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1// -*- C++ -*-2//===----------------------------------------------------------------------===//3//4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.5// See https://llvm.org/LICENSE.txt for license information.6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception7//8//===----------------------------------------------------------------------===//9 10#ifndef _LIBCPP___RANGES_REPEAT_VIEW_H11#define _LIBCPP___RANGES_REPEAT_VIEW_H12 13#include <__assert>14#include <__concepts/constructible.h>15#include <__concepts/same_as.h>16#include <__concepts/semiregular.h>17#include <__config>18#include <__cstddef/ptrdiff_t.h>19#include <__iterator/concepts.h>20#include <__iterator/iterator_traits.h>21#include <__iterator/unreachable_sentinel.h>22#include <__memory/addressof.h>23#include <__ranges/iota_view.h>24#include <__ranges/movable_box.h>25#include <__ranges/view_interface.h>26#include <__type_traits/decay.h>27#include <__type_traits/is_object.h>28#include <__type_traits/make_unsigned.h>29#include <__type_traits/remove_cv.h>30#include <__utility/forward.h>31#include <__utility/in_place.h>32#include <__utility/move.h>33#include <__utility/piecewise_construct.h>34#include <tuple>35 36#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)37# pragma GCC system_header38#endif39 40_LIBCPP_PUSH_MACROS41#include <__undef_macros>42 43_LIBCPP_BEGIN_NAMESPACE_STD44 45#if _LIBCPP_STD_VER >= 2346 47namespace ranges {48 49template <class _Tp>50concept __integer_like_with_usable_difference_type =51 __signed_integer_like<_Tp> || (__integer_like<_Tp> && weakly_incrementable<_Tp>);52 53template <class _Tp>54struct __repeat_view_iterator_difference {55 using type _LIBCPP_NODEBUG = _IotaDiffT<_Tp>;56};57 58template <__signed_integer_like _Tp>59struct __repeat_view_iterator_difference<_Tp> {60 using type _LIBCPP_NODEBUG = _Tp;61};62 63template <class _Tp>64using __repeat_view_iterator_difference_t _LIBCPP_NODEBUG = typename __repeat_view_iterator_difference<_Tp>::type;65 66namespace views::__drop {67struct __fn;68} // namespace views::__drop69 70namespace views::__take {71struct __fn;72} // namespace views::__take73 74template <move_constructible _Tp, semiregular _Bound = unreachable_sentinel_t>75 requires(is_object_v<_Tp> && same_as<_Tp, remove_cv_t<_Tp>> &&76 (__integer_like_with_usable_difference_type<_Bound> || same_as<_Bound, unreachable_sentinel_t>))77class _LIBCPP_ABI_LLVM18_NO_UNIQUE_ADDRESS repeat_view : public view_interface<repeat_view<_Tp, _Bound>> {78 friend struct views::__take::__fn;79 friend struct views::__drop::__fn;80 class __iterator;81 82public:83 _LIBCPP_HIDE_FROM_ABI repeat_view()84 requires default_initializable<_Tp>85 = default;86 87 _LIBCPP_HIDE_FROM_ABI constexpr explicit repeat_view(const _Tp& __value, _Bound __bound_sentinel = _Bound())88 requires copy_constructible<_Tp>89 : __value_(in_place, __value), __bound_(__bound_sentinel) {90 if constexpr (!same_as<_Bound, unreachable_sentinel_t>)91 _LIBCPP_ASSERT_UNCATEGORIZED(__bound_ >= 0, "The value of bound must be greater than or equal to 0");92 }93 94 _LIBCPP_HIDE_FROM_ABI constexpr explicit repeat_view(_Tp&& __value, _Bound __bound_sentinel = _Bound())95 : __value_(in_place, std::move(__value)), __bound_(__bound_sentinel) {96 if constexpr (!same_as<_Bound, unreachable_sentinel_t>)97 _LIBCPP_ASSERT_UNCATEGORIZED(__bound_ >= 0, "The value of bound must be greater than or equal to 0");98 }99 100 template <class... _TpArgs, class... _BoundArgs>101 requires(constructible_from<_Tp, _TpArgs...> && constructible_from<_Bound, _BoundArgs...>)102 _LIBCPP_HIDE_FROM_ABI constexpr explicit repeat_view(103 piecewise_construct_t, tuple<_TpArgs...> __value_args, tuple<_BoundArgs...> __bound_args = tuple<>{})104 : __value_(in_place, std::make_from_tuple<_Tp>(std::move(__value_args))),105 __bound_(std::make_from_tuple<_Bound>(std::move(__bound_args))) {106 if constexpr (!same_as<_Bound, unreachable_sentinel_t>)107 _LIBCPP_ASSERT_UNCATEGORIZED(108 __bound_ >= 0, "The behavior is undefined if Bound is not unreachable_sentinel_t and bound is negative");109 }110 111 _LIBCPP_HIDE_FROM_ABI constexpr __iterator begin() const { return __iterator(std::addressof(*__value_)); }112 113 _LIBCPP_HIDE_FROM_ABI constexpr __iterator end() const114 requires(!same_as<_Bound, unreachable_sentinel_t>)115 {116 return __iterator(std::addressof(*__value_), __bound_);117 }118 119 _LIBCPP_HIDE_FROM_ABI constexpr unreachable_sentinel_t end() const noexcept { return unreachable_sentinel; }120 121 _LIBCPP_HIDE_FROM_ABI constexpr auto size() const122 requires(!same_as<_Bound, unreachable_sentinel_t>)123 {124 return std::__to_unsigned_like(__bound_);125 }126 127private:128 _LIBCPP_NO_UNIQUE_ADDRESS __movable_box<_Tp> __value_;129 _LIBCPP_NO_UNIQUE_ADDRESS _Bound __bound_ = _Bound();130};131 132template <class _Tp, class _Bound = unreachable_sentinel_t>133repeat_view(_Tp, _Bound = _Bound()) -> repeat_view<_Tp, _Bound>;134 135// [range.repeat.iterator]136template <move_constructible _Tp, semiregular _Bound>137 requires(is_object_v<_Tp> && same_as<_Tp, remove_cv_t<_Tp>> &&138 (__integer_like_with_usable_difference_type<_Bound> || same_as<_Bound, unreachable_sentinel_t>))139class repeat_view<_Tp, _Bound>::__iterator {140 friend class repeat_view;141 142 using _IndexT _LIBCPP_NODEBUG = conditional_t<same_as<_Bound, unreachable_sentinel_t>, ptrdiff_t, _Bound>;143 144 _LIBCPP_HIDE_FROM_ABI constexpr explicit __iterator(const _Tp* __value, _IndexT __bound_sentinel = _IndexT())145 : __value_(__value), __current_(__bound_sentinel) {}146 147public:148 using iterator_concept = random_access_iterator_tag;149 using iterator_category = random_access_iterator_tag;150 using value_type = _Tp;151 using difference_type = __repeat_view_iterator_difference_t<_IndexT>;152 153 _LIBCPP_HIDE_FROM_ABI __iterator() = default;154 155 _LIBCPP_HIDE_FROM_ABI constexpr const _Tp& operator*() const noexcept { return *__value_; }156 157 _LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator++() {158 ++__current_;159 return *this;160 }161 162 _LIBCPP_HIDE_FROM_ABI constexpr __iterator operator++(int) {163 auto __tmp = *this;164 ++*this;165 return __tmp;166 }167 168 _LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator--() {169 if constexpr (!same_as<_Bound, unreachable_sentinel_t>)170 _LIBCPP_ASSERT_UNCATEGORIZED(__current_ > 0, "The value of bound must be greater than or equal to 0");171 --__current_;172 return *this;173 }174 175 _LIBCPP_HIDE_FROM_ABI constexpr __iterator operator--(int) {176 auto __tmp = *this;177 --*this;178 return __tmp;179 }180 181 _LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator+=(difference_type __n) {182 if constexpr (!same_as<_Bound, unreachable_sentinel_t>)183 _LIBCPP_ASSERT_UNCATEGORIZED(__current_ + __n >= 0, "The value of bound must be greater than or equal to 0");184 __current_ += __n;185 return *this;186 }187 188 _LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator-=(difference_type __n) {189 if constexpr (!same_as<_Bound, unreachable_sentinel_t>)190 _LIBCPP_ASSERT_UNCATEGORIZED(__current_ - __n >= 0, "The value of bound must be greater than or equal to 0");191 __current_ -= __n;192 return *this;193 }194 195 _LIBCPP_HIDE_FROM_ABI constexpr const _Tp& operator[](difference_type __n) const noexcept { return *(*this + __n); }196 197 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator& __x, const __iterator& __y) {198 return __x.__current_ == __y.__current_;199 }200 201 _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<=>(const __iterator& __x, const __iterator& __y) {202 return __x.__current_ <=> __y.__current_;203 }204 205 _LIBCPP_HIDE_FROM_ABI friend constexpr __iterator operator+(__iterator __i, difference_type __n) {206 __i += __n;207 return __i;208 }209 210 _LIBCPP_HIDE_FROM_ABI friend constexpr __iterator operator+(difference_type __n, __iterator __i) {211 __i += __n;212 return __i;213 }214 215 _LIBCPP_HIDE_FROM_ABI friend constexpr __iterator operator-(__iterator __i, difference_type __n) {216 __i -= __n;217 return __i;218 }219 220 _LIBCPP_HIDE_FROM_ABI friend constexpr difference_type operator-(const __iterator& __x, const __iterator& __y) {221 return static_cast<difference_type>(__x.__current_) - static_cast<difference_type>(__y.__current_);222 }223 224private:225 const _Tp* __value_ = nullptr;226 _IndexT __current_ = _IndexT();227};228 229// clang-format off230namespace views {231namespace __repeat {232struct __fn {233 template <class _Tp>234 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static constexpr auto operator()(_Tp&& __value)235 noexcept(noexcept(ranges::repeat_view<decay_t<_Tp>>(std::forward<_Tp>(__value))))236 -> decltype( ranges::repeat_view<decay_t<_Tp>>(std::forward<_Tp>(__value)))237 { return ranges::repeat_view<decay_t<_Tp>>(std::forward<_Tp>(__value)); }238 239 template <class _Tp, class _Bound>240 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI static constexpr auto operator()(_Tp&& __value, _Bound&& __bound_sentinel)241 noexcept(noexcept(ranges::repeat_view(std::forward<_Tp>(__value), std::forward<_Bound>(__bound_sentinel))))242 -> decltype( ranges::repeat_view(std::forward<_Tp>(__value), std::forward<_Bound>(__bound_sentinel)))243 { return ranges::repeat_view(std::forward<_Tp>(__value), std::forward<_Bound>(__bound_sentinel)); }244};245} // namespace __repeat246// clang-format on247 248inline namespace __cpo {249inline constexpr auto repeat = __repeat::__fn{};250} // namespace __cpo251} // namespace views252 253template <class _Tp>254inline constexpr bool __is_repeat_specialization = false;255 256template <class _Tp, class _Bound>257inline constexpr bool __is_repeat_specialization<repeat_view<_Tp, _Bound>> = true;258 259} // namespace ranges260 261#endif // _LIBCPP_STD_VER >= 23262 263_LIBCPP_END_NAMESPACE_STD264 265_LIBCPP_POP_MACROS266 267#endif // _LIBCPP___RANGES_REPEAT_VIEW_H268