// Concept-constrained comparison implementations -*- C++ -*- // Copyright (C) 2019-2020 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/range_cmp.h * This is an internal header file, included by other library headers. * Do not attempt to use it directly. @headername{functional} */ #ifndef _RANGE_CMP_H #define _RANGE_CMP_H 1 #if __cplusplus > 201703L # include <bits/move.h> # include <concepts> namespace std _GLIBCXX_VISIBILITY(default) { _GLIBCXX_BEGIN_NAMESPACE_VERSION struct __is_transparent; // not defined // Define std::identity here so that <iterator> and <ranges> // don't need to include <bits/stl_function.h> to get it. /// [func.identity] The identity function. struct identity { template<typename _Tp> constexpr _Tp&& operator()(_Tp&& __t) const noexcept { return std::forward<_Tp>(__t); } using is_transparent = __is_transparent; }; #ifdef __cpp_lib_concepts // Define this here, included by all the headers that need to define it. #define __cpp_lib_ranges 201911L namespace ranges { namespace __detail { // BUILTIN-PTR-CMP(T, ==, U) template<typename _Tp, typename _Up> concept __eq_builtin_ptr_cmp = requires (_Tp&& __t, _Up&& __u) { { __t == __u } -> same_as<bool>; } && convertible_to<_Tp, const volatile void*> && convertible_to<_Up, const volatile void*> && (! requires(_Tp&& __t, _Up&& __u) { operator==(std::forward<_Tp>(__t), std::forward<_Up>(__u)); } && ! requires(_Tp&& __t, _Up&& __u) { std::forward<_Tp>(__t).operator==(std::forward<_Up>(__u)); }); // BUILTIN-PTR-CMP(T, <, U) template<typename _Tp, typename _Up> concept __less_builtin_ptr_cmp = requires (_Tp&& __t, _Up&& __u) { { __t < __u } -> same_as<bool>; } && convertible_to<_Tp, const volatile void*> && convertible_to<_Up, const volatile void*> && (! requires(_Tp&& __t, _Up&& __u) { operator<(std::forward<_Tp>(__t), std::forward<_Up>(__u)); } && ! requires(_Tp&& __t, _Up&& __u) { std::forward<_Tp>(__t).operator<(std::forward<_Up>(__u)); }); } // namespace __detail // [range.cmp] Concept-constrained comparisons /// ranges::equal_to function object type. struct equal_to { template<typename _Tp, typename _Up> requires equality_comparable_with<_Tp, _Up> || __detail::__eq_builtin_ptr_cmp<_Tp, _Up> constexpr bool operator()(_Tp&& __t, _Up&& __u) const noexcept(noexcept(std::declval<_Tp>() == std::declval<_Up>())) { return std::forward<_Tp>(__t) == std::forward<_Up>(__u); } using is_transparent = __is_transparent; }; /// ranges::not_equal_to function object type. struct not_equal_to { template<typename _Tp, typename _Up> requires equality_comparable_with<_Tp, _Up> || __detail::__eq_builtin_ptr_cmp<_Tp, _Up> constexpr bool operator()(_Tp&& __t, _Up&& __u) const noexcept(noexcept(std::declval<_Up>() == std::declval<_Tp>())) { return !equal_to{}(std::forward<_Tp>(__t), std::forward<_Up>(__u)); } using is_transparent = __is_transparent; }; /// ranges::less function object type. struct less { template<typename _Tp, typename _Up> requires totally_ordered_with<_Tp, _Up> || __detail::__less_builtin_ptr_cmp<_Tp, _Up> constexpr bool operator()(_Tp&& __t, _Up&& __u) const noexcept(noexcept(std::declval<_Tp>() < std::declval<_Up>())) { if constexpr (__detail::__less_builtin_ptr_cmp<_Tp, _Up>) { #ifdef __cpp_lib_is_constant_evaluated if (std::is_constant_evaluated()) return __t < __u; #endif auto __x = reinterpret_cast<__UINTPTR_TYPE__>( static_cast<const volatile void*>(std::forward<_Tp>(__t))); auto __y = reinterpret_cast<__UINTPTR_TYPE__>( static_cast<const volatile void*>(std::forward<_Up>(__u))); return __x < __y; } else return std::forward<_Tp>(__t) < std::forward<_Up>(__u); } using is_transparent = __is_transparent; }; /// ranges::greater function object type. struct greater { template<typename _Tp, typename _Up> requires totally_ordered_with<_Tp, _Up> || __detail::__less_builtin_ptr_cmp<_Up, _Tp> constexpr bool operator()(_Tp&& __t, _Up&& __u) const noexcept(noexcept(std::declval<_Up>() < std::declval<_Tp>())) { return less{}(std::forward<_Up>(__u), std::forward<_Tp>(__t)); } using is_transparent = __is_transparent; }; /// ranges::greater_equal function object type. struct greater_equal { template<typename _Tp, typename _Up> requires totally_ordered_with<_Tp, _Up> || __detail::__less_builtin_ptr_cmp<_Tp, _Up> constexpr bool operator()(_Tp&& __t, _Up&& __u) const noexcept(noexcept(std::declval<_Tp>() < std::declval<_Up>())) { return !less{}(std::forward<_Tp>(__t), std::forward<_Up>(__u)); } using is_transparent = __is_transparent; }; /// ranges::less_equal function object type. struct less_equal { template<typename _Tp, typename _Up> requires totally_ordered_with<_Tp, _Up> || __detail::__less_builtin_ptr_cmp<_Up, _Tp> constexpr bool operator()(_Tp&& __t, _Up&& __u) const noexcept(noexcept(std::declval<_Up>() < std::declval<_Tp>())) { return !less{}(std::forward<_Up>(__u), std::forward<_Tp>(__t)); } using is_transparent = __is_transparent; }; } // namespace ranges #endif // library concepts _GLIBCXX_END_NAMESPACE_VERSION } // namespace std #endif // C++20 #endif // _RANGE_CMP_H