Gecko [ c.stage.kornherr.net ]

Name	Size	Permission	Date
algorithmfwd.h	24.17 KB	-rw-r--r--	2025-12-18 20:59
align.h	3.62 KB	-rw-r--r--	2025-12-18 20:59
alloc_traits.h	29.53 KB	-rw-r--r--	2025-12-18 20:59
allocated_ptr.h	3.25 KB	-rw-r--r--	2025-12-18 20:59
allocator.h	8.66 KB	-rw-r--r--	2025-12-18 20:59
atomic_base.h	58.7 KB	-rw-r--r--	2025-12-18 20:59
atomic_futex.h	12.08 KB	-rw-r--r--	2025-12-18 20:59
atomic_lockfree_defines.h	2.3 KB	-rw-r--r--	2025-12-18 20:59
atomic_timed_wait.h	13.18 KB	-rw-r--r--	2025-12-18 20:59
atomic_wait.h	12.41 KB	-rw-r--r--	2025-12-18 20:59
basic_ios.h	15.75 KB	-rw-r--r--	2025-12-18 20:59
basic_ios.tcc	5.67 KB	-rw-r--r--	2025-12-18 20:59
basic_string.h	156.46 KB	-rw-r--r--	2025-12-18 20:59
basic_string.tcc	30.3 KB	-rw-r--r--	2025-12-18 20:59
boost_concept_check.h	29.13 KB	-rw-r--r--	2025-12-18 20:59
c++0x_warning.h	1.44 KB	-rw-r--r--	2025-12-18 20:59
char_traits.h	29.05 KB	-rw-r--r--	2025-12-18 20:59
charconv.h	3.58 KB	-rw-r--r--	2025-12-18 20:59
chrono.h	47.06 KB	-rw-r--r--	2025-12-18 20:59
chrono_io.h	76.97 KB	-rw-r--r--	2025-12-18 20:59
codecvt.h	24.9 KB	-rw-r--r--	2025-12-18 20:59
concept_check.h	3.32 KB	-rw-r--r--	2025-12-18 20:59
cow_string.h	130.97 KB	-rw-r--r--	2025-12-18 20:59
cpp_type_traits.h	14.51 KB	-rw-r--r--	2025-12-18 20:59
cxxabi_forced.h	1.77 KB	-rw-r--r--	2025-12-18 20:59
cxxabi_init_exception.h	2.17 KB	-rw-r--r--	2025-12-18 20:59
deque.tcc	41.38 KB	-rw-r--r--	2025-12-18 20:59
enable_special_members.h	12.16 KB	-rw-r--r--	2025-12-18 20:59
erase_if.h	2.09 KB	-rw-r--r--	2025-12-18 20:59
exception.h	2.41 KB	-rw-r--r--	2025-12-18 20:59
exception_defines.h	1.61 KB	-rw-r--r--	2025-12-18 20:59
exception_ptr.h	8.05 KB	-rw-r--r--	2025-12-18 20:59
forward_list.h	49.92 KB	-rw-r--r--	2025-12-18 20:59
forward_list.tcc	13.71 KB	-rw-r--r--	2025-12-18 20:59
fs_dir.h	17.26 KB	-rw-r--r--	2025-12-18 20:59
fs_fwd.h	10.66 KB	-rw-r--r--	2025-12-18 20:59
fs_ops.h	10.49 KB	-rw-r--r--	2025-12-18 20:59
fs_path.h	41.47 KB	-rw-r--r--	2025-12-18 20:59
fstream.tcc	32.64 KB	-rw-r--r--	2025-12-18 20:59
functexcept.h	4.02 KB	-rw-r--r--	2025-12-18 20:59
functional_hash.h	8.79 KB	-rw-r--r--	2025-12-18 20:59
gslice.h	5.39 KB	-rw-r--r--	2025-12-18 20:59
gslice_array.h	7.71 KB	-rw-r--r--	2025-12-18 20:59
hash_bytes.h	2.1 KB	-rw-r--r--	2025-12-18 20:59
hashtable.h	88.71 KB	-rw-r--r--	2025-12-18 20:59
hashtable_policy.h	63.92 KB	-rw-r--r--	2025-12-18 20:59
indirect_array.h	7.72 KB	-rw-r--r--	2025-12-18 20:59
invoke.h	6.08 KB	-rw-r--r--	2025-12-18 20:59
ios_base.h	31.51 KB	-rw-r--r--	2025-12-18 20:59
istream.tcc	31.79 KB	-rw-r--r--	2025-12-18 20:59
iterator_concepts.h	33.72 KB	-rw-r--r--	2025-12-18 20:59
list.tcc	17.63 KB	-rw-r--r--	2025-12-18 20:59
locale_classes.h	24.79 KB	-rw-r--r--	2025-12-18 20:59
locale_classes.tcc	10.61 KB	-rw-r--r--	2025-12-18 20:59
locale_conv.h	18.74 KB	-rw-r--r--	2025-12-18 20:59
locale_facets.h	91.72 KB	-rw-r--r--	2025-12-18 20:59
locale_facets.tcc	40.42 KB	-rw-r--r--	2025-12-18 20:59
locale_facets_nonio.h	69.1 KB	-rw-r--r--	2025-12-18 20:59
locale_facets_nonio.tcc	55.69 KB	-rw-r--r--	2025-12-18 20:59
localefwd.h	5.8 KB	-rw-r--r--	2025-12-18 20:59
mask_array.h	7.77 KB	-rw-r--r--	2025-12-18 20:59
max_size_type.h	22 KB	-rw-r--r--	2025-12-18 20:59
memory_resource.h	15.73 KB	-rw-r--r--	2025-12-18 20:59
memoryfwd.h	2.47 KB	-rw-r--r--	2025-12-18 20:59
mofunc_impl.h	7.45 KB	-rw-r--r--	2025-12-18 20:59
move.h	6.51 KB	-rw-r--r--	2025-12-18 20:59
move_only_function.h	6.12 KB	-rw-r--r--	2025-12-18 20:59
nested_exception.h	7.51 KB	-rw-r--r--	2025-12-18 20:59
new_allocator.h	7.27 KB	-rw-r--r--	2025-12-18 20:59
node_handle.h	11.08 KB	-rw-r--r--	2025-12-18 20:59
ostream.tcc	11.83 KB	-rw-r--r--	2025-12-18 20:59
ostream_insert.h	3.98 KB	-rw-r--r--	2025-12-18 20:59
parse_numbers.h	7.8 KB	-rw-r--r--	2025-12-18 20:59
postypes.h	7.33 KB	-rw-r--r--	2025-12-18 20:59
predefined_ops.h	9.94 KB	-rw-r--r--	2025-12-18 20:59
ptr_traits.h	8.29 KB	-rw-r--r--	2025-12-18 20:59
quoted_string.h	5.01 KB	-rw-r--r--	2025-12-18 20:59
random.h	178.84 KB	-rw-r--r--	2025-12-18 20:59
random.tcc	103.48 KB	-rw-r--r--	2025-12-18 20:59
range_access.h	11.67 KB	-rw-r--r--	2025-12-18 20:59
ranges_algo.h	128.65 KB	-rw-r--r--	2025-12-18 20:59
ranges_algobase.h	18.37 KB	-rw-r--r--	2025-12-18 20:59
ranges_base.h	28.82 KB	-rw-r--r--	2025-12-18 20:59
ranges_cmp.h	5.9 KB	-rw-r--r--	2025-12-18 20:59
ranges_uninitialized.h	17.71 KB	-rw-r--r--	2025-12-18 20:59
ranges_util.h	24.96 KB	-rw-r--r--	2025-12-18 20:59
refwrap.h	13.27 KB	-rw-r--r--	2025-12-18 20:59
regex.h	104.32 KB	-rw-r--r--	2025-12-18 20:59
regex.tcc	16.1 KB	-rw-r--r--	2025-12-18 20:59
regex_automaton.h	10.55 KB	-rw-r--r--	2025-12-18 20:59
regex_automaton.tcc	7.6 KB	-rw-r--r--	2025-12-18 20:59
regex_compiler.h	15.92 KB	-rw-r--r--	2025-12-18 20:59
regex_compiler.tcc	18.48 KB	-rw-r--r--	2025-12-18 20:59
regex_constants.h	14.54 KB	-rw-r--r--	2025-12-18 20:59
regex_error.h	5.35 KB	-rw-r--r--	2025-12-18 20:59
regex_executor.h	8.81 KB	-rw-r--r--	2025-12-18 20:59
regex_executor.tcc	18.49 KB	-rw-r--r--	2025-12-18 20:59
regex_scanner.h	6.88 KB	-rw-r--r--	2025-12-18 20:59
regex_scanner.tcc	14.59 KB	-rw-r--r--	2025-12-18 20:59
requires_hosted.h	1.36 KB	-rw-r--r--	2025-12-18 20:59
semaphore_base.h	7.7 KB	-rw-r--r--	2025-12-18 20:59
shared_ptr.h	38.14 KB	-rw-r--r--	2025-12-18 20:59
shared_ptr_atomic.h	22.79 KB	-rw-r--r--	2025-12-18 20:59
shared_ptr_base.h	65.18 KB	-rw-r--r--	2025-12-18 20:59
slice_array.h	9.39 KB	-rw-r--r--	2025-12-18 20:59
specfun.h	46.07 KB	-rw-r--r--	2025-12-18 20:59
sstream.tcc	9.91 KB	-rw-r--r--	2025-12-18 20:59
std_abs.h	4.63 KB	-rw-r--r--	2025-12-18 20:59
std_function.h	23.12 KB	-rw-r--r--	2025-12-18 20:59
std_mutex.h	6.69 KB	-rw-r--r--	2025-12-18 20:59
std_thread.h	9.84 KB	-rw-r--r--	2025-12-18 20:59
stl_algo.h	212.39 KB	-rw-r--r--	2025-12-18 20:59
stl_algobase.h	74.97 KB	-rw-r--r--	2025-12-18 20:59
stl_bvector.h	41.58 KB	-rw-r--r--	2025-12-18 20:59
stl_construct.h	8.47 KB	-rw-r--r--	2025-12-18 20:59
stl_deque.h	76.34 KB	-rw-r--r--	2025-12-18 20:59
stl_function.h	43.97 KB	-rw-r--r--	2025-12-18 20:59
stl_heap.h	20.31 KB	-rw-r--r--	2025-12-18 20:59
stl_iterator.h	92.81 KB	-rw-r--r--	2025-12-18 20:59
stl_iterator_base_funcs.h	8.75 KB	-rw-r--r--	2025-12-18 20:59
stl_iterator_base_types.h	9.48 KB	-rw-r--r--	2025-12-18 20:59
stl_list.h	70.62 KB	-rw-r--r--	2025-12-18 20:59
stl_map.h	54.86 KB	-rw-r--r--	2025-12-18 20:59
stl_multimap.h	42.71 KB	-rw-r--r--	2025-12-18 20:59
stl_multiset.h	36.87 KB	-rw-r--r--	2025-12-18 20:59
stl_numeric.h	14.25 KB	-rw-r--r--	2025-12-18 20:59
stl_pair.h	36.43 KB	-rw-r--r--	2025-12-18 20:59
stl_queue.h	28.06 KB	-rw-r--r--	2025-12-18 20:59
stl_raw_storage_iter.h	3.91 KB	-rw-r--r--	2025-12-18 20:59
stl_relops.h	4.47 KB	-rw-r--r--	2025-12-18 20:59
stl_set.h	37.13 KB	-rw-r--r--	2025-12-18 20:59
stl_stack.h	13.71 KB	-rw-r--r--	2025-12-18 20:59
stl_tempbuf.h	8.67 KB	-rw-r--r--	2025-12-18 20:59
stl_tree.h	72.06 KB	-rw-r--r--	2025-12-18 20:59
stl_uninitialized.h	35.63 KB	-rw-r--r--	2025-12-18 20:59
stl_vector.h	68.88 KB	-rw-r--r--	2025-12-18 20:59
stream_iterator.h	8.2 KB	-rw-r--r--	2025-12-18 20:59
streambuf.tcc	4.58 KB	-rw-r--r--	2025-12-18 20:59
streambuf_iterator.h	15.57 KB	-rw-r--r--	2025-12-18 20:59
string_view.tcc	7 KB	-rw-r--r--	2025-12-18 20:59
stringfwd.h	2.56 KB	-rw-r--r--	2025-12-18 20:59
this_thread_sleep.h	3.21 KB	-rw-r--r--	2025-12-18 20:59
uniform_int_dist.h	13 KB	-rw-r--r--	2025-12-18 20:59
unique_lock.h	6.16 KB	-rw-r--r--	2025-12-18 20:59
unique_ptr.h	35.62 KB	-rw-r--r--	2025-12-18 20:59
unordered_map.h	75.11 KB	-rw-r--r--	2025-12-18 20:59
unordered_set.h	61.7 KB	-rw-r--r--	2025-12-18 20:59
uses_allocator.h	6.91 KB	-rw-r--r--	2025-12-18 20:59
uses_allocator_args.h	8.53 KB	-rw-r--r--	2025-12-18 20:59
utility.h	8.12 KB	-rw-r--r--	2025-12-18 20:59
valarray_after.h	22.74 KB	-rw-r--r--	2025-12-18 20:59
valarray_array.h	20.8 KB	-rw-r--r--	2025-12-18 20:59
valarray_array.tcc	7.08 KB	-rw-r--r--	2025-12-18 20:59
valarray_before.h	18.69 KB	-rw-r--r--	2025-12-18 20:59
vector.tcc	31.5 KB	-rw-r--r--	2025-12-18 20:59

Rename

// Character Traits for use by standard string and iostream -*- C++ -*-

// Copyright (C) 1997-2023 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library.  This library is free
// software; you can redistribute it and/or modify it under the
// terms of the GNU General Public License as published by the
// Free Software Foundation; either version 3, or (at your option)
// any later version.

// This library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.

// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.

// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
// <http://www.gnu.org/licenses/>.

/** @file bits/char_traits.h
 *  This is an internal header file, included by other library headers.
 *  Do not attempt to use it directly. @headername{string}
 */

//
// ISO C++ 14882: 21  Strings library
//

#ifndef _CHAR_TRAITS_H
#define _CHAR_TRAITS_H 1

#pragma GCC system_header

#include <bits/c++config.h>

#if _GLIBCXX_HOSTED
# include <bits/postypes.h>     // For streampos
#endif // HOSTED

#ifdef _GLIBCXX_USE_WCHAR_T
# include <cwchar>              // For WEOF, wmemmove, wmemset, etc.
#endif // USE_WCHAR_T

#if __cplusplus >= 201103L
# include <type_traits>
#if !defined __UINT_LEAST16_TYPE__ || !defined __UINT_LEAST32_TYPE__
# include <cstdint>
#endif
#endif
#if __cplusplus >= 202002L
# include <compare>
# include <bits/stl_construct.h>
#endif

#ifndef _GLIBCXX_ALWAYS_INLINE
# define _GLIBCXX_ALWAYS_INLINE inline __attribute__((__always_inline__))
#endif

namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstringop-overflow"
#pragma GCC diagnostic ignored "-Wstringop-overread"
#pragma GCC diagnostic ignored "-Warray-bounds"

/**
   *  @brief  Mapping from character type to associated types.
   *
   *  @note This is an implementation class for the generic version
   *  of char_traits.  It defines int_type, off_type, pos_type, and
   *  state_type.  By default these are unsigned long, streamoff,
   *  streampos, and mbstate_t.  Users who need a different set of
   *  types, but who don't need to change the definitions of any function
   *  defined in char_traits, can specialize __gnu_cxx::_Char_types
   *  while leaving __gnu_cxx::char_traits alone. */
  template<typename _CharT>
    struct _Char_types
    {
      typedef unsigned long   int_type;
#if _GLIBCXX_HOSTED
      typedef std::streampos  pos_type;
      typedef std::streamoff  off_type;
      typedef std::mbstate_t  state_type;
#endif // HOSTED
    };

/**
   *  @brief  Base class used to implement std::char_traits.
   *
   *  @note For any given actual character type, this definition is
   *  probably wrong.  (Most of the member functions are likely to be
   *  right, but the int_type and state_type typedefs, and the eof()
   *  member function, are likely to be wrong.)  The reason this class
   *  exists is so users can specialize it.  Classes in namespace std
   *  may not be specialized for fundamental types, but classes in
   *  namespace __gnu_cxx may be.
   *
   *  See https://gcc.gnu.org/onlinedocs/libstdc++/manual/strings.html#strings.string.character_types
   *  for advice on how to make use of this class for @a unusual character
   *  types. Also, check out include/ext/pod_char_traits.h.  
   */
  template<typename _CharT>
    struct char_traits
    {
      typedef _CharT                                    char_type;
      typedef typename _Char_types<_CharT>::int_type    int_type;
#if _GLIBCXX_HOSTED
      typedef typename _Char_types<_CharT>::pos_type    pos_type;
      typedef typename _Char_types<_CharT>::off_type    off_type;
      typedef typename _Char_types<_CharT>::state_type  state_type;
#endif // HOSTED
#if __cpp_lib_three_way_comparison
      using comparison_category = std::strong_ordering;
#endif

static _GLIBCXX14_CONSTEXPR void
      assign(char_type& __c1, const char_type& __c2)
      {
#if __cpp_constexpr_dynamic_alloc
	if (std::__is_constant_evaluated())
	  std::construct_at(__builtin_addressof(__c1), __c2);
	else
#endif
	__c1 = __c2;
      }

static _GLIBCXX_CONSTEXPR bool
      eq(const char_type& __c1, const char_type& __c2)
      { return __c1 == __c2; }

static _GLIBCXX_CONSTEXPR bool
      lt(const char_type& __c1, const char_type& __c2)
      { return __c1 < __c2; }

static _GLIBCXX14_CONSTEXPR int
      compare(const char_type* __s1, const char_type* __s2, std::size_t __n);

static _GLIBCXX14_CONSTEXPR std::size_t
      length(const char_type* __s);

static _GLIBCXX14_CONSTEXPR const char_type*
      find(const char_type* __s, std::size_t __n, const char_type& __a);

static _GLIBCXX20_CONSTEXPR char_type*
      move(char_type* __s1, const char_type* __s2, std::size_t __n);

static _GLIBCXX20_CONSTEXPR char_type*
      copy(char_type* __s1, const char_type* __s2, std::size_t __n);

static _GLIBCXX20_CONSTEXPR char_type*
      assign(char_type* __s, std::size_t __n, char_type __a);

static _GLIBCXX_CONSTEXPR char_type
      to_char_type(const int_type& __c)
      { return static_cast<char_type>(__c); }

static _GLIBCXX_CONSTEXPR int_type
      to_int_type(const char_type& __c)
      { return static_cast<int_type>(__c); }

static _GLIBCXX_CONSTEXPR bool
      eq_int_type(const int_type& __c1, const int_type& __c2)
      { return __c1 == __c2; }

#ifdef _GLIBCXX_STDIO_EOF
      static _GLIBCXX_CONSTEXPR int_type
      eof()
      { return static_cast<int_type>(_GLIBCXX_STDIO_EOF); }

static _GLIBCXX_CONSTEXPR int_type
      not_eof(const int_type& __c)
      { return !eq_int_type(__c, eof()) ? __c : to_int_type(char_type()); }
#endif // defined(_GLIBCXX_STDIO_EOF)
    };

template<typename _CharT>
    _GLIBCXX14_CONSTEXPR int
    char_traits<_CharT>::
    compare(const char_type* __s1, const char_type* __s2, std::size_t __n)
    {
      for (std::size_t __i = 0; __i < __n; ++__i)
	if (lt(__s1[__i], __s2[__i]))
	  return -1;
	else if (lt(__s2[__i], __s1[__i]))
	  return 1;
      return 0;
    }

template<typename _CharT>
    _GLIBCXX14_CONSTEXPR std::size_t
    char_traits<_CharT>::
    length(const char_type* __p)
    {
      std::size_t __i = 0;
      while (!eq(__p[__i], char_type()))
        ++__i;
      return __i;
    }

template<typename _CharT>
    _GLIBCXX14_CONSTEXPR const typename char_traits<_CharT>::char_type*
    char_traits<_CharT>::
    find(const char_type* __s, std::size_t __n, const char_type& __a)
    {
      for (std::size_t __i = 0; __i < __n; ++__i)
        if (eq(__s[__i], __a))
          return __s + __i;
      return 0;
    }

template<typename _CharT>
    _GLIBCXX20_CONSTEXPR
    typename char_traits<_CharT>::char_type*
    char_traits<_CharT>::
    move(char_type* __s1, const char_type* __s2, std::size_t __n)
    {
      if (__n == 0)
	return __s1;
#if __cplusplus >= 202002L
      if (std::__is_constant_evaluated())
	{
	  // Use __builtin_constant_p to avoid comparing unrelated pointers.
	  if (__builtin_constant_p(__s2 < __s1)
		&& __s1 > __s2 && __s1 < (__s2 + __n))
	    {
	      do
		{
		  --__n;
		  assign(__s1[__n], __s2[__n]);
		}
	      while (__n > 0);
	    }
	  else
	    copy(__s1, __s2, __n);
	  return __s1;
	}
#endif
      __builtin_memmove(__s1, __s2, __n * sizeof(char_type));
      return __s1;
    }

template<typename _CharT>
    _GLIBCXX20_CONSTEXPR
    typename char_traits<_CharT>::char_type*
    char_traits<_CharT>::
    copy(char_type* __s1, const char_type* __s2, std::size_t __n)
    {
      if (__n == 0)
	return __s1;
#if __cplusplus >= 202002L
      if (std::__is_constant_evaluated())
	{
	  for (std::size_t __i = 0; __i < __n; ++__i)
	    std::construct_at(__s1 + __i, __s2[__i]);
	  return __s1;
	}
#endif
      __builtin_memcpy(__s1, __s2, __n * sizeof(char_type));
      return __s1;
    }

template<typename _CharT>
    _GLIBCXX20_CONSTEXPR
    typename char_traits<_CharT>::char_type*
    char_traits<_CharT>::
    assign(char_type* __s, std::size_t __n, char_type __a)
    {
#if __cplusplus >= 202002L
      if (std::__is_constant_evaluated())
	{
	  for (std::size_t __i = 0; __i < __n; ++__i)
	    std::construct_at(__s + __i, __a);
	  return __s;
	}
#endif

if _GLIBCXX17_CONSTEXPR (sizeof(_CharT) == 1 && __is_trivial(_CharT))
	{
	  if (__n)
	    {
	      unsigned char __c;
	      __builtin_memcpy(&__c, __builtin_addressof(__a), 1);
	      __builtin_memset(__s, __c, __n);
	    }
	}
      else
	{
	  for (std::size_t __i = 0; __i < __n; ++__i)
	    __s[__i] = __a;
	}
      return __s;
    }

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

#ifdef __cpp_lib_is_constant_evaluated
// Unofficial macro indicating P1032R1 support in C++20
# define __cpp_lib_constexpr_char_traits 201811L
#elif __cplusplus >= 201703L && _GLIBCXX_HAVE_IS_CONSTANT_EVALUATED
// Unofficial macro indicating P0426R1 support in C++17
# define __cpp_lib_constexpr_char_traits 201611L
#endif

// 21.1
  /**
   *  @brief  Basis for explicit traits specializations.
   *
   *  @note  For any given actual character type, this definition is
   *  probably wrong.  Since this is just a thin wrapper around
   *  __gnu_cxx::char_traits, it is possible to achieve a more
   *  appropriate definition by specializing __gnu_cxx::char_traits.
   *
   *  See https://gcc.gnu.org/onlinedocs/libstdc++/manual/strings.html#strings.string.character_types
   *  for advice on how to make use of this class for @a unusual character
   *  types. Also, check out include/ext/pod_char_traits.h.
  */
  template<typename _CharT>
    struct char_traits : public __gnu_cxx::char_traits<_CharT>
    { };

/// 21.1.3.1  char_traits specializations
  template<>
    struct char_traits<char>
    {
      typedef char              char_type;
      typedef int               int_type;
#if _GLIBCXX_HOSTED
      typedef streampos         pos_type;
      typedef streamoff         off_type;
      typedef mbstate_t         state_type;
#endif // HOSTED
#if __cpp_lib_three_way_comparison
      using comparison_category = strong_ordering;
#endif

static _GLIBCXX17_CONSTEXPR void
      assign(char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
      {
#if __cpp_constexpr_dynamic_alloc
	if (std::__is_constant_evaluated())
	  std::construct_at(__builtin_addressof(__c1), __c2);
	else
#endif
	__c1 = __c2;
      }

static _GLIBCXX_CONSTEXPR bool
      eq(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
      { return __c1 == __c2; }

static _GLIBCXX_CONSTEXPR bool
      lt(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
      {
	// LWG 467.
	return (static_cast<unsigned char>(__c1)
		< static_cast<unsigned char>(__c2));
      }

static _GLIBCXX17_CONSTEXPR int
      compare(const char_type* __s1, const char_type* __s2, size_t __n)
      {
	if (__n == 0)
	  return 0;
#if __cplusplus >= 201703L
	if (std::__is_constant_evaluated())
	  {
	    for (size_t __i = 0; __i < __n; ++__i)
	      if (lt(__s1[__i], __s2[__i]))
		return -1;
	      else if (lt(__s2[__i], __s1[__i]))
		return 1;
	    return 0;
	  }
#endif
	return __builtin_memcmp(__s1, __s2, __n);
      }

static _GLIBCXX17_CONSTEXPR size_t
      length(const char_type* __s)
      {
#if __cplusplus >= 201703L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::length(__s);
#endif
	return __builtin_strlen(__s);
      }

static _GLIBCXX17_CONSTEXPR const char_type*
      find(const char_type* __s, size_t __n, const char_type& __a)
      {
	if (__n == 0)
	  return 0;
#if __cplusplus >= 201703L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::find(__s, __n, __a);
#endif
	return static_cast<const char_type*>(__builtin_memchr(__s, __a, __n));
      }

static _GLIBCXX20_CONSTEXPR char_type*
      move(char_type* __s1, const char_type* __s2, size_t __n)
      {
	if (__n == 0)
	  return __s1;
#if __cplusplus >= 202002L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::move(__s1, __s2, __n);
#endif
	return static_cast<char_type*>(__builtin_memmove(__s1, __s2, __n));
      }

static _GLIBCXX20_CONSTEXPR char_type*
      copy(char_type* __s1, const char_type* __s2, size_t __n)
      {
	if (__n == 0)
	  return __s1;
#if __cplusplus >= 202002L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::copy(__s1, __s2, __n);
#endif
	return static_cast<char_type*>(__builtin_memcpy(__s1, __s2, __n));
      }

static _GLIBCXX20_CONSTEXPR char_type*
      assign(char_type* __s, size_t __n, char_type __a)
      {
	if (__n == 0)
	  return __s;
#if __cplusplus >= 202002L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::assign(__s, __n, __a);
#endif
	return static_cast<char_type*>(__builtin_memset(__s, __a, __n));
      }

static _GLIBCXX_CONSTEXPR char_type
      to_char_type(const int_type& __c) _GLIBCXX_NOEXCEPT
      { return static_cast<char_type>(__c); }

// To keep both the byte 0xff and the eof symbol 0xffffffff
      // from ending up as 0xffffffff.
      static _GLIBCXX_CONSTEXPR int_type
      to_int_type(const char_type& __c) _GLIBCXX_NOEXCEPT
      { return static_cast<int_type>(static_cast<unsigned char>(__c)); }

static _GLIBCXX_CONSTEXPR bool
      eq_int_type(const int_type& __c1, const int_type& __c2) _GLIBCXX_NOEXCEPT
      { return __c1 == __c2; }

#ifdef _GLIBCXX_STDIO_EOF
      static _GLIBCXX_CONSTEXPR int_type
      eof() _GLIBCXX_NOEXCEPT
      { return static_cast<int_type>(_GLIBCXX_STDIO_EOF); }

static _GLIBCXX_CONSTEXPR int_type
      not_eof(const int_type& __c) _GLIBCXX_NOEXCEPT
      { return (__c == eof()) ? 0 : __c; }
#endif // defined(_GLIBCXX_STDIO_EOF)
  };

#ifdef _GLIBCXX_USE_WCHAR_T
  /// 21.1.3.2  char_traits specializations
  template<>
    struct char_traits<wchar_t>
    {
      typedef wchar_t           char_type;
      typedef wint_t            int_type;
#if _GLIBCXX_HOSTED
      typedef streamoff         off_type;
      typedef wstreampos        pos_type;
      typedef mbstate_t         state_type;
#endif // HOSTED
#if __cpp_lib_three_way_comparison
      using comparison_category = strong_ordering;
#endif

static _GLIBCXX_CONSTEXPR bool
      eq(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
      { return __c1 == __c2; }

static _GLIBCXX_CONSTEXPR bool
      lt(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
      { return __c1 < __c2; }

static _GLIBCXX17_CONSTEXPR int
      compare(const char_type* __s1, const char_type* __s2, size_t __n)
      {
	if (__n == 0)
	  return 0;
#if __cplusplus >= 201703L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::compare(__s1, __s2, __n);
#endif
	return wmemcmp(__s1, __s2, __n);
      }

static _GLIBCXX_CONSTEXPR char_type
      to_char_type(const int_type& __c) _GLIBCXX_NOEXCEPT
      { return char_type(__c); }

static _GLIBCXX_CONSTEXPR int_type
      to_int_type(const char_type& __c) _GLIBCXX_NOEXCEPT
      { return int_type(__c); }

static _GLIBCXX_CONSTEXPR bool
      eq_int_type(const int_type& __c1, const int_type& __c2) _GLIBCXX_NOEXCEPT
      { return __c1 == __c2; }

#if _GLIBCXX_HOSTED
      static _GLIBCXX_CONSTEXPR int_type
      eof() _GLIBCXX_NOEXCEPT
      { return static_cast<int_type>(WEOF); }

static _GLIBCXX_CONSTEXPR int_type
      not_eof(const int_type& __c) _GLIBCXX_NOEXCEPT
      { return eq_int_type(__c, eof()) ? 0 : __c; }
#endif // HOSTED
  };
#else // _GLIBCXX_USE_WCHAR_T
  template<>
    struct char_traits<wchar_t> : public __gnu_cxx::char_traits<wchar_t>
    { };
#endif //_GLIBCXX_USE_WCHAR_T

#ifdef _GLIBCXX_USE_CHAR8_T
  template<>
    struct char_traits<char8_t>
    {
      typedef char8_t           char_type;
      typedef unsigned int      int_type;
#if _GLIBCXX_HOSTED
      typedef u8streampos       pos_type;
      typedef streamoff         off_type;
      typedef mbstate_t         state_type;
#endif // HOSTED
#if __cpp_lib_three_way_comparison
      using comparison_category = strong_ordering;
#endif

static _GLIBCXX_CONSTEXPR bool
      eq(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
      { return __c1 == __c2; }

static _GLIBCXX_CONSTEXPR bool
      lt(const char_type& __c1, const char_type& __c2) _GLIBCXX_NOEXCEPT
      { return __c1 < __c2; }

static _GLIBCXX17_CONSTEXPR int
      compare(const char_type* __s1, const char_type* __s2, size_t __n)
      {
	if (__n == 0)
	  return 0;
#if __cplusplus >= 201703L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::compare(__s1, __s2, __n);
#endif
	return __builtin_memcmp(__s1, __s2, __n);
      }

static _GLIBCXX_CONSTEXPR char_type
      to_char_type(const int_type& __c) _GLIBCXX_NOEXCEPT
      { return char_type(__c); }

static _GLIBCXX_CONSTEXPR int_type
      to_int_type(const char_type& __c) _GLIBCXX_NOEXCEPT
      { return int_type(__c); }

static _GLIBCXX_CONSTEXPR bool
      eq_int_type(const int_type& __c1, const int_type& __c2) _GLIBCXX_NOEXCEPT
      { return __c1 == __c2; }

#if _GLIBCXX_HOSTED
      static _GLIBCXX_CONSTEXPR int_type
      eof() _GLIBCXX_NOEXCEPT
      { return static_cast<int_type>(-1); }

static _GLIBCXX_CONSTEXPR int_type
      not_eof(const int_type& __c) _GLIBCXX_NOEXCEPT
      { return eq_int_type(__c, eof()) ? 0 : __c; }
#endif // HOSTED
    };
#endif //_GLIBCXX_USE_CHAR8_T

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#if __cplusplus >= 201103L

namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

template<>
    struct char_traits<char16_t>
    {
      typedef char16_t          char_type;
#ifdef __UINT_LEAST16_TYPE__
      typedef __UINT_LEAST16_TYPE__	    int_type;
#elif defined _GLIBCXX_USE_C99_STDINT_TR1
      typedef uint_least16_t    int_type;
#else
      typedef make_unsigned<char16_t>::type int_type;
#endif
#if _GLIBCXX_HOSTED
      typedef streamoff         off_type;
      typedef u16streampos      pos_type;
      typedef mbstate_t         state_type;
#endif // HOSTED
#if __cpp_lib_three_way_comparison
      using comparison_category = strong_ordering;
#endif

static _GLIBCXX17_CONSTEXPR void
      assign(char_type& __c1, const char_type& __c2) noexcept
      {
#if __cpp_constexpr_dynamic_alloc
	if (std::__is_constant_evaluated())
	  std::construct_at(__builtin_addressof(__c1), __c2);
	else
#endif
	__c1 = __c2;
      }

static constexpr bool
      eq(const char_type& __c1, const char_type& __c2) noexcept
      { return __c1 == __c2; }

static constexpr bool
      lt(const char_type& __c1, const char_type& __c2) noexcept
      { return __c1 < __c2; }

static _GLIBCXX17_CONSTEXPR int
      compare(const char_type* __s1, const char_type* __s2, size_t __n)
      {
	for (size_t __i = 0; __i < __n; ++__i)
	  if (lt(__s1[__i], __s2[__i]))
	    return -1;
	  else if (lt(__s2[__i], __s1[__i]))
	    return 1;
	return 0;
      }

static _GLIBCXX17_CONSTEXPR size_t
      length(const char_type* __s)
      {
	size_t __i = 0;
	while (!eq(__s[__i], char_type()))
	  ++__i;
	return __i;
      }

static _GLIBCXX17_CONSTEXPR const char_type*
      find(const char_type* __s, size_t __n, const char_type& __a)
      {
	for (size_t __i = 0; __i < __n; ++__i)
	  if (eq(__s[__i], __a))
	    return __s + __i;
	return 0;
      }

static _GLIBCXX20_CONSTEXPR char_type*
      move(char_type* __s1, const char_type* __s2, size_t __n)
      {
	if (__n == 0)
	  return __s1;
#if __cplusplus >= 202002L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::move(__s1, __s2, __n);
#endif
	return (static_cast<char_type*>
		(__builtin_memmove(__s1, __s2, __n * sizeof(char_type))));
      }

static _GLIBCXX20_CONSTEXPR char_type*
      copy(char_type* __s1, const char_type* __s2, size_t __n)
      {
	if (__n == 0)
	  return __s1;
#if __cplusplus >= 202002L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::copy(__s1, __s2, __n);
#endif
	return (static_cast<char_type*>
		(__builtin_memcpy(__s1, __s2, __n * sizeof(char_type))));
      }

static _GLIBCXX20_CONSTEXPR char_type*
      assign(char_type* __s, size_t __n, char_type __a)
      {
	for (size_t __i = 0; __i < __n; ++__i)
	  assign(__s[__i], __a);
	return __s;
      }

static constexpr char_type
      to_char_type(const int_type& __c) noexcept
      { return char_type(__c); }

static constexpr bool
      eq_int_type(const int_type& __c1, const int_type& __c2) noexcept
      { return __c1 == __c2; }

#if _GLIBCXX_HOSTED
      static constexpr int_type
      to_int_type(const char_type& __c) noexcept
      { return __c == eof() ? int_type(0xfffd) : int_type(__c); }

static constexpr int_type
      eof() noexcept
      { return static_cast<int_type>(-1); }

static constexpr int_type
      not_eof(const int_type& __c) noexcept
      { return eq_int_type(__c, eof()) ? 0 : __c; }
#else // !HOSTED
      static constexpr int_type
      to_int_type(const char_type& __c) noexcept
      { return int_type(__c); }
#endif // !HOSTED
    };

template<>
    struct char_traits<char32_t>
    {
      typedef char32_t          char_type;
#ifdef __UINT_LEAST32_TYPE__
      typedef __UINT_LEAST32_TYPE__	    int_type;
#elif defined _GLIBCXX_USE_C99_STDINT_TR1
      typedef uint_least32_t    int_type;
#else
      typedef make_unsigned<char32_t>::type int_type;
#endif
#if _GLIBCXX_HOSTED
      typedef streamoff         off_type;
      typedef u32streampos      pos_type;
      typedef mbstate_t         state_type;
#endif // HOSTED
#if __cpp_lib_three_way_comparison
      using comparison_category = strong_ordering;
#endif

static constexpr bool
      eq(const char_type& __c1, const char_type& __c2) noexcept
      { return __c1 == __c2; }

static constexpr bool
      lt(const char_type& __c1, const char_type& __c2) noexcept
      { return __c1 < __c2; }

static _GLIBCXX17_CONSTEXPR size_t
      length(const char_type* __s)
      {
	size_t __i = 0;
	while (!eq(__s[__i], char_type()))
	  ++__i;
	return __i;
      }

static _GLIBCXX20_CONSTEXPR char_type*
      move(char_type* __s1, const char_type* __s2, size_t __n)
      {
	if (__n == 0)
	  return __s1;
#if __cplusplus >= 202002L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::move(__s1, __s2, __n);
#endif
	return (static_cast<char_type*>
		(__builtin_memmove(__s1, __s2, __n * sizeof(char_type))));
      }

static _GLIBCXX20_CONSTEXPR char_type*
      copy(char_type* __s1, const char_type* __s2, size_t __n)
      { 
	if (__n == 0)
	  return __s1;
#if __cplusplus >= 202002L
	if (std::__is_constant_evaluated())
	  return __gnu_cxx::char_traits<char_type>::copy(__s1, __s2, __n);
#endif
	return (static_cast<char_type*>
		(__builtin_memcpy(__s1, __s2, __n * sizeof(char_type))));
      }

static _GLIBCXX20_CONSTEXPR char_type*
      assign(char_type* __s, size_t __n, char_type __a)
      {
	for (size_t __i = 0; __i < __n; ++__i)
	  assign(__s[__i], __a);
	return __s;
      }

static constexpr char_type
      to_char_type(const int_type& __c) noexcept
      { return char_type(__c); }

static constexpr int_type
      to_int_type(const char_type& __c) noexcept
      { return int_type(__c); }

static constexpr bool
      eq_int_type(const int_type& __c1, const int_type& __c2) noexcept
      { return __c1 == __c2; }

#if _GLIBCXX_HOSTED
      static constexpr int_type
      eof() noexcept
      { return static_cast<int_type>(-1); }

static constexpr int_type
      not_eof(const int_type& __c) noexcept
      { return eq_int_type(__c, eof()) ? 0 : __c; }
#endif // HOSTED
    };

#if __cpp_lib_three_way_comparison
  namespace __detail
  {
    template<typename _ChTraits>
      constexpr auto
      __char_traits_cmp_cat(int __cmp) noexcept
      {
	if constexpr (requires { typename _ChTraits::comparison_category; })
	  {
	    using _Cat = typename _ChTraits::comparison_category;
	    static_assert( !is_void_v<common_comparison_category_t<_Cat>> );
	    return static_cast<_Cat>(__cmp <=> 0);
	  }
	else
	  return static_cast<weak_ordering>(__cmp <=> 0);
      }
  } // namespace __detail
#endif // C++20

#pragma GCC diagnostic pop

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace

#endif  // C++11

#endif // _CHAR_TRAITS_H