xref: /llvm-project-15.0.7/libcxx/include/memory (revision 219b2b3a)
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<U>::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>
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;
121    typedef const T*                              const_pointer;
122    typedef typename add_lvalue_reference<T>::type       reference;
123    typedef typename add_lvalue_reference<const T>::type const_reference;
124    typedef T                                     value_type;
125
126    template <class U> struct rebind {typedef allocator<U> other;};
127
128    constexpr allocator() noexcept;                      // constexpr in C++20
129    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
130    template <class U>
131      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
132    ~allocator();
133    pointer address(reference x) const noexcept;
134    const_pointer address(const_reference x) const noexcept;
135    pointer allocate(size_type, allocator<void>::const_pointer hint = 0);
136    void deallocate(pointer p, size_type n) noexcept;
137    size_type max_size() const noexcept;
138    template<class U, class... Args>
139        void construct(U* p, Args&&... args);
140    template <class U>
141        void destroy(U* p);
142};
143
144template <class T, class U>
145bool operator==(const allocator<T>&, const allocator<U>&) noexcept;
146
147template <class T, class U>
148bool operator!=(const allocator<T>&, const allocator<U>&) noexcept;
149
150template <class OutputIterator, class T>
151class raw_storage_iterator
152    : public iterator<output_iterator_tag,
153                      T,                               // purposefully not C++03
154                      ptrdiff_t,                       // purposefully not C++03
155                      T*,                              // purposefully not C++03
156                      raw_storage_iterator&>           // purposefully not C++03
157{
158public:
159    explicit raw_storage_iterator(OutputIterator x);
160    raw_storage_iterator& operator*();
161    raw_storage_iterator& operator=(const T& element);
162    raw_storage_iterator& operator++();
163    raw_storage_iterator  operator++(int);
164};
165
166template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
167template <class T> void               return_temporary_buffer(T* p) noexcept;
168
169template <class T> T* addressof(T& r) noexcept;
170template <class T> T* addressof(const T&& r) noexcept = delete;
171
172template <class InputIterator, class ForwardIterator>
173ForwardIterator
174uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
175
176template <class InputIterator, class Size, class ForwardIterator>
177ForwardIterator
178uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
179
180template <class ForwardIterator, class T>
181void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
182
183template <class ForwardIterator, class Size, class T>
184ForwardIterator
185uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
186
187template <class T>
188void destroy_at(T* location);
189
190template <class ForwardIterator>
191 void destroy(ForwardIterator first, ForwardIterator last);
192
193template <class ForwardIterator, class Size>
194 ForwardIterator destroy_n(ForwardIterator first, Size n);
195
196template <class InputIterator, class ForwardIterator>
197 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
198
199template <class InputIterator, class Size, class ForwardIterator>
200 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
201
202template <class ForwardIterator>
203 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
204
205template <class ForwardIterator, class Size>
206 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
207
208template <class ForwardIterator>
209 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
210
211template <class ForwardIterator, class Size>
212 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
213
214template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
215
216template<class X>
217class auto_ptr                                  // deprecated in C++11, removed in C++17
218{
219public:
220    typedef X element_type;
221
222    explicit auto_ptr(X* p =0) throw();
223    auto_ptr(auto_ptr&) throw();
224    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
225    auto_ptr& operator=(auto_ptr&) throw();
226    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
227    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
228    ~auto_ptr() throw();
229
230    typename add_lvalue_reference<X>::type operator*() const throw();
231    X* operator->() const throw();
232    X* get() const throw();
233    X* release() throw();
234    void reset(X* p =0) throw();
235
236    auto_ptr(auto_ptr_ref<X>) throw();
237    template<class Y> operator auto_ptr_ref<Y>() throw();
238    template<class Y> operator auto_ptr<Y>() throw();
239};
240
241template <class T>
242struct default_delete
243{
244    constexpr default_delete() noexcept = default;
245    template <class U> default_delete(const default_delete<U>&) noexcept;
246
247    void operator()(T*) const noexcept;
248};
249
250template <class T>
251struct default_delete<T[]>
252{
253    constexpr default_delete() noexcept = default;
254    void operator()(T*) const noexcept;
255    template <class U> void operator()(U*) const = delete;
256};
257
258template <class T, class D = default_delete<T>>
259class unique_ptr
260{
261public:
262    typedef see below pointer;
263    typedef T element_type;
264    typedef D deleter_type;
265
266    // constructors
267    constexpr unique_ptr() noexcept;
268    explicit unique_ptr(pointer p) noexcept;
269    unique_ptr(pointer p, see below d1) noexcept;
270    unique_ptr(pointer p, see below d2) noexcept;
271    unique_ptr(unique_ptr&& u) noexcept;
272    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
273    template <class U, class E>
274        unique_ptr(unique_ptr<U, E>&& u) noexcept;
275    template <class U>
276        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
277
278    // destructor
279    ~unique_ptr();
280
281    // assignment
282    unique_ptr& operator=(unique_ptr&& u) noexcept;
283    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
284    unique_ptr& operator=(nullptr_t) noexcept;
285
286    // observers
287    typename add_lvalue_reference<T>::type operator*() const;
288    pointer operator->() const noexcept;
289    pointer get() const noexcept;
290    deleter_type& get_deleter() noexcept;
291    const deleter_type& get_deleter() const noexcept;
292    explicit operator bool() const noexcept;
293
294    // modifiers
295    pointer release() noexcept;
296    void reset(pointer p = pointer()) noexcept;
297    void swap(unique_ptr& u) noexcept;
298};
299
300template <class T, class D>
301class unique_ptr<T[], D>
302{
303public:
304    typedef implementation-defined pointer;
305    typedef T element_type;
306    typedef D deleter_type;
307
308    // constructors
309    constexpr unique_ptr() noexcept;
310    explicit unique_ptr(pointer p) noexcept;
311    unique_ptr(pointer p, see below d) noexcept;
312    unique_ptr(pointer p, see below d) noexcept;
313    unique_ptr(unique_ptr&& u) noexcept;
314    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
315
316    // destructor
317    ~unique_ptr();
318
319    // assignment
320    unique_ptr& operator=(unique_ptr&& u) noexcept;
321    unique_ptr& operator=(nullptr_t) noexcept;
322
323    // observers
324    T& operator[](size_t i) const;
325    pointer get() const noexcept;
326    deleter_type& get_deleter() noexcept;
327    const deleter_type& get_deleter() const noexcept;
328    explicit operator bool() const noexcept;
329
330    // modifiers
331    pointer release() noexcept;
332    void reset(pointer p = pointer()) noexcept;
333    void reset(nullptr_t) noexcept;
334    template <class U> void reset(U) = delete;
335    void swap(unique_ptr& u) noexcept;
336};
337
338template <class T, class D>
339    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
340
341template <class T1, class D1, class T2, class D2>
342    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
343template <class T1, class D1, class T2, class D2>
344    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
345template <class T1, class D1, class T2, class D2>
346    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
347template <class T1, class D1, class T2, class D2>
348    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
349template <class T1, class D1, class T2, class D2>
350    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
351template <class T1, class D1, class T2, class D2>
352    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
353
354template <class T, class D>
355    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
356template <class T, class D>
357    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
358template <class T, class D>
359    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
360template <class T, class D>
361    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
362
363template <class T, class D>
364    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
365template <class T, class D>
366    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
367template <class T, class D>
368    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
369template <class T, class D>
370    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
371template <class T, class D>
372    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
373template <class T, class D>
374    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
375template <class T, class D>
376    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
377template <class T, class D>
378    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
379
380class bad_weak_ptr
381    : public std::exception
382{
383    bad_weak_ptr() noexcept;
384};
385
386template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
387template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
388template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
389
390template<class E, class T, class Y, class D>
391    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
392
393template<class T>
394class shared_ptr
395{
396public:
397    typedef T element_type;
398    typedef weak_ptr<T> weak_type; // C++17
399
400    // constructors:
401    constexpr shared_ptr() noexcept;
402    template<class Y> explicit shared_ptr(Y* p);
403    template<class Y, class D> shared_ptr(Y* p, D d);
404    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
405    template <class D> shared_ptr(nullptr_t p, D d);
406    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
407    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
408    shared_ptr(const shared_ptr& r) noexcept;
409    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
410    shared_ptr(shared_ptr&& r) noexcept;
411    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
412    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
413    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
414    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
415    shared_ptr(nullptr_t) : shared_ptr() { }
416
417    // destructor:
418    ~shared_ptr();
419
420    // assignment:
421    shared_ptr& operator=(const shared_ptr& r) noexcept;
422    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
423    shared_ptr& operator=(shared_ptr&& r) noexcept;
424    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
425    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
426    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
427
428    // modifiers:
429    void swap(shared_ptr& r) noexcept;
430    void reset() noexcept;
431    template<class Y> void reset(Y* p);
432    template<class Y, class D> void reset(Y* p, D d);
433    template<class Y, class D, class A> void reset(Y* p, D d, A a);
434
435    // observers:
436    T* get() const noexcept;
437    T& operator*() const noexcept;
438    T* operator->() const noexcept;
439    long use_count() const noexcept;
440    bool unique() const noexcept;
441    explicit operator bool() const noexcept;
442    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
443    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
444};
445
446// shared_ptr comparisons:
447template<class T, class U>
448    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
449template<class T, class U>
450    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
451template<class T, class U>
452    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
453template<class T, class U>
454    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
455template<class T, class U>
456    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
457template<class T, class U>
458    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
459
460template <class T>
461    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
462template <class T>
463    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
464template <class T>
465    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
466template <class T>
467    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
468template <class T>
469    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
470template <class T>
471bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
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>
483    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
484
485// shared_ptr specialized algorithms:
486template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
487
488// shared_ptr casts:
489template<class T, class U>
490    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
491template<class T, class U>
492    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
493template<class T, class U>
494    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
495
496// shared_ptr I/O:
497template<class E, class T, class Y>
498    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
499
500// shared_ptr get_deleter:
501template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
502
503template<class T, class... Args>
504    shared_ptr<T> make_shared(Args&&... args);
505template<class T, class A, class... Args>
506    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
507
508template<class T>
509class weak_ptr
510{
511public:
512    typedef T element_type;
513
514    // constructors
515    constexpr weak_ptr() noexcept;
516    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
517    weak_ptr(weak_ptr const& r) noexcept;
518    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
519    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
520    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
521
522    // destructor
523    ~weak_ptr();
524
525    // assignment
526    weak_ptr& operator=(weak_ptr const& r) noexcept;
527    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
528    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
529    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
530    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
531
532    // modifiers
533    void swap(weak_ptr& r) noexcept;
534    void reset() noexcept;
535
536    // observers
537    long use_count() const noexcept;
538    bool expired() const noexcept;
539    shared_ptr<T> lock() const noexcept;
540    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
541    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
542};
543
544// weak_ptr specialized algorithms:
545template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
546
547// class owner_less:
548template<class T> struct owner_less;
549
550template<class T>
551struct owner_less<shared_ptr<T>>
552    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
553{
554    typedef bool result_type;
555    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
556    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
557    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
558};
559
560template<class T>
561struct owner_less<weak_ptr<T>>
562    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
563{
564    typedef bool result_type;
565    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
566    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
567    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
568};
569
570template <>  // Added in C++14
571struct owner_less<void>
572{
573    template <class _Tp, class _Up>
574    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
575    template <class _Tp, class _Up>
576    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
577    template <class _Tp, class _Up>
578    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
579    template <class _Tp, class _Up>
580    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
581
582    typedef void is_transparent;
583};
584
585template<class T>
586class enable_shared_from_this
587{
588protected:
589    constexpr enable_shared_from_this() noexcept;
590    enable_shared_from_this(enable_shared_from_this const&) noexcept;
591    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
592    ~enable_shared_from_this();
593public:
594    shared_ptr<T> shared_from_this();
595    shared_ptr<T const> shared_from_this() const;
596};
597
598template<class T>
599    bool atomic_is_lock_free(const shared_ptr<T>* p);
600template<class T>
601    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
602template<class T>
603    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
604template<class T>
605    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
606template<class T>
607    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
608template<class T>
609    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
610template<class T>
611    shared_ptr<T>
612    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
613template<class T>
614    bool
615    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
616template<class T>
617    bool
618    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
619template<class T>
620    bool
621    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
622                                          shared_ptr<T> w, memory_order success,
623                                          memory_order failure);
624template<class T>
625    bool
626    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
627                                            shared_ptr<T> w, memory_order success,
628                                            memory_order failure);
629// Hash support
630template <class T> struct hash;
631template <class T, class D> struct hash<unique_ptr<T, D> >;
632template <class T> struct hash<shared_ptr<T> >;
633
634template <class T, class Alloc>
635  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
636
637// Pointer safety
638enum class pointer_safety { relaxed, preferred, strict };
639void declare_reachable(void *p);
640template <class T> T *undeclare_reachable(T *p);
641void declare_no_pointers(char *p, size_t n);
642void undeclare_no_pointers(char *p, size_t n);
643pointer_safety get_pointer_safety() noexcept;
644
645void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
646
647}  // std
648
649*/
650
651#include <__config>
652#include <type_traits>
653#include <typeinfo>
654#include <cstddef>
655#include <cstdint>
656#include <new>
657#include <utility>
658#include <limits>
659#include <iterator>
660#include <__functional_base>
661#include <iosfwd>
662#include <tuple>
663#include <stdexcept>
664#include <cstring>
665#include <cassert>
666#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
667#  include <atomic>
668#endif
669#include <version>
670
671#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
672#pragma GCC system_header
673#endif
674
675_LIBCPP_PUSH_MACROS
676#include <__undef_macros>
677
678
679_LIBCPP_BEGIN_NAMESPACE_STD
680
681template <class _ValueType>
682inline _LIBCPP_INLINE_VISIBILITY
683_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
684#if !defined(_LIBCPP_HAS_NO_THREADS) && \
685    defined(__ATOMIC_RELAXED) &&        \
686    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
687    return __atomic_load_n(__value, __ATOMIC_RELAXED);
688#else
689    return *__value;
690#endif
691}
692
693template <class _ValueType>
694inline _LIBCPP_INLINE_VISIBILITY
695_ValueType __libcpp_acquire_load(_ValueType const* __value) {
696#if !defined(_LIBCPP_HAS_NO_THREADS) && \
697    defined(__ATOMIC_ACQUIRE) &&        \
698    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
699    return __atomic_load_n(__value, __ATOMIC_ACQUIRE);
700#else
701    return *__value;
702#endif
703}
704
705// addressof moved to <type_traits>
706
707template <class _Tp> class allocator;
708
709template <>
710class _LIBCPP_TEMPLATE_VIS allocator<void>
711{
712public:
713    typedef void*             pointer;
714    typedef const void*       const_pointer;
715    typedef void              value_type;
716
717    template <class _Up> struct rebind {typedef allocator<_Up> other;};
718};
719
720template <>
721class _LIBCPP_TEMPLATE_VIS allocator<const void>
722{
723public:
724    typedef const void*       pointer;
725    typedef const void*       const_pointer;
726    typedef const void        value_type;
727
728    template <class _Up> struct rebind {typedef allocator<_Up> other;};
729};
730
731// pointer_traits
732
733template <class _Tp, class = void>
734struct __has_element_type : false_type {};
735
736template <class _Tp>
737struct __has_element_type<_Tp,
738              typename __void_t<typename _Tp::element_type>::type> : true_type {};
739
740template <class _Ptr, bool = __has_element_type<_Ptr>::value>
741struct __pointer_traits_element_type;
742
743template <class _Ptr>
744struct __pointer_traits_element_type<_Ptr, true>
745{
746    typedef typename _Ptr::element_type type;
747};
748
749#ifndef _LIBCPP_HAS_NO_VARIADICS
750
751template <template <class, class...> class _Sp, class _Tp, class ..._Args>
752struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
753{
754    typedef typename _Sp<_Tp, _Args...>::element_type type;
755};
756
757template <template <class, class...> class _Sp, class _Tp, class ..._Args>
758struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
759{
760    typedef _Tp type;
761};
762
763#else  // _LIBCPP_HAS_NO_VARIADICS
764
765template <template <class> class _Sp, class _Tp>
766struct __pointer_traits_element_type<_Sp<_Tp>, true>
767{
768    typedef typename _Sp<_Tp>::element_type type;
769};
770
771template <template <class> class _Sp, class _Tp>
772struct __pointer_traits_element_type<_Sp<_Tp>, false>
773{
774    typedef _Tp type;
775};
776
777template <template <class, class> class _Sp, class _Tp, class _A0>
778struct __pointer_traits_element_type<_Sp<_Tp, _A0>, true>
779{
780    typedef typename _Sp<_Tp, _A0>::element_type type;
781};
782
783template <template <class, class> class _Sp, class _Tp, class _A0>
784struct __pointer_traits_element_type<_Sp<_Tp, _A0>, false>
785{
786    typedef _Tp type;
787};
788
789template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
790struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, true>
791{
792    typedef typename _Sp<_Tp, _A0, _A1>::element_type type;
793};
794
795template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
796struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, false>
797{
798    typedef _Tp type;
799};
800
801template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
802                                                           class _A1, class _A2>
803struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, true>
804{
805    typedef typename _Sp<_Tp, _A0, _A1, _A2>::element_type type;
806};
807
808template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
809                                                           class _A1, class _A2>
810struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, false>
811{
812    typedef _Tp type;
813};
814
815#endif  // _LIBCPP_HAS_NO_VARIADICS
816
817template <class _Tp, class = void>
818struct __has_difference_type : false_type {};
819
820template <class _Tp>
821struct __has_difference_type<_Tp,
822            typename __void_t<typename _Tp::difference_type>::type> : true_type {};
823
824template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
825struct __pointer_traits_difference_type
826{
827    typedef ptrdiff_t type;
828};
829
830template <class _Ptr>
831struct __pointer_traits_difference_type<_Ptr, true>
832{
833    typedef typename _Ptr::difference_type type;
834};
835
836template <class _Tp, class _Up>
837struct __has_rebind
838{
839private:
840    struct __two {char __lx; char __lxx;};
841    template <class _Xp> static __two __test(...);
842    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
843public:
844    static const bool value = sizeof(__test<_Tp>(0)) == 1;
845};
846
847template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
848struct __pointer_traits_rebind
849{
850#ifndef _LIBCPP_CXX03_LANG
851    typedef typename _Tp::template rebind<_Up> type;
852#else
853    typedef typename _Tp::template rebind<_Up>::other type;
854#endif
855};
856
857#ifndef _LIBCPP_HAS_NO_VARIADICS
858
859template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
860struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
861{
862#ifndef _LIBCPP_CXX03_LANG
863    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
864#else
865    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
866#endif
867};
868
869template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
870struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
871{
872    typedef _Sp<_Up, _Args...> type;
873};
874
875#else  // _LIBCPP_HAS_NO_VARIADICS
876
877template <template <class> class _Sp, class _Tp, class _Up>
878struct __pointer_traits_rebind<_Sp<_Tp>, _Up, true>
879{
880#ifndef _LIBCPP_CXX03_LANG
881    typedef typename _Sp<_Tp>::template rebind<_Up> type;
882#else
883    typedef typename _Sp<_Tp>::template rebind<_Up>::other type;
884#endif
885};
886
887template <template <class> class _Sp, class _Tp, class _Up>
888struct __pointer_traits_rebind<_Sp<_Tp>, _Up, false>
889{
890    typedef _Sp<_Up> type;
891};
892
893template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
894struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, true>
895{
896#ifndef _LIBCPP_CXX03_LANG
897    typedef typename _Sp<_Tp, _A0>::template rebind<_Up> type;
898#else
899    typedef typename _Sp<_Tp, _A0>::template rebind<_Up>::other type;
900#endif
901};
902
903template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
904struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, false>
905{
906    typedef _Sp<_Up, _A0> type;
907};
908
909template <template <class, class, class> class _Sp, class _Tp, class _A0,
910                                         class _A1, class _Up>
911struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, true>
912{
913#ifndef _LIBCPP_CXX03_LANG
914    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up> type;
915#else
916    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up>::other type;
917#endif
918};
919
920template <template <class, class, class> class _Sp, class _Tp, class _A0,
921                                         class _A1, class _Up>
922struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, false>
923{
924    typedef _Sp<_Up, _A0, _A1> type;
925};
926
927template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
928                                                class _A1, class _A2, class _Up>
929struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, true>
930{
931#ifndef _LIBCPP_CXX03_LANG
932    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up> type;
933#else
934    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
935#endif
936};
937
938template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
939                                                class _A1, class _A2, class _Up>
940struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, false>
941{
942    typedef _Sp<_Up, _A0, _A1, _A2> type;
943};
944
945#endif  // _LIBCPP_HAS_NO_VARIADICS
946
947template <class _Ptr>
948struct _LIBCPP_TEMPLATE_VIS pointer_traits
949{
950    typedef _Ptr                                                     pointer;
951    typedef typename __pointer_traits_element_type<pointer>::type    element_type;
952    typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
953
954#ifndef _LIBCPP_CXX03_LANG
955    template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
956#else
957    template <class _Up> struct rebind
958        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
959#endif  // _LIBCPP_CXX03_LANG
960
961private:
962    struct __nat {};
963public:
964    _LIBCPP_INLINE_VISIBILITY
965    static pointer pointer_to(typename conditional<is_void<element_type>::value,
966                                           __nat, element_type>::type& __r)
967        {return pointer::pointer_to(__r);}
968};
969
970template <class _Tp>
971struct _LIBCPP_TEMPLATE_VIS pointer_traits<_Tp*>
972{
973    typedef _Tp*      pointer;
974    typedef _Tp       element_type;
975    typedef ptrdiff_t difference_type;
976
977#ifndef _LIBCPP_CXX03_LANG
978    template <class _Up> using rebind = _Up*;
979#else
980    template <class _Up> struct rebind {typedef _Up* other;};
981#endif
982
983private:
984    struct __nat {};
985public:
986    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
987    static pointer pointer_to(typename conditional<is_void<element_type>::value,
988                                      __nat, element_type>::type& __r) _NOEXCEPT
989        {return _VSTD::addressof(__r);}
990};
991
992template <class _From, class _To>
993struct __rebind_pointer {
994#ifndef _LIBCPP_CXX03_LANG
995    typedef typename pointer_traits<_From>::template rebind<_To>        type;
996#else
997    typedef typename pointer_traits<_From>::template rebind<_To>::other type;
998#endif
999};
1000
1001// allocator_traits
1002
1003template <class _Tp, class = void>
1004struct __has_pointer_type : false_type {};
1005
1006template <class _Tp>
1007struct __has_pointer_type<_Tp,
1008          typename __void_t<typename _Tp::pointer>::type> : true_type {};
1009
1010namespace __pointer_type_imp
1011{
1012
1013template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
1014struct __pointer_type
1015{
1016    typedef typename _Dp::pointer type;
1017};
1018
1019template <class _Tp, class _Dp>
1020struct __pointer_type<_Tp, _Dp, false>
1021{
1022    typedef _Tp* type;
1023};
1024
1025}  // __pointer_type_imp
1026
1027template <class _Tp, class _Dp>
1028struct __pointer_type
1029{
1030    typedef typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
1031};
1032
1033template <class _Tp, class = void>
1034struct __has_const_pointer : false_type {};
1035
1036template <class _Tp>
1037struct __has_const_pointer<_Tp,
1038            typename __void_t<typename _Tp::const_pointer>::type> : true_type {};
1039
1040template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
1041struct __const_pointer
1042{
1043    typedef typename _Alloc::const_pointer type;
1044};
1045
1046template <class _Tp, class _Ptr, class _Alloc>
1047struct __const_pointer<_Tp, _Ptr, _Alloc, false>
1048{
1049#ifndef _LIBCPP_CXX03_LANG
1050    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
1051#else
1052    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
1053#endif
1054};
1055
1056template <class _Tp, class = void>
1057struct __has_void_pointer : false_type {};
1058
1059template <class _Tp>
1060struct __has_void_pointer<_Tp,
1061               typename __void_t<typename _Tp::void_pointer>::type> : true_type {};
1062
1063template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
1064struct __void_pointer
1065{
1066    typedef typename _Alloc::void_pointer type;
1067};
1068
1069template <class _Ptr, class _Alloc>
1070struct __void_pointer<_Ptr, _Alloc, false>
1071{
1072#ifndef _LIBCPP_CXX03_LANG
1073    typedef typename pointer_traits<_Ptr>::template rebind<void> type;
1074#else
1075    typedef typename pointer_traits<_Ptr>::template rebind<void>::other type;
1076#endif
1077};
1078
1079template <class _Tp, class = void>
1080struct __has_const_void_pointer : false_type {};
1081
1082template <class _Tp>
1083struct __has_const_void_pointer<_Tp,
1084            typename __void_t<typename _Tp::const_void_pointer>::type> : true_type {};
1085
1086template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
1087struct __const_void_pointer
1088{
1089    typedef typename _Alloc::const_void_pointer type;
1090};
1091
1092template <class _Ptr, class _Alloc>
1093struct __const_void_pointer<_Ptr, _Alloc, false>
1094{
1095#ifndef _LIBCPP_CXX03_LANG
1096    typedef typename pointer_traits<_Ptr>::template rebind<const void> type;
1097#else
1098    typedef typename pointer_traits<_Ptr>::template rebind<const void>::other type;
1099#endif
1100};
1101
1102template <class _Tp>
1103inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1104_Tp*
1105__to_raw_pointer(_Tp* __p) _NOEXCEPT
1106{
1107    return __p;
1108}
1109
1110#if _LIBCPP_STD_VER <= 17
1111template <class _Pointer>
1112inline _LIBCPP_INLINE_VISIBILITY
1113typename pointer_traits<_Pointer>::element_type*
1114__to_raw_pointer(_Pointer __p) _NOEXCEPT
1115{
1116    return _VSTD::__to_raw_pointer(__p.operator->());
1117}
1118#else
1119template <class _Pointer>
1120inline _LIBCPP_INLINE_VISIBILITY
1121auto
1122__to_raw_pointer(const _Pointer& __p) _NOEXCEPT
1123-> decltype(pointer_traits<_Pointer>::to_address(__p))
1124{
1125    return pointer_traits<_Pointer>::to_address(__p);
1126}
1127
1128template <class _Pointer, class... _None>
1129inline _LIBCPP_INLINE_VISIBILITY
1130auto
1131__to_raw_pointer(const _Pointer& __p, _None...) _NOEXCEPT
1132{
1133    return _VSTD::__to_raw_pointer(__p.operator->());
1134}
1135
1136template <class _Tp>
1137inline _LIBCPP_INLINE_VISIBILITY constexpr
1138_Tp*
1139to_address(_Tp* __p) _NOEXCEPT
1140{
1141    static_assert(!is_function_v<_Tp>, "_Tp is a function type");
1142    return __p;
1143}
1144
1145template <class _Pointer>
1146inline _LIBCPP_INLINE_VISIBILITY
1147auto
1148to_address(const _Pointer& __p) _NOEXCEPT
1149{
1150    return _VSTD::__to_raw_pointer(__p);
1151}
1152#endif
1153
1154template <class _Tp, class = void>
1155struct __has_size_type : false_type {};
1156
1157template <class _Tp>
1158struct __has_size_type<_Tp,
1159               typename __void_t<typename _Tp::size_type>::type> : true_type {};
1160
1161template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
1162struct __size_type
1163{
1164    typedef typename make_unsigned<_DiffType>::type type;
1165};
1166
1167template <class _Alloc, class _DiffType>
1168struct __size_type<_Alloc, _DiffType, true>
1169{
1170    typedef typename _Alloc::size_type type;
1171};
1172
1173template <class _Tp, class = void>
1174struct __has_propagate_on_container_copy_assignment : false_type {};
1175
1176template <class _Tp>
1177struct __has_propagate_on_container_copy_assignment<_Tp,
1178    typename __void_t<typename _Tp::propagate_on_container_copy_assignment>::type>
1179        : true_type {};
1180
1181template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
1182struct __propagate_on_container_copy_assignment
1183{
1184    typedef false_type type;
1185};
1186
1187template <class _Alloc>
1188struct __propagate_on_container_copy_assignment<_Alloc, true>
1189{
1190    typedef typename _Alloc::propagate_on_container_copy_assignment type;
1191};
1192
1193template <class _Tp, class = void>
1194struct __has_propagate_on_container_move_assignment : false_type {};
1195
1196template <class _Tp>
1197struct __has_propagate_on_container_move_assignment<_Tp,
1198           typename __void_t<typename _Tp::propagate_on_container_move_assignment>::type>
1199               : true_type {};
1200
1201template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
1202struct __propagate_on_container_move_assignment
1203{
1204    typedef false_type type;
1205};
1206
1207template <class _Alloc>
1208struct __propagate_on_container_move_assignment<_Alloc, true>
1209{
1210    typedef typename _Alloc::propagate_on_container_move_assignment type;
1211};
1212
1213template <class _Tp, class = void>
1214struct __has_propagate_on_container_swap : false_type {};
1215
1216template <class _Tp>
1217struct __has_propagate_on_container_swap<_Tp,
1218           typename __void_t<typename _Tp::propagate_on_container_swap>::type>
1219               : true_type {};
1220
1221template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
1222struct __propagate_on_container_swap
1223{
1224    typedef false_type type;
1225};
1226
1227template <class _Alloc>
1228struct __propagate_on_container_swap<_Alloc, true>
1229{
1230    typedef typename _Alloc::propagate_on_container_swap type;
1231};
1232
1233template <class _Tp, class = void>
1234struct __has_is_always_equal : false_type {};
1235
1236template <class _Tp>
1237struct __has_is_always_equal<_Tp,
1238           typename __void_t<typename _Tp::is_always_equal>::type>
1239               : true_type {};
1240
1241template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
1242struct __is_always_equal
1243{
1244    typedef typename _VSTD::is_empty<_Alloc>::type type;
1245};
1246
1247template <class _Alloc>
1248struct __is_always_equal<_Alloc, true>
1249{
1250    typedef typename _Alloc::is_always_equal type;
1251};
1252
1253template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
1254struct __has_rebind_other
1255{
1256private:
1257    struct __two {char __lx; char __lxx;};
1258    template <class _Xp> static __two __test(...);
1259    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
1260public:
1261    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1262};
1263
1264template <class _Tp, class _Up>
1265struct __has_rebind_other<_Tp, _Up, false>
1266{
1267    static const bool value = false;
1268};
1269
1270template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
1271struct __allocator_traits_rebind
1272{
1273    typedef typename _Tp::template rebind<_Up>::other type;
1274};
1275
1276#ifndef _LIBCPP_HAS_NO_VARIADICS
1277
1278template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1279struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
1280{
1281    typedef typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
1282};
1283
1284template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1285struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
1286{
1287    typedef _Alloc<_Up, _Args...> type;
1288};
1289
1290#else  // _LIBCPP_HAS_NO_VARIADICS
1291
1292template <template <class> class _Alloc, class _Tp, class _Up>
1293struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, true>
1294{
1295    typedef typename _Alloc<_Tp>::template rebind<_Up>::other type;
1296};
1297
1298template <template <class> class _Alloc, class _Tp, class _Up>
1299struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, false>
1300{
1301    typedef _Alloc<_Up> type;
1302};
1303
1304template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1305struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, true>
1306{
1307    typedef typename _Alloc<_Tp, _A0>::template rebind<_Up>::other type;
1308};
1309
1310template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1311struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, false>
1312{
1313    typedef _Alloc<_Up, _A0> type;
1314};
1315
1316template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1317                                         class _A1, class _Up>
1318struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, true>
1319{
1320    typedef typename _Alloc<_Tp, _A0, _A1>::template rebind<_Up>::other type;
1321};
1322
1323template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1324                                         class _A1, class _Up>
1325struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, false>
1326{
1327    typedef _Alloc<_Up, _A0, _A1> type;
1328};
1329
1330template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1331                                                class _A1, class _A2, class _Up>
1332struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, true>
1333{
1334    typedef typename _Alloc<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
1335};
1336
1337template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1338                                                class _A1, class _A2, class _Up>
1339struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, false>
1340{
1341    typedef _Alloc<_Up, _A0, _A1, _A2> type;
1342};
1343
1344#endif  // _LIBCPP_HAS_NO_VARIADICS
1345
1346#ifndef _LIBCPP_CXX03_LANG
1347
1348template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1349auto
1350__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1351    -> decltype((void)__a.allocate(__sz, __p), true_type());
1352
1353template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1354auto
1355__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1356    -> false_type;
1357
1358template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1359struct __has_allocate_hint
1360    : integral_constant<bool,
1361        is_same<
1362            decltype(_VSTD::__has_allocate_hint_test(declval<_Alloc>(),
1363                                          declval<_SizeType>(),
1364                                          declval<_ConstVoidPtr>())),
1365            true_type>::value>
1366{
1367};
1368
1369#else  // _LIBCPP_CXX03_LANG
1370
1371template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1372struct __has_allocate_hint
1373    : true_type
1374{
1375};
1376
1377#endif  // _LIBCPP_CXX03_LANG
1378
1379#if !defined(_LIBCPP_CXX03_LANG)
1380
1381template <class _Alloc, class _Tp, class ..._Args>
1382decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Tp*>(),
1383                                           _VSTD::declval<_Args>()...),
1384                                           true_type())
1385__has_construct_test(_Alloc&& __a, _Tp* __p, _Args&& ...__args);
1386
1387template <class _Alloc, class _Pointer, class ..._Args>
1388false_type
1389__has_construct_test(const _Alloc& __a, _Pointer&& __p, _Args&& ...__args);
1390
1391template <class _Alloc, class _Pointer, class ..._Args>
1392struct __has_construct
1393    : integral_constant<bool,
1394        is_same<
1395            decltype(_VSTD::__has_construct_test(declval<_Alloc>(),
1396                                          declval<_Pointer>(),
1397                                          declval<_Args>()...)),
1398            true_type>::value>
1399{
1400};
1401
1402template <class _Alloc, class _Pointer>
1403auto
1404__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
1405    -> decltype(__a.destroy(__p), true_type());
1406
1407template <class _Alloc, class _Pointer>
1408auto
1409__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
1410    -> false_type;
1411
1412template <class _Alloc, class _Pointer>
1413struct __has_destroy
1414    : integral_constant<bool,
1415        is_same<
1416            decltype(_VSTD::__has_destroy_test(declval<_Alloc>(),
1417                                        declval<_Pointer>())),
1418            true_type>::value>
1419{
1420};
1421
1422template <class _Alloc>
1423auto
1424__has_max_size_test(_Alloc&& __a)
1425    -> decltype(__a.max_size(), true_type());
1426
1427template <class _Alloc>
1428auto
1429__has_max_size_test(const volatile _Alloc& __a)
1430    -> false_type;
1431
1432template <class _Alloc>
1433struct __has_max_size
1434    : integral_constant<bool,
1435        is_same<
1436            decltype(_VSTD::__has_max_size_test(declval<_Alloc&>())),
1437            true_type>::value>
1438{
1439};
1440
1441template <class _Alloc>
1442auto
1443__has_select_on_container_copy_construction_test(_Alloc&& __a)
1444    -> decltype(__a.select_on_container_copy_construction(), true_type());
1445
1446template <class _Alloc>
1447auto
1448__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
1449    -> false_type;
1450
1451template <class _Alloc>
1452struct __has_select_on_container_copy_construction
1453    : integral_constant<bool,
1454        is_same<
1455            decltype(_VSTD::__has_select_on_container_copy_construction_test(declval<_Alloc&>())),
1456            true_type>::value>
1457{
1458};
1459
1460#else  // _LIBCPP_CXX03_LANG
1461
1462template <class _Alloc, class _Pointer, class _Tp, class = void>
1463struct __has_construct : std::false_type {};
1464
1465template <class _Alloc, class _Pointer, class _Tp>
1466struct __has_construct<_Alloc, _Pointer, _Tp, typename __void_t<
1467    decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Pointer>(), _VSTD::declval<_Tp>()))
1468>::type> : std::true_type {};
1469
1470template <class _Alloc, class _Pointer, class = void>
1471struct __has_destroy : false_type {};
1472
1473template <class _Alloc, class _Pointer>
1474struct __has_destroy<_Alloc, _Pointer, typename __void_t<
1475    decltype(_VSTD::declval<_Alloc>().destroy(_VSTD::declval<_Pointer>()))
1476>::type> : std::true_type {};
1477
1478template <class _Alloc>
1479struct __has_max_size
1480    : true_type
1481{
1482};
1483
1484template <class _Alloc>
1485struct __has_select_on_container_copy_construction
1486    : false_type
1487{
1488};
1489
1490#endif  // _LIBCPP_CXX03_LANG
1491
1492template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
1493struct __alloc_traits_difference_type
1494{
1495    typedef typename pointer_traits<_Ptr>::difference_type type;
1496};
1497
1498template <class _Alloc, class _Ptr>
1499struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
1500{
1501    typedef typename _Alloc::difference_type type;
1502};
1503
1504template <class _Tp>
1505struct __is_default_allocator : false_type {};
1506
1507template <class _Tp>
1508struct __is_default_allocator<_VSTD::allocator<_Tp> > : true_type {};
1509
1510template <class _Alloc>
1511struct _LIBCPP_TEMPLATE_VIS allocator_traits
1512{
1513    typedef _Alloc                              allocator_type;
1514    typedef typename allocator_type::value_type value_type;
1515
1516    typedef typename __pointer_type<value_type, allocator_type>::type pointer;
1517    typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
1518    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
1519    typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;
1520
1521    typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
1522    typedef typename __size_type<allocator_type, difference_type>::type size_type;
1523
1524    typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
1525                     propagate_on_container_copy_assignment;
1526    typedef typename __propagate_on_container_move_assignment<allocator_type>::type
1527                     propagate_on_container_move_assignment;
1528    typedef typename __propagate_on_container_swap<allocator_type>::type
1529                     propagate_on_container_swap;
1530    typedef typename __is_always_equal<allocator_type>::type
1531                     is_always_equal;
1532
1533#ifndef _LIBCPP_CXX03_LANG
1534    template <class _Tp> using rebind_alloc =
1535                  typename __allocator_traits_rebind<allocator_type, _Tp>::type;
1536    template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp>>;
1537#else  // _LIBCPP_CXX03_LANG
1538    template <class _Tp> struct rebind_alloc
1539        {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
1540    template <class _Tp> struct rebind_traits
1541        {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
1542#endif  // _LIBCPP_CXX03_LANG
1543
1544    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1545    static pointer allocate(allocator_type& __a, size_type __n)
1546        {return __a.allocate(__n);}
1547    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1548    static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
1549        {return __allocate(__a, __n, __hint,
1550            __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}
1551
1552    _LIBCPP_INLINE_VISIBILITY
1553    static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
1554        {__a.deallocate(__p, __n);}
1555
1556#ifndef _LIBCPP_HAS_NO_VARIADICS
1557    template <class _Tp, class... _Args>
1558        _LIBCPP_INLINE_VISIBILITY
1559        static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
1560            {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
1561                         __a, __p, _VSTD::forward<_Args>(__args)...);}
1562#else  // _LIBCPP_HAS_NO_VARIADICS
1563    template <class _Tp>
1564        _LIBCPP_INLINE_VISIBILITY
1565        static void construct(allocator_type&, _Tp* __p)
1566            {
1567                ::new ((void*)__p) _Tp();
1568            }
1569    template <class _Tp, class _A0>
1570        _LIBCPP_INLINE_VISIBILITY
1571        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0)
1572            {
1573                __construct(__has_construct<allocator_type, _Tp*, const _A0&>(),
1574                            __a, __p, __a0);
1575            }
1576    template <class _Tp, class _A0, class _A1>
1577        _LIBCPP_INLINE_VISIBILITY
1578        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
1579                              const _A1& __a1)
1580            {
1581                ::new ((void*)__p) _Tp(__a0, __a1);
1582            }
1583    template <class _Tp, class _A0, class _A1, class _A2>
1584        _LIBCPP_INLINE_VISIBILITY
1585        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
1586                              const _A1& __a1, const _A2& __a2)
1587            {
1588                ::new ((void*)__p) _Tp(__a0, __a1, __a2);
1589            }
1590#endif  // _LIBCPP_HAS_NO_VARIADICS
1591
1592    template <class _Tp>
1593        _LIBCPP_INLINE_VISIBILITY
1594        static void destroy(allocator_type& __a, _Tp* __p)
1595            {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}
1596
1597    _LIBCPP_INLINE_VISIBILITY
1598    static size_type max_size(const allocator_type& __a) _NOEXCEPT
1599        {return __max_size(__has_max_size<const allocator_type>(), __a);}
1600
1601    _LIBCPP_INLINE_VISIBILITY
1602    static allocator_type
1603        select_on_container_copy_construction(const allocator_type& __a)
1604            {return __select_on_container_copy_construction(
1605                __has_select_on_container_copy_construction<const allocator_type>(),
1606                __a);}
1607
1608    template <class _Ptr>
1609        _LIBCPP_INLINE_VISIBILITY
1610        static
1611        void
1612        __construct_forward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
1613        {
1614            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1615                construct(__a, _VSTD::__to_raw_pointer(__begin2), _VSTD::move_if_noexcept(*__begin1));
1616        }
1617
1618    template <class _Tp>
1619        _LIBCPP_INLINE_VISIBILITY
1620        static
1621        typename enable_if
1622        <
1623            (__is_default_allocator<allocator_type>::value
1624                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1625             is_trivially_move_constructible<_Tp>::value,
1626            void
1627        >::type
1628        __construct_forward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
1629        {
1630            ptrdiff_t _Np = __end1 - __begin1;
1631            if (_Np > 0)
1632            {
1633                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
1634                __begin2 += _Np;
1635            }
1636        }
1637
1638    template <class _Iter, class _Ptr>
1639        _LIBCPP_INLINE_VISIBILITY
1640        static
1641        void
1642        __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
1643        {
1644            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1645                construct(__a, _VSTD::__to_raw_pointer(__begin2), *__begin1);
1646        }
1647
1648    template <class _SourceTp, class _DestTp,
1649              class _RawSourceTp = typename remove_const<_SourceTp>::type,
1650              class _RawDestTp = typename remove_const<_DestTp>::type>
1651        _LIBCPP_INLINE_VISIBILITY
1652        static
1653        typename enable_if
1654        <
1655            is_trivially_move_constructible<_DestTp>::value &&
1656            is_same<_RawSourceTp, _RawDestTp>::value &&
1657            (__is_default_allocator<allocator_type>::value ||
1658             !__has_construct<allocator_type, _DestTp*, _SourceTp&>::value),
1659            void
1660        >::type
1661        __construct_range_forward(allocator_type&, _SourceTp* __begin1, _SourceTp* __end1, _DestTp*& __begin2)
1662        {
1663            ptrdiff_t _Np = __end1 - __begin1;
1664            if (_Np > 0)
1665            {
1666                _VSTD::memcpy(const_cast<_RawDestTp*>(__begin2), __begin1, _Np * sizeof(_DestTp));
1667                __begin2 += _Np;
1668            }
1669        }
1670
1671    template <class _Ptr>
1672        _LIBCPP_INLINE_VISIBILITY
1673        static
1674        void
1675        __construct_backward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
1676        {
1677            while (__end1 != __begin1)
1678            {
1679                construct(__a, _VSTD::__to_raw_pointer(__end2-1), _VSTD::move_if_noexcept(*--__end1));
1680                --__end2;
1681            }
1682        }
1683
1684    template <class _Tp>
1685        _LIBCPP_INLINE_VISIBILITY
1686        static
1687        typename enable_if
1688        <
1689            (__is_default_allocator<allocator_type>::value
1690                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1691             is_trivially_move_constructible<_Tp>::value,
1692            void
1693        >::type
1694        __construct_backward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
1695        {
1696            ptrdiff_t _Np = __end1 - __begin1;
1697            __end2 -= _Np;
1698            if (_Np > 0)
1699                _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
1700        }
1701
1702private:
1703
1704    _LIBCPP_INLINE_VISIBILITY
1705    static pointer __allocate(allocator_type& __a, size_type __n,
1706        const_void_pointer __hint, true_type)
1707        {return __a.allocate(__n, __hint);}
1708    _LIBCPP_INLINE_VISIBILITY
1709    static pointer __allocate(allocator_type& __a, size_type __n,
1710        const_void_pointer, false_type)
1711        {return __a.allocate(__n);}
1712
1713#ifndef _LIBCPP_HAS_NO_VARIADICS
1714    template <class _Tp, class... _Args>
1715        _LIBCPP_INLINE_VISIBILITY
1716        static void __construct(true_type, allocator_type& __a, _Tp* __p, _Args&&... __args)
1717            {__a.construct(__p, _VSTD::forward<_Args>(__args)...);}
1718    template <class _Tp, class... _Args>
1719        _LIBCPP_INLINE_VISIBILITY
1720        static void __construct(false_type, allocator_type&, _Tp* __p, _Args&&... __args)
1721            {
1722                ::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
1723            }
1724#else  // _LIBCPP_HAS_NO_VARIADICS
1725    template <class _Tp, class _A0>
1726        _LIBCPP_INLINE_VISIBILITY
1727        static void __construct(true_type, allocator_type& __a, _Tp* __p,
1728                                const _A0& __a0)
1729            {__a.construct(__p, __a0);}
1730    template <class _Tp, class _A0>
1731        _LIBCPP_INLINE_VISIBILITY
1732        static void __construct(false_type, allocator_type&, _Tp* __p,
1733                                const _A0& __a0)
1734            {
1735                ::new ((void*)__p) _Tp(__a0);
1736            }
1737#endif  // _LIBCPP_HAS_NO_VARIADICS
1738
1739    template <class _Tp>
1740        _LIBCPP_INLINE_VISIBILITY
1741        static void __destroy(true_type, allocator_type& __a, _Tp* __p)
1742            {__a.destroy(__p);}
1743    template <class _Tp>
1744        _LIBCPP_INLINE_VISIBILITY
1745        static void __destroy(false_type, allocator_type&, _Tp* __p)
1746            {
1747                __p->~_Tp();
1748            }
1749
1750    _LIBCPP_INLINE_VISIBILITY
1751    static size_type __max_size(true_type, const allocator_type& __a) _NOEXCEPT
1752            {return __a.max_size();}
1753    _LIBCPP_INLINE_VISIBILITY
1754    static size_type __max_size(false_type, const allocator_type&) _NOEXCEPT
1755            {return numeric_limits<size_type>::max() / sizeof(value_type);}
1756
1757    _LIBCPP_INLINE_VISIBILITY
1758    static allocator_type
1759        __select_on_container_copy_construction(true_type, const allocator_type& __a)
1760            {return __a.select_on_container_copy_construction();}
1761    _LIBCPP_INLINE_VISIBILITY
1762    static allocator_type
1763        __select_on_container_copy_construction(false_type, const allocator_type& __a)
1764            {return __a;}
1765};
1766
1767template <class _Traits, class _Tp>
1768struct __rebind_alloc_helper
1769{
1770#ifndef _LIBCPP_CXX03_LANG
1771    typedef typename _Traits::template rebind_alloc<_Tp>        type;
1772#else
1773    typedef typename _Traits::template rebind_alloc<_Tp>::other type;
1774#endif
1775};
1776
1777// allocator
1778
1779template <class _Tp>
1780class _LIBCPP_TEMPLATE_VIS allocator
1781{
1782public:
1783    typedef size_t            size_type;
1784    typedef ptrdiff_t         difference_type;
1785    typedef _Tp*              pointer;
1786    typedef const _Tp*        const_pointer;
1787    typedef _Tp&              reference;
1788    typedef const _Tp&        const_reference;
1789    typedef _Tp               value_type;
1790
1791    typedef true_type propagate_on_container_move_assignment;
1792    typedef true_type is_always_equal;
1793
1794    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1795
1796    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1797    allocator() _NOEXCEPT {}
1798
1799    template <class _Up>
1800    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1801    allocator(const allocator<_Up>&) _NOEXCEPT {}
1802
1803    _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
1804        {return _VSTD::addressof(__x);}
1805    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1806        {return _VSTD::addressof(__x);}
1807    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1808    pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1809        {
1810        if (__n > max_size())
1811            __throw_length_error("allocator<T>::allocate(size_t n)"
1812                                 " 'n' exceeds maximum supported size");
1813        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1814        }
1815    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
1816        {_VSTD::__libcpp_deallocate((void*)__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
1817    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1818        {return size_type(~0) / sizeof(_Tp);}
1819#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1820    template <class _Up, class... _Args>
1821        _LIBCPP_INLINE_VISIBILITY
1822        void
1823        construct(_Up* __p, _Args&&... __args)
1824        {
1825            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1826        }
1827#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1828        _LIBCPP_INLINE_VISIBILITY
1829        void
1830        construct(pointer __p)
1831        {
1832            ::new((void*)__p) _Tp();
1833        }
1834# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1835
1836    template <class _A0>
1837        _LIBCPP_INLINE_VISIBILITY
1838        void
1839        construct(pointer __p, _A0& __a0)
1840        {
1841            ::new((void*)__p) _Tp(__a0);
1842        }
1843    template <class _A0>
1844        _LIBCPP_INLINE_VISIBILITY
1845        void
1846        construct(pointer __p, const _A0& __a0)
1847        {
1848            ::new((void*)__p) _Tp(__a0);
1849        }
1850# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1851    template <class _A0, class _A1>
1852        _LIBCPP_INLINE_VISIBILITY
1853        void
1854        construct(pointer __p, _A0& __a0, _A1& __a1)
1855        {
1856            ::new((void*)__p) _Tp(__a0, __a1);
1857        }
1858    template <class _A0, class _A1>
1859        _LIBCPP_INLINE_VISIBILITY
1860        void
1861        construct(pointer __p, const _A0& __a0, _A1& __a1)
1862        {
1863            ::new((void*)__p) _Tp(__a0, __a1);
1864        }
1865    template <class _A0, class _A1>
1866        _LIBCPP_INLINE_VISIBILITY
1867        void
1868        construct(pointer __p, _A0& __a0, const _A1& __a1)
1869        {
1870            ::new((void*)__p) _Tp(__a0, __a1);
1871        }
1872    template <class _A0, class _A1>
1873        _LIBCPP_INLINE_VISIBILITY
1874        void
1875        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1876        {
1877            ::new((void*)__p) _Tp(__a0, __a1);
1878        }
1879#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1880    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1881};
1882
1883template <class _Tp>
1884class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
1885{
1886public:
1887    typedef size_t            size_type;
1888    typedef ptrdiff_t         difference_type;
1889    typedef const _Tp*        pointer;
1890    typedef const _Tp*        const_pointer;
1891    typedef const _Tp&        reference;
1892    typedef const _Tp&        const_reference;
1893    typedef const _Tp         value_type;
1894
1895    typedef true_type propagate_on_container_move_assignment;
1896    typedef true_type is_always_equal;
1897
1898    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1899
1900    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1901    allocator() _NOEXCEPT {}
1902
1903    template <class _Up>
1904    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1905    allocator(const allocator<_Up>&) _NOEXCEPT {}
1906
1907    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1908        {return _VSTD::addressof(__x);}
1909    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1910    {
1911        if (__n > max_size())
1912            __throw_length_error("allocator<const T>::allocate(size_t n)"
1913                                 " 'n' exceeds maximum supported size");
1914        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1915    }
1916    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
1917        {_VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
1918    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1919        {return size_type(~0) / sizeof(_Tp);}
1920#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1921    template <class _Up, class... _Args>
1922        _LIBCPP_INLINE_VISIBILITY
1923        void
1924        construct(_Up* __p, _Args&&... __args)
1925        {
1926            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1927        }
1928#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1929        _LIBCPP_INLINE_VISIBILITY
1930        void
1931        construct(pointer __p)
1932        {
1933            ::new((void*) const_cast<_Tp *>(__p)) _Tp();
1934        }
1935# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1936
1937    template <class _A0>
1938        _LIBCPP_INLINE_VISIBILITY
1939        void
1940        construct(pointer __p, _A0& __a0)
1941        {
1942            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
1943        }
1944    template <class _A0>
1945        _LIBCPP_INLINE_VISIBILITY
1946        void
1947        construct(pointer __p, const _A0& __a0)
1948        {
1949            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
1950        }
1951# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1952    template <class _A0, class _A1>
1953        _LIBCPP_INLINE_VISIBILITY
1954        void
1955        construct(pointer __p, _A0& __a0, _A1& __a1)
1956        {
1957            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1958        }
1959    template <class _A0, class _A1>
1960        _LIBCPP_INLINE_VISIBILITY
1961        void
1962        construct(pointer __p, const _A0& __a0, _A1& __a1)
1963        {
1964            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1965        }
1966    template <class _A0, class _A1>
1967        _LIBCPP_INLINE_VISIBILITY
1968        void
1969        construct(pointer __p, _A0& __a0, const _A1& __a1)
1970        {
1971            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1972        }
1973    template <class _A0, class _A1>
1974        _LIBCPP_INLINE_VISIBILITY
1975        void
1976        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1977        {
1978            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1979        }
1980#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1981    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1982};
1983
1984template <class _Tp, class _Up>
1985inline _LIBCPP_INLINE_VISIBILITY
1986bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
1987
1988template <class _Tp, class _Up>
1989inline _LIBCPP_INLINE_VISIBILITY
1990bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
1991
1992template <class _OutputIterator, class _Tp>
1993class _LIBCPP_TEMPLATE_VIS raw_storage_iterator
1994    : public iterator<output_iterator_tag,
1995                      _Tp,                                         // purposefully not C++03
1996                      ptrdiff_t,                                   // purposefully not C++03
1997                      _Tp*,                                        // purposefully not C++03
1998                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
1999{
2000private:
2001    _OutputIterator __x_;
2002public:
2003    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
2004    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
2005    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
2006        {::new(_VSTD::addressof(*__x_)) _Tp(__element); return *this;}
2007#if _LIBCPP_STD_VER >= 14
2008    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
2009        {::new(_VSTD::addressof(*__x_)) _Tp(_VSTD::move(__element)); return *this;}
2010#endif
2011    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
2012    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
2013        {raw_storage_iterator __t(*this); ++__x_; return __t;}
2014#if _LIBCPP_STD_VER >= 14
2015    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
2016#endif
2017};
2018
2019template <class _Tp>
2020_LIBCPP_NODISCARD_EXT _LIBCPP_NO_CFI
2021pair<_Tp*, ptrdiff_t>
2022get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
2023{
2024    pair<_Tp*, ptrdiff_t> __r(0, 0);
2025    const ptrdiff_t __m = (~ptrdiff_t(0) ^
2026                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
2027                           / sizeof(_Tp);
2028    if (__n > __m)
2029        __n = __m;
2030    while (__n > 0)
2031    {
2032#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
2033    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
2034        {
2035            std::align_val_t __al =
2036                std::align_val_t(std::alignment_of<_Tp>::value);
2037            __r.first = static_cast<_Tp*>(::operator new(
2038                __n * sizeof(_Tp), __al, nothrow));
2039        } else {
2040            __r.first = static_cast<_Tp*>(::operator new(
2041                __n * sizeof(_Tp), nothrow));
2042        }
2043#else
2044    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
2045        {
2046            // Since aligned operator new is unavailable, return an empty
2047            // buffer rather than one with invalid alignment.
2048            return __r;
2049        }
2050
2051        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
2052#endif
2053
2054        if (__r.first)
2055        {
2056            __r.second = __n;
2057            break;
2058        }
2059        __n /= 2;
2060    }
2061    return __r;
2062}
2063
2064template <class _Tp>
2065inline _LIBCPP_INLINE_VISIBILITY
2066void return_temporary_buffer(_Tp* __p) _NOEXCEPT
2067{
2068  _VSTD::__libcpp_deallocate_unsized((void*)__p, _LIBCPP_ALIGNOF(_Tp));
2069}
2070
2071#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2072template <class _Tp>
2073struct _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr_ref
2074{
2075    _Tp* __ptr_;
2076};
2077
2078template<class _Tp>
2079class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr
2080{
2081private:
2082    _Tp* __ptr_;
2083public:
2084    typedef _Tp element_type;
2085
2086    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) throw() : __ptr_(__p) {}
2087    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) throw() : __ptr_(__p.release()) {}
2088    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) throw()
2089        : __ptr_(__p.release()) {}
2090    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) throw()
2091        {reset(__p.release()); return *this;}
2092    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) throw()
2093        {reset(__p.release()); return *this;}
2094    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) throw()
2095        {reset(__p.__ptr_); return *this;}
2096    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() throw() {delete __ptr_;}
2097
2098    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const throw()
2099        {return *__ptr_;}
2100    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const throw() {return __ptr_;}
2101    _LIBCPP_INLINE_VISIBILITY _Tp* get() const throw() {return __ptr_;}
2102    _LIBCPP_INLINE_VISIBILITY _Tp* release() throw()
2103    {
2104        _Tp* __t = __ptr_;
2105        __ptr_ = 0;
2106        return __t;
2107    }
2108    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) throw()
2109    {
2110        if (__ptr_ != __p)
2111            delete __ptr_;
2112        __ptr_ = __p;
2113    }
2114
2115    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) throw() : __ptr_(__p.__ptr_) {}
2116    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() throw()
2117        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
2118    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() throw()
2119        {return auto_ptr<_Up>(release());}
2120};
2121
2122template <>
2123class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr<void>
2124{
2125public:
2126    typedef void element_type;
2127};
2128#endif
2129
2130template <class _Tp, int _Idx,
2131          bool _CanBeEmptyBase =
2132              is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value>
2133struct __compressed_pair_elem {
2134  typedef _Tp _ParamT;
2135  typedef _Tp& reference;
2136  typedef const _Tp& const_reference;
2137
2138#ifndef _LIBCPP_CXX03_LANG
2139  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() : __value_() {}
2140
2141  template <class _Up, class = typename enable_if<
2142      !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2143  >::type>
2144  _LIBCPP_INLINE_VISIBILITY
2145  constexpr explicit
2146  __compressed_pair_elem(_Up&& __u)
2147      : __value_(_VSTD::forward<_Up>(__u))
2148    {
2149    }
2150
2151  template <class... _Args, size_t... _Indexes>
2152  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2153  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2154                         __tuple_indices<_Indexes...>)
2155      : __value_(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2156#else
2157  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_() {}
2158  _LIBCPP_INLINE_VISIBILITY
2159  __compressed_pair_elem(_ParamT __p) : __value_(std::forward<_ParamT>(__p)) {}
2160#endif
2161
2162  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return __value_; }
2163  _LIBCPP_INLINE_VISIBILITY
2164  const_reference __get() const _NOEXCEPT { return __value_; }
2165
2166private:
2167  _Tp __value_;
2168};
2169
2170template <class _Tp, int _Idx>
2171struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp {
2172  typedef _Tp _ParamT;
2173  typedef _Tp& reference;
2174  typedef const _Tp& const_reference;
2175  typedef _Tp __value_type;
2176
2177#ifndef _LIBCPP_CXX03_LANG
2178  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() = default;
2179
2180  template <class _Up, class = typename enable_if<
2181        !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2182  >::type>
2183  _LIBCPP_INLINE_VISIBILITY
2184  constexpr explicit
2185  __compressed_pair_elem(_Up&& __u)
2186      : __value_type(_VSTD::forward<_Up>(__u))
2187  {}
2188
2189  template <class... _Args, size_t... _Indexes>
2190  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2191  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2192                         __tuple_indices<_Indexes...>)
2193      : __value_type(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2194#else
2195  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_type() {}
2196  _LIBCPP_INLINE_VISIBILITY
2197  __compressed_pair_elem(_ParamT __p)
2198      : __value_type(std::forward<_ParamT>(__p)) {}
2199#endif
2200
2201  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return *this; }
2202  _LIBCPP_INLINE_VISIBILITY
2203  const_reference __get() const _NOEXCEPT { return *this; }
2204};
2205
2206// Tag used to construct the second element of the compressed pair.
2207struct __second_tag {};
2208
2209template <class _T1, class _T2>
2210class __compressed_pair : private __compressed_pair_elem<_T1, 0>,
2211                          private __compressed_pair_elem<_T2, 1> {
2212  typedef __compressed_pair_elem<_T1, 0> _Base1;
2213  typedef __compressed_pair_elem<_T2, 1> _Base2;
2214
2215  // NOTE: This static assert should never fire because __compressed_pair
2216  // is *almost never* used in a scenario where it's possible for T1 == T2.
2217  // (The exception is std::function where it is possible that the function
2218  //  object and the allocator have the same type).
2219  static_assert((!is_same<_T1, _T2>::value),
2220    "__compressed_pair cannot be instantated when T1 and T2 are the same type; "
2221    "The current implementation is NOT ABI-compatible with the previous "
2222    "implementation for this configuration");
2223
2224public:
2225#ifndef _LIBCPP_CXX03_LANG
2226  template <bool _Dummy = true,
2227      class = typename enable_if<
2228          __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
2229          __dependent_type<is_default_constructible<_T2>, _Dummy>::value
2230      >::type
2231  >
2232  _LIBCPP_INLINE_VISIBILITY
2233  constexpr __compressed_pair() {}
2234
2235  template <class _Tp, typename enable_if<!is_same<typename decay<_Tp>::type,
2236                                                   __compressed_pair>::value,
2237                                          bool>::type = true>
2238  _LIBCPP_INLINE_VISIBILITY constexpr explicit
2239  __compressed_pair(_Tp&& __t)
2240      : _Base1(std::forward<_Tp>(__t)), _Base2() {}
2241
2242  template <class _Tp>
2243  _LIBCPP_INLINE_VISIBILITY constexpr
2244  __compressed_pair(__second_tag, _Tp&& __t)
2245      : _Base1(), _Base2(std::forward<_Tp>(__t)) {}
2246
2247  template <class _U1, class _U2>
2248  _LIBCPP_INLINE_VISIBILITY constexpr
2249  __compressed_pair(_U1&& __t1, _U2&& __t2)
2250      : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {}
2251
2252  template <class... _Args1, class... _Args2>
2253  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2254  __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
2255                    tuple<_Args2...> __second_args)
2256      : _Base1(__pc, _VSTD::move(__first_args),
2257               typename __make_tuple_indices<sizeof...(_Args1)>::type()),
2258        _Base2(__pc, _VSTD::move(__second_args),
2259               typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}
2260
2261#else
2262  _LIBCPP_INLINE_VISIBILITY
2263  __compressed_pair() {}
2264
2265  _LIBCPP_INLINE_VISIBILITY explicit
2266  __compressed_pair(_T1 __t1) : _Base1(_VSTD::forward<_T1>(__t1)) {}
2267
2268  _LIBCPP_INLINE_VISIBILITY
2269  __compressed_pair(__second_tag, _T2 __t2)
2270      : _Base1(), _Base2(_VSTD::forward<_T2>(__t2)) {}
2271
2272  _LIBCPP_INLINE_VISIBILITY
2273  __compressed_pair(_T1 __t1, _T2 __t2)
2274      : _Base1(_VSTD::forward<_T1>(__t1)), _Base2(_VSTD::forward<_T2>(__t2)) {}
2275#endif
2276
2277  _LIBCPP_INLINE_VISIBILITY
2278  typename _Base1::reference first() _NOEXCEPT {
2279    return static_cast<_Base1&>(*this).__get();
2280  }
2281
2282  _LIBCPP_INLINE_VISIBILITY
2283  typename _Base1::const_reference first() const _NOEXCEPT {
2284    return static_cast<_Base1 const&>(*this).__get();
2285  }
2286
2287  _LIBCPP_INLINE_VISIBILITY
2288  typename _Base2::reference second() _NOEXCEPT {
2289    return static_cast<_Base2&>(*this).__get();
2290  }
2291
2292  _LIBCPP_INLINE_VISIBILITY
2293  typename _Base2::const_reference second() const _NOEXCEPT {
2294    return static_cast<_Base2 const&>(*this).__get();
2295  }
2296
2297  _LIBCPP_INLINE_VISIBILITY
2298  void swap(__compressed_pair& __x)
2299    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2300               __is_nothrow_swappable<_T2>::value)
2301  {
2302    using std::swap;
2303    swap(first(), __x.first());
2304    swap(second(), __x.second());
2305  }
2306};
2307
2308template <class _T1, class _T2>
2309inline _LIBCPP_INLINE_VISIBILITY
2310void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
2311    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2312               __is_nothrow_swappable<_T2>::value) {
2313  __x.swap(__y);
2314}
2315
2316// default_delete
2317
2318template <class _Tp>
2319struct _LIBCPP_TEMPLATE_VIS default_delete {
2320    static_assert(!is_function<_Tp>::value,
2321                  "default_delete cannot be instantiated for function types");
2322#ifndef _LIBCPP_CXX03_LANG
2323  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() noexcept = default;
2324#else
2325  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2326#endif
2327  template <class _Up>
2328  _LIBCPP_INLINE_VISIBILITY
2329  default_delete(const default_delete<_Up>&,
2330                 typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* =
2331                     0) _NOEXCEPT {}
2332
2333  _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __ptr) const _NOEXCEPT {
2334    static_assert(sizeof(_Tp) > 0,
2335                  "default_delete can not delete incomplete type");
2336    static_assert(!is_void<_Tp>::value,
2337                  "default_delete can not delete incomplete type");
2338    delete __ptr;
2339  }
2340};
2341
2342template <class _Tp>
2343struct _LIBCPP_TEMPLATE_VIS default_delete<_Tp[]> {
2344private:
2345  template <class _Up>
2346  struct _EnableIfConvertible
2347      : enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value> {};
2348
2349public:
2350#ifndef _LIBCPP_CXX03_LANG
2351  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() noexcept = default;
2352#else
2353  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2354#endif
2355
2356  template <class _Up>
2357  _LIBCPP_INLINE_VISIBILITY
2358  default_delete(const default_delete<_Up[]>&,
2359                 typename _EnableIfConvertible<_Up>::type* = 0) _NOEXCEPT {}
2360
2361  template <class _Up>
2362  _LIBCPP_INLINE_VISIBILITY
2363  typename _EnableIfConvertible<_Up>::type
2364  operator()(_Up* __ptr) const _NOEXCEPT {
2365    static_assert(sizeof(_Tp) > 0,
2366                  "default_delete can not delete incomplete type");
2367    static_assert(!is_void<_Tp>::value,
2368                  "default_delete can not delete void type");
2369    delete[] __ptr;
2370  }
2371};
2372
2373
2374
2375#ifndef _LIBCPP_CXX03_LANG
2376template <class _Deleter>
2377struct __unique_ptr_deleter_sfinae {
2378  static_assert(!is_reference<_Deleter>::value, "incorrect specialization");
2379  typedef const _Deleter& __lval_ref_type;
2380  typedef _Deleter&& __good_rval_ref_type;
2381  typedef true_type __enable_rval_overload;
2382};
2383
2384template <class _Deleter>
2385struct __unique_ptr_deleter_sfinae<_Deleter const&> {
2386  typedef const _Deleter& __lval_ref_type;
2387  typedef const _Deleter&& __bad_rval_ref_type;
2388  typedef false_type __enable_rval_overload;
2389};
2390
2391template <class _Deleter>
2392struct __unique_ptr_deleter_sfinae<_Deleter&> {
2393  typedef _Deleter& __lval_ref_type;
2394  typedef _Deleter&& __bad_rval_ref_type;
2395  typedef false_type __enable_rval_overload;
2396};
2397#endif // !defined(_LIBCPP_CXX03_LANG)
2398
2399template <class _Tp, class _Dp = default_delete<_Tp> >
2400class _LIBCPP_TEMPLATE_VIS unique_ptr {
2401public:
2402  typedef _Tp element_type;
2403  typedef _Dp deleter_type;
2404  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2405
2406  static_assert(!is_rvalue_reference<deleter_type>::value,
2407                "the specified deleter type cannot be an rvalue reference");
2408
2409private:
2410  __compressed_pair<pointer, deleter_type> __ptr_;
2411
2412  struct __nat { int __for_bool_; };
2413
2414#ifndef _LIBCPP_CXX03_LANG
2415  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2416
2417  template <bool _Dummy>
2418  using _LValRefType =
2419      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2420
2421  template <bool _Dummy>
2422  using _GoodRValRefType =
2423      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2424
2425  template <bool _Dummy>
2426  using _BadRValRefType =
2427      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2428
2429  template <bool _Dummy, class _Deleter = typename __dependent_type<
2430                             __identity<deleter_type>, _Dummy>::type>
2431  using _EnableIfDeleterDefaultConstructible =
2432      typename enable_if<is_default_constructible<_Deleter>::value &&
2433                         !is_pointer<_Deleter>::value>::type;
2434
2435  template <class _ArgType>
2436  using _EnableIfDeleterConstructible =
2437      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2438
2439  template <class _UPtr, class _Up>
2440  using _EnableIfMoveConvertible = typename enable_if<
2441      is_convertible<typename _UPtr::pointer, pointer>::value &&
2442      !is_array<_Up>::value
2443  >::type;
2444
2445  template <class _UDel>
2446  using _EnableIfDeleterConvertible = typename enable_if<
2447      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2448      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2449    >::type;
2450
2451  template <class _UDel>
2452  using _EnableIfDeleterAssignable = typename enable_if<
2453      is_assignable<_Dp&, _UDel&&>::value
2454    >::type;
2455
2456public:
2457  template <bool _Dummy = true,
2458            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2459  _LIBCPP_INLINE_VISIBILITY
2460  constexpr unique_ptr() noexcept : __ptr_(pointer()) {}
2461
2462  template <bool _Dummy = true,
2463            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2464  _LIBCPP_INLINE_VISIBILITY
2465  constexpr unique_ptr(nullptr_t) noexcept : __ptr_(pointer()) {}
2466
2467  template <bool _Dummy = true,
2468            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2469  _LIBCPP_INLINE_VISIBILITY
2470  explicit unique_ptr(pointer __p) noexcept : __ptr_(__p) {}
2471
2472  template <bool _Dummy = true,
2473            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>>
2474  _LIBCPP_INLINE_VISIBILITY
2475  unique_ptr(pointer __p, _LValRefType<_Dummy> __d) noexcept
2476      : __ptr_(__p, __d) {}
2477
2478  template <bool _Dummy = true,
2479            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>>
2480  _LIBCPP_INLINE_VISIBILITY
2481  unique_ptr(pointer __p, _GoodRValRefType<_Dummy> __d) noexcept
2482      : __ptr_(__p, _VSTD::move(__d)) {
2483    static_assert(!is_reference<deleter_type>::value,
2484                  "rvalue deleter bound to reference");
2485  }
2486
2487  template <bool _Dummy = true,
2488            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy>>>
2489  _LIBCPP_INLINE_VISIBILITY
2490  unique_ptr(pointer __p, _BadRValRefType<_Dummy> __d) = delete;
2491
2492  _LIBCPP_INLINE_VISIBILITY
2493  unique_ptr(unique_ptr&& __u) noexcept
2494      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2495  }
2496
2497  template <class _Up, class _Ep,
2498      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2499      class = _EnableIfDeleterConvertible<_Ep>
2500  >
2501  _LIBCPP_INLINE_VISIBILITY
2502  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2503      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
2504
2505#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2506  template <class _Up>
2507  _LIBCPP_INLINE_VISIBILITY
2508  unique_ptr(auto_ptr<_Up>&& __p,
2509             typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2510                                    is_same<_Dp, default_delete<_Tp>>::value,
2511                                __nat>::type = __nat()) _NOEXCEPT
2512      : __ptr_(__p.release()) {}
2513#endif
2514
2515  _LIBCPP_INLINE_VISIBILITY
2516  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2517    reset(__u.release());
2518    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2519    return *this;
2520  }
2521
2522  template <class _Up, class _Ep,
2523      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2524      class = _EnableIfDeleterAssignable<_Ep>
2525  >
2526  _LIBCPP_INLINE_VISIBILITY
2527  unique_ptr& operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2528    reset(__u.release());
2529    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2530    return *this;
2531  }
2532
2533#else  // _LIBCPP_CXX03_LANG
2534private:
2535  unique_ptr(unique_ptr&);
2536  template <class _Up, class _Ep> unique_ptr(unique_ptr<_Up, _Ep>&);
2537
2538  unique_ptr& operator=(unique_ptr&);
2539  template <class _Up, class _Ep> unique_ptr& operator=(unique_ptr<_Up, _Ep>&);
2540
2541public:
2542  _LIBCPP_INLINE_VISIBILITY
2543  unique_ptr() : __ptr_(pointer())
2544  {
2545    static_assert(!is_pointer<deleter_type>::value,
2546                  "unique_ptr constructed with null function pointer deleter");
2547    static_assert(is_default_constructible<deleter_type>::value,
2548                  "unique_ptr::deleter_type is not default constructible");
2549  }
2550  _LIBCPP_INLINE_VISIBILITY
2551  unique_ptr(nullptr_t) : __ptr_(pointer())
2552  {
2553    static_assert(!is_pointer<deleter_type>::value,
2554                  "unique_ptr constructed with null function pointer deleter");
2555  }
2556  _LIBCPP_INLINE_VISIBILITY
2557  explicit unique_ptr(pointer __p)
2558      : __ptr_(_VSTD::move(__p)) {
2559    static_assert(!is_pointer<deleter_type>::value,
2560                  "unique_ptr constructed with null function pointer deleter");
2561  }
2562
2563  _LIBCPP_INLINE_VISIBILITY
2564  operator __rv<unique_ptr>() {
2565    return __rv<unique_ptr>(*this);
2566  }
2567
2568  _LIBCPP_INLINE_VISIBILITY
2569  unique_ptr(__rv<unique_ptr> __u)
2570      : __ptr_(__u->release(),
2571               _VSTD::forward<deleter_type>(__u->get_deleter())) {}
2572
2573  template <class _Up, class _Ep>
2574  _LIBCPP_INLINE_VISIBILITY
2575  typename enable_if<
2576      !is_array<_Up>::value &&
2577          is_convertible<typename unique_ptr<_Up, _Ep>::pointer,
2578                         pointer>::value &&
2579          is_assignable<deleter_type&, _Ep&>::value,
2580      unique_ptr&>::type
2581  operator=(unique_ptr<_Up, _Ep> __u) {
2582    reset(__u.release());
2583    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2584    return *this;
2585  }
2586
2587  _LIBCPP_INLINE_VISIBILITY
2588  unique_ptr(pointer __p, deleter_type __d)
2589      : __ptr_(_VSTD::move(__p), _VSTD::move(__d)) {}
2590#endif // _LIBCPP_CXX03_LANG
2591
2592#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2593  template <class _Up>
2594  _LIBCPP_INLINE_VISIBILITY
2595      typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2596                             is_same<_Dp, default_delete<_Tp> >::value,
2597                         unique_ptr&>::type
2598      operator=(auto_ptr<_Up> __p) {
2599    reset(__p.release());
2600    return *this;
2601  }
2602#endif
2603
2604  _LIBCPP_INLINE_VISIBILITY
2605  ~unique_ptr() { reset(); }
2606
2607  _LIBCPP_INLINE_VISIBILITY
2608  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2609    reset();
2610    return *this;
2611  }
2612
2613  _LIBCPP_INLINE_VISIBILITY
2614  typename add_lvalue_reference<_Tp>::type
2615  operator*() const {
2616    return *__ptr_.first();
2617  }
2618  _LIBCPP_INLINE_VISIBILITY
2619  pointer operator->() const _NOEXCEPT {
2620    return __ptr_.first();
2621  }
2622  _LIBCPP_INLINE_VISIBILITY
2623  pointer get() const _NOEXCEPT {
2624    return __ptr_.first();
2625  }
2626  _LIBCPP_INLINE_VISIBILITY
2627  deleter_type& get_deleter() _NOEXCEPT {
2628    return __ptr_.second();
2629  }
2630  _LIBCPP_INLINE_VISIBILITY
2631  const deleter_type& get_deleter() const _NOEXCEPT {
2632    return __ptr_.second();
2633  }
2634  _LIBCPP_INLINE_VISIBILITY
2635  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2636    return __ptr_.first() != nullptr;
2637  }
2638
2639  _LIBCPP_INLINE_VISIBILITY
2640  pointer release() _NOEXCEPT {
2641    pointer __t = __ptr_.first();
2642    __ptr_.first() = pointer();
2643    return __t;
2644  }
2645
2646  _LIBCPP_INLINE_VISIBILITY
2647  void reset(pointer __p = pointer()) _NOEXCEPT {
2648    pointer __tmp = __ptr_.first();
2649    __ptr_.first() = __p;
2650    if (__tmp)
2651      __ptr_.second()(__tmp);
2652  }
2653
2654  _LIBCPP_INLINE_VISIBILITY
2655  void swap(unique_ptr& __u) _NOEXCEPT {
2656    __ptr_.swap(__u.__ptr_);
2657  }
2658};
2659
2660
2661template <class _Tp, class _Dp>
2662class _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
2663public:
2664  typedef _Tp element_type;
2665  typedef _Dp deleter_type;
2666  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2667
2668private:
2669  __compressed_pair<pointer, deleter_type> __ptr_;
2670
2671  template <class _From>
2672  struct _CheckArrayPointerConversion : is_same<_From, pointer> {};
2673
2674  template <class _FromElem>
2675  struct _CheckArrayPointerConversion<_FromElem*>
2676      : integral_constant<bool,
2677          is_same<_FromElem*, pointer>::value ||
2678            (is_same<pointer, element_type*>::value &&
2679             is_convertible<_FromElem(*)[], element_type(*)[]>::value)
2680      >
2681  {};
2682
2683#ifndef _LIBCPP_CXX03_LANG
2684  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2685
2686  template <bool _Dummy>
2687  using _LValRefType =
2688      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2689
2690  template <bool _Dummy>
2691  using _GoodRValRefType =
2692      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2693
2694  template <bool _Dummy>
2695  using _BadRValRefType =
2696      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2697
2698  template <bool _Dummy, class _Deleter = typename __dependent_type<
2699                             __identity<deleter_type>, _Dummy>::type>
2700  using _EnableIfDeleterDefaultConstructible =
2701      typename enable_if<is_default_constructible<_Deleter>::value &&
2702                         !is_pointer<_Deleter>::value>::type;
2703
2704  template <class _ArgType>
2705  using _EnableIfDeleterConstructible =
2706      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2707
2708  template <class _Pp>
2709  using _EnableIfPointerConvertible = typename enable_if<
2710      _CheckArrayPointerConversion<_Pp>::value
2711  >::type;
2712
2713  template <class _UPtr, class _Up,
2714        class _ElemT = typename _UPtr::element_type>
2715  using _EnableIfMoveConvertible = typename enable_if<
2716      is_array<_Up>::value &&
2717      is_same<pointer, element_type*>::value &&
2718      is_same<typename _UPtr::pointer, _ElemT*>::value &&
2719      is_convertible<_ElemT(*)[], element_type(*)[]>::value
2720    >::type;
2721
2722  template <class _UDel>
2723  using _EnableIfDeleterConvertible = typename enable_if<
2724      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2725      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2726    >::type;
2727
2728  template <class _UDel>
2729  using _EnableIfDeleterAssignable = typename enable_if<
2730      is_assignable<_Dp&, _UDel&&>::value
2731    >::type;
2732
2733public:
2734  template <bool _Dummy = true,
2735            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2736  _LIBCPP_INLINE_VISIBILITY
2737  constexpr unique_ptr() noexcept : __ptr_(pointer()) {}
2738
2739  template <bool _Dummy = true,
2740            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2741  _LIBCPP_INLINE_VISIBILITY
2742  constexpr unique_ptr(nullptr_t) noexcept : __ptr_(pointer()) {}
2743
2744  template <class _Pp, bool _Dummy = true,
2745            class = _EnableIfDeleterDefaultConstructible<_Dummy>,
2746            class = _EnableIfPointerConvertible<_Pp>>
2747  _LIBCPP_INLINE_VISIBILITY
2748  explicit unique_ptr(_Pp __p) noexcept
2749      : __ptr_(__p) {}
2750
2751  template <class _Pp, bool _Dummy = true,
2752            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>,
2753            class = _EnableIfPointerConvertible<_Pp>>
2754  _LIBCPP_INLINE_VISIBILITY
2755  unique_ptr(_Pp __p, _LValRefType<_Dummy> __d) noexcept
2756      : __ptr_(__p, __d) {}
2757
2758  template <bool _Dummy = true,
2759            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>>
2760  _LIBCPP_INLINE_VISIBILITY
2761  unique_ptr(nullptr_t, _LValRefType<_Dummy> __d) noexcept
2762      : __ptr_(nullptr, __d) {}
2763
2764  template <class _Pp, bool _Dummy = true,
2765            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>,
2766            class = _EnableIfPointerConvertible<_Pp>>
2767  _LIBCPP_INLINE_VISIBILITY
2768  unique_ptr(_Pp __p, _GoodRValRefType<_Dummy> __d) noexcept
2769      : __ptr_(__p, _VSTD::move(__d)) {
2770    static_assert(!is_reference<deleter_type>::value,
2771                  "rvalue deleter bound to reference");
2772  }
2773
2774  template <bool _Dummy = true,
2775            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>>
2776  _LIBCPP_INLINE_VISIBILITY
2777  unique_ptr(nullptr_t, _GoodRValRefType<_Dummy> __d) noexcept
2778      : __ptr_(nullptr, _VSTD::move(__d)) {
2779    static_assert(!is_reference<deleter_type>::value,
2780                  "rvalue deleter bound to reference");
2781  }
2782
2783  template <class _Pp, bool _Dummy = true,
2784            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy>>,
2785            class = _EnableIfPointerConvertible<_Pp>>
2786  _LIBCPP_INLINE_VISIBILITY
2787  unique_ptr(_Pp __p, _BadRValRefType<_Dummy> __d) = delete;
2788
2789  _LIBCPP_INLINE_VISIBILITY
2790  unique_ptr(unique_ptr&& __u) noexcept
2791      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2792  }
2793
2794  _LIBCPP_INLINE_VISIBILITY
2795  unique_ptr& operator=(unique_ptr&& __u) noexcept {
2796    reset(__u.release());
2797    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2798    return *this;
2799  }
2800
2801  template <class _Up, class _Ep,
2802      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2803      class = _EnableIfDeleterConvertible<_Ep>
2804  >
2805  _LIBCPP_INLINE_VISIBILITY
2806  unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
2807      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {
2808  }
2809
2810  template <class _Up, class _Ep,
2811      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2812      class = _EnableIfDeleterAssignable<_Ep>
2813  >
2814  _LIBCPP_INLINE_VISIBILITY
2815  unique_ptr&
2816  operator=(unique_ptr<_Up, _Ep>&& __u) noexcept {
2817    reset(__u.release());
2818    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2819    return *this;
2820  }
2821
2822#else // _LIBCPP_CXX03_LANG
2823private:
2824  template <class _Up> explicit unique_ptr(_Up);
2825
2826  unique_ptr(unique_ptr&);
2827  template <class _Up> unique_ptr(unique_ptr<_Up>&);
2828
2829  unique_ptr& operator=(unique_ptr&);
2830  template <class _Up> unique_ptr& operator=(unique_ptr<_Up>&);
2831
2832  template <class _Up>
2833  unique_ptr(_Up __u,
2834             typename conditional<
2835                 is_reference<deleter_type>::value, deleter_type,
2836                 typename add_lvalue_reference<const deleter_type>::type>::type,
2837             typename enable_if<is_convertible<_Up, pointer>::value,
2838                                __nat>::type = __nat());
2839public:
2840  _LIBCPP_INLINE_VISIBILITY
2841  unique_ptr() : __ptr_(pointer()) {
2842    static_assert(!is_pointer<deleter_type>::value,
2843                  "unique_ptr constructed with null function pointer deleter");
2844  }
2845  _LIBCPP_INLINE_VISIBILITY
2846  unique_ptr(nullptr_t) : __ptr_(pointer()) {
2847    static_assert(!is_pointer<deleter_type>::value,
2848                  "unique_ptr constructed with null function pointer deleter");
2849  }
2850
2851  _LIBCPP_INLINE_VISIBILITY
2852  explicit unique_ptr(pointer __p) : __ptr_(__p) {
2853    static_assert(!is_pointer<deleter_type>::value,
2854                  "unique_ptr constructed with null function pointer deleter");
2855  }
2856
2857  _LIBCPP_INLINE_VISIBILITY
2858  unique_ptr(pointer __p, deleter_type __d)
2859      : __ptr_(__p, _VSTD::forward<deleter_type>(__d)) {}
2860
2861  _LIBCPP_INLINE_VISIBILITY
2862  unique_ptr(nullptr_t, deleter_type __d)
2863      : __ptr_(pointer(), _VSTD::forward<deleter_type>(__d)) {}
2864
2865  _LIBCPP_INLINE_VISIBILITY
2866  operator __rv<unique_ptr>() {
2867    return __rv<unique_ptr>(*this);
2868  }
2869
2870  _LIBCPP_INLINE_VISIBILITY
2871  unique_ptr(__rv<unique_ptr> __u)
2872      : __ptr_(__u->release(),
2873               _VSTD::forward<deleter_type>(__u->get_deleter())) {}
2874
2875  _LIBCPP_INLINE_VISIBILITY
2876  unique_ptr& operator=(__rv<unique_ptr> __u) {
2877    reset(__u->release());
2878    __ptr_.second() = _VSTD::forward<deleter_type>(__u->get_deleter());
2879    return *this;
2880  }
2881
2882#endif // _LIBCPP_CXX03_LANG
2883
2884public:
2885  _LIBCPP_INLINE_VISIBILITY
2886  ~unique_ptr() { reset(); }
2887
2888  _LIBCPP_INLINE_VISIBILITY
2889  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2890    reset();
2891    return *this;
2892  }
2893
2894  _LIBCPP_INLINE_VISIBILITY
2895  typename add_lvalue_reference<_Tp>::type
2896  operator[](size_t __i) const {
2897    return __ptr_.first()[__i];
2898  }
2899  _LIBCPP_INLINE_VISIBILITY
2900  pointer get() const _NOEXCEPT {
2901    return __ptr_.first();
2902  }
2903
2904  _LIBCPP_INLINE_VISIBILITY
2905  deleter_type& get_deleter() _NOEXCEPT {
2906    return __ptr_.second();
2907  }
2908
2909  _LIBCPP_INLINE_VISIBILITY
2910  const deleter_type& get_deleter() const _NOEXCEPT {
2911    return __ptr_.second();
2912  }
2913  _LIBCPP_INLINE_VISIBILITY
2914  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2915    return __ptr_.first() != nullptr;
2916  }
2917
2918  _LIBCPP_INLINE_VISIBILITY
2919  pointer release() _NOEXCEPT {
2920    pointer __t = __ptr_.first();
2921    __ptr_.first() = pointer();
2922    return __t;
2923  }
2924
2925  template <class _Pp>
2926  _LIBCPP_INLINE_VISIBILITY
2927  typename enable_if<
2928      _CheckArrayPointerConversion<_Pp>::value
2929  >::type
2930  reset(_Pp __p) _NOEXCEPT {
2931    pointer __tmp = __ptr_.first();
2932    __ptr_.first() = __p;
2933    if (__tmp)
2934      __ptr_.second()(__tmp);
2935  }
2936
2937  _LIBCPP_INLINE_VISIBILITY
2938  void reset(nullptr_t = nullptr) _NOEXCEPT {
2939    pointer __tmp = __ptr_.first();
2940    __ptr_.first() = nullptr;
2941    if (__tmp)
2942      __ptr_.second()(__tmp);
2943  }
2944
2945  _LIBCPP_INLINE_VISIBILITY
2946  void swap(unique_ptr& __u) _NOEXCEPT {
2947    __ptr_.swap(__u.__ptr_);
2948  }
2949
2950};
2951
2952template <class _Tp, class _Dp>
2953inline _LIBCPP_INLINE_VISIBILITY
2954typename enable_if<
2955    __is_swappable<_Dp>::value,
2956    void
2957>::type
2958swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
2959
2960template <class _T1, class _D1, class _T2, class _D2>
2961inline _LIBCPP_INLINE_VISIBILITY
2962bool
2963operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
2964
2965template <class _T1, class _D1, class _T2, class _D2>
2966inline _LIBCPP_INLINE_VISIBILITY
2967bool
2968operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
2969
2970template <class _T1, class _D1, class _T2, class _D2>
2971inline _LIBCPP_INLINE_VISIBILITY
2972bool
2973operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
2974{
2975    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2976    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
2977    typedef typename common_type<_P1, _P2>::type _Vp;
2978    return less<_Vp>()(__x.get(), __y.get());
2979}
2980
2981template <class _T1, class _D1, class _T2, class _D2>
2982inline _LIBCPP_INLINE_VISIBILITY
2983bool
2984operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
2985
2986template <class _T1, class _D1, class _T2, class _D2>
2987inline _LIBCPP_INLINE_VISIBILITY
2988bool
2989operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
2990
2991template <class _T1, class _D1, class _T2, class _D2>
2992inline _LIBCPP_INLINE_VISIBILITY
2993bool
2994operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
2995
2996template <class _T1, class _D1>
2997inline _LIBCPP_INLINE_VISIBILITY
2998bool
2999operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
3000{
3001    return !__x;
3002}
3003
3004template <class _T1, class _D1>
3005inline _LIBCPP_INLINE_VISIBILITY
3006bool
3007operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
3008{
3009    return !__x;
3010}
3011
3012template <class _T1, class _D1>
3013inline _LIBCPP_INLINE_VISIBILITY
3014bool
3015operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
3016{
3017    return static_cast<bool>(__x);
3018}
3019
3020template <class _T1, class _D1>
3021inline _LIBCPP_INLINE_VISIBILITY
3022bool
3023operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
3024{
3025    return static_cast<bool>(__x);
3026}
3027
3028template <class _T1, class _D1>
3029inline _LIBCPP_INLINE_VISIBILITY
3030bool
3031operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3032{
3033    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
3034    return less<_P1>()(__x.get(), nullptr);
3035}
3036
3037template <class _T1, class _D1>
3038inline _LIBCPP_INLINE_VISIBILITY
3039bool
3040operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3041{
3042    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
3043    return less<_P1>()(nullptr, __x.get());
3044}
3045
3046template <class _T1, class _D1>
3047inline _LIBCPP_INLINE_VISIBILITY
3048bool
3049operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3050{
3051    return nullptr < __x;
3052}
3053
3054template <class _T1, class _D1>
3055inline _LIBCPP_INLINE_VISIBILITY
3056bool
3057operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3058{
3059    return __x < nullptr;
3060}
3061
3062template <class _T1, class _D1>
3063inline _LIBCPP_INLINE_VISIBILITY
3064bool
3065operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3066{
3067    return !(nullptr < __x);
3068}
3069
3070template <class _T1, class _D1>
3071inline _LIBCPP_INLINE_VISIBILITY
3072bool
3073operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3074{
3075    return !(__x < nullptr);
3076}
3077
3078template <class _T1, class _D1>
3079inline _LIBCPP_INLINE_VISIBILITY
3080bool
3081operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3082{
3083    return !(__x < nullptr);
3084}
3085
3086template <class _T1, class _D1>
3087inline _LIBCPP_INLINE_VISIBILITY
3088bool
3089operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3090{
3091    return !(nullptr < __x);
3092}
3093
3094#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3095
3096template <class _Tp, class _Dp>
3097inline _LIBCPP_INLINE_VISIBILITY
3098unique_ptr<_Tp, _Dp>
3099move(unique_ptr<_Tp, _Dp>& __t)
3100{
3101    return unique_ptr<_Tp, _Dp>(__rv<unique_ptr<_Tp, _Dp> >(__t));
3102}
3103
3104#endif
3105
3106#if _LIBCPP_STD_VER > 11
3107
3108template<class _Tp>
3109struct __unique_if
3110{
3111    typedef unique_ptr<_Tp> __unique_single;
3112};
3113
3114template<class _Tp>
3115struct __unique_if<_Tp[]>
3116{
3117    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
3118};
3119
3120template<class _Tp, size_t _Np>
3121struct __unique_if<_Tp[_Np]>
3122{
3123    typedef void __unique_array_known_bound;
3124};
3125
3126template<class _Tp, class... _Args>
3127inline _LIBCPP_INLINE_VISIBILITY
3128typename __unique_if<_Tp>::__unique_single
3129make_unique(_Args&&... __args)
3130{
3131    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
3132}
3133
3134template<class _Tp>
3135inline _LIBCPP_INLINE_VISIBILITY
3136typename __unique_if<_Tp>::__unique_array_unknown_bound
3137make_unique(size_t __n)
3138{
3139    typedef typename remove_extent<_Tp>::type _Up;
3140    return unique_ptr<_Tp>(new _Up[__n]());
3141}
3142
3143template<class _Tp, class... _Args>
3144    typename __unique_if<_Tp>::__unique_array_known_bound
3145    make_unique(_Args&&...) = delete;
3146
3147#endif  // _LIBCPP_STD_VER > 11
3148
3149template <class _Tp, class _Dp>
3150#ifdef _LIBCPP_CXX03_LANG
3151struct _LIBCPP_TEMPLATE_VIS hash<unique_ptr<_Tp, _Dp> >
3152#else
3153struct _LIBCPP_TEMPLATE_VIS hash<__enable_hash_helper<
3154    unique_ptr<_Tp, _Dp>, typename unique_ptr<_Tp, _Dp>::pointer>>
3155#endif
3156{
3157    typedef unique_ptr<_Tp, _Dp> argument_type;
3158    typedef size_t               result_type;
3159    _LIBCPP_INLINE_VISIBILITY
3160    result_type operator()(const argument_type& __ptr) const
3161    {
3162        typedef typename argument_type::pointer pointer;
3163        return hash<pointer>()(__ptr.get());
3164    }
3165};
3166
3167struct __destruct_n
3168{
3169private:
3170    size_t __size_;
3171
3172    template <class _Tp>
3173    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
3174        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
3175
3176    template <class _Tp>
3177    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
3178        {}
3179
3180    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
3181        {++__size_;}
3182    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
3183        {}
3184
3185    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
3186        {__size_ = __s;}
3187    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
3188        {}
3189public:
3190    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
3191        : __size_(__s) {}
3192
3193    template <class _Tp>
3194    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
3195        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3196
3197    template <class _Tp>
3198    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
3199        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3200
3201    template <class _Tp>
3202    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
3203        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3204};
3205
3206template <class _Alloc>
3207class __allocator_destructor
3208{
3209    typedef allocator_traits<_Alloc> __alloc_traits;
3210public:
3211    typedef typename __alloc_traits::pointer pointer;
3212    typedef typename __alloc_traits::size_type size_type;
3213private:
3214    _Alloc& __alloc_;
3215    size_type __s_;
3216public:
3217    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
3218             _NOEXCEPT
3219        : __alloc_(__a), __s_(__s) {}
3220    _LIBCPP_INLINE_VISIBILITY
3221    void operator()(pointer __p) _NOEXCEPT
3222        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
3223};
3224
3225template <class _InputIterator, class _ForwardIterator>
3226_ForwardIterator
3227uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
3228{
3229    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3230#ifndef _LIBCPP_NO_EXCEPTIONS
3231    _ForwardIterator __s = __r;
3232    try
3233    {
3234#endif
3235        for (; __f != __l; ++__f, (void) ++__r)
3236            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3237#ifndef _LIBCPP_NO_EXCEPTIONS
3238    }
3239    catch (...)
3240    {
3241        for (; __s != __r; ++__s)
3242            __s->~value_type();
3243        throw;
3244    }
3245#endif
3246    return __r;
3247}
3248
3249template <class _InputIterator, class _Size, class _ForwardIterator>
3250_ForwardIterator
3251uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
3252{
3253    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3254#ifndef _LIBCPP_NO_EXCEPTIONS
3255    _ForwardIterator __s = __r;
3256    try
3257    {
3258#endif
3259        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
3260            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3261#ifndef _LIBCPP_NO_EXCEPTIONS
3262    }
3263    catch (...)
3264    {
3265        for (; __s != __r; ++__s)
3266            __s->~value_type();
3267        throw;
3268    }
3269#endif
3270    return __r;
3271}
3272
3273template <class _ForwardIterator, class _Tp>
3274void
3275uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
3276{
3277    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3278#ifndef _LIBCPP_NO_EXCEPTIONS
3279    _ForwardIterator __s = __f;
3280    try
3281    {
3282#endif
3283        for (; __f != __l; ++__f)
3284            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3285#ifndef _LIBCPP_NO_EXCEPTIONS
3286    }
3287    catch (...)
3288    {
3289        for (; __s != __f; ++__s)
3290            __s->~value_type();
3291        throw;
3292    }
3293#endif
3294}
3295
3296template <class _ForwardIterator, class _Size, class _Tp>
3297_ForwardIterator
3298uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
3299{
3300    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3301#ifndef _LIBCPP_NO_EXCEPTIONS
3302    _ForwardIterator __s = __f;
3303    try
3304    {
3305#endif
3306        for (; __n > 0; ++__f, (void) --__n)
3307            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3308#ifndef _LIBCPP_NO_EXCEPTIONS
3309    }
3310    catch (...)
3311    {
3312        for (; __s != __f; ++__s)
3313            __s->~value_type();
3314        throw;
3315    }
3316#endif
3317    return __f;
3318}
3319
3320#if _LIBCPP_STD_VER > 14
3321
3322template <class _Tp>
3323inline _LIBCPP_INLINE_VISIBILITY
3324void destroy_at(_Tp* __loc) {
3325    _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
3326    __loc->~_Tp();
3327}
3328
3329template <class _ForwardIterator>
3330inline _LIBCPP_INLINE_VISIBILITY
3331void destroy(_ForwardIterator __first, _ForwardIterator __last) {
3332    for (; __first != __last; ++__first)
3333        _VSTD::destroy_at(_VSTD::addressof(*__first));
3334}
3335
3336template <class _ForwardIterator, class _Size>
3337inline _LIBCPP_INLINE_VISIBILITY
3338_ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
3339    for (; __n > 0; (void)++__first, --__n)
3340        _VSTD::destroy_at(_VSTD::addressof(*__first));
3341    return __first;
3342}
3343
3344template <class _ForwardIterator>
3345inline _LIBCPP_INLINE_VISIBILITY
3346void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
3347    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3348    auto __idx = __first;
3349#ifndef _LIBCPP_NO_EXCEPTIONS
3350    try {
3351#endif
3352    for (; __idx != __last; ++__idx)
3353        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3354#ifndef _LIBCPP_NO_EXCEPTIONS
3355    } catch (...) {
3356        _VSTD::destroy(__first, __idx);
3357        throw;
3358    }
3359#endif
3360}
3361
3362template <class _ForwardIterator, class _Size>
3363inline _LIBCPP_INLINE_VISIBILITY
3364_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
3365    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3366    auto __idx = __first;
3367#ifndef _LIBCPP_NO_EXCEPTIONS
3368    try {
3369#endif
3370    for (; __n > 0; (void)++__idx, --__n)
3371        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3372    return __idx;
3373#ifndef _LIBCPP_NO_EXCEPTIONS
3374    } catch (...) {
3375        _VSTD::destroy(__first, __idx);
3376        throw;
3377    }
3378#endif
3379}
3380
3381
3382template <class _ForwardIterator>
3383inline _LIBCPP_INLINE_VISIBILITY
3384void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
3385    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3386    auto __idx = __first;
3387#ifndef _LIBCPP_NO_EXCEPTIONS
3388    try {
3389#endif
3390    for (; __idx != __last; ++__idx)
3391        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3392#ifndef _LIBCPP_NO_EXCEPTIONS
3393    } catch (...) {
3394        _VSTD::destroy(__first, __idx);
3395        throw;
3396    }
3397#endif
3398}
3399
3400template <class _ForwardIterator, class _Size>
3401inline _LIBCPP_INLINE_VISIBILITY
3402_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
3403    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3404    auto __idx = __first;
3405#ifndef _LIBCPP_NO_EXCEPTIONS
3406    try {
3407#endif
3408    for (; __n > 0; (void)++__idx, --__n)
3409        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3410    return __idx;
3411#ifndef _LIBCPP_NO_EXCEPTIONS
3412    } catch (...) {
3413        _VSTD::destroy(__first, __idx);
3414        throw;
3415    }
3416#endif
3417}
3418
3419
3420template <class _InputIt, class _ForwardIt>
3421inline _LIBCPP_INLINE_VISIBILITY
3422_ForwardIt uninitialized_move(_InputIt __first, _InputIt __last, _ForwardIt __first_res) {
3423    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3424    auto __idx = __first_res;
3425#ifndef _LIBCPP_NO_EXCEPTIONS
3426    try {
3427#endif
3428    for (; __first != __last; (void)++__idx, ++__first)
3429        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3430    return __idx;
3431#ifndef _LIBCPP_NO_EXCEPTIONS
3432    } catch (...) {
3433        _VSTD::destroy(__first_res, __idx);
3434        throw;
3435    }
3436#endif
3437}
3438
3439template <class _InputIt, class _Size, class _ForwardIt>
3440inline _LIBCPP_INLINE_VISIBILITY
3441pair<_InputIt, _ForwardIt>
3442uninitialized_move_n(_InputIt __first, _Size __n, _ForwardIt __first_res) {
3443    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3444    auto __idx = __first_res;
3445#ifndef _LIBCPP_NO_EXCEPTIONS
3446    try {
3447#endif
3448    for (; __n > 0; ++__idx, (void)++__first, --__n)
3449        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3450    return {__first, __idx};
3451#ifndef _LIBCPP_NO_EXCEPTIONS
3452    } catch (...) {
3453        _VSTD::destroy(__first_res, __idx);
3454        throw;
3455    }
3456#endif
3457}
3458
3459
3460#endif // _LIBCPP_STD_VER > 14
3461
3462// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
3463// should be sufficient for thread safety.
3464// See https://bugs.llvm.org/show_bug.cgi?id=22803
3465#if defined(__clang__) && __has_builtin(__atomic_add_fetch)          \
3466                       && defined(__ATOMIC_RELAXED)                  \
3467                       && defined(__ATOMIC_ACQ_REL)
3468#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3469#elif defined(_LIBCPP_COMPILER_GCC)
3470#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3471#endif
3472
3473template <class _Tp>
3474inline _LIBCPP_INLINE_VISIBILITY _Tp
3475__libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT
3476{
3477#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3478    return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
3479#else
3480    return __t += 1;
3481#endif
3482}
3483
3484template <class _Tp>
3485inline _LIBCPP_INLINE_VISIBILITY _Tp
3486__libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT
3487{
3488#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3489    return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
3490#else
3491    return __t -= 1;
3492#endif
3493}
3494
3495class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
3496    : public std::exception
3497{
3498public:
3499    virtual ~bad_weak_ptr() _NOEXCEPT;
3500    virtual const char* what() const  _NOEXCEPT;
3501};
3502
3503_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
3504void __throw_bad_weak_ptr()
3505{
3506#ifndef _LIBCPP_NO_EXCEPTIONS
3507    throw bad_weak_ptr();
3508#else
3509    _VSTD::abort();
3510#endif
3511}
3512
3513template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr;
3514
3515class _LIBCPP_TYPE_VIS __shared_count
3516{
3517    __shared_count(const __shared_count&);
3518    __shared_count& operator=(const __shared_count&);
3519
3520protected:
3521    long __shared_owners_;
3522    virtual ~__shared_count();
3523private:
3524    virtual void __on_zero_shared() _NOEXCEPT = 0;
3525
3526public:
3527    _LIBCPP_INLINE_VISIBILITY
3528    explicit __shared_count(long __refs = 0) _NOEXCEPT
3529        : __shared_owners_(__refs) {}
3530
3531#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3532    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3533    void __add_shared() _NOEXCEPT;
3534    bool __release_shared() _NOEXCEPT;
3535#else
3536    _LIBCPP_INLINE_VISIBILITY
3537    void __add_shared() _NOEXCEPT {
3538      __libcpp_atomic_refcount_increment(__shared_owners_);
3539    }
3540    _LIBCPP_INLINE_VISIBILITY
3541    bool __release_shared() _NOEXCEPT {
3542      if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
3543        __on_zero_shared();
3544        return true;
3545      }
3546      return false;
3547    }
3548#endif
3549    _LIBCPP_INLINE_VISIBILITY
3550    long use_count() const _NOEXCEPT {
3551        return __libcpp_relaxed_load(&__shared_owners_) + 1;
3552    }
3553};
3554
3555class _LIBCPP_TYPE_VIS __shared_weak_count
3556    : private __shared_count
3557{
3558    long __shared_weak_owners_;
3559
3560public:
3561    _LIBCPP_INLINE_VISIBILITY
3562    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
3563        : __shared_count(__refs),
3564          __shared_weak_owners_(__refs) {}
3565protected:
3566    virtual ~__shared_weak_count();
3567
3568public:
3569#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3570    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3571    void __add_shared() _NOEXCEPT;
3572    void __add_weak() _NOEXCEPT;
3573    void __release_shared() _NOEXCEPT;
3574#else
3575    _LIBCPP_INLINE_VISIBILITY
3576    void __add_shared() _NOEXCEPT {
3577      __shared_count::__add_shared();
3578    }
3579    _LIBCPP_INLINE_VISIBILITY
3580    void __add_weak() _NOEXCEPT {
3581      __libcpp_atomic_refcount_increment(__shared_weak_owners_);
3582    }
3583    _LIBCPP_INLINE_VISIBILITY
3584    void __release_shared() _NOEXCEPT {
3585      if (__shared_count::__release_shared())
3586        __release_weak();
3587    }
3588#endif
3589    void __release_weak() _NOEXCEPT;
3590    _LIBCPP_INLINE_VISIBILITY
3591    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
3592    __shared_weak_count* lock() _NOEXCEPT;
3593
3594    // Define the function out only if we build static libc++ without RTTI.
3595    // Otherwise we may break clients who need to compile their projects with
3596    // -fno-rtti and yet link against a libc++.dylib compiled
3597    // without -fno-rtti.
3598#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
3599    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3600#endif
3601private:
3602    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
3603};
3604
3605template <class _Tp, class _Dp, class _Alloc>
3606class __shared_ptr_pointer
3607    : public __shared_weak_count
3608{
3609    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
3610public:
3611    _LIBCPP_INLINE_VISIBILITY
3612    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
3613        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
3614
3615#ifndef _LIBCPP_NO_RTTI
3616    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3617#endif
3618
3619private:
3620    virtual void __on_zero_shared() _NOEXCEPT;
3621    virtual void __on_zero_shared_weak() _NOEXCEPT;
3622};
3623
3624#ifndef _LIBCPP_NO_RTTI
3625
3626template <class _Tp, class _Dp, class _Alloc>
3627const void*
3628__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
3629{
3630    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr;
3631}
3632
3633#endif  // _LIBCPP_NO_RTTI
3634
3635template <class _Tp, class _Dp, class _Alloc>
3636void
3637__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
3638{
3639    __data_.first().second()(__data_.first().first());
3640    __data_.first().second().~_Dp();
3641}
3642
3643template <class _Tp, class _Dp, class _Alloc>
3644void
3645__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3646{
3647    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
3648    typedef allocator_traits<_Al> _ATraits;
3649    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3650
3651    _Al __a(__data_.second());
3652    __data_.second().~_Alloc();
3653    __a.deallocate(_PTraits::pointer_to(*this), 1);
3654}
3655
3656template <class _Tp, class _Alloc>
3657class __shared_ptr_emplace
3658    : public __shared_weak_count
3659{
3660    __compressed_pair<_Alloc, _Tp> __data_;
3661public:
3662#ifndef _LIBCPP_HAS_NO_VARIADICS
3663
3664    _LIBCPP_INLINE_VISIBILITY
3665    __shared_ptr_emplace(_Alloc __a)
3666        :  __data_(_VSTD::move(__a)) {}
3667
3668    template <class ..._Args>
3669        _LIBCPP_INLINE_VISIBILITY
3670        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
3671            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
3672                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
3673
3674#else  // _LIBCPP_HAS_NO_VARIADICS
3675
3676    _LIBCPP_INLINE_VISIBILITY
3677    __shared_ptr_emplace(_Alloc __a)
3678        :  __data_(__a) {}
3679
3680    template <class _A0>
3681        _LIBCPP_INLINE_VISIBILITY
3682        __shared_ptr_emplace(_Alloc __a, _A0& __a0)
3683            :  __data_(__a, _Tp(__a0)) {}
3684
3685    template <class _A0, class _A1>
3686        _LIBCPP_INLINE_VISIBILITY
3687        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
3688            :  __data_(__a, _Tp(__a0, __a1)) {}
3689
3690    template <class _A0, class _A1, class _A2>
3691        _LIBCPP_INLINE_VISIBILITY
3692        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
3693            :  __data_(__a, _Tp(__a0, __a1, __a2)) {}
3694
3695#endif  // _LIBCPP_HAS_NO_VARIADICS
3696
3697private:
3698    virtual void __on_zero_shared() _NOEXCEPT;
3699    virtual void __on_zero_shared_weak() _NOEXCEPT;
3700public:
3701    _LIBCPP_INLINE_VISIBILITY
3702    _Tp* get() _NOEXCEPT {return _VSTD::addressof(__data_.second());}
3703};
3704
3705template <class _Tp, class _Alloc>
3706void
3707__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
3708{
3709    __data_.second().~_Tp();
3710}
3711
3712template <class _Tp, class _Alloc>
3713void
3714__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3715{
3716    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
3717    typedef allocator_traits<_Al> _ATraits;
3718    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3719    _Al __a(__data_.first());
3720    __data_.first().~_Alloc();
3721    __a.deallocate(_PTraits::pointer_to(*this), 1);
3722}
3723
3724struct __shared_ptr_dummy_rebind_allocator_type;
3725template <>
3726class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type>
3727{
3728public:
3729    template <class _Other>
3730    struct rebind
3731    {
3732        typedef allocator<_Other> other;
3733    };
3734};
3735
3736template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
3737
3738template<class _Tp>
3739class _LIBCPP_TEMPLATE_VIS shared_ptr
3740{
3741public:
3742    typedef _Tp element_type;
3743
3744#if _LIBCPP_STD_VER > 14
3745    typedef weak_ptr<_Tp> weak_type;
3746#endif
3747private:
3748    element_type*      __ptr_;
3749    __shared_weak_count* __cntrl_;
3750
3751    struct __nat {int __for_bool_;};
3752public:
3753    _LIBCPP_INLINE_VISIBILITY
3754    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
3755    _LIBCPP_INLINE_VISIBILITY
3756    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
3757    template<class _Yp>
3758        explicit shared_ptr(_Yp* __p,
3759                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3760    template<class _Yp, class _Dp>
3761        shared_ptr(_Yp* __p, _Dp __d,
3762                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3763    template<class _Yp, class _Dp, class _Alloc>
3764        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3765                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3766    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
3767    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
3768    template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
3769    _LIBCPP_INLINE_VISIBILITY
3770    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
3771    template<class _Yp>
3772        _LIBCPP_INLINE_VISIBILITY
3773        shared_ptr(const shared_ptr<_Yp>& __r,
3774                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
3775                       _NOEXCEPT;
3776#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3777    _LIBCPP_INLINE_VISIBILITY
3778    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
3779    template<class _Yp> _LIBCPP_INLINE_VISIBILITY  shared_ptr(shared_ptr<_Yp>&& __r,
3780                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
3781                       _NOEXCEPT;
3782#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3783    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
3784                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type= __nat());
3785#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3786#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3787    template<class _Yp>
3788        shared_ptr(auto_ptr<_Yp>&& __r,
3789                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3790#else
3791    template<class _Yp>
3792        shared_ptr(auto_ptr<_Yp> __r,
3793                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3794#endif
3795#endif
3796#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3797    template <class _Yp, class _Dp>
3798        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3799                   typename enable_if
3800                   <
3801                       !is_lvalue_reference<_Dp>::value &&
3802                       !is_array<_Yp>::value &&
3803                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3804                       __nat
3805                   >::type = __nat());
3806    template <class _Yp, class _Dp>
3807        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3808                   typename enable_if
3809                   <
3810                       is_lvalue_reference<_Dp>::value &&
3811                       !is_array<_Yp>::value &&
3812                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3813                       __nat
3814                   >::type = __nat());
3815#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3816    template <class _Yp, class _Dp>
3817        shared_ptr(unique_ptr<_Yp, _Dp>,
3818                   typename enable_if
3819                   <
3820                       !is_lvalue_reference<_Dp>::value &&
3821                       !is_array<_Yp>::value &&
3822                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3823                       __nat
3824                   >::type = __nat());
3825    template <class _Yp, class _Dp>
3826        shared_ptr(unique_ptr<_Yp, _Dp>,
3827                   typename enable_if
3828                   <
3829                       is_lvalue_reference<_Dp>::value &&
3830                       !is_array<_Yp>::value &&
3831                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3832                       __nat
3833                   >::type = __nat());
3834#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3835
3836    ~shared_ptr();
3837
3838    _LIBCPP_INLINE_VISIBILITY
3839    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
3840    template<class _Yp>
3841        typename enable_if
3842        <
3843            is_convertible<_Yp*, element_type*>::value,
3844            shared_ptr&
3845        >::type
3846        _LIBCPP_INLINE_VISIBILITY
3847        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
3848#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3849    _LIBCPP_INLINE_VISIBILITY
3850    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
3851    template<class _Yp>
3852        typename enable_if
3853        <
3854            is_convertible<_Yp*, element_type*>::value,
3855            shared_ptr<_Tp>&
3856        >::type
3857        _LIBCPP_INLINE_VISIBILITY
3858        operator=(shared_ptr<_Yp>&& __r);
3859#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3860    template<class _Yp>
3861        _LIBCPP_INLINE_VISIBILITY
3862        typename enable_if
3863        <
3864            !is_array<_Yp>::value &&
3865            is_convertible<_Yp*, element_type*>::value,
3866            shared_ptr
3867        >::type&
3868        operator=(auto_ptr<_Yp>&& __r);
3869#endif
3870#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3871#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3872    template<class _Yp>
3873        _LIBCPP_INLINE_VISIBILITY
3874        typename enable_if
3875        <
3876            !is_array<_Yp>::value &&
3877            is_convertible<_Yp*, element_type*>::value,
3878            shared_ptr&
3879        >::type
3880        operator=(auto_ptr<_Yp> __r);
3881#endif
3882#endif
3883    template <class _Yp, class _Dp>
3884        typename enable_if
3885        <
3886            !is_array<_Yp>::value &&
3887            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3888            shared_ptr&
3889        >::type
3890#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3891        _LIBCPP_INLINE_VISIBILITY
3892        operator=(unique_ptr<_Yp, _Dp>&& __r);
3893#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3894        _LIBCPP_INLINE_VISIBILITY
3895        operator=(unique_ptr<_Yp, _Dp> __r);
3896#endif
3897
3898    _LIBCPP_INLINE_VISIBILITY
3899    void swap(shared_ptr& __r) _NOEXCEPT;
3900    _LIBCPP_INLINE_VISIBILITY
3901    void reset() _NOEXCEPT;
3902    template<class _Yp>
3903        typename enable_if
3904        <
3905            is_convertible<_Yp*, element_type*>::value,
3906            void
3907        >::type
3908        _LIBCPP_INLINE_VISIBILITY
3909        reset(_Yp* __p);
3910    template<class _Yp, class _Dp>
3911        typename enable_if
3912        <
3913            is_convertible<_Yp*, element_type*>::value,
3914            void
3915        >::type
3916        _LIBCPP_INLINE_VISIBILITY
3917        reset(_Yp* __p, _Dp __d);
3918    template<class _Yp, class _Dp, class _Alloc>
3919        typename enable_if
3920        <
3921            is_convertible<_Yp*, element_type*>::value,
3922            void
3923        >::type
3924        _LIBCPP_INLINE_VISIBILITY
3925        reset(_Yp* __p, _Dp __d, _Alloc __a);
3926
3927    _LIBCPP_INLINE_VISIBILITY
3928    element_type* get() const _NOEXCEPT {return __ptr_;}
3929    _LIBCPP_INLINE_VISIBILITY
3930    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
3931        {return *__ptr_;}
3932    _LIBCPP_INLINE_VISIBILITY
3933    element_type* operator->() const _NOEXCEPT {return __ptr_;}
3934    _LIBCPP_INLINE_VISIBILITY
3935    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
3936    _LIBCPP_INLINE_VISIBILITY
3937    bool unique() const _NOEXCEPT {return use_count() == 1;}
3938    _LIBCPP_INLINE_VISIBILITY
3939    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
3940    template <class _Up>
3941        _LIBCPP_INLINE_VISIBILITY
3942        bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT
3943        {return __cntrl_ < __p.__cntrl_;}
3944    template <class _Up>
3945        _LIBCPP_INLINE_VISIBILITY
3946        bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT
3947        {return __cntrl_ < __p.__cntrl_;}
3948    _LIBCPP_INLINE_VISIBILITY
3949    bool
3950    __owner_equivalent(const shared_ptr& __p) const
3951        {return __cntrl_ == __p.__cntrl_;}
3952
3953#ifndef _LIBCPP_NO_RTTI
3954    template <class _Dp>
3955        _LIBCPP_INLINE_VISIBILITY
3956        _Dp* __get_deleter() const _NOEXCEPT
3957            {return static_cast<_Dp*>(__cntrl_
3958                    ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp)))
3959                      : nullptr);}
3960#endif  // _LIBCPP_NO_RTTI
3961
3962#ifndef _LIBCPP_HAS_NO_VARIADICS
3963
3964    template<class ..._Args>
3965        static
3966        shared_ptr<_Tp>
3967        make_shared(_Args&& ...__args);
3968
3969    template<class _Alloc, class ..._Args>
3970        static
3971        shared_ptr<_Tp>
3972        allocate_shared(const _Alloc& __a, _Args&& ...__args);
3973
3974#else  // _LIBCPP_HAS_NO_VARIADICS
3975
3976    static shared_ptr<_Tp> make_shared();
3977
3978    template<class _A0>
3979        static shared_ptr<_Tp> make_shared(_A0&);
3980
3981    template<class _A0, class _A1>
3982        static shared_ptr<_Tp> make_shared(_A0&, _A1&);
3983
3984    template<class _A0, class _A1, class _A2>
3985        static shared_ptr<_Tp> make_shared(_A0&, _A1&, _A2&);
3986
3987    template<class _Alloc>
3988        static shared_ptr<_Tp>
3989        allocate_shared(const _Alloc& __a);
3990
3991    template<class _Alloc, class _A0>
3992        static shared_ptr<_Tp>
3993        allocate_shared(const _Alloc& __a, _A0& __a0);
3994
3995    template<class _Alloc, class _A0, class _A1>
3996        static shared_ptr<_Tp>
3997        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1);
3998
3999    template<class _Alloc, class _A0, class _A1, class _A2>
4000        static shared_ptr<_Tp>
4001        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2);
4002
4003#endif  // _LIBCPP_HAS_NO_VARIADICS
4004
4005private:
4006    template <class _Yp, bool = is_function<_Yp>::value>
4007        struct __shared_ptr_default_allocator
4008        {
4009            typedef allocator<_Yp> type;
4010        };
4011
4012    template <class _Yp>
4013        struct __shared_ptr_default_allocator<_Yp, true>
4014        {
4015            typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
4016        };
4017
4018    template <class _Yp, class _OrigPtr>
4019        _LIBCPP_INLINE_VISIBILITY
4020        typename enable_if<is_convertible<_OrigPtr*,
4021                                          const enable_shared_from_this<_Yp>*
4022        >::value,
4023            void>::type
4024        __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
4025                           _OrigPtr* __ptr) _NOEXCEPT
4026        {
4027            typedef typename remove_cv<_Yp>::type _RawYp;
4028            if (__e && __e->__weak_this_.expired())
4029            {
4030                __e->__weak_this_ = shared_ptr<_RawYp>(*this,
4031                    const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
4032            }
4033        }
4034
4035    _LIBCPP_INLINE_VISIBILITY void __enable_weak_this(...) _NOEXCEPT {}
4036
4037    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
4038    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
4039};
4040
4041
4042template<class _Tp>
4043inline
4044_LIBCPP_CONSTEXPR
4045shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
4046    : __ptr_(0),
4047      __cntrl_(0)
4048{
4049}
4050
4051template<class _Tp>
4052inline
4053_LIBCPP_CONSTEXPR
4054shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
4055    : __ptr_(0),
4056      __cntrl_(0)
4057{
4058}
4059
4060template<class _Tp>
4061template<class _Yp>
4062shared_ptr<_Tp>::shared_ptr(_Yp* __p,
4063                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4064    : __ptr_(__p)
4065{
4066    unique_ptr<_Yp> __hold(__p);
4067    typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4068    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, _AllocT > _CntrlBlk;
4069    __cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), _AllocT());
4070    __hold.release();
4071    __enable_weak_this(__p, __p);
4072}
4073
4074template<class _Tp>
4075template<class _Yp, class _Dp>
4076shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
4077                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4078    : __ptr_(__p)
4079{
4080#ifndef _LIBCPP_NO_EXCEPTIONS
4081    try
4082    {
4083#endif  // _LIBCPP_NO_EXCEPTIONS
4084        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4085        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
4086        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
4087        __enable_weak_this(__p, __p);
4088#ifndef _LIBCPP_NO_EXCEPTIONS
4089    }
4090    catch (...)
4091    {
4092        __d(__p);
4093        throw;
4094    }
4095#endif  // _LIBCPP_NO_EXCEPTIONS
4096}
4097
4098template<class _Tp>
4099template<class _Dp>
4100shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
4101    : __ptr_(0)
4102{
4103#ifndef _LIBCPP_NO_EXCEPTIONS
4104    try
4105    {
4106#endif  // _LIBCPP_NO_EXCEPTIONS
4107        typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
4108        typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
4109        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
4110#ifndef _LIBCPP_NO_EXCEPTIONS
4111    }
4112    catch (...)
4113    {
4114        __d(__p);
4115        throw;
4116    }
4117#endif  // _LIBCPP_NO_EXCEPTIONS
4118}
4119
4120template<class _Tp>
4121template<class _Yp, class _Dp, class _Alloc>
4122shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
4123                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4124    : __ptr_(__p)
4125{
4126#ifndef _LIBCPP_NO_EXCEPTIONS
4127    try
4128    {
4129#endif  // _LIBCPP_NO_EXCEPTIONS
4130        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
4131        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4132        typedef __allocator_destructor<_A2> _D2;
4133        _A2 __a2(__a);
4134        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4135        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4136            _CntrlBlk(__p, __d, __a);
4137        __cntrl_ = _VSTD::addressof(*__hold2.release());
4138        __enable_weak_this(__p, __p);
4139#ifndef _LIBCPP_NO_EXCEPTIONS
4140    }
4141    catch (...)
4142    {
4143        __d(__p);
4144        throw;
4145    }
4146#endif  // _LIBCPP_NO_EXCEPTIONS
4147}
4148
4149template<class _Tp>
4150template<class _Dp, class _Alloc>
4151shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
4152    : __ptr_(0)
4153{
4154#ifndef _LIBCPP_NO_EXCEPTIONS
4155    try
4156    {
4157#endif  // _LIBCPP_NO_EXCEPTIONS
4158        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
4159        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4160        typedef __allocator_destructor<_A2> _D2;
4161        _A2 __a2(__a);
4162        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4163        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4164            _CntrlBlk(__p, __d, __a);
4165        __cntrl_ = _VSTD::addressof(*__hold2.release());
4166#ifndef _LIBCPP_NO_EXCEPTIONS
4167    }
4168    catch (...)
4169    {
4170        __d(__p);
4171        throw;
4172    }
4173#endif  // _LIBCPP_NO_EXCEPTIONS
4174}
4175
4176template<class _Tp>
4177template<class _Yp>
4178inline
4179shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
4180    : __ptr_(__p),
4181      __cntrl_(__r.__cntrl_)
4182{
4183    if (__cntrl_)
4184        __cntrl_->__add_shared();
4185}
4186
4187template<class _Tp>
4188inline
4189shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
4190    : __ptr_(__r.__ptr_),
4191      __cntrl_(__r.__cntrl_)
4192{
4193    if (__cntrl_)
4194        __cntrl_->__add_shared();
4195}
4196
4197template<class _Tp>
4198template<class _Yp>
4199inline
4200shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
4201                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4202         _NOEXCEPT
4203    : __ptr_(__r.__ptr_),
4204      __cntrl_(__r.__cntrl_)
4205{
4206    if (__cntrl_)
4207        __cntrl_->__add_shared();
4208}
4209
4210#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4211
4212template<class _Tp>
4213inline
4214shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
4215    : __ptr_(__r.__ptr_),
4216      __cntrl_(__r.__cntrl_)
4217{
4218    __r.__ptr_ = 0;
4219    __r.__cntrl_ = 0;
4220}
4221
4222template<class _Tp>
4223template<class _Yp>
4224inline
4225shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
4226                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4227         _NOEXCEPT
4228    : __ptr_(__r.__ptr_),
4229      __cntrl_(__r.__cntrl_)
4230{
4231    __r.__ptr_ = 0;
4232    __r.__cntrl_ = 0;
4233}
4234
4235#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4236
4237#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4238template<class _Tp>
4239template<class _Yp>
4240#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4241shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
4242#else
4243shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp> __r,
4244#endif
4245                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4246    : __ptr_(__r.get())
4247{
4248    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
4249    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
4250    __enable_weak_this(__r.get(), __r.get());
4251    __r.release();
4252}
4253#endif
4254
4255template<class _Tp>
4256template <class _Yp, class _Dp>
4257#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4258shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4259#else
4260shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4261#endif
4262                            typename enable_if
4263                            <
4264                                !is_lvalue_reference<_Dp>::value &&
4265                                !is_array<_Yp>::value &&
4266                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4267                                __nat
4268                            >::type)
4269    : __ptr_(__r.get())
4270{
4271#if _LIBCPP_STD_VER > 11
4272    if (__ptr_ == nullptr)
4273        __cntrl_ = nullptr;
4274    else
4275#endif
4276    {
4277        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4278        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
4279        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), _AllocT());
4280        __enable_weak_this(__r.get(), __r.get());
4281    }
4282    __r.release();
4283}
4284
4285template<class _Tp>
4286template <class _Yp, class _Dp>
4287#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4288shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4289#else
4290shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4291#endif
4292                            typename enable_if
4293                            <
4294                                is_lvalue_reference<_Dp>::value &&
4295                                !is_array<_Yp>::value &&
4296                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4297                                __nat
4298                            >::type)
4299    : __ptr_(__r.get())
4300{
4301#if _LIBCPP_STD_VER > 11
4302    if (__ptr_ == nullptr)
4303        __cntrl_ = nullptr;
4304    else
4305#endif
4306    {
4307        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4308        typedef __shared_ptr_pointer<_Yp*,
4309                                     reference_wrapper<typename remove_reference<_Dp>::type>,
4310                                     _AllocT > _CntrlBlk;
4311        __cntrl_ = new _CntrlBlk(__r.get(), ref(__r.get_deleter()), _AllocT());
4312        __enable_weak_this(__r.get(), __r.get());
4313    }
4314    __r.release();
4315}
4316
4317#ifndef _LIBCPP_HAS_NO_VARIADICS
4318
4319template<class _Tp>
4320template<class ..._Args>
4321shared_ptr<_Tp>
4322shared_ptr<_Tp>::make_shared(_Args&& ...__args)
4323{
4324    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in make_shared" );
4325    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4326    typedef allocator<_CntrlBlk> _A2;
4327    typedef __allocator_destructor<_A2> _D2;
4328    _A2 __a2;
4329    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4330    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
4331    shared_ptr<_Tp> __r;
4332    __r.__ptr_ = __hold2.get()->get();
4333    __r.__cntrl_ = __hold2.release();
4334    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4335    return __r;
4336}
4337
4338template<class _Tp>
4339template<class _Alloc, class ..._Args>
4340shared_ptr<_Tp>
4341shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _Args&& ...__args)
4342{
4343    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in allocate_shared" );
4344    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4345    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4346    typedef __allocator_destructor<_A2> _D2;
4347    _A2 __a2(__a);
4348    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4349    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4350        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
4351    shared_ptr<_Tp> __r;
4352    __r.__ptr_ = __hold2.get()->get();
4353    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4354    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4355    return __r;
4356}
4357
4358#else  // _LIBCPP_HAS_NO_VARIADICS
4359
4360template<class _Tp>
4361shared_ptr<_Tp>
4362shared_ptr<_Tp>::make_shared()
4363{
4364    static_assert((is_constructible<_Tp>::value), "Can't construct object in make_shared" );
4365    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4366    typedef allocator<_CntrlBlk> _Alloc2;
4367    typedef __allocator_destructor<_Alloc2> _D2;
4368    _Alloc2 __alloc2;
4369    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4370    ::new(__hold2.get()) _CntrlBlk(__alloc2);
4371    shared_ptr<_Tp> __r;
4372    __r.__ptr_ = __hold2.get()->get();
4373    __r.__cntrl_ = __hold2.release();
4374    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4375    return __r;
4376}
4377
4378template<class _Tp>
4379template<class _A0>
4380shared_ptr<_Tp>
4381shared_ptr<_Tp>::make_shared(_A0& __a0)
4382{
4383    static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in make_shared" );
4384    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4385    typedef allocator<_CntrlBlk> _Alloc2;
4386    typedef __allocator_destructor<_Alloc2> _D2;
4387    _Alloc2 __alloc2;
4388    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4389    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0);
4390    shared_ptr<_Tp> __r;
4391    __r.__ptr_ = __hold2.get()->get();
4392    __r.__cntrl_ = __hold2.release();
4393    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4394    return __r;
4395}
4396
4397template<class _Tp>
4398template<class _A0, class _A1>
4399shared_ptr<_Tp>
4400shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1)
4401{
4402    static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in make_shared" );
4403    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4404    typedef allocator<_CntrlBlk> _Alloc2;
4405    typedef __allocator_destructor<_Alloc2> _D2;
4406    _Alloc2 __alloc2;
4407    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4408    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1);
4409    shared_ptr<_Tp> __r;
4410    __r.__ptr_ = __hold2.get()->get();
4411    __r.__cntrl_ = __hold2.release();
4412    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4413    return __r;
4414}
4415
4416template<class _Tp>
4417template<class _A0, class _A1, class _A2>
4418shared_ptr<_Tp>
4419shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
4420{
4421    static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in make_shared" );
4422    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4423    typedef allocator<_CntrlBlk> _Alloc2;
4424    typedef __allocator_destructor<_Alloc2> _D2;
4425    _Alloc2 __alloc2;
4426    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4427    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1, __a2);
4428    shared_ptr<_Tp> __r;
4429    __r.__ptr_ = __hold2.get()->get();
4430    __r.__cntrl_ = __hold2.release();
4431    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4432    return __r;
4433}
4434
4435template<class _Tp>
4436template<class _Alloc>
4437shared_ptr<_Tp>
4438shared_ptr<_Tp>::allocate_shared(const _Alloc& __a)
4439{
4440    static_assert((is_constructible<_Tp>::value), "Can't construct object in allocate_shared" );
4441    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4442    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4443    typedef __allocator_destructor<_Alloc2> _D2;
4444    _Alloc2 __alloc2(__a);
4445    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4446    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4447        _CntrlBlk(__a);
4448    shared_ptr<_Tp> __r;
4449    __r.__ptr_ = __hold2.get()->get();
4450    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4451    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4452    return __r;
4453}
4454
4455template<class _Tp>
4456template<class _Alloc, class _A0>
4457shared_ptr<_Tp>
4458shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0)
4459{
4460    static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in allocate_shared" );
4461    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4462    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4463    typedef __allocator_destructor<_Alloc2> _D2;
4464    _Alloc2 __alloc2(__a);
4465    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4466    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4467        _CntrlBlk(__a, __a0);
4468    shared_ptr<_Tp> __r;
4469    __r.__ptr_ = __hold2.get()->get();
4470    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4471    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4472    return __r;
4473}
4474
4475template<class _Tp>
4476template<class _Alloc, class _A0, class _A1>
4477shared_ptr<_Tp>
4478shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
4479{
4480    static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in allocate_shared" );
4481    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4482    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4483    typedef __allocator_destructor<_Alloc2> _D2;
4484    _Alloc2 __alloc2(__a);
4485    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4486    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4487        _CntrlBlk(__a, __a0, __a1);
4488    shared_ptr<_Tp> __r;
4489    __r.__ptr_ = __hold2.get()->get();
4490    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4491    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4492    return __r;
4493}
4494
4495template<class _Tp>
4496template<class _Alloc, class _A0, class _A1, class _A2>
4497shared_ptr<_Tp>
4498shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
4499{
4500    static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in allocate_shared" );
4501    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4502    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4503    typedef __allocator_destructor<_Alloc2> _D2;
4504    _Alloc2 __alloc2(__a);
4505    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4506    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4507        _CntrlBlk(__a, __a0, __a1, __a2);
4508    shared_ptr<_Tp> __r;
4509    __r.__ptr_ = __hold2.get()->get();
4510    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4511    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4512    return __r;
4513}
4514
4515#endif  // _LIBCPP_HAS_NO_VARIADICS
4516
4517template<class _Tp>
4518shared_ptr<_Tp>::~shared_ptr()
4519{
4520    if (__cntrl_)
4521        __cntrl_->__release_shared();
4522}
4523
4524template<class _Tp>
4525inline
4526shared_ptr<_Tp>&
4527shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
4528{
4529    shared_ptr(__r).swap(*this);
4530    return *this;
4531}
4532
4533template<class _Tp>
4534template<class _Yp>
4535inline
4536typename enable_if
4537<
4538    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4539    shared_ptr<_Tp>&
4540>::type
4541shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
4542{
4543    shared_ptr(__r).swap(*this);
4544    return *this;
4545}
4546
4547#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4548
4549template<class _Tp>
4550inline
4551shared_ptr<_Tp>&
4552shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
4553{
4554    shared_ptr(_VSTD::move(__r)).swap(*this);
4555    return *this;
4556}
4557
4558template<class _Tp>
4559template<class _Yp>
4560inline
4561typename enable_if
4562<
4563    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4564    shared_ptr<_Tp>&
4565>::type
4566shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
4567{
4568    shared_ptr(_VSTD::move(__r)).swap(*this);
4569    return *this;
4570}
4571
4572#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4573template<class _Tp>
4574template<class _Yp>
4575inline
4576typename enable_if
4577<
4578    !is_array<_Yp>::value &&
4579    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4580    shared_ptr<_Tp>
4581>::type&
4582shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
4583{
4584    shared_ptr(_VSTD::move(__r)).swap(*this);
4585    return *this;
4586}
4587#endif
4588
4589template<class _Tp>
4590template <class _Yp, class _Dp>
4591inline
4592typename enable_if
4593<
4594    !is_array<_Yp>::value &&
4595    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4596                   typename shared_ptr<_Tp>::element_type*>::value,
4597    shared_ptr<_Tp>&
4598>::type
4599shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
4600{
4601    shared_ptr(_VSTD::move(__r)).swap(*this);
4602    return *this;
4603}
4604
4605#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4606
4607#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4608template<class _Tp>
4609template<class _Yp>
4610inline _LIBCPP_INLINE_VISIBILITY
4611typename enable_if
4612<
4613    !is_array<_Yp>::value &&
4614    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4615    shared_ptr<_Tp>&
4616>::type
4617shared_ptr<_Tp>::operator=(auto_ptr<_Yp> __r)
4618{
4619    shared_ptr(__r).swap(*this);
4620    return *this;
4621}
4622#endif
4623
4624template<class _Tp>
4625template <class _Yp, class _Dp>
4626inline _LIBCPP_INLINE_VISIBILITY
4627typename enable_if
4628<
4629    !is_array<_Yp>::value &&
4630    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4631                   typename shared_ptr<_Tp>::element_type*>::value,
4632    shared_ptr<_Tp>&
4633>::type
4634shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp> __r)
4635{
4636    shared_ptr(_VSTD::move(__r)).swap(*this);
4637    return *this;
4638}
4639
4640#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4641
4642template<class _Tp>
4643inline
4644void
4645shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
4646{
4647    _VSTD::swap(__ptr_, __r.__ptr_);
4648    _VSTD::swap(__cntrl_, __r.__cntrl_);
4649}
4650
4651template<class _Tp>
4652inline
4653void
4654shared_ptr<_Tp>::reset() _NOEXCEPT
4655{
4656    shared_ptr().swap(*this);
4657}
4658
4659template<class _Tp>
4660template<class _Yp>
4661inline
4662typename enable_if
4663<
4664    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4665    void
4666>::type
4667shared_ptr<_Tp>::reset(_Yp* __p)
4668{
4669    shared_ptr(__p).swap(*this);
4670}
4671
4672template<class _Tp>
4673template<class _Yp, class _Dp>
4674inline
4675typename enable_if
4676<
4677    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4678    void
4679>::type
4680shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
4681{
4682    shared_ptr(__p, __d).swap(*this);
4683}
4684
4685template<class _Tp>
4686template<class _Yp, class _Dp, class _Alloc>
4687inline
4688typename enable_if
4689<
4690    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4691    void
4692>::type
4693shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
4694{
4695    shared_ptr(__p, __d, __a).swap(*this);
4696}
4697
4698#ifndef _LIBCPP_HAS_NO_VARIADICS
4699
4700template<class _Tp, class ..._Args>
4701inline _LIBCPP_INLINE_VISIBILITY
4702typename enable_if
4703<
4704    !is_array<_Tp>::value,
4705    shared_ptr<_Tp>
4706>::type
4707make_shared(_Args&& ...__args)
4708{
4709    return shared_ptr<_Tp>::make_shared(_VSTD::forward<_Args>(__args)...);
4710}
4711
4712template<class _Tp, class _Alloc, class ..._Args>
4713inline _LIBCPP_INLINE_VISIBILITY
4714typename enable_if
4715<
4716    !is_array<_Tp>::value,
4717    shared_ptr<_Tp>
4718>::type
4719allocate_shared(const _Alloc& __a, _Args&& ...__args)
4720{
4721    return shared_ptr<_Tp>::allocate_shared(__a, _VSTD::forward<_Args>(__args)...);
4722}
4723
4724#else  // _LIBCPP_HAS_NO_VARIADICS
4725
4726template<class _Tp>
4727inline _LIBCPP_INLINE_VISIBILITY
4728shared_ptr<_Tp>
4729make_shared()
4730{
4731    return shared_ptr<_Tp>::make_shared();
4732}
4733
4734template<class _Tp, class _A0>
4735inline _LIBCPP_INLINE_VISIBILITY
4736shared_ptr<_Tp>
4737make_shared(_A0& __a0)
4738{
4739    return shared_ptr<_Tp>::make_shared(__a0);
4740}
4741
4742template<class _Tp, class _A0, class _A1>
4743inline _LIBCPP_INLINE_VISIBILITY
4744shared_ptr<_Tp>
4745make_shared(_A0& __a0, _A1& __a1)
4746{
4747    return shared_ptr<_Tp>::make_shared(__a0, __a1);
4748}
4749
4750template<class _Tp, class _A0, class _A1, class _A2>
4751inline _LIBCPP_INLINE_VISIBILITY
4752shared_ptr<_Tp>
4753make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
4754{
4755    return shared_ptr<_Tp>::make_shared(__a0, __a1, __a2);
4756}
4757
4758template<class _Tp, class _Alloc>
4759inline _LIBCPP_INLINE_VISIBILITY
4760shared_ptr<_Tp>
4761allocate_shared(const _Alloc& __a)
4762{
4763    return shared_ptr<_Tp>::allocate_shared(__a);
4764}
4765
4766template<class _Tp, class _Alloc, class _A0>
4767inline _LIBCPP_INLINE_VISIBILITY
4768shared_ptr<_Tp>
4769allocate_shared(const _Alloc& __a, _A0& __a0)
4770{
4771    return shared_ptr<_Tp>::allocate_shared(__a, __a0);
4772}
4773
4774template<class _Tp, class _Alloc, class _A0, class _A1>
4775inline _LIBCPP_INLINE_VISIBILITY
4776shared_ptr<_Tp>
4777allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
4778{
4779    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1);
4780}
4781
4782template<class _Tp, class _Alloc, class _A0, class _A1, class _A2>
4783inline _LIBCPP_INLINE_VISIBILITY
4784shared_ptr<_Tp>
4785allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
4786{
4787    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1, __a2);
4788}
4789
4790#endif  // _LIBCPP_HAS_NO_VARIADICS
4791
4792template<class _Tp, class _Up>
4793inline _LIBCPP_INLINE_VISIBILITY
4794bool
4795operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4796{
4797    return __x.get() == __y.get();
4798}
4799
4800template<class _Tp, class _Up>
4801inline _LIBCPP_INLINE_VISIBILITY
4802bool
4803operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4804{
4805    return !(__x == __y);
4806}
4807
4808template<class _Tp, class _Up>
4809inline _LIBCPP_INLINE_VISIBILITY
4810bool
4811operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4812{
4813#if _LIBCPP_STD_VER <= 11
4814    typedef typename common_type<_Tp*, _Up*>::type _Vp;
4815    return less<_Vp>()(__x.get(), __y.get());
4816#else
4817    return less<>()(__x.get(), __y.get());
4818#endif
4819
4820}
4821
4822template<class _Tp, class _Up>
4823inline _LIBCPP_INLINE_VISIBILITY
4824bool
4825operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4826{
4827    return __y < __x;
4828}
4829
4830template<class _Tp, class _Up>
4831inline _LIBCPP_INLINE_VISIBILITY
4832bool
4833operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4834{
4835    return !(__y < __x);
4836}
4837
4838template<class _Tp, class _Up>
4839inline _LIBCPP_INLINE_VISIBILITY
4840bool
4841operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4842{
4843    return !(__x < __y);
4844}
4845
4846template<class _Tp>
4847inline _LIBCPP_INLINE_VISIBILITY
4848bool
4849operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4850{
4851    return !__x;
4852}
4853
4854template<class _Tp>
4855inline _LIBCPP_INLINE_VISIBILITY
4856bool
4857operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4858{
4859    return !__x;
4860}
4861
4862template<class _Tp>
4863inline _LIBCPP_INLINE_VISIBILITY
4864bool
4865operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4866{
4867    return static_cast<bool>(__x);
4868}
4869
4870template<class _Tp>
4871inline _LIBCPP_INLINE_VISIBILITY
4872bool
4873operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4874{
4875    return static_cast<bool>(__x);
4876}
4877
4878template<class _Tp>
4879inline _LIBCPP_INLINE_VISIBILITY
4880bool
4881operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4882{
4883    return less<_Tp*>()(__x.get(), nullptr);
4884}
4885
4886template<class _Tp>
4887inline _LIBCPP_INLINE_VISIBILITY
4888bool
4889operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4890{
4891    return less<_Tp*>()(nullptr, __x.get());
4892}
4893
4894template<class _Tp>
4895inline _LIBCPP_INLINE_VISIBILITY
4896bool
4897operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4898{
4899    return nullptr < __x;
4900}
4901
4902template<class _Tp>
4903inline _LIBCPP_INLINE_VISIBILITY
4904bool
4905operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4906{
4907    return __x < nullptr;
4908}
4909
4910template<class _Tp>
4911inline _LIBCPP_INLINE_VISIBILITY
4912bool
4913operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4914{
4915    return !(nullptr < __x);
4916}
4917
4918template<class _Tp>
4919inline _LIBCPP_INLINE_VISIBILITY
4920bool
4921operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4922{
4923    return !(__x < nullptr);
4924}
4925
4926template<class _Tp>
4927inline _LIBCPP_INLINE_VISIBILITY
4928bool
4929operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4930{
4931    return !(__x < nullptr);
4932}
4933
4934template<class _Tp>
4935inline _LIBCPP_INLINE_VISIBILITY
4936bool
4937operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4938{
4939    return !(nullptr < __x);
4940}
4941
4942template<class _Tp>
4943inline _LIBCPP_INLINE_VISIBILITY
4944void
4945swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
4946{
4947    __x.swap(__y);
4948}
4949
4950template<class _Tp, class _Up>
4951inline _LIBCPP_INLINE_VISIBILITY
4952typename enable_if
4953<
4954    !is_array<_Tp>::value && !is_array<_Up>::value,
4955    shared_ptr<_Tp>
4956>::type
4957static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4958{
4959    return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get()));
4960}
4961
4962template<class _Tp, class _Up>
4963inline _LIBCPP_INLINE_VISIBILITY
4964typename enable_if
4965<
4966    !is_array<_Tp>::value && !is_array<_Up>::value,
4967    shared_ptr<_Tp>
4968>::type
4969dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4970{
4971    _Tp* __p = dynamic_cast<_Tp*>(__r.get());
4972    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
4973}
4974
4975template<class _Tp, class _Up>
4976typename enable_if
4977<
4978    is_array<_Tp>::value == is_array<_Up>::value,
4979    shared_ptr<_Tp>
4980>::type
4981const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4982{
4983    typedef typename remove_extent<_Tp>::type _RTp;
4984    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
4985}
4986
4987#ifndef _LIBCPP_NO_RTTI
4988
4989template<class _Dp, class _Tp>
4990inline _LIBCPP_INLINE_VISIBILITY
4991_Dp*
4992get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
4993{
4994    return __p.template __get_deleter<_Dp>();
4995}
4996
4997#endif  // _LIBCPP_NO_RTTI
4998
4999template<class _Tp>
5000class _LIBCPP_TEMPLATE_VIS weak_ptr
5001{
5002public:
5003    typedef _Tp element_type;
5004private:
5005    element_type*        __ptr_;
5006    __shared_weak_count* __cntrl_;
5007
5008public:
5009    _LIBCPP_INLINE_VISIBILITY
5010    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
5011    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r,
5012                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
5013                        _NOEXCEPT;
5014    _LIBCPP_INLINE_VISIBILITY
5015    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
5016    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r,
5017                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
5018                         _NOEXCEPT;
5019
5020#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5021    _LIBCPP_INLINE_VISIBILITY
5022    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
5023    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r,
5024                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
5025                         _NOEXCEPT;
5026#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5027    ~weak_ptr();
5028
5029    _LIBCPP_INLINE_VISIBILITY
5030    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
5031    template<class _Yp>
5032        typename enable_if
5033        <
5034            is_convertible<_Yp*, element_type*>::value,
5035            weak_ptr&
5036        >::type
5037        _LIBCPP_INLINE_VISIBILITY
5038        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
5039
5040#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5041
5042    _LIBCPP_INLINE_VISIBILITY
5043    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
5044    template<class _Yp>
5045        typename enable_if
5046        <
5047            is_convertible<_Yp*, element_type*>::value,
5048            weak_ptr&
5049        >::type
5050        _LIBCPP_INLINE_VISIBILITY
5051        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
5052
5053#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5054
5055    template<class _Yp>
5056        typename enable_if
5057        <
5058            is_convertible<_Yp*, element_type*>::value,
5059            weak_ptr&
5060        >::type
5061        _LIBCPP_INLINE_VISIBILITY
5062        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
5063
5064    _LIBCPP_INLINE_VISIBILITY
5065    void swap(weak_ptr& __r) _NOEXCEPT;
5066    _LIBCPP_INLINE_VISIBILITY
5067    void reset() _NOEXCEPT;
5068
5069    _LIBCPP_INLINE_VISIBILITY
5070    long use_count() const _NOEXCEPT
5071        {return __cntrl_ ? __cntrl_->use_count() : 0;}
5072    _LIBCPP_INLINE_VISIBILITY
5073    bool expired() const _NOEXCEPT
5074        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
5075    shared_ptr<_Tp> lock() const _NOEXCEPT;
5076    template<class _Up>
5077        _LIBCPP_INLINE_VISIBILITY
5078        bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT
5079        {return __cntrl_ < __r.__cntrl_;}
5080    template<class _Up>
5081        _LIBCPP_INLINE_VISIBILITY
5082        bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT
5083        {return __cntrl_ < __r.__cntrl_;}
5084
5085    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
5086    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
5087};
5088
5089template<class _Tp>
5090inline
5091_LIBCPP_CONSTEXPR
5092weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
5093    : __ptr_(0),
5094      __cntrl_(0)
5095{
5096}
5097
5098template<class _Tp>
5099inline
5100weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
5101    : __ptr_(__r.__ptr_),
5102      __cntrl_(__r.__cntrl_)
5103{
5104    if (__cntrl_)
5105        __cntrl_->__add_weak();
5106}
5107
5108template<class _Tp>
5109template<class _Yp>
5110inline
5111weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
5112                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5113                         _NOEXCEPT
5114    : __ptr_(__r.__ptr_),
5115      __cntrl_(__r.__cntrl_)
5116{
5117    if (__cntrl_)
5118        __cntrl_->__add_weak();
5119}
5120
5121template<class _Tp>
5122template<class _Yp>
5123inline
5124weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
5125                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5126         _NOEXCEPT
5127    : __ptr_(__r.__ptr_),
5128      __cntrl_(__r.__cntrl_)
5129{
5130    if (__cntrl_)
5131        __cntrl_->__add_weak();
5132}
5133
5134#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5135
5136template<class _Tp>
5137inline
5138weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
5139    : __ptr_(__r.__ptr_),
5140      __cntrl_(__r.__cntrl_)
5141{
5142    __r.__ptr_ = 0;
5143    __r.__cntrl_ = 0;
5144}
5145
5146template<class _Tp>
5147template<class _Yp>
5148inline
5149weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
5150                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5151         _NOEXCEPT
5152    : __ptr_(__r.__ptr_),
5153      __cntrl_(__r.__cntrl_)
5154{
5155    __r.__ptr_ = 0;
5156    __r.__cntrl_ = 0;
5157}
5158
5159#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5160
5161template<class _Tp>
5162weak_ptr<_Tp>::~weak_ptr()
5163{
5164    if (__cntrl_)
5165        __cntrl_->__release_weak();
5166}
5167
5168template<class _Tp>
5169inline
5170weak_ptr<_Tp>&
5171weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
5172{
5173    weak_ptr(__r).swap(*this);
5174    return *this;
5175}
5176
5177template<class _Tp>
5178template<class _Yp>
5179inline
5180typename enable_if
5181<
5182    is_convertible<_Yp*, _Tp*>::value,
5183    weak_ptr<_Tp>&
5184>::type
5185weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
5186{
5187    weak_ptr(__r).swap(*this);
5188    return *this;
5189}
5190
5191#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5192
5193template<class _Tp>
5194inline
5195weak_ptr<_Tp>&
5196weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
5197{
5198    weak_ptr(_VSTD::move(__r)).swap(*this);
5199    return *this;
5200}
5201
5202template<class _Tp>
5203template<class _Yp>
5204inline
5205typename enable_if
5206<
5207    is_convertible<_Yp*, _Tp*>::value,
5208    weak_ptr<_Tp>&
5209>::type
5210weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
5211{
5212    weak_ptr(_VSTD::move(__r)).swap(*this);
5213    return *this;
5214}
5215
5216#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5217
5218template<class _Tp>
5219template<class _Yp>
5220inline
5221typename enable_if
5222<
5223    is_convertible<_Yp*, _Tp*>::value,
5224    weak_ptr<_Tp>&
5225>::type
5226weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
5227{
5228    weak_ptr(__r).swap(*this);
5229    return *this;
5230}
5231
5232template<class _Tp>
5233inline
5234void
5235weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
5236{
5237    _VSTD::swap(__ptr_, __r.__ptr_);
5238    _VSTD::swap(__cntrl_, __r.__cntrl_);
5239}
5240
5241template<class _Tp>
5242inline _LIBCPP_INLINE_VISIBILITY
5243void
5244swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
5245{
5246    __x.swap(__y);
5247}
5248
5249template<class _Tp>
5250inline
5251void
5252weak_ptr<_Tp>::reset() _NOEXCEPT
5253{
5254    weak_ptr().swap(*this);
5255}
5256
5257template<class _Tp>
5258template<class _Yp>
5259shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
5260                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
5261    : __ptr_(__r.__ptr_),
5262      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
5263{
5264    if (__cntrl_ == 0)
5265        __throw_bad_weak_ptr();
5266}
5267
5268template<class _Tp>
5269shared_ptr<_Tp>
5270weak_ptr<_Tp>::lock() const _NOEXCEPT
5271{
5272    shared_ptr<_Tp> __r;
5273    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
5274    if (__r.__cntrl_)
5275        __r.__ptr_ = __ptr_;
5276    return __r;
5277}
5278
5279#if _LIBCPP_STD_VER > 14
5280template <class _Tp = void> struct owner_less;
5281#else
5282template <class _Tp> struct owner_less;
5283#endif
5284
5285template <class _Tp>
5286struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> >
5287    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
5288{
5289    typedef bool result_type;
5290    _LIBCPP_INLINE_VISIBILITY
5291    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
5292        {return __x.owner_before(__y);}
5293    _LIBCPP_INLINE_VISIBILITY
5294    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
5295        {return __x.owner_before(__y);}
5296    _LIBCPP_INLINE_VISIBILITY
5297    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
5298        {return __x.owner_before(__y);}
5299};
5300
5301template <class _Tp>
5302struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> >
5303    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
5304{
5305    typedef bool result_type;
5306    _LIBCPP_INLINE_VISIBILITY
5307    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
5308        {return __x.owner_before(__y);}
5309    _LIBCPP_INLINE_VISIBILITY
5310    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
5311        {return __x.owner_before(__y);}
5312    _LIBCPP_INLINE_VISIBILITY
5313    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
5314        {return __x.owner_before(__y);}
5315};
5316
5317#if _LIBCPP_STD_VER > 14
5318template <>
5319struct _LIBCPP_TEMPLATE_VIS owner_less<void>
5320{
5321    template <class _Tp, class _Up>
5322    _LIBCPP_INLINE_VISIBILITY
5323    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
5324        {return __x.owner_before(__y);}
5325    template <class _Tp, class _Up>
5326    _LIBCPP_INLINE_VISIBILITY
5327    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
5328        {return __x.owner_before(__y);}
5329    template <class _Tp, class _Up>
5330    _LIBCPP_INLINE_VISIBILITY
5331    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
5332        {return __x.owner_before(__y);}
5333    template <class _Tp, class _Up>
5334    _LIBCPP_INLINE_VISIBILITY
5335    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
5336        {return __x.owner_before(__y);}
5337    typedef void is_transparent;
5338};
5339#endif
5340
5341template<class _Tp>
5342class _LIBCPP_TEMPLATE_VIS enable_shared_from_this
5343{
5344    mutable weak_ptr<_Tp> __weak_this_;
5345protected:
5346    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
5347    enable_shared_from_this() _NOEXCEPT {}
5348    _LIBCPP_INLINE_VISIBILITY
5349    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
5350    _LIBCPP_INLINE_VISIBILITY
5351    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
5352        {return *this;}
5353    _LIBCPP_INLINE_VISIBILITY
5354    ~enable_shared_from_this() {}
5355public:
5356    _LIBCPP_INLINE_VISIBILITY
5357    shared_ptr<_Tp> shared_from_this()
5358        {return shared_ptr<_Tp>(__weak_this_);}
5359    _LIBCPP_INLINE_VISIBILITY
5360    shared_ptr<_Tp const> shared_from_this() const
5361        {return shared_ptr<const _Tp>(__weak_this_);}
5362
5363#if _LIBCPP_STD_VER > 14
5364    _LIBCPP_INLINE_VISIBILITY
5365    weak_ptr<_Tp> weak_from_this() _NOEXCEPT
5366       { return __weak_this_; }
5367
5368    _LIBCPP_INLINE_VISIBILITY
5369    weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT
5370        { return __weak_this_; }
5371#endif // _LIBCPP_STD_VER > 14
5372
5373    template <class _Up> friend class shared_ptr;
5374};
5375
5376template <class _Tp>
5377struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> >
5378{
5379    typedef shared_ptr<_Tp>      argument_type;
5380    typedef size_t               result_type;
5381
5382    _LIBCPP_INLINE_VISIBILITY
5383    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
5384    {
5385        return hash<_Tp*>()(__ptr.get());
5386    }
5387};
5388
5389template<class _CharT, class _Traits, class _Yp>
5390inline _LIBCPP_INLINE_VISIBILITY
5391basic_ostream<_CharT, _Traits>&
5392operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
5393
5394
5395#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
5396
5397class _LIBCPP_TYPE_VIS __sp_mut
5398{
5399    void* __lx;
5400public:
5401    void lock() _NOEXCEPT;
5402    void unlock() _NOEXCEPT;
5403
5404private:
5405    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
5406    __sp_mut(const __sp_mut&);
5407    __sp_mut& operator=(const __sp_mut&);
5408
5409    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
5410};
5411
5412_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5413__sp_mut& __get_sp_mut(const void*);
5414
5415template <class _Tp>
5416inline _LIBCPP_INLINE_VISIBILITY
5417bool
5418atomic_is_lock_free(const shared_ptr<_Tp>*)
5419{
5420    return false;
5421}
5422
5423template <class _Tp>
5424_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5425shared_ptr<_Tp>
5426atomic_load(const shared_ptr<_Tp>* __p)
5427{
5428    __sp_mut& __m = __get_sp_mut(__p);
5429    __m.lock();
5430    shared_ptr<_Tp> __q = *__p;
5431    __m.unlock();
5432    return __q;
5433}
5434
5435template <class _Tp>
5436inline _LIBCPP_INLINE_VISIBILITY
5437_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5438shared_ptr<_Tp>
5439atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
5440{
5441    return atomic_load(__p);
5442}
5443
5444template <class _Tp>
5445_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5446void
5447atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5448{
5449    __sp_mut& __m = __get_sp_mut(__p);
5450    __m.lock();
5451    __p->swap(__r);
5452    __m.unlock();
5453}
5454
5455template <class _Tp>
5456inline _LIBCPP_INLINE_VISIBILITY
5457_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5458void
5459atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5460{
5461    atomic_store(__p, __r);
5462}
5463
5464template <class _Tp>
5465_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5466shared_ptr<_Tp>
5467atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5468{
5469    __sp_mut& __m = __get_sp_mut(__p);
5470    __m.lock();
5471    __p->swap(__r);
5472    __m.unlock();
5473    return __r;
5474}
5475
5476template <class _Tp>
5477inline _LIBCPP_INLINE_VISIBILITY
5478_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5479shared_ptr<_Tp>
5480atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5481{
5482    return atomic_exchange(__p, __r);
5483}
5484
5485template <class _Tp>
5486_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5487bool
5488atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5489{
5490    shared_ptr<_Tp> __temp;
5491    __sp_mut& __m = __get_sp_mut(__p);
5492    __m.lock();
5493    if (__p->__owner_equivalent(*__v))
5494    {
5495        _VSTD::swap(__temp, *__p);
5496        *__p = __w;
5497        __m.unlock();
5498        return true;
5499    }
5500    _VSTD::swap(__temp, *__v);
5501    *__v = *__p;
5502    __m.unlock();
5503    return false;
5504}
5505
5506template <class _Tp>
5507inline _LIBCPP_INLINE_VISIBILITY
5508_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5509bool
5510atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5511{
5512    return atomic_compare_exchange_strong(__p, __v, __w);
5513}
5514
5515template <class _Tp>
5516inline _LIBCPP_INLINE_VISIBILITY
5517_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5518bool
5519atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5520                                        shared_ptr<_Tp> __w, memory_order, memory_order)
5521{
5522    return atomic_compare_exchange_strong(__p, __v, __w);
5523}
5524
5525template <class _Tp>
5526inline _LIBCPP_INLINE_VISIBILITY
5527_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5528bool
5529atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5530                                      shared_ptr<_Tp> __w, memory_order, memory_order)
5531{
5532    return atomic_compare_exchange_weak(__p, __v, __w);
5533}
5534
5535#endif  // !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
5536
5537//enum class
5538#if defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE)
5539# ifndef _LIBCPP_CXX03_LANG
5540enum class pointer_safety : unsigned char {
5541  relaxed,
5542  preferred,
5543  strict
5544};
5545# endif
5546#else
5547struct _LIBCPP_TYPE_VIS pointer_safety
5548{
5549    enum __lx
5550    {
5551        relaxed,
5552        preferred,
5553        strict
5554    };
5555
5556    __lx __v_;
5557
5558    _LIBCPP_INLINE_VISIBILITY
5559    pointer_safety() : __v_() {}
5560
5561    _LIBCPP_INLINE_VISIBILITY
5562    pointer_safety(__lx __v) : __v_(__v) {}
5563    _LIBCPP_INLINE_VISIBILITY
5564    operator int() const {return __v_;}
5565};
5566#endif
5567
5568#if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) && \
5569    defined(_LIBCPP_BUILDING_LIBRARY)
5570_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
5571#else
5572// This function is only offered in C++03 under ABI v1.
5573# if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) || !defined(_LIBCPP_CXX03_LANG)
5574inline _LIBCPP_INLINE_VISIBILITY
5575pointer_safety get_pointer_safety() _NOEXCEPT {
5576  return pointer_safety::relaxed;
5577}
5578# endif
5579#endif
5580
5581
5582_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
5583_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
5584_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
5585_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
5586
5587template <class _Tp>
5588inline _LIBCPP_INLINE_VISIBILITY
5589_Tp*
5590undeclare_reachable(_Tp* __p)
5591{
5592    return static_cast<_Tp*>(__undeclare_reachable(__p));
5593}
5594
5595_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
5596
5597// --- Helper for container swap --
5598template <typename _Alloc>
5599inline _LIBCPP_INLINE_VISIBILITY
5600void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
5601#if _LIBCPP_STD_VER >= 14
5602    _NOEXCEPT
5603#else
5604    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5605#endif
5606{
5607    __swap_allocator(__a1, __a2,
5608      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
5609}
5610
5611template <typename _Alloc>
5612_LIBCPP_INLINE_VISIBILITY
5613void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
5614#if _LIBCPP_STD_VER >= 14
5615    _NOEXCEPT
5616#else
5617    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5618#endif
5619{
5620    using _VSTD::swap;
5621    swap(__a1, __a2);
5622}
5623
5624template <typename _Alloc>
5625inline _LIBCPP_INLINE_VISIBILITY
5626void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
5627
5628template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
5629struct __noexcept_move_assign_container : public integral_constant<bool,
5630    _Traits::propagate_on_container_move_assignment::value
5631#if _LIBCPP_STD_VER > 14
5632        || _Traits::is_always_equal::value
5633#else
5634        && is_nothrow_move_assignable<_Alloc>::value
5635#endif
5636    > {};
5637
5638
5639#ifndef _LIBCPP_HAS_NO_VARIADICS
5640template <class _Tp, class _Alloc>
5641struct __temp_value {
5642    typedef allocator_traits<_Alloc> _Traits;
5643
5644    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
5645    _Alloc &__a;
5646
5647    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
5648    _Tp &   get() { return *__addr(); }
5649
5650    template<class... _Args>
5651    _LIBCPP_NO_CFI
5652    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
5653      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
5654                         _VSTD::forward<_Args>(__args)...);
5655    }
5656
5657    ~__temp_value() { _Traits::destroy(__a, __addr()); }
5658    };
5659#endif
5660
5661template<typename _Alloc, typename = void, typename = void>
5662struct __is_allocator : false_type {};
5663
5664template<typename _Alloc>
5665struct __is_allocator<_Alloc,
5666       typename __void_t<typename _Alloc::value_type>::type,
5667       typename __void_t<decltype(_VSTD::declval<_Alloc&>().allocate(size_t(0)))>::type
5668     >
5669   : true_type {};
5670
5671_LIBCPP_END_NAMESPACE_STD
5672
5673_LIBCPP_POP_MACROS
5674
5675#endif  // _LIBCPP_MEMORY
5676