xref: /llvm-project-15.0.7/libcxx/include/memory (revision d3dfd8ce)
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> 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);                          // [[nodiscard]] in C++20
87    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint); // [[nodiscard]] in C++20
88
89    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept;
90
91    template <class T, class... Args>
92        static void construct(allocator_type& a, T* p, Args&&... args);
93
94    template <class T>
95        static void destroy(allocator_type& a, T* p);
96
97    static size_type max_size(const allocator_type& a); // noexcept in C++14
98
99    static allocator_type
100        select_on_container_copy_construction(const allocator_type& a);
101};
102
103template <>
104class allocator<void> // deprecated in C++17, removed in C++20
105{
106public:
107    typedef void*                                 pointer;
108    typedef const void*                           const_pointer;
109    typedef void                                  value_type;
110
111    template <class _Up> struct rebind {typedef allocator<_Up> other;};
112};
113
114template <class T>
115class allocator
116{
117public:
118    typedef size_t    size_type;                         // deprecated in C++17, removed in C++20
119    typedef ptrdiff_t difference_type;                   // deprecated in C++17, removed in C++20
120    typedef T*        pointer;                           // deprecated in C++17, removed in C++20
121    typedef const T*  const_pointer;                     // deprecated in C++17, removed in C++20
122    typedef typename add_lvalue_reference<T>::type
123                      reference;                         // deprecated in C++17, removed in C++20
124    typedef typename add_lvalue_reference<const T>::type
125                      const_reference;                   // deprecated in C++17, removed in C++20
126
127    typedef T         value_type;
128
129    template <class U> struct rebind {typedef allocator<U> other;}; // deprecated in C++17, removed in C++20
130
131    typedef true_type propagate_on_container_move_assignment;
132    typedef true_type is_always_equal;
133
134    constexpr allocator() noexcept;                      // constexpr in C++20
135    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
136    template <class U>
137      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
138    ~allocator();
139    pointer address(reference x) const noexcept;             // deprecated in C++17, removed in C++20
140    const_pointer address(const_reference x) const noexcept; // deprecated in C++17, removed in C++20
141    T* allocate(size_t n, const void* hint);          // deprecated in C++17, removed in C++20
142    T* allocate(size_t n);
143    void deallocate(T* p, size_t n) noexcept;
144    size_type max_size() const noexcept;              // deprecated in C++17, removed in C++20
145    template<class U, class... Args>
146        void construct(U* p, Args&&... args);         // deprecated in C++17, removed in C++20
147    template <class U>
148        void destroy(U* p);                           // deprecated in C++17, removed in C++20
149};
150
151template <class T, class U>
152bool operator==(const allocator<T>&, const allocator<U>&) noexcept;
153
154template <class T, class U>
155bool operator!=(const allocator<T>&, const allocator<U>&) noexcept;
156
157template <class OutputIterator, class T>
158class raw_storage_iterator
159    : public iterator<output_iterator_tag,
160                      T,                               // purposefully not C++03
161                      ptrdiff_t,                       // purposefully not C++03
162                      T*,                              // purposefully not C++03
163                      raw_storage_iterator&>           // purposefully not C++03
164{
165public:
166    explicit raw_storage_iterator(OutputIterator x);
167    raw_storage_iterator& operator*();
168    raw_storage_iterator& operator=(const T& element);
169    raw_storage_iterator& operator++();
170    raw_storage_iterator  operator++(int);
171};
172
173template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
174template <class T> void               return_temporary_buffer(T* p) noexcept;
175
176template <class T> T* addressof(T& r) noexcept;
177template <class T> T* addressof(const T&& r) noexcept = delete;
178
179template <class InputIterator, class ForwardIterator>
180ForwardIterator
181uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
182
183template <class InputIterator, class Size, class ForwardIterator>
184ForwardIterator
185uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
186
187template <class ForwardIterator, class T>
188void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
189
190template <class ForwardIterator, class Size, class T>
191ForwardIterator
192uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
193
194template <class T>
195void destroy_at(T* location);
196
197template <class ForwardIterator>
198 void destroy(ForwardIterator first, ForwardIterator last);
199
200template <class ForwardIterator, class Size>
201 ForwardIterator destroy_n(ForwardIterator first, Size n);
202
203template <class InputIterator, class ForwardIterator>
204 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
205
206template <class InputIterator, class Size, class ForwardIterator>
207 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
208
209template <class ForwardIterator>
210 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
211
212template <class ForwardIterator, class Size>
213 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
214
215template <class ForwardIterator>
216 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
217
218template <class ForwardIterator, class Size>
219 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
220
221template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
222
223template<class X>
224class auto_ptr                                  // deprecated in C++11, removed in C++17
225{
226public:
227    typedef X element_type;
228
229    explicit auto_ptr(X* p =0) throw();
230    auto_ptr(auto_ptr&) throw();
231    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
232    auto_ptr& operator=(auto_ptr&) throw();
233    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
234    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
235    ~auto_ptr() throw();
236
237    typename add_lvalue_reference<X>::type operator*() const throw();
238    X* operator->() const throw();
239    X* get() const throw();
240    X* release() throw();
241    void reset(X* p =0) throw();
242
243    auto_ptr(auto_ptr_ref<X>) throw();
244    template<class Y> operator auto_ptr_ref<Y>() throw();
245    template<class Y> operator auto_ptr<Y>() throw();
246};
247
248template <class T>
249struct default_delete
250{
251    constexpr default_delete() noexcept = default;
252    template <class U> default_delete(const default_delete<U>&) noexcept;
253
254    void operator()(T*) const noexcept;
255};
256
257template <class T>
258struct default_delete<T[]>
259{
260    constexpr default_delete() noexcept = default;
261    void operator()(T*) const noexcept;
262    template <class U> void operator()(U*) const = delete;
263};
264
265template <class T, class D = default_delete<T>>
266class unique_ptr
267{
268public:
269    typedef see below pointer;
270    typedef T element_type;
271    typedef D deleter_type;
272
273    // constructors
274    constexpr unique_ptr() noexcept;
275    explicit unique_ptr(pointer p) noexcept;
276    unique_ptr(pointer p, see below d1) noexcept;
277    unique_ptr(pointer p, see below d2) noexcept;
278    unique_ptr(unique_ptr&& u) noexcept;
279    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
280    template <class U, class E>
281        unique_ptr(unique_ptr<U, E>&& u) noexcept;
282    template <class U>
283        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
284
285    // destructor
286    ~unique_ptr();
287
288    // assignment
289    unique_ptr& operator=(unique_ptr&& u) noexcept;
290    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
291    unique_ptr& operator=(nullptr_t) noexcept;
292
293    // observers
294    typename add_lvalue_reference<T>::type operator*() const;
295    pointer operator->() const noexcept;
296    pointer get() const noexcept;
297    deleter_type& get_deleter() noexcept;
298    const deleter_type& get_deleter() const noexcept;
299    explicit operator bool() const noexcept;
300
301    // modifiers
302    pointer release() noexcept;
303    void reset(pointer p = pointer()) noexcept;
304    void swap(unique_ptr& u) noexcept;
305};
306
307template <class T, class D>
308class unique_ptr<T[], D>
309{
310public:
311    typedef implementation-defined pointer;
312    typedef T element_type;
313    typedef D deleter_type;
314
315    // constructors
316    constexpr unique_ptr() noexcept;
317    explicit unique_ptr(pointer p) noexcept;
318    unique_ptr(pointer p, see below d) noexcept;
319    unique_ptr(pointer p, see below d) noexcept;
320    unique_ptr(unique_ptr&& u) noexcept;
321    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
322
323    // destructor
324    ~unique_ptr();
325
326    // assignment
327    unique_ptr& operator=(unique_ptr&& u) noexcept;
328    unique_ptr& operator=(nullptr_t) noexcept;
329
330    // observers
331    T& operator[](size_t i) const;
332    pointer get() const noexcept;
333    deleter_type& get_deleter() noexcept;
334    const deleter_type& get_deleter() const noexcept;
335    explicit operator bool() const noexcept;
336
337    // modifiers
338    pointer release() noexcept;
339    void reset(pointer p = pointer()) noexcept;
340    void reset(nullptr_t) noexcept;
341  template <class U> void reset(U) = delete;
342    void swap(unique_ptr& u) noexcept;
343};
344
345template <class T, class D>
346    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
347
348template <class T1, class D1, class T2, class D2>
349    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
350template <class T1, class D1, class T2, class D2>
351    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
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);
360
361template <class T, class D>
362    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
363template <class T, class D>
364    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
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;
369
370template <class T, class D>
371    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
372template <class T, class D>
373    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
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);
386
387class bad_weak_ptr
388    : public std::exception
389{
390    bad_weak_ptr() noexcept;
391};
392
393template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
394template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
395template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
396
397template<class E, class T, class Y, class D>
398    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
399
400template<class T>
401class shared_ptr
402{
403public:
404    typedef T element_type;
405    typedef weak_ptr<T> weak_type; // C++17
406
407    // constructors:
408    constexpr shared_ptr() noexcept;
409    template<class Y> explicit shared_ptr(Y* p);
410    template<class Y, class D> shared_ptr(Y* p, D d);
411    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
412    template <class D> shared_ptr(nullptr_t p, D d);
413    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
414    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
415    shared_ptr(const shared_ptr& r) noexcept;
416    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
417    shared_ptr(shared_ptr&& r) noexcept;
418    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
419    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
420    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
421    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
422    shared_ptr(nullptr_t) : shared_ptr() { }
423
424    // destructor:
425    ~shared_ptr();
426
427    // assignment:
428    shared_ptr& operator=(const shared_ptr& r) noexcept;
429    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
430    shared_ptr& operator=(shared_ptr&& r) noexcept;
431    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
432    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
433    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
434
435    // modifiers:
436    void swap(shared_ptr& r) noexcept;
437    void reset() noexcept;
438    template<class Y> void reset(Y* p);
439    template<class Y, class D> void reset(Y* p, D d);
440    template<class Y, class D, class A> void reset(Y* p, D d, A a);
441
442    // observers:
443    T* get() const noexcept;
444    T& operator*() const noexcept;
445    T* operator->() const noexcept;
446    long use_count() const noexcept;
447    bool unique() const noexcept;
448    explicit operator bool() const noexcept;
449    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
450    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
451};
452
453template<class T>
454shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
455template<class T, class D>
456shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
457
458// shared_ptr comparisons:
459template<class T, class U>
460    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
461template<class T, class U>
462    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
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;
471
472template <class T>
473    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
474template <class T>
475    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
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>
483bool 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>
487    bool 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;
496
497// shared_ptr specialized algorithms:
498template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
499
500// shared_ptr casts:
501template<class T, class U>
502    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
503template<class T, class U>
504    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
505template<class T, class U>
506    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
507
508// shared_ptr I/O:
509template<class E, class T, class Y>
510    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
511
512// shared_ptr get_deleter:
513template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
514
515template<class T, class... Args>
516    shared_ptr<T> make_shared(Args&&... args);
517template<class T, class A, class... Args>
518    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
519
520template<class T>
521class weak_ptr
522{
523public:
524    typedef T element_type;
525
526    // constructors
527    constexpr weak_ptr() noexcept;
528    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
529    weak_ptr(weak_ptr const& r) noexcept;
530    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
531    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
532    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
533
534    // destructor
535    ~weak_ptr();
536
537    // assignment
538    weak_ptr& operator=(weak_ptr const& r) noexcept;
539    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
540    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
541    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
542    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
543
544    // modifiers
545    void swap(weak_ptr& r) noexcept;
546    void reset() noexcept;
547
548    // observers
549    long use_count() const noexcept;
550    bool expired() const noexcept;
551    shared_ptr<T> lock() const noexcept;
552    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
553    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
554};
555
556template<class T>
557weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
558
559// weak_ptr specialized algorithms:
560template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
561
562// class owner_less:
563template<class T> struct owner_less;
564
565template<class T>
566struct owner_less<shared_ptr<T> >
567    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
568{
569    typedef bool result_type;
570    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
571    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
572    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
573};
574
575template<class T>
576struct owner_less<weak_ptr<T> >
577    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
578{
579    typedef bool result_type;
580    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
581    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
582    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
583};
584
585template <>  // Added in C++14
586struct owner_less<void>
587{
588    template <class _Tp, class _Up>
589    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
590    template <class _Tp, class _Up>
591    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
592    template <class _Tp, class _Up>
593    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
594    template <class _Tp, class _Up>
595    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
596
597    typedef void is_transparent;
598};
599
600template<class T>
601class enable_shared_from_this
602{
603protected:
604    constexpr enable_shared_from_this() noexcept;
605    enable_shared_from_this(enable_shared_from_this const&) noexcept;
606    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
607    ~enable_shared_from_this();
608public:
609    shared_ptr<T> shared_from_this();
610    shared_ptr<T const> shared_from_this() const;
611};
612
613template<class T>
614    bool atomic_is_lock_free(const shared_ptr<T>* p);
615template<class T>
616    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
617template<class T>
618    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
619template<class T>
620    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
621template<class T>
622    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
623template<class T>
624    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
625template<class T>
626    shared_ptr<T>
627    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
628template<class T>
629    bool
630    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
631template<class T>
632    bool
633    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
634template<class T>
635    bool
636    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
637                                          shared_ptr<T> w, memory_order success,
638                                          memory_order failure);
639template<class T>
640    bool
641    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
642                                            shared_ptr<T> w, memory_order success,
643                                            memory_order failure);
644// Hash support
645template <class T> struct hash;
646template <class T, class D> struct hash<unique_ptr<T, D> >;
647template <class T> struct hash<shared_ptr<T> >;
648
649template <class T, class Alloc>
650  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
651
652// Pointer safety
653enum class pointer_safety { relaxed, preferred, strict };
654void declare_reachable(void *p);
655template <class T> T *undeclare_reachable(T *p);
656void declare_no_pointers(char *p, size_t n);
657void undeclare_no_pointers(char *p, size_t n);
658pointer_safety get_pointer_safety() noexcept;
659
660void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
661
662}  // std
663
664*/
665
666#include <__config>
667#include <type_traits>
668#include <typeinfo>
669#include <cstddef>
670#include <cstdint>
671#include <new>
672#include <utility>
673#include <limits>
674#include <iterator>
675#include <__functional_base>
676#include <iosfwd>
677#include <tuple>
678#include <stdexcept>
679#include <cstring>
680#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
681#  include <atomic>
682#endif
683#include <version>
684
685#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
686#pragma GCC system_header
687#endif
688
689_LIBCPP_PUSH_MACROS
690#include <__undef_macros>
691
692
693_LIBCPP_BEGIN_NAMESPACE_STD
694
695template <class _ValueType>
696inline _LIBCPP_INLINE_VISIBILITY
697_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
698#if !defined(_LIBCPP_HAS_NO_THREADS) && \
699    defined(__ATOMIC_RELAXED) &&        \
700    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
701    return __atomic_load_n(__value, __ATOMIC_RELAXED);
702#else
703    return *__value;
704#endif
705}
706
707template <class _ValueType>
708inline _LIBCPP_INLINE_VISIBILITY
709_ValueType __libcpp_acquire_load(_ValueType const* __value) {
710#if !defined(_LIBCPP_HAS_NO_THREADS) && \
711    defined(__ATOMIC_ACQUIRE) &&        \
712    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
713    return __atomic_load_n(__value, __ATOMIC_ACQUIRE);
714#else
715    return *__value;
716#endif
717}
718
719// addressof moved to <type_traits>
720
721template <class _Tp> class allocator;
722
723#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
724template <>
725class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 allocator<void>
726{
727public:
728    typedef void*             pointer;
729    typedef const void*       const_pointer;
730    typedef void              value_type;
731
732    template <class _Up> struct rebind {typedef allocator<_Up> other;};
733};
734
735template <>
736class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 allocator<const void>
737{
738public:
739    typedef const void*       pointer;
740    typedef const void*       const_pointer;
741    typedef const void        value_type;
742
743    template <class _Up> struct rebind {typedef allocator<_Up> other;};
744};
745#endif
746
747// pointer_traits
748
749template <class _Tp, class = void>
750struct __has_element_type : false_type {};
751
752template <class _Tp>
753struct __has_element_type<_Tp,
754              typename __void_t<typename _Tp::element_type>::type> : true_type {};
755
756template <class _Ptr, bool = __has_element_type<_Ptr>::value>
757struct __pointer_traits_element_type;
758
759template <class _Ptr>
760struct __pointer_traits_element_type<_Ptr, true>
761{
762    typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::element_type type;
763};
764
765#ifndef _LIBCPP_HAS_NO_VARIADICS
766
767template <template <class, class...> class _Sp, class _Tp, class ..._Args>
768struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
769{
770    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::element_type type;
771};
772
773template <template <class, class...> class _Sp, class _Tp, class ..._Args>
774struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
775{
776    typedef _LIBCPP_NODEBUG_TYPE _Tp type;
777};
778
779#else  // _LIBCPP_HAS_NO_VARIADICS
780
781template <template <class> class _Sp, class _Tp>
782struct __pointer_traits_element_type<_Sp<_Tp>, true>
783{
784    typedef typename _Sp<_Tp>::element_type type;
785};
786
787template <template <class> class _Sp, class _Tp>
788struct __pointer_traits_element_type<_Sp<_Tp>, false>
789{
790    typedef _Tp type;
791};
792
793template <template <class, class> class _Sp, class _Tp, class _A0>
794struct __pointer_traits_element_type<_Sp<_Tp, _A0>, true>
795{
796    typedef typename _Sp<_Tp, _A0>::element_type type;
797};
798
799template <template <class, class> class _Sp, class _Tp, class _A0>
800struct __pointer_traits_element_type<_Sp<_Tp, _A0>, false>
801{
802    typedef _Tp type;
803};
804
805template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
806struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, true>
807{
808    typedef typename _Sp<_Tp, _A0, _A1>::element_type type;
809};
810
811template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
812struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, false>
813{
814    typedef _Tp type;
815};
816
817template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
818                                                           class _A1, class _A2>
819struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, true>
820{
821    typedef typename _Sp<_Tp, _A0, _A1, _A2>::element_type type;
822};
823
824template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
825                                                           class _A1, class _A2>
826struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, false>
827{
828    typedef _Tp type;
829};
830
831#endif  // _LIBCPP_HAS_NO_VARIADICS
832
833template <class _Tp, class = void>
834struct __has_difference_type : false_type {};
835
836template <class _Tp>
837struct __has_difference_type<_Tp,
838            typename __void_t<typename _Tp::difference_type>::type> : true_type {};
839
840template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
841struct __pointer_traits_difference_type
842{
843    typedef _LIBCPP_NODEBUG_TYPE ptrdiff_t type;
844};
845
846template <class _Ptr>
847struct __pointer_traits_difference_type<_Ptr, true>
848{
849    typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::difference_type type;
850};
851
852template <class _Tp, class _Up>
853struct __has_rebind
854{
855private:
856    struct __two {char __lx; char __lxx;};
857    template <class _Xp> static __two __test(...);
858    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
859    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
860    _LIBCPP_SUPPRESS_DEPRECATED_POP
861public:
862    static const bool value = sizeof(__test<_Tp>(0)) == 1;
863};
864
865template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
866struct __pointer_traits_rebind
867{
868#ifndef _LIBCPP_CXX03_LANG
869    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up> type;
870#else
871    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up>::other type;
872#endif
873};
874
875#ifndef _LIBCPP_HAS_NO_VARIADICS
876
877template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
878struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
879{
880#ifndef _LIBCPP_CXX03_LANG
881    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
882#else
883    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
884#endif
885};
886
887template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
888struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
889{
890    typedef _Sp<_Up, _Args...> type;
891};
892
893#else  // _LIBCPP_HAS_NO_VARIADICS
894
895template <template <class> class _Sp, class _Tp, class _Up>
896struct __pointer_traits_rebind<_Sp<_Tp>, _Up, true>
897{
898#ifndef _LIBCPP_CXX03_LANG
899    typedef typename _Sp<_Tp>::template rebind<_Up> type;
900#else
901    typedef typename _Sp<_Tp>::template rebind<_Up>::other type;
902#endif
903};
904
905template <template <class> class _Sp, class _Tp, class _Up>
906struct __pointer_traits_rebind<_Sp<_Tp>, _Up, false>
907{
908    typedef _Sp<_Up> type;
909};
910
911template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
912struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, true>
913{
914#ifndef _LIBCPP_CXX03_LANG
915    typedef typename _Sp<_Tp, _A0>::template rebind<_Up> type;
916#else
917    typedef typename _Sp<_Tp, _A0>::template rebind<_Up>::other type;
918#endif
919};
920
921template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
922struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, false>
923{
924    typedef _Sp<_Up, _A0> type;
925};
926
927template <template <class, class, class> class _Sp, class _Tp, class _A0,
928                                         class _A1, class _Up>
929struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, true>
930{
931#ifndef _LIBCPP_CXX03_LANG
932    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up> type;
933#else
934    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up>::other type;
935#endif
936};
937
938template <template <class, class, class> class _Sp, class _Tp, class _A0,
939                                         class _A1, class _Up>
940struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, false>
941{
942    typedef _Sp<_Up, _A0, _A1> type;
943};
944
945template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
946                                                class _A1, class _A2, class _Up>
947struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, true>
948{
949#ifndef _LIBCPP_CXX03_LANG
950    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up> type;
951#else
952    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
953#endif
954};
955
956template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
957                                                class _A1, class _A2, class _Up>
958struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, false>
959{
960    typedef _Sp<_Up, _A0, _A1, _A2> type;
961};
962
963#endif  // _LIBCPP_HAS_NO_VARIADICS
964
965template <class _Ptr>
966struct _LIBCPP_TEMPLATE_VIS pointer_traits
967{
968    typedef _Ptr                                                     pointer;
969    typedef typename __pointer_traits_element_type<pointer>::type    element_type;
970    typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
971
972#ifndef _LIBCPP_CXX03_LANG
973    template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
974#else
975    template <class _Up> struct rebind
976        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
977#endif  // _LIBCPP_CXX03_LANG
978
979private:
980    struct __nat {};
981public:
982    _LIBCPP_INLINE_VISIBILITY
983    static pointer pointer_to(typename conditional<is_void<element_type>::value,
984                                           __nat, element_type>::type& __r)
985        {return pointer::pointer_to(__r);}
986};
987
988template <class _Tp>
989struct _LIBCPP_TEMPLATE_VIS pointer_traits<_Tp*>
990{
991    typedef _Tp*      pointer;
992    typedef _Tp       element_type;
993    typedef ptrdiff_t difference_type;
994
995#ifndef _LIBCPP_CXX03_LANG
996    template <class _Up> using rebind = _Up*;
997#else
998    template <class _Up> struct rebind {typedef _Up* other;};
999#endif
1000
1001private:
1002    struct __nat {};
1003public:
1004    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1005    static pointer pointer_to(typename conditional<is_void<element_type>::value,
1006                                      __nat, element_type>::type& __r) _NOEXCEPT
1007        {return _VSTD::addressof(__r);}
1008};
1009
1010template <class _From, class _To>
1011struct __rebind_pointer {
1012#ifndef _LIBCPP_CXX03_LANG
1013    typedef typename pointer_traits<_From>::template rebind<_To>        type;
1014#else
1015    typedef typename pointer_traits<_From>::template rebind<_To>::other type;
1016#endif
1017};
1018
1019// allocator_traits
1020
1021template <class _Tp, class = void>
1022struct __has_pointer_type : false_type {};
1023
1024template <class _Tp>
1025struct __has_pointer_type<_Tp,
1026          typename __void_t<typename _Tp::pointer>::type> : true_type {};
1027
1028namespace __pointer_type_imp
1029{
1030
1031template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
1032struct __pointer_type
1033{
1034    typedef _LIBCPP_NODEBUG_TYPE typename _Dp::pointer type;
1035};
1036
1037template <class _Tp, class _Dp>
1038struct __pointer_type<_Tp, _Dp, false>
1039{
1040    typedef _LIBCPP_NODEBUG_TYPE _Tp* type;
1041};
1042
1043}  // __pointer_type_imp
1044
1045template <class _Tp, class _Dp>
1046struct __pointer_type
1047{
1048    typedef _LIBCPP_NODEBUG_TYPE typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
1049};
1050
1051template <class _Tp, class = void>
1052struct __has_const_pointer : false_type {};
1053
1054template <class _Tp>
1055struct __has_const_pointer<_Tp,
1056            typename __void_t<typename _Tp::const_pointer>::type> : true_type {};
1057
1058template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
1059struct __const_pointer
1060{
1061    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::const_pointer type;
1062};
1063
1064template <class _Tp, class _Ptr, class _Alloc>
1065struct __const_pointer<_Tp, _Ptr, _Alloc, false>
1066{
1067#ifndef _LIBCPP_CXX03_LANG
1068    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
1069#else
1070    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
1071#endif
1072};
1073
1074template <class _Tp, class = void>
1075struct __has_void_pointer : false_type {};
1076
1077template <class _Tp>
1078struct __has_void_pointer<_Tp,
1079               typename __void_t<typename _Tp::void_pointer>::type> : true_type {};
1080
1081template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
1082struct __void_pointer
1083{
1084    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::void_pointer type;
1085};
1086
1087template <class _Ptr, class _Alloc>
1088struct __void_pointer<_Ptr, _Alloc, false>
1089{
1090#ifndef _LIBCPP_CXX03_LANG
1091    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<void> type;
1092#else
1093    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<void>::other type;
1094#endif
1095};
1096
1097template <class _Tp, class = void>
1098struct __has_const_void_pointer : false_type {};
1099
1100template <class _Tp>
1101struct __has_const_void_pointer<_Tp,
1102            typename __void_t<typename _Tp::const_void_pointer>::type> : true_type {};
1103
1104template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
1105struct __const_void_pointer
1106{
1107    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::const_void_pointer type;
1108};
1109
1110template <class _Ptr, class _Alloc>
1111struct __const_void_pointer<_Ptr, _Alloc, false>
1112{
1113#ifndef _LIBCPP_CXX03_LANG
1114    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const void> type;
1115#else
1116    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const void>::other type;
1117#endif
1118};
1119
1120
1121template <bool _UsePointerTraits> struct __to_address_helper;
1122
1123template <> struct __to_address_helper<true> {
1124    template <class _Pointer>
1125    using __return_type = decltype(pointer_traits<_Pointer>::to_address(std::declval<const _Pointer&>()));
1126
1127    template <class _Pointer>
1128    _LIBCPP_CONSTEXPR
1129    static __return_type<_Pointer>
1130    __do_it(const _Pointer &__p) _NOEXCEPT { return pointer_traits<_Pointer>::to_address(__p); }
1131};
1132
1133template <class _Pointer, bool _Dummy = true>
1134using __choose_to_address = __to_address_helper<_IsValidExpansion<__to_address_helper<_Dummy>::template __return_type, _Pointer>::value>;
1135
1136
1137template <class _Tp>
1138inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1139_Tp*
1140__to_address(_Tp* __p) _NOEXCEPT
1141{
1142    static_assert(!is_function<_Tp>::value, "_Tp is a function type");
1143    return __p;
1144}
1145
1146template <class _Pointer>
1147inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1148typename __choose_to_address<_Pointer>::template __return_type<_Pointer>
1149__to_address(const _Pointer& __p) _NOEXCEPT {
1150  return __choose_to_address<_Pointer>::__do_it(__p);
1151}
1152
1153template <> struct __to_address_helper<false> {
1154    template <class _Pointer>
1155    using __return_type = typename pointer_traits<_Pointer>::element_type*;
1156
1157    template <class _Pointer>
1158    _LIBCPP_CONSTEXPR
1159    static __return_type<_Pointer>
1160    __do_it(const _Pointer &__p) _NOEXCEPT { return std::__to_address(__p.operator->()); }
1161};
1162
1163
1164#if _LIBCPP_STD_VER > 17
1165template <class _Tp>
1166inline _LIBCPP_INLINE_VISIBILITY constexpr
1167_Tp*
1168to_address(_Tp* __p) _NOEXCEPT
1169{
1170    static_assert(!is_function_v<_Tp>, "_Tp is a function type");
1171    return __p;
1172}
1173
1174template <class _Pointer>
1175inline _LIBCPP_INLINE_VISIBILITY
1176auto
1177to_address(const _Pointer& __p) _NOEXCEPT
1178{
1179    return _VSTD::__to_address(__p);
1180}
1181#endif
1182
1183template <class _Tp, class = void>
1184struct __has_size_type : false_type {};
1185
1186template <class _Tp>
1187struct __has_size_type<_Tp,
1188               typename __void_t<typename _Tp::size_type>::type> : true_type {};
1189
1190template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
1191struct __size_type
1192{
1193    typedef _LIBCPP_NODEBUG_TYPE typename make_unsigned<_DiffType>::type type;
1194};
1195
1196template <class _Alloc, class _DiffType>
1197struct __size_type<_Alloc, _DiffType, true>
1198{
1199    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::size_type type;
1200};
1201
1202template <class _Tp, class = void>
1203struct __has_propagate_on_container_copy_assignment : false_type {};
1204
1205template <class _Tp>
1206struct __has_propagate_on_container_copy_assignment<_Tp,
1207    typename __void_t<typename _Tp::propagate_on_container_copy_assignment>::type>
1208        : true_type {};
1209
1210template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
1211struct __propagate_on_container_copy_assignment
1212{
1213    typedef _LIBCPP_NODEBUG_TYPE false_type type;
1214};
1215
1216template <class _Alloc>
1217struct __propagate_on_container_copy_assignment<_Alloc, true>
1218{
1219    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_copy_assignment type;
1220};
1221
1222template <class _Tp, class = void>
1223struct __has_propagate_on_container_move_assignment : false_type {};
1224
1225template <class _Tp>
1226struct __has_propagate_on_container_move_assignment<_Tp,
1227           typename __void_t<typename _Tp::propagate_on_container_move_assignment>::type>
1228               : true_type {};
1229
1230template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
1231struct __propagate_on_container_move_assignment
1232{
1233    typedef false_type type;
1234};
1235
1236template <class _Alloc>
1237struct __propagate_on_container_move_assignment<_Alloc, true>
1238{
1239    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_move_assignment type;
1240};
1241
1242template <class _Tp, class = void>
1243struct __has_propagate_on_container_swap : false_type {};
1244
1245template <class _Tp>
1246struct __has_propagate_on_container_swap<_Tp,
1247           typename __void_t<typename _Tp::propagate_on_container_swap>::type>
1248               : true_type {};
1249
1250template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
1251struct __propagate_on_container_swap
1252{
1253    typedef false_type type;
1254};
1255
1256template <class _Alloc>
1257struct __propagate_on_container_swap<_Alloc, true>
1258{
1259    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_swap type;
1260};
1261
1262template <class _Tp, class = void>
1263struct __has_is_always_equal : false_type {};
1264
1265template <class _Tp>
1266struct __has_is_always_equal<_Tp,
1267           typename __void_t<typename _Tp::is_always_equal>::type>
1268               : true_type {};
1269
1270template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
1271struct __is_always_equal
1272{
1273    typedef _LIBCPP_NODEBUG_TYPE typename _VSTD::is_empty<_Alloc>::type type;
1274};
1275
1276template <class _Alloc>
1277struct __is_always_equal<_Alloc, true>
1278{
1279    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::is_always_equal type;
1280};
1281
1282template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
1283struct __has_rebind_other
1284{
1285private:
1286    struct __two {char __lx; char __lxx;};
1287    template <class _Xp> static __two __test(...);
1288    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1289    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
1290    _LIBCPP_SUPPRESS_DEPRECATED_POP
1291public:
1292    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1293};
1294
1295template <class _Tp, class _Up>
1296struct __has_rebind_other<_Tp, _Up, false>
1297{
1298    static const bool value = false;
1299};
1300
1301template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
1302struct __allocator_traits_rebind
1303{
1304    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1305    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up>::other type;
1306    _LIBCPP_SUPPRESS_DEPRECATED_POP
1307};
1308
1309template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1310struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
1311{
1312    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1313    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
1314    _LIBCPP_SUPPRESS_DEPRECATED_POP
1315};
1316
1317template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1318struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
1319{
1320    typedef _LIBCPP_NODEBUG_TYPE _Alloc<_Up, _Args...> type;
1321};
1322
1323#ifndef _LIBCPP_CXX03_LANG
1324
1325_LIBCPP_SUPPRESS_DEPRECATED_PUSH
1326template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1327auto
1328__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1329    -> decltype((void)__a.allocate(__sz, __p), true_type());
1330_LIBCPP_SUPPRESS_DEPRECATED_POP
1331
1332template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1333auto
1334__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1335    -> false_type;
1336
1337template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1338struct __has_allocate_hint
1339    : decltype(_VSTD::__has_allocate_hint_test(declval<_Alloc>(),
1340                                               declval<_SizeType>(),
1341                                               declval<_ConstVoidPtr>()))
1342{
1343};
1344
1345#else  // _LIBCPP_CXX03_LANG
1346
1347template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1348struct __has_allocate_hint
1349    : true_type
1350{
1351};
1352
1353#endif  // _LIBCPP_CXX03_LANG
1354
1355_LIBCPP_SUPPRESS_DEPRECATED_PUSH
1356template <class _Alloc, class ..._Args,
1357    class = decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Args>()...))>
1358static true_type __test_has_construct(int);
1359_LIBCPP_SUPPRESS_DEPRECATED_POP
1360
1361template <class _Alloc, class...>
1362static false_type __test_has_construct(...);
1363
1364template <class _Alloc, class ..._Args>
1365struct __has_construct : decltype(__test_has_construct<_Alloc, _Args...>(0)) {};
1366
1367#if !defined(_LIBCPP_CXX03_LANG)
1368
1369_LIBCPP_SUPPRESS_DEPRECATED_PUSH
1370template <class _Alloc, class _Pointer>
1371auto
1372__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
1373    -> decltype(__a.destroy(__p), true_type());
1374_LIBCPP_SUPPRESS_DEPRECATED_POP
1375
1376template <class _Alloc, class _Pointer>
1377auto
1378__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
1379    -> false_type;
1380
1381template <class _Alloc, class _Pointer>
1382struct __has_destroy
1383    : decltype(_VSTD::__has_destroy_test(declval<_Alloc>(),
1384                                         declval<_Pointer>()))
1385{
1386};
1387
1388_LIBCPP_SUPPRESS_DEPRECATED_PUSH
1389template <class _Alloc>
1390auto
1391__has_max_size_test(_Alloc&& __a)
1392    -> decltype(__a.max_size(), true_type());
1393_LIBCPP_SUPPRESS_DEPRECATED_POP
1394
1395template <class _Alloc>
1396auto
1397__has_max_size_test(const volatile _Alloc& __a)
1398    -> false_type;
1399
1400template <class _Alloc>
1401struct __has_max_size
1402    : decltype(_VSTD::__has_max_size_test(declval<_Alloc&>()))
1403{
1404};
1405
1406template <class _Alloc>
1407auto
1408__has_select_on_container_copy_construction_test(_Alloc&& __a)
1409    -> decltype(__a.select_on_container_copy_construction(), true_type());
1410
1411template <class _Alloc>
1412auto
1413__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
1414    -> false_type;
1415
1416template <class _Alloc>
1417struct __has_select_on_container_copy_construction
1418    : decltype(_VSTD::__has_select_on_container_copy_construction_test(declval<_Alloc&>()))
1419{
1420};
1421
1422#else  // _LIBCPP_CXX03_LANG
1423
1424template <class _Alloc, class _Pointer, class = void>
1425struct __has_destroy : false_type {};
1426
1427template <class _Alloc, class _Pointer>
1428struct __has_destroy<_Alloc, _Pointer, typename __void_t<
1429    decltype(_VSTD::declval<_Alloc>().destroy(_VSTD::declval<_Pointer>()))
1430>::type> : std::true_type {};
1431
1432template <class _Alloc>
1433struct __has_max_size
1434    : true_type
1435{
1436};
1437
1438template <class _Alloc>
1439struct __has_select_on_container_copy_construction
1440    : false_type
1441{
1442};
1443
1444#endif  // _LIBCPP_CXX03_LANG
1445
1446template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
1447struct __alloc_traits_difference_type
1448{
1449    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::difference_type type;
1450};
1451
1452template <class _Alloc, class _Ptr>
1453struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
1454{
1455    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::difference_type type;
1456};
1457
1458template <class _Tp>
1459struct __is_default_allocator : false_type {};
1460
1461template <class _Tp>
1462struct __is_default_allocator<_VSTD::allocator<_Tp> > : true_type {};
1463
1464
1465
1466template <class _Alloc,
1467    bool = __has_construct<_Alloc, typename _Alloc::value_type*,  typename _Alloc::value_type&&>::value && !__is_default_allocator<_Alloc>::value
1468    >
1469struct __is_cpp17_move_insertable;
1470template <class _Alloc>
1471struct __is_cpp17_move_insertable<_Alloc, true> : std::true_type {};
1472template <class _Alloc>
1473struct __is_cpp17_move_insertable<_Alloc, false> : std::is_move_constructible<typename _Alloc::value_type> {};
1474
1475template <class _Alloc,
1476    bool = __has_construct<_Alloc, typename _Alloc::value_type*, const typename _Alloc::value_type&>::value && !__is_default_allocator<_Alloc>::value
1477    >
1478struct __is_cpp17_copy_insertable;
1479template <class _Alloc>
1480struct __is_cpp17_copy_insertable<_Alloc, true> : __is_cpp17_move_insertable<_Alloc> {};
1481template <class _Alloc>
1482struct __is_cpp17_copy_insertable<_Alloc, false> : integral_constant<bool,
1483    std::is_copy_constructible<typename _Alloc::value_type>::value &&
1484    __is_cpp17_move_insertable<_Alloc>::value>
1485  {};
1486
1487
1488
1489template <class _Alloc>
1490struct _LIBCPP_TEMPLATE_VIS allocator_traits
1491{
1492    typedef _Alloc                              allocator_type;
1493    typedef typename allocator_type::value_type value_type;
1494
1495    typedef typename __pointer_type<value_type, allocator_type>::type pointer;
1496    typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
1497    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
1498    typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;
1499
1500    typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
1501    typedef typename __size_type<allocator_type, difference_type>::type size_type;
1502
1503    typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
1504                     propagate_on_container_copy_assignment;
1505    typedef typename __propagate_on_container_move_assignment<allocator_type>::type
1506                     propagate_on_container_move_assignment;
1507    typedef typename __propagate_on_container_swap<allocator_type>::type
1508                     propagate_on_container_swap;
1509    typedef typename __is_always_equal<allocator_type>::type
1510                     is_always_equal;
1511
1512#ifndef _LIBCPP_CXX03_LANG
1513    template <class _Tp> using rebind_alloc =
1514                  typename __allocator_traits_rebind<allocator_type, _Tp>::type;
1515    template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp> >;
1516#else  // _LIBCPP_CXX03_LANG
1517    template <class _Tp> struct rebind_alloc
1518        {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
1519    template <class _Tp> struct rebind_traits
1520        {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
1521#endif  // _LIBCPP_CXX03_LANG
1522
1523    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1524    static pointer allocate(allocator_type& __a, size_type __n)
1525        {return __a.allocate(__n);}
1526    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1527    static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
1528        {return __allocate(__a, __n, __hint,
1529            __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}
1530
1531    _LIBCPP_INLINE_VISIBILITY
1532    static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
1533        {__a.deallocate(__p, __n);}
1534
1535    template <class _Tp, class... _Args>
1536        _LIBCPP_INLINE_VISIBILITY
1537        static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
1538            {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
1539                         __a, __p, _VSTD::forward<_Args>(__args)...);}
1540
1541    template <class _Tp>
1542        _LIBCPP_INLINE_VISIBILITY
1543        static void destroy(allocator_type& __a, _Tp* __p)
1544            {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}
1545
1546    _LIBCPP_INLINE_VISIBILITY
1547    static size_type max_size(const allocator_type& __a) _NOEXCEPT
1548        {return __max_size(__has_max_size<const allocator_type>(), __a);}
1549
1550    _LIBCPP_INLINE_VISIBILITY
1551    static allocator_type
1552        select_on_container_copy_construction(const allocator_type& __a)
1553            {return __select_on_container_copy_construction(
1554                __has_select_on_container_copy_construction<const allocator_type>(),
1555                __a);}
1556
1557    template <class _Ptr>
1558        _LIBCPP_INLINE_VISIBILITY
1559        static
1560        void
1561        __construct_forward_with_exception_guarantees(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
1562        {
1563            static_assert(__is_cpp17_move_insertable<allocator_type>::value,
1564              "The specified type does not meet the requirements of Cpp17MoveInsertible");
1565            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1566              construct(__a, _VSTD::__to_address(__begin2),
1567#ifdef _LIBCPP_NO_EXCEPTIONS
1568                        _VSTD::move(*__begin1)
1569#else
1570                        _VSTD::move_if_noexcept(*__begin1)
1571#endif
1572                        );
1573        }
1574
1575    template <class _Tp>
1576        _LIBCPP_INLINE_VISIBILITY
1577        static
1578        typename enable_if
1579        <
1580            (__is_default_allocator<allocator_type>::value
1581                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1582             is_trivially_move_constructible<_Tp>::value,
1583            void
1584        >::type
1585        __construct_forward_with_exception_guarantees(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
1586        {
1587            ptrdiff_t _Np = __end1 - __begin1;
1588            if (_Np > 0)
1589            {
1590                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
1591                __begin2 += _Np;
1592            }
1593        }
1594
1595    template <class _Iter, class _Ptr>
1596        _LIBCPP_INLINE_VISIBILITY
1597        static
1598        void
1599        __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
1600        {
1601            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1602                construct(__a, _VSTD::__to_address(__begin2), *__begin1);
1603        }
1604
1605    template <class _SourceTp, class _DestTp,
1606              class _RawSourceTp = typename remove_const<_SourceTp>::type,
1607              class _RawDestTp = typename remove_const<_DestTp>::type>
1608        _LIBCPP_INLINE_VISIBILITY
1609        static
1610        typename enable_if
1611        <
1612            is_trivially_copy_constructible<_DestTp>::value &&
1613            is_same<_RawSourceTp, _RawDestTp>::value &&
1614            (__is_default_allocator<allocator_type>::value ||
1615             !__has_construct<allocator_type, _DestTp*, _SourceTp&>::value),
1616            void
1617        >::type
1618        __construct_range_forward(allocator_type&, _SourceTp* __begin1, _SourceTp* __end1, _DestTp*& __begin2)
1619        {
1620            ptrdiff_t _Np = __end1 - __begin1;
1621            if (_Np > 0)
1622            {
1623                _VSTD::memcpy(const_cast<_RawDestTp*>(__begin2), __begin1, _Np * sizeof(_DestTp));
1624                __begin2 += _Np;
1625            }
1626        }
1627
1628    template <class _Ptr>
1629        _LIBCPP_INLINE_VISIBILITY
1630        static
1631        void
1632        __construct_backward_with_exception_guarantees(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
1633        {
1634            static_assert(__is_cpp17_move_insertable<allocator_type>::value,
1635              "The specified type does not meet the requirements of Cpp17MoveInsertable");
1636            while (__end1 != __begin1)
1637            {
1638              construct(__a, _VSTD::__to_address(__end2 - 1),
1639#ifdef _LIBCPP_NO_EXCEPTIONS
1640                        _VSTD::move(*--__end1)
1641#else
1642                        _VSTD::move_if_noexcept(*--__end1)
1643#endif
1644                        );
1645              --__end2;
1646            }
1647        }
1648
1649    template <class _Tp>
1650        _LIBCPP_INLINE_VISIBILITY
1651        static
1652        typename enable_if
1653        <
1654            (__is_default_allocator<allocator_type>::value
1655                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1656             is_trivially_move_constructible<_Tp>::value,
1657            void
1658        >::type
1659        __construct_backward_with_exception_guarantees(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
1660        {
1661            ptrdiff_t _Np = __end1 - __begin1;
1662            __end2 -= _Np;
1663            if (_Np > 0)
1664                _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
1665        }
1666
1667private:
1668
1669    _LIBCPP_INLINE_VISIBILITY
1670    static pointer __allocate(allocator_type& __a, size_type __n,
1671        const_void_pointer __hint, true_type)
1672        {
1673            _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1674            return __a.allocate(__n, __hint);
1675            _LIBCPP_SUPPRESS_DEPRECATED_POP
1676        }
1677    _LIBCPP_INLINE_VISIBILITY
1678    static pointer __allocate(allocator_type& __a, size_type __n,
1679        const_void_pointer, false_type)
1680        {return __a.allocate(__n);}
1681
1682    template <class _Tp, class... _Args>
1683        _LIBCPP_INLINE_VISIBILITY
1684        static void __construct(true_type, allocator_type& __a, _Tp* __p, _Args&&... __args)
1685            {
1686                _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1687                __a.construct(__p, _VSTD::forward<_Args>(__args)...);
1688                _LIBCPP_SUPPRESS_DEPRECATED_POP
1689            }
1690
1691    template <class _Tp, class... _Args>
1692        _LIBCPP_INLINE_VISIBILITY
1693        static void __construct(false_type, allocator_type&, _Tp* __p, _Args&&... __args)
1694            {
1695                ::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
1696            }
1697
1698    template <class _Tp>
1699        _LIBCPP_INLINE_VISIBILITY
1700        static void __destroy(true_type, allocator_type& __a, _Tp* __p)
1701            {
1702                _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1703                __a.destroy(__p);
1704                _LIBCPP_SUPPRESS_DEPRECATED_POP
1705            }
1706    template <class _Tp>
1707        _LIBCPP_INLINE_VISIBILITY
1708        static void __destroy(false_type, allocator_type&, _Tp* __p)
1709            {
1710                __p->~_Tp();
1711            }
1712
1713    _LIBCPP_INLINE_VISIBILITY
1714    static size_type __max_size(true_type, const allocator_type& __a) _NOEXCEPT
1715            {
1716                _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1717                return __a.max_size();
1718                _LIBCPP_SUPPRESS_DEPRECATED_POP
1719            }
1720
1721    _LIBCPP_INLINE_VISIBILITY
1722    static size_type __max_size(false_type, const allocator_type&) _NOEXCEPT
1723            {return numeric_limits<size_type>::max() / sizeof(value_type);}
1724
1725    _LIBCPP_INLINE_VISIBILITY
1726    static allocator_type
1727        __select_on_container_copy_construction(true_type, const allocator_type& __a)
1728            {return __a.select_on_container_copy_construction();}
1729    _LIBCPP_INLINE_VISIBILITY
1730    static allocator_type
1731        __select_on_container_copy_construction(false_type, const allocator_type& __a)
1732            {return __a;}
1733};
1734
1735template <class _Traits, class _Tp>
1736struct __rebind_alloc_helper
1737{
1738#ifndef _LIBCPP_CXX03_LANG
1739    typedef _LIBCPP_NODEBUG_TYPE typename _Traits::template rebind_alloc<_Tp>        type;
1740#else
1741    typedef typename _Traits::template rebind_alloc<_Tp>::other type;
1742#endif
1743};
1744
1745// allocator
1746
1747template <class _Tp>
1748class _LIBCPP_TEMPLATE_VIS allocator
1749{
1750public:
1751#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1752    _LIBCPP_DEPRECATED_IN_CXX17 typedef size_t     size_type;
1753    _LIBCPP_DEPRECATED_IN_CXX17 typedef ptrdiff_t  difference_type;
1754    _LIBCPP_DEPRECATED_IN_CXX17 typedef _Tp*       pointer;
1755    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp* const_pointer;
1756    _LIBCPP_DEPRECATED_IN_CXX17 typedef _Tp&       reference;
1757    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp& const_reference;
1758
1759    template <class _Up> struct _LIBCPP_DEPRECATED_IN_CXX17 rebind {typedef allocator<_Up> other;};
1760#endif
1761
1762    typedef _Tp value_type;
1763
1764    typedef true_type propagate_on_container_move_assignment;
1765    typedef true_type is_always_equal;
1766
1767    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1768    allocator() _NOEXCEPT {}
1769
1770    template <class _Up>
1771    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1772    allocator(const allocator<_Up>&) _NOEXCEPT {}
1773
1774#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1775    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1776    pointer address(reference __x) const _NOEXCEPT
1777        {return _VSTD::addressof(__x);}
1778    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1779    const_pointer address(const_reference __x) const _NOEXCEPT
1780        {return _VSTD::addressof(__x);}
1781#endif
1782
1783    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _Tp* allocate(size_t __n)
1784        {
1785        // TODO(mpark): Replace with `allocator_traits<allocator>::max_size(*this)`.
1786        if (__n > (size_t(~0) / sizeof(_Tp)))
1787            __throw_length_error("allocator<T>::allocate(size_t n)"
1788                                 " 'n' exceeds maximum supported size");
1789        return static_cast<_Tp*>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1790        }
1791
1792#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1793    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_DEPRECATED_IN_CXX17
1794    _Tp* allocate(size_t __n, const void*) { return allocate(__n); }
1795#endif
1796
1797    _LIBCPP_INLINE_VISIBILITY void deallocate(_Tp* __p, size_t __n) _NOEXCEPT
1798        {_VSTD::__libcpp_deallocate((void*)__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
1799
1800#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1801    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1802        {return size_type(~0) / sizeof(_Tp);}
1803
1804    template <class _Up, class... _Args>
1805        _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1806        void
1807        construct(_Up* __p, _Args&&... __args)
1808        {
1809            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1810        }
1811    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1812#endif
1813};
1814
1815template <class _Tp>
1816class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
1817{
1818public:
1819#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1820    _LIBCPP_DEPRECATED_IN_CXX17 typedef size_t     size_type;
1821    _LIBCPP_DEPRECATED_IN_CXX17 typedef ptrdiff_t  difference_type;
1822    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp* pointer;
1823    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp* const_pointer;
1824    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp& reference;
1825    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp& const_reference;
1826
1827    template <class _Up> struct _LIBCPP_DEPRECATED_IN_CXX17 rebind {typedef allocator<_Up> other;};
1828#endif
1829
1830    typedef const _Tp value_type;
1831
1832    typedef true_type propagate_on_container_move_assignment;
1833    typedef true_type is_always_equal;
1834
1835    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1836    allocator() _NOEXCEPT {}
1837
1838    template <class _Up>
1839    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1840    allocator(const allocator<_Up>&) _NOEXCEPT {}
1841
1842#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1843    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1844    const_pointer address(const_reference __x) const _NOEXCEPT
1845        {return _VSTD::addressof(__x);}
1846#endif
1847
1848    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY const _Tp* allocate(size_t __n)
1849    {
1850        // TODO(mpark): Replace with `allocator_traits<allocator>::max_size(*this)`.
1851        if (__n > (size_t(~0) / sizeof(_Tp)))
1852            __throw_length_error("allocator<const T>::allocate(size_t n)"
1853                                 " 'n' exceeds maximum supported size");
1854        return static_cast<const _Tp*>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1855    }
1856
1857#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1858    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_DEPRECATED_IN_CXX17
1859    const _Tp* allocate(size_t __n, const void*) { return allocate(__n); }
1860#endif
1861
1862    _LIBCPP_INLINE_VISIBILITY void deallocate(const _Tp* __p, size_t __n)
1863        {_VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
1864
1865#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1866    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1867        {return size_type(~0) / sizeof(_Tp);}
1868
1869#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1870    template <class _Up, class... _Args>
1871        _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1872        void
1873        construct(_Up* __p, _Args&&... __args)
1874        {
1875            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1876        }
1877#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1878        _LIBCPP_INLINE_VISIBILITY
1879        void
1880        construct(pointer __p)
1881        {
1882            ::new((void*) const_cast<_Tp *>(__p)) _Tp();
1883        }
1884# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1885
1886    template <class _A0>
1887        _LIBCPP_INLINE_VISIBILITY
1888        void
1889        construct(pointer __p, _A0& __a0)
1890        {
1891            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
1892        }
1893    template <class _A0>
1894        _LIBCPP_INLINE_VISIBILITY
1895        void
1896        construct(pointer __p, const _A0& __a0)
1897        {
1898            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
1899        }
1900# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1901    template <class _A0, class _A1>
1902        _LIBCPP_INLINE_VISIBILITY
1903        void
1904        construct(pointer __p, _A0& __a0, _A1& __a1)
1905        {
1906            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1907        }
1908    template <class _A0, class _A1>
1909        _LIBCPP_INLINE_VISIBILITY
1910        void
1911        construct(pointer __p, const _A0& __a0, _A1& __a1)
1912        {
1913            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1914        }
1915    template <class _A0, class _A1>
1916        _LIBCPP_INLINE_VISIBILITY
1917        void
1918        construct(pointer __p, _A0& __a0, const _A1& __a1)
1919        {
1920            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1921        }
1922    template <class _A0, class _A1>
1923        _LIBCPP_INLINE_VISIBILITY
1924        void
1925        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1926        {
1927            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1928        }
1929#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1930    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1931#endif
1932};
1933
1934template <class _Tp, class _Up>
1935inline _LIBCPP_INLINE_VISIBILITY
1936bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
1937
1938template <class _Tp, class _Up>
1939inline _LIBCPP_INLINE_VISIBILITY
1940bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
1941
1942template <class _OutputIterator, class _Tp>
1943class _LIBCPP_TEMPLATE_VIS raw_storage_iterator
1944    : public iterator<output_iterator_tag,
1945                      _Tp,                                         // purposefully not C++03
1946                      ptrdiff_t,                                   // purposefully not C++03
1947                      _Tp*,                                        // purposefully not C++03
1948                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
1949{
1950private:
1951    _OutputIterator __x_;
1952public:
1953    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
1954    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
1955    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
1956        {::new(_VSTD::addressof(*__x_)) _Tp(__element); return *this;}
1957#if _LIBCPP_STD_VER >= 14
1958    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
1959        {::new(_VSTD::addressof(*__x_)) _Tp(_VSTD::move(__element)); return *this;}
1960#endif
1961    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
1962    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
1963        {raw_storage_iterator __t(*this); ++__x_; return __t;}
1964#if _LIBCPP_STD_VER >= 14
1965    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
1966#endif
1967};
1968
1969template <class _Tp>
1970_LIBCPP_NODISCARD_EXT _LIBCPP_NO_CFI
1971pair<_Tp*, ptrdiff_t>
1972get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
1973{
1974    pair<_Tp*, ptrdiff_t> __r(0, 0);
1975    const ptrdiff_t __m = (~ptrdiff_t(0) ^
1976                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
1977                           / sizeof(_Tp);
1978    if (__n > __m)
1979        __n = __m;
1980    while (__n > 0)
1981    {
1982#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
1983    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
1984        {
1985            std::align_val_t __al =
1986                std::align_val_t(std::alignment_of<_Tp>::value);
1987            __r.first = static_cast<_Tp*>(::operator new(
1988                __n * sizeof(_Tp), __al, nothrow));
1989        } else {
1990            __r.first = static_cast<_Tp*>(::operator new(
1991                __n * sizeof(_Tp), nothrow));
1992        }
1993#else
1994    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
1995        {
1996            // Since aligned operator new is unavailable, return an empty
1997            // buffer rather than one with invalid alignment.
1998            return __r;
1999        }
2000
2001        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
2002#endif
2003
2004        if (__r.first)
2005        {
2006            __r.second = __n;
2007            break;
2008        }
2009        __n /= 2;
2010    }
2011    return __r;
2012}
2013
2014template <class _Tp>
2015inline _LIBCPP_INLINE_VISIBILITY
2016void return_temporary_buffer(_Tp* __p) _NOEXCEPT
2017{
2018  _VSTD::__libcpp_deallocate_unsized((void*)__p, _LIBCPP_ALIGNOF(_Tp));
2019}
2020
2021#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2022template <class _Tp>
2023struct _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr_ref
2024{
2025    _Tp* __ptr_;
2026};
2027
2028template<class _Tp>
2029class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr
2030{
2031private:
2032    _Tp* __ptr_;
2033public:
2034    typedef _Tp element_type;
2035
2036    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) _NOEXCEPT : __ptr_(__p) {}
2037    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) _NOEXCEPT : __ptr_(__p.release()) {}
2038    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) _NOEXCEPT
2039        : __ptr_(__p.release()) {}
2040    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) _NOEXCEPT
2041        {reset(__p.release()); return *this;}
2042    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) _NOEXCEPT
2043        {reset(__p.release()); return *this;}
2044    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) _NOEXCEPT
2045        {reset(__p.__ptr_); return *this;}
2046    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() _NOEXCEPT {delete __ptr_;}
2047
2048    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const _NOEXCEPT
2049        {return *__ptr_;}
2050    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const _NOEXCEPT {return __ptr_;}
2051    _LIBCPP_INLINE_VISIBILITY _Tp* get() const _NOEXCEPT {return __ptr_;}
2052    _LIBCPP_INLINE_VISIBILITY _Tp* release() _NOEXCEPT
2053    {
2054        _Tp* __t = __ptr_;
2055        __ptr_ = 0;
2056        return __t;
2057    }
2058    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) _NOEXCEPT
2059    {
2060        if (__ptr_ != __p)
2061            delete __ptr_;
2062        __ptr_ = __p;
2063    }
2064
2065    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) _NOEXCEPT : __ptr_(__p.__ptr_) {}
2066    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() _NOEXCEPT
2067        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
2068    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() _NOEXCEPT
2069        {return auto_ptr<_Up>(release());}
2070};
2071
2072template <>
2073class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr<void>
2074{
2075public:
2076    typedef void element_type;
2077};
2078#endif
2079
2080// Tag used to default initialize one or both of the pair's elements.
2081struct __default_init_tag {};
2082struct __value_init_tag {};
2083
2084template <class _Tp, int _Idx,
2085          bool _CanBeEmptyBase =
2086              is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value>
2087struct __compressed_pair_elem {
2088  typedef _Tp _ParamT;
2089  typedef _Tp& reference;
2090  typedef const _Tp& const_reference;
2091
2092  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2093  __compressed_pair_elem(__default_init_tag) {}
2094  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2095  __compressed_pair_elem(__value_init_tag) : __value_() {}
2096
2097  template <class _Up, class = typename enable_if<
2098      !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2099  >::type>
2100  _LIBCPP_INLINE_VISIBILITY
2101  _LIBCPP_CONSTEXPR explicit
2102  __compressed_pair_elem(_Up&& __u)
2103      : __value_(_VSTD::forward<_Up>(__u))
2104    {
2105    }
2106
2107
2108#ifndef _LIBCPP_CXX03_LANG
2109  template <class... _Args, size_t... _Indexes>
2110  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2111  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2112                         __tuple_indices<_Indexes...>)
2113      : __value_(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2114#endif
2115
2116
2117  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return __value_; }
2118  _LIBCPP_INLINE_VISIBILITY
2119  const_reference __get() const _NOEXCEPT { return __value_; }
2120
2121private:
2122  _Tp __value_;
2123};
2124
2125template <class _Tp, int _Idx>
2126struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp {
2127  typedef _Tp _ParamT;
2128  typedef _Tp& reference;
2129  typedef const _Tp& const_reference;
2130  typedef _Tp __value_type;
2131
2132  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR __compressed_pair_elem() = default;
2133  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2134  __compressed_pair_elem(__default_init_tag) {}
2135  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2136  __compressed_pair_elem(__value_init_tag) : __value_type() {}
2137
2138  template <class _Up, class = typename enable_if<
2139        !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2140  >::type>
2141  _LIBCPP_INLINE_VISIBILITY
2142  _LIBCPP_CONSTEXPR explicit
2143  __compressed_pair_elem(_Up&& __u)
2144      : __value_type(_VSTD::forward<_Up>(__u))
2145  {}
2146
2147#ifndef _LIBCPP_CXX03_LANG
2148  template <class... _Args, size_t... _Indexes>
2149  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2150  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2151                         __tuple_indices<_Indexes...>)
2152      : __value_type(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2153#endif
2154
2155  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return *this; }
2156  _LIBCPP_INLINE_VISIBILITY
2157  const_reference __get() const _NOEXCEPT { return *this; }
2158};
2159
2160template <class _T1, class _T2>
2161class __compressed_pair : private __compressed_pair_elem<_T1, 0>,
2162                          private __compressed_pair_elem<_T2, 1> {
2163  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T1, 0> _Base1;
2164  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T2, 1> _Base2;
2165
2166  // NOTE: This static assert should never fire because __compressed_pair
2167  // is *almost never* used in a scenario where it's possible for T1 == T2.
2168  // (The exception is std::function where it is possible that the function
2169  //  object and the allocator have the same type).
2170  static_assert((!is_same<_T1, _T2>::value),
2171    "__compressed_pair cannot be instantated when T1 and T2 are the same type; "
2172    "The current implementation is NOT ABI-compatible with the previous "
2173    "implementation for this configuration");
2174
2175public:
2176    template <bool _Dummy = true,
2177      class = typename enable_if<
2178          __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
2179          __dependent_type<is_default_constructible<_T2>, _Dummy>::value
2180      >::type
2181  >
2182  _LIBCPP_INLINE_VISIBILITY
2183  _LIBCPP_CONSTEXPR __compressed_pair() : _Base1(__value_init_tag()), _Base2(__value_init_tag()) {}
2184
2185  template <class _U1, class _U2>
2186  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2187  __compressed_pair(_U1&& __t1, _U2&& __t2)
2188      : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {}
2189
2190#ifndef _LIBCPP_CXX03_LANG
2191  template <class... _Args1, class... _Args2>
2192  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2193  __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
2194                    tuple<_Args2...> __second_args)
2195      : _Base1(__pc, _VSTD::move(__first_args),
2196               typename __make_tuple_indices<sizeof...(_Args1)>::type()),
2197        _Base2(__pc, _VSTD::move(__second_args),
2198               typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}
2199#endif
2200
2201  _LIBCPP_INLINE_VISIBILITY
2202  typename _Base1::reference first() _NOEXCEPT {
2203    return static_cast<_Base1&>(*this).__get();
2204  }
2205
2206  _LIBCPP_INLINE_VISIBILITY
2207  typename _Base1::const_reference first() const _NOEXCEPT {
2208    return static_cast<_Base1 const&>(*this).__get();
2209  }
2210
2211  _LIBCPP_INLINE_VISIBILITY
2212  typename _Base2::reference second() _NOEXCEPT {
2213    return static_cast<_Base2&>(*this).__get();
2214  }
2215
2216  _LIBCPP_INLINE_VISIBILITY
2217  typename _Base2::const_reference second() const _NOEXCEPT {
2218    return static_cast<_Base2 const&>(*this).__get();
2219  }
2220
2221  _LIBCPP_INLINE_VISIBILITY
2222  void swap(__compressed_pair& __x)
2223    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2224               __is_nothrow_swappable<_T2>::value)
2225  {
2226    using std::swap;
2227    swap(first(), __x.first());
2228    swap(second(), __x.second());
2229  }
2230};
2231
2232template <class _T1, class _T2>
2233inline _LIBCPP_INLINE_VISIBILITY
2234void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
2235    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2236               __is_nothrow_swappable<_T2>::value) {
2237  __x.swap(__y);
2238}
2239
2240// default_delete
2241
2242template <class _Tp>
2243struct _LIBCPP_TEMPLATE_VIS default_delete {
2244    static_assert(!is_function<_Tp>::value,
2245                  "default_delete cannot be instantiated for function types");
2246#ifndef _LIBCPP_CXX03_LANG
2247  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2248#else
2249  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2250#endif
2251  template <class _Up>
2252  _LIBCPP_INLINE_VISIBILITY
2253  default_delete(const default_delete<_Up>&,
2254                 typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* =
2255                     0) _NOEXCEPT {}
2256
2257  _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __ptr) const _NOEXCEPT {
2258    static_assert(sizeof(_Tp) > 0,
2259                  "default_delete can not delete incomplete type");
2260    static_assert(!is_void<_Tp>::value,
2261                  "default_delete can not delete incomplete type");
2262    delete __ptr;
2263  }
2264};
2265
2266template <class _Tp>
2267struct _LIBCPP_TEMPLATE_VIS default_delete<_Tp[]> {
2268private:
2269  template <class _Up>
2270  struct _EnableIfConvertible
2271      : enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value> {};
2272
2273public:
2274#ifndef _LIBCPP_CXX03_LANG
2275  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2276#else
2277  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2278#endif
2279
2280  template <class _Up>
2281  _LIBCPP_INLINE_VISIBILITY
2282  default_delete(const default_delete<_Up[]>&,
2283                 typename _EnableIfConvertible<_Up>::type* = 0) _NOEXCEPT {}
2284
2285  template <class _Up>
2286  _LIBCPP_INLINE_VISIBILITY
2287  typename _EnableIfConvertible<_Up>::type
2288  operator()(_Up* __ptr) const _NOEXCEPT {
2289    static_assert(sizeof(_Tp) > 0,
2290                  "default_delete can not delete incomplete type");
2291    static_assert(!is_void<_Tp>::value,
2292                  "default_delete can not delete void type");
2293    delete[] __ptr;
2294  }
2295};
2296
2297template <class _Deleter>
2298struct __unique_ptr_deleter_sfinae {
2299  static_assert(!is_reference<_Deleter>::value, "incorrect specialization");
2300  typedef const _Deleter& __lval_ref_type;
2301  typedef _Deleter&& __good_rval_ref_type;
2302  typedef true_type __enable_rval_overload;
2303};
2304
2305template <class _Deleter>
2306struct __unique_ptr_deleter_sfinae<_Deleter const&> {
2307  typedef const _Deleter& __lval_ref_type;
2308  typedef const _Deleter&& __bad_rval_ref_type;
2309  typedef false_type __enable_rval_overload;
2310};
2311
2312template <class _Deleter>
2313struct __unique_ptr_deleter_sfinae<_Deleter&> {
2314  typedef _Deleter& __lval_ref_type;
2315  typedef _Deleter&& __bad_rval_ref_type;
2316  typedef false_type __enable_rval_overload;
2317};
2318
2319#if defined(_LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI)
2320#  define _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI __attribute__((trivial_abi))
2321#else
2322#  define _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI
2323#endif
2324
2325template <class _Tp, class _Dp = default_delete<_Tp> >
2326class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS unique_ptr {
2327public:
2328  typedef _Tp element_type;
2329  typedef _Dp deleter_type;
2330  typedef _LIBCPP_NODEBUG_TYPE typename __pointer_type<_Tp, deleter_type>::type pointer;
2331
2332  static_assert(!is_rvalue_reference<deleter_type>::value,
2333                "the specified deleter type cannot be an rvalue reference");
2334
2335private:
2336  __compressed_pair<pointer, deleter_type> __ptr_;
2337
2338  struct __nat { int __for_bool_; };
2339
2340  typedef _LIBCPP_NODEBUG_TYPE __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2341
2342  template <bool _Dummy>
2343  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2344      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2345
2346  template <bool _Dummy>
2347  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2348      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2349
2350  template <bool _Dummy>
2351  using _BadRValRefType _LIBCPP_NODEBUG_TYPE  =
2352      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2353
2354  template <bool _Dummy, class _Deleter = typename __dependent_type<
2355                             __identity<deleter_type>, _Dummy>::type>
2356  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE =
2357      typename enable_if<is_default_constructible<_Deleter>::value &&
2358                         !is_pointer<_Deleter>::value>::type;
2359
2360  template <class _ArgType>
2361  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2362      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2363
2364  template <class _UPtr, class _Up>
2365  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2366      is_convertible<typename _UPtr::pointer, pointer>::value &&
2367      !is_array<_Up>::value
2368  >::type;
2369
2370  template <class _UDel>
2371  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2372      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2373      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2374    >::type;
2375
2376  template <class _UDel>
2377  using _EnableIfDeleterAssignable = typename enable_if<
2378      is_assignable<_Dp&, _UDel&&>::value
2379    >::type;
2380
2381public:
2382  template <bool _Dummy = true,
2383            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2384  _LIBCPP_INLINE_VISIBILITY
2385  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2386
2387  template <bool _Dummy = true,
2388            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2389  _LIBCPP_INLINE_VISIBILITY
2390  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2391
2392  template <bool _Dummy = true,
2393            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2394  _LIBCPP_INLINE_VISIBILITY
2395  explicit unique_ptr(pointer __p) _NOEXCEPT : __ptr_(__p, __default_init_tag()) {}
2396
2397  template <bool _Dummy = true,
2398            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2399  _LIBCPP_INLINE_VISIBILITY
2400  unique_ptr(pointer __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2401      : __ptr_(__p, __d) {}
2402
2403  template <bool _Dummy = true,
2404            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2405  _LIBCPP_INLINE_VISIBILITY
2406  unique_ptr(pointer __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2407      : __ptr_(__p, _VSTD::move(__d)) {
2408    static_assert(!is_reference<deleter_type>::value,
2409                  "rvalue deleter bound to reference");
2410  }
2411
2412  template <bool _Dummy = true,
2413            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> > >
2414  _LIBCPP_INLINE_VISIBILITY
2415  unique_ptr(pointer __p, _BadRValRefType<_Dummy> __d) = delete;
2416
2417  _LIBCPP_INLINE_VISIBILITY
2418  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2419      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2420  }
2421
2422  template <class _Up, class _Ep,
2423      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2424      class = _EnableIfDeleterConvertible<_Ep>
2425  >
2426  _LIBCPP_INLINE_VISIBILITY
2427  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2428      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
2429
2430#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2431  template <class _Up>
2432  _LIBCPP_INLINE_VISIBILITY
2433  unique_ptr(auto_ptr<_Up>&& __p,
2434             typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2435                                    is_same<_Dp, default_delete<_Tp> >::value,
2436                                __nat>::type = __nat()) _NOEXCEPT
2437      : __ptr_(__p.release(), __default_init_tag()) {}
2438#endif
2439
2440  _LIBCPP_INLINE_VISIBILITY
2441  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2442    reset(__u.release());
2443    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2444    return *this;
2445  }
2446
2447  template <class _Up, class _Ep,
2448      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2449      class = _EnableIfDeleterAssignable<_Ep>
2450  >
2451  _LIBCPP_INLINE_VISIBILITY
2452  unique_ptr& operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2453    reset(__u.release());
2454    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2455    return *this;
2456  }
2457
2458#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2459  template <class _Up>
2460  _LIBCPP_INLINE_VISIBILITY
2461      typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2462                             is_same<_Dp, default_delete<_Tp> >::value,
2463                         unique_ptr&>::type
2464      operator=(auto_ptr<_Up> __p) {
2465    reset(__p.release());
2466    return *this;
2467  }
2468#endif
2469
2470#ifdef _LIBCPP_CXX03_LANG
2471  unique_ptr(unique_ptr const&) = delete;
2472  unique_ptr& operator=(unique_ptr const&) = delete;
2473#endif
2474
2475
2476  _LIBCPP_INLINE_VISIBILITY
2477  ~unique_ptr() { reset(); }
2478
2479  _LIBCPP_INLINE_VISIBILITY
2480  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2481    reset();
2482    return *this;
2483  }
2484
2485  _LIBCPP_INLINE_VISIBILITY
2486  typename add_lvalue_reference<_Tp>::type
2487  operator*() const {
2488    return *__ptr_.first();
2489  }
2490  _LIBCPP_INLINE_VISIBILITY
2491  pointer operator->() const _NOEXCEPT {
2492    return __ptr_.first();
2493  }
2494  _LIBCPP_INLINE_VISIBILITY
2495  pointer get() const _NOEXCEPT {
2496    return __ptr_.first();
2497  }
2498  _LIBCPP_INLINE_VISIBILITY
2499  deleter_type& get_deleter() _NOEXCEPT {
2500    return __ptr_.second();
2501  }
2502  _LIBCPP_INLINE_VISIBILITY
2503  const deleter_type& get_deleter() const _NOEXCEPT {
2504    return __ptr_.second();
2505  }
2506  _LIBCPP_INLINE_VISIBILITY
2507  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2508    return __ptr_.first() != nullptr;
2509  }
2510
2511  _LIBCPP_INLINE_VISIBILITY
2512  pointer release() _NOEXCEPT {
2513    pointer __t = __ptr_.first();
2514    __ptr_.first() = pointer();
2515    return __t;
2516  }
2517
2518  _LIBCPP_INLINE_VISIBILITY
2519  void reset(pointer __p = pointer()) _NOEXCEPT {
2520    pointer __tmp = __ptr_.first();
2521    __ptr_.first() = __p;
2522    if (__tmp)
2523      __ptr_.second()(__tmp);
2524  }
2525
2526  _LIBCPP_INLINE_VISIBILITY
2527  void swap(unique_ptr& __u) _NOEXCEPT {
2528    __ptr_.swap(__u.__ptr_);
2529  }
2530};
2531
2532
2533template <class _Tp, class _Dp>
2534class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
2535public:
2536  typedef _Tp element_type;
2537  typedef _Dp deleter_type;
2538  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2539
2540private:
2541  __compressed_pair<pointer, deleter_type> __ptr_;
2542
2543  template <class _From>
2544  struct _CheckArrayPointerConversion : is_same<_From, pointer> {};
2545
2546  template <class _FromElem>
2547  struct _CheckArrayPointerConversion<_FromElem*>
2548      : integral_constant<bool,
2549          is_same<_FromElem*, pointer>::value ||
2550            (is_same<pointer, element_type*>::value &&
2551             is_convertible<_FromElem(*)[], element_type(*)[]>::value)
2552      >
2553  {};
2554
2555  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2556
2557  template <bool _Dummy>
2558  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2559      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2560
2561  template <bool _Dummy>
2562  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2563      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2564
2565  template <bool _Dummy>
2566  using _BadRValRefType _LIBCPP_NODEBUG_TYPE =
2567      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2568
2569  template <bool _Dummy, class _Deleter = typename __dependent_type<
2570                             __identity<deleter_type>, _Dummy>::type>
2571  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE  =
2572      typename enable_if<is_default_constructible<_Deleter>::value &&
2573                         !is_pointer<_Deleter>::value>::type;
2574
2575  template <class _ArgType>
2576  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2577      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2578
2579  template <class _Pp>
2580  using _EnableIfPointerConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2581      _CheckArrayPointerConversion<_Pp>::value
2582  >::type;
2583
2584  template <class _UPtr, class _Up,
2585        class _ElemT = typename _UPtr::element_type>
2586  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2587      is_array<_Up>::value &&
2588      is_same<pointer, element_type*>::value &&
2589      is_same<typename _UPtr::pointer, _ElemT*>::value &&
2590      is_convertible<_ElemT(*)[], element_type(*)[]>::value
2591    >::type;
2592
2593  template <class _UDel>
2594  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2595      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2596      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2597    >::type;
2598
2599  template <class _UDel>
2600  using _EnableIfDeleterAssignable _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2601      is_assignable<_Dp&, _UDel&&>::value
2602    >::type;
2603
2604public:
2605  template <bool _Dummy = true,
2606            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2607  _LIBCPP_INLINE_VISIBILITY
2608  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2609
2610  template <bool _Dummy = true,
2611            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2612  _LIBCPP_INLINE_VISIBILITY
2613  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2614
2615  template <class _Pp, bool _Dummy = true,
2616            class = _EnableIfDeleterDefaultConstructible<_Dummy>,
2617            class = _EnableIfPointerConvertible<_Pp> >
2618  _LIBCPP_INLINE_VISIBILITY
2619  explicit unique_ptr(_Pp __p) _NOEXCEPT
2620      : __ptr_(__p, __default_init_tag()) {}
2621
2622  template <class _Pp, bool _Dummy = true,
2623            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> >,
2624            class = _EnableIfPointerConvertible<_Pp> >
2625  _LIBCPP_INLINE_VISIBILITY
2626  unique_ptr(_Pp __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2627      : __ptr_(__p, __d) {}
2628
2629  template <bool _Dummy = true,
2630            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2631  _LIBCPP_INLINE_VISIBILITY
2632  unique_ptr(nullptr_t, _LValRefType<_Dummy> __d) _NOEXCEPT
2633      : __ptr_(nullptr, __d) {}
2634
2635  template <class _Pp, bool _Dummy = true,
2636            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> >,
2637            class = _EnableIfPointerConvertible<_Pp> >
2638  _LIBCPP_INLINE_VISIBILITY
2639  unique_ptr(_Pp __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2640      : __ptr_(__p, _VSTD::move(__d)) {
2641    static_assert(!is_reference<deleter_type>::value,
2642                  "rvalue deleter bound to reference");
2643  }
2644
2645  template <bool _Dummy = true,
2646            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2647  _LIBCPP_INLINE_VISIBILITY
2648  unique_ptr(nullptr_t, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2649      : __ptr_(nullptr, _VSTD::move(__d)) {
2650    static_assert(!is_reference<deleter_type>::value,
2651                  "rvalue deleter bound to reference");
2652  }
2653
2654  template <class _Pp, bool _Dummy = true,
2655            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> >,
2656            class = _EnableIfPointerConvertible<_Pp> >
2657  _LIBCPP_INLINE_VISIBILITY
2658  unique_ptr(_Pp __p, _BadRValRefType<_Dummy> __d) = delete;
2659
2660  _LIBCPP_INLINE_VISIBILITY
2661  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2662      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2663  }
2664
2665  _LIBCPP_INLINE_VISIBILITY
2666  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2667    reset(__u.release());
2668    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2669    return *this;
2670  }
2671
2672  template <class _Up, class _Ep,
2673      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2674      class = _EnableIfDeleterConvertible<_Ep>
2675  >
2676  _LIBCPP_INLINE_VISIBILITY
2677  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2678      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {
2679  }
2680
2681  template <class _Up, class _Ep,
2682      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2683      class = _EnableIfDeleterAssignable<_Ep>
2684  >
2685  _LIBCPP_INLINE_VISIBILITY
2686  unique_ptr&
2687  operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2688    reset(__u.release());
2689    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2690    return *this;
2691  }
2692
2693#ifdef _LIBCPP_CXX03_LANG
2694  unique_ptr(unique_ptr const&) = delete;
2695  unique_ptr& operator=(unique_ptr const&) = delete;
2696#endif
2697
2698public:
2699  _LIBCPP_INLINE_VISIBILITY
2700  ~unique_ptr() { reset(); }
2701
2702  _LIBCPP_INLINE_VISIBILITY
2703  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2704    reset();
2705    return *this;
2706  }
2707
2708  _LIBCPP_INLINE_VISIBILITY
2709  typename add_lvalue_reference<_Tp>::type
2710  operator[](size_t __i) const {
2711    return __ptr_.first()[__i];
2712  }
2713  _LIBCPP_INLINE_VISIBILITY
2714  pointer get() const _NOEXCEPT {
2715    return __ptr_.first();
2716  }
2717
2718  _LIBCPP_INLINE_VISIBILITY
2719  deleter_type& get_deleter() _NOEXCEPT {
2720    return __ptr_.second();
2721  }
2722
2723  _LIBCPP_INLINE_VISIBILITY
2724  const deleter_type& get_deleter() const _NOEXCEPT {
2725    return __ptr_.second();
2726  }
2727  _LIBCPP_INLINE_VISIBILITY
2728  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2729    return __ptr_.first() != nullptr;
2730  }
2731
2732  _LIBCPP_INLINE_VISIBILITY
2733  pointer release() _NOEXCEPT {
2734    pointer __t = __ptr_.first();
2735    __ptr_.first() = pointer();
2736    return __t;
2737  }
2738
2739  template <class _Pp>
2740  _LIBCPP_INLINE_VISIBILITY
2741  typename enable_if<
2742      _CheckArrayPointerConversion<_Pp>::value
2743  >::type
2744  reset(_Pp __p) _NOEXCEPT {
2745    pointer __tmp = __ptr_.first();
2746    __ptr_.first() = __p;
2747    if (__tmp)
2748      __ptr_.second()(__tmp);
2749  }
2750
2751  _LIBCPP_INLINE_VISIBILITY
2752  void reset(nullptr_t = nullptr) _NOEXCEPT {
2753    pointer __tmp = __ptr_.first();
2754    __ptr_.first() = nullptr;
2755    if (__tmp)
2756      __ptr_.second()(__tmp);
2757  }
2758
2759  _LIBCPP_INLINE_VISIBILITY
2760  void swap(unique_ptr& __u) _NOEXCEPT {
2761    __ptr_.swap(__u.__ptr_);
2762  }
2763
2764};
2765
2766template <class _Tp, class _Dp>
2767inline _LIBCPP_INLINE_VISIBILITY
2768typename enable_if<
2769    __is_swappable<_Dp>::value,
2770    void
2771>::type
2772swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
2773
2774template <class _T1, class _D1, class _T2, class _D2>
2775inline _LIBCPP_INLINE_VISIBILITY
2776bool
2777operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
2778
2779template <class _T1, class _D1, class _T2, class _D2>
2780inline _LIBCPP_INLINE_VISIBILITY
2781bool
2782operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
2783
2784template <class _T1, class _D1, class _T2, class _D2>
2785inline _LIBCPP_INLINE_VISIBILITY
2786bool
2787operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
2788{
2789    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2790    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
2791    typedef typename common_type<_P1, _P2>::type _Vp;
2792    return less<_Vp>()(__x.get(), __y.get());
2793}
2794
2795template <class _T1, class _D1, class _T2, class _D2>
2796inline _LIBCPP_INLINE_VISIBILITY
2797bool
2798operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
2799
2800template <class _T1, class _D1, class _T2, class _D2>
2801inline _LIBCPP_INLINE_VISIBILITY
2802bool
2803operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
2804
2805template <class _T1, class _D1, class _T2, class _D2>
2806inline _LIBCPP_INLINE_VISIBILITY
2807bool
2808operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
2809
2810template <class _T1, class _D1>
2811inline _LIBCPP_INLINE_VISIBILITY
2812bool
2813operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2814{
2815    return !__x;
2816}
2817
2818template <class _T1, class _D1>
2819inline _LIBCPP_INLINE_VISIBILITY
2820bool
2821operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2822{
2823    return !__x;
2824}
2825
2826template <class _T1, class _D1>
2827inline _LIBCPP_INLINE_VISIBILITY
2828bool
2829operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2830{
2831    return static_cast<bool>(__x);
2832}
2833
2834template <class _T1, class _D1>
2835inline _LIBCPP_INLINE_VISIBILITY
2836bool
2837operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2838{
2839    return static_cast<bool>(__x);
2840}
2841
2842template <class _T1, class _D1>
2843inline _LIBCPP_INLINE_VISIBILITY
2844bool
2845operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2846{
2847    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2848    return less<_P1>()(__x.get(), nullptr);
2849}
2850
2851template <class _T1, class _D1>
2852inline _LIBCPP_INLINE_VISIBILITY
2853bool
2854operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2855{
2856    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2857    return less<_P1>()(nullptr, __x.get());
2858}
2859
2860template <class _T1, class _D1>
2861inline _LIBCPP_INLINE_VISIBILITY
2862bool
2863operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2864{
2865    return nullptr < __x;
2866}
2867
2868template <class _T1, class _D1>
2869inline _LIBCPP_INLINE_VISIBILITY
2870bool
2871operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2872{
2873    return __x < nullptr;
2874}
2875
2876template <class _T1, class _D1>
2877inline _LIBCPP_INLINE_VISIBILITY
2878bool
2879operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2880{
2881    return !(nullptr < __x);
2882}
2883
2884template <class _T1, class _D1>
2885inline _LIBCPP_INLINE_VISIBILITY
2886bool
2887operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2888{
2889    return !(__x < nullptr);
2890}
2891
2892template <class _T1, class _D1>
2893inline _LIBCPP_INLINE_VISIBILITY
2894bool
2895operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2896{
2897    return !(__x < nullptr);
2898}
2899
2900template <class _T1, class _D1>
2901inline _LIBCPP_INLINE_VISIBILITY
2902bool
2903operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2904{
2905    return !(nullptr < __x);
2906}
2907
2908#if _LIBCPP_STD_VER > 11
2909
2910template<class _Tp>
2911struct __unique_if
2912{
2913    typedef unique_ptr<_Tp> __unique_single;
2914};
2915
2916template<class _Tp>
2917struct __unique_if<_Tp[]>
2918{
2919    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
2920};
2921
2922template<class _Tp, size_t _Np>
2923struct __unique_if<_Tp[_Np]>
2924{
2925    typedef void __unique_array_known_bound;
2926};
2927
2928template<class _Tp, class... _Args>
2929inline _LIBCPP_INLINE_VISIBILITY
2930typename __unique_if<_Tp>::__unique_single
2931make_unique(_Args&&... __args)
2932{
2933    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
2934}
2935
2936template<class _Tp>
2937inline _LIBCPP_INLINE_VISIBILITY
2938typename __unique_if<_Tp>::__unique_array_unknown_bound
2939make_unique(size_t __n)
2940{
2941    typedef typename remove_extent<_Tp>::type _Up;
2942    return unique_ptr<_Tp>(new _Up[__n]());
2943}
2944
2945template<class _Tp, class... _Args>
2946    typename __unique_if<_Tp>::__unique_array_known_bound
2947    make_unique(_Args&&...) = delete;
2948
2949#endif  // _LIBCPP_STD_VER > 11
2950
2951template <class _Tp, class _Dp>
2952#ifdef _LIBCPP_CXX03_LANG
2953struct _LIBCPP_TEMPLATE_VIS hash<unique_ptr<_Tp, _Dp> >
2954#else
2955struct _LIBCPP_TEMPLATE_VIS hash<__enable_hash_helper<
2956    unique_ptr<_Tp, _Dp>, typename unique_ptr<_Tp, _Dp>::pointer> >
2957#endif
2958{
2959    typedef unique_ptr<_Tp, _Dp> argument_type;
2960    typedef size_t               result_type;
2961    _LIBCPP_INLINE_VISIBILITY
2962    result_type operator()(const argument_type& __ptr) const
2963    {
2964        typedef typename argument_type::pointer pointer;
2965        return hash<pointer>()(__ptr.get());
2966    }
2967};
2968
2969struct __destruct_n
2970{
2971private:
2972    size_t __size_;
2973
2974    template <class _Tp>
2975    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
2976        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
2977
2978    template <class _Tp>
2979    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
2980        {}
2981
2982    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
2983        {++__size_;}
2984    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
2985        {}
2986
2987    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
2988        {__size_ = __s;}
2989    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
2990        {}
2991public:
2992    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
2993        : __size_(__s) {}
2994
2995    template <class _Tp>
2996    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
2997        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
2998
2999    template <class _Tp>
3000    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
3001        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3002
3003    template <class _Tp>
3004    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
3005        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3006};
3007
3008template <class _Alloc>
3009class __allocator_destructor
3010{
3011    typedef _LIBCPP_NODEBUG_TYPE allocator_traits<_Alloc> __alloc_traits;
3012public:
3013    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::pointer pointer;
3014    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::size_type size_type;
3015private:
3016    _Alloc& __alloc_;
3017    size_type __s_;
3018public:
3019    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
3020             _NOEXCEPT
3021        : __alloc_(__a), __s_(__s) {}
3022    _LIBCPP_INLINE_VISIBILITY
3023    void operator()(pointer __p) _NOEXCEPT
3024        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
3025};
3026
3027template <class _InputIterator, class _ForwardIterator>
3028_ForwardIterator
3029uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
3030{
3031    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3032#ifndef _LIBCPP_NO_EXCEPTIONS
3033    _ForwardIterator __s = __r;
3034    try
3035    {
3036#endif
3037        for (; __f != __l; ++__f, (void) ++__r)
3038            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3039#ifndef _LIBCPP_NO_EXCEPTIONS
3040    }
3041    catch (...)
3042    {
3043        for (; __s != __r; ++__s)
3044            __s->~value_type();
3045        throw;
3046    }
3047#endif
3048    return __r;
3049}
3050
3051template <class _InputIterator, class _Size, class _ForwardIterator>
3052_ForwardIterator
3053uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
3054{
3055    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3056#ifndef _LIBCPP_NO_EXCEPTIONS
3057    _ForwardIterator __s = __r;
3058    try
3059    {
3060#endif
3061        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
3062            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3063#ifndef _LIBCPP_NO_EXCEPTIONS
3064    }
3065    catch (...)
3066    {
3067        for (; __s != __r; ++__s)
3068            __s->~value_type();
3069        throw;
3070    }
3071#endif
3072    return __r;
3073}
3074
3075template <class _ForwardIterator, class _Tp>
3076void
3077uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
3078{
3079    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3080#ifndef _LIBCPP_NO_EXCEPTIONS
3081    _ForwardIterator __s = __f;
3082    try
3083    {
3084#endif
3085        for (; __f != __l; ++__f)
3086            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3087#ifndef _LIBCPP_NO_EXCEPTIONS
3088    }
3089    catch (...)
3090    {
3091        for (; __s != __f; ++__s)
3092            __s->~value_type();
3093        throw;
3094    }
3095#endif
3096}
3097
3098template <class _ForwardIterator, class _Size, class _Tp>
3099_ForwardIterator
3100uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
3101{
3102    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3103#ifndef _LIBCPP_NO_EXCEPTIONS
3104    _ForwardIterator __s = __f;
3105    try
3106    {
3107#endif
3108        for (; __n > 0; ++__f, (void) --__n)
3109            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3110#ifndef _LIBCPP_NO_EXCEPTIONS
3111    }
3112    catch (...)
3113    {
3114        for (; __s != __f; ++__s)
3115            __s->~value_type();
3116        throw;
3117    }
3118#endif
3119    return __f;
3120}
3121
3122#if _LIBCPP_STD_VER > 14
3123
3124template <class _Tp>
3125inline _LIBCPP_INLINE_VISIBILITY
3126void destroy_at(_Tp* __loc) {
3127    _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
3128    __loc->~_Tp();
3129}
3130
3131template <class _ForwardIterator>
3132inline _LIBCPP_INLINE_VISIBILITY
3133void destroy(_ForwardIterator __first, _ForwardIterator __last) {
3134    for (; __first != __last; ++__first)
3135        _VSTD::destroy_at(_VSTD::addressof(*__first));
3136}
3137
3138template <class _ForwardIterator, class _Size>
3139inline _LIBCPP_INLINE_VISIBILITY
3140_ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
3141    for (; __n > 0; (void)++__first, --__n)
3142        _VSTD::destroy_at(_VSTD::addressof(*__first));
3143    return __first;
3144}
3145
3146template <class _ForwardIterator>
3147inline _LIBCPP_INLINE_VISIBILITY
3148void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
3149    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3150    auto __idx = __first;
3151#ifndef _LIBCPP_NO_EXCEPTIONS
3152    try {
3153#endif
3154    for (; __idx != __last; ++__idx)
3155        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3156#ifndef _LIBCPP_NO_EXCEPTIONS
3157    } catch (...) {
3158        _VSTD::destroy(__first, __idx);
3159        throw;
3160    }
3161#endif
3162}
3163
3164template <class _ForwardIterator, class _Size>
3165inline _LIBCPP_INLINE_VISIBILITY
3166_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
3167    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3168    auto __idx = __first;
3169#ifndef _LIBCPP_NO_EXCEPTIONS
3170    try {
3171#endif
3172    for (; __n > 0; (void)++__idx, --__n)
3173        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3174    return __idx;
3175#ifndef _LIBCPP_NO_EXCEPTIONS
3176    } catch (...) {
3177        _VSTD::destroy(__first, __idx);
3178        throw;
3179    }
3180#endif
3181}
3182
3183
3184template <class _ForwardIterator>
3185inline _LIBCPP_INLINE_VISIBILITY
3186void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
3187    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3188    auto __idx = __first;
3189#ifndef _LIBCPP_NO_EXCEPTIONS
3190    try {
3191#endif
3192    for (; __idx != __last; ++__idx)
3193        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3194#ifndef _LIBCPP_NO_EXCEPTIONS
3195    } catch (...) {
3196        _VSTD::destroy(__first, __idx);
3197        throw;
3198    }
3199#endif
3200}
3201
3202template <class _ForwardIterator, class _Size>
3203inline _LIBCPP_INLINE_VISIBILITY
3204_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
3205    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3206    auto __idx = __first;
3207#ifndef _LIBCPP_NO_EXCEPTIONS
3208    try {
3209#endif
3210    for (; __n > 0; (void)++__idx, --__n)
3211        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3212    return __idx;
3213#ifndef _LIBCPP_NO_EXCEPTIONS
3214    } catch (...) {
3215        _VSTD::destroy(__first, __idx);
3216        throw;
3217    }
3218#endif
3219}
3220
3221
3222template <class _InputIt, class _ForwardIt>
3223inline _LIBCPP_INLINE_VISIBILITY
3224_ForwardIt uninitialized_move(_InputIt __first, _InputIt __last, _ForwardIt __first_res) {
3225    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3226    auto __idx = __first_res;
3227#ifndef _LIBCPP_NO_EXCEPTIONS
3228    try {
3229#endif
3230    for (; __first != __last; (void)++__idx, ++__first)
3231        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3232    return __idx;
3233#ifndef _LIBCPP_NO_EXCEPTIONS
3234    } catch (...) {
3235        _VSTD::destroy(__first_res, __idx);
3236        throw;
3237    }
3238#endif
3239}
3240
3241template <class _InputIt, class _Size, class _ForwardIt>
3242inline _LIBCPP_INLINE_VISIBILITY
3243pair<_InputIt, _ForwardIt>
3244uninitialized_move_n(_InputIt __first, _Size __n, _ForwardIt __first_res) {
3245    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3246    auto __idx = __first_res;
3247#ifndef _LIBCPP_NO_EXCEPTIONS
3248    try {
3249#endif
3250    for (; __n > 0; ++__idx, (void)++__first, --__n)
3251        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3252    return {__first, __idx};
3253#ifndef _LIBCPP_NO_EXCEPTIONS
3254    } catch (...) {
3255        _VSTD::destroy(__first_res, __idx);
3256        throw;
3257    }
3258#endif
3259}
3260
3261
3262#endif // _LIBCPP_STD_VER > 14
3263
3264// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
3265// should be sufficient for thread safety.
3266// See https://bugs.llvm.org/show_bug.cgi?id=22803
3267#if defined(__clang__) && __has_builtin(__atomic_add_fetch)          \
3268                       && defined(__ATOMIC_RELAXED)                  \
3269                       && defined(__ATOMIC_ACQ_REL)
3270#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3271#elif defined(_LIBCPP_COMPILER_GCC)
3272#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3273#endif
3274
3275template <class _Tp>
3276inline _LIBCPP_INLINE_VISIBILITY _Tp
3277__libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT
3278{
3279#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3280    return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
3281#else
3282    return __t += 1;
3283#endif
3284}
3285
3286template <class _Tp>
3287inline _LIBCPP_INLINE_VISIBILITY _Tp
3288__libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT
3289{
3290#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3291    return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
3292#else
3293    return __t -= 1;
3294#endif
3295}
3296
3297class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
3298    : public std::exception
3299{
3300public:
3301    bad_weak_ptr() _NOEXCEPT = default;
3302    bad_weak_ptr(const bad_weak_ptr&) _NOEXCEPT = default;
3303    virtual ~bad_weak_ptr() _NOEXCEPT;
3304    virtual const char* what() const  _NOEXCEPT;
3305};
3306
3307_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
3308void __throw_bad_weak_ptr()
3309{
3310#ifndef _LIBCPP_NO_EXCEPTIONS
3311    throw bad_weak_ptr();
3312#else
3313    _VSTD::abort();
3314#endif
3315}
3316
3317template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr;
3318
3319class _LIBCPP_TYPE_VIS __shared_count
3320{
3321    __shared_count(const __shared_count&);
3322    __shared_count& operator=(const __shared_count&);
3323
3324protected:
3325    long __shared_owners_;
3326    virtual ~__shared_count();
3327private:
3328    virtual void __on_zero_shared() _NOEXCEPT = 0;
3329
3330public:
3331    _LIBCPP_INLINE_VISIBILITY
3332    explicit __shared_count(long __refs = 0) _NOEXCEPT
3333        : __shared_owners_(__refs) {}
3334
3335#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3336    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3337    void __add_shared() _NOEXCEPT;
3338    bool __release_shared() _NOEXCEPT;
3339#else
3340    _LIBCPP_INLINE_VISIBILITY
3341    void __add_shared() _NOEXCEPT {
3342      __libcpp_atomic_refcount_increment(__shared_owners_);
3343    }
3344    _LIBCPP_INLINE_VISIBILITY
3345    bool __release_shared() _NOEXCEPT {
3346      if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
3347        __on_zero_shared();
3348        return true;
3349      }
3350      return false;
3351    }
3352#endif
3353    _LIBCPP_INLINE_VISIBILITY
3354    long use_count() const _NOEXCEPT {
3355        return __libcpp_relaxed_load(&__shared_owners_) + 1;
3356    }
3357};
3358
3359class _LIBCPP_TYPE_VIS __shared_weak_count
3360    : private __shared_count
3361{
3362    long __shared_weak_owners_;
3363
3364public:
3365    _LIBCPP_INLINE_VISIBILITY
3366    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
3367        : __shared_count(__refs),
3368          __shared_weak_owners_(__refs) {}
3369protected:
3370    virtual ~__shared_weak_count();
3371
3372public:
3373#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3374    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3375    void __add_shared() _NOEXCEPT;
3376    void __add_weak() _NOEXCEPT;
3377    void __release_shared() _NOEXCEPT;
3378#else
3379    _LIBCPP_INLINE_VISIBILITY
3380    void __add_shared() _NOEXCEPT {
3381      __shared_count::__add_shared();
3382    }
3383    _LIBCPP_INLINE_VISIBILITY
3384    void __add_weak() _NOEXCEPT {
3385      __libcpp_atomic_refcount_increment(__shared_weak_owners_);
3386    }
3387    _LIBCPP_INLINE_VISIBILITY
3388    void __release_shared() _NOEXCEPT {
3389      if (__shared_count::__release_shared())
3390        __release_weak();
3391    }
3392#endif
3393    void __release_weak() _NOEXCEPT;
3394    _LIBCPP_INLINE_VISIBILITY
3395    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
3396    __shared_weak_count* lock() _NOEXCEPT;
3397
3398    // Define the function out only if we build static libc++ without RTTI.
3399    // Otherwise we may break clients who need to compile their projects with
3400    // -fno-rtti and yet link against a libc++.dylib compiled
3401    // without -fno-rtti.
3402#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
3403    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3404#endif
3405private:
3406    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
3407};
3408
3409template <class _Tp, class _Dp, class _Alloc>
3410class __shared_ptr_pointer
3411    : public __shared_weak_count
3412{
3413    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
3414public:
3415    _LIBCPP_INLINE_VISIBILITY
3416    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
3417        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
3418
3419#ifndef _LIBCPP_NO_RTTI
3420    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3421#endif
3422
3423private:
3424    virtual void __on_zero_shared() _NOEXCEPT;
3425    virtual void __on_zero_shared_weak() _NOEXCEPT;
3426};
3427
3428#ifndef _LIBCPP_NO_RTTI
3429
3430template <class _Tp, class _Dp, class _Alloc>
3431const void*
3432__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
3433{
3434    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr;
3435}
3436
3437#endif  // _LIBCPP_NO_RTTI
3438
3439template <class _Tp, class _Dp, class _Alloc>
3440void
3441__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
3442{
3443    __data_.first().second()(__data_.first().first());
3444    __data_.first().second().~_Dp();
3445}
3446
3447template <class _Tp, class _Dp, class _Alloc>
3448void
3449__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3450{
3451    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
3452    typedef allocator_traits<_Al> _ATraits;
3453    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3454
3455    _Al __a(__data_.second());
3456    __data_.second().~_Alloc();
3457    __a.deallocate(_PTraits::pointer_to(*this), 1);
3458}
3459
3460template <class _Tp, class _Alloc>
3461class __shared_ptr_emplace
3462    : public __shared_weak_count
3463{
3464    __compressed_pair<_Alloc, _Tp> __data_;
3465public:
3466
3467    _LIBCPP_INLINE_VISIBILITY
3468    __shared_ptr_emplace(_Alloc __a)
3469        :  __data_(_VSTD::move(__a), __value_init_tag()) {}
3470
3471
3472#ifndef _LIBCPP_HAS_NO_VARIADICS
3473    template <class ..._Args>
3474        _LIBCPP_INLINE_VISIBILITY
3475        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
3476            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
3477                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
3478#else  // _LIBCPP_HAS_NO_VARIADICS
3479
3480    template <class _A0>
3481        _LIBCPP_INLINE_VISIBILITY
3482        __shared_ptr_emplace(_Alloc __a, _A0& __a0)
3483            :  __data_(__a, _Tp(__a0)) {}
3484
3485    template <class _A0, class _A1>
3486        _LIBCPP_INLINE_VISIBILITY
3487        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
3488            :  __data_(__a, _Tp(__a0, __a1)) {}
3489
3490    template <class _A0, class _A1, class _A2>
3491        _LIBCPP_INLINE_VISIBILITY
3492        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
3493            :  __data_(__a, _Tp(__a0, __a1, __a2)) {}
3494
3495#endif  // _LIBCPP_HAS_NO_VARIADICS
3496
3497private:
3498    virtual void __on_zero_shared() _NOEXCEPT;
3499    virtual void __on_zero_shared_weak() _NOEXCEPT;
3500public:
3501    _LIBCPP_INLINE_VISIBILITY
3502    _Tp* get() _NOEXCEPT {return _VSTD::addressof(__data_.second());}
3503};
3504
3505template <class _Tp, class _Alloc>
3506void
3507__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
3508{
3509    __data_.second().~_Tp();
3510}
3511
3512template <class _Tp, class _Alloc>
3513void
3514__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3515{
3516    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
3517    typedef allocator_traits<_Al> _ATraits;
3518    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3519    _Al __a(__data_.first());
3520    __data_.first().~_Alloc();
3521    __a.deallocate(_PTraits::pointer_to(*this), 1);
3522}
3523
3524struct __shared_ptr_dummy_rebind_allocator_type;
3525template <>
3526class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type>
3527{
3528public:
3529    template <class _Other>
3530    struct rebind
3531    {
3532        typedef allocator<_Other> other;
3533    };
3534};
3535
3536template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
3537
3538template<class _Tp, class _Up>
3539struct __compatible_with
3540#if _LIBCPP_STD_VER > 14
3541    : is_convertible<remove_extent_t<_Tp>*, remove_extent_t<_Up>*> {};
3542#else
3543    : is_convertible<_Tp*, _Up*> {};
3544#endif // _LIBCPP_STD_VER > 14
3545
3546#if defined(_LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI)
3547#  define _LIBCPP_SHARED_PTR_TRIVIAL_ABI __attribute__((trivial_abi))
3548#else
3549#  define _LIBCPP_SHARED_PTR_TRIVIAL_ABI
3550#endif
3551
3552template<class _Tp>
3553class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS shared_ptr
3554{
3555public:
3556#if _LIBCPP_STD_VER > 14
3557    typedef weak_ptr<_Tp> weak_type;
3558    typedef remove_extent_t<_Tp> element_type;
3559#else
3560    typedef _Tp element_type;
3561#endif
3562
3563private:
3564    element_type*      __ptr_;
3565    __shared_weak_count* __cntrl_;
3566
3567    struct __nat {int __for_bool_;};
3568public:
3569    _LIBCPP_INLINE_VISIBILITY
3570    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
3571    _LIBCPP_INLINE_VISIBILITY
3572    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
3573    template<class _Yp>
3574        explicit shared_ptr(_Yp* __p,
3575                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat());
3576    template<class _Yp, class _Dp>
3577        shared_ptr(_Yp* __p, _Dp __d,
3578                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat());
3579    template<class _Yp, class _Dp, class _Alloc>
3580        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3581                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat());
3582    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
3583    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
3584    template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
3585    _LIBCPP_INLINE_VISIBILITY
3586    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
3587    template<class _Yp>
3588        _LIBCPP_INLINE_VISIBILITY
3589        shared_ptr(const shared_ptr<_Yp>& __r,
3590                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat())
3591                       _NOEXCEPT;
3592#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3593    _LIBCPP_INLINE_VISIBILITY
3594    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
3595    template<class _Yp> _LIBCPP_INLINE_VISIBILITY  shared_ptr(shared_ptr<_Yp>&& __r,
3596                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat())
3597                       _NOEXCEPT;
3598#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3599    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
3600                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type= __nat());
3601#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3602#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3603    template<class _Yp>
3604        shared_ptr(auto_ptr<_Yp>&& __r,
3605                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3606#else
3607    template<class _Yp>
3608        shared_ptr(auto_ptr<_Yp> __r,
3609                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3610#endif
3611#endif
3612    template <class _Yp, class _Dp>
3613        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3614                   typename enable_if
3615                   <
3616                       !is_lvalue_reference<_Dp>::value &&
3617                       !is_array<_Yp>::value &&
3618                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3619                       __nat
3620                   >::type = __nat());
3621    template <class _Yp, class _Dp>
3622        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3623                   typename enable_if
3624                   <
3625                       is_lvalue_reference<_Dp>::value &&
3626                       !is_array<_Yp>::value &&
3627                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3628                       __nat
3629                   >::type = __nat());
3630
3631    ~shared_ptr();
3632
3633    _LIBCPP_INLINE_VISIBILITY
3634    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
3635    template<class _Yp>
3636        typename enable_if
3637        <
3638            __compatible_with<_Yp, element_type>::value,
3639            shared_ptr&
3640        >::type
3641        _LIBCPP_INLINE_VISIBILITY
3642        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
3643#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3644    _LIBCPP_INLINE_VISIBILITY
3645    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
3646    template<class _Yp>
3647        typename enable_if
3648        <
3649            __compatible_with<_Yp, element_type>::value,
3650            shared_ptr&
3651        >::type
3652        _LIBCPP_INLINE_VISIBILITY
3653        operator=(shared_ptr<_Yp>&& __r);
3654#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3655    template<class _Yp>
3656        _LIBCPP_INLINE_VISIBILITY
3657        typename enable_if
3658        <
3659            !is_array<_Yp>::value &&
3660            is_convertible<_Yp*, element_type*>::value,
3661            shared_ptr
3662        >::type&
3663        operator=(auto_ptr<_Yp>&& __r);
3664#endif
3665#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3666#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3667    template<class _Yp>
3668        _LIBCPP_INLINE_VISIBILITY
3669        typename enable_if
3670        <
3671            !is_array<_Yp>::value &&
3672            is_convertible<_Yp*, element_type*>::value,
3673            shared_ptr&
3674        >::type
3675        operator=(auto_ptr<_Yp> __r);
3676#endif
3677#endif
3678    template <class _Yp, class _Dp>
3679        typename enable_if
3680        <
3681            !is_array<_Yp>::value &&
3682            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3683            shared_ptr&
3684        >::type
3685#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3686        _LIBCPP_INLINE_VISIBILITY
3687        operator=(unique_ptr<_Yp, _Dp>&& __r);
3688#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3689        _LIBCPP_INLINE_VISIBILITY
3690        operator=(unique_ptr<_Yp, _Dp> __r);
3691#endif
3692
3693    _LIBCPP_INLINE_VISIBILITY
3694    void swap(shared_ptr& __r) _NOEXCEPT;
3695    _LIBCPP_INLINE_VISIBILITY
3696    void reset() _NOEXCEPT;
3697    template<class _Yp>
3698        typename enable_if
3699        <
3700            __compatible_with<_Yp, element_type>::value,
3701            void
3702        >::type
3703        _LIBCPP_INLINE_VISIBILITY
3704        reset(_Yp* __p);
3705    template<class _Yp, class _Dp>
3706        typename enable_if
3707        <
3708            __compatible_with<_Yp, element_type>::value,
3709            void
3710        >::type
3711        _LIBCPP_INLINE_VISIBILITY
3712        reset(_Yp* __p, _Dp __d);
3713    template<class _Yp, class _Dp, class _Alloc>
3714        typename enable_if
3715        <
3716            __compatible_with<_Yp, element_type>::value,
3717            void
3718        >::type
3719        _LIBCPP_INLINE_VISIBILITY
3720        reset(_Yp* __p, _Dp __d, _Alloc __a);
3721
3722    _LIBCPP_INLINE_VISIBILITY
3723    element_type* get() const _NOEXCEPT {return __ptr_;}
3724    _LIBCPP_INLINE_VISIBILITY
3725    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
3726        {return *__ptr_;}
3727    _LIBCPP_INLINE_VISIBILITY
3728    element_type* operator->() const _NOEXCEPT
3729    {
3730        static_assert(!_VSTD::is_array<_Tp>::value,
3731                      "std::shared_ptr<T>::operator-> is only valid when T is not an array type.");
3732        return __ptr_;
3733    }
3734    _LIBCPP_INLINE_VISIBILITY
3735    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
3736    _LIBCPP_INLINE_VISIBILITY
3737    bool unique() const _NOEXCEPT {return use_count() == 1;}
3738    _LIBCPP_INLINE_VISIBILITY
3739    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
3740    template <class _Up>
3741        _LIBCPP_INLINE_VISIBILITY
3742        bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT
3743        {return __cntrl_ < __p.__cntrl_;}
3744    template <class _Up>
3745        _LIBCPP_INLINE_VISIBILITY
3746        bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT
3747        {return __cntrl_ < __p.__cntrl_;}
3748    _LIBCPP_INLINE_VISIBILITY
3749    bool
3750    __owner_equivalent(const shared_ptr& __p) const
3751        {return __cntrl_ == __p.__cntrl_;}
3752
3753#if _LIBCPP_STD_VER > 14
3754    typename add_lvalue_reference<element_type>::type
3755    _LIBCPP_INLINE_VISIBILITY
3756    operator[](ptrdiff_t __i) const
3757    {
3758            static_assert(_VSTD::is_array<_Tp>::value,
3759                          "std::shared_ptr<T>::operator[] is only valid when T is an array type.");
3760            return __ptr_[__i];
3761    }
3762#endif
3763
3764#ifndef _LIBCPP_NO_RTTI
3765    template <class _Dp>
3766        _LIBCPP_INLINE_VISIBILITY
3767        _Dp* __get_deleter() const _NOEXCEPT
3768            {return static_cast<_Dp*>(__cntrl_
3769                    ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp)))
3770                      : nullptr);}
3771#endif  // _LIBCPP_NO_RTTI
3772
3773    template<class _Yp, class _CntrlBlk>
3774    static shared_ptr<_Tp>
3775    __create_with_control_block(_Yp* __p, _CntrlBlk* __cntrl) _NOEXCEPT
3776    {
3777        shared_ptr<_Tp> __r;
3778        __r.__ptr_ = __p;
3779        __r.__cntrl_ = __cntrl;
3780        __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
3781        return __r;
3782    }
3783
3784private:
3785    template <class _Yp, bool = is_function<_Yp>::value>
3786        struct __shared_ptr_default_allocator
3787        {
3788            typedef allocator<_Yp> type;
3789        };
3790
3791    template <class _Yp>
3792        struct __shared_ptr_default_allocator<_Yp, true>
3793        {
3794            typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
3795        };
3796
3797    template <class _Yp, class _OrigPtr>
3798        _LIBCPP_INLINE_VISIBILITY
3799        typename enable_if<is_convertible<_OrigPtr*,
3800                                          const enable_shared_from_this<_Yp>*
3801        >::value,
3802            void>::type
3803        __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
3804                           _OrigPtr* __ptr) _NOEXCEPT
3805        {
3806            typedef typename remove_cv<_Yp>::type _RawYp;
3807            if (__e && __e->__weak_this_.expired())
3808            {
3809                __e->__weak_this_ = shared_ptr<_RawYp>(*this,
3810                    const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
3811            }
3812        }
3813
3814    _LIBCPP_INLINE_VISIBILITY void __enable_weak_this(...) _NOEXCEPT {}
3815
3816    template <class, class _Yp>
3817        struct __shared_ptr_default_delete
3818            : default_delete<_Yp> {};
3819
3820    template <class _Yp, class _Un, size_t _Sz>
3821        struct __shared_ptr_default_delete<_Yp[_Sz], _Un>
3822            : default_delete<_Yp[]> {};
3823
3824    template <class _Yp, class _Un>
3825        struct __shared_ptr_default_delete<_Yp[], _Un>
3826            : default_delete<_Yp[]> {};
3827
3828    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
3829    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
3830};
3831
3832#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
3833template<class _Tp>
3834shared_ptr(weak_ptr<_Tp>) -> shared_ptr<_Tp>;
3835template<class _Tp, class _Dp>
3836shared_ptr(unique_ptr<_Tp, _Dp>) -> shared_ptr<_Tp>;
3837#endif
3838
3839template<class _Tp>
3840inline
3841_LIBCPP_CONSTEXPR
3842shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
3843    : __ptr_(0),
3844      __cntrl_(0)
3845{
3846}
3847
3848template<class _Tp>
3849inline
3850_LIBCPP_CONSTEXPR
3851shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
3852    : __ptr_(0),
3853      __cntrl_(0)
3854{
3855}
3856
3857template<class _Tp>
3858template<class _Yp>
3859shared_ptr<_Tp>::shared_ptr(_Yp* __p,
3860                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3861    : __ptr_(__p)
3862{
3863    unique_ptr<_Yp> __hold(__p);
3864    typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3865    typedef __shared_ptr_pointer<_Yp*, __shared_ptr_default_delete<_Tp, _Yp>, _AllocT > _CntrlBlk;
3866    __cntrl_ = new _CntrlBlk(__p, __shared_ptr_default_delete<_Tp, _Yp>(), _AllocT());
3867    __hold.release();
3868    __enable_weak_this(__p, __p);
3869}
3870
3871template<class _Tp>
3872template<class _Yp, class _Dp>
3873shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
3874                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3875    : __ptr_(__p)
3876{
3877#ifndef _LIBCPP_NO_EXCEPTIONS
3878    try
3879    {
3880#endif  // _LIBCPP_NO_EXCEPTIONS
3881        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3882        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
3883        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
3884        __enable_weak_this(__p, __p);
3885#ifndef _LIBCPP_NO_EXCEPTIONS
3886    }
3887    catch (...)
3888    {
3889        __d(__p);
3890        throw;
3891    }
3892#endif  // _LIBCPP_NO_EXCEPTIONS
3893}
3894
3895template<class _Tp>
3896template<class _Dp>
3897shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
3898    : __ptr_(0)
3899{
3900#ifndef _LIBCPP_NO_EXCEPTIONS
3901    try
3902    {
3903#endif  // _LIBCPP_NO_EXCEPTIONS
3904        typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
3905        typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
3906        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
3907#ifndef _LIBCPP_NO_EXCEPTIONS
3908    }
3909    catch (...)
3910    {
3911        __d(__p);
3912        throw;
3913    }
3914#endif  // _LIBCPP_NO_EXCEPTIONS
3915}
3916
3917template<class _Tp>
3918template<class _Yp, class _Dp, class _Alloc>
3919shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3920                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3921    : __ptr_(__p)
3922{
3923#ifndef _LIBCPP_NO_EXCEPTIONS
3924    try
3925    {
3926#endif  // _LIBCPP_NO_EXCEPTIONS
3927        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
3928        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
3929        typedef __allocator_destructor<_A2> _D2;
3930        _A2 __a2(__a);
3931        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
3932        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
3933            _CntrlBlk(__p, __d, __a);
3934        __cntrl_ = _VSTD::addressof(*__hold2.release());
3935        __enable_weak_this(__p, __p);
3936#ifndef _LIBCPP_NO_EXCEPTIONS
3937    }
3938    catch (...)
3939    {
3940        __d(__p);
3941        throw;
3942    }
3943#endif  // _LIBCPP_NO_EXCEPTIONS
3944}
3945
3946template<class _Tp>
3947template<class _Dp, class _Alloc>
3948shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
3949    : __ptr_(0)
3950{
3951#ifndef _LIBCPP_NO_EXCEPTIONS
3952    try
3953    {
3954#endif  // _LIBCPP_NO_EXCEPTIONS
3955        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
3956        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
3957        typedef __allocator_destructor<_A2> _D2;
3958        _A2 __a2(__a);
3959        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
3960        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
3961            _CntrlBlk(__p, __d, __a);
3962        __cntrl_ = _VSTD::addressof(*__hold2.release());
3963#ifndef _LIBCPP_NO_EXCEPTIONS
3964    }
3965    catch (...)
3966    {
3967        __d(__p);
3968        throw;
3969    }
3970#endif  // _LIBCPP_NO_EXCEPTIONS
3971}
3972
3973template<class _Tp>
3974template<class _Yp>
3975inline
3976shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
3977    : __ptr_(__p),
3978      __cntrl_(__r.__cntrl_)
3979{
3980    if (__cntrl_)
3981        __cntrl_->__add_shared();
3982}
3983
3984template<class _Tp>
3985inline
3986shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
3987    : __ptr_(__r.__ptr_),
3988      __cntrl_(__r.__cntrl_)
3989{
3990    if (__cntrl_)
3991        __cntrl_->__add_shared();
3992}
3993
3994template<class _Tp>
3995template<class _Yp>
3996inline
3997shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
3998                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3999         _NOEXCEPT
4000    : __ptr_(__r.__ptr_),
4001      __cntrl_(__r.__cntrl_)
4002{
4003    if (__cntrl_)
4004        __cntrl_->__add_shared();
4005}
4006
4007#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4008
4009template<class _Tp>
4010inline
4011shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
4012    : __ptr_(__r.__ptr_),
4013      __cntrl_(__r.__cntrl_)
4014{
4015    __r.__ptr_ = 0;
4016    __r.__cntrl_ = 0;
4017}
4018
4019template<class _Tp>
4020template<class _Yp>
4021inline
4022shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
4023                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
4024         _NOEXCEPT
4025    : __ptr_(__r.__ptr_),
4026      __cntrl_(__r.__cntrl_)
4027{
4028    __r.__ptr_ = 0;
4029    __r.__cntrl_ = 0;
4030}
4031
4032#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4033
4034#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4035template<class _Tp>
4036template<class _Yp>
4037#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4038shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
4039#else
4040shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp> __r,
4041#endif
4042                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4043    : __ptr_(__r.get())
4044{
4045    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
4046    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
4047    __enable_weak_this(__r.get(), __r.get());
4048    __r.release();
4049}
4050#endif
4051
4052template<class _Tp>
4053template <class _Yp, class _Dp>
4054shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4055                            typename enable_if
4056                            <
4057                                !is_lvalue_reference<_Dp>::value &&
4058                                !is_array<_Yp>::value &&
4059                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4060                                __nat
4061                            >::type)
4062    : __ptr_(__r.get())
4063{
4064#if _LIBCPP_STD_VER > 11
4065    if (__ptr_ == nullptr)
4066        __cntrl_ = nullptr;
4067    else
4068#endif
4069    {
4070        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4071        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
4072        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), _AllocT());
4073        __enable_weak_this(__r.get(), __r.get());
4074    }
4075    __r.release();
4076}
4077
4078template<class _Tp>
4079template <class _Yp, class _Dp>
4080shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4081                            typename enable_if
4082                            <
4083                                is_lvalue_reference<_Dp>::value &&
4084                                !is_array<_Yp>::value &&
4085                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4086                                __nat
4087                            >::type)
4088    : __ptr_(__r.get())
4089{
4090#if _LIBCPP_STD_VER > 11
4091    if (__ptr_ == nullptr)
4092        __cntrl_ = nullptr;
4093    else
4094#endif
4095    {
4096        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4097        typedef __shared_ptr_pointer<_Yp*,
4098                                     reference_wrapper<typename remove_reference<_Dp>::type>,
4099                                     _AllocT > _CntrlBlk;
4100        __cntrl_ = new _CntrlBlk(__r.get(), _VSTD::ref(__r.get_deleter()), _AllocT());
4101        __enable_weak_this(__r.get(), __r.get());
4102    }
4103    __r.release();
4104}
4105
4106template<class _Tp>
4107shared_ptr<_Tp>::~shared_ptr()
4108{
4109    if (__cntrl_)
4110        __cntrl_->__release_shared();
4111}
4112
4113template<class _Tp>
4114inline
4115shared_ptr<_Tp>&
4116shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
4117{
4118    shared_ptr(__r).swap(*this);
4119    return *this;
4120}
4121
4122template<class _Tp>
4123template<class _Yp>
4124inline
4125typename enable_if
4126<
4127    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4128    shared_ptr<_Tp>&
4129>::type
4130shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
4131{
4132    shared_ptr(__r).swap(*this);
4133    return *this;
4134}
4135
4136#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4137
4138template<class _Tp>
4139inline
4140shared_ptr<_Tp>&
4141shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
4142{
4143    shared_ptr(_VSTD::move(__r)).swap(*this);
4144    return *this;
4145}
4146
4147template<class _Tp>
4148template<class _Yp>
4149inline
4150typename enable_if
4151<
4152    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4153    shared_ptr<_Tp>&
4154>::type
4155shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
4156{
4157    shared_ptr(_VSTD::move(__r)).swap(*this);
4158    return *this;
4159}
4160
4161#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4162template<class _Tp>
4163template<class _Yp>
4164inline
4165typename enable_if
4166<
4167    !is_array<_Yp>::value &&
4168    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4169    shared_ptr<_Tp>
4170>::type&
4171shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
4172{
4173    shared_ptr(_VSTD::move(__r)).swap(*this);
4174    return *this;
4175}
4176#endif
4177
4178template<class _Tp>
4179template <class _Yp, class _Dp>
4180inline
4181typename enable_if
4182<
4183    !is_array<_Yp>::value &&
4184    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4185                   typename shared_ptr<_Tp>::element_type*>::value,
4186    shared_ptr<_Tp>&
4187>::type
4188shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
4189{
4190    shared_ptr(_VSTD::move(__r)).swap(*this);
4191    return *this;
4192}
4193
4194#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4195
4196#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4197template<class _Tp>
4198template<class _Yp>
4199inline _LIBCPP_INLINE_VISIBILITY
4200typename enable_if
4201<
4202    !is_array<_Yp>::value &&
4203    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4204    shared_ptr<_Tp>&
4205>::type
4206shared_ptr<_Tp>::operator=(auto_ptr<_Yp> __r)
4207{
4208    shared_ptr(__r).swap(*this);
4209    return *this;
4210}
4211#endif
4212
4213template<class _Tp>
4214template <class _Yp, class _Dp>
4215inline _LIBCPP_INLINE_VISIBILITY
4216typename enable_if
4217<
4218    !is_array<_Yp>::value &&
4219    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4220                   typename shared_ptr<_Tp>::element_type*>::value,
4221    shared_ptr<_Tp>&
4222>::type
4223shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp> __r)
4224{
4225    shared_ptr(_VSTD::move(__r)).swap(*this);
4226    return *this;
4227}
4228
4229#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4230
4231template<class _Tp>
4232inline
4233void
4234shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
4235{
4236    _VSTD::swap(__ptr_, __r.__ptr_);
4237    _VSTD::swap(__cntrl_, __r.__cntrl_);
4238}
4239
4240template<class _Tp>
4241inline
4242void
4243shared_ptr<_Tp>::reset() _NOEXCEPT
4244{
4245    shared_ptr().swap(*this);
4246}
4247
4248template<class _Tp>
4249template<class _Yp>
4250inline
4251typename enable_if
4252<
4253    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4254    void
4255>::type
4256shared_ptr<_Tp>::reset(_Yp* __p)
4257{
4258    shared_ptr(__p).swap(*this);
4259}
4260
4261template<class _Tp>
4262template<class _Yp, class _Dp>
4263inline
4264typename enable_if
4265<
4266    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4267    void
4268>::type
4269shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
4270{
4271    shared_ptr(__p, __d).swap(*this);
4272}
4273
4274template<class _Tp>
4275template<class _Yp, class _Dp, class _Alloc>
4276inline
4277typename enable_if
4278<
4279    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4280    void
4281>::type
4282shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
4283{
4284    shared_ptr(__p, __d, __a).swap(*this);
4285}
4286
4287template<class _Tp, class ..._Args>
4288inline _LIBCPP_INLINE_VISIBILITY
4289typename enable_if
4290<
4291    !is_array<_Tp>::value,
4292    shared_ptr<_Tp>
4293>::type
4294make_shared(_Args&& ...__args)
4295{
4296    static_assert(is_constructible<_Tp, _Args...>::value, "Can't construct object in make_shared");
4297    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4298    typedef allocator<_CntrlBlk> _A2;
4299    typedef __allocator_destructor<_A2> _D2;
4300
4301    _A2 __a2;
4302    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4303    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
4304
4305    _Tp *__ptr = __hold2.get()->get();
4306    return shared_ptr<_Tp>::__create_with_control_block(__ptr, __hold2.release());
4307}
4308
4309template<class _Tp, class _Alloc, class ..._Args>
4310inline _LIBCPP_INLINE_VISIBILITY
4311typename enable_if
4312<
4313    !is_array<_Tp>::value,
4314    shared_ptr<_Tp>
4315>::type
4316allocate_shared(const _Alloc& __a, _Args&& ...__args)
4317{
4318    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in allocate_shared");
4319
4320    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4321    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4322    typedef __allocator_destructor<_A2> _D2;
4323
4324    _A2 __a2(__a);
4325    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4326    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4327        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
4328
4329    typename shared_ptr<_Tp>::element_type *__p = __hold2.get()->get();
4330    return shared_ptr<_Tp>::__create_with_control_block(__p, _VSTD::addressof(*__hold2.release()));
4331}
4332
4333template<class _Tp, class _Up>
4334inline _LIBCPP_INLINE_VISIBILITY
4335bool
4336operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4337{
4338    return __x.get() == __y.get();
4339}
4340
4341template<class _Tp, class _Up>
4342inline _LIBCPP_INLINE_VISIBILITY
4343bool
4344operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4345{
4346    return !(__x == __y);
4347}
4348
4349template<class _Tp, class _Up>
4350inline _LIBCPP_INLINE_VISIBILITY
4351bool
4352operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4353{
4354#if _LIBCPP_STD_VER <= 11
4355    typedef typename common_type<_Tp*, _Up*>::type _Vp;
4356    return less<_Vp>()(__x.get(), __y.get());
4357#else
4358    return less<>()(__x.get(), __y.get());
4359#endif
4360
4361}
4362
4363template<class _Tp, class _Up>
4364inline _LIBCPP_INLINE_VISIBILITY
4365bool
4366operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4367{
4368    return __y < __x;
4369}
4370
4371template<class _Tp, class _Up>
4372inline _LIBCPP_INLINE_VISIBILITY
4373bool
4374operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4375{
4376    return !(__y < __x);
4377}
4378
4379template<class _Tp, class _Up>
4380inline _LIBCPP_INLINE_VISIBILITY
4381bool
4382operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4383{
4384    return !(__x < __y);
4385}
4386
4387template<class _Tp>
4388inline _LIBCPP_INLINE_VISIBILITY
4389bool
4390operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4391{
4392    return !__x;
4393}
4394
4395template<class _Tp>
4396inline _LIBCPP_INLINE_VISIBILITY
4397bool
4398operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4399{
4400    return !__x;
4401}
4402
4403template<class _Tp>
4404inline _LIBCPP_INLINE_VISIBILITY
4405bool
4406operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4407{
4408    return static_cast<bool>(__x);
4409}
4410
4411template<class _Tp>
4412inline _LIBCPP_INLINE_VISIBILITY
4413bool
4414operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4415{
4416    return static_cast<bool>(__x);
4417}
4418
4419template<class _Tp>
4420inline _LIBCPP_INLINE_VISIBILITY
4421bool
4422operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4423{
4424    return less<_Tp*>()(__x.get(), nullptr);
4425}
4426
4427template<class _Tp>
4428inline _LIBCPP_INLINE_VISIBILITY
4429bool
4430operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4431{
4432    return less<_Tp*>()(nullptr, __x.get());
4433}
4434
4435template<class _Tp>
4436inline _LIBCPP_INLINE_VISIBILITY
4437bool
4438operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4439{
4440    return nullptr < __x;
4441}
4442
4443template<class _Tp>
4444inline _LIBCPP_INLINE_VISIBILITY
4445bool
4446operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4447{
4448    return __x < nullptr;
4449}
4450
4451template<class _Tp>
4452inline _LIBCPP_INLINE_VISIBILITY
4453bool
4454operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4455{
4456    return !(nullptr < __x);
4457}
4458
4459template<class _Tp>
4460inline _LIBCPP_INLINE_VISIBILITY
4461bool
4462operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4463{
4464    return !(__x < nullptr);
4465}
4466
4467template<class _Tp>
4468inline _LIBCPP_INLINE_VISIBILITY
4469bool
4470operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4471{
4472    return !(__x < nullptr);
4473}
4474
4475template<class _Tp>
4476inline _LIBCPP_INLINE_VISIBILITY
4477bool
4478operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4479{
4480    return !(nullptr < __x);
4481}
4482
4483template<class _Tp>
4484inline _LIBCPP_INLINE_VISIBILITY
4485void
4486swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
4487{
4488    __x.swap(__y);
4489}
4490
4491template<class _Tp, class _Up>
4492inline _LIBCPP_INLINE_VISIBILITY
4493shared_ptr<_Tp>
4494static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4495{
4496    return shared_ptr<_Tp>(__r,
4497                           static_cast<
4498                               typename shared_ptr<_Tp>::element_type*>(__r.get()));
4499}
4500
4501template<class _Tp, class _Up>
4502inline _LIBCPP_INLINE_VISIBILITY
4503shared_ptr<_Tp>
4504dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4505{
4506    typedef typename shared_ptr<_Tp>::element_type _ET;
4507    _ET* __p = dynamic_cast<_ET*>(__r.get());
4508    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
4509}
4510
4511template<class _Tp, class _Up>
4512shared_ptr<_Tp>
4513const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4514{
4515    typedef typename shared_ptr<_Tp>::element_type _RTp;
4516    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
4517}
4518
4519template<class _Tp, class _Up>
4520shared_ptr<_Tp>
4521reinterpret_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4522{
4523    return shared_ptr<_Tp>(__r,
4524                           reinterpret_cast<
4525                               typename shared_ptr<_Tp>::element_type*>(__r.get()));
4526}
4527
4528#ifndef _LIBCPP_NO_RTTI
4529
4530template<class _Dp, class _Tp>
4531inline _LIBCPP_INLINE_VISIBILITY
4532_Dp*
4533get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
4534{
4535    return __p.template __get_deleter<_Dp>();
4536}
4537
4538#endif  // _LIBCPP_NO_RTTI
4539
4540template<class _Tp>
4541class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS weak_ptr
4542{
4543public:
4544    typedef _Tp element_type;
4545private:
4546    element_type*        __ptr_;
4547    __shared_weak_count* __cntrl_;
4548
4549public:
4550    _LIBCPP_INLINE_VISIBILITY
4551    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
4552    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r,
4553                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4554                        _NOEXCEPT;
4555    _LIBCPP_INLINE_VISIBILITY
4556    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
4557    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r,
4558                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4559                         _NOEXCEPT;
4560
4561#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4562    _LIBCPP_INLINE_VISIBILITY
4563    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
4564    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r,
4565                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4566                         _NOEXCEPT;
4567#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4568    ~weak_ptr();
4569
4570    _LIBCPP_INLINE_VISIBILITY
4571    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
4572    template<class _Yp>
4573        typename enable_if
4574        <
4575            is_convertible<_Yp*, element_type*>::value,
4576            weak_ptr&
4577        >::type
4578        _LIBCPP_INLINE_VISIBILITY
4579        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
4580
4581#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4582
4583    _LIBCPP_INLINE_VISIBILITY
4584    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
4585    template<class _Yp>
4586        typename enable_if
4587        <
4588            is_convertible<_Yp*, element_type*>::value,
4589            weak_ptr&
4590        >::type
4591        _LIBCPP_INLINE_VISIBILITY
4592        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
4593
4594#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4595
4596    template<class _Yp>
4597        typename enable_if
4598        <
4599            is_convertible<_Yp*, element_type*>::value,
4600            weak_ptr&
4601        >::type
4602        _LIBCPP_INLINE_VISIBILITY
4603        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
4604
4605    _LIBCPP_INLINE_VISIBILITY
4606    void swap(weak_ptr& __r) _NOEXCEPT;
4607    _LIBCPP_INLINE_VISIBILITY
4608    void reset() _NOEXCEPT;
4609
4610    _LIBCPP_INLINE_VISIBILITY
4611    long use_count() const _NOEXCEPT
4612        {return __cntrl_ ? __cntrl_->use_count() : 0;}
4613    _LIBCPP_INLINE_VISIBILITY
4614    bool expired() const _NOEXCEPT
4615        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
4616    shared_ptr<_Tp> lock() const _NOEXCEPT;
4617    template<class _Up>
4618        _LIBCPP_INLINE_VISIBILITY
4619        bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT
4620        {return __cntrl_ < __r.__cntrl_;}
4621    template<class _Up>
4622        _LIBCPP_INLINE_VISIBILITY
4623        bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT
4624        {return __cntrl_ < __r.__cntrl_;}
4625
4626    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
4627    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
4628};
4629
4630#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
4631template<class _Tp>
4632weak_ptr(shared_ptr<_Tp>) -> weak_ptr<_Tp>;
4633#endif
4634
4635template<class _Tp>
4636inline
4637_LIBCPP_CONSTEXPR
4638weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
4639    : __ptr_(0),
4640      __cntrl_(0)
4641{
4642}
4643
4644template<class _Tp>
4645inline
4646weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
4647    : __ptr_(__r.__ptr_),
4648      __cntrl_(__r.__cntrl_)
4649{
4650    if (__cntrl_)
4651        __cntrl_->__add_weak();
4652}
4653
4654template<class _Tp>
4655template<class _Yp>
4656inline
4657weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
4658                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4659                         _NOEXCEPT
4660    : __ptr_(__r.__ptr_),
4661      __cntrl_(__r.__cntrl_)
4662{
4663    if (__cntrl_)
4664        __cntrl_->__add_weak();
4665}
4666
4667template<class _Tp>
4668template<class _Yp>
4669inline
4670weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
4671                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4672         _NOEXCEPT
4673    : __ptr_(__r.__ptr_),
4674      __cntrl_(__r.__cntrl_)
4675{
4676    if (__cntrl_)
4677        __cntrl_->__add_weak();
4678}
4679
4680#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4681
4682template<class _Tp>
4683inline
4684weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
4685    : __ptr_(__r.__ptr_),
4686      __cntrl_(__r.__cntrl_)
4687{
4688    __r.__ptr_ = 0;
4689    __r.__cntrl_ = 0;
4690}
4691
4692template<class _Tp>
4693template<class _Yp>
4694inline
4695weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
4696                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4697         _NOEXCEPT
4698    : __ptr_(__r.__ptr_),
4699      __cntrl_(__r.__cntrl_)
4700{
4701    __r.__ptr_ = 0;
4702    __r.__cntrl_ = 0;
4703}
4704
4705#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4706
4707template<class _Tp>
4708weak_ptr<_Tp>::~weak_ptr()
4709{
4710    if (__cntrl_)
4711        __cntrl_->__release_weak();
4712}
4713
4714template<class _Tp>
4715inline
4716weak_ptr<_Tp>&
4717weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
4718{
4719    weak_ptr(__r).swap(*this);
4720    return *this;
4721}
4722
4723template<class _Tp>
4724template<class _Yp>
4725inline
4726typename enable_if
4727<
4728    is_convertible<_Yp*, _Tp*>::value,
4729    weak_ptr<_Tp>&
4730>::type
4731weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
4732{
4733    weak_ptr(__r).swap(*this);
4734    return *this;
4735}
4736
4737#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4738
4739template<class _Tp>
4740inline
4741weak_ptr<_Tp>&
4742weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
4743{
4744    weak_ptr(_VSTD::move(__r)).swap(*this);
4745    return *this;
4746}
4747
4748template<class _Tp>
4749template<class _Yp>
4750inline
4751typename enable_if
4752<
4753    is_convertible<_Yp*, _Tp*>::value,
4754    weak_ptr<_Tp>&
4755>::type
4756weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
4757{
4758    weak_ptr(_VSTD::move(__r)).swap(*this);
4759    return *this;
4760}
4761
4762#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4763
4764template<class _Tp>
4765template<class _Yp>
4766inline
4767typename enable_if
4768<
4769    is_convertible<_Yp*, _Tp*>::value,
4770    weak_ptr<_Tp>&
4771>::type
4772weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
4773{
4774    weak_ptr(__r).swap(*this);
4775    return *this;
4776}
4777
4778template<class _Tp>
4779inline
4780void
4781weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
4782{
4783    _VSTD::swap(__ptr_, __r.__ptr_);
4784    _VSTD::swap(__cntrl_, __r.__cntrl_);
4785}
4786
4787template<class _Tp>
4788inline _LIBCPP_INLINE_VISIBILITY
4789void
4790swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
4791{
4792    __x.swap(__y);
4793}
4794
4795template<class _Tp>
4796inline
4797void
4798weak_ptr<_Tp>::reset() _NOEXCEPT
4799{
4800    weak_ptr().swap(*this);
4801}
4802
4803template<class _Tp>
4804template<class _Yp>
4805shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
4806                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4807    : __ptr_(__r.__ptr_),
4808      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
4809{
4810    if (__cntrl_ == 0)
4811        __throw_bad_weak_ptr();
4812}
4813
4814template<class _Tp>
4815shared_ptr<_Tp>
4816weak_ptr<_Tp>::lock() const _NOEXCEPT
4817{
4818    shared_ptr<_Tp> __r;
4819    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
4820    if (__r.__cntrl_)
4821        __r.__ptr_ = __ptr_;
4822    return __r;
4823}
4824
4825#if _LIBCPP_STD_VER > 14
4826template <class _Tp = void> struct owner_less;
4827#else
4828template <class _Tp> struct owner_less;
4829#endif
4830
4831template <class _Tp>
4832struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> >
4833    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
4834{
4835    typedef bool result_type;
4836    _LIBCPP_INLINE_VISIBILITY
4837    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4838        {return __x.owner_before(__y);}
4839    _LIBCPP_INLINE_VISIBILITY
4840    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4841        {return __x.owner_before(__y);}
4842    _LIBCPP_INLINE_VISIBILITY
4843    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4844        {return __x.owner_before(__y);}
4845};
4846
4847template <class _Tp>
4848struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> >
4849    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
4850{
4851    typedef bool result_type;
4852    _LIBCPP_INLINE_VISIBILITY
4853    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4854        {return __x.owner_before(__y);}
4855    _LIBCPP_INLINE_VISIBILITY
4856    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4857        {return __x.owner_before(__y);}
4858    _LIBCPP_INLINE_VISIBILITY
4859    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4860        {return __x.owner_before(__y);}
4861};
4862
4863#if _LIBCPP_STD_VER > 14
4864template <>
4865struct _LIBCPP_TEMPLATE_VIS owner_less<void>
4866{
4867    template <class _Tp, class _Up>
4868    _LIBCPP_INLINE_VISIBILITY
4869    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
4870        {return __x.owner_before(__y);}
4871    template <class _Tp, class _Up>
4872    _LIBCPP_INLINE_VISIBILITY
4873    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
4874        {return __x.owner_before(__y);}
4875    template <class _Tp, class _Up>
4876    _LIBCPP_INLINE_VISIBILITY
4877    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
4878        {return __x.owner_before(__y);}
4879    template <class _Tp, class _Up>
4880    _LIBCPP_INLINE_VISIBILITY
4881    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
4882        {return __x.owner_before(__y);}
4883    typedef void is_transparent;
4884};
4885#endif
4886
4887template<class _Tp>
4888class _LIBCPP_TEMPLATE_VIS enable_shared_from_this
4889{
4890    mutable weak_ptr<_Tp> __weak_this_;
4891protected:
4892    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
4893    enable_shared_from_this() _NOEXCEPT {}
4894    _LIBCPP_INLINE_VISIBILITY
4895    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
4896    _LIBCPP_INLINE_VISIBILITY
4897    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
4898        {return *this;}
4899    _LIBCPP_INLINE_VISIBILITY
4900    ~enable_shared_from_this() {}
4901public:
4902    _LIBCPP_INLINE_VISIBILITY
4903    shared_ptr<_Tp> shared_from_this()
4904        {return shared_ptr<_Tp>(__weak_this_);}
4905    _LIBCPP_INLINE_VISIBILITY
4906    shared_ptr<_Tp const> shared_from_this() const
4907        {return shared_ptr<const _Tp>(__weak_this_);}
4908
4909#if _LIBCPP_STD_VER > 14
4910    _LIBCPP_INLINE_VISIBILITY
4911    weak_ptr<_Tp> weak_from_this() _NOEXCEPT
4912       { return __weak_this_; }
4913
4914    _LIBCPP_INLINE_VISIBILITY
4915    weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT
4916        { return __weak_this_; }
4917#endif // _LIBCPP_STD_VER > 14
4918
4919    template <class _Up> friend class shared_ptr;
4920};
4921
4922template <class _Tp>
4923struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> >
4924{
4925    typedef shared_ptr<_Tp>      argument_type;
4926    typedef size_t               result_type;
4927
4928    _LIBCPP_INLINE_VISIBILITY
4929    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
4930    {
4931        return hash<typename shared_ptr<_Tp>::element_type*>()(__ptr.get());
4932    }
4933};
4934
4935template<class _CharT, class _Traits, class _Yp>
4936inline _LIBCPP_INLINE_VISIBILITY
4937basic_ostream<_CharT, _Traits>&
4938operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
4939
4940
4941#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
4942
4943class _LIBCPP_TYPE_VIS __sp_mut
4944{
4945    void* __lx;
4946public:
4947    void lock() _NOEXCEPT;
4948    void unlock() _NOEXCEPT;
4949
4950private:
4951    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
4952    __sp_mut(const __sp_mut&);
4953    __sp_mut& operator=(const __sp_mut&);
4954
4955    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
4956};
4957
4958_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4959__sp_mut& __get_sp_mut(const void*);
4960
4961template <class _Tp>
4962inline _LIBCPP_INLINE_VISIBILITY
4963bool
4964atomic_is_lock_free(const shared_ptr<_Tp>*)
4965{
4966    return false;
4967}
4968
4969template <class _Tp>
4970_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4971shared_ptr<_Tp>
4972atomic_load(const shared_ptr<_Tp>* __p)
4973{
4974    __sp_mut& __m = __get_sp_mut(__p);
4975    __m.lock();
4976    shared_ptr<_Tp> __q = *__p;
4977    __m.unlock();
4978    return __q;
4979}
4980
4981template <class _Tp>
4982inline _LIBCPP_INLINE_VISIBILITY
4983_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4984shared_ptr<_Tp>
4985atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
4986{
4987    return atomic_load(__p);
4988}
4989
4990template <class _Tp>
4991_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4992void
4993atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
4994{
4995    __sp_mut& __m = __get_sp_mut(__p);
4996    __m.lock();
4997    __p->swap(__r);
4998    __m.unlock();
4999}
5000
5001template <class _Tp>
5002inline _LIBCPP_INLINE_VISIBILITY
5003_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5004void
5005atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5006{
5007    atomic_store(__p, __r);
5008}
5009
5010template <class _Tp>
5011_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5012shared_ptr<_Tp>
5013atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5014{
5015    __sp_mut& __m = __get_sp_mut(__p);
5016    __m.lock();
5017    __p->swap(__r);
5018    __m.unlock();
5019    return __r;
5020}
5021
5022template <class _Tp>
5023inline _LIBCPP_INLINE_VISIBILITY
5024_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5025shared_ptr<_Tp>
5026atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5027{
5028    return atomic_exchange(__p, __r);
5029}
5030
5031template <class _Tp>
5032_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5033bool
5034atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5035{
5036    shared_ptr<_Tp> __temp;
5037    __sp_mut& __m = __get_sp_mut(__p);
5038    __m.lock();
5039    if (__p->__owner_equivalent(*__v))
5040    {
5041        _VSTD::swap(__temp, *__p);
5042        *__p = __w;
5043        __m.unlock();
5044        return true;
5045    }
5046    _VSTD::swap(__temp, *__v);
5047    *__v = *__p;
5048    __m.unlock();
5049    return false;
5050}
5051
5052template <class _Tp>
5053inline _LIBCPP_INLINE_VISIBILITY
5054_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5055bool
5056atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5057{
5058    return atomic_compare_exchange_strong(__p, __v, __w);
5059}
5060
5061template <class _Tp>
5062inline _LIBCPP_INLINE_VISIBILITY
5063_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5064bool
5065atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5066                                        shared_ptr<_Tp> __w, memory_order, memory_order)
5067{
5068    return atomic_compare_exchange_strong(__p, __v, __w);
5069}
5070
5071template <class _Tp>
5072inline _LIBCPP_INLINE_VISIBILITY
5073_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5074bool
5075atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5076                                      shared_ptr<_Tp> __w, memory_order, memory_order)
5077{
5078    return atomic_compare_exchange_weak(__p, __v, __w);
5079}
5080
5081#endif  // !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
5082
5083//enum class
5084#if defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE)
5085# ifndef _LIBCPP_CXX03_LANG
5086enum class pointer_safety : unsigned char {
5087  relaxed,
5088  preferred,
5089  strict
5090};
5091# endif
5092#else
5093struct _LIBCPP_TYPE_VIS pointer_safety
5094{
5095    enum __lx
5096    {
5097        relaxed,
5098        preferred,
5099        strict
5100    };
5101
5102    __lx __v_;
5103
5104    _LIBCPP_INLINE_VISIBILITY
5105    pointer_safety() : __v_() {}
5106
5107    _LIBCPP_INLINE_VISIBILITY
5108    pointer_safety(__lx __v) : __v_(__v) {}
5109    _LIBCPP_INLINE_VISIBILITY
5110    operator int() const {return __v_;}
5111};
5112#endif
5113
5114#if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) && \
5115    defined(_LIBCPP_BUILDING_LIBRARY)
5116_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
5117#else
5118// This function is only offered in C++03 under ABI v1.
5119# if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) || !defined(_LIBCPP_CXX03_LANG)
5120inline _LIBCPP_INLINE_VISIBILITY
5121pointer_safety get_pointer_safety() _NOEXCEPT {
5122  return pointer_safety::relaxed;
5123}
5124# endif
5125#endif
5126
5127
5128_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
5129_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
5130_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
5131_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
5132
5133template <class _Tp>
5134inline _LIBCPP_INLINE_VISIBILITY
5135_Tp*
5136undeclare_reachable(_Tp* __p)
5137{
5138    return static_cast<_Tp*>(__undeclare_reachable(__p));
5139}
5140
5141_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
5142
5143// --- Helper for container swap --
5144template <typename _Alloc>
5145inline _LIBCPP_INLINE_VISIBILITY
5146void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
5147#if _LIBCPP_STD_VER >= 14
5148    _NOEXCEPT
5149#else
5150    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5151#endif
5152{
5153    __swap_allocator(__a1, __a2,
5154      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
5155}
5156
5157template <typename _Alloc>
5158_LIBCPP_INLINE_VISIBILITY
5159void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
5160#if _LIBCPP_STD_VER >= 14
5161    _NOEXCEPT
5162#else
5163    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5164#endif
5165{
5166    using _VSTD::swap;
5167    swap(__a1, __a2);
5168}
5169
5170template <typename _Alloc>
5171inline _LIBCPP_INLINE_VISIBILITY
5172void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
5173
5174template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
5175struct __noexcept_move_assign_container : public integral_constant<bool,
5176    _Traits::propagate_on_container_move_assignment::value
5177#if _LIBCPP_STD_VER > 14
5178        || _Traits::is_always_equal::value
5179#else
5180        && is_nothrow_move_assignable<_Alloc>::value
5181#endif
5182    > {};
5183
5184
5185#ifndef _LIBCPP_HAS_NO_VARIADICS
5186template <class _Tp, class _Alloc>
5187struct __temp_value {
5188    typedef allocator_traits<_Alloc> _Traits;
5189
5190    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
5191    _Alloc &__a;
5192
5193    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
5194    _Tp &   get() { return *__addr(); }
5195
5196    template<class... _Args>
5197    _LIBCPP_NO_CFI
5198    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
5199      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
5200                         _VSTD::forward<_Args>(__args)...);
5201    }
5202
5203    ~__temp_value() { _Traits::destroy(__a, __addr()); }
5204    };
5205#endif
5206
5207template<typename _Alloc, typename = void, typename = void>
5208struct __is_allocator : false_type {};
5209
5210template<typename _Alloc>
5211struct __is_allocator<_Alloc,
5212       typename __void_t<typename _Alloc::value_type>::type,
5213       typename __void_t<decltype(_VSTD::declval<_Alloc&>().allocate(size_t(0)))>::type
5214     >
5215   : true_type {};
5216
5217// __builtin_new_allocator -- A non-templated helper for allocating and
5218// deallocating memory using __builtin_operator_new and
5219// __builtin_operator_delete. It should be used in preference to
5220// `std::allocator<T>` to avoid additional instantiations.
5221struct __builtin_new_allocator {
5222  struct __builtin_new_deleter {
5223    typedef void* pointer_type;
5224
5225    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
5226        : __size_(__size), __align_(__align) {}
5227
5228    void operator()(void* p) const _NOEXCEPT {
5229        std::__libcpp_deallocate(p, __size_, __align_);
5230    }
5231
5232   private:
5233    size_t __size_;
5234    size_t __align_;
5235  };
5236
5237  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
5238
5239  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
5240      return __holder_t(std::__libcpp_allocate(__s, __align),
5241                     __builtin_new_deleter(__s, __align));
5242  }
5243
5244  static void __deallocate_bytes(void* __p, size_t __s,
5245                                 size_t __align) _NOEXCEPT {
5246      std::__libcpp_deallocate(__p, __s, __align);
5247  }
5248
5249  template <class _Tp>
5250  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5251  static __holder_t __allocate_type(size_t __n) {
5252      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5253  }
5254
5255  template <class _Tp>
5256  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5257  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
5258      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5259  }
5260};
5261
5262
5263_LIBCPP_END_NAMESPACE_STD
5264
5265_LIBCPP_POP_MACROS
5266
5267#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
5268#   include <__pstl_memory>
5269#endif
5270
5271#endif  // _LIBCPP_MEMORY
5272