xref: /freebsd/contrib/llvm-project/libcxx/include/memory (revision 0eae32dcef82f6f06de6419a0d623d7def0cc8f6)
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 <>
102class allocator<void> // removed in C++20
103{
104public:
105    typedef void*                                 pointer;
106    typedef const void*                           const_pointer;
107    typedef void                                  value_type;
108
109    template <class _Up> struct rebind {typedef allocator<_Up> other;};
110};
111
112template <class T>
113class allocator
114{
115public:
116    typedef size_t    size_type;
117    typedef ptrdiff_t difference_type;
118    typedef T*        pointer;                           // deprecated in C++17, removed in C++20
119    typedef const T*  const_pointer;                     // deprecated in C++17, removed in C++20
120    typedef typename add_lvalue_reference<T>::type
121                      reference;                         // deprecated in C++17, removed in C++20
122    typedef typename add_lvalue_reference<const T>::type
123                      const_reference;                   // deprecated in C++17, removed in C++20
124
125    typedef T         value_type;
126
127    template <class U> struct rebind {typedef allocator<U> other;}; // deprecated in C++17, removed in C++20
128
129    typedef true_type propagate_on_container_move_assignment;
130    typedef true_type is_always_equal;
131
132    constexpr allocator() noexcept;                      // constexpr in C++20
133    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
134    template <class U>
135      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
136    ~allocator();                                        // constexpr in C++20
137    pointer address(reference x) const noexcept;             // deprecated in C++17, removed in C++20
138    const_pointer address(const_reference x) const noexcept; // deprecated in C++17, removed in C++20
139    T* allocate(size_t n, const void* hint);          // deprecated in C++17, removed in C++20
140    T* allocate(size_t n);                              // constexpr in C++20
141    void deallocate(T* p, size_t n) noexcept;           // constexpr in C++20
142    size_type max_size() const noexcept;              // deprecated in C++17, removed in C++20
143    template<class U, class... Args>
144        void construct(U* p, Args&&... args);         // deprecated in C++17, removed in C++20
145    template <class U>
146        void destroy(U* p);                           // deprecated in C++17, removed in C++20
147};
148
149template <class T, class U>
150bool operator==(const allocator<T>&, const allocator<U>&) noexcept; // constexpr in C++20
151
152template <class T, class U>
153bool operator!=(const allocator<T>&, const allocator<U>&) noexcept; // constexpr in C++20
154
155template <class OutputIterator, class T>
156class raw_storage_iterator // deprecated in C++17, removed in C++20
157    : public iterator<output_iterator_tag, void, void, void, void> // until C++17
158{
159public:
160    typedef output_iterator_tag iterator_category;
161    typedef void                value_type;
162    typedef void                difference_type; // until C++20
163    typedef ptrdiff_t           difference_type; // since C++20
164    typedef void                pointer;
165    typedef void                reference;
166
167    explicit raw_storage_iterator(OutputIterator x);
168    raw_storage_iterator& operator*();
169    raw_storage_iterator& operator=(const T& element);
170    raw_storage_iterator& operator++();
171    raw_storage_iterator  operator++(int);
172};
173
174template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
175template <class T> void               return_temporary_buffer(T* p) noexcept;
176
177template <class T> T* addressof(T& r) noexcept;
178template <class T> T* addressof(const T&& r) noexcept = delete;
179
180template <class InputIterator, class ForwardIterator>
181ForwardIterator
182uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
183
184template <class InputIterator, class Size, class ForwardIterator>
185ForwardIterator
186uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
187
188template <class ForwardIterator, class T>
189void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
190
191template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel, class T>
192  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
193ForwardIterator ranges::uninitialized_fill(ForwardIterator first, Sentinel last, const T& x); // since C++20
194
195template <nothrow-forward-range ForwardRange, class T>
196  requires constructible_from<range_value_t<ForwardRange>, const T&>
197borrowed_iterator_t<ForwardRange> ranges::uninitialized_fill(ForwardRange&& range, const T& x); // since C++20
198
199template <class ForwardIterator, class Size, class T>
200ForwardIterator
201uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
202
203template <nothrow-forward-iterator ForwardIterator, class T>
204  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
205ForwardIterator ranges::uninitialized_fill_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
206
207template <class T, class ...Args>
208constexpr T* construct_at(T* location, Args&& ...args); // since C++20
209
210template <class T>
211void destroy_at(T* location); // constexpr in C++20
212
213template <class ForwardIterator>
214void destroy(ForwardIterator first, ForwardIterator last); // constexpr in C++20
215
216template <class ForwardIterator, class Size>
217ForwardIterator destroy_n(ForwardIterator first, Size n); // constexpr in C++20
218
219template <class InputIterator, class ForwardIterator>
220 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
221
222template <class InputIterator, class Size, class ForwardIterator>
223 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
224
225template <class ForwardIterator>
226 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
227
228template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
229  requires default_initializable<iter_value_t<ForwardIterator>>
230 ForwardIterator ranges::uninitialized_value_construct(ForwardIterator first, Sentinel last); // since C++20
231
232template <nothrow-forward-range ForwardRange>
233  requires default_initializable<range_value_t<ForwardRange>>
234 borrowed_iterator_t<ForwardRange> ranges::uninitialized_value_construct(ForwardRange&& r); // since C++20
235
236template <class ForwardIterator, class Size>
237 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
238
239template <nothrow-forward-iterator ForwardIterator>
240  requires default_initializable<iter_value_t<ForwardIterator>>
241 ForwardIterator ranges::uninitialized_value_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
242
243template <class ForwardIterator>
244 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
245
246template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
247  requires default_initializable<iter_value_t<ForwardIterator>>
248 ForwardIterator ranges::uninitialized_default_construct(ForwardIterator first, Sentinel last); // since C++20
249
250template <nothrow-forward-range ForwardRange>
251  requires default_initializable<range_value_t<ForwardRange>>
252 borrowed_iterator_t<ForwardRange> ranges::uninitialized_default_construct(ForwardRange&& r); // since C++20
253
254template <class ForwardIterator, class Size>
255 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
256
257template <nothrow-forward-iterator ForwardIterator>
258  requires default_initializable<iter_value_t<ForwardIterator>>
259 ForwardIterator ranges::uninitialized_default_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
260
261template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
262
263template<class X>
264class auto_ptr                                  // deprecated in C++11, removed in C++17
265{
266public:
267    typedef X element_type;
268
269    explicit auto_ptr(X* p =0) throw();
270    auto_ptr(auto_ptr&) throw();
271    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
272    auto_ptr& operator=(auto_ptr&) throw();
273    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
274    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
275    ~auto_ptr() throw();
276
277    typename add_lvalue_reference<X>::type operator*() const throw();
278    X* operator->() const throw();
279    X* get() const throw();
280    X* release() throw();
281    void reset(X* p =0) throw();
282
283    auto_ptr(auto_ptr_ref<X>) throw();
284    template<class Y> operator auto_ptr_ref<Y>() throw();
285    template<class Y> operator auto_ptr<Y>() throw();
286};
287
288template <class T>
289struct default_delete
290{
291    constexpr default_delete() noexcept = default;
292    template <class U> default_delete(const default_delete<U>&) noexcept;
293
294    void operator()(T*) const noexcept;
295};
296
297template <class T>
298struct default_delete<T[]>
299{
300    constexpr default_delete() noexcept = default;
301    void operator()(T*) const noexcept;
302    template <class U> void operator()(U*) const = delete;
303};
304
305template <class T, class D = default_delete<T>>
306class unique_ptr
307{
308public:
309    typedef see below pointer;
310    typedef T element_type;
311    typedef D deleter_type;
312
313    // constructors
314    constexpr unique_ptr() noexcept;
315    explicit unique_ptr(pointer p) noexcept;
316    unique_ptr(pointer p, see below d1) noexcept;
317    unique_ptr(pointer p, see below d2) noexcept;
318    unique_ptr(unique_ptr&& u) noexcept;
319    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
320    template <class U, class E>
321        unique_ptr(unique_ptr<U, E>&& u) noexcept;
322    template <class U>
323        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
324
325    // destructor
326    ~unique_ptr();
327
328    // assignment
329    unique_ptr& operator=(unique_ptr&& u) noexcept;
330    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
331    unique_ptr& operator=(nullptr_t) noexcept;
332
333    // observers
334    typename add_lvalue_reference<T>::type operator*() const;
335    pointer operator->() const noexcept;
336    pointer get() const noexcept;
337    deleter_type& get_deleter() noexcept;
338    const deleter_type& get_deleter() const noexcept;
339    explicit operator bool() const noexcept;
340
341    // modifiers
342    pointer release() noexcept;
343    void reset(pointer p = pointer()) noexcept;
344    void swap(unique_ptr& u) noexcept;
345};
346
347template <class T, class D>
348class unique_ptr<T[], D>
349{
350public:
351    typedef implementation-defined pointer;
352    typedef T element_type;
353    typedef D deleter_type;
354
355    // constructors
356    constexpr unique_ptr() noexcept;
357    explicit unique_ptr(pointer p) noexcept;
358    unique_ptr(pointer p, see below d) noexcept;
359    unique_ptr(pointer p, see below d) noexcept;
360    unique_ptr(unique_ptr&& u) noexcept;
361    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
362
363    // destructor
364    ~unique_ptr();
365
366    // assignment
367    unique_ptr& operator=(unique_ptr&& u) noexcept;
368    unique_ptr& operator=(nullptr_t) noexcept;
369
370    // observers
371    T& operator[](size_t i) const;
372    pointer get() const noexcept;
373    deleter_type& get_deleter() noexcept;
374    const deleter_type& get_deleter() const noexcept;
375    explicit operator bool() const noexcept;
376
377    // modifiers
378    pointer release() noexcept;
379    void reset(pointer p = pointer()) noexcept;
380    void reset(nullptr_t) noexcept;
381  template <class U> void reset(U) = delete;
382    void swap(unique_ptr& u) noexcept;
383};
384
385template <class T, class D>
386    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
387
388template <class T1, class D1, class T2, class D2>
389    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
390template <class T1, class D1, class T2, class D2>
391    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
392template <class T1, class D1, class T2, class D2>
393    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
394template <class T1, class D1, class T2, class D2>
395    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
396template <class T1, class D1, class T2, class D2>
397    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
398template <class T1, class D1, class T2, class D2>
399    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
400
401template <class T, class D>
402    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
403template <class T, class D>
404    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
405template <class T, class D>
406    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
407template <class T, class D>
408    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
409
410template <class T, class D>
411    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
412template <class T, class D>
413    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
414template <class T, class D>
415    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
416template <class T, class D>
417    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
418template <class T, class D>
419    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
420template <class T, class D>
421    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
422template <class T, class D>
423    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
424template <class T, class D>
425    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
426
427class bad_weak_ptr
428    : public std::exception
429{
430    bad_weak_ptr() noexcept;
431};
432
433template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
434template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
435template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
436
437template<class E, class T, class Y, class D>
438    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
439
440template<class T>
441class shared_ptr
442{
443public:
444    typedef T element_type; // until C++17
445    typedef remove_extent_t<T> element_type; // since C++17
446    typedef weak_ptr<T> weak_type; // C++17
447
448    // constructors:
449    constexpr shared_ptr() noexcept;
450    template<class Y> explicit shared_ptr(Y* p);
451    template<class Y, class D> shared_ptr(Y* p, D d);
452    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
453    template <class D> shared_ptr(nullptr_t p, D d);
454    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
455    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
456    shared_ptr(const shared_ptr& r) noexcept;
457    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
458    shared_ptr(shared_ptr&& r) noexcept;
459    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
460    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
461    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
462    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
463    shared_ptr(nullptr_t) : shared_ptr() { }
464
465    // destructor:
466    ~shared_ptr();
467
468    // assignment:
469    shared_ptr& operator=(const shared_ptr& r) noexcept;
470    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
471    shared_ptr& operator=(shared_ptr&& r) noexcept;
472    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
473    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
474    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
475
476    // modifiers:
477    void swap(shared_ptr& r) noexcept;
478    void reset() noexcept;
479    template<class Y> void reset(Y* p);
480    template<class Y, class D> void reset(Y* p, D d);
481    template<class Y, class D, class A> void reset(Y* p, D d, A a);
482
483    // observers:
484    T* get() const noexcept;
485    T& operator*() const noexcept;
486    T* operator->() const noexcept;
487    long use_count() const noexcept;
488    bool unique() const noexcept;
489    explicit operator bool() const noexcept;
490    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
491    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
492};
493
494template<class T>
495shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
496template<class T, class D>
497shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
498
499// shared_ptr comparisons:
500template<class T, class U>
501    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
502template<class T, class U>
503    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
504template<class T, class U>
505    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
506template<class T, class U>
507    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
508template<class T, class U>
509    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
510template<class T, class U>
511    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
512
513template <class T>
514    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
515template <class T>
516    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
517template <class T>
518    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
519template <class T>
520    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
521template <class T>
522    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
523template <class T>
524bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
525template <class T>
526    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
527template <class T>
528    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
529template <class T>
530    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
531template <class T>
532    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
533template <class T>
534    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
535template <class T>
536    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
537
538// shared_ptr specialized algorithms:
539template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
540
541// shared_ptr casts:
542template<class T, class U>
543    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
544template<class T, class U>
545    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
546template<class T, class U>
547    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
548
549// shared_ptr I/O:
550template<class E, class T, class Y>
551    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
552
553// shared_ptr get_deleter:
554template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
555
556template<class T, class... Args>
557    shared_ptr<T> make_shared(Args&&... args);
558template<class T, class A, class... Args>
559    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
560
561template<class T>
562class weak_ptr
563{
564public:
565    typedef T element_type; // until C++17
566    typedef remove_extent_t<T> element_type; // since C++17
567
568    // constructors
569    constexpr weak_ptr() noexcept;
570    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
571    weak_ptr(weak_ptr const& r) noexcept;
572    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
573    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
574    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
575
576    // destructor
577    ~weak_ptr();
578
579    // assignment
580    weak_ptr& operator=(weak_ptr const& r) noexcept;
581    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
582    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
583    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
584    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
585
586    // modifiers
587    void swap(weak_ptr& r) noexcept;
588    void reset() noexcept;
589
590    // observers
591    long use_count() const noexcept;
592    bool expired() const noexcept;
593    shared_ptr<T> lock() const noexcept;
594    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
595    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
596};
597
598template<class T>
599weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
600
601// weak_ptr specialized algorithms:
602template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
603
604// class owner_less:
605template<class T> struct owner_less;
606
607template<class T>
608struct owner_less<shared_ptr<T> >
609    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
610{
611    typedef bool result_type;
612    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
613    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
614    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
615};
616
617template<class T>
618struct owner_less<weak_ptr<T> >
619    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
620{
621    typedef bool result_type;
622    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
623    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
624    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
625};
626
627template <>  // Added in C++14
628struct owner_less<void>
629{
630    template <class _Tp, class _Up>
631    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
632    template <class _Tp, class _Up>
633    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
634    template <class _Tp, class _Up>
635    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
636    template <class _Tp, class _Up>
637    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
638
639    typedef void is_transparent;
640};
641
642template<class T>
643class enable_shared_from_this
644{
645protected:
646    constexpr enable_shared_from_this() noexcept;
647    enable_shared_from_this(enable_shared_from_this const&) noexcept;
648    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
649    ~enable_shared_from_this();
650public:
651    shared_ptr<T> shared_from_this();
652    shared_ptr<T const> shared_from_this() const;
653};
654
655template<class T>
656    bool atomic_is_lock_free(const shared_ptr<T>* p);
657template<class T>
658    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
659template<class T>
660    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
661template<class T>
662    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
663template<class T>
664    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
665template<class T>
666    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
667template<class T>
668    shared_ptr<T>
669    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
670template<class T>
671    bool
672    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
673template<class T>
674    bool
675    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
676template<class T>
677    bool
678    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
679                                          shared_ptr<T> w, memory_order success,
680                                          memory_order failure);
681template<class T>
682    bool
683    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
684                                            shared_ptr<T> w, memory_order success,
685                                            memory_order failure);
686// Hash support
687template <class T> struct hash;
688template <class T, class D> struct hash<unique_ptr<T, D> >;
689template <class T> struct hash<shared_ptr<T> >;
690
691template <class T, class Alloc>
692  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
693
694void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
695
696}  // std
697
698*/
699
700#include <__config>
701#include <__functional_base>
702#include <__memory/addressof.h>
703#include <__memory/allocation_guard.h>
704#include <__memory/allocator.h>
705#include <__memory/allocator_arg_t.h>
706#include <__memory/allocator_traits.h>
707#include <__memory/compressed_pair.h>
708#include <__memory/concepts.h>
709#include <__memory/construct_at.h>
710#include <__memory/pointer_traits.h>
711#include <__memory/ranges_uninitialized_algorithms.h>
712#include <__memory/raw_storage_iterator.h>
713#include <__memory/shared_ptr.h>
714#include <__memory/temporary_buffer.h>
715#include <__memory/uninitialized_algorithms.h>
716#include <__memory/unique_ptr.h>
717#include <__memory/uses_allocator.h>
718#include <compare>
719#include <cstddef>
720#include <cstdint>
721#include <cstring>
722#include <iosfwd>
723#include <iterator>
724#include <new>
725#include <stdexcept>
726#include <tuple>
727#include <type_traits>
728#include <typeinfo>
729#include <utility>
730#include <version>
731
732#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
733#   include <__memory/auto_ptr.h>
734#endif
735
736#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
737#pragma GCC system_header
738#endif
739
740_LIBCPP_BEGIN_NAMESPACE_STD
741
742template <class _Alloc, class _Ptr>
743_LIBCPP_INLINE_VISIBILITY
744void __construct_forward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2) {
745    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
746        "The specified type does not meet the requirements of Cpp17MoveInsertable");
747    typedef allocator_traits<_Alloc> _Traits;
748    for (; __begin1 != __end1; ++__begin1, (void)++__begin2) {
749        _Traits::construct(__a, _VSTD::__to_address(__begin2),
750#ifdef _LIBCPP_NO_EXCEPTIONS
751            _VSTD::move(*__begin1)
752#else
753            _VSTD::move_if_noexcept(*__begin1)
754#endif
755        );
756    }
757}
758
759template <class _Alloc, class _Tp, typename enable_if<
760    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
761    is_trivially_move_constructible<_Tp>::value
762>::type>
763_LIBCPP_INLINE_VISIBILITY
764void __construct_forward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2) {
765    ptrdiff_t _Np = __end1 - __begin1;
766    if (_Np > 0) {
767        _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
768        __begin2 += _Np;
769    }
770}
771
772template <class _Alloc, class _Iter, class _Ptr>
773_LIBCPP_INLINE_VISIBILITY
774void __construct_range_forward(_Alloc& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2) {
775    typedef allocator_traits<_Alloc> _Traits;
776    for (; __begin1 != __end1; ++__begin1, (void) ++__begin2) {
777        _Traits::construct(__a, _VSTD::__to_address(__begin2), *__begin1);
778    }
779}
780
781template <class _Alloc, class _Source, class _Dest,
782          class _RawSource = typename remove_const<_Source>::type,
783          class _RawDest = typename remove_const<_Dest>::type,
784          class =
785    typename enable_if<
786        is_trivially_copy_constructible<_Dest>::value &&
787        is_same<_RawSource, _RawDest>::value &&
788        (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Dest*, _Source&>::value)
789    >::type>
790_LIBCPP_INLINE_VISIBILITY
791void __construct_range_forward(_Alloc&, _Source* __begin1, _Source* __end1, _Dest*& __begin2) {
792    ptrdiff_t _Np = __end1 - __begin1;
793    if (_Np > 0) {
794        _VSTD::memcpy(const_cast<_RawDest*>(__begin2), __begin1, _Np * sizeof(_Dest));
795        __begin2 += _Np;
796    }
797}
798
799template <class _Alloc, class _Ptr>
800_LIBCPP_INLINE_VISIBILITY
801void __construct_backward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2) {
802    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
803        "The specified type does not meet the requirements of Cpp17MoveInsertable");
804    typedef allocator_traits<_Alloc> _Traits;
805    while (__end1 != __begin1) {
806        _Traits::construct(__a, _VSTD::__to_address(__end2 - 1),
807#ifdef _LIBCPP_NO_EXCEPTIONS
808            _VSTD::move(*--__end1)
809#else
810            _VSTD::move_if_noexcept(*--__end1)
811#endif
812        );
813        --__end2;
814    }
815}
816
817template <class _Alloc, class _Tp, class = typename enable_if<
818    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
819    is_trivially_move_constructible<_Tp>::value
820>::type>
821_LIBCPP_INLINE_VISIBILITY
822void __construct_backward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2) {
823    ptrdiff_t _Np = __end1 - __begin1;
824    __end2 -= _Np;
825    if (_Np > 0)
826        _VSTD::memcpy(static_cast<void*>(__end2), static_cast<void const*>(__begin1), _Np * sizeof(_Tp));
827}
828
829struct __destruct_n
830{
831private:
832    size_t __size_;
833
834    template <class _Tp>
835    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
836        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
837
838    template <class _Tp>
839    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
840        {}
841
842    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
843        {++__size_;}
844    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
845        {}
846
847    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
848        {__size_ = __s;}
849    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
850        {}
851public:
852    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
853        : __size_(__s) {}
854
855    template <class _Tp>
856    _LIBCPP_INLINE_VISIBILITY void __incr() _NOEXCEPT
857        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
858
859    template <class _Tp>
860    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
861        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
862
863    template <class _Tp>
864    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
865        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
866};
867
868_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
869
870// --- Helper for container swap --
871template <typename _Alloc>
872_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
873void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
874#if _LIBCPP_STD_VER > 11
875    _NOEXCEPT
876#else
877    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
878#endif
879{
880    using _VSTD::swap;
881    swap(__a1, __a2);
882}
883
884template <typename _Alloc>
885inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
886void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
887
888template <typename _Alloc>
889inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
890void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
891#if _LIBCPP_STD_VER > 11
892    _NOEXCEPT
893#else
894    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
895#endif
896{
897    _VSTD::__swap_allocator(__a1, __a2,
898      integral_constant<bool, allocator_traits<_Alloc>::propagate_on_container_swap::value>());
899}
900
901template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
902struct __noexcept_move_assign_container : public integral_constant<bool,
903    _Traits::propagate_on_container_move_assignment::value
904#if _LIBCPP_STD_VER > 14
905        || _Traits::is_always_equal::value
906#else
907        && is_nothrow_move_assignable<_Alloc>::value
908#endif
909    > {};
910
911
912template <class _Tp, class _Alloc>
913struct __temp_value {
914    typedef allocator_traits<_Alloc> _Traits;
915
916    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
917    _Alloc &__a;
918
919    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
920    _Tp &   get() { return *__addr(); }
921
922    template<class... _Args>
923    _LIBCPP_NO_CFI
924    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
925      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
926                         _VSTD::forward<_Args>(__args)...);
927    }
928
929    ~__temp_value() { _Traits::destroy(__a, __addr()); }
930    };
931
932template<typename _Alloc, typename = void, typename = void>
933struct __is_allocator : false_type {};
934
935template<typename _Alloc>
936struct __is_allocator<_Alloc,
937       typename __void_t<typename _Alloc::value_type>::type,
938       typename __void_t<decltype(declval<_Alloc&>().allocate(size_t(0)))>::type
939     >
940   : true_type {};
941
942// __builtin_new_allocator -- A non-templated helper for allocating and
943// deallocating memory using __builtin_operator_new and
944// __builtin_operator_delete. It should be used in preference to
945// `std::allocator<T>` to avoid additional instantiations.
946struct __builtin_new_allocator {
947  struct __builtin_new_deleter {
948    typedef void* pointer_type;
949
950    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
951        : __size_(__size), __align_(__align) {}
952
953    void operator()(void* p) const _NOEXCEPT {
954        _VSTD::__libcpp_deallocate(p, __size_, __align_);
955    }
956
957   private:
958    size_t __size_;
959    size_t __align_;
960  };
961
962  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
963
964  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
965      return __holder_t(_VSTD::__libcpp_allocate(__s, __align),
966                     __builtin_new_deleter(__s, __align));
967  }
968
969  static void __deallocate_bytes(void* __p, size_t __s,
970                                 size_t __align) _NOEXCEPT {
971      _VSTD::__libcpp_deallocate(__p, __s, __align);
972  }
973
974  template <class _Tp>
975  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
976  static __holder_t __allocate_type(size_t __n) {
977      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
978  }
979
980  template <class _Tp>
981  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
982  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
983      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
984  }
985};
986
987
988_LIBCPP_END_NAMESPACE_STD
989
990#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
991#   include <__pstl_memory>
992#endif
993
994#endif // _LIBCPP_MEMORY
995