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
25struct 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