xref: /freebsd/contrib/llvm-project/libcxx/include/memory (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
1// -*- C++ -*-
2//===-------------------------- memory ------------------------------------===//
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 <class ForwardIterator, class Size, class T>
192ForwardIterator
193uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
194
195template <class T, class ...Args>
196constexpr T* construct_at(T* location, Args&& ...args); // since C++20
197
198template <class T>
199void destroy_at(T* location); // constexpr in C++20
200
201template <class ForwardIterator>
202void destroy(ForwardIterator first, ForwardIterator last); // constexpr in C++20
203
204template <class ForwardIterator, class Size>
205ForwardIterator destroy_n(ForwardIterator first, Size n); // constexpr in C++20
206
207template <class InputIterator, class ForwardIterator>
208 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
209
210template <class InputIterator, class Size, class ForwardIterator>
211 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
212
213template <class ForwardIterator>
214 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
215
216template <class ForwardIterator, class Size>
217 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
218
219template <class ForwardIterator>
220 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
221
222template <class ForwardIterator, class Size>
223 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
224
225template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
226
227template<class X>
228class auto_ptr                                  // deprecated in C++11, removed in C++17
229{
230public:
231    typedef X element_type;
232
233    explicit auto_ptr(X* p =0) throw();
234    auto_ptr(auto_ptr&) throw();
235    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
236    auto_ptr& operator=(auto_ptr&) throw();
237    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
238    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
239    ~auto_ptr() throw();
240
241    typename add_lvalue_reference<X>::type operator*() const throw();
242    X* operator->() const throw();
243    X* get() const throw();
244    X* release() throw();
245    void reset(X* p =0) throw();
246
247    auto_ptr(auto_ptr_ref<X>) throw();
248    template<class Y> operator auto_ptr_ref<Y>() throw();
249    template<class Y> operator auto_ptr<Y>() throw();
250};
251
252template <class T>
253struct default_delete
254{
255    constexpr default_delete() noexcept = default;
256    template <class U> default_delete(const default_delete<U>&) noexcept;
257
258    void operator()(T*) const noexcept;
259};
260
261template <class T>
262struct default_delete<T[]>
263{
264    constexpr default_delete() noexcept = default;
265    void operator()(T*) const noexcept;
266    template <class U> void operator()(U*) const = delete;
267};
268
269template <class T, class D = default_delete<T>>
270class unique_ptr
271{
272public:
273    typedef see below pointer;
274    typedef T element_type;
275    typedef D deleter_type;
276
277    // constructors
278    constexpr unique_ptr() noexcept;
279    explicit unique_ptr(pointer p) noexcept;
280    unique_ptr(pointer p, see below d1) noexcept;
281    unique_ptr(pointer p, see below d2) noexcept;
282    unique_ptr(unique_ptr&& u) noexcept;
283    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
284    template <class U, class E>
285        unique_ptr(unique_ptr<U, E>&& u) noexcept;
286    template <class U>
287        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
288
289    // destructor
290    ~unique_ptr();
291
292    // assignment
293    unique_ptr& operator=(unique_ptr&& u) noexcept;
294    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
295    unique_ptr& operator=(nullptr_t) noexcept;
296
297    // observers
298    typename add_lvalue_reference<T>::type operator*() const;
299    pointer operator->() const noexcept;
300    pointer get() const noexcept;
301    deleter_type& get_deleter() noexcept;
302    const deleter_type& get_deleter() const noexcept;
303    explicit operator bool() const noexcept;
304
305    // modifiers
306    pointer release() noexcept;
307    void reset(pointer p = pointer()) noexcept;
308    void swap(unique_ptr& u) noexcept;
309};
310
311template <class T, class D>
312class unique_ptr<T[], D>
313{
314public:
315    typedef implementation-defined pointer;
316    typedef T element_type;
317    typedef D deleter_type;
318
319    // constructors
320    constexpr unique_ptr() noexcept;
321    explicit unique_ptr(pointer p) noexcept;
322    unique_ptr(pointer p, see below d) noexcept;
323    unique_ptr(pointer p, see below d) noexcept;
324    unique_ptr(unique_ptr&& u) noexcept;
325    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
326
327    // destructor
328    ~unique_ptr();
329
330    // assignment
331    unique_ptr& operator=(unique_ptr&& u) noexcept;
332    unique_ptr& operator=(nullptr_t) noexcept;
333
334    // observers
335    T& operator[](size_t i) const;
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 reset(nullptr_t) noexcept;
345  template <class U> void reset(U) = delete;
346    void swap(unique_ptr& u) noexcept;
347};
348
349template <class T, class D>
350    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
351
352template <class T1, class D1, class T2, class D2>
353    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
354template <class T1, class D1, class T2, class D2>
355    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
356template <class T1, class D1, class T2, class D2>
357    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
358template <class T1, class D1, class T2, class D2>
359    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
360template <class T1, class D1, class T2, class D2>
361    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
362template <class T1, class D1, class T2, class D2>
363    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
364
365template <class T, class D>
366    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
367template <class T, class D>
368    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
369template <class T, class D>
370    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
371template <class T, class D>
372    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
373
374template <class T, class D>
375    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
376template <class T, class D>
377    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
378template <class T, class D>
379    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
380template <class T, class D>
381    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
382template <class T, class D>
383    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
384template <class T, class D>
385    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
386template <class T, class D>
387    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
388template <class T, class D>
389    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
390
391class bad_weak_ptr
392    : public std::exception
393{
394    bad_weak_ptr() noexcept;
395};
396
397template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
398template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
399template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
400
401template<class E, class T, class Y, class D>
402    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
403
404template<class T>
405class shared_ptr
406{
407public:
408    typedef T element_type;
409    typedef weak_ptr<T> weak_type; // C++17
410
411    // constructors:
412    constexpr shared_ptr() noexcept;
413    template<class Y> explicit shared_ptr(Y* p);
414    template<class Y, class D> shared_ptr(Y* p, D d);
415    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
416    template <class D> shared_ptr(nullptr_t p, D d);
417    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
418    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
419    shared_ptr(const shared_ptr& r) noexcept;
420    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
421    shared_ptr(shared_ptr&& r) noexcept;
422    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
423    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
424    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
425    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
426    shared_ptr(nullptr_t) : shared_ptr() { }
427
428    // destructor:
429    ~shared_ptr();
430
431    // assignment:
432    shared_ptr& operator=(const shared_ptr& r) noexcept;
433    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
434    shared_ptr& operator=(shared_ptr&& r) noexcept;
435    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
436    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
437    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
438
439    // modifiers:
440    void swap(shared_ptr& r) noexcept;
441    void reset() noexcept;
442    template<class Y> void reset(Y* p);
443    template<class Y, class D> void reset(Y* p, D d);
444    template<class Y, class D, class A> void reset(Y* p, D d, A a);
445
446    // observers:
447    T* get() const noexcept;
448    T& operator*() const noexcept;
449    T* operator->() const noexcept;
450    long use_count() const noexcept;
451    bool unique() const noexcept;
452    explicit operator bool() const noexcept;
453    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
454    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
455};
456
457template<class T>
458shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
459template<class T, class D>
460shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
461
462// shared_ptr comparisons:
463template<class T, class U>
464    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
465template<class T, class U>
466    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
467template<class T, class U>
468    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
469template<class T, class U>
470    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
471template<class T, class U>
472    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
473template<class T, class U>
474    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
475
476template <class T>
477    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
478template <class T>
479    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
480template <class T>
481    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
482template <class T>
483    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
484template <class T>
485    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
486template <class T>
487bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
488template <class T>
489    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
490template <class T>
491    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
492template <class T>
493    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
494template <class T>
495    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
496template <class T>
497    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
498template <class T>
499    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
500
501// shared_ptr specialized algorithms:
502template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
503
504// shared_ptr casts:
505template<class T, class U>
506    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
507template<class T, class U>
508    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
509template<class T, class U>
510    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
511
512// shared_ptr I/O:
513template<class E, class T, class Y>
514    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
515
516// shared_ptr get_deleter:
517template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
518
519template<class T, class... Args>
520    shared_ptr<T> make_shared(Args&&... args);
521template<class T, class A, class... Args>
522    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
523
524template<class T>
525class weak_ptr
526{
527public:
528    typedef T element_type;
529
530    // constructors
531    constexpr weak_ptr() noexcept;
532    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
533    weak_ptr(weak_ptr const& r) noexcept;
534    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
535    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
536    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
537
538    // destructor
539    ~weak_ptr();
540
541    // assignment
542    weak_ptr& operator=(weak_ptr const& r) noexcept;
543    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
544    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
545    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
546    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
547
548    // modifiers
549    void swap(weak_ptr& r) noexcept;
550    void reset() noexcept;
551
552    // observers
553    long use_count() const noexcept;
554    bool expired() const noexcept;
555    shared_ptr<T> lock() const noexcept;
556    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
557    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
558};
559
560template<class T>
561weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
562
563// weak_ptr specialized algorithms:
564template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
565
566// class owner_less:
567template<class T> struct owner_less;
568
569template<class T>
570struct owner_less<shared_ptr<T> >
571    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
572{
573    typedef bool result_type;
574    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
575    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
576    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
577};
578
579template<class T>
580struct owner_less<weak_ptr<T> >
581    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
582{
583    typedef bool result_type;
584    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
585    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
586    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
587};
588
589template <>  // Added in C++14
590struct owner_less<void>
591{
592    template <class _Tp, class _Up>
593    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
594    template <class _Tp, class _Up>
595    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
596    template <class _Tp, class _Up>
597    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
598    template <class _Tp, class _Up>
599    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
600
601    typedef void is_transparent;
602};
603
604template<class T>
605class enable_shared_from_this
606{
607protected:
608    constexpr enable_shared_from_this() noexcept;
609    enable_shared_from_this(enable_shared_from_this const&) noexcept;
610    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
611    ~enable_shared_from_this();
612public:
613    shared_ptr<T> shared_from_this();
614    shared_ptr<T const> shared_from_this() const;
615};
616
617template<class T>
618    bool atomic_is_lock_free(const shared_ptr<T>* p);
619template<class T>
620    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
621template<class T>
622    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
623template<class T>
624    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
625template<class T>
626    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
627template<class T>
628    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
629template<class T>
630    shared_ptr<T>
631    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
632template<class T>
633    bool
634    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
635template<class T>
636    bool
637    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
638template<class T>
639    bool
640    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
641                                          shared_ptr<T> w, memory_order success,
642                                          memory_order failure);
643template<class T>
644    bool
645    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
646                                            shared_ptr<T> w, memory_order success,
647                                            memory_order failure);
648// Hash support
649template <class T> struct hash;
650template <class T, class D> struct hash<unique_ptr<T, D> >;
651template <class T> struct hash<shared_ptr<T> >;
652
653template <class T, class Alloc>
654  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
655
656// Pointer safety
657enum class pointer_safety { relaxed, preferred, strict }; // since C++11
658void declare_reachable(void *p);                          // since C++11
659template <class T> T *undeclare_reachable(T *p);          // since C++11
660void declare_no_pointers(char *p, size_t n);              // since C++11
661void undeclare_no_pointers(char *p, size_t n);            // since C++11
662pointer_safety get_pointer_safety() noexcept;             // since C++11
663
664void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
665
666}  // std
667
668*/
669
670#include <__config>
671#include <__functional_base>
672#include <__memory/addressof.h>
673#include <__memory/allocation_guard.h>
674#include <__memory/allocator.h>
675#include <__memory/allocator_arg_t.h>
676#include <__memory/allocator_traits.h>
677#include <__memory/compressed_pair.h>
678#include <__memory/construct_at.h>
679#include <__memory/pointer_safety.h>
680#include <__memory/pointer_traits.h>
681#include <__memory/raw_storage_iterator.h>
682#include <__memory/shared_ptr.h>
683#include <__memory/temporary_buffer.h>
684#include <__memory/uninitialized_algorithms.h>
685#include <__memory/unique_ptr.h>
686#include <__memory/uses_allocator.h>
687#include <compare>
688#include <cstddef>
689#include <cstdint>
690#include <cstring>
691#include <iosfwd>
692#include <iterator>
693#include <new>
694#include <stdexcept>
695#include <tuple>
696#include <type_traits>
697#include <typeinfo>
698#include <utility>
699#include <version>
700
701#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
702#   include <__memory/auto_ptr.h>
703#endif
704
705#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
706#pragma GCC system_header
707#endif
708
709_LIBCPP_PUSH_MACROS
710#include <__undef_macros>
711
712
713_LIBCPP_BEGIN_NAMESPACE_STD
714
715template <class _Alloc, class _Ptr>
716_LIBCPP_INLINE_VISIBILITY
717void __construct_forward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2) {
718    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
719        "The specified type does not meet the requirements of Cpp17MoveInsertable");
720    typedef allocator_traits<_Alloc> _Traits;
721    for (; __begin1 != __end1; ++__begin1, (void)++__begin2) {
722        _Traits::construct(__a, _VSTD::__to_address(__begin2),
723#ifdef _LIBCPP_NO_EXCEPTIONS
724            _VSTD::move(*__begin1)
725#else
726            _VSTD::move_if_noexcept(*__begin1)
727#endif
728        );
729    }
730}
731
732template <class _Alloc, class _Tp, typename enable_if<
733    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
734    is_trivially_move_constructible<_Tp>::value
735>::type>
736_LIBCPP_INLINE_VISIBILITY
737void __construct_forward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2) {
738    ptrdiff_t _Np = __end1 - __begin1;
739    if (_Np > 0) {
740        _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
741        __begin2 += _Np;
742    }
743}
744
745template <class _Alloc, class _Iter, class _Ptr>
746_LIBCPP_INLINE_VISIBILITY
747void __construct_range_forward(_Alloc& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2) {
748    typedef allocator_traits<_Alloc> _Traits;
749    for (; __begin1 != __end1; ++__begin1, (void) ++__begin2) {
750        _Traits::construct(__a, _VSTD::__to_address(__begin2), *__begin1);
751    }
752}
753
754template <class _Alloc, class _Source, class _Dest,
755          class _RawSource = typename remove_const<_Source>::type,
756          class _RawDest = typename remove_const<_Dest>::type,
757          class =
758    typename enable_if<
759        is_trivially_copy_constructible<_Dest>::value &&
760        is_same<_RawSource, _RawDest>::value &&
761        (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Dest*, _Source&>::value)
762    >::type>
763_LIBCPP_INLINE_VISIBILITY
764void __construct_range_forward(_Alloc&, _Source* __begin1, _Source* __end1, _Dest*& __begin2) {
765    ptrdiff_t _Np = __end1 - __begin1;
766    if (_Np > 0) {
767        _VSTD::memcpy(const_cast<_RawDest*>(__begin2), __begin1, _Np * sizeof(_Dest));
768        __begin2 += _Np;
769    }
770}
771
772template <class _Alloc, class _Ptr>
773_LIBCPP_INLINE_VISIBILITY
774void __construct_backward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2) {
775    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
776        "The specified type does not meet the requirements of Cpp17MoveInsertable");
777    typedef allocator_traits<_Alloc> _Traits;
778    while (__end1 != __begin1) {
779        _Traits::construct(__a, _VSTD::__to_address(__end2 - 1),
780#ifdef _LIBCPP_NO_EXCEPTIONS
781            _VSTD::move(*--__end1)
782#else
783            _VSTD::move_if_noexcept(*--__end1)
784#endif
785        );
786        --__end2;
787    }
788}
789
790template <class _Alloc, class _Tp, class = typename enable_if<
791    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
792    is_trivially_move_constructible<_Tp>::value
793>::type>
794_LIBCPP_INLINE_VISIBILITY
795void __construct_backward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2) {
796    ptrdiff_t _Np = __end1 - __begin1;
797    __end2 -= _Np;
798    if (_Np > 0)
799        _VSTD::memcpy(static_cast<void*>(__end2), static_cast<void const*>(__begin1), _Np * sizeof(_Tp));
800}
801
802struct __destruct_n
803{
804private:
805    size_t __size_;
806
807    template <class _Tp>
808    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
809        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
810
811    template <class _Tp>
812    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
813        {}
814
815    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
816        {++__size_;}
817    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
818        {}
819
820    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
821        {__size_ = __s;}
822    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
823        {}
824public:
825    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
826        : __size_(__s) {}
827
828    template <class _Tp>
829    _LIBCPP_INLINE_VISIBILITY void __incr() _NOEXCEPT
830        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
831
832    template <class _Tp>
833    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
834        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
835
836    template <class _Tp>
837    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
838        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
839};
840
841_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
842
843// --- Helper for container swap --
844template <typename _Alloc>
845_LIBCPP_INLINE_VISIBILITY
846void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
847#if _LIBCPP_STD_VER >= 14
848    _NOEXCEPT
849#else
850    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
851#endif
852{
853    using _VSTD::swap;
854    swap(__a1, __a2);
855}
856
857template <typename _Alloc>
858inline _LIBCPP_INLINE_VISIBILITY
859void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
860
861template <typename _Alloc>
862inline _LIBCPP_INLINE_VISIBILITY
863void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
864#if _LIBCPP_STD_VER >= 14
865    _NOEXCEPT
866#else
867    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
868#endif
869{
870    _VSTD::__swap_allocator(__a1, __a2,
871      integral_constant<bool, allocator_traits<_Alloc>::propagate_on_container_swap::value>());
872}
873
874template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
875struct __noexcept_move_assign_container : public integral_constant<bool,
876    _Traits::propagate_on_container_move_assignment::value
877#if _LIBCPP_STD_VER > 14
878        || _Traits::is_always_equal::value
879#else
880        && is_nothrow_move_assignable<_Alloc>::value
881#endif
882    > {};
883
884
885template <class _Tp, class _Alloc>
886struct __temp_value {
887    typedef allocator_traits<_Alloc> _Traits;
888
889    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
890    _Alloc &__a;
891
892    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
893    _Tp &   get() { return *__addr(); }
894
895    template<class... _Args>
896    _LIBCPP_NO_CFI
897    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
898      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
899                         _VSTD::forward<_Args>(__args)...);
900    }
901
902    ~__temp_value() { _Traits::destroy(__a, __addr()); }
903    };
904
905template<typename _Alloc, typename = void, typename = void>
906struct __is_allocator : false_type {};
907
908template<typename _Alloc>
909struct __is_allocator<_Alloc,
910       typename __void_t<typename _Alloc::value_type>::type,
911       typename __void_t<decltype(declval<_Alloc&>().allocate(size_t(0)))>::type
912     >
913   : true_type {};
914
915// __builtin_new_allocator -- A non-templated helper for allocating and
916// deallocating memory using __builtin_operator_new and
917// __builtin_operator_delete. It should be used in preference to
918// `std::allocator<T>` to avoid additional instantiations.
919struct __builtin_new_allocator {
920  struct __builtin_new_deleter {
921    typedef void* pointer_type;
922
923    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
924        : __size_(__size), __align_(__align) {}
925
926    void operator()(void* p) const _NOEXCEPT {
927        _VSTD::__libcpp_deallocate(p, __size_, __align_);
928    }
929
930   private:
931    size_t __size_;
932    size_t __align_;
933  };
934
935  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
936
937  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
938      return __holder_t(_VSTD::__libcpp_allocate(__s, __align),
939                     __builtin_new_deleter(__s, __align));
940  }
941
942  static void __deallocate_bytes(void* __p, size_t __s,
943                                 size_t __align) _NOEXCEPT {
944      _VSTD::__libcpp_deallocate(__p, __s, __align);
945  }
946
947  template <class _Tp>
948  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
949  static __holder_t __allocate_type(size_t __n) {
950      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
951  }
952
953  template <class _Tp>
954  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
955  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
956      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
957  }
958};
959
960
961_LIBCPP_END_NAMESPACE_STD
962
963_LIBCPP_POP_MACROS
964
965#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
966#   include <__pstl_memory>
967#endif
968
969#endif // _LIBCPP_MEMORY
970