libcxx/include/__cxx03/__algorithm/ranges_equal.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_RANGES_EQUAL_H
  10 #define _LIBCPP___ALGORITHM_RANGES_EQUAL_H
  11
  12 #include <__cxx03/__algorithm/equal.h>
  13 #include <__cxx03/__algorithm/unwrap_range.h>
  14 #include <__cxx03/__config>
  15 #include <__cxx03/__functional/identity.h>
  16 #include <__cxx03/__functional/invoke.h>
  17 #include <__cxx03/__functional/ranges_operations.h>
  18 #include <__cxx03/__iterator/concepts.h>
  19 #include <__cxx03/__iterator/distance.h>
  20 #include <__cxx03/__iterator/indirectly_comparable.h>
  21 #include <__cxx03/__ranges/access.h>
  22 #include <__cxx03/__ranges/concepts.h>
  23 #include <__cxx03/__utility/move.h>
  24
  25 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  26 #  pragma GCC system_header
  27 #endif
  28
  29 _LIBCPP_PUSH_MACROS
  30 #include <__cxx03/__undef_macros>
  31
  32 #if _LIBCPP_STD_VER >= 20
  33
  34 _LIBCPP_BEGIN_NAMESPACE_STD
  35
  36 namespace ranges {
  37 namespace __equal {
  38 struct __fn {
  39   template <input_iterator _Iter1,
  40             sentinel_for<_Iter1> _Sent1,
  41             input_iterator _Iter2,
  42             sentinel_for<_Iter2> _Sent2,
  43             class _Pred  = ranges::equal_to,
  44             class _Proj1 = identity,
  45             class _Proj2 = identity>
  46     requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2>
  47   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(
  48       _Iter1 __first1,
  49       _Sent1 __last1,
  50       _Iter2 __first2,
  51       _Sent2 __last2,
  52       _Pred __pred   = {},
  53       _Proj1 __proj1 = {},
  54       _Proj2 __proj2 = {}) const {
  55     if constexpr (sized_sentinel_for<_Sent1, _Iter1> && sized_sentinel_for<_Sent2, _Iter2>) {
  56       if (__last1 - __first1 != __last2 - __first2)
  57         return false;
  58     }
  59     auto __unwrapped1 = std::__unwrap_range(std::move(__first1), std::move(__last1));
  60     auto __unwrapped2 = std::__unwrap_range(std::move(__first2), std::move(__last2));
  61     return std::__equal_impl(
  62         std::move(__unwrapped1.first),
  63         std::move(__unwrapped1.second),
  64         std::move(__unwrapped2.first),
  65         std::move(__unwrapped2.second),
  66         __pred,
  67         __proj1,
  68         __proj2);
  69   }
  70
  71   template <input_range _Range1,
  72             input_range _Range2,
  73             class _Pred  = ranges::equal_to,
  74             class _Proj1 = identity,
  75             class _Proj2 = identity>
  76     requires indirectly_comparable<iterator_t<_Range1>, iterator_t<_Range2>, _Pred, _Proj1, _Proj2>
  77   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool operator()(
  78       _Range1&& __range1, _Range2&& __range2, _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) const {
  79     if constexpr (sized_range<_Range1> && sized_range<_Range2>) {
  80       if (ranges::distance(__range1) != ranges::distance(__range2))
  81         return false;
  82     }
  83     auto __unwrapped1 = std::__unwrap_range(ranges::begin(__range1), ranges::end(__range1));
  84     auto __unwrapped2 = std::__unwrap_range(ranges::begin(__range2), ranges::end(__range2));
  85     return std::__equal_impl(
  86         std::move(__unwrapped1.first),
  87         std::move(__unwrapped1.second),
  88         std::move(__unwrapped2.first),
  89         std::move(__unwrapped2.second),
  90         __pred,
  91         __proj1,
  92         __proj2);
  93     return false;
  94   }
  95 };
  96 } // namespace __equal
  97
  98 inline namespace __cpo {
  99 inline constexpr auto equal = __equal::__fn{};
 100 } // namespace __cpo
 101 } // namespace ranges
 102
 103 _LIBCPP_END_NAMESPACE_STD
 104
 105 #endif // _LIBCPP_STD_VER >= 20
 106
 107 _LIBCPP_POP_MACROS
 108
 109 #endif // _LIBCPP___ALGORITHM_RANGES_EQUAL_H