xref: /freebsd/contrib/llvm-project/libcxx/include/memory (revision 0ad011ececb978e22a9bff2acf76633b094f1ff6)
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/*
14    memory synopsis
15
16namespace std
17{
18
19struct allocator_arg_t { };
20inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();
21
22template <class T, class Alloc> struct uses_allocator;
23
24template <class Ptr>
25struct pointer_traits
26{
27    typedef Ptr pointer;
28    typedef <details> element_type;
29    typedef <details> difference_type;
30
31    template <class U> using rebind = <details>;
32
33    static pointer pointer_to(<details>);
34};
35
36template <class T>
37struct pointer_traits<T*>
38{
39    typedef T* pointer;
40    typedef T element_type;
41    typedef ptrdiff_t difference_type;
42
43    template <class U> using rebind = U*;
44
45    static pointer pointer_to(<details>) noexcept; // constexpr in C++20
46};
47
48template <class T> constexpr T* to_address(T* p) noexcept; // C++20
49template <class Ptr> constexpr auto to_address(const Ptr& p) noexcept; // C++20
50
51template <class Alloc>
52struct allocator_traits
53{
54    typedef Alloc                        allocator_type;
55    typedef typename allocator_type::value_type
56                                         value_type;
57
58    typedef Alloc::pointer | value_type* pointer;
59    typedef Alloc::const_pointer
60          | pointer_traits<pointer>::rebind<const value_type>
61                                         const_pointer;
62    typedef Alloc::void_pointer
63          | pointer_traits<pointer>::rebind<void>
64                                         void_pointer;
65    typedef Alloc::const_void_pointer
66          | pointer_traits<pointer>::rebind<const void>
67                                         const_void_pointer;
68    typedef Alloc::difference_type
69          | pointer_traits<pointer>::difference_type
70                                         difference_type;
71    typedef Alloc::size_type
72          | make_unsigned<difference_type>::type
73                                         size_type;
74    typedef Alloc::propagate_on_container_copy_assignment
75          | false_type                   propagate_on_container_copy_assignment;
76    typedef Alloc::propagate_on_container_move_assignment
77          | false_type                   propagate_on_container_move_assignment;
78    typedef Alloc::propagate_on_container_swap
79          | false_type                   propagate_on_container_swap;
80    typedef Alloc::is_always_equal
81          | is_empty                     is_always_equal;
82
83    template <class T> using rebind_alloc  = Alloc::rebind<T>::other | Alloc<T, Args...>;
84    template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
85
86    static pointer allocate(allocator_type& a, size_type n);                          // constexpr and [[nodiscard]] in C++20
87    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint); // constexpr and [[nodiscard]] in C++20
88
89    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept; // constexpr in C++20
90
91    template <class T, class... Args>
92    static void construct(allocator_type& a, T* p, Args&&... args); // constexpr in C++20
93
94    template <class T>
95    static void destroy(allocator_type& a, T* p); // constexpr in C++20
96
97    static size_type max_size(const allocator_type& a); // noexcept in C++14, constexpr in C++20
98    static allocator_type select_on_container_copy_construction(const allocator_type& a); // constexpr in C++20
99};
100
101template<class Pointer>
102struct allocation_result {
103    Pointer ptr;
104    size_t count;
105}; // since C++23
106
107template<class Allocator>
108[[nodiscard]] constexpr allocation_result<typename allocator_traits<Allocator>::pointer>
109    allocate_at_least(Allocator& a, size_t n); // since C++23
110
111template <>
112class allocator<void> // removed in C++20
113{
114public:
115    typedef void*                                 pointer;
116    typedef const void*                           const_pointer;
117    typedef void                                  value_type;
118
119    template <class _Up> struct rebind {typedef allocator<_Up> other;};
120};
121
122template <class T>
123class allocator
124{
125public:
126    typedef size_t    size_type;
127    typedef ptrdiff_t difference_type;
128    typedef T*        pointer;                           // deprecated in C++17, removed in C++20
129    typedef const T*  const_pointer;                     // deprecated in C++17, removed in C++20
130    typedef typename add_lvalue_reference<T>::type
131                      reference;                         // deprecated in C++17, removed in C++20
132    typedef typename add_lvalue_reference<const T>::type
133                      const_reference;                   // deprecated in C++17, removed in C++20
134
135    typedef T         value_type;
136
137    template <class U> struct rebind {typedef allocator<U> other;}; // deprecated in C++17, removed in C++20
138
139    typedef true_type propagate_on_container_move_assignment;
140    typedef true_type is_always_equal;
141
142    constexpr allocator() noexcept;                      // constexpr in C++20
143    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
144    template <class U>
145      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
146    ~allocator();                                        // constexpr in C++20
147    pointer address(reference x) const noexcept;             // deprecated in C++17, removed in C++20
148    const_pointer address(const_reference x) const noexcept; // deprecated in C++17, removed in C++20
149    T* allocate(size_t n, const void* hint);          // deprecated in C++17, removed in C++20
150    T* allocate(size_t n);                              // constexpr in C++20
151    void deallocate(T* p, size_t n) noexcept;           // constexpr in C++20
152    size_type max_size() const noexcept;              // deprecated in C++17, removed in C++20
153    template<class U, class... Args>
154        void construct(U* p, Args&&... args);         // deprecated in C++17, removed in C++20
155    template <class U>
156        void destroy(U* p);                           // deprecated in C++17, removed in C++20
157};
158
159template <class T, class U>
160bool operator==(const allocator<T>&, const allocator<U>&) noexcept; // constexpr in C++20
161
162template <class T, class U>
163bool operator!=(const allocator<T>&, const allocator<U>&) noexcept; // removed in C++20
164
165template <class OutputIterator, class T>
166class raw_storage_iterator // deprecated in C++17, removed in C++20
167    : public iterator<output_iterator_tag, void, void, void, void> // until C++17
168{
169public:
170    typedef output_iterator_tag iterator_category;
171    typedef void                value_type;
172    typedef void                difference_type; // until C++20
173    typedef ptrdiff_t           difference_type; // since C++20
174    typedef void                pointer;
175    typedef void                reference;
176
177    explicit raw_storage_iterator(OutputIterator x);
178    raw_storage_iterator& operator*();
179    raw_storage_iterator& operator=(const T& element);
180    raw_storage_iterator& operator++();
181    raw_storage_iterator  operator++(int);
182};
183
184template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
185template <class T> void               return_temporary_buffer(T* p) noexcept;
186
187template <class T> T* addressof(T& r) noexcept;
188template <class T> T* addressof(const T&& r) noexcept = delete;
189
190template <class InputIterator, class ForwardIterator>
191ForwardIterator
192uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
193
194namespace ranges {
195
196template<class InputIterator, class OutputIterator>
197using uninitialized_copy_result = in_out_result<InputIterator, OutputIterator>; // since C++20
198
199template<input_iterator InputIterator, sentinel-for<InputIterator> Sentinel1, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel2>
200  requires constructible_from<iter_value_t<OutputIterator>, iter_reference_t<InputIterator>>
201uninitialized_copy_result<InputIterator, OutputIterator>
202uninitialized_copy(InputIterator ifirst, Sentinel1 ilast, OutputIterator ofirst, Sentinel2 olast); // since C++20
203
204template<input_range InputRange, nothrow-forward-range OutputRange>
205  requires constructible_from<range_value_t<OutputRange>, range_reference_t<InputRange>>
206uninitialized_copy_result<borrowed_iterator_t<InputRange>, borrowed_iterator_t<OutputRange>>
207uninitialized_copy(InputRange&& in_range, OutputRange&& out_range); // since C++20
208
209}
210
211template <class InputIterator, class Size, class ForwardIterator>
212ForwardIterator
213uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
214
215namespace ranges {
216
217template<class InputIterator, class OutputIterator>
218using uninitialized_copy_n_result = in_out_result<InputIterator, OutputIterator>; // since C++20
219
220template<input_iterator InputIterator, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel>
221  requires constructible_from<iter_value_t<OutputIterator>, iter_reference_t<InputIterator>>
222uninitialized_copy_n_result<InputIterator, OutputIterator>
223uninitialized_copy_n(InputIterator ifirst, iter_difference_t<InputIterator> n, OutputIterator ofirst, Sentinel olast); // since C++20
224
225}
226
227template <class ForwardIterator, class T>
228void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
229
230namespace ranges {
231
232template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel, class T>
233  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
234ForwardIterator uninitialized_fill(ForwardIterator first, Sentinel last, const T& x); // since C++20
235
236template <nothrow-forward-range ForwardRange, class T>
237  requires constructible_from<range_value_t<ForwardRange>, const T&>
238borrowed_iterator_t<ForwardRange> uninitialized_fill(ForwardRange&& range, const T& x); // since C++20
239
240}
241
242template <class ForwardIterator, class Size, class T>
243ForwardIterator
244uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
245
246namespace ranges {
247
248template <nothrow-forward-iterator ForwardIterator, class T>
249  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
250ForwardIterator uninitialized_fill_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
251
252}
253
254template <class T, class ...Args>
255constexpr T* construct_at(T* location, Args&& ...args); // since C++20
256
257namespace ranges {
258  template<class T, class... Args>
259    constexpr T* construct_at(T* location, Args&&... args); // since C++20
260}
261
262template <class T>
263void destroy_at(T* location); // constexpr in C++20
264
265namespace ranges {
266  template<destructible T>
267    constexpr void destroy_at(T* location) noexcept; // since C++20
268}
269
270template <class ForwardIterator>
271void destroy(ForwardIterator first, ForwardIterator last); // constexpr in C++20
272
273namespace ranges {
274  template<nothrow-input-iterator InputIterator, nothrow-sentinel-for<InputIterator> Sentinel>
275    requires destructible<iter_value_t<InputIterator>>
276    constexpr InputIterator destroy(InputIterator first, Sentinel last) noexcept; // since C++20
277  template<nothrow-input-range InputRange>
278    requires destructible<range_value_t<InputRange>>
279    constexpr borrowed_iterator_t<InputRange> destroy(InputRange&& range) noexcept; // since C++20
280}
281
282template <class ForwardIterator, class Size>
283ForwardIterator destroy_n(ForwardIterator first, Size n); // constexpr in C++20
284
285namespace ranges {
286  template<nothrow-input-iterator InputIterator>
287    requires destructible<iter_value_t<InputIterator>>
288    constexpr InputIterator destroy_n(InputIterator first, iter_difference_t<InputIterator> n) noexcept; // since C++20
289}
290
291template <class InputIterator, class ForwardIterator>
292 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
293
294namespace ranges {
295
296template<class InputIterator, class OutputIterator>
297using uninitialized_move_result = in_out_result<InputIterator, OutputIterator>; // since C++20
298
299template <input_iterator InputIterator, sentinel_for<InputIterator> Sentinel1, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<O> Sentinel2>
300  requires constructible_from<iter_value_t<OutputIterator>, iter_rvalue_reference_t<InputIterator>>
301uninitialized_move_result<InputIterator, OutputIterator>
302uninitialized_move(InputIterator ifirst, Sentinel1 ilast, OutputIterator ofirst, Sentinel2 olast); // since C++20
303
304template<input_range InputRange, nothrow-forward-range OutputRange>
305  requires constructible_from<range_value_t<OutputRange>, range_rvalue_reference_t<InputRange>>
306uninitialized_move_result<borrowed_iterator_t<InputRange>, borrowed_iterator_t<OutputRange>>
307uninitialized_move(InputRange&& in_range, OutputRange&& out_range); // since C++20
308
309}
310
311template <class InputIterator, class Size, class ForwardIterator>
312 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
313
314namespace ranges {
315
316template<class InputIterator, class OutputIterator>
317using uninitialized_move_n_result = in_out_result<InputIterator, OutputIterator>; // since C++20
318
319template<input_iterator InputIterator, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel>
320  requires constructible_from<iter_value_t<OutputIterator>, iter_rvalue_reference_t<InputIterator>>
321uninitialized_move_n_result<InputIterator, OutputIterator>
322uninitialized_move_n(InputIterator ifirst, iter_difference_t<InputIterator> n, OutputIterator ofirst, Sentinel olast); // since C++20
323
324}
325
326template <class ForwardIterator>
327 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
328
329namespace ranges {
330
331template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
332  requires default_initializable<iter_value_t<ForwardIterator>>
333 ForwardIterator uninitialized_value_construct(ForwardIterator first, Sentinel last); // since C++20
334
335template <nothrow-forward-range ForwardRange>
336  requires default_initializable<range_value_t<ForwardRange>>
337 borrowed_iterator_t<ForwardRange> uninitialized_value_construct(ForwardRange&& r); // since C++20
338
339}
340
341template <class ForwardIterator, class Size>
342 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
343
344namespace ranges {
345
346template <nothrow-forward-iterator ForwardIterator>
347  requires default_initializable<iter_value_t<ForwardIterator>>
348 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
349
350}
351
352template <class ForwardIterator>
353 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
354
355namespace ranges {
356
357template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
358  requires default_initializable<iter_value_t<ForwardIterator>>
359 ForwardIterator uninitialized_default_construct(ForwardIterator first, Sentinel last); // since C++20
360
361template <nothrow-forward-range ForwardRange>
362  requires default_initializable<range_value_t<ForwardRange>>
363 borrowed_iterator_t<ForwardRange> uninitialized_default_construct(ForwardRange&& r); // since C++20
364
365}
366
367template <class ForwardIterator, class Size>
368 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
369
370namespace ranges {
371
372template <nothrow-forward-iterator ForwardIterator>
373  requires default_initializable<iter_value_t<ForwardIterator>>
374 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
375
376}
377
378template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
379
380template<class X>
381class auto_ptr                                  // deprecated in C++11, removed in C++17
382{
383public:
384    typedef X element_type;
385
386    explicit auto_ptr(X* p =0) throw();
387    auto_ptr(auto_ptr&) throw();
388    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
389    auto_ptr& operator=(auto_ptr&) throw();
390    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
391    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
392    ~auto_ptr() throw();
393
394    typename add_lvalue_reference<X>::type operator*() const throw();
395    X* operator->() const throw();
396    X* get() const throw();
397    X* release() throw();
398    void reset(X* p =0) throw();
399
400    auto_ptr(auto_ptr_ref<X>) throw();
401    template<class Y> operator auto_ptr_ref<Y>() throw();
402    template<class Y> operator auto_ptr<Y>() throw();
403};
404
405template <class T>
406struct default_delete
407{
408    constexpr default_delete() noexcept = default;
409    template <class U> constexpr default_delete(const default_delete<U>&) noexcept; // constexpr since C++23
410
411    constexpr void operator()(T*) const noexcept;                                   // constexpr since C++23
412};
413
414template <class T>
415struct default_delete<T[]>
416{
417    constexpr default_delete() noexcept = default;
418    template <class U> constexpr default_delete(const default_delete <U[]>&) noexcept; // constexpr since C++23
419    constexpr void operator()(T*) const noexcept;                                      // constexpr since C++23
420    template <class U> void operator()(U*) const = delete;
421};
422
423template <class T, class D = default_delete<T>>
424class unique_ptr
425{
426public:
427    typedef see below pointer;
428    typedef T element_type;
429    typedef D deleter_type;
430
431    // constructors
432    constexpr unique_ptr() noexcept;
433    constexpr explicit unique_ptr(pointer p) noexcept;           // constexpr since C++23
434    constexpr unique_ptr(pointer p, see below d1) noexcept;      // constexpr since C++23
435    constexpr unique_ptr(pointer p, see below d2) noexcept;      // constexpr since C++23
436    constexpr unique_ptr(unique_ptr&& u) noexcept;               // constexpr since C++23
437    constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
438    template <class U, class E>
439        constexpr unique_ptr(unique_ptr<U, E>&& u) noexcept;     // constexpr since C++23
440    template <class U>
441        unique_ptr(auto_ptr<U>&& u) noexcept;                    // removed in C++17
442
443    // destructor
444    constexpr ~unique_ptr();                                     // constexpr since C++23
445
446    // assignment
447    constexpr unique_ptr& operator=(unique_ptr&& u) noexcept;                         // constexpr since C++23
448    template <class U, class E>
449    constexpr unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;                   // constexpr since C++23
450    constexpr unique_ptr& operator=(nullptr_t) noexcept;                              // constexpr since C++23
451
452    // observers
453    typename constexpr add_lvalue_reference<T>::type operator*() const;               // constexpr since C++23
454    constexpr pointer operator->() const noexcept;                                    // constexpr since C++23
455    constexpr pointer get() const noexcept;                                           // constexpr since C++23
456    constexpr deleter_type& get_deleter() noexcept;                                   // constexpr since C++23
457    constexpr const deleter_type& get_deleter() const noexcept;                       // constexpr since C++23
458    constexpr explicit operator bool() const noexcept;                                // constexpr since C++23
459
460    // modifiers
461    constexpr pointer release() noexcept;                                             // constexpr since C++23
462    constexpr void reset(pointer p = pointer()) noexcept;                             // constexpr since C++23
463    constexpr void swap(unique_ptr& u) noexcept;                                      // constexpr since C++23
464};
465
466template <class T, class D>
467class unique_ptr<T[], D>
468{
469public:
470    typedef implementation-defined pointer;
471    typedef T element_type;
472    typedef D deleter_type;
473
474    // constructors
475    constexpr unique_ptr() noexcept;
476    constexpr explicit unique_ptr(pointer p) noexcept;          // constexpr since C++23
477    constexpr unique_ptr(pointer p, see below d) noexcept;      // constexpr since C++23
478    constexpr unique_ptr(pointer p, see below d) noexcept;      // constexpr since C++23
479    constexpr unique_ptr(unique_ptr&& u) noexcept;              // constexpr since C++23
480    template <class U, class E>
481    constexpr unique_ptr(unique_ptr <U, E>&& u) noexcept;       // constexpr since C++23
482    constexpr unique_ptr(nullptr_t) noexcept : unique_ptr() { }
483
484    // destructor
485    constexpr ~unique_ptr();                                    // constexpr since C++23
486
487    // assignment
488    constexpr unique_ptr& operator=(unique_ptr&& u) noexcept;        // constexpr since C++23
489    template <class U, class E>
490    constexpr unique_ptr& operator=(unique_ptr <U, E>&& u) noexcept; // constexpr since C++23
491    constexpr unique_ptr& operator=(nullptr_t) noexcept;             // constexpr since C++23
492
493    // observers
494    constexpr T& operator[](size_t i) const;                    // constexpr since C++23
495    constexpr pointer get() const noexcept;                     // constexpr since C++23
496    constexpr deleter_type& get_deleter() noexcept;             // constexpr since C++23
497    constexpr const deleter_type& get_deleter() const noexcept; // constexpr since C++23
498    constexpr explicit operator bool() const noexcept;          // constexpr since C++23
499
500    // modifiers
501    constexpr pointer release() noexcept;                       // constexpr since C++23
502    constexpr void reset(pointer p = pointer()) noexcept;       // constexpr since C++23
503    constexpr void reset(nullptr_t) noexcept;                   // constexpr since C++23
504  template <class U> void reset(U) = delete;
505    constexpr void swap(unique_ptr& u) noexcept;                // constexpr since C++23
506};
507
508template <class T, class D>
509    constexpr void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;                 // constexpr since C++23
510
511template <class T1, class D1, class T2, class D2>
512    constexpr bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);    // constexpr since C++23
513template <class T1, class D1, class T2, class D2>
514    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);              // removed in C++20
515template <class T1, class D1, class T2, class D2>
516    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
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  requires three_way_comparable_with<typename unique_ptr<T1, D1>::pointer,
525                                     typename unique_ptr<T2, D2>::pointer>
526  compare_three_way_result_t<typename unique_ptr<T1, D1>::pointer,
527                             typename unique_ptr<T2, D2>::pointer>
528    operator<=>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);      // C++20
529
530template <class T, class D>
531    constexpr bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;   // constexpr since C++23
532template <class T, class D>
533    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;             // removed in C++20
534template <class T, class D>
535    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;             // removed in C++20
536template <class T, class D>
537    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;             // removed in C++20
538
539template <class T, class D>
540    constexpr bool operator<(const unique_ptr<T, D>& x, nullptr_t);     // constexpr since C++23
541template <class T, class D>
542    constexpr bool operator<(nullptr_t, const unique_ptr<T, D>& y);     // constexpr since C++23
543template <class T, class D>
544    constexpr bool operator<=(const unique_ptr<T, D>& x, nullptr_t);    // constexpr since C++23
545template <class T, class D>
546    constexpr bool operator<=(nullptr_t, const unique_ptr<T, D>& y);    // constexpr since C++23
547template <class T, class D>
548    constexpr bool operator>(const unique_ptr<T, D>& x, nullptr_t);     // constexpr since C++23
549template <class T, class D>
550    constexpr bool operator>(nullptr_t, const unique_ptr<T, D>& y);     // constexpr since C++23
551template <class T, class D>
552    constexpr bool operator>=(const unique_ptr<T, D>& x, nullptr_t);    // constexpr since C++23
553template <class T, class D>
554    constexpr bool operator>=(nullptr_t, const unique_ptr<T, D>& y);    // constexpr since C++23
555template<class T, class D>
556  requires three_way_comparable<typename unique_ptr<T, D>::pointer>
557  compare_three_way_result_t<typename unique_ptr<T, D>::pointer>
558    constexpr operator<=>(const unique_ptr<T, D>& x, nullptr_t);        // C++20, constexpr since C++23
559
560class bad_weak_ptr
561    : public std::exception
562{
563    bad_weak_ptr() noexcept;
564};
565
566template<class T, class... Args>
567constexpr unique_ptr<T> make_unique(Args&&... args);                            // C++14, constexpr since C++23
568template<class T>
569constexpr unique_ptr<T> make_unique(size_t n);                                  // C++14, constexpr since C++23
570template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
571
572template<class T>
573  constexpr unique_ptr<T> make_unique_for_overwrite();                        // T is not array, C++20, constexpr since C++23
574template<class T>
575  constexpr unique_ptr<T> make_unique_for_overwrite(size_t n);                // T is U[], C++20, constexpr since C++23
576template<class T, class... Args>
577  unspecified make_unique_for_overwrite(Args&&...) = delete;                  // T is U[N], C++20
578
579template<class E, class T, class Y, class D>
580    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
581
582template<class T>
583class shared_ptr
584{
585public:
586    typedef T element_type; // until C++17
587    typedef remove_extent_t<T> element_type; // since C++17
588    typedef weak_ptr<T> weak_type; // C++17
589
590    // constructors:
591    constexpr shared_ptr() noexcept;
592    template<class Y> explicit shared_ptr(Y* p);
593    template<class Y, class D> shared_ptr(Y* p, D d);
594    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
595    template <class D> shared_ptr(nullptr_t p, D d);
596    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
597    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
598    shared_ptr(const shared_ptr& r) noexcept;
599    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
600    shared_ptr(shared_ptr&& r) noexcept;
601    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
602    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
603    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
604    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
605    shared_ptr(nullptr_t) : shared_ptr() { }
606
607    // destructor:
608    ~shared_ptr();
609
610    // assignment:
611    shared_ptr& operator=(const shared_ptr& r) noexcept;
612    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
613    shared_ptr& operator=(shared_ptr&& r) noexcept;
614    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
615    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
616    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
617
618    // modifiers:
619    void swap(shared_ptr& r) noexcept;
620    void reset() noexcept;
621    template<class Y> void reset(Y* p);
622    template<class Y, class D> void reset(Y* p, D d);
623    template<class Y, class D, class A> void reset(Y* p, D d, A a);
624
625    // observers:
626    T* get() const noexcept;
627    T& operator*() const noexcept;
628    T* operator->() const noexcept;
629    long use_count() const noexcept;
630    bool unique() const noexcept;
631    explicit operator bool() const noexcept;
632    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
633    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
634};
635
636template<class T>
637shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
638template<class T, class D>
639shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
640
641// shared_ptr comparisons:
642template<class T, class U>
643    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
644template<class T, class U>
645    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;               // removed in C++20
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    strong_ordering operator<=>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;   // C++20
656
657template <class T>
658    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
659template <class T>
660    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
661template <class T>
662    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;               // removed in C++20
663template <class T>
664    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
665template <class T>
666    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;                // removed in C++20
667template <class T>
668    bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;                // removed in C++20
669template <class T>
670    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;               // removed in C++20
671template <class T>
672    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
673template <class T>
674    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;                // removed in C++20
675template <class T>
676    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;                // removed in C++20
677template <class T>
678    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;               // removed in C++20
679template <class T>
680    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;               // removed in C++20
681template<class T>
682    strong_ordering operator<=>(shared_ptr<T> const& x, nullptr_t) noexcept;   // C++20
683
684// shared_ptr specialized algorithms:
685template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
686
687// shared_ptr casts:
688template<class T, class U>
689    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
690template<class T, class U>
691    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
692template<class T, class U>
693    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
694
695// shared_ptr I/O:
696template<class E, class T, class Y>
697    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
698
699// shared_ptr get_deleter:
700template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
701
702template<class T, class... Args>
703    shared_ptr<T> make_shared(Args&&... args); // T is not an array
704template<class T, class A, class... Args>
705    shared_ptr<T> allocate_shared(const A& a, Args&&... args); // T is not an array
706
707template<class T>
708    shared_ptr<T> make_shared(size_t N); // T is U[] (since C++20)
709template<class T, class A>
710    shared_ptr<T> allocate_shared(const A& a, size_t N); // T is U[] (since C++20)
711
712template<class T>
713    shared_ptr<T> make_shared(); // T is U[N] (since C++20)
714template<class T, class A>
715    shared_ptr<T> allocate_shared(const A& a); // T is U[N] (since C++20)
716
717template<class T>
718    shared_ptr<T> make_shared(size_t N, const remove_extent_t<T>& u); // T is U[] (since C++20)
719template<class T, class A>
720    shared_ptr<T> allocate_shared(const A& a, size_t N, const remove_extent_t<T>& u); // T is U[] (since C++20)
721
722template<class T> shared_ptr<T>
723    make_shared(const remove_extent_t<T>& u); // T is U[N] (since C++20)
724template<class T, class A>
725    shared_ptr<T> allocate_shared(const A& a, const remove_extent_t<T>& u); // T is U[N] (since C++20)
726
727template<class T>
728  shared_ptr<T> make_shared_for_overwrite();                                  // T is not U[], C++20
729template<class T, class A>
730  shared_ptr<T> allocate_shared_for_overwrite(const A& a);                    // T is not U[], C++20
731
732template<class T>
733  shared_ptr<T> make_shared_for_overwrite(size_t N);                          // T is U[], C++20
734template<class T, class A>
735  shared_ptr<T> allocate_shared_for_overwrite(const A& a, size_t N);          // T is U[], C++20
736
737template<class T>
738class weak_ptr
739{
740public:
741    typedef T element_type; // until C++17
742    typedef remove_extent_t<T> element_type; // since C++17
743
744    // constructors
745    constexpr weak_ptr() noexcept;
746    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
747    weak_ptr(weak_ptr const& r) noexcept;
748    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
749    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
750    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
751
752    // destructor
753    ~weak_ptr();
754
755    // assignment
756    weak_ptr& operator=(weak_ptr const& r) noexcept;
757    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
758    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
759    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
760    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
761
762    // modifiers
763    void swap(weak_ptr& r) noexcept;
764    void reset() noexcept;
765
766    // observers
767    long use_count() const noexcept;
768    bool expired() const noexcept;
769    shared_ptr<T> lock() const noexcept;
770    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
771    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
772};
773
774template<class T>
775weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
776
777// weak_ptr specialized algorithms:
778template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
779
780// class owner_less:
781template<class T> struct owner_less;
782
783template<class T>
784struct owner_less<shared_ptr<T> >
785    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
786{
787    typedef bool result_type;
788    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
789    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
790    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
791};
792
793template<class T>
794struct owner_less<weak_ptr<T> >
795    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
796{
797    typedef bool result_type;
798    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
799    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
800    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
801};
802
803template <>  // Added in C++14
804struct owner_less<void>
805{
806    template <class _Tp, class _Up>
807    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
808    template <class _Tp, class _Up>
809    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
810    template <class _Tp, class _Up>
811    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
812    template <class _Tp, class _Up>
813    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
814
815    typedef void is_transparent;
816};
817
818template<class T>
819class enable_shared_from_this
820{
821protected:
822    constexpr enable_shared_from_this() noexcept;
823    enable_shared_from_this(enable_shared_from_this const&) noexcept;
824    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
825    ~enable_shared_from_this();
826public:
827    shared_ptr<T> shared_from_this();
828    shared_ptr<T const> shared_from_this() const;
829};
830
831template<class T>
832    bool atomic_is_lock_free(const shared_ptr<T>* p);
833template<class T>
834    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
835template<class T>
836    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
837template<class T>
838    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
839template<class T>
840    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
841template<class T>
842    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
843template<class T>
844    shared_ptr<T>
845    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
846template<class T>
847    bool
848    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
849template<class T>
850    bool
851    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
852template<class T>
853    bool
854    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
855                                          shared_ptr<T> w, memory_order success,
856                                          memory_order failure);
857template<class T>
858    bool
859    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
860                                            shared_ptr<T> w, memory_order success,
861                                            memory_order failure);
862// Hash support
863template <class T> struct hash;
864template <class T, class D> struct hash<unique_ptr<T, D> >;
865template <class T> struct hash<shared_ptr<T> >;
866
867template <class T, class Alloc>
868  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
869
870// [ptr.align]
871void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
872
873template<size_t N, class T>
874[[nodiscard]] constexpr T* assume_aligned(T* ptr); // since C++20
875
876}  // std
877
878*/
879
880#include <__assert> // all public C++ headers provide the assertion handler
881#include <__config>
882#include <__memory/addressof.h>
883#include <__memory/align.h>
884#include <__memory/allocate_at_least.h>
885#include <__memory/allocation_guard.h>
886#include <__memory/allocator.h>
887#include <__memory/allocator_arg_t.h>
888#include <__memory/allocator_traits.h>
889#include <__memory/assume_aligned.h>
890#include <__memory/auto_ptr.h>
891#include <__memory/compressed_pair.h>
892#include <__memory/concepts.h>
893#include <__memory/construct_at.h>
894#include <__memory/pointer_traits.h>
895#include <__memory/ranges_construct_at.h>
896#include <__memory/ranges_uninitialized_algorithms.h>
897#include <__memory/raw_storage_iterator.h>
898#include <__memory/shared_ptr.h>
899#include <__memory/temporary_buffer.h>
900#include <__memory/uninitialized_algorithms.h>
901#include <__memory/unique_ptr.h>
902#include <__memory/uses_allocator.h>
903#include <__memory/uses_allocator_construction.h>
904#include <version>
905
906// standard-mandated includes
907
908// [memory.syn]
909#include <compare>
910
911#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
912#  pragma GCC system_header
913#endif
914
915#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
916#  include <atomic>
917#  include <concepts>
918#  include <cstddef>
919#  include <cstdint>
920#  include <cstdlib>
921#  include <cstring>
922#  include <iosfwd>
923#  include <iterator>
924#  include <new>
925#  include <stdexcept>
926#  include <tuple>
927#  include <type_traits>
928#  include <typeinfo>
929#  include <utility>
930#endif
931
932#endif // _LIBCPP_MEMORY
933