xref: /llvm-project-15.0.7/libcxx/include/memory (revision 060c8e08)
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;
119    typedef ptrdiff_t difference_type;
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    typedef size_t     size_type;
1752    typedef ptrdiff_t  difference_type;
1753#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
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    typedef size_t     size_type;
1820    typedef ptrdiff_t  difference_type;
1821#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
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    template <class _Up, class... _Args>
1870        _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1871        void
1872        construct(_Up* __p, _Args&&... __args)
1873        {
1874            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1875        }
1876
1877    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1878#endif
1879};
1880
1881template <class _Tp, class _Up>
1882inline _LIBCPP_INLINE_VISIBILITY
1883bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
1884
1885template <class _Tp, class _Up>
1886inline _LIBCPP_INLINE_VISIBILITY
1887bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
1888
1889template <class _OutputIterator, class _Tp>
1890class _LIBCPP_TEMPLATE_VIS raw_storage_iterator
1891    : public iterator<output_iterator_tag,
1892                      _Tp,                                         // purposefully not C++03
1893                      ptrdiff_t,                                   // purposefully not C++03
1894                      _Tp*,                                        // purposefully not C++03
1895                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
1896{
1897private:
1898    _OutputIterator __x_;
1899public:
1900    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
1901    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
1902    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
1903        {::new(_VSTD::addressof(*__x_)) _Tp(__element); return *this;}
1904#if _LIBCPP_STD_VER >= 14
1905    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
1906        {::new(_VSTD::addressof(*__x_)) _Tp(_VSTD::move(__element)); return *this;}
1907#endif
1908    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
1909    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
1910        {raw_storage_iterator __t(*this); ++__x_; return __t;}
1911#if _LIBCPP_STD_VER >= 14
1912    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
1913#endif
1914};
1915
1916template <class _Tp>
1917_LIBCPP_NODISCARD_EXT _LIBCPP_NO_CFI
1918pair<_Tp*, ptrdiff_t>
1919get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
1920{
1921    pair<_Tp*, ptrdiff_t> __r(0, 0);
1922    const ptrdiff_t __m = (~ptrdiff_t(0) ^
1923                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
1924                           / sizeof(_Tp);
1925    if (__n > __m)
1926        __n = __m;
1927    while (__n > 0)
1928    {
1929#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
1930    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
1931        {
1932            std::align_val_t __al =
1933                std::align_val_t(std::alignment_of<_Tp>::value);
1934            __r.first = static_cast<_Tp*>(::operator new(
1935                __n * sizeof(_Tp), __al, nothrow));
1936        } else {
1937            __r.first = static_cast<_Tp*>(::operator new(
1938                __n * sizeof(_Tp), nothrow));
1939        }
1940#else
1941    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
1942        {
1943            // Since aligned operator new is unavailable, return an empty
1944            // buffer rather than one with invalid alignment.
1945            return __r;
1946        }
1947
1948        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
1949#endif
1950
1951        if (__r.first)
1952        {
1953            __r.second = __n;
1954            break;
1955        }
1956        __n /= 2;
1957    }
1958    return __r;
1959}
1960
1961template <class _Tp>
1962inline _LIBCPP_INLINE_VISIBILITY
1963void return_temporary_buffer(_Tp* __p) _NOEXCEPT
1964{
1965  _VSTD::__libcpp_deallocate_unsized((void*)__p, _LIBCPP_ALIGNOF(_Tp));
1966}
1967
1968#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
1969template <class _Tp>
1970struct _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr_ref
1971{
1972    _Tp* __ptr_;
1973};
1974
1975template<class _Tp>
1976class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr
1977{
1978private:
1979    _Tp* __ptr_;
1980public:
1981    typedef _Tp element_type;
1982
1983    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) _NOEXCEPT : __ptr_(__p) {}
1984    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) _NOEXCEPT : __ptr_(__p.release()) {}
1985    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) _NOEXCEPT
1986        : __ptr_(__p.release()) {}
1987    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) _NOEXCEPT
1988        {reset(__p.release()); return *this;}
1989    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) _NOEXCEPT
1990        {reset(__p.release()); return *this;}
1991    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) _NOEXCEPT
1992        {reset(__p.__ptr_); return *this;}
1993    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() _NOEXCEPT {delete __ptr_;}
1994
1995    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const _NOEXCEPT
1996        {return *__ptr_;}
1997    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const _NOEXCEPT {return __ptr_;}
1998    _LIBCPP_INLINE_VISIBILITY _Tp* get() const _NOEXCEPT {return __ptr_;}
1999    _LIBCPP_INLINE_VISIBILITY _Tp* release() _NOEXCEPT
2000    {
2001        _Tp* __t = __ptr_;
2002        __ptr_ = 0;
2003        return __t;
2004    }
2005    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) _NOEXCEPT
2006    {
2007        if (__ptr_ != __p)
2008            delete __ptr_;
2009        __ptr_ = __p;
2010    }
2011
2012    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) _NOEXCEPT : __ptr_(__p.__ptr_) {}
2013    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() _NOEXCEPT
2014        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
2015    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() _NOEXCEPT
2016        {return auto_ptr<_Up>(release());}
2017};
2018
2019template <>
2020class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr<void>
2021{
2022public:
2023    typedef void element_type;
2024};
2025#endif
2026
2027// Tag used to default initialize one or both of the pair's elements.
2028struct __default_init_tag {};
2029struct __value_init_tag {};
2030
2031template <class _Tp, int _Idx,
2032          bool _CanBeEmptyBase =
2033              is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value>
2034struct __compressed_pair_elem {
2035  typedef _Tp _ParamT;
2036  typedef _Tp& reference;
2037  typedef const _Tp& const_reference;
2038
2039  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2040  __compressed_pair_elem(__default_init_tag) {}
2041  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2042  __compressed_pair_elem(__value_init_tag) : __value_() {}
2043
2044  template <class _Up, class = typename enable_if<
2045      !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2046  >::type>
2047  _LIBCPP_INLINE_VISIBILITY
2048  _LIBCPP_CONSTEXPR explicit
2049  __compressed_pair_elem(_Up&& __u)
2050      : __value_(_VSTD::forward<_Up>(__u))
2051    {
2052    }
2053
2054
2055#ifndef _LIBCPP_CXX03_LANG
2056  template <class... _Args, size_t... _Indexes>
2057  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2058  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2059                         __tuple_indices<_Indexes...>)
2060      : __value_(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2061#endif
2062
2063
2064  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return __value_; }
2065  _LIBCPP_INLINE_VISIBILITY
2066  const_reference __get() const _NOEXCEPT { return __value_; }
2067
2068private:
2069  _Tp __value_;
2070};
2071
2072template <class _Tp, int _Idx>
2073struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp {
2074  typedef _Tp _ParamT;
2075  typedef _Tp& reference;
2076  typedef const _Tp& const_reference;
2077  typedef _Tp __value_type;
2078
2079  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR __compressed_pair_elem() = default;
2080  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2081  __compressed_pair_elem(__default_init_tag) {}
2082  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2083  __compressed_pair_elem(__value_init_tag) : __value_type() {}
2084
2085  template <class _Up, class = typename enable_if<
2086        !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2087  >::type>
2088  _LIBCPP_INLINE_VISIBILITY
2089  _LIBCPP_CONSTEXPR explicit
2090  __compressed_pair_elem(_Up&& __u)
2091      : __value_type(_VSTD::forward<_Up>(__u))
2092  {}
2093
2094#ifndef _LIBCPP_CXX03_LANG
2095  template <class... _Args, size_t... _Indexes>
2096  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2097  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2098                         __tuple_indices<_Indexes...>)
2099      : __value_type(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2100#endif
2101
2102  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return *this; }
2103  _LIBCPP_INLINE_VISIBILITY
2104  const_reference __get() const _NOEXCEPT { return *this; }
2105};
2106
2107template <class _T1, class _T2>
2108class __compressed_pair : private __compressed_pair_elem<_T1, 0>,
2109                          private __compressed_pair_elem<_T2, 1> {
2110  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T1, 0> _Base1;
2111  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T2, 1> _Base2;
2112
2113  // NOTE: This static assert should never fire because __compressed_pair
2114  // is *almost never* used in a scenario where it's possible for T1 == T2.
2115  // (The exception is std::function where it is possible that the function
2116  //  object and the allocator have the same type).
2117  static_assert((!is_same<_T1, _T2>::value),
2118    "__compressed_pair cannot be instantated when T1 and T2 are the same type; "
2119    "The current implementation is NOT ABI-compatible with the previous "
2120    "implementation for this configuration");
2121
2122public:
2123    template <bool _Dummy = true,
2124      class = typename enable_if<
2125          __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
2126          __dependent_type<is_default_constructible<_T2>, _Dummy>::value
2127      >::type
2128  >
2129  _LIBCPP_INLINE_VISIBILITY
2130  _LIBCPP_CONSTEXPR __compressed_pair() : _Base1(__value_init_tag()), _Base2(__value_init_tag()) {}
2131
2132  template <class _U1, class _U2>
2133  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2134  __compressed_pair(_U1&& __t1, _U2&& __t2)
2135      : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {}
2136
2137#ifndef _LIBCPP_CXX03_LANG
2138  template <class... _Args1, class... _Args2>
2139  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2140  __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
2141                    tuple<_Args2...> __second_args)
2142      : _Base1(__pc, _VSTD::move(__first_args),
2143               typename __make_tuple_indices<sizeof...(_Args1)>::type()),
2144        _Base2(__pc, _VSTD::move(__second_args),
2145               typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}
2146#endif
2147
2148  _LIBCPP_INLINE_VISIBILITY
2149  typename _Base1::reference first() _NOEXCEPT {
2150    return static_cast<_Base1&>(*this).__get();
2151  }
2152
2153  _LIBCPP_INLINE_VISIBILITY
2154  typename _Base1::const_reference first() const _NOEXCEPT {
2155    return static_cast<_Base1 const&>(*this).__get();
2156  }
2157
2158  _LIBCPP_INLINE_VISIBILITY
2159  typename _Base2::reference second() _NOEXCEPT {
2160    return static_cast<_Base2&>(*this).__get();
2161  }
2162
2163  _LIBCPP_INLINE_VISIBILITY
2164  typename _Base2::const_reference second() const _NOEXCEPT {
2165    return static_cast<_Base2 const&>(*this).__get();
2166  }
2167
2168  _LIBCPP_INLINE_VISIBILITY
2169  void swap(__compressed_pair& __x)
2170    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2171               __is_nothrow_swappable<_T2>::value)
2172  {
2173    using std::swap;
2174    swap(first(), __x.first());
2175    swap(second(), __x.second());
2176  }
2177};
2178
2179template <class _T1, class _T2>
2180inline _LIBCPP_INLINE_VISIBILITY
2181void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
2182    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2183               __is_nothrow_swappable<_T2>::value) {
2184  __x.swap(__y);
2185}
2186
2187// default_delete
2188
2189template <class _Tp>
2190struct _LIBCPP_TEMPLATE_VIS default_delete {
2191    static_assert(!is_function<_Tp>::value,
2192                  "default_delete cannot be instantiated for function types");
2193#ifndef _LIBCPP_CXX03_LANG
2194  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2195#else
2196  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2197#endif
2198  template <class _Up>
2199  _LIBCPP_INLINE_VISIBILITY
2200  default_delete(const default_delete<_Up>&,
2201                 typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* =
2202                     0) _NOEXCEPT {}
2203
2204  _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __ptr) const _NOEXCEPT {
2205    static_assert(sizeof(_Tp) > 0,
2206                  "default_delete can not delete incomplete type");
2207    static_assert(!is_void<_Tp>::value,
2208                  "default_delete can not delete incomplete type");
2209    delete __ptr;
2210  }
2211};
2212
2213template <class _Tp>
2214struct _LIBCPP_TEMPLATE_VIS default_delete<_Tp[]> {
2215private:
2216  template <class _Up>
2217  struct _EnableIfConvertible
2218      : enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value> {};
2219
2220public:
2221#ifndef _LIBCPP_CXX03_LANG
2222  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2223#else
2224  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2225#endif
2226
2227  template <class _Up>
2228  _LIBCPP_INLINE_VISIBILITY
2229  default_delete(const default_delete<_Up[]>&,
2230                 typename _EnableIfConvertible<_Up>::type* = 0) _NOEXCEPT {}
2231
2232  template <class _Up>
2233  _LIBCPP_INLINE_VISIBILITY
2234  typename _EnableIfConvertible<_Up>::type
2235  operator()(_Up* __ptr) const _NOEXCEPT {
2236    static_assert(sizeof(_Tp) > 0,
2237                  "default_delete can not delete incomplete type");
2238    static_assert(!is_void<_Tp>::value,
2239                  "default_delete can not delete void type");
2240    delete[] __ptr;
2241  }
2242};
2243
2244template <class _Deleter>
2245struct __unique_ptr_deleter_sfinae {
2246  static_assert(!is_reference<_Deleter>::value, "incorrect specialization");
2247  typedef const _Deleter& __lval_ref_type;
2248  typedef _Deleter&& __good_rval_ref_type;
2249  typedef true_type __enable_rval_overload;
2250};
2251
2252template <class _Deleter>
2253struct __unique_ptr_deleter_sfinae<_Deleter const&> {
2254  typedef const _Deleter& __lval_ref_type;
2255  typedef const _Deleter&& __bad_rval_ref_type;
2256  typedef false_type __enable_rval_overload;
2257};
2258
2259template <class _Deleter>
2260struct __unique_ptr_deleter_sfinae<_Deleter&> {
2261  typedef _Deleter& __lval_ref_type;
2262  typedef _Deleter&& __bad_rval_ref_type;
2263  typedef false_type __enable_rval_overload;
2264};
2265
2266#if defined(_LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI)
2267#  define _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI __attribute__((trivial_abi))
2268#else
2269#  define _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI
2270#endif
2271
2272template <class _Tp, class _Dp = default_delete<_Tp> >
2273class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS unique_ptr {
2274public:
2275  typedef _Tp element_type;
2276  typedef _Dp deleter_type;
2277  typedef _LIBCPP_NODEBUG_TYPE typename __pointer_type<_Tp, deleter_type>::type pointer;
2278
2279  static_assert(!is_rvalue_reference<deleter_type>::value,
2280                "the specified deleter type cannot be an rvalue reference");
2281
2282private:
2283  __compressed_pair<pointer, deleter_type> __ptr_;
2284
2285  struct __nat { int __for_bool_; };
2286
2287  typedef _LIBCPP_NODEBUG_TYPE __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2288
2289  template <bool _Dummy>
2290  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2291      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2292
2293  template <bool _Dummy>
2294  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2295      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2296
2297  template <bool _Dummy>
2298  using _BadRValRefType _LIBCPP_NODEBUG_TYPE  =
2299      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2300
2301  template <bool _Dummy, class _Deleter = typename __dependent_type<
2302                             __identity<deleter_type>, _Dummy>::type>
2303  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE =
2304      typename enable_if<is_default_constructible<_Deleter>::value &&
2305                         !is_pointer<_Deleter>::value>::type;
2306
2307  template <class _ArgType>
2308  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2309      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2310
2311  template <class _UPtr, class _Up>
2312  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2313      is_convertible<typename _UPtr::pointer, pointer>::value &&
2314      !is_array<_Up>::value
2315  >::type;
2316
2317  template <class _UDel>
2318  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2319      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2320      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2321    >::type;
2322
2323  template <class _UDel>
2324  using _EnableIfDeleterAssignable = typename enable_if<
2325      is_assignable<_Dp&, _UDel&&>::value
2326    >::type;
2327
2328public:
2329  template <bool _Dummy = true,
2330            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2331  _LIBCPP_INLINE_VISIBILITY
2332  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2333
2334  template <bool _Dummy = true,
2335            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2336  _LIBCPP_INLINE_VISIBILITY
2337  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2338
2339  template <bool _Dummy = true,
2340            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2341  _LIBCPP_INLINE_VISIBILITY
2342  explicit unique_ptr(pointer __p) _NOEXCEPT : __ptr_(__p, __default_init_tag()) {}
2343
2344  template <bool _Dummy = true,
2345            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2346  _LIBCPP_INLINE_VISIBILITY
2347  unique_ptr(pointer __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2348      : __ptr_(__p, __d) {}
2349
2350  template <bool _Dummy = true,
2351            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2352  _LIBCPP_INLINE_VISIBILITY
2353  unique_ptr(pointer __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2354      : __ptr_(__p, _VSTD::move(__d)) {
2355    static_assert(!is_reference<deleter_type>::value,
2356                  "rvalue deleter bound to reference");
2357  }
2358
2359  template <bool _Dummy = true,
2360            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> > >
2361  _LIBCPP_INLINE_VISIBILITY
2362  unique_ptr(pointer __p, _BadRValRefType<_Dummy> __d) = delete;
2363
2364  _LIBCPP_INLINE_VISIBILITY
2365  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2366      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2367  }
2368
2369  template <class _Up, class _Ep,
2370      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2371      class = _EnableIfDeleterConvertible<_Ep>
2372  >
2373  _LIBCPP_INLINE_VISIBILITY
2374  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2375      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
2376
2377#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2378  template <class _Up>
2379  _LIBCPP_INLINE_VISIBILITY
2380  unique_ptr(auto_ptr<_Up>&& __p,
2381             typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2382                                    is_same<_Dp, default_delete<_Tp> >::value,
2383                                __nat>::type = __nat()) _NOEXCEPT
2384      : __ptr_(__p.release(), __default_init_tag()) {}
2385#endif
2386
2387  _LIBCPP_INLINE_VISIBILITY
2388  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2389    reset(__u.release());
2390    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2391    return *this;
2392  }
2393
2394  template <class _Up, class _Ep,
2395      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2396      class = _EnableIfDeleterAssignable<_Ep>
2397  >
2398  _LIBCPP_INLINE_VISIBILITY
2399  unique_ptr& operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2400    reset(__u.release());
2401    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2402    return *this;
2403  }
2404
2405#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2406  template <class _Up>
2407  _LIBCPP_INLINE_VISIBILITY
2408      typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2409                             is_same<_Dp, default_delete<_Tp> >::value,
2410                         unique_ptr&>::type
2411      operator=(auto_ptr<_Up> __p) {
2412    reset(__p.release());
2413    return *this;
2414  }
2415#endif
2416
2417#ifdef _LIBCPP_CXX03_LANG
2418  unique_ptr(unique_ptr const&) = delete;
2419  unique_ptr& operator=(unique_ptr const&) = delete;
2420#endif
2421
2422
2423  _LIBCPP_INLINE_VISIBILITY
2424  ~unique_ptr() { reset(); }
2425
2426  _LIBCPP_INLINE_VISIBILITY
2427  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2428    reset();
2429    return *this;
2430  }
2431
2432  _LIBCPP_INLINE_VISIBILITY
2433  typename add_lvalue_reference<_Tp>::type
2434  operator*() const {
2435    return *__ptr_.first();
2436  }
2437  _LIBCPP_INLINE_VISIBILITY
2438  pointer operator->() const _NOEXCEPT {
2439    return __ptr_.first();
2440  }
2441  _LIBCPP_INLINE_VISIBILITY
2442  pointer get() const _NOEXCEPT {
2443    return __ptr_.first();
2444  }
2445  _LIBCPP_INLINE_VISIBILITY
2446  deleter_type& get_deleter() _NOEXCEPT {
2447    return __ptr_.second();
2448  }
2449  _LIBCPP_INLINE_VISIBILITY
2450  const deleter_type& get_deleter() const _NOEXCEPT {
2451    return __ptr_.second();
2452  }
2453  _LIBCPP_INLINE_VISIBILITY
2454  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2455    return __ptr_.first() != nullptr;
2456  }
2457
2458  _LIBCPP_INLINE_VISIBILITY
2459  pointer release() _NOEXCEPT {
2460    pointer __t = __ptr_.first();
2461    __ptr_.first() = pointer();
2462    return __t;
2463  }
2464
2465  _LIBCPP_INLINE_VISIBILITY
2466  void reset(pointer __p = pointer()) _NOEXCEPT {
2467    pointer __tmp = __ptr_.first();
2468    __ptr_.first() = __p;
2469    if (__tmp)
2470      __ptr_.second()(__tmp);
2471  }
2472
2473  _LIBCPP_INLINE_VISIBILITY
2474  void swap(unique_ptr& __u) _NOEXCEPT {
2475    __ptr_.swap(__u.__ptr_);
2476  }
2477};
2478
2479
2480template <class _Tp, class _Dp>
2481class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
2482public:
2483  typedef _Tp element_type;
2484  typedef _Dp deleter_type;
2485  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2486
2487private:
2488  __compressed_pair<pointer, deleter_type> __ptr_;
2489
2490  template <class _From>
2491  struct _CheckArrayPointerConversion : is_same<_From, pointer> {};
2492
2493  template <class _FromElem>
2494  struct _CheckArrayPointerConversion<_FromElem*>
2495      : integral_constant<bool,
2496          is_same<_FromElem*, pointer>::value ||
2497            (is_same<pointer, element_type*>::value &&
2498             is_convertible<_FromElem(*)[], element_type(*)[]>::value)
2499      >
2500  {};
2501
2502  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2503
2504  template <bool _Dummy>
2505  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2506      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2507
2508  template <bool _Dummy>
2509  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2510      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2511
2512  template <bool _Dummy>
2513  using _BadRValRefType _LIBCPP_NODEBUG_TYPE =
2514      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2515
2516  template <bool _Dummy, class _Deleter = typename __dependent_type<
2517                             __identity<deleter_type>, _Dummy>::type>
2518  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE  =
2519      typename enable_if<is_default_constructible<_Deleter>::value &&
2520                         !is_pointer<_Deleter>::value>::type;
2521
2522  template <class _ArgType>
2523  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2524      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2525
2526  template <class _Pp>
2527  using _EnableIfPointerConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2528      _CheckArrayPointerConversion<_Pp>::value
2529  >::type;
2530
2531  template <class _UPtr, class _Up,
2532        class _ElemT = typename _UPtr::element_type>
2533  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2534      is_array<_Up>::value &&
2535      is_same<pointer, element_type*>::value &&
2536      is_same<typename _UPtr::pointer, _ElemT*>::value &&
2537      is_convertible<_ElemT(*)[], element_type(*)[]>::value
2538    >::type;
2539
2540  template <class _UDel>
2541  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2542      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2543      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2544    >::type;
2545
2546  template <class _UDel>
2547  using _EnableIfDeleterAssignable _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2548      is_assignable<_Dp&, _UDel&&>::value
2549    >::type;
2550
2551public:
2552  template <bool _Dummy = true,
2553            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2554  _LIBCPP_INLINE_VISIBILITY
2555  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2556
2557  template <bool _Dummy = true,
2558            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2559  _LIBCPP_INLINE_VISIBILITY
2560  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2561
2562  template <class _Pp, bool _Dummy = true,
2563            class = _EnableIfDeleterDefaultConstructible<_Dummy>,
2564            class = _EnableIfPointerConvertible<_Pp> >
2565  _LIBCPP_INLINE_VISIBILITY
2566  explicit unique_ptr(_Pp __p) _NOEXCEPT
2567      : __ptr_(__p, __default_init_tag()) {}
2568
2569  template <class _Pp, bool _Dummy = true,
2570            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> >,
2571            class = _EnableIfPointerConvertible<_Pp> >
2572  _LIBCPP_INLINE_VISIBILITY
2573  unique_ptr(_Pp __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2574      : __ptr_(__p, __d) {}
2575
2576  template <bool _Dummy = true,
2577            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2578  _LIBCPP_INLINE_VISIBILITY
2579  unique_ptr(nullptr_t, _LValRefType<_Dummy> __d) _NOEXCEPT
2580      : __ptr_(nullptr, __d) {}
2581
2582  template <class _Pp, bool _Dummy = true,
2583            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> >,
2584            class = _EnableIfPointerConvertible<_Pp> >
2585  _LIBCPP_INLINE_VISIBILITY
2586  unique_ptr(_Pp __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2587      : __ptr_(__p, _VSTD::move(__d)) {
2588    static_assert(!is_reference<deleter_type>::value,
2589                  "rvalue deleter bound to reference");
2590  }
2591
2592  template <bool _Dummy = true,
2593            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2594  _LIBCPP_INLINE_VISIBILITY
2595  unique_ptr(nullptr_t, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2596      : __ptr_(nullptr, _VSTD::move(__d)) {
2597    static_assert(!is_reference<deleter_type>::value,
2598                  "rvalue deleter bound to reference");
2599  }
2600
2601  template <class _Pp, bool _Dummy = true,
2602            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> >,
2603            class = _EnableIfPointerConvertible<_Pp> >
2604  _LIBCPP_INLINE_VISIBILITY
2605  unique_ptr(_Pp __p, _BadRValRefType<_Dummy> __d) = delete;
2606
2607  _LIBCPP_INLINE_VISIBILITY
2608  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2609      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2610  }
2611
2612  _LIBCPP_INLINE_VISIBILITY
2613  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2614    reset(__u.release());
2615    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2616    return *this;
2617  }
2618
2619  template <class _Up, class _Ep,
2620      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2621      class = _EnableIfDeleterConvertible<_Ep>
2622  >
2623  _LIBCPP_INLINE_VISIBILITY
2624  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2625      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {
2626  }
2627
2628  template <class _Up, class _Ep,
2629      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2630      class = _EnableIfDeleterAssignable<_Ep>
2631  >
2632  _LIBCPP_INLINE_VISIBILITY
2633  unique_ptr&
2634  operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2635    reset(__u.release());
2636    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2637    return *this;
2638  }
2639
2640#ifdef _LIBCPP_CXX03_LANG
2641  unique_ptr(unique_ptr const&) = delete;
2642  unique_ptr& operator=(unique_ptr const&) = delete;
2643#endif
2644
2645public:
2646  _LIBCPP_INLINE_VISIBILITY
2647  ~unique_ptr() { reset(); }
2648
2649  _LIBCPP_INLINE_VISIBILITY
2650  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2651    reset();
2652    return *this;
2653  }
2654
2655  _LIBCPP_INLINE_VISIBILITY
2656  typename add_lvalue_reference<_Tp>::type
2657  operator[](size_t __i) const {
2658    return __ptr_.first()[__i];
2659  }
2660  _LIBCPP_INLINE_VISIBILITY
2661  pointer get() const _NOEXCEPT {
2662    return __ptr_.first();
2663  }
2664
2665  _LIBCPP_INLINE_VISIBILITY
2666  deleter_type& get_deleter() _NOEXCEPT {
2667    return __ptr_.second();
2668  }
2669
2670  _LIBCPP_INLINE_VISIBILITY
2671  const deleter_type& get_deleter() const _NOEXCEPT {
2672    return __ptr_.second();
2673  }
2674  _LIBCPP_INLINE_VISIBILITY
2675  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2676    return __ptr_.first() != nullptr;
2677  }
2678
2679  _LIBCPP_INLINE_VISIBILITY
2680  pointer release() _NOEXCEPT {
2681    pointer __t = __ptr_.first();
2682    __ptr_.first() = pointer();
2683    return __t;
2684  }
2685
2686  template <class _Pp>
2687  _LIBCPP_INLINE_VISIBILITY
2688  typename enable_if<
2689      _CheckArrayPointerConversion<_Pp>::value
2690  >::type
2691  reset(_Pp __p) _NOEXCEPT {
2692    pointer __tmp = __ptr_.first();
2693    __ptr_.first() = __p;
2694    if (__tmp)
2695      __ptr_.second()(__tmp);
2696  }
2697
2698  _LIBCPP_INLINE_VISIBILITY
2699  void reset(nullptr_t = nullptr) _NOEXCEPT {
2700    pointer __tmp = __ptr_.first();
2701    __ptr_.first() = nullptr;
2702    if (__tmp)
2703      __ptr_.second()(__tmp);
2704  }
2705
2706  _LIBCPP_INLINE_VISIBILITY
2707  void swap(unique_ptr& __u) _NOEXCEPT {
2708    __ptr_.swap(__u.__ptr_);
2709  }
2710
2711};
2712
2713template <class _Tp, class _Dp>
2714inline _LIBCPP_INLINE_VISIBILITY
2715typename enable_if<
2716    __is_swappable<_Dp>::value,
2717    void
2718>::type
2719swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
2720
2721template <class _T1, class _D1, class _T2, class _D2>
2722inline _LIBCPP_INLINE_VISIBILITY
2723bool
2724operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
2725
2726template <class _T1, class _D1, class _T2, class _D2>
2727inline _LIBCPP_INLINE_VISIBILITY
2728bool
2729operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
2730
2731template <class _T1, class _D1, class _T2, class _D2>
2732inline _LIBCPP_INLINE_VISIBILITY
2733bool
2734operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
2735{
2736    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2737    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
2738    typedef typename common_type<_P1, _P2>::type _Vp;
2739    return less<_Vp>()(__x.get(), __y.get());
2740}
2741
2742template <class _T1, class _D1, class _T2, class _D2>
2743inline _LIBCPP_INLINE_VISIBILITY
2744bool
2745operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
2746
2747template <class _T1, class _D1, class _T2, class _D2>
2748inline _LIBCPP_INLINE_VISIBILITY
2749bool
2750operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
2751
2752template <class _T1, class _D1, class _T2, class _D2>
2753inline _LIBCPP_INLINE_VISIBILITY
2754bool
2755operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
2756
2757template <class _T1, class _D1>
2758inline _LIBCPP_INLINE_VISIBILITY
2759bool
2760operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2761{
2762    return !__x;
2763}
2764
2765template <class _T1, class _D1>
2766inline _LIBCPP_INLINE_VISIBILITY
2767bool
2768operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2769{
2770    return !__x;
2771}
2772
2773template <class _T1, class _D1>
2774inline _LIBCPP_INLINE_VISIBILITY
2775bool
2776operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2777{
2778    return static_cast<bool>(__x);
2779}
2780
2781template <class _T1, class _D1>
2782inline _LIBCPP_INLINE_VISIBILITY
2783bool
2784operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2785{
2786    return static_cast<bool>(__x);
2787}
2788
2789template <class _T1, class _D1>
2790inline _LIBCPP_INLINE_VISIBILITY
2791bool
2792operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2793{
2794    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2795    return less<_P1>()(__x.get(), nullptr);
2796}
2797
2798template <class _T1, class _D1>
2799inline _LIBCPP_INLINE_VISIBILITY
2800bool
2801operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2802{
2803    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2804    return less<_P1>()(nullptr, __x.get());
2805}
2806
2807template <class _T1, class _D1>
2808inline _LIBCPP_INLINE_VISIBILITY
2809bool
2810operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2811{
2812    return nullptr < __x;
2813}
2814
2815template <class _T1, class _D1>
2816inline _LIBCPP_INLINE_VISIBILITY
2817bool
2818operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2819{
2820    return __x < nullptr;
2821}
2822
2823template <class _T1, class _D1>
2824inline _LIBCPP_INLINE_VISIBILITY
2825bool
2826operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2827{
2828    return !(nullptr < __x);
2829}
2830
2831template <class _T1, class _D1>
2832inline _LIBCPP_INLINE_VISIBILITY
2833bool
2834operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2835{
2836    return !(__x < nullptr);
2837}
2838
2839template <class _T1, class _D1>
2840inline _LIBCPP_INLINE_VISIBILITY
2841bool
2842operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2843{
2844    return !(__x < nullptr);
2845}
2846
2847template <class _T1, class _D1>
2848inline _LIBCPP_INLINE_VISIBILITY
2849bool
2850operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2851{
2852    return !(nullptr < __x);
2853}
2854
2855#if _LIBCPP_STD_VER > 11
2856
2857template<class _Tp>
2858struct __unique_if
2859{
2860    typedef unique_ptr<_Tp> __unique_single;
2861};
2862
2863template<class _Tp>
2864struct __unique_if<_Tp[]>
2865{
2866    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
2867};
2868
2869template<class _Tp, size_t _Np>
2870struct __unique_if<_Tp[_Np]>
2871{
2872    typedef void __unique_array_known_bound;
2873};
2874
2875template<class _Tp, class... _Args>
2876inline _LIBCPP_INLINE_VISIBILITY
2877typename __unique_if<_Tp>::__unique_single
2878make_unique(_Args&&... __args)
2879{
2880    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
2881}
2882
2883template<class _Tp>
2884inline _LIBCPP_INLINE_VISIBILITY
2885typename __unique_if<_Tp>::__unique_array_unknown_bound
2886make_unique(size_t __n)
2887{
2888    typedef typename remove_extent<_Tp>::type _Up;
2889    return unique_ptr<_Tp>(new _Up[__n]());
2890}
2891
2892template<class _Tp, class... _Args>
2893    typename __unique_if<_Tp>::__unique_array_known_bound
2894    make_unique(_Args&&...) = delete;
2895
2896#endif  // _LIBCPP_STD_VER > 11
2897
2898template <class _Tp, class _Dp>
2899#ifdef _LIBCPP_CXX03_LANG
2900struct _LIBCPP_TEMPLATE_VIS hash<unique_ptr<_Tp, _Dp> >
2901#else
2902struct _LIBCPP_TEMPLATE_VIS hash<__enable_hash_helper<
2903    unique_ptr<_Tp, _Dp>, typename unique_ptr<_Tp, _Dp>::pointer> >
2904#endif
2905{
2906    typedef unique_ptr<_Tp, _Dp> argument_type;
2907    typedef size_t               result_type;
2908    _LIBCPP_INLINE_VISIBILITY
2909    result_type operator()(const argument_type& __ptr) const
2910    {
2911        typedef typename argument_type::pointer pointer;
2912        return hash<pointer>()(__ptr.get());
2913    }
2914};
2915
2916struct __destruct_n
2917{
2918private:
2919    size_t __size_;
2920
2921    template <class _Tp>
2922    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
2923        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
2924
2925    template <class _Tp>
2926    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
2927        {}
2928
2929    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
2930        {++__size_;}
2931    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
2932        {}
2933
2934    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
2935        {__size_ = __s;}
2936    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
2937        {}
2938public:
2939    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
2940        : __size_(__s) {}
2941
2942    template <class _Tp>
2943    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
2944        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
2945
2946    template <class _Tp>
2947    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
2948        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
2949
2950    template <class _Tp>
2951    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
2952        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
2953};
2954
2955template <class _Alloc>
2956class __allocator_destructor
2957{
2958    typedef _LIBCPP_NODEBUG_TYPE allocator_traits<_Alloc> __alloc_traits;
2959public:
2960    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::pointer pointer;
2961    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::size_type size_type;
2962private:
2963    _Alloc& __alloc_;
2964    size_type __s_;
2965public:
2966    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
2967             _NOEXCEPT
2968        : __alloc_(__a), __s_(__s) {}
2969    _LIBCPP_INLINE_VISIBILITY
2970    void operator()(pointer __p) _NOEXCEPT
2971        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
2972};
2973
2974template <class _InputIterator, class _ForwardIterator>
2975_ForwardIterator
2976uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
2977{
2978    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
2979#ifndef _LIBCPP_NO_EXCEPTIONS
2980    _ForwardIterator __s = __r;
2981    try
2982    {
2983#endif
2984        for (; __f != __l; ++__f, (void) ++__r)
2985            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
2986#ifndef _LIBCPP_NO_EXCEPTIONS
2987    }
2988    catch (...)
2989    {
2990        for (; __s != __r; ++__s)
2991            __s->~value_type();
2992        throw;
2993    }
2994#endif
2995    return __r;
2996}
2997
2998template <class _InputIterator, class _Size, class _ForwardIterator>
2999_ForwardIterator
3000uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
3001{
3002    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3003#ifndef _LIBCPP_NO_EXCEPTIONS
3004    _ForwardIterator __s = __r;
3005    try
3006    {
3007#endif
3008        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
3009            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3010#ifndef _LIBCPP_NO_EXCEPTIONS
3011    }
3012    catch (...)
3013    {
3014        for (; __s != __r; ++__s)
3015            __s->~value_type();
3016        throw;
3017    }
3018#endif
3019    return __r;
3020}
3021
3022template <class _ForwardIterator, class _Tp>
3023void
3024uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
3025{
3026    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3027#ifndef _LIBCPP_NO_EXCEPTIONS
3028    _ForwardIterator __s = __f;
3029    try
3030    {
3031#endif
3032        for (; __f != __l; ++__f)
3033            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3034#ifndef _LIBCPP_NO_EXCEPTIONS
3035    }
3036    catch (...)
3037    {
3038        for (; __s != __f; ++__s)
3039            __s->~value_type();
3040        throw;
3041    }
3042#endif
3043}
3044
3045template <class _ForwardIterator, class _Size, class _Tp>
3046_ForwardIterator
3047uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
3048{
3049    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3050#ifndef _LIBCPP_NO_EXCEPTIONS
3051    _ForwardIterator __s = __f;
3052    try
3053    {
3054#endif
3055        for (; __n > 0; ++__f, (void) --__n)
3056            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3057#ifndef _LIBCPP_NO_EXCEPTIONS
3058    }
3059    catch (...)
3060    {
3061        for (; __s != __f; ++__s)
3062            __s->~value_type();
3063        throw;
3064    }
3065#endif
3066    return __f;
3067}
3068
3069#if _LIBCPP_STD_VER > 14
3070
3071template <class _Tp>
3072inline _LIBCPP_INLINE_VISIBILITY
3073void destroy_at(_Tp* __loc) {
3074    _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
3075    __loc->~_Tp();
3076}
3077
3078template <class _ForwardIterator>
3079inline _LIBCPP_INLINE_VISIBILITY
3080void destroy(_ForwardIterator __first, _ForwardIterator __last) {
3081    for (; __first != __last; ++__first)
3082        _VSTD::destroy_at(_VSTD::addressof(*__first));
3083}
3084
3085template <class _ForwardIterator, class _Size>
3086inline _LIBCPP_INLINE_VISIBILITY
3087_ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
3088    for (; __n > 0; (void)++__first, --__n)
3089        _VSTD::destroy_at(_VSTD::addressof(*__first));
3090    return __first;
3091}
3092
3093template <class _ForwardIterator>
3094inline _LIBCPP_INLINE_VISIBILITY
3095void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
3096    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3097    auto __idx = __first;
3098#ifndef _LIBCPP_NO_EXCEPTIONS
3099    try {
3100#endif
3101    for (; __idx != __last; ++__idx)
3102        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3103#ifndef _LIBCPP_NO_EXCEPTIONS
3104    } catch (...) {
3105        _VSTD::destroy(__first, __idx);
3106        throw;
3107    }
3108#endif
3109}
3110
3111template <class _ForwardIterator, class _Size>
3112inline _LIBCPP_INLINE_VISIBILITY
3113_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
3114    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3115    auto __idx = __first;
3116#ifndef _LIBCPP_NO_EXCEPTIONS
3117    try {
3118#endif
3119    for (; __n > 0; (void)++__idx, --__n)
3120        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3121    return __idx;
3122#ifndef _LIBCPP_NO_EXCEPTIONS
3123    } catch (...) {
3124        _VSTD::destroy(__first, __idx);
3125        throw;
3126    }
3127#endif
3128}
3129
3130
3131template <class _ForwardIterator>
3132inline _LIBCPP_INLINE_VISIBILITY
3133void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
3134    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3135    auto __idx = __first;
3136#ifndef _LIBCPP_NO_EXCEPTIONS
3137    try {
3138#endif
3139    for (; __idx != __last; ++__idx)
3140        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3141#ifndef _LIBCPP_NO_EXCEPTIONS
3142    } catch (...) {
3143        _VSTD::destroy(__first, __idx);
3144        throw;
3145    }
3146#endif
3147}
3148
3149template <class _ForwardIterator, class _Size>
3150inline _LIBCPP_INLINE_VISIBILITY
3151_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
3152    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3153    auto __idx = __first;
3154#ifndef _LIBCPP_NO_EXCEPTIONS
3155    try {
3156#endif
3157    for (; __n > 0; (void)++__idx, --__n)
3158        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3159    return __idx;
3160#ifndef _LIBCPP_NO_EXCEPTIONS
3161    } catch (...) {
3162        _VSTD::destroy(__first, __idx);
3163        throw;
3164    }
3165#endif
3166}
3167
3168
3169template <class _InputIt, class _ForwardIt>
3170inline _LIBCPP_INLINE_VISIBILITY
3171_ForwardIt uninitialized_move(_InputIt __first, _InputIt __last, _ForwardIt __first_res) {
3172    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3173    auto __idx = __first_res;
3174#ifndef _LIBCPP_NO_EXCEPTIONS
3175    try {
3176#endif
3177    for (; __first != __last; (void)++__idx, ++__first)
3178        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3179    return __idx;
3180#ifndef _LIBCPP_NO_EXCEPTIONS
3181    } catch (...) {
3182        _VSTD::destroy(__first_res, __idx);
3183        throw;
3184    }
3185#endif
3186}
3187
3188template <class _InputIt, class _Size, class _ForwardIt>
3189inline _LIBCPP_INLINE_VISIBILITY
3190pair<_InputIt, _ForwardIt>
3191uninitialized_move_n(_InputIt __first, _Size __n, _ForwardIt __first_res) {
3192    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3193    auto __idx = __first_res;
3194#ifndef _LIBCPP_NO_EXCEPTIONS
3195    try {
3196#endif
3197    for (; __n > 0; ++__idx, (void)++__first, --__n)
3198        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3199    return {__first, __idx};
3200#ifndef _LIBCPP_NO_EXCEPTIONS
3201    } catch (...) {
3202        _VSTD::destroy(__first_res, __idx);
3203        throw;
3204    }
3205#endif
3206}
3207
3208
3209#endif // _LIBCPP_STD_VER > 14
3210
3211// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
3212// should be sufficient for thread safety.
3213// See https://bugs.llvm.org/show_bug.cgi?id=22803
3214#if defined(__clang__) && __has_builtin(__atomic_add_fetch)          \
3215                       && defined(__ATOMIC_RELAXED)                  \
3216                       && defined(__ATOMIC_ACQ_REL)
3217#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3218#elif defined(_LIBCPP_COMPILER_GCC)
3219#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3220#endif
3221
3222template <class _Tp>
3223inline _LIBCPP_INLINE_VISIBILITY _Tp
3224__libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT
3225{
3226#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3227    return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
3228#else
3229    return __t += 1;
3230#endif
3231}
3232
3233template <class _Tp>
3234inline _LIBCPP_INLINE_VISIBILITY _Tp
3235__libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT
3236{
3237#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3238    return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
3239#else
3240    return __t -= 1;
3241#endif
3242}
3243
3244class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
3245    : public std::exception
3246{
3247public:
3248    bad_weak_ptr() _NOEXCEPT = default;
3249    bad_weak_ptr(const bad_weak_ptr&) _NOEXCEPT = default;
3250    virtual ~bad_weak_ptr() _NOEXCEPT;
3251    virtual const char* what() const  _NOEXCEPT;
3252};
3253
3254_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
3255void __throw_bad_weak_ptr()
3256{
3257#ifndef _LIBCPP_NO_EXCEPTIONS
3258    throw bad_weak_ptr();
3259#else
3260    _VSTD::abort();
3261#endif
3262}
3263
3264template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr;
3265
3266class _LIBCPP_TYPE_VIS __shared_count
3267{
3268    __shared_count(const __shared_count&);
3269    __shared_count& operator=(const __shared_count&);
3270
3271protected:
3272    long __shared_owners_;
3273    virtual ~__shared_count();
3274private:
3275    virtual void __on_zero_shared() _NOEXCEPT = 0;
3276
3277public:
3278    _LIBCPP_INLINE_VISIBILITY
3279    explicit __shared_count(long __refs = 0) _NOEXCEPT
3280        : __shared_owners_(__refs) {}
3281
3282#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3283    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3284    void __add_shared() _NOEXCEPT;
3285    bool __release_shared() _NOEXCEPT;
3286#else
3287    _LIBCPP_INLINE_VISIBILITY
3288    void __add_shared() _NOEXCEPT {
3289      __libcpp_atomic_refcount_increment(__shared_owners_);
3290    }
3291    _LIBCPP_INLINE_VISIBILITY
3292    bool __release_shared() _NOEXCEPT {
3293      if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
3294        __on_zero_shared();
3295        return true;
3296      }
3297      return false;
3298    }
3299#endif
3300    _LIBCPP_INLINE_VISIBILITY
3301    long use_count() const _NOEXCEPT {
3302        return __libcpp_relaxed_load(&__shared_owners_) + 1;
3303    }
3304};
3305
3306class _LIBCPP_TYPE_VIS __shared_weak_count
3307    : private __shared_count
3308{
3309    long __shared_weak_owners_;
3310
3311public:
3312    _LIBCPP_INLINE_VISIBILITY
3313    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
3314        : __shared_count(__refs),
3315          __shared_weak_owners_(__refs) {}
3316protected:
3317    virtual ~__shared_weak_count();
3318
3319public:
3320#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3321    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3322    void __add_shared() _NOEXCEPT;
3323    void __add_weak() _NOEXCEPT;
3324    void __release_shared() _NOEXCEPT;
3325#else
3326    _LIBCPP_INLINE_VISIBILITY
3327    void __add_shared() _NOEXCEPT {
3328      __shared_count::__add_shared();
3329    }
3330    _LIBCPP_INLINE_VISIBILITY
3331    void __add_weak() _NOEXCEPT {
3332      __libcpp_atomic_refcount_increment(__shared_weak_owners_);
3333    }
3334    _LIBCPP_INLINE_VISIBILITY
3335    void __release_shared() _NOEXCEPT {
3336      if (__shared_count::__release_shared())
3337        __release_weak();
3338    }
3339#endif
3340    void __release_weak() _NOEXCEPT;
3341    _LIBCPP_INLINE_VISIBILITY
3342    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
3343    __shared_weak_count* lock() _NOEXCEPT;
3344
3345    // Define the function out only if we build static libc++ without RTTI.
3346    // Otherwise we may break clients who need to compile their projects with
3347    // -fno-rtti and yet link against a libc++.dylib compiled
3348    // without -fno-rtti.
3349#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
3350    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3351#endif
3352private:
3353    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
3354};
3355
3356template <class _Tp, class _Dp, class _Alloc>
3357class __shared_ptr_pointer
3358    : public __shared_weak_count
3359{
3360    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
3361public:
3362    _LIBCPP_INLINE_VISIBILITY
3363    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
3364        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
3365
3366#ifndef _LIBCPP_NO_RTTI
3367    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3368#endif
3369
3370private:
3371    virtual void __on_zero_shared() _NOEXCEPT;
3372    virtual void __on_zero_shared_weak() _NOEXCEPT;
3373};
3374
3375#ifndef _LIBCPP_NO_RTTI
3376
3377template <class _Tp, class _Dp, class _Alloc>
3378const void*
3379__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
3380{
3381    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr;
3382}
3383
3384#endif  // _LIBCPP_NO_RTTI
3385
3386template <class _Tp, class _Dp, class _Alloc>
3387void
3388__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
3389{
3390    __data_.first().second()(__data_.first().first());
3391    __data_.first().second().~_Dp();
3392}
3393
3394template <class _Tp, class _Dp, class _Alloc>
3395void
3396__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3397{
3398    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
3399    typedef allocator_traits<_Al> _ATraits;
3400    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3401
3402    _Al __a(__data_.second());
3403    __data_.second().~_Alloc();
3404    __a.deallocate(_PTraits::pointer_to(*this), 1);
3405}
3406
3407template <class _Tp, class _Alloc>
3408class __shared_ptr_emplace
3409    : public __shared_weak_count
3410{
3411    __compressed_pair<_Alloc, _Tp> __data_;
3412public:
3413
3414    _LIBCPP_INLINE_VISIBILITY
3415    __shared_ptr_emplace(_Alloc __a)
3416        :  __data_(_VSTD::move(__a), __value_init_tag()) {}
3417
3418
3419#ifndef _LIBCPP_HAS_NO_VARIADICS
3420    template <class ..._Args>
3421        _LIBCPP_INLINE_VISIBILITY
3422        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
3423            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
3424                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
3425#else  // _LIBCPP_HAS_NO_VARIADICS
3426
3427    template <class _A0>
3428        _LIBCPP_INLINE_VISIBILITY
3429        __shared_ptr_emplace(_Alloc __a, _A0& __a0)
3430            :  __data_(__a, _Tp(__a0)) {}
3431
3432    template <class _A0, class _A1>
3433        _LIBCPP_INLINE_VISIBILITY
3434        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
3435            :  __data_(__a, _Tp(__a0, __a1)) {}
3436
3437    template <class _A0, class _A1, class _A2>
3438        _LIBCPP_INLINE_VISIBILITY
3439        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
3440            :  __data_(__a, _Tp(__a0, __a1, __a2)) {}
3441
3442#endif  // _LIBCPP_HAS_NO_VARIADICS
3443
3444private:
3445    virtual void __on_zero_shared() _NOEXCEPT;
3446    virtual void __on_zero_shared_weak() _NOEXCEPT;
3447public:
3448    _LIBCPP_INLINE_VISIBILITY
3449    _Tp* get() _NOEXCEPT {return _VSTD::addressof(__data_.second());}
3450};
3451
3452template <class _Tp, class _Alloc>
3453void
3454__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
3455{
3456    __data_.second().~_Tp();
3457}
3458
3459template <class _Tp, class _Alloc>
3460void
3461__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3462{
3463    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
3464    typedef allocator_traits<_Al> _ATraits;
3465    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3466    _Al __a(__data_.first());
3467    __data_.first().~_Alloc();
3468    __a.deallocate(_PTraits::pointer_to(*this), 1);
3469}
3470
3471struct __shared_ptr_dummy_rebind_allocator_type;
3472template <>
3473class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type>
3474{
3475public:
3476    template <class _Other>
3477    struct rebind
3478    {
3479        typedef allocator<_Other> other;
3480    };
3481};
3482
3483template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
3484
3485template<class _Tp, class _Up>
3486struct __compatible_with
3487#if _LIBCPP_STD_VER > 14
3488    : is_convertible<remove_extent_t<_Tp>*, remove_extent_t<_Up>*> {};
3489#else
3490    : is_convertible<_Tp*, _Up*> {};
3491#endif // _LIBCPP_STD_VER > 14
3492
3493#if defined(_LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI)
3494#  define _LIBCPP_SHARED_PTR_TRIVIAL_ABI __attribute__((trivial_abi))
3495#else
3496#  define _LIBCPP_SHARED_PTR_TRIVIAL_ABI
3497#endif
3498
3499template<class _Tp>
3500class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS shared_ptr
3501{
3502public:
3503#if _LIBCPP_STD_VER > 14
3504    typedef weak_ptr<_Tp> weak_type;
3505    typedef remove_extent_t<_Tp> element_type;
3506#else
3507    typedef _Tp element_type;
3508#endif
3509
3510private:
3511    element_type*      __ptr_;
3512    __shared_weak_count* __cntrl_;
3513
3514    struct __nat {int __for_bool_;};
3515public:
3516    _LIBCPP_INLINE_VISIBILITY
3517    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
3518    _LIBCPP_INLINE_VISIBILITY
3519    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
3520    template<class _Yp>
3521        explicit shared_ptr(_Yp* __p,
3522                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat());
3523    template<class _Yp, class _Dp>
3524        shared_ptr(_Yp* __p, _Dp __d,
3525                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat());
3526    template<class _Yp, class _Dp, class _Alloc>
3527        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3528                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat());
3529    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
3530    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
3531    template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
3532    _LIBCPP_INLINE_VISIBILITY
3533    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
3534    template<class _Yp>
3535        _LIBCPP_INLINE_VISIBILITY
3536        shared_ptr(const shared_ptr<_Yp>& __r,
3537                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat())
3538                       _NOEXCEPT;
3539    _LIBCPP_INLINE_VISIBILITY
3540    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
3541    template<class _Yp> _LIBCPP_INLINE_VISIBILITY  shared_ptr(shared_ptr<_Yp>&& __r,
3542                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat())
3543                       _NOEXCEPT;
3544    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
3545                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type= __nat());
3546#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3547    template<class _Yp>
3548        shared_ptr(auto_ptr<_Yp>&& __r,
3549                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3550#endif
3551    template <class _Yp, class _Dp>
3552        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3553                   typename enable_if
3554                   <
3555                       !is_lvalue_reference<_Dp>::value &&
3556                       !is_array<_Yp>::value &&
3557                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3558                       __nat
3559                   >::type = __nat());
3560    template <class _Yp, class _Dp>
3561        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3562                   typename enable_if
3563                   <
3564                       is_lvalue_reference<_Dp>::value &&
3565                       !is_array<_Yp>::value &&
3566                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3567                       __nat
3568                   >::type = __nat());
3569
3570    ~shared_ptr();
3571
3572    _LIBCPP_INLINE_VISIBILITY
3573    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
3574    template<class _Yp>
3575        typename enable_if
3576        <
3577            __compatible_with<_Yp, element_type>::value,
3578            shared_ptr&
3579        >::type
3580        _LIBCPP_INLINE_VISIBILITY
3581        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
3582    _LIBCPP_INLINE_VISIBILITY
3583    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
3584    template<class _Yp>
3585        typename enable_if
3586        <
3587            __compatible_with<_Yp, element_type>::value,
3588            shared_ptr&
3589        >::type
3590        _LIBCPP_INLINE_VISIBILITY
3591        operator=(shared_ptr<_Yp>&& __r);
3592#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3593    template<class _Yp>
3594        _LIBCPP_INLINE_VISIBILITY
3595        typename enable_if
3596        <
3597            !is_array<_Yp>::value &&
3598            is_convertible<_Yp*, element_type*>::value,
3599            shared_ptr
3600        >::type&
3601        operator=(auto_ptr<_Yp>&& __r);
3602#endif
3603    template <class _Yp, class _Dp>
3604        typename enable_if
3605        <
3606            !is_array<_Yp>::value &&
3607            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3608            shared_ptr&
3609        >::type
3610        _LIBCPP_INLINE_VISIBILITY
3611        operator=(unique_ptr<_Yp, _Dp>&& __r);
3612
3613    _LIBCPP_INLINE_VISIBILITY
3614    void swap(shared_ptr& __r) _NOEXCEPT;
3615    _LIBCPP_INLINE_VISIBILITY
3616    void reset() _NOEXCEPT;
3617    template<class _Yp>
3618        typename enable_if
3619        <
3620            __compatible_with<_Yp, element_type>::value,
3621            void
3622        >::type
3623        _LIBCPP_INLINE_VISIBILITY
3624        reset(_Yp* __p);
3625    template<class _Yp, class _Dp>
3626        typename enable_if
3627        <
3628            __compatible_with<_Yp, element_type>::value,
3629            void
3630        >::type
3631        _LIBCPP_INLINE_VISIBILITY
3632        reset(_Yp* __p, _Dp __d);
3633    template<class _Yp, class _Dp, class _Alloc>
3634        typename enable_if
3635        <
3636            __compatible_with<_Yp, element_type>::value,
3637            void
3638        >::type
3639        _LIBCPP_INLINE_VISIBILITY
3640        reset(_Yp* __p, _Dp __d, _Alloc __a);
3641
3642    _LIBCPP_INLINE_VISIBILITY
3643    element_type* get() const _NOEXCEPT {return __ptr_;}
3644    _LIBCPP_INLINE_VISIBILITY
3645    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
3646        {return *__ptr_;}
3647    _LIBCPP_INLINE_VISIBILITY
3648    element_type* operator->() const _NOEXCEPT
3649    {
3650        static_assert(!_VSTD::is_array<_Tp>::value,
3651                      "std::shared_ptr<T>::operator-> is only valid when T is not an array type.");
3652        return __ptr_;
3653    }
3654    _LIBCPP_INLINE_VISIBILITY
3655    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
3656    _LIBCPP_INLINE_VISIBILITY
3657    bool unique() const _NOEXCEPT {return use_count() == 1;}
3658    _LIBCPP_INLINE_VISIBILITY
3659    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
3660    template <class _Up>
3661        _LIBCPP_INLINE_VISIBILITY
3662        bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT
3663        {return __cntrl_ < __p.__cntrl_;}
3664    template <class _Up>
3665        _LIBCPP_INLINE_VISIBILITY
3666        bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT
3667        {return __cntrl_ < __p.__cntrl_;}
3668    _LIBCPP_INLINE_VISIBILITY
3669    bool
3670    __owner_equivalent(const shared_ptr& __p) const
3671        {return __cntrl_ == __p.__cntrl_;}
3672
3673#if _LIBCPP_STD_VER > 14
3674    typename add_lvalue_reference<element_type>::type
3675    _LIBCPP_INLINE_VISIBILITY
3676    operator[](ptrdiff_t __i) const
3677    {
3678            static_assert(_VSTD::is_array<_Tp>::value,
3679                          "std::shared_ptr<T>::operator[] is only valid when T is an array type.");
3680            return __ptr_[__i];
3681    }
3682#endif
3683
3684#ifndef _LIBCPP_NO_RTTI
3685    template <class _Dp>
3686        _LIBCPP_INLINE_VISIBILITY
3687        _Dp* __get_deleter() const _NOEXCEPT
3688            {return static_cast<_Dp*>(__cntrl_
3689                    ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp)))
3690                      : nullptr);}
3691#endif  // _LIBCPP_NO_RTTI
3692
3693    template<class _Yp, class _CntrlBlk>
3694    static shared_ptr<_Tp>
3695    __create_with_control_block(_Yp* __p, _CntrlBlk* __cntrl) _NOEXCEPT
3696    {
3697        shared_ptr<_Tp> __r;
3698        __r.__ptr_ = __p;
3699        __r.__cntrl_ = __cntrl;
3700        __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
3701        return __r;
3702    }
3703
3704private:
3705    template <class _Yp, bool = is_function<_Yp>::value>
3706        struct __shared_ptr_default_allocator
3707        {
3708            typedef allocator<_Yp> type;
3709        };
3710
3711    template <class _Yp>
3712        struct __shared_ptr_default_allocator<_Yp, true>
3713        {
3714            typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
3715        };
3716
3717    template <class _Yp, class _OrigPtr>
3718        _LIBCPP_INLINE_VISIBILITY
3719        typename enable_if<is_convertible<_OrigPtr*,
3720                                          const enable_shared_from_this<_Yp>*
3721        >::value,
3722            void>::type
3723        __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
3724                           _OrigPtr* __ptr) _NOEXCEPT
3725        {
3726            typedef typename remove_cv<_Yp>::type _RawYp;
3727            if (__e && __e->__weak_this_.expired())
3728            {
3729                __e->__weak_this_ = shared_ptr<_RawYp>(*this,
3730                    const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
3731            }
3732        }
3733
3734    _LIBCPP_INLINE_VISIBILITY void __enable_weak_this(...) _NOEXCEPT {}
3735
3736    template <class, class _Yp>
3737        struct __shared_ptr_default_delete
3738            : default_delete<_Yp> {};
3739
3740    template <class _Yp, class _Un, size_t _Sz>
3741        struct __shared_ptr_default_delete<_Yp[_Sz], _Un>
3742            : default_delete<_Yp[]> {};
3743
3744    template <class _Yp, class _Un>
3745        struct __shared_ptr_default_delete<_Yp[], _Un>
3746            : default_delete<_Yp[]> {};
3747
3748    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
3749    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
3750};
3751
3752#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
3753template<class _Tp>
3754shared_ptr(weak_ptr<_Tp>) -> shared_ptr<_Tp>;
3755template<class _Tp, class _Dp>
3756shared_ptr(unique_ptr<_Tp, _Dp>) -> shared_ptr<_Tp>;
3757#endif
3758
3759template<class _Tp>
3760inline
3761_LIBCPP_CONSTEXPR
3762shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
3763    : __ptr_(0),
3764      __cntrl_(0)
3765{
3766}
3767
3768template<class _Tp>
3769inline
3770_LIBCPP_CONSTEXPR
3771shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
3772    : __ptr_(0),
3773      __cntrl_(0)
3774{
3775}
3776
3777template<class _Tp>
3778template<class _Yp>
3779shared_ptr<_Tp>::shared_ptr(_Yp* __p,
3780                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3781    : __ptr_(__p)
3782{
3783    unique_ptr<_Yp> __hold(__p);
3784    typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3785    typedef __shared_ptr_pointer<_Yp*, __shared_ptr_default_delete<_Tp, _Yp>, _AllocT > _CntrlBlk;
3786    __cntrl_ = new _CntrlBlk(__p, __shared_ptr_default_delete<_Tp, _Yp>(), _AllocT());
3787    __hold.release();
3788    __enable_weak_this(__p, __p);
3789}
3790
3791template<class _Tp>
3792template<class _Yp, class _Dp>
3793shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
3794                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3795    : __ptr_(__p)
3796{
3797#ifndef _LIBCPP_NO_EXCEPTIONS
3798    try
3799    {
3800#endif  // _LIBCPP_NO_EXCEPTIONS
3801        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3802        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
3803        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
3804        __enable_weak_this(__p, __p);
3805#ifndef _LIBCPP_NO_EXCEPTIONS
3806    }
3807    catch (...)
3808    {
3809        __d(__p);
3810        throw;
3811    }
3812#endif  // _LIBCPP_NO_EXCEPTIONS
3813}
3814
3815template<class _Tp>
3816template<class _Dp>
3817shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
3818    : __ptr_(0)
3819{
3820#ifndef _LIBCPP_NO_EXCEPTIONS
3821    try
3822    {
3823#endif  // _LIBCPP_NO_EXCEPTIONS
3824        typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
3825        typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
3826        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
3827#ifndef _LIBCPP_NO_EXCEPTIONS
3828    }
3829    catch (...)
3830    {
3831        __d(__p);
3832        throw;
3833    }
3834#endif  // _LIBCPP_NO_EXCEPTIONS
3835}
3836
3837template<class _Tp>
3838template<class _Yp, class _Dp, class _Alloc>
3839shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3840                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3841    : __ptr_(__p)
3842{
3843#ifndef _LIBCPP_NO_EXCEPTIONS
3844    try
3845    {
3846#endif  // _LIBCPP_NO_EXCEPTIONS
3847        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
3848        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
3849        typedef __allocator_destructor<_A2> _D2;
3850        _A2 __a2(__a);
3851        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
3852        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
3853            _CntrlBlk(__p, __d, __a);
3854        __cntrl_ = _VSTD::addressof(*__hold2.release());
3855        __enable_weak_this(__p, __p);
3856#ifndef _LIBCPP_NO_EXCEPTIONS
3857    }
3858    catch (...)
3859    {
3860        __d(__p);
3861        throw;
3862    }
3863#endif  // _LIBCPP_NO_EXCEPTIONS
3864}
3865
3866template<class _Tp>
3867template<class _Dp, class _Alloc>
3868shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
3869    : __ptr_(0)
3870{
3871#ifndef _LIBCPP_NO_EXCEPTIONS
3872    try
3873    {
3874#endif  // _LIBCPP_NO_EXCEPTIONS
3875        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
3876        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
3877        typedef __allocator_destructor<_A2> _D2;
3878        _A2 __a2(__a);
3879        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
3880        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
3881            _CntrlBlk(__p, __d, __a);
3882        __cntrl_ = _VSTD::addressof(*__hold2.release());
3883#ifndef _LIBCPP_NO_EXCEPTIONS
3884    }
3885    catch (...)
3886    {
3887        __d(__p);
3888        throw;
3889    }
3890#endif  // _LIBCPP_NO_EXCEPTIONS
3891}
3892
3893template<class _Tp>
3894template<class _Yp>
3895inline
3896shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
3897    : __ptr_(__p),
3898      __cntrl_(__r.__cntrl_)
3899{
3900    if (__cntrl_)
3901        __cntrl_->__add_shared();
3902}
3903
3904template<class _Tp>
3905inline
3906shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
3907    : __ptr_(__r.__ptr_),
3908      __cntrl_(__r.__cntrl_)
3909{
3910    if (__cntrl_)
3911        __cntrl_->__add_shared();
3912}
3913
3914template<class _Tp>
3915template<class _Yp>
3916inline
3917shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
3918                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3919         _NOEXCEPT
3920    : __ptr_(__r.__ptr_),
3921      __cntrl_(__r.__cntrl_)
3922{
3923    if (__cntrl_)
3924        __cntrl_->__add_shared();
3925}
3926
3927template<class _Tp>
3928inline
3929shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
3930    : __ptr_(__r.__ptr_),
3931      __cntrl_(__r.__cntrl_)
3932{
3933    __r.__ptr_ = 0;
3934    __r.__cntrl_ = 0;
3935}
3936
3937template<class _Tp>
3938template<class _Yp>
3939inline
3940shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
3941                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3942         _NOEXCEPT
3943    : __ptr_(__r.__ptr_),
3944      __cntrl_(__r.__cntrl_)
3945{
3946    __r.__ptr_ = 0;
3947    __r.__cntrl_ = 0;
3948}
3949
3950#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3951template<class _Tp>
3952template<class _Yp>
3953shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
3954                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
3955    : __ptr_(__r.get())
3956{
3957    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
3958    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
3959    __enable_weak_this(__r.get(), __r.get());
3960    __r.release();
3961}
3962#endif
3963
3964template<class _Tp>
3965template <class _Yp, class _Dp>
3966shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
3967                            typename enable_if
3968                            <
3969                                !is_lvalue_reference<_Dp>::value &&
3970                                !is_array<_Yp>::value &&
3971                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3972                                __nat
3973                            >::type)
3974    : __ptr_(__r.get())
3975{
3976#if _LIBCPP_STD_VER > 11
3977    if (__ptr_ == nullptr)
3978        __cntrl_ = nullptr;
3979    else
3980#endif
3981    {
3982        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3983        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
3984        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), _AllocT());
3985        __enable_weak_this(__r.get(), __r.get());
3986    }
3987    __r.release();
3988}
3989
3990template<class _Tp>
3991template <class _Yp, class _Dp>
3992shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
3993                            typename enable_if
3994                            <
3995                                is_lvalue_reference<_Dp>::value &&
3996                                !is_array<_Yp>::value &&
3997                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3998                                __nat
3999                            >::type)
4000    : __ptr_(__r.get())
4001{
4002#if _LIBCPP_STD_VER > 11
4003    if (__ptr_ == nullptr)
4004        __cntrl_ = nullptr;
4005    else
4006#endif
4007    {
4008        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4009        typedef __shared_ptr_pointer<_Yp*,
4010                                     reference_wrapper<typename remove_reference<_Dp>::type>,
4011                                     _AllocT > _CntrlBlk;
4012        __cntrl_ = new _CntrlBlk(__r.get(), _VSTD::ref(__r.get_deleter()), _AllocT());
4013        __enable_weak_this(__r.get(), __r.get());
4014    }
4015    __r.release();
4016}
4017
4018template<class _Tp>
4019shared_ptr<_Tp>::~shared_ptr()
4020{
4021    if (__cntrl_)
4022        __cntrl_->__release_shared();
4023}
4024
4025template<class _Tp>
4026inline
4027shared_ptr<_Tp>&
4028shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
4029{
4030    shared_ptr(__r).swap(*this);
4031    return *this;
4032}
4033
4034template<class _Tp>
4035template<class _Yp>
4036inline
4037typename enable_if
4038<
4039    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4040    shared_ptr<_Tp>&
4041>::type
4042shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
4043{
4044    shared_ptr(__r).swap(*this);
4045    return *this;
4046}
4047
4048template<class _Tp>
4049inline
4050shared_ptr<_Tp>&
4051shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
4052{
4053    shared_ptr(_VSTD::move(__r)).swap(*this);
4054    return *this;
4055}
4056
4057template<class _Tp>
4058template<class _Yp>
4059inline
4060typename enable_if
4061<
4062    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4063    shared_ptr<_Tp>&
4064>::type
4065shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
4066{
4067    shared_ptr(_VSTD::move(__r)).swap(*this);
4068    return *this;
4069}
4070
4071#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4072template<class _Tp>
4073template<class _Yp>
4074inline
4075typename enable_if
4076<
4077    !is_array<_Yp>::value &&
4078    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4079    shared_ptr<_Tp>
4080>::type&
4081shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
4082{
4083    shared_ptr(_VSTD::move(__r)).swap(*this);
4084    return *this;
4085}
4086#endif
4087
4088template<class _Tp>
4089template <class _Yp, class _Dp>
4090inline
4091typename enable_if
4092<
4093    !is_array<_Yp>::value &&
4094    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4095                   typename shared_ptr<_Tp>::element_type*>::value,
4096    shared_ptr<_Tp>&
4097>::type
4098shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
4099{
4100    shared_ptr(_VSTD::move(__r)).swap(*this);
4101    return *this;
4102}
4103
4104template<class _Tp>
4105inline
4106void
4107shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
4108{
4109    _VSTD::swap(__ptr_, __r.__ptr_);
4110    _VSTD::swap(__cntrl_, __r.__cntrl_);
4111}
4112
4113template<class _Tp>
4114inline
4115void
4116shared_ptr<_Tp>::reset() _NOEXCEPT
4117{
4118    shared_ptr().swap(*this);
4119}
4120
4121template<class _Tp>
4122template<class _Yp>
4123inline
4124typename enable_if
4125<
4126    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4127    void
4128>::type
4129shared_ptr<_Tp>::reset(_Yp* __p)
4130{
4131    shared_ptr(__p).swap(*this);
4132}
4133
4134template<class _Tp>
4135template<class _Yp, class _Dp>
4136inline
4137typename enable_if
4138<
4139    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4140    void
4141>::type
4142shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
4143{
4144    shared_ptr(__p, __d).swap(*this);
4145}
4146
4147template<class _Tp>
4148template<class _Yp, class _Dp, class _Alloc>
4149inline
4150typename enable_if
4151<
4152    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4153    void
4154>::type
4155shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
4156{
4157    shared_ptr(__p, __d, __a).swap(*this);
4158}
4159
4160template<class _Tp, class ..._Args>
4161inline _LIBCPP_INLINE_VISIBILITY
4162typename enable_if
4163<
4164    !is_array<_Tp>::value,
4165    shared_ptr<_Tp>
4166>::type
4167make_shared(_Args&& ...__args)
4168{
4169    static_assert(is_constructible<_Tp, _Args...>::value, "Can't construct object in make_shared");
4170    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4171    typedef allocator<_CntrlBlk> _A2;
4172    typedef __allocator_destructor<_A2> _D2;
4173
4174    _A2 __a2;
4175    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4176    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
4177
4178    _Tp *__ptr = __hold2.get()->get();
4179    return shared_ptr<_Tp>::__create_with_control_block(__ptr, __hold2.release());
4180}
4181
4182template<class _Tp, class _Alloc, class ..._Args>
4183inline _LIBCPP_INLINE_VISIBILITY
4184typename enable_if
4185<
4186    !is_array<_Tp>::value,
4187    shared_ptr<_Tp>
4188>::type
4189allocate_shared(const _Alloc& __a, _Args&& ...__args)
4190{
4191    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in allocate_shared");
4192
4193    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4194    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4195    typedef __allocator_destructor<_A2> _D2;
4196
4197    _A2 __a2(__a);
4198    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4199    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4200        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
4201
4202    typename shared_ptr<_Tp>::element_type *__p = __hold2.get()->get();
4203    return shared_ptr<_Tp>::__create_with_control_block(__p, _VSTD::addressof(*__hold2.release()));
4204}
4205
4206template<class _Tp, class _Up>
4207inline _LIBCPP_INLINE_VISIBILITY
4208bool
4209operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4210{
4211    return __x.get() == __y.get();
4212}
4213
4214template<class _Tp, class _Up>
4215inline _LIBCPP_INLINE_VISIBILITY
4216bool
4217operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4218{
4219    return !(__x == __y);
4220}
4221
4222template<class _Tp, class _Up>
4223inline _LIBCPP_INLINE_VISIBILITY
4224bool
4225operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4226{
4227#if _LIBCPP_STD_VER <= 11
4228    typedef typename common_type<_Tp*, _Up*>::type _Vp;
4229    return less<_Vp>()(__x.get(), __y.get());
4230#else
4231    return less<>()(__x.get(), __y.get());
4232#endif
4233
4234}
4235
4236template<class _Tp, class _Up>
4237inline _LIBCPP_INLINE_VISIBILITY
4238bool
4239operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4240{
4241    return __y < __x;
4242}
4243
4244template<class _Tp, class _Up>
4245inline _LIBCPP_INLINE_VISIBILITY
4246bool
4247operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4248{
4249    return !(__y < __x);
4250}
4251
4252template<class _Tp, class _Up>
4253inline _LIBCPP_INLINE_VISIBILITY
4254bool
4255operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4256{
4257    return !(__x < __y);
4258}
4259
4260template<class _Tp>
4261inline _LIBCPP_INLINE_VISIBILITY
4262bool
4263operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4264{
4265    return !__x;
4266}
4267
4268template<class _Tp>
4269inline _LIBCPP_INLINE_VISIBILITY
4270bool
4271operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4272{
4273    return !__x;
4274}
4275
4276template<class _Tp>
4277inline _LIBCPP_INLINE_VISIBILITY
4278bool
4279operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4280{
4281    return static_cast<bool>(__x);
4282}
4283
4284template<class _Tp>
4285inline _LIBCPP_INLINE_VISIBILITY
4286bool
4287operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4288{
4289    return static_cast<bool>(__x);
4290}
4291
4292template<class _Tp>
4293inline _LIBCPP_INLINE_VISIBILITY
4294bool
4295operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4296{
4297    return less<_Tp*>()(__x.get(), nullptr);
4298}
4299
4300template<class _Tp>
4301inline _LIBCPP_INLINE_VISIBILITY
4302bool
4303operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4304{
4305    return less<_Tp*>()(nullptr, __x.get());
4306}
4307
4308template<class _Tp>
4309inline _LIBCPP_INLINE_VISIBILITY
4310bool
4311operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4312{
4313    return nullptr < __x;
4314}
4315
4316template<class _Tp>
4317inline _LIBCPP_INLINE_VISIBILITY
4318bool
4319operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4320{
4321    return __x < nullptr;
4322}
4323
4324template<class _Tp>
4325inline _LIBCPP_INLINE_VISIBILITY
4326bool
4327operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4328{
4329    return !(nullptr < __x);
4330}
4331
4332template<class _Tp>
4333inline _LIBCPP_INLINE_VISIBILITY
4334bool
4335operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4336{
4337    return !(__x < nullptr);
4338}
4339
4340template<class _Tp>
4341inline _LIBCPP_INLINE_VISIBILITY
4342bool
4343operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4344{
4345    return !(__x < nullptr);
4346}
4347
4348template<class _Tp>
4349inline _LIBCPP_INLINE_VISIBILITY
4350bool
4351operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4352{
4353    return !(nullptr < __x);
4354}
4355
4356template<class _Tp>
4357inline _LIBCPP_INLINE_VISIBILITY
4358void
4359swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
4360{
4361    __x.swap(__y);
4362}
4363
4364template<class _Tp, class _Up>
4365inline _LIBCPP_INLINE_VISIBILITY
4366shared_ptr<_Tp>
4367static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4368{
4369    return shared_ptr<_Tp>(__r,
4370                           static_cast<
4371                               typename shared_ptr<_Tp>::element_type*>(__r.get()));
4372}
4373
4374template<class _Tp, class _Up>
4375inline _LIBCPP_INLINE_VISIBILITY
4376shared_ptr<_Tp>
4377dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4378{
4379    typedef typename shared_ptr<_Tp>::element_type _ET;
4380    _ET* __p = dynamic_cast<_ET*>(__r.get());
4381    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
4382}
4383
4384template<class _Tp, class _Up>
4385shared_ptr<_Tp>
4386const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4387{
4388    typedef typename shared_ptr<_Tp>::element_type _RTp;
4389    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
4390}
4391
4392template<class _Tp, class _Up>
4393shared_ptr<_Tp>
4394reinterpret_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4395{
4396    return shared_ptr<_Tp>(__r,
4397                           reinterpret_cast<
4398                               typename shared_ptr<_Tp>::element_type*>(__r.get()));
4399}
4400
4401#ifndef _LIBCPP_NO_RTTI
4402
4403template<class _Dp, class _Tp>
4404inline _LIBCPP_INLINE_VISIBILITY
4405_Dp*
4406get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
4407{
4408    return __p.template __get_deleter<_Dp>();
4409}
4410
4411#endif  // _LIBCPP_NO_RTTI
4412
4413template<class _Tp>
4414class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS weak_ptr
4415{
4416public:
4417    typedef _Tp element_type;
4418private:
4419    element_type*        __ptr_;
4420    __shared_weak_count* __cntrl_;
4421
4422public:
4423    _LIBCPP_INLINE_VISIBILITY
4424    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
4425    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r,
4426                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4427                        _NOEXCEPT;
4428    _LIBCPP_INLINE_VISIBILITY
4429    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
4430    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r,
4431                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4432                         _NOEXCEPT;
4433
4434    _LIBCPP_INLINE_VISIBILITY
4435    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
4436    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r,
4437                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4438                         _NOEXCEPT;
4439    ~weak_ptr();
4440
4441    _LIBCPP_INLINE_VISIBILITY
4442    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
4443    template<class _Yp>
4444        typename enable_if
4445        <
4446            is_convertible<_Yp*, element_type*>::value,
4447            weak_ptr&
4448        >::type
4449        _LIBCPP_INLINE_VISIBILITY
4450        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
4451
4452    _LIBCPP_INLINE_VISIBILITY
4453    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
4454    template<class _Yp>
4455        typename enable_if
4456        <
4457            is_convertible<_Yp*, element_type*>::value,
4458            weak_ptr&
4459        >::type
4460        _LIBCPP_INLINE_VISIBILITY
4461        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
4462
4463    template<class _Yp>
4464        typename enable_if
4465        <
4466            is_convertible<_Yp*, element_type*>::value,
4467            weak_ptr&
4468        >::type
4469        _LIBCPP_INLINE_VISIBILITY
4470        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
4471
4472    _LIBCPP_INLINE_VISIBILITY
4473    void swap(weak_ptr& __r) _NOEXCEPT;
4474    _LIBCPP_INLINE_VISIBILITY
4475    void reset() _NOEXCEPT;
4476
4477    _LIBCPP_INLINE_VISIBILITY
4478    long use_count() const _NOEXCEPT
4479        {return __cntrl_ ? __cntrl_->use_count() : 0;}
4480    _LIBCPP_INLINE_VISIBILITY
4481    bool expired() const _NOEXCEPT
4482        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
4483    shared_ptr<_Tp> lock() const _NOEXCEPT;
4484    template<class _Up>
4485        _LIBCPP_INLINE_VISIBILITY
4486        bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT
4487        {return __cntrl_ < __r.__cntrl_;}
4488    template<class _Up>
4489        _LIBCPP_INLINE_VISIBILITY
4490        bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT
4491        {return __cntrl_ < __r.__cntrl_;}
4492
4493    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
4494    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
4495};
4496
4497#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
4498template<class _Tp>
4499weak_ptr(shared_ptr<_Tp>) -> weak_ptr<_Tp>;
4500#endif
4501
4502template<class _Tp>
4503inline
4504_LIBCPP_CONSTEXPR
4505weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
4506    : __ptr_(0),
4507      __cntrl_(0)
4508{
4509}
4510
4511template<class _Tp>
4512inline
4513weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
4514    : __ptr_(__r.__ptr_),
4515      __cntrl_(__r.__cntrl_)
4516{
4517    if (__cntrl_)
4518        __cntrl_->__add_weak();
4519}
4520
4521template<class _Tp>
4522template<class _Yp>
4523inline
4524weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
4525                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4526                         _NOEXCEPT
4527    : __ptr_(__r.__ptr_),
4528      __cntrl_(__r.__cntrl_)
4529{
4530    if (__cntrl_)
4531        __cntrl_->__add_weak();
4532}
4533
4534template<class _Tp>
4535template<class _Yp>
4536inline
4537weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
4538                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4539         _NOEXCEPT
4540    : __ptr_(__r.__ptr_),
4541      __cntrl_(__r.__cntrl_)
4542{
4543    if (__cntrl_)
4544        __cntrl_->__add_weak();
4545}
4546
4547template<class _Tp>
4548inline
4549weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
4550    : __ptr_(__r.__ptr_),
4551      __cntrl_(__r.__cntrl_)
4552{
4553    __r.__ptr_ = 0;
4554    __r.__cntrl_ = 0;
4555}
4556
4557template<class _Tp>
4558template<class _Yp>
4559inline
4560weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
4561                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4562         _NOEXCEPT
4563    : __ptr_(__r.__ptr_),
4564      __cntrl_(__r.__cntrl_)
4565{
4566    __r.__ptr_ = 0;
4567    __r.__cntrl_ = 0;
4568}
4569
4570template<class _Tp>
4571weak_ptr<_Tp>::~weak_ptr()
4572{
4573    if (__cntrl_)
4574        __cntrl_->__release_weak();
4575}
4576
4577template<class _Tp>
4578inline
4579weak_ptr<_Tp>&
4580weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
4581{
4582    weak_ptr(__r).swap(*this);
4583    return *this;
4584}
4585
4586template<class _Tp>
4587template<class _Yp>
4588inline
4589typename enable_if
4590<
4591    is_convertible<_Yp*, _Tp*>::value,
4592    weak_ptr<_Tp>&
4593>::type
4594weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
4595{
4596    weak_ptr(__r).swap(*this);
4597    return *this;
4598}
4599
4600template<class _Tp>
4601inline
4602weak_ptr<_Tp>&
4603weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
4604{
4605    weak_ptr(_VSTD::move(__r)).swap(*this);
4606    return *this;
4607}
4608
4609template<class _Tp>
4610template<class _Yp>
4611inline
4612typename enable_if
4613<
4614    is_convertible<_Yp*, _Tp*>::value,
4615    weak_ptr<_Tp>&
4616>::type
4617weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
4618{
4619    weak_ptr(_VSTD::move(__r)).swap(*this);
4620    return *this;
4621}
4622
4623template<class _Tp>
4624template<class _Yp>
4625inline
4626typename enable_if
4627<
4628    is_convertible<_Yp*, _Tp*>::value,
4629    weak_ptr<_Tp>&
4630>::type
4631weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
4632{
4633    weak_ptr(__r).swap(*this);
4634    return *this;
4635}
4636
4637template<class _Tp>
4638inline
4639void
4640weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
4641{
4642    _VSTD::swap(__ptr_, __r.__ptr_);
4643    _VSTD::swap(__cntrl_, __r.__cntrl_);
4644}
4645
4646template<class _Tp>
4647inline _LIBCPP_INLINE_VISIBILITY
4648void
4649swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
4650{
4651    __x.swap(__y);
4652}
4653
4654template<class _Tp>
4655inline
4656void
4657weak_ptr<_Tp>::reset() _NOEXCEPT
4658{
4659    weak_ptr().swap(*this);
4660}
4661
4662template<class _Tp>
4663template<class _Yp>
4664shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
4665                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4666    : __ptr_(__r.__ptr_),
4667      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
4668{
4669    if (__cntrl_ == 0)
4670        __throw_bad_weak_ptr();
4671}
4672
4673template<class _Tp>
4674shared_ptr<_Tp>
4675weak_ptr<_Tp>::lock() const _NOEXCEPT
4676{
4677    shared_ptr<_Tp> __r;
4678    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
4679    if (__r.__cntrl_)
4680        __r.__ptr_ = __ptr_;
4681    return __r;
4682}
4683
4684#if _LIBCPP_STD_VER > 14
4685template <class _Tp = void> struct owner_less;
4686#else
4687template <class _Tp> struct owner_less;
4688#endif
4689
4690template <class _Tp>
4691struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> >
4692    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
4693{
4694    typedef bool result_type;
4695    _LIBCPP_INLINE_VISIBILITY
4696    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4697        {return __x.owner_before(__y);}
4698    _LIBCPP_INLINE_VISIBILITY
4699    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4700        {return __x.owner_before(__y);}
4701    _LIBCPP_INLINE_VISIBILITY
4702    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4703        {return __x.owner_before(__y);}
4704};
4705
4706template <class _Tp>
4707struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> >
4708    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
4709{
4710    typedef bool result_type;
4711    _LIBCPP_INLINE_VISIBILITY
4712    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4713        {return __x.owner_before(__y);}
4714    _LIBCPP_INLINE_VISIBILITY
4715    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4716        {return __x.owner_before(__y);}
4717    _LIBCPP_INLINE_VISIBILITY
4718    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4719        {return __x.owner_before(__y);}
4720};
4721
4722#if _LIBCPP_STD_VER > 14
4723template <>
4724struct _LIBCPP_TEMPLATE_VIS owner_less<void>
4725{
4726    template <class _Tp, class _Up>
4727    _LIBCPP_INLINE_VISIBILITY
4728    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
4729        {return __x.owner_before(__y);}
4730    template <class _Tp, class _Up>
4731    _LIBCPP_INLINE_VISIBILITY
4732    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
4733        {return __x.owner_before(__y);}
4734    template <class _Tp, class _Up>
4735    _LIBCPP_INLINE_VISIBILITY
4736    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
4737        {return __x.owner_before(__y);}
4738    template <class _Tp, class _Up>
4739    _LIBCPP_INLINE_VISIBILITY
4740    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
4741        {return __x.owner_before(__y);}
4742    typedef void is_transparent;
4743};
4744#endif
4745
4746template<class _Tp>
4747class _LIBCPP_TEMPLATE_VIS enable_shared_from_this
4748{
4749    mutable weak_ptr<_Tp> __weak_this_;
4750protected:
4751    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
4752    enable_shared_from_this() _NOEXCEPT {}
4753    _LIBCPP_INLINE_VISIBILITY
4754    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
4755    _LIBCPP_INLINE_VISIBILITY
4756    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
4757        {return *this;}
4758    _LIBCPP_INLINE_VISIBILITY
4759    ~enable_shared_from_this() {}
4760public:
4761    _LIBCPP_INLINE_VISIBILITY
4762    shared_ptr<_Tp> shared_from_this()
4763        {return shared_ptr<_Tp>(__weak_this_);}
4764    _LIBCPP_INLINE_VISIBILITY
4765    shared_ptr<_Tp const> shared_from_this() const
4766        {return shared_ptr<const _Tp>(__weak_this_);}
4767
4768#if _LIBCPP_STD_VER > 14
4769    _LIBCPP_INLINE_VISIBILITY
4770    weak_ptr<_Tp> weak_from_this() _NOEXCEPT
4771       { return __weak_this_; }
4772
4773    _LIBCPP_INLINE_VISIBILITY
4774    weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT
4775        { return __weak_this_; }
4776#endif // _LIBCPP_STD_VER > 14
4777
4778    template <class _Up> friend class shared_ptr;
4779};
4780
4781template <class _Tp>
4782struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> >
4783{
4784    typedef shared_ptr<_Tp>      argument_type;
4785    typedef size_t               result_type;
4786
4787    _LIBCPP_INLINE_VISIBILITY
4788    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
4789    {
4790        return hash<typename shared_ptr<_Tp>::element_type*>()(__ptr.get());
4791    }
4792};
4793
4794template<class _CharT, class _Traits, class _Yp>
4795inline _LIBCPP_INLINE_VISIBILITY
4796basic_ostream<_CharT, _Traits>&
4797operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
4798
4799
4800#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
4801
4802class _LIBCPP_TYPE_VIS __sp_mut
4803{
4804    void* __lx;
4805public:
4806    void lock() _NOEXCEPT;
4807    void unlock() _NOEXCEPT;
4808
4809private:
4810    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
4811    __sp_mut(const __sp_mut&);
4812    __sp_mut& operator=(const __sp_mut&);
4813
4814    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
4815};
4816
4817_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4818__sp_mut& __get_sp_mut(const void*);
4819
4820template <class _Tp>
4821inline _LIBCPP_INLINE_VISIBILITY
4822bool
4823atomic_is_lock_free(const shared_ptr<_Tp>*)
4824{
4825    return false;
4826}
4827
4828template <class _Tp>
4829_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4830shared_ptr<_Tp>
4831atomic_load(const shared_ptr<_Tp>* __p)
4832{
4833    __sp_mut& __m = __get_sp_mut(__p);
4834    __m.lock();
4835    shared_ptr<_Tp> __q = *__p;
4836    __m.unlock();
4837    return __q;
4838}
4839
4840template <class _Tp>
4841inline _LIBCPP_INLINE_VISIBILITY
4842_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4843shared_ptr<_Tp>
4844atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
4845{
4846    return atomic_load(__p);
4847}
4848
4849template <class _Tp>
4850_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4851void
4852atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
4853{
4854    __sp_mut& __m = __get_sp_mut(__p);
4855    __m.lock();
4856    __p->swap(__r);
4857    __m.unlock();
4858}
4859
4860template <class _Tp>
4861inline _LIBCPP_INLINE_VISIBILITY
4862_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4863void
4864atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
4865{
4866    atomic_store(__p, __r);
4867}
4868
4869template <class _Tp>
4870_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4871shared_ptr<_Tp>
4872atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
4873{
4874    __sp_mut& __m = __get_sp_mut(__p);
4875    __m.lock();
4876    __p->swap(__r);
4877    __m.unlock();
4878    return __r;
4879}
4880
4881template <class _Tp>
4882inline _LIBCPP_INLINE_VISIBILITY
4883_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4884shared_ptr<_Tp>
4885atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
4886{
4887    return atomic_exchange(__p, __r);
4888}
4889
4890template <class _Tp>
4891_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4892bool
4893atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
4894{
4895    shared_ptr<_Tp> __temp;
4896    __sp_mut& __m = __get_sp_mut(__p);
4897    __m.lock();
4898    if (__p->__owner_equivalent(*__v))
4899    {
4900        _VSTD::swap(__temp, *__p);
4901        *__p = __w;
4902        __m.unlock();
4903        return true;
4904    }
4905    _VSTD::swap(__temp, *__v);
4906    *__v = *__p;
4907    __m.unlock();
4908    return false;
4909}
4910
4911template <class _Tp>
4912inline _LIBCPP_INLINE_VISIBILITY
4913_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4914bool
4915atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
4916{
4917    return atomic_compare_exchange_strong(__p, __v, __w);
4918}
4919
4920template <class _Tp>
4921inline _LIBCPP_INLINE_VISIBILITY
4922_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4923bool
4924atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
4925                                        shared_ptr<_Tp> __w, memory_order, memory_order)
4926{
4927    return atomic_compare_exchange_strong(__p, __v, __w);
4928}
4929
4930template <class _Tp>
4931inline _LIBCPP_INLINE_VISIBILITY
4932_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4933bool
4934atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
4935                                      shared_ptr<_Tp> __w, memory_order, memory_order)
4936{
4937    return atomic_compare_exchange_weak(__p, __v, __w);
4938}
4939
4940#endif  // !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
4941
4942//enum class
4943#if defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE)
4944# ifndef _LIBCPP_CXX03_LANG
4945enum class pointer_safety : unsigned char {
4946  relaxed,
4947  preferred,
4948  strict
4949};
4950# endif
4951#else
4952struct _LIBCPP_TYPE_VIS pointer_safety
4953{
4954    enum __lx
4955    {
4956        relaxed,
4957        preferred,
4958        strict
4959    };
4960
4961    __lx __v_;
4962
4963    _LIBCPP_INLINE_VISIBILITY
4964    pointer_safety() : __v_() {}
4965
4966    _LIBCPP_INLINE_VISIBILITY
4967    pointer_safety(__lx __v) : __v_(__v) {}
4968    _LIBCPP_INLINE_VISIBILITY
4969    operator int() const {return __v_;}
4970};
4971#endif
4972
4973#if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) && \
4974    defined(_LIBCPP_BUILDING_LIBRARY)
4975_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
4976#else
4977// This function is only offered in C++03 under ABI v1.
4978# if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) || !defined(_LIBCPP_CXX03_LANG)
4979inline _LIBCPP_INLINE_VISIBILITY
4980pointer_safety get_pointer_safety() _NOEXCEPT {
4981  return pointer_safety::relaxed;
4982}
4983# endif
4984#endif
4985
4986
4987_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
4988_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
4989_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
4990_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
4991
4992template <class _Tp>
4993inline _LIBCPP_INLINE_VISIBILITY
4994_Tp*
4995undeclare_reachable(_Tp* __p)
4996{
4997    return static_cast<_Tp*>(__undeclare_reachable(__p));
4998}
4999
5000_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
5001
5002// --- Helper for container swap --
5003template <typename _Alloc>
5004inline _LIBCPP_INLINE_VISIBILITY
5005void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
5006#if _LIBCPP_STD_VER >= 14
5007    _NOEXCEPT
5008#else
5009    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5010#endif
5011{
5012    __swap_allocator(__a1, __a2,
5013      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
5014}
5015
5016template <typename _Alloc>
5017_LIBCPP_INLINE_VISIBILITY
5018void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
5019#if _LIBCPP_STD_VER >= 14
5020    _NOEXCEPT
5021#else
5022    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5023#endif
5024{
5025    using _VSTD::swap;
5026    swap(__a1, __a2);
5027}
5028
5029template <typename _Alloc>
5030inline _LIBCPP_INLINE_VISIBILITY
5031void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
5032
5033template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
5034struct __noexcept_move_assign_container : public integral_constant<bool,
5035    _Traits::propagate_on_container_move_assignment::value
5036#if _LIBCPP_STD_VER > 14
5037        || _Traits::is_always_equal::value
5038#else
5039        && is_nothrow_move_assignable<_Alloc>::value
5040#endif
5041    > {};
5042
5043
5044#ifndef _LIBCPP_HAS_NO_VARIADICS
5045template <class _Tp, class _Alloc>
5046struct __temp_value {
5047    typedef allocator_traits<_Alloc> _Traits;
5048
5049    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
5050    _Alloc &__a;
5051
5052    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
5053    _Tp &   get() { return *__addr(); }
5054
5055    template<class... _Args>
5056    _LIBCPP_NO_CFI
5057    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
5058      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
5059                         _VSTD::forward<_Args>(__args)...);
5060    }
5061
5062    ~__temp_value() { _Traits::destroy(__a, __addr()); }
5063    };
5064#endif
5065
5066template<typename _Alloc, typename = void, typename = void>
5067struct __is_allocator : false_type {};
5068
5069template<typename _Alloc>
5070struct __is_allocator<_Alloc,
5071       typename __void_t<typename _Alloc::value_type>::type,
5072       typename __void_t<decltype(_VSTD::declval<_Alloc&>().allocate(size_t(0)))>::type
5073     >
5074   : true_type {};
5075
5076// __builtin_new_allocator -- A non-templated helper for allocating and
5077// deallocating memory using __builtin_operator_new and
5078// __builtin_operator_delete. It should be used in preference to
5079// `std::allocator<T>` to avoid additional instantiations.
5080struct __builtin_new_allocator {
5081  struct __builtin_new_deleter {
5082    typedef void* pointer_type;
5083
5084    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
5085        : __size_(__size), __align_(__align) {}
5086
5087    void operator()(void* p) const _NOEXCEPT {
5088        std::__libcpp_deallocate(p, __size_, __align_);
5089    }
5090
5091   private:
5092    size_t __size_;
5093    size_t __align_;
5094  };
5095
5096  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
5097
5098  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
5099      return __holder_t(std::__libcpp_allocate(__s, __align),
5100                     __builtin_new_deleter(__s, __align));
5101  }
5102
5103  static void __deallocate_bytes(void* __p, size_t __s,
5104                                 size_t __align) _NOEXCEPT {
5105      std::__libcpp_deallocate(__p, __s, __align);
5106  }
5107
5108  template <class _Tp>
5109  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5110  static __holder_t __allocate_type(size_t __n) {
5111      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5112  }
5113
5114  template <class _Tp>
5115  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5116  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
5117      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5118  }
5119};
5120
5121
5122_LIBCPP_END_NAMESPACE_STD
5123
5124_LIBCPP_POP_MACROS
5125
5126#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
5127#   include <__pstl_memory>
5128#endif
5129
5130#endif  // _LIBCPP_MEMORY
5131