libcxx/include/__functional/ranges_operations.h

   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___FUNCTIONAL_RANGES_OPERATIONS_H
  11 #define _LIBCPP___FUNCTIONAL_RANGES_OPERATIONS_H
  12
  13 #include <__concepts/equality_comparable.h>
  14 #include <__concepts/totally_ordered.h>
  15 #include <__config>
  16 #include <__type_traits/desugars_to.h>
  17 #include <__utility/forward.h>
  18
  19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  20 #  pragma GCC system_header
  21 #endif
  22
  23 _LIBCPP_BEGIN_NAMESPACE_STD
  24
  25 #if _LIBCPP_STD_VER >= 20
  26
  27 namespace ranges {
  28
  29 struct equal_to {
  30   template <class _Tp, class _Up>
  31     requires equality_comparable_with<_Tp, _Up>
  32   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_Tp&& __t, _Up&& __u) const
  33       noexcept(noexcept(bool(std::forward<_Tp>(__t) == std::forward<_Up>(__u)))) {
  34     return std::forward<_Tp>(__t) == std::forward<_Up>(__u);
  35   }
  36
  37   using is_transparent = void;
  38 };
  39
  40 struct not_equal_to {
  41   template <class _Tp, class _Up>
  42     requires equality_comparable_with<_Tp, _Up>
  43   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_Tp&& __t, _Up&& __u) const
  44       noexcept(noexcept(bool(!(std::forward<_Tp>(__t) == std::forward<_Up>(__u))))) {
  45     return !(std::forward<_Tp>(__t) == std::forward<_Up>(__u));
  46   }
  47
  48   using is_transparent = void;
  49 };
  50
  51 struct less {
  52   template <class _Tp, class _Up>
  53     requires totally_ordered_with<_Tp, _Up>
  54   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_Tp&& __t, _Up&& __u) const
  55       noexcept(noexcept(bool(std::forward<_Tp>(__t) < std::forward<_Up>(__u)))) {
  56     return std::forward<_Tp>(__t) < std::forward<_Up>(__u);
  57   }
  58
  59   using is_transparent = void;
  60 };
  61
  62 struct less_equal {
  63   template <class _Tp, class _Up>
  64     requires totally_ordered_with<_Tp, _Up>
  65   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_Tp&& __t, _Up&& __u) const
  66       noexcept(noexcept(bool(!(std::forward<_Up>(__u) < std::forward<_Tp>(__t))))) {
  67     return !(std::forward<_Up>(__u) < std::forward<_Tp>(__t));
  68   }
  69
  70   using is_transparent = void;
  71 };
  72
  73 struct greater {
  74   template <class _Tp, class _Up>
  75     requires totally_ordered_with<_Tp, _Up>
  76   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_Tp&& __t, _Up&& __u) const
  77       noexcept(noexcept(bool(std::forward<_Up>(__u) < std::forward<_Tp>(__t)))) {
  78     return std::forward<_Up>(__u) < std::forward<_Tp>(__t);
  79   }
  80
  81   using is_transparent = void;
  82 };
  83
  84 struct greater_equal {
  85   template <class _Tp, class _Up>
  86     requires totally_ordered_with<_Tp, _Up>
  87   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(_Tp&& __t, _Up&& __u) const
  88       noexcept(noexcept(bool(!(std::forward<_Tp>(__t) < std::forward<_Up>(__u))))) {
  89     return !(std::forward<_Tp>(__t) < std::forward<_Up>(__u));
  90   }
  91
  92   using is_transparent = void;
  93 };
  94
  95 } // namespace ranges
  96
  97 // For ranges we do not require that the types on each side of the equality
  98 // operator are of the same type
  99 template <class _Tp, class _Up>
 100 inline const bool __desugars_to_v<__equal_tag, ranges::equal_to, _Tp, _Up> = true;
 101
 102 template <class _Tp, class _Up>
 103 inline const bool __desugars_to_v<__totally_ordered_less_tag, ranges::less, _Tp, _Up> = true;
 104
 105 template <class _Tp, class _Up>
 106 inline const bool __desugars_to_v<__less_tag, ranges::less, _Tp, _Up> = true;
 107
 108 template <class _Tp, class _Up>
 109 inline const bool __desugars_to_v<__greater_tag, ranges::greater, _Tp, _Up> = true;
 110
 111 #endif // _LIBCPP_STD_VER >= 20
 112
 113 _LIBCPP_END_NAMESPACE_STD
 114
 115 #endif // _LIBCPP___FUNCTIONAL_RANGES_OPERATIONS_H