xref: /freebsd/contrib/llvm-project/libcxx/include/memory (revision cd0d51baaa4509a1db83251a601d34404d20c990)
1// -*- C++ -*-
2//===-------------------------- memory ------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_MEMORY
11#define _LIBCPP_MEMORY
12
13/*
14    memory synopsis
15
16namespace std
17{
18
19struct allocator_arg_t { };
20inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();
21
22template <class T, class Alloc> struct uses_allocator;
23
24template <class Ptr>
25struct pointer_traits
26{
27    typedef Ptr pointer;
28    typedef <details> element_type;
29    typedef <details> difference_type;
30
31    template <class U> using rebind = <details>;
32
33    static pointer pointer_to(<details>);
34};
35
36template <class T>
37struct pointer_traits<T*>
38{
39    typedef T* pointer;
40    typedef T element_type;
41    typedef ptrdiff_t difference_type;
42
43    template <class U> using rebind = U*;
44
45    static pointer pointer_to(<details>) noexcept; // constexpr in C++20
46};
47
48template <class T> constexpr T* to_address(T* p) noexcept; // C++20
49template <class Ptr> auto to_address(const Ptr& p) noexcept; // C++20
50
51template <class Alloc>
52struct allocator_traits
53{
54    typedef Alloc                        allocator_type;
55    typedef typename allocator_type::value_type
56                                         value_type;
57
58    typedef Alloc::pointer | value_type* pointer;
59    typedef Alloc::const_pointer
60          | pointer_traits<pointer>::rebind<const value_type>
61                                         const_pointer;
62    typedef Alloc::void_pointer
63          | pointer_traits<pointer>::rebind<void>
64                                         void_pointer;
65    typedef Alloc::const_void_pointer
66          | pointer_traits<pointer>::rebind<const void>
67                                         const_void_pointer;
68    typedef Alloc::difference_type
69          | pointer_traits<pointer>::difference_type
70                                         difference_type;
71    typedef Alloc::size_type
72          | make_unsigned<difference_type>::type
73                                         size_type;
74    typedef Alloc::propagate_on_container_copy_assignment
75          | false_type                   propagate_on_container_copy_assignment;
76    typedef Alloc::propagate_on_container_move_assignment
77          | false_type                   propagate_on_container_move_assignment;
78    typedef Alloc::propagate_on_container_swap
79          | false_type                   propagate_on_container_swap;
80    typedef Alloc::is_always_equal
81          | is_empty                     is_always_equal;
82
83    template <class T> using rebind_alloc  = Alloc::rebind<U>::other | Alloc<T, Args...>;
84    template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
85
86    static pointer allocate(allocator_type& a, size_type n);                          // [[nodiscard]] in C++20
87    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint); // [[nodiscard]] in C++20
88
89    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept;
90
91    template <class T, class... Args>
92        static void construct(allocator_type& a, T* p, Args&&... args);
93
94    template <class T>
95        static void destroy(allocator_type& a, T* p);
96
97    static size_type max_size(const allocator_type& a); // noexcept in C++14
98
99    static allocator_type
100        select_on_container_copy_construction(const allocator_type& a);
101};
102
103template <>
104class allocator<void>
105{
106public:
107    typedef void*                                 pointer;
108    typedef const void*                           const_pointer;
109    typedef void                                  value_type;
110
111    template <class _Up> struct rebind {typedef allocator<_Up> other;};
112};
113
114template <class T>
115class allocator
116{
117public:
118    typedef size_t                                size_type;
119    typedef ptrdiff_t                             difference_type;
120    typedef T*                                    pointer;
121    typedef const T*                              const_pointer;
122    typedef typename add_lvalue_reference<T>::type       reference;
123    typedef typename add_lvalue_reference<const T>::type const_reference;
124    typedef T                                     value_type;
125
126    template <class U> struct rebind {typedef allocator<U> other;};
127
128    constexpr allocator() noexcept;                      // constexpr in C++20
129    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
130    template <class U>
131      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
132    ~allocator();
133    pointer address(reference x) const noexcept;
134    const_pointer address(const_reference x) const noexcept;
135    pointer allocate(size_type, allocator<void>::const_pointer hint = 0);
136    void deallocate(pointer p, size_type n) noexcept;
137    size_type max_size() const noexcept;
138    template<class U, class... Args>
139        void construct(U* p, Args&&... args);
140    template <class U>
141        void destroy(U* p);
142};
143
144template <class T, class U>
145bool operator==(const allocator<T>&, const allocator<U>&) noexcept;
146
147template <class T, class U>
148bool operator!=(const allocator<T>&, const allocator<U>&) noexcept;
149
150template <class OutputIterator, class T>
151class raw_storage_iterator
152    : public iterator<output_iterator_tag,
153                      T,                               // purposefully not C++03
154                      ptrdiff_t,                       // purposefully not C++03
155                      T*,                              // purposefully not C++03
156                      raw_storage_iterator&>           // purposefully not C++03
157{
158public:
159    explicit raw_storage_iterator(OutputIterator x);
160    raw_storage_iterator& operator*();
161    raw_storage_iterator& operator=(const T& element);
162    raw_storage_iterator& operator++();
163    raw_storage_iterator  operator++(int);
164};
165
166template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
167template <class T> void               return_temporary_buffer(T* p) noexcept;
168
169template <class T> T* addressof(T& r) noexcept;
170template <class T> T* addressof(const T&& r) noexcept = delete;
171
172template <class InputIterator, class ForwardIterator>
173ForwardIterator
174uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
175
176template <class InputIterator, class Size, class ForwardIterator>
177ForwardIterator
178uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
179
180template <class ForwardIterator, class T>
181void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
182
183template <class ForwardIterator, class Size, class T>
184ForwardIterator
185uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
186
187template <class T>
188void destroy_at(T* location);
189
190template <class ForwardIterator>
191 void destroy(ForwardIterator first, ForwardIterator last);
192
193template <class ForwardIterator, class Size>
194 ForwardIterator destroy_n(ForwardIterator first, Size n);
195
196template <class InputIterator, class ForwardIterator>
197 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
198
199template <class InputIterator, class Size, class ForwardIterator>
200 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
201
202template <class ForwardIterator>
203 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
204
205template <class ForwardIterator, class Size>
206 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
207
208template <class ForwardIterator>
209 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
210
211template <class ForwardIterator, class Size>
212 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
213
214template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
215
216template<class X>
217class auto_ptr                                  // deprecated in C++11, removed in C++17
218{
219public:
220    typedef X element_type;
221
222    explicit auto_ptr(X* p =0) throw();
223    auto_ptr(auto_ptr&) throw();
224    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
225    auto_ptr& operator=(auto_ptr&) throw();
226    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
227    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
228    ~auto_ptr() throw();
229
230    typename add_lvalue_reference<X>::type operator*() const throw();
231    X* operator->() const throw();
232    X* get() const throw();
233    X* release() throw();
234    void reset(X* p =0) throw();
235
236    auto_ptr(auto_ptr_ref<X>) throw();
237    template<class Y> operator auto_ptr_ref<Y>() throw();
238    template<class Y> operator auto_ptr<Y>() throw();
239};
240
241template <class T>
242struct default_delete
243{
244    constexpr default_delete() noexcept = default;
245    template <class U> default_delete(const default_delete<U>&) noexcept;
246
247    void operator()(T*) const noexcept;
248};
249
250template <class T>
251struct default_delete<T[]>
252{
253    constexpr default_delete() noexcept = default;
254    void operator()(T*) const noexcept;
255    template <class U> void operator()(U*) const = delete;
256};
257
258template <class T, class D = default_delete<T>>
259class unique_ptr
260{
261public:
262    typedef see below pointer;
263    typedef T element_type;
264    typedef D deleter_type;
265
266    // constructors
267    constexpr unique_ptr() noexcept;
268    explicit unique_ptr(pointer p) noexcept;
269    unique_ptr(pointer p, see below d1) noexcept;
270    unique_ptr(pointer p, see below d2) noexcept;
271    unique_ptr(unique_ptr&& u) noexcept;
272    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
273    template <class U, class E>
274        unique_ptr(unique_ptr<U, E>&& u) noexcept;
275    template <class U>
276        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
277
278    // destructor
279    ~unique_ptr();
280
281    // assignment
282    unique_ptr& operator=(unique_ptr&& u) noexcept;
283    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
284    unique_ptr& operator=(nullptr_t) noexcept;
285
286    // observers
287    typename add_lvalue_reference<T>::type operator*() const;
288    pointer operator->() const noexcept;
289    pointer get() const noexcept;
290    deleter_type& get_deleter() noexcept;
291    const deleter_type& get_deleter() const noexcept;
292    explicit operator bool() const noexcept;
293
294    // modifiers
295    pointer release() noexcept;
296    void reset(pointer p = pointer()) noexcept;
297    void swap(unique_ptr& u) noexcept;
298};
299
300template <class T, class D>
301class unique_ptr<T[], D>
302{
303public:
304    typedef implementation-defined pointer;
305    typedef T element_type;
306    typedef D deleter_type;
307
308    // constructors
309    constexpr unique_ptr() noexcept;
310    explicit unique_ptr(pointer p) noexcept;
311    unique_ptr(pointer p, see below d) noexcept;
312    unique_ptr(pointer p, see below d) noexcept;
313    unique_ptr(unique_ptr&& u) noexcept;
314    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
315
316    // destructor
317    ~unique_ptr();
318
319    // assignment
320    unique_ptr& operator=(unique_ptr&& u) noexcept;
321    unique_ptr& operator=(nullptr_t) noexcept;
322
323    // observers
324    T& operator[](size_t i) const;
325    pointer get() const noexcept;
326    deleter_type& get_deleter() noexcept;
327    const deleter_type& get_deleter() const noexcept;
328    explicit operator bool() const noexcept;
329
330    // modifiers
331    pointer release() noexcept;
332    void reset(pointer p = pointer()) noexcept;
333    void reset(nullptr_t) noexcept;
334    template <class U> void reset(U) = delete;
335    void swap(unique_ptr& u) noexcept;
336};
337
338template <class T, class D>
339    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
340
341template <class T1, class D1, class T2, class D2>
342    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
343template <class T1, class D1, class T2, class D2>
344    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
345template <class T1, class D1, class T2, class D2>
346    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
347template <class T1, class D1, class T2, class D2>
348    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
349template <class T1, class D1, class T2, class D2>
350    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
351template <class T1, class D1, class T2, class D2>
352    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
353
354template <class T, class D>
355    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
356template <class T, class D>
357    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
358template <class T, class D>
359    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
360template <class T, class D>
361    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
362
363template <class T, class D>
364    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
365template <class T, class D>
366    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
367template <class T, class D>
368    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
369template <class T, class D>
370    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
371template <class T, class D>
372    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
373template <class T, class D>
374    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
375template <class T, class D>
376    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
377template <class T, class D>
378    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
379
380class bad_weak_ptr
381    : public std::exception
382{
383    bad_weak_ptr() noexcept;
384};
385
386template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
387template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
388template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
389
390template<class E, class T, class Y, class D>
391    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
392
393template<class T>
394class shared_ptr
395{
396public:
397    typedef T element_type;
398    typedef weak_ptr<T> weak_type; // C++17
399
400    // constructors:
401    constexpr shared_ptr() noexcept;
402    template<class Y> explicit shared_ptr(Y* p);
403    template<class Y, class D> shared_ptr(Y* p, D d);
404    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
405    template <class D> shared_ptr(nullptr_t p, D d);
406    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
407    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
408    shared_ptr(const shared_ptr& r) noexcept;
409    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
410    shared_ptr(shared_ptr&& r) noexcept;
411    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
412    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
413    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
414    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
415    shared_ptr(nullptr_t) : shared_ptr() { }
416
417    // destructor:
418    ~shared_ptr();
419
420    // assignment:
421    shared_ptr& operator=(const shared_ptr& r) noexcept;
422    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
423    shared_ptr& operator=(shared_ptr&& r) noexcept;
424    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
425    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
426    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
427
428    // modifiers:
429    void swap(shared_ptr& r) noexcept;
430    void reset() noexcept;
431    template<class Y> void reset(Y* p);
432    template<class Y, class D> void reset(Y* p, D d);
433    template<class Y, class D, class A> void reset(Y* p, D d, A a);
434
435    // observers:
436    T* get() const noexcept;
437    T& operator*() const noexcept;
438    T* operator->() const noexcept;
439    long use_count() const noexcept;
440    bool unique() const noexcept;
441    explicit operator bool() const noexcept;
442    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
443    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
444};
445
446// shared_ptr comparisons:
447template<class T, class U>
448    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
449template<class T, class U>
450    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
451template<class T, class U>
452    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
453template<class T, class U>
454    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
455template<class T, class U>
456    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
457template<class T, class U>
458    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
459
460template <class T>
461    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
462template <class T>
463    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
464template <class T>
465    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
466template <class T>
467    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
468template <class T>
469    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
470template <class T>
471bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
472template <class T>
473    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
474template <class T>
475    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
476template <class T>
477    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
478template <class T>
479    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
480template <class T>
481    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
482template <class T>
483    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
484
485// shared_ptr specialized algorithms:
486template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
487
488// shared_ptr casts:
489template<class T, class U>
490    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
491template<class T, class U>
492    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
493template<class T, class U>
494    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
495
496// shared_ptr I/O:
497template<class E, class T, class Y>
498    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
499
500// shared_ptr get_deleter:
501template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
502
503template<class T, class... Args>
504    shared_ptr<T> make_shared(Args&&... args);
505template<class T, class A, class... Args>
506    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
507
508template<class T>
509class weak_ptr
510{
511public:
512    typedef T element_type;
513
514    // constructors
515    constexpr weak_ptr() noexcept;
516    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
517    weak_ptr(weak_ptr const& r) noexcept;
518    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
519    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
520    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
521
522    // destructor
523    ~weak_ptr();
524
525    // assignment
526    weak_ptr& operator=(weak_ptr const& r) noexcept;
527    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
528    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
529    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
530    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
531
532    // modifiers
533    void swap(weak_ptr& r) noexcept;
534    void reset() noexcept;
535
536    // observers
537    long use_count() const noexcept;
538    bool expired() const noexcept;
539    shared_ptr<T> lock() const noexcept;
540    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
541    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
542};
543
544// weak_ptr specialized algorithms:
545template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
546
547// class owner_less:
548template<class T> struct owner_less;
549
550template<class T>
551struct owner_less<shared_ptr<T> >
552    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
553{
554    typedef bool result_type;
555    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
556    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
557    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
558};
559
560template<class T>
561struct owner_less<weak_ptr<T> >
562    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
563{
564    typedef bool result_type;
565    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
566    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
567    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
568};
569
570template <>  // Added in C++14
571struct owner_less<void>
572{
573    template <class _Tp, class _Up>
574    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
575    template <class _Tp, class _Up>
576    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
577    template <class _Tp, class _Up>
578    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
579    template <class _Tp, class _Up>
580    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
581
582    typedef void is_transparent;
583};
584
585template<class T>
586class enable_shared_from_this
587{
588protected:
589    constexpr enable_shared_from_this() noexcept;
590    enable_shared_from_this(enable_shared_from_this const&) noexcept;
591    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
592    ~enable_shared_from_this();
593public:
594    shared_ptr<T> shared_from_this();
595    shared_ptr<T const> shared_from_this() const;
596};
597
598template<class T>
599    bool atomic_is_lock_free(const shared_ptr<T>* p);
600template<class T>
601    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
602template<class T>
603    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
604template<class T>
605    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
606template<class T>
607    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
608template<class T>
609    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
610template<class T>
611    shared_ptr<T>
612    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
613template<class T>
614    bool
615    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
616template<class T>
617    bool
618    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
619template<class T>
620    bool
621    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
622                                          shared_ptr<T> w, memory_order success,
623                                          memory_order failure);
624template<class T>
625    bool
626    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
627                                            shared_ptr<T> w, memory_order success,
628                                            memory_order failure);
629// Hash support
630template <class T> struct hash;
631template <class T, class D> struct hash<unique_ptr<T, D> >;
632template <class T> struct hash<shared_ptr<T> >;
633
634template <class T, class Alloc>
635  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
636
637// Pointer safety
638enum class pointer_safety { relaxed, preferred, strict };
639void declare_reachable(void *p);
640template <class T> T *undeclare_reachable(T *p);
641void declare_no_pointers(char *p, size_t n);
642void undeclare_no_pointers(char *p, size_t n);
643pointer_safety get_pointer_safety() noexcept;
644
645void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
646
647}  // std
648
649*/
650
651#include <__config>
652#include <type_traits>
653#include <typeinfo>
654#include <cstddef>
655#include <cstdint>
656#include <new>
657#include <utility>
658#include <limits>
659#include <iterator>
660#include <__functional_base>
661#include <iosfwd>
662#include <tuple>
663#include <stdexcept>
664#include <cstring>
665#include <cassert>
666#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
667#  include <atomic>
668#endif
669#include <version>
670
671#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
672#pragma GCC system_header
673#endif
674
675_LIBCPP_PUSH_MACROS
676#include <__undef_macros>
677
678
679_LIBCPP_BEGIN_NAMESPACE_STD
680
681template <class _ValueType>
682inline _LIBCPP_INLINE_VISIBILITY
683_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
684#if !defined(_LIBCPP_HAS_NO_THREADS) && \
685    defined(__ATOMIC_RELAXED) &&        \
686    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
687    return __atomic_load_n(__value, __ATOMIC_RELAXED);
688#else
689    return *__value;
690#endif
691}
692
693template <class _ValueType>
694inline _LIBCPP_INLINE_VISIBILITY
695_ValueType __libcpp_acquire_load(_ValueType const* __value) {
696#if !defined(_LIBCPP_HAS_NO_THREADS) && \
697    defined(__ATOMIC_ACQUIRE) &&        \
698    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
699    return __atomic_load_n(__value, __ATOMIC_ACQUIRE);
700#else
701    return *__value;
702#endif
703}
704
705// addressof moved to <type_traits>
706
707template <class _Tp> class allocator;
708
709template <>
710class _LIBCPP_TEMPLATE_VIS allocator<void>
711{
712public:
713    typedef void*             pointer;
714    typedef const void*       const_pointer;
715    typedef void              value_type;
716
717    template <class _Up> struct rebind {typedef allocator<_Up> other;};
718};
719
720template <>
721class _LIBCPP_TEMPLATE_VIS allocator<const void>
722{
723public:
724    typedef const void*       pointer;
725    typedef const void*       const_pointer;
726    typedef const void        value_type;
727
728    template <class _Up> struct rebind {typedef allocator<_Up> other;};
729};
730
731// pointer_traits
732
733template <class _Tp, class = void>
734struct __has_element_type : false_type {};
735
736template <class _Tp>
737struct __has_element_type<_Tp,
738              typename __void_t<typename _Tp::element_type>::type> : true_type {};
739
740template <class _Ptr, bool = __has_element_type<_Ptr>::value>
741struct __pointer_traits_element_type;
742
743template <class _Ptr>
744struct __pointer_traits_element_type<_Ptr, true>
745{
746    typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::element_type type;
747};
748
749#ifndef _LIBCPP_HAS_NO_VARIADICS
750
751template <template <class, class...> class _Sp, class _Tp, class ..._Args>
752struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
753{
754    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::element_type type;
755};
756
757template <template <class, class...> class _Sp, class _Tp, class ..._Args>
758struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
759{
760    typedef _LIBCPP_NODEBUG_TYPE _Tp type;
761};
762
763#else  // _LIBCPP_HAS_NO_VARIADICS
764
765template <template <class> class _Sp, class _Tp>
766struct __pointer_traits_element_type<_Sp<_Tp>, true>
767{
768    typedef typename _Sp<_Tp>::element_type type;
769};
770
771template <template <class> class _Sp, class _Tp>
772struct __pointer_traits_element_type<_Sp<_Tp>, false>
773{
774    typedef _Tp type;
775};
776
777template <template <class, class> class _Sp, class _Tp, class _A0>
778struct __pointer_traits_element_type<_Sp<_Tp, _A0>, true>
779{
780    typedef typename _Sp<_Tp, _A0>::element_type type;
781};
782
783template <template <class, class> class _Sp, class _Tp, class _A0>
784struct __pointer_traits_element_type<_Sp<_Tp, _A0>, false>
785{
786    typedef _Tp type;
787};
788
789template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
790struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, true>
791{
792    typedef typename _Sp<_Tp, _A0, _A1>::element_type type;
793};
794
795template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
796struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, false>
797{
798    typedef _Tp type;
799};
800
801template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
802                                                           class _A1, class _A2>
803struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, true>
804{
805    typedef typename _Sp<_Tp, _A0, _A1, _A2>::element_type type;
806};
807
808template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
809                                                           class _A1, class _A2>
810struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, false>
811{
812    typedef _Tp type;
813};
814
815#endif  // _LIBCPP_HAS_NO_VARIADICS
816
817template <class _Tp, class = void>
818struct __has_difference_type : false_type {};
819
820template <class _Tp>
821struct __has_difference_type<_Tp,
822            typename __void_t<typename _Tp::difference_type>::type> : true_type {};
823
824template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
825struct __pointer_traits_difference_type
826{
827    typedef _LIBCPP_NODEBUG_TYPE ptrdiff_t type;
828};
829
830template <class _Ptr>
831struct __pointer_traits_difference_type<_Ptr, true>
832{
833    typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::difference_type type;
834};
835
836template <class _Tp, class _Up>
837struct __has_rebind
838{
839private:
840    struct __two {char __lx; char __lxx;};
841    template <class _Xp> static __two __test(...);
842    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
843public:
844    static const bool value = sizeof(__test<_Tp>(0)) == 1;
845};
846
847template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
848struct __pointer_traits_rebind
849{
850#ifndef _LIBCPP_CXX03_LANG
851    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up> type;
852#else
853    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up>::other type;
854#endif
855};
856
857#ifndef _LIBCPP_HAS_NO_VARIADICS
858
859template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
860struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
861{
862#ifndef _LIBCPP_CXX03_LANG
863    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
864#else
865    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
866#endif
867};
868
869template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
870struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
871{
872    typedef _Sp<_Up, _Args...> type;
873};
874
875#else  // _LIBCPP_HAS_NO_VARIADICS
876
877template <template <class> class _Sp, class _Tp, class _Up>
878struct __pointer_traits_rebind<_Sp<_Tp>, _Up, true>
879{
880#ifndef _LIBCPP_CXX03_LANG
881    typedef typename _Sp<_Tp>::template rebind<_Up> type;
882#else
883    typedef typename _Sp<_Tp>::template rebind<_Up>::other type;
884#endif
885};
886
887template <template <class> class _Sp, class _Tp, class _Up>
888struct __pointer_traits_rebind<_Sp<_Tp>, _Up, false>
889{
890    typedef _Sp<_Up> type;
891};
892
893template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
894struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, true>
895{
896#ifndef _LIBCPP_CXX03_LANG
897    typedef typename _Sp<_Tp, _A0>::template rebind<_Up> type;
898#else
899    typedef typename _Sp<_Tp, _A0>::template rebind<_Up>::other type;
900#endif
901};
902
903template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
904struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, false>
905{
906    typedef _Sp<_Up, _A0> type;
907};
908
909template <template <class, class, class> class _Sp, class _Tp, class _A0,
910                                         class _A1, class _Up>
911struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, true>
912{
913#ifndef _LIBCPP_CXX03_LANG
914    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up> type;
915#else
916    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up>::other type;
917#endif
918};
919
920template <template <class, class, class> class _Sp, class _Tp, class _A0,
921                                         class _A1, class _Up>
922struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, false>
923{
924    typedef _Sp<_Up, _A0, _A1> type;
925};
926
927template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
928                                                class _A1, class _A2, class _Up>
929struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, true>
930{
931#ifndef _LIBCPP_CXX03_LANG
932    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up> type;
933#else
934    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
935#endif
936};
937
938template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
939                                                class _A1, class _A2, class _Up>
940struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, false>
941{
942    typedef _Sp<_Up, _A0, _A1, _A2> type;
943};
944
945#endif  // _LIBCPP_HAS_NO_VARIADICS
946
947template <class _Ptr>
948struct _LIBCPP_TEMPLATE_VIS pointer_traits
949{
950    typedef _Ptr                                                     pointer;
951    typedef typename __pointer_traits_element_type<pointer>::type    element_type;
952    typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
953
954#ifndef _LIBCPP_CXX03_LANG
955    template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
956#else
957    template <class _Up> struct rebind
958        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
959#endif  // _LIBCPP_CXX03_LANG
960
961private:
962    struct __nat {};
963public:
964    _LIBCPP_INLINE_VISIBILITY
965    static pointer pointer_to(typename conditional<is_void<element_type>::value,
966                                           __nat, element_type>::type& __r)
967        {return pointer::pointer_to(__r);}
968};
969
970template <class _Tp>
971struct _LIBCPP_TEMPLATE_VIS pointer_traits<_Tp*>
972{
973    typedef _Tp*      pointer;
974    typedef _Tp       element_type;
975    typedef ptrdiff_t difference_type;
976
977#ifndef _LIBCPP_CXX03_LANG
978    template <class _Up> using rebind = _Up*;
979#else
980    template <class _Up> struct rebind {typedef _Up* other;};
981#endif
982
983private:
984    struct __nat {};
985public:
986    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
987    static pointer pointer_to(typename conditional<is_void<element_type>::value,
988                                      __nat, element_type>::type& __r) _NOEXCEPT
989        {return _VSTD::addressof(__r);}
990};
991
992template <class _From, class _To>
993struct __rebind_pointer {
994#ifndef _LIBCPP_CXX03_LANG
995    typedef typename pointer_traits<_From>::template rebind<_To>        type;
996#else
997    typedef typename pointer_traits<_From>::template rebind<_To>::other type;
998#endif
999};
1000
1001// allocator_traits
1002
1003template <class _Tp, class = void>
1004struct __has_pointer_type : false_type {};
1005
1006template <class _Tp>
1007struct __has_pointer_type<_Tp,
1008          typename __void_t<typename _Tp::pointer>::type> : true_type {};
1009
1010namespace __pointer_type_imp
1011{
1012
1013template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
1014struct __pointer_type
1015{
1016    typedef _LIBCPP_NODEBUG_TYPE typename _Dp::pointer type;
1017};
1018
1019template <class _Tp, class _Dp>
1020struct __pointer_type<_Tp, _Dp, false>
1021{
1022    typedef _LIBCPP_NODEBUG_TYPE _Tp* type;
1023};
1024
1025}  // __pointer_type_imp
1026
1027template <class _Tp, class _Dp>
1028struct __pointer_type
1029{
1030    typedef _LIBCPP_NODEBUG_TYPE typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
1031};
1032
1033template <class _Tp, class = void>
1034struct __has_const_pointer : false_type {};
1035
1036template <class _Tp>
1037struct __has_const_pointer<_Tp,
1038            typename __void_t<typename _Tp::const_pointer>::type> : true_type {};
1039
1040template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
1041struct __const_pointer
1042{
1043    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::const_pointer type;
1044};
1045
1046template <class _Tp, class _Ptr, class _Alloc>
1047struct __const_pointer<_Tp, _Ptr, _Alloc, false>
1048{
1049#ifndef _LIBCPP_CXX03_LANG
1050    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
1051#else
1052    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
1053#endif
1054};
1055
1056template <class _Tp, class = void>
1057struct __has_void_pointer : false_type {};
1058
1059template <class _Tp>
1060struct __has_void_pointer<_Tp,
1061               typename __void_t<typename _Tp::void_pointer>::type> : true_type {};
1062
1063template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
1064struct __void_pointer
1065{
1066    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::void_pointer type;
1067};
1068
1069template <class _Ptr, class _Alloc>
1070struct __void_pointer<_Ptr, _Alloc, false>
1071{
1072#ifndef _LIBCPP_CXX03_LANG
1073    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<void> type;
1074#else
1075    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<void>::other type;
1076#endif
1077};
1078
1079template <class _Tp, class = void>
1080struct __has_const_void_pointer : false_type {};
1081
1082template <class _Tp>
1083struct __has_const_void_pointer<_Tp,
1084            typename __void_t<typename _Tp::const_void_pointer>::type> : true_type {};
1085
1086template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
1087struct __const_void_pointer
1088{
1089    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::const_void_pointer type;
1090};
1091
1092template <class _Ptr, class _Alloc>
1093struct __const_void_pointer<_Ptr, _Alloc, false>
1094{
1095#ifndef _LIBCPP_CXX03_LANG
1096    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const void> type;
1097#else
1098    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const void>::other type;
1099#endif
1100};
1101
1102template <class _Tp>
1103inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1104_Tp*
1105__to_raw_pointer(_Tp* __p) _NOEXCEPT
1106{
1107    return __p;
1108}
1109
1110#if _LIBCPP_STD_VER <= 17
1111template <class _Pointer>
1112inline _LIBCPP_INLINE_VISIBILITY
1113typename pointer_traits<_Pointer>::element_type*
1114__to_raw_pointer(_Pointer __p) _NOEXCEPT
1115{
1116    return _VSTD::__to_raw_pointer(__p.operator->());
1117}
1118#else
1119template <class _Pointer>
1120inline _LIBCPP_INLINE_VISIBILITY
1121auto
1122__to_raw_pointer(const _Pointer& __p) _NOEXCEPT
1123-> decltype(pointer_traits<_Pointer>::to_address(__p))
1124{
1125    return pointer_traits<_Pointer>::to_address(__p);
1126}
1127
1128template <class _Pointer, class... _None>
1129inline _LIBCPP_INLINE_VISIBILITY
1130auto
1131__to_raw_pointer(const _Pointer& __p, _None...) _NOEXCEPT
1132{
1133    return _VSTD::__to_raw_pointer(__p.operator->());
1134}
1135
1136template <class _Tp>
1137inline _LIBCPP_INLINE_VISIBILITY constexpr
1138_Tp*
1139to_address(_Tp* __p) _NOEXCEPT
1140{
1141    static_assert(!is_function_v<_Tp>, "_Tp is a function type");
1142    return __p;
1143}
1144
1145template <class _Pointer>
1146inline _LIBCPP_INLINE_VISIBILITY
1147auto
1148to_address(const _Pointer& __p) _NOEXCEPT
1149{
1150    return _VSTD::__to_raw_pointer(__p);
1151}
1152#endif
1153
1154template <class _Tp, class = void>
1155struct __has_size_type : false_type {};
1156
1157template <class _Tp>
1158struct __has_size_type<_Tp,
1159               typename __void_t<typename _Tp::size_type>::type> : true_type {};
1160
1161template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
1162struct __size_type
1163{
1164    typedef _LIBCPP_NODEBUG_TYPE typename make_unsigned<_DiffType>::type type;
1165};
1166
1167template <class _Alloc, class _DiffType>
1168struct __size_type<_Alloc, _DiffType, true>
1169{
1170    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::size_type type;
1171};
1172
1173template <class _Tp, class = void>
1174struct __has_propagate_on_container_copy_assignment : false_type {};
1175
1176template <class _Tp>
1177struct __has_propagate_on_container_copy_assignment<_Tp,
1178    typename __void_t<typename _Tp::propagate_on_container_copy_assignment>::type>
1179        : true_type {};
1180
1181template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
1182struct __propagate_on_container_copy_assignment
1183{
1184    typedef _LIBCPP_NODEBUG_TYPE false_type type;
1185};
1186
1187template <class _Alloc>
1188struct __propagate_on_container_copy_assignment<_Alloc, true>
1189{
1190    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_copy_assignment type;
1191};
1192
1193template <class _Tp, class = void>
1194struct __has_propagate_on_container_move_assignment : false_type {};
1195
1196template <class _Tp>
1197struct __has_propagate_on_container_move_assignment<_Tp,
1198           typename __void_t<typename _Tp::propagate_on_container_move_assignment>::type>
1199               : true_type {};
1200
1201template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
1202struct __propagate_on_container_move_assignment
1203{
1204    typedef false_type type;
1205};
1206
1207template <class _Alloc>
1208struct __propagate_on_container_move_assignment<_Alloc, true>
1209{
1210    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_move_assignment type;
1211};
1212
1213template <class _Tp, class = void>
1214struct __has_propagate_on_container_swap : false_type {};
1215
1216template <class _Tp>
1217struct __has_propagate_on_container_swap<_Tp,
1218           typename __void_t<typename _Tp::propagate_on_container_swap>::type>
1219               : true_type {};
1220
1221template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
1222struct __propagate_on_container_swap
1223{
1224    typedef false_type type;
1225};
1226
1227template <class _Alloc>
1228struct __propagate_on_container_swap<_Alloc, true>
1229{
1230    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_swap type;
1231};
1232
1233template <class _Tp, class = void>
1234struct __has_is_always_equal : false_type {};
1235
1236template <class _Tp>
1237struct __has_is_always_equal<_Tp,
1238           typename __void_t<typename _Tp::is_always_equal>::type>
1239               : true_type {};
1240
1241template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
1242struct __is_always_equal
1243{
1244    typedef _LIBCPP_NODEBUG_TYPE typename _VSTD::is_empty<_Alloc>::type type;
1245};
1246
1247template <class _Alloc>
1248struct __is_always_equal<_Alloc, true>
1249{
1250    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::is_always_equal type;
1251};
1252
1253template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
1254struct __has_rebind_other
1255{
1256private:
1257    struct __two {char __lx; char __lxx;};
1258    template <class _Xp> static __two __test(...);
1259    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
1260public:
1261    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1262};
1263
1264template <class _Tp, class _Up>
1265struct __has_rebind_other<_Tp, _Up, false>
1266{
1267    static const bool value = false;
1268};
1269
1270template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
1271struct __allocator_traits_rebind
1272{
1273    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up>::other type;
1274};
1275
1276#ifndef _LIBCPP_HAS_NO_VARIADICS
1277
1278template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1279struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
1280{
1281    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
1282};
1283
1284template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1285struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
1286{
1287    typedef _LIBCPP_NODEBUG_TYPE _Alloc<_Up, _Args...> type;
1288};
1289
1290#else  // _LIBCPP_HAS_NO_VARIADICS
1291
1292template <template <class> class _Alloc, class _Tp, class _Up>
1293struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, true>
1294{
1295    typedef typename _Alloc<_Tp>::template rebind<_Up>::other type;
1296};
1297
1298template <template <class> class _Alloc, class _Tp, class _Up>
1299struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, false>
1300{
1301    typedef _Alloc<_Up> type;
1302};
1303
1304template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1305struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, true>
1306{
1307    typedef typename _Alloc<_Tp, _A0>::template rebind<_Up>::other type;
1308};
1309
1310template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1311struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, false>
1312{
1313    typedef _Alloc<_Up, _A0> type;
1314};
1315
1316template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1317                                         class _A1, class _Up>
1318struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, true>
1319{
1320    typedef typename _Alloc<_Tp, _A0, _A1>::template rebind<_Up>::other type;
1321};
1322
1323template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1324                                         class _A1, class _Up>
1325struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, false>
1326{
1327    typedef _Alloc<_Up, _A0, _A1> type;
1328};
1329
1330template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1331                                                class _A1, class _A2, class _Up>
1332struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, true>
1333{
1334    typedef typename _Alloc<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
1335};
1336
1337template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1338                                                class _A1, class _A2, class _Up>
1339struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, false>
1340{
1341    typedef _Alloc<_Up, _A0, _A1, _A2> type;
1342};
1343
1344#endif  // _LIBCPP_HAS_NO_VARIADICS
1345
1346#ifndef _LIBCPP_CXX03_LANG
1347
1348template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1349auto
1350__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1351    -> decltype((void)__a.allocate(__sz, __p), true_type());
1352
1353template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1354auto
1355__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1356    -> false_type;
1357
1358template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1359struct __has_allocate_hint
1360    : integral_constant<bool,
1361        is_same<
1362            decltype(_VSTD::__has_allocate_hint_test(declval<_Alloc>(),
1363                                          declval<_SizeType>(),
1364                                          declval<_ConstVoidPtr>())),
1365            true_type>::value>
1366{
1367};
1368
1369#else  // _LIBCPP_CXX03_LANG
1370
1371template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1372struct __has_allocate_hint
1373    : true_type
1374{
1375};
1376
1377#endif  // _LIBCPP_CXX03_LANG
1378
1379#if !defined(_LIBCPP_CXX03_LANG)
1380
1381template <class _Alloc, class _Tp, class ..._Args>
1382decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Tp*>(),
1383                                           _VSTD::declval<_Args>()...),
1384                                           true_type())
1385__has_construct_test(_Alloc&& __a, _Tp* __p, _Args&& ...__args);
1386
1387template <class _Alloc, class _Pointer, class ..._Args>
1388false_type
1389__has_construct_test(const _Alloc& __a, _Pointer&& __p, _Args&& ...__args);
1390
1391template <class _Alloc, class _Pointer, class ..._Args>
1392struct __has_construct
1393    : integral_constant<bool,
1394        is_same<
1395            decltype(_VSTD::__has_construct_test(declval<_Alloc>(),
1396                                          declval<_Pointer>(),
1397                                          declval<_Args>()...)),
1398            true_type>::value>
1399{
1400};
1401
1402template <class _Alloc, class _Pointer>
1403auto
1404__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
1405    -> decltype(__a.destroy(__p), true_type());
1406
1407template <class _Alloc, class _Pointer>
1408auto
1409__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
1410    -> false_type;
1411
1412template <class _Alloc, class _Pointer>
1413struct __has_destroy
1414    : integral_constant<bool,
1415        is_same<
1416            decltype(_VSTD::__has_destroy_test(declval<_Alloc>(),
1417                                        declval<_Pointer>())),
1418            true_type>::value>
1419{
1420};
1421
1422template <class _Alloc>
1423auto
1424__has_max_size_test(_Alloc&& __a)
1425    -> decltype(__a.max_size(), true_type());
1426
1427template <class _Alloc>
1428auto
1429__has_max_size_test(const volatile _Alloc& __a)
1430    -> false_type;
1431
1432template <class _Alloc>
1433struct __has_max_size
1434    : integral_constant<bool,
1435        is_same<
1436            decltype(_VSTD::__has_max_size_test(declval<_Alloc&>())),
1437            true_type>::value>
1438{
1439};
1440
1441template <class _Alloc>
1442auto
1443__has_select_on_container_copy_construction_test(_Alloc&& __a)
1444    -> decltype(__a.select_on_container_copy_construction(), true_type());
1445
1446template <class _Alloc>
1447auto
1448__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
1449    -> false_type;
1450
1451template <class _Alloc>
1452struct __has_select_on_container_copy_construction
1453    : integral_constant<bool,
1454        is_same<
1455            decltype(_VSTD::__has_select_on_container_copy_construction_test(declval<_Alloc&>())),
1456            true_type>::value>
1457{
1458};
1459
1460#else  // _LIBCPP_CXX03_LANG
1461
1462template <class _Alloc, class _Pointer, class _Tp, class = void>
1463struct __has_construct : std::false_type {};
1464
1465template <class _Alloc, class _Pointer, class _Tp>
1466struct __has_construct<_Alloc, _Pointer, _Tp, typename __void_t<
1467    decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Pointer>(), _VSTD::declval<_Tp>()))
1468>::type> : std::true_type {};
1469
1470template <class _Alloc, class _Pointer, class = void>
1471struct __has_destroy : false_type {};
1472
1473template <class _Alloc, class _Pointer>
1474struct __has_destroy<_Alloc, _Pointer, typename __void_t<
1475    decltype(_VSTD::declval<_Alloc>().destroy(_VSTD::declval<_Pointer>()))
1476>::type> : std::true_type {};
1477
1478template <class _Alloc>
1479struct __has_max_size
1480    : true_type
1481{
1482};
1483
1484template <class _Alloc>
1485struct __has_select_on_container_copy_construction
1486    : false_type
1487{
1488};
1489
1490#endif  // _LIBCPP_CXX03_LANG
1491
1492template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
1493struct __alloc_traits_difference_type
1494{
1495    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::difference_type type;
1496};
1497
1498template <class _Alloc, class _Ptr>
1499struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
1500{
1501    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::difference_type type;
1502};
1503
1504template <class _Tp>
1505struct __is_default_allocator : false_type {};
1506
1507template <class _Tp>
1508struct __is_default_allocator<_VSTD::allocator<_Tp> > : true_type {};
1509
1510template <class _Alloc>
1511struct _LIBCPP_TEMPLATE_VIS allocator_traits
1512{
1513    typedef _Alloc                              allocator_type;
1514    typedef typename allocator_type::value_type value_type;
1515
1516    typedef typename __pointer_type<value_type, allocator_type>::type pointer;
1517    typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
1518    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
1519    typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;
1520
1521    typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
1522    typedef typename __size_type<allocator_type, difference_type>::type size_type;
1523
1524    typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
1525                     propagate_on_container_copy_assignment;
1526    typedef typename __propagate_on_container_move_assignment<allocator_type>::type
1527                     propagate_on_container_move_assignment;
1528    typedef typename __propagate_on_container_swap<allocator_type>::type
1529                     propagate_on_container_swap;
1530    typedef typename __is_always_equal<allocator_type>::type
1531                     is_always_equal;
1532
1533#ifndef _LIBCPP_CXX03_LANG
1534    template <class _Tp> using rebind_alloc =
1535                  typename __allocator_traits_rebind<allocator_type, _Tp>::type;
1536    template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp> >;
1537#else  // _LIBCPP_CXX03_LANG
1538    template <class _Tp> struct rebind_alloc
1539        {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
1540    template <class _Tp> struct rebind_traits
1541        {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
1542#endif  // _LIBCPP_CXX03_LANG
1543
1544    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1545    static pointer allocate(allocator_type& __a, size_type __n)
1546        {return __a.allocate(__n);}
1547    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1548    static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
1549        {return __allocate(__a, __n, __hint,
1550            __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}
1551
1552    _LIBCPP_INLINE_VISIBILITY
1553    static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
1554        {__a.deallocate(__p, __n);}
1555
1556#ifndef _LIBCPP_HAS_NO_VARIADICS
1557    template <class _Tp, class... _Args>
1558        _LIBCPP_INLINE_VISIBILITY
1559        static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
1560            {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
1561                         __a, __p, _VSTD::forward<_Args>(__args)...);}
1562#else  // _LIBCPP_HAS_NO_VARIADICS
1563    template <class _Tp>
1564        _LIBCPP_INLINE_VISIBILITY
1565        static void construct(allocator_type&, _Tp* __p)
1566            {
1567                ::new ((void*)__p) _Tp();
1568            }
1569    template <class _Tp, class _A0>
1570        _LIBCPP_INLINE_VISIBILITY
1571        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0)
1572            {
1573                __construct(__has_construct<allocator_type, _Tp*, const _A0&>(),
1574                            __a, __p, __a0);
1575            }
1576    template <class _Tp, class _A0, class _A1>
1577        _LIBCPP_INLINE_VISIBILITY
1578        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
1579                              const _A1& __a1)
1580            {
1581                ::new ((void*)__p) _Tp(__a0, __a1);
1582            }
1583    template <class _Tp, class _A0, class _A1, class _A2>
1584        _LIBCPP_INLINE_VISIBILITY
1585        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
1586                              const _A1& __a1, const _A2& __a2)
1587            {
1588                ::new ((void*)__p) _Tp(__a0, __a1, __a2);
1589            }
1590#endif  // _LIBCPP_HAS_NO_VARIADICS
1591
1592    template <class _Tp>
1593        _LIBCPP_INLINE_VISIBILITY
1594        static void destroy(allocator_type& __a, _Tp* __p)
1595            {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}
1596
1597    _LIBCPP_INLINE_VISIBILITY
1598    static size_type max_size(const allocator_type& __a) _NOEXCEPT
1599        {return __max_size(__has_max_size<const allocator_type>(), __a);}
1600
1601    _LIBCPP_INLINE_VISIBILITY
1602    static allocator_type
1603        select_on_container_copy_construction(const allocator_type& __a)
1604            {return __select_on_container_copy_construction(
1605                __has_select_on_container_copy_construction<const allocator_type>(),
1606                __a);}
1607
1608    template <class _Ptr>
1609        _LIBCPP_INLINE_VISIBILITY
1610        static
1611        void
1612        __construct_forward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
1613        {
1614            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1615                construct(__a, _VSTD::__to_raw_pointer(__begin2), _VSTD::move_if_noexcept(*__begin1));
1616        }
1617
1618    template <class _Tp>
1619        _LIBCPP_INLINE_VISIBILITY
1620        static
1621        typename enable_if
1622        <
1623            (__is_default_allocator<allocator_type>::value
1624                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1625             is_trivially_move_constructible<_Tp>::value,
1626            void
1627        >::type
1628        __construct_forward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
1629        {
1630            ptrdiff_t _Np = __end1 - __begin1;
1631            if (_Np > 0)
1632            {
1633                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
1634                __begin2 += _Np;
1635            }
1636        }
1637
1638    template <class _Iter, class _Ptr>
1639        _LIBCPP_INLINE_VISIBILITY
1640        static
1641        void
1642        __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
1643        {
1644            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1645                construct(__a, _VSTD::__to_raw_pointer(__begin2), *__begin1);
1646        }
1647
1648    template <class _SourceTp, class _DestTp,
1649              class _RawSourceTp = typename remove_const<_SourceTp>::type,
1650              class _RawDestTp = typename remove_const<_DestTp>::type>
1651        _LIBCPP_INLINE_VISIBILITY
1652        static
1653        typename enable_if
1654        <
1655            is_trivially_move_constructible<_DestTp>::value &&
1656            is_same<_RawSourceTp, _RawDestTp>::value &&
1657            (__is_default_allocator<allocator_type>::value ||
1658             !__has_construct<allocator_type, _DestTp*, _SourceTp&>::value),
1659            void
1660        >::type
1661        __construct_range_forward(allocator_type&, _SourceTp* __begin1, _SourceTp* __end1, _DestTp*& __begin2)
1662        {
1663            ptrdiff_t _Np = __end1 - __begin1;
1664            if (_Np > 0)
1665            {
1666                _VSTD::memcpy(const_cast<_RawDestTp*>(__begin2), __begin1, _Np * sizeof(_DestTp));
1667                __begin2 += _Np;
1668            }
1669        }
1670
1671    template <class _Ptr>
1672        _LIBCPP_INLINE_VISIBILITY
1673        static
1674        void
1675        __construct_backward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
1676        {
1677            while (__end1 != __begin1)
1678            {
1679                construct(__a, _VSTD::__to_raw_pointer(__end2-1), _VSTD::move_if_noexcept(*--__end1));
1680                --__end2;
1681            }
1682        }
1683
1684    template <class _Tp>
1685        _LIBCPP_INLINE_VISIBILITY
1686        static
1687        typename enable_if
1688        <
1689            (__is_default_allocator<allocator_type>::value
1690                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1691             is_trivially_move_constructible<_Tp>::value,
1692            void
1693        >::type
1694        __construct_backward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
1695        {
1696            ptrdiff_t _Np = __end1 - __begin1;
1697            __end2 -= _Np;
1698            if (_Np > 0)
1699                _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
1700        }
1701
1702private:
1703
1704    _LIBCPP_INLINE_VISIBILITY
1705    static pointer __allocate(allocator_type& __a, size_type __n,
1706        const_void_pointer __hint, true_type)
1707        {return __a.allocate(__n, __hint);}
1708    _LIBCPP_INLINE_VISIBILITY
1709    static pointer __allocate(allocator_type& __a, size_type __n,
1710        const_void_pointer, false_type)
1711        {return __a.allocate(__n);}
1712
1713#ifndef _LIBCPP_HAS_NO_VARIADICS
1714    template <class _Tp, class... _Args>
1715        _LIBCPP_INLINE_VISIBILITY
1716        static void __construct(true_type, allocator_type& __a, _Tp* __p, _Args&&... __args)
1717            {__a.construct(__p, _VSTD::forward<_Args>(__args)...);}
1718    template <class _Tp, class... _Args>
1719        _LIBCPP_INLINE_VISIBILITY
1720        static void __construct(false_type, allocator_type&, _Tp* __p, _Args&&... __args)
1721            {
1722                ::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
1723            }
1724#else  // _LIBCPP_HAS_NO_VARIADICS
1725    template <class _Tp, class _A0>
1726        _LIBCPP_INLINE_VISIBILITY
1727        static void __construct(true_type, allocator_type& __a, _Tp* __p,
1728                                const _A0& __a0)
1729            {__a.construct(__p, __a0);}
1730    template <class _Tp, class _A0>
1731        _LIBCPP_INLINE_VISIBILITY
1732        static void __construct(false_type, allocator_type&, _Tp* __p,
1733                                const _A0& __a0)
1734            {
1735                ::new ((void*)__p) _Tp(__a0);
1736            }
1737#endif  // _LIBCPP_HAS_NO_VARIADICS
1738
1739    template <class _Tp>
1740        _LIBCPP_INLINE_VISIBILITY
1741        static void __destroy(true_type, allocator_type& __a, _Tp* __p)
1742            {__a.destroy(__p);}
1743    template <class _Tp>
1744        _LIBCPP_INLINE_VISIBILITY
1745        static void __destroy(false_type, allocator_type&, _Tp* __p)
1746            {
1747                __p->~_Tp();
1748            }
1749
1750    _LIBCPP_INLINE_VISIBILITY
1751    static size_type __max_size(true_type, const allocator_type& __a) _NOEXCEPT
1752            {return __a.max_size();}
1753    _LIBCPP_INLINE_VISIBILITY
1754    static size_type __max_size(false_type, const allocator_type&) _NOEXCEPT
1755            {return numeric_limits<size_type>::max() / sizeof(value_type);}
1756
1757    _LIBCPP_INLINE_VISIBILITY
1758    static allocator_type
1759        __select_on_container_copy_construction(true_type, const allocator_type& __a)
1760            {return __a.select_on_container_copy_construction();}
1761    _LIBCPP_INLINE_VISIBILITY
1762    static allocator_type
1763        __select_on_container_copy_construction(false_type, const allocator_type& __a)
1764            {return __a;}
1765};
1766
1767template <class _Traits, class _Tp>
1768struct __rebind_alloc_helper
1769{
1770#ifndef _LIBCPP_CXX03_LANG
1771    typedef _LIBCPP_NODEBUG_TYPE typename _Traits::template rebind_alloc<_Tp>        type;
1772#else
1773    typedef typename _Traits::template rebind_alloc<_Tp>::other type;
1774#endif
1775};
1776
1777// allocator
1778
1779template <class _Tp>
1780class _LIBCPP_TEMPLATE_VIS allocator
1781{
1782public:
1783    typedef size_t            size_type;
1784    typedef ptrdiff_t         difference_type;
1785    typedef _Tp*              pointer;
1786    typedef const _Tp*        const_pointer;
1787    typedef _Tp&              reference;
1788    typedef const _Tp&        const_reference;
1789    typedef _Tp               value_type;
1790
1791    typedef true_type propagate_on_container_move_assignment;
1792    typedef true_type is_always_equal;
1793
1794    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1795
1796    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1797    allocator() _NOEXCEPT {}
1798
1799    template <class _Up>
1800    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1801    allocator(const allocator<_Up>&) _NOEXCEPT {}
1802
1803    _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
1804        {return _VSTD::addressof(__x);}
1805    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1806        {return _VSTD::addressof(__x);}
1807    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1808    pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1809        {
1810        if (__n > max_size())
1811            __throw_length_error("allocator<T>::allocate(size_t n)"
1812                                 " 'n' exceeds maximum supported size");
1813        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1814        }
1815    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
1816        {_VSTD::__libcpp_deallocate((void*)__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
1817    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1818        {return size_type(~0) / sizeof(_Tp);}
1819#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1820    template <class _Up, class... _Args>
1821        _LIBCPP_INLINE_VISIBILITY
1822        void
1823        construct(_Up* __p, _Args&&... __args)
1824        {
1825            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1826        }
1827#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1828        _LIBCPP_INLINE_VISIBILITY
1829        void
1830        construct(pointer __p)
1831        {
1832            ::new((void*)__p) _Tp();
1833        }
1834# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1835
1836    template <class _A0>
1837        _LIBCPP_INLINE_VISIBILITY
1838        void
1839        construct(pointer __p, _A0& __a0)
1840        {
1841            ::new((void*)__p) _Tp(__a0);
1842        }
1843    template <class _A0>
1844        _LIBCPP_INLINE_VISIBILITY
1845        void
1846        construct(pointer __p, const _A0& __a0)
1847        {
1848            ::new((void*)__p) _Tp(__a0);
1849        }
1850# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1851    template <class _A0, class _A1>
1852        _LIBCPP_INLINE_VISIBILITY
1853        void
1854        construct(pointer __p, _A0& __a0, _A1& __a1)
1855        {
1856            ::new((void*)__p) _Tp(__a0, __a1);
1857        }
1858    template <class _A0, class _A1>
1859        _LIBCPP_INLINE_VISIBILITY
1860        void
1861        construct(pointer __p, const _A0& __a0, _A1& __a1)
1862        {
1863            ::new((void*)__p) _Tp(__a0, __a1);
1864        }
1865    template <class _A0, class _A1>
1866        _LIBCPP_INLINE_VISIBILITY
1867        void
1868        construct(pointer __p, _A0& __a0, const _A1& __a1)
1869        {
1870            ::new((void*)__p) _Tp(__a0, __a1);
1871        }
1872    template <class _A0, class _A1>
1873        _LIBCPP_INLINE_VISIBILITY
1874        void
1875        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1876        {
1877            ::new((void*)__p) _Tp(__a0, __a1);
1878        }
1879#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1880    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1881};
1882
1883template <class _Tp>
1884class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
1885{
1886public:
1887    typedef size_t            size_type;
1888    typedef ptrdiff_t         difference_type;
1889    typedef const _Tp*        pointer;
1890    typedef const _Tp*        const_pointer;
1891    typedef const _Tp&        reference;
1892    typedef const _Tp&        const_reference;
1893    typedef const _Tp         value_type;
1894
1895    typedef true_type propagate_on_container_move_assignment;
1896    typedef true_type is_always_equal;
1897
1898    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1899
1900    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1901    allocator() _NOEXCEPT {}
1902
1903    template <class _Up>
1904    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1905    allocator(const allocator<_Up>&) _NOEXCEPT {}
1906
1907    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1908        {return _VSTD::addressof(__x);}
1909    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1910    {
1911        if (__n > max_size())
1912            __throw_length_error("allocator<const T>::allocate(size_t n)"
1913                                 " 'n' exceeds maximum supported size");
1914        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1915    }
1916    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type __n) _NOEXCEPT
1917        {_VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));}
1918    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1919        {return size_type(~0) / sizeof(_Tp);}
1920#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1921    template <class _Up, class... _Args>
1922        _LIBCPP_INLINE_VISIBILITY
1923        void
1924        construct(_Up* __p, _Args&&... __args)
1925        {
1926            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1927        }
1928#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1929        _LIBCPP_INLINE_VISIBILITY
1930        void
1931        construct(pointer __p)
1932        {
1933            ::new((void*) const_cast<_Tp *>(__p)) _Tp();
1934        }
1935# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1936
1937    template <class _A0>
1938        _LIBCPP_INLINE_VISIBILITY
1939        void
1940        construct(pointer __p, _A0& __a0)
1941        {
1942            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
1943        }
1944    template <class _A0>
1945        _LIBCPP_INLINE_VISIBILITY
1946        void
1947        construct(pointer __p, const _A0& __a0)
1948        {
1949            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
1950        }
1951# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1952    template <class _A0, class _A1>
1953        _LIBCPP_INLINE_VISIBILITY
1954        void
1955        construct(pointer __p, _A0& __a0, _A1& __a1)
1956        {
1957            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1958        }
1959    template <class _A0, class _A1>
1960        _LIBCPP_INLINE_VISIBILITY
1961        void
1962        construct(pointer __p, const _A0& __a0, _A1& __a1)
1963        {
1964            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1965        }
1966    template <class _A0, class _A1>
1967        _LIBCPP_INLINE_VISIBILITY
1968        void
1969        construct(pointer __p, _A0& __a0, const _A1& __a1)
1970        {
1971            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1972        }
1973    template <class _A0, class _A1>
1974        _LIBCPP_INLINE_VISIBILITY
1975        void
1976        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1977        {
1978            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1979        }
1980#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1981    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1982};
1983
1984template <class _Tp, class _Up>
1985inline _LIBCPP_INLINE_VISIBILITY
1986bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
1987
1988template <class _Tp, class _Up>
1989inline _LIBCPP_INLINE_VISIBILITY
1990bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
1991
1992template <class _OutputIterator, class _Tp>
1993class _LIBCPP_TEMPLATE_VIS raw_storage_iterator
1994    : public iterator<output_iterator_tag,
1995                      _Tp,                                         // purposefully not C++03
1996                      ptrdiff_t,                                   // purposefully not C++03
1997                      _Tp*,                                        // purposefully not C++03
1998                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
1999{
2000private:
2001    _OutputIterator __x_;
2002public:
2003    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
2004    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
2005    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
2006        {::new(_VSTD::addressof(*__x_)) _Tp(__element); return *this;}
2007#if _LIBCPP_STD_VER >= 14
2008    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
2009        {::new(_VSTD::addressof(*__x_)) _Tp(_VSTD::move(__element)); return *this;}
2010#endif
2011    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
2012    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
2013        {raw_storage_iterator __t(*this); ++__x_; return __t;}
2014#if _LIBCPP_STD_VER >= 14
2015    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
2016#endif
2017};
2018
2019template <class _Tp>
2020_LIBCPP_NODISCARD_EXT _LIBCPP_NO_CFI
2021pair<_Tp*, ptrdiff_t>
2022get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
2023{
2024    pair<_Tp*, ptrdiff_t> __r(0, 0);
2025    const ptrdiff_t __m = (~ptrdiff_t(0) ^
2026                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
2027                           / sizeof(_Tp);
2028    if (__n > __m)
2029        __n = __m;
2030    while (__n > 0)
2031    {
2032#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
2033    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
2034        {
2035            std::align_val_t __al =
2036                std::align_val_t(std::alignment_of<_Tp>::value);
2037            __r.first = static_cast<_Tp*>(::operator new(
2038                __n * sizeof(_Tp), __al, nothrow));
2039        } else {
2040            __r.first = static_cast<_Tp*>(::operator new(
2041                __n * sizeof(_Tp), nothrow));
2042        }
2043#else
2044    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
2045        {
2046            // Since aligned operator new is unavailable, return an empty
2047            // buffer rather than one with invalid alignment.
2048            return __r;
2049        }
2050
2051        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
2052#endif
2053
2054        if (__r.first)
2055        {
2056            __r.second = __n;
2057            break;
2058        }
2059        __n /= 2;
2060    }
2061    return __r;
2062}
2063
2064template <class _Tp>
2065inline _LIBCPP_INLINE_VISIBILITY
2066void return_temporary_buffer(_Tp* __p) _NOEXCEPT
2067{
2068  _VSTD::__libcpp_deallocate_unsized((void*)__p, _LIBCPP_ALIGNOF(_Tp));
2069}
2070
2071#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2072template <class _Tp>
2073struct _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr_ref
2074{
2075    _Tp* __ptr_;
2076};
2077
2078template<class _Tp>
2079class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr
2080{
2081private:
2082    _Tp* __ptr_;
2083public:
2084    typedef _Tp element_type;
2085
2086    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) throw() : __ptr_(__p) {}
2087    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) throw() : __ptr_(__p.release()) {}
2088    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) throw()
2089        : __ptr_(__p.release()) {}
2090    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) throw()
2091        {reset(__p.release()); return *this;}
2092    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) throw()
2093        {reset(__p.release()); return *this;}
2094    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) throw()
2095        {reset(__p.__ptr_); return *this;}
2096    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() throw() {delete __ptr_;}
2097
2098    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const throw()
2099        {return *__ptr_;}
2100    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const throw() {return __ptr_;}
2101    _LIBCPP_INLINE_VISIBILITY _Tp* get() const throw() {return __ptr_;}
2102    _LIBCPP_INLINE_VISIBILITY _Tp* release() throw()
2103    {
2104        _Tp* __t = __ptr_;
2105        __ptr_ = 0;
2106        return __t;
2107    }
2108    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) throw()
2109    {
2110        if (__ptr_ != __p)
2111            delete __ptr_;
2112        __ptr_ = __p;
2113    }
2114
2115    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) throw() : __ptr_(__p.__ptr_) {}
2116    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() throw()
2117        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
2118    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() throw()
2119        {return auto_ptr<_Up>(release());}
2120};
2121
2122template <>
2123class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr<void>
2124{
2125public:
2126    typedef void element_type;
2127};
2128#endif
2129
2130template <class _Tp, int _Idx,
2131          bool _CanBeEmptyBase =
2132              is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value>
2133struct __compressed_pair_elem {
2134  typedef _Tp _ParamT;
2135  typedef _Tp& reference;
2136  typedef const _Tp& const_reference;
2137
2138#ifndef _LIBCPP_CXX03_LANG
2139  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() : __value_() {}
2140
2141  template <class _Up, class = typename enable_if<
2142      !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2143  >::type>
2144  _LIBCPP_INLINE_VISIBILITY
2145  constexpr explicit
2146  __compressed_pair_elem(_Up&& __u)
2147      : __value_(_VSTD::forward<_Up>(__u))
2148    {
2149    }
2150
2151  template <class... _Args, size_t... _Indexes>
2152  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2153  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2154                         __tuple_indices<_Indexes...>)
2155      : __value_(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2156#else
2157  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_() {}
2158  _LIBCPP_INLINE_VISIBILITY
2159  __compressed_pair_elem(_ParamT __p) : __value_(std::forward<_ParamT>(__p)) {}
2160#endif
2161
2162  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return __value_; }
2163  _LIBCPP_INLINE_VISIBILITY
2164  const_reference __get() const _NOEXCEPT { return __value_; }
2165
2166private:
2167  _Tp __value_;
2168};
2169
2170template <class _Tp, int _Idx>
2171struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp {
2172  typedef _Tp _ParamT;
2173  typedef _Tp& reference;
2174  typedef const _Tp& const_reference;
2175  typedef _Tp __value_type;
2176
2177#ifndef _LIBCPP_CXX03_LANG
2178  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() = default;
2179
2180  template <class _Up, class = typename enable_if<
2181        !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2182  >::type>
2183  _LIBCPP_INLINE_VISIBILITY
2184  constexpr explicit
2185  __compressed_pair_elem(_Up&& __u)
2186      : __value_type(_VSTD::forward<_Up>(__u))
2187  {}
2188
2189  template <class... _Args, size_t... _Indexes>
2190  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2191  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2192                         __tuple_indices<_Indexes...>)
2193      : __value_type(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2194#else
2195  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_type() {}
2196  _LIBCPP_INLINE_VISIBILITY
2197  __compressed_pair_elem(_ParamT __p)
2198      : __value_type(std::forward<_ParamT>(__p)) {}
2199#endif
2200
2201  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return *this; }
2202  _LIBCPP_INLINE_VISIBILITY
2203  const_reference __get() const _NOEXCEPT { return *this; }
2204};
2205
2206// Tag used to construct the second element of the compressed pair.
2207struct __second_tag {};
2208
2209template <class _T1, class _T2>
2210class __compressed_pair : private __compressed_pair_elem<_T1, 0>,
2211                          private __compressed_pair_elem<_T2, 1> {
2212  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T1, 0> _Base1;
2213  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T2, 1> _Base2;
2214
2215  // NOTE: This static assert should never fire because __compressed_pair
2216  // is *almost never* used in a scenario where it's possible for T1 == T2.
2217  // (The exception is std::function where it is possible that the function
2218  //  object and the allocator have the same type).
2219  static_assert((!is_same<_T1, _T2>::value),
2220    "__compressed_pair cannot be instantated when T1 and T2 are the same type; "
2221    "The current implementation is NOT ABI-compatible with the previous "
2222    "implementation for this configuration");
2223
2224public:
2225#ifndef _LIBCPP_CXX03_LANG
2226  template <bool _Dummy = true,
2227      class = typename enable_if<
2228          __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
2229          __dependent_type<is_default_constructible<_T2>, _Dummy>::value
2230      >::type
2231  >
2232  _LIBCPP_INLINE_VISIBILITY
2233  constexpr __compressed_pair() {}
2234
2235  template <class _Tp, typename enable_if<!is_same<typename decay<_Tp>::type,
2236                                                   __compressed_pair>::value,
2237                                          bool>::type = true>
2238  _LIBCPP_INLINE_VISIBILITY constexpr explicit
2239  __compressed_pair(_Tp&& __t)
2240      : _Base1(std::forward<_Tp>(__t)), _Base2() {}
2241
2242  template <class _Tp>
2243  _LIBCPP_INLINE_VISIBILITY constexpr
2244  __compressed_pair(__second_tag, _Tp&& __t)
2245      : _Base1(), _Base2(std::forward<_Tp>(__t)) {}
2246
2247  template <class _U1, class _U2>
2248  _LIBCPP_INLINE_VISIBILITY constexpr
2249  __compressed_pair(_U1&& __t1, _U2&& __t2)
2250      : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {}
2251
2252  template <class... _Args1, class... _Args2>
2253  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2254  __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
2255                    tuple<_Args2...> __second_args)
2256      : _Base1(__pc, _VSTD::move(__first_args),
2257               typename __make_tuple_indices<sizeof...(_Args1)>::type()),
2258        _Base2(__pc, _VSTD::move(__second_args),
2259               typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}
2260
2261#else
2262  _LIBCPP_INLINE_VISIBILITY
2263  __compressed_pair() {}
2264
2265  _LIBCPP_INLINE_VISIBILITY explicit
2266  __compressed_pair(_T1 __t1) : _Base1(_VSTD::forward<_T1>(__t1)) {}
2267
2268  _LIBCPP_INLINE_VISIBILITY
2269  __compressed_pair(__second_tag, _T2 __t2)
2270      : _Base1(), _Base2(_VSTD::forward<_T2>(__t2)) {}
2271
2272  _LIBCPP_INLINE_VISIBILITY
2273  __compressed_pair(_T1 __t1, _T2 __t2)
2274      : _Base1(_VSTD::forward<_T1>(__t1)), _Base2(_VSTD::forward<_T2>(__t2)) {}
2275#endif
2276
2277  _LIBCPP_INLINE_VISIBILITY
2278  typename _Base1::reference first() _NOEXCEPT {
2279    return static_cast<_Base1&>(*this).__get();
2280  }
2281
2282  _LIBCPP_INLINE_VISIBILITY
2283  typename _Base1::const_reference first() const _NOEXCEPT {
2284    return static_cast<_Base1 const&>(*this).__get();
2285  }
2286
2287  _LIBCPP_INLINE_VISIBILITY
2288  typename _Base2::reference second() _NOEXCEPT {
2289    return static_cast<_Base2&>(*this).__get();
2290  }
2291
2292  _LIBCPP_INLINE_VISIBILITY
2293  typename _Base2::const_reference second() const _NOEXCEPT {
2294    return static_cast<_Base2 const&>(*this).__get();
2295  }
2296
2297  _LIBCPP_INLINE_VISIBILITY
2298  void swap(__compressed_pair& __x)
2299    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2300               __is_nothrow_swappable<_T2>::value)
2301  {
2302    using std::swap;
2303    swap(first(), __x.first());
2304    swap(second(), __x.second());
2305  }
2306};
2307
2308template <class _T1, class _T2>
2309inline _LIBCPP_INLINE_VISIBILITY
2310void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
2311    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2312               __is_nothrow_swappable<_T2>::value) {
2313  __x.swap(__y);
2314}
2315
2316// default_delete
2317
2318template <class _Tp>
2319struct _LIBCPP_TEMPLATE_VIS default_delete {
2320    static_assert(!is_function<_Tp>::value,
2321                  "default_delete cannot be instantiated for function types");
2322#ifndef _LIBCPP_CXX03_LANG
2323  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2324#else
2325  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2326#endif
2327  template <class _Up>
2328  _LIBCPP_INLINE_VISIBILITY
2329  default_delete(const default_delete<_Up>&,
2330                 typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* =
2331                     0) _NOEXCEPT {}
2332
2333  _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __ptr) const _NOEXCEPT {
2334    static_assert(sizeof(_Tp) > 0,
2335                  "default_delete can not delete incomplete type");
2336    static_assert(!is_void<_Tp>::value,
2337                  "default_delete can not delete incomplete type");
2338    delete __ptr;
2339  }
2340};
2341
2342template <class _Tp>
2343struct _LIBCPP_TEMPLATE_VIS default_delete<_Tp[]> {
2344private:
2345  template <class _Up>
2346  struct _EnableIfConvertible
2347      : enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value> {};
2348
2349public:
2350#ifndef _LIBCPP_CXX03_LANG
2351  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2352#else
2353  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2354#endif
2355
2356  template <class _Up>
2357  _LIBCPP_INLINE_VISIBILITY
2358  default_delete(const default_delete<_Up[]>&,
2359                 typename _EnableIfConvertible<_Up>::type* = 0) _NOEXCEPT {}
2360
2361  template <class _Up>
2362  _LIBCPP_INLINE_VISIBILITY
2363  typename _EnableIfConvertible<_Up>::type
2364  operator()(_Up* __ptr) const _NOEXCEPT {
2365    static_assert(sizeof(_Tp) > 0,
2366                  "default_delete can not delete incomplete type");
2367    static_assert(!is_void<_Tp>::value,
2368                  "default_delete can not delete void type");
2369    delete[] __ptr;
2370  }
2371};
2372
2373template <class _Deleter>
2374struct __unique_ptr_deleter_sfinae {
2375  static_assert(!is_reference<_Deleter>::value, "incorrect specialization");
2376  typedef const _Deleter& __lval_ref_type;
2377  typedef _Deleter&& __good_rval_ref_type;
2378  typedef true_type __enable_rval_overload;
2379};
2380
2381template <class _Deleter>
2382struct __unique_ptr_deleter_sfinae<_Deleter const&> {
2383  typedef const _Deleter& __lval_ref_type;
2384  typedef const _Deleter&& __bad_rval_ref_type;
2385  typedef false_type __enable_rval_overload;
2386};
2387
2388template <class _Deleter>
2389struct __unique_ptr_deleter_sfinae<_Deleter&> {
2390  typedef _Deleter& __lval_ref_type;
2391  typedef _Deleter&& __bad_rval_ref_type;
2392  typedef false_type __enable_rval_overload;
2393};
2394
2395template <class _Tp, class _Dp = default_delete<_Tp> >
2396class _LIBCPP_TEMPLATE_VIS unique_ptr {
2397public:
2398  typedef _Tp element_type;
2399  typedef _Dp deleter_type;
2400  typedef _LIBCPP_NODEBUG_TYPE typename __pointer_type<_Tp, deleter_type>::type pointer;
2401
2402  static_assert(!is_rvalue_reference<deleter_type>::value,
2403                "the specified deleter type cannot be an rvalue reference");
2404
2405private:
2406  __compressed_pair<pointer, deleter_type> __ptr_;
2407
2408  struct __nat { int __for_bool_; };
2409
2410  typedef _LIBCPP_NODEBUG_TYPE __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2411
2412  template <bool _Dummy>
2413  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2414      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2415
2416  template <bool _Dummy>
2417  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2418      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2419
2420  template <bool _Dummy>
2421  using _BadRValRefType _LIBCPP_NODEBUG_TYPE  =
2422      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2423
2424  template <bool _Dummy, class _Deleter = typename __dependent_type<
2425                             __identity<deleter_type>, _Dummy>::type>
2426  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE =
2427      typename enable_if<is_default_constructible<_Deleter>::value &&
2428                         !is_pointer<_Deleter>::value>::type;
2429
2430  template <class _ArgType>
2431  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2432      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2433
2434  template <class _UPtr, class _Up>
2435  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2436      is_convertible<typename _UPtr::pointer, pointer>::value &&
2437      !is_array<_Up>::value
2438  >::type;
2439
2440  template <class _UDel>
2441  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2442      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2443      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2444    >::type;
2445
2446  template <class _UDel>
2447  using _EnableIfDeleterAssignable = typename enable_if<
2448      is_assignable<_Dp&, _UDel&&>::value
2449    >::type;
2450
2451public:
2452  template <bool _Dummy = true,
2453            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2454  _LIBCPP_INLINE_VISIBILITY
2455  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer()) {}
2456
2457  template <bool _Dummy = true,
2458            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2459  _LIBCPP_INLINE_VISIBILITY
2460  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer()) {}
2461
2462  template <bool _Dummy = true,
2463            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2464  _LIBCPP_INLINE_VISIBILITY
2465  explicit unique_ptr(pointer __p) _NOEXCEPT : __ptr_(__p) {}
2466
2467  template <bool _Dummy = true,
2468            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2469  _LIBCPP_INLINE_VISIBILITY
2470  unique_ptr(pointer __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2471      : __ptr_(__p, __d) {}
2472
2473  template <bool _Dummy = true,
2474            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2475  _LIBCPP_INLINE_VISIBILITY
2476  unique_ptr(pointer __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2477      : __ptr_(__p, _VSTD::move(__d)) {
2478    static_assert(!is_reference<deleter_type>::value,
2479                  "rvalue deleter bound to reference");
2480  }
2481
2482  template <bool _Dummy = true,
2483            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> > >
2484  _LIBCPP_INLINE_VISIBILITY
2485  unique_ptr(pointer __p, _BadRValRefType<_Dummy> __d) = delete;
2486
2487  _LIBCPP_INLINE_VISIBILITY
2488  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2489      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2490  }
2491
2492  template <class _Up, class _Ep,
2493      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2494      class = _EnableIfDeleterConvertible<_Ep>
2495  >
2496  _LIBCPP_INLINE_VISIBILITY
2497  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2498      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
2499
2500#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2501  template <class _Up>
2502  _LIBCPP_INLINE_VISIBILITY
2503  unique_ptr(auto_ptr<_Up>&& __p,
2504             typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2505                                    is_same<_Dp, default_delete<_Tp> >::value,
2506                                __nat>::type = __nat()) _NOEXCEPT
2507      : __ptr_(__p.release()) {}
2508#endif
2509
2510  _LIBCPP_INLINE_VISIBILITY
2511  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2512    reset(__u.release());
2513    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2514    return *this;
2515  }
2516
2517  template <class _Up, class _Ep,
2518      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2519      class = _EnableIfDeleterAssignable<_Ep>
2520  >
2521  _LIBCPP_INLINE_VISIBILITY
2522  unique_ptr& operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2523    reset(__u.release());
2524    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2525    return *this;
2526  }
2527
2528#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2529  template <class _Up>
2530  _LIBCPP_INLINE_VISIBILITY
2531      typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2532                             is_same<_Dp, default_delete<_Tp> >::value,
2533                         unique_ptr&>::type
2534      operator=(auto_ptr<_Up> __p) {
2535    reset(__p.release());
2536    return *this;
2537  }
2538#endif
2539
2540#ifdef _LIBCPP_CXX03_LANG
2541  unique_ptr(unique_ptr const&) = delete;
2542  unique_ptr& operator=(unique_ptr const&) = delete;
2543#endif
2544
2545
2546  _LIBCPP_INLINE_VISIBILITY
2547  ~unique_ptr() { reset(); }
2548
2549  _LIBCPP_INLINE_VISIBILITY
2550  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2551    reset();
2552    return *this;
2553  }
2554
2555  _LIBCPP_INLINE_VISIBILITY
2556  typename add_lvalue_reference<_Tp>::type
2557  operator*() const {
2558    return *__ptr_.first();
2559  }
2560  _LIBCPP_INLINE_VISIBILITY
2561  pointer operator->() const _NOEXCEPT {
2562    return __ptr_.first();
2563  }
2564  _LIBCPP_INLINE_VISIBILITY
2565  pointer get() const _NOEXCEPT {
2566    return __ptr_.first();
2567  }
2568  _LIBCPP_INLINE_VISIBILITY
2569  deleter_type& get_deleter() _NOEXCEPT {
2570    return __ptr_.second();
2571  }
2572  _LIBCPP_INLINE_VISIBILITY
2573  const deleter_type& get_deleter() const _NOEXCEPT {
2574    return __ptr_.second();
2575  }
2576  _LIBCPP_INLINE_VISIBILITY
2577  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2578    return __ptr_.first() != nullptr;
2579  }
2580
2581  _LIBCPP_INLINE_VISIBILITY
2582  pointer release() _NOEXCEPT {
2583    pointer __t = __ptr_.first();
2584    __ptr_.first() = pointer();
2585    return __t;
2586  }
2587
2588  _LIBCPP_INLINE_VISIBILITY
2589  void reset(pointer __p = pointer()) _NOEXCEPT {
2590    pointer __tmp = __ptr_.first();
2591    __ptr_.first() = __p;
2592    if (__tmp)
2593      __ptr_.second()(__tmp);
2594  }
2595
2596  _LIBCPP_INLINE_VISIBILITY
2597  void swap(unique_ptr& __u) _NOEXCEPT {
2598    __ptr_.swap(__u.__ptr_);
2599  }
2600};
2601
2602
2603template <class _Tp, class _Dp>
2604class _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
2605public:
2606  typedef _Tp element_type;
2607  typedef _Dp deleter_type;
2608  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2609
2610private:
2611  __compressed_pair<pointer, deleter_type> __ptr_;
2612
2613  template <class _From>
2614  struct _CheckArrayPointerConversion : is_same<_From, pointer> {};
2615
2616  template <class _FromElem>
2617  struct _CheckArrayPointerConversion<_FromElem*>
2618      : integral_constant<bool,
2619          is_same<_FromElem*, pointer>::value ||
2620            (is_same<pointer, element_type*>::value &&
2621             is_convertible<_FromElem(*)[], element_type(*)[]>::value)
2622      >
2623  {};
2624
2625  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2626
2627  template <bool _Dummy>
2628  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2629      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2630
2631  template <bool _Dummy>
2632  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2633      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2634
2635  template <bool _Dummy>
2636  using _BadRValRefType _LIBCPP_NODEBUG_TYPE =
2637      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2638
2639  template <bool _Dummy, class _Deleter = typename __dependent_type<
2640                             __identity<deleter_type>, _Dummy>::type>
2641  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE  =
2642      typename enable_if<is_default_constructible<_Deleter>::value &&
2643                         !is_pointer<_Deleter>::value>::type;
2644
2645  template <class _ArgType>
2646  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2647      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2648
2649  template <class _Pp>
2650  using _EnableIfPointerConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2651      _CheckArrayPointerConversion<_Pp>::value
2652  >::type;
2653
2654  template <class _UPtr, class _Up,
2655        class _ElemT = typename _UPtr::element_type>
2656  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2657      is_array<_Up>::value &&
2658      is_same<pointer, element_type*>::value &&
2659      is_same<typename _UPtr::pointer, _ElemT*>::value &&
2660      is_convertible<_ElemT(*)[], element_type(*)[]>::value
2661    >::type;
2662
2663  template <class _UDel>
2664  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2665      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2666      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2667    >::type;
2668
2669  template <class _UDel>
2670  using _EnableIfDeleterAssignable _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2671      is_assignable<_Dp&, _UDel&&>::value
2672    >::type;
2673
2674public:
2675  template <bool _Dummy = true,
2676            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2677  _LIBCPP_INLINE_VISIBILITY
2678  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer()) {}
2679
2680  template <bool _Dummy = true,
2681            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2682  _LIBCPP_INLINE_VISIBILITY
2683  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer()) {}
2684
2685  template <class _Pp, bool _Dummy = true,
2686            class = _EnableIfDeleterDefaultConstructible<_Dummy>,
2687            class = _EnableIfPointerConvertible<_Pp> >
2688  _LIBCPP_INLINE_VISIBILITY
2689  explicit unique_ptr(_Pp __p) _NOEXCEPT
2690      : __ptr_(__p) {}
2691
2692  template <class _Pp, bool _Dummy = true,
2693            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> >,
2694            class = _EnableIfPointerConvertible<_Pp> >
2695  _LIBCPP_INLINE_VISIBILITY
2696  unique_ptr(_Pp __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2697      : __ptr_(__p, __d) {}
2698
2699  template <bool _Dummy = true,
2700            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2701  _LIBCPP_INLINE_VISIBILITY
2702  unique_ptr(nullptr_t, _LValRefType<_Dummy> __d) _NOEXCEPT
2703      : __ptr_(nullptr, __d) {}
2704
2705  template <class _Pp, bool _Dummy = true,
2706            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> >,
2707            class = _EnableIfPointerConvertible<_Pp> >
2708  _LIBCPP_INLINE_VISIBILITY
2709  unique_ptr(_Pp __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2710      : __ptr_(__p, _VSTD::move(__d)) {
2711    static_assert(!is_reference<deleter_type>::value,
2712                  "rvalue deleter bound to reference");
2713  }
2714
2715  template <bool _Dummy = true,
2716            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2717  _LIBCPP_INLINE_VISIBILITY
2718  unique_ptr(nullptr_t, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2719      : __ptr_(nullptr, _VSTD::move(__d)) {
2720    static_assert(!is_reference<deleter_type>::value,
2721                  "rvalue deleter bound to reference");
2722  }
2723
2724  template <class _Pp, bool _Dummy = true,
2725            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> >,
2726            class = _EnableIfPointerConvertible<_Pp> >
2727  _LIBCPP_INLINE_VISIBILITY
2728  unique_ptr(_Pp __p, _BadRValRefType<_Dummy> __d) = delete;
2729
2730  _LIBCPP_INLINE_VISIBILITY
2731  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2732      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2733  }
2734
2735  _LIBCPP_INLINE_VISIBILITY
2736  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2737    reset(__u.release());
2738    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2739    return *this;
2740  }
2741
2742  template <class _Up, class _Ep,
2743      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2744      class = _EnableIfDeleterConvertible<_Ep>
2745  >
2746  _LIBCPP_INLINE_VISIBILITY
2747  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2748      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {
2749  }
2750
2751  template <class _Up, class _Ep,
2752      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2753      class = _EnableIfDeleterAssignable<_Ep>
2754  >
2755  _LIBCPP_INLINE_VISIBILITY
2756  unique_ptr&
2757  operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2758    reset(__u.release());
2759    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2760    return *this;
2761  }
2762
2763#ifdef _LIBCPP_CXX03_LANG
2764  unique_ptr(unique_ptr const&) = delete;
2765  unique_ptr& operator=(unique_ptr const&) = delete;
2766#endif
2767
2768public:
2769  _LIBCPP_INLINE_VISIBILITY
2770  ~unique_ptr() { reset(); }
2771
2772  _LIBCPP_INLINE_VISIBILITY
2773  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2774    reset();
2775    return *this;
2776  }
2777
2778  _LIBCPP_INLINE_VISIBILITY
2779  typename add_lvalue_reference<_Tp>::type
2780  operator[](size_t __i) const {
2781    return __ptr_.first()[__i];
2782  }
2783  _LIBCPP_INLINE_VISIBILITY
2784  pointer get() const _NOEXCEPT {
2785    return __ptr_.first();
2786  }
2787
2788  _LIBCPP_INLINE_VISIBILITY
2789  deleter_type& get_deleter() _NOEXCEPT {
2790    return __ptr_.second();
2791  }
2792
2793  _LIBCPP_INLINE_VISIBILITY
2794  const deleter_type& get_deleter() const _NOEXCEPT {
2795    return __ptr_.second();
2796  }
2797  _LIBCPP_INLINE_VISIBILITY
2798  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2799    return __ptr_.first() != nullptr;
2800  }
2801
2802  _LIBCPP_INLINE_VISIBILITY
2803  pointer release() _NOEXCEPT {
2804    pointer __t = __ptr_.first();
2805    __ptr_.first() = pointer();
2806    return __t;
2807  }
2808
2809  template <class _Pp>
2810  _LIBCPP_INLINE_VISIBILITY
2811  typename enable_if<
2812      _CheckArrayPointerConversion<_Pp>::value
2813  >::type
2814  reset(_Pp __p) _NOEXCEPT {
2815    pointer __tmp = __ptr_.first();
2816    __ptr_.first() = __p;
2817    if (__tmp)
2818      __ptr_.second()(__tmp);
2819  }
2820
2821  _LIBCPP_INLINE_VISIBILITY
2822  void reset(nullptr_t = nullptr) _NOEXCEPT {
2823    pointer __tmp = __ptr_.first();
2824    __ptr_.first() = nullptr;
2825    if (__tmp)
2826      __ptr_.second()(__tmp);
2827  }
2828
2829  _LIBCPP_INLINE_VISIBILITY
2830  void swap(unique_ptr& __u) _NOEXCEPT {
2831    __ptr_.swap(__u.__ptr_);
2832  }
2833
2834};
2835
2836template <class _Tp, class _Dp>
2837inline _LIBCPP_INLINE_VISIBILITY
2838typename enable_if<
2839    __is_swappable<_Dp>::value,
2840    void
2841>::type
2842swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
2843
2844template <class _T1, class _D1, class _T2, class _D2>
2845inline _LIBCPP_INLINE_VISIBILITY
2846bool
2847operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
2848
2849template <class _T1, class _D1, class _T2, class _D2>
2850inline _LIBCPP_INLINE_VISIBILITY
2851bool
2852operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
2853
2854template <class _T1, class _D1, class _T2, class _D2>
2855inline _LIBCPP_INLINE_VISIBILITY
2856bool
2857operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
2858{
2859    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2860    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
2861    typedef typename common_type<_P1, _P2>::type _Vp;
2862    return less<_Vp>()(__x.get(), __y.get());
2863}
2864
2865template <class _T1, class _D1, class _T2, class _D2>
2866inline _LIBCPP_INLINE_VISIBILITY
2867bool
2868operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
2869
2870template <class _T1, class _D1, class _T2, class _D2>
2871inline _LIBCPP_INLINE_VISIBILITY
2872bool
2873operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
2874
2875template <class _T1, class _D1, class _T2, class _D2>
2876inline _LIBCPP_INLINE_VISIBILITY
2877bool
2878operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
2879
2880template <class _T1, class _D1>
2881inline _LIBCPP_INLINE_VISIBILITY
2882bool
2883operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2884{
2885    return !__x;
2886}
2887
2888template <class _T1, class _D1>
2889inline _LIBCPP_INLINE_VISIBILITY
2890bool
2891operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2892{
2893    return !__x;
2894}
2895
2896template <class _T1, class _D1>
2897inline _LIBCPP_INLINE_VISIBILITY
2898bool
2899operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2900{
2901    return static_cast<bool>(__x);
2902}
2903
2904template <class _T1, class _D1>
2905inline _LIBCPP_INLINE_VISIBILITY
2906bool
2907operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2908{
2909    return static_cast<bool>(__x);
2910}
2911
2912template <class _T1, class _D1>
2913inline _LIBCPP_INLINE_VISIBILITY
2914bool
2915operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2916{
2917    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2918    return less<_P1>()(__x.get(), nullptr);
2919}
2920
2921template <class _T1, class _D1>
2922inline _LIBCPP_INLINE_VISIBILITY
2923bool
2924operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2925{
2926    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2927    return less<_P1>()(nullptr, __x.get());
2928}
2929
2930template <class _T1, class _D1>
2931inline _LIBCPP_INLINE_VISIBILITY
2932bool
2933operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2934{
2935    return nullptr < __x;
2936}
2937
2938template <class _T1, class _D1>
2939inline _LIBCPP_INLINE_VISIBILITY
2940bool
2941operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2942{
2943    return __x < nullptr;
2944}
2945
2946template <class _T1, class _D1>
2947inline _LIBCPP_INLINE_VISIBILITY
2948bool
2949operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2950{
2951    return !(nullptr < __x);
2952}
2953
2954template <class _T1, class _D1>
2955inline _LIBCPP_INLINE_VISIBILITY
2956bool
2957operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2958{
2959    return !(__x < nullptr);
2960}
2961
2962template <class _T1, class _D1>
2963inline _LIBCPP_INLINE_VISIBILITY
2964bool
2965operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2966{
2967    return !(__x < nullptr);
2968}
2969
2970template <class _T1, class _D1>
2971inline _LIBCPP_INLINE_VISIBILITY
2972bool
2973operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2974{
2975    return !(nullptr < __x);
2976}
2977
2978#if _LIBCPP_STD_VER > 11
2979
2980template<class _Tp>
2981struct __unique_if
2982{
2983    typedef unique_ptr<_Tp> __unique_single;
2984};
2985
2986template<class _Tp>
2987struct __unique_if<_Tp[]>
2988{
2989    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
2990};
2991
2992template<class _Tp, size_t _Np>
2993struct __unique_if<_Tp[_Np]>
2994{
2995    typedef void __unique_array_known_bound;
2996};
2997
2998template<class _Tp, class... _Args>
2999inline _LIBCPP_INLINE_VISIBILITY
3000typename __unique_if<_Tp>::__unique_single
3001make_unique(_Args&&... __args)
3002{
3003    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
3004}
3005
3006template<class _Tp>
3007inline _LIBCPP_INLINE_VISIBILITY
3008typename __unique_if<_Tp>::__unique_array_unknown_bound
3009make_unique(size_t __n)
3010{
3011    typedef typename remove_extent<_Tp>::type _Up;
3012    return unique_ptr<_Tp>(new _Up[__n]());
3013}
3014
3015template<class _Tp, class... _Args>
3016    typename __unique_if<_Tp>::__unique_array_known_bound
3017    make_unique(_Args&&...) = delete;
3018
3019#endif  // _LIBCPP_STD_VER > 11
3020
3021template <class _Tp, class _Dp>
3022#ifdef _LIBCPP_CXX03_LANG
3023struct _LIBCPP_TEMPLATE_VIS hash<unique_ptr<_Tp, _Dp> >
3024#else
3025struct _LIBCPP_TEMPLATE_VIS hash<__enable_hash_helper<
3026    unique_ptr<_Tp, _Dp>, typename unique_ptr<_Tp, _Dp>::pointer> >
3027#endif
3028{
3029    typedef unique_ptr<_Tp, _Dp> argument_type;
3030    typedef size_t               result_type;
3031    _LIBCPP_INLINE_VISIBILITY
3032    result_type operator()(const argument_type& __ptr) const
3033    {
3034        typedef typename argument_type::pointer pointer;
3035        return hash<pointer>()(__ptr.get());
3036    }
3037};
3038
3039struct __destruct_n
3040{
3041private:
3042    size_t __size_;
3043
3044    template <class _Tp>
3045    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
3046        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
3047
3048    template <class _Tp>
3049    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
3050        {}
3051
3052    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
3053        {++__size_;}
3054    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
3055        {}
3056
3057    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
3058        {__size_ = __s;}
3059    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
3060        {}
3061public:
3062    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
3063        : __size_(__s) {}
3064
3065    template <class _Tp>
3066    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
3067        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3068
3069    template <class _Tp>
3070    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
3071        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3072
3073    template <class _Tp>
3074    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
3075        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3076};
3077
3078template <class _Alloc>
3079class __allocator_destructor
3080{
3081    typedef _LIBCPP_NODEBUG_TYPE allocator_traits<_Alloc> __alloc_traits;
3082public:
3083    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::pointer pointer;
3084    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::size_type size_type;
3085private:
3086    _Alloc& __alloc_;
3087    size_type __s_;
3088public:
3089    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
3090             _NOEXCEPT
3091        : __alloc_(__a), __s_(__s) {}
3092    _LIBCPP_INLINE_VISIBILITY
3093    void operator()(pointer __p) _NOEXCEPT
3094        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
3095};
3096
3097template <class _InputIterator, class _ForwardIterator>
3098_ForwardIterator
3099uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
3100{
3101    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3102#ifndef _LIBCPP_NO_EXCEPTIONS
3103    _ForwardIterator __s = __r;
3104    try
3105    {
3106#endif
3107        for (; __f != __l; ++__f, (void) ++__r)
3108            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3109#ifndef _LIBCPP_NO_EXCEPTIONS
3110    }
3111    catch (...)
3112    {
3113        for (; __s != __r; ++__s)
3114            __s->~value_type();
3115        throw;
3116    }
3117#endif
3118    return __r;
3119}
3120
3121template <class _InputIterator, class _Size, class _ForwardIterator>
3122_ForwardIterator
3123uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
3124{
3125    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3126#ifndef _LIBCPP_NO_EXCEPTIONS
3127    _ForwardIterator __s = __r;
3128    try
3129    {
3130#endif
3131        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
3132            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3133#ifndef _LIBCPP_NO_EXCEPTIONS
3134    }
3135    catch (...)
3136    {
3137        for (; __s != __r; ++__s)
3138            __s->~value_type();
3139        throw;
3140    }
3141#endif
3142    return __r;
3143}
3144
3145template <class _ForwardIterator, class _Tp>
3146void
3147uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
3148{
3149    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3150#ifndef _LIBCPP_NO_EXCEPTIONS
3151    _ForwardIterator __s = __f;
3152    try
3153    {
3154#endif
3155        for (; __f != __l; ++__f)
3156            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3157#ifndef _LIBCPP_NO_EXCEPTIONS
3158    }
3159    catch (...)
3160    {
3161        for (; __s != __f; ++__s)
3162            __s->~value_type();
3163        throw;
3164    }
3165#endif
3166}
3167
3168template <class _ForwardIterator, class _Size, class _Tp>
3169_ForwardIterator
3170uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
3171{
3172    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3173#ifndef _LIBCPP_NO_EXCEPTIONS
3174    _ForwardIterator __s = __f;
3175    try
3176    {
3177#endif
3178        for (; __n > 0; ++__f, (void) --__n)
3179            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3180#ifndef _LIBCPP_NO_EXCEPTIONS
3181    }
3182    catch (...)
3183    {
3184        for (; __s != __f; ++__s)
3185            __s->~value_type();
3186        throw;
3187    }
3188#endif
3189    return __f;
3190}
3191
3192#if _LIBCPP_STD_VER > 14
3193
3194template <class _Tp>
3195inline _LIBCPP_INLINE_VISIBILITY
3196void destroy_at(_Tp* __loc) {
3197    _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
3198    __loc->~_Tp();
3199}
3200
3201template <class _ForwardIterator>
3202inline _LIBCPP_INLINE_VISIBILITY
3203void destroy(_ForwardIterator __first, _ForwardIterator __last) {
3204    for (; __first != __last; ++__first)
3205        _VSTD::destroy_at(_VSTD::addressof(*__first));
3206}
3207
3208template <class _ForwardIterator, class _Size>
3209inline _LIBCPP_INLINE_VISIBILITY
3210_ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
3211    for (; __n > 0; (void)++__first, --__n)
3212        _VSTD::destroy_at(_VSTD::addressof(*__first));
3213    return __first;
3214}
3215
3216template <class _ForwardIterator>
3217inline _LIBCPP_INLINE_VISIBILITY
3218void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
3219    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3220    auto __idx = __first;
3221#ifndef _LIBCPP_NO_EXCEPTIONS
3222    try {
3223#endif
3224    for (; __idx != __last; ++__idx)
3225        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3226#ifndef _LIBCPP_NO_EXCEPTIONS
3227    } catch (...) {
3228        _VSTD::destroy(__first, __idx);
3229        throw;
3230    }
3231#endif
3232}
3233
3234template <class _ForwardIterator, class _Size>
3235inline _LIBCPP_INLINE_VISIBILITY
3236_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
3237    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3238    auto __idx = __first;
3239#ifndef _LIBCPP_NO_EXCEPTIONS
3240    try {
3241#endif
3242    for (; __n > 0; (void)++__idx, --__n)
3243        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3244    return __idx;
3245#ifndef _LIBCPP_NO_EXCEPTIONS
3246    } catch (...) {
3247        _VSTD::destroy(__first, __idx);
3248        throw;
3249    }
3250#endif
3251}
3252
3253
3254template <class _ForwardIterator>
3255inline _LIBCPP_INLINE_VISIBILITY
3256void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
3257    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3258    auto __idx = __first;
3259#ifndef _LIBCPP_NO_EXCEPTIONS
3260    try {
3261#endif
3262    for (; __idx != __last; ++__idx)
3263        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3264#ifndef _LIBCPP_NO_EXCEPTIONS
3265    } catch (...) {
3266        _VSTD::destroy(__first, __idx);
3267        throw;
3268    }
3269#endif
3270}
3271
3272template <class _ForwardIterator, class _Size>
3273inline _LIBCPP_INLINE_VISIBILITY
3274_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
3275    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3276    auto __idx = __first;
3277#ifndef _LIBCPP_NO_EXCEPTIONS
3278    try {
3279#endif
3280    for (; __n > 0; (void)++__idx, --__n)
3281        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3282    return __idx;
3283#ifndef _LIBCPP_NO_EXCEPTIONS
3284    } catch (...) {
3285        _VSTD::destroy(__first, __idx);
3286        throw;
3287    }
3288#endif
3289}
3290
3291
3292template <class _InputIt, class _ForwardIt>
3293inline _LIBCPP_INLINE_VISIBILITY
3294_ForwardIt uninitialized_move(_InputIt __first, _InputIt __last, _ForwardIt __first_res) {
3295    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3296    auto __idx = __first_res;
3297#ifndef _LIBCPP_NO_EXCEPTIONS
3298    try {
3299#endif
3300    for (; __first != __last; (void)++__idx, ++__first)
3301        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3302    return __idx;
3303#ifndef _LIBCPP_NO_EXCEPTIONS
3304    } catch (...) {
3305        _VSTD::destroy(__first_res, __idx);
3306        throw;
3307    }
3308#endif
3309}
3310
3311template <class _InputIt, class _Size, class _ForwardIt>
3312inline _LIBCPP_INLINE_VISIBILITY
3313pair<_InputIt, _ForwardIt>
3314uninitialized_move_n(_InputIt __first, _Size __n, _ForwardIt __first_res) {
3315    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3316    auto __idx = __first_res;
3317#ifndef _LIBCPP_NO_EXCEPTIONS
3318    try {
3319#endif
3320    for (; __n > 0; ++__idx, (void)++__first, --__n)
3321        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3322    return {__first, __idx};
3323#ifndef _LIBCPP_NO_EXCEPTIONS
3324    } catch (...) {
3325        _VSTD::destroy(__first_res, __idx);
3326        throw;
3327    }
3328#endif
3329}
3330
3331
3332#endif // _LIBCPP_STD_VER > 14
3333
3334// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
3335// should be sufficient for thread safety.
3336// See https://bugs.llvm.org/show_bug.cgi?id=22803
3337#if defined(__clang__) && __has_builtin(__atomic_add_fetch)          \
3338                       && defined(__ATOMIC_RELAXED)                  \
3339                       && defined(__ATOMIC_ACQ_REL)
3340#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3341#elif defined(_LIBCPP_COMPILER_GCC)
3342#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3343#endif
3344
3345template <class _Tp>
3346inline _LIBCPP_INLINE_VISIBILITY _Tp
3347__libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT
3348{
3349#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3350    return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
3351#else
3352    return __t += 1;
3353#endif
3354}
3355
3356template <class _Tp>
3357inline _LIBCPP_INLINE_VISIBILITY _Tp
3358__libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT
3359{
3360#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3361    return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
3362#else
3363    return __t -= 1;
3364#endif
3365}
3366
3367class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
3368    : public std::exception
3369{
3370public:
3371    virtual ~bad_weak_ptr() _NOEXCEPT;
3372    virtual const char* what() const  _NOEXCEPT;
3373};
3374
3375_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
3376void __throw_bad_weak_ptr()
3377{
3378#ifndef _LIBCPP_NO_EXCEPTIONS
3379    throw bad_weak_ptr();
3380#else
3381    _VSTD::abort();
3382#endif
3383}
3384
3385template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr;
3386
3387class _LIBCPP_TYPE_VIS __shared_count
3388{
3389    __shared_count(const __shared_count&);
3390    __shared_count& operator=(const __shared_count&);
3391
3392protected:
3393    long __shared_owners_;
3394    virtual ~__shared_count();
3395private:
3396    virtual void __on_zero_shared() _NOEXCEPT = 0;
3397
3398public:
3399    _LIBCPP_INLINE_VISIBILITY
3400    explicit __shared_count(long __refs = 0) _NOEXCEPT
3401        : __shared_owners_(__refs) {}
3402
3403#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3404    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3405    void __add_shared() _NOEXCEPT;
3406    bool __release_shared() _NOEXCEPT;
3407#else
3408    _LIBCPP_INLINE_VISIBILITY
3409    void __add_shared() _NOEXCEPT {
3410      __libcpp_atomic_refcount_increment(__shared_owners_);
3411    }
3412    _LIBCPP_INLINE_VISIBILITY
3413    bool __release_shared() _NOEXCEPT {
3414      if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
3415        __on_zero_shared();
3416        return true;
3417      }
3418      return false;
3419    }
3420#endif
3421    _LIBCPP_INLINE_VISIBILITY
3422    long use_count() const _NOEXCEPT {
3423        return __libcpp_relaxed_load(&__shared_owners_) + 1;
3424    }
3425};
3426
3427class _LIBCPP_TYPE_VIS __shared_weak_count
3428    : private __shared_count
3429{
3430    long __shared_weak_owners_;
3431
3432public:
3433    _LIBCPP_INLINE_VISIBILITY
3434    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
3435        : __shared_count(__refs),
3436          __shared_weak_owners_(__refs) {}
3437protected:
3438    virtual ~__shared_weak_count();
3439
3440public:
3441#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3442    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3443    void __add_shared() _NOEXCEPT;
3444    void __add_weak() _NOEXCEPT;
3445    void __release_shared() _NOEXCEPT;
3446#else
3447    _LIBCPP_INLINE_VISIBILITY
3448    void __add_shared() _NOEXCEPT {
3449      __shared_count::__add_shared();
3450    }
3451    _LIBCPP_INLINE_VISIBILITY
3452    void __add_weak() _NOEXCEPT {
3453      __libcpp_atomic_refcount_increment(__shared_weak_owners_);
3454    }
3455    _LIBCPP_INLINE_VISIBILITY
3456    void __release_shared() _NOEXCEPT {
3457      if (__shared_count::__release_shared())
3458        __release_weak();
3459    }
3460#endif
3461    void __release_weak() _NOEXCEPT;
3462    _LIBCPP_INLINE_VISIBILITY
3463    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
3464    __shared_weak_count* lock() _NOEXCEPT;
3465
3466    // Define the function out only if we build static libc++ without RTTI.
3467    // Otherwise we may break clients who need to compile their projects with
3468    // -fno-rtti and yet link against a libc++.dylib compiled
3469    // without -fno-rtti.
3470#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
3471    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3472#endif
3473private:
3474    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
3475};
3476
3477template <class _Tp, class _Dp, class _Alloc>
3478class __shared_ptr_pointer
3479    : public __shared_weak_count
3480{
3481    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
3482public:
3483    _LIBCPP_INLINE_VISIBILITY
3484    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
3485        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
3486
3487#ifndef _LIBCPP_NO_RTTI
3488    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3489#endif
3490
3491private:
3492    virtual void __on_zero_shared() _NOEXCEPT;
3493    virtual void __on_zero_shared_weak() _NOEXCEPT;
3494};
3495
3496#ifndef _LIBCPP_NO_RTTI
3497
3498template <class _Tp, class _Dp, class _Alloc>
3499const void*
3500__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
3501{
3502    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr;
3503}
3504
3505#endif  // _LIBCPP_NO_RTTI
3506
3507template <class _Tp, class _Dp, class _Alloc>
3508void
3509__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
3510{
3511    __data_.first().second()(__data_.first().first());
3512    __data_.first().second().~_Dp();
3513}
3514
3515template <class _Tp, class _Dp, class _Alloc>
3516void
3517__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3518{
3519    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
3520    typedef allocator_traits<_Al> _ATraits;
3521    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3522
3523    _Al __a(__data_.second());
3524    __data_.second().~_Alloc();
3525    __a.deallocate(_PTraits::pointer_to(*this), 1);
3526}
3527
3528template <class _Tp, class _Alloc>
3529class __shared_ptr_emplace
3530    : public __shared_weak_count
3531{
3532    __compressed_pair<_Alloc, _Tp> __data_;
3533public:
3534#ifndef _LIBCPP_HAS_NO_VARIADICS
3535
3536    _LIBCPP_INLINE_VISIBILITY
3537    __shared_ptr_emplace(_Alloc __a)
3538        :  __data_(_VSTD::move(__a)) {}
3539
3540    template <class ..._Args>
3541        _LIBCPP_INLINE_VISIBILITY
3542        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
3543            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
3544                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
3545
3546#else  // _LIBCPP_HAS_NO_VARIADICS
3547
3548    _LIBCPP_INLINE_VISIBILITY
3549    __shared_ptr_emplace(_Alloc __a)
3550        :  __data_(__a) {}
3551
3552    template <class _A0>
3553        _LIBCPP_INLINE_VISIBILITY
3554        __shared_ptr_emplace(_Alloc __a, _A0& __a0)
3555            :  __data_(__a, _Tp(__a0)) {}
3556
3557    template <class _A0, class _A1>
3558        _LIBCPP_INLINE_VISIBILITY
3559        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
3560            :  __data_(__a, _Tp(__a0, __a1)) {}
3561
3562    template <class _A0, class _A1, class _A2>
3563        _LIBCPP_INLINE_VISIBILITY
3564        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
3565            :  __data_(__a, _Tp(__a0, __a1, __a2)) {}
3566
3567#endif  // _LIBCPP_HAS_NO_VARIADICS
3568
3569private:
3570    virtual void __on_zero_shared() _NOEXCEPT;
3571    virtual void __on_zero_shared_weak() _NOEXCEPT;
3572public:
3573    _LIBCPP_INLINE_VISIBILITY
3574    _Tp* get() _NOEXCEPT {return _VSTD::addressof(__data_.second());}
3575};
3576
3577template <class _Tp, class _Alloc>
3578void
3579__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
3580{
3581    __data_.second().~_Tp();
3582}
3583
3584template <class _Tp, class _Alloc>
3585void
3586__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3587{
3588    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
3589    typedef allocator_traits<_Al> _ATraits;
3590    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3591    _Al __a(__data_.first());
3592    __data_.first().~_Alloc();
3593    __a.deallocate(_PTraits::pointer_to(*this), 1);
3594}
3595
3596struct __shared_ptr_dummy_rebind_allocator_type;
3597template <>
3598class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type>
3599{
3600public:
3601    template <class _Other>
3602    struct rebind
3603    {
3604        typedef allocator<_Other> other;
3605    };
3606};
3607
3608template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
3609
3610template<class _Tp>
3611class _LIBCPP_TEMPLATE_VIS shared_ptr
3612{
3613public:
3614    typedef _Tp element_type;
3615
3616#if _LIBCPP_STD_VER > 14
3617    typedef weak_ptr<_Tp> weak_type;
3618#endif
3619private:
3620    element_type*      __ptr_;
3621    __shared_weak_count* __cntrl_;
3622
3623    struct __nat {int __for_bool_;};
3624public:
3625    _LIBCPP_INLINE_VISIBILITY
3626    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
3627    _LIBCPP_INLINE_VISIBILITY
3628    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
3629    template<class _Yp>
3630        explicit shared_ptr(_Yp* __p,
3631                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3632    template<class _Yp, class _Dp>
3633        shared_ptr(_Yp* __p, _Dp __d,
3634                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3635    template<class _Yp, class _Dp, class _Alloc>
3636        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3637                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3638    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
3639    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
3640    template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
3641    _LIBCPP_INLINE_VISIBILITY
3642    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
3643    template<class _Yp>
3644        _LIBCPP_INLINE_VISIBILITY
3645        shared_ptr(const shared_ptr<_Yp>& __r,
3646                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
3647                       _NOEXCEPT;
3648#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3649    _LIBCPP_INLINE_VISIBILITY
3650    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
3651    template<class _Yp> _LIBCPP_INLINE_VISIBILITY  shared_ptr(shared_ptr<_Yp>&& __r,
3652                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
3653                       _NOEXCEPT;
3654#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3655    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
3656                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type= __nat());
3657#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3658#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3659    template<class _Yp>
3660        shared_ptr(auto_ptr<_Yp>&& __r,
3661                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3662#else
3663    template<class _Yp>
3664        shared_ptr(auto_ptr<_Yp> __r,
3665                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3666#endif
3667#endif
3668#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3669    template <class _Yp, class _Dp>
3670        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3671                   typename enable_if
3672                   <
3673                       !is_lvalue_reference<_Dp>::value &&
3674                       !is_array<_Yp>::value &&
3675                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3676                       __nat
3677                   >::type = __nat());
3678    template <class _Yp, class _Dp>
3679        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3680                   typename enable_if
3681                   <
3682                       is_lvalue_reference<_Dp>::value &&
3683                       !is_array<_Yp>::value &&
3684                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3685                       __nat
3686                   >::type = __nat());
3687#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3688    template <class _Yp, class _Dp>
3689        shared_ptr(unique_ptr<_Yp, _Dp>,
3690                   typename enable_if
3691                   <
3692                       !is_lvalue_reference<_Dp>::value &&
3693                       !is_array<_Yp>::value &&
3694                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3695                       __nat
3696                   >::type = __nat());
3697    template <class _Yp, class _Dp>
3698        shared_ptr(unique_ptr<_Yp, _Dp>,
3699                   typename enable_if
3700                   <
3701                       is_lvalue_reference<_Dp>::value &&
3702                       !is_array<_Yp>::value &&
3703                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3704                       __nat
3705                   >::type = __nat());
3706#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3707
3708    ~shared_ptr();
3709
3710    _LIBCPP_INLINE_VISIBILITY
3711    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
3712    template<class _Yp>
3713        typename enable_if
3714        <
3715            is_convertible<_Yp*, element_type*>::value,
3716            shared_ptr&
3717        >::type
3718        _LIBCPP_INLINE_VISIBILITY
3719        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
3720#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3721    _LIBCPP_INLINE_VISIBILITY
3722    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
3723    template<class _Yp>
3724        typename enable_if
3725        <
3726            is_convertible<_Yp*, element_type*>::value,
3727            shared_ptr<_Tp>&
3728        >::type
3729        _LIBCPP_INLINE_VISIBILITY
3730        operator=(shared_ptr<_Yp>&& __r);
3731#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3732    template<class _Yp>
3733        _LIBCPP_INLINE_VISIBILITY
3734        typename enable_if
3735        <
3736            !is_array<_Yp>::value &&
3737            is_convertible<_Yp*, element_type*>::value,
3738            shared_ptr
3739        >::type&
3740        operator=(auto_ptr<_Yp>&& __r);
3741#endif
3742#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3743#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3744    template<class _Yp>
3745        _LIBCPP_INLINE_VISIBILITY
3746        typename enable_if
3747        <
3748            !is_array<_Yp>::value &&
3749            is_convertible<_Yp*, element_type*>::value,
3750            shared_ptr&
3751        >::type
3752        operator=(auto_ptr<_Yp> __r);
3753#endif
3754#endif
3755    template <class _Yp, class _Dp>
3756        typename enable_if
3757        <
3758            !is_array<_Yp>::value &&
3759            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3760            shared_ptr&
3761        >::type
3762#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3763        _LIBCPP_INLINE_VISIBILITY
3764        operator=(unique_ptr<_Yp, _Dp>&& __r);
3765#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3766        _LIBCPP_INLINE_VISIBILITY
3767        operator=(unique_ptr<_Yp, _Dp> __r);
3768#endif
3769
3770    _LIBCPP_INLINE_VISIBILITY
3771    void swap(shared_ptr& __r) _NOEXCEPT;
3772    _LIBCPP_INLINE_VISIBILITY
3773    void reset() _NOEXCEPT;
3774    template<class _Yp>
3775        typename enable_if
3776        <
3777            is_convertible<_Yp*, element_type*>::value,
3778            void
3779        >::type
3780        _LIBCPP_INLINE_VISIBILITY
3781        reset(_Yp* __p);
3782    template<class _Yp, class _Dp>
3783        typename enable_if
3784        <
3785            is_convertible<_Yp*, element_type*>::value,
3786            void
3787        >::type
3788        _LIBCPP_INLINE_VISIBILITY
3789        reset(_Yp* __p, _Dp __d);
3790    template<class _Yp, class _Dp, class _Alloc>
3791        typename enable_if
3792        <
3793            is_convertible<_Yp*, element_type*>::value,
3794            void
3795        >::type
3796        _LIBCPP_INLINE_VISIBILITY
3797        reset(_Yp* __p, _Dp __d, _Alloc __a);
3798
3799    _LIBCPP_INLINE_VISIBILITY
3800    element_type* get() const _NOEXCEPT {return __ptr_;}
3801    _LIBCPP_INLINE_VISIBILITY
3802    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
3803        {return *__ptr_;}
3804    _LIBCPP_INLINE_VISIBILITY
3805    element_type* operator->() const _NOEXCEPT {return __ptr_;}
3806    _LIBCPP_INLINE_VISIBILITY
3807    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
3808    _LIBCPP_INLINE_VISIBILITY
3809    bool unique() const _NOEXCEPT {return use_count() == 1;}
3810    _LIBCPP_INLINE_VISIBILITY
3811    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
3812    template <class _Up>
3813        _LIBCPP_INLINE_VISIBILITY
3814        bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT
3815        {return __cntrl_ < __p.__cntrl_;}
3816    template <class _Up>
3817        _LIBCPP_INLINE_VISIBILITY
3818        bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT
3819        {return __cntrl_ < __p.__cntrl_;}
3820    _LIBCPP_INLINE_VISIBILITY
3821    bool
3822    __owner_equivalent(const shared_ptr& __p) const
3823        {return __cntrl_ == __p.__cntrl_;}
3824
3825#ifndef _LIBCPP_NO_RTTI
3826    template <class _Dp>
3827        _LIBCPP_INLINE_VISIBILITY
3828        _Dp* __get_deleter() const _NOEXCEPT
3829            {return static_cast<_Dp*>(__cntrl_
3830                    ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp)))
3831                      : nullptr);}
3832#endif  // _LIBCPP_NO_RTTI
3833
3834#ifndef _LIBCPP_HAS_NO_VARIADICS
3835
3836    template<class ..._Args>
3837        static
3838        shared_ptr<_Tp>
3839        make_shared(_Args&& ...__args);
3840
3841    template<class _Alloc, class ..._Args>
3842        static
3843        shared_ptr<_Tp>
3844        allocate_shared(const _Alloc& __a, _Args&& ...__args);
3845
3846#else  // _LIBCPP_HAS_NO_VARIADICS
3847
3848    static shared_ptr<_Tp> make_shared();
3849
3850    template<class _A0>
3851        static shared_ptr<_Tp> make_shared(_A0&);
3852
3853    template<class _A0, class _A1>
3854        static shared_ptr<_Tp> make_shared(_A0&, _A1&);
3855
3856    template<class _A0, class _A1, class _A2>
3857        static shared_ptr<_Tp> make_shared(_A0&, _A1&, _A2&);
3858
3859    template<class _Alloc>
3860        static shared_ptr<_Tp>
3861        allocate_shared(const _Alloc& __a);
3862
3863    template<class _Alloc, class _A0>
3864        static shared_ptr<_Tp>
3865        allocate_shared(const _Alloc& __a, _A0& __a0);
3866
3867    template<class _Alloc, class _A0, class _A1>
3868        static shared_ptr<_Tp>
3869        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1);
3870
3871    template<class _Alloc, class _A0, class _A1, class _A2>
3872        static shared_ptr<_Tp>
3873        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2);
3874
3875#endif  // _LIBCPP_HAS_NO_VARIADICS
3876
3877private:
3878    template <class _Yp, bool = is_function<_Yp>::value>
3879        struct __shared_ptr_default_allocator
3880        {
3881            typedef allocator<_Yp> type;
3882        };
3883
3884    template <class _Yp>
3885        struct __shared_ptr_default_allocator<_Yp, true>
3886        {
3887            typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
3888        };
3889
3890    template <class _Yp, class _OrigPtr>
3891        _LIBCPP_INLINE_VISIBILITY
3892        typename enable_if<is_convertible<_OrigPtr*,
3893                                          const enable_shared_from_this<_Yp>*
3894        >::value,
3895            void>::type
3896        __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
3897                           _OrigPtr* __ptr) _NOEXCEPT
3898        {
3899            typedef typename remove_cv<_Yp>::type _RawYp;
3900            if (__e && __e->__weak_this_.expired())
3901            {
3902                __e->__weak_this_ = shared_ptr<_RawYp>(*this,
3903                    const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
3904            }
3905        }
3906
3907    _LIBCPP_INLINE_VISIBILITY void __enable_weak_this(...) _NOEXCEPT {}
3908
3909    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
3910    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
3911};
3912
3913
3914template<class _Tp>
3915inline
3916_LIBCPP_CONSTEXPR
3917shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
3918    : __ptr_(0),
3919      __cntrl_(0)
3920{
3921}
3922
3923template<class _Tp>
3924inline
3925_LIBCPP_CONSTEXPR
3926shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
3927    : __ptr_(0),
3928      __cntrl_(0)
3929{
3930}
3931
3932template<class _Tp>
3933template<class _Yp>
3934shared_ptr<_Tp>::shared_ptr(_Yp* __p,
3935                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
3936    : __ptr_(__p)
3937{
3938    unique_ptr<_Yp> __hold(__p);
3939    typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3940    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, _AllocT > _CntrlBlk;
3941    __cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), _AllocT());
3942    __hold.release();
3943    __enable_weak_this(__p, __p);
3944}
3945
3946template<class _Tp>
3947template<class _Yp, class _Dp>
3948shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
3949                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
3950    : __ptr_(__p)
3951{
3952#ifndef _LIBCPP_NO_EXCEPTIONS
3953    try
3954    {
3955#endif  // _LIBCPP_NO_EXCEPTIONS
3956        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3957        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
3958        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
3959        __enable_weak_this(__p, __p);
3960#ifndef _LIBCPP_NO_EXCEPTIONS
3961    }
3962    catch (...)
3963    {
3964        __d(__p);
3965        throw;
3966    }
3967#endif  // _LIBCPP_NO_EXCEPTIONS
3968}
3969
3970template<class _Tp>
3971template<class _Dp>
3972shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
3973    : __ptr_(0)
3974{
3975#ifndef _LIBCPP_NO_EXCEPTIONS
3976    try
3977    {
3978#endif  // _LIBCPP_NO_EXCEPTIONS
3979        typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
3980        typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
3981        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
3982#ifndef _LIBCPP_NO_EXCEPTIONS
3983    }
3984    catch (...)
3985    {
3986        __d(__p);
3987        throw;
3988    }
3989#endif  // _LIBCPP_NO_EXCEPTIONS
3990}
3991
3992template<class _Tp>
3993template<class _Yp, class _Dp, class _Alloc>
3994shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3995                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
3996    : __ptr_(__p)
3997{
3998#ifndef _LIBCPP_NO_EXCEPTIONS
3999    try
4000    {
4001#endif  // _LIBCPP_NO_EXCEPTIONS
4002        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
4003        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4004        typedef __allocator_destructor<_A2> _D2;
4005        _A2 __a2(__a);
4006        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4007        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4008            _CntrlBlk(__p, __d, __a);
4009        __cntrl_ = _VSTD::addressof(*__hold2.release());
4010        __enable_weak_this(__p, __p);
4011#ifndef _LIBCPP_NO_EXCEPTIONS
4012    }
4013    catch (...)
4014    {
4015        __d(__p);
4016        throw;
4017    }
4018#endif  // _LIBCPP_NO_EXCEPTIONS
4019}
4020
4021template<class _Tp>
4022template<class _Dp, class _Alloc>
4023shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
4024    : __ptr_(0)
4025{
4026#ifndef _LIBCPP_NO_EXCEPTIONS
4027    try
4028    {
4029#endif  // _LIBCPP_NO_EXCEPTIONS
4030        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
4031        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4032        typedef __allocator_destructor<_A2> _D2;
4033        _A2 __a2(__a);
4034        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4035        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4036            _CntrlBlk(__p, __d, __a);
4037        __cntrl_ = _VSTD::addressof(*__hold2.release());
4038#ifndef _LIBCPP_NO_EXCEPTIONS
4039    }
4040    catch (...)
4041    {
4042        __d(__p);
4043        throw;
4044    }
4045#endif  // _LIBCPP_NO_EXCEPTIONS
4046}
4047
4048template<class _Tp>
4049template<class _Yp>
4050inline
4051shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
4052    : __ptr_(__p),
4053      __cntrl_(__r.__cntrl_)
4054{
4055    if (__cntrl_)
4056        __cntrl_->__add_shared();
4057}
4058
4059template<class _Tp>
4060inline
4061shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
4062    : __ptr_(__r.__ptr_),
4063      __cntrl_(__r.__cntrl_)
4064{
4065    if (__cntrl_)
4066        __cntrl_->__add_shared();
4067}
4068
4069template<class _Tp>
4070template<class _Yp>
4071inline
4072shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
4073                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4074         _NOEXCEPT
4075    : __ptr_(__r.__ptr_),
4076      __cntrl_(__r.__cntrl_)
4077{
4078    if (__cntrl_)
4079        __cntrl_->__add_shared();
4080}
4081
4082#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4083
4084template<class _Tp>
4085inline
4086shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
4087    : __ptr_(__r.__ptr_),
4088      __cntrl_(__r.__cntrl_)
4089{
4090    __r.__ptr_ = 0;
4091    __r.__cntrl_ = 0;
4092}
4093
4094template<class _Tp>
4095template<class _Yp>
4096inline
4097shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
4098                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4099         _NOEXCEPT
4100    : __ptr_(__r.__ptr_),
4101      __cntrl_(__r.__cntrl_)
4102{
4103    __r.__ptr_ = 0;
4104    __r.__cntrl_ = 0;
4105}
4106
4107#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4108
4109#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4110template<class _Tp>
4111template<class _Yp>
4112#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4113shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
4114#else
4115shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp> __r,
4116#endif
4117                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4118    : __ptr_(__r.get())
4119{
4120    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
4121    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
4122    __enable_weak_this(__r.get(), __r.get());
4123    __r.release();
4124}
4125#endif
4126
4127template<class _Tp>
4128template <class _Yp, class _Dp>
4129#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4130shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4131#else
4132shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4133#endif
4134                            typename enable_if
4135                            <
4136                                !is_lvalue_reference<_Dp>::value &&
4137                                !is_array<_Yp>::value &&
4138                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4139                                __nat
4140                            >::type)
4141    : __ptr_(__r.get())
4142{
4143#if _LIBCPP_STD_VER > 11
4144    if (__ptr_ == nullptr)
4145        __cntrl_ = nullptr;
4146    else
4147#endif
4148    {
4149        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4150        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
4151        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), _AllocT());
4152        __enable_weak_this(__r.get(), __r.get());
4153    }
4154    __r.release();
4155}
4156
4157template<class _Tp>
4158template <class _Yp, class _Dp>
4159#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4160shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4161#else
4162shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4163#endif
4164                            typename enable_if
4165                            <
4166                                is_lvalue_reference<_Dp>::value &&
4167                                !is_array<_Yp>::value &&
4168                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4169                                __nat
4170                            >::type)
4171    : __ptr_(__r.get())
4172{
4173#if _LIBCPP_STD_VER > 11
4174    if (__ptr_ == nullptr)
4175        __cntrl_ = nullptr;
4176    else
4177#endif
4178    {
4179        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4180        typedef __shared_ptr_pointer<_Yp*,
4181                                     reference_wrapper<typename remove_reference<_Dp>::type>,
4182                                     _AllocT > _CntrlBlk;
4183        __cntrl_ = new _CntrlBlk(__r.get(), ref(__r.get_deleter()), _AllocT());
4184        __enable_weak_this(__r.get(), __r.get());
4185    }
4186    __r.release();
4187}
4188
4189#ifndef _LIBCPP_HAS_NO_VARIADICS
4190
4191template<class _Tp>
4192template<class ..._Args>
4193shared_ptr<_Tp>
4194shared_ptr<_Tp>::make_shared(_Args&& ...__args)
4195{
4196    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in make_shared" );
4197    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4198    typedef allocator<_CntrlBlk> _A2;
4199    typedef __allocator_destructor<_A2> _D2;
4200    _A2 __a2;
4201    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4202    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
4203    shared_ptr<_Tp> __r;
4204    __r.__ptr_ = __hold2.get()->get();
4205    __r.__cntrl_ = __hold2.release();
4206    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4207    return __r;
4208}
4209
4210template<class _Tp>
4211template<class _Alloc, class ..._Args>
4212shared_ptr<_Tp>
4213shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _Args&& ...__args)
4214{
4215    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in allocate_shared" );
4216    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4217    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4218    typedef __allocator_destructor<_A2> _D2;
4219    _A2 __a2(__a);
4220    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4221    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4222        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
4223    shared_ptr<_Tp> __r;
4224    __r.__ptr_ = __hold2.get()->get();
4225    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4226    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4227    return __r;
4228}
4229
4230#else  // _LIBCPP_HAS_NO_VARIADICS
4231
4232template<class _Tp>
4233shared_ptr<_Tp>
4234shared_ptr<_Tp>::make_shared()
4235{
4236    static_assert((is_constructible<_Tp>::value), "Can't construct object in make_shared" );
4237    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4238    typedef allocator<_CntrlBlk> _Alloc2;
4239    typedef __allocator_destructor<_Alloc2> _D2;
4240    _Alloc2 __alloc2;
4241    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4242    ::new(__hold2.get()) _CntrlBlk(__alloc2);
4243    shared_ptr<_Tp> __r;
4244    __r.__ptr_ = __hold2.get()->get();
4245    __r.__cntrl_ = __hold2.release();
4246    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4247    return __r;
4248}
4249
4250template<class _Tp>
4251template<class _A0>
4252shared_ptr<_Tp>
4253shared_ptr<_Tp>::make_shared(_A0& __a0)
4254{
4255    static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in make_shared" );
4256    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4257    typedef allocator<_CntrlBlk> _Alloc2;
4258    typedef __allocator_destructor<_Alloc2> _D2;
4259    _Alloc2 __alloc2;
4260    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4261    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0);
4262    shared_ptr<_Tp> __r;
4263    __r.__ptr_ = __hold2.get()->get();
4264    __r.__cntrl_ = __hold2.release();
4265    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4266    return __r;
4267}
4268
4269template<class _Tp>
4270template<class _A0, class _A1>
4271shared_ptr<_Tp>
4272shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1)
4273{
4274    static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in make_shared" );
4275    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4276    typedef allocator<_CntrlBlk> _Alloc2;
4277    typedef __allocator_destructor<_Alloc2> _D2;
4278    _Alloc2 __alloc2;
4279    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4280    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1);
4281    shared_ptr<_Tp> __r;
4282    __r.__ptr_ = __hold2.get()->get();
4283    __r.__cntrl_ = __hold2.release();
4284    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4285    return __r;
4286}
4287
4288template<class _Tp>
4289template<class _A0, class _A1, class _A2>
4290shared_ptr<_Tp>
4291shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
4292{
4293    static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in make_shared" );
4294    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4295    typedef allocator<_CntrlBlk> _Alloc2;
4296    typedef __allocator_destructor<_Alloc2> _D2;
4297    _Alloc2 __alloc2;
4298    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4299    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1, __a2);
4300    shared_ptr<_Tp> __r;
4301    __r.__ptr_ = __hold2.get()->get();
4302    __r.__cntrl_ = __hold2.release();
4303    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4304    return __r;
4305}
4306
4307template<class _Tp>
4308template<class _Alloc>
4309shared_ptr<_Tp>
4310shared_ptr<_Tp>::allocate_shared(const _Alloc& __a)
4311{
4312    static_assert((is_constructible<_Tp>::value), "Can't construct object in allocate_shared" );
4313    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4314    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4315    typedef __allocator_destructor<_Alloc2> _D2;
4316    _Alloc2 __alloc2(__a);
4317    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4318    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4319        _CntrlBlk(__a);
4320    shared_ptr<_Tp> __r;
4321    __r.__ptr_ = __hold2.get()->get();
4322    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4323    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4324    return __r;
4325}
4326
4327template<class _Tp>
4328template<class _Alloc, class _A0>
4329shared_ptr<_Tp>
4330shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0)
4331{
4332    static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in allocate_shared" );
4333    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4334    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4335    typedef __allocator_destructor<_Alloc2> _D2;
4336    _Alloc2 __alloc2(__a);
4337    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4338    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4339        _CntrlBlk(__a, __a0);
4340    shared_ptr<_Tp> __r;
4341    __r.__ptr_ = __hold2.get()->get();
4342    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4343    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4344    return __r;
4345}
4346
4347template<class _Tp>
4348template<class _Alloc, class _A0, class _A1>
4349shared_ptr<_Tp>
4350shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
4351{
4352    static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in allocate_shared" );
4353    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4354    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4355    typedef __allocator_destructor<_Alloc2> _D2;
4356    _Alloc2 __alloc2(__a);
4357    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4358    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4359        _CntrlBlk(__a, __a0, __a1);
4360    shared_ptr<_Tp> __r;
4361    __r.__ptr_ = __hold2.get()->get();
4362    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4363    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4364    return __r;
4365}
4366
4367template<class _Tp>
4368template<class _Alloc, class _A0, class _A1, class _A2>
4369shared_ptr<_Tp>
4370shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
4371{
4372    static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in allocate_shared" );
4373    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4374    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4375    typedef __allocator_destructor<_Alloc2> _D2;
4376    _Alloc2 __alloc2(__a);
4377    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4378    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4379        _CntrlBlk(__a, __a0, __a1, __a2);
4380    shared_ptr<_Tp> __r;
4381    __r.__ptr_ = __hold2.get()->get();
4382    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4383    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4384    return __r;
4385}
4386
4387#endif  // _LIBCPP_HAS_NO_VARIADICS
4388
4389template<class _Tp>
4390shared_ptr<_Tp>::~shared_ptr()
4391{
4392    if (__cntrl_)
4393        __cntrl_->__release_shared();
4394}
4395
4396template<class _Tp>
4397inline
4398shared_ptr<_Tp>&
4399shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
4400{
4401    shared_ptr(__r).swap(*this);
4402    return *this;
4403}
4404
4405template<class _Tp>
4406template<class _Yp>
4407inline
4408typename enable_if
4409<
4410    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4411    shared_ptr<_Tp>&
4412>::type
4413shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
4414{
4415    shared_ptr(__r).swap(*this);
4416    return *this;
4417}
4418
4419#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4420
4421template<class _Tp>
4422inline
4423shared_ptr<_Tp>&
4424shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
4425{
4426    shared_ptr(_VSTD::move(__r)).swap(*this);
4427    return *this;
4428}
4429
4430template<class _Tp>
4431template<class _Yp>
4432inline
4433typename enable_if
4434<
4435    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4436    shared_ptr<_Tp>&
4437>::type
4438shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
4439{
4440    shared_ptr(_VSTD::move(__r)).swap(*this);
4441    return *this;
4442}
4443
4444#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4445template<class _Tp>
4446template<class _Yp>
4447inline
4448typename enable_if
4449<
4450    !is_array<_Yp>::value &&
4451    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4452    shared_ptr<_Tp>
4453>::type&
4454shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
4455{
4456    shared_ptr(_VSTD::move(__r)).swap(*this);
4457    return *this;
4458}
4459#endif
4460
4461template<class _Tp>
4462template <class _Yp, class _Dp>
4463inline
4464typename enable_if
4465<
4466    !is_array<_Yp>::value &&
4467    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4468                   typename shared_ptr<_Tp>::element_type*>::value,
4469    shared_ptr<_Tp>&
4470>::type
4471shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
4472{
4473    shared_ptr(_VSTD::move(__r)).swap(*this);
4474    return *this;
4475}
4476
4477#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4478
4479#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4480template<class _Tp>
4481template<class _Yp>
4482inline _LIBCPP_INLINE_VISIBILITY
4483typename enable_if
4484<
4485    !is_array<_Yp>::value &&
4486    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4487    shared_ptr<_Tp>&
4488>::type
4489shared_ptr<_Tp>::operator=(auto_ptr<_Yp> __r)
4490{
4491    shared_ptr(__r).swap(*this);
4492    return *this;
4493}
4494#endif
4495
4496template<class _Tp>
4497template <class _Yp, class _Dp>
4498inline _LIBCPP_INLINE_VISIBILITY
4499typename enable_if
4500<
4501    !is_array<_Yp>::value &&
4502    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4503                   typename shared_ptr<_Tp>::element_type*>::value,
4504    shared_ptr<_Tp>&
4505>::type
4506shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp> __r)
4507{
4508    shared_ptr(_VSTD::move(__r)).swap(*this);
4509    return *this;
4510}
4511
4512#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4513
4514template<class _Tp>
4515inline
4516void
4517shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
4518{
4519    _VSTD::swap(__ptr_, __r.__ptr_);
4520    _VSTD::swap(__cntrl_, __r.__cntrl_);
4521}
4522
4523template<class _Tp>
4524inline
4525void
4526shared_ptr<_Tp>::reset() _NOEXCEPT
4527{
4528    shared_ptr().swap(*this);
4529}
4530
4531template<class _Tp>
4532template<class _Yp>
4533inline
4534typename enable_if
4535<
4536    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4537    void
4538>::type
4539shared_ptr<_Tp>::reset(_Yp* __p)
4540{
4541    shared_ptr(__p).swap(*this);
4542}
4543
4544template<class _Tp>
4545template<class _Yp, class _Dp>
4546inline
4547typename enable_if
4548<
4549    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4550    void
4551>::type
4552shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
4553{
4554    shared_ptr(__p, __d).swap(*this);
4555}
4556
4557template<class _Tp>
4558template<class _Yp, class _Dp, class _Alloc>
4559inline
4560typename enable_if
4561<
4562    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4563    void
4564>::type
4565shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
4566{
4567    shared_ptr(__p, __d, __a).swap(*this);
4568}
4569
4570#ifndef _LIBCPP_HAS_NO_VARIADICS
4571
4572template<class _Tp, class ..._Args>
4573inline _LIBCPP_INLINE_VISIBILITY
4574typename enable_if
4575<
4576    !is_array<_Tp>::value,
4577    shared_ptr<_Tp>
4578>::type
4579make_shared(_Args&& ...__args)
4580{
4581    return shared_ptr<_Tp>::make_shared(_VSTD::forward<_Args>(__args)...);
4582}
4583
4584template<class _Tp, class _Alloc, class ..._Args>
4585inline _LIBCPP_INLINE_VISIBILITY
4586typename enable_if
4587<
4588    !is_array<_Tp>::value,
4589    shared_ptr<_Tp>
4590>::type
4591allocate_shared(const _Alloc& __a, _Args&& ...__args)
4592{
4593    return shared_ptr<_Tp>::allocate_shared(__a, _VSTD::forward<_Args>(__args)...);
4594}
4595
4596#else  // _LIBCPP_HAS_NO_VARIADICS
4597
4598template<class _Tp>
4599inline _LIBCPP_INLINE_VISIBILITY
4600shared_ptr<_Tp>
4601make_shared()
4602{
4603    return shared_ptr<_Tp>::make_shared();
4604}
4605
4606template<class _Tp, class _A0>
4607inline _LIBCPP_INLINE_VISIBILITY
4608shared_ptr<_Tp>
4609make_shared(_A0& __a0)
4610{
4611    return shared_ptr<_Tp>::make_shared(__a0);
4612}
4613
4614template<class _Tp, class _A0, class _A1>
4615inline _LIBCPP_INLINE_VISIBILITY
4616shared_ptr<_Tp>
4617make_shared(_A0& __a0, _A1& __a1)
4618{
4619    return shared_ptr<_Tp>::make_shared(__a0, __a1);
4620}
4621
4622template<class _Tp, class _A0, class _A1, class _A2>
4623inline _LIBCPP_INLINE_VISIBILITY
4624shared_ptr<_Tp>
4625make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
4626{
4627    return shared_ptr<_Tp>::make_shared(__a0, __a1, __a2);
4628}
4629
4630template<class _Tp, class _Alloc>
4631inline _LIBCPP_INLINE_VISIBILITY
4632shared_ptr<_Tp>
4633allocate_shared(const _Alloc& __a)
4634{
4635    return shared_ptr<_Tp>::allocate_shared(__a);
4636}
4637
4638template<class _Tp, class _Alloc, class _A0>
4639inline _LIBCPP_INLINE_VISIBILITY
4640shared_ptr<_Tp>
4641allocate_shared(const _Alloc& __a, _A0& __a0)
4642{
4643    return shared_ptr<_Tp>::allocate_shared(__a, __a0);
4644}
4645
4646template<class _Tp, class _Alloc, class _A0, class _A1>
4647inline _LIBCPP_INLINE_VISIBILITY
4648shared_ptr<_Tp>
4649allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
4650{
4651    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1);
4652}
4653
4654template<class _Tp, class _Alloc, class _A0, class _A1, class _A2>
4655inline _LIBCPP_INLINE_VISIBILITY
4656shared_ptr<_Tp>
4657allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
4658{
4659    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1, __a2);
4660}
4661
4662#endif  // _LIBCPP_HAS_NO_VARIADICS
4663
4664template<class _Tp, class _Up>
4665inline _LIBCPP_INLINE_VISIBILITY
4666bool
4667operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4668{
4669    return __x.get() == __y.get();
4670}
4671
4672template<class _Tp, class _Up>
4673inline _LIBCPP_INLINE_VISIBILITY
4674bool
4675operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4676{
4677    return !(__x == __y);
4678}
4679
4680template<class _Tp, class _Up>
4681inline _LIBCPP_INLINE_VISIBILITY
4682bool
4683operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4684{
4685#if _LIBCPP_STD_VER <= 11
4686    typedef typename common_type<_Tp*, _Up*>::type _Vp;
4687    return less<_Vp>()(__x.get(), __y.get());
4688#else
4689    return less<>()(__x.get(), __y.get());
4690#endif
4691
4692}
4693
4694template<class _Tp, class _Up>
4695inline _LIBCPP_INLINE_VISIBILITY
4696bool
4697operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4698{
4699    return __y < __x;
4700}
4701
4702template<class _Tp, class _Up>
4703inline _LIBCPP_INLINE_VISIBILITY
4704bool
4705operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4706{
4707    return !(__y < __x);
4708}
4709
4710template<class _Tp, class _Up>
4711inline _LIBCPP_INLINE_VISIBILITY
4712bool
4713operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4714{
4715    return !(__x < __y);
4716}
4717
4718template<class _Tp>
4719inline _LIBCPP_INLINE_VISIBILITY
4720bool
4721operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4722{
4723    return !__x;
4724}
4725
4726template<class _Tp>
4727inline _LIBCPP_INLINE_VISIBILITY
4728bool
4729operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4730{
4731    return !__x;
4732}
4733
4734template<class _Tp>
4735inline _LIBCPP_INLINE_VISIBILITY
4736bool
4737operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4738{
4739    return static_cast<bool>(__x);
4740}
4741
4742template<class _Tp>
4743inline _LIBCPP_INLINE_VISIBILITY
4744bool
4745operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4746{
4747    return static_cast<bool>(__x);
4748}
4749
4750template<class _Tp>
4751inline _LIBCPP_INLINE_VISIBILITY
4752bool
4753operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4754{
4755    return less<_Tp*>()(__x.get(), nullptr);
4756}
4757
4758template<class _Tp>
4759inline _LIBCPP_INLINE_VISIBILITY
4760bool
4761operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4762{
4763    return less<_Tp*>()(nullptr, __x.get());
4764}
4765
4766template<class _Tp>
4767inline _LIBCPP_INLINE_VISIBILITY
4768bool
4769operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4770{
4771    return nullptr < __x;
4772}
4773
4774template<class _Tp>
4775inline _LIBCPP_INLINE_VISIBILITY
4776bool
4777operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4778{
4779    return __x < nullptr;
4780}
4781
4782template<class _Tp>
4783inline _LIBCPP_INLINE_VISIBILITY
4784bool
4785operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4786{
4787    return !(nullptr < __x);
4788}
4789
4790template<class _Tp>
4791inline _LIBCPP_INLINE_VISIBILITY
4792bool
4793operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4794{
4795    return !(__x < nullptr);
4796}
4797
4798template<class _Tp>
4799inline _LIBCPP_INLINE_VISIBILITY
4800bool
4801operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4802{
4803    return !(__x < nullptr);
4804}
4805
4806template<class _Tp>
4807inline _LIBCPP_INLINE_VISIBILITY
4808bool
4809operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4810{
4811    return !(nullptr < __x);
4812}
4813
4814template<class _Tp>
4815inline _LIBCPP_INLINE_VISIBILITY
4816void
4817swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
4818{
4819    __x.swap(__y);
4820}
4821
4822template<class _Tp, class _Up>
4823inline _LIBCPP_INLINE_VISIBILITY
4824typename enable_if
4825<
4826    !is_array<_Tp>::value && !is_array<_Up>::value,
4827    shared_ptr<_Tp>
4828>::type
4829static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4830{
4831    return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get()));
4832}
4833
4834template<class _Tp, class _Up>
4835inline _LIBCPP_INLINE_VISIBILITY
4836typename enable_if
4837<
4838    !is_array<_Tp>::value && !is_array<_Up>::value,
4839    shared_ptr<_Tp>
4840>::type
4841dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4842{
4843    _Tp* __p = dynamic_cast<_Tp*>(__r.get());
4844    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
4845}
4846
4847template<class _Tp, class _Up>
4848typename enable_if
4849<
4850    is_array<_Tp>::value == is_array<_Up>::value,
4851    shared_ptr<_Tp>
4852>::type
4853const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4854{
4855    typedef typename remove_extent<_Tp>::type _RTp;
4856    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
4857}
4858
4859#ifndef _LIBCPP_NO_RTTI
4860
4861template<class _Dp, class _Tp>
4862inline _LIBCPP_INLINE_VISIBILITY
4863_Dp*
4864get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
4865{
4866    return __p.template __get_deleter<_Dp>();
4867}
4868
4869#endif  // _LIBCPP_NO_RTTI
4870
4871template<class _Tp>
4872class _LIBCPP_TEMPLATE_VIS weak_ptr
4873{
4874public:
4875    typedef _Tp element_type;
4876private:
4877    element_type*        __ptr_;
4878    __shared_weak_count* __cntrl_;
4879
4880public:
4881    _LIBCPP_INLINE_VISIBILITY
4882    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
4883    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r,
4884                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4885                        _NOEXCEPT;
4886    _LIBCPP_INLINE_VISIBILITY
4887    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
4888    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r,
4889                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4890                         _NOEXCEPT;
4891
4892#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4893    _LIBCPP_INLINE_VISIBILITY
4894    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
4895    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r,
4896                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4897                         _NOEXCEPT;
4898#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4899    ~weak_ptr();
4900
4901    _LIBCPP_INLINE_VISIBILITY
4902    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
4903    template<class _Yp>
4904        typename enable_if
4905        <
4906            is_convertible<_Yp*, element_type*>::value,
4907            weak_ptr&
4908        >::type
4909        _LIBCPP_INLINE_VISIBILITY
4910        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
4911
4912#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4913
4914    _LIBCPP_INLINE_VISIBILITY
4915    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
4916    template<class _Yp>
4917        typename enable_if
4918        <
4919            is_convertible<_Yp*, element_type*>::value,
4920            weak_ptr&
4921        >::type
4922        _LIBCPP_INLINE_VISIBILITY
4923        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
4924
4925#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4926
4927    template<class _Yp>
4928        typename enable_if
4929        <
4930            is_convertible<_Yp*, element_type*>::value,
4931            weak_ptr&
4932        >::type
4933        _LIBCPP_INLINE_VISIBILITY
4934        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
4935
4936    _LIBCPP_INLINE_VISIBILITY
4937    void swap(weak_ptr& __r) _NOEXCEPT;
4938    _LIBCPP_INLINE_VISIBILITY
4939    void reset() _NOEXCEPT;
4940
4941    _LIBCPP_INLINE_VISIBILITY
4942    long use_count() const _NOEXCEPT
4943        {return __cntrl_ ? __cntrl_->use_count() : 0;}
4944    _LIBCPP_INLINE_VISIBILITY
4945    bool expired() const _NOEXCEPT
4946        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
4947    shared_ptr<_Tp> lock() const _NOEXCEPT;
4948    template<class _Up>
4949        _LIBCPP_INLINE_VISIBILITY
4950        bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT
4951        {return __cntrl_ < __r.__cntrl_;}
4952    template<class _Up>
4953        _LIBCPP_INLINE_VISIBILITY
4954        bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT
4955        {return __cntrl_ < __r.__cntrl_;}
4956
4957    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
4958    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
4959};
4960
4961template<class _Tp>
4962inline
4963_LIBCPP_CONSTEXPR
4964weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
4965    : __ptr_(0),
4966      __cntrl_(0)
4967{
4968}
4969
4970template<class _Tp>
4971inline
4972weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
4973    : __ptr_(__r.__ptr_),
4974      __cntrl_(__r.__cntrl_)
4975{
4976    if (__cntrl_)
4977        __cntrl_->__add_weak();
4978}
4979
4980template<class _Tp>
4981template<class _Yp>
4982inline
4983weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
4984                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4985                         _NOEXCEPT
4986    : __ptr_(__r.__ptr_),
4987      __cntrl_(__r.__cntrl_)
4988{
4989    if (__cntrl_)
4990        __cntrl_->__add_weak();
4991}
4992
4993template<class _Tp>
4994template<class _Yp>
4995inline
4996weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
4997                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4998         _NOEXCEPT
4999    : __ptr_(__r.__ptr_),
5000      __cntrl_(__r.__cntrl_)
5001{
5002    if (__cntrl_)
5003        __cntrl_->__add_weak();
5004}
5005
5006#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5007
5008template<class _Tp>
5009inline
5010weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
5011    : __ptr_(__r.__ptr_),
5012      __cntrl_(__r.__cntrl_)
5013{
5014    __r.__ptr_ = 0;
5015    __r.__cntrl_ = 0;
5016}
5017
5018template<class _Tp>
5019template<class _Yp>
5020inline
5021weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
5022                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5023         _NOEXCEPT
5024    : __ptr_(__r.__ptr_),
5025      __cntrl_(__r.__cntrl_)
5026{
5027    __r.__ptr_ = 0;
5028    __r.__cntrl_ = 0;
5029}
5030
5031#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5032
5033template<class _Tp>
5034weak_ptr<_Tp>::~weak_ptr()
5035{
5036    if (__cntrl_)
5037        __cntrl_->__release_weak();
5038}
5039
5040template<class _Tp>
5041inline
5042weak_ptr<_Tp>&
5043weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
5044{
5045    weak_ptr(__r).swap(*this);
5046    return *this;
5047}
5048
5049template<class _Tp>
5050template<class _Yp>
5051inline
5052typename enable_if
5053<
5054    is_convertible<_Yp*, _Tp*>::value,
5055    weak_ptr<_Tp>&
5056>::type
5057weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
5058{
5059    weak_ptr(__r).swap(*this);
5060    return *this;
5061}
5062
5063#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5064
5065template<class _Tp>
5066inline
5067weak_ptr<_Tp>&
5068weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
5069{
5070    weak_ptr(_VSTD::move(__r)).swap(*this);
5071    return *this;
5072}
5073
5074template<class _Tp>
5075template<class _Yp>
5076inline
5077typename enable_if
5078<
5079    is_convertible<_Yp*, _Tp*>::value,
5080    weak_ptr<_Tp>&
5081>::type
5082weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
5083{
5084    weak_ptr(_VSTD::move(__r)).swap(*this);
5085    return *this;
5086}
5087
5088#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5089
5090template<class _Tp>
5091template<class _Yp>
5092inline
5093typename enable_if
5094<
5095    is_convertible<_Yp*, _Tp*>::value,
5096    weak_ptr<_Tp>&
5097>::type
5098weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
5099{
5100    weak_ptr(__r).swap(*this);
5101    return *this;
5102}
5103
5104template<class _Tp>
5105inline
5106void
5107weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
5108{
5109    _VSTD::swap(__ptr_, __r.__ptr_);
5110    _VSTD::swap(__cntrl_, __r.__cntrl_);
5111}
5112
5113template<class _Tp>
5114inline _LIBCPP_INLINE_VISIBILITY
5115void
5116swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
5117{
5118    __x.swap(__y);
5119}
5120
5121template<class _Tp>
5122inline
5123void
5124weak_ptr<_Tp>::reset() _NOEXCEPT
5125{
5126    weak_ptr().swap(*this);
5127}
5128
5129template<class _Tp>
5130template<class _Yp>
5131shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
5132                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
5133    : __ptr_(__r.__ptr_),
5134      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
5135{
5136    if (__cntrl_ == 0)
5137        __throw_bad_weak_ptr();
5138}
5139
5140template<class _Tp>
5141shared_ptr<_Tp>
5142weak_ptr<_Tp>::lock() const _NOEXCEPT
5143{
5144    shared_ptr<_Tp> __r;
5145    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
5146    if (__r.__cntrl_)
5147        __r.__ptr_ = __ptr_;
5148    return __r;
5149}
5150
5151#if _LIBCPP_STD_VER > 14
5152template <class _Tp = void> struct owner_less;
5153#else
5154template <class _Tp> struct owner_less;
5155#endif
5156
5157template <class _Tp>
5158struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> >
5159    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
5160{
5161    typedef bool result_type;
5162    _LIBCPP_INLINE_VISIBILITY
5163    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
5164        {return __x.owner_before(__y);}
5165    _LIBCPP_INLINE_VISIBILITY
5166    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
5167        {return __x.owner_before(__y);}
5168    _LIBCPP_INLINE_VISIBILITY
5169    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
5170        {return __x.owner_before(__y);}
5171};
5172
5173template <class _Tp>
5174struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> >
5175    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
5176{
5177    typedef bool result_type;
5178    _LIBCPP_INLINE_VISIBILITY
5179    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
5180        {return __x.owner_before(__y);}
5181    _LIBCPP_INLINE_VISIBILITY
5182    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
5183        {return __x.owner_before(__y);}
5184    _LIBCPP_INLINE_VISIBILITY
5185    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
5186        {return __x.owner_before(__y);}
5187};
5188
5189#if _LIBCPP_STD_VER > 14
5190template <>
5191struct _LIBCPP_TEMPLATE_VIS owner_less<void>
5192{
5193    template <class _Tp, class _Up>
5194    _LIBCPP_INLINE_VISIBILITY
5195    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
5196        {return __x.owner_before(__y);}
5197    template <class _Tp, class _Up>
5198    _LIBCPP_INLINE_VISIBILITY
5199    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
5200        {return __x.owner_before(__y);}
5201    template <class _Tp, class _Up>
5202    _LIBCPP_INLINE_VISIBILITY
5203    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
5204        {return __x.owner_before(__y);}
5205    template <class _Tp, class _Up>
5206    _LIBCPP_INLINE_VISIBILITY
5207    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
5208        {return __x.owner_before(__y);}
5209    typedef void is_transparent;
5210};
5211#endif
5212
5213template<class _Tp>
5214class _LIBCPP_TEMPLATE_VIS enable_shared_from_this
5215{
5216    mutable weak_ptr<_Tp> __weak_this_;
5217protected:
5218    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
5219    enable_shared_from_this() _NOEXCEPT {}
5220    _LIBCPP_INLINE_VISIBILITY
5221    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
5222    _LIBCPP_INLINE_VISIBILITY
5223    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
5224        {return *this;}
5225    _LIBCPP_INLINE_VISIBILITY
5226    ~enable_shared_from_this() {}
5227public:
5228    _LIBCPP_INLINE_VISIBILITY
5229    shared_ptr<_Tp> shared_from_this()
5230        {return shared_ptr<_Tp>(__weak_this_);}
5231    _LIBCPP_INLINE_VISIBILITY
5232    shared_ptr<_Tp const> shared_from_this() const
5233        {return shared_ptr<const _Tp>(__weak_this_);}
5234
5235#if _LIBCPP_STD_VER > 14
5236    _LIBCPP_INLINE_VISIBILITY
5237    weak_ptr<_Tp> weak_from_this() _NOEXCEPT
5238       { return __weak_this_; }
5239
5240    _LIBCPP_INLINE_VISIBILITY
5241    weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT
5242        { return __weak_this_; }
5243#endif // _LIBCPP_STD_VER > 14
5244
5245    template <class _Up> friend class shared_ptr;
5246};
5247
5248template <class _Tp>
5249struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> >
5250{
5251    typedef shared_ptr<_Tp>      argument_type;
5252    typedef size_t               result_type;
5253
5254    _LIBCPP_INLINE_VISIBILITY
5255    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
5256    {
5257        return hash<_Tp*>()(__ptr.get());
5258    }
5259};
5260
5261template<class _CharT, class _Traits, class _Yp>
5262inline _LIBCPP_INLINE_VISIBILITY
5263basic_ostream<_CharT, _Traits>&
5264operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
5265
5266
5267#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
5268
5269class _LIBCPP_TYPE_VIS __sp_mut
5270{
5271    void* __lx;
5272public:
5273    void lock() _NOEXCEPT;
5274    void unlock() _NOEXCEPT;
5275
5276private:
5277    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
5278    __sp_mut(const __sp_mut&);
5279    __sp_mut& operator=(const __sp_mut&);
5280
5281    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
5282};
5283
5284_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5285__sp_mut& __get_sp_mut(const void*);
5286
5287template <class _Tp>
5288inline _LIBCPP_INLINE_VISIBILITY
5289bool
5290atomic_is_lock_free(const shared_ptr<_Tp>*)
5291{
5292    return false;
5293}
5294
5295template <class _Tp>
5296_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5297shared_ptr<_Tp>
5298atomic_load(const shared_ptr<_Tp>* __p)
5299{
5300    __sp_mut& __m = __get_sp_mut(__p);
5301    __m.lock();
5302    shared_ptr<_Tp> __q = *__p;
5303    __m.unlock();
5304    return __q;
5305}
5306
5307template <class _Tp>
5308inline _LIBCPP_INLINE_VISIBILITY
5309_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5310shared_ptr<_Tp>
5311atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
5312{
5313    return atomic_load(__p);
5314}
5315
5316template <class _Tp>
5317_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5318void
5319atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5320{
5321    __sp_mut& __m = __get_sp_mut(__p);
5322    __m.lock();
5323    __p->swap(__r);
5324    __m.unlock();
5325}
5326
5327template <class _Tp>
5328inline _LIBCPP_INLINE_VISIBILITY
5329_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5330void
5331atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5332{
5333    atomic_store(__p, __r);
5334}
5335
5336template <class _Tp>
5337_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5338shared_ptr<_Tp>
5339atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5340{
5341    __sp_mut& __m = __get_sp_mut(__p);
5342    __m.lock();
5343    __p->swap(__r);
5344    __m.unlock();
5345    return __r;
5346}
5347
5348template <class _Tp>
5349inline _LIBCPP_INLINE_VISIBILITY
5350_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5351shared_ptr<_Tp>
5352atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5353{
5354    return atomic_exchange(__p, __r);
5355}
5356
5357template <class _Tp>
5358_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5359bool
5360atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5361{
5362    shared_ptr<_Tp> __temp;
5363    __sp_mut& __m = __get_sp_mut(__p);
5364    __m.lock();
5365    if (__p->__owner_equivalent(*__v))
5366    {
5367        _VSTD::swap(__temp, *__p);
5368        *__p = __w;
5369        __m.unlock();
5370        return true;
5371    }
5372    _VSTD::swap(__temp, *__v);
5373    *__v = *__p;
5374    __m.unlock();
5375    return false;
5376}
5377
5378template <class _Tp>
5379inline _LIBCPP_INLINE_VISIBILITY
5380_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5381bool
5382atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5383{
5384    return atomic_compare_exchange_strong(__p, __v, __w);
5385}
5386
5387template <class _Tp>
5388inline _LIBCPP_INLINE_VISIBILITY
5389_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5390bool
5391atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5392                                        shared_ptr<_Tp> __w, memory_order, memory_order)
5393{
5394    return atomic_compare_exchange_strong(__p, __v, __w);
5395}
5396
5397template <class _Tp>
5398inline _LIBCPP_INLINE_VISIBILITY
5399_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5400bool
5401atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5402                                      shared_ptr<_Tp> __w, memory_order, memory_order)
5403{
5404    return atomic_compare_exchange_weak(__p, __v, __w);
5405}
5406
5407#endif  // !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
5408
5409//enum class
5410#if defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE)
5411# ifndef _LIBCPP_CXX03_LANG
5412enum class pointer_safety : unsigned char {
5413  relaxed,
5414  preferred,
5415  strict
5416};
5417# endif
5418#else
5419struct _LIBCPP_TYPE_VIS pointer_safety
5420{
5421    enum __lx
5422    {
5423        relaxed,
5424        preferred,
5425        strict
5426    };
5427
5428    __lx __v_;
5429
5430    _LIBCPP_INLINE_VISIBILITY
5431    pointer_safety() : __v_() {}
5432
5433    _LIBCPP_INLINE_VISIBILITY
5434    pointer_safety(__lx __v) : __v_(__v) {}
5435    _LIBCPP_INLINE_VISIBILITY
5436    operator int() const {return __v_;}
5437};
5438#endif
5439
5440#if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) && \
5441    defined(_LIBCPP_BUILDING_LIBRARY)
5442_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
5443#else
5444// This function is only offered in C++03 under ABI v1.
5445# if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) || !defined(_LIBCPP_CXX03_LANG)
5446inline _LIBCPP_INLINE_VISIBILITY
5447pointer_safety get_pointer_safety() _NOEXCEPT {
5448  return pointer_safety::relaxed;
5449}
5450# endif
5451#endif
5452
5453
5454_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
5455_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
5456_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
5457_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
5458
5459template <class _Tp>
5460inline _LIBCPP_INLINE_VISIBILITY
5461_Tp*
5462undeclare_reachable(_Tp* __p)
5463{
5464    return static_cast<_Tp*>(__undeclare_reachable(__p));
5465}
5466
5467_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
5468
5469// --- Helper for container swap --
5470template <typename _Alloc>
5471inline _LIBCPP_INLINE_VISIBILITY
5472void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
5473#if _LIBCPP_STD_VER >= 14
5474    _NOEXCEPT
5475#else
5476    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5477#endif
5478{
5479    __swap_allocator(__a1, __a2,
5480      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
5481}
5482
5483template <typename _Alloc>
5484_LIBCPP_INLINE_VISIBILITY
5485void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
5486#if _LIBCPP_STD_VER >= 14
5487    _NOEXCEPT
5488#else
5489    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5490#endif
5491{
5492    using _VSTD::swap;
5493    swap(__a1, __a2);
5494}
5495
5496template <typename _Alloc>
5497inline _LIBCPP_INLINE_VISIBILITY
5498void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
5499
5500template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
5501struct __noexcept_move_assign_container : public integral_constant<bool,
5502    _Traits::propagate_on_container_move_assignment::value
5503#if _LIBCPP_STD_VER > 14
5504        || _Traits::is_always_equal::value
5505#else
5506        && is_nothrow_move_assignable<_Alloc>::value
5507#endif
5508    > {};
5509
5510
5511#ifndef _LIBCPP_HAS_NO_VARIADICS
5512template <class _Tp, class _Alloc>
5513struct __temp_value {
5514    typedef allocator_traits<_Alloc> _Traits;
5515
5516    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
5517    _Alloc &__a;
5518
5519    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
5520    _Tp &   get() { return *__addr(); }
5521
5522    template<class... _Args>
5523    _LIBCPP_NO_CFI
5524    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
5525      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
5526                         _VSTD::forward<_Args>(__args)...);
5527    }
5528
5529    ~__temp_value() { _Traits::destroy(__a, __addr()); }
5530    };
5531#endif
5532
5533template<typename _Alloc, typename = void, typename = void>
5534struct __is_allocator : false_type {};
5535
5536template<typename _Alloc>
5537struct __is_allocator<_Alloc,
5538       typename __void_t<typename _Alloc::value_type>::type,
5539       typename __void_t<decltype(_VSTD::declval<_Alloc&>().allocate(size_t(0)))>::type
5540     >
5541   : true_type {};
5542
5543// __builtin_new_allocator -- A non-templated helper for allocating and
5544// deallocating memory using __builtin_operator_new and
5545// __builtin_operator_delete. It should be used in preference to
5546// `std::allocator<T>` to avoid additional instantiations.
5547struct __builtin_new_allocator {
5548  struct __builtin_new_deleter {
5549    typedef void* pointer_type;
5550
5551    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
5552        : __size_(__size), __align_(__align) {}
5553
5554    void operator()(void* p) const _NOEXCEPT {
5555        std::__libcpp_deallocate(p, __size_, __align_);
5556    }
5557
5558   private:
5559    size_t __size_;
5560    size_t __align_;
5561  };
5562
5563  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
5564
5565  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
5566      return __holder_t(std::__libcpp_allocate(__s, __align),
5567                     __builtin_new_deleter(__s, __align));
5568  }
5569
5570  static void __deallocate_bytes(void* __p, size_t __s,
5571                                 size_t __align) _NOEXCEPT {
5572      std::__libcpp_deallocate(__p, __s, __align);
5573  }
5574
5575  template <class _Tp>
5576  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5577  static __holder_t __allocate_type(size_t __n) {
5578      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5579  }
5580
5581  template <class _Tp>
5582  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5583  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
5584      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5585  }
5586};
5587
5588
5589_LIBCPP_END_NAMESPACE_STD
5590
5591_LIBCPP_POP_MACROS
5592
5593#endif  // _LIBCPP_MEMORY
5594