xref: /llvm-project/libcxx/include/__algorithm/ranges_stable_partition.h (revision d10dc5a06fac4dcabf2264c64c8672c6f6ae36fb)
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_STABLE_PARTITION_H
10 #define _LIBCPP___ALGORITHM_RANGES_STABLE_PARTITION_H
11 
12 #include <__algorithm/iterator_operations.h>
13 #include <__algorithm/make_projected.h>
14 #include <__algorithm/ranges_iterator_concept.h>
15 #include <__algorithm/stable_partition.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/next.h>
23 #include <__iterator/permutable.h>
24 #include <__iterator/projected.h>
25 #include <__ranges/access.h>
26 #include <__ranges/concepts.h>
27 #include <__ranges/dangling.h>
28 #include <__ranges/subrange.h>
29 #include <__type_traits/remove_cvref.h>
30 #include <__utility/forward.h>
31 #include <__utility/move.h>
32 
33 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
34 #  pragma GCC system_header
35 #endif
36 
37 _LIBCPP_PUSH_MACROS
38 #include <__undef_macros>
39 
40 #if _LIBCPP_STD_VER >= 20
41 
42 _LIBCPP_BEGIN_NAMESPACE_STD
43 
44 namespace ranges {
45 struct __stable_partition {
46   template <class _Iter, class _Sent, class _Proj, class _Pred>
47   _LIBCPP_HIDE_FROM_ABI static subrange<__remove_cvref_t<_Iter>>
48   __stable_partition_fn_impl(_Iter&& __first, _Sent&& __last, _Pred&& __pred, _Proj&& __proj) {
49     auto __last_iter = ranges::next(__first, __last);
50 
51     auto&& __projected_pred = std::__make_projected(__pred, __proj);
52     auto __result           = std::__stable_partition<_RangeAlgPolicy>(
53         std::move(__first), __last_iter, __projected_pred, __iterator_concept<_Iter>());
54 
55     return {std::move(__result), std::move(__last_iter)};
56   }
57 
58   template <bidirectional_iterator _Iter,
59             sentinel_for<_Iter> _Sent,
60             class _Proj = identity,
61             indirect_unary_predicate<projected<_Iter, _Proj>> _Pred>
62     requires permutable<_Iter>
63   _LIBCPP_HIDE_FROM_ABI subrange<_Iter> operator()(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) const {
64     return __stable_partition_fn_impl(__first, __last, __pred, __proj);
65   }
66 
67   template <bidirectional_range _Range,
68             class _Proj = identity,
69             indirect_unary_predicate<projected<iterator_t<_Range>, _Proj>> _Pred>
70     requires permutable<iterator_t<_Range>>
71   _LIBCPP_HIDE_FROM_ABI borrowed_subrange_t<_Range>
72   operator()(_Range&& __range, _Pred __pred, _Proj __proj = {}) const {
73     return __stable_partition_fn_impl(ranges::begin(__range), ranges::end(__range), __pred, __proj);
74   }
75 };
76 
77 inline namespace __cpo {
78 inline constexpr auto stable_partition = __stable_partition{};
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_STABLE_PARTITION_H
89