xref: /aosp_15_r20/external/cronet/third_party/libc++/src/include/memory (revision 6777b5387eb2ff775bb5750e3f5d96f37fb7352b)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_MEMORY
11#define _LIBCPP_MEMORY
12
13// clang-format off
14
15/*
16    memory synopsis
17
18namespace std
19{
20
21struct allocator_arg_t { };
22inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();
23
24template <class T, class Alloc> struct uses_allocator;
25
26template <class Ptr>
27struct pointer_traits
28{
29    typedef Ptr pointer;
30    typedef <details> element_type;
31    typedef <details> difference_type;
32
33    template <class U> using rebind = <details>;
34
35    static pointer pointer_to(<details>);
36};
37
38template <class T>
39struct pointer_traits<T*>
40{
41    typedef T* pointer;
42    typedef T element_type;
43    typedef ptrdiff_t difference_type;
44
45    template <class U> using rebind = U*;
46
47    static pointer pointer_to(<details>) noexcept; // constexpr in C++20
48};
49
50template <class T> constexpr T* to_address(T* p) noexcept; // C++20
51template <class Ptr> constexpr auto to_address(const Ptr& p) noexcept; // C++20
52
53template <class Alloc>
54struct allocator_traits
55{
56    typedef Alloc                        allocator_type;
57    typedef typename allocator_type::value_type
58                                         value_type;
59
60    typedef Alloc::pointer | value_type* pointer;
61    typedef Alloc::const_pointer
62          | pointer_traits<pointer>::rebind<const value_type>
63                                         const_pointer;
64    typedef Alloc::void_pointer
65          | pointer_traits<pointer>::rebind<void>
66                                         void_pointer;
67    typedef Alloc::const_void_pointer
68          | pointer_traits<pointer>::rebind<const void>
69                                         const_void_pointer;
70    typedef Alloc::difference_type
71          | pointer_traits<pointer>::difference_type
72                                         difference_type;
73    typedef Alloc::size_type
74          | make_unsigned<difference_type>::type
75                                         size_type;
76    typedef Alloc::propagate_on_container_copy_assignment
77          | false_type                   propagate_on_container_copy_assignment;
78    typedef Alloc::propagate_on_container_move_assignment
79          | false_type                   propagate_on_container_move_assignment;
80    typedef Alloc::propagate_on_container_swap
81          | false_type                   propagate_on_container_swap;
82    typedef Alloc::is_always_equal
83          | is_empty                     is_always_equal;
84
85    template <class T> using rebind_alloc  = Alloc::rebind<T>::other | Alloc<T, Args...>;
86    template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
87
88    static pointer allocate(allocator_type& a, size_type n);                          // constexpr and [[nodiscard]] in C++20
89    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint); // constexpr and [[nodiscard]] in C++20
90
91    [[nodiscard]] static constexpr allocation_result<pointer, size_type>
92      allocate_at_least(Alloc& a, size_type n);                                 // Since C++23
93
94    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept; // constexpr in C++20
95
96    template <class T, class... Args>
97    static void construct(allocator_type& a, T* p, Args&&... args); // constexpr in C++20
98
99    template <class T>
100    static void destroy(allocator_type& a, T* p); // constexpr in C++20
101
102    static size_type max_size(const allocator_type& a); // noexcept in C++14, constexpr in C++20
103    static allocator_type select_on_container_copy_construction(const allocator_type& a); // constexpr in C++20
104};
105
106template<class Pointer, class SizeType = size_t>
107struct allocation_result {
108    Pointer ptr;
109    SizeType count;
110}; // Since C++23
111
112template <>
113class allocator<void> // removed in C++20
114{
115public:
116    typedef void*                                 pointer;
117    typedef const void*                           const_pointer;
118    typedef void                                  value_type;
119
120    template <class _Up> struct rebind {typedef allocator<_Up> other;};
121};
122
123template <class T>
124class allocator
125{
126public:
127    typedef size_t    size_type;
128    typedef ptrdiff_t difference_type;
129    typedef T*        pointer;                           // deprecated in C++17, removed in C++20
130    typedef const T*  const_pointer;                     // deprecated in C++17, removed in C++20
131    typedef typename add_lvalue_reference<T>::type
132                      reference;                         // deprecated in C++17, removed in C++20
133    typedef typename add_lvalue_reference<const T>::type
134                      const_reference;                   // deprecated in C++17, removed in C++20
135
136    typedef T         value_type;
137
138    template <class U> struct rebind {typedef allocator<U> other;}; // deprecated in C++17, removed in C++20
139
140    typedef true_type propagate_on_container_move_assignment;
141    typedef true_type is_always_equal;                   // Deprecated in C++23, removed in C++26
142
143    constexpr allocator() noexcept;                      // constexpr in C++20
144    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
145    template <class U>
146      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
147    ~allocator();                                        // constexpr in C++20
148    pointer address(reference x) const noexcept;             // deprecated in C++17, removed in C++20
149    const_pointer address(const_reference x) const noexcept; // deprecated in C++17, removed in C++20
150    T* allocate(size_t n, const void* hint);          // deprecated in C++17, removed in C++20
151    T* allocate(size_t n);                              // constexpr in C++20
152    void deallocate(T* p, size_t n) noexcept;           // constexpr in C++20
153    size_type max_size() const noexcept;              // deprecated in C++17, removed in C++20
154    template<class U, class... Args>
155        void construct(U* p, Args&&... args);         // deprecated in C++17, removed in C++20
156    template <class U>
157        void destroy(U* p);                           // deprecated in C++17, removed in C++20
158};
159
160template <class T, class U>
161bool operator==(const allocator<T>&, const allocator<U>&) noexcept; // constexpr in C++20
162
163template <class T, class U>
164bool operator!=(const allocator<T>&, const allocator<U>&) noexcept; // removed in C++20
165
166template <class OutputIterator, class T>
167class raw_storage_iterator // deprecated in C++17, removed in C++20
168    : public iterator<output_iterator_tag, void, void, void, void> // until C++17
169{
170public:
171    typedef output_iterator_tag iterator_category;
172    typedef void                value_type;
173    typedef void                difference_type; // until C++20
174    typedef ptrdiff_t           difference_type; // since C++20
175    typedef void                pointer;
176    typedef void                reference;
177
178    explicit raw_storage_iterator(OutputIterator x);
179    raw_storage_iterator& operator*();
180    raw_storage_iterator& operator=(const T& element);
181    raw_storage_iterator& operator++();
182    raw_storage_iterator  operator++(int);
183};
184
185template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
186template <class T> void               return_temporary_buffer(T* p) noexcept;
187
188template <class T> T* addressof(T& r) noexcept;
189template <class T> T* addressof(const T&& r) noexcept = delete;
190
191template <class InputIterator, class ForwardIterator>
192ForwardIterator
193uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
194
195namespace ranges {
196
197template<class InputIterator, class OutputIterator>
198using uninitialized_copy_result = in_out_result<InputIterator, OutputIterator>; // since C++20
199
200template<input_iterator InputIterator, sentinel-for<InputIterator> Sentinel1, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel2>
201  requires constructible_from<iter_value_t<OutputIterator>, iter_reference_t<InputIterator>>
202uninitialized_copy_result<InputIterator, OutputIterator>
203uninitialized_copy(InputIterator ifirst, Sentinel1 ilast, OutputIterator ofirst, Sentinel2 olast); // since C++20
204
205template<input_range InputRange, nothrow-forward-range OutputRange>
206  requires constructible_from<range_value_t<OutputRange>, range_reference_t<InputRange>>
207uninitialized_copy_result<borrowed_iterator_t<InputRange>, borrowed_iterator_t<OutputRange>>
208uninitialized_copy(InputRange&& in_range, OutputRange&& out_range); // since C++20
209
210}
211
212template <class InputIterator, class Size, class ForwardIterator>
213ForwardIterator
214uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
215
216namespace ranges {
217
218template<class InputIterator, class OutputIterator>
219using uninitialized_copy_n_result = in_out_result<InputIterator, OutputIterator>; // since C++20
220
221template<input_iterator InputIterator, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel>
222  requires constructible_from<iter_value_t<OutputIterator>, iter_reference_t<InputIterator>>
223uninitialized_copy_n_result<InputIterator, OutputIterator>
224uninitialized_copy_n(InputIterator ifirst, iter_difference_t<InputIterator> n, OutputIterator ofirst, Sentinel olast); // since C++20
225
226}
227
228template <class ForwardIterator, class T>
229void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
230
231namespace ranges {
232
233template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel, class T>
234  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
235ForwardIterator uninitialized_fill(ForwardIterator first, Sentinel last, const T& x); // since C++20
236
237template <nothrow-forward-range ForwardRange, class T>
238  requires constructible_from<range_value_t<ForwardRange>, const T&>
239borrowed_iterator_t<ForwardRange> uninitialized_fill(ForwardRange&& range, const T& x); // since C++20
240
241}
242
243template <class ForwardIterator, class Size, class T>
244ForwardIterator
245uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
246
247namespace ranges {
248
249template <nothrow-forward-iterator ForwardIterator, class T>
250  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
251ForwardIterator uninitialized_fill_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
252
253}
254
255template <class T, class ...Args>
256constexpr T* construct_at(T* location, Args&& ...args); // since C++20
257
258namespace ranges {
259  template<class T, class... Args>
260    constexpr T* construct_at(T* location, Args&&... args); // since C++20
261}
262
263template <class T>
264void destroy_at(T* location); // constexpr in C++20
265
266namespace ranges {
267  template<destructible T>
268    constexpr void destroy_at(T* location) noexcept; // since C++20
269}
270
271template <class ForwardIterator>
272void destroy(ForwardIterator first, ForwardIterator last); // constexpr in C++20
273
274namespace ranges {
275  template<nothrow-input-iterator InputIterator, nothrow-sentinel-for<InputIterator> Sentinel>
276    requires destructible<iter_value_t<InputIterator>>
277    constexpr InputIterator destroy(InputIterator first, Sentinel last) noexcept; // since C++20
278  template<nothrow-input-range InputRange>
279    requires destructible<range_value_t<InputRange>>
280    constexpr borrowed_iterator_t<InputRange> destroy(InputRange&& range) noexcept; // since C++20
281}
282
283template <class ForwardIterator, class Size>
284ForwardIterator destroy_n(ForwardIterator first, Size n); // constexpr in C++20
285
286namespace ranges {
287  template<nothrow-input-iterator InputIterator>
288    requires destructible<iter_value_t<InputIterator>>
289    constexpr InputIterator destroy_n(InputIterator first, iter_difference_t<InputIterator> n) noexcept; // since C++20
290}
291
292template <class InputIterator, class ForwardIterator>
293 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
294
295namespace ranges {
296
297template<class InputIterator, class OutputIterator>
298using uninitialized_move_result = in_out_result<InputIterator, OutputIterator>; // since C++20
299
300template <input_iterator InputIterator, sentinel_for<InputIterator> Sentinel1, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<O> Sentinel2>
301  requires constructible_from<iter_value_t<OutputIterator>, iter_rvalue_reference_t<InputIterator>>
302uninitialized_move_result<InputIterator, OutputIterator>
303uninitialized_move(InputIterator ifirst, Sentinel1 ilast, OutputIterator ofirst, Sentinel2 olast); // since C++20
304
305template<input_range InputRange, nothrow-forward-range OutputRange>
306  requires constructible_from<range_value_t<OutputRange>, range_rvalue_reference_t<InputRange>>
307uninitialized_move_result<borrowed_iterator_t<InputRange>, borrowed_iterator_t<OutputRange>>
308uninitialized_move(InputRange&& in_range, OutputRange&& out_range); // since C++20
309
310}
311
312template <class InputIterator, class Size, class ForwardIterator>
313 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
314
315namespace ranges {
316
317template<class InputIterator, class OutputIterator>
318using uninitialized_move_n_result = in_out_result<InputIterator, OutputIterator>; // since C++20
319
320template<input_iterator InputIterator, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel>
321  requires constructible_from<iter_value_t<OutputIterator>, iter_rvalue_reference_t<InputIterator>>
322uninitialized_move_n_result<InputIterator, OutputIterator>
323uninitialized_move_n(InputIterator ifirst, iter_difference_t<InputIterator> n, OutputIterator ofirst, Sentinel olast); // since C++20
324
325}
326
327template <class ForwardIterator>
328 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
329
330namespace ranges {
331
332template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
333  requires default_initializable<iter_value_t<ForwardIterator>>
334 ForwardIterator uninitialized_value_construct(ForwardIterator first, Sentinel last); // since C++20
335
336template <nothrow-forward-range ForwardRange>
337  requires default_initializable<range_value_t<ForwardRange>>
338 borrowed_iterator_t<ForwardRange> uninitialized_value_construct(ForwardRange&& r); // since C++20
339
340}
341
342template <class ForwardIterator, class Size>
343 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
344
345namespace ranges {
346
347template <nothrow-forward-iterator ForwardIterator>
348  requires default_initializable<iter_value_t<ForwardIterator>>
349 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
350
351}
352
353template <class ForwardIterator>
354 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
355
356namespace ranges {
357
358template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
359  requires default_initializable<iter_value_t<ForwardIterator>>
360 ForwardIterator uninitialized_default_construct(ForwardIterator first, Sentinel last); // since C++20
361
362template <nothrow-forward-range ForwardRange>
363  requires default_initializable<range_value_t<ForwardRange>>
364 borrowed_iterator_t<ForwardRange> uninitialized_default_construct(ForwardRange&& r); // since C++20
365
366}
367
368template <class ForwardIterator, class Size>
369 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
370
371namespace ranges {
372
373template <nothrow-forward-iterator ForwardIterator>
374  requires default_initializable<iter_value_t<ForwardIterator>>
375 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
376
377}
378
379template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
380
381template<class X>
382class auto_ptr                                  // deprecated in C++11, removed in C++17
383{
384public:
385    typedef X element_type;
386
387    explicit auto_ptr(X* p =0) throw();
388    auto_ptr(auto_ptr&) throw();
389    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
390    auto_ptr& operator=(auto_ptr&) throw();
391    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
392    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
393    ~auto_ptr() throw();
394
395    typename add_lvalue_reference<X>::type operator*() const throw();
396    X* operator->() const throw();
397    X* get() const throw();
398    X* release() throw();
399    void reset(X* p =0) throw();
400
401    auto_ptr(auto_ptr_ref<X>) throw();
402    template<class Y> operator auto_ptr_ref<Y>() throw();
403    template<class Y> operator auto_ptr<Y>() throw();
404};
405
406template <class T>
407struct default_delete
408{
409    constexpr default_delete() noexcept = default;
410    template <class U> constexpr default_delete(const default_delete<U>&) noexcept; // constexpr since C++23
411
412    constexpr void operator()(T*) const noexcept;                                   // constexpr since C++23
413};
414
415template <class T>
416struct default_delete<T[]>
417{
418    constexpr default_delete() noexcept = default;
419    template <class U> constexpr default_delete(const default_delete <U[]>&) noexcept; // constexpr since C++23
420    constexpr void operator()(T*) const noexcept;                                      // constexpr since C++23
421    template <class U> void operator()(U*) const = delete;
422};
423
424template <class T, class D = default_delete<T>>
425class unique_ptr
426{
427public:
428    typedef see below pointer;
429    typedef T element_type;
430    typedef D deleter_type;
431
432    // constructors
433    constexpr unique_ptr() noexcept;
434    constexpr explicit unique_ptr(pointer p) noexcept;           // constexpr since C++23
435    constexpr unique_ptr(pointer p, see below d1) noexcept;      // constexpr since C++23
436    constexpr unique_ptr(pointer p, see below d2) noexcept;      // constexpr since C++23
437    constexpr unique_ptr(unique_ptr&& u) noexcept;               // constexpr since C++23
438    constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
439    template <class U, class E>
440        constexpr unique_ptr(unique_ptr<U, E>&& u) noexcept;     // constexpr since C++23
441    template <class U>
442        unique_ptr(auto_ptr<U>&& u) noexcept;                    // removed in C++17
443
444    // destructor
445    constexpr ~unique_ptr();                                     // constexpr since C++23
446
447    // assignment
448    constexpr unique_ptr& operator=(unique_ptr&& u) noexcept;                         // constexpr since C++23
449    template <class U, class E>
450    constexpr unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;                   // constexpr since C++23
451    constexpr unique_ptr& operator=(nullptr_t) noexcept;                              // constexpr since C++23
452
453    // observers
454    typename constexpr add_lvalue_reference<T>::type operator*() const;               // constexpr since C++23
455    constexpr pointer operator->() const noexcept;                                    // constexpr since C++23
456    constexpr pointer get() const noexcept;                                           // constexpr since C++23
457    constexpr deleter_type& get_deleter() noexcept;                                   // constexpr since C++23
458    constexpr const deleter_type& get_deleter() const noexcept;                       // constexpr since C++23
459    constexpr explicit operator bool() const noexcept;                                // constexpr since C++23
460
461    // modifiers
462    constexpr pointer release() noexcept;                                             // constexpr since C++23
463    constexpr void reset(pointer p = pointer()) noexcept;                             // constexpr since C++23
464    constexpr void swap(unique_ptr& u) noexcept;                                      // constexpr since C++23
465};
466
467template <class T, class D>
468class unique_ptr<T[], D>
469{
470public:
471    typedef implementation-defined pointer;
472    typedef T element_type;
473    typedef D deleter_type;
474
475    // constructors
476    constexpr unique_ptr() noexcept;
477    constexpr explicit unique_ptr(pointer p) noexcept;          // constexpr since C++23
478    constexpr unique_ptr(pointer p, see below d) noexcept;      // constexpr since C++23
479    constexpr unique_ptr(pointer p, see below d) noexcept;      // constexpr since C++23
480    constexpr unique_ptr(unique_ptr&& u) noexcept;              // constexpr since C++23
481    template <class U, class E>
482    constexpr unique_ptr(unique_ptr <U, E>&& u) noexcept;       // constexpr since C++23
483    constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
484
485    // destructor
486    constexpr ~unique_ptr();                                    // constexpr since C++23
487
488    // assignment
489    constexpr unique_ptr& operator=(unique_ptr&& u) noexcept;        // constexpr since C++23
490    template <class U, class E>
491    constexpr unique_ptr& operator=(unique_ptr <U, E>&& u) noexcept; // constexpr since C++23
492    constexpr unique_ptr& operator=(nullptr_t) noexcept;             // constexpr since C++23
493
494    // observers
495    constexpr T& operator[](size_t i) const;                    // constexpr since C++23
496    constexpr pointer get() const noexcept;                     // constexpr since C++23
497    constexpr deleter_type& get_deleter() noexcept;             // constexpr since C++23
498    constexpr const deleter_type& get_deleter() const noexcept; // constexpr since C++23
499    constexpr explicit operator bool() const noexcept;          // constexpr since C++23
500
501    // modifiers
502    constexpr pointer release() noexcept;                       // constexpr since C++23
503    constexpr void reset(pointer p = pointer()) noexcept;       // constexpr since C++23
504    constexpr void reset(nullptr_t) noexcept;                   // constexpr since C++23
505  template <class U> void reset(U) = delete;
506    constexpr void swap(unique_ptr& u) noexcept;                // constexpr since C++23
507};
508
509template <class T, class D>
510    constexpr void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;                 // constexpr since C++23
511
512template <class T1, class D1, class T2, class D2>
513    constexpr bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);    // constexpr since C++23
514template <class T1, class D1, class T2, class D2>
515    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);              // removed in C++20
516template <class T1, class D1, class T2, class D2>
517    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
518template <class T1, class D1, class T2, class D2>
519    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
520template <class T1, class D1, class T2, class D2>
521    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
522template <class T1, class D1, class T2, class D2>
523    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
524template<class T1, class D1, class T2, class D2>
525  requires three_way_comparable_with<typename unique_ptr<T1, D1>::pointer,
526                                     typename unique_ptr<T2, D2>::pointer>
527  compare_three_way_result_t<typename unique_ptr<T1, D1>::pointer,
528                             typename unique_ptr<T2, D2>::pointer>
529    operator<=>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);      // C++20
530
531template <class T, class D>
532    constexpr bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;   // constexpr since C++23
533template <class T, class D>
534    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;             // removed in C++20
535template <class T, class D>
536    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;             // removed in C++20
537template <class T, class D>
538    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;             // removed in C++20
539
540template <class T, class D>
541    constexpr bool operator<(const unique_ptr<T, D>& x, nullptr_t);     // constexpr since C++23
542template <class T, class D>
543    constexpr bool operator<(nullptr_t, const unique_ptr<T, D>& y);     // constexpr since C++23
544template <class T, class D>
545    constexpr bool operator<=(const unique_ptr<T, D>& x, nullptr_t);    // constexpr since C++23
546template <class T, class D>
547    constexpr bool operator<=(nullptr_t, const unique_ptr<T, D>& y);    // constexpr since C++23
548template <class T, class D>
549    constexpr bool operator>(const unique_ptr<T, D>& x, nullptr_t);     // constexpr since C++23
550template <class T, class D>
551    constexpr bool operator>(nullptr_t, const unique_ptr<T, D>& y);     // constexpr since C++23
552template <class T, class D>
553    constexpr bool operator>=(const unique_ptr<T, D>& x, nullptr_t);    // constexpr since C++23
554template <class T, class D>
555    constexpr bool operator>=(nullptr_t, const unique_ptr<T, D>& y);    // constexpr since C++23
556template<class T, class D>
557  requires three_way_comparable<typename unique_ptr<T, D>::pointer>
558  compare_three_way_result_t<typename unique_ptr<T, D>::pointer>
559    constexpr operator<=>(const unique_ptr<T, D>& x, nullptr_t);        // C++20, constexpr since C++23
560
561class bad_weak_ptr
562    : public std::exception
563{
564    bad_weak_ptr() noexcept;
565};
566
567template<class T, class... Args>
568constexpr unique_ptr<T> make_unique(Args&&... args);                            // C++14, constexpr since C++23
569template<class T>
570constexpr unique_ptr<T> make_unique(size_t n);                                  // C++14, constexpr since C++23
571template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
572
573template<class T>
574  constexpr unique_ptr<T> make_unique_for_overwrite();                        // T is not array, C++20, constexpr since C++23
575template<class T>
576  constexpr unique_ptr<T> make_unique_for_overwrite(size_t n);                // T is U[], C++20, constexpr since C++23
577template<class T, class... Args>
578  unspecified make_unique_for_overwrite(Args&&...) = delete;                  // T is U[N], C++20
579
580template<class E, class T, class Y, class D>
581    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
582
583template<class T>
584class shared_ptr
585{
586public:
587    typedef T element_type; // until C++17
588    typedef remove_extent_t<T> element_type; // since C++17
589    typedef weak_ptr<T> weak_type; // C++17
590
591    // constructors:
592    constexpr shared_ptr() noexcept;
593    template<class Y> explicit shared_ptr(Y* p);
594    template<class Y, class D> shared_ptr(Y* p, D d);
595    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
596    template <class D> shared_ptr(nullptr_t p, D d);
597    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
598    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
599    shared_ptr(const shared_ptr& r) noexcept;
600    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
601    shared_ptr(shared_ptr&& r) noexcept;
602    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
603    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
604    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
605    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
606    shared_ptr(nullptr_t) : shared_ptr() { }
607
608    // destructor:
609    ~shared_ptr();
610
611    // assignment:
612    shared_ptr& operator=(const shared_ptr& r) noexcept;
613    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
614    shared_ptr& operator=(shared_ptr&& r) noexcept;
615    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
616    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
617    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
618
619    // modifiers:
620    void swap(shared_ptr& r) noexcept;
621    void reset() noexcept;
622    template<class Y> void reset(Y* p);
623    template<class Y, class D> void reset(Y* p, D d);
624    template<class Y, class D, class A> void reset(Y* p, D d, A a);
625
626    // observers:
627    T* get() const noexcept;
628    T& operator*() const noexcept;
629    T* operator->() const noexcept;
630    long use_count() const noexcept;
631    bool unique() const noexcept;  // deprected in C++17, removed in C++20
632    explicit operator bool() const noexcept;
633    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
634    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
635};
636
637template<class T>
638shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
639template<class T, class D>
640shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
641
642// shared_ptr comparisons:
643template<class T, class U>
644    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
645template<class T, class U>
646    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;               // removed in C++20
647template<class T, class U>
648    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;                // removed in C++20
649template<class T, class U>
650    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;                // removed in C++20
651template<class T, class U>
652    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;               // removed in C++20
653template<class T, class U>
654    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;               // removed in C++20
655template<class T, class U>
656    strong_ordering operator<=>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;   // C++20
657
658template <class T>
659    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
660template <class T>
661    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
662template <class T>
663    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;               // removed in C++20
664template <class T>
665    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
666template <class T>
667    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;                // removed in C++20
668template <class T>
669    bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;                // removed in C++20
670template <class T>
671    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;               // removed in C++20
672template <class T>
673    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
674template <class T>
675    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;                // removed in C++20
676template <class T>
677    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;                // removed in C++20
678template <class T>
679    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;               // removed in C++20
680template <class T>
681    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
682template<class T>
683    strong_ordering operator<=>(shared_ptr<T> const& x, nullptr_t) noexcept;   // C++20
684
685// shared_ptr specialized algorithms:
686template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
687
688// shared_ptr casts:
689template<class T, class U>
690    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
691template<class T, class U>
692    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
693template<class T, class U>
694    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
695
696// shared_ptr I/O:
697template<class E, class T, class Y>
698    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
699
700// shared_ptr get_deleter:
701template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
702
703template<class T, class... Args>
704    shared_ptr<T> make_shared(Args&&... args); // T is not an array
705template<class T, class A, class... Args>
706    shared_ptr<T> allocate_shared(const A& a, Args&&... args); // T is not an array
707
708template<class T>
709    shared_ptr<T> make_shared(size_t N); // T is U[] (since C++20)
710template<class T, class A>
711    shared_ptr<T> allocate_shared(const A& a, size_t N); // T is U[] (since C++20)
712
713template<class T>
714    shared_ptr<T> make_shared(); // T is U[N] (since C++20)
715template<class T, class A>
716    shared_ptr<T> allocate_shared(const A& a); // T is U[N] (since C++20)
717
718template<class T>
719    shared_ptr<T> make_shared(size_t N, const remove_extent_t<T>& u); // T is U[] (since C++20)
720template<class T, class A>
721    shared_ptr<T> allocate_shared(const A& a, size_t N, const remove_extent_t<T>& u); // T is U[] (since C++20)
722
723template<class T> shared_ptr<T>
724    make_shared(const remove_extent_t<T>& u); // T is U[N] (since C++20)
725template<class T, class A>
726    shared_ptr<T> allocate_shared(const A& a, const remove_extent_t<T>& u); // T is U[N] (since C++20)
727
728template<class T>
729  shared_ptr<T> make_shared_for_overwrite();                                  // T is not U[], C++20
730template<class T, class A>
731  shared_ptr<T> allocate_shared_for_overwrite(const A& a);                    // T is not U[], C++20
732
733template<class T>
734  shared_ptr<T> make_shared_for_overwrite(size_t N);                          // T is U[], C++20
735template<class T, class A>
736  shared_ptr<T> allocate_shared_for_overwrite(const A& a, size_t N);          // T is U[], C++20
737
738template<class T>
739class weak_ptr
740{
741public:
742    typedef T element_type; // until C++17
743    typedef remove_extent_t<T> element_type; // since C++17
744
745    // constructors
746    constexpr weak_ptr() noexcept;
747    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
748    weak_ptr(weak_ptr const& r) noexcept;
749    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
750    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
751    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
752
753    // destructor
754    ~weak_ptr();
755
756    // assignment
757    weak_ptr& operator=(weak_ptr const& r) noexcept;
758    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
759    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
760    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
761    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
762
763    // modifiers
764    void swap(weak_ptr& r) noexcept;
765    void reset() noexcept;
766
767    // observers
768    long use_count() const noexcept;
769    bool expired() const noexcept;
770    shared_ptr<T> lock() const noexcept;
771    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
772    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
773};
774
775template<class T>
776weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
777
778// weak_ptr specialized algorithms:
779template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
780
781// class owner_less:
782template<class T> struct owner_less;
783
784template<class T>
785struct owner_less<shared_ptr<T> >
786    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
787{
788    typedef bool result_type;
789    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
790    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
791    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
792};
793
794template<class T>
795struct owner_less<weak_ptr<T> >
796    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
797{
798    typedef bool result_type;
799    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
800    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
801    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
802};
803
804template <>  // Added in C++14
805struct owner_less<void>
806{
807    template <class _Tp, class _Up>
808    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
809    template <class _Tp, class _Up>
810    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
811    template <class _Tp, class _Up>
812    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
813    template <class _Tp, class _Up>
814    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
815
816    typedef void is_transparent;
817};
818
819template<class T>
820class enable_shared_from_this
821{
822protected:
823    constexpr enable_shared_from_this() noexcept;
824    enable_shared_from_this(enable_shared_from_this const&) noexcept;
825    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
826    ~enable_shared_from_this();
827public:
828    shared_ptr<T> shared_from_this();
829    shared_ptr<T const> shared_from_this() const;
830};
831
832template<class T>
833    bool atomic_is_lock_free(const shared_ptr<T>* p);
834template<class T>
835    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
836template<class T>
837    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
838template<class T>
839    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
840template<class T>
841    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
842template<class T>
843    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
844template<class T>
845    shared_ptr<T>
846    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
847template<class T>
848    bool
849    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
850template<class T>
851    bool
852    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
853template<class T>
854    bool
855    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
856                                          shared_ptr<T> w, memory_order success,
857                                          memory_order failure);
858template<class T>
859    bool
860    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
861                                            shared_ptr<T> w, memory_order success,
862                                            memory_order failure);
863// Hash support
864template <class T> struct hash;
865template <class T, class D> struct hash<unique_ptr<T, D> >;
866template <class T> struct hash<shared_ptr<T> >;
867
868template <class T, class Alloc>
869  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
870
871// [allocator.uses.construction], uses-allocator construction
872template<class T, class Alloc, class... Args>
873  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
874                                                  Args&&... args) noexcept;
875template<class T, class Alloc, class Tuple1, class Tuple2>
876  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
877                                                  piecewise_construct_t,
878                                                  Tuple1&& x, Tuple2&& y) noexcept;
879template<class T, class Alloc>
880  constexpr auto uses_allocator_construction_args(const Alloc& alloc) noexcept;   // since C++20
881template<class T, class Alloc, class U, class V>
882  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
883                                                  U&& u, V&& v) noexcept;
884template<class T, class Alloc, class U, class V>
885  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++23
886                                                  pair<U, V>& pr) noexcept;
887template<class T, class Alloc, class U, class V>
888  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
889                                                  const pair<U, V>& pr) noexcept;
890template<class T, class Alloc, class U, class V>
891  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
892                                                  pair<U, V>&& pr) noexcept;
893template<class T, class Alloc, class U, class V>
894  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++23
895                                                  const pair<U, V>&& pr) noexcept;
896template<class T, class Alloc, pair-like P>
897  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
898                                                  P&& p) noexcept;
899template<class T, class Alloc, class U>
900  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
901                                                  U&& u) noexcept;
902template<class T, class Alloc, class... Args>
903  constexpr T make_obj_using_allocator(const Alloc& alloc, Args&&... args);       // since C++20
904template<class T, class Alloc, class... Args>
905  constexpr T* uninitialized_construct_using_allocator(T* p,                      // since C++20
906                                                         const Alloc& alloc, Args&&... args);
907
908// [ptr.align]
909void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
910
911template<size_t N, class T>
912[[nodiscard]] constexpr T* assume_aligned(T* ptr); // since C++20
913
914}  // std
915
916*/
917
918// clang-format on
919
920#include <__config>
921#include <__memory/addressof.h>
922#include <__memory/align.h>
923#include <__memory/allocate_at_least.h>
924#include <__memory/allocation_guard.h>
925#include <__memory/allocator.h>
926#include <__memory/allocator_arg_t.h>
927#include <__memory/allocator_traits.h>
928#include <__memory/assume_aligned.h>
929#include <__memory/auto_ptr.h>
930#include <__memory/compressed_pair.h>
931#include <__memory/concepts.h>
932#include <__memory/construct_at.h>
933#include <__memory/pointer_traits.h>
934#include <__memory/ranges_construct_at.h>
935#include <__memory/ranges_uninitialized_algorithms.h>
936#include <__memory/raw_storage_iterator.h>
937#include <__memory/shared_ptr.h>
938#include <__memory/temporary_buffer.h>
939#include <__memory/uninitialized_algorithms.h>
940#include <__memory/unique_ptr.h>
941#include <__memory/uses_allocator.h>
942#include <__memory/uses_allocator_construction.h>
943#include <version>
944
945// standard-mandated includes
946
947// [memory.syn]
948#include <compare>
949
950#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
951#  pragma GCC system_header
952#endif
953
954#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
955#  include <atomic>
956#  include <concepts>
957#  include <cstddef>
958#  include <cstdint>
959#  include <cstdlib>
960#  include <cstring>
961#  include <iosfwd>
962#  include <iterator>
963#  include <new>
964#  include <stdexcept>
965#  include <tuple>
966#  include <type_traits>
967#  include <typeinfo>
968#  include <utility>
969#endif
970
971#endif // _LIBCPP_MEMORY
972