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/projected.h>
19 #include <__ranges/access.h>
20 #include <__ranges/concepts.h>
21 #include <__utility/move.h>
22 
23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24 #  pragma GCC system_header
25 #endif
26 
27 #if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
28 
29 _LIBCPP_BEGIN_NAMESPACE_STD
30 
31 namespace ranges {
32 namespace __count {
33 struct __fn {
34   template <input_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity>
35     requires indirect_binary_predicate<ranges::equal_to, projected<_Iter, _Proj>, const _Type*>
36   _LIBCPP_HIDE_FROM_ABI constexpr
37   iter_difference_t<_Iter> operator()(_Iter __first, _Sent __last, const _Type& __value, _Proj __proj = {}) const {
38     auto __pred = [&](auto&& __e) { return __e == __value; };
39     return ranges::__count_if_impl(std::move(__first), std::move(__last), __pred, __proj);
40   }
41 
42   template <input_range _Range, class _Type, class _Proj = identity>
43     requires indirect_binary_predicate<ranges::equal_to, projected<iterator_t<_Range>, _Proj>, const _Type*>
44   _LIBCPP_HIDE_FROM_ABI constexpr
45   range_difference_t<_Range> operator()(_Range&& __r, const _Type& __value, _Proj __proj = {}) const {
46     auto __pred = [&](auto&& __e) { return __e == __value; };
47     return ranges::__count_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __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 > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
60 
61 #endif // _LIBCPP___ALGORITHM_RANGES_COUNT_H
62