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#if _LIBCPP_STD_VER > 17
27
28_LIBCPP_BEGIN_NAMESPACE_STD
29
30namespace ranges {
31namespace __is_partitioned {
32struct __fn {
33
34  template <class _Iter, class _Sent, class _Proj, class _Pred>
35  _LIBCPP_HIDE_FROM_ABI constexpr static
36  bool __is_parititioned_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, sentinel_for<_Iter> _Sent,
55            class _Proj = identity,
56            indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
57  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr
58  bool operator()(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) const {
59    return __is_parititioned_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  _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr
66  bool operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
67    return __is_parititioned_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
68  }
69};
70} // namespace __is_partitioned
71
72inline namespace __cpo {
73  inline constexpr auto is_partitioned = __is_partitioned::__fn{};
74} // namespace __cpo
75} // namespace ranges
76
77_LIBCPP_END_NAMESPACE_STD
78
79#endif // _LIBCPP_STD_VER > 17
80
81#endif // _LIBCPP___ALGORITHM_RANGES_IS_PARTITIONED_H
82