115 lines · c
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-exception6//7//===----------------------------------------------------------------------===//8 9#ifndef _LIBCPP___ALGORITHM_RANGES_SEARCH_N_H10#define _LIBCPP___ALGORITHM_RANGES_SEARCH_N_H11 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>29 30#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)31# pragma GCC system_header32#endif33 34_LIBCPP_PUSH_MACROS35#include <__undef_macros>36 37#if _LIBCPP_STD_VER >= 2038 39_LIBCPP_BEGIN_NAMESPACE_STD40 41namespace ranges {42struct __search_n {43 template <class _Iter1, class _Sent1, class _SizeT, class _Type, class _Pred, class _Proj>44 _LIBCPP_HIDE_FROM_ABI static constexpr subrange<_Iter1> __ranges_search_n_impl(45 _Iter1 __first, _Sent1 __last, _SizeT __count, const _Type& __value, _Pred& __pred, _Proj& __proj) {46 if (__count == 0)47 return {__first, __first};48 49 if constexpr (sized_sentinel_for<_Sent1, _Iter1>) {50 auto __size = ranges::distance(__first, __last);51 if (__size < __count) {52 ranges::advance(__first, __last);53 return {__first, __first};54 }55 56 if constexpr (random_access_iterator<_Iter1>) {57 auto __ret = std::__search_n_random_access_impl<_RangeAlgPolicy>(58 __first, __last, __count, __value, __pred, __proj, __size);59 return {std::move(__ret.first), std::move(__ret.second)};60 }61 }62 63 auto __ret = std::__search_n_forward_impl<_RangeAlgPolicy>(__first, __last, __count, __value, __pred, __proj);64 return {std::move(__ret.first), std::move(__ret.second)};65 }66 67 template <forward_iterator _Iter,68 sentinel_for<_Iter> _Sent,69 class _Type,70 class _Pred = ranges::equal_to,71 class _Proj = identity>72 requires indirectly_comparable<_Iter, const _Type*, _Pred, _Proj>73 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr subrange<_Iter>74 operator()(_Iter __first,75 _Sent __last,76 iter_difference_t<_Iter> __count,77 const _Type& __value,78 _Pred __pred = {},79 _Proj __proj = _Proj{}) const {80 return __ranges_search_n_impl(__first, __last, __count, __value, __pred, __proj);81 }82 83 template <forward_range _Range, class _Type, class _Pred = ranges::equal_to, class _Proj = identity>84 requires indirectly_comparable<iterator_t<_Range>, const _Type*, _Pred, _Proj>85 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr borrowed_subrange_t<_Range> operator()(86 _Range&& __range, range_difference_t<_Range> __count, const _Type& __value, _Pred __pred = {}, _Proj __proj = {})87 const {88 auto __first = ranges::begin(__range);89 if (__count <= 0)90 return {__first, __first};91 if constexpr (sized_range<_Range>) {92 auto __size1 = ranges::size(__range);93 if (__size1 < static_cast<range_size_t<_Range>>(__count)) {94 ranges::advance(__first, ranges::end(__range));95 return {__first, __first};96 }97 }98 99 return __ranges_search_n_impl(ranges::begin(__range), ranges::end(__range), __count, __value, __pred, __proj);100 }101};102 103inline namespace __cpo {104inline constexpr auto search_n = __search_n{};105} // namespace __cpo106} // namespace ranges107 108_LIBCPP_END_NAMESPACE_STD109 110#endif // _LIBCPP_STD_VER >= 20111 112_LIBCPP_POP_MACROS113 114#endif // _LIBCPP___ALGORITHM_RANGES_SEARCH_N_H115