xref: /freebsd-src/contrib/llvm-project/libcxx/include/__algorithm/ranges_search_n.h (revision 0fca6ea1d4eea4c934cfff25ac9ee8ad6fe95583)
1753f127fSDimitry Andric //===----------------------------------------------------------------------===//
2753f127fSDimitry Andric //
3753f127fSDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4753f127fSDimitry Andric // See https://llvm.org/LICENSE.txt for license information.
5753f127fSDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6753f127fSDimitry Andric //
7753f127fSDimitry Andric //===----------------------------------------------------------------------===//
8753f127fSDimitry Andric 
9753f127fSDimitry Andric #ifndef _LIBCPP___ALGORITHM_RANGES_SEARCH_N_H
10753f127fSDimitry Andric #define _LIBCPP___ALGORITHM_RANGES_SEARCH_N_H
11753f127fSDimitry Andric 
12753f127fSDimitry Andric #include <__algorithm/iterator_operations.h>
13753f127fSDimitry Andric #include <__algorithm/search_n.h>
14753f127fSDimitry Andric #include <__config>
15753f127fSDimitry Andric #include <__functional/identity.h>
16753f127fSDimitry Andric #include <__functional/ranges_operations.h>
17753f127fSDimitry Andric #include <__iterator/advance.h>
18753f127fSDimitry Andric #include <__iterator/concepts.h>
19753f127fSDimitry Andric #include <__iterator/distance.h>
20753f127fSDimitry Andric #include <__iterator/incrementable_traits.h>
21753f127fSDimitry Andric #include <__iterator/indirectly_comparable.h>
22753f127fSDimitry Andric #include <__iterator/iterator_traits.h>
23753f127fSDimitry Andric #include <__ranges/access.h>
24753f127fSDimitry Andric #include <__ranges/concepts.h>
25753f127fSDimitry Andric #include <__ranges/size.h>
26753f127fSDimitry Andric #include <__ranges/subrange.h>
27753f127fSDimitry Andric #include <__utility/move.h>
28bdd1243dSDimitry Andric #include <__utility/pair.h>
29753f127fSDimitry Andric 
30753f127fSDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
31753f127fSDimitry Andric #  pragma GCC system_header
32753f127fSDimitry Andric #endif
33753f127fSDimitry Andric 
34b3edf446SDimitry Andric _LIBCPP_PUSH_MACROS
35b3edf446SDimitry Andric #include <__undef_macros>
36b3edf446SDimitry Andric 
3706c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 20
38753f127fSDimitry Andric 
39753f127fSDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD
40753f127fSDimitry Andric 
41753f127fSDimitry Andric namespace ranges {
42753f127fSDimitry Andric namespace __search_n {
43753f127fSDimitry Andric struct __fn {
44753f127fSDimitry Andric   template <class _Iter1, class _Sent1, class _SizeT, class _Type, class _Pred, class _Proj>
45753f127fSDimitry Andric   _LIBCPP_HIDE_FROM_ABI static constexpr subrange<_Iter1> __ranges_search_n_impl(
46753f127fSDimitry Andric       _Iter1 __first, _Sent1 __last, _SizeT __count, const _Type& __value, _Pred& __pred, _Proj& __proj) {
47753f127fSDimitry Andric     if (__count == 0)
48753f127fSDimitry Andric       return {__first, __first};
49753f127fSDimitry Andric 
50753f127fSDimitry Andric     if constexpr (sized_sentinel_for<_Sent1, _Iter1>) {
51753f127fSDimitry Andric       auto __size = ranges::distance(__first, __last);
52753f127fSDimitry Andric       if (__size < __count) {
53753f127fSDimitry Andric         ranges::advance(__first, __last);
54753f127fSDimitry Andric         return {__first, __first};
55753f127fSDimitry Andric       }
56753f127fSDimitry Andric 
57753f127fSDimitry Andric       if constexpr (random_access_iterator<_Iter1>) {
58bdd1243dSDimitry Andric         auto __ret = std::__search_n_random_access_impl<_RangeAlgPolicy>(
59bdd1243dSDimitry Andric             __first, __last, __count, __value, __pred, __proj, __size);
60753f127fSDimitry Andric         return {std::move(__ret.first), std::move(__ret.second)};
61753f127fSDimitry Andric       }
62753f127fSDimitry Andric     }
63753f127fSDimitry Andric 
6406c3fb27SDimitry Andric     auto __ret = std::__search_n_forward_impl<_RangeAlgPolicy>(__first, __last, __count, __value, __pred, __proj);
65753f127fSDimitry Andric     return {std::move(__ret.first), std::move(__ret.second)};
66753f127fSDimitry Andric   }
67753f127fSDimitry Andric 
6806c3fb27SDimitry Andric   template <forward_iterator _Iter,
6906c3fb27SDimitry Andric             sentinel_for<_Iter> _Sent,
70753f127fSDimitry Andric             class _Type,
71753f127fSDimitry Andric             class _Pred = ranges::equal_to,
72753f127fSDimitry Andric             class _Proj = identity>
73753f127fSDimitry Andric     requires indirectly_comparable<_Iter, const _Type*, _Pred, _Proj>
74*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr subrange<_Iter>
7506c3fb27SDimitry Andric   operator()(_Iter __first,
7606c3fb27SDimitry Andric              _Sent __last,
77753f127fSDimitry Andric              iter_difference_t<_Iter> __count,
78753f127fSDimitry Andric              const _Type& __value,
79753f127fSDimitry Andric              _Pred __pred = {},
80753f127fSDimitry Andric              _Proj __proj = _Proj{}) const {
81753f127fSDimitry Andric     return __ranges_search_n_impl(__first, __last, __count, __value, __pred, __proj);
82753f127fSDimitry Andric   }
83753f127fSDimitry Andric 
84753f127fSDimitry Andric   template <forward_range _Range, class _Type, class _Pred = ranges::equal_to, class _Proj = identity>
85753f127fSDimitry Andric     requires indirectly_comparable<iterator_t<_Range>, const _Type*, _Pred, _Proj>
86*0fca6ea1SDimitry Andric   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr borrowed_subrange_t<_Range> operator()(
8706c3fb27SDimitry Andric       _Range&& __range, range_difference_t<_Range> __count, const _Type& __value, _Pred __pred = {}, _Proj __proj = {})
8806c3fb27SDimitry Andric       const {
89753f127fSDimitry Andric     auto __first = ranges::begin(__range);
90753f127fSDimitry Andric     if (__count <= 0)
91753f127fSDimitry Andric       return {__first, __first};
92753f127fSDimitry Andric     if constexpr (sized_range<_Range>) {
93753f127fSDimitry Andric       auto __size1 = ranges::size(__range);
94753f127fSDimitry Andric       if (__size1 < static_cast<range_size_t<_Range>>(__count)) {
95753f127fSDimitry Andric         ranges::advance(__first, ranges::end(__range));
96753f127fSDimitry Andric         return {__first, __first};
97753f127fSDimitry Andric       }
98753f127fSDimitry Andric     }
99753f127fSDimitry Andric 
100753f127fSDimitry Andric     return __ranges_search_n_impl(ranges::begin(__range), ranges::end(__range), __count, __value, __pred, __proj);
101753f127fSDimitry Andric   }
102753f127fSDimitry Andric };
103753f127fSDimitry Andric } // namespace __search_n
104753f127fSDimitry Andric 
105753f127fSDimitry Andric inline namespace __cpo {
106753f127fSDimitry Andric inline constexpr auto search_n = __search_n::__fn{};
107753f127fSDimitry Andric } // namespace __cpo
108753f127fSDimitry Andric } // namespace ranges
109753f127fSDimitry Andric 
110753f127fSDimitry Andric _LIBCPP_END_NAMESPACE_STD
111753f127fSDimitry Andric 
11206c3fb27SDimitry Andric #endif // _LIBCPP_STD_VER >= 20
113753f127fSDimitry Andric 
114b3edf446SDimitry Andric _LIBCPP_POP_MACROS
115b3edf446SDimitry Andric 
116753f127fSDimitry Andric #endif // _LIBCPP___ALGORITHM_RANGES_SEARCH_N_H
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