xref: /freebsd-src/contrib/llvm-project/libcxx/include/__compare/compare_three_way.h (revision cb14a3fe5122c879eae1fb480ed7ce82a699ddb6)
1349cc55cSDimitry Andric // -*- C++ -*-
2349cc55cSDimitry Andric //===----------------------------------------------------------------------===//
3349cc55cSDimitry Andric //
4349cc55cSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5349cc55cSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
6349cc55cSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7349cc55cSDimitry Andric //
8349cc55cSDimitry Andric //===----------------------------------------------------------------------===//
9349cc55cSDimitry Andric 
10349cc55cSDimitry Andric #ifndef _LIBCPP___COMPARE_COMPARE_THREE_WAY_H
11349cc55cSDimitry Andric #define _LIBCPP___COMPARE_COMPARE_THREE_WAY_H
12349cc55cSDimitry Andric 
13349cc55cSDimitry Andric #include <__compare/three_way_comparable.h>
1404eeddc0SDimitry Andric #include <__config>
15349cc55cSDimitry Andric #include <__utility/forward.h>
16349cc55cSDimitry Andric 
17349cc55cSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
18349cc55cSDimitry Andric #  pragma GCC system_header
19349cc55cSDimitry Andric #endif
20349cc55cSDimitry Andric 
21349cc55cSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
22349cc55cSDimitry Andric 
2306c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20
24349cc55cSDimitry Andric 
25*cb14a3feSDimitry Andric struct _LIBCPP_TEMPLATE_VIS compare_three_way {
26349cc55cSDimitry Andric   template <class _T1, class _T2>
27349cc55cSDimitry Andric     requires three_way_comparable_with<_T1, _T2>
operatorcompare_three_way28*cb14a3feSDimitry Andric   constexpr _LIBCPP_HIDE_FROM_ABI auto operator()(_T1&& __t, _T2&& __u) const
29*cb14a3feSDimitry Andric       noexcept(noexcept(std::forward<_T1>(__t) <=> std::forward<_T2>(__u))) {
30*cb14a3feSDimitry Andric     return std::forward<_T1>(__t) <=> std::forward<_T2>(__u);
31*cb14a3feSDimitry Andric   }
32349cc55cSDimitry Andric 
33349cc55cSDimitry Andric   using is_transparent = void;
34349cc55cSDimitry Andric };
35349cc55cSDimitry Andric 
3606c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20
37349cc55cSDimitry Andric 
38349cc55cSDimitry Andric _LIBCPP_END_NAMESPACE_STD
39349cc55cSDimitry Andric 
40349cc55cSDimitry Andric #endif // _LIBCPP___COMPARE_COMPARE_THREE_WAY_H
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