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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 | 45 | #include <optional> |
cba9ef06 | 46 | #include <tuple> |
328b52d6 JW |
47 | |
48 | /** | |
49 | * @defgroup ranges Ranges | |
50 | * | |
51 | * Components for dealing with ranges of elements. | |
52 | */ | |
53 | ||
54 | namespace std _GLIBCXX_VISIBILITY(default) | |
55 | { | |
56 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
57 | namespace ranges | |
58 | { | |
59 | // [range.range] The range concept. | |
328b52d6 | 60 | // [range.sized] The sized_range concept. |
a7922ddf | 61 | // Defined in <bits/range_access.h> |
328b52d6 JW |
62 | |
63 | // [range.refinements] | |
a7922ddf | 64 | // Defined in <bits/range_access.h> |
37f33df7 JW |
65 | |
66 | struct view_base { }; | |
67 | ||
37f33df7 | 68 | template<typename _Tp> |
3841739c | 69 | inline constexpr bool enable_view = derived_from<_Tp, view_base>; |
37f33df7 JW |
70 | |
71 | template<typename _Tp> | |
72 | concept view | |
73 | = range<_Tp> && movable<_Tp> && default_initializable<_Tp> | |
74 | && enable_view<_Tp>; | |
75 | ||
b5b2e387 | 76 | /// A range which can be safely converted to a view. |
37f33df7 JW |
77 | template<typename _Tp> |
78 | concept viewable_range = range<_Tp> | |
15411a64 | 79 | && (borrowed_range<_Tp> || view<remove_cvref_t<_Tp>>); |
37f33df7 JW |
80 | |
81 | namespace __detail | |
82 | { | |
83 | template<typename _Range> | |
84 | concept __simple_view = view<_Range> && range<const _Range> | |
85 | && same_as<iterator_t<_Range>, iterator_t<const _Range>> | |
86 | && same_as<sentinel_t<_Range>, sentinel_t<const _Range>>; | |
87 | ||
88 | template<typename _It> | |
89 | concept __has_arrow = input_iterator<_It> | |
90 | && (is_pointer_v<_It> || requires(_It __it) { __it.operator->(); }); | |
91 | ||
92 | template<typename _Tp, typename _Up> | |
93 | concept __not_same_as | |
94 | = !same_as<remove_cvref_t<_Tp>, remove_cvref_t<_Up>>; | |
95 | } // namespace __detail | |
96 | ||
97 | template<typename _Derived> | |
98 | requires is_class_v<_Derived> && same_as<_Derived, remove_cv_t<_Derived>> | |
99 | class view_interface : public view_base | |
100 | { | |
101 | private: | |
102 | constexpr _Derived& _M_derived() noexcept | |
103 | { | |
104 | static_assert(derived_from<_Derived, view_interface<_Derived>>); | |
105 | static_assert(view<_Derived>); | |
106 | return static_cast<_Derived&>(*this); | |
107 | } | |
108 | ||
109 | constexpr const _Derived& _M_derived() const noexcept | |
110 | { | |
111 | static_assert(derived_from<_Derived, view_interface<_Derived>>); | |
112 | static_assert(view<_Derived>); | |
113 | return static_cast<const _Derived&>(*this); | |
114 | } | |
115 | ||
116 | public: | |
117 | constexpr bool | |
118 | empty() requires forward_range<_Derived> | |
119 | { return ranges::begin(_M_derived()) == ranges::end(_M_derived()); } | |
120 | ||
121 | constexpr bool | |
122 | empty() const requires forward_range<const _Derived> | |
123 | { return ranges::begin(_M_derived()) == ranges::end(_M_derived()); } | |
124 | ||
125 | constexpr explicit | |
126 | operator bool() requires requires { ranges::empty(_M_derived()); } | |
127 | { return !ranges::empty(_M_derived()); } | |
128 | ||
129 | constexpr explicit | |
130 | operator bool() const requires requires { ranges::empty(_M_derived()); } | |
131 | { return !ranges::empty(_M_derived()); } | |
132 | ||
133 | constexpr auto | |
134 | data() requires contiguous_iterator<iterator_t<_Derived>> | |
135 | { return to_address(ranges::begin(_M_derived())); } | |
136 | ||
137 | constexpr auto | |
138 | data() const | |
139 | requires range<const _Derived> | |
140 | && contiguous_iterator<iterator_t<const _Derived>> | |
141 | { return to_address(ranges::begin(_M_derived())); } | |
142 | ||
143 | constexpr auto | |
144 | size() | |
145 | requires forward_range<_Derived> | |
146 | && sized_sentinel_for<sentinel_t<_Derived>, iterator_t<_Derived>> | |
147 | { return ranges::end(_M_derived()) - ranges::begin(_M_derived()); } | |
148 | ||
149 | constexpr auto | |
150 | size() const | |
151 | requires forward_range<const _Derived> | |
152 | && sized_sentinel_for<sentinel_t<const _Derived>, | |
153 | iterator_t<const _Derived>> | |
154 | { return ranges::end(_M_derived()) - ranges::begin(_M_derived()); } | |
155 | ||
156 | constexpr decltype(auto) | |
157 | front() requires forward_range<_Derived> | |
158 | { | |
159 | __glibcxx_assert(!empty()); | |
160 | return *ranges::begin(_M_derived()); | |
161 | } | |
162 | ||
163 | constexpr decltype(auto) | |
164 | front() const requires forward_range<const _Derived> | |
165 | { | |
166 | __glibcxx_assert(!empty()); | |
167 | return *ranges::begin(_M_derived()); | |
168 | } | |
169 | ||
170 | constexpr decltype(auto) | |
171 | back() | |
172 | requires bidirectional_range<_Derived> && common_range<_Derived> | |
173 | { | |
174 | __glibcxx_assert(!empty()); | |
175 | return *ranges::prev(ranges::end(_M_derived())); | |
176 | } | |
177 | ||
178 | constexpr decltype(auto) | |
179 | back() const | |
180 | requires bidirectional_range<const _Derived> | |
181 | && common_range<const _Derived> | |
182 | { | |
183 | __glibcxx_assert(!empty()); | |
184 | return *ranges::prev(ranges::end(_M_derived())); | |
185 | } | |
186 | ||
187 | template<random_access_range _Range = _Derived> | |
188 | constexpr decltype(auto) | |
189 | operator[](range_difference_t<_Range> __n) | |
190 | { return ranges::begin(_M_derived())[__n]; } | |
191 | ||
192 | template<random_access_range _Range = const _Derived> | |
193 | constexpr decltype(auto) | |
194 | operator[](range_difference_t<_Range> __n) const | |
195 | { return ranges::begin(_M_derived())[__n]; } | |
196 | }; | |
197 | ||
198 | namespace __detail | |
199 | { | |
77f5310f JW |
200 | template<class _From, class _To> |
201 | concept __convertible_to_non_slicing = convertible_to<_From, _To> | |
202 | && !(is_pointer_v<decay_t<_From>> && is_pointer_v<decay_t<_To>> | |
203 | && __not_same_as<remove_pointer_t<decay_t<_From>>, | |
204 | remove_pointer_t<decay_t<_To>>>); | |
205 | ||
37f33df7 JW |
206 | template<typename _Tp> |
207 | concept __pair_like | |
208 | = !is_reference_v<_Tp> && requires(_Tp __t) | |
209 | { | |
210 | typename tuple_size<_Tp>::type; | |
211 | requires derived_from<tuple_size<_Tp>, integral_constant<size_t, 2>>; | |
212 | typename tuple_element_t<0, remove_const_t<_Tp>>; | |
213 | typename tuple_element_t<1, remove_const_t<_Tp>>; | |
214 | { get<0>(__t) } -> convertible_to<const tuple_element_t<0, _Tp>&>; | |
215 | { get<1>(__t) } -> convertible_to<const tuple_element_t<1, _Tp>&>; | |
216 | }; | |
217 | ||
37f33df7 JW |
218 | template<typename _Tp, typename _Up, typename _Vp> |
219 | concept __pair_like_convertible_from | |
220 | = !range<_Tp> && __pair_like<_Tp> | |
77f5310f JW |
221 | && constructible_from<_Tp, _Up, _Vp> |
222 | && __convertible_to_non_slicing<_Up, tuple_element_t<0, _Tp>> | |
223 | && convertible_to<_Vp, tuple_element_t<1, _Tp>>; | |
37f33df7 JW |
224 | |
225 | template<typename _Tp> | |
226 | concept __iterator_sentinel_pair | |
227 | = !range<_Tp> && __pair_like<_Tp> | |
228 | && sentinel_for<tuple_element_t<1, _Tp>, tuple_element_t<0, _Tp>>; | |
229 | ||
37f33df7 JW |
230 | } // namespace __detail |
231 | ||
232 | enum class subrange_kind : bool { unsized, sized }; | |
233 | ||
234 | template<input_or_output_iterator _It, sentinel_for<_It> _Sent = _It, | |
235 | subrange_kind _Kind = sized_sentinel_for<_Sent, _It> | |
236 | ? subrange_kind::sized : subrange_kind::unsized> | |
237 | requires (_Kind == subrange_kind::sized || !sized_sentinel_for<_Sent, _It>) | |
238 | class subrange : public view_interface<subrange<_It, _Sent, _Kind>> | |
239 | { | |
240 | private: | |
cba9ef06 PP |
241 | // XXX: gcc complains when using constexpr here |
242 | static const bool _S_store_size | |
37f33df7 JW |
243 | = _Kind == subrange_kind::sized && !sized_sentinel_for<_Sent, _It>; |
244 | ||
245 | _It _M_begin = _It(); | |
246 | _Sent _M_end = _Sent(); | |
247 | ||
248 | template<typename, bool = _S_store_size> | |
249 | struct _Size | |
250 | { }; | |
251 | ||
252 | template<typename _Tp> | |
253 | struct _Size<_Tp, true> | |
254 | { __detail::__make_unsigned_like_t<_Tp> _M_size; }; | |
255 | ||
256 | [[no_unique_address]] _Size<iter_difference_t<_It>> _M_size = {}; | |
257 | ||
258 | public: | |
259 | subrange() = default; | |
260 | ||
261 | constexpr | |
77f5310f JW |
262 | subrange(__detail::__convertible_to_non_slicing<_It> auto __i, _Sent __s) |
263 | requires (!_S_store_size) | |
37f33df7 JW |
264 | : _M_begin(std::move(__i)), _M_end(__s) |
265 | { } | |
266 | ||
267 | constexpr | |
77f5310f | 268 | subrange(__detail::__convertible_to_non_slicing<_It> auto __i, _Sent __s, |
37f33df7 JW |
269 | __detail::__make_unsigned_like_t<iter_difference_t<_It>> __n) |
270 | requires (_Kind == subrange_kind::sized) | |
271 | : _M_begin(std::move(__i)), _M_end(__s) | |
272 | { | |
273 | using __detail::__to_unsigned_like; | |
274 | __glibcxx_assert(__n == __to_unsigned_like(ranges::distance(__i, __s))); | |
275 | if constexpr (_S_store_size) | |
276 | _M_size._M_size = __n; | |
277 | } | |
278 | ||
279 | template<__detail::__not_same_as<subrange> _Rng> | |
15411a64 | 280 | requires borrowed_range<_Rng> |
77f5310f | 281 | && __detail::__convertible_to_non_slicing<iterator_t<_Rng>, _It> |
37f33df7 JW |
282 | && convertible_to<sentinel_t<_Rng>, _Sent> |
283 | constexpr | |
284 | subrange(_Rng&& __r) requires (!_S_store_size || sized_range<_Rng>) | |
285 | : subrange{ranges::begin(__r), ranges::end(__r)} | |
286 | { | |
287 | if constexpr (_S_store_size) | |
288 | _M_size._M_size = ranges::size(__r); | |
289 | } | |
290 | ||
15411a64 | 291 | template<borrowed_range _Rng> |
77f5310f | 292 | requires __detail::__convertible_to_non_slicing<iterator_t<_Rng>, _It> |
37f33df7 JW |
293 | && convertible_to<sentinel_t<_Rng>, _Sent> |
294 | constexpr | |
295 | subrange(_Rng&& __r, | |
296 | __detail::__make_unsigned_like_t<iter_difference_t<_It>> __n) | |
297 | requires (_Kind == subrange_kind::sized) | |
298 | : subrange{ranges::begin(__r), ranges::end(__r), __n} | |
299 | { } | |
300 | ||
37f33df7 JW |
301 | template<__detail::__not_same_as<subrange> _PairLike> |
302 | requires __detail::__pair_like_convertible_from<_PairLike, const _It&, | |
303 | const _Sent&> | |
304 | constexpr | |
305 | operator _PairLike() const | |
306 | { return _PairLike(_M_begin, _M_end); } | |
307 | ||
308 | constexpr _It | |
309 | begin() const requires copyable<_It> | |
310 | { return _M_begin; } | |
311 | ||
312 | [[nodiscard]] constexpr _It | |
313 | begin() requires (!copyable<_It>) | |
314 | { return std::move(_M_begin); } | |
315 | ||
316 | constexpr _Sent end() const { return _M_end; } | |
317 | ||
318 | constexpr bool empty() const { return _M_begin == _M_end; } | |
319 | ||
320 | constexpr __detail::__make_unsigned_like_t<iter_difference_t<_It>> | |
321 | size() const requires (_Kind == subrange_kind::sized) | |
322 | { | |
323 | if constexpr (_S_store_size) | |
324 | return _M_size._M_size; | |
325 | else | |
326 | return __detail::__to_unsigned_like(_M_end - _M_begin); | |
327 | } | |
328 | ||
329 | [[nodiscard]] constexpr subrange | |
330 | next(iter_difference_t<_It> __n = 1) const & | |
331 | requires forward_iterator<_It> | |
332 | { | |
333 | auto __tmp = *this; | |
334 | __tmp.advance(__n); | |
335 | return __tmp; | |
336 | } | |
337 | ||
338 | [[nodiscard]] constexpr subrange | |
339 | next(iter_difference_t<_It> __n = 1) && | |
340 | { | |
341 | advance(__n); | |
342 | return std::move(*this); | |
343 | } | |
344 | ||
345 | [[nodiscard]] constexpr subrange | |
346 | prev(iter_difference_t<_It> __n = 1) const | |
347 | requires bidirectional_iterator<_It> | |
348 | { | |
349 | auto __tmp = *this; | |
350 | __tmp.advance(--__n); | |
351 | return __tmp; | |
352 | } | |
353 | ||
354 | constexpr subrange& | |
355 | advance(iter_difference_t<_It> __n) | |
356 | { | |
357 | if constexpr (_S_store_size) | |
358 | { | |
359 | auto __d = __n - ranges::advance(_M_begin, __n, _M_end); | |
360 | if (__d >= 0) | |
361 | _M_size._M_size -= __detail::__to_unsigned_like(__d); | |
362 | else | |
363 | _M_size._M_size += __detail::__to_unsigned_like(-__d); | |
364 | } | |
365 | else | |
366 | ranges::advance(_M_begin, __n, _M_end); | |
367 | return *this; | |
368 | } | |
37f33df7 JW |
369 | }; |
370 | ||
371 | template<input_or_output_iterator _It, sentinel_for<_It> _Sent> | |
77f5310f JW |
372 | subrange(_It, _Sent) -> subrange<_It, _Sent>; |
373 | ||
374 | template<input_or_output_iterator _It, sentinel_for<_It> _Sent> | |
37f33df7 JW |
375 | subrange(_It, _Sent, |
376 | __detail::__make_unsigned_like_t<iter_difference_t<_It>>) | |
377 | -> subrange<_It, _Sent, subrange_kind::sized>; | |
378 | ||
379 | template<__detail::__iterator_sentinel_pair _Pr> | |
380 | subrange(_Pr) | |
381 | -> subrange<tuple_element_t<0, _Pr>, tuple_element_t<1, _Pr>>; | |
382 | ||
383 | template<__detail::__iterator_sentinel_pair _Pr> | |
384 | subrange(_Pr, __detail::__make_unsigned_like_t<iter_difference_t< | |
385 | tuple_element_t<0, _Pr>>>) | |
386 | -> subrange<tuple_element_t<0, _Pr>, tuple_element_t<1, _Pr>, | |
387 | subrange_kind::sized>; | |
388 | ||
15411a64 | 389 | template<borrowed_range _Rng> |
37f33df7 JW |
390 | subrange(_Rng&&) |
391 | -> subrange<iterator_t<_Rng>, sentinel_t<_Rng>, | |
392 | (sized_range<_Rng> | |
393 | || sized_sentinel_for<sentinel_t<_Rng>, iterator_t<_Rng>>) | |
394 | ? subrange_kind::sized : subrange_kind::unsized>; | |
395 | ||
15411a64 | 396 | template<borrowed_range _Rng> |
37f33df7 JW |
397 | subrange(_Rng&&, |
398 | __detail::__make_unsigned_like_t<range_difference_t<_Rng>>) | |
399 | -> subrange<iterator_t<_Rng>, sentinel_t<_Rng>, subrange_kind::sized>; | |
400 | ||
401 | template<size_t _Num, class _It, class _Sent, subrange_kind _Kind> | |
402 | requires (_Num < 2) | |
403 | constexpr auto | |
404 | get(const subrange<_It, _Sent, _Kind>& __r) | |
405 | { | |
406 | if constexpr (_Num == 0) | |
407 | return __r.begin(); | |
408 | else | |
409 | return __r.end(); | |
410 | } | |
411 | ||
412 | template<size_t _Num, class _It, class _Sent, subrange_kind _Kind> | |
413 | requires (_Num < 2) | |
414 | constexpr auto | |
415 | get(subrange<_It, _Sent, _Kind>&& __r) | |
416 | { | |
417 | if constexpr (_Num == 0) | |
418 | return __r.begin(); | |
419 | else | |
420 | return __r.end(); | |
421 | } | |
b5b2e387 JW |
422 | |
423 | template<input_or_output_iterator _It, sentinel_for<_It> _Sent, | |
424 | subrange_kind _Kind> | |
425 | inline constexpr bool | |
15411a64 | 426 | enable_borrowed_range<subrange<_It, _Sent, _Kind>> = true; |
b5b2e387 | 427 | |
37f33df7 JW |
428 | } // namespace ranges |
429 | ||
430 | using ranges::get; | |
431 | ||
432 | namespace ranges | |
433 | { | |
434 | /// Type returned by algorithms instead of a dangling iterator or subrange. | |
435 | struct dangling | |
436 | { | |
437 | constexpr dangling() noexcept = default; | |
438 | template<typename... _Args> | |
439 | constexpr dangling(_Args&&...) noexcept { } | |
440 | }; | |
441 | ||
b5b2e387 | 442 | template<range _Range> |
15411a64 JW |
443 | using borrowed_iterator_t = conditional_t<borrowed_range<_Range>, |
444 | iterator_t<_Range>, | |
445 | dangling>; | |
b5b2e387 JW |
446 | |
447 | template<range _Range> | |
15411a64 JW |
448 | using borrowed_subrange_t = conditional_t<borrowed_range<_Range>, |
449 | subrange<iterator_t<_Range>>, | |
450 | dangling>; | |
b5b2e387 | 451 | |
37f33df7 | 452 | template<typename _Tp> requires is_object_v<_Tp> |
b5b2e387 JW |
453 | class empty_view |
454 | : public view_interface<empty_view<_Tp>> | |
37f33df7 JW |
455 | { |
456 | public: | |
457 | static constexpr _Tp* begin() noexcept { return nullptr; } | |
458 | static constexpr _Tp* end() noexcept { return nullptr; } | |
459 | static constexpr _Tp* data() noexcept { return nullptr; } | |
460 | static constexpr size_t size() noexcept { return 0; } | |
461 | static constexpr bool empty() noexcept { return true; } | |
37f33df7 JW |
462 | }; |
463 | ||
b5b2e387 | 464 | template<typename _Tp> |
15411a64 | 465 | inline constexpr bool enable_borrowed_range<empty_view<_Tp>> = true; |
b5b2e387 | 466 | |
37f33df7 JW |
467 | namespace __detail |
468 | { | |
469 | template<copy_constructible _Tp> requires is_object_v<_Tp> | |
470 | struct __box : std::optional<_Tp> | |
471 | { | |
472 | using std::optional<_Tp>::optional; | |
473 | ||
474 | constexpr | |
475 | __box() | |
476 | noexcept(is_nothrow_default_constructible_v<_Tp>) | |
477 | requires default_initializable<_Tp> | |
478 | : std::optional<_Tp>{std::in_place} | |
479 | { } | |
480 | ||
cba9ef06 PP |
481 | __box(const __box&) = default; |
482 | __box(__box&&) = default; | |
483 | ||
37f33df7 JW |
484 | using std::optional<_Tp>::operator=; |
485 | ||
486 | __box& | |
487 | operator=(const __box& __that) | |
488 | noexcept(is_nothrow_copy_constructible_v<_Tp>) | |
489 | requires (!assignable_from<_Tp&, const _Tp&>) | |
490 | { | |
491 | if ((bool)__that) | |
492 | this->emplace(*__that); | |
493 | else | |
494 | this->reset(); | |
495 | return *this; | |
496 | } | |
497 | ||
498 | __box& | |
499 | operator=(__box&& __that) | |
500 | noexcept(is_nothrow_move_constructible_v<_Tp>) | |
501 | requires (!assignable_from<_Tp&, _Tp>) | |
502 | { | |
503 | if ((bool)__that) | |
504 | this->emplace(std::move(*__that)); | |
505 | else | |
506 | this->reset(); | |
507 | return *this; | |
508 | } | |
509 | }; | |
510 | ||
511 | } // namespace __detail | |
512 | ||
513 | /// A view that contains exactly one element. | |
514 | template<copy_constructible _Tp> requires is_object_v<_Tp> | |
515 | class single_view : public view_interface<single_view<_Tp>> | |
516 | { | |
517 | public: | |
518 | single_view() = default; | |
519 | ||
520 | constexpr explicit | |
521 | single_view(const _Tp& __t) | |
522 | : _M_value(__t) | |
523 | { } | |
524 | ||
525 | constexpr explicit | |
526 | single_view(_Tp&& __t) | |
527 | : _M_value(std::move(__t)) | |
528 | { } | |
529 | ||
530 | template<typename... _Args> | |
531 | requires constructible_from<_Tp, _Args...> | |
532 | constexpr | |
533 | single_view(in_place_t, _Args&&... __args) | |
534 | : _M_value{in_place, std::forward<_Args>(__args)...} | |
535 | { } | |
536 | ||
537 | constexpr _Tp* | |
538 | begin() noexcept | |
539 | { return data(); } | |
540 | ||
541 | constexpr const _Tp* | |
542 | begin() const noexcept | |
543 | { return data(); } | |
544 | ||
545 | constexpr _Tp* | |
546 | end() noexcept | |
547 | { return data() + 1; } | |
548 | ||
549 | constexpr const _Tp* | |
550 | end() const noexcept | |
551 | { return data() + 1; } | |
552 | ||
553 | static constexpr size_t | |
554 | size() noexcept | |
555 | { return 1; } | |
556 | ||
557 | constexpr _Tp* | |
558 | data() noexcept | |
559 | { return _M_value.operator->(); } | |
560 | ||
561 | constexpr const _Tp* | |
562 | data() const noexcept | |
563 | { return _M_value.operator->(); } | |
564 | ||
565 | private: | |
566 | __detail::__box<_Tp> _M_value; | |
567 | }; | |
568 | ||
569 | namespace __detail | |
570 | { | |
571 | template<typename _Wp> | |
572 | constexpr auto __to_signed_like(_Wp __w) noexcept | |
573 | { | |
574 | if constexpr (!integral<_Wp>) | |
575 | return iter_difference_t<_Wp>(); | |
576 | else if constexpr (sizeof(iter_difference_t<_Wp>) > sizeof(_Wp)) | |
577 | return iter_difference_t<_Wp>(__w); | |
578 | else if constexpr (sizeof(ptrdiff_t) > sizeof(_Wp)) | |
579 | return ptrdiff_t(__w); | |
580 | else if constexpr (sizeof(long long) > sizeof(_Wp)) | |
581 | return (long long)(__w); | |
582 | #ifdef __SIZEOF_INT128__ | |
583 | else if constexpr (__SIZEOF_INT128__ > sizeof(_Wp)) | |
584 | return __int128(__w); | |
585 | #endif | |
586 | else | |
587 | return __max_diff_type(__w); | |
588 | } | |
589 | ||
590 | template<typename _Wp> | |
591 | using __iota_diff_t = decltype(__to_signed_like(std::declval<_Wp>())); | |
592 | ||
593 | template<typename _It> | |
594 | concept __decrementable = incrementable<_It> | |
595 | && requires(_It __i) | |
596 | { | |
597 | { --__i } -> same_as<_It&>; | |
598 | { __i-- } -> same_as<_It>; | |
599 | }; | |
600 | ||
601 | template<typename _It> | |
602 | concept __advanceable = __decrementable<_It> && totally_ordered<_It> | |
603 | && requires( _It __i, const _It __j, const __iota_diff_t<_It> __n) | |
604 | { | |
605 | { __i += __n } -> same_as<_It&>; | |
606 | { __i -= __n } -> same_as<_It&>; | |
607 | _It(__j + __n); | |
608 | _It(__n + __j); | |
609 | _It(__j - __n); | |
610 | { __j - __j } -> convertible_to<__iota_diff_t<_It>>; | |
611 | }; | |
612 | ||
613 | } // namespace __detail | |
614 | ||
615 | template<weakly_incrementable _Winc, | |
616 | semiregular _Bound = unreachable_sentinel_t> | |
617 | requires std::__detail::__weakly_eq_cmp_with<_Winc, _Bound> | |
7f0f1083 | 618 | && semiregular<_Winc> |
37f33df7 JW |
619 | class iota_view : public view_interface<iota_view<_Winc, _Bound>> |
620 | { | |
621 | private: | |
5586e506 PP |
622 | struct _Sentinel; |
623 | ||
37f33df7 JW |
624 | struct _Iterator |
625 | { | |
626 | private: | |
627 | static auto | |
628 | _S_iter_cat() | |
629 | { | |
630 | using namespace __detail; | |
631 | if constexpr (__advanceable<_Winc>) | |
632 | return random_access_iterator_tag{}; | |
633 | else if constexpr (__decrementable<_Winc>) | |
634 | return bidirectional_iterator_tag{}; | |
635 | else if constexpr (incrementable<_Winc>) | |
636 | return forward_iterator_tag{}; | |
637 | else | |
638 | return input_iterator_tag{}; | |
639 | } | |
640 | ||
641 | public: | |
642 | using iterator_category = decltype(_S_iter_cat()); | |
643 | using value_type = _Winc; | |
644 | using difference_type = __detail::__iota_diff_t<_Winc>; | |
645 | ||
646 | _Iterator() = default; | |
647 | ||
648 | constexpr explicit | |
649 | _Iterator(_Winc __value) | |
650 | : _M_value(__value) { } | |
651 | ||
652 | constexpr _Winc | |
653 | operator*() const noexcept(is_nothrow_copy_constructible_v<_Winc>) | |
654 | { return _M_value; } | |
655 | ||
656 | constexpr _Iterator& | |
657 | operator++() | |
658 | { | |
659 | ++_M_value; | |
660 | return *this; | |
661 | } | |
662 | ||
663 | constexpr void | |
664 | operator++(int) | |
665 | { ++*this; } | |
666 | ||
667 | constexpr _Iterator | |
668 | operator++(int) requires incrementable<_Winc> | |
669 | { | |
670 | auto __tmp = *this; | |
671 | ++*this; | |
672 | return __tmp; | |
673 | } | |
674 | ||
675 | constexpr _Iterator& | |
676 | operator--() requires __detail::__decrementable<_Winc> | |
677 | { | |
678 | --_M_value; | |
679 | return *this; | |
680 | } | |
681 | ||
682 | constexpr _Iterator | |
683 | operator--(int) requires __detail::__decrementable<_Winc> | |
684 | { | |
685 | auto __tmp = *this; | |
686 | --*this; | |
687 | return __tmp; | |
688 | } | |
689 | ||
690 | constexpr _Iterator& | |
691 | operator+=(difference_type __n) requires __detail::__advanceable<_Winc> | |
692 | { | |
2a0f6c61 JW |
693 | using __detail::__is_integer_like; |
694 | using __detail::__is_signed_integer_like; | |
37f33df7 JW |
695 | if constexpr (__is_integer_like<_Winc> |
696 | && !__is_signed_integer_like<_Winc>) | |
697 | { | |
698 | if (__n >= difference_type(0)) | |
699 | _M_value += static_cast<_Winc>(__n); | |
700 | else | |
701 | _M_value -= static_cast<_Winc>(-__n); | |
702 | } | |
703 | else | |
704 | _M_value += __n; | |
705 | return *this; | |
706 | } | |
707 | ||
708 | constexpr _Iterator& | |
709 | operator-=(difference_type __n) requires __detail::__advanceable<_Winc> | |
710 | { | |
2a0f6c61 JW |
711 | using __detail::__is_integer_like; |
712 | using __detail::__is_signed_integer_like; | |
37f33df7 JW |
713 | if constexpr (__is_integer_like<_Winc> |
714 | && !__is_signed_integer_like<_Winc>) | |
715 | { | |
716 | if (__n >= difference_type(0)) | |
717 | _M_value -= static_cast<_Winc>(__n); | |
718 | else | |
719 | _M_value += static_cast<_Winc>(-__n); | |
720 | } | |
721 | else | |
722 | _M_value -= __n; | |
723 | return *this; | |
724 | } | |
725 | ||
726 | constexpr _Winc | |
727 | operator[](difference_type __n) const | |
728 | requires __detail::__advanceable<_Winc> | |
729 | { return _Winc(_M_value + __n); } | |
730 | ||
731 | friend constexpr bool | |
732 | operator==(const _Iterator& __x, const _Iterator& __y) | |
733 | requires equality_comparable<_Winc> | |
734 | { return __x._M_value == __y._M_value; } | |
735 | ||
736 | friend constexpr bool | |
737 | operator<(const _Iterator& __x, const _Iterator& __y) | |
738 | requires totally_ordered<_Winc> | |
739 | { return __x._M_value < __y._M_value; } | |
740 | ||
741 | friend constexpr bool | |
742 | operator>(const _Iterator& __x, const _Iterator& __y) | |
743 | requires totally_ordered<_Winc> | |
744 | { return __y < __x; } | |
745 | ||
746 | friend constexpr bool | |
747 | operator<=(const _Iterator& __x, const _Iterator& __y) | |
748 | requires totally_ordered<_Winc> | |
749 | { return !(__y < __x); } | |
750 | ||
751 | friend constexpr bool | |
752 | operator>=(const _Iterator& __x, const _Iterator& __y) | |
753 | requires totally_ordered<_Winc> | |
754 | { return !(__x < __y); } | |
755 | ||
5713834e JW |
756 | #ifdef __cpp_lib_three_way_comparison |
757 | friend constexpr auto | |
37f33df7 JW |
758 | operator<=>(const _Iterator& __x, const _Iterator& __y) |
759 | requires totally_ordered<_Winc> && three_way_comparable<_Winc> | |
760 | { return __x._M_value <=> __y._M_value; } | |
761 | #endif | |
762 | ||
763 | friend constexpr _Iterator | |
764 | operator+(_Iterator __i, difference_type __n) | |
765 | requires __detail::__advanceable<_Winc> | |
766 | { return __i += __n; } | |
767 | ||
768 | friend constexpr _Iterator | |
769 | operator+(difference_type __n, _Iterator __i) | |
770 | requires __detail::__advanceable<_Winc> | |
771 | { return __i += __n; } | |
772 | ||
773 | friend constexpr _Iterator | |
774 | operator-(_Iterator __i, difference_type __n) | |
775 | requires __detail::__advanceable<_Winc> | |
776 | { return __i -= __n; } | |
777 | ||
778 | friend constexpr difference_type | |
779 | operator-(const _Iterator& __x, const _Iterator& __y) | |
780 | requires __detail::__advanceable<_Winc> | |
781 | { | |
2a0f6c61 JW |
782 | using __detail::__is_integer_like; |
783 | using __detail::__is_signed_integer_like; | |
37f33df7 JW |
784 | using _Dt = difference_type; |
785 | if constexpr (__is_integer_like<_Winc>) | |
786 | { | |
787 | if constexpr (__is_signed_integer_like<_Winc>) | |
788 | return _Dt(_Dt(__x._M_value) - _Dt(__y._M_value)); | |
789 | else | |
790 | return (__y._M_value > __x._M_value) | |
791 | ? _Dt(-_Dt(__y._M_value - __x._M_value)) | |
792 | : _Dt(__x._M_value - __y._M_value); | |
793 | } | |
794 | else | |
795 | return __x._M_value - __y._M_value; | |
796 | } | |
797 | ||
798 | private: | |
799 | _Winc _M_value = _Winc(); | |
5586e506 PP |
800 | |
801 | friend _Sentinel; | |
37f33df7 JW |
802 | }; |
803 | ||
804 | struct _Sentinel | |
805 | { | |
806 | private: | |
5586e506 PP |
807 | constexpr bool |
808 | _M_equal(const _Iterator& __x) const | |
809 | { return __x._M_value == _M_bound; } | |
810 | ||
37f33df7 JW |
811 | _Bound _M_bound = _Bound(); |
812 | ||
813 | public: | |
814 | _Sentinel() = default; | |
815 | ||
816 | constexpr explicit | |
817 | _Sentinel(_Bound __bound) | |
818 | : _M_bound(__bound) { } | |
819 | ||
820 | friend constexpr bool | |
821 | operator==(const _Iterator& __x, const _Sentinel& __y) | |
5586e506 | 822 | { return __y._M_equal(__x); } |
37f33df7 JW |
823 | |
824 | friend constexpr iter_difference_t<_Winc> | |
825 | operator-(const _Iterator& __x, const _Sentinel& __y) | |
826 | requires sized_sentinel_for<_Bound, _Winc> | |
827 | { return __x._M_value - __y._M_bound; } | |
828 | ||
829 | friend constexpr iter_difference_t<_Winc> | |
830 | operator-(const _Sentinel& __x, const _Iterator& __y) | |
831 | requires sized_sentinel_for<_Bound, _Winc> | |
832 | { return -(__y - __x); } | |
833 | }; | |
834 | ||
835 | _Winc _M_value = _Winc(); | |
836 | _Bound _M_bound = _Bound(); | |
837 | ||
838 | public: | |
839 | iota_view() = default; | |
840 | ||
841 | constexpr explicit | |
842 | iota_view(_Winc __value) | |
843 | : _M_value(__value) | |
844 | { } | |
845 | ||
846 | constexpr | |
847 | iota_view(type_identity_t<_Winc> __value, | |
848 | type_identity_t<_Bound> __bound) | |
849 | : _M_value(__value), _M_bound(__bound) | |
850 | { | |
851 | if constexpr (totally_ordered_with<_Winc, _Bound>) | |
572992c8 JW |
852 | { |
853 | __glibcxx_assert( bool(__value <= __bound) ); | |
854 | } | |
37f33df7 JW |
855 | } |
856 | ||
857 | constexpr _Iterator | |
858 | begin() const { return _Iterator{_M_value}; } | |
859 | ||
860 | constexpr auto | |
861 | end() const | |
862 | { | |
863 | if constexpr (same_as<_Bound, unreachable_sentinel_t>) | |
864 | return unreachable_sentinel; | |
865 | else | |
866 | return _Sentinel{_M_bound}; | |
867 | } | |
868 | ||
869 | constexpr _Iterator | |
870 | end() const requires same_as<_Winc, _Bound> | |
871 | { return _Iterator{_M_bound}; } | |
872 | ||
873 | constexpr auto | |
874 | size() const | |
875 | requires (same_as<_Winc, _Bound> && __detail::__advanceable<_Winc>) | |
876 | || (integral<_Winc> && integral<_Bound>) | |
877 | || sized_sentinel_for<_Bound, _Winc> | |
878 | { | |
2a0f6c61 JW |
879 | using __detail::__is_integer_like; |
880 | using __detail::__to_unsigned_like; | |
37f33df7 JW |
881 | if constexpr (__is_integer_like<_Winc> && __is_integer_like<_Bound>) |
882 | return (_M_value < 0) | |
883 | ? ((_M_bound < 0) | |
884 | ? __to_unsigned_like(-_M_value) - __to_unsigned_like(-_M_bound) | |
885 | : __to_unsigned_like(_M_bound) + __to_unsigned_like(-_M_value)) | |
886 | : __to_unsigned_like(_M_bound) - __to_unsigned_like(_M_value); | |
887 | else | |
888 | return __to_unsigned_like(_M_bound - _M_value); | |
889 | } | |
890 | }; | |
891 | ||
892 | template<typename _Winc, typename _Bound> | |
893 | requires (!__detail::__is_integer_like<_Winc> | |
894 | || !__detail::__is_integer_like<_Bound> | |
895 | || (__detail::__is_signed_integer_like<_Winc> | |
896 | == __detail::__is_signed_integer_like<_Bound>)) | |
897 | iota_view(_Winc, _Bound) -> iota_view<_Winc, _Bound>; | |
898 | ||
b5b2e387 | 899 | template<weakly_incrementable _Winc, semiregular _Bound> |
15411a64 JW |
900 | inline constexpr bool |
901 | enable_borrowed_range<iota_view<_Winc, _Bound>> = true; | |
b5b2e387 | 902 | |
37f33df7 JW |
903 | namespace views |
904 | { | |
905 | template<typename _Tp> | |
906 | inline constexpr empty_view<_Tp> empty{}; | |
907 | ||
908 | struct _Single | |
909 | { | |
910 | template<typename _Tp> | |
cba9ef06 | 911 | constexpr auto |
37f33df7 JW |
912 | operator()(_Tp&& __e) const |
913 | { return single_view{std::forward<_Tp>(__e)}; } | |
914 | }; | |
915 | ||
916 | inline constexpr _Single single{}; | |
917 | ||
918 | struct _Iota | |
919 | { | |
920 | template<typename _Tp> | |
cba9ef06 | 921 | constexpr auto |
37f33df7 JW |
922 | operator()(_Tp&& __e) const |
923 | { return iota_view{std::forward<_Tp>(__e)}; } | |
924 | ||
925 | template<typename _Tp, typename _Up> | |
cba9ef06 | 926 | constexpr auto |
37f33df7 | 927 | operator()(_Tp&& __e, _Up&& __f) const |
5586e506 | 928 | { return iota_view{std::forward<_Tp>(__e), std::forward<_Up>(__f)}; } |
37f33df7 JW |
929 | }; |
930 | ||
931 | inline constexpr _Iota iota{}; | |
cba9ef06 PP |
932 | } // namespace views |
933 | ||
b7903d9f PP |
934 | namespace __detail |
935 | { | |
936 | template<typename _Val, typename _CharT, typename _Traits> | |
937 | concept __stream_extractable | |
938 | = requires(basic_istream<_CharT, _Traits>& is, _Val& t) { is >> t; }; | |
939 | } // namespace __detail | |
940 | ||
941 | template<movable _Val, typename _CharT, typename _Traits> | |
942 | requires default_initializable<_Val> | |
943 | && __detail::__stream_extractable<_Val, _CharT, _Traits> | |
944 | class basic_istream_view | |
945 | : public view_interface<basic_istream_view<_Val, _CharT, _Traits>> | |
946 | { | |
947 | public: | |
948 | basic_istream_view() = default; | |
949 | ||
950 | constexpr explicit | |
951 | basic_istream_view(basic_istream<_CharT, _Traits>& __stream) | |
952 | : _M_stream(std::__addressof(__stream)) | |
953 | { } | |
954 | ||
955 | constexpr auto | |
956 | begin() | |
957 | { | |
958 | if (_M_stream != nullptr) | |
959 | *_M_stream >> _M_object; | |
960 | return _Iterator{*this}; | |
961 | } | |
962 | ||
963 | constexpr default_sentinel_t | |
964 | end() const noexcept | |
965 | { return default_sentinel; } | |
966 | ||
967 | private: | |
968 | basic_istream<_CharT, _Traits>* _M_stream = nullptr; | |
969 | _Val _M_object = _Val(); | |
970 | ||
971 | struct _Iterator | |
972 | { | |
973 | public: | |
76a8c0f6 | 974 | using iterator_concept = input_iterator_tag; |
b7903d9f PP |
975 | using difference_type = ptrdiff_t; |
976 | using value_type = _Val; | |
977 | ||
978 | _Iterator() = default; | |
979 | ||
980 | constexpr explicit | |
981 | _Iterator(basic_istream_view& __parent) noexcept | |
982 | : _M_parent(std::__addressof(__parent)) | |
983 | { } | |
984 | ||
985 | _Iterator(const _Iterator&) = delete; | |
986 | _Iterator(_Iterator&&) = default; | |
987 | _Iterator& operator=(const _Iterator&) = delete; | |
988 | _Iterator& operator=(_Iterator&&) = default; | |
989 | ||
990 | _Iterator& | |
991 | operator++() | |
992 | { | |
993 | __glibcxx_assert(_M_parent->_M_stream != nullptr); | |
994 | *_M_parent->_M_stream >> _M_parent->_M_object; | |
572992c8 | 995 | return *this; |
b7903d9f PP |
996 | } |
997 | ||
998 | void | |
999 | operator++(int) | |
1000 | { ++*this; } | |
1001 | ||
1002 | _Val& | |
1003 | operator*() const | |
1004 | { | |
1005 | __glibcxx_assert(_M_parent->_M_stream != nullptr); | |
1006 | return _M_parent->_M_object; | |
1007 | } | |
1008 | ||
1009 | friend bool | |
1010 | operator==(const _Iterator& __x, default_sentinel_t) | |
1011 | { return __x._M_at_end(); } | |
1012 | ||
1013 | private: | |
1014 | basic_istream_view* _M_parent = nullptr; | |
1015 | ||
1016 | bool | |
1017 | _M_at_end() const | |
1018 | { return _M_parent == nullptr || !*_M_parent->_M_stream; } | |
1019 | }; | |
1020 | ||
1021 | friend _Iterator; | |
1022 | }; | |
1023 | ||
1024 | template<typename _Val, typename _CharT, typename _Traits> | |
1025 | basic_istream_view<_Val, _CharT, _Traits> | |
1026 | istream_view(basic_istream<_CharT, _Traits>& __s) | |
1027 | { return basic_istream_view<_Val, _CharT, _Traits>{__s}; } | |
1028 | ||
cba9ef06 PP |
1029 | namespace __detail |
1030 | { | |
1031 | struct _Empty { }; | |
8017d95c JW |
1032 | |
1033 | template<bool _NonEmpty, typename _Tp> | |
1034 | using __maybe_empty_t = conditional_t<_NonEmpty, _Tp, _Empty>; | |
1035 | ||
1036 | template<bool _Const, typename _Tp> | |
1037 | using __maybe_const_t = conditional_t<_Const, const _Tp, _Tp>; | |
1038 | ||
cba9ef06 PP |
1039 | } // namespace __detail |
1040 | ||
1041 | namespace views | |
1042 | { | |
1043 | namespace __adaptor | |
1044 | { | |
6e63438a PP |
1045 | template<typename _Tp> |
1046 | inline constexpr auto | |
1047 | __maybe_refwrap(_Tp& __arg) | |
1048 | { return reference_wrapper<_Tp>{__arg}; } | |
1049 | ||
1050 | template<typename _Tp> | |
1051 | inline constexpr auto | |
1052 | __maybe_refwrap(const _Tp& __arg) | |
1053 | { return reference_wrapper<const _Tp>{__arg}; } | |
1054 | ||
1055 | template<typename _Tp> | |
1056 | inline constexpr decltype(auto) | |
1057 | __maybe_refwrap(_Tp&& __arg) | |
1058 | { return std::forward<_Tp>(__arg); } | |
1059 | ||
cba9ef06 PP |
1060 | template<typename _Callable> |
1061 | struct _RangeAdaptorClosure; | |
1062 | ||
1063 | template<typename _Callable> | |
1064 | struct _RangeAdaptor | |
1065 | { | |
1066 | protected: | |
1067 | [[no_unique_address]] | |
8017d95c JW |
1068 | __detail::__maybe_empty_t<!is_default_constructible_v<_Callable>, |
1069 | _Callable> _M_callable; | |
cba9ef06 PP |
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 | { | |
6e63438a PP |
1088 | // [range.adaptor.object]: If a range adaptor object accepts more |
1089 | // than one argument, then the following expressions are equivalent: | |
1090 | // | |
1091 | // (1) adaptor(range, args...) | |
1092 | // (2) adaptor(args...)(range) | |
1093 | // (3) range | adaptor(args...) | |
1094 | // | |
1095 | // In this case, adaptor(args...) is a range adaptor closure object. | |
1096 | // | |
1097 | // We handle (1) and (2) here, and (3) is just a special case of a | |
1098 | // more general case already handled by _RangeAdaptorClosure. | |
cba9ef06 PP |
1099 | if constexpr (is_invocable_v<_Callable, _Args...>) |
1100 | { | |
1101 | static_assert(sizeof...(_Args) != 1, | |
1102 | "a _RangeAdaptor that accepts only one argument " | |
1103 | "should be defined as a _RangeAdaptorClosure"); | |
6e63438a PP |
1104 | // Here we handle adaptor(range, args...) -- just forward all |
1105 | // arguments to the underlying adaptor routine. | |
cba9ef06 PP |
1106 | return _Callable{}(std::forward<_Args>(__args)...); |
1107 | } | |
1108 | else | |
1109 | { | |
6e63438a PP |
1110 | // Here we handle adaptor(args...)(range). |
1111 | // Given args..., we return a _RangeAdaptorClosure that takes a | |
1112 | // range argument, such that (2) is equivalent to (1). | |
1113 | // | |
1114 | // We need to be careful about how we capture args... in this | |
1115 | // closure. By using __maybe_refwrap, we capture lvalue | |
1116 | // references by reference (through a reference_wrapper) and | |
1117 | // otherwise capture by value. | |
1118 | auto __closure | |
1119 | = [...__args(__maybe_refwrap(std::forward<_Args>(__args)))] | |
1120 | <typename _Range> (_Range&& __r) { | |
1121 | // This static_cast has two purposes: it forwards a | |
1122 | // reference_wrapper<T> capture as a T&, and otherwise | |
1123 | // forwards the captured argument as an rvalue. | |
1124 | return _Callable{}(std::forward<_Range>(__r), | |
1125 | (static_cast<unwrap_reference_t | |
1126 | <remove_const_t<decltype(__args)>>> | |
1127 | (__args))...); | |
1128 | }; | |
cba9ef06 PP |
1129 | using _ClosureType = decltype(__closure); |
1130 | return _RangeAdaptorClosure<_ClosureType>(std::move(__closure)); | |
1131 | } | |
1132 | } | |
1133 | }; | |
1134 | ||
a5b213dd JW |
1135 | template<typename _Callable> |
1136 | _RangeAdaptor(_Callable) -> _RangeAdaptor<_Callable>; | |
1137 | ||
cba9ef06 PP |
1138 | template<typename _Callable> |
1139 | struct _RangeAdaptorClosure : public _RangeAdaptor<_Callable> | |
1140 | { | |
1141 | using _RangeAdaptor<_Callable>::_RangeAdaptor; | |
1142 | ||
1143 | template<viewable_range _Range> | |
1144 | requires requires { declval<_Callable>()(declval<_Range>()); } | |
1145 | constexpr auto | |
1146 | operator()(_Range&& __r) const | |
1147 | { | |
1148 | if constexpr (is_default_constructible_v<_Callable>) | |
1149 | return _Callable{}(std::forward<_Range>(__r)); | |
1150 | else | |
1151 | return this->_M_callable(std::forward<_Range>(__r)); | |
1152 | } | |
1153 | ||
1154 | template<viewable_range _Range> | |
1155 | requires requires { declval<_Callable>()(declval<_Range>()); } | |
1156 | friend constexpr auto | |
1157 | operator|(_Range&& __r, const _RangeAdaptorClosure& __o) | |
1158 | { return __o(std::forward<_Range>(__r)); } | |
37f33df7 | 1159 | |
cba9ef06 PP |
1160 | template<typename _Tp> |
1161 | friend constexpr auto | |
1162 | operator|(const _RangeAdaptorClosure<_Tp>& __x, | |
1163 | const _RangeAdaptorClosure& __y) | |
1164 | { | |
1165 | if constexpr (is_default_constructible_v<_Tp> | |
1166 | && is_default_constructible_v<_Callable>) | |
1167 | { | |
1168 | auto __closure = [] <typename _Up> (_Up&& __e) { | |
1169 | return std::forward<_Up>(__e) | decltype(__x){} | decltype(__y){}; | |
1170 | }; | |
1171 | return _RangeAdaptorClosure<decltype(__closure)>(__closure); | |
1172 | } | |
1173 | else if constexpr (is_default_constructible_v<_Tp> | |
1174 | && !is_default_constructible_v<_Callable>) | |
1175 | { | |
1176 | auto __closure = [__y] <typename _Up> (_Up&& __e) { | |
1177 | return std::forward<_Up>(__e) | decltype(__x){} | __y; | |
1178 | }; | |
1179 | return _RangeAdaptorClosure<decltype(__closure)>(__closure); | |
1180 | } | |
1181 | else if constexpr (!is_default_constructible_v<_Tp> | |
1182 | && is_default_constructible_v<_Callable>) | |
1183 | { | |
1184 | auto __closure = [__x] <typename _Up> (_Up&& __e) { | |
1185 | return std::forward<_Up>(__e) | __x | decltype(__y){}; | |
1186 | }; | |
1187 | return _RangeAdaptorClosure<decltype(__closure)>(__closure); | |
1188 | } | |
1189 | else | |
1190 | { | |
1191 | auto __closure = [__x, __y] <typename _Up> (_Up&& __e) { | |
1192 | return std::forward<_Up>(__e) | __x | __y; | |
1193 | }; | |
1194 | return _RangeAdaptorClosure<decltype(__closure)>(__closure); | |
1195 | } | |
1196 | } | |
1197 | }; | |
1198 | ||
1199 | template<typename _Callable> | |
1200 | _RangeAdaptorClosure(_Callable) -> _RangeAdaptorClosure<_Callable>; | |
1201 | } // namespace __adaptor | |
37f33df7 | 1202 | } // namespace views |
cba9ef06 PP |
1203 | |
1204 | template<range _Range> requires is_object_v<_Range> | |
1205 | class ref_view : public view_interface<ref_view<_Range>> | |
1206 | { | |
1207 | private: | |
1208 | _Range* _M_r = nullptr; | |
1209 | ||
1210 | static void _S_fun(_Range&); // not defined | |
1211 | static void _S_fun(_Range&&) = delete; | |
1212 | ||
1213 | public: | |
1214 | constexpr | |
1215 | ref_view() noexcept = default; | |
1216 | ||
1217 | template<__detail::__not_same_as<ref_view> _Tp> | |
1218 | requires convertible_to<_Tp, _Range&> | |
1219 | && requires { _S_fun(declval<_Tp>()); } | |
1220 | constexpr | |
1221 | ref_view(_Tp&& __t) | |
1222 | : _M_r(std::__addressof(static_cast<_Range&>(std::forward<_Tp>(__t)))) | |
1223 | { } | |
1224 | ||
1225 | constexpr _Range& | |
1226 | base() const | |
1227 | { return *_M_r; } | |
1228 | ||
1229 | constexpr iterator_t<_Range> | |
1230 | begin() const | |
1231 | { return ranges::begin(*_M_r); } | |
1232 | ||
1233 | constexpr sentinel_t<_Range> | |
1234 | end() const | |
1235 | { return ranges::end(*_M_r); } | |
1236 | ||
1237 | constexpr bool | |
1238 | empty() const requires requires { ranges::empty(*_M_r); } | |
1239 | { return ranges::empty(*_M_r); } | |
1240 | ||
1241 | constexpr auto | |
1242 | size() const requires sized_range<_Range> | |
1243 | { return ranges::size(*_M_r); } | |
1244 | ||
1245 | constexpr auto | |
1246 | data() const requires contiguous_range<_Range> | |
1247 | { return ranges::data(*_M_r); } | |
1248 | }; | |
1249 | ||
1250 | template<typename _Range> | |
1251 | ref_view(_Range&) -> ref_view<_Range>; | |
1252 | ||
1253 | template<typename _Tp> | |
15411a64 | 1254 | inline constexpr bool enable_borrowed_range<ref_view<_Tp>> = true; |
cba9ef06 PP |
1255 | |
1256 | namespace views | |
1257 | { | |
1258 | inline constexpr __adaptor::_RangeAdaptorClosure all | |
1259 | = [] <viewable_range _Range> (_Range&& __r) | |
1260 | { | |
1261 | if constexpr (view<decay_t<_Range>>) | |
1262 | return std::forward<_Range>(__r); | |
1263 | else if constexpr (requires { ref_view{std::forward<_Range>(__r)}; }) | |
1264 | return ref_view{std::forward<_Range>(__r)}; | |
1265 | else | |
1266 | return subrange{std::forward<_Range>(__r)}; | |
1267 | }; | |
cba9ef06 | 1268 | |
aca60ecf JW |
1269 | template<viewable_range _Range> |
1270 | using all_t = decltype(all(std::declval<_Range>())); | |
1271 | ||
1272 | } // namespace views | |
cba9ef06 PP |
1273 | |
1274 | // XXX: the following algos are copied from ranges_algo.h to avoid a circular | |
1275 | // dependency with that header. | |
1276 | namespace __detail | |
1277 | { | |
1278 | template<input_iterator _Iter, sentinel_for<_Iter> _Sent, | |
1279 | typename _Proj = identity, | |
1280 | indirect_unary_predicate<projected<_Iter, _Proj>> _Pred> | |
1281 | constexpr _Iter | |
1282 | find_if(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) | |
1283 | { | |
1284 | while (__first != __last | |
1285 | && !(bool)std::__invoke(__pred, std::__invoke(__proj, *__first))) | |
1286 | ++__first; | |
1287 | return __first; | |
1288 | } | |
1289 | ||
1290 | template<input_iterator _Iter, sentinel_for<_Iter> _Sent, | |
1291 | typename _Proj = identity, | |
1292 | indirect_unary_predicate<projected<_Iter, _Proj>> _Pred> | |
1293 | constexpr _Iter | |
1294 | find_if_not(_Iter __first, _Sent __last, _Pred __pred, _Proj __proj = {}) | |
1295 | { | |
1296 | while (__first != __last | |
1297 | && (bool)std::__invoke(__pred, std::__invoke(__proj, *__first))) | |
1298 | ++__first; | |
1299 | return __first; | |
1300 | } | |
1301 | ||
1302 | template<typename _Tp, typename _Proj = identity, | |
1303 | indirect_strict_weak_order<projected<const _Tp*, _Proj>> | |
1304 | _Comp = ranges::less> | |
1305 | constexpr const _Tp& | |
1306 | min(const _Tp& __a, const _Tp& __b, _Comp __comp = {}, _Proj __proj = {}) | |
1307 | { | |
1308 | if (std::__invoke(std::move(__comp), | |
1309 | std::__invoke(__proj, __b), | |
1310 | std::__invoke(__proj, __a))) | |
1311 | return __b; | |
1312 | else | |
1313 | return __a; | |
1314 | } | |
1315 | ||
1316 | template<input_iterator _Iter1, sentinel_for<_Iter1> _Sent1, | |
1317 | input_iterator _Iter2, sentinel_for<_Iter2> _Sent2, | |
1318 | typename _Pred = ranges::equal_to, | |
1319 | typename _Proj1 = identity, typename _Proj2 = identity> | |
1320 | requires indirectly_comparable<_Iter1, _Iter2, _Pred, _Proj1, _Proj2> | |
1321 | constexpr pair<_Iter1, _Iter2> | |
1322 | mismatch(_Iter1 __first1, _Sent1 __last1, _Iter2 __first2, _Sent2 __last2, | |
1323 | _Pred __pred = {}, _Proj1 __proj1 = {}, _Proj2 __proj2 = {}) | |
1324 | { | |
1325 | while (__first1 != __last1 && __first2 != __last2 | |
1326 | && (bool)std::__invoke(__pred, | |
1327 | std::__invoke(__proj1, *__first1), | |
1328 | std::__invoke(__proj2, *__first2))) | |
1329 | { | |
1330 | ++__first1; | |
1331 | ++__first2; | |
1332 | } | |
1333 | return { std::move(__first1), std::move(__first2) }; | |
1334 | } | |
1335 | } // namespace __detail | |
1336 | ||
1337 | template<input_range _Vp, | |
1338 | indirect_unary_predicate<iterator_t<_Vp>> _Pred> | |
1339 | requires view<_Vp> && is_object_v<_Pred> | |
1340 | class filter_view : public view_interface<filter_view<_Vp, _Pred>> | |
1341 | { | |
1342 | private: | |
1343 | struct _Sentinel; | |
1344 | ||
1345 | struct _Iterator | |
1346 | { | |
1347 | private: | |
1348 | static constexpr auto | |
1349 | _S_iter_concept() | |
1350 | { | |
1351 | if constexpr (bidirectional_range<_Vp>) | |
1352 | return bidirectional_iterator_tag{}; | |
1353 | else if constexpr (forward_range<_Vp>) | |
1354 | return forward_iterator_tag{}; | |
1355 | else | |
1356 | return input_iterator_tag{}; | |
1357 | } | |
1358 | ||
1359 | static constexpr auto | |
1360 | _S_iter_cat() | |
1361 | { | |
a5b213dd | 1362 | using _Cat = typename iterator_traits<_Vp_iter>::iterator_category; |
cba9ef06 PP |
1363 | if constexpr (derived_from<_Cat, bidirectional_iterator_tag>) |
1364 | return bidirectional_iterator_tag{}; | |
1365 | else if constexpr (derived_from<_Cat, forward_iterator_tag>) | |
1366 | return forward_iterator_tag{}; | |
1367 | else | |
1368 | return _Cat{}; | |
1369 | } | |
1370 | ||
1371 | friend filter_view; | |
1372 | ||
a5b213dd JW |
1373 | using _Vp_iter = iterator_t<_Vp>; |
1374 | ||
1375 | _Vp_iter _M_current = _Vp_iter(); | |
cba9ef06 PP |
1376 | filter_view* _M_parent = nullptr; |
1377 | ||
1378 | public: | |
1379 | using iterator_concept = decltype(_S_iter_concept()); | |
1380 | using iterator_category = decltype(_S_iter_cat()); | |
1381 | using value_type = range_value_t<_Vp>; | |
1382 | using difference_type = range_difference_t<_Vp>; | |
1383 | ||
1384 | _Iterator() = default; | |
1385 | ||
1386 | constexpr | |
a5b213dd | 1387 | _Iterator(filter_view& __parent, _Vp_iter __current) |
cba9ef06 PP |
1388 | : _M_current(std::move(__current)), |
1389 | _M_parent(std::__addressof(__parent)) | |
1390 | { } | |
1391 | ||
a5b213dd | 1392 | constexpr _Vp_iter |
cba9ef06 | 1393 | base() const & |
a5b213dd | 1394 | requires copyable<_Vp_iter> |
cba9ef06 PP |
1395 | { return _M_current; } |
1396 | ||
a5b213dd | 1397 | constexpr _Vp_iter |
cba9ef06 PP |
1398 | base() && |
1399 | { return std::move(_M_current); } | |
1400 | ||
1401 | constexpr range_reference_t<_Vp> | |
1402 | operator*() const | |
1403 | { return *_M_current; } | |
1404 | ||
a5b213dd | 1405 | constexpr _Vp_iter |
cba9ef06 | 1406 | operator->() const |
a5b213dd JW |
1407 | requires __detail::__has_arrow<_Vp_iter> |
1408 | && copyable<_Vp_iter> | |
cba9ef06 PP |
1409 | { return _M_current; } |
1410 | ||
1411 | constexpr _Iterator& | |
1412 | operator++() | |
1413 | { | |
1414 | _M_current = __detail::find_if(std::move(++_M_current), | |
1415 | ranges::end(_M_parent->_M_base), | |
1416 | std::ref(*_M_parent->_M_pred)); | |
1417 | return *this; | |
1418 | } | |
1419 | ||
1420 | constexpr void | |
1421 | operator++(int) | |
1422 | { ++*this; } | |
1423 | ||
1424 | constexpr _Iterator | |
1425 | operator++(int) requires forward_range<_Vp> | |
1426 | { | |
1427 | auto __tmp = *this; | |
1428 | ++*this; | |
1429 | return __tmp; | |
1430 | } | |
1431 | ||
1432 | constexpr _Iterator& | |
1433 | operator--() requires bidirectional_range<_Vp> | |
1434 | { | |
1435 | do | |
1436 | --_M_current; | |
1437 | while (!std::__invoke(*_M_parent->_M_pred, *_M_current)); | |
1438 | return *this; | |
1439 | } | |
1440 | ||
1441 | constexpr _Iterator | |
1442 | operator--(int) requires bidirectional_range<_Vp> | |
1443 | { | |
1444 | auto __tmp = *this; | |
1445 | --*this; | |
1446 | return __tmp; | |
1447 | } | |
1448 | ||
1449 | friend constexpr bool | |
1450 | operator==(const _Iterator& __x, const _Iterator& __y) | |
a5b213dd | 1451 | requires equality_comparable<_Vp_iter> |
cba9ef06 PP |
1452 | { return __x._M_current == __y._M_current; } |
1453 | ||
1454 | friend constexpr range_rvalue_reference_t<_Vp> | |
1455 | iter_move(const _Iterator& __i) | |
1456 | noexcept(noexcept(ranges::iter_move(__i._M_current))) | |
1457 | { return ranges::iter_move(__i._M_current); } | |
1458 | ||
1459 | friend constexpr void | |
1460 | iter_swap(const _Iterator& __x, const _Iterator& __y) | |
1461 | noexcept(noexcept(ranges::iter_swap(__x._M_current, __y._M_current))) | |
a5b213dd | 1462 | requires indirectly_swappable<_Vp_iter> |
cba9ef06 PP |
1463 | { ranges::iter_swap(__x._M_current, __y._M_current); } |
1464 | }; | |
1465 | ||
1466 | struct _Sentinel | |
1467 | { | |
1468 | private: | |
1469 | sentinel_t<_Vp> _M_end = sentinel_t<_Vp>(); | |
1470 | ||
1471 | constexpr bool | |
1472 | __equal(const _Iterator& __i) const | |
1473 | { return __i._M_current == _M_end; } | |
1474 | ||
1475 | public: | |
1476 | _Sentinel() = default; | |
1477 | ||
1478 | constexpr explicit | |
1479 | _Sentinel(filter_view& __parent) | |
1480 | : _M_end(ranges::end(__parent._M_base)) | |
1481 | { } | |
1482 | ||
1483 | constexpr sentinel_t<_Vp> | |
1484 | base() const | |
1485 | { return _M_end; } | |
1486 | ||
1487 | friend constexpr bool | |
1488 | operator==(const _Iterator& __x, const _Sentinel& __y) | |
1489 | { return __y.__equal(__x); } | |
1490 | }; | |
1491 | ||
1492 | _Vp _M_base = _Vp(); | |
1493 | __detail::__box<_Pred> _M_pred; | |
1494 | ||
1495 | public: | |
1496 | filter_view() = default; | |
1497 | ||
1498 | constexpr | |
1499 | filter_view(_Vp __base, _Pred __pred) | |
1500 | : _M_base(std::move(__base)), _M_pred(std::move(__pred)) | |
1501 | { } | |
1502 | ||
cba9ef06 PP |
1503 | constexpr _Vp |
1504 | base() const& requires copy_constructible<_Vp> | |
1505 | { return _M_base; } | |
1506 | ||
1507 | constexpr _Vp | |
1508 | base() && | |
1509 | { return std::move(_M_base); } | |
1510 | ||
242b4fb7 PP |
1511 | constexpr const _Pred& |
1512 | pred() const | |
1513 | { return *_M_pred; } | |
1514 | ||
cba9ef06 PP |
1515 | constexpr _Iterator |
1516 | begin() | |
1517 | { | |
1518 | // XXX: we need to cache the result here as per [range.filter.view] | |
1519 | __glibcxx_assert(_M_pred.has_value()); | |
1520 | return {*this, __detail::find_if(ranges::begin(_M_base), | |
1521 | ranges::end(_M_base), | |
1522 | std::ref(*_M_pred))}; | |
1523 | } | |
1524 | ||
1525 | constexpr auto | |
1526 | end() | |
1527 | { | |
1528 | if constexpr (common_range<_Vp>) | |
1529 | return _Iterator{*this, ranges::end(_M_base)}; | |
1530 | else | |
1531 | return _Sentinel{*this}; | |
1532 | } | |
1533 | }; | |
1534 | ||
1535 | template<typename _Range, typename _Pred> | |
aca60ecf | 1536 | filter_view(_Range&&, _Pred) -> filter_view<views::all_t<_Range>, _Pred>; |
cba9ef06 PP |
1537 | |
1538 | namespace views | |
1539 | { | |
1540 | inline constexpr __adaptor::_RangeAdaptor filter | |
1541 | = [] <viewable_range _Range, typename _Pred> (_Range&& __r, _Pred&& __p) | |
1542 | { | |
1543 | return filter_view{std::forward<_Range>(__r), std::forward<_Pred>(__p)}; | |
1544 | }; | |
1545 | } // namespace views | |
1546 | ||
1547 | template<input_range _Vp, copy_constructible _Fp> | |
1548 | requires view<_Vp> && is_object_v<_Fp> | |
1549 | && regular_invocable<_Fp&, range_reference_t<_Vp>> | |
ec15da7c PP |
1550 | && std::__detail::__can_reference<invoke_result_t<_Fp&, |
1551 | range_reference_t<_Vp>>> | |
cba9ef06 PP |
1552 | class transform_view : public view_interface<transform_view<_Vp, _Fp>> |
1553 | { | |
1554 | private: | |
1555 | template<bool _Const> | |
1556 | struct _Sentinel; | |
1557 | ||
1558 | template<bool _Const> | |
1559 | struct _Iterator | |
1560 | { | |
1561 | private: | |
8017d95c JW |
1562 | using _Parent = __detail::__maybe_const_t<_Const, transform_view>; |
1563 | using _Base = __detail::__maybe_const_t<_Const, _Vp>; | |
cba9ef06 PP |
1564 | |
1565 | static constexpr auto | |
1566 | _S_iter_concept() | |
1567 | { | |
1568 | if constexpr (random_access_range<_Vp>) | |
1569 | return random_access_iterator_tag{}; | |
1570 | else if constexpr (bidirectional_range<_Vp>) | |
1571 | return bidirectional_iterator_tag{}; | |
1572 | else if constexpr (forward_range<_Vp>) | |
1573 | return forward_iterator_tag{}; | |
1574 | else | |
1575 | return input_iterator_tag{}; | |
1576 | } | |
1577 | ||
1578 | static constexpr auto | |
1579 | _S_iter_cat() | |
1580 | { | |
510bd1c1 PP |
1581 | using _Res = invoke_result_t<_Fp&, range_reference_t<_Base>>; |
1582 | if constexpr (is_lvalue_reference_v<_Res>) | |
1583 | { | |
1584 | using _Cat | |
1585 | = typename iterator_traits<_Base_iter>::iterator_category; | |
1586 | if constexpr (derived_from<_Cat, contiguous_iterator_tag>) | |
1587 | return random_access_iterator_tag{}; | |
1588 | else | |
1589 | return _Cat{}; | |
1590 | } | |
cba9ef06 | 1591 | else |
510bd1c1 | 1592 | return input_iterator_tag{}; |
cba9ef06 PP |
1593 | } |
1594 | ||
1595 | static constexpr decltype(auto) | |
1596 | __iter_move(const _Iterator& __i = {}) | |
1597 | noexcept(noexcept(std::__invoke(*__i._M_parent->_M_fun, | |
1598 | *__i._M_current))) | |
1599 | { | |
1600 | if constexpr (is_lvalue_reference_v<decltype(*__i)>) | |
1601 | return std::move(*__i); | |
1602 | else | |
1603 | return *__i; | |
1604 | } | |
1605 | ||
a5b213dd JW |
1606 | using _Base_iter = iterator_t<_Base>; |
1607 | ||
1608 | _Base_iter _M_current = _Base_iter(); | |
cba9ef06 PP |
1609 | _Parent* _M_parent = nullptr; |
1610 | ||
1611 | public: | |
1612 | using iterator_concept = decltype(_S_iter_concept()); | |
1613 | using iterator_category = decltype(_S_iter_cat()); | |
1614 | using value_type | |
1615 | = remove_cvref_t<invoke_result_t<_Fp&, range_reference_t<_Base>>>; | |
1616 | using difference_type = range_difference_t<_Base>; | |
1617 | ||
1618 | _Iterator() = default; | |
1619 | ||
1620 | constexpr | |
a5b213dd | 1621 | _Iterator(_Parent& __parent, _Base_iter __current) |
cba9ef06 PP |
1622 | : _M_current(std::move(__current)), |
1623 | _M_parent(std::__addressof(__parent)) | |
1624 | { } | |
1625 | ||
1626 | constexpr | |
1627 | _Iterator(_Iterator<!_Const> __i) | |
1628 | requires _Const | |
a5b213dd | 1629 | && convertible_to<iterator_t<_Vp>, _Base_iter> |
cba9ef06 PP |
1630 | : _M_current(std::move(__i._M_current)), _M_parent(__i._M_parent) |
1631 | { } | |
1632 | ||
a5b213dd | 1633 | constexpr _Base_iter |
cba9ef06 | 1634 | base() const & |
a5b213dd | 1635 | requires copyable<_Base_iter> |
cba9ef06 PP |
1636 | { return _M_current; } |
1637 | ||
a5b213dd | 1638 | constexpr _Base_iter |
cba9ef06 PP |
1639 | base() && |
1640 | { return std::move(_M_current); } | |
1641 | ||
1642 | constexpr decltype(auto) | |
1643 | operator*() const | |
1644 | { return std::__invoke(*_M_parent->_M_fun, *_M_current); } | |
1645 | ||
1646 | constexpr _Iterator& | |
1647 | operator++() | |
1648 | { | |
1649 | ++_M_current; | |
1650 | return *this; | |
1651 | } | |
1652 | ||
1653 | constexpr void | |
1654 | operator++(int) | |
1655 | { ++_M_current; } | |
1656 | ||
1657 | constexpr _Iterator | |
1658 | operator++(int) requires forward_range<_Base> | |
1659 | { | |
1660 | auto __tmp = *this; | |
1661 | ++*this; | |
1662 | return __tmp; | |
1663 | } | |
1664 | ||
1665 | constexpr _Iterator& | |
1666 | operator--() requires bidirectional_range<_Base> | |
1667 | { | |
1668 | --_M_current; | |
1669 | return *this; | |
1670 | } | |
1671 | ||
1672 | constexpr _Iterator | |
1673 | operator--(int) requires bidirectional_range<_Base> | |
1674 | { | |
1675 | auto __tmp = *this; | |
1676 | --*this; | |
1677 | return __tmp; | |
1678 | } | |
1679 | ||
1680 | constexpr _Iterator& | |
1681 | operator+=(difference_type __n) requires random_access_range<_Base> | |
1682 | { | |
1683 | _M_current += __n; | |
1684 | return *this; | |
1685 | } | |
1686 | ||
1687 | constexpr _Iterator& | |
1688 | operator-=(difference_type __n) requires random_access_range<_Base> | |
1689 | { | |
1690 | _M_current -= __n; | |
1691 | return *this; | |
1692 | } | |
1693 | ||
1694 | constexpr decltype(auto) | |
1695 | operator[](difference_type __n) const | |
1696 | requires random_access_range<_Base> | |
1697 | { return std::__invoke(*_M_parent->_M_fun, _M_current[__n]); } | |
1698 | ||
1699 | friend constexpr bool | |
1700 | operator==(const _Iterator& __x, const _Iterator& __y) | |
a5b213dd | 1701 | requires equality_comparable<_Base_iter> |
cba9ef06 PP |
1702 | { return __x._M_current == __y._M_current; } |
1703 | ||
1704 | friend constexpr bool | |
1705 | operator<(const _Iterator& __x, const _Iterator& __y) | |
1706 | requires random_access_range<_Base> | |
1707 | { return __x._M_current < __y._M_current; } | |
1708 | ||
1709 | friend constexpr bool | |
1710 | operator>(const _Iterator& __x, const _Iterator& __y) | |
1711 | requires random_access_range<_Base> | |
1712 | { return __y < __x; } | |
1713 | ||
1714 | friend constexpr bool | |
1715 | operator<=(const _Iterator& __x, const _Iterator& __y) | |
1716 | requires random_access_range<_Base> | |
1717 | { return !(__y < __x); } | |
1718 | ||
1719 | friend constexpr bool | |
1720 | operator>=(const _Iterator& __x, const _Iterator& __y) | |
1721 | requires random_access_range<_Base> | |
1722 | { return !(__x < __y); } | |
1723 | ||
1724 | #ifdef __cpp_lib_three_way_comparison | |
1725 | friend constexpr auto | |
1726 | operator<=>(const _Iterator& __x, const _Iterator& __y) | |
1727 | requires random_access_range<_Base> | |
a5b213dd | 1728 | && three_way_comparable<_Base_iter> |
cba9ef06 PP |
1729 | { return __x._M_current <=> __y._M_current; } |
1730 | #endif | |
1731 | ||
1732 | friend constexpr _Iterator | |
1733 | operator+(_Iterator __i, difference_type __n) | |
1734 | requires random_access_range<_Base> | |
1735 | { return {*__i._M_parent, __i._M_current + __n}; } | |
1736 | ||
1737 | friend constexpr _Iterator | |
1738 | operator+(difference_type __n, _Iterator __i) | |
1739 | requires random_access_range<_Base> | |
1740 | { return {*__i._M_parent, __i._M_current + __n}; } | |
1741 | ||
1742 | friend constexpr _Iterator | |
1743 | operator-(_Iterator __i, difference_type __n) | |
1744 | requires random_access_range<_Base> | |
1745 | { return {*__i._M_parent, __i._M_current - __n}; } | |
1746 | ||
1747 | friend constexpr difference_type | |
1748 | operator-(const _Iterator& __x, const _Iterator& __y) | |
1749 | requires random_access_range<_Base> | |
1750 | { return __x._M_current - __y._M_current; } | |
1751 | ||
1752 | friend constexpr decltype(auto) | |
1753 | iter_move(const _Iterator& __i) noexcept(noexcept(__iter_move())) | |
1754 | { return __iter_move(__i); } | |
1755 | ||
1756 | friend constexpr void | |
1757 | iter_swap(const _Iterator& __x, const _Iterator& __y) | |
1758 | noexcept(noexcept(ranges::iter_swap(__x._M_current, __y._M_current))) | |
a5b213dd | 1759 | requires indirectly_swappable<_Base_iter> |
cba9ef06 PP |
1760 | { return ranges::iter_swap(__x._M_current, __y._M_current); } |
1761 | ||
1762 | friend _Sentinel<_Const>; | |
1763 | }; | |
1764 | ||
1765 | template<bool _Const> | |
1766 | struct _Sentinel | |
1767 | { | |
1768 | private: | |
8017d95c JW |
1769 | using _Parent = __detail::__maybe_const_t<_Const, transform_view>; |
1770 | using _Base = __detail::__maybe_const_t<_Const, _Vp>; | |
cba9ef06 PP |
1771 | |
1772 | constexpr range_difference_t<_Base> | |
1773 | __distance_from(const _Iterator<_Const>& __i) const | |
1774 | { return _M_end - __i._M_current; } | |
1775 | ||
1776 | constexpr bool | |
1777 | __equal(const _Iterator<_Const>& __i) const | |
1778 | { return __i._M_current == _M_end; } | |
1779 | ||
1780 | sentinel_t<_Base> _M_end = sentinel_t<_Base>(); | |
1781 | ||
1782 | public: | |
1783 | _Sentinel() = default; | |
1784 | ||
1785 | constexpr explicit | |
1786 | _Sentinel(sentinel_t<_Base> __end) | |
1787 | : _M_end(__end) | |
1788 | { } | |
1789 | ||
1790 | constexpr | |
1791 | _Sentinel(_Sentinel<!_Const> __i) | |
1792 | requires _Const | |
1793 | && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>> | |
1794 | : _M_end(std::move(__i._M_end)) | |
1795 | { } | |
1796 | ||
1797 | constexpr sentinel_t<_Base> | |
1798 | base() const | |
1799 | { return _M_end; } | |
1800 | ||
1801 | friend constexpr bool | |
1802 | operator==(const _Iterator<_Const>& __x, const _Sentinel& __y) | |
1803 | { return __y.__equal(__x); } | |
1804 | ||
1805 | friend constexpr range_difference_t<_Base> | |
1806 | operator-(const _Iterator<_Const>& __x, const _Sentinel& __y) | |
1807 | requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base>> | |
1808 | { return -__y.__distance_from(__x); } | |
1809 | ||
1810 | friend constexpr range_difference_t<_Base> | |
1811 | operator-(const _Sentinel& __y, const _Iterator<_Const>& __x) | |
1812 | requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base>> | |
1813 | { return __y.__distance_from(__x); } | |
1814 | }; | |
1815 | ||
1816 | _Vp _M_base = _Vp(); | |
1817 | __detail::__box<_Fp> _M_fun; | |
1818 | ||
1819 | public: | |
1820 | transform_view() = default; | |
1821 | ||
1822 | constexpr | |
1823 | transform_view(_Vp __base, _Fp __fun) | |
1824 | : _M_base(std::move(__base)), _M_fun(std::move(__fun)) | |
1825 | { } | |
1826 | ||
cba9ef06 PP |
1827 | constexpr _Vp |
1828 | base() const& requires copy_constructible<_Vp> | |
1829 | { return _M_base ; } | |
1830 | ||
1831 | constexpr _Vp | |
1832 | base() && | |
1833 | { return std::move(_M_base); } | |
1834 | ||
1835 | constexpr _Iterator<false> | |
1836 | begin() | |
1837 | { return _Iterator<false>{*this, ranges::begin(_M_base)}; } | |
1838 | ||
1839 | constexpr _Iterator<true> | |
1840 | begin() const | |
1841 | requires range<const _Vp> | |
1842 | && regular_invocable<const _Fp&, range_reference_t<const _Vp>> | |
1843 | { return _Iterator<true>{*this, ranges::begin(_M_base)}; } | |
1844 | ||
1845 | constexpr _Sentinel<false> | |
1846 | end() | |
1847 | { return _Sentinel<false>{ranges::end(_M_base)}; } | |
1848 | ||
1849 | constexpr _Iterator<false> | |
1850 | end() requires common_range<_Vp> | |
1851 | { return _Iterator<false>{*this, ranges::end(_M_base)}; } | |
1852 | ||
1853 | constexpr _Sentinel<true> | |
1854 | end() const | |
1855 | requires range<const _Vp> | |
1856 | && regular_invocable<const _Fp&, range_reference_t<const _Vp>> | |
1857 | { return _Sentinel<true>{ranges::end(_M_base)}; } | |
1858 | ||
1859 | constexpr _Iterator<true> | |
1860 | end() const | |
1861 | requires common_range<const _Vp> | |
1862 | && regular_invocable<const _Fp&, range_reference_t<const _Vp>> | |
1863 | { return _Iterator<true>{*this, ranges::end(_M_base)}; } | |
1864 | ||
1865 | constexpr auto | |
1866 | size() requires sized_range<_Vp> | |
1867 | { return ranges::size(_M_base); } | |
1868 | ||
1869 | constexpr auto | |
1870 | size() const requires sized_range<const _Vp> | |
1871 | { return ranges::size(_M_base); } | |
1872 | }; | |
1873 | ||
1874 | template<typename _Range, typename _Fp> | |
aca60ecf | 1875 | transform_view(_Range&&, _Fp) -> transform_view<views::all_t<_Range>, _Fp>; |
cba9ef06 PP |
1876 | |
1877 | namespace views | |
1878 | { | |
1879 | inline constexpr __adaptor::_RangeAdaptor transform | |
1880 | = [] <viewable_range _Range, typename _Fp> (_Range&& __r, _Fp&& __f) | |
1881 | { | |
1882 | return transform_view{std::forward<_Range>(__r), std::forward<_Fp>(__f)}; | |
1883 | }; | |
1884 | } // namespace views | |
1885 | ||
1886 | template<view _Vp> | |
1887 | class take_view : public view_interface<take_view<_Vp>> | |
1888 | { | |
1889 | private: | |
1890 | template<bool _Const> | |
1891 | struct _Sentinel | |
1892 | { | |
1893 | private: | |
8017d95c | 1894 | using _Base = __detail::__maybe_const_t<_Const, _Vp>; |
cba9ef06 PP |
1895 | using _CI = counted_iterator<iterator_t<_Base>>; |
1896 | ||
1897 | sentinel_t<_Base> _M_end = sentinel_t<_Base>(); | |
1898 | ||
1899 | public: | |
1900 | _Sentinel() = default; | |
1901 | ||
1902 | constexpr explicit | |
1903 | _Sentinel(sentinel_t<_Base> __end) | |
1904 | : _M_end(__end) | |
1905 | { } | |
1906 | ||
1907 | constexpr | |
1908 | _Sentinel(_Sentinel<!_Const> __s) | |
1909 | requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>> | |
1910 | : _M_end(std::move(__s._M_end)) | |
1911 | { } | |
1912 | ||
1913 | constexpr sentinel_t<_Base> | |
1914 | base() const | |
1915 | { return _M_end; } | |
1916 | ||
1917 | friend constexpr bool operator==(const _CI& __y, const _Sentinel& __x) | |
1918 | { return __y.count() == 0 || __y.base() == __x._M_end; } | |
1919 | }; | |
1920 | ||
1921 | _Vp _M_base = _Vp(); | |
1922 | range_difference_t<_Vp> _M_count = 0; | |
1923 | ||
1924 | public: | |
1925 | take_view() = default; | |
1926 | ||
1927 | constexpr | |
1928 | take_view(_Vp base, range_difference_t<_Vp> __count) | |
1929 | : _M_base(std::move(base)), _M_count(std::move(__count)) | |
1930 | { } | |
1931 | ||
cba9ef06 PP |
1932 | constexpr _Vp |
1933 | base() const& requires copy_constructible<_Vp> | |
1934 | { return _M_base; } | |
1935 | ||
1936 | constexpr _Vp | |
1937 | base() && | |
1938 | { return std::move(_M_base); } | |
1939 | ||
1940 | constexpr auto | |
1941 | begin() requires (!__detail::__simple_view<_Vp>) | |
1942 | { | |
1943 | if constexpr (sized_range<_Vp>) | |
1944 | { | |
1945 | if constexpr (random_access_range<_Vp>) | |
1946 | return ranges::begin(_M_base); | |
1947 | else | |
1948 | return counted_iterator{ranges::begin(_M_base), size()}; | |
1949 | } | |
1950 | else | |
1951 | return counted_iterator{ranges::begin(_M_base), _M_count}; | |
1952 | } | |
1953 | ||
1954 | constexpr auto | |
1955 | begin() const requires range<const _Vp> | |
1956 | { | |
1957 | if constexpr (sized_range<const _Vp>) | |
1958 | { | |
1959 | if constexpr (random_access_range<const _Vp>) | |
1960 | return ranges::begin(_M_base); | |
1961 | else | |
1962 | return counted_iterator{ranges::begin(_M_base), size()}; | |
1963 | } | |
1964 | else | |
1965 | return counted_iterator{ranges::begin(_M_base), _M_count}; | |
1966 | } | |
1967 | ||
1968 | constexpr auto | |
1969 | end() requires (!__detail::__simple_view<_Vp>) | |
1970 | { | |
1971 | if constexpr (sized_range<_Vp>) | |
1972 | { | |
1973 | if constexpr (random_access_range<_Vp>) | |
1974 | return ranges::begin(_M_base) + size(); | |
1975 | else | |
1976 | return default_sentinel; | |
1977 | } | |
1978 | else | |
1979 | return _Sentinel<false>{ranges::end(_M_base)}; | |
1980 | } | |
1981 | ||
1982 | constexpr auto | |
1983 | end() const requires range<const _Vp> | |
1984 | { | |
1985 | if constexpr (sized_range<const _Vp>) | |
1986 | { | |
1987 | if constexpr (random_access_range<const _Vp>) | |
1988 | return ranges::begin(_M_base) + size(); | |
1989 | else | |
1990 | return default_sentinel; | |
1991 | } | |
1992 | else | |
1993 | return _Sentinel<true>{ranges::end(_M_base)}; | |
1994 | } | |
1995 | ||
1996 | constexpr auto | |
1997 | size() requires sized_range<_Vp> | |
1998 | { | |
1999 | auto __n = ranges::size(_M_base); | |
2000 | return __detail::min(__n, static_cast<decltype(__n)>(_M_count)); | |
2001 | } | |
2002 | ||
2003 | constexpr auto | |
2004 | size() const requires sized_range<const _Vp> | |
2005 | { | |
2006 | auto __n = ranges::size(_M_base); | |
2007 | return __detail::min(__n, static_cast<decltype(__n)>(_M_count)); | |
2008 | } | |
2009 | }; | |
2010 | ||
2011 | template<range _Range> | |
2012 | take_view(_Range&&, range_difference_t<_Range>) | |
aca60ecf | 2013 | -> take_view<views::all_t<_Range>>; |
cba9ef06 PP |
2014 | |
2015 | namespace views | |
2016 | { | |
2017 | inline constexpr __adaptor::_RangeAdaptor take | |
2018 | = [] <viewable_range _Range, typename _Tp> (_Range&& __r, _Tp&& __n) | |
2019 | { | |
2020 | return take_view{std::forward<_Range>(__r), std::forward<_Tp>(__n)}; | |
2021 | }; | |
2022 | } // namespace views | |
2023 | ||
2024 | template<view _Vp, typename _Pred> | |
2025 | requires input_range<_Vp> && is_object_v<_Pred> | |
2026 | && indirect_unary_predicate<const _Pred, iterator_t<_Vp>> | |
2027 | class take_while_view : public view_interface<take_while_view<_Vp, _Pred>> | |
2028 | { | |
2029 | template<bool _Const> | |
2030 | struct _Sentinel | |
2031 | { | |
2032 | private: | |
8017d95c | 2033 | using _Base = __detail::__maybe_const_t<_Const, _Vp>; |
cba9ef06 PP |
2034 | |
2035 | sentinel_t<_Base> _M_end = sentinel_t<_Base>(); | |
2036 | const _Pred* _M_pred = nullptr; | |
2037 | ||
2038 | public: | |
2039 | _Sentinel() = default; | |
2040 | ||
2041 | constexpr explicit | |
2042 | _Sentinel(sentinel_t<_Base> __end, const _Pred* __pred) | |
2043 | : _M_end(__end), _M_pred(__pred) | |
2044 | { } | |
2045 | ||
2046 | constexpr | |
2047 | _Sentinel(_Sentinel<!_Const> __s) | |
2048 | requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>> | |
2049 | : _M_end(__s._M_end), _M_pred(__s._M_pred) | |
2050 | { } | |
2051 | ||
2052 | constexpr sentinel_t<_Base> | |
2053 | base() const { return _M_end; } | |
2054 | ||
2055 | friend constexpr bool | |
2056 | operator==(const iterator_t<_Base>& __x, const _Sentinel& __y) | |
2057 | { return __y._M_end == __x || !std::__invoke(*__y._M_pred, *__x); } | |
2058 | }; | |
2059 | ||
7433536b | 2060 | _Vp _M_base = _Vp(); |
cba9ef06 PP |
2061 | __detail::__box<_Pred> _M_pred; |
2062 | ||
2063 | public: | |
2064 | take_while_view() = default; | |
2065 | ||
2066 | constexpr | |
2067 | take_while_view(_Vp base, _Pred __pred) | |
2068 | : _M_base(std::move(base)), _M_pred(std::move(__pred)) | |
2069 | { | |
2070 | } | |
2071 | ||
2072 | constexpr _Vp | |
2073 | base() const& requires copy_constructible<_Vp> | |
2074 | { return _M_base; } | |
2075 | ||
2076 | constexpr _Vp | |
2077 | base() && | |
2078 | { return std::move(_M_base); } | |
2079 | ||
2080 | constexpr const _Pred& | |
2081 | pred() const | |
2082 | { return *_M_pred; } | |
2083 | ||
2084 | constexpr auto | |
2085 | begin() requires (!__detail::__simple_view<_Vp>) | |
2086 | { return ranges::begin(_M_base); } | |
2087 | ||
2088 | constexpr auto | |
2089 | begin() const requires range<const _Vp> | |
2090 | { return ranges::begin(_M_base); } | |
2091 | ||
2092 | constexpr auto | |
2093 | end() requires (!__detail::__simple_view<_Vp>) | |
2094 | { return _Sentinel<false>(ranges::end(_M_base), | |
2095 | std::__addressof(*_M_pred)); } | |
2096 | ||
2097 | constexpr auto | |
2098 | end() const requires range<const _Vp> | |
2099 | { return _Sentinel<true>(ranges::end(_M_base), | |
2100 | std::__addressof(*_M_pred)); } | |
2101 | }; | |
2102 | ||
2103 | template<typename _Range, typename _Pred> | |
2104 | take_while_view(_Range&&, _Pred) | |
aca60ecf | 2105 | -> take_while_view<views::all_t<_Range>, _Pred>; |
cba9ef06 PP |
2106 | |
2107 | namespace views | |
2108 | { | |
2109 | inline constexpr __adaptor::_RangeAdaptor take_while | |
2110 | = [] <viewable_range _Range, typename _Pred> (_Range&& __r, _Pred&& __p) | |
2111 | { | |
2112 | return take_while_view{std::forward<_Range>(__r), std::forward<_Pred>(__p)}; | |
2113 | }; | |
2114 | } // namespace views | |
2115 | ||
2116 | template<view _Vp> | |
2117 | class drop_view : public view_interface<drop_view<_Vp>> | |
2118 | { | |
2119 | private: | |
7433536b JW |
2120 | _Vp _M_base = _Vp(); |
2121 | range_difference_t<_Vp> _M_count = 0; | |
cba9ef06 PP |
2122 | |
2123 | public: | |
2124 | drop_view() = default; | |
2125 | ||
2126 | constexpr | |
2127 | drop_view(_Vp __base, range_difference_t<_Vp> __count) | |
2128 | : _M_base(std::move(__base)), _M_count(__count) | |
2129 | { __glibcxx_assert(__count >= 0); } | |
2130 | ||
2131 | constexpr _Vp | |
2132 | base() const& requires copy_constructible<_Vp> | |
2133 | { return _M_base; } | |
2134 | ||
2135 | constexpr _Vp | |
2136 | base() && | |
2137 | { return std::move(_M_base); } | |
2138 | ||
2139 | constexpr auto | |
2140 | begin() requires (!(__detail::__simple_view<_Vp> | |
2141 | && random_access_range<_Vp>)) | |
2142 | { | |
2143 | // XXX: we need to cache the result here as per [range.drop.view] | |
2144 | return ranges::next(ranges::begin(_M_base), _M_count, | |
2145 | ranges::end(_M_base)); | |
2146 | } | |
2147 | ||
2148 | constexpr auto | |
2149 | begin() const requires random_access_range<const _Vp> | |
2150 | { | |
2151 | return ranges::next(ranges::begin(_M_base), _M_count, | |
2152 | ranges::end(_M_base)); | |
2153 | } | |
2154 | ||
2155 | constexpr auto | |
2156 | end() requires (!__detail::__simple_view<_Vp>) | |
2157 | { return ranges::end(_M_base); } | |
2158 | ||
2159 | constexpr auto | |
2160 | end() const requires range<const _Vp> | |
2161 | { return ranges::end(_M_base); } | |
2162 | ||
2163 | constexpr auto | |
2164 | size() requires sized_range<_Vp> | |
2165 | { | |
2166 | const auto __s = ranges::size(_M_base); | |
2167 | const auto __c = static_cast<decltype(__s)>(_M_count); | |
2168 | return __s < __c ? 0 : __s - __c; | |
2169 | } | |
2170 | ||
2171 | constexpr auto | |
2172 | size() const requires sized_range<const _Vp> | |
2173 | { | |
2174 | const auto __s = ranges::size(_M_base); | |
2175 | const auto __c = static_cast<decltype(__s)>(_M_count); | |
2176 | return __s < __c ? 0 : __s - __c; | |
2177 | } | |
2178 | }; | |
2179 | ||
2180 | template<typename _Range> | |
2181 | drop_view(_Range&&, range_difference_t<_Range>) | |
aca60ecf | 2182 | -> drop_view<views::all_t<_Range>>; |
cba9ef06 PP |
2183 | |
2184 | namespace views | |
2185 | { | |
2186 | inline constexpr __adaptor::_RangeAdaptor drop | |
2187 | = [] <viewable_range _Range, typename _Tp> (_Range&& __r, _Tp&& __n) | |
2188 | { | |
2189 | return drop_view{std::forward<_Range>(__r), std::forward<_Tp>(__n)}; | |
2190 | }; | |
2191 | } // namespace views | |
2192 | ||
2193 | template<view _Vp, typename _Pred> | |
2194 | requires input_range<_Vp> && is_object_v<_Pred> | |
2195 | && indirect_unary_predicate<const _Pred, iterator_t<_Vp>> | |
2196 | class drop_while_view : public view_interface<drop_while_view<_Vp, _Pred>> | |
2197 | { | |
2198 | private: | |
7433536b | 2199 | _Vp _M_base = _Vp(); |
cba9ef06 PP |
2200 | __detail::__box<_Pred> _M_pred; |
2201 | ||
2202 | public: | |
2203 | drop_while_view() = default; | |
2204 | ||
2205 | constexpr | |
2206 | drop_while_view(_Vp __base, _Pred __pred) | |
2207 | : _M_base(std::move(__base)), _M_pred(std::move(__pred)) | |
2208 | { } | |
2209 | ||
2210 | constexpr _Vp | |
2211 | base() const& requires copy_constructible<_Vp> | |
2212 | { return _M_base; } | |
2213 | ||
2214 | constexpr _Vp | |
2215 | base() && | |
2216 | { return std::move(_M_base); } | |
2217 | ||
2218 | constexpr const _Pred& | |
2219 | pred() const | |
2220 | { return *_M_pred; } | |
2221 | ||
2222 | constexpr auto | |
2223 | begin() | |
2224 | { | |
2225 | // XXX: we need to cache the result here as per [range.drop.while.view] | |
2226 | return __detail::find_if_not(ranges::begin(_M_base), | |
2227 | ranges::end(_M_base), | |
2228 | std::cref(*_M_pred)); | |
2229 | } | |
2230 | ||
2231 | constexpr auto | |
2232 | end() | |
2233 | { return ranges::end(_M_base); } | |
2234 | }; | |
2235 | ||
2236 | template<typename _Range, typename _Pred> | |
2237 | drop_while_view(_Range&&, _Pred) | |
aca60ecf | 2238 | -> drop_while_view<views::all_t<_Range>, _Pred>; |
cba9ef06 PP |
2239 | |
2240 | namespace views | |
2241 | { | |
2242 | inline constexpr __adaptor::_RangeAdaptor drop_while | |
2243 | = [] <viewable_range _Range, typename _Pred> (_Range&& __r, _Pred&& __p) | |
2244 | { | |
2245 | return drop_while_view{std::forward<_Range>(__r), | |
2246 | std::forward<_Pred>(__p)}; | |
2247 | }; | |
2248 | } // namespace views | |
2249 | ||
2250 | template<input_range _Vp> | |
2251 | requires view<_Vp> && input_range<range_reference_t<_Vp>> | |
2252 | && (is_reference_v<range_reference_t<_Vp>> | |
2253 | || view<range_value_t<_Vp>>) | |
2254 | class join_view : public view_interface<join_view<_Vp>> | |
2255 | { | |
2256 | private: | |
2257 | using _InnerRange = range_reference_t<_Vp>; | |
2258 | ||
2259 | template<bool _Const> | |
2260 | struct _Sentinel; | |
2261 | ||
2262 | template<bool _Const> | |
2263 | struct _Iterator | |
2264 | { | |
2265 | private: | |
8017d95c JW |
2266 | using _Parent = __detail::__maybe_const_t<_Const, join_view>; |
2267 | using _Base = __detail::__maybe_const_t<_Const, _Vp>; | |
cba9ef06 PP |
2268 | |
2269 | static constexpr bool _S_ref_is_glvalue | |
2270 | = is_reference_v<range_reference_t<_Base>>; | |
2271 | ||
2272 | constexpr void | |
2273 | _M_satisfy() | |
2274 | { | |
2275 | auto __update_inner = [this] (range_reference_t<_Base> __x) -> auto& | |
2276 | { | |
2277 | if constexpr (_S_ref_is_glvalue) | |
2278 | return __x; | |
2279 | else | |
2280 | return (_M_parent->_M_inner = views::all(std::move(__x))); | |
2281 | }; | |
2282 | ||
2283 | for (; _M_outer != ranges::end(_M_parent->_M_base); ++_M_outer) | |
2284 | { | |
2285 | auto& inner = __update_inner(*_M_outer); | |
2286 | _M_inner = ranges::begin(inner); | |
2287 | if (_M_inner != ranges::end(inner)) | |
2288 | return; | |
2289 | } | |
2290 | ||
2291 | if constexpr (_S_ref_is_glvalue) | |
a5b213dd | 2292 | _M_inner = _Inner_iter(); |
cba9ef06 PP |
2293 | } |
2294 | ||
2295 | static constexpr auto | |
2296 | _S_iter_concept() | |
2297 | { | |
2298 | if constexpr (_S_ref_is_glvalue | |
2299 | && bidirectional_range<_Base> | |
2300 | && bidirectional_range<range_reference_t<_Base>>) | |
2301 | return bidirectional_iterator_tag{}; | |
2302 | else if constexpr (_S_ref_is_glvalue | |
2303 | && forward_range<_Base> | |
2304 | && forward_range<range_reference_t<_Base>>) | |
2305 | return forward_iterator_tag{}; | |
2306 | else | |
2307 | return input_iterator_tag{}; | |
2308 | } | |
2309 | ||
2310 | static constexpr auto | |
2311 | _S_iter_cat() | |
2312 | { | |
2313 | using _OuterCat | |
a5b213dd | 2314 | = typename iterator_traits<_Outer_iter>::iterator_category; |
cba9ef06 | 2315 | using _InnerCat |
a5b213dd | 2316 | = typename iterator_traits<_Inner_iter>::iterator_category; |
cba9ef06 PP |
2317 | if constexpr (_S_ref_is_glvalue |
2318 | && derived_from<_OuterCat, bidirectional_iterator_tag> | |
2319 | && derived_from<_InnerCat, bidirectional_iterator_tag>) | |
2320 | return bidirectional_iterator_tag{}; | |
2321 | else if constexpr (_S_ref_is_glvalue | |
2322 | && derived_from<_OuterCat, forward_iterator_tag> | |
2323 | && derived_from<_InnerCat, forward_iterator_tag>) | |
2324 | return forward_iterator_tag{}; | |
2325 | else if constexpr (derived_from<_OuterCat, input_iterator_tag> | |
2326 | && derived_from<_InnerCat, input_iterator_tag>) | |
2327 | return input_iterator_tag{}; | |
2328 | else | |
2329 | return output_iterator_tag{}; | |
2330 | } | |
2331 | ||
a5b213dd JW |
2332 | using _Outer_iter = iterator_t<_Base>; |
2333 | using _Inner_iter = iterator_t<range_reference_t<_Base>>; | |
2334 | ||
2335 | _Outer_iter _M_outer = _Outer_iter(); | |
2336 | _Inner_iter _M_inner = _Inner_iter(); | |
cba9ef06 PP |
2337 | _Parent* _M_parent = nullptr; |
2338 | ||
2339 | public: | |
2340 | using iterator_concept = decltype(_S_iter_concept()); | |
2341 | using iterator_category = decltype(_S_iter_cat()); | |
2342 | using value_type = range_value_t<range_reference_t<_Base>>; | |
2343 | using difference_type | |
2344 | = common_type_t<range_difference_t<_Base>, | |
2345 | range_difference_t<range_reference_t<_Base>>>; | |
2346 | ||
2347 | _Iterator() = default; | |
2348 | ||
cba9ef06 | 2349 | constexpr |
a5b213dd | 2350 | _Iterator(_Parent& __parent, _Outer_iter __outer) |
cba9ef06 PP |
2351 | : _M_outer(std::move(__outer)), |
2352 | _M_parent(std::__addressof(__parent)) | |
2353 | { _M_satisfy(); } | |
2354 | ||
2355 | constexpr | |
2356 | _Iterator(_Iterator<!_Const> __i) | |
2357 | requires _Const | |
a5b213dd JW |
2358 | && convertible_to<iterator_t<_Vp>, _Outer_iter> |
2359 | && convertible_to<iterator_t<_InnerRange>, _Inner_iter> | |
cba9ef06 PP |
2360 | : _M_outer(std::move(__i._M_outer)), _M_inner(__i._M_inner), |
2361 | _M_parent(__i._M_parent) | |
2362 | { } | |
2363 | ||
2364 | constexpr decltype(auto) | |
2365 | operator*() const | |
2366 | { return *_M_inner; } | |
2367 | ||
a5b213dd | 2368 | constexpr _Outer_iter |
cba9ef06 | 2369 | operator->() const |
a5b213dd JW |
2370 | requires __detail::__has_arrow<_Outer_iter> |
2371 | && copyable<_Outer_iter> | |
cba9ef06 PP |
2372 | { return _M_inner; } |
2373 | ||
2374 | constexpr _Iterator& | |
2375 | operator++() | |
2376 | { | |
2377 | auto&& __inner_range = [this] () -> decltype(auto) { | |
2378 | if constexpr (_S_ref_is_glvalue) | |
2379 | return *_M_outer; | |
2380 | else | |
2381 | return _M_parent->_M_inner; | |
2382 | }(); | |
2383 | if (++_M_inner == ranges::end(__inner_range)) | |
2384 | { | |
2385 | ++_M_outer; | |
2386 | _M_satisfy(); | |
2387 | } | |
2388 | return *this; | |
2389 | } | |
2390 | ||
2391 | constexpr void | |
2392 | operator++(int) | |
2393 | { ++*this; } | |
2394 | ||
2395 | constexpr _Iterator | |
2396 | operator++(int) | |
2397 | requires _S_ref_is_glvalue && forward_range<_Base> | |
2398 | && forward_range<range_reference_t<_Base>> | |
2399 | { | |
2400 | auto __tmp = *this; | |
2401 | ++*this; | |
2402 | return __tmp; | |
2403 | } | |
2404 | ||
2405 | constexpr _Iterator& | |
2406 | operator--() | |
2407 | requires _S_ref_is_glvalue && bidirectional_range<_Base> | |
2408 | && bidirectional_range<range_reference_t<_Base>> | |
55c4b3f4 | 2409 | && common_range<range_reference_t<_Base>> |
cba9ef06 PP |
2410 | { |
2411 | if (_M_outer == ranges::end(_M_parent->_M_base)) | |
2412 | _M_inner = ranges::end(*--_M_outer); | |
2413 | while (_M_inner == ranges::begin(*_M_outer)) | |
2414 | _M_inner = ranges::end(*--_M_outer); | |
2415 | --_M_inner; | |
2416 | return *this; | |
2417 | } | |
2418 | ||
2419 | constexpr _Iterator | |
2420 | operator--(int) | |
2421 | requires _S_ref_is_glvalue && bidirectional_range<_Base> | |
2422 | && bidirectional_range<range_reference_t<_Base>> | |
55c4b3f4 | 2423 | && common_range<range_reference_t<_Base>> |
cba9ef06 PP |
2424 | { |
2425 | auto __tmp = *this; | |
2426 | --*this; | |
2427 | return __tmp; | |
2428 | } | |
2429 | ||
2430 | friend constexpr bool | |
2431 | operator==(const _Iterator& __x, const _Iterator& __y) | |
2432 | requires _S_ref_is_glvalue | |
a5b213dd JW |
2433 | && equality_comparable<_Outer_iter> |
2434 | && equality_comparable<_Inner_iter> | |
cba9ef06 PP |
2435 | { |
2436 | return (__x._M_outer == __y._M_outer | |
2437 | && __x._M_inner == __y._M_inner); | |
2438 | } | |
2439 | ||
2440 | friend constexpr decltype(auto) | |
2441 | iter_move(const _Iterator& __i) | |
2442 | noexcept(noexcept(ranges::iter_move(__i._M_inner))) | |
2443 | { return ranges::iter_move(__i._M_inner); } | |
2444 | ||
2445 | friend constexpr void | |
2446 | iter_swap(const _Iterator& __x, const _Iterator& __y) | |
2447 | noexcept(noexcept(ranges::iter_swap(__x._M_inner, __y._M_inner))) | |
2448 | { return ranges::iter_swap(__x._M_inner, __y._M_inner); } | |
2449 | ||
242b4fb7 | 2450 | friend _Iterator<!_Const>; |
cba9ef06 PP |
2451 | friend _Sentinel<_Const>; |
2452 | }; | |
2453 | ||
2454 | template<bool _Const> | |
2455 | struct _Sentinel | |
2456 | { | |
2457 | private: | |
8017d95c JW |
2458 | using _Parent = __detail::__maybe_const_t<_Const, join_view>; |
2459 | using _Base = __detail::__maybe_const_t<_Const, _Vp>; | |
cba9ef06 PP |
2460 | |
2461 | constexpr bool | |
2462 | __equal(const _Iterator<_Const>& __i) const | |
2463 | { return __i._M_outer == _M_end; } | |
2464 | ||
2465 | sentinel_t<_Base> _M_end = sentinel_t<_Base>(); | |
2466 | ||
2467 | public: | |
2468 | _Sentinel() = default; | |
2469 | ||
2470 | constexpr explicit | |
2471 | _Sentinel(_Parent& __parent) | |
2472 | : _M_end(ranges::end(__parent._M_base)) | |
2473 | { } | |
2474 | ||
2475 | constexpr | |
2476 | _Sentinel(_Sentinel<!_Const> __s) | |
2477 | requires _Const && convertible_to<sentinel_t<_Vp>, sentinel_t<_Base>> | |
2478 | : _M_end(std::move(__s._M_end)) | |
2479 | { } | |
2480 | ||
2481 | friend constexpr bool | |
2482 | operator==(const _Iterator<_Const>& __x, const _Sentinel& __y) | |
2483 | { return __y.__equal(__x); } | |
2484 | }; | |
2485 | ||
2486 | _Vp _M_base = _Vp(); | |
2487 | ||
2488 | // XXX: _M_inner is "present only when !is_reference_v<_InnerRange>" | |
242b4fb7 | 2489 | [[no_unique_address]] |
8017d95c JW |
2490 | __detail::__maybe_empty_t<!is_reference_v<_InnerRange>, |
2491 | views::all_t<_InnerRange>> _M_inner; | |
cba9ef06 PP |
2492 | |
2493 | public: | |
2494 | join_view() = default; | |
2495 | ||
2496 | constexpr explicit | |
2497 | join_view(_Vp __base) | |
2498 | : _M_base(std::move(__base)) | |
2499 | { } | |
2500 | ||
cba9ef06 PP |
2501 | constexpr _Vp |
2502 | base() const& requires copy_constructible<_Vp> | |
2503 | { return _M_base; } | |
2504 | ||
2505 | constexpr _Vp | |
2506 | base() && | |
2507 | { return std::move(_M_base); } | |
2508 | ||
2509 | constexpr auto | |
2510 | begin() | |
2511 | { | |
242b4fb7 PP |
2512 | constexpr bool __use_const |
2513 | = (__detail::__simple_view<_Vp> | |
2514 | && is_reference_v<range_reference_t<_Vp>>); | |
2515 | return _Iterator<__use_const>{*this, ranges::begin(_M_base)}; | |
cba9ef06 PP |
2516 | } |
2517 | ||
2518 | constexpr auto | |
2519 | begin() const | |
2520 | requires input_range<const _Vp> | |
2521 | && is_reference_v<range_reference_t<const _Vp>> | |
2522 | { | |
2523 | return _Iterator<true>{*this, ranges::begin(_M_base)}; | |
2524 | } | |
2525 | ||
2526 | constexpr auto | |
2527 | end() | |
2528 | { | |
2529 | if constexpr (forward_range<_Vp> && is_reference_v<_InnerRange> | |
2530 | && forward_range<_InnerRange> | |
2531 | && common_range<_Vp> && common_range<_InnerRange>) | |
2532 | return _Iterator<__detail::__simple_view<_Vp>>{*this, | |
2533 | ranges::end(_M_base)}; | |
2534 | else | |
2535 | return _Sentinel<__detail::__simple_view<_Vp>>{*this}; | |
2536 | } | |
2537 | ||
2538 | constexpr auto | |
2539 | end() const | |
2540 | requires input_range<const _Vp> | |
2541 | && is_reference_v<range_reference_t<const _Vp>> | |
2542 | { | |
2543 | if constexpr (forward_range<const _Vp> | |
2544 | && is_reference_v<range_reference_t<const _Vp>> | |
2545 | && forward_range<range_reference_t<const _Vp>> | |
2546 | && common_range<const _Vp> | |
2547 | && common_range<range_reference_t<const _Vp>>) | |
2548 | return _Iterator<true>{*this, ranges::end(_M_base)}; | |
2549 | else | |
2550 | return _Sentinel<true>{*this}; | |
2551 | } | |
2552 | }; | |
2553 | ||
2554 | template<typename _Range> | |
aca60ecf | 2555 | explicit join_view(_Range&&) -> join_view<views::all_t<_Range>>; |
cba9ef06 PP |
2556 | |
2557 | namespace views | |
2558 | { | |
2559 | inline constexpr __adaptor::_RangeAdaptorClosure join | |
2560 | = [] <viewable_range _Range> (_Range&& __r) | |
2561 | { | |
2562 | return join_view{std::forward<_Range>(__r)}; | |
2563 | }; | |
2564 | } // namespace views | |
2565 | ||
2566 | namespace __detail | |
2567 | { | |
2568 | template<auto> | |
2569 | struct __require_constant; | |
2570 | ||
2571 | template<typename _Range> | |
2572 | concept __tiny_range = sized_range<_Range> | |
2573 | && requires | |
2574 | { typename __require_constant<remove_reference_t<_Range>::size()>; } | |
2575 | && (remove_reference_t<_Range>::size() <= 1); | |
2576 | } | |
2577 | ||
2578 | template<input_range _Vp, forward_range _Pattern> | |
2579 | requires view<_Vp> && view<_Pattern> | |
2580 | && indirectly_comparable<iterator_t<_Vp>, iterator_t<_Pattern>, | |
2581 | ranges::equal_to> | |
2582 | && (forward_range<_Vp> || __detail::__tiny_range<_Pattern>) | |
2583 | class split_view : public view_interface<split_view<_Vp, _Pattern>> | |
2584 | { | |
2585 | private: | |
2586 | template<bool _Const> | |
2587 | struct _InnerIter; | |
2588 | ||
2589 | template<bool _Const> | |
2590 | struct _OuterIter | |
2591 | { | |
2592 | private: | |
8017d95c JW |
2593 | using _Parent = __detail::__maybe_const_t<_Const, split_view>; |
2594 | using _Base = __detail::__maybe_const_t<_Const, _Vp>; | |
cba9ef06 PP |
2595 | |
2596 | constexpr bool | |
2597 | __at_end() const | |
2598 | { return _M_current == ranges::end(_M_parent->_M_base); } | |
2599 | ||
2600 | // XXX: [24.7.11.3.1] | |
2601 | // Many of the following specifications refer to the notional member | |
97a7c229 JW |
2602 | // current of outer-iterator. current is equivalent to current_ if |
2603 | // V models forward_range, and parent_->current_ otherwise. | |
cba9ef06 PP |
2604 | constexpr auto& |
2605 | __current() | |
2606 | { | |
2607 | if constexpr (forward_range<_Vp>) | |
2608 | return _M_current; | |
2609 | else | |
2610 | return _M_parent->_M_current; | |
2611 | } | |
2612 | ||
2613 | constexpr auto& | |
2614 | __current() const | |
2615 | { | |
2616 | if constexpr (forward_range<_Vp>) | |
2617 | return _M_current; | |
2618 | else | |
2619 | return _M_parent->_M_current; | |
2620 | } | |
2621 | ||
2622 | _Parent* _M_parent = nullptr; | |
2623 | ||
2624 | // XXX: _M_current is present only if "V models forward_range" | |
2625 | [[no_unique_address]] | |
8017d95c JW |
2626 | __detail::__maybe_empty_t<forward_range<_Vp>, |
2627 | iterator_t<_Base>> _M_current; | |
cba9ef06 PP |
2628 | |
2629 | public: | |
2630 | using iterator_concept = conditional_t<forward_range<_Base>, | |
2631 | forward_iterator_tag, | |
2632 | input_iterator_tag>; | |
2633 | using iterator_category = input_iterator_tag; | |
2634 | using difference_type = range_difference_t<_Base>; | |
2635 | ||
2636 | struct value_type : view_interface<value_type> | |
2637 | { | |
2638 | private: | |
2639 | _OuterIter _M_i = _OuterIter(); | |
2640 | ||
2641 | public: | |
2642 | value_type() = default; | |
2643 | ||
2644 | constexpr explicit | |
2645 | value_type(_OuterIter __i) | |
2646 | : _M_i(std::move(__i)) | |
2647 | { } | |
2648 | ||
2649 | constexpr _InnerIter<_Const> | |
2650 | begin() const | |
2651 | requires copyable<_OuterIter> | |
2652 | { return _InnerIter<_Const>{_M_i}; } | |
2653 | ||
2654 | constexpr _InnerIter<_Const> | |
2655 | begin() | |
2656 | requires (!copyable<_OuterIter>) | |
2657 | { return _InnerIter<_Const>{std::move(_M_i)}; } | |
2658 | ||
2659 | constexpr default_sentinel_t | |
2660 | end() const | |
2661 | { return default_sentinel; } | |
2662 | }; | |
2663 | ||
2664 | _OuterIter() = default; | |
2665 | ||
2666 | constexpr explicit | |
2667 | _OuterIter(_Parent& __parent) requires (!forward_range<_Base>) | |
2668 | : _M_parent(address(__parent)) | |
2669 | { } | |
2670 | ||
2671 | constexpr | |
2672 | _OuterIter(_Parent& __parent, iterator_t<_Base> __current) | |
2673 | requires forward_range<_Base> | |
2674 | : _M_parent(std::__addressof(__parent)), | |
2675 | _M_current(std::move(__current)) | |
2676 | { } | |
2677 | ||
2678 | constexpr | |
2679 | _OuterIter(_OuterIter<!_Const> __i) | |
2680 | requires _Const | |
242b4fb7 | 2681 | && convertible_to<iterator_t<_Vp>, iterator_t<_Base>> |
cba9ef06 PP |
2682 | : _M_parent(__i._M_parent), _M_current(std::move(__i._M_current)) |
2683 | { } | |
2684 | ||
2685 | constexpr value_type | |
2686 | operator*() const | |
2687 | { return value_type{*this}; } | |
2688 | ||
2689 | constexpr _OuterIter& | |
2690 | operator++() | |
2691 | { | |
2692 | const auto __end = ranges::end(_M_parent->_M_base); | |
2693 | if (_M_current == __end) | |
2694 | return *this; | |
2695 | const auto [__pbegin, __pend] = subrange{_M_parent->_M_pattern}; | |
2696 | if (__pbegin == __pend) | |
2697 | ++_M_current; | |
2698 | else | |
2699 | do | |
2700 | { | |
2701 | auto [__b, __p] | |
2702 | = __detail::mismatch(std::move(_M_current), __end, | |
2703 | __pbegin, __pend); | |
2704 | _M_current = std::move(__b); | |
2705 | if (__p == __pend) | |
2706 | break; | |
2707 | } while (++_M_current != __end); | |
2708 | return *this; | |
2709 | } | |
2710 | ||
2711 | constexpr decltype(auto) | |
2712 | operator++(int) | |
2713 | { | |
2714 | if constexpr (forward_range<_Base>) | |
2715 | { | |
2716 | auto __tmp = *this; | |
2717 | ++*this; | |
2718 | return __tmp; | |
2719 | } | |
2720 | else | |
2721 | ++*this; | |
2722 | } | |
2723 | ||
2724 | friend constexpr bool | |
2725 | operator==(const _OuterIter& __x, const _OuterIter& __y) | |
2726 | requires forward_range<_Base> | |
2727 | { return __x._M_current == __y._M_current; } | |
2728 | ||
2729 | friend constexpr bool | |
2730 | operator==(const _OuterIter& __x, default_sentinel_t) | |
2731 | { return __x.__at_end(); }; | |
2732 | ||
2733 | friend _InnerIter<_Const>; | |
2734 | }; | |
2735 | ||
2736 | template<bool _Const> | |
2737 | struct _InnerIter | |
2738 | { | |
2739 | private: | |
8017d95c | 2740 | using _Base = __detail::__maybe_const_t<_Const, _Vp>; |
cba9ef06 PP |
2741 | |
2742 | constexpr bool | |
2743 | __at_end() const | |
2744 | { | |
2745 | auto [__pcur, __pend] = subrange{_M_i._M_parent->_M_pattern}; | |
2746 | auto __end = ranges::end(_M_i._M_parent->_M_base); | |
2747 | if constexpr (__detail::__tiny_range<_Pattern>) | |
2748 | { | |
2749 | const auto& __cur = _M_i.__current(); | |
2750 | if (__cur == __end) | |
2751 | return true; | |
2752 | if (__pcur == __pend) | |
2753 | return _M_incremented; | |
2754 | return *__cur == *__pcur; | |
2755 | } | |
2756 | else | |
2757 | { | |
2758 | auto __cur = _M_i.__current(); | |
2759 | if (__cur == __end) | |
2760 | return true; | |
2761 | if (__pcur == __pend) | |
2762 | return _M_incremented; | |
2763 | do | |
2764 | { | |
2765 | if (*__cur != *__pcur) | |
2766 | return false; | |
2767 | if (++__pcur == __pend) | |
2768 | return true; | |
2769 | } while (++__cur != __end); | |
2770 | return false; | |
2771 | } | |
2772 | } | |
2773 | ||
2774 | static constexpr auto | |
2775 | _S_iter_cat() | |
2776 | { | |
a5b213dd JW |
2777 | using _Cat |
2778 | = typename iterator_traits<iterator_t<_Base>>::iterator_category; | |
cba9ef06 PP |
2779 | if constexpr (derived_from<_Cat, forward_iterator_tag>) |
2780 | return forward_iterator_tag{}; | |
2781 | else | |
2782 | return _Cat{}; | |
2783 | } | |
2784 | ||
2785 | static constexpr decltype(auto) | |
2786 | __iter_move(const _InnerIter& __i = {}) | |
2787 | noexcept(noexcept(ranges::iter_move(__i._M_i.__current()))) | |
2788 | { return ranges::iter_move(__i._M_i.__current()); } | |
2789 | ||
2790 | static constexpr void | |
2791 | __iter_swap(const _InnerIter& __x = {}, const _InnerIter& __y = {}) | |
2792 | noexcept(noexcept(ranges::iter_swap(__x._M_i.__current(), | |
2793 | __y._M_i.__current()))) | |
2794 | { ranges::iter_swap(__x._M_i.__current(), __y._M_i.__current()); } | |
2795 | ||
2796 | _OuterIter<_Const> _M_i = _OuterIter<_Const>(); | |
2797 | bool _M_incremented = false; | |
2798 | ||
2799 | public: | |
a5b213dd JW |
2800 | using iterator_concept |
2801 | = typename _OuterIter<_Const>::iterator_concept; | |
cba9ef06 PP |
2802 | using iterator_category = decltype(_S_iter_cat()); |
2803 | using value_type = range_value_t<_Base>; | |
2804 | using difference_type = range_difference_t<_Base>; | |
2805 | ||
2806 | _InnerIter() = default; | |
2807 | ||
2808 | constexpr explicit | |
2809 | _InnerIter(_OuterIter<_Const> __i) | |
2810 | : _M_i(std::move(__i)) | |
2811 | { } | |
2812 | ||
2813 | constexpr decltype(auto) | |
2814 | operator*() const | |
2815 | { return *_M_i._M_current; } | |
2816 | ||
2817 | constexpr _InnerIter& | |
2818 | operator++() | |
2819 | { | |
2820 | _M_incremented = true; | |
2821 | if constexpr (!forward_range<_Base>) | |
2822 | if constexpr (_Pattern::size() == 0) | |
2823 | return *this; | |
2824 | ++_M_i.__current(); | |
2825 | return *this; | |
2826 | } | |
2827 | ||
2828 | constexpr decltype(auto) | |
2829 | operator++(int) | |
2830 | { | |
2831 | if constexpr (forward_range<_Vp>) | |
2832 | { | |
2833 | auto __tmp = *this; | |
2834 | ++*this; | |
2835 | return __tmp; | |
2836 | } | |
2837 | else | |
2838 | ++*this; | |
2839 | } | |
2840 | ||
2841 | friend constexpr bool | |
2842 | operator==(const _InnerIter& __x, const _InnerIter& __y) | |
2843 | requires forward_range<_Base> | |
8ce13842 | 2844 | { return __x._M_i == __y._M_i; } |
cba9ef06 PP |
2845 | |
2846 | friend constexpr bool | |
2847 | operator==(const _InnerIter& __x, default_sentinel_t) | |
2848 | { return __x.__at_end(); } | |
2849 | ||
2850 | friend constexpr decltype(auto) | |
2851 | iter_move(const _InnerIter& __i) noexcept(noexcept(__iter_move())) | |
2852 | { return __iter_move(__i); } | |
2853 | ||
2854 | friend constexpr void | |
2855 | iter_swap(const _InnerIter& __x, const _InnerIter& __y) | |
2856 | noexcept(noexcept(__iter_swap())) | |
2857 | requires indirectly_swappable<iterator_t<_Base>> | |
2858 | { __iter_swap(__x, __y); } | |
2859 | }; | |
2860 | ||
2861 | _Vp _M_base = _Vp(); | |
2862 | _Pattern _M_pattern = _Pattern(); | |
2863 | ||
2864 | // XXX: _M_current is "present only if !forward_range<V>" | |
2865 | [[no_unique_address]] | |
8017d95c JW |
2866 | __detail::__maybe_empty_t<!forward_range<_Vp>, iterator_t<_Vp>> |
2867 | _M_current; | |
cba9ef06 PP |
2868 | |
2869 | ||
2870 | public: | |
2871 | split_view() = default; | |
2872 | ||
2873 | constexpr | |
2874 | split_view(_Vp __base, _Pattern __pattern) | |
2875 | : _M_base(std::move(__base)), _M_pattern(std::move(__pattern)) | |
2876 | { } | |
2877 | ||
cba9ef06 | 2878 | template<input_range _Range> |
aca60ecf | 2879 | requires constructible_from<_Vp, views::all_t<_Range>> |
cba9ef06 PP |
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&&) | |
aca60ecf | 2934 | -> split_view<views::all_t<_Range>, views::all_t<_Pred>>; |
cba9ef06 PP |
2935 | |
2936 | template<input_range _Range> | |
2937 | split_view(_Range&&, range_value_t<_Range>) | |
aca60ecf | 2938 | -> split_view<views::all_t<_Range>, single_view<range_value_t<_Range>>>; |
cba9ef06 PP |
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 | ||
4cc3b275 | 2983 | /* XXX: LWG 3280 didn't remove this constructor, but I think it should? |
cba9ef06 | 2984 | template<viewable_range _Range> |
4cc3b275 | 2985 | requires (!common_range<_Range>) |
aca60ecf | 2986 | && constructible_from<_Vp, views::all_t<_Range>> |
cba9ef06 PP |
2987 | constexpr explicit |
2988 | common_view(_Range&& __r) | |
2989 | : _M_base(views::all(std::forward<_Range>(__r))) | |
2990 | { } | |
4cc3b275 | 2991 | */ |
cba9ef06 PP |
2992 | |
2993 | constexpr _Vp | |
2994 | base() const& requires copy_constructible<_Vp> | |
2995 | { return _M_base; } | |
2996 | ||
2997 | constexpr _Vp | |
2998 | base() && | |
2999 | { return std::move(_M_base); } | |
3000 | ||
3001 | constexpr auto | |
3002 | begin() | |
3003 | { | |
3004 | if constexpr (random_access_range<_Vp> && sized_range<_Vp>) | |
3005 | return ranges::begin(_M_base); | |
3006 | else | |
3007 | return common_iterator<iterator_t<_Vp>, sentinel_t<_Vp>> | |
3008 | (ranges::begin(_M_base)); | |
3009 | } | |
3010 | ||
3011 | constexpr auto | |
3012 | begin() const requires range<const _Vp> | |
3013 | { | |
3014 | if constexpr (random_access_range<const _Vp> && sized_range<const _Vp>) | |
3015 | return ranges::begin(_M_base); | |
3016 | else | |
3017 | return common_iterator<iterator_t<const _Vp>, sentinel_t<const _Vp>> | |
3018 | (ranges::begin(_M_base)); | |
3019 | } | |
3020 | ||
3021 | constexpr auto | |
3022 | end() | |
3023 | { | |
3024 | if constexpr (random_access_range<_Vp> && sized_range<_Vp>) | |
3025 | return ranges::begin(_M_base) + ranges::size(_M_base); | |
3026 | else | |
3027 | return common_iterator<iterator_t<_Vp>, sentinel_t<_Vp>> | |
3028 | (ranges::end(_M_base)); | |
3029 | } | |
3030 | ||
3031 | constexpr auto | |
3032 | end() const requires range<const _Vp> | |
3033 | { | |
3034 | if constexpr (random_access_range<const _Vp> && sized_range<const _Vp>) | |
3035 | return ranges::begin(_M_base) + ranges::size(_M_base); | |
3036 | else | |
3037 | return common_iterator<iterator_t<const _Vp>, sentinel_t<const _Vp>> | |
3038 | (ranges::end(_M_base)); | |
3039 | } | |
3040 | ||
3041 | constexpr auto | |
3042 | size() requires sized_range<_Vp> | |
3043 | { return ranges::size(_M_base); } | |
3044 | ||
3045 | constexpr auto | |
3046 | size() const requires sized_range<const _Vp> | |
3047 | { return ranges::size(_M_base); } | |
3048 | }; | |
3049 | ||
3050 | template<typename _Range> | |
aca60ecf | 3051 | common_view(_Range&&) -> common_view<views::all_t<_Range>>; |
cba9ef06 PP |
3052 | |
3053 | namespace views | |
3054 | { | |
3055 | inline constexpr __adaptor::_RangeAdaptorClosure common | |
3056 | = [] <viewable_range _Range> (_Range&& __r) | |
3057 | { | |
3058 | if constexpr (common_range<_Range> | |
3059 | && requires { views::all(std::forward<_Range>(__r)); }) | |
3060 | return views::all(std::forward<_Range>(__r)); | |
3061 | else | |
3062 | return common_view{std::forward<_Range>(__r)}; | |
3063 | }; | |
3064 | ||
3065 | } // namespace views | |
3066 | ||
3067 | template<view _Vp> | |
3068 | requires bidirectional_range<_Vp> | |
3069 | class reverse_view : public view_interface<reverse_view<_Vp>> | |
3070 | { | |
3071 | private: | |
3072 | _Vp _M_base = _Vp(); | |
3073 | ||
3074 | public: | |
3075 | reverse_view() = default; | |
3076 | ||
3077 | constexpr explicit | |
3078 | reverse_view(_Vp __r) | |
3079 | : _M_base(std::move(__r)) | |
3080 | { } | |
3081 | ||
cba9ef06 PP |
3082 | constexpr _Vp |
3083 | base() const& requires copy_constructible<_Vp> | |
3084 | { return _M_base; } | |
3085 | ||
3086 | constexpr _Vp | |
3087 | base() && | |
3088 | { return std::move(_M_base); } | |
3089 | ||
3090 | constexpr reverse_iterator<iterator_t<_Vp>> | |
3091 | begin() | |
3092 | { | |
3093 | // XXX: we need to cache the result here as per [range.reverse.view] | |
3094 | return make_reverse_iterator(ranges::next(ranges::begin(_M_base), | |
3095 | ranges::end(_M_base))); | |
3096 | } | |
3097 | ||
3098 | constexpr auto | |
3099 | begin() requires common_range<_Vp> | |
3100 | { return make_reverse_iterator(ranges::end(_M_base)); } | |
3101 | ||
3102 | constexpr auto | |
3103 | begin() const requires common_range<const _Vp> | |
3104 | { return make_reverse_iterator(ranges::end(_M_base)); } | |
3105 | ||
3106 | constexpr reverse_iterator<iterator_t<_Vp>> | |
3107 | end() | |
3108 | { return make_reverse_iterator(ranges::begin(_M_base)); } | |
3109 | ||
3110 | constexpr auto | |
3111 | end() const requires common_range<const _Vp> | |
3112 | { return make_reverse_iterator(ranges::begin(_M_base)); } | |
3113 | ||
3114 | constexpr auto | |
3115 | size() requires sized_range<_Vp> | |
3116 | { return ranges::size(_M_base); } | |
3117 | ||
3118 | constexpr auto | |
3119 | size() const requires sized_range<const _Vp> | |
3120 | { return ranges::size(_M_base); } | |
3121 | }; | |
3122 | ||
3123 | template<typename _Range> | |
aca60ecf | 3124 | reverse_view(_Range&&) -> reverse_view<views::all_t<_Range>>; |
cba9ef06 PP |
3125 | |
3126 | namespace views | |
3127 | { | |
3128 | namespace __detail | |
3129 | { | |
3130 | template<typename> | |
3131 | inline constexpr bool __is_reversible_subrange = false; | |
3132 | ||
3133 | template<typename _Iter, subrange_kind _Kind> | |
3134 | inline constexpr bool | |
3135 | __is_reversible_subrange<subrange<reverse_iterator<_Iter>, | |
3136 | reverse_iterator<_Iter>, | |
3137 | _Kind>> = true; | |
3138 | ||
3139 | template<typename> | |
3140 | inline constexpr bool __is_reverse_view = false; | |
3141 | ||
3142 | template<typename _Vp> | |
3143 | inline constexpr bool __is_reverse_view<reverse_view<_Vp>> = true; | |
3144 | } | |
3145 | ||
3146 | inline constexpr __adaptor::_RangeAdaptorClosure reverse | |
3147 | = [] <viewable_range _Range> (_Range&& __r) | |
3148 | { | |
3149 | using _Tp = remove_cvref_t<_Range>; | |
3150 | if constexpr (__detail::__is_reverse_view<_Tp>) | |
3151 | return std::forward<_Range>(__r).base(); | |
3152 | else if constexpr (__detail::__is_reversible_subrange<_Tp>) | |
3153 | { | |
3154 | using _Iter = decltype(ranges::begin(__r).base()); | |
3155 | if constexpr (sized_range<_Tp>) | |
3156 | return subrange<_Iter, _Iter, subrange_kind::sized> | |
3157 | (__r.end().base(), __r.begin().base(), __r.size()); | |
3158 | else | |
3159 | return subrange<_Iter, _Iter, subrange_kind::unsized> | |
3160 | (__r.end().base(), __r.begin().base()); | |
3161 | } | |
3162 | else | |
3163 | return reverse_view{std::forward<_Range>(__r)}; | |
3164 | }; | |
3165 | } // namespace views | |
3166 | ||
3167 | namespace __detail | |
3168 | { | |
3169 | template<typename _Tp, size_t _Nm> | |
3170 | concept __has_tuple_element = requires(_Tp __t) | |
3171 | { | |
3172 | typename tuple_size<_Tp>::type; | |
3173 | requires _Nm < tuple_size_v<_Tp>; | |
3174 | typename tuple_element_t<_Nm, _Tp>; | |
cba9ef06 PP |
3175 | { std::get<_Nm>(__t) } |
3176 | -> convertible_to<const tuple_element_t<_Nm, _Tp>&>; | |
3177 | }; | |
3178 | } | |
3179 | ||
3180 | template<input_range _Vp, size_t _Nm> | |
3181 | requires view<_Vp> | |
3182 | && __detail::__has_tuple_element<range_value_t<_Vp>, _Nm> | |
3183 | && __detail::__has_tuple_element<remove_reference_t<range_reference_t<_Vp>>, | |
3184 | _Nm> | |
3185 | class elements_view : public view_interface<elements_view<_Vp, _Nm>> | |
3186 | { | |
3187 | public: | |
3188 | elements_view() = default; | |
3189 | ||
3190 | constexpr explicit | |
3191 | elements_view(_Vp base) | |
3192 | : _M_base(std::move(base)) | |
3193 | { } | |
3194 | ||
3195 | constexpr _Vp | |
3196 | base() const& requires copy_constructible<_Vp> | |
3197 | { return _M_base; } | |
3198 | ||
3199 | constexpr _Vp | |
3200 | base() && | |
3201 | { return std::move(_M_base); } | |
3202 | ||
3203 | constexpr auto | |
3204 | begin() requires (!__detail::__simple_view<_Vp>) | |
3205 | { return _Iterator<false>(ranges::begin(_M_base)); } | |
3206 | ||
3207 | constexpr auto | |
3208 | begin() const requires __detail::__simple_view<_Vp> | |
3209 | { return _Iterator<true>(ranges::begin(_M_base)); } | |
3210 | ||
3211 | constexpr auto | |
3212 | end() requires (!__detail::__simple_view<_Vp>) | |
3213 | { return ranges::end(_M_base); } | |
3214 | ||
3215 | constexpr auto | |
3216 | end() const requires __detail::__simple_view<_Vp> | |
3217 | { return ranges::end(_M_base); } | |
3218 | ||
3219 | constexpr auto | |
3220 | size() requires sized_range<_Vp> | |
3221 | { return ranges::size(_M_base); } | |
3222 | ||
3223 | constexpr auto | |
3224 | size() const requires sized_range<const _Vp> | |
3225 | { return ranges::size(_M_base); } | |
3226 | ||
3227 | private: | |
3228 | template<bool _Const> | |
3229 | struct _Iterator | |
3230 | { | |
8017d95c | 3231 | using _Base = __detail::__maybe_const_t<_Const, _Vp>; |
cba9ef06 | 3232 | |
7433536b | 3233 | iterator_t<_Base> _M_current = iterator_t<_Base>(); |
cba9ef06 PP |
3234 | |
3235 | friend _Iterator<!_Const>; | |
3236 | ||
3237 | public: | |
3238 | using iterator_category | |
3239 | = typename iterator_traits<iterator_t<_Base>>::iterator_category; | |
3240 | using value_type | |
3241 | = remove_cvref_t<tuple_element_t<_Nm, range_value_t<_Base>>>; | |
3242 | using difference_type = range_difference_t<_Base>; | |
3243 | ||
3244 | _Iterator() = default; | |
3245 | ||
3246 | constexpr explicit | |
3247 | _Iterator(iterator_t<_Base> current) | |
3248 | : _M_current(std::move(current)) | |
3249 | { } | |
3250 | ||
3251 | constexpr | |
3252 | _Iterator(_Iterator<!_Const> i) | |
3253 | requires _Const && convertible_to<iterator_t<_Vp>, iterator_t<_Base>> | |
3254 | : _M_current(std::move(i._M_current)) | |
3255 | { } | |
3256 | ||
3257 | constexpr iterator_t<_Base> | |
3258 | base() const& | |
3259 | requires copyable<iterator_t<_Base>> | |
3260 | { return _M_current; } | |
3261 | ||
3262 | constexpr iterator_t<_Base> | |
3263 | base() && | |
3264 | { return std::move(_M_current); } | |
3265 | ||
3266 | constexpr decltype(auto) | |
3267 | operator*() const | |
3268 | { return std::get<_Nm>(*_M_current); } | |
3269 | ||
3270 | constexpr _Iterator& | |
3271 | operator++() | |
3272 | { | |
3273 | ++_M_current; | |
3274 | return *this; | |
3275 | } | |
3276 | ||
3277 | constexpr void | |
3278 | operator++(int) requires (!forward_range<_Base>) | |
3279 | { ++_M_current; } | |
3280 | ||
3281 | constexpr _Iterator | |
3282 | operator++(int) requires forward_range<_Base> | |
3283 | { | |
3284 | auto __tmp = *this; | |
3285 | ++_M_current; | |
3286 | return __tmp; | |
3287 | } | |
3288 | ||
3289 | constexpr _Iterator& | |
3290 | operator--() requires bidirectional_range<_Base> | |
3291 | { | |
3292 | --_M_current; | |
3293 | return *this; | |
3294 | } | |
3295 | ||
3296 | constexpr _Iterator | |
3297 | operator--(int) requires bidirectional_range<_Base> | |
3298 | { | |
3299 | auto __tmp = *this; | |
3300 | --_M_current; | |
3301 | return __tmp; | |
3302 | } | |
3303 | ||
3304 | constexpr _Iterator& | |
3305 | operator+=(difference_type __n) | |
3306 | requires random_access_range<_Base> | |
3307 | { | |
3308 | _M_current += __n; | |
3309 | return *this; | |
3310 | } | |
3311 | ||
3312 | constexpr _Iterator& | |
3313 | operator-=(difference_type __n) | |
3314 | requires random_access_range<_Base> | |
3315 | { | |
3316 | _M_current -= __n; | |
3317 | return *this; | |
3318 | } | |
3319 | ||
3320 | constexpr decltype(auto) | |
3321 | operator[](difference_type __n) const | |
3322 | requires random_access_range<_Base> | |
3323 | { return std::get<_Nm>(*(_M_current + __n)); } | |
3324 | ||
3325 | friend constexpr bool | |
3326 | operator==(const _Iterator& __x, const _Iterator& __y) | |
3327 | requires equality_comparable<iterator_t<_Base>> | |
3328 | { return __x._M_current == __y._M_current; } | |
3329 | ||
3330 | friend constexpr bool | |
3331 | operator==(const _Iterator& __x, const sentinel_t<_Base>& __y) | |
3332 | { return __x._M_current == __y; } | |
3333 | ||
3334 | friend constexpr bool | |
3335 | operator<(const _Iterator& __x, const _Iterator& __y) | |
3336 | requires random_access_range<_Base> | |
3337 | { return __x._M_current < __y._M_current; } | |
3338 | ||
3339 | friend constexpr bool | |
3340 | operator>(const _Iterator& __x, const _Iterator& __y) | |
3341 | requires random_access_range<_Base> | |
3342 | { return __y._M_current < __x._M_current; } | |
3343 | ||
3344 | friend constexpr bool | |
3345 | operator<=(const _Iterator& __x, const _Iterator& __y) | |
3346 | requires random_access_range<_Base> | |
3347 | { return !(__y._M_current > __x._M_current); } | |
3348 | ||
3349 | friend constexpr bool | |
3350 | operator>=(const _Iterator& __x, const _Iterator& __y) | |
3351 | requires random_access_range<_Base> | |
3352 | { return !(__x._M_current > __y._M_current); } | |
3353 | ||
3354 | #ifdef __cpp_lib_three_way_comparison | |
3355 | friend constexpr auto | |
3356 | operator<=>(const _Iterator& __x, const _Iterator& __y) | |
3357 | requires random_access_range<_Base> | |
3358 | && three_way_comparable<iterator_t<_Base>> | |
3359 | { return __x._M_current <=> __y._M_current; } | |
3360 | #endif | |
3361 | ||
3362 | friend constexpr _Iterator | |
3363 | operator+(const _Iterator& __x, difference_type __y) | |
3364 | requires random_access_range<_Base> | |
3365 | { return _Iterator{__x} += __y; } | |
3366 | ||
3367 | friend constexpr _Iterator | |
3368 | operator+(difference_type __x, const _Iterator& __y) | |
3369 | requires random_access_range<_Base> | |
3370 | { return __y + __x; } | |
3371 | ||
3372 | friend constexpr _Iterator | |
3373 | operator-(const _Iterator& __x, difference_type __y) | |
3374 | requires random_access_range<_Base> | |
3375 | { return _Iterator{__x} -= __y; } | |
3376 | ||
3377 | friend constexpr difference_type | |
3378 | operator-(const _Iterator& __x, const _Iterator& __y) | |
3379 | requires random_access_range<_Base> | |
3380 | { return __x._M_current - __y._M_current; } | |
3381 | ||
3382 | friend constexpr difference_type | |
3383 | operator-(const _Iterator<_Const>& __x, const sentinel_t<_Base>& __y) | |
3384 | requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base>> | |
3385 | { return __x._M_current - __y; } | |
3386 | ||
3387 | friend constexpr difference_type | |
3388 | operator-(const sentinel_t<_Base>& __x, const _Iterator<_Const>& __y) | |
3389 | requires sized_sentinel_for<sentinel_t<_Base>, iterator_t<_Base>> | |
3390 | { return -(__y - __x); } | |
3391 | }; | |
3392 | ||
3393 | _Vp _M_base = _Vp(); | |
3394 | }; | |
3395 | ||
3396 | template<typename _Range> | |
aca60ecf | 3397 | using keys_view = elements_view<views::all_t<_Range>, 0>; |
cba9ef06 PP |
3398 | |
3399 | template<typename _Range> | |
aca60ecf | 3400 | using values_view = elements_view<views::all_t<_Range>, 1>; |
cba9ef06 PP |
3401 | |
3402 | namespace views | |
3403 | { | |
3404 | template<size_t _Nm> | |
3405 | inline constexpr __adaptor::_RangeAdaptorClosure elements | |
3406 | = [] <viewable_range _Range> (_Range&& __r) | |
3407 | { | |
aca60ecf JW |
3408 | using _El = elements_view<views::all_t<_Range>, _Nm>; |
3409 | return _El{std::forward<_Range>(__r)}; | |
cba9ef06 PP |
3410 | }; |
3411 | ||
3412 | inline constexpr __adaptor::_RangeAdaptorClosure keys = elements<0>; | |
3413 | inline constexpr __adaptor::_RangeAdaptorClosure values = elements<1>; | |
3414 | } // namespace views | |
3415 | ||
3416 | } // namespace ranges | |
3417 | ||
3418 | namespace views = ranges::views; | |
3419 | ||
3420 | template<typename _Iter, typename _Sent, ranges::subrange_kind _Kind> | |
3421 | struct tuple_size<ranges::subrange<_Iter, _Sent, _Kind>> | |
3422 | : integral_constant<size_t, 2> | |
3423 | { }; | |
3424 | ||
3425 | template<typename _Iter, typename _Sent, ranges::subrange_kind _Kind> | |
3426 | struct tuple_element<0, ranges::subrange<_Iter, _Sent, _Kind>> | |
3427 | { using type = _Iter; }; | |
3428 | ||
3429 | template<typename _Iter, typename _Sent, ranges::subrange_kind _Kind> | |
3430 | struct tuple_element<1, ranges::subrange<_Iter, _Sent, _Kind>> | |
3431 | { using type = _Sent; }; | |
3432 | ||
fa89adaa JW |
3433 | template<typename _Iter, typename _Sent, ranges::subrange_kind _Kind> |
3434 | struct tuple_element<0, const 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, const 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 */ |