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_IS_PARTITIONED_H
10#define _LIBCPP___ALGORITHM_RANGES_IS_PARTITIONED_H
11
12#include <__config>
13#include <__functional/identity.h>
14#include <__functional/invoke.h>
15#include <__iterator/concepts.h>
16#include <__iterator/indirectly_comparable.h>
17#include <__iterator/projected.h>
18#include <__ranges/access.h>
19#include <__ranges/concepts.h>
20#include <__utility/move.h>
21
22#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
23# pragma GCC system_header
24#endif
25
26_LIBCPP_PUSH_MACROS
27#include <__undef_macros>
28
29#if _LIBCPP_STD_VER >= 20
30
31_LIBCPP_BEGIN_NAMESPACE_STD
32
33namespace ranges {
34struct __is_partitioned {
35 template <class _Iter, class _Sent, class _Proj, class _Pred>
36 constexpr static bool __is_partitioned_impl(_Iter __first, _Sent __last, _Pred& __pred, _Proj& __proj) {
37 for (; __first != __last; ++__first) {
38 if (!std::invoke(__pred, std::invoke(__proj, *__first)))
39 break;
40 }
41
42 if (__first == __last)
43 return true;
44 ++__first;
45
46 for (; __first != __last; ++__first) {
47 if (std::invoke(__pred, std::invoke(__proj, *__first)))
48 return false;
49 }
50
51 return true;
52 }
53
54 template <input_iterator _Iter,
55 sentinel_for<_Iter> _Sent,
56 class _Proj = identity,
57 indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
58 [[nodiscard]] constexpr bool operator()(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) const {
59 return __is_partitioned_impl(std::move(__first), std::move(__last), __pred, __proj);
60 }
61
62 template <input_range _Range,
63 class _Proj = identity,
64 indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
65 [[nodiscard]] constexpr bool operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
66 return __is_partitioned_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
67 }
68};
69
70inline namespace __cpo {
71inline constexpr auto is_partitioned = __is_partitioned{};
72} // namespace __cpo
73} // namespace ranges
74
75_LIBCPP_END_NAMESPACE_STD
76
77#endif // _LIBCPP_STD_VER >= 20
78
79_LIBCPP_POP_MACROS
80
81#endif // _LIBCPP___ALGORITHM_RANGES_IS_PARTITIONED_H
82