1//===----------------------------------------------------------------------===//
  2//
  3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  4// See https://llvm.org/LICENSE.txt for license information.
  5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  6//
  7//===----------------------------------------------------------------------===//
  8
  9#ifndef _LIBCPP___FWD_STRING_H
 10#define _LIBCPP___FWD_STRING_H
 11
 12#include <__config>
 13#include <__fwd/memory.h>
 14#include <__fwd/memory_resource.h>
 15
 16#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 17#  pragma GCC system_header
 18#endif
 19
 20_LIBCPP_BEGIN_NAMESPACE_STD
 21
 22template <class _CharT>
 23struct char_traits;
 24template <>
 25struct char_traits<char>;
 26
 27#if _LIBCPP_HAS_CHAR8_T
 28template <>
 29struct char_traits<char8_t>;
 30#endif
 31
 32template <>
 33struct char_traits<char16_t>;
 34template <>
 35struct char_traits<char32_t>;
 36
 37#if _LIBCPP_HAS_WIDE_CHARACTERS
 38template <>
 39struct char_traits<wchar_t>;
 40#endif
 41
 42template <class _CharT, class _Traits = char_traits<_CharT>, class _Allocator = allocator<_CharT> >
 43class basic_string;
 44
 45using string = basic_string<char>;
 46
 47#if _LIBCPP_HAS_WIDE_CHARACTERS
 48using wstring = basic_string<wchar_t>;
 49#endif
 50
 51#if _LIBCPP_HAS_CHAR8_T
 52using u8string = basic_string<char8_t>;
 53#endif
 54
 55using u16string = basic_string<char16_t>;
 56using u32string = basic_string<char32_t>;
 57
 58#if _LIBCPP_STD_VER >= 17
 59
 60namespace pmr {
 61template <class _CharT, class _Traits = char_traits<_CharT>>
 62using basic_string _LIBCPP_AVAILABILITY_PMR = std::basic_string<_CharT, _Traits, polymorphic_allocator<_CharT>>;
 63
 64using string _LIBCPP_AVAILABILITY_PMR = basic_string<char>;
 65
 66#  if _LIBCPP_HAS_WIDE_CHARACTERS
 67using wstring _LIBCPP_AVAILABILITY_PMR = basic_string<wchar_t>;
 68#  endif
 69
 70#  if _LIBCPP_HAS_CHAR8_T
 71using u8string _LIBCPP_AVAILABILITY_PMR = basic_string<char8_t>;
 72#  endif
 73
 74using u16string _LIBCPP_AVAILABILITY_PMR = basic_string<char16_t>;
 75using u32string _LIBCPP_AVAILABILITY_PMR = basic_string<char32_t>;
 76} // namespace pmr
 77
 78#endif // _LIBCPP_STD_VER >= 17
 79
 80// clang-format off
 81template <class _CharT, class _Traits, class _Allocator>
 82class _LIBCPP_PREFERRED_NAME(string)
 83#if _LIBCPP_HAS_WIDE_CHARACTERS
 84      _LIBCPP_PREFERRED_NAME(wstring)
 85#endif
 86#if _LIBCPP_HAS_CHAR8_T
 87      _LIBCPP_PREFERRED_NAME(u8string)
 88#endif
 89      _LIBCPP_PREFERRED_NAME(u16string)
 90      _LIBCPP_PREFERRED_NAME(u32string)
 91#if _LIBCPP_STD_VER >= 17
 92      _LIBCPP_PREFERRED_NAME(pmr::string)
 93#  if _LIBCPP_HAS_WIDE_CHARACTERS
 94      _LIBCPP_PREFERRED_NAME(pmr::wstring)
 95#  endif
 96#  if _LIBCPP_HAS_CHAR8_T
 97      _LIBCPP_PREFERRED_NAME(pmr::u8string)
 98#  endif
 99      _LIBCPP_PREFERRED_NAME(pmr::u16string)
100      _LIBCPP_PREFERRED_NAME(pmr::u32string)
101#endif
102      basic_string;
103// clang-format on
104
105_LIBCPP_END_NAMESPACE_STD
106
107#endif // _LIBCPP___FWD_STRING_H