Predicate>
-  void erase_if(multiset<Key, Compare, Allocator>& c, Predicate pred);  // C++20
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__tree>
-#include <__node_handle>
-#include <functional>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Key, class _Compare, class _Allocator>
-class multiset;
-
-template <class _Key, class _Compare = less<_Key>,
-          class _Allocator = allocator<_Key> >
-class _LIBCPP_TEMPLATE_VIS set
-{
-public:
-    // types:
-    typedef _Key                                     key_type;
-    typedef key_type                                 value_type;
-    typedef _Compare                                 key_compare;
-    typedef key_compare                              value_compare;
-    typedef _Allocator                               allocator_type;
-    typedef value_type&                              reference;
-    typedef const value_type&                        const_reference;
-
-    static_assert(sizeof(__diagnose_non_const_comparator<_Key, _Compare>()), "");
-    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
-                  "Allocator::value_type must be same type as value_type");
-
-private:
-    typedef __tree<value_type, value_compare, allocator_type> __base;
-    typedef allocator_traits<allocator_type>                  __alloc_traits;
-    typedef typename __base::__node_holder                    __node_holder;
-
-    __base __tree_;
-
-public:
-    typedef typename __base::pointer               pointer;
-    typedef typename __base::const_pointer         const_pointer;
-    typedef typename __base::size_type             size_type;
-    typedef typename __base::difference_type       difference_type;
-    typedef typename __base::const_iterator        iterator;
-    typedef typename __base::const_iterator        const_iterator;
-    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
-    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
-
-#if _LIBCPP_STD_VER > 14
-    typedef __set_node_handle<typename __base::__node, allocator_type> node_type;
-    typedef __insert_return_type<iterator, node_type> insert_return_type;
-#endif
-
-    template <class _Key2, class _Compare2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS set;
-    template <class _Key2, class _Compare2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS multiset;
-
-    _LIBCPP_INLINE_VISIBILITY
-    set()
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_default_constructible<key_compare>::value &&
-            is_nothrow_copy_constructible<key_compare>::value)
-        : __tree_(value_compare()) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit set(const value_compare& __comp)
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_copy_constructible<key_compare>::value)
-        : __tree_(__comp) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit set(const value_compare& __comp, const allocator_type& __a)
-        : __tree_(__comp, __a) {}
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        set(_InputIterator __f, _InputIterator __l,
-            const value_compare& __comp = value_compare())
-        : __tree_(__comp)
-        {
-            insert(__f, __l);
-        }
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        set(_InputIterator __f, _InputIterator __l, const value_compare& __comp,
-            const allocator_type& __a)
-        : __tree_(__comp, __a)
-        {
-            insert(__f, __l);
-        }
-
-#if _LIBCPP_STD_VER > 11
-        template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        set(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
-            : set(__f, __l, key_compare(), __a) {}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    set(const set& __s)
-        : __tree_(__s.__tree_)
-        {
-            insert(__s.begin(), __s.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    set& operator=(const set& __s)
-        {
-            __tree_ = __s.__tree_;
-            return *this;
-        }
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    set(set&& __s)
-        _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
-        : __tree_(_VSTD::move(__s.__tree_)) {}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit set(const allocator_type& __a)
-        : __tree_(__a) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    set(const set& __s, const allocator_type& __a)
-        : __tree_(__s.__tree_.value_comp(), __a)
-        {
-            insert(__s.begin(), __s.end());
-        }
-
-#ifndef _LIBCPP_CXX03_LANG
-    set(set&& __s, const allocator_type& __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    set(initializer_list<value_type> __il, const value_compare& __comp = value_compare())
-        : __tree_(__comp)
-        {
-            insert(__il.begin(), __il.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    set(initializer_list<value_type> __il, const value_compare& __comp,
-        const allocator_type& __a)
-        : __tree_(__comp, __a)
-        {
-            insert(__il.begin(), __il.end());
-        }
-
-#if _LIBCPP_STD_VER > 11
-    _LIBCPP_INLINE_VISIBILITY
-    set(initializer_list<value_type> __il, const allocator_type& __a)
-        : set(__il, key_compare(), __a) {}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    set& operator=(initializer_list<value_type> __il)
-        {
-            __tree_.__assign_unique(__il.begin(), __il.end());
-            return *this;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    set& operator=(set&& __s)
-        _NOEXCEPT_(is_nothrow_move_assignable<__base>::value)
-        {
-            __tree_ = _VSTD::move(__s.__tree_);
-            return *this;
-        }
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-          iterator begin() _NOEXCEPT       {return __tree_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT {return __tree_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-          iterator end() _NOEXCEPT         {return __tree_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()   const _NOEXCEPT {return __tree_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rbegin() _NOEXCEPT
-            {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin() const _NOEXCEPT
-        {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rend() _NOEXCEPT
-            {return reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend() const _NOEXCEPT
-        {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin()  const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT {return __tree_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT {return __tree_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {return __tree_.max_size();}
-
-    // modifiers:
-#ifndef _LIBCPP_CXX03_LANG
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> emplace(_Args&&... __args)
-            {return __tree_.__emplace_unique(_VSTD::forward<_Args>(__args)...);}
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator emplace_hint(const_iterator __p, _Args&&... __args)
-            {return __tree_.__emplace_hint_unique(__p, _VSTD::forward<_Args>(__args)...);}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator,bool> insert(const value_type& __v)
-        {return __tree_.__insert_unique(__v);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, const value_type& __v)
-        {return __tree_.__insert_unique(__p, __v);}
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __f, _InputIterator __l)
-        {
-            for (const_iterator __e = cend(); __f != __l; ++__f)
-                __tree_.__insert_unique(__e, *__f);
-        }
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator,bool> insert(value_type&& __v)
-        {return __tree_.__insert_unique(_VSTD::move(__v));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, value_type&& __v)
-        {return __tree_.__insert_unique(__p, _VSTD::move(__v));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(initializer_list<value_type> __il)
-        {insert(__il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator  erase(const_iterator __p) {return __tree_.erase(__p);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k)
-        {return __tree_.__erase_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator  erase(const_iterator __f, const_iterator __l)
-        {return __tree_.erase(__f, __l);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {__tree_.clear();}
-
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY
-    insert_return_type insert(node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to set::insert()");
-        return __tree_.template __node_handle_insert_unique<
-            node_type, insert_return_type>(_VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __hint, node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to set::insert()");
-        return __tree_.template __node_handle_insert_unique<node_type>(
-            __hint, _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(key_type const& __key)
-    {
-        return __tree_.template __node_handle_extract<node_type>(__key);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(const_iterator __it)
-    {
-        return __tree_.template __node_handle_extract<node_type>(__it);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(set<key_type, _Compare2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_unique(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(set<key_type, _Compare2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_unique(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(multiset<key_type, _Compare2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_unique(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(multiset<key_type, _Compare2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_unique(__source.__tree_);
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(set& __s) _NOEXCEPT_(__is_nothrow_swappable<__base>::value)
-        {__tree_.swap(__s.__tree_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT {return __tree_.__alloc();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_compare    key_comp()      const {return __tree_.value_comp();}
-    _LIBCPP_INLINE_VISIBILITY
-    value_compare  value_comp()    const {return __tree_.value_comp();}
-
-    // set operations:
-    _LIBCPP_INLINE_VISIBILITY
-    iterator find(const key_type& __k)             {return __tree_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __tree_.find(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
-    find(const _K2& __k)                           {return __tree_.find(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    find(const _K2& __k) const                     {return __tree_.find(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type      count(const key_type& __k) const
-        {return __tree_.__count_unique(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,size_type>::type
-    count(const _K2& __k) const                    {return __tree_.__count_multi(__k);}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    iterator lower_bound(const key_type& __k)
-        {return __tree_.lower_bound(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator lower_bound(const key_type& __k) const
-        {return __tree_.lower_bound(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
-    lower_bound(const _K2& __k)       {return __tree_.lower_bound(__k);}
-
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    lower_bound(const _K2& __k) const {return __tree_.lower_bound(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator upper_bound(const key_type& __k)
-        {return __tree_.upper_bound(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator upper_bound(const key_type& __k) const
-        {return __tree_.upper_bound(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,iterator>::type
-    upper_bound(const _K2& __k)       {return __tree_.upper_bound(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    upper_bound(const _K2& __k) const {return __tree_.upper_bound(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator,iterator> equal_range(const key_type& __k)
-        {return __tree_.__equal_range_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator,const_iterator> equal_range(const key_type& __k) const
-        {return __tree_.__equal_range_unique(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<iterator,iterator>>::type
-    equal_range(const _K2& __k)       {return __tree_.__equal_range_multi(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,pair<const_iterator,const_iterator>>::type
-    equal_range(const _K2& __k) const {return __tree_.__equal_range_multi(__k);}
-#endif
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Compare, class _Allocator>
-set<_Key, _Compare, _Allocator>::set(set&& __s, const allocator_type& __a)
-    : __tree_(_VSTD::move(__s.__tree_), __a)
-{
-    if (__a != __s.get_allocator())
-    {
-        const_iterator __e = cend();
-        while (!__s.empty())
-            insert(__e, _VSTD::move(__s.__tree_.remove(__s.begin())->__value_));
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const set<_Key, _Compare, _Allocator>& __x,
-           const set<_Key, _Compare, _Allocator>& __y)
-{
-    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const set<_Key, _Compare, _Allocator>& __x,
-           const set<_Key, _Compare, _Allocator>& __y)
-{
-    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const set<_Key, _Compare, _Allocator>& __x,
-           const set<_Key, _Compare, _Allocator>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const set<_Key, _Compare, _Allocator>& __x,
-           const set<_Key, _Compare, _Allocator>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const set<_Key, _Compare, _Allocator>& __x,
-           const set<_Key, _Compare, _Allocator>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const set<_Key, _Compare, _Allocator>& __x,
-           const set<_Key, _Compare, _Allocator>& __y)
-{
-    return !(__y < __x);
-}
-
-// specialized algorithms:
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(set<_Key, _Compare, _Allocator>& __x,
-     set<_Key, _Compare, _Allocator>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Key, class _Compare, class _Allocator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(set<_Key, _Compare, _Allocator>& __c, _Predicate __pred)
-{ __libcpp_erase_if_container(__c, __pred); }
-#endif
-
-template <class _Key, class _Compare = less<_Key>,
-          class _Allocator = allocator<_Key> >
-class _LIBCPP_TEMPLATE_VIS multiset
-{
-public:
-    // types:
-    typedef _Key                                      key_type;
-    typedef key_type                                 value_type;
-    typedef _Compare                                  key_compare;
-    typedef key_compare                              value_compare;
-    typedef _Allocator                                allocator_type;
-    typedef value_type&                              reference;
-    typedef const value_type&                        const_reference;
-
-    static_assert(sizeof(__diagnose_non_const_comparator<_Key, _Compare>()), "");
-    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
-                  "Allocator::value_type must be same type as value_type");
-
-private:
-    typedef __tree<value_type, value_compare, allocator_type> __base;
-    typedef allocator_traits<allocator_type>                  __alloc_traits;
-    typedef typename __base::__node_holder                    __node_holder;
-
-    __base __tree_;
-
-public:
-    typedef typename __base::pointer               pointer;
-    typedef typename __base::const_pointer         const_pointer;
-    typedef typename __base::size_type             size_type;
-    typedef typename __base::difference_type       difference_type;
-    typedef typename __base::const_iterator        iterator;
-    typedef typename __base::const_iterator        const_iterator;
-    typedef _VSTD::reverse_iterator<iterator>       reverse_iterator;
-    typedef _VSTD::reverse_iterator<const_iterator> const_reverse_iterator;
-
-#if _LIBCPP_STD_VER > 14
-    typedef __set_node_handle<typename __base::__node, allocator_type> node_type;
-#endif
-
-    template <class _Key2, class _Compare2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS set;
-    template <class _Key2, class _Compare2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS multiset;
-
-    // construct/copy/destroy:
-    _LIBCPP_INLINE_VISIBILITY
-    multiset()
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_default_constructible<key_compare>::value &&
-            is_nothrow_copy_constructible<key_compare>::value)
-        : __tree_(value_compare()) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit multiset(const value_compare& __comp)
-        _NOEXCEPT_(
-            is_nothrow_default_constructible<allocator_type>::value &&
-            is_nothrow_copy_constructible<key_compare>::value)
-        : __tree_(__comp) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit multiset(const value_compare& __comp, const allocator_type& __a)
-        : __tree_(__comp, __a) {}
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        multiset(_InputIterator __f, _InputIterator __l,
-                 const value_compare& __comp = value_compare())
-        : __tree_(__comp)
-        {
-            insert(__f, __l);
-        }
-
-#if _LIBCPP_STD_VER > 11
-        template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        multiset(_InputIterator __f, _InputIterator __l, const allocator_type& __a)
-            : multiset(__f, __l, key_compare(), __a) {}
-#endif
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        multiset(_InputIterator __f, _InputIterator __l,
-                 const value_compare& __comp, const allocator_type& __a)
-        : __tree_(__comp, __a)
-        {
-            insert(__f, __l);
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    multiset(const multiset& __s)
-        : __tree_(__s.__tree_.value_comp(),
-          __alloc_traits::select_on_container_copy_construction(__s.__tree_.__alloc()))
-        {
-            insert(__s.begin(), __s.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    multiset& operator=(const multiset& __s)
-        {
-            __tree_ = __s.__tree_;
-            return *this;
-        }
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    multiset(multiset&& __s)
-        _NOEXCEPT_(is_nothrow_move_constructible<__base>::value)
-        : __tree_(_VSTD::move(__s.__tree_)) {}
-
-    multiset(multiset&& __s, const allocator_type& __a);
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    explicit multiset(const allocator_type& __a)
-        : __tree_(__a) {}
-    _LIBCPP_INLINE_VISIBILITY
-    multiset(const multiset& __s, const allocator_type& __a)
-        : __tree_(__s.__tree_.value_comp(), __a)
-        {
-            insert(__s.begin(), __s.end());
-        }
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    multiset(initializer_list<value_type> __il, const value_compare& __comp = value_compare())
-        : __tree_(__comp)
-        {
-            insert(__il.begin(), __il.end());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    multiset(initializer_list<value_type> __il, const value_compare& __comp,
-        const allocator_type& __a)
-        : __tree_(__comp, __a)
-        {
-            insert(__il.begin(), __il.end());
-        }
-
-#if _LIBCPP_STD_VER > 11
-    _LIBCPP_INLINE_VISIBILITY
-    multiset(initializer_list<value_type> __il, const allocator_type& __a)
-        : multiset(__il, key_compare(), __a) {}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    multiset& operator=(initializer_list<value_type> __il)
-        {
-            __tree_.__assign_multi(__il.begin(), __il.end());
-            return *this;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    multiset& operator=(multiset&& __s)
-        _NOEXCEPT_(is_nothrow_move_assignable<__base>::value)
-        {
-            __tree_ = _VSTD::move(__s.__tree_);
-            return *this;
-        }
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-          iterator begin() _NOEXCEPT       {return __tree_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT {return __tree_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-          iterator end() _NOEXCEPT         {return __tree_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()   const _NOEXCEPT {return __tree_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rbegin() _NOEXCEPT
-            {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin() const _NOEXCEPT
-        {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-          reverse_iterator rend() _NOEXCEPT
-            {return       reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend() const _NOEXCEPT
-        {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin()  const _NOEXCEPT {return begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend() const _NOEXCEPT {return end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend() const _NOEXCEPT {return rend();}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT {return __tree_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT {return __tree_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {return __tree_.max_size();}
-
-    // modifiers:
-#ifndef _LIBCPP_CXX03_LANG
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator emplace(_Args&&... __args)
-            {return __tree_.__emplace_multi(_VSTD::forward<_Args>(__args)...);}
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator emplace_hint(const_iterator __p, _Args&&... __args)
-            {return __tree_.__emplace_hint_multi(__p, _VSTD::forward<_Args>(__args)...);}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const value_type& __v)
-        {return __tree_.__insert_multi(__v);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, const value_type& __v)
-        {return __tree_.__insert_multi(__p, __v);}
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __f, _InputIterator __l)
-        {
-            for (const_iterator __e = cend(); __f != __l; ++__f)
-                __tree_.__insert_multi(__e, *__f);
-        }
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(value_type&& __v)
-        {return __tree_.__insert_multi(_VSTD::move(__v));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, value_type&& __v)
-        {return __tree_.__insert_multi(__p, _VSTD::move(__v));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(initializer_list<value_type> __il)
-        {insert(__il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator  erase(const_iterator __p) {return __tree_.erase(__p);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __tree_.__erase_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator  erase(const_iterator __f, const_iterator __l)
-        {return __tree_.erase(__f, __l);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {__tree_.clear();}
-
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to multiset::insert()");
-        return __tree_.template __node_handle_insert_multi<node_type>(
-            _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __hint, node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to multiset::insert()");
-        return __tree_.template __node_handle_insert_multi<node_type>(
-            __hint, _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(key_type const& __key)
-    {
-        return __tree_.template __node_handle_extract<node_type>(__key);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(const_iterator __it)
-    {
-        return __tree_.template __node_handle_extract<node_type>(__it);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(multiset<key_type, _Compare2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_multi(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(multiset<key_type, _Compare2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_multi(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(set<key_type, _Compare2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_multi(__source.__tree_);
-    }
-    template <class _Compare2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(set<key_type, _Compare2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __tree_.__node_handle_merge_multi(__source.__tree_);
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(multiset& __s)
-        _NOEXCEPT_(__is_nothrow_swappable<__base>::value)
-        {__tree_.swap(__s.__tree_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT {return __tree_.__alloc();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_compare    key_comp()      const {return __tree_.value_comp();}
-    _LIBCPP_INLINE_VISIBILITY
-    value_compare  value_comp()    const {return __tree_.value_comp();}
-
-    // set operations:
-    _LIBCPP_INLINE_VISIBILITY
-    iterator find(const key_type& __k)             {return __tree_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __tree_.find(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,iterator>::type
-    find(const _K2& __k)                           {return __tree_.find(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    find(const _K2& __k) const                     {return __tree_.find(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type      count(const key_type& __k) const
-        {return __tree_.__count_multi(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename enable_if<__is_transparent<_Compare, _K2>::value,size_type>::type
-    count(const _K2& __k) const            {return __tree_.__count_multi(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator lower_bound(const key_type& __k)
-        {return __tree_.lower_bound(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator lower_bound(const key_type& __k) const
-            {return __tree_.lower_bound(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,iterator>::type
-    lower_bound(const _K2& __k)       {return __tree_.lower_bound(__k);}
-
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    lower_bound(const _K2& __k) const {return __tree_.lower_bound(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator upper_bound(const key_type& __k)
-            {return __tree_.upper_bound(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator upper_bound(const key_type& __k) const
-            {return __tree_.upper_bound(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,iterator>::type
-    upper_bound(const _K2& __k)       {return __tree_.upper_bound(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,const_iterator>::type
-    upper_bound(const _K2& __k) const {return __tree_.upper_bound(__k);}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator,iterator>             equal_range(const key_type& __k)
-            {return __tree_.__equal_range_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator,const_iterator> equal_range(const key_type& __k) const
-            {return __tree_.__equal_range_multi(__k);}
-#if _LIBCPP_STD_VER > 11
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,pair<iterator,iterator>>::type
-    equal_range(const _K2& __k)       {return __tree_.__equal_range_multi(__k);}
-    template <typename _K2>
-    _LIBCPP_INLINE_VISIBILITY
-    typename _VSTD::enable_if<_VSTD::__is_transparent<_Compare, _K2>::value,pair<const_iterator,const_iterator>>::type
-    equal_range(const _K2& __k) const {return __tree_.__equal_range_multi(__k);}
-#endif
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Compare, class _Allocator>
-multiset<_Key, _Compare, _Allocator>::multiset(multiset&& __s, const allocator_type& __a)
-    : __tree_(_VSTD::move(__s.__tree_), __a)
-{
-    if (__a != __s.get_allocator())
-    {
-        const_iterator __e = cend();
-        while (!__s.empty())
-            insert(__e, _VSTD::move(__s.__tree_.remove(__s.begin())->__value_));
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const multiset<_Key, _Compare, _Allocator>& __x,
-           const multiset<_Key, _Compare, _Allocator>& __y)
-{
-    return __x.size() == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const multiset<_Key, _Compare, _Allocator>& __x,
-           const multiset<_Key, _Compare, _Allocator>& __y)
-{
-    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const multiset<_Key, _Compare, _Allocator>& __x,
-           const multiset<_Key, _Compare, _Allocator>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const multiset<_Key, _Compare, _Allocator>& __x,
-           const multiset<_Key, _Compare, _Allocator>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const multiset<_Key, _Compare, _Allocator>& __x,
-           const multiset<_Key, _Compare, _Allocator>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const multiset<_Key, _Compare, _Allocator>& __x,
-           const multiset<_Key, _Compare, _Allocator>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Key, class _Compare, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(multiset<_Key, _Compare, _Allocator>& __x,
-     multiset<_Key, _Compare, _Allocator>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Key, class _Compare, class _Allocator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(multiset<_Key, _Compare, _Allocator>& __c, _Predicate __pred)
-{ __libcpp_erase_if_container(__c, __pred); }
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_SET
diff --git a/lib/libcxx/include/setjmp.h b/lib/libcxx/include/setjmp.h
deleted file mode 100644
index 464b4a54089..00000000000
--- a/lib/libcxx/include/setjmp.h
+++ /dev/null
@@ -1,45 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- setjmp.h ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SETJMP_H
-#define _LIBCPP_SETJMP_H
-
-/*
-    setjmp.h synopsis
-
-Macros:
-
-    setjmp
-
-Types:
-
-    jmp_buf
-
-void longjmp(jmp_buf env, int val);
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <setjmp.h>
-
-#ifdef __cplusplus
-
-#ifndef setjmp
-#define setjmp(env) setjmp(env)
-#endif
-
-#endif // __cplusplus
-
-#endif  // _LIBCPP_SETJMP_H
diff --git a/lib/libcxx/include/shared_mutex b/lib/libcxx/include/shared_mutex
deleted file mode 100644
index 3daf74d26c7..00000000000
--- a/lib/libcxx/include/shared_mutex
+++ /dev/null
@@ -1,509 +0,0 @@
-// -*- C++ -*-
-//===------------------------ shared_mutex --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SHARED_MUTEX
-#define _LIBCPP_SHARED_MUTEX
-
-/*
-    shared_mutex synopsis
-
-// C++1y
-
-namespace std
-{
-
-class shared_mutex      // C++17
-{
-public:
-    shared_mutex();
-    ~shared_mutex();
-
-    shared_mutex(const shared_mutex&) = delete;
-    shared_mutex& operator=(const shared_mutex&) = delete;
-
-    // Exclusive ownership
-    void lock(); // blocking
-    bool try_lock();
-    void unlock();
-
-    // Shared ownership
-    void lock_shared(); // blocking
-    bool try_lock_shared();
-    void unlock_shared();
-
-    typedef implementation-defined native_handle_type; // See 30.2.3
-    native_handle_type native_handle(); // See 30.2.3
-};
-
-class shared_timed_mutex
-{
-public:
-    shared_timed_mutex();
-    ~shared_timed_mutex();
-
-    shared_timed_mutex(const shared_timed_mutex&) = delete;
-    shared_timed_mutex& operator=(const shared_timed_mutex&) = delete;
-
-    // Exclusive ownership
-    void lock(); // blocking
-    bool try_lock();
-    template <class Rep, class Period>
-        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
-    template <class Clock, class Duration>
-        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
-    void unlock();
-
-    // Shared ownership
-    void lock_shared(); // blocking
-    bool try_lock_shared();
-    template <class Rep, class Period>
-        bool
-        try_lock_shared_for(const chrono::duration<Rep, Period>& rel_time);
-    template <class Clock, class Duration>
-        bool
-        try_lock_shared_until(const chrono::time_point<Clock, Duration>& abs_time);
-    void unlock_shared();
-};
-
-template <class Mutex>
-class shared_lock
-{
-public:
-    typedef Mutex mutex_type;
-
-    // Shared locking
-    shared_lock() noexcept;
-    explicit shared_lock(mutex_type& m); // blocking
-    shared_lock(mutex_type& m, defer_lock_t) noexcept;
-    shared_lock(mutex_type& m, try_to_lock_t);
-    shared_lock(mutex_type& m, adopt_lock_t);
-    template <class Clock, class Duration>
-        shared_lock(mutex_type& m,
-                    const chrono::time_point<Clock, Duration>& abs_time);
-    template <class Rep, class Period>
-        shared_lock(mutex_type& m,
-                    const chrono::duration<Rep, Period>& rel_time);
-    ~shared_lock();
-
-    shared_lock(shared_lock const&) = delete;
-    shared_lock& operator=(shared_lock const&) = delete;
-
-    shared_lock(shared_lock&& u) noexcept;
-    shared_lock& operator=(shared_lock&& u) noexcept;
-
-    void lock(); // blocking
-    bool try_lock();
-    template <class Rep, class Period>
-        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
-    template <class Clock, class Duration>
-        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
-    void unlock();
-
-    // Setters
-    void swap(shared_lock& u) noexcept;
-    mutex_type* release() noexcept;
-
-    // Getters
-    bool owns_lock() const noexcept;
-    explicit operator bool () const noexcept;
-    mutex_type* mutex() const noexcept;
-};
-
-template <class Mutex>
-    void swap(shared_lock<Mutex>& x, shared_lock<Mutex>& y) noexcept;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <version>
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-#if _LIBCPP_STD_VER > 11 || defined(_LIBCPP_BUILDING_LIBRARY)
-
-#include <__mutex_base>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef _LIBCPP_HAS_NO_THREADS
-#error <shared_mutex> is not supported on this single threaded system
-#else // !_LIBCPP_HAS_NO_THREADS
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-struct _LIBCPP_TYPE_VIS _LIBCPP_AVAILABILITY_SHARED_MUTEX _LIBCPP_THREAD_SAFETY_ANNOTATION(capability("shared_mutex"))
-__shared_mutex_base
-{
-    mutex               __mut_;
-    condition_variable  __gate1_;
-    condition_variable  __gate2_;
-    unsigned            __state_;
-
-    static const unsigned __write_entered_ = 1U << (sizeof(unsigned)*__CHAR_BIT__ - 1);
-    static const unsigned __n_readers_ = ~__write_entered_;
-
-    __shared_mutex_base();
-    _LIBCPP_INLINE_VISIBILITY ~__shared_mutex_base() = default;
-
-    __shared_mutex_base(const __shared_mutex_base&) = delete;
-    __shared_mutex_base& operator=(const __shared_mutex_base&) = delete;
-
-    // Exclusive ownership
-    void lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_capability()); // blocking
-    bool try_lock() _LIBCPP_THREAD_SAFETY_ANNOTATION(try_acquire_capability(true));
-    void unlock() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_capability());
-
-    // Shared ownership
-    void lock_shared() _LIBCPP_THREAD_SAFETY_ANNOTATION(acquire_shared_capability()); // blocking
-    bool try_lock_shared() _LIBCPP_THREAD_SAFETY_ANNOTATION(try_acquire_shared_capability(true));
-    void unlock_shared() _LIBCPP_THREAD_SAFETY_ANNOTATION(release_shared_capability());
-
-//     typedef implementation-defined native_handle_type; // See 30.2.3
-//     native_handle_type native_handle(); // See 30.2.3
-};
-
-
-#if _LIBCPP_STD_VER > 14
-class _LIBCPP_TYPE_VIS _LIBCPP_AVAILABILITY_SHARED_MUTEX shared_mutex
-{
-    __shared_mutex_base __base;
-public:
-    _LIBCPP_INLINE_VISIBILITY shared_mutex() : __base() {}
-    _LIBCPP_INLINE_VISIBILITY ~shared_mutex() = default;
-
-    shared_mutex(const shared_mutex&) = delete;
-    shared_mutex& operator=(const shared_mutex&) = delete;
-
-    // Exclusive ownership
-    _LIBCPP_INLINE_VISIBILITY void lock()     { return __base.lock(); }
-    _LIBCPP_INLINE_VISIBILITY bool try_lock() { return __base.try_lock(); }
-    _LIBCPP_INLINE_VISIBILITY void unlock()   { return __base.unlock(); }
-
-    // Shared ownership
-    _LIBCPP_INLINE_VISIBILITY void lock_shared()     { return __base.lock_shared(); }
-    _LIBCPP_INLINE_VISIBILITY bool try_lock_shared() { return __base.try_lock_shared(); }
-    _LIBCPP_INLINE_VISIBILITY void unlock_shared()   { return __base.unlock_shared(); }
-
-//     typedef __shared_mutex_base::native_handle_type native_handle_type;
-//     _LIBCPP_INLINE_VISIBILITY native_handle_type native_handle() { return __base::unlock_shared(); }
-};
-#endif
-
-
-class _LIBCPP_TYPE_VIS _LIBCPP_AVAILABILITY_SHARED_MUTEX shared_timed_mutex
-{
-    __shared_mutex_base __base;
-public:
-    shared_timed_mutex();
-    _LIBCPP_INLINE_VISIBILITY ~shared_timed_mutex() = default;
-
-    shared_timed_mutex(const shared_timed_mutex&) = delete;
-    shared_timed_mutex& operator=(const shared_timed_mutex&) = delete;
-
-    // Exclusive ownership
-    void lock();
-    bool try_lock();
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        bool
-        try_lock_for(const chrono::duration<_Rep, _Period>& __rel_time)
-        {
-            return try_lock_until(chrono::steady_clock::now() + __rel_time);
-        }
-    template <class _Clock, class _Duration>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        bool
-        try_lock_until(const chrono::time_point<_Clock, _Duration>& __abs_time);
-    void unlock();
-
-    // Shared ownership
-    void lock_shared();
-    bool try_lock_shared();
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        bool
-        try_lock_shared_for(const chrono::duration<_Rep, _Period>& __rel_time)
-        {
-            return try_lock_shared_until(chrono::steady_clock::now() + __rel_time);
-        }
-    template <class _Clock, class _Duration>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        bool
-        try_lock_shared_until(const chrono::time_point<_Clock, _Duration>& __abs_time);
-    void unlock_shared();
-};
-
-template <class _Clock, class _Duration>
-bool
-shared_timed_mutex::try_lock_until(
-                        const chrono::time_point<_Clock, _Duration>& __abs_time)
-{
-    unique_lock<mutex> __lk(__base.__mut_);
-    if (__base.__state_ & __base.__write_entered_)
-    {
-        while (true)
-        {
-            cv_status __status = __base.__gate1_.wait_until(__lk, __abs_time);
-            if ((__base.__state_ & __base.__write_entered_) == 0)
-                break;
-            if (__status == cv_status::timeout)
-                return false;
-        }
-    }
-    __base.__state_ |= __base.__write_entered_;
-    if (__base.__state_ & __base.__n_readers_)
-    {
-        while (true)
-        {
-            cv_status __status = __base.__gate2_.wait_until(__lk, __abs_time);
-            if ((__base.__state_ & __base.__n_readers_) == 0)
-                break;
-            if (__status == cv_status::timeout)
-            {
-                __base.__state_ &= ~__base.__write_entered_;
-                __base.__gate1_.notify_all();
-                return false;
-            }
-        }
-    }
-    return true;
-}
-
-template <class _Clock, class _Duration>
-bool
-shared_timed_mutex::try_lock_shared_until(
-                        const chrono::time_point<_Clock, _Duration>& __abs_time)
-{
-    unique_lock<mutex> __lk(__base.__mut_);
-    if ((__base.__state_ & __base.__write_entered_) || (__base.__state_ & __base.__n_readers_) == __base.__n_readers_)
-    {
-        while (true)
-        {
-            cv_status status = __base.__gate1_.wait_until(__lk, __abs_time);
-            if ((__base.__state_ & __base.__write_entered_) == 0 &&
-                                       (__base.__state_ & __base.__n_readers_) < __base.__n_readers_)
-                break;
-            if (status == cv_status::timeout)
-                return false;
-        }
-    }
-    unsigned __num_readers = (__base.__state_ & __base.__n_readers_) + 1;
-    __base.__state_ &= ~__base.__n_readers_;
-    __base.__state_ |= __num_readers;
-    return true;
-}
-
-template <class _Mutex>
-class shared_lock
-{
-public:
-    typedef _Mutex mutex_type;
-
-private:
-    mutex_type* __m_;
-    bool __owns_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    shared_lock() _NOEXCEPT
-        : __m_(nullptr),
-          __owns_(false)
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit shared_lock(mutex_type& __m)
-        : __m_(_VSTD::addressof(__m)),
-          __owns_(true)
-        {__m_->lock_shared();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    shared_lock(mutex_type& __m, defer_lock_t) _NOEXCEPT
-        : __m_(_VSTD::addressof(__m)),
-          __owns_(false)
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    shared_lock(mutex_type& __m, try_to_lock_t)
-        : __m_(_VSTD::addressof(__m)),
-          __owns_(__m.try_lock_shared())
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    shared_lock(mutex_type& __m, adopt_lock_t)
-        : __m_(_VSTD::addressof(__m)),
-          __owns_(true)
-        {}
-
-    template <class _Clock, class _Duration>
-        _LIBCPP_INLINE_VISIBILITY
-        shared_lock(mutex_type& __m,
-                    const chrono::time_point<_Clock, _Duration>& __abs_time)
-            : __m_(_VSTD::addressof(__m)),
-              __owns_(__m.try_lock_shared_until(__abs_time))
-            {}
-
-    template <class _Rep, class _Period>
-        _LIBCPP_INLINE_VISIBILITY
-        shared_lock(mutex_type& __m,
-                    const chrono::duration<_Rep, _Period>& __rel_time)
-            : __m_(_VSTD::addressof(__m)),
-              __owns_(__m.try_lock_shared_for(__rel_time))
-            {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~shared_lock()
-    {
-        if (__owns_)
-            __m_->unlock_shared();
-    }
-
-    shared_lock(shared_lock const&) = delete;
-    shared_lock& operator=(shared_lock const&) = delete;
-
-    _LIBCPP_INLINE_VISIBILITY
-    shared_lock(shared_lock&& __u) _NOEXCEPT
-        : __m_(__u.__m_),
-          __owns_(__u.__owns_)
-        {
-            __u.__m_ = nullptr;
-            __u.__owns_ = false;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    shared_lock& operator=(shared_lock&& __u) _NOEXCEPT
-    {
-        if (__owns_)
-            __m_->unlock_shared();
-        __m_ = nullptr;
-        __owns_ = false;
-        __m_ = __u.__m_;
-        __owns_ = __u.__owns_;
-        __u.__m_ = nullptr;
-        __u.__owns_ = false;
-        return *this;
-    }
-
-    void lock();
-    bool try_lock();
-    template <class Rep, class Period>
-        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
-    template <class Clock, class Duration>
-        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
-    void unlock();
-
-    // Setters
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(shared_lock& __u) _NOEXCEPT
-    {
-        _VSTD::swap(__m_, __u.__m_);
-        _VSTD::swap(__owns_, __u.__owns_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    mutex_type* release() _NOEXCEPT
-    {
-        mutex_type* __m = __m_;
-        __m_ = nullptr;
-        __owns_ = false;
-        return __m;
-    }
-
-    // Getters
-    _LIBCPP_INLINE_VISIBILITY
-    bool owns_lock() const _NOEXCEPT {return __owns_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit operator bool () const _NOEXCEPT {return __owns_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    mutex_type* mutex() const _NOEXCEPT {return __m_;}
-};
-
-template <class _Mutex>
-void
-shared_lock<_Mutex>::lock()
-{
-    if (__m_ == nullptr)
-        __throw_system_error(EPERM, "shared_lock::lock: references null mutex");
-    if (__owns_)
-        __throw_system_error(EDEADLK, "shared_lock::lock: already locked");
-    __m_->lock_shared();
-    __owns_ = true;
-}
-
-template <class _Mutex>
-bool
-shared_lock<_Mutex>::try_lock()
-{
-    if (__m_ == nullptr)
-        __throw_system_error(EPERM, "shared_lock::try_lock: references null mutex");
-    if (__owns_)
-        __throw_system_error(EDEADLK, "shared_lock::try_lock: already locked");
-    __owns_ = __m_->try_lock_shared();
-    return __owns_;
-}
-
-template <class _Mutex>
-template <class _Rep, class _Period>
-bool
-shared_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
-{
-    if (__m_ == nullptr)
-        __throw_system_error(EPERM, "shared_lock::try_lock_for: references null mutex");
-    if (__owns_)
-        __throw_system_error(EDEADLK, "shared_lock::try_lock_for: already locked");
-    __owns_ = __m_->try_lock_shared_for(__d);
-    return __owns_;
-}
-
-template <class _Mutex>
-template <class _Clock, class _Duration>
-bool
-shared_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
-{
-    if (__m_ == nullptr)
-        __throw_system_error(EPERM, "shared_lock::try_lock_until: references null mutex");
-    if (__owns_)
-        __throw_system_error(EDEADLK, "shared_lock::try_lock_until: already locked");
-    __owns_ = __m_->try_lock_shared_until(__t);
-    return __owns_;
-}
-
-template <class _Mutex>
-void
-shared_lock<_Mutex>::unlock()
-{
-    if (!__owns_)
-        __throw_system_error(EPERM, "shared_lock::unlock: not locked");
-    __m_->unlock_shared();
-    __owns_ = false;
-}
-
-template <class _Mutex>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(shared_lock<_Mutex>& __x, shared_lock<_Mutex>& __y) _NOEXCEPT
-    {__x.swap(__y);}
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // !_LIBCPP_HAS_NO_THREADS
-
-#endif  // _LIBCPP_STD_VER > 11
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_SHARED_MUTEX
diff --git a/lib/libcxx/include/span b/lib/libcxx/include/span
deleted file mode 100644
index cebe98760f2..00000000000
--- a/lib/libcxx/include/span
+++ /dev/null
@@ -1,564 +0,0 @@
-// -*- C++ -*-
-//===------------------------------ span ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===---------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SPAN
-#define _LIBCPP_SPAN
-
-/*
-    span synopsis
-
-namespace std {
-
-// constants
-inline constexpr ptrdiff_t dynamic_extent = -1;
-
-// [views.span], class template span
-template <class ElementType, ptrdiff_t Extent = dynamic_extent>
-    class span;
-
-// [span.objectrep], views of object representation
-template <class ElementType, ptrdiff_t Extent>
-    span<const byte, ((Extent == dynamic_extent) ? dynamic_extent :
-        (static_cast<ptrdiff_t>(sizeof(ElementType)) * Extent))> as_bytes(span<ElementType, Extent> s) noexcept;
-
-template <class ElementType, ptrdiff_t Extent>
-    span<      byte, ((Extent == dynamic_extent) ? dynamic_extent :
-        (static_cast<ptrdiff_t>(sizeof(ElementType)) * Extent))> as_writable_bytes(span<ElementType, Extent> s) noexcept;
-
-
-namespace std {
-template <class ElementType, ptrdiff_t Extent = dynamic_extent>
-class span {
-public:
-    // constants and types
-    using element_type = ElementType;
-    using value_type = remove_cv_t<ElementType>;
-    using index_type = ptrdiff_t;
-    using difference_type = ptrdiff_t;
-    using pointer = element_type*;
-    using reference = element_type&;
-    using iterator = implementation-defined;
-    using const_iterator = implementation-defined;
-    using reverse_iterator = std::reverse_iterator<iterator>;
-    using const_reverse_iterator = std::reverse_iterator<const_iterator>;
-    static constexpr index_type extent = Extent;
-
-    // [span.cons], span constructors, copy, assignment, and destructor
-    constexpr span() noexcept;
-    constexpr span(pointer ptr, index_type count);
-    constexpr span(pointer firstElem, pointer lastElem);
-    template <size_t N>
-        constexpr span(element_type (&arr)[N]) noexcept;
-    template <size_t N>
-        constexpr span(array<value_type, N>& arr) noexcept;
-    template <size_t N>
-        constexpr span(const array<value_type, N>& arr) noexcept;
-    template <class Container>
-        constexpr span(Container& cont);
-    template <class Container>
-        constexpr span(const Container& cont);
-    constexpr span(const span& other) noexcept = default;
-    template <class OtherElementType, ptrdiff_t OtherExtent>
-        constexpr span(const span<OtherElementType, OtherExtent>& s) noexcept;
-    ~span() noexcept = default;
-    constexpr span& operator=(const span& other) noexcept = default;
-
-    // [span.sub], span subviews
-    template <ptrdiff_t Count>
-        constexpr span<element_type, Count> first() const;
-    template <ptrdiff_t Count>
-        constexpr span<element_type, Count> last() const;
-    template <ptrdiff_t Offset, ptrdiff_t Count = dynamic_extent>
-        constexpr span<element_type, see below> subspan() const;
-
-    constexpr span<element_type, dynamic_extent> first(index_type count) const;
-    constexpr span<element_type, dynamic_extent> last(index_type count) const;
-    constexpr span<element_type, dynamic_extent> subspan(index_type offset, index_type count = dynamic_extent) const;
-
-    // [span.obs], span observers
-    constexpr index_type size() const noexcept;
-    constexpr index_type size_bytes() const noexcept;
-    constexpr bool empty() const noexcept;
-
-    // [span.elem], span element access
-    constexpr reference operator[](index_type idx) const;
-    constexpr reference operator()(index_type idx) const;
-    constexpr pointer data() const noexcept;
-
-    // [span.iterators], span iterator support
-    constexpr iterator begin() const noexcept;
-    constexpr iterator end() const noexcept;
-    constexpr const_iterator cbegin() const noexcept;
-    constexpr const_iterator cend() const noexcept;
-    constexpr reverse_iterator rbegin() const noexcept;
-    constexpr reverse_iterator rend() const noexcept;
-    constexpr const_reverse_iterator crbegin() const noexcept;
-    constexpr const_reverse_iterator crend() const noexcept;
-
-private:
-    pointer data_;     // exposition only
-    index_type size_;  // exposition only
-};
-
-template<class T, size_t N>
-    span(T (&)[N]) -> span<T, N>;
-
-template<class T, size_t N>
-    span(array<T, N>&) -> span<T, N>;
-
-template<class T, size_t N>
-    span(const array<T, N>&) -> span<const T, N>;
-
-template<class Container>
-    span(Container&) -> span<typename Container::value_type>;
-
-template<class Container>
-    span(const Container&) -> span<const typename Container::value_type>;
-
-} // namespace std
-
-*/
-
-#include <__config>
-#include <cstddef>      // for ptrdiff_t
-#include <iterator>     // for iterators
-#include <array>        // for array
-#include <type_traits>  // for remove_cv, etc
-#include <cstddef>      // for byte
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER > 17
-
-inline constexpr ptrdiff_t dynamic_extent = -1;
-template <typename _Tp, ptrdiff_t _Extent = dynamic_extent> class span;
-
-
-template <class _Tp>
-struct __is_span_impl : public false_type {};
-
-template <class _Tp, ptrdiff_t _Extent>
-struct __is_span_impl<span<_Tp, _Extent>> : public true_type {};
-
-template <class _Tp>
-struct __is_span : public __is_span_impl<remove_cv_t<_Tp>> {};
-
-template <class _Tp>
-struct __is_std_array_impl : public false_type {};
-
-template <class _Tp, size_t _Sz>
-struct __is_std_array_impl<array<_Tp, _Sz>> : public true_type {};
-
-template <class _Tp>
-struct __is_std_array : public __is_std_array_impl<remove_cv_t<_Tp>> {};
-
-template <class _Tp, class _ElementType, class = void>
-struct __is_span_compatible_container : public false_type {};
-
-template <class _Tp, class _ElementType>
-struct __is_span_compatible_container<_Tp, _ElementType,
-        void_t<
-        // is not a specialization of span
-            typename enable_if<!__is_span<_Tp>::value, nullptr_t>::type,
-        // is not a specialization of array
-            typename enable_if<!__is_std_array<_Tp>::value, nullptr_t>::type,
-        // is_array_v<Container> is false,
-            typename enable_if<!is_array_v<_Tp>, nullptr_t>::type,
-        // data(cont) and size(cont) are well formed
-            decltype(data(declval<_Tp>())),
-            decltype(size(declval<_Tp>())),
-        // remove_pointer_t<decltype(data(cont))>(*)[] is convertible to ElementType(*)[]
-            typename enable_if<
-                is_convertible_v<remove_pointer_t<decltype(data(declval<_Tp &>()))>(*)[],
-                                 _ElementType(*)[]>,
-                nullptr_t>::type
-        >>
-    : public true_type {};
-
-
-template <typename _Tp, ptrdiff_t _Extent>
-class _LIBCPP_TEMPLATE_VIS span {
-public:
-//  constants and types
-    using element_type           = _Tp;
-    using value_type             = remove_cv_t<_Tp>;
-    using index_type             = ptrdiff_t;
-    using difference_type        = ptrdiff_t;
-    using pointer                = _Tp *;
-    using const_pointer          = const _Tp *; // not in standard
-    using reference              = _Tp &;
-    using const_reference        = const _Tp &; // not in standard
-    using iterator               =  __wrap_iter<pointer>;
-    using const_iterator         =  __wrap_iter<const_pointer>;
-    using reverse_iterator       = _VSTD::reverse_iterator<iterator>;
-    using const_reverse_iterator = _VSTD::reverse_iterator<const_iterator>;
-
-    static constexpr index_type extent = _Extent;
-    static_assert (_Extent >= 0, "Can't have a span with an extent < 0");
-
-// [span.cons], span constructors, copy, assignment, and destructor
-    _LIBCPP_INLINE_VISIBILITY constexpr span() noexcept : __data{nullptr}
-    { static_assert(_Extent == 0, "Can't default construct a statically sized span with size > 0"); }
-
-    constexpr span           (const span&) noexcept = default;
-    constexpr span& operator=(const span&) noexcept = default;
-
-    _LIBCPP_INLINE_VISIBILITY constexpr span(pointer __ptr, index_type __count) : __data{__ptr}
-        { (void)__count; _LIBCPP_ASSERT(_Extent == __count, "size mismatch in span's constructor (ptr, len)"); }
-    _LIBCPP_INLINE_VISIBILITY constexpr span(pointer __f, pointer __l) : __data{__f}
-        { (void)__l;     _LIBCPP_ASSERT(_Extent == distance(__f, __l), "size mismatch in span's constructor (ptr, ptr)"); }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr span(element_type (&__arr)[_Extent])          noexcept : __data{__arr} {}
-    _LIBCPP_INLINE_VISIBILITY constexpr span(      array<value_type, _Extent>& __arr) noexcept : __data{__arr.data()} {}
-    _LIBCPP_INLINE_VISIBILITY constexpr span(const array<value_type, _Extent>& __arr) noexcept : __data{__arr.data()} {}
-
-    template <class _Container>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(      _Container& __c,
-            enable_if_t<__is_span_compatible_container<_Container, _Tp>::value, nullptr_t> = nullptr)
-        : __data{_VSTD::data(__c)}
-        { _LIBCPP_ASSERT(_Extent == _VSTD::size(__c), "size mismatch in span's constructor (container)"); }
-
-    template <class _Container>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(const _Container& __c,
-            enable_if_t<__is_span_compatible_container<const _Container, _Tp>::value, nullptr_t> = nullptr)
-        : __data{_VSTD::data(__c)}
-        { _LIBCPP_ASSERT(_Extent == _VSTD::size(__c), "size mismatch in span's constructor (const container)"); }
-
-    template <class _OtherElementType>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(const span<_OtherElementType, _Extent>& __other,
-                       enable_if_t<
-                          is_convertible_v<_OtherElementType(*)[], element_type (*)[]>,
-                          nullptr_t> = nullptr)
-        : __data{__other.data()} {}
-
-    template <class _OtherElementType>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(const span<_OtherElementType, dynamic_extent>& __other,
-                       enable_if_t<
-                          is_convertible_v<_OtherElementType(*)[], element_type (*)[]>,
-                          nullptr_t> = nullptr) noexcept
-        : __data{__other.data()} { _LIBCPP_ASSERT(_Extent == __other.size(), "size mismatch in span's constructor (other span)"); }
-
-
-//  ~span() noexcept = default;
-
-    template <ptrdiff_t _Count>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span<element_type, _Count> first() const noexcept
-    {
-        static_assert(_Count >= 0, "Count must be >= 0 in span::first()");
-        static_assert(_Count <= _Extent, "Count out of range in span::first()");
-        return {data(), _Count};
-    }
-
-    template <ptrdiff_t _Count>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span<element_type, _Count> last() const noexcept
-    {
-        static_assert(_Count >= 0, "Count must be >= 0 in span::last()");
-        static_assert(_Count <= _Extent, "Count out of range in span::last()");
-        return {data() + size() - _Count, _Count};
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr span<element_type, dynamic_extent> first(index_type __count) const noexcept
-    {
-        _LIBCPP_ASSERT(__count >= 0 && __count <= size(), "Count out of range in span::first(count)");
-        return {data(), __count};
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr span<element_type, dynamic_extent> last(index_type __count) const noexcept
-    {
-        _LIBCPP_ASSERT(__count >= 0 && __count <= size(), "Count out of range in span::last(count)");
-        return {data() + size() - __count, __count};
-    }
-
-    template <ptrdiff_t _Offset, ptrdiff_t _Count = dynamic_extent>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr auto subspan() const noexcept
-        -> span<element_type, _Count != dynamic_extent ? _Count : _Extent - _Offset>
-    {
-        _LIBCPP_ASSERT(_Offset >= 0 && _Offset <= size(), "Offset out of range in span::subspan()");
-        return {data() + _Offset, _Count == dynamic_extent ? size() - _Offset : _Count};
-    }
-
-
-    inline _LIBCPP_INLINE_VISIBILITY
-    constexpr span<element_type, dynamic_extent>
-       subspan(index_type __offset, index_type __count = dynamic_extent) const noexcept
-    {
-        _LIBCPP_ASSERT( __offset >= 0 && __offset <= size(), "Offset out of range in span::subspan(offset, count)");
-        _LIBCPP_ASSERT((__count  >= 0 && __count  <= size()) || __count == dynamic_extent, "Count out of range in span::subspan(offset, count)");
-        if (__count == dynamic_extent)
-            return {data() + __offset, size() - __offset};
-        _LIBCPP_ASSERT(__offset + __count <= size(), "count + offset out of range in span::subspan(offset, count)");
-        return {data() + __offset, __count};
-    }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr index_type size()       const noexcept { return _Extent; }
-    _LIBCPP_INLINE_VISIBILITY constexpr index_type size_bytes() const noexcept { return _Extent * sizeof(element_type); }
-    _LIBCPP_INLINE_VISIBILITY constexpr bool empty()            const noexcept { return _Extent == 0; }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr reference operator[](index_type __idx) const noexcept
-    {
-        _LIBCPP_ASSERT(__idx >= 0 && __idx < size(), "span<T,N>[] index out of bounds");
-        return __data[__idx];
-    }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr reference operator()(index_type __idx) const noexcept
-    {
-        _LIBCPP_ASSERT(__idx >= 0 && __idx < size(), "span<T,N>() index out of bounds");
-        return __data[__idx];
-    }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr pointer data()                         const noexcept { return __data; }
-
-// [span.iter], span iterator support
-    _LIBCPP_INLINE_VISIBILITY constexpr iterator                 begin() const noexcept { return iterator(data()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr iterator                   end() const noexcept { return iterator(data() + size()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr const_iterator          cbegin() const noexcept { return const_iterator(data()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr const_iterator            cend() const noexcept { return const_iterator(data() + size()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr reverse_iterator        rbegin() const noexcept { return reverse_iterator(end()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr reverse_iterator          rend() const noexcept { return reverse_iterator(begin()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(cend()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr const_reverse_iterator   crend() const noexcept { return const_reverse_iterator(cbegin()); }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr void swap(span &__other) noexcept
-    {
-        pointer __p = __data;
-        __data = __other.__data;
-        __other.__data = __p;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY span<const byte, _Extent * sizeof(element_type)> __as_bytes() const noexcept
-    { return {reinterpret_cast<const byte *>(data()), size_bytes()}; }
-
-    _LIBCPP_INLINE_VISIBILITY span<byte, _Extent * sizeof(element_type)> __as_writeable_bytes() const noexcept
-    { return {reinterpret_cast<byte *>(data()), size_bytes()}; }
-
-private:
-    pointer    __data;
-
-};
-
-
-template <typename _Tp>
-class _LIBCPP_TEMPLATE_VIS span<_Tp, dynamic_extent> {
-private:
-
-public:
-//  constants and types
-    using element_type           = _Tp;
-    using value_type             = remove_cv_t<_Tp>;
-    using index_type             = ptrdiff_t;
-    using difference_type        = ptrdiff_t;
-    using pointer                = _Tp *;
-    using const_pointer          = const _Tp *; // not in standard
-    using reference              = _Tp &;
-    using const_reference        = const _Tp &; // not in standard
-    using iterator               =  __wrap_iter<pointer>;
-    using const_iterator         =  __wrap_iter<const_pointer>;
-    using reverse_iterator       = _VSTD::reverse_iterator<iterator>;
-    using const_reverse_iterator = _VSTD::reverse_iterator<const_iterator>;
-
-    static constexpr index_type extent = dynamic_extent;
-
-// [span.cons], span constructors, copy, assignment, and destructor
-    _LIBCPP_INLINE_VISIBILITY constexpr span() noexcept : __data{nullptr}, __size{0} {}
-
-    constexpr span           (const span&) noexcept = default;
-    constexpr span& operator=(const span&) noexcept = default;
-
-    _LIBCPP_INLINE_VISIBILITY constexpr span(pointer __ptr, index_type __count) : __data{__ptr}, __size{__count} {}
-    _LIBCPP_INLINE_VISIBILITY constexpr span(pointer __f, pointer __l) : __data{__f}, __size{distance(__f, __l)} {}
-
-    template <size_t _Sz>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(element_type (&__arr)[_Sz]) noexcept : __data{__arr}, __size{_Sz} {}
-
-    template <size_t _Sz>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(array<value_type, _Sz>& __arr)       noexcept : __data{__arr.data()}, __size{_Sz} {}
-
-    template <size_t _Sz>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(const array<value_type, _Sz>& __arr) noexcept : __data{__arr.data()}, __size{_Sz} {}
-
-    template <class _Container>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(      _Container& __c,
-            enable_if_t<__is_span_compatible_container<_Container, _Tp>::value, nullptr_t> = nullptr)
-        : __data{_VSTD::data(__c)}, __size{(index_type) _VSTD::size(__c)} {}
-
-    template <class _Container>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(const _Container& __c,
-            enable_if_t<__is_span_compatible_container<const _Container, _Tp>::value, nullptr_t> = nullptr)
-        : __data{_VSTD::data(__c)}, __size{(index_type) _VSTD::size(__c)} {}
-
-
-    template <class _OtherElementType, ptrdiff_t _OtherExtent>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span(const span<_OtherElementType, _OtherExtent>& __other,
-                       enable_if_t<
-                          is_convertible_v<_OtherElementType(*)[], element_type (*)[]>,
-                          nullptr_t> = nullptr) noexcept
-        : __data{__other.data()}, __size{__other.size()} {}
-
-//    ~span() noexcept = default;
-
-    template <ptrdiff_t _Count>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span<element_type, _Count> first() const noexcept
-    {
-        static_assert(_Count >= 0, "Count must be >= 0 in span::first()");
-        _LIBCPP_ASSERT(_Count <= size(), "Count out of range in span::first()");
-        return {data(), _Count};
-    }
-
-    template <ptrdiff_t _Count>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span<element_type, _Count> last() const noexcept
-    {
-        static_assert(_Count >= 0, "Count must be >= 0 in span::last()");
-        _LIBCPP_ASSERT(_Count <= size(), "Count out of range in span::last()");
-        return {data() + size() - _Count, _Count};
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr span<element_type, dynamic_extent> first(index_type __count) const noexcept
-    {
-        _LIBCPP_ASSERT(__count >= 0 && __count <= size(), "Count out of range in span::first(count)");
-        return {data(), __count};
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr span<element_type, dynamic_extent> last (index_type __count) const noexcept
-    {
-        _LIBCPP_ASSERT(__count >= 0 && __count <= size(), "Count out of range in span::last(count)");
-        return {data() + size() - __count, __count};
-    }
-
-    template <ptrdiff_t _Offset, ptrdiff_t _Count = dynamic_extent>
-    inline _LIBCPP_INLINE_VISIBILITY
-        constexpr span<_Tp, dynamic_extent> subspan() const noexcept
-    {
-        _LIBCPP_ASSERT(_Offset >= 0 && _Offset <= size(), "Offset out of range in span::subspan()");
-        _LIBCPP_ASSERT(_Count == dynamic_extent || _Offset + _Count <= size(), "Count out of range in span::subspan()");
-        return {data() + _Offset, _Count == dynamic_extent ? size() - _Offset : _Count};
-    }
-
-    constexpr span<element_type, dynamic_extent>
-    inline _LIBCPP_INLINE_VISIBILITY
-       subspan(index_type __offset, index_type __count = dynamic_extent) const noexcept
-    {
-        _LIBCPP_ASSERT( __offset >= 0 && __offset <= size(), "Offset out of range in span::subspan(offset, count)");
-        _LIBCPP_ASSERT((__count  >= 0 && __count  <= size()) || __count == dynamic_extent, "count out of range in span::subspan(offset, count)");
-        if (__count == dynamic_extent)
-            return {data() + __offset, size() - __offset};
-        _LIBCPP_ASSERT(__offset + __count <= size(), "Offset + count out of range in span::subspan(offset, count)");
-        return {data() + __offset, __count};
-    }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr index_type size()       const noexcept { return __size; }
-    _LIBCPP_INLINE_VISIBILITY constexpr index_type size_bytes() const noexcept { return __size * sizeof(element_type); }
-    _LIBCPP_INLINE_VISIBILITY constexpr bool empty()            const noexcept { return __size == 0; }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr reference operator[](index_type __idx) const noexcept
-    {
-        _LIBCPP_ASSERT(__idx >= 0 && __idx < size(), "span<T>[] index out of bounds");
-        return __data[__idx];
-    }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr reference operator()(index_type __idx) const noexcept
-    {
-        _LIBCPP_ASSERT(__idx >= 0 && __idx < size(), "span<T>() index out of bounds");
-        return __data[__idx];
-    }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr pointer data()                         const noexcept { return __data; }
-
-// [span.iter], span iterator support
-    _LIBCPP_INLINE_VISIBILITY constexpr iterator                 begin() const noexcept { return iterator(data()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr iterator                   end() const noexcept { return iterator(data() + size()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr const_iterator          cbegin() const noexcept { return const_iterator(data()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr const_iterator            cend() const noexcept { return const_iterator(data() + size()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr reverse_iterator        rbegin() const noexcept { return reverse_iterator(end()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr reverse_iterator          rend() const noexcept { return reverse_iterator(begin()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(cend()); }
-    _LIBCPP_INLINE_VISIBILITY constexpr const_reverse_iterator   crend() const noexcept { return const_reverse_iterator(cbegin()); }
-
-    _LIBCPP_INLINE_VISIBILITY constexpr void swap(span &__other) noexcept
-    {
-        pointer __p = __data;
-        __data = __other.__data;
-        __other.__data = __p;
-
-        index_type __sz = __size;
-        __size = __other.__size;
-        __other.__size = __sz;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY span<const byte, dynamic_extent> __as_bytes() const noexcept
-    { return {reinterpret_cast<const byte *>(data()), size_bytes()}; }
-
-    _LIBCPP_INLINE_VISIBILITY span<byte, dynamic_extent> __as_writeable_bytes() const noexcept
-    { return {reinterpret_cast<byte *>(data()), size_bytes()}; }
-
-private:
-    pointer    __data;
-    index_type __size;
-};
-
-//  as_bytes & as_writeable_bytes
-template <class _Tp, ptrdiff_t _Extent>
-    auto as_bytes(span<_Tp, _Extent> __s) noexcept
-    -> decltype(__s.__as_bytes())
-    { return __s.__as_bytes(); }
-
-template <class _Tp, ptrdiff_t _Extent>
-    auto as_writeable_bytes(span<_Tp, _Extent> __s) noexcept
-    -> typename enable_if<!is_const_v<_Tp>, decltype(__s.__as_writeable_bytes())>::type
-    { return __s.__as_writeable_bytes(); }
-
-template <class _Tp, ptrdiff_t _Extent>
-    constexpr void swap(span<_Tp, _Extent> &__lhs, span<_Tp, _Extent> &__rhs) noexcept
-    { __lhs.swap(__rhs); }
-
-
-//  Deduction guides
-template<class _Tp, size_t _Sz>
-    span(_Tp (&)[_Sz]) -> span<_Tp, _Sz>;
-
-template<class _Tp, size_t _Sz>
-    span(array<_Tp, _Sz>&) -> span<_Tp, _Sz>;
-
-template<class _Tp, size_t _Sz>
-    span(const array<_Tp, _Sz>&) -> span<const _Tp, _Sz>;
-
-template<class _Container>
-    span(_Container&) -> span<typename _Container::value_type>;
-
-template<class _Container>
-    span(const _Container&) -> span<const typename _Container::value_type>;
-
-#endif // _LIBCPP_STD_VER > 17
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // _LIBCPP_SPAN
diff --git a/lib/libcxx/include/sstream b/lib/libcxx/include/sstream
deleted file mode 100644
index 9c3ee13bfba..00000000000
--- a/lib/libcxx/include/sstream
+++ /dev/null
@@ -1,986 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- sstream ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SSTREAM
-#define _LIBCPP_SSTREAM
-
-/*
-    sstream synopsis
-
-template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
-class basic_stringbuf
-    : public basic_streambuf<charT, traits>
-{
-public:
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-    typedef Allocator                      allocator_type;
-
-    // 27.8.1.1 Constructors:
-    explicit basic_stringbuf(ios_base::openmode which = ios_base::in | ios_base::out);
-    explicit basic_stringbuf(const basic_string<char_type, traits_type, allocator_type>& str,
-                             ios_base::openmode which = ios_base::in | ios_base::out);
-    basic_stringbuf(basic_stringbuf&& rhs);
-
-    // 27.8.1.2 Assign and swap:
-    basic_stringbuf& operator=(basic_stringbuf&& rhs);
-    void swap(basic_stringbuf& rhs);
-
-    // 27.8.1.3 Get and set:
-    basic_string<char_type, traits_type, allocator_type> str() const;
-    void str(const basic_string<char_type, traits_type, allocator_type>& s);
-
-protected:
-    // 27.8.1.4 Overridden virtual functions:
-    virtual int_type underflow();
-    virtual int_type pbackfail(int_type c = traits_type::eof());
-    virtual int_type overflow (int_type c = traits_type::eof());
-    virtual basic_streambuf<char_type, traits_type>* setbuf(char_type*, streamsize);
-    virtual pos_type seekoff(off_type off, ios_base::seekdir way,
-                             ios_base::openmode which = ios_base::in | ios_base::out);
-    virtual pos_type seekpos(pos_type sp,
-                             ios_base::openmode which = ios_base::in | ios_base::out);
-};
-
-template <class charT, class traits, class Allocator>
-  void swap(basic_stringbuf<charT, traits, Allocator>& x,
-            basic_stringbuf<charT, traits, Allocator>& y);
-
-typedef basic_stringbuf<char>    stringbuf;
-typedef basic_stringbuf<wchar_t> wstringbuf;
-
-template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
-class basic_istringstream
-    : public basic_istream<charT, traits>
-{
-public:
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-    typedef Allocator                      allocator_type;
-
-    // 27.8.2.1 Constructors:
-    explicit basic_istringstream(ios_base::openmode which = ios_base::in);
-    explicit basic_istringstream(const basic_string<char_type, traits_type,allocator_type>& str,
-                                 ios_base::openmode which = ios_base::in);
-    basic_istringstream(basic_istringstream&& rhs);
-
-    // 27.8.2.2 Assign and swap:
-    basic_istringstream& operator=(basic_istringstream&& rhs);
-    void swap(basic_istringstream& rhs);
-
-    // 27.8.2.3 Members:
-    basic_stringbuf<char_type, traits_type, allocator_type>* rdbuf() const;
-    basic_string<char_type, traits_type, allocator_type> str() const;
-    void str(const basic_string<char_type, traits_type, allocator_type>& s);
-};
-
-template <class charT, class traits, class Allocator>
-  void swap(basic_istringstream<charT, traits, Allocator>& x,
-            basic_istringstream<charT, traits, Allocator>& y);
-
-typedef basic_istringstream<char>    istringstream;
-typedef basic_istringstream<wchar_t> wistringstream;
-
-template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
-class basic_ostringstream
-    : public basic_ostream<charT, traits>
-{
-public:
-    // types:
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-    typedef Allocator                      allocator_type;
-
-    // 27.8.3.1 Constructors/destructor:
-    explicit basic_ostringstream(ios_base::openmode which = ios_base::out);
-    explicit basic_ostringstream(const basic_string<char_type, traits_type, allocator_type>& str,
-                                 ios_base::openmode which = ios_base::out);
-    basic_ostringstream(basic_ostringstream&& rhs);
-
-    // 27.8.3.2 Assign/swap:
-    basic_ostringstream& operator=(basic_ostringstream&& rhs);
-    void swap(basic_ostringstream& rhs);
-
-    // 27.8.3.3 Members:
-    basic_stringbuf<char_type, traits_type, allocator_type>* rdbuf() const;
-    basic_string<char_type, traits_type, allocator_type> str() const;
-    void str(const basic_string<char_type, traits_type, allocator_type>& s);
-};
-
-template <class charT, class traits, class Allocator>
-  void swap(basic_ostringstream<charT, traits, Allocator>& x,
-            basic_ostringstream<charT, traits, Allocator>& y);
-
-typedef basic_ostringstream<char>    ostringstream;
-typedef basic_ostringstream<wchar_t> wostringstream;
-
-template <class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
-class basic_stringstream
-    : public basic_iostream<charT, traits>
-{
-public:
-    // types:
-    typedef charT                          char_type;
-    typedef traits                         traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-    typedef Allocator                      allocator_type;
-
-    // constructors/destructor
-    explicit basic_stringstream(ios_base::openmode which = ios_base::out|ios_base::in);
-    explicit basic_stringstream(const basic_string<char_type, traits_type, allocator_type>& str,
-                                ios_base::openmode which = ios_base::out|ios_base::in);
-    basic_stringstream(basic_stringstream&& rhs);
-
-    // 27.8.5.1 Assign/swap:
-    basic_stringstream& operator=(basic_stringstream&& rhs);
-    void swap(basic_stringstream& rhs);
-
-    // Members:
-    basic_stringbuf<char_type, traits_type, allocator_type>* rdbuf() const;
-    basic_string<char_type, traits_type, allocator_type> str() const;
-    void str(const basic_string<char_type, traits_type, allocator_type>& str);
-};
-
-template <class charT, class traits, class Allocator>
-  void swap(basic_stringstream<charT, traits, Allocator>& x,
-            basic_stringstream<charT, traits, Allocator>& y);
-
-typedef basic_stringstream<char>    stringstream;
-typedef basic_stringstream<wchar_t> wstringstream;
-
-}  // std
-
-*/
-
-#include <__config>
-#include <ostream>
-#include <istream>
-#include <string>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// basic_stringbuf
-
-template <class _CharT, class _Traits, class _Allocator>
-class _LIBCPP_TEMPLATE_VIS basic_stringbuf
-    : public basic_streambuf<_CharT, _Traits>
-{
-public:
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-    typedef _Allocator                     allocator_type;
-
-    typedef basic_string<char_type, traits_type, allocator_type> string_type;
-
-private:
-
-    string_type __str_;
-    mutable char_type* __hm_;
-    ios_base::openmode __mode_;
-
-public:
-    // 27.8.1.1 Constructors:
-    inline _LIBCPP_INLINE_VISIBILITY
-    explicit basic_stringbuf(ios_base::openmode __wch = ios_base::in | ios_base::out);
-    inline _LIBCPP_INLINE_VISIBILITY
-    explicit basic_stringbuf(const string_type& __s,
-                             ios_base::openmode __wch = ios_base::in | ios_base::out);
-#ifndef _LIBCPP_CXX03_LANG
-    basic_stringbuf(basic_stringbuf&& __rhs);
-
-    // 27.8.1.2 Assign and swap:
-    basic_stringbuf& operator=(basic_stringbuf&& __rhs);
-#endif
-    void swap(basic_stringbuf& __rhs);
-
-    // 27.8.1.3 Get and set:
-    string_type str() const;
-    void str(const string_type& __s);
-
-protected:
-    // 27.8.1.4 Overridden virtual functions:
-    virtual int_type underflow();
-    virtual int_type pbackfail(int_type __c = traits_type::eof());
-    virtual int_type overflow (int_type __c = traits_type::eof());
-    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way,
-                             ios_base::openmode __wch = ios_base::in | ios_base::out);
-    inline _LIBCPP_INLINE_VISIBILITY
-    virtual pos_type seekpos(pos_type __sp,
-                             ios_base::openmode __wch = ios_base::in | ios_base::out);
-};
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringbuf<_CharT, _Traits, _Allocator>::basic_stringbuf(ios_base::openmode __wch)
-    : __hm_(0),
-      __mode_(__wch)
-{
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringbuf<_CharT, _Traits, _Allocator>::basic_stringbuf(const string_type& __s,
-                             ios_base::openmode __wch)
-    : __str_(__s.get_allocator()),
-      __hm_(0),
-      __mode_(__wch)
-{
-    str(__s);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringbuf<_CharT, _Traits, _Allocator>::basic_stringbuf(basic_stringbuf&& __rhs)
-    : __mode_(__rhs.__mode_)
-{
-    char_type* __p = const_cast<char_type*>(__rhs.__str_.data());
-    ptrdiff_t __binp = -1;
-    ptrdiff_t __ninp = -1;
-    ptrdiff_t __einp = -1;
-    if (__rhs.eback() != nullptr)
-    {
-        __binp = __rhs.eback() - __p;
-        __ninp = __rhs.gptr() - __p;
-        __einp = __rhs.egptr() - __p;
-    }
-    ptrdiff_t __bout = -1;
-    ptrdiff_t __nout = -1;
-    ptrdiff_t __eout = -1;
-    if (__rhs.pbase() != nullptr)
-    {
-        __bout = __rhs.pbase() - __p;
-        __nout = __rhs.pptr() - __p;
-        __eout = __rhs.epptr() - __p;
-    }
-    ptrdiff_t __hm = __rhs.__hm_ == nullptr ? -1 : __rhs.__hm_ - __p;
-    __str_ = _VSTD::move(__rhs.__str_);
-    __p = const_cast<char_type*>(__str_.data());
-    if (__binp != -1)
-        this->setg(__p + __binp, __p + __ninp, __p + __einp);
-    if (__bout != -1)
-    {
-        this->setp(__p + __bout, __p + __eout);
-        this->__pbump(__nout);
-    }
-    __hm_ = __hm == -1 ? nullptr : __p + __hm;
-    __p = const_cast<char_type*>(__rhs.__str_.data());
-    __rhs.setg(__p, __p, __p);
-    __rhs.setp(__p, __p);
-    __rhs.__hm_ = __p;
-    this->pubimbue(__rhs.getloc());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringbuf<_CharT, _Traits, _Allocator>&
-basic_stringbuf<_CharT, _Traits, _Allocator>::operator=(basic_stringbuf&& __rhs)
-{
-    char_type* __p = const_cast<char_type*>(__rhs.__str_.data());
-    ptrdiff_t __binp = -1;
-    ptrdiff_t __ninp = -1;
-    ptrdiff_t __einp = -1;
-    if (__rhs.eback() != nullptr)
-    {
-        __binp = __rhs.eback() - __p;
-        __ninp = __rhs.gptr() - __p;
-        __einp = __rhs.egptr() - __p;
-    }
-    ptrdiff_t __bout = -1;
-    ptrdiff_t __nout = -1;
-    ptrdiff_t __eout = -1;
-    if (__rhs.pbase() != nullptr)
-    {
-        __bout = __rhs.pbase() - __p;
-        __nout = __rhs.pptr() - __p;
-        __eout = __rhs.epptr() - __p;
-    }
-    ptrdiff_t __hm = __rhs.__hm_ == nullptr ? -1 : __rhs.__hm_ - __p;
-    __str_ = _VSTD::move(__rhs.__str_);
-    __p = const_cast<char_type*>(__str_.data());
-    if (__binp != -1)
-        this->setg(__p + __binp, __p + __ninp, __p + __einp);
-    else
-        this->setg(nullptr, nullptr, nullptr);
-    if (__bout != -1)
-    {
-        this->setp(__p + __bout, __p + __eout);
-        this->__pbump(__nout);
-    }
-    else
-        this->setp(nullptr, nullptr);
-
-    __hm_ = __hm == -1 ? nullptr : __p + __hm;
-    __mode_ = __rhs.__mode_;
-    __p = const_cast<char_type*>(__rhs.__str_.data());
-    __rhs.setg(__p, __p, __p);
-    __rhs.setp(__p, __p);
-    __rhs.__hm_ = __p;
-    this->pubimbue(__rhs.getloc());
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_stringbuf<_CharT, _Traits, _Allocator>::swap(basic_stringbuf& __rhs)
-{
-    char_type* __p = const_cast<char_type*>(__rhs.__str_.data());
-    ptrdiff_t __rbinp = -1;
-    ptrdiff_t __rninp = -1;
-    ptrdiff_t __reinp = -1;
-    if (__rhs.eback() != nullptr)
-    {
-        __rbinp = __rhs.eback() - __p;
-        __rninp = __rhs.gptr() - __p;
-        __reinp = __rhs.egptr() - __p;
-    }
-    ptrdiff_t __rbout = -1;
-    ptrdiff_t __rnout = -1;
-    ptrdiff_t __reout = -1;
-    if (__rhs.pbase() != nullptr)
-    {
-        __rbout = __rhs.pbase() - __p;
-        __rnout = __rhs.pptr() - __p;
-        __reout = __rhs.epptr() - __p;
-    }
-    ptrdiff_t __rhm = __rhs.__hm_ == nullptr ? -1 : __rhs.__hm_ - __p;
-    __p = const_cast<char_type*>(__str_.data());
-    ptrdiff_t __lbinp = -1;
-    ptrdiff_t __lninp = -1;
-    ptrdiff_t __leinp = -1;
-    if (this->eback() != nullptr)
-    {
-        __lbinp = this->eback() - __p;
-        __lninp = this->gptr() - __p;
-        __leinp = this->egptr() - __p;
-    }
-    ptrdiff_t __lbout = -1;
-    ptrdiff_t __lnout = -1;
-    ptrdiff_t __leout = -1;
-    if (this->pbase() != nullptr)
-    {
-        __lbout = this->pbase() - __p;
-        __lnout = this->pptr() - __p;
-        __leout = this->epptr() - __p;
-    }
-    ptrdiff_t __lhm = __hm_ == nullptr ? -1 : __hm_ - __p;
-    _VSTD::swap(__mode_, __rhs.__mode_);
-    __str_.swap(__rhs.__str_);
-    __p = const_cast<char_type*>(__str_.data());
-    if (__rbinp != -1)
-        this->setg(__p + __rbinp, __p + __rninp, __p + __reinp);
-    else
-        this->setg(nullptr, nullptr, nullptr);
-    if (__rbout != -1)
-    {
-        this->setp(__p + __rbout, __p + __reout);
-        this->__pbump(__rnout);
-    }
-    else
-        this->setp(nullptr, nullptr);
-    __hm_ = __rhm == -1 ? nullptr : __p + __rhm;
-    __p = const_cast<char_type*>(__rhs.__str_.data());
-    if (__lbinp != -1)
-        __rhs.setg(__p + __lbinp, __p + __lninp, __p + __leinp);
-    else
-        __rhs.setg(nullptr, nullptr, nullptr);
-    if (__lbout != -1)
-    {
-        __rhs.setp(__p + __lbout, __p + __leout);
-        __rhs.__pbump(__lnout);
-    }
-    else
-        __rhs.setp(nullptr, nullptr);
-    __rhs.__hm_ = __lhm == -1 ? nullptr : __p + __lhm;
-    locale __tl = __rhs.getloc();
-    __rhs.pubimbue(this->getloc());
-    this->pubimbue(__tl);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_stringbuf<_CharT, _Traits, _Allocator>& __x,
-     basic_stringbuf<_CharT, _Traits, _Allocator>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-basic_stringbuf<_CharT, _Traits, _Allocator>::str() const
-{
-    if (__mode_ & ios_base::out)
-    {
-        if (__hm_ < this->pptr())
-            __hm_ = this->pptr();
-        return string_type(this->pbase(), __hm_, __str_.get_allocator());
-    }
-    else if (__mode_ & ios_base::in)
-        return string_type(this->eback(), this->egptr(), __str_.get_allocator());
-    return string_type(__str_.get_allocator());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_stringbuf<_CharT, _Traits, _Allocator>::str(const string_type& __s)
-{
-    __str_ = __s;
-    __hm_ = 0;
-    if (__mode_ & ios_base::in)
-    {
-        __hm_ = const_cast<char_type*>(__str_.data()) + __str_.size();
-        this->setg(const_cast<char_type*>(__str_.data()),
-                   const_cast<char_type*>(__str_.data()),
-                   __hm_);
-    }
-    if (__mode_ & ios_base::out)
-    {
-        typename string_type::size_type __sz = __str_.size();
-        __hm_ = const_cast<char_type*>(__str_.data()) + __sz;
-        __str_.resize(__str_.capacity());
-        this->setp(const_cast<char_type*>(__str_.data()),
-                   const_cast<char_type*>(__str_.data()) + __str_.size());
-        if (__mode_ & (ios_base::app | ios_base::ate))
-        {
-            while (__sz > INT_MAX)
-            {
-                this->pbump(INT_MAX);
-                __sz -= INT_MAX;
-            }
-            if (__sz > 0)
-                this->pbump(__sz);
-        }
-    }
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-typename basic_stringbuf<_CharT, _Traits, _Allocator>::int_type
-basic_stringbuf<_CharT, _Traits, _Allocator>::underflow()
-{
-    if (__hm_ < this->pptr())
-        __hm_ = this->pptr();
-    if (__mode_ & ios_base::in)
-    {
-        if (this->egptr() < __hm_)
-            this->setg(this->eback(), this->gptr(), __hm_);
-        if (this->gptr() < this->egptr())
-            return traits_type::to_int_type(*this->gptr());
-    }
-    return traits_type::eof();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-typename basic_stringbuf<_CharT, _Traits, _Allocator>::int_type
-basic_stringbuf<_CharT, _Traits, _Allocator>::pbackfail(int_type __c)
-{
-    if (__hm_ < this->pptr())
-        __hm_ = this->pptr();
-    if (this->eback() < this->gptr())
-    {
-        if (traits_type::eq_int_type(__c, traits_type::eof()))
-        {
-            this->setg(this->eback(), this->gptr()-1, __hm_);
-            return traits_type::not_eof(__c);
-        }
-        if ((__mode_ & ios_base::out) ||
-            traits_type::eq(traits_type::to_char_type(__c), this->gptr()[-1]))
-        {
-            this->setg(this->eback(), this->gptr()-1, __hm_);
-            *this->gptr() = traits_type::to_char_type(__c);
-            return __c;
-        }
-    }
-    return traits_type::eof();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-typename basic_stringbuf<_CharT, _Traits, _Allocator>::int_type
-basic_stringbuf<_CharT, _Traits, _Allocator>::overflow(int_type __c)
-{
-    if (!traits_type::eq_int_type(__c, traits_type::eof()))
-    {
-        ptrdiff_t __ninp = this->gptr()  - this->eback();
-        if (this->pptr() == this->epptr())
-        {
-            if (!(__mode_ & ios_base::out))
-                return traits_type::eof();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-            try
-            {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-                ptrdiff_t __nout = this->pptr()  - this->pbase();
-                ptrdiff_t __hm = __hm_ - this->pbase();
-                __str_.push_back(char_type());
-                __str_.resize(__str_.capacity());
-                char_type* __p = const_cast<char_type*>(__str_.data());
-                this->setp(__p, __p + __str_.size());
-                this->__pbump(__nout);
-                __hm_ = this->pbase() + __hm;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-            }
-            catch (...)
-            {
-                return traits_type::eof();
-            }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        }
-        __hm_ = _VSTD::max(this->pptr() + 1, __hm_);
-        if (__mode_ & ios_base::in)
-        {
-            char_type* __p = const_cast<char_type*>(__str_.data());
-            this->setg(__p, __p + __ninp, __hm_);
-        }
-        return this->sputc(__c);
-    }
-    return traits_type::not_eof(__c);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-typename basic_stringbuf<_CharT, _Traits, _Allocator>::pos_type
-basic_stringbuf<_CharT, _Traits, _Allocator>::seekoff(off_type __off,
-                                                      ios_base::seekdir __way,
-                                                      ios_base::openmode __wch)
-{
-    if (__hm_ < this->pptr())
-        __hm_ = this->pptr();
-    if ((__wch & (ios_base::in | ios_base::out)) == 0)
-        return pos_type(-1);
-    if ((__wch & (ios_base::in | ios_base::out)) == (ios_base::in | ios_base::out)
-        && __way == ios_base::cur)
-        return pos_type(-1);
-    const ptrdiff_t __hm = __hm_ == nullptr ? 0 : __hm_ - __str_.data();
-    off_type __noff;
-    switch (__way)
-    {
-    case ios_base::beg:
-        __noff = 0;
-        break;
-    case ios_base::cur:
-        if (__wch & ios_base::in)
-            __noff = this->gptr() - this->eback();
-        else
-            __noff = this->pptr() - this->pbase();
-        break;
-    case ios_base::end:
-        __noff = __hm;
-        break;
-    default:
-        return pos_type(-1);
-    }
-    __noff += __off;
-    if (__noff < 0 || __hm < __noff)
-        return pos_type(-1);
-    if (__noff != 0)
-    {
-        if ((__wch & ios_base::in) && this->gptr() == 0)
-            return pos_type(-1);
-        if ((__wch & ios_base::out) && this->pptr() == 0)
-            return pos_type(-1);
-    }
-    if (__wch & ios_base::in)
-        this->setg(this->eback(), this->eback() + __noff, __hm_);
-    if (__wch & ios_base::out)
-    {
-        this->setp(this->pbase(), this->epptr());
-        this->pbump(__noff);
-    }
-    return pos_type(__noff);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-typename basic_stringbuf<_CharT, _Traits, _Allocator>::pos_type
-basic_stringbuf<_CharT, _Traits, _Allocator>::seekpos(pos_type __sp,
-                                                      ios_base::openmode __wch)
-{
-    return seekoff(__sp, ios_base::beg, __wch);
-}
-
-// basic_istringstream
-
-template <class _CharT, class _Traits, class _Allocator>
-class _LIBCPP_TEMPLATE_VIS basic_istringstream
-    : public basic_istream<_CharT, _Traits>
-{
-public:
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-    typedef _Allocator                     allocator_type;
-
-    typedef basic_string<char_type, traits_type, allocator_type> string_type;
-
-private:
-    basic_stringbuf<char_type, traits_type, allocator_type> __sb_;
-
-public:
-    // 27.8.2.1 Constructors:
-    inline _LIBCPP_INLINE_VISIBILITY
-    explicit basic_istringstream(ios_base::openmode __wch = ios_base::in);
-    inline _LIBCPP_INLINE_VISIBILITY
-    explicit basic_istringstream(const string_type& __s,
-                                 ios_base::openmode __wch = ios_base::in);
-#ifndef _LIBCPP_CXX03_LANG
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_istringstream(basic_istringstream&& __rhs);
-
-    // 27.8.2.2 Assign and swap:
-    basic_istringstream& operator=(basic_istringstream&& __rhs);
-#endif  // _LIBCPP_CXX03_LANG
-    inline _LIBCPP_INLINE_VISIBILITY
-    void swap(basic_istringstream& __rhs);
-
-    // 27.8.2.3 Members:
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_stringbuf<char_type, traits_type, allocator_type>* rdbuf() const;
-    inline _LIBCPP_INLINE_VISIBILITY
-    string_type str() const;
-    inline _LIBCPP_INLINE_VISIBILITY
-    void str(const string_type& __s);
-};
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_istringstream<_CharT, _Traits, _Allocator>::basic_istringstream(ios_base::openmode __wch)
-    : basic_istream<_CharT, _Traits>(&__sb_),
-      __sb_(__wch | ios_base::in)
-{
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_istringstream<_CharT, _Traits, _Allocator>::basic_istringstream(const string_type& __s,
-                                                                      ios_base::openmode __wch)
-    : basic_istream<_CharT, _Traits>(&__sb_),
-      __sb_(__s, __wch | ios_base::in)
-{
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_istringstream<_CharT, _Traits, _Allocator>::basic_istringstream(basic_istringstream&& __rhs)
-    : basic_istream<_CharT, _Traits>(_VSTD::move(__rhs)),
-      __sb_(_VSTD::move(__rhs.__sb_))
-{
-    basic_istream<_CharT, _Traits>::set_rdbuf(&__sb_);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_istringstream<_CharT, _Traits, _Allocator>&
-basic_istringstream<_CharT, _Traits, _Allocator>::operator=(basic_istringstream&& __rhs)
-{
-    basic_istream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
-    __sb_ = _VSTD::move(__rhs.__sb_);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-void basic_istringstream<_CharT, _Traits, _Allocator>::swap(basic_istringstream& __rhs)
-{
-    basic_istream<char_type, traits_type>::swap(__rhs);
-    __sb_.swap(__rhs.__sb_);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_istringstream<_CharT, _Traits, _Allocator>& __x,
-     basic_istringstream<_CharT, _Traits, _Allocator>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringbuf<_CharT, _Traits, _Allocator>*
-basic_istringstream<_CharT, _Traits, _Allocator>::rdbuf() const
-{
-    return const_cast<basic_stringbuf<char_type, traits_type, allocator_type>*>(&__sb_);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-basic_istringstream<_CharT, _Traits, _Allocator>::str() const
-{
-    return __sb_.str();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void basic_istringstream<_CharT, _Traits, _Allocator>::str(const string_type& __s)
-{
-    __sb_.str(__s);
-}
-
-// basic_ostringstream
-
-template <class _CharT, class _Traits, class _Allocator>
-class _LIBCPP_TEMPLATE_VIS basic_ostringstream
-    : public basic_ostream<_CharT, _Traits>
-{
-public:
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-    typedef _Allocator                     allocator_type;
-
-    typedef basic_string<char_type, traits_type, allocator_type> string_type;
-
-private:
-    basic_stringbuf<char_type, traits_type, allocator_type> __sb_;
-
-public:
-    // 27.8.2.1 Constructors:
-    inline _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ostringstream(ios_base::openmode __wch = ios_base::out);
-    inline _LIBCPP_INLINE_VISIBILITY
-    explicit basic_ostringstream(const string_type& __s,
-                                 ios_base::openmode __wch = ios_base::out);
-#ifndef _LIBCPP_CXX03_LANG
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_ostringstream(basic_ostringstream&& __rhs);
-
-    // 27.8.2.2 Assign and swap:
-    basic_ostringstream& operator=(basic_ostringstream&& __rhs);
-#endif  // _LIBCPP_CXX03_LANG
-    inline _LIBCPP_INLINE_VISIBILITY
-    void swap(basic_ostringstream& __rhs);
-
-    // 27.8.2.3 Members:
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_stringbuf<char_type, traits_type, allocator_type>* rdbuf() const;
-    inline _LIBCPP_INLINE_VISIBILITY
-    string_type str() const;
-    inline _LIBCPP_INLINE_VISIBILITY
-    void str(const string_type& __s);
-};
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_ostringstream<_CharT, _Traits, _Allocator>::basic_ostringstream(ios_base::openmode __wch)
-    : basic_ostream<_CharT, _Traits>(&__sb_),
-      __sb_(__wch | ios_base::out)
-{
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_ostringstream<_CharT, _Traits, _Allocator>::basic_ostringstream(const string_type& __s,
-                                                                      ios_base::openmode __wch)
-    : basic_ostream<_CharT, _Traits>(&__sb_),
-      __sb_(__s, __wch | ios_base::out)
-{
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_ostringstream<_CharT, _Traits, _Allocator>::basic_ostringstream(basic_ostringstream&& __rhs)
-    : basic_ostream<_CharT, _Traits>(_VSTD::move(__rhs)),
-      __sb_(_VSTD::move(__rhs.__sb_))
-{
-    basic_ostream<_CharT, _Traits>::set_rdbuf(&__sb_);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_ostringstream<_CharT, _Traits, _Allocator>&
-basic_ostringstream<_CharT, _Traits, _Allocator>::operator=(basic_ostringstream&& __rhs)
-{
-    basic_ostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
-    __sb_ = _VSTD::move(__rhs.__sb_);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_ostringstream<_CharT, _Traits, _Allocator>::swap(basic_ostringstream& __rhs)
-{
-    basic_ostream<char_type, traits_type>::swap(__rhs);
-    __sb_.swap(__rhs.__sb_);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_ostringstream<_CharT, _Traits, _Allocator>& __x,
-     basic_ostringstream<_CharT, _Traits, _Allocator>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringbuf<_CharT, _Traits, _Allocator>*
-basic_ostringstream<_CharT, _Traits, _Allocator>::rdbuf() const
-{
-    return const_cast<basic_stringbuf<char_type, traits_type, allocator_type>*>(&__sb_);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-basic_ostringstream<_CharT, _Traits, _Allocator>::str() const
-{
-    return __sb_.str();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_ostringstream<_CharT, _Traits, _Allocator>::str(const string_type& __s)
-{
-    __sb_.str(__s);
-}
-
-// basic_stringstream
-
-template <class _CharT, class _Traits, class _Allocator>
-class _LIBCPP_TEMPLATE_VIS basic_stringstream
-    : public basic_iostream<_CharT, _Traits>
-{
-public:
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-    typedef _Allocator                     allocator_type;
-
-    typedef basic_string<char_type, traits_type, allocator_type> string_type;
-
-private:
-    basic_stringbuf<char_type, traits_type, allocator_type> __sb_;
-
-public:
-    // 27.8.2.1 Constructors:
-    inline _LIBCPP_INLINE_VISIBILITY
-    explicit basic_stringstream(ios_base::openmode __wch = ios_base::in | ios_base::out);
-    inline _LIBCPP_INLINE_VISIBILITY
-    explicit basic_stringstream(const string_type& __s,
-                                ios_base::openmode __wch = ios_base::in | ios_base::out);
-#ifndef _LIBCPP_CXX03_LANG
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_stringstream(basic_stringstream&& __rhs);
-
-    // 27.8.2.2 Assign and swap:
-    basic_stringstream& operator=(basic_stringstream&& __rhs);
-#endif  // _LIBCPP_CXX03_LANG
-    inline _LIBCPP_INLINE_VISIBILITY
-    void swap(basic_stringstream& __rhs);
-
-    // 27.8.2.3 Members:
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_stringbuf<char_type, traits_type, allocator_type>* rdbuf() const;
-    inline _LIBCPP_INLINE_VISIBILITY
-    string_type str() const;
-    inline _LIBCPP_INLINE_VISIBILITY
-    void str(const string_type& __s);
-};
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringstream<_CharT, _Traits, _Allocator>::basic_stringstream(ios_base::openmode __wch)
-    : basic_iostream<_CharT, _Traits>(&__sb_),
-      __sb_(__wch)
-{
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringstream<_CharT, _Traits, _Allocator>::basic_stringstream(const string_type& __s,
-                                                                    ios_base::openmode __wch)
-    : basic_iostream<_CharT, _Traits>(&__sb_),
-      __sb_(__s, __wch)
-{
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringstream<_CharT, _Traits, _Allocator>::basic_stringstream(basic_stringstream&& __rhs)
-    : basic_iostream<_CharT, _Traits>(_VSTD::move(__rhs)),
-      __sb_(_VSTD::move(__rhs.__sb_))
-{
-    basic_istream<_CharT, _Traits>::set_rdbuf(&__sb_);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringstream<_CharT, _Traits, _Allocator>&
-basic_stringstream<_CharT, _Traits, _Allocator>::operator=(basic_stringstream&& __rhs)
-{
-    basic_iostream<char_type, traits_type>::operator=(_VSTD::move(__rhs));
-    __sb_ = _VSTD::move(__rhs.__sb_);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_stringstream<_CharT, _Traits, _Allocator>::swap(basic_stringstream& __rhs)
-{
-    basic_iostream<char_type, traits_type>::swap(__rhs);
-    __sb_.swap(__rhs.__sb_);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_stringstream<_CharT, _Traits, _Allocator>& __x,
-     basic_stringstream<_CharT, _Traits, _Allocator>& __y)
-{
-    __x.swap(__y);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_stringbuf<_CharT, _Traits, _Allocator>*
-basic_stringstream<_CharT, _Traits, _Allocator>::rdbuf() const
-{
-    return const_cast<basic_stringbuf<char_type, traits_type, allocator_type>*>(&__sb_);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-basic_stringstream<_CharT, _Traits, _Allocator>::str() const
-{
-    return __sb_.str();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_stringstream<_CharT, _Traits, _Allocator>::str(const string_type& __s)
-{
-    __sb_.str(__s);
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_SSTREAM
diff --git a/lib/libcxx/include/stack b/lib/libcxx/include/stack
deleted file mode 100644
index 2b3f8aea19e..00000000000
--- a/lib/libcxx/include/stack
+++ /dev/null
@@ -1,322 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- stack -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_STACK
-#define _LIBCPP_STACK
-
-/*
-    stack synopsis
-
-namespace std
-{
-
-template <class T, class Container = deque<T>>
-class stack
-{
-public:
-    typedef Container                                container_type;
-    typedef typename container_type::value_type      value_type;
-    typedef typename container_type::reference       reference;
-    typedef typename container_type::const_reference const_reference;
-    typedef typename container_type::size_type       size_type;
-
-protected:
-    container_type c;
-
-public:
-    stack() = default;
-    ~stack() = default;
-
-    stack(const stack& q) = default;
-    stack(stack&& q) = default;
-
-    stack& operator=(const stack& q) = default;
-    stack& operator=(stack&& q) = default;
-
-    explicit stack(const container_type& c);
-    explicit stack(container_type&& c);
-    template <class Alloc> explicit stack(const Alloc& a);
-    template <class Alloc> stack(const container_type& c, const Alloc& a);
-    template <class Alloc> stack(container_type&& c, const Alloc& a);
-    template <class Alloc> stack(const stack& c, const Alloc& a);
-    template <class Alloc> stack(stack&& c, const Alloc& a);
-
-    bool empty() const;
-    size_type size() const;
-    reference top();
-    const_reference top() const;
-
-    void push(const value_type& x);
-    void push(value_type&& x);
-    template <class... Args> reference emplace(Args&&... args); // reference in C++17
-    void pop();
-
-    void swap(stack& c) noexcept(is_nothrow_swappable_v<Container>)
-};
-
-template<class Container>
-  stack(Container) -> stack<typename Container::value_type, Container>;  // C++17
-  
-template<class Container, class Allocator> 
-  stack(Container, Allocator) -> stack<typename Container::value_type, Container>; // C++17
-
-template <class T, class Container>
-  bool operator==(const stack<T, Container>& x, const stack<T, Container>& y);
-template <class T, class Container>
-  bool operator< (const stack<T, Container>& x, const stack<T, Container>& y);
-template <class T, class Container>
-  bool operator!=(const stack<T, Container>& x, const stack<T, Container>& y);
-template <class T, class Container>
-  bool operator> (const stack<T, Container>& x, const stack<T, Container>& y);
-template <class T, class Container>
-  bool operator>=(const stack<T, Container>& x, const stack<T, Container>& y);
-template <class T, class Container>
-  bool operator<=(const stack<T, Container>& x, const stack<T, Container>& y);
-
-template <class T, class Container>
-  void swap(stack<T, Container>& x, stack<T, Container>& y)
-  noexcept(noexcept(x.swap(y)));
-
-}  // std
-
-*/
-
-#include <__config>
-#include <deque>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp, class _Container = deque<_Tp> > class _LIBCPP_TEMPLATE_VIS stack;
-
-template <class _Tp, class _Container>
-_LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const stack<_Tp, _Container>& __x, const stack<_Tp, _Container>& __y);
-
-template <class _Tp, class _Container>
-_LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const stack<_Tp, _Container>& __x, const stack<_Tp, _Container>& __y);
-
-template <class _Tp, class _Container /*= deque<_Tp>*/>
-class _LIBCPP_TEMPLATE_VIS stack
-{
-public:
-    typedef _Container                               container_type;
-    typedef typename container_type::value_type      value_type;
-    typedef typename container_type::reference       reference;
-    typedef typename container_type::const_reference const_reference;
-    typedef typename container_type::size_type       size_type;
-    static_assert((is_same<_Tp, value_type>::value), "" );
-    
-protected:
-    container_type c;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    stack()
-        _NOEXCEPT_(is_nothrow_default_constructible<container_type>::value)
-        : c() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    stack(const stack& __q) : c(__q.c) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    stack& operator=(const stack& __q) {c = __q.c; return *this;}
-
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    stack(stack&& __q)
-        _NOEXCEPT_(is_nothrow_move_constructible<container_type>::value)
-        : c(_VSTD::move(__q.c)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    stack& operator=(stack&& __q)
-        _NOEXCEPT_(is_nothrow_move_assignable<container_type>::value)
-        {c = _VSTD::move(__q.c); return *this;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit stack(container_type&& __c) : c(_VSTD::move(__c)) {}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit stack(const container_type& __c) : c(__c) {}
-
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit stack(const _Alloc& __a,
-                       typename enable_if<uses_allocator<container_type,
-                                                         _Alloc>::value>::type* = 0)
-            : c(__a) {}
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        stack(const container_type& __c, const _Alloc& __a,
-              typename enable_if<uses_allocator<container_type,
-                                                _Alloc>::value>::type* = 0)
-            : c(__c, __a) {}
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        stack(const stack& __s, const _Alloc& __a,
-              typename enable_if<uses_allocator<container_type,
-                                                _Alloc>::value>::type* = 0)
-            : c(__s.c, __a) {}
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        stack(container_type&& __c, const _Alloc& __a,
-              typename enable_if<uses_allocator<container_type,
-                                                _Alloc>::value>::type* = 0)
-            : c(_VSTD::move(__c), __a) {}
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        stack(stack&& __s, const _Alloc& __a,
-              typename enable_if<uses_allocator<container_type,
-                                                _Alloc>::value>::type* = 0)
-            : c(_VSTD::move(__s.c), __a) {}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty()     const      {return c.empty();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const      {return c.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    reference top()             {return c.back();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference top() const {return c.back();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void push(const value_type& __v) {c.push_back(__v);}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void push(value_type&& __v) {c.push_back(_VSTD::move(__v));}
-
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-#if _LIBCPP_STD_VER > 14
-        decltype(auto) emplace(_Args&&... __args)
-        { return c.emplace_back(_VSTD::forward<_Args>(__args)...);}
-#else
-        void      emplace(_Args&&... __args)
-        {        c.emplace_back(_VSTD::forward<_Args>(__args)...);}
-#endif
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    void pop() {c.pop_back();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(stack& __s)
-        _NOEXCEPT_(__is_nothrow_swappable<container_type>::value)
-    {
-        using _VSTD::swap;
-        swap(c, __s.c);
-    }
-
-    template <class T1, class _C1>
-    friend
-    bool
-    operator==(const stack<T1, _C1>& __x, const stack<T1, _C1>& __y);
-
-    template <class T1, class _C1>
-    friend
-    bool
-    operator< (const stack<T1, _C1>& __x, const stack<T1, _C1>& __y);
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class _Container,
-         class = typename enable_if<!__is_allocator<_Container>::value, nullptr_t>::type
->
-stack(_Container)
-    -> stack<typename _Container::value_type, _Container>;
-  
-template<class _Container,
-         class _Alloc,
-         class = typename enable_if<!__is_allocator<_Container>::value, nullptr_t>::type,
-         class = typename enable_if< __is_allocator<_Alloc>::value, nullptr_t>::type
-         > 
-stack(_Container, _Alloc)
-    -> stack<typename _Container::value_type, _Container>;
-#endif
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const stack<_Tp, _Container>& __x, const stack<_Tp, _Container>& __y)
-{
-    return __x.c == __y.c;
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const stack<_Tp, _Container>& __x, const stack<_Tp, _Container>& __y)
-{
-    return __x.c < __y.c;
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const stack<_Tp, _Container>& __x, const stack<_Tp, _Container>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const stack<_Tp, _Container>& __x, const stack<_Tp, _Container>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const stack<_Tp, _Container>& __x, const stack<_Tp, _Container>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const stack<_Tp, _Container>& __x, const stack<_Tp, _Container>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Tp, class _Container>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if<
-    __is_swappable<_Container>::value,
-    void
->::type
-swap(stack<_Tp, _Container>& __x, stack<_Tp, _Container>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-template <class _Tp, class _Container, class _Alloc>
-struct _LIBCPP_TEMPLATE_VIS uses_allocator<stack<_Tp, _Container>, _Alloc>
-    : public uses_allocator<_Container, _Alloc>
-{
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_STACK
diff --git a/lib/libcxx/include/stdbool.h b/lib/libcxx/include/stdbool.h
deleted file mode 100644
index 86a127f0fd6..00000000000
--- a/lib/libcxx/include/stdbool.h
+++ /dev/null
@@ -1,39 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- stdbool.h --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-#ifndef _LIBCPP_STDBOOL_H
-#define _LIBCPP_STDBOOL_H
-
-
-/*
-    stdbool.h synopsis
-
-Macros:
-
-    __bool_true_false_are_defined
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <stdbool.h>
-
-#ifdef __cplusplus
-#undef bool
-#undef true
-#undef false
-#undef __bool_true_false_are_defined
-#define __bool_true_false_are_defined 1
-#endif
-
-#endif  // _LIBCPP_STDBOOL_H
diff --git a/lib/libcxx/include/stddef.h b/lib/libcxx/include/stddef.h
deleted file mode 100644
index f65065d869a..00000000000
--- a/lib/libcxx/include/stddef.h
+++ /dev/null
@@ -1,63 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- stddef.h ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#if defined(__need_ptrdiff_t) || defined(__need_size_t) || \
-    defined(__need_wchar_t) || defined(__need_NULL) || defined(__need_wint_t)
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <stddef.h>
-
-#elif !defined(_LIBCPP_STDDEF_H)
-#define _LIBCPP_STDDEF_H
-
-/*
-    stddef.h synopsis
-
-Macros:
-
-    offsetof(type,member-designator)
-    NULL
-
-Types:
-
-    ptrdiff_t
-    size_t
-    max_align_t
-    nullptr_t
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <stddef.h>
-
-#ifdef __cplusplus
-
-extern "C++" {
-#include <__nullptr>
-using std::nullptr_t;
-}
-
-// Re-use the compiler's <stddef.h> max_align_t where possible.
-#if !defined(__CLANG_MAX_ALIGN_T_DEFINED) && !defined(_GCC_MAX_ALIGN_T) && \
-    !defined(__DEFINED_max_align_t) && !defined(__NetBSD__)
-typedef long double max_align_t;
-#endif
-
-#endif
-
-#endif  // _LIBCPP_STDDEF_H
diff --git a/lib/libcxx/include/stdexcept b/lib/libcxx/include/stdexcept
deleted file mode 100644
index 3ec79349aa9..00000000000
--- a/lib/libcxx/include/stdexcept
+++ /dev/null
@@ -1,278 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- stdexcept --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_STDEXCEPT
-#define _LIBCPP_STDEXCEPT
-
-/*
-    stdexcept synopsis
-
-namespace std
-{
-
-class logic_error;
-    class domain_error;
-    class invalid_argument;
-    class length_error;
-    class out_of_range;
-class runtime_error;
-    class range_error;
-    class overflow_error;
-    class underflow_error;
-
-for each class xxx_error:
-
-class xxx_error : public exception // at least indirectly
-{
-public:
-    explicit xxx_error(const string& what_arg);
-    explicit xxx_error(const char*   what_arg);
-
-    virtual const char* what() const noexcept // returns what_arg
-};
-
-}  // std
-
-*/
-
-#include <__config>
-#include <exception>
-#include <iosfwd>  // for string forward decl
-#ifdef _LIBCPP_NO_EXCEPTIONS
-#include <cstdlib>
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-class _LIBCPP_HIDDEN __libcpp_refstring
-{
-    const char* __imp_;
-
-    bool __uses_refcount() const;
-public:
-    explicit __libcpp_refstring(const char* __msg);
-    __libcpp_refstring(const __libcpp_refstring& __s) _NOEXCEPT;
-    __libcpp_refstring& operator=(const __libcpp_refstring& __s) _NOEXCEPT;
-    ~__libcpp_refstring();
-
-    const char* c_str() const _NOEXCEPT {return __imp_;}
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-namespace std  // purposefully not using versioning namespace
-{
-
-class _LIBCPP_EXCEPTION_ABI logic_error
-    : public exception
-{
-private:
-    _VSTD::__libcpp_refstring __imp_;
-public:
-    explicit logic_error(const string&);
-    explicit logic_error(const char*);
-
-    logic_error(const logic_error&) _NOEXCEPT;
-    logic_error& operator=(const logic_error&) _NOEXCEPT;
-
-    virtual ~logic_error() _NOEXCEPT;
-
-    virtual const char* what() const _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI runtime_error
-    : public exception
-{
-private:
-    _VSTD::__libcpp_refstring __imp_;
-public:
-    explicit runtime_error(const string&);
-    explicit runtime_error(const char*);
-
-    runtime_error(const runtime_error&) _NOEXCEPT;
-    runtime_error& operator=(const runtime_error&) _NOEXCEPT;
-
-    virtual ~runtime_error() _NOEXCEPT;
-
-    virtual const char* what() const _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI domain_error
-    : public logic_error
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit domain_error(const string& __s) : logic_error(__s) {}
-    _LIBCPP_INLINE_VISIBILITY explicit domain_error(const char* __s)   : logic_error(__s) {}
-
-    virtual ~domain_error() _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI invalid_argument
-    : public logic_error
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit invalid_argument(const string& __s) : logic_error(__s) {}
-    _LIBCPP_INLINE_VISIBILITY explicit invalid_argument(const char* __s)   : logic_error(__s) {}
-
-    virtual ~invalid_argument() _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI length_error
-    : public logic_error
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit length_error(const string& __s) : logic_error(__s) {}
-    _LIBCPP_INLINE_VISIBILITY explicit length_error(const char* __s)   : logic_error(__s) {}
-
-    virtual ~length_error() _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI out_of_range
-    : public logic_error
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit out_of_range(const string& __s) : logic_error(__s) {}
-    _LIBCPP_INLINE_VISIBILITY explicit out_of_range(const char* __s)   : logic_error(__s) {}
-
-    virtual ~out_of_range() _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI range_error
-    : public runtime_error
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit range_error(const string& __s) : runtime_error(__s) {}
-    _LIBCPP_INLINE_VISIBILITY explicit range_error(const char* __s)   : runtime_error(__s) {}
-
-    virtual ~range_error() _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI overflow_error
-    : public runtime_error
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit overflow_error(const string& __s) : runtime_error(__s) {}
-    _LIBCPP_INLINE_VISIBILITY explicit overflow_error(const char* __s)   : runtime_error(__s) {}
-
-    virtual ~overflow_error() _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI underflow_error
-    : public runtime_error
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY explicit underflow_error(const string& __s) : runtime_error(__s) {}
-    _LIBCPP_INLINE_VISIBILITY explicit underflow_error(const char* __s)   : runtime_error(__s) {}
-
-    virtual ~underflow_error() _NOEXCEPT;
-};
-
-}  // std
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// in the dylib
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS void __throw_runtime_error(const char*);
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_logic_error(const char*__msg)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw logic_error(__msg);
-#else
-    ((void)__msg);
-    _VSTD::abort();
-#endif
-}
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_domain_error(const char*__msg)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw domain_error(__msg);
-#else
-    ((void)__msg);
-    _VSTD::abort();
-#endif
-}
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_invalid_argument(const char*__msg)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw invalid_argument(__msg);
-#else
-    ((void)__msg);
-    _VSTD::abort();
-#endif
-}
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_length_error(const char*__msg)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw length_error(__msg);
-#else
-    ((void)__msg);
-    _VSTD::abort();
-#endif
-}
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_out_of_range(const char*__msg)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw out_of_range(__msg);
-#else
-    ((void)__msg);
-    _VSTD::abort();
-#endif
-}
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_range_error(const char*__msg)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw range_error(__msg);
-#else
-    ((void)__msg);
-    _VSTD::abort();
-#endif
-}
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_overflow_error(const char*__msg)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw overflow_error(__msg);
-#else
-    ((void)__msg);
-    _VSTD::abort();
-#endif
-}
-
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_underflow_error(const char*__msg)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw underflow_error(__msg);
-#else
-    ((void)__msg);
-    _VSTD::abort();
-#endif
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_STDEXCEPT
diff --git a/lib/libcxx/include/stdint.h b/lib/libcxx/include/stdint.h
deleted file mode 100644
index 468f6cd97c2..00000000000
--- a/lib/libcxx/include/stdint.h
+++ /dev/null
@@ -1,121 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- stdint.h --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_STDINT_H
-#define _LIBCPP_STDINT_H
-
-/*
-    stdint.h synopsis
-
-Macros:
-
-    INT8_MIN
-    INT16_MIN
-    INT32_MIN
-    INT64_MIN
-
-    INT8_MAX
-    INT16_MAX
-    INT32_MAX
-    INT64_MAX
-
-    UINT8_MAX
-    UINT16_MAX
-    UINT32_MAX
-    UINT64_MAX
-
-    INT_LEAST8_MIN
-    INT_LEAST16_MIN
-    INT_LEAST32_MIN
-    INT_LEAST64_MIN
-
-    INT_LEAST8_MAX
-    INT_LEAST16_MAX
-    INT_LEAST32_MAX
-    INT_LEAST64_MAX
-
-    UINT_LEAST8_MAX
-    UINT_LEAST16_MAX
-    UINT_LEAST32_MAX
-    UINT_LEAST64_MAX
-
-    INT_FAST8_MIN
-    INT_FAST16_MIN
-    INT_FAST32_MIN
-    INT_FAST64_MIN
-
-    INT_FAST8_MAX
-    INT_FAST16_MAX
-    INT_FAST32_MAX
-    INT_FAST64_MAX
-
-    UINT_FAST8_MAX
-    UINT_FAST16_MAX
-    UINT_FAST32_MAX
-    UINT_FAST64_MAX
-
-    INTPTR_MIN
-    INTPTR_MAX
-    UINTPTR_MAX
-
-    INTMAX_MIN
-    INTMAX_MAX
-
-    UINTMAX_MAX
-
-    PTRDIFF_MIN
-    PTRDIFF_MAX
-
-    SIG_ATOMIC_MIN
-    SIG_ATOMIC_MAX
-
-    SIZE_MAX
-
-    WCHAR_MIN
-    WCHAR_MAX
-
-    WINT_MIN
-    WINT_MAX
-
-    INT8_C(value)
-    INT16_C(value)
-    INT32_C(value)
-    INT64_C(value)
-
-    UINT8_C(value)
-    UINT16_C(value)
-    UINT32_C(value)
-    UINT64_C(value)
-
-    INTMAX_C(value)
-    UINTMAX_C(value)
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-/* C99 stdlib (e.g. glibc < 2.18) does not provide macros needed
-   for C++11 unless __STDC_LIMIT_MACROS and __STDC_CONSTANT_MACROS
-   are defined
-*/
-#if defined(__cplusplus) && !defined(__STDC_LIMIT_MACROS)
-#   define __STDC_LIMIT_MACROS
-#endif
-#if defined(__cplusplus) && !defined(__STDC_CONSTANT_MACROS)
-#   define __STDC_CONSTANT_MACROS
-#endif
-
-#include_next <stdint.h>
-
-#endif  // _LIBCPP_STDINT_H
diff --git a/lib/libcxx/include/stdio.h b/lib/libcxx/include/stdio.h
deleted file mode 100644
index b2e7cc28c98..00000000000
--- a/lib/libcxx/include/stdio.h
+++ /dev/null
@@ -1,122 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- stdio.h ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#if defined(__need_FILE) || defined(__need___FILE)
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <stdio.h>
-
-#elif !defined(_LIBCPP_STDIO_H)
-#define _LIBCPP_STDIO_H
-
-/*
-    stdio.h synopsis
-
-Macros:
-
-    BUFSIZ
-    EOF
-    FILENAME_MAX
-    FOPEN_MAX
-    L_tmpnam
-    NULL
-    SEEK_CUR
-    SEEK_END
-    SEEK_SET
-    TMP_MAX
-    _IOFBF
-    _IOLBF
-    _IONBF
-    stderr
-    stdin
-    stdout
-
-Types:
-
-FILE
-fpos_t
-size_t
-
-int remove(const char* filename);
-int rename(const char* old, const char* new);
-FILE* tmpfile(void);
-char* tmpnam(char* s);
-int fclose(FILE* stream);
-int fflush(FILE* stream);
-FILE* fopen(const char* restrict filename, const char* restrict mode);
-FILE* freopen(const char* restrict filename, const char * restrict mode,
-              FILE * restrict stream);
-void setbuf(FILE* restrict stream, char* restrict buf);
-int setvbuf(FILE* restrict stream, char* restrict buf, int mode, size_t size);
-int fprintf(FILE* restrict stream, const char* restrict format, ...);
-int fscanf(FILE* restrict stream, const char * restrict format, ...);
-int printf(const char* restrict format, ...);
-int scanf(const char* restrict format, ...);
-int snprintf(char* restrict s, size_t n, const char* restrict format, ...);    // C99
-int sprintf(char* restrict s, const char* restrict format, ...);
-int sscanf(const char* restrict s, const char* restrict format, ...);
-int vfprintf(FILE* restrict stream, const char* restrict format, va_list arg);
-int vfscanf(FILE* restrict stream, const char* restrict format, va_list arg);  // C99
-int vprintf(const char* restrict format, va_list arg);
-int vscanf(const char* restrict format, va_list arg);                          // C99
-int vsnprintf(char* restrict s, size_t n, const char* restrict format,         // C99
-              va_list arg);
-int vsprintf(char* restrict s, const char* restrict format, va_list arg);
-int vsscanf(const char* restrict s, const char* restrict format, va_list arg); // C99
-int fgetc(FILE* stream);
-char* fgets(char* restrict s, int n, FILE* restrict stream);
-int fputc(int c, FILE* stream);
-int fputs(const char* restrict s, FILE* restrict stream);
-int getc(FILE* stream);
-int getchar(void);
-char* gets(char* s);  // removed in C++14
-int putc(int c, FILE* stream);
-int putchar(int c);
-int puts(const char* s);
-int ungetc(int c, FILE* stream);
-size_t fread(void* restrict ptr, size_t size, size_t nmemb,
-             FILE* restrict stream);
-size_t fwrite(const void* restrict ptr, size_t size, size_t nmemb,
-              FILE* restrict stream);
-int fgetpos(FILE* restrict stream, fpos_t* restrict pos);
-int fseek(FILE* stream, long offset, int whence);
-int fsetpos(FILE*stream, const fpos_t* pos);
-long ftell(FILE* stream);
-void rewind(FILE* stream);
-void clearerr(FILE* stream);
-int feof(FILE* stream);
-int ferror(FILE* stream);
-void perror(const char* s);
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <stdio.h>
-
-#ifdef __cplusplus
-
-#undef getc
-#undef putc
-#undef clearerr
-#undef feof
-#undef ferror
-#undef putchar
-#undef getchar
-
-#endif
-
-#endif  // _LIBCPP_STDIO_H
diff --git a/lib/libcxx/include/stdlib.h b/lib/libcxx/include/stdlib.h
deleted file mode 100644
index f11c5e76226..00000000000
--- a/lib/libcxx/include/stdlib.h
+++ /dev/null
@@ -1,126 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- stdlib.h ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#if defined(__need_malloc_and_calloc)
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <stdlib.h>
-
-#elif !defined(_LIBCPP_STDLIB_H)
-#define _LIBCPP_STDLIB_H
-
-/*
-    stdlib.h synopsis
-
-Macros:
-
-    EXIT_FAILURE
-    EXIT_SUCCESS
-    MB_CUR_MAX
-    NULL
-    RAND_MAX
-
-Types:
-
-    size_t
-    div_t
-    ldiv_t
-    lldiv_t                                                               // C99
-
-double    atof (const char* nptr);
-int       atoi (const char* nptr);
-long      atol (const char* nptr);
-long long atoll(const char* nptr);                                        // C99
-double             strtod  (const char* restrict nptr, char** restrict endptr);
-float              strtof  (const char* restrict nptr, char** restrict endptr); // C99
-long double        strtold (const char* restrict nptr, char** restrict endptr); // C99
-long               strtol  (const char* restrict nptr, char** restrict endptr, int base);
-long long          strtoll (const char* restrict nptr, char** restrict endptr, int base); // C99
-unsigned long      strtoul (const char* restrict nptr, char** restrict endptr, int base);
-unsigned long long strtoull(const char* restrict nptr, char** restrict endptr, int base); // C99
-int rand(void);
-void srand(unsigned int seed);
-void* calloc(size_t nmemb, size_t size);
-void free(void* ptr);
-void* malloc(size_t size);
-void* realloc(void* ptr, size_t size);
-void abort(void);
-int atexit(void (*func)(void));
-void exit(int status);
-void _Exit(int status);
-char* getenv(const char* name);
-int system(const char* string);
-void* bsearch(const void* key, const void* base, size_t nmemb, size_t size,
-              int (*compar)(const void *, const void *));
-void qsort(void* base, size_t nmemb, size_t size,
-           int (*compar)(const void *, const void *));
-int         abs(      int j);
-long        abs(     long j);
-long long   abs(long long j);                                             // C++0X
-long       labs(     long j);
-long long llabs(long long j);                                             // C99
-div_t     div(      int numer,       int denom);
-ldiv_t    div(     long numer,      long denom);
-lldiv_t   div(long long numer, long long denom);                          // C++0X
-ldiv_t   ldiv(     long numer,      long denom);
-lldiv_t lldiv(long long numer, long long denom);                          // C99
-int mblen(const char* s, size_t n);
-int mbtowc(wchar_t* restrict pwc, const char* restrict s, size_t n);
-int wctomb(char* s, wchar_t wchar);
-size_t mbstowcs(wchar_t* restrict pwcs, const char* restrict s, size_t n);
-size_t wcstombs(char* restrict s, const wchar_t* restrict pwcs, size_t n);
-int at_quick_exit(void (*func)(void))                                     // C++11
-void quick_exit(int status);                                              // C++11
-void *aligned_alloc(size_t alignment, size_t size);                       // C11
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <stdlib.h>
-
-#ifdef __cplusplus
-
-extern "C++" {
-
-#undef abs
-#undef div
-#undef labs
-#undef ldiv
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-#undef llabs
-#undef lldiv
-#endif
-
-// MSVCRT already has the correct prototype in <stdlib.h> if __cplusplus is defined
-#if !defined(_LIBCPP_MSVCRT) && !defined(__sun__) && !defined(_AIX)
-inline _LIBCPP_INLINE_VISIBILITY long      abs(     long __x) _NOEXCEPT {return  labs(__x);}
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-inline _LIBCPP_INLINE_VISIBILITY long long abs(long long __x) _NOEXCEPT {return llabs(__x);}
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-
-inline _LIBCPP_INLINE_VISIBILITY  ldiv_t div(     long __x,      long __y) _NOEXCEPT {return  ldiv(__x, __y);}
-#ifndef _LIBCPP_HAS_NO_LONG_LONG
-inline _LIBCPP_INLINE_VISIBILITY lldiv_t div(long long __x, long long __y) _NOEXCEPT {return lldiv(__x, __y);}
-#endif // _LIBCPP_HAS_NO_LONG_LONG
-#endif // _LIBCPP_MSVCRT / __sun__ / _AIX
-
-}  // extern "C++"
-
-#endif  // __cplusplus
-
-#endif  // _LIBCPP_STDLIB_H
diff --git a/lib/libcxx/include/streambuf b/lib/libcxx/include/streambuf
deleted file mode 100644
index dd293dc639b..00000000000
--- a/lib/libcxx/include/streambuf
+++ /dev/null
@@ -1,501 +0,0 @@
-// -*- C++ -*-
-//===------------------------- streambuf ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_STEAMBUF
-#define _LIBCPP_STEAMBUF
-
-/*
-    streambuf synopsis
-
-namespace std
-{
-
-template <class charT, class traits = char_traits<charT> >
-class basic_streambuf
-{
-public:
-    // types:
-    typedef charT char_type;
-    typedef traits traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    virtual ~basic_streambuf();
-
-    // 27.6.2.2.1 locales:
-    locale pubimbue(const locale& loc);
-    locale getloc() const;
-
-    // 27.6.2.2.2 buffer and positioning:
-    basic_streambuf* pubsetbuf(char_type* s, streamsize n);
-    pos_type pubseekoff(off_type off, ios_base::seekdir way,
-                        ios_base::openmode which = ios_base::in | ios_base::out);
-    pos_type pubseekpos(pos_type sp,
-                        ios_base::openmode which = ios_base::in | ios_base::out);
-    int pubsync();
-
-    // Get and put areas:
-    // 27.6.2.2.3 Get area:
-    streamsize in_avail();
-    int_type snextc();
-    int_type sbumpc();
-    int_type sgetc();
-    streamsize sgetn(char_type* s, streamsize n);
-
-    // 27.6.2.2.4 Putback:
-    int_type sputbackc(char_type c);
-    int_type sungetc();
-
-    // 27.6.2.2.5 Put area:
-    int_type sputc(char_type c);
-    streamsize sputn(const char_type* s, streamsize n);
-
-protected:
-    basic_streambuf();
-    basic_streambuf(const basic_streambuf& rhs);
-    basic_streambuf& operator=(const basic_streambuf& rhs);
-    void swap(basic_streambuf& rhs);
-
-    // 27.6.2.3.2 Get area:
-    char_type* eback() const;
-    char_type* gptr() const;
-    char_type* egptr() const;
-    void gbump(int n);
-    void setg(char_type* gbeg, char_type* gnext, char_type* gend);
-
-    // 27.6.2.3.3 Put area:
-    char_type* pbase() const;
-    char_type* pptr() const;
-    char_type* epptr() const;
-    void pbump(int n);
-    void setp(char_type* pbeg, char_type* pend);
-
-    // 27.6.2.4 virtual functions:
-    // 27.6.2.4.1 Locales:
-    virtual void imbue(const locale& loc);
-
-    // 27.6.2.4.2 Buffer management and positioning:
-    virtual basic_streambuf* setbuf(char_type* s, streamsize n);
-    virtual pos_type seekoff(off_type off, ios_base::seekdir way,
-                             ios_base::openmode which = ios_base::in | ios_base::out);
-    virtual pos_type seekpos(pos_type sp,
-                             ios_base::openmode which = ios_base::in | ios_base::out);
-    virtual int sync();
-
-    // 27.6.2.4.3 Get area:
-    virtual streamsize showmanyc();
-    virtual streamsize xsgetn(char_type* s, streamsize n);
-    virtual int_type underflow();
-    virtual int_type uflow();
-
-    // 27.6.2.4.4 Putback:
-    virtual int_type pbackfail(int_type c = traits_type::eof());
-
-    // 27.6.2.4.5 Put area:
-    virtual streamsize xsputn(const char_type* s, streamsize n);
-    virtual int_type overflow (int_type c = traits_type::eof());
-};
-
-}  // std
-
-*/
-
-#include <__config>
-#include <iosfwd>
-#include <ios>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _CharT, class _Traits>
-class _LIBCPP_TEMPLATE_VIS basic_streambuf
-{
-public:
-    // types:
-    typedef _CharT                         char_type;
-    typedef _Traits                        traits_type;
-    typedef typename traits_type::int_type int_type;
-    typedef typename traits_type::pos_type pos_type;
-    typedef typename traits_type::off_type off_type;
-
-    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
-                  "traits_type::char_type must be the same type as CharT");
-
-    virtual ~basic_streambuf();
-
-    // 27.6.2.2.1 locales:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    locale pubimbue(const locale& __loc) {
-        imbue(__loc);
-        locale __r = __loc_;
-        __loc_ = __loc;
-        return __r;
-    }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    locale getloc() const { return __loc_; }
-
-    // 27.6.2.2.2 buffer and positioning:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    basic_streambuf* pubsetbuf(char_type* __s, streamsize __n)
-    { return setbuf(__s, __n); }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    pos_type pubseekoff(off_type __off, ios_base::seekdir __way,
-                        ios_base::openmode __which = ios_base::in | ios_base::out)
-    { return seekoff(__off, __way, __which); }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    pos_type pubseekpos(pos_type __sp,
-                        ios_base::openmode __which = ios_base::in | ios_base::out)
-    { return seekpos(__sp, __which); }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    int pubsync() { return sync(); }
-
-    // Get and put areas:
-    // 27.6.2.2.3 Get area:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    streamsize in_avail() {
-        if (__ninp_ < __einp_)
-            return static_cast<streamsize>(__einp_ - __ninp_);
-        return showmanyc();
-    }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    int_type snextc() {
-        if (sbumpc() == traits_type::eof())
-            return traits_type::eof();
-        return sgetc();
-    }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    int_type sbumpc() {
-        if (__ninp_ == __einp_)
-            return uflow();
-        return traits_type::to_int_type(*__ninp_++);
-    }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    int_type sgetc() {
-        if (__ninp_ == __einp_)
-            return underflow();
-        return traits_type::to_int_type(*__ninp_);
-    }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    streamsize sgetn(char_type* __s, streamsize __n)
-    { return xsgetn(__s, __n); }
-
-    // 27.6.2.2.4 Putback:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    int_type sputbackc(char_type __c) {
-        if (__binp_ == __ninp_ || !traits_type::eq(__c, __ninp_[-1]))
-            return pbackfail(traits_type::to_int_type(__c));
-        return traits_type::to_int_type(*--__ninp_);
-    }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    int_type sungetc() {
-        if (__binp_ == __ninp_)
-          return pbackfail();
-        return traits_type::to_int_type(*--__ninp_);
-    }
-
-    // 27.6.2.2.5 Put area:
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    int_type sputc(char_type __c) {
-        if (__nout_ == __eout_)
-            return overflow(traits_type::to_int_type(__c));
-        *__nout_++ = __c;
-        return traits_type::to_int_type(__c);
-    }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    streamsize sputn(const char_type* __s, streamsize __n)
-    { return xsputn(__s, __n); }
-
-protected:
-    basic_streambuf();
-    basic_streambuf(const basic_streambuf& __rhs);
-    basic_streambuf& operator=(const basic_streambuf& __rhs);
-    void swap(basic_streambuf& __rhs);
-
-    // 27.6.2.3.2 Get area:
-    _LIBCPP_INLINE_VISIBILITY char_type* eback() const {return __binp_;}
-    _LIBCPP_INLINE_VISIBILITY char_type* gptr()  const {return __ninp_;}
-    _LIBCPP_INLINE_VISIBILITY char_type* egptr() const {return __einp_;}
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    void gbump(int __n) { __ninp_ += __n; }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    void setg(char_type* __gbeg, char_type* __gnext, char_type* __gend) {
-        __binp_ = __gbeg;
-        __ninp_ = __gnext;
-        __einp_ = __gend;
-    }
-
-    // 27.6.2.3.3 Put area:
-    _LIBCPP_INLINE_VISIBILITY char_type* pbase() const {return __bout_;}
-    _LIBCPP_INLINE_VISIBILITY char_type* pptr()  const {return __nout_;}
-    _LIBCPP_INLINE_VISIBILITY char_type* epptr() const {return __eout_;}
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    void pbump(int __n) { __nout_ += __n; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __pbump(streamsize __n) { __nout_ += __n; }
-
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    void setp(char_type* __pbeg, char_type* __pend) {
-        __bout_ = __nout_ = __pbeg;
-        __eout_ = __pend;
-    }
-
-    // 27.6.2.4 virtual functions:
-    // 27.6.2.4.1 Locales:
-    virtual void imbue(const locale& __loc);
-
-    // 27.6.2.4.2 Buffer management and positioning:
-    virtual basic_streambuf* setbuf(char_type* __s, streamsize __n);
-    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way,
-                             ios_base::openmode __which = ios_base::in | ios_base::out);
-    virtual pos_type seekpos(pos_type __sp,
-                             ios_base::openmode __which = ios_base::in | ios_base::out);
-    virtual int sync();
-
-    // 27.6.2.4.3 Get area:
-    virtual streamsize showmanyc();
-    virtual streamsize xsgetn(char_type* __s, streamsize __n);
-    virtual int_type underflow();
-    virtual int_type uflow();
-
-    // 27.6.2.4.4 Putback:
-    virtual int_type pbackfail(int_type __c = traits_type::eof());
-
-    // 27.6.2.4.5 Put area:
-    virtual streamsize xsputn(const char_type* __s, streamsize __n);
-    virtual int_type overflow(int_type __c = traits_type::eof());
-
-private:
-    locale __loc_;
-    char_type* __binp_;
-    char_type* __ninp_;
-    char_type* __einp_;
-    char_type* __bout_;
-    char_type* __nout_;
-    char_type* __eout_;
-};
-
-template <class _CharT, class _Traits>
-basic_streambuf<_CharT, _Traits>::~basic_streambuf()
-{
-}
-
-template <class _CharT, class _Traits>
-basic_streambuf<_CharT, _Traits>::basic_streambuf()
-    : __binp_(0),
-      __ninp_(0),
-      __einp_(0),
-      __bout_(0),
-      __nout_(0),
-      __eout_(0)
-{
-}
-
-template <class _CharT, class _Traits>
-basic_streambuf<_CharT, _Traits>::basic_streambuf(const basic_streambuf& __sb)
-    : __loc_(__sb.__loc_),
-      __binp_(__sb.__binp_),
-      __ninp_(__sb.__ninp_),
-      __einp_(__sb.__einp_),
-      __bout_(__sb.__bout_),
-      __nout_(__sb.__nout_),
-      __eout_(__sb.__eout_)
-{
-}
-
-template <class _CharT, class _Traits>
-basic_streambuf<_CharT, _Traits>&
-basic_streambuf<_CharT, _Traits>::operator=(const basic_streambuf& __sb)
-{
-    __loc_ = __sb.__loc_;
-    __binp_ = __sb.__binp_;
-    __ninp_ = __sb.__ninp_;
-    __einp_ = __sb.__einp_;
-    __bout_ = __sb.__bout_;
-    __nout_ = __sb.__nout_;
-    __eout_ = __sb.__eout_;
-    return *this;
-}
-
-template <class _CharT, class _Traits>
-void
-basic_streambuf<_CharT, _Traits>::swap(basic_streambuf& __sb)
-{
-    _VSTD::swap(__loc_, __sb.__loc_);
-    _VSTD::swap(__binp_, __sb.__binp_);
-    _VSTD::swap(__ninp_, __sb.__ninp_);
-    _VSTD::swap(__einp_, __sb.__einp_);
-    _VSTD::swap(__bout_, __sb.__bout_);
-    _VSTD::swap(__nout_, __sb.__nout_);
-    _VSTD::swap(__eout_, __sb.__eout_);
-}
-
-template <class _CharT, class _Traits>
-void
-basic_streambuf<_CharT, _Traits>::imbue(const locale&)
-{
-}
-
-template <class _CharT, class _Traits>
-basic_streambuf<_CharT, _Traits>*
-basic_streambuf<_CharT, _Traits>::setbuf(char_type*, streamsize)
-{
-    return this;
-}
-
-template <class _CharT, class _Traits>
-typename basic_streambuf<_CharT, _Traits>::pos_type
-basic_streambuf<_CharT, _Traits>::seekoff(off_type, ios_base::seekdir,
-                                          ios_base::openmode)
-{
-    return pos_type(off_type(-1));
-}
-
-template <class _CharT, class _Traits>
-typename basic_streambuf<_CharT, _Traits>::pos_type
-basic_streambuf<_CharT, _Traits>::seekpos(pos_type, ios_base::openmode)
-{
-    return pos_type(off_type(-1));
-}
-
-template <class _CharT, class _Traits>
-int
-basic_streambuf<_CharT, _Traits>::sync()
-{
-    return 0;
-}
-
-template <class _CharT, class _Traits>
-streamsize
-basic_streambuf<_CharT, _Traits>::showmanyc()
-{
-    return 0;
-}
-
-template <class _CharT, class _Traits>
-streamsize
-basic_streambuf<_CharT, _Traits>::xsgetn(char_type* __s, streamsize __n)
-{
-    const int_type __eof = traits_type::eof();
-    int_type __c;
-    streamsize __i = 0;
-    while(__i < __n)
-    {
-        if (__ninp_ < __einp_)
-        {
-            const streamsize __len = _VSTD::min(static_cast<streamsize>(INT_MAX),
-                                _VSTD::min(__einp_ - __ninp_, __n - __i));
-            traits_type::copy(__s, __ninp_, __len);
-            __s +=  __len;
-            __i +=  __len;
-            this->gbump(__len);
-        }
-        else if ((__c = uflow()) != __eof)
-        {
-            *__s = traits_type::to_char_type(__c);
-            ++__s;
-            ++__i;
-        }
-        else
-            break;
-    }
-    return __i;
-}
-
-template <class _CharT, class _Traits>
-typename basic_streambuf<_CharT, _Traits>::int_type
-basic_streambuf<_CharT, _Traits>::underflow()
-{
-    return traits_type::eof();
-}
-
-template <class _CharT, class _Traits>
-typename basic_streambuf<_CharT, _Traits>::int_type
-basic_streambuf<_CharT, _Traits>::uflow()
-{
-    if (underflow() == traits_type::eof())
-        return traits_type::eof();
-    return traits_type::to_int_type(*__ninp_++);
-}
-
-template <class _CharT, class _Traits>
-typename basic_streambuf<_CharT, _Traits>::int_type
-basic_streambuf<_CharT, _Traits>::pbackfail(int_type)
-{
-    return traits_type::eof();
-}
-
-template <class _CharT, class _Traits>
-streamsize
-basic_streambuf<_CharT, _Traits>::xsputn(const char_type* __s, streamsize __n)
-{
-    streamsize __i = 0;
-    int_type __eof = traits_type::eof();
-    while( __i < __n)
-    {
-        if (__nout_ >= __eout_)
-        {
-            if (overflow(traits_type::to_int_type(*__s)) == __eof)
-                break;
-            ++__s;
-            ++__i;
-        }
-        else
-        {
-            streamsize __chunk_size = _VSTD::min(__eout_ - __nout_, __n - __i);
-            traits_type::copy(__nout_, __s, __chunk_size);
-            __nout_ += __chunk_size;
-            __s     += __chunk_size;
-            __i     += __chunk_size;
-        }
-    }
-    return __i;
-}
-
-template <class _CharT, class _Traits>
-typename basic_streambuf<_CharT, _Traits>::int_type
-basic_streambuf<_CharT, _Traits>::overflow(int_type)
-{
-    return traits_type::eof();
-}
-
-#ifndef _LIBCPP_DO_NOT_ASSUME_STREAMS_EXPLICIT_INSTANTIATION_IN_DYLIB
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_streambuf<char>)
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_streambuf<wchar_t>)
-
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ios<char>)
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_ios<wchar_t>)
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_STEAMBUF
diff --git a/lib/libcxx/include/string b/lib/libcxx/include/string
deleted file mode 100644
index fb838d1e5dd..00000000000
--- a/lib/libcxx/include/string
+++ /dev/null
@@ -1,4380 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- string -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_STRING
-#define _LIBCPP_STRING
-
-/*
-    string synopsis
-
-namespace std
-{
-
-template <class stateT>
-class fpos
-{
-private:
-    stateT st;
-public:
-    fpos(streamoff = streamoff());
-
-    operator streamoff() const;
-
-    stateT state() const;
-    void state(stateT);
-
-    fpos& operator+=(streamoff);
-    fpos  operator+ (streamoff) const;
-    fpos& operator-=(streamoff);
-    fpos  operator- (streamoff) const;
-};
-
-template <class stateT> streamoff operator-(const fpos<stateT>& x, const fpos<stateT>& y);
-
-template <class stateT> bool operator==(const fpos<stateT>& x, const fpos<stateT>& y);
-template <class stateT> bool operator!=(const fpos<stateT>& x, const fpos<stateT>& y);
-
-template <class charT>
-struct char_traits
-{
-    typedef charT     char_type;
-    typedef ...       int_type;
-    typedef streamoff off_type;
-    typedef streampos pos_type;
-    typedef mbstate_t state_type;
-
-    static void assign(char_type& c1, const char_type& c2) noexcept;
-    static constexpr bool eq(char_type c1, char_type c2) noexcept;
-    static constexpr bool lt(char_type c1, char_type c2) noexcept;
-
-    static int              compare(const char_type* s1, const char_type* s2, size_t n);
-    static size_t           length(const char_type* s);
-    static const char_type* find(const char_type* s, size_t n, const char_type& a);
-    static char_type*       move(char_type* s1, const char_type* s2, size_t n);
-    static char_type*       copy(char_type* s1, const char_type* s2, size_t n);
-    static char_type*       assign(char_type* s, size_t n, char_type a);
-
-    static constexpr int_type  not_eof(int_type c) noexcept;
-    static constexpr char_type to_char_type(int_type c) noexcept;
-    static constexpr int_type  to_int_type(char_type c) noexcept;
-    static constexpr bool      eq_int_type(int_type c1, int_type c2) noexcept;
-    static constexpr int_type  eof() noexcept;
-};
-
-template <> struct char_traits<char>;
-template <> struct char_traits<wchar_t>;
-
-template<class charT, class traits = char_traits<charT>, class Allocator = allocator<charT> >
-class basic_string
-{
-public:
-// types:
-    typedef traits traits_type;
-    typedef typename traits_type::char_type value_type;
-    typedef Allocator allocator_type;
-    typedef typename allocator_type::size_type size_type;
-    typedef typename allocator_type::difference_type difference_type;
-    typedef typename allocator_type::reference reference;
-    typedef typename allocator_type::const_reference const_reference;
-    typedef typename allocator_type::pointer pointer;
-    typedef typename allocator_type::const_pointer const_pointer;
-    typedef implementation-defined iterator;
-    typedef implementation-defined const_iterator;
-    typedef std::reverse_iterator<iterator> reverse_iterator;
-    typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
-
-    static const size_type npos = -1;
-
-    basic_string()
-        noexcept(is_nothrow_default_constructible<allocator_type>::value);
-    explicit basic_string(const allocator_type& a);
-    basic_string(const basic_string& str);
-    basic_string(basic_string&& str)
-        noexcept(is_nothrow_move_constructible<allocator_type>::value);
-    basic_string(const basic_string& str, size_type pos,
-                 const allocator_type& a = allocator_type());
-    basic_string(const basic_string& str, size_type pos, size_type n,
-                 const Allocator& a = Allocator());
-    template<class T>
-        basic_string(const T& t, size_type pos, size_type n, const Allocator& a = Allocator()); // C++17
-    template <class T>
-        explicit basic_string(const T& t, const Allocator& a = Allocator()); // C++17
-    basic_string(const value_type* s, const allocator_type& a = allocator_type());
-    basic_string(const value_type* s, size_type n, const allocator_type& a = allocator_type());
-    basic_string(size_type n, value_type c, const allocator_type& a = allocator_type());
-    template<class InputIterator>
-        basic_string(InputIterator begin, InputIterator end,
-                     const allocator_type& a = allocator_type());
-    basic_string(initializer_list<value_type>, const Allocator& = Allocator());
-    basic_string(const basic_string&, const Allocator&);
-    basic_string(basic_string&&, const Allocator&);
-
-    ~basic_string();
-
-    operator basic_string_view<charT, traits>() const noexcept;
-
-    basic_string& operator=(const basic_string& str);
-    template <class T>
-        basic_string& operator=(const T& t); // C++17
-    basic_string& operator=(basic_string&& str)
-        noexcept(
-             allocator_type::propagate_on_container_move_assignment::value ||
-             allocator_type::is_always_equal::value ); // C++17
-    basic_string& operator=(const value_type* s);
-    basic_string& operator=(value_type c);
-    basic_string& operator=(initializer_list<value_type>);
-
-    iterator       begin() noexcept;
-    const_iterator begin() const noexcept;
-    iterator       end() noexcept;
-    const_iterator end() const noexcept;
-
-    reverse_iterator       rbegin() noexcept;
-    const_reverse_iterator rbegin() const noexcept;
-    reverse_iterator       rend() noexcept;
-    const_reverse_iterator rend() const noexcept;
-
-    const_iterator         cbegin() const noexcept;
-    const_iterator         cend() const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend() const noexcept;
-
-    size_type size() const noexcept;
-    size_type length() const noexcept;
-    size_type max_size() const noexcept;
-    size_type capacity() const noexcept;
-
-    void resize(size_type n, value_type c);
-    void resize(size_type n);
-
-    void reserve(size_type res_arg = 0);
-    void shrink_to_fit();
-    void clear() noexcept;
-    bool empty() const noexcept;
-
-    const_reference operator[](size_type pos) const;
-    reference       operator[](size_type pos);
-
-    const_reference at(size_type n) const;
-    reference       at(size_type n);
-
-    basic_string& operator+=(const basic_string& str);
-    template <class T>
-        basic_string& operator+=(const T& t);              // C++17
-    basic_string& operator+=(const value_type* s);
-    basic_string& operator+=(value_type c);
-    basic_string& operator+=(initializer_list<value_type>);
-
-    basic_string& append(const basic_string& str);
-    template <class T>
-        basic_string& append(const T& t);                 // C++17
-    basic_string& append(const basic_string& str, size_type pos, size_type n=npos); //C++14
-    template <class T>
-        basic_string& append(const T& t, size_type pos, size_type n=npos); // C++17
-    basic_string& append(const value_type* s, size_type n);
-    basic_string& append(const value_type* s);
-    basic_string& append(size_type n, value_type c);
-    template<class InputIterator>
-        basic_string& append(InputIterator first, InputIterator last);
-    basic_string& append(initializer_list<value_type>);
-
-    void push_back(value_type c);
-    void pop_back();
-    reference       front();
-    const_reference front() const;
-    reference       back();
-    const_reference back() const;
-
-    basic_string& assign(const basic_string& str);
-    template <class T>
-        basic_string& assign(const T& t);  // C++17
-    basic_string& assign(basic_string&& str);
-    basic_string& assign(const basic_string& str, size_type pos, size_type n=npos); // C++14
-    template <class T>
-        basic_string& assign(const T& t, size_type pos, size_type n=npos); // C++17
-    basic_string& assign(const value_type* s, size_type n);
-    basic_string& assign(const value_type* s);
-    basic_string& assign(size_type n, value_type c);
-    template<class InputIterator>
-        basic_string& assign(InputIterator first, InputIterator last);
-    basic_string& assign(initializer_list<value_type>);
-
-    basic_string& insert(size_type pos1, const basic_string& str);
-    template <class T>
-        basic_string& insert(size_type pos1, const T& t);
-    basic_string& insert(size_type pos1, const basic_string& str,
-                         size_type pos2, size_type n);
-    template <class T>
-        basic_string& insert(size_type pos1, const T& t, size_type pos2, size_type n); // C++17
-    basic_string& insert(size_type pos, const value_type* s, size_type n=npos); //C++14
-    basic_string& insert(size_type pos, const value_type* s);
-    basic_string& insert(size_type pos, size_type n, value_type c);
-    iterator      insert(const_iterator p, value_type c);
-    iterator      insert(const_iterator p, size_type n, value_type c);
-    template<class InputIterator>
-        iterator insert(const_iterator p, InputIterator first, InputIterator last);
-    iterator      insert(const_iterator p, initializer_list<value_type>);
-
-    basic_string& erase(size_type pos = 0, size_type n = npos);
-    iterator      erase(const_iterator position);
-    iterator      erase(const_iterator first, const_iterator last);
-
-    basic_string& replace(size_type pos1, size_type n1, const basic_string& str);
-    template <class T>
-    basic_string& replace(size_type pos1, size_type n1, const T& t);  // C++17
-    basic_string& replace(size_type pos1, size_type n1, const basic_string& str,
-                          size_type pos2, size_type n2=npos); // C++14
-    template <class T>
-        basic_string& replace(size_type pos1, size_type n1, const T& t,
-                              size_type pos2, size_type n); // C++17
-    basic_string& replace(size_type pos, size_type n1, const value_type* s, size_type n2);
-    basic_string& replace(size_type pos, size_type n1, const value_type* s);
-    basic_string& replace(size_type pos, size_type n1, size_type n2, value_type c);
-    basic_string& replace(const_iterator i1, const_iterator i2, const basic_string& str);
-    template <class T>
-        basic_string& replace(const_iterator i1, const_iterator i2, const T& t);  // C++17
-    basic_string& replace(const_iterator i1, const_iterator i2, const value_type* s, size_type n);
-    basic_string& replace(const_iterator i1, const_iterator i2, const value_type* s);
-    basic_string& replace(const_iterator i1, const_iterator i2, size_type n, value_type c);
-    template<class InputIterator>
-        basic_string& replace(const_iterator i1, const_iterator i2, InputIterator j1, InputIterator j2);
-    basic_string& replace(const_iterator i1, const_iterator i2, initializer_list<value_type>);
-
-    size_type copy(value_type* s, size_type n, size_type pos = 0) const;
-    basic_string substr(size_type pos = 0, size_type n = npos) const;
-
-    void swap(basic_string& str)
-        noexcept(allocator_traits<allocator_type>::propagate_on_container_swap::value ||
-                 allocator_traits<allocator_type>::is_always_equal::value);  // C++17
-
-    const value_type* c_str() const noexcept;
-    const value_type* data() const noexcept;
-          value_type* data()       noexcept;   // C++17
-
-    allocator_type get_allocator() const noexcept;
-
-    size_type find(const basic_string& str, size_type pos = 0) const noexcept;
-    template <class T>
-        size_type find(const T& t, size_type pos = 0) const;  // C++17
-    size_type find(const value_type* s, size_type pos, size_type n) const noexcept;
-    size_type find(const value_type* s, size_type pos = 0) const noexcept;
-    size_type find(value_type c, size_type pos = 0) const noexcept;
-
-    size_type rfind(const basic_string& str, size_type pos = npos) const noexcept;
-    template <class T>
-        size_type rfind(const T& t, size_type pos = npos) const;  // C++17
-    size_type rfind(const value_type* s, size_type pos, size_type n) const noexcept;
-    size_type rfind(const value_type* s, size_type pos = npos) const noexcept;
-    size_type rfind(value_type c, size_type pos = npos) const noexcept;
-
-    size_type find_first_of(const basic_string& str, size_type pos = 0) const noexcept;
-    template <class T>
-        size_type find_first_of(const T& t, size_type pos = 0) const; // C++17
-    size_type find_first_of(const value_type* s, size_type pos, size_type n) const noexcept;
-    size_type find_first_of(const value_type* s, size_type pos = 0) const noexcept;
-    size_type find_first_of(value_type c, size_type pos = 0) const noexcept;
-
-    size_type find_last_of(const basic_string& str, size_type pos = npos) const noexcept;
-    template <class T>
-        size_type find_last_of(const T& t, size_type pos = npos) const noexcept;  // C++17
-    size_type find_last_of(const value_type* s, size_type pos, size_type n) const noexcept;
-    size_type find_last_of(const value_type* s, size_type pos = npos) const noexcept;
-    size_type find_last_of(value_type c, size_type pos = npos) const noexcept;
-
-    size_type find_first_not_of(const basic_string& str, size_type pos = 0) const noexcept;
-    template <class T>
-        size_type find_first_not_of(const T& t, size_type pos = 0) const; // C++17
-    size_type find_first_not_of(const value_type* s, size_type pos, size_type n) const noexcept;
-    size_type find_first_not_of(const value_type* s, size_type pos = 0) const noexcept;
-    size_type find_first_not_of(value_type c, size_type pos = 0) const noexcept;
-
-    size_type find_last_not_of(const basic_string& str, size_type pos = npos) const noexcept;
-    template <class T>
-        size_type find_last_not_of(const T& t, size_type pos = npos) const; // C++17
-    size_type find_last_not_of(const value_type* s, size_type pos, size_type n) const noexcept;
-    size_type find_last_not_of(const value_type* s, size_type pos = npos) const noexcept;
-    size_type find_last_not_of(value_type c, size_type pos = npos) const noexcept;
-
-    int compare(const basic_string& str) const noexcept;
-    template <class T>
-        int compare(const T& t) const noexcept;  // C++17
-    int compare(size_type pos1, size_type n1, const basic_string& str) const;
-    template <class T>
-        int compare(size_type pos1, size_type n1, const T& t) const;  // C++17
-    int compare(size_type pos1, size_type n1, const basic_string& str,
-                size_type pos2, size_type n2=npos) const; // C++14
-    template <class T>
-        int compare(size_type pos1, size_type n1, const T& t,
-                    size_type pos2, size_type n2=npos) const; // C++17
-    int compare(const value_type* s) const noexcept;
-    int compare(size_type pos1, size_type n1, const value_type* s) const;
-    int compare(size_type pos1, size_type n1, const value_type* s, size_type n2) const;
-
-    bool starts_with(basic_string_view<charT, traits> sv) const noexcept; // C++2a
-    bool starts_with(charT c) const noexcept;                             // C++2a
-    bool starts_with(const charT* s) const;                               // C++2a
-    bool ends_with(basic_string_view<charT, traits> sv) const noexcept;   // C++2a
-    bool ends_with(charT c) const noexcept;                               // C++2a
-    bool ends_with(const charT* s) const;                                 // C++2a
-
-    bool __invariants() const;
-};
-
-template<class InputIterator,
-         class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
-basic_string(InputIterator, InputIterator, Allocator = Allocator())
-   -> basic_string<typename iterator_traits<InputIterator>::value_type,
-                  char_traits<typename iterator_traits<InputIterator>::value_type>,
-                  Allocator>;   // C++17
-
-template<class charT, class traits, class Allocator>
-basic_string<charT, traits, Allocator>
-operator+(const basic_string<charT, traits, Allocator>& lhs,
-          const basic_string<charT, traits, Allocator>& rhs);
-
-template<class charT, class traits, class Allocator>
-basic_string<charT, traits, Allocator>
-operator+(const charT* lhs , const basic_string<charT,traits,Allocator>&rhs);
-
-template<class charT, class traits, class Allocator>
-basic_string<charT, traits, Allocator>
-operator+(charT lhs, const basic_string<charT,traits,Allocator>& rhs);
-
-template<class charT, class traits, class Allocator>
-basic_string<charT, traits, Allocator>
-operator+(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs);
-
-template<class charT, class traits, class Allocator>
-basic_string<charT, traits, Allocator>
-operator+(const basic_string<charT, traits, Allocator>& lhs, charT rhs);
-
-template<class charT, class traits, class Allocator>
-bool operator==(const basic_string<charT, traits, Allocator>& lhs,
-                const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator==(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator==(const basic_string<charT,traits,Allocator>& lhs, const charT* rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator!=(const basic_string<charT,traits,Allocator>& lhs,
-                const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator!=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator!=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator< (const basic_string<charT, traits, Allocator>& lhs,
-                const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator< (const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator< (const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator> (const basic_string<charT, traits, Allocator>& lhs,
-                const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator> (const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator> (const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator<=(const basic_string<charT, traits, Allocator>& lhs,
-                const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator<=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator<=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator>=(const basic_string<charT, traits, Allocator>& lhs,
-                const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator>=(const basic_string<charT, traits, Allocator>& lhs, const charT* rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-bool operator>=(const charT* lhs, const basic_string<charT, traits, Allocator>& rhs) noexcept;
-
-template<class charT, class traits, class Allocator>
-void swap(basic_string<charT, traits, Allocator>& lhs,
-          basic_string<charT, traits, Allocator>& rhs)
-            noexcept(noexcept(lhs.swap(rhs)));
-
-template<class charT, class traits, class Allocator>
-basic_istream<charT, traits>&
-operator>>(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str);
-
-template<class charT, class traits, class Allocator>
-basic_ostream<charT, traits>&
-operator<<(basic_ostream<charT, traits>& os, const basic_string<charT, traits, Allocator>& str);
-
-template<class charT, class traits, class Allocator>
-basic_istream<charT, traits>&
-getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str,
-        charT delim);
-
-template<class charT, class traits, class Allocator>
-basic_istream<charT, traits>&
-getline(basic_istream<charT, traits>& is, basic_string<charT, traits, Allocator>& str);
-
-template<class charT, class traits, class Allocator, class U>
-void erase(basic_string<charT, traits, Allocator>& c, const U& value); // C++20
-template<class charT, class traits, class Allocator, class Predicate>
-void erase_if(basic_string<charT, traits, Allocator>& c, Predicate pred); // C++20
-
-typedef basic_string<char>    string;
-typedef basic_string<wchar_t> wstring;
-typedef basic_string<char16_t> u16string;
-typedef basic_string<char32_t> u32string;
-
-int                stoi  (const string& str, size_t* idx = 0, int base = 10);
-long               stol  (const string& str, size_t* idx = 0, int base = 10);
-unsigned long      stoul (const string& str, size_t* idx = 0, int base = 10);
-long long          stoll (const string& str, size_t* idx = 0, int base = 10);
-unsigned long long stoull(const string& str, size_t* idx = 0, int base = 10);
-
-float       stof (const string& str, size_t* idx = 0);
-double      stod (const string& str, size_t* idx = 0);
-long double stold(const string& str, size_t* idx = 0);
-
-string to_string(int val);
-string to_string(unsigned val);
-string to_string(long val);
-string to_string(unsigned long val);
-string to_string(long long val);
-string to_string(unsigned long long val);
-string to_string(float val);
-string to_string(double val);
-string to_string(long double val);
-
-int                stoi  (const wstring& str, size_t* idx = 0, int base = 10);
-long               stol  (const wstring& str, size_t* idx = 0, int base = 10);
-unsigned long      stoul (const wstring& str, size_t* idx = 0, int base = 10);
-long long          stoll (const wstring& str, size_t* idx = 0, int base = 10);
-unsigned long long stoull(const wstring& str, size_t* idx = 0, int base = 10);
-
-float       stof (const wstring& str, size_t* idx = 0);
-double      stod (const wstring& str, size_t* idx = 0);
-long double stold(const wstring& str, size_t* idx = 0);
-
-wstring to_wstring(int val);
-wstring to_wstring(unsigned val);
-wstring to_wstring(long val);
-wstring to_wstring(unsigned long val);
-wstring to_wstring(long long val);
-wstring to_wstring(unsigned long long val);
-wstring to_wstring(float val);
-wstring to_wstring(double val);
-wstring to_wstring(long double val);
-
-template <> struct hash<string>;
-template <> struct hash<u16string>;
-template <> struct hash<u32string>;
-template <> struct hash<wstring>;
-
-basic_string<char>     operator "" s( const char *str,     size_t len ); // C++14
-basic_string<wchar_t>  operator "" s( const wchar_t *str,  size_t len ); // C++14
-basic_string<char16_t> operator "" s( const char16_t *str, size_t len ); // C++14
-basic_string<char32_t> operator "" s( const char32_t *str, size_t len ); // C++14
-
-}  // std
-
-*/
-
-#include <__config>
-#include <string_view>
-#include <iosfwd>
-#include <cstring>
-#include <cstdio>  // For EOF.
-#include <cwchar>
-#include <algorithm>
-#include <iterator>
-#include <utility>
-#include <memory>
-#include <stdexcept>
-#include <type_traits>
-#include <initializer_list>
-#include <__functional_base>
-#include <version>
-#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
-#include <cstdint>
-#endif
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// fpos
-
-template <class _StateT>
-class _LIBCPP_TEMPLATE_VIS fpos
-{
-private:
-    _StateT __st_;
-    streamoff __off_;
-public:
-    _LIBCPP_INLINE_VISIBILITY fpos(streamoff __off = streamoff()) : __st_(), __off_(__off) {}
-
-    _LIBCPP_INLINE_VISIBILITY operator streamoff() const {return __off_;}
-
-    _LIBCPP_INLINE_VISIBILITY _StateT state() const {return __st_;}
-    _LIBCPP_INLINE_VISIBILITY void state(_StateT __st) {__st_ = __st;}
-
-    _LIBCPP_INLINE_VISIBILITY fpos& operator+=(streamoff __off) {__off_ += __off; return *this;}
-    _LIBCPP_INLINE_VISIBILITY fpos  operator+ (streamoff __off) const {fpos __t(*this); __t += __off; return __t;}
-    _LIBCPP_INLINE_VISIBILITY fpos& operator-=(streamoff __off) {__off_ -= __off; return *this;}
-    _LIBCPP_INLINE_VISIBILITY fpos  operator- (streamoff __off) const {fpos __t(*this); __t -= __off; return __t;}
-};
-
-template <class _StateT>
-inline _LIBCPP_INLINE_VISIBILITY
-streamoff operator-(const fpos<_StateT>& __x, const fpos<_StateT>& __y)
-    {return streamoff(__x) - streamoff(__y);}
-
-template <class _StateT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(const fpos<_StateT>& __x, const fpos<_StateT>& __y)
-    {return streamoff(__x) == streamoff(__y);}
-
-template <class _StateT>
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(const fpos<_StateT>& __x, const fpos<_StateT>& __y)
-    {return streamoff(__x) != streamoff(__y);}
-
-// basic_string
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const basic_string<_CharT, _Traits, _Allocator>& __x,
-          const basic_string<_CharT, _Traits, _Allocator>& __y);
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const _CharT* __x, const basic_string<_CharT,_Traits,_Allocator>& __y);
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-operator+(_CharT __x, const basic_string<_CharT,_Traits,_Allocator>& __y);
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const basic_string<_CharT, _Traits, _Allocator>& __x, const _CharT* __y);
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const basic_string<_CharT, _Traits, _Allocator>& __x, _CharT __y);
-
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS string operator+<char, char_traits<char>, allocator<char> >(char const*, string const&))
-
-template <bool>
-class _LIBCPP_TEMPLATE_VIS __basic_string_common
-{
-protected:
-    _LIBCPP_NORETURN void __throw_length_error() const;
-    _LIBCPP_NORETURN void __throw_out_of_range() const;
-};
-
-template <bool __b>
-void
-__basic_string_common<__b>::__throw_length_error() const
-{
-    _VSTD::__throw_length_error("basic_string");
-}
-
-template <bool __b>
-void
-__basic_string_common<__b>::__throw_out_of_range() const
-{
-    _VSTD::__throw_out_of_range("basic_string");
-}
-
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __basic_string_common<true>)
-
-#ifdef _LIBCPP_NO_EXCEPTIONS
-template <class _Iter>
-struct __libcpp_string_gets_noexcept_iterator_impl : public true_type {};
-#elif defined(_LIBCPP_HAS_NO_NOEXCEPT)
-template <class _Iter>
-struct __libcpp_string_gets_noexcept_iterator_impl : public false_type {};
-#else
-template <class _Iter, bool = __is_forward_iterator<_Iter>::value>
-struct __libcpp_string_gets_noexcept_iterator_impl : public _LIBCPP_BOOL_CONSTANT((
-    noexcept(++(declval<_Iter&>())) && 
-    is_nothrow_assignable<_Iter&, _Iter>::value && 
-    noexcept(declval<_Iter>() == declval<_Iter>()) && 
-    noexcept(*declval<_Iter>())
-)) {};
-
-template <class _Iter> 
-struct __libcpp_string_gets_noexcept_iterator_impl<_Iter, false> : public false_type {};
-#endif
-
-
-template <class _Iter>
-struct __libcpp_string_gets_noexcept_iterator
-    : public _LIBCPP_BOOL_CONSTANT(__libcpp_is_trivial_iterator<_Iter>::value || __libcpp_string_gets_noexcept_iterator_impl<_Iter>::value) {};
-
-template <class _CharT, class _Traits, class _Tp>
-struct __can_be_converted_to_string_view : public _LIBCPP_BOOL_CONSTANT(
-    ( is_convertible<const _Tp&, basic_string_view<_CharT, _Traits> >::value &&
-     !is_convertible<const _Tp&, const _CharT*>::value)) {};
-
-#ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-
-template <class _CharT, size_t = sizeof(_CharT)>
-struct __padding
-{
-    unsigned char __xx[sizeof(_CharT)-1];
-};
-
-template <class _CharT>
-struct __padding<_CharT, 1>
-{
-};
-
-#endif  // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-
-template<class _CharT, class _Traits, class _Allocator>
-class _LIBCPP_TEMPLATE_VIS basic_string
-    : private __basic_string_common<true>
-{
-public:
-    typedef basic_string                                 __self;
-    typedef basic_string_view<_CharT, _Traits>           __self_view;
-    typedef _Traits                                      traits_type;
-    typedef _CharT                                       value_type;
-    typedef _Allocator                                   allocator_type;
-    typedef allocator_traits<allocator_type>             __alloc_traits;
-    typedef typename __alloc_traits::size_type           size_type;
-    typedef typename __alloc_traits::difference_type     difference_type;
-    typedef value_type&                                  reference;
-    typedef const value_type&                            const_reference;
-    typedef typename __alloc_traits::pointer             pointer;
-    typedef typename __alloc_traits::const_pointer       const_pointer;
-
-    static_assert((!is_array<value_type>::value), "Character type of basic_string must not be an array");
-    static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string must be standard-layout");
-    static_assert(( is_trivial<value_type>::value), "Character type of basic_string must be trivial");
-    static_assert(( is_same<_CharT, typename traits_type::char_type>::value),
-                  "traits_type::char_type must be the same type as CharT");
-    static_assert(( is_same<typename allocator_type::value_type, value_type>::value),
-                  "Allocator::value_type must be same type as value_type");
-
-#if defined(_LIBCPP_RAW_ITERATORS)
-    typedef pointer                                      iterator;
-    typedef const_pointer                                const_iterator;
-#else  // defined(_LIBCPP_RAW_ITERATORS)
-    typedef __wrap_iter<pointer>                         iterator;
-    typedef __wrap_iter<const_pointer>                   const_iterator;
-#endif  // defined(_LIBCPP_RAW_ITERATORS)
-    typedef _VSTD::reverse_iterator<iterator>             reverse_iterator;
-    typedef _VSTD::reverse_iterator<const_iterator>       const_reverse_iterator;
-
-private:
-
-#ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-
-    struct __long
-    {
-        pointer   __data_;
-        size_type __size_;
-        size_type __cap_;
-    };
-
-#ifdef _LIBCPP_BIG_ENDIAN
-    static const size_type __short_mask = 0x01;
-    static const size_type __long_mask  = 0x1ul;
-#else  // _LIBCPP_BIG_ENDIAN
-    static const size_type __short_mask = 0x80;
-    static const size_type __long_mask  = ~(size_type(~0) >> 1);
-#endif  // _LIBCPP_BIG_ENDIAN
-
-    enum {__min_cap = (sizeof(__long) - 1)/sizeof(value_type) > 2 ?
-                      (sizeof(__long) - 1)/sizeof(value_type) : 2};
-
-    struct __short
-    {
-        value_type __data_[__min_cap];
-        struct
-            : __padding<value_type>
-        {
-            unsigned char __size_;
-        };
-    };
-
-#else
-
-    struct __long
-    {
-        size_type __cap_;
-        size_type __size_;
-        pointer   __data_;
-    };
-
-#ifdef _LIBCPP_BIG_ENDIAN
-    static const size_type __short_mask = 0x80;
-    static const size_type __long_mask  = ~(size_type(~0) >> 1);
-#else  // _LIBCPP_BIG_ENDIAN
-    static const size_type __short_mask = 0x01;
-    static const size_type __long_mask  = 0x1ul;
-#endif  // _LIBCPP_BIG_ENDIAN
-
-    enum {__min_cap = (sizeof(__long) - 1)/sizeof(value_type) > 2 ?
-                      (sizeof(__long) - 1)/sizeof(value_type) : 2};
-
-    struct __short
-    {
-        union
-        {
-            unsigned char __size_;
-            value_type __lx;
-        };
-        value_type __data_[__min_cap];
-    };
-
-#endif  // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-
-    union __ulx{__long __lx; __short __lxx;};
-
-    enum {__n_words = sizeof(__ulx) / sizeof(size_type)};
-
-    struct __raw
-    {
-        size_type __words[__n_words];
-    };
-
-    struct __rep
-    {
-        union
-        {
-            __long  __l;
-            __short __s;
-            __raw   __r;
-        };
-    };
-
-    __compressed_pair<__rep, allocator_type> __r_;
-
-public:
-    static const size_type npos = -1;
-
-    _LIBCPP_INLINE_VISIBILITY basic_string()
-        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
-
-    _LIBCPP_INLINE_VISIBILITY explicit basic_string(const allocator_type& __a)
-#if _LIBCPP_STD_VER <= 14
-        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value);
-#else
-        _NOEXCEPT;
-#endif
-
-    basic_string(const basic_string& __str);
-    basic_string(const basic_string& __str, const allocator_type& __a);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string(basic_string&& __str)
-#if _LIBCPP_STD_VER <= 14
-        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
-#else
-        _NOEXCEPT;
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string(basic_string&& __str, const allocator_type& __a);
-#endif  // _LIBCPP_CXX03_LANG
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-    template <class = typename enable_if<__is_allocator<_Allocator>::value, nullptr_t>::type>
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string(const _CharT* __s) {
-      _LIBCPP_ASSERT(__s != nullptr, "basic_string(const char*) detected nullptr");
-      __init(__s, traits_type::length(__s));
-#   if _LIBCPP_DEBUG_LEVEL >= 2
-      __get_db()->__insert_c(this);
-#   endif
-    }
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-    template <class = typename enable_if<__is_allocator<_Allocator>::value, nullptr_t>::type>
-#endif
-        _LIBCPP_INLINE_VISIBILITY
-        basic_string(const _CharT* __s, const _Allocator& __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string(const _CharT* __s, size_type __n);
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string(const _CharT* __s, size_type __n, const _Allocator& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string(size_type __n, _CharT __c);
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-    template <class = typename enable_if<__is_allocator<_Allocator>::value, nullptr_t>::type>
-#endif
-        _LIBCPP_INLINE_VISIBILITY
-        basic_string(size_type __n, _CharT __c, const _Allocator& __a);
-
-    basic_string(const basic_string& __str, size_type __pos, size_type __n,
-                 const _Allocator& __a = _Allocator());
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string(const basic_string& __str, size_type __pos,
-                 const _Allocator& __a = _Allocator());
-
-    template<class _Tp, class = typename enable_if<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value, void>::type>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        basic_string(const _Tp& __t, size_type __pos, size_type __n,
-                              const allocator_type& __a = allocator_type());
-
-    template<class _Tp, class = typename enable_if<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value, void>::type>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        explicit basic_string(const _Tp& __t);
-
-    template<class _Tp, class = typename enable_if<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value, void>::type>
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        explicit basic_string(const _Tp& __t, const allocator_type& __a);
-
-    template<class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        basic_string(_InputIterator __first, _InputIterator __last);
-    template<class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        basic_string(_InputIterator __first, _InputIterator __last, const allocator_type& __a);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string(initializer_list<_CharT> __il);
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string(initializer_list<_CharT> __il, const _Allocator& __a);
-#endif  // _LIBCPP_CXX03_LANG
-
-    inline ~basic_string();
-
-    _LIBCPP_INLINE_VISIBILITY
-    operator __self_view() const _NOEXCEPT { return __self_view(data(), size()); }
-
-    basic_string& operator=(const basic_string& __str);
-
-    template <class _Tp, class = typename enable_if<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value, void>::type>
-    basic_string& operator=(const _Tp& __t)
-        {__self_view __sv = __t; return assign(__sv);}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& operator=(basic_string&& __str)
-        _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
-     _LIBCPP_INLINE_VISIBILITY
-    basic_string& operator=(initializer_list<value_type> __il) {return assign(__il.begin(), __il.size());}
-#endif
-    _LIBCPP_INLINE_VISIBILITY basic_string& operator=(const value_type* __s) {return assign(__s);}
-    basic_string& operator=(value_type __c);
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    iterator begin() _NOEXCEPT
-        {return iterator(this, __get_pointer());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT
-        {return const_iterator(this, __get_pointer());}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator end() _NOEXCEPT
-        {return iterator(this, __get_pointer() + size());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT
-        {return const_iterator(this, __get_pointer() + size());}
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    iterator begin() _NOEXCEPT
-        {return iterator(__get_pointer());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT
-        {return const_iterator(__get_pointer());}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator end() _NOEXCEPT
-        {return iterator(__get_pointer() + size());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end() const _NOEXCEPT
-        {return const_iterator(__get_pointer() + size());}
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator rbegin() _NOEXCEPT
-        {return reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin() const _NOEXCEPT
-        {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator rend() _NOEXCEPT
-        {return reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend() const _NOEXCEPT
-        {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT
-        {return begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend() const _NOEXCEPT
-        {return end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT
-        {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend() const _NOEXCEPT
-        {return rend();}
-
-    _LIBCPP_INLINE_VISIBILITY size_type size() const _NOEXCEPT
-        {return __is_long() ? __get_long_size() : __get_short_size();}
-    _LIBCPP_INLINE_VISIBILITY size_type length() const _NOEXCEPT {return size();}
-    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY size_type capacity() const _NOEXCEPT
-        {return (__is_long() ? __get_long_cap()
-                             : static_cast<size_type>(__min_cap)) - 1;}
-
-    void resize(size_type __n, value_type __c);
-    _LIBCPP_INLINE_VISIBILITY void resize(size_type __n) {resize(__n, value_type());}
-
-    void reserve(size_type __res_arg);
-    _LIBCPP_INLINE_VISIBILITY void __resize_default_init(size_type __n);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void reserve() _NOEXCEPT {reserve(0);}
-    _LIBCPP_INLINE_VISIBILITY
-    void shrink_to_fit() _NOEXCEPT {reserve();}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT;
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT {return size() == 0;}
-
-    _LIBCPP_INLINE_VISIBILITY const_reference operator[](size_type __pos) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY reference       operator[](size_type __pos)       _NOEXCEPT;
-
-    const_reference at(size_type __n) const;
-    reference       at(size_type __n);
-
-    _LIBCPP_INLINE_VISIBILITY basic_string& operator+=(const basic_string& __str) {return append(__str);}
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                                            operator+=(const _Tp& __t)            {__self_view __sv = __t; return append(__sv);}
-    _LIBCPP_INLINE_VISIBILITY basic_string& operator+=(const value_type* __s)     {return append(__s);}
-    _LIBCPP_INLINE_VISIBILITY basic_string& operator+=(value_type __c)            {push_back(__c); return *this;}
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY basic_string& operator+=(initializer_list<value_type> __il) {return append(__il);}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& append(const basic_string& __str);
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                  append(const _Tp& __t) { __self_view __sv = __t; return append(__sv.data(), __sv.size()); }
-    basic_string& append(const basic_string& __str, size_type __pos, size_type __n=npos);
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                  append(const _Tp& __t, size_type __pos, size_type __n=npos);
-    basic_string& append(const value_type* __s, size_type __n);
-    basic_string& append(const value_type* __s);
-    basic_string& append(size_type __n, value_type __c);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __append_default_init(size_type __n);
-
-    template <class _ForwardIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    basic_string& __append_forward_unsafe(_ForwardIterator, _ForwardIterator);
-    template<class _InputIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __is_exactly_input_iterator<_InputIterator>::value
-                || !__libcpp_string_gets_noexcept_iterator<_InputIterator>::value,
-            basic_string&
-        >::type
-    _LIBCPP_INLINE_VISIBILITY
-    append(_InputIterator __first, _InputIterator __last) {
-      const basic_string __temp (__first, __last, __alloc());
-      append(__temp.data(), __temp.size());
-      return *this;
-    }
-    template<class _ForwardIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value
-                && __libcpp_string_gets_noexcept_iterator<_ForwardIterator>::value,
-            basic_string&
-        >::type
-    _LIBCPP_INLINE_VISIBILITY
-    append(_ForwardIterator __first, _ForwardIterator __last) {
-      return __append_forward_unsafe(__first, __last);
-    }
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& append(initializer_list<value_type> __il) {return append(__il.begin(), __il.size());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    void push_back(value_type __c);
-    _LIBCPP_INLINE_VISIBILITY
-    void pop_back();
-    _LIBCPP_INLINE_VISIBILITY reference       front();
-    _LIBCPP_INLINE_VISIBILITY const_reference front() const;
-    _LIBCPP_INLINE_VISIBILITY reference       back();
-    _LIBCPP_INLINE_VISIBILITY const_reference back() const;
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                 assign(const _Tp & __t) { __self_view __sv = __t; return assign(__sv.data(), __sv.size()); }
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& assign(const basic_string& __str) { return *this = __str; }
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& assign(basic_string&& __str)
-        _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
-        {*this = _VSTD::move(__str); return *this;}
-#endif
-    basic_string& assign(const basic_string& __str, size_type __pos, size_type __n=npos);
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                  assign(const _Tp & __t, size_type __pos, size_type __n=npos);
-    basic_string& assign(const value_type* __s, size_type __n);
-    basic_string& assign(const value_type* __s);
-    basic_string& assign(size_type __n, value_type __c);
-    template<class _InputIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-           __is_exactly_input_iterator<_InputIterator>::value
-                || !__libcpp_string_gets_noexcept_iterator<_InputIterator>::value,
-            basic_string&
-        >::type
-        assign(_InputIterator __first, _InputIterator __last);
-    template<class _ForwardIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value
-                 && __libcpp_string_gets_noexcept_iterator<_ForwardIterator>::value,
-            basic_string&
-        >::type
-        assign(_ForwardIterator __first, _ForwardIterator __last);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& assign(initializer_list<value_type> __il) {return assign(__il.begin(), __il.size());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& insert(size_type __pos1, const basic_string& __str);
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                 insert(size_type __pos1, const _Tp& __t)
-    { __self_view __sv = __t; return insert(__pos1, __sv.data(), __sv.size()); }
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                  insert(size_type __pos1, const _Tp& __t, size_type __pos2, size_type __n=npos);
-    basic_string& insert(size_type __pos1, const basic_string& __str, size_type __pos2, size_type __n=npos);
-    basic_string& insert(size_type __pos, const value_type* __s, size_type __n);
-    basic_string& insert(size_type __pos, const value_type* __s);
-    basic_string& insert(size_type __pos, size_type __n, value_type __c);
-    iterator      insert(const_iterator __pos, value_type __c);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator      insert(const_iterator __pos, size_type __n, value_type __c);
-    template<class _InputIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-           __is_exactly_input_iterator<_InputIterator>::value
-                || !__libcpp_string_gets_noexcept_iterator<_InputIterator>::value,
-            iterator
-        >::type
-        insert(const_iterator __pos, _InputIterator __first, _InputIterator __last);
-    template<class _ForwardIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value
-                 && __libcpp_string_gets_noexcept_iterator<_ForwardIterator>::value,
-            iterator
-        >::type
-        insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __pos, initializer_list<value_type> __il)
-                    {return insert(__pos, __il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    basic_string& erase(size_type __pos = 0, size_type __n = npos);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator      erase(const_iterator __pos);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator      erase(const_iterator __first, const_iterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& replace(size_type __pos1, size_type __n1, const basic_string& __str);
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                  replace(size_type __pos1, size_type __n1, const _Tp& __t) { __self_view __sv = __t; return replace(__pos1, __n1, __sv.data(), __sv.size()); }
-    basic_string& replace(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2=npos);
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                  replace(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2=npos);
-    basic_string& replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2);
-    basic_string& replace(size_type __pos, size_type __n1, const value_type* __s);
-    basic_string& replace(size_type __pos, size_type __n1, size_type __n2, value_type __c);
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& replace(const_iterator __i1, const_iterator __i2, const basic_string& __str);
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            basic_string&
-        >::type
-                  replace(const_iterator __i1, const_iterator __i2, const _Tp& __t) { __self_view __sv = __t; return replace(__i1 - begin(), __i2 - __i1, __sv); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n);
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& replace(const_iterator __i1, const_iterator __i2, const value_type* __s);
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c);
-    template<class _InputIterator>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __is_input_iterator<_InputIterator>::value,
-            basic_string&
-        >::type
-        replace(const_iterator __i1, const_iterator __i2, _InputIterator __j1, _InputIterator __j2);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string& replace(const_iterator __i1, const_iterator __i2, initializer_list<value_type> __il)
-        {return replace(__i1, __i2, __il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    size_type copy(value_type* __s, size_type __n, size_type __pos = 0) const;
-    _LIBCPP_INLINE_VISIBILITY
-    basic_string substr(size_type __pos = 0, size_type __n = npos) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(basic_string& __str)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT_DEBUG;
-#else
-        _NOEXCEPT_DEBUG_(!__alloc_traits::propagate_on_container_swap::value ||
-                    __is_nothrow_swappable<allocator_type>::value);
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type* c_str() const _NOEXCEPT {return data();}
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type* data() const _NOEXCEPT  {return _VSTD::__to_raw_pointer(__get_pointer());}
-#if _LIBCPP_STD_VER > 14 || defined(_LIBCPP_BUILDING_LIBRARY)
-    _LIBCPP_INLINE_VISIBILITY
-    value_type* data()             _NOEXCEPT  {return _VSTD::__to_raw_pointer(__get_pointer());}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT {return __alloc();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT;
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            size_type
-        >::type
-              find(const _Tp& __t, size_type __pos = 0) const;
-    size_type find(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find(const value_type* __s, size_type __pos = 0) const _NOEXCEPT;
-    size_type find(value_type __c, size_type __pos = 0) const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type rfind(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT;
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            size_type
-        >::type
-              rfind(const _Tp& __t, size_type __pos = npos) const;
-    size_type rfind(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type rfind(const value_type* __s, size_type __pos = npos) const _NOEXCEPT;
-    size_type rfind(value_type __c, size_type __pos = npos) const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT;
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            size_type
-        >::type
-              find_first_of(const _Tp& __t, size_type __pos = 0) const;
-    size_type find_first_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_of(const value_type* __s, size_type __pos = 0) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_of(value_type __c, size_type __pos = 0) const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT;
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            size_type
-        >::type
-              find_last_of(const _Tp& __t, size_type __pos = npos) const;
-    size_type find_last_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_of(const value_type* __s, size_type __pos = npos) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_of(value_type __c, size_type __pos = npos) const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_not_of(const basic_string& __str, size_type __pos = 0) const _NOEXCEPT;
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            size_type
-        >::type
-              find_first_not_of(const _Tp &__t, size_type __pos = 0) const;
-    size_type find_first_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_not_of(const value_type* __s, size_type __pos = 0) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_not_of(value_type __c, size_type __pos = 0) const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_not_of(const basic_string& __str, size_type __pos = npos) const _NOEXCEPT;
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            size_type
-        >::type
-              find_last_not_of(const _Tp& __t, size_type __pos = npos) const;
-    size_type find_last_not_of(const value_type* __s, size_type __pos, size_type __n) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_not_of(const value_type* __s, size_type __pos = npos) const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_not_of(value_type __c, size_type __pos = npos) const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    int compare(const basic_string& __str) const _NOEXCEPT;
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            int
-        >::type
-        compare(const _Tp &__t) const;
-
-    template <class _Tp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            int
-        >::type
-         compare(size_type __pos1, size_type __n1, const _Tp& __t) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    int compare(size_type __pos1, size_type __n1, const basic_string& __str) const;
-    int compare(size_type __pos1, size_type __n1, const basic_string& __str, size_type __pos2, size_type __n2=npos) const;
-
-    template <class _Tp>
-    inline _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-            int
-        >::type
-        compare(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2=npos) const;
-    int compare(const value_type* __s) const _NOEXCEPT;
-    int compare(size_type __pos1, size_type __n1, const value_type* __s) const;
-    int compare(size_type __pos1, size_type __n1, const value_type* __s, size_type __n2) const;
-
-#if _LIBCPP_STD_VER > 17
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool starts_with(__self_view __sv) const _NOEXCEPT
-    { return __self_view(data(), size()).starts_with(__sv); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool starts_with(value_type __c) const _NOEXCEPT
-    { return !empty() && _Traits::eq(front(), __c); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool starts_with(const value_type* __s) const _NOEXCEPT
-    { return starts_with(__self_view(__s)); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool ends_with(__self_view __sv) const _NOEXCEPT
-    { return __self_view(data(), size()).ends_with( __sv); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool ends_with(value_type __c) const _NOEXCEPT
-    { return !empty() && _Traits::eq(back(), __c); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool ends_with(const value_type* __s) const _NOEXCEPT
-    { return ends_with(__self_view(__s)); }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY bool __invariants() const;
-
-    _LIBCPP_INLINE_VISIBILITY void __clear_and_shrink() _NOEXCEPT;
-    
-    _LIBCPP_INLINE_VISIBILITY
-    bool __is_long() const _NOEXCEPT
-        {return bool(__r_.first().__s.__size_ & __short_mask);}
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    bool __dereferenceable(const const_iterator* __i) const;
-    bool __decrementable(const const_iterator* __i) const;
-    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
-    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type& __alloc() _NOEXCEPT
-        {return __r_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const allocator_type& __alloc() const _NOEXCEPT
-        {return __r_.second();}
-
-#ifdef _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __set_short_size(size_type __s) _NOEXCEPT
-#   ifdef _LIBCPP_BIG_ENDIAN
-        {__r_.first().__s.__size_ = (unsigned char)(__s << 1);}
-#   else
-        {__r_.first().__s.__size_ = (unsigned char)(__s);}
-#   endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type __get_short_size() const _NOEXCEPT
-#   ifdef _LIBCPP_BIG_ENDIAN
-        {return __r_.first().__s.__size_ >> 1;}
-#   else
-        {return __r_.first().__s.__size_;}
-#   endif
-
-#else  // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __set_short_size(size_type __s) _NOEXCEPT
-#   ifdef _LIBCPP_BIG_ENDIAN
-        {__r_.first().__s.__size_ = (unsigned char)(__s);}
-#   else
-        {__r_.first().__s.__size_ = (unsigned char)(__s << 1);}
-#   endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type __get_short_size() const _NOEXCEPT
-#   ifdef _LIBCPP_BIG_ENDIAN
-        {return __r_.first().__s.__size_;}
-#   else
-        {return __r_.first().__s.__size_ >> 1;}
-#   endif
-
-#endif  // _LIBCPP_ABI_ALTERNATE_STRING_LAYOUT
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __set_long_size(size_type __s) _NOEXCEPT
-        {__r_.first().__l.__size_ = __s;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type __get_long_size() const _NOEXCEPT
-        {return __r_.first().__l.__size_;}
-    _LIBCPP_INLINE_VISIBILITY
-    void __set_size(size_type __s) _NOEXCEPT
-        {if (__is_long()) __set_long_size(__s); else __set_short_size(__s);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __set_long_cap(size_type __s) _NOEXCEPT
-        {__r_.first().__l.__cap_  = __long_mask | __s;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type __get_long_cap() const _NOEXCEPT
-        {return __r_.first().__l.__cap_ & size_type(~__long_mask);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __set_long_pointer(pointer __p) _NOEXCEPT
-        {__r_.first().__l.__data_ = __p;}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer __get_long_pointer() _NOEXCEPT
-        {return __r_.first().__l.__data_;}
-    _LIBCPP_INLINE_VISIBILITY
-    const_pointer __get_long_pointer() const _NOEXCEPT
-        {return __r_.first().__l.__data_;}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer __get_short_pointer() _NOEXCEPT
-        {return pointer_traits<pointer>::pointer_to(__r_.first().__s.__data_[0]);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_pointer __get_short_pointer() const _NOEXCEPT
-        {return pointer_traits<const_pointer>::pointer_to(__r_.first().__s.__data_[0]);}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer __get_pointer() _NOEXCEPT
-        {return __is_long() ? __get_long_pointer() : __get_short_pointer();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_pointer __get_pointer() const _NOEXCEPT
-        {return __is_long() ? __get_long_pointer() : __get_short_pointer();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __zero() _NOEXCEPT
-        {
-            size_type (&__a)[__n_words] = __r_.first().__r.__words;
-            for (unsigned __i = 0; __i < __n_words; ++__i)
-                __a[__i] = 0;
-        }
-
-    template <size_type __a> static
-        _LIBCPP_INLINE_VISIBILITY
-        size_type __align_it(size_type __s) _NOEXCEPT
-            {return (__s + (__a-1)) & ~(__a-1);}
-    enum {__alignment = 16};
-    static _LIBCPP_INLINE_VISIBILITY
-    size_type __recommend(size_type __s) _NOEXCEPT
-        {
-        if (__s < __min_cap) return static_cast<size_type>(__min_cap) - 1;
-        size_type __guess = __align_it<sizeof(value_type) < __alignment ?
-                     __alignment/sizeof(value_type) : 1 > (__s+1) - 1;
-        if (__guess == __min_cap) ++__guess;
-        return __guess;
-        }
-
-    inline
-    void __init(const value_type* __s, size_type __sz, size_type __reserve);
-    inline
-    void __init(const value_type* __s, size_type __sz);
-    inline
-    void __init(size_type __n, value_type __c);
-
-    template <class _InputIterator>
-    inline
-    typename enable_if
-    <
-        __is_exactly_input_iterator<_InputIterator>::value,
-        void
-    >::type
-    __init(_InputIterator __first, _InputIterator __last);
-
-    template <class _ForwardIterator>
-    inline
-    typename enable_if
-    <
-        __is_forward_iterator<_ForwardIterator>::value,
-        void
-    >::type
-    __init(_ForwardIterator __first, _ForwardIterator __last);
-
-    void __grow_by(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
-                   size_type __n_copy,  size_type __n_del,     size_type __n_add = 0);
-    void __grow_by_and_replace(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
-                               size_type __n_copy,  size_type __n_del,
-                               size_type __n_add, const value_type* __p_new_stuff);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __erase_to_end(size_type __pos);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const basic_string& __str)
-        {__copy_assign_alloc(__str, integral_constant<bool,
-                      __alloc_traits::propagate_on_container_copy_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const basic_string& __str, true_type)
-        {
-            if (__alloc() == __str.__alloc())
-                __alloc() = __str.__alloc();
-            else
-            {
-                if (!__str.__is_long())
-                {
-                    __clear_and_shrink();
-                    __alloc() = __str.__alloc();
-                }
-                else
-                {
-                    allocator_type __a = __str.__alloc();
-                    pointer __p = __alloc_traits::allocate(__a, __str.__get_long_cap());
-                    __clear_and_shrink();
-                    __alloc() = _VSTD::move(__a);
-                    __set_long_pointer(__p);
-                    __set_long_cap(__str.__get_long_cap());
-                    __set_long_size(__str.size());
-                }
-            }
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const basic_string&, false_type) _NOEXCEPT
-        {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign(basic_string& __str, false_type)
-        _NOEXCEPT_(__alloc_traits::is_always_equal::value);
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign(basic_string& __str, true_type)
-#if _LIBCPP_STD_VER > 14
-        _NOEXCEPT;
-#else
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
-#endif
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void
-    __move_assign_alloc(basic_string& __str)
-        _NOEXCEPT_(
-            !__alloc_traits::propagate_on_container_move_assignment::value ||
-            is_nothrow_move_assignable<allocator_type>::value)
-    {__move_assign_alloc(__str, integral_constant<bool,
-                      __alloc_traits::propagate_on_container_move_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(basic_string& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-        {
-            __alloc() = _VSTD::move(__c.__alloc());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(basic_string&, false_type)
-        _NOEXCEPT
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY void __invalidate_all_iterators();
-    _LIBCPP_INLINE_VISIBILITY void __invalidate_iterators_past(size_type);
-
-    friend basic_string operator+<>(const basic_string&, const basic_string&);
-    friend basic_string operator+<>(const value_type*, const basic_string&);
-    friend basic_string operator+<>(value_type, const basic_string&);
-    friend basic_string operator+<>(const basic_string&, const value_type*);
-    friend basic_string operator+<>(const basic_string&, value_type);
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class _InputIterator,
-         class _CharT = typename iterator_traits<_InputIterator>::value_type,
-         class _Allocator = allocator<_CharT>,
-         class = typename enable_if<__is_input_iterator<_InputIterator>::value, void>::type,
-         class = typename enable_if<__is_allocator<_Allocator>::value, void>::type
-         >
-basic_string(_InputIterator, _InputIterator, _Allocator = _Allocator())
-  -> basic_string<_CharT, char_traits<_CharT>, _Allocator>;
-
-template<class _CharT,
-         class _Traits,
-         class _Allocator = allocator<_CharT>,
-         class = typename enable_if<__is_allocator<_Allocator>::value, void>::type
-         >
-explicit basic_string(basic_string_view<_CharT, _Traits>, const _Allocator& = _Allocator())
-  -> basic_string<_CharT, _Traits, _Allocator>;
-
-template<class _CharT,
-         class _Traits,
-         class _Allocator = allocator<_CharT>,
-         class = typename enable_if<__is_allocator<_Allocator>::value, void>::type,
-         class _Sz = typename allocator_traits<_Allocator>::size_type
-         >
-basic_string(basic_string_view<_CharT, _Traits>, _Sz, _Sz, const _Allocator& = _Allocator())
-  -> basic_string<_CharT, _Traits, _Allocator>;
-#endif
-
-                  
-template <class _CharT, class _Traits, class _Allocator>
-inline
-void
-basic_string<_CharT, _Traits, _Allocator>::__invalidate_all_iterators()
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__invalidate_all(this);
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-void
-basic_string<_CharT, _Traits, _Allocator>::__invalidate_iterators_past(size_type
-#if _LIBCPP_DEBUG_LEVEL >= 2
-                                                                        __pos
-#endif
-                                                                      )
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __c_node* __c = __get_db()->__find_c_and_lock(this);
-    if (__c)
-    {
-        const_pointer __new_last = __get_pointer() + __pos;
-        for (__i_node** __p = __c->end_; __p != __c->beg_; )
-        {
-            --__p;
-            const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_);
-            if (__i->base() > __new_last)
-            {
-                (*__p)->__c_ = nullptr;
-                if (--__c->end_ != __p)
-                    memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
-            }
-        }
-        __get_db()->unlock();
-    }
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string()
-    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __zero();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(const allocator_type& __a)
-#if _LIBCPP_STD_VER <= 14
-        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
-#else
-        _NOEXCEPT
-#endif
-: __r_(__second_tag(), __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __zero();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void basic_string<_CharT, _Traits, _Allocator>::__init(const value_type* __s,
-                                                       size_type __sz,
-                                                       size_type __reserve)
-{
-    if (__reserve > max_size())
-        this->__throw_length_error();
-    pointer __p;
-    if (__reserve < __min_cap)
-    {
-        __set_short_size(__sz);
-        __p = __get_short_pointer();
-    }
-    else
-    {
-        size_type __cap = __recommend(__reserve);
-        __p = __alloc_traits::allocate(__alloc(), __cap+1);
-        __set_long_pointer(__p);
-        __set_long_cap(__cap+1);
-        __set_long_size(__sz);
-    }
-    traits_type::copy(_VSTD::__to_raw_pointer(__p), __s, __sz);
-    traits_type::assign(__p[__sz], value_type());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_string<_CharT, _Traits, _Allocator>::__init(const value_type* __s, size_type __sz)
-{
-    if (__sz > max_size())
-        this->__throw_length_error();
-    pointer __p;
-    if (__sz < __min_cap)
-    {
-        __set_short_size(__sz);
-        __p = __get_short_pointer();
-    }
-    else
-    {
-        size_type __cap = __recommend(__sz);
-        __p = __alloc_traits::allocate(__alloc(), __cap+1);
-        __set_long_pointer(__p);
-        __set_long_cap(__cap+1);
-        __set_long_size(__sz);
-    }
-    traits_type::copy(_VSTD::__to_raw_pointer(__p), __s, __sz);
-    traits_type::assign(__p[__sz], value_type());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template <class>
-#endif
-basic_string<_CharT, _Traits, _Allocator>::basic_string(const _CharT* __s, const _Allocator& __a)
-    : __r_(__second_tag(), __a)
-{
-    _LIBCPP_ASSERT(__s != nullptr, "basic_string(const char*, allocator) detected nullptr");
-    __init(__s, traits_type::length(__s));
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(const _CharT* __s, size_type __n)
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "basic_string(const char*, n) detected nullptr");
-    __init(__s, __n);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(const _CharT* __s, size_type __n, const _Allocator& __a)
-    : __r_(__second_tag(), __a)
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "basic_string(const char*, n, allocator) detected nullptr");
-    __init(__s, __n);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str)
-    : __r_(__second_tag(), __alloc_traits::select_on_container_copy_construction(__str.__alloc()))
-{
-    if (!__str.__is_long())
-        __r_.first().__r = __str.__r_.first().__r;
-    else
-        __init(_VSTD::__to_raw_pointer(__str.__get_long_pointer()), __str.__get_long_size());
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>::basic_string(
-    const basic_string& __str, const allocator_type& __a)
-    : __r_(__second_tag(), __a)
-{
-    if (!__str.__is_long())
-        __r_.first().__r = __str.__r_.first().__r;
-    else
-        __init(_VSTD::__to_raw_pointer(__str.__get_long_pointer()), __str.__get_long_size());
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(basic_string&& __str)
-#if _LIBCPP_STD_VER <= 14
-        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
-#else
-        _NOEXCEPT
-#endif
-    : __r_(_VSTD::move(__str.__r_))
-{
-    __str.__zero();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-    if (__is_long())
-        __get_db()->swap(this, &__str);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(basic_string&& __str, const allocator_type& __a)
-    : __r_(__second_tag(), __a)
-{
-    if (__str.__is_long() && __a != __str.__alloc()) // copy, not move
-        __init(_VSTD::__to_raw_pointer(__str.__get_long_pointer()), __str.__get_long_size());
-    else
-    {
-        __r_.first().__r = __str.__r_.first().__r;
-        __str.__zero();
-    }
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-    if (__is_long())
-        __get_db()->swap(this, &__str);
-#endif
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_string<_CharT, _Traits, _Allocator>::__init(size_type __n, value_type __c)
-{
-    if (__n > max_size())
-        this->__throw_length_error();
-    pointer __p;
-    if (__n < __min_cap)
-    {
-        __set_short_size(__n);
-        __p = __get_short_pointer();
-    }
-    else
-    {
-        size_type __cap = __recommend(__n);
-        __p = __alloc_traits::allocate(__alloc(), __cap+1);
-        __set_long_pointer(__p);
-        __set_long_cap(__cap+1);
-        __set_long_size(__n);
-    }
-    traits_type::assign(_VSTD::__to_raw_pointer(__p), __n, __c);
-    traits_type::assign(__p[__n], value_type());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(size_type __n, _CharT __c)
-{
-    __init(__n, __c);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template <class>
-#endif
-basic_string<_CharT, _Traits, _Allocator>::basic_string(size_type __n, _CharT __c, const _Allocator& __a)
-    : __r_(__second_tag(), __a)
-{
-    __init(__n, __c);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str,
-                                                        size_type __pos, size_type __n,
-                                                        const _Allocator& __a)
-    : __r_(__second_tag(), __a)
-{
-    size_type __str_sz = __str.size();
-    if (__pos > __str_sz)
-        this->__throw_out_of_range();
-    __init(__str.data() + __pos, _VSTD::min(__n, __str_sz - __pos));
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(const basic_string& __str, size_type __pos,
-                                                        const _Allocator& __a)
-    : __r_(__second_tag(), __a)
-{
-    size_type __str_sz = __str.size();
-    if (__pos > __str_sz)
-        this->__throw_out_of_range();
-    __init(__str.data() + __pos, __str_sz - __pos);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp, class>
-basic_string<_CharT, _Traits, _Allocator>::basic_string(
-             const _Tp& __t, size_type __pos, size_type __n, const allocator_type& __a)
-    : __r_(__second_tag(), __a)
-{
-    __self_view __sv0 = __t;
-    __self_view __sv = __sv0.substr(__pos, __n);
-    __init(__sv.data(), __sv.size());
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp, class>
-basic_string<_CharT, _Traits, _Allocator>::basic_string(const _Tp & __t)
-{
-    __self_view __sv = __t;
-    __init(__sv.data(), __sv.size());
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp, class>
-basic_string<_CharT, _Traits, _Allocator>::basic_string(const _Tp & __t, const _Allocator& __a)
-    : __r_(__second_tag(), __a)
-{
-    __self_view __sv = __t;
-    __init(__sv.data(), __sv.size());
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _InputIterator>
-typename enable_if
-<
-    __is_exactly_input_iterator<_InputIterator>::value,
-    void
->::type
-basic_string<_CharT, _Traits, _Allocator>::__init(_InputIterator __first, _InputIterator __last)
-{
-    __zero();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    for (; __first != __last; ++__first)
-        push_back(*__first);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        if (__is_long())
-            __alloc_traits::deallocate(__alloc(), __get_long_pointer(), __get_long_cap());
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value,
-    void
->::type
-basic_string<_CharT, _Traits, _Allocator>::__init(_ForwardIterator __first, _ForwardIterator __last)
-{
-    size_type __sz = static_cast<size_type>(_VSTD::distance(__first, __last));
-    if (__sz > max_size())
-        this->__throw_length_error();
-    pointer __p;
-    if (__sz < __min_cap)
-    {
-        __set_short_size(__sz);
-        __p = __get_short_pointer();
-    }
-    else
-    {
-        size_type __cap = __recommend(__sz);
-        __p = __alloc_traits::allocate(__alloc(), __cap+1);
-        __set_long_pointer(__p);
-        __set_long_cap(__cap+1);
-        __set_long_size(__sz);
-    }
-    for (; __first != __last; ++__first, (void) ++__p)
-        traits_type::assign(*__p, *__first);
-    traits_type::assign(*__p, value_type());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template<class _InputIterator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last)
-{
-    __init(__first, __last);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template<class _InputIterator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(_InputIterator __first, _InputIterator __last,
-                                                        const allocator_type& __a)
-    : __r_(__second_tag(), __a)
-{
-    __init(__first, __last);
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>::basic_string(
-    initializer_list<_CharT> __il)
-{
-    __init(__il.begin(), __il.end());
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-
-basic_string<_CharT, _Traits, _Allocator>::basic_string(
-    initializer_list<_CharT> __il, const _Allocator& __a)
-    : __r_(__second_tag(), __a)
-{
-    __init(__il.begin(), __il.end());
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>::~basic_string()
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__erase_c(this);
-#endif
-    if (__is_long())
-        __alloc_traits::deallocate(__alloc(), __get_long_pointer(), __get_long_cap());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_string<_CharT, _Traits, _Allocator>::__grow_by_and_replace
-    (size_type __old_cap, size_type __delta_cap, size_type __old_sz,
-     size_type __n_copy,  size_type __n_del,     size_type __n_add, const value_type* __p_new_stuff)
-{
-    size_type __ms = max_size();
-    if (__delta_cap > __ms - __old_cap - 1)
-        this->__throw_length_error();
-    pointer __old_p = __get_pointer();
-    size_type __cap = __old_cap < __ms / 2 - __alignment ?
-                          __recommend(_VSTD::max(__old_cap + __delta_cap, 2 * __old_cap)) :
-                          __ms - 1;
-    pointer __p = __alloc_traits::allocate(__alloc(), __cap+1);
-    __invalidate_all_iterators();
-    if (__n_copy != 0)
-        traits_type::copy(_VSTD::__to_raw_pointer(__p),
-                          _VSTD::__to_raw_pointer(__old_p), __n_copy);
-    if (__n_add != 0)
-        traits_type::copy(_VSTD::__to_raw_pointer(__p) + __n_copy, __p_new_stuff, __n_add);
-    size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;
-    if (__sec_cp_sz != 0)
-        traits_type::copy(_VSTD::__to_raw_pointer(__p) + __n_copy + __n_add,
-                          _VSTD::__to_raw_pointer(__old_p) + __n_copy + __n_del, __sec_cp_sz);
-    if (__old_cap+1 != __min_cap)
-        __alloc_traits::deallocate(__alloc(), __old_p, __old_cap+1);
-    __set_long_pointer(__p);
-    __set_long_cap(__cap+1);
-    __old_sz = __n_copy + __n_add + __sec_cp_sz;
-    __set_long_size(__old_sz);
-    traits_type::assign(__p[__old_sz], value_type());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_string<_CharT, _Traits, _Allocator>::__grow_by(size_type __old_cap, size_type __delta_cap, size_type __old_sz,
-                                                     size_type __n_copy,  size_type __n_del,     size_type __n_add)
-{
-    size_type __ms = max_size();
-    if (__delta_cap > __ms - __old_cap)
-        this->__throw_length_error();
-    pointer __old_p = __get_pointer();
-    size_type __cap = __old_cap < __ms / 2 - __alignment ?
-                          __recommend(_VSTD::max(__old_cap + __delta_cap, 2 * __old_cap)) :
-                          __ms - 1;
-    pointer __p = __alloc_traits::allocate(__alloc(), __cap+1);
-    __invalidate_all_iterators();
-    if (__n_copy != 0)
-        traits_type::copy(_VSTD::__to_raw_pointer(__p),
-                          _VSTD::__to_raw_pointer(__old_p), __n_copy);
-    size_type __sec_cp_sz = __old_sz - __n_del - __n_copy;
-    if (__sec_cp_sz != 0)
-        traits_type::copy(_VSTD::__to_raw_pointer(__p) + __n_copy + __n_add,
-                          _VSTD::__to_raw_pointer(__old_p) + __n_copy + __n_del,
-                          __sec_cp_sz);
-    if (__old_cap+1 != __min_cap)
-        __alloc_traits::deallocate(__alloc(), __old_p, __old_cap+1);
-    __set_long_pointer(__p);
-    __set_long_cap(__cap+1);
-}
-
-// assign
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s, size_type __n)
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::assign received nullptr");
-    size_type __cap = capacity();
-    if (__cap >= __n)
-    {
-        value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
-        traits_type::move(__p, __s, __n);
-        traits_type::assign(__p[__n], value_type());
-        __set_size(__n);
-        __invalidate_iterators_past(__n);
-    }
-    else
-    {
-        size_type __sz = size();
-        __grow_by_and_replace(__cap, __n - __cap, __sz, 0, __sz, __n, __s);
-    }
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::assign(size_type __n, value_type __c)
-{
-    size_type __cap = capacity();
-    if (__cap < __n)
-    {
-        size_type __sz = size();
-        __grow_by(__cap, __n - __cap, __sz, 0, __sz);
-    }
-    else
-        __invalidate_iterators_past(__n);
-    value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
-    traits_type::assign(__p, __n, __c);
-    traits_type::assign(__p[__n], value_type());
-    __set_size(__n);
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::operator=(value_type __c)
-{
-    pointer __p;
-    if (__is_long())
-    {
-        __p = __get_long_pointer();
-        __set_long_size(1);
-    }
-    else
-    {
-        __p = __get_short_pointer();
-        __set_short_size(1);
-    }
-    traits_type::assign(*__p, __c);
-    traits_type::assign(*++__p, value_type());
-    __invalidate_iterators_past(1);
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::operator=(const basic_string& __str)
-{
-    if (this != &__str)
-    {
-        __copy_assign_alloc(__str);
-        assign(__str.data(), __str.size());
-    }
-    return *this;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-void
-basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, false_type)
-    _NOEXCEPT_(__alloc_traits::is_always_equal::value)
-{
-    if (__alloc() != __str.__alloc())
-        assign(__str);
-    else
-        __move_assign(__str, true_type());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-void
-basic_string<_CharT, _Traits, _Allocator>::__move_assign(basic_string& __str, true_type)
-#if _LIBCPP_STD_VER > 14
-    _NOEXCEPT
-#else
-    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-#endif
-{
-    __clear_and_shrink();
-    __r_.first() = __str.__r_.first();
-    __move_assign_alloc(__str);
-    __str.__zero();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::operator=(basic_string&& __str)
-    _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
-{
-    __move_assign(__str, integral_constant<bool,
-          __alloc_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
-#endif
-
-template <class _CharT, class _Traits, class _Allocator>
-template<class _InputIterator>
-typename enable_if
-<
-     __is_exactly_input_iterator <_InputIterator>::value
-          || !__libcpp_string_gets_noexcept_iterator<_InputIterator>::value,
-    basic_string<_CharT, _Traits, _Allocator>&
->::type
-basic_string<_CharT, _Traits, _Allocator>::assign(_InputIterator __first, _InputIterator __last)
-{
-    const basic_string __temp(__first, __last, __alloc());
-    assign(__temp.data(), __temp.size());
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template<class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value
-         && __libcpp_string_gets_noexcept_iterator<_ForwardIterator>::value,
-    basic_string<_CharT, _Traits, _Allocator>&
->::type
-basic_string<_CharT, _Traits, _Allocator>::assign(_ForwardIterator __first, _ForwardIterator __last)
-{
-    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
-    size_type __cap = capacity();
-    if (__cap < __n)
-    {
-        size_type __sz = size();
-        __grow_by(__cap, __n - __cap, __sz, 0, __sz);
-    }
-    else
-        __invalidate_iterators_past(__n);
-    pointer __p = __get_pointer();
-    for (; __first != __last; ++__first, ++__p)
-        traits_type::assign(*__p, *__first);
-    traits_type::assign(*__p, value_type());
-    __set_size(__n);
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::assign(const basic_string& __str, size_type __pos, size_type __n)
-{
-    size_type __sz = __str.size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    return assign(__str.data() + __pos, _VSTD::min(__n, __sz - __pos));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    basic_string<_CharT, _Traits, _Allocator>&
->::type
-basic_string<_CharT, _Traits, _Allocator>::assign(const _Tp & __t, size_type __pos, size_type __n)
-{
-    __self_view __sv = __t;
-    size_type __sz = __sv.size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    return assign(__sv.data() + __pos, _VSTD::min(__n, __sz - __pos));
-}
-
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s)
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::assign received nullptr");
-    return assign(__s, traits_type::length(__s));
-}
-
-// append
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s, size_type __n)
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::append received nullptr");
-    size_type __cap = capacity();
-    size_type __sz = size();
-    if (__cap - __sz >= __n)
-    {
-        if (__n)
-        {
-            value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
-            traits_type::copy(__p + __sz, __s, __n);
-            __sz += __n;
-            __set_size(__sz);
-            traits_type::assign(__p[__sz], value_type());
-        }
-    }
-    else
-        __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __sz, 0, __n, __s);
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::append(size_type __n, value_type __c)
-{
-    if (__n)
-    {
-        size_type __cap = capacity();
-        size_type __sz = size();
-        if (__cap - __sz < __n)
-            __grow_by(__cap, __sz + __n - __cap, __sz, __sz, 0);
-        pointer __p = __get_pointer();
-        traits_type::assign(_VSTD::__to_raw_pointer(__p) + __sz, __n, __c);
-        __sz += __n;
-        __set_size(__sz);
-        traits_type::assign(__p[__sz], value_type());
-    }
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline void
-basic_string<_CharT, _Traits, _Allocator>::__append_default_init(size_type __n)
-{
-    if (__n)
-    {
-        size_type __cap = capacity();
-        size_type __sz = size();
-        if (__cap - __sz < __n)
-            __grow_by(__cap, __sz + __n - __cap, __sz, __sz, 0);
-        pointer __p = __get_pointer();
-        __sz += __n;
-        __set_size(__sz);
-        traits_type::assign(__p[__sz], value_type());
-    }
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_string<_CharT, _Traits, _Allocator>::push_back(value_type __c)
-{
-    bool __is_short = !__is_long();
-    size_type __cap;
-    size_type __sz;
-    if (__is_short)
-    {
-        __cap = __min_cap - 1;
-        __sz = __get_short_size();
-    }
-    else
-    {
-        __cap = __get_long_cap() - 1;
-        __sz = __get_long_size();
-    }
-    if (__sz == __cap)
-    {
-        __grow_by(__cap, 1, __sz, __sz, 0);
-        __is_short = !__is_long();
-    }
-    pointer __p;
-    if (__is_short)
-    {
-        __p = __get_short_pointer() + __sz;
-        __set_short_size(__sz+1);
-    }
-    else
-    {
-        __p = __get_long_pointer() + __sz;
-        __set_long_size(__sz+1);
-    }
-    traits_type::assign(*__p, __c);
-    traits_type::assign(*++__p, value_type());
-}
-
-template <class _Tp>
-bool __ptr_in_range (const _Tp* __p, const _Tp* __first, const _Tp* __last)
-{
-    return __first <= __p && __p < __last;
-}
-
-template <class _Tp1, class _Tp2>
-bool __ptr_in_range (const _Tp1*, const _Tp2*, const _Tp2*)
-{
-    return false;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template<class _ForwardIterator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::__append_forward_unsafe(
-    _ForwardIterator __first, _ForwardIterator __last)
-{
-    static_assert(__is_forward_iterator<_ForwardIterator>::value,
-                  "function requires a ForwardIterator");
-    size_type __sz = size();
-    size_type __cap = capacity();
-    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
-    if (__n)
-    {
-        typedef typename iterator_traits<_ForwardIterator>::reference _CharRef;
-        _CharRef __tmp_ref = *__first;
-        if (__ptr_in_range(_VSTD::addressof(__tmp_ref), data(), data() + size()))
-        {
-            const basic_string __temp (__first, __last, __alloc());
-            append(__temp.data(), __temp.size());
-        }
-        else 
-        {
-            if (__cap - __sz < __n)
-                __grow_by(__cap, __sz + __n - __cap, __sz, __sz, 0);
-            pointer __p = __get_pointer() + __sz;
-            for (; __first != __last; ++__p, ++__first)
-                traits_type::assign(*__p, *__first);
-            traits_type::assign(*__p, value_type());
-            __set_size(__sz + __n);
-        }
-    }
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str)
-{
-    return append(__str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::append(const basic_string& __str, size_type __pos, size_type __n)
-{
-    size_type __sz = __str.size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    return append(__str.data() + __pos, _VSTD::min(__n, __sz - __pos));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-    typename enable_if
-    <
-        __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-        basic_string<_CharT, _Traits, _Allocator>&
-    >::type
-basic_string<_CharT, _Traits, _Allocator>::append(const _Tp & __t, size_type __pos, size_type __n)
-{
-    __self_view __sv = __t;
-    size_type __sz = __sv.size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    return append(__sv.data() + __pos, _VSTD::min(__n, __sz - __pos));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::append(const value_type* __s)
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::append received nullptr");
-    return append(__s, traits_type::length(__s));
-}
-
-// insert
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s, size_type __n)
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::insert received nullptr");
-    size_type __sz = size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    size_type __cap = capacity();
-    if (__cap - __sz >= __n)
-    {
-        if (__n)
-        {
-            value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
-            size_type __n_move = __sz - __pos;
-            if (__n_move != 0)
-            {
-                if (__p + __pos <= __s && __s < __p + __sz)
-                    __s += __n;
-                traits_type::move(__p + __pos + __n, __p + __pos, __n_move);
-            }
-            traits_type::move(__p + __pos, __s, __n);
-            __sz += __n;
-            __set_size(__sz);
-            traits_type::assign(__p[__sz], value_type());
-        }
-    }
-    else
-        __grow_by_and_replace(__cap, __sz + __n - __cap, __sz, __pos, 0, __n, __s);
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, size_type __n, value_type __c)
-{
-    size_type __sz = size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    if (__n)
-    {
-        size_type __cap = capacity();
-        value_type* __p;
-        if (__cap - __sz >= __n)
-        {
-            __p = _VSTD::__to_raw_pointer(__get_pointer());
-            size_type __n_move = __sz - __pos;
-            if (__n_move != 0)
-                traits_type::move(__p + __pos + __n, __p + __pos, __n_move);
-        }
-        else
-        {
-            __grow_by(__cap, __sz + __n - __cap, __sz, __pos, 0, __n);
-            __p = _VSTD::__to_raw_pointer(__get_long_pointer());
-        }
-        traits_type::assign(__p + __pos, __n, __c);
-        __sz += __n;
-        __set_size(__sz);
-        traits_type::assign(__p[__sz], value_type());
-    }
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template<class _InputIterator>
-typename enable_if
-<
-   __is_exactly_input_iterator<_InputIterator>::value
-        || !__libcpp_string_gets_noexcept_iterator<_InputIterator>::value,
-   typename basic_string<_CharT, _Traits, _Allocator>::iterator
->::type
-basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, _InputIterator __first, _InputIterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
-        "string::insert(iterator, range) called with an iterator not"
-        " referring to this string");
-#endif
-    const basic_string __temp(__first, __last, __alloc());
-    return insert(__pos, __temp.data(), __temp.data() + __temp.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template<class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value
-        && __libcpp_string_gets_noexcept_iterator<_ForwardIterator>::value,
-    typename basic_string<_CharT, _Traits, _Allocator>::iterator
->::type
-basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, _ForwardIterator __first, _ForwardIterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
-        "string::insert(iterator, range) called with an iterator not"
-        " referring to this string");
-#endif
-    size_type __ip = static_cast<size_type>(__pos - begin());
-    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
-    if (__n)
-    {
-        typedef typename iterator_traits<_ForwardIterator>::reference _CharRef;
-        _CharRef __tmp_char = *__first;
-        if (__ptr_in_range(_VSTD::addressof(__tmp_char), data(), data() + size()))
-        {
-            const basic_string __temp(__first, __last, __alloc());
-            return insert(__pos, __temp.data(), __temp.data() + __temp.size());
-        }
-
-        size_type __sz = size();
-        size_type __cap = capacity();
-        value_type* __p;
-        if (__cap - __sz >= __n)
-        {
-            __p = _VSTD::__to_raw_pointer(__get_pointer());
-            size_type __n_move = __sz - __ip;
-            if (__n_move != 0)
-                traits_type::move(__p + __ip + __n, __p + __ip, __n_move);
-        }
-        else
-        {
-            __grow_by(__cap, __sz + __n - __cap, __sz, __ip, 0, __n);
-            __p = _VSTD::__to_raw_pointer(__get_long_pointer());
-        }
-        __sz += __n;
-        __set_size(__sz);
-        traits_type::assign(__p[__sz], value_type());
-        for (__p += __ip; __first != __last; ++__p, ++__first)
-            traits_type::assign(*__p, *__first);
-    }
-    return begin() + __ip;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str)
-{
-    return insert(__pos1, __str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const basic_string& __str,
-                                                  size_type __pos2, size_type __n)
-{
-    size_type __str_sz = __str.size();
-    if (__pos2 > __str_sz)
-        this->__throw_out_of_range();
-    return insert(__pos1, __str.data() + __pos2, _VSTD::min(__n, __str_sz - __pos2));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    basic_string<_CharT, _Traits, _Allocator>&
->::type
-basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos1, const _Tp& __t,
-                                                  size_type __pos2, size_type __n)
-{
-    __self_view __sv = __t;
-    size_type __str_sz = __sv.size();
-    if (__pos2 > __str_sz)
-        this->__throw_out_of_range();
-    return insert(__pos1, __sv.data() + __pos2, _VSTD::min(__n, __str_sz - __pos2));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::insert(size_type __pos, const value_type* __s)
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::insert received nullptr");
-    return insert(__pos, __s, traits_type::length(__s));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::iterator
-basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, value_type __c)
-{
-    size_type __ip = static_cast<size_type>(__pos - begin());
-    size_type __sz = size();
-    size_type __cap = capacity();
-    value_type* __p;
-    if (__cap == __sz)
-    {
-        __grow_by(__cap, 1, __sz, __ip, 0, 1);
-        __p = _VSTD::__to_raw_pointer(__get_long_pointer());
-    }
-    else
-    {
-        __p = _VSTD::__to_raw_pointer(__get_pointer());
-        size_type __n_move = __sz - __ip;
-        if (__n_move != 0)
-            traits_type::move(__p + __ip + 1, __p + __ip, __n_move);
-    }
-    traits_type::assign(__p[__ip], __c);
-    traits_type::assign(__p[++__sz], value_type());
-    __set_size(__sz);
-    return begin() + static_cast<difference_type>(__ip);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::iterator
-basic_string<_CharT, _Traits, _Allocator>::insert(const_iterator __pos, size_type __n, value_type __c)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
-        "string::insert(iterator, n, value) called with an iterator not"
-        " referring to this string");
-#endif
-    difference_type __p = __pos - begin();
-    insert(static_cast<size_type>(__p), __n, __c);
-    return begin() + __p;
-}
-
-// replace
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s, size_type __n2)
-    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-{
-    _LIBCPP_ASSERT(__n2 == 0 || __s != nullptr, "string::replace received nullptr");
-    size_type __sz = size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    __n1 = _VSTD::min(__n1, __sz - __pos);
-    size_type __cap = capacity();
-    if (__cap - __sz + __n1 >= __n2)
-    {
-        value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
-        if (__n1 != __n2)
-        {
-            size_type __n_move = __sz - __pos - __n1;
-            if (__n_move != 0)
-            {
-                if (__n1 > __n2)
-                {
-                    traits_type::move(__p + __pos, __s, __n2);
-                    traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
-                    goto __finish;
-                }
-                if (__p + __pos < __s && __s < __p + __sz)
-                {
-                    if (__p + __pos + __n1 <= __s)
-                        __s += __n2 - __n1;
-                    else // __p + __pos < __s < __p + __pos + __n1
-                    {
-                        traits_type::move(__p + __pos, __s, __n1);
-                        __pos += __n1;
-                        __s += __n2;
-                        __n2 -= __n1;
-                        __n1 = 0;
-                    }
-                }
-                traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
-            }
-        }
-        traits_type::move(__p + __pos, __s, __n2);
-__finish:
-// __sz += __n2 - __n1; in this and the below function below can cause unsigned integer overflow,
-// but this is a safe operation, so we disable the check.
-        __sz += __n2 - __n1;
-        __set_size(__sz);
-        __invalidate_iterators_past(__sz);
-        traits_type::assign(__p[__sz], value_type());
-    }
-    else
-        __grow_by_and_replace(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2, __s);
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, size_type __n2, value_type __c)
-    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-{
-    size_type __sz = size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    __n1 = _VSTD::min(__n1, __sz - __pos);
-    size_type __cap = capacity();
-    value_type* __p;
-    if (__cap - __sz + __n1 >= __n2)
-    {
-        __p = _VSTD::__to_raw_pointer(__get_pointer());
-        if (__n1 != __n2)
-        {
-            size_type __n_move = __sz - __pos - __n1;
-            if (__n_move != 0)
-                traits_type::move(__p + __pos + __n2, __p + __pos + __n1, __n_move);
-        }
-    }
-    else
-    {
-        __grow_by(__cap, __sz - __n1 + __n2 - __cap, __sz, __pos, __n1, __n2);
-        __p = _VSTD::__to_raw_pointer(__get_long_pointer());
-    }
-    traits_type::assign(__p + __pos, __n2, __c);
-    __sz += __n2 - __n1;
-    __set_size(__sz);
-    __invalidate_iterators_past(__sz);
-    traits_type::assign(__p[__sz], value_type());
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template<class _InputIterator>
-typename enable_if
-<
-    __is_input_iterator<_InputIterator>::value,
-    basic_string<_CharT, _Traits, _Allocator>&
->::type
-basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2,
-                                                   _InputIterator __j1, _InputIterator __j2)
-{
-    const basic_string __temp(__j1, __j2, __alloc());
-    return this->replace(__i1, __i2, __temp);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str)
-{
-    return replace(__pos1, __n1, __str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const basic_string& __str,
-                                                   size_type __pos2, size_type __n2)
-{
-    size_type __str_sz = __str.size();
-    if (__pos2 > __str_sz)
-        this->__throw_out_of_range();
-    return replace(__pos1, __n1, __str.data() + __pos2, _VSTD::min(__n2, __str_sz - __pos2));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    basic_string<_CharT, _Traits, _Allocator>&
->::type
-basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos1, size_type __n1, const _Tp& __t,
-                                                   size_type __pos2, size_type __n2)
-{
-    __self_view __sv = __t;
-    size_type __str_sz = __sv.size();
-    if (__pos2 > __str_sz)
-        this->__throw_out_of_range();
-    return replace(__pos1, __n1, __sv.data() + __pos2, _VSTD::min(__n2, __str_sz - __pos2));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(size_type __pos, size_type __n1, const value_type* __s)
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::replace received nullptr");
-    return replace(__pos, __n1, __s, traits_type::length(__s));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const basic_string& __str)
-{
-    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1),
-                   __str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s, size_type __n)
-{
-    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s, __n);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, const value_type* __s)
-{
-    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __s);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::replace(const_iterator __i1, const_iterator __i2, size_type __n, value_type __c)
-{
-    return replace(static_cast<size_type>(__i1 - begin()), static_cast<size_type>(__i2 - __i1), __n, __c);
-}
-
-// erase
-
-template <class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>&
-basic_string<_CharT, _Traits, _Allocator>::erase(size_type __pos, size_type __n)
-{
-    size_type __sz = size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    if (__n)
-    {
-        value_type* __p = _VSTD::__to_raw_pointer(__get_pointer());
-        __n = _VSTD::min(__n, __sz - __pos);
-        size_type __n_move = __sz - __pos - __n;
-        if (__n_move != 0)
-            traits_type::move(__p + __pos, __p + __pos + __n, __n_move);
-        __sz -= __n;
-        __set_size(__sz);
-        __invalidate_iterators_past(__sz);
-        traits_type::assign(__p[__sz], value_type());
-    }
-    return *this;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::iterator
-basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __pos)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__pos) == this,
-        "string::erase(iterator) called with an iterator not"
-        " referring to this string");
-#endif
-    _LIBCPP_ASSERT(__pos != end(),
-        "string::erase(iterator) called with a non-dereferenceable iterator");
-    iterator __b = begin();
-    size_type __r = static_cast<size_type>(__pos - __b);
-    erase(__r, 1);
-    return __b + static_cast<difference_type>(__r);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::iterator
-basic_string<_CharT, _Traits, _Allocator>::erase(const_iterator __first, const_iterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
-        "string::erase(iterator,  iterator) called with an iterator not"
-        " referring to this string");
-#endif
-    _LIBCPP_ASSERT(__first <= __last, "string::erase(first, last) called with invalid range");
-    iterator __b = begin();
-    size_type __r = static_cast<size_type>(__first - __b);
-    erase(__r, static_cast<size_type>(__last - __first));
-    return __b + static_cast<difference_type>(__r);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-void
-basic_string<_CharT, _Traits, _Allocator>::pop_back()
-{
-    _LIBCPP_ASSERT(!empty(), "string::pop_back(): string is already empty");
-    size_type __sz;
-    if (__is_long())
-    {
-        __sz = __get_long_size() - 1;
-        __set_long_size(__sz);
-        traits_type::assign(*(__get_long_pointer() + __sz), value_type());
-    }
-    else
-    {
-        __sz = __get_short_size() - 1;
-        __set_short_size(__sz);
-        traits_type::assign(*(__get_short_pointer() + __sz), value_type());
-    }
-    __invalidate_iterators_past(__sz);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-void
-basic_string<_CharT, _Traits, _Allocator>::clear() _NOEXCEPT
-{
-    __invalidate_all_iterators();
-    if (__is_long())
-    {
-        traits_type::assign(*__get_long_pointer(), value_type());
-        __set_long_size(0);
-    }
-    else
-    {
-        traits_type::assign(*__get_short_pointer(), value_type());
-        __set_short_size(0);
-    }
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-void
-basic_string<_CharT, _Traits, _Allocator>::__erase_to_end(size_type __pos)
-{
-    if (__is_long())
-    {
-        traits_type::assign(*(__get_long_pointer() + __pos), value_type());
-        __set_long_size(__pos);
-    }
-    else
-    {
-        traits_type::assign(*(__get_short_pointer() + __pos), value_type());
-        __set_short_size(__pos);
-    }
-    __invalidate_iterators_past(__pos);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_string<_CharT, _Traits, _Allocator>::resize(size_type __n, value_type __c)
-{
-    size_type __sz = size();
-    if (__n > __sz)
-        append(__n - __sz, __c);
-    else
-        __erase_to_end(__n);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline void
-basic_string<_CharT, _Traits, _Allocator>::__resize_default_init(size_type __n)
-{
-    size_type __sz = size();
-    if (__n > __sz) {
-       __append_default_init(__n - __sz);
-    } else
-        __erase_to_end(__n);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::max_size() const _NOEXCEPT
-{
-    size_type __m = __alloc_traits::max_size(__alloc());
-#ifdef _LIBCPP_BIG_ENDIAN
-    return (__m <= ~__long_mask ? __m : __m/2) - __alignment;
-#else
-    return __m - __alignment;
-#endif
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-void
-basic_string<_CharT, _Traits, _Allocator>::reserve(size_type __res_arg)
-{
-    if (__res_arg > max_size())
-        this->__throw_length_error();
-    size_type __cap = capacity();
-    size_type __sz = size();
-    __res_arg = _VSTD::max(__res_arg, __sz);
-    __res_arg = __recommend(__res_arg);
-    if (__res_arg != __cap)
-    {
-        pointer __new_data, __p;
-        bool __was_long, __now_long;
-        if (__res_arg == __min_cap - 1)
-        {
-            __was_long = true;
-            __now_long = false;
-            __new_data = __get_short_pointer();
-            __p = __get_long_pointer();
-        }
-        else
-        {
-            if (__res_arg > __cap)
-                __new_data = __alloc_traits::allocate(__alloc(), __res_arg+1);
-            else
-            {
-            #ifndef _LIBCPP_NO_EXCEPTIONS
-                try
-                {
-            #endif  // _LIBCPP_NO_EXCEPTIONS
-                    __new_data = __alloc_traits::allocate(__alloc(), __res_arg+1);
-            #ifndef _LIBCPP_NO_EXCEPTIONS
-                }
-                catch (...)
-                {
-                    return;
-                }
-            #else  // _LIBCPP_NO_EXCEPTIONS
-                if (__new_data == nullptr)
-                    return;
-            #endif  // _LIBCPP_NO_EXCEPTIONS
-            }
-            __now_long = true;
-            __was_long = __is_long();
-            __p = __get_pointer();
-        }
-        traits_type::copy(_VSTD::__to_raw_pointer(__new_data),
-                          _VSTD::__to_raw_pointer(__p), size()+1);
-        if (__was_long)
-            __alloc_traits::deallocate(__alloc(), __p, __cap+1);
-        if (__now_long)
-        {
-            __set_long_cap(__res_arg+1);
-            __set_long_size(__sz);
-            __set_long_pointer(__new_data);
-        }
-        else
-            __set_short_size(__sz);
-        __invalidate_all_iterators();
-    }
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::const_reference
-basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
-    return *(data() + __pos);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::reference
-basic_string<_CharT, _Traits, _Allocator>::operator[](size_type __pos) _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__pos <= size(), "string index out of bounds");
-    return *(__get_pointer() + __pos);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::const_reference
-basic_string<_CharT, _Traits, _Allocator>::at(size_type __n) const
-{
-    if (__n >= size())
-        this->__throw_out_of_range();
-    return (*this)[__n];
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::reference
-basic_string<_CharT, _Traits, _Allocator>::at(size_type __n)
-{
-    if (__n >= size())
-        this->__throw_out_of_range();
-    return (*this)[__n];
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::reference
-basic_string<_CharT, _Traits, _Allocator>::front()
-{
-    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
-    return *__get_pointer();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::const_reference
-basic_string<_CharT, _Traits, _Allocator>::front() const
-{
-    _LIBCPP_ASSERT(!empty(), "string::front(): string is empty");
-    return *data();
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::reference
-basic_string<_CharT, _Traits, _Allocator>::back()
-{
-    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
-    return *(__get_pointer() + size() - 1);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::const_reference
-basic_string<_CharT, _Traits, _Allocator>::back() const
-{
-    _LIBCPP_ASSERT(!empty(), "string::back(): string is empty");
-    return *(data() + size() - 1);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::copy(value_type* __s, size_type __n, size_type __pos) const
-{
-    size_type __sz = size();
-    if (__pos > __sz)
-        this->__throw_out_of_range();
-    size_type __rlen = _VSTD::min(__n, __sz - __pos);
-    traits_type::copy(__s, data() + __pos, __rlen);
-    return __rlen;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>
-basic_string<_CharT, _Traits, _Allocator>::substr(size_type __pos, size_type __n) const
-{
-    return basic_string(*this, __pos, __n, __alloc());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-void
-basic_string<_CharT, _Traits, _Allocator>::swap(basic_string& __str)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT_DEBUG
-#else
-        _NOEXCEPT_DEBUG_(!__alloc_traits::propagate_on_container_swap::value ||
-                    __is_nothrow_swappable<allocator_type>::value)
-#endif
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    if (!__is_long())
-        __get_db()->__invalidate_all(this);
-    if (!__str.__is_long())
-        __get_db()->__invalidate_all(&__str);
-    __get_db()->swap(this, &__str);
-#endif
-    _LIBCPP_ASSERT(
-        __alloc_traits::propagate_on_container_swap::value ||
-        __alloc_traits::is_always_equal::value ||
-        __alloc() == __str.__alloc(), "swapping non-equal allocators");
-    _VSTD::swap(__r_.first(), __str.__r_.first());
-    __swap_allocator(__alloc(), __str.__alloc());
-}
-
-// find
-
-template <class _Traits>
-struct _LIBCPP_HIDDEN __traits_eq
-{
-    typedef typename _Traits::char_type char_type;
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const char_type& __x, const char_type& __y) _NOEXCEPT
-        {return _Traits::eq(__x, __y);}
-};
-
-template<class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find(const value_type* __s,
-                                                size_type __pos,
-                                                size_type __n) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find(): received nullptr");
-    return __str_find<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, __n);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find(const basic_string& __str,
-                                                size_type __pos) const _NOEXCEPT
-{
-    return __str_find<value_type, size_type, traits_type, npos>
-        (data(), size(), __str.data(), __pos, __str.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type
->::type
-basic_string<_CharT, _Traits, _Allocator>::find(const _Tp &__t,
-                                                size_type __pos) const
-{
-    __self_view __sv = __t;
-    return __str_find<value_type, size_type, traits_type, npos>
-        (data(), size(), __sv.data(), __pos, __sv.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find(const value_type* __s,
-                                                size_type __pos) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::find(): received nullptr");
-    return __str_find<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, traits_type::length(__s));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find(value_type __c,
-                                                size_type __pos) const _NOEXCEPT
-{
-    return __str_find<value_type, size_type, traits_type, npos>
-        (data(), size(), __c, __pos);
-}
-
-// rfind
-
-template<class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::rfind(const value_type* __s,
-                                                 size_type __pos,
-                                                 size_type __n) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::rfind(): received nullptr");
-    return __str_rfind<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, __n);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::rfind(const basic_string& __str,
-                                                 size_type __pos) const _NOEXCEPT
-{
-    return __str_rfind<value_type, size_type, traits_type, npos>
-        (data(), size(), __str.data(), __pos, __str.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type
->::type
-basic_string<_CharT, _Traits, _Allocator>::rfind(const _Tp& __t,
-                                                size_type __pos) const
-{
-    __self_view __sv = __t;
-    return __str_rfind<value_type, size_type, traits_type, npos>
-        (data(), size(), __sv.data(), __pos, __sv.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::rfind(const value_type* __s,
-                                                 size_type __pos) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::rfind(): received nullptr");
-    return __str_rfind<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, traits_type::length(__s));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::rfind(value_type __c,
-                                                 size_type __pos) const _NOEXCEPT
-{
-    return __str_rfind<value_type, size_type, traits_type, npos>
-        (data(), size(), __c, __pos);
-}
-
-// find_first_of
-
-template<class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_first_of(const value_type* __s,
-                                                         size_type __pos,
-                                                         size_type __n) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_first_of(): received nullptr");
-    return __str_find_first_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, __n);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_first_of(const basic_string& __str,
-                                                         size_type __pos) const _NOEXCEPT
-{
-    return __str_find_first_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __str.data(), __pos, __str.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type
->::type
-basic_string<_CharT, _Traits, _Allocator>::find_first_of(const _Tp& __t,
-                                                size_type __pos) const
-{
-    __self_view __sv = __t;
-    return __str_find_first_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __sv.data(), __pos, __sv.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_first_of(const value_type* __s,
-                                                         size_type __pos) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::find_first_of(): received nullptr");
-    return __str_find_first_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, traits_type::length(__s));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_first_of(value_type __c,
-                                                         size_type __pos) const _NOEXCEPT
-{
-    return find(__c, __pos);
-}
-
-// find_last_of
-
-template<class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_last_of(const value_type* __s,
-                                                        size_type __pos,
-                                                        size_type __n) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_last_of(): received nullptr");
-    return __str_find_last_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, __n);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_last_of(const basic_string& __str,
-                                                        size_type __pos) const _NOEXCEPT
-{
-    return __str_find_last_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __str.data(), __pos, __str.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type
->::type
-basic_string<_CharT, _Traits, _Allocator>::find_last_of(const _Tp& __t,
-                                                size_type __pos) const
-{
-    __self_view __sv = __t;
-    return __str_find_last_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __sv.data(), __pos, __sv.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_last_of(const value_type* __s,
-                                                        size_type __pos) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::find_last_of(): received nullptr");
-    return __str_find_last_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, traits_type::length(__s));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_last_of(value_type __c,
-                                                        size_type __pos) const _NOEXCEPT
-{
-    return rfind(__c, __pos);
-}
-
-// find_first_not_of
-
-template<class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const value_type* __s,
-                                                             size_type __pos,
-                                                             size_type __n) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_first_not_of(): received nullptr");
-    return __str_find_first_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, __n);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const basic_string& __str,
-                                                             size_type __pos) const _NOEXCEPT
-{
-    return __str_find_first_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __str.data(), __pos, __str.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type
->::type
-basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const _Tp& __t,
-                                                size_type __pos) const
-{
-    __self_view __sv = __t;
-    return __str_find_first_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __sv.data(), __pos, __sv.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(const value_type* __s,
-                                                             size_type __pos) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::find_first_not_of(): received nullptr");
-    return __str_find_first_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, traits_type::length(__s));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_first_not_of(value_type __c,
-                                                             size_type __pos) const _NOEXCEPT
-{
-    return __str_find_first_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __c, __pos);
-}
-
-// find_last_not_of
-
-template<class _CharT, class _Traits, class _Allocator>
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const value_type* __s,
-                                                            size_type __pos,
-                                                            size_type __n) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string::find_last_not_of(): received nullptr");
-    return __str_find_last_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, __n);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const basic_string& __str,
-                                                            size_type __pos) const _NOEXCEPT
-{
-    return __str_find_last_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __str.data(), __pos, __str.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type
->::type
-basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const _Tp& __t,
-                                                size_type __pos) const
-{
-    __self_view __sv = __t;
-    return __str_find_last_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __sv.data(), __pos, __sv.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(const value_type* __s,
-                                                            size_type __pos) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::find_last_not_of(): received nullptr");
-    return __str_find_last_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __s, __pos, traits_type::length(__s));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-typename basic_string<_CharT, _Traits, _Allocator>::size_type
-basic_string<_CharT, _Traits, _Allocator>::find_last_not_of(value_type __c,
-                                                            size_type __pos) const _NOEXCEPT
-{
-    return __str_find_last_not_of<value_type, size_type, traits_type, npos>
-        (data(), size(), __c, __pos);
-}
-
-// compare
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    int
->::type
-basic_string<_CharT, _Traits, _Allocator>::compare(const _Tp& __t) const
-{
-    __self_view __sv = __t;
-    size_t __lhs_sz = size();
-    size_t __rhs_sz = __sv.size();
-    int __result = traits_type::compare(data(), __sv.data(),
-                                        _VSTD::min(__lhs_sz, __rhs_sz));
-    if (__result != 0)
-        return __result;
-    if (__lhs_sz < __rhs_sz)
-        return -1;
-    if (__lhs_sz > __rhs_sz)
-        return 1;
-    return 0;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-int
-basic_string<_CharT, _Traits, _Allocator>::compare(const basic_string& __str) const _NOEXCEPT
-{
-    return compare(__self_view(__str));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-int
-basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
-                                                   size_type __n1,
-                                                   const value_type* __s,
-                                                   size_type __n2) const
-{
-    _LIBCPP_ASSERT(__n2 == 0 || __s != nullptr, "string::compare(): received nullptr");
-    size_type __sz = size();
-    if (__pos1 > __sz || __n2 == npos)
-        this->__throw_out_of_range();
-    size_type __rlen = _VSTD::min(__n1, __sz - __pos1);
-    int __r = traits_type::compare(data() + __pos1, __s, _VSTD::min(__rlen, __n2));
-    if (__r == 0)
-    {
-        if (__rlen < __n2)
-            __r = -1;
-        else if (__rlen > __n2)
-            __r = 1;
-    }
-    return __r;
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    int
->::type
-basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
-                                                   size_type __n1,
-                                                   const _Tp& __t) const
-{
-    __self_view __sv = __t;
-    return compare(__pos1, __n1, __sv.data(), __sv.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-inline
-int
-basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
-                                                   size_type __n1,
-                                                   const basic_string& __str) const
-{
-    return compare(__pos1, __n1, __str.data(), __str.size());
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-template <class _Tp>
-typename enable_if
-<
-    __can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value,
-    int
->::type
-basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
-                                                   size_type __n1,
-                                                   const _Tp& __t,
-                                                   size_type __pos2,
-                                                   size_type __n2) const
-{
-    __self_view __sv = __t;
-    return __self_view(*this).substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-int
-basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
-                                                   size_type __n1,
-                                                   const basic_string& __str,
-                                                   size_type __pos2,
-                                                   size_type __n2) const
-{
-        return compare(__pos1, __n1, __self_view(__str), __pos2, __n2);
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-int
-basic_string<_CharT, _Traits, _Allocator>::compare(const value_type* __s) const _NOEXCEPT
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::compare(): received nullptr");
-    return compare(0, npos, __s, traits_type::length(__s));
-}
-
-template <class _CharT, class _Traits, class _Allocator>
-int
-basic_string<_CharT, _Traits, _Allocator>::compare(size_type __pos1,
-                                                   size_type __n1,
-                                                   const value_type* __s) const
-{
-    _LIBCPP_ASSERT(__s != nullptr, "string::compare(): received nullptr");
-    return compare(__pos1, __n1, __s, traits_type::length(__s));
-}
-
-// __invariants
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-bool
-basic_string<_CharT, _Traits, _Allocator>::__invariants() const
-{
-    if (size() > capacity())
-        return false;
-    if (capacity() < __min_cap - 1)
-        return false;
-    if (data() == 0)
-        return false;
-    if (data()[size()] != value_type(0))
-        return false;
-    return true;
-}
-
-// __clear_and_shrink
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-void 
-basic_string<_CharT, _Traits, _Allocator>::__clear_and_shrink() _NOEXCEPT
-{
-    clear();
-    if(__is_long())
-    {
-        __alloc_traits::deallocate(__alloc(), __get_long_pointer(), capacity() + 1);
-        __set_long_cap(0);
-        __set_short_size(0);
-    }
-} 
-
-// operator==
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    size_t __lhs_sz = __lhs.size();
-    return __lhs_sz == __rhs.size() && _Traits::compare(__lhs.data(),
-                                                        __rhs.data(),
-                                                        __lhs_sz) == 0;
-}
-
-template<class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const basic_string<char, char_traits<char>, _Allocator>& __lhs,
-           const basic_string<char, char_traits<char>, _Allocator>& __rhs) _NOEXCEPT
-{
-    size_t __lhs_sz = __lhs.size();
-    if (__lhs_sz != __rhs.size())
-        return false;
-    const char* __lp = __lhs.data();
-    const char* __rp = __rhs.data();
-    if (__lhs.__is_long())
-        return char_traits<char>::compare(__lp, __rp, __lhs_sz) == 0;
-    for (; __lhs_sz != 0; --__lhs_sz, ++__lp, ++__rp)
-        if (*__lp != *__rp)
-            return false;
-    return true;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const _CharT* __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    typedef basic_string<_CharT, _Traits, _Allocator> _String;
-    _LIBCPP_ASSERT(__lhs != nullptr, "operator==(char*, basic_string): received nullptr");
-    size_t __lhs_len = _Traits::length(__lhs);
-    if (__lhs_len != __rhs.size()) return false;
-    return __rhs.compare(0, _String::npos, __lhs, __lhs_len) == 0;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const basic_string<_CharT,_Traits,_Allocator>& __lhs,
-           const _CharT* __rhs) _NOEXCEPT
-{
-    typedef basic_string<_CharT, _Traits, _Allocator> _String;
-    _LIBCPP_ASSERT(__rhs != nullptr, "operator==(basic_string, char*): received nullptr");
-    size_t __rhs_len = _Traits::length(__rhs);
-    if (__rhs_len != __lhs.size()) return false;
-    return __lhs.compare(0, _String::npos, __rhs, __rhs_len) == 0;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const basic_string<_CharT,_Traits,_Allocator>& __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return !(__lhs == __rhs);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const _CharT* __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return !(__lhs == __rhs);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const _CharT* __rhs) _NOEXCEPT
-{
-    return !(__lhs == __rhs);
-}
-
-// operator<
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) < 0;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const _CharT* __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) < 0;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const _CharT* __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return __rhs.compare(__lhs) > 0;
-}
-
-// operator>
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return __rhs < __lhs;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const _CharT* __rhs) _NOEXCEPT
-{
-    return __rhs < __lhs;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const _CharT* __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return __rhs < __lhs;
-}
-
-// operator<=
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return !(__rhs < __lhs);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const _CharT* __rhs) _NOEXCEPT
-{
-    return !(__rhs < __lhs);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const _CharT* __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return !(__rhs < __lhs);
-}
-
-// operator>=
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return !(__lhs < __rhs);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-           const _CharT* __rhs) _NOEXCEPT
-{
-    return !(__lhs < __rhs);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const _CharT* __lhs,
-           const basic_string<_CharT, _Traits, _Allocator>& __rhs) _NOEXCEPT
-{
-    return !(__lhs < __rhs);
-}
-
-// operator +
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs,
-          const basic_string<_CharT, _Traits, _Allocator>& __rhs)
-{
-    basic_string<_CharT, _Traits, _Allocator> __r(__lhs.get_allocator());
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = __lhs.size();
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = __rhs.size();
-    __r.__init(__lhs.data(), __lhs_sz, __lhs_sz + __rhs_sz);
-    __r.append(__rhs.data(), __rhs_sz);
-    return __r;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const _CharT* __lhs , const basic_string<_CharT,_Traits,_Allocator>& __rhs)
-{
-    basic_string<_CharT, _Traits, _Allocator> __r(__rhs.get_allocator());
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = _Traits::length(__lhs);
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = __rhs.size();
-    __r.__init(__lhs, __lhs_sz, __lhs_sz + __rhs_sz);
-    __r.append(__rhs.data(), __rhs_sz);
-    return __r;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-operator+(_CharT __lhs, const basic_string<_CharT,_Traits,_Allocator>& __rhs)
-{
-    basic_string<_CharT, _Traits, _Allocator> __r(__rhs.get_allocator());
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = __rhs.size();
-    __r.__init(&__lhs, 1, 1 + __rhs_sz);
-    __r.append(__rhs.data(), __rhs_sz);
-    return __r;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, const _CharT* __rhs)
-{
-    basic_string<_CharT, _Traits, _Allocator> __r(__lhs.get_allocator());
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = __lhs.size();
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type __rhs_sz = _Traits::length(__rhs);
-    __r.__init(__lhs.data(), __lhs_sz, __lhs_sz + __rhs_sz);
-    __r.append(__rhs, __rhs_sz);
-    return __r;
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, _CharT __rhs)
-{
-    basic_string<_CharT, _Traits, _Allocator> __r(__lhs.get_allocator());
-    typename basic_string<_CharT, _Traits, _Allocator>::size_type __lhs_sz = __lhs.size();
-    __r.__init(__lhs.data(), __lhs_sz, __lhs_sz + 1);
-    __r.push_back(__rhs);
-    return __r;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _Traits, _Allocator>
-operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const basic_string<_CharT, _Traits, _Allocator>& __rhs)
-{
-    return _VSTD::move(__lhs.append(__rhs));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const basic_string<_CharT, _Traits, _Allocator>& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs)
-{
-    return _VSTD::move(__rhs.insert(0, __lhs));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _Traits, _Allocator>
-operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, basic_string<_CharT, _Traits, _Allocator>&& __rhs)
-{
-    return _VSTD::move(__lhs.append(__rhs));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _Traits, _Allocator>
-operator+(const _CharT* __lhs , basic_string<_CharT,_Traits,_Allocator>&& __rhs)
-{
-    return _VSTD::move(__rhs.insert(0, __lhs));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _Traits, _Allocator>
-operator+(_CharT __lhs, basic_string<_CharT,_Traits,_Allocator>&& __rhs)
-{
-    __rhs.insert(__rhs.begin(), __lhs);
-    return _VSTD::move(__rhs);
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _Traits, _Allocator>
-operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, const _CharT* __rhs)
-{
-    return _VSTD::move(__lhs.append(__rhs));
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_string<_CharT, _Traits, _Allocator>
-operator+(basic_string<_CharT, _Traits, _Allocator>&& __lhs, _CharT __rhs)
-{
-    __lhs.push_back(__rhs);
-    return _VSTD::move(__lhs);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-// swap
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(basic_string<_CharT, _Traits, _Allocator>& __lhs,
-     basic_string<_CharT, _Traits, _Allocator>& __rhs)
-     _NOEXCEPT_(_NOEXCEPT_(__lhs.swap(__rhs)))
-{
-    __lhs.swap(__rhs);
-}
-
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-typedef basic_string<char8_t> u8string;
-#endif
-
-#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
-typedef basic_string<char16_t> u16string;
-typedef basic_string<char32_t> u32string;
-#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
-
-_LIBCPP_FUNC_VIS int                stoi  (const string& __str, size_t* __idx = 0, int __base = 10);
-_LIBCPP_FUNC_VIS long               stol  (const string& __str, size_t* __idx = 0, int __base = 10);
-_LIBCPP_FUNC_VIS unsigned long      stoul (const string& __str, size_t* __idx = 0, int __base = 10);
-_LIBCPP_FUNC_VIS long long          stoll (const string& __str, size_t* __idx = 0, int __base = 10);
-_LIBCPP_FUNC_VIS unsigned long long stoull(const string& __str, size_t* __idx = 0, int __base = 10);
-
-_LIBCPP_FUNC_VIS float       stof (const string& __str, size_t* __idx = 0);
-_LIBCPP_FUNC_VIS double      stod (const string& __str, size_t* __idx = 0);
-_LIBCPP_FUNC_VIS long double stold(const string& __str, size_t* __idx = 0);
-
-_LIBCPP_FUNC_VIS string to_string(int __val);
-_LIBCPP_FUNC_VIS string to_string(unsigned __val);
-_LIBCPP_FUNC_VIS string to_string(long __val);
-_LIBCPP_FUNC_VIS string to_string(unsigned long __val);
-_LIBCPP_FUNC_VIS string to_string(long long __val);
-_LIBCPP_FUNC_VIS string to_string(unsigned long long __val);
-_LIBCPP_FUNC_VIS string to_string(float __val);
-_LIBCPP_FUNC_VIS string to_string(double __val);
-_LIBCPP_FUNC_VIS string to_string(long double __val);
-
-_LIBCPP_FUNC_VIS int                stoi  (const wstring& __str, size_t* __idx = 0, int __base = 10);
-_LIBCPP_FUNC_VIS long               stol  (const wstring& __str, size_t* __idx = 0, int __base = 10);
-_LIBCPP_FUNC_VIS unsigned long      stoul (const wstring& __str, size_t* __idx = 0, int __base = 10);
-_LIBCPP_FUNC_VIS long long          stoll (const wstring& __str, size_t* __idx = 0, int __base = 10);
-_LIBCPP_FUNC_VIS unsigned long long stoull(const wstring& __str, size_t* __idx = 0, int __base = 10);
-
-_LIBCPP_FUNC_VIS float       stof (const wstring& __str, size_t* __idx = 0);
-_LIBCPP_FUNC_VIS double      stod (const wstring& __str, size_t* __idx = 0);
-_LIBCPP_FUNC_VIS long double stold(const wstring& __str, size_t* __idx = 0);
-
-_LIBCPP_FUNC_VIS wstring to_wstring(int __val);
-_LIBCPP_FUNC_VIS wstring to_wstring(unsigned __val);
-_LIBCPP_FUNC_VIS wstring to_wstring(long __val);
-_LIBCPP_FUNC_VIS wstring to_wstring(unsigned long __val);
-_LIBCPP_FUNC_VIS wstring to_wstring(long long __val);
-_LIBCPP_FUNC_VIS wstring to_wstring(unsigned long long __val);
-_LIBCPP_FUNC_VIS wstring to_wstring(float __val);
-_LIBCPP_FUNC_VIS wstring to_wstring(double __val);
-_LIBCPP_FUNC_VIS wstring to_wstring(long double __val);
-
-template<class _CharT, class _Traits, class _Allocator>
-    const typename basic_string<_CharT, _Traits, _Allocator>::size_type
-                   basic_string<_CharT, _Traits, _Allocator>::npos;
-
-template<class _CharT, class _Traits, class _Allocator>
-struct _LIBCPP_TEMPLATE_VIS hash<basic_string<_CharT, _Traits, _Allocator> >
-    : public unary_function<basic_string<_CharT, _Traits, _Allocator>, size_t>
-{
-    size_t
-        operator()(const basic_string<_CharT, _Traits, _Allocator>& __val) const _NOEXCEPT;
-};
-
-template<class _CharT, class _Traits, class _Allocator>
-size_t
-hash<basic_string<_CharT, _Traits, _Allocator> >::operator()(
-        const basic_string<_CharT, _Traits, _Allocator>& __val) const _NOEXCEPT
-{
-    return __do_string_hash(__val.data(), __val.data() + __val.size());
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_ostream<_CharT, _Traits>&
-operator<<(basic_ostream<_CharT, _Traits>& __os,
-           const basic_string<_CharT, _Traits, _Allocator>& __str);
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is,
-           basic_string<_CharT, _Traits, _Allocator>& __str);
-
-template<class _CharT, class _Traits, class _Allocator>
-basic_istream<_CharT, _Traits>&
-getline(basic_istream<_CharT, _Traits>& __is,
-        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-getline(basic_istream<_CharT, _Traits>& __is,
-        basic_string<_CharT, _Traits, _Allocator>& __str);
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-getline(basic_istream<_CharT, _Traits>&& __is,
-        basic_string<_CharT, _Traits, _Allocator>& __str, _CharT __dlm);
-
-template<class _CharT, class _Traits, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-getline(basic_istream<_CharT, _Traits>&& __is,
-        basic_string<_CharT, _Traits, _Allocator>& __str);
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER > 17
-template<class _CharT, class _Traits, class _Allocator, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase(basic_string<_CharT, _Traits, _Allocator>& __str, const _Up& __v)
-{ __str.erase(_VSTD::remove(__str.begin(), __str.end(), __v), __str.end()); }
-
-template<class _CharT, class _Traits, class _Allocator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(basic_string<_CharT, _Traits, _Allocator>& __str, _Predicate __pred)
-{ __str.erase(_VSTD::remove_if(__str.begin(), __str.end(), __pred), __str.end()); }
-#endif
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-template<class _CharT, class _Traits, class _Allocator>
-bool
-basic_string<_CharT, _Traits, _Allocator>::__dereferenceable(const const_iterator* __i) const
-{
-    return this->data() <= _VSTD::__to_raw_pointer(__i->base()) &&
-           _VSTD::__to_raw_pointer(__i->base()) < this->data() + this->size();
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-bool
-basic_string<_CharT, _Traits, _Allocator>::__decrementable(const const_iterator* __i) const
-{
-    return this->data() < _VSTD::__to_raw_pointer(__i->base()) &&
-           _VSTD::__to_raw_pointer(__i->base()) <= this->data() + this->size();
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-bool
-basic_string<_CharT, _Traits, _Allocator>::__addable(const const_iterator* __i, ptrdiff_t __n) const
-{
-    const value_type* __p = _VSTD::__to_raw_pointer(__i->base()) + __n;
-    return this->data() <= __p && __p <= this->data() + this->size();
-}
-
-template<class _CharT, class _Traits, class _Allocator>
-bool
-basic_string<_CharT, _Traits, _Allocator>::__subscriptable(const const_iterator* __i, ptrdiff_t __n) const
-{
-    const value_type* __p = _VSTD::__to_raw_pointer(__i->base()) + __n;
-    return this->data() <= __p && __p < this->data() + this->size();
-}
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_string<char>)
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS basic_string<wchar_t>)
-
-#if _LIBCPP_STD_VER > 11 
-// Literal suffixes for basic_string [basic.string.literals]
-inline namespace literals
-{
-  inline namespace string_literals
-  {
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_string<char> operator "" s( const char *__str, size_t __len )
-    {
-        return basic_string<char> (__str, __len);
-    }
-
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_string<wchar_t> operator "" s( const wchar_t *__str, size_t __len )
-    {
-        return basic_string<wchar_t> (__str, __len);
-    }
-
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_string<char8_t> operator "" s(const char8_t *__str, size_t __len) _NOEXCEPT
-    {
-        return basic_string<char8_t> (__str, __len);
-    }
-#endif
-
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_string<char16_t> operator "" s( const char16_t *__str, size_t __len )
-    {
-        return basic_string<char16_t> (__str, __len);
-    }
-
-    inline _LIBCPP_INLINE_VISIBILITY
-    basic_string<char32_t> operator "" s( const char32_t *__str, size_t __len )
-    {
-        return basic_string<char32_t> (__str, __len);
-    }
-  }
-}
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_STRING
diff --git a/lib/libcxx/include/string.h b/lib/libcxx/include/string.h
deleted file mode 100644
index a1ce56cbcd6..00000000000
--- a/lib/libcxx/include/string.h
+++ /dev/null
@@ -1,110 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- string.h ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_STRING_H
-#define _LIBCPP_STRING_H
-
-/*
-    string.h synopsis
-
-Macros:
-
-    NULL
-
-Types:
-
-    size_t
-
-void* memcpy(void* restrict s1, const void* restrict s2, size_t n);
-void* memmove(void* s1, const void* s2, size_t n);
-char* strcpy (char* restrict s1, const char* restrict s2);
-char* strncpy(char* restrict s1, const char* restrict s2, size_t n);
-char* strcat (char* restrict s1, const char* restrict s2);
-char* strncat(char* restrict s1, const char* restrict s2, size_t n);
-int memcmp(const void* s1, const void* s2, size_t n);
-int strcmp (const char* s1, const char* s2);
-int strncmp(const char* s1, const char* s2, size_t n);
-int strcoll(const char* s1, const char* s2);
-size_t strxfrm(char* restrict s1, const char* restrict s2, size_t n);
-const void* memchr(const void* s, int c, size_t n);
-      void* memchr(      void* s, int c, size_t n);
-const char* strchr(const char* s, int c);
-      char* strchr(      char* s, int c);
-size_t strcspn(const char* s1, const char* s2);
-const char* strpbrk(const char* s1, const char* s2);
-      char* strpbrk(      char* s1, const char* s2);
-const char* strrchr(const char* s, int c);
-      char* strrchr(      char* s, int c);
-size_t strspn(const char* s1, const char* s2);
-const char* strstr(const char* s1, const char* s2);
-      char* strstr(      char* s1, const char* s2);
-char* strtok(char* restrict s1, const char* restrict s2);
-void* memset(void* s, int c, size_t n);
-char* strerror(int errnum);
-size_t strlen(const char* s);
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <string.h>
-
-// MSVCRT, GNU libc and its derivates may already have the correct prototype in
-// <string.h>. This macro can be defined by users if their C library provides
-// the right signature.
-#if defined(__CORRECT_ISO_CPP_STRING_H_PROTO) || defined(_LIBCPP_MSVCRT) || \
-    defined(__sun__) || defined(_STRING_H_CPLUSPLUS_98_CONFORMANCE_)
-#define _LIBCPP_STRING_H_HAS_CONST_OVERLOADS
-#endif
-
-#if defined(__cplusplus) && !defined(_LIBCPP_STRING_H_HAS_CONST_OVERLOADS) && defined(_LIBCPP_PREFERRED_OVERLOAD)
-extern "C++" {
-inline _LIBCPP_INLINE_VISIBILITY
-char* __libcpp_strchr(const char* __s, int __c) {return (char*)strchr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const char* strchr(const char* __s, int __c) {return __libcpp_strchr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      char* strchr(      char* __s, int __c) {return __libcpp_strchr(__s, __c);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-char* __libcpp_strpbrk(const char* __s1, const char* __s2) {return (char*)strpbrk(__s1, __s2);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const char* strpbrk(const char* __s1, const char* __s2) {return __libcpp_strpbrk(__s1, __s2);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      char* strpbrk(      char* __s1, const char* __s2) {return __libcpp_strpbrk(__s1, __s2);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-char* __libcpp_strrchr(const char* __s, int __c) {return (char*)strrchr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const char* strrchr(const char* __s, int __c) {return __libcpp_strrchr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      char* strrchr(      char* __s, int __c) {return __libcpp_strrchr(__s, __c);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void* __libcpp_memchr(const void* __s, int __c, size_t __n) {return (void*)memchr(__s, __c, __n);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const void* memchr(const void* __s, int __c, size_t __n) {return __libcpp_memchr(__s, __c, __n);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      void* memchr(      void* __s, int __c, size_t __n) {return __libcpp_memchr(__s, __c, __n);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-char* __libcpp_strstr(const char* __s1, const char* __s2) {return (char*)strstr(__s1, __s2);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const char* strstr(const char* __s1, const char* __s2) {return __libcpp_strstr(__s1, __s2);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      char* strstr(      char* __s1, const char* __s2) {return __libcpp_strstr(__s1, __s2);}
-}
-#endif
-
-#endif  // _LIBCPP_STRING_H
diff --git a/lib/libcxx/include/string_view b/lib/libcxx/include/string_view
deleted file mode 100644
index 7d783122f12..00000000000
--- a/lib/libcxx/include/string_view
+++ /dev/null
@@ -1,834 +0,0 @@
-// -*- C++ -*-
-//===------------------------ string_view ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_STRING_VIEW
-#define _LIBCPP_STRING_VIEW
-
-/*
-string_view synopsis
-
-namespace std {
-
-    // 7.2, Class template basic_string_view
-    template<class charT, class traits = char_traits<charT>>
-        class basic_string_view;
-
-    // 7.9, basic_string_view non-member comparison functions
-    template<class charT, class traits>
-    constexpr bool operator==(basic_string_view<charT, traits> x,
-                              basic_string_view<charT, traits> y) noexcept;
-    template<class charT, class traits>
-    constexpr bool operator!=(basic_string_view<charT, traits> x,
-                              basic_string_view<charT, traits> y) noexcept;
-    template<class charT, class traits>
-    constexpr bool operator< (basic_string_view<charT, traits> x,
-                                 basic_string_view<charT, traits> y) noexcept;
-    template<class charT, class traits>
-    constexpr bool operator> (basic_string_view<charT, traits> x,
-                              basic_string_view<charT, traits> y) noexcept;
-    template<class charT, class traits>
-    constexpr bool operator<=(basic_string_view<charT, traits> x,
-                                 basic_string_view<charT, traits> y) noexcept;
-    template<class charT, class traits>
-    constexpr bool operator>=(basic_string_view<charT, traits> x,
-                              basic_string_view<charT, traits> y) noexcept;
-    // see below, sufficient additional overloads of comparison functions
-
-    // 7.10, Inserters and extractors
-    template<class charT, class traits>
-      basic_ostream<charT, traits>&
-        operator<<(basic_ostream<charT, traits>& os,
-                   basic_string_view<charT, traits> str);
-
-    // basic_string_view typedef names
-    typedef basic_string_view<char> string_view;
-    typedef basic_string_view<char16_t> u16string_view;
-    typedef basic_string_view<char32_t> u32string_view;
-    typedef basic_string_view<wchar_t> wstring_view;
-
-    template<class charT, class traits = char_traits<charT>>
-    class basic_string_view {
-      public:
-      // types
-      typedef traits traits_type;
-      typedef charT value_type;
-      typedef charT* pointer;
-      typedef const charT* const_pointer;
-      typedef charT& reference;
-      typedef const charT& const_reference;
-      typedef implementation-defined const_iterator;
-      typedef const_iterator iterator;
-      typedef reverse_iterator<const_iterator> const_reverse_iterator;
-      typedef const_reverse_iterator reverse_iterator;
-      typedef size_t size_type;
-      typedef ptrdiff_t difference_type;
-      static constexpr size_type npos = size_type(-1);
-
-      // 7.3, basic_string_view constructors and assignment operators
-      constexpr basic_string_view() noexcept;
-      constexpr basic_string_view(const basic_string_view&) noexcept = default;
-      basic_string_view& operator=(const basic_string_view&) noexcept = default;
-      template<class Allocator>
-      constexpr basic_string_view(const charT* str);
-      constexpr basic_string_view(const charT* str, size_type len);
-
-      // 7.4, basic_string_view iterator support
-      constexpr const_iterator begin() const noexcept;
-      constexpr const_iterator end() const noexcept;
-      constexpr const_iterator cbegin() const noexcept;
-      constexpr const_iterator cend() const noexcept;
-      const_reverse_iterator rbegin() const noexcept;
-      const_reverse_iterator rend() const noexcept;
-      const_reverse_iterator crbegin() const noexcept;
-      const_reverse_iterator crend() const noexcept;
-
-      // 7.5, basic_string_view capacity
-      constexpr size_type size() const noexcept;
-      constexpr size_type length() const noexcept;
-      constexpr size_type max_size() const noexcept;
-      constexpr bool empty() const noexcept;
-
-      // 7.6, basic_string_view element access
-      constexpr const_reference operator[](size_type pos) const;
-      constexpr const_reference at(size_type pos) const;
-      constexpr const_reference front() const;
-      constexpr const_reference back() const;
-      constexpr const_pointer data() const noexcept;
-
-      // 7.7, basic_string_view modifiers
-      constexpr void remove_prefix(size_type n);
-      constexpr void remove_suffix(size_type n);
-      constexpr void swap(basic_string_view& s) noexcept;
-
-      size_type copy(charT* s, size_type n, size_type pos = 0) const;
-
-      constexpr basic_string_view substr(size_type pos = 0, size_type n = npos) const;
-      constexpr int compare(basic_string_view s) const noexcept;
-      constexpr int compare(size_type pos1, size_type n1, basic_string_view s) const;
-      constexpr int compare(size_type pos1, size_type n1,
-                            basic_string_view s, size_type pos2, size_type n2) const;
-      constexpr int compare(const charT* s) const;
-      constexpr int compare(size_type pos1, size_type n1, const charT* s) const;
-      constexpr int compare(size_type pos1, size_type n1,
-                            const charT* s, size_type n2) const;
-      constexpr size_type find(basic_string_view s, size_type pos = 0) const noexcept;
-      constexpr size_type find(charT c, size_type pos = 0) const noexcept;
-      constexpr size_type find(const charT* s, size_type pos, size_type n) const;
-      constexpr size_type find(const charT* s, size_type pos = 0) const;
-      constexpr size_type rfind(basic_string_view s, size_type pos = npos) const noexcept;
-      constexpr size_type rfind(charT c, size_type pos = npos) const noexcept;
-      constexpr size_type rfind(const charT* s, size_type pos, size_type n) const;
-      constexpr size_type rfind(const charT* s, size_type pos = npos) const;
-      constexpr size_type find_first_of(basic_string_view s, size_type pos = 0) const noexcept;
-      constexpr size_type find_first_of(charT c, size_type pos = 0) const noexcept;
-      constexpr size_type find_first_of(const charT* s, size_type pos, size_type n) const;
-      constexpr size_type find_first_of(const charT* s, size_type pos = 0) const;
-      constexpr size_type find_last_of(basic_string_view s, size_type pos = npos) const noexcept;
-      constexpr size_type find_last_of(charT c, size_type pos = npos) const noexcept;
-      constexpr size_type find_last_of(const charT* s, size_type pos, size_type n) const;
-      constexpr size_type find_last_of(const charT* s, size_type pos = npos) const;
-      constexpr size_type find_first_not_of(basic_string_view s, size_type pos = 0) const noexcept;
-      constexpr size_type find_first_not_of(charT c, size_type pos = 0) const noexcept;
-      constexpr size_type find_first_not_of(const charT* s, size_type pos, size_type n) const;
-      constexpr size_type find_first_not_of(const charT* s, size_type pos = 0) const;
-      constexpr size_type find_last_not_of(basic_string_view s, size_type pos = npos) const noexcept;
-      constexpr size_type find_last_not_of(charT c, size_type pos = npos) const noexcept;
-      constexpr size_type find_last_not_of(const charT* s, size_type pos, size_type n) const;
-      constexpr size_type find_last_not_of(const charT* s, size_type pos = npos) const;
-
-      constexpr bool starts_with(basic_string_view s) const noexcept; // C++2a
-      constexpr bool starts_with(charT c) const noexcept;             // C++2a
-      constexpr bool starts_with(const charT* s) const;               // C++2a
-      constexpr bool ends_with(basic_string_view s) const noexcept;   // C++2a
-      constexpr bool ends_with(charT c) const noexcept;               // C++2a
-      constexpr bool ends_with(const charT* s) const;                 // C++2a
-
-     private:
-      const_pointer data_;  // exposition only
-      size_type     size_;  // exposition only
-    };
-
-  // 7.11, Hash support
-  template <class T> struct hash;
-  template <> struct hash<string_view>;
-  template <> struct hash<u16string_view>;
-  template <> struct hash<u32string_view>;
-  template <> struct hash<wstring_view>;
-
-  constexpr basic_string_view<char>     operator "" sv( const char *str,     size_t len ) noexcept;
-  constexpr basic_string_view<wchar_t>  operator "" sv( const wchar_t *str,  size_t len ) noexcept;
-  constexpr basic_string_view<char16_t> operator "" sv( const char16_t *str, size_t len ) noexcept;
-  constexpr basic_string_view<char32_t> operator "" sv( const char32_t *str, size_t len ) noexcept;
-
-}  // namespace std
-
-
-*/
-
-#include <__config>
-#include <__string>
-#include <algorithm>
-#include <iterator>
-#include <limits>
-#include <stdexcept>
-#include <version>
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template<class _CharT, class _Traits = char_traits<_CharT> >
-class _LIBCPP_TEMPLATE_VIS basic_string_view {
-public:
-    // types
-    typedef _Traits                                    traits_type;
-    typedef _CharT                                     value_type;
-    typedef _CharT*                                    pointer;
-    typedef const _CharT*                              const_pointer;
-    typedef _CharT&                                    reference;
-    typedef const _CharT&                              const_reference;
-    typedef const_pointer                              const_iterator; // See [string.view.iterators]
-    typedef const_iterator                             iterator;
-    typedef _VSTD::reverse_iterator<const_iterator>    const_reverse_iterator;
-    typedef const_reverse_iterator                     reverse_iterator;
-    typedef size_t                                     size_type;
-    typedef ptrdiff_t                                  difference_type;
-    static _LIBCPP_CONSTEXPR const size_type npos = -1; // size_type(-1);
-
-    static_assert((!is_array<value_type>::value), "Character type of basic_string_view must not be an array");
-    static_assert(( is_standard_layout<value_type>::value), "Character type of basic_string_view must be standard-layout");
-    static_assert(( is_trivial<value_type>::value), "Character type of basic_string_view must be trivial");
-    static_assert((is_same<_CharT, typename traits_type::char_type>::value),
-                  "traits_type::char_type must be the same type as CharT");
-
-    // [string.view.cons], construct/copy
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    basic_string_view() _NOEXCEPT : __data (nullptr), __size(0) {}
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    basic_string_view(const basic_string_view&) _NOEXCEPT = default;
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    basic_string_view& operator=(const basic_string_view&) _NOEXCEPT = default;
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    basic_string_view(const _CharT* __s, size_type __len) _NOEXCEPT
-        : __data(__s), __size(__len)
-    {
-// #if _LIBCPP_STD_VER > 11
-//         _LIBCPP_ASSERT(__len == 0 || __s != nullptr, "string_view::string_view(_CharT *, size_t): received nullptr");
-// #endif
-    }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    basic_string_view(const _CharT* __s)
-        : __data(__s), __size(_Traits::length(__s)) {}
-
-    // [string.view.iterators], iterators
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const _NOEXCEPT { return cbegin(); }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const _NOEXCEPT { return cend(); }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT { return __data; }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend()   const _NOEXCEPT { return __data + __size; }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin()   const _NOEXCEPT { return const_reverse_iterator(cend()); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend()     const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin()  const _NOEXCEPT { return const_reverse_iterator(cend()); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX14 _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend()    const _NOEXCEPT { return const_reverse_iterator(cbegin()); }
-
-    // [string.view.capacity], capacity
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    size_type size()     const _NOEXCEPT { return __size; }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    size_type length()   const _NOEXCEPT { return __size; }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT { return numeric_limits<size_type>::max(); }
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    bool empty()         const _NOEXCEPT { return __size == 0; }
-
-    // [string.view.access], element access
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_reference operator[](size_type __pos) const _NOEXCEPT { return __data[__pos]; }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_reference at(size_type __pos) const
-    {
-        return __pos >= size()
-            ? (__throw_out_of_range("string_view::at"), __data[0])
-            : __data[__pos];
-    }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_reference front() const
-    {
-        return _LIBCPP_ASSERT(!empty(), "string_view::front(): string is empty"), __data[0];
-    }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_reference back() const
-    {
-        return _LIBCPP_ASSERT(!empty(), "string_view::back(): string is empty"), __data[__size-1];
-    }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    const_pointer data() const _NOEXCEPT { return __data; }
-
-    // [string.view.modifiers], modifiers:
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    void remove_prefix(size_type __n) _NOEXCEPT
-    {
-        _LIBCPP_ASSERT(__n <= size(), "remove_prefix() can't remove more than size()");
-        __data += __n;
-        __size -= __n;
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    void remove_suffix(size_type __n) _NOEXCEPT
-    {
-        _LIBCPP_ASSERT(__n <= size(), "remove_suffix() can't remove more than size()");
-        __size -= __n;
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    void swap(basic_string_view& __other) _NOEXCEPT
-    {
-        const value_type *__p = __data;
-        __data = __other.__data;
-        __other.__data = __p;
-
-        size_type __sz = __size;
-        __size = __other.__size;
-        __other.__size = __sz;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type copy(_CharT* __s, size_type __n, size_type __pos = 0) const
-    {
-        if (__pos > size())
-            __throw_out_of_range("string_view::copy");
-        size_type __rlen = _VSTD::min(__n, size() - __pos);
-        _Traits::copy(__s, data() + __pos, __rlen);
-        return __rlen;
-    }
-
-    _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-    basic_string_view substr(size_type __pos = 0, size_type __n = npos) const
-    {
-        return __pos > size()
-            ? (__throw_out_of_range("string_view::substr"), basic_string_view())
-            : basic_string_view(data() + __pos, _VSTD::min(__n, size() - __pos));
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 int compare(basic_string_view __sv) const _NOEXCEPT
-    {
-        size_type __rlen = _VSTD::min( size(), __sv.size());
-        int __retval = _Traits::compare(data(), __sv.data(), __rlen);
-        if ( __retval == 0 ) // first __rlen chars matched
-            __retval = size() == __sv.size() ? 0 : ( size() < __sv.size() ? -1 : 1 );
-        return __retval;
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    int compare(size_type __pos1, size_type __n1, basic_string_view __sv) const
-    {
-        return substr(__pos1, __n1).compare(__sv);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    int compare(                       size_type __pos1, size_type __n1, 
-                basic_string_view __sv, size_type __pos2, size_type __n2) const
-    {
-        return substr(__pos1, __n1).compare(__sv.substr(__pos2, __n2));
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    int compare(const _CharT* __s) const _NOEXCEPT
-    {
-        return compare(basic_string_view(__s));
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    int compare(size_type __pos1, size_type __n1, const _CharT* __s) const
-    {
-        return substr(__pos1, __n1).compare(basic_string_view(__s));
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    int compare(size_type __pos1, size_type __n1, const _CharT* __s, size_type __n2) const
-    {
-        return substr(__pos1, __n1).compare(basic_string_view(__s, __n2));
-    }
-
-    // find
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
-    {
-        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
-        return __str_find<value_type, size_type, traits_type, npos>
-            (data(), size(), __s.data(), __pos, __s.size());
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find(_CharT __c, size_type __pos = 0) const _NOEXCEPT
-    {
-        return __str_find<value_type, size_type, traits_type, npos>
-            (data(), size(), __c, __pos);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find(const _CharT* __s, size_type __pos, size_type __n) const
-    {
-        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find(): received nullptr");
-        return __str_find<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, __n);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find(const _CharT* __s, size_type __pos = 0) const
-    {
-        _LIBCPP_ASSERT(__s != nullptr, "string_view::find(): received nullptr");
-        return __str_find<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, traits_type::length(__s));
-    }
-
-    // rfind
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type rfind(basic_string_view __s, size_type __pos = npos) const _NOEXCEPT
-    {
-        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find(): received nullptr");
-        return __str_rfind<value_type, size_type, traits_type, npos>
-            (data(), size(), __s.data(), __pos, __s.size());
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type rfind(_CharT __c, size_type __pos = npos) const _NOEXCEPT
-    {
-        return __str_rfind<value_type, size_type, traits_type, npos>
-            (data(), size(), __c, __pos);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type rfind(const _CharT* __s, size_type __pos, size_type __n) const
-    {
-        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::rfind(): received nullptr");
-        return __str_rfind<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, __n);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type rfind(const _CharT* __s, size_type __pos=npos) const
-    {
-        _LIBCPP_ASSERT(__s != nullptr, "string_view::rfind(): received nullptr");
-        return __str_rfind<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, traits_type::length(__s));
-    }
-
-    // find_first_of
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_of(basic_string_view __s, size_type __pos = 0) const _NOEXCEPT
-    {
-        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_of(): received nullptr");
-        return __str_find_first_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s.data(), __pos, __s.size());
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_of(_CharT __c, size_type __pos = 0) const _NOEXCEPT
-    { return find(__c, __pos); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_of(const _CharT* __s, size_type __pos, size_type __n) const
-    {
-        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_of(): received nullptr");
-        return __str_find_first_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, __n);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_of(const _CharT* __s, size_type __pos=0) const
-    {
-        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_of(): received nullptr");
-        return __str_find_first_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, traits_type::length(__s));
-    }
-
-    // find_last_of
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
-    {
-        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_of(): received nullptr");
-        return __str_find_last_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s.data(), __pos, __s.size());
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_of(_CharT __c, size_type __pos = npos) const _NOEXCEPT
-    { return rfind(__c, __pos); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_of(const _CharT* __s, size_type __pos, size_type __n) const
-    {
-        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_of(): received nullptr");
-        return __str_find_last_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, __n);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_of(const _CharT* __s, size_type __pos=npos) const
-    {
-        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_of(): received nullptr");
-        return __str_find_last_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, traits_type::length(__s));
-    }
-
-    // find_first_not_of
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_not_of(basic_string_view __s, size_type __pos=0) const _NOEXCEPT
-    {
-        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_first_not_of(): received nullptr");
-        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s.data(), __pos, __s.size());
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_not_of(_CharT __c, size_type __pos=0) const _NOEXCEPT
-    {
-        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __c, __pos);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_not_of(const _CharT* __s, size_type __pos, size_type __n) const
-    {
-        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_first_not_of(): received nullptr");
-        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, __n);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_first_not_of(const _CharT* __s, size_type __pos=0) const
-    {
-        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_first_not_of(): received nullptr");
-        return __str_find_first_not_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, traits_type::length(__s));
-    }
-
-    // find_last_not_of
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_not_of(basic_string_view __s, size_type __pos=npos) const _NOEXCEPT
-    {
-        _LIBCPP_ASSERT(__s.size() == 0 || __s.data() != nullptr, "string_view::find_last_not_of(): received nullptr");
-        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s.data(), __pos, __s.size());
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_not_of(_CharT __c, size_type __pos=npos) const _NOEXCEPT
-    {
-        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __c, __pos);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_not_of(const _CharT* __s, size_type __pos, size_type __n) const
-    {
-        _LIBCPP_ASSERT(__n == 0 || __s != nullptr, "string_view::find_last_not_of(): received nullptr");
-        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, __n);
-    }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    size_type find_last_not_of(const _CharT* __s, size_type __pos=npos) const
-    {
-        _LIBCPP_ASSERT(__s != nullptr, "string_view::find_last_not_of(): received nullptr");
-        return __str_find_last_not_of<value_type, size_type, traits_type, npos>
-            (data(), size(), __s, __pos, traits_type::length(__s));
-    }
-
-#if _LIBCPP_STD_VER > 17
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool starts_with(basic_string_view __s) const _NOEXCEPT
-    { return size() >= __s.size() && compare(0, __s.size(), __s) == 0; }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool starts_with(value_type __c) const _NOEXCEPT
-    { return !empty() && _Traits::eq(front(), __c); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool starts_with(const value_type* __s) const _NOEXCEPT
-    { return starts_with(basic_string_view(__s)); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool ends_with(basic_string_view __s) const _NOEXCEPT
-    { return size() >= __s.size() && compare(size() - __s.size(), npos, __s) == 0; }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool ends_with(value_type __c) const _NOEXCEPT
-    { return !empty() && _Traits::eq(back(), __c); }
-
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-    bool ends_with(const value_type* __s) const _NOEXCEPT
-    { return ends_with(basic_string_view(__s)); }
-#endif
-
-private:
-    const   value_type* __data;
-    size_type           __size;
-};
-
-
-// [string.view.comparison]
-// operator ==
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator==(basic_string_view<_CharT, _Traits> __lhs,
-                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    if ( __lhs.size() != __rhs.size()) return false;
-    return __lhs.compare(__rhs) == 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator==(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
-{
-    if ( __lhs.size() != __rhs.size()) return false;
-    return __lhs.compare(__rhs) == 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator==(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
-                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    if ( __lhs.size() != __rhs.size()) return false;
-    return __lhs.compare(__rhs) == 0;
-}
-
-
-// operator !=
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator!=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    if ( __lhs.size() != __rhs.size())
-        return true;
-    return __lhs.compare(__rhs) != 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator!=(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
-{
-    if ( __lhs.size() != __rhs.size())
-        return true;
-    return __lhs.compare(__rhs) != 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator!=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
-                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    if ( __lhs.size() != __rhs.size())
-        return true;
-    return __lhs.compare(__rhs) != 0;
-}
-
-
-// operator <
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator<(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) < 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator<(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) < 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator<(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
-                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) < 0;
-}
-
-
-// operator >
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator> (basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) > 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator>(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) > 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator>(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
-                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) > 0;
-}
-
-
-// operator <=
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator<=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) <= 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator<=(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) <= 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator<=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
-                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) <= 0;
-}
-
-
-// operator >=
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator>=(basic_string_view<_CharT, _Traits> __lhs, basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) >= 0;
-}
-
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator>=(basic_string_view<_CharT, _Traits> __lhs,
-                typename common_type<basic_string_view<_CharT, _Traits> >::type __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) >= 0;
-}
-
-template<class _CharT, class _Traits>
-_LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-bool operator>=(typename common_type<basic_string_view<_CharT, _Traits> >::type __lhs, 
-                basic_string_view<_CharT, _Traits> __rhs) _NOEXCEPT
-{
-    return __lhs.compare(__rhs) >= 0;
-}
-
-typedef basic_string_view<char>     string_view;
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-typedef basic_string_view<char8_t>  u8string_view;
-#endif
-typedef basic_string_view<char16_t> u16string_view;
-typedef basic_string_view<char32_t> u32string_view;
-typedef basic_string_view<wchar_t>  wstring_view;
-
-// [string.view.hash]
-template<class _CharT, class _Traits>
-struct _LIBCPP_TEMPLATE_VIS hash<basic_string_view<_CharT, _Traits> >
-    : public unary_function<basic_string_view<_CharT, _Traits>, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const basic_string_view<_CharT, _Traits> __val) const _NOEXCEPT {
-        return __do_string_hash(__val.data(), __val.data() + __val.size());
-    }
-};
-
-
-#if _LIBCPP_STD_VER > 11 
-inline namespace literals
-{
-  inline namespace string_view_literals
-  {
-    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    basic_string_view<char> operator "" sv(const char *__str, size_t __len) _NOEXCEPT
-    {
-        return basic_string_view<char> (__str, __len);
-    }
-
-    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len) _NOEXCEPT
-    {
-        return basic_string_view<wchar_t> (__str, __len);
-    }
-
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    basic_string_view<char8_t> operator "" sv(const char8_t *__str, size_t __len) _NOEXCEPT
-    {
-        return basic_string_view<char8_t> (__str, __len);
-    }
-#endif
-
-    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len) _NOEXCEPT
-    {
-        return basic_string_view<char16_t> (__str, __len);
-    }
-
-    inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len) _NOEXCEPT
-    {
-        return basic_string_view<char32_t> (__str, __len);
-    }
-  }
-}
-#endif
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif // _LIBCPP_STRING_VIEW
diff --git a/lib/libcxx/include/strstream b/lib/libcxx/include/strstream
deleted file mode 100644
index b00b9d830df..00000000000
--- a/lib/libcxx/include/strstream
+++ /dev/null
@@ -1,400 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- strstream --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_STRSTREAM
-#define _LIBCPP_STRSTREAM
-
-/*
-    strstream synopsis
-
-class strstreambuf
-    : public basic_streambuf<char>
-{
-public:
-    explicit strstreambuf(streamsize alsize_arg = 0);
-    strstreambuf(void* (*palloc_arg)(size_t), void (*pfree_arg)(void*));
-    strstreambuf(char* gnext_arg, streamsize n, char* pbeg_arg = 0);
-    strstreambuf(const char* gnext_arg, streamsize n);
-
-    strstreambuf(signed char* gnext_arg, streamsize n, signed char* pbeg_arg = 0);
-    strstreambuf(const signed char* gnext_arg, streamsize n);
-    strstreambuf(unsigned char* gnext_arg, streamsize n, unsigned char* pbeg_arg = 0);
-    strstreambuf(const unsigned char* gnext_arg, streamsize n);
-
-    strstreambuf(strstreambuf&& rhs);
-    strstreambuf& operator=(strstreambuf&& rhs);
-
-    virtual ~strstreambuf();
-
-    void swap(strstreambuf& rhs);
-
-    void freeze(bool freezefl = true);
-    char* str();
-    int pcount() const;
-
-protected:
-    virtual int_type overflow (int_type c = EOF);
-    virtual int_type pbackfail(int_type c = EOF);
-    virtual int_type underflow();
-    virtual pos_type seekoff(off_type off, ios_base::seekdir way,
-                             ios_base::openmode which = ios_base::in | ios_base::out);
-    virtual pos_type seekpos(pos_type sp,
-                             ios_base::openmode which = ios_base::in | ios_base::out);
-    virtual streambuf* setbuf(char* s, streamsize n);
-
-private:
-    typedef T1 strstate;                // exposition only
-    static const strstate allocated;    // exposition only
-    static const strstate constant;     // exposition only
-    static const strstate dynamic;      // exposition only
-    static const strstate frozen;       // exposition only
-    strstate strmode;                   // exposition only
-    streamsize alsize;                  // exposition only
-    void* (*palloc)(size_t);            // exposition only
-    void (*pfree)(void*);               // exposition only
-};
-
-class istrstream
-    : public basic_istream<char>
-{
-public:
-    explicit istrstream(const char* s);
-    explicit istrstream(char* s);
-    istrstream(const char* s, streamsize n);
-    istrstream(char* s, streamsize n);
-
-    virtual ~istrstream();
-
-    strstreambuf* rdbuf() const;
-    char *str();
-
-private:
-    strstreambuf sb; // exposition only
-};
-
-class ostrstream
-    : public basic_ostream<char>
-{
-public:
-    ostrstream();
-    ostrstream(char* s, int n, ios_base::openmode mode = ios_base::out);
-
-    virtual ~ostrstream();
-
-    strstreambuf* rdbuf() const;
-    void freeze(bool freezefl = true);
-    char* str();
-    int pcount() const;
-
-private:
-    strstreambuf sb; // exposition only
-};
-
-class strstream
-    : public basic_iostream<char>
-{
-public:
-    // Types
-    typedef char                        char_type;
-    typedef char_traits<char>::int_type int_type;
-    typedef char_traits<char>::pos_type pos_type;
-    typedef char_traits<char>::off_type off_type;
-
-    // constructors/destructor
-    strstream();
-    strstream(char* s, int n, ios_base::openmode mode = ios_base::in | ios_base::out);
-
-    virtual ~strstream();
-
-    // Members:
-    strstreambuf* rdbuf() const;
-    void freeze(bool freezefl = true);
-    int pcount() const;
-    char* str();
-
-private:
-    strstreambuf sb; // exposition only
-};
-
-}  // std
-
-*/
-
-#include <__config>
-#include <ostream>
-#include <istream>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-class _LIBCPP_TYPE_VIS strstreambuf
-    : public streambuf
-{
-public:
-    explicit strstreambuf(streamsize __alsize = 0);
-    strstreambuf(void* (*__palloc)(size_t), void (*__pfree)(void*));
-    strstreambuf(char* __gnext, streamsize __n, char* __pbeg = 0);
-    strstreambuf(const char* __gnext, streamsize __n);
-
-    strstreambuf(signed char* __gnext, streamsize __n, signed char* __pbeg = 0);
-    strstreambuf(const signed char* __gnext, streamsize __n);
-    strstreambuf(unsigned char* __gnext, streamsize __n, unsigned char* __pbeg = 0);
-    strstreambuf(const unsigned char* __gnext, streamsize __n);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    strstreambuf(strstreambuf&& __rhs);
-    _LIBCPP_INLINE_VISIBILITY
-    strstreambuf& operator=(strstreambuf&& __rhs);
-#endif  // _LIBCPP_CXX03_LANG
-
-    virtual ~strstreambuf();
-
-    void swap(strstreambuf& __rhs);
-
-    void freeze(bool __freezefl = true);
-    char* str();
-    int pcount() const;
-
-protected:
-    virtual int_type overflow (int_type __c = EOF);
-    virtual int_type pbackfail(int_type __c = EOF);
-    virtual int_type underflow();
-    virtual pos_type seekoff(off_type __off, ios_base::seekdir __way,
-                             ios_base::openmode __which = ios_base::in | ios_base::out);
-    virtual pos_type seekpos(pos_type __sp,
-                             ios_base::openmode __which = ios_base::in | ios_base::out);
-
-private:
-    typedef unsigned __mode_type;
-    static const __mode_type __allocated = 0x01;
-    static const __mode_type __constant  = 0x02;
-    static const __mode_type __dynamic   = 0x04;
-    static const __mode_type __frozen    = 0x08;
-    static const streamsize    __default_alsize = 4096;
-
-    __mode_type __strmode_;
-    streamsize __alsize_;
-    void* (*__palloc_)(size_t);
-    void (*__pfree_)(void*);
-
-    void __init(char* __gnext, streamsize __n, char* __pbeg);
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-inline _LIBCPP_INLINE_VISIBILITY
-strstreambuf::strstreambuf(strstreambuf&& __rhs)
-    : streambuf(__rhs),
-      __strmode_(__rhs.__strmode_),
-      __alsize_(__rhs.__alsize_),
-      __palloc_(__rhs.__palloc_),
-      __pfree_(__rhs.__pfree_)
-{
-    __rhs.setg(nullptr, nullptr, nullptr);
-    __rhs.setp(nullptr, nullptr);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-strstreambuf&
-strstreambuf::operator=(strstreambuf&& __rhs)
-{
-    if (eback() && (__strmode_ & __allocated) != 0 && (__strmode_ & __frozen) == 0)
-    {
-        if (__pfree_)
-            __pfree_(eback());
-        else
-            delete [] eback();
-    }
-    streambuf::operator=(__rhs);
-    __strmode_ = __rhs.__strmode_;
-    __alsize_ = __rhs.__alsize_;
-    __palloc_ = __rhs.__palloc_;
-    __pfree_ = __rhs.__pfree_;
-    __rhs.setg(nullptr, nullptr, nullptr);
-    __rhs.setp(nullptr, nullptr);
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-class _LIBCPP_TYPE_VIS istrstream
-    : public istream
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit istrstream(const char* __s)
-        : istream(&__sb_), __sb_(__s, 0) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit istrstream(char* __s)
-        : istream(&__sb_), __sb_(__s, 0) {}
-    _LIBCPP_INLINE_VISIBILITY
-    istrstream(const char* __s, streamsize __n)
-        : istream(&__sb_), __sb_(__s, __n) {}
-    _LIBCPP_INLINE_VISIBILITY
-    istrstream(char* __s, streamsize __n)
-        : istream(&__sb_), __sb_(__s, __n) {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    istrstream(istrstream&& __rhs)
-        : istream(_VSTD::move(__rhs)),
-          __sb_(_VSTD::move(__rhs.__sb_))
-    {
-        istream::set_rdbuf(&__sb_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    istrstream& operator=(istrstream&& __rhs)
-    {
-        istream::operator=(_VSTD::move(__rhs));
-        __sb_ = _VSTD::move(__rhs.__sb_);
-        return *this;
-    }
-#endif  // _LIBCPP_CXX03_LANG
-
-    virtual ~istrstream();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(istrstream& __rhs)
-    {
-        istream::swap(__rhs);
-        __sb_.swap(__rhs.__sb_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    strstreambuf* rdbuf() const {return const_cast<strstreambuf*>(&__sb_);}
-    _LIBCPP_INLINE_VISIBILITY
-    char *str() {return __sb_.str();}
-
-private:
-    strstreambuf __sb_;
-};
-
-class _LIBCPP_TYPE_VIS ostrstream
-    : public ostream
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    ostrstream()
-        : ostream(&__sb_) {}
-    _LIBCPP_INLINE_VISIBILITY
-    ostrstream(char* __s, int __n, ios_base::openmode __mode = ios_base::out)
-        : ostream(&__sb_),
-          __sb_(__s, __n, __s + (__mode & ios::app ? strlen(__s) : 0))
-        {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    ostrstream(ostrstream&& __rhs)
-        : ostream(_VSTD::move(__rhs)),
-          __sb_(_VSTD::move(__rhs.__sb_))
-    {
-        ostream::set_rdbuf(&__sb_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    ostrstream& operator=(ostrstream&& __rhs)
-    {
-        ostream::operator=(_VSTD::move(__rhs));
-        __sb_ = _VSTD::move(__rhs.__sb_);
-        return *this;
-    }
-#endif  // _LIBCPP_CXX03_LANG
-
-    virtual ~ostrstream();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(ostrstream& __rhs)
-    {
-        ostream::swap(__rhs);
-        __sb_.swap(__rhs.__sb_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    strstreambuf* rdbuf() const {return const_cast<strstreambuf*>(&__sb_);}
-    _LIBCPP_INLINE_VISIBILITY
-    void freeze(bool __freezefl = true) {__sb_.freeze(__freezefl);}
-    _LIBCPP_INLINE_VISIBILITY
-    char* str()         {return __sb_.str();}
-    _LIBCPP_INLINE_VISIBILITY
-    int pcount() const  {return __sb_.pcount();}
-
-private:
-    strstreambuf __sb_; // exposition only
-};
-
-class _LIBCPP_TYPE_VIS strstream
-    : public iostream
-{
-public:
-    // Types
-    typedef char                        char_type;
-    typedef char_traits<char>::int_type int_type;
-    typedef char_traits<char>::pos_type pos_type;
-    typedef char_traits<char>::off_type off_type;
-
-    // constructors/destructor
-    _LIBCPP_INLINE_VISIBILITY
-    strstream()
-        : iostream(&__sb_) {}
-    _LIBCPP_INLINE_VISIBILITY
-    strstream(char* __s, int __n, ios_base::openmode __mode = ios_base::in | ios_base::out)
-        : iostream(&__sb_),
-          __sb_(__s, __n, __s + (__mode & ios::app ? strlen(__s) : 0))
-        {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    strstream(strstream&& __rhs)
-        : iostream(_VSTD::move(__rhs)),
-          __sb_(_VSTD::move(__rhs.__sb_))
-    {
-        iostream::set_rdbuf(&__sb_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    strstream& operator=(strstream&& __rhs)
-    {
-        iostream::operator=(_VSTD::move(__rhs));
-        __sb_ = _VSTD::move(__rhs.__sb_);
-        return *this;
-    }
-#endif  // _LIBCPP_CXX03_LANG
-
-    virtual ~strstream();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(strstream& __rhs)
-    {
-        iostream::swap(__rhs);
-        __sb_.swap(__rhs.__sb_);
-    }
-
-    // Members:
-    _LIBCPP_INLINE_VISIBILITY
-    strstreambuf* rdbuf() const {return const_cast<strstreambuf*>(&__sb_);}
-    _LIBCPP_INLINE_VISIBILITY
-    void freeze(bool __freezefl = true) {__sb_.freeze(__freezefl);}
-    _LIBCPP_INLINE_VISIBILITY
-    int pcount() const {return __sb_.pcount();}
-    _LIBCPP_INLINE_VISIBILITY
-    char* str()        {return __sb_.str();}
-
-private:
-    strstreambuf __sb_; // exposition only
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_STRSTREAM
diff --git a/lib/libcxx/include/support/android/locale_bionic.h b/lib/libcxx/include/support/android/locale_bionic.h
deleted file mode 100644
index 50fcf5c36a7..00000000000
--- a/lib/libcxx/include/support/android/locale_bionic.h
+++ /dev/null
@@ -1,68 +0,0 @@
-// -*- C++ -*-
-//===------------------- support/android/locale_bionic.h ------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_ANDROID_LOCALE_BIONIC_H
-#define _LIBCPP_SUPPORT_ANDROID_LOCALE_BIONIC_H
-
-#if defined(__BIONIC__)
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#include <stdlib.h>
-#include <xlocale.h>
-
-#ifdef __cplusplus
-}
-#endif
-
-#if defined(__ANDROID__)
-
-#include <android/api-level.h>
-#include <android/ndk-version.h>
-#include <support/xlocale/__posix_l_fallback.h>
-// In NDK versions later than 16, locale-aware functions are provided by
-// legacy_stdlib_inlines.h
-#if __NDK_MAJOR__ <= 16
-#if __ANDROID_API__ < 21
-#include <support/xlocale/__strtonum_fallback.h>
-#elif __ANDROID_API__ < 26
-
-#if defined(__cplusplus)
-extern "C" {
-#endif
-
-inline _LIBCPP_INLINE_VISIBILITY float strtof_l(const char* __nptr, char** __endptr,
-                                                locale_t) {
-  return ::strtof(__nptr, __endptr);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY double strtod_l(const char* __nptr,
-                                                 char** __endptr, locale_t) {
-  return ::strtod(__nptr, __endptr);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY long strtol_l(const char* __nptr, char** __endptr,
-                                               int __base, locale_t) {
-  return ::strtol(__nptr, __endptr, __base);
-}
-
-#if defined(__cplusplus)
-}
-#endif
-
-#endif // __ANDROID_API__ < 26
-
-#endif // __NDK_MAJOR__ <= 16
-#endif // defined(__ANDROID__)
-
-#endif // defined(__BIONIC__)
-#endif // _LIBCPP_SUPPORT_ANDROID_LOCALE_BIONIC_H
diff --git a/lib/libcxx/include/support/fuchsia/xlocale.h b/lib/libcxx/include/support/fuchsia/xlocale.h
deleted file mode 100644
index 1de2fca28e2..00000000000
--- a/lib/libcxx/include/support/fuchsia/xlocale.h
+++ /dev/null
@@ -1,23 +0,0 @@
-// -*- C++ -*-
-//===------------------- support/fuchsia/xlocale.h ------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_FUCHSIA_XLOCALE_H
-#define _LIBCPP_SUPPORT_FUCHSIA_XLOCALE_H
-
-#if defined(__Fuchsia__)
-
-#include <cstdlib>
-#include <cwchar>
-#include <support/xlocale/__posix_l_fallback.h>
-#include <support/xlocale/__strtonum_fallback.h>
-
-#endif // defined(__Fuchsia__)
-
-#endif // _LIBCPP_SUPPORT_FUCHSIA_XLOCALE_H
diff --git a/lib/libcxx/include/support/ibm/limits.h b/lib/libcxx/include/support/ibm/limits.h
deleted file mode 100644
index efdb3596596..00000000000
--- a/lib/libcxx/include/support/ibm/limits.h
+++ /dev/null
@@ -1,99 +0,0 @@
-// -*- C++ -*-
-//===--------------------- support/ibm/limits.h ---------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_IBM_LIMITS_H
-#define _LIBCPP_SUPPORT_IBM_LIMITS_H
-
-#if !defined(_AIX) // Linux
-#include <math.h> // for HUGE_VAL, HUGE_VALF, HUGE_VALL, and NAN
-
-static const unsigned int _QNAN_F = 0x7fc00000;
-#define NANF (*((float *)(&_QNAN_F)))
-static const unsigned int _QNAN_LDBL128[4] = {0x7ff80000, 0x0, 0x0, 0x0};
-#define NANL (*((long double *)(&_QNAN_LDBL128)))
-static const unsigned int _SNAN_F= 0x7f855555;
-#define NANSF (*((float *)(&_SNAN_F)))
-static const unsigned int _SNAN_D[2] = {0x7ff55555, 0x55555555};
-#define NANS (*((double *)(&_SNAN_D)))
-static const unsigned int _SNAN_LDBL128[4] = {0x7ff55555, 0x55555555, 0x0, 0x0};
-#define NANSL (*((long double *)(&_SNAN_LDBL128)))
-
-#define __builtin_huge_val()     HUGE_VAL
-#define __builtin_huge_valf()    HUGE_VALF
-#define __builtin_huge_vall()    HUGE_VALL
-#define __builtin_nan(__dummy)   NAN
-#define __builtin_nanf(__dummy)  NANF
-#define __builtin_nanl(__dummy)  NANL
-#define __builtin_nans(__dummy)  NANS
-#define __builtin_nansf(__dummy) NANSF
-#define __builtin_nansl(__dummy) NANSL
-
-#else
-
-#include <math.h>
-#include <float.h> // limit constants
-
-#define __builtin_huge_val()     HUGE_VAL  //0x7ff0000000000000
-#define __builtin_huge_valf()    HUGE_VALF //0x7f800000
-#define __builtin_huge_vall()    HUGE_VALL //0x7ff0000000000000
-#define __builtin_nan(__dummy)   nan(__dummy) //0x7ff8000000000000
-#define __builtin_nanf(__dummy)  nanf(__dummy) // 0x7ff80000
-#define __builtin_nanl(__dummy)  nanl(__dummy) //0x7ff8000000000000
-#define __builtin_nans(__dummy)  DBL_SNAN //0x7ff5555555555555
-#define __builtin_nansf(__dummy) FLT_SNAN //0x7f855555
-#define __builtin_nansl(__dummy) DBL_SNAN //0x7ff5555555555555
-
-#define __FLT_MANT_DIG__   FLT_MANT_DIG
-#define __FLT_DIG__        FLT_DIG
-#define __FLT_RADIX__      FLT_RADIX
-#define __FLT_MIN_EXP__    FLT_MIN_EXP
-#define __FLT_MIN_10_EXP__ FLT_MIN_10_EXP
-#define __FLT_MAX_EXP__    FLT_MAX_EXP
-#define __FLT_MAX_10_EXP__ FLT_MAX_10_EXP
-#define __FLT_MIN__        FLT_MIN
-#define __FLT_MAX__        FLT_MAX
-#define __FLT_EPSILON__    FLT_EPSILON
-// predefined by XLC on LoP
-#define __FLT_DENORM_MIN__ 1.40129846e-45F
-
-#define __DBL_MANT_DIG__   DBL_MANT_DIG
-#define __DBL_DIG__        DBL_DIG
-#define __DBL_MIN_EXP__    DBL_MIN_EXP
-#define __DBL_MIN_10_EXP__ DBL_MIN_10_EXP
-#define __DBL_MAX_EXP__    DBL_MAX_EXP
-#define __DBL_MAX_10_EXP__ DBL_MAX_10_EXP
-#define __DBL_MIN__        DBL_MIN
-#define __DBL_MAX__        DBL_MAX
-#define __DBL_EPSILON__    DBL_EPSILON
-// predefined by XLC on LoP
-#define __DBL_DENORM_MIN__ 4.9406564584124654e-324
-
-#define __LDBL_MANT_DIG__   LDBL_MANT_DIG
-#define __LDBL_DIG__        LDBL_DIG
-#define __LDBL_MIN_EXP__    LDBL_MIN_EXP
-#define __LDBL_MIN_10_EXP__ LDBL_MIN_10_EXP
-#define __LDBL_MAX_EXP__    LDBL_MAX_EXP
-#define __LDBL_MAX_10_EXP__ LDBL_MAX_10_EXP
-#define __LDBL_MIN__        LDBL_MIN
-#define __LDBL_MAX__        LDBL_MAX
-#define __LDBL_EPSILON__    LDBL_EPSILON
-// predefined by XLC on LoP
-#if __LONGDOUBLE128
-#define __LDBL_DENORM_MIN__ 4.94065645841246544176568792868221e-324L
-#else
-#define __LDBL_DENORM_MIN__ 4.9406564584124654e-324L
-#endif
-
-// predefined by XLC on LoP
-#define __CHAR_BIT__    8
-
-#endif // _AIX
-
-#endif // _LIBCPP_SUPPORT_IBM_LIMITS_H
diff --git a/lib/libcxx/include/support/ibm/locale_mgmt_aix.h b/lib/libcxx/include/support/ibm/locale_mgmt_aix.h
deleted file mode 100644
index e3b7a78c45a..00000000000
--- a/lib/libcxx/include/support/ibm/locale_mgmt_aix.h
+++ /dev/null
@@ -1,85 +0,0 @@
-// -*- C++ -*-
-//===------------------- support/ibm/locale_mgmt_aix.h --------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_IBM_LOCALE_MGMT_AIX_H
-#define _LIBCPP_SUPPORT_IBM_LOCALE_MGMT_AIX_H
-
-#if defined(_AIX)
-#include "cstdlib"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#if !defined(_AIX71)
-// AIX 7.1 and higher has these definitions.  Definitions and stubs
-// are provied here as a temporary workaround on AIX 6.1.
-
-#define LC_COLLATE_MASK         1
-#define LC_CTYPE_MASK           2
-#define LC_MESSAGES_MASK        4
-#define LC_MONETARY_MASK        8
-#define LC_NUMERIC_MASK         16
-#define LC_TIME_MASK            32
-#define LC_ALL_MASK             (LC_COLLATE_MASK | LC_CTYPE_MASK | \
-                                 LC_MESSAGES_MASK | LC_MONETARY_MASK |\
-                                 LC_NUMERIC_MASK | LC_TIME_MASK)
-
-typedef void* locale_t;
-
-// The following are stubs.  They are not supported on AIX 6.1.
-static inline
-locale_t newlocale(int category_mask, const char *locale, locale_t base)
-{
-  _LC_locale_t *newloc, *loc;
-  if ((loc = (_LC_locale_t *)__xopen_locale(locale)) == NULL)
-  {
-    errno = EINVAL;
-    return (locale_t)0;
-  }
-  if ((newloc = (_LC_locale_t *)calloc(1, sizeof(_LC_locale_t))) == NULL)
-  {
-    errno = ENOMEM;
-    return (locale_t)0;
-  }
-  if (!base)
-    base = (_LC_locale_t *)__xopen_locale("C");
-  memcpy(newloc, base, sizeof (_LC_locale_t));
-  if (category_mask & LC_COLLATE_MASK)
-    newloc->lc_collate = loc->lc_collate;
-  if (category_mask & LC_CTYPE_MASK)
-    newloc->lc_ctype = loc->lc_ctype;
-  //if (category_mask & LC_MESSAGES_MASK)
-  //  newloc->lc_messages = loc->lc_messages;
-  if (category_mask & LC_MONETARY_MASK)
-    newloc->lc_monetary = loc->lc_monetary;
-  if (category_mask & LC_TIME_MASK)
-    newloc->lc_time = loc->lc_time;
-  if (category_mask & LC_NUMERIC_MASK)
-    newloc->lc_numeric = loc->lc_numeric;
-  return (locale_t)newloc;
-}
-static inline
-void freelocale(locale_t locobj)
-{
-  free(locobj);
-}
-static inline
-locale_t uselocale(locale_t newloc)
-{
-  return (locale_t)0;
-}
-#endif // !defined(_AIX71)
-
-#ifdef __cplusplus
-}
-#endif
-#endif // defined(_AIX)
-#endif // _LIBCPP_SUPPORT_IBM_LOCALE_MGMT_AIX_H
diff --git a/lib/libcxx/include/support/ibm/support.h b/lib/libcxx/include/support/ibm/support.h
deleted file mode 100644
index 0abfa7f95a6..00000000000
--- a/lib/libcxx/include/support/ibm/support.h
+++ /dev/null
@@ -1,54 +0,0 @@
-// -*- C++ -*-
-//===----------------------- support/ibm/support.h ----------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_IBM_SUPPORT_H
-#define _LIBCPP_SUPPORT_IBM_SUPPORT_H
-
-extern "builtin" int __popcnt4(unsigned int);
-extern "builtin" int __popcnt8(unsigned long long);
-extern "builtin" unsigned int __cnttz4(unsigned int);
-extern "builtin" unsigned int __cnttz8(unsigned long long);
-extern "builtin" unsigned int __cntlz4(unsigned int);
-extern "builtin" unsigned int __cntlz8(unsigned long long);
-
-// Builtin functions for counting population
-#define __builtin_popcount(x) __popcnt4(x)
-#define __builtin_popcountll(x) __popcnt8(x)
-#if defined(__64BIT__)
-#define __builtin_popcountl(x) __builtin_popcountll(x)
-#else
-#define __builtin_popcountl(x) __builtin_popcount(x)
-#endif
-
-// Builtin functions for counting trailing zeros
-#define __builtin_ctz(x) __cnttz4(x)
-#define __builtin_ctzll(x) __cnttz8(x)
-#if defined(__64BIT__)
-#define __builtin_ctzl(x) __builtin_ctzll(x)
-#else
-#define __builtin_ctzl(x) __builtin_ctz(x)
-#endif
-
-// Builtin functions for counting leading zeros
-#define __builtin_clz(x) __cntlz4(x)
-#define __builtin_clzll(x) __cntlz8(x)
-#if defined(__64BIT__)
-#define __builtin_clzl(x) __builtin_clzll(x)
-#else
-#define __builtin_clzl(x) __builtin_clz(x)
-#endif
-
-#if defined(__64BIT__)
-#define __SIZE_WIDTH__ 64
-#else
-#define __SIZE_WIDTH__ 32
-#endif
-
-#endif // _LIBCPP_SUPPORT_IBM_SUPPORT_H
diff --git a/lib/libcxx/include/support/ibm/xlocale.h b/lib/libcxx/include/support/ibm/xlocale.h
deleted file mode 100644
index f39c0ba95d9..00000000000
--- a/lib/libcxx/include/support/ibm/xlocale.h
+++ /dev/null
@@ -1,271 +0,0 @@
-// -*- C++ -*-
-//===--------------------- support/ibm/xlocale.h -------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_IBM_XLOCALE_H
-#define _LIBCPP_SUPPORT_IBM_XLOCALE_H
-#include <support/ibm/locale_mgmt_aix.h>
-
-#if defined(_AIX)
-#include "cstdlib"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#if !defined(_AIX71)
-// AIX 7.1 and higher has these definitions.  Definitions and stubs
-// are provied here as a temporary workaround on AIX 6.1.
-static inline
-int isalnum_l(int c, locale_t locale)
-{
-  return __xisalnum(locale, c);
-}
-static inline
-int isalpha_l(int c, locale_t locale)
-{
-  return __xisalpha(locale, c);
-}
-static inline
-int isblank_l(int c, locale_t locale)
-{
-  return __xisblank(locale, c);
-}
-static inline
-int iscntrl_l(int c, locale_t locale)
-{
-  return __xiscntrl(locale, c);
-}
-static inline
-int isdigit_l(int c, locale_t locale)
-{
-  return __xisdigit(locale, c);
-}
-static inline
-int isgraph_l(int c, locale_t locale)
-{
-  return __xisgraph(locale, c);
-}
-static inline
-int islower_l(int c, locale_t locale)
-{
-  return __xislower(locale, c);
-}
-static inline
-int isprint_l(int c, locale_t locale)
-{
-  return __xisprint(locale, c);
-}
-
-static inline
-int ispunct_l(int c, locale_t locale)
-{
-  return __xispunct(locale, c);
-}
-static inline
-int isspace_l(int c, locale_t locale)
-{
-  return __xisspace(locale, c);
-}
-static inline
-int isupper_l(int c, locale_t locale)
-{
-  return __xisupper(locale, c);
-}
-
-static inline
-int isxdigit_l(int c, locale_t locale)
-{
-  return __xisxdigit(locale, c);
-}
-
-static inline
-int iswalnum_l(wchar_t wc, locale_t locale)
-{
-  return __xiswalnum(locale, wc); 
-}
-
-static inline
-int iswalpha_l(wchar_t wc, locale_t locale)
-{
-  return __xiswalpha(locale, wc);
-}
-
-static inline
-int iswblank_l(wchar_t wc, locale_t locale)
-{
-  return __xiswblank(locale, wc);
-}
-
-static inline
-int iswcntrl_l(wchar_t wc, locale_t locale)
-{
-  return __xiswcntrl(locale, wc);
-}
-
-static inline
-int iswdigit_l(wchar_t wc, locale_t locale)
-{
-  return __xiswdigit(locale, wc);
-}
-
-static inline
-int iswgraph_l(wchar_t wc, locale_t locale)
-{
-  return __xiswgraph(locale, wc);
-}
-
-static inline
-int iswlower_l(wchar_t wc, locale_t locale)
-{
-  return __xiswlower(locale, wc);
-}
-
-static inline
-int iswprint_l(wchar_t wc, locale_t locale)
-{
-  return __xiswprint(locale, wc);
-}
-
-static inline
-int iswpunct_l(wchar_t wc, locale_t locale)
-{
-  return __xiswpunct(locale, wc);
-}
-
-static inline
-int iswspace_l(wchar_t wc, locale_t locale)
-{
-  return __xiswspace(locale, wc);
-}
-
-static inline
-int iswupper_l(wchar_t wc, locale_t locale)
-{
-  return __xiswupper(locale, wc);
-}
-
-static inline
-int iswxdigit_l(wchar_t wc, locale_t locale)
-{
-  return __xiswxdigit(locale, wc);
-}
-
-static inline
-int iswctype_l(wint_t wc, wctype_t desc, locale_t locale)
-{
-  return __xiswctype(locale, wc, desc); 
-}
-
-static inline
-int toupper_l(int c, locale_t locale)
-{
-  return __xtoupper(locale, c);
-}
-static inline
-int tolower_l(int c, locale_t locale)
-{
-  return __xtolower(locale, c);
-}
-static inline
-wint_t towupper_l(wint_t wc, locale_t locale)
-{
-  return __xtowupper(locale, wc);
-}
-static inline
-wint_t towlower_l(wint_t wc, locale_t locale)
-{
-  return __xtowlower(locale, wc);
-}
-
-static inline
-int strcoll_l(const char *__s1, const char *__s2, locale_t locale)
-{
-  return __xstrcoll(locale, __s1, __s2);
-}
-static inline
-int wcscoll_l(const wchar_t *__s1, const wchar_t *__s2, locale_t locale)
-{
-  return __xwcscoll(locale, __s1, __s2);
-}
-static inline
-size_t strxfrm_l(char *__s1, const char *__s2, size_t __n, locale_t locale)
-{
-  return __xstrxfrm(locale, __s1, __s2, __n);
-}
-
-static inline
-size_t wcsxfrm_l(wchar_t *__ws1, const wchar_t *__ws2, size_t __n,
-    locale_t locale)
-{
-  return __xwcsxfrm(locale, __ws1, __ws2, __n);
-}
-#endif // !defined(_AIX71)
-
-// strftime_l() is defined by POSIX. However, AIX 7.1 does not have it
-// implemented yet.
-static inline
-size_t strftime_l(char *__s, size_t __size, const char *__fmt,
-                  const struct tm *__tm, locale_t locale) {
-  return __xstrftime(locale, __s, __size, __fmt, __tm);
-}
-
-// The following are not POSIX routines.  These are quick-and-dirty hacks
-// to make things pretend to work
-static inline
-long long strtoll_l(const char *__nptr, char **__endptr,
-    int __base, locale_t locale) {
-  return strtoll(__nptr, __endptr, __base);
-}
-static inline
-long strtol_l(const char *__nptr, char **__endptr,
-    int __base, locale_t locale) {
-  return strtol(__nptr, __endptr, __base);
-}
-static inline
-long double strtold_l(const char *__nptr, char **__endptr,
-    locale_t locale) {
-  return strtold(__nptr, __endptr);
-}
-static inline
-unsigned long long strtoull_l(const char *__nptr, char **__endptr,
-    int __base, locale_t locale) {
-  return strtoull(__nptr, __endptr, __base);
-}
-static inline
-unsigned long strtoul_l(const char *__nptr, char **__endptr,
-    int __base, locale_t locale) {
-  return strtoul(__nptr, __endptr, __base);
-}
-
-static inline
-int vasprintf(char **strp, const char *fmt, va_list ap)
-{
-  const size_t buff_size = 256;
-  int str_size;
-  if ((*strp = (char *)malloc(buff_size)) == NULL)
-  {
-    return -1;
-  }
-  if ((str_size = vsnprintf(*strp, buff_size, fmt,  ap)) >= buff_size)
-  {
-    if ((*strp = (char *)realloc(*strp, str_size + 1)) == NULL)
-    {
-      return -1;
-    }
-    str_size = vsnprintf(*strp, str_size + 1, fmt,  ap);
-  }
-  return str_size;
-}  
-
-#ifdef __cplusplus
-}
-#endif
-#endif // defined(_AIX)
-#endif // _LIBCPP_SUPPORT_IBM_XLOCALE_H
diff --git a/lib/libcxx/include/support/musl/xlocale.h b/lib/libcxx/include/support/musl/xlocale.h
deleted file mode 100644
index 3e31c99596c..00000000000
--- a/lib/libcxx/include/support/musl/xlocale.h
+++ /dev/null
@@ -1,58 +0,0 @@
-// -*- C++ -*-
-//===------------------- support/musl/xlocale.h ------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-// This adds support for the extended locale functions that are currently
-// missing from the Musl C library.
-//
-// This only works when the specified locale is "C" or "POSIX", but that's
-// about as good as we can do without implementing full xlocale support
-// in Musl.
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_MUSL_XLOCALE_H
-#define _LIBCPP_SUPPORT_MUSL_XLOCALE_H
-
-#include <cstdlib>
-#include <cwchar>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-static inline long long strtoll_l(const char *nptr, char **endptr, int base,
-                                  locale_t) {
-  return strtoll(nptr, endptr, base);
-}
-
-static inline unsigned long long strtoull_l(const char *nptr, char **endptr,
-                                            int base, locale_t) {
-  return strtoull(nptr, endptr, base);
-}
-
-static inline long long wcstoll_l(const wchar_t *nptr, wchar_t **endptr,
-                                  int base, locale_t) {
-  return wcstoll(nptr, endptr, base);
-}
-
-static inline unsigned long long wcstoull_l(const wchar_t *nptr,
-                                            wchar_t **endptr, int base,
-                                            locale_t) {
-  return wcstoull(nptr, endptr, base);
-}
-
-static inline long double wcstold_l(const wchar_t *nptr, wchar_t **endptr,
-                                    locale_t) {
-  return wcstold(nptr, endptr);
-}
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif // _LIBCPP_SUPPORT_MUSL_XLOCALE_H
diff --git a/lib/libcxx/include/support/newlib/xlocale.h b/lib/libcxx/include/support/newlib/xlocale.h
deleted file mode 100644
index 2ce6438b556..00000000000
--- a/lib/libcxx/include/support/newlib/xlocale.h
+++ /dev/null
@@ -1,30 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_NEWLIB_XLOCALE_H
-#define _LIBCPP_SUPPORT_NEWLIB_XLOCALE_H
-
-#if defined(_NEWLIB_VERSION) || defined(__OpenBSD__)
-
-#include <cstdlib>
-#include <clocale>
-#include <cwctype>
-#include <ctype.h>
-#if !defined(__OpenBSD__)
-#if !defined(__NEWLIB__) || __NEWLIB__ < 2 || \
-    __NEWLIB__ == 2 && __NEWLIB_MINOR__ < 5
-#include <support/xlocale/__nop_locale_mgmt.h>
-#include <support/xlocale/__posix_l_fallback.h>
-#endif
-#endif
-#include <support/xlocale/__strtonum_fallback.h>
-
-#endif // _NEWLIB_VERSION
-
-#endif
diff --git a/lib/libcxx/include/support/solaris/floatingpoint.h b/lib/libcxx/include/support/solaris/floatingpoint.h
deleted file mode 100644
index 999d144b1f2..00000000000
--- a/lib/libcxx/include/support/solaris/floatingpoint.h
+++ /dev/null
@@ -1,14 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#define atof sun_atof
-#define strtod sun_strtod
-#include_next "floatingpoint.h"
-#undef atof
-#undef strtod
diff --git a/lib/libcxx/include/support/solaris/wchar.h b/lib/libcxx/include/support/solaris/wchar.h
deleted file mode 100644
index 0e8e660c8bd..00000000000
--- a/lib/libcxx/include/support/solaris/wchar.h
+++ /dev/null
@@ -1,47 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#define iswalpha sun_iswalpha
-#define iswupper sun_iswupper
-#define iswlower sun_iswlower
-#define iswdigit sun_iswdigit
-#define iswxdigit sun_iswxdigit
-#define iswalnum sun_iswalnum
-#define iswspace sun_iswspace
-#define iswpunct sun_iswpunct
-#define iswprint sun_iswprint
-#define iswgraph sun_iswgraph
-#define iswcntrl sun_iswcntrl
-#define iswctype sun_iswctype
-#define towlower sun_towlower
-#define towupper sun_towupper
-#define wcswcs sun_wcswcs
-#define wcswidth sun_wcswidth
-#define wcwidth sun_wcwidth
-#define wctype sun_wctype
-#define _WCHAR_T 1
-#include_next "wchar.h"
-#undef iswalpha 
-#undef iswupper
-#undef iswlower
-#undef iswdigit
-#undef iswxdigit
-#undef iswalnum
-#undef iswspace
-#undef iswpunct
-#undef iswprint
-#undef iswgraph
-#undef iswcntrl
-#undef iswctype
-#undef towlower
-#undef towupper
-#undef wcswcs
-#undef wcswidth
-#undef wcwidth
-#undef wctype
diff --git a/lib/libcxx/include/support/solaris/xlocale.h b/lib/libcxx/include/support/solaris/xlocale.h
deleted file mode 100644
index e20ef7a6e53..00000000000
--- a/lib/libcxx/include/support/solaris/xlocale.h
+++ /dev/null
@@ -1,77 +0,0 @@
-//===----------------------------------------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-////////////////////////////////////////////////////////////////////////////////
-// Minimal xlocale implementation for Solaris.  This implements the subset of
-// the xlocale APIs that libc++ depends on.
-////////////////////////////////////////////////////////////////////////////////
-#ifndef __XLOCALE_H_INCLUDED
-#define __XLOCALE_H_INCLUDED
-
-#include <stdlib.h>
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-
-int snprintf_l(char *__s, size_t __n, locale_t __l, const char *__format, ...);
-int asprintf_l(char **__s, locale_t __l, const char *__format, ...);
-
-int sscanf_l(const char *__s, locale_t __l, const char *__format, ...);
-
-int toupper_l(int __c, locale_t __l);
-int tolower_l(int __c, locale_t __l);
-
-struct lconv *localeconv(void);
-struct lconv *localeconv_l(locale_t __l);
-
-// FIXME: These are quick-and-dirty hacks to make things pretend to work
-static inline
-long long strtoll_l(const char *__nptr, char **__endptr,
-    int __base, locale_t __loc) {
-  return strtoll(__nptr, __endptr, __base);
-}
-static inline
-long strtol_l(const char *__nptr, char **__endptr,
-    int __base, locale_t __loc) {
-  return strtol(__nptr, __endptr, __base);
-}
-static inline
-unsigned long long strtoull_l(const char *__nptr, char **__endptr,
-    int __base, locale_t __loc) {
-  return strtoull(__nptr, __endptr, __base);
-}
-static inline
-unsigned long strtoul_l(const char *__nptr, char **__endptr,
-    int __base, locale_t __loc) {
-  return strtoul(__nptr, __endptr, __base);
-}
-static inline
-float strtof_l(const char *__nptr, char **__endptr,
-    locale_t __loc) {
-  return strtof(__nptr, __endptr);
-}
-static inline
-double strtod_l(const char *__nptr, char **__endptr,
-    locale_t __loc) {
-  return strtod(__nptr, __endptr);
-}
-static inline
-long double strtold_l(const char *__nptr, char **__endptr,
-    locale_t __loc) {
-  return strtold(__nptr, __endptr);
-}
-
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif
diff --git a/lib/libcxx/include/support/win32/limits_msvc_win32.h b/lib/libcxx/include/support/win32/limits_msvc_win32.h
deleted file mode 100644
index 1ab2e0b6dc1..00000000000
--- a/lib/libcxx/include/support/win32/limits_msvc_win32.h
+++ /dev/null
@@ -1,72 +0,0 @@
-// -*- C++ -*-
-//===------------------ support/win32/limits_msvc_win32.h -----------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_WIN32_LIMITS_MSVC_WIN32_H
-#define _LIBCPP_SUPPORT_WIN32_LIMITS_MSVC_WIN32_H
-
-#if !defined(_LIBCPP_MSVCRT)
-#error "This header complements the Microsoft C Runtime library, and should not be included otherwise."
-#endif
-#if defined(__clang__)
-#error "This header should only be included when using Microsofts C1XX frontend"
-#endif
-
-#include <limits.h> // CHAR_BIT
-#include <float.h> // limit constants
-#include <math.h> // HUGE_VAL
-#include <ymath.h> // internal MSVC header providing the needed functionality
-
-#define __CHAR_BIT__       CHAR_BIT
-
-#define __FLT_MANT_DIG__   FLT_MANT_DIG
-#define __FLT_DIG__        FLT_DIG
-#define __FLT_RADIX__      FLT_RADIX
-#define __FLT_MIN_EXP__    FLT_MIN_EXP
-#define __FLT_MIN_10_EXP__ FLT_MIN_10_EXP
-#define __FLT_MAX_EXP__    FLT_MAX_EXP
-#define __FLT_MAX_10_EXP__ FLT_MAX_10_EXP
-#define __FLT_MIN__        FLT_MIN
-#define __FLT_MAX__        FLT_MAX
-#define __FLT_EPSILON__    FLT_EPSILON
-// predefined by MinGW GCC
-#define __FLT_DENORM_MIN__ 1.40129846432481707092e-45F
-
-#define __DBL_MANT_DIG__   DBL_MANT_DIG
-#define __DBL_DIG__        DBL_DIG
-#define __DBL_RADIX__      DBL_RADIX
-#define __DBL_MIN_EXP__    DBL_MIN_EXP
-#define __DBL_MIN_10_EXP__ DBL_MIN_10_EXP
-#define __DBL_MAX_EXP__    DBL_MAX_EXP
-#define __DBL_MAX_10_EXP__ DBL_MAX_10_EXP
-#define __DBL_MIN__        DBL_MIN
-#define __DBL_MAX__        DBL_MAX
-#define __DBL_EPSILON__    DBL_EPSILON
-// predefined by MinGW GCC
-#define __DBL_DENORM_MIN__ double(4.94065645841246544177e-324L)
-
-#define __LDBL_MANT_DIG__   LDBL_MANT_DIG
-#define __LDBL_DIG__        LDBL_DIG
-#define __LDBL_RADIX__      LDBL_RADIX
-#define __LDBL_MIN_EXP__    LDBL_MIN_EXP
-#define __LDBL_MIN_10_EXP__ LDBL_MIN_10_EXP
-#define __LDBL_MAX_EXP__    LDBL_MAX_EXP
-#define __LDBL_MAX_10_EXP__ LDBL_MAX_10_EXP
-#define __LDBL_MIN__        LDBL_MIN
-#define __LDBL_MAX__        LDBL_MAX
-#define __LDBL_EPSILON__    LDBL_EPSILON
-// predefined by MinGW GCC
-#define __LDBL_DENORM_MIN__ 3.64519953188247460253e-4951L
-
-// __builtin replacements/workarounds
-#define __builtin_huge_vall()    _LInf._Long_double
-#define __builtin_nanl(__dummmy) _LNan._Long_double
-#define __builtin_nansl(__dummy) _LSnan._Long_double
-
-#endif // _LIBCPP_SUPPORT_WIN32_LIMITS_MSVC_WIN32_H
diff --git a/lib/libcxx/include/support/win32/locale_win32.h b/lib/libcxx/include/support/win32/locale_win32.h
deleted file mode 100644
index c7c6d786cb8..00000000000
--- a/lib/libcxx/include/support/win32/locale_win32.h
+++ /dev/null
@@ -1,199 +0,0 @@
-// -*- C++ -*-
-//===--------------------- support/win32/locale_win32.h -------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H
-#define _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H
-
-#include <__config>
-#include <stdio.h>
-#include <xlocinfo.h> // _locale_t
-#include <__nullptr>
-
-#define LC_COLLATE_MASK _M_COLLATE
-#define LC_CTYPE_MASK _M_CTYPE
-#define LC_MONETARY_MASK _M_MONETARY
-#define LC_NUMERIC_MASK _M_NUMERIC
-#define LC_TIME_MASK _M_TIME
-#define LC_MESSAGES_MASK _M_MESSAGES
-#define LC_ALL_MASK (  LC_COLLATE_MASK \
-                     | LC_CTYPE_MASK \
-                     | LC_MESSAGES_MASK \
-                     | LC_MONETARY_MASK \
-                     | LC_NUMERIC_MASK \
-                     | LC_TIME_MASK )
-
-class locale_t {
-public:
-    locale_t()
-        : __locale(nullptr), __locale_str(nullptr) {}
-    locale_t(std::nullptr_t)
-        : __locale(nullptr), __locale_str(nullptr) {}
-    locale_t(_locale_t __xlocale, const char* __xlocale_str)
-        : __locale(__xlocale), __locale_str(__xlocale_str) {}
-
-    friend bool operator==(const locale_t& __left, const locale_t& __right) {
-        return __left.__locale == __right.__locale;
-    }
-
-    friend bool operator==(const locale_t& __left, int __right) {
-        return __left.__locale == nullptr && __right == 0;
-    }
-
-    friend bool operator==(const locale_t& __left, long long __right) {
-        return __left.__locale == nullptr && __right == 0;
-    }
-
-    friend bool operator==(const locale_t& __left, std::nullptr_t) {
-        return __left.__locale == nullptr;
-    }
-
-    friend bool operator==(int __left, const locale_t& __right) {
-        return __left == 0 && nullptr == __right.__locale;
-    }
-
-    friend bool operator==(std::nullptr_t, const locale_t& __right) {
-        return nullptr == __right.__locale;
-    }
-
-    friend bool operator!=(const locale_t& __left, const locale_t& __right) {
-        return !(__left == __right);
-    }
-
-    friend bool operator!=(const locale_t& __left, int __right) {
-        return !(__left == __right);
-    }
-
-    friend bool operator!=(const locale_t& __left, long long __right) {
-        return !(__left == __right);
-    }
-
-    friend bool operator!=(const locale_t& __left, std::nullptr_t __right) {
-        return !(__left == __right);
-    }
-
-    friend bool operator!=(int __left, const locale_t& __right) {
-        return !(__left == __right);
-    }
-
-    friend bool operator!=(std::nullptr_t __left, const locale_t& __right) {
-        return !(__left == __right);
-    }
-
-    operator bool() const {
-        return __locale != nullptr;
-    }
-
-    const char* __get_locale() const { return __locale_str; }
-
-    operator _locale_t() const {
-        return __locale;
-    }
-private:
-    _locale_t __locale;
-    const char* __locale_str;
-};
-
-// Locale management functions
-#define freelocale _free_locale
-// FIXME: base currently unused. Needs manual work to construct the new locale
-locale_t newlocale( int mask, const char * locale, locale_t base );
-// uselocale can't be implemented on Windows because Windows allows partial modification
-// of thread-local locale and so _get_current_locale() returns a copy while uselocale does
-// not create any copies.
-// We can still implement raii even without uselocale though.
-
-
-lconv *localeconv_l( locale_t loc );
-size_t mbrlen_l( const char *__restrict s, size_t n,
-                 mbstate_t *__restrict ps, locale_t loc);
-size_t mbsrtowcs_l( wchar_t *__restrict dst, const char **__restrict src,
-                    size_t len, mbstate_t *__restrict ps, locale_t loc );
-size_t wcrtomb_l( char *__restrict s, wchar_t wc, mbstate_t *__restrict ps,
-                  locale_t loc);
-size_t mbrtowc_l( wchar_t *__restrict pwc, const char *__restrict s,
-                  size_t n, mbstate_t *__restrict ps, locale_t loc);
-size_t mbsnrtowcs_l( wchar_t *__restrict dst, const char **__restrict src,
-                     size_t nms, size_t len, mbstate_t *__restrict ps, locale_t loc);
-size_t wcsnrtombs_l( char *__restrict dst, const wchar_t **__restrict src,
-                     size_t nwc, size_t len, mbstate_t *__restrict ps, locale_t loc);
-wint_t btowc_l( int c, locale_t loc );
-int wctob_l( wint_t c, locale_t loc );
-
-decltype(MB_CUR_MAX) MB_CUR_MAX_L( locale_t __l );
-
-// the *_l functions are prefixed on Windows, only available for msvcr80+, VS2005+
-#define mbtowc_l _mbtowc_l
-#define strtoll_l _strtoi64_l
-#define strtoull_l _strtoui64_l
-#define strtod_l _strtod_l
-#if defined(_LIBCPP_MSVCRT)
-#define strtof_l _strtof_l
-#define strtold_l _strtold_l
-#else
-float strtof_l(const char*, char**, locale_t);
-long double strtold_l(const char*, char**, locale_t);
-#endif
-inline _LIBCPP_INLINE_VISIBILITY
-int
-islower_l(int c, _locale_t loc)
-{
- return _islower_l((int)c, loc);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-int
-isupper_l(int c, _locale_t loc)
-{
- return _isupper_l((int)c, loc);
-}
-
-#define isdigit_l _isdigit_l
-#define isxdigit_l _isxdigit_l
-#define strcoll_l _strcoll_l
-#define strxfrm_l _strxfrm_l
-#define wcscoll_l _wcscoll_l
-#define wcsxfrm_l _wcsxfrm_l
-#define toupper_l _toupper_l
-#define tolower_l _tolower_l
-#define iswspace_l _iswspace_l
-#define iswprint_l _iswprint_l
-#define iswcntrl_l _iswcntrl_l
-#define iswupper_l _iswupper_l
-#define iswlower_l _iswlower_l
-#define iswalpha_l _iswalpha_l
-#define iswdigit_l _iswdigit_l
-#define iswpunct_l _iswpunct_l
-#define iswxdigit_l _iswxdigit_l
-#define towupper_l _towupper_l
-#define towlower_l _towlower_l
-#if defined(__MINGW32__) && __MSVCRT_VERSION__ < 0x0800
-#define strftime_l( __s, __l, __f, __tm, __loc ) strftime( __s, __l, __f, __tm )
-#else
-#define strftime_l _strftime_l
-#endif
-#define sscanf_l( __s, __l, __f, ...) _sscanf_l( __s, __f, __l, __VA_ARGS__ )
-#define sprintf_l( __s, __l, __f, ... ) _sprintf_l( __s, __f, __l, __VA_ARGS__ )
-#define vsprintf_l( __s, __l, __f, ... ) _vsprintf_l( __s, __f, __l, __VA_ARGS__ )
-#define vsnprintf_l( __s, __n, __l, __f, ... ) _vsnprintf_l( __s, __n, __f, __l, __VA_ARGS__ )
-_LIBCPP_FUNC_VIS int snprintf_l(char *ret, size_t n, locale_t loc, const char *format, ...);
-_LIBCPP_FUNC_VIS int asprintf_l( char **ret, locale_t loc, const char *format, ... );
-_LIBCPP_FUNC_VIS int vasprintf_l( char **ret, locale_t loc, const char *format, va_list ap );
-
-// not-so-pressing FIXME: use locale to determine blank characters
-inline int isblank_l( int c, locale_t /*loc*/ )
-{
-    return ( c == ' ' || c == '\t' );
-}
-inline int iswblank_l( wint_t c, locale_t /*loc*/ )
-{
-    return ( c == L' ' || c == L'\t' );
-}
-
-#endif // _LIBCPP_SUPPORT_WIN32_LOCALE_WIN32_H
diff --git a/lib/libcxx/include/support/xlocale/__nop_locale_mgmt.h b/lib/libcxx/include/support/xlocale/__nop_locale_mgmt.h
deleted file mode 100644
index 0d3f23a2c96..00000000000
--- a/lib/libcxx/include/support/xlocale/__nop_locale_mgmt.h
+++ /dev/null
@@ -1,52 +0,0 @@
-// -*- C++ -*-
-//===------------  support/xlocale/__nop_locale_mgmt.h -----------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_XLOCALE_NOP_LOCALE_MGMT_H
-#define _LIBCPP_SUPPORT_XLOCALE_NOP_LOCALE_MGMT_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-// Patch over lack of extended locale support
-typedef void *locale_t;
-static inline locale_t duplocale(locale_t) {
-  return NULL;
-}
-
-static inline void freelocale(locale_t) {
-}
-
-static inline locale_t newlocale(int, const char *, locale_t) {
-  return NULL;
-}
-
-static inline locale_t uselocale(locale_t) {
-  return NULL;
-}
-
-#define LC_COLLATE_MASK  (1 << LC_COLLATE)
-#define LC_CTYPE_MASK    (1 << LC_CTYPE)
-#define LC_MESSAGES_MASK (1 << LC_MESSAGES)
-#define LC_MONETARY_MASK (1 << LC_MONETARY)
-#define LC_NUMERIC_MASK  (1 << LC_NUMERIC)
-#define LC_TIME_MASK     (1 << LC_TIME)
-#define LC_ALL_MASK (LC_COLLATE_MASK|\
-                     LC_CTYPE_MASK|\
-                     LC_MONETARY_MASK|\
-                     LC_NUMERIC_MASK|\
-                     LC_TIME_MASK|\
-                     LC_MESSAGES_MASK)
-
-#ifdef __cplusplus
-} // extern "C"
-#endif
-
-#endif // _LIBCPP_SUPPORT_XLOCALE_NOP_LOCALE_MGMT_H
diff --git a/lib/libcxx/include/support/xlocale/__posix_l_fallback.h b/lib/libcxx/include/support/xlocale/__posix_l_fallback.h
deleted file mode 100644
index b9a0939f8fa..00000000000
--- a/lib/libcxx/include/support/xlocale/__posix_l_fallback.h
+++ /dev/null
@@ -1,165 +0,0 @@
-// -*- C++ -*-
-//===--------------- support/xlocale/__posix_l_fallback.h -----------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-// These are reimplementations of some extended locale functions ( *_l ) that
-// are normally part of POSIX.  This shared implementation provides parts of the
-// extended locale support for libc's that normally don't have any (like
-// Android's bionic and Newlib).
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_XLOCALE_POSIX_L_FALLBACK_H
-#define _LIBCPP_SUPPORT_XLOCALE_POSIX_L_FALLBACK_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-inline _LIBCPP_INLINE_VISIBILITY int isalnum_l(int c, locale_t) {
-  return ::isalnum(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int isalpha_l(int c, locale_t) {
-  return ::isalpha(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int isblank_l(int c, locale_t) {
-  return ::isblank(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iscntrl_l(int c, locale_t) {
-  return ::iscntrl(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int isdigit_l(int c, locale_t) {
-  return ::isdigit(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int isgraph_l(int c, locale_t) {
-  return ::isgraph(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int islower_l(int c, locale_t) {
-  return ::islower(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int isprint_l(int c, locale_t) {
-  return ::isprint(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int ispunct_l(int c, locale_t) {
-  return ::ispunct(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int isspace_l(int c, locale_t) {
-  return ::isspace(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int isupper_l(int c, locale_t) {
-  return ::isupper(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int isxdigit_l(int c, locale_t) {
-  return ::isxdigit(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswalnum_l(wint_t c, locale_t) {
-  return ::iswalnum(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswalpha_l(wint_t c, locale_t) {
-  return ::iswalpha(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswblank_l(wint_t c, locale_t) {
-  return ::iswblank(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswcntrl_l(wint_t c, locale_t) {
-  return ::iswcntrl(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswdigit_l(wint_t c, locale_t) {
-  return ::iswdigit(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswgraph_l(wint_t c, locale_t) {
-  return ::iswgraph(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswlower_l(wint_t c, locale_t) {
-  return ::iswlower(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswprint_l(wint_t c, locale_t) {
-  return ::iswprint(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswpunct_l(wint_t c, locale_t) {
-  return ::iswpunct(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswspace_l(wint_t c, locale_t) {
-  return ::iswspace(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswupper_l(wint_t c, locale_t) {
-  return ::iswupper(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int iswxdigit_l(wint_t c, locale_t) {
-  return ::iswxdigit(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int toupper_l(int c, locale_t) {
-  return ::toupper(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int tolower_l(int c, locale_t) {
-  return ::tolower(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY wint_t towupper_l(wint_t c, locale_t) {
-  return ::towupper(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY wint_t towlower_l(wint_t c, locale_t) {
-  return ::towlower(c);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int strcoll_l(const char *s1, const char *s2,
-                                               locale_t) {
-  return ::strcoll(s1, s2);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY size_t strxfrm_l(char *dest, const char *src,
-                                                  size_t n, locale_t) {
-  return ::strxfrm(dest, src, n);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY size_t strftime_l(char *s, size_t max,
-                                                   const char *format,
-                                                   const struct tm *tm, locale_t) {
-  return ::strftime(s, max, format, tm);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY int wcscoll_l(const wchar_t *ws1,
-                                               const wchar_t *ws2, locale_t) {
-  return ::wcscoll(ws1, ws2);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY size_t wcsxfrm_l(wchar_t *dest, const wchar_t *src,
-                                                  size_t n, locale_t) {
-  return ::wcsxfrm(dest, src, n);
-}
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif // _LIBCPP_SUPPORT_XLOCALE_POSIX_L_FALLBACK_H
diff --git a/lib/libcxx/include/support/xlocale/__strtonum_fallback.h b/lib/libcxx/include/support/xlocale/__strtonum_fallback.h
deleted file mode 100644
index 50b4db35427..00000000000
--- a/lib/libcxx/include/support/xlocale/__strtonum_fallback.h
+++ /dev/null
@@ -1,67 +0,0 @@
-// -*- C++ -*-
-//===-------------- support/xlocale/__strtonum_fallback.h -----------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-// These are reimplementations of some extended locale functions ( *_l ) that
-// aren't part of POSIX.  They are widely available though (GLIBC, BSD, maybe
-// others).  The unifying aspect in this case is that all of these functions
-// convert strings to some numeric type.
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SUPPORT_XLOCALE_STRTONUM_FALLBACK_H
-#define _LIBCPP_SUPPORT_XLOCALE_STRTONUM_FALLBACK_H
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-inline _LIBCPP_INLINE_VISIBILITY float strtof_l(const char *nptr,
-                                                char **endptr, locale_t) {
-  return ::strtof(nptr, endptr);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY double strtod_l(const char *nptr,
-                                                 char **endptr, locale_t) {
-  return ::strtod(nptr, endptr);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY long double strtold_l(const char *nptr,
-                                                       char **endptr, locale_t) {
-  return ::strtold(nptr, endptr);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY long long
-strtoll_l(const char *nptr, char **endptr, int base, locale_t) {
-  return ::strtoll(nptr, endptr, base);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY unsigned long long
-strtoull_l(const char *nptr, char **endptr, int base, locale_t) {
-  return ::strtoull(nptr, endptr, base);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY long long
-wcstoll_l(const wchar_t *nptr, wchar_t **endptr, int base, locale_t) {
-  return ::wcstoll(nptr, endptr, base);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY unsigned long long
-wcstoull_l(const wchar_t *nptr, wchar_t **endptr, int base, locale_t) {
-  return ::wcstoull(nptr, endptr, base);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY long double wcstold_l(const wchar_t *nptr,
-                                                       wchar_t **endptr, locale_t) {
-  return ::wcstold(nptr, endptr);
-}
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif // _LIBCPP_SUPPORT_XLOCALE_STRTONUM_FALLBACK_H
diff --git a/lib/libcxx/include/support/xlocale/xlocale.h b/lib/libcxx/include/support/xlocale/xlocale.h
deleted file mode 100644
index e69de29bb2d..00000000000
--- a/lib/libcxx/include/support/xlocale/xlocale.h
+++ /dev/null
diff --git a/lib/libcxx/include/system_error b/lib/libcxx/include/system_error
deleted file mode 100644
index 6e2c8388f17..00000000000
--- a/lib/libcxx/include/system_error
+++ /dev/null
@@ -1,487 +0,0 @@
-// -*- C++ -*-
-//===---------------------------- system_error ----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_SYSTEM_ERROR
-#define _LIBCPP_SYSTEM_ERROR
-
-/*
-    system_error synopsis
-
-namespace std
-{
-
-class error_category
-{
-public:
-    virtual ~error_category() noexcept;
-
-    constexpr error_category();
-    error_category(const error_category&) = delete;
-    error_category& operator=(const error_category&) = delete;
-
-    virtual const char* name() const noexcept = 0;
-    virtual error_condition default_error_condition(int ev) const noexcept;
-    virtual bool equivalent(int code, const error_condition& condition) const noexcept;
-    virtual bool equivalent(const error_code& code, int condition) const noexcept;
-    virtual string message(int ev) const = 0;
-
-    bool operator==(const error_category& rhs) const noexcept;
-    bool operator!=(const error_category& rhs) const noexcept;
-    bool operator<(const error_category& rhs) const noexcept;
-};
-
-const error_category& generic_category() noexcept;
-const error_category& system_category() noexcept;
-
-template <class T> struct is_error_code_enum
-    : public false_type {};
-
-template <class T> struct is_error_condition_enum
-    : public false_type {};
-
-template <class _Tp>
-inline constexpr size_t is_error_condition_enum_v = is_error_condition_enum<_Tp>::value; // C++17
-
-template <class _Tp>
-inline constexpr size_t is_error_code_enum_v = is_error_code_enum<_Tp>::value; // C++17
-
-class error_code
-{
-public:
-    // constructors:
-    error_code() noexcept;
-    error_code(int val, const error_category& cat) noexcept;
-    template <class ErrorCodeEnum>
-        error_code(ErrorCodeEnum e) noexcept;
-
-    // modifiers:
-    void assign(int val, const error_category& cat) noexcept;
-    template <class ErrorCodeEnum>
-        error_code& operator=(ErrorCodeEnum e) noexcept;
-    void clear() noexcept;
-
-    // observers:
-    int value() const noexcept;
-    const error_category& category() const noexcept;
-    error_condition default_error_condition() const noexcept;
-    string message() const;
-    explicit operator bool() const noexcept;
-};
-
-// non-member functions:
-bool operator<(const error_code& lhs, const error_code& rhs) noexcept;
-template <class charT, class traits>
-    basic_ostream<charT,traits>&
-    operator<<(basic_ostream<charT,traits>& os, const error_code& ec);
-
-class error_condition
-{
-public:
-    // constructors:
-    error_condition() noexcept;
-    error_condition(int val, const error_category& cat) noexcept;
-    template <class ErrorConditionEnum>
-        error_condition(ErrorConditionEnum e) noexcept;
-
-    // modifiers:
-    void assign(int val, const error_category& cat) noexcept;
-    template <class ErrorConditionEnum>
-        error_condition& operator=(ErrorConditionEnum e) noexcept;
-    void clear() noexcept;
-
-    // observers:
-    int value() const noexcept;
-    const error_category& category() const noexcept;
-    string message() const noexcept;
-    explicit operator bool() const noexcept;
-};
-
-bool operator<(const error_condition& lhs, const error_condition& rhs) noexcept;
-
-class system_error
-    : public runtime_error
-{
-public:
-    system_error(error_code ec, const string& what_arg);
-    system_error(error_code ec, const char* what_arg);
-    system_error(error_code ec);
-    system_error(int ev, const error_category& ecat, const string& what_arg);
-    system_error(int ev, const error_category& ecat, const char* what_arg);
-    system_error(int ev, const error_category& ecat);
-
-    const error_code& code() const noexcept;
-    const char* what() const noexcept;
-};
-
-template <> struct is_error_condition_enum<errc>
-    : true_type { }
-
-error_code make_error_code(errc e) noexcept;
-error_condition make_error_condition(errc e) noexcept;
-
-// Comparison operators:
-bool operator==(const error_code& lhs, const error_code& rhs) noexcept;
-bool operator==(const error_code& lhs, const error_condition& rhs) noexcept;
-bool operator==(const error_condition& lhs, const error_code& rhs) noexcept;
-bool operator==(const error_condition& lhs, const error_condition& rhs) noexcept;
-bool operator!=(const error_code& lhs, const error_code& rhs) noexcept;
-bool operator!=(const error_code& lhs, const error_condition& rhs) noexcept;
-bool operator!=(const error_condition& lhs, const error_code& rhs) noexcept;
-bool operator!=(const error_condition& lhs, const error_condition& rhs) noexcept;
-
-template <> struct hash<std::error_code>;
-template <> struct hash<std::error_condition>;
-
-}  // std
-
-*/
-
-#include <__errc>
-#include <type_traits>
-#include <stdexcept>
-#include <__functional_base>
-#include <string>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-// is_error_code_enum
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_error_code_enum
-    : public false_type {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr size_t is_error_code_enum_v = is_error_code_enum<_Tp>::value;
-#endif
-
-// is_error_condition_enum
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_error_condition_enum
-    : public false_type {};
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr size_t is_error_condition_enum_v = is_error_condition_enum<_Tp>::value;
-#endif
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS is_error_condition_enum<errc>
-    : true_type { };
-
-#ifdef _LIBCPP_HAS_NO_STRONG_ENUMS
-template <>
-struct _LIBCPP_TEMPLATE_VIS is_error_condition_enum<errc::__lx>
-    : true_type { };
-#endif
-
-class _LIBCPP_TYPE_VIS error_condition;
-class _LIBCPP_TYPE_VIS error_code;
-
-// class error_category
-
-class _LIBCPP_HIDDEN __do_message;
-
-class _LIBCPP_TYPE_VIS error_category
-{
-public:
-    virtual ~error_category() _NOEXCEPT;
-
-#if defined(_LIBCPP_BUILDING_LIBRARY) && \
-    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
-    error_category() _NOEXCEPT;
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR_AFTER_CXX11 error_category() _NOEXCEPT _LIBCPP_DEFAULT
-#endif
-private:
-    error_category(const error_category&);// = delete;
-    error_category& operator=(const error_category&);// = delete;
-
-public:
-    virtual const char* name() const _NOEXCEPT = 0;
-    virtual error_condition default_error_condition(int __ev) const _NOEXCEPT;
-    virtual bool equivalent(int __code, const error_condition& __condition) const _NOEXCEPT;
-    virtual bool equivalent(const error_code& __code, int __condition) const _NOEXCEPT;
-    virtual string message(int __ev) const = 0;
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const error_category& __rhs) const _NOEXCEPT {return this == &__rhs;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const error_category& __rhs) const _NOEXCEPT {return !(*this == __rhs);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator< (const error_category& __rhs) const _NOEXCEPT {return this < &__rhs;}
-
-    friend class _LIBCPP_HIDDEN __do_message;
-};
-
-class _LIBCPP_HIDDEN __do_message
-    : public error_category
-{
-public:
-    virtual string message(int ev) const;
-};
-
-_LIBCPP_FUNC_VIS const error_category& generic_category() _NOEXCEPT;
-_LIBCPP_FUNC_VIS const error_category& system_category() _NOEXCEPT;
-
-class _LIBCPP_TYPE_VIS error_condition
-{
-    int __val_;
-    const error_category* __cat_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    error_condition() _NOEXCEPT : __val_(0), __cat_(&generic_category()) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    error_condition(int __val, const error_category& __cat) _NOEXCEPT
-        : __val_(__val), __cat_(&__cat) {}
-
-    template <class _Ep>
-        _LIBCPP_INLINE_VISIBILITY
-        error_condition(_Ep __e,
-              typename enable_if<is_error_condition_enum<_Ep>::value>::type* = 0
-                                                                     ) _NOEXCEPT
-            {*this = make_error_condition(__e);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void assign(int __val, const error_category& __cat) _NOEXCEPT
-    {
-        __val_ = __val;
-        __cat_ = &__cat;
-    }
-
-    template <class _Ep>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            is_error_condition_enum<_Ep>::value,
-            error_condition&
-        >::type
-        operator=(_Ep __e) _NOEXCEPT
-            {*this = make_error_condition(__e); return *this;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT
-    {
-        __val_ = 0;
-        __cat_ = &generic_category();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int value() const _NOEXCEPT {return __val_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const error_category& category() const _NOEXCEPT {return *__cat_;}
-    string message() const;
-
-    _LIBCPP_INLINE_VISIBILITY
-        _LIBCPP_EXPLICIT
-        operator bool() const _NOEXCEPT {return __val_ != 0;}
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-error_condition
-make_error_condition(errc __e) _NOEXCEPT
-{
-    return error_condition(static_cast<int>(__e), generic_category());
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const error_condition& __x, const error_condition& __y) _NOEXCEPT
-{
-    return __x.category() < __y.category()
-        || (__x.category() == __y.category() && __x.value() < __y.value());
-}
-
-// error_code
-
-class _LIBCPP_TYPE_VIS error_code
-{
-    int __val_;
-    const error_category* __cat_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    error_code() _NOEXCEPT : __val_(0), __cat_(&system_category()) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    error_code(int __val, const error_category& __cat) _NOEXCEPT
-        : __val_(__val), __cat_(&__cat) {}
-
-    template <class _Ep>
-        _LIBCPP_INLINE_VISIBILITY
-        error_code(_Ep __e,
-                   typename enable_if<is_error_code_enum<_Ep>::value>::type* = 0
-                                                                     ) _NOEXCEPT
-            {*this = make_error_code(__e);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void assign(int __val, const error_category& __cat) _NOEXCEPT
-    {
-        __val_ = __val;
-        __cat_ = &__cat;
-    }
-
-    template <class _Ep>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            is_error_code_enum<_Ep>::value,
-            error_code&
-        >::type
-        operator=(_Ep __e) _NOEXCEPT
-            {*this = make_error_code(__e); return *this;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT
-    {
-        __val_ = 0;
-        __cat_ = &system_category();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int value() const _NOEXCEPT {return __val_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const error_category& category() const _NOEXCEPT {return *__cat_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    error_condition default_error_condition() const _NOEXCEPT
-        {return __cat_->default_error_condition(__val_);}
-
-    string message() const;
-
-    _LIBCPP_INLINE_VISIBILITY
-        _LIBCPP_EXPLICIT
-        operator bool() const _NOEXCEPT {return __val_ != 0;}
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-error_code
-make_error_code(errc __e) _NOEXCEPT
-{
-    return error_code(static_cast<int>(__e), generic_category());
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<(const error_code& __x, const error_code& __y) _NOEXCEPT
-{
-    return __x.category() < __y.category()
-        || (__x.category() == __y.category() && __x.value() < __y.value());
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const error_code& __x, const error_code& __y) _NOEXCEPT
-{
-    return __x.category() == __y.category() && __x.value() == __y.value();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const error_code& __x, const error_condition& __y) _NOEXCEPT
-{
-    return __x.category().equivalent(__x.value(), __y)
-        || __y.category().equivalent(__x, __y.value());
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const error_condition& __x, const error_code& __y) _NOEXCEPT
-{
-    return __y == __x;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const error_condition& __x, const error_condition& __y) _NOEXCEPT
-{
-    return __x.category() == __y.category() && __x.value() == __y.value();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const error_code& __x, const error_code& __y) _NOEXCEPT
-{return !(__x == __y);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const error_code& __x, const error_condition& __y) _NOEXCEPT
-{return !(__x == __y);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const error_condition& __x, const error_code& __y) _NOEXCEPT
-{return !(__x == __y);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const error_condition& __x, const error_condition& __y) _NOEXCEPT
-{return !(__x == __y);}
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<error_code>
-    : public unary_function<error_code, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const error_code& __ec) const _NOEXCEPT
-    {
-        return static_cast<size_t>(__ec.value());
-    }
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<error_condition>
-    : public unary_function<error_condition, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const error_condition& __ec) const _NOEXCEPT
-    {
-        return static_cast<size_t>(__ec.value());
-    }
-};
-
-// system_error
-
-class _LIBCPP_TYPE_VIS system_error
-    : public runtime_error
-{
-    error_code __ec_;
-public:
-    system_error(error_code __ec, const string& __what_arg);
-    system_error(error_code __ec, const char* __what_arg);
-    system_error(error_code __ec);
-    system_error(int __ev, const error_category& __ecat, const string& __what_arg);
-    system_error(int __ev, const error_category& __ecat, const char* __what_arg);
-    system_error(int __ev, const error_category& __ecat);
-    ~system_error() _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    const error_code& code() const _NOEXCEPT {return __ec_;}
-
-private:
-    static string __init(const error_code&, string);
-};
-
-_LIBCPP_NORETURN _LIBCPP_FUNC_VIS
-void __throw_system_error(int ev, const char* what_arg);
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_SYSTEM_ERROR
diff --git a/lib/libcxx/include/tgmath.h b/lib/libcxx/include/tgmath.h
deleted file mode 100644
index aba87499c29..00000000000
--- a/lib/libcxx/include/tgmath.h
+++ /dev/null
@@ -1,37 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- tgmath.h ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_TGMATH_H
-#define _LIBCPP_TGMATH_H
-
-/*
-    tgmath.h synopsis
-
-#include <ctgmath>
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef __cplusplus
-
-#include <ctgmath>
-
-#else  // __cplusplus
-
-#include_next <tgmath.h>
-
-#endif  // __cplusplus
-
-#endif  // _LIBCPP_TGMATH_H
diff --git a/lib/libcxx/include/thread b/lib/libcxx/include/thread
deleted file mode 100644
index 8c0115f8708..00000000000
--- a/lib/libcxx/include/thread
+++ /dev/null
@@ -1,484 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- thread -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_THREAD
-#define _LIBCPP_THREAD
-
-/*
-
-    thread synopsis
-
-#define __STDCPP_THREADS__ __cplusplus
-
-namespace std
-{
-
-class thread
-{
-public:
-    class id;
-    typedef pthread_t native_handle_type;
-
-    thread() noexcept;
-    template <class F, class ...Args> explicit thread(F&& f, Args&&... args);
-    ~thread();
-
-    thread(const thread&) = delete;
-    thread(thread&& t) noexcept;
-
-    thread& operator=(const thread&) = delete;
-    thread& operator=(thread&& t) noexcept;
-
-    void swap(thread& t) noexcept;
-
-    bool joinable() const noexcept;
-    void join();
-    void detach();
-    id get_id() const noexcept;
-    native_handle_type native_handle();
-
-    static unsigned hardware_concurrency() noexcept;
-};
-
-void swap(thread& x, thread& y) noexcept;
-
-class thread::id
-{
-public:
-    id() noexcept;
-};
-
-bool operator==(thread::id x, thread::id y) noexcept;
-bool operator!=(thread::id x, thread::id y) noexcept;
-bool operator< (thread::id x, thread::id y) noexcept;
-bool operator<=(thread::id x, thread::id y) noexcept;
-bool operator> (thread::id x, thread::id y) noexcept;
-bool operator>=(thread::id x, thread::id y) noexcept;
-
-template<class charT, class traits>
-basic_ostream<charT, traits>&
-operator<<(basic_ostream<charT, traits>& out, thread::id id);
-
-namespace this_thread
-{
-
-thread::id get_id() noexcept;
-
-void yield() noexcept;
-
-template <class Clock, class Duration>
-void sleep_until(const chrono::time_point<Clock, Duration>& abs_time);
-
-template <class Rep, class Period>
-void sleep_for(const chrono::duration<Rep, Period>& rel_time);
-
-}  // this_thread
-
-}  // std
-
-*/
-
-#include <__config>
-#include <iosfwd>
-#include <__functional_base>
-#include <type_traits>
-#include <cstddef>
-#include <functional>
-#include <memory>
-#include <system_error>
-#include <chrono>
-#include <__mutex_base>
-#ifndef _LIBCPP_CXX03_LANG
-#include <tuple>
-#endif
-#include <__threading_support>
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-#define __STDCPP_THREADS__ __cplusplus
-
-#ifdef _LIBCPP_HAS_NO_THREADS
-#error <thread> is not supported on this single threaded system
-#else // !_LIBCPP_HAS_NO_THREADS
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Tp> class __thread_specific_ptr;
-class _LIBCPP_TYPE_VIS __thread_struct;
-class _LIBCPP_HIDDEN __thread_struct_imp;
-class __assoc_sub_state;
-
-_LIBCPP_FUNC_VIS __thread_specific_ptr<__thread_struct>& __thread_local_data();
-
-class _LIBCPP_TYPE_VIS __thread_struct
-{
-    __thread_struct_imp* __p_;
-
-    __thread_struct(const __thread_struct&);
-    __thread_struct& operator=(const __thread_struct&);
-public:
-    __thread_struct();
-    ~__thread_struct();
-
-    void notify_all_at_thread_exit(condition_variable*, mutex*);
-    void __make_ready_at_thread_exit(__assoc_sub_state*);
-};
-
-template <class _Tp>
-class __thread_specific_ptr
-{
-    __libcpp_tls_key __key_;
-
-     // Only __thread_local_data() may construct a __thread_specific_ptr
-     // and only with _Tp == __thread_struct.
-    static_assert((is_same<_Tp, __thread_struct>::value), "");
-    __thread_specific_ptr();
-    friend _LIBCPP_FUNC_VIS __thread_specific_ptr<__thread_struct>& __thread_local_data();
-
-    __thread_specific_ptr(const __thread_specific_ptr&);
-    __thread_specific_ptr& operator=(const __thread_specific_ptr&);
-
-    _LIBCPP_HIDDEN static void _LIBCPP_TLS_DESTRUCTOR_CC __at_thread_exit(void*);
-
-public:
-    typedef _Tp* pointer;
-
-    ~__thread_specific_ptr();
-
-    _LIBCPP_INLINE_VISIBILITY
-    pointer get() const {return static_cast<_Tp*>(__libcpp_tls_get(__key_));}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator*() const {return *get();}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {return get();}
-    void set_pointer(pointer __p);
-};
-
-template <class _Tp>
-void _LIBCPP_TLS_DESTRUCTOR_CC
-__thread_specific_ptr<_Tp>::__at_thread_exit(void* __p)
-{
-    delete static_cast<pointer>(__p);
-}
-
-template <class _Tp>
-__thread_specific_ptr<_Tp>::__thread_specific_ptr()
-{
-  int __ec =
-      __libcpp_tls_create(&__key_, &__thread_specific_ptr::__at_thread_exit);
-  if (__ec)
-    __throw_system_error(__ec, "__thread_specific_ptr construction failed");
-}
-
-template <class _Tp>
-__thread_specific_ptr<_Tp>::~__thread_specific_ptr()
-{
-    // __thread_specific_ptr is only created with a static storage duration
-    // so this destructor is only invoked during program termination. Invoking
-    // pthread_key_delete(__key_) may prevent other threads from deleting their
-    // thread local data. For this reason we leak the key.
-}
-
-template <class _Tp>
-void
-__thread_specific_ptr<_Tp>::set_pointer(pointer __p)
-{
-    _LIBCPP_ASSERT(get() == nullptr,
-                   "Attempting to overwrite thread local data");
-    __libcpp_tls_set(__key_, __p);
-}
-
-class _LIBCPP_TYPE_VIS thread;
-class _LIBCPP_TYPE_VIS __thread_id;
-
-namespace this_thread
-{
-
-_LIBCPP_INLINE_VISIBILITY __thread_id get_id() _NOEXCEPT;
-
-}  // this_thread
-
-template<> struct hash<__thread_id>;
-
-class _LIBCPP_TEMPLATE_VIS __thread_id
-{
-    // FIXME: pthread_t is a pointer on Darwin but a long on Linux.
-    // NULL is the no-thread value on Darwin.  Someone needs to check
-    // on other platforms.  We assume 0 works everywhere for now.
-    __libcpp_thread_id __id_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __thread_id() _NOEXCEPT : __id_(0) {}
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(__thread_id __x, __thread_id __y) _NOEXCEPT
-        {return __libcpp_thread_id_equal(__x.__id_, __y.__id_);}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(__thread_id __x, __thread_id __y) _NOEXCEPT
-        {return !(__x == __y);}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator< (__thread_id __x, __thread_id __y) _NOEXCEPT
-        {return  __libcpp_thread_id_less(__x.__id_, __y.__id_);}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator<=(__thread_id __x, __thread_id __y) _NOEXCEPT
-        {return !(__y < __x);}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator> (__thread_id __x, __thread_id __y) _NOEXCEPT
-        {return   __y < __x ;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator>=(__thread_id __x, __thread_id __y) _NOEXCEPT
-        {return !(__x < __y);}
-
-    template<class _CharT, class _Traits>
-    friend
-    _LIBCPP_INLINE_VISIBILITY
-    basic_ostream<_CharT, _Traits>&
-    operator<<(basic_ostream<_CharT, _Traits>& __os, __thread_id __id)
-        {return __os << __id.__id_;}
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    __thread_id(__libcpp_thread_id __id) : __id_(__id) {}
-
-    friend __thread_id this_thread::get_id() _NOEXCEPT;
-    friend class _LIBCPP_TYPE_VIS thread;
-    friend struct _LIBCPP_TEMPLATE_VIS hash<__thread_id>;
-};
-
-template<>
-struct _LIBCPP_TEMPLATE_VIS hash<__thread_id>
-    : public unary_function<__thread_id, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(__thread_id __v) const _NOEXCEPT
-    {
-        return hash<__libcpp_thread_id>()(__v.__id_);
-    }
-};
-
-namespace this_thread
-{
-
-inline _LIBCPP_INLINE_VISIBILITY
-__thread_id
-get_id() _NOEXCEPT
-{
-    return __libcpp_thread_get_current_id();
-}
-
-}  // this_thread
-
-class _LIBCPP_TYPE_VIS thread
-{
-    __libcpp_thread_t __t_;
-
-    thread(const thread&);
-    thread& operator=(const thread&);
-public:
-    typedef __thread_id id;
-    typedef __libcpp_thread_t native_handle_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    thread() _NOEXCEPT : __t_(_LIBCPP_NULL_THREAD) {}
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Fp, class ..._Args,
-              class = typename enable_if
-              <
-                   !is_same<typename __uncvref<_Fp>::type, thread>::value
-              >::type
-             >
-        _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-        explicit thread(_Fp&& __f, _Args&&... __args);
-#else  // _LIBCPP_CXX03_LANG
-    template <class _Fp>
-    _LIBCPP_METHOD_TEMPLATE_IMPLICIT_INSTANTIATION_VIS
-    explicit thread(_Fp __f);
-#endif
-    ~thread();
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    thread(thread&& __t) _NOEXCEPT : __t_(__t.__t_) {__t.__t_ = _LIBCPP_NULL_THREAD;}
-    _LIBCPP_INLINE_VISIBILITY
-    thread& operator=(thread&& __t) _NOEXCEPT;
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(thread& __t) _NOEXCEPT {_VSTD::swap(__t_, __t.__t_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool joinable() const _NOEXCEPT {return !__libcpp_thread_isnull(&__t_);}
-    void join();
-    void detach();
-    _LIBCPP_INLINE_VISIBILITY
-    id get_id() const _NOEXCEPT {return __libcpp_thread_get_id(&__t_);}
-    _LIBCPP_INLINE_VISIBILITY
-    native_handle_type native_handle() _NOEXCEPT {return __t_;}
-
-    static unsigned hardware_concurrency() _NOEXCEPT;
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _TSp, class _Fp, class ..._Args, size_t ..._Indices>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__thread_execute(tuple<_TSp, _Fp, _Args...>& __t, __tuple_indices<_Indices...>)
-{
-    __invoke(_VSTD::move(_VSTD::get<1>(__t)), _VSTD::move(_VSTD::get<_Indices>(__t))...);
-}
-
-template <class _Fp>
-void* __thread_proxy(void* __vp)
-{
-    // _Fp = std::tuple< unique_ptr<__thread_struct>, Functor, Args...>
-    std::unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));
-    __thread_local_data().set_pointer(_VSTD::get<0>(*__p).release());
-    typedef typename __make_tuple_indices<tuple_size<_Fp>::value, 2>::type _Index;
-    __thread_execute(*__p, _Index());
-    return nullptr;
-}
-
-template <class _Fp, class ..._Args,
-          class
-         >
-thread::thread(_Fp&& __f, _Args&&... __args)
-{
-    typedef unique_ptr<__thread_struct> _TSPtr;
-    _TSPtr __tsp(new __thread_struct);
-    typedef tuple<_TSPtr, typename decay<_Fp>::type, typename decay<_Args>::type...> _Gp;
-    _VSTD::unique_ptr<_Gp> __p(
-            new _Gp(std::move(__tsp),
-                    __decay_copy(_VSTD::forward<_Fp>(__f)),
-                    __decay_copy(_VSTD::forward<_Args>(__args))...));
-    int __ec = __libcpp_thread_create(&__t_, &__thread_proxy<_Gp>, __p.get());
-    if (__ec == 0)
-        __p.release();
-    else
-        __throw_system_error(__ec, "thread constructor failed");
-}
-
-inline
-thread&
-thread::operator=(thread&& __t) _NOEXCEPT
-{
-    if (!__libcpp_thread_isnull(&__t_))
-        terminate();
-    __t_ = __t.__t_;
-    __t.__t_ = _LIBCPP_NULL_THREAD;
-    return *this;
-}
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _Fp>
-struct __thread_invoke_pair {
-    // This type is used to pass memory for thread local storage and a functor
-    // to a newly created thread because std::pair doesn't work with
-    // std::unique_ptr in C++03.
-    __thread_invoke_pair(_Fp& __f) : __tsp_(new __thread_struct), __fn_(__f) {}
-    unique_ptr<__thread_struct> __tsp_;
-    _Fp __fn_;
-};
-
-template <class _Fp>
-void* __thread_proxy_cxx03(void* __vp)
-{
-    std::unique_ptr<_Fp> __p(static_cast<_Fp*>(__vp));
-    __thread_local_data().set_pointer(__p->__tsp_.release());
-    (__p->__fn_)();
-    return nullptr;
-}
-
-template <class _Fp>
-thread::thread(_Fp __f)
-{
-
-    typedef __thread_invoke_pair<_Fp> _InvokePair;
-    typedef std::unique_ptr<_InvokePair> _PairPtr;
-    _PairPtr __pp(new _InvokePair(__f));
-    int __ec = __libcpp_thread_create(&__t_, &__thread_proxy_cxx03<_InvokePair>, __pp.get());
-    if (__ec == 0)
-        __pp.release();
-    else
-        __throw_system_error(__ec, "thread constructor failed");
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-inline _LIBCPP_INLINE_VISIBILITY
-void swap(thread& __x, thread& __y) _NOEXCEPT {__x.swap(__y);}
-
-namespace this_thread
-{
-
-_LIBCPP_FUNC_VIS void sleep_for(const chrono::nanoseconds& __ns);
-
-template <class _Rep, class _Period>
-void
-sleep_for(const chrono::duration<_Rep, _Period>& __d)
-{
-    using namespace chrono;
-    if (__d > duration<_Rep, _Period>::zero())
-    {
-        _LIBCPP_CONSTEXPR duration<long double> _Max = nanoseconds::max();
-        nanoseconds __ns;
-        if (__d < _Max)
-        {
-            __ns = duration_cast<nanoseconds>(__d);
-            if (__ns < __d)
-                ++__ns;
-        }
-        else
-            __ns = nanoseconds::max();
-        sleep_for(__ns);
-    }
-}
-
-template <class _Clock, class _Duration>
-void
-sleep_until(const chrono::time_point<_Clock, _Duration>& __t)
-{
-    using namespace chrono;
-    mutex __mut;
-    condition_variable __cv;
-    unique_lock<mutex> __lk(__mut);
-    while (_Clock::now() < __t)
-        __cv.wait_until(__lk, __t);
-}
-
-template <class _Duration>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-sleep_until(const chrono::time_point<chrono::steady_clock, _Duration>& __t)
-{
-    using namespace chrono;
-    sleep_for(__t - steady_clock::now());
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void yield() _NOEXCEPT {__libcpp_thread_yield();}
-
-}  // this_thread
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif // !_LIBCPP_HAS_NO_THREADS
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_THREAD
diff --git a/lib/libcxx/include/tuple b/lib/libcxx/include/tuple
deleted file mode 100644
index 4cc69030b9a..00000000000
--- a/lib/libcxx/include/tuple
+++ /dev/null
@@ -1,1395 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- tuple ------------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_TUPLE
-#define _LIBCPP_TUPLE
-
-/*
-    tuple synopsis
-
-namespace std
-{
-
-template <class... T>
-class tuple {
-public:
-    constexpr tuple();
-    explicit tuple(const T&...);  // constexpr in C++14
-    template <class... U>
-        explicit tuple(U&&...);  // constexpr in C++14
-    tuple(const tuple&) = default;
-    tuple(tuple&&) = default;
-    template <class... U>
-        tuple(const tuple<U...>&);  // constexpr in C++14
-    template <class... U>
-        tuple(tuple<U...>&&);  // constexpr in C++14
-    template <class U1, class U2>
-        tuple(const pair<U1, U2>&); // iff sizeof...(T) == 2 // constexpr in C++14
-    template <class U1, class U2>
-        tuple(pair<U1, U2>&&); // iff sizeof...(T) == 2  // constexpr in C++14
-
-    // allocator-extended constructors
-    template <class Alloc>
-        tuple(allocator_arg_t, const Alloc& a);
-    template <class Alloc>
-        tuple(allocator_arg_t, const Alloc& a, const T&...);
-    template <class Alloc, class... U>
-        tuple(allocator_arg_t, const Alloc& a, U&&...);
-    template <class Alloc>
-        tuple(allocator_arg_t, const Alloc& a, const tuple&);
-    template <class Alloc>
-        tuple(allocator_arg_t, const Alloc& a, tuple&&);
-    template <class Alloc, class... U>
-        tuple(allocator_arg_t, const Alloc& a, const tuple<U...>&);
-    template <class Alloc, class... U>
-        tuple(allocator_arg_t, const Alloc& a, tuple<U...>&&);
-    template <class Alloc, class U1, class U2>
-        tuple(allocator_arg_t, const Alloc& a, const pair<U1, U2>&);
-    template <class Alloc, class U1, class U2>
-        tuple(allocator_arg_t, const Alloc& a, pair<U1, U2>&&);
-
-    tuple& operator=(const tuple&);
-    tuple&
-        operator=(tuple&&) noexcept(AND(is_nothrow_move_assignable<T>::value ...));
-    template <class... U>
-        tuple& operator=(const tuple<U...>&);
-    template <class... U>
-        tuple& operator=(tuple<U...>&&);
-    template <class U1, class U2>
-        tuple& operator=(const pair<U1, U2>&); // iff sizeof...(T) == 2
-    template <class U1, class U2>
-        tuple& operator=(pair<U1, U2>&&); // iff sizeof...(T) == 2
-
-    void swap(tuple&) noexcept(AND(swap(declval<T&>(), declval<T&>())...));
-};
-
-inline constexpr unspecified ignore;
-
-template <class... T> tuple<V...>  make_tuple(T&&...); // constexpr in C++14
-template <class... T> tuple<ATypes...> forward_as_tuple(T&&...) noexcept; // constexpr in C++14
-template <class... T> tuple<T&...> tie(T&...) noexcept; // constexpr in C++14
-template <class... Tuples> tuple<CTypes...> tuple_cat(Tuples&&... tpls); // constexpr in C++14
-
-// [tuple.apply], calling a function with a tuple of arguments:
-template <class F, class Tuple>
-  constexpr decltype(auto) apply(F&& f, Tuple&& t); // C++17
-template <class T, class Tuple>
-  constexpr T make_from_tuple(Tuple&& t); // C++17
-
-// 20.4.1.4, tuple helper classes:
-template <class T> struct tuple_size; // undefined
-template <class... T> struct tuple_size<tuple<T...>>;
-template <class T>
- inline constexpr size_t tuple_size_v = tuple_size<T>::value; // C++17
-template <size_t I, class T> class tuple_element; // undefined
-template <size_t I, class... T> class tuple_element<I, tuple<T...>>;
-template <size_t I, class T>
-  using tuple_element_t = typename tuple_element <I, T>::type; // C++14
-
-// 20.4.1.5, element access:
-template <size_t I, class... T>
-    typename tuple_element<I, tuple<T...>>::type&
-    get(tuple<T...>&) noexcept; // constexpr in C++14
-template <size_t I, class... T>
-    const typename tuple_element<I, tuple<T...>>::type&
-    get(const tuple<T...>&) noexcept; // constexpr in C++14
-template <size_t I, class... T>
-    typename tuple_element<I, tuple<T...>>::type&&
-    get(tuple<T...>&&) noexcept; // constexpr in C++14
-template <size_t I, class... T>
-    const typename tuple_element<I, tuple<T...>>::type&&
-    get(const tuple<T...>&&) noexcept; // constexpr in C++14
-
-template <class T1, class... T>
-    constexpr T1& get(tuple<T...>&) noexcept;  // C++14
-template <class T1, class... T>
-    constexpr const T1& get(const tuple<T...>&) noexcept;   // C++14
-template <class T1, class... T>
-    constexpr T1&& get(tuple<T...>&&) noexcept;   // C++14
-template <class T1, class... T>
-    constexpr const T1&& get(const tuple<T...>&&) noexcept;   // C++14
-
-// 20.4.1.6, relational operators:
-template<class... T, class... U> bool operator==(const tuple<T...>&, const tuple<U...>&); // constexpr in C++14
-template<class... T, class... U> bool operator<(const tuple<T...>&, const tuple<U...>&);  // constexpr in C++14
-template<class... T, class... U> bool operator!=(const tuple<T...>&, const tuple<U...>&); // constexpr in C++14
-template<class... T, class... U> bool operator>(const tuple<T...>&, const tuple<U...>&);  // constexpr in C++14
-template<class... T, class... U> bool operator<=(const tuple<T...>&, const tuple<U...>&); // constexpr in C++14
-template<class... T, class... U> bool operator>=(const tuple<T...>&, const tuple<U...>&); // constexpr in C++14
-
-template <class... Types, class Alloc>
-  struct uses_allocator<tuple<Types...>, Alloc>;
-
-template <class... Types>
-  void
-  swap(tuple<Types...>& x, tuple<Types...>& y) noexcept(noexcept(x.swap(y)));
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__tuple>
-#include <cstddef>
-#include <type_traits>
-#include <__functional_base>
-#include <utility>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#ifndef _LIBCPP_CXX03_LANG
-
-
-// __tuple_leaf
-
-template <size_t _Ip, class _Hp,
-          bool=is_empty<_Hp>::value && !__libcpp_is_final<_Hp>::value
-         >
-class __tuple_leaf;
-
-template <size_t _Ip, class _Hp, bool _Ep>
-inline _LIBCPP_INLINE_VISIBILITY
-void swap(__tuple_leaf<_Ip, _Hp, _Ep>& __x, __tuple_leaf<_Ip, _Hp, _Ep>& __y)
-    _NOEXCEPT_(__is_nothrow_swappable<_Hp>::value)
-{
-    swap(__x.get(), __y.get());
-}
-
-template <size_t _Ip, class _Hp, bool>
-class __tuple_leaf
-{
-    _Hp __value_;
-
-    template <class _Tp>
-    static constexpr bool __can_bind_reference() {
-#if __has_keyword(__reference_binds_to_temporary)
-      return !__reference_binds_to_temporary(_Hp, _Tp);
-#else
-      return true;
-#endif
-    }
-
-    __tuple_leaf& operator=(const __tuple_leaf&);
-public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR __tuple_leaf()
-             _NOEXCEPT_(is_nothrow_default_constructible<_Hp>::value) : __value_()
-       {static_assert(!is_reference<_Hp>::value,
-              "Attempted to default construct a reference element in a tuple");}
-
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        __tuple_leaf(integral_constant<int, 0>, const _Alloc&)
-            : __value_()
-        {static_assert(!is_reference<_Hp>::value,
-              "Attempted to default construct a reference element in a tuple");}
-
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a)
-            : __value_(allocator_arg_t(), __a)
-        {static_assert(!is_reference<_Hp>::value,
-              "Attempted to default construct a reference element in a tuple");}
-
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a)
-            : __value_(__a)
-        {static_assert(!is_reference<_Hp>::value,
-              "Attempted to default construct a reference element in a tuple");}
-
-    template <class _Tp,
-              class = typename enable_if<
-                  __lazy_and<
-                      __lazy_not<is_same<typename __uncvref<_Tp>::type, __tuple_leaf>>
-                    , is_constructible<_Hp, _Tp>
-                    >::value
-                >::type
-            >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-        explicit __tuple_leaf(_Tp&& __t) _NOEXCEPT_((is_nothrow_constructible<_Hp, _Tp>::value))
-            : __value_(_VSTD::forward<_Tp>(__t))
-        {static_assert(__can_bind_reference<_Tp&&>(),
-       "Attempted construction of reference element binds to a temporary whose lifetime has ended");}
-
-    template <class _Tp, class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit __tuple_leaf(integral_constant<int, 0>, const _Alloc&, _Tp&& __t)
-            : __value_(_VSTD::forward<_Tp>(__t))
-        {static_assert(__can_bind_reference<_Tp&&>(),
-       "Attempted construction of reference element binds to a temporary whose lifetime has ended");}
-
-    template <class _Tp, class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a, _Tp&& __t)
-            : __value_(allocator_arg_t(), __a, _VSTD::forward<_Tp>(__t))
-        {static_assert(!is_reference<_Hp>::value,
-            "Attempted to uses-allocator construct a reference element in a tuple");}
-
-    template <class _Tp, class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a, _Tp&& __t)
-            : __value_(_VSTD::forward<_Tp>(__t), __a)
-        {static_assert(!is_reference<_Hp>::value,
-           "Attempted to uses-allocator construct a reference element in a tuple");}
-
-    __tuple_leaf(const __tuple_leaf& __t) = default;
-    __tuple_leaf(__tuple_leaf&& __t) = default;
-
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        __tuple_leaf&
-        operator=(_Tp&& __t) _NOEXCEPT_((is_nothrow_assignable<_Hp&, _Tp>::value))
-        {
-            __value_ = _VSTD::forward<_Tp>(__t);
-            return *this;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int swap(__tuple_leaf& __t) _NOEXCEPT_(__is_nothrow_swappable<__tuple_leaf>::value)
-    {
-        _VSTD::swap(*this, __t);
-        return 0;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11       _Hp& get()       _NOEXCEPT {return __value_;}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const _Hp& get() const _NOEXCEPT {return __value_;}
-};
-
-template <size_t _Ip, class _Hp>
-class __tuple_leaf<_Ip, _Hp, true>
-    : private _Hp
-{
-
-    __tuple_leaf& operator=(const __tuple_leaf&);
-public:
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR __tuple_leaf()
-             _NOEXCEPT_(is_nothrow_default_constructible<_Hp>::value) {}
-
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        __tuple_leaf(integral_constant<int, 0>, const _Alloc&) {}
-
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a)
-            : _Hp(allocator_arg_t(), __a) {}
-
-    template <class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a)
-            : _Hp(__a) {}
-
-    template <class _Tp,
-              class = typename enable_if<
-                  __lazy_and<
-                        __lazy_not<is_same<typename __uncvref<_Tp>::type, __tuple_leaf>>
-                      , is_constructible<_Hp, _Tp>
-                    >::value
-                >::type
-            >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-        explicit __tuple_leaf(_Tp&& __t) _NOEXCEPT_((is_nothrow_constructible<_Hp, _Tp>::value))
-            : _Hp(_VSTD::forward<_Tp>(__t)) {}
-
-    template <class _Tp, class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit __tuple_leaf(integral_constant<int, 0>, const _Alloc&, _Tp&& __t)
-            : _Hp(_VSTD::forward<_Tp>(__t)) {}
-
-    template <class _Tp, class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit __tuple_leaf(integral_constant<int, 1>, const _Alloc& __a, _Tp&& __t)
-            : _Hp(allocator_arg_t(), __a, _VSTD::forward<_Tp>(__t)) {}
-
-    template <class _Tp, class _Alloc>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit __tuple_leaf(integral_constant<int, 2>, const _Alloc& __a, _Tp&& __t)
-            : _Hp(_VSTD::forward<_Tp>(__t), __a) {}
-
-    __tuple_leaf(__tuple_leaf const &) = default;
-    __tuple_leaf(__tuple_leaf &&) = default;
-
-    template <class _Tp>
-        _LIBCPP_INLINE_VISIBILITY
-        __tuple_leaf&
-        operator=(_Tp&& __t) _NOEXCEPT_((is_nothrow_assignable<_Hp&, _Tp>::value))
-        {
-            _Hp::operator=(_VSTD::forward<_Tp>(__t));
-            return *this;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    int
-    swap(__tuple_leaf& __t) _NOEXCEPT_(__is_nothrow_swappable<__tuple_leaf>::value)
-    {
-        _VSTD::swap(*this, __t);
-        return 0;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11       _Hp& get()       _NOEXCEPT {return static_cast<_Hp&>(*this);}
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11 const _Hp& get() const _NOEXCEPT {return static_cast<const _Hp&>(*this);}
-};
-
-template <class ..._Tp>
-_LIBCPP_INLINE_VISIBILITY
-void __swallow(_Tp&&...) _NOEXCEPT {}
-
-template <class ..._Tp>
-struct __lazy_all : __all<_Tp::value...> {};
-
-template <class _Tp>
-struct __all_default_constructible;
-
-template <class ..._Tp>
-struct __all_default_constructible<__tuple_types<_Tp...>>
-    : __all<is_default_constructible<_Tp>::value...>
-{ };
-
-// __tuple_impl
-
-template<class _Indx, class ..._Tp> struct __tuple_impl;
-
-template<size_t ..._Indx, class ..._Tp>
-struct _LIBCPP_DECLSPEC_EMPTY_BASES __tuple_impl<__tuple_indices<_Indx...>, _Tp...>
-    : public __tuple_leaf<_Indx, _Tp>...
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR __tuple_impl()
-        _NOEXCEPT_(__all<is_nothrow_default_constructible<_Tp>::value...>::value) {}
-
-    template <size_t ..._Uf, class ..._Tf,
-              size_t ..._Ul, class ..._Tl, class ..._Up>
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-        explicit
-        __tuple_impl(__tuple_indices<_Uf...>, __tuple_types<_Tf...>,
-                     __tuple_indices<_Ul...>, __tuple_types<_Tl...>,
-                     _Up&&... __u)
-                     _NOEXCEPT_((__all<is_nothrow_constructible<_Tf, _Up>::value...>::value &&
-                                 __all<is_nothrow_default_constructible<_Tl>::value...>::value)) :
-            __tuple_leaf<_Uf, _Tf>(_VSTD::forward<_Up>(__u))...,
-            __tuple_leaf<_Ul, _Tl>()...
-            {}
-
-    template <class _Alloc, size_t ..._Uf, class ..._Tf,
-              size_t ..._Ul, class ..._Tl, class ..._Up>
-        _LIBCPP_INLINE_VISIBILITY
-        explicit
-        __tuple_impl(allocator_arg_t, const _Alloc& __a,
-                     __tuple_indices<_Uf...>, __tuple_types<_Tf...>,
-                     __tuple_indices<_Ul...>, __tuple_types<_Tl...>,
-                     _Up&&... __u) :
-            __tuple_leaf<_Uf, _Tf>(__uses_alloc_ctor<_Tf, _Alloc, _Up>(), __a,
-            _VSTD::forward<_Up>(__u))...,
-            __tuple_leaf<_Ul, _Tl>(__uses_alloc_ctor<_Tl, _Alloc>(), __a)...
-            {}
-
-    template <class _Tuple,
-              class = typename enable_if
-                      <
-                         __tuple_constructible<_Tuple, tuple<_Tp...> >::value
-                      >::type
-             >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-        __tuple_impl(_Tuple&& __t) _NOEXCEPT_((__all<is_nothrow_constructible<_Tp, typename tuple_element<_Indx,
-                                       typename __make_tuple_types<_Tuple>::type>::type>::value...>::value))
-            : __tuple_leaf<_Indx, _Tp>(_VSTD::forward<typename tuple_element<_Indx,
-                                       typename __make_tuple_types<_Tuple>::type>::type>(_VSTD::get<_Indx>(__t)))...
-            {}
-
-    template <class _Alloc, class _Tuple,
-              class = typename enable_if
-                      <
-                         __tuple_constructible<_Tuple, tuple<_Tp...> >::value
-                      >::type
-             >
-        _LIBCPP_INLINE_VISIBILITY
-        __tuple_impl(allocator_arg_t, const _Alloc& __a, _Tuple&& __t)
-            : __tuple_leaf<_Indx, _Tp>(__uses_alloc_ctor<_Tp, _Alloc, typename tuple_element<_Indx,
-                                       typename __make_tuple_types<_Tuple>::type>::type>(), __a,
-                                       _VSTD::forward<typename tuple_element<_Indx,
-                                       typename __make_tuple_types<_Tuple>::type>::type>(_VSTD::get<_Indx>(__t)))...
-            {}
-
-    template <class _Tuple>
-        _LIBCPP_INLINE_VISIBILITY
-        typename enable_if
-        <
-            __tuple_assignable<_Tuple, tuple<_Tp...> >::value,
-            __tuple_impl&
-        >::type
-        operator=(_Tuple&& __t) _NOEXCEPT_((__all<is_nothrow_assignable<_Tp&, typename tuple_element<_Indx,
-                                       typename __make_tuple_types<_Tuple>::type>::type>::value...>::value))
-        {
-            __swallow(__tuple_leaf<_Indx, _Tp>::operator=(_VSTD::forward<typename tuple_element<_Indx,
-                                       typename __make_tuple_types<_Tuple>::type>::type>(_VSTD::get<_Indx>(__t)))...);
-            return *this;
-        }
-
-    __tuple_impl(const __tuple_impl&) = default;
-    __tuple_impl(__tuple_impl&&) = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tuple_impl&
-    operator=(const __tuple_impl& __t) _NOEXCEPT_((__all<is_nothrow_copy_assignable<_Tp>::value...>::value))
-    {
-        __swallow(__tuple_leaf<_Indx, _Tp>::operator=(static_cast<const __tuple_leaf<_Indx, _Tp>&>(__t).get())...);
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __tuple_impl&
-    operator=(__tuple_impl&& __t) _NOEXCEPT_((__all<is_nothrow_move_assignable<_Tp>::value...>::value))
-    {
-        __swallow(__tuple_leaf<_Indx, _Tp>::operator=(_VSTD::forward<_Tp>(static_cast<__tuple_leaf<_Indx, _Tp>&>(__t).get()))...);
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(__tuple_impl& __t)
-        _NOEXCEPT_(__all<__is_nothrow_swappable<_Tp>::value...>::value)
-    {
-        __swallow(__tuple_leaf<_Indx, _Tp>::swap(static_cast<__tuple_leaf<_Indx, _Tp>&>(__t))...);
-    }
-};
-
-
-
-template <class ..._Tp>
-class _LIBCPP_TEMPLATE_VIS tuple
-{
-    typedef __tuple_impl<typename __make_tuple_indices<sizeof...(_Tp)>::type, _Tp...> _BaseT;
-
-    _BaseT __base_;
-
-#if defined(_LIBCPP_ENABLE_TUPLE_IMPLICIT_REDUCED_ARITY_EXTENSION)
-    static constexpr bool _EnableImplicitReducedArityExtension = true;
-#else
-    static constexpr bool _EnableImplicitReducedArityExtension = false;
-#endif
-
-    template <class ..._Args>
-    struct _PackExpandsToThisTuple : false_type {};
-
-    template <class _Arg>
-    struct _PackExpandsToThisTuple<_Arg>
-        : is_same<typename __uncvref<_Arg>::type, tuple> {};
-
-    template <bool _MaybeEnable, class _Dummy = void>
-    struct _CheckArgsConstructor : __check_tuple_constructor_fail {};
-
-    template <class _Dummy>
-    struct _CheckArgsConstructor<true, _Dummy>
-    {
-        template <class ..._Args>
-        static constexpr bool __enable_default() {
-            return __all<is_default_constructible<_Args>::value...>::value;
-        }
-
-        template <class ..._Args>
-        static constexpr bool __enable_explicit() {
-            return
-                __tuple_constructible<
-                    tuple<_Args...>,
-                    typename __make_tuple_types<tuple,
-                             sizeof...(_Args) < sizeof...(_Tp) ?
-                                 sizeof...(_Args) :
-                                 sizeof...(_Tp)>::type
-                >::value &&
-                !__tuple_convertible<
-                    tuple<_Args...>,
-                    typename __make_tuple_types<tuple,
-                             sizeof...(_Args) < sizeof...(_Tp) ?
-                                 sizeof...(_Args) :
-                                 sizeof...(_Tp)>::type
-                >::value &&
-                __all_default_constructible<
-                    typename __make_tuple_types<tuple, sizeof...(_Tp),
-                             sizeof...(_Args) < sizeof...(_Tp) ?
-                                 sizeof...(_Args) :
-                                 sizeof...(_Tp)>::type
-                >::value;
-        }
-
-        template <class ..._Args>
-        static constexpr bool __enable_implicit() {
-            return
-                __tuple_convertible<
-                    tuple<_Args...>,
-                    typename __make_tuple_types<tuple,
-                             sizeof...(_Args) < sizeof...(_Tp) ?
-                                 sizeof...(_Args) :
-                                 sizeof...(_Tp)>::type
-                >::value &&
-                __all_default_constructible<
-                    typename __make_tuple_types<tuple, sizeof...(_Tp),
-                             sizeof...(_Args) < sizeof...(_Tp) ?
-                                 sizeof...(_Args) :
-                                 sizeof...(_Tp)>::type
-                >::value;
-        }
-    };
-
-    template <bool _MaybeEnable,
-              bool = sizeof...(_Tp) == 1,
-              class _Dummy = void>
-    struct _CheckTupleLikeConstructor : __check_tuple_constructor_fail {};
-
-    template <class _Dummy>
-    struct _CheckTupleLikeConstructor<true, false, _Dummy>
-    {
-        template <class _Tuple>
-        static constexpr bool __enable_implicit() {
-            return __tuple_convertible<_Tuple, tuple>::value;
-        }
-
-        template <class _Tuple>
-        static constexpr bool __enable_explicit() {
-            return __tuple_constructible<_Tuple, tuple>::value
-               && !__tuple_convertible<_Tuple, tuple>::value;
-        }
-    };
-
-    template <class _Dummy>
-    struct _CheckTupleLikeConstructor<true, true, _Dummy>
-    {
-        // This trait is used to disable the tuple-like constructor when
-        // the UTypes... constructor should be selected instead.
-        // See LWG issue #2549.
-        template <class _Tuple>
-        using _PreferTupleLikeConstructor = __lazy_or<
-            // Don't attempt the two checks below if the tuple we are given
-            // has the same type as this tuple.
-            is_same<typename __uncvref<_Tuple>::type, tuple>,
-            __lazy_and<
-                __lazy_not<is_constructible<_Tp..., _Tuple>>,
-                __lazy_not<is_convertible<_Tuple, _Tp...>>
-            >
-        >;
-
-        template <class _Tuple>
-        static constexpr bool __enable_implicit() {
-            return __lazy_and<
-                __tuple_convertible<_Tuple, tuple>,
-                _PreferTupleLikeConstructor<_Tuple>
-            >::value;
-        }
-
-        template <class _Tuple>
-        static constexpr bool __enable_explicit() {
-            return __lazy_and<
-                __tuple_constructible<_Tuple, tuple>,
-                _PreferTupleLikeConstructor<_Tuple>,
-                __lazy_not<__tuple_convertible<_Tuple, tuple>>
-            >::value;
-        }
-    };
-
-    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
-        typename tuple_element<_Jp, tuple<_Up...> >::type& get(tuple<_Up...>&) _NOEXCEPT;
-    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
-        const typename tuple_element<_Jp, tuple<_Up...> >::type& get(const tuple<_Up...>&) _NOEXCEPT;
-    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
-        typename tuple_element<_Jp, tuple<_Up...> >::type&& get(tuple<_Up...>&&) _NOEXCEPT;
-    template <size_t _Jp, class ..._Up> friend _LIBCPP_CONSTEXPR_AFTER_CXX11
-        const typename tuple_element<_Jp, tuple<_Up...> >::type&& get(const tuple<_Up...>&&) _NOEXCEPT;
-public:
-
-    template <bool _Dummy = true, class = typename enable_if<
-        _CheckArgsConstructor<_Dummy>::template __enable_default<_Tp...>()
-    >::type>
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR tuple()
-        _NOEXCEPT_(__all<is_nothrow_default_constructible<_Tp>::value...>::value) {}
-
-    tuple(tuple const&) = default;
-    tuple(tuple&&) = default;
-
-    template <class _AllocArgT, class _Alloc, bool _Dummy = true, class = typename enable_if<
-        __lazy_and<
-            is_same<allocator_arg_t, _AllocArgT>,
-            __lazy_all<__dependent_type<is_default_constructible<_Tp>, _Dummy>...>
-       >::value
-    >::type>
-    _LIBCPP_INLINE_VISIBILITY
-    tuple(_AllocArgT, _Alloc const& __a)
-      : __base_(allocator_arg_t(), __a,
-                    __tuple_indices<>(), __tuple_types<>(),
-                    typename __make_tuple_indices<sizeof...(_Tp), 0>::type(),
-                    __tuple_types<_Tp...>()) {}
-
-    template <bool _Dummy = true,
-              typename enable_if
-                      <
-                         _CheckArgsConstructor<
-                            _Dummy
-                         >::template __enable_implicit<_Tp const&...>(),
-                         bool
-                      >::type = false
-        >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    tuple(const _Tp& ... __t) _NOEXCEPT_((__all<is_nothrow_copy_constructible<_Tp>::value...>::value))
-        : __base_(typename __make_tuple_indices<sizeof...(_Tp)>::type(),
-                typename __make_tuple_types<tuple, sizeof...(_Tp)>::type(),
-                typename __make_tuple_indices<0>::type(),
-                typename __make_tuple_types<tuple, 0>::type(),
-                __t...
-               ) {}
-
-    template <bool _Dummy = true,
-              typename enable_if
-                      <
-                         _CheckArgsConstructor<
-                            _Dummy
-                         >::template __enable_explicit<_Tp const&...>(),
-                         bool
-                      >::type = false
-        >
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    explicit tuple(const _Tp& ... __t) _NOEXCEPT_((__all<is_nothrow_copy_constructible<_Tp>::value...>::value))
-        : __base_(typename __make_tuple_indices<sizeof...(_Tp)>::type(),
-                typename __make_tuple_types<tuple, sizeof...(_Tp)>::type(),
-                typename __make_tuple_indices<0>::type(),
-                typename __make_tuple_types<tuple, 0>::type(),
-                __t...
-               ) {}
-
-    template <class _Alloc, bool _Dummy = true,
-              typename enable_if
-                      <
-                         _CheckArgsConstructor<
-                            _Dummy
-                         >::template __enable_implicit<_Tp const&...>(),
-                         bool
-                      >::type = false
-        >
-      _LIBCPP_INLINE_VISIBILITY
-      tuple(allocator_arg_t, const _Alloc& __a, const _Tp& ... __t)
-        : __base_(allocator_arg_t(), __a,
-                typename __make_tuple_indices<sizeof...(_Tp)>::type(),
-                typename __make_tuple_types<tuple, sizeof...(_Tp)>::type(),
-                typename __make_tuple_indices<0>::type(),
-                typename __make_tuple_types<tuple, 0>::type(),
-                __t...
-               ) {}
-
-    template <class _Alloc, bool _Dummy = true,
-              typename enable_if
-                      <
-                         _CheckArgsConstructor<
-                            _Dummy
-                         >::template __enable_explicit<_Tp const&...>(),
-                         bool
-                      >::type = false
-        >
-      _LIBCPP_INLINE_VISIBILITY
-      explicit
-      tuple(allocator_arg_t, const _Alloc& __a, const _Tp& ... __t)
-        : __base_(allocator_arg_t(), __a,
-                typename __make_tuple_indices<sizeof...(_Tp)>::type(),
-                typename __make_tuple_types<tuple, sizeof...(_Tp)>::type(),
-                typename __make_tuple_indices<0>::type(),
-                typename __make_tuple_types<tuple, 0>::type(),
-                __t...
-               ) {}
-
-    template <class ..._Up,
-              bool _PackIsTuple = _PackExpandsToThisTuple<_Up...>::value,
-              typename enable_if
-                      <
-                         _CheckArgsConstructor<
-                             sizeof...(_Up) == sizeof...(_Tp)
-                             && !_PackIsTuple
-                         >::template __enable_implicit<_Up...>() ||
-                        _CheckArgsConstructor<
-                            _EnableImplicitReducedArityExtension
-                            && sizeof...(_Up) < sizeof...(_Tp)
-                            && !_PackIsTuple
-                         >::template __enable_implicit<_Up...>(),
-                         bool
-                      >::type = false
-             >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-        tuple(_Up&&... __u)
-            _NOEXCEPT_((
-                is_nothrow_constructible<_BaseT,
-                    typename __make_tuple_indices<sizeof...(_Up)>::type,
-                    typename __make_tuple_types<tuple, sizeof...(_Up)>::type,
-                    typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type,
-                    typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type,
-                    _Up...
-                >::value
-            ))
-            : __base_(typename __make_tuple_indices<sizeof...(_Up)>::type(),
-                    typename __make_tuple_types<tuple, sizeof...(_Up)>::type(),
-                    typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type(),
-                    typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type(),
-                    _VSTD::forward<_Up>(__u)...) {}
-
-    template <class ..._Up,
-              typename enable_if
-                      <
-                         _CheckArgsConstructor<
-                             sizeof...(_Up) <= sizeof...(_Tp)
-                             && !_PackExpandsToThisTuple<_Up...>::value
-                         >::template __enable_explicit<_Up...>() ||
-                         _CheckArgsConstructor<
-                            !_EnableImplicitReducedArityExtension
-                            && sizeof...(_Up) < sizeof...(_Tp)
-                            && !_PackExpandsToThisTuple<_Up...>::value
-                         >::template __enable_implicit<_Up...>(),
-                         bool
-                      >::type = false
-             >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-        explicit
-        tuple(_Up&&... __u)
-            _NOEXCEPT_((
-                is_nothrow_constructible<_BaseT,
-                    typename __make_tuple_indices<sizeof...(_Up)>::type,
-                    typename __make_tuple_types<tuple, sizeof...(_Up)>::type,
-                    typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type,
-                    typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type,
-                    _Up...
-                >::value
-            ))
-            : __base_(typename __make_tuple_indices<sizeof...(_Up)>::type(),
-                    typename __make_tuple_types<tuple, sizeof...(_Up)>::type(),
-                    typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type(),
-                    typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type(),
-                    _VSTD::forward<_Up>(__u)...) {}
-
-    template <class _Alloc, class ..._Up,
-              typename enable_if
-                      <
-                         _CheckArgsConstructor<
-                             sizeof...(_Up) == sizeof...(_Tp) &&
-                             !_PackExpandsToThisTuple<_Up...>::value
-                         >::template __enable_implicit<_Up...>(),
-                         bool
-                      >::type = false
-             >
-        _LIBCPP_INLINE_VISIBILITY
-        tuple(allocator_arg_t, const _Alloc& __a, _Up&&... __u)
-            : __base_(allocator_arg_t(), __a,
-                    typename __make_tuple_indices<sizeof...(_Up)>::type(),
-                    typename __make_tuple_types<tuple, sizeof...(_Up)>::type(),
-                    typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type(),
-                    typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type(),
-                    _VSTD::forward<_Up>(__u)...) {}
-
-    template <class _Alloc, class ..._Up,
-              typename enable_if
-                      <
-                         _CheckArgsConstructor<
-                             sizeof...(_Up) == sizeof...(_Tp) &&
-                             !_PackExpandsToThisTuple<_Up...>::value
-                         >::template __enable_explicit<_Up...>(),
-                         bool
-                      >::type = false
-             >
-        _LIBCPP_INLINE_VISIBILITY
-        explicit
-        tuple(allocator_arg_t, const _Alloc& __a, _Up&&... __u)
-            : __base_(allocator_arg_t(), __a,
-                    typename __make_tuple_indices<sizeof...(_Up)>::type(),
-                    typename __make_tuple_types<tuple, sizeof...(_Up)>::type(),
-                    typename __make_tuple_indices<sizeof...(_Tp), sizeof...(_Up)>::type(),
-                    typename __make_tuple_types<tuple, sizeof...(_Tp), sizeof...(_Up)>::type(),
-                    _VSTD::forward<_Up>(__u)...) {}
-
-    template <class _Tuple,
-              typename enable_if
-                      <
-                         _CheckTupleLikeConstructor<
-                             __tuple_like_with_size<_Tuple, sizeof...(_Tp)>::value
-                             && !_PackExpandsToThisTuple<_Tuple>::value
-                         >::template __enable_implicit<_Tuple>(),
-                         bool
-                      >::type = false
-             >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-        tuple(_Tuple&& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, _Tuple>::value))
-            : __base_(_VSTD::forward<_Tuple>(__t)) {}
-
-    template <class _Tuple,
-              typename enable_if
-                      <
-                         _CheckTupleLikeConstructor<
-                             __tuple_like_with_size<_Tuple, sizeof...(_Tp)>::value
-                             && !_PackExpandsToThisTuple<_Tuple>::value
-                         >::template __enable_explicit<_Tuple>(),
-                         bool
-                      >::type = false
-             >
-        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-        explicit
-        tuple(_Tuple&& __t) _NOEXCEPT_((is_nothrow_constructible<_BaseT, _Tuple>::value))
-            : __base_(_VSTD::forward<_Tuple>(__t)) {}
-
-    template <class _Alloc, class _Tuple,
-              typename enable_if
-                      <
-                         _CheckTupleLikeConstructor<
-                             __tuple_like_with_size<_Tuple, sizeof...(_Tp)>::value
-                         >::template __enable_implicit<_Tuple>(),
-                         bool
-                      >::type = false
-             >
-        _LIBCPP_INLINE_VISIBILITY
-        tuple(allocator_arg_t, const _Alloc& __a, _Tuple&& __t)
-            : __base_(allocator_arg_t(), __a, _VSTD::forward<_Tuple>(__t)) {}
-
-    template <class _Alloc, class _Tuple,
-              typename enable_if
-                      <
-                         _CheckTupleLikeConstructor<
-                             __tuple_like_with_size<_Tuple, sizeof...(_Tp)>::value
-                         >::template __enable_explicit<_Tuple>(),
-                         bool
-                      >::type = false
-             >
-        _LIBCPP_INLINE_VISIBILITY
-        explicit
-        tuple(allocator_arg_t, const _Alloc& __a, _Tuple&& __t)
-            : __base_(allocator_arg_t(), __a, _VSTD::forward<_Tuple>(__t)) {}
-
-    using _CanCopyAssign = __all<is_copy_assignable<_Tp>::value...>;
-    using _CanMoveAssign = __all<is_move_assignable<_Tp>::value...>;
-
-    _LIBCPP_INLINE_VISIBILITY
-    tuple& operator=(typename conditional<_CanCopyAssign::value, tuple, __nat>::type const& __t)
-        _NOEXCEPT_((__all<is_nothrow_copy_assignable<_Tp>::value...>::value))
-    {
-        __base_.operator=(__t.__base_);
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    tuple& operator=(typename conditional<_CanMoveAssign::value, tuple, __nat>::type&& __t)
-        _NOEXCEPT_((__all<is_nothrow_move_assignable<_Tp>::value...>::value))
-    {
-        __base_.operator=(static_cast<_BaseT&&>(__t.__base_));
-        return *this;
-    }
-
-    template <class _Tuple,
-              class = typename enable_if
-                      <
-                         __tuple_assignable<_Tuple, tuple>::value
-                      >::type
-             >
-        _LIBCPP_INLINE_VISIBILITY
-        tuple&
-        operator=(_Tuple&& __t) _NOEXCEPT_((is_nothrow_assignable<_BaseT&, _Tuple>::value))
-        {
-            __base_.operator=(_VSTD::forward<_Tuple>(__t));
-            return *this;
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(tuple& __t) _NOEXCEPT_(__all<__is_nothrow_swappable<_Tp>::value...>::value)
-        {__base_.swap(__t.__base_);}
-};
-
-template <>
-class _LIBCPP_TEMPLATE_VIS tuple<>
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    _LIBCPP_CONSTEXPR tuple() _NOEXCEPT {}
-    template <class _Alloc>
-    _LIBCPP_INLINE_VISIBILITY
-        tuple(allocator_arg_t, const _Alloc&) _NOEXCEPT {}
-    template <class _Alloc>
-    _LIBCPP_INLINE_VISIBILITY
-        tuple(allocator_arg_t, const _Alloc&, const tuple&) _NOEXCEPT {}
-    template <class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-        tuple(array<_Up, 0>) _NOEXCEPT {}
-    template <class _Alloc, class _Up>
-    _LIBCPP_INLINE_VISIBILITY
-        tuple(allocator_arg_t, const _Alloc&, array<_Up, 0>) _NOEXCEPT {}
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(tuple&) _NOEXCEPT {}
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-// NOTE: These are not yet standardized, but are required to simulate the
-// implicit deduction guide that should be generated had libc++ declared the
-// tuple-like constructors "correctly"
-template <class _Alloc, class ..._Args>
-tuple(allocator_arg_t, const _Alloc&, tuple<_Args...> const&) -> tuple<_Args...>;
-template <class _Alloc, class ..._Args>
-tuple(allocator_arg_t, const _Alloc&, tuple<_Args...>&&) -> tuple<_Args...>;
-#endif
-
-template <class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __all<__is_swappable<_Tp>::value...>::value,
-    void
->::type
-swap(tuple<_Tp...>& __t, tuple<_Tp...>& __u)
-                 _NOEXCEPT_(__all<__is_nothrow_swappable<_Tp>::value...>::value)
-    {__t.swap(__u);}
-
-// get
-
-template <size_t _Ip, class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename tuple_element<_Ip, tuple<_Tp...> >::type&
-get(tuple<_Tp...>& __t) _NOEXCEPT
-{
-    typedef typename tuple_element<_Ip, tuple<_Tp...> >::type type;
-    return static_cast<__tuple_leaf<_Ip, type>&>(__t.__base_).get();
-}
-
-template <size_t _Ip, class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const typename tuple_element<_Ip, tuple<_Tp...> >::type&
-get(const tuple<_Tp...>& __t) _NOEXCEPT
-{
-    typedef typename tuple_element<_Ip, tuple<_Tp...> >::type type;
-    return static_cast<const __tuple_leaf<_Ip, type>&>(__t.__base_).get();
-}
-
-template <size_t _Ip, class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename tuple_element<_Ip, tuple<_Tp...> >::type&&
-get(tuple<_Tp...>&& __t) _NOEXCEPT
-{
-    typedef typename tuple_element<_Ip, tuple<_Tp...> >::type type;
-    return static_cast<type&&>(
-             static_cast<__tuple_leaf<_Ip, type>&&>(__t.__base_).get());
-}
-
-template <size_t _Ip, class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const typename tuple_element<_Ip, tuple<_Tp...> >::type&&
-get(const tuple<_Tp...>&& __t) _NOEXCEPT
-{
-    typedef typename tuple_element<_Ip, tuple<_Tp...> >::type type;
-    return static_cast<const type&&>(
-             static_cast<const __tuple_leaf<_Ip, type>&&>(__t.__base_).get());
-}
-
-#if _LIBCPP_STD_VER > 11
-
-namespace __find_detail {
-
-static constexpr size_t __not_found = -1;
-static constexpr size_t __ambiguous = __not_found - 1;
-
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr size_t __find_idx_return(size_t __curr_i, size_t __res, bool __matches) {
-    return !__matches ? __res :
-        (__res == __not_found ? __curr_i : __ambiguous);
-}
-
-template <size_t _Nx>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr size_t __find_idx(size_t __i, const bool (&__matches)[_Nx]) {
-  return __i == _Nx ? __not_found :
-      __find_idx_return(__i, __find_idx(__i + 1, __matches), __matches[__i]);
-}
-
-template <class _T1, class ..._Args>
-struct __find_exactly_one_checked {
-    static constexpr bool __matches[sizeof...(_Args)] = {is_same<_T1, _Args>::value...};
-    static constexpr size_t value = __find_detail::__find_idx(0, __matches);
-    static_assert(value != __not_found, "type not found in type list" );
-    static_assert(value != __ambiguous, "type occurs more than once in type list");
-};
-
-template <class _T1>
-struct __find_exactly_one_checked<_T1> {
-    static_assert(!is_same<_T1, _T1>::value, "type not in empty type list");
-};
-
-} // namespace __find_detail;
-
-template <typename _T1, typename... _Args>
-struct __find_exactly_one_t
-    : public __find_detail::__find_exactly_one_checked<_T1, _Args...> {
-};
-
-template <class _T1, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1& get(tuple<_Args...>& __tup) noexcept
-{
-    return _VSTD::get<__find_exactly_one_t<_T1, _Args...>::value>(__tup);
-}
-
-template <class _T1, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 const& get(tuple<_Args...> const& __tup) noexcept
-{
-    return _VSTD::get<__find_exactly_one_t<_T1, _Args...>::value>(__tup);
-}
-
-template <class _T1, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1&& get(tuple<_Args...>&& __tup) noexcept
-{
-    return _VSTD::get<__find_exactly_one_t<_T1, _Args...>::value>(_VSTD::move(__tup));
-}
-
-template <class _T1, class... _Args>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 const&& get(tuple<_Args...> const&& __tup) noexcept
-{
-    return _VSTD::get<__find_exactly_one_t<_T1, _Args...>::value>(_VSTD::move(__tup));
-}
-
-#endif
-
-// tie
-
-template <class ..._Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-tuple<_Tp&...>
-tie(_Tp&... __t) _NOEXCEPT
-{
-    return tuple<_Tp&...>(__t...);
-}
-
-template <class _Up>
-struct __ignore_t
-{
-    template <class _Tp>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const __ignore_t& operator=(_Tp&&) const {return *this;}
-};
-
-namespace {
-  _LIBCPP_INLINE_VAR constexpr __ignore_t<unsigned char> ignore = __ignore_t<unsigned char>();
-}
-
-template <class... _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-tuple<typename __unwrap_ref_decay<_Tp>::type...>
-make_tuple(_Tp&&... __t)
-{
-    return tuple<typename __unwrap_ref_decay<_Tp>::type...>(_VSTD::forward<_Tp>(__t)...);
-}
-
-template <class... _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-tuple<_Tp&&...>
-forward_as_tuple(_Tp&&... __t) _NOEXCEPT
-{
-    return tuple<_Tp&&...>(_VSTD::forward<_Tp>(__t)...);
-}
-
-template <size_t _Ip>
-struct __tuple_equal
-{
-    template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _Tp& __x, const _Up& __y)
-    {
-        return __tuple_equal<_Ip - 1>()(__x, __y) && _VSTD::get<_Ip-1>(__x) == _VSTD::get<_Ip-1>(__y);
-    }
-};
-
-template <>
-struct __tuple_equal<0>
-{
-    template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _Tp&, const _Up&)
-    {
-        return true;
-    }
-};
-
-template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator==(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
-{
-    return __tuple_equal<sizeof...(_Tp)>()(__x, __y);
-}
-
-template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator!=(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
-{
-    return !(__x == __y);
-}
-
-template <size_t _Ip>
-struct __tuple_less
-{
-    template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _Tp& __x, const _Up& __y)
-    {
-        const size_t __idx = tuple_size<_Tp>::value - _Ip;
-        if (_VSTD::get<__idx>(__x) < _VSTD::get<__idx>(__y))
-            return true;
-        if (_VSTD::get<__idx>(__y) < _VSTD::get<__idx>(__x))
-            return false;
-        return __tuple_less<_Ip-1>()(__x, __y);
-    }
-};
-
-template <>
-struct __tuple_less<0>
-{
-    template <class _Tp, class _Up>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    bool operator()(const _Tp&, const _Up&)
-    {
-        return false;
-    }
-};
-
-template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator<(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
-{
-    return __tuple_less<sizeof...(_Tp)>()(__x, __y);
-}
-
-template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator>(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
-{
-    return __y < __x;
-}
-
-template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator>=(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class ..._Tp, class ..._Up>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator<=(const tuple<_Tp...>& __x, const tuple<_Up...>& __y)
-{
-    return !(__y < __x);
-}
-
-// tuple_cat
-
-template <class _Tp, class _Up> struct __tuple_cat_type;
-
-template <class ..._Ttypes, class ..._Utypes>
-struct __tuple_cat_type<tuple<_Ttypes...>, __tuple_types<_Utypes...> >
-{
-    typedef tuple<_Ttypes..., _Utypes...> type;
-};
-
-template <class _ResultTuple, bool _Is_Tuple0TupleLike, class ..._Tuples>
-struct __tuple_cat_return_1
-{
-};
-
-template <class ..._Types, class _Tuple0>
-struct __tuple_cat_return_1<tuple<_Types...>, true, _Tuple0>
-{
-    typedef typename __tuple_cat_type<tuple<_Types...>,
-            typename __make_tuple_types<typename remove_reference<_Tuple0>::type>::type>::type
-                                                                           type;
-};
-
-template <class ..._Types, class _Tuple0, class _Tuple1, class ..._Tuples>
-struct __tuple_cat_return_1<tuple<_Types...>, true, _Tuple0, _Tuple1, _Tuples...>
-    : public __tuple_cat_return_1<
-                 typename __tuple_cat_type<
-                     tuple<_Types...>,
-                     typename __make_tuple_types<typename remove_reference<_Tuple0>::type>::type
-                 >::type,
-                 __tuple_like<typename remove_reference<_Tuple1>::type>::value,
-                 _Tuple1, _Tuples...>
-{
-};
-
-template <class ..._Tuples> struct __tuple_cat_return;
-
-template <class _Tuple0, class ..._Tuples>
-struct __tuple_cat_return<_Tuple0, _Tuples...>
-    : public __tuple_cat_return_1<tuple<>,
-         __tuple_like<typename remove_reference<_Tuple0>::type>::value, _Tuple0,
-                                                                     _Tuples...>
-{
-};
-
-template <>
-struct __tuple_cat_return<>
-{
-    typedef tuple<> type;
-};
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-tuple<>
-tuple_cat()
-{
-    return tuple<>();
-}
-
-template <class _Rp, class _Indices, class _Tuple0, class ..._Tuples>
-struct __tuple_cat_return_ref_imp;
-
-template <class ..._Types, size_t ..._I0, class _Tuple0>
-struct __tuple_cat_return_ref_imp<tuple<_Types...>, __tuple_indices<_I0...>, _Tuple0>
-{
-    typedef typename remove_reference<_Tuple0>::type _T0;
-    typedef tuple<_Types..., typename __apply_cv<_Tuple0,
-                          typename tuple_element<_I0, _T0>::type>::type&&...> type;
-};
-
-template <class ..._Types, size_t ..._I0, class _Tuple0, class _Tuple1, class ..._Tuples>
-struct __tuple_cat_return_ref_imp<tuple<_Types...>, __tuple_indices<_I0...>,
-                                  _Tuple0, _Tuple1, _Tuples...>
-    : public __tuple_cat_return_ref_imp<
-         tuple<_Types..., typename __apply_cv<_Tuple0,
-               typename tuple_element<_I0,
-                  typename remove_reference<_Tuple0>::type>::type>::type&&...>,
-         typename __make_tuple_indices<tuple_size<typename
-                                 remove_reference<_Tuple1>::type>::value>::type,
-         _Tuple1, _Tuples...>
-{
-};
-
-template <class _Tuple0, class ..._Tuples>
-struct __tuple_cat_return_ref
-    : public __tuple_cat_return_ref_imp<tuple<>,
-               typename __make_tuple_indices<
-                        tuple_size<typename remove_reference<_Tuple0>::type>::value
-               >::type, _Tuple0, _Tuples...>
-{
-};
-
-template <class _Types, class _I0, class _J0>
-struct __tuple_cat;
-
-template <class ..._Types, size_t ..._I0, size_t ..._J0>
-struct __tuple_cat<tuple<_Types...>, __tuple_indices<_I0...>, __tuple_indices<_J0...> >
-{
-    template <class _Tuple0>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    typename __tuple_cat_return_ref<tuple<_Types...>&&, _Tuple0&&>::type
-    operator()(tuple<_Types...> __t, _Tuple0&& __t0)
-    {
-        return forward_as_tuple(_VSTD::forward<_Types>(_VSTD::get<_I0>(__t))...,
-                                      _VSTD::get<_J0>(_VSTD::forward<_Tuple0>(__t0))...);
-    }
-
-    template <class _Tuple0, class _Tuple1, class ..._Tuples>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    typename __tuple_cat_return_ref<tuple<_Types...>&&, _Tuple0&&, _Tuple1&&, _Tuples&&...>::type
-    operator()(tuple<_Types...> __t, _Tuple0&& __t0, _Tuple1&& __t1, _Tuples&& ...__tpls)
-    {
-        typedef typename remove_reference<_Tuple0>::type _T0;
-        typedef typename remove_reference<_Tuple1>::type _T1;
-        return __tuple_cat<
-           tuple<_Types..., typename __apply_cv<_Tuple0, typename tuple_element<_J0, _T0>::type>::type&&...>,
-           typename __make_tuple_indices<sizeof ...(_Types) + tuple_size<_T0>::value>::type,
-           typename __make_tuple_indices<tuple_size<_T1>::value>::type>()
-                           (forward_as_tuple(
-                              _VSTD::forward<_Types>(_VSTD::get<_I0>(__t))...,
-                              _VSTD::get<_J0>(_VSTD::forward<_Tuple0>(__t0))...
-                            ),
-                            _VSTD::forward<_Tuple1>(__t1),
-                            _VSTD::forward<_Tuples>(__tpls)...);
-    }
-};
-
-template <class _Tuple0, class... _Tuples>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename __tuple_cat_return<_Tuple0, _Tuples...>::type
-tuple_cat(_Tuple0&& __t0, _Tuples&&... __tpls)
-{
-    typedef typename remove_reference<_Tuple0>::type _T0;
-    return __tuple_cat<tuple<>, __tuple_indices<>,
-                  typename __make_tuple_indices<tuple_size<_T0>::value>::type>()
-                  (tuple<>(), _VSTD::forward<_Tuple0>(__t0),
-                                            _VSTD::forward<_Tuples>(__tpls)...);
-}
-
-template <class ..._Tp, class _Alloc>
-struct _LIBCPP_TEMPLATE_VIS uses_allocator<tuple<_Tp...>, _Alloc>
-    : true_type {};
-
-template <class _T1, class _T2>
-template <class... _Args1, class... _Args2, size_t ..._I1, size_t ..._I2>
-inline _LIBCPP_INLINE_VISIBILITY
-pair<_T1, _T2>::pair(piecewise_construct_t,
-                     tuple<_Args1...>& __first_args, tuple<_Args2...>& __second_args,
-                     __tuple_indices<_I1...>, __tuple_indices<_I2...>)
-    :  first(_VSTD::forward<_Args1>(_VSTD::get<_I1>( __first_args))...),
-      second(_VSTD::forward<_Args2>(_VSTD::get<_I2>(__second_args))...)
-{
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr size_t tuple_size_v = tuple_size<_Tp>::value;
-
-#define _LIBCPP_NOEXCEPT_RETURN(...) noexcept(noexcept(__VA_ARGS__)) { return __VA_ARGS__; }
-
-template <class _Fn, class _Tuple, size_t ..._Id>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr decltype(auto) __apply_tuple_impl(_Fn && __f, _Tuple && __t,
-                                            __tuple_indices<_Id...>)
-_LIBCPP_NOEXCEPT_RETURN(
-    _VSTD::__invoke_constexpr(
-        _VSTD::forward<_Fn>(__f),
-        _VSTD::get<_Id>(_VSTD::forward<_Tuple>(__t))...)
-)
-
-template <class _Fn, class _Tuple>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr decltype(auto) apply(_Fn && __f, _Tuple && __t)
-_LIBCPP_NOEXCEPT_RETURN(
-    _VSTD::__apply_tuple_impl(
-        _VSTD::forward<_Fn>(__f), _VSTD::forward<_Tuple>(__t),
-        typename __make_tuple_indices<tuple_size_v<remove_reference_t<_Tuple>>>::type{})
-)
-
-template <class _Tp, class _Tuple, size_t... _Idx>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _Tp __make_from_tuple_impl(_Tuple&& __t, __tuple_indices<_Idx...>)
-_LIBCPP_NOEXCEPT_RETURN(
-    _Tp(_VSTD::get<_Idx>(_VSTD::forward<_Tuple>(__t))...)
-)
-
-template <class _Tp, class _Tuple>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _Tp make_from_tuple(_Tuple&& __t)
-_LIBCPP_NOEXCEPT_RETURN(
-    _VSTD::__make_from_tuple_impl<_Tp>(_VSTD::forward<_Tuple>(__t),
-        typename __make_tuple_indices<tuple_size_v<remove_reference_t<_Tuple>>>::type{})
-)
-
-#undef _LIBCPP_NOEXCEPT_RETURN
-
-#endif // _LIBCPP_STD_VER > 14
-
-#endif // !defined(_LIBCPP_CXX03_LANG)
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_TUPLE
diff --git a/lib/libcxx/include/type_traits b/lib/libcxx/include/type_traits
deleted file mode 100644
index 8b30511a4ec..00000000000
--- a/lib/libcxx/include/type_traits
+++ /dev/null
@@ -1,4863 +0,0 @@
-// -*- C++ -*-
-//===------------------------ type_traits ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_TYPE_TRAITS
-#define _LIBCPP_TYPE_TRAITS
-
-/*
-    type_traits synopsis
-
-namespace std
-{
-
-    // helper class:
-    template <class T, T v> struct integral_constant;
-    typedef integral_constant<bool, true>  true_type;   // C++11
-    typedef integral_constant<bool, false> false_type;  // C++11
-
-    template <bool B>                                   // C++14
-    using bool_constant = integral_constant<bool, B>;   // C++14
-    typedef bool_constant<true> true_type;              // C++14
-    typedef bool_constant<false> false_type;            // C++14
-
-    // helper traits
-    template <bool, class T = void> struct enable_if;
-    template <bool, class T, class F> struct conditional;
-
-    // Primary classification traits:
-    template <class T> struct is_void;
-    template <class T> struct is_null_pointer;  // C++14
-    template <class T> struct is_integral;
-    template <class T> struct is_floating_point;
-    template <class T> struct is_array;
-    template <class T> struct is_pointer;
-    template <class T> struct is_lvalue_reference;
-    template <class T> struct is_rvalue_reference;
-    template <class T> struct is_member_object_pointer;
-    template <class T> struct is_member_function_pointer;
-    template <class T> struct is_enum;
-    template <class T> struct is_union;
-    template <class T> struct is_class;
-    template <class T> struct is_function;
-
-    // Secondary classification traits:
-    template <class T> struct is_reference;
-    template <class T> struct is_arithmetic;
-    template <class T> struct is_fundamental;
-    template <class T> struct is_member_pointer;
-    template <class T> struct is_scalar;
-    template <class T> struct is_object;
-    template <class T> struct is_compound;
-
-    // Const-volatile properties and transformations:
-    template <class T> struct is_const;
-    template <class T> struct is_volatile;
-    template <class T> struct remove_const;
-    template <class T> struct remove_volatile;
-    template <class T> struct remove_cv;
-    template <class T> struct add_const;
-    template <class T> struct add_volatile;
-    template <class T> struct add_cv;
-
-    // Reference transformations:
-    template <class T> struct remove_reference;
-    template <class T> struct add_lvalue_reference;
-    template <class T> struct add_rvalue_reference;
-
-    // Pointer transformations:
-    template <class T> struct remove_pointer;
-    template <class T> struct add_pointer;
-
-    template<class T> struct type_identity;                     // C++20
-    template<class T>
-      using type_identity_t = typename type_identity<T>::type;  // C++20
-
-    // Integral properties:
-    template <class T> struct is_signed;
-    template <class T> struct is_unsigned;
-    template <class T> struct make_signed;
-    template <class T> struct make_unsigned;
-
-    // Array properties and transformations:
-    template <class T> struct rank;
-    template <class T, unsigned I = 0> struct extent;
-    template <class T> struct remove_extent;
-    template <class T> struct remove_all_extents;
-
-    // Member introspection:
-    template <class T> struct is_pod;
-    template <class T> struct is_trivial;
-    template <class T> struct is_trivially_copyable;
-    template <class T> struct is_standard_layout;
-    template <class T> struct is_literal_type;
-    template <class T> struct is_empty;
-    template <class T> struct is_polymorphic;
-    template <class T> struct is_abstract;
-    template <class T> struct is_final; // C++14
-    template <class T> struct is_aggregate; // C++17
-
-    template <class T, class... Args> struct is_constructible;
-    template <class T>                struct is_default_constructible;
-    template <class T>                struct is_copy_constructible;
-    template <class T>                struct is_move_constructible;
-    template <class T, class U>       struct is_assignable;
-    template <class T>                struct is_copy_assignable;
-    template <class T>                struct is_move_assignable;
-    template <class T, class U>       struct is_swappable_with;       // C++17
-    template <class T>                struct is_swappable;            // C++17
-    template <class T>                struct is_destructible;
-
-    template <class T, class... Args> struct is_trivially_constructible;
-    template <class T>                struct is_trivially_default_constructible;
-    template <class T>                struct is_trivially_copy_constructible;
-    template <class T>                struct is_trivially_move_constructible;
-    template <class T, class U>       struct is_trivially_assignable;
-    template <class T>                struct is_trivially_copy_assignable;
-    template <class T>                struct is_trivially_move_assignable;
-    template <class T>                struct is_trivially_destructible;
-
-    template <class T, class... Args> struct is_nothrow_constructible;
-    template <class T>                struct is_nothrow_default_constructible;
-    template <class T>                struct is_nothrow_copy_constructible;
-    template <class T>                struct is_nothrow_move_constructible;
-    template <class T, class U>       struct is_nothrow_assignable;
-    template <class T>                struct is_nothrow_copy_assignable;
-    template <class T>                struct is_nothrow_move_assignable;
-    template <class T, class U>       struct is_nothrow_swappable_with; // C++17
-    template <class T>                struct is_nothrow_swappable;      // C++17
-    template <class T>                struct is_nothrow_destructible;
-
-    template <class T> struct has_virtual_destructor;
-
-    template<class T> struct has_unique_object_representations;         // C++17
-
-    // Relationships between types:
-    template <class T, class U> struct is_same;
-    template <class Base, class Derived> struct is_base_of;
-    template <class From, class To> struct is_convertible;
-
-    template <class Fn, class... ArgTypes> struct is_invocable;
-    template <class R, class Fn, class... ArgTypes> struct is_invocable_r;
-
-    template <class Fn, class... ArgTypes> struct is_nothrow_invocable;
-    template <class R, class Fn, class... ArgTypes> struct is_nothrow_invocable_r;
-
-    // Alignment properties and transformations:
-    template <class T> struct alignment_of;
-    template <size_t Len, size_t Align = most_stringent_alignment_requirement>
-        struct aligned_storage;
-    template <size_t Len, class... Types> struct aligned_union;
-    template <class T> struct remove_cvref; // C++20
-
-    template <class T> struct decay;
-    template <class... T> struct common_type;
-    template <class T> struct underlying_type;
-    template <class> class result_of; // undefined
-    template <class Fn, class... ArgTypes> class result_of<Fn(ArgTypes...)>;
-    template <class Fn, class... ArgTypes> struct invoke_result;  // C++17
-
-    // const-volatile modifications:
-    template <class T>
-      using remove_const_t    = typename remove_const<T>::type;  // C++14
-    template <class T>
-      using remove_volatile_t = typename remove_volatile<T>::type;  // C++14
-    template <class T>
-      using remove_cv_t       = typename remove_cv<T>::type;  // C++14
-    template <class T>
-      using add_const_t       = typename add_const<T>::type;  // C++14
-    template <class T>
-      using add_volatile_t    = typename add_volatile<T>::type;  // C++14
-    template <class T>
-      using add_cv_t          = typename add_cv<T>::type;  // C++14
-
-    // reference modifications:
-    template <class T>
-      using remove_reference_t     = typename remove_reference<T>::type;  // C++14
-    template <class T>
-      using add_lvalue_reference_t = typename add_lvalue_reference<T>::type;  // C++14
-    template <class T>
-      using add_rvalue_reference_t = typename add_rvalue_reference<T>::type;  // C++14
-
-    // sign modifications:
-    template <class T>
-      using make_signed_t   = typename make_signed<T>::type;  // C++14
-    template <class T>
-      using make_unsigned_t = typename make_unsigned<T>::type;  // C++14
-
-    // array modifications:
-    template <class T>
-      using remove_extent_t      = typename remove_extent<T>::type;  // C++14
-    template <class T>
-      using remove_all_extents_t = typename remove_all_extents<T>::type;  // C++14
-
-    // pointer modifications:
-    template <class T>
-      using remove_pointer_t = typename remove_pointer<T>::type;  // C++14
-    template <class T>
-      using add_pointer_t    = typename add_pointer<T>::type;  // C++14
-
-    // other transformations:
-    template <size_t Len, std::size_t Align=default-alignment>
-      using aligned_storage_t = typename aligned_storage<Len,Align>::type;  // C++14
-    template <std::size_t Len, class... Types>
-      using aligned_union_t   = typename aligned_union<Len,Types...>::type;  // C++14
-    template <class T>
-      using remove_cvref_t    = typename remove_cvref<T>::type;  // C++20
-    template <class T>
-      using decay_t           = typename decay<T>::type;  // C++14
-    template <bool b, class T=void>
-      using enable_if_t       = typename enable_if<b,T>::type;  // C++14
-    template <bool b, class T, class F>
-      using conditional_t     = typename conditional<b,T,F>::type;  // C++14
-    template <class... T>
-      using common_type_t     = typename common_type<T...>::type;  // C++14
-    template <class T>
-      using underlying_type_t = typename underlying_type<T>::type;  // C++14
-    template <class T>
-      using result_of_t       = typename result_of<T>::type;  // C++14
-    template <class Fn, class... ArgTypes>
-      using invoke_result_t   = typename invoke_result<Fn, ArgTypes...>::type;  // C++17
-
-    template <class...>
-      using void_t = void;   // C++17
-
-      // See C++14 20.10.4.1, primary type categories
-      template <class T> inline constexpr bool is_void_v
-        = is_void<T>::value;                                             // C++17
-      template <class T> inline constexpr bool is_null_pointer_v
-        = is_null_pointer<T>::value;                                     // C++17
-      template <class T> inline constexpr bool is_integral_v
-        = is_integral<T>::value;                                         // C++17
-      template <class T> inline constexpr bool is_floating_point_v
-        = is_floating_point<T>::value;                                   // C++17
-      template <class T> inline constexpr bool is_array_v
-        = is_array<T>::value;                                            // C++17
-      template <class T> inline constexpr bool is_pointer_v
-        = is_pointer<T>::value;                                          // C++17
-      template <class T> inline constexpr bool is_lvalue_reference_v
-        = is_lvalue_reference<T>::value;                                 // C++17
-      template <class T> inline constexpr bool is_rvalue_reference_v
-        = is_rvalue_reference<T>::value;                                 // C++17
-      template <class T> inline constexpr bool is_member_object_pointer_v
-        = is_member_object_pointer<T>::value;                            // C++17
-      template <class T> inline constexpr bool is_member_function_pointer_v
-        = is_member_function_pointer<T>::value;                          // C++17
-      template <class T> inline constexpr bool is_enum_v
-        = is_enum<T>::value;                                             // C++17
-      template <class T> inline constexpr bool is_union_v
-        = is_union<T>::value;                                            // C++17
-      template <class T> inline constexpr bool is_class_v
-        = is_class<T>::value;                                            // C++17
-      template <class T> inline constexpr bool is_function_v
-        = is_function<T>::value;                                         // C++17
-
-      // See C++14 20.10.4.2, composite type categories
-      template <class T> inline constexpr bool is_reference_v
-        = is_reference<T>::value;                                        // C++17
-      template <class T> inline constexpr bool is_arithmetic_v
-        = is_arithmetic<T>::value;                                       // C++17
-      template <class T> inline constexpr bool is_fundamental_v
-        = is_fundamental<T>::value;                                      // C++17
-      template <class T> inline constexpr bool is_object_v
-        = is_object<T>::value;                                           // C++17
-      template <class T> inline constexpr bool is_scalar_v
-        = is_scalar<T>::value;                                           // C++17
-      template <class T> inline constexpr bool is_compound_v
-        = is_compound<T>::value;                                         // C++17
-      template <class T> inline constexpr bool is_member_pointer_v
-        = is_member_pointer<T>::value;                                   // C++17
-
-      // See C++14 20.10.4.3, type properties
-      template <class T> inline constexpr bool is_const_v
-        = is_const<T>::value;                                            // C++17
-      template <class T> inline constexpr bool is_volatile_v
-        = is_volatile<T>::value;                                         // C++17
-      template <class T> inline constexpr bool is_trivial_v
-        = is_trivial<T>::value;                                          // C++17
-      template <class T> inline constexpr bool is_trivially_copyable_v
-        = is_trivially_copyable<T>::value;                               // C++17
-      template <class T> inline constexpr bool is_standard_layout_v
-        = is_standard_layout<T>::value;                                  // C++17
-      template <class T> inline constexpr bool is_pod_v
-        = is_pod<T>::value;                                              // C++17
-      template <class T> inline constexpr bool is_literal_type_v
-        = is_literal_type<T>::value;                                     // C++17
-      template <class T> inline constexpr bool is_empty_v
-        = is_empty<T>::value;                                            // C++17
-      template <class T> inline constexpr bool is_polymorphic_v
-        = is_polymorphic<T>::value;                                      // C++17
-      template <class T> inline constexpr bool is_abstract_v
-        = is_abstract<T>::value;                                         // C++17
-      template <class T> inline constexpr bool is_final_v
-        = is_final<T>::value;                                            // C++17
-      template <class T> inline constexpr bool is_aggregate_v
-        = is_aggregate<T>::value;                                        // C++17
-      template <class T> inline constexpr bool is_signed_v
-        = is_signed<T>::value;                                           // C++17
-      template <class T> inline constexpr bool is_unsigned_v
-        = is_unsigned<T>::value;                                         // C++17
-      template <class T, class... Args> inline constexpr bool is_constructible_v
-        = is_constructible<T, Args...>::value;                           // C++17
-      template <class T> inline constexpr bool is_default_constructible_v
-        = is_default_constructible<T>::value;                            // C++17
-      template <class T> inline constexpr bool is_copy_constructible_v
-        = is_copy_constructible<T>::value;                               // C++17
-      template <class T> inline constexpr bool is_move_constructible_v
-        = is_move_constructible<T>::value;                               // C++17
-      template <class T, class U> inline constexpr bool is_assignable_v
-        = is_assignable<T, U>::value;                                    // C++17
-      template <class T> inline constexpr bool is_copy_assignable_v
-        = is_copy_assignable<T>::value;                                  // C++17
-      template <class T> inline constexpr bool is_move_assignable_v
-        = is_move_assignable<T>::value;                                  // C++17
-      template <class T, class U> inline constexpr bool is_swappable_with_v
-        = is_swappable_with<T, U>::value;                                // C++17
-      template <class T> inline constexpr bool is_swappable_v
-        = is_swappable<T>::value;                                        // C++17
-      template <class T> inline constexpr bool is_destructible_v
-        = is_destructible<T>::value;                                     // C++17
-      template <class T, class... Args> inline constexpr bool is_trivially_constructible_v
-        = is_trivially_constructible<T, Args...>::value;                 // C++17
-      template <class T> inline constexpr bool is_trivially_default_constructible_v
-        = is_trivially_default_constructible<T>::value;                  // C++17
-      template <class T> inline constexpr bool is_trivially_copy_constructible_v
-        = is_trivially_copy_constructible<T>::value;                     // C++17
-      template <class T> inline constexpr bool is_trivially_move_constructible_v
-        = is_trivially_move_constructible<T>::value;                     // C++17
-      template <class T, class U> inline constexpr bool is_trivially_assignable_v
-        = is_trivially_assignable<T, U>::value;                          // C++17
-      template <class T> inline constexpr bool is_trivially_copy_assignable_v
-        = is_trivially_copy_assignable<T>::value;                        // C++17
-      template <class T> inline constexpr bool is_trivially_move_assignable_v
-        = is_trivially_move_assignable<T>::value;                        // C++17
-      template <class T> inline constexpr bool is_trivially_destructible_v
-        = is_trivially_destructible<T>::value;                           // C++17
-      template <class T, class... Args> inline constexpr bool is_nothrow_constructible_v
-        = is_nothrow_constructible<T, Args...>::value;                   // C++17
-      template <class T> inline constexpr bool is_nothrow_default_constructible_v
-        = is_nothrow_default_constructible<T>::value;                    // C++17
-      template <class T> inline constexpr bool is_nothrow_copy_constructible_v
-        = is_nothrow_copy_constructible<T>::value;                       // C++17
-      template <class T> inline constexpr bool is_nothrow_move_constructible_v
-        = is_nothrow_move_constructible<T>::value;                       // C++17
-      template <class T, class U> inline constexpr bool is_nothrow_assignable_v
-        = is_nothrow_assignable<T, U>::value;                            // C++17
-      template <class T> inline constexpr bool is_nothrow_copy_assignable_v
-        = is_nothrow_copy_assignable<T>::value;                          // C++17
-      template <class T> inline constexpr bool is_nothrow_move_assignable_v
-        = is_nothrow_move_assignable<T>::value;                          // C++17
-      template <class T, class U> inline constexpr bool is_nothrow_swappable_with_v
-        = is_nothrow_swappable_with<T, U>::value;                       // C++17
-      template <class T> inline constexpr bool is_nothrow_swappable_v
-        = is_nothrow_swappable<T>::value;                               // C++17
-      template <class T> inline constexpr bool is_nothrow_destructible_v
-        = is_nothrow_destructible<T>::value;                             // C++17
-      template <class T> inline constexpr bool has_virtual_destructor_v
-        = has_virtual_destructor<T>::value;                              // C++17
-      template<class T> inline constexpr bool has_unique_object_representations_v // C++17
-        = has_unique_object_representations<T>::value;
-
-      // See C++14 20.10.5, type property queries
-      template <class T> inline constexpr size_t alignment_of_v
-        = alignment_of<T>::value;                                        // C++17
-      template <class T> inline constexpr size_t rank_v
-        = rank<T>::value;                                                // C++17
-      template <class T, unsigned I = 0> inline constexpr size_t extent_v
-        = extent<T, I>::value;                                           // C++17
-
-      // See C++14 20.10.6, type relations
-      template <class T, class U> inline constexpr bool is_same_v
-        = is_same<T, U>::value;                                          // C++17
-      template <class Base, class Derived> inline constexpr bool is_base_of_v
-        = is_base_of<Base, Derived>::value;                              // C++17
-      template <class From, class To> inline constexpr bool is_convertible_v
-        = is_convertible<From, To>::value;                               // C++17
-      template <class Fn, class... ArgTypes> inline constexpr bool is_invocable_v
-        = is_invocable<Fn, ArgTypes...>::value;                          // C++17
-      template <class R, class Fn, class... ArgTypes> inline constexpr bool is_invocable_r_v
-        = is_invocable_r<R, Fn, ArgTypes...>::value;                     // C++17
-      template <class Fn, class... ArgTypes> inline constexpr bool is_nothrow_invocable_v
-        = is_nothrow_invocable<Fn, ArgTypes...>::value;                  // C++17
-      template <class R, class Fn, class... ArgTypes> inline constexpr bool is_nothrow_invocable_r_v
-        = is_nothrow_invocable_r<R, Fn, ArgTypes...>::value;             // C++17
-
-      // [meta.logical], logical operator traits:
-      template<class... B> struct conjunction;                           // C++17
-      template<class... B>
-        inline constexpr bool conjunction_v = conjunction<B...>::value;  // C++17
-      template<class... B> struct disjunction;                           // C++17
-      template<class... B>
-        inline constexpr bool disjunction_v = disjunction<B...>::value;  // C++17
-      template<class B> struct negation;                                 // C++17
-      template<class B>
-        inline constexpr bool negation_v = negation<B>::value;           // C++17
-
-}
-
-*/
-#include <__config>
-#include <cstddef>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _T1, class _T2> struct _LIBCPP_TEMPLATE_VIS pair;
-template <class _Tp> class _LIBCPP_TEMPLATE_VIS reference_wrapper;
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS hash;
-
-template <class>
-struct __void_t { typedef void type; };
-
-template <class _Tp>
-struct __identity { typedef _Tp type; };
-
-template <class _Tp, bool>
-struct _LIBCPP_TEMPLATE_VIS __dependent_type : public _Tp {};
-
-template <bool _Bp, class _If, class _Then>
-    struct _LIBCPP_TEMPLATE_VIS conditional {typedef _If type;};
-template <class _If, class _Then>
-    struct _LIBCPP_TEMPLATE_VIS conditional<false, _If, _Then> {typedef _Then type;};
-
-#if _LIBCPP_STD_VER > 11
-template <bool _Bp, class _If, class _Then> using conditional_t = typename conditional<_Bp, _If, _Then>::type;
-#endif
-
-template <bool, class _Tp> struct _LIBCPP_TEMPLATE_VIS __lazy_enable_if {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS __lazy_enable_if<true, _Tp> {typedef typename _Tp::type type;};
-
-template <bool, class _Tp = void> struct _LIBCPP_TEMPLATE_VIS enable_if {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS enable_if<true, _Tp> {typedef _Tp type;};
-
-#if _LIBCPP_STD_VER > 11
-template <bool _Bp, class _Tp = void> using enable_if_t = typename enable_if<_Bp, _Tp>::type;
-#endif
-
-// addressof
-#ifndef _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
-
-template <class _Tp>
-inline _LIBCPP_CONSTEXPR_AFTER_CXX14
-_LIBCPP_NO_CFI _LIBCPP_INLINE_VISIBILITY
-_Tp*
-addressof(_Tp& __x) _NOEXCEPT
-{
-    return __builtin_addressof(__x);
-}
-
-#else
-
-template <class _Tp>
-inline _LIBCPP_NO_CFI _LIBCPP_INLINE_VISIBILITY
-_Tp*
-addressof(_Tp& __x) _NOEXCEPT
-{
-  return reinterpret_cast<_Tp *>(
-      const_cast<char *>(&reinterpret_cast<const volatile char &>(__x)));
-}
-
-#endif // _LIBCPP_HAS_NO_BUILTIN_ADDRESSOF
-
-#if defined(_LIBCPP_HAS_OBJC_ARC) && !defined(_LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF)
-// Objective-C++ Automatic Reference Counting uses qualified pointers
-// that require special addressof() signatures. When
-// _LIBCPP_PREDEFINED_OBJC_ARC_ADDRESSOF is defined, the compiler
-// itself is providing these definitions. Otherwise, we provide them.
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__strong _Tp*
-addressof(__strong _Tp& __x) _NOEXCEPT
-{
-  return &__x;
-}
-
-#ifdef _LIBCPP_HAS_OBJC_ARC_WEAK
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__weak _Tp*
-addressof(__weak _Tp& __x) _NOEXCEPT
-{
-  return &__x;
-}
-#endif
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__autoreleasing _Tp*
-addressof(__autoreleasing _Tp& __x) _NOEXCEPT
-{
-  return &__x;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-__unsafe_unretained _Tp*
-addressof(__unsafe_unretained _Tp& __x) _NOEXCEPT
-{
-  return &__x;
-}
-#endif
-
-#if !defined(_LIBCPP_CXX03_LANG)
-template <class _Tp> _Tp* addressof(const _Tp&&) noexcept = delete;
-#endif
-
-struct __two {char __lx[2];};
-
-// helper class:
-
-template <class _Tp, _Tp __v>
-struct _LIBCPP_TEMPLATE_VIS integral_constant
-{
-    static _LIBCPP_CONSTEXPR const _Tp      value = __v;
-    typedef _Tp               value_type;
-    typedef integral_constant type;
-    _LIBCPP_INLINE_VISIBILITY
-        _LIBCPP_CONSTEXPR operator value_type() const _NOEXCEPT {return value;}
-#if _LIBCPP_STD_VER > 11
-    _LIBCPP_INLINE_VISIBILITY
-         constexpr value_type operator ()() const _NOEXCEPT {return value;}
-#endif
-};
-
-template <class _Tp, _Tp __v>
-_LIBCPP_CONSTEXPR const _Tp integral_constant<_Tp, __v>::value;
-
-#if _LIBCPP_STD_VER > 14
-template <bool __b>
-using bool_constant = integral_constant<bool, __b>;
-#define _LIBCPP_BOOL_CONSTANT(__b) bool_constant<(__b)>
-#else
-#define _LIBCPP_BOOL_CONSTANT(__b) integral_constant<bool,(__b)>
-#endif
-
-typedef _LIBCPP_BOOL_CONSTANT(true)  true_type;
-typedef _LIBCPP_BOOL_CONSTANT(false) false_type;
-
-#if !defined(_LIBCPP_CXX03_LANG)
-
-// __lazy_and
-
-template <bool _Last, class ..._Preds>
-struct __lazy_and_impl;
-
-template <class ..._Preds>
-struct __lazy_and_impl<false, _Preds...> : false_type {};
-
-template <>
-struct __lazy_and_impl<true> : true_type {};
-
-template <class _Pred>
-struct __lazy_and_impl<true, _Pred> : integral_constant<bool, _Pred::type::value> {};
-
-template <class _Hp, class ..._Tp>
-struct __lazy_and_impl<true, _Hp, _Tp...> : __lazy_and_impl<_Hp::type::value, _Tp...> {};
-
-template <class _P1, class ..._Pr>
-struct __lazy_and : __lazy_and_impl<_P1::type::value, _Pr...> {};
-
-// __lazy_or
-
-template <bool _List, class ..._Preds>
-struct __lazy_or_impl;
-
-template <class ..._Preds>
-struct __lazy_or_impl<true, _Preds...> : true_type {};
-
-template <>
-struct __lazy_or_impl<false> : false_type {};
-
-template <class _Hp, class ..._Tp>
-struct __lazy_or_impl<false, _Hp, _Tp...>
-        : __lazy_or_impl<_Hp::type::value, _Tp...> {};
-
-template <class _P1, class ..._Pr>
-struct __lazy_or : __lazy_or_impl<_P1::type::value, _Pr...> {};
-
-// __lazy_not
-
-template <class _Pred>
-struct __lazy_not : integral_constant<bool, !_Pred::type::value> {};
-
-// __and_
-template<class...> struct __and_;
-template<> struct __and_<> : true_type {};
-
-template<class _B0> struct __and_<_B0> : _B0 {};
-
-template<class _B0, class _B1>
-struct __and_<_B0, _B1> : conditional<_B0::value, _B1, _B0>::type {};
-
-template<class _B0, class _B1, class _B2, class... _Bn>
-struct __and_<_B0, _B1, _B2, _Bn...>
-        : conditional<_B0::value, __and_<_B1, _B2, _Bn...>, _B0>::type {};
-
-// __or_
-template<class...> struct __or_;
-template<> struct __or_<> : false_type {};
-
-template<class _B0> struct __or_<_B0> : _B0 {};
-
-template<class _B0, class _B1>
-struct __or_<_B0, _B1> : conditional<_B0::value, _B0, _B1>::type {};
-
-template<class _B0, class _B1, class _B2, class... _Bn>
-struct __or_<_B0, _B1, _B2, _Bn...>
-        : conditional<_B0::value, _B0, __or_<_B1, _B2, _Bn...> >::type {};
-
-// __not_
-template<class _Tp>
-struct __not_ : conditional<_Tp::value, false_type, true_type>::type {};
-
-#endif // !defined(_LIBCPP_CXX03_LANG)
-
-// is_const
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_const            : public false_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_const<_Tp const> : public true_type {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_const_v
-    = is_const<_Tp>::value;
-#endif
-
-// is_volatile
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_volatile               : public false_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_volatile<_Tp volatile> : public true_type {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_volatile_v
-    = is_volatile<_Tp>::value;
-#endif
-
-// remove_const
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_const            {typedef _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_const<const _Tp> {typedef _Tp type;};
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using remove_const_t = typename remove_const<_Tp>::type;
-#endif
-
-// remove_volatile
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_volatile               {typedef _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_volatile<volatile _Tp> {typedef _Tp type;};
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using remove_volatile_t = typename remove_volatile<_Tp>::type;
-#endif
-
-// remove_cv
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_cv
-{typedef typename remove_volatile<typename remove_const<_Tp>::type>::type type;};
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using remove_cv_t = typename remove_cv<_Tp>::type;
-#endif
-
-// is_void
-
-template <class _Tp> struct __libcpp_is_void       : public false_type {};
-template <>          struct __libcpp_is_void<void> : public true_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_void
-    : public __libcpp_is_void<typename remove_cv<_Tp>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_void_v
-    = is_void<_Tp>::value;
-#endif
-
-// __is_nullptr_t
-
-template <class _Tp> struct __is_nullptr_t_impl       : public false_type {};
-template <>          struct __is_nullptr_t_impl<nullptr_t> : public true_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS __is_nullptr_t
-    : public __is_nullptr_t_impl<typename remove_cv<_Tp>::type> {};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_null_pointer
-    : public __is_nullptr_t_impl<typename remove_cv<_Tp>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_null_pointer_v
-    = is_null_pointer<_Tp>::value;
-#endif
-#endif
-
-// is_integral
-
-template <class _Tp> struct __libcpp_is_integral                     : public false_type {};
-template <>          struct __libcpp_is_integral<bool>               : public true_type {};
-template <>          struct __libcpp_is_integral<char>               : public true_type {};
-template <>          struct __libcpp_is_integral<signed char>        : public true_type {};
-template <>          struct __libcpp_is_integral<unsigned char>      : public true_type {};
-template <>          struct __libcpp_is_integral<wchar_t>            : public true_type {};
-#ifndef _LIBCPP_NO_HAS_CHAR8_T
-template <>          struct __libcpp_is_integral<char8_t>            : public true_type {};
-#endif
-#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
-template <>          struct __libcpp_is_integral<char16_t>           : public true_type {};
-template <>          struct __libcpp_is_integral<char32_t>           : public true_type {};
-#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
-template <>          struct __libcpp_is_integral<short>              : public true_type {};
-template <>          struct __libcpp_is_integral<unsigned short>     : public true_type {};
-template <>          struct __libcpp_is_integral<int>                : public true_type {};
-template <>          struct __libcpp_is_integral<unsigned int>       : public true_type {};
-template <>          struct __libcpp_is_integral<long>               : public true_type {};
-template <>          struct __libcpp_is_integral<unsigned long>      : public true_type {};
-template <>          struct __libcpp_is_integral<long long>          : public true_type {};
-template <>          struct __libcpp_is_integral<unsigned long long> : public true_type {};
-#ifndef _LIBCPP_HAS_NO_INT128
-template <>          struct __libcpp_is_integral<__int128_t>         : public true_type {};
-template <>          struct __libcpp_is_integral<__uint128_t>        : public true_type {};
-#endif
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_integral
-    : public __libcpp_is_integral<typename remove_cv<_Tp>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_integral_v
-    = is_integral<_Tp>::value;
-#endif
-
-// is_floating_point
-
-template <class _Tp> struct __libcpp_is_floating_point              : public false_type {};
-template <>          struct __libcpp_is_floating_point<float>       : public true_type {};
-template <>          struct __libcpp_is_floating_point<double>      : public true_type {};
-template <>          struct __libcpp_is_floating_point<long double> : public true_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_floating_point
-    : public __libcpp_is_floating_point<typename remove_cv<_Tp>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_floating_point_v
-    = is_floating_point<_Tp>::value;
-#endif
-
-// is_array
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_array
-    : public false_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_array<_Tp[]>
-    : public true_type {};
-template <class _Tp, size_t _Np> struct _LIBCPP_TEMPLATE_VIS is_array<_Tp[_Np]>
-    : public true_type {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_array_v
-    = is_array<_Tp>::value;
-#endif
-
-// is_pointer
-
-template <class _Tp> struct __libcpp_is_pointer       : public false_type {};
-template <class _Tp> struct __libcpp_is_pointer<_Tp*> : public true_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_pointer
-    : public __libcpp_is_pointer<typename remove_cv<_Tp>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_pointer_v
-    = is_pointer<_Tp>::value;
-#endif
-
-// is_reference
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_lvalue_reference       : public false_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_lvalue_reference<_Tp&> : public true_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_rvalue_reference        : public false_type {};
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_rvalue_reference<_Tp&&> : public true_type {};
-#endif
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_reference        : public false_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_reference<_Tp&>  : public true_type {};
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_reference<_Tp&&> : public true_type {};
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_reference_v
-    = is_reference<_Tp>::value;
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_lvalue_reference_v
-    = is_lvalue_reference<_Tp>::value;
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_rvalue_reference_v
-    = is_rvalue_reference<_Tp>::value;
-#endif
-// is_union
-
-#if __has_feature(is_union) || (_GNUC_VER >= 403)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_union
-    : public integral_constant<bool, __is_union(_Tp)> {};
-
-#else
-
-template <class _Tp> struct __libcpp_union : public false_type {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_union
-    : public __libcpp_union<typename remove_cv<_Tp>::type> {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_union_v
-    = is_union<_Tp>::value;
-#endif
-
-// is_class
-
-#if __has_feature(is_class) || (_GNUC_VER >= 403)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_class
-    : public integral_constant<bool, __is_class(_Tp)> {};
-
-#else
-
-namespace __is_class_imp
-{
-template <class _Tp> char  __test(int _Tp::*);
-template <class _Tp> __two __test(...);
-}
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_class
-    : public integral_constant<bool, sizeof(__is_class_imp::__test<_Tp>(0)) == 1 && !is_union<_Tp>::value> {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_class_v
-    = is_class<_Tp>::value;
-#endif
-
-// is_same
-
-template <class _Tp, class _Up> struct _LIBCPP_TEMPLATE_VIS is_same           : public false_type {};
-template <class _Tp>            struct _LIBCPP_TEMPLATE_VIS is_same<_Tp, _Tp> : public true_type {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_same_v
-    = is_same<_Tp, _Up>::value;
-#endif
-
-// is_function
-
-namespace __libcpp_is_function_imp
-{
-struct __dummy_type {};
-template <class _Tp> char  __test(_Tp*);
-template <class _Tp> char __test(__dummy_type);
-template <class _Tp> __two __test(...);
-template <class _Tp> _Tp&  __source(int);
-template <class _Tp> __dummy_type __source(...);
-}
-
-template <class _Tp, bool = is_class<_Tp>::value ||
-                            is_union<_Tp>::value ||
-                            is_void<_Tp>::value  ||
-                            is_reference<_Tp>::value ||
-                            __is_nullptr_t<_Tp>::value >
-struct __libcpp_is_function
-    : public integral_constant<bool, sizeof(__libcpp_is_function_imp::__test<_Tp>(__libcpp_is_function_imp::__source<_Tp>(0))) == 1>
-    {};
-template <class _Tp> struct __libcpp_is_function<_Tp, true> : public false_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_function
-    : public __libcpp_is_function<_Tp> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_function_v
-    = is_function<_Tp>::value;
-#endif
-
-// is_member_function_pointer
-
-// template <class _Tp> struct            __libcpp_is_member_function_pointer             : public false_type {};
-// template <class _Tp, class _Up> struct __libcpp_is_member_function_pointer<_Tp _Up::*> : public is_function<_Tp> {};
-//
-
-template <class _MP, bool _IsMemberFunctionPtr, bool _IsMemberObjectPtr>
-struct __member_pointer_traits_imp
-{  // forward declaration; specializations later
-};
-
-
-template <class _Tp> struct __libcpp_is_member_function_pointer
-    : public false_type {};
-
-template <class _Ret, class _Class>
-struct __libcpp_is_member_function_pointer<_Ret _Class::*>
-    : public is_function<_Ret> {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_member_function_pointer
-    : public __libcpp_is_member_function_pointer<typename remove_cv<_Tp>::type>::type {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_member_function_pointer_v
-    = is_member_function_pointer<_Tp>::value;
-#endif
-
-// is_member_pointer
-
-template <class _Tp>            struct __libcpp_is_member_pointer             : public false_type {};
-template <class _Tp, class _Up> struct __libcpp_is_member_pointer<_Tp _Up::*> : public true_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_member_pointer
-    : public __libcpp_is_member_pointer<typename remove_cv<_Tp>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_member_pointer_v
-    = is_member_pointer<_Tp>::value;
-#endif
-
-// is_member_object_pointer
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_member_object_pointer
-    : public integral_constant<bool, is_member_pointer<_Tp>::value &&
-                                    !is_member_function_pointer<_Tp>::value> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_member_object_pointer_v
-    = is_member_object_pointer<_Tp>::value;
-#endif
-
-// is_enum
-
-#if __has_feature(is_enum) || (_GNUC_VER >= 403)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_enum
-    : public integral_constant<bool, __is_enum(_Tp)> {};
-
-#else
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_enum
-    : public integral_constant<bool, !is_void<_Tp>::value             &&
-                                     !is_integral<_Tp>::value         &&
-                                     !is_floating_point<_Tp>::value   &&
-                                     !is_array<_Tp>::value            &&
-                                     !is_pointer<_Tp>::value          &&
-                                     !is_reference<_Tp>::value        &&
-                                     !is_member_pointer<_Tp>::value   &&
-                                     !is_union<_Tp>::value            &&
-                                     !is_class<_Tp>::value            &&
-                                     !is_function<_Tp>::value         > {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_enum_v
-    = is_enum<_Tp>::value;
-#endif
-
-// is_arithmetic
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_arithmetic
-    : public integral_constant<bool, is_integral<_Tp>::value      ||
-                                     is_floating_point<_Tp>::value> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_arithmetic_v
-    = is_arithmetic<_Tp>::value;
-#endif
-
-// is_fundamental
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_fundamental
-    : public integral_constant<bool, is_void<_Tp>::value        ||
-                                     __is_nullptr_t<_Tp>::value ||
-                                     is_arithmetic<_Tp>::value> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_fundamental_v
-    = is_fundamental<_Tp>::value;
-#endif
-
-// is_scalar
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_scalar
-    : public integral_constant<bool, is_arithmetic<_Tp>::value     ||
-                                     is_member_pointer<_Tp>::value ||
-                                     is_pointer<_Tp>::value        ||
-                                     __is_nullptr_t<_Tp>::value    ||
-                                     is_enum<_Tp>::value           > {};
-
-template <> struct _LIBCPP_TEMPLATE_VIS is_scalar<nullptr_t> : public true_type {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_scalar_v
-    = is_scalar<_Tp>::value;
-#endif
-
-// is_object
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_object
-    : public integral_constant<bool, is_scalar<_Tp>::value ||
-                                     is_array<_Tp>::value  ||
-                                     is_union<_Tp>::value  ||
-                                     is_class<_Tp>::value  > {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_object_v
-    = is_object<_Tp>::value;
-#endif
-
-// is_compound
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_compound
-    : public integral_constant<bool, !is_fundamental<_Tp>::value> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_compound_v
-    = is_compound<_Tp>::value;
-#endif
-
-
-// __is_referenceable  [defns.referenceable]
-
-struct __is_referenceable_impl {
-    template <class _Tp> static _Tp& __test(int);
-    template <class _Tp> static __two __test(...);
-};
-
-template <class _Tp>
-struct __is_referenceable : integral_constant<bool,
-    !is_same<decltype(__is_referenceable_impl::__test<_Tp>(0)), __two>::value> {};
-
-
-// add_const
-
-template <class _Tp, bool = is_reference<_Tp>::value ||
-                            is_function<_Tp>::value  ||
-                            is_const<_Tp>::value     >
-struct __add_const             {typedef _Tp type;};
-
-template <class _Tp>
-struct __add_const<_Tp, false> {typedef const _Tp type;};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_const
-    {typedef typename __add_const<_Tp>::type type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using add_const_t = typename add_const<_Tp>::type;
-#endif
-
-// add_volatile
-
-template <class _Tp, bool = is_reference<_Tp>::value ||
-                            is_function<_Tp>::value  ||
-                            is_volatile<_Tp>::value  >
-struct __add_volatile             {typedef _Tp type;};
-
-template <class _Tp>
-struct __add_volatile<_Tp, false> {typedef volatile _Tp type;};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_volatile
-    {typedef typename __add_volatile<_Tp>::type type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using add_volatile_t = typename add_volatile<_Tp>::type;
-#endif
-
-// add_cv
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_cv
-    {typedef typename add_const<typename add_volatile<_Tp>::type>::type type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using add_cv_t = typename add_cv<_Tp>::type;
-#endif
-
-// remove_reference
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_reference        {typedef _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_reference<_Tp&>  {typedef _Tp type;};
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_reference<_Tp&&> {typedef _Tp type;};
-#endif
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using remove_reference_t = typename remove_reference<_Tp>::type;
-#endif
-
-// add_lvalue_reference
-
-template <class _Tp, bool = __is_referenceable<_Tp>::value> struct __add_lvalue_reference_impl            { typedef _Tp  type; };
-template <class _Tp                                       > struct __add_lvalue_reference_impl<_Tp, true> { typedef _Tp& type; };
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_lvalue_reference
-{typedef typename __add_lvalue_reference_impl<_Tp>::type type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using add_lvalue_reference_t = typename add_lvalue_reference<_Tp>::type;
-#endif
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp, bool = __is_referenceable<_Tp>::value> struct __add_rvalue_reference_impl            { typedef _Tp   type; };
-template <class _Tp                                       > struct __add_rvalue_reference_impl<_Tp, true> { typedef _Tp&& type; };
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_rvalue_reference
-{typedef typename __add_rvalue_reference_impl<_Tp>::type type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using add_rvalue_reference_t = typename add_rvalue_reference<_Tp>::type;
-#endif
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp> _Tp&& __declval(int);
-template <class _Tp> _Tp   __declval(long);
-
-template <class _Tp>
-decltype(_VSTD::__declval<_Tp>(0))
-declval() _NOEXCEPT;
-
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp>
-typename add_lvalue_reference<_Tp>::type
-declval();
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-// __uncvref
-
-template <class _Tp>
-struct __uncvref  {
-    typedef typename remove_cv<typename remove_reference<_Tp>::type>::type type;
-};
-
-template <class _Tp>
-struct __unconstref {
-    typedef typename remove_const<typename remove_reference<_Tp>::type>::type type;
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp>
-using __uncvref_t = typename __uncvref<_Tp>::type;
-#endif
-
-// __is_same_uncvref
-
-template <class _Tp, class _Up>
-struct __is_same_uncvref : is_same<typename __uncvref<_Tp>::type,
-                                   typename __uncvref<_Up>::type> {};
-
-#if _LIBCPP_STD_VER > 17
-// remove_cvref - same as __uncvref
-template <class _Tp>
-struct remove_cvref : public __uncvref<_Tp> {};
-
-template <class _Tp> using remove_cvref_t = typename remove_cvref<_Tp>::type;
-#endif
-
-
-struct __any
-{
-    __any(...);
-};
-
-// remove_pointer
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_pointer                      {typedef _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_pointer<_Tp*>                {typedef _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_pointer<_Tp* const>          {typedef _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_pointer<_Tp* volatile>       {typedef _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_pointer<_Tp* const volatile> {typedef _Tp type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using remove_pointer_t = typename remove_pointer<_Tp>::type;
-#endif
-
-// add_pointer
-
-template <class _Tp,
-        bool = __is_referenceable<_Tp>::value ||
-                is_same<typename remove_cv<_Tp>::type, void>::value>
-struct __add_pointer_impl
-    {typedef typename remove_reference<_Tp>::type* type;};
-template <class _Tp> struct __add_pointer_impl<_Tp, false>
-    {typedef _Tp type;};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS add_pointer
-    {typedef typename __add_pointer_impl<_Tp>::type type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using add_pointer_t = typename add_pointer<_Tp>::type;
-#endif
-
-// type_identity
-#if _LIBCPP_STD_VER > 17
-template<class _Tp> struct type_identity { typedef _Tp type; };
-template<class _Tp> using type_identity_t = typename type_identity<_Tp>::type;
-#endif
-
-// is_signed
-
-template <class _Tp, bool = is_integral<_Tp>::value>
-struct __libcpp_is_signed_impl : public _LIBCPP_BOOL_CONSTANT(_Tp(-1) < _Tp(0)) {};
-
-template <class _Tp>
-struct __libcpp_is_signed_impl<_Tp, false> : public true_type {};  // floating point
-
-template <class _Tp, bool = is_arithmetic<_Tp>::value>
-struct __libcpp_is_signed : public __libcpp_is_signed_impl<_Tp> {};
-
-template <class _Tp> struct __libcpp_is_signed<_Tp, false> : public false_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_signed : public __libcpp_is_signed<_Tp> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_signed_v
-    = is_signed<_Tp>::value;
-#endif
-
-// is_unsigned
-
-template <class _Tp, bool = is_integral<_Tp>::value>
-struct __libcpp_is_unsigned_impl : public _LIBCPP_BOOL_CONSTANT(_Tp(0) < _Tp(-1)) {};
-
-template <class _Tp>
-struct __libcpp_is_unsigned_impl<_Tp, false> : public false_type {};  // floating point
-
-template <class _Tp, bool = is_arithmetic<_Tp>::value>
-struct __libcpp_is_unsigned : public __libcpp_is_unsigned_impl<_Tp> {};
-
-template <class _Tp> struct __libcpp_is_unsigned<_Tp, false> : public false_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_unsigned : public __libcpp_is_unsigned<_Tp> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_unsigned_v
-    = is_unsigned<_Tp>::value;
-#endif
-
-// rank
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS rank
-    : public integral_constant<size_t, 0> {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS rank<_Tp[]>
-    : public integral_constant<size_t, rank<_Tp>::value + 1> {};
-template <class _Tp, size_t _Np> struct _LIBCPP_TEMPLATE_VIS rank<_Tp[_Np]>
-    : public integral_constant<size_t, rank<_Tp>::value + 1> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR size_t rank_v
-    = rank<_Tp>::value;
-#endif
-
-// extent
-
-template <class _Tp, unsigned _Ip = 0> struct _LIBCPP_TEMPLATE_VIS extent
-    : public integral_constant<size_t, 0> {};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS extent<_Tp[], 0>
-    : public integral_constant<size_t, 0> {};
-template <class _Tp, unsigned _Ip> struct _LIBCPP_TEMPLATE_VIS extent<_Tp[], _Ip>
-    : public integral_constant<size_t, extent<_Tp, _Ip-1>::value> {};
-template <class _Tp, size_t _Np> struct _LIBCPP_TEMPLATE_VIS extent<_Tp[_Np], 0>
-    : public integral_constant<size_t, _Np> {};
-template <class _Tp, size_t _Np, unsigned _Ip> struct _LIBCPP_TEMPLATE_VIS extent<_Tp[_Np], _Ip>
-    : public integral_constant<size_t, extent<_Tp, _Ip-1>::value> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp, unsigned _Ip = 0>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR size_t extent_v
-    = extent<_Tp, _Ip>::value;
-#endif
-
-// remove_extent
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_extent
-    {typedef _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_extent<_Tp[]>
-    {typedef _Tp type;};
-template <class _Tp, size_t _Np> struct _LIBCPP_TEMPLATE_VIS remove_extent<_Tp[_Np]>
-    {typedef _Tp type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using remove_extent_t = typename remove_extent<_Tp>::type;
-#endif
-
-// remove_all_extents
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_all_extents
-    {typedef _Tp type;};
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS remove_all_extents<_Tp[]>
-    {typedef typename remove_all_extents<_Tp>::type type;};
-template <class _Tp, size_t _Np> struct _LIBCPP_TEMPLATE_VIS remove_all_extents<_Tp[_Np]>
-    {typedef typename remove_all_extents<_Tp>::type type;};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using remove_all_extents_t = typename remove_all_extents<_Tp>::type;
-#endif
-
-// decay
-
-template <class _Up, bool>
-struct __decay {
-    typedef typename remove_cv<_Up>::type type;
-};
-
-template <class _Up>
-struct __decay<_Up, true> {
-public:
-    typedef typename conditional
-                     <
-                         is_array<_Up>::value,
-                         typename remove_extent<_Up>::type*,
-                         typename conditional
-                         <
-                              is_function<_Up>::value,
-                              typename add_pointer<_Up>::type,
-                              typename remove_cv<_Up>::type
-                         >::type
-                     >::type type;
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS decay
-{
-private:
-    typedef typename remove_reference<_Tp>::type _Up;
-public:
-    typedef typename __decay<_Up, __is_referenceable<_Up>::value>::type type;
-};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using decay_t = typename decay<_Tp>::type;
-#endif
-
-// is_abstract
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_abstract
-    : public integral_constant<bool, __is_abstract(_Tp)> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_abstract_v
-    = is_abstract<_Tp>::value;
-#endif
-
-// is_final
-
-#if defined(_LIBCPP_HAS_IS_FINAL)
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS
-__libcpp_is_final : public integral_constant<bool, __is_final(_Tp)> {};
-#else
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS
-__libcpp_is_final : public false_type {};
-#endif
-
-#if defined(_LIBCPP_HAS_IS_FINAL) && _LIBCPP_STD_VER > 11
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS
-is_final : public integral_constant<bool, __is_final(_Tp)> {};
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_final_v
-    = is_final<_Tp>::value;
-#endif
-
-// is_aggregate
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_IS_AGGREGATE)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS
-is_aggregate : public integral_constant<bool, __is_aggregate(_Tp)> {};
-
-#if !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr bool is_aggregate_v
-    = is_aggregate<_Tp>::value;
-#endif
-
-#endif // _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_IS_AGGREGATE)
-
-// is_base_of
-
-#ifdef _LIBCPP_HAS_IS_BASE_OF
-
-template <class _Bp, class _Dp>
-struct _LIBCPP_TEMPLATE_VIS is_base_of
-    : public integral_constant<bool, __is_base_of(_Bp, _Dp)> {};
-
-#else  // _LIBCPP_HAS_IS_BASE_OF
-
-namespace __is_base_of_imp
-{
-template <class _Tp>
-struct _Dst
-{
-    _Dst(const volatile _Tp &);
-};
-template <class _Tp>
-struct _Src
-{
-    operator const volatile _Tp &();
-    template <class _Up> operator const _Dst<_Up> &();
-};
-template <size_t> struct __one { typedef char type; };
-template <class _Bp, class _Dp> typename __one<sizeof(_Dst<_Bp>(declval<_Src<_Dp> >()))>::type __test(int);
-template <class _Bp, class _Dp> __two __test(...);
-}
-
-template <class _Bp, class _Dp>
-struct _LIBCPP_TEMPLATE_VIS is_base_of
-    : public integral_constant<bool, is_class<_Bp>::value &&
-                                     sizeof(__is_base_of_imp::__test<_Bp, _Dp>(0)) == 2> {};
-
-#endif  // _LIBCPP_HAS_IS_BASE_OF
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Bp, class _Dp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_base_of_v
-    = is_base_of<_Bp, _Dp>::value;
-#endif
-
-// is_convertible
-
-#if __has_feature(is_convertible_to) && !defined(_LIBCPP_USE_IS_CONVERTIBLE_FALLBACK)
-
-template <class _T1, class _T2> struct _LIBCPP_TEMPLATE_VIS is_convertible
-    : public integral_constant<bool, __is_convertible_to(_T1, _T2) &&
-                                     !is_abstract<_T2>::value> {};
-
-#else  // __has_feature(is_convertible_to)
-
-namespace __is_convertible_imp
-{
-template <class _Tp> void  __test_convert(_Tp);
-
-template <class _From, class _To, class = void>
-struct __is_convertible_test : public false_type {};
-
-template <class _From, class _To>
-struct __is_convertible_test<_From, _To,
-    decltype(_VSTD::__is_convertible_imp::__test_convert<_To>(_VSTD::declval<_From>()))> : public true_type
-{};
-
-template <class _Tp, bool _IsArray =    is_array<_Tp>::value,
-                     bool _IsFunction = is_function<_Tp>::value,
-                     bool _IsVoid =     is_void<_Tp>::value>
-                     struct __is_array_function_or_void                          {enum {value = 0};};
-template <class _Tp> struct __is_array_function_or_void<_Tp, true, false, false> {enum {value = 1};};
-template <class _Tp> struct __is_array_function_or_void<_Tp, false, true, false> {enum {value = 2};};
-template <class _Tp> struct __is_array_function_or_void<_Tp, false, false, true> {enum {value = 3};};
-}
-
-template <class _Tp,
-    unsigned = __is_convertible_imp::__is_array_function_or_void<typename remove_reference<_Tp>::type>::value>
-struct __is_convertible_check
-{
-    static const size_t __v = 0;
-};
-
-template <class _Tp>
-struct __is_convertible_check<_Tp, 0>
-{
-    static const size_t __v = sizeof(_Tp);
-};
-
-template <class _T1, class _T2,
-    unsigned _T1_is_array_function_or_void = __is_convertible_imp::__is_array_function_or_void<_T1>::value,
-    unsigned _T2_is_array_function_or_void = __is_convertible_imp::__is_array_function_or_void<_T2>::value>
-struct __is_convertible
-    : public integral_constant<bool,
-        __is_convertible_imp::__is_convertible_test<_T1, _T2>::value
-#if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
-         && !(!is_function<_T1>::value && !is_reference<_T1>::value && is_reference<_T2>::value
-              && (!is_const<typename remove_reference<_T2>::type>::value
-                  || is_volatile<typename remove_reference<_T2>::type>::value)
-                  && (is_same<typename remove_cv<_T1>::type,
-                              typename remove_cv<typename remove_reference<_T2>::type>::type>::value
-                      || is_base_of<typename remove_reference<_T2>::type, _T1>::value))
-#endif
-    >
-{};
-
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 0, 1> : public false_type {};
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 1, 1> : public false_type {};
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 2, 1> : public false_type {};
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 3, 1> : public false_type {};
-
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 0, 2> : public false_type {};
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 1, 2> : public false_type {};
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 2, 2> : public false_type {};
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 3, 2> : public false_type {};
-
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 0, 3> : public false_type {};
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 1, 3> : public false_type {};
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 2, 3> : public false_type {};
-template <class _T1, class _T2> struct __is_convertible<_T1, _T2, 3, 3> : public true_type {};
-
-template <class _T1, class _T2> struct _LIBCPP_TEMPLATE_VIS is_convertible
-    : public __is_convertible<_T1, _T2>
-{
-    static const size_t __complete_check1 = __is_convertible_check<_T1>::__v;
-    static const size_t __complete_check2 = __is_convertible_check<_T2>::__v;
-};
-
-#endif  // __has_feature(is_convertible_to)
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _From, class _To>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_convertible_v
-    = is_convertible<_From, _To>::value;
-#endif
-
-// is_empty
-
-#if __has_feature(is_empty) || (_GNUC_VER >= 407)
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_empty
-    : public integral_constant<bool, __is_empty(_Tp)> {};
-
-#else  // __has_feature(is_empty)
-
-template <class _Tp>
-struct __is_empty1
-    : public _Tp
-{
-    double __lx;
-};
-
-struct __is_empty2
-{
-    double __lx;
-};
-
-template <class _Tp, bool = is_class<_Tp>::value>
-struct __libcpp_empty : public integral_constant<bool, sizeof(__is_empty1<_Tp>) == sizeof(__is_empty2)> {};
-
-template <class _Tp> struct __libcpp_empty<_Tp, false> : public false_type {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_empty : public __libcpp_empty<_Tp> {};
-
-#endif  // __has_feature(is_empty)
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_empty_v
-    = is_empty<_Tp>::value;
-#endif
-
-// is_polymorphic
-
-#if __has_feature(is_polymorphic) || defined(_LIBCPP_COMPILER_MSVC)
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_polymorphic
-    : public integral_constant<bool, __is_polymorphic(_Tp)> {};
-
-#else
-
-template<typename _Tp> char &__is_polymorphic_impl(
-    typename enable_if<sizeof((_Tp*)dynamic_cast<const volatile void*>(declval<_Tp*>())) != 0,
-                       int>::type);
-template<typename _Tp> __two &__is_polymorphic_impl(...);
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_polymorphic
-    : public integral_constant<bool, sizeof(__is_polymorphic_impl<_Tp>(0)) == 1> {};
-
-#endif // __has_feature(is_polymorphic)
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_polymorphic_v
-    = is_polymorphic<_Tp>::value;
-#endif
-
-// has_virtual_destructor
-
-#if __has_feature(has_virtual_destructor) || (_GNUC_VER >= 403)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS has_virtual_destructor
-    : public integral_constant<bool, __has_virtual_destructor(_Tp)> {};
-
-#else
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS has_virtual_destructor
-    : public false_type {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool has_virtual_destructor_v
-    = has_virtual_destructor<_Tp>::value;
-#endif
-
-// has_unique_object_representations
-
-#if _LIBCPP_STD_VER > 14 && defined(_LIBCPP_HAS_UNIQUE_OBJECT_REPRESENTATIONS)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS has_unique_object_representations
-    : public integral_constant<bool,
-       __has_unique_object_representations(remove_cv_t<remove_all_extents_t<_Tp>>)> {};
-
-#if !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool has_unique_object_representations_v
-    = has_unique_object_representations<_Tp>::value;
-#endif
-
-#endif
-
-// alignment_of
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS alignment_of
-    : public integral_constant<size_t, _LIBCPP_ALIGNOF(_Tp)> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR size_t alignment_of_v
-    = alignment_of<_Tp>::value;
-#endif
-
-// aligned_storage
-
-template <class _Hp, class _Tp>
-struct __type_list
-{
-    typedef _Hp _Head;
-    typedef _Tp _Tail;
-};
-
-struct __nat
-{
-#ifndef _LIBCPP_CXX03_LANG
-    __nat() = delete;
-    __nat(const __nat&) = delete;
-    __nat& operator=(const __nat&) = delete;
-    ~__nat() = delete;
-#endif
-};
-
-template <class _Tp>
-struct __align_type
-{
-    static const size_t value = _LIBCPP_PREFERRED_ALIGNOF(_Tp);
-    typedef _Tp type;
-};
-
-struct __struct_double {long double __lx;};
-struct __struct_double4 {double __lx[4];};
-
-typedef
-    __type_list<__align_type<unsigned char>,
-    __type_list<__align_type<unsigned short>,
-    __type_list<__align_type<unsigned int>,
-    __type_list<__align_type<unsigned long>,
-    __type_list<__align_type<unsigned long long>,
-    __type_list<__align_type<double>,
-    __type_list<__align_type<long double>,
-    __type_list<__align_type<__struct_double>,
-    __type_list<__align_type<__struct_double4>,
-    __type_list<__align_type<int*>,
-    __nat
-    > > > > > > > > > > __all_types;
-
-template <class _TL, size_t _Align> struct __find_pod;
-
-template <class _Hp, size_t _Align>
-struct __find_pod<__type_list<_Hp, __nat>, _Align>
-{
-    typedef typename conditional<
-                             _Align == _Hp::value,
-                             typename _Hp::type,
-                             void
-                         >::type type;
-};
-
-template <class _Hp, class _Tp, size_t _Align>
-struct __find_pod<__type_list<_Hp, _Tp>, _Align>
-{
-    typedef typename conditional<
-                             _Align == _Hp::value,
-                             typename _Hp::type,
-                             typename __find_pod<_Tp, _Align>::type
-                         >::type type;
-};
-
-template <class _TL, size_t _Len> struct __find_max_align;
-
-template <class _Hp, size_t _Len>
-struct __find_max_align<__type_list<_Hp, __nat>, _Len> : public integral_constant<size_t, _Hp::value> {};
-
-template <size_t _Len, size_t _A1, size_t _A2>
-struct __select_align
-{
-private:
-    static const size_t __min = _A2 < _A1 ? _A2 : _A1;
-    static const size_t __max = _A1 < _A2 ? _A2 : _A1;
-public:
-    static const size_t value = _Len < __max ? __min : __max;
-};
-
-template <class _Hp, class _Tp, size_t _Len>
-struct __find_max_align<__type_list<_Hp, _Tp>, _Len>
-    : public integral_constant<size_t, __select_align<_Len, _Hp::value, __find_max_align<_Tp, _Len>::value>::value> {};
-
-template <size_t _Len, size_t _Align = __find_max_align<__all_types, _Len>::value>
-struct _LIBCPP_TEMPLATE_VIS aligned_storage
-{
-    typedef typename __find_pod<__all_types, _Align>::type _Aligner;
-    static_assert(!is_void<_Aligner>::value, "");
-    union type
-    {
-        _Aligner __align;
-        unsigned char __data[(_Len + _Align - 1)/_Align * _Align];
-    };
-};
-
-#if _LIBCPP_STD_VER > 11
-template <size_t _Len, size_t _Align = __find_max_align<__all_types, _Len>::value>
-    using aligned_storage_t = typename aligned_storage<_Len, _Align>::type;
-#endif
-
-#define _CREATE_ALIGNED_STORAGE_SPECIALIZATION(n) \
-template <size_t _Len>\
-struct _LIBCPP_TEMPLATE_VIS aligned_storage<_Len, n>\
-{\
-    struct _ALIGNAS(n) type\
-    {\
-        unsigned char __lx[(_Len + n - 1)/n * n];\
-    };\
-}
-
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x1);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x2);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x4);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x8);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x10);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x20);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x40);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x80);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x100);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x200);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x400);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x800);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x1000);
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x2000);
-// PE/COFF does not support alignment beyond 8192 (=0x2000)
-#if !defined(_LIBCPP_OBJECT_FORMAT_COFF)
-_CREATE_ALIGNED_STORAGE_SPECIALIZATION(0x4000);
-#endif // !defined(_LIBCPP_OBJECT_FORMAT_COFF)
-
-#undef _CREATE_ALIGNED_STORAGE_SPECIALIZATION
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-// aligned_union
-
-template <size_t _I0, size_t ..._In>
-struct __static_max;
-
-template <size_t _I0>
-struct __static_max<_I0>
-{
-    static const size_t value = _I0;
-};
-
-template <size_t _I0, size_t _I1, size_t ..._In>
-struct __static_max<_I0, _I1, _In...>
-{
-    static const size_t value = _I0 >= _I1 ? __static_max<_I0, _In...>::value :
-                                             __static_max<_I1, _In...>::value;
-};
-
-template <size_t _Len, class _Type0, class ..._Types>
-struct aligned_union
-{
-    static const size_t alignment_value = __static_max<_LIBCPP_PREFERRED_ALIGNOF(_Type0),
-                                                       _LIBCPP_PREFERRED_ALIGNOF(_Types)...>::value;
-    static const size_t __len = __static_max<_Len, sizeof(_Type0),
-                                             sizeof(_Types)...>::value;
-    typedef typename aligned_storage<__len, alignment_value>::type type;
-};
-
-#if _LIBCPP_STD_VER > 11
-template <size_t _Len, class ..._Types> using aligned_union_t = typename aligned_union<_Len, _Types...>::type;
-#endif
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Tp>
-struct __numeric_type
-{
-   static void __test(...);
-   static float __test(float);
-   static double __test(char);
-   static double __test(int);
-   static double __test(unsigned);
-   static double __test(long);
-   static double __test(unsigned long);
-   static double __test(long long);
-   static double __test(unsigned long long);
-   static double __test(double);
-   static long double __test(long double);
-
-   typedef decltype(__test(declval<_Tp>())) type;
-   static const bool value = !is_same<type, void>::value;
-};
-
-template <>
-struct __numeric_type<void>
-{
-   static const bool value = true;
-};
-
-// __promote
-
-template <class _A1, class _A2 = void, class _A3 = void,
-          bool = __numeric_type<_A1>::value &&
-                 __numeric_type<_A2>::value &&
-                 __numeric_type<_A3>::value>
-class __promote_imp
-{
-public:
-    static const bool value = false;
-};
-
-template <class _A1, class _A2, class _A3>
-class __promote_imp<_A1, _A2, _A3, true>
-{
-private:
-    typedef typename __promote_imp<_A1>::type __type1;
-    typedef typename __promote_imp<_A2>::type __type2;
-    typedef typename __promote_imp<_A3>::type __type3;
-public:
-    typedef decltype(__type1() + __type2() + __type3()) type;
-    static const bool value = true;
-};
-
-template <class _A1, class _A2>
-class __promote_imp<_A1, _A2, void, true>
-{
-private:
-    typedef typename __promote_imp<_A1>::type __type1;
-    typedef typename __promote_imp<_A2>::type __type2;
-public:
-    typedef decltype(__type1() + __type2()) type;
-    static const bool value = true;
-};
-
-template <class _A1>
-class __promote_imp<_A1, void, void, true>
-{
-public:
-    typedef typename __numeric_type<_A1>::type type;
-    static const bool value = true;
-};
-
-template <class _A1, class _A2 = void, class _A3 = void>
-class __promote : public __promote_imp<_A1, _A2, _A3> {};
-
-// make_signed / make_unsigned
-
-typedef
-    __type_list<signed char,
-    __type_list<signed short,
-    __type_list<signed int,
-    __type_list<signed long,
-    __type_list<signed long long,
-#ifndef _LIBCPP_HAS_NO_INT128
-    __type_list<__int128_t,
-#endif
-    __nat
-#ifndef _LIBCPP_HAS_NO_INT128
-    >
-#endif
-    > > > > > __signed_types;
-
-typedef
-    __type_list<unsigned char,
-    __type_list<unsigned short,
-    __type_list<unsigned int,
-    __type_list<unsigned long,
-    __type_list<unsigned long long,
-#ifndef _LIBCPP_HAS_NO_INT128
-    __type_list<__uint128_t,
-#endif
-    __nat
-#ifndef _LIBCPP_HAS_NO_INT128
-    >
-#endif
-    > > > > > __unsigned_types;
-
-template <class _TypeList, size_t _Size, bool = _Size <= sizeof(typename _TypeList::_Head)> struct __find_first;
-
-template <class _Hp, class _Tp, size_t _Size>
-struct __find_first<__type_list<_Hp, _Tp>, _Size, true>
-{
-    typedef _Hp type;
-};
-
-template <class _Hp, class _Tp, size_t _Size>
-struct __find_first<__type_list<_Hp, _Tp>, _Size, false>
-{
-    typedef typename __find_first<_Tp, _Size>::type type;
-};
-
-template <class _Tp, class _Up, bool = is_const<typename remove_reference<_Tp>::type>::value,
-                             bool = is_volatile<typename remove_reference<_Tp>::type>::value>
-struct __apply_cv
-{
-    typedef _Up type;
-};
-
-template <class _Tp, class _Up>
-struct __apply_cv<_Tp, _Up, true, false>
-{
-    typedef const _Up type;
-};
-
-template <class _Tp, class _Up>
-struct __apply_cv<_Tp, _Up, false, true>
-{
-    typedef volatile _Up type;
-};
-
-template <class _Tp, class _Up>
-struct __apply_cv<_Tp, _Up, true, true>
-{
-    typedef const volatile _Up type;
-};
-
-template <class _Tp, class _Up>
-struct __apply_cv<_Tp&, _Up, false, false>
-{
-    typedef _Up& type;
-};
-
-template <class _Tp, class _Up>
-struct __apply_cv<_Tp&, _Up, true, false>
-{
-    typedef const _Up& type;
-};
-
-template <class _Tp, class _Up>
-struct __apply_cv<_Tp&, _Up, false, true>
-{
-    typedef volatile _Up& type;
-};
-
-template <class _Tp, class _Up>
-struct __apply_cv<_Tp&, _Up, true, true>
-{
-    typedef const volatile _Up& type;
-};
-
-template <class _Tp, bool = is_integral<_Tp>::value || is_enum<_Tp>::value>
-struct __make_signed {};
-
-template <class _Tp>
-struct __make_signed<_Tp, true>
-{
-    typedef typename __find_first<__signed_types, sizeof(_Tp)>::type type;
-};
-
-template <> struct __make_signed<bool,               true> {};
-template <> struct __make_signed<  signed short,     true> {typedef short     type;};
-template <> struct __make_signed<unsigned short,     true> {typedef short     type;};
-template <> struct __make_signed<  signed int,       true> {typedef int       type;};
-template <> struct __make_signed<unsigned int,       true> {typedef int       type;};
-template <> struct __make_signed<  signed long,      true> {typedef long      type;};
-template <> struct __make_signed<unsigned long,      true> {typedef long      type;};
-template <> struct __make_signed<  signed long long, true> {typedef long long type;};
-template <> struct __make_signed<unsigned long long, true> {typedef long long type;};
-#ifndef _LIBCPP_HAS_NO_INT128
-template <> struct __make_signed<__int128_t,         true> {typedef __int128_t type;};
-template <> struct __make_signed<__uint128_t,        true> {typedef __int128_t type;};
-#endif
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS make_signed
-{
-    typedef typename __apply_cv<_Tp, typename __make_signed<typename remove_cv<_Tp>::type>::type>::type type;
-};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using make_signed_t = typename make_signed<_Tp>::type;
-#endif
-
-template <class _Tp, bool = is_integral<_Tp>::value || is_enum<_Tp>::value>
-struct __make_unsigned {};
-
-template <class _Tp>
-struct __make_unsigned<_Tp, true>
-{
-    typedef typename __find_first<__unsigned_types, sizeof(_Tp)>::type type;
-};
-
-template <> struct __make_unsigned<bool,               true> {};
-template <> struct __make_unsigned<  signed short,     true> {typedef unsigned short     type;};
-template <> struct __make_unsigned<unsigned short,     true> {typedef unsigned short     type;};
-template <> struct __make_unsigned<  signed int,       true> {typedef unsigned int       type;};
-template <> struct __make_unsigned<unsigned int,       true> {typedef unsigned int       type;};
-template <> struct __make_unsigned<  signed long,      true> {typedef unsigned long      type;};
-template <> struct __make_unsigned<unsigned long,      true> {typedef unsigned long      type;};
-template <> struct __make_unsigned<  signed long long, true> {typedef unsigned long long type;};
-template <> struct __make_unsigned<unsigned long long, true> {typedef unsigned long long type;};
-#ifndef _LIBCPP_HAS_NO_INT128
-template <> struct __make_unsigned<__int128_t,         true> {typedef __uint128_t        type;};
-template <> struct __make_unsigned<__uint128_t,        true> {typedef __uint128_t        type;};
-#endif
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS make_unsigned
-{
-    typedef typename __apply_cv<_Tp, typename __make_unsigned<typename remove_cv<_Tp>::type>::type>::type type;
-};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using make_unsigned_t = typename make_unsigned<_Tp>::type;
-#endif
-
-#ifdef _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Tp, class _Up = void, class _Vp = void>
-struct _LIBCPP_TEMPLATE_VIS common_type
-{
-public:
-    typedef typename common_type<typename common_type<_Tp, _Up>::type, _Vp>::type type;
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS common_type<void, void, void>
-{
-public:
-    typedef void type;
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS common_type<_Tp, void, void>
-{
-public:
-    typedef typename common_type<_Tp, _Tp>::type type;
-};
-
-template <class _Tp, class _Up>
-struct _LIBCPP_TEMPLATE_VIS common_type<_Tp, _Up, void>
-{
-    typedef typename decay<decltype(
-        true ? _VSTD::declval<_Tp>() : _VSTD::declval<_Up>()
-      )>::type type;
-};
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-// bullet 1 - sizeof...(Tp) == 0
-
-template <class ..._Tp>
-struct _LIBCPP_TEMPLATE_VIS common_type {};
-
-// bullet 2 - sizeof...(Tp) == 1
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS common_type<_Tp>
-    : public common_type<_Tp, _Tp> {};
-
-// bullet 3 - sizeof...(Tp) == 2
-
-template <class _Tp, class _Up, class = void>
-struct __common_type2_imp {};
-
-template <class _Tp, class _Up>
-struct __common_type2_imp<_Tp, _Up,
-    typename __void_t<decltype(
-        true ? _VSTD::declval<_Tp>() : _VSTD::declval<_Up>()
-    )>::type>
-{
-    typedef typename decay<decltype(
-        true ? _VSTD::declval<_Tp>() : _VSTD::declval<_Up>()
-    )>::type type;
-};
-
-template <class _Tp, class _Up,
-          class _DTp = typename decay<_Tp>::type,
-          class _DUp = typename decay<_Up>::type>
-using __common_type2 =
-  typename conditional<
-    is_same<_Tp, _DTp>::value && is_same<_Up, _DUp>::value,
-    __common_type2_imp<_Tp, _Up>,
-    common_type<_DTp, _DUp>
-  >::type;
-
-template <class _Tp, class _Up>
-struct _LIBCPP_TEMPLATE_VIS common_type<_Tp, _Up>
-    : __common_type2<_Tp, _Up> {};
-
-// bullet 4 - sizeof...(Tp) > 2
-
-template <class ...Tp> struct __common_types;
-
-template <class, class = void>
-struct __common_type_impl {};
-
-template <class _Tp, class _Up>
-struct __common_type_impl<
-    __common_types<_Tp, _Up>,
-    typename __void_t<typename common_type<_Tp, _Up>::type>::type>
-{
-  typedef typename common_type<_Tp, _Up>::type type;
-};
-
-template <class _Tp, class _Up, class ..._Vp>
-struct __common_type_impl<__common_types<_Tp, _Up, _Vp...>,
-    typename __void_t<typename common_type<_Tp, _Up>::type>::type>
-  : __common_type_impl<
-      __common_types<typename common_type<_Tp, _Up>::type, _Vp...> >
-{
-
-};
-
-template <class _Tp, class _Up, class ..._Vp>
-struct _LIBCPP_TEMPLATE_VIS common_type<_Tp, _Up, _Vp...>
-    : __common_type_impl<__common_types<_Tp, _Up, _Vp...> > {};
-
-#if _LIBCPP_STD_VER > 11
-template <class ..._Tp> using common_type_t = typename common_type<_Tp...>::type;
-#endif
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-// is_assignable
-
-template<typename, typename _Tp> struct __select_2nd { typedef _Tp type; };
-
-template <class _Tp, class _Arg>
-typename __select_2nd<decltype((_VSTD::declval<_Tp>() = _VSTD::declval<_Arg>())), true_type>::type
-__is_assignable_test(int);
-
-template <class, class>
-false_type __is_assignable_test(...);
-
-
-template <class _Tp, class _Arg, bool = is_void<_Tp>::value || is_void<_Arg>::value>
-struct __is_assignable_imp
-    : public decltype((_VSTD::__is_assignable_test<_Tp, _Arg>(0))) {};
-
-template <class _Tp, class _Arg>
-struct __is_assignable_imp<_Tp, _Arg, true>
-    : public false_type
-{
-};
-
-template <class _Tp, class _Arg>
-struct is_assignable
-    : public __is_assignable_imp<_Tp, _Arg> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp, class _Arg>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_assignable_v
-    = is_assignable<_Tp, _Arg>::value;
-#endif
-
-// is_copy_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_copy_assignable
-    : public is_assignable<typename add_lvalue_reference<_Tp>::type,
-                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_copy_assignable_v
-    = is_copy_assignable<_Tp>::value;
-#endif
-
-// is_move_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_move_assignable
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    : public is_assignable<typename add_lvalue_reference<_Tp>::type,
-                           typename add_rvalue_reference<_Tp>::type> {};
-#else
-    : public is_copy_assignable<_Tp> {};
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_move_assignable_v
-    = is_move_assignable<_Tp>::value;
-#endif
-
-// is_destructible
-
-//  if it's a reference, return true
-//  if it's a function, return false
-//  if it's   void,     return false
-//  if it's an array of unknown bound, return false
-//  Otherwise, return "std::declval<_Up&>().~_Up()" is well-formed
-//    where _Up is remove_all_extents<_Tp>::type
-
-template <class>
-struct __is_destructible_apply { typedef int type; };
-
-template <typename _Tp>
-struct __is_destructor_wellformed {
-    template <typename _Tp1>
-    static char  __test (
-        typename __is_destructible_apply<decltype(_VSTD::declval<_Tp1&>().~_Tp1())>::type
-    );
-
-    template <typename _Tp1>
-    static __two __test (...);
-
-    static const bool value = sizeof(__test<_Tp>(12)) == sizeof(char);
-};
-
-template <class _Tp, bool>
-struct __destructible_imp;
-
-template <class _Tp>
-struct __destructible_imp<_Tp, false>
-   : public _VSTD::integral_constant<bool,
-        __is_destructor_wellformed<typename _VSTD::remove_all_extents<_Tp>::type>::value> {};
-
-template <class _Tp>
-struct __destructible_imp<_Tp, true>
-    : public _VSTD::true_type {};
-
-template <class _Tp, bool>
-struct __destructible_false;
-
-template <class _Tp>
-struct __destructible_false<_Tp, false> : public __destructible_imp<_Tp, _VSTD::is_reference<_Tp>::value> {};
-
-template <class _Tp>
-struct __destructible_false<_Tp, true> : public _VSTD::false_type {};
-
-template <class _Tp>
-struct is_destructible
-    : public __destructible_false<_Tp, _VSTD::is_function<_Tp>::value> {};
-
-template <class _Tp>
-struct is_destructible<_Tp[]>
-    : public _VSTD::false_type {};
-
-template <>
-struct is_destructible<void>
-    : public _VSTD::false_type {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_destructible_v
-    = is_destructible<_Tp>::value;
-#endif
-
-// move
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename remove_reference<_Tp>::type&&
-move(_Tp&& __t) _NOEXCEPT
-{
-    typedef typename remove_reference<_Tp>::type _Up;
-    return static_cast<_Up&&>(__t);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-_Tp&&
-forward(typename remove_reference<_Tp>::type& __t) _NOEXCEPT
-{
-    return static_cast<_Tp&&>(__t);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-_Tp&&
-forward(typename remove_reference<_Tp>::type&& __t) _NOEXCEPT
-{
-    static_assert(!is_lvalue_reference<_Tp>::value,
-                  "can not forward an rvalue as an lvalue");
-    return static_cast<_Tp&&>(__t);
-}
-
-#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp&
-move(_Tp& __t)
-{
-    return __t;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-const _Tp&
-move(const _Tp& __t)
-{
-    return __t;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp&
-forward(typename remove_reference<_Tp>::type& __t) _NOEXCEPT
-{
-    return __t;
-}
-
-
-template <class _Tp>
-class __rv
-{
-    typedef typename remove_reference<_Tp>::type _Trr;
-    _Trr& t_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    _Trr* operator->() {return &t_;}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __rv(_Trr& __t) : t_(__t) {}
-};
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename decay<_Tp>::type
-__decay_copy(_Tp&& __t)
-{
-    return _VSTD::forward<_Tp>(__t);
-}
-
-#else
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-typename decay<_Tp>::type
-__decay_copy(const _Tp& __t)
-{
-    return _VSTD::forward<_Tp>(__t);
-}
-
-#endif
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-#if __has_feature(cxx_reference_qualified_functions) || \
-    (defined(_GNUC_VER) && _GNUC_VER >= 409)
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) &, true, false>
-{
-    typedef _Class& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) &, true, false>
-{
-    typedef _Class& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const&, true, false>
-{
-    typedef _Class const& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const&, true, false>
-{
-    typedef _Class const& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) volatile&, true, false>
-{
-    typedef _Class volatile& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) volatile&, true, false>
-{
-    typedef _Class volatile& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const volatile&, true, false>
-{
-    typedef _Class const volatile& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const volatile&, true, false>
-{
-    typedef _Class const volatile& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) &&, true, false>
-{
-    typedef _Class&& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) &&, true, false>
-{
-    typedef _Class&& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const&&, true, false>
-{
-    typedef _Class const&& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const&&, true, false>
-{
-    typedef _Class const&& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) volatile&&, true, false>
-{
-    typedef _Class volatile&& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) volatile&&, true, false>
-{
-    typedef _Class volatile&& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param...) const volatile&&, true, false>
-{
-    typedef _Class const volatile&& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param...);
-};
-
-template <class _Rp, class _Class, class ..._Param>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_Param..., ...) const volatile&&, true, false>
-{
-    typedef _Class const volatile&& _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_Param..., ...);
-};
-
-#endif  // __has_feature(cxx_reference_qualified_functions) || _GNUC_VER >= 409
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Rp, class _Class>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) ();
-};
-
-template <class _Rp, class _Class>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(...), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (...);
-};
-
-template <class _Rp, class _Class, class _P0>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0);
-};
-
-template <class _Rp, class _Class, class _P0>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, ...), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, ...);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, ...), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, ...);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1, class _P2>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, _P2);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1, class _P2>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2, ...), true, false>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, _P2, ...);
-};
-
-template <class _Rp, class _Class>
-struct __member_pointer_traits_imp<_Rp (_Class::*)() const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) ();
-};
-
-template <class _Rp, class _Class>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(...) const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (...);
-};
-
-template <class _Rp, class _Class, class _P0>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0) const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0);
-};
-
-template <class _Rp, class _Class, class _P0>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, ...) const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, ...);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1) const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, ...) const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, ...);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1, class _P2>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2) const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, _P2);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1, class _P2>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2, ...) const, true, false>
-{
-    typedef _Class const _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, _P2, ...);
-};
-
-template <class _Rp, class _Class>
-struct __member_pointer_traits_imp<_Rp (_Class::*)() volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) ();
-};
-
-template <class _Rp, class _Class>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(...) volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (...);
-};
-
-template <class _Rp, class _Class, class _P0>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0) volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0);
-};
-
-template <class _Rp, class _Class, class _P0>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, ...) volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, ...);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1) volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, ...) volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, ...);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1, class _P2>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2) volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, _P2);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1, class _P2>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2, ...) volatile, true, false>
-{
-    typedef _Class volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, _P2, ...);
-};
-
-template <class _Rp, class _Class>
-struct __member_pointer_traits_imp<_Rp (_Class::*)() const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) ();
-};
-
-template <class _Rp, class _Class>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(...) const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (...);
-};
-
-template <class _Rp, class _Class, class _P0>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0) const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0);
-};
-
-template <class _Rp, class _Class, class _P0>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, ...) const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, ...);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1) const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, ...) const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, ...);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1, class _P2>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2) const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, _P2);
-};
-
-template <class _Rp, class _Class, class _P0, class _P1, class _P2>
-struct __member_pointer_traits_imp<_Rp (_Class::*)(_P0, _P1, _P2, ...) const volatile, true, false>
-{
-    typedef _Class const volatile _ClassType;
-    typedef _Rp _ReturnType;
-    typedef _Rp (_FnType) (_P0, _P1, _P2, ...);
-};
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Rp, class _Class>
-struct __member_pointer_traits_imp<_Rp _Class::*, false, true>
-{
-    typedef _Class _ClassType;
-    typedef _Rp _ReturnType;
-};
-
-template <class _MP>
-struct __member_pointer_traits
-    : public __member_pointer_traits_imp<typename remove_cv<_MP>::type,
-                    is_member_function_pointer<_MP>::value,
-                    is_member_object_pointer<_MP>::value>
-{
-//     typedef ... _ClassType;
-//     typedef ... _ReturnType;
-//     typedef ... _FnType;
-};
-
-
-template <class _DecayedFp>
-struct __member_pointer_class_type {};
-
-template <class _Ret, class _ClassType>
-struct __member_pointer_class_type<_Ret _ClassType::*> {
-  typedef _ClassType type;
-};
-
-// result_of
-
-template <class _Callable> class result_of;
-
-#ifdef _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Fn, bool, bool>
-class __result_of
-{
-};
-
-template <class _Fn>
-class __result_of<_Fn(), true, false>
-{
-public:
-    typedef decltype(declval<_Fn>()()) type;
-};
-
-template <class _Fn, class _A0>
-class __result_of<_Fn(_A0), true, false>
-{
-public:
-    typedef decltype(declval<_Fn>()(declval<_A0>())) type;
-};
-
-template <class _Fn, class _A0, class _A1>
-class __result_of<_Fn(_A0, _A1), true, false>
-{
-public:
-    typedef decltype(declval<_Fn>()(declval<_A0>(), declval<_A1>())) type;
-};
-
-template <class _Fn, class _A0, class _A1, class _A2>
-class __result_of<_Fn(_A0, _A1, _A2), true, false>
-{
-public:
-    typedef decltype(declval<_Fn>()(declval<_A0>(), declval<_A1>(), declval<_A2>())) type;
-};
-
-template <class _MP, class _Tp, bool _IsMemberFunctionPtr>
-struct __result_of_mp;
-
-// member function pointer
-
-template <class _MP, class _Tp>
-struct __result_of_mp<_MP, _Tp, true>
-    : public __identity<typename __member_pointer_traits<_MP>::_ReturnType>
-{
-};
-
-// member data pointer
-
-template <class _MP, class _Tp, bool>
-struct __result_of_mdp;
-
-template <class _Rp, class _Class, class _Tp>
-struct __result_of_mdp<_Rp _Class::*, _Tp, false>
-{
-    typedef typename __apply_cv<decltype(*_VSTD::declval<_Tp>()), _Rp>::type& type;
-};
-
-template <class _Rp, class _Class, class _Tp>
-struct __result_of_mdp<_Rp _Class::*, _Tp, true>
-{
-    typedef typename __apply_cv<_Tp, _Rp>::type& type;
-};
-
-template <class _Rp, class _Class, class _Tp>
-struct __result_of_mp<_Rp _Class::*, _Tp, false>
-    : public __result_of_mdp<_Rp _Class::*, _Tp,
-            is_base_of<_Class, typename remove_reference<_Tp>::type>::value>
-{
-};
-
-
-
-template <class _Fn, class _Tp>
-class __result_of<_Fn(_Tp), false, true>  // _Fn must be member pointer
-    : public __result_of_mp<typename remove_reference<_Fn>::type,
-                            _Tp,
-                            is_member_function_pointer<typename remove_reference<_Fn>::type>::value>
-{
-};
-
-template <class _Fn, class _Tp, class _A0>
-class __result_of<_Fn(_Tp, _A0), false, true>  // _Fn must be member pointer
-    : public __result_of_mp<typename remove_reference<_Fn>::type,
-                            _Tp,
-                            is_member_function_pointer<typename remove_reference<_Fn>::type>::value>
-{
-};
-
-template <class _Fn, class _Tp, class _A0, class _A1>
-class __result_of<_Fn(_Tp, _A0, _A1), false, true>  // _Fn must be member pointer
-    : public __result_of_mp<typename remove_reference<_Fn>::type,
-                            _Tp,
-                            is_member_function_pointer<typename remove_reference<_Fn>::type>::value>
-{
-};
-
-template <class _Fn, class _Tp, class _A0, class _A1, class _A2>
-class __result_of<_Fn(_Tp, _A0, _A1, _A2), false, true>  // _Fn must be member pointer
-    : public __result_of_mp<typename remove_reference<_Fn>::type,
-                            _Tp,
-                            is_member_function_pointer<typename remove_reference<_Fn>::type>::value>
-{
-};
-
-// result_of
-
-template <class _Fn>
-class _LIBCPP_TEMPLATE_VIS result_of<_Fn()>
-    : public __result_of<_Fn(),
-                         is_class<typename remove_reference<_Fn>::type>::value ||
-                         is_function<typename remove_pointer<typename remove_reference<_Fn>::type>::type>::value,
-                         is_member_pointer<typename remove_reference<_Fn>::type>::value
-                        >
-{
-};
-
-template <class _Fn, class _A0>
-class _LIBCPP_TEMPLATE_VIS result_of<_Fn(_A0)>
-    : public __result_of<_Fn(_A0),
-                         is_class<typename remove_reference<_Fn>::type>::value ||
-                         is_function<typename remove_pointer<typename remove_reference<_Fn>::type>::type>::value,
-                         is_member_pointer<typename remove_reference<_Fn>::type>::value
-                        >
-{
-};
-
-template <class _Fn, class _A0, class _A1>
-class _LIBCPP_TEMPLATE_VIS result_of<_Fn(_A0, _A1)>
-    : public __result_of<_Fn(_A0, _A1),
-                         is_class<typename remove_reference<_Fn>::type>::value ||
-                         is_function<typename remove_pointer<typename remove_reference<_Fn>::type>::type>::value,
-                         is_member_pointer<typename remove_reference<_Fn>::type>::value
-                        >
-{
-};
-
-template <class _Fn, class _A0, class _A1, class _A2>
-class _LIBCPP_TEMPLATE_VIS result_of<_Fn(_A0, _A1, _A2)>
-    : public __result_of<_Fn(_A0, _A1, _A2),
-                         is_class<typename remove_reference<_Fn>::type>::value ||
-                         is_function<typename remove_pointer<typename remove_reference<_Fn>::type>::type>::value,
-                         is_member_pointer<typename remove_reference<_Fn>::type>::value
-                        >
-{
-};
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-// template <class T, class... Args> struct is_constructible;
-
-namespace __is_construct
-{
-struct __nat {};
-}
-
-#if !defined(_LIBCPP_CXX03_LANG) && (!__has_feature(is_constructible) || \
-    defined(_LIBCPP_TESTING_FALLBACK_IS_CONSTRUCTIBLE))
-
-template <class _Tp, class... _Args>
-struct __libcpp_is_constructible;
-
-template <class _To, class _From>
-struct __is_invalid_base_to_derived_cast {
-  static_assert(is_reference<_To>::value, "Wrong specialization");
-  using _RawFrom = __uncvref_t<_From>;
-  using _RawTo = __uncvref_t<_To>;
-  static const bool value = __lazy_and<
-        __lazy_not<is_same<_RawFrom, _RawTo>>,
-        is_base_of<_RawFrom, _RawTo>,
-        __lazy_not<__libcpp_is_constructible<_RawTo, _From>>
-  >::value;
-};
-
-template <class _To, class _From>
-struct __is_invalid_lvalue_to_rvalue_cast : false_type {
-  static_assert(is_reference<_To>::value, "Wrong specialization");
-};
-
-template <class _ToRef, class _FromRef>
-struct __is_invalid_lvalue_to_rvalue_cast<_ToRef&&, _FromRef&> {
-  using _RawFrom = __uncvref_t<_FromRef>;
-  using _RawTo = __uncvref_t<_ToRef>;
-  static const bool value = __lazy_and<
-      __lazy_not<is_function<_RawTo>>,
-      __lazy_or<
-        is_same<_RawFrom, _RawTo>,
-        is_base_of<_RawTo, _RawFrom>>
-    >::value;
-};
-
-struct __is_constructible_helper
-{
-    template <class _To>
-    static void __eat(_To);
-
-    // This overload is needed to work around a Clang bug that disallows
-    // static_cast<T&&>(e) for non-reference-compatible types.
-    // Example: static_cast<int&&>(declval<double>());
-    // NOTE: The static_cast implementation below is required to support
-    //  classes with explicit conversion operators.
-    template <class _To, class _From,
-              class = decltype(__eat<_To>(_VSTD::declval<_From>()))>
-    static true_type __test_cast(int);
-
-    template <class _To, class _From,
-              class = decltype(static_cast<_To>(_VSTD::declval<_From>()))>
-    static integral_constant<bool,
-        !__is_invalid_base_to_derived_cast<_To, _From>::value &&
-        !__is_invalid_lvalue_to_rvalue_cast<_To, _From>::value
-    > __test_cast(long);
-
-    template <class, class>
-    static false_type __test_cast(...);
-
-    template <class _Tp, class ..._Args,
-        class = decltype(_Tp(_VSTD::declval<_Args>()...))>
-    static true_type __test_nary(int);
-    template <class _Tp, class...>
-    static false_type __test_nary(...);
-
-    template <class _Tp, class _A0, class = decltype(::new _Tp(_VSTD::declval<_A0>()))>
-    static is_destructible<_Tp> __test_unary(int);
-    template <class, class>
-    static false_type __test_unary(...);
-};
-
-template <class _Tp, bool = is_void<_Tp>::value>
-struct __is_default_constructible
-    : decltype(__is_constructible_helper::__test_nary<_Tp>(0))
-{};
-
-template <class _Tp>
-struct __is_default_constructible<_Tp, true> : false_type {};
-
-template <class _Tp>
-struct __is_default_constructible<_Tp[], false> : false_type {};
-
-template <class _Tp, size_t _Nx>
-struct __is_default_constructible<_Tp[_Nx], false>
-    : __is_default_constructible<typename remove_all_extents<_Tp>::type>  {};
-
-template <class _Tp, class... _Args>
-struct __libcpp_is_constructible
-{
-  static_assert(sizeof...(_Args) > 1, "Wrong specialization");
-  typedef decltype(__is_constructible_helper::__test_nary<_Tp, _Args...>(0))
-      type;
-};
-
-template <class _Tp>
-struct __libcpp_is_constructible<_Tp> : __is_default_constructible<_Tp> {};
-
-template <class _Tp, class _A0>
-struct __libcpp_is_constructible<_Tp, _A0>
-    : public decltype(__is_constructible_helper::__test_unary<_Tp, _A0>(0))
-{};
-
-template <class _Tp, class _A0>
-struct __libcpp_is_constructible<_Tp&, _A0>
-    : public decltype(__is_constructible_helper::
-    __test_cast<_Tp&, _A0>(0))
-{};
-
-template <class _Tp, class _A0>
-struct __libcpp_is_constructible<_Tp&&, _A0>
-    : public decltype(__is_constructible_helper::
-    __test_cast<_Tp&&, _A0>(0))
-{};
-
-#endif
-
-#if __has_feature(is_constructible)
-template <class _Tp, class ..._Args>
-struct _LIBCPP_TEMPLATE_VIS is_constructible
-    : public integral_constant<bool, __is_constructible(_Tp, _Args...)>
-    {};
-#elif !defined(_LIBCPP_CXX03_LANG)
-template <class _Tp, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS is_constructible
-    : public __libcpp_is_constructible<_Tp, _Args...>::type {};
-#else
-// template <class T> struct is_constructible0;
-
-//      main is_constructible0 test
-
-template <class _Tp>
-decltype((_Tp(), true_type()))
-__is_constructible0_test(_Tp&);
-
-false_type
-__is_constructible0_test(__any);
-
-template <class _Tp, class _A0>
-decltype((_Tp(_VSTD::declval<_A0>()), true_type()))
-__is_constructible1_test(_Tp&, _A0&);
-
-template <class _A0>
-false_type
-__is_constructible1_test(__any, _A0&);
-
-template <class _Tp, class _A0, class _A1>
-decltype((_Tp(_VSTD::declval<_A0>(), _VSTD::declval<_A1>()), true_type()))
-__is_constructible2_test(_Tp&, _A0&, _A1&);
-
-template <class _A0, class _A1>
-false_type
-__is_constructible2_test(__any, _A0&, _A1&);
-
-template <class _Tp, class _A0, class _A1, class _A2>
-decltype((_Tp(_VSTD::declval<_A0>(), _VSTD::declval<_A1>(), _VSTD::declval<_A2>()), true_type()))
-__is_constructible3_test(_Tp&, _A0&, _A1&, _A2&);
-
-template <class _A0, class _A1, class _A2>
-false_type
-__is_constructible3_test(__any, _A0&, _A1&, _A2&);
-
-template <bool, class _Tp>
-struct __is_constructible0_imp // false, _Tp is not a scalar
-    : public common_type
-             <
-                 decltype(__is_constructible0_test(declval<_Tp&>()))
-             >::type
-    {};
-
-template <bool, class _Tp, class _A0>
-struct __is_constructible1_imp // false, _Tp is not a scalar
-    : public common_type
-             <
-                 decltype(__is_constructible1_test(declval<_Tp&>(), declval<_A0&>()))
-             >::type
-    {};
-
-template <bool, class _Tp, class _A0, class _A1>
-struct __is_constructible2_imp // false, _Tp is not a scalar
-    : public common_type
-             <
-                 decltype(__is_constructible2_test(declval<_Tp&>(), declval<_A0>(), declval<_A1>()))
-             >::type
-    {};
-
-template <bool, class _Tp, class _A0, class _A1, class _A2>
-struct __is_constructible3_imp // false, _Tp is not a scalar
-    : public common_type
-             <
-                 decltype(__is_constructible3_test(declval<_Tp&>(), declval<_A0>(), declval<_A1>(), declval<_A2>()))
-             >::type
-    {};
-
-//      handle scalars and reference types
-
-//      Scalars are default constructible, references are not
-
-template <class _Tp>
-struct __is_constructible0_imp<true, _Tp>
-    : public is_scalar<_Tp>
-    {};
-
-template <class _Tp, class _A0>
-struct __is_constructible1_imp<true, _Tp, _A0>
-    : public is_convertible<_A0, _Tp>
-    {};
-
-template <class _Tp, class _A0, class _A1>
-struct __is_constructible2_imp<true, _Tp, _A0, _A1>
-    : public false_type
-    {};
-
-template <class _Tp, class _A0, class _A1, class _A2>
-struct __is_constructible3_imp<true, _Tp, _A0, _A1, _A2>
-    : public false_type
-    {};
-
-//      Treat scalars and reference types separately
-
-template <bool, class _Tp>
-struct __is_constructible0_void_check
-    : public __is_constructible0_imp<is_scalar<_Tp>::value || is_reference<_Tp>::value,
-                                _Tp>
-    {};
-
-template <bool, class _Tp, class _A0>
-struct __is_constructible1_void_check
-    : public __is_constructible1_imp<is_scalar<_Tp>::value || is_reference<_Tp>::value,
-                                _Tp, _A0>
-    {};
-
-template <bool, class _Tp, class _A0, class _A1>
-struct __is_constructible2_void_check
-    : public __is_constructible2_imp<is_scalar<_Tp>::value || is_reference<_Tp>::value,
-                                _Tp, _A0, _A1>
-    {};
-
-template <bool, class _Tp, class _A0, class _A1, class _A2>
-struct __is_constructible3_void_check
-    : public __is_constructible3_imp<is_scalar<_Tp>::value || is_reference<_Tp>::value,
-                                _Tp, _A0, _A1, _A2>
-    {};
-
-//      If any of T or Args is void, is_constructible should be false
-
-template <class _Tp>
-struct __is_constructible0_void_check<true, _Tp>
-    : public false_type
-    {};
-
-template <class _Tp, class _A0>
-struct __is_constructible1_void_check<true, _Tp, _A0>
-    : public false_type
-    {};
-
-template <class _Tp, class _A0, class _A1>
-struct __is_constructible2_void_check<true, _Tp, _A0, _A1>
-    : public false_type
-    {};
-
-template <class _Tp, class _A0, class _A1, class _A2>
-struct __is_constructible3_void_check<true, _Tp, _A0, _A1, _A2>
-    : public false_type
-    {};
-
-//      is_constructible entry point
-
-template <class _Tp, class _A0 = __is_construct::__nat,
-                     class _A1 = __is_construct::__nat,
-                     class _A2 = __is_construct::__nat>
-struct _LIBCPP_TEMPLATE_VIS is_constructible
-    : public __is_constructible3_void_check<is_void<_Tp>::value
-                                        || is_abstract<_Tp>::value
-                                        || is_function<_Tp>::value
-                                        || is_void<_A0>::value
-                                        || is_void<_A1>::value
-                                        || is_void<_A2>::value,
-                                           _Tp, _A0, _A1, _A2>
-    {};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_constructible<_Tp, __is_construct::__nat, __is_construct::__nat>
-    : public __is_constructible0_void_check<is_void<_Tp>::value
-                                        || is_abstract<_Tp>::value
-                                        || is_function<_Tp>::value,
-                                           _Tp>
-    {};
-
-template <class _Tp, class _A0>
-struct _LIBCPP_TEMPLATE_VIS is_constructible<_Tp, _A0, __is_construct::__nat>
-    : public __is_constructible1_void_check<is_void<_Tp>::value
-                                        || is_abstract<_Tp>::value
-                                        || is_function<_Tp>::value
-                                        || is_void<_A0>::value,
-                                           _Tp, _A0>
-    {};
-
-template <class _Tp, class _A0, class _A1>
-struct _LIBCPP_TEMPLATE_VIS is_constructible<_Tp, _A0, _A1, __is_construct::__nat>
-    : public __is_constructible2_void_check<is_void<_Tp>::value
-                                        || is_abstract<_Tp>::value
-                                        || is_function<_Tp>::value
-                                        || is_void<_A0>::value
-                                        || is_void<_A1>::value,
-                                           _Tp, _A0, _A1>
-    {};
-
-//      Array types are default constructible if their element type
-//      is default constructible
-
-template <class _Ap, size_t _Np>
-struct __is_constructible0_imp<false, _Ap[_Np]>
-    : public is_constructible<typename remove_all_extents<_Ap>::type>
-    {};
-
-template <class _Ap, size_t _Np, class _A0>
-struct __is_constructible1_imp<false, _Ap[_Np], _A0>
-    : public false_type
-    {};
-
-template <class _Ap, size_t _Np, class _A0, class _A1>
-struct __is_constructible2_imp<false, _Ap[_Np], _A0, _A1>
-    : public false_type
-    {};
-
-template <class _Ap, size_t _Np, class _A0, class _A1, class _A2>
-struct __is_constructible3_imp<false, _Ap[_Np], _A0, _A1, _A2>
-    : public false_type
-    {};
-
-//      Incomplete array types are not constructible
-
-template <class _Ap>
-struct __is_constructible0_imp<false, _Ap[]>
-    : public false_type
-    {};
-
-template <class _Ap, class _A0>
-struct __is_constructible1_imp<false, _Ap[], _A0>
-    : public false_type
-    {};
-
-template <class _Ap, class _A0, class _A1>
-struct __is_constructible2_imp<false, _Ap[], _A0, _A1>
-    : public false_type
-    {};
-
-template <class _Ap, class _A0, class _A1, class _A2>
-struct __is_constructible3_imp<false, _Ap[], _A0, _A1, _A2>
-    : public false_type
-    {};
-
-#endif // __has_feature(is_constructible)
-
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-template <class _Tp, class ..._Args>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_constructible_v
-    = is_constructible<_Tp, _Args...>::value;
-#endif
-
-// is_default_constructible
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_default_constructible
-    : public is_constructible<_Tp>
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_default_constructible_v
-    = is_default_constructible<_Tp>::value;
-#endif
-
-// is_copy_constructible
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_copy_constructible
-    : public is_constructible<_Tp,
-                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_copy_constructible_v
-    = is_copy_constructible<_Tp>::value;
-#endif
-
-// is_move_constructible
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_move_constructible
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    : public is_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
-#else
-    : public is_copy_constructible<_Tp>
-#endif
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_move_constructible_v
-    = is_move_constructible<_Tp>::value;
-#endif
-
-// is_trivially_constructible
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-#if __has_feature(is_trivially_constructible) || _GNUC_VER >= 501
-
-template <class _Tp, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible
-    : integral_constant<bool, __is_trivially_constructible(_Tp, _Args...)>
-{
-};
-
-#else  // !__has_feature(is_trivially_constructible)
-
-template <class _Tp, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible
-    : false_type
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp>
-#if __has_feature(has_trivial_constructor) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_trivial_constructor(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value>
-#endif
-{
-};
-
-template <class _Tp>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, _Tp&&>
-#else
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, _Tp>
-#endif
-    : integral_constant<bool, is_scalar<_Tp>::value>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, const _Tp&>
-    : integral_constant<bool, is_scalar<_Tp>::value>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, _Tp&>
-    : integral_constant<bool, is_scalar<_Tp>::value>
-{
-};
-
-#endif  // !__has_feature(is_trivially_constructible)
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Tp, class _A0 = __is_construct::__nat,
-                     class _A1 = __is_construct::__nat>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible
-    : false_type
-{
-};
-
-#if __has_feature(is_trivially_constructible) || _GNUC_VER >= 501
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, __is_construct::__nat,
-                                                       __is_construct::__nat>
-    : integral_constant<bool, __is_trivially_constructible(_Tp)>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, _Tp,
-                                                       __is_construct::__nat>
-    : integral_constant<bool, __is_trivially_constructible(_Tp, _Tp)>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, const _Tp&,
-                                                       __is_construct::__nat>
-    : integral_constant<bool, __is_trivially_constructible(_Tp, const _Tp&)>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, _Tp&,
-                                                       __is_construct::__nat>
-    : integral_constant<bool, __is_trivially_constructible(_Tp, _Tp&)>
-{
-};
-
-#else  // !__has_feature(is_trivially_constructible)
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, __is_construct::__nat,
-                                                       __is_construct::__nat>
-    : integral_constant<bool, is_scalar<_Tp>::value>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, _Tp,
-                                                       __is_construct::__nat>
-    : integral_constant<bool, is_scalar<_Tp>::value>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, const _Tp&,
-                                                       __is_construct::__nat>
-    : integral_constant<bool, is_scalar<_Tp>::value>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_trivially_constructible<_Tp, _Tp&,
-                                                       __is_construct::__nat>
-    : integral_constant<bool, is_scalar<_Tp>::value>
-{
-};
-
-#endif  // !__has_feature(is_trivially_constructible)
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-template <class _Tp, class... _Args>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivially_constructible_v
-    = is_trivially_constructible<_Tp, _Args...>::value;
-#endif
-
-// is_trivially_default_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_default_constructible
-    : public is_trivially_constructible<_Tp>
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivially_default_constructible_v
-    = is_trivially_default_constructible<_Tp>::value;
-#endif
-
-// is_trivially_copy_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_copy_constructible
-    : public is_trivially_constructible<_Tp, typename add_lvalue_reference<const _Tp>::type>
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivially_copy_constructible_v
-    = is_trivially_copy_constructible<_Tp>::value;
-#endif
-
-// is_trivially_move_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_move_constructible
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    : public is_trivially_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
-#else
-    : public is_trivially_copy_constructible<_Tp>
-#endif
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivially_move_constructible_v
-    = is_trivially_move_constructible<_Tp>::value;
-#endif
-
-// is_trivially_assignable
-
-#if __has_feature(is_trivially_assignable) || _GNUC_VER >= 501
-
-template <class _Tp, class _Arg>
-struct is_trivially_assignable
-    : integral_constant<bool, __is_trivially_assignable(_Tp, _Arg)>
-{
-};
-
-#else  // !__has_feature(is_trivially_assignable)
-
-template <class _Tp, class _Arg>
-struct is_trivially_assignable
-    : public false_type {};
-
-template <class _Tp>
-struct is_trivially_assignable<_Tp&, _Tp>
-    : integral_constant<bool, is_scalar<_Tp>::value> {};
-
-template <class _Tp>
-struct is_trivially_assignable<_Tp&, _Tp&>
-    : integral_constant<bool, is_scalar<_Tp>::value> {};
-
-template <class _Tp>
-struct is_trivially_assignable<_Tp&, const _Tp&>
-    : integral_constant<bool, is_scalar<_Tp>::value> {};
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp>
-struct is_trivially_assignable<_Tp&, _Tp&&>
-    : integral_constant<bool, is_scalar<_Tp>::value> {};
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-#endif  // !__has_feature(is_trivially_assignable)
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp, class _Arg>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivially_assignable_v
-    = is_trivially_assignable<_Tp, _Arg>::value;
-#endif
-
-// is_trivially_copy_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_copy_assignable
-    : public is_trivially_assignable<typename add_lvalue_reference<_Tp>::type,
-                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivially_copy_assignable_v
-    = is_trivially_copy_assignable<_Tp>::value;
-#endif
-
-// is_trivially_move_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_move_assignable
-    : public is_trivially_assignable<typename add_lvalue_reference<_Tp>::type,
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-                                     typename add_rvalue_reference<_Tp>::type>
-#else
-                                     typename add_lvalue_reference<_Tp>::type>
-#endif
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivially_move_assignable_v
-    = is_trivially_move_assignable<_Tp>::value;
-#endif
-
-// is_trivially_destructible
-
-#if __has_feature(has_trivial_destructor) || (_GNUC_VER >= 403)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible
-    : public integral_constant<bool, is_destructible<_Tp>::value && __has_trivial_destructor(_Tp)> {};
-
-#else
-
-template <class _Tp> struct __libcpp_trivial_destructor
-    : public integral_constant<bool, is_scalar<_Tp>::value ||
-                                     is_reference<_Tp>::value> {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible
-    : public __libcpp_trivial_destructor<typename remove_all_extents<_Tp>::type> {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_destructible<_Tp[]>
-    : public false_type {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivially_destructible_v
-    = is_trivially_destructible<_Tp>::value;
-#endif
-
-// is_nothrow_constructible
-
-#if 0
-template <class _Tp, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible
-    : public integral_constant<bool, __is_nothrow_constructible(_Tp(_Args...))>
-{
-};
-
-#else
-
-#ifndef _LIBCPP_HAS_NO_VARIADICS
-
-#if __has_feature(cxx_noexcept) || (_GNUC_VER >= 407 && __cplusplus >= 201103L)
-
-template <bool, bool, class _Tp, class... _Args> struct __libcpp_is_nothrow_constructible;
-
-template <class _Tp, class... _Args>
-struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/false, _Tp, _Args...>
-    : public integral_constant<bool, noexcept(_Tp(declval<_Args>()...))>
-{
-};
-
-template <class _Tp>
-void __implicit_conversion_to(_Tp) noexcept { }
-
-template <class _Tp, class _Arg>
-struct __libcpp_is_nothrow_constructible</*is constructible*/true, /*is reference*/true, _Tp, _Arg>
-    : public integral_constant<bool, noexcept(__implicit_conversion_to<_Tp>(declval<_Arg>()))>
-{
-};
-
-template <class _Tp, bool _IsReference, class... _Args>
-struct __libcpp_is_nothrow_constructible</*is constructible*/false, _IsReference, _Tp, _Args...>
-    : public false_type
-{
-};
-
-template <class _Tp, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible
-    : __libcpp_is_nothrow_constructible<is_constructible<_Tp, _Args...>::value, is_reference<_Tp>::value, _Tp, _Args...>
-{
-};
-
-template <class _Tp, size_t _Ns>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp[_Ns]>
-    : __libcpp_is_nothrow_constructible<is_constructible<_Tp>::value, is_reference<_Tp>::value, _Tp>
-{
-};
-
-#else  // __has_feature(cxx_noexcept)
-
-template <class _Tp, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible
-    : false_type
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp>
-#if __has_feature(has_nothrow_constructor) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_constructor(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value>
-#endif
-{
-};
-
-template <class _Tp>
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp, _Tp&&>
-#else
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp, _Tp>
-#endif
-#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_copy(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value>
-#endif
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp, const _Tp&>
-#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_copy(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value>
-#endif
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp, _Tp&>
-#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_copy(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value>
-#endif
-{
-};
-
-#endif  // __has_feature(cxx_noexcept)
-
-#else  // _LIBCPP_HAS_NO_VARIADICS
-
-template <class _Tp, class _A0 = __is_construct::__nat,
-                     class _A1 = __is_construct::__nat>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible
-    : false_type
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp, __is_construct::__nat,
-                                                       __is_construct::__nat>
-#if __has_feature(has_nothrow_constructor) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_constructor(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value>
-#endif
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp, _Tp,
-                                                       __is_construct::__nat>
-#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_copy(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value>
-#endif
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp, const _Tp&,
-                                                       __is_construct::__nat>
-#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_copy(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value>
-#endif
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_constructible<_Tp, _Tp&,
-                                                       __is_construct::__nat>
-#if __has_feature(has_nothrow_copy) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_copy(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value>
-#endif
-{
-};
-
-#endif  // _LIBCPP_HAS_NO_VARIADICS
-#endif  // __has_feature(is_nothrow_constructible)
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
-template <class _Tp, class ..._Args>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_nothrow_constructible_v
-    = is_nothrow_constructible<_Tp, _Args...>::value;
-#endif
-
-// is_nothrow_default_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_default_constructible
-    : public is_nothrow_constructible<_Tp>
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_nothrow_default_constructible_v
-    = is_nothrow_default_constructible<_Tp>::value;
-#endif
-
-// is_nothrow_copy_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_copy_constructible
-    : public is_nothrow_constructible<_Tp,
-                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_nothrow_copy_constructible_v
-    = is_nothrow_copy_constructible<_Tp>::value;
-#endif
-
-// is_nothrow_move_constructible
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_move_constructible
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-    : public is_nothrow_constructible<_Tp, typename add_rvalue_reference<_Tp>::type>
-#else
-    : public is_nothrow_copy_constructible<_Tp>
-#endif
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_nothrow_move_constructible_v
-    = is_nothrow_move_constructible<_Tp>::value;
-#endif
-
-// is_nothrow_assignable
-
-#if __has_feature(cxx_noexcept) || (_GNUC_VER >= 407 && __cplusplus >= 201103L)
-
-template <bool, class _Tp, class _Arg> struct __libcpp_is_nothrow_assignable;
-
-template <class _Tp, class _Arg>
-struct __libcpp_is_nothrow_assignable<false, _Tp, _Arg>
-    : public false_type
-{
-};
-
-template <class _Tp, class _Arg>
-struct __libcpp_is_nothrow_assignable<true, _Tp, _Arg>
-    : public integral_constant<bool, noexcept(_VSTD::declval<_Tp>() = _VSTD::declval<_Arg>()) >
-{
-};
-
-template <class _Tp, class _Arg>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable
-    : public __libcpp_is_nothrow_assignable<is_assignable<_Tp, _Arg>::value, _Tp, _Arg>
-{
-};
-
-#else  // __has_feature(cxx_noexcept)
-
-template <class _Tp, class _Arg>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable
-    : public false_type {};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable<_Tp&, _Tp>
-#if __has_feature(has_nothrow_assign) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_assign(_Tp)> {};
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value> {};
-#endif
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable<_Tp&, _Tp&>
-#if __has_feature(has_nothrow_assign) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_assign(_Tp)> {};
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value> {};
-#endif
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_assignable<_Tp&, const _Tp&>
-#if __has_feature(has_nothrow_assign) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_assign(_Tp)> {};
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value> {};
-#endif
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp>
-struct is_nothrow_assignable<_Tp&, _Tp&&>
-#if __has_feature(has_nothrow_assign) || (_GNUC_VER >= 403)
-    : integral_constant<bool, __has_nothrow_assign(_Tp)> {};
-#else
-    : integral_constant<bool, is_scalar<_Tp>::value> {};
-#endif
-
-#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-#endif  // __has_feature(cxx_noexcept)
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp, class _Arg>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_nothrow_assignable_v
-    = is_nothrow_assignable<_Tp, _Arg>::value;
-#endif
-
-// is_nothrow_copy_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_copy_assignable
-    : public is_nothrow_assignable<typename add_lvalue_reference<_Tp>::type,
-                  typename add_lvalue_reference<typename add_const<_Tp>::type>::type> {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_nothrow_copy_assignable_v
-    = is_nothrow_copy_assignable<_Tp>::value;
-#endif
-
-// is_nothrow_move_assignable
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_move_assignable
-    : public is_nothrow_assignable<typename add_lvalue_reference<_Tp>::type,
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-                                     typename add_rvalue_reference<_Tp>::type>
-#else
-                                     typename add_lvalue_reference<_Tp>::type>
-#endif
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_nothrow_move_assignable_v
-    = is_nothrow_move_assignable<_Tp>::value;
-#endif
-
-// is_nothrow_destructible
-
-#if __has_feature(cxx_noexcept) || (_GNUC_VER >= 407 && __cplusplus >= 201103L)
-
-template <bool, class _Tp> struct __libcpp_is_nothrow_destructible;
-
-template <class _Tp>
-struct __libcpp_is_nothrow_destructible<false, _Tp>
-    : public false_type
-{
-};
-
-template <class _Tp>
-struct __libcpp_is_nothrow_destructible<true, _Tp>
-    : public integral_constant<bool, noexcept(_VSTD::declval<_Tp>().~_Tp()) >
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible
-    : public __libcpp_is_nothrow_destructible<is_destructible<_Tp>::value, _Tp>
-{
-};
-
-template <class _Tp, size_t _Ns>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp[_Ns]>
-    : public is_nothrow_destructible<_Tp>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp&>
-    : public true_type
-{
-};
-
-#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp&&>
-    : public true_type
-{
-};
-
-#endif
-
-#else
-
-template <class _Tp> struct __libcpp_nothrow_destructor
-    : public integral_constant<bool, is_scalar<_Tp>::value ||
-                                     is_reference<_Tp>::value> {};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible
-    : public __libcpp_nothrow_destructor<typename remove_all_extents<_Tp>::type> {};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_destructible<_Tp[]>
-    : public false_type {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_nothrow_destructible_v
-    = is_nothrow_destructible<_Tp>::value;
-#endif
-
-// is_pod
-
-#if __has_feature(is_pod) || (_GNUC_VER >= 403)
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_pod
-    : public integral_constant<bool, __is_pod(_Tp)> {};
-
-#else
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_pod
-    : public integral_constant<bool, is_trivially_default_constructible<_Tp>::value   &&
-                                     is_trivially_copy_constructible<_Tp>::value      &&
-                                     is_trivially_copy_assignable<_Tp>::value    &&
-                                     is_trivially_destructible<_Tp>::value> {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_pod_v
-    = is_pod<_Tp>::value;
-#endif
-
-// is_literal_type;
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_literal_type
-#ifdef _LIBCPP_IS_LITERAL
-    : public integral_constant<bool, _LIBCPP_IS_LITERAL(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<typename remove_all_extents<_Tp>::type>::value ||
-                              is_reference<typename remove_all_extents<_Tp>::type>::value>
-#endif
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_literal_type_v
-    = is_literal_type<_Tp>::value;
-#endif
-
-// is_standard_layout;
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_standard_layout
-#if __has_feature(is_standard_layout) || (_GNUC_VER >= 407)
-    : public integral_constant<bool, __is_standard_layout(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<typename remove_all_extents<_Tp>::type>::value>
-#endif
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_standard_layout_v
-    = is_standard_layout<_Tp>::value;
-#endif
-
-// is_trivially_copyable;
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivially_copyable
-#if __has_feature(is_trivially_copyable)
-    : public integral_constant<bool, __is_trivially_copyable(_Tp)>
-#elif _GNUC_VER >= 501
-    : public integral_constant<bool, !is_volatile<_Tp>::value && __is_trivially_copyable(_Tp)>
-#else
-    : integral_constant<bool, is_scalar<typename remove_all_extents<_Tp>::type>::value>
-#endif
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivially_copyable_v
-    = is_trivially_copyable<_Tp>::value;
-#endif
-
-// is_trivial;
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS is_trivial
-#if __has_feature(is_trivial) || _GNUC_VER >= 407
-    : public integral_constant<bool, __is_trivial(_Tp)>
-#else
-    : integral_constant<bool, is_trivially_copyable<_Tp>::value &&
-                                 is_trivially_default_constructible<_Tp>::value>
-#endif
-    {};
-
-#if _LIBCPP_STD_VER > 14 && !defined(_LIBCPP_HAS_NO_VARIABLE_TEMPLATES)
-template <class _Tp>
-_LIBCPP_INLINE_VAR _LIBCPP_CONSTEXPR bool is_trivial_v
-    = is_trivial<_Tp>::value;
-#endif
-
-template <class _Tp> struct __is_reference_wrapper_impl : public false_type {};
-template <class _Tp> struct __is_reference_wrapper_impl<reference_wrapper<_Tp> > : public true_type {};
-template <class _Tp> struct __is_reference_wrapper
-    : public __is_reference_wrapper_impl<typename remove_cv<_Tp>::type> {};
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Fp, class _A0,
-         class _DecayFp = typename decay<_Fp>::type,
-         class _DecayA0 = typename decay<_A0>::type,
-         class _ClassT = typename __member_pointer_class_type<_DecayFp>::type>
-using __enable_if_bullet1 = typename enable_if
-    <
-        is_member_function_pointer<_DecayFp>::value
-        && is_base_of<_ClassT, _DecayA0>::value
-    >::type;
-
-template <class _Fp, class _A0,
-         class _DecayFp = typename decay<_Fp>::type,
-         class _DecayA0 = typename decay<_A0>::type>
-using __enable_if_bullet2 = typename enable_if
-    <
-        is_member_function_pointer<_DecayFp>::value
-        && __is_reference_wrapper<_DecayA0>::value
-    >::type;
-
-template <class _Fp, class _A0,
-         class _DecayFp = typename decay<_Fp>::type,
-         class _DecayA0 = typename decay<_A0>::type,
-         class _ClassT = typename __member_pointer_class_type<_DecayFp>::type>
-using __enable_if_bullet3 = typename enable_if
-    <
-        is_member_function_pointer<_DecayFp>::value
-        && !is_base_of<_ClassT, _DecayA0>::value
-        && !__is_reference_wrapper<_DecayA0>::value
-    >::type;
-
-template <class _Fp, class _A0,
-         class _DecayFp = typename decay<_Fp>::type,
-         class _DecayA0 = typename decay<_A0>::type,
-         class _ClassT = typename __member_pointer_class_type<_DecayFp>::type>
-using __enable_if_bullet4 = typename enable_if
-    <
-        is_member_object_pointer<_DecayFp>::value
-        && is_base_of<_ClassT, _DecayA0>::value
-    >::type;
-
-template <class _Fp, class _A0,
-         class _DecayFp = typename decay<_Fp>::type,
-         class _DecayA0 = typename decay<_A0>::type>
-using __enable_if_bullet5 = typename enable_if
-    <
-        is_member_object_pointer<_DecayFp>::value
-        && __is_reference_wrapper<_DecayA0>::value
-    >::type;
-
-template <class _Fp, class _A0,
-         class _DecayFp = typename decay<_Fp>::type,
-         class _DecayA0 = typename decay<_A0>::type,
-         class _ClassT = typename __member_pointer_class_type<_DecayFp>::type>
-using __enable_if_bullet6 = typename enable_if
-    <
-        is_member_object_pointer<_DecayFp>::value
-        && !is_base_of<_ClassT, _DecayA0>::value
-        && !__is_reference_wrapper<_DecayA0>::value
-    >::type;
-
-// __invoke forward declarations
-
-// fall back - none of the bullets
-
-#define _LIBCPP_INVOKE_RETURN(...) \
-    noexcept(noexcept(__VA_ARGS__)) -> decltype(__VA_ARGS__) \
-    { return __VA_ARGS__; }
-
-template <class ..._Args>
-auto __invoke(__any, _Args&& ...__args) -> __nat;
-
-template <class ..._Args>
-auto __invoke_constexpr(__any, _Args&& ...__args) -> __nat;
-
-// bullets 1, 2 and 3
-
-template <class _Fp, class _A0, class ..._Args,
-          class = __enable_if_bullet1<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN((_VSTD::forward<_A0>(__a0).*__f)(_VSTD::forward<_Args>(__args)...))
-
-template <class _Fp, class _A0, class ..._Args,
-          class = __enable_if_bullet1<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR auto
-__invoke_constexpr(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN((_VSTD::forward<_A0>(__a0).*__f)(_VSTD::forward<_Args>(__args)...))
-
-template <class _Fp, class _A0, class ..._Args,
-          class = __enable_if_bullet2<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN((__a0.get().*__f)(_VSTD::forward<_Args>(__args)...))
-
-template <class _Fp, class _A0, class ..._Args,
-          class = __enable_if_bullet2<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR auto
-__invoke_constexpr(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN((__a0.get().*__f)(_VSTD::forward<_Args>(__args)...))
-
-template <class _Fp, class _A0, class ..._Args,
-          class = __enable_if_bullet3<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-__invoke(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN(((*_VSTD::forward<_A0>(__a0)).*__f)(_VSTD::forward<_Args>(__args)...))
-
-template <class _Fp, class _A0, class ..._Args,
-          class = __enable_if_bullet3<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR auto
-__invoke_constexpr(_Fp&& __f, _A0&& __a0, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN(((*_VSTD::forward<_A0>(__a0)).*__f)(_VSTD::forward<_Args>(__args)...))
-
-// bullets 4, 5 and 6
-
-template <class _Fp, class _A0,
-          class = __enable_if_bullet4<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-__invoke(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN(_VSTD::forward<_A0>(__a0).*__f)
-
-template <class _Fp, class _A0,
-          class = __enable_if_bullet4<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR auto
-__invoke_constexpr(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN(_VSTD::forward<_A0>(__a0).*__f)
-
-template <class _Fp, class _A0,
-          class = __enable_if_bullet5<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-__invoke(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN(__a0.get().*__f)
-
-template <class _Fp, class _A0,
-          class = __enable_if_bullet5<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR auto
-__invoke_constexpr(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN(__a0.get().*__f)
-
-template <class _Fp, class _A0,
-          class = __enable_if_bullet6<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-__invoke(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN((*_VSTD::forward<_A0>(__a0)).*__f)
-
-template <class _Fp, class _A0,
-          class = __enable_if_bullet6<_Fp, _A0>>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR auto
-__invoke_constexpr(_Fp&& __f, _A0&& __a0)
-_LIBCPP_INVOKE_RETURN((*_VSTD::forward<_A0>(__a0)).*__f)
-
-// bullet 7
-
-template <class _Fp, class ..._Args>
-inline _LIBCPP_INLINE_VISIBILITY
-auto
-__invoke(_Fp&& __f, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN(_VSTD::forward<_Fp>(__f)(_VSTD::forward<_Args>(__args)...))
-
-template <class _Fp, class ..._Args>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_CONSTEXPR auto
-__invoke_constexpr(_Fp&& __f, _Args&& ...__args)
-_LIBCPP_INVOKE_RETURN(_VSTD::forward<_Fp>(__f)(_VSTD::forward<_Args>(__args)...))
-
-#undef _LIBCPP_INVOKE_RETURN
-
-// __invokable
-
-template <class _Ret, class _Fp, class ..._Args>
-struct __invokable_r
-{
-    // FIXME: Check that _Ret, _Fp, and _Args... are all complete types, cv void,
-    // or incomplete array types as required by the standard.
-    using _Result = decltype(
-        _VSTD::__invoke(_VSTD::declval<_Fp>(), _VSTD::declval<_Args>()...));
-
-    using type =
-        typename conditional<
-            !is_same<_Result, __nat>::value,
-            typename conditional<
-                is_void<_Ret>::value,
-                true_type,
-                is_convertible<_Result, _Ret>
-            >::type,
-            false_type
-        >::type;
-    static const bool value = type::value;
-};
-
-template <class _Fp, class ..._Args>
-using __invokable = __invokable_r<void, _Fp, _Args...>;
-
-template <bool _IsInvokable, bool _IsCVVoid, class _Ret, class _Fp, class ..._Args>
-struct __nothrow_invokable_r_imp {
-  static const bool value = false;
-};
-
-template <class _Ret, class _Fp, class ..._Args>
-struct __nothrow_invokable_r_imp<true, false, _Ret, _Fp, _Args...>
-{
-    typedef __nothrow_invokable_r_imp _ThisT;
-
-    template <class _Tp>
-    static void __test_noexcept(_Tp) noexcept;
-
-    static const bool value = noexcept(_ThisT::__test_noexcept<_Ret>(
-        _VSTD::__invoke(_VSTD::declval<_Fp>(), _VSTD::declval<_Args>()...)));
-};
-
-template <class _Ret, class _Fp, class ..._Args>
-struct __nothrow_invokable_r_imp<true, true, _Ret, _Fp, _Args...>
-{
-    static const bool value = noexcept(
-        _VSTD::__invoke(_VSTD::declval<_Fp>(), _VSTD::declval<_Args>()...));
-};
-
-template <class _Ret, class _Fp, class ..._Args>
-using __nothrow_invokable_r =
-    __nothrow_invokable_r_imp<
-            __invokable_r<_Ret, _Fp, _Args...>::value,
-            is_void<_Ret>::value,
-            _Ret, _Fp, _Args...
-    >;
-
-template <class _Fp, class ..._Args>
-using __nothrow_invokable =
-    __nothrow_invokable_r_imp<
-            __invokable<_Fp, _Args...>::value,
-            true, void, _Fp, _Args...
-    >;
-
-template <class _Fp, class ..._Args>
-struct __invoke_of
-    : public enable_if<
-        __invokable<_Fp, _Args...>::value,
-        typename __invokable_r<void, _Fp, _Args...>::_Result>
-{
-};
-
-// result_of
-
-template <class _Fp, class ..._Args>
-class _LIBCPP_TEMPLATE_VIS result_of<_Fp(_Args...)>
-    : public __invoke_of<_Fp, _Args...>
-{
-};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using result_of_t = typename result_of<_Tp>::type;
-#endif
-
-#if _LIBCPP_STD_VER > 14
-
-// invoke_result
-
-template <class _Fn, class... _Args>
-struct _LIBCPP_TEMPLATE_VIS invoke_result
-    : __invoke_of<_Fn, _Args...>
-{
-};
-
-template <class _Fn, class... _Args>
-using invoke_result_t = typename invoke_result<_Fn, _Args...>::type;
-
-// is_invocable
-
-template <class _Fn, class ..._Args>
-struct _LIBCPP_TEMPLATE_VIS is_invocable
-    : integral_constant<bool, __invokable<_Fn, _Args...>::value> {};
-
-template <class _Ret, class _Fn, class ..._Args>
-struct _LIBCPP_TEMPLATE_VIS is_invocable_r
-    : integral_constant<bool, __invokable_r<_Ret, _Fn, _Args...>::value> {};
-
-template <class _Fn, class ..._Args>
-_LIBCPP_INLINE_VAR constexpr bool is_invocable_v
-    = is_invocable<_Fn, _Args...>::value;
-
-template <class _Ret, class _Fn, class ..._Args>
-_LIBCPP_INLINE_VAR constexpr bool is_invocable_r_v
-    = is_invocable_r<_Ret, _Fn, _Args...>::value;
-
-// is_nothrow_invocable
-
-template <class _Fn, class ..._Args>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_invocable
-    : integral_constant<bool, __nothrow_invokable<_Fn, _Args...>::value> {};
-
-template <class _Ret, class _Fn, class ..._Args>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_invocable_r
-    : integral_constant<bool, __nothrow_invokable_r<_Ret, _Fn, _Args...>::value> {};
-
-template <class _Fn, class ..._Args>
-_LIBCPP_INLINE_VAR constexpr bool is_nothrow_invocable_v
-    = is_nothrow_invocable<_Fn, _Args...>::value;
-
-template <class _Ret, class _Fn, class ..._Args>
-_LIBCPP_INLINE_VAR constexpr bool is_nothrow_invocable_r_v
-    = is_nothrow_invocable_r<_Ret, _Fn, _Args...>::value;
-
-#endif // _LIBCPP_STD_VER > 14
-
-#endif  // !defined(_LIBCPP_CXX03_LANG)
-
-template <class _Tp> struct __is_swappable;
-template <class _Tp> struct __is_nothrow_swappable;
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-#ifndef _LIBCPP_CXX03_LANG
-typename enable_if
-<
-    is_move_constructible<_Tp>::value &&
-    is_move_assignable<_Tp>::value
->::type
-#else
-void
-#endif
-swap(_Tp& __x, _Tp& __y) _NOEXCEPT_(is_nothrow_move_constructible<_Tp>::value &&
-                                    is_nothrow_move_assignable<_Tp>::value)
-{
-    _Tp __t(_VSTD::move(__x));
-    __x = _VSTD::move(__y);
-    __y = _VSTD::move(__t);
-}
-
-template<class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if<
-    __is_swappable<_Tp>::value
->::type
-swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value);
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-iter_swap(_ForwardIterator1 __a, _ForwardIterator2 __b)
-    //                                  _NOEXCEPT_(_NOEXCEPT_(swap(*__a, *__b)))
-               _NOEXCEPT_(_NOEXCEPT_(swap(*_VSTD::declval<_ForwardIterator1>(),
-                                          *_VSTD::declval<_ForwardIterator2>())))
-{
-    swap(*__a, *__b);
-}
-
-// __swappable
-
-namespace __detail
-{
-// ALL generic swap overloads MUST already have a declaration available at this point.
-
-template <class _Tp, class _Up = _Tp,
-          bool _NotVoid = !is_void<_Tp>::value && !is_void<_Up>::value>
-struct __swappable_with
-{
-    template <class _LHS, class _RHS>
-    static decltype(swap(_VSTD::declval<_LHS>(), _VSTD::declval<_RHS>()))
-    __test_swap(int);
-    template <class, class>
-    static __nat __test_swap(long);
-
-    // Extra parens are needed for the C++03 definition of decltype.
-    typedef decltype((__test_swap<_Tp, _Up>(0))) __swap1;
-    typedef decltype((__test_swap<_Up, _Tp>(0))) __swap2;
-
-    static const bool value = !is_same<__swap1, __nat>::value
-                           && !is_same<__swap2, __nat>::value;
-};
-
-template <class _Tp, class _Up>
-struct __swappable_with<_Tp, _Up,  false> : false_type {};
-
-template <class _Tp, class _Up = _Tp, bool _Swappable = __swappable_with<_Tp, _Up>::value>
-struct __nothrow_swappable_with {
-  static const bool value =
-#ifndef _LIBCPP_HAS_NO_NOEXCEPT
-      noexcept(swap(_VSTD::declval<_Tp>(), _VSTD::declval<_Up>()))
-  &&  noexcept(swap(_VSTD::declval<_Up>(), _VSTD::declval<_Tp>()));
-#else
-      false;
-#endif
-};
-
-template <class _Tp, class _Up>
-struct __nothrow_swappable_with<_Tp, _Up, false> : false_type {};
-
-}  // __detail
-
-template <class _Tp>
-struct __is_swappable
-    : public integral_constant<bool, __detail::__swappable_with<_Tp&>::value>
-{
-};
-
-template <class _Tp>
-struct __is_nothrow_swappable
-    : public integral_constant<bool, __detail::__nothrow_swappable_with<_Tp&>::value>
-{
-};
-
-#if _LIBCPP_STD_VER > 14
-
-template <class _Tp, class _Up>
-struct _LIBCPP_TEMPLATE_VIS is_swappable_with
-    : public integral_constant<bool, __detail::__swappable_with<_Tp, _Up>::value>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_swappable
-    : public conditional<
-        __is_referenceable<_Tp>::value,
-        is_swappable_with<
-            typename add_lvalue_reference<_Tp>::type,
-            typename add_lvalue_reference<_Tp>::type>,
-        false_type
-    >::type
-{
-};
-
-template <class _Tp, class _Up>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_swappable_with
-    : public integral_constant<bool, __detail::__nothrow_swappable_with<_Tp, _Up>::value>
-{
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS is_nothrow_swappable
-    : public conditional<
-        __is_referenceable<_Tp>::value,
-        is_nothrow_swappable_with<
-            typename add_lvalue_reference<_Tp>::type,
-            typename add_lvalue_reference<_Tp>::type>,
-        false_type
-    >::type
-{
-};
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VAR constexpr bool is_swappable_with_v
-    = is_swappable_with<_Tp, _Up>::value;
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr bool is_swappable_v
-    = is_swappable<_Tp>::value;
-
-template <class _Tp, class _Up>
-_LIBCPP_INLINE_VAR constexpr bool is_nothrow_swappable_with_v
-    = is_nothrow_swappable_with<_Tp, _Up>::value;
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr bool is_nothrow_swappable_v
-    = is_nothrow_swappable<_Tp>::value;
-
-#endif // _LIBCPP_STD_VER > 14
-
-#ifdef _LIBCPP_UNDERLYING_TYPE
-
-template <class _Tp>
-struct underlying_type
-{
-    typedef _LIBCPP_UNDERLYING_TYPE(_Tp) type;
-};
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp> using underlying_type_t = typename underlying_type<_Tp>::type;
-#endif
-
-#else  // _LIBCPP_UNDERLYING_TYPE
-
-template <class _Tp, bool _Support = false>
-struct underlying_type
-{
-    static_assert(_Support, "The underyling_type trait requires compiler "
-                            "support. Either no such support exists or "
-                            "libc++ does not know how to use it.");
-};
-
-#endif // _LIBCPP_UNDERLYING_TYPE
-
-
-template <class _Tp, bool = is_enum<_Tp>::value>
-struct __sfinae_underlying_type
-{
-    typedef typename underlying_type<_Tp>::type type;
-    typedef decltype(((type)1) + 0) __promoted_type;
-};
-
-template <class _Tp>
-struct __sfinae_underlying_type<_Tp, false> {};
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-int __convert_to_integral(int __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-unsigned __convert_to_integral(unsigned __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-long __convert_to_integral(long __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-unsigned long __convert_to_integral(unsigned long __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-long long __convert_to_integral(long long __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-unsigned long long __convert_to_integral(unsigned long long __val) {return __val; }
-
-template<typename _Fp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename enable_if<is_floating_point<_Fp>::value, long long>::type
- __convert_to_integral(_Fp __val) { return __val; }
-
-#ifndef _LIBCPP_HAS_NO_INT128
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-__int128_t __convert_to_integral(__int128_t __val) { return __val; }
-
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-__uint128_t __convert_to_integral(__uint128_t __val) { return __val; }
-#endif
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-typename __sfinae_underlying_type<_Tp>::__promoted_type
-__convert_to_integral(_Tp __val) { return __val; }
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-struct __has_operator_addressof_member_imp
-{
-    template <class _Up>
-        static auto __test(int)
-            -> typename __select_2nd<decltype(_VSTD::declval<_Up>().operator&()), true_type>::type;
-    template <class>
-        static auto __test(long) -> false_type;
-
-    static const bool value = decltype(__test<_Tp>(0))::value;
-};
-
-template <class _Tp>
-struct __has_operator_addressof_free_imp
-{
-    template <class _Up>
-        static auto __test(int)
-            -> typename __select_2nd<decltype(operator&(_VSTD::declval<_Up>())), true_type>::type;
-    template <class>
-        static auto __test(long) -> false_type;
-
-    static const bool value = decltype(__test<_Tp>(0))::value;
-};
-
-template <class _Tp>
-struct __has_operator_addressof
-    : public integral_constant<bool, __has_operator_addressof_member_imp<_Tp>::value
-                                  || __has_operator_addressof_free_imp<_Tp>::value>
-{};
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER > 14
-
-template <class...> using void_t = void;
-
-# ifndef _LIBCPP_HAS_NO_VARIADICS
-template <class... _Args>
-struct conjunction : __and_<_Args...> {};
-template<class... _Args>
-_LIBCPP_INLINE_VAR constexpr bool conjunction_v
-    = conjunction<_Args...>::value;
-
-template <class... _Args>
-struct disjunction : __or_<_Args...> {};
-template<class... _Args>
-_LIBCPP_INLINE_VAR constexpr bool disjunction_v
-    = disjunction<_Args...>::value;
-
-template <class _Tp>
-struct negation : __not_<_Tp> {};
-template<class _Tp>
-_LIBCPP_INLINE_VAR constexpr bool negation_v
-    = negation<_Tp>::value;
-# endif // _LIBCPP_HAS_NO_VARIADICS
-#endif  // _LIBCPP_STD_VER > 14
-
-// These traits are used in __tree and __hash_table
-#ifndef _LIBCPP_CXX03_LANG
-struct __extract_key_fail_tag {};
-struct __extract_key_self_tag {};
-struct __extract_key_first_tag {};
-
-template <class _ValTy, class _Key,
-          class _RawValTy = typename __unconstref<_ValTy>::type>
-struct __can_extract_key
-    : conditional<is_same<_RawValTy, _Key>::value, __extract_key_self_tag,
-                  __extract_key_fail_tag>::type {};
-
-template <class _Pair, class _Key, class _First, class _Second>
-struct __can_extract_key<_Pair, _Key, pair<_First, _Second>>
-    : conditional<is_same<typename remove_const<_First>::type, _Key>::value,
-                  __extract_key_first_tag, __extract_key_fail_tag>::type {};
-
-// __can_extract_map_key uses true_type/false_type instead of the tags.
-// It returns true if _Key != _ContainerValueTy (the container is a map not a set)
-// and _ValTy == _Key.
-template <class _ValTy, class _Key, class _ContainerValueTy,
-          class _RawValTy = typename __unconstref<_ValTy>::type>
-struct __can_extract_map_key
-    : integral_constant<bool, is_same<_RawValTy, _Key>::value> {};
-
-// This specialization returns __extract_key_fail_tag for non-map containers
-// because _Key == _ContainerValueTy
-template <class _ValTy, class _Key, class _RawValTy>
-struct __can_extract_map_key<_ValTy, _Key, _Key, _RawValTy>
-    : false_type {};
-
-#endif
-
-#if _LIBCPP_STD_VER > 17
-enum class endian
-{
-    little = 0xDEAD,
-    big    = 0xFACE,
-#if defined(_LIBCPP_LITTLE_ENDIAN)
-    native = little
-#elif defined(_LIBCPP_BIG_ENDIAN)
-    native = big
-#else
-    native = 0xCAFE
-#endif
-};
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER > 14
-// std::byte
-namespace std  // purposefully not versioned
-{
-template <class _Integer>
-  constexpr typename enable_if<is_integral_v<_Integer>, byte>::type &
-  operator<<=(byte& __lhs, _Integer __shift) noexcept
-  { return __lhs = __lhs << __shift; }
-
-template <class _Integer>
-  constexpr typename enable_if<is_integral_v<_Integer>, byte>::type
-  operator<< (byte  __lhs, _Integer __shift) noexcept
-  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) << __shift)); }
-
-template <class _Integer>
-  constexpr typename enable_if<is_integral_v<_Integer>, byte>::type &
-  operator>>=(byte& __lhs, _Integer __shift) noexcept
-  { return __lhs = __lhs >> __shift; }
-
-template <class _Integer>
-  constexpr typename enable_if<is_integral_v<_Integer>, byte>::type
-  operator>> (byte  __lhs, _Integer __shift) noexcept
-  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) >> __shift)); }
-
-template <class _Integer>
-  constexpr typename enable_if<is_integral_v<_Integer>, _Integer>::type
-  to_integer(byte __b) noexcept { return static_cast<_Integer>(__b); }
-
-}
-#endif
-
-#endif  // _LIBCPP_TYPE_TRAITS
diff --git a/lib/libcxx/include/typeindex b/lib/libcxx/include/typeindex
deleted file mode 100644
index 0565ca913e3..00000000000
--- a/lib/libcxx/include/typeindex
+++ /dev/null
@@ -1,103 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- typeindex ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_TYPEINDEX
-#define _LIBCPP_TYPEINDEX
-
-/*
-
-    typeindex synopsis
-
-namespace std
-{
-
-class type_index
-{
-public:
-    type_index(const type_info& rhs) noexcept;
-
-    bool operator==(const type_index& rhs) const noexcept;
-    bool operator!=(const type_index& rhs) const noexcept;
-    bool operator< (const type_index& rhs) const noexcept;
-    bool operator<=(const type_index& rhs) const noexcept;
-    bool operator> (const type_index& rhs) const noexcept;
-    bool operator>=(const type_index& rhs) const noexcept;
-
-    size_t hash_code() const noexcept;
-    const char* name() const noexcept;
-};
-
-template <>
-struct hash<type_index>
-    : public unary_function<type_index, size_t>
-{
-    size_t operator()(type_index index) const noexcept;
-};
-
-}  // std
-
-*/
-
-#include <__config>
-#include <typeinfo>
-#include <__functional_base>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-class _LIBCPP_TEMPLATE_VIS type_index
-{
-    const type_info* __t_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    type_index(const type_info& __y) _NOEXCEPT : __t_(&__y) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const type_index& __y) const _NOEXCEPT
-        {return *__t_ == *__y.__t_;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const type_index& __y) const _NOEXCEPT
-        {return *__t_ != *__y.__t_;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator< (const type_index& __y) const _NOEXCEPT
-        {return  __t_->before(*__y.__t_);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator<=(const type_index& __y) const _NOEXCEPT
-        {return !__y.__t_->before(*__t_);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator> (const type_index& __y) const _NOEXCEPT
-        {return  __y.__t_->before(*__t_);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator>=(const type_index& __y) const _NOEXCEPT
-        {return !__t_->before(*__y.__t_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t hash_code() const _NOEXCEPT {return __t_->hash_code();}
-    _LIBCPP_INLINE_VISIBILITY
-    const char* name() const _NOEXCEPT {return __t_->name();}
-};
-
-template <class _Tp> struct _LIBCPP_TEMPLATE_VIS hash;
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<type_index>
-    : public unary_function<type_index, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(type_index __index) const _NOEXCEPT
-        {return __index.hash_code();}
-};
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_TYPEINDEX
diff --git a/lib/libcxx/include/typeinfo b/lib/libcxx/include/typeinfo
deleted file mode 100644
index 8411532860b..00000000000
--- a/lib/libcxx/include/typeinfo
+++ /dev/null
@@ -1,236 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- typeinfo ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef __LIBCPP_TYPEINFO
-#define __LIBCPP_TYPEINFO
-
-/*
-
-    typeinfo synopsis
-
-namespace std {
-
-class type_info
-{
-public:
-    virtual ~type_info();
-
-    bool operator==(const type_info& rhs) const noexcept;
-    bool operator!=(const type_info& rhs) const noexcept;
-
-    bool before(const type_info& rhs) const noexcept;
-    size_t hash_code() const noexcept;
-    const char* name() const noexcept;
-
-    type_info(const type_info& rhs) = delete;
-    type_info& operator=(const type_info& rhs) = delete;
-};
-
-class bad_cast
-    : public exception
-{
-public:
-    bad_cast() noexcept;
-    bad_cast(const bad_cast&) noexcept;
-    bad_cast& operator=(const bad_cast&) noexcept;
-    virtual const char* what() const noexcept;
-};
-
-class bad_typeid
-    : public exception
-{
-public:
-    bad_typeid() noexcept;
-    bad_typeid(const bad_typeid&) noexcept;
-    bad_typeid& operator=(const bad_typeid&) noexcept;
-    virtual const char* what() const noexcept;
-};
-
-}  // std
-
-*/
-
-#include <__config>
-#include <exception>
-#include <cstddef>
-#include <cstdint>
-#ifdef _LIBCPP_NO_EXCEPTIONS
-#include <cstdlib>
-#endif
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#if defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
-#include <vcruntime_typeinfo.h>
-#else
-
-#if defined(_LIBCPP_NONUNIQUE_RTTI_BIT) && !defined(_LIBCPP_ABI_MICROSOFT)
-#   define _LIBCPP_HAS_NONUNIQUE_TYPEINFO
-#endif
-
-namespace std  // purposefully not using versioning namespace
-{
-
-class _LIBCPP_EXCEPTION_ABI type_info
-{
-    type_info& operator=(const type_info&);
-    type_info(const type_info&);
-
-#if defined(_LIBCPP_HAS_NONUNIQUE_TYPEINFO)
-    _LIBCPP_INLINE_VISIBILITY
-    int __compare_nonunique_names(const type_info &__arg) const _NOEXCEPT
-    { return __builtin_strcmp(name(), __arg.name()); }
-#endif
-
-#if defined(_LIBCPP_ABI_MICROSOFT)
-    mutable struct {
-      const char *__undecorated_name;
-      const char __decorated_name[1];
-    } __data;
-
-    int __compare(const type_info &__rhs) const _NOEXCEPT;
-#endif // _LIBCPP_ABI_MICROSOFT
-
-protected:
-#if !defined(_LIBCPP_ABI_MICROSOFT)
-#if defined(_LIBCPP_HAS_NONUNIQUE_TYPEINFO)
-    // A const char* with the non-unique RTTI bit possibly set.
-    uintptr_t __type_name;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit type_info(const char* __n)
-      : __type_name(reinterpret_cast<uintptr_t>(__n)) {}
-#else
-    const char *__type_name;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit type_info(const char* __n) : __type_name(__n) {}
-#endif
-#endif // ! _LIBCPP_ABI_MICROSOFT
-
-public:
-    _LIBCPP_AVAILABILITY_TYPEINFO_VTABLE
-    virtual ~type_info();
-
-#if defined(_LIBCPP_ABI_MICROSOFT)
-    const char *name() const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool before(const type_info& __arg) const _NOEXCEPT {
-      return __compare(__arg) < 0;
-    }
-
-    size_t hash_code() const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const type_info& __arg) const _NOEXCEPT {
-      return __compare(__arg) == 0;
-    }
-#else
-#if defined(_LIBCPP_HAS_NONUNIQUE_TYPEINFO)
-    _LIBCPP_INLINE_VISIBILITY
-    const char* name() const _NOEXCEPT
-    {
-      return reinterpret_cast<const char*>(__type_name &
-                                           ~_LIBCPP_NONUNIQUE_RTTI_BIT);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool before(const type_info& __arg) const _NOEXCEPT
-    {
-      if (!((__type_name & __arg.__type_name) & _LIBCPP_NONUNIQUE_RTTI_BIT))
-        return __type_name < __arg.__type_name;
-      return __compare_nonunique_names(__arg) < 0;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t hash_code() const _NOEXCEPT
-    {
-      if (!(__type_name & _LIBCPP_NONUNIQUE_RTTI_BIT))
-        return __type_name;
-
-      const char* __ptr = name();
-      size_t __hash = 5381;
-      while (unsigned char __c = static_cast<unsigned char>(*__ptr++))
-        __hash = (__hash * 33) ^ __c;
-      return __hash;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const type_info& __arg) const _NOEXCEPT
-    {
-      if (__type_name == __arg.__type_name)
-        return true;
-
-      if (!((__type_name & __arg.__type_name) & _LIBCPP_NONUNIQUE_RTTI_BIT))
-        return false;
-      return __compare_nonunique_names(__arg) == 0;
-    }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    const char* name() const _NOEXCEPT
-    { return __type_name; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool before(const type_info& __arg) const _NOEXCEPT
-    { return __type_name < __arg.__type_name; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t hash_code() const _NOEXCEPT
-    { return reinterpret_cast<size_t>(__type_name); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator==(const type_info& __arg) const _NOEXCEPT
-    { return __type_name == __arg.__type_name; }
-#endif
-#endif // _LIBCPP_ABI_MICROSOFT
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(const type_info& __arg) const _NOEXCEPT
-    { return !operator==(__arg); }
-};
-
-class _LIBCPP_EXCEPTION_ABI bad_cast
-    : public exception
-{
-public:
-    bad_cast() _NOEXCEPT;
-    virtual ~bad_cast() _NOEXCEPT;
-    virtual const char* what() const _NOEXCEPT;
-};
-
-class _LIBCPP_EXCEPTION_ABI bad_typeid
-    : public exception
-{
-public:
-    bad_typeid() _NOEXCEPT;
-    virtual ~bad_typeid() _NOEXCEPT;
-    virtual const char* what() const _NOEXCEPT;
-};
-
-}  // std
-
-#endif // defined(_LIBCPP_ABI_MICROSOFT) && !defined(_LIBCPP_NO_VCRUNTIME)
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
-void __throw_bad_cast()
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    throw bad_cast();
-#else
-    _VSTD::abort();
-#endif
-}
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // __LIBCPP_TYPEINFO
diff --git a/lib/libcxx/include/unordered_map b/lib/libcxx/include/unordered_map
deleted file mode 100644
index 6035b05dc61..00000000000
--- a/lib/libcxx/include/unordered_map
+++ /dev/null
@@ -1,2300 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- unordered_map -----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_UNORDERED_MAP
-#define _LIBCPP_UNORDERED_MAP
-
-/*
-
-    unordered_map synopsis
-
-#include <initializer_list>
-
-namespace std
-{
-
-template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
-          class Alloc = allocator<pair<const Key, T>>>
-class unordered_map
-{
-public:
-    // types
-    typedef Key                                                        key_type;
-    typedef T                                                          mapped_type;
-    typedef Hash                                                       hasher;
-    typedef Pred                                                       key_equal;
-    typedef Alloc                                                      allocator_type;
-    typedef pair<const key_type, mapped_type>                          value_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef /unspecified/ iterator;
-    typedef /unspecified/ const_iterator;
-    typedef /unspecified/ local_iterator;
-    typedef /unspecified/ const_local_iterator;
-
-    typedef unspecified                             node_type;            // C++17
-    typedef INSERT_RETURN_TYPE<iterator, node_type> insert_return_type;   // C++17
-
-    unordered_map()
-        noexcept(
-            is_nothrow_default_constructible<hasher>::value &&
-            is_nothrow_default_constructible<key_equal>::value &&
-            is_nothrow_default_constructible<allocator_type>::value);
-    explicit unordered_map(size_type n, const hasher& hf = hasher(),
-                           const key_equal& eql = key_equal(),
-                           const allocator_type& a = allocator_type());
-    template <class InputIterator>
-        unordered_map(InputIterator f, InputIterator l,
-                      size_type n = 0, const hasher& hf = hasher(),
-                      const key_equal& eql = key_equal(),
-                      const allocator_type& a = allocator_type());
-    explicit unordered_map(const allocator_type&);
-    unordered_map(const unordered_map&);
-    unordered_map(const unordered_map&, const Allocator&);
-    unordered_map(unordered_map&&)
-        noexcept(
-            is_nothrow_move_constructible<hasher>::value &&
-            is_nothrow_move_constructible<key_equal>::value &&
-            is_nothrow_move_constructible<allocator_type>::value);
-    unordered_map(unordered_map&&, const Allocator&);
-    unordered_map(initializer_list<value_type>, size_type n = 0,
-                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
-                  const allocator_type& a = allocator_type());
-    unordered_map(size_type n, const allocator_type& a)
-      : unordered_map(n, hasher(), key_equal(), a) {}  // C++14
-    unordered_map(size_type n, const hasher& hf, const allocator_type& a)
-      : unordered_map(n, hf, key_equal(), a) {}  // C++14
-    template <class InputIterator>
-      unordered_map(InputIterator f, InputIterator l, size_type n, const allocator_type& a)
-      : unordered_map(f, l, n, hasher(), key_equal(), a) {}  // C++14
-    template <class InputIterator>
-      unordered_map(InputIterator f, InputIterator l, size_type n, const hasher& hf, 
-        const allocator_type& a)
-      : unordered_map(f, l, n, hf, key_equal(), a) {}  // C++14
-    unordered_map(initializer_list<value_type> il, size_type n, const allocator_type& a)
-      : unordered_map(il, n, hasher(), key_equal(), a) {}  // C++14
-    unordered_map(initializer_list<value_type> il, size_type n, const hasher& hf, 
-      const allocator_type& a)
-      : unordered_map(il, n, hf, key_equal(), a) {}  // C++14
-    ~unordered_map();
-    unordered_map& operator=(const unordered_map&);
-    unordered_map& operator=(unordered_map&&)
-        noexcept(
-            allocator_type::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<allocator_type>::value &&
-            is_nothrow_move_assignable<hasher>::value &&
-            is_nothrow_move_assignable<key_equal>::value);
-    unordered_map& operator=(initializer_list<value_type>);
-
-    allocator_type get_allocator() const noexcept;
-
-    bool      empty() const noexcept;
-    size_type size() const noexcept;
-    size_type max_size() const noexcept;
-
-    iterator       begin() noexcept;
-    iterator       end() noexcept;
-    const_iterator begin()  const noexcept;
-    const_iterator end()    const noexcept;
-    const_iterator cbegin() const noexcept;
-    const_iterator cend()   const noexcept;
-
-    template <class... Args>
-        pair<iterator, bool> emplace(Args&&... args);
-    template <class... Args>
-        iterator emplace_hint(const_iterator position, Args&&... args);
-    pair<iterator, bool> insert(const value_type& obj);
-    template <class P>
-        pair<iterator, bool> insert(P&& obj);
-    iterator insert(const_iterator hint, const value_type& obj);
-    template <class P>
-        iterator insert(const_iterator hint, P&& obj);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-    void insert(initializer_list<value_type>);
-
-    node_type extract(const_iterator position);                                       // C++17
-    node_type extract(const key_type& x);                                             // C++17
-    insert_return_type insert(node_type&& nh);                                        // C++17
-    iterator           insert(const_iterator hint, node_type&& nh);                   // C++17
-
-    template <class... Args>
-        pair<iterator, bool> try_emplace(const key_type& k, Args&&... args);          // C++17
-    template <class... Args>
-        pair<iterator, bool> try_emplace(key_type&& k, Args&&... args);               // C++17
-    template <class... Args>
-        iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args); // C++17
-    template <class... Args>
-        iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args);      // C++17
-    template <class M>
-        pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj);            // C++17
-    template <class M>
-        pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj);                 // C++17
-    template <class M>
-        iterator insert_or_assign(const_iterator hint, const key_type& k, M&& obj);   // C++17
-    template <class M>
-        iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj);        // C++17
-
-    iterator erase(const_iterator position);
-    iterator erase(iterator position);  // C++14
-    size_type erase(const key_type& k);
-    iterator erase(const_iterator first, const_iterator last);
-    void clear() noexcept;
-
-    template<class H2, class P2>
-      void merge(unordered_map<Key, T, H2, P2, Allocator>& source);         // C++17
-    template<class H2, class P2>
-      void merge(unordered_map<Key, T, H2, P2, Allocator>&& source);        // C++17
-    template<class H2, class P2>
-      void merge(unordered_multimap<Key, T, H2, P2, Allocator>& source);    // C++17
-    template<class H2, class P2>
-      void merge(unordered_multimap<Key, T, H2, P2, Allocator>&& source);   // C++17
-
-    void swap(unordered_map&)
-        noexcept(
-            (!allocator_type::propagate_on_container_swap::value ||
-             __is_nothrow_swappable<allocator_type>::value) &&
-            __is_nothrow_swappable<hasher>::value &&
-            __is_nothrow_swappable<key_equal>::value);
-
-    hasher hash_function() const;
-    key_equal key_eq() const;
-
-    iterator       find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    size_type count(const key_type& k) const;
-    pair<iterator, iterator>             equal_range(const key_type& k);
-    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
-
-    mapped_type& operator[](const key_type& k);
-    mapped_type& operator[](key_type&& k);
-
-    mapped_type&       at(const key_type& k);
-    const mapped_type& at(const key_type& k) const;
-
-    size_type bucket_count() const noexcept;
-    size_type max_bucket_count() const noexcept;
-
-    size_type bucket_size(size_type n) const;
-    size_type bucket(const key_type& k) const;
-
-    local_iterator       begin(size_type n);
-    local_iterator       end(size_type n);
-    const_local_iterator begin(size_type n) const;
-    const_local_iterator end(size_type n) const;
-    const_local_iterator cbegin(size_type n) const;
-    const_local_iterator cend(size_type n) const;
-
-    float load_factor() const noexcept;
-    float max_load_factor() const noexcept;
-    void max_load_factor(float z);
-    void rehash(size_type n);
-    void reserve(size_type n);
-};
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    void swap(unordered_map<Key, T, Hash, Pred, Alloc>& x,
-              unordered_map<Key, T, Hash, Pred, Alloc>& y)
-              noexcept(noexcept(x.swap(y)));
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    bool
-    operator==(const unordered_map<Key, T, Hash, Pred, Alloc>& x,
-               const unordered_map<Key, T, Hash, Pred, Alloc>& y);
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    bool
-    operator!=(const unordered_map<Key, T, Hash, Pred, Alloc>& x,
-               const unordered_map<Key, T, Hash, Pred, Alloc>& y);
-
-template <class Key, class T, class Hash = hash<Key>, class Pred = equal_to<Key>,
-          class Alloc = allocator<pair<const Key, T>>>
-class unordered_multimap
-{
-public:
-    // types
-    typedef Key                                                        key_type;
-    typedef T                                                          mapped_type;
-    typedef Hash                                                       hasher;
-    typedef Pred                                                       key_equal;
-    typedef Alloc                                                      allocator_type;
-    typedef pair<const key_type, mapped_type>                          value_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef /unspecified/ iterator;
-    typedef /unspecified/ const_iterator;
-    typedef /unspecified/ local_iterator;
-    typedef /unspecified/ const_local_iterator;
-
-    typedef unspecified node_type;    // C++17
-
-    unordered_multimap()
-        noexcept(
-            is_nothrow_default_constructible<hasher>::value &&
-            is_nothrow_default_constructible<key_equal>::value &&
-            is_nothrow_default_constructible<allocator_type>::value);
-    explicit unordered_multimap(size_type n, const hasher& hf = hasher(),
-                           const key_equal& eql = key_equal(),
-                           const allocator_type& a = allocator_type());
-    template <class InputIterator>
-        unordered_multimap(InputIterator f, InputIterator l,
-                      size_type n = 0, const hasher& hf = hasher(),
-                      const key_equal& eql = key_equal(),
-                      const allocator_type& a = allocator_type());
-    explicit unordered_multimap(const allocator_type&);
-    unordered_multimap(const unordered_multimap&);
-    unordered_multimap(const unordered_multimap&, const Allocator&);
-    unordered_multimap(unordered_multimap&&)
-        noexcept(
-            is_nothrow_move_constructible<hasher>::value &&
-            is_nothrow_move_constructible<key_equal>::value &&
-            is_nothrow_move_constructible<allocator_type>::value);
-    unordered_multimap(unordered_multimap&&, const Allocator&);
-    unordered_multimap(initializer_list<value_type>, size_type n = 0,
-                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
-                  const allocator_type& a = allocator_type());
-    unordered_multimap(size_type n, const allocator_type& a)
-      : unordered_multimap(n, hasher(), key_equal(), a) {}  // C++14
-    unordered_multimap(size_type n, const hasher& hf, const allocator_type& a)
-      : unordered_multimap(n, hf, key_equal(), a) {}  // C++14
-    template <class InputIterator>
-      unordered_multimap(InputIterator f, InputIterator l, size_type n, const allocator_type& a)
-      : unordered_multimap(f, l, n, hasher(), key_equal(), a) {}  // C++14
-    template <class InputIterator>
-      unordered_multimap(InputIterator f, InputIterator l, size_type n, const hasher& hf, 
-        const allocator_type& a)
-      : unordered_multimap(f, l, n, hf, key_equal(), a) {}  // C++14
-    unordered_multimap(initializer_list<value_type> il, size_type n, const allocator_type& a)
-      : unordered_multimap(il, n, hasher(), key_equal(), a) {}  // C++14
-    unordered_multimap(initializer_list<value_type> il, size_type n, const hasher& hf, 
-      const allocator_type& a)
-      : unordered_multimap(il, n, hf, key_equal(), a) {}  // C++14
-    ~unordered_multimap();
-    unordered_multimap& operator=(const unordered_multimap&);
-    unordered_multimap& operator=(unordered_multimap&&)
-        noexcept(
-            allocator_type::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<allocator_type>::value &&
-            is_nothrow_move_assignable<hasher>::value &&
-            is_nothrow_move_assignable<key_equal>::value);
-    unordered_multimap& operator=(initializer_list<value_type>);
-
-    allocator_type get_allocator() const noexcept;
-
-    bool      empty() const noexcept;
-    size_type size() const noexcept;
-    size_type max_size() const noexcept;
-
-    iterator       begin() noexcept;
-    iterator       end() noexcept;
-    const_iterator begin()  const noexcept;
-    const_iterator end()    const noexcept;
-    const_iterator cbegin() const noexcept;
-    const_iterator cend()   const noexcept;
-
-    template <class... Args>
-        iterator emplace(Args&&... args);
-    template <class... Args>
-        iterator emplace_hint(const_iterator position, Args&&... args);
-    iterator insert(const value_type& obj);
-    template <class P>
-        iterator insert(P&& obj);
-    iterator insert(const_iterator hint, const value_type& obj);
-    template <class P>
-        iterator insert(const_iterator hint, P&& obj);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-    void insert(initializer_list<value_type>);
-
-    node_type extract(const_iterator position);                // C++17
-    node_type extract(const key_type& x);                      // C++17
-    iterator insert(node_type&& nh);                           // C++17
-    iterator insert(const_iterator hint, node_type&& nh);      // C++17
-
-    iterator erase(const_iterator position);
-    iterator erase(iterator position);  // C++14
-    size_type erase(const key_type& k);
-    iterator erase(const_iterator first, const_iterator last);
-    void clear() noexcept;
-
-    template<class H2, class P2>
-      void merge(unordered_multimap<Key, T, H2, P2, Allocator>& source);    // C++17
-    template<class H2, class P2>
-      void merge(unordered_multimap<Key, T, H2, P2, Allocator>&& source);   // C++17
-    template<class H2, class P2>
-      void merge(unordered_map<Key, T, H2, P2, Allocator>& source);         // C++17
-    template<class H2, class P2>
-      void merge(unordered_map<Key, T, H2, P2, Allocator>&& source);        // C++17
-
-    void swap(unordered_multimap&)
-        noexcept(
-            (!allocator_type::propagate_on_container_swap::value ||
-             __is_nothrow_swappable<allocator_type>::value) &&
-            __is_nothrow_swappable<hasher>::value &&
-            __is_nothrow_swappable<key_equal>::value);
-
-    hasher hash_function() const;
-    key_equal key_eq() const;
-
-    iterator       find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    size_type count(const key_type& k) const;
-    pair<iterator, iterator>             equal_range(const key_type& k);
-    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
-
-    size_type bucket_count() const noexcept;
-    size_type max_bucket_count() const noexcept;
-
-    size_type bucket_size(size_type n) const;
-    size_type bucket(const key_type& k) const;
-
-    local_iterator       begin(size_type n);
-    local_iterator       end(size_type n);
-    const_local_iterator begin(size_type n) const;
-    const_local_iterator end(size_type n) const;
-    const_local_iterator cbegin(size_type n) const;
-    const_local_iterator cend(size_type n) const;
-
-    float load_factor() const noexcept;
-    float max_load_factor() const noexcept;
-    void max_load_factor(float z);
-    void rehash(size_type n);
-    void reserve(size_type n);
-};
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    void swap(unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
-              unordered_multimap<Key, T, Hash, Pred, Alloc>& y)
-              noexcept(noexcept(x.swap(y)));
-
-template <class K, class T, class H, class P, class A, class Predicate>
-    void erase_if(unordered_set<K, T, H, P, A>& c, Predicate pred);       // C++20
-
-template <class K, class T, class H, class P, class A, class Predicate>
-    void erase_if(unordered_multiset<K, T, H, P, A>& c, Predicate pred);  // C++20
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    bool
-    operator==(const unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
-               const unordered_multimap<Key, T, Hash, Pred, Alloc>& y);
-
-template <class Key, class T, class Hash, class Pred, class Alloc>
-    bool
-    operator!=(const unordered_multimap<Key, T, Hash, Pred, Alloc>& x,
-               const unordered_multimap<Key, T, Hash, Pred, Alloc>& y);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__hash_table>
-#include <__node_handle>
-#include <functional>
-#include <stdexcept>
-#include <tuple>
-#include <version>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Key, class _Cp, class _Hash,
-          bool = is_empty<_Hash>::value && !__libcpp_is_final<_Hash>::value>
-class __unordered_map_hasher
-    : private _Hash
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __unordered_map_hasher()
-        _NOEXCEPT_(is_nothrow_default_constructible<_Hash>::value)
-        : _Hash() {}
-    _LIBCPP_INLINE_VISIBILITY
-    __unordered_map_hasher(const _Hash& __h)
-        _NOEXCEPT_(is_nothrow_copy_constructible<_Hash>::value)
-        : _Hash(__h) {}
-    _LIBCPP_INLINE_VISIBILITY
-    const _Hash& hash_function() const _NOEXCEPT {return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const _Cp& __x) const
-        {return static_cast<const _Hash&>(*this)(__x.__get_value().first);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const _Key& __x) const
-        {return static_cast<const _Hash&>(*this)(__x);}
-    void swap(__unordered_map_hasher&__y)
-        _NOEXCEPT_(__is_nothrow_swappable<_Hash>::value)
-    {
-        using _VSTD::swap;
-        swap(static_cast<_Hash&>(*this), static_cast<_Hash&>(__y));
-    }
-};
-
-template <class _Key, class _Cp, class _Hash>
-class __unordered_map_hasher<_Key, _Cp, _Hash, false>
-{
-    _Hash __hash_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __unordered_map_hasher()
-        _NOEXCEPT_(is_nothrow_default_constructible<_Hash>::value)
-        : __hash_() {}
-    _LIBCPP_INLINE_VISIBILITY
-    __unordered_map_hasher(const _Hash& __h)
-        _NOEXCEPT_(is_nothrow_copy_constructible<_Hash>::value)
-        : __hash_(__h) {}
-    _LIBCPP_INLINE_VISIBILITY
-    const _Hash& hash_function() const _NOEXCEPT {return __hash_;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const _Cp& __x) const
-        {return __hash_(__x.__get_value().first);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const _Key& __x) const
-        {return __hash_(__x);}
-    void swap(__unordered_map_hasher&__y)
-        _NOEXCEPT_(__is_nothrow_swappable<_Hash>::value)
-    {
-        using _VSTD::swap;
-        swap(__hash_, __y.__hash_);
-    }
-};
-
-template <class _Key, class _Cp, class _Hash, bool __b>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__unordered_map_hasher<_Key, _Cp, _Hash, __b>& __x,
-     __unordered_map_hasher<_Key, _Cp, _Hash, __b>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-template <class _Key, class _Cp, class _Pred,
-          bool = is_empty<_Pred>::value && !__libcpp_is_final<_Pred>::value>
-class __unordered_map_equal
-    : private _Pred
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __unordered_map_equal()
-        _NOEXCEPT_(is_nothrow_default_constructible<_Pred>::value)
-        : _Pred() {}
-    _LIBCPP_INLINE_VISIBILITY
-    __unordered_map_equal(const _Pred& __p)
-        _NOEXCEPT_(is_nothrow_copy_constructible<_Pred>::value)
-        : _Pred(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    const _Pred& key_eq() const _NOEXCEPT {return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Cp& __x, const _Cp& __y) const
-        {return static_cast<const _Pred&>(*this)(__x.__get_value().first, __y.__get_value().first);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Cp& __x, const _Key& __y) const
-        {return static_cast<const _Pred&>(*this)(__x.__get_value().first, __y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Key& __x, const _Cp& __y) const
-        {return static_cast<const _Pred&>(*this)(__x, __y.__get_value().first);}
-    void swap(__unordered_map_equal&__y)
-        _NOEXCEPT_(__is_nothrow_swappable<_Pred>::value)
-    {
-        using _VSTD::swap;
-        swap(static_cast<_Pred&>(*this), static_cast<_Pred&>(__y));
-    }
-};
-
-template <class _Key, class _Cp, class _Pred>
-class __unordered_map_equal<_Key, _Cp, _Pred, false>
-{
-    _Pred __pred_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    __unordered_map_equal()
-        _NOEXCEPT_(is_nothrow_default_constructible<_Pred>::value)
-        : __pred_() {}
-    _LIBCPP_INLINE_VISIBILITY
-    __unordered_map_equal(const _Pred& __p)
-        _NOEXCEPT_(is_nothrow_copy_constructible<_Pred>::value)
-        : __pred_(__p) {}
-    _LIBCPP_INLINE_VISIBILITY
-    const _Pred& key_eq() const _NOEXCEPT {return __pred_;}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Cp& __x, const _Cp& __y) const
-        {return __pred_(__x.__get_value().first, __y.__get_value().first);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Cp& __x, const _Key& __y) const
-        {return __pred_(__x.__get_value().first, __y);}
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator()(const _Key& __x, const _Cp& __y) const
-        {return __pred_(__x, __y.__get_value().first);}
-    void swap(__unordered_map_equal&__y)
-        _NOEXCEPT_(__is_nothrow_swappable<_Pred>::value)
-    {
-        using _VSTD::swap;
-        swap(__pred_, __y.__pred_);
-    }
-};
-
-template <class _Key, class _Cp, class _Pred, bool __b>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(__unordered_map_equal<_Key, _Cp, _Pred, __b>& __x,
-     __unordered_map_equal<_Key, _Cp, _Pred, __b>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-template <class _Alloc>
-class __hash_map_node_destructor
-{
-    typedef _Alloc                              allocator_type;
-    typedef allocator_traits<allocator_type>    __alloc_traits;
-
-public:
-
-    typedef typename __alloc_traits::pointer       pointer;
-private:
-
-    allocator_type& __na_;
-
-    __hash_map_node_destructor& operator=(const __hash_map_node_destructor&);
-
-public:
-    bool __first_constructed;
-    bool __second_constructed;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __hash_map_node_destructor(allocator_type& __na) _NOEXCEPT
-        : __na_(__na),
-          __first_constructed(false),
-          __second_constructed(false)
-        {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_node_destructor(__hash_node_destructor<allocator_type>&& __x)
-        _NOEXCEPT
-        : __na_(__x.__na_),
-          __first_constructed(__x.__value_constructed),
-          __second_constructed(__x.__value_constructed)
-        {
-            __x.__value_constructed = false;
-        }
-#else  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_node_destructor(const __hash_node_destructor<allocator_type>& __x)
-        : __na_(__x.__na_),
-          __first_constructed(__x.__value_constructed),
-          __second_constructed(__x.__value_constructed)
-        {
-            const_cast<bool&>(__x.__value_constructed) = false;
-        }
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator()(pointer __p) _NOEXCEPT
-    {
-        if (__second_constructed)
-            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.__get_value().second));
-        if (__first_constructed)
-            __alloc_traits::destroy(__na_, _VSTD::addressof(__p->__value_.__get_value().first));
-        if (__p)
-            __alloc_traits::deallocate(__na_, __p, 1);
-    }
-};
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Key, class _Tp>
-struct __hash_value_type
-{
-    typedef _Key                                     key_type;
-    typedef _Tp                                      mapped_type;
-    typedef pair<const key_type, mapped_type>        value_type;
-    typedef pair<key_type&, mapped_type&>            __nc_ref_pair_type;
-    typedef pair<key_type&&, mapped_type&&>          __nc_rref_pair_type;
-
-private:
-    value_type __cc;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    value_type& __get_value()
-    {
-#if _LIBCPP_STD_VER > 14
-        return *_VSTD::launder(_VSTD::addressof(__cc));
-#else
-        return __cc;
-#endif
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type& __get_value() const
-    {
-#if _LIBCPP_STD_VER > 14
-        return *_VSTD::launder(_VSTD::addressof(__cc));
-#else
-        return __cc;
-#endif
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __nc_ref_pair_type __ref()
-    {
-        value_type& __v = __get_value();
-        return __nc_ref_pair_type(const_cast<key_type&>(__v.first), __v.second);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __nc_rref_pair_type __move()
-    {
-        value_type& __v = __get_value();
-        return __nc_rref_pair_type(
-            _VSTD::move(const_cast<key_type&>(__v.first)),
-            _VSTD::move(__v.second));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_value_type& operator=(const __hash_value_type& __v)
-    {
-        __ref() = __v.__get_value();
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_value_type& operator=(__hash_value_type&& __v)
-    {
-        __ref() = __v.__move();
-        return *this;
-    }
-
-    template <class _ValueTp,
-              class = typename enable_if<
-                    __is_same_uncvref<_ValueTp, value_type>::value
-                 >::type
-             >
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_value_type& operator=(_ValueTp&& __v)
-    {
-        __ref() = _VSTD::forward<_ValueTp>(__v);
-        return *this;
-    }
-
-private:
-    __hash_value_type(const __hash_value_type& __v) = delete;
-    __hash_value_type(__hash_value_type&& __v) = delete;
-    template <class ..._Args>
-    explicit __hash_value_type(_Args&& ...__args) = delete;
-
-    ~__hash_value_type() = delete;
-};
-
-#else
-
-template <class _Key, class _Tp>
-struct __hash_value_type
-{
-    typedef _Key                                     key_type;
-    typedef _Tp                                      mapped_type;
-    typedef pair<const key_type, mapped_type>        value_type;
-
-private:
-    value_type __cc;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    value_type& __get_value() { return __cc; }
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type& __get_value() const { return __cc; }
-
-private:
-   ~__hash_value_type();
-};
-
-#endif
-
-template <class _HashIterator>
-class _LIBCPP_TEMPLATE_VIS __hash_map_iterator
-{
-    _HashIterator __i_;
-
-    typedef  __hash_node_types_from_iterator<_HashIterator> _NodeTypes;
-
-public:
-    typedef forward_iterator_tag                                 iterator_category;
-    typedef typename _NodeTypes::__map_value_type                value_type;
-    typedef typename _NodeTypes::difference_type                 difference_type;
-    typedef value_type&                                          reference;
-    typedef typename _NodeTypes::__map_value_type_pointer       pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_iterator() _NOEXCEPT {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_iterator(_HashIterator __i) _NOEXCEPT : __i_(__i) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {return __i_->__get_value();}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {return pointer_traits<pointer>::pointer_to(__i_->__get_value());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_iterator& operator++() {++__i_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_iterator operator++(int)
-    {
-        __hash_map_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const __hash_map_iterator& __x, const __hash_map_iterator& __y)
-        {return __x.__i_ == __y.__i_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const __hash_map_iterator& __x, const __hash_map_iterator& __y)
-        {return __x.__i_ != __y.__i_;}
-
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
-};
-
-template <class _HashIterator>
-class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator
-{
-    _HashIterator __i_;
-
-    typedef  __hash_node_types_from_iterator<_HashIterator> _NodeTypes;
-
-public:
-    typedef forward_iterator_tag                                 iterator_category;
-    typedef typename _NodeTypes::__map_value_type                value_type;
-    typedef typename _NodeTypes::difference_type                 difference_type;
-    typedef const value_type&                                    reference;
-    typedef typename _NodeTypes::__const_map_value_type_pointer  pointer;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_const_iterator() _NOEXCEPT {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_const_iterator(_HashIterator __i) _NOEXCEPT : __i_(__i) {}
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_const_iterator(
-            __hash_map_iterator<typename _HashIterator::__non_const_iterator> __i)
-                 _NOEXCEPT
-                : __i_(__i.__i_) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {return __i_->__get_value();}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {return pointer_traits<pointer>::pointer_to(__i_->__get_value());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_const_iterator& operator++() {++__i_; return *this;}
-    _LIBCPP_INLINE_VISIBILITY
-    __hash_map_const_iterator operator++(int)
-    {
-        __hash_map_const_iterator __t(*this);
-        ++(*this);
-        return __t;
-    }
-
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator==(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y)
-        {return __x.__i_ == __y.__i_;}
-    friend _LIBCPP_INLINE_VISIBILITY
-        bool operator!=(const __hash_map_const_iterator& __x, const __hash_map_const_iterator& __y)
-        {return __x.__i_ != __y.__i_;}
-
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
-    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
-};
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-class unordered_multimap;
-
-template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = equal_to<_Key>,
-          class _Alloc = allocator<pair<const _Key, _Tp> > >
-class _LIBCPP_TEMPLATE_VIS unordered_map
-{
-public:
-    // types
-    typedef _Key                                           key_type;
-    typedef _Tp                                            mapped_type;
-    typedef _Hash                                          hasher;
-    typedef _Pred                                          key_equal;
-    typedef _Alloc                                         allocator_type;
-    typedef pair<const key_type, mapped_type>              value_type;
-    typedef value_type&                                    reference;
-    typedef const value_type&                              const_reference;
-    static_assert((is_same<value_type, typename allocator_type::value_type>::value),
-                  "Invalid allocator::value_type");
-    static_assert(sizeof(__diagnose_unordered_container_requirements<_Key, _Hash, _Pred>(0)), "");
-
-private:
-    typedef __hash_value_type<key_type, mapped_type>                 __value_type;
-    typedef __unordered_map_hasher<key_type, __value_type, hasher>   __hasher;
-    typedef __unordered_map_equal<key_type, __value_type, key_equal> __key_equal;
-    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>,
-                                                 __value_type>::type __allocator_type;
-
-    typedef __hash_table<__value_type, __hasher,
-                         __key_equal,  __allocator_type>   __table;
-
-    __table __table_;
-
-    typedef typename __table::_NodeTypes                   _NodeTypes;
-    typedef typename __table::__node_pointer               __node_pointer;
-    typedef typename __table::__node_const_pointer         __node_const_pointer;
-    typedef typename __table::__node_traits                __node_traits;
-    typedef typename __table::__node_allocator             __node_allocator;
-    typedef typename __table::__node                       __node;
-    typedef __hash_map_node_destructor<__node_allocator>   _Dp;
-    typedef unique_ptr<__node, _Dp>                         __node_holder;
-    typedef allocator_traits<allocator_type>               __alloc_traits;
-
-    static_assert((is_same<typename __table::__container_value_type, value_type>::value), "");
-    static_assert((is_same<typename __table::__node_value_type, __value_type>::value), "");
-public:
-    typedef typename __alloc_traits::pointer         pointer;
-    typedef typename __alloc_traits::const_pointer   const_pointer;
-    typedef typename __table::size_type              size_type;
-    typedef typename __table::difference_type        difference_type;
-
-    typedef __hash_map_iterator<typename __table::iterator>       iterator;
-    typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
-    typedef __hash_map_iterator<typename __table::local_iterator> local_iterator;
-    typedef __hash_map_const_iterator<typename __table::const_local_iterator> const_local_iterator;
-
-#if _LIBCPP_STD_VER > 14
-    typedef __map_node_handle<__node, allocator_type> node_type;
-    typedef __insert_return_type<iterator, node_type> insert_return_type;
-#endif
-
-    template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS unordered_map;
-    template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
-
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_map()
-        _NOEXCEPT_(is_nothrow_default_constructible<__table>::value)
-        {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-            __get_db()->__insert_c(this);
-#endif
-        }
-    explicit unordered_map(size_type __n, const hasher& __hf = hasher(),
-                           const key_equal& __eql = key_equal());
-    unordered_map(size_type __n, const hasher& __hf,
-                  const key_equal& __eql,
-                  const allocator_type& __a);
-    template <class _InputIterator>
-        unordered_map(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        unordered_map(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf = hasher(),
-                      const key_equal& __eql = key_equal());
-    template <class _InputIterator>
-        unordered_map(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf,
-                      const key_equal& __eql,
-                      const allocator_type& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    explicit unordered_map(const allocator_type& __a);
-    unordered_map(const unordered_map& __u);
-    unordered_map(const unordered_map& __u, const allocator_type& __a);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_map(unordered_map&& __u)
-        _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
-    unordered_map(unordered_map&& __u, const allocator_type& __a);
-    unordered_map(initializer_list<value_type> __il);
-    unordered_map(initializer_list<value_type> __il, size_type __n,
-                  const hasher& __hf = hasher(), const key_equal& __eql = key_equal());
-    unordered_map(initializer_list<value_type> __il, size_type __n,
-                  const hasher& __hf, const key_equal& __eql,
-                  const allocator_type& __a);
-#endif  // _LIBCPP_CXX03_LANG
-#if _LIBCPP_STD_VER > 11
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_map(size_type __n, const allocator_type& __a)
-      : unordered_map(__n, hasher(), key_equal(), __a) {}
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_map(size_type __n, const hasher& __hf, const allocator_type& __a)
-      : unordered_map(__n, __hf, key_equal(), __a) {}
-    template <class _InputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-      unordered_map(_InputIterator __first, _InputIterator __last, size_type __n, const allocator_type& __a)
-      : unordered_map(__first, __last, __n, hasher(), key_equal(), __a) {}
-    template <class _InputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-      unordered_map(_InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, 
-        const allocator_type& __a)
-      : unordered_map(__first, __last, __n, __hf, key_equal(), __a) {}
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_map(initializer_list<value_type> __il, size_type __n, const allocator_type& __a)
-      : unordered_map(__il, __n, hasher(), key_equal(), __a) {}
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_map(initializer_list<value_type> __il, size_type __n, const hasher& __hf, 
-      const allocator_type& __a)
-      : unordered_map(__il, __n, __hf, key_equal(), __a) {}
-#endif
-    // ~unordered_map() = default;
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_map& operator=(const unordered_map& __u)
-    {
-#ifndef _LIBCPP_CXX03_LANG
-        __table_ = __u.__table_;
-#else
-        if (this != &__u) {
-            __table_.clear();
-            __table_.hash_function() = __u.__table_.hash_function();
-            __table_.key_eq() = __u.__table_.key_eq();
-            __table_.max_load_factor() = __u.__table_.max_load_factor();
-            __table_.__copy_assign_alloc(__u.__table_);
-            insert(__u.begin(), __u.end());
-        }
-#endif
-        return *this;
-    }
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_map& operator=(unordered_map&& __u)
-        _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_map& operator=(initializer_list<value_type> __il);
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT
-        {return allocator_type(__table_.__node_alloc());}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT  {return __table_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {return __table_.max_size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin() _NOEXCEPT        {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end() _NOEXCEPT          {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const _NOEXCEPT {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const _NOEXCEPT {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend()   const _NOEXCEPT {return __table_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> insert(const value_type& __x)
-        {return __table_.__insert_unique(__x);}
-
-    iterator insert(const_iterator __p, const value_type& __x) {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-            "unordered_map::insert(const_iterator, const value_type&) called with an iterator not"
-            " referring to this unordered_map");
-#else
-        ((void)__p);
-#endif
-        return insert(__x).first;
-    }
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __first, _InputIterator __last);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(initializer_list<value_type> __il)
-        {insert(__il.begin(), __il.end());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> insert(value_type&& __x)
-        {return __table_.__insert_unique(_VSTD::move(__x));}
-
-    iterator insert(const_iterator __p, value_type&& __x) {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-            "unordered_map::insert(const_iterator, const value_type&) called with an iterator not"
-            " referring to this unordered_map");
-#else
-        ((void)__p);
-#endif
-        return __table_.__insert_unique(_VSTD::move(__x)).first;
-    }
-
-    template <class _Pp,
-              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> insert(_Pp&& __x)
-            {return __table_.__insert_unique(_VSTD::forward<_Pp>(__x));}
-
-    template <class _Pp,
-              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator insert(const_iterator __p, _Pp&& __x)
-        {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-            _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-                "unordered_map::insert(const_iterator, value_type&&) called with an iterator not"
-                " referring to this unordered_map");
-#else
-          ((void)__p);
-#endif
-            return insert(_VSTD::forward<_Pp>(__x)).first;
-        }
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> emplace(_Args&&... __args) {
-        return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class... _Args>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator emplace_hint(const_iterator __p, _Args&&... __args) {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-            "unordered_map::emplace_hint(const_iterator, args...) called with an iterator not"
-            " referring to this unordered_map");
-#else
-          ((void)__p);
-#endif
-        return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...).first;
-    }
-
-#endif  // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER > 14
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> try_emplace(const key_type& __k, _Args&&... __args)
-    {
-        return __table_.__emplace_unique_key_args(__k, _VSTD::piecewise_construct,
-            _VSTD::forward_as_tuple(__k),
-            _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...));
-    }
-
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> try_emplace(key_type&& __k, _Args&&... __args)
-    {
-        return __table_.__emplace_unique_key_args(__k, _VSTD::piecewise_construct,
-            _VSTD::forward_as_tuple(_VSTD::move(__k)),
-            _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...));
-    }
-
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator try_emplace(const_iterator __h, const key_type& __k, _Args&&... __args)
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__h) == this,
-            "unordered_map::try_emplace(const_iterator, key, args...) called with an iterator not"
-            " referring to this unordered_map");
-#else
-        ((void)__h);
-#endif
-        return try_emplace(__k, _VSTD::forward<_Args>(__args)...).first;
-    }
-
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator try_emplace(const_iterator __h, key_type&& __k, _Args&&... __args)
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__h) == this,
-            "unordered_map::try_emplace(const_iterator, key, args...) called with an iterator not"
-            " referring to this unordered_map");
-#else
-        ((void)__h);
-#endif
-        return try_emplace(_VSTD::move(__k), _VSTD::forward<_Args>(__args)...).first;
-    }
-
-    template <class _Vp>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> insert_or_assign(const key_type& __k, _Vp&& __v)
-    {
-        pair<iterator, bool> __res = __table_.__emplace_unique_key_args(__k,
-            __k, _VSTD::forward<_Vp>(__v));
-        if (!__res.second) {
-            __res.first->second = _VSTD::forward<_Vp>(__v);
-        }
-        return __res;
-    }
-
-    template <class _Vp>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> insert_or_assign(key_type&& __k, _Vp&& __v)
-    {
-        pair<iterator, bool> __res = __table_.__emplace_unique_key_args(__k,
-            _VSTD::move(__k), _VSTD::forward<_Vp>(__v));
-        if (!__res.second) {
-            __res.first->second = _VSTD::forward<_Vp>(__v);
-        }
-        return __res;
-    }
-
-    template <class _Vp>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator insert_or_assign(const_iterator, const key_type& __k, _Vp&& __v)
-     {
-          // FIXME: Add debug mode checking for the iterator input
-          return insert_or_assign(__k, _VSTD::forward<_Vp>(__v)).first;
-     }
-
-    template <class _Vp>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator insert_or_assign(const_iterator, key_type&& __k, _Vp&& __v)
-     {
-        // FIXME: Add debug mode checking for the iterator input
-        return insert_or_assign(_VSTD::move(__k), _VSTD::forward<_Vp>(__v)).first;
-     }
-#endif // _LIBCPP_STD_VER > 14
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __p) {return __table_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(iterator __p)       {return __table_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __table_.__erase_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __first, const_iterator __last)
-        {return __table_.erase(__first.__i_, __last.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-        void clear() _NOEXCEPT {__table_.clear();}
-
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY
-    insert_return_type insert(node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to unordered_map::insert()");
-        return __table_.template __node_handle_insert_unique<
-            node_type, insert_return_type>(_VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __hint, node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to unordered_map::insert()");
-        return __table_.template __node_handle_insert_unique<node_type>(
-            __hint.__i_, _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(key_type const& __key)
-    {
-        return __table_.template __node_handle_extract<node_type>(__key);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(const_iterator __it)
-    {
-        return __table_.template __node_handle_extract<node_type>(
-            __it.__i_);
-    }
-
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_unique(__source.__table_);
-    }
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_unique(__source.__table_);
-    }
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_unique(__source.__table_);
-    }
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_unique(__source.__table_);
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(unordered_map& __u)
-        _NOEXCEPT_(__is_nothrow_swappable<__table>::value)
-        { __table_.swap(__u.__table_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    hasher hash_function() const
-        {return __table_.hash_function().hash_function();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_equal key_eq() const
-        {return __table_.key_eq().key_eq();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       find(const key_type& __k)       {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type count(const key_type& __k) const {return __table_.__count_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
-        {return __table_.__equal_range_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
-        {return __table_.__equal_range_unique(__k);}
-
-    mapped_type& operator[](const key_type& __k);
-#ifndef _LIBCPP_CXX03_LANG
-    mapped_type& operator[](key_type&& __k);
-#endif
-
-    mapped_type&       at(const key_type& __k);
-    const mapped_type& at(const key_type& __k) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_count() const _NOEXCEPT {return __table_.bucket_count();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_bucket_count() const _NOEXCEPT {return __table_.max_bucket_count();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_size(size_type __n) const
-        {return __table_.bucket_size(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket(const key_type& __k) const {return __table_.bucket(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator       begin(size_type __n)        {return __table_.begin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator       end(size_type __n)          {return __table_.end(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator begin(size_type __n) const  {return __table_.cbegin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator end(size_type __n) const    {return __table_.cend(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator cbegin(size_type __n) const {return __table_.cbegin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator cend(size_type __n) const   {return __table_.cend(__n);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    float load_factor() const _NOEXCEPT {return __table_.load_factor();}
-    _LIBCPP_INLINE_VISIBILITY
-    float max_load_factor() const _NOEXCEPT {return __table_.max_load_factor();}
-    _LIBCPP_INLINE_VISIBILITY
-    void max_load_factor(float __mlf) {__table_.max_load_factor(__mlf);}
-    _LIBCPP_INLINE_VISIBILITY
-    void rehash(size_type __n) {__table_.rehash(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    void reserve(size_type __n) {__table_.reserve(__n);}
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    bool __dereferenceable(const const_iterator* __i) const
-        {return __table_.__dereferenceable(&__i->__i_);}
-    bool __decrementable(const const_iterator* __i) const
-        {return __table_.__decrementable(&__i->__i_);}
-    bool __addable(const const_iterator* __i, ptrdiff_t __n) const
-        {return __table_.__addable(&__i->__i_, __n);}
-    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const
-        {return __table_.__addable(&__i->__i_, __n);}
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-private:
-
-#ifdef _LIBCPP_CXX03_LANG
-    __node_holder __construct_node_with_key(const key_type& __k);
-#endif
-};
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        size_type __n, const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        size_type __n, const hasher& __hf, const key_equal& __eql,
-        const allocator_type& __a)
-    : __table_(__hf, __eql, typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        const allocator_type& __a)
-    : __table_(typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        _InputIterator __first, _InputIterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        const unordered_map& __u)
-    : __table_(__u.__table_)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        const unordered_map& __u, const allocator_type& __a)
-    : __table_(__u.__table_, typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        unordered_map&& __u)
-    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
-    : __table_(_VSTD::move(__u.__table_))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-    __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        unordered_map&& __u, const allocator_type& __a)
-    : __table_(_VSTD::move(__u.__table_), typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__a != __u.get_allocator())
-    {
-        iterator __i = __u.begin();
-        while (__u.size() != 0) {
-            __table_.__emplace_unique(
-                __u.__table_.remove((__i++).__i_)->__value_.__move());
-        }
-    }
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    else
-        __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        initializer_list<value_type> __il)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
-        const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_map(
-        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
-        const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(unordered_map&& __u)
-    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value)
-{
-    __table_ = _VSTD::move(__u.__table_);
-    return *this;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>&
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(
-        initializer_list<value_type> __il)
-{
-    __table_.__assign_unique(__il.begin(), __il.end());
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-inline
-void
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
-                                                       _InputIterator __last)
-{
-    for (; __first != __last; ++__first)
-        __table_.__insert_unique(*__first);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-_Tp&
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](const key_type& __k)
-{
-    return __table_.__emplace_unique_key_args(__k,
-        std::piecewise_construct, std::forward_as_tuple(__k),
-                                  std::forward_as_tuple()).first->__get_value().second;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-_Tp&
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](key_type&& __k)
-{
-    return __table_.__emplace_unique_key_args(__k,
-        std::piecewise_construct, std::forward_as_tuple(std::move(__k)),
-                                  std::forward_as_tuple()).first->__get_value().second;
-}
-#else // _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__node_holder
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::__construct_node_with_key(const key_type& __k)
-{
-    __node_allocator& __na = __table_.__node_alloc();
-    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
-    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__get_value().first), __k);
-    __h.get_deleter().__first_constructed = true;
-    __node_traits::construct(__na, _VSTD::addressof(__h->__value_.__get_value().second));
-    __h.get_deleter().__second_constructed = true;
-    return _LIBCPP_EXPLICIT_MOVE(__h);  // explicitly moved for C++03
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-_Tp&
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::operator[](const key_type& __k)
-{
-    iterator __i = find(__k);
-    if (__i != end())
-        return __i->second;
-    __node_holder __h = __construct_node_with_key(__k);
-    pair<iterator, bool> __r = __table_.__node_insert_unique(__h.get());
-    __h.release();
-    return __r.first->second;
-}
-
-#endif  // _LIBCPP_CXX03_MODE
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-_Tp&
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::at(const key_type& __k)
-{
-    iterator __i = find(__k);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    if (__i == end())
-        throw out_of_range("unordered_map::at: key not found");
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __i->second;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-const _Tp&
-unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::at(const key_type& __k) const
-{
-    const_iterator __i = find(__k);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    if (__i == end())
-        throw out_of_range("unordered_map::at: key not found");
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    return __i->second;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-     unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __c, _Predicate __pred)
-{ __libcpp_erase_if_container(__c, __pred); }
-#endif
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-bool
-operator==(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-           const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    if (__x.size() != __y.size())
-        return false;
-    typedef typename unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator
-                                                                 const_iterator;
-    for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end();
-            __i != __ex; ++__i)
-    {
-        const_iterator __j = __y.find(__i->first);
-        if (__j == __ey || !(*__i == *__j))
-            return false;
-    }
-    return true;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-           const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Key, class _Tp, class _Hash = hash<_Key>, class _Pred = equal_to<_Key>,
-          class _Alloc = allocator<pair<const _Key, _Tp> > >
-class _LIBCPP_TEMPLATE_VIS unordered_multimap
-{
-public:
-    // types
-    typedef _Key                                           key_type;
-    typedef _Tp                                            mapped_type;
-    typedef _Hash                                          hasher;
-    typedef _Pred                                          key_equal;
-    typedef _Alloc                                         allocator_type;
-    typedef pair<const key_type, mapped_type>              value_type;
-    typedef value_type&                                    reference;
-    typedef const value_type&                              const_reference;
-    static_assert((is_same<value_type, typename allocator_type::value_type>::value),
-                  "Invalid allocator::value_type");
-    static_assert(sizeof(__diagnose_unordered_container_requirements<_Key, _Hash, _Pred>(0)), "");
-
-private:
-    typedef __hash_value_type<key_type, mapped_type>                 __value_type;
-    typedef __unordered_map_hasher<key_type, __value_type, hasher>   __hasher;
-    typedef __unordered_map_equal<key_type, __value_type, key_equal> __key_equal;
-    typedef typename __rebind_alloc_helper<allocator_traits<allocator_type>,
-                                                 __value_type>::type __allocator_type;
-
-    typedef __hash_table<__value_type, __hasher,
-                         __key_equal,  __allocator_type>   __table;
-
-    __table __table_;
-
-    typedef typename __table::_NodeTypes                   _NodeTypes;
-    typedef typename __table::__node_traits                __node_traits;
-    typedef typename __table::__node_allocator             __node_allocator;
-    typedef typename __table::__node                       __node;
-    typedef __hash_map_node_destructor<__node_allocator>   _Dp;
-    typedef unique_ptr<__node, _Dp>                         __node_holder;
-    typedef allocator_traits<allocator_type>               __alloc_traits;
-    static_assert((is_same<typename __node_traits::size_type,
-                          typename __alloc_traits::size_type>::value),
-                 "Allocator uses different size_type for different types");
-public:
-    typedef typename __alloc_traits::pointer         pointer;
-    typedef typename __alloc_traits::const_pointer   const_pointer;
-    typedef typename __table::size_type              size_type;
-    typedef typename __table::difference_type        difference_type;
-
-    typedef __hash_map_iterator<typename __table::iterator>       iterator;
-    typedef __hash_map_const_iterator<typename __table::const_iterator> const_iterator;
-    typedef __hash_map_iterator<typename __table::local_iterator> local_iterator;
-    typedef __hash_map_const_iterator<typename __table::const_local_iterator> const_local_iterator;
-
-#if _LIBCPP_STD_VER > 14
-    typedef __map_node_handle<__node, allocator_type> node_type;
-#endif
-
-    template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS unordered_map;
-    template <class _Key2, class _Tp2, class _Hash2, class _Pred2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
-
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multimap()
-        _NOEXCEPT_(is_nothrow_default_constructible<__table>::value)
-        {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-            __get_db()->__insert_c(this);
-#endif
-        }
-    explicit unordered_multimap(size_type __n, const hasher& __hf = hasher(),
-                                const key_equal& __eql = key_equal());
-    unordered_multimap(size_type __n, const hasher& __hf,
-                                const key_equal& __eql,
-                                const allocator_type& __a);
-    template <class _InputIterator>
-        unordered_multimap(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        unordered_multimap(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf = hasher(),
-                      const key_equal& __eql = key_equal());
-    template <class _InputIterator>
-        unordered_multimap(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf,
-                      const key_equal& __eql,
-                      const allocator_type& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    explicit unordered_multimap(const allocator_type& __a);
-    unordered_multimap(const unordered_multimap& __u);
-    unordered_multimap(const unordered_multimap& __u, const allocator_type& __a);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multimap(unordered_multimap&& __u)
-        _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
-    unordered_multimap(unordered_multimap&& __u, const allocator_type& __a);
-    unordered_multimap(initializer_list<value_type> __il);
-    unordered_multimap(initializer_list<value_type> __il, size_type __n,
-                       const hasher& __hf = hasher(),
-                       const key_equal& __eql = key_equal());
-    unordered_multimap(initializer_list<value_type> __il, size_type __n,
-                       const hasher& __hf, const key_equal& __eql,
-                       const allocator_type& __a);
-#endif  // _LIBCPP_CXX03_LANG
-#if _LIBCPP_STD_VER > 11
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multimap(size_type __n, const allocator_type& __a)
-      : unordered_multimap(__n, hasher(), key_equal(), __a) {}
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multimap(size_type __n, const hasher& __hf, const allocator_type& __a)
-      : unordered_multimap(__n, __hf, key_equal(), __a) {}
-    template <class _InputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-      unordered_multimap(_InputIterator __first, _InputIterator __last, size_type __n, const allocator_type& __a)
-      : unordered_multimap(__first, __last, __n, hasher(), key_equal(), __a) {}
-    template <class _InputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-      unordered_multimap(_InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, 
-        const allocator_type& __a)
-      : unordered_multimap(__first, __last, __n, __hf, key_equal(), __a) {}
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multimap(initializer_list<value_type> __il, size_type __n, const allocator_type& __a)
-      : unordered_multimap(__il, __n, hasher(), key_equal(), __a) {}
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multimap(initializer_list<value_type> __il, size_type __n, const hasher& __hf, 
-      const allocator_type& __a)
-      : unordered_multimap(__il, __n, __hf, key_equal(), __a) {}
-#endif
-    // ~unordered_multimap() = default;
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multimap& operator=(const unordered_multimap& __u)
-    {
-#ifndef _LIBCPP_CXX03_LANG
-        __table_ = __u.__table_;
-#else
-        if (this != &__u) {
-            __table_.clear();
-            __table_.hash_function() = __u.__table_.hash_function();
-            __table_.key_eq() = __u.__table_.key_eq();
-            __table_.max_load_factor() = __u.__table_.max_load_factor();
-            __table_.__copy_assign_alloc(__u.__table_);
-            insert(__u.begin(), __u.end());
-        }
-#endif
-        return *this;
-    }
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multimap& operator=(unordered_multimap&& __u)
-        _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multimap& operator=(initializer_list<value_type> __il);
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT
-        {return allocator_type(__table_.__node_alloc());}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT  {return __table_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {return __table_.max_size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin() _NOEXCEPT        {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end() _NOEXCEPT          {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const _NOEXCEPT {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const _NOEXCEPT {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend()   const _NOEXCEPT {return __table_.end();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const value_type& __x) {return __table_.__insert_multi(__x);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, const value_type& __x)
-        {return __table_.__insert_multi(__p.__i_, __x);}
-
-    template <class _InputIterator>
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(_InputIterator __first, _InputIterator __last);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(initializer_list<value_type> __il)
-        {insert(__il.begin(), __il.end());}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(value_type&& __x) {return __table_.__insert_multi(_VSTD::move(__x));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, value_type&& __x)
-        {return __table_.__insert_multi(__p.__i_, _VSTD::move(__x));}
-
-    template <class _Pp,
-              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(_Pp&& __x)
-        {return __table_.__insert_multi(_VSTD::forward<_Pp>(__x));}
-
-    template <class _Pp,
-              class = typename enable_if<is_constructible<value_type, _Pp>::value>::type>
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, _Pp&& __x)
-        {return __table_.__insert_multi(__p.__i_, _VSTD::forward<_Pp>(__x));}
-
-    template <class... _Args>
-    iterator emplace(_Args&&... __args) {
-        return __table_.__emplace_multi(_VSTD::forward<_Args>(__args)...);
-    }
-
-    template <class... _Args>
-    iterator emplace_hint(const_iterator __p, _Args&&... __args) {
-        return __table_.__emplace_hint_multi(__p.__i_, _VSTD::forward<_Args>(__args)...);
-    }
-#endif  // _LIBCPP_CXX03_LANG
-
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __p) {return __table_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(iterator __p)       {return __table_.erase(__p.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __table_.__erase_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __first, const_iterator __last)
-        {return __table_.erase(__first.__i_, __last.__i_);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {__table_.clear();}
-
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to unordered_multimap::insert()");
-        return __table_.template __node_handle_insert_multi<node_type>(
-            _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __hint, node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to unordered_multimap::insert()");
-        return __table_.template __node_handle_insert_multi<node_type>(
-            __hint.__i_, _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(key_type const& __key)
-    {
-        return __table_.template __node_handle_extract<node_type>(__key);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(const_iterator __it)
-    {
-        return __table_.template __node_handle_extract<node_type>(
-            __it.__i_);
-    }
-
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_multi(__source.__table_);
-    }
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_multimap<key_type, mapped_type, _H2, _P2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_multi(__source.__table_);
-    }
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_multi(__source.__table_);
-    }
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_map<key_type, mapped_type, _H2, _P2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_multi(__source.__table_);
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(unordered_multimap& __u)
-        _NOEXCEPT_(__is_nothrow_swappable<__table>::value)
-        {__table_.swap(__u.__table_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    hasher hash_function() const
-        {return __table_.hash_function().hash_function();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_equal key_eq() const
-        {return __table_.key_eq().key_eq();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       find(const key_type& __k)       {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type count(const key_type& __k) const {return __table_.__count_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
-        {return __table_.__equal_range_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
-        {return __table_.__equal_range_multi(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_count() const _NOEXCEPT {return __table_.bucket_count();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_bucket_count() const _NOEXCEPT
-        {return __table_.max_bucket_count();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_size(size_type __n) const
-        {return __table_.bucket_size(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket(const key_type& __k) const {return __table_.bucket(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator       begin(size_type __n)        {return __table_.begin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator       end(size_type __n)          {return __table_.end(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator begin(size_type __n) const  {return __table_.cbegin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator end(size_type __n) const    {return __table_.cend(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator cbegin(size_type __n) const {return __table_.cbegin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator cend(size_type __n) const   {return __table_.cend(__n);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    float load_factor() const _NOEXCEPT {return __table_.load_factor();}
-    _LIBCPP_INLINE_VISIBILITY
-    float max_load_factor() const _NOEXCEPT {return __table_.max_load_factor();}
-    _LIBCPP_INLINE_VISIBILITY
-    void max_load_factor(float __mlf) {__table_.max_load_factor(__mlf);}
-    _LIBCPP_INLINE_VISIBILITY
-    void rehash(size_type __n) {__table_.rehash(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    void reserve(size_type __n) {__table_.reserve(__n);}
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    bool __dereferenceable(const const_iterator* __i) const
-        {return __table_.__dereferenceable(&__i->__i_);}
-    bool __decrementable(const const_iterator* __i) const
-        {return __table_.__decrementable(&__i->__i_);}
-    bool __addable(const const_iterator* __i, ptrdiff_t __n) const
-        {return __table_.__addable(&__i->__i_, __n);}
-    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const
-        {return __table_.__addable(&__i->__i_, __n);}
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-
-};
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        size_type __n, const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        size_type __n, const hasher& __hf, const key_equal& __eql,
-        const allocator_type& __a)
-    : __table_(__hf, __eql, typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        _InputIterator __first, _InputIterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        const allocator_type& __a)
-    : __table_(typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        const unordered_multimap& __u)
-    : __table_(__u.__table_)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        const unordered_multimap& __u, const allocator_type& __a)
-    : __table_(__u.__table_, typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        unordered_multimap&& __u)
-    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
-    : __table_(_VSTD::move(__u.__table_))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-    __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        unordered_multimap&& __u, const allocator_type& __a)
-    : __table_(_VSTD::move(__u.__table_), typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__a != __u.get_allocator())
-    {
-        iterator __i = __u.begin();
-        while (__u.size() != 0)
-        {
-            __table_.__insert_multi(
-                __u.__table_.remove((__i++).__i_)->__value_.__move());
-        }
-    }
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    else
-        __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        initializer_list<value_type> __il)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
-        const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::unordered_multimap(
-        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
-        const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, typename __table::allocator_type(__a))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>&
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(unordered_multimap&& __u)
-    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value)
-{
-    __table_ = _VSTD::move(__u.__table_);
-    return *this;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>&
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::operator=(
-        initializer_list<value_type> __il)
-{
-    __table_.__assign_multi(__il.begin(), __il.end());
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-inline
-void
-unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
-                                                            _InputIterator __last)
-{
-    for (; __first != __last; ++__first)
-        __table_.__insert_multi(*__first);
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-     unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __c, _Predicate __pred)
-{ __libcpp_erase_if_container(__c, __pred); }
-#endif
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-bool
-operator==(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-           const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    if (__x.size() != __y.size())
-        return false;
-    typedef typename unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>::const_iterator
-                                                                 const_iterator;
-    typedef pair<const_iterator, const_iterator> _EqRng;
-    for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
-    {
-        _EqRng __xeq = __x.equal_range(__i->first);
-        _EqRng __yeq = __y.equal_range(__i->first);
-        if (_VSTD::distance(__xeq.first, __xeq.second) !=
-            _VSTD::distance(__yeq.first, __yeq.second) ||
-                  !_VSTD::is_permutation(__xeq.first, __xeq.second, __yeq.first))
-            return false;
-        __i = __xeq.second;
-    }
-    return true;
-}
-
-template <class _Key, class _Tp, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x,
-           const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_UNORDERED_MAP
diff --git a/lib/libcxx/include/unordered_set b/lib/libcxx/include/unordered_set
deleted file mode 100644
index b4e61da89ee..00000000000
--- a/lib/libcxx/include/unordered_set
+++ /dev/null
@@ -1,1555 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- unordered_set -----------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_UNORDERED_SET
-#define _LIBCPP_UNORDERED_SET
-
-/*
-
-    unordered_set synopsis
-
-#include <initializer_list>
-
-namespace std
-{
-
-template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
-          class Alloc = allocator<Value>>
-class unordered_set
-{
-public:
-    // types
-    typedef Value                                                      key_type;
-    typedef key_type                                                   value_type;
-    typedef Hash                                                       hasher;
-    typedef Pred                                                       key_equal;
-    typedef Alloc                                                      allocator_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef /unspecified/ iterator;
-    typedef /unspecified/ const_iterator;
-    typedef /unspecified/ local_iterator;
-    typedef /unspecified/ const_local_iterator;
-
-    typedef unspecified node_type unspecified;                            // C++17
-    typedef INSERT_RETURN_TYPE<iterator, node_type> insert_return_type;   // C++17
-
-    unordered_set()
-        noexcept(
-            is_nothrow_default_constructible<hasher>::value &&
-            is_nothrow_default_constructible<key_equal>::value &&
-            is_nothrow_default_constructible<allocator_type>::value);
-    explicit unordered_set(size_type n, const hasher& hf = hasher(),
-                           const key_equal& eql = key_equal(),
-                           const allocator_type& a = allocator_type());
-    template <class InputIterator>
-        unordered_set(InputIterator f, InputIterator l,
-                      size_type n = 0, const hasher& hf = hasher(),
-                      const key_equal& eql = key_equal(),
-                      const allocator_type& a = allocator_type());
-    explicit unordered_set(const allocator_type&);
-    unordered_set(const unordered_set&);
-    unordered_set(const unordered_set&, const Allocator&);
-    unordered_set(unordered_set&&)
-        noexcept(
-            is_nothrow_move_constructible<hasher>::value &&
-            is_nothrow_move_constructible<key_equal>::value &&
-            is_nothrow_move_constructible<allocator_type>::value);
-    unordered_set(unordered_set&&, const Allocator&);
-    unordered_set(initializer_list<value_type>, size_type n = 0,
-                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
-                  const allocator_type& a = allocator_type());
-    unordered_set(size_type n, const allocator_type& a); // C++14
-    unordered_set(size_type n, const hasher& hf, const allocator_type& a); // C++14
-    template <class InputIterator>
-      unordered_set(InputIterator f, InputIterator l, size_type n, const allocator_type& a); // C++14
-    template <class InputIterator>
-      unordered_set(InputIterator f, InputIterator l, size_type n, 
-                    const hasher& hf,  const allocator_type& a); // C++14
-    unordered_set(initializer_list<value_type> il, size_type n, const allocator_type& a); // C++14
-    unordered_set(initializer_list<value_type> il, size_type n,
-                  const hasher& hf,  const allocator_type& a); // C++14
-    ~unordered_set();
-    unordered_set& operator=(const unordered_set&);
-    unordered_set& operator=(unordered_set&&)
-        noexcept(
-            allocator_type::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<allocator_type>::value &&
-            is_nothrow_move_assignable<hasher>::value &&
-            is_nothrow_move_assignable<key_equal>::value);
-    unordered_set& operator=(initializer_list<value_type>);
-
-    allocator_type get_allocator() const noexcept;
-
-    bool      empty() const noexcept;
-    size_type size() const noexcept;
-    size_type max_size() const noexcept;
-
-    iterator       begin() noexcept;
-    iterator       end() noexcept;
-    const_iterator begin()  const noexcept;
-    const_iterator end()    const noexcept;
-    const_iterator cbegin() const noexcept;
-    const_iterator cend()   const noexcept;
-
-    template <class... Args>
-        pair<iterator, bool> emplace(Args&&... args);
-    template <class... Args>
-        iterator emplace_hint(const_iterator position, Args&&... args);
-    pair<iterator, bool> insert(const value_type& obj);
-    pair<iterator, bool> insert(value_type&& obj);
-    iterator insert(const_iterator hint, const value_type& obj);
-    iterator insert(const_iterator hint, value_type&& obj);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-    void insert(initializer_list<value_type>);
-
-    node_type extract(const_iterator position);                       // C++17
-    node_type extract(const key_type& x);                             // C++17
-    insert_return_type insert(node_type&& nh);                        // C++17
-    iterator           insert(const_iterator hint, node_type&& nh);   // C++17
-
-    iterator erase(const_iterator position);
-    iterator erase(iterator position);  // C++14
-    size_type erase(const key_type& k);
-    iterator erase(const_iterator first, const_iterator last);
-    void clear() noexcept;
-
-    template<class H2, class P2>
-      void merge(unordered_set<Key, H2, P2, Allocator>& source);         // C++17
-    template<class H2, class P2>
-      void merge(unordered_set<Key, H2, P2, Allocator>&& source);        // C++17
-    template<class H2, class P2>
-      void merge(unordered_multiset<Key, H2, P2, Allocator>& source);    // C++17
-    template<class H2, class P2>
-      void merge(unordered_multiset<Key, H2, P2, Allocator>&& source);   // C++17
-
-    void swap(unordered_set&)
-       noexcept(allocator_traits<Allocator>::is_always_equal::value &&
-                 noexcept(swap(declval<hasher&>(), declval<hasher&>())) &&
-                 noexcept(swap(declval<key_equal&>(), declval<key_equal&>()))); // C++17
-
-    hasher hash_function() const;
-    key_equal key_eq() const;
-
-    iterator       find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    size_type count(const key_type& k) const;
-    pair<iterator, iterator>             equal_range(const key_type& k);
-    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
-
-    size_type bucket_count() const noexcept;
-    size_type max_bucket_count() const noexcept;
-
-    size_type bucket_size(size_type n) const;
-    size_type bucket(const key_type& k) const;
-
-    local_iterator       begin(size_type n);
-    local_iterator       end(size_type n);
-    const_local_iterator begin(size_type n) const;
-    const_local_iterator end(size_type n) const;
-    const_local_iterator cbegin(size_type n) const;
-    const_local_iterator cend(size_type n) const;
-
-    float load_factor() const noexcept;
-    float max_load_factor() const noexcept;
-    void max_load_factor(float z);
-    void rehash(size_type n);
-    void reserve(size_type n);
-};
-
-template <class Value, class Hash, class Pred, class Alloc>
-    void swap(unordered_set<Value, Hash, Pred, Alloc>& x,
-              unordered_set<Value, Hash, Pred, Alloc>& y)
-              noexcept(noexcept(x.swap(y)));
-
-template <class Value, class Hash, class Pred, class Alloc>
-    bool
-    operator==(const unordered_set<Value, Hash, Pred, Alloc>& x,
-               const unordered_set<Value, Hash, Pred, Alloc>& y);
-
-template <class Value, class Hash, class Pred, class Alloc>
-    bool
-    operator!=(const unordered_set<Value, Hash, Pred, Alloc>& x,
-               const unordered_set<Value, Hash, Pred, Alloc>& y);
-
-template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
-          class Alloc = allocator<Value>>
-class unordered_multiset
-{
-public:
-    // types
-    typedef Value                                                      key_type;
-    typedef key_type                                                   value_type;
-    typedef Hash                                                       hasher;
-    typedef Pred                                                       key_equal;
-    typedef Alloc                                                      allocator_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    typedef typename allocator_traits<allocator_type>::pointer         pointer;
-    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
-    typedef typename allocator_traits<allocator_type>::size_type       size_type;
-    typedef typename allocator_traits<allocator_type>::difference_type difference_type;
-
-    typedef /unspecified/ iterator;
-    typedef /unspecified/ const_iterator;
-    typedef /unspecified/ local_iterator;
-    typedef /unspecified/ const_local_iterator;
-
-    typedef unspecified node_type unspecified;   // C++17
-
-    unordered_multiset()
-        noexcept(
-            is_nothrow_default_constructible<hasher>::value &&
-            is_nothrow_default_constructible<key_equal>::value &&
-            is_nothrow_default_constructible<allocator_type>::value);
-    explicit unordered_multiset(size_type n, const hasher& hf = hasher(),
-                           const key_equal& eql = key_equal(),
-                           const allocator_type& a = allocator_type());
-    template <class InputIterator>
-        unordered_multiset(InputIterator f, InputIterator l,
-                      size_type n = 0, const hasher& hf = hasher(),
-                      const key_equal& eql = key_equal(),
-                      const allocator_type& a = allocator_type());
-    explicit unordered_multiset(const allocator_type&);
-    unordered_multiset(const unordered_multiset&);
-    unordered_multiset(const unordered_multiset&, const Allocator&);
-    unordered_multiset(unordered_multiset&&)
-        noexcept(
-            is_nothrow_move_constructible<hasher>::value &&
-            is_nothrow_move_constructible<key_equal>::value &&
-            is_nothrow_move_constructible<allocator_type>::value);
-    unordered_multiset(unordered_multiset&&, const Allocator&);
-    unordered_multiset(initializer_list<value_type>, size_type n = /see below/,
-                  const hasher& hf = hasher(), const key_equal& eql = key_equal(),
-                  const allocator_type& a = allocator_type());
-    unordered_multiset(size_type n, const allocator_type& a); // C++14
-    unordered_multiset(size_type n, const hasher& hf, const allocator_type& a); // C++14
-    template <class InputIterator>
-      unordered_multiset(InputIterator f, InputIterator l, size_type n, const allocator_type& a); // C++14
-    template <class InputIterator>
-      unordered_multiset(InputIterator f, InputIterator l, size_type n,
-                         const hasher& hf, const allocator_type& a); // C++14
-    unordered_multiset(initializer_list<value_type> il, size_type n, const allocator_type& a); // C++14
-    unordered_multiset(initializer_list<value_type> il, size_type n, 
-                       const hasher& hf,  const allocator_type& a); // C++14
-    ~unordered_multiset();
-    unordered_multiset& operator=(const unordered_multiset&);
-    unordered_multiset& operator=(unordered_multiset&&)
-        noexcept(
-            allocator_type::propagate_on_container_move_assignment::value &&
-            is_nothrow_move_assignable<allocator_type>::value &&
-            is_nothrow_move_assignable<hasher>::value &&
-            is_nothrow_move_assignable<key_equal>::value);
-    unordered_multiset& operator=(initializer_list<value_type>);
-
-    allocator_type get_allocator() const noexcept;
-
-    bool      empty() const noexcept;
-    size_type size() const noexcept;
-    size_type max_size() const noexcept;
-
-    iterator       begin() noexcept;
-    iterator       end() noexcept;
-    const_iterator begin()  const noexcept;
-    const_iterator end()    const noexcept;
-    const_iterator cbegin() const noexcept;
-    const_iterator cend()   const noexcept;
-
-    template <class... Args>
-        iterator emplace(Args&&... args);
-    template <class... Args>
-        iterator emplace_hint(const_iterator position, Args&&... args);
-    iterator insert(const value_type& obj);
-    iterator insert(value_type&& obj);
-    iterator insert(const_iterator hint, const value_type& obj);
-    iterator insert(const_iterator hint, value_type&& obj);
-    template <class InputIterator>
-        void insert(InputIterator first, InputIterator last);
-    void insert(initializer_list<value_type>);
-
-    node_type extract(const_iterator position);             // C++17
-    node_type extract(const key_type& x);                   // C++17
-    iterator insert(node_type&& nh);                        // C++17
-    iterator insert(const_iterator hint, node_type&& nh);   // C++17
-
-    iterator erase(const_iterator position);
-    iterator erase(iterator position);  // C++14
-    size_type erase(const key_type& k);
-    iterator erase(const_iterator first, const_iterator last);
-    void clear() noexcept;
-
-    template<class H2, class P2>
-      void merge(unordered_multiset<Key, H2, P2, Allocator>& source);    // C++17
-    template<class H2, class P2>
-      void merge(unordered_multiset<Key, H2, P2, Allocator>&& source);   // C++17
-    template<class H2, class P2>
-      void merge(unordered_set<Key, H2, P2, Allocator>& source);         // C++17
-    template<class H2, class P2>
-      void merge(unordered_set<Key, H2, P2, Allocator>&& source);        // C++17
-
-    void swap(unordered_multiset&)
-       noexcept(allocator_traits<Allocator>::is_always_equal::value &&
-                 noexcept(swap(declval<hasher&>(), declval<hasher&>())) &&
-                 noexcept(swap(declval<key_equal&>(), declval<key_equal&>()))); // C++17
-
-    hasher hash_function() const;
-    key_equal key_eq() const;
-
-    iterator       find(const key_type& k);
-    const_iterator find(const key_type& k) const;
-    size_type count(const key_type& k) const;
-    pair<iterator, iterator>             equal_range(const key_type& k);
-    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
-
-    size_type bucket_count() const noexcept;
-    size_type max_bucket_count() const noexcept;
-
-    size_type bucket_size(size_type n) const;
-    size_type bucket(const key_type& k) const;
-
-    local_iterator       begin(size_type n);
-    local_iterator       end(size_type n);
-    const_local_iterator begin(size_type n) const;
-    const_local_iterator end(size_type n) const;
-    const_local_iterator cbegin(size_type n) const;
-    const_local_iterator cend(size_type n) const;
-
-    float load_factor() const noexcept;
-    float max_load_factor() const noexcept;
-    void max_load_factor(float z);
-    void rehash(size_type n);
-    void reserve(size_type n);
-};
-
-template <class Value, class Hash, class Pred, class Alloc>
-    void swap(unordered_multiset<Value, Hash, Pred, Alloc>& x,
-              unordered_multiset<Value, Hash, Pred, Alloc>& y)
-              noexcept(noexcept(x.swap(y)));
-
-template <class K, class T, class H, class P, class A, class Predicate>
-    void erase_if(unordered_set<K, T, H, P, A>& c, Predicate pred);       // C++20
-
-template <class K, class T, class H, class P, class A, class Predicate>
-    void erase_if(unordered_multiset<K, T, H, P, A>& c, Predicate pred);  // C++20
-
-
-template <class Value, class Hash, class Pred, class Alloc>
-    bool
-    operator==(const unordered_multiset<Value, Hash, Pred, Alloc>& x,
-               const unordered_multiset<Value, Hash, Pred, Alloc>& y);
-
-template <class Value, class Hash, class Pred, class Alloc>
-    bool
-    operator!=(const unordered_multiset<Value, Hash, Pred, Alloc>& x,
-               const unordered_multiset<Value, Hash, Pred, Alloc>& y);
-}  // std
-
-*/
-
-#include <__config>
-#include <__hash_table>
-#include <__node_handle>
-#include <functional>
-#include <version>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-class unordered_multiset;
-
-template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
-          class _Alloc = allocator<_Value> >
-class _LIBCPP_TEMPLATE_VIS unordered_set
-{
-public:
-    // types
-    typedef _Value                                                     key_type;
-    typedef key_type                                                   value_type;
-    typedef _Hash                                                      hasher;
-    typedef _Pred                                                      key_equal;
-    typedef _Alloc                                                     allocator_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    static_assert((is_same<value_type, typename allocator_type::value_type>::value),
-                  "Invalid allocator::value_type");
-    static_assert(sizeof(__diagnose_unordered_container_requirements<_Value, _Hash, _Pred>(0)), "");
-
-private:
-    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
-
-    __table __table_;
-
-public:
-    typedef typename __table::pointer         pointer;
-    typedef typename __table::const_pointer   const_pointer;
-    typedef typename __table::size_type       size_type;
-    typedef typename __table::difference_type difference_type;
-
-    typedef typename __table::const_iterator       iterator;
-    typedef typename __table::const_iterator       const_iterator;
-    typedef typename __table::const_local_iterator local_iterator;
-    typedef typename __table::const_local_iterator const_local_iterator;
-
-#if _LIBCPP_STD_VER > 14
-    typedef __set_node_handle<typename __table::__node, allocator_type> node_type;
-    typedef __insert_return_type<iterator, node_type> insert_return_type;
-#endif
-
-    template <class _Value2, class _Hash2, class _Pred2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS unordered_set;
-    template <class _Value2, class _Hash2, class _Pred2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS unordered_multiset;
-
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_set()
-        _NOEXCEPT_(is_nothrow_default_constructible<__table>::value)
-        {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-            __get_db()->__insert_c(this);
-#endif
-        }
-    explicit unordered_set(size_type __n, const hasher& __hf = hasher(),
-                           const key_equal& __eql = key_equal());
-#if _LIBCPP_STD_VER > 11
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_set(size_type __n, const allocator_type& __a)
-        : unordered_set(__n, hasher(), key_equal(), __a) {}
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_set(size_type __n, const hasher& __hf, const allocator_type& __a)
-        : unordered_set(__n, __hf, key_equal(), __a) {}
-#endif
-    unordered_set(size_type __n, const hasher& __hf, const key_equal& __eql,
-                  const allocator_type& __a);
-    template <class _InputIterator>
-        unordered_set(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        unordered_set(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf = hasher(),
-                      const key_equal& __eql = key_equal());
-    template <class _InputIterator>
-        unordered_set(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf, const key_equal& __eql,
-                      const allocator_type& __a);
-#if _LIBCPP_STD_VER > 11
-    template <class _InputIterator>
-    inline _LIBCPP_INLINE_VISIBILITY
-        unordered_set(_InputIterator __first, _InputIterator __last, 
-                    size_type __n, const allocator_type& __a)
-            : unordered_set(__first, __last, __n, hasher(), key_equal(), __a) {}
-    template <class _InputIterator>
-        unordered_set(_InputIterator __first, _InputIterator __last, 
-                      size_type __n, const hasher& __hf, const allocator_type& __a)
-            : unordered_set(__first, __last, __n, __hf, key_equal(), __a) {}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    explicit unordered_set(const allocator_type& __a);
-    unordered_set(const unordered_set& __u);
-    unordered_set(const unordered_set& __u, const allocator_type& __a);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_set(unordered_set&& __u)
-        _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
-    unordered_set(unordered_set&& __u, const allocator_type& __a);
-    unordered_set(initializer_list<value_type> __il);
-    unordered_set(initializer_list<value_type> __il, size_type __n,
-                  const hasher& __hf = hasher(),
-                  const key_equal& __eql = key_equal());
-    unordered_set(initializer_list<value_type> __il, size_type __n,
-                  const hasher& __hf, const key_equal& __eql,
-                  const allocator_type& __a);
-#if _LIBCPP_STD_VER > 11
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_set(initializer_list<value_type> __il, size_type __n,
-                                                      const allocator_type& __a)
-        : unordered_set(__il, __n, hasher(), key_equal(), __a) {}
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_set(initializer_list<value_type> __il, size_type __n, 
-                                  const hasher& __hf, const allocator_type& __a)
-        : unordered_set(__il, __n, __hf, key_equal(), __a) {}
-#endif
-#endif  // _LIBCPP_CXX03_LANG
-    // ~unordered_set() = default;
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_set& operator=(const unordered_set& __u)
-    {
-        __table_ = __u.__table_;
-        return *this;
-    }
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_set& operator=(unordered_set&& __u)
-        _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_set& operator=(initializer_list<value_type> __il);
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT
-        {return allocator_type(__table_.__node_alloc());}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT  {return __table_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {return __table_.max_size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin() _NOEXCEPT        {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end() _NOEXCEPT          {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const _NOEXCEPT {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const _NOEXCEPT {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend()   const _NOEXCEPT {return __table_.end();}
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        pair<iterator, bool> emplace(_Args&&... __args)
-            {return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...);}
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        iterator emplace_hint(const_iterator __p, _Args&&... __args)
-        {
-            _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-                "unordered_set::emplace_hint(const_iterator, args...) called with an iterator not"
-                " referring to this unordered_set");
-            return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...).first;
-        }
-#else
-        iterator emplace_hint(const_iterator, _Args&&... __args)
-            {return __table_.__emplace_unique(_VSTD::forward<_Args>(__args)...).first;}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> insert(value_type&& __x)
-        {return __table_.__insert_unique(_VSTD::move(__x));}
-    _LIBCPP_INLINE_VISIBILITY
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    iterator insert(const_iterator __p, value_type&& __x)
-        {
-            _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-                "unordered_set::insert(const_iterator, value_type&&) called with an iterator not"
-                " referring to this unordered_set");
-            return insert(_VSTD::move(__x)).first;
-        }
-#else
-    iterator insert(const_iterator, value_type&& __x)
-        {return insert(_VSTD::move(__x)).first;}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(initializer_list<value_type> __il)
-        {insert(__il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, bool> insert(const value_type& __x)
-        {return __table_.__insert_unique(__x);}
-
-    _LIBCPP_INLINE_VISIBILITY
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    iterator insert(const_iterator __p, const value_type& __x)
-        {
-            _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
-                "unordered_set::insert(const_iterator, const value_type&) called with an iterator not"
-                " referring to this unordered_set");
-            return insert(__x).first;
-        }
-#else
-    iterator insert(const_iterator, const value_type& __x)
-        {return insert(__x).first;}
-#endif
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __first, _InputIterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __p) {return __table_.erase(__p);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __table_.__erase_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __first, const_iterator __last)
-        {return __table_.erase(__first, __last);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {__table_.clear();}
-
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY
-    insert_return_type insert(node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to unordered_set::insert()");
-        return __table_.template __node_handle_insert_unique<
-            node_type, insert_return_type>(_VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __h, node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to unordered_set::insert()");
-        return __table_.template __node_handle_insert_unique<node_type>(
-            __h, _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(key_type const& __key)
-    {
-        return __table_.template __node_handle_extract<node_type>(__key);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(const_iterator __it)
-    {
-        return __table_.template __node_handle_extract<node_type>(__it);
-    }
-
-    template<class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_set<key_type, _H2, _P2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __table_.__node_handle_merge_unique(__source.__table_);
-    }
-    template<class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_set<key_type, _H2, _P2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __table_.__node_handle_merge_unique(__source.__table_);
-    }
-    template<class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_multiset<key_type, _H2, _P2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __table_.__node_handle_merge_unique(__source.__table_);
-    }
-    template<class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_multiset<key_type, _H2, _P2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        __table_.__node_handle_merge_unique(__source.__table_);
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(unordered_set& __u)
-        _NOEXCEPT_(__is_nothrow_swappable<__table>::value)
-        {__table_.swap(__u.__table_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    hasher hash_function() const {return __table_.hash_function();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_equal key_eq() const {return __table_.key_eq();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       find(const key_type& __k)       {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type count(const key_type& __k) const {return __table_.__count_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
-        {return __table_.__equal_range_unique(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
-        {return __table_.__equal_range_unique(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_count() const _NOEXCEPT {return __table_.bucket_count();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_bucket_count() const _NOEXCEPT {return __table_.max_bucket_count();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_size(size_type __n) const {return __table_.bucket_size(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket(const key_type& __k) const {return __table_.bucket(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator       begin(size_type __n)        {return __table_.begin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator       end(size_type __n)          {return __table_.end(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator begin(size_type __n) const  {return __table_.cbegin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator end(size_type __n) const    {return __table_.cend(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator cbegin(size_type __n) const {return __table_.cbegin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator cend(size_type __n) const   {return __table_.cend(__n);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    float load_factor() const _NOEXCEPT {return __table_.load_factor();}
-    _LIBCPP_INLINE_VISIBILITY
-    float max_load_factor() const _NOEXCEPT {return __table_.max_load_factor();}
-    _LIBCPP_INLINE_VISIBILITY
-    void max_load_factor(float __mlf) {__table_.max_load_factor(__mlf);}
-    _LIBCPP_INLINE_VISIBILITY
-    void rehash(size_type __n) {__table_.rehash(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    void reserve(size_type __n) {__table_.reserve(__n);}
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    bool __dereferenceable(const const_iterator* __i) const
-        {return __table_.__dereferenceable(__i);}
-    bool __decrementable(const const_iterator* __i) const
-        {return __table_.__decrementable(__i);}
-    bool __addable(const const_iterator* __i, ptrdiff_t __n) const
-        {return __table_.__addable(__i, __n);}
-    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const
-        {return __table_.__addable(__i, __n);}
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-};
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        _InputIterator __first, _InputIterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        const allocator_type& __a)
-    : __table_(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        const unordered_set& __u)
-    : __table_(__u.__table_)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        const unordered_set& __u, const allocator_type& __a)
-    : __table_(__u.__table_, __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        unordered_set&& __u)
-    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
-    : __table_(_VSTD::move(__u.__table_))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-    __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        unordered_set&& __u, const allocator_type& __a)
-    : __table_(_VSTD::move(__u.__table_), __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__a != __u.get_allocator())
-    {
-        iterator __i = __u.begin();
-        while (__u.size() != 0)
-            __table_.__insert_unique(_VSTD::move(__u.__table_.remove(__i++)->__value_));
-    }
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    else
-        __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        initializer_list<value_type> __il)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
-        const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_set<_Value, _Hash, _Pred, _Alloc>::unordered_set(
-        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
-        const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_set<_Value, _Hash, _Pred, _Alloc>&
-unordered_set<_Value, _Hash, _Pred, _Alloc>::operator=(unordered_set&& __u)
-    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value)
-{
-    __table_ = _VSTD::move(__u.__table_);
-    return *this;
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_set<_Value, _Hash, _Pred, _Alloc>&
-unordered_set<_Value, _Hash, _Pred, _Alloc>::operator=(
-        initializer_list<value_type> __il)
-{
-    __table_.__assign_unique(__il.begin(), __il.end());
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-inline
-void
-unordered_set<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
-                                                    _InputIterator __last)
-{
-    for (; __first != __last; ++__first)
-        __table_.__insert_unique(*__first);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(unordered_set<_Value, _Hash, _Pred, _Alloc>& __x,
-     unordered_set<_Value, _Hash, _Pred, _Alloc>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Value, class _Hash, class _Pred, class _Alloc, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(unordered_set<_Value, _Hash, _Pred, _Alloc>& __c, _Predicate __pred)
-{ __libcpp_erase_if_container(__c, __pred); }
-#endif
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-bool
-operator==(const unordered_set<_Value, _Hash, _Pred, _Alloc>& __x,
-           const unordered_set<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    if (__x.size() != __y.size())
-        return false;
-    typedef typename unordered_set<_Value, _Hash, _Pred, _Alloc>::const_iterator
-                                                                 const_iterator;
-    for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end();
-            __i != __ex; ++__i)
-    {
-        const_iterator __j = __y.find(*__i);
-        if (__j == __ey || !(*__i == *__j))
-            return false;
-    }
-    return true;
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const unordered_set<_Value, _Hash, _Pred, _Alloc>& __x,
-           const unordered_set<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Value, class _Hash = hash<_Value>, class _Pred = equal_to<_Value>,
-          class _Alloc = allocator<_Value> >
-class _LIBCPP_TEMPLATE_VIS unordered_multiset
-{
-public:
-    // types
-    typedef _Value                                                     key_type;
-    typedef key_type                                                   value_type;
-    typedef _Hash                                                      hasher;
-    typedef _Pred                                                      key_equal;
-    typedef _Alloc                                                     allocator_type;
-    typedef value_type&                                                reference;
-    typedef const value_type&                                          const_reference;
-    static_assert((is_same<value_type, typename allocator_type::value_type>::value),
-                  "Invalid allocator::value_type");
-    static_assert(sizeof(__diagnose_unordered_container_requirements<_Value, _Hash, _Pred>(0)), "");
-
-private:
-    typedef __hash_table<value_type, hasher, key_equal, allocator_type> __table;
-
-    __table __table_;
-
-public:
-    typedef typename __table::pointer         pointer;
-    typedef typename __table::const_pointer   const_pointer;
-    typedef typename __table::size_type       size_type;
-    typedef typename __table::difference_type difference_type;
-
-    typedef typename __table::const_iterator       iterator;
-    typedef typename __table::const_iterator       const_iterator;
-    typedef typename __table::const_local_iterator local_iterator;
-    typedef typename __table::const_local_iterator const_local_iterator;
-
-#if _LIBCPP_STD_VER > 14
-    typedef __set_node_handle<typename __table::__node, allocator_type> node_type;
-#endif
-
-    template <class _Value2, class _Hash2, class _Pred2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS unordered_set;
-    template <class _Value2, class _Hash2, class _Pred2, class _Alloc2>
-        friend class _LIBCPP_TEMPLATE_VIS unordered_multiset;
-
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset()
-        _NOEXCEPT_(is_nothrow_default_constructible<__table>::value)
-        {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-            __get_db()->__insert_c(this);
-#endif
-        }
-    explicit unordered_multiset(size_type __n, const hasher& __hf = hasher(),
-                                const key_equal& __eql = key_equal());
-    unordered_multiset(size_type __n, const hasher& __hf,
-                       const key_equal& __eql, const allocator_type& __a);
-#if _LIBCPP_STD_VER > 11
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset(size_type __n, const allocator_type& __a)
-        : unordered_multiset(__n, hasher(), key_equal(), __a) {}
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset(size_type __n, const hasher& __hf, const allocator_type& __a)
-        : unordered_multiset(__n, __hf, key_equal(), __a) {}
-#endif
-    template <class _InputIterator>
-        unordered_multiset(_InputIterator __first, _InputIterator __last);
-    template <class _InputIterator>
-        unordered_multiset(_InputIterator __first, _InputIterator __last,
-                      size_type __n, const hasher& __hf = hasher(),
-                      const key_equal& __eql = key_equal());
-    template <class _InputIterator>
-        unordered_multiset(_InputIterator __first, _InputIterator __last,
-                      size_type __n , const hasher& __hf,
-                      const key_equal& __eql, const allocator_type& __a);
-#if _LIBCPP_STD_VER > 11
-    template <class _InputIterator>
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset(_InputIterator __first, _InputIterator __last, 
-                       size_type __n, const allocator_type& __a)
-        : unordered_multiset(__first, __last, __n, hasher(), key_equal(), __a) {}
-    template <class _InputIterator>
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset(_InputIterator __first, _InputIterator __last,
-                       size_type __n, const hasher& __hf, const allocator_type& __a)
-        : unordered_multiset(__first, __last, __n, __hf, key_equal(), __a) {}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    explicit unordered_multiset(const allocator_type& __a);
-    unordered_multiset(const unordered_multiset& __u);
-    unordered_multiset(const unordered_multiset& __u, const allocator_type& __a);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset(unordered_multiset&& __u)
-        _NOEXCEPT_(is_nothrow_move_constructible<__table>::value);
-    unordered_multiset(unordered_multiset&& __u, const allocator_type& __a);
-    unordered_multiset(initializer_list<value_type> __il);
-    unordered_multiset(initializer_list<value_type> __il, size_type __n,
-                       const hasher& __hf = hasher(),
-                       const key_equal& __eql = key_equal());
-    unordered_multiset(initializer_list<value_type> __il, size_type __n,
-                       const hasher& __hf, const key_equal& __eql,
-                       const allocator_type& __a);
-#if _LIBCPP_STD_VER > 11
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset(initializer_list<value_type> __il, size_type __n, const allocator_type& __a)
-      : unordered_multiset(__il, __n, hasher(), key_equal(), __a) {}
-    inline _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset(initializer_list<value_type> __il, size_type __n, const hasher& __hf, const allocator_type& __a)
-      : unordered_multiset(__il, __n, __hf, key_equal(), __a) {}
-#endif
-#endif  // _LIBCPP_CXX03_LANG
-    // ~unordered_multiset() = default;
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset& operator=(const unordered_multiset& __u)
-    {
-        __table_ = __u.__table_;
-        return *this;
-    }
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    unordered_multiset& operator=(unordered_multiset&& __u)
-        _NOEXCEPT_(is_nothrow_move_assignable<__table>::value);
-    unordered_multiset& operator=(initializer_list<value_type> __il);
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT
-        {return allocator_type(__table_.__node_alloc());}
-
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool      empty() const _NOEXCEPT {return __table_.size() == 0;}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT  {return __table_.size();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_size() const _NOEXCEPT {return __table_.max_size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       begin() _NOEXCEPT        {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       end() _NOEXCEPT          {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin()  const _NOEXCEPT {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()    const _NOEXCEPT {return __table_.end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cbegin() const _NOEXCEPT {return __table_.begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator cend()   const _NOEXCEPT {return __table_.end();}
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator emplace(_Args&&... __args)
-            {return __table_.__emplace_multi(_VSTD::forward<_Args>(__args)...);}
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-        iterator emplace_hint(const_iterator __p, _Args&&... __args)
-            {return __table_.__emplace_hint_multi(__p, _VSTD::forward<_Args>(__args)...);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(value_type&& __x) {return __table_.__insert_multi(_VSTD::move(__x));}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, value_type&& __x)
-        {return __table_.__insert_multi(__p, _VSTD::move(__x));}
-    _LIBCPP_INLINE_VISIBILITY
-    void insert(initializer_list<value_type> __il)
-        {insert(__il.begin(), __il.end());}
-#endif  // _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const value_type& __x) {return __table_.__insert_multi(__x);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __p, const value_type& __x)
-        {return __table_.__insert_multi(__p, __x);}
-
-    template <class _InputIterator>
-        _LIBCPP_INLINE_VISIBILITY
-        void insert(_InputIterator __first, _InputIterator __last);
-
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to unordered_multiset::insert()");
-        return __table_.template __node_handle_insert_multi<node_type>(
-            _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __hint, node_type&& __nh)
-    {
-        _LIBCPP_ASSERT(__nh.empty() || __nh.get_allocator() == get_allocator(),
-            "node_type with incompatible allocator passed to unordered_multiset::insert()");
-        return __table_.template __node_handle_insert_multi<node_type>(
-            __hint, _VSTD::move(__nh));
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(const_iterator __position)
-    {
-        return __table_.template __node_handle_extract<node_type>(
-            __position);
-    }
-    _LIBCPP_INLINE_VISIBILITY
-    node_type extract(key_type const& __key)
-    {
-        return __table_.template __node_handle_extract<node_type>(__key);
-    }
-
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_multiset<key_type, _H2, _P2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_multi(__source.__table_);
-    }
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_multiset<key_type, _H2, _P2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_multi(__source.__table_);
-    }
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_set<key_type, _H2, _P2, allocator_type>& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_multi(__source.__table_);
-    }
-    template <class _H2, class _P2>
-    _LIBCPP_INLINE_VISIBILITY
-    void merge(unordered_set<key_type, _H2, _P2, allocator_type>&& __source)
-    {
-        _LIBCPP_ASSERT(__source.get_allocator() == get_allocator(),
-                       "merging container with incompatible allocator");
-        return __table_.__node_handle_merge_multi(__source.__table_);
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __p) {return __table_.erase(__p);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type erase(const key_type& __k) {return __table_.__erase_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator erase(const_iterator __first, const_iterator __last)
-        {return __table_.erase(__first, __last);}
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {__table_.clear();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(unordered_multiset& __u)
-        _NOEXCEPT_(__is_nothrow_swappable<__table>::value)
-        {__table_.swap(__u.__table_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    hasher hash_function() const {return __table_.hash_function();}
-    _LIBCPP_INLINE_VISIBILITY
-    key_equal key_eq() const {return __table_.key_eq();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       find(const key_type& __k)       {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator find(const key_type& __k) const {return __table_.find(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type count(const key_type& __k) const {return __table_.__count_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<iterator, iterator>             equal_range(const key_type& __k)
-        {return __table_.__equal_range_multi(__k);}
-    _LIBCPP_INLINE_VISIBILITY
-    pair<const_iterator, const_iterator> equal_range(const key_type& __k) const
-        {return __table_.__equal_range_multi(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_count() const _NOEXCEPT {return __table_.bucket_count();}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type max_bucket_count() const _NOEXCEPT {return __table_.max_bucket_count();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket_size(size_type __n) const {return __table_.bucket_size(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type bucket(const key_type& __k) const {return __table_.bucket(__k);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator       begin(size_type __n)        {return __table_.begin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    local_iterator       end(size_type __n)          {return __table_.end(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator begin(size_type __n) const  {return __table_.cbegin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator end(size_type __n) const    {return __table_.cend(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator cbegin(size_type __n) const {return __table_.cbegin(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_local_iterator cend(size_type __n) const   {return __table_.cend(__n);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    float load_factor() const _NOEXCEPT {return __table_.load_factor();}
-    _LIBCPP_INLINE_VISIBILITY
-    float max_load_factor() const _NOEXCEPT {return __table_.max_load_factor();}
-    _LIBCPP_INLINE_VISIBILITY
-    void max_load_factor(float __mlf) {__table_.max_load_factor(__mlf);}
-    _LIBCPP_INLINE_VISIBILITY
-    void rehash(size_type __n) {__table_.rehash(__n);}
-    _LIBCPP_INLINE_VISIBILITY
-    void reserve(size_type __n) {__table_.reserve(__n);}
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    bool __dereferenceable(const const_iterator* __i) const
-        {return __table_.__dereferenceable(__i);}
-    bool __decrementable(const const_iterator* __i) const
-        {return __table_.__decrementable(__i);}
-    bool __addable(const const_iterator* __i, ptrdiff_t __n) const
-        {return __table_.__addable(__i, __n);}
-    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const
-        {return __table_.__addable(__i, __n);}
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-};
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        size_type __n, const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        size_type __n, const hasher& __hf, const key_equal& __eql,
-        const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        _InputIterator __first, _InputIterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        _InputIterator __first, _InputIterator __last, size_type __n,
-        const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__first, __last);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        const allocator_type& __a)
-    : __table_(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        const unordered_multiset& __u)
-    : __table_(__u.__table_)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        const unordered_multiset& __u, const allocator_type& __a)
-    : __table_(__u.__table_, __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__u.bucket_count());
-    insert(__u.begin(), __u.end());
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        unordered_multiset&& __u)
-    _NOEXCEPT_(is_nothrow_move_constructible<__table>::value)
-    : __table_(_VSTD::move(__u.__table_))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-    __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        unordered_multiset&& __u, const allocator_type& __a)
-    : __table_(_VSTD::move(__u.__table_), __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__a != __u.get_allocator())
-    {
-        iterator __i = __u.begin();
-        while (__u.size() != 0)
-            __table_.__insert_multi(_VSTD::move(__u.__table_.remove(__i++)->__value_));
-    }
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    else
-        __get_db()->swap(this, &__u);
-#endif
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        initializer_list<value_type> __il)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
-        const key_equal& __eql)
-    : __table_(__hf, __eql)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::unordered_multiset(
-        initializer_list<value_type> __il, size_type __n, const hasher& __hf,
-        const key_equal& __eql, const allocator_type& __a)
-    : __table_(__hf, __eql, __a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    __table_.rehash(__n);
-    insert(__il.begin(), __il.end());
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>&
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::operator=(
-        unordered_multiset&& __u)
-    _NOEXCEPT_(is_nothrow_move_assignable<__table>::value)
-{
-    __table_ = _VSTD::move(__u.__table_);
-    return *this;
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>&
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::operator=(
-        initializer_list<value_type> __il)
-{
-    __table_.__assign_multi(__il.begin(), __il.end());
-    return *this;
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-template <class _InputIterator>
-inline
-void
-unordered_multiset<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first,
-                                                         _InputIterator __last)
-{
-    for (; __first != __last; ++__first)
-        __table_.__insert_multi(*__first);
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
-     unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Value, class _Hash, class _Pred, class _Alloc, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __c, _Predicate __pred)
-{ __libcpp_erase_if_container(__c, __pred); }
-#endif
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-bool
-operator==(const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
-           const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    if (__x.size() != __y.size())
-        return false;
-    typedef typename unordered_multiset<_Value, _Hash, _Pred, _Alloc>::const_iterator
-                                                                 const_iterator;
-    typedef pair<const_iterator, const_iterator> _EqRng;
-    for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;)
-    {
-        _EqRng __xeq = __x.equal_range(*__i);
-        _EqRng __yeq = __y.equal_range(*__i);
-        if (_VSTD::distance(__xeq.first, __xeq.second) !=
-            _VSTD::distance(__yeq.first, __yeq.second) ||
-                  !_VSTD::is_permutation(__xeq.first, __xeq.second, __yeq.first))
-            return false;
-        __i = __xeq.second;
-    }
-    return true;
-}
-
-template <class _Value, class _Hash, class _Pred, class _Alloc>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
-           const unordered_multiset<_Value, _Hash, _Pred, _Alloc>& __y)
-{
-    return !(__x == __y);
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_UNORDERED_SET
diff --git a/lib/libcxx/include/utility b/lib/libcxx/include/utility
deleted file mode 100644
index 74bbc5cf34f..00000000000
--- a/lib/libcxx/include/utility
+++ /dev/null
@@ -1,1625 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- utility -----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_UTILITY
-#define _LIBCPP_UTILITY
-
-/*
-    utility synopsis
-
-#include <initializer_list>
-
-namespace std
-{
-
-template <class T>
-    void
-    swap(T& a, T& b);
-
-namespace rel_ops
-{
-    template<class T> bool operator!=(const T&, const T&);
-    template<class T> bool operator> (const T&, const T&);
-    template<class T> bool operator<=(const T&, const T&);
-    template<class T> bool operator>=(const T&, const T&);
-}
-
-template<class T>
-void
-swap(T& a, T& b) noexcept(is_nothrow_move_constructible<T>::value &&
-                          is_nothrow_move_assignable<T>::value);
-
-template <class T, size_t N>
-void
-swap(T (&a)[N], T (&b)[N]) noexcept(noexcept(swap(*a, *b)));
-
-template <class T> T&& forward(typename remove_reference<T>::type& t) noexcept;  // constexpr in C++14
-template <class T> T&& forward(typename remove_reference<T>::type&& t) noexcept; // constexpr in C++14
-
-template <class T> typename remove_reference<T>::type&& move(T&&) noexcept;      // constexpr in C++14
-
-template <class T>
-    typename conditional
-    <
-        !is_nothrow_move_constructible<T>::value && is_copy_constructible<T>::value,
-        const T&,
-        T&&
-    >::type
-    move_if_noexcept(T& x) noexcept; // constexpr in C++14
-
-template <class T> constexpr add_const_t<T>& as_const(T& t) noexcept;      // C++17
-template <class T>                      void as_const(const T&&) = delete; // C++17
-
-template <class T> typename add_rvalue_reference<T>::type declval() noexcept;
-
-template <class T1, class T2>
-struct pair
-{
-    typedef T1 first_type;
-    typedef T2 second_type;
-
-    T1 first;
-    T2 second;
-
-    pair(const pair&) = default;
-    pair(pair&&) = default;
-    constexpr pair();
-    pair(const T1& x, const T2& y);                          // constexpr in C++14
-    template <class U, class V> pair(U&& x, V&& y);          // constexpr in C++14
-    template <class U, class V> pair(const pair<U, V>& p);   // constexpr in C++14
-    template <class U, class V> pair(pair<U, V>&& p);        // constexpr in C++14
-    template <class... Args1, class... Args2>
-        pair(piecewise_construct_t, tuple<Args1...> first_args,
-             tuple<Args2...> second_args);
-
-    template <class U, class V> pair& operator=(const pair<U, V>& p);
-    pair& operator=(pair&& p) noexcept(is_nothrow_move_assignable<T1>::value &&
-                                       is_nothrow_move_assignable<T2>::value);
-    template <class U, class V> pair& operator=(pair<U, V>&& p);
-
-    void swap(pair& p) noexcept(is_nothrow_swappable_v<T1> &&
-                                is_nothrow_swappable_v<T2>);
-};
-
-template <class T1, class T2> bool operator==(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
-template <class T1, class T2> bool operator!=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
-template <class T1, class T2> bool operator< (const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
-template <class T1, class T2> bool operator> (const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
-template <class T1, class T2> bool operator>=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
-template <class T1, class T2> bool operator<=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
-
-template <class T1, class T2> pair<V1, V2> make_pair(T1&&, T2&&);   // constexpr in C++14
-template <class T1, class T2>
-void
-swap(pair<T1, T2>& x, pair<T1, T2>& y) noexcept(noexcept(x.swap(y)));
-
-struct piecewise_construct_t { };
-inline constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
-
-template <class T> struct tuple_size;
-template <size_t I, class T> class tuple_element;
-
-template <class T1, class T2> struct tuple_size<pair<T1, T2> >;
-template <class T1, class T2> struct tuple_element<0, pair<T1, T2> >;
-template <class T1, class T2> struct tuple_element<1, pair<T1, T2> >;
-
-template<size_t I, class T1, class T2>
-    typename tuple_element<I, pair<T1, T2> >::type&
-    get(pair<T1, T2>&) noexcept; // constexpr in C++14
-
-template<size_t I, class T1, class T2>
-    const typename tuple_element<I, pair<T1, T2> >::type&
-    get(const pair<T1, T2>&) noexcept; // constexpr in C++14
-
-template<size_t I, class T1, class T2>
-    typename tuple_element<I, pair<T1, T2> >::type&&
-    get(pair<T1, T2>&&) noexcept; // constexpr in C++14
-
-template<size_t I, class T1, class T2>
-    const typename tuple_element<I, pair<T1, T2> >::type&&
-    get(const pair<T1, T2>&&) noexcept; // constexpr in C++14
-
-template<class T1, class T2>
-    constexpr T1& get(pair<T1, T2>&) noexcept; // C++14
-
-template<class T1, class T2>
-    constexpr const T1& get(const pair<T1, T2>&) noexcept; // C++14
-
-template<class T1, class T2>
-    constexpr T1&& get(pair<T1, T2>&&) noexcept; // C++14
-
-template<class T1, class T2>
-    constexpr const T1&& get(const pair<T1, T2>&&) noexcept; // C++14
-
-template<class T1, class T2>
-    constexpr T1& get(pair<T2, T1>&) noexcept; // C++14
-
-template<class T1, class T2>
-    constexpr const T1& get(const pair<T2, T1>&) noexcept; // C++14
-
-template<class T1, class T2>
-    constexpr T1&& get(pair<T2, T1>&&) noexcept; // C++14
-
-template<class T1, class T2>
-    constexpr const T1&& get(const pair<T2, T1>&&) noexcept; // C++14
-
-// C++14
-
-template<class T, T... I>
-struct integer_sequence
-{
-    typedef T value_type;
-
-    static constexpr size_t size() noexcept;
-};
-
-template<size_t... I>
-  using index_sequence = integer_sequence<size_t, I...>;
-
-template<class T, T N>
-  using make_integer_sequence = integer_sequence<T, 0, 1, ..., N-1>;
-template<size_t N>
-  using make_index_sequence = make_integer_sequence<size_t, N>;
-
-template<class... T>
-  using index_sequence_for = make_index_sequence<sizeof...(T)>;
-
-template<class T, class U=T>
-    T exchange(T& obj, U&& new_value);
-
-// 20.2.7, in-place construction // C++17
-struct in_place_t {
-  explicit in_place_t() = default;
-};
-inline constexpr in_place_t in_place{};
-template <class T>
-  struct in_place_type_t {
-    explicit in_place_type_t() = default;
-  };
-template <class T>
-  inline constexpr in_place_type_t<T> in_place_type{};
-template <size_t I>
-  struct in_place_index_t {
-    explicit in_place_index_t() = default;
-  };
-template <size_t I>
-  inline constexpr in_place_index_t<I> in_place_index{};
-
-}  // std
-
-*/
-
-#include <__config>
-#include <__tuple>
-#include <type_traits>
-#include <initializer_list>
-#include <cstddef>
-#include <cstring>
-#include <cstdint>
-#include <version>
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-namespace rel_ops
-{
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const _Tp& __x, const _Tp& __y)
-{
-    return !(__x == __y);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const _Tp& __x, const _Tp& __y)
-{
-    return __y < __x;
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const _Tp& __x, const _Tp& __y)
-{
-    return !(__y < __x);
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const _Tp& __x, const _Tp& __y)
-{
-    return !(__x < __y);
-}
-
-}  // rel_ops
-
-// swap_ranges
-
-
-template <class _ForwardIterator1, class _ForwardIterator2>
-inline _LIBCPP_INLINE_VISIBILITY
-_ForwardIterator2
-swap_ranges(_ForwardIterator1 __first1, _ForwardIterator1 __last1, _ForwardIterator2 __first2)
-{
-    for(; __first1 != __last1; ++__first1, (void) ++__first2)
-        swap(*__first1, *__first2);
-    return __first2;
-}
-
-// forward declared in <type_traits>
-template<class _Tp, size_t _Np>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if<
-    __is_swappable<_Tp>::value
->::type
-swap(_Tp (&__a)[_Np], _Tp (&__b)[_Np]) _NOEXCEPT_(__is_nothrow_swappable<_Tp>::value)
-{
-    _VSTD::swap_ranges(__a, __a + _Np, __b);
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-#ifndef _LIBCPP_CXX03_LANG
-typename conditional
-<
-    !is_nothrow_move_constructible<_Tp>::value && is_copy_constructible<_Tp>::value,
-    const _Tp&,
-    _Tp&&
->::type
-#else  // _LIBCPP_CXX03_LANG
-const _Tp&
-#endif
-move_if_noexcept(_Tp& __x) _NOEXCEPT
-{
-    return _VSTD::move(__x);
-}
-
-#if _LIBCPP_STD_VER > 14
-template <class _Tp> constexpr add_const_t<_Tp>& as_const(_Tp& __t) noexcept { return __t; }
-template <class _Tp>                        void as_const(const _Tp&&) = delete;
-#endif
-
-struct _LIBCPP_TEMPLATE_VIS piecewise_construct_t { };
-#if defined(_LIBCPP_CXX03_LANG) || defined(_LIBCPP_BUILDING_LIBRARY)
-extern _LIBCPP_EXPORTED_FROM_ABI const piecewise_construct_t piecewise_construct;// = piecewise_construct_t();
-#else
-/* _LIBCPP_INLINE_VAR */ constexpr piecewise_construct_t piecewise_construct = piecewise_construct_t();
-#endif
-
-#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
-template <class, class>
-struct __non_trivially_copyable_base {
-  _LIBCPP_CONSTEXPR _LIBCPP_INLINE_VISIBILITY
-  __non_trivially_copyable_base() _NOEXCEPT {}
-  _LIBCPP_CONSTEXPR_AFTER_CXX11 _LIBCPP_INLINE_VISIBILITY
-  __non_trivially_copyable_base(__non_trivially_copyable_base const&) _NOEXCEPT {}
-};
-#endif
-
-template <class _T1, class _T2>
-struct _LIBCPP_TEMPLATE_VIS pair
-#if defined(_LIBCPP_DEPRECATED_ABI_DISABLE_PAIR_TRIVIAL_COPY_CTOR)
-: private __non_trivially_copyable_base<_T1, _T2>
-#endif
-{
-    typedef _T1 first_type;
-    typedef _T2 second_type;
-
-    _T1 first;
-    _T2 second;
-
-#if !defined(_LIBCPP_CXX03_LANG)
-    pair(pair const&) = default;
-    pair(pair&&) = default;
-#else
-  // Use the implicitly declared copy constructor in C++03
-#endif
-
-#ifdef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    pair() : first(), second() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair(_T1 const& __t1, _T2 const& __t2) : first(__t1), second(__t2) {}
-
-    template <class _U1, class _U2>
-    _LIBCPP_INLINE_VISIBILITY
-    pair(const pair<_U1, _U2>& __p) : first(__p.first), second(__p.second) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair& operator=(pair const& __p) {
-        first = __p.first;
-        second = __p.second;
-        return *this;
-    }
-#else
-    template <bool _Val>
-    using _EnableB = typename enable_if<_Val, bool>::type;
-
-    struct _CheckArgs {
-      template <class _U1, class _U2>
-      static constexpr bool __enable_default() {
-          return is_default_constructible<_U1>::value
-              && is_default_constructible<_U2>::value;
-      }
-
-      template <class _U1, class _U2>
-      static constexpr bool __enable_explicit() {
-          return is_constructible<first_type, _U1>::value
-              && is_constructible<second_type, _U2>::value
-              && (!is_convertible<_U1, first_type>::value
-                  || !is_convertible<_U2, second_type>::value);
-      }
-
-      template <class _U1, class _U2>
-      static constexpr bool __enable_implicit() {
-          return is_constructible<first_type, _U1>::value
-              && is_constructible<second_type, _U2>::value
-              && is_convertible<_U1, first_type>::value
-              && is_convertible<_U2, second_type>::value;
-      }
-    };
-
-    template <bool _MaybeEnable>
-    using _CheckArgsDep = typename conditional<
-      _MaybeEnable, _CheckArgs, __check_tuple_constructor_fail>::type;
-
-    struct _CheckTupleLikeConstructor {
-        template <class _Tuple>
-        static constexpr bool __enable_implicit() {
-            return __tuple_convertible<_Tuple, pair>::value;
-        }
-
-        template <class _Tuple>
-        static constexpr bool __enable_explicit() {
-            return __tuple_constructible<_Tuple, pair>::value
-               && !__tuple_convertible<_Tuple, pair>::value;
-        }
-
-        template <class _Tuple>
-        static constexpr bool __enable_assign() {
-            return __tuple_assignable<_Tuple, pair>::value;
-        }
-    };
-
-    template <class _Tuple>
-    using _CheckTLC = typename conditional<
-        __tuple_like_with_size<_Tuple, 2>::value
-            && !is_same<typename decay<_Tuple>::type, pair>::value,
-        _CheckTupleLikeConstructor,
-        __check_tuple_constructor_fail
-    >::type;
-
-    template<bool _Dummy = true, _EnableB<
-            _CheckArgsDep<_Dummy>::template __enable_default<_T1, _T2>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
-    pair() _NOEXCEPT_(is_nothrow_default_constructible<first_type>::value &&
-                      is_nothrow_default_constructible<second_type>::value)
-        : first(), second() {}
-
-    template <bool _Dummy = true, _EnableB<
-             _CheckArgsDep<_Dummy>::template __enable_explicit<_T1 const&, _T2 const&>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    explicit pair(_T1 const& __t1, _T2 const& __t2)
-        _NOEXCEPT_(is_nothrow_copy_constructible<first_type>::value &&
-                   is_nothrow_copy_constructible<second_type>::value)
-        : first(__t1), second(__t2) {}
-
-    template<bool _Dummy = true, _EnableB<
-            _CheckArgsDep<_Dummy>::template __enable_implicit<_T1 const&, _T2 const&>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    pair(_T1 const& __t1, _T2 const& __t2)
-        _NOEXCEPT_(is_nothrow_copy_constructible<first_type>::value &&
-                   is_nothrow_copy_constructible<second_type>::value)
-        : first(__t1), second(__t2) {}
-
-    template<class _U1, class _U2, _EnableB<
-             _CheckArgs::template __enable_explicit<_U1, _U2>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    explicit pair(_U1&& __u1, _U2&& __u2)
-        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1>::value &&
-                    is_nothrow_constructible<second_type, _U2>::value))
-        : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
-
-    template<class _U1, class _U2, _EnableB<
-            _CheckArgs::template __enable_implicit<_U1, _U2>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    pair(_U1&& __u1, _U2&& __u2)
-        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1>::value &&
-                    is_nothrow_constructible<second_type, _U2>::value))
-        : first(_VSTD::forward<_U1>(__u1)), second(_VSTD::forward<_U2>(__u2)) {}
-
-    template<class _U1, class _U2, _EnableB<
-            _CheckArgs::template __enable_explicit<_U1 const&, _U2 const&>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    explicit pair(pair<_U1, _U2> const& __p)
-        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1 const&>::value &&
-                    is_nothrow_constructible<second_type, _U2 const&>::value))
-        : first(__p.first), second(__p.second) {}
-
-    template<class _U1, class _U2, _EnableB<
-            _CheckArgs::template __enable_implicit<_U1 const&, _U2 const&>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    pair(pair<_U1, _U2> const& __p)
-        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1 const&>::value &&
-                    is_nothrow_constructible<second_type, _U2 const&>::value))
-        : first(__p.first), second(__p.second) {}
-
-    template<class _U1, class _U2, _EnableB<
-            _CheckArgs::template __enable_explicit<_U1, _U2>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    explicit pair(pair<_U1, _U2>&&__p)
-        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1&&>::value &&
-                    is_nothrow_constructible<second_type, _U2&&>::value))
-        : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
-
-    template<class _U1, class _U2, _EnableB<
-            _CheckArgs::template __enable_implicit<_U1, _U2>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    pair(pair<_U1, _U2>&& __p)
-        _NOEXCEPT_((is_nothrow_constructible<first_type, _U1&&>::value &&
-                    is_nothrow_constructible<second_type, _U2&&>::value))
-        : first(_VSTD::forward<_U1>(__p.first)), second(_VSTD::forward<_U2>(__p.second)) {}
-
-    template<class _Tuple, _EnableB<
-            _CheckTLC<_Tuple>::template __enable_explicit<_Tuple>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    explicit pair(_Tuple&& __p)
-        : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
-          second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
-
-    template<class _Tuple, _EnableB<
-            _CheckTLC<_Tuple>::template __enable_implicit<_Tuple>()
-    > = false>
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    pair(_Tuple&& __p)
-        : first(_VSTD::get<0>(_VSTD::forward<_Tuple>(__p))),
-          second(_VSTD::get<1>(_VSTD::forward<_Tuple>(__p))) {}
-
-    template <class... _Args1, class... _Args2>
-    _LIBCPP_INLINE_VISIBILITY
-    pair(piecewise_construct_t __pc,
-         tuple<_Args1...> __first_args, tuple<_Args2...> __second_args)
-        _NOEXCEPT_((is_nothrow_constructible<first_type, _Args1...>::value &&
-                    is_nothrow_constructible<second_type, _Args2...>::value))
-        : pair(__pc, __first_args, __second_args,
-                typename __make_tuple_indices<sizeof...(_Args1)>::type(),
-                typename __make_tuple_indices<sizeof...(_Args2) >::type()) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair& operator=(typename conditional<
-                        is_copy_assignable<first_type>::value &&
-                        is_copy_assignable<second_type>::value,
-                    pair, __nat>::type const& __p)
-        _NOEXCEPT_(is_nothrow_copy_assignable<first_type>::value &&
-                   is_nothrow_copy_assignable<second_type>::value)
-    {
-        first = __p.first;
-        second = __p.second;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    pair& operator=(typename conditional<
-                        is_move_assignable<first_type>::value &&
-                        is_move_assignable<second_type>::value,
-                    pair, __nat>::type&& __p)
-        _NOEXCEPT_(is_nothrow_move_assignable<first_type>::value &&
-                   is_nothrow_move_assignable<second_type>::value)
-    {
-        first = _VSTD::forward<first_type>(__p.first);
-        second = _VSTD::forward<second_type>(__p.second);
-        return *this;
-    }
-
-    template <class _Tuple, _EnableB<
-            _CheckTLC<_Tuple>::template __enable_assign<_Tuple>()
-     > = false>
-    _LIBCPP_INLINE_VISIBILITY
-    pair& operator=(_Tuple&& __p) {
-        first = _VSTD::get<0>(_VSTD::forward<_Tuple>(__p));
-        second = _VSTD::get<1>(_VSTD::forward<_Tuple>(__p));
-        return *this;
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    void
-    swap(pair& __p) _NOEXCEPT_(__is_nothrow_swappable<first_type>::value &&
-                               __is_nothrow_swappable<second_type>::value)
-    {
-        using _VSTD::swap;
-        swap(first,  __p.first);
-        swap(second, __p.second);
-    }
-private:
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
-        _LIBCPP_INLINE_VISIBILITY
-        pair(piecewise_construct_t,
-             tuple<_Args1...>& __first_args, tuple<_Args2...>& __second_args,
-             __tuple_indices<_I1...>, __tuple_indices<_I2...>);
-#endif
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class _T1, class _T2>
-pair(_T1, _T2) -> pair<_T1, _T2>;
-#endif // _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator==(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
-{
-    return __x.first == __y.first && __x.second == __y.second;
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator!=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator< (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
-{
-    return __x.first < __y.first || (!(__y.first < __x.first) && __x.second < __y.second);
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator> (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
-{
-    return __y < __x;
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator>=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-bool
-operator<=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_swappable<_T1>::value &&
-    __is_swappable<_T2>::value,
-    void
->::type
-swap(pair<_T1, _T2>& __x, pair<_T1, _T2>& __y)
-                     _NOEXCEPT_((__is_nothrow_swappable<_T1>::value &&
-                                 __is_nothrow_swappable<_T2>::value))
-{
-    __x.swap(__y);
-}
-
-template <class _Tp>
-struct __unwrap_reference { typedef _Tp type; };
-
-template <class _Tp>
-struct __unwrap_reference<reference_wrapper<_Tp> > { typedef _Tp& type; };
-
-#if _LIBCPP_STD_VER > 17
-template <class _Tp>
-struct unwrap_reference : __unwrap_reference<_Tp> { };
-
-template <class _Tp>
-struct unwrap_ref_decay : unwrap_reference<typename decay<_Tp>::type> { };
-#endif // > C++17
-
-template <class _Tp>
-struct __unwrap_ref_decay
-#if _LIBCPP_STD_VER > 17
-    : unwrap_ref_decay<_Tp>
-#else
-    : __unwrap_reference<typename decay<_Tp>::type>
-#endif
-{ };
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-pair<typename __unwrap_ref_decay<_T1>::type, typename __unwrap_ref_decay<_T2>::type>
-make_pair(_T1&& __t1, _T2&& __t2)
-{
-    return pair<typename __unwrap_ref_decay<_T1>::type, typename __unwrap_ref_decay<_T2>::type>
-               (_VSTD::forward<_T1>(__t1), _VSTD::forward<_T2>(__t2));
-}
-
-#else  // _LIBCPP_CXX03_LANG
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-pair<_T1,_T2>
-make_pair(_T1 __x, _T2 __y)
-{
-    return pair<_T1, _T2>(__x, __y);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _T1, class _T2>
-  struct _LIBCPP_TEMPLATE_VIS tuple_size<pair<_T1, _T2> >
-    : public integral_constant<size_t, 2> {};
-
-template <size_t _Ip, class _T1, class _T2>
-class _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, pair<_T1, _T2> >
-{
-    static_assert(_Ip < 2, "Index out of bounds in std::tuple_element<std::pair<T1, T2>>");
-};
-
-template <class _T1, class _T2>
-class _LIBCPP_TEMPLATE_VIS tuple_element<0, pair<_T1, _T2> >
-{
-public:
-    typedef _T1 type;
-};
-
-template <class _T1, class _T2>
-class _LIBCPP_TEMPLATE_VIS tuple_element<1, pair<_T1, _T2> >
-{
-public:
-    typedef _T2 type;
-};
-
-template <size_t _Ip> struct __get_pair;
-
-template <>
-struct __get_pair<0>
-{
-    template <class _T1, class _T2>
-    static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    _T1&
-    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
-
-    template <class _T1, class _T2>
-    static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const _T1&
-    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.first;}
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _T1, class _T2>
-    static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    _T1&&
-    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T1>(__p.first);}
-
-    template <class _T1, class _T2>
-    static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const _T1&&
-    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T1>(__p.first);}
-#endif  // _LIBCPP_CXX03_LANG
-};
-
-template <>
-struct __get_pair<1>
-{
-    template <class _T1, class _T2>
-    static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    _T2&
-    get(pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
-
-    template <class _T1, class _T2>
-    static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const _T2&
-    get(const pair<_T1, _T2>& __p) _NOEXCEPT {return __p.second;}
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _T1, class _T2>
-    static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    _T2&&
-    get(pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<_T2>(__p.second);}
-
-    template <class _T1, class _T2>
-    static
-    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-    const _T2&&
-    get(const pair<_T1, _T2>&& __p) _NOEXCEPT {return _VSTD::forward<const _T2>(__p.second);}
-#endif  // _LIBCPP_CXX03_LANG
-};
-
-template <size_t _Ip, class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename tuple_element<_Ip, pair<_T1, _T2> >::type&
-get(pair<_T1, _T2>& __p) _NOEXCEPT
-{
-    return __get_pair<_Ip>::get(__p);
-}
-
-template <size_t _Ip, class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const typename tuple_element<_Ip, pair<_T1, _T2> >::type&
-get(const pair<_T1, _T2>& __p) _NOEXCEPT
-{
-    return __get_pair<_Ip>::get(__p);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <size_t _Ip, class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
-get(pair<_T1, _T2>&& __p) _NOEXCEPT
-{
-    return __get_pair<_Ip>::get(_VSTD::move(__p));
-}
-
-template <size_t _Ip, class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
-const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
-get(const pair<_T1, _T2>&& __p) _NOEXCEPT
-{
-    return __get_pair<_Ip>::get(_VSTD::move(__p));
-}
-#endif  // _LIBCPP_CXX03_LANG
-
-#if _LIBCPP_STD_VER > 11
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 & get(pair<_T1, _T2>& __p) _NOEXCEPT
-{
-    return __get_pair<0>::get(__p);
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 const & get(pair<_T1, _T2> const& __p) _NOEXCEPT
-{
-    return __get_pair<0>::get(__p);
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 && get(pair<_T1, _T2>&& __p) _NOEXCEPT
-{
-    return __get_pair<0>::get(_VSTD::move(__p));
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 const && get(pair<_T1, _T2> const&& __p) _NOEXCEPT
-{
-    return __get_pair<0>::get(_VSTD::move(__p));
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 & get(pair<_T2, _T1>& __p) _NOEXCEPT
-{
-    return __get_pair<1>::get(__p);
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 const & get(pair<_T2, _T1> const& __p) _NOEXCEPT
-{
-    return __get_pair<1>::get(__p);
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 && get(pair<_T2, _T1>&& __p) _NOEXCEPT
-{
-    return __get_pair<1>::get(_VSTD::move(__p));
-}
-
-template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _T1 const && get(pair<_T2, _T1> const&& __p) _NOEXCEPT
-{
-    return __get_pair<1>::get(_VSTD::move(__p));
-}
-
-#endif
-
-#if _LIBCPP_STD_VER > 11
-
-template<class _Tp, _Tp... _Ip>
-struct _LIBCPP_TEMPLATE_VIS integer_sequence
-{
-    typedef _Tp value_type;
-    static_assert( is_integral<_Tp>::value,
-                  "std::integer_sequence can only be instantiated with an integral type" );
-    static
-    _LIBCPP_INLINE_VISIBILITY
-    constexpr
-    size_t
-    size() noexcept { return sizeof...(_Ip); }
-};
-
-template<size_t... _Ip>
-    using index_sequence = integer_sequence<size_t, _Ip...>;
-
-#if __has_builtin(__make_integer_seq) && !defined(_LIBCPP_TESTING_FALLBACK_MAKE_INTEGER_SEQUENCE)
-
-template <class _Tp, _Tp _Ep>
-using __make_integer_sequence = __make_integer_seq<integer_sequence, _Tp, _Ep>;
-
-#else
-
-template<typename _Tp, _Tp _Np> using __make_integer_sequence_unchecked =
-  typename __detail::__make<_Np>::type::template __convert<integer_sequence, _Tp>;
-
-template <class _Tp, _Tp _Ep>
-struct __make_integer_sequence_checked
-{
-    static_assert(is_integral<_Tp>::value,
-                  "std::make_integer_sequence can only be instantiated with an integral type" );
-    static_assert(0 <= _Ep, "std::make_integer_sequence must have a non-negative sequence length");
-    // Workaround GCC bug by preventing bad installations when 0 <= _Ep
-    // https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68929
-    typedef __make_integer_sequence_unchecked<_Tp, 0 <= _Ep ? _Ep : 0> type;
-};
-
-template <class _Tp, _Tp _Ep>
-using __make_integer_sequence = typename __make_integer_sequence_checked<_Tp, _Ep>::type;
-
-#endif
-
-template<class _Tp, _Tp _Np>
-    using make_integer_sequence = __make_integer_sequence<_Tp, _Np>;
-
-template<size_t _Np>
-    using make_index_sequence = make_integer_sequence<size_t, _Np>;
-
-template<class... _Tp>
-    using index_sequence_for = make_index_sequence<sizeof...(_Tp)>;
-
-#endif  // _LIBCPP_STD_VER > 11
-
-#if _LIBCPP_STD_VER > 11
-template<class _T1, class _T2 = _T1>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
-_T1 exchange(_T1& __obj, _T2 && __new_value)
-{
-    _T1 __old_value = _VSTD::move(__obj);
-    __obj = _VSTD::forward<_T2>(__new_value);
-    return __old_value;
-}
-#endif  // _LIBCPP_STD_VER > 11
-
-#if _LIBCPP_STD_VER > 14
-
-struct _LIBCPP_TYPE_VIS in_place_t {
-    explicit in_place_t() = default;
-};
-_LIBCPP_INLINE_VAR constexpr in_place_t in_place{};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS in_place_type_t {
-    explicit in_place_type_t() = default;
-};
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr in_place_type_t<_Tp> in_place_type{};
-
-template <size_t _Idx>
-struct _LIBCPP_TYPE_VIS in_place_index_t {
-    explicit in_place_index_t() = default;
-};
-template <size_t _Idx>
-_LIBCPP_INLINE_VAR constexpr in_place_index_t<_Idx> in_place_index{};
-
-template <class _Tp> struct __is_inplace_type_imp : false_type {};
-template <class _Tp> struct __is_inplace_type_imp<in_place_type_t<_Tp>> : true_type {};
-
-template <class _Tp>
-using __is_inplace_type = __is_inplace_type_imp<__uncvref_t<_Tp>>;
-
-template <class _Tp> struct __is_inplace_index_imp : false_type {};
-template <size_t _Idx> struct __is_inplace_index_imp<in_place_index_t<_Idx>> : true_type {};
-
-template <class _Tp>
-using __is_inplace_index = __is_inplace_index_imp<__uncvref_t<_Tp>>;
-
-#endif // _LIBCPP_STD_VER > 14
-
-template <class _Arg, class _Result>
-struct _LIBCPP_TEMPLATE_VIS unary_function
-{
-    typedef _Arg    argument_type;
-    typedef _Result result_type;
-};
-
-template <class _Size>
-inline _LIBCPP_INLINE_VISIBILITY
-_Size
-__loadword(const void* __p)
-{
-    _Size __r;
-    std::memcpy(&__r, __p, sizeof(__r));
-    return __r;
-}
-
-// We use murmur2 when size_t is 32 bits, and cityhash64 when size_t
-// is 64 bits.  This is because cityhash64 uses 64bit x 64bit
-// multiplication, which can be very slow on 32-bit systems.
-template <class _Size, size_t = sizeof(_Size)*__CHAR_BIT__>
-struct __murmur2_or_cityhash;
-
-template <class _Size>
-struct __murmur2_or_cityhash<_Size, 32>
-{
-    inline _Size operator()(const void* __key, _Size __len)
-         _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK;
-};
-
-// murmur2
-template <class _Size>
-_Size
-__murmur2_or_cityhash<_Size, 32>::operator()(const void* __key, _Size __len)
-{
-    const _Size __m = 0x5bd1e995;
-    const _Size __r = 24;
-    _Size __h = __len;
-    const unsigned char* __data = static_cast<const unsigned char*>(__key);
-    for (; __len >= 4; __data += 4, __len -= 4)
-    {
-        _Size __k = __loadword<_Size>(__data);
-        __k *= __m;
-        __k ^= __k >> __r;
-        __k *= __m;
-        __h *= __m;
-        __h ^= __k;
-    }
-    switch (__len)
-    {
-    case 3:
-        __h ^= __data[2] << 16;
-        _LIBCPP_FALLTHROUGH();
-    case 2:
-        __h ^= __data[1] << 8;
-        _LIBCPP_FALLTHROUGH();
-    case 1:
-        __h ^= __data[0];
-        __h *= __m;
-    }
-    __h ^= __h >> 13;
-    __h *= __m;
-    __h ^= __h >> 15;
-    return __h;
-}
-
-template <class _Size>
-struct __murmur2_or_cityhash<_Size, 64>
-{
-    inline _Size operator()(const void* __key, _Size __len)  _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK;
-
- private:
-  // Some primes between 2^63 and 2^64.
-  static const _Size __k0 = 0xc3a5c85c97cb3127ULL;
-  static const _Size __k1 = 0xb492b66fbe98f273ULL;
-  static const _Size __k2 = 0x9ae16a3b2f90404fULL;
-  static const _Size __k3 = 0xc949d7c7509e6557ULL;
-
-  static _Size __rotate(_Size __val, int __shift) {
-    return __shift == 0 ? __val : ((__val >> __shift) | (__val << (64 - __shift)));
-  }
-
-  static _Size __rotate_by_at_least_1(_Size __val, int __shift) {
-    return (__val >> __shift) | (__val << (64 - __shift));
-  }
-
-  static _Size __shift_mix(_Size __val) {
-    return __val ^ (__val >> 47);
-  }
-
-  static _Size __hash_len_16(_Size __u, _Size __v)
-     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-  {
-    const _Size __mul = 0x9ddfea08eb382d69ULL;
-    _Size __a = (__u ^ __v) * __mul;
-    __a ^= (__a >> 47);
-    _Size __b = (__v ^ __a) * __mul;
-    __b ^= (__b >> 47);
-    __b *= __mul;
-    return __b;
-  }
-
-  static _Size __hash_len_0_to_16(const char* __s, _Size __len)
-     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-  {
-    if (__len > 8) {
-      const _Size __a = __loadword<_Size>(__s);
-      const _Size __b = __loadword<_Size>(__s + __len - 8);
-      return __hash_len_16(__a, __rotate_by_at_least_1(__b + __len, __len)) ^ __b;
-    }
-    if (__len >= 4) {
-      const uint32_t __a = __loadword<uint32_t>(__s);
-      const uint32_t __b = __loadword<uint32_t>(__s + __len - 4);
-      return __hash_len_16(__len + (__a << 3), __b);
-    }
-    if (__len > 0) {
-      const unsigned char __a = __s[0];
-      const unsigned char __b = __s[__len >> 1];
-      const unsigned char __c = __s[__len - 1];
-      const uint32_t __y = static_cast<uint32_t>(__a) +
-                           (static_cast<uint32_t>(__b) << 8);
-      const uint32_t __z = __len + (static_cast<uint32_t>(__c) << 2);
-      return __shift_mix(__y * __k2 ^ __z * __k3) * __k2;
-    }
-    return __k2;
-  }
-
-  static _Size __hash_len_17_to_32(const char *__s, _Size __len)
-     _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-  {
-    const _Size __a = __loadword<_Size>(__s) * __k1;
-    const _Size __b = __loadword<_Size>(__s + 8);
-    const _Size __c = __loadword<_Size>(__s + __len - 8) * __k2;
-    const _Size __d = __loadword<_Size>(__s + __len - 16) * __k0;
-    return __hash_len_16(__rotate(__a - __b, 43) + __rotate(__c, 30) + __d,
-                         __a + __rotate(__b ^ __k3, 20) - __c + __len);
-  }
-
-  // Return a 16-byte hash for 48 bytes.  Quick and dirty.
-  // Callers do best to use "random-looking" values for a and b.
-  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
-      _Size __w, _Size __x, _Size __y, _Size __z, _Size __a, _Size __b)
-        _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-  {
-    __a += __w;
-    __b = __rotate(__b + __a + __z, 21);
-    const _Size __c = __a;
-    __a += __x;
-    __a += __y;
-    __b += __rotate(__a, 44);
-    return pair<_Size, _Size>(__a + __z, __b + __c);
-  }
-
-  // Return a 16-byte hash for s[0] ... s[31], a, and b.  Quick and dirty.
-  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
-      const char* __s, _Size __a, _Size __b)
-    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-  {
-    return __weak_hash_len_32_with_seeds(__loadword<_Size>(__s),
-                                         __loadword<_Size>(__s + 8),
-                                         __loadword<_Size>(__s + 16),
-                                         __loadword<_Size>(__s + 24),
-                                         __a,
-                                         __b);
-  }
-
-  // Return an 8-byte hash for 33 to 64 bytes.
-  static _Size __hash_len_33_to_64(const char *__s, size_t __len)
-    _LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
-  {
-    _Size __z = __loadword<_Size>(__s + 24);
-    _Size __a = __loadword<_Size>(__s) +
-                (__len + __loadword<_Size>(__s + __len - 16)) * __k0;
-    _Size __b = __rotate(__a + __z, 52);
-    _Size __c = __rotate(__a, 37);
-    __a += __loadword<_Size>(__s + 8);
-    __c += __rotate(__a, 7);
-    __a += __loadword<_Size>(__s + 16);
-    _Size __vf = __a + __z;
-    _Size __vs = __b + __rotate(__a, 31) + __c;
-    __a = __loadword<_Size>(__s + 16) + __loadword<_Size>(__s + __len - 32);
-    __z += __loadword<_Size>(__s + __len - 8);
-    __b = __rotate(__a + __z, 52);
-    __c = __rotate(__a, 37);
-    __a += __loadword<_Size>(__s + __len - 24);
-    __c += __rotate(__a, 7);
-    __a += __loadword<_Size>(__s + __len - 16);
-    _Size __wf = __a + __z;
-    _Size __ws = __b + __rotate(__a, 31) + __c;
-    _Size __r = __shift_mix((__vf + __ws) * __k2 + (__wf + __vs) * __k0);
-    return __shift_mix(__r * __k0 + __vs) * __k2;
-  }
-};
-
-// cityhash64
-template <class _Size>
-_Size
-__murmur2_or_cityhash<_Size, 64>::operator()(const void* __key, _Size __len)
-{
-  const char* __s = static_cast<const char*>(__key);
-  if (__len <= 32) {
-    if (__len <= 16) {
-      return __hash_len_0_to_16(__s, __len);
-    } else {
-      return __hash_len_17_to_32(__s, __len);
-    }
-  } else if (__len <= 64) {
-    return __hash_len_33_to_64(__s, __len);
-  }
-
-  // For strings over 64 bytes we hash the end first, and then as we
-  // loop we keep 56 bytes of state: v, w, x, y, and z.
-  _Size __x = __loadword<_Size>(__s + __len - 40);
-  _Size __y = __loadword<_Size>(__s + __len - 16) +
-              __loadword<_Size>(__s + __len - 56);
-  _Size __z = __hash_len_16(__loadword<_Size>(__s + __len - 48) + __len,
-                          __loadword<_Size>(__s + __len - 24));
-  pair<_Size, _Size> __v = __weak_hash_len_32_with_seeds(__s + __len - 64, __len, __z);
-  pair<_Size, _Size> __w = __weak_hash_len_32_with_seeds(__s + __len - 32, __y + __k1, __x);
-  __x = __x * __k1 + __loadword<_Size>(__s);
-
-  // Decrease len to the nearest multiple of 64, and operate on 64-byte chunks.
-  __len = (__len - 1) & ~static_cast<_Size>(63);
-  do {
-    __x = __rotate(__x + __y + __v.first + __loadword<_Size>(__s + 8), 37) * __k1;
-    __y = __rotate(__y + __v.second + __loadword<_Size>(__s + 48), 42) * __k1;
-    __x ^= __w.second;
-    __y += __v.first + __loadword<_Size>(__s + 40);
-    __z = __rotate(__z + __w.first, 33) * __k1;
-    __v = __weak_hash_len_32_with_seeds(__s, __v.second * __k1, __x + __w.first);
-    __w = __weak_hash_len_32_with_seeds(__s + 32, __z + __w.second,
-                                        __y + __loadword<_Size>(__s + 16));
-    std::swap(__z, __x);
-    __s += 64;
-    __len -= 64;
-  } while (__len != 0);
-  return __hash_len_16(
-      __hash_len_16(__v.first, __w.first) + __shift_mix(__y) * __k1 + __z,
-      __hash_len_16(__v.second, __w.second) + __x);
-}
-
-template <class _Tp, size_t = sizeof(_Tp) / sizeof(size_t)>
-struct __scalar_hash;
-
-template <class _Tp>
-struct __scalar_hash<_Tp, 0>
-    : public unary_function<_Tp, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(_Tp __v) const _NOEXCEPT
-    {
-        union
-        {
-            _Tp    __t;
-            size_t __a;
-        } __u;
-        __u.__a = 0;
-        __u.__t = __v;
-        return __u.__a;
-    }
-};
-
-template <class _Tp>
-struct __scalar_hash<_Tp, 1>
-    : public unary_function<_Tp, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(_Tp __v) const _NOEXCEPT
-    {
-        union
-        {
-            _Tp    __t;
-            size_t __a;
-        } __u;
-        __u.__t = __v;
-        return __u.__a;
-    }
-};
-
-template <class _Tp>
-struct __scalar_hash<_Tp, 2>
-    : public unary_function<_Tp, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(_Tp __v) const _NOEXCEPT
-    {
-        union
-        {
-            _Tp __t;
-            struct
-            {
-                size_t __a;
-                size_t __b;
-            } __s;
-        } __u;
-        __u.__t = __v;
-        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
-    }
-};
-
-template <class _Tp>
-struct __scalar_hash<_Tp, 3>
-    : public unary_function<_Tp, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(_Tp __v) const _NOEXCEPT
-    {
-        union
-        {
-            _Tp __t;
-            struct
-            {
-                size_t __a;
-                size_t __b;
-                size_t __c;
-            } __s;
-        } __u;
-        __u.__t = __v;
-        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
-    }
-};
-
-template <class _Tp>
-struct __scalar_hash<_Tp, 4>
-    : public unary_function<_Tp, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(_Tp __v) const _NOEXCEPT
-    {
-        union
-        {
-            _Tp __t;
-            struct
-            {
-                size_t __a;
-                size_t __b;
-                size_t __c;
-                size_t __d;
-            } __s;
-        } __u;
-        __u.__t = __v;
-        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
-    }
-};
-
-struct _PairT {
-  size_t first;
-  size_t second;
-};
-
-_LIBCPP_INLINE_VISIBILITY
-inline size_t __hash_combine(size_t __lhs, size_t __rhs) _NOEXCEPT {
-    typedef __scalar_hash<_PairT> _HashT;
-    const _PairT __p = {__lhs, __rhs};
-    return _HashT()(__p);
-}
-
-template<class _Tp>
-struct _LIBCPP_TEMPLATE_VIS hash<_Tp*>
-    : public unary_function<_Tp*, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(_Tp* __v) const _NOEXCEPT
-    {
-        union
-        {
-            _Tp* __t;
-            size_t __a;
-        } __u;
-        __u.__t = __v;
-        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
-    }
-};
-
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<bool>
-    : public unary_function<bool, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(bool __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<char>
-    : public unary_function<char, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<signed char>
-    : public unary_function<signed char, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(signed char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<unsigned char>
-    : public unary_function<unsigned char, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(unsigned char __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<char16_t>
-    : public unary_function<char16_t, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(char16_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<char32_t>
-    : public unary_function<char32_t, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(char32_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<wchar_t>
-    : public unary_function<wchar_t, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(wchar_t __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<short>
-    : public unary_function<short, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<unsigned short>
-    : public unary_function<unsigned short, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(unsigned short __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<int>
-    : public unary_function<int, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<unsigned int>
-    : public unary_function<unsigned int, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(unsigned int __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<long>
-    : public unary_function<long, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<unsigned long>
-    : public unary_function<unsigned long, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(unsigned long __v) const _NOEXCEPT {return static_cast<size_t>(__v);}
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<long long>
-    : public __scalar_hash<long long>
-{
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<unsigned long long>
-    : public __scalar_hash<unsigned long long>
-{
-};
-
-#ifndef _LIBCPP_HAS_NO_INT128
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<__int128_t>
-    : public __scalar_hash<__int128_t>
-{
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<__uint128_t>
-    : public __scalar_hash<__uint128_t>
-{
-};
-
-#endif
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<float>
-    : public __scalar_hash<float>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(float __v) const _NOEXCEPT
-    {
-        // -0.0 and 0.0 should return same hash
-       if (__v == 0.0)
-           return 0;
-        return __scalar_hash<float>::operator()(__v);
-    }
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<double>
-    : public __scalar_hash<double>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(double __v) const _NOEXCEPT
-    {
-        // -0.0 and 0.0 should return same hash
-       if (__v == 0.0)
-           return 0;
-        return __scalar_hash<double>::operator()(__v);
-    }
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<long double>
-    : public __scalar_hash<long double>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(long double __v) const _NOEXCEPT
-    {
-        // -0.0 and 0.0 should return same hash
-        if (__v == 0.0)
-            return 0;
-#if defined(__i386__)
-        // Zero out padding bits
-        union
-        {
-            long double __t;
-            struct
-            {
-                size_t __a;
-                size_t __b;
-                size_t __c;
-                size_t __d;
-            } __s;
-        } __u;
-        __u.__s.__a = 0;
-        __u.__s.__b = 0;
-        __u.__s.__c = 0;
-        __u.__s.__d = 0;
-        __u.__t = __v;
-        return __u.__s.__a ^ __u.__s.__b ^ __u.__s.__c ^ __u.__s.__d;
-#elif defined(__x86_64__)
-        // Zero out padding bits
-        union
-        {
-            long double __t;
-            struct
-            {
-                size_t __a;
-                size_t __b;
-            } __s;
-        } __u;
-        __u.__s.__a = 0;
-        __u.__s.__b = 0;
-        __u.__t = __v;
-        return __u.__s.__a ^ __u.__s.__b;
-#else
-        return __scalar_hash<long double>::operator()(__v);
-#endif
-    }
-};
-
-#if _LIBCPP_STD_VER > 11
-
-template <class _Tp, bool = is_enum<_Tp>::value>
-struct _LIBCPP_TEMPLATE_VIS __enum_hash
-    : public unary_function<_Tp, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(_Tp __v) const _NOEXCEPT
-    {
-        typedef typename underlying_type<_Tp>::type type;
-        return hash<type>{}(static_cast<type>(__v));
-    }
-};
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS __enum_hash<_Tp, false> {
-    __enum_hash() = delete;
-    __enum_hash(__enum_hash const&) = delete;
-    __enum_hash& operator=(__enum_hash const&) = delete;
-};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS hash : public __enum_hash<_Tp>
-{
-};
-#endif
-
-#if _LIBCPP_STD_VER > 14
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<nullptr_t>
-  : public unary_function<nullptr_t, size_t>
-{
-  _LIBCPP_INLINE_VISIBILITY
-  size_t operator()(nullptr_t) const _NOEXCEPT {
-    return 662607004ull;
-  }
-};
-#endif
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Key, class _Hash>
-using __check_hash_requirements = integral_constant<bool,
-    is_copy_constructible<_Hash>::value &&
-    is_move_constructible<_Hash>::value &&
-    __invokable_r<size_t, _Hash, _Key const&>::value
->;
-
-template <class _Key, class _Hash = std::hash<_Key> >
-using __has_enabled_hash = integral_constant<bool,
-    __check_hash_requirements<_Key, _Hash>::value &&
-    is_default_constructible<_Hash>::value
->;
-
-#if _LIBCPP_STD_VER > 14
-template <class _Type, class>
-using __enable_hash_helper_imp = _Type;
-
-template <class _Type, class ..._Keys>
-using __enable_hash_helper = __enable_hash_helper_imp<_Type,
-  typename enable_if<__all<__has_enabled_hash<_Keys>::value...>::value>::type
->;
-#else
-template <class _Type, class ...>
-using __enable_hash_helper = _Type;
-#endif
-
-#endif // !_LIBCPP_CXX03_LANG
-
-_LIBCPP_END_NAMESPACE_STD
-
-#endif  // _LIBCPP_UTILITY
diff --git a/lib/libcxx/include/valarray b/lib/libcxx/include/valarray
deleted file mode 100644
index 07f38c81150..00000000000
--- a/lib/libcxx/include/valarray
+++ /dev/null
@@ -1,4930 +0,0 @@
-// -*- C++ -*-
-//===-------------------------- valarray ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_VALARRAY
-#define _LIBCPP_VALARRAY
-
-/*
-    valarray synopsis
-
-namespace std
-{
-
-template<class T>
-class valarray
-{
-public:
-    typedef T value_type;
-
-    // construct/destroy:
-    valarray();
-    explicit valarray(size_t n);
-    valarray(const value_type& x, size_t n);
-    valarray(const value_type* px, size_t n);
-    valarray(const valarray& v);
-    valarray(valarray&& v) noexcept;
-    valarray(const slice_array<value_type>& sa);
-    valarray(const gslice_array<value_type>& ga);
-    valarray(const mask_array<value_type>& ma);
-    valarray(const indirect_array<value_type>& ia);
-    valarray(initializer_list<value_type> il);
-    ~valarray();
-
-    // assignment:
-    valarray& operator=(const valarray& v);
-    valarray& operator=(valarray&& v) noexcept;
-    valarray& operator=(initializer_list<value_type> il);
-    valarray& operator=(const value_type& x);
-    valarray& operator=(const slice_array<value_type>& sa);
-    valarray& operator=(const gslice_array<value_type>& ga);
-    valarray& operator=(const mask_array<value_type>& ma);
-    valarray& operator=(const indirect_array<value_type>& ia);
-
-    // element access:
-    const value_type& operator[](size_t i) const;
-    value_type&       operator[](size_t i);
-
-    // subset operations:
-    valarray                   operator[](slice s) const;
-    slice_array<value_type>    operator[](slice s);
-    valarray                   operator[](const gslice& gs) const;
-    gslice_array<value_type>   operator[](const gslice& gs);
-    valarray                   operator[](const valarray<bool>& vb) const;
-    mask_array<value_type>     operator[](const valarray<bool>& vb);
-    valarray                   operator[](const valarray<size_t>& vs) const;
-    indirect_array<value_type> operator[](const valarray<size_t>& vs);
-
-    // unary operators:
-    valarray       operator+() const;
-    valarray       operator-() const;
-    valarray       operator~() const;
-    valarray<bool> operator!() const;
-
-    // computed assignment:
-    valarray& operator*= (const value_type& x);
-    valarray& operator/= (const value_type& x);
-    valarray& operator%= (const value_type& x);
-    valarray& operator+= (const value_type& x);
-    valarray& operator-= (const value_type& x);
-    valarray& operator^= (const value_type& x);
-    valarray& operator&= (const value_type& x);
-    valarray& operator|= (const value_type& x);
-    valarray& operator<<=(const value_type& x);
-    valarray& operator>>=(const value_type& x);
-
-    valarray& operator*= (const valarray& v);
-    valarray& operator/= (const valarray& v);
-    valarray& operator%= (const valarray& v);
-    valarray& operator+= (const valarray& v);
-    valarray& operator-= (const valarray& v);
-    valarray& operator^= (const valarray& v);
-    valarray& operator|= (const valarray& v);
-    valarray& operator&= (const valarray& v);
-    valarray& operator<<=(const valarray& v);
-    valarray& operator>>=(const valarray& v);
-
-    // member functions:
-    void swap(valarray& v) noexcept;
-
-    size_t size() const;
-
-    value_type sum() const;
-    value_type min() const;
-    value_type max() const;
-
-    valarray shift (int i) const;
-    valarray cshift(int i) const;
-    valarray apply(value_type f(value_type)) const;
-    valarray apply(value_type f(const value_type&)) const;
-    void resize(size_t n, value_type x = value_type());
-};
-
-class slice
-{
-public:
-    slice();
-    slice(size_t start, size_t size, size_t stride);
-
-    size_t start()  const;
-    size_t size()   const;
-    size_t stride() const;
-};
-
-template <class T>
-class slice_array
-{
-public:
-    typedef T value_type;
-
-    const slice_array& operator=(const slice_array& sa) const;
-    void operator=  (const valarray<value_type>& v) const;
-    void operator*= (const valarray<value_type>& v) const;
-    void operator/= (const valarray<value_type>& v) const;
-    void operator%= (const valarray<value_type>& v) const;
-    void operator+= (const valarray<value_type>& v) const;
-    void operator-= (const valarray<value_type>& v) const;
-    void operator^= (const valarray<value_type>& v) const;
-    void operator&= (const valarray<value_type>& v) const;
-    void operator|= (const valarray<value_type>& v) const;
-    void operator<<=(const valarray<value_type>& v) const;
-    void operator>>=(const valarray<value_type>& v) const;
-
-    void operator=(const value_type& x) const;
-
-    slice_array() = delete;
-};
-
-class gslice
-{
-public:
-    gslice();
-    gslice(size_t start, const valarray<size_t>& size,
-                         const valarray<size_t>& stride);
-
-    size_t           start()  const;
-    valarray<size_t> size()   const;
-    valarray<size_t> stride() const;
-};
-
-template <class T>
-class gslice_array
-{
-public:
-    typedef T value_type;
-
-    void operator=  (const valarray<value_type>& v) const;
-    void operator*= (const valarray<value_type>& v) const;
-    void operator/= (const valarray<value_type>& v) const;
-    void operator%= (const valarray<value_type>& v) const;
-    void operator+= (const valarray<value_type>& v) const;
-    void operator-= (const valarray<value_type>& v) const;
-    void operator^= (const valarray<value_type>& v) const;
-    void operator&= (const valarray<value_type>& v) const;
-    void operator|= (const valarray<value_type>& v) const;
-    void operator<<=(const valarray<value_type>& v) const;
-    void operator>>=(const valarray<value_type>& v) const;
-
-    gslice_array(const gslice_array& ga);
-    ~gslice_array();
-    const gslice_array& operator=(const gslice_array& ga) const;
-    void operator=(const value_type& x) const;
-
-    gslice_array() = delete;
-};
-
-template <class T>
-class mask_array
-{
-public:
-    typedef T value_type;
-
-    void operator=  (const valarray<value_type>& v) const;
-    void operator*= (const valarray<value_type>& v) const;
-    void operator/= (const valarray<value_type>& v) const;
-    void operator%= (const valarray<value_type>& v) const;
-    void operator+= (const valarray<value_type>& v) const;
-    void operator-= (const valarray<value_type>& v) const;
-    void operator^= (const valarray<value_type>& v) const;
-    void operator&= (const valarray<value_type>& v) const;
-    void operator|= (const valarray<value_type>& v) const;
-    void operator<<=(const valarray<value_type>& v) const;
-    void operator>>=(const valarray<value_type>& v) const;
-
-    mask_array(const mask_array& ma);
-    ~mask_array();
-    const mask_array& operator=(const mask_array& ma) const;
-    void operator=(const value_type& x) const;
-
-    mask_array() = delete;
-};
-
-template <class T>
-class indirect_array
-{
-public:
-    typedef T value_type;
-
-    void operator=  (const valarray<value_type>& v) const;
-    void operator*= (const valarray<value_type>& v) const;
-    void operator/= (const valarray<value_type>& v) const;
-    void operator%= (const valarray<value_type>& v) const;
-    void operator+= (const valarray<value_type>& v) const;
-    void operator-= (const valarray<value_type>& v) const;
-    void operator^= (const valarray<value_type>& v) const;
-    void operator&= (const valarray<value_type>& v) const;
-    void operator|= (const valarray<value_type>& v) const;
-    void operator<<=(const valarray<value_type>& v) const;
-    void operator>>=(const valarray<value_type>& v) const;
-
-    indirect_array(const indirect_array& ia);
-    ~indirect_array();
-    const indirect_array& operator=(const indirect_array& ia) const;
-    void operator=(const value_type& x) const;
-
-    indirect_array() = delete;
-};
-
-template<class T> void swap(valarray<T>& x, valarray<T>& y) noexcept;
-
-template<class T> valarray<T> operator* (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator* (const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator* (const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> operator/ (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator/ (const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator/ (const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> operator% (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator% (const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator% (const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> operator+ (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator+ (const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator+ (const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> operator- (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator- (const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator- (const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> operator^ (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator^ (const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator^ (const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> operator& (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator& (const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator& (const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> operator| (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator| (const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator| (const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> operator<<(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator<<(const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator<<(const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> operator>>(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> operator>>(const valarray<T>& x, const T& y);
-template<class T> valarray<T> operator>>(const T& x, const valarray<T>& y);
-
-template<class T> valarray<bool> operator&&(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<bool> operator&&(const valarray<T>& x, const T& y);
-template<class T> valarray<bool> operator&&(const T& x, const valarray<T>& y);
-
-template<class T> valarray<bool> operator||(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<bool> operator||(const valarray<T>& x, const T& y);
-template<class T> valarray<bool> operator||(const T& x, const valarray<T>& y);
-
-template<class T> valarray<bool> operator==(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<bool> operator==(const valarray<T>& x, const T& y);
-template<class T> valarray<bool> operator==(const T& x, const valarray<T>& y);
-
-template<class T> valarray<bool> operator!=(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<bool> operator!=(const valarray<T>& x, const T& y);
-template<class T> valarray<bool> operator!=(const T& x, const valarray<T>& y);
-
-template<class T> valarray<bool> operator< (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<bool> operator< (const valarray<T>& x, const T& y);
-template<class T> valarray<bool> operator< (const T& x, const valarray<T>& y);
-
-template<class T> valarray<bool> operator> (const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<bool> operator> (const valarray<T>& x, const T& y);
-template<class T> valarray<bool> operator> (const T& x, const valarray<T>& y);
-
-template<class T> valarray<bool> operator<=(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<bool> operator<=(const valarray<T>& x, const T& y);
-template<class T> valarray<bool> operator<=(const T& x, const valarray<T>& y);
-
-template<class T> valarray<bool> operator>=(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<bool> operator>=(const valarray<T>& x, const T& y);
-template<class T> valarray<bool> operator>=(const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> abs (const valarray<T>& x);
-template<class T> valarray<T> acos (const valarray<T>& x);
-template<class T> valarray<T> asin (const valarray<T>& x);
-template<class T> valarray<T> atan (const valarray<T>& x);
-
-template<class T> valarray<T> atan2(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> atan2(const valarray<T>& x, const T& y);
-template<class T> valarray<T> atan2(const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> cos (const valarray<T>& x);
-template<class T> valarray<T> cosh (const valarray<T>& x);
-template<class T> valarray<T> exp (const valarray<T>& x);
-template<class T> valarray<T> log (const valarray<T>& x);
-template<class T> valarray<T> log10(const valarray<T>& x);
-
-template<class T> valarray<T> pow(const valarray<T>& x, const valarray<T>& y);
-template<class T> valarray<T> pow(const valarray<T>& x, const T& y);
-template<class T> valarray<T> pow(const T& x, const valarray<T>& y);
-
-template<class T> valarray<T> sin (const valarray<T>& x);
-template<class T> valarray<T> sinh (const valarray<T>& x);
-template<class T> valarray<T> sqrt (const valarray<T>& x);
-template<class T> valarray<T> tan (const valarray<T>& x);
-template<class T> valarray<T> tanh (const valarray<T>& x);
-
-template <class T> unspecified1 begin(valarray<T>& v);
-template <class T> unspecified2 begin(const valarray<T>& v);
-template <class T> unspecified1 end(valarray<T>& v);
-template <class T> unspecified2 end(const valarray<T>& v);
-
-}  // std
-
-*/
-
-#include <__config>
-#include <cstddef>
-#include <cmath>
-#include <initializer_list>
-#include <algorithm>
-#include <functional>
-#include <new>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template<class _Tp> class _LIBCPP_TEMPLATE_VIS valarray;
-
-class _LIBCPP_TEMPLATE_VIS slice
-{
-    size_t __start_;
-    size_t __size_;
-    size_t __stride_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    slice()
-        : __start_(0),
-          __size_(0),
-          __stride_(0)
-          {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    slice(size_t __start, size_t __size, size_t __stride)
-        : __start_(__start),
-          __size_(__size),
-          __stride_(__stride)
-          {}
-
-    _LIBCPP_INLINE_VISIBILITY size_t start()  const {return __start_;}
-    _LIBCPP_INLINE_VISIBILITY size_t size()   const {return __size_;}
-    _LIBCPP_INLINE_VISIBILITY size_t stride() const {return __stride_;}
-};
-
-template <class _Tp> class _LIBCPP_TEMPLATE_VIS slice_array;
-class _LIBCPP_TYPE_VIS gslice;
-template <class _Tp> class _LIBCPP_TEMPLATE_VIS gslice_array;
-template <class _Tp> class _LIBCPP_TEMPLATE_VIS mask_array;
-template <class _Tp> class _LIBCPP_TEMPLATE_VIS indirect_array;
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp*
-begin(valarray<_Tp>& __v);
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-const _Tp*
-begin(const valarray<_Tp>& __v);
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-_Tp*
-end(valarray<_Tp>& __v);
-
-template <class _Tp>
-_LIBCPP_INLINE_VISIBILITY
-const _Tp*
-end(const valarray<_Tp>& __v);
-
-template <class _Op, class _A0>
-struct _UnaryOp
-{
-    typedef typename _Op::result_type result_type;
-    typedef typename _A0::value_type value_type;
-
-    _Op __op_;
-    _A0 __a0_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _UnaryOp(const _Op& __op, const _A0& __a0) : __op_(__op), __a0_(__a0) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator[](size_t __i) const {return __op_(__a0_[__i]);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __a0_.size();}
-};
-
-template <class _Op, class _A0, class _A1>
-struct _BinaryOp
-{
-    typedef typename _Op::result_type result_type;
-    typedef typename _A0::value_type value_type;
-
-    _Op __op_;
-    _A0 __a0_;
-    _A1 __a1_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _BinaryOp(const _Op& __op, const _A0& __a0, const _A1& __a1)
-        : __op_(__op), __a0_(__a0), __a1_(__a1) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type operator[](size_t __i) const {return __op_(__a0_[__i], __a1_[__i]);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __a0_.size();}
-};
-
-template <class _Tp>
-class __scalar_expr
-{
-public:
-    typedef _Tp        value_type;
-    typedef const _Tp& result_type;
-private:
-    const value_type& __t_;
-    size_t __s_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __scalar_expr(const value_type& __t, size_t __s) : __t_(__t), __s_(__s) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator[](size_t) const {return __t_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __s_;}
-};
-
-template <class _Tp>
-struct __unary_plus : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return +__x;}
-};
-
-template <class _Tp>
-struct __bit_not  : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return ~__x;}
-};
-
-template <class _Tp>
-struct __bit_shift_left : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x << __y;}
-};
-
-template <class _Tp>
-struct __bit_shift_right : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return __x >> __y;}
-};
-
-template <class _Tp, class _Fp>
-struct __apply_expr   : unary_function<_Tp, _Tp>
-{
-private:
-    _Fp __f_;
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __apply_expr(_Fp __f) : __f_(__f) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return __f_(__x);}
-};
-
-template <class _Tp>
-struct __abs_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return abs(__x);}
-};
-
-template <class _Tp>
-struct __acos_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return acos(__x);}
-};
-
-template <class _Tp>
-struct __asin_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return asin(__x);}
-};
-
-template <class _Tp>
-struct __atan_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return atan(__x);}
-};
-
-template <class _Tp>
-struct __atan2_expr : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return atan2(__x, __y);}
-};
-
-template <class _Tp>
-struct __cos_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return cos(__x);}
-};
-
-template <class _Tp>
-struct __cosh_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return cosh(__x);}
-};
-
-template <class _Tp>
-struct __exp_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return exp(__x);}
-};
-
-template <class _Tp>
-struct __log_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return log(__x);}
-};
-
-template <class _Tp>
-struct __log10_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return log10(__x);}
-};
-
-template <class _Tp>
-struct __pow_expr : binary_function<_Tp, _Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x, const _Tp& __y) const
-        {return pow(__x, __y);}
-};
-
-template <class _Tp>
-struct __sin_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return sin(__x);}
-};
-
-template <class _Tp>
-struct __sinh_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return sinh(__x);}
-};
-
-template <class _Tp>
-struct __sqrt_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return sqrt(__x);}
-};
-
-template <class _Tp>
-struct __tan_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return tan(__x);}
-};
-
-template <class _Tp>
-struct __tanh_expr : unary_function<_Tp, _Tp>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    _Tp operator()(const _Tp& __x) const
-        {return tanh(__x);}
-};
-
-template <class _ValExpr>
-class __slice_expr
-{
-    typedef typename remove_reference<_ValExpr>::type  _RmExpr;
-public:
-    typedef typename _RmExpr::value_type value_type;
-    typedef value_type result_type;
-
-private:
-    _ValExpr __expr_;
-    size_t __start_;
-    size_t __size_;
-    size_t __stride_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __slice_expr(const slice& __sl, const _RmExpr& __e)
-        : __expr_(__e),
-          __start_(__sl.start()),
-          __size_(__sl.size()),
-          __stride_(__sl.stride())
-        {}
-public:
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator[](size_t __i) const
-        {return __expr_[__start_ + __i * __stride_];}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __size_;}
-
-    template <class> friend class _LIBCPP_TEMPLATE_VIS valarray;
-};
-
-template <class _ValExpr>
-class __mask_expr;
-
-template <class _ValExpr>
-class __indirect_expr;
-
-template <class _ValExpr>
-class __shift_expr
-{
-    typedef typename remove_reference<_ValExpr>::type  _RmExpr;
-public:
-    typedef typename _RmExpr::value_type value_type;
-    typedef value_type result_type;
-
-private:
-    _ValExpr __expr_;
-    size_t __size_;
-    ptrdiff_t __ul_;
-    ptrdiff_t __sn_;
-    ptrdiff_t __n_;
-    static const ptrdiff_t _Np = static_cast<ptrdiff_t>(
-                                    sizeof(ptrdiff_t) * __CHAR_BIT__ - 1);
-
-    _LIBCPP_INLINE_VISIBILITY
-    __shift_expr(int __n, const _RmExpr& __e)
-        : __expr_(__e),
-          __size_(__e.size()),
-          __n_(__n)
-        {
-            ptrdiff_t __neg_n = static_cast<ptrdiff_t>(__n_ >> _Np);
-            __sn_ = __neg_n | static_cast<ptrdiff_t>(static_cast<size_t>(-__n_) >> _Np);
-            __ul_ = ((__size_ - __n_) & ~__neg_n) | ((__n_ + 1) & __neg_n);
-        }
-public:
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator[](size_t __j) const
-        {
-            ptrdiff_t __i = static_cast<ptrdiff_t>(__j);
-            ptrdiff_t __m = (__sn_ * __i - __ul_) >> _Np;
-            return (__expr_[(__i + __n_) & __m] & __m) | (value_type() & ~__m);
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __size_;}
-
-    template <class> friend class __val_expr;
-};
-
-template <class _ValExpr>
-class __cshift_expr
-{
-    typedef typename remove_reference<_ValExpr>::type  _RmExpr;
-public:
-    typedef typename _RmExpr::value_type value_type;
-    typedef value_type result_type;
-
-private:
-    _ValExpr __expr_;
-    size_t __size_;
-    size_t __m_;
-    size_t __o1_;
-    size_t __o2_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __cshift_expr(int __n, const _RmExpr& __e)
-        : __expr_(__e),
-          __size_(__e.size())
-        {
-            __n %= static_cast<int>(__size_);
-            if (__n >= 0)
-            {
-                __m_ = __size_ - __n;
-                __o1_ = __n;
-                __o2_ = __n - __size_;
-            }
-            else
-            {
-                __m_ = -__n;
-                __o1_ = __n + __size_;
-                __o2_ = __n;
-            }
-        }
-public:
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator[](size_t __i) const
-        {
-            if (__i < __m_)
-                return __expr_[__i + __o1_];
-            return __expr_[__i + __o2_];
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __size_;}
-
-    template <class> friend class __val_expr;
-};
-
-template<class _ValExpr>
-class __val_expr;
-
-template<class _ValExpr>
-struct __is_val_expr : false_type {};
-
-template<class _ValExpr>
-struct __is_val_expr<__val_expr<_ValExpr> > : true_type {};
-
-template<class _Tp>
-struct __is_val_expr<valarray<_Tp> > : true_type {};
-
-template<class _Tp>
-class _LIBCPP_TEMPLATE_VIS valarray
-{
-public:
-    typedef _Tp value_type;
-    typedef _Tp result_type;
-
-private:
-    value_type* __begin_;
-    value_type* __end_;
-
-public:
-    // construct/destroy:
-    _LIBCPP_INLINE_VISIBILITY
-    valarray() : __begin_(0), __end_(0) {}
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    explicit valarray(size_t __n);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray(const value_type& __x, size_t __n);
-    valarray(const value_type* __p, size_t __n);
-    valarray(const valarray& __v);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    valarray(valarray&& __v) _NOEXCEPT;
-    valarray(initializer_list<value_type> __il);
-#endif  // _LIBCPP_CXX03_LANG
-    valarray(const slice_array<value_type>& __sa);
-    valarray(const gslice_array<value_type>& __ga);
-    valarray(const mask_array<value_type>& __ma);
-    valarray(const indirect_array<value_type>& __ia);
-    inline _LIBCPP_HIDE_FROM_ABI_AFTER_V1
-    ~valarray();
-
-    // assignment:
-    valarray& operator=(const valarray& __v);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator=(valarray&& __v) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator=(initializer_list<value_type>);
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator=(const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator=(const slice_array<value_type>& __sa);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator=(const gslice_array<value_type>& __ga);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator=(const mask_array<value_type>& __ma);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator=(const indirect_array<value_type>& __ia);
-    template <class _ValExpr>
-        _LIBCPP_INLINE_VISIBILITY
-        valarray& operator=(const __val_expr<_ValExpr>& __v);
-
-    // element access:
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type& operator[](size_t __i) const {return __begin_[__i];}
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type&       operator[](size_t __i)       {return __begin_[__i];}
-
-    // subset operations:
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__slice_expr<const valarray&> >    operator[](slice __s) const;
-    _LIBCPP_INLINE_VISIBILITY
-    slice_array<value_type>                       operator[](slice __s);
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__indirect_expr<const valarray&> > operator[](const gslice& __gs) const;
-    _LIBCPP_INLINE_VISIBILITY
-    gslice_array<value_type>   operator[](const gslice& __gs);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__indirect_expr<const valarray&> > operator[](gslice&& __gs) const;
-    _LIBCPP_INLINE_VISIBILITY
-    gslice_array<value_type>                      operator[](gslice&& __gs);
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__mask_expr<const valarray&> >     operator[](const valarray<bool>& __vb) const;
-    _LIBCPP_INLINE_VISIBILITY
-    mask_array<value_type>                        operator[](const valarray<bool>& __vb);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__mask_expr<const valarray&> >     operator[](valarray<bool>&& __vb) const;
-    _LIBCPP_INLINE_VISIBILITY
-    mask_array<value_type>                        operator[](valarray<bool>&& __vb);
-#endif  // _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__indirect_expr<const valarray&> > operator[](const valarray<size_t>& __vs) const;
-    _LIBCPP_INLINE_VISIBILITY
-    indirect_array<value_type>                    operator[](const valarray<size_t>& __vs);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__indirect_expr<const valarray&> > operator[](valarray<size_t>&& __vs) const;
-    _LIBCPP_INLINE_VISIBILITY
-    indirect_array<value_type>                    operator[](valarray<size_t>&& __vs);
-#endif  // _LIBCPP_CXX03_LANG
-
-    // unary operators:
-    valarray       operator+() const;
-    valarray       operator-() const;
-    valarray       operator~() const;
-    valarray<bool> operator!() const;
-
-    // computed assignment:
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator*= (const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator/= (const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator%= (const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator+= (const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator-= (const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator^= (const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator&= (const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator|= (const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator<<=(const value_type& __x);
-    _LIBCPP_INLINE_VISIBILITY
-    valarray& operator>>=(const value_type& __x);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator*= (const _Expr& __v);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator/= (const _Expr& __v);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator%= (const _Expr& __v);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator+= (const _Expr& __v);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator-= (const _Expr& __v);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator^= (const _Expr& __v);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator|= (const _Expr& __v);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator&= (const _Expr& __v);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator<<= (const _Expr& __v);
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        valarray&
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator>>= (const _Expr& __v);
-
-    // member functions:
-    _LIBCPP_INLINE_VISIBILITY
-    void swap(valarray& __v) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return static_cast<size_t>(__end_ - __begin_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type sum() const;
-    _LIBCPP_INLINE_VISIBILITY
-    value_type min() const;
-    _LIBCPP_INLINE_VISIBILITY
-    value_type max() const;
-
-    valarray shift (int __i) const;
-    valarray cshift(int __i) const;
-    valarray apply(value_type __f(value_type)) const;
-    valarray apply(value_type __f(const value_type&)) const;
-    void     resize(size_t __n, value_type __x = value_type());
-
-private:
-    template <class> friend class _LIBCPP_TEMPLATE_VIS valarray;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS slice_array;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS gslice_array;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS mask_array;
-    template <class> friend class __mask_expr;
-    template <class> friend class _LIBCPP_TEMPLATE_VIS indirect_array;
-    template <class> friend class __indirect_expr;
-    template <class> friend class __val_expr;
-
-    template <class _Up>
-    friend
-    _Up*
-    begin(valarray<_Up>& __v);
-
-    template <class _Up>
-    friend
-    const _Up*
-    begin(const valarray<_Up>& __v);
-
-    template <class _Up>
-    friend
-    _Up*
-    end(valarray<_Up>& __v);
-
-    template <class _Up>
-    friend
-    const _Up*
-    end(const valarray<_Up>& __v);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __clear(size_t __capacity);
-    valarray& __assign_range(const value_type* __f, const value_type* __l);
-};
-
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS valarray<size_t>::valarray(size_t))
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS valarray<size_t>::~valarray())
-_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS void valarray<size_t>::resize(size_t, size_t))
-
-template <class _Op, class _Tp>
-struct _UnaryOp<_Op, valarray<_Tp> >
-{
-    typedef typename _Op::result_type result_type;
-    typedef _Tp value_type;
-
-    _Op __op_;
-    const valarray<_Tp>& __a0_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _UnaryOp(const _Op& __op, const valarray<_Tp>& __a0) : __op_(__op), __a0_(__a0) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator[](size_t __i) const {return __op_(__a0_[__i]);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __a0_.size();}
-};
-
-template <class _Op, class _Tp, class _A1>
-struct _BinaryOp<_Op, valarray<_Tp>, _A1>
-{
-    typedef typename _Op::result_type result_type;
-    typedef _Tp value_type;
-
-    _Op __op_;
-    const valarray<_Tp>& __a0_;
-    _A1 __a1_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _BinaryOp(const _Op& __op, const valarray<_Tp>& __a0, const _A1& __a1)
-        : __op_(__op), __a0_(__a0), __a1_(__a1) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type operator[](size_t __i) const {return __op_(__a0_[__i], __a1_[__i]);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __a0_.size();}
-};
-
-template <class _Op, class _A0, class _Tp>
-struct _BinaryOp<_Op, _A0, valarray<_Tp> >
-{
-    typedef typename _Op::result_type result_type;
-    typedef _Tp value_type;
-
-    _Op __op_;
-    _A0 __a0_;
-    const valarray<_Tp>& __a1_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _BinaryOp(const _Op& __op, const _A0& __a0, const valarray<_Tp>& __a1)
-        : __op_(__op), __a0_(__a0), __a1_(__a1) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type operator[](size_t __i) const {return __op_(__a0_[__i], __a1_[__i]);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __a0_.size();}
-};
-
-template <class _Op, class _Tp>
-struct _BinaryOp<_Op, valarray<_Tp>, valarray<_Tp> >
-{
-    typedef typename _Op::result_type result_type;
-    typedef _Tp value_type;
-
-    _Op __op_;
-    const valarray<_Tp>& __a0_;
-    const valarray<_Tp>& __a1_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    _BinaryOp(const _Op& __op, const valarray<_Tp>& __a0, const valarray<_Tp>& __a1)
-        : __op_(__op), __a0_(__a0), __a1_(__a1) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type operator[](size_t __i) const {return __op_(__a0_[__i], __a1_[__i]);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __a0_.size();}
-};
-
-// slice_array
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS slice_array
-{
-public:
-    typedef _Tp value_type;
-
-private:
-    value_type* __vp_;
-    size_t __size_;
-    size_t __stride_;
-
-public:
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator*=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator/=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator%=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator+=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator-=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator^=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator&=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator|=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator<<=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator>>=(const _Expr& __v) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    const slice_array& operator=(const slice_array& __sa) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator=(const value_type& __x) const;
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    slice_array(const slice& __sl, const valarray<value_type>& __v)
-        : __vp_(const_cast<value_type*>(__v.__begin_ + __sl.start())),
-          __size_(__sl.size()),
-          __stride_(__sl.stride())
-        {}
-
-    template <class> friend class valarray;
-    template <class> friend class sliceExpr;
-};
-
-template <class _Tp>
-inline
-const slice_array<_Tp>&
-slice_array<_Tp>::operator=(const slice_array& __sa) const
-{
-    value_type* __t = __vp_;
-    const value_type* __s = __sa.__vp_;
-    for (size_t __n = __size_; __n; --__n, __t += __stride_, __s += __sa.__stride_)
-        *__t = *__s;
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t = __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator*=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t *= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator/=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t /= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator%=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t %= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator+=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t += __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator-=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t -= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator^=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t ^= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator&=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t &= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator|=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t |= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator<<=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t <<= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-slice_array<_Tp>::operator>>=(const _Expr& __v) const
-{
-    value_type* __t = __vp_;
-    for (size_t __i = 0; __i < __size_; ++__i, __t += __stride_)
-        *__t >>= __v[__i];
-}
-
-template <class _Tp>
-inline
-void
-slice_array<_Tp>::operator=(const value_type& __x) const
-{
-    value_type* __t = __vp_;
-    for (size_t __n = __size_; __n; --__n, __t += __stride_)
-        *__t = __x;
-}
-
-// gslice
-
-class _LIBCPP_TYPE_VIS gslice
-{
-    valarray<size_t> __size_;
-    valarray<size_t> __stride_;
-    valarray<size_t> __1d_;
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    gslice() {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    gslice(size_t __start, const valarray<size_t>& __size,
-                           const valarray<size_t>& __stride)
-        : __size_(__size),
-          __stride_(__stride)
-        {__init(__start);}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    gslice(size_t __start, const valarray<size_t>&  __size,
-                                 valarray<size_t>&& __stride)
-        : __size_(__size),
-          __stride_(move(__stride))
-        {__init(__start);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    gslice(size_t __start,       valarray<size_t>&& __size,
-                           const valarray<size_t>&  __stride)
-        : __size_(move(__size)),
-          __stride_(__stride)
-        {__init(__start);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    gslice(size_t __start,       valarray<size_t>&& __size,
-                                 valarray<size_t>&& __stride)
-        : __size_(move(__size)),
-          __stride_(move(__stride))
-        {__init(__start);}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-//  gslice(const gslice&)            = default;
-//  gslice(gslice&&)                 = default;
-//  gslice& operator=(const gslice&) = default;
-//  gslice& operator=(gslice&&)      = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t           start()  const {return __1d_.size() ? __1d_[0] : 0;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    valarray<size_t> size()   const {return __size_;}
-
-    _LIBCPP_INLINE_VISIBILITY
-    valarray<size_t> stride() const {return __stride_;}
-
-private:
-    void __init(size_t __start);
-
-    template <class> friend class gslice_array;
-    template <class> friend class valarray;
-    template <class> friend class __val_expr;
-};
-
-// gslice_array
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS gslice_array
-{
-public:
-    typedef _Tp value_type;
-
-private:
-    value_type*      __vp_;
-    valarray<size_t> __1d_;
-
-public:
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator*=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator/=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator%=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator+=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator-=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator^=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator&=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator|=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator<<=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator>>=(const _Expr& __v) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    const gslice_array& operator=(const gslice_array& __ga) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator=(const value_type& __x) const;
-
-//  gslice_array(const gslice_array&)            = default;
-//  gslice_array(gslice_array&&)                 = default;
-//  gslice_array& operator=(const gslice_array&) = default;
-//  gslice_array& operator=(gslice_array&&)      = default;
-
-private:
-    gslice_array(const gslice& __gs, const valarray<value_type>& __v)
-        : __vp_(const_cast<value_type*>(__v.__begin_)),
-          __1d_(__gs.__1d_)
-        {}
-
-#ifndef _LIBCPP_CXX03_LANG
-    gslice_array(gslice&& __gs, const valarray<value_type>& __v)
-        : __vp_(const_cast<value_type*>(__v.__begin_)),
-          __1d_(move(__gs.__1d_))
-        {}
-#endif  // _LIBCPP_CXX03_LANG
-
-    template <class> friend class valarray;
-};
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] = __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator*=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] *= __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator/=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] /= __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator%=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] %= __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator+=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] += __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator-=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] -= __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator^=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] ^= __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator&=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] &= __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator|=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] |= __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator<<=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] <<= __v[__j];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-gslice_array<_Tp>::operator>>=(const _Expr& __v) const
-{
-    typedef const size_t* _Ip;
-    size_t __j = 0;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i, ++__j)
-        __vp_[*__i] >>= __v[__j];
-}
-
-template <class _Tp>
-inline
-const gslice_array<_Tp>&
-gslice_array<_Tp>::operator=(const gslice_array& __ga) const
-{
-    typedef const size_t* _Ip;
-    const value_type* __s = __ga.__vp_;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_, __j = __ga.__1d_.__begin_;
-            __i != __e; ++__i, ++__j)
-        __vp_[*__i] = __s[*__j];
-    return *this;
-}
-
-template <class _Tp>
-inline
-void
-gslice_array<_Tp>::operator=(const value_type& __x) const
-{
-    typedef const size_t* _Ip;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i)
-        __vp_[*__i] = __x;
-}
-
-// mask_array
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS mask_array
-{
-public:
-    typedef _Tp value_type;
-
-private:
-    value_type*      __vp_;
-    valarray<size_t> __1d_;
-
-public:
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator*=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator/=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator%=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator+=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator-=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator^=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator&=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator|=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator<<=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator>>=(const _Expr& __v) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    const mask_array& operator=(const mask_array& __ma) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator=(const value_type& __x) const;
-
-//  mask_array(const mask_array&)            = default;
-//  mask_array(mask_array&&)                 = default;
-//  mask_array& operator=(const mask_array&) = default;
-//  mask_array& operator=(mask_array&&)      = default;
-
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    mask_array(const valarray<bool>& __vb, const valarray<value_type>& __v)
-        : __vp_(const_cast<value_type*>(__v.__begin_)),
-          __1d_(static_cast<size_t>(count(__vb.__begin_, __vb.__end_, true)))
-          {
-              size_t __j = 0;
-              for (size_t __i = 0; __i < __vb.size(); ++__i)
-                  if (__vb[__i])
-                      __1d_[__j++] = __i;
-          }
-
-    template <class> friend class valarray;
-};
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] = __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator*=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] *= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator/=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] /= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator%=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] %= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator+=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] += __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator-=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] -= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator^=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] ^= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator&=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] &= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator|=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] |= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator<<=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] <<= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-mask_array<_Tp>::operator>>=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] >>= __v[__i];
-}
-
-template <class _Tp>
-inline
-const mask_array<_Tp>&
-mask_array<_Tp>::operator=(const mask_array& __ma) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] = __ma.__vp_[__1d_[__i]];
-    return *this;
-}
-
-template <class _Tp>
-inline
-void
-mask_array<_Tp>::operator=(const value_type& __x) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] = __x;
-}
-
-template <class _ValExpr>
-class __mask_expr
-{
-    typedef typename remove_reference<_ValExpr>::type  _RmExpr;
-public:
-    typedef typename _RmExpr::value_type value_type;
-    typedef value_type result_type;
-
-private:
-    _ValExpr __expr_;
-    valarray<size_t> __1d_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __mask_expr(const valarray<bool>& __vb, const _RmExpr& __e)
-        : __expr_(__e),
-          __1d_(static_cast<size_t>(count(__vb.__begin_, __vb.__end_, true)))
-          {
-              size_t __j = 0;
-              for (size_t __i = 0; __i < __vb.size(); ++__i)
-                  if (__vb[__i])
-                      __1d_[__j++] = __i;
-          }
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator[](size_t __i) const
-        {return __expr_[__1d_[__i]];}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __1d_.size();}
-
-    template <class> friend class valarray;
-};
-
-// indirect_array
-
-template <class _Tp>
-class _LIBCPP_TEMPLATE_VIS indirect_array
-{
-public:
-    typedef _Tp value_type;
-
-private:
-    value_type*      __vp_;
-    valarray<size_t> __1d_;
-
-public:
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator*=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator/=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator%=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator+=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator-=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator^=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator&=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator|=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator<<=(const _Expr& __v) const;
-
-    template <class _Expr>
-    typename enable_if
-    <
-        __is_val_expr<_Expr>::value,
-        void
-    >::type
-    _LIBCPP_INLINE_VISIBILITY
-    operator>>=(const _Expr& __v) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    const indirect_array& operator=(const indirect_array& __ia) const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void operator=(const value_type& __x) const;
-
-//  indirect_array(const indirect_array&)            = default;
-//  indirect_array(indirect_array&&)                 = default;
-//  indirect_array& operator=(const indirect_array&) = default;
-//  indirect_array& operator=(indirect_array&&)      = default;
-
-private:
-     _LIBCPP_INLINE_VISIBILITY
-   indirect_array(const valarray<size_t>& __ia, const valarray<value_type>& __v)
-        : __vp_(const_cast<value_type*>(__v.__begin_)),
-          __1d_(__ia)
-        {}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    indirect_array(valarray<size_t>&& __ia, const valarray<value_type>& __v)
-        : __vp_(const_cast<value_type*>(__v.__begin_)),
-          __1d_(move(__ia))
-        {}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-    template <class> friend class valarray;
-};
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] = __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator*=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] *= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator/=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] /= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator%=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] %= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator+=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] += __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator-=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] -= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator^=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] ^= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator&=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] &= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator|=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] |= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator<<=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] <<= __v[__i];
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    void
->::type
-indirect_array<_Tp>::operator>>=(const _Expr& __v) const
-{
-    size_t __n = __1d_.size();
-    for (size_t __i = 0; __i < __n; ++__i)
-        __vp_[__1d_[__i]] >>= __v[__i];
-}
-
-template <class _Tp>
-inline
-const indirect_array<_Tp>&
-indirect_array<_Tp>::operator=(const indirect_array& __ia) const
-{
-    typedef const size_t* _Ip;
-    const value_type* __s = __ia.__vp_;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_, __j = __ia.__1d_.__begin_;
-            __i != __e; ++__i, ++__j)
-        __vp_[*__i] = __s[*__j];
-    return *this;
-}
-
-template <class _Tp>
-inline
-void
-indirect_array<_Tp>::operator=(const value_type& __x) const
-{
-    typedef const size_t* _Ip;
-    for (_Ip __i = __1d_.__begin_, __e = __1d_.__end_; __i != __e; ++__i)
-        __vp_[*__i] = __x;
-}
-
-template <class _ValExpr>
-class __indirect_expr
-{
-    typedef typename remove_reference<_ValExpr>::type  _RmExpr;
-public:
-    typedef typename _RmExpr::value_type value_type;
-    typedef value_type result_type;
-
-private:
-    _ValExpr __expr_;
-    valarray<size_t> __1d_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    __indirect_expr(const valarray<size_t>& __ia, const _RmExpr& __e)
-        : __expr_(__e),
-          __1d_(__ia)
-          {}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    __indirect_expr(valarray<size_t>&& __ia, const _RmExpr& __e)
-        : __expr_(__e),
-          __1d_(move(__ia))
-          {}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator[](size_t __i) const
-        {return __expr_[__1d_[__i]];}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __1d_.size();}
-
-    template <class> friend class _LIBCPP_TEMPLATE_VIS valarray;
-};
-
-template<class _ValExpr>
-class __val_expr
-{
-    typedef typename remove_reference<_ValExpr>::type  _RmExpr;
-
-    _ValExpr __expr_;
-public:
-    typedef typename _RmExpr::value_type value_type;
-    typedef typename _RmExpr::result_type result_type;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit __val_expr(const _RmExpr& __e) : __expr_(__e) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type operator[](size_t __i) const
-        {return __expr_[__i];}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__slice_expr<_ValExpr> > operator[](slice __s) const
-        {return __val_expr<__slice_expr<_ValExpr> >(__expr_, __s);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__indirect_expr<_ValExpr> > operator[](const gslice& __gs) const
-        {return __val_expr<__indirect_expr<_ValExpr> >(__expr_, __gs.__1d_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__mask_expr<_ValExpr> > operator[](const valarray<bool>& __vb) const
-        {return __val_expr<__mask_expr<_ValExpr> >(__expr_, __vb);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__indirect_expr<_ValExpr> > operator[](const valarray<size_t>& __vs) const
-        {return __val_expr<__indirect_expr<_ValExpr> >(__expr_, __vs);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<_UnaryOp<__unary_plus<value_type>, _ValExpr> >
-    operator+() const
-    {
-        typedef _UnaryOp<__unary_plus<value_type>, _ValExpr> _NewExpr;
-        return __val_expr<_NewExpr>(_NewExpr(__unary_plus<value_type>(), __expr_));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<_UnaryOp<negate<value_type>, _ValExpr> >
-    operator-() const
-    {
-        typedef _UnaryOp<negate<value_type>, _ValExpr> _NewExpr;
-        return __val_expr<_NewExpr>(_NewExpr(negate<value_type>(), __expr_));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<_UnaryOp<__bit_not<value_type>, _ValExpr> >
-    operator~() const
-    {
-        typedef _UnaryOp<__bit_not<value_type>, _ValExpr> _NewExpr;
-        return __val_expr<_NewExpr>(_NewExpr(__bit_not<value_type>(), __expr_));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<_UnaryOp<logical_not<value_type>, _ValExpr> >
-    operator!() const
-    {
-        typedef _UnaryOp<logical_not<value_type>, _ValExpr> _NewExpr;
-        return __val_expr<_NewExpr>(_NewExpr(logical_not<value_type>(), __expr_));
-    }
-
-    operator valarray<result_type>() const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_t size() const {return __expr_.size();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type sum() const
-    {
-        size_t __n = __expr_.size();
-        result_type __r = __n ? __expr_[0] : result_type();
-        for (size_t __i = 1; __i < __n; ++__i)
-            __r += __expr_[__i];
-        return __r;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type min() const
-    {
-        size_t __n = size();
-        result_type __r = __n ? (*this)[0] : result_type();
-        for (size_t __i = 1; __i < __n; ++__i)
-        {
-            result_type __x = __expr_[__i];
-            if (__x < __r)
-                __r = __x;
-        }
-        return __r;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    result_type max() const
-    {
-        size_t __n = size();
-        result_type __r = __n ? (*this)[0] : result_type();
-        for (size_t __i = 1; __i < __n; ++__i)
-        {
-            result_type __x = __expr_[__i];
-            if (__r < __x)
-                __r = __x;
-        }
-        return __r;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__shift_expr<_ValExpr> > shift (int __i) const
-        {return __val_expr<__shift_expr<_ValExpr> >(__shift_expr<_ValExpr>(__i, __expr_));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<__cshift_expr<_ValExpr> > cshift(int __i) const
-        {return __val_expr<__cshift_expr<_ValExpr> >(__cshift_expr<_ValExpr>(__i, __expr_));}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<_UnaryOp<__apply_expr<value_type, value_type(*)(value_type)>, _ValExpr> >
-    apply(value_type __f(value_type)) const
-    {
-        typedef __apply_expr<value_type, value_type(*)(value_type)> _Op;
-        typedef _UnaryOp<_Op, _ValExpr> _NewExpr;
-        return __val_expr<_NewExpr>(_NewExpr(_Op(__f), __expr_));
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __val_expr<_UnaryOp<__apply_expr<value_type, value_type(*)(const value_type&)>, _ValExpr> >
-    apply(value_type __f(const value_type&)) const
-    {
-        typedef __apply_expr<value_type, value_type(*)(const value_type&)> _Op;
-        typedef _UnaryOp<_Op, _ValExpr> _NewExpr;
-        return __val_expr<_NewExpr>(_NewExpr(_Op(__f), __expr_));
-    }
-};
-
-template<class _ValExpr>
-__val_expr<_ValExpr>::operator valarray<__val_expr::result_type>() const
-{
-    valarray<result_type> __r;
-    size_t __n = __expr_.size();
-    if (__n)
-    {
-        __r.__begin_ =
-            __r.__end_ =
-                static_cast<result_type*>(
-                    _VSTD::__libcpp_allocate(__n * sizeof(result_type), _LIBCPP_ALIGNOF(result_type)));
-        for (size_t __i = 0; __i != __n; ++__r.__end_, ++__i)
-            ::new (__r.__end_) result_type(__expr_[__i]);
-    }
-    return __r;
-}
-
-// valarray
-
-template <class _Tp>
-inline
-valarray<_Tp>::valarray(size_t __n)
-    : __begin_(0),
-      __end_(0)
-{
-    if (__n)
-    {
-        __begin_ = __end_ = static_cast<value_type*>(
-            _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (size_t __n_left = __n; __n_left; --__n_left, ++__end_)
-                ::new (__end_) value_type();
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __clear(__n);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>::valarray(const value_type& __x, size_t __n)
-    : __begin_(0),
-      __end_(0)
-{
-    resize(__n, __x);
-}
-
-template <class _Tp>
-valarray<_Tp>::valarray(const value_type* __p, size_t __n)
-    : __begin_(0),
-      __end_(0)
-{
-    if (__n)
-    {
-        __begin_ = __end_ = static_cast<value_type*>(
-            _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (size_t __n_left = __n; __n_left; ++__end_, ++__p, --__n_left)
-                ::new (__end_) value_type(*__p);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __clear(__n);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template <class _Tp>
-valarray<_Tp>::valarray(const valarray& __v)
-    : __begin_(0),
-      __end_(0)
-{
-    if (__v.size())
-    {
-        __begin_ = __end_ = static_cast<value_type*>(
-            _VSTD::__libcpp_allocate(__v.size() * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (value_type* __p = __v.__begin_; __p != __v.__end_; ++__end_, ++__p)
-                ::new (__end_) value_type(*__p);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __clear(__v.size());
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-inline
-valarray<_Tp>::valarray(valarray&& __v) _NOEXCEPT
-    : __begin_(__v.__begin_),
-      __end_(__v.__end_)
-{
-    __v.__begin_ = __v.__end_ = nullptr;
-}
-
-template <class _Tp>
-valarray<_Tp>::valarray(initializer_list<value_type> __il)
-    : __begin_(0),
-      __end_(0)
-{
-    const size_t __n = __il.size();
-    if (__n)
-    {
-        __begin_ = __end_ = static_cast<value_type*>(
-_VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            size_t __n_left = __n;
-            for (const value_type* __p = __il.begin(); __n_left; ++__end_, ++__p, --__n_left)
-                ::new (__end_) value_type(*__p);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __clear(__n);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-valarray<_Tp>::valarray(const slice_array<value_type>& __sa)
-    : __begin_(0),
-      __end_(0)
-{
-    const size_t __n = __sa.__size_;
-    if (__n)
-    {
-        __begin_ = __end_ = static_cast<value_type*>(
-          _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            size_t __n_left = __n;
-            for (const value_type* __p = __sa.__vp_; __n_left; ++__end_, __p += __sa.__stride_, --__n_left)
-                ::new (__end_) value_type(*__p);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __clear(__n);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template <class _Tp>
-valarray<_Tp>::valarray(const gslice_array<value_type>& __ga)
-    : __begin_(0),
-      __end_(0)
-{
-    const size_t __n = __ga.__1d_.size();
-    if (__n)
-    {
-        __begin_ = __end_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            typedef const size_t* _Ip;
-            const value_type* __s = __ga.__vp_;
-            for (_Ip __i = __ga.__1d_.__begin_, __e = __ga.__1d_.__end_;
-                    __i != __e; ++__i, ++__end_)
-                ::new (__end_) value_type(__s[*__i]);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __clear(__n);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template <class _Tp>
-valarray<_Tp>::valarray(const mask_array<value_type>& __ma)
-    : __begin_(0),
-      __end_(0)
-{
-    const size_t __n = __ma.__1d_.size();
-    if (__n)
-    {
-        __begin_ = __end_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            typedef const size_t* _Ip;
-            const value_type* __s = __ma.__vp_;
-            for (_Ip __i = __ma.__1d_.__begin_, __e = __ma.__1d_.__end_;
-                    __i != __e; ++__i, ++__end_)
-                ::new (__end_) value_type(__s[*__i]);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __clear(__n);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template <class _Tp>
-valarray<_Tp>::valarray(const indirect_array<value_type>& __ia)
-    : __begin_(0),
-      __end_(0)
-{
-    const size_t __n = __ia.__1d_.size();
-    if (__n)
-    {
-        __begin_ = __end_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            typedef const size_t* _Ip;
-            const value_type* __s = __ia.__vp_;
-            for (_Ip __i = __ia.__1d_.__begin_, __e = __ia.__1d_.__end_;
-                    __i != __e; ++__i, ++__end_)
-                ::new (__end_) value_type(__s[*__i]);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __clear(__n);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>::~valarray()
-{
-    __clear(size());
-}
-
-template <class _Tp>
-valarray<_Tp>&
-valarray<_Tp>::__assign_range(const value_type* __f, const value_type* __l)
-{
-    size_t __n = __l - __f;
-    if (size() != __n)
-    {
-        __clear(size());
-        __begin_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-        __end_ = __begin_ + __n;
-        _VSTD::uninitialized_copy(__f, __l, __begin_);
-    } else {
-        _VSTD::copy(__f, __l, __begin_);
-    }
-    return *this;
-}
-
-template <class _Tp>
-valarray<_Tp>&
-valarray<_Tp>::operator=(const valarray& __v)
-{
-    if (this != &__v)
-        return __assign_range(__v.__begin_, __v.__end_);
-    return *this;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator=(valarray&& __v) _NOEXCEPT
-{
-    __clear(size());
-    __begin_ = __v.__begin_;
-    __end_ = __v.__end_;
-    __v.__begin_ = nullptr;
-    __v.__end_ = nullptr;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator=(initializer_list<value_type> __il)
-{
-    return __assign_range(__il.begin(), __il.end());
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator=(const value_type& __x)
-{
-    _VSTD::fill(__begin_, __end_, __x);
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator=(const slice_array<value_type>& __sa)
-{
-    value_type* __t = __begin_;
-    const value_type* __s = __sa.__vp_;
-    for (size_t __n = __sa.__size_; __n; --__n, __s += __sa.__stride_, ++__t)
-        *__t = *__s;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator=(const gslice_array<value_type>& __ga)
-{
-    typedef const size_t* _Ip;
-    value_type* __t = __begin_;
-    const value_type* __s = __ga.__vp_;
-    for (_Ip __i = __ga.__1d_.__begin_, __e = __ga.__1d_.__end_;
-                    __i != __e; ++__i, ++__t)
-        *__t = __s[*__i];
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator=(const mask_array<value_type>& __ma)
-{
-    typedef const size_t* _Ip;
-    value_type* __t = __begin_;
-    const value_type* __s = __ma.__vp_;
-    for (_Ip __i = __ma.__1d_.__begin_, __e = __ma.__1d_.__end_;
-                    __i != __e; ++__i, ++__t)
-        *__t = __s[*__i];
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator=(const indirect_array<value_type>& __ia)
-{
-    typedef const size_t* _Ip;
-    value_type* __t = __begin_;
-    const value_type* __s = __ia.__vp_;
-    for (_Ip __i = __ia.__1d_.__begin_, __e = __ia.__1d_.__end_;
-                    __i != __e; ++__i, ++__t)
-        *__t = __s[*__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _ValExpr>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator=(const __val_expr<_ValExpr>& __v)
-{
-    size_t __n = __v.size();
-    if (size() != __n)
-        resize(__n);
-    value_type* __t = __begin_;
-    for (size_t __i = 0; __i != __n; ++__t, ++__i)
-        *__t = result_type(__v[__i]);
-    return *this;
-}
-
-template <class _Tp>
-inline
-__val_expr<__slice_expr<const valarray<_Tp>&> >
-valarray<_Tp>::operator[](slice __s) const
-{
-    return __val_expr<__slice_expr<const valarray&> >(__slice_expr<const valarray&>(__s, *this));
-}
-
-template <class _Tp>
-inline
-slice_array<_Tp>
-valarray<_Tp>::operator[](slice __s)
-{
-    return slice_array<value_type>(__s, *this);
-}
-
-template <class _Tp>
-inline
-__val_expr<__indirect_expr<const valarray<_Tp>&> >
-valarray<_Tp>::operator[](const gslice& __gs) const
-{
-    return __val_expr<__indirect_expr<const valarray&> >(__indirect_expr<const valarray&>(__gs.__1d_, *this));
-}
-
-template <class _Tp>
-inline
-gslice_array<_Tp>
-valarray<_Tp>::operator[](const gslice& __gs)
-{
-    return gslice_array<value_type>(__gs, *this);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-inline
-__val_expr<__indirect_expr<const valarray<_Tp>&> >
-valarray<_Tp>::operator[](gslice&& __gs) const
-{
-    return __val_expr<__indirect_expr<const valarray&> >(__indirect_expr<const valarray&>(move(__gs.__1d_), *this));
-}
-
-template <class _Tp>
-inline
-gslice_array<_Tp>
-valarray<_Tp>::operator[](gslice&& __gs)
-{
-    return gslice_array<value_type>(move(__gs), *this);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-inline
-__val_expr<__mask_expr<const valarray<_Tp>&> >
-valarray<_Tp>::operator[](const valarray<bool>& __vb) const
-{
-    return __val_expr<__mask_expr<const valarray&> >(__mask_expr<const valarray&>(__vb, *this));
-}
-
-template <class _Tp>
-inline
-mask_array<_Tp>
-valarray<_Tp>::operator[](const valarray<bool>& __vb)
-{
-    return mask_array<value_type>(__vb, *this);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-inline
-__val_expr<__mask_expr<const valarray<_Tp>&> >
-valarray<_Tp>::operator[](valarray<bool>&& __vb) const
-{
-    return __val_expr<__mask_expr<const valarray&> >(__mask_expr<const valarray&>(move(__vb), *this));
-}
-
-template <class _Tp>
-inline
-mask_array<_Tp>
-valarray<_Tp>::operator[](valarray<bool>&& __vb)
-{
-    return mask_array<value_type>(move(__vb), *this);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-inline
-__val_expr<__indirect_expr<const valarray<_Tp>&> >
-valarray<_Tp>::operator[](const valarray<size_t>& __vs) const
-{
-    return __val_expr<__indirect_expr<const valarray&> >(__indirect_expr<const valarray&>(__vs, *this));
-}
-
-template <class _Tp>
-inline
-indirect_array<_Tp>
-valarray<_Tp>::operator[](const valarray<size_t>& __vs)
-{
-    return indirect_array<value_type>(__vs, *this);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-inline
-__val_expr<__indirect_expr<const valarray<_Tp>&> >
-valarray<_Tp>::operator[](valarray<size_t>&& __vs) const
-{
-    return __val_expr<__indirect_expr<const valarray&> >(__indirect_expr<const valarray&>(move(__vs), *this));
-}
-
-template <class _Tp>
-inline
-indirect_array<_Tp>
-valarray<_Tp>::operator[](valarray<size_t>&& __vs)
-{
-    return indirect_array<value_type>(move(__vs), *this);
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Tp>
-valarray<_Tp>
-valarray<_Tp>::operator+() const
-{
-    valarray<value_type> __r;
-    size_t __n = size();
-    if (__n)
-    {
-        __r.__begin_ =
-            __r.__end_ =
-                static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-        for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
-            ::new (__r.__end_) value_type(+*__p);
-    }
-    return __r;
-}
-
-template <class _Tp>
-valarray<_Tp>
-valarray<_Tp>::operator-() const
-{
-    valarray<value_type> __r;
-    size_t __n = size();
-    if (__n)
-    {
-        __r.__begin_ =
-            __r.__end_ =
-                static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-        for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
-            ::new (__r.__end_) value_type(-*__p);
-    }
-    return __r;
-}
-
-template <class _Tp>
-valarray<_Tp>
-valarray<_Tp>::operator~() const
-{
-    valarray<value_type> __r;
-    size_t __n = size();
-    if (__n)
-    {
-        __r.__begin_ =
-            __r.__end_ =
-                static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-        for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
-            ::new (__r.__end_) value_type(~*__p);
-    }
-    return __r;
-}
-
-template <class _Tp>
-valarray<bool>
-valarray<_Tp>::operator!() const
-{
-    valarray<bool> __r;
-    size_t __n = size();
-    if (__n)
-    {
-        __r.__begin_ =
-            __r.__end_ =
-                static_cast<bool*>(_VSTD::__libcpp_allocate(__n * sizeof(bool), _LIBCPP_ALIGNOF(bool)));
-        for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
-            ::new (__r.__end_) bool(!*__p);
-    }
-    return __r;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator*=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p *= __x;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator/=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p /= __x;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator%=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p %= __x;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator+=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p += __x;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator-=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p -= __x;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator^=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p ^= __x;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator&=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p &= __x;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator|=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p |= __x;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator<<=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p <<= __x;
-    return *this;
-}
-
-template <class _Tp>
-inline
-valarray<_Tp>&
-valarray<_Tp>::operator>>=(const value_type& __x)
-{
-    for (value_type* __p = __begin_; __p != __end_; ++__p)
-        *__p >>= __x;
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator*=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t *= __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator/=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t /= __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator%=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t %= __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator+=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t += __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator-=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t -= __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator^=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t ^= __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator|=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t |= __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator&=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t &= __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator<<=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t <<= __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-template <class _Expr>
-inline
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    valarray<_Tp>&
->::type
-valarray<_Tp>::operator>>=(const _Expr& __v)
-{
-    size_t __i = 0;
-    for (value_type* __t = __begin_; __t != __end_ ; ++__t, ++__i)
-        *__t >>= __v[__i];
-    return *this;
-}
-
-template <class _Tp>
-inline
-void
-valarray<_Tp>::swap(valarray& __v) _NOEXCEPT
-{
-    _VSTD::swap(__begin_, __v.__begin_);
-    _VSTD::swap(__end_, __v.__end_);
-}
-
-template <class _Tp>
-inline
-_Tp
-valarray<_Tp>::sum() const
-{
-    if (__begin_ == __end_)
-        return value_type();
-    const value_type* __p = __begin_;
-    _Tp __r = *__p;
-    for (++__p; __p != __end_; ++__p)
-        __r += *__p;
-    return __r;
-}
-
-template <class _Tp>
-inline
-_Tp
-valarray<_Tp>::min() const
-{
-    if (__begin_ == __end_)
-        return value_type();
-    return *_VSTD::min_element(__begin_, __end_);
-}
-
-template <class _Tp>
-inline
-_Tp
-valarray<_Tp>::max() const
-{
-    if (__begin_ == __end_)
-        return value_type();
-    return *_VSTD::max_element(__begin_, __end_);
-}
-
-template <class _Tp>
-valarray<_Tp>
-valarray<_Tp>::shift(int __i) const
-{
-    valarray<value_type> __r;
-    size_t __n = size();
-    if (__n)
-    {
-        __r.__begin_ =
-            __r.__end_ =
-                static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-        const value_type* __sb;
-        value_type* __tb;
-        value_type* __te;
-        if (__i >= 0)
-        {
-            __i = _VSTD::min(__i, static_cast<int>(__n));
-            __sb = __begin_ + __i;
-            __tb = __r.__begin_;
-            __te = __r.__begin_ + (__n - __i);
-        }
-        else
-        {
-            __i = _VSTD::min(-__i, static_cast<int>(__n));
-            __sb = __begin_;
-            __tb = __r.__begin_ + __i;
-            __te = __r.__begin_ + __n;
-        }
-        for (; __r.__end_ != __tb; ++__r.__end_)
-            ::new (__r.__end_) value_type();
-        for (; __r.__end_ != __te; ++__r.__end_, ++__sb)
-            ::new (__r.__end_) value_type(*__sb);
-        for (__te = __r.__begin_ + __n; __r.__end_ != __te; ++__r.__end_)
-            ::new (__r.__end_) value_type();
-    }
-    return __r;
-}
-
-template <class _Tp>
-valarray<_Tp>
-valarray<_Tp>::cshift(int __i) const
-{
-    valarray<value_type> __r;
-    size_t __n = size();
-    if (__n)
-    {
-        __r.__begin_ =
-            __r.__end_ =
-                static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-        __i %= static_cast<int>(__n);
-        const value_type* __m = __i >= 0 ? __begin_ + __i : __end_ + __i;
-        for (const value_type* __s = __m; __s != __end_; ++__r.__end_, ++__s)
-            ::new (__r.__end_) value_type(*__s);
-        for (const value_type* __s = __begin_; __s != __m; ++__r.__end_, ++__s)
-            ::new (__r.__end_) value_type(*__s);
-    }
-    return __r;
-}
-
-template <class _Tp>
-valarray<_Tp>
-valarray<_Tp>::apply(value_type __f(value_type)) const
-{
-    valarray<value_type> __r;
-    size_t __n = size();
-    if (__n)
-    {
-        __r.__begin_ =
-            __r.__end_ =
-                static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-        for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
-            ::new (__r.__end_) value_type(__f(*__p));
-    }
-    return __r;
-}
-
-template <class _Tp>
-valarray<_Tp>
-valarray<_Tp>::apply(value_type __f(const value_type&)) const
-{
-    valarray<value_type> __r;
-    size_t __n = size();
-    if (__n)
-    {
-        __r.__begin_ =
-            __r.__end_ =
-                static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-        for (const value_type* __p = __begin_; __n; ++__r.__end_, ++__p, --__n)
-            ::new (__r.__end_) value_type(__f(*__p));
-    }
-    return __r;
-}
-
-template <class _Tp>
-inline
-void valarray<_Tp>::__clear(size_t __capacity)
-{
-  if (__begin_ != nullptr)
-  {
-    while (__end_ != __begin_)
-      (--__end_)->~value_type();
-    _VSTD::__libcpp_deallocate(__begin_, __capacity * sizeof(value_type), _LIBCPP_ALIGNOF(value_type));
-    __begin_ = __end_ = nullptr;
-  }
-}
-
-template <class _Tp>
-void
-valarray<_Tp>::resize(size_t __n, value_type __x)
-{
-    __clear(size());
-    if (__n)
-    {
-        __begin_ = __end_ = static_cast<value_type*>(
-           _VSTD::__libcpp_allocate(__n * sizeof(value_type), _LIBCPP_ALIGNOF(value_type)));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            for (size_t __n_left = __n; __n_left; --__n_left, ++__end_)
-                ::new (__end_) value_type(__x);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            __clear(__n);
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template<class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(valarray<_Tp>& __x, valarray<_Tp>& __y) _NOEXCEPT
-{
-    __x.swap(__y);
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<multiplies<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator*(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<multiplies<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(multiplies<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<multiplies<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator*(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<multiplies<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(multiplies<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<multiplies<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator*(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<multiplies<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(multiplies<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<divides<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator/(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<divides<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(divides<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<divides<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator/(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<divides<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(divides<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<divides<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator/(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<divides<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(divides<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<modulus<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator%(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<modulus<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(modulus<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<modulus<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator%(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<modulus<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(modulus<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<modulus<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator%(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<modulus<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(modulus<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<plus<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator+(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<plus<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(plus<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<plus<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator+(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<plus<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(plus<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<plus<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator+(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<plus<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(plus<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<minus<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator-(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<minus<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(minus<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<minus<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator-(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<minus<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(minus<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<minus<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator-(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<minus<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(minus<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<bit_xor<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator^(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<bit_xor<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(bit_xor<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<bit_xor<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator^(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<bit_xor<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(bit_xor<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<bit_xor<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator^(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<bit_xor<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(bit_xor<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<bit_and<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator&(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<bit_and<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(bit_and<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<bit_and<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator&(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<bit_and<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(bit_and<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<bit_and<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator&(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<bit_and<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(bit_and<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<bit_or<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator|(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<bit_or<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(bit_or<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<bit_or<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator|(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<bit_or<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(bit_or<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<bit_or<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator|(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<bit_or<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(bit_or<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<__bit_shift_left<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator<<(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<__bit_shift_left<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(__bit_shift_left<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<__bit_shift_left<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator<<(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<__bit_shift_left<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(__bit_shift_left<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<__bit_shift_left<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator<<(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<__bit_shift_left<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__bit_shift_left<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<__bit_shift_right<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator>>(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<__bit_shift_right<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(__bit_shift_right<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<__bit_shift_right<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator>>(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<__bit_shift_right<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(__bit_shift_right<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<__bit_shift_right<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator>>(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<__bit_shift_right<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__bit_shift_right<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<logical_and<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator&&(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<logical_and<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(logical_and<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<logical_and<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator&&(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<logical_and<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(logical_and<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<logical_and<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator&&(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<logical_and<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(logical_and<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<logical_or<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator||(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<logical_or<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(logical_or<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<logical_or<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator||(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<logical_or<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(logical_or<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<logical_or<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator||(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<logical_or<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(logical_or<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<equal_to<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator==(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<equal_to<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(equal_to<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<equal_to<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator==(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<equal_to<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(equal_to<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<equal_to<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator==(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<equal_to<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(equal_to<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<not_equal_to<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator!=(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<not_equal_to<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(not_equal_to<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<not_equal_to<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator!=(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<not_equal_to<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(not_equal_to<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<not_equal_to<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator!=(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<not_equal_to<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(not_equal_to<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<less<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator<(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<less<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(less<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<less<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator<(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<less<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(less<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<less<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator<(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<less<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(less<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<greater<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator>(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<greater<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(greater<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<greater<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator>(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<greater<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(greater<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<greater<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator>(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<greater<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(greater<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<less_equal<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator<=(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<less_equal<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(less_equal<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<less_equal<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator<=(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<less_equal<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(less_equal<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<less_equal<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator<=(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<less_equal<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(less_equal<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<greater_equal<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-operator>=(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<greater_equal<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(greater_equal<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<greater_equal<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-operator>=(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<greater_equal<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(greater_equal<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<greater_equal<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-operator>=(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<greater_equal<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(greater_equal<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__abs_expr<typename _Expr::value_type>, _Expr> >
->::type
-abs(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__abs_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__abs_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__acos_expr<typename _Expr::value_type>, _Expr> >
->::type
-acos(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__acos_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__acos_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__asin_expr<typename _Expr::value_type>, _Expr> >
->::type
-asin(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__asin_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__asin_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__atan_expr<typename _Expr::value_type>, _Expr> >
->::type
-atan(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__atan_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__atan_expr<value_type>(), __x));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<__atan2_expr<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-atan2(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<__atan2_expr<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(__atan2_expr<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<__atan2_expr<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-atan2(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<__atan2_expr<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(__atan2_expr<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<__atan2_expr<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-atan2(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<__atan2_expr<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__atan2_expr<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__cos_expr<typename _Expr::value_type>, _Expr> >
->::type
-cos(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__cos_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__cos_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__cosh_expr<typename _Expr::value_type>, _Expr> >
->::type
-cosh(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__cosh_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__cosh_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__exp_expr<typename _Expr::value_type>, _Expr> >
->::type
-exp(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__exp_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__exp_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__log_expr<typename _Expr::value_type>, _Expr> >
->::type
-log(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__log_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__log_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__log10_expr<typename _Expr::value_type>, _Expr> >
->::type
-log10(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__log10_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__log10_expr<value_type>(), __x));
-}
-
-template<class _Expr1, class _Expr2>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr1>::value && __is_val_expr<_Expr2>::value,
-    __val_expr<_BinaryOp<__pow_expr<typename _Expr1::value_type>, _Expr1, _Expr2> >
->::type
-pow(const _Expr1& __x, const _Expr2& __y)
-{
-    typedef typename _Expr1::value_type value_type;
-    typedef _BinaryOp<__pow_expr<value_type>, _Expr1, _Expr2> _Op;
-    return __val_expr<_Op>(_Op(__pow_expr<value_type>(), __x, __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<__pow_expr<typename _Expr::value_type>,
-               _Expr, __scalar_expr<typename _Expr::value_type> > >
->::type
-pow(const _Expr& __x, const typename _Expr::value_type& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<__pow_expr<value_type>, _Expr, __scalar_expr<value_type> > _Op;
-    return __val_expr<_Op>(_Op(__pow_expr<value_type>(),
-                           __x, __scalar_expr<value_type>(__y, __x.size())));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_BinaryOp<__pow_expr<typename _Expr::value_type>,
-               __scalar_expr<typename _Expr::value_type>, _Expr> >
->::type
-pow(const typename _Expr::value_type& __x, const _Expr& __y)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _BinaryOp<__pow_expr<value_type>, __scalar_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__pow_expr<value_type>(),
-                           __scalar_expr<value_type>(__x, __y.size()), __y));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__sin_expr<typename _Expr::value_type>, _Expr> >
->::type
-sin(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__sin_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__sin_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__sinh_expr<typename _Expr::value_type>, _Expr> >
->::type
-sinh(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__sinh_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__sinh_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__sqrt_expr<typename _Expr::value_type>, _Expr> >
->::type
-sqrt(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__sqrt_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__sqrt_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__tan_expr<typename _Expr::value_type>, _Expr> >
->::type
-tan(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__tan_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__tan_expr<value_type>(), __x));
-}
-
-template<class _Expr>
-inline _LIBCPP_INLINE_VISIBILITY
-typename enable_if
-<
-    __is_val_expr<_Expr>::value,
-    __val_expr<_UnaryOp<__tanh_expr<typename _Expr::value_type>, _Expr> >
->::type
-tanh(const _Expr& __x)
-{
-    typedef typename _Expr::value_type value_type;
-    typedef _UnaryOp<__tanh_expr<value_type>, _Expr> _Op;
-    return __val_expr<_Op>(_Op(__tanh_expr<value_type>(), __x));
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-begin(valarray<_Tp>& __v)
-{
-    return __v.__begin_;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-const _Tp*
-begin(const valarray<_Tp>& __v)
-{
-    return __v.__begin_;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-_Tp*
-end(valarray<_Tp>& __v)
-{
-    return __v.__end_;
-}
-
-template <class _Tp>
-inline _LIBCPP_INLINE_VISIBILITY
-const _Tp*
-end(const valarray<_Tp>& __v)
-{
-    return __v.__end_;
-}
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_VALARRAY
diff --git a/lib/libcxx/include/variant b/lib/libcxx/include/variant
deleted file mode 100644
index a4339de6cde..00000000000
--- a/lib/libcxx/include/variant
+++ /dev/null
@@ -1,1616 +0,0 @@
-// -*- C++ -*-
-//===------------------------------ variant -------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_VARIANT
-#define _LIBCPP_VARIANT
-
-/*
-   variant synopsis
-
-namespace std {
-
-  // 20.7.2, class template variant
-  template <class... Types>
-  class variant {
-  public:
-
-    // 20.7.2.1, constructors
-    constexpr variant() noexcept(see below);
-    variant(const variant&);                // constexpr in C++20
-    variant(variant&&) noexcept(see below); // constexpr in C++20
-
-    template <class T> constexpr variant(T&&) noexcept(see below);
-
-    template <class T, class... Args>
-    constexpr explicit variant(in_place_type_t<T>, Args&&...);
-
-    template <class T, class U, class... Args>
-    constexpr explicit variant(
-        in_place_type_t<T>, initializer_list<U>, Args&&...);
-
-    template <size_t I, class... Args>
-    constexpr explicit variant(in_place_index_t<I>, Args&&...);
-
-    template <size_t I, class U, class... Args>
-    constexpr explicit variant(
-        in_place_index_t<I>, initializer_list<U>, Args&&...);
-
-    // 20.7.2.2, destructor
-    ~variant();
-
-    // 20.7.2.3, assignment
-    variant& operator=(const variant&);                // constexpr in C++20
-    variant& operator=(variant&&) noexcept(see below); // constexpr in C++20
-
-    template <class T> variant& operator=(T&&) noexcept(see below);
-
-    // 20.7.2.4, modifiers
-    template <class T, class... Args>
-    T& emplace(Args&&...);
-
-    template <class T, class U, class... Args>
-    T& emplace(initializer_list<U>, Args&&...);
-
-    template <size_t I, class... Args>
-    variant_alternative_t<I, variant>& emplace(Args&&...);
-
-    template <size_t I, class U, class...  Args>
-    variant_alternative_t<I, variant>& emplace(initializer_list<U>, Args&&...);
-
-    // 20.7.2.5, value status
-    constexpr bool valueless_by_exception() const noexcept;
-    constexpr size_t index() const noexcept;
-
-    // 20.7.2.6, swap
-    void swap(variant&) noexcept(see below);
-  };
-
-  // 20.7.3, variant helper classes
-  template <class T> struct variant_size; // undefined
-
-  template <class T>
-  inline constexpr size_t variant_size_v = variant_size<T>::value;
-
-  template <class T> struct variant_size<const T>;
-  template <class T> struct variant_size<volatile T>;
-  template <class T> struct variant_size<const volatile T>;
-
-  template <class... Types>
-  struct variant_size<variant<Types...>>;
-
-  template <size_t I, class T> struct variant_alternative; // undefined
-
-  template <size_t I, class T>
-  using variant_alternative_t = typename variant_alternative<I, T>::type;
-
-  template <size_t I, class T> struct variant_alternative<I, const T>;
-  template <size_t I, class T> struct variant_alternative<I, volatile T>;
-  template <size_t I, class T> struct variant_alternative<I, const volatile T>;
-
-  template <size_t I, class... Types>
-  struct variant_alternative<I, variant<Types...>>;
-
-  inline constexpr size_t variant_npos = -1;
-
-  // 20.7.4, value access
-  template <class T, class... Types>
-  constexpr bool holds_alternative(const variant<Types...>&) noexcept;
-
-  template <size_t I, class... Types>
-  constexpr variant_alternative_t<I, variant<Types...>>&
-  get(variant<Types...>&);
-
-  template <size_t I, class... Types>
-  constexpr variant_alternative_t<I, variant<Types...>>&&
-  get(variant<Types...>&&);
-
-  template <size_t I, class... Types>
-  constexpr variant_alternative_t<I, variant<Types...>> const&
-  get(const variant<Types...>&);
-
-  template <size_t I, class... Types>
-  constexpr variant_alternative_t<I, variant<Types...>> const&&
-  get(const variant<Types...>&&);
-
-  template <class T, class...  Types>
-  constexpr T& get(variant<Types...>&);
-
-  template <class T, class... Types>
-  constexpr T&& get(variant<Types...>&&);
-
-  template <class T, class... Types>
-  constexpr const T& get(const variant<Types...>&);
-
-  template <class T, class... Types>
-  constexpr const T&& get(const variant<Types...>&&);
-
-  template <size_t I, class... Types>
-  constexpr add_pointer_t<variant_alternative_t<I, variant<Types...>>>
-  get_if(variant<Types...>*) noexcept;
-
-  template <size_t I, class... Types>
-  constexpr add_pointer_t<const variant_alternative_t<I, variant<Types...>>>
-  get_if(const variant<Types...>*) noexcept;
-
-  template <class T, class... Types>
-  constexpr add_pointer_t<T>
-  get_if(variant<Types...>*) noexcept;
-
-  template <class T, class... Types>
-  constexpr add_pointer_t<const T>
-  get_if(const variant<Types...>*) noexcept;
-
-  // 20.7.5, relational operators
-  template <class... Types>
-  constexpr bool operator==(const variant<Types...>&, const variant<Types...>&);
-
-  template <class... Types>
-  constexpr bool operator!=(const variant<Types...>&, const variant<Types...>&);
-
-  template <class... Types>
-  constexpr bool operator<(const variant<Types...>&, const variant<Types...>&);
-
-  template <class... Types>
-  constexpr bool operator>(const variant<Types...>&, const variant<Types...>&);
-
-  template <class... Types>
-  constexpr bool operator<=(const variant<Types...>&, const variant<Types...>&);
-
-  template <class... Types>
-  constexpr bool operator>=(const variant<Types...>&, const variant<Types...>&);
-
-  // 20.7.6, visitation
-  template <class Visitor, class... Variants>
-  constexpr see below visit(Visitor&&, Variants&&...);
-
-  // 20.7.7, class monostate
-  struct monostate;
-
-  // 20.7.8, monostate relational operators
-  constexpr bool operator<(monostate, monostate) noexcept;
-  constexpr bool operator>(monostate, monostate) noexcept;
-  constexpr bool operator<=(monostate, monostate) noexcept;
-  constexpr bool operator>=(monostate, monostate) noexcept;
-  constexpr bool operator==(monostate, monostate) noexcept;
-  constexpr bool operator!=(monostate, monostate) noexcept;
-
-  // 20.7.9, specialized algorithms
-  template <class... Types>
-  void swap(variant<Types...>&, variant<Types...>&) noexcept(see below);
-
-  // 20.7.10, class bad_variant_access
-  class bad_variant_access;
-
-  // 20.7.11, hash support
-  template <class T> struct hash;
-  template <class... Types> struct hash<variant<Types...>>;
-  template <> struct hash<monostate>;
-
-} // namespace std
-
-*/
-
-#include <__config>
-#include <__tuple>
-#include <array>
-#include <exception>
-#include <functional>
-#include <initializer_list>
-#include <new>
-#include <tuple>
-#include <type_traits>
-#include <utility>
-#include <limits>
-#include <version>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-namespace std { // explicitly not using versioning namespace
-
-class _LIBCPP_EXCEPTION_ABI _LIBCPP_AVAILABILITY_BAD_VARIANT_ACCESS bad_variant_access : public exception {
-public:
-  virtual const char* what() const _NOEXCEPT;
-};
-
-} // namespace std
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-#if _LIBCPP_STD_VER > 14
-
-_LIBCPP_NORETURN
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-void __throw_bad_variant_access() {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        throw bad_variant_access();
-#else
-        _VSTD::abort();
-#endif
-}
-
-template <class... _Types>
-class _LIBCPP_TEMPLATE_VIS variant;
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS variant_size;
-
-template <class _Tp>
-_LIBCPP_INLINE_VAR constexpr size_t variant_size_v = variant_size<_Tp>::value;
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS variant_size<const _Tp> : variant_size<_Tp> {};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS variant_size<volatile _Tp> : variant_size<_Tp> {};
-
-template <class _Tp>
-struct _LIBCPP_TEMPLATE_VIS variant_size<const volatile _Tp>
-    : variant_size<_Tp> {};
-
-template <class... _Types>
-struct _LIBCPP_TEMPLATE_VIS variant_size<variant<_Types...>>
-    : integral_constant<size_t, sizeof...(_Types)> {};
-
-template <size_t _Ip, class _Tp>
-struct _LIBCPP_TEMPLATE_VIS variant_alternative;
-
-template <size_t _Ip, class _Tp>
-using variant_alternative_t = typename variant_alternative<_Ip, _Tp>::type;
-
-template <size_t _Ip, class _Tp>
-struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, const _Tp>
-    : add_const<variant_alternative_t<_Ip, _Tp>> {};
-
-template <size_t _Ip, class _Tp>
-struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, volatile _Tp>
-    : add_volatile<variant_alternative_t<_Ip, _Tp>> {};
-
-template <size_t _Ip, class _Tp>
-struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, const volatile _Tp>
-    : add_cv<variant_alternative_t<_Ip, _Tp>> {};
-
-template <size_t _Ip, class... _Types>
-struct _LIBCPP_TEMPLATE_VIS variant_alternative<_Ip, variant<_Types...>> {
-  static_assert(_Ip < sizeof...(_Types), "Index out of bounds in std::variant_alternative<>");
-  using type = __type_pack_element<_Ip, _Types...>;
-};
-
-_LIBCPP_INLINE_VAR constexpr size_t variant_npos = static_cast<size_t>(-1);
-
-constexpr int __choose_index_type(unsigned int __num_elem) {
-  if (__num_elem < std::numeric_limits<unsigned char>::max())
-    return 0;
-  if (__num_elem < std::numeric_limits<unsigned short>::max())
-    return 1;
-  return 2;
-}
-
-template <size_t _NumAlts>
-using __variant_index_t =
-#ifndef _LIBCPP_ABI_VARIANT_INDEX_TYPE_OPTIMIZATION
-  unsigned int;
-#else
-  std::tuple_element_t<
-      __choose_index_type(_NumAlts),
-      std::tuple<unsigned char, unsigned short, unsigned int>
-  >;
-#endif
-
-template <class _IndexType>
-constexpr _IndexType __variant_npos = static_cast<_IndexType>(-1);
-
-namespace __find_detail {
-
-template <class _Tp, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr size_t __find_index() {
-  constexpr bool __matches[] = {is_same_v<_Tp, _Types>...};
-  size_t __result = __not_found;
-  for (size_t __i = 0; __i < sizeof...(_Types); ++__i) {
-    if (__matches[__i]) {
-      if (__result != __not_found) {
-        return __ambiguous;
-      }
-      __result = __i;
-    }
-  }
-  return __result;
-}
-
-template <size_t _Index>
-struct __find_unambiguous_index_sfinae_impl
-    : integral_constant<size_t, _Index> {};
-
-template <>
-struct __find_unambiguous_index_sfinae_impl<__not_found> {};
-
-template <>
-struct __find_unambiguous_index_sfinae_impl<__ambiguous> {};
-
-template <class _Tp, class... _Types>
-struct __find_unambiguous_index_sfinae
-    : __find_unambiguous_index_sfinae_impl<__find_index<_Tp, _Types...>()> {};
-
-} // namespace __find_detail
-
-namespace __variant_detail {
-
-struct __valueless_t {};
-
-enum class _Trait { _TriviallyAvailable, _Available, _Unavailable };
-
-template <typename _Tp,
-          template <typename> class _IsTriviallyAvailable,
-          template <typename> class _IsAvailable>
-constexpr _Trait __trait =
-    _IsTriviallyAvailable<_Tp>::value
-        ? _Trait::_TriviallyAvailable
-        : _IsAvailable<_Tp>::value ? _Trait::_Available : _Trait::_Unavailable;
-
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr _Trait __common_trait(initializer_list<_Trait> __traits) {
-  _Trait __result = _Trait::_TriviallyAvailable;
-  for (_Trait __t : __traits) {
-    if (static_cast<int>(__t) > static_cast<int>(__result)) {
-      __result = __t;
-    }
-  }
-  return __result;
-}
-
-template <typename... _Types>
-struct __traits {
-  static constexpr _Trait __copy_constructible_trait =
-      __common_trait({__trait<_Types,
-                              is_trivially_copy_constructible,
-                              is_copy_constructible>...});
-
-  static constexpr _Trait __move_constructible_trait =
-      __common_trait({__trait<_Types,
-                              is_trivially_move_constructible,
-                              is_move_constructible>...});
-
-  static constexpr _Trait __copy_assignable_trait = __common_trait(
-      {__copy_constructible_trait,
-       __trait<_Types, is_trivially_copy_assignable, is_copy_assignable>...});
-
-  static constexpr _Trait __move_assignable_trait = __common_trait(
-      {__move_constructible_trait,
-       __trait<_Types, is_trivially_move_assignable, is_move_assignable>...});
-
-  static constexpr _Trait __destructible_trait = __common_trait(
-      {__trait<_Types, is_trivially_destructible, is_destructible>...});
-};
-
-namespace __access {
-
-struct __union {
-  template <class _Vp>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto&& __get_alt(_Vp&& __v, in_place_index_t<0>) {
-    return _VSTD::forward<_Vp>(__v).__head;
-  }
-
-  template <class _Vp, size_t _Ip>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto&& __get_alt(_Vp&& __v, in_place_index_t<_Ip>) {
-    return __get_alt(_VSTD::forward<_Vp>(__v).__tail, in_place_index<_Ip - 1>);
-  }
-};
-
-struct __base {
-  template <size_t _Ip, class _Vp>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto&& __get_alt(_Vp&& __v) {
-    return __union::__get_alt(_VSTD::forward<_Vp>(__v).__data,
-                              in_place_index<_Ip>);
-  }
-};
-
-struct __variant {
-  template <size_t _Ip, class _Vp>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto&& __get_alt(_Vp&& __v) {
-    return __base::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v).__impl);
-  }
-};
-
-} // namespace __access
-
-namespace __visitation {
-
-struct __base {
-  template <class _Visitor, class... _Vs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr decltype(auto)
-  __visit_alt_at(size_t __index, _Visitor&& __visitor, _Vs&&... __vs) {
-    constexpr auto __fdiagonal =
-        __make_fdiagonal<_Visitor&&,
-                         decltype(_VSTD::forward<_Vs>(__vs).__as_base())...>();
-    return __fdiagonal[__index](_VSTD::forward<_Visitor>(__visitor),
-                                _VSTD::forward<_Vs>(__vs).__as_base()...);
-  }
-
-  template <class _Visitor, class... _Vs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr decltype(auto) __visit_alt(_Visitor&& __visitor,
-                                              _Vs&&... __vs) {
-    constexpr auto __fmatrix =
-        __make_fmatrix<_Visitor&&,
-                       decltype(_VSTD::forward<_Vs>(__vs).__as_base())...>();
-    return __at(__fmatrix, __vs.index()...)(
-        _VSTD::forward<_Visitor>(__visitor),
-        _VSTD::forward<_Vs>(__vs).__as_base()...);
-  }
-
-private:
-  template <class _Tp>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr const _Tp& __at(const _Tp& __elem) { return __elem; }
-
-  template <class _Tp, size_t _Np, typename... _Indices>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto&& __at(const array<_Tp, _Np>& __elems,
-                               size_t __index, _Indices... __indices) {
-    return __at(__elems[__index], __indices...);
-  }
-
-  template <class _Fp, class... _Fs>
-  static constexpr void __std_visit_visitor_return_type_check() {
-    static_assert(
-        __all<is_same_v<_Fp, _Fs>...>::value,
-        "`std::visit` requires the visitor to have a single return type.");
-  }
-
-  template <class... _Fs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto __make_farray(_Fs&&... __fs) {
-    __std_visit_visitor_return_type_check<__uncvref_t<_Fs>...>();
-    using __result = array<common_type_t<__uncvref_t<_Fs>...>, sizeof...(_Fs)>;
-    return __result{{_VSTD::forward<_Fs>(__fs)...}};
-  }
-
-  template <std::size_t... _Is>
-  struct __dispatcher {
-    template <class _Fp, class... _Vs>
-    inline _LIBCPP_INLINE_VISIBILITY
-    static constexpr decltype(auto) __dispatch(_Fp __f, _Vs... __vs) {
-        return __invoke_constexpr(
-            static_cast<_Fp>(__f),
-            __access::__base::__get_alt<_Is>(static_cast<_Vs>(__vs))...);
-    }
-  };
-
-  template <class _Fp, class... _Vs, size_t... _Is>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto __make_dispatch(index_sequence<_Is...>) {
-    return __dispatcher<_Is...>::template __dispatch<_Fp, _Vs...>;
-  }
-
-  template <size_t _Ip, class _Fp, class... _Vs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto __make_fdiagonal_impl() {
-    return __make_dispatch<_Fp, _Vs...>(
-        index_sequence<(__identity<_Vs>{}, _Ip)...>{});
-  }
-
-  template <class _Fp, class... _Vs, size_t... _Is>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto __make_fdiagonal_impl(index_sequence<_Is...>) {
-    return __base::__make_farray(__make_fdiagonal_impl<_Is, _Fp, _Vs...>()...);
-  }
-
-  template <class _Fp, class _Vp, class... _Vs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto __make_fdiagonal() {
-    constexpr size_t _Np = __uncvref_t<_Vp>::__size();
-    static_assert(__all<(_Np == __uncvref_t<_Vs>::__size())...>::value);
-    return __make_fdiagonal_impl<_Fp, _Vp, _Vs...>(make_index_sequence<_Np>{});
-  }
-
-  template <class _Fp, class... _Vs, size_t... _Is>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto __make_fmatrix_impl(index_sequence<_Is...> __is) {
-    return __make_dispatch<_Fp, _Vs...>(__is);
-  }
-
-  template <class _Fp, class... _Vs, size_t... _Is, size_t... _Js, class... _Ls>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto __make_fmatrix_impl(index_sequence<_Is...>,
-                                            index_sequence<_Js...>,
-                                            _Ls... __ls) {
-    return __base::__make_farray(__make_fmatrix_impl<_Fp, _Vs...>(
-        index_sequence<_Is..., _Js>{}, __ls...)...);
-  }
-
-  template <class _Fp, class... _Vs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto __make_fmatrix() {
-    return __make_fmatrix_impl<_Fp, _Vs...>(
-        index_sequence<>{}, make_index_sequence<__uncvref_t<_Vs>::__size()>{}...);
-  }
-};
-
-struct __variant {
-  template <class _Visitor, class... _Vs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr decltype(auto)
-  __visit_alt_at(size_t __index, _Visitor&& __visitor, _Vs&&... __vs) {
-    return __base::__visit_alt_at(__index,
-                                  _VSTD::forward<_Visitor>(__visitor),
-                                  _VSTD::forward<_Vs>(__vs).__impl...);
-  }
-
-  template <class _Visitor, class... _Vs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr decltype(auto) __visit_alt(_Visitor&& __visitor,
-                                              _Vs&&... __vs) {
-    return __base::__visit_alt(_VSTD::forward<_Visitor>(__visitor),
-                               _VSTD::forward<_Vs>(__vs).__impl...);
-  }
-
-  template <class _Visitor, class... _Vs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr decltype(auto)
-  __visit_value_at(size_t __index, _Visitor&& __visitor, _Vs&&... __vs) {
-    return __visit_alt_at(
-        __index,
-        __make_value_visitor(_VSTD::forward<_Visitor>(__visitor)),
-        _VSTD::forward<_Vs>(__vs)...);
-  }
-
-  template <class _Visitor, class... _Vs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr decltype(auto) __visit_value(_Visitor&& __visitor,
-                                                _Vs&&... __vs) {
-    return __visit_alt(
-        __make_value_visitor(_VSTD::forward<_Visitor>(__visitor)),
-        _VSTD::forward<_Vs>(__vs)...);
-  }
-
-private:
-  template <class _Visitor, class... _Values>
-  static constexpr void __std_visit_exhaustive_visitor_check() {
-    static_assert(is_invocable_v<_Visitor, _Values...>,
-                  "`std::visit` requires the visitor to be exhaustive.");
-  }
-
-  template <class _Visitor>
-  struct __value_visitor {
-    template <class... _Alts>
-    inline _LIBCPP_INLINE_VISIBILITY
-    constexpr decltype(auto) operator()(_Alts&&... __alts) const {
-      __std_visit_exhaustive_visitor_check<
-          _Visitor,
-          decltype((_VSTD::forward<_Alts>(__alts).__value))...>();
-      return __invoke_constexpr(_VSTD::forward<_Visitor>(__visitor),
-                                _VSTD::forward<_Alts>(__alts).__value...);
-    }
-    _Visitor&& __visitor;
-  };
-
-  template <class _Visitor>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr auto __make_value_visitor(_Visitor&& __visitor) {
-    return __value_visitor<_Visitor>{_VSTD::forward<_Visitor>(__visitor)};
-  }
-};
-
-} // namespace __visitation
-
-template <size_t _Index, class _Tp>
-struct _LIBCPP_TEMPLATE_VIS __alt {
-  using __value_type = _Tp;
-
-  template <class... _Args>
-  inline _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr __alt(in_place_t, _Args&&... __args)
-      : __value(_VSTD::forward<_Args>(__args)...) {}
-
-  __value_type __value;
-};
-
-template <_Trait _DestructibleTrait, size_t _Index, class... _Types>
-union _LIBCPP_TEMPLATE_VIS __union;
-
-template <_Trait _DestructibleTrait, size_t _Index>
-union _LIBCPP_TEMPLATE_VIS __union<_DestructibleTrait, _Index> {};
-
-#define _LIBCPP_VARIANT_UNION(destructible_trait, destructor)                  \
-  template <size_t _Index, class _Tp, class... _Types>                         \
-  union _LIBCPP_TEMPLATE_VIS __union<destructible_trait,                      \
-                                      _Index,                                  \
-                                      _Tp,                                     \
-                                      _Types...> {                             \
-  public:                                                                      \
-    inline _LIBCPP_INLINE_VISIBILITY                                           \
-    explicit constexpr __union(__valueless_t) noexcept : __dummy{} {}          \
-                                                                               \
-    template <class... _Args>                                                  \
-    inline _LIBCPP_INLINE_VISIBILITY                                           \
-    explicit constexpr __union(in_place_index_t<0>, _Args&&... __args)         \
-        : __head(in_place, _VSTD::forward<_Args>(__args)...) {}                \
-                                                                               \
-    template <size_t _Ip, class... _Args>                                      \
-    inline _LIBCPP_INLINE_VISIBILITY                                           \
-    explicit constexpr __union(in_place_index_t<_Ip>, _Args&&... __args)       \
-        : __tail(in_place_index<_Ip - 1>, _VSTD::forward<_Args>(__args)...) {} \
-                                                                               \
-    __union(const __union&) = default;                                         \
-    __union(__union&&) = default;                                              \
-                                                                               \
-    destructor                                                                 \
-                                                                               \
-    __union& operator=(const __union&) = default;                              \
-    __union& operator=(__union&&) = default;                                   \
-                                                                               \
-  private:                                                                     \
-    char __dummy;                                                              \
-    __alt<_Index, _Tp> __head;                                                 \
-    __union<destructible_trait, _Index + 1, _Types...> __tail;                 \
-                                                                               \
-    friend struct __access::__union;                                           \
-  }
-
-_LIBCPP_VARIANT_UNION(_Trait::_TriviallyAvailable, ~__union() = default;);
-_LIBCPP_VARIANT_UNION(_Trait::_Available, ~__union() {});
-_LIBCPP_VARIANT_UNION(_Trait::_Unavailable, ~__union() = delete;);
-
-#undef _LIBCPP_VARIANT_UNION
-
-template <_Trait _DestructibleTrait, class... _Types>
-class _LIBCPP_TEMPLATE_VIS __base {
-public:
-  using __index_t = __variant_index_t<sizeof...(_Types)>;
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr __base(__valueless_t tag) noexcept
-      : __data(tag), __index(__variant_npos<__index_t>) {}
-
-  template <size_t _Ip, class... _Args>
-  inline _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr __base(in_place_index_t<_Ip>, _Args&&... __args)
-      :
-        __data(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...),
-        __index(_Ip) {}
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr bool valueless_by_exception() const noexcept {
-    return index() == variant_npos;
-  }
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr size_t index() const noexcept {
-    return __index == __variant_npos<__index_t> ? variant_npos : __index;
-  }
-
-protected:
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr auto&& __as_base() & { return *this; }
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr auto&& __as_base() && { return _VSTD::move(*this); }
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr auto&& __as_base() const & { return *this; }
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr auto&& __as_base() const && { return _VSTD::move(*this); }
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  static constexpr size_t __size() { return sizeof...(_Types); }
-
-  __union<_DestructibleTrait, 0, _Types...> __data;
-  __index_t __index;
-
-  friend struct __access::__base;
-  friend struct __visitation::__base;
-};
-
-template <class _Traits, _Trait = _Traits::__destructible_trait>
-class _LIBCPP_TEMPLATE_VIS __destructor;
-
-#define _LIBCPP_VARIANT_DESTRUCTOR(destructible_trait, destructor, destroy)    \
-  template <class... _Types>                                                   \
-  class _LIBCPP_TEMPLATE_VIS __destructor<__traits<_Types...>,                 \
-                                           destructible_trait>                 \
-      : public __base<destructible_trait, _Types...> {                         \
-    using __base_type = __base<destructible_trait, _Types...>;                 \
-    using __index_t = typename __base_type::__index_t;                         \
-                                                                               \
-  public:                                                                      \
-    using __base_type::__base_type;                                            \
-    using __base_type::operator=;                                              \
-                                                                               \
-    __destructor(const __destructor&) = default;                               \
-    __destructor(__destructor&&) = default;                                    \
-    destructor                                                                 \
-    __destructor& operator=(const __destructor&) = default;                    \
-    __destructor& operator=(__destructor&&) = default;                         \
-                                                                               \
-  protected:                                                                   \
-    inline _LIBCPP_INLINE_VISIBILITY                                           \
-    destroy                                                                    \
-  }
-
-_LIBCPP_VARIANT_DESTRUCTOR(
-    _Trait::_TriviallyAvailable,
-    ~__destructor() = default;,
-    void __destroy() noexcept { this->__index = __variant_npos<__index_t>; });
-
-_LIBCPP_VARIANT_DESTRUCTOR(
-    _Trait::_Available,
-    ~__destructor() { __destroy(); },
-    void __destroy() noexcept {
-      if (!this->valueless_by_exception()) {
-        __visitation::__base::__visit_alt(
-            [](auto& __alt) noexcept {
-              using __alt_type = __uncvref_t<decltype(__alt)>;
-              __alt.~__alt_type();
-            },
-            *this);
-      }
-      this->__index = __variant_npos<__index_t>;
-    });
-
-_LIBCPP_VARIANT_DESTRUCTOR(
-    _Trait::_Unavailable,
-    ~__destructor() = delete;,
-    void __destroy() noexcept = delete;);
-
-#undef _LIBCPP_VARIANT_DESTRUCTOR
-
-template <class _Traits>
-class _LIBCPP_TEMPLATE_VIS __constructor : public __destructor<_Traits> {
-  using __base_type = __destructor<_Traits>;
-
-public:
-  using __base_type::__base_type;
-  using __base_type::operator=;
-
-protected:
-  template <size_t _Ip, class _Tp, class... _Args>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static _Tp& __construct_alt(__alt<_Ip, _Tp>& __a, _Args&&... __args) {
-    ::new ((void*)_VSTD::addressof(__a))
-        __alt<_Ip, _Tp>(in_place, _VSTD::forward<_Args>(__args)...);
-    return __a.__value;
-  }
-
-  template <class _Rhs>
-  inline _LIBCPP_INLINE_VISIBILITY
-  static void __generic_construct(__constructor& __lhs, _Rhs&& __rhs) {
-    __lhs.__destroy();
-    if (!__rhs.valueless_by_exception()) {
-      __visitation::__base::__visit_alt_at(
-          __rhs.index(),
-          [](auto& __lhs_alt, auto&& __rhs_alt) {
-            __construct_alt(
-                __lhs_alt,
-                _VSTD::forward<decltype(__rhs_alt)>(__rhs_alt).__value);
-          },
-          __lhs, _VSTD::forward<_Rhs>(__rhs));
-      __lhs.__index = __rhs.index();
-    }
-  }
-};
-
-template <class _Traits, _Trait = _Traits::__move_constructible_trait>
-class _LIBCPP_TEMPLATE_VIS __move_constructor;
-
-#define _LIBCPP_VARIANT_MOVE_CONSTRUCTOR(move_constructible_trait,             \
-                                         move_constructor)                     \
-  template <class... _Types>                                                   \
-  class _LIBCPP_TEMPLATE_VIS __move_constructor<__traits<_Types...>,          \
-                                                 move_constructible_trait>     \
-      : public __constructor<__traits<_Types...>> {                            \
-    using __base_type = __constructor<__traits<_Types...>>;                    \
-                                                                               \
-  public:                                                                      \
-    using __base_type::__base_type;                                            \
-    using __base_type::operator=;                                              \
-                                                                               \
-    __move_constructor(const __move_constructor&) = default;                   \
-    move_constructor                                                           \
-    ~__move_constructor() = default;                                           \
-    __move_constructor& operator=(const __move_constructor&) = default;        \
-    __move_constructor& operator=(__move_constructor&&) = default;             \
-  }
-
-_LIBCPP_VARIANT_MOVE_CONSTRUCTOR(
-    _Trait::_TriviallyAvailable,
-    __move_constructor(__move_constructor&& __that) = default;);
-
-_LIBCPP_VARIANT_MOVE_CONSTRUCTOR(
-    _Trait::_Available,
-    __move_constructor(__move_constructor&& __that) noexcept(
-        __all<is_nothrow_move_constructible_v<_Types>...>::value)
-        : __move_constructor(__valueless_t{}) {
-      this->__generic_construct(*this, _VSTD::move(__that));
-    });
-
-_LIBCPP_VARIANT_MOVE_CONSTRUCTOR(
-    _Trait::_Unavailable,
-    __move_constructor(__move_constructor&&) = delete;);
-
-#undef _LIBCPP_VARIANT_MOVE_CONSTRUCTOR
-
-template <class _Traits, _Trait = _Traits::__copy_constructible_trait>
-class _LIBCPP_TEMPLATE_VIS __copy_constructor;
-
-#define _LIBCPP_VARIANT_COPY_CONSTRUCTOR(copy_constructible_trait,             \
-                                         copy_constructor)                     \
-  template <class... _Types>                                                   \
-  class _LIBCPP_TEMPLATE_VIS __copy_constructor<__traits<_Types...>,          \
-                                                 copy_constructible_trait>     \
-      : public __move_constructor<__traits<_Types...>> {                       \
-    using __base_type = __move_constructor<__traits<_Types...>>;               \
-                                                                               \
-  public:                                                                      \
-    using __base_type::__base_type;                                            \
-    using __base_type::operator=;                                              \
-                                                                               \
-    copy_constructor                                                           \
-    __copy_constructor(__copy_constructor&&) = default;                        \
-    ~__copy_constructor() = default;                                           \
-    __copy_constructor& operator=(const __copy_constructor&) = default;        \
-    __copy_constructor& operator=(__copy_constructor&&) = default;             \
-  }
-
-_LIBCPP_VARIANT_COPY_CONSTRUCTOR(
-    _Trait::_TriviallyAvailable,
-    __copy_constructor(const __copy_constructor& __that) = default;);
-
-_LIBCPP_VARIANT_COPY_CONSTRUCTOR(
-    _Trait::_Available,
-    __copy_constructor(const __copy_constructor& __that)
-        : __copy_constructor(__valueless_t{}) {
-      this->__generic_construct(*this, __that);
-    });
-
-_LIBCPP_VARIANT_COPY_CONSTRUCTOR(
-    _Trait::_Unavailable,
-    __copy_constructor(const __copy_constructor&) = delete;);
-
-#undef _LIBCPP_VARIANT_COPY_CONSTRUCTOR
-
-template <class _Traits>
-class _LIBCPP_TEMPLATE_VIS __assignment : public __copy_constructor<_Traits> {
-  using __base_type = __copy_constructor<_Traits>;
-
-public:
-  using __base_type::__base_type;
-  using __base_type::operator=;
-
-  template <size_t _Ip, class... _Args>
-  inline _LIBCPP_INLINE_VISIBILITY
-  auto& __emplace(_Args&&... __args) {
-    this->__destroy();
-    auto& __res = this->__construct_alt(__access::__base::__get_alt<_Ip>(*this),
-                          _VSTD::forward<_Args>(__args)...);
-    this->__index = _Ip;
-    return __res;
-  }
-
-protected:
-  template <size_t _Ip, class _Tp, class _Arg>
-  inline _LIBCPP_INLINE_VISIBILITY
-  void __assign_alt(__alt<_Ip, _Tp>& __a, _Arg&& __arg) {
-    if (this->index() == _Ip) {
-      __a.__value = _VSTD::forward<_Arg>(__arg);
-    } else {
-      struct {
-        void operator()(true_type) const {
-          __this->__emplace<_Ip>(_VSTD::forward<_Arg>(__arg));
-        }
-        void operator()(false_type) const {
-          __this->__emplace<_Ip>(_Tp(_VSTD::forward<_Arg>(__arg)));
-        }
-        __assignment* __this;
-        _Arg&& __arg;
-      } __impl{this, _VSTD::forward<_Arg>(__arg)};
-      __impl(bool_constant<is_nothrow_constructible_v<_Tp, _Arg> ||
-                           !is_nothrow_move_constructible_v<_Tp>>{});
-    }
-  }
-
-  template <class _That>
-  inline _LIBCPP_INLINE_VISIBILITY
-  void __generic_assign(_That&& __that) {
-    if (this->valueless_by_exception() && __that.valueless_by_exception()) {
-      // do nothing.
-    } else if (__that.valueless_by_exception()) {
-      this->__destroy();
-    } else {
-      __visitation::__base::__visit_alt_at(
-          __that.index(),
-          [this](auto& __this_alt, auto&& __that_alt) {
-            this->__assign_alt(
-                __this_alt,
-                _VSTD::forward<decltype(__that_alt)>(__that_alt).__value);
-          },
-          *this, _VSTD::forward<_That>(__that));
-    }
-  }
-};
-
-template <class _Traits, _Trait = _Traits::__move_assignable_trait>
-class _LIBCPP_TEMPLATE_VIS __move_assignment;
-
-#define _LIBCPP_VARIANT_MOVE_ASSIGNMENT(move_assignable_trait,                 \
-                                        move_assignment)                       \
-  template <class... _Types>                                                   \
-  class _LIBCPP_TEMPLATE_VIS __move_assignment<__traits<_Types...>,           \
-                                                move_assignable_trait>         \
-      : public __assignment<__traits<_Types...>> {                             \
-    using __base_type = __assignment<__traits<_Types...>>;                     \
-                                                                               \
-  public:                                                                      \
-    using __base_type::__base_type;                                            \
-    using __base_type::operator=;                                              \
-                                                                               \
-    __move_assignment(const __move_assignment&) = default;                     \
-    __move_assignment(__move_assignment&&) = default;                          \
-    ~__move_assignment() = default;                                            \
-    __move_assignment& operator=(const __move_assignment&) = default;          \
-    move_assignment                                                            \
-  }
-
-_LIBCPP_VARIANT_MOVE_ASSIGNMENT(
-    _Trait::_TriviallyAvailable,
-    __move_assignment& operator=(__move_assignment&& __that) = default;);
-
-_LIBCPP_VARIANT_MOVE_ASSIGNMENT(
-    _Trait::_Available,
-    __move_assignment& operator=(__move_assignment&& __that) noexcept(
-        __all<(is_nothrow_move_constructible_v<_Types> &&
-               is_nothrow_move_assignable_v<_Types>)...>::value) {
-      this->__generic_assign(_VSTD::move(__that));
-      return *this;
-    });
-
-_LIBCPP_VARIANT_MOVE_ASSIGNMENT(
-    _Trait::_Unavailable,
-    __move_assignment& operator=(__move_assignment&&) = delete;);
-
-#undef _LIBCPP_VARIANT_MOVE_ASSIGNMENT
-
-template <class _Traits, _Trait = _Traits::__copy_assignable_trait>
-class _LIBCPP_TEMPLATE_VIS __copy_assignment;
-
-#define _LIBCPP_VARIANT_COPY_ASSIGNMENT(copy_assignable_trait,                 \
-                                        copy_assignment)                       \
-  template <class... _Types>                                                   \
-  class _LIBCPP_TEMPLATE_VIS __copy_assignment<__traits<_Types...>,           \
-                                                copy_assignable_trait>         \
-      : public __move_assignment<__traits<_Types...>> {                        \
-    using __base_type = __move_assignment<__traits<_Types...>>;                \
-                                                                               \
-  public:                                                                      \
-    using __base_type::__base_type;                                            \
-    using __base_type::operator=;                                              \
-                                                                               \
-    __copy_assignment(const __copy_assignment&) = default;                     \
-    __copy_assignment(__copy_assignment&&) = default;                          \
-    ~__copy_assignment() = default;                                            \
-    copy_assignment                                                            \
-    __copy_assignment& operator=(__copy_assignment&&) = default;               \
-  }
-
-_LIBCPP_VARIANT_COPY_ASSIGNMENT(
-    _Trait::_TriviallyAvailable,
-    __copy_assignment& operator=(const __copy_assignment& __that) = default;);
-
-_LIBCPP_VARIANT_COPY_ASSIGNMENT(
-    _Trait::_Available,
-    __copy_assignment& operator=(const __copy_assignment& __that) {
-      this->__generic_assign(__that);
-      return *this;
-    });
-
-_LIBCPP_VARIANT_COPY_ASSIGNMENT(
-    _Trait::_Unavailable,
-    __copy_assignment& operator=(const __copy_assignment&) = delete;);
-
-#undef _LIBCPP_VARIANT_COPY_ASSIGNMENT
-
-template <class... _Types>
-class _LIBCPP_TEMPLATE_VIS __impl
-    : public __copy_assignment<__traits<_Types...>> {
-  using __base_type = __copy_assignment<__traits<_Types...>>;
-
-public:
-  using __base_type::__base_type;
-  using __base_type::operator=;
-
-  template <size_t _Ip, class _Arg>
-  inline _LIBCPP_INLINE_VISIBILITY
-  void __assign(_Arg&& __arg) {
-    this->__assign_alt(__access::__base::__get_alt<_Ip>(*this),
-                       _VSTD::forward<_Arg>(__arg));
-  }
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  void __swap(__impl& __that)  {
-    if (this->valueless_by_exception() && __that.valueless_by_exception()) {
-      // do nothing.
-    } else if (this->index() == __that.index()) {
-      __visitation::__base::__visit_alt_at(
-          this->index(),
-          [](auto& __this_alt, auto& __that_alt) {
-            using _VSTD::swap;
-            swap(__this_alt.__value, __that_alt.__value);
-          },
-          *this,
-          __that);
-    } else {
-      __impl* __lhs = this;
-      __impl* __rhs = _VSTD::addressof(__that);
-      if (__lhs->__move_nothrow() && !__rhs->__move_nothrow()) {
-        _VSTD::swap(__lhs, __rhs);
-      }
-      __impl __tmp(_VSTD::move(*__rhs));
-#ifndef _LIBCPP_NO_EXCEPTIONS
-      // EXTENSION: When the move construction of `__lhs` into `__rhs` throws
-      // and `__tmp` is nothrow move constructible then we move `__tmp` back
-      // into `__rhs` and provide the strong exception safety guarantee.
-      try {
-        this->__generic_construct(*__rhs, _VSTD::move(*__lhs));
-      } catch (...) {
-        if (__tmp.__move_nothrow()) {
-          this->__generic_construct(*__rhs, _VSTD::move(__tmp));
-        }
-        throw;
-      }
-#else
-      this->__generic_construct(*__rhs, _VSTD::move(*__lhs));
-#endif
-      this->__generic_construct(*__lhs, _VSTD::move(__tmp));
-    }
-  }
-
-private:
-  inline _LIBCPP_INLINE_VISIBILITY
-  bool __move_nothrow() const {
-    constexpr bool __results[] = {is_nothrow_move_constructible_v<_Types>...};
-    return this->valueless_by_exception() || __results[this->index()];
-  }
-};
-
-template <class... _Types>
-struct __overload;
-
-template <>
-struct __overload<> { void operator()() const; };
-
-template <class _Tp, class... _Types>
-struct __overload<_Tp, _Types...> : __overload<_Types...> {
-  using __overload<_Types...>::operator();
-  __identity<_Tp> operator()(_Tp) const;
-};
-
-template <class _Tp, class... _Types>
-using __best_match_t = typename result_of_t<__overload<_Types...>(_Tp&&)>::type;
-
-} // __variant_detail
-
-template <class... _Types>
-class _LIBCPP_TEMPLATE_VIS variant
-    : private __sfinae_ctor_base<
-          __all<is_copy_constructible_v<_Types>...>::value,
-          __all<is_move_constructible_v<_Types>...>::value>,
-      private __sfinae_assign_base<
-          __all<(is_copy_constructible_v<_Types> &&
-                 is_copy_assignable_v<_Types>)...>::value,
-          __all<(is_move_constructible_v<_Types> &&
-                 is_move_assignable_v<_Types>)...>::value> {
-  static_assert(0 < sizeof...(_Types),
-                "variant must consist of at least one alternative.");
-
-  static_assert(__all<!is_array_v<_Types>...>::value,
-                "variant can not have an array type as an alternative.");
-
-  static_assert(__all<!is_reference_v<_Types>...>::value,
-                "variant can not have a reference type as an alternative.");
-
-  static_assert(__all<!is_void_v<_Types>...>::value,
-                "variant can not have a void type as an alternative.");
-
-  using __first_type = variant_alternative_t<0, variant>;
-
-public:
-  template <bool _Dummy = true,
-            enable_if_t<__dependent_type<is_default_constructible<__first_type>,
-                                         _Dummy>::value,
-                        int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr variant() noexcept(is_nothrow_default_constructible_v<__first_type>)
-      : __impl(in_place_index<0>) {}
-
-  variant(const variant&) = default;
-  variant(variant&&) = default;
-
-  template <
-      class _Arg,
-      enable_if_t<!is_same_v<__uncvref_t<_Arg>, variant>, int> = 0,
-      enable_if_t<!__is_inplace_type<__uncvref_t<_Arg>>::value, int> = 0,
-      enable_if_t<!__is_inplace_index<__uncvref_t<_Arg>>::value, int> = 0,
-      class _Tp = __variant_detail::__best_match_t<_Arg, _Types...>,
-      size_t _Ip =
-          __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
-      enable_if_t<is_constructible_v<_Tp, _Arg>, int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr variant(_Arg&& __arg) noexcept(
-      is_nothrow_constructible_v<_Tp, _Arg>)
-      : __impl(in_place_index<_Ip>, _VSTD::forward<_Arg>(__arg)) {}
-
-  template <size_t _Ip, class... _Args,
-            class = enable_if_t<(_Ip < sizeof...(_Types)), int>,
-            class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
-            enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr variant(
-      in_place_index_t<_Ip>,
-      _Args&&... __args) noexcept(is_nothrow_constructible_v<_Tp, _Args...>)
-      : __impl(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...) {}
-
-  template <
-      size_t _Ip,
-      class _Up,
-      class... _Args,
-      enable_if_t<(_Ip < sizeof...(_Types)), int> = 0,
-      class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
-      enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
-                  int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr variant(
-      in_place_index_t<_Ip>,
-      initializer_list<_Up> __il,
-      _Args&&... __args) noexcept(
-      is_nothrow_constructible_v<_Tp, initializer_list<_Up>&, _Args...>)
-      : __impl(in_place_index<_Ip>, __il, _VSTD::forward<_Args>(__args)...) {}
-
-  template <
-      class _Tp,
-      class... _Args,
-      size_t _Ip =
-          __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
-      enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr variant(in_place_type_t<_Tp>, _Args&&... __args) noexcept(
-      is_nothrow_constructible_v<_Tp, _Args...>)
-      : __impl(in_place_index<_Ip>, _VSTD::forward<_Args>(__args)...) {}
-
-  template <
-      class _Tp,
-      class _Up,
-      class... _Args,
-      size_t _Ip =
-          __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
-      enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
-                  int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  explicit constexpr variant(
-      in_place_type_t<_Tp>,
-      initializer_list<_Up> __il,
-      _Args&&... __args) noexcept(
-      is_nothrow_constructible_v<_Tp, initializer_list< _Up>&, _Args...>)
-      : __impl(in_place_index<_Ip>, __il, _VSTD::forward<_Args>(__args)...) {}
-
-  ~variant() = default;
-
-  variant& operator=(const variant&) = default;
-  variant& operator=(variant&&) = default;
-
-  template <
-      class _Arg,
-      enable_if_t<!is_same_v<__uncvref_t<_Arg>, variant>, int> = 0,
-      class _Tp = __variant_detail::__best_match_t<_Arg, _Types...>,
-      size_t _Ip =
-          __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
-      enable_if_t<is_assignable_v<_Tp&, _Arg> && is_constructible_v<_Tp, _Arg>,
-                  int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  variant& operator=(_Arg&& __arg) noexcept(
-      is_nothrow_assignable_v<_Tp&, _Arg> &&
-      is_nothrow_constructible_v<_Tp, _Arg>) {
-    __impl.template __assign<_Ip>(_VSTD::forward<_Arg>(__arg));
-    return *this;
-  }
-
-  template <
-      size_t _Ip,
-      class... _Args,
-      enable_if_t<(_Ip < sizeof...(_Types)), int> = 0,
-      class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
-      enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  _Tp& emplace(_Args&&... __args) {
-    return __impl.template __emplace<_Ip>(_VSTD::forward<_Args>(__args)...);
-  }
-
-  template <
-      size_t _Ip,
-      class _Up,
-      class... _Args,
-      enable_if_t<(_Ip < sizeof...(_Types)), int> = 0,
-      class _Tp = variant_alternative_t<_Ip, variant<_Types...>>,
-      enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
-                  int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) {
-    return __impl.template __emplace<_Ip>(__il, _VSTD::forward<_Args>(__args)...);
-  }
-
-  template <
-      class _Tp,
-      class... _Args,
-      size_t _Ip =
-          __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
-      enable_if_t<is_constructible_v<_Tp, _Args...>, int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  _Tp& emplace(_Args&&... __args) {
-    return __impl.template __emplace<_Ip>(_VSTD::forward<_Args>(__args)...);
-  }
-
-  template <
-      class _Tp,
-      class _Up,
-      class... _Args,
-      size_t _Ip =
-          __find_detail::__find_unambiguous_index_sfinae<_Tp, _Types...>::value,
-      enable_if_t<is_constructible_v<_Tp, initializer_list<_Up>&, _Args...>,
-                  int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  _Tp& emplace(initializer_list<_Up> __il, _Args&&... __args) {
-    return __impl.template __emplace<_Ip>(__il, _VSTD::forward<_Args>(__args)...);
-  }
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr bool valueless_by_exception() const noexcept {
-    return __impl.valueless_by_exception();
-  }
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  constexpr size_t index() const noexcept { return __impl.index(); }
-
-  template <
-      bool _Dummy = true,
-      enable_if_t<
-          __all<(
-              __dependent_type<is_move_constructible<_Types>, _Dummy>::value &&
-              __dependent_type<is_swappable<_Types>, _Dummy>::value)...>::value,
-          int> = 0>
-  inline _LIBCPP_INLINE_VISIBILITY
-  void swap(variant& __that) noexcept(
-      __all<(is_nothrow_move_constructible_v<_Types> &&
-             is_nothrow_swappable_v<_Types>)...>::value) {
-    __impl.__swap(__that.__impl);
-  }
-
-private:
-  __variant_detail::__impl<_Types...> __impl;
-
-  friend struct __variant_detail::__access::__variant;
-  friend struct __variant_detail::__visitation::__variant;
-};
-
-template <size_t _Ip, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool __holds_alternative(const variant<_Types...>& __v) noexcept {
-  return __v.index() == _Ip;
-}
-
-template <class _Tp, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool holds_alternative(const variant<_Types...>& __v) noexcept {
-  return __holds_alternative<__find_exactly_one_t<_Tp, _Types...>::value>(__v);
-}
-
-template <size_t _Ip, class _Vp>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr auto&& __generic_get(_Vp&& __v) {
-  using __variant_detail::__access::__variant;
-  if (!__holds_alternative<_Ip>(__v)) {
-    __throw_bad_variant_access();
-  }
-  return __variant::__get_alt<_Ip>(_VSTD::forward<_Vp>(__v)).__value;
-}
-
-template <size_t _Ip, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr variant_alternative_t<_Ip, variant<_Types...>>& get(
-    variant<_Types...>& __v) {
-  static_assert(_Ip < sizeof...(_Types));
-  static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>);
-  return __generic_get<_Ip>(__v);
-}
-
-template <size_t _Ip, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr variant_alternative_t<_Ip, variant<_Types...>>&& get(
-    variant<_Types...>&& __v) {
-  static_assert(_Ip < sizeof...(_Types));
-  static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>);
-  return __generic_get<_Ip>(_VSTD::move(__v));
-}
-
-template <size_t _Ip, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr const variant_alternative_t<_Ip, variant<_Types...>>& get(
-    const variant<_Types...>& __v) {
-  static_assert(_Ip < sizeof...(_Types));
-  static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>);
-  return __generic_get<_Ip>(__v);
-}
-
-template <size_t _Ip, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr const variant_alternative_t<_Ip, variant<_Types...>>&& get(
-    const variant<_Types...>&& __v) {
-  static_assert(_Ip < sizeof...(_Types));
-  static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>);
-  return __generic_get<_Ip>(_VSTD::move(__v));
-}
-
-template <class _Tp, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr _Tp& get(variant<_Types...>& __v) {
-  static_assert(!is_void_v<_Tp>);
-  return _VSTD::get<__find_exactly_one_t<_Tp, _Types...>::value>(__v);
-}
-
-template <class _Tp, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr _Tp&& get(variant<_Types...>&& __v) {
-  static_assert(!is_void_v<_Tp>);
-  return _VSTD::get<__find_exactly_one_t<_Tp, _Types...>::value>(
-      _VSTD::move(__v));
-}
-
-template <class _Tp, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr const _Tp& get(const variant<_Types...>& __v) {
-  static_assert(!is_void_v<_Tp>);
-  return _VSTD::get<__find_exactly_one_t<_Tp, _Types...>::value>(__v);
-}
-
-template <class _Tp, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr const _Tp&& get(const variant<_Types...>&& __v) {
-  static_assert(!is_void_v<_Tp>);
-  return _VSTD::get<__find_exactly_one_t<_Tp, _Types...>::value>(
-      _VSTD::move(__v));
-}
-
-template <size_t _Ip, class _Vp>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr auto* __generic_get_if(_Vp* __v) noexcept {
-  using __variant_detail::__access::__variant;
-  return __v && __holds_alternative<_Ip>(*__v)
-             ? _VSTD::addressof(__variant::__get_alt<_Ip>(*__v).__value)
-             : nullptr;
-}
-
-template <size_t _Ip, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr add_pointer_t<variant_alternative_t<_Ip, variant<_Types...>>>
-get_if(variant<_Types...>* __v) noexcept {
-  static_assert(_Ip < sizeof...(_Types));
-  static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>);
-  return __generic_get_if<_Ip>(__v);
-}
-
-template <size_t _Ip, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr add_pointer_t<const variant_alternative_t<_Ip, variant<_Types...>>>
-get_if(const variant<_Types...>* __v) noexcept {
-  static_assert(_Ip < sizeof...(_Types));
-  static_assert(!is_void_v<variant_alternative_t<_Ip, variant<_Types...>>>);
-  return __generic_get_if<_Ip>(__v);
-}
-
-template <class _Tp, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr add_pointer_t<_Tp>
-get_if(variant<_Types...>* __v) noexcept {
-  static_assert(!is_void_v<_Tp>);
-  return _VSTD::get_if<__find_exactly_one_t<_Tp, _Types...>::value>(__v);
-}
-
-template <class _Tp, class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr add_pointer_t<const _Tp>
-get_if(const variant<_Types...>* __v) noexcept {
-  static_assert(!is_void_v<_Tp>);
-  return _VSTD::get_if<__find_exactly_one_t<_Tp, _Types...>::value>(__v);
-}
-
-template <class _Operator>
-struct __convert_to_bool {
-  template <class _T1, class _T2>
-  _LIBCPP_INLINE_VISIBILITY constexpr bool operator()(_T1 && __t1, _T2&& __t2) const {
-    static_assert(std::is_convertible<decltype(_Operator{}(_VSTD::forward<_T1>(__t1), _VSTD::forward<_T2>(__t2))), bool>::value,
-        "the relational operator does not return a type which is implicitly convertible to bool");
-    return _Operator{}(_VSTD::forward<_T1>(__t1), _VSTD::forward<_T2>(__t2));
-  }
-};
-
-template <class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(const variant<_Types...>& __lhs,
-                          const variant<_Types...>& __rhs) {
-  using __variant_detail::__visitation::__variant;
-  if (__lhs.index() != __rhs.index()) return false;
-  if (__lhs.valueless_by_exception()) return true;
-  return __variant::__visit_value_at(__lhs.index(), __convert_to_bool<equal_to<>>{}, __lhs, __rhs);
-}
-
-template <class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(const variant<_Types...>& __lhs,
-                          const variant<_Types...>& __rhs) {
-  using __variant_detail::__visitation::__variant;
-  if (__lhs.index() != __rhs.index()) return true;
-  if (__lhs.valueless_by_exception()) return false;
-  return __variant::__visit_value_at(
-      __lhs.index(), __convert_to_bool<not_equal_to<>>{}, __lhs, __rhs);
-}
-
-template <class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<(const variant<_Types...>& __lhs,
-                         const variant<_Types...>& __rhs) {
-  using __variant_detail::__visitation::__variant;
-  if (__rhs.valueless_by_exception()) return false;
-  if (__lhs.valueless_by_exception()) return true;
-  if (__lhs.index() < __rhs.index()) return true;
-  if (__lhs.index() > __rhs.index()) return false;
-  return __variant::__visit_value_at(__lhs.index(), __convert_to_bool<less<>>{}, __lhs, __rhs);
-}
-
-template <class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>(const variant<_Types...>& __lhs,
-                         const variant<_Types...>& __rhs) {
-  using __variant_detail::__visitation::__variant;
-  if (__lhs.valueless_by_exception()) return false;
-  if (__rhs.valueless_by_exception()) return true;
-  if (__lhs.index() > __rhs.index()) return true;
-  if (__lhs.index() < __rhs.index()) return false;
-  return __variant::__visit_value_at(__lhs.index(), __convert_to_bool<greater<>>{}, __lhs, __rhs);
-}
-
-template <class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<=(const variant<_Types...>& __lhs,
-                          const variant<_Types...>& __rhs) {
-  using __variant_detail::__visitation::__variant;
-  if (__lhs.valueless_by_exception()) return true;
-  if (__rhs.valueless_by_exception()) return false;
-  if (__lhs.index() < __rhs.index()) return true;
-  if (__lhs.index() > __rhs.index()) return false;
-  return __variant::__visit_value_at(
-      __lhs.index(), __convert_to_bool<less_equal<>>{}, __lhs, __rhs);
-}
-
-template <class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>=(const variant<_Types...>& __lhs,
-                          const variant<_Types...>& __rhs) {
-  using __variant_detail::__visitation::__variant;
-  if (__rhs.valueless_by_exception()) return true;
-  if (__lhs.valueless_by_exception()) return false;
-  if (__lhs.index() > __rhs.index()) return true;
-  if (__lhs.index() < __rhs.index()) return false;
-  return __variant::__visit_value_at(
-      __lhs.index(), __convert_to_bool<greater_equal<>>{}, __lhs, __rhs);
-}
-
-template <class _Visitor, class... _Vs>
-inline _LIBCPP_INLINE_VISIBILITY
-_LIBCPP_AVAILABILITY_THROW_BAD_VARIANT_ACCESS
-constexpr decltype(auto) visit(_Visitor&& __visitor, _Vs&&... __vs) {
-  using __variant_detail::__visitation::__variant;
-  bool __results[] = {__vs.valueless_by_exception()...};
-  for (bool __result : __results) {
-    if (__result) {
-      __throw_bad_variant_access();
-    }
-  }
-  return __variant::__visit_value(_VSTD::forward<_Visitor>(__visitor),
-                                  _VSTD::forward<_Vs>(__vs)...);
-}
-
-struct _LIBCPP_TEMPLATE_VIS monostate {};
-
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<(monostate, monostate) noexcept { return false; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>(monostate, monostate) noexcept { return false; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator<=(monostate, monostate) noexcept { return true; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator>=(monostate, monostate) noexcept { return true; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator==(monostate, monostate) noexcept { return true; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-constexpr bool operator!=(monostate, monostate) noexcept { return false; }
-
-template <class... _Types>
-inline _LIBCPP_INLINE_VISIBILITY
-auto swap(variant<_Types...>& __lhs,
-          variant<_Types...>& __rhs) noexcept(noexcept(__lhs.swap(__rhs)))
-    -> decltype(__lhs.swap(__rhs)) {
-  __lhs.swap(__rhs);
-}
-
-template <class... _Types>
-struct _LIBCPP_TEMPLATE_VIS hash<
-    __enable_hash_helper<variant<_Types...>, remove_const_t<_Types>...>> {
-  using argument_type = variant<_Types...>;
-  using result_type = size_t;
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  result_type operator()(const argument_type& __v) const {
-    using __variant_detail::__visitation::__variant;
-    size_t __res =
-        __v.valueless_by_exception()
-               ? 299792458 // Random value chosen by the universe upon creation
-               : __variant::__visit_alt(
-                     [](const auto& __alt) {
-                       using __alt_type = __uncvref_t<decltype(__alt)>;
-                       using __value_type = remove_const_t<
-                         typename __alt_type::__value_type>;
-                       return hash<__value_type>{}(__alt.__value);
-                     },
-                     __v);
-    return __hash_combine(__res, hash<size_t>{}(__v.index()));
-  }
-};
-
-template <>
-struct _LIBCPP_TEMPLATE_VIS hash<monostate> {
-  using argument_type = monostate;
-  using result_type = size_t;
-
-  inline _LIBCPP_INLINE_VISIBILITY
-  result_type operator()(const argument_type&) const _NOEXCEPT {
-    return 66740831; // return a fundamentally attractive random value.
-  }
-};
-
-#endif  // _LIBCPP_STD_VER > 14
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_VARIANT
diff --git a/lib/libcxx/include/vector b/lib/libcxx/include/vector
deleted file mode 100644
index edb6d3e09f5..00000000000
--- a/lib/libcxx/include/vector
+++ /dev/null
@@ -1,3432 +0,0 @@
-// -*- C++ -*-
-//===------------------------------ vector --------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_VECTOR
-#define _LIBCPP_VECTOR
-
-/*
-    vector synopsis
-
-namespace std
-{
-
-template <class T, class Allocator = allocator<T> >
-class vector
-{
-public:
-    typedef T                                        value_type;
-    typedef Allocator                                allocator_type;
-    typedef typename allocator_type::reference       reference;
-    typedef typename allocator_type::const_reference const_reference;
-    typedef implementation-defined                   iterator;
-    typedef implementation-defined                   const_iterator;
-    typedef typename allocator_type::size_type       size_type;
-    typedef typename allocator_type::difference_type difference_type;
-    typedef typename allocator_type::pointer         pointer;
-    typedef typename allocator_type::const_pointer   const_pointer;
-    typedef std::reverse_iterator<iterator>          reverse_iterator;
-    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
-
-    vector()
-        noexcept(is_nothrow_default_constructible<allocator_type>::value);
-    explicit vector(const allocator_type&);
-    explicit vector(size_type n);
-    explicit vector(size_type n, const allocator_type&); // C++14
-    vector(size_type n, const value_type& value, const allocator_type& = allocator_type());
-    template <class InputIterator>
-        vector(InputIterator first, InputIterator last, const allocator_type& = allocator_type());
-    vector(const vector& x);
-    vector(vector&& x)
-        noexcept(is_nothrow_move_constructible<allocator_type>::value);
-    vector(initializer_list<value_type> il);
-    vector(initializer_list<value_type> il, const allocator_type& a);
-    ~vector();
-    vector& operator=(const vector& x);
-    vector& operator=(vector&& x)
-        noexcept(
-             allocator_type::propagate_on_container_move_assignment::value ||
-             allocator_type::is_always_equal::value); // C++17
-    vector& operator=(initializer_list<value_type> il);
-    template <class InputIterator>
-        void assign(InputIterator first, InputIterator last);
-    void assign(size_type n, const value_type& u);
-    void assign(initializer_list<value_type> il);
-
-    allocator_type get_allocator() const noexcept;
-
-    iterator               begin() noexcept;
-    const_iterator         begin()   const noexcept;
-    iterator               end() noexcept;
-    const_iterator         end()     const noexcept;
-
-    reverse_iterator       rbegin() noexcept;
-    const_reverse_iterator rbegin()  const noexcept;
-    reverse_iterator       rend() noexcept;
-    const_reverse_iterator rend()    const noexcept;
-
-    const_iterator         cbegin()  const noexcept;
-    const_iterator         cend()    const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend()   const noexcept;
-
-    size_type size() const noexcept;
-    size_type max_size() const noexcept;
-    size_type capacity() const noexcept;
-    bool empty() const noexcept;
-    void reserve(size_type n);
-    void shrink_to_fit() noexcept;
-
-    reference       operator[](size_type n);
-    const_reference operator[](size_type n) const;
-    reference       at(size_type n);
-    const_reference at(size_type n) const;
-
-    reference       front();
-    const_reference front() const;
-    reference       back();
-    const_reference back() const;
-
-    value_type*       data() noexcept;
-    const value_type* data() const noexcept;
-
-    void push_back(const value_type& x);
-    void push_back(value_type&& x);
-    template <class... Args>
-        reference emplace_back(Args&&... args); // reference in C++17
-    void pop_back();
-
-    template <class... Args> iterator emplace(const_iterator position, Args&&... args);
-    iterator insert(const_iterator position, const value_type& x);
-    iterator insert(const_iterator position, value_type&& x);
-    iterator insert(const_iterator position, size_type n, const value_type& x);
-    template <class InputIterator>
-        iterator insert(const_iterator position, InputIterator first, InputIterator last);
-    iterator insert(const_iterator position, initializer_list<value_type> il);
-
-    iterator erase(const_iterator position);
-    iterator erase(const_iterator first, const_iterator last);
-
-    void clear() noexcept;
-
-    void resize(size_type sz);
-    void resize(size_type sz, const value_type& c);
-
-    void swap(vector&)
-        noexcept(allocator_traits<allocator_type>::propagate_on_container_swap::value ||
-                 allocator_traits<allocator_type>::is_always_equal::value);  // C++17
-
-    bool __invariants() const;
-};
-
-template <class Allocator = allocator<T> >
-class vector<bool, Allocator>
-{
-public:
-    typedef bool                                     value_type;
-    typedef Allocator                                allocator_type;
-    typedef implementation-defined                   iterator;
-    typedef implementation-defined                   const_iterator;
-    typedef typename allocator_type::size_type       size_type;
-    typedef typename allocator_type::difference_type difference_type;
-    typedef iterator                                 pointer;
-    typedef const_iterator                           const_pointer;
-    typedef std::reverse_iterator<iterator>          reverse_iterator;
-    typedef std::reverse_iterator<const_iterator>    const_reverse_iterator;
-
-    class reference
-    {
-    public:
-        reference(const reference&) noexcept;
-        operator bool() const noexcept;
-        reference& operator=(const bool x) noexcept;
-        reference& operator=(const reference& x) noexcept;
-        iterator operator&() const noexcept;
-        void flip() noexcept;
-    };
-
-    class const_reference
-    {
-    public:
-        const_reference(const reference&) noexcept;
-        operator bool() const noexcept;
-        const_iterator operator&() const noexcept;
-    };
-
-    vector()
-        noexcept(is_nothrow_default_constructible<allocator_type>::value);
-    explicit vector(const allocator_type&);
-    explicit vector(size_type n, const allocator_type& a = allocator_type()); // C++14
-    vector(size_type n, const value_type& value, const allocator_type& = allocator_type());
-    template <class InputIterator>
-        vector(InputIterator first, InputIterator last, const allocator_type& = allocator_type());
-    vector(const vector& x);
-    vector(vector&& x)
-        noexcept(is_nothrow_move_constructible<allocator_type>::value);
-    vector(initializer_list<value_type> il);
-    vector(initializer_list<value_type> il, const allocator_type& a);
-    ~vector();
-    vector& operator=(const vector& x);
-    vector& operator=(vector&& x)
-        noexcept(
-             allocator_type::propagate_on_container_move_assignment::value ||
-             allocator_type::is_always_equal::value); // C++17
-    vector& operator=(initializer_list<value_type> il);
-    template <class InputIterator>
-        void assign(InputIterator first, InputIterator last);
-    void assign(size_type n, const value_type& u);
-    void assign(initializer_list<value_type> il);
-
-    allocator_type get_allocator() const noexcept;
-
-    iterator               begin() noexcept;
-    const_iterator         begin()   const noexcept;
-    iterator               end() noexcept;
-    const_iterator         end()     const noexcept;
-
-    reverse_iterator       rbegin() noexcept;
-    const_reverse_iterator rbegin()  const noexcept;
-    reverse_iterator       rend() noexcept;
-    const_reverse_iterator rend()    const noexcept;
-
-    const_iterator         cbegin()  const noexcept;
-    const_iterator         cend()    const noexcept;
-    const_reverse_iterator crbegin() const noexcept;
-    const_reverse_iterator crend()   const noexcept;
-
-    size_type size() const noexcept;
-    size_type max_size() const noexcept;
-    size_type capacity() const noexcept;
-    bool empty() const noexcept;
-    void reserve(size_type n);
-    void shrink_to_fit() noexcept;
-
-    reference       operator[](size_type n);
-    const_reference operator[](size_type n) const;
-    reference       at(size_type n);
-    const_reference at(size_type n) const;
-
-    reference       front();
-    const_reference front() const;
-    reference       back();
-    const_reference back() const;
-
-    void push_back(const value_type& x);
-    template <class... Args> reference emplace_back(Args&&... args);  // C++14; reference in C++17
-    void pop_back();
-
-    template <class... Args> iterator emplace(const_iterator position, Args&&... args);  // C++14
-    iterator insert(const_iterator position, const value_type& x);
-    iterator insert(const_iterator position, size_type n, const value_type& x);
-    template <class InputIterator>
-        iterator insert(const_iterator position, InputIterator first, InputIterator last);
-    iterator insert(const_iterator position, initializer_list<value_type> il);
-
-    iterator erase(const_iterator position);
-    iterator erase(const_iterator first, const_iterator last);
-
-    void clear() noexcept;
-
-    void resize(size_type sz);
-    void resize(size_type sz, value_type x);
-
-    void swap(vector&)
-        noexcept(allocator_traits<allocator_type>::propagate_on_container_swap::value ||
-                 allocator_traits<allocator_type>::is_always_equal::value);  // C++17
-    void flip() noexcept;
-
-    bool __invariants() const;
-};
-
-template <class InputIterator, class Allocator = allocator<typename iterator_traits<InputIterator>::value_type>>
-   vector(InputIterator, InputIterator, Allocator = Allocator())
-   -> vector<typename iterator_traits<InputIterator>::value_type, Allocator>;
-
-template <class Allocator> struct hash<std::vector<bool, Allocator>>;
-
-template <class T, class Allocator> bool operator==(const vector<T,Allocator>& x, const vector<T,Allocator>& y);
-template <class T, class Allocator> bool operator< (const vector<T,Allocator>& x, const vector<T,Allocator>& y);
-template <class T, class Allocator> bool operator!=(const vector<T,Allocator>& x, const vector<T,Allocator>& y);
-template <class T, class Allocator> bool operator> (const vector<T,Allocator>& x, const vector<T,Allocator>& y);
-template <class T, class Allocator> bool operator>=(const vector<T,Allocator>& x, const vector<T,Allocator>& y);
-template <class T, class Allocator> bool operator<=(const vector<T,Allocator>& x, const vector<T,Allocator>& y);
-
-template <class T, class Allocator>
-void swap(vector<T,Allocator>& x, vector<T,Allocator>& y)
-    noexcept(noexcept(x.swap(y)));
-
-template <class T, class Allocator, class U>
-    void erase(vector<T, Allocator>& c, const U& value);       // C++20
-template <class T, class Allocator, class Predicate>
-    void erase_if(vector<T, Allocator>& c, Predicate pred);    // C++20
-
-}  // std
-
-*/
-
-#include <__config>
-#include <iosfwd> // for forward declaration of vector
-#include <__bit_reference>
-#include <type_traits>
-#include <climits>
-#include <limits>
-#include <initializer_list>
-#include <memory>
-#include <stdexcept>
-#include <algorithm>
-#include <cstring>
-#include <version>
-#include <__split_buffer>
-#include <__functional_base>
-
-#include <__debug>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-_LIBCPP_PUSH_MACROS
-#include <__undef_macros>
-
-
-_LIBCPP_BEGIN_NAMESPACE_STD
-
-template <bool>
-class __vector_base_common
-{
-protected:
-    _LIBCPP_INLINE_VISIBILITY __vector_base_common() {}
-    _LIBCPP_NORETURN void __throw_length_error() const;
-    _LIBCPP_NORETURN void __throw_out_of_range() const;
-};
-
-template <bool __b>
-void
-__vector_base_common<__b>::__throw_length_error() const
-{
-    _VSTD::__throw_length_error("vector");
-}
-
-template <bool __b>
-void
-__vector_base_common<__b>::__throw_out_of_range() const
-{
-    _VSTD::__throw_out_of_range("vector");
-}
-
-_LIBCPP_EXTERN_TEMPLATE(class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS __vector_base_common<true>)
-
-template <class _Tp, class _Allocator>
-class __vector_base
-    : protected __vector_base_common<true>
-{
-public:
-    typedef _Allocator                               allocator_type;
-    typedef allocator_traits<allocator_type>         __alloc_traits;
-    typedef typename __alloc_traits::size_type       size_type;
-protected:
-    typedef _Tp                                      value_type;
-    typedef value_type&                              reference;
-    typedef const value_type&                        const_reference;
-    typedef typename __alloc_traits::difference_type difference_type;
-    typedef typename __alloc_traits::pointer         pointer;
-    typedef typename __alloc_traits::const_pointer   const_pointer;
-    typedef pointer                                  iterator;
-    typedef const_pointer                            const_iterator;
-
-    pointer                                         __begin_;
-    pointer                                         __end_;
-    __compressed_pair<pointer, allocator_type> __end_cap_;
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type& __alloc() _NOEXCEPT
-        {return __end_cap_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const allocator_type& __alloc() const _NOEXCEPT
-        {return __end_cap_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    pointer& __end_cap() _NOEXCEPT
-        {return __end_cap_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-    const pointer& __end_cap() const _NOEXCEPT
-        {return __end_cap_.first();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    __vector_base()
-        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
-    _LIBCPP_INLINE_VISIBILITY __vector_base(const allocator_type& __a);
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY __vector_base(allocator_type&& __a) _NOEXCEPT;
-#endif
-    ~__vector_base();
-
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {__destruct_at_end(__begin_);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type capacity() const _NOEXCEPT
-        {return static_cast<size_type>(__end_cap() - __begin_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __destruct_at_end(pointer __new_last) _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __vector_base& __c)
-        {__copy_assign_alloc(__c, integral_constant<bool,
-                      __alloc_traits::propagate_on_container_copy_assignment::value>());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__vector_base& __c)
-        _NOEXCEPT_(
-            !__alloc_traits::propagate_on_container_move_assignment::value ||
-            is_nothrow_move_assignable<allocator_type>::value)
-        {__move_assign_alloc(__c, integral_constant<bool,
-                      __alloc_traits::propagate_on_container_move_assignment::value>());}
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __vector_base& __c, true_type)
-        {
-            if (__alloc() != __c.__alloc())
-            {
-                clear();
-                __alloc_traits::deallocate(__alloc(), __begin_, capacity());
-                __begin_ = __end_ = __end_cap() = nullptr;
-            }
-            __alloc() = __c.__alloc();
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const __vector_base&, false_type)
-        {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__vector_base& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-        {
-            __alloc() = _VSTD::move(__c.__alloc());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(__vector_base&, false_type)
-        _NOEXCEPT
-        {}
-};
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-__vector_base<_Tp, _Allocator>::__destruct_at_end(pointer __new_last) _NOEXCEPT
-{
-    pointer __soon_to_be_end = __end_;
-    while (__new_last != __soon_to_be_end)
-        __alloc_traits::destroy(__alloc(), _VSTD::__to_raw_pointer(--__soon_to_be_end));
-    __end_ = __new_last;
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-__vector_base<_Tp, _Allocator>::__vector_base()
-        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
-    : __begin_(nullptr),
-      __end_(nullptr),
-      __end_cap_(nullptr)
-{
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-__vector_base<_Tp, _Allocator>::__vector_base(const allocator_type& __a)
-    : __begin_(nullptr),
-      __end_(nullptr),
-      __end_cap_(nullptr, __a)
-{
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-__vector_base<_Tp, _Allocator>::__vector_base(allocator_type&& __a) _NOEXCEPT
-    : __begin_(nullptr),
-      __end_(nullptr),
-      __end_cap_(nullptr, std::move(__a)) {}
-#endif
-
-template <class _Tp, class _Allocator>
-__vector_base<_Tp, _Allocator>::~__vector_base()
-{
-    if (__begin_ != nullptr)
-    {
-        clear();
-        __alloc_traits::deallocate(__alloc(), __begin_, capacity());
-    }
-}
-
-template <class _Tp, class _Allocator /* = allocator<_Tp> */>
-class _LIBCPP_TEMPLATE_VIS vector
-    : private __vector_base<_Tp, _Allocator>
-{
-private:
-    typedef __vector_base<_Tp, _Allocator>           __base;
-    typedef allocator<_Tp>                           __default_allocator_type;
-public:
-    typedef vector                                   __self;
-    typedef _Tp                                      value_type;
-    typedef _Allocator                               allocator_type;
-    typedef typename __base::__alloc_traits          __alloc_traits;
-    typedef typename __base::reference               reference;
-    typedef typename __base::const_reference         const_reference;
-    typedef typename __base::size_type               size_type;
-    typedef typename __base::difference_type         difference_type;
-    typedef typename __base::pointer                 pointer;
-    typedef typename __base::const_pointer           const_pointer;
-    typedef __wrap_iter<pointer>                     iterator;
-    typedef __wrap_iter<const_pointer>               const_iterator;
-    typedef _VSTD::reverse_iterator<iterator>         reverse_iterator;
-    typedef _VSTD::reverse_iterator<const_iterator>   const_reverse_iterator;
-
-    static_assert((is_same<typename allocator_type::value_type, value_type>::value),
-                  "Allocator::value_type must be same type as value_type");
-
-    _LIBCPP_INLINE_VISIBILITY
-    vector() _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
-        {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-            __get_db()->__insert_c(this);
-#endif
-        }
-    _LIBCPP_INLINE_VISIBILITY explicit vector(const allocator_type& __a)
-#if _LIBCPP_STD_VER <= 14
-        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
-#else
-        _NOEXCEPT
-#endif
-        : __base(__a)
-    {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->__insert_c(this);
-#endif
-    }
-    explicit vector(size_type __n);
-#if _LIBCPP_STD_VER > 11
-    explicit vector(size_type __n, const allocator_type& __a);
-#endif
-    vector(size_type __n, const value_type& __x);
-    vector(size_type __n, const value_type& __x, const allocator_type& __a);
-    template <class _InputIterator>
-        vector(_InputIterator __first,
-               typename enable_if<__is_input_iterator  <_InputIterator>::value &&
-                                 !__is_forward_iterator<_InputIterator>::value &&
-                                 is_constructible<
-                                    value_type,
-                                    typename iterator_traits<_InputIterator>::reference>::value,
-                                 _InputIterator>::type __last);
-    template <class _InputIterator>
-        vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a,
-               typename enable_if<__is_input_iterator  <_InputIterator>::value &&
-                                 !__is_forward_iterator<_InputIterator>::value &&
-                                 is_constructible<
-                                    value_type,
-                                    typename iterator_traits<_InputIterator>::reference>::value>::type* = 0);
-    template <class _ForwardIterator>
-        vector(_ForwardIterator __first,
-               typename enable_if<__is_forward_iterator<_ForwardIterator>::value &&
-                                 is_constructible<
-                                    value_type,
-                                    typename iterator_traits<_ForwardIterator>::reference>::value,
-                                 _ForwardIterator>::type __last);
-    template <class _ForwardIterator>
-        vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a,
-               typename enable_if<__is_forward_iterator<_ForwardIterator>::value &&
-                                 is_constructible<
-                                    value_type,
-                                    typename iterator_traits<_ForwardIterator>::reference>::value>::type* = 0);
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~vector()
-    {
-        __annotate_delete();
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->__erase_c(this);
-#endif
-    }
-
-    vector(const vector& __x);
-    vector(const vector& __x, const allocator_type& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    vector& operator=(const vector& __x);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    vector(initializer_list<value_type> __il);
-
-    _LIBCPP_INLINE_VISIBILITY
-    vector(initializer_list<value_type> __il, const allocator_type& __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    vector(vector&& __x)
-#if _LIBCPP_STD_VER > 14
-        _NOEXCEPT;
-#else
-        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    vector(vector&& __x, const allocator_type& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    vector& operator=(vector&& __x)
-        _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
-
-    _LIBCPP_INLINE_VISIBILITY
-    vector& operator=(initializer_list<value_type> __il)
-        {assign(__il.begin(), __il.end()); return *this;}
-
-#endif  // !_LIBCPP_CXX03_LANG
-
-    template <class _InputIterator>
-        typename enable_if
-        <
-             __is_input_iterator  <_InputIterator>::value &&
-            !__is_forward_iterator<_InputIterator>::value &&
-            is_constructible<
-                 value_type,
-                 typename iterator_traits<_InputIterator>::reference>::value,
-            void
-        >::type
-        assign(_InputIterator __first, _InputIterator __last);
-    template <class _ForwardIterator>
-        typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value &&
-            is_constructible<
-                 value_type,
-                 typename iterator_traits<_ForwardIterator>::reference>::value,
-            void
-        >::type
-        assign(_ForwardIterator __first, _ForwardIterator __last);
-
-    void assign(size_type __n, const_reference __u);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void assign(initializer_list<value_type> __il)
-        {assign(__il.begin(), __il.end());}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY
-    allocator_type get_allocator() const _NOEXCEPT
-        {return this->__alloc();}
-
-    _LIBCPP_INLINE_VISIBILITY iterator               begin() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY const_iterator         begin()   const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY iterator               end() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY const_iterator         end()     const _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator       rbegin() _NOEXCEPT
-        {return       reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin()  const _NOEXCEPT
-        {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator       rend() _NOEXCEPT
-        {return       reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend()    const _NOEXCEPT
-        {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator         cbegin()  const _NOEXCEPT
-        {return begin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator         cend()    const _NOEXCEPT
-        {return end();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT
-        {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend()   const _NOEXCEPT
-        {return rend();}
-
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT
-        {return static_cast<size_type>(this->__end_ - this->__begin_);}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type capacity() const _NOEXCEPT
-        {return __base::capacity();}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT
-        {return this->__begin_ == this->__end_;}
-    size_type max_size() const _NOEXCEPT;
-    void reserve(size_type __n);
-    void shrink_to_fit() _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY reference       operator[](size_type __n);
-    _LIBCPP_INLINE_VISIBILITY const_reference operator[](size_type __n) const;
-    reference       at(size_type __n);
-    const_reference at(size_type __n) const;
-
-    _LIBCPP_INLINE_VISIBILITY reference       front()
-    {
-        _LIBCPP_ASSERT(!empty(), "front() called for empty vector");
-        return *this->__begin_;
-    }
-    _LIBCPP_INLINE_VISIBILITY const_reference front() const
-    {
-        _LIBCPP_ASSERT(!empty(), "front() called for empty vector");
-        return *this->__begin_;
-    }
-    _LIBCPP_INLINE_VISIBILITY reference       back()
-    {
-        _LIBCPP_ASSERT(!empty(), "back() called for empty vector");
-        return *(this->__end_ - 1);
-    }
-    _LIBCPP_INLINE_VISIBILITY const_reference back()  const
-    {
-        _LIBCPP_ASSERT(!empty(), "back() called for empty vector");
-        return *(this->__end_ - 1);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    value_type*       data() _NOEXCEPT
-        {return _VSTD::__to_raw_pointer(this->__begin_);}
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type* data() const _NOEXCEPT
-        {return _VSTD::__to_raw_pointer(this->__begin_);}
-
-#ifdef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void __emplace_back(const value_type& __x) { push_back(__x); }
-#else
-    template <class _Arg>
-    _LIBCPP_INLINE_VISIBILITY
-    void __emplace_back(_Arg&& __arg) {
-      emplace_back(_VSTD::forward<_Arg>(__arg));
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY void push_back(const_reference __x);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY void push_back(value_type&& __x);
-
-    template <class... _Args>
-        _LIBCPP_INLINE_VISIBILITY
-#if _LIBCPP_STD_VER > 14
-        reference emplace_back(_Args&&... __args);
-#else
-        void      emplace_back(_Args&&... __args);
-#endif
-#endif // !_LIBCPP_CXX03_LANG
-
-    _LIBCPP_INLINE_VISIBILITY
-    void pop_back();
-
-    iterator insert(const_iterator __position, const_reference __x);
-
-#ifndef _LIBCPP_CXX03_LANG
-    iterator insert(const_iterator __position, value_type&& __x);
-    template <class... _Args>
-        iterator emplace(const_iterator __position, _Args&&... __args);
-#endif  // !_LIBCPP_CXX03_LANG
-
-    iterator insert(const_iterator __position, size_type __n, const_reference __x);
-    template <class _InputIterator>
-        typename enable_if
-        <
-             __is_input_iterator  <_InputIterator>::value &&
-            !__is_forward_iterator<_InputIterator>::value &&
-            is_constructible<
-                 value_type,
-                 typename iterator_traits<_InputIterator>::reference>::value,
-            iterator
-        >::type
-        insert(const_iterator __position, _InputIterator __first, _InputIterator __last);
-    template <class _ForwardIterator>
-        typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value &&
-            is_constructible<
-                 value_type,
-                 typename iterator_traits<_ForwardIterator>::reference>::value,
-            iterator
-        >::type
-        insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __position, initializer_list<value_type> __il)
-        {return insert(__position, __il.begin(), __il.end());}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY iterator erase(const_iterator __position);
-    iterator erase(const_iterator __first, const_iterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT
-    {
-        size_type __old_size = size();
-        __base::clear();
-        __annotate_shrink(__old_size);
-        __invalidate_all_iterators();
-    }
-
-    void resize(size_type __sz);
-    void resize(size_type __sz, const_reference __x);
-
-    void swap(vector&)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT_DEBUG;
-#else
-        _NOEXCEPT_DEBUG_(!__alloc_traits::propagate_on_container_swap::value ||
-                    __is_nothrow_swappable<allocator_type>::value);
-#endif
-
-    bool __invariants() const;
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-    bool __dereferenceable(const const_iterator* __i) const;
-    bool __decrementable(const const_iterator* __i) const;
-    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
-    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-private:
-    _LIBCPP_INLINE_VISIBILITY void __invalidate_all_iterators();
-    _LIBCPP_INLINE_VISIBILITY void __invalidate_iterators_past(pointer __new_last);
-    void __vallocate(size_type __n);
-    void __vdeallocate() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY size_type __recommend(size_type __new_size) const;
-    void __construct_at_end(size_type __n);
-    _LIBCPP_INLINE_VISIBILITY
-    void __construct_at_end(size_type __n, const_reference __x);
-    template <class _ForwardIterator>
-        typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value,
-            void
-        >::type
-        __construct_at_end(_ForwardIterator __first, _ForwardIterator __last, size_type __n);
-    void __append(size_type __n);
-    void __append(size_type __n, const_reference __x);
-    _LIBCPP_INLINE_VISIBILITY
-    iterator       __make_iter(pointer __p) _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator __make_iter(const_pointer __p) const _NOEXCEPT;
-    void __swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v);
-    pointer __swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v, pointer __p);
-    void __move_range(pointer __from_s, pointer __from_e, pointer __to);
-    void __move_assign(vector& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
-    void __move_assign(vector& __c, false_type)
-        _NOEXCEPT_(__alloc_traits::is_always_equal::value);
-    _LIBCPP_INLINE_VISIBILITY
-    void __destruct_at_end(pointer __new_last) _NOEXCEPT
-    {
-        __invalidate_iterators_past(__new_last);
-        size_type __old_size = size();
-        __base::__destruct_at_end(__new_last);
-        __annotate_shrink(__old_size);
-    }
-
-#ifndef _LIBCPP_CXX03_LANG
-    template <class _Up> void __push_back_slow_path(_Up&& __x);
-
-    template <class... _Args>
-    void __emplace_back_slow_path(_Args&&... __args);
-#else
-    template <class _Up> void __push_back_slow_path(_Up& __x);
-#endif
-
-    // The following functions are no-ops outside of AddressSanitizer mode.
-    // We call annotatations only for the default Allocator because other allocators
-    // may not meet the AddressSanitizer alignment constraints.
-    // See the documentation for __sanitizer_annotate_contiguous_container for more details.
-#ifndef _LIBCPP_HAS_NO_ASAN
-    void __annotate_contiguous_container(const void *__beg, const void *__end,
-                                         const void *__old_mid,
-                                         const void *__new_mid) const
-    {
-
-      if (__beg && is_same<allocator_type, __default_allocator_type>::value)
-        __sanitizer_annotate_contiguous_container(__beg, __end, __old_mid, __new_mid);
-    }
-#else
-    _LIBCPP_INLINE_VISIBILITY
-    void __annotate_contiguous_container(const void*, const void*, const void*,
-                                         const void*) const {}
-#endif
-    _LIBCPP_INLINE_VISIBILITY
-    void __annotate_new(size_type __current_size) const {
-      __annotate_contiguous_container(data(), data() + capacity(),
-                                      data() + capacity(), data() + __current_size);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __annotate_delete() const {
-      __annotate_contiguous_container(data(), data() + capacity(),
-                                      data() + size(), data() + capacity());
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __annotate_increase(size_type __n) const
-    {
-      __annotate_contiguous_container(data(), data() + capacity(),
-                                      data() + size(), data() + size() + __n);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __annotate_shrink(size_type __old_size) const
-    {
-      __annotate_contiguous_container(data(), data() + capacity(),
-                                      data() + __old_size, data() + size());
-    }
-#ifndef _LIBCPP_HAS_NO_ASAN
-    // The annotation for size increase should happen before the actual increase,
-    // but if an exception is thrown after that the annotation has to be undone.
-    struct __RAII_IncreaseAnnotator {
-      __RAII_IncreaseAnnotator(const vector &__v, size_type __n = 1)
-        : __commit(false), __v(__v), __old_size(__v.size() + __n) {
-        __v.__annotate_increase(__n);
-      }
-      void __done() { __commit = true; }
-      ~__RAII_IncreaseAnnotator() {
-        if (__commit) return;
-        __v.__annotate_shrink(__old_size);
-      }
-      bool __commit;
-      const vector &__v;
-      size_type __old_size;
-    };
-#else
-    struct __RAII_IncreaseAnnotator {
-      _LIBCPP_INLINE_VISIBILITY
-      __RAII_IncreaseAnnotator(const vector &, size_type = 1) {}
-      _LIBCPP_INLINE_VISIBILITY void __done() {}
-    };
-#endif
-
-};
-
-#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
-template<class _InputIterator,
-         class _Alloc = typename std::allocator<typename iterator_traits<_InputIterator>::value_type>,
-         class = typename enable_if<__is_allocator<_Alloc>::value, void>::type
-         >
-vector(_InputIterator, _InputIterator)
-  -> vector<typename iterator_traits<_InputIterator>::value_type, _Alloc>;
-
-template<class _InputIterator,
-         class _Alloc,
-         class = typename enable_if<__is_allocator<_Alloc>::value, void>::type
-         >
-vector(_InputIterator, _InputIterator, _Alloc)
-  -> vector<typename iterator_traits<_InputIterator>::value_type, _Alloc>;
-#endif
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v)
-{
-    __annotate_delete();
-    __alloc_traits::__construct_backward(this->__alloc(), this->__begin_, this->__end_, __v.__begin_);
-    _VSTD::swap(this->__begin_, __v.__begin_);
-    _VSTD::swap(this->__end_, __v.__end_);
-    _VSTD::swap(this->__end_cap(), __v.__end_cap());
-    __v.__first_ = __v.__begin_;
-    __annotate_new(size());
-    __invalidate_all_iterators();
-}
-
-template <class _Tp, class _Allocator>
-typename vector<_Tp, _Allocator>::pointer
-vector<_Tp, _Allocator>::__swap_out_circular_buffer(__split_buffer<value_type, allocator_type&>& __v, pointer __p)
-{
-    __annotate_delete();
-    pointer __r = __v.__begin_;
-    __alloc_traits::__construct_backward(this->__alloc(), this->__begin_, __p, __v.__begin_);
-    __alloc_traits::__construct_forward(this->__alloc(), __p, this->__end_, __v.__end_);
-    _VSTD::swap(this->__begin_, __v.__begin_);
-    _VSTD::swap(this->__end_, __v.__end_);
-    _VSTD::swap(this->__end_cap(), __v.__end_cap());
-    __v.__first_ = __v.__begin_;
-    __annotate_new(size());
-    __invalidate_all_iterators();
-    return __r;
-}
-
-//  Allocate space for __n objects
-//  throws length_error if __n > max_size()
-//  throws (probably bad_alloc) if memory run out
-//  Precondition:  __begin_ == __end_ == __end_cap() == 0
-//  Precondition:  __n > 0
-//  Postcondition:  capacity() == __n
-//  Postcondition:  size() == 0
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::__vallocate(size_type __n)
-{
-    if (__n > max_size())
-        this->__throw_length_error();
-    this->__begin_ = this->__end_ = __alloc_traits::allocate(this->__alloc(), __n);
-    this->__end_cap() = this->__begin_ + __n;
-    __annotate_new(0);
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::__vdeallocate() _NOEXCEPT
-{
-    if (this->__begin_ != nullptr)
-    {
-        clear();
-        __alloc_traits::deallocate(this->__alloc(), this->__begin_, capacity());
-        this->__begin_ = this->__end_ = this->__end_cap() = nullptr;
-    }
-}
-
-template <class _Tp, class _Allocator>
-typename vector<_Tp, _Allocator>::size_type
-vector<_Tp, _Allocator>::max_size() const _NOEXCEPT
-{
-    return _VSTD::min<size_type>(__alloc_traits::max_size(this->__alloc()),
-                                 numeric_limits<difference_type>::max());
-}
-
-//  Precondition:  __new_size > capacity()
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::size_type
-vector<_Tp, _Allocator>::__recommend(size_type __new_size) const
-{
-    const size_type __ms = max_size();
-    if (__new_size > __ms)
-        this->__throw_length_error();
-    const size_type __cap = capacity();
-    if (__cap >= __ms / 2)
-        return __ms;
-    return _VSTD::max<size_type>(2*__cap, __new_size);
-}
-
-//  Default constructs __n objects starting at __end_
-//  throws if construction throws
-//  Precondition:  __n > 0
-//  Precondition:  size() + __n <= capacity()
-//  Postcondition:  size() == size() + __n
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::__construct_at_end(size_type __n)
-{
-    allocator_type& __a = this->__alloc();
-    do
-    {
-        __RAII_IncreaseAnnotator __annotator(*this);
-        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_));
-        ++this->__end_;
-        --__n;
-        __annotator.__done();
-    } while (__n > 0);
-}
-
-//  Copy constructs __n objects starting at __end_ from __x
-//  throws if construction throws
-//  Precondition:  __n > 0
-//  Precondition:  size() + __n <= capacity()
-//  Postcondition:  size() == old size() + __n
-//  Postcondition:  [i] == __x for all i in [size() - __n, __n)
-template <class _Tp, class _Allocator>
-inline
-void
-vector<_Tp, _Allocator>::__construct_at_end(size_type __n, const_reference __x)
-{
-    allocator_type& __a = this->__alloc();
-    do
-    {
-        __RAII_IncreaseAnnotator __annotator(*this);
-        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_), __x);
-        ++this->__end_;
-        --__n;
-        __annotator.__done();
-    } while (__n > 0);
-}
-
-template <class _Tp, class _Allocator>
-template <class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value,
-    void
->::type
-vector<_Tp, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last, size_type __n)
-{
-    allocator_type& __a = this->__alloc();
-    __RAII_IncreaseAnnotator __annotator(*this, __n);
-    __alloc_traits::__construct_range_forward(__a, __first, __last, this->__end_);
-    __annotator.__done();
-}
-
-//  Default constructs __n objects starting at __end_
-//  throws if construction throws
-//  Postcondition:  size() == size() + __n
-//  Exception safety: strong.
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::__append(size_type __n)
-{
-    if (static_cast<size_type>(this->__end_cap() - this->__end_) >= __n)
-        this->__construct_at_end(__n);
-    else
-    {
-        allocator_type& __a = this->__alloc();
-        __split_buffer<value_type, allocator_type&> __v(__recommend(size() + __n), size(), __a);
-        __v.__construct_at_end(__n);
-        __swap_out_circular_buffer(__v);
-    }
-}
-
-//  Default constructs __n objects starting at __end_
-//  throws if construction throws
-//  Postcondition:  size() == size() + __n
-//  Exception safety: strong.
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::__append(size_type __n, const_reference __x)
-{
-    if (static_cast<size_type>(this->__end_cap() - this->__end_) >= __n)
-        this->__construct_at_end(__n, __x);
-    else
-    {
-        allocator_type& __a = this->__alloc();
-        __split_buffer<value_type, allocator_type&> __v(__recommend(size() + __n), size(), __a);
-        __v.__construct_at_end(__n, __x);
-        __swap_out_circular_buffer(__v);
-    }
-}
-
-template <class _Tp, class _Allocator>
-vector<_Tp, _Allocator>::vector(size_type __n)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__n);
-    }
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _Tp, class _Allocator>
-vector<_Tp, _Allocator>::vector(size_type __n, const allocator_type& __a)
-    : __base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__n);
-    }
-}
-#endif
-
-template <class _Tp, class _Allocator>
-vector<_Tp, _Allocator>::vector(size_type __n, const value_type& __x)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__n, __x);
-    }
-}
-
-template <class _Tp, class _Allocator>
-vector<_Tp, _Allocator>::vector(size_type __n, const value_type& __x, const allocator_type& __a)
-    : __base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__n, __x);
-    }
-}
-
-template <class _Tp, class _Allocator>
-template <class _InputIterator>
-vector<_Tp, _Allocator>::vector(_InputIterator __first,
-       typename enable_if<__is_input_iterator  <_InputIterator>::value &&
-                         !__is_forward_iterator<_InputIterator>::value &&
-                         is_constructible<
-                            value_type,
-                            typename iterator_traits<_InputIterator>::reference>::value,
-                          _InputIterator>::type __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (; __first != __last; ++__first)
-        __emplace_back(*__first);
-}
-
-template <class _Tp, class _Allocator>
-template <class _InputIterator>
-vector<_Tp, _Allocator>::vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a,
-       typename enable_if<__is_input_iterator  <_InputIterator>::value &&
-                         !__is_forward_iterator<_InputIterator>::value &&
-                         is_constructible<
-                            value_type,
-                            typename iterator_traits<_InputIterator>::reference>::value>::type*)
-    : __base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    for (; __first != __last; ++__first)
-        __emplace_back(*__first);
-}
-
-template <class _Tp, class _Allocator>
-template <class _ForwardIterator>
-vector<_Tp, _Allocator>::vector(_ForwardIterator __first,
-                                typename enable_if<__is_forward_iterator<_ForwardIterator>::value &&
-                                is_constructible<
-                                   value_type,
-                                   typename iterator_traits<_ForwardIterator>::reference>::value,
-                                                   _ForwardIterator>::type __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__first, __last, __n);
-    }
-}
-
-template <class _Tp, class _Allocator>
-template <class _ForwardIterator>
-vector<_Tp, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a,
-                                typename enable_if<__is_forward_iterator<_ForwardIterator>::value &&
-                                is_constructible<
-                                   value_type,
-                                   typename iterator_traits<_ForwardIterator>::reference>::value>::type*)
-    : __base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__first, __last, __n);
-    }
-}
-
-template <class _Tp, class _Allocator>
-vector<_Tp, _Allocator>::vector(const vector& __x)
-    : __base(__alloc_traits::select_on_container_copy_construction(__x.__alloc()))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    size_type __n = __x.size();
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__x.__begin_, __x.__end_, __n);
-    }
-}
-
-template <class _Tp, class _Allocator>
-vector<_Tp, _Allocator>::vector(const vector& __x, const allocator_type& __a)
-    : __base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    size_type __n = __x.size();
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__x.__begin_, __x.__end_, __n);
-    }
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-vector<_Tp, _Allocator>::vector(vector&& __x)
-#if _LIBCPP_STD_VER > 14
-        _NOEXCEPT
-#else
-        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
-#endif
-    : __base(_VSTD::move(__x.__alloc()))
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-    __get_db()->swap(this, &__x);
-#endif
-    this->__begin_ = __x.__begin_;
-    this->__end_ = __x.__end_;
-    this->__end_cap() = __x.__end_cap();
-    __x.__begin_ = __x.__end_ = __x.__end_cap() = nullptr;
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-vector<_Tp, _Allocator>::vector(vector&& __x, const allocator_type& __a)
-    : __base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__a == __x.__alloc())
-    {
-        this->__begin_ = __x.__begin_;
-        this->__end_ = __x.__end_;
-        this->__end_cap() = __x.__end_cap();
-        __x.__begin_ = __x.__end_ = __x.__end_cap() = nullptr;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-        __get_db()->swap(this, &__x);
-#endif
-    }
-    else
-    {
-        typedef move_iterator<iterator> _Ip;
-        assign(_Ip(__x.begin()), _Ip(__x.end()));
-    }
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-vector<_Tp, _Allocator>::vector(initializer_list<value_type> __il)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__il.size() > 0)
-    {
-        __vallocate(__il.size());
-        __construct_at_end(__il.begin(), __il.end(), __il.size());
-    }
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-vector<_Tp, _Allocator>::vector(initializer_list<value_type> __il, const allocator_type& __a)
-    : __base(__a)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__insert_c(this);
-#endif
-    if (__il.size() > 0)
-    {
-        __vallocate(__il.size());
-        __construct_at_end(__il.begin(), __il.end(), __il.size());
-    }
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-vector<_Tp, _Allocator>&
-vector<_Tp, _Allocator>::operator=(vector&& __x)
-    _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
-{
-    __move_assign(__x, integral_constant<bool,
-          __alloc_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::__move_assign(vector& __c, false_type)
-    _NOEXCEPT_(__alloc_traits::is_always_equal::value)
-{
-    if (__base::__alloc() != __c.__alloc())
-    {
-        typedef move_iterator<iterator> _Ip;
-        assign(_Ip(__c.begin()), _Ip(__c.end()));
-    }
-    else
-        __move_assign(__c, true_type());
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::__move_assign(vector& __c, true_type)
-    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-{
-    __vdeallocate();
-    __base::__move_assign_alloc(__c); // this can throw
-    this->__begin_ = __c.__begin_;
-    this->__end_ = __c.__end_;
-    this->__end_cap() = __c.__end_cap();
-    __c.__begin_ = __c.__end_ = __c.__end_cap() = nullptr;
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->swap(this, &__c);
-#endif
-}
-
-#endif  // !_LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-vector<_Tp, _Allocator>&
-vector<_Tp, _Allocator>::operator=(const vector& __x)
-{
-    if (this != &__x)
-    {
-        __base::__copy_assign_alloc(__x);
-        assign(__x.__begin_, __x.__end_);
-    }
-    return *this;
-}
-
-template <class _Tp, class _Allocator>
-template <class _InputIterator>
-typename enable_if
-<
-     __is_input_iterator  <_InputIterator>::value &&
-    !__is_forward_iterator<_InputIterator>::value &&
-    is_constructible<
-       _Tp,
-       typename iterator_traits<_InputIterator>::reference>::value,
-    void
->::type
-vector<_Tp, _Allocator>::assign(_InputIterator __first, _InputIterator __last)
-{
-    clear();
-    for (; __first != __last; ++__first)
-        __emplace_back(*__first);
-}
-
-template <class _Tp, class _Allocator>
-template <class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value &&
-    is_constructible<
-       _Tp,
-       typename iterator_traits<_ForwardIterator>::reference>::value,
-    void
->::type
-vector<_Tp, _Allocator>::assign(_ForwardIterator __first, _ForwardIterator __last)
-{
-    size_type __new_size = static_cast<size_type>(_VSTD::distance(__first, __last));
-    if (__new_size <= capacity())
-    {
-        _ForwardIterator __mid = __last;
-        bool __growing = false;
-        if (__new_size > size())
-        {
-            __growing = true;
-            __mid =  __first;
-            _VSTD::advance(__mid, size());
-        }
-        pointer __m = _VSTD::copy(__first, __mid, this->__begin_);
-        if (__growing)
-            __construct_at_end(__mid, __last, __new_size - size());
-        else
-            this->__destruct_at_end(__m);
-    }
-    else
-    {
-        __vdeallocate();
-        __vallocate(__recommend(__new_size));
-        __construct_at_end(__first, __last, __new_size);
-    }
-    __invalidate_all_iterators();
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::assign(size_type __n, const_reference __u)
-{
-    if (__n <= capacity())
-    {
-        size_type __s = size();
-        _VSTD::fill_n(this->__begin_, _VSTD::min(__n, __s), __u);
-        if (__n > __s)
-            __construct_at_end(__n - __s, __u);
-        else
-            this->__destruct_at_end(this->__begin_ + __n);
-    }
-    else
-    {
-        __vdeallocate();
-        __vallocate(__recommend(static_cast<size_type>(__n)));
-        __construct_at_end(__n, __u);
-    }
-    __invalidate_all_iterators();
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::iterator
-vector<_Tp, _Allocator>::__make_iter(pointer __p) _NOEXCEPT
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return iterator(this, __p);
-#else
-    return iterator(__p);
-#endif
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::const_iterator
-vector<_Tp, _Allocator>::__make_iter(const_pointer __p) const _NOEXCEPT
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    return const_iterator(this, __p);
-#else
-    return const_iterator(__p);
-#endif
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::iterator
-vector<_Tp, _Allocator>::begin() _NOEXCEPT
-{
-    return __make_iter(this->__begin_);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::const_iterator
-vector<_Tp, _Allocator>::begin() const _NOEXCEPT
-{
-    return __make_iter(this->__begin_);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::iterator
-vector<_Tp, _Allocator>::end() _NOEXCEPT
-{
-    return __make_iter(this->__end_);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::const_iterator
-vector<_Tp, _Allocator>::end() const _NOEXCEPT
-{
-    return __make_iter(this->__end_);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::reference
-vector<_Tp, _Allocator>::operator[](size_type __n)
-{
-    _LIBCPP_ASSERT(__n < size(), "vector[] index out of bounds");
-    return this->__begin_[__n];
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::const_reference
-vector<_Tp, _Allocator>::operator[](size_type __n) const
-{
-    _LIBCPP_ASSERT(__n < size(), "vector[] index out of bounds");
-    return this->__begin_[__n];
-}
-
-template <class _Tp, class _Allocator>
-typename vector<_Tp, _Allocator>::reference
-vector<_Tp, _Allocator>::at(size_type __n)
-{
-    if (__n >= size())
-        this->__throw_out_of_range();
-    return this->__begin_[__n];
-}
-
-template <class _Tp, class _Allocator>
-typename vector<_Tp, _Allocator>::const_reference
-vector<_Tp, _Allocator>::at(size_type __n) const
-{
-    if (__n >= size())
-        this->__throw_out_of_range();
-    return this->__begin_[__n];
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::reserve(size_type __n)
-{
-    if (__n > capacity())
-    {
-        allocator_type& __a = this->__alloc();
-        __split_buffer<value_type, allocator_type&> __v(__n, size(), __a);
-        __swap_out_circular_buffer(__v);
-    }
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::shrink_to_fit() _NOEXCEPT
-{
-    if (capacity() > size())
-    {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            allocator_type& __a = this->__alloc();
-            __split_buffer<value_type, allocator_type&> __v(size(), size(), __a);
-            __swap_out_circular_buffer(__v);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template <class _Tp, class _Allocator>
-template <class _Up>
-void
-#ifndef _LIBCPP_CXX03_LANG
-vector<_Tp, _Allocator>::__push_back_slow_path(_Up&& __x)
-#else
-vector<_Tp, _Allocator>::__push_back_slow_path(_Up& __x)
-#endif
-{
-    allocator_type& __a = this->__alloc();
-    __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), size(), __a);
-    // __v.push_back(_VSTD::forward<_Up>(__x));
-    __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(__v.__end_), _VSTD::forward<_Up>(__x));
-    __v.__end_++;
-    __swap_out_circular_buffer(__v);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-vector<_Tp, _Allocator>::push_back(const_reference __x)
-{
-    if (this->__end_ != this->__end_cap())
-    {
-        __RAII_IncreaseAnnotator __annotator(*this);
-        __alloc_traits::construct(this->__alloc(),
-                                  _VSTD::__to_raw_pointer(this->__end_), __x);
-        __annotator.__done();
-        ++this->__end_;
-    }
-    else
-        __push_back_slow_path(__x);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-vector<_Tp, _Allocator>::push_back(value_type&& __x)
-{
-    if (this->__end_ < this->__end_cap())
-    {
-        __RAII_IncreaseAnnotator __annotator(*this);
-        __alloc_traits::construct(this->__alloc(),
-                                  _VSTD::__to_raw_pointer(this->__end_),
-                                  _VSTD::move(__x));
-        __annotator.__done();
-        ++this->__end_;
-    }
-    else
-        __push_back_slow_path(_VSTD::move(__x));
-}
-
-template <class _Tp, class _Allocator>
-template <class... _Args>
-void
-vector<_Tp, _Allocator>::__emplace_back_slow_path(_Args&&... __args)
-{
-    allocator_type& __a = this->__alloc();
-    __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), size(), __a);
-//    __v.emplace_back(_VSTD::forward<_Args>(__args)...);
-    __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(__v.__end_), _VSTD::forward<_Args>(__args)...);
-    __v.__end_++;
-    __swap_out_circular_buffer(__v);
-}
-
-template <class _Tp, class _Allocator>
-template <class... _Args>
-inline
-#if _LIBCPP_STD_VER > 14
-typename vector<_Tp, _Allocator>::reference
-#else
-void
-#endif
-vector<_Tp, _Allocator>::emplace_back(_Args&&... __args)
-{
-    if (this->__end_ < this->__end_cap())
-    {
-        __RAII_IncreaseAnnotator __annotator(*this);
-        __alloc_traits::construct(this->__alloc(),
-                                  _VSTD::__to_raw_pointer(this->__end_),
-                                  _VSTD::forward<_Args>(__args)...);
-        __annotator.__done();
-        ++this->__end_;
-    }
-    else
-        __emplace_back_slow_path(_VSTD::forward<_Args>(__args)...);
-#if _LIBCPP_STD_VER > 14
-    return this->back();
-#endif
-}
-
-#endif  // !_LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-inline
-void
-vector<_Tp, _Allocator>::pop_back()
-{
-    _LIBCPP_ASSERT(!empty(), "vector::pop_back called for empty vector");
-    this->__destruct_at_end(this->__end_ - 1);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<_Tp, _Allocator>::iterator
-vector<_Tp, _Allocator>::erase(const_iterator __position)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__position) == this,
-        "vector::erase(iterator) called with an iterator not"
-        " referring to this vector");
-#endif
-    _LIBCPP_ASSERT(__position != end(),
-        "vector::erase(iterator) called with a non-dereferenceable iterator");
-    difference_type __ps = __position - cbegin();
-    pointer __p = this->__begin_ + __ps;
-    this->__destruct_at_end(_VSTD::move(__p + 1, this->__end_, __p));
-    this->__invalidate_iterators_past(__p-1);
-    iterator __r = __make_iter(__p);
-    return __r;
-}
-
-template <class _Tp, class _Allocator>
-typename vector<_Tp, _Allocator>::iterator
-vector<_Tp, _Allocator>::erase(const_iterator __first, const_iterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
-        "vector::erase(iterator,  iterator) called with an iterator not"
-        " referring to this vector");
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__last) == this,
-        "vector::erase(iterator,  iterator) called with an iterator not"
-        " referring to this vector");
-#endif
-    _LIBCPP_ASSERT(__first <= __last, "vector::erase(first, last) called with invalid range");
-    pointer __p = this->__begin_ + (__first - begin());
-    if (__first != __last) {
-        this->__destruct_at_end(_VSTD::move(__p + (__last - __first), this->__end_, __p));
-        this->__invalidate_iterators_past(__p - 1);
-    }
-    iterator __r = __make_iter(__p);
-    return __r;
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::__move_range(pointer __from_s, pointer __from_e, pointer __to)
-{
-    pointer __old_last = this->__end_;
-    difference_type __n = __old_last - __to;
-    for (pointer __i = __from_s + __n; __i < __from_e; ++__i, ++this->__end_)
-        __alloc_traits::construct(this->__alloc(),
-                                  _VSTD::__to_raw_pointer(this->__end_),
-                                  _VSTD::move(*__i));
-    _VSTD::move_backward(__from_s, __from_s + __n, __old_last);
-}
-
-template <class _Tp, class _Allocator>
-typename vector<_Tp, _Allocator>::iterator
-vector<_Tp, _Allocator>::insert(const_iterator __position, const_reference __x)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__position) == this,
-        "vector::insert(iterator, x) called with an iterator not"
-        " referring to this vector");
-#endif
-    pointer __p = this->__begin_ + (__position - begin());
-    if (this->__end_ < this->__end_cap())
-    {
-        __RAII_IncreaseAnnotator __annotator(*this);
-        if (__p == this->__end_)
-        {
-            __alloc_traits::construct(this->__alloc(),
-                                      _VSTD::__to_raw_pointer(this->__end_), __x);
-            ++this->__end_;
-        }
-        else
-        {
-            __move_range(__p, this->__end_, __p + 1);
-            const_pointer __xr = pointer_traits<const_pointer>::pointer_to(__x);
-            if (__p <= __xr && __xr < this->__end_)
-                ++__xr;
-            *__p = *__xr;
-        }
-        __annotator.__done();
-    }
-    else
-    {
-        allocator_type& __a = this->__alloc();
-        __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), __p - this->__begin_, __a);
-        __v.push_back(__x);
-        __p = __swap_out_circular_buffer(__v, __p);
-    }
-    return __make_iter(__p);
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-typename vector<_Tp, _Allocator>::iterator
-vector<_Tp, _Allocator>::insert(const_iterator __position, value_type&& __x)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__position) == this,
-        "vector::insert(iterator, x) called with an iterator not"
-        " referring to this vector");
-#endif
-    pointer __p = this->__begin_ + (__position - begin());
-    if (this->__end_ < this->__end_cap())
-    {
-        __RAII_IncreaseAnnotator __annotator(*this);
-        if (__p == this->__end_)
-        {
-            __alloc_traits::construct(this->__alloc(),
-                                      _VSTD::__to_raw_pointer(this->__end_),
-                                      _VSTD::move(__x));
-            ++this->__end_;
-        }
-        else
-        {
-            __move_range(__p, this->__end_, __p + 1);
-            *__p = _VSTD::move(__x);
-        }
-        __annotator.__done();
-    }
-    else
-    {
-        allocator_type& __a = this->__alloc();
-        __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), __p - this->__begin_, __a);
-        __v.push_back(_VSTD::move(__x));
-        __p = __swap_out_circular_buffer(__v, __p);
-    }
-    return __make_iter(__p);
-}
-
-template <class _Tp, class _Allocator>
-template <class... _Args>
-typename vector<_Tp, _Allocator>::iterator
-vector<_Tp, _Allocator>::emplace(const_iterator __position, _Args&&... __args)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__position) == this,
-        "vector::emplace(iterator, x) called with an iterator not"
-        " referring to this vector");
-#endif
-    pointer __p = this->__begin_ + (__position - begin());
-    if (this->__end_ < this->__end_cap())
-    {
-        __RAII_IncreaseAnnotator __annotator(*this);
-        if (__p == this->__end_)
-        {
-            __alloc_traits::construct(this->__alloc(),
-                                      _VSTD::__to_raw_pointer(this->__end_),
-                                      _VSTD::forward<_Args>(__args)...);
-            ++this->__end_;
-        }
-        else
-        {
-            __temp_value<value_type, _Allocator> __tmp(this->__alloc(), _VSTD::forward<_Args>(__args)...);
-            __move_range(__p, this->__end_, __p + 1);
-            *__p = _VSTD::move(__tmp.get());
-        }
-        __annotator.__done();
-    }
-    else
-    {
-        allocator_type& __a = this->__alloc();
-        __split_buffer<value_type, allocator_type&> __v(__recommend(size() + 1), __p - this->__begin_, __a);
-        __v.emplace_back(_VSTD::forward<_Args>(__args)...);
-        __p = __swap_out_circular_buffer(__v, __p);
-    }
-    return __make_iter(__p);
-}
-
-#endif  // !_LIBCPP_CXX03_LANG
-
-template <class _Tp, class _Allocator>
-typename vector<_Tp, _Allocator>::iterator
-vector<_Tp, _Allocator>::insert(const_iterator __position, size_type __n, const_reference __x)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__position) == this,
-        "vector::insert(iterator, n, x) called with an iterator not"
-        " referring to this vector");
-#endif
-    pointer __p = this->__begin_ + (__position - begin());
-    if (__n > 0)
-    {
-        if (__n <= static_cast<size_type>(this->__end_cap() - this->__end_))
-        {
-            size_type __old_n = __n;
-            pointer __old_last = this->__end_;
-            if (__n > static_cast<size_type>(this->__end_ - __p))
-            {
-                size_type __cx = __n - (this->__end_ - __p);
-                __construct_at_end(__cx, __x);
-                __n -= __cx;
-            }
-            if (__n > 0)
-            {
-                __RAII_IncreaseAnnotator __annotator(*this, __n);
-                __move_range(__p, __old_last, __p + __old_n);
-                __annotator.__done();
-                const_pointer __xr = pointer_traits<const_pointer>::pointer_to(__x);
-                if (__p <= __xr && __xr < this->__end_)
-                    __xr += __old_n;
-                _VSTD::fill_n(__p, __n, *__xr);
-            }
-        }
-        else
-        {
-            allocator_type& __a = this->__alloc();
-            __split_buffer<value_type, allocator_type&> __v(__recommend(size() + __n), __p - this->__begin_, __a);
-            __v.__construct_at_end(__n, __x);
-            __p = __swap_out_circular_buffer(__v, __p);
-        }
-    }
-    return __make_iter(__p);
-}
-
-template <class _Tp, class _Allocator>
-template <class _InputIterator>
-typename enable_if
-<
-     __is_input_iterator  <_InputIterator>::value &&
-    !__is_forward_iterator<_InputIterator>::value &&
-    is_constructible<
-       _Tp,
-       typename iterator_traits<_InputIterator>::reference>::value,
-    typename vector<_Tp, _Allocator>::iterator
->::type
-vector<_Tp, _Allocator>::insert(const_iterator __position, _InputIterator __first, _InputIterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__position) == this,
-        "vector::insert(iterator, range) called with an iterator not"
-        " referring to this vector");
-#endif
-    difference_type __off = __position - begin();
-    pointer __p = this->__begin_ + __off;
-    allocator_type& __a = this->__alloc();
-    pointer __old_last = this->__end_;
-    for (; this->__end_ != this->__end_cap() && __first != __last; ++__first)
-    {
-        __RAII_IncreaseAnnotator __annotator(*this);
-        __alloc_traits::construct(__a, _VSTD::__to_raw_pointer(this->__end_),
-                                  *__first);
-        ++this->__end_;
-        __annotator.__done();
-    }
-    __split_buffer<value_type, allocator_type&> __v(__a);
-    if (__first != __last)
-    {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            __v.__construct_at_end(__first, __last);
-            difference_type __old_size = __old_last - this->__begin_;
-            difference_type __old_p = __p - this->__begin_;
-            reserve(__recommend(size() + __v.size()));
-            __p = this->__begin_ + __old_p;
-            __old_last = this->__begin_ + __old_size;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            erase(__make_iter(__old_last), end());
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-    __p = _VSTD::rotate(__p, __old_last, this->__end_);
-    insert(__make_iter(__p), make_move_iterator(__v.begin()),
-                                    make_move_iterator(__v.end()));
-    return begin() + __off;
-}
-
-template <class _Tp, class _Allocator>
-template <class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value &&
-    is_constructible<
-       _Tp,
-       typename iterator_traits<_ForwardIterator>::reference>::value,
-    typename vector<_Tp, _Allocator>::iterator
->::type
-vector<_Tp, _Allocator>::insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last)
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__position) == this,
-        "vector::insert(iterator, range) called with an iterator not"
-        " referring to this vector");
-#endif
-    pointer __p = this->__begin_ + (__position - begin());
-    difference_type __n = _VSTD::distance(__first, __last);
-    if (__n > 0)
-    {
-        if (__n <= this->__end_cap() - this->__end_)
-        {
-            size_type __old_n = __n;
-            pointer __old_last = this->__end_;
-            _ForwardIterator __m = __last;
-            difference_type __dx = this->__end_ - __p;
-            if (__n > __dx)
-            {
-                __m = __first;
-                difference_type __diff = this->__end_ - __p;
-                _VSTD::advance(__m, __diff);
-                __construct_at_end(__m, __last, __n - __diff);
-                __n = __dx;
-            }
-            if (__n > 0)
-            {
-                __RAII_IncreaseAnnotator __annotator(*this, __n);
-                __move_range(__p, __old_last, __p + __old_n);
-                __annotator.__done();
-                _VSTD::copy(__first, __m, __p);
-            }
-        }
-        else
-        {
-            allocator_type& __a = this->__alloc();
-            __split_buffer<value_type, allocator_type&> __v(__recommend(size() + __n), __p - this->__begin_, __a);
-            __v.__construct_at_end(__first, __last);
-            __p = __swap_out_circular_buffer(__v, __p);
-        }
-    }
-    return __make_iter(__p);
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::resize(size_type __sz)
-{
-    size_type __cs = size();
-    if (__cs < __sz)
-        this->__append(__sz - __cs);
-    else if (__cs > __sz)
-        this->__destruct_at_end(this->__begin_ + __sz);
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::resize(size_type __sz, const_reference __x)
-{
-    size_type __cs = size();
-    if (__cs < __sz)
-        this->__append(__sz - __cs, __x);
-    else if (__cs > __sz)
-        this->__destruct_at_end(this->__begin_ + __sz);
-}
-
-template <class _Tp, class _Allocator>
-void
-vector<_Tp, _Allocator>::swap(vector& __x)
-#if _LIBCPP_STD_VER >= 14
-    _NOEXCEPT_DEBUG
-#else
-    _NOEXCEPT_DEBUG_(!__alloc_traits::propagate_on_container_swap::value ||
-                __is_nothrow_swappable<allocator_type>::value)
-#endif
-{
-    _LIBCPP_ASSERT(__alloc_traits::propagate_on_container_swap::value ||
-                   this->__alloc() == __x.__alloc(),
-                   "vector::swap: Either propagate_on_container_swap must be true"
-                   " or the allocators must compare equal");
-    _VSTD::swap(this->__begin_, __x.__begin_);
-    _VSTD::swap(this->__end_, __x.__end_);
-    _VSTD::swap(this->__end_cap(), __x.__end_cap());
-    __swap_allocator(this->__alloc(), __x.__alloc(),
-        integral_constant<bool,__alloc_traits::propagate_on_container_swap::value>());
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->swap(this, &__x);
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-}
-
-template <class _Tp, class _Allocator>
-bool
-vector<_Tp, _Allocator>::__invariants() const
-{
-    if (this->__begin_ == nullptr)
-    {
-        if (this->__end_ != nullptr || this->__end_cap() != nullptr)
-            return false;
-    }
-    else
-    {
-        if (this->__begin_ > this->__end_)
-            return false;
-        if (this->__begin_ == this->__end_cap())
-            return false;
-        if (this->__end_ > this->__end_cap())
-            return false;
-    }
-    return true;
-}
-
-#if _LIBCPP_DEBUG_LEVEL >= 2
-
-template <class _Tp, class _Allocator>
-bool
-vector<_Tp, _Allocator>::__dereferenceable(const const_iterator* __i) const
-{
-    return this->__begin_ <= __i->base() && __i->base() < this->__end_;
-}
-
-template <class _Tp, class _Allocator>
-bool
-vector<_Tp, _Allocator>::__decrementable(const const_iterator* __i) const
-{
-    return this->__begin_ < __i->base() && __i->base() <= this->__end_;
-}
-
-template <class _Tp, class _Allocator>
-bool
-vector<_Tp, _Allocator>::__addable(const const_iterator* __i, ptrdiff_t __n) const
-{
-    const_pointer __p = __i->base() + __n;
-    return this->__begin_ <= __p && __p <= this->__end_;
-}
-
-template <class _Tp, class _Allocator>
-bool
-vector<_Tp, _Allocator>::__subscriptable(const const_iterator* __i, ptrdiff_t __n) const
-{
-    const_pointer __p = __i->base() + __n;
-    return this->__begin_ <= __p && __p < this->__end_;
-}
-
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-vector<_Tp, _Allocator>::__invalidate_all_iterators()
-{
-#if _LIBCPP_DEBUG_LEVEL >= 2
-    __get_db()->__invalidate_all(this);
-#endif  // _LIBCPP_DEBUG_LEVEL >= 2
-}
-
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-vector<_Tp, _Allocator>::__invalidate_iterators_past(pointer __new_last) {
-#if _LIBCPP_DEBUG_LEVEL >= 2
-  __c_node* __c = __get_db()->__find_c_and_lock(this);
-  for (__i_node** __p = __c->end_; __p != __c->beg_; ) {
-    --__p;
-    const_iterator* __i = static_cast<const_iterator*>((*__p)->__i_);
-    if (__i->base() > __new_last) {
-      (*__p)->__c_ = nullptr;
-      if (--__c->end_ != __p)
-        memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
-    }
-  }
-  __get_db()->unlock();
-#else
-  ((void)__new_last);
-#endif
-}
-
-// vector<bool>
-
-template <class _Allocator> class vector<bool, _Allocator>;
-
-template <class _Allocator> struct hash<vector<bool, _Allocator> >;
-
-template <class _Allocator>
-struct __has_storage_type<vector<bool, _Allocator> >
-{
-    static const bool value = true;
-};
-
-template <class _Allocator>
-class _LIBCPP_TEMPLATE_VIS vector<bool, _Allocator>
-    : private __vector_base_common<true>
-{
-public:
-    typedef vector                                   __self;
-    typedef bool                                     value_type;
-    typedef _Allocator                               allocator_type;
-    typedef allocator_traits<allocator_type>         __alloc_traits;
-    typedef typename __alloc_traits::size_type       size_type;
-    typedef typename __alloc_traits::difference_type difference_type;
-    typedef size_type __storage_type;
-    typedef __bit_iterator<vector, false>            pointer;
-    typedef __bit_iterator<vector, true>             const_pointer;
-    typedef pointer                                  iterator;
-    typedef const_pointer                            const_iterator;
-    typedef _VSTD::reverse_iterator<iterator>         reverse_iterator;
-    typedef _VSTD::reverse_iterator<const_iterator>   const_reverse_iterator;
-
-private:
-    typedef typename __rebind_alloc_helper<__alloc_traits, __storage_type>::type __storage_allocator;
-    typedef allocator_traits<__storage_allocator>    __storage_traits;
-    typedef typename __storage_traits::pointer       __storage_pointer;
-    typedef typename __storage_traits::const_pointer __const_storage_pointer;
-
-    __storage_pointer                                      __begin_;
-    size_type                                              __size_;
-    __compressed_pair<size_type, __storage_allocator> __cap_alloc_;
-public:
-    typedef __bit_reference<vector>                  reference;
-    typedef __bit_const_reference<vector>            const_reference;
-private:
-    _LIBCPP_INLINE_VISIBILITY
-    size_type& __cap() _NOEXCEPT
-        {return __cap_alloc_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-    const size_type& __cap() const _NOEXCEPT
-        {return __cap_alloc_.first();}
-    _LIBCPP_INLINE_VISIBILITY
-    __storage_allocator& __alloc() _NOEXCEPT
-        {return __cap_alloc_.second();}
-    _LIBCPP_INLINE_VISIBILITY
-    const __storage_allocator& __alloc() const _NOEXCEPT
-        {return __cap_alloc_.second();}
-
-    static const unsigned __bits_per_word = static_cast<unsigned>(sizeof(__storage_type) * CHAR_BIT);
-
-    _LIBCPP_INLINE_VISIBILITY
-    static size_type __internal_cap_to_external(size_type __n) _NOEXCEPT
-        {return __n * __bits_per_word;}
-    _LIBCPP_INLINE_VISIBILITY
-    static size_type __external_cap_to_internal(size_type __n) _NOEXCEPT
-        {return (__n - 1) / __bits_per_word + 1;}
-
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    vector() _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value);
-
-    _LIBCPP_INLINE_VISIBILITY explicit vector(const allocator_type& __a)
-#if _LIBCPP_STD_VER <= 14
-        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value);
-#else
-        _NOEXCEPT;
-#endif
-    ~vector();
-    explicit vector(size_type __n);
-#if _LIBCPP_STD_VER > 11
-    explicit vector(size_type __n, const allocator_type& __a);
-#endif
-    vector(size_type __n, const value_type& __v);
-    vector(size_type __n, const value_type& __v, const allocator_type& __a);
-    template <class _InputIterator>
-        vector(_InputIterator __first, _InputIterator __last,
-               typename enable_if<__is_input_iterator  <_InputIterator>::value &&
-                                 !__is_forward_iterator<_InputIterator>::value>::type* = 0);
-    template <class _InputIterator>
-        vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a,
-               typename enable_if<__is_input_iterator  <_InputIterator>::value &&
-                                 !__is_forward_iterator<_InputIterator>::value>::type* = 0);
-    template <class _ForwardIterator>
-        vector(_ForwardIterator __first, _ForwardIterator __last,
-               typename enable_if<__is_forward_iterator<_ForwardIterator>::value>::type* = 0);
-    template <class _ForwardIterator>
-        vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a,
-               typename enable_if<__is_forward_iterator<_ForwardIterator>::value>::type* = 0);
-
-    vector(const vector& __v);
-    vector(const vector& __v, const allocator_type& __a);
-    vector& operator=(const vector& __v);
-
-#ifndef _LIBCPP_CXX03_LANG
-    vector(initializer_list<value_type> __il);
-    vector(initializer_list<value_type> __il, const allocator_type& __a);
-
-    _LIBCPP_INLINE_VISIBILITY
-    vector(vector&& __v)
-#if _LIBCPP_STD_VER > 14
-        _NOEXCEPT;
-#else
-        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value);
-#endif
-    vector(vector&& __v, const allocator_type& __a);
-    _LIBCPP_INLINE_VISIBILITY
-    vector& operator=(vector&& __v)
-        _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value));
-
-    _LIBCPP_INLINE_VISIBILITY
-    vector& operator=(initializer_list<value_type> __il)
-        {assign(__il.begin(), __il.end()); return *this;}
-
-#endif  // !_LIBCPP_CXX03_LANG
-
-    template <class _InputIterator>
-        typename enable_if
-        <
-            __is_input_iterator<_InputIterator>::value &&
-           !__is_forward_iterator<_InputIterator>::value,
-           void
-        >::type
-        assign(_InputIterator __first, _InputIterator __last);
-    template <class _ForwardIterator>
-        typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value,
-           void
-        >::type
-        assign(_ForwardIterator __first, _ForwardIterator __last);
-
-    void assign(size_type __n, const value_type& __x);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    void assign(initializer_list<value_type> __il)
-        {assign(__il.begin(), __il.end());}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY allocator_type get_allocator() const _NOEXCEPT
-        {return allocator_type(this->__alloc());}
-
-    size_type max_size() const _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    size_type capacity() const _NOEXCEPT
-        {return __internal_cap_to_external(__cap());}
-    _LIBCPP_INLINE_VISIBILITY
-    size_type size() const _NOEXCEPT
-        {return __size_;}
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
-    bool empty() const _NOEXCEPT
-        {return __size_ == 0;}
-    void reserve(size_type __n);
-    void shrink_to_fit() _NOEXCEPT;
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator begin() _NOEXCEPT
-        {return __make_iter(0);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator begin() const _NOEXCEPT
-        {return __make_iter(0);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator end() _NOEXCEPT
-        {return __make_iter(__size_);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator end()   const _NOEXCEPT
-        {return __make_iter(__size_);}
-
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator rbegin() _NOEXCEPT
-        {return       reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rbegin() const _NOEXCEPT
-        {return const_reverse_iterator(end());}
-    _LIBCPP_INLINE_VISIBILITY
-    reverse_iterator rend() _NOEXCEPT
-        {return       reverse_iterator(begin());}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator rend()   const _NOEXCEPT
-        {return const_reverse_iterator(begin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator         cbegin()  const _NOEXCEPT
-        {return __make_iter(0);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator         cend()    const _NOEXCEPT
-        {return __make_iter(__size_);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crbegin() const _NOEXCEPT
-        {return rbegin();}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reverse_iterator crend()   const _NOEXCEPT
-        {return rend();}
-
-    _LIBCPP_INLINE_VISIBILITY reference       operator[](size_type __n)       {return __make_ref(__n);}
-    _LIBCPP_INLINE_VISIBILITY const_reference operator[](size_type __n) const {return __make_ref(__n);}
-    reference       at(size_type __n);
-    const_reference at(size_type __n) const;
-
-    _LIBCPP_INLINE_VISIBILITY reference       front()       {return __make_ref(0);}
-    _LIBCPP_INLINE_VISIBILITY const_reference front() const {return __make_ref(0);}
-    _LIBCPP_INLINE_VISIBILITY reference       back()        {return __make_ref(__size_ - 1);}
-    _LIBCPP_INLINE_VISIBILITY const_reference back()  const {return __make_ref(__size_ - 1);}
-
-    void push_back(const value_type& __x);
-#if _LIBCPP_STD_VER > 11
-    template <class... _Args>
-#if _LIBCPP_STD_VER > 14
-    _LIBCPP_INLINE_VISIBILITY reference emplace_back(_Args&&... __args)
-#else
-    _LIBCPP_INLINE_VISIBILITY void      emplace_back(_Args&&... __args)
-#endif
-    {
-        push_back ( value_type ( _VSTD::forward<_Args>(__args)... ));
-#if _LIBCPP_STD_VER > 14
-        return this->back();
-#endif
-    }
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY void pop_back() {--__size_;}
-
-#if _LIBCPP_STD_VER > 11
-    template <class... _Args>
-   _LIBCPP_INLINE_VISIBILITY iterator emplace(const_iterator position, _Args&&... __args)
-        { return insert ( position, value_type ( _VSTD::forward<_Args>(__args)... )); }
-#endif
-
-    iterator insert(const_iterator __position, const value_type& __x);
-    iterator insert(const_iterator __position, size_type __n, const value_type& __x);
-    iterator insert(const_iterator __position, size_type __n, const_reference __x);
-    template <class _InputIterator>
-        typename enable_if
-        <
-             __is_input_iterator  <_InputIterator>::value &&
-            !__is_forward_iterator<_InputIterator>::value,
-            iterator
-        >::type
-        insert(const_iterator __position, _InputIterator __first, _InputIterator __last);
-    template <class _ForwardIterator>
-        typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value,
-            iterator
-        >::type
-        insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last);
-
-#ifndef _LIBCPP_CXX03_LANG
-    _LIBCPP_INLINE_VISIBILITY
-    iterator insert(const_iterator __position, initializer_list<value_type> __il)
-        {return insert(__position, __il.begin(), __il.end());}
-#endif
-
-    _LIBCPP_INLINE_VISIBILITY iterator erase(const_iterator __position);
-    iterator erase(const_iterator __first, const_iterator __last);
-
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {__size_ = 0;}
-
-    void swap(vector&)
-#if _LIBCPP_STD_VER >= 14
-        _NOEXCEPT;
-#else
-        _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
-                    __is_nothrow_swappable<allocator_type>::value);
-#endif
-    static void swap(reference __x, reference __y) _NOEXCEPT { _VSTD::swap(__x, __y); }
-
-    void resize(size_type __sz, value_type __x = false);
-    void flip() _NOEXCEPT;
-
-    bool __invariants() const;
-
-private:
-    _LIBCPP_INLINE_VISIBILITY void __invalidate_all_iterators();
-    void __vallocate(size_type __n);
-    void __vdeallocate() _NOEXCEPT;
-    _LIBCPP_INLINE_VISIBILITY
-    static size_type __align_it(size_type __new_size) _NOEXCEPT
-        {return __new_size + (__bits_per_word-1) & ~((size_type)__bits_per_word-1);}
-    _LIBCPP_INLINE_VISIBILITY  size_type __recommend(size_type __new_size) const;
-    _LIBCPP_INLINE_VISIBILITY void __construct_at_end(size_type __n, bool __x);
-    template <class _ForwardIterator>
-        typename enable_if
-        <
-            __is_forward_iterator<_ForwardIterator>::value,
-            void
-        >::type
-        __construct_at_end(_ForwardIterator __first, _ForwardIterator __last);
-    void __append(size_type __n, const_reference __x);
-    _LIBCPP_INLINE_VISIBILITY
-    reference __make_ref(size_type __pos) _NOEXCEPT
-        {return reference(__begin_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY
-    const_reference __make_ref(size_type __pos) const _NOEXCEPT
-        {return const_reference(__begin_ + __pos / __bits_per_word, __storage_type(1) << __pos % __bits_per_word);}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __make_iter(size_type __pos) _NOEXCEPT
-        {return iterator(__begin_ + __pos / __bits_per_word, static_cast<unsigned>(__pos % __bits_per_word));}
-    _LIBCPP_INLINE_VISIBILITY
-    const_iterator __make_iter(size_type __pos) const _NOEXCEPT
-        {return const_iterator(__begin_ + __pos / __bits_per_word, static_cast<unsigned>(__pos % __bits_per_word));}
-    _LIBCPP_INLINE_VISIBILITY
-    iterator __const_iterator_cast(const_iterator __p) _NOEXCEPT
-        {return begin() + (__p - cbegin());}
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const vector& __v)
-        {__copy_assign_alloc(__v, integral_constant<bool,
-                      __storage_traits::propagate_on_container_copy_assignment::value>());}
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const vector& __c, true_type)
-        {
-            if (__alloc() != __c.__alloc())
-                __vdeallocate();
-            __alloc() = __c.__alloc();
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __copy_assign_alloc(const vector&, false_type)
-        {}
-
-    void __move_assign(vector& __c, false_type);
-    void __move_assign(vector& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value);
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(vector& __c)
-        _NOEXCEPT_(
-            !__storage_traits::propagate_on_container_move_assignment::value ||
-            is_nothrow_move_assignable<allocator_type>::value)
-        {__move_assign_alloc(__c, integral_constant<bool,
-                      __storage_traits::propagate_on_container_move_assignment::value>());}
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(vector& __c, true_type)
-        _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-        {
-            __alloc() = _VSTD::move(__c.__alloc());
-        }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void __move_assign_alloc(vector&, false_type)
-        _NOEXCEPT
-        {}
-
-    size_t __hash_code() const _NOEXCEPT;
-
-    friend class __bit_reference<vector>;
-    friend class __bit_const_reference<vector>;
-    friend class __bit_iterator<vector, false>;
-    friend class __bit_iterator<vector, true>;
-    friend struct __bit_array<vector>;
-    friend struct _LIBCPP_TEMPLATE_VIS hash<vector>;
-};
-
-template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-vector<bool, _Allocator>::__invalidate_all_iterators()
-{
-}
-
-//  Allocate space for __n objects
-//  throws length_error if __n > max_size()
-//  throws (probably bad_alloc) if memory run out
-//  Precondition:  __begin_ == __end_ == __cap() == 0
-//  Precondition:  __n > 0
-//  Postcondition:  capacity() == __n
-//  Postcondition:  size() == 0
-template <class _Allocator>
-void
-vector<bool, _Allocator>::__vallocate(size_type __n)
-{
-    if (__n > max_size())
-        this->__throw_length_error();
-    __n = __external_cap_to_internal(__n);
-    this->__begin_ = __storage_traits::allocate(this->__alloc(), __n);
-    this->__size_ = 0;
-    this->__cap() = __n;
-}
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::__vdeallocate() _NOEXCEPT
-{
-    if (this->__begin_ != nullptr)
-    {
-        __storage_traits::deallocate(this->__alloc(), this->__begin_, __cap());
-        __invalidate_all_iterators();
-        this->__begin_ = nullptr;
-        this->__size_ = this->__cap() = 0;
-    }
-}
-
-template <class _Allocator>
-typename vector<bool, _Allocator>::size_type
-vector<bool, _Allocator>::max_size() const _NOEXCEPT
-{
-    size_type __amax = __storage_traits::max_size(__alloc());
-    size_type __nmax = numeric_limits<size_type>::max() / 2;  // end() >= begin(), always
-    if (__nmax / __bits_per_word <= __amax)
-        return __nmax;
-    return __internal_cap_to_external(__amax);
-}
-
-//  Precondition:  __new_size > capacity()
-template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<bool, _Allocator>::size_type
-vector<bool, _Allocator>::__recommend(size_type __new_size) const
-{
-    const size_type __ms = max_size();
-    if (__new_size > __ms)
-        this->__throw_length_error();
-    const size_type __cap = capacity();
-    if (__cap >= __ms / 2)
-        return __ms;
-    return _VSTD::max(2*__cap, __align_it(__new_size));
-}
-
-//  Default constructs __n objects starting at __end_
-//  Precondition:  __n > 0
-//  Precondition:  size() + __n <= capacity()
-//  Postcondition:  size() == size() + __n
-template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-vector<bool, _Allocator>::__construct_at_end(size_type __n, bool __x)
-{
-    size_type __old_size = this->__size_;
-    this->__size_ += __n;
-    if (__old_size == 0 || ((__old_size - 1) / __bits_per_word) != ((this->__size_ - 1) / __bits_per_word))
-    {
-        if (this->__size_ <= __bits_per_word)
-            this->__begin_[0] = __storage_type(0);
-        else
-            this->__begin_[(this->__size_ - 1) / __bits_per_word] = __storage_type(0);
-    }
-    _VSTD::fill_n(__make_iter(__old_size), __n, __x);
-}
-
-template <class _Allocator>
-template <class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value,
-    void
->::type
-vector<bool, _Allocator>::__construct_at_end(_ForwardIterator __first, _ForwardIterator __last)
-{
-    size_type __old_size = this->__size_;
-    this->__size_ += _VSTD::distance(__first, __last);
-    if (__old_size == 0 || ((__old_size - 1) / __bits_per_word) != ((this->__size_ - 1) / __bits_per_word))
-    {
-        if (this->__size_ <= __bits_per_word)
-            this->__begin_[0] = __storage_type(0);
-        else
-            this->__begin_[(this->__size_ - 1) / __bits_per_word] = __storage_type(0);
-    }
-    _VSTD::copy(__first, __last, __make_iter(__old_size));
-}
-
-template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-vector<bool, _Allocator>::vector()
-    _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0)
-{
-}
-
-template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-vector<bool, _Allocator>::vector(const allocator_type& __a)
-#if _LIBCPP_STD_VER <= 14
-        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
-#else
-        _NOEXCEPT
-#endif
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0, static_cast<__storage_allocator>(__a))
-{
-}
-
-template <class _Allocator>
-vector<bool, _Allocator>::vector(size_type __n)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0)
-{
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__n, false);
-    }
-}
-
-#if _LIBCPP_STD_VER > 11
-template <class _Allocator>
-vector<bool, _Allocator>::vector(size_type __n, const allocator_type& __a)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0, static_cast<__storage_allocator>(__a))
-{
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__n, false);
-    }
-}
-#endif
-
-template <class _Allocator>
-vector<bool, _Allocator>::vector(size_type __n, const value_type& __x)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0)
-{
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__n, __x);
-    }
-}
-
-template <class _Allocator>
-vector<bool, _Allocator>::vector(size_type __n, const value_type& __x, const allocator_type& __a)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0, static_cast<__storage_allocator>(__a))
-{
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__n, __x);
-    }
-}
-
-template <class _Allocator>
-template <class _InputIterator>
-vector<bool, _Allocator>::vector(_InputIterator __first, _InputIterator __last,
-       typename enable_if<__is_input_iterator  <_InputIterator>::value &&
-                         !__is_forward_iterator<_InputIterator>::value>::type*)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0)
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        for (; __first != __last; ++__first)
-            push_back(*__first);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        if (__begin_ != nullptr)
-            __storage_traits::deallocate(__alloc(), __begin_, __cap());
-        __invalidate_all_iterators();
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template <class _Allocator>
-template <class _InputIterator>
-vector<bool, _Allocator>::vector(_InputIterator __first, _InputIterator __last, const allocator_type& __a,
-       typename enable_if<__is_input_iterator  <_InputIterator>::value &&
-                         !__is_forward_iterator<_InputIterator>::value>::type*)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0, static_cast<__storage_allocator>(__a))
-{
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    try
-    {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-        for (; __first != __last; ++__first)
-            push_back(*__first);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-    }
-    catch (...)
-    {
-        if (__begin_ != nullptr)
-            __storage_traits::deallocate(__alloc(), __begin_, __cap());
-        __invalidate_all_iterators();
-        throw;
-    }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-}
-
-template <class _Allocator>
-template <class _ForwardIterator>
-vector<bool, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last,
-                                typename enable_if<__is_forward_iterator<_ForwardIterator>::value>::type*)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0)
-{
-    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__first, __last);
-    }
-}
-
-template <class _Allocator>
-template <class _ForwardIterator>
-vector<bool, _Allocator>::vector(_ForwardIterator __first, _ForwardIterator __last, const allocator_type& __a,
-                                typename enable_if<__is_forward_iterator<_ForwardIterator>::value>::type*)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0, static_cast<__storage_allocator>(__a))
-{
-    size_type __n = static_cast<size_type>(_VSTD::distance(__first, __last));
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__first, __last);
-    }
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Allocator>
-vector<bool, _Allocator>::vector(initializer_list<value_type> __il)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0)
-{
-    size_type __n = static_cast<size_type>(__il.size());
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__il.begin(), __il.end());
-    }
-}
-
-template <class _Allocator>
-vector<bool, _Allocator>::vector(initializer_list<value_type> __il, const allocator_type& __a)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0, static_cast<__storage_allocator>(__a))
-{
-    size_type __n = static_cast<size_type>(__il.size());
-    if (__n > 0)
-    {
-        __vallocate(__n);
-        __construct_at_end(__il.begin(), __il.end());
-    }
-}
-
-#endif  // _LIBCPP_CXX03_LANG
-
-template <class _Allocator>
-vector<bool, _Allocator>::~vector()
-{
-    if (__begin_ != nullptr)
-        __storage_traits::deallocate(__alloc(), __begin_, __cap());
-    __invalidate_all_iterators();
-}
-
-template <class _Allocator>
-vector<bool, _Allocator>::vector(const vector& __v)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0, __storage_traits::select_on_container_copy_construction(__v.__alloc()))
-{
-    if (__v.size() > 0)
-    {
-        __vallocate(__v.size());
-        __construct_at_end(__v.begin(), __v.end());
-    }
-}
-
-template <class _Allocator>
-vector<bool, _Allocator>::vector(const vector& __v, const allocator_type& __a)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0, __a)
-{
-    if (__v.size() > 0)
-    {
-        __vallocate(__v.size());
-        __construct_at_end(__v.begin(), __v.end());
-    }
-}
-
-template <class _Allocator>
-vector<bool, _Allocator>&
-vector<bool, _Allocator>::operator=(const vector& __v)
-{
-    if (this != &__v)
-    {
-        __copy_assign_alloc(__v);
-        if (__v.__size_)
-        {
-            if (__v.__size_ > capacity())
-            {
-                __vdeallocate();
-                __vallocate(__v.__size_);
-            }
-            _VSTD::copy(__v.__begin_, __v.__begin_ + __external_cap_to_internal(__v.__size_), __begin_);
-        }
-        __size_ = __v.__size_;
-    }
-    return *this;
-}
-
-#ifndef _LIBCPP_CXX03_LANG
-
-template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY vector<bool, _Allocator>::vector(vector&& __v)
-#if _LIBCPP_STD_VER > 14
-    _NOEXCEPT
-#else
-    _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
-#endif
-    : __begin_(__v.__begin_),
-      __size_(__v.__size_),
-      __cap_alloc_(std::move(__v.__cap_alloc_)) {
-    __v.__begin_ = nullptr;
-    __v.__size_ = 0;
-    __v.__cap() = 0;
-}
-
-template <class _Allocator>
-vector<bool, _Allocator>::vector(vector&& __v, const allocator_type& __a)
-    : __begin_(nullptr),
-      __size_(0),
-      __cap_alloc_(0, __a)
-{
-    if (__a == allocator_type(__v.__alloc()))
-    {
-        this->__begin_ = __v.__begin_;
-        this->__size_ = __v.__size_;
-        this->__cap() = __v.__cap();
-        __v.__begin_ = nullptr;
-        __v.__cap() = __v.__size_ = 0;
-    }
-    else if (__v.size() > 0)
-    {
-        __vallocate(__v.size());
-        __construct_at_end(__v.begin(), __v.end());
-    }
-}
-
-template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-vector<bool, _Allocator>&
-vector<bool, _Allocator>::operator=(vector&& __v)
-    _NOEXCEPT_((__noexcept_move_assign_container<_Allocator, __alloc_traits>::value))
-{
-    __move_assign(__v, integral_constant<bool,
-          __storage_traits::propagate_on_container_move_assignment::value>());
-    return *this;
-}
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::__move_assign(vector& __c, false_type)
-{
-    if (__alloc() != __c.__alloc())
-        assign(__c.begin(), __c.end());
-    else
-        __move_assign(__c, true_type());
-}
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::__move_assign(vector& __c, true_type)
-    _NOEXCEPT_(is_nothrow_move_assignable<allocator_type>::value)
-{
-    __vdeallocate();
-    __move_assign_alloc(__c);
-    this->__begin_ = __c.__begin_;
-    this->__size_ = __c.__size_;
-    this->__cap() = __c.__cap();
-    __c.__begin_ = nullptr;
-    __c.__cap() = __c.__size_ = 0;
-}
-
-#endif  // !_LIBCPP_CXX03_LANG
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::assign(size_type __n, const value_type& __x)
-{
-    __size_ = 0;
-    if (__n > 0)
-    {
-        size_type __c = capacity();
-        if (__n <= __c)
-            __size_ = __n;
-        else
-        {
-            vector __v(__alloc());
-            __v.reserve(__recommend(__n));
-            __v.__size_ = __n;
-            swap(__v);
-        }
-        _VSTD::fill_n(begin(), __n, __x);
-    }
-  __invalidate_all_iterators();
-}
-
-template <class _Allocator>
-template <class _InputIterator>
-typename enable_if
-<
-    __is_input_iterator<_InputIterator>::value &&
-   !__is_forward_iterator<_InputIterator>::value,
-   void
->::type
-vector<bool, _Allocator>::assign(_InputIterator __first, _InputIterator __last)
-{
-    clear();
-    for (; __first != __last; ++__first)
-        push_back(*__first);
-}
-
-template <class _Allocator>
-template <class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value,
-   void
->::type
-vector<bool, _Allocator>::assign(_ForwardIterator __first, _ForwardIterator __last)
-{
-    clear();
-    difference_type __ns = _VSTD::distance(__first, __last);
-    _LIBCPP_ASSERT(__ns >= 0, "invalid range specified");
-    const size_t __n = static_cast<size_type>(__ns);
-    if (__n)
-    {
-        if (__n > capacity())
-        {
-            __vdeallocate();
-            __vallocate(__n);
-        }
-        __construct_at_end(__first, __last);
-    }
-}
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::reserve(size_type __n)
-{
-    if (__n > capacity())
-    {
-        vector __v(this->__alloc());
-        __v.__vallocate(__n);
-        __v.__construct_at_end(this->begin(), this->end());
-        swap(__v);
-        __invalidate_all_iterators();
-    }
-}
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::shrink_to_fit() _NOEXCEPT
-{
-    if (__external_cap_to_internal(size()) > __cap())
-    {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            vector(*this, allocator_type(__alloc())).swap(*this);
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-}
-
-template <class _Allocator>
-typename vector<bool, _Allocator>::reference
-vector<bool, _Allocator>::at(size_type __n)
-{
-    if (__n >= size())
-        this->__throw_out_of_range();
-    return (*this)[__n];
-}
-
-template <class _Allocator>
-typename vector<bool, _Allocator>::const_reference
-vector<bool, _Allocator>::at(size_type __n) const
-{
-    if (__n >= size())
-        this->__throw_out_of_range();
-    return (*this)[__n];
-}
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::push_back(const value_type& __x)
-{
-    if (this->__size_ == this->capacity())
-        reserve(__recommend(this->__size_ + 1));
-    ++this->__size_;
-    back() = __x;
-}
-
-template <class _Allocator>
-typename vector<bool, _Allocator>::iterator
-vector<bool, _Allocator>::insert(const_iterator __position, const value_type& __x)
-{
-    iterator __r;
-    if (size() < capacity())
-    {
-        const_iterator __old_end = end();
-        ++__size_;
-        _VSTD::copy_backward(__position, __old_end, end());
-        __r = __const_iterator_cast(__position);
-    }
-    else
-    {
-        vector __v(__alloc());
-        __v.reserve(__recommend(__size_ + 1));
-        __v.__size_ = __size_ + 1;
-        __r = _VSTD::copy(cbegin(), __position, __v.begin());
-        _VSTD::copy_backward(__position, cend(), __v.end());
-        swap(__v);
-    }
-    *__r = __x;
-    return __r;
-}
-
-template <class _Allocator>
-typename vector<bool, _Allocator>::iterator
-vector<bool, _Allocator>::insert(const_iterator __position, size_type __n, const value_type& __x)
-{
-    iterator __r;
-    size_type __c = capacity();
-    if (__n <= __c && size() <= __c - __n)
-    {
-        const_iterator __old_end = end();
-        __size_ += __n;
-        _VSTD::copy_backward(__position, __old_end, end());
-        __r = __const_iterator_cast(__position);
-    }
-    else
-    {
-        vector __v(__alloc());
-        __v.reserve(__recommend(__size_ + __n));
-        __v.__size_ = __size_ + __n;
-        __r = _VSTD::copy(cbegin(), __position, __v.begin());
-        _VSTD::copy_backward(__position, cend(), __v.end());
-        swap(__v);
-    }
-    _VSTD::fill_n(__r, __n, __x);
-    return __r;
-}
-
-template <class _Allocator>
-template <class _InputIterator>
-typename enable_if
-<
-     __is_input_iterator  <_InputIterator>::value &&
-    !__is_forward_iterator<_InputIterator>::value,
-    typename vector<bool, _Allocator>::iterator
->::type
-vector<bool, _Allocator>::insert(const_iterator __position, _InputIterator __first, _InputIterator __last)
-{
-    difference_type __off = __position - begin();
-    iterator __p = __const_iterator_cast(__position);
-    iterator __old_end = end();
-    for (; size() != capacity() && __first != __last; ++__first)
-    {
-        ++this->__size_;
-        back() = *__first;
-    }
-    vector __v(__alloc());
-    if (__first != __last)
-    {
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        try
-        {
-#endif  // _LIBCPP_NO_EXCEPTIONS
-            __v.assign(__first, __last);
-            difference_type __old_size = static_cast<difference_type>(__old_end - begin());
-            difference_type __old_p = __p - begin();
-            reserve(__recommend(size() + __v.size()));
-            __p = begin() + __old_p;
-            __old_end = begin() + __old_size;
-#ifndef _LIBCPP_NO_EXCEPTIONS
-        }
-        catch (...)
-        {
-            erase(__old_end, end());
-            throw;
-        }
-#endif  // _LIBCPP_NO_EXCEPTIONS
-    }
-    __p = _VSTD::rotate(__p, __old_end, end());
-    insert(__p, __v.begin(), __v.end());
-    return begin() + __off;
-}
-
-template <class _Allocator>
-template <class _ForwardIterator>
-typename enable_if
-<
-    __is_forward_iterator<_ForwardIterator>::value,
-    typename vector<bool, _Allocator>::iterator
->::type
-vector<bool, _Allocator>::insert(const_iterator __position, _ForwardIterator __first, _ForwardIterator __last)
-{
-    const difference_type __n_signed = _VSTD::distance(__first, __last);
-    _LIBCPP_ASSERT(__n_signed >= 0, "invalid range specified");
-    const size_type __n = static_cast<size_type>(__n_signed);
-    iterator __r;
-    size_type __c = capacity();
-    if (__n <= __c && size() <= __c - __n)
-    {
-        const_iterator __old_end = end();
-        __size_ += __n;
-        _VSTD::copy_backward(__position, __old_end, end());
-        __r = __const_iterator_cast(__position);
-    }
-    else
-    {
-        vector __v(__alloc());
-        __v.reserve(__recommend(__size_ + __n));
-        __v.__size_ = __size_ + __n;
-        __r = _VSTD::copy(cbegin(), __position, __v.begin());
-        _VSTD::copy_backward(__position, cend(), __v.end());
-        swap(__v);
-    }
-    _VSTD::copy(__first, __last, __r);
-    return __r;
-}
-
-template <class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-typename vector<bool, _Allocator>::iterator
-vector<bool, _Allocator>::erase(const_iterator __position)
-{
-    iterator __r = __const_iterator_cast(__position);
-    _VSTD::copy(__position + 1, this->cend(), __r);
-    --__size_;
-    return __r;
-}
-
-template <class _Allocator>
-typename vector<bool, _Allocator>::iterator
-vector<bool, _Allocator>::erase(const_iterator __first, const_iterator __last)
-{
-    iterator __r = __const_iterator_cast(__first);
-    difference_type __d = __last - __first;
-    _VSTD::copy(__last, this->cend(), __r);
-    __size_ -= __d;
-    return __r;
-}
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::swap(vector& __x)
-#if _LIBCPP_STD_VER >= 14
-    _NOEXCEPT
-#else
-    _NOEXCEPT_(!__alloc_traits::propagate_on_container_swap::value ||
-                __is_nothrow_swappable<allocator_type>::value)
-#endif
-{
-    _VSTD::swap(this->__begin_, __x.__begin_);
-    _VSTD::swap(this->__size_, __x.__size_);
-    _VSTD::swap(this->__cap(), __x.__cap());
-    __swap_allocator(this->__alloc(), __x.__alloc(),
-        integral_constant<bool, __alloc_traits::propagate_on_container_swap::value>());
-}
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::resize(size_type __sz, value_type __x)
-{
-    size_type __cs = size();
-    if (__cs < __sz)
-    {
-        iterator __r;
-        size_type __c = capacity();
-        size_type __n = __sz - __cs;
-        if (__n <= __c && __cs <= __c - __n)
-        {
-            __r = end();
-            __size_ += __n;
-        }
-        else
-        {
-            vector __v(__alloc());
-            __v.reserve(__recommend(__size_ + __n));
-            __v.__size_ = __size_ + __n;
-            __r = _VSTD::copy(cbegin(), cend(), __v.begin());
-            swap(__v);
-        }
-        _VSTD::fill_n(__r, __n, __x);
-    }
-    else
-        __size_ = __sz;
-}
-
-template <class _Allocator>
-void
-vector<bool, _Allocator>::flip() _NOEXCEPT
-{
-    // do middle whole words
-    size_type __n = __size_;
-    __storage_pointer __p = __begin_;
-    for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
-        *__p = ~*__p;
-    // do last partial word
-    if (__n > 0)
-    {
-        __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        __storage_type __b = *__p & __m;
-        *__p &= ~__m;
-        *__p |= ~__b & __m;
-    }
-}
-
-template <class _Allocator>
-bool
-vector<bool, _Allocator>::__invariants() const
-{
-    if (this->__begin_ == nullptr)
-    {
-        if (this->__size_ != 0 || this->__cap() != 0)
-            return false;
-    }
-    else
-    {
-        if (this->__cap() == 0)
-            return false;
-        if (this->__size_ > this->capacity())
-            return false;
-    }
-    return true;
-}
-
-template <class _Allocator>
-size_t
-vector<bool, _Allocator>::__hash_code() const _NOEXCEPT
-{
-    size_t __h = 0;
-    // do middle whole words
-    size_type __n = __size_;
-    __storage_pointer __p = __begin_;
-    for (; __n >= __bits_per_word; ++__p, __n -= __bits_per_word)
-        __h ^= *__p;
-    // do last partial word
-    if (__n > 0)
-    {
-        const __storage_type __m = ~__storage_type(0) >> (__bits_per_word - __n);
-        __h ^= *__p & __m;
-    }
-    return __h;
-}
-
-template <class _Allocator>
-struct _LIBCPP_TEMPLATE_VIS hash<vector<bool, _Allocator> >
-    : public unary_function<vector<bool, _Allocator>, size_t>
-{
-    _LIBCPP_INLINE_VISIBILITY
-    size_t operator()(const vector<bool, _Allocator>& __vec) const _NOEXCEPT
-        {return __vec.__hash_code();}
-};
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator==(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
-{
-    const typename vector<_Tp, _Allocator>::size_type __sz = __x.size();
-    return __sz == __y.size() && _VSTD::equal(__x.begin(), __x.end(), __y.begin());
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator!=(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
-{
-    return !(__x == __y);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator< (const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
-{
-    return _VSTD::lexicographical_compare(__x.begin(), __x.end(), __y.begin(), __y.end());
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator> (const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
-{
-    return __y < __x;
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator>=(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
-{
-    return !(__x < __y);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-bool
-operator<=(const vector<_Tp, _Allocator>& __x, const vector<_Tp, _Allocator>& __y)
-{
-    return !(__y < __x);
-}
-
-template <class _Tp, class _Allocator>
-inline _LIBCPP_INLINE_VISIBILITY
-void
-swap(vector<_Tp, _Allocator>& __x, vector<_Tp, _Allocator>& __y)
-    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
-{
-    __x.swap(__y);
-}
-
-#if _LIBCPP_STD_VER > 17
-template <class _Tp, class _Allocator, class _Up>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase(vector<_Tp, _Allocator>& __c, const _Up& __v)
-{ __c.erase(_VSTD::remove(__c.begin(), __c.end(), __v), __c.end()); }
-
-template <class _Tp, class _Allocator, class _Predicate>
-inline _LIBCPP_INLINE_VISIBILITY
-void erase_if(vector<_Tp, _Allocator>& __c, _Predicate __pred)
-{ __c.erase(_VSTD::remove_if(__c.begin(), __c.end(), __pred), __c.end()); }
-#endif
-
-_LIBCPP_END_NAMESPACE_STD
-
-_LIBCPP_POP_MACROS
-
-#endif  // _LIBCPP_VECTOR
diff --git a/lib/libcxx/include/version b/lib/libcxx/include/version
deleted file mode 100644
index e37afc44860..00000000000
--- a/lib/libcxx/include/version
+++ /dev/null
@@ -1,232 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- version ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_VERSIONH
-#define _LIBCPP_VERSIONH
-
-/*
-  version synopsis
-
-Macro name                                              Value   Headers
-__cpp_lib_addressof_constexpr                           201603L <memory>
-__cpp_lib_allocator_traits_is_always_equal              201411L <memory> <scoped_allocator> <string>
-                                                                <deque> <forward_list> <list>
-                                                                <vector> <map> <set>
-                                                                <unordered_map> <unordered_set>
-__cpp_lib_any                                           201606L <any>
-__cpp_lib_apply                                         201603L <tuple>
-__cpp_lib_array_constexpr                               201603L <iterator> <array>
-__cpp_lib_as_const                                      201510L <utility>
-__cpp_lib_atomic_is_always_lock_free                    201603L <atomic>
-__cpp_lib_atomic_ref                                    201806L <atomic>
-__cpp_lib_bind_front                                    201811L <functional>
-__cpp_lib_bit_cast                                      201806L <bit>
-__cpp_lib_bool_constant                                 201505L <type_traits>
-__cpp_lib_boyer_moore_searcher                          201603L <functional>
-__cpp_lib_byte                                          201603L <cstddef>
-__cpp_lib_char8_t                                       201811L <atomic> <filesystem> <istream>
-                                                                <limits> <locale> <ostream>
-                                                                <string> <string_view>
-__cpp_lib_chrono                                        201611L <chrono>
-__cpp_lib_chrono_udls                                   201304L <chrono>
-__cpp_lib_clamp                                         201603L <algorithm>
-__cpp_lib_complex_udls                                  201309L <complex>
-__cpp_lib_concepts                                      201806L <concepts>
-__cpp_lib_constexpr_misc                                201811L <array> <functional> <iterator>
-                                                                <string_view> <tuple> <utility>
-__cpp_lib_constexpr_swap_algorithms                     201806L <algorithm>
-__cpp_lib_destroying_delete                             201806L <new>
-__cpp_lib_enable_shared_from_this                       201603L <memory>
-__cpp_lib_erase_if                                      201811L <string> <deque> <forward_list>
-                                                                <list> <vector> <map>
-                                                                <set> <unordered_map> <unordered_set>
-__cpp_lib_exchange_function                             201304L <utility>
-__cpp_lib_execution                                     201603L <execution>
-__cpp_lib_filesystem                                    201703L <filesystem>
-__cpp_lib_gcd_lcm                                       201606L <numeric>
-__cpp_lib_generic_associative_lookup                    201304L <map> <set>
-__cpp_lib_generic_unordered_lookup                      201811L <unordered_map> <unordered_set>
-__cpp_lib_hardware_interference_size                    201703L <new>
-__cpp_lib_has_unique_object_representations             201606L <type_traits>
-__cpp_lib_hypot                                         201603L <cmath>
-__cpp_lib_incomplete_container_elements                 201505L <forward_list> <list> <vector>
-__cpp_lib_integer_sequence                              201304L <utility>
-__cpp_lib_integral_constant_callable                    201304L <type_traits>
-__cpp_lib_invoke                                        201411L <functional>
-__cpp_lib_is_aggregate                                  201703L <type_traits>
-__cpp_lib_is_constant_evaluated                         201811L <type_traits>
-__cpp_lib_is_final                                      201402L <type_traits>
-__cpp_lib_is_invocable                                  201703L <type_traits>
-__cpp_lib_is_null_pointer                               201309L <type_traits>
-__cpp_lib_is_swappable                                  201603L <type_traits>
-__cpp_lib_launder                                       201606L <new>
-__cpp_lib_list_remove_return_type                       201806L <forward_list> <list>
-__cpp_lib_logical_traits                                201510L <type_traits>
-__cpp_lib_make_from_tuple                               201606L <tuple>
-__cpp_lib_make_reverse_iterator                         201402L <iterator>
-__cpp_lib_make_unique                                   201304L <memory>
-__cpp_lib_map_try_emplace                               201411L <map>
-__cpp_lib_math_special_functions                        201603L <cmath>
-__cpp_lib_memory_resource                               201603L <memory_resource>
-__cpp_lib_node_extract                                  201606L <map> <set> <unordered_map>
-                                                                <unordered_set>
-__cpp_lib_nonmember_container_access                    201411L <iterator> <array> <deque>
-                                                                <forward_list> <list> <map>
-                                                                <regex> <set> <string>
-                                                                <unordered_map> <unordered_set> <vector>
-__cpp_lib_not_fn                                        201603L <functional>
-__cpp_lib_null_iterators                                201304L <iterator>
-__cpp_lib_optional                                      201606L <optional>
-__cpp_lib_parallel_algorithm                            201603L <algorithm> <numeric>
-__cpp_lib_quoted_string_io                              201304L <iomanip>
-__cpp_lib_ranges                                        201811L <algorithm> <functional> <iterator>
-                                                                <memory> <ranges>
-__cpp_lib_raw_memory_algorithms                         201606L <memory>
-__cpp_lib_result_of_sfinae                              201210L <functional> <type_traits>
-__cpp_lib_robust_nonmodifying_seq_ops                   201304L <algorithm>
-__cpp_lib_sample                                        201603L <algorithm>
-__cpp_lib_scoped_lock                                   201703L <mutex>
-__cpp_lib_shared_mutex                                  201505L <shared_mutex>
-__cpp_lib_shared_ptr_arrays                             201611L <memory>
-__cpp_lib_shared_ptr_weak_type                          201606L <memory>
-__cpp_lib_shared_timed_mutex                            201402L <shared_mutex>
-__cpp_lib_string_udls                                   201304L <string>
-__cpp_lib_string_view                                   201606L <string> <string_view>
-__cpp_lib_three_way_comparison                          201711L <compare>
-__cpp_lib_to_chars                                      201611L <utility>
-__cpp_lib_transformation_trait_aliases                  201304L <type_traits>
-__cpp_lib_transparent_operators                         201510L <functional>
-                                                        201210L // C++14
-__cpp_lib_tuple_element_t                               201402L <tuple>
-__cpp_lib_tuples_by_type                                201304L <utility> <tuple>
-__cpp_lib_type_trait_variable_templates                 201510L <type_traits>
-__cpp_lib_uncaught_exceptions                           201411L <exception>
-__cpp_lib_unordered_map_try_emplace                     201411L <unordered_map>
-__cpp_lib_variant                                       201606L <variant>
-__cpp_lib_void_t                                        201411L <type_traits>
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#if _LIBCPP_STD_VER > 11
-# define __cpp_lib_chrono_udls                          201304L
-# define __cpp_lib_complex_udls                         201309L
-# define __cpp_lib_exchange_function                    201304L
-# define __cpp_lib_generic_associative_lookup           201304L
-# define __cpp_lib_integer_sequence                     201304L
-# define __cpp_lib_integral_constant_callable           201304L
-# define __cpp_lib_is_final                             201402L
-# define __cpp_lib_is_null_pointer                      201309L
-# define __cpp_lib_make_reverse_iterator                201402L
-# define __cpp_lib_make_unique                          201304L
-# define __cpp_lib_null_iterators                       201304L
-# define __cpp_lib_quoted_string_io                     201304L
-# define __cpp_lib_result_of_sfinae                     201210L
-# define __cpp_lib_robust_nonmodifying_seq_ops          201304L
-# if !defined(_LIBCPP_HAS_NO_THREADS)
-#   define __cpp_lib_shared_timed_mutex                 201402L
-# endif
-# define __cpp_lib_string_udls                          201304L
-# define __cpp_lib_transformation_trait_aliases         201304L
-# define __cpp_lib_transparent_operators                201210L
-# define __cpp_lib_tuple_element_t                      201402L
-# define __cpp_lib_tuples_by_type                       201304L
-#endif
-
-#if _LIBCPP_STD_VER > 14
-# if !defined(_LIBCPP_HAS_NO_BUILTIN_ADDRESSOF)
-#   define __cpp_lib_addressof_constexpr                201603L
-# endif
-# define __cpp_lib_allocator_traits_is_always_equal     201411L
-# define __cpp_lib_any                                  201606L
-# define __cpp_lib_apply                                201603L
-# define __cpp_lib_array_constexpr                      201603L
-# define __cpp_lib_as_const                             201510L
-# if !defined(_LIBCPP_HAS_NO_THREADS)
-#   define __cpp_lib_atomic_is_always_lock_free         201603L
-# endif
-# define __cpp_lib_bool_constant                        201505L
-// # define __cpp_lib_boyer_moore_searcher                 201603L
-# define __cpp_lib_byte                                 201603L
-# define __cpp_lib_chrono                               201611L
-# define __cpp_lib_clamp                                201603L
-# define __cpp_lib_enable_shared_from_this              201603L
-// # define __cpp_lib_execution                            201603L
-# define __cpp_lib_filesystem                           201703L
-# define __cpp_lib_gcd_lcm                              201606L
-# define __cpp_lib_hardware_interference_size           201703L
-# if defined(_LIBCPP_HAS_UNIQUE_OBJECT_REPRESENTATIONS)
-#   define __cpp_lib_has_unique_object_representations  201606L
-# endif
-# define __cpp_lib_hypot                                201603L
-# define __cpp_lib_incomplete_container_elements        201505L
-# define __cpp_lib_invoke                               201411L
-# if !defined(_LIBCPP_HAS_NO_IS_AGGREGATE)
-#   define __cpp_lib_is_aggregate                       201703L
-# endif
-# define __cpp_lib_is_invocable                         201703L
-# define __cpp_lib_is_swappable                         201603L
-# define __cpp_lib_launder                              201606L
-# define __cpp_lib_logical_traits                       201510L
-# define __cpp_lib_make_from_tuple                      201606L
-# define __cpp_lib_map_try_emplace                      201411L
-// # define __cpp_lib_math_special_functions               201603L
-// # define __cpp_lib_memory_resource                      201603L
-# define __cpp_lib_node_extract                         201606L
-# define __cpp_lib_nonmember_container_access           201411L
-# define __cpp_lib_not_fn                               201603L
-# define __cpp_lib_optional                             201606L
-// # define __cpp_lib_parallel_algorithm                   201603L
-# define __cpp_lib_raw_memory_algorithms                201606L
-# define __cpp_lib_sample                               201603L
-# define __cpp_lib_scoped_lock                          201703L
-# if !defined(_LIBCPP_HAS_NO_THREADS)
-#   define __cpp_lib_shared_mutex                       201505L
-# endif
-// # define __cpp_lib_shared_ptr_arrays                    201611L
-# define __cpp_lib_shared_ptr_weak_type                 201606L
-# define __cpp_lib_string_view                          201606L
-// # define __cpp_lib_to_chars                             201611L
-# undef  __cpp_lib_transparent_operators
-# define __cpp_lib_transparent_operators                201510L
-# define __cpp_lib_type_trait_variable_templates        201510L
-# define __cpp_lib_uncaught_exceptions                  201411L
-# define __cpp_lib_unordered_map_try_emplace            201411L
-# define __cpp_lib_variant                              201606L
-# define __cpp_lib_void_t                               201411L
-#endif
-
-#if _LIBCPP_STD_VER > 17
-# if !defined(_LIBCPP_HAS_NO_THREADS)
-// #   define __cpp_lib_atomic_ref                         201806L
-# endif
-// # define __cpp_lib_bind_front                           201811L
-// # define __cpp_lib_bit_cast                             201806L
-# if !defined(_LIBCPP_NO_HAS_CHAR8_T)
-#   define __cpp_lib_char8_t                            201811L
-# endif
-// # define __cpp_lib_concepts                             201806L
-// # define __cpp_lib_constexpr_misc                       201811L
-// # define __cpp_lib_constexpr_swap_algorithms            201806L
-// # define __cpp_lib_destroying_delete                    201806L
-# define __cpp_lib_erase_if                             201811L
-// # define __cpp_lib_generic_unordered_lookup             201811L
-// # define __cpp_lib_is_constant_evaluated                201811L
-// # define __cpp_lib_list_remove_return_type              201806L
-// # define __cpp_lib_ranges                               201811L
-// # define __cpp_lib_three_way_comparison                 201711L
-#endif
-
-#endif // _LIBCPP_VERSIONH
diff --git a/lib/libcxx/include/wchar.h b/lib/libcxx/include/wchar.h
deleted file mode 100644
index f74fe6ddcff..00000000000
--- a/lib/libcxx/include/wchar.h
+++ /dev/null
@@ -1,182 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- wchar.h ----------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#if defined(__need_wint_t) || defined(__need_mbstate_t)
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <wchar.h>
-
-#elif !defined(_LIBCPP_WCHAR_H)
-#define _LIBCPP_WCHAR_H
-
-/*
-    wchar.h synopsis
-
-Macros:
-
-    NULL
-    WCHAR_MAX
-    WCHAR_MIN
-    WEOF
-
-Types:
-
-    mbstate_t
-    size_t
-    tm
-    wint_t
-
-int fwprintf(FILE* restrict stream, const wchar_t* restrict format, ...);
-int fwscanf(FILE* restrict stream, const wchar_t* restrict format, ...);
-int swprintf(wchar_t* restrict s, size_t n, const wchar_t* restrict format, ...);
-int swscanf(const wchar_t* restrict s, const wchar_t* restrict format, ...);
-int vfwprintf(FILE* restrict stream, const wchar_t* restrict format, va_list arg);
-int vfwscanf(FILE* restrict stream, const wchar_t* restrict format, va_list arg);  // C99
-int vswprintf(wchar_t* restrict s, size_t n, const wchar_t* restrict format, va_list arg);
-int vswscanf(const wchar_t* restrict s, const wchar_t* restrict format, va_list arg);  // C99
-int vwprintf(const wchar_t* restrict format, va_list arg);
-int vwscanf(const wchar_t* restrict format, va_list arg);  // C99
-int wprintf(const wchar_t* restrict format, ...);
-int wscanf(const wchar_t* restrict format, ...);
-wint_t fgetwc(FILE* stream);
-wchar_t* fgetws(wchar_t* restrict s, int n, FILE* restrict stream);
-wint_t fputwc(wchar_t c, FILE* stream);
-int fputws(const wchar_t* restrict s, FILE* restrict stream);
-int fwide(FILE* stream, int mode);
-wint_t getwc(FILE* stream);
-wint_t getwchar();
-wint_t putwc(wchar_t c, FILE* stream);
-wint_t putwchar(wchar_t c);
-wint_t ungetwc(wint_t c, FILE* stream);
-double wcstod(const wchar_t* restrict nptr, wchar_t** restrict endptr);
-float wcstof(const wchar_t* restrict nptr, wchar_t** restrict endptr);         // C99
-long double wcstold(const wchar_t* restrict nptr, wchar_t** restrict endptr);  // C99
-long wcstol(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
-long long wcstoll(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);  // C99
-unsigned long wcstoul(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);
-unsigned long long wcstoull(const wchar_t* restrict nptr, wchar_t** restrict endptr, int base);  // C99
-wchar_t* wcscpy(wchar_t* restrict s1, const wchar_t* restrict s2);
-wchar_t* wcsncpy(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-wchar_t* wcscat(wchar_t* restrict s1, const wchar_t* restrict s2);
-wchar_t* wcsncat(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-int wcscmp(const wchar_t* s1, const wchar_t* s2);
-int wcscoll(const wchar_t* s1, const wchar_t* s2);
-int wcsncmp(const wchar_t* s1, const wchar_t* s2, size_t n);
-size_t wcsxfrm(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-const wchar_t* wcschr(const wchar_t* s, wchar_t c);
-      wchar_t* wcschr(      wchar_t* s, wchar_t c);
-size_t wcscspn(const wchar_t* s1, const wchar_t* s2);
-size_t wcslen(const wchar_t* s);
-const wchar_t* wcspbrk(const wchar_t* s1, const wchar_t* s2);
-      wchar_t* wcspbrk(      wchar_t* s1, const wchar_t* s2);
-const wchar_t* wcsrchr(const wchar_t* s, wchar_t c);
-      wchar_t* wcsrchr(      wchar_t* s, wchar_t c);
-size_t wcsspn(const wchar_t* s1, const wchar_t* s2);
-const wchar_t* wcsstr(const wchar_t* s1, const wchar_t* s2);
-      wchar_t* wcsstr(      wchar_t* s1, const wchar_t* s2);
-wchar_t* wcstok(wchar_t* restrict s1, const wchar_t* restrict s2, wchar_t** restrict ptr);
-const wchar_t* wmemchr(const wchar_t* s, wchar_t c, size_t n);
-      wchar_t* wmemchr(      wchar_t* s, wchar_t c, size_t n);
-int wmemcmp(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-wchar_t* wmemcpy(wchar_t* restrict s1, const wchar_t* restrict s2, size_t n);
-wchar_t* wmemmove(wchar_t* s1, const wchar_t* s2, size_t n);
-wchar_t* wmemset(wchar_t* s, wchar_t c, size_t n);
-size_t wcsftime(wchar_t* restrict s, size_t maxsize, const wchar_t* restrict format,
-                const tm* restrict timeptr);
-wint_t btowc(int c);
-int wctob(wint_t c);
-int mbsinit(const mbstate_t* ps);
-size_t mbrlen(const char* restrict s, size_t n, mbstate_t* restrict ps);
-size_t mbrtowc(wchar_t* restrict pwc, const char* restrict s, size_t n, mbstate_t* restrict ps);
-size_t wcrtomb(char* restrict s, wchar_t wc, mbstate_t* restrict ps);
-size_t mbsrtowcs(wchar_t* restrict dst, const char** restrict src, size_t len,
-                 mbstate_t* restrict ps);
-size_t wcsrtombs(char* restrict dst, const wchar_t** restrict src, size_t len,
-                 mbstate_t* restrict ps);
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#ifdef __cplusplus
-#define __CORRECT_ISO_CPP_WCHAR_H_PROTO
-#endif
-
-#include_next <wchar.h>
-
-// Determine whether we have const-correct overloads for wcschr and friends.
-#if defined(_WCHAR_H_CPLUSPLUS_98_CONFORMANCE_)
-#  define _LIBCPP_WCHAR_H_HAS_CONST_OVERLOADS 1
-#elif defined(__GLIBC_PREREQ)
-#  if __GLIBC_PREREQ(2, 10)
-#    define _LIBCPP_WCHAR_H_HAS_CONST_OVERLOADS 1
-#  endif
-#elif defined(_LIBCPP_MSVCRT)
-#  if defined(_CRT_CONST_CORRECT_OVERLOADS)
-#    define _LIBCPP_WCHAR_H_HAS_CONST_OVERLOADS 1
-#  endif
-#endif
-
-#if defined(__cplusplus) && !defined(_LIBCPP_WCHAR_H_HAS_CONST_OVERLOADS) && defined(_LIBCPP_PREFERRED_OVERLOAD)
-extern "C++" {
-inline _LIBCPP_INLINE_VISIBILITY
-wchar_t* __libcpp_wcschr(const wchar_t* __s, wchar_t __c) {return (wchar_t*)wcschr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const wchar_t* wcschr(const wchar_t* __s, wchar_t __c) {return __libcpp_wcschr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      wchar_t* wcschr(      wchar_t* __s, wchar_t __c) {return __libcpp_wcschr(__s, __c);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-wchar_t* __libcpp_wcspbrk(const wchar_t* __s1, const wchar_t* __s2) {return (wchar_t*)wcspbrk(__s1, __s2);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const wchar_t* wcspbrk(const wchar_t* __s1, const wchar_t* __s2) {return __libcpp_wcspbrk(__s1, __s2);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      wchar_t* wcspbrk(      wchar_t* __s1, const wchar_t* __s2) {return __libcpp_wcspbrk(__s1, __s2);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-wchar_t* __libcpp_wcsrchr(const wchar_t* __s, wchar_t __c) {return (wchar_t*)wcsrchr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const wchar_t* wcsrchr(const wchar_t* __s, wchar_t __c) {return __libcpp_wcsrchr(__s, __c);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      wchar_t* wcsrchr(      wchar_t* __s, wchar_t __c) {return __libcpp_wcsrchr(__s, __c);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-wchar_t* __libcpp_wcsstr(const wchar_t* __s1, const wchar_t* __s2) {return (wchar_t*)wcsstr(__s1, __s2);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const wchar_t* wcsstr(const wchar_t* __s1, const wchar_t* __s2) {return __libcpp_wcsstr(__s1, __s2);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      wchar_t* wcsstr(      wchar_t* __s1, const wchar_t* __s2) {return __libcpp_wcsstr(__s1, __s2);}
-
-inline _LIBCPP_INLINE_VISIBILITY
-wchar_t* __libcpp_wmemchr(const wchar_t* __s, wchar_t __c, size_t __n) {return (wchar_t*)wmemchr(__s, __c, __n);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-const wchar_t* wmemchr(const wchar_t* __s, wchar_t __c, size_t __n) {return __libcpp_wmemchr(__s, __c, __n);}
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_PREFERRED_OVERLOAD
-      wchar_t* wmemchr(      wchar_t* __s, wchar_t __c, size_t __n) {return __libcpp_wmemchr(__s, __c, __n);}
-}
-#endif
-
-#if defined(__cplusplus) && defined(_LIBCPP_MSVCRT_LIKE)
-extern "C" {
-size_t mbsnrtowcs(wchar_t *__restrict dst, const char **__restrict src,
-                  size_t nmc, size_t len, mbstate_t *__restrict ps);
-size_t wcsnrtombs(char *__restrict dst, const wchar_t **__restrict src,
-                  size_t nwc, size_t len, mbstate_t *__restrict ps);
-}  // extern "C++"
-#endif  // __cplusplus && _LIBCPP_MSVCRT
-
-#endif  // _LIBCPP_WCHAR_H
diff --git a/lib/libcxx/include/wctype.h b/lib/libcxx/include/wctype.h
deleted file mode 100644
index f9c5a47754b..00000000000
--- a/lib/libcxx/include/wctype.h
+++ /dev/null
@@ -1,79 +0,0 @@
-// -*- C++ -*-
-//===--------------------------- wctype.h ---------------------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is dual licensed under the MIT and the University of Illinois Open
-// Source Licenses. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-
-#ifndef _LIBCPP_WCTYPE_H
-#define _LIBCPP_WCTYPE_H
-
-/*
-    wctype.h synopsis
-
-Macros:
-
-    WEOF
-
-Types:
-
-    wint_t
-    wctrans_t
-    wctype_t
-
-int iswalnum(wint_t wc);
-int iswalpha(wint_t wc);
-int iswblank(wint_t wc);  // C99
-int iswcntrl(wint_t wc);
-int iswdigit(wint_t wc);
-int iswgraph(wint_t wc);
-int iswlower(wint_t wc);
-int iswprint(wint_t wc);
-int iswpunct(wint_t wc);
-int iswspace(wint_t wc);
-int iswupper(wint_t wc);
-int iswxdigit(wint_t wc);
-int iswctype(wint_t wc, wctype_t desc);
-wctype_t wctype(const char* property);
-wint_t towlower(wint_t wc);
-wint_t towupper(wint_t wc);
-wint_t towctrans(wint_t wc, wctrans_t desc);
-wctrans_t wctrans(const char* property);
-
-*/
-
-#include <__config>
-
-#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
-#pragma GCC system_header
-#endif
-
-#include_next <wctype.h>
-
-#ifdef __cplusplus
-
-#undef iswalnum
-#undef iswalpha
-#undef iswblank
-#undef iswcntrl
-#undef iswdigit
-#undef iswgraph
-#undef iswlower
-#undef iswprint
-#undef iswpunct
-#undef iswspace
-#undef iswupper
-#undef iswxdigit
-#undef iswctype
-#undef wctype
-#undef towlower
-#undef towupper
-#undef towctrans
-#undef wctrans
-
-#endif  // __cplusplus
-
-#endif  // _LIBCPP_WCTYPE_H