Run DCE after a LoopFlatten test to reduce spurious output [nfc]
[llvm-project.git] / libcxx / include / __algorithm / ranges_search_n.h
blob4e53f30f71f9d64724e573b0ff2d1c15a9966f01
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 //===----------------------------------------------------------------------===//
9 #ifndef _LIBCPP___ALGORITHM_RANGES_SEARCH_N_H
10 #define _LIBCPP___ALGORITHM_RANGES_SEARCH_N_H
12 #include <__algorithm/iterator_operations.h>
13 #include <__algorithm/search_n.h>
14 #include <__config>
15 #include <__functional/identity.h>
16 #include <__functional/ranges_operations.h>
17 #include <__iterator/advance.h>
18 #include <__iterator/concepts.h>
19 #include <__iterator/distance.h>
20 #include <__iterator/incrementable_traits.h>
21 #include <__iterator/indirectly_comparable.h>
22 #include <__iterator/iterator_traits.h>
23 #include <__ranges/access.h>
24 #include <__ranges/concepts.h>
25 #include <__ranges/size.h>
26 #include <__ranges/subrange.h>
27 #include <__utility/move.h>
28 #include <__utility/pair.h>
30 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
31 # pragma GCC system_header
32 #endif
34 #if _LIBCPP_STD_VER >= 20
36 _LIBCPP_BEGIN_NAMESPACE_STD
38 namespace ranges {
39 namespace __search_n {
40 struct __fn {
41 template <class _Iter1, class _Sent1, class _SizeT, class _Type, class _Pred, class _Proj>
42 _LIBCPP_HIDE_FROM_ABI static constexpr subrange<_Iter1> __ranges_search_n_impl(
43 _Iter1 __first, _Sent1 __last, _SizeT __count, const _Type& __value, _Pred& __pred, _Proj& __proj) {
44 if (__count == 0)
45 return {__first, __first};
47 if constexpr (sized_sentinel_for<_Sent1, _Iter1>) {
48 auto __size = ranges::distance(__first, __last);
49 if (__size < __count) {
50 ranges::advance(__first, __last);
51 return {__first, __first};
54 if constexpr (random_access_iterator<_Iter1>) {
55 auto __ret = std::__search_n_random_access_impl<_RangeAlgPolicy>(
56 __first, __last, __count, __value, __pred, __proj, __size);
57 return {std::move(__ret.first), std::move(__ret.second)};
61 auto __ret = std::__search_n_forward_impl<_RangeAlgPolicy>(__first, __last, __count, __value, __pred, __proj);
62 return {std::move(__ret.first), std::move(__ret.second)};
65 template <forward_iterator _Iter,
66 sentinel_for<_Iter> _Sent,
67 class _Type,
68 class _Pred = ranges::equal_to,
69 class _Proj = identity>
70 requires indirectly_comparable<_Iter, const _Type*, _Pred, _Proj>
71 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr subrange<_Iter>
72 operator()(_Iter __first,
73 _Sent __last,
74 iter_difference_t<_Iter> __count,
75 const _Type& __value,
76 _Pred __pred = {},
77 _Proj __proj = _Proj{}) const {
78 return __ranges_search_n_impl(__first, __last, __count, __value, __pred, __proj);
81 template <forward_range _Range, class _Type, class _Pred = ranges::equal_to, class _Proj = identity>
82 requires indirectly_comparable<iterator_t<_Range>, const _Type*, _Pred, _Proj>
83 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr borrowed_subrange_t<_Range> operator()(
84 _Range&& __range, range_difference_t<_Range> __count, const _Type& __value, _Pred __pred = {}, _Proj __proj = {})
85 const {
86 auto __first = ranges::begin(__range);
87 if (__count <= 0)
88 return {__first, __first};
89 if constexpr (sized_range<_Range>) {
90 auto __size1 = ranges::size(__range);
91 if (__size1 < static_cast<range_size_t<_Range>>(__count)) {
92 ranges::advance(__first, ranges::end(__range));
93 return {__first, __first};
97 return __ranges_search_n_impl(ranges::begin(__range), ranges::end(__range), __count, __value, __pred, __proj);
100 } // namespace __search_n
102 inline namespace __cpo {
103 inline constexpr auto search_n = __search_n::__fn{};
104 } // namespace __cpo
105 } // namespace ranges
107 _LIBCPP_END_NAMESPACE_STD
109 #endif // _LIBCPP_STD_VER >= 20
111 #endif // _LIBCPP___ALGORITHM_RANGES_SEARCH_N_H