git://gcc.gnu.org / gcc.git / blame
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| 328b52d6 JW |
1 | // <ranges> -*- C++ -*- |
| 2 | ||
| 8d9254fc | 3 | // Copyright (C) 2019-2020 Free Software Foundation, Inc. |
| 328b52d6 JW |
4 | // |
| 5 | // This file is part of the GNU ISO C++ Library. This library is free | |
| 6 | // software; you can redistribute it and/or modify it under the | |
| 7 | // terms of the GNU General Public License as published by the | |
| 8 | // Free Software Foundation; either version 3, or (at your option) | |
| 9 | // any later version. | |
| 10 | ||
| 11 | // This library is distributed in the hope that it will be useful, | |
| 12 | // but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 13 | // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 14 | // GNU General Public License for more details. | |
| 15 | ||
| 16 | // Under Section 7 of GPL version 3, you are granted additional | |
| 17 | // permissions described in the GCC Runtime Library Exception, version | |
| 18 | // 3.1, as published by the Free Software Foundation. | |
| 19 | ||
| 20 | // You should have received __a copy of the GNU General Public License and | |
| 21 | // __a copy of the GCC Runtime Library Exception along with this program; | |
| 22 | // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
| 23 | // <http://www.gnu.org/licenses/>. | |
| 24 | ||
| 25 | /** @file include/ranges | |
| 26 | * This is a Standard C++ Library header. | |
| 27 | * @ingroup concepts | |
| 28 | */ | |
| 29 | ||
| 30 | #ifndef _GLIBCXX_RANGES | |
| 31 | #define _GLIBCXX_RANGES 1 | |
| 32 | ||
| 33 | #if __cplusplus > 201703L | |
| 34 | ||
| 35 | #pragma GCC system_header | |
| 36 | ||
| 37 | #include <concepts> | |
| 38 | ||
| 39 | #if __cpp_lib_concepts | |
| 40 | ||
| cba9ef06 | 41 | #include <bits/refwrap.h> |
| 37f33df7 JW |
42 | #include <compare> |
| 43 | #include <initializer_list> | |
| 328b52d6 | 44 | #include <iterator> |
| 37f33df7 JW |
45 | #include <limits> |
| 46 | #include <optional> | |
| cba9ef06 | 47 | #include <tuple> |
| 328b52d6 JW |
48 | |
| 49 | /** | |
| 50 | * @defgroup ranges Ranges | |
| 51 | * | |
| 52 | * Components for dealing with ranges of elements. | |
| 53 | */ | |
| 54 | ||
| 55 | namespace std _GLIBCXX_VISIBILITY(default) | |
| 56 | { | |
| 57 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
| 58 | namespace ranges | |
| 59 | { | |
| 60 | // [range.range] The range concept. | |
| 328b52d6 | 61 | // [range.sized] The sized_range concept. |
| a7922ddf | 62 | // Defined in <bits/range_access.h> |
| 328b52d6 JW |
63 | |
| 64 | // [range.refinements] | |
| a7922ddf | 65 | // Defined in <bits/range_access.h> |
| 37f33df7 JW |
66 | |
| 67 | struct view_base { }; | |
| 68 | ||
| 69 | namespace __detail | |
| 70 | { | |
| 71 | template<typename _Tp> | |
| 72 | concept __deep_const_range = range<_Tp> && range<const _Tp> | |
| 73 | && same_as<range_reference_t<_Tp>, range_reference_t<const _Tp>>; | |
| 74 | ||
| 75 | template<typename _Tp> | |
| 76 | inline constexpr bool __enable_view_impl | |
| 77 | = derived_from<_Tp, view_base> || (!__deep_const_range<_Tp>); | |
| 78 | ||
| 79 | template<typename _Tp> | |
| 80 | inline constexpr bool __enable_view_impl<std::initializer_list<_Tp>> | |
| 81 | = false; | |
| 82 | ||
| 83 | } // namespace __detail | |
| 84 | ||
| 85 | template<typename _Tp> | |
| 86 | inline constexpr bool enable_view | |
| 87 | = __detail::__enable_view_impl<remove_cv_t<_Tp>>; | |
| 88 | ||
| 89 | template<typename _Tp> | |
| 90 | concept view | |
| 91 | = range<_Tp> && movable<_Tp> && default_initializable<_Tp> | |
| 92 | && enable_view<_Tp>; | |
| 93 | ||
| b5b2e387 | 94 | /// A range which can be safely converted to a view. |
| 37f33df7 JW |
95 | template<typename _Tp> |
| 96 | concept viewable_range = range<_Tp> | |
| 26eae9ac | 97 | && (safe_range<_Tp> || view<remove_cvref_t<_Tp>>); |
| 37f33df7 JW |
98 | |
| 99 | namespace __detail | |
| 100 | { | |
| 101 | template<typename _Range> | |
| 102 | concept __simple_view = view<_Range> && range<const _Range> | |
| 103 | && same_as<iterator_t<_Range>, iterator_t<const _Range>> | |
| 104 | && same_as<sentinel_t<_Range>, sentinel_t<const _Range>>; | |
| 105 | ||
| 106 | template<typename _It> | |
| 107 | concept __has_arrow = input_iterator<_It> | |
| 108 | && (is_pointer_v<_It> || requires(_It __it) { __it.operator->(); }); | |
| 109 | ||
| 110 | template<typename _Tp, typename _Up> | |
| 111 | concept __not_same_as | |
| 112 | = !same_as<remove_cvref_t<_Tp>, remove_cvref_t<_Up>>; | |
| 113 | } // namespace __detail | |
| 114 | ||
| 115 | template<typename _Derived> | |
| 116 | requires is_class_v<_Derived> && same_as<_Derived, remove_cv_t<_Derived>> | |
| 117 | class view_interface : public view_base | |
| 118 | { | |
| 119 | private: | |
| 120 | constexpr _Derived& _M_derived() noexcept | |
| 121 | { | |
| 122 | static_assert(derived_from<_Derived, view_interface<_Derived>>); | |
| 123 | static_assert(view<_Derived>); | |
| 124 | return static_cast<_Derived&>(*this); | |
| 125 | } | |
| 126 | ||
| 127 | constexpr const _Derived& _M_derived() const noexcept | |
| 128 | { | |
| 129 | static_assert(derived_from<_Derived, view_interface<_Derived>>); | |
| 130 | static_assert(view<_Derived>); | |
| 131 | return static_cast<const _Derived&>(*this); | |
| 132 | } | |
| 133 | ||
| 134 | public: | |
| 135 | constexpr bool | |
| 136 | empty() requires forward_range<_Derived> | |
| 137 | { return ranges::begin(_M_derived()) == ranges::end(_M_derived()); } | |
| 138 | ||
| 139 | constexpr bool | |
| 140 | empty() const requires forward_range<const _Derived> | |
| 141 | { return ranges::begin(_M_derived()) == ranges::end(_M_derived()); } | |
| 142 | ||
| 143 | constexpr explicit | |
| 144 | operator bool() requires requires { ranges::empty(_M_derived()); } | |
| 145 | { return !ranges::empty(_M_derived()); } | |
| 146 | ||
| 147 | constexpr explicit | |
| 148 | operator bool() const requires requires { ranges::empty(_M_derived()); } | |
| 149 | { return !ranges::empty(_M_derived()); } | |
| 150 | ||
| 151 | constexpr auto | |
| 152 | data() requires contiguous_iterator<iterator_t<_Derived>> | |
| 153 | { return to_address(ranges::begin(_M_derived())); } | |
| 154 | ||
| 155 | constexpr auto | |
| 156 | data() const | |
| 157 | requires range<const _Derived> | |
| 158 | && contiguous_iterator<iterator_t<const _Derived>> | |
| 159 | { return to_address(ranges::begin(_M_derived())); } | |
| 160 | ||
| 161 | constexpr auto | |
| 162 | size() | |
| 163 | requires forward_range<_Derived> | |
| 164 | && sized_sentinel_for<sentinel_t<_Derived>, iterator_t<_Derived>> | |
| 165 | { return ranges::end(_M_derived()) - ranges::begin(_M_derived()); } | |
| 166 | ||
| 167 | constexpr auto | |
| 168 | size() const | |
| 169 | requires forward_range<const _Derived> | |
| 170 | && sized_sentinel_for<sentinel_t<const _Derived>, | |
| 171 | iterator_t<const _Derived>> | |
| 172 | { return ranges::end(_M_derived()) - ranges::begin(_M_derived()); } | |
| 173 | ||
| 174 | constexpr decltype(auto) | |
| 175 | front() requires forward_range<_Derived> | |
| 176 | { | |
| 177 | __glibcxx_assert(!empty()); | |
| 178 | return *ranges::begin(_M_derived()); | |
| 179 | } | |
| 180 | ||
| 181 | constexpr decltype(auto) | |
| 182 | front() const requires forward_range<const _Derived> | |
| 183 | { | |
| 184 | __glibcxx_assert(!empty()); | |
| 185 | return *ranges::begin(_M_derived()); | |
| 186 | } | |
| 187 | ||
| 188 | constexpr decltype(auto) | |
| 189 | back() | |
| 190 | requires bidirectional_range<_Derived> && common_range<_Derived> | |
| 191 | { | |
| 192 | __glibcxx_assert(!empty()); | |
| 193 | return *ranges::prev(ranges::end(_M_derived())); | |
| 194 | } | |
| 195 | ||
| 196 | constexpr decltype(auto) | |
| 197 | back() const | |
| 198 | requires bidirectional_range<const _Derived> | |
| 199 | && common_range<const _Derived> | |
| 200 | { | |
| 201 | __glibcxx_assert(!empty()); | |
| 202 | return *ranges::prev(ranges::end(_M_derived())); | |
| 203 | } | |
| 204 | ||
| 205 | template<random_access_range _Range = _Derived> | |
| 206 | constexpr decltype(auto) | |
| 207 | operator[](range_difference_t<_Range> __n) | |
| 208 | { return ranges::begin(_M_derived())[__n]; } | |
| 209 | ||
| 210 | template<random_access_range _Range = const _Derived> | |
| 211 | constexpr decltype(auto) | |
| 212 | operator[](range_difference_t<_Range> __n) const | |
| 213 | { return ranges::begin(_M_derived())[__n]; } | |
| 214 | }; | |
| 215 | ||
| 216 | namespace __detail | |
| 217 | { | |
| 218 | template<typename _Tp> | |
| 219 | concept __pair_like | |
| 220 | = !is_reference_v<_Tp> && requires(_Tp __t) | |
| 221 | { | |
| 222 | typename tuple_size<_Tp>::type; | |
| 223 | requires derived_from<tuple_size<_Tp>, integral_constant<size_t, 2>>; | |
| 224 | typename tuple_element_t<0, remove_const_t<_Tp>>; | |
| 225 | typename tuple_element_t<1, remove_const_t<_Tp>>; | |
| 226 | { get<0>(__t) } -> convertible_to<const tuple_element_t<0, _Tp>&>; | |
| 227 | { get<1>(__t) } -> convertible_to<const tuple_element_t<1, _Tp>&>; | |
| 228 | }; | |
| 229 | ||
| 230 | template<typename _Tp, typename _Up, typename _Vp> | |
| 231 | concept __pair_like_convertible_to | |
| 232 | = !range<_Tp> && __pair_like<remove_reference_t<_Tp>> | |
| 233 | && requires(_Tp&& __t) | |
| 234 | { | |
| 235 | { get<0>(std::forward<_Tp>(__t)) } -> convertible_to<_Up>; | |
| 236 | { get<1>(std::forward<_Tp>(__t)) } -> convertible_to<_Vp>; | |
| 237 | }; | |
| 238 | ||
| 239 | template<typename _Tp, typename _Up, typename _Vp> | |
| 240 | concept __pair_like_convertible_from | |
| 241 | = !range<_Tp> && __pair_like<_Tp> | |
| 242 | && constructible_from<_Tp, _Up, _Vp>; | |
| 243 | ||
| 244 | template<typename _Tp> | |
| 245 | concept __iterator_sentinel_pair | |
| 246 | = !range<_Tp> && __pair_like<_Tp> | |
| 247 | && sentinel_for<tuple_element_t<1, _Tp>, tuple_element_t<0, _Tp>>; | |
| 248 | ||
| 37f33df7 JW |
249 | } // namespace __detail |
| 250 | ||
| 251 | enum class subrange_kind : bool { unsized, sized }; | |
| 252 | ||
| 253 | template<input_or_output_iterator _It, sentinel_for<_It> _Sent = _It, | |
| 254 | subrange_kind _Kind = sized_sentinel_for<_Sent, _It> | |
| 255 | ? subrange_kind::sized : subrange_kind::unsized> | |
| 256 | requires (_Kind == subrange_kind::sized || !sized_sentinel_for<_Sent, _It>) | |
| 257 | class subrange : public view_interface<subrange<_It, _Sent, _Kind>> | |
| 258 | { | |
| 259 | private: | |
| cba9ef06 PP |
260 | // XXX: gcc complains when using constexpr here |
| 261 | static const bool _S_store_size | |
| 37f33df7 JW |
262 | = _Kind == subrange_kind::sized && !sized_sentinel_for<_Sent, _It>; |
| 263 | ||
| 264 | _It _M_begin = _It(); | |
| 265 | _Sent _M_end = _Sent(); | |
| 266 | ||
| 267 | template<typename, bool = _S_store_size> | |
| 268 | struct _Size | |
| 269 | { }; | |
| 270 | ||
| 271 | template<typename _Tp> | |
| 272 | struct _Size<_Tp, true> | |
| 273 | { __detail::__make_unsigned_like_t<_Tp> _M_size; }; | |
| 274 | ||
| 275 | [[no_unique_address]] _Size<iter_difference_t<_It>> _M_size = {}; | |
| 276 | ||
| 277 | public: | |
| 278 | subrange() = default; | |
| 279 | ||
| 280 | constexpr | |
| 281 | subrange(_It __i, _Sent __s) requires (!_S_store_size) | |
| 282 | : _M_begin(std::move(__i)), _M_end(__s) | |
| 283 | { } | |
| 284 | ||
| 285 | constexpr | |
| 286 | subrange(_It __i, _Sent __s, | |
| 287 | __detail::__make_unsigned_like_t<iter_difference_t<_It>> __n) | |
| 288 | requires (_Kind == subrange_kind::sized) | |
| 289 | : _M_begin(std::move(__i)), _M_end(__s) | |
| 290 | { | |
| 291 | using __detail::__to_unsigned_like; | |
| 292 | __glibcxx_assert(__n == __to_unsigned_like(ranges::distance(__i, __s))); | |
| 293 | if constexpr (_S_store_size) | |
| 294 | _M_size._M_size = __n; | |
| 295 | } | |
| 296 | ||
| 297 | template<__detail::__not_same_as<subrange> _Rng> | |
| b5b2e387 | 298 | requires safe_range<_Rng> |
| 37f33df7 JW |
299 | && convertible_to<iterator_t<_Rng>, _It> |
| 300 | && convertible_to<sentinel_t<_Rng>, _Sent> | |
| 301 | constexpr | |
| 302 | subrange(_Rng&& __r) requires (!_S_store_size || sized_range<_Rng>) | |
| 303 | : subrange{ranges::begin(__r), ranges::end(__r)} | |
| 304 | { | |
| 305 | if constexpr (_S_store_size) | |
| 306 | _M_size._M_size = ranges::size(__r); | |
| 307 | } | |
| 308 | ||
| b5b2e387 | 309 | template<safe_range _Rng> |
| 37f33df7 JW |
310 | requires convertible_to<iterator_t<_Rng>, _It> |
| 311 | && convertible_to<sentinel_t<_Rng>, _Sent> | |
| 312 | constexpr | |
| 313 | subrange(_Rng&& __r, | |
| 314 | __detail::__make_unsigned_like_t<iter_difference_t<_It>> __n) | |
| 315 | requires (_Kind == subrange_kind::sized) | |
| 316 | : subrange{ranges::begin(__r), ranges::end(__r), __n} | |
| 317 | { } | |
| 318 | ||
| 319 | template<__detail::__not_same_as<subrange> _PairLike> | |
| 320 | requires __detail::__pair_like_convertible_to<_PairLike, _It, _Sent> | |
| 321 | constexpr | |
| 322 | subrange(_PairLike&& __r) requires (!_S_store_size) | |
| 323 | : subrange{std::get<0>(std::forward<_PairLike>(__r)), | |
| 324 | std::get<1>(std::forward<_PairLike>(__r))} | |
| 325 | { } | |
| 326 | ||
| 327 | template<__detail::__pair_like_convertible_to<_It, _Sent> _PairLike> | |
| 328 | constexpr | |
| 329 | subrange(_PairLike&& __r, | |
| 330 | __detail::__make_unsigned_like_t<iter_difference_t<_It>> __n) | |
| 331 | requires (_Kind == subrange_kind::sized) | |
| 332 | : subrange{std::get<0>(std::forward<_PairLike>(__r)), | |
| 333 | std::get<1>(std::forward<_PairLike>(__r)), __n} | |
| 334 | { } | |
| 335 | ||
| 336 | template<__detail::__not_same_as<subrange> _PairLike> | |
| 337 | requires __detail::__pair_like_convertible_from<_PairLike, const _It&, | |
| 338 | const _Sent&> | |
| 339 | constexpr | |
| 340 | operator _PairLike() const | |
| 341 | { return _PairLike(_M_begin, _M_end); } | |
| 342 | ||
| 343 | constexpr _It | |
| 344 | begin() const requires copyable<_It> | |
| 345 | { return _M_begin; } | |
| 346 | ||
| 347 | [[nodiscard]] constexpr _It | |
| 348 | begin() requires (!copyable<_It>) | |
| 349 | { return std::move(_M_begin); } | |
| 350 | ||
| 351 | constexpr _Sent end() const { return _M_end; } | |
| 352 | ||
| 353 | constexpr bool empty() const { return _M_begin == _M_end; } | |
| 354 | ||
| 355 | constexpr __detail::__make_unsigned_like_t<iter_difference_t<_It>> | |
| 356 | size() const requires (_Kind == subrange_kind::sized) | |
| 357 | { | |
| 358 | if constexpr (_S_store_size) | |
| 359 | return _M_size._M_size; | |
| 360 | else | |
| 361 | return __detail::__to_unsigned_like(_M_end - _M_begin); | |
| 362 | } | |
| 363 | ||
| 364 | [[nodiscard]] constexpr subrange | |
| 365 | next(iter_difference_t<_It> __n = 1) const & | |
| 366 | requires forward_iterator<_It> | |
| 367 | { | |
| 368 | auto __tmp = *this; | |
| 369 | __tmp.advance(__n); | |
| 370 | return __tmp; | |
| 371 | } | |
| 372 | ||
| 373 | [[nodiscard]] constexpr subrange | |
| 374 | next(iter_difference_t<_It> __n = 1) && | |
| 375 | { | |
| 376 | advance(__n); | |
| 377 | return std::move(*this); | |
| 378 | } | |
| 379 | ||
| 380 | [[nodiscard]] constexpr subrange | |
| 381 | prev(iter_difference_t<_It> __n = 1) const | |
| 382 | requires bidirectional_iterator<_It> | |
| 383 | { | |
| 384 | auto __tmp = *this; | |
| 385 | __tmp.advance(--__n); | |
| 386 | return __tmp; | |
| 387 | } | |
| 388 | ||
| 389 | constexpr subrange& | |
| 390 | advance(iter_difference_t<_It> __n) | |
| 391 | { | |
| 392 | if constexpr (_S_store_size) | |
| 393 | { | |
| 394 | auto __d = __n - ranges::advance(_M_begin, __n, _M_end); | |
| 395 | if (__d >= 0) | |
| 396 | _M_size._M_size -= __detail::__to_unsigned_like(__d); | |
| 397 | else | |
| 398 | _M_size._M_size += __detail::__to_unsigned_like(-__d); | |
| 399 | } | |
| 400 | else | |
| 401 | ranges::advance(_M_begin, __n, _M_end); | |
| 402 | return *this; | |
| 403 | } | |
| 37f33df7 JW |
404 | }; |
| 405 | ||
| 406 | template<input_or_output_iterator _It, sentinel_for<_It> _Sent> | |
| 407 | subrange(_It, _Sent, | |
| 408 | __detail::__make_unsigned_like_t<iter_difference_t<_It>>) | |
| 409 | -> subrange<_It, _Sent, subrange_kind::sized>; | |
| 410 | ||
| 411 | template<__detail::__iterator_sentinel_pair _Pr> | |
| 412 | subrange(_Pr) | |
| 413 | -> subrange<tuple_element_t<0, _Pr>, tuple_element_t<1, _Pr>>; | |
| 414 | ||
| 415 | template<__detail::__iterator_sentinel_pair _Pr> | |
| 416 | subrange(_Pr, __detail::__make_unsigned_like_t<iter_difference_t< | |
| 417 | tuple_element_t<0, _Pr>>>) | |
| 418 | -> subrange<tuple_element_t<0, _Pr>, tuple_element_t<1, _Pr>, | |
| 419 | subrange_kind::sized>; | |
| 420 | ||
| b5b2e387 | 421 | template<safe_range _Rng> |
| 37f33df7 JW |
422 | subrange(_Rng&&) |
| 423 | -> subrange<iterator_t<_Rng>, sentinel_t<_Rng>, | |
| 424 | (sized_range<_Rng> | |
| 425 | || sized_sentinel_for<sentinel_t<_Rng>, iterator_t<_Rng>>) | |
| 426 | ? subrange_kind::sized : subrange_kind::unsized>; | |
| 427 | ||
| b5b2e387 | 428 | template<safe_range _Rng> |
| 37f33df7 JW |
429 | subrange(_Rng&&, |
| 430 | __detail::__make_unsigned_like_t<range_difference_t<_Rng>>) | |
| 431 | -> subrange<iterator_t<_Rng>, sentinel_t<_Rng>, subrange_kind::sized>; | |
| 432 | ||
| 433 | template<size_t _Num, class _It, class _Sent, subrange_kind _Kind> | |
| 434 | requires (_Num < 2) | |
| 435 | constexpr auto | |
| 436 | get(const subrange<_It, _Sent, _Kind>& __r) | |
| 437 | { | |
| 438 | if constexpr (_Num == 0) | |
| 439 | return __r.begin(); | |
| 440 | else | |
| 441 | return __r.end(); | |
| 442 | } | |
| 443 | ||
| 444 | template<size_t _Num, class _It, class _Sent, subrange_kind _Kind> | |
| 445 | requires (_Num < 2) | |
| 446 | constexpr auto | |
| 447 | get(subrange<_It, _Sent, _Kind>&& __r) | |
| 448 | { | |
| 449 | if constexpr (_Num == 0) | |
| 450 | return __r.begin(); | |
| 451 | else | |
| 452 | return __r.end(); | |
| 453 | } | |
| b5b2e387 JW |
454 | |
| 455 | template<input_or_output_iterator _It, sentinel_for<_It> _Sent, | |
| 456 | subrange_kind _Kind> | |
| 457 | inline constexpr bool | |
| 458 | enable_safe_range<subrange<_It, _Sent, _Kind>> = true; | |
| 459 | ||
| 37f33df7 JW |
460 | } // namespace ranges |
| 461 | ||
| 462 | using ranges::get; | |
| 463 | ||
| 464 | namespace ranges | |
| 465 | { | |
| 466 | /// Type returned by algorithms instead of a dangling iterator or subrange. | |
| 467 | struct dangling | |
| 468 | { | |
| 469 | constexpr dangling() noexcept = default; | |
| 470 | template<typename... _Args> | |
| 471 | constexpr dangling(_Args&&...) noexcept { } | |
| 472 | }; | |
| 473 | ||
| b5b2e387 JW |
474 | template<range _Range> |
| 475 | using safe_iterator_t = conditional_t<safe_range<_Range>, | |
| 476 | iterator_t<_Range>, | |
| 477 | dangling>; | |
| 478 | ||
| 479 | template<range _Range> | |
| 480 | using safe_subrange_t = conditional_t<safe_range<_Range>, | |
| 481 | subrange<iterator_t<_Range>>, | |
| 482 | dangling>; | |
| 483 | ||
| 37f33df7 | 484 | template<typename _Tp> requires is_object_v<_Tp> |
| b5b2e387 JW |
485 | class empty_view |
| 486 | : public view_interface<empty_view<_Tp>> | |
| 37f33df7 JW |
487 | { |
| 488 | public: | |
| 489 | static constexpr _Tp* begin() noexcept { return nullptr; } | |
| 490 | static constexpr _Tp* end() noexcept { return nullptr; } | |
| 491 | static constexpr _Tp* data() noexcept { return nullptr; } | |
| 492 | static constexpr size_t size() noexcept { return 0; } | |
| 493 | static constexpr bool empty() noexcept { return true; } | |
| 37f33df7 JW |
494 | }; |
| 495 | ||
| b5b2e387 JW |
496 | template<typename _Tp> |
| 497 | inline constexpr bool enable_safe_range<empty_view<_Tp>> = true; | |
| 498 | ||
| 37f33df7 JW |
499 | namespace __detail |
| 500 | { | |
| 501 | template<copy_constructible _Tp> requires is_object_v<_Tp> | |
| 502 | struct __box : std::optional<_Tp> | |
| 503 | { | |
| 504 | using std::optional<_Tp>::optional; | |
| 505 | ||
| 506 | constexpr | |
| 507 | __box() | |
| 508 | noexcept(is_nothrow_default_constructible_v<_Tp>) | |
| 509 | requires default_initializable<_Tp> | |
| 510 | : std::optional<_Tp>{std::in_place} | |
| 511 | { } | |
| 512 | ||
| cba9ef06 PP |
513 | __box(const __box&) = default; |
| 514 | __box(__box&&) = default; | |
| 515 | ||
| 37f33df7 JW |
516 | using std::optional<_Tp>::operator=; |
| 517 | ||
| 518 | __box& | |
| 519 | operator=(const __box& __that) | |
| 520 | noexcept(is_nothrow_copy_constructible_v<_Tp>) | |
| 521 | requires (!assignable_from<_Tp&, const _Tp&>) | |
| 522 | { | |
| 523 | if ((bool)__that) | |
| 524 | this->emplace(*__that); | |
| 525 | else | |
| 526 | this->reset(); | |
| 527 | return *this; | |
| 528 | } | |
| 529 | ||
| 530 | __box& | |
| 531 | operator=(__box&& __that) | |
| 532 | noexcept(is_nothrow_move_constructible_v<_Tp>) | |
| 533 | requires (!assignable_from<_Tp&, _Tp>) | |
| 534 | { | |
| 535 | if ((bool)__that) | |
| 536 | this->emplace(std::move(*__that)); | |
| 537 | else | |
| 538 | this->reset(); | |
| 539 | return *this; | |
| 540 | } | |
| 541 | }; | |
| 542 | ||
| 543 | } // namespace __detail | |
| 544 | ||
| 545 | /// A view that contains exactly one element. | |
| 546 | template<copy_constructible _Tp> requires is_object_v<_Tp> | |
| 547 | class single_view : public view_interface<single_view<_Tp>> | |
| 548 | { | |
| 549 | public: | |
| 550 | single_view() = default; | |
| 551 | ||
| 552 | constexpr explicit | |
| 553 | single_view(const _Tp& __t) | |
| 554 | : _M_value(__t) | |
| 555 | { } | |
| 556 | ||
| 557 | constexpr explicit | |
| 558 | single_view(_Tp&& __t) | |
| 559 | : _M_value(std::move(__t)) | |
| 560 | { } | |
| 561 | ||
| 562 | template<typename... _Args> | |
| 563 | requires constructible_from<_Tp, _Args...> | |
| 564 | constexpr | |
| 565 | single_view(in_place_t, _Args&&... __args) | |
| 566 | : _M_value{in_place, std::forward<_Args>(__args)...} | |
| 567 | { } | |
| 568 | ||
| 569 | constexpr _Tp* | |
| 570 | begin() noexcept | |
| 571 | { return data(); } | |
| 572 | ||
| 573 | constexpr const _Tp* | |
| 574 | begin() const noexcept | |
| 575 | { return data(); } | |
| 576 | ||
| 577 | constexpr _Tp* | |
| 578 | end() noexcept | |
| 579 | { return data() + 1; } | |
| 580 | ||
| 581 | constexpr const _Tp* | |
| 582 | end() const noexcept | |
| 583 | { return data() + 1; } | |
| 584 | ||
| 585 | static constexpr size_t | |
| 586 | size() noexcept | |
| 587 | { return 1; } | |
| 588 | ||
| 589 | constexpr _Tp* | |
| 590 | data() noexcept | |
| 591 | { return _M_value.operator->(); } | |
| 592 | ||
| 593 | constexpr const _Tp* | |
| 594 | data() const noexcept | |
| 595 | { return _M_value.operator->(); } | |
| 596 | ||
| 597 | private: | |
| 598 | __detail::__box<_Tp> _M_value; | |
| 599 | }; | |
| 600 | ||
| 601 | namespace __detail | |
| 602 | { | |
| 603 | template<typename _Wp> | |
| 604 | constexpr auto __to_signed_like(_Wp __w) noexcept | |
| 605 | { | |
| 606 | if constexpr (!integral<_Wp>) | |
| 607 | return iter_difference_t<_Wp>(); | |
| 608 | else if constexpr (sizeof(iter_difference_t<_Wp>) > sizeof(_Wp)) | |
| 609 | return iter_difference_t<_Wp>(__w); | |
| 610 | else if constexpr (sizeof(ptrdiff_t) > sizeof(_Wp)) | |
| 611 | return ptrdiff_t(__w); | |
| 612 | else if constexpr (sizeof(long long) > sizeof(_Wp)) | |
| 613 | return (long long)(__w); | |
| 614 | #ifdef __SIZEOF_INT128__ | |
| 615 | else if constexpr (__SIZEOF_INT128__ > sizeof(_Wp)) | |
| 616 | return __int128(__w); | |
| 617 | #endif | |
| 618 | else | |
| 619 | return __max_diff_type(__w); | |
| 620 | } | |
| 621 | ||
| 622 | template<typename _Wp> | |
| 623 | using __iota_diff_t = decltype(__to_signed_like(std::declval<_Wp>())); | |
| 624 | ||
| 625 | template<typename _It> | |
| 626 | concept __decrementable = incrementable<_It> | |
| 627 | && requires(_It __i) | |
| 628 | { | |
| 629 | { --__i } -> same_as<_It&>; | |
| 630 | { __i-- } -> same_as<_It>; | |
| 631 | }; | |
| 632 | ||
| 633 | template<typename _It> | |
| 634 | concept __advanceable = __decrementable<_It> && totally_ordered<_It> | |
| 635 | && requires( _It __i, const _It __j, const __iota_diff_t<_It> __n) | |
| 636 | { | |
| 637 | { __i += __n } -> same_as<_It&>; | |
| 638 | { __i -= __n } -> same_as<_It&>; | |
| 639 | _It(__j + __n); | |
| 640 | _It(__n + __j); | |
| 641 | _It(__j - __n); | |
| 642 | { __j - __j } -> convertible_to<__iota_diff_t<_It>>; | |
| 643 | }; | |
| 644 | ||
| 645 | } // namespace __detail | |
| 646 | ||
| 647 | template<weakly_incrementable _Winc, | |
| 648 | semiregular _Bound = unreachable_sentinel_t> | |
| 649 | requires std::__detail::__weakly_eq_cmp_with<_Winc, _Bound> | |
| 650 | class iota_view : public view_interface<iota_view<_Winc, _Bound>> | |
| 651 | { | |
| 652 | private: | |
| 653 | struct _Iterator | |
| 654 | { | |
| 655 | private: | |
| 656 | static auto | |
| 657 | _S_iter_cat() | |
| 658 | { | |
| 659 | using namespace __detail; | |
| 660 | if constexpr (__advanceable<_Winc>) | |
| 661 | return random_access_iterator_tag{}; | |
| 662 | else if constexpr (__decrementable<_Winc>) | |
| 663 | return bidirectional_iterator_tag{}; | |
| 664 | else if constexpr (incrementable<_Winc>) | |
| 665 | return forward_iterator_tag{}; | |
| 666 | else | |
| 667 | return input_iterator_tag{}; | |
| 668 | } | |
| 669 | ||
| 670 | public: | |
| 671 | using iterator_category = decltype(_S_iter_cat()); | |
| 672 | using value_type = _Winc; | |
| 673 | using difference_type = __detail::__iota_diff_t<_Winc>; | |
| 674 | ||
| 675 | _Iterator() = default; | |
| 676 | ||
| 677 | constexpr explicit | |
| 678 | _Iterator(_Winc __value) | |
| 679 | : _M_value(__value) { } | |
| 680 | ||
| 681 | constexpr _Winc | |
| 682 | operator*() const noexcept(is_nothrow_copy_constructible_v<_Winc>) | |
| 683 | { return _M_value; } | |
| 684 | ||
| 685 | constexpr _Iterator& | |
| 686 | operator++() | |
| 687 | { | |
| 688 | ++_M_value; | |
| 689 | return *this; | |
| 690 | } | |
| 691 | ||
| 692 | constexpr void | |
| 693 | operator++(int) | |
| 694 | { ++*this; } | |
| 695 | ||
| 696 | constexpr _Iterator | |
| 697 | operator++(int) requires incrementable<_Winc> | |
| 698 | { | |
| 699 | auto __tmp = *this; | |
| 700 | ++*this; | |
| 701 | return __tmp; | |
| 702 | } | |
| 703 | ||
| 704 | constexpr _Iterator& | |
| 705 | operator--() requires __detail::__decrementable<_Winc> | |
| 706 | { | |
| 707 | --_M_value; | |
| 708 | return *this; | |
| 709 | } | |
| 710 | ||
| 711 | constexpr _Iterator | |
| 712 | operator--(int) requires __detail::__decrementable<_Winc> | |
| 713 | { | |
| 714 | auto __tmp = *this; | |
| 715 | --*this; | |
| 716 | return __tmp; | |
| 717 | } | |
| 718 | ||
| 719 | constexpr _Iterator& | |
| 720 | operator+=(difference_type __n) requires __detail::__advanceable<_Winc> | |
| 721 | { | |
| 2a0f6c61 JW |
722 | using __detail::__is_integer_like; |
| 723 | using __detail::__is_signed_integer_like; | |
| 37f33df7 JW |
724 | if constexpr (__is_integer_like<_Winc> |
| 725 | && !__is_signed_integer_like<_Winc>) | |
| 726 | { | |
| 727 | if (__n >= difference_type(0)) | |
| 728 | _M_value += static_cast<_Winc>(__n); | |
| 729 | else | |
| 730 | _M_value -= static_cast<_Winc>(-__n); | |
| 731 | } | |
| 732 | else | |
| 733 | _M_value += __n; | |
| 734 | return *this; | |
| 735 | } | |
| 736 | ||
| 737 | constexpr _Iterator& | |
| 738 | operator-=(difference_type __n) requires __detail::__advanceable<_Winc> | |
| 739 | { | |
| 2a0f6c61 JW |
740 | using __detail::__is_integer_like; |
| 741 | using __detail::__is_signed_integer_like; | |
| 37f33df7 JW |
742 | if constexpr (__is_integer_like<_Winc> |
| 743 | && !__is_signed_integer_like<_Winc>) | |
| 744 | { | |
| 745 | if (__n >= difference_type(0)) | |
| 746 | _M_value -= static_cast<_Winc>(__n); | |
| 747 | else | |
| 748 | _M_value += static_cast<_Winc>(-__n); | |
| 749 | } | |
| 750 | else | |
| 751 | _M_value -= __n; | |
| 752 | return *this; | |
| 753 | } | |
| 754 | ||
| 755 | constexpr _Winc | |
| 756 | operator[](difference_type __n) const | |
| 757 | requires __detail::__advanceable<_Winc> | |
| 758 | { return _Winc(_M_value + __n); } | |
| 759 | ||
| 760 | friend constexpr bool | |
| 761 | operator==(const _Iterator& __x, const _Iterator& __y) | |
| 762 | requires equality_comparable<_Winc> | |
| 763 | { return __x._M_value == __y._M_value; } | |
| 764 | ||
| 765 | friend constexpr bool | |
| 766 | operator<(const _Iterator& __x, const _Iterator& __y) | |
| 767 | requires totally_ordered<_Winc> | |
| 768 | { return __x._M_value < __y._M_value; } | |
| 769 | ||
| 770 | friend constexpr bool | |
| 771 | operator>(const _Iterator& __x, const _Iterator& __y) | |
| 772 | requires totally_ordered<_Winc> | |
| 773 | { return __y < __x; } | |
| 774 | ||
| 775 | friend constexpr bool | |
| 776 | operator<=(const _Iterator& __x, const _Iterator& __y) | |
| 777 | requires totally_ordered<_Winc> | |
| 778 | { return !(__y < __x); } | |
| 779 | ||
| 780 | friend constexpr bool | |
| 781 | operator>=(const _Iterator& __x, const _Iterator& __y) | |
| 782 | requires totally_ordered<_Winc> | |
| 783 | { return !(__x < __y); } | |
| 784 | ||
| 5713834e JW |
785 | #ifdef __cpp_lib_three_way_comparison |
| 786 | friend constexpr auto | |
| 37f33df7 JW |
787 | operator<=>(const _Iterator& __x, const _Iterator& __y) |
| 788 | requires totally_ordered<_Winc> && three_way_comparable<_Winc> | |
| 789 | { return __x._M_value <=> __y._M_value; } | |
| 790 | #endif | |
| 791 | ||
| 792 | friend constexpr _Iterator | |
| 793 | operator+(_Iterator __i, difference_type __n) | |
| 794 | requires __detail::__advanceable<_Winc> | |
| 795 | { return __i += __n; } | |
| 796 | ||
| 797 | friend constexpr _Iterator | |
| 798 | operator+(difference_type __n, _Iterator __i) | |
| 799 | requires __detail::__advanceable<_Winc> | |
| 800 | { return __i += __n; } | |
| 801 | ||
| 802 | friend constexpr _Iterator | |
| 803 | operator-(_Iterator __i, difference_type __n) | |
| 804 | requires __detail::__advanceable<_Winc> | |
| 805 | { return __i -= __n; } | |
| 806 | ||
| 807 | friend constexpr difference_type | |
| 808 | operator-(const _Iterator& __x, const _Iterator& __y) | |
| 809 | requires __detail::__advanceable<_Winc> | |
| 810 | { | |
| 2a0f6c61 JW |
811 | using __detail::__is_integer_like; |
| 812 | using __detail::__is_signed_integer_like; | |
| 37f33df7 JW |
813 | using _Dt = difference_type; |
| 814 | if constexpr (__is_integer_like<_Winc>) | |
| 815 | { | |
| 816 | if constexpr (__is_signed_integer_like<_Winc>) | |
| 817 | return _Dt(_Dt(__x._M_value) - _Dt(__y._M_value)); | |
| 818 | else | |
| 819 | return (__y._M_value > __x._M_value) | |
| 820 | ? _Dt(-_Dt(__y._M_value - __x._M_value)) | |
| 821 | : _Dt(__x._M_value - __y._M_value); | |
| 822 | } | |
| 823 | else | |
| 824 | return __x._M_value - __y._M_value; | |
| 825 | } | |
| 826 | ||
| 827 | private: | |
| 828 | _Winc _M_value = _Winc(); | |
| 829 | }; | |
| 830 | ||
| 831 | struct _Sentinel | |
| 832 | { | |
| 833 | private: | |
| 834 | _Bound _M_bound = _Bound(); | |
| 835 | ||
| 836 | public: | |
| 837 | _Sentinel() = default; | |
| 838 | ||
| 839 | constexpr explicit | |
| 840 | _Sentinel(_Bound __bound) | |
| 841 | : _M_bound(__bound) { } | |
| 842 | ||
| 843 | friend constexpr bool | |
| 844 | operator==(const _Iterator& __x, const _Sentinel& __y) | |
| 845 | { return __x._M_value == __y._M_bound; } | |
| 846 | ||
| 847 | friend constexpr iter_difference_t<_Winc> | |
| 848 | operator-(const _Iterator& __x, const _Sentinel& __y) | |
| 849 | requires sized_sentinel_for<_Bound, _Winc> | |
| 850 | { return __x._M_value - __y._M_bound; } | |
| 851 | ||
| 852 | friend constexpr iter_difference_t<_Winc> | |
| 853 | operator-(const _Sentinel& __x, const _Iterator& __y) | |
| 854 | requires sized_sentinel_for<_Bound, _Winc> | |
| 855 | { return -(__y - __x); } | |
| 856 | }; | |
| 857 | ||
| 858 | _Winc _M_value = _Winc(); | |
| 859 | _Bound _M_bound = _Bound(); | |
| 860 | ||
| 861 | public: | |
| 862 | iota_view() = default; | |
| 863 | ||
| 864 | constexpr explicit | |
| 865 | iota_view(_Winc __value) | |
| 866 | : _M_value(__value) | |
| 867 | { } | |
| 868 | ||
| 869 | constexpr | |
| 870 | iota_view(type_identity_t<_Winc> __value, | |
| 871 | type_identity_t<_Bound> __bound) | |
| 872 | : _M_value(__value), _M_bound(__bound) | |
| 873 | { | |
| 874 | if constexpr (totally_ordered_with<_Winc, _Bound>) | |
| 572992c8 JW |
875 | { |
| 876 | __glibcxx_assert( bool(__value <= __bound) ); | |
| 877 | } | |
| 37f33df7 JW |
878 | } |
| 879 | ||
| 880 | constexpr _Iterator | |
| 881 | begin() const { return _Iterator{_M_value}; } | |
| 882 | ||
| 883 | constexpr auto | |
| 884 | end() const | |
| 885 | { | |
| 886 | if constexpr (same_as<_Bound, unreachable_sentinel_t>) | |
| 887 | return unreachable_sentinel; | |
| 888 | else | |
| 889 | return _Sentinel{_M_bound}; | |
| 890 | } | |
| 891 | ||
| 892 | constexpr _Iterator | |
| 893 | end() const requires same_as<_Winc, _Bound> | |
| 894 | { return _Iterator{_M_bound}; } | |
| 895 | ||
| 896 | constexpr auto | |
| 897 | size() const | |
| 898 | requires (same_as<_Winc, _Bound> && __detail::__advanceable<_Winc>) | |
| 899 | || (integral<_Winc> && integral<_Bound>) | |
| 900 | || sized_sentinel_for<_Bound, _Winc> | |
| 901 | { | |
| 2a0f6c61 JW |
902 | using __detail::__is_integer_like; |
| 903 | using __detail::__to_unsigned_like; | |
| 37f33df7 JW |
904 | if constexpr (__is_integer_like<_Winc> && __is_integer_like<_Bound>) |
| 905 | return (_M_value < 0) | |
| 906 | ? ((_M_bound < 0) | |
| 907 | ? __to_unsigned_like(-_M_value) - __to_unsigned_like(-_M_bound) | |
| 908 | : __to_unsigned_like(_M_bound) + __to_unsigned_like(-_M_value)) | |
| 909 | : __to_unsigned_like(_M_bound) - __to_unsigned_like(_M_value); | |
| 910 | else | |
| 911 | return __to_unsigned_like(_M_bound - _M_value); | |
| 912 | } | |
| 913 | }; | |
| 914 | ||
| 915 | template<typename _Winc, typename _Bound> | |
| 916 | requires (!__detail::__is_integer_like<_Winc> | |
| 917 | || !__detail::__is_integer_like<_Bound> | |
| 918 | || (__detail::__is_signed_integer_like<_Winc> | |
| 919 | == __detail::__is_signed_integer_like<_Bound>)) | |
| 920 | iota_view(_Winc, _Bound) -> iota_view<_Winc, _Bound>; | |
| 921 | ||
| b5b2e387 JW |
922 | template<weakly_incrementable _Winc, semiregular _Bound> |
| 923 | inline constexpr bool enable_safe_range<iota_view<_Winc, _Bound>> = true; | |
| 924 | ||
| 37f33df7 JW |
925 | namespace views |
| 926 | { | |
| 927 | template<typename _Tp> | |
| 928 | inline constexpr empty_view<_Tp> empty{}; | |
| 929 | ||
| 930 | struct _Single | |
| 931 | { | |
| 932 | template<typename _Tp> | |
| cba9ef06 | 933 | constexpr auto |
| 37f33df7 JW |
934 | operator()(_Tp&& __e) const |
| 935 | { return single_view{std::forward<_Tp>(__e)}; } | |
| 936 | }; | |
| 937 | ||
| 938 | inline constexpr _Single single{}; | |
| 939 | ||
| 940 | struct _Iota | |
| 941 | { | |
| 942 | template<typename _Tp> | |
| cba9ef06 | 943 | constexpr auto |
| 37f33df7 JW |
944 | operator()(_Tp&& __e) const |
| 945 | { return iota_view{std::forward<_Tp>(__e)}; } | |
| 946 | ||
| 947 | template<typename _Tp, typename _Up> | |
| cba9ef06 | 948 | constexpr auto |
| 37f33df7 JW |
949 | operator()(_Tp&& __e, _Up&& __f) const |
| 950 | { return iota_view{std::forward<_Tp>(__e), std::forward<_Tp>(__f)}; } | |
| 951 | }; | |
| 952 | ||
| 953 | inline constexpr _Iota iota{}; | |
| cba9ef06 PP |
954 | } // namespace views |
| 955 | ||
| b7903d9f PP |
956 | namespace __detail |
| 957 | { | |
| 958 | template<typename _Val, typename _CharT, typename _Traits> | |
| 959 | concept __stream_extractable | |
| 960 | = requires(basic_istream<_CharT, _Traits>& is, _Val& t) { is >> t; }; | |
| 961 | } // namespace __detail | |
| 962 | ||
| 963 | template<movable _Val, typename _CharT, typename _Traits> | |
| 964 | requires default_initializable<_Val> | |
| 965 | && __detail::__stream_extractable<_Val, _CharT, _Traits> | |
| 966 | class basic_istream_view | |
| 967 | : public view_interface<basic_istream_view<_Val, _CharT, _Traits>> | |
| 968 | { | |
| 969 | public: | |
| 970 | basic_istream_view() = default; | |
| 971 | ||
| 972 | constexpr explicit | |
| 973 | basic_istream_view(basic_istream<_CharT, _Traits>& __stream) | |
| 974 | : _M_stream(std::__addressof(__stream)) | |
| 975 | { } | |
| 976 | ||
| 977 | constexpr auto | |
| 978 | begin() | |
| 979 | { | |
| 980 | if (_M_stream != nullptr) | |
| 981 | *_M_stream >> _M_object; | |
| 982 | return _Iterator{*this}; | |
| 983 | } | |
| 984 | ||
| 985 | constexpr default_sentinel_t | |
| 986 | end() const noexcept | |
| 987 | { return default_sentinel; } | |
| 988 | ||
| 989 | private: | |
| 990 | basic_istream<_CharT, _Traits>* _M_stream = nullptr; | |
| 991 | _Val _M_object = _Val(); | |
| 992 | ||
| 993 | struct _Iterator | |
| 994 | { | |
| 995 | public: | |
| 996 | using iterator_category = input_iterator_tag; | |
| 997 | using difference_type = ptrdiff_t; | |
| 998 | using value_type = _Val; | |
| 999 | ||
| 1000 | _Iterator() = default; | |
| 1001 | ||
| 1002 | constexpr explicit | |
| 1003 | _Iterator(basic_istream_view& __parent) noexcept | |
| 1004 | : _M_parent(std::__addressof(__parent)) | |
| 1005 | { } | |
| 1006 | ||
| 1007 | _Iterator(const _Iterator&) = delete; | |
| 1008 | _Iterator(_Iterator&&) = default; | |
| 1009 | _Iterator& operator=(const _Iterator&) = delete; | |
| 1010 | _Iterator& operator=(_Iterator&&) = default; | |
| 1011 | ||
| 1012 | _Iterator& | |
| 1013 | operator++() | |
| 1014 | { | |
| 1015 | __glibcxx_assert(_M_parent->_M_stream != nullptr); | |
| 1016 | *_M_parent->_M_stream >> _M_parent->_M_object; | |
| 572992c8 | 1017 | return *this; |
| b7903d9f PP |
1018 | } |
| 1019 | ||
| 1020 | void | |
| 1021 | operator++(int) | |
| 1022 | { ++*this; } | |
| 1023 | ||
| 1024 | _Val& | |
| 1025 | operator*() const | |
| 1026 | { | |
| 1027 | __glibcxx_assert(_M_parent->_M_stream != nullptr); | |
| 1028 | return _M_parent->_M_object; | |
| 1029 | } | |
| 1030 | ||
| 1031 | friend bool | |
| 1032 | operator==(const _Iterator& __x, default_sentinel_t) | |
| 1033 | { return __x._M_at_end(); } | |
| 1034 | ||
| 1035 | private: | |
| 1036 | basic_istream_view* _M_parent = nullptr; | |
| 1037 | ||
| 1038 | bool | |
| 1039 | _M_at_end() const | |
| 1040 | { return _M_parent == nullptr || !*_M_parent->_M_stream; } | |
| 1041 | }; | |
| 1042 | ||
| 1043 | friend _Iterator; | |
| 1044 | }; | |
| 1045 | ||
| 1046 | template<typename _Val, typename _CharT, typename _Traits> | |
| 1047 | basic_istream_view<_Val, _CharT, _Traits> | |
| 1048 | istream_view(basic_istream<_CharT, _Traits>& __s) | |
| 1049 | { return basic_istream_view<_Val, _CharT, _Traits>{__s}; } | |
| 1050 | ||
| cba9ef06 PP |
1051 | namespace __detail |
| 1052 | { | |
| 1053 | struct _Empty { }; | |
| 1054 | } // namespace __detail | |
| 1055 | ||
| 1056 | namespace views | |
| 1057 | { | |
| 1058 | namespace __adaptor | |
| 1059 | { | |
| 1060 | template<typename _Callable> | |
| 1061 | struct _RangeAdaptorClosure; | |
| 1062 | ||
| 1063 | template<typename _Callable> | |
| 1064 | struct _RangeAdaptor | |
| 1065 | { | |
| 1066 | protected: | |
| 1067 | [[no_unique_address]] | |
| 1068 | conditional_t<!is_default_constructible_v<_Callable>, | |
| 1069 | _Callable, __detail::_Empty> _M_callable; | |
| 1070 | ||
| 1071 | public: | |
| 1072 | constexpr | |
| 1073 | _RangeAdaptor(const _Callable& = {}) | |
| 1074 | requires is_default_constructible_v<_Callable> | |
| 1075 | { } | |
| 1076 | ||
| 1077 | constexpr | |
| 1078 | _RangeAdaptor(_Callable __callable) | |
| 1079 | requires (!is_default_constructible_v<_Callable>) | |
| 1080 | : _M_callable(std::move(__callable)) | |
| 1081 | { } | |
| 1082 | ||
| 1083 | template<typename... _Args> | |
| 1084 | requires (sizeof...(_Args) >= 1) | |
| 1085 | constexpr auto | |
| 1086 | operator()(_Args&&... __args) const | |
| 1087 | { | |
| 1088 | if constexpr (is_invocable_v<_Callable, _Args...>) | |
| 1089 | { | |
| 1090 | static_assert(sizeof...(_Args) != 1, | |
| 1091 | "a _RangeAdaptor that accepts only one argument " | |
| 1092 | "should be defined as a _RangeAdaptorClosure"); | |
| 1093 | return _Callable{}(std::forward<_Args>(__args)...); | |
| 1094 | } | |
| 1095 | else | |
| 1096 | { | |
| 1097 | auto __closure = [__args...] <typename _Range> (_Range&& __r) { | |
| 1098 | return _Callable{}(std::forward<_Range>(__r), __args...); | |
| 1099 | }; | |
| 1100 | using _ClosureType = decltype(__closure); | |
| 1101 | return _RangeAdaptorClosure<_ClosureType>(std::move(__closure)); | |
| 1102 | } | |
| 1103 | } | |
| 1104 | }; | |
| 1105 | ||
| 1106 | template<typename _Callable> | |
| 1107 | struct _RangeAdaptorClosure : public _RangeAdaptor<_Callable> | |
| 1108 | { | |
| 1109 | using _RangeAdaptor<_Callable>::_RangeAdaptor; | |
| 1110 | ||
| 1111 | template<viewable_range _Range> | |
| 1112 | requires requires { declval<_Callable>()(declval<_Range>()); } | |
| 1113 | constexpr auto | |
| 1114 | operator()(_Range&& __r) const | |
| 1115 | { | |
| 1116 | if constexpr (is_default_constructible_v<_Callable>) | |
| 1117 | return _Callable{}(std::forward<_Range>(__r)); | |
| 1118 | else | |
| 1119 | return this->_M_callable(std::forward<_Range>(__r)); | |
| 1120 | } | |
| 1121 | ||
| 1122 | template<viewable_range _Range> | |
| 1123 | requires requires { declval<_Callable>()(declval<_Range>()); } | |
| 1124 | friend constexpr auto | |
| 1125 | operator|(_Range&& __r, const _RangeAdaptorClosure& __o) | |
| 1126 | { return __o(std::forward<_Range>(__r)); } | |
| 37f33df7 | 1127 | |
| cba9ef06 PP |
1128 | template<typename _Tp> |
| 1129 | friend constexpr auto | |
| 1130 | operator|(const _RangeAdaptorClosure<_Tp>& __x, | |
| 1131 | const _RangeAdaptorClosure& __y) | |
| 1132 | { | |
| 1133 | if constexpr (is_default_constructible_v<_Tp> | |
| 1134 | && is_default_constructible_v<_Callable>) | |
| 1135 | { | |
| 1136 | auto __closure = [] <typename _Up> (_Up&& __e) { | |
| 1137 | return std::forward<_Up>(__e) | decltype(__x){} | decltype(__y){}; | |
| 1138 | }; | |
| 1139 | return _RangeAdaptorClosure<decltype(__closure)>(__closure); | |
| 1140 | } | |
| 1141 | else if constexpr (is_default_constructible_v<_Tp> | |
| 1142 | && !is_default_constructible_v<_Callable>) | |
| 1143 | { | |
| 1144 | auto __closure = [__y] <typename _Up> (_Up&& __e) { | |
| 1145 | return std::forward<_Up>(__e) | decltype(__x){} | __y; | |
| 1146 | }; | |
| 1147 | return _RangeAdaptorClosure<decltype(__closure)>(__closure); | |
| 1148 | } | |
| 1149 | else if constexpr (!is_default_constructible_v<_Tp> | |
| 1150 | && is_default_constructible_v<_Callable>) | |
| 1151 | { | |
| 1152 | auto __closure = [__x] <typename _Up> (_Up&& __e) { | |
| 1153 | return std::forward<_Up>(__e) | __x | decltype(__y){}; | |
| 1154 | }; | |
| 1155 | return _RangeAdaptorClosure<decltype(__closure)>(__closure); | |
| 1156 | } | |
| 1157 | else | |
| 1158 | { | |
| 1159 | auto __closure = [__x, __y] <typename _Up> (_Up&& __e) { | |
| 1160 | return std::forward<_Up>(__e) | __x | __y; | |
| 1161 | }; | |
| 1162 | return _RangeAdaptorClosure<decltype(__closure)>(__closure); | |
| 1163 | } | |
| 1164 | } | |
| 1165 | }; | |
| 1166 | ||
| 1167 | template<typename _Callable> | |
| 1168 | _RangeAdaptorClosure(_Callable) -> _RangeAdaptorClosure<_Callable>; | |
| 1169 | } // namespace __adaptor | |
| 37f33df7 | 1170 | } // namespace views |
| cba9ef06 PP |
1171 | |
| 1172 | template<range _Range> requires is_object_v<_Range> | |
| 1173 | class ref_view : public view_interface<ref_view<_Range>> | |
| 1174 | { | |
| 1175 | private: | |
| 1176 | _Range* _M_r = nullptr; | |
| 1177 | ||
| 1178 | static void _S_fun(_Range&); // not defined | |
| 1179 | static void _S_fun(_Range&&) = delete; | |
| 1180 | ||
| 1181 | public: | |
| 1182 | constexpr | |
| 1183 | ref_view() noexcept = default; | |
| 1184 | ||
| 1185 | template<__detail::__not_same_as<ref_view> _Tp> | |
| 1186 | requires convertible_to<_Tp, _Range&> | |
| 1187 | && requires { _S_fun(declval<_Tp>()); } | |
| 1188 | constexpr | |
| 1189 | ref_view(_Tp&& __t) | |
| 1190 | : _M_r(std::__addressof(static_cast<_Range&>(std::forward<_Tp>(__t)))) | |
| 1191 | { } | |
| 1192 | ||
| 1193 | constexpr _Range& | |
| 1194 | base() const | |
| 1195 | { return *_M_r; } | |
| 1196 | ||
| 1197 | constexpr iterator_t<_Range> | |
| 1198 | begin() const | |
| 1199 | { return ranges::begin(*_M_r); } | |
| 1200 | ||
| 1201 | constexpr sentinel_t<_Range> | |
| 1202 | end() const | |
| 1203 | { return ranges::end(*_M_r); } | |
| 1204 | ||
| 1205 | constexpr bool | |
| 1206 | empty() const requires requires { ranges::empty(*_M_r); } | |
| 1207 | { return ranges::empty(*_M_r); } | |
| 1208 | ||
| 1209 | constexpr auto | |
| 1210 | size() const requires sized_range<_Range> | |
| 1211 | { return ranges::size(*_M_r); } | |
| 1212 | ||
| 1213 | constexpr auto | |
| 1214 | data() const requires contiguous_range<_Range> | |
| 1215 | { return ranges::data(*_M_r); } | |
| 1216 | }; | |
| 1217 | ||
| 1218 | template<typename _Range> | |
| 1219 | ref_view(_Range&) -> ref_view<_Range>; | |
| 1220 | ||
| 1221 | template<typename _Tp> | |
| 1222 | inline constexpr bool enable_safe_range<ref_view<_Tp>> = true; | |
| 1223 | ||
| 1224 | namespace views | |
| 1225 | { | |
| 1226 | inline constexpr __adaptor::_RangeAdaptorClosure all | |
| 1227 | = [] <viewable_range _Range> (_Range&& __r) | |
| 1228 | { | |
| 1229 | if constexpr (view<decay_t<_Range>>) | |
| 1230 | return std::forward<_Range>(__r); | |
| 1231 | else if constexpr (requires { ref_view{std::forward<_Range>(__r)}; }) | |
| 1232 | return ref_view{std::forward<_Range>(__r)}; | |
| 1233 | else | |
| 1234 | return subrange{std::forward<_Range>(__r)}; | |
| 1235 | }; | |
| 1236 | } // namespace views | |
| 1237 | ||
| 1238 | template<viewable_range _Range> | |
| 1239 | using all_view = decltype(views::all(declval<_Range>())); | |
| 1240 | ||
| 1241 | // XXX: the following algos are copied from ranges_algo.h to avoid a circular | |
| 1242 | // dependency with that header. | |
| 1243 | namespace __detail | |
| 1244 | { | |
| 1245 | template<input_iterator _Iter, sentinel_for<_Iter> _Sent, | |
| 1246 | typename _Proj = identity, | |
| 1247 | indirect_unary_predicate<projected<_Iter, _Proj>> _Pred> | |
| 1248 | constexpr _Iter | |
| 1249 | find_if(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) | |
| 1250 | { | |
| 1251 | while (__first != __last | |
| 1252 | && !(bool)std::__invoke(__pred, std::__invoke(__proj, *__first))) | |
| 1253 | ++__first; | |
| 1254 | return __first; | |
| 1255 | } | |
| 1256 | ||
| 1257 | template<input_iterator _Iter, sentinel_for<_Iter> _Sent, | |
| 1258 | typename _Proj = identity, | |
| 1259 | indirect_unary_predicate<projected<_Iter, _Proj>> _Pred> | |
| 1260 | constexpr _Iter | |
| 1261 | find_if_not(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) | |
| 1262 | { | |
| 1263 | while (__first != __last | |
| 1264 | && (bool)std::__invoke(__pred, std::__invoke(__proj, *__first))) | |
| 1265 | ++__first; | |
| 1266 | return __first; | |
| 1267 | } | |
| 1268 | ||
| 1269 | template<typename _Tp, typename _Proj = identity, | |
| 1270 | indirect_strict_weak_order<projected<const _Tp*, _Proj>> | |
| 1271 | _Comp = ranges::less> | |
| 1272 | constexpr const _Tp& | |
| 1273 | min(const _Tp& __a, const _Tp& __b, _Comp __comp = {}, _Proj __proj = {}) | |
| 1274 | { | |
| 1275 | if (std::__invoke(std::move(__comp), | |
| 1276 | std::__invoke(__proj, __b), | |
| 1277 | std::__invoke(__proj, __a))) | |
| 1278 | return __b; | |
| 1279 | else | |
| 1280 | return __a; | |
| 1281 | } | |
| 1282 | ||
| 1283 | template<input_iterator _Iter1, sentinel_for<_Iter1> _Sent1, | |
| 1284 | input_iterator _Iter2, sentinel_for<_Iter2> _Sent2, | |
| 1285 | typename _Pred = ranges::equal_to, | |
| 1286 | typename _Proj1 = identity, typename _Proj2 = identity> | |
| 1287 | requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2> | |
| 1288 | constexpr pair<_Iter1, _Iter2> | |
| 1289 | mismatch(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2, | |
| 1290 | _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) | |
| 1291 | { | |
| 1292 | while (__first1 != __last1 && __first2 != __last2 | |
| 1293 | && (bool)std::__invoke(__pred, | |
| 1294 | std::__invoke(__proj1, *__first1), | |
| 1295 | std::__invoke(__proj2, *__first2))) | |
| 1296 | { | |
| 1297 | ++__first1; | |
| 1298 | ++__first2; | |
| 1299 | } | |
| 1300 | return { std::move(__first1), std::move(__first2) }; | |
| 1301 | } | |
| 1302 | } // namespace __detail | |
| 1303 | ||
| 1304 | template<input_range _Vp, | |
| 1305 | indirect_unary_predicate<iterator_t<_Vp>> _Pred> | |
| 1306 | requires view<_Vp> && is_object_v<_Pred> | |
| 1307 | class filter_view : public view_interface<filter_view<_Vp, _Pred>> | |
| 1308 | { | |
| 1309 | private: | |
| 1310 | struct _Sentinel; | |
| 1311 | ||
| 1312 | struct _Iterator | |
| 1313 | { | |
| 1314 | private: | |
| 1315 | static constexpr auto | |
| 1316 | _S_iter_concept() | |
| 1317 | { | |
| 1318 | if constexpr (bidirectional_range<_Vp>) | |
| 1319 | return bidirectional_iterator_tag{}; | |
| 1320 | else if constexpr (forward_range<_Vp>) | |
| 1321 | return forward_iterator_tag{}; | |
| 1322 | else | |
| 1323 | return input_iterator_tag{}; | |
| 1324 | } | |
| 1325 | ||
| 1326 | static constexpr auto | |
| 1327 | _S_iter_cat() | |
| 1328 | { | |
| 1329 | using _Cat = iterator_traits<iterator_t<_Vp>>::iterator_category; | |
| 1330 | if constexpr (derived_from<_Cat, bidirectional_iterator_tag>) | |
| 1331 | return bidirectional_iterator_tag{}; | |
| 1332 | else if constexpr (derived_from<_Cat, forward_iterator_tag>) | |
| 1333 | return forward_iterator_tag{}; | |
| 1334 | else | |
| 1335 | return _Cat{}; | |
| 1336 | } | |
| 1337 | ||
| 1338 | friend filter_view; | |
| 1339 | ||
| 1340 | iterator_t<_Vp> _M_current = iterator_t<_Vp>(); | |
| 1341 | filter_view* _M_parent = nullptr; | |
| 1342 | ||
| 1343 | public: | |
| 1344 | using iterator_concept = decltype(_S_iter_concept()); | |
| 1345 | using iterator_category = decltype(_S_iter_cat()); | |
| 1346 | using value_type = range_value_t<_Vp>; | |
| 1347 | using difference_type = range_difference_t<_Vp>; | |
| 1348 | ||
| 1349 | _Iterator() = default; | |
| 1350 | ||
| 1351 | constexpr | |
| 1352 | _Iterator(filter_view& __parent, iterator_t<_Vp> __current) | |
| 1353 | : _M_current(std::move(__current)), | |
| 1354 | _M_parent(std::__addressof(__parent)) | |
| 1355 | { } | |
| 1356 | ||
| 1357 | constexpr iterator_t<_Vp> | |
| 1358 | base() const & | |
| 1359 | requires copyable<iterator_t<_Vp>> | |
| 1360 | { return _M_current; } | |
| 1361 | ||
| 1362 | constexpr iterator_t<_Vp> | |
| 1363 | base() && | |
| 1364 | { return std::move(_M_current); } | |
| 1365 | ||
| 1366 | constexpr range_reference_t<_Vp> | |
| 1367 | operator*() const | |
| 1368 | { return *_M_current; } | |
| 1369 | ||
| 1370 | constexpr iterator_t<_Vp> | |
| 1371 | operator->() const | |
| 1372 | requires __detail::__has_arrow<iterator_t<_Vp>> | |
| 1373 | && copyable<iterator_t<_Vp>> | |
| 1374 | { return _M_current; } | |
| 1375 | ||
| 1376 | constexpr _Iterator& | |
| 1377 | operator++() | |
| 1378 | { | |
| 1379 | _M_current = __detail::find_if(std::move(++_M_current), | |
| 1380 | ranges::end(_M_parent->_M_base), | |
| 1381 | std::ref(*_M_parent->_M_pred)); | |
| 1382 | return *this; | |
| 1383 | } | |
| 1384 | ||
| 1385 | constexpr void | |
| 1386 | operator++(int) | |
| 1387 | { ++*this; } | |
| 1388 | ||
| 1389 | constexpr _Iterator | |
| 1390 | operator++(int) requires forward_range<_Vp> | |
| 1391 | { | |
| 1392 | auto __tmp = *this; | |
| 1393 | ++*this; | |
| 1394 | return __tmp; | |
| 1395 | } | |
| 1396 | ||
| 1397 | constexpr _Iterator& | |
| 1398 | operator--() requires bidirectional_range<_Vp> | |
| 1399 | { | |
| 1400 | do | |
| 1401 | --_M_current; | |
| 1402 | while (!std::__invoke(*_M_parent->_M_pred, *_M_current)); | |
| 1403 | return *this; | |
| 1404 | } | |
| 1405 | ||
| 1406 | constexpr _Iterator | |
| 1407 | operator--(int) requires bidirectional_range<_Vp> | |
| 1408 | { | |
| 1409 | auto __tmp = *this; | |
| 1410 | --*this; | |
| 1411 | return __tmp; | |
| 1412 | } | |
| 1413 | ||
| 1414 | friend constexpr bool | |
| 1415 | operator==(const _Iterator& __x, const _Iterator& __y) | |
| 1416 | requires equality_comparable<iterator_t<_Vp>> | |
| 1417 | { return __x._M_current == __y._M_current; } | |
| 1418 | ||
| 1419 | friend constexpr range_rvalue_reference_t<_Vp> | |
| 1420 | iter_move(const _Iterator& __i) | |
| 1421 | noexcept(noexcept(ranges::iter_move(__i._M_current))) | |
| 1422 | { return ranges::iter_move(__i._M_current); } | |
| 1423 | ||
| 1424 | friend constexpr void | |
| 1425 | iter_swap(const _Iterator& __x, const _Iterator& __y) | |
| 1426 | noexcept(noexcept(ranges::iter_swap(__x._M_current, __y._M_current))) | |
| 1427 | requires indirectly_swappable<iterator_t<_Vp>> | |
| 1428 | { ranges::iter_swap(__x._M_current, __y._M_current); } | |
| 1429 | }; | |
| 1430 | ||
| 1431 | struct _Sentinel | |
| 1432 | { | |
| 1433 | private: | |
| 1434 | sentinel_t<_Vp> _M_end = sentinel_t<_Vp>(); | |
| 1435 | ||
| 1436 | constexpr bool | |
| 1437 | __equal(const _Iterator& __i) const | |
| 1438 | { return __i._M_current == _M_end; } | |
| 1439 | ||
| 1440 | public: | |
| 1441 | _Sentinel() = default; | |
| 1442 | ||
| 1443 | constexpr explicit | |
| 1444 | _Sentinel(filter_view& __parent) | |
| 1445 | : _M_end(ranges::end(__parent._M_base)) | |
| 1446 | { } | |
| 1447 | ||
| 1448 | constexpr sentinel_t<_Vp> | |
| 1449 | base() const | |
| 1450 | { return _M_end; } | |
| 1451 | ||
| 1452 | friend constexpr bool | |
| 1453 | operator==(const _Iterator& __x, const _Sentinel& __y) | |
| 1454 | { return __y.__equal(__x); } | |
| 1455 | }; | |
| 1456 | ||
| 1457 | _Vp _M_base = _Vp(); | |
| 1458 | __detail::__box<_Pred> _M_pred; | |
| 1459 | ||
| 1460 | public: | |
| 1461 | filter_view() = default; | |
| 1462 | ||
| 1463 | constexpr | |
| 1464 | filter_view(_Vp __base, _Pred __pred) | |
| 1465 | : _M_base(std::move(__base)), _M_pred(std::move(__pred)) | |
| 1466 | { } | |
| 1467 | ||
| 1468 | /* XXX: P3280 removes this constructor | |
| 1469 | template<input_range _Range> | |
| 1470 | requires viewable_range<_Range> | |
| 1471 | && constructible_from<_Vp, all_view<_Range>> | |
| 1472 | constexpr | |
| 1473 | filter_view(_Range&& __r, _Pred __pred) | |
| 1474 | : _M_base(views::all(std::forward<_Range>(__r))), | |
| 1475 | _M_pred(std::move(__pred)) | |
| 1476 | { } | |
| 1477 | */ | |
| 1478 | ||
| 1479 | constexpr _Vp | |
| 1480 | base() const& requires copy_constructible<_Vp> | |
| 1481 | { return _M_base; } | |
| 1482 | ||
| 1483 | constexpr _Vp | |
| 1484 | base() && | |
| 1485 | { return std::move(_M_base); } | |
| 1486 | ||
| 1487 | constexpr _Iterator | |
| 1488 | begin() | |
| 1489 | { | |
| 1490 | // XXX: we need to cache the result here as per [range.filter.view] | |
| 1491 | __glibcxx_assert(_M_pred.has_value()); | |
| 1492 | return {*this, __detail::find_if(ranges::begin(_M_base), | |
| 1493 | ranges::end(_M_base), | |
| 1494 | std::ref(*_M_pred))}; | |
| 1495 | } | |
| 1496 | ||
| 1497 | constexpr auto | |
| 1498 | end() | |
| 1499 | { | |
| 1500 | if constexpr (common_range<_Vp>) | |
| 1501 | return _Iterator{*this, ranges::end(_M_base)}; | |
| 1502 | else | |
| 1503 | return _Sentinel{*this}; | |
| 1504 | } | |
| 1505 | }; | |
| 1506 | ||
| 1507 | template<typename _Range, typename _Pred> | |
| 1508 | filter_view(_Range&&, _Pred) -> filter_view<all_view<_Range>, _Pred>; | |
| 1509 | ||
| 1510 | namespace views | |
| 1511 | { | |
| 1512 | inline constexpr __adaptor::_RangeAdaptor filter | |
| 1513 | = [] <viewable_range _Range, typename _Pred> (_Range&& __r, _Pred&& __p) | |
| 1514 | { | |
| 1515 | return filter_view{std::forward<_Range>(__r), std::forward<_Pred>(__p)}; | |
| 1516 | }; | |
| 1517 | } // namespace views | |
| 1518 | ||
| 1519 | template<input_range _Vp, copy_constructible _Fp> | |
| 1520 | requires view<_Vp> && is_object_v<_Fp> | |
| 1521 | && regular_invocable<_Fp&, range_reference_t<_Vp>> | |
| 1522 | class transform_view : public view_interface<transform_view<_Vp, _Fp>> | |
| 1523 | { | |
| 1524 | private: | |
| 1525 | template<bool _Const> | |
| 1526 | struct _Sentinel; | |
| 1527 | ||
| 1528 | template<bool _Const> | |
| 1529 | struct _Iterator | |
| 1530 | { | |
| 1531 | private: | |
| 1532 | using _Parent | |
| 1533 | = conditional_t<_Const, const transform_view, transform_view>; | |
| 1534 | using _Base = conditional_t<_Const, const _Vp, _Vp>; | |
| 1535 | ||
| 1536 | static constexpr auto | |
| 1537 | _S_iter_concept() | |
| 1538 | { | |
| 1539 | if constexpr (random_access_range<_Vp>) | |
| 1540 | return random_access_iterator_tag{}; | |
| 1541 | else if constexpr (bidirectional_range<_Vp>) | |
| 1542 | return bidirectional_iterator_tag{}; | |
| 1543 | else if constexpr (forward_range<_Vp>) | |
| 1544 | return forward_iterator_tag{}; | |
| 1545 | else | |
| 1546 | return input_iterator_tag{}; | |
| 1547 | } | |
| 1548 | ||
| 1549 | static constexpr auto | |
| 1550 | _S_iter_cat() | |
| 1551 | { | |
| 1552 | using _Cat = iterator_traits<iterator_t<_Base>>::iterator_category; | |
| 1553 | if constexpr (derived_from<_Cat, contiguous_iterator_tag>) | |
| 1554 | return random_access_iterator_tag{}; | |
| 1555 | else | |
| 1556 | return _Cat{}; | |
| 1557 | } | |
| 1558 | ||
| 1559 | static constexpr decltype(auto) | |
| 1560 | __iter_move(const _Iterator& __i = {}) | |
| 1561 | noexcept(noexcept(std::__invoke(*__i._M_parent->_M_fun, | |
| 1562 | *__i._M_current))) | |
| 1563 | { | |
| 1564 | if constexpr (is_lvalue_reference_v<decltype(*__i)>) | |
| 1565 | return std::move(*__i); | |
| 1566 | else | |
| 1567 | return *__i; | |
| 1568 | } | |
| 1569 | ||
| 1570 | iterator_t<_Base> _M_current = iterator_t<_Base>(); | |
| 1571 | _Parent* _M_parent = nullptr; | |
| 1572 | ||
| 1573 | public: | |
| 1574 | using iterator_concept = decltype(_S_iter_concept()); | |
| 1575 | using iterator_category = decltype(_S_iter_cat()); | |
| 1576 | using value_type | |
| 1577 | = remove_cvref_t<invoke_result_t<_Fp&, range_reference_t<_Base>>>; | |
| 1578 | using difference_type = range_difference_t<_Base>; | |
| 1579 | ||
| 1580 | _Iterator() = default; | |
| 1581 | ||
| 1582 | constexpr | |
| 1583 | _Iterator(_Parent& __parent, iterator_t<_Base> __current) | |
| 1584 | : _M_current(std::move(__current)), | |
| 1585 | _M_parent(std::__addressof(__parent)) | |
| 1586 | { } | |
| 1587 | ||
| 1588 | constexpr | |
| 1589 | _Iterator(_Iterator<!_Const> __i) | |
| 1590 | requires _Const | |
| 1591 | && convertible_to<iterator_t<_Vp>, iterator_t<_Base>> | |
| 1592 | : _M_current(std::move(__i._M_current)), _M_parent(__i._M_parent) | |
| 1593 | { } | |
| 1594 | ||
| 1595 | constexpr iterator_t<_Base> | |
| 1596 | base() const & | |
| 1597 | requires copyable<iterator_t<_Base>> | |
| 1598 | { return _M_current; } | |
| 1599 | ||
| 1600 | constexpr iterator_t<_Base> | |
| 1601 | base() && | |
| 1602 | { return std::move(_M_current); } | |
| 1603 | ||
| 1604 | constexpr decltype(auto) | |
| 1605 | operator*() const | |
| 1606 | { return std::__invoke(*_M_parent->_M_fun, *_M_current); } | |
| 1607 | ||
| 1608 | constexpr _Iterator& | |
| 1609 | operator++() | |
| 1610 | { | |
| 1611 | ++_M_current; | |
| 1612 | return *this; | |
| 1613 | } | |
| 1614 | ||
| 1615 | constexpr void | |
| 1616 | operator++(int) | |
| 1617 | { ++_M_current; } | |
| 1618 | ||
| 1619 | constexpr _Iterator | |
| 1620 | operator++(int) requires forward_range<_Base> | |
| 1621 | { | |
| 1622 | auto __tmp = *this; | |
| 1623 | ++*this; | |
| 1624 | return __tmp; | |
| 1625 | } | |
| 1626 | ||
| 1627 | constexpr _Iterator& | |
| 1628 | operator--() requires bidirectional_range<_Base> | |
| 1629 | { | |
| 1630 | --_M_current; | |
| 1631 | return *this; | |
| 1632 | } | |
| 1633 | ||
| 1634 | constexpr _Iterator | |
| 1635 | operator--(int) requires bidirectional_range<_Base> | |
| 1636 | { | |
| 1637 | auto __tmp = *this; | |
| 1638 | --*this; | |
| 1639 | return __tmp; | |
| 1640 | } | |
| 1641 | ||
| 1642 | constexpr _Iterator& | |
| 1643 | operator+=(difference_type __n) requires random_access_range<_Base> | |
| 1644 | { | |
| 1645 | _M_current += __n; | |
| 1646 | return *this; | |
| 1647 | } | |
| 1648 | ||
| 1649 | constexpr _Iterator& | |
| 1650 | operator-=(difference_type __n) requires random_access_range<_Base> | |
| 1651 | { | |
| 1652 | _M_current -= __n; | |
| 1653 | return *this; | |
| 1654 | } | |
| 1655 | ||
| 1656 | constexpr decltype(auto) | |
| 1657 | operator[](difference_type __n) const | |
| 1658 | requires random_access_range<_Base> | |
| 1659 | { return std::__invoke(*_M_parent->_M_fun, _M_current[__n]); } | |
| 1660 | ||
| 1661 | friend constexpr bool | |
| 1662 | operator==(const _Iterator& __x, const _Iterator& __y) | |
| 1663 | requires equality_comparable<iterator_t<_Base>> | |
| 1664 | { return __x._M_current == __y._M_current; } | |
| 1665 | ||
| 1666 | friend constexpr bool | |
| 1667 | operator<(const _Iterator& __x, const _Iterator& __y) | |
| 1668 | requires random_access_range<_Base> | |
| 1669 | { return __x._M_current < __y._M_current; } | |
| 1670 | ||
| 1671 | friend constexpr bool | |
| 1672 | operator>(const _Iterator& __x, const _Iterator& __y) | |
| 1673 | requires random_access_range<_Base> | |
| 1674 | { return __y < __x; } | |
| 1675 | ||
| 1676 | friend constexpr bool | |
| 1677 | operator<=(const _Iterator& __x, const _Iterator& __y) | |
| 1678 | requires random_access_range<_Base> | |
| 1679 | { return !(__y < __x); } | |
| 1680 | ||
| 1681 | friend constexpr bool | |
| 1682 | operator>=(const _Iterator& __x, const _Iterator& __y) | |
| 1683 | requires random_access_range<_Base> | |
| 1684 | { return !(__x < __y); } | |
| 1685 | ||
| 1686 | #ifdef __cpp_lib_three_way_comparison | |
| 1687 | friend constexpr auto | |
| 1688 | operator<=>(const _Iterator& __x, const _Iterator& __y) | |
| 1689 | requires random_access_range<_Base> | |
| 1690 | && three_way_comparable<iterator_t<_Base>> | |
| 1691 | { return __x._M_current <=> __y._M_current; } | |
| 1692 | #endif | |
| 1693 | ||
| 1694 | friend constexpr _Iterator | |
| 1695 | operator+(_Iterator __i, difference_type __n) | |
| 1696 | requires random_access_range<_Base> | |
| 1697 | { return {*__i._M_parent, __i._M_current + __n}; } | |
| 1698 | ||
| 1699 | friend constexpr _Iterator | |
| 1700 | operator+(difference_type __n, _Iterator __i) | |
| 1701 | requires random_access_range<_Base> | |
| 1702 | { return {*__i._M_parent, __i._M_current + __n}; } | |
| 1703 | ||
| 1704 | friend constexpr _Iterator | |
| 1705 | operator-(_Iterator __i, difference_type __n) | |
| 1706 | requires random_access_range<_Base> | |
| 1707 | { return {*__i._M_parent, __i._M_current - __n}; } | |
| 1708 | ||
| 1709 | friend constexpr difference_type | |
| 1710 | operator-(const _Iterator& __x, const _Iterator& __y) | |
| 1711 | requires random_access_range<_Base> | |
| 1712 | { return __x._M_current - __y._M_current; } | |
| 1713 | ||
| 1714 | friend constexpr decltype(auto) | |
| 1715 | iter_move(const _Iterator& __i) noexcept(noexcept(__iter_move())) | |
| 1716 | { return __iter_move(__i); } | |
| 1717 | ||
| 1718 | friend constexpr void | |
| 1719 | iter_swap(const _Iterator& __x, const _Iterator& __y) | |
| 1720 | noexcept(noexcept(ranges::iter_swap(__x._M_current, __y._M_current))) | |
| 1721 | requires indirectly_swappable<iterator_t<_Base>> | |
| 1722 | { return ranges::iter_swap(__x._M_current, __y._M_current); } | |
| 1723 | ||
| 1724 | friend _Sentinel<_Const>; | |
| 1725 | }; | |
| 1726 | ||
| 1727 | template<bool _Const> | |
| 1728 | struct _Sentinel | |
| 1729 | { | |
| 1730 | private: | |
| 1731 | using _Parent | |
| 1732 | = conditional_t<_Const, const transform_view, transform_view>; | |
| 1733 | using _Base = conditional_t<_Const, const _Vp, _Vp>; | |
| 1734 | ||
| 1735 | constexpr range_difference_t<_Base> | |
| 1736 | __distance_from(const _Iterator<_Const>& __i) const | |
| 1737 | { return _M_end - __i._M_current; } | |
| 1738 | ||
| 1739 | constexpr bool | |
| 1740 | __equal(const _Iterator<_Const>& __i) const | |
| 1741 | { return __i._M_current == _M_end; } | |
| 1742 | ||
| 1743 | sentinel_t<_Base> _M_end = sentinel_t<_Base>(); | |
| 1744 | ||
| 1745 | public: | |
| 1746 | _Sentinel() = default; | |
| 1747 | ||
| 1748 | constexpr explicit | |
| 1749 | _Sentinel(sentinel_t<_Base> __end) | |
| 1750 | : _M_end(__end) | |
| 1751 | { } | |
| 1752 | ||
| 1753 | constexpr | |
| 1754 | _Sentinel(_Sentinel<!_Const> __i) | |
| 1755 | requires _Const | |
| 1756 | && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>> | |
| 1757 | : _M_end(std::move(__i._M_end)) | |
| 1758 | { } | |
| 1759 | ||
| 1760 | constexpr sentinel_t<_Base> | |
| 1761 | base() const | |
| 1762 | { return _M_end; } | |
| 1763 | ||
| 1764 | friend constexpr bool | |
| 1765 | operator==(const _Iterator<_Const>& __x, const _Sentinel& __y) | |
| 1766 | { return __y.__equal(__x); } | |
| 1767 | ||
| 1768 | friend constexpr range_difference_t<_Base> | |
| 1769 | operator-(const _Iterator<_Const>& __x, const _Sentinel& __y) | |
| 1770 | requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base>> | |
| 1771 | { return -__y.__distance_from(__x); } | |
| 1772 | ||
| 1773 | friend constexpr range_difference_t<_Base> | |
| 1774 | operator-(const _Sentinel& __y, const _Iterator<_Const>& __x) | |
| 1775 | requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base>> | |
| 1776 | { return __y.__distance_from(__x); } | |
| 1777 | }; | |
| 1778 | ||
| 1779 | _Vp _M_base = _Vp(); | |
| 1780 | __detail::__box<_Fp> _M_fun; | |
| 1781 | ||
| 1782 | public: | |
| 1783 | transform_view() = default; | |
| 1784 | ||
| 1785 | constexpr | |
| 1786 | transform_view(_Vp __base, _Fp __fun) | |
| 1787 | : _M_base(std::move(__base)), _M_fun(std::move(__fun)) | |
| 1788 | { } | |
| 1789 | ||
| 1790 | /* XXX: P3280 removes this constructor | |
| 1791 | template<input_range _Range> | |
| 1792 | requires viewable_range<_Range> | |
| 1793 | && constructible_from<_Vp, all_view<_Range>> | |
| 1794 | constexpr | |
| 1795 | transform_view(_Range&& __r, _Fp __fun) | |
| 1796 | : _M_base(views::all(std::forward<_Range>(__r))) | |
| 1797 | { | |
| 1798 | } | |
| 1799 | */ | |
| 1800 | ||
| 1801 | constexpr _Vp | |
| 1802 | base() const& requires copy_constructible<_Vp> | |
| 1803 | { return _M_base ; } | |
| 1804 | ||
| 1805 | constexpr _Vp | |
| 1806 | base() && | |
| 1807 | { return std::move(_M_base); } | |
| 1808 | ||
| 1809 | constexpr _Iterator<false> | |
| 1810 | begin() | |
| 1811 | { return _Iterator<false>{*this, ranges::begin(_M_base)}; } | |
| 1812 | ||
| 1813 | constexpr _Iterator<true> | |
| 1814 | begin() const | |
| 1815 | requires range<const _Vp> | |
| 1816 | && regular_invocable<const _Fp&, range_reference_t<const _Vp>> | |
| 1817 | { return _Iterator<true>{*this, ranges::begin(_M_base)}; } | |
| 1818 | ||
| 1819 | constexpr _Sentinel<false> | |
| 1820 | end() | |
| 1821 | { return _Sentinel<false>{ranges::end(_M_base)}; } | |
| 1822 | ||
| 1823 | constexpr _Iterator<false> | |
| 1824 | end() requires common_range<_Vp> | |
| 1825 | { return _Iterator<false>{*this, ranges::end(_M_base)}; } | |
| 1826 | ||
| 1827 | constexpr _Sentinel<true> | |
| 1828 | end() const | |
| 1829 | requires range<const _Vp> | |
| 1830 | && regular_invocable<const _Fp&, range_reference_t<const _Vp>> | |
| 1831 | { return _Sentinel<true>{ranges::end(_M_base)}; } | |
| 1832 | ||
| 1833 | constexpr _Iterator<true> | |
| 1834 | end() const | |
| 1835 | requires common_range<const _Vp> | |
| 1836 | && regular_invocable<const _Fp&, range_reference_t<const _Vp>> | |
| 1837 | { return _Iterator<true>{*this, ranges::end(_M_base)}; } | |
| 1838 | ||
| 1839 | constexpr auto | |
| 1840 | size() requires sized_range<_Vp> | |
| 1841 | { return ranges::size(_M_base); } | |
| 1842 | ||
| 1843 | constexpr auto | |
| 1844 | size() const requires sized_range<const _Vp> | |
| 1845 | { return ranges::size(_M_base); } | |
| 1846 | }; | |
| 1847 | ||
| 1848 | template<typename _Range, typename _Fp> | |
| 1849 | transform_view(_Range&&, _Fp) -> transform_view<all_view<_Range>, _Fp>; | |
| 1850 | ||
| 1851 | namespace views | |
| 1852 | { | |
| 1853 | inline constexpr __adaptor::_RangeAdaptor transform | |
| 1854 | = [] <viewable_range _Range, typename _Fp> (_Range&& __r, _Fp&& __f) | |
| 1855 | { | |
| 1856 | return transform_view{std::forward<_Range>(__r), std::forward<_Fp>(__f)}; | |
| 1857 | }; | |
| 1858 | } // namespace views | |
| 1859 | ||
| 1860 | template<view _Vp> | |
| 1861 | class take_view : public view_interface<take_view<_Vp>> | |
| 1862 | { | |
| 1863 | private: | |
| 1864 | template<bool _Const> | |
| 1865 | struct _Sentinel | |
| 1866 | { | |
| 1867 | private: | |
| 1868 | using _Base = conditional_t<_Const, const _Vp, _Vp>; | |
| 1869 | using _CI = counted_iterator<iterator_t<_Base>>; | |
| 1870 | ||
| 1871 | sentinel_t<_Base> _M_end = sentinel_t<_Base>(); | |
| 1872 | ||
| 1873 | public: | |
| 1874 | _Sentinel() = default; | |
| 1875 | ||
| 1876 | constexpr explicit | |
| 1877 | _Sentinel(sentinel_t<_Base> __end) | |
| 1878 | : _M_end(__end) | |
| 1879 | { } | |
| 1880 | ||
| 1881 | constexpr | |
| 1882 | _Sentinel(_Sentinel<!_Const> __s) | |
| 1883 | requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>> | |
| 1884 | : _M_end(std::move(__s._M_end)) | |
| 1885 | { } | |
| 1886 | ||
| 1887 | constexpr sentinel_t<_Base> | |
| 1888 | base() const | |
| 1889 | { return _M_end; } | |
| 1890 | ||
| 1891 | friend constexpr bool operator==(const _CI& __y, const _Sentinel& __x) | |
| 1892 | { return __y.count() == 0 || __y.base() == __x._M_end; } | |
| 1893 | }; | |
| 1894 | ||
| 1895 | _Vp _M_base = _Vp(); | |
| 1896 | range_difference_t<_Vp> _M_count = 0; | |
| 1897 | ||
| 1898 | public: | |
| 1899 | take_view() = default; | |
| 1900 | ||
| 1901 | constexpr | |
| 1902 | take_view(_Vp base, range_difference_t<_Vp> __count) | |
| 1903 | : _M_base(std::move(base)), _M_count(std::move(__count)) | |
| 1904 | { } | |
| 1905 | ||
| 1906 | /* XXX: P3280 removes this constructor | |
| 1907 | template<viewable_range _Range> | |
| 1908 | requires constructible_from<_Vp, all_view<_Range>> | |
| 1909 | constexpr | |
| 1910 | take_view(_Range&& __r, range_difference_t<_Vp> __count) | |
| 1911 | : _M_base(views::all(std::forward<_Range>(__r))), _M_count(__count) | |
| 1912 | { } | |
| 1913 | */ | |
| 1914 | ||
| 1915 | constexpr _Vp | |
| 1916 | base() const& requires copy_constructible<_Vp> | |
| 1917 | { return _M_base; } | |
| 1918 | ||
| 1919 | constexpr _Vp | |
| 1920 | base() && | |
| 1921 | { return std::move(_M_base); } | |
| 1922 | ||
| 1923 | constexpr auto | |
| 1924 | begin() requires (!__detail::__simple_view<_Vp>) | |
| 1925 | { | |
| 1926 | if constexpr (sized_range<_Vp>) | |
| 1927 | { | |
| 1928 | if constexpr (random_access_range<_Vp>) | |
| 1929 | return ranges::begin(_M_base); | |
| 1930 | else | |
| 1931 | return counted_iterator{ranges::begin(_M_base), size()}; | |
| 1932 | } | |
| 1933 | else | |
| 1934 | return counted_iterator{ranges::begin(_M_base), _M_count}; | |
| 1935 | } | |
| 1936 | ||
| 1937 | constexpr auto | |
| 1938 | begin() const requires range<const _Vp> | |
| 1939 | { | |
| 1940 | if constexpr (sized_range<const _Vp>) | |
| 1941 | { | |
| 1942 | if constexpr (random_access_range<const _Vp>) | |
| 1943 | return ranges::begin(_M_base); | |
| 1944 | else | |
| 1945 | return counted_iterator{ranges::begin(_M_base), size()}; | |
| 1946 | } | |
| 1947 | else | |
| 1948 | return counted_iterator{ranges::begin(_M_base), _M_count}; | |
| 1949 | } | |
| 1950 | ||
| 1951 | constexpr auto | |
| 1952 | end() requires (!__detail::__simple_view<_Vp>) | |
| 1953 | { | |
| 1954 | if constexpr (sized_range<_Vp>) | |
| 1955 | { | |
| 1956 | if constexpr (random_access_range<_Vp>) | |
| 1957 | return ranges::begin(_M_base) + size(); | |
| 1958 | else | |
| 1959 | return default_sentinel; | |
| 1960 | } | |
| 1961 | else | |
| 1962 | return _Sentinel<false>{ranges::end(_M_base)}; | |
| 1963 | } | |
| 1964 | ||
| 1965 | constexpr auto | |
| 1966 | end() const requires range<const _Vp> | |
| 1967 | { | |
| 1968 | if constexpr (sized_range<const _Vp>) | |
| 1969 | { | |
| 1970 | if constexpr (random_access_range<const _Vp>) | |
| 1971 | return ranges::begin(_M_base) + size(); | |
| 1972 | else | |
| 1973 | return default_sentinel; | |
| 1974 | } | |
| 1975 | else | |
| 1976 | return _Sentinel<true>{ranges::end(_M_base)}; | |
| 1977 | } | |
| 1978 | ||
| 1979 | constexpr auto | |
| 1980 | size() requires sized_range<_Vp> | |
| 1981 | { | |
| 1982 | auto __n = ranges::size(_M_base); | |
| 1983 | return __detail::min(__n, static_cast<decltype(__n)>(_M_count)); | |
| 1984 | } | |
| 1985 | ||
| 1986 | constexpr auto | |
| 1987 | size() const requires sized_range<const _Vp> | |
| 1988 | { | |
| 1989 | auto __n = ranges::size(_M_base); | |
| 1990 | return __detail::min(__n, static_cast<decltype(__n)>(_M_count)); | |
| 1991 | } | |
| 1992 | }; | |
| 1993 | ||
| 1994 | template<range _Range> | |
| 1995 | take_view(_Range&&, range_difference_t<_Range>) | |
| 1996 | -> take_view<all_view<_Range>>; | |
| 1997 | ||
| 1998 | namespace views | |
| 1999 | { | |
| 2000 | inline constexpr __adaptor::_RangeAdaptor take | |
| 2001 | = [] <viewable_range _Range, typename _Tp> (_Range&& __r, _Tp&& __n) | |
| 2002 | { | |
| 2003 | return take_view{std::forward<_Range>(__r), std::forward<_Tp>(__n)}; | |
| 2004 | }; | |
| 2005 | } // namespace views | |
| 2006 | ||
| 2007 | template<view _Vp, typename _Pred> | |
| 2008 | requires input_range<_Vp> && is_object_v<_Pred> | |
| 2009 | && indirect_unary_predicate<const _Pred, iterator_t<_Vp>> | |
| 2010 | class take_while_view : public view_interface<take_while_view<_Vp, _Pred>> | |
| 2011 | { | |
| 2012 | template<bool _Const> | |
| 2013 | struct _Sentinel | |
| 2014 | { | |
| 2015 | private: | |
| 2016 | using _Base = conditional_t<_Const, const _Vp, _Vp>; | |
| 2017 | ||
| 2018 | sentinel_t<_Base> _M_end = sentinel_t<_Base>(); | |
| 2019 | const _Pred* _M_pred = nullptr; | |
| 2020 | ||
| 2021 | public: | |
| 2022 | _Sentinel() = default; | |
| 2023 | ||
| 2024 | constexpr explicit | |
| 2025 | _Sentinel(sentinel_t<_Base> __end, const _Pred* __pred) | |
| 2026 | : _M_end(__end), _M_pred(__pred) | |
| 2027 | { } | |
| 2028 | ||
| 2029 | constexpr | |
| 2030 | _Sentinel(_Sentinel<!_Const> __s) | |
| 2031 | requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>> | |
| 2032 | : _M_end(__s._M_end), _M_pred(__s._M_pred) | |
| 2033 | { } | |
| 2034 | ||
| 2035 | constexpr sentinel_t<_Base> | |
| 2036 | base() const { return _M_end; } | |
| 2037 | ||
| 2038 | friend constexpr bool | |
| 2039 | operator==(const iterator_t<_Base>& __x, const _Sentinel& __y) | |
| 2040 | { return __y._M_end == __x || !std::__invoke(*__y._M_pred, *__x); } | |
| 2041 | }; | |
| 2042 | ||
| 2043 | _Vp _M_base; | |
| 2044 | __detail::__box<_Pred> _M_pred; | |
| 2045 | ||
| 2046 | public: | |
| 2047 | take_while_view() = default; | |
| 2048 | ||
| 2049 | constexpr | |
| 2050 | take_while_view(_Vp base, _Pred __pred) | |
| 2051 | : _M_base(std::move(base)), _M_pred(std::move(__pred)) | |
| 2052 | { | |
| 2053 | } | |
| 2054 | ||
| 2055 | constexpr _Vp | |
| 2056 | base() const& requires copy_constructible<_Vp> | |
| 2057 | { return _M_base; } | |
| 2058 | ||
| 2059 | constexpr _Vp | |
| 2060 | base() && | |
| 2061 | { return std::move(_M_base); } | |
| 2062 | ||
| 2063 | constexpr const _Pred& | |
| 2064 | pred() const | |
| 2065 | { return *_M_pred; } | |
| 2066 | ||
| 2067 | constexpr auto | |
| 2068 | begin() requires (!__detail::__simple_view<_Vp>) | |
| 2069 | { return ranges::begin(_M_base); } | |
| 2070 | ||
| 2071 | constexpr auto | |
| 2072 | begin() const requires range<const _Vp> | |
| 2073 | { return ranges::begin(_M_base); } | |
| 2074 | ||
| 2075 | constexpr auto | |
| 2076 | end() requires (!__detail::__simple_view<_Vp>) | |
| 2077 | { return _Sentinel<false>(ranges::end(_M_base), | |
| 2078 | std::__addressof(*_M_pred)); } | |
| 2079 | ||
| 2080 | constexpr auto | |
| 2081 | end() const requires range<const _Vp> | |
| 2082 | { return _Sentinel<true>(ranges::end(_M_base), | |
| 2083 | std::__addressof(*_M_pred)); } | |
| 2084 | }; | |
| 2085 | ||
| 2086 | template<typename _Range, typename _Pred> | |
| 2087 | take_while_view(_Range&&, _Pred) | |
| 2088 | -> take_while_view<all_view<_Range>, _Pred>; | |
| 2089 | ||
| 2090 | namespace views | |
| 2091 | { | |
| 2092 | inline constexpr __adaptor::_RangeAdaptor take_while | |
| 2093 | = [] <viewable_range _Range, typename _Pred> (_Range&& __r, _Pred&& __p) | |
| 2094 | { | |
| 2095 | return take_while_view{std::forward<_Range>(__r), std::forward<_Pred>(__p)}; | |
| 2096 | }; | |
| 2097 | } // namespace views | |
| 2098 | ||
| 2099 | template<view _Vp> | |
| 2100 | class drop_view : public view_interface<drop_view<_Vp>> | |
| 2101 | { | |
| 2102 | private: | |
| 2103 | _Vp _M_base; | |
| 2104 | range_difference_t<_Vp> _M_count; | |
| 2105 | ||
| 2106 | public: | |
| 2107 | drop_view() = default; | |
| 2108 | ||
| 2109 | constexpr | |
| 2110 | drop_view(_Vp __base, range_difference_t<_Vp> __count) | |
| 2111 | : _M_base(std::move(__base)), _M_count(__count) | |
| 2112 | { __glibcxx_assert(__count >= 0); } | |
| 2113 | ||
| 2114 | constexpr _Vp | |
| 2115 | base() const& requires copy_constructible<_Vp> | |
| 2116 | { return _M_base; } | |
| 2117 | ||
| 2118 | constexpr _Vp | |
| 2119 | base() && | |
| 2120 | { return std::move(_M_base); } | |
| 2121 | ||
| 2122 | constexpr auto | |
| 2123 | begin() requires (!(__detail::__simple_view<_Vp> | |
| 2124 | && random_access_range<_Vp>)) | |
| 2125 | { | |
| 2126 | // XXX: we need to cache the result here as per [range.drop.view] | |
| 2127 | return ranges::next(ranges::begin(_M_base), _M_count, | |
| 2128 | ranges::end(_M_base)); | |
| 2129 | } | |
| 2130 | ||
| 2131 | constexpr auto | |
| 2132 | begin() const requires random_access_range<const _Vp> | |
| 2133 | { | |
| 2134 | return ranges::next(ranges::begin(_M_base), _M_count, | |
| 2135 | ranges::end(_M_base)); | |
| 2136 | } | |
| 2137 | ||
| 2138 | constexpr auto | |
| 2139 | end() requires (!__detail::__simple_view<_Vp>) | |
| 2140 | { return ranges::end(_M_base); } | |
| 2141 | ||
| 2142 | constexpr auto | |
| 2143 | end() const requires range<const _Vp> | |
| 2144 | { return ranges::end(_M_base); } | |
| 2145 | ||
| 2146 | constexpr auto | |
| 2147 | size() requires sized_range<_Vp> | |
| 2148 | { | |
| 2149 | const auto __s = ranges::size(_M_base); | |
| 2150 | const auto __c = static_cast<decltype(__s)>(_M_count); | |
| 2151 | return __s < __c ? 0 : __s - __c; | |
| 2152 | } | |
| 2153 | ||
| 2154 | constexpr auto | |
| 2155 | size() const requires sized_range<const _Vp> | |
| 2156 | { | |
| 2157 | const auto __s = ranges::size(_M_base); | |
| 2158 | const auto __c = static_cast<decltype(__s)>(_M_count); | |
| 2159 | return __s < __c ? 0 : __s - __c; | |
| 2160 | } | |
| 2161 | }; | |
| 2162 | ||
| 2163 | template<typename _Range> | |
| 2164 | drop_view(_Range&&, range_difference_t<_Range>) | |
| 2165 | -> drop_view<all_view<_Range>>; | |
| 2166 | ||
| 2167 | namespace views | |
| 2168 | { | |
| 2169 | inline constexpr __adaptor::_RangeAdaptor drop | |
| 2170 | = [] <viewable_range _Range, typename _Tp> (_Range&& __r, _Tp&& __n) | |
| 2171 | { | |
| 2172 | return drop_view{std::forward<_Range>(__r), std::forward<_Tp>(__n)}; | |
| 2173 | }; | |
| 2174 | } // namespace views | |
| 2175 | ||
| 2176 | template<view _Vp, typename _Pred> | |
| 2177 | requires input_range<_Vp> && is_object_v<_Pred> | |
| 2178 | && indirect_unary_predicate<const _Pred, iterator_t<_Vp>> | |
| 2179 | class drop_while_view : public view_interface<drop_while_view<_Vp, _Pred>> | |
| 2180 | { | |
| 2181 | private: | |
| 2182 | _Vp _M_base; | |
| 2183 | __detail::__box<_Pred> _M_pred; | |
| 2184 | ||
| 2185 | public: | |
| 2186 | drop_while_view() = default; | |
| 2187 | ||
| 2188 | constexpr | |
| 2189 | drop_while_view(_Vp __base, _Pred __pred) | |
| 2190 | : _M_base(std::move(__base)), _M_pred(std::move(__pred)) | |
| 2191 | { } | |
| 2192 | ||
| 2193 | constexpr _Vp | |
| 2194 | base() const& requires copy_constructible<_Vp> | |
| 2195 | { return _M_base; } | |
| 2196 | ||
| 2197 | constexpr _Vp | |
| 2198 | base() && | |
| 2199 | { return std::move(_M_base); } | |
| 2200 | ||
| 2201 | constexpr const _Pred& | |
| 2202 | pred() const | |
| 2203 | { return *_M_pred; } | |
| 2204 | ||
| 2205 | constexpr auto | |
| 2206 | begin() | |
| 2207 | { | |
| 2208 | // XXX: we need to cache the result here as per [range.drop.while.view] | |
| 2209 | return __detail::find_if_not(ranges::begin(_M_base), | |
| 2210 | ranges::end(_M_base), | |
| 2211 | std::cref(*_M_pred)); | |
| 2212 | } | |
| 2213 | ||
| 2214 | constexpr auto | |
| 2215 | end() | |
| 2216 | { return ranges::end(_M_base); } | |
| 2217 | }; | |
| 2218 | ||
| 2219 | template<typename _Range, typename _Pred> | |
| 2220 | drop_while_view(_Range&&, _Pred) | |
| 2221 | -> drop_while_view<all_view<_Range>, _Pred>; | |
| 2222 | ||
| 2223 | namespace views | |
| 2224 | { | |
| 2225 | inline constexpr __adaptor::_RangeAdaptor drop_while | |
| 2226 | = [] <viewable_range _Range, typename _Pred> (_Range&& __r, _Pred&& __p) | |
| 2227 | { | |
| 2228 | return drop_while_view{std::forward<_Range>(__r), | |
| 2229 | std::forward<_Pred>(__p)}; | |
| 2230 | }; | |
| 2231 | } // namespace views | |
| 2232 | ||
| 2233 | template<input_range _Vp> | |
| 2234 | requires view<_Vp> && input_range<range_reference_t<_Vp>> | |
| 2235 | && (is_reference_v<range_reference_t<_Vp>> | |
| 2236 | || view<range_value_t<_Vp>>) | |
| 2237 | class join_view : public view_interface<join_view<_Vp>> | |
| 2238 | { | |
| 2239 | private: | |
| 2240 | using _InnerRange = range_reference_t<_Vp>; | |
| 2241 | ||
| 2242 | template<bool _Const> | |
| 2243 | struct _Sentinel; | |
| 2244 | ||
| 2245 | template<bool _Const> | |
| 2246 | struct _Iterator | |
| 2247 | { | |
| 2248 | private: | |
| 2249 | using _Parent = conditional_t<_Const, const join_view, join_view>; | |
| 2250 | using _Base = conditional_t<_Const, const _Vp, _Vp>; | |
| 2251 | ||
| 2252 | static constexpr bool _S_ref_is_glvalue | |
| 2253 | = is_reference_v<range_reference_t<_Base>>; | |
| 2254 | ||
| 2255 | constexpr void | |
| 2256 | _M_satisfy() | |
| 2257 | { | |
| 2258 | auto __update_inner = [this] (range_reference_t<_Base> __x) -> auto& | |
| 2259 | { | |
| 2260 | if constexpr (_S_ref_is_glvalue) | |
| 2261 | return __x; | |
| 2262 | else | |
| 2263 | return (_M_parent->_M_inner = views::all(std::move(__x))); | |
| 2264 | }; | |
| 2265 | ||
| 2266 | for (; _M_outer != ranges::end(_M_parent->_M_base); ++_M_outer) | |
| 2267 | { | |
| 2268 | auto& inner = __update_inner(*_M_outer); | |
| 2269 | _M_inner = ranges::begin(inner); | |
| 2270 | if (_M_inner != ranges::end(inner)) | |
| 2271 | return; | |
| 2272 | } | |
| 2273 | ||
| 2274 | if constexpr (_S_ref_is_glvalue) | |
| 2275 | _M_inner = iterator_t<range_reference_t<_Base>>(); | |
| 2276 | } | |
| 2277 | ||
| 2278 | static constexpr auto | |
| 2279 | _S_iter_concept() | |
| 2280 | { | |
| 2281 | if constexpr (_S_ref_is_glvalue | |
| 2282 | && bidirectional_range<_Base> | |
| 2283 | && bidirectional_range<range_reference_t<_Base>>) | |
| 2284 | return bidirectional_iterator_tag{}; | |
| 2285 | else if constexpr (_S_ref_is_glvalue | |
| 2286 | && forward_range<_Base> | |
| 2287 | && forward_range<range_reference_t<_Base>>) | |
| 2288 | return forward_iterator_tag{}; | |
| 2289 | else | |
| 2290 | return input_iterator_tag{}; | |
| 2291 | } | |
| 2292 | ||
| 2293 | static constexpr auto | |
| 2294 | _S_iter_cat() | |
| 2295 | { | |
| 2296 | using _OuterCat | |
| 2297 | = iterator_traits<iterator_t<_Base>>::iterator_category; | |
| 2298 | using _InnerCat | |
| 2299 | = iterator_traits<iterator_t<range_reference_t<_Base>>> | |
| 2300 | ::iterator_category; | |
| 2301 | if constexpr (_S_ref_is_glvalue | |
| 2302 | && derived_from<_OuterCat, bidirectional_iterator_tag> | |
| 2303 | && derived_from<_InnerCat, bidirectional_iterator_tag>) | |
| 2304 | return bidirectional_iterator_tag{}; | |
| 2305 | else if constexpr (_S_ref_is_glvalue | |
| 2306 | && derived_from<_OuterCat, forward_iterator_tag> | |
| 2307 | && derived_from<_InnerCat, forward_iterator_tag>) | |
| 2308 | return forward_iterator_tag{}; | |
| 2309 | else if constexpr (derived_from<_OuterCat, input_iterator_tag> | |
| 2310 | && derived_from<_InnerCat, input_iterator_tag>) | |
| 2311 | return input_iterator_tag{}; | |
| 2312 | else | |
| 2313 | return output_iterator_tag{}; | |
| 2314 | } | |
| 2315 | ||
| 2316 | iterator_t<_Base> _M_outer = iterator_t<_Base>(); | |
| 2317 | iterator_t<range_reference_t<_Base>> _M_inner | |
| 2318 | = iterator_t<range_reference_t<_Base>>(); | |
| 2319 | _Parent* _M_parent = nullptr; | |
| 2320 | ||
| 2321 | public: | |
| 2322 | using iterator_concept = decltype(_S_iter_concept()); | |
| 2323 | using iterator_category = decltype(_S_iter_cat()); | |
| 2324 | using value_type = range_value_t<range_reference_t<_Base>>; | |
| 2325 | using difference_type | |
| 2326 | = common_type_t<range_difference_t<_Base>, | |
| 2327 | range_difference_t<range_reference_t<_Base>>>; | |
| 2328 | ||
| 2329 | _Iterator() = default; | |
| 2330 | ||
| 2331 | // XXX: had to change the type of __outer from iterator_t<_Vp> to | |
| 2332 | // iterator_t<_Base> here, a possible defect in the spec? | |
| 2333 | constexpr | |
| 2334 | _Iterator(_Parent& __parent, iterator_t<_Base> __outer) | |
| 2335 | : _M_outer(std::move(__outer)), | |
| 2336 | _M_parent(std::__addressof(__parent)) | |
| 2337 | { _M_satisfy(); } | |
| 2338 | ||
| 2339 | constexpr | |
| 2340 | _Iterator(_Iterator<!_Const> __i) | |
| 2341 | requires _Const | |
| 2342 | && convertible_to<iterator_t<_Vp>, iterator_t<_Base>> | |
| 2343 | && convertible_to<iterator_t<_InnerRange>, | |
| 2344 | iterator_t<range_reference_t<_Base>>> | |
| 2345 | : _M_outer(std::move(__i._M_outer)), _M_inner(__i._M_inner), | |
| 2346 | _M_parent(__i._M_parent) | |
| 2347 | { } | |
| 2348 | ||
| 2349 | constexpr decltype(auto) | |
| 2350 | operator*() const | |
| 2351 | { return *_M_inner; } | |
| 2352 | ||
| 2353 | constexpr iterator_t<_Base> | |
| 2354 | operator->() const | |
| 2355 | requires __detail::__has_arrow<iterator_t<_Base>> | |
| 2356 | && copyable<iterator_t<_Base>> | |
| 2357 | { return _M_inner; } | |
| 2358 | ||
| 2359 | constexpr _Iterator& | |
| 2360 | operator++() | |
| 2361 | { | |
| 2362 | auto&& __inner_range = [this] () -> decltype(auto) { | |
| 2363 | if constexpr (_S_ref_is_glvalue) | |
| 2364 | return *_M_outer; | |
| 2365 | else | |
| 2366 | return _M_parent->_M_inner; | |
| 2367 | }(); | |
| 2368 | if (++_M_inner == ranges::end(__inner_range)) | |
| 2369 | { | |
| 2370 | ++_M_outer; | |
| 2371 | _M_satisfy(); | |
| 2372 | } | |
| 2373 | return *this; | |
| 2374 | } | |
| 2375 | ||
| 2376 | constexpr void | |
| 2377 | operator++(int) | |
| 2378 | { ++*this; } | |
| 2379 | ||
| 2380 | constexpr _Iterator | |
| 2381 | operator++(int) | |
| 2382 | requires _S_ref_is_glvalue && forward_range<_Base> | |
| 2383 | && forward_range<range_reference_t<_Base>> | |
| 2384 | { | |
| 2385 | auto __tmp = *this; | |
| 2386 | ++*this; | |
| 2387 | return __tmp; | |
| 2388 | } | |
| 2389 | ||
| 2390 | constexpr _Iterator& | |
| 2391 | operator--() | |
| 2392 | requires _S_ref_is_glvalue && bidirectional_range<_Base> | |
| 2393 | && bidirectional_range<range_reference_t<_Base>> | |
| 2394 | { | |
| 2395 | if (_M_outer == ranges::end(_M_parent->_M_base)) | |
| 2396 | _M_inner = ranges::end(*--_M_outer); | |
| 2397 | while (_M_inner == ranges::begin(*_M_outer)) | |
| 2398 | _M_inner = ranges::end(*--_M_outer); | |
| 2399 | --_M_inner; | |
| 2400 | return *this; | |
| 2401 | } | |
| 2402 | ||
| 2403 | constexpr _Iterator | |
| 2404 | operator--(int) | |
| 2405 | requires _S_ref_is_glvalue && bidirectional_range<_Base> | |
| 2406 | && bidirectional_range<range_reference_t<_Base>> | |
| 2407 | { | |
| 2408 | auto __tmp = *this; | |
| 2409 | --*this; | |
| 2410 | return __tmp; | |
| 2411 | } | |
| 2412 | ||
| 2413 | friend constexpr bool | |
| 2414 | operator==(const _Iterator& __x, const _Iterator& __y) | |
| 2415 | requires _S_ref_is_glvalue | |
| 2416 | && equality_comparable<iterator_t<_Base>> | |
| 2417 | && equality_comparable<iterator_t<range_reference_t<_Base>>> | |
| 2418 | { | |
| 2419 | return (__x._M_outer == __y._M_outer | |
| 2420 | && __x._M_inner == __y._M_inner); | |
| 2421 | } | |
| 2422 | ||
| 2423 | friend constexpr decltype(auto) | |
| 2424 | iter_move(const _Iterator& __i) | |
| 2425 | noexcept(noexcept(ranges::iter_move(__i._M_inner))) | |
| 2426 | { return ranges::iter_move(__i._M_inner); } | |
| 2427 | ||
| 2428 | friend constexpr void | |
| 2429 | iter_swap(const _Iterator& __x, const _Iterator& __y) | |
| 2430 | noexcept(noexcept(ranges::iter_swap(__x._M_inner, __y._M_inner))) | |
| 2431 | { return ranges::iter_swap(__x._M_inner, __y._M_inner); } | |
| 2432 | ||
| 2433 | friend _Sentinel<_Const>; | |
| 2434 | }; | |
| 2435 | ||
| 2436 | template<bool _Const> | |
| 2437 | struct _Sentinel | |
| 2438 | { | |
| 2439 | private: | |
| 2440 | using _Parent = conditional_t<_Const, const join_view, join_view>; | |
| 2441 | using _Base = conditional_t<_Const, const _Vp, _Vp>; | |
| 2442 | ||
| 2443 | constexpr bool | |
| 2444 | __equal(const _Iterator<_Const>& __i) const | |
| 2445 | { return __i._M_outer == _M_end; } | |
| 2446 | ||
| 2447 | sentinel_t<_Base> _M_end = sentinel_t<_Base>(); | |
| 2448 | ||
| 2449 | public: | |
| 2450 | _Sentinel() = default; | |
| 2451 | ||
| 2452 | constexpr explicit | |
| 2453 | _Sentinel(_Parent& __parent) | |
| 2454 | : _M_end(ranges::end(__parent._M_base)) | |
| 2455 | { } | |
| 2456 | ||
| 2457 | constexpr | |
| 2458 | _Sentinel(_Sentinel<!_Const> __s) | |
| 2459 | requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>> | |
| 2460 | : _M_end(std::move(__s._M_end)) | |
| 2461 | { } | |
| 2462 | ||
| 2463 | friend constexpr bool | |
| 2464 | operator==(const _Iterator<_Const>& __x, const _Sentinel& __y) | |
| 2465 | { return __y.__equal(__x); } | |
| 2466 | }; | |
| 2467 | ||
| 2468 | _Vp _M_base = _Vp(); | |
| 2469 | ||
| 2470 | // XXX: _M_inner is "present only when !is_reference_v<_InnerRange>" | |
| 2471 | // Applied P3278 and made this field mutable. | |
| 2472 | [[no_unique_address]] mutable | |
| 2473 | conditional_t<!is_reference_v<_InnerRange>, | |
| 2474 | all_view<_InnerRange>, __detail::_Empty> _M_inner; | |
| 2475 | ||
| 2476 | public: | |
| 2477 | join_view() = default; | |
| 2478 | ||
| 2479 | constexpr explicit | |
| 2480 | join_view(_Vp __base) | |
| 2481 | : _M_base(std::move(__base)) | |
| 2482 | { } | |
| 2483 | ||
| 2484 | /* XXX: P3280 removes this constructor | |
| 2485 | template<input_range _Range> | |
| 2486 | requires viewable_range<_Range> | |
| 2487 | && constructible_from<_Vp, all_view<_Range>> | |
| 2488 | constexpr explicit | |
| 2489 | join_view(_Range&& __r) | |
| 2490 | : _M_base(views::all(std::forward<_Range>(__r))) | |
| 2491 | { } | |
| 2492 | */ | |
| 2493 | ||
| 2494 | constexpr _Vp | |
| 2495 | base() const& requires copy_constructible<_Vp> | |
| 2496 | { return _M_base; } | |
| 2497 | ||
| 2498 | constexpr _Vp | |
| 2499 | base() && | |
| 2500 | { return std::move(_M_base); } | |
| 2501 | ||
| 2502 | constexpr auto | |
| 2503 | begin() | |
| 2504 | { | |
| 2505 | return _Iterator<__detail::__simple_view<_Vp>>{*this, | |
| 2506 | ranges::begin(_M_base)}; | |
| 2507 | } | |
| 2508 | ||
| 2509 | constexpr auto | |
| 2510 | begin() const | |
| 2511 | requires input_range<const _Vp> | |
| 2512 | && is_reference_v<range_reference_t<const _Vp>> | |
| 2513 | { | |
| 2514 | return _Iterator<true>{*this, ranges::begin(_M_base)}; | |
| 2515 | } | |
| 2516 | ||
| 2517 | constexpr auto | |
| 2518 | end() | |
| 2519 | { | |
| 2520 | if constexpr (forward_range<_Vp> && is_reference_v<_InnerRange> | |
| 2521 | && forward_range<_InnerRange> | |
| 2522 | && common_range<_Vp> && common_range<_InnerRange>) | |
| 2523 | return _Iterator<__detail::__simple_view<_Vp>>{*this, | |
| 2524 | ranges::end(_M_base)}; | |
| 2525 | else | |
| 2526 | return _Sentinel<__detail::__simple_view<_Vp>>{*this}; | |
| 2527 | } | |
| 2528 | ||
| 2529 | constexpr auto | |
| 2530 | end() const | |
| 2531 | requires input_range<const _Vp> | |
| 2532 | && is_reference_v<range_reference_t<const _Vp>> | |
| 2533 | { | |
| 2534 | if constexpr (forward_range<const _Vp> | |
| 2535 | && is_reference_v<range_reference_t<const _Vp>> | |
| 2536 | && forward_range<range_reference_t<const _Vp>> | |
| 2537 | && common_range<const _Vp> | |
| 2538 | && common_range<range_reference_t<const _Vp>>) | |
| 2539 | return _Iterator<true>{*this, ranges::end(_M_base)}; | |
| 2540 | else | |
| 2541 | return _Sentinel<true>{*this}; | |
| 2542 | } | |
| 2543 | }; | |
| 2544 | ||
| 2545 | template<typename _Range> | |
| 2546 | explicit join_view(_Range&&) -> join_view<all_view<_Range>>; | |
| 2547 | ||
| 2548 | namespace views | |
| 2549 | { | |
| 2550 | inline constexpr __adaptor::_RangeAdaptorClosure join | |
| 2551 | = [] <viewable_range _Range> (_Range&& __r) | |
| 2552 | { | |
| 2553 | return join_view{std::forward<_Range>(__r)}; | |
| 2554 | }; | |
| 2555 | } // namespace views | |
| 2556 | ||
| 2557 | namespace __detail | |
| 2558 | { | |
| 2559 | template<auto> | |
| 2560 | struct __require_constant; | |
| 2561 | ||
| 2562 | template<typename _Range> | |
| 2563 | concept __tiny_range = sized_range<_Range> | |
| 2564 | && requires | |
| 2565 | { typename __require_constant<remove_reference_t<_Range>::size()>; } | |
| 2566 | && (remove_reference_t<_Range>::size() <= 1); | |
| 2567 | } | |
| 2568 | ||
| 2569 | template<input_range _Vp, forward_range _Pattern> | |
| 2570 | requires view<_Vp> && view<_Pattern> | |
| 2571 | && indirectly_comparable<iterator_t<_Vp>, iterator_t<_Pattern>, | |
| 2572 | ranges::equal_to> | |
| 2573 | && (forward_range<_Vp> || __detail::__tiny_range<_Pattern>) | |
| 2574 | class split_view : public view_interface<split_view<_Vp, _Pattern>> | |
| 2575 | { | |
| 2576 | private: | |
| 2577 | template<bool _Const> | |
| 2578 | struct _InnerIter; | |
| 2579 | ||
| 2580 | template<bool _Const> | |
| 2581 | struct _OuterIter | |
| 2582 | { | |
| 2583 | private: | |
| 2584 | using _Parent = conditional_t<_Const, const split_view, split_view>; | |
| 2585 | using _Base = conditional_t<_Const, const _Vp, _Vp>; | |
| 2586 | ||
| 2587 | constexpr bool | |
| 2588 | __at_end() const | |
| 2589 | { return _M_current == ranges::end(_M_parent->_M_base); } | |
| 2590 | ||
| 2591 | // XXX: [24.7.11.3.1] | |
| 2592 | // Many of the following specifications refer to the notional member | |
| 2593 | // current of outer-iterator. current is equivalent to current_Â if | |
| 2594 | // V models forward_range, and parent_->current_Â otherwise. | |
| 2595 | constexpr auto& | |
| 2596 | __current() | |
| 2597 | { | |
| 2598 | if constexpr (forward_range<_Vp>) | |
| 2599 | return _M_current; | |
| 2600 | else | |
| 2601 | return _M_parent->_M_current; | |
| 2602 | } | |
| 2603 | ||
| 2604 | constexpr auto& | |
| 2605 | __current() const | |
| 2606 | { | |
| 2607 | if constexpr (forward_range<_Vp>) | |
| 2608 | return _M_current; | |
| 2609 | else | |
| 2610 | return _M_parent->_M_current; | |
| 2611 | } | |
| 2612 | ||
| 2613 | _Parent* _M_parent = nullptr; | |
| 2614 | ||
| 2615 | // XXX: _M_current is present only if "V models forward_range" | |
| 2616 | [[no_unique_address]] | |
| 2617 | conditional_t<forward_range<_Vp>, | |
| 2618 | iterator_t<_Base>, __detail::_Empty> _M_current; | |
| 2619 | ||
| 2620 | public: | |
| 2621 | using iterator_concept = conditional_t<forward_range<_Base>, | |
| 2622 | forward_iterator_tag, | |
| 2623 | input_iterator_tag>; | |
| 2624 | using iterator_category = input_iterator_tag; | |
| 2625 | using difference_type = range_difference_t<_Base>; | |
| 2626 | ||
| 2627 | struct value_type : view_interface<value_type> | |
| 2628 | { | |
| 2629 | private: | |
| 2630 | _OuterIter _M_i = _OuterIter(); | |
| 2631 | ||
| 2632 | public: | |
| 2633 | value_type() = default; | |
| 2634 | ||
| 2635 | constexpr explicit | |
| 2636 | value_type(_OuterIter __i) | |
| 2637 | : _M_i(std::move(__i)) | |
| 2638 | { } | |
| 2639 | ||
| 2640 | constexpr _InnerIter<_Const> | |
| 2641 | begin() const | |
| 2642 | requires copyable<_OuterIter> | |
| 2643 | { return _InnerIter<_Const>{_M_i}; } | |
| 2644 | ||
| 2645 | constexpr _InnerIter<_Const> | |
| 2646 | begin() | |
| 2647 | requires (!copyable<_OuterIter>) | |
| 2648 | { return _InnerIter<_Const>{std::move(_M_i)}; } | |
| 2649 | ||
| 2650 | constexpr default_sentinel_t | |
| 2651 | end() const | |
| 2652 | { return default_sentinel; } | |
| 2653 | }; | |
| 2654 | ||
| 2655 | _OuterIter() = default; | |
| 2656 | ||
| 2657 | constexpr explicit | |
| 2658 | _OuterIter(_Parent& __parent) requires (!forward_range<_Base>) | |
| 2659 | : _M_parent(address(__parent)) | |
| 2660 | { } | |
| 2661 | ||
| 2662 | constexpr | |
| 2663 | _OuterIter(_Parent& __parent, iterator_t<_Base> __current) | |
| 2664 | requires forward_range<_Base> | |
| 2665 | : _M_parent(std::__addressof(__parent)), | |
| 2666 | _M_current(std::move(__current)) | |
| 2667 | { } | |
| 2668 | ||
| 2669 | constexpr | |
| 2670 | _OuterIter(_OuterIter<!_Const> __i) | |
| 2671 | requires _Const | |
| 2672 | && convertible_to<iterator_t<_Vp>, iterator_t<const _Vp>> | |
| 2673 | : _M_parent(__i._M_parent), _M_current(std::move(__i._M_current)) | |
| 2674 | { } | |
| 2675 | ||
| 2676 | constexpr value_type | |
| 2677 | operator*() const | |
| 2678 | { return value_type{*this}; } | |
| 2679 | ||
| 2680 | constexpr _OuterIter& | |
| 2681 | operator++() | |
| 2682 | { | |
| 2683 | const auto __end = ranges::end(_M_parent->_M_base); | |
| 2684 | if (_M_current == __end) | |
| 2685 | return *this; | |
| 2686 | const auto [__pbegin, __pend] = subrange{_M_parent->_M_pattern}; | |
| 2687 | if (__pbegin == __pend) | |
| 2688 | ++_M_current; | |
| 2689 | else | |
| 2690 | do | |
| 2691 | { | |
| 2692 | auto [__b, __p] | |
| 2693 | = __detail::mismatch(std::move(_M_current), __end, | |
| 2694 | __pbegin, __pend); | |
| 2695 | _M_current = std::move(__b); | |
| 2696 | if (__p == __pend) | |
| 2697 | break; | |
| 2698 | } while (++_M_current != __end); | |
| 2699 | return *this; | |
| 2700 | } | |
| 2701 | ||
| 2702 | constexpr decltype(auto) | |
| 2703 | operator++(int) | |
| 2704 | { | |
| 2705 | if constexpr (forward_range<_Base>) | |
| 2706 | { | |
| 2707 | auto __tmp = *this; | |
| 2708 | ++*this; | |
| 2709 | return __tmp; | |
| 2710 | } | |
| 2711 | else | |
| 2712 | ++*this; | |
| 2713 | } | |
| 2714 | ||
| 2715 | friend constexpr bool | |
| 2716 | operator==(const _OuterIter& __x, const _OuterIter& __y) | |
| 2717 | requires forward_range<_Base> | |
| 2718 | { return __x._M_current == __y._M_current; } | |
| 2719 | ||
| 2720 | friend constexpr bool | |
| 2721 | operator==(const _OuterIter& __x, default_sentinel_t) | |
| 2722 | { return __x.__at_end(); }; | |
| 2723 | ||
| 2724 | friend _InnerIter<_Const>; | |
| 2725 | }; | |
| 2726 | ||
| 2727 | template<bool _Const> | |
| 2728 | struct _InnerIter | |
| 2729 | { | |
| 2730 | private: | |
| 2731 | using _Base = conditional_t<_Const, const _Vp, _Vp>; | |
| 2732 | ||
| 2733 | constexpr bool | |
| 2734 | __at_end() const | |
| 2735 | { | |
| 2736 | auto [__pcur, __pend] = subrange{_M_i._M_parent->_M_pattern}; | |
| 2737 | auto __end = ranges::end(_M_i._M_parent->_M_base); | |
| 2738 | if constexpr (__detail::__tiny_range<_Pattern>) | |
| 2739 | { | |
| 2740 | const auto& __cur = _M_i.__current(); | |
| 2741 | if (__cur == __end) | |
| 2742 | return true; | |
| 2743 | if (__pcur == __pend) | |
| 2744 | return _M_incremented; | |
| 2745 | return *__cur == *__pcur; | |
| 2746 | } | |
| 2747 | else | |
| 2748 | { | |
| 2749 | auto __cur = _M_i.__current(); | |
| 2750 | if (__cur == __end) | |
| 2751 | return true; | |
| 2752 | if (__pcur == __pend) | |
| 2753 | return _M_incremented; | |
| 2754 | do | |
| 2755 | { | |
| 2756 | if (*__cur != *__pcur) | |
| 2757 | return false; | |
| 2758 | if (++__pcur == __pend) | |
| 2759 | return true; | |
| 2760 | } while (++__cur != __end); | |
| 2761 | return false; | |
| 2762 | } | |
| 2763 | } | |
| 2764 | ||
| 2765 | static constexpr auto | |
| 2766 | _S_iter_cat() | |
| 2767 | { | |
| 2768 | using _Cat = iterator_traits<iterator_t<_Base>>::iterator_category; | |
| 2769 | if constexpr (derived_from<_Cat, forward_iterator_tag>) | |
| 2770 | return forward_iterator_tag{}; | |
| 2771 | else | |
| 2772 | return _Cat{}; | |
| 2773 | } | |
| 2774 | ||
| 2775 | static constexpr decltype(auto) | |
| 2776 | __iter_move(const _InnerIter& __i = {}) | |
| 2777 | noexcept(noexcept(ranges::iter_move(__i._M_i.__current()))) | |
| 2778 | { return ranges::iter_move(__i._M_i.__current()); } | |
| 2779 | ||
| 2780 | static constexpr void | |
| 2781 | __iter_swap(const _InnerIter& __x = {}, const _InnerIter& __y = {}) | |
| 2782 | noexcept(noexcept(ranges::iter_swap(__x._M_i.__current(), | |
| 2783 | __y._M_i.__current()))) | |
| 2784 | { ranges::iter_swap(__x._M_i.__current(), __y._M_i.__current()); } | |
| 2785 | ||
| 2786 | _OuterIter<_Const> _M_i = _OuterIter<_Const>(); | |
| 2787 | bool _M_incremented = false; | |
| 2788 | ||
| 2789 | public: | |
| 2790 | using iterator_concept = typename _OuterIter<_Const>::iterator_concept; | |
| 2791 | using iterator_category = decltype(_S_iter_cat()); | |
| 2792 | using value_type = range_value_t<_Base>; | |
| 2793 | using difference_type = range_difference_t<_Base>; | |
| 2794 | ||
| 2795 | _InnerIter() = default; | |
| 2796 | ||
| 2797 | constexpr explicit | |
| 2798 | _InnerIter(_OuterIter<_Const> __i) | |
| 2799 | : _M_i(std::move(__i)) | |
| 2800 | { } | |
| 2801 | ||
| 2802 | constexpr decltype(auto) | |
| 2803 | operator*() const | |
| 2804 | { return *_M_i._M_current; } | |
| 2805 | ||
| 2806 | constexpr _InnerIter& | |
| 2807 | operator++() | |
| 2808 | { | |
| 2809 | _M_incremented = true; | |
| 2810 | if constexpr (!forward_range<_Base>) | |
| 2811 | if constexpr (_Pattern::size() == 0) | |
| 2812 | return *this; | |
| 2813 | ++_M_i.__current(); | |
| 2814 | return *this; | |
| 2815 | } | |
| 2816 | ||
| 2817 | constexpr decltype(auto) | |
| 2818 | operator++(int) | |
| 2819 | { | |
| 2820 | if constexpr (forward_range<_Vp>) | |
| 2821 | { | |
| 2822 | auto __tmp = *this; | |
| 2823 | ++*this; | |
| 2824 | return __tmp; | |
| 2825 | } | |
| 2826 | else | |
| 2827 | ++*this; | |
| 2828 | } | |
| 2829 | ||
| 2830 | friend constexpr bool | |
| 2831 | operator==(const _InnerIter& __x, const _InnerIter& __y) | |
| 2832 | requires forward_range<_Base> | |
| 2833 | { return __x._M_i.__current() == __y._M_i.__current(); } | |
| 2834 | ||
| 2835 | friend constexpr bool | |
| 2836 | operator==(const _InnerIter& __x, default_sentinel_t) | |
| 2837 | { return __x.__at_end(); } | |
| 2838 | ||
| 2839 | friend constexpr decltype(auto) | |
| 2840 | iter_move(const _InnerIter& __i) noexcept(noexcept(__iter_move())) | |
| 2841 | { return __iter_move(__i); } | |
| 2842 | ||
| 2843 | friend constexpr void | |
| 2844 | iter_swap(const _InnerIter& __x, const _InnerIter& __y) | |
| 2845 | noexcept(noexcept(__iter_swap())) | |
| 2846 | requires indirectly_swappable<iterator_t<_Base>> | |
| 2847 | { __iter_swap(__x, __y); } | |
| 2848 | }; | |
| 2849 | ||
| 2850 | _Vp _M_base = _Vp(); | |
| 2851 | _Pattern _M_pattern = _Pattern(); | |
| 2852 | ||
| 2853 | // XXX: _M_current is "present only if !forward_range<V>" | |
| 2854 | [[no_unique_address]] | |
| 2855 | conditional_t<!forward_range<_Vp>, | |
| 2856 | iterator_t<_Vp>, __detail::_Empty> _M_current; | |
| 2857 | ||
| 2858 | ||
| 2859 | public: | |
| 2860 | split_view() = default; | |
| 2861 | ||
| 2862 | constexpr | |
| 2863 | split_view(_Vp __base, _Pattern __pattern) | |
| 2864 | : _M_base(std::move(__base)), _M_pattern(std::move(__pattern)) | |
| 2865 | { } | |
| 2866 | ||
| 2867 | /* XXX: P3280 removes this constructor | |
| 2868 | template<input_range _Range, forward_range _Pred> | |
| 2869 | requires constructible_from<_Vp, all_view<_Range>> | |
| 2870 | && constructible_from<_Pattern, all_view<_Pred>> | |
| 2871 | constexpr | |
| 2872 | split_view(_Range&& __r, _Pred&& __p) | |
| 2873 | : _M_base(views::all(std::forward<_Range>(__r))), | |
| 2874 | _M_pattern(views::all(std::forward<_Pred>(__p))) | |
| 2875 | { } | |
| 2876 | */ | |
| 2877 | ||
| 2878 | template<input_range _Range> | |
| 2879 | requires constructible_from<_Vp, all_view<_Range>> | |
| 2880 | && constructible_from<_Pattern, single_view<range_value_t<_Range>>> | |
| 2881 | constexpr | |
| 2882 | split_view(_Range&& __r, range_value_t<_Range> __e) | |
| 2883 | : _M_base(views::all(std::forward<_Range>(__r))), | |
| 2884 | _M_pattern(std::move(__e)) | |
| 2885 | { } | |
| 2886 | ||
| 2887 | constexpr _Vp | |
| 2888 | base() const& requires copy_constructible<_Vp> | |
| 2889 | { return _M_base; } | |
| 2890 | ||
| 2891 | constexpr _Vp | |
| 2892 | base() && | |
| 2893 | { return std::move(_M_base); } | |
| 2894 | ||
| 2895 | constexpr auto | |
| 2896 | begin() | |
| 2897 | { | |
| 2898 | if constexpr (forward_range<_Vp>) | |
| 2899 | return _OuterIter<__detail::__simple_view<_Vp>>{*this, | |
| 2900 | ranges::begin(_M_base)}; | |
| 2901 | else | |
| 2902 | { | |
| 2903 | _M_current = ranges::begin(_M_base); | |
| 2904 | return _OuterIter<false>{*this}; | |
| 2905 | } | |
| 2906 | } | |
| 2907 | ||
| 2908 | constexpr auto | |
| 2909 | begin() const requires forward_range<_Vp> && forward_range<const _Vp> | |
| 2910 | { | |
| 2911 | return _OuterIter<true>{*this, ranges::begin(_M_base)}; | |
| 2912 | } | |
| 2913 | ||
| 2914 | constexpr auto | |
| 2915 | end() requires forward_range<_Vp> && common_range<_Vp> | |
| 2916 | { | |
| 2917 | return _OuterIter<__detail::__simple_view<_Vp>>{*this, ranges::end(_M_base)}; | |
| 2918 | } | |
| 2919 | ||
| 2920 | constexpr auto | |
| 2921 | end() const | |
| 2922 | { | |
| 2923 | if constexpr (forward_range<_Vp> | |
| 2924 | && forward_range<const _Vp> | |
| 2925 | && common_range<const _Vp>) | |
| 2926 | return _OuterIter<true>{*this, ranges::end(_M_base)}; | |
| 2927 | else | |
| 2928 | return default_sentinel; | |
| 2929 | } | |
| 2930 | }; | |
| 2931 | ||
| 2932 | template<typename _Range, typename _Pred> | |
| 2933 | split_view(_Range&&, _Pred&&) | |
| 2934 | -> split_view<all_view<_Range>, all_view<_Pred>>; | |
| 2935 | ||
| 2936 | template<input_range _Range> | |
| 2937 | split_view(_Range&&, range_value_t<_Range>) | |
| 2938 | -> split_view<all_view<_Range>, single_view<range_value_t<_Range>>>; | |
| 2939 | ||
| 2940 | namespace views | |
| 2941 | { | |
| 2942 | inline constexpr __adaptor::_RangeAdaptor split | |
| 2943 | = [] <viewable_range _Range, typename _Fp> (_Range&& __r, _Fp&& __f) | |
| 2944 | { | |
| 2945 | return split_view{std::forward<_Range>(__r), std::forward<_Fp>(__f)}; | |
| 2946 | }; | |
| 2947 | } // namespace views | |
| 2948 | ||
| 2949 | namespace views | |
| 2950 | { | |
| 2951 | struct _Counted | |
| 2952 | { | |
| 2953 | template<input_or_output_iterator _Iter> | |
| 2954 | constexpr auto | |
| 2955 | operator()(_Iter __i, iter_difference_t<_Iter> __n) const | |
| 2956 | { | |
| 2957 | if constexpr (random_access_iterator<_Iter>) | |
| 2958 | return subrange{__i, __i + __n}; | |
| 2959 | else | |
| 2960 | return subrange{counted_iterator{std::move(__i), __n}, | |
| 2961 | default_sentinel}; | |
| 2962 | } | |
| 2963 | }; | |
| 2964 | ||
| 2965 | inline constexpr _Counted counted{}; | |
| 2966 | } // namespace views | |
| 2967 | ||
| 2968 | template<view _Vp> | |
| 2969 | requires (!common_range<_Vp>) && copyable<iterator_t<_Vp>> | |
| 2970 | class common_view : public view_interface<common_view<_Vp>> | |
| 2971 | { | |
| 2972 | private: | |
| 2973 | _Vp _M_base = _Vp(); | |
| 2974 | ||
| 2975 | public: | |
| 2976 | common_view() = default; | |
| 2977 | ||
| 2978 | constexpr explicit | |
| 2979 | common_view(_Vp __r) | |
| 2980 | : _M_base(std::move(__r)) | |
| 2981 | { } | |
| 2982 | ||
| 2983 | /* XXX: P3280 doesn't remove this constructor, but I think it should? | |
| 2984 | template<viewable_range _Range> | |
| 2985 | requires (!common_range<_Range>) && constructible_from<_Vp, all_view<_Range>> | |
| 2986 | constexpr explicit | |
| 2987 | common_view(_Range&& __r) | |
| 2988 | : _M_base(views::all(std::forward<_Range>(__r))) | |
| 2989 | { } | |
| 2990 | */ | |
| 2991 | ||
| 2992 | constexpr _Vp | |
| 2993 | base() const& requires copy_constructible<_Vp> | |
| 2994 | { return _M_base; } | |
| 2995 | ||
| 2996 | constexpr _Vp | |
| 2997 | base() && | |
| 2998 | { return std::move(_M_base); } | |
| 2999 | ||
| 3000 | constexpr auto | |
| 3001 | begin() | |
| 3002 | { | |
| 3003 | if constexpr (random_access_range<_Vp> && sized_range<_Vp>) | |
| 3004 | return ranges::begin(_M_base); | |
| 3005 | else | |
| 3006 | return common_iterator<iterator_t<_Vp>, sentinel_t<_Vp>> | |
| 3007 | (ranges::begin(_M_base)); | |
| 3008 | } | |
| 3009 | ||
| 3010 | constexpr auto | |
| 3011 | begin() const requires range<const _Vp> | |
| 3012 | { | |
| 3013 | if constexpr (random_access_range<const _Vp> && sized_range<const _Vp>) | |
| 3014 | return ranges::begin(_M_base); | |
| 3015 | else | |
| 3016 | return common_iterator<iterator_t<const _Vp>, sentinel_t<const _Vp>> | |
| 3017 | (ranges::begin(_M_base)); | |
| 3018 | } | |
| 3019 | ||
| 3020 | constexpr auto | |
| 3021 | end() | |
| 3022 | { | |
| 3023 | if constexpr (random_access_range<_Vp> && sized_range<_Vp>) | |
| 3024 | return ranges::begin(_M_base) + ranges::size(_M_base); | |
| 3025 | else | |
| 3026 | return common_iterator<iterator_t<_Vp>, sentinel_t<_Vp>> | |
| 3027 | (ranges::end(_M_base)); | |
| 3028 | } | |
| 3029 | ||
| 3030 | constexpr auto | |
| 3031 | end() const requires range<const _Vp> | |
| 3032 | { | |
| 3033 | if constexpr (random_access_range<const _Vp> && sized_range<const _Vp>) | |
| 3034 | return ranges::begin(_M_base) + ranges::size(_M_base); | |
| 3035 | else | |
| 3036 | return common_iterator<iterator_t<const _Vp>, sentinel_t<const _Vp>> | |
| 3037 | (ranges::end(_M_base)); | |
| 3038 | } | |
| 3039 | ||
| 3040 | constexpr auto | |
| 3041 | size() requires sized_range<_Vp> | |
| 3042 | { return ranges::size(_M_base); } | |
| 3043 | ||
| 3044 | constexpr auto | |
| 3045 | size() const requires sized_range<const _Vp> | |
| 3046 | { return ranges::size(_M_base); } | |
| 3047 | }; | |
| 3048 | ||
| 3049 | template<typename _Range> | |
| 3050 | common_view(_Range&&) -> common_view<all_view<_Range>>; | |
| 3051 | ||
| 3052 | namespace views | |
| 3053 | { | |
| 3054 | inline constexpr __adaptor::_RangeAdaptorClosure common | |
| 3055 | = [] <viewable_range _Range> (_Range&& __r) | |
| 3056 | { | |
| 3057 | if constexpr (common_range<_Range> | |
| 3058 | && requires { views::all(std::forward<_Range>(__r)); }) | |
| 3059 | return views::all(std::forward<_Range>(__r)); | |
| 3060 | else | |
| 3061 | return common_view{std::forward<_Range>(__r)}; | |
| 3062 | }; | |
| 3063 | ||
| 3064 | } // namespace views | |
| 3065 | ||
| 3066 | template<view _Vp> | |
| 3067 | requires bidirectional_range<_Vp> | |
| 3068 | class reverse_view : public view_interface<reverse_view<_Vp>> | |
| 3069 | { | |
| 3070 | private: | |
| 3071 | _Vp _M_base = _Vp(); | |
| 3072 | ||
| 3073 | public: | |
| 3074 | reverse_view() = default; | |
| 3075 | ||
| 3076 | constexpr explicit | |
| 3077 | reverse_view(_Vp __r) | |
| 3078 | : _M_base(std::move(__r)) | |
| 3079 | { } | |
| 3080 | ||
| 3081 | /* XXX: P3280 removes this constructor | |
| 3082 | template<viewable_range _Range> | |
| 3083 | requires bidirectional_range<_Range> && constructible_from<_Vp, all_view<_Range>> | |
| 3084 | constexpr explicit | |
| 3085 | reverse_view(_Range&& __r) | |
| 3086 | : _M_base(views::all(std::forward<_Range>(__r))) | |
| 3087 | { } | |
| 3088 | */ | |
| 3089 | ||
| 3090 | constexpr _Vp | |
| 3091 | base() const& requires copy_constructible<_Vp> | |
| 3092 | { return _M_base; } | |
| 3093 | ||
| 3094 | constexpr _Vp | |
| 3095 | base() && | |
| 3096 | { return std::move(_M_base); } | |
| 3097 | ||
| 3098 | constexpr reverse_iterator<iterator_t<_Vp>> | |
| 3099 | begin() | |
| 3100 | { | |
| 3101 | // XXX: we need to cache the result here as per [range.reverse.view] | |
| 3102 | return make_reverse_iterator(ranges::next(ranges::begin(_M_base), | |
| 3103 | ranges::end(_M_base))); | |
| 3104 | } | |
| 3105 | ||
| 3106 | constexpr auto | |
| 3107 | begin() requires common_range<_Vp> | |
| 3108 | { return make_reverse_iterator(ranges::end(_M_base)); } | |
| 3109 | ||
| 3110 | constexpr auto | |
| 3111 | begin() const requires common_range<const _Vp> | |
| 3112 | { return make_reverse_iterator(ranges::end(_M_base)); } | |
| 3113 | ||
| 3114 | constexpr reverse_iterator<iterator_t<_Vp>> | |
| 3115 | end() | |
| 3116 | { return make_reverse_iterator(ranges::begin(_M_base)); } | |
| 3117 | ||
| 3118 | constexpr auto | |
| 3119 | end() const requires common_range<const _Vp> | |
| 3120 | { return make_reverse_iterator(ranges::begin(_M_base)); } | |
| 3121 | ||
| 3122 | constexpr auto | |
| 3123 | size() requires sized_range<_Vp> | |
| 3124 | { return ranges::size(_M_base); } | |
| 3125 | ||
| 3126 | constexpr auto | |
| 3127 | size() const requires sized_range<const _Vp> | |
| 3128 | { return ranges::size(_M_base); } | |
| 3129 | }; | |
| 3130 | ||
| 3131 | template<typename _Range> | |
| 3132 | reverse_view(_Range&&) -> reverse_view<all_view<_Range>>; | |
| 3133 | ||
| 3134 | namespace views | |
| 3135 | { | |
| 3136 | namespace __detail | |
| 3137 | { | |
| 3138 | template<typename> | |
| 3139 | inline constexpr bool __is_reversible_subrange = false; | |
| 3140 | ||
| 3141 | template<typename _Iter, subrange_kind _Kind> | |
| 3142 | inline constexpr bool | |
| 3143 | __is_reversible_subrange<subrange<reverse_iterator<_Iter>, | |
| 3144 | reverse_iterator<_Iter>, | |
| 3145 | _Kind>> = true; | |
| 3146 | ||
| 3147 | template<typename> | |
| 3148 | inline constexpr bool __is_reverse_view = false; | |
| 3149 | ||
| 3150 | template<typename _Vp> | |
| 3151 | inline constexpr bool __is_reverse_view<reverse_view<_Vp>> = true; | |
| 3152 | } | |
| 3153 | ||
| 3154 | inline constexpr __adaptor::_RangeAdaptorClosure reverse | |
| 3155 | = [] <viewable_range _Range> (_Range&& __r) | |
| 3156 | { | |
| 3157 | using _Tp = remove_cvref_t<_Range>; | |
| 3158 | if constexpr (__detail::__is_reverse_view<_Tp>) | |
| 3159 | return std::forward<_Range>(__r).base(); | |
| 3160 | else if constexpr (__detail::__is_reversible_subrange<_Tp>) | |
| 3161 | { | |
| 3162 | using _Iter = decltype(ranges::begin(__r).base()); | |
| 3163 | if constexpr (sized_range<_Tp>) | |
| 3164 | return subrange<_Iter, _Iter, subrange_kind::sized> | |
| 3165 | (__r.end().base(), __r.begin().base(), __r.size()); | |
| 3166 | else | |
| 3167 | return subrange<_Iter, _Iter, subrange_kind::unsized> | |
| 3168 | (__r.end().base(), __r.begin().base()); | |
| 3169 | } | |
| 3170 | else | |
| 3171 | return reverse_view{std::forward<_Range>(__r)}; | |
| 3172 | }; | |
| 3173 | } // namespace views | |
| 3174 | ||
| 3175 | namespace __detail | |
| 3176 | { | |
| 3177 | template<typename _Tp, size_t _Nm> | |
| 3178 | concept __has_tuple_element = requires(_Tp __t) | |
| 3179 | { | |
| 3180 | typename tuple_size<_Tp>::type; | |
| 3181 | requires _Nm < tuple_size_v<_Tp>; | |
| 3182 | typename tuple_element_t<_Nm, _Tp>; | |
| 3183 | // XXX: we applied P3323 here | |
| 3184 | { std::get<_Nm>(__t) } | |
| 3185 | -> convertible_to<const tuple_element_t<_Nm, _Tp>&>; | |
| 3186 | }; | |
| 3187 | } | |
| 3188 | ||
| 3189 | template<input_range _Vp, size_t _Nm> | |
| 3190 | requires view<_Vp> | |
| 3191 | && __detail::__has_tuple_element<range_value_t<_Vp>, _Nm> | |
| 3192 | && __detail::__has_tuple_element<remove_reference_t<range_reference_t<_Vp>>, | |
| 3193 | _Nm> | |
| 3194 | class elements_view : public view_interface<elements_view<_Vp, _Nm>> | |
| 3195 | { | |
| 3196 | public: | |
| 3197 | elements_view() = default; | |
| 3198 | ||
| 3199 | constexpr explicit | |
| 3200 | elements_view(_Vp base) | |
| 3201 | : _M_base(std::move(base)) | |
| 3202 | { } | |
| 3203 | ||
| 3204 | constexpr _Vp | |
| 3205 | base() const& requires copy_constructible<_Vp> | |
| 3206 | { return _M_base; } | |
| 3207 | ||
| 3208 | constexpr _Vp | |
| 3209 | base() && | |
| 3210 | { return std::move(_M_base); } | |
| 3211 | ||
| 3212 | constexpr auto | |
| 3213 | begin() requires (!__detail::__simple_view<_Vp>) | |
| 3214 | { return _Iterator<false>(ranges::begin(_M_base)); } | |
| 3215 | ||
| 3216 | constexpr auto | |
| 3217 | begin() const requires __detail::__simple_view<_Vp> | |
| 3218 | { return _Iterator<true>(ranges::begin(_M_base)); } | |
| 3219 | ||
| 3220 | constexpr auto | |
| 3221 | end() requires (!__detail::__simple_view<_Vp>) | |
| 3222 | { return ranges::end(_M_base); } | |
| 3223 | ||
| 3224 | constexpr auto | |
| 3225 | end() const requires __detail::__simple_view<_Vp> | |
| 3226 | { return ranges::end(_M_base); } | |
| 3227 | ||
| 3228 | constexpr auto | |
| 3229 | size() requires sized_range<_Vp> | |
| 3230 | { return ranges::size(_M_base); } | |
| 3231 | ||
| 3232 | constexpr auto | |
| 3233 | size() const requires sized_range<const _Vp> | |
| 3234 | { return ranges::size(_M_base); } | |
| 3235 | ||
| 3236 | private: | |
| 3237 | template<bool _Const> | |
| 3238 | struct _Iterator | |
| 3239 | { | |
| 3240 | using _Base = conditional_t<_Const, const _Vp, _Vp>; | |
| 3241 | ||
| 3242 | iterator_t<_Base> _M_current; | |
| 3243 | ||
| 3244 | friend _Iterator<!_Const>; | |
| 3245 | ||
| 3246 | public: | |
| 3247 | using iterator_category | |
| 3248 | = typename iterator_traits<iterator_t<_Base>>::iterator_category; | |
| 3249 | using value_type | |
| 3250 | = remove_cvref_t<tuple_element_t<_Nm, range_value_t<_Base>>>; | |
| 3251 | using difference_type = range_difference_t<_Base>; | |
| 3252 | ||
| 3253 | _Iterator() = default; | |
| 3254 | ||
| 3255 | constexpr explicit | |
| 3256 | _Iterator(iterator_t<_Base> current) | |
| 3257 | : _M_current(std::move(current)) | |
| 3258 | { } | |
| 3259 | ||
| 3260 | constexpr | |
| 3261 | _Iterator(_Iterator<!_Const> i) | |
| 3262 | requires _Const && convertible_to<iterator_t<_Vp>, iterator_t<_Base>> | |
| 3263 | : _M_current(std::move(i._M_current)) | |
| 3264 | { } | |
| 3265 | ||
| 3266 | constexpr iterator_t<_Base> | |
| 3267 | base() const& | |
| 3268 | requires copyable<iterator_t<_Base>> | |
| 3269 | { return _M_current; } | |
| 3270 | ||
| 3271 | constexpr iterator_t<_Base> | |
| 3272 | base() && | |
| 3273 | { return std::move(_M_current); } | |
| 3274 | ||
| 3275 | constexpr decltype(auto) | |
| 3276 | operator*() const | |
| 3277 | { return std::get<_Nm>(*_M_current); } | |
| 3278 | ||
| 3279 | constexpr _Iterator& | |
| 3280 | operator++() | |
| 3281 | { | |
| 3282 | ++_M_current; | |
| 3283 | return *this; | |
| 3284 | } | |
| 3285 | ||
| 3286 | constexpr void | |
| 3287 | operator++(int) requires (!forward_range<_Base>) | |
| 3288 | { ++_M_current; } | |
| 3289 | ||
| 3290 | constexpr _Iterator | |
| 3291 | operator++(int) requires forward_range<_Base> | |
| 3292 | { | |
| 3293 | auto __tmp = *this; | |
| 3294 | ++_M_current; | |
| 3295 | return __tmp; | |
| 3296 | } | |
| 3297 | ||
| 3298 | constexpr _Iterator& | |
| 3299 | operator--() requires bidirectional_range<_Base> | |
| 3300 | { | |
| 3301 | --_M_current; | |
| 3302 | return *this; | |
| 3303 | } | |
| 3304 | ||
| 3305 | constexpr _Iterator | |
| 3306 | operator--(int) requires bidirectional_range<_Base> | |
| 3307 | { | |
| 3308 | auto __tmp = *this; | |
| 3309 | --_M_current; | |
| 3310 | return __tmp; | |
| 3311 | } | |
| 3312 | ||
| 3313 | constexpr _Iterator& | |
| 3314 | operator+=(difference_type __n) | |
| 3315 | requires random_access_range<_Base> | |
| 3316 | { | |
| 3317 | _M_current += __n; | |
| 3318 | return *this; | |
| 3319 | } | |
| 3320 | ||
| 3321 | constexpr _Iterator& | |
| 3322 | operator-=(difference_type __n) | |
| 3323 | requires random_access_range<_Base> | |
| 3324 | { | |
| 3325 | _M_current -= __n; | |
| 3326 | return *this; | |
| 3327 | } | |
| 3328 | ||
| 3329 | constexpr decltype(auto) | |
| 3330 | operator[](difference_type __n) const | |
| 3331 | requires random_access_range<_Base> | |
| 3332 | { return std::get<_Nm>(*(_M_current + __n)); } | |
| 3333 | ||
| 3334 | friend constexpr bool | |
| 3335 | operator==(const _Iterator& __x, const _Iterator& __y) | |
| 3336 | requires equality_comparable<iterator_t<_Base>> | |
| 3337 | { return __x._M_current == __y._M_current; } | |
| 3338 | ||
| 3339 | friend constexpr bool | |
| 3340 | operator==(const _Iterator& __x, const sentinel_t<_Base>& __y) | |
| 3341 | { return __x._M_current == __y; } | |
| 3342 | ||
| 3343 | friend constexpr bool | |
| 3344 | operator<(const _Iterator& __x, const _Iterator& __y) | |
| 3345 | requires random_access_range<_Base> | |
| 3346 | { return __x._M_current < __y._M_current; } | |
| 3347 | ||
| 3348 | friend constexpr bool | |
| 3349 | operator>(const _Iterator& __x, const _Iterator& __y) | |
| 3350 | requires random_access_range<_Base> | |
| 3351 | { return __y._M_current < __x._M_current; } | |
| 3352 | ||
| 3353 | friend constexpr bool | |
| 3354 | operator<=(const _Iterator& __x, const _Iterator& __y) | |
| 3355 | requires random_access_range<_Base> | |
| 3356 | { return !(__y._M_current > __x._M_current); } | |
| 3357 | ||
| 3358 | friend constexpr bool | |
| 3359 | operator>=(const _Iterator& __x, const _Iterator& __y) | |
| 3360 | requires random_access_range<_Base> | |
| 3361 | { return !(__x._M_current > __y._M_current); } | |
| 3362 | ||
| 3363 | #ifdef __cpp_lib_three_way_comparison | |
| 3364 | friend constexpr auto | |
| 3365 | operator<=>(const _Iterator& __x, const _Iterator& __y) | |
| 3366 | requires random_access_range<_Base> | |
| 3367 | && three_way_comparable<iterator_t<_Base>> | |
| 3368 | { return __x._M_current <=> __y._M_current; } | |
| 3369 | #endif | |
| 3370 | ||
| 3371 | friend constexpr _Iterator | |
| 3372 | operator+(const _Iterator& __x, difference_type __y) | |
| 3373 | requires random_access_range<_Base> | |
| 3374 | { return _Iterator{__x} += __y; } | |
| 3375 | ||
| 3376 | friend constexpr _Iterator | |
| 3377 | operator+(difference_type __x, const _Iterator& __y) | |
| 3378 | requires random_access_range<_Base> | |
| 3379 | { return __y + __x; } | |
| 3380 | ||
| 3381 | friend constexpr _Iterator | |
| 3382 | operator-(const _Iterator& __x, difference_type __y) | |
| 3383 | requires random_access_range<_Base> | |
| 3384 | { return _Iterator{__x} -= __y; } | |
| 3385 | ||
| 3386 | friend constexpr difference_type | |
| 3387 | operator-(const _Iterator& __x, const _Iterator& __y) | |
| 3388 | requires random_access_range<_Base> | |
| 3389 | { return __x._M_current - __y._M_current; } | |
| 3390 | ||
| 3391 | friend constexpr difference_type | |
| 3392 | operator-(const _Iterator<_Const>& __x, const sentinel_t<_Base>& __y) | |
| 3393 | requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base>> | |
| 3394 | { return __x._M_current - __y; } | |
| 3395 | ||
| 3396 | friend constexpr difference_type | |
| 3397 | operator-(const sentinel_t<_Base>& __x, const _Iterator<_Const>& __y) | |
| 3398 | requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base>> | |
| 3399 | { return -(__y - __x); } | |
| 3400 | }; | |
| 3401 | ||
| 3402 | _Vp _M_base = _Vp(); | |
| 3403 | }; | |
| 3404 | ||
| 3405 | template<typename _Range> | |
| 3406 | using keys_view = elements_view<all_view<_Range>, 0>; | |
| 3407 | ||
| 3408 | template<typename _Range> | |
| 3409 | using values_view = elements_view<all_view<_Range>, 1>; | |
| 3410 | ||
| 3411 | namespace views | |
| 3412 | { | |
| 3413 | template<size_t _Nm> | |
| 3414 | inline constexpr __adaptor::_RangeAdaptorClosure elements | |
| 3415 | = [] <viewable_range _Range> (_Range&& __r) | |
| 3416 | { | |
| 3417 | return elements_view<all_view<_Range>, _Nm>{std::forward<_Range>(__r)}; | |
| 3418 | }; | |
| 3419 | ||
| 3420 | inline constexpr __adaptor::_RangeAdaptorClosure keys = elements<0>; | |
| 3421 | inline constexpr __adaptor::_RangeAdaptorClosure values = elements<1>; | |
| 3422 | } // namespace views | |
| 3423 | ||
| 3424 | } // namespace ranges | |
| 3425 | ||
| 3426 | namespace views = ranges::views; | |
| 3427 | ||
| 3428 | template<typename _Iter, typename _Sent, ranges::subrange_kind _Kind> | |
| 3429 | struct tuple_size<ranges::subrange<_Iter, _Sent, _Kind>> | |
| 3430 | : integral_constant<size_t, 2> | |
| 3431 | { }; | |
| 3432 | ||
| 3433 | template<typename _Iter, typename _Sent, ranges::subrange_kind _Kind> | |
| 3434 | struct tuple_element<0, ranges::subrange<_Iter, _Sent, _Kind>> | |
| 3435 | { using type = _Iter; }; | |
| 3436 | ||
| 3437 | template<typename _Iter, typename _Sent, ranges::subrange_kind _Kind> | |
| 3438 | struct tuple_element<1, ranges::subrange<_Iter, _Sent, _Kind>> | |
| 3439 | { using type = _Sent; }; | |
| 3440 | ||
| 328b52d6 JW |
3441 | _GLIBCXX_END_NAMESPACE_VERSION |
| 3442 | } // namespace | |
| 3443 | #endif // library concepts | |
| 3444 | #endif // C++2a | |
| 3445 | #endif /* _GLIBCXX_RANGES */ |