xref: /llvm-project-15.0.7/libcxx/include/memory (revision 30e818db)
1// -*- C++ -*-
2//===-------------------------- memory ------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_MEMORY
11#define _LIBCPP_MEMORY
12
13/*
14    memory synopsis
15
16namespace std
17{
18
19struct allocator_arg_t { };
20inline constexpr allocator_arg_t allocator_arg = allocator_arg_t();
21
22template <class T, class Alloc> struct uses_allocator;
23
24template <class Ptr>
25struct pointer_traits
26{
27    typedef Ptr pointer;
28    typedef <details> element_type;
29    typedef <details> difference_type;
30
31    template <class U> using rebind = <details>;
32
33    static pointer pointer_to(<details>);
34};
35
36template <class T>
37struct pointer_traits<T*>
38{
39    typedef T* pointer;
40    typedef T element_type;
41    typedef ptrdiff_t difference_type;
42
43    template <class U> using rebind = U*;
44
45    static pointer pointer_to(<details>) noexcept; // constexpr in C++20
46};
47
48template <class T> constexpr T* to_address(T* p) noexcept; // C++20
49template <class Ptr> auto to_address(const Ptr& p) noexcept; // C++20
50
51template <class Alloc>
52struct allocator_traits
53{
54    typedef Alloc                        allocator_type;
55    typedef typename allocator_type::value_type
56                                         value_type;
57
58    typedef Alloc::pointer | value_type* pointer;
59    typedef Alloc::const_pointer
60          | pointer_traits<pointer>::rebind<const value_type>
61                                         const_pointer;
62    typedef Alloc::void_pointer
63          | pointer_traits<pointer>::rebind<void>
64                                         void_pointer;
65    typedef Alloc::const_void_pointer
66          | pointer_traits<pointer>::rebind<const void>
67                                         const_void_pointer;
68    typedef Alloc::difference_type
69          | pointer_traits<pointer>::difference_type
70                                         difference_type;
71    typedef Alloc::size_type
72          | make_unsigned<difference_type>::type
73                                         size_type;
74    typedef Alloc::propagate_on_container_copy_assignment
75          | false_type                   propagate_on_container_copy_assignment;
76    typedef Alloc::propagate_on_container_move_assignment
77          | false_type                   propagate_on_container_move_assignment;
78    typedef Alloc::propagate_on_container_swap
79          | false_type                   propagate_on_container_swap;
80    typedef Alloc::is_always_equal
81          | is_empty                     is_always_equal;
82
83    template <class T> using rebind_alloc  = Alloc::rebind<T>::other | Alloc<T, Args...>;
84    template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
85
86    static pointer allocate(allocator_type& a, size_type n);                          // constexpr and [[nodiscard]] in C++20
87    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint); // constexpr and [[nodiscard]] in C++20
88
89    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept; // constexpr in C++20
90
91    template <class T, class... Args>
92    static void construct(allocator_type& a, T* p, Args&&... args); // constexpr in C++20
93
94    template <class T>
95    static void destroy(allocator_type& a, T* p); // constexpr in C++20
96
97    static size_type max_size(const allocator_type& a); // noexcept in C++14, constexpr in C++20
98    static allocator_type select_on_container_copy_construction(const allocator_type& a); // constexpr in C++20
99};
100
101template <>
102class allocator<void> // deprecated in C++17, removed in C++20
103{
104public:
105    typedef void*                                 pointer;
106    typedef const void*                           const_pointer;
107    typedef void                                  value_type;
108
109    template <class _Up> struct rebind {typedef allocator<_Up> other;};
110};
111
112template <class T>
113class allocator
114{
115public:
116    typedef size_t    size_type;
117    typedef ptrdiff_t difference_type;
118    typedef T*        pointer;                           // deprecated in C++17, removed in C++20
119    typedef const T*  const_pointer;                     // deprecated in C++17, removed in C++20
120    typedef typename add_lvalue_reference<T>::type
121                      reference;                         // deprecated in C++17, removed in C++20
122    typedef typename add_lvalue_reference<const T>::type
123                      const_reference;                   // deprecated in C++17, removed in C++20
124
125    typedef T         value_type;
126
127    template <class U> struct rebind {typedef allocator<U> other;}; // deprecated in C++17, removed in C++20
128
129    typedef true_type propagate_on_container_move_assignment;
130    typedef true_type is_always_equal;
131
132    constexpr allocator() noexcept;                      // constexpr in C++20
133    constexpr allocator(const allocator&) noexcept;      // constexpr in C++20
134    template <class U>
135      constexpr allocator(const allocator<U>&) noexcept; // constexpr in C++20
136    ~allocator();                                        // constexpr in C++20
137    pointer address(reference x) const noexcept;             // deprecated in C++17, removed in C++20
138    const_pointer address(const_reference x) const noexcept; // deprecated in C++17, removed in C++20
139    T* allocate(size_t n, const void* hint);          // deprecated in C++17, removed in C++20
140    T* allocate(size_t n);                              // constexpr in C++20
141    void deallocate(T* p, size_t n) noexcept;           // constexpr in C++20
142    size_type max_size() const noexcept;              // deprecated in C++17, removed in C++20
143    template<class U, class... Args>
144        void construct(U* p, Args&&... args);         // deprecated in C++17, removed in C++20
145    template <class U>
146        void destroy(U* p);                           // deprecated in C++17, removed in C++20
147};
148
149template <class T, class U>
150bool operator==(const allocator<T>&, const allocator<U>&) noexcept; // constexpr in C++20
151
152template <class T, class U>
153bool operator!=(const allocator<T>&, const allocator<U>&) noexcept; // constexpr in C++20
154
155template <class OutputIterator, class T>
156class raw_storage_iterator
157    : public iterator<output_iterator_tag,
158                      T,                               // purposefully not C++03
159                      ptrdiff_t,                       // purposefully not C++03
160                      T*,                              // purposefully not C++03
161                      raw_storage_iterator&>           // purposefully not C++03
162{
163public:
164    explicit raw_storage_iterator(OutputIterator x);
165    raw_storage_iterator& operator*();
166    raw_storage_iterator& operator=(const T& element);
167    raw_storage_iterator& operator++();
168    raw_storage_iterator  operator++(int);
169};
170
171template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
172template <class T> void               return_temporary_buffer(T* p) noexcept;
173
174template <class T> T* addressof(T& r) noexcept;
175template <class T> T* addressof(const T&& r) noexcept = delete;
176
177template <class InputIterator, class ForwardIterator>
178ForwardIterator
179uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
180
181template <class InputIterator, class Size, class ForwardIterator>
182ForwardIterator
183uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
184
185template <class ForwardIterator, class T>
186void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
187
188template <class ForwardIterator, class Size, class T>
189ForwardIterator
190uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
191
192template <class T, class ...Args>
193constexpr T* construct_at(T* location, Args&& ...args); // since C++20
194
195template <class T>
196void destroy_at(T* location); // constexpr in C++20
197
198template <class ForwardIterator>
199void destroy(ForwardIterator first, ForwardIterator last); // constexpr in C++20
200
201template <class ForwardIterator, class Size>
202ForwardIterator destroy_n(ForwardIterator first, Size n); // constexpr in C++20
203
204template <class InputIterator, class ForwardIterator>
205 ForwardIterator uninitialized_move(InputIterator first, InputIterator last, ForwardIterator result);
206
207template <class InputIterator, class Size, class ForwardIterator>
208 pair<InputIterator,ForwardIterator> uninitialized_move_n(InputIterator first, Size n, ForwardIterator result);
209
210template <class ForwardIterator>
211 void uninitialized_value_construct(ForwardIterator first, ForwardIterator last);
212
213template <class ForwardIterator, class Size>
214 ForwardIterator uninitialized_value_construct_n(ForwardIterator first, Size n);
215
216template <class ForwardIterator>
217 void uninitialized_default_construct(ForwardIterator first, ForwardIterator last);
218
219template <class ForwardIterator, class Size>
220 ForwardIterator uninitialized_default_construct_n(ForwardIterator first, Size n);
221
222template <class Y> struct auto_ptr_ref {};      // deprecated in C++11, removed in C++17
223
224template<class X>
225class auto_ptr                                  // deprecated in C++11, removed in C++17
226{
227public:
228    typedef X element_type;
229
230    explicit auto_ptr(X* p =0) throw();
231    auto_ptr(auto_ptr&) throw();
232    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
233    auto_ptr& operator=(auto_ptr&) throw();
234    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
235    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
236    ~auto_ptr() throw();
237
238    typename add_lvalue_reference<X>::type operator*() const throw();
239    X* operator->() const throw();
240    X* get() const throw();
241    X* release() throw();
242    void reset(X* p =0) throw();
243
244    auto_ptr(auto_ptr_ref<X>) throw();
245    template<class Y> operator auto_ptr_ref<Y>() throw();
246    template<class Y> operator auto_ptr<Y>() throw();
247};
248
249template <class T>
250struct default_delete
251{
252    constexpr default_delete() noexcept = default;
253    template <class U> default_delete(const default_delete<U>&) noexcept;
254
255    void operator()(T*) const noexcept;
256};
257
258template <class T>
259struct default_delete<T[]>
260{
261    constexpr default_delete() noexcept = default;
262    void operator()(T*) const noexcept;
263    template <class U> void operator()(U*) const = delete;
264};
265
266template <class T, class D = default_delete<T>>
267class unique_ptr
268{
269public:
270    typedef see below pointer;
271    typedef T element_type;
272    typedef D deleter_type;
273
274    // constructors
275    constexpr unique_ptr() noexcept;
276    explicit unique_ptr(pointer p) noexcept;
277    unique_ptr(pointer p, see below d1) noexcept;
278    unique_ptr(pointer p, see below d2) noexcept;
279    unique_ptr(unique_ptr&& u) noexcept;
280    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
281    template <class U, class E>
282        unique_ptr(unique_ptr<U, E>&& u) noexcept;
283    template <class U>
284        unique_ptr(auto_ptr<U>&& u) noexcept;       // removed in C++17
285
286    // destructor
287    ~unique_ptr();
288
289    // assignment
290    unique_ptr& operator=(unique_ptr&& u) noexcept;
291    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
292    unique_ptr& operator=(nullptr_t) noexcept;
293
294    // observers
295    typename add_lvalue_reference<T>::type operator*() const;
296    pointer operator->() const noexcept;
297    pointer get() const noexcept;
298    deleter_type& get_deleter() noexcept;
299    const deleter_type& get_deleter() const noexcept;
300    explicit operator bool() const noexcept;
301
302    // modifiers
303    pointer release() noexcept;
304    void reset(pointer p = pointer()) noexcept;
305    void swap(unique_ptr& u) noexcept;
306};
307
308template <class T, class D>
309class unique_ptr<T[], D>
310{
311public:
312    typedef implementation-defined pointer;
313    typedef T element_type;
314    typedef D deleter_type;
315
316    // constructors
317    constexpr unique_ptr() noexcept;
318    explicit unique_ptr(pointer p) noexcept;
319    unique_ptr(pointer p, see below d) noexcept;
320    unique_ptr(pointer p, see below d) noexcept;
321    unique_ptr(unique_ptr&& u) noexcept;
322    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
323
324    // destructor
325    ~unique_ptr();
326
327    // assignment
328    unique_ptr& operator=(unique_ptr&& u) noexcept;
329    unique_ptr& operator=(nullptr_t) noexcept;
330
331    // observers
332    T& operator[](size_t i) const;
333    pointer get() const noexcept;
334    deleter_type& get_deleter() noexcept;
335    const deleter_type& get_deleter() const noexcept;
336    explicit operator bool() const noexcept;
337
338    // modifiers
339    pointer release() noexcept;
340    void reset(pointer p = pointer()) noexcept;
341    void reset(nullptr_t) noexcept;
342  template <class U> void reset(U) = delete;
343    void swap(unique_ptr& u) noexcept;
344};
345
346template <class T, class D>
347    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
348
349template <class T1, class D1, class T2, class D2>
350    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
351template <class T1, class D1, class T2, class D2>
352    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
353template <class T1, class D1, class T2, class D2>
354    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
355template <class T1, class D1, class T2, class D2>
356    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
357template <class T1, class D1, class T2, class D2>
358    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
359template <class T1, class D1, class T2, class D2>
360    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
361
362template <class T, class D>
363    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
364template <class T, class D>
365    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
366template <class T, class D>
367    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
368template <class T, class D>
369    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
370
371template <class T, class D>
372    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
373template <class T, class D>
374    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
375template <class T, class D>
376    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
377template <class T, class D>
378    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
379template <class T, class D>
380    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
381template <class T, class D>
382    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
383template <class T, class D>
384    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
385template <class T, class D>
386    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
387
388class bad_weak_ptr
389    : public std::exception
390{
391    bad_weak_ptr() noexcept;
392};
393
394template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
395template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
396template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
397
398template<class E, class T, class Y, class D>
399    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, unique_ptr<Y, D> const& p);
400
401template<class T>
402class shared_ptr
403{
404public:
405    typedef T element_type;
406    typedef weak_ptr<T> weak_type; // C++17
407
408    // constructors:
409    constexpr shared_ptr() noexcept;
410    template<class Y> explicit shared_ptr(Y* p);
411    template<class Y, class D> shared_ptr(Y* p, D d);
412    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
413    template <class D> shared_ptr(nullptr_t p, D d);
414    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
415    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
416    shared_ptr(const shared_ptr& r) noexcept;
417    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
418    shared_ptr(shared_ptr&& r) noexcept;
419    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
420    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
421    template<class Y> shared_ptr(auto_ptr<Y>&& r);          // removed in C++17
422    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
423    shared_ptr(nullptr_t) : shared_ptr() { }
424
425    // destructor:
426    ~shared_ptr();
427
428    // assignment:
429    shared_ptr& operator=(const shared_ptr& r) noexcept;
430    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
431    shared_ptr& operator=(shared_ptr&& r) noexcept;
432    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
433    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r); // removed in C++17
434    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
435
436    // modifiers:
437    void swap(shared_ptr& r) noexcept;
438    void reset() noexcept;
439    template<class Y> void reset(Y* p);
440    template<class Y, class D> void reset(Y* p, D d);
441    template<class Y, class D, class A> void reset(Y* p, D d, A a);
442
443    // observers:
444    T* get() const noexcept;
445    T& operator*() const noexcept;
446    T* operator->() const noexcept;
447    long use_count() const noexcept;
448    bool unique() const noexcept;
449    explicit operator bool() const noexcept;
450    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
451    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
452};
453
454template<class T>
455shared_ptr(weak_ptr<T>) -> shared_ptr<T>;
456template<class T, class D>
457shared_ptr(unique_ptr<T, D>) -> shared_ptr<T>;
458
459// shared_ptr comparisons:
460template<class T, class U>
461    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
462template<class T, class U>
463    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
464template<class T, class U>
465    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
466template<class T, class U>
467    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
468template<class T, class U>
469    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
470template<class T, class U>
471    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
472
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>
484bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
485template <class T>
486    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
487template <class T>
488    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
489template <class T>
490    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
491template <class T>
492    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
493template <class T>
494    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
495template <class T>
496    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
497
498// shared_ptr specialized algorithms:
499template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
500
501// shared_ptr casts:
502template<class T, class U>
503    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
504template<class T, class U>
505    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
506template<class T, class U>
507    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
508
509// shared_ptr I/O:
510template<class E, class T, class Y>
511    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
512
513// shared_ptr get_deleter:
514template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
515
516template<class T, class... Args>
517    shared_ptr<T> make_shared(Args&&... args);
518template<class T, class A, class... Args>
519    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
520
521template<class T>
522class weak_ptr
523{
524public:
525    typedef T element_type;
526
527    // constructors
528    constexpr weak_ptr() noexcept;
529    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
530    weak_ptr(weak_ptr const& r) noexcept;
531    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
532    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
533    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
534
535    // destructor
536    ~weak_ptr();
537
538    // assignment
539    weak_ptr& operator=(weak_ptr const& r) noexcept;
540    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
541    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
542    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
543    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
544
545    // modifiers
546    void swap(weak_ptr& r) noexcept;
547    void reset() noexcept;
548
549    // observers
550    long use_count() const noexcept;
551    bool expired() const noexcept;
552    shared_ptr<T> lock() const noexcept;
553    template<class U> bool owner_before(shared_ptr<U> const& b) const noexcept;
554    template<class U> bool owner_before(weak_ptr<U> const& b) const noexcept;
555};
556
557template<class T>
558weak_ptr(shared_ptr<T>) -> weak_ptr<T>;
559
560// weak_ptr specialized algorithms:
561template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
562
563// class owner_less:
564template<class T> struct owner_less;
565
566template<class T>
567struct owner_less<shared_ptr<T> >
568    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
569{
570    typedef bool result_type;
571    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const noexcept;
572    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
573    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
574};
575
576template<class T>
577struct owner_less<weak_ptr<T> >
578    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
579{
580    typedef bool result_type;
581    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const noexcept;
582    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const noexcept;
583    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const noexcept;
584};
585
586template <>  // Added in C++14
587struct owner_less<void>
588{
589    template <class _Tp, class _Up>
590    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
591    template <class _Tp, class _Up>
592    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
593    template <class _Tp, class _Up>
594    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const noexcept;
595    template <class _Tp, class _Up>
596    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const noexcept;
597
598    typedef void is_transparent;
599};
600
601template<class T>
602class enable_shared_from_this
603{
604protected:
605    constexpr enable_shared_from_this() noexcept;
606    enable_shared_from_this(enable_shared_from_this const&) noexcept;
607    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
608    ~enable_shared_from_this();
609public:
610    shared_ptr<T> shared_from_this();
611    shared_ptr<T const> shared_from_this() const;
612};
613
614template<class T>
615    bool atomic_is_lock_free(const shared_ptr<T>* p);
616template<class T>
617    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
618template<class T>
619    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
620template<class T>
621    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
622template<class T>
623    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
624template<class T>
625    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
626template<class T>
627    shared_ptr<T>
628    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
629template<class T>
630    bool
631    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
632template<class T>
633    bool
634    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
635template<class T>
636    bool
637    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
638                                          shared_ptr<T> w, memory_order success,
639                                          memory_order failure);
640template<class T>
641    bool
642    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
643                                            shared_ptr<T> w, memory_order success,
644                                            memory_order failure);
645// Hash support
646template <class T> struct hash;
647template <class T, class D> struct hash<unique_ptr<T, D> >;
648template <class T> struct hash<shared_ptr<T> >;
649
650template <class T, class Alloc>
651  inline constexpr bool uses_allocator_v = uses_allocator<T, Alloc>::value;
652
653// Pointer safety
654enum class pointer_safety { relaxed, preferred, strict };
655void declare_reachable(void *p);
656template <class T> T *undeclare_reachable(T *p);
657void declare_no_pointers(char *p, size_t n);
658void undeclare_no_pointers(char *p, size_t n);
659pointer_safety get_pointer_safety() noexcept;
660
661void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
662
663}  // std
664
665*/
666
667#include <__config>
668#include <type_traits>
669#include <typeinfo>
670#include <cstddef>
671#include <cstdint>
672#include <new>
673#include <utility>
674#include <limits>
675#include <iterator>
676#include <__functional_base>
677#include <iosfwd>
678#include <tuple>
679#include <stdexcept>
680#include <cstring>
681#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
682#  include <atomic>
683#endif
684#include <version>
685
686#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
687#pragma GCC system_header
688#endif
689
690_LIBCPP_PUSH_MACROS
691#include <__undef_macros>
692
693
694_LIBCPP_BEGIN_NAMESPACE_STD
695
696template <class _ValueType>
697inline _LIBCPP_INLINE_VISIBILITY
698_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
699#if !defined(_LIBCPP_HAS_NO_THREADS) && \
700    defined(__ATOMIC_RELAXED) &&        \
701    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
702    return __atomic_load_n(__value, __ATOMIC_RELAXED);
703#else
704    return *__value;
705#endif
706}
707
708template <class _ValueType>
709inline _LIBCPP_INLINE_VISIBILITY
710_ValueType __libcpp_acquire_load(_ValueType const* __value) {
711#if !defined(_LIBCPP_HAS_NO_THREADS) && \
712    defined(__ATOMIC_ACQUIRE) &&        \
713    (__has_builtin(__atomic_load_n) || defined(_LIBCPP_COMPILER_GCC))
714    return __atomic_load_n(__value, __ATOMIC_ACQUIRE);
715#else
716    return *__value;
717#endif
718}
719
720// addressof moved to <type_traits>
721
722template <class _Tp> class allocator;
723
724#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
725template <>
726class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 allocator<void>
727{
728public:
729    typedef void*             pointer;
730    typedef const void*       const_pointer;
731    typedef void              value_type;
732
733    template <class _Up> struct rebind {typedef allocator<_Up> other;};
734};
735
736template <>
737class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX17 allocator<const void>
738{
739public:
740    typedef const void*       pointer;
741    typedef const void*       const_pointer;
742    typedef const void        value_type;
743
744    template <class _Up> struct rebind {typedef allocator<_Up> other;};
745};
746#endif
747
748// pointer_traits
749
750template <class _Tp, class = void>
751struct __has_element_type : false_type {};
752
753template <class _Tp>
754struct __has_element_type<_Tp,
755              typename __void_t<typename _Tp::element_type>::type> : true_type {};
756
757template <class _Ptr, bool = __has_element_type<_Ptr>::value>
758struct __pointer_traits_element_type;
759
760template <class _Ptr>
761struct __pointer_traits_element_type<_Ptr, true>
762{
763    typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::element_type type;
764};
765
766template <template <class, class...> class _Sp, class _Tp, class ..._Args>
767struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
768{
769    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::element_type type;
770};
771
772template <template <class, class...> class _Sp, class _Tp, class ..._Args>
773struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
774{
775    typedef _LIBCPP_NODEBUG_TYPE _Tp type;
776};
777
778template <class _Tp, class = void>
779struct __has_difference_type : false_type {};
780
781template <class _Tp>
782struct __has_difference_type<_Tp,
783            typename __void_t<typename _Tp::difference_type>::type> : true_type {};
784
785template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
786struct __pointer_traits_difference_type
787{
788    typedef _LIBCPP_NODEBUG_TYPE ptrdiff_t type;
789};
790
791template <class _Ptr>
792struct __pointer_traits_difference_type<_Ptr, true>
793{
794    typedef _LIBCPP_NODEBUG_TYPE typename _Ptr::difference_type type;
795};
796
797template <class _Tp, class _Up>
798struct __has_rebind
799{
800private:
801    struct __two {char __lx; char __lxx;};
802    template <class _Xp> static __two __test(...);
803    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
804    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
805    _LIBCPP_SUPPRESS_DEPRECATED_POP
806public:
807    static const bool value = sizeof(__test<_Tp>(0)) == 1;
808};
809
810template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
811struct __pointer_traits_rebind
812{
813#ifndef _LIBCPP_CXX03_LANG
814    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up> type;
815#else
816    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up>::other type;
817#endif
818};
819
820template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
821struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
822{
823#ifndef _LIBCPP_CXX03_LANG
824    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
825#else
826    typedef _LIBCPP_NODEBUG_TYPE typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
827#endif
828};
829
830template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
831struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
832{
833    typedef _Sp<_Up, _Args...> type;
834};
835
836template <class _Ptr>
837struct _LIBCPP_TEMPLATE_VIS pointer_traits
838{
839    typedef _Ptr                                                     pointer;
840    typedef typename __pointer_traits_element_type<pointer>::type    element_type;
841    typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
842
843#ifndef _LIBCPP_CXX03_LANG
844    template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
845#else
846    template <class _Up> struct rebind
847        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
848#endif  // _LIBCPP_CXX03_LANG
849
850private:
851    struct __nat {};
852public:
853    _LIBCPP_INLINE_VISIBILITY
854    static pointer pointer_to(typename conditional<is_void<element_type>::value,
855                                           __nat, element_type>::type& __r)
856        {return pointer::pointer_to(__r);}
857};
858
859template <class _Tp>
860struct _LIBCPP_TEMPLATE_VIS pointer_traits<_Tp*>
861{
862    typedef _Tp*      pointer;
863    typedef _Tp       element_type;
864    typedef ptrdiff_t difference_type;
865
866#ifndef _LIBCPP_CXX03_LANG
867    template <class _Up> using rebind = _Up*;
868#else
869    template <class _Up> struct rebind {typedef _Up* other;};
870#endif
871
872private:
873    struct __nat {};
874public:
875    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
876    static pointer pointer_to(typename conditional<is_void<element_type>::value,
877                                      __nat, element_type>::type& __r) _NOEXCEPT
878        {return _VSTD::addressof(__r);}
879};
880
881template <class _From, class _To>
882struct __rebind_pointer {
883#ifndef _LIBCPP_CXX03_LANG
884    typedef typename pointer_traits<_From>::template rebind<_To>        type;
885#else
886    typedef typename pointer_traits<_From>::template rebind<_To>::other type;
887#endif
888};
889
890// construct_at
891
892#if _LIBCPP_STD_VER > 17
893
894template<class _Tp>
895_LIBCPP_CONSTEXPR_AFTER_CXX17 void* __voidify(_Tp& __ptr) noexcept {
896    return const_cast<void*>(static_cast<const volatile void*>(_VSTD::addressof(__ptr)));
897}
898
899template<class _Tp, class ..._Args, class = decltype(
900    ::new (_VSTD::declval<void*>()) _Tp(_VSTD::declval<_Args>()...)
901)>
902_LIBCPP_INLINE_VISIBILITY
903constexpr _Tp* construct_at(_Tp* __location, _Args&& ...__args) {
904    _LIBCPP_ASSERT(__location, "null pointer given to construct_at");
905    return ::new (_VSTD::__voidify(*__location)) _Tp(_VSTD::forward<_Args>(__args)...);
906}
907
908#endif
909
910// destroy_at
911
912#if _LIBCPP_STD_VER > 14
913
914template <class _Tp>
915inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
916void destroy_at(_Tp* __loc) {
917    _LIBCPP_ASSERT(__loc, "null pointer given to destroy_at");
918    __loc->~_Tp();
919}
920
921#endif
922
923// allocator_traits
924
925template <class _Tp, class = void>
926struct __has_pointer_type : false_type {};
927
928template <class _Tp>
929struct __has_pointer_type<_Tp,
930          typename __void_t<typename _Tp::pointer>::type> : true_type {};
931
932namespace __pointer_type_imp
933{
934
935template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
936struct __pointer_type
937{
938    typedef _LIBCPP_NODEBUG_TYPE typename _Dp::pointer type;
939};
940
941template <class _Tp, class _Dp>
942struct __pointer_type<_Tp, _Dp, false>
943{
944    typedef _LIBCPP_NODEBUG_TYPE _Tp* type;
945};
946
947}  // __pointer_type_imp
948
949template <class _Tp, class _Dp>
950struct __pointer_type
951{
952    typedef _LIBCPP_NODEBUG_TYPE typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
953};
954
955template <class _Tp, class = void>
956struct __has_const_pointer : false_type {};
957
958template <class _Tp>
959struct __has_const_pointer<_Tp,
960            typename __void_t<typename _Tp::const_pointer>::type> : true_type {};
961
962template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
963struct __const_pointer
964{
965    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::const_pointer type;
966};
967
968template <class _Tp, class _Ptr, class _Alloc>
969struct __const_pointer<_Tp, _Ptr, _Alloc, false>
970{
971#ifndef _LIBCPP_CXX03_LANG
972    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
973#else
974    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
975#endif
976};
977
978template <class _Tp, class = void>
979struct __has_void_pointer : false_type {};
980
981template <class _Tp>
982struct __has_void_pointer<_Tp,
983               typename __void_t<typename _Tp::void_pointer>::type> : true_type {};
984
985template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
986struct __void_pointer
987{
988    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::void_pointer type;
989};
990
991template <class _Ptr, class _Alloc>
992struct __void_pointer<_Ptr, _Alloc, false>
993{
994#ifndef _LIBCPP_CXX03_LANG
995    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<void> type;
996#else
997    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<void>::other type;
998#endif
999};
1000
1001template <class _Tp, class = void>
1002struct __has_const_void_pointer : false_type {};
1003
1004template <class _Tp>
1005struct __has_const_void_pointer<_Tp,
1006            typename __void_t<typename _Tp::const_void_pointer>::type> : true_type {};
1007
1008template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
1009struct __const_void_pointer
1010{
1011    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::const_void_pointer type;
1012};
1013
1014template <class _Ptr, class _Alloc>
1015struct __const_void_pointer<_Ptr, _Alloc, false>
1016{
1017#ifndef _LIBCPP_CXX03_LANG
1018    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const void> type;
1019#else
1020    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::template rebind<const void>::other type;
1021#endif
1022};
1023
1024
1025template <bool _UsePointerTraits> struct __to_address_helper;
1026
1027template <> struct __to_address_helper<true> {
1028    template <class _Pointer>
1029    using __return_type = decltype(pointer_traits<_Pointer>::to_address(std::declval<const _Pointer&>()));
1030
1031    template <class _Pointer>
1032    _LIBCPP_CONSTEXPR
1033    static __return_type<_Pointer>
1034    __do_it(const _Pointer &__p) _NOEXCEPT { return pointer_traits<_Pointer>::to_address(__p); }
1035};
1036
1037template <class _Pointer, bool _Dummy = true>
1038using __choose_to_address = __to_address_helper<_IsValidExpansion<__to_address_helper<_Dummy>::template __return_type, _Pointer>::value>;
1039
1040
1041template <class _Tp>
1042inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1043_Tp*
1044__to_address(_Tp* __p) _NOEXCEPT
1045{
1046    static_assert(!is_function<_Tp>::value, "_Tp is a function type");
1047    return __p;
1048}
1049
1050template <class _Pointer>
1051inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1052typename __choose_to_address<_Pointer>::template __return_type<_Pointer>
1053__to_address(const _Pointer& __p) _NOEXCEPT {
1054  return __choose_to_address<_Pointer>::__do_it(__p);
1055}
1056
1057template <> struct __to_address_helper<false> {
1058    template <class _Pointer>
1059    using __return_type = typename pointer_traits<_Pointer>::element_type*;
1060
1061    template <class _Pointer>
1062    _LIBCPP_CONSTEXPR
1063    static __return_type<_Pointer>
1064    __do_it(const _Pointer &__p) _NOEXCEPT { return std::__to_address(__p.operator->()); }
1065};
1066
1067
1068#if _LIBCPP_STD_VER > 17
1069template <class _Tp>
1070inline _LIBCPP_INLINE_VISIBILITY constexpr
1071_Tp*
1072to_address(_Tp* __p) _NOEXCEPT
1073{
1074    static_assert(!is_function_v<_Tp>, "_Tp is a function type");
1075    return __p;
1076}
1077
1078template <class _Pointer>
1079inline _LIBCPP_INLINE_VISIBILITY
1080auto
1081to_address(const _Pointer& __p) _NOEXCEPT
1082{
1083    return _VSTD::__to_address(__p);
1084}
1085#endif
1086
1087template <class _Tp, class = void>
1088struct __has_size_type : false_type {};
1089
1090template <class _Tp>
1091struct __has_size_type<_Tp,
1092               typename __void_t<typename _Tp::size_type>::type> : true_type {};
1093
1094template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
1095struct __size_type
1096{
1097    typedef _LIBCPP_NODEBUG_TYPE typename make_unsigned<_DiffType>::type type;
1098};
1099
1100template <class _Alloc, class _DiffType>
1101struct __size_type<_Alloc, _DiffType, true>
1102{
1103    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::size_type type;
1104};
1105
1106template <class _Tp, class = void>
1107struct __has_propagate_on_container_copy_assignment : false_type {};
1108
1109template <class _Tp>
1110struct __has_propagate_on_container_copy_assignment<_Tp,
1111    typename __void_t<typename _Tp::propagate_on_container_copy_assignment>::type>
1112        : true_type {};
1113
1114template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
1115struct __propagate_on_container_copy_assignment
1116{
1117    typedef _LIBCPP_NODEBUG_TYPE false_type type;
1118};
1119
1120template <class _Alloc>
1121struct __propagate_on_container_copy_assignment<_Alloc, true>
1122{
1123    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_copy_assignment type;
1124};
1125
1126template <class _Tp, class = void>
1127struct __has_propagate_on_container_move_assignment : false_type {};
1128
1129template <class _Tp>
1130struct __has_propagate_on_container_move_assignment<_Tp,
1131           typename __void_t<typename _Tp::propagate_on_container_move_assignment>::type>
1132               : true_type {};
1133
1134template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
1135struct __propagate_on_container_move_assignment
1136{
1137    typedef false_type type;
1138};
1139
1140template <class _Alloc>
1141struct __propagate_on_container_move_assignment<_Alloc, true>
1142{
1143    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_move_assignment type;
1144};
1145
1146template <class _Tp, class = void>
1147struct __has_propagate_on_container_swap : false_type {};
1148
1149template <class _Tp>
1150struct __has_propagate_on_container_swap<_Tp,
1151           typename __void_t<typename _Tp::propagate_on_container_swap>::type>
1152               : true_type {};
1153
1154template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
1155struct __propagate_on_container_swap
1156{
1157    typedef false_type type;
1158};
1159
1160template <class _Alloc>
1161struct __propagate_on_container_swap<_Alloc, true>
1162{
1163    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::propagate_on_container_swap type;
1164};
1165
1166template <class _Tp, class = void>
1167struct __has_is_always_equal : false_type {};
1168
1169template <class _Tp>
1170struct __has_is_always_equal<_Tp,
1171           typename __void_t<typename _Tp::is_always_equal>::type>
1172               : true_type {};
1173
1174template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
1175struct __is_always_equal
1176{
1177    typedef _LIBCPP_NODEBUG_TYPE typename _VSTD::is_empty<_Alloc>::type type;
1178};
1179
1180template <class _Alloc>
1181struct __is_always_equal<_Alloc, true>
1182{
1183    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::is_always_equal type;
1184};
1185
1186template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
1187struct __has_rebind_other
1188{
1189private:
1190    struct __two {char __lx; char __lxx;};
1191    template <class _Xp> static __two __test(...);
1192    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1193    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
1194    _LIBCPP_SUPPRESS_DEPRECATED_POP
1195public:
1196    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1197};
1198
1199template <class _Tp, class _Up>
1200struct __has_rebind_other<_Tp, _Up, false>
1201{
1202    static const bool value = false;
1203};
1204
1205template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
1206struct __allocator_traits_rebind
1207{
1208    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1209    typedef _LIBCPP_NODEBUG_TYPE typename _Tp::template rebind<_Up>::other type;
1210    _LIBCPP_SUPPRESS_DEPRECATED_POP
1211};
1212
1213template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1214struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
1215{
1216    _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1217    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
1218    _LIBCPP_SUPPRESS_DEPRECATED_POP
1219};
1220
1221template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1222struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
1223{
1224    typedef _LIBCPP_NODEBUG_TYPE _Alloc<_Up, _Args...> type;
1225};
1226
1227#ifndef _LIBCPP_CXX03_LANG
1228
1229_LIBCPP_SUPPRESS_DEPRECATED_PUSH
1230template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1231auto
1232__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1233    -> decltype((void)__a.allocate(__sz, __p), true_type());
1234_LIBCPP_SUPPRESS_DEPRECATED_POP
1235
1236template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1237auto
1238__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1239    -> false_type;
1240
1241template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1242struct __has_allocate_hint
1243    : decltype(_VSTD::__has_allocate_hint_test(declval<_Alloc>(),
1244                                               declval<_SizeType>(),
1245                                               declval<_ConstVoidPtr>()))
1246{
1247};
1248
1249#else  // _LIBCPP_CXX03_LANG
1250
1251template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1252struct __has_allocate_hint
1253    : true_type
1254{
1255};
1256
1257#endif  // _LIBCPP_CXX03_LANG
1258
1259_LIBCPP_SUPPRESS_DEPRECATED_PUSH
1260template <class _Alloc, class ..._Args,
1261    class = decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Args>()...))>
1262static true_type __test_has_construct(int);
1263_LIBCPP_SUPPRESS_DEPRECATED_POP
1264
1265template <class _Alloc, class...>
1266static false_type __test_has_construct(...);
1267
1268template <class _Alloc, class ..._Args>
1269struct __has_construct : decltype(__test_has_construct<_Alloc, _Args...>(0)) {};
1270
1271#if !defined(_LIBCPP_CXX03_LANG)
1272
1273_LIBCPP_SUPPRESS_DEPRECATED_PUSH
1274template <class _Alloc, class _Pointer>
1275auto
1276__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
1277    -> decltype(__a.destroy(__p), true_type());
1278_LIBCPP_SUPPRESS_DEPRECATED_POP
1279
1280template <class _Alloc, class _Pointer>
1281auto
1282__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
1283    -> false_type;
1284
1285template <class _Alloc, class _Pointer>
1286struct __has_destroy
1287    : decltype(_VSTD::__has_destroy_test(declval<_Alloc>(),
1288                                         declval<_Pointer>()))
1289{
1290};
1291
1292_LIBCPP_SUPPRESS_DEPRECATED_PUSH
1293template <class _Alloc>
1294auto
1295__has_max_size_test(_Alloc&& __a)
1296    -> decltype(__a.max_size(), true_type());
1297_LIBCPP_SUPPRESS_DEPRECATED_POP
1298
1299template <class _Alloc>
1300auto
1301__has_max_size_test(const volatile _Alloc& __a)
1302    -> false_type;
1303
1304template <class _Alloc>
1305struct __has_max_size
1306    : decltype(_VSTD::__has_max_size_test(declval<_Alloc&>()))
1307{
1308};
1309
1310template <class _Alloc>
1311auto
1312__has_select_on_container_copy_construction_test(_Alloc&& __a)
1313    -> decltype(__a.select_on_container_copy_construction(), true_type());
1314
1315template <class _Alloc>
1316auto
1317__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
1318    -> false_type;
1319
1320template <class _Alloc>
1321struct __has_select_on_container_copy_construction
1322    : decltype(_VSTD::__has_select_on_container_copy_construction_test(declval<_Alloc&>()))
1323{
1324};
1325
1326#else  // _LIBCPP_CXX03_LANG
1327
1328template <class _Alloc, class _Pointer, class = void>
1329struct __has_destroy : false_type {};
1330
1331template <class _Alloc, class _Pointer>
1332struct __has_destroy<_Alloc, _Pointer, typename __void_t<
1333    decltype(_VSTD::declval<_Alloc>().destroy(_VSTD::declval<_Pointer>()))
1334>::type> : std::true_type {};
1335
1336template <class _Alloc>
1337struct __has_max_size
1338    : true_type
1339{
1340};
1341
1342template <class _Alloc>
1343struct __has_select_on_container_copy_construction
1344    : false_type
1345{
1346};
1347
1348#endif  // _LIBCPP_CXX03_LANG
1349
1350template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
1351struct __alloc_traits_difference_type
1352{
1353    typedef _LIBCPP_NODEBUG_TYPE typename pointer_traits<_Ptr>::difference_type type;
1354};
1355
1356template <class _Alloc, class _Ptr>
1357struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
1358{
1359    typedef _LIBCPP_NODEBUG_TYPE typename _Alloc::difference_type type;
1360};
1361
1362template <class _Tp>
1363struct __is_default_allocator : false_type {};
1364
1365template <class _Tp>
1366struct __is_default_allocator<_VSTD::allocator<_Tp> > : true_type {};
1367
1368
1369
1370template <class _Alloc,
1371    bool = __has_construct<_Alloc, typename _Alloc::value_type*,  typename _Alloc::value_type&&>::value && !__is_default_allocator<_Alloc>::value
1372    >
1373struct __is_cpp17_move_insertable;
1374template <class _Alloc>
1375struct __is_cpp17_move_insertable<_Alloc, true> : std::true_type {};
1376template <class _Alloc>
1377struct __is_cpp17_move_insertable<_Alloc, false> : std::is_move_constructible<typename _Alloc::value_type> {};
1378
1379template <class _Alloc,
1380    bool = __has_construct<_Alloc, typename _Alloc::value_type*, const typename _Alloc::value_type&>::value && !__is_default_allocator<_Alloc>::value
1381    >
1382struct __is_cpp17_copy_insertable;
1383template <class _Alloc>
1384struct __is_cpp17_copy_insertable<_Alloc, true> : __is_cpp17_move_insertable<_Alloc> {};
1385template <class _Alloc>
1386struct __is_cpp17_copy_insertable<_Alloc, false> : integral_constant<bool,
1387    std::is_copy_constructible<typename _Alloc::value_type>::value &&
1388    __is_cpp17_move_insertable<_Alloc>::value>
1389  {};
1390
1391
1392
1393template <class _Alloc>
1394struct _LIBCPP_TEMPLATE_VIS allocator_traits
1395{
1396    typedef _Alloc                              allocator_type;
1397    typedef typename allocator_type::value_type value_type;
1398
1399    typedef typename __pointer_type<value_type, allocator_type>::type pointer;
1400    typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
1401    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
1402    typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;
1403
1404    typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
1405    typedef typename __size_type<allocator_type, difference_type>::type size_type;
1406
1407    typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
1408                     propagate_on_container_copy_assignment;
1409    typedef typename __propagate_on_container_move_assignment<allocator_type>::type
1410                     propagate_on_container_move_assignment;
1411    typedef typename __propagate_on_container_swap<allocator_type>::type
1412                     propagate_on_container_swap;
1413    typedef typename __is_always_equal<allocator_type>::type
1414                     is_always_equal;
1415
1416#ifndef _LIBCPP_CXX03_LANG
1417    template <class _Tp> using rebind_alloc =
1418                  typename __allocator_traits_rebind<allocator_type, _Tp>::type;
1419    template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp> >;
1420#else  // _LIBCPP_CXX03_LANG
1421    template <class _Tp> struct rebind_alloc
1422        {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
1423    template <class _Tp> struct rebind_traits
1424        {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
1425#endif  // _LIBCPP_CXX03_LANG
1426
1427    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1428    static pointer allocate(allocator_type& __a, size_type __n)
1429        {return __a.allocate(__n);}
1430    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1431    static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
1432        {return __allocate(__a, __n, __hint,
1433            __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}
1434
1435    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1436    static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
1437        {__a.deallocate(__p, __n);}
1438
1439    template <class _Tp, class... _Args>
1440        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1441        static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
1442            {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
1443                         __a, __p, _VSTD::forward<_Args>(__args)...);}
1444
1445    template <class _Tp>
1446        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1447        static void destroy(allocator_type& __a, _Tp* __p)
1448            {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}
1449
1450    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1451    static size_type max_size(const allocator_type& __a) _NOEXCEPT
1452        {return __max_size(__has_max_size<const allocator_type>(), __a);}
1453
1454    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1455    static allocator_type
1456        select_on_container_copy_construction(const allocator_type& __a)
1457            {return __select_on_container_copy_construction(
1458                __has_select_on_container_copy_construction<const allocator_type>(),
1459                __a);}
1460
1461    template <class _Ptr>
1462        _LIBCPP_INLINE_VISIBILITY
1463        static
1464        void
1465        __construct_forward_with_exception_guarantees(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
1466        {
1467            static_assert(__is_cpp17_move_insertable<allocator_type>::value,
1468              "The specified type does not meet the requirements of Cpp17MoveInsertible");
1469            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1470              construct(__a, _VSTD::__to_address(__begin2),
1471#ifdef _LIBCPP_NO_EXCEPTIONS
1472                        _VSTD::move(*__begin1)
1473#else
1474                        _VSTD::move_if_noexcept(*__begin1)
1475#endif
1476                        );
1477        }
1478
1479    template <class _Tp>
1480        _LIBCPP_INLINE_VISIBILITY
1481        static
1482        typename enable_if
1483        <
1484            (__is_default_allocator<allocator_type>::value
1485                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1486             is_trivially_move_constructible<_Tp>::value,
1487            void
1488        >::type
1489        __construct_forward_with_exception_guarantees(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
1490        {
1491            ptrdiff_t _Np = __end1 - __begin1;
1492            if (_Np > 0)
1493            {
1494                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
1495                __begin2 += _Np;
1496            }
1497        }
1498
1499    template <class _Iter, class _Ptr>
1500        _LIBCPP_INLINE_VISIBILITY
1501        static
1502        void
1503        __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
1504        {
1505            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1506                construct(__a, _VSTD::__to_address(__begin2), *__begin1);
1507        }
1508
1509    template <class _SourceTp, class _DestTp,
1510              class _RawSourceTp = typename remove_const<_SourceTp>::type,
1511              class _RawDestTp = typename remove_const<_DestTp>::type>
1512        _LIBCPP_INLINE_VISIBILITY
1513        static
1514        typename enable_if
1515        <
1516            is_trivially_copy_constructible<_DestTp>::value &&
1517            is_same<_RawSourceTp, _RawDestTp>::value &&
1518            (__is_default_allocator<allocator_type>::value ||
1519             !__has_construct<allocator_type, _DestTp*, _SourceTp&>::value),
1520            void
1521        >::type
1522        __construct_range_forward(allocator_type&, _SourceTp* __begin1, _SourceTp* __end1, _DestTp*& __begin2)
1523        {
1524            ptrdiff_t _Np = __end1 - __begin1;
1525            if (_Np > 0)
1526            {
1527                _VSTD::memcpy(const_cast<_RawDestTp*>(__begin2), __begin1, _Np * sizeof(_DestTp));
1528                __begin2 += _Np;
1529            }
1530        }
1531
1532    template <class _Ptr>
1533        _LIBCPP_INLINE_VISIBILITY
1534        static
1535        void
1536        __construct_backward_with_exception_guarantees(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
1537        {
1538            static_assert(__is_cpp17_move_insertable<allocator_type>::value,
1539              "The specified type does not meet the requirements of Cpp17MoveInsertable");
1540            while (__end1 != __begin1)
1541            {
1542              construct(__a, _VSTD::__to_address(__end2 - 1),
1543#ifdef _LIBCPP_NO_EXCEPTIONS
1544                        _VSTD::move(*--__end1)
1545#else
1546                        _VSTD::move_if_noexcept(*--__end1)
1547#endif
1548                        );
1549              --__end2;
1550            }
1551        }
1552
1553    template <class _Tp>
1554        _LIBCPP_INLINE_VISIBILITY
1555        static
1556        typename enable_if
1557        <
1558            (__is_default_allocator<allocator_type>::value
1559                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1560             is_trivially_move_constructible<_Tp>::value,
1561            void
1562        >::type
1563        __construct_backward_with_exception_guarantees(allocator_type&, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
1564        {
1565            ptrdiff_t _Np = __end1 - __begin1;
1566            __end2 -= _Np;
1567            if (_Np > 0)
1568                _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
1569        }
1570
1571private:
1572
1573    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1574    static pointer __allocate(allocator_type& __a, size_type __n,
1575        const_void_pointer __hint, true_type)
1576        {
1577            _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1578            return __a.allocate(__n, __hint);
1579            _LIBCPP_SUPPRESS_DEPRECATED_POP
1580        }
1581    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1582    static pointer __allocate(allocator_type& __a, size_type __n,
1583        const_void_pointer, false_type)
1584        {return __a.allocate(__n);}
1585
1586    template <class _Tp, class... _Args>
1587        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1588        static void __construct(true_type, allocator_type& __a, _Tp* __p, _Args&&... __args)
1589            {
1590                _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1591                __a.construct(__p, _VSTD::forward<_Args>(__args)...);
1592                _LIBCPP_SUPPRESS_DEPRECATED_POP
1593            }
1594
1595    template <class _Tp, class... _Args>
1596        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1597        static void __construct(false_type, allocator_type&, _Tp* __p, _Args&&... __args)
1598            {
1599#if _LIBCPP_STD_VER > 17
1600                _VSTD::construct_at(__p, _VSTD::forward<_Args>(__args)...);
1601#else
1602                ::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
1603#endif
1604            }
1605
1606    template <class _Tp>
1607        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1608        static void __destroy(true_type, allocator_type& __a, _Tp* __p)
1609            {
1610                _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1611                __a.destroy(__p);
1612                _LIBCPP_SUPPRESS_DEPRECATED_POP
1613            }
1614    template <class _Tp>
1615        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1616        static void __destroy(false_type, allocator_type&, _Tp* __p)
1617            {
1618#if _LIBCPP_STD_VER > 17
1619                _VSTD::destroy_at(__p);
1620#else
1621                __p->~_Tp();
1622#endif
1623            }
1624
1625    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1626    static size_type __max_size(true_type, const allocator_type& __a) _NOEXCEPT
1627            {
1628                _LIBCPP_SUPPRESS_DEPRECATED_PUSH
1629                return __a.max_size();
1630                _LIBCPP_SUPPRESS_DEPRECATED_POP
1631            }
1632
1633    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1634    static size_type __max_size(false_type, const allocator_type&) _NOEXCEPT
1635            {return numeric_limits<size_type>::max() / sizeof(value_type);}
1636
1637    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1638    static allocator_type
1639        __select_on_container_copy_construction(true_type, const allocator_type& __a)
1640            {return __a.select_on_container_copy_construction();}
1641    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1642    static allocator_type
1643        __select_on_container_copy_construction(false_type, const allocator_type& __a)
1644            {return __a;}
1645};
1646
1647template <class _Traits, class _Tp>
1648struct __rebind_alloc_helper
1649{
1650#ifndef _LIBCPP_CXX03_LANG
1651    typedef _LIBCPP_NODEBUG_TYPE typename _Traits::template rebind_alloc<_Tp>        type;
1652#else
1653    typedef typename _Traits::template rebind_alloc<_Tp>::other type;
1654#endif
1655};
1656
1657// allocator
1658
1659template <class _Tp>
1660class _LIBCPP_TEMPLATE_VIS allocator
1661{
1662public:
1663    typedef size_t      size_type;
1664    typedef ptrdiff_t   difference_type;
1665    typedef _Tp         value_type;
1666    typedef true_type   propagate_on_container_move_assignment;
1667    typedef true_type   is_always_equal;
1668
1669    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1670    allocator() _NOEXCEPT { }
1671
1672    template <class _Up>
1673    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1674    allocator(const allocator<_Up>&) _NOEXCEPT { }
1675
1676    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1677    _Tp* allocate(size_t __n) {
1678        if (__n > allocator_traits<allocator>::max_size(*this))
1679            __throw_length_error("allocator<T>::allocate(size_t n)"
1680                                 " 'n' exceeds maximum supported size");
1681        if (__libcpp_is_constant_evaluated()) {
1682            return static_cast<_Tp*>(::operator new(__n * sizeof(_Tp)));
1683        } else {
1684            return static_cast<_Tp*>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1685        }
1686    }
1687
1688    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1689    void deallocate(_Tp* __p, size_t __n) _NOEXCEPT {
1690        if (__libcpp_is_constant_evaluated()) {
1691            ::operator delete(__p);
1692        } else {
1693            _VSTD::__libcpp_deallocate((void*)__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
1694        }
1695    }
1696
1697    // C++20 Removed members
1698#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1699    _LIBCPP_DEPRECATED_IN_CXX17 typedef _Tp*       pointer;
1700    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp* const_pointer;
1701    _LIBCPP_DEPRECATED_IN_CXX17 typedef _Tp&       reference;
1702    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp& const_reference;
1703
1704    template <class _Up>
1705    struct _LIBCPP_DEPRECATED_IN_CXX17 rebind {
1706        typedef allocator<_Up> other;
1707    };
1708
1709    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1710    pointer address(reference __x) const _NOEXCEPT {
1711        return _VSTD::addressof(__x);
1712    }
1713    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1714    const_pointer address(const_reference __x) const _NOEXCEPT {
1715        return _VSTD::addressof(__x);
1716    }
1717
1718    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_DEPRECATED_IN_CXX17
1719    _Tp* allocate(size_t __n, const void*) {
1720        return allocate(__n);
1721    }
1722
1723    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT {
1724        return size_type(~0) / sizeof(_Tp);
1725    }
1726
1727    template <class _Up, class... _Args>
1728    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1729    void construct(_Up* __p, _Args&&... __args) {
1730        ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1731    }
1732
1733    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1734    void destroy(pointer __p) {
1735        __p->~_Tp();
1736    }
1737#endif
1738};
1739
1740template <class _Tp>
1741class _LIBCPP_TEMPLATE_VIS allocator<const _Tp>
1742{
1743public:
1744    typedef size_t      size_type;
1745    typedef ptrdiff_t   difference_type;
1746    typedef const _Tp   value_type;
1747    typedef true_type   propagate_on_container_move_assignment;
1748    typedef true_type   is_always_equal;
1749
1750    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1751    allocator() _NOEXCEPT { }
1752
1753    template <class _Up>
1754    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1755    allocator(const allocator<_Up>&) _NOEXCEPT { }
1756
1757    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1758    const _Tp* allocate(size_t __n) {
1759        if (__n > allocator_traits<allocator>::max_size(*this))
1760            __throw_length_error("allocator<const T>::allocate(size_t n)"
1761                                 " 'n' exceeds maximum supported size");
1762        if (__libcpp_is_constant_evaluated()) {
1763            return static_cast<const _Tp*>(::operator new(__n * sizeof(_Tp)));
1764        } else {
1765            return static_cast<const _Tp*>(_VSTD::__libcpp_allocate(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)));
1766        }
1767    }
1768
1769    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1770    void deallocate(const _Tp* __p, size_t __n) {
1771        if (__libcpp_is_constant_evaluated()) {
1772            ::operator delete(const_cast<_Tp*>(__p));
1773        } else {
1774            _VSTD::__libcpp_deallocate((void*) const_cast<_Tp *>(__p), __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
1775        }
1776    }
1777
1778    // C++20 Removed members
1779#if _LIBCPP_STD_VER <= 17 || defined(_LIBCPP_ENABLE_CXX20_REMOVED_ALLOCATOR_MEMBERS)
1780    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp* pointer;
1781    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp* const_pointer;
1782    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp& reference;
1783    _LIBCPP_DEPRECATED_IN_CXX17 typedef const _Tp& const_reference;
1784
1785    template <class _Up>
1786    struct _LIBCPP_DEPRECATED_IN_CXX17 rebind {
1787        typedef allocator<_Up> other;
1788    };
1789
1790    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1791    const_pointer address(const_reference __x) const _NOEXCEPT {
1792        return _VSTD::addressof(__x);
1793    }
1794
1795    _LIBCPP_NODISCARD_AFTER_CXX17 _LIBCPP_INLINE_VISIBILITY _LIBCPP_DEPRECATED_IN_CXX17
1796    const _Tp* allocate(size_t __n, const void*) {
1797        return allocate(__n);
1798    }
1799
1800    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT {
1801        return size_type(~0) / sizeof(_Tp);
1802    }
1803
1804    template <class _Up, class... _Args>
1805    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1806    void construct(_Up* __p, _Args&&... __args) {
1807        ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1808    }
1809
1810    _LIBCPP_DEPRECATED_IN_CXX17 _LIBCPP_INLINE_VISIBILITY
1811    void destroy(pointer __p) {
1812        __p->~_Tp();
1813    }
1814#endif
1815};
1816
1817template <class _Tp, class _Up>
1818inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1819bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
1820
1821template <class _Tp, class _Up>
1822inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
1823bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
1824
1825template <class _OutputIterator, class _Tp>
1826class _LIBCPP_TEMPLATE_VIS raw_storage_iterator
1827    : public iterator<output_iterator_tag,
1828                      _Tp,                                         // purposefully not C++03
1829                      ptrdiff_t,                                   // purposefully not C++03
1830                      _Tp*,                                        // purposefully not C++03
1831                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
1832{
1833private:
1834    _OutputIterator __x_;
1835public:
1836    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
1837    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
1838    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
1839        {::new(_VSTD::addressof(*__x_)) _Tp(__element); return *this;}
1840#if _LIBCPP_STD_VER >= 14
1841    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
1842        {::new(_VSTD::addressof(*__x_)) _Tp(_VSTD::move(__element)); return *this;}
1843#endif
1844    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
1845    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
1846        {raw_storage_iterator __t(*this); ++__x_; return __t;}
1847#if _LIBCPP_STD_VER >= 14
1848    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
1849#endif
1850};
1851
1852template <class _Tp>
1853_LIBCPP_NODISCARD_EXT _LIBCPP_NO_CFI
1854pair<_Tp*, ptrdiff_t>
1855get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
1856{
1857    pair<_Tp*, ptrdiff_t> __r(0, 0);
1858    const ptrdiff_t __m = (~ptrdiff_t(0) ^
1859                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
1860                           / sizeof(_Tp);
1861    if (__n > __m)
1862        __n = __m;
1863    while (__n > 0)
1864    {
1865#if !defined(_LIBCPP_HAS_NO_ALIGNED_ALLOCATION)
1866    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
1867        {
1868            std::align_val_t __al =
1869                std::align_val_t(std::alignment_of<_Tp>::value);
1870            __r.first = static_cast<_Tp*>(::operator new(
1871                __n * sizeof(_Tp), __al, nothrow));
1872        } else {
1873            __r.first = static_cast<_Tp*>(::operator new(
1874                __n * sizeof(_Tp), nothrow));
1875        }
1876#else
1877    if (__is_overaligned_for_new(_LIBCPP_ALIGNOF(_Tp)))
1878        {
1879            // Since aligned operator new is unavailable, return an empty
1880            // buffer rather than one with invalid alignment.
1881            return __r;
1882        }
1883
1884        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
1885#endif
1886
1887        if (__r.first)
1888        {
1889            __r.second = __n;
1890            break;
1891        }
1892        __n /= 2;
1893    }
1894    return __r;
1895}
1896
1897template <class _Tp>
1898inline _LIBCPP_INLINE_VISIBILITY
1899void return_temporary_buffer(_Tp* __p) _NOEXCEPT
1900{
1901  _VSTD::__libcpp_deallocate_unsized((void*)__p, _LIBCPP_ALIGNOF(_Tp));
1902}
1903
1904#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
1905template <class _Tp>
1906struct _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr_ref
1907{
1908    _Tp* __ptr_;
1909};
1910
1911template<class _Tp>
1912class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr
1913{
1914private:
1915    _Tp* __ptr_;
1916public:
1917    typedef _Tp element_type;
1918
1919    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) _NOEXCEPT : __ptr_(__p) {}
1920    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) _NOEXCEPT : __ptr_(__p.release()) {}
1921    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) _NOEXCEPT
1922        : __ptr_(__p.release()) {}
1923    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) _NOEXCEPT
1924        {reset(__p.release()); return *this;}
1925    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) _NOEXCEPT
1926        {reset(__p.release()); return *this;}
1927    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) _NOEXCEPT
1928        {reset(__p.__ptr_); return *this;}
1929    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() _NOEXCEPT {delete __ptr_;}
1930
1931    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const _NOEXCEPT
1932        {return *__ptr_;}
1933    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const _NOEXCEPT {return __ptr_;}
1934    _LIBCPP_INLINE_VISIBILITY _Tp* get() const _NOEXCEPT {return __ptr_;}
1935    _LIBCPP_INLINE_VISIBILITY _Tp* release() _NOEXCEPT
1936    {
1937        _Tp* __t = __ptr_;
1938        __ptr_ = 0;
1939        return __t;
1940    }
1941    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) _NOEXCEPT
1942    {
1943        if (__ptr_ != __p)
1944            delete __ptr_;
1945        __ptr_ = __p;
1946    }
1947
1948    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) _NOEXCEPT : __ptr_(__p.__ptr_) {}
1949    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() _NOEXCEPT
1950        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
1951    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() _NOEXCEPT
1952        {return auto_ptr<_Up>(release());}
1953};
1954
1955template <>
1956class _LIBCPP_TEMPLATE_VIS _LIBCPP_DEPRECATED_IN_CXX11 auto_ptr<void>
1957{
1958public:
1959    typedef void element_type;
1960};
1961#endif
1962
1963// Tag used to default initialize one or both of the pair's elements.
1964struct __default_init_tag {};
1965struct __value_init_tag {};
1966
1967template <class _Tp, int _Idx,
1968          bool _CanBeEmptyBase =
1969              is_empty<_Tp>::value && !__libcpp_is_final<_Tp>::value>
1970struct __compressed_pair_elem {
1971  typedef _Tp _ParamT;
1972  typedef _Tp& reference;
1973  typedef const _Tp& const_reference;
1974
1975  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1976  __compressed_pair_elem(__default_init_tag) {}
1977  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
1978  __compressed_pair_elem(__value_init_tag) : __value_() {}
1979
1980  template <class _Up, class = typename enable_if<
1981      !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
1982  >::type>
1983  _LIBCPP_INLINE_VISIBILITY
1984  _LIBCPP_CONSTEXPR explicit
1985  __compressed_pair_elem(_Up&& __u)
1986      : __value_(_VSTD::forward<_Up>(__u))
1987    {
1988    }
1989
1990
1991#ifndef _LIBCPP_CXX03_LANG
1992  template <class... _Args, size_t... _Indexes>
1993  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
1994  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
1995                         __tuple_indices<_Indexes...>)
1996      : __value_(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
1997#endif
1998
1999
2000  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return __value_; }
2001  _LIBCPP_INLINE_VISIBILITY
2002  const_reference __get() const _NOEXCEPT { return __value_; }
2003
2004private:
2005  _Tp __value_;
2006};
2007
2008template <class _Tp, int _Idx>
2009struct __compressed_pair_elem<_Tp, _Idx, true> : private _Tp {
2010  typedef _Tp _ParamT;
2011  typedef _Tp& reference;
2012  typedef const _Tp& const_reference;
2013  typedef _Tp __value_type;
2014
2015  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR __compressed_pair_elem() = default;
2016  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2017  __compressed_pair_elem(__default_init_tag) {}
2018  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2019  __compressed_pair_elem(__value_init_tag) : __value_type() {}
2020
2021  template <class _Up, class = typename enable_if<
2022        !is_same<__compressed_pair_elem, typename decay<_Up>::type>::value
2023  >::type>
2024  _LIBCPP_INLINE_VISIBILITY
2025  _LIBCPP_CONSTEXPR explicit
2026  __compressed_pair_elem(_Up&& __u)
2027      : __value_type(_VSTD::forward<_Up>(__u))
2028  {}
2029
2030#ifndef _LIBCPP_CXX03_LANG
2031  template <class... _Args, size_t... _Indexes>
2032  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2033  __compressed_pair_elem(piecewise_construct_t, tuple<_Args...> __args,
2034                         __tuple_indices<_Indexes...>)
2035      : __value_type(_VSTD::forward<_Args>(_VSTD::get<_Indexes>(__args))...) {}
2036#endif
2037
2038  _LIBCPP_INLINE_VISIBILITY reference __get() _NOEXCEPT { return *this; }
2039  _LIBCPP_INLINE_VISIBILITY
2040  const_reference __get() const _NOEXCEPT { return *this; }
2041};
2042
2043template <class _T1, class _T2>
2044class __compressed_pair : private __compressed_pair_elem<_T1, 0>,
2045                          private __compressed_pair_elem<_T2, 1> {
2046  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T1, 0> _Base1;
2047  typedef _LIBCPP_NODEBUG_TYPE __compressed_pair_elem<_T2, 1> _Base2;
2048
2049  // NOTE: This static assert should never fire because __compressed_pair
2050  // is *almost never* used in a scenario where it's possible for T1 == T2.
2051  // (The exception is std::function where it is possible that the function
2052  //  object and the allocator have the same type).
2053  static_assert((!is_same<_T1, _T2>::value),
2054    "__compressed_pair cannot be instantated when T1 and T2 are the same type; "
2055    "The current implementation is NOT ABI-compatible with the previous "
2056    "implementation for this configuration");
2057
2058public:
2059    template <bool _Dummy = true,
2060      class = typename enable_if<
2061          __dependent_type<is_default_constructible<_T1>, _Dummy>::value &&
2062          __dependent_type<is_default_constructible<_T2>, _Dummy>::value
2063      >::type
2064  >
2065  _LIBCPP_INLINE_VISIBILITY
2066  _LIBCPP_CONSTEXPR __compressed_pair() : _Base1(__value_init_tag()), _Base2(__value_init_tag()) {}
2067
2068  template <class _U1, class _U2>
2069  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
2070  __compressed_pair(_U1&& __t1, _U2&& __t2)
2071      : _Base1(std::forward<_U1>(__t1)), _Base2(std::forward<_U2>(__t2)) {}
2072
2073#ifndef _LIBCPP_CXX03_LANG
2074  template <class... _Args1, class... _Args2>
2075  _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX14
2076  __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
2077                    tuple<_Args2...> __second_args)
2078      : _Base1(__pc, _VSTD::move(__first_args),
2079               typename __make_tuple_indices<sizeof...(_Args1)>::type()),
2080        _Base2(__pc, _VSTD::move(__second_args),
2081               typename __make_tuple_indices<sizeof...(_Args2)>::type()) {}
2082#endif
2083
2084  _LIBCPP_INLINE_VISIBILITY
2085  typename _Base1::reference first() _NOEXCEPT {
2086    return static_cast<_Base1&>(*this).__get();
2087  }
2088
2089  _LIBCPP_INLINE_VISIBILITY
2090  typename _Base1::const_reference first() const _NOEXCEPT {
2091    return static_cast<_Base1 const&>(*this).__get();
2092  }
2093
2094  _LIBCPP_INLINE_VISIBILITY
2095  typename _Base2::reference second() _NOEXCEPT {
2096    return static_cast<_Base2&>(*this).__get();
2097  }
2098
2099  _LIBCPP_INLINE_VISIBILITY
2100  typename _Base2::const_reference second() const _NOEXCEPT {
2101    return static_cast<_Base2 const&>(*this).__get();
2102  }
2103
2104  _LIBCPP_INLINE_VISIBILITY
2105  void swap(__compressed_pair& __x)
2106    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2107               __is_nothrow_swappable<_T2>::value)
2108  {
2109    using std::swap;
2110    swap(first(), __x.first());
2111    swap(second(), __x.second());
2112  }
2113};
2114
2115template <class _T1, class _T2>
2116inline _LIBCPP_INLINE_VISIBILITY
2117void swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
2118    _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2119               __is_nothrow_swappable<_T2>::value) {
2120  __x.swap(__y);
2121}
2122
2123// default_delete
2124
2125template <class _Tp>
2126struct _LIBCPP_TEMPLATE_VIS default_delete {
2127    static_assert(!is_function<_Tp>::value,
2128                  "default_delete cannot be instantiated for function types");
2129#ifndef _LIBCPP_CXX03_LANG
2130  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2131#else
2132  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2133#endif
2134  template <class _Up>
2135  _LIBCPP_INLINE_VISIBILITY
2136  default_delete(const default_delete<_Up>&,
2137                 typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* =
2138                     0) _NOEXCEPT {}
2139
2140  _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __ptr) const _NOEXCEPT {
2141    static_assert(sizeof(_Tp) > 0,
2142                  "default_delete can not delete incomplete type");
2143    static_assert(!is_void<_Tp>::value,
2144                  "default_delete can not delete incomplete type");
2145    delete __ptr;
2146  }
2147};
2148
2149template <class _Tp>
2150struct _LIBCPP_TEMPLATE_VIS default_delete<_Tp[]> {
2151private:
2152  template <class _Up>
2153  struct _EnableIfConvertible
2154      : enable_if<is_convertible<_Up(*)[], _Tp(*)[]>::value> {};
2155
2156public:
2157#ifndef _LIBCPP_CXX03_LANG
2158  _LIBCPP_INLINE_VISIBILITY constexpr default_delete() _NOEXCEPT = default;
2159#else
2160  _LIBCPP_INLINE_VISIBILITY default_delete() {}
2161#endif
2162
2163  template <class _Up>
2164  _LIBCPP_INLINE_VISIBILITY
2165  default_delete(const default_delete<_Up[]>&,
2166                 typename _EnableIfConvertible<_Up>::type* = 0) _NOEXCEPT {}
2167
2168  template <class _Up>
2169  _LIBCPP_INLINE_VISIBILITY
2170  typename _EnableIfConvertible<_Up>::type
2171  operator()(_Up* __ptr) const _NOEXCEPT {
2172    static_assert(sizeof(_Tp) > 0,
2173                  "default_delete can not delete incomplete type");
2174    static_assert(!is_void<_Tp>::value,
2175                  "default_delete can not delete void type");
2176    delete[] __ptr;
2177  }
2178};
2179
2180template <class _Deleter>
2181struct __unique_ptr_deleter_sfinae {
2182  static_assert(!is_reference<_Deleter>::value, "incorrect specialization");
2183  typedef const _Deleter& __lval_ref_type;
2184  typedef _Deleter&& __good_rval_ref_type;
2185  typedef true_type __enable_rval_overload;
2186};
2187
2188template <class _Deleter>
2189struct __unique_ptr_deleter_sfinae<_Deleter const&> {
2190  typedef const _Deleter& __lval_ref_type;
2191  typedef const _Deleter&& __bad_rval_ref_type;
2192  typedef false_type __enable_rval_overload;
2193};
2194
2195template <class _Deleter>
2196struct __unique_ptr_deleter_sfinae<_Deleter&> {
2197  typedef _Deleter& __lval_ref_type;
2198  typedef _Deleter&& __bad_rval_ref_type;
2199  typedef false_type __enable_rval_overload;
2200};
2201
2202#if defined(_LIBCPP_ABI_ENABLE_UNIQUE_PTR_TRIVIAL_ABI)
2203#  define _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI __attribute__((trivial_abi))
2204#else
2205#  define _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI
2206#endif
2207
2208template <class _Tp, class _Dp = default_delete<_Tp> >
2209class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS unique_ptr {
2210public:
2211  typedef _Tp element_type;
2212  typedef _Dp deleter_type;
2213  typedef _LIBCPP_NODEBUG_TYPE typename __pointer_type<_Tp, deleter_type>::type pointer;
2214
2215  static_assert(!is_rvalue_reference<deleter_type>::value,
2216                "the specified deleter type cannot be an rvalue reference");
2217
2218private:
2219  __compressed_pair<pointer, deleter_type> __ptr_;
2220
2221  struct __nat { int __for_bool_; };
2222
2223  typedef _LIBCPP_NODEBUG_TYPE __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2224
2225  template <bool _Dummy>
2226  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2227      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2228
2229  template <bool _Dummy>
2230  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2231      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2232
2233  template <bool _Dummy>
2234  using _BadRValRefType _LIBCPP_NODEBUG_TYPE  =
2235      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2236
2237  template <bool _Dummy, class _Deleter = typename __dependent_type<
2238                             __identity<deleter_type>, _Dummy>::type>
2239  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE =
2240      typename enable_if<is_default_constructible<_Deleter>::value &&
2241                         !is_pointer<_Deleter>::value>::type;
2242
2243  template <class _ArgType>
2244  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2245      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2246
2247  template <class _UPtr, class _Up>
2248  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2249      is_convertible<typename _UPtr::pointer, pointer>::value &&
2250      !is_array<_Up>::value
2251  >::type;
2252
2253  template <class _UDel>
2254  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2255      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2256      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2257    >::type;
2258
2259  template <class _UDel>
2260  using _EnableIfDeleterAssignable = typename enable_if<
2261      is_assignable<_Dp&, _UDel&&>::value
2262    >::type;
2263
2264public:
2265  template <bool _Dummy = true,
2266            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2267  _LIBCPP_INLINE_VISIBILITY
2268  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2269
2270  template <bool _Dummy = true,
2271            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2272  _LIBCPP_INLINE_VISIBILITY
2273  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2274
2275  template <bool _Dummy = true,
2276            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2277  _LIBCPP_INLINE_VISIBILITY
2278  explicit unique_ptr(pointer __p) _NOEXCEPT : __ptr_(__p, __default_init_tag()) {}
2279
2280  template <bool _Dummy = true,
2281            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2282  _LIBCPP_INLINE_VISIBILITY
2283  unique_ptr(pointer __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2284      : __ptr_(__p, __d) {}
2285
2286  template <bool _Dummy = true,
2287            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2288  _LIBCPP_INLINE_VISIBILITY
2289  unique_ptr(pointer __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2290      : __ptr_(__p, _VSTD::move(__d)) {
2291    static_assert(!is_reference<deleter_type>::value,
2292                  "rvalue deleter bound to reference");
2293  }
2294
2295  template <bool _Dummy = true,
2296            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> > >
2297  _LIBCPP_INLINE_VISIBILITY
2298  unique_ptr(pointer __p, _BadRValRefType<_Dummy> __d) = delete;
2299
2300  _LIBCPP_INLINE_VISIBILITY
2301  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2302      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2303  }
2304
2305  template <class _Up, class _Ep,
2306      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2307      class = _EnableIfDeleterConvertible<_Ep>
2308  >
2309  _LIBCPP_INLINE_VISIBILITY
2310  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2311      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
2312
2313#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2314  template <class _Up>
2315  _LIBCPP_INLINE_VISIBILITY
2316  unique_ptr(auto_ptr<_Up>&& __p,
2317             typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2318                                    is_same<_Dp, default_delete<_Tp> >::value,
2319                                __nat>::type = __nat()) _NOEXCEPT
2320      : __ptr_(__p.release(), __default_init_tag()) {}
2321#endif
2322
2323  _LIBCPP_INLINE_VISIBILITY
2324  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2325    reset(__u.release());
2326    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2327    return *this;
2328  }
2329
2330  template <class _Up, class _Ep,
2331      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2332      class = _EnableIfDeleterAssignable<_Ep>
2333  >
2334  _LIBCPP_INLINE_VISIBILITY
2335  unique_ptr& operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2336    reset(__u.release());
2337    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2338    return *this;
2339  }
2340
2341#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
2342  template <class _Up>
2343  _LIBCPP_INLINE_VISIBILITY
2344      typename enable_if<is_convertible<_Up*, _Tp*>::value &&
2345                             is_same<_Dp, default_delete<_Tp> >::value,
2346                         unique_ptr&>::type
2347      operator=(auto_ptr<_Up> __p) {
2348    reset(__p.release());
2349    return *this;
2350  }
2351#endif
2352
2353#ifdef _LIBCPP_CXX03_LANG
2354  unique_ptr(unique_ptr const&) = delete;
2355  unique_ptr& operator=(unique_ptr const&) = delete;
2356#endif
2357
2358
2359  _LIBCPP_INLINE_VISIBILITY
2360  ~unique_ptr() { reset(); }
2361
2362  _LIBCPP_INLINE_VISIBILITY
2363  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2364    reset();
2365    return *this;
2366  }
2367
2368  _LIBCPP_INLINE_VISIBILITY
2369  typename add_lvalue_reference<_Tp>::type
2370  operator*() const {
2371    return *__ptr_.first();
2372  }
2373  _LIBCPP_INLINE_VISIBILITY
2374  pointer operator->() const _NOEXCEPT {
2375    return __ptr_.first();
2376  }
2377  _LIBCPP_INLINE_VISIBILITY
2378  pointer get() const _NOEXCEPT {
2379    return __ptr_.first();
2380  }
2381  _LIBCPP_INLINE_VISIBILITY
2382  deleter_type& get_deleter() _NOEXCEPT {
2383    return __ptr_.second();
2384  }
2385  _LIBCPP_INLINE_VISIBILITY
2386  const deleter_type& get_deleter() const _NOEXCEPT {
2387    return __ptr_.second();
2388  }
2389  _LIBCPP_INLINE_VISIBILITY
2390  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2391    return __ptr_.first() != nullptr;
2392  }
2393
2394  _LIBCPP_INLINE_VISIBILITY
2395  pointer release() _NOEXCEPT {
2396    pointer __t = __ptr_.first();
2397    __ptr_.first() = pointer();
2398    return __t;
2399  }
2400
2401  _LIBCPP_INLINE_VISIBILITY
2402  void reset(pointer __p = pointer()) _NOEXCEPT {
2403    pointer __tmp = __ptr_.first();
2404    __ptr_.first() = __p;
2405    if (__tmp)
2406      __ptr_.second()(__tmp);
2407  }
2408
2409  _LIBCPP_INLINE_VISIBILITY
2410  void swap(unique_ptr& __u) _NOEXCEPT {
2411    __ptr_.swap(__u.__ptr_);
2412  }
2413};
2414
2415
2416template <class _Tp, class _Dp>
2417class _LIBCPP_UNIQUE_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS unique_ptr<_Tp[], _Dp> {
2418public:
2419  typedef _Tp element_type;
2420  typedef _Dp deleter_type;
2421  typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2422
2423private:
2424  __compressed_pair<pointer, deleter_type> __ptr_;
2425
2426  template <class _From>
2427  struct _CheckArrayPointerConversion : is_same<_From, pointer> {};
2428
2429  template <class _FromElem>
2430  struct _CheckArrayPointerConversion<_FromElem*>
2431      : integral_constant<bool,
2432          is_same<_FromElem*, pointer>::value ||
2433            (is_same<pointer, element_type*>::value &&
2434             is_convertible<_FromElem(*)[], element_type(*)[]>::value)
2435      >
2436  {};
2437
2438  typedef __unique_ptr_deleter_sfinae<_Dp> _DeleterSFINAE;
2439
2440  template <bool _Dummy>
2441  using _LValRefType _LIBCPP_NODEBUG_TYPE =
2442      typename __dependent_type<_DeleterSFINAE, _Dummy>::__lval_ref_type;
2443
2444  template <bool _Dummy>
2445  using _GoodRValRefType _LIBCPP_NODEBUG_TYPE =
2446      typename __dependent_type<_DeleterSFINAE, _Dummy>::__good_rval_ref_type;
2447
2448  template <bool _Dummy>
2449  using _BadRValRefType _LIBCPP_NODEBUG_TYPE =
2450      typename __dependent_type<_DeleterSFINAE, _Dummy>::__bad_rval_ref_type;
2451
2452  template <bool _Dummy, class _Deleter = typename __dependent_type<
2453                             __identity<deleter_type>, _Dummy>::type>
2454  using _EnableIfDeleterDefaultConstructible _LIBCPP_NODEBUG_TYPE  =
2455      typename enable_if<is_default_constructible<_Deleter>::value &&
2456                         !is_pointer<_Deleter>::value>::type;
2457
2458  template <class _ArgType>
2459  using _EnableIfDeleterConstructible _LIBCPP_NODEBUG_TYPE  =
2460      typename enable_if<is_constructible<deleter_type, _ArgType>::value>::type;
2461
2462  template <class _Pp>
2463  using _EnableIfPointerConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2464      _CheckArrayPointerConversion<_Pp>::value
2465  >::type;
2466
2467  template <class _UPtr, class _Up,
2468        class _ElemT = typename _UPtr::element_type>
2469  using _EnableIfMoveConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2470      is_array<_Up>::value &&
2471      is_same<pointer, element_type*>::value &&
2472      is_same<typename _UPtr::pointer, _ElemT*>::value &&
2473      is_convertible<_ElemT(*)[], element_type(*)[]>::value
2474    >::type;
2475
2476  template <class _UDel>
2477  using _EnableIfDeleterConvertible _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2478      (is_reference<_Dp>::value && is_same<_Dp, _UDel>::value) ||
2479      (!is_reference<_Dp>::value && is_convertible<_UDel, _Dp>::value)
2480    >::type;
2481
2482  template <class _UDel>
2483  using _EnableIfDeleterAssignable _LIBCPP_NODEBUG_TYPE  = typename enable_if<
2484      is_assignable<_Dp&, _UDel&&>::value
2485    >::type;
2486
2487public:
2488  template <bool _Dummy = true,
2489            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2490  _LIBCPP_INLINE_VISIBILITY
2491  _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2492
2493  template <bool _Dummy = true,
2494            class = _EnableIfDeleterDefaultConstructible<_Dummy> >
2495  _LIBCPP_INLINE_VISIBILITY
2496  _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT : __ptr_(pointer(), __default_init_tag()) {}
2497
2498  template <class _Pp, bool _Dummy = true,
2499            class = _EnableIfDeleterDefaultConstructible<_Dummy>,
2500            class = _EnableIfPointerConvertible<_Pp> >
2501  _LIBCPP_INLINE_VISIBILITY
2502  explicit unique_ptr(_Pp __p) _NOEXCEPT
2503      : __ptr_(__p, __default_init_tag()) {}
2504
2505  template <class _Pp, bool _Dummy = true,
2506            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> >,
2507            class = _EnableIfPointerConvertible<_Pp> >
2508  _LIBCPP_INLINE_VISIBILITY
2509  unique_ptr(_Pp __p, _LValRefType<_Dummy> __d) _NOEXCEPT
2510      : __ptr_(__p, __d) {}
2511
2512  template <bool _Dummy = true,
2513            class = _EnableIfDeleterConstructible<_LValRefType<_Dummy> > >
2514  _LIBCPP_INLINE_VISIBILITY
2515  unique_ptr(nullptr_t, _LValRefType<_Dummy> __d) _NOEXCEPT
2516      : __ptr_(nullptr, __d) {}
2517
2518  template <class _Pp, bool _Dummy = true,
2519            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> >,
2520            class = _EnableIfPointerConvertible<_Pp> >
2521  _LIBCPP_INLINE_VISIBILITY
2522  unique_ptr(_Pp __p, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2523      : __ptr_(__p, _VSTD::move(__d)) {
2524    static_assert(!is_reference<deleter_type>::value,
2525                  "rvalue deleter bound to reference");
2526  }
2527
2528  template <bool _Dummy = true,
2529            class = _EnableIfDeleterConstructible<_GoodRValRefType<_Dummy> > >
2530  _LIBCPP_INLINE_VISIBILITY
2531  unique_ptr(nullptr_t, _GoodRValRefType<_Dummy> __d) _NOEXCEPT
2532      : __ptr_(nullptr, _VSTD::move(__d)) {
2533    static_assert(!is_reference<deleter_type>::value,
2534                  "rvalue deleter bound to reference");
2535  }
2536
2537  template <class _Pp, bool _Dummy = true,
2538            class = _EnableIfDeleterConstructible<_BadRValRefType<_Dummy> >,
2539            class = _EnableIfPointerConvertible<_Pp> >
2540  _LIBCPP_INLINE_VISIBILITY
2541  unique_ptr(_Pp __p, _BadRValRefType<_Dummy> __d) = delete;
2542
2543  _LIBCPP_INLINE_VISIBILITY
2544  unique_ptr(unique_ptr&& __u) _NOEXCEPT
2545      : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {
2546  }
2547
2548  _LIBCPP_INLINE_VISIBILITY
2549  unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT {
2550    reset(__u.release());
2551    __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2552    return *this;
2553  }
2554
2555  template <class _Up, class _Ep,
2556      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2557      class = _EnableIfDeleterConvertible<_Ep>
2558  >
2559  _LIBCPP_INLINE_VISIBILITY
2560  unique_ptr(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2561      : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {
2562  }
2563
2564  template <class _Up, class _Ep,
2565      class = _EnableIfMoveConvertible<unique_ptr<_Up, _Ep>, _Up>,
2566      class = _EnableIfDeleterAssignable<_Ep>
2567  >
2568  _LIBCPP_INLINE_VISIBILITY
2569  unique_ptr&
2570  operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT {
2571    reset(__u.release());
2572    __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2573    return *this;
2574  }
2575
2576#ifdef _LIBCPP_CXX03_LANG
2577  unique_ptr(unique_ptr const&) = delete;
2578  unique_ptr& operator=(unique_ptr const&) = delete;
2579#endif
2580
2581public:
2582  _LIBCPP_INLINE_VISIBILITY
2583  ~unique_ptr() { reset(); }
2584
2585  _LIBCPP_INLINE_VISIBILITY
2586  unique_ptr& operator=(nullptr_t) _NOEXCEPT {
2587    reset();
2588    return *this;
2589  }
2590
2591  _LIBCPP_INLINE_VISIBILITY
2592  typename add_lvalue_reference<_Tp>::type
2593  operator[](size_t __i) const {
2594    return __ptr_.first()[__i];
2595  }
2596  _LIBCPP_INLINE_VISIBILITY
2597  pointer get() const _NOEXCEPT {
2598    return __ptr_.first();
2599  }
2600
2601  _LIBCPP_INLINE_VISIBILITY
2602  deleter_type& get_deleter() _NOEXCEPT {
2603    return __ptr_.second();
2604  }
2605
2606  _LIBCPP_INLINE_VISIBILITY
2607  const deleter_type& get_deleter() const _NOEXCEPT {
2608    return __ptr_.second();
2609  }
2610  _LIBCPP_INLINE_VISIBILITY
2611  _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {
2612    return __ptr_.first() != nullptr;
2613  }
2614
2615  _LIBCPP_INLINE_VISIBILITY
2616  pointer release() _NOEXCEPT {
2617    pointer __t = __ptr_.first();
2618    __ptr_.first() = pointer();
2619    return __t;
2620  }
2621
2622  template <class _Pp>
2623  _LIBCPP_INLINE_VISIBILITY
2624  typename enable_if<
2625      _CheckArrayPointerConversion<_Pp>::value
2626  >::type
2627  reset(_Pp __p) _NOEXCEPT {
2628    pointer __tmp = __ptr_.first();
2629    __ptr_.first() = __p;
2630    if (__tmp)
2631      __ptr_.second()(__tmp);
2632  }
2633
2634  _LIBCPP_INLINE_VISIBILITY
2635  void reset(nullptr_t = nullptr) _NOEXCEPT {
2636    pointer __tmp = __ptr_.first();
2637    __ptr_.first() = nullptr;
2638    if (__tmp)
2639      __ptr_.second()(__tmp);
2640  }
2641
2642  _LIBCPP_INLINE_VISIBILITY
2643  void swap(unique_ptr& __u) _NOEXCEPT {
2644    __ptr_.swap(__u.__ptr_);
2645  }
2646
2647};
2648
2649template <class _Tp, class _Dp>
2650inline _LIBCPP_INLINE_VISIBILITY
2651typename enable_if<
2652    __is_swappable<_Dp>::value,
2653    void
2654>::type
2655swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
2656
2657template <class _T1, class _D1, class _T2, class _D2>
2658inline _LIBCPP_INLINE_VISIBILITY
2659bool
2660operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
2661
2662template <class _T1, class _D1, class _T2, class _D2>
2663inline _LIBCPP_INLINE_VISIBILITY
2664bool
2665operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
2666
2667template <class _T1, class _D1, class _T2, class _D2>
2668inline _LIBCPP_INLINE_VISIBILITY
2669bool
2670operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
2671{
2672    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2673    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
2674    typedef typename common_type<_P1, _P2>::type _Vp;
2675    return less<_Vp>()(__x.get(), __y.get());
2676}
2677
2678template <class _T1, class _D1, class _T2, class _D2>
2679inline _LIBCPP_INLINE_VISIBILITY
2680bool
2681operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
2682
2683template <class _T1, class _D1, class _T2, class _D2>
2684inline _LIBCPP_INLINE_VISIBILITY
2685bool
2686operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
2687
2688template <class _T1, class _D1, class _T2, class _D2>
2689inline _LIBCPP_INLINE_VISIBILITY
2690bool
2691operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
2692
2693template <class _T1, class _D1>
2694inline _LIBCPP_INLINE_VISIBILITY
2695bool
2696operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2697{
2698    return !__x;
2699}
2700
2701template <class _T1, class _D1>
2702inline _LIBCPP_INLINE_VISIBILITY
2703bool
2704operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2705{
2706    return !__x;
2707}
2708
2709template <class _T1, class _D1>
2710inline _LIBCPP_INLINE_VISIBILITY
2711bool
2712operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
2713{
2714    return static_cast<bool>(__x);
2715}
2716
2717template <class _T1, class _D1>
2718inline _LIBCPP_INLINE_VISIBILITY
2719bool
2720operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
2721{
2722    return static_cast<bool>(__x);
2723}
2724
2725template <class _T1, class _D1>
2726inline _LIBCPP_INLINE_VISIBILITY
2727bool
2728operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2729{
2730    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2731    return less<_P1>()(__x.get(), nullptr);
2732}
2733
2734template <class _T1, class _D1>
2735inline _LIBCPP_INLINE_VISIBILITY
2736bool
2737operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2738{
2739    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2740    return less<_P1>()(nullptr, __x.get());
2741}
2742
2743template <class _T1, class _D1>
2744inline _LIBCPP_INLINE_VISIBILITY
2745bool
2746operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2747{
2748    return nullptr < __x;
2749}
2750
2751template <class _T1, class _D1>
2752inline _LIBCPP_INLINE_VISIBILITY
2753bool
2754operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2755{
2756    return __x < nullptr;
2757}
2758
2759template <class _T1, class _D1>
2760inline _LIBCPP_INLINE_VISIBILITY
2761bool
2762operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2763{
2764    return !(nullptr < __x);
2765}
2766
2767template <class _T1, class _D1>
2768inline _LIBCPP_INLINE_VISIBILITY
2769bool
2770operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2771{
2772    return !(__x < nullptr);
2773}
2774
2775template <class _T1, class _D1>
2776inline _LIBCPP_INLINE_VISIBILITY
2777bool
2778operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
2779{
2780    return !(__x < nullptr);
2781}
2782
2783template <class _T1, class _D1>
2784inline _LIBCPP_INLINE_VISIBILITY
2785bool
2786operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
2787{
2788    return !(nullptr < __x);
2789}
2790
2791#if _LIBCPP_STD_VER > 11
2792
2793template<class _Tp>
2794struct __unique_if
2795{
2796    typedef unique_ptr<_Tp> __unique_single;
2797};
2798
2799template<class _Tp>
2800struct __unique_if<_Tp[]>
2801{
2802    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
2803};
2804
2805template<class _Tp, size_t _Np>
2806struct __unique_if<_Tp[_Np]>
2807{
2808    typedef void __unique_array_known_bound;
2809};
2810
2811template<class _Tp, class... _Args>
2812inline _LIBCPP_INLINE_VISIBILITY
2813typename __unique_if<_Tp>::__unique_single
2814make_unique(_Args&&... __args)
2815{
2816    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
2817}
2818
2819template<class _Tp>
2820inline _LIBCPP_INLINE_VISIBILITY
2821typename __unique_if<_Tp>::__unique_array_unknown_bound
2822make_unique(size_t __n)
2823{
2824    typedef typename remove_extent<_Tp>::type _Up;
2825    return unique_ptr<_Tp>(new _Up[__n]());
2826}
2827
2828template<class _Tp, class... _Args>
2829    typename __unique_if<_Tp>::__unique_array_known_bound
2830    make_unique(_Args&&...) = delete;
2831
2832#endif  // _LIBCPP_STD_VER > 11
2833
2834template <class _Tp, class _Dp>
2835#ifdef _LIBCPP_CXX03_LANG
2836struct _LIBCPP_TEMPLATE_VIS hash<unique_ptr<_Tp, _Dp> >
2837#else
2838struct _LIBCPP_TEMPLATE_VIS hash<__enable_hash_helper<
2839    unique_ptr<_Tp, _Dp>, typename unique_ptr<_Tp, _Dp>::pointer> >
2840#endif
2841{
2842    typedef unique_ptr<_Tp, _Dp> argument_type;
2843    typedef size_t               result_type;
2844    _LIBCPP_INLINE_VISIBILITY
2845    result_type operator()(const argument_type& __ptr) const
2846    {
2847        typedef typename argument_type::pointer pointer;
2848        return hash<pointer>()(__ptr.get());
2849    }
2850};
2851
2852struct __destruct_n
2853{
2854private:
2855    size_t __size_;
2856
2857    template <class _Tp>
2858    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
2859        {for (size_t __i = 0; __i < __size_; ++__i, ++__p) __p->~_Tp();}
2860
2861    template <class _Tp>
2862    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
2863        {}
2864
2865    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
2866        {++__size_;}
2867    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
2868        {}
2869
2870    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
2871        {__size_ = __s;}
2872    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
2873        {}
2874public:
2875    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
2876        : __size_(__s) {}
2877
2878    template <class _Tp>
2879    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
2880        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
2881
2882    template <class _Tp>
2883    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
2884        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
2885
2886    template <class _Tp>
2887    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
2888        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
2889};
2890
2891template <class _Alloc>
2892class __allocator_destructor
2893{
2894    typedef _LIBCPP_NODEBUG_TYPE allocator_traits<_Alloc> __alloc_traits;
2895public:
2896    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::pointer pointer;
2897    typedef _LIBCPP_NODEBUG_TYPE typename __alloc_traits::size_type size_type;
2898private:
2899    _Alloc& __alloc_;
2900    size_type __s_;
2901public:
2902    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
2903             _NOEXCEPT
2904        : __alloc_(__a), __s_(__s) {}
2905    _LIBCPP_INLINE_VISIBILITY
2906    void operator()(pointer __p) _NOEXCEPT
2907        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
2908};
2909
2910template <class _InputIterator, class _ForwardIterator>
2911_ForwardIterator
2912uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
2913{
2914    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
2915#ifndef _LIBCPP_NO_EXCEPTIONS
2916    _ForwardIterator __s = __r;
2917    try
2918    {
2919#endif
2920        for (; __f != __l; ++__f, (void) ++__r)
2921            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
2922#ifndef _LIBCPP_NO_EXCEPTIONS
2923    }
2924    catch (...)
2925    {
2926        for (; __s != __r; ++__s)
2927            __s->~value_type();
2928        throw;
2929    }
2930#endif
2931    return __r;
2932}
2933
2934template <class _InputIterator, class _Size, class _ForwardIterator>
2935_ForwardIterator
2936uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
2937{
2938    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
2939#ifndef _LIBCPP_NO_EXCEPTIONS
2940    _ForwardIterator __s = __r;
2941    try
2942    {
2943#endif
2944        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
2945            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
2946#ifndef _LIBCPP_NO_EXCEPTIONS
2947    }
2948    catch (...)
2949    {
2950        for (; __s != __r; ++__s)
2951            __s->~value_type();
2952        throw;
2953    }
2954#endif
2955    return __r;
2956}
2957
2958template <class _ForwardIterator, class _Tp>
2959void
2960uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
2961{
2962    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
2963#ifndef _LIBCPP_NO_EXCEPTIONS
2964    _ForwardIterator __s = __f;
2965    try
2966    {
2967#endif
2968        for (; __f != __l; ++__f)
2969            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
2970#ifndef _LIBCPP_NO_EXCEPTIONS
2971    }
2972    catch (...)
2973    {
2974        for (; __s != __f; ++__s)
2975            __s->~value_type();
2976        throw;
2977    }
2978#endif
2979}
2980
2981template <class _ForwardIterator, class _Size, class _Tp>
2982_ForwardIterator
2983uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
2984{
2985    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
2986#ifndef _LIBCPP_NO_EXCEPTIONS
2987    _ForwardIterator __s = __f;
2988    try
2989    {
2990#endif
2991        for (; __n > 0; ++__f, (void) --__n)
2992            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
2993#ifndef _LIBCPP_NO_EXCEPTIONS
2994    }
2995    catch (...)
2996    {
2997        for (; __s != __f; ++__s)
2998            __s->~value_type();
2999        throw;
3000    }
3001#endif
3002    return __f;
3003}
3004
3005#if _LIBCPP_STD_VER > 14
3006
3007template <class _ForwardIterator>
3008inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
3009void destroy(_ForwardIterator __first, _ForwardIterator __last) {
3010    for (; __first != __last; ++__first)
3011        _VSTD::destroy_at(_VSTD::addressof(*__first));
3012}
3013
3014template <class _ForwardIterator, class _Size>
3015inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
3016_ForwardIterator destroy_n(_ForwardIterator __first, _Size __n) {
3017    for (; __n > 0; (void)++__first, --__n)
3018        _VSTD::destroy_at(_VSTD::addressof(*__first));
3019    return __first;
3020}
3021
3022template <class _ForwardIterator>
3023inline _LIBCPP_INLINE_VISIBILITY
3024void uninitialized_default_construct(_ForwardIterator __first, _ForwardIterator __last) {
3025    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3026    auto __idx = __first;
3027#ifndef _LIBCPP_NO_EXCEPTIONS
3028    try {
3029#endif
3030    for (; __idx != __last; ++__idx)
3031        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3032#ifndef _LIBCPP_NO_EXCEPTIONS
3033    } catch (...) {
3034        _VSTD::destroy(__first, __idx);
3035        throw;
3036    }
3037#endif
3038}
3039
3040template <class _ForwardIterator, class _Size>
3041inline _LIBCPP_INLINE_VISIBILITY
3042_ForwardIterator uninitialized_default_construct_n(_ForwardIterator __first, _Size __n) {
3043    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3044    auto __idx = __first;
3045#ifndef _LIBCPP_NO_EXCEPTIONS
3046    try {
3047#endif
3048    for (; __n > 0; (void)++__idx, --__n)
3049        ::new((void*)_VSTD::addressof(*__idx)) _Vt;
3050    return __idx;
3051#ifndef _LIBCPP_NO_EXCEPTIONS
3052    } catch (...) {
3053        _VSTD::destroy(__first, __idx);
3054        throw;
3055    }
3056#endif
3057}
3058
3059
3060template <class _ForwardIterator>
3061inline _LIBCPP_INLINE_VISIBILITY
3062void uninitialized_value_construct(_ForwardIterator __first, _ForwardIterator __last) {
3063    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3064    auto __idx = __first;
3065#ifndef _LIBCPP_NO_EXCEPTIONS
3066    try {
3067#endif
3068    for (; __idx != __last; ++__idx)
3069        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3070#ifndef _LIBCPP_NO_EXCEPTIONS
3071    } catch (...) {
3072        _VSTD::destroy(__first, __idx);
3073        throw;
3074    }
3075#endif
3076}
3077
3078template <class _ForwardIterator, class _Size>
3079inline _LIBCPP_INLINE_VISIBILITY
3080_ForwardIterator uninitialized_value_construct_n(_ForwardIterator __first, _Size __n) {
3081    using _Vt = typename iterator_traits<_ForwardIterator>::value_type;
3082    auto __idx = __first;
3083#ifndef _LIBCPP_NO_EXCEPTIONS
3084    try {
3085#endif
3086    for (; __n > 0; (void)++__idx, --__n)
3087        ::new((void*)_VSTD::addressof(*__idx)) _Vt();
3088    return __idx;
3089#ifndef _LIBCPP_NO_EXCEPTIONS
3090    } catch (...) {
3091        _VSTD::destroy(__first, __idx);
3092        throw;
3093    }
3094#endif
3095}
3096
3097
3098template <class _InputIt, class _ForwardIt>
3099inline _LIBCPP_INLINE_VISIBILITY
3100_ForwardIt uninitialized_move(_InputIt __first, _InputIt __last, _ForwardIt __first_res) {
3101    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3102    auto __idx = __first_res;
3103#ifndef _LIBCPP_NO_EXCEPTIONS
3104    try {
3105#endif
3106    for (; __first != __last; (void)++__idx, ++__first)
3107        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3108    return __idx;
3109#ifndef _LIBCPP_NO_EXCEPTIONS
3110    } catch (...) {
3111        _VSTD::destroy(__first_res, __idx);
3112        throw;
3113    }
3114#endif
3115}
3116
3117template <class _InputIt, class _Size, class _ForwardIt>
3118inline _LIBCPP_INLINE_VISIBILITY
3119pair<_InputIt, _ForwardIt>
3120uninitialized_move_n(_InputIt __first, _Size __n, _ForwardIt __first_res) {
3121    using _Vt = typename iterator_traits<_ForwardIt>::value_type;
3122    auto __idx = __first_res;
3123#ifndef _LIBCPP_NO_EXCEPTIONS
3124    try {
3125#endif
3126    for (; __n > 0; ++__idx, (void)++__first, --__n)
3127        ::new((void*)_VSTD::addressof(*__idx)) _Vt(std::move(*__first));
3128    return {__first, __idx};
3129#ifndef _LIBCPP_NO_EXCEPTIONS
3130    } catch (...) {
3131        _VSTD::destroy(__first_res, __idx);
3132        throw;
3133    }
3134#endif
3135}
3136
3137
3138#endif // _LIBCPP_STD_VER > 14
3139
3140// NOTE: Relaxed and acq/rel atomics (for increment and decrement respectively)
3141// should be sufficient for thread safety.
3142// See https://bugs.llvm.org/show_bug.cgi?id=22803
3143#if defined(__clang__) && __has_builtin(__atomic_add_fetch)          \
3144                       && defined(__ATOMIC_RELAXED)                  \
3145                       && defined(__ATOMIC_ACQ_REL)
3146#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3147#elif defined(_LIBCPP_COMPILER_GCC)
3148#   define _LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT
3149#endif
3150
3151template <class _Tp>
3152inline _LIBCPP_INLINE_VISIBILITY _Tp
3153__libcpp_atomic_refcount_increment(_Tp& __t) _NOEXCEPT
3154{
3155#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3156    return __atomic_add_fetch(&__t, 1, __ATOMIC_RELAXED);
3157#else
3158    return __t += 1;
3159#endif
3160}
3161
3162template <class _Tp>
3163inline _LIBCPP_INLINE_VISIBILITY _Tp
3164__libcpp_atomic_refcount_decrement(_Tp& __t) _NOEXCEPT
3165{
3166#if defined(_LIBCPP_HAS_BUILTIN_ATOMIC_SUPPORT) && !defined(_LIBCPP_HAS_NO_THREADS)
3167    return __atomic_add_fetch(&__t, -1, __ATOMIC_ACQ_REL);
3168#else
3169    return __t -= 1;
3170#endif
3171}
3172
3173class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
3174    : public std::exception
3175{
3176public:
3177    bad_weak_ptr() _NOEXCEPT = default;
3178    bad_weak_ptr(const bad_weak_ptr&) _NOEXCEPT = default;
3179    virtual ~bad_weak_ptr() _NOEXCEPT;
3180    virtual const char* what() const  _NOEXCEPT;
3181};
3182
3183_LIBCPP_NORETURN inline _LIBCPP_INLINE_VISIBILITY
3184void __throw_bad_weak_ptr()
3185{
3186#ifndef _LIBCPP_NO_EXCEPTIONS
3187    throw bad_weak_ptr();
3188#else
3189    _VSTD::abort();
3190#endif
3191}
3192
3193template<class _Tp> class _LIBCPP_TEMPLATE_VIS weak_ptr;
3194
3195class _LIBCPP_TYPE_VIS __shared_count
3196{
3197    __shared_count(const __shared_count&);
3198    __shared_count& operator=(const __shared_count&);
3199
3200protected:
3201    long __shared_owners_;
3202    virtual ~__shared_count();
3203private:
3204    virtual void __on_zero_shared() _NOEXCEPT = 0;
3205
3206public:
3207    _LIBCPP_INLINE_VISIBILITY
3208    explicit __shared_count(long __refs = 0) _NOEXCEPT
3209        : __shared_owners_(__refs) {}
3210
3211#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3212    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3213    void __add_shared() _NOEXCEPT;
3214    bool __release_shared() _NOEXCEPT;
3215#else
3216    _LIBCPP_INLINE_VISIBILITY
3217    void __add_shared() _NOEXCEPT {
3218      __libcpp_atomic_refcount_increment(__shared_owners_);
3219    }
3220    _LIBCPP_INLINE_VISIBILITY
3221    bool __release_shared() _NOEXCEPT {
3222      if (__libcpp_atomic_refcount_decrement(__shared_owners_) == -1) {
3223        __on_zero_shared();
3224        return true;
3225      }
3226      return false;
3227    }
3228#endif
3229    _LIBCPP_INLINE_VISIBILITY
3230    long use_count() const _NOEXCEPT {
3231        return __libcpp_relaxed_load(&__shared_owners_) + 1;
3232    }
3233};
3234
3235class _LIBCPP_TYPE_VIS __shared_weak_count
3236    : private __shared_count
3237{
3238    long __shared_weak_owners_;
3239
3240public:
3241    _LIBCPP_INLINE_VISIBILITY
3242    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
3243        : __shared_count(__refs),
3244          __shared_weak_owners_(__refs) {}
3245protected:
3246    virtual ~__shared_weak_count();
3247
3248public:
3249#if defined(_LIBCPP_BUILDING_LIBRARY) && \
3250    defined(_LIBCPP_DEPRECATED_ABI_LEGACY_LIBRARY_DEFINITIONS_FOR_INLINE_FUNCTIONS)
3251    void __add_shared() _NOEXCEPT;
3252    void __add_weak() _NOEXCEPT;
3253    void __release_shared() _NOEXCEPT;
3254#else
3255    _LIBCPP_INLINE_VISIBILITY
3256    void __add_shared() _NOEXCEPT {
3257      __shared_count::__add_shared();
3258    }
3259    _LIBCPP_INLINE_VISIBILITY
3260    void __add_weak() _NOEXCEPT {
3261      __libcpp_atomic_refcount_increment(__shared_weak_owners_);
3262    }
3263    _LIBCPP_INLINE_VISIBILITY
3264    void __release_shared() _NOEXCEPT {
3265      if (__shared_count::__release_shared())
3266        __release_weak();
3267    }
3268#endif
3269    void __release_weak() _NOEXCEPT;
3270    _LIBCPP_INLINE_VISIBILITY
3271    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
3272    __shared_weak_count* lock() _NOEXCEPT;
3273
3274    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3275private:
3276    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
3277};
3278
3279template <class _Tp, class _Dp, class _Alloc>
3280class __shared_ptr_pointer
3281    : public __shared_weak_count
3282{
3283    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
3284public:
3285    _LIBCPP_INLINE_VISIBILITY
3286    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
3287        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
3288
3289#ifndef _LIBCPP_NO_RTTI
3290    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3291#endif
3292
3293private:
3294    virtual void __on_zero_shared() _NOEXCEPT;
3295    virtual void __on_zero_shared_weak() _NOEXCEPT;
3296};
3297
3298#ifndef _LIBCPP_NO_RTTI
3299
3300template <class _Tp, class _Dp, class _Alloc>
3301const void*
3302__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
3303{
3304    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : nullptr;
3305}
3306
3307#endif  // _LIBCPP_NO_RTTI
3308
3309template <class _Tp, class _Dp, class _Alloc>
3310void
3311__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
3312{
3313    __data_.first().second()(__data_.first().first());
3314    __data_.first().second().~_Dp();
3315}
3316
3317template <class _Tp, class _Dp, class _Alloc>
3318void
3319__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3320{
3321    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
3322    typedef allocator_traits<_Al> _ATraits;
3323    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3324
3325    _Al __a(__data_.second());
3326    __data_.second().~_Alloc();
3327    __a.deallocate(_PTraits::pointer_to(*this), 1);
3328}
3329
3330template <class _Tp, class _Alloc>
3331class __shared_ptr_emplace
3332    : public __shared_weak_count
3333{
3334    __compressed_pair<_Alloc, _Tp> __data_;
3335public:
3336
3337    _LIBCPP_INLINE_VISIBILITY
3338    __shared_ptr_emplace(_Alloc __a)
3339        :  __data_(_VSTD::move(__a), __value_init_tag()) {}
3340
3341#ifndef _LIBCPP_CXX03_LANG
3342    template <class ..._Args>
3343        _LIBCPP_INLINE_VISIBILITY
3344        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
3345            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
3346                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
3347#else
3348    template <class ..._Args>
3349        _LIBCPP_INLINE_VISIBILITY
3350        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
3351            :  __data_(__a, _Tp(_VSTD::forward<_Args>(__args)...)) {}
3352#endif
3353
3354private:
3355    virtual void __on_zero_shared() _NOEXCEPT;
3356    virtual void __on_zero_shared_weak() _NOEXCEPT;
3357public:
3358    _LIBCPP_INLINE_VISIBILITY
3359    _Tp* get() _NOEXCEPT {return _VSTD::addressof(__data_.second());}
3360};
3361
3362template <class _Tp, class _Alloc>
3363void
3364__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
3365{
3366    __data_.second().~_Tp();
3367}
3368
3369template <class _Tp, class _Alloc>
3370void
3371__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3372{
3373    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
3374    typedef allocator_traits<_Al> _ATraits;
3375    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3376    _Al __a(__data_.first());
3377    __data_.first().~_Alloc();
3378    __a.deallocate(_PTraits::pointer_to(*this), 1);
3379}
3380
3381struct __shared_ptr_dummy_rebind_allocator_type;
3382template <>
3383class _LIBCPP_TEMPLATE_VIS allocator<__shared_ptr_dummy_rebind_allocator_type>
3384{
3385public:
3386    template <class _Other>
3387    struct rebind
3388    {
3389        typedef allocator<_Other> other;
3390    };
3391};
3392
3393template<class _Tp> class _LIBCPP_TEMPLATE_VIS enable_shared_from_this;
3394
3395template<class _Tp, class _Up>
3396struct __compatible_with
3397#if _LIBCPP_STD_VER > 14
3398    : is_convertible<remove_extent_t<_Tp>*, remove_extent_t<_Up>*> {};
3399#else
3400    : is_convertible<_Tp*, _Up*> {};
3401#endif // _LIBCPP_STD_VER > 14
3402
3403#if defined(_LIBCPP_ABI_ENABLE_SHARED_PTR_TRIVIAL_ABI)
3404#  define _LIBCPP_SHARED_PTR_TRIVIAL_ABI __attribute__((trivial_abi))
3405#else
3406#  define _LIBCPP_SHARED_PTR_TRIVIAL_ABI
3407#endif
3408
3409template<class _Tp>
3410class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS shared_ptr
3411{
3412public:
3413#if _LIBCPP_STD_VER > 14
3414    typedef weak_ptr<_Tp> weak_type;
3415    typedef remove_extent_t<_Tp> element_type;
3416#else
3417    typedef _Tp element_type;
3418#endif
3419
3420private:
3421    element_type*      __ptr_;
3422    __shared_weak_count* __cntrl_;
3423
3424    struct __nat {int __for_bool_;};
3425public:
3426    _LIBCPP_INLINE_VISIBILITY
3427    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
3428    _LIBCPP_INLINE_VISIBILITY
3429    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
3430    template<class _Yp>
3431        explicit shared_ptr(_Yp* __p,
3432                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat());
3433    template<class _Yp, class _Dp>
3434        shared_ptr(_Yp* __p, _Dp __d,
3435                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat());
3436    template<class _Yp, class _Dp, class _Alloc>
3437        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3438                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat());
3439    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
3440    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
3441    template<class _Yp> _LIBCPP_INLINE_VISIBILITY shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
3442    _LIBCPP_INLINE_VISIBILITY
3443    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
3444    template<class _Yp>
3445        _LIBCPP_INLINE_VISIBILITY
3446        shared_ptr(const shared_ptr<_Yp>& __r,
3447                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat())
3448                       _NOEXCEPT;
3449    _LIBCPP_INLINE_VISIBILITY
3450    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
3451    template<class _Yp> _LIBCPP_INLINE_VISIBILITY  shared_ptr(shared_ptr<_Yp>&& __r,
3452                   typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type = __nat())
3453                       _NOEXCEPT;
3454    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
3455                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type= __nat());
3456#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3457    template<class _Yp>
3458        shared_ptr(auto_ptr<_Yp>&& __r,
3459                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3460#endif
3461    template <class _Yp, class _Dp>
3462        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3463                   typename enable_if
3464                   <
3465                       !is_lvalue_reference<_Dp>::value &&
3466                       !is_array<_Yp>::value &&
3467                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3468                       __nat
3469                   >::type = __nat());
3470    template <class _Yp, class _Dp>
3471        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3472                   typename enable_if
3473                   <
3474                       is_lvalue_reference<_Dp>::value &&
3475                       !is_array<_Yp>::value &&
3476                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3477                       __nat
3478                   >::type = __nat());
3479
3480    ~shared_ptr();
3481
3482    _LIBCPP_INLINE_VISIBILITY
3483    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
3484    template<class _Yp>
3485        typename enable_if
3486        <
3487            __compatible_with<_Yp, element_type>::value,
3488            shared_ptr&
3489        >::type
3490        _LIBCPP_INLINE_VISIBILITY
3491        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
3492    _LIBCPP_INLINE_VISIBILITY
3493    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
3494    template<class _Yp>
3495        typename enable_if
3496        <
3497            __compatible_with<_Yp, element_type>::value,
3498            shared_ptr&
3499        >::type
3500        _LIBCPP_INLINE_VISIBILITY
3501        operator=(shared_ptr<_Yp>&& __r);
3502#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3503    template<class _Yp>
3504        _LIBCPP_INLINE_VISIBILITY
3505        typename enable_if
3506        <
3507            !is_array<_Yp>::value &&
3508            is_convertible<_Yp*, element_type*>::value,
3509            shared_ptr
3510        >::type&
3511        operator=(auto_ptr<_Yp>&& __r);
3512#endif
3513    template <class _Yp, class _Dp>
3514        typename enable_if
3515        <
3516            !is_array<_Yp>::value &&
3517            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3518            shared_ptr&
3519        >::type
3520        _LIBCPP_INLINE_VISIBILITY
3521        operator=(unique_ptr<_Yp, _Dp>&& __r);
3522
3523    _LIBCPP_INLINE_VISIBILITY
3524    void swap(shared_ptr& __r) _NOEXCEPT;
3525    _LIBCPP_INLINE_VISIBILITY
3526    void reset() _NOEXCEPT;
3527    template<class _Yp>
3528        typename enable_if
3529        <
3530            __compatible_with<_Yp, element_type>::value,
3531            void
3532        >::type
3533        _LIBCPP_INLINE_VISIBILITY
3534        reset(_Yp* __p);
3535    template<class _Yp, class _Dp>
3536        typename enable_if
3537        <
3538            __compatible_with<_Yp, element_type>::value,
3539            void
3540        >::type
3541        _LIBCPP_INLINE_VISIBILITY
3542        reset(_Yp* __p, _Dp __d);
3543    template<class _Yp, class _Dp, class _Alloc>
3544        typename enable_if
3545        <
3546            __compatible_with<_Yp, element_type>::value,
3547            void
3548        >::type
3549        _LIBCPP_INLINE_VISIBILITY
3550        reset(_Yp* __p, _Dp __d, _Alloc __a);
3551
3552    _LIBCPP_INLINE_VISIBILITY
3553    element_type* get() const _NOEXCEPT {return __ptr_;}
3554    _LIBCPP_INLINE_VISIBILITY
3555    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
3556        {return *__ptr_;}
3557    _LIBCPP_INLINE_VISIBILITY
3558    element_type* operator->() const _NOEXCEPT
3559    {
3560        static_assert(!_VSTD::is_array<_Tp>::value,
3561                      "std::shared_ptr<T>::operator-> is only valid when T is not an array type.");
3562        return __ptr_;
3563    }
3564    _LIBCPP_INLINE_VISIBILITY
3565    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
3566    _LIBCPP_INLINE_VISIBILITY
3567    bool unique() const _NOEXCEPT {return use_count() == 1;}
3568    _LIBCPP_INLINE_VISIBILITY
3569    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
3570    template <class _Up>
3571        _LIBCPP_INLINE_VISIBILITY
3572        bool owner_before(shared_ptr<_Up> const& __p) const _NOEXCEPT
3573        {return __cntrl_ < __p.__cntrl_;}
3574    template <class _Up>
3575        _LIBCPP_INLINE_VISIBILITY
3576        bool owner_before(weak_ptr<_Up> const& __p) const _NOEXCEPT
3577        {return __cntrl_ < __p.__cntrl_;}
3578    _LIBCPP_INLINE_VISIBILITY
3579    bool
3580    __owner_equivalent(const shared_ptr& __p) const
3581        {return __cntrl_ == __p.__cntrl_;}
3582
3583#if _LIBCPP_STD_VER > 14
3584    typename add_lvalue_reference<element_type>::type
3585    _LIBCPP_INLINE_VISIBILITY
3586    operator[](ptrdiff_t __i) const
3587    {
3588            static_assert(_VSTD::is_array<_Tp>::value,
3589                          "std::shared_ptr<T>::operator[] is only valid when T is an array type.");
3590            return __ptr_[__i];
3591    }
3592#endif
3593
3594#ifndef _LIBCPP_NO_RTTI
3595    template <class _Dp>
3596        _LIBCPP_INLINE_VISIBILITY
3597        _Dp* __get_deleter() const _NOEXCEPT
3598            {return static_cast<_Dp*>(__cntrl_
3599                    ? const_cast<void *>(__cntrl_->__get_deleter(typeid(_Dp)))
3600                      : nullptr);}
3601#endif  // _LIBCPP_NO_RTTI
3602
3603    template<class _Yp, class _CntrlBlk>
3604    static shared_ptr<_Tp>
3605    __create_with_control_block(_Yp* __p, _CntrlBlk* __cntrl) _NOEXCEPT
3606    {
3607        shared_ptr<_Tp> __r;
3608        __r.__ptr_ = __p;
3609        __r.__cntrl_ = __cntrl;
3610        __r.__enable_weak_this(__r.__ptr_, __r.__ptr_);
3611        return __r;
3612    }
3613
3614private:
3615    template <class _Yp, bool = is_function<_Yp>::value>
3616        struct __shared_ptr_default_allocator
3617        {
3618            typedef allocator<_Yp> type;
3619        };
3620
3621    template <class _Yp>
3622        struct __shared_ptr_default_allocator<_Yp, true>
3623        {
3624            typedef allocator<__shared_ptr_dummy_rebind_allocator_type> type;
3625        };
3626
3627    template <class _Yp, class _OrigPtr>
3628        _LIBCPP_INLINE_VISIBILITY
3629        typename enable_if<is_convertible<_OrigPtr*,
3630                                          const enable_shared_from_this<_Yp>*
3631        >::value,
3632            void>::type
3633        __enable_weak_this(const enable_shared_from_this<_Yp>* __e,
3634                           _OrigPtr* __ptr) _NOEXCEPT
3635        {
3636            typedef typename remove_cv<_Yp>::type _RawYp;
3637            if (__e && __e->__weak_this_.expired())
3638            {
3639                __e->__weak_this_ = shared_ptr<_RawYp>(*this,
3640                    const_cast<_RawYp*>(static_cast<const _Yp*>(__ptr)));
3641            }
3642        }
3643
3644    _LIBCPP_INLINE_VISIBILITY void __enable_weak_this(...) _NOEXCEPT {}
3645
3646    template <class, class _Yp>
3647        struct __shared_ptr_default_delete
3648            : default_delete<_Yp> {};
3649
3650    template <class _Yp, class _Un, size_t _Sz>
3651        struct __shared_ptr_default_delete<_Yp[_Sz], _Un>
3652            : default_delete<_Yp[]> {};
3653
3654    template <class _Yp, class _Un>
3655        struct __shared_ptr_default_delete<_Yp[], _Un>
3656            : default_delete<_Yp[]> {};
3657
3658    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
3659    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
3660};
3661
3662#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
3663template<class _Tp>
3664shared_ptr(weak_ptr<_Tp>) -> shared_ptr<_Tp>;
3665template<class _Tp, class _Dp>
3666shared_ptr(unique_ptr<_Tp, _Dp>) -> shared_ptr<_Tp>;
3667#endif
3668
3669template<class _Tp>
3670inline
3671_LIBCPP_CONSTEXPR
3672shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
3673    : __ptr_(0),
3674      __cntrl_(0)
3675{
3676}
3677
3678template<class _Tp>
3679inline
3680_LIBCPP_CONSTEXPR
3681shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
3682    : __ptr_(0),
3683      __cntrl_(0)
3684{
3685}
3686
3687template<class _Tp>
3688template<class _Yp>
3689shared_ptr<_Tp>::shared_ptr(_Yp* __p,
3690                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3691    : __ptr_(__p)
3692{
3693    unique_ptr<_Yp> __hold(__p);
3694    typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3695    typedef __shared_ptr_pointer<_Yp*, __shared_ptr_default_delete<_Tp, _Yp>, _AllocT > _CntrlBlk;
3696    __cntrl_ = new _CntrlBlk(__p, __shared_ptr_default_delete<_Tp, _Yp>(), _AllocT());
3697    __hold.release();
3698    __enable_weak_this(__p, __p);
3699}
3700
3701template<class _Tp>
3702template<class _Yp, class _Dp>
3703shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
3704                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3705    : __ptr_(__p)
3706{
3707#ifndef _LIBCPP_NO_EXCEPTIONS
3708    try
3709    {
3710#endif  // _LIBCPP_NO_EXCEPTIONS
3711        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3712        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
3713        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
3714        __enable_weak_this(__p, __p);
3715#ifndef _LIBCPP_NO_EXCEPTIONS
3716    }
3717    catch (...)
3718    {
3719        __d(__p);
3720        throw;
3721    }
3722#endif  // _LIBCPP_NO_EXCEPTIONS
3723}
3724
3725template<class _Tp>
3726template<class _Dp>
3727shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
3728    : __ptr_(0)
3729{
3730#ifndef _LIBCPP_NO_EXCEPTIONS
3731    try
3732    {
3733#endif  // _LIBCPP_NO_EXCEPTIONS
3734        typedef typename __shared_ptr_default_allocator<_Tp>::type _AllocT;
3735        typedef __shared_ptr_pointer<nullptr_t, _Dp, _AllocT > _CntrlBlk;
3736        __cntrl_ = new _CntrlBlk(__p, __d, _AllocT());
3737#ifndef _LIBCPP_NO_EXCEPTIONS
3738    }
3739    catch (...)
3740    {
3741        __d(__p);
3742        throw;
3743    }
3744#endif  // _LIBCPP_NO_EXCEPTIONS
3745}
3746
3747template<class _Tp>
3748template<class _Yp, class _Dp, class _Alloc>
3749shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3750                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3751    : __ptr_(__p)
3752{
3753#ifndef _LIBCPP_NO_EXCEPTIONS
3754    try
3755    {
3756#endif  // _LIBCPP_NO_EXCEPTIONS
3757        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
3758        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
3759        typedef __allocator_destructor<_A2> _D2;
3760        _A2 __a2(__a);
3761        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
3762        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
3763            _CntrlBlk(__p, __d, __a);
3764        __cntrl_ = _VSTD::addressof(*__hold2.release());
3765        __enable_weak_this(__p, __p);
3766#ifndef _LIBCPP_NO_EXCEPTIONS
3767    }
3768    catch (...)
3769    {
3770        __d(__p);
3771        throw;
3772    }
3773#endif  // _LIBCPP_NO_EXCEPTIONS
3774}
3775
3776template<class _Tp>
3777template<class _Dp, class _Alloc>
3778shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
3779    : __ptr_(0)
3780{
3781#ifndef _LIBCPP_NO_EXCEPTIONS
3782    try
3783    {
3784#endif  // _LIBCPP_NO_EXCEPTIONS
3785        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
3786        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
3787        typedef __allocator_destructor<_A2> _D2;
3788        _A2 __a2(__a);
3789        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
3790        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
3791            _CntrlBlk(__p, __d, __a);
3792        __cntrl_ = _VSTD::addressof(*__hold2.release());
3793#ifndef _LIBCPP_NO_EXCEPTIONS
3794    }
3795    catch (...)
3796    {
3797        __d(__p);
3798        throw;
3799    }
3800#endif  // _LIBCPP_NO_EXCEPTIONS
3801}
3802
3803template<class _Tp>
3804template<class _Yp>
3805inline
3806shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
3807    : __ptr_(__p),
3808      __cntrl_(__r.__cntrl_)
3809{
3810    if (__cntrl_)
3811        __cntrl_->__add_shared();
3812}
3813
3814template<class _Tp>
3815inline
3816shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
3817    : __ptr_(__r.__ptr_),
3818      __cntrl_(__r.__cntrl_)
3819{
3820    if (__cntrl_)
3821        __cntrl_->__add_shared();
3822}
3823
3824template<class _Tp>
3825template<class _Yp>
3826inline
3827shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
3828                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3829         _NOEXCEPT
3830    : __ptr_(__r.__ptr_),
3831      __cntrl_(__r.__cntrl_)
3832{
3833    if (__cntrl_)
3834        __cntrl_->__add_shared();
3835}
3836
3837template<class _Tp>
3838inline
3839shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
3840    : __ptr_(__r.__ptr_),
3841      __cntrl_(__r.__cntrl_)
3842{
3843    __r.__ptr_ = 0;
3844    __r.__cntrl_ = 0;
3845}
3846
3847template<class _Tp>
3848template<class _Yp>
3849inline
3850shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
3851                            typename enable_if<__compatible_with<_Yp, element_type>::value, __nat>::type)
3852         _NOEXCEPT
3853    : __ptr_(__r.__ptr_),
3854      __cntrl_(__r.__cntrl_)
3855{
3856    __r.__ptr_ = 0;
3857    __r.__cntrl_ = 0;
3858}
3859
3860#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3861template<class _Tp>
3862template<class _Yp>
3863shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
3864                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
3865    : __ptr_(__r.get())
3866{
3867    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
3868    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
3869    __enable_weak_this(__r.get(), __r.get());
3870    __r.release();
3871}
3872#endif
3873
3874template<class _Tp>
3875template <class _Yp, class _Dp>
3876shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
3877                            typename enable_if
3878                            <
3879                                !is_lvalue_reference<_Dp>::value &&
3880                                !is_array<_Yp>::value &&
3881                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3882                                __nat
3883                            >::type)
3884    : __ptr_(__r.get())
3885{
3886#if _LIBCPP_STD_VER > 11
3887    if (__ptr_ == nullptr)
3888        __cntrl_ = nullptr;
3889    else
3890#endif
3891    {
3892        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3893        typedef __shared_ptr_pointer<_Yp*, _Dp, _AllocT > _CntrlBlk;
3894        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), _AllocT());
3895        __enable_weak_this(__r.get(), __r.get());
3896    }
3897    __r.release();
3898}
3899
3900template<class _Tp>
3901template <class _Yp, class _Dp>
3902shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
3903                            typename enable_if
3904                            <
3905                                is_lvalue_reference<_Dp>::value &&
3906                                !is_array<_Yp>::value &&
3907                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3908                                __nat
3909                            >::type)
3910    : __ptr_(__r.get())
3911{
3912#if _LIBCPP_STD_VER > 11
3913    if (__ptr_ == nullptr)
3914        __cntrl_ = nullptr;
3915    else
3916#endif
3917    {
3918        typedef typename __shared_ptr_default_allocator<_Yp>::type _AllocT;
3919        typedef __shared_ptr_pointer<_Yp*,
3920                                     reference_wrapper<typename remove_reference<_Dp>::type>,
3921                                     _AllocT > _CntrlBlk;
3922        __cntrl_ = new _CntrlBlk(__r.get(), _VSTD::ref(__r.get_deleter()), _AllocT());
3923        __enable_weak_this(__r.get(), __r.get());
3924    }
3925    __r.release();
3926}
3927
3928template<class _Tp>
3929shared_ptr<_Tp>::~shared_ptr()
3930{
3931    if (__cntrl_)
3932        __cntrl_->__release_shared();
3933}
3934
3935template<class _Tp>
3936inline
3937shared_ptr<_Tp>&
3938shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
3939{
3940    shared_ptr(__r).swap(*this);
3941    return *this;
3942}
3943
3944template<class _Tp>
3945template<class _Yp>
3946inline
3947typename enable_if
3948<
3949    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
3950    shared_ptr<_Tp>&
3951>::type
3952shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
3953{
3954    shared_ptr(__r).swap(*this);
3955    return *this;
3956}
3957
3958template<class _Tp>
3959inline
3960shared_ptr<_Tp>&
3961shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
3962{
3963    shared_ptr(_VSTD::move(__r)).swap(*this);
3964    return *this;
3965}
3966
3967template<class _Tp>
3968template<class _Yp>
3969inline
3970typename enable_if
3971<
3972    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
3973    shared_ptr<_Tp>&
3974>::type
3975shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
3976{
3977    shared_ptr(_VSTD::move(__r)).swap(*this);
3978    return *this;
3979}
3980
3981#if _LIBCPP_STD_VER <= 14 || defined(_LIBCPP_ENABLE_CXX17_REMOVED_AUTO_PTR)
3982template<class _Tp>
3983template<class _Yp>
3984inline
3985typename enable_if
3986<
3987    !is_array<_Yp>::value &&
3988    is_convertible<_Yp*, typename shared_ptr<_Tp>::element_type*>::value,
3989    shared_ptr<_Tp>
3990>::type&
3991shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
3992{
3993    shared_ptr(_VSTD::move(__r)).swap(*this);
3994    return *this;
3995}
3996#endif
3997
3998template<class _Tp>
3999template <class _Yp, class _Dp>
4000inline
4001typename enable_if
4002<
4003    !is_array<_Yp>::value &&
4004    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer,
4005                   typename shared_ptr<_Tp>::element_type*>::value,
4006    shared_ptr<_Tp>&
4007>::type
4008shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
4009{
4010    shared_ptr(_VSTD::move(__r)).swap(*this);
4011    return *this;
4012}
4013
4014template<class _Tp>
4015inline
4016void
4017shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
4018{
4019    _VSTD::swap(__ptr_, __r.__ptr_);
4020    _VSTD::swap(__cntrl_, __r.__cntrl_);
4021}
4022
4023template<class _Tp>
4024inline
4025void
4026shared_ptr<_Tp>::reset() _NOEXCEPT
4027{
4028    shared_ptr().swap(*this);
4029}
4030
4031template<class _Tp>
4032template<class _Yp>
4033inline
4034typename enable_if
4035<
4036    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4037    void
4038>::type
4039shared_ptr<_Tp>::reset(_Yp* __p)
4040{
4041    shared_ptr(__p).swap(*this);
4042}
4043
4044template<class _Tp>
4045template<class _Yp, class _Dp>
4046inline
4047typename enable_if
4048<
4049    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4050    void
4051>::type
4052shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
4053{
4054    shared_ptr(__p, __d).swap(*this);
4055}
4056
4057template<class _Tp>
4058template<class _Yp, class _Dp, class _Alloc>
4059inline
4060typename enable_if
4061<
4062    __compatible_with<_Yp, typename shared_ptr<_Tp>::element_type>::value,
4063    void
4064>::type
4065shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
4066{
4067    shared_ptr(__p, __d, __a).swap(*this);
4068}
4069
4070template<class _Tp, class ..._Args>
4071inline _LIBCPP_INLINE_VISIBILITY
4072typename enable_if
4073<
4074    !is_array<_Tp>::value,
4075    shared_ptr<_Tp>
4076>::type
4077make_shared(_Args&& ...__args)
4078{
4079    static_assert(is_constructible<_Tp, _Args...>::value, "Can't construct object in make_shared");
4080    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4081    typedef allocator<_CntrlBlk> _A2;
4082    typedef __allocator_destructor<_A2> _D2;
4083
4084    _A2 __a2;
4085    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4086    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
4087
4088    _Tp *__ptr = __hold2.get()->get();
4089    return shared_ptr<_Tp>::__create_with_control_block(__ptr, __hold2.release());
4090}
4091
4092template<class _Tp, class _Alloc, class ..._Args>
4093inline _LIBCPP_INLINE_VISIBILITY
4094typename enable_if
4095<
4096    !is_array<_Tp>::value,
4097    shared_ptr<_Tp>
4098>::type
4099allocate_shared(const _Alloc& __a, _Args&& ...__args)
4100{
4101    static_assert( is_constructible<_Tp, _Args...>::value, "Can't construct object in allocate_shared");
4102
4103    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4104    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4105    typedef __allocator_destructor<_A2> _D2;
4106
4107    _A2 __a2(__a);
4108    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4109    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4110        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
4111
4112    typename shared_ptr<_Tp>::element_type *__p = __hold2.get()->get();
4113    return shared_ptr<_Tp>::__create_with_control_block(__p, _VSTD::addressof(*__hold2.release()));
4114}
4115
4116template<class _Tp, class _Up>
4117inline _LIBCPP_INLINE_VISIBILITY
4118bool
4119operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4120{
4121    return __x.get() == __y.get();
4122}
4123
4124template<class _Tp, class _Up>
4125inline _LIBCPP_INLINE_VISIBILITY
4126bool
4127operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4128{
4129    return !(__x == __y);
4130}
4131
4132template<class _Tp, class _Up>
4133inline _LIBCPP_INLINE_VISIBILITY
4134bool
4135operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4136{
4137#if _LIBCPP_STD_VER <= 11
4138    typedef typename common_type<_Tp*, _Up*>::type _Vp;
4139    return less<_Vp>()(__x.get(), __y.get());
4140#else
4141    return less<>()(__x.get(), __y.get());
4142#endif
4143
4144}
4145
4146template<class _Tp, class _Up>
4147inline _LIBCPP_INLINE_VISIBILITY
4148bool
4149operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4150{
4151    return __y < __x;
4152}
4153
4154template<class _Tp, class _Up>
4155inline _LIBCPP_INLINE_VISIBILITY
4156bool
4157operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4158{
4159    return !(__y < __x);
4160}
4161
4162template<class _Tp, class _Up>
4163inline _LIBCPP_INLINE_VISIBILITY
4164bool
4165operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4166{
4167    return !(__x < __y);
4168}
4169
4170template<class _Tp>
4171inline _LIBCPP_INLINE_VISIBILITY
4172bool
4173operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4174{
4175    return !__x;
4176}
4177
4178template<class _Tp>
4179inline _LIBCPP_INLINE_VISIBILITY
4180bool
4181operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4182{
4183    return !__x;
4184}
4185
4186template<class _Tp>
4187inline _LIBCPP_INLINE_VISIBILITY
4188bool
4189operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4190{
4191    return static_cast<bool>(__x);
4192}
4193
4194template<class _Tp>
4195inline _LIBCPP_INLINE_VISIBILITY
4196bool
4197operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4198{
4199    return static_cast<bool>(__x);
4200}
4201
4202template<class _Tp>
4203inline _LIBCPP_INLINE_VISIBILITY
4204bool
4205operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4206{
4207    return less<_Tp*>()(__x.get(), nullptr);
4208}
4209
4210template<class _Tp>
4211inline _LIBCPP_INLINE_VISIBILITY
4212bool
4213operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4214{
4215    return less<_Tp*>()(nullptr, __x.get());
4216}
4217
4218template<class _Tp>
4219inline _LIBCPP_INLINE_VISIBILITY
4220bool
4221operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4222{
4223    return nullptr < __x;
4224}
4225
4226template<class _Tp>
4227inline _LIBCPP_INLINE_VISIBILITY
4228bool
4229operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4230{
4231    return __x < nullptr;
4232}
4233
4234template<class _Tp>
4235inline _LIBCPP_INLINE_VISIBILITY
4236bool
4237operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4238{
4239    return !(nullptr < __x);
4240}
4241
4242template<class _Tp>
4243inline _LIBCPP_INLINE_VISIBILITY
4244bool
4245operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4246{
4247    return !(__x < nullptr);
4248}
4249
4250template<class _Tp>
4251inline _LIBCPP_INLINE_VISIBILITY
4252bool
4253operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4254{
4255    return !(__x < nullptr);
4256}
4257
4258template<class _Tp>
4259inline _LIBCPP_INLINE_VISIBILITY
4260bool
4261operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4262{
4263    return !(nullptr < __x);
4264}
4265
4266template<class _Tp>
4267inline _LIBCPP_INLINE_VISIBILITY
4268void
4269swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
4270{
4271    __x.swap(__y);
4272}
4273
4274template<class _Tp, class _Up>
4275inline _LIBCPP_INLINE_VISIBILITY
4276shared_ptr<_Tp>
4277static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4278{
4279    return shared_ptr<_Tp>(__r,
4280                           static_cast<
4281                               typename shared_ptr<_Tp>::element_type*>(__r.get()));
4282}
4283
4284template<class _Tp, class _Up>
4285inline _LIBCPP_INLINE_VISIBILITY
4286shared_ptr<_Tp>
4287dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4288{
4289    typedef typename shared_ptr<_Tp>::element_type _ET;
4290    _ET* __p = dynamic_cast<_ET*>(__r.get());
4291    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
4292}
4293
4294template<class _Tp, class _Up>
4295shared_ptr<_Tp>
4296const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4297{
4298    typedef typename shared_ptr<_Tp>::element_type _RTp;
4299    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
4300}
4301
4302template<class _Tp, class _Up>
4303shared_ptr<_Tp>
4304reinterpret_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
4305{
4306    return shared_ptr<_Tp>(__r,
4307                           reinterpret_cast<
4308                               typename shared_ptr<_Tp>::element_type*>(__r.get()));
4309}
4310
4311#ifndef _LIBCPP_NO_RTTI
4312
4313template<class _Dp, class _Tp>
4314inline _LIBCPP_INLINE_VISIBILITY
4315_Dp*
4316get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
4317{
4318    return __p.template __get_deleter<_Dp>();
4319}
4320
4321#endif  // _LIBCPP_NO_RTTI
4322
4323template<class _Tp>
4324class _LIBCPP_SHARED_PTR_TRIVIAL_ABI _LIBCPP_TEMPLATE_VIS weak_ptr
4325{
4326public:
4327    typedef _Tp element_type;
4328private:
4329    element_type*        __ptr_;
4330    __shared_weak_count* __cntrl_;
4331
4332public:
4333    _LIBCPP_INLINE_VISIBILITY
4334    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
4335    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(shared_ptr<_Yp> const& __r,
4336                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4337                        _NOEXCEPT;
4338    _LIBCPP_INLINE_VISIBILITY
4339    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
4340    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp> const& __r,
4341                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4342                         _NOEXCEPT;
4343
4344    _LIBCPP_INLINE_VISIBILITY
4345    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
4346    template<class _Yp> _LIBCPP_INLINE_VISIBILITY weak_ptr(weak_ptr<_Yp>&& __r,
4347                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
4348                         _NOEXCEPT;
4349    ~weak_ptr();
4350
4351    _LIBCPP_INLINE_VISIBILITY
4352    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
4353    template<class _Yp>
4354        typename enable_if
4355        <
4356            is_convertible<_Yp*, element_type*>::value,
4357            weak_ptr&
4358        >::type
4359        _LIBCPP_INLINE_VISIBILITY
4360        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
4361
4362    _LIBCPP_INLINE_VISIBILITY
4363    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
4364    template<class _Yp>
4365        typename enable_if
4366        <
4367            is_convertible<_Yp*, element_type*>::value,
4368            weak_ptr&
4369        >::type
4370        _LIBCPP_INLINE_VISIBILITY
4371        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
4372
4373    template<class _Yp>
4374        typename enable_if
4375        <
4376            is_convertible<_Yp*, element_type*>::value,
4377            weak_ptr&
4378        >::type
4379        _LIBCPP_INLINE_VISIBILITY
4380        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
4381
4382    _LIBCPP_INLINE_VISIBILITY
4383    void swap(weak_ptr& __r) _NOEXCEPT;
4384    _LIBCPP_INLINE_VISIBILITY
4385    void reset() _NOEXCEPT;
4386
4387    _LIBCPP_INLINE_VISIBILITY
4388    long use_count() const _NOEXCEPT
4389        {return __cntrl_ ? __cntrl_->use_count() : 0;}
4390    _LIBCPP_INLINE_VISIBILITY
4391    bool expired() const _NOEXCEPT
4392        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
4393    shared_ptr<_Tp> lock() const _NOEXCEPT;
4394    template<class _Up>
4395        _LIBCPP_INLINE_VISIBILITY
4396        bool owner_before(const shared_ptr<_Up>& __r) const _NOEXCEPT
4397        {return __cntrl_ < __r.__cntrl_;}
4398    template<class _Up>
4399        _LIBCPP_INLINE_VISIBILITY
4400        bool owner_before(const weak_ptr<_Up>& __r) const _NOEXCEPT
4401        {return __cntrl_ < __r.__cntrl_;}
4402
4403    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS weak_ptr;
4404    template <class _Up> friend class _LIBCPP_TEMPLATE_VIS shared_ptr;
4405};
4406
4407#ifndef _LIBCPP_HAS_NO_DEDUCTION_GUIDES
4408template<class _Tp>
4409weak_ptr(shared_ptr<_Tp>) -> weak_ptr<_Tp>;
4410#endif
4411
4412template<class _Tp>
4413inline
4414_LIBCPP_CONSTEXPR
4415weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
4416    : __ptr_(0),
4417      __cntrl_(0)
4418{
4419}
4420
4421template<class _Tp>
4422inline
4423weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
4424    : __ptr_(__r.__ptr_),
4425      __cntrl_(__r.__cntrl_)
4426{
4427    if (__cntrl_)
4428        __cntrl_->__add_weak();
4429}
4430
4431template<class _Tp>
4432template<class _Yp>
4433inline
4434weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
4435                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4436                         _NOEXCEPT
4437    : __ptr_(__r.__ptr_),
4438      __cntrl_(__r.__cntrl_)
4439{
4440    if (__cntrl_)
4441        __cntrl_->__add_weak();
4442}
4443
4444template<class _Tp>
4445template<class _Yp>
4446inline
4447weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
4448                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4449         _NOEXCEPT
4450    : __ptr_(__r.__ptr_),
4451      __cntrl_(__r.__cntrl_)
4452{
4453    if (__cntrl_)
4454        __cntrl_->__add_weak();
4455}
4456
4457template<class _Tp>
4458inline
4459weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
4460    : __ptr_(__r.__ptr_),
4461      __cntrl_(__r.__cntrl_)
4462{
4463    __r.__ptr_ = 0;
4464    __r.__cntrl_ = 0;
4465}
4466
4467template<class _Tp>
4468template<class _Yp>
4469inline
4470weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
4471                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
4472         _NOEXCEPT
4473    : __ptr_(__r.__ptr_),
4474      __cntrl_(__r.__cntrl_)
4475{
4476    __r.__ptr_ = 0;
4477    __r.__cntrl_ = 0;
4478}
4479
4480template<class _Tp>
4481weak_ptr<_Tp>::~weak_ptr()
4482{
4483    if (__cntrl_)
4484        __cntrl_->__release_weak();
4485}
4486
4487template<class _Tp>
4488inline
4489weak_ptr<_Tp>&
4490weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
4491{
4492    weak_ptr(__r).swap(*this);
4493    return *this;
4494}
4495
4496template<class _Tp>
4497template<class _Yp>
4498inline
4499typename enable_if
4500<
4501    is_convertible<_Yp*, _Tp*>::value,
4502    weak_ptr<_Tp>&
4503>::type
4504weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
4505{
4506    weak_ptr(__r).swap(*this);
4507    return *this;
4508}
4509
4510template<class _Tp>
4511inline
4512weak_ptr<_Tp>&
4513weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
4514{
4515    weak_ptr(_VSTD::move(__r)).swap(*this);
4516    return *this;
4517}
4518
4519template<class _Tp>
4520template<class _Yp>
4521inline
4522typename enable_if
4523<
4524    is_convertible<_Yp*, _Tp*>::value,
4525    weak_ptr<_Tp>&
4526>::type
4527weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
4528{
4529    weak_ptr(_VSTD::move(__r)).swap(*this);
4530    return *this;
4531}
4532
4533template<class _Tp>
4534template<class _Yp>
4535inline
4536typename enable_if
4537<
4538    is_convertible<_Yp*, _Tp*>::value,
4539    weak_ptr<_Tp>&
4540>::type
4541weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
4542{
4543    weak_ptr(__r).swap(*this);
4544    return *this;
4545}
4546
4547template<class _Tp>
4548inline
4549void
4550weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
4551{
4552    _VSTD::swap(__ptr_, __r.__ptr_);
4553    _VSTD::swap(__cntrl_, __r.__cntrl_);
4554}
4555
4556template<class _Tp>
4557inline _LIBCPP_INLINE_VISIBILITY
4558void
4559swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
4560{
4561    __x.swap(__y);
4562}
4563
4564template<class _Tp>
4565inline
4566void
4567weak_ptr<_Tp>::reset() _NOEXCEPT
4568{
4569    weak_ptr().swap(*this);
4570}
4571
4572template<class _Tp>
4573template<class _Yp>
4574shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
4575                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4576    : __ptr_(__r.__ptr_),
4577      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
4578{
4579    if (__cntrl_ == 0)
4580        __throw_bad_weak_ptr();
4581}
4582
4583template<class _Tp>
4584shared_ptr<_Tp>
4585weak_ptr<_Tp>::lock() const _NOEXCEPT
4586{
4587    shared_ptr<_Tp> __r;
4588    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
4589    if (__r.__cntrl_)
4590        __r.__ptr_ = __ptr_;
4591    return __r;
4592}
4593
4594#if _LIBCPP_STD_VER > 14
4595template <class _Tp = void> struct owner_less;
4596#else
4597template <class _Tp> struct owner_less;
4598#endif
4599
4600template <class _Tp>
4601struct _LIBCPP_TEMPLATE_VIS owner_less<shared_ptr<_Tp> >
4602    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
4603{
4604    typedef bool result_type;
4605    _LIBCPP_INLINE_VISIBILITY
4606    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4607        {return __x.owner_before(__y);}
4608    _LIBCPP_INLINE_VISIBILITY
4609    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4610        {return __x.owner_before(__y);}
4611    _LIBCPP_INLINE_VISIBILITY
4612    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4613        {return __x.owner_before(__y);}
4614};
4615
4616template <class _Tp>
4617struct _LIBCPP_TEMPLATE_VIS owner_less<weak_ptr<_Tp> >
4618    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
4619{
4620    typedef bool result_type;
4621    _LIBCPP_INLINE_VISIBILITY
4622    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4623        {return __x.owner_before(__y);}
4624    _LIBCPP_INLINE_VISIBILITY
4625    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const _NOEXCEPT
4626        {return __x.owner_before(__y);}
4627    _LIBCPP_INLINE_VISIBILITY
4628    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const _NOEXCEPT
4629        {return __x.owner_before(__y);}
4630};
4631
4632#if _LIBCPP_STD_VER > 14
4633template <>
4634struct _LIBCPP_TEMPLATE_VIS owner_less<void>
4635{
4636    template <class _Tp, class _Up>
4637    _LIBCPP_INLINE_VISIBILITY
4638    bool operator()( shared_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
4639        {return __x.owner_before(__y);}
4640    template <class _Tp, class _Up>
4641    _LIBCPP_INLINE_VISIBILITY
4642    bool operator()( shared_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
4643        {return __x.owner_before(__y);}
4644    template <class _Tp, class _Up>
4645    _LIBCPP_INLINE_VISIBILITY
4646    bool operator()(   weak_ptr<_Tp> const& __x, shared_ptr<_Up> const& __y) const _NOEXCEPT
4647        {return __x.owner_before(__y);}
4648    template <class _Tp, class _Up>
4649    _LIBCPP_INLINE_VISIBILITY
4650    bool operator()(   weak_ptr<_Tp> const& __x,   weak_ptr<_Up> const& __y) const _NOEXCEPT
4651        {return __x.owner_before(__y);}
4652    typedef void is_transparent;
4653};
4654#endif
4655
4656template<class _Tp>
4657class _LIBCPP_TEMPLATE_VIS enable_shared_from_this
4658{
4659    mutable weak_ptr<_Tp> __weak_this_;
4660protected:
4661    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
4662    enable_shared_from_this() _NOEXCEPT {}
4663    _LIBCPP_INLINE_VISIBILITY
4664    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
4665    _LIBCPP_INLINE_VISIBILITY
4666    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
4667        {return *this;}
4668    _LIBCPP_INLINE_VISIBILITY
4669    ~enable_shared_from_this() {}
4670public:
4671    _LIBCPP_INLINE_VISIBILITY
4672    shared_ptr<_Tp> shared_from_this()
4673        {return shared_ptr<_Tp>(__weak_this_);}
4674    _LIBCPP_INLINE_VISIBILITY
4675    shared_ptr<_Tp const> shared_from_this() const
4676        {return shared_ptr<const _Tp>(__weak_this_);}
4677
4678#if _LIBCPP_STD_VER > 14
4679    _LIBCPP_INLINE_VISIBILITY
4680    weak_ptr<_Tp> weak_from_this() _NOEXCEPT
4681       { return __weak_this_; }
4682
4683    _LIBCPP_INLINE_VISIBILITY
4684    weak_ptr<const _Tp> weak_from_this() const _NOEXCEPT
4685        { return __weak_this_; }
4686#endif // _LIBCPP_STD_VER > 14
4687
4688    template <class _Up> friend class shared_ptr;
4689};
4690
4691template <class _Tp>
4692struct _LIBCPP_TEMPLATE_VIS hash<shared_ptr<_Tp> >
4693{
4694    typedef shared_ptr<_Tp>      argument_type;
4695    typedef size_t               result_type;
4696
4697    _LIBCPP_INLINE_VISIBILITY
4698    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
4699    {
4700        return hash<typename shared_ptr<_Tp>::element_type*>()(__ptr.get());
4701    }
4702};
4703
4704template<class _CharT, class _Traits, class _Yp>
4705inline _LIBCPP_INLINE_VISIBILITY
4706basic_ostream<_CharT, _Traits>&
4707operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
4708
4709
4710#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
4711
4712class _LIBCPP_TYPE_VIS __sp_mut
4713{
4714    void* __lx;
4715public:
4716    void lock() _NOEXCEPT;
4717    void unlock() _NOEXCEPT;
4718
4719private:
4720    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
4721    __sp_mut(const __sp_mut&);
4722    __sp_mut& operator=(const __sp_mut&);
4723
4724    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
4725};
4726
4727_LIBCPP_FUNC_VIS _LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4728__sp_mut& __get_sp_mut(const void*);
4729
4730template <class _Tp>
4731inline _LIBCPP_INLINE_VISIBILITY
4732bool
4733atomic_is_lock_free(const shared_ptr<_Tp>*)
4734{
4735    return false;
4736}
4737
4738template <class _Tp>
4739_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4740shared_ptr<_Tp>
4741atomic_load(const shared_ptr<_Tp>* __p)
4742{
4743    __sp_mut& __m = __get_sp_mut(__p);
4744    __m.lock();
4745    shared_ptr<_Tp> __q = *__p;
4746    __m.unlock();
4747    return __q;
4748}
4749
4750template <class _Tp>
4751inline _LIBCPP_INLINE_VISIBILITY
4752_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4753shared_ptr<_Tp>
4754atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
4755{
4756    return atomic_load(__p);
4757}
4758
4759template <class _Tp>
4760_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4761void
4762atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
4763{
4764    __sp_mut& __m = __get_sp_mut(__p);
4765    __m.lock();
4766    __p->swap(__r);
4767    __m.unlock();
4768}
4769
4770template <class _Tp>
4771inline _LIBCPP_INLINE_VISIBILITY
4772_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4773void
4774atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
4775{
4776    atomic_store(__p, __r);
4777}
4778
4779template <class _Tp>
4780_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4781shared_ptr<_Tp>
4782atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
4783{
4784    __sp_mut& __m = __get_sp_mut(__p);
4785    __m.lock();
4786    __p->swap(__r);
4787    __m.unlock();
4788    return __r;
4789}
4790
4791template <class _Tp>
4792inline _LIBCPP_INLINE_VISIBILITY
4793_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4794shared_ptr<_Tp>
4795atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
4796{
4797    return atomic_exchange(__p, __r);
4798}
4799
4800template <class _Tp>
4801_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4802bool
4803atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
4804{
4805    shared_ptr<_Tp> __temp;
4806    __sp_mut& __m = __get_sp_mut(__p);
4807    __m.lock();
4808    if (__p->__owner_equivalent(*__v))
4809    {
4810        _VSTD::swap(__temp, *__p);
4811        *__p = __w;
4812        __m.unlock();
4813        return true;
4814    }
4815    _VSTD::swap(__temp, *__v);
4816    *__v = *__p;
4817    __m.unlock();
4818    return false;
4819}
4820
4821template <class _Tp>
4822inline _LIBCPP_INLINE_VISIBILITY
4823_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4824bool
4825atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
4826{
4827    return atomic_compare_exchange_strong(__p, __v, __w);
4828}
4829
4830template <class _Tp>
4831inline _LIBCPP_INLINE_VISIBILITY
4832_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4833bool
4834atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
4835                                        shared_ptr<_Tp> __w, memory_order, memory_order)
4836{
4837    return atomic_compare_exchange_strong(__p, __v, __w);
4838}
4839
4840template <class _Tp>
4841inline _LIBCPP_INLINE_VISIBILITY
4842_LIBCPP_AVAILABILITY_ATOMIC_SHARED_PTR
4843bool
4844atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
4845                                      shared_ptr<_Tp> __w, memory_order, memory_order)
4846{
4847    return atomic_compare_exchange_weak(__p, __v, __w);
4848}
4849
4850#endif  // !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
4851
4852//enum class
4853#if defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE)
4854# ifndef _LIBCPP_CXX03_LANG
4855enum class pointer_safety : unsigned char {
4856  relaxed,
4857  preferred,
4858  strict
4859};
4860# endif
4861#else
4862struct _LIBCPP_TYPE_VIS pointer_safety
4863{
4864    enum __lx
4865    {
4866        relaxed,
4867        preferred,
4868        strict
4869    };
4870
4871    __lx __v_;
4872
4873    _LIBCPP_INLINE_VISIBILITY
4874    pointer_safety() : __v_() {}
4875
4876    _LIBCPP_INLINE_VISIBILITY
4877    pointer_safety(__lx __v) : __v_(__v) {}
4878    _LIBCPP_INLINE_VISIBILITY
4879    operator int() const {return __v_;}
4880};
4881#endif
4882
4883#if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) && \
4884    defined(_LIBCPP_BUILDING_LIBRARY)
4885_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
4886#else
4887// This function is only offered in C++03 under ABI v1.
4888# if !defined(_LIBCPP_ABI_POINTER_SAFETY_ENUM_TYPE) || !defined(_LIBCPP_CXX03_LANG)
4889inline _LIBCPP_INLINE_VISIBILITY
4890pointer_safety get_pointer_safety() _NOEXCEPT {
4891  return pointer_safety::relaxed;
4892}
4893# endif
4894#endif
4895
4896
4897_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
4898_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
4899_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
4900_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
4901
4902template <class _Tp>
4903inline _LIBCPP_INLINE_VISIBILITY
4904_Tp*
4905undeclare_reachable(_Tp* __p)
4906{
4907    return static_cast<_Tp*>(__undeclare_reachable(__p));
4908}
4909
4910_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
4911
4912// --- Helper for container swap --
4913template <typename _Alloc>
4914inline _LIBCPP_INLINE_VISIBILITY
4915void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
4916#if _LIBCPP_STD_VER >= 14
4917    _NOEXCEPT
4918#else
4919    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
4920#endif
4921{
4922    __swap_allocator(__a1, __a2,
4923      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
4924}
4925
4926template <typename _Alloc>
4927_LIBCPP_INLINE_VISIBILITY
4928void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
4929#if _LIBCPP_STD_VER >= 14
4930    _NOEXCEPT
4931#else
4932    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
4933#endif
4934{
4935    using _VSTD::swap;
4936    swap(__a1, __a2);
4937}
4938
4939template <typename _Alloc>
4940inline _LIBCPP_INLINE_VISIBILITY
4941void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
4942
4943template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
4944struct __noexcept_move_assign_container : public integral_constant<bool,
4945    _Traits::propagate_on_container_move_assignment::value
4946#if _LIBCPP_STD_VER > 14
4947        || _Traits::is_always_equal::value
4948#else
4949        && is_nothrow_move_assignable<_Alloc>::value
4950#endif
4951    > {};
4952
4953
4954template <class _Tp, class _Alloc>
4955struct __temp_value {
4956    typedef allocator_traits<_Alloc> _Traits;
4957
4958    typename aligned_storage<sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp)>::type __v;
4959    _Alloc &__a;
4960
4961    _Tp *__addr() { return reinterpret_cast<_Tp *>(addressof(__v)); }
4962    _Tp &   get() { return *__addr(); }
4963
4964    template<class... _Args>
4965    _LIBCPP_NO_CFI
4966    __temp_value(_Alloc &__alloc, _Args&& ... __args) : __a(__alloc) {
4967      _Traits::construct(__a, reinterpret_cast<_Tp*>(addressof(__v)),
4968                         _VSTD::forward<_Args>(__args)...);
4969    }
4970
4971    ~__temp_value() { _Traits::destroy(__a, __addr()); }
4972    };
4973
4974template<typename _Alloc, typename = void, typename = void>
4975struct __is_allocator : false_type {};
4976
4977template<typename _Alloc>
4978struct __is_allocator<_Alloc,
4979       typename __void_t<typename _Alloc::value_type>::type,
4980       typename __void_t<decltype(_VSTD::declval<_Alloc&>().allocate(size_t(0)))>::type
4981     >
4982   : true_type {};
4983
4984// __builtin_new_allocator -- A non-templated helper for allocating and
4985// deallocating memory using __builtin_operator_new and
4986// __builtin_operator_delete. It should be used in preference to
4987// `std::allocator<T>` to avoid additional instantiations.
4988struct __builtin_new_allocator {
4989  struct __builtin_new_deleter {
4990    typedef void* pointer_type;
4991
4992    _LIBCPP_CONSTEXPR explicit __builtin_new_deleter(size_t __size, size_t __align)
4993        : __size_(__size), __align_(__align) {}
4994
4995    void operator()(void* p) const _NOEXCEPT {
4996        std::__libcpp_deallocate(p, __size_, __align_);
4997    }
4998
4999   private:
5000    size_t __size_;
5001    size_t __align_;
5002  };
5003
5004  typedef unique_ptr<void, __builtin_new_deleter> __holder_t;
5005
5006  static __holder_t __allocate_bytes(size_t __s, size_t __align) {
5007      return __holder_t(std::__libcpp_allocate(__s, __align),
5008                     __builtin_new_deleter(__s, __align));
5009  }
5010
5011  static void __deallocate_bytes(void* __p, size_t __s,
5012                                 size_t __align) _NOEXCEPT {
5013      std::__libcpp_deallocate(__p, __s, __align);
5014  }
5015
5016  template <class _Tp>
5017  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5018  static __holder_t __allocate_type(size_t __n) {
5019      return __allocate_bytes(__n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5020  }
5021
5022  template <class _Tp>
5023  _LIBCPP_NODEBUG _LIBCPP_ALWAYS_INLINE
5024  static void __deallocate_type(void* __p, size_t __n) _NOEXCEPT {
5025      __deallocate_bytes(__p, __n * sizeof(_Tp), _LIBCPP_ALIGNOF(_Tp));
5026  }
5027};
5028
5029
5030_LIBCPP_END_NAMESPACE_STD
5031
5032_LIBCPP_POP_MACROS
5033
5034#if defined(_LIBCPP_HAS_PARALLEL_ALGORITHMS) && _LIBCPP_STD_VER >= 17
5035#   include <__pstl_memory>
5036#endif
5037
5038#endif  // _LIBCPP_MEMORY
5039