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 _LIBCPP_PUSH_MACROS
36 #include <__undef_macros>
37 
38 #if _LIBCPP_STD_VER >= 20
39 
40 _LIBCPP_BEGIN_NAMESPACE_STD
41 
42 namespace ranges {
43 namespace __partition {
44 
45 struct __fn {
46   template <class _Iter, class _Sent, class _Proj, class _Pred>
47   _LIBCPP_HIDE_FROM_ABI static constexpr subrange<__remove_cvref_t<_Iter>>
48   __partition_fn_impl(_Iter&& __first, _Sent&& __last, _Pred&& __pred, _Proj&& __proj) {
49     auto&& __projected_pred = std::__make_projected(__pred, __proj);
50     auto __result           = std::__partition<_RangeAlgPolicy>(
51         std::move(__first), std::move(__last), __projected_pred, __iterator_concept<_Iter>());
52 
53     return {std::move(__result.first), std::move(__result.second)};
54   }
55 
56   template <permutable _Iter,
57             sentinel_for<_Iter> _Sent,
58             class _Proj = identity,
59             indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
60   _LIBCPP_HIDE_FROM_ABI constexpr subrange<_Iter>
61   operator()(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) const {
62     return __partition_fn_impl(__first, __last, __pred, __proj);
63   }
64 
65   template <forward_range _Range,
66             class _Proj = identity,
67             indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
68     requires permutable<iterator_t<_Range>>
69   _LIBCPP_HIDE_FROM_ABI constexpr borrowed_subrange_t<_Range>
70   operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
71     return __partition_fn_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
72   }
73 };
74 
75 } // namespace __partition
76 
77 inline namespace __cpo {
78 inline constexpr auto partition = __partition::__fn{};
79 } // namespace __cpo
80 } // namespace ranges
81 
82 _LIBCPP_END_NAMESPACE_STD
83 
84 #endif // _LIBCPP_STD_VER >= 20
85 
86 _LIBCPP_POP_MACROS
87 
88 #endif // _LIBCPP___ALGORITHM_RANGES_PARTITION_H
89