xref: /llvm-project-15.0.7/libcxx/include/memory (revision d970d4d4)
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#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
666#  include <atomic>
667#endif
668#include <version>
669
670#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
671#pragma GCC system_header
672#endif
673
674_LIBCPP_PUSH_MACROS
675#include <__undef_macros>
676
677
678_LIBCPP_BEGIN_NAMESPACE_STD
679
680template <class _ValueType>
681inline _LIBCPP_INLINE_VISIBILITY
682_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
683#if !defined(_LIBCPP_HAS_NO_THREADS) && \
684    defined(__ATOMIC_RELAXED) &&        \
685    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
686    return __atomic_load_n(__value, __ATOMIC_RELAXED);
687#else
688    return *__value;
689#endif
690}
691
692template <class _ValueType>
693inline _LIBCPP_INLINE_VISIBILITY
694_ValueType __libcpp_acquire_load(_ValueType const* __value) {
695#if !defined(_LIBCPP_HAS_NO_THREADS) && \
696    defined(__ATOMIC_ACQUIRE) &&        \
697    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
698    return __atomic_load_n(__value, __ATOMIC_ACQUIRE);
699#else
700    return *__value;
701#endif
702}
703
704// addressof moved to <type_traits>
705
706template <class _Tp> class allocator;
707
708template <>
709class _LIBCPP_TEMPLATE_VIS allocator<void>
710{
711public:
712    typedef void*             pointer;
713    typedef const void*       const_pointer;
714    typedef void              value_type;
715
716    template <class _Up> struct rebind {typedef allocator<_Up> other;};
717};
718
719template <>
720class _LIBCPP_TEMPLATE_VIS allocator<const void>
721{
722public:
723    typedef const void*       pointer;
724    typedef const void*       const_pointer;
725    typedef const void        value_type;
726
727    template <class _Up> struct rebind {typedef allocator<_Up> other;};
728};
729
730// pointer_traits
731
732template <class _Tp, class = void>
733struct __has_element_type : false_type {};
734
735template <class _Tp>
736struct __has_element_type<_Tp,
737              typename __void_t<typename _Tp::element_type>::type> : true_type {};
738
739template <class _Ptr, bool = __has_element_type<_Ptr>::value>
740struct __pointer_traits_element_type;
741
742template <class _Ptr>
743struct __pointer_traits_element_type<_Ptr, true>
744{
745    typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::element_type type;
746};
747
748#ifndef _LIBCPP_HAS_NO_VARIADICS
749
750template <template <class, class...> class _Sp, class _Tp, class ..._Args>
751struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
752{
753    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::element_type type;
754};
755
756template <template <class, class...> class _Sp, class _Tp, class ..._Args>
757struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
758{
759    typedef _LIBCPP_NODEBUG_TYPE _Tp type;
760};
761
762#else  // _LIBCPP_HAS_NO_VARIADICS
763
764template <template <class> class _Sp, class _Tp>
765struct __pointer_traits_element_type<_Sp<_Tp>, true>
766{
767    typedef typename _Sp<_Tp>::element_type type;
768};
769
770template <template <class> class _Sp, class _Tp>
771struct __pointer_traits_element_type<_Sp<_Tp>, false>
772{
773    typedef _Tp type;
774};
775
776template <template <class, class> class _Sp, class _Tp, class _A0>
777struct __pointer_traits_element_type<_Sp<_Tp, _A0>, true>
778{
779    typedef typename _Sp<_Tp, _A0>::element_type type;
780};
781
782template <template <class, class> class _Sp, class _Tp, class _A0>
783struct __pointer_traits_element_type<_Sp<_Tp, _A0>, false>
784{
785    typedef _Tp type;
786};
787
788template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
789struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, true>
790{
791    typedef typename _Sp<_Tp, _A0, _A1>::element_type type;
792};
793
794template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
795struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, false>
796{
797    typedef _Tp type;
798};
799
800template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
801                                                           class _A1, class _A2>
802struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, true>
803{
804    typedef typename _Sp<_Tp, _A0, _A1, _A2>::element_type type;
805};
806
807template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
808                                                           class _A1, class _A2>
809struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, false>
810{
811    typedef _Tp type;
812};
813
814#endif  // _LIBCPP_HAS_NO_VARIADICS
815
816template <class _Tp, class = void>
817struct __has_difference_type : false_type {};
818
819template <class _Tp>
820struct __has_difference_type<_Tp,
821            typename __void_t<typename _Tp::difference_type>::type> : true_type {};
822
823template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
824struct __pointer_traits_difference_type
825{
826    typedef _LIBCPP_NODEBUG_TYPE ptrdiff_t type;
827};
828
829template <class _Ptr>
830struct __pointer_traits_difference_type<_Ptr, true>
831{
832    typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::difference_type type;
833};
834
835template <class _Tp, class _Up>
836struct __has_rebind
837{
838private:
839    struct __two {char __lx; char __lxx;};
840    template <class _Xp> static __two __test(...);
841    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
842public:
843    static const bool value = sizeof(__test<_Tp>(0)) == 1;
844};
845
846template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
847struct __pointer_traits_rebind
848{
849#ifndef _LIBCPP_CXX03_LANG
850    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up> type;
851#else
852    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up>::other type;
853#endif
854};
855
856#ifndef _LIBCPP_HAS_NO_VARIADICS
857
858template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
859struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
860{
861#ifndef _LIBCPP_CXX03_LANG
862    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
863#else
864    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
865#endif
866};
867
868template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
869struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
870{
871    typedef _Sp<_Up, _Args...> type;
872};
873
874#else  // _LIBCPP_HAS_NO_VARIADICS
875
876template <template <class> class _Sp, class _Tp, class _Up>
877struct __pointer_traits_rebind<_Sp<_Tp>, _Up, true>
878{
879#ifndef _LIBCPP_CXX03_LANG
880    typedef typename _Sp<_Tp>::template rebind<_Up> type;
881#else
882    typedef typename _Sp<_Tp>::template rebind<_Up>::other type;
883#endif
884};
885
886template <template <class> class _Sp, class _Tp, class _Up>
887struct __pointer_traits_rebind<_Sp<_Tp>, _Up, false>
888{
889    typedef _Sp<_Up> type;
890};
891
892template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
893struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, true>
894{
895#ifndef _LIBCPP_CXX03_LANG
896    typedef typename _Sp<_Tp, _A0>::template rebind<_Up> type;
897#else
898    typedef typename _Sp<_Tp, _A0>::template rebind<_Up>::other type;
899#endif
900};
901
902template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
903struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, false>
904{
905    typedef _Sp<_Up, _A0> type;
906};
907
908template <template <class, class, class> class _Sp, class _Tp, class _A0,
909                                         class _A1, class _Up>
910struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, true>
911{
912#ifndef _LIBCPP_CXX03_LANG
913    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up> type;
914#else
915    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up>::other type;
916#endif
917};
918
919template <template <class, class, class> class _Sp, class _Tp, class _A0,
920                                         class _A1, class _Up>
921struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, false>
922{
923    typedef _Sp<_Up, _A0, _A1> type;
924};
925
926template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
927                                                class _A1, class _A2, class _Up>
928struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, true>
929{
930#ifndef _LIBCPP_CXX03_LANG
931    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up> type;
932#else
933    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
934#endif
935};
936
937template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
938                                                class _A1, class _A2, class _Up>
939struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, false>
940{
941    typedef _Sp<_Up, _A0, _A1, _A2> type;
942};
943
944#endif  // _LIBCPP_HAS_NO_VARIADICS
945
946template <class _Ptr>
947struct _LIBCPP_TEMPLATE_VIS pointer_traits
948{
949    typedef _Ptr                                                     pointer;
950    typedef typename __pointer_traits_element_type<pointer>::type    element_type;
951    typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
952
953#ifndef _LIBCPP_CXX03_LANG
954    template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
955#else
956    template <class _Up> struct rebind
957        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
958#endif  // _LIBCPP_CXX03_LANG
959
960private:
961    struct __nat {};
962public:
963    _LIBCPP_INLINE_VISIBILITY
964    static pointer pointer_to(typename conditional<is_void<element_type>::value,
965                                           __nat, element_type>::type& __r)
966        {return pointer::pointer_to(__r);}
967};
968
969template <class _Tp>
970struct _LIBCPP_TEMPLATE_VIS pointer_traits<_Tp*>
971{
972    typedef _Tp*      pointer;
973    typedef _Tp       element_type;
974    typedef ptrdiff_t difference_type;
975
976#ifndef _LIBCPP_CXX03_LANG
977    template <class _Up> using rebind = _Up*;
978#else
979    template <class _Up> struct rebind {typedef _Up* other;};
980#endif
981
982private:
983    struct __nat {};
984public:
985    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
986    static pointer pointer_to(typename conditional<is_void<element_type>::value,
987                                      __nat, element_type>::type& __r) _NOEXCEPT
988        {return _VSTD::addressof(__r);}
989};
990
991template <class _From, class _To>
992struct __rebind_pointer {
993#ifndef _LIBCPP_CXX03_LANG
994    typedef typename pointer_traits<_From>::template rebind<_To>        type;
995#else
996    typedef typename pointer_traits<_From>::template rebind<_To>::other type;
997#endif
998};
999
1000// allocator_traits
1001
1002template <class _Tp, class = void>
1003struct __has_pointer_type : false_type {};
1004
1005template <class _Tp>
1006struct __has_pointer_type<_Tp,
1007          typename __void_t<typename _Tp::pointer>::type> : true_type {};
1008
1009namespace __pointer_type_imp
1010{
1011
1012template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
1013struct __pointer_type
1014{
1015    typedef _LIBCPP_NODEBUG_TYPE typename _Dp::pointer type;
1016};
1017
1018template <class _Tp, class _Dp>
1019struct __pointer_type<_Tp, _Dp, false>
1020{
1021    typedef _LIBCPP_NODEBUG_TYPE _Tp* type;
1022};
1023
1024}  // __pointer_type_imp
1025
1026template <class _Tp, class _Dp>
1027struct __pointer_type
1028{
1029    typedef _LIBCPP_NODEBUG_TYPE typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
1030};
1031
1032template <class _Tp, class = void>
1033struct __has_const_pointer : false_type {};
1034
1035template <class _Tp>
1036struct __has_const_pointer<_Tp,
1037            typename __void_t<typename _Tp::const_pointer>::type> : true_type {};
1038
1039template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
1040struct __const_pointer
1041{
1042    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::const_pointer type;
1043};
1044
1045template <class _Tp, class _Ptr, class _Alloc>
1046struct __const_pointer<_Tp, _Ptr, _Alloc, false>
1047{
1048#ifndef _LIBCPP_CXX03_LANG
1049    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
1050#else
1051    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
1052#endif
1053};
1054
1055template <class _Tp, class = void>
1056struct __has_void_pointer : false_type {};
1057
1058template <class _Tp>
1059struct __has_void_pointer<_Tp,
1060               typename __void_t<typename _Tp::void_pointer>::type> : true_type {};
1061
1062template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
1063struct __void_pointer
1064{
1065    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::void_pointer type;
1066};
1067
1068template <class _Ptr, class _Alloc>
1069struct __void_pointer<_Ptr, _Alloc, false>
1070{
1071#ifndef _LIBCPP_CXX03_LANG
1072    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<void> type;
1073#else
1074    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<void>::other type;
1075#endif
1076};
1077
1078template <class _Tp, class = void>
1079struct __has_const_void_pointer : false_type {};
1080
1081template <class _Tp>
1082struct __has_const_void_pointer<_Tp,
1083            typename __void_t<typename _Tp::const_void_pointer>::type> : true_type {};
1084
1085template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
1086struct __const_void_pointer
1087{
1088    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::const_void_pointer type;
1089};
1090
1091template <class _Ptr, class _Alloc>
1092struct __const_void_pointer<_Ptr, _Alloc, false>
1093{
1094#ifndef _LIBCPP_CXX03_LANG
1095    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const void> type;
1096#else
1097    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const void>::other type;
1098#endif
1099};
1100
1101
1102template <bool _UsePointerTraits> struct __to_address_helper;
1103
1104template <> struct __to_address_helper<true> {
1105    template <class _Pointer>
1106    using __return_type = decltype(pointer_traits<_Pointer>::to_address(std::declval<const _Pointer&>()));
1107
1108    template <class _Pointer>
1109    _LIBCPP_CONSTEXPR
1110    static __return_type<_Pointer>
1111    __do_it(const _Pointer &__p) _NOEXCEPT { return pointer_traits<_Pointer>::to_address(__p); }
1112};
1113
1114template <class _Pointer, bool _Dummy = true>
1115using __choose_to_address = __to_address_helper<_IsValidExpansion<__to_address_helper<_Dummy>::template __return_type, _Pointer>::value>;
1116
1117
1118template <class _Tp>
1119inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1120_Tp*
1121__to_address(_Tp* __p) _NOEXCEPT
1122{
1123    static_assert(!is_function<_Tp>::value, "_Tp is a function type");
1124    return __p;
1125}
1126
1127template <class _Pointer>
1128inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1129typename __choose_to_address<_Pointer>::template __return_type<_Pointer>
1130__to_address(const _Pointer& __p) _NOEXCEPT {
1131  return __choose_to_address<_Pointer>::__do_it(__p);
1132}
1133
1134template <> struct __to_address_helper<false> {
1135    template <class _Pointer>
1136    using __return_type = typename pointer_traits<_Pointer>::element_type*;
1137
1138    template <class _Pointer>
1139    _LIBCPP_CONSTEXPR
1140    static __return_type<_Pointer>
1141    __do_it(const _Pointer &__p) _NOEXCEPT { return std::__to_address(__p.operator->()); }
1142};
1143
1144
1145#if _LIBCPP_STD_VER > 17
1146template <class _Tp>
1147inline _LIBCPP_INLINE_VISIBILITY constexpr
1148_Tp*
1149to_address(_Tp* __p) _NOEXCEPT
1150{
1151    static_assert(!is_function_v<_Tp>, "_Tp is a function type");
1152    return __p;
1153}
1154
1155template <class _Pointer>
1156inline _LIBCPP_INLINE_VISIBILITY
1157auto
1158to_address(const _Pointer& __p) _NOEXCEPT
1159{
1160    return _VSTD::__to_address(__p);
1161}
1162#endif
1163
1164template <class _Tp, class = void>
1165struct __has_size_type : false_type {};
1166
1167template <class _Tp>
1168struct __has_size_type<_Tp,
1169               typename __void_t<typename _Tp::size_type>::type> : true_type {};
1170
1171template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
1172struct __size_type
1173{
1174    typedef _LIBCPP_NODEBUG_TYPE typename make_unsigned<_DiffType>::type type;
1175};
1176
1177template <class _Alloc, class _DiffType>
1178struct __size_type<_Alloc, _DiffType, true>
1179{
1180    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::size_type type;
1181};
1182
1183template <class _Tp, class = void>
1184struct __has_propagate_on_container_copy_assignment : false_type {};
1185
1186template <class _Tp>
1187struct __has_propagate_on_container_copy_assignment<_Tp,
1188    typename __void_t<typename _Tp::propagate_on_container_copy_assignment>::type>
1189        : true_type {};
1190
1191template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
1192struct __propagate_on_container_copy_assignment
1193{
1194    typedef _LIBCPP_NODEBUG_TYPE false_type type;
1195};
1196
1197template <class _Alloc>
1198struct __propagate_on_container_copy_assignment<_Alloc, true>
1199{
1200    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_copy_assignment type;
1201};
1202
1203template <class _Tp, class = void>
1204struct __has_propagate_on_container_move_assignment : false_type {};
1205
1206template <class _Tp>
1207struct __has_propagate_on_container_move_assignment<_Tp,
1208           typename __void_t<typename _Tp::propagate_on_container_move_assignment>::type>
1209               : true_type {};
1210
1211template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
1212struct __propagate_on_container_move_assignment
1213{
1214    typedef false_type type;
1215};
1216
1217template <class _Alloc>
1218struct __propagate_on_container_move_assignment<_Alloc, true>
1219{
1220    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_move_assignment type;
1221};
1222
1223template <class _Tp, class = void>
1224struct __has_propagate_on_container_swap : false_type {};
1225
1226template <class _Tp>
1227struct __has_propagate_on_container_swap<_Tp,
1228           typename __void_t<typename _Tp::propagate_on_container_swap>::type>
1229               : true_type {};
1230
1231template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
1232struct __propagate_on_container_swap
1233{
1234    typedef false_type type;
1235};
1236
1237template <class _Alloc>
1238struct __propagate_on_container_swap<_Alloc, true>
1239{
1240    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_swap type;
1241};
1242
1243template <class _Tp, class = void>
1244struct __has_is_always_equal : false_type {};
1245
1246template <class _Tp>
1247struct __has_is_always_equal<_Tp,
1248           typename __void_t<typename _Tp::is_always_equal>::type>
1249               : true_type {};
1250
1251template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
1252struct __is_always_equal
1253{
1254    typedef _LIBCPP_NODEBUG_TYPE typename _VSTD::is_empty<_Alloc>::type type;
1255};
1256
1257template <class _Alloc>
1258struct __is_always_equal<_Alloc, true>
1259{
1260    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::is_always_equal type;
1261};
1262
1263template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
1264struct __has_rebind_other
1265{
1266private:
1267    struct __two {char __lx; char __lxx;};
1268    template <class _Xp> static __two __test(...);
1269    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
1270public:
1271    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1272};
1273
1274template <class _Tp, class _Up>
1275struct __has_rebind_other<_Tp, _Up, false>
1276{
1277    static const bool value = false;
1278};
1279
1280template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
1281struct __allocator_traits_rebind
1282{
1283    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up>::other type;
1284};
1285
1286#ifndef _LIBCPP_HAS_NO_VARIADICS
1287
1288template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1289struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
1290{
1291    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
1292};
1293
1294template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1295struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
1296{
1297    typedef _LIBCPP_NODEBUG_TYPE _Alloc<_Up, _Args...> type;
1298};
1299
1300#else  // _LIBCPP_HAS_NO_VARIADICS
1301
1302template <template <class> class _Alloc, class _Tp, class _Up>
1303struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, true>
1304{
1305    typedef typename _Alloc<_Tp>::template rebind<_Up>::other type;
1306};
1307
1308template <template <class> class _Alloc, class _Tp, class _Up>
1309struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, false>
1310{
1311    typedef _Alloc<_Up> type;
1312};
1313
1314template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1315struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, true>
1316{
1317    typedef typename _Alloc<_Tp, _A0>::template rebind<_Up>::other type;
1318};
1319
1320template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1321struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, false>
1322{
1323    typedef _Alloc<_Up, _A0> type;
1324};
1325
1326template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1327                                         class _A1, class _Up>
1328struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, true>
1329{
1330    typedef typename _Alloc<_Tp, _A0, _A1>::template rebind<_Up>::other type;
1331};
1332
1333template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1334                                         class _A1, class _Up>
1335struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, false>
1336{
1337    typedef _Alloc<_Up, _A0, _A1> type;
1338};
1339
1340template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1341                                                class _A1, class _A2, class _Up>
1342struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, true>
1343{
1344    typedef typename _Alloc<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
1345};
1346
1347template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1348                                                class _A1, class _A2, class _Up>
1349struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, false>
1350{
1351    typedef _Alloc<_Up, _A0, _A1, _A2> type;
1352};
1353
1354#endif  // _LIBCPP_HAS_NO_VARIADICS
1355
1356#ifndef _LIBCPP_CXX03_LANG
1357
1358template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1359auto
1360__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1361    -> decltype((void)__a.allocate(__sz, __p), true_type());
1362
1363template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1364auto
1365__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1366    -> false_type;
1367
1368template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1369struct __has_allocate_hint
1370    : integral_constant<bool,
1371        is_same<
1372            decltype(_VSTD::__has_allocate_hint_test(declval<_Alloc>(),
1373                                          declval<_SizeType>(),
1374                                          declval<_ConstVoidPtr>())),
1375            true_type>::value>
1376{
1377};
1378
1379#else  // _LIBCPP_CXX03_LANG
1380
1381template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1382struct __has_allocate_hint
1383    : true_type
1384{
1385};
1386
1387#endif  // _LIBCPP_CXX03_LANG
1388
1389#if !defined(_LIBCPP_CXX03_LANG)
1390
1391template <class _Alloc, class _Tp, class ..._Args>
1392decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Tp*>(),
1393                                           _VSTD::declval<_Args>()...),
1394                                           true_type())
1395__has_construct_test(_Alloc&& __a, _Tp* __p, _Args&& ...__args);
1396
1397template <class _Alloc, class _Pointer, class ..._Args>
1398false_type
1399__has_construct_test(const _Alloc& __a, _Pointer&& __p, _Args&& ...__args);
1400
1401template <class _Alloc, class _Pointer, class ..._Args>
1402struct __has_construct
1403    : integral_constant<bool,
1404        is_same<
1405            decltype(_VSTD::__has_construct_test(declval<_Alloc>(),
1406                                          declval<_Pointer>(),
1407                                          declval<_Args>()...)),
1408            true_type>::value>
1409{
1410};
1411
1412template <class _Alloc, class _Pointer>
1413auto
1414__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
1415    -> decltype(__a.destroy(__p), true_type());
1416
1417template <class _Alloc, class _Pointer>
1418auto
1419__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
1420    -> false_type;
1421
1422template <class _Alloc, class _Pointer>
1423struct __has_destroy
1424    : integral_constant<bool,
1425        is_same<
1426            decltype(_VSTD::__has_destroy_test(declval<_Alloc>(),
1427                                        declval<_Pointer>())),
1428            true_type>::value>
1429{
1430};
1431
1432template <class _Alloc>
1433auto
1434__has_max_size_test(_Alloc&& __a)
1435    -> decltype(__a.max_size(), true_type());
1436
1437template <class _Alloc>
1438auto
1439__has_max_size_test(const volatile _Alloc& __a)
1440    -> false_type;
1441
1442template <class _Alloc>
1443struct __has_max_size
1444    : integral_constant<bool,
1445        is_same<
1446            decltype(_VSTD::__has_max_size_test(declval<_Alloc&>())),
1447            true_type>::value>
1448{
1449};
1450
1451template <class _Alloc>
1452auto
1453__has_select_on_container_copy_construction_test(_Alloc&& __a)
1454    -> decltype(__a.select_on_container_copy_construction(), true_type());
1455
1456template <class _Alloc>
1457auto
1458__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
1459    -> false_type;
1460
1461template <class _Alloc>
1462struct __has_select_on_container_copy_construction
1463    : integral_constant<bool,
1464        is_same<
1465            decltype(_VSTD::__has_select_on_container_copy_construction_test(declval<_Alloc&>())),
1466            true_type>::value>
1467{
1468};
1469
1470#else  // _LIBCPP_CXX03_LANG
1471
1472template <class _Alloc, class _Pointer, class _Tp, class = void>
1473struct __has_construct : std::false_type {};
1474
1475template <class _Alloc, class _Pointer, class _Tp>
1476struct __has_construct<_Alloc, _Pointer, _Tp, typename __void_t<
1477    decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Pointer>(), _VSTD::declval<_Tp>()))
1478>::type> : std::true_type {};
1479
1480template <class _Alloc, class _Pointer, class = void>
1481struct __has_destroy : false_type {};
1482
1483template <class _Alloc, class _Pointer>
1484struct __has_destroy<_Alloc, _Pointer, typename __void_t<
1485    decltype(_VSTD::declval<_Alloc>().destroy(_VSTD::declval<_Pointer>()))
1486>::type> : std::true_type {};
1487
1488template <class _Alloc>
1489struct __has_max_size
1490    : true_type
1491{
1492};
1493
1494template <class _Alloc>
1495struct __has_select_on_container_copy_construction
1496    : false_type
1497{
1498};
1499
1500#endif  // _LIBCPP_CXX03_LANG
1501
1502template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
1503struct __alloc_traits_difference_type
1504{
1505    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::difference_type type;
1506};
1507
1508template <class _Alloc, class _Ptr>
1509struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
1510{
1511    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::difference_type type;
1512};
1513
1514template <class _Tp>
1515struct __is_default_allocator : false_type {};
1516
1517template <class _Tp>
1518struct __is_default_allocator<_VSTD::allocator<_Tp> > : true_type {};
1519
1520
1521
1522template <class _Alloc,
1523    bool = __has_construct<_Alloc, typename _Alloc::value_type*,  typename _Alloc::value_type&&>::value && !__is_default_allocator<_Alloc>::value
1524    >
1525struct __is_cpp17_move_insertable;
1526template <class _Alloc>
1527struct __is_cpp17_move_insertable<_Alloc, true> : std::true_type {};
1528template <class _Alloc>
1529struct __is_cpp17_move_insertable<_Alloc, false> : std::is_move_constructible<typename _Alloc::value_type> {};
1530
1531template <class _Alloc,
1532    bool = __has_construct<_Alloc, typename _Alloc::value_type*, const typename _Alloc::value_type&>::value && !__is_default_allocator<_Alloc>::value
1533    >
1534struct __is_cpp17_copy_insertable;
1535template <class _Alloc>
1536struct __is_cpp17_copy_insertable<_Alloc, true> : __is_cpp17_move_insertable<_Alloc> {};
1537template <class _Alloc>
1538struct __is_cpp17_copy_insertable<_Alloc, false> : integral_constant<bool,
1539    std::is_copy_constructible<typename _Alloc::value_type>::value &&
1540    __is_cpp17_move_insertable<_Alloc>::value>
1541  {};
1542
1543
1544
1545template <class _Alloc>
1546struct _LIBCPP_TEMPLATE_VIS allocator_traits
1547{
1548    typedef _Alloc                              allocator_type;
1549    typedef typename allocator_type::value_type value_type;
1550
1551    typedef typename __pointer_type<value_type, allocator_type>::type pointer;
1552    typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
1553    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
1554    typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;
1555
1556    typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
1557    typedef typename __size_type<allocator_type, difference_type>::type size_type;
1558
1559    typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
1560                     propagate_on_container_copy_assignment;
1561    typedef typename __propagate_on_container_move_assignment<allocator_type>::type
1562                     propagate_on_container_move_assignment;
1563    typedef typename __propagate_on_container_swap<allocator_type>::type
1564                     propagate_on_container_swap;
1565    typedef typename __is_always_equal<allocator_type>::type
1566                     is_always_equal;
1567
1568#ifndef _LIBCPP_CXX03_LANG
1569    template <class _Tp> using rebind_alloc =
1570                  typename __allocator_traits_rebind<allocator_type, _Tp>::type;
1571    template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp> >;
1572#else  // _LIBCPP_CXX03_LANG
1573    template <class _Tp> struct rebind_alloc
1574        {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
1575    template <class _Tp> struct rebind_traits
1576        {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
1577#endif  // _LIBCPP_CXX03_LANG
1578
1579    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1580    static pointer allocate(allocator_type& __a, size_type __n)
1581        {return __a.allocate(__n);}
1582    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1583    static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
1584        {return __allocate(__a, __n, __hint,
1585            __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}
1586
1587    _LIBCPP_INLINE_VISIBILITY
1588    static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
1589        {__a.deallocate(__p, __n);}
1590
1591#ifndef _LIBCPP_HAS_NO_VARIADICS
1592    template <class _Tp, class... _Args>
1593        _LIBCPP_INLINE_VISIBILITY
1594        static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
1595            {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
1596                         __a, __p, _VSTD::forward<_Args>(__args)...);}
1597#else  // _LIBCPP_HAS_NO_VARIADICS
1598    template <class _Tp>
1599        _LIBCPP_INLINE_VISIBILITY
1600        static void construct(allocator_type&, _Tp* __p)
1601            {
1602                ::new ((void*)__p) _Tp();
1603            }
1604    template <class _Tp, class _A0>
1605        _LIBCPP_INLINE_VISIBILITY
1606        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0)
1607            {
1608                __construct(__has_construct<allocator_type, _Tp*, const _A0&>(),
1609                            __a, __p, __a0);
1610            }
1611    template <class _Tp, class _A0, class _A1>
1612        _LIBCPP_INLINE_VISIBILITY
1613        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
1614                              const _A1& __a1)
1615            {
1616                ::new ((void*)__p) _Tp(__a0, __a1);
1617            }
1618    template <class _Tp, class _A0, class _A1, class _A2>
1619        _LIBCPP_INLINE_VISIBILITY
1620        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
1621                              const _A1& __a1, const _A2& __a2)
1622            {
1623                ::new ((void*)__p) _Tp(__a0, __a1, __a2);
1624            }
1625#endif  // _LIBCPP_HAS_NO_VARIADICS
1626
1627    template <class _Tp>
1628        _LIBCPP_INLINE_VISIBILITY
1629        static void destroy(allocator_type& __a, _Tp* __p)
1630            {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}
1631
1632    _LIBCPP_INLINE_VISIBILITY
1633    static size_type max_size(const allocator_type& __a) _NOEXCEPT
1634        {return __max_size(__has_max_size<const allocator_type>(), __a);}
1635
1636    _LIBCPP_INLINE_VISIBILITY
1637    static allocator_type
1638        select_on_container_copy_construction(const allocator_type& __a)
1639            {return __select_on_container_copy_construction(
1640                __has_select_on_container_copy_construction<const allocator_type>(),
1641                __a);}
1642
1643    template <class _Ptr>
1644        _LIBCPP_INLINE_VISIBILITY
1645        static
1646        void
1647        __construct_forward_with_exception_guarantees(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
1648        {
1649            static_assert(__is_cpp17_move_insertable<allocator_type>::value,
1650              "The specified type does not meet the requirements of Cpp17MoveInsertible");
1651            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1652              construct(__a, _VSTD::__to_address(__begin2),
1653#ifdef _LIBCPP_NO_EXCEPTIONS
1654                        _VSTD::move(*__begin1)
1655#else
1656                        _VSTD::move_if_noexcept(*__begin1)
1657#endif
1658                        );
1659        }
1660
1661    template <class _Tp>
1662        _LIBCPP_INLINE_VISIBILITY
1663        static
1664        typename enable_if
1665        <
1666            (__is_default_allocator<allocator_type>::value
1667                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1668             is_trivially_move_constructible<_Tp>::value,
1669            void
1670        >::type
1671        __construct_forward_with_exception_guarantees(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
1672        {
1673            ptrdiff_t _Np = __end1 - __begin1;
1674            if (_Np > 0)
1675            {
1676                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
1677                __begin2 += _Np;
1678            }
1679        }
1680
1681    template <class _Iter, class _Ptr>
1682        _LIBCPP_INLINE_VISIBILITY
1683        static
1684        void
1685        __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
1686        {
1687            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1688                construct(__a, _VSTD::__to_address(__begin2), *__begin1);
1689        }
1690
1691    template <class _SourceTp, class _DestTp,
1692              class _RawSourceTp = typename remove_const<_SourceTp>::type,
1693              class _RawDestTp = typename remove_const<_DestTp>::type>
1694        _LIBCPP_INLINE_VISIBILITY
1695        static
1696        typename enable_if
1697        <
1698            is_trivially_move_constructible<_DestTp>::value &&
1699            is_same<_RawSourceTp, _RawDestTp>::value &&
1700            (__is_default_allocator<allocator_type>::value ||
1701             !__has_construct<allocator_type, _DestTp*, _SourceTp&>::value),
1702            void
1703        >::type
1704        __construct_range_forward(allocator_type&, _SourceTp* __begin1, _SourceTp* __end1, _DestTp*& __begin2)
1705        {
1706            ptrdiff_t _Np = __end1 - __begin1;
1707            if (_Np > 0)
1708            {
1709                _VSTD::memcpy(const_cast<_RawDestTp*>(__begin2), __begin1, _Np * sizeof(_DestTp));
1710                __begin2 += _Np;
1711            }
1712        }
1713
1714    template <class _Ptr>
1715        _LIBCPP_INLINE_VISIBILITY
1716        static
1717        void
1718        __construct_backward_with_exception_guarantees(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
1719        {
1720            static_assert(__is_cpp17_move_insertable<allocator_type>::value,
1721              "The specified type does not meet the requirements of Cpp17MoveInsertable");
1722            while (__end1 != __begin1)
1723            {
1724              construct(__a, _VSTD::__to_address(__end2 - 1),
1725#ifdef _LIBCPP_NO_EXCEPTIONS
1726                        _VSTD::move(*--__end1)
1727#else
1728                        _VSTD::move_if_noexcept(*--__end1)
1729#endif
1730                        );
1731              --__end2;
1732            }
1733        }
1734
1735    template <class _Tp>
1736        _LIBCPP_INLINE_VISIBILITY
1737        static
1738        typename enable_if
1739        <
1740            (__is_default_allocator<allocator_type>::value
1741                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1742             is_trivially_move_constructible<_Tp>::value,
1743            void
1744        >::type
1745        __construct_backward_with_exception_guarantees(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
1746        {
1747            ptrdiff_t _Np = __end1 - __begin1;
1748            __end2 -= _Np;
1749            if (_Np > 0)
1750                _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
1751        }
1752
1753private:
1754
1755    _LIBCPP_INLINE_VISIBILITY
1756    static pointer __allocate(allocator_type& __a, size_type __n,
1757        const_void_pointer __hint, true_type)
1758        {return __a.allocate(__n, __hint);}
1759    _LIBCPP_INLINE_VISIBILITY
1760    static pointer __allocate(allocator_type& __a, size_type __n,
1761        const_void_pointer, false_type)
1762        {return __a.allocate(__n);}
1763
1764#ifndef _LIBCPP_HAS_NO_VARIADICS
1765    template <class _Tp, class... _Args>
1766        _LIBCPP_INLINE_VISIBILITY
1767        static void __construct(true_type, allocator_type& __a, _Tp* __p, _Args&&... __args)
1768            {__a.construct(__p, _VSTD::forward<_Args>(__args)...);}
1769    template <class _Tp, class... _Args>
1770        _LIBCPP_INLINE_VISIBILITY
1771        static void __construct(false_type, allocator_type&, _Tp* __p, _Args&&... __args)
1772            {
1773                ::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
1774            }
1775#else  // _LIBCPP_HAS_NO_VARIADICS
1776    template <class _Tp, class _A0>
1777        _LIBCPP_INLINE_VISIBILITY
1778        static void __construct(true_type, allocator_type& __a, _Tp* __p,
1779                                const _A0& __a0)
1780            {__a.construct(__p, __a0);}
1781    template <class _Tp, class _A0>
1782        _LIBCPP_INLINE_VISIBILITY
1783        static void __construct(false_type, allocator_type&, _Tp* __p,
1784                                const _A0& __a0)
1785            {
1786                ::new ((void*)__p) _Tp(__a0);
1787            }
1788#endif  // _LIBCPP_HAS_NO_VARIADICS
1789
1790    template <class _Tp>
1791        _LIBCPP_INLINE_VISIBILITY
1792        static void __destroy(true_type, allocator_type& __a, _Tp* __p)
1793            {__a.destroy(__p);}
1794    template <class _Tp>
1795        _LIBCPP_INLINE_VISIBILITY
1796        static void __destroy(false_type, allocator_type&, _Tp* __p)
1797            {
1798                __p->~_Tp();
1799            }
1800
1801    _LIBCPP_INLINE_VISIBILITY
1802    static size_type __max_size(true_type, const allocator_type& __a) _NOEXCEPT
1803            {return __a.max_size();}
1804    _LIBCPP_INLINE_VISIBILITY
1805    static size_type __max_size(false_type, const allocator_type&) _NOEXCEPT
1806            {return numeric_limits<size_type>::max() / sizeof(value_type);}
1807
1808    _LIBCPP_INLINE_VISIBILITY
1809    static allocator_type
1810        __select_on_container_copy_construction(true_type, const allocator_type& __a)
1811            {return __a.select_on_container_copy_construction();}
1812    _LIBCPP_INLINE_VISIBILITY
1813    static allocator_type
1814        __select_on_container_copy_construction(false_type, const allocator_type& __a)
1815            {return __a;}
1816};
1817
1818template <class _Traits, class _Tp>
1819struct __rebind_alloc_helper
1820{
1821#ifndef _LIBCPP_CXX03_LANG
1822    typedef _LIBCPP_NODEBUG_TYPE typename _Traits::template rebind_alloc<_Tp>        type;
1823#else
1824    typedef typename _Traits::template rebind_alloc<_Tp>::other type;
1825#endif
1826};
1827
1828// allocator
1829
1830template <class _Tp>
1831class _LIBCPP_TEMPLATE_VIS allocator
1832{
1833public:
1834    typedef size_t            size_type;
1835    typedef ptrdiff_t         difference_type;
1836    typedef _Tp*              pointer;
1837    typedef const _Tp*        const_pointer;
1838    typedef _Tp&              reference;
1839    typedef const _Tp&        const_reference;
1840    typedef _Tp               value_type;
1841
1842    typedef true_type propagate_on_container_move_assignment;
1843    typedef true_type is_always_equal;
1844
1845    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1846
1847    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1848    allocator() _NOEXCEPT {}
1849
1850    template <class _Up>
1851    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1852    allocator(const allocator<_Up>&) _NOEXCEPT {}
1853
1854    _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
1855        {return _VSTD::addressof(__x);}
1856    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1857        {return _VSTD::addressof(__x);}
1858    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1859    pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1860        {
1861        if (__n > max_size())
1862            __throw_length_error("allocator<T>::allocate(size_t n)"
1863                                 " 'n' exceeds maximum supported size");
1864        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1865        }
1866    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
1867        {_VSTD::__libcpp_deallocate((void*)__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
1868    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1869        {return size_type(~0) / sizeof(_Tp);}
1870#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1871    template <class _Up, class... _Args>
1872        _LIBCPP_INLINE_VISIBILITY
1873        void
1874        construct(_Up* __p, _Args&&... __args)
1875        {
1876            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1877        }
1878#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1879        _LIBCPP_INLINE_VISIBILITY
1880        void
1881        construct(pointer __p)
1882        {
1883            ::new((void*)__p) _Tp();
1884        }
1885# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1886
1887    template <class _A0>
1888        _LIBCPP_INLINE_VISIBILITY
1889        void
1890        construct(pointer __p, _A0& __a0)
1891        {
1892            ::new((void*)__p) _Tp(__a0);
1893        }
1894    template <class _A0>
1895        _LIBCPP_INLINE_VISIBILITY
1896        void
1897        construct(pointer __p, const _A0& __a0)
1898        {
1899            ::new((void*)__p) _Tp(__a0);
1900        }
1901# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1902    template <class _A0, class _A1>
1903        _LIBCPP_INLINE_VISIBILITY
1904        void
1905        construct(pointer __p, _A0& __a0, _A1& __a1)
1906        {
1907            ::new((void*)__p) _Tp(__a0, __a1);
1908        }
1909    template <class _A0, class _A1>
1910        _LIBCPP_INLINE_VISIBILITY
1911        void
1912        construct(pointer __p, const _A0& __a0, _A1& __a1)
1913        {
1914            ::new((void*)__p) _Tp(__a0, __a1);
1915        }
1916    template <class _A0, class _A1>
1917        _LIBCPP_INLINE_VISIBILITY
1918        void
1919        construct(pointer __p, _A0& __a0, const _A1& __a1)
1920        {
1921            ::new((void*)__p) _Tp(__a0, __a1);
1922        }
1923    template <class _A0, class _A1>
1924        _LIBCPP_INLINE_VISIBILITY
1925        void
1926        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1927        {
1928            ::new((void*)__p) _Tp(__a0, __a1);
1929        }
1930#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1931    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1932};
1933
1934template <class _Tp>
1935class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
1936{
1937public:
1938    typedef size_t            size_type;
1939    typedef ptrdiff_t         difference_type;
1940    typedef const _Tp*        pointer;
1941    typedef const _Tp*        const_pointer;
1942    typedef const _Tp&        reference;
1943    typedef const _Tp&        const_reference;
1944    typedef const _Tp         value_type;
1945
1946    typedef true_type propagate_on_container_move_assignment;
1947    typedef true_type is_always_equal;
1948
1949    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1950
1951    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1952    allocator() _NOEXCEPT {}
1953
1954    template <class _Up>
1955    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1956    allocator(const allocator<_Up>&) _NOEXCEPT {}
1957
1958    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1959        {return _VSTD::addressof(__x);}
1960    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1961    {
1962        if (__n > max_size())
1963            __throw_length_error("allocator<const T>::allocate(size_t n)"
1964                                 " 'n' exceeds maximum supported size");
1965        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1966    }
1967    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
1968        {_VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
1969    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1970        {return size_type(~0) / sizeof(_Tp);}
1971#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1972    template <class _Up, class... _Args>
1973        _LIBCPP_INLINE_VISIBILITY
1974        void
1975        construct(_Up* __p, _Args&&... __args)
1976        {
1977            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1978        }
1979#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1980        _LIBCPP_INLINE_VISIBILITY
1981        void
1982        construct(pointer __p)
1983        {
1984            ::new((void*) const_cast<_Tp *>(__p)) _Tp();
1985        }
1986# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1987
1988    template <class _A0>
1989        _LIBCPP_INLINE_VISIBILITY
1990        void
1991        construct(pointer __p, _A0& __a0)
1992        {
1993            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
1994        }
1995    template <class _A0>
1996        _LIBCPP_INLINE_VISIBILITY
1997        void
1998        construct(pointer __p, const _A0& __a0)
1999        {
2000            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
2001        }
2002# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2003    template <class _A0, class _A1>
2004        _LIBCPP_INLINE_VISIBILITY
2005        void
2006        construct(pointer __p, _A0& __a0, _A1& __a1)
2007        {
2008            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
2009        }
2010    template <class _A0, class _A1>
2011        _LIBCPP_INLINE_VISIBILITY
2012        void
2013        construct(pointer __p, const _A0& __a0, _A1& __a1)
2014        {
2015            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
2016        }
2017    template <class _A0, class _A1>
2018        _LIBCPP_INLINE_VISIBILITY
2019        void
2020        construct(pointer __p, _A0& __a0, const _A1& __a1)
2021        {
2022            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
2023        }
2024    template <class _A0, class _A1>
2025        _LIBCPP_INLINE_VISIBILITY
2026        void
2027        construct(pointer __p, const _A0& __a0, const _A1& __a1)
2028        {
2029            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
2030        }
2031#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
2032    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
2033};
2034
2035template <class _Tp, class _Up>
2036inline _LIBCPP_INLINE_VISIBILITY
2037bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
2038
2039template <class _Tp, class _Up>
2040inline _LIBCPP_INLINE_VISIBILITY
2041bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
2042
2043template <class _OutputIterator, class _Tp>
2044class _LIBCPP_TEMPLATE_VIS raw_storage_iterator
2045    : public iterator<output_iterator_tag,
2046                      _Tp,                                         // purposefully not C++03
2047                      ptrdiff_t,                                   // purposefully not C++03
2048                      _Tp*,                                        // purposefully not C++03
2049                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
2050{
2051private:
2052    _OutputIterator __x_;
2053public:
2054    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
2055    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
2056    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
2057        {::new(_VSTD::addressof(*__x_)) _Tp(__element); return *this;}
2058#if _LIBCPP_STD_VER >= 14
2059    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
2060        {::new(_VSTD::addressof(*__x_)) _Tp(_VSTD::move(__element)); return *this;}
2061#endif
2062    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
2063    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
2064        {raw_storage_iterator __t(*this); ++__x_; return __t;}
2065#if _LIBCPP_STD_VER >= 14
2066    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
2067#endif
2068};
2069
2070template <class _Tp>
2071_LIBCPP_NODISCARD_EXT _LIBCPP_NO_CFI
2072pair<_Tp*, ptrdiff_t>
2073get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
2074{
2075    pair<_Tp*, ptrdiff_t> __r(0, 0);
2076    const ptrdiff_t __m = (~ptrdiff_t(0) ^
2077                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
2078                           / sizeof(_Tp);
2079    if (__n > __m)
2080        __n = __m;
2081    while (__n > 0)
2082    {
2083#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
2084    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
2085        {
2086            std::align_val_t __al =
2087                std::align_val_t(std::alignment_of<_Tp>::value);
2088            __r.first = static_cast<_Tp*>(::operator new(
2089                __n * sizeof(_Tp), __al, nothrow));
2090        } else {
2091            __r.first = static_cast<_Tp*>(::operator new(
2092                __n * sizeof(_Tp), nothrow));
2093        }
2094#else
2095    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
2096        {
2097            // Since aligned operator new is unavailable, return an empty
2098            // buffer rather than one with invalid alignment.
2099            return __r;
2100        }
2101
2102        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
2103#endif
2104
2105        if (__r.first)
2106        {
2107            __r.second = __n;
2108            break;
2109        }
2110        __n /= 2;
2111    }
2112    return __r;
2113}
2114
2115template <class _Tp>
2116inline _LIBCPP_INLINE_VISIBILITY
2117void return_temporary_buffer(_Tp* __p) _NOEXCEPT
2118{
2119  _VSTD::__libcpp_deallocate_unsized((void*)__p, _LIBCPP_ALIGNOF(_Tp));
2120}
2121
2122#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2123template <class _Tp>
2124struct _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr_ref
2125{
2126    _Tp* __ptr_;
2127};
2128
2129template<class _Tp>
2130class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr
2131{
2132private:
2133    _Tp* __ptr_;
2134public:
2135    typedef _Tp element_type;
2136
2137    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) throw() : __ptr_(__p) {}
2138    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) throw() : __ptr_(__p.release()) {}
2139    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) throw()
2140        : __ptr_(__p.release()) {}
2141    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) throw()
2142        {reset(__p.release()); return *this;}
2143    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) throw()
2144        {reset(__p.release()); return *this;}
2145    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) throw()
2146        {reset(__p.__ptr_); return *this;}
2147    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() throw() {delete __ptr_;}
2148
2149    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const throw()
2150        {return *__ptr_;}
2151    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const throw() {return __ptr_;}
2152    _LIBCPP_INLINE_VISIBILITY _Tp* get() const throw() {return __ptr_;}
2153    _LIBCPP_INLINE_VISIBILITY _Tp* release() throw()
2154    {
2155        _Tp* __t = __ptr_;
2156        __ptr_ = 0;
2157        return __t;
2158    }
2159    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) throw()
2160    {
2161        if (__ptr_ != __p)
2162            delete __ptr_;
2163        __ptr_ = __p;
2164    }
2165
2166    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) throw() : __ptr_(__p.__ptr_) {}
2167    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() throw()
2168        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
2169    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() throw()
2170        {return auto_ptr<_Up>(release());}
2171};
2172
2173template <>
2174class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr<void>
2175{
2176public:
2177    typedef void element_type;
2178};
2179#endif
2180
2181template <class _Tp, int _Idx,
2182          bool _CanBeEmptyBase =
2183              is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value>
2184struct __compressed_pair_elem {
2185  typedef _Tp _ParamT;
2186  typedef _Tp& reference;
2187  typedef const _Tp& const_reference;
2188
2189#ifndef _LIBCPP_CXX03_LANG
2190  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() : __value_() {}
2191
2192  template <class _Up, class = typename enable_if<
2193      !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2194  >::type>
2195  _LIBCPP_INLINE_VISIBILITY
2196  constexpr explicit
2197  __compressed_pair_elem(_Up&& __u)
2198      : __value_(_VSTD::forward<_Up>(__u))
2199    {
2200    }
2201
2202  template <class... _Args, size_t... _Indexes>
2203  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2204  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2205                         __tuple_indices<_Indexes...>)
2206      : __value_(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2207#else
2208  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_() {}
2209  _LIBCPP_INLINE_VISIBILITY
2210  __compressed_pair_elem(_ParamT __p) : __value_(std::forward<_ParamT>(__p)) {}
2211#endif
2212
2213  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return __value_; }
2214  _LIBCPP_INLINE_VISIBILITY
2215  const_reference __get() const _NOEXCEPT { return __value_; }
2216
2217private:
2218  _Tp __value_;
2219};
2220
2221template <class _Tp, int _Idx>
2222struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp {
2223  typedef _Tp _ParamT;
2224  typedef _Tp& reference;
2225  typedef const _Tp& const_reference;
2226  typedef _Tp __value_type;
2227
2228#ifndef _LIBCPP_CXX03_LANG
2229  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() = default;
2230
2231  template <class _Up, class = typename enable_if<
2232        !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2233  >::type>
2234  _LIBCPP_INLINE_VISIBILITY
2235  constexpr explicit
2236  __compressed_pair_elem(_Up&& __u)
2237      : __value_type(_VSTD::forward<_Up>(__u))
2238  {}
2239
2240  template <class... _Args, size_t... _Indexes>
2241  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2242  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2243                         __tuple_indices<_Indexes...>)
2244      : __value_type(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2245#else
2246  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_type() {}
2247  _LIBCPP_INLINE_VISIBILITY
2248  __compressed_pair_elem(_ParamT __p)
2249      : __value_type(std::forward<_ParamT>(__p)) {}
2250#endif
2251
2252  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return *this; }
2253  _LIBCPP_INLINE_VISIBILITY
2254  const_reference __get() const _NOEXCEPT { return *this; }
2255};
2256
2257// Tag used to construct the second element of the compressed pair.
2258struct __second_tag {};
2259
2260template <class _T1, class _T2>
2261class __compressed_pair : private __compressed_pair_elem<_T1, 0>,
2262                          private __compressed_pair_elem<_T2, 1> {
2263  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T1, 0> _Base1;
2264  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T2, 1> _Base2;
2265
2266  // NOTE: This static assert should never fire because __compressed_pair
2267  // is *almost never* used in a scenario where it's possible for T1 == T2.
2268  // (The exception is std::function where it is possible that the function
2269  //  object and the allocator have the same type).
2270  static_assert((!is_same<_T1, _T2>::value),
2271    "__compressed_pair cannot be instantated when T1 and T2 are the same type; "
2272    "The current implementation is NOT ABI-compatible with the previous "
2273    "implementation for this configuration");
2274
2275public:
2276#ifndef _LIBCPP_CXX03_LANG
2277  template <bool _Dummy = true,
2278      class = typename enable_if<
2279          __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
2280          __dependent_type<is_default_constructible<_T2>, _Dummy>::value
2281      >::type
2282  >
2283  _LIBCPP_INLINE_VISIBILITY
2284  constexpr __compressed_pair() {}
2285
2286  template <class _Tp, typename enable_if<!is_same<typename decay<_Tp>::type,
2287                                                   __compressed_pair>::value,
2288                                          bool>::type = true>
2289  _LIBCPP_INLINE_VISIBILITY constexpr explicit
2290  __compressed_pair(_Tp&& __t)
2291      : _Base1(std::forward<_Tp>(__t)), _Base2() {}
2292
2293  template <class _Tp>
2294  _LIBCPP_INLINE_VISIBILITY constexpr
2295  __compressed_pair(__second_tag, _Tp&& __t)
2296      : _Base1(), _Base2(std::forward<_Tp>(__t)) {}
2297
2298  template <class _U1, class _U2>
2299  _LIBCPP_INLINE_VISIBILITY constexpr
2300  __compressed_pair(_U1&& __t1, _U2&& __t2)
2301      : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {}
2302
2303  template <class... _Args1, class... _Args2>
2304  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2305  __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
2306                    tuple<_Args2...> __second_args)
2307      : _Base1(__pc, _VSTD::move(__first_args),
2308               typename __make_tuple_indices<sizeof...(_Args1)>::type()),
2309        _Base2(__pc, _VSTD::move(__second_args),
2310               typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}
2311
2312#else
2313  _LIBCPP_INLINE_VISIBILITY
2314  __compressed_pair() {}
2315
2316  _LIBCPP_INLINE_VISIBILITY explicit
2317  __compressed_pair(_T1 __t1) : _Base1(_VSTD::forward<_T1>(__t1)) {}
2318
2319  _LIBCPP_INLINE_VISIBILITY
2320  __compressed_pair(__second_tag, _T2 __t2)
2321      : _Base1(), _Base2(_VSTD::forward<_T2>(__t2)) {}
2322
2323  _LIBCPP_INLINE_VISIBILITY
2324  __compressed_pair(_T1 __t1, _T2 __t2)
2325      : _Base1(_VSTD::forward<_T1>(__t1)), _Base2(_VSTD::forward<_T2>(__t2)) {}
2326#endif
2327
2328  _LIBCPP_INLINE_VISIBILITY
2329  typename _Base1::reference first() _NOEXCEPT {
2330    return static_cast<_Base1&>(*this).__get();
2331  }
2332
2333  _LIBCPP_INLINE_VISIBILITY
2334  typename _Base1::const_reference first() const _NOEXCEPT {
2335    return static_cast<_Base1 const&>(*this).__get();
2336  }
2337
2338  _LIBCPP_INLINE_VISIBILITY
2339  typename _Base2::reference second() _NOEXCEPT {
2340    return static_cast<_Base2&>(*this).__get();
2341  }
2342
2343  _LIBCPP_INLINE_VISIBILITY
2344  typename _Base2::const_reference second() const _NOEXCEPT {
2345    return static_cast<_Base2 const&>(*this).__get();
2346  }
2347
2348  _LIBCPP_INLINE_VISIBILITY
2349  void swap(__compressed_pair& __x)
2350    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2351               __is_nothrow_swappable<_T2>::value)
2352  {
2353    using std::swap;
2354    swap(first(), __x.first());
2355    swap(second(), __x.second());
2356  }
2357};
2358
2359template <class _T1, class _T2>
2360inline _LIBCPP_INLINE_VISIBILITY
2361void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
2362    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2363               __is_nothrow_swappable<_T2>::value) {
2364  __x.swap(__y);
2365}
2366
2367// default_delete
2368
2369template <class _Tp>
2370struct _LIBCPP_TEMPLATE_VIS default_delete {
2371    static_assert(!is_function<_Tp>::value,
2372                  "default_delete cannot be instantiated for function types");
2373#ifndef _LIBCPP_CXX03_LANG
2374  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2375#else
2376  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2377#endif
2378  template <class _Up>
2379  _LIBCPP_INLINE_VISIBILITY
2380  default_delete(const default_delete<_Up>&,
2381                 typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* =
2382                     0) _NOEXCEPT {}
2383
2384  _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __ptr) const _NOEXCEPT {
2385    static_assert(sizeof(_Tp) > 0,
2386                  "default_delete can not delete incomplete type");
2387    static_assert(!is_void<_Tp>::value,
2388                  "default_delete can not delete incomplete type");
2389    delete __ptr;
2390  }
2391};
2392
2393template <class _Tp>
2394struct _LIBCPP_TEMPLATE_VIS default_delete<_Tp[]> {
2395private:
2396  template <class _Up>
2397  struct _EnableIfConvertible
2398      : enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value> {};
2399
2400public:
2401#ifndef _LIBCPP_CXX03_LANG
2402  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2403#else
2404  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2405#endif
2406
2407  template <class _Up>
2408  _LIBCPP_INLINE_VISIBILITY
2409  default_delete(const default_delete<_Up[]>&,
2410                 typename _EnableIfConvertible<_Up>::type* = 0) _NOEXCEPT {}
2411
2412  template <class _Up>
2413  _LIBCPP_INLINE_VISIBILITY
2414  typename _EnableIfConvertible<_Up>::type
2415  operator()(_Up* __ptr) const _NOEXCEPT {
2416    static_assert(sizeof(_Tp) > 0,
2417                  "default_delete can not delete incomplete type");
2418    static_assert(!is_void<_Tp>::value,
2419                  "default_delete can not delete void type");
2420    delete[] __ptr;
2421  }
2422};
2423
2424template <class _Deleter>
2425struct __unique_ptr_deleter_sfinae {
2426  static_assert(!is_reference<_Deleter>::value, "incorrect specialization");
2427  typedef const _Deleter& __lval_ref_type;
2428  typedef _Deleter&& __good_rval_ref_type;
2429  typedef true_type __enable_rval_overload;
2430};
2431
2432template <class _Deleter>
2433struct __unique_ptr_deleter_sfinae<_Deleter const&> {
2434  typedef const _Deleter& __lval_ref_type;
2435  typedef const _Deleter&& __bad_rval_ref_type;
2436  typedef false_type __enable_rval_overload;
2437};
2438
2439template <class _Deleter>
2440struct __unique_ptr_deleter_sfinae<_Deleter&> {
2441  typedef _Deleter& __lval_ref_type;
2442  typedef _Deleter&& __bad_rval_ref_type;
2443  typedef false_type __enable_rval_overload;
2444};
2445
2446template <class _Tp, class _Dp = default_delete<_Tp> >
2447class _LIBCPP_TEMPLATE_VIS unique_ptr {
2448public:
2449  typedef _Tp element_type;
2450  typedef _Dp deleter_type;
2451  typedef _LIBCPP_NODEBUG_TYPE typename __pointer_type<_Tp, deleter_type>::type pointer;
2452
2453  static_assert(!is_rvalue_reference<deleter_type>::value,
2454                "the specified deleter type cannot be an rvalue reference");
2455
2456private:
2457  __compressed_pair<pointer, deleter_type> __ptr_;
2458
2459  struct __nat { int __for_bool_; };
2460
2461  typedef _LIBCPP_NODEBUG_TYPE __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2462
2463  template <bool _Dummy>
2464  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2465      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2466
2467  template <bool _Dummy>
2468  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2469      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2470
2471  template <bool _Dummy>
2472  using _BadRValRefType _LIBCPP_NODEBUG_TYPE  =
2473      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2474
2475  template <bool _Dummy, class _Deleter = typename __dependent_type<
2476                             __identity<deleter_type>, _Dummy>::type>
2477  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE =
2478      typename enable_if<is_default_constructible<_Deleter>::value &&
2479                         !is_pointer<_Deleter>::value>::type;
2480
2481  template <class _ArgType>
2482  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2483      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2484
2485  template <class _UPtr, class _Up>
2486  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2487      is_convertible<typename _UPtr::pointer, pointer>::value &&
2488      !is_array<_Up>::value
2489  >::type;
2490
2491  template <class _UDel>
2492  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2493      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2494      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2495    >::type;
2496
2497  template <class _UDel>
2498  using _EnableIfDeleterAssignable = typename enable_if<
2499      is_assignable<_Dp&, _UDel&&>::value
2500    >::type;
2501
2502public:
2503  template <bool _Dummy = true,
2504            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2505  _LIBCPP_INLINE_VISIBILITY
2506  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer()) {}
2507
2508  template <bool _Dummy = true,
2509            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2510  _LIBCPP_INLINE_VISIBILITY
2511  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer()) {}
2512
2513  template <bool _Dummy = true,
2514            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2515  _LIBCPP_INLINE_VISIBILITY
2516  explicit unique_ptr(pointer __p) _NOEXCEPT : __ptr_(__p) {}
2517
2518  template <bool _Dummy = true,
2519            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2520  _LIBCPP_INLINE_VISIBILITY
2521  unique_ptr(pointer __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2522      : __ptr_(__p, __d) {}
2523
2524  template <bool _Dummy = true,
2525            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2526  _LIBCPP_INLINE_VISIBILITY
2527  unique_ptr(pointer __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2528      : __ptr_(__p, _VSTD::move(__d)) {
2529    static_assert(!is_reference<deleter_type>::value,
2530                  "rvalue deleter bound to reference");
2531  }
2532
2533  template <bool _Dummy = true,
2534            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> > >
2535  _LIBCPP_INLINE_VISIBILITY
2536  unique_ptr(pointer __p, _BadRValRefType<_Dummy> __d) = delete;
2537
2538  _LIBCPP_INLINE_VISIBILITY
2539  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2540      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2541  }
2542
2543  template <class _Up, class _Ep,
2544      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2545      class = _EnableIfDeleterConvertible<_Ep>
2546  >
2547  _LIBCPP_INLINE_VISIBILITY
2548  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2549      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
2550
2551#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2552  template <class _Up>
2553  _LIBCPP_INLINE_VISIBILITY
2554  unique_ptr(auto_ptr<_Up>&& __p,
2555             typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2556                                    is_same<_Dp, default_delete<_Tp> >::value,
2557                                __nat>::type = __nat()) _NOEXCEPT
2558      : __ptr_(__p.release()) {}
2559#endif
2560
2561  _LIBCPP_INLINE_VISIBILITY
2562  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2563    reset(__u.release());
2564    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2565    return *this;
2566  }
2567
2568  template <class _Up, class _Ep,
2569      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2570      class = _EnableIfDeleterAssignable<_Ep>
2571  >
2572  _LIBCPP_INLINE_VISIBILITY
2573  unique_ptr& operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2574    reset(__u.release());
2575    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2576    return *this;
2577  }
2578
2579#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2580  template <class _Up>
2581  _LIBCPP_INLINE_VISIBILITY
2582      typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2583                             is_same<_Dp, default_delete<_Tp> >::value,
2584                         unique_ptr&>::type
2585      operator=(auto_ptr<_Up> __p) {
2586    reset(__p.release());
2587    return *this;
2588  }
2589#endif
2590
2591#ifdef _LIBCPP_CXX03_LANG
2592  unique_ptr(unique_ptr const&) = delete;
2593  unique_ptr& operator=(unique_ptr const&) = delete;
2594#endif
2595
2596
2597  _LIBCPP_INLINE_VISIBILITY
2598  ~unique_ptr() { reset(); }
2599
2600  _LIBCPP_INLINE_VISIBILITY
2601  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2602    reset();
2603    return *this;
2604  }
2605
2606  _LIBCPP_INLINE_VISIBILITY
2607  typename add_lvalue_reference<_Tp>::type
2608  operator*() const {
2609    return *__ptr_.first();
2610  }
2611  _LIBCPP_INLINE_VISIBILITY
2612  pointer operator->() const _NOEXCEPT {
2613    return __ptr_.first();
2614  }
2615  _LIBCPP_INLINE_VISIBILITY
2616  pointer get() const _NOEXCEPT {
2617    return __ptr_.first();
2618  }
2619  _LIBCPP_INLINE_VISIBILITY
2620  deleter_type& get_deleter() _NOEXCEPT {
2621    return __ptr_.second();
2622  }
2623  _LIBCPP_INLINE_VISIBILITY
2624  const deleter_type& get_deleter() const _NOEXCEPT {
2625    return __ptr_.second();
2626  }
2627  _LIBCPP_INLINE_VISIBILITY
2628  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2629    return __ptr_.first() != nullptr;
2630  }
2631
2632  _LIBCPP_INLINE_VISIBILITY
2633  pointer release() _NOEXCEPT {
2634    pointer __t = __ptr_.first();
2635    __ptr_.first() = pointer();
2636    return __t;
2637  }
2638
2639  _LIBCPP_INLINE_VISIBILITY
2640  void reset(pointer __p = pointer()) _NOEXCEPT {
2641    pointer __tmp = __ptr_.first();
2642    __ptr_.first() = __p;
2643    if (__tmp)
2644      __ptr_.second()(__tmp);
2645  }
2646
2647  _LIBCPP_INLINE_VISIBILITY
2648  void swap(unique_ptr& __u) _NOEXCEPT {
2649    __ptr_.swap(__u.__ptr_);
2650  }
2651};
2652
2653
2654template <class _Tp, class _Dp>
2655class _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
2656public:
2657  typedef _Tp element_type;
2658  typedef _Dp deleter_type;
2659  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2660
2661private:
2662  __compressed_pair<pointer, deleter_type> __ptr_;
2663
2664  template <class _From>
2665  struct _CheckArrayPointerConversion : is_same<_From, pointer> {};
2666
2667  template <class _FromElem>
2668  struct _CheckArrayPointerConversion<_FromElem*>
2669      : integral_constant<bool,
2670          is_same<_FromElem*, pointer>::value ||
2671            (is_same<pointer, element_type*>::value &&
2672             is_convertible<_FromElem(*)[], element_type(*)[]>::value)
2673      >
2674  {};
2675
2676  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2677
2678  template <bool _Dummy>
2679  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2680      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2681
2682  template <bool _Dummy>
2683  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2684      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2685
2686  template <bool _Dummy>
2687  using _BadRValRefType _LIBCPP_NODEBUG_TYPE =
2688      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2689
2690  template <bool _Dummy, class _Deleter = typename __dependent_type<
2691                             __identity<deleter_type>, _Dummy>::type>
2692  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE  =
2693      typename enable_if<is_default_constructible<_Deleter>::value &&
2694                         !is_pointer<_Deleter>::value>::type;
2695
2696  template <class _ArgType>
2697  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2698      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2699
2700  template <class _Pp>
2701  using _EnableIfPointerConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2702      _CheckArrayPointerConversion<_Pp>::value
2703  >::type;
2704
2705  template <class _UPtr, class _Up,
2706        class _ElemT = typename _UPtr::element_type>
2707  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2708      is_array<_Up>::value &&
2709      is_same<pointer, element_type*>::value &&
2710      is_same<typename _UPtr::pointer, _ElemT*>::value &&
2711      is_convertible<_ElemT(*)[], element_type(*)[]>::value
2712    >::type;
2713
2714  template <class _UDel>
2715  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2716      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2717      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2718    >::type;
2719
2720  template <class _UDel>
2721  using _EnableIfDeleterAssignable _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2722      is_assignable<_Dp&, _UDel&&>::value
2723    >::type;
2724
2725public:
2726  template <bool _Dummy = true,
2727            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2728  _LIBCPP_INLINE_VISIBILITY
2729  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer()) {}
2730
2731  template <bool _Dummy = true,
2732            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2733  _LIBCPP_INLINE_VISIBILITY
2734  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer()) {}
2735
2736  template <class _Pp, bool _Dummy = true,
2737            class = _EnableIfDeleterDefaultConstructible<_Dummy>,
2738            class = _EnableIfPointerConvertible<_Pp> >
2739  _LIBCPP_INLINE_VISIBILITY
2740  explicit unique_ptr(_Pp __p) _NOEXCEPT
2741      : __ptr_(__p) {}
2742
2743  template <class _Pp, bool _Dummy = true,
2744            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> >,
2745            class = _EnableIfPointerConvertible<_Pp> >
2746  _LIBCPP_INLINE_VISIBILITY
2747  unique_ptr(_Pp __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2748      : __ptr_(__p, __d) {}
2749
2750  template <bool _Dummy = true,
2751            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2752  _LIBCPP_INLINE_VISIBILITY
2753  unique_ptr(nullptr_t, _LValRefType<_Dummy> __d) _NOEXCEPT
2754      : __ptr_(nullptr, __d) {}
2755
2756  template <class _Pp, bool _Dummy = true,
2757            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> >,
2758            class = _EnableIfPointerConvertible<_Pp> >
2759  _LIBCPP_INLINE_VISIBILITY
2760  unique_ptr(_Pp __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2761      : __ptr_(__p, _VSTD::move(__d)) {
2762    static_assert(!is_reference<deleter_type>::value,
2763                  "rvalue deleter bound to reference");
2764  }
2765
2766  template <bool _Dummy = true,
2767            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2768  _LIBCPP_INLINE_VISIBILITY
2769  unique_ptr(nullptr_t, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2770      : __ptr_(nullptr, _VSTD::move(__d)) {
2771    static_assert(!is_reference<deleter_type>::value,
2772                  "rvalue deleter bound to reference");
2773  }
2774
2775  template <class _Pp, bool _Dummy = true,
2776            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> >,
2777            class = _EnableIfPointerConvertible<_Pp> >
2778  _LIBCPP_INLINE_VISIBILITY
2779  unique_ptr(_Pp __p, _BadRValRefType<_Dummy> __d) = delete;
2780
2781  _LIBCPP_INLINE_VISIBILITY
2782  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2783      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2784  }
2785
2786  _LIBCPP_INLINE_VISIBILITY
2787  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2788    reset(__u.release());
2789    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2790    return *this;
2791  }
2792
2793  template <class _Up, class _Ep,
2794      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2795      class = _EnableIfDeleterConvertible<_Ep>
2796  >
2797  _LIBCPP_INLINE_VISIBILITY
2798  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2799      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {
2800  }
2801
2802  template <class _Up, class _Ep,
2803      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2804      class = _EnableIfDeleterAssignable<_Ep>
2805  >
2806  _LIBCPP_INLINE_VISIBILITY
2807  unique_ptr&
2808  operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2809    reset(__u.release());
2810    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2811    return *this;
2812  }
2813
2814#ifdef _LIBCPP_CXX03_LANG
2815  unique_ptr(unique_ptr const&) = delete;
2816  unique_ptr& operator=(unique_ptr const&) = delete;
2817#endif
2818
2819public:
2820  _LIBCPP_INLINE_VISIBILITY
2821  ~unique_ptr() { reset(); }
2822
2823  _LIBCPP_INLINE_VISIBILITY
2824  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2825    reset();
2826    return *this;
2827  }
2828
2829  _LIBCPP_INLINE_VISIBILITY
2830  typename add_lvalue_reference<_Tp>::type
2831  operator[](size_t __i) const {
2832    return __ptr_.first()[__i];
2833  }
2834  _LIBCPP_INLINE_VISIBILITY
2835  pointer get() const _NOEXCEPT {
2836    return __ptr_.first();
2837  }
2838
2839  _LIBCPP_INLINE_VISIBILITY
2840  deleter_type& get_deleter() _NOEXCEPT {
2841    return __ptr_.second();
2842  }
2843
2844  _LIBCPP_INLINE_VISIBILITY
2845  const deleter_type& get_deleter() const _NOEXCEPT {
2846    return __ptr_.second();
2847  }
2848  _LIBCPP_INLINE_VISIBILITY
2849  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2850    return __ptr_.first() != nullptr;
2851  }
2852
2853  _LIBCPP_INLINE_VISIBILITY
2854  pointer release() _NOEXCEPT {
2855    pointer __t = __ptr_.first();
2856    __ptr_.first() = pointer();
2857    return __t;
2858  }
2859
2860  template <class _Pp>
2861  _LIBCPP_INLINE_VISIBILITY
2862  typename enable_if<
2863      _CheckArrayPointerConversion<_Pp>::value
2864  >::type
2865  reset(_Pp __p) _NOEXCEPT {
2866    pointer __tmp = __ptr_.first();
2867    __ptr_.first() = __p;
2868    if (__tmp)
2869      __ptr_.second()(__tmp);
2870  }
2871
2872  _LIBCPP_INLINE_VISIBILITY
2873  void reset(nullptr_t = nullptr) _NOEXCEPT {
2874    pointer __tmp = __ptr_.first();
2875    __ptr_.first() = nullptr;
2876    if (__tmp)
2877      __ptr_.second()(__tmp);
2878  }
2879
2880  _LIBCPP_INLINE_VISIBILITY
2881  void swap(unique_ptr& __u) _NOEXCEPT {
2882    __ptr_.swap(__u.__ptr_);
2883  }
2884
2885};
2886
2887template <class _Tp, class _Dp>
2888inline _LIBCPP_INLINE_VISIBILITY
2889typename enable_if<
2890    __is_swappable<_Dp>::value,
2891    void
2892>::type
2893swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
2894
2895template <class _T1, class _D1, class _T2, class _D2>
2896inline _LIBCPP_INLINE_VISIBILITY
2897bool
2898operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
2899
2900template <class _T1, class _D1, class _T2, class _D2>
2901inline _LIBCPP_INLINE_VISIBILITY
2902bool
2903operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
2904
2905template <class _T1, class _D1, class _T2, class _D2>
2906inline _LIBCPP_INLINE_VISIBILITY
2907bool
2908operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
2909{
2910    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2911    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
2912    typedef typename common_type<_P1, _P2>::type _Vp;
2913    return less<_Vp>()(__x.get(), __y.get());
2914}
2915
2916template <class _T1, class _D1, class _T2, class _D2>
2917inline _LIBCPP_INLINE_VISIBILITY
2918bool
2919operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
2920
2921template <class _T1, class _D1, class _T2, class _D2>
2922inline _LIBCPP_INLINE_VISIBILITY
2923bool
2924operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
2925
2926template <class _T1, class _D1, class _T2, class _D2>
2927inline _LIBCPP_INLINE_VISIBILITY
2928bool
2929operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
2930
2931template <class _T1, class _D1>
2932inline _LIBCPP_INLINE_VISIBILITY
2933bool
2934operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2935{
2936    return !__x;
2937}
2938
2939template <class _T1, class _D1>
2940inline _LIBCPP_INLINE_VISIBILITY
2941bool
2942operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2943{
2944    return !__x;
2945}
2946
2947template <class _T1, class _D1>
2948inline _LIBCPP_INLINE_VISIBILITY
2949bool
2950operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2951{
2952    return static_cast<bool>(__x);
2953}
2954
2955template <class _T1, class _D1>
2956inline _LIBCPP_INLINE_VISIBILITY
2957bool
2958operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2959{
2960    return static_cast<bool>(__x);
2961}
2962
2963template <class _T1, class _D1>
2964inline _LIBCPP_INLINE_VISIBILITY
2965bool
2966operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2967{
2968    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2969    return less<_P1>()(__x.get(), nullptr);
2970}
2971
2972template <class _T1, class _D1>
2973inline _LIBCPP_INLINE_VISIBILITY
2974bool
2975operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2976{
2977    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2978    return less<_P1>()(nullptr, __x.get());
2979}
2980
2981template <class _T1, class _D1>
2982inline _LIBCPP_INLINE_VISIBILITY
2983bool
2984operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2985{
2986    return nullptr < __x;
2987}
2988
2989template <class _T1, class _D1>
2990inline _LIBCPP_INLINE_VISIBILITY
2991bool
2992operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2993{
2994    return __x < nullptr;
2995}
2996
2997template <class _T1, class _D1>
2998inline _LIBCPP_INLINE_VISIBILITY
2999bool
3000operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3001{
3002    return !(nullptr < __x);
3003}
3004
3005template <class _T1, class _D1>
3006inline _LIBCPP_INLINE_VISIBILITY
3007bool
3008operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3009{
3010    return !(__x < nullptr);
3011}
3012
3013template <class _T1, class _D1>
3014inline _LIBCPP_INLINE_VISIBILITY
3015bool
3016operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3017{
3018    return !(__x < nullptr);
3019}
3020
3021template <class _T1, class _D1>
3022inline _LIBCPP_INLINE_VISIBILITY
3023bool
3024operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3025{
3026    return !(nullptr < __x);
3027}
3028
3029#if _LIBCPP_STD_VER > 11
3030
3031template<class _Tp>
3032struct __unique_if
3033{
3034    typedef unique_ptr<_Tp> __unique_single;
3035};
3036
3037template<class _Tp>
3038struct __unique_if<_Tp[]>
3039{
3040    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
3041};
3042
3043template<class _Tp, size_t _Np>
3044struct __unique_if<_Tp[_Np]>
3045{
3046    typedef void __unique_array_known_bound;
3047};
3048
3049template<class _Tp, class... _Args>
3050inline _LIBCPP_INLINE_VISIBILITY
3051typename __unique_if<_Tp>::__unique_single
3052make_unique(_Args&&... __args)
3053{
3054    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
3055}
3056
3057template<class _Tp>
3058inline _LIBCPP_INLINE_VISIBILITY
3059typename __unique_if<_Tp>::__unique_array_unknown_bound
3060make_unique(size_t __n)
3061{
3062    typedef typename remove_extent<_Tp>::type _Up;
3063    return unique_ptr<_Tp>(new _Up[__n]());
3064}
3065
3066template<class _Tp, class... _Args>
3067    typename __unique_if<_Tp>::__unique_array_known_bound
3068    make_unique(_Args&&...) = delete;
3069
3070#endif  // _LIBCPP_STD_VER > 11
3071
3072template <class _Tp, class _Dp>
3073#ifdef _LIBCPP_CXX03_LANG
3074struct _LIBCPP_TEMPLATE_VIS hash<unique_ptr<_Tp, _Dp> >
3075#else
3076struct _LIBCPP_TEMPLATE_VIS hash<__enable_hash_helper<
3077    unique_ptr<_Tp, _Dp>, typename unique_ptr<_Tp, _Dp>::pointer> >
3078#endif
3079{
3080    typedef unique_ptr<_Tp, _Dp> argument_type;
3081    typedef size_t               result_type;
3082    _LIBCPP_INLINE_VISIBILITY
3083    result_type operator()(const argument_type& __ptr) const
3084    {
3085        typedef typename argument_type::pointer pointer;
3086        return hash<pointer>()(__ptr.get());
3087    }
3088};
3089
3090struct __destruct_n
3091{
3092private:
3093    size_t __size_;
3094
3095    template <class _Tp>
3096    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
3097        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
3098
3099    template <class _Tp>
3100    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
3101        {}
3102
3103    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
3104        {++__size_;}
3105    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
3106        {}
3107
3108    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
3109        {__size_ = __s;}
3110    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
3111        {}
3112public:
3113    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
3114        : __size_(__s) {}
3115
3116    template <class _Tp>
3117    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
3118        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3119
3120    template <class _Tp>
3121    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
3122        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3123
3124    template <class _Tp>
3125    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
3126        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3127};
3128
3129template <class _Alloc>
3130class __allocator_destructor
3131{
3132    typedef _LIBCPP_NODEBUG_TYPE allocator_traits<_Alloc> __alloc_traits;
3133public:
3134    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::pointer pointer;
3135    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::size_type size_type;
3136private:
3137    _Alloc& __alloc_;
3138    size_type __s_;
3139public:
3140    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
3141             _NOEXCEPT
3142        : __alloc_(__a), __s_(__s) {}
3143    _LIBCPP_INLINE_VISIBILITY
3144    void operator()(pointer __p) _NOEXCEPT
3145        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
3146};
3147
3148template <class _InputIterator, class _ForwardIterator>
3149_ForwardIterator
3150uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
3151{
3152    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3153#ifndef _LIBCPP_NO_EXCEPTIONS
3154    _ForwardIterator __s = __r;
3155    try
3156    {
3157#endif
3158        for (; __f != __l; ++__f, (void) ++__r)
3159            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3160#ifndef _LIBCPP_NO_EXCEPTIONS
3161    }
3162    catch (...)
3163    {
3164        for (; __s != __r; ++__s)
3165            __s->~value_type();
3166        throw;
3167    }
3168#endif
3169    return __r;
3170}
3171
3172template <class _InputIterator, class _Size, class _ForwardIterator>
3173_ForwardIterator
3174uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
3175{
3176    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3177#ifndef _LIBCPP_NO_EXCEPTIONS
3178    _ForwardIterator __s = __r;
3179    try
3180    {
3181#endif
3182        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
3183            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3184#ifndef _LIBCPP_NO_EXCEPTIONS
3185    }
3186    catch (...)
3187    {
3188        for (; __s != __r; ++__s)
3189            __s->~value_type();
3190        throw;
3191    }
3192#endif
3193    return __r;
3194}
3195
3196template <class _ForwardIterator, class _Tp>
3197void
3198uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
3199{
3200    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3201#ifndef _LIBCPP_NO_EXCEPTIONS
3202    _ForwardIterator __s = __f;
3203    try
3204    {
3205#endif
3206        for (; __f != __l; ++__f)
3207            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3208#ifndef _LIBCPP_NO_EXCEPTIONS
3209    }
3210    catch (...)
3211    {
3212        for (; __s != __f; ++__s)
3213            __s->~value_type();
3214        throw;
3215    }
3216#endif
3217}
3218
3219template <class _ForwardIterator, class _Size, class _Tp>
3220_ForwardIterator
3221uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
3222{
3223    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3224#ifndef _LIBCPP_NO_EXCEPTIONS
3225    _ForwardIterator __s = __f;
3226    try
3227    {
3228#endif
3229        for (; __n > 0; ++__f, (void) --__n)
3230            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3231#ifndef _LIBCPP_NO_EXCEPTIONS
3232    }
3233    catch (...)
3234    {
3235        for (; __s != __f; ++__s)
3236            __s->~value_type();
3237        throw;
3238    }
3239#endif
3240    return __f;
3241}
3242
3243#if _LIBCPP_STD_VER > 14
3244
3245template <class _Tp>
3246inline _LIBCPP_INLINE_VISIBILITY
3247void destroy_at(_Tp* __loc) {
3248    _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
3249    __loc->~_Tp();
3250}
3251
3252template <class _ForwardIterator>
3253inline _LIBCPP_INLINE_VISIBILITY
3254void destroy(_ForwardIterator __first, _ForwardIterator __last) {
3255    for (; __first != __last; ++__first)
3256        _VSTD::destroy_at(_VSTD::addressof(*__first));
3257}
3258
3259template <class _ForwardIterator, class _Size>
3260inline _LIBCPP_INLINE_VISIBILITY
3261_ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
3262    for (; __n > 0; (void)++__first, --__n)
3263        _VSTD::destroy_at(_VSTD::addressof(*__first));
3264    return __first;
3265}
3266
3267template <class _ForwardIterator>
3268inline _LIBCPP_INLINE_VISIBILITY
3269void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
3270    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3271    auto __idx = __first;
3272#ifndef _LIBCPP_NO_EXCEPTIONS
3273    try {
3274#endif
3275    for (; __idx != __last; ++__idx)
3276        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3277#ifndef _LIBCPP_NO_EXCEPTIONS
3278    } catch (...) {
3279        _VSTD::destroy(__first, __idx);
3280        throw;
3281    }
3282#endif
3283}
3284
3285template <class _ForwardIterator, class _Size>
3286inline _LIBCPP_INLINE_VISIBILITY
3287_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
3288    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3289    auto __idx = __first;
3290#ifndef _LIBCPP_NO_EXCEPTIONS
3291    try {
3292#endif
3293    for (; __n > 0; (void)++__idx, --__n)
3294        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3295    return __idx;
3296#ifndef _LIBCPP_NO_EXCEPTIONS
3297    } catch (...) {
3298        _VSTD::destroy(__first, __idx);
3299        throw;
3300    }
3301#endif
3302}
3303
3304
3305template <class _ForwardIterator>
3306inline _LIBCPP_INLINE_VISIBILITY
3307void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
3308    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3309    auto __idx = __first;
3310#ifndef _LIBCPP_NO_EXCEPTIONS
3311    try {
3312#endif
3313    for (; __idx != __last; ++__idx)
3314        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3315#ifndef _LIBCPP_NO_EXCEPTIONS
3316    } catch (...) {
3317        _VSTD::destroy(__first, __idx);
3318        throw;
3319    }
3320#endif
3321}
3322
3323template <class _ForwardIterator, class _Size>
3324inline _LIBCPP_INLINE_VISIBILITY
3325_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
3326    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3327    auto __idx = __first;
3328#ifndef _LIBCPP_NO_EXCEPTIONS
3329    try {
3330#endif
3331    for (; __n > 0; (void)++__idx, --__n)
3332        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3333    return __idx;
3334#ifndef _LIBCPP_NO_EXCEPTIONS
3335    } catch (...) {
3336        _VSTD::destroy(__first, __idx);
3337        throw;
3338    }
3339#endif
3340}
3341
3342
3343template <class _InputIt, class _ForwardIt>
3344inline _LIBCPP_INLINE_VISIBILITY
3345_ForwardIt uninitialized_move(_InputIt __first, _InputIt __last, _ForwardIt __first_res) {
3346    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3347    auto __idx = __first_res;
3348#ifndef _LIBCPP_NO_EXCEPTIONS
3349    try {
3350#endif
3351    for (; __first != __last; (void)++__idx, ++__first)
3352        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3353    return __idx;
3354#ifndef _LIBCPP_NO_EXCEPTIONS
3355    } catch (...) {
3356        _VSTD::destroy(__first_res, __idx);
3357        throw;
3358    }
3359#endif
3360}
3361
3362template <class _InputIt, class _Size, class _ForwardIt>
3363inline _LIBCPP_INLINE_VISIBILITY
3364pair<_InputIt, _ForwardIt>
3365uninitialized_move_n(_InputIt __first, _Size __n, _ForwardIt __first_res) {
3366    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3367    auto __idx = __first_res;
3368#ifndef _LIBCPP_NO_EXCEPTIONS
3369    try {
3370#endif
3371    for (; __n > 0; ++__idx, (void)++__first, --__n)
3372        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3373    return {__first, __idx};
3374#ifndef _LIBCPP_NO_EXCEPTIONS
3375    } catch (...) {
3376        _VSTD::destroy(__first_res, __idx);
3377        throw;
3378    }
3379#endif
3380}
3381
3382
3383#endif // _LIBCPP_STD_VER > 14
3384
3385// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
3386// should be sufficient for thread safety.
3387// See https://bugs.llvm.org/show_bug.cgi?id=22803
3388#if defined(__clang__) && __has_builtin(__atomic_add_fetch)          \
3389                       && defined(__ATOMIC_RELAXED)                  \
3390                       && defined(__ATOMIC_ACQ_REL)
3391#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3392#elif defined(_LIBCPP_COMPILER_GCC)
3393#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3394#endif
3395
3396template <class _Tp>
3397inline _LIBCPP_INLINE_VISIBILITY _Tp
3398__libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT
3399{
3400#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3401    return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
3402#else
3403    return __t += 1;
3404#endif
3405}
3406
3407template <class _Tp>
3408inline _LIBCPP_INLINE_VISIBILITY _Tp
3409__libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT
3410{
3411#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3412    return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
3413#else
3414    return __t -= 1;
3415#endif
3416}
3417
3418class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
3419    : public std::exception
3420{
3421public:
3422    virtual ~bad_weak_ptr() _NOEXCEPT;
3423    virtual const char* what() const  _NOEXCEPT;
3424};
3425
3426_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
3427void __throw_bad_weak_ptr()
3428{
3429#ifndef _LIBCPP_NO_EXCEPTIONS
3430    throw bad_weak_ptr();
3431#else
3432    _VSTD::abort();
3433#endif
3434}
3435
3436template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr;
3437
3438class _LIBCPP_TYPE_VIS __shared_count
3439{
3440    __shared_count(const __shared_count&);
3441    __shared_count& operator=(const __shared_count&);
3442
3443protected:
3444    long __shared_owners_;
3445    virtual ~__shared_count();
3446private:
3447    virtual void __on_zero_shared() _NOEXCEPT = 0;
3448
3449public:
3450    _LIBCPP_INLINE_VISIBILITY
3451    explicit __shared_count(long __refs = 0) _NOEXCEPT
3452        : __shared_owners_(__refs) {}
3453
3454#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3455    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3456    void __add_shared() _NOEXCEPT;
3457    bool __release_shared() _NOEXCEPT;
3458#else
3459    _LIBCPP_INLINE_VISIBILITY
3460    void __add_shared() _NOEXCEPT {
3461      __libcpp_atomic_refcount_increment(__shared_owners_);
3462    }
3463    _LIBCPP_INLINE_VISIBILITY
3464    bool __release_shared() _NOEXCEPT {
3465      if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
3466        __on_zero_shared();
3467        return true;
3468      }
3469      return false;
3470    }
3471#endif
3472    _LIBCPP_INLINE_VISIBILITY
3473    long use_count() const _NOEXCEPT {
3474        return __libcpp_relaxed_load(&__shared_owners_) + 1;
3475    }
3476};
3477
3478class _LIBCPP_TYPE_VIS __shared_weak_count
3479    : private __shared_count
3480{
3481    long __shared_weak_owners_;
3482
3483public:
3484    _LIBCPP_INLINE_VISIBILITY
3485    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
3486        : __shared_count(__refs),
3487          __shared_weak_owners_(__refs) {}
3488protected:
3489    virtual ~__shared_weak_count();
3490
3491public:
3492#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3493    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3494    void __add_shared() _NOEXCEPT;
3495    void __add_weak() _NOEXCEPT;
3496    void __release_shared() _NOEXCEPT;
3497#else
3498    _LIBCPP_INLINE_VISIBILITY
3499    void __add_shared() _NOEXCEPT {
3500      __shared_count::__add_shared();
3501    }
3502    _LIBCPP_INLINE_VISIBILITY
3503    void __add_weak() _NOEXCEPT {
3504      __libcpp_atomic_refcount_increment(__shared_weak_owners_);
3505    }
3506    _LIBCPP_INLINE_VISIBILITY
3507    void __release_shared() _NOEXCEPT {
3508      if (__shared_count::__release_shared())
3509        __release_weak();
3510    }
3511#endif
3512    void __release_weak() _NOEXCEPT;
3513    _LIBCPP_INLINE_VISIBILITY
3514    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
3515    __shared_weak_count* lock() _NOEXCEPT;
3516
3517    // Define the function out only if we build static libc++ without RTTI.
3518    // Otherwise we may break clients who need to compile their projects with
3519    // -fno-rtti and yet link against a libc++.dylib compiled
3520    // without -fno-rtti.
3521#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
3522    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3523#endif
3524private:
3525    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
3526};
3527
3528template <class _Tp, class _Dp, class _Alloc>
3529class __shared_ptr_pointer
3530    : public __shared_weak_count
3531{
3532    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
3533public:
3534    _LIBCPP_INLINE_VISIBILITY
3535    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
3536        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
3537
3538#ifndef _LIBCPP_NO_RTTI
3539    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3540#endif
3541
3542private:
3543    virtual void __on_zero_shared() _NOEXCEPT;
3544    virtual void __on_zero_shared_weak() _NOEXCEPT;
3545};
3546
3547#ifndef _LIBCPP_NO_RTTI
3548
3549template <class _Tp, class _Dp, class _Alloc>
3550const void*
3551__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
3552{
3553    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr;
3554}
3555
3556#endif  // _LIBCPP_NO_RTTI
3557
3558template <class _Tp, class _Dp, class _Alloc>
3559void
3560__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
3561{
3562    __data_.first().second()(__data_.first().first());
3563    __data_.first().second().~_Dp();
3564}
3565
3566template <class _Tp, class _Dp, class _Alloc>
3567void
3568__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3569{
3570    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
3571    typedef allocator_traits<_Al> _ATraits;
3572    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3573
3574    _Al __a(__data_.second());
3575    __data_.second().~_Alloc();
3576    __a.deallocate(_PTraits::pointer_to(*this), 1);
3577}
3578
3579template <class _Tp, class _Alloc>
3580class __shared_ptr_emplace
3581    : public __shared_weak_count
3582{
3583    __compressed_pair<_Alloc, _Tp> __data_;
3584public:
3585#ifndef _LIBCPP_HAS_NO_VARIADICS
3586
3587    _LIBCPP_INLINE_VISIBILITY
3588    __shared_ptr_emplace(_Alloc __a)
3589        :  __data_(_VSTD::move(__a)) {}
3590
3591    template <class ..._Args>
3592        _LIBCPP_INLINE_VISIBILITY
3593        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
3594            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
3595                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
3596
3597#else  // _LIBCPP_HAS_NO_VARIADICS
3598
3599    _LIBCPP_INLINE_VISIBILITY
3600    __shared_ptr_emplace(_Alloc __a)
3601        :  __data_(__a) {}
3602
3603    template <class _A0>
3604        _LIBCPP_INLINE_VISIBILITY
3605        __shared_ptr_emplace(_Alloc __a, _A0& __a0)
3606            :  __data_(__a, _Tp(__a0)) {}
3607
3608    template <class _A0, class _A1>
3609        _LIBCPP_INLINE_VISIBILITY
3610        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
3611            :  __data_(__a, _Tp(__a0, __a1)) {}
3612
3613    template <class _A0, class _A1, class _A2>
3614        _LIBCPP_INLINE_VISIBILITY
3615        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
3616            :  __data_(__a, _Tp(__a0, __a1, __a2)) {}
3617
3618#endif  // _LIBCPP_HAS_NO_VARIADICS
3619
3620private:
3621    virtual void __on_zero_shared() _NOEXCEPT;
3622    virtual void __on_zero_shared_weak() _NOEXCEPT;
3623public:
3624    _LIBCPP_INLINE_VISIBILITY
3625    _Tp* get() _NOEXCEPT {return _VSTD::addressof(__data_.second());}
3626};
3627
3628template <class _Tp, class _Alloc>
3629void
3630__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
3631{
3632    __data_.second().~_Tp();
3633}
3634
3635template <class _Tp, class _Alloc>
3636void
3637__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3638{
3639    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
3640    typedef allocator_traits<_Al> _ATraits;
3641    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3642    _Al __a(__data_.first());
3643    __data_.first().~_Alloc();
3644    __a.deallocate(_PTraits::pointer_to(*this), 1);
3645}
3646
3647struct __shared_ptr_dummy_rebind_allocator_type;
3648template <>
3649class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type>
3650{
3651public:
3652    template <class _Other>
3653    struct rebind
3654    {
3655        typedef allocator<_Other> other;
3656    };
3657};
3658
3659template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
3660
3661template<class _Tp>
3662class _LIBCPP_TEMPLATE_VIS shared_ptr
3663{
3664public:
3665    typedef _Tp element_type;
3666
3667#if _LIBCPP_STD_VER > 14
3668    typedef weak_ptr<_Tp> weak_type;
3669#endif
3670private:
3671    element_type*      __ptr_;
3672    __shared_weak_count* __cntrl_;
3673
3674    struct __nat {int __for_bool_;};
3675public:
3676    _LIBCPP_INLINE_VISIBILITY
3677    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
3678    _LIBCPP_INLINE_VISIBILITY
3679    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
3680    template<class _Yp>
3681        explicit shared_ptr(_Yp* __p,
3682                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3683    template<class _Yp, class _Dp>
3684        shared_ptr(_Yp* __p, _Dp __d,
3685                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3686    template<class _Yp, class _Dp, class _Alloc>
3687        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3688                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3689    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
3690    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
3691    template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
3692    _LIBCPP_INLINE_VISIBILITY
3693    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
3694    template<class _Yp>
3695        _LIBCPP_INLINE_VISIBILITY
3696        shared_ptr(const shared_ptr<_Yp>& __r,
3697                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
3698                       _NOEXCEPT;
3699#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3700    _LIBCPP_INLINE_VISIBILITY
3701    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
3702    template<class _Yp> _LIBCPP_INLINE_VISIBILITY  shared_ptr(shared_ptr<_Yp>&& __r,
3703                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
3704                       _NOEXCEPT;
3705#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3706    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
3707                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type= __nat());
3708#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3709#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3710    template<class _Yp>
3711        shared_ptr(auto_ptr<_Yp>&& __r,
3712                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3713#else
3714    template<class _Yp>
3715        shared_ptr(auto_ptr<_Yp> __r,
3716                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3717#endif
3718#endif
3719#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3720    template <class _Yp, class _Dp>
3721        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3722                   typename enable_if
3723                   <
3724                       !is_lvalue_reference<_Dp>::value &&
3725                       !is_array<_Yp>::value &&
3726                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3727                       __nat
3728                   >::type = __nat());
3729    template <class _Yp, class _Dp>
3730        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3731                   typename enable_if
3732                   <
3733                       is_lvalue_reference<_Dp>::value &&
3734                       !is_array<_Yp>::value &&
3735                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3736                       __nat
3737                   >::type = __nat());
3738#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3739    template <class _Yp, class _Dp>
3740        shared_ptr(unique_ptr<_Yp, _Dp>,
3741                   typename enable_if
3742                   <
3743                       !is_lvalue_reference<_Dp>::value &&
3744                       !is_array<_Yp>::value &&
3745                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3746                       __nat
3747                   >::type = __nat());
3748    template <class _Yp, class _Dp>
3749        shared_ptr(unique_ptr<_Yp, _Dp>,
3750                   typename enable_if
3751                   <
3752                       is_lvalue_reference<_Dp>::value &&
3753                       !is_array<_Yp>::value &&
3754                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3755                       __nat
3756                   >::type = __nat());
3757#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3758
3759    ~shared_ptr();
3760
3761    _LIBCPP_INLINE_VISIBILITY
3762    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
3763    template<class _Yp>
3764        typename enable_if
3765        <
3766            is_convertible<_Yp*, element_type*>::value,
3767            shared_ptr&
3768        >::type
3769        _LIBCPP_INLINE_VISIBILITY
3770        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
3771#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3772    _LIBCPP_INLINE_VISIBILITY
3773    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
3774    template<class _Yp>
3775        typename enable_if
3776        <
3777            is_convertible<_Yp*, element_type*>::value,
3778            shared_ptr<_Tp>&
3779        >::type
3780        _LIBCPP_INLINE_VISIBILITY
3781        operator=(shared_ptr<_Yp>&& __r);
3782#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3783    template<class _Yp>
3784        _LIBCPP_INLINE_VISIBILITY
3785        typename enable_if
3786        <
3787            !is_array<_Yp>::value &&
3788            is_convertible<_Yp*, element_type*>::value,
3789            shared_ptr
3790        >::type&
3791        operator=(auto_ptr<_Yp>&& __r);
3792#endif
3793#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3794#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3795    template<class _Yp>
3796        _LIBCPP_INLINE_VISIBILITY
3797        typename enable_if
3798        <
3799            !is_array<_Yp>::value &&
3800            is_convertible<_Yp*, element_type*>::value,
3801            shared_ptr&
3802        >::type
3803        operator=(auto_ptr<_Yp> __r);
3804#endif
3805#endif
3806    template <class _Yp, class _Dp>
3807        typename enable_if
3808        <
3809            !is_array<_Yp>::value &&
3810            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3811            shared_ptr&
3812        >::type
3813#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3814        _LIBCPP_INLINE_VISIBILITY
3815        operator=(unique_ptr<_Yp, _Dp>&& __r);
3816#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3817        _LIBCPP_INLINE_VISIBILITY
3818        operator=(unique_ptr<_Yp, _Dp> __r);
3819#endif
3820
3821    _LIBCPP_INLINE_VISIBILITY
3822    void swap(shared_ptr& __r) _NOEXCEPT;
3823    _LIBCPP_INLINE_VISIBILITY
3824    void reset() _NOEXCEPT;
3825    template<class _Yp>
3826        typename enable_if
3827        <
3828            is_convertible<_Yp*, element_type*>::value,
3829            void
3830        >::type
3831        _LIBCPP_INLINE_VISIBILITY
3832        reset(_Yp* __p);
3833    template<class _Yp, class _Dp>
3834        typename enable_if
3835        <
3836            is_convertible<_Yp*, element_type*>::value,
3837            void
3838        >::type
3839        _LIBCPP_INLINE_VISIBILITY
3840        reset(_Yp* __p, _Dp __d);
3841    template<class _Yp, class _Dp, class _Alloc>
3842        typename enable_if
3843        <
3844            is_convertible<_Yp*, element_type*>::value,
3845            void
3846        >::type
3847        _LIBCPP_INLINE_VISIBILITY
3848        reset(_Yp* __p, _Dp __d, _Alloc __a);
3849
3850    _LIBCPP_INLINE_VISIBILITY
3851    element_type* get() const _NOEXCEPT {return __ptr_;}
3852    _LIBCPP_INLINE_VISIBILITY
3853    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
3854        {return *__ptr_;}
3855    _LIBCPP_INLINE_VISIBILITY
3856    element_type* operator->() const _NOEXCEPT {return __ptr_;}
3857    _LIBCPP_INLINE_VISIBILITY
3858    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
3859    _LIBCPP_INLINE_VISIBILITY
3860    bool unique() const _NOEXCEPT {return use_count() == 1;}
3861    _LIBCPP_INLINE_VISIBILITY
3862    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
3863    template <class _Up>
3864        _LIBCPP_INLINE_VISIBILITY
3865        bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT
3866        {return __cntrl_ < __p.__cntrl_;}
3867    template <class _Up>
3868        _LIBCPP_INLINE_VISIBILITY
3869        bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT
3870        {return __cntrl_ < __p.__cntrl_;}
3871    _LIBCPP_INLINE_VISIBILITY
3872    bool
3873    __owner_equivalent(const shared_ptr& __p) const
3874        {return __cntrl_ == __p.__cntrl_;}
3875
3876#ifndef _LIBCPP_NO_RTTI
3877    template <class _Dp>
3878        _LIBCPP_INLINE_VISIBILITY
3879        _Dp* __get_deleter() const _NOEXCEPT
3880            {return static_cast<_Dp*>(__cntrl_
3881                    ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp)))
3882                      : nullptr);}
3883#endif  // _LIBCPP_NO_RTTI
3884
3885    template<class _Yp, class _CntrlBlk>
3886    static shared_ptr<_Tp>
3887    __create_with_control_block(_Yp* __p, _CntrlBlk* __cntrl)
3888    {
3889        shared_ptr<_Tp> __r;
3890        __r.__ptr_ = __p;
3891        __r.__cntrl_ = __cntrl;
3892        __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
3893        return __r;
3894    }
3895
3896    template<class _Alloc, class ..._Args>
3897        static
3898        shared_ptr<_Tp>
3899        allocate_shared(const _Alloc& __a, _Args&& ...__args);
3900
3901private:
3902    template <class _Yp, bool = is_function<_Yp>::value>
3903        struct __shared_ptr_default_allocator
3904        {
3905            typedef allocator<_Yp> type;
3906        };
3907
3908    template <class _Yp>
3909        struct __shared_ptr_default_allocator<_Yp, true>
3910        {
3911            typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
3912        };
3913
3914    template <class _Yp, class _OrigPtr>
3915        _LIBCPP_INLINE_VISIBILITY
3916        typename enable_if<is_convertible<_OrigPtr*,
3917                                          const enable_shared_from_this<_Yp>*
3918        >::value,
3919            void>::type
3920        __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
3921                           _OrigPtr* __ptr) _NOEXCEPT
3922        {
3923            typedef typename remove_cv<_Yp>::type _RawYp;
3924            if (__e && __e->__weak_this_.expired())
3925            {
3926                __e->__weak_this_ = shared_ptr<_RawYp>(*this,
3927                    const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
3928            }
3929        }
3930
3931    _LIBCPP_INLINE_VISIBILITY void __enable_weak_this(...) _NOEXCEPT {}
3932
3933    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
3934    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
3935};
3936
3937
3938template<class _Tp>
3939inline
3940_LIBCPP_CONSTEXPR
3941shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
3942    : __ptr_(0),
3943      __cntrl_(0)
3944{
3945}
3946
3947template<class _Tp>
3948inline
3949_LIBCPP_CONSTEXPR
3950shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
3951    : __ptr_(0),
3952      __cntrl_(0)
3953{
3954}
3955
3956template<class _Tp>
3957template<class _Yp>
3958shared_ptr<_Tp>::shared_ptr(_Yp* __p,
3959                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
3960    : __ptr_(__p)
3961{
3962    unique_ptr<_Yp> __hold(__p);
3963    typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3964    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, _AllocT > _CntrlBlk;
3965    __cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), _AllocT());
3966    __hold.release();
3967    __enable_weak_this(__p, __p);
3968}
3969
3970template<class _Tp>
3971template<class _Yp, class _Dp>
3972shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
3973                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
3974    : __ptr_(__p)
3975{
3976#ifndef _LIBCPP_NO_EXCEPTIONS
3977    try
3978    {
3979#endif  // _LIBCPP_NO_EXCEPTIONS
3980        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3981        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
3982        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
3983        __enable_weak_this(__p, __p);
3984#ifndef _LIBCPP_NO_EXCEPTIONS
3985    }
3986    catch (...)
3987    {
3988        __d(__p);
3989        throw;
3990    }
3991#endif  // _LIBCPP_NO_EXCEPTIONS
3992}
3993
3994template<class _Tp>
3995template<class _Dp>
3996shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
3997    : __ptr_(0)
3998{
3999#ifndef _LIBCPP_NO_EXCEPTIONS
4000    try
4001    {
4002#endif  // _LIBCPP_NO_EXCEPTIONS
4003        typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
4004        typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
4005        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
4006#ifndef _LIBCPP_NO_EXCEPTIONS
4007    }
4008    catch (...)
4009    {
4010        __d(__p);
4011        throw;
4012    }
4013#endif  // _LIBCPP_NO_EXCEPTIONS
4014}
4015
4016template<class _Tp>
4017template<class _Yp, class _Dp, class _Alloc>
4018shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
4019                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4020    : __ptr_(__p)
4021{
4022#ifndef _LIBCPP_NO_EXCEPTIONS
4023    try
4024    {
4025#endif  // _LIBCPP_NO_EXCEPTIONS
4026        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
4027        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4028        typedef __allocator_destructor<_A2> _D2;
4029        _A2 __a2(__a);
4030        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4031        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4032            _CntrlBlk(__p, __d, __a);
4033        __cntrl_ = _VSTD::addressof(*__hold2.release());
4034        __enable_weak_this(__p, __p);
4035#ifndef _LIBCPP_NO_EXCEPTIONS
4036    }
4037    catch (...)
4038    {
4039        __d(__p);
4040        throw;
4041    }
4042#endif  // _LIBCPP_NO_EXCEPTIONS
4043}
4044
4045template<class _Tp>
4046template<class _Dp, class _Alloc>
4047shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
4048    : __ptr_(0)
4049{
4050#ifndef _LIBCPP_NO_EXCEPTIONS
4051    try
4052    {
4053#endif  // _LIBCPP_NO_EXCEPTIONS
4054        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
4055        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4056        typedef __allocator_destructor<_A2> _D2;
4057        _A2 __a2(__a);
4058        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4059        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4060            _CntrlBlk(__p, __d, __a);
4061        __cntrl_ = _VSTD::addressof(*__hold2.release());
4062#ifndef _LIBCPP_NO_EXCEPTIONS
4063    }
4064    catch (...)
4065    {
4066        __d(__p);
4067        throw;
4068    }
4069#endif  // _LIBCPP_NO_EXCEPTIONS
4070}
4071
4072template<class _Tp>
4073template<class _Yp>
4074inline
4075shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
4076    : __ptr_(__p),
4077      __cntrl_(__r.__cntrl_)
4078{
4079    if (__cntrl_)
4080        __cntrl_->__add_shared();
4081}
4082
4083template<class _Tp>
4084inline
4085shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
4086    : __ptr_(__r.__ptr_),
4087      __cntrl_(__r.__cntrl_)
4088{
4089    if (__cntrl_)
4090        __cntrl_->__add_shared();
4091}
4092
4093template<class _Tp>
4094template<class _Yp>
4095inline
4096shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
4097                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4098         _NOEXCEPT
4099    : __ptr_(__r.__ptr_),
4100      __cntrl_(__r.__cntrl_)
4101{
4102    if (__cntrl_)
4103        __cntrl_->__add_shared();
4104}
4105
4106#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4107
4108template<class _Tp>
4109inline
4110shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
4111    : __ptr_(__r.__ptr_),
4112      __cntrl_(__r.__cntrl_)
4113{
4114    __r.__ptr_ = 0;
4115    __r.__cntrl_ = 0;
4116}
4117
4118template<class _Tp>
4119template<class _Yp>
4120inline
4121shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
4122                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4123         _NOEXCEPT
4124    : __ptr_(__r.__ptr_),
4125      __cntrl_(__r.__cntrl_)
4126{
4127    __r.__ptr_ = 0;
4128    __r.__cntrl_ = 0;
4129}
4130
4131#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4132
4133#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4134template<class _Tp>
4135template<class _Yp>
4136#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4137shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
4138#else
4139shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp> __r,
4140#endif
4141                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4142    : __ptr_(__r.get())
4143{
4144    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
4145    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
4146    __enable_weak_this(__r.get(), __r.get());
4147    __r.release();
4148}
4149#endif
4150
4151template<class _Tp>
4152template <class _Yp, class _Dp>
4153#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4154shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4155#else
4156shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4157#endif
4158                            typename enable_if
4159                            <
4160                                !is_lvalue_reference<_Dp>::value &&
4161                                !is_array<_Yp>::value &&
4162                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4163                                __nat
4164                            >::type)
4165    : __ptr_(__r.get())
4166{
4167#if _LIBCPP_STD_VER > 11
4168    if (__ptr_ == nullptr)
4169        __cntrl_ = nullptr;
4170    else
4171#endif
4172    {
4173        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4174        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
4175        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), _AllocT());
4176        __enable_weak_this(__r.get(), __r.get());
4177    }
4178    __r.release();
4179}
4180
4181template<class _Tp>
4182template <class _Yp, class _Dp>
4183#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4184shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4185#else
4186shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4187#endif
4188                            typename enable_if
4189                            <
4190                                is_lvalue_reference<_Dp>::value &&
4191                                !is_array<_Yp>::value &&
4192                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4193                                __nat
4194                            >::type)
4195    : __ptr_(__r.get())
4196{
4197#if _LIBCPP_STD_VER > 11
4198    if (__ptr_ == nullptr)
4199        __cntrl_ = nullptr;
4200    else
4201#endif
4202    {
4203        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4204        typedef __shared_ptr_pointer<_Yp*,
4205                                     reference_wrapper<typename remove_reference<_Dp>::type>,
4206                                     _AllocT > _CntrlBlk;
4207        __cntrl_ = new _CntrlBlk(__r.get(), ref(__r.get_deleter()), _AllocT());
4208        __enable_weak_this(__r.get(), __r.get());
4209    }
4210    __r.release();
4211}
4212
4213template<class _Tp>
4214template<class _Alloc, class ..._Args>
4215shared_ptr<_Tp>
4216shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _Args&& ...__args)
4217{
4218    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in allocate_shared" );
4219    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4220    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4221    typedef __allocator_destructor<_A2> _D2;
4222    _A2 __a2(__a);
4223    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4224    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4225        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
4226    shared_ptr<_Tp> __r;
4227    __r.__ptr_ = __hold2.get()->get();
4228    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4229    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4230    return __r;
4231}
4232
4233template<class _Tp>
4234shared_ptr<_Tp>::~shared_ptr()
4235{
4236    if (__cntrl_)
4237        __cntrl_->__release_shared();
4238}
4239
4240template<class _Tp>
4241inline
4242shared_ptr<_Tp>&
4243shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
4244{
4245    shared_ptr(__r).swap(*this);
4246    return *this;
4247}
4248
4249template<class _Tp>
4250template<class _Yp>
4251inline
4252typename enable_if
4253<
4254    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4255    shared_ptr<_Tp>&
4256>::type
4257shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
4258{
4259    shared_ptr(__r).swap(*this);
4260    return *this;
4261}
4262
4263#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4264
4265template<class _Tp>
4266inline
4267shared_ptr<_Tp>&
4268shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
4269{
4270    shared_ptr(_VSTD::move(__r)).swap(*this);
4271    return *this;
4272}
4273
4274template<class _Tp>
4275template<class _Yp>
4276inline
4277typename enable_if
4278<
4279    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4280    shared_ptr<_Tp>&
4281>::type
4282shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
4283{
4284    shared_ptr(_VSTD::move(__r)).swap(*this);
4285    return *this;
4286}
4287
4288#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4289template<class _Tp>
4290template<class _Yp>
4291inline
4292typename enable_if
4293<
4294    !is_array<_Yp>::value &&
4295    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4296    shared_ptr<_Tp>
4297>::type&
4298shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
4299{
4300    shared_ptr(_VSTD::move(__r)).swap(*this);
4301    return *this;
4302}
4303#endif
4304
4305template<class _Tp>
4306template <class _Yp, class _Dp>
4307inline
4308typename enable_if
4309<
4310    !is_array<_Yp>::value &&
4311    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4312                   typename shared_ptr<_Tp>::element_type*>::value,
4313    shared_ptr<_Tp>&
4314>::type
4315shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
4316{
4317    shared_ptr(_VSTD::move(__r)).swap(*this);
4318    return *this;
4319}
4320
4321#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4322
4323#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4324template<class _Tp>
4325template<class _Yp>
4326inline _LIBCPP_INLINE_VISIBILITY
4327typename enable_if
4328<
4329    !is_array<_Yp>::value &&
4330    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4331    shared_ptr<_Tp>&
4332>::type
4333shared_ptr<_Tp>::operator=(auto_ptr<_Yp> __r)
4334{
4335    shared_ptr(__r).swap(*this);
4336    return *this;
4337}
4338#endif
4339
4340template<class _Tp>
4341template <class _Yp, class _Dp>
4342inline _LIBCPP_INLINE_VISIBILITY
4343typename enable_if
4344<
4345    !is_array<_Yp>::value &&
4346    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4347                   typename shared_ptr<_Tp>::element_type*>::value,
4348    shared_ptr<_Tp>&
4349>::type
4350shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp> __r)
4351{
4352    shared_ptr(_VSTD::move(__r)).swap(*this);
4353    return *this;
4354}
4355
4356#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4357
4358template<class _Tp>
4359inline
4360void
4361shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
4362{
4363    _VSTD::swap(__ptr_, __r.__ptr_);
4364    _VSTD::swap(__cntrl_, __r.__cntrl_);
4365}
4366
4367template<class _Tp>
4368inline
4369void
4370shared_ptr<_Tp>::reset() _NOEXCEPT
4371{
4372    shared_ptr().swap(*this);
4373}
4374
4375template<class _Tp>
4376template<class _Yp>
4377inline
4378typename enable_if
4379<
4380    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4381    void
4382>::type
4383shared_ptr<_Tp>::reset(_Yp* __p)
4384{
4385    shared_ptr(__p).swap(*this);
4386}
4387
4388template<class _Tp>
4389template<class _Yp, class _Dp>
4390inline
4391typename enable_if
4392<
4393    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4394    void
4395>::type
4396shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
4397{
4398    shared_ptr(__p, __d).swap(*this);
4399}
4400
4401template<class _Tp>
4402template<class _Yp, class _Dp, class _Alloc>
4403inline
4404typename enable_if
4405<
4406    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4407    void
4408>::type
4409shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
4410{
4411    shared_ptr(__p, __d, __a).swap(*this);
4412}
4413
4414template<class _Tp, class ..._Args>
4415inline _LIBCPP_INLINE_VISIBILITY
4416typename enable_if
4417<
4418    !is_array<_Tp>::value,
4419    shared_ptr<_Tp>
4420>::type
4421make_shared(_Args&& ...__args)
4422{
4423    static_assert(is_constructible<_Tp, _Args...>::value, "Can't construct object in make_shared");
4424    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4425    typedef allocator<_CntrlBlk> _A2;
4426    typedef __allocator_destructor<_A2> _D2;
4427
4428    _A2 __a2;
4429    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4430    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
4431
4432    _Tp *__ptr = __hold2.get()->get();
4433    return shared_ptr<_Tp>::__create_with_control_block(__ptr, __hold2.release());
4434}
4435
4436template<class _Tp, class _Alloc, class ..._Args>
4437inline _LIBCPP_INLINE_VISIBILITY
4438typename enable_if
4439<
4440    !is_array<_Tp>::value,
4441    shared_ptr<_Tp>
4442>::type
4443allocate_shared(const _Alloc& __a, _Args&& ...__args)
4444{
4445    return shared_ptr<_Tp>::allocate_shared(__a, _VSTD::forward<_Args>(__args)...);
4446}
4447
4448template<class _Tp, class _Up>
4449inline _LIBCPP_INLINE_VISIBILITY
4450bool
4451operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4452{
4453    return __x.get() == __y.get();
4454}
4455
4456template<class _Tp, class _Up>
4457inline _LIBCPP_INLINE_VISIBILITY
4458bool
4459operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4460{
4461    return !(__x == __y);
4462}
4463
4464template<class _Tp, class _Up>
4465inline _LIBCPP_INLINE_VISIBILITY
4466bool
4467operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4468{
4469#if _LIBCPP_STD_VER <= 11
4470    typedef typename common_type<_Tp*, _Up*>::type _Vp;
4471    return less<_Vp>()(__x.get(), __y.get());
4472#else
4473    return less<>()(__x.get(), __y.get());
4474#endif
4475
4476}
4477
4478template<class _Tp, class _Up>
4479inline _LIBCPP_INLINE_VISIBILITY
4480bool
4481operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4482{
4483    return __y < __x;
4484}
4485
4486template<class _Tp, class _Up>
4487inline _LIBCPP_INLINE_VISIBILITY
4488bool
4489operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4490{
4491    return !(__y < __x);
4492}
4493
4494template<class _Tp, class _Up>
4495inline _LIBCPP_INLINE_VISIBILITY
4496bool
4497operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4498{
4499    return !(__x < __y);
4500}
4501
4502template<class _Tp>
4503inline _LIBCPP_INLINE_VISIBILITY
4504bool
4505operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4506{
4507    return !__x;
4508}
4509
4510template<class _Tp>
4511inline _LIBCPP_INLINE_VISIBILITY
4512bool
4513operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4514{
4515    return !__x;
4516}
4517
4518template<class _Tp>
4519inline _LIBCPP_INLINE_VISIBILITY
4520bool
4521operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4522{
4523    return static_cast<bool>(__x);
4524}
4525
4526template<class _Tp>
4527inline _LIBCPP_INLINE_VISIBILITY
4528bool
4529operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4530{
4531    return static_cast<bool>(__x);
4532}
4533
4534template<class _Tp>
4535inline _LIBCPP_INLINE_VISIBILITY
4536bool
4537operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4538{
4539    return less<_Tp*>()(__x.get(), nullptr);
4540}
4541
4542template<class _Tp>
4543inline _LIBCPP_INLINE_VISIBILITY
4544bool
4545operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4546{
4547    return less<_Tp*>()(nullptr, __x.get());
4548}
4549
4550template<class _Tp>
4551inline _LIBCPP_INLINE_VISIBILITY
4552bool
4553operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4554{
4555    return nullptr < __x;
4556}
4557
4558template<class _Tp>
4559inline _LIBCPP_INLINE_VISIBILITY
4560bool
4561operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4562{
4563    return __x < nullptr;
4564}
4565
4566template<class _Tp>
4567inline _LIBCPP_INLINE_VISIBILITY
4568bool
4569operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4570{
4571    return !(nullptr < __x);
4572}
4573
4574template<class _Tp>
4575inline _LIBCPP_INLINE_VISIBILITY
4576bool
4577operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4578{
4579    return !(__x < nullptr);
4580}
4581
4582template<class _Tp>
4583inline _LIBCPP_INLINE_VISIBILITY
4584bool
4585operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4586{
4587    return !(__x < nullptr);
4588}
4589
4590template<class _Tp>
4591inline _LIBCPP_INLINE_VISIBILITY
4592bool
4593operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4594{
4595    return !(nullptr < __x);
4596}
4597
4598template<class _Tp>
4599inline _LIBCPP_INLINE_VISIBILITY
4600void
4601swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
4602{
4603    __x.swap(__y);
4604}
4605
4606template<class _Tp, class _Up>
4607inline _LIBCPP_INLINE_VISIBILITY
4608typename enable_if
4609<
4610    !is_array<_Tp>::value && !is_array<_Up>::value,
4611    shared_ptr<_Tp>
4612>::type
4613static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4614{
4615    return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get()));
4616}
4617
4618template<class _Tp, class _Up>
4619inline _LIBCPP_INLINE_VISIBILITY
4620typename enable_if
4621<
4622    !is_array<_Tp>::value && !is_array<_Up>::value,
4623    shared_ptr<_Tp>
4624>::type
4625dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4626{
4627    _Tp* __p = dynamic_cast<_Tp*>(__r.get());
4628    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
4629}
4630
4631template<class _Tp, class _Up>
4632typename enable_if
4633<
4634    is_array<_Tp>::value == is_array<_Up>::value,
4635    shared_ptr<_Tp>
4636>::type
4637const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4638{
4639    typedef typename remove_extent<_Tp>::type _RTp;
4640    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
4641}
4642
4643#ifndef _LIBCPP_NO_RTTI
4644
4645template<class _Dp, class _Tp>
4646inline _LIBCPP_INLINE_VISIBILITY
4647_Dp*
4648get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
4649{
4650    return __p.template __get_deleter<_Dp>();
4651}
4652
4653#endif  // _LIBCPP_NO_RTTI
4654
4655template<class _Tp>
4656class _LIBCPP_TEMPLATE_VIS weak_ptr
4657{
4658public:
4659    typedef _Tp element_type;
4660private:
4661    element_type*        __ptr_;
4662    __shared_weak_count* __cntrl_;
4663
4664public:
4665    _LIBCPP_INLINE_VISIBILITY
4666    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
4667    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r,
4668                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4669                        _NOEXCEPT;
4670    _LIBCPP_INLINE_VISIBILITY
4671    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
4672    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r,
4673                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4674                         _NOEXCEPT;
4675
4676#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4677    _LIBCPP_INLINE_VISIBILITY
4678    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
4679    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r,
4680                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4681                         _NOEXCEPT;
4682#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4683    ~weak_ptr();
4684
4685    _LIBCPP_INLINE_VISIBILITY
4686    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
4687    template<class _Yp>
4688        typename enable_if
4689        <
4690            is_convertible<_Yp*, element_type*>::value,
4691            weak_ptr&
4692        >::type
4693        _LIBCPP_INLINE_VISIBILITY
4694        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
4695
4696#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4697
4698    _LIBCPP_INLINE_VISIBILITY
4699    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
4700    template<class _Yp>
4701        typename enable_if
4702        <
4703            is_convertible<_Yp*, element_type*>::value,
4704            weak_ptr&
4705        >::type
4706        _LIBCPP_INLINE_VISIBILITY
4707        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
4708
4709#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4710
4711    template<class _Yp>
4712        typename enable_if
4713        <
4714            is_convertible<_Yp*, element_type*>::value,
4715            weak_ptr&
4716        >::type
4717        _LIBCPP_INLINE_VISIBILITY
4718        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
4719
4720    _LIBCPP_INLINE_VISIBILITY
4721    void swap(weak_ptr& __r) _NOEXCEPT;
4722    _LIBCPP_INLINE_VISIBILITY
4723    void reset() _NOEXCEPT;
4724
4725    _LIBCPP_INLINE_VISIBILITY
4726    long use_count() const _NOEXCEPT
4727        {return __cntrl_ ? __cntrl_->use_count() : 0;}
4728    _LIBCPP_INLINE_VISIBILITY
4729    bool expired() const _NOEXCEPT
4730        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
4731    shared_ptr<_Tp> lock() const _NOEXCEPT;
4732    template<class _Up>
4733        _LIBCPP_INLINE_VISIBILITY
4734        bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT
4735        {return __cntrl_ < __r.__cntrl_;}
4736    template<class _Up>
4737        _LIBCPP_INLINE_VISIBILITY
4738        bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT
4739        {return __cntrl_ < __r.__cntrl_;}
4740
4741    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
4742    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
4743};
4744
4745template<class _Tp>
4746inline
4747_LIBCPP_CONSTEXPR
4748weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
4749    : __ptr_(0),
4750      __cntrl_(0)
4751{
4752}
4753
4754template<class _Tp>
4755inline
4756weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
4757    : __ptr_(__r.__ptr_),
4758      __cntrl_(__r.__cntrl_)
4759{
4760    if (__cntrl_)
4761        __cntrl_->__add_weak();
4762}
4763
4764template<class _Tp>
4765template<class _Yp>
4766inline
4767weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
4768                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4769                         _NOEXCEPT
4770    : __ptr_(__r.__ptr_),
4771      __cntrl_(__r.__cntrl_)
4772{
4773    if (__cntrl_)
4774        __cntrl_->__add_weak();
4775}
4776
4777template<class _Tp>
4778template<class _Yp>
4779inline
4780weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
4781                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4782         _NOEXCEPT
4783    : __ptr_(__r.__ptr_),
4784      __cntrl_(__r.__cntrl_)
4785{
4786    if (__cntrl_)
4787        __cntrl_->__add_weak();
4788}
4789
4790#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4791
4792template<class _Tp>
4793inline
4794weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
4795    : __ptr_(__r.__ptr_),
4796      __cntrl_(__r.__cntrl_)
4797{
4798    __r.__ptr_ = 0;
4799    __r.__cntrl_ = 0;
4800}
4801
4802template<class _Tp>
4803template<class _Yp>
4804inline
4805weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
4806                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4807         _NOEXCEPT
4808    : __ptr_(__r.__ptr_),
4809      __cntrl_(__r.__cntrl_)
4810{
4811    __r.__ptr_ = 0;
4812    __r.__cntrl_ = 0;
4813}
4814
4815#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4816
4817template<class _Tp>
4818weak_ptr<_Tp>::~weak_ptr()
4819{
4820    if (__cntrl_)
4821        __cntrl_->__release_weak();
4822}
4823
4824template<class _Tp>
4825inline
4826weak_ptr<_Tp>&
4827weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
4828{
4829    weak_ptr(__r).swap(*this);
4830    return *this;
4831}
4832
4833template<class _Tp>
4834template<class _Yp>
4835inline
4836typename enable_if
4837<
4838    is_convertible<_Yp*, _Tp*>::value,
4839    weak_ptr<_Tp>&
4840>::type
4841weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
4842{
4843    weak_ptr(__r).swap(*this);
4844    return *this;
4845}
4846
4847#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4848
4849template<class _Tp>
4850inline
4851weak_ptr<_Tp>&
4852weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
4853{
4854    weak_ptr(_VSTD::move(__r)).swap(*this);
4855    return *this;
4856}
4857
4858template<class _Tp>
4859template<class _Yp>
4860inline
4861typename enable_if
4862<
4863    is_convertible<_Yp*, _Tp*>::value,
4864    weak_ptr<_Tp>&
4865>::type
4866weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
4867{
4868    weak_ptr(_VSTD::move(__r)).swap(*this);
4869    return *this;
4870}
4871
4872#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4873
4874template<class _Tp>
4875template<class _Yp>
4876inline
4877typename enable_if
4878<
4879    is_convertible<_Yp*, _Tp*>::value,
4880    weak_ptr<_Tp>&
4881>::type
4882weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
4883{
4884    weak_ptr(__r).swap(*this);
4885    return *this;
4886}
4887
4888template<class _Tp>
4889inline
4890void
4891weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
4892{
4893    _VSTD::swap(__ptr_, __r.__ptr_);
4894    _VSTD::swap(__cntrl_, __r.__cntrl_);
4895}
4896
4897template<class _Tp>
4898inline _LIBCPP_INLINE_VISIBILITY
4899void
4900swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
4901{
4902    __x.swap(__y);
4903}
4904
4905template<class _Tp>
4906inline
4907void
4908weak_ptr<_Tp>::reset() _NOEXCEPT
4909{
4910    weak_ptr().swap(*this);
4911}
4912
4913template<class _Tp>
4914template<class _Yp>
4915shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
4916                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4917    : __ptr_(__r.__ptr_),
4918      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
4919{
4920    if (__cntrl_ == 0)
4921        __throw_bad_weak_ptr();
4922}
4923
4924template<class _Tp>
4925shared_ptr<_Tp>
4926weak_ptr<_Tp>::lock() const _NOEXCEPT
4927{
4928    shared_ptr<_Tp> __r;
4929    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
4930    if (__r.__cntrl_)
4931        __r.__ptr_ = __ptr_;
4932    return __r;
4933}
4934
4935#if _LIBCPP_STD_VER > 14
4936template <class _Tp = void> struct owner_less;
4937#else
4938template <class _Tp> struct owner_less;
4939#endif
4940
4941template <class _Tp>
4942struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> >
4943    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
4944{
4945    typedef bool result_type;
4946    _LIBCPP_INLINE_VISIBILITY
4947    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4948        {return __x.owner_before(__y);}
4949    _LIBCPP_INLINE_VISIBILITY
4950    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4951        {return __x.owner_before(__y);}
4952    _LIBCPP_INLINE_VISIBILITY
4953    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4954        {return __x.owner_before(__y);}
4955};
4956
4957template <class _Tp>
4958struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> >
4959    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
4960{
4961    typedef bool result_type;
4962    _LIBCPP_INLINE_VISIBILITY
4963    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4964        {return __x.owner_before(__y);}
4965    _LIBCPP_INLINE_VISIBILITY
4966    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4967        {return __x.owner_before(__y);}
4968    _LIBCPP_INLINE_VISIBILITY
4969    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4970        {return __x.owner_before(__y);}
4971};
4972
4973#if _LIBCPP_STD_VER > 14
4974template <>
4975struct _LIBCPP_TEMPLATE_VIS owner_less<void>
4976{
4977    template <class _Tp, class _Up>
4978    _LIBCPP_INLINE_VISIBILITY
4979    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
4980        {return __x.owner_before(__y);}
4981    template <class _Tp, class _Up>
4982    _LIBCPP_INLINE_VISIBILITY
4983    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
4984        {return __x.owner_before(__y);}
4985    template <class _Tp, class _Up>
4986    _LIBCPP_INLINE_VISIBILITY
4987    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
4988        {return __x.owner_before(__y);}
4989    template <class _Tp, class _Up>
4990    _LIBCPP_INLINE_VISIBILITY
4991    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
4992        {return __x.owner_before(__y);}
4993    typedef void is_transparent;
4994};
4995#endif
4996
4997template<class _Tp>
4998class _LIBCPP_TEMPLATE_VIS enable_shared_from_this
4999{
5000    mutable weak_ptr<_Tp> __weak_this_;
5001protected:
5002    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
5003    enable_shared_from_this() _NOEXCEPT {}
5004    _LIBCPP_INLINE_VISIBILITY
5005    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
5006    _LIBCPP_INLINE_VISIBILITY
5007    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
5008        {return *this;}
5009    _LIBCPP_INLINE_VISIBILITY
5010    ~enable_shared_from_this() {}
5011public:
5012    _LIBCPP_INLINE_VISIBILITY
5013    shared_ptr<_Tp> shared_from_this()
5014        {return shared_ptr<_Tp>(__weak_this_);}
5015    _LIBCPP_INLINE_VISIBILITY
5016    shared_ptr<_Tp const> shared_from_this() const
5017        {return shared_ptr<const _Tp>(__weak_this_);}
5018
5019#if _LIBCPP_STD_VER > 14
5020    _LIBCPP_INLINE_VISIBILITY
5021    weak_ptr<_Tp> weak_from_this() _NOEXCEPT
5022       { return __weak_this_; }
5023
5024    _LIBCPP_INLINE_VISIBILITY
5025    weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT
5026        { return __weak_this_; }
5027#endif // _LIBCPP_STD_VER > 14
5028
5029    template <class _Up> friend class shared_ptr;
5030};
5031
5032template <class _Tp>
5033struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> >
5034{
5035    typedef shared_ptr<_Tp>      argument_type;
5036    typedef size_t               result_type;
5037
5038    _LIBCPP_INLINE_VISIBILITY
5039    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
5040    {
5041        return hash<_Tp*>()(__ptr.get());
5042    }
5043};
5044
5045template<class _CharT, class _Traits, class _Yp>
5046inline _LIBCPP_INLINE_VISIBILITY
5047basic_ostream<_CharT, _Traits>&
5048operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
5049
5050
5051#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
5052
5053class _LIBCPP_TYPE_VIS __sp_mut
5054{
5055    void* __lx;
5056public:
5057    void lock() _NOEXCEPT;
5058    void unlock() _NOEXCEPT;
5059
5060private:
5061    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
5062    __sp_mut(const __sp_mut&);
5063    __sp_mut& operator=(const __sp_mut&);
5064
5065    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
5066};
5067
5068_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5069__sp_mut& __get_sp_mut(const void*);
5070
5071template <class _Tp>
5072inline _LIBCPP_INLINE_VISIBILITY
5073bool
5074atomic_is_lock_free(const shared_ptr<_Tp>*)
5075{
5076    return false;
5077}
5078
5079template <class _Tp>
5080_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5081shared_ptr<_Tp>
5082atomic_load(const shared_ptr<_Tp>* __p)
5083{
5084    __sp_mut& __m = __get_sp_mut(__p);
5085    __m.lock();
5086    shared_ptr<_Tp> __q = *__p;
5087    __m.unlock();
5088    return __q;
5089}
5090
5091template <class _Tp>
5092inline _LIBCPP_INLINE_VISIBILITY
5093_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5094shared_ptr<_Tp>
5095atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
5096{
5097    return atomic_load(__p);
5098}
5099
5100template <class _Tp>
5101_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5102void
5103atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5104{
5105    __sp_mut& __m = __get_sp_mut(__p);
5106    __m.lock();
5107    __p->swap(__r);
5108    __m.unlock();
5109}
5110
5111template <class _Tp>
5112inline _LIBCPP_INLINE_VISIBILITY
5113_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5114void
5115atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5116{
5117    atomic_store(__p, __r);
5118}
5119
5120template <class _Tp>
5121_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5122shared_ptr<_Tp>
5123atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5124{
5125    __sp_mut& __m = __get_sp_mut(__p);
5126    __m.lock();
5127    __p->swap(__r);
5128    __m.unlock();
5129    return __r;
5130}
5131
5132template <class _Tp>
5133inline _LIBCPP_INLINE_VISIBILITY
5134_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5135shared_ptr<_Tp>
5136atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5137{
5138    return atomic_exchange(__p, __r);
5139}
5140
5141template <class _Tp>
5142_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5143bool
5144atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5145{
5146    shared_ptr<_Tp> __temp;
5147    __sp_mut& __m = __get_sp_mut(__p);
5148    __m.lock();
5149    if (__p->__owner_equivalent(*__v))
5150    {
5151        _VSTD::swap(__temp, *__p);
5152        *__p = __w;
5153        __m.unlock();
5154        return true;
5155    }
5156    _VSTD::swap(__temp, *__v);
5157    *__v = *__p;
5158    __m.unlock();
5159    return false;
5160}
5161
5162template <class _Tp>
5163inline _LIBCPP_INLINE_VISIBILITY
5164_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5165bool
5166atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5167{
5168    return atomic_compare_exchange_strong(__p, __v, __w);
5169}
5170
5171template <class _Tp>
5172inline _LIBCPP_INLINE_VISIBILITY
5173_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5174bool
5175atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5176                                        shared_ptr<_Tp> __w, memory_order, memory_order)
5177{
5178    return atomic_compare_exchange_strong(__p, __v, __w);
5179}
5180
5181template <class _Tp>
5182inline _LIBCPP_INLINE_VISIBILITY
5183_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5184bool
5185atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5186                                      shared_ptr<_Tp> __w, memory_order, memory_order)
5187{
5188    return atomic_compare_exchange_weak(__p, __v, __w);
5189}
5190
5191#endif  // !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
5192
5193//enum class
5194#if defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE)
5195# ifndef _LIBCPP_CXX03_LANG
5196enum class pointer_safety : unsigned char {
5197  relaxed,
5198  preferred,
5199  strict
5200};
5201# endif
5202#else
5203struct _LIBCPP_TYPE_VIS pointer_safety
5204{
5205    enum __lx
5206    {
5207        relaxed,
5208        preferred,
5209        strict
5210    };
5211
5212    __lx __v_;
5213
5214    _LIBCPP_INLINE_VISIBILITY
5215    pointer_safety() : __v_() {}
5216
5217    _LIBCPP_INLINE_VISIBILITY
5218    pointer_safety(__lx __v) : __v_(__v) {}
5219    _LIBCPP_INLINE_VISIBILITY
5220    operator int() const {return __v_;}
5221};
5222#endif
5223
5224#if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) && \
5225    defined(_LIBCPP_BUILDING_LIBRARY)
5226_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
5227#else
5228// This function is only offered in C++03 under ABI v1.
5229# if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) || !defined(_LIBCPP_CXX03_LANG)
5230inline _LIBCPP_INLINE_VISIBILITY
5231pointer_safety get_pointer_safety() _NOEXCEPT {
5232  return pointer_safety::relaxed;
5233}
5234# endif
5235#endif
5236
5237
5238_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
5239_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
5240_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
5241_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
5242
5243template <class _Tp>
5244inline _LIBCPP_INLINE_VISIBILITY
5245_Tp*
5246undeclare_reachable(_Tp* __p)
5247{
5248    return static_cast<_Tp*>(__undeclare_reachable(__p));
5249}
5250
5251_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
5252
5253// --- Helper for container swap --
5254template <typename _Alloc>
5255inline _LIBCPP_INLINE_VISIBILITY
5256void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
5257#if _LIBCPP_STD_VER >= 14
5258    _NOEXCEPT
5259#else
5260    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5261#endif
5262{
5263    __swap_allocator(__a1, __a2,
5264      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
5265}
5266
5267template <typename _Alloc>
5268_LIBCPP_INLINE_VISIBILITY
5269void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
5270#if _LIBCPP_STD_VER >= 14
5271    _NOEXCEPT
5272#else
5273    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5274#endif
5275{
5276    using _VSTD::swap;
5277    swap(__a1, __a2);
5278}
5279
5280template <typename _Alloc>
5281inline _LIBCPP_INLINE_VISIBILITY
5282void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
5283
5284template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
5285struct __noexcept_move_assign_container : public integral_constant<bool,
5286    _Traits::propagate_on_container_move_assignment::value
5287#if _LIBCPP_STD_VER > 14
5288        || _Traits::is_always_equal::value
5289#else
5290        && is_nothrow_move_assignable<_Alloc>::value
5291#endif
5292    > {};
5293
5294
5295#ifndef _LIBCPP_HAS_NO_VARIADICS
5296template <class _Tp, class _Alloc>
5297struct __temp_value {
5298    typedef allocator_traits<_Alloc> _Traits;
5299
5300    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
5301    _Alloc &__a;
5302
5303    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
5304    _Tp &   get() { return *__addr(); }
5305
5306    template<class... _Args>
5307    _LIBCPP_NO_CFI
5308    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
5309      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
5310                         _VSTD::forward<_Args>(__args)...);
5311    }
5312
5313    ~__temp_value() { _Traits::destroy(__a, __addr()); }
5314    };
5315#endif
5316
5317template<typename _Alloc, typename = void, typename = void>
5318struct __is_allocator : false_type {};
5319
5320template<typename _Alloc>
5321struct __is_allocator<_Alloc,
5322       typename __void_t<typename _Alloc::value_type>::type,
5323       typename __void_t<decltype(_VSTD::declval<_Alloc&>().allocate(size_t(0)))>::type
5324     >
5325   : true_type {};
5326
5327// __builtin_new_allocator -- A non-templated helper for allocating and
5328// deallocating memory using __builtin_operator_new and
5329// __builtin_operator_delete. It should be used in preference to
5330// `std::allocator<T>` to avoid additional instantiations.
5331struct __builtin_new_allocator {
5332  struct __builtin_new_deleter {
5333    typedef void* pointer_type;
5334
5335    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
5336        : __size_(__size), __align_(__align) {}
5337
5338    void operator()(void* p) const _NOEXCEPT {
5339        std::__libcpp_deallocate(p, __size_, __align_);
5340    }
5341
5342   private:
5343    size_t __size_;
5344    size_t __align_;
5345  };
5346
5347  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
5348
5349  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
5350      return __holder_t(std::__libcpp_allocate(__s, __align),
5351                     __builtin_new_deleter(__s, __align));
5352  }
5353
5354  static void __deallocate_bytes(void* __p, size_t __s,
5355                                 size_t __align) _NOEXCEPT {
5356      std::__libcpp_deallocate(__p, __s, __align);
5357  }
5358
5359  template <class _Tp>
5360  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5361  static __holder_t __allocate_type(size_t __n) {
5362      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5363  }
5364
5365  template <class _Tp>
5366  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5367  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
5368      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5369  }
5370};
5371
5372
5373_LIBCPP_END_NAMESPACE_STD
5374
5375_LIBCPP_POP_MACROS
5376
5377#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
5378#   include <__pstl_memory>
5379#endif
5380
5381#endif  // _LIBCPP_MEMORY
5382