xref: /llvm-project-15.0.7/libcxx/include/memory (revision 9d5e37ed)
1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_MEMORY
11#define _LIBCPP_MEMORY
12
13/*
14    memory synopsis
15
16namespace std
17{
18
19struct allocator_arg_t { };
20inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();
21
22template <class T, class Alloc> struct uses_allocator;
23
24template <class Ptr>
25struct pointer_traits
26{
27    typedef Ptr pointer;
28    typedef <details> element_type;
29    typedef <details> difference_type;
30
31    template <class U> using rebind = <details>;
32
33    static pointer pointer_to(<details>);
34};
35
36template <class T>
37struct pointer_traits<T*>
38{
39    typedef T* pointer;
40    typedef T element_type;
41    typedef ptrdiff_t difference_type;
42
43    template <class U> using rebind = U*;
44
45    static pointer pointer_to(<details>) noexcept; // constexpr in C++20
46};
47
48template <class T> constexpr T* to_address(T* p) noexcept; // C++20
49template <class Ptr> constexpr auto to_address(const Ptr& p) noexcept; // C++20
50
51template <class Alloc>
52struct allocator_traits
53{
54    typedef Alloc                        allocator_type;
55    typedef typename allocator_type::value_type
56                                         value_type;
57
58    typedef Alloc::pointer | value_type* pointer;
59    typedef Alloc::const_pointer
60          | pointer_traits<pointer>::rebind<const value_type>
61                                         const_pointer;
62    typedef Alloc::void_pointer
63          | pointer_traits<pointer>::rebind<void>
64                                         void_pointer;
65    typedef Alloc::const_void_pointer
66          | pointer_traits<pointer>::rebind<const void>
67                                         const_void_pointer;
68    typedef Alloc::difference_type
69          | pointer_traits<pointer>::difference_type
70                                         difference_type;
71    typedef Alloc::size_type
72          | make_unsigned<difference_type>::type
73                                         size_type;
74    typedef Alloc::propagate_on_container_copy_assignment
75          | false_type                   propagate_on_container_copy_assignment;
76    typedef Alloc::propagate_on_container_move_assignment
77          | false_type                   propagate_on_container_move_assignment;
78    typedef Alloc::propagate_on_container_swap
79          | false_type                   propagate_on_container_swap;
80    typedef Alloc::is_always_equal
81          | is_empty                     is_always_equal;
82
83    template <class T> using rebind_alloc  = Alloc::rebind<T>::other | Alloc<T, Args...>;
84    template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
85
86    static pointer allocate(allocator_type& a, size_type n);                          // constexpr and [[nodiscard]] in C++20
87    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint); // constexpr and [[nodiscard]] in C++20
88
89    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept; // constexpr in C++20
90
91    template <class T, class... Args>
92    static void construct(allocator_type& a, T* p, Args&&... args); // constexpr in C++20
93
94    template <class T>
95    static void destroy(allocator_type& a, T* p); // constexpr in C++20
96
97    static size_type max_size(const allocator_type& a); // noexcept in C++14, constexpr in C++20
98    static allocator_type select_on_container_copy_construction(const allocator_type& a); // constexpr in C++20
99};
100
101template <>
102class allocator<void> // removed in C++20
103{
104public:
105    typedef void*                                 pointer;
106    typedef const void*                           const_pointer;
107    typedef void                                  value_type;
108
109    template <class _Up> struct rebind {typedef allocator<_Up> other;};
110};
111
112template <class T>
113class allocator
114{
115public:
116    typedef size_t    size_type;
117    typedef ptrdiff_t difference_type;
118    typedef T*        pointer;                           // deprecated in C++17, removed in C++20
119    typedef const T*  const_pointer;                     // deprecated in C++17, removed in C++20
120    typedef typename add_lvalue_reference<T>::type
121                      reference;                         // deprecated in C++17, removed in C++20
122    typedef typename add_lvalue_reference<const T>::type
123                      const_reference;                   // deprecated in C++17, removed in C++20
124
125    typedef T         value_type;
126
127    template <class U> struct rebind {typedef allocator<U> other;}; // deprecated in C++17, removed in C++20
128
129    typedef true_type propagate_on_container_move_assignment;
130    typedef true_type is_always_equal;
131
132    constexpr allocator() noexcept;                      // constexpr in C++20
133    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
134    template <class U>
135      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
136    ~allocator();                                        // constexpr in C++20
137    pointer address(reference x) const noexcept;             // deprecated in C++17, removed in C++20
138    const_pointer address(const_reference x) const noexcept; // deprecated in C++17, removed in C++20
139    T* allocate(size_t n, const void* hint);          // deprecated in C++17, removed in C++20
140    T* allocate(size_t n);                              // constexpr in C++20
141    void deallocate(T* p, size_t n) noexcept;           // constexpr in C++20
142    size_type max_size() const noexcept;              // deprecated in C++17, removed in C++20
143    template<class U, class... Args>
144        void construct(U* p, Args&&... args);         // deprecated in C++17, removed in C++20
145    template <class U>
146        void destroy(U* p);                           // deprecated in C++17, removed in C++20
147};
148
149template <class T, class U>
150bool operator==(const allocator<T>&, const allocator<U>&) noexcept; // constexpr in C++20
151
152template <class T, class U>
153bool operator!=(const allocator<T>&, const allocator<U>&) noexcept; // constexpr in C++20
154
155template <class OutputIterator, class T>
156class raw_storage_iterator // deprecated in C++17, removed in C++20
157    : public iterator<output_iterator_tag, void, void, void, void> // until C++17
158{
159public:
160    typedef output_iterator_tag iterator_category;
161    typedef void                value_type;
162    typedef void                difference_type; // until C++20
163    typedef ptrdiff_t           difference_type; // since C++20
164    typedef void                pointer;
165    typedef void                reference;
166
167    explicit raw_storage_iterator(OutputIterator x);
168    raw_storage_iterator& operator*();
169    raw_storage_iterator& operator=(const T& element);
170    raw_storage_iterator& operator++();
171    raw_storage_iterator  operator++(int);
172};
173
174template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
175template <class T> void               return_temporary_buffer(T* p) noexcept;
176
177template <class T> T* addressof(T& r) noexcept;
178template <class T> T* addressof(const T&& r) noexcept = delete;
179
180template <class InputIterator, class ForwardIterator>
181ForwardIterator
182uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
183
184template <class InputIterator, class Size, class ForwardIterator>
185ForwardIterator
186uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
187
188template <class ForwardIterator, class T>
189void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
190
191template <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 <nothrow-forward-iterator ForwardIterator, nothrow-sentinel-for<ForwardIterator> Sentinel>
223  requires default_initializable<iter_value_t<ForwardIterator>>
224 ForwardIterator ranges::uninitialized_default_construct(ForwardIterator first, Sentinel last); // since C++20
225
226template <nothrow-forward-range ForwardRange>
227  requires default_initializable<range_value_t<ForwardRange>>
228 borrowed_iterator_t<ForwardRange> ranges::uninitialized_default_construct(ForwardRange&& r); // since C++20
229
230template <class ForwardIterator, class Size>
231 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
232
233template <nothrow-forward-iterator ForwardIterator>
234  requires default_initializable<iter_value_t<ForwardIterator>>
235 ForwardIterator ranges::uninitialized_default_construct_n(ForwardIterator first, iter_difference_t<ForwardIterator> n); // since C++20
236
237template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
238
239template<class X>
240class auto_ptr                                  // deprecated in C++11, removed in C++17
241{
242public:
243    typedef X element_type;
244
245    explicit auto_ptr(X* p =0) throw();
246    auto_ptr(auto_ptr&) throw();
247    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
248    auto_ptr& operator=(auto_ptr&) throw();
249    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
250    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
251    ~auto_ptr() throw();
252
253    typename add_lvalue_reference<X>::type operator*() const throw();
254    X* operator->() const throw();
255    X* get() const throw();
256    X* release() throw();
257    void reset(X* p =0) throw();
258
259    auto_ptr(auto_ptr_ref<X>) throw();
260    template<class Y> operator auto_ptr_ref<Y>() throw();
261    template<class Y> operator auto_ptr<Y>() throw();
262};
263
264template <class T>
265struct default_delete
266{
267    constexpr default_delete() noexcept = default;
268    template <class U> default_delete(const default_delete<U>&) noexcept;
269
270    void operator()(T*) const noexcept;
271};
272
273template <class T>
274struct default_delete<T[]>
275{
276    constexpr default_delete() noexcept = default;
277    void operator()(T*) const noexcept;
278    template <class U> void operator()(U*) const = delete;
279};
280
281template <class T, class D = default_delete<T>>
282class unique_ptr
283{
284public:
285    typedef see below pointer;
286    typedef T element_type;
287    typedef D deleter_type;
288
289    // constructors
290    constexpr unique_ptr() noexcept;
291    explicit unique_ptr(pointer p) noexcept;
292    unique_ptr(pointer p, see below d1) noexcept;
293    unique_ptr(pointer p, see below d2) noexcept;
294    unique_ptr(unique_ptr&& u) noexcept;
295    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
296    template <class U, class E>
297        unique_ptr(unique_ptr<U, E>&& u) noexcept;
298    template <class U>
299        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
300
301    // destructor
302    ~unique_ptr();
303
304    // assignment
305    unique_ptr& operator=(unique_ptr&& u) noexcept;
306    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
307    unique_ptr& operator=(nullptr_t) noexcept;
308
309    // observers
310    typename add_lvalue_reference<T>::type operator*() const;
311    pointer operator->() const noexcept;
312    pointer get() const noexcept;
313    deleter_type& get_deleter() noexcept;
314    const deleter_type& get_deleter() const noexcept;
315    explicit operator bool() const noexcept;
316
317    // modifiers
318    pointer release() noexcept;
319    void reset(pointer p = pointer()) noexcept;
320    void swap(unique_ptr& u) noexcept;
321};
322
323template <class T, class D>
324class unique_ptr<T[], D>
325{
326public:
327    typedef implementation-defined pointer;
328    typedef T element_type;
329    typedef D deleter_type;
330
331    // constructors
332    constexpr unique_ptr() noexcept;
333    explicit unique_ptr(pointer p) noexcept;
334    unique_ptr(pointer p, see below d) noexcept;
335    unique_ptr(pointer p, see below d) noexcept;
336    unique_ptr(unique_ptr&& u) noexcept;
337    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
338
339    // destructor
340    ~unique_ptr();
341
342    // assignment
343    unique_ptr& operator=(unique_ptr&& u) noexcept;
344    unique_ptr& operator=(nullptr_t) noexcept;
345
346    // observers
347    T& operator[](size_t i) const;
348    pointer get() const noexcept;
349    deleter_type& get_deleter() noexcept;
350    const deleter_type& get_deleter() const noexcept;
351    explicit operator bool() const noexcept;
352
353    // modifiers
354    pointer release() noexcept;
355    void reset(pointer p = pointer()) noexcept;
356    void reset(nullptr_t) noexcept;
357  template <class U> void reset(U) = delete;
358    void swap(unique_ptr& u) noexcept;
359};
360
361template <class T, class D>
362    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
363
364template <class T1, class D1, class T2, class D2>
365    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
366template <class T1, class D1, class T2, class D2>
367    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
368template <class T1, class D1, class T2, class D2>
369    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
370template <class T1, class D1, class T2, class D2>
371    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
372template <class T1, class D1, class T2, class D2>
373    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
374template <class T1, class D1, class T2, class D2>
375    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
376
377template <class T, class D>
378    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
379template <class T, class D>
380    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
381template <class T, class D>
382    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
383template <class T, class D>
384    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
385
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);
390template <class T, class D>
391    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
392template <class T, class D>
393    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
394template <class T, class D>
395    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
396template <class T, class D>
397    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
398template <class T, class D>
399    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
400template <class T, class D>
401    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
402
403class bad_weak_ptr
404    : public std::exception
405{
406    bad_weak_ptr() noexcept;
407};
408
409template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
410template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
411template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
412
413template<class E, class T, class Y, class D>
414    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
415
416template<class T>
417class shared_ptr
418{
419public:
420    typedef T element_type; // until C++17
421    typedef remove_extent_t<T> element_type; // since C++17
422    typedef weak_ptr<T> weak_type; // C++17
423
424    // constructors:
425    constexpr shared_ptr() noexcept;
426    template<class Y> explicit shared_ptr(Y* p);
427    template<class Y, class D> shared_ptr(Y* p, D d);
428    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
429    template <class D> shared_ptr(nullptr_t p, D d);
430    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
431    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
432    shared_ptr(const shared_ptr& r) noexcept;
433    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
434    shared_ptr(shared_ptr&& r) noexcept;
435    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
436    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
437    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
438    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
439    shared_ptr(nullptr_t) : shared_ptr() { }
440
441    // destructor:
442    ~shared_ptr();
443
444    // assignment:
445    shared_ptr& operator=(const shared_ptr& r) noexcept;
446    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
447    shared_ptr& operator=(shared_ptr&& r) noexcept;
448    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
449    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
450    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
451
452    // modifiers:
453    void swap(shared_ptr& r) noexcept;
454    void reset() noexcept;
455    template<class Y> void reset(Y* p);
456    template<class Y, class D> void reset(Y* p, D d);
457    template<class Y, class D, class A> void reset(Y* p, D d, A a);
458
459    // observers:
460    T* get() const noexcept;
461    T& operator*() const noexcept;
462    T* operator->() const noexcept;
463    long use_count() const noexcept;
464    bool unique() const noexcept;
465    explicit operator bool() const noexcept;
466    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
467    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
468};
469
470template<class T>
471shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
472template<class T, class D>
473shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
474
475// shared_ptr comparisons:
476template<class T, class U>
477    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
478template<class T, class U>
479    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
480template<class T, class U>
481    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
482template<class T, class U>
483    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
484template<class T, class U>
485    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
486template<class T, class U>
487    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
488
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;
493template <class T>
494    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
495template <class T>
496    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
497template <class T>
498    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
499template <class T>
500bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
501template <class T>
502    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
503template <class T>
504    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
505template <class T>
506    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
507template <class T>
508    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
509template <class T>
510    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
511template <class T>
512    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
513
514// shared_ptr specialized algorithms:
515template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
516
517// shared_ptr casts:
518template<class T, class U>
519    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
520template<class T, class U>
521    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
522template<class T, class U>
523    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
524
525// shared_ptr I/O:
526template<class E, class T, class Y>
527    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
528
529// shared_ptr get_deleter:
530template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
531
532template<class T, class... Args>
533    shared_ptr<T> make_shared(Args&&... args);
534template<class T, class A, class... Args>
535    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
536
537template<class T>
538class weak_ptr
539{
540public:
541    typedef T element_type; // until C++17
542    typedef remove_extent_t<T> element_type; // since C++17
543
544    // constructors
545    constexpr weak_ptr() noexcept;
546    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
547    weak_ptr(weak_ptr const& r) noexcept;
548    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
549    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
550    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
551
552    // destructor
553    ~weak_ptr();
554
555    // assignment
556    weak_ptr& operator=(weak_ptr const& r) noexcept;
557    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
558    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
559    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
560    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
561
562    // modifiers
563    void swap(weak_ptr& r) noexcept;
564    void reset() noexcept;
565
566    // observers
567    long use_count() const noexcept;
568    bool expired() const noexcept;
569    shared_ptr<T> lock() const noexcept;
570    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
571    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
572};
573
574template<class T>
575weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
576
577// weak_ptr specialized algorithms:
578template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
579
580// class owner_less:
581template<class T> struct owner_less;
582
583template<class T>
584struct owner_less<shared_ptr<T> >
585    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
586{
587    typedef bool result_type;
588    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
589    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
590    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
591};
592
593template<class T>
594struct owner_less<weak_ptr<T> >
595    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
596{
597    typedef bool result_type;
598    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
599    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
600    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
601};
602
603template <>  // Added in C++14
604struct owner_less<void>
605{
606    template <class _Tp, class _Up>
607    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
608    template <class _Tp, class _Up>
609    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
610    template <class _Tp, class _Up>
611    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
612    template <class _Tp, class _Up>
613    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
614
615    typedef void is_transparent;
616};
617
618template<class T>
619class enable_shared_from_this
620{
621protected:
622    constexpr enable_shared_from_this() noexcept;
623    enable_shared_from_this(enable_shared_from_this const&) noexcept;
624    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
625    ~enable_shared_from_this();
626public:
627    shared_ptr<T> shared_from_this();
628    shared_ptr<T const> shared_from_this() const;
629};
630
631template<class T>
632    bool atomic_is_lock_free(const shared_ptr<T>* p);
633template<class T>
634    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
635template<class T>
636    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
637template<class T>
638    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
639template<class T>
640    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
641template<class T>
642    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
643template<class T>
644    shared_ptr<T>
645    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
646template<class T>
647    bool
648    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
649template<class T>
650    bool
651    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
652template<class T>
653    bool
654    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
655                                          shared_ptr<T> w, memory_order success,
656                                          memory_order failure);
657template<class T>
658    bool
659    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
660                                            shared_ptr<T> w, memory_order success,
661                                            memory_order failure);
662// Hash support
663template <class T> struct hash;
664template <class T, class D> struct hash<unique_ptr<T, D> >;
665template <class T> struct hash<shared_ptr<T> >;
666
667template <class T, class Alloc>
668  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
669
670void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
671
672}  // std
673
674*/
675
676#include <__config>
677#include <__functional_base>
678#include <__memory/addressof.h>
679#include <__memory/allocation_guard.h>
680#include <__memory/allocator.h>
681#include <__memory/allocator_arg_t.h>
682#include <__memory/allocator_traits.h>
683#include <__memory/compressed_pair.h>
684#include <__memory/concepts.h>
685#include <__memory/construct_at.h>
686#include <__memory/pointer_traits.h>
687#include <__memory/ranges_uninitialized_algorithms.h>
688#include <__memory/raw_storage_iterator.h>
689#include <__memory/shared_ptr.h>
690#include <__memory/temporary_buffer.h>
691#include <__memory/uninitialized_algorithms.h>
692#include <__memory/unique_ptr.h>
693#include <__memory/uses_allocator.h>
694#include <compare>
695#include <cstddef>
696#include <cstdint>
697#include <cstring>
698#include <iosfwd>
699#include <iterator>
700#include <new>
701#include <stdexcept>
702#include <tuple>
703#include <type_traits>
704#include <typeinfo>
705#include <utility>
706#include <version>
707
708#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
709#   include <__memory/auto_ptr.h>
710#endif
711
712#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
713#pragma GCC system_header
714#endif
715
716_LIBCPP_BEGIN_NAMESPACE_STD
717
718template <class _Alloc, class _Ptr>
719_LIBCPP_INLINE_VISIBILITY
720void __construct_forward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2) {
721    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
722        "The specified type does not meet the requirements of Cpp17MoveInsertable");
723    typedef allocator_traits<_Alloc> _Traits;
724    for (; __begin1 != __end1; ++__begin1, (void)++__begin2) {
725        _Traits::construct(__a, _VSTD::__to_address(__begin2),
726#ifdef _LIBCPP_NO_EXCEPTIONS
727            _VSTD::move(*__begin1)
728#else
729            _VSTD::move_if_noexcept(*__begin1)
730#endif
731        );
732    }
733}
734
735template <class _Alloc, class _Tp, typename enable_if<
736    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
737    is_trivially_move_constructible<_Tp>::value
738>::type>
739_LIBCPP_INLINE_VISIBILITY
740void __construct_forward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2) {
741    ptrdiff_t _Np = __end1 - __begin1;
742    if (_Np > 0) {
743        _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
744        __begin2 += _Np;
745    }
746}
747
748template <class _Alloc, class _Iter, class _Ptr>
749_LIBCPP_INLINE_VISIBILITY
750void __construct_range_forward(_Alloc& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2) {
751    typedef allocator_traits<_Alloc> _Traits;
752    for (; __begin1 != __end1; ++__begin1, (void) ++__begin2) {
753        _Traits::construct(__a, _VSTD::__to_address(__begin2), *__begin1);
754    }
755}
756
757template <class _Alloc, class _Source, class _Dest,
758          class _RawSource = typename remove_const<_Source>::type,
759          class _RawDest = typename remove_const<_Dest>::type,
760          class =
761    typename enable_if<
762        is_trivially_copy_constructible<_Dest>::value &&
763        is_same<_RawSource, _RawDest>::value &&
764        (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Dest*, _Source&>::value)
765    >::type>
766_LIBCPP_INLINE_VISIBILITY
767void __construct_range_forward(_Alloc&, _Source* __begin1, _Source* __end1, _Dest*& __begin2) {
768    ptrdiff_t _Np = __end1 - __begin1;
769    if (_Np > 0) {
770        _VSTD::memcpy(const_cast<_RawDest*>(__begin2), __begin1, _Np * sizeof(_Dest));
771        __begin2 += _Np;
772    }
773}
774
775template <class _Alloc, class _Ptr>
776_LIBCPP_INLINE_VISIBILITY
777void __construct_backward_with_exception_guarantees(_Alloc& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2) {
778    static_assert(__is_cpp17_move_insertable<_Alloc>::value,
779        "The specified type does not meet the requirements of Cpp17MoveInsertable");
780    typedef allocator_traits<_Alloc> _Traits;
781    while (__end1 != __begin1) {
782        _Traits::construct(__a, _VSTD::__to_address(__end2 - 1),
783#ifdef _LIBCPP_NO_EXCEPTIONS
784            _VSTD::move(*--__end1)
785#else
786            _VSTD::move_if_noexcept(*--__end1)
787#endif
788        );
789        --__end2;
790    }
791}
792
793template <class _Alloc, class _Tp, class = typename enable_if<
794    (__is_default_allocator<_Alloc>::value || !__has_construct<_Alloc, _Tp*, _Tp>::value) &&
795    is_trivially_move_constructible<_Tp>::value
796>::type>
797_LIBCPP_INLINE_VISIBILITY
798void __construct_backward_with_exception_guarantees(_Alloc&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2) {
799    ptrdiff_t _Np = __end1 - __begin1;
800    __end2 -= _Np;
801    if (_Np > 0)
802        _VSTD::memcpy(static_cast<void*>(__end2), static_cast<void const*>(__begin1), _Np * sizeof(_Tp));
803}
804
805struct __destruct_n
806{
807private:
808    size_t __size_;
809
810    template <class _Tp>
811    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
812        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
813
814    template <class _Tp>
815    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
816        {}
817
818    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
819        {++__size_;}
820    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
821        {}
822
823    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
824        {__size_ = __s;}
825    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
826        {}
827public:
828    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
829        : __size_(__s) {}
830
831    template <class _Tp>
832    _LIBCPP_INLINE_VISIBILITY void __incr() _NOEXCEPT
833        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
834
835    template <class _Tp>
836    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
837        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
838
839    template <class _Tp>
840    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
841        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
842};
843
844_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
845
846// --- Helper for container swap --
847template <typename _Alloc>
848_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
849void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
850#if _LIBCPP_STD_VER > 11
851    _NOEXCEPT
852#else
853    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
854#endif
855{
856    using _VSTD::swap;
857    swap(__a1, __a2);
858}
859
860template <typename _Alloc>
861inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
862void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
863
864template <typename _Alloc>
865inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_AFTER_CXX11
866void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
867#if _LIBCPP_STD_VER > 11
868    _NOEXCEPT
869#else
870    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
871#endif
872{
873    _VSTD::__swap_allocator(__a1, __a2,
874      integral_constant<bool, allocator_traits<_Alloc>::propagate_on_container_swap::value>());
875}
876
877template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
878struct __noexcept_move_assign_container : public integral_constant<bool,
879    _Traits::propagate_on_container_move_assignment::value
880#if _LIBCPP_STD_VER > 14
881        || _Traits::is_always_equal::value
882#else
883        && is_nothrow_move_assignable<_Alloc>::value
884#endif
885    > {};
886
887
888template <class _Tp, class _Alloc>
889struct __temp_value {
890    typedef allocator_traits<_Alloc> _Traits;
891
892    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
893    _Alloc &__a;
894
895    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
896    _Tp &   get() { return *__addr(); }
897
898    template<class... _Args>
899    _LIBCPP_NO_CFI
900    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
901      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
902                         _VSTD::forward<_Args>(__args)...);
903    }
904
905    ~__temp_value() { _Traits::destroy(__a, __addr()); }
906    };
907
908template<typename _Alloc, typename = void, typename = void>
909struct __is_allocator : false_type {};
910
911template<typename _Alloc>
912struct __is_allocator<_Alloc,
913       typename __void_t<typename _Alloc::value_type>::type,
914       typename __void_t<decltype(declval<_Alloc&>().allocate(size_t(0)))>::type
915     >
916   : true_type {};
917
918// __builtin_new_allocator -- A non-templated helper for allocating and
919// deallocating memory using __builtin_operator_new and
920// __builtin_operator_delete. It should be used in preference to
921// `std::allocator<T>` to avoid additional instantiations.
922struct __builtin_new_allocator {
923  struct __builtin_new_deleter {
924    typedef void* pointer_type;
925
926    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
927        : __size_(__size), __align_(__align) {}
928
929    void operator()(void* p) const _NOEXCEPT {
930        _VSTD::__libcpp_deallocate(p, __size_, __align_);
931    }
932
933   private:
934    size_t __size_;
935    size_t __align_;
936  };
937
938  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
939
940  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
941      return __holder_t(_VSTD::__libcpp_allocate(__s, __align),
942                     __builtin_new_deleter(__s, __align));
943  }
944
945  static void __deallocate_bytes(void* __p, size_t __s,
946                                 size_t __align) _NOEXCEPT {
947      _VSTD::__libcpp_deallocate(__p, __s, __align);
948  }
949
950  template <class _Tp>
951  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
952  static __holder_t __allocate_type(size_t __n) {
953      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
954  }
955
956  template <class _Tp>
957  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
958  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
959      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
960  }
961};
962
963
964_LIBCPP_END_NAMESPACE_STD
965
966#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
967#   include <__pstl_memory>
968#endif
969
970#endif // _LIBCPP_MEMORY
971