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