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  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_UNIQUE_COPY_H
 10#define _LIBCPP___ALGORITHM_RANGES_UNIQUE_COPY_H
 11
 12#include <__algorithm/in_out_result.h>
 13#include <__algorithm/iterator_operations.h>
 14#include <__algorithm/make_projected.h>
 15#include <__algorithm/unique_copy.h>
 16#include <__concepts/same_as.h>
 17#include <__config>
 18#include <__functional/identity.h>
 19#include <__functional/invoke.h>
 20#include <__functional/ranges_operations.h>
 21#include <__iterator/concepts.h>
 22#include <__iterator/iterator_traits.h>
 23#include <__iterator/projected.h>
 24#include <__ranges/access.h>
 25#include <__ranges/concepts.h>
 26#include <__ranges/dangling.h>
 27#include <__utility/forward.h>
 28#include <__utility/move.h>
 29#include <__utility/pair.h>
 30
 31#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 32#  pragma GCC system_header
 33#endif
 34
 35_LIBCPP_PUSH_MACROS
 36#include <__undef_macros>
 37
 38#if _LIBCPP_STD_VER >= 20
 39
 40_LIBCPP_BEGIN_NAMESPACE_STD
 41
 42namespace ranges {
 43
 44template <class _InIter, class _OutIter>
 45using unique_copy_result = in_out_result<_InIter, _OutIter>;
 46
 47template <class _InIter, class _OutIter>
 48concept __can_reread_from_output = (input_iterator<_OutIter> && same_as<iter_value_t<_InIter>, iter_value_t<_OutIter>>);
 49
 50struct __unique_copy {
 51  template <class _InIter, class _OutIter>
 52  static consteval auto __get_algo_tag() {
 53    if constexpr (forward_iterator<_InIter>) {
 54      return __unique_copy_tags::__reread_from_input_tag{};
 55    } else if constexpr (__can_reread_from_output<_InIter, _OutIter>) {
 56      return __unique_copy_tags::__reread_from_output_tag{};
 57    } else if constexpr (indirectly_copyable_storable<_InIter, _OutIter>) {
 58      return __unique_copy_tags::__read_from_tmp_value_tag{};
 59    }
 60  }
 61
 62  template <class _InIter, class _OutIter>
 63  using __algo_tag_t _LIBCPP_NODEBUG = decltype(__get_algo_tag<_InIter, _OutIter>());
 64
 65  template <input_iterator _InIter,
 66            sentinel_for<_InIter> _Sent,
 67            weakly_incrementable _OutIter,
 68            class _Proj                                                    = identity,
 69            indirect_equivalence_relation<projected<_InIter, _Proj>> _Comp = ranges::equal_to>
 70    requires indirectly_copyable<_InIter, _OutIter> &&
 71             (forward_iterator<_InIter> ||
 72              (input_iterator<_OutIter> && same_as<iter_value_t<_InIter>, iter_value_t<_OutIter>>) ||
 73              indirectly_copyable_storable<_InIter, _OutIter>)
 74  _LIBCPP_HIDE_FROM_ABI constexpr unique_copy_result<_InIter, _OutIter>
 75  operator()(_InIter __first, _Sent __last, _OutIter __result, _Comp __comp = {}, _Proj __proj = {}) const {
 76    auto __ret = std::__unique_copy<_RangeAlgPolicy>(
 77        std::move(__first),
 78        std::move(__last),
 79        std::move(__result),
 80        std::__make_projected(__comp, __proj),
 81        __algo_tag_t<_InIter, _OutIter>());
 82    return {std::move(__ret.first), std::move(__ret.second)};
 83  }
 84
 85  template <input_range _Range,
 86            weakly_incrementable _OutIter,
 87            class _Proj                                                               = identity,
 88            indirect_equivalence_relation<projected<iterator_t<_Range>, _Proj>> _Comp = ranges::equal_to>
 89    requires indirectly_copyable<iterator_t<_Range>, _OutIter> &&
 90             (forward_iterator<iterator_t<_Range>> ||
 91              (input_iterator<_OutIter> && same_as<range_value_t<_Range>, iter_value_t<_OutIter>>) ||
 92              indirectly_copyable_storable<iterator_t<_Range>, _OutIter>)
 93  _LIBCPP_HIDE_FROM_ABI constexpr unique_copy_result<borrowed_iterator_t<_Range>, _OutIter>
 94  operator()(_Range&& __range, _OutIter __result, _Comp __comp = {}, _Proj __proj = {}) const {
 95    auto __ret = std::__unique_copy<_RangeAlgPolicy>(
 96        ranges::begin(__range),
 97        ranges::end(__range),
 98        std::move(__result),
 99        std::__make_projected(__comp, __proj),
100        __algo_tag_t<iterator_t<_Range>, _OutIter>());
101    return {std::move(__ret.first), std::move(__ret.second)};
102  }
103};
104
105inline namespace __cpo {
106inline constexpr auto unique_copy = __unique_copy{};
107} // namespace __cpo
108} // namespace ranges
109
110_LIBCPP_END_NAMESPACE_STD
111
112#endif // _LIBCPP_STD_VER >= 20
113
114_LIBCPP_POP_MACROS
115
116#endif // _LIBCPP___ALGORITHM_RANGES_UNIQUE_COPY_H