xref: /llvm-project-15.0.7/libcxx/include/memory (revision 8a5f0d88)
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> // deprecated in C++17, 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
157    : public iterator<output_iterator_tag, void, void, void, void> // until C++17
158{
159public:
160    explicit raw_storage_iterator(OutputIterator x);
161    raw_storage_iterator& operator*();
162    raw_storage_iterator& operator=(const T& element);
163    raw_storage_iterator& operator++();
164    raw_storage_iterator  operator++(int);
165};
166
167template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
168template <class T> void               return_temporary_buffer(T* p) noexcept;
169
170template <class T> T* addressof(T& r) noexcept;
171template <class T> T* addressof(const T&& r) noexcept = delete;
172
173template <class InputIterator, class ForwardIterator>
174ForwardIterator
175uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
176
177template <class InputIterator, class Size, class ForwardIterator>
178ForwardIterator
179uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
180
181template <class ForwardIterator, class T>
182void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
183
184template <class ForwardIterator, class Size, class T>
185ForwardIterator
186uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
187
188template <class T, class ...Args>
189constexpr T* construct_at(T* location, Args&& ...args); // since C++20
190
191template <class T>
192void destroy_at(T* location); // constexpr in C++20
193
194template <class ForwardIterator>
195void destroy(ForwardIterator first, ForwardIterator last); // constexpr in C++20
196
197template <class ForwardIterator, class Size>
198ForwardIterator destroy_n(ForwardIterator first, Size n); // constexpr in C++20
199
200template <class InputIterator, class ForwardIterator>
201 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
202
203template <class InputIterator, class Size, class ForwardIterator>
204 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
205
206template <class ForwardIterator>
207 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
208
209template <class ForwardIterator, class Size>
210 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
211
212template <class ForwardIterator>
213 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
214
215template <class ForwardIterator, class Size>
216 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
217
218template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
219
220template<class X>
221class auto_ptr                                  // deprecated in C++11, removed in C++17
222{
223public:
224    typedef X element_type;
225
226    explicit auto_ptr(X* p =0) throw();
227    auto_ptr(auto_ptr&) throw();
228    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
229    auto_ptr& operator=(auto_ptr&) throw();
230    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
231    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
232    ~auto_ptr() throw();
233
234    typename add_lvalue_reference<X>::type operator*() const throw();
235    X* operator->() const throw();
236    X* get() const throw();
237    X* release() throw();
238    void reset(X* p =0) throw();
239
240    auto_ptr(auto_ptr_ref<X>) throw();
241    template<class Y> operator auto_ptr_ref<Y>() throw();
242    template<class Y> operator auto_ptr<Y>() throw();
243};
244
245template <class T>
246struct default_delete
247{
248    constexpr default_delete() noexcept = default;
249    template <class U> default_delete(const default_delete<U>&) noexcept;
250
251    void operator()(T*) const noexcept;
252};
253
254template <class T>
255struct default_delete<T[]>
256{
257    constexpr default_delete() noexcept = default;
258    void operator()(T*) const noexcept;
259    template <class U> void operator()(U*) const = delete;
260};
261
262template <class T, class D = default_delete<T>>
263class unique_ptr
264{
265public:
266    typedef see below pointer;
267    typedef T element_type;
268    typedef D deleter_type;
269
270    // constructors
271    constexpr unique_ptr() noexcept;
272    explicit unique_ptr(pointer p) noexcept;
273    unique_ptr(pointer p, see below d1) noexcept;
274    unique_ptr(pointer p, see below d2) noexcept;
275    unique_ptr(unique_ptr&& u) noexcept;
276    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
277    template <class U, class E>
278        unique_ptr(unique_ptr<U, E>&& u) noexcept;
279    template <class U>
280        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
281
282    // destructor
283    ~unique_ptr();
284
285    // assignment
286    unique_ptr& operator=(unique_ptr&& u) noexcept;
287    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
288    unique_ptr& operator=(nullptr_t) noexcept;
289
290    // observers
291    typename add_lvalue_reference<T>::type operator*() const;
292    pointer operator->() const noexcept;
293    pointer get() const noexcept;
294    deleter_type& get_deleter() noexcept;
295    const deleter_type& get_deleter() const noexcept;
296    explicit operator bool() const noexcept;
297
298    // modifiers
299    pointer release() noexcept;
300    void reset(pointer p = pointer()) noexcept;
301    void swap(unique_ptr& u) noexcept;
302};
303
304template <class T, class D>
305class unique_ptr<T[], D>
306{
307public:
308    typedef implementation-defined pointer;
309    typedef T element_type;
310    typedef D deleter_type;
311
312    // constructors
313    constexpr unique_ptr() noexcept;
314    explicit unique_ptr(pointer p) noexcept;
315    unique_ptr(pointer p, see below d) noexcept;
316    unique_ptr(pointer p, see below d) noexcept;
317    unique_ptr(unique_ptr&& u) noexcept;
318    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
319
320    // destructor
321    ~unique_ptr();
322
323    // assignment
324    unique_ptr& operator=(unique_ptr&& u) noexcept;
325    unique_ptr& operator=(nullptr_t) noexcept;
326
327    // observers
328    T& operator[](size_t i) const;
329    pointer get() const noexcept;
330    deleter_type& get_deleter() noexcept;
331    const deleter_type& get_deleter() const noexcept;
332    explicit operator bool() const noexcept;
333
334    // modifiers
335    pointer release() noexcept;
336    void reset(pointer p = pointer()) noexcept;
337    void reset(nullptr_t) noexcept;
338  template <class U> void reset(U) = delete;
339    void swap(unique_ptr& u) noexcept;
340};
341
342template <class T, class D>
343    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
344
345template <class T1, class D1, class T2, class D2>
346    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
347template <class T1, class D1, class T2, class D2>
348    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
349template <class T1, class D1, class T2, class D2>
350    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
351template <class T1, class D1, class T2, class D2>
352    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
353template <class T1, class D1, class T2, class D2>
354    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
355template <class T1, class D1, class T2, class D2>
356    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
357
358template <class T, class D>
359    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
360template <class T, class D>
361    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
362template <class T, class D>
363    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
364template <class T, class D>
365    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
366
367template <class T, class D>
368    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
369template <class T, class D>
370    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
371template <class T, class D>
372    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
373template <class T, class D>
374    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
375template <class T, class D>
376    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
377template <class T, class D>
378    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
379template <class T, class D>
380    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
381template <class T, class D>
382    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
383
384class bad_weak_ptr
385    : public std::exception
386{
387    bad_weak_ptr() noexcept;
388};
389
390template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
391template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
392template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
393
394template<class E, class T, class Y, class D>
395    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
396
397template<class T>
398class shared_ptr
399{
400public:
401    typedef T element_type;
402    typedef weak_ptr<T> weak_type; // C++17
403
404    // constructors:
405    constexpr shared_ptr() noexcept;
406    template<class Y> explicit shared_ptr(Y* p);
407    template<class Y, class D> shared_ptr(Y* p, D d);
408    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
409    template <class D> shared_ptr(nullptr_t p, D d);
410    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
411    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
412    shared_ptr(const shared_ptr& r) noexcept;
413    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
414    shared_ptr(shared_ptr&& r) noexcept;
415    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
416    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
417    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
418    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
419    shared_ptr(nullptr_t) : shared_ptr() { }
420
421    // destructor:
422    ~shared_ptr();
423
424    // assignment:
425    shared_ptr& operator=(const shared_ptr& r) noexcept;
426    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
427    shared_ptr& operator=(shared_ptr&& r) noexcept;
428    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
429    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
430    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
431
432    // modifiers:
433    void swap(shared_ptr& r) noexcept;
434    void reset() noexcept;
435    template<class Y> void reset(Y* p);
436    template<class Y, class D> void reset(Y* p, D d);
437    template<class Y, class D, class A> void reset(Y* p, D d, A a);
438
439    // observers:
440    T* get() const noexcept;
441    T& operator*() const noexcept;
442    T* operator->() const noexcept;
443    long use_count() const noexcept;
444    bool unique() const noexcept;
445    explicit operator bool() const noexcept;
446    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
447    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
448};
449
450template<class T>
451shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
452template<class T, class D>
453shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
454
455// shared_ptr comparisons:
456template<class T, class U>
457    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
458template<class T, class U>
459    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
460template<class T, class U>
461    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
462template<class T, class U>
463    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
464template<class T, class U>
465    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
466template<class T, class U>
467    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
468
469template <class T>
470    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
471template <class T>
472    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
473template <class T>
474    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
475template <class T>
476    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
477template <class T>
478    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
479template <class T>
480bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
481template <class T>
482    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
483template <class T>
484    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
485template <class T>
486    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
487template <class T>
488    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
489template <class T>
490    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
491template <class T>
492    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
493
494// shared_ptr specialized algorithms:
495template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
496
497// shared_ptr casts:
498template<class T, class U>
499    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
500template<class T, class U>
501    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
502template<class T, class U>
503    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
504
505// shared_ptr I/O:
506template<class E, class T, class Y>
507    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
508
509// shared_ptr get_deleter:
510template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
511
512template<class T, class... Args>
513    shared_ptr<T> make_shared(Args&&... args);
514template<class T, class A, class... Args>
515    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
516
517template<class T>
518class weak_ptr
519{
520public:
521    typedef T element_type;
522
523    // constructors
524    constexpr weak_ptr() noexcept;
525    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
526    weak_ptr(weak_ptr const& r) noexcept;
527    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
528    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
529    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
530
531    // destructor
532    ~weak_ptr();
533
534    // assignment
535    weak_ptr& operator=(weak_ptr const& r) noexcept;
536    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
537    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
538    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
539    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
540
541    // modifiers
542    void swap(weak_ptr& r) noexcept;
543    void reset() noexcept;
544
545    // observers
546    long use_count() const noexcept;
547    bool expired() const noexcept;
548    shared_ptr<T> lock() const noexcept;
549    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
550    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
551};
552
553template<class T>
554weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
555
556// weak_ptr specialized algorithms:
557template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
558
559// class owner_less:
560template<class T> struct owner_less;
561
562template<class T>
563struct owner_less<shared_ptr<T> >
564    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
565{
566    typedef bool result_type;
567    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
568    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
569    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
570};
571
572template<class T>
573struct owner_less<weak_ptr<T> >
574    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
575{
576    typedef bool result_type;
577    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
578    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
579    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
580};
581
582template <>  // Added in C++14
583struct owner_less<void>
584{
585    template <class _Tp, class _Up>
586    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
587    template <class _Tp, class _Up>
588    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
589    template <class _Tp, class _Up>
590    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
591    template <class _Tp, class _Up>
592    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
593
594    typedef void is_transparent;
595};
596
597template<class T>
598class enable_shared_from_this
599{
600protected:
601    constexpr enable_shared_from_this() noexcept;
602    enable_shared_from_this(enable_shared_from_this const&) noexcept;
603    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
604    ~enable_shared_from_this();
605public:
606    shared_ptr<T> shared_from_this();
607    shared_ptr<T const> shared_from_this() const;
608};
609
610template<class T>
611    bool atomic_is_lock_free(const shared_ptr<T>* p);
612template<class T>
613    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
614template<class T>
615    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
616template<class T>
617    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
618template<class T>
619    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
620template<class T>
621    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
622template<class T>
623    shared_ptr<T>
624    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
625template<class T>
626    bool
627    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
628template<class T>
629    bool
630    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
631template<class T>
632    bool
633    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
634                                          shared_ptr<T> w, memory_order success,
635                                          memory_order failure);
636template<class T>
637    bool
638    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
639                                            shared_ptr<T> w, memory_order success,
640                                            memory_order failure);
641// Hash support
642template <class T> struct hash;
643template <class T, class D> struct hash<unique_ptr<T, D> >;
644template <class T> struct hash<shared_ptr<T> >;
645
646template <class T, class Alloc>
647  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
648
649// Pointer safety
650enum class pointer_safety { relaxed, preferred, strict }; // since C++11
651void declare_reachable(void *p);                          // since C++11
652template <class T> T *undeclare_reachable(T *p);          // since C++11
653void declare_no_pointers(char *p, size_t n);              // since C++11
654void undeclare_no_pointers(char *p, size_t n);            // since C++11
655pointer_safety get_pointer_safety() noexcept;             // since C++11
656
657void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
658
659}  // std
660
661*/
662
663#include <__config>
664#include <type_traits>
665#include <typeinfo>
666#include <compare>
667#include <cstddef>
668#include <cstdint>
669#include <new>
670#include <utility>
671#include <iterator>
672#include <__functional_base>
673#include <iosfwd>
674#include <tuple>
675#include <stdexcept>
676#include <cstring>
677#include <__memory/addressof.h>
678#include <__memory/allocation_guard.h>
679#include <__memory/allocator.h>
680#include <__memory/allocator_traits.h>
681#include <__memory/compressed_pair.h>
682#include <__memory/construct_at.h>
683#include <__memory/pointer_safety.h>
684#include <__memory/pointer_traits.h>
685#include <__memory/raw_storage_iterator.h>
686#include <__memory/shared_ptr.h>
687#include <__memory/temporary_buffer.h>
688#include <__memory/uninitialized_algorithms.h>
689#include <__memory/unique_ptr.h>
690#include <version>
691
692#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
693#   include <__memory/auto_ptr.h>
694#endif
695
696#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
697#pragma GCC system_header
698#endif
699
700_LIBCPP_PUSH_MACROS
701#include <__undef_macros>
702
703
704_LIBCPP_BEGIN_NAMESPACE_STD
705
706template <class _Alloc, class _Ptr>
707_LIBCPP_INLINE_VISIBILITY
708void __construct_forward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2) {
709    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
710        "The specified type does not meet the requirements of Cpp17MoveInsertable");
711    typedef allocator_traits<_Alloc> _Traits;
712    for (; __begin1 != __end1; ++__begin1, (void)++__begin2) {
713        _Traits::construct(__a, _VSTD::__to_address(__begin2),
714#ifdef _LIBCPP_NO_EXCEPTIONS
715            _VSTD::move(*__begin1)
716#else
717            _VSTD::move_if_noexcept(*__begin1)
718#endif
719        );
720    }
721}
722
723template <class _Alloc, class _Tp, typename enable_if<
724    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
725    is_trivially_move_constructible<_Tp>::value
726>::type>
727_LIBCPP_INLINE_VISIBILITY
728void __construct_forward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2) {
729    ptrdiff_t _Np = __end1 - __begin1;
730    if (_Np > 0) {
731        _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
732        __begin2 += _Np;
733    }
734}
735
736template <class _Alloc, class _Iter, class _Ptr>
737_LIBCPP_INLINE_VISIBILITY
738void __construct_range_forward(_Alloc& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2) {
739    typedef allocator_traits<_Alloc> _Traits;
740    for (; __begin1 != __end1; ++__begin1, (void) ++__begin2) {
741        _Traits::construct(__a, _VSTD::__to_address(__begin2), *__begin1);
742    }
743}
744
745template <class _Alloc, class _Source, class _Dest,
746          class _RawSource = typename remove_const<_Source>::type,
747          class _RawDest = typename remove_const<_Dest>::type,
748          class =
749    typename enable_if<
750        is_trivially_copy_constructible<_Dest>::value &&
751        is_same<_RawSource, _RawDest>::value &&
752        (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Dest*, _Source&>::value)
753    >::type>
754_LIBCPP_INLINE_VISIBILITY
755void __construct_range_forward(_Alloc&, _Source* __begin1, _Source* __end1, _Dest*& __begin2) {
756    ptrdiff_t _Np = __end1 - __begin1;
757    if (_Np > 0) {
758        _VSTD::memcpy(const_cast<_RawDest*>(__begin2), __begin1, _Np * sizeof(_Dest));
759        __begin2 += _Np;
760    }
761}
762
763template <class _Alloc, class _Ptr>
764_LIBCPP_INLINE_VISIBILITY
765void __construct_backward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2) {
766    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
767        "The specified type does not meet the requirements of Cpp17MoveInsertable");
768    typedef allocator_traits<_Alloc> _Traits;
769    while (__end1 != __begin1) {
770        _Traits::construct(__a, _VSTD::__to_address(__end2 - 1),
771#ifdef _LIBCPP_NO_EXCEPTIONS
772            _VSTD::move(*--__end1)
773#else
774            _VSTD::move_if_noexcept(*--__end1)
775#endif
776        );
777        --__end2;
778    }
779}
780
781template <class _Alloc, class _Tp, class = typename enable_if<
782    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
783    is_trivially_move_constructible<_Tp>::value
784>::type>
785_LIBCPP_INLINE_VISIBILITY
786void __construct_backward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2) {
787    ptrdiff_t _Np = __end1 - __begin1;
788    __end2 -= _Np;
789    if (_Np > 0)
790        _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
791}
792
793struct __destruct_n
794{
795private:
796    size_t __size_;
797
798    template <class _Tp>
799    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
800        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
801
802    template <class _Tp>
803    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
804        {}
805
806    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
807        {++__size_;}
808    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
809        {}
810
811    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
812        {__size_ = __s;}
813    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
814        {}
815public:
816    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
817        : __size_(__s) {}
818
819    template <class _Tp>
820    _LIBCPP_INLINE_VISIBILITY void __incr() _NOEXCEPT
821        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
822
823    template <class _Tp>
824    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
825        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
826
827    template <class _Tp>
828    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
829        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
830};
831
832_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
833
834// --- Helper for container swap --
835template <typename _Alloc>
836_LIBCPP_INLINE_VISIBILITY
837void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
838#if _LIBCPP_STD_VER >= 14
839    _NOEXCEPT
840#else
841    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
842#endif
843{
844    using _VSTD::swap;
845    swap(__a1, __a2);
846}
847
848template <typename _Alloc>
849inline _LIBCPP_INLINE_VISIBILITY
850void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
851
852template <typename _Alloc>
853inline _LIBCPP_INLINE_VISIBILITY
854void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
855#if _LIBCPP_STD_VER >= 14
856    _NOEXCEPT
857#else
858    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
859#endif
860{
861    _VSTD::__swap_allocator(__a1, __a2,
862      integral_constant<bool, allocator_traits<_Alloc>::propagate_on_container_swap::value>());
863}
864
865template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
866struct __noexcept_move_assign_container : public integral_constant<bool,
867    _Traits::propagate_on_container_move_assignment::value
868#if _LIBCPP_STD_VER > 14
869        || _Traits::is_always_equal::value
870#else
871        && is_nothrow_move_assignable<_Alloc>::value
872#endif
873    > {};
874
875
876template <class _Tp, class _Alloc>
877struct __temp_value {
878    typedef allocator_traits<_Alloc> _Traits;
879
880    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
881    _Alloc &__a;
882
883    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
884    _Tp &   get() { return *__addr(); }
885
886    template<class... _Args>
887    _LIBCPP_NO_CFI
888    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
889      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
890                         _VSTD::forward<_Args>(__args)...);
891    }
892
893    ~__temp_value() { _Traits::destroy(__a, __addr()); }
894    };
895
896template<typename _Alloc, typename = void, typename = void>
897struct __is_allocator : false_type {};
898
899template<typename _Alloc>
900struct __is_allocator<_Alloc,
901       typename __void_t<typename _Alloc::value_type>::type,
902       typename __void_t<decltype(declval<_Alloc&>().allocate(size_t(0)))>::type
903     >
904   : true_type {};
905
906// __builtin_new_allocator -- A non-templated helper for allocating and
907// deallocating memory using __builtin_operator_new and
908// __builtin_operator_delete. It should be used in preference to
909// `std::allocator<T>` to avoid additional instantiations.
910struct __builtin_new_allocator {
911  struct __builtin_new_deleter {
912    typedef void* pointer_type;
913
914    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
915        : __size_(__size), __align_(__align) {}
916
917    void operator()(void* p) const _NOEXCEPT {
918        _VSTD::__libcpp_deallocate(p, __size_, __align_);
919    }
920
921   private:
922    size_t __size_;
923    size_t __align_;
924  };
925
926  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
927
928  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
929      return __holder_t(_VSTD::__libcpp_allocate(__s, __align),
930                     __builtin_new_deleter(__s, __align));
931  }
932
933  static void __deallocate_bytes(void* __p, size_t __s,
934                                 size_t __align) _NOEXCEPT {
935      _VSTD::__libcpp_deallocate(__p, __s, __align);
936  }
937
938  template <class _Tp>
939  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
940  static __holder_t __allocate_type(size_t __n) {
941      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
942  }
943
944  template <class _Tp>
945  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
946  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
947      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
948  }
949};
950
951
952_LIBCPP_END_NAMESPACE_STD
953
954_LIBCPP_POP_MACROS
955
956#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
957#   include <__pstl_memory>
958#endif
959
960#endif // _LIBCPP_MEMORY
961