xref: /freebsd/contrib/llvm-project/libcxx/include/memory (revision 8ddb146abcdf061be9f2c0db7e391697dafad85c)
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
184namespace ranges {
185
186template<class InputIterator, class OutputIterator>
187using uninitialized_copy_result = in_out_result<InputIterator, OutputIterator>; // since C++20
188
189template<input_iterator InputIterator, sentinel-for<InputIterator> Sentinel1, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel2>
190  requires constructible_from<iter_value_t<OutputIterator>, iter_reference_t<InputIterator>>
191uninitialized_copy_result<InputIterator, OutputIterator>
192uninitialized_copy(InputIterator ifirst, Sentinel1 ilast, OutputIterator ofirst, Sentinel2 olast); // since C++20
193
194template<input_range InputRange, nothrow-forward-range OutputRange>
195  requires constructible_from<range_value_t<OutputRange>, range_reference_t<InputRange>>
196uninitialized_copy_result<borrowed_iterator_t<InputRange>, borrowed_iterator_t<OutputRange>>
197uninitialized_copy(InputRange&& in_range, OutputRange&& out_range); // since C++20
198
199}
200
201template <class InputIterator, class Size, class ForwardIterator>
202ForwardIterator
203uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
204
205namespace ranges {
206
207template<class InputIterator, class OutputIterator>
208using uninitialized_copy_n_result = in_out_result<InputIterator, OutputIterator>; // since C++20
209
210template<input_iterator InputIterator, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel>
211  requires constructible_from<iter_value_t<OutputIterator>, iter_reference_t<InputIterator>>
212uninitialized_copy_n_result<InputIterator, OutputIterator>
213uninitialized_copy_n(InputIterator ifirst, iter_difference_t<InputIterator> n, OutputIterator ofirst, Sentinel olast); // since C++20
214
215}
216
217template <class ForwardIterator, class T>
218void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
219
220namespace ranges {
221
222template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel, class T>
223  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
224ForwardIterator uninitialized_fill(ForwardIterator first, Sentinel last, const T& x); // since C++20
225
226template <nothrow-forward-range ForwardRange, class T>
227  requires constructible_from<range_value_t<ForwardRange>, const T&>
228borrowed_iterator_t<ForwardRange> uninitialized_fill(ForwardRange&& range, const T& x); // since C++20
229
230}
231
232template <class ForwardIterator, class Size, class T>
233ForwardIterator
234uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
235
236namespace ranges {
237
238template <nothrow-forward-iterator ForwardIterator, class T>
239  requires constructible_from<iter_value_t<ForwardIterator>, const T&>
240ForwardIterator uninitialized_fill_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
241
242}
243
244template <class T, class ...Args>
245constexpr T* construct_at(T* location, Args&& ...args); // since C++20
246
247namespace ranges {
248  template<class T, class... Args>
249    constexpr T* construct_at(T* location, Args&&... args); // since C++20
250}
251
252template <class T>
253void destroy_at(T* location); // constexpr in C++20
254
255namespace ranges {
256  template<destructible T>
257    constexpr void destroy_at(T* location) noexcept; // since C++20
258}
259
260template <class ForwardIterator>
261void destroy(ForwardIterator first, ForwardIterator last); // constexpr in C++20
262
263namespace ranges {
264  template<nothrow-input-iterator InputIterator, nothrow-sentinel-for<InputIterator> Sentinel>
265    requires destructible<iter_value_t<InputIterator>>
266    constexpr InputIterator destroy(InputIterator first, Sentinel last) noexcept; // since C++20
267  template<nothrow-input-range InputRange>
268    requires destructible<range_value_t<InputRange>>
269    constexpr borrowed_iterator_t<InputRange> destroy(InputRange&& range) noexcept; // since C++20
270}
271
272template <class ForwardIterator, class Size>
273ForwardIterator destroy_n(ForwardIterator first, Size n); // constexpr in C++20
274
275namespace ranges {
276  template<nothrow-input-iterator InputIterator>
277    requires destructible<iter_value_t<InputIterator>>
278    constexpr InputIterator destroy_n(InputIterator first, iter_difference_t<InputIterator> n) noexcept; // since C++20
279}
280
281template <class InputIterator, class ForwardIterator>
282 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
283
284namespace ranges {
285
286template<class InputIterator, class OutputIterator>
287using uninitialized_move_result = in_out_result<InputIterator, OutputIterator>; // since C++20
288
289template <input_iterator InputIterator, sentinel_for<InputIterator> Sentinel1, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<O> Sentinel2>
290  requires constructible_from<iter_value_t<OutputIterator>, iter_rvalue_reference_t<InputIterator>>
291uninitialized_move_result<InputIterator, OutputIterator>
292uninitialized_move(InputIterator ifirst, Sentinel1 ilast, OutputIterator ofirst, Sentinel2 olast); // since C++20
293
294template<input_range InputRange, nothrow-forward-range OutputRange>
295  requires constructible_from<range_value_t<OutputRange>, range_rvalue_reference_t<InputRange>>
296uninitialized_move_result<borrowed_iterator_t<InputRange>, borrowed_iterator_t<OutputRange>>
297uninitialized_move(InputRange&& in_range, OutputRange&& out_range); // since C++20
298
299}
300
301template <class InputIterator, class Size, class ForwardIterator>
302 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
303
304namespace ranges {
305
306template<class InputIterator, class OutputIterator>
307using uninitialized_move_n_result = in_out_result<InputIterator, OutputIterator>; // since C++20
308
309template<input_iterator InputIterator, nothrow-forward-iterator OutputIterator, nothrow-sentinel-for<OutputIterator> Sentinel>
310  requires constructible_from<iter_value_t<OutputIterator>, iter_rvalue_reference_t<InputIterator>>
311uninitialized_move_n_result<InputIterator, OutputIterator>
312uninitialized_move_n(InputIterator ifirst, iter_difference_t<InputIterator> n, OutputIterator ofirst, Sentinel olast); // since C++20
313
314}
315
316template <class ForwardIterator>
317 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
318
319namespace ranges {
320
321template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
322  requires default_initializable<iter_value_t<ForwardIterator>>
323 ForwardIterator uninitialized_value_construct(ForwardIterator first, Sentinel last); // since C++20
324
325template <nothrow-forward-range ForwardRange>
326  requires default_initializable<range_value_t<ForwardRange>>
327 borrowed_iterator_t<ForwardRange> uninitialized_value_construct(ForwardRange&& r); // since C++20
328
329}
330
331template <class ForwardIterator, class Size>
332 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
333
334namespace ranges {
335
336template <nothrow-forward-iterator ForwardIterator>
337  requires default_initializable<iter_value_t<ForwardIterator>>
338 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
339
340}
341
342template <class ForwardIterator>
343 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
344
345namespace ranges {
346
347template <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
348  requires default_initializable<iter_value_t<ForwardIterator>>
349 ForwardIterator uninitialized_default_construct(ForwardIterator first, Sentinel last); // since C++20
350
351template <nothrow-forward-range ForwardRange>
352  requires default_initializable<range_value_t<ForwardRange>>
353 borrowed_iterator_t<ForwardRange> uninitialized_default_construct(ForwardRange&& r); // since C++20
354
355}
356
357template <class ForwardIterator, class Size>
358 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
359
360namespace ranges {
361
362template <nothrow-forward-iterator ForwardIterator>
363  requires default_initializable<iter_value_t<ForwardIterator>>
364 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
365
366}
367
368template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
369
370template<class X>
371class auto_ptr                                  // deprecated in C++11, removed in C++17
372{
373public:
374    typedef X element_type;
375
376    explicit auto_ptr(X* p =0) throw();
377    auto_ptr(auto_ptr&) throw();
378    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
379    auto_ptr& operator=(auto_ptr&) throw();
380    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
381    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
382    ~auto_ptr() throw();
383
384    typename add_lvalue_reference<X>::type operator*() const throw();
385    X* operator->() const throw();
386    X* get() const throw();
387    X* release() throw();
388    void reset(X* p =0) throw();
389
390    auto_ptr(auto_ptr_ref<X>) throw();
391    template<class Y> operator auto_ptr_ref<Y>() throw();
392    template<class Y> operator auto_ptr<Y>() throw();
393};
394
395template <class T>
396struct default_delete
397{
398    constexpr default_delete() noexcept = default;
399    template <class U> default_delete(const default_delete<U>&) noexcept;
400
401    void operator()(T*) const noexcept;
402};
403
404template <class T>
405struct default_delete<T[]>
406{
407    constexpr default_delete() noexcept = default;
408    void operator()(T*) const noexcept;
409    template <class U> void operator()(U*) const = delete;
410};
411
412template <class T, class D = default_delete<T>>
413class unique_ptr
414{
415public:
416    typedef see below pointer;
417    typedef T element_type;
418    typedef D deleter_type;
419
420    // constructors
421    constexpr unique_ptr() noexcept;
422    explicit unique_ptr(pointer p) noexcept;
423    unique_ptr(pointer p, see below d1) noexcept;
424    unique_ptr(pointer p, see below d2) noexcept;
425    unique_ptr(unique_ptr&& u) noexcept;
426    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
427    template <class U, class E>
428        unique_ptr(unique_ptr<U, E>&& u) noexcept;
429    template <class U>
430        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
431
432    // destructor
433    ~unique_ptr();
434
435    // assignment
436    unique_ptr& operator=(unique_ptr&& u) noexcept;
437    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
438    unique_ptr& operator=(nullptr_t) noexcept;
439
440    // observers
441    typename add_lvalue_reference<T>::type operator*() const;
442    pointer operator->() const noexcept;
443    pointer get() const noexcept;
444    deleter_type& get_deleter() noexcept;
445    const deleter_type& get_deleter() const noexcept;
446    explicit operator bool() const noexcept;
447
448    // modifiers
449    pointer release() noexcept;
450    void reset(pointer p = pointer()) noexcept;
451    void swap(unique_ptr& u) noexcept;
452};
453
454template <class T, class D>
455class unique_ptr<T[], D>
456{
457public:
458    typedef implementation-defined pointer;
459    typedef T element_type;
460    typedef D deleter_type;
461
462    // constructors
463    constexpr unique_ptr() noexcept;
464    explicit unique_ptr(pointer p) noexcept;
465    unique_ptr(pointer p, see below d) noexcept;
466    unique_ptr(pointer p, see below d) noexcept;
467    unique_ptr(unique_ptr&& u) noexcept;
468    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
469
470    // destructor
471    ~unique_ptr();
472
473    // assignment
474    unique_ptr& operator=(unique_ptr&& u) noexcept;
475    unique_ptr& operator=(nullptr_t) noexcept;
476
477    // observers
478    T& operator[](size_t i) const;
479    pointer get() const noexcept;
480    deleter_type& get_deleter() noexcept;
481    const deleter_type& get_deleter() const noexcept;
482    explicit operator bool() const noexcept;
483
484    // modifiers
485    pointer release() noexcept;
486    void reset(pointer p = pointer()) noexcept;
487    void reset(nullptr_t) noexcept;
488  template <class U> void reset(U) = delete;
489    void swap(unique_ptr& u) noexcept;
490};
491
492template <class T, class D>
493    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
494
495template <class T1, class D1, class T2, class D2>
496    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
497template <class T1, class D1, class T2, class D2>
498    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
499template <class T1, class D1, class T2, class D2>
500    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
501template <class T1, class D1, class T2, class D2>
502    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
503template <class T1, class D1, class T2, class D2>
504    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
505template <class T1, class D1, class T2, class D2>
506    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
507
508template <class T, class D>
509    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
510template <class T, class D>
511    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
512template <class T, class D>
513    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
514template <class T, class D>
515    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
516
517template <class T, class D>
518    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
519template <class T, class D>
520    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
521template <class T, class D>
522    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
523template <class T, class D>
524    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
525template <class T, class D>
526    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
527template <class T, class D>
528    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
529template <class T, class D>
530    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
531template <class T, class D>
532    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
533
534class bad_weak_ptr
535    : public std::exception
536{
537    bad_weak_ptr() noexcept;
538};
539
540template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
541template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
542template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
543
544template<class E, class T, class Y, class D>
545    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
546
547template<class T>
548class shared_ptr
549{
550public:
551    typedef T element_type; // until C++17
552    typedef remove_extent_t<T> element_type; // since C++17
553    typedef weak_ptr<T> weak_type; // C++17
554
555    // constructors:
556    constexpr shared_ptr() noexcept;
557    template<class Y> explicit shared_ptr(Y* p);
558    template<class Y, class D> shared_ptr(Y* p, D d);
559    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
560    template <class D> shared_ptr(nullptr_t p, D d);
561    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
562    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
563    shared_ptr(const shared_ptr& r) noexcept;
564    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
565    shared_ptr(shared_ptr&& r) noexcept;
566    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
567    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
568    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
569    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
570    shared_ptr(nullptr_t) : shared_ptr() { }
571
572    // destructor:
573    ~shared_ptr();
574
575    // assignment:
576    shared_ptr& operator=(const shared_ptr& r) noexcept;
577    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
578    shared_ptr& operator=(shared_ptr&& r) noexcept;
579    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
580    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
581    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
582
583    // modifiers:
584    void swap(shared_ptr& r) noexcept;
585    void reset() noexcept;
586    template<class Y> void reset(Y* p);
587    template<class Y, class D> void reset(Y* p, D d);
588    template<class Y, class D, class A> void reset(Y* p, D d, A a);
589
590    // observers:
591    T* get() const noexcept;
592    T& operator*() const noexcept;
593    T* operator->() const noexcept;
594    long use_count() const noexcept;
595    bool unique() const noexcept;
596    explicit operator bool() const noexcept;
597    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
598    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
599};
600
601template<class T>
602shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
603template<class T, class D>
604shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
605
606// shared_ptr comparisons:
607template<class T, class U>
608    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
609template<class T, class U>
610    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
611template<class T, class U>
612    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
613template<class T, class U>
614    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
615template<class T, class U>
616    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
617template<class T, class U>
618    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
619
620template <class T>
621    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
622template <class T>
623    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
624template <class T>
625    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
626template <class T>
627    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
628template <class T>
629    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
630template <class T>
631bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
632template <class T>
633    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
634template <class T>
635    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
636template <class T>
637    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
638template <class T>
639    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
640template <class T>
641    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
642template <class T>
643    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
644
645// shared_ptr specialized algorithms:
646template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
647
648// shared_ptr casts:
649template<class T, class U>
650    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
651template<class T, class U>
652    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
653template<class T, class U>
654    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
655
656// shared_ptr I/O:
657template<class E, class T, class Y>
658    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
659
660// shared_ptr get_deleter:
661template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
662
663template<class T, class... Args>
664    shared_ptr<T> make_shared(Args&&... args);
665template<class T, class A, class... Args>
666    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
667
668template<class T>
669class weak_ptr
670{
671public:
672    typedef T element_type; // until C++17
673    typedef remove_extent_t<T> element_type; // since C++17
674
675    // constructors
676    constexpr weak_ptr() noexcept;
677    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
678    weak_ptr(weak_ptr const& r) noexcept;
679    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
680    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
681    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
682
683    // destructor
684    ~weak_ptr();
685
686    // assignment
687    weak_ptr& operator=(weak_ptr const& r) noexcept;
688    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
689    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
690    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
691    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
692
693    // modifiers
694    void swap(weak_ptr& r) noexcept;
695    void reset() noexcept;
696
697    // observers
698    long use_count() const noexcept;
699    bool expired() const noexcept;
700    shared_ptr<T> lock() const noexcept;
701    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
702    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
703};
704
705template<class T>
706weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
707
708// weak_ptr specialized algorithms:
709template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
710
711// class owner_less:
712template<class T> struct owner_less;
713
714template<class T>
715struct owner_less<shared_ptr<T> >
716    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
717{
718    typedef bool result_type;
719    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
720    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
721    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
722};
723
724template<class T>
725struct owner_less<weak_ptr<T> >
726    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
727{
728    typedef bool result_type;
729    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
730    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
731    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
732};
733
734template <>  // Added in C++14
735struct owner_less<void>
736{
737    template <class _Tp, class _Up>
738    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
739    template <class _Tp, class _Up>
740    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
741    template <class _Tp, class _Up>
742    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
743    template <class _Tp, class _Up>
744    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
745
746    typedef void is_transparent;
747};
748
749template<class T>
750class enable_shared_from_this
751{
752protected:
753    constexpr enable_shared_from_this() noexcept;
754    enable_shared_from_this(enable_shared_from_this const&) noexcept;
755    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
756    ~enable_shared_from_this();
757public:
758    shared_ptr<T> shared_from_this();
759    shared_ptr<T const> shared_from_this() const;
760};
761
762template<class T>
763    bool atomic_is_lock_free(const shared_ptr<T>* p);
764template<class T>
765    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
766template<class T>
767    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
768template<class T>
769    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
770template<class T>
771    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
772template<class T>
773    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
774template<class T>
775    shared_ptr<T>
776    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
777template<class T>
778    bool
779    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
780template<class T>
781    bool
782    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
783template<class T>
784    bool
785    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
786                                          shared_ptr<T> w, memory_order success,
787                                          memory_order failure);
788template<class T>
789    bool
790    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
791                                            shared_ptr<T> w, memory_order success,
792                                            memory_order failure);
793// Hash support
794template <class T> struct hash;
795template <class T, class D> struct hash<unique_ptr<T, D> >;
796template <class T> struct hash<shared_ptr<T> >;
797
798template <class T, class Alloc>
799  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
800
801void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
802
803}  // std
804
805*/
806
807#include <__config>
808#include <__functional_base>
809#include <__memory/addressof.h>
810#include <__memory/allocation_guard.h>
811#include <__memory/allocator.h>
812#include <__memory/allocator_arg_t.h>
813#include <__memory/allocator_traits.h>
814#include <__memory/compressed_pair.h>
815#include <__memory/concepts.h>
816#include <__memory/construct_at.h>
817#include <__memory/pointer_traits.h>
818#include <__memory/ranges_construct_at.h>
819#include <__memory/ranges_uninitialized_algorithms.h>
820#include <__memory/raw_storage_iterator.h>
821#include <__memory/shared_ptr.h>
822#include <__memory/temporary_buffer.h>
823#include <__memory/uninitialized_algorithms.h>
824#include <__memory/unique_ptr.h>
825#include <__memory/uses_allocator.h>
826#include <compare>
827#include <cstddef>
828#include <cstdint>
829#include <cstring>
830#include <iosfwd>
831#include <iterator>
832#include <new>
833#include <stdexcept>
834#include <tuple>
835#include <type_traits>
836#include <typeinfo>
837#include <utility>
838#include <version>
839
840#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
841#   include <__memory/auto_ptr.h>
842#endif
843
844#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
845#pragma GCC system_header
846#endif
847
848_LIBCPP_BEGIN_NAMESPACE_STD
849
850template <class _Alloc, class _Ptr>
851_LIBCPP_INLINE_VISIBILITY
852void __construct_forward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2) {
853    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
854        "The specified type does not meet the requirements of Cpp17MoveInsertable");
855    typedef allocator_traits<_Alloc> _Traits;
856    for (; __begin1 != __end1; ++__begin1, (void)++__begin2) {
857        _Traits::construct(__a, _VSTD::__to_address(__begin2),
858#ifdef _LIBCPP_NO_EXCEPTIONS
859            _VSTD::move(*__begin1)
860#else
861            _VSTD::move_if_noexcept(*__begin1)
862#endif
863        );
864    }
865}
866
867template <class _Alloc, class _Tp, typename enable_if<
868    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
869    is_trivially_move_constructible<_Tp>::value
870>::type>
871_LIBCPP_INLINE_VISIBILITY
872void __construct_forward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2) {
873    ptrdiff_t _Np = __end1 - __begin1;
874    if (_Np > 0) {
875        _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
876        __begin2 += _Np;
877    }
878}
879
880template <class _Alloc, class _Iter, class _Ptr>
881_LIBCPP_INLINE_VISIBILITY
882void __construct_range_forward(_Alloc& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2) {
883    typedef allocator_traits<_Alloc> _Traits;
884    for (; __begin1 != __end1; ++__begin1, (void) ++__begin2) {
885        _Traits::construct(__a, _VSTD::__to_address(__begin2), *__begin1);
886    }
887}
888
889template <class _Alloc, class _Source, class _Dest,
890          class _RawSource = typename remove_const<_Source>::type,
891          class _RawDest = typename remove_const<_Dest>::type,
892          class =
893    typename enable_if<
894        is_trivially_copy_constructible<_Dest>::value &&
895        is_same<_RawSource, _RawDest>::value &&
896        (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Dest*, _Source&>::value)
897    >::type>
898_LIBCPP_INLINE_VISIBILITY
899void __construct_range_forward(_Alloc&, _Source* __begin1, _Source* __end1, _Dest*& __begin2) {
900    ptrdiff_t _Np = __end1 - __begin1;
901    if (_Np > 0) {
902        _VSTD::memcpy(const_cast<_RawDest*>(__begin2), __begin1, _Np * sizeof(_Dest));
903        __begin2 += _Np;
904    }
905}
906
907template <class _Alloc, class _Ptr>
908_LIBCPP_INLINE_VISIBILITY
909void __construct_backward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2) {
910    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
911        "The specified type does not meet the requirements of Cpp17MoveInsertable");
912    typedef allocator_traits<_Alloc> _Traits;
913    while (__end1 != __begin1) {
914        _Traits::construct(__a, _VSTD::__to_address(__end2 - 1),
915#ifdef _LIBCPP_NO_EXCEPTIONS
916            _VSTD::move(*--__end1)
917#else
918            _VSTD::move_if_noexcept(*--__end1)
919#endif
920        );
921        --__end2;
922    }
923}
924
925template <class _Alloc, class _Tp, class = typename enable_if<
926    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
927    is_trivially_move_constructible<_Tp>::value
928>::type>
929_LIBCPP_INLINE_VISIBILITY
930void __construct_backward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2) {
931    ptrdiff_t _Np = __end1 - __begin1;
932    __end2 -= _Np;
933    if (_Np > 0)
934        _VSTD::memcpy(static_cast<void*>(__end2), static_cast<void const*>(__begin1), _Np * sizeof(_Tp));
935}
936
937struct __destruct_n
938{
939private:
940    size_t __size_;
941
942    template <class _Tp>
943    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
944        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
945
946    template <class _Tp>
947    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
948        {}
949
950    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
951        {++__size_;}
952    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
953        {}
954
955    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
956        {__size_ = __s;}
957    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
958        {}
959public:
960    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
961        : __size_(__s) {}
962
963    template <class _Tp>
964    _LIBCPP_INLINE_VISIBILITY void __incr() _NOEXCEPT
965        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
966
967    template <class _Tp>
968    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
969        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
970
971    template <class _Tp>
972    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
973        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
974};
975
976_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
977
978// --- Helper for container swap --
979template <typename _Alloc>
980_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
981void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
982#if _LIBCPP_STD_VER > 11
983    _NOEXCEPT
984#else
985    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
986#endif
987{
988    using _VSTD::swap;
989    swap(__a1, __a2);
990}
991
992template <typename _Alloc>
993inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
994void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
995
996template <typename _Alloc>
997inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
998void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
999#if _LIBCPP_STD_VER > 11
1000    _NOEXCEPT
1001#else
1002    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
1003#endif
1004{
1005    _VSTD::__swap_allocator(__a1, __a2,
1006      integral_constant<bool, allocator_traits<_Alloc>::propagate_on_container_swap::value>());
1007}
1008
1009template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
1010struct __noexcept_move_assign_container : public integral_constant<bool,
1011    _Traits::propagate_on_container_move_assignment::value
1012#if _LIBCPP_STD_VER > 14
1013        || _Traits::is_always_equal::value
1014#else
1015        && is_nothrow_move_assignable<_Alloc>::value
1016#endif
1017    > {};
1018
1019
1020template <class _Tp, class _Alloc>
1021struct __temp_value {
1022    typedef allocator_traits<_Alloc> _Traits;
1023
1024    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
1025    _Alloc &__a;
1026
1027    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
1028    _Tp &   get() { return *__addr(); }
1029
1030    template<class... _Args>
1031    _LIBCPP_NO_CFI
1032    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
1033      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
1034                         _VSTD::forward<_Args>(__args)...);
1035    }
1036
1037    ~__temp_value() { _Traits::destroy(__a, __addr()); }
1038    };
1039
1040template<typename _Alloc, typename = void, typename = void>
1041struct __is_allocator : false_type {};
1042
1043template<typename _Alloc>
1044struct __is_allocator<_Alloc,
1045       typename __void_t<typename _Alloc::value_type>::type,
1046       typename __void_t<decltype(declval<_Alloc&>().allocate(size_t(0)))>::type
1047     >
1048   : true_type {};
1049
1050// __builtin_new_allocator -- A non-templated helper for allocating and
1051// deallocating memory using __builtin_operator_new and
1052// __builtin_operator_delete. It should be used in preference to
1053// `std::allocator<T>` to avoid additional instantiations.
1054struct __builtin_new_allocator {
1055  struct __builtin_new_deleter {
1056    typedef void* pointer_type;
1057
1058    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
1059        : __size_(__size), __align_(__align) {}
1060
1061    void operator()(void* p) const _NOEXCEPT {
1062        _VSTD::__libcpp_deallocate(p, __size_, __align_);
1063    }
1064
1065   private:
1066    size_t __size_;
1067    size_t __align_;
1068  };
1069
1070  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
1071
1072  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
1073      return __holder_t(_VSTD::__libcpp_allocate(__s, __align),
1074                     __builtin_new_deleter(__s, __align));
1075  }
1076
1077  static void __deallocate_bytes(void* __p, size_t __s,
1078                                 size_t __align) _NOEXCEPT {
1079      _VSTD::__libcpp_deallocate(__p, __s, __align);
1080  }
1081
1082  template <class _Tp>
1083  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
1084  static __holder_t __allocate_type(size_t __n) {
1085      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
1086  }
1087
1088  template <class _Tp>
1089  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
1090  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
1091      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
1092  }
1093};
1094
1095
1096_LIBCPP_END_NAMESPACE_STD
1097
1098#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
1099#   include <__pstl_memory>
1100#endif
1101
1102#endif // _LIBCPP_MEMORY
1103