xref: /llvm-project-15.0.7/libcxx/include/memory (revision ea5cd3b4)
1// -*- C++ -*-
2//===-------------------------- memory ------------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_MEMORY
12#define _LIBCPP_MEMORY
13
14/*
15    memory synopsis
16
17namespace std
18{
19
20struct allocator_arg_t { };
21inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();
22
23template <class T, class Alloc> struct uses_allocator;
24
25template <class Ptr>
26struct pointer_traits
27{
28    typedef Ptr pointer;
29    typedef <details> element_type;
30    typedef <details> difference_type;
31
32    template <class U> using rebind = <details>;
33
34    static pointer pointer_to(<details>);
35};
36
37template <class T>
38struct pointer_traits<T*>
39{
40    typedef T* pointer;
41    typedef T element_type;
42    typedef ptrdiff_t difference_type;
43
44    template <class U> using rebind = U*;
45
46    static pointer pointer_to(<details>) noexcept;
47};
48
49template <class T> constexpr T* to_address(T* p) noexcept; // C++20
50template <class Ptr> auto to_address(const Ptr& p) noexcept; // C++20
51
52template <class Alloc>
53struct allocator_traits
54{
55    typedef Alloc                        allocator_type;
56    typedef typename allocator_type::value_type
57                                         value_type;
58
59    typedef Alloc::pointer | value_type* pointer;
60    typedef Alloc::const_pointer
61          | pointer_traits<pointer>::rebind<const value_type>
62                                         const_pointer;
63    typedef Alloc::void_pointer
64          | pointer_traits<pointer>::rebind<void>
65                                         void_pointer;
66    typedef Alloc::const_void_pointer
67          | pointer_traits<pointer>::rebind<const void>
68                                         const_void_pointer;
69    typedef Alloc::difference_type
70          | pointer_traits<pointer>::difference_type
71                                         difference_type;
72    typedef Alloc::size_type
73          | make_unsigned<difference_type>::type
74                                         size_type;
75    typedef Alloc::propagate_on_container_copy_assignment
76          | false_type                   propagate_on_container_copy_assignment;
77    typedef Alloc::propagate_on_container_move_assignment
78          | false_type                   propagate_on_container_move_assignment;
79    typedef Alloc::propagate_on_container_swap
80          | false_type                   propagate_on_container_swap;
81    typedef Alloc::is_always_equal
82          | is_empty                     is_always_equal;
83
84    template <class T> using rebind_alloc  = Alloc::rebind<U>::other | Alloc<T, Args...>;
85    template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
86
87    static pointer allocate(allocator_type& a, size_type n);                          // [[nodiscard]] in C++20
88    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint); // [[nodiscard]] in C++20
89
90    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept;
91
92    template <class T, class... Args>
93        static void construct(allocator_type& a, T* p, Args&&... args);
94
95    template <class T>
96        static void destroy(allocator_type& a, T* p);
97
98    static size_type max_size(const allocator_type& a); // noexcept in C++14
99
100    static allocator_type
101        select_on_container_copy_construction(const allocator_type& a);
102};
103
104template <>
105class allocator<void>
106{
107public:
108    typedef void*                                 pointer;
109    typedef const void*                           const_pointer;
110    typedef void                                  value_type;
111
112    template <class _Up> struct rebind {typedef allocator<_Up> other;};
113};
114
115template <class T>
116class allocator
117{
118public:
119    typedef size_t                                size_type;
120    typedef ptrdiff_t                             difference_type;
121    typedef T*                                    pointer;
122    typedef const T*                              const_pointer;
123    typedef typename add_lvalue_reference<T>::type       reference;
124    typedef typename add_lvalue_reference<const T>::type const_reference;
125    typedef T                                     value_type;
126
127    template <class U> struct rebind {typedef allocator<U> other;};
128
129    constexpr allocator() noexcept;                      // constexpr in C++20
130    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
131    template <class U>
132      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
133    ~allocator();
134    pointer address(reference x) const noexcept;
135    const_pointer address(const_reference x) const noexcept;
136    pointer allocate(size_type, allocator<void>::const_pointer hint = 0);
137    void deallocate(pointer p, size_type n) noexcept;
138    size_type max_size() const noexcept;
139    template<class U, class... Args>
140        void construct(U* p, Args&&... args);
141    template <class U>
142        void destroy(U* p);
143};
144
145template <class T, class U>
146bool operator==(const allocator<T>&, const allocator<U>&) noexcept;
147
148template <class T, class U>
149bool operator!=(const allocator<T>&, const allocator<U>&) noexcept;
150
151template <class OutputIterator, class T>
152class raw_storage_iterator
153    : public iterator<output_iterator_tag,
154                      T,                               // purposefully not C++03
155                      ptrdiff_t,                       // purposefully not C++03
156                      T*,                              // purposefully not C++03
157                      raw_storage_iterator&>           // purposefully not C++03
158{
159public:
160    explicit raw_storage_iterator(OutputIterator x);
161    raw_storage_iterator& operator*();
162    raw_storage_iterator& operator=(const T& element);
163    raw_storage_iterator& operator++();
164    raw_storage_iterator  operator++(int);
165};
166
167template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
168template <class T> void               return_temporary_buffer(T* p) noexcept;
169
170template <class T> T* addressof(T& r) noexcept;
171template <class T> T* addressof(const T&& r) noexcept = delete;
172
173template <class InputIterator, class ForwardIterator>
174ForwardIterator
175uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
176
177template <class InputIterator, class Size, class ForwardIterator>
178ForwardIterator
179uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
180
181template <class ForwardIterator, class T>
182void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
183
184template <class ForwardIterator, class Size, class T>
185ForwardIterator
186uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
187
188template <class T>
189void destroy_at(T* location);
190
191template <class ForwardIterator>
192 void destroy(ForwardIterator first, ForwardIterator last);
193
194template <class ForwardIterator, class Size>
195 ForwardIterator destroy_n(ForwardIterator first, Size n);
196
197template <class InputIterator, class ForwardIterator>
198 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
199
200template <class InputIterator, class Size, class ForwardIterator>
201 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
202
203template <class ForwardIterator>
204 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
205
206template <class ForwardIterator, class Size>
207 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
208
209template <class ForwardIterator>
210 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
211
212template <class ForwardIterator, class Size>
213 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
214
215template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
216
217template<class X>
218class auto_ptr                                  // deprecated in C++11, removed in C++17
219{
220public:
221    typedef X element_type;
222
223    explicit auto_ptr(X* p =0) throw();
224    auto_ptr(auto_ptr&) throw();
225    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
226    auto_ptr& operator=(auto_ptr&) throw();
227    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
228    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
229    ~auto_ptr() throw();
230
231    typename add_lvalue_reference<X>::type operator*() const throw();
232    X* operator->() const throw();
233    X* get() const throw();
234    X* release() throw();
235    void reset(X* p =0) throw();
236
237    auto_ptr(auto_ptr_ref<X>) throw();
238    template<class Y> operator auto_ptr_ref<Y>() throw();
239    template<class Y> operator auto_ptr<Y>() throw();
240};
241
242template <class T>
243struct default_delete
244{
245    constexpr default_delete() noexcept = default;
246    template <class U> default_delete(const default_delete<U>&) noexcept;
247
248    void operator()(T*) const noexcept;
249};
250
251template <class T>
252struct default_delete<T[]>
253{
254    constexpr default_delete() noexcept = default;
255    void operator()(T*) const noexcept;
256    template <class U> void operator()(U*) const = delete;
257};
258
259template <class T, class D = default_delete<T>>
260class unique_ptr
261{
262public:
263    typedef see below pointer;
264    typedef T element_type;
265    typedef D deleter_type;
266
267    // constructors
268    constexpr unique_ptr() noexcept;
269    explicit unique_ptr(pointer p) noexcept;
270    unique_ptr(pointer p, see below d1) noexcept;
271    unique_ptr(pointer p, see below d2) noexcept;
272    unique_ptr(unique_ptr&& u) noexcept;
273    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
274    template <class U, class E>
275        unique_ptr(unique_ptr<U, E>&& u) noexcept;
276    template <class U>
277        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
278
279    // destructor
280    ~unique_ptr();
281
282    // assignment
283    unique_ptr& operator=(unique_ptr&& u) noexcept;
284    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
285    unique_ptr& operator=(nullptr_t) noexcept;
286
287    // observers
288    typename add_lvalue_reference<T>::type operator*() const;
289    pointer operator->() const noexcept;
290    pointer get() const noexcept;
291    deleter_type& get_deleter() noexcept;
292    const deleter_type& get_deleter() const noexcept;
293    explicit operator bool() const noexcept;
294
295    // modifiers
296    pointer release() noexcept;
297    void reset(pointer p = pointer()) noexcept;
298    void swap(unique_ptr& u) noexcept;
299};
300
301template <class T, class D>
302class unique_ptr<T[], D>
303{
304public:
305    typedef implementation-defined pointer;
306    typedef T element_type;
307    typedef D deleter_type;
308
309    // constructors
310    constexpr unique_ptr() noexcept;
311    explicit unique_ptr(pointer p) noexcept;
312    unique_ptr(pointer p, see below d) noexcept;
313    unique_ptr(pointer p, see below d) noexcept;
314    unique_ptr(unique_ptr&& u) noexcept;
315    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
316
317    // destructor
318    ~unique_ptr();
319
320    // assignment
321    unique_ptr& operator=(unique_ptr&& u) noexcept;
322    unique_ptr& operator=(nullptr_t) noexcept;
323
324    // observers
325    T& operator[](size_t i) const;
326    pointer get() const noexcept;
327    deleter_type& get_deleter() noexcept;
328    const deleter_type& get_deleter() const noexcept;
329    explicit operator bool() const noexcept;
330
331    // modifiers
332    pointer release() noexcept;
333    void reset(pointer p = pointer()) noexcept;
334    void reset(nullptr_t) noexcept;
335    template <class U> void reset(U) = delete;
336    void swap(unique_ptr& u) noexcept;
337};
338
339template <class T, class D>
340    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
341
342template <class T1, class D1, class T2, class D2>
343    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
344template <class T1, class D1, class T2, class D2>
345    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
346template <class T1, class D1, class T2, class D2>
347    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
348template <class T1, class D1, class T2, class D2>
349    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
350template <class T1, class D1, class T2, class D2>
351    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
352template <class T1, class D1, class T2, class D2>
353    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
354
355template <class T, class D>
356    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
357template <class T, class D>
358    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
359template <class T, class D>
360    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
361template <class T, class D>
362    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
363
364template <class T, class D>
365    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
366template <class T, class D>
367    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
368template <class T, class D>
369    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
370template <class T, class D>
371    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
372template <class T, class D>
373    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
374template <class T, class D>
375    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
376template <class T, class D>
377    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
378template <class T, class D>
379    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
380
381class bad_weak_ptr
382    : public std::exception
383{
384    bad_weak_ptr() noexcept;
385};
386
387template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
388template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
389template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
390
391template<class E, class T, class Y, class D>
392    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
393
394template<class T>
395class shared_ptr
396{
397public:
398    typedef T element_type;
399    typedef weak_ptr<T> weak_type; // C++17
400
401    // constructors:
402    constexpr shared_ptr() noexcept;
403    template<class Y> explicit shared_ptr(Y* p);
404    template<class Y, class D> shared_ptr(Y* p, D d);
405    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
406    template <class D> shared_ptr(nullptr_t p, D d);
407    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
408    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
409    shared_ptr(const shared_ptr& r) noexcept;
410    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
411    shared_ptr(shared_ptr&& r) noexcept;
412    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
413    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
414    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
415    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
416    shared_ptr(nullptr_t) : shared_ptr() { }
417
418    // destructor:
419    ~shared_ptr();
420
421    // assignment:
422    shared_ptr& operator=(const shared_ptr& r) noexcept;
423    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
424    shared_ptr& operator=(shared_ptr&& r) noexcept;
425    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
426    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
427    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
428
429    // modifiers:
430    void swap(shared_ptr& r) noexcept;
431    void reset() noexcept;
432    template<class Y> void reset(Y* p);
433    template<class Y, class D> void reset(Y* p, D d);
434    template<class Y, class D, class A> void reset(Y* p, D d, A a);
435
436    // observers:
437    T* get() const noexcept;
438    T& operator*() const noexcept;
439    T* operator->() const noexcept;
440    long use_count() const noexcept;
441    bool unique() const noexcept;
442    explicit operator bool() const noexcept;
443    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
444    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
445};
446
447// shared_ptr comparisons:
448template<class T, class U>
449    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
450template<class T, class U>
451    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
452template<class T, class U>
453    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
454template<class T, class U>
455    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
456template<class T, class U>
457    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
458template<class T, class U>
459    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
460
461template <class T>
462    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
463template <class T>
464    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
465template <class T>
466    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
467template <class T>
468    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
469template <class T>
470    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
471template <class T>
472bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
473template <class T>
474    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
475template <class T>
476    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
477template <class T>
478    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
479template <class T>
480    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
481template <class T>
482    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
483template <class T>
484    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
485
486// shared_ptr specialized algorithms:
487template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
488
489// shared_ptr casts:
490template<class T, class U>
491    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
492template<class T, class U>
493    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
494template<class T, class U>
495    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
496
497// shared_ptr I/O:
498template<class E, class T, class Y>
499    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
500
501// shared_ptr get_deleter:
502template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
503
504template<class T, class... Args>
505    shared_ptr<T> make_shared(Args&&... args);
506template<class T, class A, class... Args>
507    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
508
509template<class T>
510class weak_ptr
511{
512public:
513    typedef T element_type;
514
515    // constructors
516    constexpr weak_ptr() noexcept;
517    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
518    weak_ptr(weak_ptr const& r) noexcept;
519    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
520    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
521    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
522
523    // destructor
524    ~weak_ptr();
525
526    // assignment
527    weak_ptr& operator=(weak_ptr const& r) noexcept;
528    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
529    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
530    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
531    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
532
533    // modifiers
534    void swap(weak_ptr& r) noexcept;
535    void reset() noexcept;
536
537    // observers
538    long use_count() const noexcept;
539    bool expired() const noexcept;
540    shared_ptr<T> lock() const noexcept;
541    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
542    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
543};
544
545// weak_ptr specialized algorithms:
546template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
547
548// class owner_less:
549template<class T> struct owner_less;
550
551template<class T>
552struct owner_less<shared_ptr<T>>
553    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
554{
555    typedef bool result_type;
556    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
557    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
558    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
559};
560
561template<class T>
562struct owner_less<weak_ptr<T>>
563    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
564{
565    typedef bool result_type;
566    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
567    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
568    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
569};
570
571template <>  // Added in C++14
572struct owner_less<void>
573{
574    template <class _Tp, class _Up>
575    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
576    template <class _Tp, class _Up>
577    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
578    template <class _Tp, class _Up>
579    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
580    template <class _Tp, class _Up>
581    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
582
583    typedef void is_transparent;
584};
585
586template<class T>
587class enable_shared_from_this
588{
589protected:
590    constexpr enable_shared_from_this() noexcept;
591    enable_shared_from_this(enable_shared_from_this const&) noexcept;
592    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
593    ~enable_shared_from_this();
594public:
595    shared_ptr<T> shared_from_this();
596    shared_ptr<T const> shared_from_this() const;
597};
598
599template<class T>
600    bool atomic_is_lock_free(const shared_ptr<T>* p);
601template<class T>
602    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
603template<class T>
604    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
605template<class T>
606    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
607template<class T>
608    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
609template<class T>
610    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
611template<class T>
612    shared_ptr<T>
613    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
614template<class T>
615    bool
616    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
617template<class T>
618    bool
619    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
620template<class T>
621    bool
622    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
623                                          shared_ptr<T> w, memory_order success,
624                                          memory_order failure);
625template<class T>
626    bool
627    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
628                                            shared_ptr<T> w, memory_order success,
629                                            memory_order failure);
630// Hash support
631template <class T> struct hash;
632template <class T, class D> struct hash<unique_ptr<T, D> >;
633template <class T> struct hash<shared_ptr<T> >;
634
635template <class T, class Alloc>
636  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
637
638// Pointer safety
639enum class pointer_safety { relaxed, preferred, strict };
640void declare_reachable(void *p);
641template <class T> T *undeclare_reachable(T *p);
642void declare_no_pointers(char *p, size_t n);
643void undeclare_no_pointers(char *p, size_t n);
644pointer_safety get_pointer_safety() noexcept;
645
646void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
647
648}  // std
649
650*/
651
652#include <__config>
653#include <type_traits>
654#include <typeinfo>
655#include <cstddef>
656#include <cstdint>
657#include <new>
658#include <utility>
659#include <limits>
660#include <iterator>
661#include <__functional_base>
662#include <iosfwd>
663#include <tuple>
664#include <stdexcept>
665#include <cstring>
666#include <cassert>
667#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
668#  include <atomic>
669#endif
670#include <version>
671
672#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
673#pragma GCC system_header
674#endif
675
676_LIBCPP_PUSH_MACROS
677#include <__undef_macros>
678
679
680_LIBCPP_BEGIN_NAMESPACE_STD
681
682template <class _ValueType>
683inline _LIBCPP_INLINE_VISIBILITY
684_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
685#if !defined(_LIBCPP_HAS_NO_THREADS) && \
686    defined(__ATOMIC_RELAXED) &&        \
687    (__has_builtin(__atomic_load_n) || _GNUC_VER >= 407)
688    return __atomic_load_n(__value, __ATOMIC_RELAXED);
689#else
690    return *__value;
691#endif
692}
693
694template <class _ValueType>
695inline _LIBCPP_INLINE_VISIBILITY
696_ValueType __libcpp_acquire_load(_ValueType const* __value) {
697#if !defined(_LIBCPP_HAS_NO_THREADS) && \
698    defined(__ATOMIC_ACQUIRE) &&        \
699    (__has_builtin(__atomic_load_n) || _GNUC_VER >= 407)
700    return __atomic_load_n(__value, __ATOMIC_ACQUIRE);
701#else
702    return *__value;
703#endif
704}
705
706// addressof moved to <type_traits>
707
708template <class _Tp> class allocator;
709
710template <>
711class _LIBCPP_TEMPLATE_VIS allocator<void>
712{
713public:
714    typedef void*             pointer;
715    typedef const void*       const_pointer;
716    typedef void              value_type;
717
718    template <class _Up> struct rebind {typedef allocator<_Up> other;};
719};
720
721template <>
722class _LIBCPP_TEMPLATE_VIS allocator<const void>
723{
724public:
725    typedef const void*       pointer;
726    typedef const void*       const_pointer;
727    typedef const void        value_type;
728
729    template <class _Up> struct rebind {typedef allocator<_Up> other;};
730};
731
732// pointer_traits
733
734template <class _Tp, class = void>
735struct __has_element_type : false_type {};
736
737template <class _Tp>
738struct __has_element_type<_Tp,
739              typename __void_t<typename _Tp::element_type>::type> : true_type {};
740
741template <class _Ptr, bool = __has_element_type<_Ptr>::value>
742struct __pointer_traits_element_type;
743
744template <class _Ptr>
745struct __pointer_traits_element_type<_Ptr, true>
746{
747    typedef typename _Ptr::element_type type;
748};
749
750#ifndef _LIBCPP_HAS_NO_VARIADICS
751
752template <template <class, class...> class _Sp, class _Tp, class ..._Args>
753struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
754{
755    typedef typename _Sp<_Tp, _Args...>::element_type type;
756};
757
758template <template <class, class...> class _Sp, class _Tp, class ..._Args>
759struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
760{
761    typedef _Tp type;
762};
763
764#else  // _LIBCPP_HAS_NO_VARIADICS
765
766template <template <class> class _Sp, class _Tp>
767struct __pointer_traits_element_type<_Sp<_Tp>, true>
768{
769    typedef typename _Sp<_Tp>::element_type type;
770};
771
772template <template <class> class _Sp, class _Tp>
773struct __pointer_traits_element_type<_Sp<_Tp>, false>
774{
775    typedef _Tp type;
776};
777
778template <template <class, class> class _Sp, class _Tp, class _A0>
779struct __pointer_traits_element_type<_Sp<_Tp, _A0>, true>
780{
781    typedef typename _Sp<_Tp, _A0>::element_type type;
782};
783
784template <template <class, class> class _Sp, class _Tp, class _A0>
785struct __pointer_traits_element_type<_Sp<_Tp, _A0>, false>
786{
787    typedef _Tp type;
788};
789
790template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
791struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, true>
792{
793    typedef typename _Sp<_Tp, _A0, _A1>::element_type type;
794};
795
796template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
797struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, false>
798{
799    typedef _Tp type;
800};
801
802template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
803                                                           class _A1, class _A2>
804struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, true>
805{
806    typedef typename _Sp<_Tp, _A0, _A1, _A2>::element_type type;
807};
808
809template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
810                                                           class _A1, class _A2>
811struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, false>
812{
813    typedef _Tp type;
814};
815
816#endif  // _LIBCPP_HAS_NO_VARIADICS
817
818template <class _Tp, class = void>
819struct __has_difference_type : false_type {};
820
821template <class _Tp>
822struct __has_difference_type<_Tp,
823            typename __void_t<typename _Tp::difference_type>::type> : true_type {};
824
825template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
826struct __pointer_traits_difference_type
827{
828    typedef ptrdiff_t type;
829};
830
831template <class _Ptr>
832struct __pointer_traits_difference_type<_Ptr, true>
833{
834    typedef typename _Ptr::difference_type type;
835};
836
837template <class _Tp, class _Up>
838struct __has_rebind
839{
840private:
841    struct __two {char __lx; char __lxx;};
842    template <class _Xp> static __two __test(...);
843    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
844public:
845    static const bool value = sizeof(__test<_Tp>(0)) == 1;
846};
847
848template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
849struct __pointer_traits_rebind
850{
851#ifndef _LIBCPP_CXX03_LANG
852    typedef typename _Tp::template rebind<_Up> type;
853#else
854    typedef typename _Tp::template rebind<_Up>::other type;
855#endif
856};
857
858#ifndef _LIBCPP_HAS_NO_VARIADICS
859
860template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
861struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
862{
863#ifndef _LIBCPP_CXX03_LANG
864    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
865#else
866    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
867#endif
868};
869
870template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
871struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
872{
873    typedef _Sp<_Up, _Args...> type;
874};
875
876#else  // _LIBCPP_HAS_NO_VARIADICS
877
878template <template <class> class _Sp, class _Tp, class _Up>
879struct __pointer_traits_rebind<_Sp<_Tp>, _Up, true>
880{
881#ifndef _LIBCPP_CXX03_LANG
882    typedef typename _Sp<_Tp>::template rebind<_Up> type;
883#else
884    typedef typename _Sp<_Tp>::template rebind<_Up>::other type;
885#endif
886};
887
888template <template <class> class _Sp, class _Tp, class _Up>
889struct __pointer_traits_rebind<_Sp<_Tp>, _Up, false>
890{
891    typedef _Sp<_Up> type;
892};
893
894template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
895struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, true>
896{
897#ifndef _LIBCPP_CXX03_LANG
898    typedef typename _Sp<_Tp, _A0>::template rebind<_Up> type;
899#else
900    typedef typename _Sp<_Tp, _A0>::template rebind<_Up>::other type;
901#endif
902};
903
904template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
905struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, false>
906{
907    typedef _Sp<_Up, _A0> type;
908};
909
910template <template <class, class, class> class _Sp, class _Tp, class _A0,
911                                         class _A1, class _Up>
912struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, true>
913{
914#ifndef _LIBCPP_CXX03_LANG
915    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up> type;
916#else
917    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up>::other type;
918#endif
919};
920
921template <template <class, class, class> class _Sp, class _Tp, class _A0,
922                                         class _A1, class _Up>
923struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, false>
924{
925    typedef _Sp<_Up, _A0, _A1> type;
926};
927
928template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
929                                                class _A1, class _A2, class _Up>
930struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, true>
931{
932#ifndef _LIBCPP_CXX03_LANG
933    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up> type;
934#else
935    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
936#endif
937};
938
939template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
940                                                class _A1, class _A2, class _Up>
941struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, false>
942{
943    typedef _Sp<_Up, _A0, _A1, _A2> type;
944};
945
946#endif  // _LIBCPP_HAS_NO_VARIADICS
947
948template <class _Ptr>
949struct _LIBCPP_TEMPLATE_VIS pointer_traits
950{
951    typedef _Ptr                                                     pointer;
952    typedef typename __pointer_traits_element_type<pointer>::type    element_type;
953    typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
954
955#ifndef _LIBCPP_CXX03_LANG
956    template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
957#else
958    template <class _Up> struct rebind
959        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
960#endif  // _LIBCPP_CXX03_LANG
961
962private:
963    struct __nat {};
964public:
965    _LIBCPP_INLINE_VISIBILITY
966    static pointer pointer_to(typename conditional<is_void<element_type>::value,
967                                           __nat, element_type>::type& __r)
968        {return pointer::pointer_to(__r);}
969};
970
971template <class _Tp>
972struct _LIBCPP_TEMPLATE_VIS pointer_traits<_Tp*>
973{
974    typedef _Tp*      pointer;
975    typedef _Tp       element_type;
976    typedef ptrdiff_t difference_type;
977
978#ifndef _LIBCPP_CXX03_LANG
979    template <class _Up> using rebind = _Up*;
980#else
981    template <class _Up> struct rebind {typedef _Up* other;};
982#endif
983
984private:
985    struct __nat {};
986public:
987    _LIBCPP_INLINE_VISIBILITY
988    static pointer pointer_to(typename conditional<is_void<element_type>::value,
989                                      __nat, element_type>::type& __r) _NOEXCEPT
990        {return _VSTD::addressof(__r);}
991};
992
993template <class _From, class _To>
994struct __rebind_pointer {
995#ifndef _LIBCPP_CXX03_LANG
996    typedef typename pointer_traits<_From>::template rebind<_To>        type;
997#else
998    typedef typename pointer_traits<_From>::template rebind<_To>::other type;
999#endif
1000};
1001
1002// allocator_traits
1003
1004template <class _Tp, class = void>
1005struct __has_pointer_type : false_type {};
1006
1007template <class _Tp>
1008struct __has_pointer_type<_Tp,
1009          typename __void_t<typename _Tp::pointer>::type> : true_type {};
1010
1011namespace __pointer_type_imp
1012{
1013
1014template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
1015struct __pointer_type
1016{
1017    typedef typename _Dp::pointer type;
1018};
1019
1020template <class _Tp, class _Dp>
1021struct __pointer_type<_Tp, _Dp, false>
1022{
1023    typedef _Tp* type;
1024};
1025
1026}  // __pointer_type_imp
1027
1028template <class _Tp, class _Dp>
1029struct __pointer_type
1030{
1031    typedef typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
1032};
1033
1034template <class _Tp, class = void>
1035struct __has_const_pointer : false_type {};
1036
1037template <class _Tp>
1038struct __has_const_pointer<_Tp,
1039            typename __void_t<typename _Tp::const_pointer>::type> : true_type {};
1040
1041template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
1042struct __const_pointer
1043{
1044    typedef typename _Alloc::const_pointer type;
1045};
1046
1047template <class _Tp, class _Ptr, class _Alloc>
1048struct __const_pointer<_Tp, _Ptr, _Alloc, false>
1049{
1050#ifndef _LIBCPP_CXX03_LANG
1051    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
1052#else
1053    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
1054#endif
1055};
1056
1057template <class _Tp, class = void>
1058struct __has_void_pointer : false_type {};
1059
1060template <class _Tp>
1061struct __has_void_pointer<_Tp,
1062               typename __void_t<typename _Tp::void_pointer>::type> : true_type {};
1063
1064template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
1065struct __void_pointer
1066{
1067    typedef typename _Alloc::void_pointer type;
1068};
1069
1070template <class _Ptr, class _Alloc>
1071struct __void_pointer<_Ptr, _Alloc, false>
1072{
1073#ifndef _LIBCPP_CXX03_LANG
1074    typedef typename pointer_traits<_Ptr>::template rebind<void> type;
1075#else
1076    typedef typename pointer_traits<_Ptr>::template rebind<void>::other type;
1077#endif
1078};
1079
1080template <class _Tp, class = void>
1081struct __has_const_void_pointer : false_type {};
1082
1083template <class _Tp>
1084struct __has_const_void_pointer<_Tp,
1085            typename __void_t<typename _Tp::const_void_pointer>::type> : true_type {};
1086
1087template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
1088struct __const_void_pointer
1089{
1090    typedef typename _Alloc::const_void_pointer type;
1091};
1092
1093template <class _Ptr, class _Alloc>
1094struct __const_void_pointer<_Ptr, _Alloc, false>
1095{
1096#ifndef _LIBCPP_CXX03_LANG
1097    typedef typename pointer_traits<_Ptr>::template rebind<const void> type;
1098#else
1099    typedef typename pointer_traits<_Ptr>::template rebind<const void>::other type;
1100#endif
1101};
1102
1103template <class _Tp>
1104inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1105_Tp*
1106__to_raw_pointer(_Tp* __p) _NOEXCEPT
1107{
1108    return __p;
1109}
1110
1111#if _LIBCPP_STD_VER <= 17
1112template <class _Pointer>
1113inline _LIBCPP_INLINE_VISIBILITY
1114typename pointer_traits<_Pointer>::element_type*
1115__to_raw_pointer(_Pointer __p) _NOEXCEPT
1116{
1117    return _VSTD::__to_raw_pointer(__p.operator->());
1118}
1119#else
1120template <class _Pointer>
1121inline _LIBCPP_INLINE_VISIBILITY
1122auto
1123__to_raw_pointer(const _Pointer& __p) _NOEXCEPT
1124-> decltype(pointer_traits<_Pointer>::to_address(__p))
1125{
1126    return pointer_traits<_Pointer>::to_address(__p);
1127}
1128
1129template <class _Pointer, class... _None>
1130inline _LIBCPP_INLINE_VISIBILITY
1131auto
1132__to_raw_pointer(const _Pointer& __p, _None...) _NOEXCEPT
1133{
1134    return _VSTD::__to_raw_pointer(__p.operator->());
1135}
1136
1137template <class _Tp>
1138inline _LIBCPP_INLINE_VISIBILITY constexpr
1139_Tp*
1140to_address(_Tp* __p) _NOEXCEPT
1141{
1142    static_assert(!is_function_v<_Tp>, "_Tp is a function type");
1143    return __p;
1144}
1145
1146template <class _Pointer>
1147inline _LIBCPP_INLINE_VISIBILITY
1148auto
1149to_address(const _Pointer& __p) _NOEXCEPT
1150{
1151    return _VSTD::__to_raw_pointer(__p);
1152}
1153#endif
1154
1155template <class _Tp, class = void>
1156struct __has_size_type : false_type {};
1157
1158template <class _Tp>
1159struct __has_size_type<_Tp,
1160               typename __void_t<typename _Tp::size_type>::type> : true_type {};
1161
1162template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
1163struct __size_type
1164{
1165    typedef typename make_unsigned<_DiffType>::type type;
1166};
1167
1168template <class _Alloc, class _DiffType>
1169struct __size_type<_Alloc, _DiffType, true>
1170{
1171    typedef typename _Alloc::size_type type;
1172};
1173
1174template <class _Tp, class = void>
1175struct __has_propagate_on_container_copy_assignment : false_type {};
1176
1177template <class _Tp>
1178struct __has_propagate_on_container_copy_assignment<_Tp,
1179    typename __void_t<typename _Tp::propagate_on_container_copy_assignment>::type>
1180        : true_type {};
1181
1182template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
1183struct __propagate_on_container_copy_assignment
1184{
1185    typedef false_type type;
1186};
1187
1188template <class _Alloc>
1189struct __propagate_on_container_copy_assignment<_Alloc, true>
1190{
1191    typedef typename _Alloc::propagate_on_container_copy_assignment type;
1192};
1193
1194template <class _Tp, class = void>
1195struct __has_propagate_on_container_move_assignment : false_type {};
1196
1197template <class _Tp>
1198struct __has_propagate_on_container_move_assignment<_Tp,
1199           typename __void_t<typename _Tp::propagate_on_container_move_assignment>::type>
1200               : true_type {};
1201
1202template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
1203struct __propagate_on_container_move_assignment
1204{
1205    typedef false_type type;
1206};
1207
1208template <class _Alloc>
1209struct __propagate_on_container_move_assignment<_Alloc, true>
1210{
1211    typedef typename _Alloc::propagate_on_container_move_assignment type;
1212};
1213
1214template <class _Tp, class = void>
1215struct __has_propagate_on_container_swap : false_type {};
1216
1217template <class _Tp>
1218struct __has_propagate_on_container_swap<_Tp,
1219           typename __void_t<typename _Tp::propagate_on_container_swap>::type>
1220               : true_type {};
1221
1222template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
1223struct __propagate_on_container_swap
1224{
1225    typedef false_type type;
1226};
1227
1228template <class _Alloc>
1229struct __propagate_on_container_swap<_Alloc, true>
1230{
1231    typedef typename _Alloc::propagate_on_container_swap type;
1232};
1233
1234template <class _Tp, class = void>
1235struct __has_is_always_equal : false_type {};
1236
1237template <class _Tp>
1238struct __has_is_always_equal<_Tp,
1239           typename __void_t<typename _Tp::is_always_equal>::type>
1240               : true_type {};
1241
1242template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
1243struct __is_always_equal
1244{
1245    typedef typename _VSTD::is_empty<_Alloc>::type type;
1246};
1247
1248template <class _Alloc>
1249struct __is_always_equal<_Alloc, true>
1250{
1251    typedef typename _Alloc::is_always_equal type;
1252};
1253
1254template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
1255struct __has_rebind_other
1256{
1257private:
1258    struct __two {char __lx; char __lxx;};
1259    template <class _Xp> static __two __test(...);
1260    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
1261public:
1262    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1263};
1264
1265template <class _Tp, class _Up>
1266struct __has_rebind_other<_Tp, _Up, false>
1267{
1268    static const bool value = false;
1269};
1270
1271template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
1272struct __allocator_traits_rebind
1273{
1274    typedef typename _Tp::template rebind<_Up>::other type;
1275};
1276
1277#ifndef _LIBCPP_HAS_NO_VARIADICS
1278
1279template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1280struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
1281{
1282    typedef typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
1283};
1284
1285template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1286struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
1287{
1288    typedef _Alloc<_Up, _Args...> type;
1289};
1290
1291#else  // _LIBCPP_HAS_NO_VARIADICS
1292
1293template <template <class> class _Alloc, class _Tp, class _Up>
1294struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, true>
1295{
1296    typedef typename _Alloc<_Tp>::template rebind<_Up>::other type;
1297};
1298
1299template <template <class> class _Alloc, class _Tp, class _Up>
1300struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, false>
1301{
1302    typedef _Alloc<_Up> type;
1303};
1304
1305template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1306struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, true>
1307{
1308    typedef typename _Alloc<_Tp, _A0>::template rebind<_Up>::other type;
1309};
1310
1311template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1312struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, false>
1313{
1314    typedef _Alloc<_Up, _A0> type;
1315};
1316
1317template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1318                                         class _A1, class _Up>
1319struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, true>
1320{
1321    typedef typename _Alloc<_Tp, _A0, _A1>::template rebind<_Up>::other type;
1322};
1323
1324template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1325                                         class _A1, class _Up>
1326struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, false>
1327{
1328    typedef _Alloc<_Up, _A0, _A1> type;
1329};
1330
1331template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1332                                                class _A1, class _A2, class _Up>
1333struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, true>
1334{
1335    typedef typename _Alloc<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
1336};
1337
1338template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1339                                                class _A1, class _A2, class _Up>
1340struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, false>
1341{
1342    typedef _Alloc<_Up, _A0, _A1, _A2> type;
1343};
1344
1345#endif  // _LIBCPP_HAS_NO_VARIADICS
1346
1347#ifndef _LIBCPP_CXX03_LANG
1348
1349template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1350auto
1351__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1352    -> decltype((void)__a.allocate(__sz, __p), true_type());
1353
1354template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1355auto
1356__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1357    -> false_type;
1358
1359template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1360struct __has_allocate_hint
1361    : integral_constant<bool,
1362        is_same<
1363            decltype(_VSTD::__has_allocate_hint_test(declval<_Alloc>(),
1364                                          declval<_SizeType>(),
1365                                          declval<_ConstVoidPtr>())),
1366            true_type>::value>
1367{
1368};
1369
1370#else  // _LIBCPP_CXX03_LANG
1371
1372template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1373struct __has_allocate_hint
1374    : true_type
1375{
1376};
1377
1378#endif  // _LIBCPP_CXX03_LANG
1379
1380#if !defined(_LIBCPP_CXX03_LANG)
1381
1382template <class _Alloc, class _Tp, class ..._Args>
1383decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Tp*>(),
1384                                           _VSTD::declval<_Args>()...),
1385                                           true_type())
1386__has_construct_test(_Alloc&& __a, _Tp* __p, _Args&& ...__args);
1387
1388template <class _Alloc, class _Pointer, class ..._Args>
1389false_type
1390__has_construct_test(const _Alloc& __a, _Pointer&& __p, _Args&& ...__args);
1391
1392template <class _Alloc, class _Pointer, class ..._Args>
1393struct __has_construct
1394    : integral_constant<bool,
1395        is_same<
1396            decltype(_VSTD::__has_construct_test(declval<_Alloc>(),
1397                                          declval<_Pointer>(),
1398                                          declval<_Args>()...)),
1399            true_type>::value>
1400{
1401};
1402
1403template <class _Alloc, class _Pointer>
1404auto
1405__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
1406    -> decltype(__a.destroy(__p), true_type());
1407
1408template <class _Alloc, class _Pointer>
1409auto
1410__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
1411    -> false_type;
1412
1413template <class _Alloc, class _Pointer>
1414struct __has_destroy
1415    : integral_constant<bool,
1416        is_same<
1417            decltype(_VSTD::__has_destroy_test(declval<_Alloc>(),
1418                                        declval<_Pointer>())),
1419            true_type>::value>
1420{
1421};
1422
1423template <class _Alloc>
1424auto
1425__has_max_size_test(_Alloc&& __a)
1426    -> decltype(__a.max_size(), true_type());
1427
1428template <class _Alloc>
1429auto
1430__has_max_size_test(const volatile _Alloc& __a)
1431    -> false_type;
1432
1433template <class _Alloc>
1434struct __has_max_size
1435    : integral_constant<bool,
1436        is_same<
1437            decltype(_VSTD::__has_max_size_test(declval<_Alloc&>())),
1438            true_type>::value>
1439{
1440};
1441
1442template <class _Alloc>
1443auto
1444__has_select_on_container_copy_construction_test(_Alloc&& __a)
1445    -> decltype(__a.select_on_container_copy_construction(), true_type());
1446
1447template <class _Alloc>
1448auto
1449__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
1450    -> false_type;
1451
1452template <class _Alloc>
1453struct __has_select_on_container_copy_construction
1454    : integral_constant<bool,
1455        is_same<
1456            decltype(_VSTD::__has_select_on_container_copy_construction_test(declval<_Alloc&>())),
1457            true_type>::value>
1458{
1459};
1460
1461#else  // _LIBCPP_CXX03_LANG
1462
1463#ifndef _LIBCPP_HAS_NO_VARIADICS
1464
1465template <class _Alloc, class _Pointer, class ..._Args>
1466struct __has_construct
1467    : false_type
1468{
1469};
1470
1471#else  // _LIBCPP_HAS_NO_VARIADICS
1472
1473template <class _Alloc, class _Pointer, class _Args>
1474struct __has_construct
1475    : false_type
1476{
1477};
1478
1479#endif  // _LIBCPP_HAS_NO_VARIADICS
1480
1481template <class _Alloc, class _Pointer>
1482struct __has_destroy
1483    : false_type
1484{
1485};
1486
1487template <class _Alloc>
1488struct __has_max_size
1489    : true_type
1490{
1491};
1492
1493template <class _Alloc>
1494struct __has_select_on_container_copy_construction
1495    : false_type
1496{
1497};
1498
1499#endif  // _LIBCPP_CXX03_LANG
1500
1501template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
1502struct __alloc_traits_difference_type
1503{
1504    typedef typename pointer_traits<_Ptr>::difference_type type;
1505};
1506
1507template <class _Alloc, class _Ptr>
1508struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
1509{
1510    typedef typename _Alloc::difference_type type;
1511};
1512
1513template <class _Alloc>
1514struct _LIBCPP_TEMPLATE_VIS allocator_traits
1515{
1516    typedef _Alloc                              allocator_type;
1517    typedef typename allocator_type::value_type value_type;
1518
1519    typedef typename __pointer_type<value_type, allocator_type>::type pointer;
1520    typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
1521    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
1522    typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;
1523
1524    typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
1525    typedef typename __size_type<allocator_type, difference_type>::type size_type;
1526
1527    typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
1528                     propagate_on_container_copy_assignment;
1529    typedef typename __propagate_on_container_move_assignment<allocator_type>::type
1530                     propagate_on_container_move_assignment;
1531    typedef typename __propagate_on_container_swap<allocator_type>::type
1532                     propagate_on_container_swap;
1533    typedef typename __is_always_equal<allocator_type>::type
1534                     is_always_equal;
1535
1536#ifndef _LIBCPP_CXX03_LANG
1537    template <class _Tp> using rebind_alloc =
1538                  typename __allocator_traits_rebind<allocator_type, _Tp>::type;
1539    template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp>>;
1540#else  // _LIBCPP_CXX03_LANG
1541    template <class _Tp> struct rebind_alloc
1542        {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
1543    template <class _Tp> struct rebind_traits
1544        {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
1545#endif  // _LIBCPP_CXX03_LANG
1546
1547    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1548    static pointer allocate(allocator_type& __a, size_type __n)
1549        {return __a.allocate(__n);}
1550    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1551    static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
1552        {return __allocate(__a, __n, __hint,
1553            __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}
1554
1555    _LIBCPP_INLINE_VISIBILITY
1556    static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
1557        {__a.deallocate(__p, __n);}
1558
1559#ifndef _LIBCPP_HAS_NO_VARIADICS
1560    template <class _Tp, class... _Args>
1561        _LIBCPP_INLINE_VISIBILITY
1562        static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
1563            {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
1564                         __a, __p, _VSTD::forward<_Args>(__args)...);}
1565#else  // _LIBCPP_HAS_NO_VARIADICS
1566    template <class _Tp>
1567        _LIBCPP_INLINE_VISIBILITY
1568        static void construct(allocator_type&, _Tp* __p)
1569            {
1570                ::new ((void*)__p) _Tp();
1571            }
1572    template <class _Tp, class _A0>
1573        _LIBCPP_INLINE_VISIBILITY
1574        static void construct(allocator_type&, _Tp* __p, const _A0& __a0)
1575            {
1576                ::new ((void*)__p) _Tp(__a0);
1577            }
1578    template <class _Tp, class _A0, class _A1>
1579        _LIBCPP_INLINE_VISIBILITY
1580        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
1581                              const _A1& __a1)
1582            {
1583                ::new ((void*)__p) _Tp(__a0, __a1);
1584            }
1585    template <class _Tp, class _A0, class _A1, class _A2>
1586        _LIBCPP_INLINE_VISIBILITY
1587        static void construct(allocator_type&, _Tp* __p, const _A0& __a0,
1588                              const _A1& __a1, const _A2& __a2)
1589            {
1590                ::new ((void*)__p) _Tp(__a0, __a1, __a2);
1591            }
1592#endif  // _LIBCPP_HAS_NO_VARIADICS
1593
1594    template <class _Tp>
1595        _LIBCPP_INLINE_VISIBILITY
1596        static void destroy(allocator_type& __a, _Tp* __p)
1597            {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}
1598
1599    _LIBCPP_INLINE_VISIBILITY
1600    static size_type max_size(const allocator_type& __a) _NOEXCEPT
1601        {return __max_size(__has_max_size<const allocator_type>(), __a);}
1602
1603    _LIBCPP_INLINE_VISIBILITY
1604    static allocator_type
1605        select_on_container_copy_construction(const allocator_type& __a)
1606            {return __select_on_container_copy_construction(
1607                __has_select_on_container_copy_construction<const allocator_type>(),
1608                __a);}
1609
1610    template <class _Ptr>
1611        _LIBCPP_INLINE_VISIBILITY
1612        static
1613        void
1614        __construct_forward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
1615        {
1616            for (; __begin1 != __end1; ++__begin1, ++__begin2)
1617                construct(__a, _VSTD::__to_raw_pointer(__begin2), _VSTD::move_if_noexcept(*__begin1));
1618        }
1619
1620    template <class _Tp>
1621        _LIBCPP_INLINE_VISIBILITY
1622        static
1623        typename enable_if
1624        <
1625            (is_same<allocator_type, allocator<_Tp> >::value
1626                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1627             is_trivially_move_constructible<_Tp>::value,
1628            void
1629        >::type
1630        __construct_forward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
1631        {
1632            ptrdiff_t _Np = __end1 - __begin1;
1633            if (_Np > 0)
1634            {
1635                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
1636                __begin2 += _Np;
1637            }
1638        }
1639
1640    template <class _Iter, class _Ptr>
1641        _LIBCPP_INLINE_VISIBILITY
1642        static
1643        void
1644        __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
1645        {
1646            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1647                construct(__a, _VSTD::__to_raw_pointer(__begin2), *__begin1);
1648        }
1649
1650    template <class _Tp>
1651        _LIBCPP_INLINE_VISIBILITY
1652        static
1653        typename enable_if
1654        <
1655            (is_same<allocator_type, allocator<_Tp> >::value
1656                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1657             is_trivially_move_constructible<_Tp>::value,
1658            void
1659        >::type
1660        __construct_range_forward(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
1661        {
1662            typedef typename remove_const<_Tp>::type _Vp;
1663            ptrdiff_t _Np = __end1 - __begin1;
1664            if (_Np > 0)
1665            {
1666                _VSTD::memcpy(const_cast<_Vp*>(__begin2), __begin1, _Np * sizeof(_Tp));
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_same<allocator_type, allocator<_Tp> >::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#endif  // _LIBCPP_HAS_NO_VARIADICS
1725
1726    template <class _Tp>
1727        _LIBCPP_INLINE_VISIBILITY
1728        static void __destroy(true_type, allocator_type& __a, _Tp* __p)
1729            {__a.destroy(__p);}
1730    template <class _Tp>
1731        _LIBCPP_INLINE_VISIBILITY
1732        static void __destroy(false_type, allocator_type&, _Tp* __p)
1733            {
1734                __p->~_Tp();
1735            }
1736
1737    _LIBCPP_INLINE_VISIBILITY
1738    static size_type __max_size(true_type, const allocator_type& __a) _NOEXCEPT
1739            {return __a.max_size();}
1740    _LIBCPP_INLINE_VISIBILITY
1741    static size_type __max_size(false_type, const allocator_type&) _NOEXCEPT
1742            {return numeric_limits<size_type>::max() / sizeof(value_type);}
1743
1744    _LIBCPP_INLINE_VISIBILITY
1745    static allocator_type
1746        __select_on_container_copy_construction(true_type, const allocator_type& __a)
1747            {return __a.select_on_container_copy_construction();}
1748    _LIBCPP_INLINE_VISIBILITY
1749    static allocator_type
1750        __select_on_container_copy_construction(false_type, const allocator_type& __a)
1751            {return __a;}
1752};
1753
1754template <class _Traits, class _Tp>
1755struct __rebind_alloc_helper
1756{
1757#ifndef _LIBCPP_CXX03_LANG
1758    typedef typename _Traits::template rebind_alloc<_Tp>        type;
1759#else
1760    typedef typename _Traits::template rebind_alloc<_Tp>::other type;
1761#endif
1762};
1763
1764// allocator
1765
1766template <class _Tp>
1767class _LIBCPP_TEMPLATE_VIS allocator
1768{
1769public:
1770    typedef size_t            size_type;
1771    typedef ptrdiff_t         difference_type;
1772    typedef _Tp*              pointer;
1773    typedef const _Tp*        const_pointer;
1774    typedef _Tp&              reference;
1775    typedef const _Tp&        const_reference;
1776    typedef _Tp               value_type;
1777
1778    typedef true_type propagate_on_container_move_assignment;
1779    typedef true_type is_always_equal;
1780
1781    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1782
1783    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1784    allocator() _NOEXCEPT {}
1785
1786    template <class _Up>
1787    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1788    allocator(const allocator<_Up>&) _NOEXCEPT {}
1789
1790    _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
1791        {return _VSTD::addressof(__x);}
1792    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1793        {return _VSTD::addressof(__x);}
1794    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY
1795    pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1796        {
1797        if (__n > max_size())
1798            __throw_length_error("allocator<T>::allocate(size_t n)"
1799                                 " 'n' exceeds maximum supported size");
1800        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), __alignof(_Tp)));
1801        }
1802    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
1803        {_VSTD::__libcpp_deallocate((void*)__p, __alignof(_Tp));}
1804    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1805        {return size_type(~0) / sizeof(_Tp);}
1806#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1807    template <class _Up, class... _Args>
1808        _LIBCPP_INLINE_VISIBILITY
1809        void
1810        construct(_Up* __p, _Args&&... __args)
1811        {
1812            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1813        }
1814#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1815        _LIBCPP_INLINE_VISIBILITY
1816        void
1817        construct(pointer __p)
1818        {
1819            ::new((void*)__p) _Tp();
1820        }
1821# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1822
1823    template <class _A0>
1824        _LIBCPP_INLINE_VISIBILITY
1825        void
1826        construct(pointer __p, _A0& __a0)
1827        {
1828            ::new((void*)__p) _Tp(__a0);
1829        }
1830    template <class _A0>
1831        _LIBCPP_INLINE_VISIBILITY
1832        void
1833        construct(pointer __p, const _A0& __a0)
1834        {
1835            ::new((void*)__p) _Tp(__a0);
1836        }
1837# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1838    template <class _A0, class _A1>
1839        _LIBCPP_INLINE_VISIBILITY
1840        void
1841        construct(pointer __p, _A0& __a0, _A1& __a1)
1842        {
1843            ::new((void*)__p) _Tp(__a0, __a1);
1844        }
1845    template <class _A0, class _A1>
1846        _LIBCPP_INLINE_VISIBILITY
1847        void
1848        construct(pointer __p, const _A0& __a0, _A1& __a1)
1849        {
1850            ::new((void*)__p) _Tp(__a0, __a1);
1851        }
1852    template <class _A0, class _A1>
1853        _LIBCPP_INLINE_VISIBILITY
1854        void
1855        construct(pointer __p, _A0& __a0, const _A1& __a1)
1856        {
1857            ::new((void*)__p) _Tp(__a0, __a1);
1858        }
1859    template <class _A0, class _A1>
1860        _LIBCPP_INLINE_VISIBILITY
1861        void
1862        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1863        {
1864            ::new((void*)__p) _Tp(__a0, __a1);
1865        }
1866#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1867    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1868};
1869
1870template <class _Tp>
1871class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
1872{
1873public:
1874    typedef size_t            size_type;
1875    typedef ptrdiff_t         difference_type;
1876    typedef const _Tp*        pointer;
1877    typedef const _Tp*        const_pointer;
1878    typedef const _Tp&        reference;
1879    typedef const _Tp&        const_reference;
1880    typedef const _Tp         value_type;
1881
1882    typedef true_type propagate_on_container_move_assignment;
1883    typedef true_type is_always_equal;
1884
1885    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1886
1887    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1888    allocator() _NOEXCEPT {}
1889
1890    template <class _Up>
1891    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1892    allocator(const allocator<_Up>&) _NOEXCEPT {}
1893
1894    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1895        {return _VSTD::addressof(__x);}
1896    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1897    {
1898        if (__n > max_size())
1899            __throw_length_error("allocator<const T>::allocate(size_t n)"
1900                                 " 'n' exceeds maximum supported size");
1901        return static_cast<pointer>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), __alignof(_Tp)));
1902    }
1903    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
1904        {_VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __alignof(_Tp));}
1905    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1906        {return size_type(~0) / sizeof(_Tp);}
1907#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1908    template <class _Up, class... _Args>
1909        _LIBCPP_INLINE_VISIBILITY
1910        void
1911        construct(_Up* __p, _Args&&... __args)
1912        {
1913            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1914        }
1915#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1916        _LIBCPP_INLINE_VISIBILITY
1917        void
1918        construct(pointer __p)
1919        {
1920            ::new((void*) const_cast<_Tp *>(__p)) _Tp();
1921        }
1922# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1923
1924    template <class _A0>
1925        _LIBCPP_INLINE_VISIBILITY
1926        void
1927        construct(pointer __p, _A0& __a0)
1928        {
1929            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
1930        }
1931    template <class _A0>
1932        _LIBCPP_INLINE_VISIBILITY
1933        void
1934        construct(pointer __p, const _A0& __a0)
1935        {
1936            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0);
1937        }
1938# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1939    template <class _A0, class _A1>
1940        _LIBCPP_INLINE_VISIBILITY
1941        void
1942        construct(pointer __p, _A0& __a0, _A1& __a1)
1943        {
1944            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1945        }
1946    template <class _A0, class _A1>
1947        _LIBCPP_INLINE_VISIBILITY
1948        void
1949        construct(pointer __p, const _A0& __a0, _A1& __a1)
1950        {
1951            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1952        }
1953    template <class _A0, class _A1>
1954        _LIBCPP_INLINE_VISIBILITY
1955        void
1956        construct(pointer __p, _A0& __a0, const _A1& __a1)
1957        {
1958            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1959        }
1960    template <class _A0, class _A1>
1961        _LIBCPP_INLINE_VISIBILITY
1962        void
1963        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1964        {
1965            ::new((void*) const_cast<_Tp *>(__p)) _Tp(__a0, __a1);
1966        }
1967#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1968    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1969};
1970
1971template <class _Tp, class _Up>
1972inline _LIBCPP_INLINE_VISIBILITY
1973bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
1974
1975template <class _Tp, class _Up>
1976inline _LIBCPP_INLINE_VISIBILITY
1977bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
1978
1979template <class _OutputIterator, class _Tp>
1980class _LIBCPP_TEMPLATE_VIS raw_storage_iterator
1981    : public iterator<output_iterator_tag,
1982                      _Tp,                                         // purposefully not C++03
1983                      ptrdiff_t,                                   // purposefully not C++03
1984                      _Tp*,                                        // purposefully not C++03
1985                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
1986{
1987private:
1988    _OutputIterator __x_;
1989public:
1990    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
1991    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
1992    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
1993        {::new(_VSTD::addressof(*__x_)) _Tp(__element); return *this;}
1994#if _LIBCPP_STD_VER >= 14
1995    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
1996        {::new(_VSTD::addressof(*__x_)) _Tp(_VSTD::move(__element)); return *this;}
1997#endif
1998    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
1999    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
2000        {raw_storage_iterator __t(*this); ++__x_; return __t;}
2001#if _LIBCPP_STD_VER >= 14
2002    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
2003#endif
2004};
2005
2006template <class _Tp>
2007_LIBCPP_NODISCARD_EXT _LIBCPP_NO_CFI
2008pair<_Tp*, ptrdiff_t>
2009get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
2010{
2011    pair<_Tp*, ptrdiff_t> __r(0, 0);
2012    const ptrdiff_t __m = (~ptrdiff_t(0) ^
2013                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
2014                           / sizeof(_Tp);
2015    if (__n > __m)
2016        __n = __m;
2017    while (__n > 0)
2018    {
2019#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
2020    if (__is_overaligned_for_new(__alignof(_Tp)))
2021        {
2022            std::align_val_t __al =
2023                std::align_val_t(std::alignment_of<_Tp>::value);
2024            __r.first = static_cast<_Tp*>(::operator new(
2025                __n * sizeof(_Tp), __al, nothrow));
2026        } else {
2027            __r.first = static_cast<_Tp*>(::operator new(
2028                __n * sizeof(_Tp), nothrow));
2029        }
2030#else
2031    if (__is_overaligned_for_new(__alignof(_Tp)))
2032        {
2033            // Since aligned operator new is unavailable, return an empty
2034            // buffer rather than one with invalid alignment.
2035            return __r;
2036        }
2037
2038        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
2039#endif
2040
2041        if (__r.first)
2042        {
2043            __r.second = __n;
2044            break;
2045        }
2046        __n /= 2;
2047    }
2048    return __r;
2049}
2050
2051template <class _Tp>
2052inline _LIBCPP_INLINE_VISIBILITY
2053void return_temporary_buffer(_Tp* __p) _NOEXCEPT
2054{
2055  _VSTD::__libcpp_deallocate((void*)__p, __alignof(_Tp));
2056}
2057
2058#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2059template <class _Tp>
2060struct _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr_ref
2061{
2062    _Tp* __ptr_;
2063};
2064
2065template<class _Tp>
2066class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr
2067{
2068private:
2069    _Tp* __ptr_;
2070public:
2071    typedef _Tp element_type;
2072
2073    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) throw() : __ptr_(__p) {}
2074    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) throw() : __ptr_(__p.release()) {}
2075    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) throw()
2076        : __ptr_(__p.release()) {}
2077    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) throw()
2078        {reset(__p.release()); return *this;}
2079    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) throw()
2080        {reset(__p.release()); return *this;}
2081    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) throw()
2082        {reset(__p.__ptr_); return *this;}
2083    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() throw() {delete __ptr_;}
2084
2085    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const throw()
2086        {return *__ptr_;}
2087    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const throw() {return __ptr_;}
2088    _LIBCPP_INLINE_VISIBILITY _Tp* get() const throw() {return __ptr_;}
2089    _LIBCPP_INLINE_VISIBILITY _Tp* release() throw()
2090    {
2091        _Tp* __t = __ptr_;
2092        __ptr_ = 0;
2093        return __t;
2094    }
2095    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) throw()
2096    {
2097        if (__ptr_ != __p)
2098            delete __ptr_;
2099        __ptr_ = __p;
2100    }
2101
2102    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) throw() : __ptr_(__p.__ptr_) {}
2103    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() throw()
2104        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
2105    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() throw()
2106        {return auto_ptr<_Up>(release());}
2107};
2108
2109template <>
2110class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr<void>
2111{
2112public:
2113    typedef void element_type;
2114};
2115#endif
2116
2117template <class _Tp, int _Idx,
2118          bool _CanBeEmptyBase =
2119              is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value>
2120struct __compressed_pair_elem {
2121  typedef _Tp _ParamT;
2122  typedef _Tp& reference;
2123  typedef const _Tp& const_reference;
2124
2125#ifndef _LIBCPP_CXX03_LANG
2126  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() : __value_() {}
2127
2128  template <class _Up, class = typename enable_if<
2129      !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2130  >::type>
2131  _LIBCPP_INLINE_VISIBILITY
2132  constexpr explicit
2133  __compressed_pair_elem(_Up&& __u)
2134      : __value_(_VSTD::forward<_Up>(__u)){};
2135
2136  template <class... _Args, size_t... _Indexes>
2137  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2138  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2139                         __tuple_indices<_Indexes...>)
2140      : __value_(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2141#else
2142  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_() {}
2143  _LIBCPP_INLINE_VISIBILITY
2144  __compressed_pair_elem(_ParamT __p) : __value_(std::forward<_ParamT>(__p)) {}
2145#endif
2146
2147  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return __value_; }
2148  _LIBCPP_INLINE_VISIBILITY
2149  const_reference __get() const _NOEXCEPT { return __value_; }
2150
2151private:
2152  _Tp __value_;
2153};
2154
2155template <class _Tp, int _Idx>
2156struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp {
2157  typedef _Tp _ParamT;
2158  typedef _Tp& reference;
2159  typedef const _Tp& const_reference;
2160  typedef _Tp __value_type;
2161
2162#ifndef _LIBCPP_CXX03_LANG
2163  _LIBCPP_INLINE_VISIBILITY constexpr __compressed_pair_elem() = default;
2164
2165  template <class _Up, class = typename enable_if<
2166        !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2167  >::type>
2168  _LIBCPP_INLINE_VISIBILITY
2169  constexpr explicit
2170  __compressed_pair_elem(_Up&& __u)
2171      : __value_type(_VSTD::forward<_Up>(__u)){};
2172
2173  template <class... _Args, size_t... _Indexes>
2174  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2175  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2176                         __tuple_indices<_Indexes...>)
2177      : __value_type(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2178#else
2179  _LIBCPP_INLINE_VISIBILITY __compressed_pair_elem() : __value_type() {}
2180  _LIBCPP_INLINE_VISIBILITY
2181  __compressed_pair_elem(_ParamT __p)
2182      : __value_type(std::forward<_ParamT>(__p)) {}
2183#endif
2184
2185  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return *this; }
2186  _LIBCPP_INLINE_VISIBILITY
2187  const_reference __get() const _NOEXCEPT { return *this; }
2188};
2189
2190// Tag used to construct the second element of the compressed pair.
2191struct __second_tag {};
2192
2193template <class _T1, class _T2>
2194class __compressed_pair : private __compressed_pair_elem<_T1, 0>,
2195                          private __compressed_pair_elem<_T2, 1> {
2196  typedef __compressed_pair_elem<_T1, 0> _Base1;
2197  typedef __compressed_pair_elem<_T2, 1> _Base2;
2198
2199  // NOTE: This static assert should never fire because __compressed_pair
2200  // is *almost never* used in a scenario where it's possible for T1 == T2.
2201  // (The exception is std::function where it is possible that the function
2202  //  object and the allocator have the same type).
2203  static_assert((!is_same<_T1, _T2>::value),
2204    "__compressed_pair cannot be instantated when T1 and T2 are the same type; "
2205    "The current implementation is NOT ABI-compatible with the previous "
2206    "implementation for this configuration");
2207
2208public:
2209#ifndef _LIBCPP_CXX03_LANG
2210  template <bool _Dummy = true,
2211      class = typename enable_if<
2212          __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
2213          __dependent_type<is_default_constructible<_T2>, _Dummy>::value
2214      >::type
2215  >
2216  _LIBCPP_INLINE_VISIBILITY
2217  constexpr __compressed_pair() {}
2218
2219  template <class _Tp, typename enable_if<!is_same<typename decay<_Tp>::type,
2220                                                   __compressed_pair>::value,
2221                                          bool>::type = true>
2222  _LIBCPP_INLINE_VISIBILITY constexpr explicit
2223  __compressed_pair(_Tp&& __t)
2224      : _Base1(std::forward<_Tp>(__t)), _Base2() {}
2225
2226  template <class _Tp>
2227  _LIBCPP_INLINE_VISIBILITY constexpr
2228  __compressed_pair(__second_tag, _Tp&& __t)
2229      : _Base1(), _Base2(std::forward<_Tp>(__t)) {}
2230
2231  template <class _U1, class _U2>
2232  _LIBCPP_INLINE_VISIBILITY constexpr
2233  __compressed_pair(_U1&& __t1, _U2&& __t2)
2234      : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {}
2235
2236  template <class... _Args1, class... _Args2>
2237  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2238  __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
2239                    tuple<_Args2...> __second_args)
2240      : _Base1(__pc, _VSTD::move(__first_args),
2241               typename __make_tuple_indices<sizeof...(_Args1)>::type()),
2242        _Base2(__pc, _VSTD::move(__second_args),
2243               typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}
2244
2245#else
2246  _LIBCPP_INLINE_VISIBILITY
2247  __compressed_pair() {}
2248
2249  _LIBCPP_INLINE_VISIBILITY explicit
2250  __compressed_pair(_T1 __t1) : _Base1(_VSTD::forward<_T1>(__t1)) {}
2251
2252  _LIBCPP_INLINE_VISIBILITY
2253  __compressed_pair(__second_tag, _T2 __t2)
2254      : _Base1(), _Base2(_VSTD::forward<_T2>(__t2)) {}
2255
2256  _LIBCPP_INLINE_VISIBILITY
2257  __compressed_pair(_T1 __t1, _T2 __t2)
2258      : _Base1(_VSTD::forward<_T1>(__t1)), _Base2(_VSTD::forward<_T2>(__t2)) {}
2259#endif
2260
2261  _LIBCPP_INLINE_VISIBILITY
2262  typename _Base1::reference first() _NOEXCEPT {
2263    return static_cast<_Base1&>(*this).__get();
2264  }
2265
2266  _LIBCPP_INLINE_VISIBILITY
2267  typename _Base1::const_reference first() const _NOEXCEPT {
2268    return static_cast<_Base1 const&>(*this).__get();
2269  }
2270
2271  _LIBCPP_INLINE_VISIBILITY
2272  typename _Base2::reference second() _NOEXCEPT {
2273    return static_cast<_Base2&>(*this).__get();
2274  }
2275
2276  _LIBCPP_INLINE_VISIBILITY
2277  typename _Base2::const_reference second() const _NOEXCEPT {
2278    return static_cast<_Base2 const&>(*this).__get();
2279  }
2280
2281  _LIBCPP_INLINE_VISIBILITY
2282  void swap(__compressed_pair& __x)
2283    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2284               __is_nothrow_swappable<_T2>::value)
2285  {
2286    using std::swap;
2287    swap(first(), __x.first());
2288    swap(second(), __x.second());
2289  }
2290};
2291
2292template <class _T1, class _T2>
2293inline _LIBCPP_INLINE_VISIBILITY
2294void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
2295    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2296               __is_nothrow_swappable<_T2>::value) {
2297  __x.swap(__y);
2298}
2299
2300// default_delete
2301
2302template <class _Tp>
2303struct _LIBCPP_TEMPLATE_VIS default_delete {
2304    static_assert(!is_function<_Tp>::value,
2305                  "default_delete cannot be instantiated for function types");
2306#ifndef _LIBCPP_CXX03_LANG
2307  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() noexcept = default;
2308#else
2309  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2310#endif
2311  template <class _Up>
2312  _LIBCPP_INLINE_VISIBILITY
2313  default_delete(const default_delete<_Up>&,
2314                 typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* =
2315                     0) _NOEXCEPT {}
2316
2317  _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __ptr) const _NOEXCEPT {
2318    static_assert(sizeof(_Tp) > 0,
2319                  "default_delete can not delete incomplete type");
2320    static_assert(!is_void<_Tp>::value,
2321                  "default_delete can not delete incomplete type");
2322    delete __ptr;
2323  }
2324};
2325
2326template <class _Tp>
2327struct _LIBCPP_TEMPLATE_VIS default_delete<_Tp[]> {
2328private:
2329  template <class _Up>
2330  struct _EnableIfConvertible
2331      : enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value> {};
2332
2333public:
2334#ifndef _LIBCPP_CXX03_LANG
2335  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() noexcept = default;
2336#else
2337  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2338#endif
2339
2340  template <class _Up>
2341  _LIBCPP_INLINE_VISIBILITY
2342  default_delete(const default_delete<_Up[]>&,
2343                 typename _EnableIfConvertible<_Up>::type* = 0) _NOEXCEPT {}
2344
2345  template <class _Up>
2346  _LIBCPP_INLINE_VISIBILITY
2347  typename _EnableIfConvertible<_Up>::type
2348  operator()(_Up* __ptr) const _NOEXCEPT {
2349    static_assert(sizeof(_Tp) > 0,
2350                  "default_delete can not delete incomplete type");
2351    static_assert(!is_void<_Tp>::value,
2352                  "default_delete can not delete void type");
2353    delete[] __ptr;
2354  }
2355};
2356
2357
2358
2359#ifndef _LIBCPP_CXX03_LANG
2360template <class _Deleter>
2361struct __unique_ptr_deleter_sfinae {
2362  static_assert(!is_reference<_Deleter>::value, "incorrect specialization");
2363  typedef const _Deleter& __lval_ref_type;
2364  typedef _Deleter&& __good_rval_ref_type;
2365  typedef true_type __enable_rval_overload;
2366};
2367
2368template <class _Deleter>
2369struct __unique_ptr_deleter_sfinae<_Deleter const&> {
2370  typedef const _Deleter& __lval_ref_type;
2371  typedef const _Deleter&& __bad_rval_ref_type;
2372  typedef false_type __enable_rval_overload;
2373};
2374
2375template <class _Deleter>
2376struct __unique_ptr_deleter_sfinae<_Deleter&> {
2377  typedef _Deleter& __lval_ref_type;
2378  typedef _Deleter&& __bad_rval_ref_type;
2379  typedef false_type __enable_rval_overload;
2380};
2381#endif // !defined(_LIBCPP_CXX03_LANG)
2382
2383template <class _Tp, class _Dp = default_delete<_Tp> >
2384class _LIBCPP_TEMPLATE_VIS unique_ptr {
2385public:
2386  typedef _Tp element_type;
2387  typedef _Dp deleter_type;
2388  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2389
2390  static_assert(!is_rvalue_reference<deleter_type>::value,
2391                "the specified deleter type cannot be an rvalue reference");
2392
2393private:
2394  __compressed_pair<pointer, deleter_type> __ptr_;
2395
2396  struct __nat { int __for_bool_; };
2397
2398#ifndef _LIBCPP_CXX03_LANG
2399  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2400
2401  template <bool _Dummy>
2402  using _LValRefType =
2403      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2404
2405  template <bool _Dummy>
2406  using _GoodRValRefType =
2407      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2408
2409  template <bool _Dummy>
2410  using _BadRValRefType =
2411      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2412
2413  template <bool _Dummy, class _Deleter = typename __dependent_type<
2414                             __identity<deleter_type>, _Dummy>::type>
2415  using _EnableIfDeleterDefaultConstructible =
2416      typename enable_if<is_default_constructible<_Deleter>::value &&
2417                         !is_pointer<_Deleter>::value>::type;
2418
2419  template <class _ArgType>
2420  using _EnableIfDeleterConstructible =
2421      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2422
2423  template <class _UPtr, class _Up>
2424  using _EnableIfMoveConvertible = typename enable_if<
2425      is_convertible<typename _UPtr::pointer, pointer>::value &&
2426      !is_array<_Up>::value
2427  >::type;
2428
2429  template <class _UDel>
2430  using _EnableIfDeleterConvertible = typename enable_if<
2431      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2432      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2433    >::type;
2434
2435  template <class _UDel>
2436  using _EnableIfDeleterAssignable = typename enable_if<
2437      is_assignable<_Dp&, _UDel&&>::value
2438    >::type;
2439
2440public:
2441  template <bool _Dummy = true,
2442            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2443  _LIBCPP_INLINE_VISIBILITY
2444  constexpr unique_ptr() noexcept : __ptr_(pointer()) {}
2445
2446  template <bool _Dummy = true,
2447            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2448  _LIBCPP_INLINE_VISIBILITY
2449  constexpr unique_ptr(nullptr_t) noexcept : __ptr_(pointer()) {}
2450
2451  template <bool _Dummy = true,
2452            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2453  _LIBCPP_INLINE_VISIBILITY
2454  explicit unique_ptr(pointer __p) noexcept : __ptr_(__p) {}
2455
2456  template <bool _Dummy = true,
2457            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>>
2458  _LIBCPP_INLINE_VISIBILITY
2459  unique_ptr(pointer __p, _LValRefType<_Dummy> __d) noexcept
2460      : __ptr_(__p, __d) {}
2461
2462  template <bool _Dummy = true,
2463            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>>
2464  _LIBCPP_INLINE_VISIBILITY
2465  unique_ptr(pointer __p, _GoodRValRefType<_Dummy> __d) noexcept
2466      : __ptr_(__p, _VSTD::move(__d)) {
2467    static_assert(!is_reference<deleter_type>::value,
2468                  "rvalue deleter bound to reference");
2469  }
2470
2471  template <bool _Dummy = true,
2472            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy>>>
2473  _LIBCPP_INLINE_VISIBILITY
2474  unique_ptr(pointer __p, _BadRValRefType<_Dummy> __d) = delete;
2475
2476  _LIBCPP_INLINE_VISIBILITY
2477  unique_ptr(unique_ptr&& __u) noexcept
2478      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2479  }
2480
2481  template <class _Up, class _Ep,
2482      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2483      class = _EnableIfDeleterConvertible<_Ep>
2484  >
2485  _LIBCPP_INLINE_VISIBILITY
2486  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2487      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
2488
2489#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2490  template <class _Up>
2491  _LIBCPP_INLINE_VISIBILITY
2492  unique_ptr(auto_ptr<_Up>&& __p,
2493             typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2494                                    is_same<_Dp, default_delete<_Tp>>::value,
2495                                __nat>::type = __nat()) _NOEXCEPT
2496      : __ptr_(__p.release()) {}
2497#endif
2498
2499  _LIBCPP_INLINE_VISIBILITY
2500  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2501    reset(__u.release());
2502    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2503    return *this;
2504  }
2505
2506  template <class _Up, class _Ep,
2507      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2508      class = _EnableIfDeleterAssignable<_Ep>
2509  >
2510  _LIBCPP_INLINE_VISIBILITY
2511  unique_ptr& operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2512    reset(__u.release());
2513    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2514    return *this;
2515  }
2516
2517#else  // _LIBCPP_CXX03_LANG
2518private:
2519  unique_ptr(unique_ptr&);
2520  template <class _Up, class _Ep> unique_ptr(unique_ptr<_Up, _Ep>&);
2521
2522  unique_ptr& operator=(unique_ptr&);
2523  template <class _Up, class _Ep> unique_ptr& operator=(unique_ptr<_Up, _Ep>&);
2524
2525public:
2526  _LIBCPP_INLINE_VISIBILITY
2527  unique_ptr() : __ptr_(pointer())
2528  {
2529    static_assert(!is_pointer<deleter_type>::value,
2530                  "unique_ptr constructed with null function pointer deleter");
2531    static_assert(is_default_constructible<deleter_type>::value,
2532                  "unique_ptr::deleter_type is not default constructible");
2533  }
2534  _LIBCPP_INLINE_VISIBILITY
2535  unique_ptr(nullptr_t) : __ptr_(pointer())
2536  {
2537    static_assert(!is_pointer<deleter_type>::value,
2538                  "unique_ptr constructed with null function pointer deleter");
2539  }
2540  _LIBCPP_INLINE_VISIBILITY
2541  explicit unique_ptr(pointer __p)
2542      : __ptr_(_VSTD::move(__p)) {
2543    static_assert(!is_pointer<deleter_type>::value,
2544                  "unique_ptr constructed with null function pointer deleter");
2545  }
2546
2547  _LIBCPP_INLINE_VISIBILITY
2548  operator __rv<unique_ptr>() {
2549    return __rv<unique_ptr>(*this);
2550  }
2551
2552  _LIBCPP_INLINE_VISIBILITY
2553  unique_ptr(__rv<unique_ptr> __u)
2554      : __ptr_(__u->release(),
2555               _VSTD::forward<deleter_type>(__u->get_deleter())) {}
2556
2557  template <class _Up, class _Ep>
2558  _LIBCPP_INLINE_VISIBILITY
2559  typename enable_if<
2560      !is_array<_Up>::value &&
2561          is_convertible<typename unique_ptr<_Up, _Ep>::pointer,
2562                         pointer>::value &&
2563          is_assignable<deleter_type&, _Ep&>::value,
2564      unique_ptr&>::type
2565  operator=(unique_ptr<_Up, _Ep> __u) {
2566    reset(__u.release());
2567    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2568    return *this;
2569  }
2570
2571  _LIBCPP_INLINE_VISIBILITY
2572  unique_ptr(pointer __p, deleter_type __d)
2573      : __ptr_(_VSTD::move(__p), _VSTD::move(__d)) {}
2574#endif // _LIBCPP_CXX03_LANG
2575
2576#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2577  template <class _Up>
2578  _LIBCPP_INLINE_VISIBILITY
2579      typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2580                             is_same<_Dp, default_delete<_Tp> >::value,
2581                         unique_ptr&>::type
2582      operator=(auto_ptr<_Up> __p) {
2583    reset(__p.release());
2584    return *this;
2585  }
2586#endif
2587
2588  _LIBCPP_INLINE_VISIBILITY
2589  ~unique_ptr() { reset(); }
2590
2591  _LIBCPP_INLINE_VISIBILITY
2592  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2593    reset();
2594    return *this;
2595  }
2596
2597  _LIBCPP_INLINE_VISIBILITY
2598  typename add_lvalue_reference<_Tp>::type
2599  operator*() const {
2600    return *__ptr_.first();
2601  }
2602  _LIBCPP_INLINE_VISIBILITY
2603  pointer operator->() const _NOEXCEPT {
2604    return __ptr_.first();
2605  }
2606  _LIBCPP_INLINE_VISIBILITY
2607  pointer get() const _NOEXCEPT {
2608    return __ptr_.first();
2609  }
2610  _LIBCPP_INLINE_VISIBILITY
2611  deleter_type& get_deleter() _NOEXCEPT {
2612    return __ptr_.second();
2613  }
2614  _LIBCPP_INLINE_VISIBILITY
2615  const deleter_type& get_deleter() const _NOEXCEPT {
2616    return __ptr_.second();
2617  }
2618  _LIBCPP_INLINE_VISIBILITY
2619  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2620    return __ptr_.first() != nullptr;
2621  }
2622
2623  _LIBCPP_INLINE_VISIBILITY
2624  pointer release() _NOEXCEPT {
2625    pointer __t = __ptr_.first();
2626    __ptr_.first() = pointer();
2627    return __t;
2628  }
2629
2630  _LIBCPP_INLINE_VISIBILITY
2631  void reset(pointer __p = pointer()) _NOEXCEPT {
2632    pointer __tmp = __ptr_.first();
2633    __ptr_.first() = __p;
2634    if (__tmp)
2635      __ptr_.second()(__tmp);
2636  }
2637
2638  _LIBCPP_INLINE_VISIBILITY
2639  void swap(unique_ptr& __u) _NOEXCEPT {
2640    __ptr_.swap(__u.__ptr_);
2641  }
2642};
2643
2644
2645template <class _Tp, class _Dp>
2646class _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
2647public:
2648  typedef _Tp element_type;
2649  typedef _Dp deleter_type;
2650  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2651
2652private:
2653  __compressed_pair<pointer, deleter_type> __ptr_;
2654
2655  template <class _From>
2656  struct _CheckArrayPointerConversion : is_same<_From, pointer> {};
2657
2658  template <class _FromElem>
2659  struct _CheckArrayPointerConversion<_FromElem*>
2660      : integral_constant<bool,
2661          is_same<_FromElem*, pointer>::value ||
2662            (is_same<pointer, element_type*>::value &&
2663             is_convertible<_FromElem(*)[], element_type(*)[]>::value)
2664      >
2665  {};
2666
2667#ifndef _LIBCPP_CXX03_LANG
2668  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2669
2670  template <bool _Dummy>
2671  using _LValRefType =
2672      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2673
2674  template <bool _Dummy>
2675  using _GoodRValRefType =
2676      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2677
2678  template <bool _Dummy>
2679  using _BadRValRefType =
2680      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2681
2682  template <bool _Dummy, class _Deleter = typename __dependent_type<
2683                             __identity<deleter_type>, _Dummy>::type>
2684  using _EnableIfDeleterDefaultConstructible =
2685      typename enable_if<is_default_constructible<_Deleter>::value &&
2686                         !is_pointer<_Deleter>::value>::type;
2687
2688  template <class _ArgType>
2689  using _EnableIfDeleterConstructible =
2690      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2691
2692  template <class _Pp>
2693  using _EnableIfPointerConvertible = typename enable_if<
2694      _CheckArrayPointerConversion<_Pp>::value
2695  >::type;
2696
2697  template <class _UPtr, class _Up,
2698        class _ElemT = typename _UPtr::element_type>
2699  using _EnableIfMoveConvertible = typename enable_if<
2700      is_array<_Up>::value &&
2701      is_same<pointer, element_type*>::value &&
2702      is_same<typename _UPtr::pointer, _ElemT*>::value &&
2703      is_convertible<_ElemT(*)[], element_type(*)[]>::value
2704    >::type;
2705
2706  template <class _UDel>
2707  using _EnableIfDeleterConvertible = typename enable_if<
2708      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2709      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2710    >::type;
2711
2712  template <class _UDel>
2713  using _EnableIfDeleterAssignable = typename enable_if<
2714      is_assignable<_Dp&, _UDel&&>::value
2715    >::type;
2716
2717public:
2718  template <bool _Dummy = true,
2719            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2720  _LIBCPP_INLINE_VISIBILITY
2721  constexpr unique_ptr() noexcept : __ptr_(pointer()) {}
2722
2723  template <bool _Dummy = true,
2724            class = _EnableIfDeleterDefaultConstructible<_Dummy>>
2725  _LIBCPP_INLINE_VISIBILITY
2726  constexpr unique_ptr(nullptr_t) noexcept : __ptr_(pointer()) {}
2727
2728  template <class _Pp, bool _Dummy = true,
2729            class = _EnableIfDeleterDefaultConstructible<_Dummy>,
2730            class = _EnableIfPointerConvertible<_Pp>>
2731  _LIBCPP_INLINE_VISIBILITY
2732  explicit unique_ptr(_Pp __p) noexcept
2733      : __ptr_(__p) {}
2734
2735  template <class _Pp, bool _Dummy = true,
2736            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>,
2737            class = _EnableIfPointerConvertible<_Pp>>
2738  _LIBCPP_INLINE_VISIBILITY
2739  unique_ptr(_Pp __p, _LValRefType<_Dummy> __d) noexcept
2740      : __ptr_(__p, __d) {}
2741
2742  template <bool _Dummy = true,
2743            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy>>>
2744  _LIBCPP_INLINE_VISIBILITY
2745  unique_ptr(nullptr_t, _LValRefType<_Dummy> __d) noexcept
2746      : __ptr_(nullptr, __d) {}
2747
2748  template <class _Pp, bool _Dummy = true,
2749            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>,
2750            class = _EnableIfPointerConvertible<_Pp>>
2751  _LIBCPP_INLINE_VISIBILITY
2752  unique_ptr(_Pp __p, _GoodRValRefType<_Dummy> __d) noexcept
2753      : __ptr_(__p, _VSTD::move(__d)) {
2754    static_assert(!is_reference<deleter_type>::value,
2755                  "rvalue deleter bound to reference");
2756  }
2757
2758  template <bool _Dummy = true,
2759            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy>>>
2760  _LIBCPP_INLINE_VISIBILITY
2761  unique_ptr(nullptr_t, _GoodRValRefType<_Dummy> __d) noexcept
2762      : __ptr_(nullptr, _VSTD::move(__d)) {
2763    static_assert(!is_reference<deleter_type>::value,
2764                  "rvalue deleter bound to reference");
2765  }
2766
2767  template <class _Pp, bool _Dummy = true,
2768            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy>>,
2769            class = _EnableIfPointerConvertible<_Pp>>
2770  _LIBCPP_INLINE_VISIBILITY
2771  unique_ptr(_Pp __p, _BadRValRefType<_Dummy> __d) = delete;
2772
2773  _LIBCPP_INLINE_VISIBILITY
2774  unique_ptr(unique_ptr&& __u) noexcept
2775      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2776  }
2777
2778  _LIBCPP_INLINE_VISIBILITY
2779  unique_ptr& operator=(unique_ptr&& __u) noexcept {
2780    reset(__u.release());
2781    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2782    return *this;
2783  }
2784
2785  template <class _Up, class _Ep,
2786      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2787      class = _EnableIfDeleterConvertible<_Ep>
2788  >
2789  _LIBCPP_INLINE_VISIBILITY
2790  unique_ptr(unique_ptr<_Up, _Ep>&& __u) noexcept
2791      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {
2792  }
2793
2794  template <class _Up, class _Ep,
2795      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2796      class = _EnableIfDeleterAssignable<_Ep>
2797  >
2798  _LIBCPP_INLINE_VISIBILITY
2799  unique_ptr&
2800  operator=(unique_ptr<_Up, _Ep>&& __u) noexcept {
2801    reset(__u.release());
2802    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2803    return *this;
2804  }
2805
2806#else // _LIBCPP_CXX03_LANG
2807private:
2808  template <class _Up> explicit unique_ptr(_Up);
2809
2810  unique_ptr(unique_ptr&);
2811  template <class _Up> unique_ptr(unique_ptr<_Up>&);
2812
2813  unique_ptr& operator=(unique_ptr&);
2814  template <class _Up> unique_ptr& operator=(unique_ptr<_Up>&);
2815
2816  template <class _Up>
2817  unique_ptr(_Up __u,
2818             typename conditional<
2819                 is_reference<deleter_type>::value, deleter_type,
2820                 typename add_lvalue_reference<const deleter_type>::type>::type,
2821             typename enable_if<is_convertible<_Up, pointer>::value,
2822                                __nat>::type = __nat());
2823public:
2824  _LIBCPP_INLINE_VISIBILITY
2825  unique_ptr() : __ptr_(pointer()) {
2826    static_assert(!is_pointer<deleter_type>::value,
2827                  "unique_ptr constructed with null function pointer deleter");
2828  }
2829  _LIBCPP_INLINE_VISIBILITY
2830  unique_ptr(nullptr_t) : __ptr_(pointer()) {
2831    static_assert(!is_pointer<deleter_type>::value,
2832                  "unique_ptr constructed with null function pointer deleter");
2833  }
2834
2835  _LIBCPP_INLINE_VISIBILITY
2836  explicit unique_ptr(pointer __p) : __ptr_(__p) {
2837    static_assert(!is_pointer<deleter_type>::value,
2838                  "unique_ptr constructed with null function pointer deleter");
2839  }
2840
2841  _LIBCPP_INLINE_VISIBILITY
2842  unique_ptr(pointer __p, deleter_type __d)
2843      : __ptr_(__p, _VSTD::forward<deleter_type>(__d)) {}
2844
2845  _LIBCPP_INLINE_VISIBILITY
2846  unique_ptr(nullptr_t, deleter_type __d)
2847      : __ptr_(pointer(), _VSTD::forward<deleter_type>(__d)) {}
2848
2849  _LIBCPP_INLINE_VISIBILITY
2850  operator __rv<unique_ptr>() {
2851    return __rv<unique_ptr>(*this);
2852  }
2853
2854  _LIBCPP_INLINE_VISIBILITY
2855  unique_ptr(__rv<unique_ptr> __u)
2856      : __ptr_(__u->release(),
2857               _VSTD::forward<deleter_type>(__u->get_deleter())) {}
2858
2859  _LIBCPP_INLINE_VISIBILITY
2860  unique_ptr& operator=(__rv<unique_ptr> __u) {
2861    reset(__u->release());
2862    __ptr_.second() = _VSTD::forward<deleter_type>(__u->get_deleter());
2863    return *this;
2864  }
2865
2866#endif // _LIBCPP_CXX03_LANG
2867
2868public:
2869  _LIBCPP_INLINE_VISIBILITY
2870  ~unique_ptr() { reset(); }
2871
2872  _LIBCPP_INLINE_VISIBILITY
2873  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2874    reset();
2875    return *this;
2876  }
2877
2878  _LIBCPP_INLINE_VISIBILITY
2879  typename add_lvalue_reference<_Tp>::type
2880  operator[](size_t __i) const {
2881    return __ptr_.first()[__i];
2882  }
2883  _LIBCPP_INLINE_VISIBILITY
2884  pointer get() const _NOEXCEPT {
2885    return __ptr_.first();
2886  }
2887
2888  _LIBCPP_INLINE_VISIBILITY
2889  deleter_type& get_deleter() _NOEXCEPT {
2890    return __ptr_.second();
2891  }
2892
2893  _LIBCPP_INLINE_VISIBILITY
2894  const deleter_type& get_deleter() const _NOEXCEPT {
2895    return __ptr_.second();
2896  }
2897  _LIBCPP_INLINE_VISIBILITY
2898  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2899    return __ptr_.first() != nullptr;
2900  }
2901
2902  _LIBCPP_INLINE_VISIBILITY
2903  pointer release() _NOEXCEPT {
2904    pointer __t = __ptr_.first();
2905    __ptr_.first() = pointer();
2906    return __t;
2907  }
2908
2909  template <class _Pp>
2910  _LIBCPP_INLINE_VISIBILITY
2911  typename enable_if<
2912      _CheckArrayPointerConversion<_Pp>::value
2913  >::type
2914  reset(_Pp __p) _NOEXCEPT {
2915    pointer __tmp = __ptr_.first();
2916    __ptr_.first() = __p;
2917    if (__tmp)
2918      __ptr_.second()(__tmp);
2919  }
2920
2921  _LIBCPP_INLINE_VISIBILITY
2922  void reset(nullptr_t = nullptr) _NOEXCEPT {
2923    pointer __tmp = __ptr_.first();
2924    __ptr_.first() = nullptr;
2925    if (__tmp)
2926      __ptr_.second()(__tmp);
2927  }
2928
2929  _LIBCPP_INLINE_VISIBILITY
2930  void swap(unique_ptr& __u) _NOEXCEPT {
2931    __ptr_.swap(__u.__ptr_);
2932  }
2933
2934};
2935
2936template <class _Tp, class _Dp>
2937inline _LIBCPP_INLINE_VISIBILITY
2938typename enable_if<
2939    __is_swappable<_Dp>::value,
2940    void
2941>::type
2942swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
2943
2944template <class _T1, class _D1, class _T2, class _D2>
2945inline _LIBCPP_INLINE_VISIBILITY
2946bool
2947operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
2948
2949template <class _T1, class _D1, class _T2, class _D2>
2950inline _LIBCPP_INLINE_VISIBILITY
2951bool
2952operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
2953
2954template <class _T1, class _D1, class _T2, class _D2>
2955inline _LIBCPP_INLINE_VISIBILITY
2956bool
2957operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
2958{
2959    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2960    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
2961    typedef typename common_type<_P1, _P2>::type _Vp;
2962    return less<_Vp>()(__x.get(), __y.get());
2963}
2964
2965template <class _T1, class _D1, class _T2, class _D2>
2966inline _LIBCPP_INLINE_VISIBILITY
2967bool
2968operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
2969
2970template <class _T1, class _D1, class _T2, class _D2>
2971inline _LIBCPP_INLINE_VISIBILITY
2972bool
2973operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
2974
2975template <class _T1, class _D1, class _T2, class _D2>
2976inline _LIBCPP_INLINE_VISIBILITY
2977bool
2978operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
2979
2980template <class _T1, class _D1>
2981inline _LIBCPP_INLINE_VISIBILITY
2982bool
2983operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2984{
2985    return !__x;
2986}
2987
2988template <class _T1, class _D1>
2989inline _LIBCPP_INLINE_VISIBILITY
2990bool
2991operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2992{
2993    return !__x;
2994}
2995
2996template <class _T1, class _D1>
2997inline _LIBCPP_INLINE_VISIBILITY
2998bool
2999operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
3000{
3001    return static_cast<bool>(__x);
3002}
3003
3004template <class _T1, class _D1>
3005inline _LIBCPP_INLINE_VISIBILITY
3006bool
3007operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
3008{
3009    return static_cast<bool>(__x);
3010}
3011
3012template <class _T1, class _D1>
3013inline _LIBCPP_INLINE_VISIBILITY
3014bool
3015operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3016{
3017    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
3018    return less<_P1>()(__x.get(), nullptr);
3019}
3020
3021template <class _T1, class _D1>
3022inline _LIBCPP_INLINE_VISIBILITY
3023bool
3024operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3025{
3026    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
3027    return less<_P1>()(nullptr, __x.get());
3028}
3029
3030template <class _T1, class _D1>
3031inline _LIBCPP_INLINE_VISIBILITY
3032bool
3033operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3034{
3035    return nullptr < __x;
3036}
3037
3038template <class _T1, class _D1>
3039inline _LIBCPP_INLINE_VISIBILITY
3040bool
3041operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3042{
3043    return __x < nullptr;
3044}
3045
3046template <class _T1, class _D1>
3047inline _LIBCPP_INLINE_VISIBILITY
3048bool
3049operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3050{
3051    return !(nullptr < __x);
3052}
3053
3054template <class _T1, class _D1>
3055inline _LIBCPP_INLINE_VISIBILITY
3056bool
3057operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3058{
3059    return !(__x < nullptr);
3060}
3061
3062template <class _T1, class _D1>
3063inline _LIBCPP_INLINE_VISIBILITY
3064bool
3065operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3066{
3067    return !(__x < nullptr);
3068}
3069
3070template <class _T1, class _D1>
3071inline _LIBCPP_INLINE_VISIBILITY
3072bool
3073operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3074{
3075    return !(nullptr < __x);
3076}
3077
3078#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3079
3080template <class _Tp, class _Dp>
3081inline _LIBCPP_INLINE_VISIBILITY
3082unique_ptr<_Tp, _Dp>
3083move(unique_ptr<_Tp, _Dp>& __t)
3084{
3085    return unique_ptr<_Tp, _Dp>(__rv<unique_ptr<_Tp, _Dp> >(__t));
3086}
3087
3088#endif
3089
3090#if _LIBCPP_STD_VER > 11
3091
3092template<class _Tp>
3093struct __unique_if
3094{
3095    typedef unique_ptr<_Tp> __unique_single;
3096};
3097
3098template<class _Tp>
3099struct __unique_if<_Tp[]>
3100{
3101    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
3102};
3103
3104template<class _Tp, size_t _Np>
3105struct __unique_if<_Tp[_Np]>
3106{
3107    typedef void __unique_array_known_bound;
3108};
3109
3110template<class _Tp, class... _Args>
3111inline _LIBCPP_INLINE_VISIBILITY
3112typename __unique_if<_Tp>::__unique_single
3113make_unique(_Args&&... __args)
3114{
3115    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
3116}
3117
3118template<class _Tp>
3119inline _LIBCPP_INLINE_VISIBILITY
3120typename __unique_if<_Tp>::__unique_array_unknown_bound
3121make_unique(size_t __n)
3122{
3123    typedef typename remove_extent<_Tp>::type _Up;
3124    return unique_ptr<_Tp>(new _Up[__n]());
3125}
3126
3127template<class _Tp, class... _Args>
3128    typename __unique_if<_Tp>::__unique_array_known_bound
3129    make_unique(_Args&&...) = delete;
3130
3131#endif  // _LIBCPP_STD_VER > 11
3132
3133template <class _Tp, class _Dp>
3134#ifdef _LIBCPP_CXX03_LANG
3135struct _LIBCPP_TEMPLATE_VIS hash<unique_ptr<_Tp, _Dp> >
3136#else
3137struct _LIBCPP_TEMPLATE_VIS hash<__enable_hash_helper<
3138    unique_ptr<_Tp, _Dp>, typename unique_ptr<_Tp, _Dp>::pointer>>
3139#endif
3140{
3141    typedef unique_ptr<_Tp, _Dp> argument_type;
3142    typedef size_t               result_type;
3143    _LIBCPP_INLINE_VISIBILITY
3144    result_type operator()(const argument_type& __ptr) const
3145    {
3146        typedef typename argument_type::pointer pointer;
3147        return hash<pointer>()(__ptr.get());
3148    }
3149};
3150
3151struct __destruct_n
3152{
3153private:
3154    size_t __size_;
3155
3156    template <class _Tp>
3157    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
3158        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
3159
3160    template <class _Tp>
3161    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
3162        {}
3163
3164    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
3165        {++__size_;}
3166    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
3167        {}
3168
3169    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
3170        {__size_ = __s;}
3171    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
3172        {}
3173public:
3174    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
3175        : __size_(__s) {}
3176
3177    template <class _Tp>
3178    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
3179        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3180
3181    template <class _Tp>
3182    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
3183        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3184
3185    template <class _Tp>
3186    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
3187        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3188};
3189
3190template <class _Alloc>
3191class __allocator_destructor
3192{
3193    typedef allocator_traits<_Alloc> __alloc_traits;
3194public:
3195    typedef typename __alloc_traits::pointer pointer;
3196    typedef typename __alloc_traits::size_type size_type;
3197private:
3198    _Alloc& __alloc_;
3199    size_type __s_;
3200public:
3201    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
3202             _NOEXCEPT
3203        : __alloc_(__a), __s_(__s) {}
3204    _LIBCPP_INLINE_VISIBILITY
3205    void operator()(pointer __p) _NOEXCEPT
3206        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
3207};
3208
3209template <class _InputIterator, class _ForwardIterator>
3210_ForwardIterator
3211uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
3212{
3213    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3214#ifndef _LIBCPP_NO_EXCEPTIONS
3215    _ForwardIterator __s = __r;
3216    try
3217    {
3218#endif
3219        for (; __f != __l; ++__f, (void) ++__r)
3220            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3221#ifndef _LIBCPP_NO_EXCEPTIONS
3222    }
3223    catch (...)
3224    {
3225        for (; __s != __r; ++__s)
3226            __s->~value_type();
3227        throw;
3228    }
3229#endif
3230    return __r;
3231}
3232
3233template <class _InputIterator, class _Size, class _ForwardIterator>
3234_ForwardIterator
3235uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
3236{
3237    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3238#ifndef _LIBCPP_NO_EXCEPTIONS
3239    _ForwardIterator __s = __r;
3240    try
3241    {
3242#endif
3243        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
3244            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3245#ifndef _LIBCPP_NO_EXCEPTIONS
3246    }
3247    catch (...)
3248    {
3249        for (; __s != __r; ++__s)
3250            __s->~value_type();
3251        throw;
3252    }
3253#endif
3254    return __r;
3255}
3256
3257template <class _ForwardIterator, class _Tp>
3258void
3259uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
3260{
3261    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3262#ifndef _LIBCPP_NO_EXCEPTIONS
3263    _ForwardIterator __s = __f;
3264    try
3265    {
3266#endif
3267        for (; __f != __l; ++__f)
3268            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3269#ifndef _LIBCPP_NO_EXCEPTIONS
3270    }
3271    catch (...)
3272    {
3273        for (; __s != __f; ++__s)
3274            __s->~value_type();
3275        throw;
3276    }
3277#endif
3278}
3279
3280template <class _ForwardIterator, class _Size, class _Tp>
3281_ForwardIterator
3282uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
3283{
3284    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3285#ifndef _LIBCPP_NO_EXCEPTIONS
3286    _ForwardIterator __s = __f;
3287    try
3288    {
3289#endif
3290        for (; __n > 0; ++__f, (void) --__n)
3291            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3292#ifndef _LIBCPP_NO_EXCEPTIONS
3293    }
3294    catch (...)
3295    {
3296        for (; __s != __f; ++__s)
3297            __s->~value_type();
3298        throw;
3299    }
3300#endif
3301    return __f;
3302}
3303
3304#if _LIBCPP_STD_VER > 14
3305
3306template <class _Tp>
3307inline _LIBCPP_INLINE_VISIBILITY
3308void destroy_at(_Tp* __loc) {
3309    _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
3310    __loc->~_Tp();
3311}
3312
3313template <class _ForwardIterator>
3314inline _LIBCPP_INLINE_VISIBILITY
3315void destroy(_ForwardIterator __first, _ForwardIterator __last) {
3316    for (; __first != __last; ++__first)
3317        _VSTD::destroy_at(_VSTD::addressof(*__first));
3318}
3319
3320template <class _ForwardIterator, class _Size>
3321inline _LIBCPP_INLINE_VISIBILITY
3322_ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
3323    for (; __n > 0; (void)++__first, --__n)
3324        _VSTD::destroy_at(_VSTD::addressof(*__first));
3325    return __first;
3326}
3327
3328template <class _ForwardIterator>
3329inline _LIBCPP_INLINE_VISIBILITY
3330void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
3331    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3332    auto __idx = __first;
3333#ifndef _LIBCPP_NO_EXCEPTIONS
3334    try {
3335#endif
3336    for (; __idx != __last; ++__idx)
3337        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3338#ifndef _LIBCPP_NO_EXCEPTIONS
3339    } catch (...) {
3340        _VSTD::destroy(__first, __idx);
3341        throw;
3342    }
3343#endif
3344}
3345
3346template <class _ForwardIterator, class _Size>
3347inline _LIBCPP_INLINE_VISIBILITY
3348_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
3349    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3350    auto __idx = __first;
3351#ifndef _LIBCPP_NO_EXCEPTIONS
3352    try {
3353#endif
3354    for (; __n > 0; (void)++__idx, --__n)
3355        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3356    return __idx;
3357#ifndef _LIBCPP_NO_EXCEPTIONS
3358    } catch (...) {
3359        _VSTD::destroy(__first, __idx);
3360        throw;
3361    }
3362#endif
3363}
3364
3365
3366template <class _ForwardIterator>
3367inline _LIBCPP_INLINE_VISIBILITY
3368void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
3369    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3370    auto __idx = __first;
3371#ifndef _LIBCPP_NO_EXCEPTIONS
3372    try {
3373#endif
3374    for (; __idx != __last; ++__idx)
3375        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3376#ifndef _LIBCPP_NO_EXCEPTIONS
3377    } catch (...) {
3378        _VSTD::destroy(__first, __idx);
3379        throw;
3380    }
3381#endif
3382}
3383
3384template <class _ForwardIterator, class _Size>
3385inline _LIBCPP_INLINE_VISIBILITY
3386_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
3387    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3388    auto __idx = __first;
3389#ifndef _LIBCPP_NO_EXCEPTIONS
3390    try {
3391#endif
3392    for (; __n > 0; (void)++__idx, --__n)
3393        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3394    return __idx;
3395#ifndef _LIBCPP_NO_EXCEPTIONS
3396    } catch (...) {
3397        _VSTD::destroy(__first, __idx);
3398        throw;
3399    }
3400#endif
3401}
3402
3403
3404template <class _InputIt, class _ForwardIt>
3405inline _LIBCPP_INLINE_VISIBILITY
3406_ForwardIt uninitialized_move(_InputIt __first, _InputIt __last, _ForwardIt __first_res) {
3407    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3408    auto __idx = __first_res;
3409#ifndef _LIBCPP_NO_EXCEPTIONS
3410    try {
3411#endif
3412    for (; __first != __last; (void)++__idx, ++__first)
3413        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3414    return __idx;
3415#ifndef _LIBCPP_NO_EXCEPTIONS
3416    } catch (...) {
3417        _VSTD::destroy(__first_res, __idx);
3418        throw;
3419    }
3420#endif
3421}
3422
3423template <class _InputIt, class _Size, class _ForwardIt>
3424inline _LIBCPP_INLINE_VISIBILITY
3425pair<_InputIt, _ForwardIt>
3426uninitialized_move_n(_InputIt __first, _Size __n, _ForwardIt __first_res) {
3427    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3428    auto __idx = __first_res;
3429#ifndef _LIBCPP_NO_EXCEPTIONS
3430    try {
3431#endif
3432    for (; __n > 0; ++__idx, (void)++__first, --__n)
3433        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3434    return {__first, __idx};
3435#ifndef _LIBCPP_NO_EXCEPTIONS
3436    } catch (...) {
3437        _VSTD::destroy(__first_res, __idx);
3438        throw;
3439    }
3440#endif
3441}
3442
3443
3444#endif // _LIBCPP_STD_VER > 14
3445
3446// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
3447// should be sufficient for thread safety.
3448// See https://bugs.llvm.org/show_bug.cgi?id=22803
3449#if defined(__clang__) && __has_builtin(__atomic_add_fetch)          \
3450                       && defined(__ATOMIC_RELAXED)                  \
3451                       && defined(__ATOMIC_ACQ_REL)
3452#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3453#elif !defined(__clang__) && defined(_GNUC_VER) && _GNUC_VER >= 407
3454#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3455#endif
3456
3457template <class _Tp>
3458inline _LIBCPP_INLINE_VISIBILITY _Tp
3459__libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT
3460{
3461#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3462    return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
3463#else
3464    return __t += 1;
3465#endif
3466}
3467
3468template <class _Tp>
3469inline _LIBCPP_INLINE_VISIBILITY _Tp
3470__libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT
3471{
3472#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3473    return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
3474#else
3475    return __t -= 1;
3476#endif
3477}
3478
3479class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
3480    : public std::exception
3481{
3482public:
3483    virtual ~bad_weak_ptr() _NOEXCEPT;
3484    virtual const char* what() const  _NOEXCEPT;
3485};
3486
3487_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
3488void __throw_bad_weak_ptr()
3489{
3490#ifndef _LIBCPP_NO_EXCEPTIONS
3491    throw bad_weak_ptr();
3492#else
3493    _VSTD::abort();
3494#endif
3495}
3496
3497template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr;
3498
3499class _LIBCPP_TYPE_VIS __shared_count
3500{
3501    __shared_count(const __shared_count&);
3502    __shared_count& operator=(const __shared_count&);
3503
3504protected:
3505    long __shared_owners_;
3506    virtual ~__shared_count();
3507private:
3508    virtual void __on_zero_shared() _NOEXCEPT = 0;
3509
3510public:
3511    _LIBCPP_INLINE_VISIBILITY
3512    explicit __shared_count(long __refs = 0) _NOEXCEPT
3513        : __shared_owners_(__refs) {}
3514
3515#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3516    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3517    void __add_shared() _NOEXCEPT;
3518    bool __release_shared() _NOEXCEPT;
3519#else
3520    _LIBCPP_INLINE_VISIBILITY
3521    void __add_shared() _NOEXCEPT {
3522      __libcpp_atomic_refcount_increment(__shared_owners_);
3523    }
3524    _LIBCPP_INLINE_VISIBILITY
3525    bool __release_shared() _NOEXCEPT {
3526      if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
3527        __on_zero_shared();
3528        return true;
3529      }
3530      return false;
3531    }
3532#endif
3533    _LIBCPP_INLINE_VISIBILITY
3534    long use_count() const _NOEXCEPT {
3535        return __libcpp_relaxed_load(&__shared_owners_) + 1;
3536    }
3537};
3538
3539class _LIBCPP_TYPE_VIS __shared_weak_count
3540    : private __shared_count
3541{
3542    long __shared_weak_owners_;
3543
3544public:
3545    _LIBCPP_INLINE_VISIBILITY
3546    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
3547        : __shared_count(__refs),
3548          __shared_weak_owners_(__refs) {}
3549protected:
3550    virtual ~__shared_weak_count();
3551
3552public:
3553#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3554    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3555    void __add_shared() _NOEXCEPT;
3556    void __add_weak() _NOEXCEPT;
3557    void __release_shared() _NOEXCEPT;
3558#else
3559    _LIBCPP_INLINE_VISIBILITY
3560    void __add_shared() _NOEXCEPT {
3561      __shared_count::__add_shared();
3562    }
3563    _LIBCPP_INLINE_VISIBILITY
3564    void __add_weak() _NOEXCEPT {
3565      __libcpp_atomic_refcount_increment(__shared_weak_owners_);
3566    }
3567    _LIBCPP_INLINE_VISIBILITY
3568    void __release_shared() _NOEXCEPT {
3569      if (__shared_count::__release_shared())
3570        __release_weak();
3571    }
3572#endif
3573    void __release_weak() _NOEXCEPT;
3574    _LIBCPP_INLINE_VISIBILITY
3575    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
3576    __shared_weak_count* lock() _NOEXCEPT;
3577
3578    // Define the function out only if we build static libc++ without RTTI.
3579    // Otherwise we may break clients who need to compile their projects with
3580    // -fno-rtti and yet link against a libc++.dylib compiled
3581    // without -fno-rtti.
3582#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
3583    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3584#endif
3585private:
3586    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
3587};
3588
3589template <class _Tp, class _Dp, class _Alloc>
3590class __shared_ptr_pointer
3591    : public __shared_weak_count
3592{
3593    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
3594public:
3595    _LIBCPP_INLINE_VISIBILITY
3596    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
3597        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
3598
3599#ifndef _LIBCPP_NO_RTTI
3600    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3601#endif
3602
3603private:
3604    virtual void __on_zero_shared() _NOEXCEPT;
3605    virtual void __on_zero_shared_weak() _NOEXCEPT;
3606};
3607
3608#ifndef _LIBCPP_NO_RTTI
3609
3610template <class _Tp, class _Dp, class _Alloc>
3611const void*
3612__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
3613{
3614    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr;
3615}
3616
3617#endif  // _LIBCPP_NO_RTTI
3618
3619template <class _Tp, class _Dp, class _Alloc>
3620void
3621__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
3622{
3623    __data_.first().second()(__data_.first().first());
3624    __data_.first().second().~_Dp();
3625}
3626
3627template <class _Tp, class _Dp, class _Alloc>
3628void
3629__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3630{
3631    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
3632    typedef allocator_traits<_Al> _ATraits;
3633    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3634
3635    _Al __a(__data_.second());
3636    __data_.second().~_Alloc();
3637    __a.deallocate(_PTraits::pointer_to(*this), 1);
3638}
3639
3640template <class _Tp, class _Alloc>
3641class __shared_ptr_emplace
3642    : public __shared_weak_count
3643{
3644    __compressed_pair<_Alloc, _Tp> __data_;
3645public:
3646#ifndef _LIBCPP_HAS_NO_VARIADICS
3647
3648    _LIBCPP_INLINE_VISIBILITY
3649    __shared_ptr_emplace(_Alloc __a)
3650        :  __data_(_VSTD::move(__a)) {}
3651
3652    template <class ..._Args>
3653        _LIBCPP_INLINE_VISIBILITY
3654        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
3655            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
3656                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
3657
3658#else  // _LIBCPP_HAS_NO_VARIADICS
3659
3660    _LIBCPP_INLINE_VISIBILITY
3661    __shared_ptr_emplace(_Alloc __a)
3662        :  __data_(__a) {}
3663
3664    template <class _A0>
3665        _LIBCPP_INLINE_VISIBILITY
3666        __shared_ptr_emplace(_Alloc __a, _A0& __a0)
3667            :  __data_(__a, _Tp(__a0)) {}
3668
3669    template <class _A0, class _A1>
3670        _LIBCPP_INLINE_VISIBILITY
3671        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
3672            :  __data_(__a, _Tp(__a0, __a1)) {}
3673
3674    template <class _A0, class _A1, class _A2>
3675        _LIBCPP_INLINE_VISIBILITY
3676        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
3677            :  __data_(__a, _Tp(__a0, __a1, __a2)) {}
3678
3679#endif  // _LIBCPP_HAS_NO_VARIADICS
3680
3681private:
3682    virtual void __on_zero_shared() _NOEXCEPT;
3683    virtual void __on_zero_shared_weak() _NOEXCEPT;
3684public:
3685    _LIBCPP_INLINE_VISIBILITY
3686    _Tp* get() _NOEXCEPT {return _VSTD::addressof(__data_.second());}
3687};
3688
3689template <class _Tp, class _Alloc>
3690void
3691__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
3692{
3693    __data_.second().~_Tp();
3694}
3695
3696template <class _Tp, class _Alloc>
3697void
3698__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3699{
3700    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
3701    typedef allocator_traits<_Al> _ATraits;
3702    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3703    _Al __a(__data_.first());
3704    __data_.first().~_Alloc();
3705    __a.deallocate(_PTraits::pointer_to(*this), 1);
3706}
3707
3708struct __shared_ptr_dummy_rebind_allocator_type;
3709template <>
3710class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type>
3711{
3712public:
3713    template <class _Other>
3714    struct rebind
3715    {
3716        typedef allocator<_Other> other;
3717    };
3718};
3719
3720template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
3721
3722template<class _Tp>
3723class _LIBCPP_TEMPLATE_VIS shared_ptr
3724{
3725public:
3726    typedef _Tp element_type;
3727
3728#if _LIBCPP_STD_VER > 14
3729    typedef weak_ptr<_Tp> weak_type;
3730#endif
3731private:
3732    element_type*      __ptr_;
3733    __shared_weak_count* __cntrl_;
3734
3735    struct __nat {int __for_bool_;};
3736public:
3737    _LIBCPP_INLINE_VISIBILITY
3738    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
3739    _LIBCPP_INLINE_VISIBILITY
3740    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
3741    template<class _Yp>
3742        explicit shared_ptr(_Yp* __p,
3743                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3744    template<class _Yp, class _Dp>
3745        shared_ptr(_Yp* __p, _Dp __d,
3746                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3747    template<class _Yp, class _Dp, class _Alloc>
3748        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3749                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3750    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
3751    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
3752    template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
3753    _LIBCPP_INLINE_VISIBILITY
3754    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
3755    template<class _Yp>
3756        _LIBCPP_INLINE_VISIBILITY
3757        shared_ptr(const shared_ptr<_Yp>& __r,
3758                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
3759                       _NOEXCEPT;
3760#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3761    _LIBCPP_INLINE_VISIBILITY
3762    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
3763    template<class _Yp> _LIBCPP_INLINE_VISIBILITY  shared_ptr(shared_ptr<_Yp>&& __r,
3764                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat())
3765                       _NOEXCEPT;
3766#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3767    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
3768                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type= __nat());
3769#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3770#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3771    template<class _Yp>
3772        shared_ptr(auto_ptr<_Yp>&& __r,
3773                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3774#else
3775    template<class _Yp>
3776        shared_ptr(auto_ptr<_Yp> __r,
3777                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3778#endif
3779#endif
3780#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3781    template <class _Yp, class _Dp>
3782        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3783                   typename enable_if
3784                   <
3785                       !is_lvalue_reference<_Dp>::value &&
3786                       !is_array<_Yp>::value &&
3787                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3788                       __nat
3789                   >::type = __nat());
3790    template <class _Yp, class _Dp>
3791        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3792                   typename enable_if
3793                   <
3794                       is_lvalue_reference<_Dp>::value &&
3795                       !is_array<_Yp>::value &&
3796                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3797                       __nat
3798                   >::type = __nat());
3799#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3800    template <class _Yp, class _Dp>
3801        shared_ptr(unique_ptr<_Yp, _Dp>,
3802                   typename enable_if
3803                   <
3804                       !is_lvalue_reference<_Dp>::value &&
3805                       !is_array<_Yp>::value &&
3806                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3807                       __nat
3808                   >::type = __nat());
3809    template <class _Yp, class _Dp>
3810        shared_ptr(unique_ptr<_Yp, _Dp>,
3811                   typename enable_if
3812                   <
3813                       is_lvalue_reference<_Dp>::value &&
3814                       !is_array<_Yp>::value &&
3815                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3816                       __nat
3817                   >::type = __nat());
3818#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3819
3820    ~shared_ptr();
3821
3822    _LIBCPP_INLINE_VISIBILITY
3823    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
3824    template<class _Yp>
3825        typename enable_if
3826        <
3827            is_convertible<_Yp*, element_type*>::value,
3828            shared_ptr&
3829        >::type
3830        _LIBCPP_INLINE_VISIBILITY
3831        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
3832#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3833    _LIBCPP_INLINE_VISIBILITY
3834    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
3835    template<class _Yp>
3836        typename enable_if
3837        <
3838            is_convertible<_Yp*, element_type*>::value,
3839            shared_ptr<_Tp>&
3840        >::type
3841        _LIBCPP_INLINE_VISIBILITY
3842        operator=(shared_ptr<_Yp>&& __r);
3843#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3844    template<class _Yp>
3845        _LIBCPP_INLINE_VISIBILITY
3846        typename enable_if
3847        <
3848            !is_array<_Yp>::value &&
3849            is_convertible<_Yp*, element_type*>::value,
3850            shared_ptr
3851        >::type&
3852        operator=(auto_ptr<_Yp>&& __r);
3853#endif
3854#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3855#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3856    template<class _Yp>
3857        _LIBCPP_INLINE_VISIBILITY
3858        typename enable_if
3859        <
3860            !is_array<_Yp>::value &&
3861            is_convertible<_Yp*, element_type*>::value,
3862            shared_ptr&
3863        >::type
3864        operator=(auto_ptr<_Yp> __r);
3865#endif
3866#endif
3867    template <class _Yp, class _Dp>
3868        typename enable_if
3869        <
3870            !is_array<_Yp>::value &&
3871            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3872            shared_ptr&
3873        >::type
3874#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3875        _LIBCPP_INLINE_VISIBILITY
3876        operator=(unique_ptr<_Yp, _Dp>&& __r);
3877#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3878        _LIBCPP_INLINE_VISIBILITY
3879        operator=(unique_ptr<_Yp, _Dp> __r);
3880#endif
3881
3882    _LIBCPP_INLINE_VISIBILITY
3883    void swap(shared_ptr& __r) _NOEXCEPT;
3884    _LIBCPP_INLINE_VISIBILITY
3885    void reset() _NOEXCEPT;
3886    template<class _Yp>
3887        typename enable_if
3888        <
3889            is_convertible<_Yp*, element_type*>::value,
3890            void
3891        >::type
3892        _LIBCPP_INLINE_VISIBILITY
3893        reset(_Yp* __p);
3894    template<class _Yp, class _Dp>
3895        typename enable_if
3896        <
3897            is_convertible<_Yp*, element_type*>::value,
3898            void
3899        >::type
3900        _LIBCPP_INLINE_VISIBILITY
3901        reset(_Yp* __p, _Dp __d);
3902    template<class _Yp, class _Dp, class _Alloc>
3903        typename enable_if
3904        <
3905            is_convertible<_Yp*, element_type*>::value,
3906            void
3907        >::type
3908        _LIBCPP_INLINE_VISIBILITY
3909        reset(_Yp* __p, _Dp __d, _Alloc __a);
3910
3911    _LIBCPP_INLINE_VISIBILITY
3912    element_type* get() const _NOEXCEPT {return __ptr_;}
3913    _LIBCPP_INLINE_VISIBILITY
3914    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
3915        {return *__ptr_;}
3916    _LIBCPP_INLINE_VISIBILITY
3917    element_type* operator->() const _NOEXCEPT {return __ptr_;}
3918    _LIBCPP_INLINE_VISIBILITY
3919    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
3920    _LIBCPP_INLINE_VISIBILITY
3921    bool unique() const _NOEXCEPT {return use_count() == 1;}
3922    _LIBCPP_INLINE_VISIBILITY
3923    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
3924    template <class _Up>
3925        _LIBCPP_INLINE_VISIBILITY
3926        bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT
3927        {return __cntrl_ < __p.__cntrl_;}
3928    template <class _Up>
3929        _LIBCPP_INLINE_VISIBILITY
3930        bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT
3931        {return __cntrl_ < __p.__cntrl_;}
3932    _LIBCPP_INLINE_VISIBILITY
3933    bool
3934    __owner_equivalent(const shared_ptr& __p) const
3935        {return __cntrl_ == __p.__cntrl_;}
3936
3937#ifndef _LIBCPP_NO_RTTI
3938    template <class _Dp>
3939        _LIBCPP_INLINE_VISIBILITY
3940        _Dp* __get_deleter() const _NOEXCEPT
3941            {return static_cast<_Dp*>(__cntrl_
3942                    ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp)))
3943                      : nullptr);}
3944#endif  // _LIBCPP_NO_RTTI
3945
3946#ifndef _LIBCPP_HAS_NO_VARIADICS
3947
3948    template<class ..._Args>
3949        static
3950        shared_ptr<_Tp>
3951        make_shared(_Args&& ...__args);
3952
3953    template<class _Alloc, class ..._Args>
3954        static
3955        shared_ptr<_Tp>
3956        allocate_shared(const _Alloc& __a, _Args&& ...__args);
3957
3958#else  // _LIBCPP_HAS_NO_VARIADICS
3959
3960    static shared_ptr<_Tp> make_shared();
3961
3962    template<class _A0>
3963        static shared_ptr<_Tp> make_shared(_A0&);
3964
3965    template<class _A0, class _A1>
3966        static shared_ptr<_Tp> make_shared(_A0&, _A1&);
3967
3968    template<class _A0, class _A1, class _A2>
3969        static shared_ptr<_Tp> make_shared(_A0&, _A1&, _A2&);
3970
3971    template<class _Alloc>
3972        static shared_ptr<_Tp>
3973        allocate_shared(const _Alloc& __a);
3974
3975    template<class _Alloc, class _A0>
3976        static shared_ptr<_Tp>
3977        allocate_shared(const _Alloc& __a, _A0& __a0);
3978
3979    template<class _Alloc, class _A0, class _A1>
3980        static shared_ptr<_Tp>
3981        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1);
3982
3983    template<class _Alloc, class _A0, class _A1, class _A2>
3984        static shared_ptr<_Tp>
3985        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2);
3986
3987#endif  // _LIBCPP_HAS_NO_VARIADICS
3988
3989private:
3990    template <class _Yp, bool = is_function<_Yp>::value>
3991        struct __shared_ptr_default_allocator
3992        {
3993            typedef allocator<_Yp> type;
3994        };
3995
3996    template <class _Yp>
3997        struct __shared_ptr_default_allocator<_Yp, true>
3998        {
3999            typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
4000        };
4001
4002    template <class _Yp, class _OrigPtr>
4003        _LIBCPP_INLINE_VISIBILITY
4004        typename enable_if<is_convertible<_OrigPtr*,
4005                                          const enable_shared_from_this<_Yp>*
4006        >::value,
4007            void>::type
4008        __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
4009                           _OrigPtr* __ptr) _NOEXCEPT
4010        {
4011            typedef typename remove_cv<_Yp>::type _RawYp;
4012            if (__e && __e->__weak_this_.expired())
4013            {
4014                __e->__weak_this_ = shared_ptr<_RawYp>(*this,
4015                    const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
4016            }
4017        }
4018
4019    _LIBCPP_INLINE_VISIBILITY void __enable_weak_this(...) _NOEXCEPT {}
4020
4021    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
4022    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
4023};
4024
4025
4026template<class _Tp>
4027inline
4028_LIBCPP_CONSTEXPR
4029shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
4030    : __ptr_(0),
4031      __cntrl_(0)
4032{
4033}
4034
4035template<class _Tp>
4036inline
4037_LIBCPP_CONSTEXPR
4038shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
4039    : __ptr_(0),
4040      __cntrl_(0)
4041{
4042}
4043
4044template<class _Tp>
4045template<class _Yp>
4046shared_ptr<_Tp>::shared_ptr(_Yp* __p,
4047                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4048    : __ptr_(__p)
4049{
4050    unique_ptr<_Yp> __hold(__p);
4051    typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4052    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, _AllocT > _CntrlBlk;
4053    __cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), _AllocT());
4054    __hold.release();
4055    __enable_weak_this(__p, __p);
4056}
4057
4058template<class _Tp>
4059template<class _Yp, class _Dp>
4060shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
4061                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4062    : __ptr_(__p)
4063{
4064#ifndef _LIBCPP_NO_EXCEPTIONS
4065    try
4066    {
4067#endif  // _LIBCPP_NO_EXCEPTIONS
4068        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4069        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
4070        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
4071        __enable_weak_this(__p, __p);
4072#ifndef _LIBCPP_NO_EXCEPTIONS
4073    }
4074    catch (...)
4075    {
4076        __d(__p);
4077        throw;
4078    }
4079#endif  // _LIBCPP_NO_EXCEPTIONS
4080}
4081
4082template<class _Tp>
4083template<class _Dp>
4084shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
4085    : __ptr_(0)
4086{
4087#ifndef _LIBCPP_NO_EXCEPTIONS
4088    try
4089    {
4090#endif  // _LIBCPP_NO_EXCEPTIONS
4091        typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
4092        typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
4093        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
4094#ifndef _LIBCPP_NO_EXCEPTIONS
4095    }
4096    catch (...)
4097    {
4098        __d(__p);
4099        throw;
4100    }
4101#endif  // _LIBCPP_NO_EXCEPTIONS
4102}
4103
4104template<class _Tp>
4105template<class _Yp, class _Dp, class _Alloc>
4106shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
4107                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4108    : __ptr_(__p)
4109{
4110#ifndef _LIBCPP_NO_EXCEPTIONS
4111    try
4112    {
4113#endif  // _LIBCPP_NO_EXCEPTIONS
4114        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
4115        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4116        typedef __allocator_destructor<_A2> _D2;
4117        _A2 __a2(__a);
4118        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4119        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4120            _CntrlBlk(__p, __d, __a);
4121        __cntrl_ = _VSTD::addressof(*__hold2.release());
4122        __enable_weak_this(__p, __p);
4123#ifndef _LIBCPP_NO_EXCEPTIONS
4124    }
4125    catch (...)
4126    {
4127        __d(__p);
4128        throw;
4129    }
4130#endif  // _LIBCPP_NO_EXCEPTIONS
4131}
4132
4133template<class _Tp>
4134template<class _Dp, class _Alloc>
4135shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
4136    : __ptr_(0)
4137{
4138#ifndef _LIBCPP_NO_EXCEPTIONS
4139    try
4140    {
4141#endif  // _LIBCPP_NO_EXCEPTIONS
4142        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
4143        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4144        typedef __allocator_destructor<_A2> _D2;
4145        _A2 __a2(__a);
4146        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4147        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4148            _CntrlBlk(__p, __d, __a);
4149        __cntrl_ = _VSTD::addressof(*__hold2.release());
4150#ifndef _LIBCPP_NO_EXCEPTIONS
4151    }
4152    catch (...)
4153    {
4154        __d(__p);
4155        throw;
4156    }
4157#endif  // _LIBCPP_NO_EXCEPTIONS
4158}
4159
4160template<class _Tp>
4161template<class _Yp>
4162inline
4163shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
4164    : __ptr_(__p),
4165      __cntrl_(__r.__cntrl_)
4166{
4167    if (__cntrl_)
4168        __cntrl_->__add_shared();
4169}
4170
4171template<class _Tp>
4172inline
4173shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
4174    : __ptr_(__r.__ptr_),
4175      __cntrl_(__r.__cntrl_)
4176{
4177    if (__cntrl_)
4178        __cntrl_->__add_shared();
4179}
4180
4181template<class _Tp>
4182template<class _Yp>
4183inline
4184shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
4185                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4186         _NOEXCEPT
4187    : __ptr_(__r.__ptr_),
4188      __cntrl_(__r.__cntrl_)
4189{
4190    if (__cntrl_)
4191        __cntrl_->__add_shared();
4192}
4193
4194#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4195
4196template<class _Tp>
4197inline
4198shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
4199    : __ptr_(__r.__ptr_),
4200      __cntrl_(__r.__cntrl_)
4201{
4202    __r.__ptr_ = 0;
4203    __r.__cntrl_ = 0;
4204}
4205
4206template<class _Tp>
4207template<class _Yp>
4208inline
4209shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
4210                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4211         _NOEXCEPT
4212    : __ptr_(__r.__ptr_),
4213      __cntrl_(__r.__cntrl_)
4214{
4215    __r.__ptr_ = 0;
4216    __r.__cntrl_ = 0;
4217}
4218
4219#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4220
4221#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4222template<class _Tp>
4223template<class _Yp>
4224#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4225shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
4226#else
4227shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp> __r,
4228#endif
4229                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4230    : __ptr_(__r.get())
4231{
4232    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
4233    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
4234    __enable_weak_this(__r.get(), __r.get());
4235    __r.release();
4236}
4237#endif
4238
4239template<class _Tp>
4240template <class _Yp, class _Dp>
4241#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4242shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4243#else
4244shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4245#endif
4246                            typename enable_if
4247                            <
4248                                !is_lvalue_reference<_Dp>::value &&
4249                                !is_array<_Yp>::value &&
4250                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4251                                __nat
4252                            >::type)
4253    : __ptr_(__r.get())
4254{
4255#if _LIBCPP_STD_VER > 11
4256    if (__ptr_ == nullptr)
4257        __cntrl_ = nullptr;
4258    else
4259#endif
4260    {
4261        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4262        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
4263        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), _AllocT());
4264        __enable_weak_this(__r.get(), __r.get());
4265    }
4266    __r.release();
4267}
4268
4269template<class _Tp>
4270template <class _Yp, class _Dp>
4271#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4272shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4273#else
4274shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4275#endif
4276                            typename enable_if
4277                            <
4278                                is_lvalue_reference<_Dp>::value &&
4279                                !is_array<_Yp>::value &&
4280                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4281                                __nat
4282                            >::type)
4283    : __ptr_(__r.get())
4284{
4285#if _LIBCPP_STD_VER > 11
4286    if (__ptr_ == nullptr)
4287        __cntrl_ = nullptr;
4288    else
4289#endif
4290    {
4291        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
4292        typedef __shared_ptr_pointer<_Yp*,
4293                                     reference_wrapper<typename remove_reference<_Dp>::type>,
4294                                     _AllocT > _CntrlBlk;
4295        __cntrl_ = new _CntrlBlk(__r.get(), ref(__r.get_deleter()), _AllocT());
4296        __enable_weak_this(__r.get(), __r.get());
4297    }
4298    __r.release();
4299}
4300
4301#ifndef _LIBCPP_HAS_NO_VARIADICS
4302
4303template<class _Tp>
4304template<class ..._Args>
4305shared_ptr<_Tp>
4306shared_ptr<_Tp>::make_shared(_Args&& ...__args)
4307{
4308    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in make_shared" );
4309    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4310    typedef allocator<_CntrlBlk> _A2;
4311    typedef __allocator_destructor<_A2> _D2;
4312    _A2 __a2;
4313    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4314    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
4315    shared_ptr<_Tp> __r;
4316    __r.__ptr_ = __hold2.get()->get();
4317    __r.__cntrl_ = __hold2.release();
4318    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4319    return __r;
4320}
4321
4322template<class _Tp>
4323template<class _Alloc, class ..._Args>
4324shared_ptr<_Tp>
4325shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _Args&& ...__args)
4326{
4327    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in allocate_shared" );
4328    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4329    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4330    typedef __allocator_destructor<_A2> _D2;
4331    _A2 __a2(__a);
4332    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4333    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4334        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
4335    shared_ptr<_Tp> __r;
4336    __r.__ptr_ = __hold2.get()->get();
4337    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4338    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4339    return __r;
4340}
4341
4342#else  // _LIBCPP_HAS_NO_VARIADICS
4343
4344template<class _Tp>
4345shared_ptr<_Tp>
4346shared_ptr<_Tp>::make_shared()
4347{
4348    static_assert((is_constructible<_Tp>::value), "Can't construct object in make_shared" );
4349    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4350    typedef allocator<_CntrlBlk> _Alloc2;
4351    typedef __allocator_destructor<_Alloc2> _D2;
4352    _Alloc2 __alloc2;
4353    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4354    ::new(__hold2.get()) _CntrlBlk(__alloc2);
4355    shared_ptr<_Tp> __r;
4356    __r.__ptr_ = __hold2.get()->get();
4357    __r.__cntrl_ = __hold2.release();
4358    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4359    return __r;
4360}
4361
4362template<class _Tp>
4363template<class _A0>
4364shared_ptr<_Tp>
4365shared_ptr<_Tp>::make_shared(_A0& __a0)
4366{
4367    static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in make_shared" );
4368    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4369    typedef allocator<_CntrlBlk> _Alloc2;
4370    typedef __allocator_destructor<_Alloc2> _D2;
4371    _Alloc2 __alloc2;
4372    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4373    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0);
4374    shared_ptr<_Tp> __r;
4375    __r.__ptr_ = __hold2.get()->get();
4376    __r.__cntrl_ = __hold2.release();
4377    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4378    return __r;
4379}
4380
4381template<class _Tp>
4382template<class _A0, class _A1>
4383shared_ptr<_Tp>
4384shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1)
4385{
4386    static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in make_shared" );
4387    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4388    typedef allocator<_CntrlBlk> _Alloc2;
4389    typedef __allocator_destructor<_Alloc2> _D2;
4390    _Alloc2 __alloc2;
4391    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4392    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1);
4393    shared_ptr<_Tp> __r;
4394    __r.__ptr_ = __hold2.get()->get();
4395    __r.__cntrl_ = __hold2.release();
4396    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4397    return __r;
4398}
4399
4400template<class _Tp>
4401template<class _A0, class _A1, class _A2>
4402shared_ptr<_Tp>
4403shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
4404{
4405    static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in make_shared" );
4406    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4407    typedef allocator<_CntrlBlk> _Alloc2;
4408    typedef __allocator_destructor<_Alloc2> _D2;
4409    _Alloc2 __alloc2;
4410    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4411    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1, __a2);
4412    shared_ptr<_Tp> __r;
4413    __r.__ptr_ = __hold2.get()->get();
4414    __r.__cntrl_ = __hold2.release();
4415    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4416    return __r;
4417}
4418
4419template<class _Tp>
4420template<class _Alloc>
4421shared_ptr<_Tp>
4422shared_ptr<_Tp>::allocate_shared(const _Alloc& __a)
4423{
4424    static_assert((is_constructible<_Tp>::value), "Can't construct object in allocate_shared" );
4425    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4426    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4427    typedef __allocator_destructor<_Alloc2> _D2;
4428    _Alloc2 __alloc2(__a);
4429    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4430    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4431        _CntrlBlk(__a);
4432    shared_ptr<_Tp> __r;
4433    __r.__ptr_ = __hold2.get()->get();
4434    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4435    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4436    return __r;
4437}
4438
4439template<class _Tp>
4440template<class _Alloc, class _A0>
4441shared_ptr<_Tp>
4442shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0)
4443{
4444    static_assert((is_constructible<_Tp, _A0>::value), "Can't construct object in allocate_shared" );
4445    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4446    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4447    typedef __allocator_destructor<_Alloc2> _D2;
4448    _Alloc2 __alloc2(__a);
4449    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4450    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4451        _CntrlBlk(__a, __a0);
4452    shared_ptr<_Tp> __r;
4453    __r.__ptr_ = __hold2.get()->get();
4454    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4455    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4456    return __r;
4457}
4458
4459template<class _Tp>
4460template<class _Alloc, class _A0, class _A1>
4461shared_ptr<_Tp>
4462shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
4463{
4464    static_assert((is_constructible<_Tp, _A0, _A1>::value), "Can't construct object in allocate_shared" );
4465    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4466    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4467    typedef __allocator_destructor<_Alloc2> _D2;
4468    _Alloc2 __alloc2(__a);
4469    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4470    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4471        _CntrlBlk(__a, __a0, __a1);
4472    shared_ptr<_Tp> __r;
4473    __r.__ptr_ = __hold2.get()->get();
4474    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4475    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4476    return __r;
4477}
4478
4479template<class _Tp>
4480template<class _Alloc, class _A0, class _A1, class _A2>
4481shared_ptr<_Tp>
4482shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
4483{
4484    static_assert((is_constructible<_Tp, _A0, _A1, _A2>::value), "Can't construct object in allocate_shared" );
4485    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4486    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4487    typedef __allocator_destructor<_Alloc2> _D2;
4488    _Alloc2 __alloc2(__a);
4489    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4490    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4491        _CntrlBlk(__a, __a0, __a1, __a2);
4492    shared_ptr<_Tp> __r;
4493    __r.__ptr_ = __hold2.get()->get();
4494    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4495    __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
4496    return __r;
4497}
4498
4499#endif  // _LIBCPP_HAS_NO_VARIADICS
4500
4501template<class _Tp>
4502shared_ptr<_Tp>::~shared_ptr()
4503{
4504    if (__cntrl_)
4505        __cntrl_->__release_shared();
4506}
4507
4508template<class _Tp>
4509inline
4510shared_ptr<_Tp>&
4511shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
4512{
4513    shared_ptr(__r).swap(*this);
4514    return *this;
4515}
4516
4517template<class _Tp>
4518template<class _Yp>
4519inline
4520typename enable_if
4521<
4522    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4523    shared_ptr<_Tp>&
4524>::type
4525shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
4526{
4527    shared_ptr(__r).swap(*this);
4528    return *this;
4529}
4530
4531#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4532
4533template<class _Tp>
4534inline
4535shared_ptr<_Tp>&
4536shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
4537{
4538    shared_ptr(_VSTD::move(__r)).swap(*this);
4539    return *this;
4540}
4541
4542template<class _Tp>
4543template<class _Yp>
4544inline
4545typename enable_if
4546<
4547    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4548    shared_ptr<_Tp>&
4549>::type
4550shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
4551{
4552    shared_ptr(_VSTD::move(__r)).swap(*this);
4553    return *this;
4554}
4555
4556#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4557template<class _Tp>
4558template<class _Yp>
4559inline
4560typename enable_if
4561<
4562    !is_array<_Yp>::value &&
4563    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4564    shared_ptr<_Tp>
4565>::type&
4566shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
4567{
4568    shared_ptr(_VSTD::move(__r)).swap(*this);
4569    return *this;
4570}
4571#endif
4572
4573template<class _Tp>
4574template <class _Yp, class _Dp>
4575inline
4576typename enable_if
4577<
4578    !is_array<_Yp>::value &&
4579    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4580                   typename shared_ptr<_Tp>::element_type*>::value,
4581    shared_ptr<_Tp>&
4582>::type
4583shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
4584{
4585    shared_ptr(_VSTD::move(__r)).swap(*this);
4586    return *this;
4587}
4588
4589#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4590
4591#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
4592template<class _Tp>
4593template<class _Yp>
4594inline _LIBCPP_INLINE_VISIBILITY
4595typename enable_if
4596<
4597    !is_array<_Yp>::value &&
4598    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4599    shared_ptr<_Tp>&
4600>::type
4601shared_ptr<_Tp>::operator=(auto_ptr<_Yp> __r)
4602{
4603    shared_ptr(__r).swap(*this);
4604    return *this;
4605}
4606#endif
4607
4608template<class _Tp>
4609template <class _Yp, class _Dp>
4610inline _LIBCPP_INLINE_VISIBILITY
4611typename enable_if
4612<
4613    !is_array<_Yp>::value &&
4614    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4615                   typename shared_ptr<_Tp>::element_type*>::value,
4616    shared_ptr<_Tp>&
4617>::type
4618shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp> __r)
4619{
4620    shared_ptr(_VSTD::move(__r)).swap(*this);
4621    return *this;
4622}
4623
4624#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4625
4626template<class _Tp>
4627inline
4628void
4629shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
4630{
4631    _VSTD::swap(__ptr_, __r.__ptr_);
4632    _VSTD::swap(__cntrl_, __r.__cntrl_);
4633}
4634
4635template<class _Tp>
4636inline
4637void
4638shared_ptr<_Tp>::reset() _NOEXCEPT
4639{
4640    shared_ptr().swap(*this);
4641}
4642
4643template<class _Tp>
4644template<class _Yp>
4645inline
4646typename enable_if
4647<
4648    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4649    void
4650>::type
4651shared_ptr<_Tp>::reset(_Yp* __p)
4652{
4653    shared_ptr(__p).swap(*this);
4654}
4655
4656template<class _Tp>
4657template<class _Yp, class _Dp>
4658inline
4659typename enable_if
4660<
4661    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4662    void
4663>::type
4664shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
4665{
4666    shared_ptr(__p, __d).swap(*this);
4667}
4668
4669template<class _Tp>
4670template<class _Yp, class _Dp, class _Alloc>
4671inline
4672typename enable_if
4673<
4674    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
4675    void
4676>::type
4677shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
4678{
4679    shared_ptr(__p, __d, __a).swap(*this);
4680}
4681
4682#ifndef _LIBCPP_HAS_NO_VARIADICS
4683
4684template<class _Tp, class ..._Args>
4685inline _LIBCPP_INLINE_VISIBILITY
4686typename enable_if
4687<
4688    !is_array<_Tp>::value,
4689    shared_ptr<_Tp>
4690>::type
4691make_shared(_Args&& ...__args)
4692{
4693    return shared_ptr<_Tp>::make_shared(_VSTD::forward<_Args>(__args)...);
4694}
4695
4696template<class _Tp, class _Alloc, class ..._Args>
4697inline _LIBCPP_INLINE_VISIBILITY
4698typename enable_if
4699<
4700    !is_array<_Tp>::value,
4701    shared_ptr<_Tp>
4702>::type
4703allocate_shared(const _Alloc& __a, _Args&& ...__args)
4704{
4705    return shared_ptr<_Tp>::allocate_shared(__a, _VSTD::forward<_Args>(__args)...);
4706}
4707
4708#else  // _LIBCPP_HAS_NO_VARIADICS
4709
4710template<class _Tp>
4711inline _LIBCPP_INLINE_VISIBILITY
4712shared_ptr<_Tp>
4713make_shared()
4714{
4715    return shared_ptr<_Tp>::make_shared();
4716}
4717
4718template<class _Tp, class _A0>
4719inline _LIBCPP_INLINE_VISIBILITY
4720shared_ptr<_Tp>
4721make_shared(_A0& __a0)
4722{
4723    return shared_ptr<_Tp>::make_shared(__a0);
4724}
4725
4726template<class _Tp, class _A0, class _A1>
4727inline _LIBCPP_INLINE_VISIBILITY
4728shared_ptr<_Tp>
4729make_shared(_A0& __a0, _A1& __a1)
4730{
4731    return shared_ptr<_Tp>::make_shared(__a0, __a1);
4732}
4733
4734template<class _Tp, class _A0, class _A1, class _A2>
4735inline _LIBCPP_INLINE_VISIBILITY
4736shared_ptr<_Tp>
4737make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
4738{
4739    return shared_ptr<_Tp>::make_shared(__a0, __a1, __a2);
4740}
4741
4742template<class _Tp, class _Alloc>
4743inline _LIBCPP_INLINE_VISIBILITY
4744shared_ptr<_Tp>
4745allocate_shared(const _Alloc& __a)
4746{
4747    return shared_ptr<_Tp>::allocate_shared(__a);
4748}
4749
4750template<class _Tp, class _Alloc, class _A0>
4751inline _LIBCPP_INLINE_VISIBILITY
4752shared_ptr<_Tp>
4753allocate_shared(const _Alloc& __a, _A0& __a0)
4754{
4755    return shared_ptr<_Tp>::allocate_shared(__a, __a0);
4756}
4757
4758template<class _Tp, class _Alloc, class _A0, class _A1>
4759inline _LIBCPP_INLINE_VISIBILITY
4760shared_ptr<_Tp>
4761allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
4762{
4763    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1);
4764}
4765
4766template<class _Tp, class _Alloc, class _A0, class _A1, class _A2>
4767inline _LIBCPP_INLINE_VISIBILITY
4768shared_ptr<_Tp>
4769allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
4770{
4771    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1, __a2);
4772}
4773
4774#endif  // _LIBCPP_HAS_NO_VARIADICS
4775
4776template<class _Tp, class _Up>
4777inline _LIBCPP_INLINE_VISIBILITY
4778bool
4779operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4780{
4781    return __x.get() == __y.get();
4782}
4783
4784template<class _Tp, class _Up>
4785inline _LIBCPP_INLINE_VISIBILITY
4786bool
4787operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4788{
4789    return !(__x == __y);
4790}
4791
4792template<class _Tp, class _Up>
4793inline _LIBCPP_INLINE_VISIBILITY
4794bool
4795operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4796{
4797#if _LIBCPP_STD_VER <= 11
4798    typedef typename common_type<_Tp*, _Up*>::type _Vp;
4799    return less<_Vp>()(__x.get(), __y.get());
4800#else
4801    return less<>()(__x.get(), __y.get());
4802#endif
4803
4804}
4805
4806template<class _Tp, class _Up>
4807inline _LIBCPP_INLINE_VISIBILITY
4808bool
4809operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4810{
4811    return __y < __x;
4812}
4813
4814template<class _Tp, class _Up>
4815inline _LIBCPP_INLINE_VISIBILITY
4816bool
4817operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4818{
4819    return !(__y < __x);
4820}
4821
4822template<class _Tp, class _Up>
4823inline _LIBCPP_INLINE_VISIBILITY
4824bool
4825operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4826{
4827    return !(__x < __y);
4828}
4829
4830template<class _Tp>
4831inline _LIBCPP_INLINE_VISIBILITY
4832bool
4833operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4834{
4835    return !__x;
4836}
4837
4838template<class _Tp>
4839inline _LIBCPP_INLINE_VISIBILITY
4840bool
4841operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4842{
4843    return !__x;
4844}
4845
4846template<class _Tp>
4847inline _LIBCPP_INLINE_VISIBILITY
4848bool
4849operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4850{
4851    return static_cast<bool>(__x);
4852}
4853
4854template<class _Tp>
4855inline _LIBCPP_INLINE_VISIBILITY
4856bool
4857operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4858{
4859    return static_cast<bool>(__x);
4860}
4861
4862template<class _Tp>
4863inline _LIBCPP_INLINE_VISIBILITY
4864bool
4865operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4866{
4867    return less<_Tp*>()(__x.get(), nullptr);
4868}
4869
4870template<class _Tp>
4871inline _LIBCPP_INLINE_VISIBILITY
4872bool
4873operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4874{
4875    return less<_Tp*>()(nullptr, __x.get());
4876}
4877
4878template<class _Tp>
4879inline _LIBCPP_INLINE_VISIBILITY
4880bool
4881operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4882{
4883    return nullptr < __x;
4884}
4885
4886template<class _Tp>
4887inline _LIBCPP_INLINE_VISIBILITY
4888bool
4889operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4890{
4891    return __x < nullptr;
4892}
4893
4894template<class _Tp>
4895inline _LIBCPP_INLINE_VISIBILITY
4896bool
4897operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4898{
4899    return !(nullptr < __x);
4900}
4901
4902template<class _Tp>
4903inline _LIBCPP_INLINE_VISIBILITY
4904bool
4905operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4906{
4907    return !(__x < nullptr);
4908}
4909
4910template<class _Tp>
4911inline _LIBCPP_INLINE_VISIBILITY
4912bool
4913operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4914{
4915    return !(__x < nullptr);
4916}
4917
4918template<class _Tp>
4919inline _LIBCPP_INLINE_VISIBILITY
4920bool
4921operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4922{
4923    return !(nullptr < __x);
4924}
4925
4926template<class _Tp>
4927inline _LIBCPP_INLINE_VISIBILITY
4928void
4929swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
4930{
4931    __x.swap(__y);
4932}
4933
4934template<class _Tp, class _Up>
4935inline _LIBCPP_INLINE_VISIBILITY
4936typename enable_if
4937<
4938    !is_array<_Tp>::value && !is_array<_Up>::value,
4939    shared_ptr<_Tp>
4940>::type
4941static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4942{
4943    return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get()));
4944}
4945
4946template<class _Tp, class _Up>
4947inline _LIBCPP_INLINE_VISIBILITY
4948typename enable_if
4949<
4950    !is_array<_Tp>::value && !is_array<_Up>::value,
4951    shared_ptr<_Tp>
4952>::type
4953dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4954{
4955    _Tp* __p = dynamic_cast<_Tp*>(__r.get());
4956    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
4957}
4958
4959template<class _Tp, class _Up>
4960typename enable_if
4961<
4962    is_array<_Tp>::value == is_array<_Up>::value,
4963    shared_ptr<_Tp>
4964>::type
4965const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4966{
4967    typedef typename remove_extent<_Tp>::type _RTp;
4968    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
4969}
4970
4971#ifndef _LIBCPP_NO_RTTI
4972
4973template<class _Dp, class _Tp>
4974inline _LIBCPP_INLINE_VISIBILITY
4975_Dp*
4976get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
4977{
4978    return __p.template __get_deleter<_Dp>();
4979}
4980
4981#endif  // _LIBCPP_NO_RTTI
4982
4983template<class _Tp>
4984class _LIBCPP_TEMPLATE_VIS weak_ptr
4985{
4986public:
4987    typedef _Tp element_type;
4988private:
4989    element_type*        __ptr_;
4990    __shared_weak_count* __cntrl_;
4991
4992public:
4993    _LIBCPP_INLINE_VISIBILITY
4994    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
4995    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r,
4996                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4997                        _NOEXCEPT;
4998    _LIBCPP_INLINE_VISIBILITY
4999    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
5000    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r,
5001                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
5002                         _NOEXCEPT;
5003
5004#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5005    _LIBCPP_INLINE_VISIBILITY
5006    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
5007    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r,
5008                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
5009                         _NOEXCEPT;
5010#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5011    ~weak_ptr();
5012
5013    _LIBCPP_INLINE_VISIBILITY
5014    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
5015    template<class _Yp>
5016        typename enable_if
5017        <
5018            is_convertible<_Yp*, element_type*>::value,
5019            weak_ptr&
5020        >::type
5021        _LIBCPP_INLINE_VISIBILITY
5022        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
5023
5024#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5025
5026    _LIBCPP_INLINE_VISIBILITY
5027    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
5028    template<class _Yp>
5029        typename enable_if
5030        <
5031            is_convertible<_Yp*, element_type*>::value,
5032            weak_ptr&
5033        >::type
5034        _LIBCPP_INLINE_VISIBILITY
5035        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
5036
5037#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5038
5039    template<class _Yp>
5040        typename enable_if
5041        <
5042            is_convertible<_Yp*, element_type*>::value,
5043            weak_ptr&
5044        >::type
5045        _LIBCPP_INLINE_VISIBILITY
5046        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
5047
5048    _LIBCPP_INLINE_VISIBILITY
5049    void swap(weak_ptr& __r) _NOEXCEPT;
5050    _LIBCPP_INLINE_VISIBILITY
5051    void reset() _NOEXCEPT;
5052
5053    _LIBCPP_INLINE_VISIBILITY
5054    long use_count() const _NOEXCEPT
5055        {return __cntrl_ ? __cntrl_->use_count() : 0;}
5056    _LIBCPP_INLINE_VISIBILITY
5057    bool expired() const _NOEXCEPT
5058        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
5059    shared_ptr<_Tp> lock() const _NOEXCEPT;
5060    template<class _Up>
5061        _LIBCPP_INLINE_VISIBILITY
5062        bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT
5063        {return __cntrl_ < __r.__cntrl_;}
5064    template<class _Up>
5065        _LIBCPP_INLINE_VISIBILITY
5066        bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT
5067        {return __cntrl_ < __r.__cntrl_;}
5068
5069    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
5070    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
5071};
5072
5073template<class _Tp>
5074inline
5075_LIBCPP_CONSTEXPR
5076weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
5077    : __ptr_(0),
5078      __cntrl_(0)
5079{
5080}
5081
5082template<class _Tp>
5083inline
5084weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
5085    : __ptr_(__r.__ptr_),
5086      __cntrl_(__r.__cntrl_)
5087{
5088    if (__cntrl_)
5089        __cntrl_->__add_weak();
5090}
5091
5092template<class _Tp>
5093template<class _Yp>
5094inline
5095weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
5096                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5097                         _NOEXCEPT
5098    : __ptr_(__r.__ptr_),
5099      __cntrl_(__r.__cntrl_)
5100{
5101    if (__cntrl_)
5102        __cntrl_->__add_weak();
5103}
5104
5105template<class _Tp>
5106template<class _Yp>
5107inline
5108weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
5109                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5110         _NOEXCEPT
5111    : __ptr_(__r.__ptr_),
5112      __cntrl_(__r.__cntrl_)
5113{
5114    if (__cntrl_)
5115        __cntrl_->__add_weak();
5116}
5117
5118#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5119
5120template<class _Tp>
5121inline
5122weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
5123    : __ptr_(__r.__ptr_),
5124      __cntrl_(__r.__cntrl_)
5125{
5126    __r.__ptr_ = 0;
5127    __r.__cntrl_ = 0;
5128}
5129
5130template<class _Tp>
5131template<class _Yp>
5132inline
5133weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
5134                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5135         _NOEXCEPT
5136    : __ptr_(__r.__ptr_),
5137      __cntrl_(__r.__cntrl_)
5138{
5139    __r.__ptr_ = 0;
5140    __r.__cntrl_ = 0;
5141}
5142
5143#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5144
5145template<class _Tp>
5146weak_ptr<_Tp>::~weak_ptr()
5147{
5148    if (__cntrl_)
5149        __cntrl_->__release_weak();
5150}
5151
5152template<class _Tp>
5153inline
5154weak_ptr<_Tp>&
5155weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
5156{
5157    weak_ptr(__r).swap(*this);
5158    return *this;
5159}
5160
5161template<class _Tp>
5162template<class _Yp>
5163inline
5164typename enable_if
5165<
5166    is_convertible<_Yp*, _Tp*>::value,
5167    weak_ptr<_Tp>&
5168>::type
5169weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
5170{
5171    weak_ptr(__r).swap(*this);
5172    return *this;
5173}
5174
5175#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5176
5177template<class _Tp>
5178inline
5179weak_ptr<_Tp>&
5180weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
5181{
5182    weak_ptr(_VSTD::move(__r)).swap(*this);
5183    return *this;
5184}
5185
5186template<class _Tp>
5187template<class _Yp>
5188inline
5189typename enable_if
5190<
5191    is_convertible<_Yp*, _Tp*>::value,
5192    weak_ptr<_Tp>&
5193>::type
5194weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
5195{
5196    weak_ptr(_VSTD::move(__r)).swap(*this);
5197    return *this;
5198}
5199
5200#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5201
5202template<class _Tp>
5203template<class _Yp>
5204inline
5205typename enable_if
5206<
5207    is_convertible<_Yp*, _Tp*>::value,
5208    weak_ptr<_Tp>&
5209>::type
5210weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
5211{
5212    weak_ptr(__r).swap(*this);
5213    return *this;
5214}
5215
5216template<class _Tp>
5217inline
5218void
5219weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
5220{
5221    _VSTD::swap(__ptr_, __r.__ptr_);
5222    _VSTD::swap(__cntrl_, __r.__cntrl_);
5223}
5224
5225template<class _Tp>
5226inline _LIBCPP_INLINE_VISIBILITY
5227void
5228swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
5229{
5230    __x.swap(__y);
5231}
5232
5233template<class _Tp>
5234inline
5235void
5236weak_ptr<_Tp>::reset() _NOEXCEPT
5237{
5238    weak_ptr().swap(*this);
5239}
5240
5241template<class _Tp>
5242template<class _Yp>
5243shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
5244                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
5245    : __ptr_(__r.__ptr_),
5246      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
5247{
5248    if (__cntrl_ == 0)
5249        __throw_bad_weak_ptr();
5250}
5251
5252template<class _Tp>
5253shared_ptr<_Tp>
5254weak_ptr<_Tp>::lock() const _NOEXCEPT
5255{
5256    shared_ptr<_Tp> __r;
5257    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
5258    if (__r.__cntrl_)
5259        __r.__ptr_ = __ptr_;
5260    return __r;
5261}
5262
5263#if _LIBCPP_STD_VER > 14
5264template <class _Tp = void> struct owner_less;
5265#else
5266template <class _Tp> struct owner_less;
5267#endif
5268
5269template <class _Tp>
5270struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> >
5271    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
5272{
5273    typedef bool result_type;
5274    _LIBCPP_INLINE_VISIBILITY
5275    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
5276        {return __x.owner_before(__y);}
5277    _LIBCPP_INLINE_VISIBILITY
5278    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
5279        {return __x.owner_before(__y);}
5280    _LIBCPP_INLINE_VISIBILITY
5281    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
5282        {return __x.owner_before(__y);}
5283};
5284
5285template <class _Tp>
5286struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> >
5287    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
5288{
5289    typedef bool result_type;
5290    _LIBCPP_INLINE_VISIBILITY
5291    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
5292        {return __x.owner_before(__y);}
5293    _LIBCPP_INLINE_VISIBILITY
5294    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
5295        {return __x.owner_before(__y);}
5296    _LIBCPP_INLINE_VISIBILITY
5297    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
5298        {return __x.owner_before(__y);}
5299};
5300
5301#if _LIBCPP_STD_VER > 14
5302template <>
5303struct _LIBCPP_TEMPLATE_VIS owner_less<void>
5304{
5305    template <class _Tp, class _Up>
5306    _LIBCPP_INLINE_VISIBILITY
5307    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
5308        {return __x.owner_before(__y);}
5309    template <class _Tp, class _Up>
5310    _LIBCPP_INLINE_VISIBILITY
5311    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
5312        {return __x.owner_before(__y);}
5313    template <class _Tp, class _Up>
5314    _LIBCPP_INLINE_VISIBILITY
5315    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
5316        {return __x.owner_before(__y);}
5317    template <class _Tp, class _Up>
5318    _LIBCPP_INLINE_VISIBILITY
5319    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
5320        {return __x.owner_before(__y);}
5321    typedef void is_transparent;
5322};
5323#endif
5324
5325template<class _Tp>
5326class _LIBCPP_TEMPLATE_VIS enable_shared_from_this
5327{
5328    mutable weak_ptr<_Tp> __weak_this_;
5329protected:
5330    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
5331    enable_shared_from_this() _NOEXCEPT {}
5332    _LIBCPP_INLINE_VISIBILITY
5333    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
5334    _LIBCPP_INLINE_VISIBILITY
5335    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
5336        {return *this;}
5337    _LIBCPP_INLINE_VISIBILITY
5338    ~enable_shared_from_this() {}
5339public:
5340    _LIBCPP_INLINE_VISIBILITY
5341    shared_ptr<_Tp> shared_from_this()
5342        {return shared_ptr<_Tp>(__weak_this_);}
5343    _LIBCPP_INLINE_VISIBILITY
5344    shared_ptr<_Tp const> shared_from_this() const
5345        {return shared_ptr<const _Tp>(__weak_this_);}
5346
5347#if _LIBCPP_STD_VER > 14
5348    _LIBCPP_INLINE_VISIBILITY
5349    weak_ptr<_Tp> weak_from_this() _NOEXCEPT
5350       { return __weak_this_; }
5351
5352    _LIBCPP_INLINE_VISIBILITY
5353    weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT
5354        { return __weak_this_; }
5355#endif // _LIBCPP_STD_VER > 14
5356
5357    template <class _Up> friend class shared_ptr;
5358};
5359
5360template <class _Tp>
5361struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> >
5362{
5363    typedef shared_ptr<_Tp>      argument_type;
5364    typedef size_t               result_type;
5365
5366    _LIBCPP_INLINE_VISIBILITY
5367    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
5368    {
5369        return hash<_Tp*>()(__ptr.get());
5370    }
5371};
5372
5373template<class _CharT, class _Traits, class _Yp>
5374inline _LIBCPP_INLINE_VISIBILITY
5375basic_ostream<_CharT, _Traits>&
5376operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
5377
5378
5379#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
5380
5381class _LIBCPP_TYPE_VIS __sp_mut
5382{
5383    void* __lx;
5384public:
5385    void lock() _NOEXCEPT;
5386    void unlock() _NOEXCEPT;
5387
5388private:
5389    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
5390    __sp_mut(const __sp_mut&);
5391    __sp_mut& operator=(const __sp_mut&);
5392
5393    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
5394};
5395
5396_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5397__sp_mut& __get_sp_mut(const void*);
5398
5399template <class _Tp>
5400inline _LIBCPP_INLINE_VISIBILITY
5401bool
5402atomic_is_lock_free(const shared_ptr<_Tp>*)
5403{
5404    return false;
5405}
5406
5407template <class _Tp>
5408_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5409shared_ptr<_Tp>
5410atomic_load(const shared_ptr<_Tp>* __p)
5411{
5412    __sp_mut& __m = __get_sp_mut(__p);
5413    __m.lock();
5414    shared_ptr<_Tp> __q = *__p;
5415    __m.unlock();
5416    return __q;
5417}
5418
5419template <class _Tp>
5420inline _LIBCPP_INLINE_VISIBILITY
5421_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5422shared_ptr<_Tp>
5423atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
5424{
5425    return atomic_load(__p);
5426}
5427
5428template <class _Tp>
5429_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5430void
5431atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5432{
5433    __sp_mut& __m = __get_sp_mut(__p);
5434    __m.lock();
5435    __p->swap(__r);
5436    __m.unlock();
5437}
5438
5439template <class _Tp>
5440inline _LIBCPP_INLINE_VISIBILITY
5441_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5442void
5443atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5444{
5445    atomic_store(__p, __r);
5446}
5447
5448template <class _Tp>
5449_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5450shared_ptr<_Tp>
5451atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5452{
5453    __sp_mut& __m = __get_sp_mut(__p);
5454    __m.lock();
5455    __p->swap(__r);
5456    __m.unlock();
5457    return __r;
5458}
5459
5460template <class _Tp>
5461inline _LIBCPP_INLINE_VISIBILITY
5462_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5463shared_ptr<_Tp>
5464atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5465{
5466    return atomic_exchange(__p, __r);
5467}
5468
5469template <class _Tp>
5470_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5471bool
5472atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5473{
5474    shared_ptr<_Tp> __temp;
5475    __sp_mut& __m = __get_sp_mut(__p);
5476    __m.lock();
5477    if (__p->__owner_equivalent(*__v))
5478    {
5479        _VSTD::swap(__temp, *__p);
5480        *__p = __w;
5481        __m.unlock();
5482        return true;
5483    }
5484    _VSTD::swap(__temp, *__v);
5485    *__v = *__p;
5486    __m.unlock();
5487    return false;
5488}
5489
5490template <class _Tp>
5491inline _LIBCPP_INLINE_VISIBILITY
5492_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5493bool
5494atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5495{
5496    return atomic_compare_exchange_strong(__p, __v, __w);
5497}
5498
5499template <class _Tp>
5500inline _LIBCPP_INLINE_VISIBILITY
5501_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5502bool
5503atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5504                                        shared_ptr<_Tp> __w, memory_order, memory_order)
5505{
5506    return atomic_compare_exchange_strong(__p, __v, __w);
5507}
5508
5509template <class _Tp>
5510inline _LIBCPP_INLINE_VISIBILITY
5511_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
5512bool
5513atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5514                                      shared_ptr<_Tp> __w, memory_order, memory_order)
5515{
5516    return atomic_compare_exchange_weak(__p, __v, __w);
5517}
5518
5519#endif  // !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
5520
5521//enum class
5522#if defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE)
5523# ifndef _LIBCPP_CXX03_LANG
5524enum class pointer_safety : unsigned char {
5525  relaxed,
5526  preferred,
5527  strict
5528};
5529# endif
5530#else
5531struct _LIBCPP_TYPE_VIS pointer_safety
5532{
5533    enum __lx
5534    {
5535        relaxed,
5536        preferred,
5537        strict
5538    };
5539
5540    __lx __v_;
5541
5542    _LIBCPP_INLINE_VISIBILITY
5543    pointer_safety() : __v_() {}
5544
5545    _LIBCPP_INLINE_VISIBILITY
5546    pointer_safety(__lx __v) : __v_(__v) {}
5547    _LIBCPP_INLINE_VISIBILITY
5548    operator int() const {return __v_;}
5549};
5550#endif
5551
5552#if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) && \
5553    defined(_LIBCPP_BUILDING_LIBRARY)
5554_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
5555#else
5556// This function is only offered in C++03 under ABI v1.
5557# if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) || !defined(_LIBCPP_CXX03_LANG)
5558inline _LIBCPP_INLINE_VISIBILITY
5559pointer_safety get_pointer_safety() _NOEXCEPT {
5560  return pointer_safety::relaxed;
5561}
5562# endif
5563#endif
5564
5565
5566_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
5567_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
5568_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
5569_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
5570
5571template <class _Tp>
5572inline _LIBCPP_INLINE_VISIBILITY
5573_Tp*
5574undeclare_reachable(_Tp* __p)
5575{
5576    return static_cast<_Tp*>(__undeclare_reachable(__p));
5577}
5578
5579_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
5580
5581// --- Helper for container swap --
5582template <typename _Alloc>
5583inline _LIBCPP_INLINE_VISIBILITY
5584void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
5585#if _LIBCPP_STD_VER >= 14
5586    _NOEXCEPT
5587#else
5588    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5589#endif
5590{
5591    __swap_allocator(__a1, __a2,
5592      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
5593}
5594
5595template <typename _Alloc>
5596_LIBCPP_INLINE_VISIBILITY
5597void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
5598#if _LIBCPP_STD_VER >= 14
5599    _NOEXCEPT
5600#else
5601    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5602#endif
5603{
5604    using _VSTD::swap;
5605    swap(__a1, __a2);
5606}
5607
5608template <typename _Alloc>
5609inline _LIBCPP_INLINE_VISIBILITY
5610void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
5611
5612template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
5613struct __noexcept_move_assign_container : public integral_constant<bool,
5614    _Traits::propagate_on_container_move_assignment::value
5615#if _LIBCPP_STD_VER > 14
5616        || _Traits::is_always_equal::value
5617#else
5618        && is_nothrow_move_assignable<_Alloc>::value
5619#endif
5620    > {};
5621
5622
5623#ifndef _LIBCPP_HAS_NO_VARIADICS
5624template <class _Tp, class _Alloc>
5625struct __temp_value {
5626    typedef allocator_traits<_Alloc> _Traits;
5627
5628    typename aligned_storage<sizeof(_Tp), alignof(_Tp)>::type __v;
5629    _Alloc &__a;
5630
5631    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
5632    _Tp &   get() { return *__addr(); }
5633
5634    template<class... _Args>
5635    _LIBCPP_NO_CFI
5636    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
5637      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
5638                         _VSTD::forward<_Args>(__args)...);
5639    }
5640
5641    ~__temp_value() { _Traits::destroy(__a, __addr()); }
5642    };
5643#endif
5644
5645template<typename _Alloc, typename = void, typename = void>
5646struct __is_allocator : false_type {};
5647
5648template<typename _Alloc>
5649struct __is_allocator<_Alloc,
5650       typename __void_t<typename _Alloc::value_type>::type,
5651       typename __void_t<decltype(_VSTD::declval<_Alloc&>().allocate(size_t(0)))>::type
5652     >
5653   : true_type {};
5654
5655_LIBCPP_END_NAMESPACE_STD
5656
5657_LIBCPP_POP_MACROS
5658
5659#endif  // _LIBCPP_MEMORY
5660