Remove libc++ and libc++abi 8.0.0 now that we switched to version 10.0.1

in the gnu/ directory.

1 files changed, 0 insertions, 5676 deletions

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