1*4bdff4beSrobert //===----------------------------------------------------------------------===// 2*4bdff4beSrobert // 3*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information. 5*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6*4bdff4beSrobert // 7*4bdff4beSrobert //===----------------------------------------------------------------------===// 8*4bdff4beSrobert 9*4bdff4beSrobert #ifndef _LIBCPP___COMPARE_SYNTH_THREE_WAY_H 10*4bdff4beSrobert #define _LIBCPP___COMPARE_SYNTH_THREE_WAY_H 11*4bdff4beSrobert 12*4bdff4beSrobert #include <__compare/ordering.h> 13*4bdff4beSrobert #include <__compare/three_way_comparable.h> 14*4bdff4beSrobert #include <__concepts/boolean_testable.h> 15*4bdff4beSrobert #include <__config> 16*4bdff4beSrobert #include <__utility/declval.h> 17*4bdff4beSrobert 18*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 19*4bdff4beSrobert # pragma GCC system_header 20*4bdff4beSrobert #endif 21*4bdff4beSrobert 22*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD 23*4bdff4beSrobert 24*4bdff4beSrobert #if _LIBCPP_STD_VER > 17 25*4bdff4beSrobert 26*4bdff4beSrobert // [expos.only.func] 27*4bdff4beSrobert 28*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI inline constexpr auto __synth_three_way = 29*4bdff4beSrobert []<class _Tp, class _Up>(const _Tp& __t, const _Up& __u) 30*4bdff4beSrobert requires requires { 31*4bdff4beSrobert { __t < __u } -> __boolean_testable; 32*4bdff4beSrobert { __u < __t } -> __boolean_testable; 33*4bdff4beSrobert } 34*4bdff4beSrobert { 35*4bdff4beSrobert if constexpr (three_way_comparable_with<_Tp, _Up>) { 36*4bdff4beSrobert return __t <=> __u; 37*4bdff4beSrobert } else { 38*4bdff4beSrobert if (__t < __u) return weak_ordering::less; 39*4bdff4beSrobert if (__u < __t) return weak_ordering::greater; 40*4bdff4beSrobert return weak_ordering::equivalent; 41*4bdff4beSrobert } 42*4bdff4beSrobert }; 43*4bdff4beSrobert 44*4bdff4beSrobert template <class _Tp, class _Up = _Tp> 45*4bdff4beSrobert using __synth_three_way_result = decltype(std::__synth_three_way(std::declval<_Tp&>(), std::declval<_Up&>())); 46*4bdff4beSrobert 47*4bdff4beSrobert #endif // _LIBCPP_STD_VER > 17 48*4bdff4beSrobert 49*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD 50*4bdff4beSrobert 51*4bdff4beSrobert #endif // _LIBCPP___COMPARE_SYNTH_THREE_WAY_H 52