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The C and C++ Include Header Files
cat -n /usr/include/c++/15/bits/ranges_cmp.h
1 // Concept-constrained comparison implementations -*- C++ -*- 2 3 // Copyright (C) 2019-2025 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the 7 // terms of the GNU General Public License as published by the 8 // Free Software Foundation; either version 3, or (at your option) 9 // any later version. 10 11 // This library is distributed in the hope that it will be useful, 12 // but WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 // GNU General Public License for more details. 15 16 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 /** @file bits/ranges_cmp.h 26 * This is an internal header file, included by other library headers. 27 * Do not attempt to use it directly. @headername{functional} 28 */ 29 30 #ifndef _RANGES_CMP_H 31 #define _RANGES_CMP_H 1 32 33 #if __cplusplus > 201703L 34 # include <bits/move.h> 35 # include <concepts> 36 37 namespace std _GLIBCXX_VISIBILITY(default) 38 { 39 _GLIBCXX_BEGIN_NAMESPACE_VERSION 40 41 struct __is_transparent; // not defined 42 43 // Define std::identity here so that <iterator> and <ranges> 44 // don't need to include <bits/stl_function.h> to get it. 45 46 /// [func.identity] The identity function. 47 struct identity 48 { 49 template<typename _Tp> 50 [[nodiscard]] 51 constexpr _Tp&& 52 operator()(_Tp&& __t) const noexcept 53 { return std::forward<_Tp>(__t); } 54 55 using is_transparent = __is_transparent; 56 }; 57 58 #ifdef __glibcxx_ranges // C++ >= 20 59 namespace ranges 60 { 61 namespace __detail 62 { 63 // BUILTIN-PTR-CMP(T, <, U) 64 // This determines whether t < u results in a call to a built-in operator< 65 // comparing pointers. It doesn't work for function pointers (PR 93628). 66 template<typename _Tp, typename _Up> 67 concept __less_builtin_ptr_cmp 68 = requires (_Tp&& __t, _Up&& __u) { { __t < __u } -> same_as<bool>; } 69 && convertible_to<_Tp, const volatile void*> 70 && convertible_to<_Up, const volatile void*> 71 && ! requires(_Tp&& __t, _Up&& __u) 72 { operator<(std::forward<_Tp>(__t), std::forward<_Up>(__u)); } 73 && ! requires(_Tp&& __t, _Up&& __u) 74 { std::forward<_Tp>(__t).operator<(std::forward<_Up>(__u)); } 75 && std::__detail::__not_overloaded_spaceship<_Tp, _Up>; 76 } // namespace __detail 77 78 // [range.cmp] Concept-constrained comparisons 79 80 // _GLIBCXX_RESOLVE_LIB_DEFECTS 81 // 3530 BUILTIN-PTR-MEOW should not opt the type out of syntactic checks 82 83 /// ranges::equal_to function object type. 84 struct equal_to 85 { 86 template<typename _Tp, typename _Up> 87 requires equality_comparable_with<_Tp, _Up> 88 constexpr bool 89 operator()(_Tp&& __t, _Up&& __u) const 90 noexcept(noexcept(std::declval<_Tp>() == std::declval<_Up>())) 91 { return std::forward<_Tp>(__t) == std::forward<_Up>(__u); } 92 93 using is_transparent = __is_transparent; 94 }; 95 96 /// ranges::not_equal_to function object type. 97 struct not_equal_to 98 { 99 template<typename _Tp, typename _Up> 100 requires equality_comparable_with<_Tp, _Up> 101 constexpr bool 102 operator()(_Tp&& __t, _Up&& __u) const 103 noexcept(noexcept(std::declval<_Tp>() == std::declval<_Up>())) 104 { return !equal_to{}(std::forward<_Tp>(__t), std::forward<_Up>(__u)); } 105 106 using is_transparent = __is_transparent; 107 }; 108 109 /// ranges::less function object type. 110 struct less 111 { 112 template<typename _Tp, typename _Up> 113 requires totally_ordered_with<_Tp, _Up> 114 constexpr bool 115 operator()(_Tp&& __t, _Up&& __u) const 116 noexcept(noexcept(std::declval<_Tp>() < std::declval<_Up>())) 117 { 118 if constexpr (__detail::__less_builtin_ptr_cmp<_Tp, _Up>) 119 { 120 if (std::__is_constant_evaluated()) 121 return __t < __u; 122 123 auto __x = reinterpret_cast<__UINTPTR_TYPE__>( 124 static_cast<const volatile void*>(std::forward<_Tp>(__t))); 125 auto __y = reinterpret_cast<__UINTPTR_TYPE__>( 126 static_cast<const volatile void*>(std::forward<_Up>(__u))); 127 return __x < __y; 128 } 129 else 130 return std::forward<_Tp>(__t) < std::forward<_Up>(__u); 131 } 132 133 using is_transparent = __is_transparent; 134 }; 135 136 /// ranges::greater function object type. 137 struct greater 138 { 139 template<typename _Tp, typename _Up> 140 requires totally_ordered_with<_Tp, _Up> 141 constexpr bool 142 operator()(_Tp&& __t, _Up&& __u) const 143 noexcept(noexcept(std::declval<_Up>() < std::declval<_Tp>())) 144 { return less{}(std::forward<_Up>(__u), std::forward<_Tp>(__t)); } 145 146 using is_transparent = __is_transparent; 147 }; 148 149 /// ranges::greater_equal function object type. 150 struct greater_equal 151 { 152 template<typename _Tp, typename _Up> 153 requires totally_ordered_with<_Tp, _Up> 154 constexpr bool 155 operator()(_Tp&& __t, _Up&& __u) const 156 noexcept(noexcept(std::declval<_Tp>() < std::declval<_Up>())) 157 { return !less{}(std::forward<_Tp>(__t), std::forward<_Up>(__u)); } 158 159 using is_transparent = __is_transparent; 160 }; 161 162 /// ranges::less_equal function object type. 163 struct less_equal 164 { 165 template<typename _Tp, typename _Up> 166 requires totally_ordered_with<_Tp, _Up> 167 constexpr bool 168 operator()(_Tp&& __t, _Up&& __u) const 169 noexcept(noexcept(std::declval<_Up>() < std::declval<_Tp>())) 170 { return !less{}(std::forward<_Up>(__u), std::forward<_Tp>(__t)); } 171 172 using is_transparent = __is_transparent; 173 }; 174 175 } // namespace ranges 176 #endif // __glibcxx_ranges 177 _GLIBCXX_END_NAMESPACE_VERSION 178 } // namespace std 179 #endif // C++20 180 #endif // _RANGES_CMP_H
