xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/comp.h (revision b64c5a0ace59af62eff52bfe110a521dc73c937b)
1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___ALGORITHM_COMP_H
10 #define _LIBCPP___ALGORITHM_COMP_H
11 
12 #include <__config>
13 #include <__type_traits/desugars_to.h>
14 
15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16 #  pragma GCC system_header
17 #endif
18 
19 _LIBCPP_BEGIN_NAMESPACE_STD
20 
21 struct __equal_to {
22   template <class _T1, class _T2>
23   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(const _T1& __x, const _T2& __y) const {
24     return __x == __y;
25   }
26 };
27 
28 template <class _Tp, class _Up>
29 inline const bool __desugars_to_v<__equal_tag, __equal_to, _Tp, _Up> = true;
30 
31 // The definition is required because __less is part of the ABI, but it's empty
32 // because all comparisons should be transparent.
33 template <class _T1 = void, class _T2 = _T1>
34 struct __less {};
35 
36 template <>
37 struct __less<void, void> {
38   template <class _Tp, class _Up>
39   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 bool operator()(const _Tp& __lhs, const _Up& __rhs) const {
40     return __lhs < __rhs;
41   }
42 };
43 
44 template <class _Tp>
45 inline const bool __desugars_to_v<__less_tag, __less<>, _Tp, _Tp> = true;
46 
47 _LIBCPP_END_NAMESPACE_STD
48 
49 #endif // _LIBCPP___ALGORITHM_COMP_H
50