xref: /freebsd/contrib/llvm-project/libcxx/include/memory (revision 1db9f3b21e39176dd5b67cf8ac378633b172463e)
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    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept; // constexpr in C++20
92
93    template <class T, class... Args>
94    static void construct(allocator_type& a, T* p, Args&&... args); // constexpr in C++20
95
96    template <class T>
97    static void destroy(allocator_type& a, T* p); // constexpr in C++20
98
99    static size_type max_size(const allocator_type& a); // noexcept in C++14, constexpr in C++20
100    static allocator_type select_on_container_copy_construction(const allocator_type& a); // constexpr in C++20
101};
102
103template<class Pointer>
104struct allocation_result {
105    Pointer ptr;
106    size_t count;
107}; // since C++23
108
109template<class Allocator>
110[[nodiscard]] constexpr allocation_result<typename allocator_traits<Allocator>::pointer>
111    allocate_at_least(Allocator& a, size_t n); // since C++23
112
113template <>
114class allocator<void> // removed in C++20
115{
116public:
117    typedef void*                                 pointer;
118    typedef const void*                           const_pointer;
119    typedef void                                  value_type;
120
121    template <class _Up> struct rebind {typedef allocator<_Up> other;};
122};
123
124template <class T>
125class allocator
126{
127public:
128    typedef size_t    size_type;
129    typedef ptrdiff_t difference_type;
130    typedef T*        pointer;                           // deprecated in C++17, removed in C++20
131    typedef const T*  const_pointer;                     // deprecated in C++17, removed in C++20
132    typedef typename add_lvalue_reference<T>::type
133                      reference;                         // deprecated in C++17, removed in C++20
134    typedef typename add_lvalue_reference<const T>::type
135                      const_reference;                   // deprecated in C++17, removed in C++20
136
137    typedef T         value_type;
138
139    template <class U> struct rebind {typedef allocator<U> other;}; // deprecated in C++17, removed in C++20
140
141    typedef true_type propagate_on_container_move_assignment;
142    typedef true_type is_always_equal;
143
144    constexpr allocator() noexcept;                      // constexpr in C++20
145    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
146    template <class U>
147      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
148    ~allocator();                                        // constexpr in C++20
149    pointer address(reference x) const noexcept;             // deprecated in C++17, removed in C++20
150    const_pointer address(const_reference x) const noexcept; // deprecated in C++17, removed in C++20
151    T* allocate(size_t n, const void* hint);          // deprecated in C++17, removed in C++20
152    T* allocate(size_t n);                              // constexpr in C++20
153    void deallocate(T* p, size_t n) noexcept;           // constexpr in C++20
154    size_type max_size() const noexcept;              // deprecated in C++17, removed in C++20
155    template<class U, class... Args>
156        void construct(U* p, Args&&... args);         // deprecated in C++17, removed in C++20
157    template <class U>
158        void destroy(U* p);                           // deprecated in C++17, removed in C++20
159};
160
161template <class T, class U>
162bool operator==(const allocator<T>&, const allocator<U>&) noexcept; // constexpr in C++20
163
164template <class T, class U>
165bool operator!=(const allocator<T>&, const allocator<U>&) noexcept; // removed in C++20
166
167template <class OutputIterator, class T>
168class raw_storage_iterator // deprecated in C++17, removed in C++20
169    : public iterator<output_iterator_tag, void, void, void, void> // until C++17
170{
171public:
172    typedef output_iterator_tag iterator_category;
173    typedef void                value_type;
174    typedef void                difference_type; // until C++20
175    typedef ptrdiff_t           difference_type; // since C++20
176    typedef void                pointer;
177    typedef void                reference;
178
179    explicit raw_storage_iterator(OutputIterator x);
180    raw_storage_iterator& operator*();
181    raw_storage_iterator& operator=(const T& element);
182    raw_storage_iterator& operator++();
183    raw_storage_iterator  operator++(int);
184};
185
186template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
187template <class T> void               return_temporary_buffer(T* p) noexcept;
188
189template <class T> T* addressof(T& r) noexcept;
190template <class T> T* addressof(const T&& r) noexcept = delete;
191
192template <class InputIterator, class ForwardIterator>
193ForwardIterator
194uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
195
196namespace ranges {
197
198template<class InputIterator, class OutputIterator>
199using uninitialized_copy_result = in_out_result<InputIterator, OutputIterator>; // since C++20
200
201template<input_iterator InputIterator, sentinel-for<InputIterator> Sentinel1, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel2>
202  requires constructible_from<iter_value_t<OutputIterator>, iter_reference_t<InputIterator>>
203uninitialized_copy_result<InputIterator, OutputIterator>
204uninitialized_copy(InputIterator ifirst, Sentinel1 ilast, OutputIterator ofirst, Sentinel2 olast); // since C++20
205
206template<input_range InputRange, nothrow-forward-range OutputRange>
207  requires constructible_from<range_value_t<OutputRange>, range_reference_t<InputRange>>
208uninitialized_copy_result<borrowed_iterator_t<InputRange>, borrowed_iterator_t<OutputRange>>
209uninitialized_copy(InputRange&& in_range, OutputRange&& out_range); // since C++20
210
211}
212
213template <class InputIterator, class Size, class ForwardIterator>
214ForwardIterator
215uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
216
217namespace ranges {
218
219template<class InputIterator, class OutputIterator>
220using uninitialized_copy_n_result = in_out_result<InputIterator, OutputIterator>; // since C++20
221
222template<input_iterator InputIterator, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel>
223  requires constructible_from<iter_value_t<OutputIterator>, iter_reference_t<InputIterator>>
224uninitialized_copy_n_result<InputIterator, OutputIterator>
225uninitialized_copy_n(InputIterator ifirst, iter_difference_t<InputIterator> n, OutputIterator ofirst, Sentinel olast); // since C++20
226
227}
228
229template <class ForwardIterator, class T>
230void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
231
232namespace ranges {
233
234template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel, class T>
235  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
236ForwardIterator uninitialized_fill(ForwardIterator first, Sentinel last, const T& x); // since C++20
237
238template <nothrow-forward-range ForwardRange, class T>
239  requires constructible_from<range_value_t<ForwardRange>, const T&>
240borrowed_iterator_t<ForwardRange> uninitialized_fill(ForwardRange&& range, const T& x); // since C++20
241
242}
243
244template <class ForwardIterator, class Size, class T>
245ForwardIterator
246uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
247
248namespace ranges {
249
250template <nothrow-forward-iterator ForwardIterator, class T>
251  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
252ForwardIterator uninitialized_fill_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
253
254}
255
256template <class T, class ...Args>
257constexpr T* construct_at(T* location, Args&& ...args); // since C++20
258
259namespace ranges {
260  template<class T, class... Args>
261    constexpr T* construct_at(T* location, Args&&... args); // since C++20
262}
263
264template <class T>
265void destroy_at(T* location); // constexpr in C++20
266
267namespace ranges {
268  template<destructible T>
269    constexpr void destroy_at(T* location) noexcept; // since C++20
270}
271
272template <class ForwardIterator>
273void destroy(ForwardIterator first, ForwardIterator last); // constexpr in C++20
274
275namespace ranges {
276  template<nothrow-input-iterator InputIterator, nothrow-sentinel-for<InputIterator> Sentinel>
277    requires destructible<iter_value_t<InputIterator>>
278    constexpr InputIterator destroy(InputIterator first, Sentinel last) noexcept; // since C++20
279  template<nothrow-input-range InputRange>
280    requires destructible<range_value_t<InputRange>>
281    constexpr borrowed_iterator_t<InputRange> destroy(InputRange&& range) noexcept; // since C++20
282}
283
284template <class ForwardIterator, class Size>
285ForwardIterator destroy_n(ForwardIterator first, Size n); // constexpr in C++20
286
287namespace ranges {
288  template<nothrow-input-iterator InputIterator>
289    requires destructible<iter_value_t<InputIterator>>
290    constexpr InputIterator destroy_n(InputIterator first, iter_difference_t<InputIterator> n) noexcept; // since C++20
291}
292
293template <class InputIterator, class ForwardIterator>
294 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
295
296namespace ranges {
297
298template<class InputIterator, class OutputIterator>
299using uninitialized_move_result = in_out_result<InputIterator, OutputIterator>; // since C++20
300
301template <input_iterator InputIterator, sentinel_for<InputIterator> Sentinel1, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<O> Sentinel2>
302  requires constructible_from<iter_value_t<OutputIterator>, iter_rvalue_reference_t<InputIterator>>
303uninitialized_move_result<InputIterator, OutputIterator>
304uninitialized_move(InputIterator ifirst, Sentinel1 ilast, OutputIterator ofirst, Sentinel2 olast); // since C++20
305
306template<input_range InputRange, nothrow-forward-range OutputRange>
307  requires constructible_from<range_value_t<OutputRange>, range_rvalue_reference_t<InputRange>>
308uninitialized_move_result<borrowed_iterator_t<InputRange>, borrowed_iterator_t<OutputRange>>
309uninitialized_move(InputRange&& in_range, OutputRange&& out_range); // since C++20
310
311}
312
313template <class InputIterator, class Size, class ForwardIterator>
314 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
315
316namespace ranges {
317
318template<class InputIterator, class OutputIterator>
319using uninitialized_move_n_result = in_out_result<InputIterator, OutputIterator>; // since C++20
320
321template<input_iterator InputIterator, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel>
322  requires constructible_from<iter_value_t<OutputIterator>, iter_rvalue_reference_t<InputIterator>>
323uninitialized_move_n_result<InputIterator, OutputIterator>
324uninitialized_move_n(InputIterator ifirst, iter_difference_t<InputIterator> n, OutputIterator ofirst, Sentinel olast); // since C++20
325
326}
327
328template <class ForwardIterator>
329 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
330
331namespace ranges {
332
333template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
334  requires default_initializable<iter_value_t<ForwardIterator>>
335 ForwardIterator uninitialized_value_construct(ForwardIterator first, Sentinel last); // since C++20
336
337template <nothrow-forward-range ForwardRange>
338  requires default_initializable<range_value_t<ForwardRange>>
339 borrowed_iterator_t<ForwardRange> uninitialized_value_construct(ForwardRange&& r); // since C++20
340
341}
342
343template <class ForwardIterator, class Size>
344 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
345
346namespace ranges {
347
348template <nothrow-forward-iterator ForwardIterator>
349  requires default_initializable<iter_value_t<ForwardIterator>>
350 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
351
352}
353
354template <class ForwardIterator>
355 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
356
357namespace ranges {
358
359template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
360  requires default_initializable<iter_value_t<ForwardIterator>>
361 ForwardIterator uninitialized_default_construct(ForwardIterator first, Sentinel last); // since C++20
362
363template <nothrow-forward-range ForwardRange>
364  requires default_initializable<range_value_t<ForwardRange>>
365 borrowed_iterator_t<ForwardRange> uninitialized_default_construct(ForwardRange&& r); // since C++20
366
367}
368
369template <class ForwardIterator, class Size>
370 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
371
372namespace ranges {
373
374template <nothrow-forward-iterator ForwardIterator>
375  requires default_initializable<iter_value_t<ForwardIterator>>
376 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
377
378}
379
380template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
381
382template<class X>
383class auto_ptr                                  // deprecated in C++11, removed in C++17
384{
385public:
386    typedef X element_type;
387
388    explicit auto_ptr(X* p =0) throw();
389    auto_ptr(auto_ptr&) throw();
390    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
391    auto_ptr& operator=(auto_ptr&) throw();
392    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
393    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
394    ~auto_ptr() throw();
395
396    typename add_lvalue_reference<X>::type operator*() const throw();
397    X* operator->() const throw();
398    X* get() const throw();
399    X* release() throw();
400    void reset(X* p =0) throw();
401
402    auto_ptr(auto_ptr_ref<X>) throw();
403    template<class Y> operator auto_ptr_ref<Y>() throw();
404    template<class Y> operator auto_ptr<Y>() throw();
405};
406
407template <class T>
408struct default_delete
409{
410    constexpr default_delete() noexcept = default;
411    template <class U> constexpr default_delete(const default_delete<U>&) noexcept; // constexpr since C++23
412
413    constexpr void operator()(T*) const noexcept;                                   // constexpr since C++23
414};
415
416template <class T>
417struct default_delete<T[]>
418{
419    constexpr default_delete() noexcept = default;
420    template <class U> constexpr default_delete(const default_delete <U[]>&) noexcept; // constexpr since C++23
421    constexpr void operator()(T*) const noexcept;                                      // constexpr since C++23
422    template <class U> void operator()(U*) const = delete;
423};
424
425template <class T, class D = default_delete<T>>
426class unique_ptr
427{
428public:
429    typedef see below pointer;
430    typedef T element_type;
431    typedef D deleter_type;
432
433    // constructors
434    constexpr unique_ptr() noexcept;
435    constexpr explicit unique_ptr(pointer p) noexcept;           // constexpr since C++23
436    constexpr unique_ptr(pointer p, see below d1) noexcept;      // constexpr since C++23
437    constexpr unique_ptr(pointer p, see below d2) noexcept;      // constexpr since C++23
438    constexpr unique_ptr(unique_ptr&& u) noexcept;               // constexpr since C++23
439    constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
440    template <class U, class E>
441        constexpr unique_ptr(unique_ptr<U, E>&& u) noexcept;     // constexpr since C++23
442    template <class U>
443        unique_ptr(auto_ptr<U>&& u) noexcept;                    // removed in C++17
444
445    // destructor
446    constexpr ~unique_ptr();                                     // constexpr since C++23
447
448    // assignment
449    constexpr unique_ptr& operator=(unique_ptr&& u) noexcept;                         // constexpr since C++23
450    template <class U, class E>
451    constexpr unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;                   // constexpr since C++23
452    constexpr unique_ptr& operator=(nullptr_t) noexcept;                              // constexpr since C++23
453
454    // observers
455    typename constexpr add_lvalue_reference<T>::type operator*() const;               // constexpr since C++23
456    constexpr pointer operator->() const noexcept;                                    // constexpr since C++23
457    constexpr pointer get() const noexcept;                                           // constexpr since C++23
458    constexpr deleter_type& get_deleter() noexcept;                                   // constexpr since C++23
459    constexpr const deleter_type& get_deleter() const noexcept;                       // constexpr since C++23
460    constexpr explicit operator bool() const noexcept;                                // constexpr since C++23
461
462    // modifiers
463    constexpr pointer release() noexcept;                                             // constexpr since C++23
464    constexpr void reset(pointer p = pointer()) noexcept;                             // constexpr since C++23
465    constexpr void swap(unique_ptr& u) noexcept;                                      // constexpr since C++23
466};
467
468template <class T, class D>
469class unique_ptr<T[], D>
470{
471public:
472    typedef implementation-defined pointer;
473    typedef T element_type;
474    typedef D deleter_type;
475
476    // constructors
477    constexpr unique_ptr() noexcept;
478    constexpr explicit unique_ptr(pointer p) noexcept;          // constexpr since C++23
479    constexpr unique_ptr(pointer p, see below d) noexcept;      // constexpr since C++23
480    constexpr unique_ptr(pointer p, see below d) noexcept;      // constexpr since C++23
481    constexpr unique_ptr(unique_ptr&& u) noexcept;              // constexpr since C++23
482    template <class U, class E>
483    constexpr unique_ptr(unique_ptr <U, E>&& u) noexcept;       // constexpr since C++23
484    constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
485
486    // destructor
487    constexpr ~unique_ptr();                                    // constexpr since C++23
488
489    // assignment
490    constexpr unique_ptr& operator=(unique_ptr&& u) noexcept;        // constexpr since C++23
491    template <class U, class E>
492    constexpr unique_ptr& operator=(unique_ptr <U, E>&& u) noexcept; // constexpr since C++23
493    constexpr unique_ptr& operator=(nullptr_t) noexcept;             // constexpr since C++23
494
495    // observers
496    constexpr T& operator[](size_t i) const;                    // constexpr since C++23
497    constexpr pointer get() const noexcept;                     // constexpr since C++23
498    constexpr deleter_type& get_deleter() noexcept;             // constexpr since C++23
499    constexpr const deleter_type& get_deleter() const noexcept; // constexpr since C++23
500    constexpr explicit operator bool() const noexcept;          // constexpr since C++23
501
502    // modifiers
503    constexpr pointer release() noexcept;                       // constexpr since C++23
504    constexpr void reset(pointer p = pointer()) noexcept;       // constexpr since C++23
505    constexpr void reset(nullptr_t) noexcept;                   // constexpr since C++23
506  template <class U> void reset(U) = delete;
507    constexpr void swap(unique_ptr& u) noexcept;                // constexpr since C++23
508};
509
510template <class T, class D>
511    constexpr void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;                 // constexpr since C++23
512
513template <class T1, class D1, class T2, class D2>
514    constexpr bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);    // constexpr since C++23
515template <class T1, class D1, class T2, class D2>
516    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);              // removed in C++20
517template <class T1, class D1, class T2, class D2>
518    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
519template <class T1, class D1, class T2, class D2>
520    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
521template <class T1, class D1, class T2, class D2>
522    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
523template <class T1, class D1, class T2, class D2>
524    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
525template<class T1, class D1, class T2, class D2>
526  requires three_way_comparable_with<typename unique_ptr<T1, D1>::pointer,
527                                     typename unique_ptr<T2, D2>::pointer>
528  compare_three_way_result_t<typename unique_ptr<T1, D1>::pointer,
529                             typename unique_ptr<T2, D2>::pointer>
530    operator<=>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);      // C++20
531
532template <class T, class D>
533    constexpr bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;   // constexpr since C++23
534template <class T, class D>
535    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;             // removed in C++20
536template <class T, class D>
537    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;             // removed in C++20
538template <class T, class D>
539    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;             // removed in C++20
540
541template <class T, class D>
542    constexpr bool operator<(const unique_ptr<T, D>& x, nullptr_t);     // constexpr since C++23
543template <class T, class D>
544    constexpr bool operator<(nullptr_t, const unique_ptr<T, D>& y);     // constexpr since C++23
545template <class T, class D>
546    constexpr bool operator<=(const unique_ptr<T, D>& x, nullptr_t);    // constexpr since C++23
547template <class T, class D>
548    constexpr bool operator<=(nullptr_t, const unique_ptr<T, D>& y);    // constexpr since C++23
549template <class T, class D>
550    constexpr bool operator>(const unique_ptr<T, D>& x, nullptr_t);     // constexpr since C++23
551template <class T, class D>
552    constexpr bool operator>(nullptr_t, const unique_ptr<T, D>& y);     // constexpr since C++23
553template <class T, class D>
554    constexpr bool operator>=(const unique_ptr<T, D>& x, nullptr_t);    // constexpr since C++23
555template <class T, class D>
556    constexpr bool operator>=(nullptr_t, const unique_ptr<T, D>& y);    // constexpr since C++23
557template<class T, class D>
558  requires three_way_comparable<typename unique_ptr<T, D>::pointer>
559  compare_three_way_result_t<typename unique_ptr<T, D>::pointer>
560    constexpr operator<=>(const unique_ptr<T, D>& x, nullptr_t);        // C++20, constexpr since C++23
561
562class bad_weak_ptr
563    : public std::exception
564{
565    bad_weak_ptr() noexcept;
566};
567
568template<class T, class... Args>
569constexpr unique_ptr<T> make_unique(Args&&... args);                            // C++14, constexpr since C++23
570template<class T>
571constexpr unique_ptr<T> make_unique(size_t n);                                  // C++14, constexpr since C++23
572template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
573
574template<class T>
575  constexpr unique_ptr<T> make_unique_for_overwrite();                        // T is not array, C++20, constexpr since C++23
576template<class T>
577  constexpr unique_ptr<T> make_unique_for_overwrite(size_t n);                // T is U[], C++20, constexpr since C++23
578template<class T, class... Args>
579  unspecified make_unique_for_overwrite(Args&&...) = delete;                  // T is U[N], C++20
580
581template<class E, class T, class Y, class D>
582    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
583
584template<class T>
585class shared_ptr
586{
587public:
588    typedef T element_type; // until C++17
589    typedef remove_extent_t<T> element_type; // since C++17
590    typedef weak_ptr<T> weak_type; // C++17
591
592    // constructors:
593    constexpr shared_ptr() noexcept;
594    template<class Y> explicit shared_ptr(Y* p);
595    template<class Y, class D> shared_ptr(Y* p, D d);
596    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
597    template <class D> shared_ptr(nullptr_t p, D d);
598    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
599    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
600    shared_ptr(const shared_ptr& r) noexcept;
601    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
602    shared_ptr(shared_ptr&& r) noexcept;
603    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
604    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
605    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
606    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
607    shared_ptr(nullptr_t) : shared_ptr() { }
608
609    // destructor:
610    ~shared_ptr();
611
612    // assignment:
613    shared_ptr& operator=(const shared_ptr& r) noexcept;
614    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
615    shared_ptr& operator=(shared_ptr&& r) noexcept;
616    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
617    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
618    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
619
620    // modifiers:
621    void swap(shared_ptr& r) noexcept;
622    void reset() noexcept;
623    template<class Y> void reset(Y* p);
624    template<class Y, class D> void reset(Y* p, D d);
625    template<class Y, class D, class A> void reset(Y* p, D d, A a);
626
627    // observers:
628    T* get() const noexcept;
629    T& operator*() const noexcept;
630    T* operator->() const noexcept;
631    long use_count() const noexcept;
632    bool unique() const noexcept;  // deprected in C++17, removed in C++20
633    explicit operator bool() const noexcept;
634    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
635    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
636};
637
638template<class T>
639shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
640template<class T, class D>
641shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
642
643// shared_ptr comparisons:
644template<class T, class U>
645    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
646template<class T, class U>
647    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;               // removed in C++20
648template<class T, class U>
649    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;                // removed in C++20
650template<class T, class U>
651    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;                // removed in C++20
652template<class T, class U>
653    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;               // removed in C++20
654template<class T, class U>
655    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;               // removed in C++20
656template<class T, class U>
657    strong_ordering operator<=>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;   // C++20
658
659template <class T>
660    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
661template <class T>
662    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
663template <class T>
664    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;               // removed in C++20
665template <class T>
666    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
667template <class T>
668    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;                // removed in C++20
669template <class T>
670    bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;                // removed in C++20
671template <class T>
672    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;               // removed in C++20
673template <class T>
674    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
675template <class T>
676    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;                // removed in C++20
677template <class T>
678    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;                // removed in C++20
679template <class T>
680    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;               // removed in C++20
681template <class T>
682    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
683template<class T>
684    strong_ordering operator<=>(shared_ptr<T> const& x, nullptr_t) noexcept;   // C++20
685
686// shared_ptr specialized algorithms:
687template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
688
689// shared_ptr casts:
690template<class T, class U>
691    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
692template<class T, class U>
693    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
694template<class T, class U>
695    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
696
697// shared_ptr I/O:
698template<class E, class T, class Y>
699    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
700
701// shared_ptr get_deleter:
702template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
703
704template<class T, class... Args>
705    shared_ptr<T> make_shared(Args&&... args); // T is not an array
706template<class T, class A, class... Args>
707    shared_ptr<T> allocate_shared(const A& a, Args&&... args); // T is not an array
708
709template<class T>
710    shared_ptr<T> make_shared(size_t N); // T is U[] (since C++20)
711template<class T, class A>
712    shared_ptr<T> allocate_shared(const A& a, size_t N); // T is U[] (since C++20)
713
714template<class T>
715    shared_ptr<T> make_shared(); // T is U[N] (since C++20)
716template<class T, class A>
717    shared_ptr<T> allocate_shared(const A& a); // T is U[N] (since C++20)
718
719template<class T>
720    shared_ptr<T> make_shared(size_t N, const remove_extent_t<T>& u); // T is U[] (since C++20)
721template<class T, class A>
722    shared_ptr<T> allocate_shared(const A& a, size_t N, const remove_extent_t<T>& u); // T is U[] (since C++20)
723
724template<class T> shared_ptr<T>
725    make_shared(const remove_extent_t<T>& u); // T is U[N] (since C++20)
726template<class T, class A>
727    shared_ptr<T> allocate_shared(const A& a, const remove_extent_t<T>& u); // T is U[N] (since C++20)
728
729template<class T>
730  shared_ptr<T> make_shared_for_overwrite();                                  // T is not U[], C++20
731template<class T, class A>
732  shared_ptr<T> allocate_shared_for_overwrite(const A& a);                    // T is not U[], C++20
733
734template<class T>
735  shared_ptr<T> make_shared_for_overwrite(size_t N);                          // T is U[], C++20
736template<class T, class A>
737  shared_ptr<T> allocate_shared_for_overwrite(const A& a, size_t N);          // T is U[], C++20
738
739template<class T>
740class weak_ptr
741{
742public:
743    typedef T element_type; // until C++17
744    typedef remove_extent_t<T> element_type; // since C++17
745
746    // constructors
747    constexpr weak_ptr() noexcept;
748    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
749    weak_ptr(weak_ptr const& r) noexcept;
750    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
751    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
752    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
753
754    // destructor
755    ~weak_ptr();
756
757    // assignment
758    weak_ptr& operator=(weak_ptr const& r) noexcept;
759    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
760    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
761    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
762    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
763
764    // modifiers
765    void swap(weak_ptr& r) noexcept;
766    void reset() noexcept;
767
768    // observers
769    long use_count() const noexcept;
770    bool expired() const noexcept;
771    shared_ptr<T> lock() const noexcept;
772    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
773    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
774};
775
776template<class T>
777weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
778
779// weak_ptr specialized algorithms:
780template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
781
782// class owner_less:
783template<class T> struct owner_less;
784
785template<class T>
786struct owner_less<shared_ptr<T> >
787    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
788{
789    typedef bool result_type;
790    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
791    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
792    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
793};
794
795template<class T>
796struct owner_less<weak_ptr<T> >
797    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
798{
799    typedef bool result_type;
800    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
801    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
802    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
803};
804
805template <>  // Added in C++14
806struct owner_less<void>
807{
808    template <class _Tp, class _Up>
809    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
810    template <class _Tp, class _Up>
811    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
812    template <class _Tp, class _Up>
813    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
814    template <class _Tp, class _Up>
815    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
816
817    typedef void is_transparent;
818};
819
820template<class T>
821class enable_shared_from_this
822{
823protected:
824    constexpr enable_shared_from_this() noexcept;
825    enable_shared_from_this(enable_shared_from_this const&) noexcept;
826    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
827    ~enable_shared_from_this();
828public:
829    shared_ptr<T> shared_from_this();
830    shared_ptr<T const> shared_from_this() const;
831};
832
833template<class T>
834    bool atomic_is_lock_free(const shared_ptr<T>* p);
835template<class T>
836    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
837template<class T>
838    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
839template<class T>
840    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
841template<class T>
842    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
843template<class T>
844    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
845template<class T>
846    shared_ptr<T>
847    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
848template<class T>
849    bool
850    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
851template<class T>
852    bool
853    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
854template<class T>
855    bool
856    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
857                                          shared_ptr<T> w, memory_order success,
858                                          memory_order failure);
859template<class T>
860    bool
861    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
862                                            shared_ptr<T> w, memory_order success,
863                                            memory_order failure);
864// Hash support
865template <class T> struct hash;
866template <class T, class D> struct hash<unique_ptr<T, D> >;
867template <class T> struct hash<shared_ptr<T> >;
868
869template <class T, class Alloc>
870  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
871
872// [allocator.uses.construction], uses-allocator construction
873template<class T, class Alloc, class... Args>
874  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
875                                                  Args&&... args) noexcept;
876template<class T, class Alloc, class Tuple1, class Tuple2>
877  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
878                                                  piecewise_construct_t,
879                                                  Tuple1&& x, Tuple2&& y) noexcept;
880template<class T, class Alloc>
881  constexpr auto uses_allocator_construction_args(const Alloc& alloc) noexcept;   // since C++20
882template<class T, class Alloc, class U, class V>
883  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
884                                                  U&& u, V&& v) noexcept;
885template<class T, class Alloc, class U, class V>
886  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++23
887                                                  pair<U, V>& pr) noexcept;
888template<class T, class Alloc, class U, class V>
889  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
890                                                  const pair<U, V>& pr) noexcept;
891template<class T, class Alloc, class U, class V>
892  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
893                                                  pair<U, V>&& pr) noexcept;
894template<class T, class Alloc, class U, class V>
895  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++23
896                                                  const pair<U, V>&& pr) noexcept;
897template<class T, class Alloc, pair-like P>
898  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
899                                                  P&& p) noexcept;
900template<class T, class Alloc, class U>
901  constexpr auto uses_allocator_construction_args(const Alloc& alloc,             // since C++20
902                                                  U&& u) noexcept;
903template<class T, class Alloc, class... Args>
904  constexpr T make_obj_using_allocator(const Alloc& alloc, Args&&... args);       // since C++20
905template<class T, class Alloc, class... Args>
906  constexpr T* uninitialized_construct_using_allocator(T* p,                      // since C++20
907                                                         const Alloc& alloc, Args&&... args);
908
909// [ptr.align]
910void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
911
912template<size_t N, class T>
913[[nodiscard]] constexpr T* assume_aligned(T* ptr); // since C++20
914
915}  // std
916
917*/
918
919// clang-format on
920
921#include <__assert> // all public C++ headers provide the assertion handler
922#include <__config>
923#include <__memory/addressof.h>
924#include <__memory/align.h>
925#include <__memory/allocate_at_least.h>
926#include <__memory/allocation_guard.h>
927#include <__memory/allocator.h>
928#include <__memory/allocator_arg_t.h>
929#include <__memory/allocator_traits.h>
930#include <__memory/assume_aligned.h>
931#include <__memory/auto_ptr.h>
932#include <__memory/compressed_pair.h>
933#include <__memory/concepts.h>
934#include <__memory/construct_at.h>
935#include <__memory/pointer_traits.h>
936#include <__memory/ranges_construct_at.h>
937#include <__memory/ranges_uninitialized_algorithms.h>
938#include <__memory/raw_storage_iterator.h>
939#include <__memory/shared_ptr.h>
940#include <__memory/temporary_buffer.h>
941#include <__memory/uninitialized_algorithms.h>
942#include <__memory/unique_ptr.h>
943#include <__memory/uses_allocator.h>
944#include <__memory/uses_allocator_construction.h>
945#include <version>
946
947// standard-mandated includes
948
949// [memory.syn]
950#include <compare>
951
952#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
953#  pragma GCC system_header
954#endif
955
956#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
957#  include <atomic>
958#  include <concepts>
959#  include <cstddef>
960#  include <cstdint>
961#  include <cstdlib>
962#  include <cstring>
963#  include <iosfwd>
964#  include <iterator>
965#  include <new>
966#  include <stdexcept>
967#  include <tuple>
968#  include <type_traits>
969#  include <typeinfo>
970#  include <utility>
971#endif
972
973#endif // _LIBCPP_MEMORY
974