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_IF_H
10#define _LIBCPP___ALGORITHM_RANGES_COUNT_IF_H
11
12#include <__config>
13#include <__functional/identity.h>
14#include <__functional/invoke.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_LIBCPP_PUSH_MACROS
29#include <__undef_macros>
30
31#if _LIBCPP_STD_VER >= 20
32
33_LIBCPP_BEGIN_NAMESPACE_STD
34
35namespace ranges {
36template <class _Iter, class _Sent, class _Proj, class _Pred>
37_LIBCPP_HIDE_FROM_ABI constexpr iter_difference_t<_Iter>
38__count_if_impl(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
39  iter_difference_t<_Iter> __counter(0);
40  for (; __first != __last; ++__first) {
41    if (std::invoke(__pred, std::invoke(__proj, *__first)))
42      ++__counter;
43  }
44  return __counter;
45}
46
47namespace __count_if {
48struct __fn {
49  template <input_iterator _Iter,
50            sentinel_for<_Iter> _Sent,
51            class _Proj = identity,
52            indirect_unary_predicate<projected<_Iter, _Proj>> _Predicate>
53  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr iter_difference_t<_Iter>
54  operator()(_Iter __first, _Sent __last, _Predicate __pred, _Proj __proj = {}) const {
55    return ranges::__count_if_impl(std::move(__first), std::move(__last), __pred, __proj);
56  }
57
58  template <input_range _Range,
59            class _Proj = identity,
60            indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Predicate>
61  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr range_difference_t<_Range>
62  operator()(_Range&& __r, _Predicate __pred, _Proj __proj = {}) const {
63    return ranges::__count_if_impl(ranges::begin(__r), ranges::end(__r), __pred, __proj);
64  }
65};
66} // namespace __count_if
67
68inline namespace __cpo {
69inline constexpr auto count_if = __count_if::__fn{};
70} // namespace __cpo
71} // namespace ranges
72
73_LIBCPP_END_NAMESPACE_STD
74
75#endif // _LIBCPP_STD_VER >= 20
76
77_LIBCPP_POP_MACROS
78
79#endif // _LIBCPP___ALGORITHM_RANGES_COUNT_IF_H
80