xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/ranges_count.h (revision a2fda816eb054d5873be223ef2461741dfcc253c)
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  namespace __count {
38  struct __fn {
39    template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity>
40      requires indirect_binary_predicate<ranges::equal_to, projected<_Iter, _Proj>, const _Type*>
41    _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr iter_difference_t<_Iter>
42    operator()(_Iter __first, _Sent __last, const _Type& __value, _Proj __proj = {}) const {
43      return std::__count<_RangeAlgPolicy>(std::move(__first), std::move(__last), __value, __proj);
44    }
45  
46    template <input_range _Range, class _Type, class _Proj = identity>
47      requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<_Range>, _Proj>, const _Type*>
48    _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr range_difference_t<_Range>
49    operator()(_Range&& __r, const _Type& __value, _Proj __proj = {}) const {
50      return std::__count<_RangeAlgPolicy>(ranges::begin(__r), ranges::end(__r), __value, __proj);
51    }
52  };
53  } // namespace __count
54  
55  inline namespace __cpo {
56  inline constexpr auto count = __count::__fn{};
57  } // namespace __cpo
58  } // namespace ranges
59  
60  _LIBCPP_END_NAMESPACE_STD
61  
62  #endif // _LIBCPP_STD_VER >= 20
63  
64  _LIBCPP_POP_MACROS
65  
66  #endif // _LIBCPP___ALGORITHM_RANGES_COUNT_H
67