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 #if _LIBCPP_STD_VER >= 20
  30
  31 _LIBCPP_BEGIN_NAMESPACE_STD
  32
  33 namespace ranges {
  34 namespace __count {
  35 struct __fn {
  36   template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity>
  37     requires indirect_binary_predicate<ranges::equal_to, projected<_Iter, _Proj>, const _Type*>
  38   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr iter_difference_t<_Iter>
  39   operator()(_Iter __first, _Sent __last, const _Type& __value, _Proj __proj = {}) const {
  40     return std::__count<_RangeAlgPolicy>(std::move(__first), std::move(__last), __value, __proj);
  41   }
  42
  43   template <input_range _Range, class _Type, class _Proj = identity>
  44     requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<_Range>, _Proj>, const _Type*>
  45   _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr range_difference_t<_Range>
  46   operator()(_Range&& __r, const _Type& __value, _Proj __proj = {}) const {
  47     return std::__count<_RangeAlgPolicy>(ranges::begin(__r), ranges::end(__r), __value, __proj);
  48   }
  49 };
  50 } // namespace __count
  51
  52 inline namespace __cpo {
  53 inline constexpr auto count = __count::__fn{};
  54 } // namespace __cpo
  55 } // namespace ranges
  56
  57 _LIBCPP_END_NAMESPACE_STD
  58
  59 #endif // _LIBCPP_STD_VER >= 20
  60
  61 #endif // _LIBCPP___ALGORITHM_RANGES_COUNT_H