Import libc++ 7.0.1.

1 files changed, 84 insertions, 1967 deletions

diff --git a/lib/libcxx/include/experimental/filesystem b/lib/libcxx/include/experimental/filesystem
index 674490f6038..28d8dcf4fc1 100644
--- a/lib/libcxx/include/experimental/filesystem
+++ b/lib/libcxx/include/experimental/filesystem
@@ -16,24 +16,25 @@
 
     class path;
 
-    void swap(path& lhs, path& rhs) _NOEXCEPT;
-    size_t hash_value(const path& p) _NOEXCEPT;
+    void swap(path& lhs, path& rhs) noexcept;
+    size_t hash_value(const path& p) noexcept;
 
-    bool operator==(const path& lhs, const path& rhs) _NOEXCEPT;
-    bool operator!=(const path& lhs, const path& rhs) _NOEXCEPT;
-    bool operator< (const path& lhs, const path& rhs) _NOEXCEPT;
-    bool operator<=(const path& lhs, const path& rhs) _NOEXCEPT;
-    bool operator> (const path& lhs, const path& rhs) _NOEXCEPT;
-    bool operator>=(const path& lhs, const path& rhs) _NOEXCEPT;
+    bool operator==(const path& lhs, const path& rhs) noexcept;
+    bool operator!=(const path& lhs, const path& rhs) noexcept;
+    bool operator< (const path& lhs, const path& rhs) noexcept;
+    bool operator<=(const path& lhs, const path& rhs) noexcept;
+    bool operator> (const path& lhs, const path& rhs) noexcept;
+    bool operator>=(const path& lhs, const path& rhs) noexcept;
 
     path operator/ (const path& lhs, const path& rhs);
 
+    // fs.path.io operators are friends of path.
     template <class charT, class traits>
-    basic_ostream<charT, traits>&
+    friend basic_ostream<charT, traits>&
     operator<<(basic_ostream<charT, traits>& os, const path& p);
 
     template <class charT, class traits>
-    basic_istream<charT, traits>&
+    friend basic_istream<charT, traits>&
     operator>>(basic_istream<charT, traits>& is, path& p);
 
     template <class Source>
@@ -67,6 +68,7 @@
 
     enum class file_type;
     enum class perms;
+    enum class perm_options;
     enum class copy_options;
     enum class directory_options;
 
@@ -74,11 +76,11 @@
 
     // operational functions
 
-    path absolute(const path& p, const path& base=current_path());
+    path absolute(const path& p);
+    path absolute(const path& p, error_code &ec);
 
-    path canonical(const path& p, const path& base = current_path());
+    path canonical(const path& p);
     path canonical(const path& p, error_code& ec);
-    path canonical(const path& p, const path& base, error_code& ec);
 
     void copy(const path& from, const path& to);
     void copy(const path& from, const path& to, error_code& ec);
@@ -87,2054 +89,169 @@
                    error_code& ec);
 
     bool copy_file(const path& from, const path& to);
-    bool copy_file(const path& from, const path& to, error_code& ec) _NOEXCEPT;
+    bool copy_file(const path& from, const path& to, error_code& ec);
     bool copy_file(const path& from, const path& to, copy_options option);
     bool copy_file(const path& from, const path& to, copy_options option,
-                           error_code& ec) _NOEXCEPT;
+                           error_code& ec);
 
     void copy_symlink(const path& existing_symlink, const path& new_symlink);
     void copy_symlink(const path& existing_symlink, const path& new_symlink,
-                              error_code& ec) _NOEXCEPT;
+                              error_code& ec) noexcept;
 
     bool create_directories(const path& p);
-    bool create_directories(const path& p, error_code& ec) _NOEXCEPT;
+    bool create_directories(const path& p, error_code& ec);
 
     bool create_directory(const path& p);
-    bool create_directory(const path& p, error_code& ec) _NOEXCEPT;
+    bool create_directory(const path& p, error_code& ec) noexcept;
 
     bool create_directory(const path& p, const path& attributes);
     bool create_directory(const path& p, const path& attributes,
-                                  error_code& ec) _NOEXCEPT;
+                                  error_code& ec) noexcept;
 
     void create_directory_symlink(const path& to, const path& new_symlink);
     void create_directory_symlink(const path& to, const path& new_symlink,
-                                          error_code& ec) _NOEXCEPT;
+                                          error_code& ec) noexcept;
 
     void create_hard_link(const path& to, const path& new_hard_link);
     void create_hard_link(const path& to, const path& new_hard_link,
-                                  error_code& ec) _NOEXCEPT;
+                                  error_code& ec) noexcept;
 
     void create_symlink(const path& to, const path& new_symlink);
     void create_symlink(const path& to, const path& new_symlink,
-                                error_code& ec) _NOEXCEPT;
+                                error_code& ec) noexcept;
 
     path current_path();
     path current_path(error_code& ec);
     void current_path(const path& p);
-    void current_path(const path& p, error_code& ec) _NOEXCEPT;
+    void current_path(const path& p, error_code& ec) noexcept;
 
-    bool exists(file_status s) _NOEXCEPT;
+    bool exists(file_status s) noexcept;
     bool exists(const path& p);
-    bool exists(const path& p, error_code& ec) _NOEXCEPT;
+    bool exists(const path& p, error_code& ec) noexcept;
 
     bool equivalent(const path& p1, const path& p2);
-    bool equivalent(const path& p1, const path& p2, error_code& ec) _NOEXCEPT;
+    bool equivalent(const path& p1, const path& p2, error_code& ec) noexcept;
 
     uintmax_t    file_size(const path& p);
-    uintmax_t    file_size(const path& p, error_code& ec) _NOEXCEPT;
+    uintmax_t    file_size(const path& p, error_code& ec) noexcept;
 
     uintmax_t    hard_link_count(const path& p);
-    uintmax_t    hard_link_count(const path& p, error_code& ec) _NOEXCEPT;
+    uintmax_t    hard_link_count(const path& p, error_code& ec) noexcept;
 
-    bool is_block_file(file_status s) _NOEXCEPT;
+    bool is_block_file(file_status s) noexcept;
     bool is_block_file(const path& p);
-    bool is_block_file(const path& p, error_code& ec) _NOEXCEPT;
+    bool is_block_file(const path& p, error_code& ec) noexcept;
 
-    bool is_character_file(file_status s) _NOEXCEPT;
+    bool is_character_file(file_status s) noexcept;
     bool is_character_file(const path& p);
-    bool is_character_file(const path& p, error_code& ec) _NOEXCEPT;
+    bool is_character_file(const path& p, error_code& ec) noexcept;
 
-    bool is_directory(file_status s) _NOEXCEPT;
+    bool is_directory(file_status s) noexcept;
     bool is_directory(const path& p);
-    bool is_directory(const path& p, error_code& ec) _NOEXCEPT;
+    bool is_directory(const path& p, error_code& ec) noexcept;
 
     bool is_empty(const path& p);
-    bool is_empty(const path& p, error_code& ec) _NOEXCEPT;
+    bool is_empty(const path& p, error_code& ec) noexcept;
 
-    bool is_fifo(file_status s) _NOEXCEPT;
+    bool is_fifo(file_status s) noexcept;
     bool is_fifo(const path& p);
-    bool is_fifo(const path& p, error_code& ec) _NOEXCEPT;
+    bool is_fifo(const path& p, error_code& ec) noexcept;
 
-    bool is_other(file_status s) _NOEXCEPT;
+    bool is_other(file_status s) noexcept;
     bool is_other(const path& p);
-    bool is_other(const path& p, error_code& ec) _NOEXCEPT;
+    bool is_other(const path& p, error_code& ec) noexcept;
 
-    bool is_regular_file(file_status s) _NOEXCEPT;
+    bool is_regular_file(file_status s) noexcept;
     bool is_regular_file(const path& p);
-    bool is_regular_file(const path& p, error_code& ec) _NOEXCEPT;
+    bool is_regular_file(const path& p, error_code& ec) noexcept;
 
-    bool is_socket(file_status s) _NOEXCEPT;
+    bool is_socket(file_status s) noexcept;
     bool is_socket(const path& p);
-    bool is_socket(const path& p, error_code& ec) _NOEXCEPT;
+    bool is_socket(const path& p, error_code& ec) noexcept;
 
-    bool is_symlink(file_status s) _NOEXCEPT;
+    bool is_symlink(file_status s) noexcept;
     bool is_symlink(const path& p);
-    bool is_symlink(const path& p, error_code& ec) _NOEXCEPT;
+    bool is_symlink(const path& p, error_code& ec) noexcept;
 
     file_time_type  last_write_time(const path& p);
-    file_time_type  last_write_time(const path& p, error_code& ec) _NOEXCEPT;
+    file_time_type  last_write_time(const path& p, error_code& ec) noexcept;
     void last_write_time(const path& p, file_time_type new_time);
     void last_write_time(const path& p, file_time_type new_time,
-                                 error_code& ec) _NOEXCEPT;
+                                 error_code& ec) noexcept;
 
-    void permissions(const path& p, perms prms);
-    void permissions(const path& p, perms prms, error_code& ec) _NOEXCEPT;
+    void permissions(const path& p, perms prms,
+                     perm_options opts=perm_options::replace);
+    void permissions(const path& p, perms prms, error_code& ec) noexcept;
+    void permissions(const path& p, perms prms, perm_options opts,
+                     error_code& ec);
+
+    path proximate(const path& p, error_code& ec);
+    path proximate(const path& p, const path& base = current_path());
+    path proximate(const path& p, const path& base, error_code &ec);
 
     path read_symlink(const path& p);
     path read_symlink(const path& p, error_code& ec);
 
+    path relative(const path& p, error_code& ec);
+    path relative(const path& p, const path& base=current_path());
+    path relative(const path& p, const path& base, error_code& ec);
+
     bool remove(const path& p);
-    bool remove(const path& p, error_code& ec) _NOEXCEPT;
+    bool remove(const path& p, error_code& ec) noexcept;
 
     uintmax_t    remove_all(const path& p);
-    uintmax_t    remove_all(const path& p, error_code& ec) _NOEXCEPT;
+    uintmax_t    remove_all(const path& p, error_code& ec);
 
     void rename(const path& from, const path& to);
-    void rename(const path& from, const path& to, error_code& ec) _NOEXCEPT;
+    void rename(const path& from, const path& to, error_code& ec) noexcept;
 
     void resize_file(const path& p, uintmax_t size);
-    void resize_file(const path& p, uintmax_t size, error_code& ec) _NOEXCEPT;
+    void resize_file(const path& p, uintmax_t size, error_code& ec) noexcept;
 
     space_info   space(const path& p);
-    space_info   space(const path& p, error_code& ec) _NOEXCEPT;
+    space_info   space(const path& p, error_code& ec) noexcept;
 
     file_status  status(const path& p);
-    file_status  status(const path& p, error_code& ec) _NOEXCEPT;
+    file_status  status(const path& p, error_code& ec) noexcept;
 
-    bool status_known(file_status s) _NOEXCEPT;
+    bool status_known(file_status s) noexcept;
 
     file_status  symlink_status(const path& p);
-    file_status  symlink_status(const path& p, error_code& ec) _NOEXCEPT;
-
-    path system_complete(const path& p);
-    path system_complete(const path& p, error_code& ec);
+    file_status  symlink_status(const path& p, error_code& ec) noexcept;
 
     path temp_directory_path();
     path temp_directory_path(error_code& ec);
 
+    path weakly_canonical(path const& p);
+    path weakly_canonical(path const& p, error_code& ec);
+
+
 } } } }  // namespaces std::experimental::filesystem::v1
 
 */
 
 #include <experimental/__config>
-#include <cstddef>
-#include <chrono>
-#include <iterator>
-#include <iosfwd>
-#include <locale>
-#include <memory>
-#include <stack>
-#include <string>
-#include <system_error>
-#include <utility>
-#include <iomanip> // for quoted
-#include <string_view>
-
-#include <__debug>
+#include <filesystem>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif
 
+_LIBCPP_PUSH_MACROS
+#include <__undef_macros>
+
+#ifndef _LIBCPP_CXX03_LANG
+
 #define __cpp_lib_experimental_filesystem 201406
 
 _LIBCPP_BEGIN_NAMESPACE_EXPERIMENTAL_FILESYSTEM
 
-typedef chrono::time_point<std::chrono::system_clock>  file_time_type;
-
-struct _LIBCPP_TYPE_VIS space_info
-{
-  uintmax_t capacity;
-  uintmax_t free;
-  uintmax_t available;
-};
-
-enum class _LIBCPP_ENUM_VIS file_type : signed char
-{
-    none       = 0,
-    not_found  = -1,
-    regular    = 1,
-    directory  = 2,
-    symlink    = 3,
-    block      = 4,
-    character  = 5,
-    fifo       = 6,
-    socket     = 7,
-    unknown    = 8
-};
-
-enum class _LIBCPP_ENUM_VIS perms : unsigned
-{
-    none         = 0,
-
-    owner_read   = 0400,
-    owner_write  = 0200,
-    owner_exec   = 0100,
-    owner_all    = 0700,
-
-    group_read   = 040,
-    group_write  = 020,
-    group_exec   = 010,
-    group_all    = 070,
-
-    others_read  = 04,
-    others_write = 02,
-    others_exec  = 01,
-    others_all   = 07,
-
-    all          = 0777,
-
-    set_uid      = 04000,
-    set_gid      = 02000,
-    sticky_bit   = 01000,
-    mask         = 07777,
-    unknown      = 0xFFFF,
-
-    add_perms        = 0x10000,
-    remove_perms     = 0x20000,
-    symlink_nofollow = 0x40000
-};
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR perms operator&(perms _LHS, perms _RHS)
-{ return static_cast<perms>(static_cast<unsigned>(_LHS) & static_cast<unsigned>(_RHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR perms operator|(perms _LHS, perms _RHS)
-{ return static_cast<perms>(static_cast<unsigned>(_LHS) | static_cast<unsigned>(_RHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR perms operator^(perms _LHS, perms _RHS)
-{ return static_cast<perms>(static_cast<unsigned>(_LHS) ^ static_cast<unsigned>(_RHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR perms operator~(perms _LHS)
-{ return static_cast<perms>(~static_cast<unsigned>(_LHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline perms& operator&=(perms& _LHS, perms _RHS)
-{ return _LHS = _LHS & _RHS; }
-
-_LIBCPP_INLINE_VISIBILITY
-inline perms& operator|=(perms& _LHS, perms _RHS)
-{ return _LHS = _LHS | _RHS; }
-
-_LIBCPP_INLINE_VISIBILITY
-inline perms& operator^=(perms& _LHS, perms _RHS)
-{ return _LHS = _LHS ^ _RHS; }
-
-enum class _LIBCPP_ENUM_VIS copy_options : unsigned short
-{
-    none               = 0,
-    skip_existing      = 1,
-    overwrite_existing = 2,
-    update_existing    = 4,
-    recursive          = 8,
-    copy_symlinks      = 16,
-    skip_symlinks      = 32,
-    directories_only   = 64,
-    create_symlinks    = 128,
-    create_hard_links  = 256,
-    __in_recursive_copy = 512,
-};
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR copy_options operator&(copy_options _LHS, copy_options _RHS)
-{ return static_cast<copy_options>(static_cast<unsigned short>(_LHS) & static_cast<unsigned short>(_RHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR copy_options operator|(copy_options _LHS, copy_options _RHS)
-{ return static_cast<copy_options>(static_cast<unsigned short>(_LHS) | static_cast<unsigned short>(_RHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR copy_options operator^(copy_options _LHS, copy_options _RHS)
-{ return static_cast<copy_options>(static_cast<unsigned short>(_LHS) ^ static_cast<unsigned short>(_RHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR copy_options operator~(copy_options _LHS)
-{ return static_cast<copy_options>(~static_cast<unsigned short>(_LHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline copy_options& operator&=(copy_options& _LHS, copy_options _RHS)
-{ return _LHS = _LHS & _RHS; }
-
-_LIBCPP_INLINE_VISIBILITY
-inline copy_options& operator|=(copy_options& _LHS, copy_options _RHS)
-{ return _LHS = _LHS | _RHS; }
-
-_LIBCPP_INLINE_VISIBILITY
-inline copy_options& operator^=(copy_options& _LHS, copy_options _RHS)
-{ return _LHS = _LHS ^ _RHS; }
-
-
-enum class _LIBCPP_ENUM_VIS directory_options : unsigned char
-{
-    none                     = 0,
-    follow_directory_symlink = 1,
-    skip_permission_denied   = 2
-};
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR directory_options operator&(directory_options _LHS, directory_options _RHS)
-{ return static_cast<directory_options>(static_cast<unsigned char>(_LHS) & static_cast<unsigned char>(_RHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR directory_options operator|(directory_options _LHS, directory_options _RHS)
-{ return static_cast<directory_options>(static_cast<unsigned char>(_LHS) | static_cast<unsigned char>(_RHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR directory_options operator^(directory_options _LHS, directory_options _RHS)
-{ return static_cast<directory_options>(static_cast<unsigned char>(_LHS) ^ static_cast<unsigned char>(_RHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline _LIBCPP_CONSTEXPR directory_options operator~(directory_options _LHS)
-{ return static_cast<directory_options>(~static_cast<unsigned char>(_LHS)); }
-
-_LIBCPP_INLINE_VISIBILITY
-inline directory_options& operator&=(directory_options& _LHS, directory_options _RHS)
-{ return _LHS = _LHS & _RHS; }
-
-_LIBCPP_INLINE_VISIBILITY
-inline directory_options& operator|=(directory_options& _LHS, directory_options _RHS)
-{ return _LHS = _LHS | _RHS; }
-
-_LIBCPP_INLINE_VISIBILITY
-inline directory_options& operator^=(directory_options& _LHS, directory_options _RHS)
-{ return _LHS = _LHS ^ _RHS; }
-
-
-class _LIBCPP_TYPE_VIS file_status
-{
-public:
-    // constructors
-    _LIBCPP_INLINE_VISIBILITY
-    file_status() _NOEXCEPT : file_status(file_type::none) {}
-    _LIBCPP_INLINE_VISIBILITY
-    explicit file_status(file_type __ft,
-                         perms __prms = perms::unknown) _NOEXCEPT
-      : __ft_(__ft), __prms_(__prms)
-    {}
-
-    file_status(const file_status&) _NOEXCEPT = default;
-    file_status(file_status&&) _NOEXCEPT = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~file_status() {}
-
-    file_status& operator=(const file_status&) _NOEXCEPT = default;
-    file_status& operator=(file_status&&) _NOEXCEPT = default;
-
-    // observers
-    _LIBCPP_ALWAYS_INLINE
-    file_type type() const _NOEXCEPT {
-        return __ft_;
-    }
-
-    _LIBCPP_ALWAYS_INLINE
-    perms permissions() const _NOEXCEPT {
-        return __prms_;
-    }
-
-    // modifiers
-    _LIBCPP_ALWAYS_INLINE
-    void type(file_type __ft) _NOEXCEPT {
-        __ft_ = __ft;
-    }
-
-    _LIBCPP_ALWAYS_INLINE
-    void permissions(perms __p) _NOEXCEPT {
-        __prms_ = __p;
-    }
-private:
-    file_type __ft_;
-    perms __prms_;
-};
-
-class _LIBCPP_TYPE_VIS directory_entry;
-
-template <class _Tp> struct __can_convert_char {
-  static const bool value = false;
-};
-template <class _Tp> struct __can_convert_char<const _Tp>
-    : public __can_convert_char<_Tp> {
-};
-template <> struct __can_convert_char<char> {
-    static const bool value = true;
-    using __char_type = char;
-};
-template <> struct __can_convert_char<wchar_t>  {
-    static const bool value = true;
-    using __char_type = wchar_t;
-};
-template <> struct __can_convert_char<char16_t> {
-    static const bool value = true;
-    using __char_type = char16_t;
-};
-template <> struct __can_convert_char<char32_t> {
-    static const bool value = true;
-    using __char_type = char32_t;
-};
-
-template <class _ECharT>
-typename enable_if<__can_convert_char<_ECharT>::value, bool>::type
-__is_separator(_ECharT __e) {
-    return __e == _ECharT('/');
-};
-
-struct _NullSentinal {};
-
-template <class _Tp>
-using _Void = void;
-
-template <class _Tp, class = void>
-struct __is_pathable_string : public false_type {};
-
-template <class _ECharT, class _Traits, class _Alloc>
-struct __is_pathable_string<basic_string<_ECharT, _Traits, _Alloc>,
-                            _Void<typename __can_convert_char<_ECharT>::__char_type>>
-: public __can_convert_char<_ECharT>
-{
-    using _Str = basic_string<_ECharT, _Traits, _Alloc>;
-    using _Base = __can_convert_char<_ECharT>;
-    static _ECharT const* __range_begin(_Str const& __s) { return __s.data(); }
-    static _ECharT const* __range_end(_Str const& __s) { return __s.data() + __s.length(); }
-    static _ECharT __first_or_null(_Str const& __s) {
-        return __s.empty() ? _ECharT{} : __s[0];
-    }
-};
-
-
-template <class _ECharT, class _Traits>
-struct __is_pathable_string<basic_string_view<_ECharT, _Traits>,
-                            _Void<typename __can_convert_char<_ECharT>::__char_type>>
-: public __can_convert_char<_ECharT>
-{
-    using _Str = basic_string_view<_ECharT, _Traits>;
-    using _Base = __can_convert_char<_ECharT>;
-    static _ECharT const* __range_begin(_Str const& __s) { return __s.data(); }
-    static _ECharT const* __range_end(_Str const& __s) { return __s.data() + __s.length(); }
-    static _ECharT __first_or_null(_Str const& __s) {
-        return __s.empty() ? _ECharT{} : __s[0];
-    }
-};
-
-template <class _Source,
-          class _DS = typename decay<_Source>::type,
-          class _UnqualPtrType = typename remove_const<
-              typename remove_pointer<_DS>::type>::type,
-          bool _IsCharPtr = is_pointer<_DS>::value &&
-                            __can_convert_char<_UnqualPtrType>::value
-        >
-struct __is_pathable_char_array : false_type {};
-
-template <class _Source, class _ECharT, class _UPtr>
-struct __is_pathable_char_array<_Source, _ECharT*, _UPtr, true>
-        : __can_convert_char<typename remove_const<_ECharT>::type>
-{
-  using _Base = __can_convert_char<typename remove_const<_ECharT>::type>;
-
-  static _ECharT const* __range_begin(const _ECharT* __b) { return __b; }
-  static _ECharT const* __range_end(const _ECharT* __b)
-  {
-      using _Iter = const _ECharT*;
-      const _ECharT __sentinal = _ECharT{};
-      _Iter __e = __b;
-      for (; *__e != __sentinal; ++__e)
-          ;
-      return __e;
-  }
-
-  static _ECharT __first_or_null(const _ECharT* __b) { return *__b; }
-};
-
-template <class _Iter, bool _IsIt = __is_input_iterator<_Iter>::value, class = void>
-struct __is_pathable_iter : false_type {};
-
-template <class _Iter>
-struct __is_pathable_iter<_Iter, true,
-        _Void<typename __can_convert_char<typename iterator_traits<_Iter>::value_type>::__char_type>>
-        : __can_convert_char<typename iterator_traits<_Iter>::value_type>
-{
-  using _ECharT = typename iterator_traits<_Iter>::value_type;
-  using _Base = __can_convert_char<_ECharT>;
-
-  static _Iter         __range_begin(_Iter __b) { return __b; }
-  static _NullSentinal __range_end(_Iter)       { return _NullSentinal{}; }
-
-  static _ECharT __first_or_null(_Iter __b) { return *__b; }
-};
-
-template <class _Tp, bool _IsStringT =  __is_pathable_string<_Tp>::value,
-                     bool _IsCharIterT = __is_pathable_char_array<_Tp>::value,
-                     bool _IsIterT = !_IsCharIterT && __is_pathable_iter<_Tp>::value
-         >
-struct __is_pathable : false_type {
-  static_assert(!_IsStringT && !_IsCharIterT && !_IsIterT, "Must all be false");
-};
-
-template <class _Tp>
-struct __is_pathable<_Tp, true, false, false> : __is_pathable_string<_Tp> {};
-
-
-template <class _Tp>
-struct __is_pathable<_Tp, false, true, false> : __is_pathable_char_array<_Tp> {};
-
-
-template <class _Tp>
-struct __is_pathable<_Tp, false, false, true> : __is_pathable_iter<_Tp> {};
-
-
-template <class _ECharT>
-struct _PathCVT {
-    static_assert(__can_convert_char<_ECharT>::value, "Char type not convertible");
-
-    typedef __narrow_to_utf8<sizeof(_ECharT)*__CHAR_BIT__> _Narrower;
-
-    static void __append_range(string& __dest, _ECharT const* __b, _ECharT const* __e)  {
-        _Narrower()(back_inserter(__dest), __b, __e);
-    }
-
-    template <class _Iter>
-    static void __append_range(string& __dest, _Iter __b, _Iter __e) {
-        static_assert(!is_same<_Iter, _ECharT*>::value, "Call const overload");
-        if (__b == __e) return;
-        basic_string<_ECharT> __tmp(__b, __e);
-        _Narrower()(back_inserter(__dest), __tmp.data(),
-                    __tmp.data() + __tmp.length());
-    }
-
-    template <class _Iter>
-    static void __append_range(string& __dest, _Iter __b, _NullSentinal) {
-        static_assert(!is_same<_Iter, _ECharT*>::value, "Call const overload");
-        const _ECharT __sentinal = _ECharT{};
-        if (*__b == __sentinal) return;
-        basic_string<_ECharT> __tmp;
-        for (; *__b != __sentinal; ++__b)
-            __tmp.push_back(*__b);
-        _Narrower()(back_inserter(__dest), __tmp.data(),
-                    __tmp.data() + __tmp.length());
-    }
-
-    template <class _Source>
-    static void __append_source(string& __dest, _Source const& __s)
-    {
-        using _Traits = __is_pathable<_Source>;
-        __append_range(__dest, _Traits::__range_begin(__s), _Traits::__range_end(__s));
-    }
-};
-
-template <>
-struct _PathCVT<char> {
-
-    template <class _Iter>
-    static typename enable_if<
-        __is_exactly_input_iterator<_Iter>::value
-    >::type __append_range(string& __dest, _Iter __b, _Iter __e) {
-        for (; __b != __e; ++__b)
-            __dest.push_back(*__b);
-    }
-
-    template <class _Iter>
-    static typename enable_if<
-        __is_forward_iterator<_Iter>::value
-    >::type __append_range(string& __dest, _Iter __b, _Iter __e) {
-        __dest.__append_forward_unsafe(__b, __e);
-    }
-
-    template <class _Iter>
-    static void __append_range(string& __dest, _Iter __b, _NullSentinal) {
-        const char __sentinal = char{};
-        for (; *__b != __sentinal; ++__b)
-            __dest.push_back(*__b);
-    }
-
-    template <class _Source>
-    static void __append_source(string& __dest, _Source const& __s)
-    {
-        using _Traits = __is_pathable<_Source>;
-        __append_range(__dest, _Traits::__range_begin(__s),
-                               _Traits::__range_end(__s));
-    }
-};
-
-
-class _LIBCPP_TYPE_VIS path
-{
-    template <class _SourceOrIter, class _Tp = path&>
-    using _EnableIfPathable = typename
-        enable_if<__is_pathable<_SourceOrIter>::value, _Tp>::type;
-
-    template <class _Tp>
-    using _SourceChar = typename __is_pathable<_Tp>::__char_type;
-
-    template <class _Tp>
-    using _SourceCVT = _PathCVT<_SourceChar<_Tp>>;
-
-public:
-    typedef char value_type;
-    typedef basic_string<value_type> string_type;
-    typedef _VSTD::string_view __string_view;
-    static _LIBCPP_CONSTEXPR value_type preferred_separator = '/';
-
-    // constructors and destructor
-    _LIBCPP_INLINE_VISIBILITY path() _NOEXCEPT {}
-    _LIBCPP_INLINE_VISIBILITY path(const path& __p)      : __pn_(__p.__pn_) {}
-    _LIBCPP_INLINE_VISIBILITY path(path&& __p) _NOEXCEPT : __pn_(_VSTD::move(__p.__pn_)) {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    path(string_type&& __s) _NOEXCEPT : __pn_(_VSTD::move(__s)) {}
-
-    template <
-        class _Source,
-        class = _EnableIfPathable<_Source, void>
-        >
-    path(const _Source& __src) {
-        _SourceCVT<_Source>::__append_source(__pn_, __src);
-    }
-
-    template <class _InputIt>
-    path(_InputIt __first, _InputIt __last) {
-        typedef typename iterator_traits<_InputIt>::value_type _ItVal;
-        _PathCVT<_ItVal>::__append_range(__pn_, __first, __last);
-    }
-
-    // TODO Implement locale conversions.
-    template <class _Source,
-              class = _EnableIfPathable<_Source, void>
-             >
-        path(const _Source& __src, const locale& __loc);
-    template <class _InputIt>
-        path(_InputIt __first, _InputIt _last, const locale& __loc);
-
-    _LIBCPP_INLINE_VISIBILITY
-    ~path() = default;
-
-    // assignments
-    _LIBCPP_INLINE_VISIBILITY
-    path& operator=(const path& __p) {
-        __pn_ = __p.__pn_;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    path& operator=(path&& __p) _NOEXCEPT {
-        __pn_ = _VSTD::move(__p.__pn_);
-        return *this;
-    }
-
-    template <class = void>
-    _LIBCPP_INLINE_VISIBILITY
-    path& operator=(string_type&& __s) _NOEXCEPT {
-        __pn_ = _VSTD::move(__s);
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    path& assign(string_type&& __s) _NOEXCEPT {
-        __pn_ = _VSTD::move(__s);
-        return *this;
-    }
-
-    template <class _Source>
-    _LIBCPP_INLINE_VISIBILITY
-    _EnableIfPathable<_Source>
-    operator=(const _Source& __src)
-    { return this->assign(__src); }
-
-
-    template <class _Source>
-    _EnableIfPathable<_Source>
-    assign(const _Source& __src) {
-        __pn_.clear();
-        _SourceCVT<_Source>::__append_source(__pn_, __src);
-        return *this;
-    }
-
-    template <class _InputIt>
-    path& assign(_InputIt __first, _InputIt __last) {
-        typedef typename iterator_traits<_InputIt>::value_type _ItVal;
-        __pn_.clear();
-        _PathCVT<_ItVal>::__append_range(__pn_, __first, __last);
-        return *this;
-    }
-
-private:
-    template <class _ECharT>
-    void __append_sep_if_needed(_ECharT __first_or_null) {
-        const _ECharT __null_val = {};
-        bool __append_sep = !empty()                       &&
-                            !__is_separator(__pn_.back())  &&
-                            __first_or_null != __null_val  && // non-empty
-                            !__is_separator(__first_or_null);
-        if (__append_sep)
-            __pn_ += preferred_separator;
-    }
-
-public:
-    // appends
-    path& operator/=(const path& __p) {
-        _LIBCPP_ASSERT(!__p.has_root_name(),
-                      "cannot append to a path with a root name");
-        __append_sep_if_needed(__p.empty() ? char{} : __p.__pn_[0]);
-        __pn_ += __p.native();
-        return *this;
-    }
-
-    template <class _Source>
-    _LIBCPP_INLINE_VISIBILITY
-    _EnableIfPathable<_Source>
-    operator/=(const _Source& __src) {
-        return this->append(__src);
-    }
-
-    template <class _Source>
-    _EnableIfPathable<_Source>
-    append(const _Source& __src) {
-        using _Traits = __is_pathable<_Source>;
-        using _CVT = _PathCVT<_SourceChar<_Source>>;
-        __append_sep_if_needed(_Traits::__first_or_null(__src));
-        _CVT::__append_source(__pn_, __src);
-        return *this;
-    }
-
-    template <class _InputIt>
-    path& append(_InputIt __first, _InputIt __last) {
-        typedef typename iterator_traits<_InputIt>::value_type _ItVal;
-        static_assert(__can_convert_char<_ItVal>::value, "Must convertible");
-        using _CVT = _PathCVT<_ItVal>;
-        if (__first != __last) {
-            __append_sep_if_needed(*__first);
-            _CVT::__append_range(__pn_, __first, __last);
-        }
-        return *this;
-    }
-
-    // concatenation
-    _LIBCPP_INLINE_VISIBILITY
-    path& operator+=(const path& __x) {
-        __pn_ += __x.__pn_;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    path& operator+=(const string_type& __x) {
-        __pn_ += __x;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    path& operator+=(__string_view __x) {
-        __pn_ += __x;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    path& operator+=(const value_type* __x) {
-        __pn_ += __x;
-        return *this;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    path& operator+=(value_type __x) {
-        __pn_ += __x;
-        return *this;
-    }
-
-    template <class _ECharT>
-    typename enable_if<__can_convert_char<_ECharT>::value, path&>::type
-    operator+=(_ECharT __x)
-    {
-        basic_string<_ECharT> __tmp;
-        __tmp += __x;
-        _PathCVT<_ECharT>::__append_source(__pn_, __tmp);
-        return *this;
-    }
-
-    template <class _Source>
-    _EnableIfPathable<_Source>
-    operator+=(const _Source& __x) {
-       return this->concat(__x);
-    }
-
-    template <class _Source>
-    _EnableIfPathable<_Source>
-    concat(const _Source& __x) {
-         _SourceCVT<_Source>::__append_source(__pn_, __x);
-        return *this;
-    }
-
-    template <class _InputIt>
-    path& concat(_InputIt __first, _InputIt __last) {
-        typedef typename iterator_traits<_InputIt>::value_type _ItVal;
-        _PathCVT<_ItVal>::__append_range(__pn_, __first, __last);
-        return *this;
-    }
-
-    // modifiers
-    _LIBCPP_INLINE_VISIBILITY
-    void clear() _NOEXCEPT {
-        __pn_.clear();
-    }
-
-    path& make_preferred() { return *this; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    path& remove_filename() {
-      if (__pn_.size() == __root_path_raw().size())
-        clear();
-      else
-        __pn_ = __parent_path();
-      return *this;
-    }
-
-    path& replace_filename(const path& __replacement) {
-        remove_filename();
-        return (*this /= __replacement);
-    }
-
-    path& replace_extension(const path& __replacement = path());
-
-    _LIBCPP_INLINE_VISIBILITY
-    void  swap(path& __rhs) _NOEXCEPT {
-        __pn_.swap(__rhs.__pn_);
-    }
-
-    // native format observers
-    _LIBCPP_INLINE_VISIBILITY
-    const string_type& native() const _NOEXCEPT {
-        return __pn_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const value_type* c_str() const _NOEXCEPT { return __pn_.c_str(); }
-
-    _LIBCPP_INLINE_VISIBILITY operator string_type() const { return __pn_;  }
-
-    template <class _ECharT, class _Traits = char_traits<_ECharT>,
-              class _Allocator = allocator<_ECharT> >
-    basic_string<_ECharT, _Traits, _Allocator>
-    string(const _Allocator& __a = _Allocator()) const {
-        using _CVT = __widen_from_utf8<sizeof(_ECharT)*__CHAR_BIT__>;
-        using _Str = basic_string<_ECharT, _Traits, _Allocator>;
-        _Str __s(__a);
-        __s.reserve(__pn_.size());
-        _CVT()(back_inserter(__s), __pn_.data(), __pn_.data() + __pn_.size());
-        return __s;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY std::string    string()    const { return __pn_; }
-    _LIBCPP_INLINE_VISIBILITY std::wstring   wstring()   const { return string<wchar_t>(); }
-    _LIBCPP_INLINE_VISIBILITY std::string    u8string()  const { return __pn_; }
-    _LIBCPP_INLINE_VISIBILITY std::u16string u16string() const { return string<char16_t>(); }
-    _LIBCPP_INLINE_VISIBILITY std::u32string u32string() const { return string<char32_t>(); }
-
-    // generic format observers
-    template <class _ECharT, class _Traits = char_traits<_ECharT>,
-              class _Allocator = allocator<_ECharT>
-    >
-    basic_string<_ECharT, _Traits, _Allocator>
-    generic_string(const _Allocator& __a = _Allocator()) const {
-        return string<_ECharT, _Traits, _Allocator>(__a);
-    }
-
-    std::string    generic_string()    const { return __pn_; }
-    std::wstring   generic_wstring()   const { return string<wchar_t>(); }
-    std::string    generic_u8string()  const { return __pn_; }
-    std::u16string generic_u16string() const { return string<char16_t>(); }
-    std::u32string generic_u32string() const { return string<char32_t>(); }
-
-private:
-    int __compare(__string_view) const;
-    __string_view __root_name() const;
-    __string_view __root_directory() const;
-    __string_view __root_path_raw() const;
-    __string_view __relative_path() const;
-    __string_view __parent_path() const;
-    __string_view __filename() const;
-    __string_view __stem() const;
-    __string_view __extension() const;
-
-public:
-    // compare
-    _LIBCPP_INLINE_VISIBILITY int compare(const path& __p) const _NOEXCEPT { return __compare(__p.__pn_);}
-    _LIBCPP_INLINE_VISIBILITY int compare(const string_type& __s) const { return __compare(__s); }
-    _LIBCPP_INLINE_VISIBILITY int compare(__string_view __s) const { return __compare(__s); }
-    _LIBCPP_INLINE_VISIBILITY int compare(const value_type* __s) const  { return __compare(__s); }
-
-    // decomposition
-    _LIBCPP_INLINE_VISIBILITY path root_name()      const { return  string_type(__root_name()); }
-    _LIBCPP_INLINE_VISIBILITY path root_directory() const { return  string_type(__root_directory()); }
-    _LIBCPP_INLINE_VISIBILITY path root_path()      const { return root_name().append(string_type(__root_directory())); }
-    _LIBCPP_INLINE_VISIBILITY path relative_path()  const { return string_type(__relative_path()); }
-    _LIBCPP_INLINE_VISIBILITY path parent_path()    const { return string_type(__parent_path()); }
-    _LIBCPP_INLINE_VISIBILITY path filename()       const { return string_type(__filename()); }
-    _LIBCPP_INLINE_VISIBILITY path stem()           const { return string_type(__stem());}
-    _LIBCPP_INLINE_VISIBILITY path extension()      const { return string_type(__extension()); }
-
-    // query
-    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY 
-    bool empty() const _NOEXCEPT { return __pn_.empty(); }
-
-    _LIBCPP_INLINE_VISIBILITY bool has_root_name()      const { return !__root_name().empty(); }
-    _LIBCPP_INLINE_VISIBILITY bool has_root_directory() const { return !__root_directory().empty(); }
-    _LIBCPP_INLINE_VISIBILITY bool has_root_path()      const { return !__root_path_raw().empty(); }
-    _LIBCPP_INLINE_VISIBILITY bool has_relative_path()  const { return !__relative_path().empty(); }
-    _LIBCPP_INLINE_VISIBILITY bool has_parent_path()    const { return !__parent_path().empty(); }
-    _LIBCPP_INLINE_VISIBILITY bool has_filename()       const { return !__filename().empty(); }
-    _LIBCPP_INLINE_VISIBILITY bool has_stem()           const { return !__stem().empty(); }
-    _LIBCPP_INLINE_VISIBILITY bool has_extension()      const { return !__extension().empty(); }
-
-    _LIBCPP_INLINE_VISIBILITY bool is_absolute()        const { return has_root_directory(); }
-    _LIBCPP_INLINE_VISIBILITY bool is_relative()        const { return !is_absolute(); }
-
-    // iterators
-    class _LIBCPP_TYPE_VIS iterator;
-    typedef iterator const_iterator;
-
-    iterator begin() const;
-    iterator end() const;
-
-private:
-    inline _LIBCPP_INLINE_VISIBILITY
-    path& __assign_view(__string_view const& __s) noexcept { __pn_ = string_type(__s); return *this; }
-    string_type __pn_;
-};
-
-inline _LIBCPP_ALWAYS_INLINE
-void swap(path& __lhs, path& __rhs) _NOEXCEPT {
-    __lhs.swap(__rhs);
-}
-
-_LIBCPP_FUNC_VIS
-size_t hash_value(const path& __p) _NOEXCEPT;
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(const path& __lhs, const path& __rhs) _NOEXCEPT
-{ return __lhs.compare(__rhs) == 0; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(const path& __lhs, const path& __rhs) _NOEXCEPT
-{ return __lhs.compare(__rhs) != 0; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator<(const path& __lhs, const path& __rhs) _NOEXCEPT
-{ return __lhs.compare(__rhs) < 0; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator<=(const path& __lhs, const path& __rhs) _NOEXCEPT
-{ return __lhs.compare(__rhs) <= 0; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator>(const path& __lhs, const path& __rhs) _NOEXCEPT
-{ return __lhs.compare(__rhs) > 0; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator>=(const path& __lhs, const path& __rhs) _NOEXCEPT
-{ return __lhs.compare(__rhs) >= 0; }
-
-inline _LIBCPP_INLINE_VISIBILITY
-path operator/(const path& __lhs, const path& __rhs) {
-    return path(__lhs) /= __rhs;
-}
-
-template <class _CharT, class _Traits>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if<is_same<_CharT, char>::value &&
-                   is_same<_Traits, char_traits<char>>::value,
-                   basic_ostream<_CharT, _Traits>&
->::type
-operator<<(basic_ostream<_CharT, _Traits>& __os, const path& __p) {
-    __os << std::__quoted(__p.native());
-    return __os;
-}
-
-template <class _CharT, class _Traits>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if<!is_same<_CharT, char>::value ||
-                   !is_same<_Traits, char_traits<char>>::value,
-                   basic_ostream<_CharT, _Traits>&
->::type
-operator<<(basic_ostream<_CharT, _Traits>& __os, const path& __p) {
-    __os << std::__quoted(__p.string<_CharT, _Traits>());
-    return __os;
-}
-
-template <class _CharT, class _Traits>
-_LIBCPP_INLINE_VISIBILITY
-basic_istream<_CharT, _Traits>&
-operator>>(basic_istream<_CharT, _Traits>& __is, path& __p)
-{
-    basic_string<_CharT, _Traits> __tmp;
-    __is >> __quoted(__tmp);
-    __p = __tmp;
-    return __is;
-}
-
-template <class _Source>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if<__is_pathable<_Source>::value, path>::type
-u8path(const _Source& __s){
-    static_assert(is_same<typename __is_pathable<_Source>::__char_type, char>::value,
-        "u8path(Source const&) requires Source have a character type of type 'char'");
-    return path(__s);
-}
-
-template <class _InputIt>
-_LIBCPP_INLINE_VISIBILITY
-typename enable_if<__is_pathable<_InputIt>::value, path>::type
-u8path(_InputIt __f, _InputIt __l) {
-    static_assert(is_same<typename __is_pathable<_InputIt>::__char_type, char>::value,
-        "u8path(Iter, Iter) requires Iter have a value_type of type 'char'");
-    return path(__f, __l);
-}
-
-class _LIBCPP_TYPE_VIS path::iterator
-{
-public:
-    typedef bidirectional_iterator_tag iterator_category;
-
-    typedef path                       value_type;
-    typedef std::ptrdiff_t             difference_type;
-    typedef const path*                pointer;
-    typedef const path&                reference;
-
-    typedef void __stashing_iterator_tag; // See reverse_iterator and __is_stashing_iterator
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    iterator() : __stashed_elem_(), __path_ptr_(nullptr),
-                 __entry_(), __state_(__singular) {}
-
-    iterator(const iterator&) = default;
-    ~iterator() = default;
-
-    iterator& operator=(const iterator&) = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    reference operator*() const {
-        return __stashed_elem_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    pointer operator->() const {
-        return &__stashed_elem_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator& operator++() {
-        _LIBCPP_ASSERT(__state_ != __singular,
-                       "attempting to increment a singular iterator");
-        _LIBCPP_ASSERT(__state_ != __at_end,
-                      "attempting to increment the end iterator");
-        return __increment();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator operator++(int) {
-        iterator __it(*this);
-        this->operator++();
-        return __it;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator& operator--() {
-        _LIBCPP_ASSERT(__state_ != __singular,
-                       "attempting to decrement a singular iterator");
-        _LIBCPP_ASSERT(__entry_.data() != __path_ptr_->native().data(),
-                       "attempting to decrement the begin iterator");
-        return __decrement();
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    iterator operator--(int) {
-        iterator __it(*this);
-        this->operator--();
-        return __it;
-    }
-
-private:
-    friend class path;
-
-    static constexpr unsigned char __singular = 0;
-    static constexpr unsigned char __at_end = 6;
-
-    inline _LIBCPP_INLINE_VISIBILITY
-    friend bool operator==(const iterator&, const iterator&);
-
-    iterator& __increment();
-    iterator& __decrement();
-
-    path __stashed_elem_;
-    const path* __path_ptr_;
-    path::__string_view __entry_;
-    unsigned char __state_;
-};
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(const path::iterator& __lhs, const path::iterator& __rhs) {
-    return __lhs.__path_ptr_ == __rhs.__path_ptr_ &&
-           __lhs.__entry_.data() == __rhs.__entry_.data();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(const path::iterator& __lhs, const path::iterator& __rhs) {
-    return !(__lhs == __rhs);
-}
-
-class _LIBCPP_EXCEPTION_ABI filesystem_error : public system_error
-{
-public:
-    _LIBCPP_INLINE_VISIBILITY
-    filesystem_error(const string& __what, error_code __ec)
-        : system_error(__ec, __what),
-          __paths_(make_shared<_Storage>(path(), path()))
-    {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    filesystem_error(const string& __what, const path& __p1, error_code __ec)
-        : system_error(__ec, __what),
-        __paths_(make_shared<_Storage>(__p1, path()))
-    {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    filesystem_error(const string& __what, const path& __p1, const path& __p2,
-                     error_code __ec)
-        : system_error(__ec, __what),
-          __paths_(make_shared<_Storage>(__p1, __p2))
-    {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    const path& path1() const _NOEXCEPT {
-        return __paths_->first;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const path& path2() const _NOEXCEPT {
-        return __paths_->second;
-    }
-
-    ~filesystem_error() override; // key function
-
-    // TODO(ericwf): Create a custom error message.
-    //const char* what() const _NOEXCEPT;
-
-private:
-    typedef pair<path, path> _Storage;
-    shared_ptr<_Storage> __paths_;
-};
-
-template <class... _Args>
-_LIBCPP_NORETURN inline _LIBCPP_ALWAYS_INLINE
-#ifndef _LIBCPP_NO_EXCEPTIONS
-void __throw_filesystem_error(_Args && ...__args)
-{
-    throw filesystem_error(std::forward<_Args>(__args)...);
-}
-#else
-void __throw_filesystem_error(_Args&&...)
-{
-    _VSTD::abort();
-}
-#endif
+using namespace _VSTD_FS;
 
+_LIBCPP_END_NAMESPACE_EXPERIMENTAL_FILESYSTEM
 
-// operational functions
-
-_LIBCPP_FUNC_VIS
-path __canonical(const path&, const path&, error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __copy(const path& __from, const path& __to, copy_options __opt,
-        error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-bool __copy_file(const path& __from, const path& __to, copy_options __opt,
-        error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __copy_symlink(const path& __existing_symlink, const path& __new_symlink,
-        error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-bool __create_directories(const path& p, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-bool __create_directory(const path& p, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-bool __create_directory(const path& p, const path & attributes,
-        error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __create_directory_symlink(const path& __to, const path& __new_symlink,
-        error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __create_hard_link(const path& __to, const path& __new_hard_link,
-        error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __create_symlink(const path& __to, const path& __new_symlink,
-        error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-path __current_path(error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __current_path(const path&, error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-bool __equivalent(const path&, const path&, error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-uintmax_t __file_size(const path&, error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-uintmax_t __hard_link_count(const path&, error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-bool __fs_is_empty(const path& p, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-file_time_type __last_write_time(const path& p, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __last_write_time(const path& p, file_time_type new_time,
-        error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __permissions(const path& p, perms prms, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-path __read_symlink(const path& p, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-bool __remove(const path& p, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-uintmax_t __remove_all(const path& p, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __rename(const path& from, const path& to, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-void __resize_file(const path& p, uintmax_t size, error_code *ec=nullptr);
-_LIBCPP_FUNC_VIS
-space_info __space(const path&, error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-file_status __status(const path&, error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-file_status __symlink_status(const path&, error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-path __system_complete(const path&, error_code *__ec=nullptr);
-_LIBCPP_FUNC_VIS
-path __temp_directory_path(error_code *__ec=nullptr);
-
-inline _LIBCPP_INLINE_VISIBILITY
-path current_path() {
-    return __current_path();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-path current_path(error_code& __ec) {
-    return __current_path(&__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void current_path(const path& __p) {
-    __current_path(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void current_path(const path& __p, error_code& __ec) _NOEXCEPT {
-    __current_path(__p, &__ec);
-}
-
-_LIBCPP_FUNC_VIS
-path absolute(const path&, const path& __p2 = current_path());
-
-inline _LIBCPP_INLINE_VISIBILITY
-path canonical(const path& __p, const path& __base = current_path()) {
-    return __canonical(__p, __base);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-path canonical(const path& __p, error_code& __ec) {
-    path __base = __current_path(&__ec);
-    if (__ec) return {};
-    return __canonical(__p, __base, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-path canonical(const path& __p, const path& __base, error_code& __ec) {
-    return __canonical(__p, __base, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void copy(const path& __from, const path& __to) {
-    __copy(__from, __to, copy_options::none);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void copy(const path& __from, const path& __to, error_code& __ec) {
-    __copy(__from, __to, copy_options::none, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void copy(const path& __from, const path& __to, copy_options __opt) {
-    __copy(__from, __to, __opt);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void copy(const path& __from, const path& __to,
-          copy_options __opt, error_code& __ec) {
-    __copy(__from, __to, __opt, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool copy_file(const path& __from, const path& __to) {
-    return __copy_file(__from, __to, copy_options::none);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool copy_file(const path& __from, const path& __to, error_code& __ec) _NOEXCEPT {
-    return __copy_file(__from, __to, copy_options::none, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool copy_file(const path& __from, const path& __to, copy_options __opt) {
-    return __copy_file(__from, __to, __opt);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool copy_file(const path& __from, const path& __to,
-               copy_options __opt, error_code& __ec) _NOEXCEPT {
-    return __copy_file(__from, __to, __opt, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void copy_symlink(const path& __existing, const path& __new) {
-    __copy_symlink(__existing, __new);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void copy_symlink(const path& __ext, const path& __new, error_code& __ec) _NOEXCEPT {
-    __copy_symlink(__ext, __new, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool create_directories(const path& __p) {
-    return __create_directories(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool create_directories(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __create_directories(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool create_directory(const path& __p) {
-    return __create_directory(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool create_directory(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __create_directory(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool create_directory(const path& __p, const path& __attrs) {
-    return __create_directory(__p, __attrs);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool create_directory(const path& __p, const path& __attrs, error_code& __ec) _NOEXCEPT {
-    return __create_directory(__p, __attrs, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void create_directory_symlink(const path& __to, const path& __new) {
-    __create_directory_symlink(__to, __new);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void create_directory_symlink(const path& __to, const path& __new,
-                              error_code& __ec) _NOEXCEPT {
-    __create_directory_symlink(__to, __new, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void create_hard_link(const path& __to, const path& __new) {
-    __create_hard_link(__to, __new);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void create_hard_link(const path& __to, const path& __new, error_code& __ec) _NOEXCEPT {
-    __create_hard_link(__to, __new, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void create_symlink(const path& __to, const path& __new) {
-    __create_symlink(__to, __new);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void create_symlink(const path& __to, const path& __new, error_code& __ec) _NOEXCEPT {
-    return __create_symlink(__to, __new, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool status_known(file_status __s) _NOEXCEPT {
-    return __s.type() != file_type::none;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool exists(file_status __s) _NOEXCEPT {
-    return status_known(__s) && __s.type() != file_type::not_found;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool exists(const path& __p) {
-    return exists(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool exists(const path& __p, error_code& __ec) _NOEXCEPT {
-    auto __s = __status(__p, &__ec);
-    if (status_known(__s)) __ec.clear();
-    return exists(__s);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool equivalent(const path& __p1, const path& __p2) {
-    return __equivalent(__p1, __p2);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool equivalent(const path& __p1, const path& __p2, error_code& __ec) _NOEXCEPT {
-    return __equivalent(__p1, __p2, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-uintmax_t file_size(const path& __p) {
-    return __file_size(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-uintmax_t file_size(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __file_size(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-uintmax_t hard_link_count(const path& __p) {
-    return __hard_link_count(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-uintmax_t hard_link_count(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __hard_link_count(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_block_file(file_status __s) _NOEXCEPT {
-    return __s.type() == file_type::block;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_block_file(const path& __p) {
-    return is_block_file(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_block_file(const path& __p, error_code& __ec) _NOEXCEPT {
-    return is_block_file(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_character_file(file_status __s) _NOEXCEPT {
-    return __s.type() == file_type::character;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_character_file(const path& __p) {
-    return is_character_file(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_character_file(const path& __p, error_code& __ec) _NOEXCEPT {
-    return is_character_file(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_directory(file_status __s) _NOEXCEPT {
-    return __s.type() == file_type::directory;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_directory(const path& __p) {
-    return is_directory(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_directory(const path& __p, error_code& __ec) _NOEXCEPT {
-    return is_directory(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_empty(const path& __p) {
-    return __fs_is_empty(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_empty(const path& __p, error_code& __ec) {
-    return __fs_is_empty(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_fifo(file_status __s) _NOEXCEPT {
-    return __s.type() == file_type::fifo;
-}
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_fifo(const path& __p) {
-    return is_fifo(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_fifo(const path& __p, error_code& __ec) _NOEXCEPT {
-    return is_fifo(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_regular_file(file_status __s) _NOEXCEPT {
-    return __s.type() == file_type::regular;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_regular_file(const path& __p) {
-    return is_regular_file(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_regular_file(const path& __p, error_code& __ec) _NOEXCEPT {
-    return is_regular_file(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_socket(file_status __s) _NOEXCEPT {
-    return __s.type() == file_type::socket;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_socket(const path& __p) {
-    return is_socket(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_socket(const path& __p, error_code& __ec) _NOEXCEPT {
-    return is_socket(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_symlink(file_status __s) _NOEXCEPT {
-    return __s.type() == file_type::symlink;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_symlink(const path& __p) {
-    return is_symlink(__symlink_status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_symlink(const path& __p, error_code& __ec) _NOEXCEPT {
-    return is_symlink(__symlink_status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_other(file_status __s) _NOEXCEPT {
-    return exists(__s)
-        && !is_regular_file(__s) && !is_directory(__s) && !is_symlink(__s);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_other(const path& __p) {
-    return is_other(__status(__p));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool is_other(const path& __p, error_code& __ec) _NOEXCEPT {
-    return is_other(__status(__p, &__ec));
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-file_time_type last_write_time(const path& __p) {
-    return __last_write_time(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-file_time_type last_write_time(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __last_write_time(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void last_write_time(const path& __p, file_time_type __t) {
-    __last_write_time(__p, __t);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void last_write_time(const path& __p, file_time_type __t, error_code& __ec) _NOEXCEPT {
-    __last_write_time(__p, __t, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void permissions(const path& __p, perms __prms) {
-    __permissions(__p, __prms);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void permissions(const path& __p, perms __prms, error_code& __ec)  {
-    __permissions(__p, __prms, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-path read_symlink(const path& __p) {
-    return __read_symlink(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-path read_symlink(const path& __p, error_code& __ec) {
-    return __read_symlink(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool remove(const path& __p) {
-    return __remove(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool remove(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __remove(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-uintmax_t remove_all(const path& __p) {
-    return __remove_all(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-uintmax_t remove_all(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __remove_all(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void rename(const path& __from, const path& __to) {
-    return __rename(__from, __to);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void rename(const path& __from, const path& __to, error_code& __ec) _NOEXCEPT {
-    return __rename(__from, __to, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void resize_file(const path& __p, uintmax_t __ns) {
-    return __resize_file(__p, __ns);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-void resize_file(const path& __p, uintmax_t __ns, error_code& __ec) _NOEXCEPT {
-    return __resize_file(__p, __ns, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-space_info space(const path& __p) {
-    return __space(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-space_info space(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __space(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-file_status status(const path& __p) {
-    return __status(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-file_status status(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __status(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-file_status symlink_status(const path& __p) {
-    return __symlink_status(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-file_status symlink_status(const path& __p, error_code& __ec) _NOEXCEPT {
-    return __symlink_status(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-path system_complete(const path& __p) {
-    return __system_complete(__p);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-path system_complete(const path& __p, error_code& __ec) {
-    return __system_complete(__p, &__ec);
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-path temp_directory_path() {
-    return __temp_directory_path();
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-path temp_directory_path(error_code& __ec) {
-    return __temp_directory_path(&__ec);
-}
-
-
-class directory_entry
-{
-    typedef _VSTD_FS::path _Path;
-
-public:
-    // constructors and destructors
-    directory_entry() _NOEXCEPT = default;
-    directory_entry(directory_entry const&) = default;
-    directory_entry(directory_entry&&) _NOEXCEPT = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit directory_entry(_Path const& __p) : __p_(__p) {}
-
-    ~directory_entry() {}
-
-    directory_entry& operator=(directory_entry const&) = default;
-    directory_entry& operator=(directory_entry&&) _NOEXCEPT = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void assign(_Path const& __p) {
-        __p_ = __p;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void replace_filename(_Path const& __p) {
-        __p_ = __p_.parent_path() / __p;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    _Path const& path() const _NOEXCEPT {
-        return __p_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    operator const _Path&() const _NOEXCEPT {
-        return __p_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    file_status status() const {
-        return _VSTD_FS::status(__p_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    file_status status(error_code& __ec) const _NOEXCEPT {
-        return _VSTD_FS::status(__p_, __ec);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    file_status symlink_status() const {
-        return _VSTD_FS::symlink_status(__p_);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    file_status symlink_status(error_code& __ec) const _NOEXCEPT {
-        return _VSTD_FS::symlink_status(__p_, __ec);
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator< (directory_entry const& __rhs) const _NOEXCEPT {
-        return __p_ < __rhs.__p_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator==(directory_entry const& __rhs) const _NOEXCEPT {
-        return __p_ == __rhs.__p_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator!=(directory_entry const& __rhs) const _NOEXCEPT {
-        return __p_ != __rhs.__p_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator<=(directory_entry const& __rhs) const _NOEXCEPT {
-        return __p_ <= __rhs.__p_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator> (directory_entry const& __rhs) const _NOEXCEPT {
-        return __p_ > __rhs.__p_;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool operator>=(directory_entry const& __rhs) const _NOEXCEPT {
-        return __p_ >= __rhs.__p_;
-    }
-private:
-    _Path __p_;
-};
-
-
-class directory_iterator;
-class recursive_directory_iterator;
-class __dir_stream;
-
-class __dir_element_proxy {
-public:
-
-    inline _LIBCPP_INLINE_VISIBILITY
-    directory_entry operator*() { return _VSTD::move(__elem_); }
-
-private:
-    friend class directory_iterator;
-    friend class recursive_directory_iterator;
-    explicit __dir_element_proxy(directory_entry const& __e) : __elem_(__e) {}
-    __dir_element_proxy(__dir_element_proxy&& __o) : __elem_(_VSTD::move(__o.__elem_)) {}
-    directory_entry __elem_;
-};
-
-class directory_iterator
-{
-public:
-    typedef directory_entry value_type;
-    typedef ptrdiff_t difference_type;
-    typedef value_type const* pointer;
-    typedef value_type const& reference;
-    typedef input_iterator_tag iterator_category;
-
-public:
-    //ctor & dtor
-    directory_iterator() _NOEXCEPT
-    { }
-
-    explicit directory_iterator(const path& __p)
-        : directory_iterator(__p, nullptr)
-    { }
-
-    directory_iterator(const path& __p, directory_options __opts)
-        : directory_iterator(__p, nullptr, __opts)
-    { }
-
-    directory_iterator(const path& __p, error_code& __ec)
-        : directory_iterator(__p, &__ec)
-    { }
-
-    directory_iterator(const path& __p, directory_options __opts,
-                       error_code& __ec)
-        : directory_iterator(__p, &__ec, __opts)
-    { }
-
-    directory_iterator(const directory_iterator&) = default;
-    directory_iterator(directory_iterator&&) = default;
-    directory_iterator& operator=(const directory_iterator&) = default;
-
-    directory_iterator& operator=(directory_iterator&& __o) _NOEXCEPT {
-        // non-default implementation provided to support self-move assign.
-        if (this != &__o) {
-            __imp_ = _VSTD::move(__o.__imp_);
-        }
-        return *this;
-    }
-
-    ~directory_iterator() = default;
-
-    const directory_entry& operator*() const {
-        _LIBCPP_ASSERT(__imp_, "The end iterator cannot be dereferenced");
-        return __dereference();
-    }
-
-    const directory_entry* operator->() const
-    { return &**this; }
-
-    directory_iterator& operator++()
-    { return __increment(); }
-
-    __dir_element_proxy operator++(int) {
-        __dir_element_proxy __p(**this);
-        __increment();
-        return __p;
-    }
-
-    directory_iterator& increment(error_code& __ec)
-    { return __increment(&__ec); }
-
-private:
-    inline _LIBCPP_INLINE_VISIBILITY
-    friend bool operator==(const directory_iterator& __lhs,
-                           const directory_iterator& __rhs) _NOEXCEPT;
-
-    // construct the dir_stream
-    _LIBCPP_FUNC_VIS
-    directory_iterator(const path&, error_code *,
-                       directory_options = directory_options::none);
-
-    _LIBCPP_FUNC_VIS
-    directory_iterator& __increment(error_code * __ec = nullptr);
-
-    _LIBCPP_FUNC_VIS
-    const directory_entry& __dereference() const;
-
-private:
-    shared_ptr<__dir_stream> __imp_;
-};
-
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(const directory_iterator& __lhs,
-                const directory_iterator& __rhs) _NOEXCEPT {
-    return __lhs.__imp_ == __rhs.__imp_;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator!=(const directory_iterator& __lhs,
-                const directory_iterator& __rhs) _NOEXCEPT {
-    return !(__lhs == __rhs);
-}
-
-// enable directory_iterator range-based for statements
-inline _LIBCPP_INLINE_VISIBILITY
-directory_iterator begin(directory_iterator __iter) _NOEXCEPT {
-    return __iter;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-directory_iterator end(const directory_iterator&) _NOEXCEPT {
-    return directory_iterator();
-}
-
-class recursive_directory_iterator {
-public:
-    using value_type = directory_entry;
-    using difference_type = std::ptrdiff_t;
-    using pointer = directory_entry const *;
-    using reference = directory_entry const &;
-    using iterator_category = std::input_iterator_tag;
-
-public:
-    // constructors and destructor
-    _LIBCPP_INLINE_VISIBILITY
-    recursive_directory_iterator()  _NOEXCEPT
-        : __rec_(false)
-    {}
-
-    _LIBCPP_INLINE_VISIBILITY
-    explicit recursive_directory_iterator(const path& __p,
-                directory_options __xoptions = directory_options::none)
-        : recursive_directory_iterator(__p, __xoptions,  nullptr)
-    { }
-
-    _LIBCPP_INLINE_VISIBILITY
-    recursive_directory_iterator(const path& __p,
-        directory_options __xoptions, error_code& __ec)
-        : recursive_directory_iterator(__p, __xoptions, &__ec)
-    { }
-
-    _LIBCPP_INLINE_VISIBILITY
-    recursive_directory_iterator(const path& __p, error_code& __ec)
-        : recursive_directory_iterator(__p, directory_options::none,  &__ec)
-    { }
-
-    recursive_directory_iterator(const recursive_directory_iterator&) = default;
-    recursive_directory_iterator(recursive_directory_iterator&&) = default;
-
-    recursive_directory_iterator &
-    operator=(const recursive_directory_iterator&) = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    recursive_directory_iterator &
-    operator=(recursive_directory_iterator&& __o) noexcept {
-        // non-default implementation provided to support self-move assign.
-        if (this != &__o) {
-            __imp_ = _VSTD::move(__o.__imp_);
-            __rec_ = __o.__rec_;
-        }
-        return *this;
-    }
-
-    ~recursive_directory_iterator() = default;
-
-    _LIBCPP_INLINE_VISIBILITY
-    const directory_entry& operator*() const
-    { return __dereference(); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    const directory_entry* operator->() const
-    { return &__dereference(); }
-
-    recursive_directory_iterator& operator++()
-    { return __increment(); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    __dir_element_proxy operator++(int) {
-        __dir_element_proxy __p(**this);
-        __increment();
-        return __p;
-    }
-
-    _LIBCPP_INLINE_VISIBILITY
-    recursive_directory_iterator& increment(error_code& __ec)
-    { return __increment(&__ec); }
-
-    _LIBCPP_FUNC_VIS directory_options options() const;
-    _LIBCPP_FUNC_VIS int  depth() const;
-
-    _LIBCPP_INLINE_VISIBILITY
-    void pop() { __pop(); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void pop(error_code& __ec)
-    { __pop(&__ec); }
-
-    _LIBCPP_INLINE_VISIBILITY
-    bool recursion_pending() const
-    { return __rec_; }
-
-    _LIBCPP_INLINE_VISIBILITY
-    void disable_recursion_pending()
-    { __rec_ = false; }
-
-private:
-    recursive_directory_iterator(const path& __p, directory_options __opt,
-                                 error_code *__ec);
-
-    _LIBCPP_FUNC_VIS
-    const directory_entry& __dereference() const;
-
-    _LIBCPP_FUNC_VIS
-    bool __try_recursion(error_code* __ec);
-
-    _LIBCPP_FUNC_VIS
-    void __advance(error_code* __ec=nullptr);
-
-    _LIBCPP_FUNC_VIS
-    recursive_directory_iterator& __increment(error_code *__ec=nullptr);
-
-    _LIBCPP_FUNC_VIS
-    void __pop(error_code* __ec=nullptr);
-
-    inline _LIBCPP_INLINE_VISIBILITY
-    friend bool operator==(const recursive_directory_iterator&,
-                           const recursive_directory_iterator&) _NOEXCEPT;
-
-    struct __shared_imp;
-    shared_ptr<__shared_imp> __imp_;
-    bool __rec_;
-};                                     // class recursive_directory_iterator
-
-
-inline _LIBCPP_INLINE_VISIBILITY
-bool operator==(const recursive_directory_iterator& __lhs,
-                const recursive_directory_iterator& __rhs) _NOEXCEPT
-{
-    return __lhs.__imp_ == __rhs.__imp_;
-}
-
-_LIBCPP_INLINE_VISIBILITY
-inline bool operator!=(const recursive_directory_iterator& __lhs,
-                        const recursive_directory_iterator& __rhs) _NOEXCEPT
-{
-    return !(__lhs == __rhs);
-}
-// enable recursive_directory_iterator range-based for statements
-inline _LIBCPP_INLINE_VISIBILITY
-recursive_directory_iterator begin(recursive_directory_iterator __iter) _NOEXCEPT {
-    return __iter;
-}
-
-inline _LIBCPP_INLINE_VISIBILITY
-recursive_directory_iterator end(const recursive_directory_iterator&) _NOEXCEPT {
-    return recursive_directory_iterator();
-}
+#endif // !_LIBCPP_CXX03_LANG
 
-_LIBCPP_END_NAMESPACE_EXPERIMENTAL_FILESYSTEM
+_LIBCPP_POP_MACROS
 
 #endif // _LIBCPP_EXPERIMENTAL_FILESYSTEM