lib: establish Zircon libc++ and KTL foundation

1 files changed, 1501 insertions, 0 deletions

diff --git a/third_party/libcxx/include/c++/v1/__locale b/third_party/libcxx/include/c++/v1/__locale
new file mode 100644
index 0000000..5b17874
--- /dev/null
+++ b/third_party/libcxx/include/c++/v1/__locale
@@ -0,0 +1,1501 @@
+// -*- C++ -*-
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___LOCALE
+#define _LIBCPP___LOCALE
+
+#include <__config>
+
+#if _LIBCPP_HAS_LOCALIZATION
+
+#  include <__locale_dir/locale_base_api.h>
+#  include <__memory/addressof.h>
+#  include <__memory/shared_count.h>
+#  include <__mutex/once_flag.h>
+#  include <__type_traits/make_unsigned.h>
+#  include <__utility/no_destroy.h>
+#  include <__utility/private_constructor_tag.h>
+#  include <cctype>
+#  include <clocale>
+#  include <cstdint>
+#  include <cstdlib>
+#  include <string>
+
+// Some platforms require more includes than others. Keep the includes on all plaforms for now.
+#  include <cstddef>
+#  include <cstring>
+
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+#    include <cwchar>
+#  else
+#    include <__std_mbstate_t.h>
+#  endif
+
+#  if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#    pragma GCC system_header
+#  endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+class _LIBCPP_EXPORTED_FROM_ABI locale;
+
+template <class _CharT>
+class collate;
+
+template <class _Facet>
+_LIBCPP_HIDE_FROM_ABI bool has_facet(const locale&) _NOEXCEPT;
+
+template <class _Facet>
+_LIBCPP_HIDE_FROM_ABI const _Facet& use_facet(const locale&);
+
+class _LIBCPP_EXPORTED_FROM_ABI locale {
+public:
+  // locale is essentially a shared_ptr that doesn't support weak_ptrs and never got a move constructor,
+  // so it is trivially relocatable.
+  using __trivially_relocatable _LIBCPP_NODEBUG = locale;
+
+  // types:
+  class _LIBCPP_EXPORTED_FROM_ABI facet;
+  class _LIBCPP_EXPORTED_FROM_ABI id;
+
+  typedef int category;
+
+  static const category // values assigned here are for exposition only
+      none    = 0,
+      collate = _LIBCPP_COLLATE_MASK, ctype = _LIBCPP_CTYPE_MASK, monetary = _LIBCPP_MONETARY_MASK,
+      numeric = _LIBCPP_NUMERIC_MASK, time = _LIBCPP_TIME_MASK, messages = _LIBCPP_MESSAGES_MASK,
+      all = collate | ctype | monetary | numeric | time | messages;
+
+  // construct/copy/destroy:
+  locale() _NOEXCEPT;
+  locale(const locale&) _NOEXCEPT;
+  explicit locale(const char*);
+  explicit locale(const string&);
+  locale(const locale&, const char*, category);
+  locale(const locale&, const string&, category);
+  template <class _Facet>
+  _LIBCPP_HIDE_FROM_ABI locale(const locale&, _Facet*);
+  locale(const locale&, const locale&, category);
+
+  ~locale();
+
+  const locale& operator=(const locale&) _NOEXCEPT;
+
+  template <class _Facet>
+  _LIBCPP_HIDE_FROM_ABI locale combine(const locale& __other) const {
+    if (!std::has_facet<_Facet>(__other))
+      __throw_runtime_error("locale::combine: locale missing facet");
+
+    return locale(*this, std::addressof(const_cast<_Facet&>(std::use_facet<_Facet>(__other))));
+  }
+
+  // locale operations:
+  string name() const;
+  bool operator==(const locale&) const;
+#  if _LIBCPP_STD_VER <= 17
+  _LIBCPP_HIDE_FROM_ABI bool operator!=(const locale& __y) const { return !(*this == __y); }
+#  endif
+  template <class _CharT, class _Traits, class _Allocator>
+  _LIBCPP_HIDE_FROM_ABI bool operator()(const basic_string<_CharT, _Traits, _Allocator>& __x,
+                                        const basic_string<_CharT, _Traits, _Allocator>& __y) const {
+    return std::use_facet<std::collate<_CharT> >(*this).compare(
+               __x.data(), __x.data() + __x.size(), __y.data(), __y.data() + __y.size()) < 0;
+  }
+
+  // global locale objects:
+  static locale global(const locale&);
+  static const locale& classic();
+
+private:
+  class __imp;
+  __imp* __locale_;
+
+  template <class>
+  friend struct __no_destroy;
+  _LIBCPP_HIDE_FROM_ABI explicit locale(__private_constructor_tag, __imp* __loc) : __locale_(__loc) {}
+
+  void __install_ctor(const locale&, facet*, long);
+  static locale& __global();
+  bool has_facet(id&) const;
+  const facet* use_facet(id&) const;
+
+  template <class _Facet>
+  friend bool has_facet(const locale&) _NOEXCEPT;
+  template <class _Facet>
+  friend const _Facet& use_facet(const locale&);
+};
+
+class _LIBCPP_EXPORTED_FROM_ABI locale::facet : public __shared_count {
+protected:
+  _LIBCPP_HIDE_FROM_ABI explicit facet(size_t __refs = 0) : __shared_count(static_cast<long>(__refs) - 1) {}
+
+  ~facet() override;
+
+  //    facet(const facet&) = delete;     // effectively done in __shared_count
+  //    void operator=(const facet&) = delete;
+
+private:
+  void __on_zero_shared() _NOEXCEPT override;
+};
+
+class _LIBCPP_EXPORTED_FROM_ABI locale::id {
+  once_flag __flag_;
+  int32_t __id_;
+
+  static int32_t __next_id;
+
+public:
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR id() : __id_(0) {}
+  void operator=(const id&) = delete;
+  id(const id&)             = delete;
+
+public: // only needed for tests
+  long __get();
+
+  friend class locale;
+  friend class locale::__imp;
+};
+
+template <class _Facet>
+inline _LIBCPP_HIDE_FROM_ABI locale::locale(const locale& __other, _Facet* __f) {
+  __install_ctor(__other, __f, __f ? __f->id.__get() : 0);
+}
+
+template <class _Facet>
+inline _LIBCPP_HIDE_FROM_ABI bool has_facet(const locale& __l) _NOEXCEPT {
+  return __l.has_facet(_Facet::id);
+}
+
+template <class _Facet>
+inline _LIBCPP_HIDE_FROM_ABI const _Facet& use_facet(const locale& __l) {
+  return static_cast<const _Facet&>(*__l.use_facet(_Facet::id));
+}
+
+// template <class _CharT> class collate;
+
+template <class _CharT>
+class collate : public locale::facet {
+public:
+  typedef _CharT char_type;
+  typedef basic_string<char_type> string_type;
+
+  _LIBCPP_HIDE_FROM_ABI explicit collate(size_t __refs = 0) : locale::facet(__refs) {}
+
+  _LIBCPP_HIDE_FROM_ABI int
+  compare(const char_type* __lo1, const char_type* __hi1, const char_type* __lo2, const char_type* __hi2) const {
+    return do_compare(__lo1, __hi1, __lo2, __hi2);
+  }
+
+  // FIXME(EricWF): The _LIBCPP_ALWAYS_INLINE is needed on Windows to work
+  // around a dllimport bug that expects an external instantiation.
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_ALWAYS_INLINE string_type
+  transform(const char_type* __lo, const char_type* __hi) const {
+    return do_transform(__lo, __hi);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI long hash(const char_type* __lo, const char_type* __hi) const { return do_hash(__lo, __hi); }
+
+  static locale::id id;
+
+protected:
+  ~collate() override;
+  virtual int
+  do_compare(const char_type* __lo1, const char_type* __hi1, const char_type* __lo2, const char_type* __hi2) const;
+  virtual string_type do_transform(const char_type* __lo, const char_type* __hi) const {
+    return string_type(__lo, __hi);
+  }
+  virtual long do_hash(const char_type* __lo, const char_type* __hi) const;
+};
+
+template <class _CharT>
+locale::id collate<_CharT>::id;
+
+template <class _CharT>
+collate<_CharT>::~collate() {}
+
+template <class _CharT>
+int collate<_CharT>::do_compare(
+    const char_type* __lo1, const char_type* __hi1, const char_type* __lo2, const char_type* __hi2) const {
+  for (; __lo2 != __hi2; ++__lo1, ++__lo2) {
+    if (__lo1 == __hi1 || *__lo1 < *__lo2)
+      return -1;
+    if (*__lo2 < *__lo1)
+      return 1;
+  }
+  return __lo1 != __hi1;
+}
+
+template <class _CharT>
+long collate<_CharT>::do_hash(const char_type* __lo, const char_type* __hi) const {
+  size_t __h          = 0;
+  const size_t __sr   = __CHAR_BIT__ * sizeof(size_t) - 8;
+  const size_t __mask = size_t(0xF) << (__sr + 4);
+  for (const char_type* __p = __lo; __p != __hi; ++__p) {
+    __h        = (__h << 4) + static_cast<size_t>(*__p);
+    size_t __g = __h & __mask;
+    __h ^= __g | (__g >> __sr);
+  }
+  return static_cast<long>(__h);
+}
+
+extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS collate<char>;
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS collate<wchar_t>;
+#  endif
+
+// template <class CharT> class collate_byname;
+
+template <class _CharT>
+class collate_byname;
+
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI collate_byname<char> : public collate<char> {
+  __locale::__locale_t __l_;
+
+public:
+  typedef char char_type;
+  typedef basic_string<char_type> string_type;
+
+  explicit collate_byname(const char* __n, size_t __refs = 0);
+  explicit collate_byname(const string& __n, size_t __refs = 0);
+
+protected:
+  ~collate_byname() override;
+  int do_compare(
+      const char_type* __lo1, const char_type* __hi1, const char_type* __lo2, const char_type* __hi2) const override;
+  string_type do_transform(const char_type* __lo, const char_type* __hi) const override;
+};
+
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI collate_byname<wchar_t> : public collate<wchar_t> {
+  __locale::__locale_t __l_;
+
+public:
+  typedef wchar_t char_type;
+  typedef basic_string<char_type> string_type;
+
+  explicit collate_byname(const char* __n, size_t __refs = 0);
+  explicit collate_byname(const string& __n, size_t __refs = 0);
+
+protected:
+  ~collate_byname() override;
+
+  int do_compare(
+      const char_type* __lo1, const char_type* __hi1, const char_type* __lo2, const char_type* __hi2) const override;
+  string_type do_transform(const char_type* __lo, const char_type* __hi) const override;
+};
+#  endif
+
+// template <class charT> class ctype
+
+class _LIBCPP_EXPORTED_FROM_ABI ctype_base {
+public:
+#  if defined(_LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE)
+  typedef unsigned long mask;
+  static const mask space  = 1 << 0;
+  static const mask print  = 1 << 1;
+  static const mask cntrl  = 1 << 2;
+  static const mask upper  = 1 << 3;
+  static const mask lower  = 1 << 4;
+  static const mask alpha  = 1 << 5;
+  static const mask digit  = 1 << 6;
+  static const mask punct  = 1 << 7;
+  static const mask xdigit = 1 << 8;
+  static const mask blank  = 1 << 9;
+#    if defined(__BIONIC__)
+  // Historically this was a part of regex_traits rather than ctype_base. The
+  // historical value of the constant is preserved for ABI compatibility.
+  static const mask __regex_word = 0x8000;
+#    else
+  static const mask __regex_word = 1 << 10;
+#    endif // defined(__BIONIC__)
+#  elif defined(__GLIBC__)
+  typedef unsigned short mask;
+  static const mask space  = _ISspace;
+  static const mask print  = _ISprint;
+  static const mask cntrl  = _IScntrl;
+  static const mask upper  = _ISupper;
+  static const mask lower  = _ISlower;
+  static const mask alpha  = _ISalpha;
+  static const mask digit  = _ISdigit;
+  static const mask punct  = _ISpunct;
+  static const mask xdigit = _ISxdigit;
+  static const mask blank  = _ISblank;
+#    if defined(__mips__) || (BYTE_ORDER == BIG_ENDIAN)
+  static const mask __regex_word = static_cast<mask>(_ISbit(15));
+#    else
+  static const mask __regex_word = 0x80;
+#    endif
+#  elif defined(_LIBCPP_MSVCRT_LIKE)
+  typedef unsigned short mask;
+  static const mask space        = _SPACE;
+  static const mask print        = _BLANK | _PUNCT | _ALPHA | _DIGIT;
+  static const mask cntrl        = _CONTROL;
+  static const mask upper        = _UPPER;
+  static const mask lower        = _LOWER;
+  static const mask alpha        = _ALPHA;
+  static const mask digit        = _DIGIT;
+  static const mask punct        = _PUNCT;
+  static const mask xdigit       = _HEX;
+  static const mask blank        = _BLANK;
+  static const mask __regex_word = 0x4000; // 0x8000 and 0x0100 and 0x00ff are used
+#    define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
+#    define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_ALPHA
+#  elif defined(__APPLE__) || defined(__FreeBSD__) || defined(__NetBSD__)
+#    ifdef __APPLE__
+  typedef uint32_t mask;
+#    elif defined(__FreeBSD__)
+  typedef unsigned long mask;
+#    elif defined(__NetBSD__)
+  typedef unsigned short mask;
+#    endif
+  static const mask space  = _CTYPE_S;
+  static const mask print  = _CTYPE_R;
+  static const mask cntrl  = _CTYPE_C;
+  static const mask upper  = _CTYPE_U;
+  static const mask lower  = _CTYPE_L;
+  static const mask alpha  = _CTYPE_A;
+  static const mask digit  = _CTYPE_D;
+  static const mask punct  = _CTYPE_P;
+  static const mask xdigit = _CTYPE_X;
+
+#    if defined(__NetBSD__)
+  static const mask blank = _CTYPE_BL;
+  // NetBSD defines classes up to 0x2000
+  // see sys/ctype_bits.h, _CTYPE_Q
+  static const mask __regex_word = 0x8000;
+#    else
+  static const mask blank        = _CTYPE_B;
+  static const mask __regex_word = 0x80;
+#    endif
+#  elif defined(_AIX)
+  typedef unsigned int mask;
+  static const mask space        = _ISSPACE;
+  static const mask print        = _ISPRINT;
+  static const mask cntrl        = _ISCNTRL;
+  static const mask upper        = _ISUPPER;
+  static const mask lower        = _ISLOWER;
+  static const mask alpha        = _ISALPHA;
+  static const mask digit        = _ISDIGIT;
+  static const mask punct        = _ISPUNCT;
+  static const mask xdigit       = _ISXDIGIT;
+  static const mask blank        = _ISBLANK;
+  static const mask __regex_word = 0x8000;
+#  elif _LIBCPP_LIBC_NEWLIB
+  // Same type as Newlib's _ctype_ array in newlib/libc/include/ctype.h.
+  typedef char mask;
+  // In case char is signed, static_cast is needed to avoid warning on
+  // positive value becomming negative.
+  static const mask space  = static_cast<mask>(_S);
+  static const mask print  = static_cast<mask>(_P | _U | _L | _N | _B);
+  static const mask cntrl  = static_cast<mask>(_C);
+  static const mask upper  = static_cast<mask>(_U);
+  static const mask lower  = static_cast<mask>(_L);
+  static const mask alpha  = static_cast<mask>(_U | _L);
+  static const mask digit  = static_cast<mask>(_N);
+  static const mask punct  = static_cast<mask>(_P);
+  static const mask xdigit = static_cast<mask>(_X | _N);
+  static const mask blank  = static_cast<mask>(_B);
+  // mask is already fully saturated, use a different type in regex_type_traits.
+  static const unsigned short __regex_word = 0x100;
+#    define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_PRINT
+#    define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_ALPHA
+#    define _LIBCPP_CTYPE_MASK_IS_COMPOSITE_XDIGIT
+#  elif defined(__MVS__)
+#    if defined(__NATIVE_ASCII_F)
+  typedef unsigned int mask;
+  static const mask space  = _ISSPACE_A;
+  static const mask print  = _ISPRINT_A;
+  static const mask cntrl  = _ISCNTRL_A;
+  static const mask upper  = _ISUPPER_A;
+  static const mask lower  = _ISLOWER_A;
+  static const mask alpha  = _ISALPHA_A;
+  static const mask digit  = _ISDIGIT_A;
+  static const mask punct  = _ISPUNCT_A;
+  static const mask xdigit = _ISXDIGIT_A;
+  static const mask blank  = _ISBLANK_A;
+#    else
+  typedef unsigned short mask;
+  static const mask space  = __ISSPACE;
+  static const mask print  = __ISPRINT;
+  static const mask cntrl  = __ISCNTRL;
+  static const mask upper  = __ISUPPER;
+  static const mask lower  = __ISLOWER;
+  static const mask alpha  = __ISALPHA;
+  static const mask digit  = __ISDIGIT;
+  static const mask punct  = __ISPUNCT;
+  static const mask xdigit = __ISXDIGIT;
+  static const mask blank  = __ISBLANK;
+#    endif
+  static const mask __regex_word = 0x8000;
+#  else
+#    error unknown rune table for this platform -- do you mean to define _LIBCPP_PROVIDES_DEFAULT_RUNE_TABLE?
+#  endif
+  static const mask alnum = alpha | digit;
+  static const mask graph = alnum | punct;
+
+  _LIBCPP_HIDE_FROM_ABI ctype_base() {}
+
+  static_assert((__regex_word & ~(std::make_unsigned<mask>::type)(space | print | cntrl | upper | lower | alpha |
+                                                                  digit | punct | xdigit | blank)) == __regex_word,
+                "__regex_word can't overlap other bits");
+};
+
+template <class _CharT>
+class ctype;
+
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI ctype<wchar_t> : public locale::facet, public ctype_base {
+public:
+  typedef wchar_t char_type;
+
+  _LIBCPP_HIDE_FROM_ABI explicit ctype(size_t __refs = 0) : locale::facet(__refs) {}
+
+  _LIBCPP_HIDE_FROM_ABI bool is(mask __m, char_type __c) const { return do_is(__m, __c); }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* is(const char_type* __low, const char_type* __high, mask* __vec) const {
+    return do_is(__low, __high, __vec);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* scan_is(mask __m, const char_type* __low, const char_type* __high) const {
+    return do_scan_is(__m, __low, __high);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* scan_not(mask __m, const char_type* __low, const char_type* __high) const {
+    return do_scan_not(__m, __low, __high);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI char_type toupper(char_type __c) const { return do_toupper(__c); }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* toupper(char_type* __low, const char_type* __high) const {
+    return do_toupper(__low, __high);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI char_type tolower(char_type __c) const { return do_tolower(__c); }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* tolower(char_type* __low, const char_type* __high) const {
+    return do_tolower(__low, __high);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI char_type widen(char __c) const { return do_widen(__c); }
+
+  _LIBCPP_HIDE_FROM_ABI const char* widen(const char* __low, const char* __high, char_type* __to) const {
+    return do_widen(__low, __high, __to);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI char narrow(char_type __c, char __dfault) const { return do_narrow(__c, __dfault); }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type*
+  narrow(const char_type* __low, const char_type* __high, char __dfault, char* __to) const {
+    return do_narrow(__low, __high, __dfault, __to);
+  }
+
+  static locale::id id;
+
+protected:
+  ~ctype() override;
+  virtual bool do_is(mask __m, char_type __c) const;
+  virtual const char_type* do_is(const char_type* __low, const char_type* __high, mask* __vec) const;
+  virtual const char_type* do_scan_is(mask __m, const char_type* __low, const char_type* __high) const;
+  virtual const char_type* do_scan_not(mask __m, const char_type* __low, const char_type* __high) const;
+  virtual char_type do_toupper(char_type) const;
+  virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
+  virtual char_type do_tolower(char_type) const;
+  virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
+  virtual char_type do_widen(char) const;
+  virtual const char* do_widen(const char* __low, const char* __high, char_type* __dest) const;
+  virtual char do_narrow(char_type, char __dfault) const;
+  virtual const char_type*
+  do_narrow(const char_type* __low, const char_type* __high, char __dfault, char* __dest) const;
+};
+#  endif // _LIBCPP_HAS_WIDE_CHARACTERS
+
+inline _LIBCPP_HIDE_FROM_ABI bool __libcpp_isascii(int __c) { return (__c & ~0x7F) == 0; }
+
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI ctype<char> : public locale::facet, public ctype_base {
+  const mask* __tab_;
+  bool __del_;
+
+public:
+  typedef char char_type;
+
+  explicit ctype(const mask* __tab = nullptr, bool __del = false, size_t __refs = 0);
+
+  _LIBCPP_HIDE_FROM_ABI bool is(mask __m, char_type __c) const {
+    return std::__libcpp_isascii(__c) ? (__tab_[static_cast<int>(__c)] & __m) != 0 : false;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* is(const char_type* __low, const char_type* __high, mask* __vec) const {
+    for (; __low != __high; ++__low, ++__vec)
+      *__vec = std::__libcpp_isascii(*__low) ? __tab_[static_cast<int>(*__low)] : 0;
+    return __low;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* scan_is(mask __m, const char_type* __low, const char_type* __high) const {
+    for (; __low != __high; ++__low)
+      if (std::__libcpp_isascii(*__low) && (__tab_[static_cast<int>(*__low)] & __m))
+        break;
+    return __low;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* scan_not(mask __m, const char_type* __low, const char_type* __high) const {
+    for (; __low != __high; ++__low)
+      if (!std::__libcpp_isascii(*__low) || !(__tab_[static_cast<int>(*__low)] & __m))
+        break;
+    return __low;
+  }
+
+  _LIBCPP_HIDE_FROM_ABI char_type toupper(char_type __c) const { return do_toupper(__c); }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* toupper(char_type* __low, const char_type* __high) const {
+    return do_toupper(__low, __high);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI char_type tolower(char_type __c) const { return do_tolower(__c); }
+
+  _LIBCPP_HIDE_FROM_ABI const char_type* tolower(char_type* __low, const char_type* __high) const {
+    return do_tolower(__low, __high);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI char_type widen(char __c) const { return do_widen(__c); }
+
+  _LIBCPP_HIDE_FROM_ABI const char* widen(const char* __low, const char* __high, char_type* __to) const {
+    return do_widen(__low, __high, __to);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI char narrow(char_type __c, char __dfault) const { return do_narrow(__c, __dfault); }
+
+  _LIBCPP_HIDE_FROM_ABI const char*
+  narrow(const char_type* __low, const char_type* __high, char __dfault, char* __to) const {
+    return do_narrow(__low, __high, __dfault, __to);
+  }
+
+  static locale::id id;
+
+#  ifdef _CACHED_RUNES
+  static const size_t table_size = _CACHED_RUNES;
+#  else
+  static const size_t table_size = 256;
+#  endif
+  _LIBCPP_HIDE_FROM_ABI const mask* table() const _NOEXCEPT { return __tab_; }
+  static const mask* classic_table() _NOEXCEPT;
+
+protected:
+  ~ctype() override;
+  virtual char_type do_toupper(char_type __c) const;
+  virtual const char_type* do_toupper(char_type* __low, const char_type* __high) const;
+  virtual char_type do_tolower(char_type __c) const;
+  virtual const char_type* do_tolower(char_type* __low, const char_type* __high) const;
+  virtual char_type do_widen(char __c) const;
+  virtual const char* do_widen(const char* __low, const char* __high, char_type* __to) const;
+  virtual char do_narrow(char_type __c, char __dfault) const;
+  virtual const char* do_narrow(const char_type* __low, const char_type* __high, char __dfault, char* __to) const;
+};
+
+// template <class CharT> class ctype_byname;
+
+template <class _CharT>
+class ctype_byname;
+
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI ctype_byname<char> : public ctype<char> {
+  __locale::__locale_t __l_;
+
+public:
+  explicit ctype_byname(const char*, size_t = 0);
+  explicit ctype_byname(const string&, size_t = 0);
+
+protected:
+  ~ctype_byname() override;
+  char_type do_toupper(char_type) const override;
+  const char_type* do_toupper(char_type* __low, const char_type* __high) const override;
+  char_type do_tolower(char_type) const override;
+  const char_type* do_tolower(char_type* __low, const char_type* __high) const override;
+};
+
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI ctype_byname<wchar_t> : public ctype<wchar_t> {
+  __locale::__locale_t __l_;
+
+public:
+  explicit ctype_byname(const char*, size_t = 0);
+  explicit ctype_byname(const string&, size_t = 0);
+
+protected:
+  ~ctype_byname() override;
+  bool do_is(mask __m, char_type __c) const override;
+  const char_type* do_is(const char_type* __low, const char_type* __high, mask* __vec) const override;
+  const char_type* do_scan_is(mask __m, const char_type* __low, const char_type* __high) const override;
+  const char_type* do_scan_not(mask __m, const char_type* __low, const char_type* __high) const override;
+  char_type do_toupper(char_type) const override;
+  const char_type* do_toupper(char_type* __low, const char_type* __high) const override;
+  char_type do_tolower(char_type) const override;
+  const char_type* do_tolower(char_type* __low, const char_type* __high) const override;
+  char_type do_widen(char) const override;
+  const char* do_widen(const char* __low, const char* __high, char_type* __dest) const override;
+  char do_narrow(char_type, char __dfault) const override;
+  const char_type*
+  do_narrow(const char_type* __low, const char_type* __high, char __dfault, char* __dest) const override;
+};
+#  endif // _LIBCPP_HAS_WIDE_CHARACTERS
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool isspace(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::space, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool isprint(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::print, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool iscntrl(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::cntrl, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool isupper(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::upper, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool islower(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::lower, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool isalpha(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::alpha, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool isdigit(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::digit, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool ispunct(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::punct, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool isxdigit(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::xdigit, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool isalnum(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::alnum, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI bool isgraph(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::graph, __c);
+}
+
+template <class _CharT>
+_LIBCPP_HIDE_FROM_ABI bool isblank(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).is(ctype_base::blank, __c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI _CharT toupper(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).toupper(__c);
+}
+
+template <class _CharT>
+inline _LIBCPP_HIDE_FROM_ABI _CharT tolower(_CharT __c, const locale& __loc) {
+  return std::use_facet<ctype<_CharT> >(__loc).tolower(__c);
+}
+
+// codecvt_base
+
+class _LIBCPP_EXPORTED_FROM_ABI codecvt_base {
+public:
+  _LIBCPP_HIDE_FROM_ABI codecvt_base() {}
+  enum result { ok, partial, error, noconv };
+};
+
+// template <class internT, class externT, class stateT> class codecvt;
+
+template <class _InternT, class _ExternT, class _StateT>
+class codecvt;
+
+// template <> class codecvt<char, char, mbstate_t>
+
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI codecvt<char, char, mbstate_t> : public locale::facet, public codecvt_base {
+public:
+  typedef char intern_type;
+  typedef char extern_type;
+  typedef mbstate_t state_type;
+
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(size_t __refs = 0) : locale::facet(__refs) {}
+
+  _LIBCPP_HIDE_FROM_ABI result
+  out(state_type& __st,
+      const intern_type* __frm,
+      const intern_type* __frm_end,
+      const intern_type*& __frm_nxt,
+      extern_type* __to,
+      extern_type* __to_end,
+      extern_type*& __to_nxt) const {
+    return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const {
+    return do_unshift(__st, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  in(state_type& __st,
+     const extern_type* __frm,
+     const extern_type* __frm_end,
+     const extern_type*& __frm_nxt,
+     intern_type* __to,
+     intern_type* __to_end,
+     intern_type*& __to_nxt) const {
+    return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int encoding() const _NOEXCEPT { return do_encoding(); }
+
+  _LIBCPP_HIDE_FROM_ABI bool always_noconv() const _NOEXCEPT { return do_always_noconv(); }
+
+  _LIBCPP_HIDE_FROM_ABI int
+  length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const {
+    return do_length(__st, __frm, __end, __mx);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int max_length() const _NOEXCEPT { return do_max_length(); }
+
+  static locale::id id;
+
+protected:
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(const char*, size_t __refs = 0) : locale::facet(__refs) {}
+
+  ~codecvt() override;
+
+  virtual result
+  do_out(state_type& __st,
+         const intern_type* __frm,
+         const intern_type* __frm_end,
+         const intern_type*& __frm_nxt,
+         extern_type* __to,
+         extern_type* __to_end,
+         extern_type*& __to_nxt) const;
+  virtual result
+  do_in(state_type& __st,
+        const extern_type* __frm,
+        const extern_type* __frm_end,
+        const extern_type*& __frm_nxt,
+        intern_type* __to,
+        intern_type* __to_end,
+        intern_type*& __to_nxt) const;
+  virtual result do_unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+  virtual int do_encoding() const _NOEXCEPT;
+  virtual bool do_always_noconv() const _NOEXCEPT;
+  virtual int do_length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+  virtual int do_max_length() const _NOEXCEPT;
+};
+
+// template <> class codecvt<wchar_t, char, mbstate_t>
+
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI codecvt<wchar_t, char, mbstate_t> : public locale::facet, public codecvt_base {
+  __locale::__locale_t __l_;
+
+public:
+  typedef wchar_t intern_type;
+  typedef char extern_type;
+  typedef mbstate_t state_type;
+
+  explicit codecvt(size_t __refs = 0);
+
+  _LIBCPP_HIDE_FROM_ABI result
+  out(state_type& __st,
+      const intern_type* __frm,
+      const intern_type* __frm_end,
+      const intern_type*& __frm_nxt,
+      extern_type* __to,
+      extern_type* __to_end,
+      extern_type*& __to_nxt) const {
+    return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const {
+    return do_unshift(__st, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  in(state_type& __st,
+     const extern_type* __frm,
+     const extern_type* __frm_end,
+     const extern_type*& __frm_nxt,
+     intern_type* __to,
+     intern_type* __to_end,
+     intern_type*& __to_nxt) const {
+    return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int encoding() const _NOEXCEPT { return do_encoding(); }
+
+  _LIBCPP_HIDE_FROM_ABI bool always_noconv() const _NOEXCEPT { return do_always_noconv(); }
+
+  _LIBCPP_HIDE_FROM_ABI int
+  length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const {
+    return do_length(__st, __frm, __end, __mx);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int max_length() const _NOEXCEPT { return do_max_length(); }
+
+  static locale::id id;
+
+protected:
+  explicit codecvt(const char*, size_t __refs = 0);
+
+  ~codecvt() override;
+
+  virtual result
+  do_out(state_type& __st,
+         const intern_type* __frm,
+         const intern_type* __frm_end,
+         const intern_type*& __frm_nxt,
+         extern_type* __to,
+         extern_type* __to_end,
+         extern_type*& __to_nxt) const;
+  virtual result
+  do_in(state_type& __st,
+        const extern_type* __frm,
+        const extern_type* __frm_end,
+        const extern_type*& __frm_nxt,
+        intern_type* __to,
+        intern_type* __to_end,
+        intern_type*& __to_nxt) const;
+  virtual result do_unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+  virtual int do_encoding() const _NOEXCEPT;
+  virtual bool do_always_noconv() const _NOEXCEPT;
+  virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+  virtual int do_max_length() const _NOEXCEPT;
+};
+#  endif // _LIBCPP_HAS_WIDE_CHARACTERS
+
+// template <> class codecvt<char16_t, char, mbstate_t> // deprecated in C++20
+
+template <>
+class _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_EXPORTED_FROM_ABI codecvt<char16_t, char, mbstate_t>
+    : public locale::facet, public codecvt_base {
+public:
+  typedef char16_t intern_type;
+  typedef char extern_type;
+  typedef mbstate_t state_type;
+
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(size_t __refs = 0) : locale::facet(__refs) {}
+
+  _LIBCPP_HIDE_FROM_ABI result
+  out(state_type& __st,
+      const intern_type* __frm,
+      const intern_type* __frm_end,
+      const intern_type*& __frm_nxt,
+      extern_type* __to,
+      extern_type* __to_end,
+      extern_type*& __to_nxt) const {
+    return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const {
+    return do_unshift(__st, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  in(state_type& __st,
+     const extern_type* __frm,
+     const extern_type* __frm_end,
+     const extern_type*& __frm_nxt,
+     intern_type* __to,
+     intern_type* __to_end,
+     intern_type*& __to_nxt) const {
+    return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int encoding() const _NOEXCEPT { return do_encoding(); }
+
+  _LIBCPP_HIDE_FROM_ABI bool always_noconv() const _NOEXCEPT { return do_always_noconv(); }
+
+  _LIBCPP_HIDE_FROM_ABI int
+  length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const {
+    return do_length(__st, __frm, __end, __mx);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int max_length() const _NOEXCEPT { return do_max_length(); }
+
+  static locale::id id;
+
+protected:
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(const char*, size_t __refs = 0) : locale::facet(__refs) {}
+
+  ~codecvt() override;
+
+  virtual result
+  do_out(state_type& __st,
+         const intern_type* __frm,
+         const intern_type* __frm_end,
+         const intern_type*& __frm_nxt,
+         extern_type* __to,
+         extern_type* __to_end,
+         extern_type*& __to_nxt) const;
+  virtual result
+  do_in(state_type& __st,
+        const extern_type* __frm,
+        const extern_type* __frm_end,
+        const extern_type*& __frm_nxt,
+        intern_type* __to,
+        intern_type* __to_end,
+        intern_type*& __to_nxt) const;
+  virtual result do_unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+  virtual int do_encoding() const _NOEXCEPT;
+  virtual bool do_always_noconv() const _NOEXCEPT;
+  virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+  virtual int do_max_length() const _NOEXCEPT;
+};
+
+#  if _LIBCPP_HAS_CHAR8_T
+
+// template <> class codecvt<char16_t, char8_t, mbstate_t> // C++20
+
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI codecvt<char16_t, char8_t, mbstate_t> : public locale::facet, public codecvt_base {
+public:
+  typedef char16_t intern_type;
+  typedef char8_t extern_type;
+  typedef mbstate_t state_type;
+
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(size_t __refs = 0) : locale::facet(__refs) {}
+
+  _LIBCPP_HIDE_FROM_ABI result
+  out(state_type& __st,
+      const intern_type* __frm,
+      const intern_type* __frm_end,
+      const intern_type*& __frm_nxt,
+      extern_type* __to,
+      extern_type* __to_end,
+      extern_type*& __to_nxt) const {
+    return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const {
+    return do_unshift(__st, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  in(state_type& __st,
+     const extern_type* __frm,
+     const extern_type* __frm_end,
+     const extern_type*& __frm_nxt,
+     intern_type* __to,
+     intern_type* __to_end,
+     intern_type*& __to_nxt) const {
+    return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int encoding() const _NOEXCEPT { return do_encoding(); }
+
+  _LIBCPP_HIDE_FROM_ABI bool always_noconv() const _NOEXCEPT { return do_always_noconv(); }
+
+  _LIBCPP_HIDE_FROM_ABI int
+  length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const {
+    return do_length(__st, __frm, __end, __mx);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int max_length() const _NOEXCEPT { return do_max_length(); }
+
+  static locale::id id;
+
+protected:
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(const char*, size_t __refs = 0) : locale::facet(__refs) {}
+
+  ~codecvt() override;
+
+  virtual result
+  do_out(state_type& __st,
+         const intern_type* __frm,
+         const intern_type* __frm_end,
+         const intern_type*& __frm_nxt,
+         extern_type* __to,
+         extern_type* __to_end,
+         extern_type*& __to_nxt) const;
+  virtual result
+  do_in(state_type& __st,
+        const extern_type* __frm,
+        const extern_type* __frm_end,
+        const extern_type*& __frm_nxt,
+        intern_type* __to,
+        intern_type* __to_end,
+        intern_type*& __to_nxt) const;
+  virtual result do_unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+  virtual int do_encoding() const _NOEXCEPT;
+  virtual bool do_always_noconv() const _NOEXCEPT;
+  virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+  virtual int do_max_length() const _NOEXCEPT;
+};
+
+#  endif
+
+// template <> class codecvt<char32_t, char, mbstate_t> // deprecated in C++20
+
+template <>
+class _LIBCPP_DEPRECATED_IN_CXX20 _LIBCPP_EXPORTED_FROM_ABI codecvt<char32_t, char, mbstate_t>
+    : public locale::facet, public codecvt_base {
+public:
+  typedef char32_t intern_type;
+  typedef char extern_type;
+  typedef mbstate_t state_type;
+
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(size_t __refs = 0) : locale::facet(__refs) {}
+
+  _LIBCPP_HIDE_FROM_ABI result
+  out(state_type& __st,
+      const intern_type* __frm,
+      const intern_type* __frm_end,
+      const intern_type*& __frm_nxt,
+      extern_type* __to,
+      extern_type* __to_end,
+      extern_type*& __to_nxt) const {
+    return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const {
+    return do_unshift(__st, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  in(state_type& __st,
+     const extern_type* __frm,
+     const extern_type* __frm_end,
+     const extern_type*& __frm_nxt,
+     intern_type* __to,
+     intern_type* __to_end,
+     intern_type*& __to_nxt) const {
+    return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int encoding() const _NOEXCEPT { return do_encoding(); }
+
+  _LIBCPP_HIDE_FROM_ABI bool always_noconv() const _NOEXCEPT { return do_always_noconv(); }
+
+  _LIBCPP_HIDE_FROM_ABI int
+  length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const {
+    return do_length(__st, __frm, __end, __mx);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int max_length() const _NOEXCEPT { return do_max_length(); }
+
+  static locale::id id;
+
+protected:
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(const char*, size_t __refs = 0) : locale::facet(__refs) {}
+
+  ~codecvt() override;
+
+  virtual result
+  do_out(state_type& __st,
+         const intern_type* __frm,
+         const intern_type* __frm_end,
+         const intern_type*& __frm_nxt,
+         extern_type* __to,
+         extern_type* __to_end,
+         extern_type*& __to_nxt) const;
+  virtual result
+  do_in(state_type& __st,
+        const extern_type* __frm,
+        const extern_type* __frm_end,
+        const extern_type*& __frm_nxt,
+        intern_type* __to,
+        intern_type* __to_end,
+        intern_type*& __to_nxt) const;
+  virtual result do_unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+  virtual int do_encoding() const _NOEXCEPT;
+  virtual bool do_always_noconv() const _NOEXCEPT;
+  virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+  virtual int do_max_length() const _NOEXCEPT;
+};
+
+#  if _LIBCPP_HAS_CHAR8_T
+
+// template <> class codecvt<char32_t, char8_t, mbstate_t> // C++20
+
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI codecvt<char32_t, char8_t, mbstate_t> : public locale::facet, public codecvt_base {
+public:
+  typedef char32_t intern_type;
+  typedef char8_t extern_type;
+  typedef mbstate_t state_type;
+
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(size_t __refs = 0) : locale::facet(__refs) {}
+
+  _LIBCPP_HIDE_FROM_ABI result
+  out(state_type& __st,
+      const intern_type* __frm,
+      const intern_type* __frm_end,
+      const intern_type*& __frm_nxt,
+      extern_type* __to,
+      extern_type* __to_end,
+      extern_type*& __to_nxt) const {
+    return do_out(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const {
+    return do_unshift(__st, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI result
+  in(state_type& __st,
+     const extern_type* __frm,
+     const extern_type* __frm_end,
+     const extern_type*& __frm_nxt,
+     intern_type* __to,
+     intern_type* __to_end,
+     intern_type*& __to_nxt) const {
+    return do_in(__st, __frm, __frm_end, __frm_nxt, __to, __to_end, __to_nxt);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int encoding() const _NOEXCEPT { return do_encoding(); }
+
+  _LIBCPP_HIDE_FROM_ABI bool always_noconv() const _NOEXCEPT { return do_always_noconv(); }
+
+  _LIBCPP_HIDE_FROM_ABI int
+  length(state_type& __st, const extern_type* __frm, const extern_type* __end, size_t __mx) const {
+    return do_length(__st, __frm, __end, __mx);
+  }
+
+  _LIBCPP_HIDE_FROM_ABI int max_length() const _NOEXCEPT { return do_max_length(); }
+
+  static locale::id id;
+
+protected:
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt(const char*, size_t __refs = 0) : locale::facet(__refs) {}
+
+  ~codecvt() override;
+
+  virtual result
+  do_out(state_type& __st,
+         const intern_type* __frm,
+         const intern_type* __frm_end,
+         const intern_type*& __frm_nxt,
+         extern_type* __to,
+         extern_type* __to_end,
+         extern_type*& __to_nxt) const;
+  virtual result
+  do_in(state_type& __st,
+        const extern_type* __frm,
+        const extern_type* __frm_end,
+        const extern_type*& __frm_nxt,
+        intern_type* __to,
+        intern_type* __to_end,
+        intern_type*& __to_nxt) const;
+  virtual result do_unshift(state_type& __st, extern_type* __to, extern_type* __to_end, extern_type*& __to_nxt) const;
+  virtual int do_encoding() const _NOEXCEPT;
+  virtual bool do_always_noconv() const _NOEXCEPT;
+  virtual int do_length(state_type&, const extern_type* __frm, const extern_type* __end, size_t __mx) const;
+  virtual int do_max_length() const _NOEXCEPT;
+};
+
+#  endif
+
+// template <class _InternT, class _ExternT, class _StateT> class codecvt_byname
+
+template <class _InternT, class _ExternT, class _StateT>
+class codecvt_byname : public codecvt<_InternT, _ExternT, _StateT> {
+public:
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt_byname(const char* __nm, size_t __refs = 0)
+      : codecvt<_InternT, _ExternT, _StateT>(__nm, __refs) {}
+  _LIBCPP_HIDE_FROM_ABI explicit codecvt_byname(const string& __nm, size_t __refs = 0)
+      : codecvt<_InternT, _ExternT, _StateT>(__nm.c_str(), __refs) {}
+
+protected:
+  ~codecvt_byname() override;
+};
+
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
+template <class _InternT, class _ExternT, class _StateT>
+codecvt_byname<_InternT, _ExternT, _StateT>::~codecvt_byname() {}
+_LIBCPP_SUPPRESS_DEPRECATED_POP
+
+extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char, char, mbstate_t>;
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<wchar_t, char, mbstate_t>;
+#  endif
+extern template class _LIBCPP_DEPRECATED_IN_CXX20
+_LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char16_t, char, mbstate_t>; // deprecated in C++20
+extern template class _LIBCPP_DEPRECATED_IN_CXX20
+_LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char32_t, char, mbstate_t>; // deprecated in C++20
+#  if _LIBCPP_HAS_CHAR8_T
+extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char16_t, char8_t, mbstate_t>; // C++20
+extern template class _LIBCPP_EXTERN_TEMPLATE_TYPE_VIS codecvt_byname<char32_t, char8_t, mbstate_t>; // C++20
+#  endif
+
+template <size_t _Np>
+struct __narrow_to_utf8 {
+  template <class _OutputIterator, class _CharT>
+  _OutputIterator operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const;
+};
+
+template <>
+struct __narrow_to_utf8<8> {
+  template <class _OutputIterator, class _CharT>
+  _LIBCPP_HIDE_FROM_ABI _OutputIterator operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const {
+    for (; __wb < __we; ++__wb, ++__s)
+      *__s = *__wb;
+    return __s;
+  }
+};
+
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
+template <>
+struct _LIBCPP_EXPORTED_FROM_ABI __narrow_to_utf8<16> : public codecvt<char16_t, char, mbstate_t> {
+  _LIBCPP_HIDE_FROM_ABI __narrow_to_utf8() : codecvt<char16_t, char, mbstate_t>(1) {}
+  _LIBCPP_SUPPRESS_DEPRECATED_POP
+
+  ~__narrow_to_utf8() override;
+
+  template <class _OutputIterator, class _CharT>
+  _LIBCPP_HIDE_FROM_ABI _OutputIterator operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const {
+    result __r = ok;
+    mbstate_t __mb;
+    while (__wb < __we && __r != error) {
+      const int __sz = 32;
+      char __buf[__sz];
+      char* __bn;
+      const char16_t* __wn = (const char16_t*)__wb;
+      __r = do_out(__mb, (const char16_t*)__wb, (const char16_t*)__we, __wn, __buf, __buf + __sz, __bn);
+      if (__r == codecvt_base::error || __wn == (const char16_t*)__wb)
+        std::__throw_runtime_error("locale not supported");
+      for (const char* __p = __buf; __p < __bn; ++__p, ++__s)
+        *__s = *__p;
+      __wb = (const _CharT*)__wn;
+    }
+    return __s;
+  }
+};
+
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
+template <>
+struct _LIBCPP_EXPORTED_FROM_ABI __narrow_to_utf8<32> : public codecvt<char32_t, char, mbstate_t> {
+  _LIBCPP_HIDE_FROM_ABI __narrow_to_utf8() : codecvt<char32_t, char, mbstate_t>(1) {}
+  _LIBCPP_SUPPRESS_DEPRECATED_POP
+
+  ~__narrow_to_utf8() override;
+
+  template <class _OutputIterator, class _CharT>
+  _LIBCPP_HIDE_FROM_ABI _OutputIterator operator()(_OutputIterator __s, const _CharT* __wb, const _CharT* __we) const {
+    result __r = ok;
+    mbstate_t __mb;
+    while (__wb < __we && __r != error) {
+      const int __sz = 32;
+      char __buf[__sz];
+      char* __bn;
+      const char32_t* __wn = (const char32_t*)__wb;
+      __r = do_out(__mb, (const char32_t*)__wb, (const char32_t*)__we, __wn, __buf, __buf + __sz, __bn);
+      if (__r == codecvt_base::error || __wn == (const char32_t*)__wb)
+        std::__throw_runtime_error("locale not supported");
+      for (const char* __p = __buf; __p < __bn; ++__p, ++__s)
+        *__s = *__p;
+      __wb = (const _CharT*)__wn;
+    }
+    return __s;
+  }
+};
+
+template <size_t _Np>
+struct __widen_from_utf8 {
+  template <class _OutputIterator>
+  _OutputIterator operator()(_OutputIterator __s, const char* __nb, const char* __ne) const;
+};
+
+template <>
+struct __widen_from_utf8<8> {
+  template <class _OutputIterator>
+  _LIBCPP_HIDE_FROM_ABI _OutputIterator operator()(_OutputIterator __s, const char* __nb, const char* __ne) const {
+    for (; __nb < __ne; ++__nb, ++__s)
+      *__s = *__nb;
+    return __s;
+  }
+};
+
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
+template <>
+struct _LIBCPP_EXPORTED_FROM_ABI __widen_from_utf8<16> : public codecvt<char16_t, char, mbstate_t> {
+  _LIBCPP_HIDE_FROM_ABI __widen_from_utf8() : codecvt<char16_t, char, mbstate_t>(1) {}
+  _LIBCPP_SUPPRESS_DEPRECATED_POP
+
+  ~__widen_from_utf8() override;
+
+  template <class _OutputIterator>
+  _LIBCPP_HIDE_FROM_ABI _OutputIterator operator()(_OutputIterator __s, const char* __nb, const char* __ne) const {
+    result __r = ok;
+    mbstate_t __mb;
+    while (__nb < __ne && __r != error) {
+      const int __sz = 32;
+      char16_t __buf[__sz];
+      char16_t* __bn;
+      const char* __nn = __nb;
+      __r              = do_in(__mb, __nb, __ne - __nb > __sz ? __nb + __sz : __ne, __nn, __buf, __buf + __sz, __bn);
+      if (__r == codecvt_base::error || __nn == __nb)
+        std::__throw_runtime_error("locale not supported");
+      for (const char16_t* __p = __buf; __p < __bn; ++__p, ++__s)
+        *__s = *__p;
+      __nb = __nn;
+    }
+    return __s;
+  }
+};
+
+_LIBCPP_SUPPRESS_DEPRECATED_PUSH
+template <>
+struct _LIBCPP_EXPORTED_FROM_ABI __widen_from_utf8<32> : public codecvt<char32_t, char, mbstate_t> {
+  _LIBCPP_HIDE_FROM_ABI __widen_from_utf8() : codecvt<char32_t, char, mbstate_t>(1) {}
+  _LIBCPP_SUPPRESS_DEPRECATED_POP
+
+  ~__widen_from_utf8() override;
+
+  template <class _OutputIterator>
+  _LIBCPP_HIDE_FROM_ABI _OutputIterator operator()(_OutputIterator __s, const char* __nb, const char* __ne) const {
+    result __r = ok;
+    mbstate_t __mb;
+    while (__nb < __ne && __r != error) {
+      const int __sz = 32;
+      char32_t __buf[__sz];
+      char32_t* __bn;
+      const char* __nn = __nb;
+      __r              = do_in(__mb, __nb, __ne - __nb > __sz ? __nb + __sz : __ne, __nn, __buf, __buf + __sz, __bn);
+      if (__r == codecvt_base::error || __nn == __nb)
+        std::__throw_runtime_error("locale not supported");
+      for (const char32_t* __p = __buf; __p < __bn; ++__p, ++__s)
+        *__s = *__p;
+      __nb = __nn;
+    }
+    return __s;
+  }
+};
+
+// template <class charT> class numpunct
+
+template <class _CharT>
+class numpunct;
+
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI numpunct<char> : public locale::facet {
+public:
+  typedef char char_type;
+  typedef basic_string<char_type> string_type;
+
+  explicit numpunct(size_t __refs = 0);
+
+  _LIBCPP_HIDE_FROM_ABI char_type decimal_point() const { return do_decimal_point(); }
+  _LIBCPP_HIDE_FROM_ABI char_type thousands_sep() const { return do_thousands_sep(); }
+  _LIBCPP_HIDE_FROM_ABI string grouping() const { return do_grouping(); }
+  _LIBCPP_HIDE_FROM_ABI string_type truename() const { return do_truename(); }
+  _LIBCPP_HIDE_FROM_ABI string_type falsename() const { return do_falsename(); }
+
+  static locale::id id;
+
+protected:
+  ~numpunct() override;
+  virtual char_type do_decimal_point() const;
+  virtual char_type do_thousands_sep() const;
+  virtual string do_grouping() const;
+  virtual string_type do_truename() const;
+  virtual string_type do_falsename() const;
+
+  char_type __decimal_point_;
+  char_type __thousands_sep_;
+  string __grouping_;
+};
+
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI numpunct<wchar_t> : public locale::facet {
+public:
+  typedef wchar_t char_type;
+  typedef basic_string<char_type> string_type;
+
+  explicit numpunct(size_t __refs = 0);
+
+  _LIBCPP_HIDE_FROM_ABI char_type decimal_point() const { return do_decimal_point(); }
+  _LIBCPP_HIDE_FROM_ABI char_type thousands_sep() const { return do_thousands_sep(); }
+  _LIBCPP_HIDE_FROM_ABI string grouping() const { return do_grouping(); }
+  _LIBCPP_HIDE_FROM_ABI string_type truename() const { return do_truename(); }
+  _LIBCPP_HIDE_FROM_ABI string_type falsename() const { return do_falsename(); }
+
+  static locale::id id;
+
+protected:
+  ~numpunct() override;
+  virtual char_type do_decimal_point() const;
+  virtual char_type do_thousands_sep() const;
+  virtual string do_grouping() const;
+  virtual string_type do_truename() const;
+  virtual string_type do_falsename() const;
+
+  char_type __decimal_point_;
+  char_type __thousands_sep_;
+  string __grouping_;
+};
+#  endif // _LIBCPP_HAS_WIDE_CHARACTERS
+
+// template <class charT> class numpunct_byname
+
+template <class _CharT>
+class numpunct_byname;
+
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI numpunct_byname<char> : public numpunct<char> {
+public:
+  typedef char char_type;
+  typedef basic_string<char_type> string_type;
+
+  explicit numpunct_byname(const char* __nm, size_t __refs = 0);
+  explicit numpunct_byname(const string& __nm, size_t __refs = 0);
+
+protected:
+  ~numpunct_byname() override;
+};
+
+#  if _LIBCPP_HAS_WIDE_CHARACTERS
+template <>
+class _LIBCPP_EXPORTED_FROM_ABI numpunct_byname<wchar_t> : public numpunct<wchar_t> {
+public:
+  typedef wchar_t char_type;
+  typedef basic_string<char_type> string_type;
+
+  explicit numpunct_byname(const char* __nm, size_t __refs = 0);
+  explicit numpunct_byname(const string& __nm, size_t __refs = 0);
+
+protected:
+  ~numpunct_byname() override;
+};
+#  endif // _LIBCPP_HAS_WIDE_CHARACTERS
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_HAS_LOCALIZATION
+
+#endif // _LIBCPP___LOCALE