libcxx/include/__cxx03/__algorithm/comp.h

   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 <__cxx03/__config>
  13 #include <__cxx03/__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