libcxx/include/__algorithm/ranges_count.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_COUNT_H
  10 #define _LIBCPP___ALGORITHM_RANGES_COUNT_H
  11
  12 #include <__algorithm/count.h>
  13 #include <__algorithm/iterator_operations.h>
  14 #include <__config>
  15 #include <__functional/identity.h>
  16 #include <__functional/ranges_operations.h>
  17 #include <__iterator/concepts.h>
  18 #include <__iterator/incrementable_traits.h>
  19 #include <__iterator/iterator_traits.h>
  20 #include <__iterator/projected.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 _LIBCPP_PUSH_MACROS
  30 #include <__undef_macros>
  31
  32 #if _LIBCPP_STD_VER >= 20
  33
  34 _LIBCPP_BEGIN_NAMESPACE_STD
  35
  36 namespace ranges {
  37 struct __count {
  38   template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity>
  39     requires indirect_binary_predicate<ranges::equal_to, projected<_Iter, _Proj>, const _Type*>
  40   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr iter_difference_t<_Iter>
  41   operator()(_Iter __first, _Sent __last, const _Type& __value, _Proj __proj = {}) const {
  42     return std::__count<_RangeAlgPolicy>(std::move(__first), std::move(__last), __value, __proj);
  43   }
  44
  45   template <input_range _Range, class _Type, class _Proj = identity>
  46     requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<_Range>, _Proj>, const _Type*>
  47   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr range_difference_t<_Range>
  48   operator()(_Range&& __r, const _Type& __value, _Proj __proj = {}) const {
  49     return std::__count<_RangeAlgPolicy>(ranges::begin(__r), ranges::end(__r), __value, __proj);
  50   }
  51 };
  52
  53 inline namespace __cpo {
  54 inline constexpr auto count = __count{};
  55 } // namespace __cpo
  56 } // namespace ranges
  57
  58 _LIBCPP_END_NAMESPACE_STD
  59
  60 #endif // _LIBCPP_STD_VER >= 20
  61
  62 _LIBCPP_POP_MACROS
  63
  64 #endif // _LIBCPP___ALGORITHM_RANGES_COUNT_H