1 // -*- C++ -*- 2 //===----------------------------------------------------------------------===// 3 // 4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 5 // See https://llvm.org/LICENSE.txt for license information. 6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 7 // 8 //===----------------------------------------------------------------------===// 9 10 #ifndef _LIBCPP___COMPARE_COMPARE_THREE_WAY_H 11 #define _LIBCPP___COMPARE_COMPARE_THREE_WAY_H 12 13 #include <__compare/three_way_comparable.h> 14 #include <__config> 15 #include <__utility/forward.h> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 # pragma GCC system_header 19 #endif 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 #if _LIBCPP_STD_VER >= 20 24 25 struct _LIBCPP_TEMPLATE_VIS compare_three_way { 26 template <class _T1, class _T2> 27 requires three_way_comparable_with<_T1, _T2> 28 constexpr _LIBCPP_HIDE_FROM_ABI auto operator()(_T1&& __t, _T2&& __u) const 29 noexcept(noexcept(std::forward<_T1>(__t) <=> std::forward<_T2>(__u))) { 30 return std::forward<_T1>(__t) <=> std::forward<_T2>(__u); 31 } 32 33 using is_transparent = void; 34 }; 35 36 #endif // _LIBCPP_STD_VER >= 20 37 38 _LIBCPP_END_NAMESPACE_STD 39 40 #endif // _LIBCPP___COMPARE_COMPARE_THREE_WAY_H 41