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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_TRANSFORM_VIEW_H11#define _LIBCPP___RANGES_TRANSFORM_VIEW_H12 13#include <__compare/three_way_comparable.h>14#include <__concepts/constructible.h>15#include <__concepts/convertible_to.h>16#include <__concepts/derived_from.h>17#include <__concepts/equality_comparable.h>18#include <__concepts/invocable.h>19#include <__config>20#include <__functional/bind_back.h>21#include <__functional/invoke.h>22#include <__functional/perfect_forward.h>23#include <__iterator/concepts.h>24#include <__iterator/iterator_traits.h>25#include <__memory/addressof.h>26#include <__ranges/access.h>27#include <__ranges/all.h>28#include <__ranges/concepts.h>29#include <__ranges/empty.h>30#include <__ranges/movable_box.h>31#include <__ranges/range_adaptor.h>32#include <__ranges/size.h>33#include <__ranges/view_interface.h>34#include <__type_traits/conditional.h>35#include <__type_traits/decay.h>36#include <__type_traits/invoke.h>37#include <__type_traits/is_nothrow_constructible.h>38#include <__type_traits/is_object.h>39#include <__type_traits/is_reference.h>40#include <__type_traits/is_referenceable.h>41#include <__type_traits/maybe_const.h>42#include <__type_traits/remove_cvref.h>43#include <__utility/forward.h>44#include <__utility/in_place.h>45#include <__utility/move.h>46 47#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)48# pragma GCC system_header49#endif50 51_LIBCPP_PUSH_MACROS52#include <__undef_macros>53 54_LIBCPP_BEGIN_NAMESPACE_STD55 56#if _LIBCPP_STD_VER >= 2057 58namespace ranges {59 60template <class _Fn, class _View>61concept __regular_invocable_with_range_ref = regular_invocable<_Fn, range_reference_t<_View>>;62 63template <class _View, class _Fn>64concept __transform_view_constraints =65 view<_View> && is_object_v<_Fn> && regular_invocable<_Fn&, range_reference_t<_View>> &&66 __referenceable<invoke_result_t<_Fn&, range_reference_t<_View>>>;67 68# if _LIBCPP_STD_VER >= 2369template <input_range _View, move_constructible _Fn>70# else71template <input_range _View, copy_constructible _Fn>72# endif73 requires __transform_view_constraints<_View, _Fn>74class _LIBCPP_ABI_LLVM18_NO_UNIQUE_ADDRESS transform_view : public view_interface<transform_view<_View, _Fn>> {75 template <bool>76 class __iterator;77 template <bool>78 class __sentinel;79 80 _LIBCPP_NO_UNIQUE_ADDRESS __movable_box<_Fn> __func_;81 _LIBCPP_NO_UNIQUE_ADDRESS _View __base_ = _View();82 83public:84 _LIBCPP_HIDE_FROM_ABI transform_view()85 requires default_initializable<_View> && default_initializable<_Fn>86 = default;87 88 _LIBCPP_HIDE_FROM_ABI constexpr _LIBCPP_EXPLICIT_SINCE_CXX23 transform_view(_View __base, _Fn __func)89 : __func_(std::in_place, std::move(__func)), __base_(std::move(__base)) {}90 91 _LIBCPP_HIDE_FROM_ABI constexpr _View base() const&92 requires copy_constructible<_View>93 {94 return __base_;95 }96 _LIBCPP_HIDE_FROM_ABI constexpr _View base() && { return std::move(__base_); }97 98 _LIBCPP_HIDE_FROM_ABI constexpr __iterator<false> begin() { return __iterator<false>{*this, ranges::begin(__base_)}; }99 _LIBCPP_HIDE_FROM_ABI constexpr __iterator<true> begin() const100 requires range<const _View> && __regular_invocable_with_range_ref<const _Fn&, const _View>101 {102 return __iterator<true>(*this, ranges::begin(__base_));103 }104 105 _LIBCPP_HIDE_FROM_ABI constexpr __sentinel<false> end() { return __sentinel<false>(ranges::end(__base_)); }106 _LIBCPP_HIDE_FROM_ABI constexpr __iterator<false> end()107 requires common_range<_View>108 {109 return __iterator<false>(*this, ranges::end(__base_));110 }111 _LIBCPP_HIDE_FROM_ABI constexpr __sentinel<true> end() const112 requires range<const _View> && __regular_invocable_with_range_ref<const _Fn&, const _View>113 {114 return __sentinel<true>(ranges::end(__base_));115 }116 _LIBCPP_HIDE_FROM_ABI constexpr __iterator<true> end() const117 requires common_range<const _View> && __regular_invocable_with_range_ref<const _Fn&, const _View>118 {119 return __iterator<true>(*this, ranges::end(__base_));120 }121 122 _LIBCPP_HIDE_FROM_ABI constexpr auto size()123 requires sized_range<_View>124 {125 return ranges::size(__base_);126 }127 _LIBCPP_HIDE_FROM_ABI constexpr auto size() const128 requires sized_range<const _View>129 {130 return ranges::size(__base_);131 }132};133 134template <class _Range, class _Fn>135transform_view(_Range&&, _Fn) -> transform_view<views::all_t<_Range>, _Fn>;136 137template <class _View>138struct __transform_view_iterator_concept {139 using type _LIBCPP_NODEBUG = input_iterator_tag;140};141 142template <random_access_range _View>143struct __transform_view_iterator_concept<_View> {144 using type _LIBCPP_NODEBUG = random_access_iterator_tag;145};146 147template <bidirectional_range _View>148struct __transform_view_iterator_concept<_View> {149 using type _LIBCPP_NODEBUG = bidirectional_iterator_tag;150};151 152template <forward_range _View>153struct __transform_view_iterator_concept<_View> {154 using type _LIBCPP_NODEBUG = forward_iterator_tag;155};156 157template <class, class>158struct __transform_view_iterator_category_base {};159 160template <forward_range _View, class _Fn>161struct __transform_view_iterator_category_base<_View, _Fn> {162 using _Cat _LIBCPP_NODEBUG = typename iterator_traits<iterator_t<_View>>::iterator_category;163 164 using iterator_category =165 conditional_t< is_reference_v<invoke_result_t<_Fn&, range_reference_t<_View>>>,166 conditional_t< derived_from<_Cat, contiguous_iterator_tag>, random_access_iterator_tag, _Cat >,167 input_iterator_tag >;168};169 170# if _LIBCPP_STD_VER >= 23171template <input_range _View, move_constructible _Fn>172# else173template <input_range _View, copy_constructible _Fn>174# endif175 requires __transform_view_constraints<_View, _Fn>176template <bool _Const>177class transform_view<_View, _Fn>::__iterator178 : public __transform_view_iterator_category_base<_View, __maybe_const<_Const, _Fn>> {179 180 using _Parent _LIBCPP_NODEBUG = __maybe_const<_Const, transform_view>;181 using _Base _LIBCPP_NODEBUG = __maybe_const<_Const, _View>;182 183 _Parent* __parent_ = nullptr;184 185 template <bool>186 friend class transform_view<_View, _Fn>::__iterator;187 188 template <bool>189 friend class transform_view<_View, _Fn>::__sentinel;190 191public:192 iterator_t<_Base> __current_ = iterator_t<_Base>();193 194 using iterator_concept = typename __transform_view_iterator_concept<_View>::type;195 using value_type = remove_cvref_t<invoke_result_t<__maybe_const<_Const, _Fn>&, range_reference_t<_Base>>>;196 using difference_type = range_difference_t<_Base>;197 198 _LIBCPP_HIDE_FROM_ABI __iterator()199 requires default_initializable<iterator_t<_Base>>200 = default;201 202 _LIBCPP_HIDE_FROM_ABI constexpr __iterator(_Parent& __parent, iterator_t<_Base> __current)203 : __parent_(std::addressof(__parent)), __current_(std::move(__current)) {}204 205 // Note: `__i` should always be `__iterator<false>`, but directly using206 // `__iterator<false>` is ill-formed when `_Const` is false207 // (see http://wg21.link/class.copy.ctor#5).208 _LIBCPP_HIDE_FROM_ABI constexpr __iterator(__iterator<!_Const> __i)209 requires _Const && convertible_to<iterator_t<_View>, iterator_t<_Base>>210 : __parent_(__i.__parent_), __current_(std::move(__i.__current_)) {}211 212 _LIBCPP_HIDE_FROM_ABI constexpr const iterator_t<_Base>& base() const& noexcept { return __current_; }213 214 _LIBCPP_HIDE_FROM_ABI constexpr iterator_t<_Base> base() && { return std::move(__current_); }215 216 _LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) operator*() const217 noexcept(noexcept(std::invoke(*__parent_->__func_, *__current_))) {218 return std::invoke(*__parent_->__func_, *__current_);219 }220 221 _LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator++() {222 ++__current_;223 return *this;224 }225 226 _LIBCPP_HIDE_FROM_ABI constexpr void operator++(int) { ++__current_; }227 228 _LIBCPP_HIDE_FROM_ABI constexpr __iterator operator++(int)229 requires forward_range<_Base>230 {231 auto __tmp = *this;232 ++*this;233 return __tmp;234 }235 236 _LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator--()237 requires bidirectional_range<_Base>238 {239 --__current_;240 return *this;241 }242 243 _LIBCPP_HIDE_FROM_ABI constexpr __iterator operator--(int)244 requires bidirectional_range<_Base>245 {246 auto __tmp = *this;247 --*this;248 return __tmp;249 }250 251 _LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator+=(difference_type __n)252 requires random_access_range<_Base>253 {254 __current_ += __n;255 return *this;256 }257 258 _LIBCPP_HIDE_FROM_ABI constexpr __iterator& operator-=(difference_type __n)259 requires random_access_range<_Base>260 {261 __current_ -= __n;262 return *this;263 }264 265 _LIBCPP_HIDE_FROM_ABI constexpr decltype(auto) operator[](difference_type __n) const266 noexcept(noexcept(std::invoke(*__parent_->__func_, __current_[__n])))267 requires random_access_range<_Base>268 {269 return std::invoke(*__parent_->__func_, __current_[__n]);270 }271 272 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator& __x, const __iterator& __y)273 requires equality_comparable<iterator_t<_Base>>274 {275 return __x.__current_ == __y.__current_;276 }277 278 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<(const __iterator& __x, const __iterator& __y)279 requires random_access_range<_Base>280 {281 return __x.__current_ < __y.__current_;282 }283 284 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>(const __iterator& __x, const __iterator& __y)285 requires random_access_range<_Base>286 {287 return __x.__current_ > __y.__current_;288 }289 290 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator<=(const __iterator& __x, const __iterator& __y)291 requires random_access_range<_Base>292 {293 return __x.__current_ <= __y.__current_;294 }295 296 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator>=(const __iterator& __x, const __iterator& __y)297 requires random_access_range<_Base>298 {299 return __x.__current_ >= __y.__current_;300 }301 302 _LIBCPP_HIDE_FROM_ABI friend constexpr auto operator<=>(const __iterator& __x, const __iterator& __y)303 requires random_access_range<_Base> && three_way_comparable<iterator_t<_Base>>304 {305 return __x.__current_ <=> __y.__current_;306 }307 308 _LIBCPP_HIDE_FROM_ABI friend constexpr __iterator operator+(__iterator __i, difference_type __n)309 requires random_access_range<_Base>310 {311 return __iterator{*__i.__parent_, __i.__current_ + __n};312 }313 314 _LIBCPP_HIDE_FROM_ABI friend constexpr __iterator operator+(difference_type __n, __iterator __i)315 requires random_access_range<_Base>316 {317 return __iterator{*__i.__parent_, __i.__current_ + __n};318 }319 320 _LIBCPP_HIDE_FROM_ABI friend constexpr __iterator operator-(__iterator __i, difference_type __n)321 requires random_access_range<_Base>322 {323 return __iterator{*__i.__parent_, __i.__current_ - __n};324 }325 326 _LIBCPP_HIDE_FROM_ABI friend constexpr difference_type operator-(const __iterator& __x, const __iterator& __y)327 requires sized_sentinel_for<iterator_t<_Base>, iterator_t<_Base>>328 {329 return __x.__current_ - __y.__current_;330 }331};332 333# if _LIBCPP_STD_VER >= 23334template <input_range _View, move_constructible _Fn>335# else336template <input_range _View, copy_constructible _Fn>337# endif338 requires __transform_view_constraints<_View, _Fn>339template <bool _Const>340class transform_view<_View, _Fn>::__sentinel {341 using _Parent _LIBCPP_NODEBUG = __maybe_const<_Const, transform_view>;342 using _Base _LIBCPP_NODEBUG = __maybe_const<_Const, _View>;343 344 sentinel_t<_Base> __end_ = sentinel_t<_Base>();345 346 template <bool>347 friend class transform_view<_View, _Fn>::__iterator;348 349 template <bool>350 friend class transform_view<_View, _Fn>::__sentinel;351 352public:353 _LIBCPP_HIDE_FROM_ABI __sentinel() = default;354 355 _LIBCPP_HIDE_FROM_ABI constexpr explicit __sentinel(sentinel_t<_Base> __end) : __end_(__end) {}356 357 // Note: `__i` should always be `__sentinel<false>`, but directly using358 // `__sentinel<false>` is ill-formed when `_Const` is false359 // (see http://wg21.link/class.copy.ctor#5).360 _LIBCPP_HIDE_FROM_ABI constexpr __sentinel(__sentinel<!_Const> __i)361 requires _Const && convertible_to<sentinel_t<_View>, sentinel_t<_Base>>362 : __end_(std::move(__i.__end_)) {}363 364 _LIBCPP_HIDE_FROM_ABI constexpr sentinel_t<_Base> base() const { return __end_; }365 366 template <bool _OtherConst>367 requires sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>>368 _LIBCPP_HIDE_FROM_ABI friend constexpr bool operator==(const __iterator<_OtherConst>& __x, const __sentinel& __y) {369 return __x.__current_ == __y.__end_;370 }371 372 template <bool _OtherConst>373 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>>374 _LIBCPP_HIDE_FROM_ABI friend constexpr range_difference_t<__maybe_const<_OtherConst, _View>>375 operator-(const __iterator<_OtherConst>& __x, const __sentinel& __y) {376 return __x.__current_ - __y.__end_;377 }378 379 template <bool _OtherConst>380 requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<__maybe_const<_OtherConst, _View>>>381 _LIBCPP_HIDE_FROM_ABI friend constexpr range_difference_t<__maybe_const<_OtherConst, _View>>382 operator-(const __sentinel& __x, const __iterator<_OtherConst>& __y) {383 return __x.__end_ - __y.__current_;384 }385};386 387namespace views {388namespace __transform {389struct __fn {390 template <class _Range, class _Fn>391 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Range&& __range, _Fn&& __f) const392 noexcept(noexcept(transform_view(std::forward<_Range>(__range), std::forward<_Fn>(__f))))393 -> decltype(transform_view(std::forward<_Range>(__range), std::forward<_Fn>(__f))) {394 return transform_view(std::forward<_Range>(__range), std::forward<_Fn>(__f));395 }396 397 template <class _Fn>398 requires constructible_from<decay_t<_Fn>, _Fn>399 [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr auto operator()(_Fn&& __f) const400 noexcept(is_nothrow_constructible_v<decay_t<_Fn>, _Fn>) {401 return __pipeable(std::__bind_back(*this, std::forward<_Fn>(__f)));402 }403};404} // namespace __transform405 406inline namespace __cpo {407inline constexpr auto transform = __transform::__fn{};408} // namespace __cpo409} // namespace views410 411} // namespace ranges412 413#endif // _LIBCPP_STD_VER >= 20414 415_LIBCPP_END_NAMESPACE_STD416 417_LIBCPP_POP_MACROS418 419#endif // _LIBCPP___RANGES_TRANSFORM_VIEW_H420