2 //===----------------------------------------------------------------------===//
4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5 // See https://llvm.org/LICENSE.txt for license information.
6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
8 //===----------------------------------------------------------------------===//
10 #ifndef _LIBCPP_RANGES
11 #define _LIBCPP_RANGES
15 #include <compare> // see [compare.syn]
16 #include <initializer_list> // see [initializer.list.syn]
17 #include <iterator> // see [iterator.synopsis]
19 namespace std::ranges {
20 inline namespace unspecified {
21 // [range.access], range access
22 inline constexpr unspecified begin = unspecified;
23 inline constexpr unspecified end = unspecified;
24 inline constexpr unspecified cbegin = unspecified;
25 inline constexpr unspecified cend = unspecified;
27 inline constexpr unspecified size = unspecified;
28 inline constexpr unspecified ssize = unspecified;
31 // [range.range], ranges
33 concept range = see below;
36 inline constexpr bool enable_borrowed_range = false;
39 using iterator_t = decltype(ranges::begin(declval<T&>()));
41 using sentinel_t = decltype(ranges::end(declval<R&>()));
43 using range_difference_t = iter_difference_t<iterator_t<R>>;
44 template<sized_range R>
45 using range_size_t = decltype(ranges::size(declval<R&>()));
47 using range_value_t = iter_value_t<iterator_t<R>>;
49 using range_reference_t = iter_reference_t<iterator_t<R>>;
51 using range_rvalue_reference_t = iter_rvalue_reference_t<iterator_t<R>>;
53 using range_common_reference_t = iter_common_reference_t<iterator_t<R>>;
55 // [range.sized], sized ranges
57 inline constexpr bool disable_sized_range = false;
60 concept sized_range = ...;
62 // [range.view], views
64 inline constexpr bool enable_view = ...;
71 // [range.refinements], other range refinements
72 template<class R, class T>
73 concept output_range = see below;
76 concept input_range = see below;
79 concept forward_range = see below;
82 concept bidirectional_range = see below;
85 concept random_access_range = see below;
88 concept contiguous_range = see below;
91 concept common_range = see below;
94 concept viewable_range = see below;
96 // [view.interface], class template view_interface
98 requires is_class_v<D> && same_as<D, remove_cv_t<D>>
101 // [range.subrange], sub-ranges
102 enum class subrange_kind : bool { unsized, sized };
104 template<input_or_output_iterator I, sentinel_for<I> S = I, subrange_kind K = see below>
105 requires (K == subrange_kind::sized || !sized_sentinel_for<S, I>)
108 template<class I, class S, subrange_kind K>
109 inline constexpr bool enable_borrowed_range<subrange<I, S, K>> = true;
111 // [range.dangling], dangling iterator handling
115 using borrowed_iterator_t = see below;
118 using borrowed_subrange_t = see below;
120 // [range.elements], elements view
121 template<input_range V, size_t N>
125 template<class T, size_t N>
126 inline constexpr bool enable_borrowed_range<elements_view<T, N>> =
127 enable_borrowed_range<T>;
130 using keys_view = elements_view<R, 0>;
132 using values_view = elements_view<R, 1>;
136 inline constexpr unspecified elements = unspecified;
137 inline constexpr auto keys = elements<0>;
138 inline constexpr auto values = elements<1>;
141 // [range.utility.conv], range conversions
142 template<class C, input_range R, class... Args> requires (!view<C>)
143 constexpr C to(R&& r, Args&&... args); // Since C++23
144 template<template<class...> class C, input_range R, class... Args>
145 constexpr auto to(R&& r, Args&&... args); // Since C++23
146 template<class C, class... Args> requires (!view<C>)
147 constexpr auto to(Args&&... args); // Since C++23
148 template<template<class...> class C, class... Args>
149 constexpr auto to(Args&&... args); // Since C++23
151 // [range.empty], empty view
153 requires is_object_v<T>
157 inline constexpr bool enable_borrowed_range<empty_view<T>> = true;
161 inline constexpr empty_view<T> empty{};
164 // [range.all], all view
166 inline constexpr unspecified all = unspecified;
168 template<viewable_range R>
169 using all_t = decltype(all(declval<R>()));
173 requires is_object_v<R>
177 inline constexpr bool enable_borrowed_range<ref_view<T>> = true;
184 inline constexpr bool enable_borrowed_range<owning_view<T>> = enable_borrowed_range<T>;
186 // [range.filter], filter view
187 template<input_range V, indirect_unary_predicate<iterator_t<V>> Pred>
188 requires view<V> && is_object_v<Pred>
192 inline constexpr unspecified filter = unspecified;
195 // [range.drop], drop view
200 inline constexpr bool enable_borrowed_range<drop_view<T>> = enable_borrowed_range<T>;
202 // [range.drop.while], drop while view
203 template<view V, class Pred>
204 requires input_range<V> && is_object_v<Pred> &&
205 indirect_unary_predicate<const Pred, iterator_t<V>>
206 class drop_while_view;
208 template<class T, class Pred>
209 inline constexpr bool enable_borrowed_range<drop_while_view<T, Pred>> =
210 enable_borrowed_range<T>;
212 namespace views { inline constexpr unspecified drop_while = unspecified; }
214 // [range.transform], transform view
215 template<input_range V, copy_constructible F>
216 requires view<V> && is_object_v<F> &&
217 regular_invocable<F&, range_reference_t<V>> &&
218 can-reference<invoke_result_t<F&, range_reference_t<V>>>
219 class transform_view;
221 // [range.counted], counted view
222 namespace views { inline constexpr unspecified counted = unspecified; }
224 // [range.common], common view
226 requires (!common_range<V> && copyable<iterator_t<V>>)
229 // [range.reverse], reverse view
231 requires bidirectional_range<V>
235 inline constexpr bool enable_borrowed_range<reverse_view<T>> = enable_borrowed_range<T>;
238 inline constexpr bool enable_borrowed_range<common_view<T>> = enable_borrowed_range<T>;
240 // [range.take], take view
241 template<view> class take_view;
244 inline constexpr bool enable_borrowed_range<take_view<T>> = enable_borrowed_range<T>;
246 // [range.take.while], take while view
247 template<view V, class Pred>
248 requires input_range<V> && is_object_v<Pred> &&
249 indirect_unary_predicate<const Pred, iterator_t<V>>
250 class take_while_view;
252 namespace views { inline constexpr unspecified take_while = unspecified; }
254 template<copy_constructible T>
255 requires is_object_v<T>
258 template<weakly_incrementable W, semiregular Bound = unreachable_sentinel_t>
259 requires weakly-equality-comparable-with<W, Bound> && copyable<W>
262 template<class W, class Bound>
263 inline constexpr bool enable_borrowed_range<iota_view<W, Bound>> = true;
265 // [range.repeat], repeat view
267 concept integer-like-with-usable-difference-type = // exposition only
268 is-signed-integer-like<T> || (is-integer-like<T> && weakly_incrementable<T>);
270 template<move_constructible T, semiregular Bound = unreachable_sentinel_t>
271 requires (is_object_v<T> && same_as<T, remove_cv_t<T>> &&
272 (integer-like-with-usable-difference-type<Bound> ||
273 same_as<Bound, unreachable_sentinel_t>))
276 namespace views { inline constexpr unspecified repeat = unspecified; }
278 // [range.join], join view
279 template<input_range V>
280 requires view<V> && input_range<range_reference_t<V>>
283 // [range.lazy.split], lazy split view
285 concept tiny-range = see below; // exposition only
287 template<input_range V, forward_range Pattern>
288 requires view<V> && view<Pattern> &&
289 indirectly_comparable<iterator_t<V>, iterator_t<Pattern>, ranges::equal_to> &&
290 (forward_range<V> || tiny-range<Pattern>)
291 class lazy_split_view;
293 // [range.split], split view
294 template<forward_range V, forward_range Pattern>
295 requires view<V> && view<Pattern> &&
296 indirectly_comparable<iterator_t<V>, iterator_t<Pattern>, ranges::equal_to>
300 inline constexpr unspecified lazy_split = unspecified;
301 inline constexpr unspecified split = unspecified;
304 // [range.istream], istream view
305 template<movable Val, class CharT, class Traits = char_traits<CharT>>
307 class basic_istream_view;
310 using istream_view = basic_istream_view<Val, char>;
313 using wistream_view = basic_istream_view<Val, wchar_t>;
315 namespace views { template<class T> inline constexpr unspecified istream = unspecified; }
317 // [range.zip], zip view
318 template<input_range... Views>
319 requires (view<Views> && ...) && (sizeof...(Views) > 0)
320 class zip_view; // C++23
322 template<class... Views>
323 inline constexpr bool enable_borrowed_range<zip_view<Views...>> = // C++23
324 (enable_borrowed_range<Views> && ...);
326 namespace views { inline constexpr unspecified zip = unspecified; } // C++23
330 requires input_range<V>
331 class as_rvalue_view; // C++23
333 namespace views { inline constexpr unspecified as_rvalue ) unspecified; } // C++23
336 template<forward_range V, indirect_binary_predicate<iterator_t<V>, iterator_t<V>> Pred>
337 requires view<V> && is_object_v<Pred>
338 class chunk_by_view; // C++23
340 namespace views { inline constexpr unspecified chunk_by = unspecified; } // C++23
344 namespace views = ranges::views;
346 template<class T> struct tuple_size;
347 template<size_t I, class T> struct tuple_element;
349 template<class I, class S, ranges::subrange_kind K>
350 struct tuple_size<ranges::subrange<I, S, K>>
351 : integral_constant<size_t, 2> {};
353 template<class I, class S, ranges::subrange_kind K>
354 struct tuple_element<0, ranges::subrange<I, S, K>> {
358 template<class I, class S, ranges::subrange_kind K>
359 struct tuple_element<1, ranges::subrange<I, S, K>> {
363 template<class I, class S, ranges::subrange_kind K>
364 struct tuple_element<0, const ranges::subrange<I, S, K>> {
368 template<class I, class S, ranges::subrange_kind K>
369 struct tuple_element<1, const ranges::subrange<I, S, K>> {
373 struct from_range_t { explicit from_range_t() = default; }; // Since C++23
374 inline constexpr from_range_t from_range{}; // Since C++23
378 #include <__assert> // all public C++ headers provide the assertion handler
380 #include <__ranges/access.h>
381 #include <__ranges/all.h>
382 #include <__ranges/as_rvalue_view.h>
383 #include <__ranges/chunk_by_view.h>
384 #include <__ranges/common_view.h>
385 #include <__ranges/concepts.h>
386 #include <__ranges/counted.h>
387 #include <__ranges/dangling.h>
388 #include <__ranges/data.h>
389 #include <__ranges/drop_view.h>
390 #include <__ranges/drop_while_view.h>
391 #include <__ranges/elements_view.h>
392 #include <__ranges/empty.h>
393 #include <__ranges/empty_view.h>
394 #include <__ranges/enable_borrowed_range.h>
395 #include <__ranges/enable_view.h>
396 #include <__ranges/filter_view.h>
397 #include <__ranges/from_range.h>
398 #include <__ranges/iota_view.h>
399 #include <__ranges/join_view.h>
400 #include <__ranges/lazy_split_view.h>
401 #include <__ranges/rbegin.h>
402 #include <__ranges/ref_view.h>
403 #include <__ranges/rend.h>
404 #include <__ranges/repeat_view.h>
405 #include <__ranges/reverse_view.h>
406 #include <__ranges/single_view.h>
407 #include <__ranges/size.h>
408 #include <__ranges/split_view.h>
409 #include <__ranges/subrange.h>
410 #include <__ranges/take_view.h>
411 #include <__ranges/take_while_view.h>
412 #include <__ranges/to.h>
413 #include <__ranges/transform_view.h>
414 #include <__ranges/view_interface.h>
415 #include <__ranges/views.h>
416 #include <__ranges/zip_view.h>
419 #if !defined(_LIBCPP_HAS_NO_LOCALIZATION)
420 # include <__ranges/istream_view.h>
423 // standard-mandated includes
427 #include <initializer_list>
431 #include <__tuple/tuple_element.h>
432 #include <__tuple/tuple_size.h>
434 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
435 # pragma GCC system_header
438 #if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
441 # include <type_traits>
444 #endif // _LIBCPP_RANGES