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_PARTITION_H
10 #define _LIBCPP___ALGORITHM_RANGES_PARTITION_H
11 
12 #include <__algorithm/iterator_operations.h>
13 #include <__algorithm/make_projected.h>
14 #include <__algorithm/partition.h>
15 #include <__algorithm/ranges_iterator_concept.h>
16 #include <__config>
17 #include <__functional/identity.h>
18 #include <__functional/invoke.h>
19 #include <__functional/ranges_operations.h>
20 #include <__iterator/concepts.h>
21 #include <__iterator/iterator_traits.h>
22 #include <__iterator/permutable.h>
23 #include <__iterator/projected.h>
24 #include <__ranges/access.h>
25 #include <__ranges/concepts.h>
26 #include <__ranges/subrange.h>
27 #include <__utility/forward.h>
28 #include <__utility/move.h>
29 #include <__utility/pair.h>
30 
31 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
32 #  pragma GCC system_header
33 #endif
34 
35 #if _LIBCPP_STD_VER >= 20
36 
37 _LIBCPP_BEGIN_NAMESPACE_STD
38 
39 namespace ranges {
40 namespace __partition {
41 
42 struct __fn {
43   template <class _Iter, class _Sent, class _Proj, class _Pred>
44   _LIBCPP_HIDE_FROM_ABI static constexpr subrange<__remove_cvref_t<_Iter>>
45   __partition_fn_impl(_Iter&& __first, _Sent&& __last, _Pred&& __pred, _Proj&& __proj) {
46     auto&& __projected_pred = std::__make_projected(__pred, __proj);
47     auto __result           = std::__partition<_RangeAlgPolicy>(
48         std::move(__first), std::move(__last), __projected_pred, __iterator_concept<_Iter>());
49 
50     return {std::move(__result.first), std::move(__result.second)};
51   }
52 
53   template <permutable _Iter,
54             sentinel_for<_Iter> _Sent,
55             class _Proj = identity,
56             indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
57   _LIBCPP_HIDE_FROM_ABI constexpr subrange<_Iter>
58   operator()(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) const {
59     return __partition_fn_impl(__first, __last, __pred, __proj);
60   }
61 
62   template <forward_range _Range,
63             class _Proj = identity,
64             indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
65     requires permutable<iterator_t<_Range>>
66   _LIBCPP_HIDE_FROM_ABI constexpr borrowed_subrange_t<_Range>
67   operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
68     return __partition_fn_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
69   }
70 };
71 
72 } // namespace __partition
73 
74 inline namespace __cpo {
75 inline constexpr auto partition = __partition::__fn{};
76 } // namespace __cpo
77 } // namespace ranges
78 
79 _LIBCPP_END_NAMESPACE_STD
80 
81 #endif // _LIBCPP_STD_VER >= 20
82 
83 #endif // _LIBCPP___ALGORITHM_RANGES_PARTITION_H
84