xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/ranges_count.h (revision ee97f198b42d50437f87aa4111d478eca2a5be16)
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/ranges_count_if.h>
13  #include <__config>
14  #include <__functional/identity.h>
15  #include <__functional/ranges_operations.h>
16  #include <__iterator/concepts.h>
17  #include <__iterator/incrementable_traits.h>
18  #include <__iterator/iterator_traits.h>
19  #include <__iterator/projected.h>
20  #include <__ranges/access.h>
21  #include <__ranges/concepts.h>
22  #include <__utility/move.h>
23  
24  #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
25  #  pragma GCC system_header
26  #endif
27  
28  #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
29  
30  _LIBCPP_BEGIN_NAMESPACE_STD
31  
32  namespace ranges {
33  namespace __count {
34  struct __fn {
35    template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity>
36      requires indirect_binary_predicate<ranges::equal_to, projected<_Iter, _Proj>, const _Type*>
37    _LIBCPP_HIDE_FROM_ABI constexpr
38    iter_difference_t<_Iter> operator()(_Iter __first, _Sent __last, const _Type& __value, _Proj __proj = {}) const {
39      auto __pred = [&](auto&& __e) { return __e == __value; };
40      return ranges::__count_if_impl(std::move(__first), std::move(__last), __pred, __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_HIDE_FROM_ABI constexpr
46    range_difference_t<_Range> operator()(_Range&& __r, const _Type& __value, _Proj __proj = {}) const {
47      auto __pred = [&](auto&& __e) { return __e == __value; };
48      return ranges::__count_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
49    }
50  };
51  } // namespace __count
52  
53  inline namespace __cpo {
54    inline constexpr auto count = __count::__fn{};
55  } // namespace __cpo
56  } // namespace ranges
57  
58  _LIBCPP_END_NAMESPACE_STD
59  
60  #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
61  
62  #endif // _LIBCPP___ALGORITHM_RANGES_COUNT_H
63