xref: /llvm-project-15.0.7/libcxx/include/memory (revision 45faf47e)
1// -*- C++ -*-
2//===-------------------------- memory ------------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_MEMORY
12#define _LIBCPP_MEMORY
13
14/*
15    memory synopsis
16
17namespace std
18{
19
20struct allocator_arg_t { };
21constexpr allocator_arg_t allocator_arg = allocator_arg_t();
22
23template <class T, class Alloc> struct uses_allocator;
24
25template <class Ptr>
26struct pointer_traits
27{
28    typedef Ptr pointer;
29    typedef <details> element_type;
30    typedef <details> difference_type;
31
32    template <class U> using rebind = <details>;
33
34    static pointer pointer_to(<details>);
35};
36
37template <class T>
38struct pointer_traits<T*>
39{
40    typedef T* pointer;
41    typedef T element_type;
42    typedef ptrdiff_t difference_type;
43
44    template <class U> using rebind = U*;
45
46    static pointer pointer_to(<details>) noexcept;
47};
48
49template <class Alloc>
50struct allocator_traits
51{
52    typedef Alloc                        allocator_type;
53    typedef typename allocator_type::value_type
54                                         value_type;
55
56    typedef Alloc::pointer | value_type* pointer;
57    typedef Alloc::const_pointer
58          | pointer_traits<pointer>::rebind<const value_type>
59                                         const_pointer;
60    typedef Alloc::void_pointer
61          | pointer_traits<pointer>::rebind<void>
62                                         void_pointer;
63    typedef Alloc::const_void_pointer
64          | pointer_traits<pointer>::rebind<const void>
65                                         const_void_pointer;
66    typedef Alloc::difference_type
67          | pointer_traits<pointer>::difference_type
68                                         difference_type;
69    typedef Alloc::size_type
70          | make_unsigned<difference_type>::type
71                                         size_type;
72    typedef Alloc::propagate_on_container_copy_assignment
73          | false_type                   propagate_on_container_copy_assignment;
74    typedef Alloc::propagate_on_container_move_assignment
75          | false_type                   propagate_on_container_move_assignment;
76    typedef Alloc::propagate_on_container_swap
77          | false_type                   propagate_on_container_swap;
78    typedef Alloc::is_always_equal
79          | is_empty                     is_always_equal;
80
81    template <class T> using rebind_alloc  = Alloc::rebind<U>::other | Alloc<T, Args...>;
82    template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
83
84    static pointer allocate(allocator_type& a, size_type n);
85    static pointer allocate(allocator_type& a, size_type n, const_void_pointer hint);
86
87    static void deallocate(allocator_type& a, pointer p, size_type n) noexcept;
88
89    template <class T, class... Args>
90        static void construct(allocator_type& a, T* p, Args&&... args);
91
92    template <class T>
93        static void destroy(allocator_type& a, T* p);
94
95    static size_type max_size(const allocator_type& a); // noexcept in C++14
96
97    static allocator_type
98        select_on_container_copy_construction(const allocator_type& a);
99};
100
101template <>
102class allocator<void>
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;
119    typedef const T*                              const_pointer;
120    typedef typename add_lvalue_reference<T>::type       reference;
121    typedef typename add_lvalue_reference<const T>::type const_reference;
122    typedef T                                     value_type;
123
124    template <class U> struct rebind {typedef allocator<U> other;};
125
126    allocator() noexcept;
127    allocator(const allocator&) noexcept;
128    template <class U> allocator(const allocator<U>&) noexcept;
129    ~allocator();
130    pointer address(reference x) const noexcept;
131    const_pointer address(const_reference x) const noexcept;
132    pointer allocate(size_type, allocator<void>::const_pointer hint = 0);
133    void deallocate(pointer p, size_type n) noexcept;
134    size_type max_size() const noexcept;
135    template<class U, class... Args>
136        void construct(U* p, Args&&... args);
137    template <class U>
138        void destroy(U* p);
139};
140
141template <class T, class U>
142bool operator==(const allocator<T>&, const allocator<U>&) noexcept;
143
144template <class T, class U>
145bool operator!=(const allocator<T>&, const allocator<U>&) noexcept;
146
147template <class OutputIterator, class T>
148class raw_storage_iterator
149    : public iterator<output_iterator_tag,
150                      T,                               // purposefully not C++03
151                      ptrdiff_t,                       // purposefully not C++03
152                      T*,                              // purposefully not C++03
153                      raw_storage_iterator&>           // purposefully not C++03
154{
155public:
156    explicit raw_storage_iterator(OutputIterator x);
157    raw_storage_iterator& operator*();
158    raw_storage_iterator& operator=(const T& element);
159    raw_storage_iterator& operator++();
160    raw_storage_iterator  operator++(int);
161};
162
163template <class T> pair<T*,ptrdiff_t> get_temporary_buffer(ptrdiff_t n) noexcept;
164template <class T> void               return_temporary_buffer(T* p) noexcept;
165
166template <class T> T* addressof(T& r) noexcept;
167
168template <class InputIterator, class ForwardIterator>
169ForwardIterator
170uninitialized_copy(InputIterator first, InputIterator last, ForwardIterator result);
171
172template <class InputIterator, class Size, class ForwardIterator>
173ForwardIterator
174uninitialized_copy_n(InputIterator first, Size n, ForwardIterator result);
175
176template <class ForwardIterator, class T>
177void uninitialized_fill(ForwardIterator first, ForwardIterator last, const T& x);
178
179template <class ForwardIterator, class Size, class T>
180ForwardIterator
181uninitialized_fill_n(ForwardIterator first, Size n, const T& x);
182
183template <class Y> struct auto_ptr_ref {};
184
185template<class X>
186class auto_ptr
187{
188public:
189    typedef X element_type;
190
191    explicit auto_ptr(X* p =0) throw();
192    auto_ptr(auto_ptr&) throw();
193    template<class Y> auto_ptr(auto_ptr<Y>&) throw();
194    auto_ptr& operator=(auto_ptr&) throw();
195    template<class Y> auto_ptr& operator=(auto_ptr<Y>&) throw();
196    auto_ptr& operator=(auto_ptr_ref<X> r) throw();
197    ~auto_ptr() throw();
198
199    typename add_lvalue_reference<X>::type operator*() const throw();
200    X* operator->() const throw();
201    X* get() const throw();
202    X* release() throw();
203    void reset(X* p =0) throw();
204
205    auto_ptr(auto_ptr_ref<X>) throw();
206    template<class Y> operator auto_ptr_ref<Y>() throw();
207    template<class Y> operator auto_ptr<Y>() throw();
208};
209
210template <class T>
211struct default_delete
212{
213    constexpr default_delete() noexcept = default;
214    template <class U> default_delete(const default_delete<U>&) noexcept;
215
216    void operator()(T*) const noexcept;
217};
218
219template <class T>
220struct default_delete<T[]>
221{
222    constexpr default_delete() noexcept = default;
223    void operator()(T*) const noexcept;
224    template <class U> void operator()(U*) const = delete;
225};
226
227template <class T, class D = default_delete<T>>
228class unique_ptr
229{
230public:
231    typedef see below pointer;
232    typedef T element_type;
233    typedef D deleter_type;
234
235    // constructors
236    constexpr unique_ptr() noexcept;
237    explicit unique_ptr(pointer p) noexcept;
238    unique_ptr(pointer p, see below d1) noexcept;
239    unique_ptr(pointer p, see below d2) noexcept;
240    unique_ptr(unique_ptr&& u) noexcept;
241    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
242    template <class U, class E>
243        unique_ptr(unique_ptr<U, E>&& u) noexcept;
244    template <class U>
245        unique_ptr(auto_ptr<U>&& u) noexcept;
246
247    // destructor
248    ~unique_ptr();
249
250    // assignment
251    unique_ptr& operator=(unique_ptr&& u) noexcept;
252    template <class U, class E> unique_ptr& operator=(unique_ptr<U, E>&& u) noexcept;
253    unique_ptr& operator=(nullptr_t) noexcept;
254
255    // observers
256    typename add_lvalue_reference<T>::type operator*() const;
257    pointer operator->() const noexcept;
258    pointer get() const noexcept;
259    deleter_type& get_deleter() noexcept;
260    const deleter_type& get_deleter() const noexcept;
261    explicit operator bool() const noexcept;
262
263    // modifiers
264    pointer release() noexcept;
265    void reset(pointer p = pointer()) noexcept;
266    void swap(unique_ptr& u) noexcept;
267};
268
269template <class T, class D>
270class unique_ptr<T[], D>
271{
272public:
273    typedef implementation-defined pointer;
274    typedef T element_type;
275    typedef D deleter_type;
276
277    // constructors
278    constexpr unique_ptr() noexcept;
279    explicit unique_ptr(pointer p) noexcept;
280    unique_ptr(pointer p, see below d) noexcept;
281    unique_ptr(pointer p, see below d) noexcept;
282    unique_ptr(unique_ptr&& u) noexcept;
283    unique_ptr(nullptr_t) noexcept : unique_ptr() { }
284
285    // destructor
286    ~unique_ptr();
287
288    // assignment
289    unique_ptr& operator=(unique_ptr&& u) noexcept;
290    unique_ptr& operator=(nullptr_t) noexcept;
291
292    // observers
293    T& operator[](size_t i) const;
294    pointer get() const noexcept;
295    deleter_type& get_deleter() noexcept;
296    const deleter_type& get_deleter() const noexcept;
297    explicit operator bool() const noexcept;
298
299    // modifiers
300    pointer release() noexcept;
301    void reset(pointer p = pointer()) noexcept;
302    void reset(nullptr_t) noexcept;
303    template <class U> void reset(U) = delete;
304    void swap(unique_ptr& u) noexcept;
305};
306
307template <class T, class D>
308    void swap(unique_ptr<T, D>& x, unique_ptr<T, D>& y) noexcept;
309
310template <class T1, class D1, class T2, class D2>
311    bool operator==(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
312template <class T1, class D1, class T2, class D2>
313    bool operator!=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
314template <class T1, class D1, class T2, class D2>
315    bool operator<(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
316template <class T1, class D1, class T2, class D2>
317    bool operator<=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
318template <class T1, class D1, class T2, class D2>
319    bool operator>(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
320template <class T1, class D1, class T2, class D2>
321    bool operator>=(const unique_ptr<T1, D1>& x, const unique_ptr<T2, D2>& y);
322
323template <class T, class D>
324    bool operator==(const unique_ptr<T, D>& x, nullptr_t) noexcept;
325template <class T, class D>
326    bool operator==(nullptr_t, const unique_ptr<T, D>& y) noexcept;
327template <class T, class D>
328    bool operator!=(const unique_ptr<T, D>& x, nullptr_t) noexcept;
329template <class T, class D>
330    bool operator!=(nullptr_t, const unique_ptr<T, D>& y) noexcept;
331
332template <class T, class D>
333    bool operator<(const unique_ptr<T, D>& x, nullptr_t);
334template <class T, class D>
335    bool operator<(nullptr_t, const unique_ptr<T, D>& y);
336template <class T, class D>
337    bool operator<=(const unique_ptr<T, D>& x, nullptr_t);
338template <class T, class D>
339    bool operator<=(nullptr_t, const unique_ptr<T, D>& y);
340template <class T, class D>
341    bool operator>(const unique_ptr<T, D>& x, nullptr_t);
342template <class T, class D>
343    bool operator>(nullptr_t, const unique_ptr<T, D>& y);
344template <class T, class D>
345    bool operator>=(const unique_ptr<T, D>& x, nullptr_t);
346template <class T, class D>
347    bool operator>=(nullptr_t, const unique_ptr<T, D>& y);
348
349class bad_weak_ptr
350    : public std::exception
351{
352    bad_weak_ptr() noexcept;
353};
354
355template<class T, class... Args> unique_ptr<T> make_unique(Args&&... args);     // C++14
356template<class T>                unique_ptr<T> make_unique(size_t n);           // C++14
357template<class T, class... Args> unspecified   make_unique(Args&&...) = delete; // C++14, T == U[N]
358
359template<class T>
360class shared_ptr
361{
362public:
363    typedef T element_type;
364
365    // constructors:
366    constexpr shared_ptr() noexcept;
367    template<class Y> explicit shared_ptr(Y* p);
368    template<class Y, class D> shared_ptr(Y* p, D d);
369    template<class Y, class D, class A> shared_ptr(Y* p, D d, A a);
370    template <class D> shared_ptr(nullptr_t p, D d);
371    template <class D, class A> shared_ptr(nullptr_t p, D d, A a);
372    template<class Y> shared_ptr(const shared_ptr<Y>& r, T *p) noexcept;
373    shared_ptr(const shared_ptr& r) noexcept;
374    template<class Y> shared_ptr(const shared_ptr<Y>& r) noexcept;
375    shared_ptr(shared_ptr&& r) noexcept;
376    template<class Y> shared_ptr(shared_ptr<Y>&& r) noexcept;
377    template<class Y> explicit shared_ptr(const weak_ptr<Y>& r);
378    template<class Y> shared_ptr(auto_ptr<Y>&& r);
379    template <class Y, class D> shared_ptr(unique_ptr<Y, D>&& r);
380    shared_ptr(nullptr_t) : shared_ptr() { }
381
382    // destructor:
383    ~shared_ptr();
384
385    // assignment:
386    shared_ptr& operator=(const shared_ptr& r) noexcept;
387    template<class Y> shared_ptr& operator=(const shared_ptr<Y>& r) noexcept;
388    shared_ptr& operator=(shared_ptr&& r) noexcept;
389    template<class Y> shared_ptr& operator=(shared_ptr<Y>&& r);
390    template<class Y> shared_ptr& operator=(auto_ptr<Y>&& r);
391    template <class Y, class D> shared_ptr& operator=(unique_ptr<Y, D>&& r);
392
393    // modifiers:
394    void swap(shared_ptr& r) noexcept;
395    void reset() noexcept;
396    template<class Y> void reset(Y* p);
397    template<class Y, class D> void reset(Y* p, D d);
398    template<class Y, class D, class A> void reset(Y* p, D d, A a);
399
400    // observers:
401    T* get() const noexcept;
402    T& operator*() const noexcept;
403    T* operator->() const noexcept;
404    long use_count() const noexcept;
405    bool unique() const noexcept;
406    explicit operator bool() const noexcept;
407    template<class U> bool owner_before(shared_ptr<U> const& b) const;
408    template<class U> bool owner_before(weak_ptr<U> const& b) const;
409};
410
411// shared_ptr comparisons:
412template<class T, class U>
413    bool operator==(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
414template<class T, class U>
415    bool operator!=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
416template<class T, class U>
417    bool operator<(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
418template<class T, class U>
419    bool operator>(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
420template<class T, class U>
421    bool operator<=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
422template<class T, class U>
423    bool operator>=(shared_ptr<T> const& a, shared_ptr<U> const& b) noexcept;
424
425template <class T>
426    bool operator==(const shared_ptr<T>& x, nullptr_t) noexcept;
427template <class T>
428    bool operator==(nullptr_t, const shared_ptr<T>& y) noexcept;
429template <class T>
430    bool operator!=(const shared_ptr<T>& x, nullptr_t) noexcept;
431template <class T>
432    bool operator!=(nullptr_t, const shared_ptr<T>& y) noexcept;
433template <class T>
434    bool operator<(const shared_ptr<T>& x, nullptr_t) noexcept;
435template <class T>
436bool operator<(nullptr_t, const shared_ptr<T>& y) noexcept;
437template <class T>
438    bool operator<=(const shared_ptr<T>& x, nullptr_t) noexcept;
439template <class T>
440    bool operator<=(nullptr_t, const shared_ptr<T>& y) noexcept;
441template <class T>
442    bool operator>(const shared_ptr<T>& x, nullptr_t) noexcept;
443template <class T>
444    bool operator>(nullptr_t, const shared_ptr<T>& y) noexcept;
445template <class T>
446    bool operator>=(const shared_ptr<T>& x, nullptr_t) noexcept;
447template <class T>
448    bool operator>=(nullptr_t, const shared_ptr<T>& y) noexcept;
449
450// shared_ptr specialized algorithms:
451template<class T> void swap(shared_ptr<T>& a, shared_ptr<T>& b) noexcept;
452
453// shared_ptr casts:
454template<class T, class U>
455    shared_ptr<T> static_pointer_cast(shared_ptr<U> const& r) noexcept;
456template<class T, class U>
457    shared_ptr<T> dynamic_pointer_cast(shared_ptr<U> const& r) noexcept;
458template<class T, class U>
459    shared_ptr<T> const_pointer_cast(shared_ptr<U> const& r) noexcept;
460
461// shared_ptr I/O:
462template<class E, class T, class Y>
463    basic_ostream<E, T>& operator<< (basic_ostream<E, T>& os, shared_ptr<Y> const& p);
464
465// shared_ptr get_deleter:
466template<class D, class T> D* get_deleter(shared_ptr<T> const& p) noexcept;
467
468template<class T, class... Args>
469    shared_ptr<T> make_shared(Args&&... args);
470template<class T, class A, class... Args>
471    shared_ptr<T> allocate_shared(const A& a, Args&&... args);
472
473template<class T>
474class weak_ptr
475{
476public:
477    typedef T element_type;
478
479    // constructors
480    constexpr weak_ptr() noexcept;
481    template<class Y> weak_ptr(shared_ptr<Y> const& r) noexcept;
482    weak_ptr(weak_ptr const& r) noexcept;
483    template<class Y> weak_ptr(weak_ptr<Y> const& r) noexcept;
484    weak_ptr(weak_ptr&& r) noexcept;                      // C++14
485    template<class Y> weak_ptr(weak_ptr<Y>&& r) noexcept; // C++14
486
487    // destructor
488    ~weak_ptr();
489
490    // assignment
491    weak_ptr& operator=(weak_ptr const& r) noexcept;
492    template<class Y> weak_ptr& operator=(weak_ptr<Y> const& r) noexcept;
493    template<class Y> weak_ptr& operator=(shared_ptr<Y> const& r) noexcept;
494    weak_ptr& operator=(weak_ptr&& r) noexcept;                      // C++14
495    template<class Y> weak_ptr& operator=(weak_ptr<Y>&& r) noexcept; // C++14
496
497    // modifiers
498    void swap(weak_ptr& r) noexcept;
499    void reset() noexcept;
500
501    // observers
502    long use_count() const noexcept;
503    bool expired() const noexcept;
504    shared_ptr<T> lock() const noexcept;
505    template<class U> bool owner_before(shared_ptr<U> const& b) const;
506    template<class U> bool owner_before(weak_ptr<U> const& b) const;
507};
508
509// weak_ptr specialized algorithms:
510template<class T> void swap(weak_ptr<T>& a, weak_ptr<T>& b) noexcept;
511
512// class owner_less:
513template<class T> struct owner_less;
514
515template<class T>
516struct owner_less<shared_ptr<T>>
517    : binary_function<shared_ptr<T>, shared_ptr<T>, bool>
518{
519    typedef bool result_type;
520    bool operator()(shared_ptr<T> const&, shared_ptr<T> const&) const;
521    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const;
522    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const;
523};
524
525template<class T>
526struct owner_less<weak_ptr<T>>
527    : binary_function<weak_ptr<T>, weak_ptr<T>, bool>
528{
529    typedef bool result_type;
530    bool operator()(weak_ptr<T> const&, weak_ptr<T> const&) const;
531    bool operator()(shared_ptr<T> const&, weak_ptr<T> const&) const;
532    bool operator()(weak_ptr<T> const&, shared_ptr<T> const&) const;
533};
534
535template<class T>
536class enable_shared_from_this
537{
538protected:
539    constexpr enable_shared_from_this() noexcept;
540    enable_shared_from_this(enable_shared_from_this const&) noexcept;
541    enable_shared_from_this& operator=(enable_shared_from_this const&) noexcept;
542    ~enable_shared_from_this();
543public:
544    shared_ptr<T> shared_from_this();
545    shared_ptr<T const> shared_from_this() const;
546};
547
548template<class T>
549    bool atomic_is_lock_free(const shared_ptr<T>* p);
550template<class T>
551    shared_ptr<T> atomic_load(const shared_ptr<T>* p);
552template<class T>
553    shared_ptr<T> atomic_load_explicit(const shared_ptr<T>* p, memory_order mo);
554template<class T>
555    void atomic_store(shared_ptr<T>* p, shared_ptr<T> r);
556template<class T>
557    void atomic_store_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
558template<class T>
559    shared_ptr<T> atomic_exchange(shared_ptr<T>* p, shared_ptr<T> r);
560template<class T>
561    shared_ptr<T>
562    atomic_exchange_explicit(shared_ptr<T>* p, shared_ptr<T> r, memory_order mo);
563template<class T>
564    bool
565    atomic_compare_exchange_weak(shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
566template<class T>
567    bool
568    atomic_compare_exchange_strong( shared_ptr<T>* p, shared_ptr<T>* v, shared_ptr<T> w);
569template<class T>
570    bool
571    atomic_compare_exchange_weak_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
572                                          shared_ptr<T> w, memory_order success,
573                                          memory_order failure);
574template<class T>
575    bool
576    atomic_compare_exchange_strong_explicit(shared_ptr<T>* p, shared_ptr<T>* v,
577                                            shared_ptr<T> w, memory_order success,
578                                            memory_order failure);
579// Hash support
580template <class T> struct hash;
581template <class T, class D> struct hash<unique_ptr<T, D> >;
582template <class T> struct hash<shared_ptr<T> >;
583
584// Pointer safety
585enum class pointer_safety { relaxed, preferred, strict };
586void declare_reachable(void *p);
587template <class T> T *undeclare_reachable(T *p);
588void declare_no_pointers(char *p, size_t n);
589void undeclare_no_pointers(char *p, size_t n);
590pointer_safety get_pointer_safety() noexcept;
591
592void* align(size_t alignment, size_t size, void*& ptr, size_t& space);
593
594}  // std
595
596*/
597
598#include <__config>
599#include <type_traits>
600#include <typeinfo>
601#include <cstddef>
602#include <cstdint>
603#include <new>
604#include <utility>
605#include <limits>
606#include <iterator>
607#include <__functional_base>
608#include <iosfwd>
609#include <tuple>
610#include <cstring>
611#if defined(_LIBCPP_NO_EXCEPTIONS)
612    #include <cassert>
613#endif
614
615#if !defined(_LIBCPP_HAS_NO_ATOMIC_HEADER)
616#  include <atomic>
617#endif
618
619#include <__undef_min_max>
620#include <__undef___deallocate>
621
622#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
623#pragma GCC system_header
624#endif
625
626_LIBCPP_BEGIN_NAMESPACE_STD
627
628template <class _ValueType>
629inline _LIBCPP_ALWAYS_INLINE
630_ValueType __libcpp_relaxed_load(_ValueType const* __value) {
631#if !defined(_LIBCPP_HAS_NO_THREADS) && \
632    defined(__ATOMIC_RELAXED) &&        \
633    (__has_builtin(__atomic_load_n) || _GNUC_VER >= 407)
634    return __atomic_load_n(__value, __ATOMIC_RELAXED);
635#else
636    return *__value;
637#endif
638}
639
640// addressof moved to <__functional_base>
641
642template <class _Tp> class allocator;
643
644template <>
645class _LIBCPP_TYPE_VIS_ONLY allocator<void>
646{
647public:
648    typedef void*             pointer;
649    typedef const void*       const_pointer;
650    typedef void              value_type;
651
652    template <class _Up> struct rebind {typedef allocator<_Up> other;};
653};
654
655template <>
656class _LIBCPP_TYPE_VIS_ONLY allocator<const void>
657{
658public:
659    typedef const void*       pointer;
660    typedef const void*       const_pointer;
661    typedef const void        value_type;
662
663    template <class _Up> struct rebind {typedef allocator<_Up> other;};
664};
665
666// pointer_traits
667
668template <class _Tp>
669struct __has_element_type
670{
671private:
672    struct __two {char __lx; char __lxx;};
673    template <class _Up> static __two __test(...);
674    template <class _Up> static char __test(typename _Up::element_type* = 0);
675public:
676    static const bool value = sizeof(__test<_Tp>(0)) == 1;
677};
678
679template <class _Ptr, bool = __has_element_type<_Ptr>::value>
680struct __pointer_traits_element_type;
681
682template <class _Ptr>
683struct __pointer_traits_element_type<_Ptr, true>
684{
685    typedef typename _Ptr::element_type type;
686};
687
688#ifndef _LIBCPP_HAS_NO_VARIADICS
689
690template <template <class, class...> class _Sp, class _Tp, class ..._Args>
691struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, true>
692{
693    typedef typename _Sp<_Tp, _Args...>::element_type type;
694};
695
696template <template <class, class...> class _Sp, class _Tp, class ..._Args>
697struct __pointer_traits_element_type<_Sp<_Tp, _Args...>, false>
698{
699    typedef _Tp type;
700};
701
702#else  // _LIBCPP_HAS_NO_VARIADICS
703
704template <template <class> class _Sp, class _Tp>
705struct __pointer_traits_element_type<_Sp<_Tp>, true>
706{
707    typedef typename _Sp<_Tp>::element_type type;
708};
709
710template <template <class> class _Sp, class _Tp>
711struct __pointer_traits_element_type<_Sp<_Tp>, false>
712{
713    typedef _Tp type;
714};
715
716template <template <class, class> class _Sp, class _Tp, class _A0>
717struct __pointer_traits_element_type<_Sp<_Tp, _A0>, true>
718{
719    typedef typename _Sp<_Tp, _A0>::element_type type;
720};
721
722template <template <class, class> class _Sp, class _Tp, class _A0>
723struct __pointer_traits_element_type<_Sp<_Tp, _A0>, false>
724{
725    typedef _Tp type;
726};
727
728template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
729struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, true>
730{
731    typedef typename _Sp<_Tp, _A0, _A1>::element_type type;
732};
733
734template <template <class, class, class> class _Sp, class _Tp, class _A0, class _A1>
735struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1>, false>
736{
737    typedef _Tp type;
738};
739
740template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
741                                                           class _A1, class _A2>
742struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, true>
743{
744    typedef typename _Sp<_Tp, _A0, _A1, _A2>::element_type type;
745};
746
747template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
748                                                           class _A1, class _A2>
749struct __pointer_traits_element_type<_Sp<_Tp, _A0, _A1, _A2>, false>
750{
751    typedef _Tp type;
752};
753
754#endif  // _LIBCPP_HAS_NO_VARIADICS
755
756template <class _Tp>
757struct __has_difference_type
758{
759private:
760    struct __two {char __lx; char __lxx;};
761    template <class _Up> static __two __test(...);
762    template <class _Up> static char __test(typename _Up::difference_type* = 0);
763public:
764    static const bool value = sizeof(__test<_Tp>(0)) == 1;
765};
766
767template <class _Ptr, bool = __has_difference_type<_Ptr>::value>
768struct __pointer_traits_difference_type
769{
770    typedef ptrdiff_t type;
771};
772
773template <class _Ptr>
774struct __pointer_traits_difference_type<_Ptr, true>
775{
776    typedef typename _Ptr::difference_type type;
777};
778
779template <class _Tp, class _Up>
780struct __has_rebind
781{
782private:
783    struct __two {char __lx; char __lxx;};
784    template <class _Xp> static __two __test(...);
785    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>* = 0);
786public:
787    static const bool value = sizeof(__test<_Tp>(0)) == 1;
788};
789
790template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
791struct __pointer_traits_rebind
792{
793#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
794    typedef typename _Tp::template rebind<_Up> type;
795#else
796    typedef typename _Tp::template rebind<_Up>::other type;
797#endif
798};
799
800#ifndef _LIBCPP_HAS_NO_VARIADICS
801
802template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
803struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, true>
804{
805#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
806    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up> type;
807#else
808    typedef typename _Sp<_Tp, _Args...>::template rebind<_Up>::other type;
809#endif
810};
811
812template <template <class, class...> class _Sp, class _Tp, class ..._Args, class _Up>
813struct __pointer_traits_rebind<_Sp<_Tp, _Args...>, _Up, false>
814{
815    typedef _Sp<_Up, _Args...> type;
816};
817
818#else  // _LIBCPP_HAS_NO_VARIADICS
819
820template <template <class> class _Sp, class _Tp, class _Up>
821struct __pointer_traits_rebind<_Sp<_Tp>, _Up, true>
822{
823#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
824    typedef typename _Sp<_Tp>::template rebind<_Up> type;
825#else
826    typedef typename _Sp<_Tp>::template rebind<_Up>::other type;
827#endif
828};
829
830template <template <class> class _Sp, class _Tp, class _Up>
831struct __pointer_traits_rebind<_Sp<_Tp>, _Up, false>
832{
833    typedef _Sp<_Up> type;
834};
835
836template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
837struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, true>
838{
839#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
840    typedef typename _Sp<_Tp, _A0>::template rebind<_Up> type;
841#else
842    typedef typename _Sp<_Tp, _A0>::template rebind<_Up>::other type;
843#endif
844};
845
846template <template <class, class> class _Sp, class _Tp, class _A0, class _Up>
847struct __pointer_traits_rebind<_Sp<_Tp, _A0>, _Up, false>
848{
849    typedef _Sp<_Up, _A0> type;
850};
851
852template <template <class, class, class> class _Sp, class _Tp, class _A0,
853                                         class _A1, class _Up>
854struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, true>
855{
856#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
857    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up> type;
858#else
859    typedef typename _Sp<_Tp, _A0, _A1>::template rebind<_Up>::other type;
860#endif
861};
862
863template <template <class, class, class> class _Sp, class _Tp, class _A0,
864                                         class _A1, class _Up>
865struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1>, _Up, false>
866{
867    typedef _Sp<_Up, _A0, _A1> type;
868};
869
870template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
871                                                class _A1, class _A2, class _Up>
872struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, true>
873{
874#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
875    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up> type;
876#else
877    typedef typename _Sp<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
878#endif
879};
880
881template <template <class, class, class, class> class _Sp, class _Tp, class _A0,
882                                                class _A1, class _A2, class _Up>
883struct __pointer_traits_rebind<_Sp<_Tp, _A0, _A1, _A2>, _Up, false>
884{
885    typedef _Sp<_Up, _A0, _A1, _A2> type;
886};
887
888#endif  // _LIBCPP_HAS_NO_VARIADICS
889
890template <class _Ptr>
891struct _LIBCPP_TYPE_VIS_ONLY pointer_traits
892{
893    typedef _Ptr                                                     pointer;
894    typedef typename __pointer_traits_element_type<pointer>::type    element_type;
895    typedef typename __pointer_traits_difference_type<pointer>::type difference_type;
896
897#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
898    template <class _Up> using rebind = typename __pointer_traits_rebind<pointer, _Up>::type;
899#else
900    template <class _Up> struct rebind
901        {typedef typename __pointer_traits_rebind<pointer, _Up>::type other;};
902#endif  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
903
904private:
905    struct __nat {};
906public:
907    _LIBCPP_INLINE_VISIBILITY
908    static pointer pointer_to(typename conditional<is_void<element_type>::value,
909                                           __nat, element_type>::type& __r)
910        {return pointer::pointer_to(__r);}
911};
912
913template <class _Tp>
914struct _LIBCPP_TYPE_VIS_ONLY pointer_traits<_Tp*>
915{
916    typedef _Tp*      pointer;
917    typedef _Tp       element_type;
918    typedef ptrdiff_t difference_type;
919
920#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
921    template <class _Up> using rebind = _Up*;
922#else
923    template <class _Up> struct rebind {typedef _Up* other;};
924#endif
925
926private:
927    struct __nat {};
928public:
929    _LIBCPP_INLINE_VISIBILITY
930    static pointer pointer_to(typename conditional<is_void<element_type>::value,
931                                      __nat, element_type>::type& __r) _NOEXCEPT
932        {return _VSTD::addressof(__r);}
933};
934
935template <class _From, class _To>
936struct __rebind_pointer {
937#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
938    typedef typename pointer_traits<_From>::template rebind<_To>        type;
939#else
940    typedef typename pointer_traits<_From>::template rebind<_To>::other type;
941#endif
942};
943
944// allocator_traits
945
946namespace __has_pointer_type_imp
947{
948    template <class _Up> static __two __test(...);
949    template <class _Up> static char __test(typename _Up::pointer* = 0);
950}
951
952template <class _Tp>
953struct __has_pointer_type
954    : public integral_constant<bool, sizeof(__has_pointer_type_imp::__test<_Tp>(0)) == 1>
955{
956};
957
958namespace __pointer_type_imp
959{
960
961template <class _Tp, class _Dp, bool = __has_pointer_type<_Dp>::value>
962struct __pointer_type
963{
964    typedef typename _Dp::pointer type;
965};
966
967template <class _Tp, class _Dp>
968struct __pointer_type<_Tp, _Dp, false>
969{
970    typedef _Tp* type;
971};
972
973}  // __pointer_type_imp
974
975template <class _Tp, class _Dp>
976struct __pointer_type
977{
978    typedef typename __pointer_type_imp::__pointer_type<_Tp, typename remove_reference<_Dp>::type>::type type;
979};
980
981template <class _Tp>
982struct __has_const_pointer
983{
984private:
985    struct __two {char __lx; char __lxx;};
986    template <class _Up> static __two __test(...);
987    template <class _Up> static char __test(typename _Up::const_pointer* = 0);
988public:
989    static const bool value = sizeof(__test<_Tp>(0)) == 1;
990};
991
992template <class _Tp, class _Ptr, class _Alloc, bool = __has_const_pointer<_Alloc>::value>
993struct __const_pointer
994{
995    typedef typename _Alloc::const_pointer type;
996};
997
998template <class _Tp, class _Ptr, class _Alloc>
999struct __const_pointer<_Tp, _Ptr, _Alloc, false>
1000{
1001#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
1002    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp> type;
1003#else
1004    typedef typename pointer_traits<_Ptr>::template rebind<const _Tp>::other type;
1005#endif
1006};
1007
1008template <class _Tp>
1009struct __has_void_pointer
1010{
1011private:
1012    struct __two {char __lx; char __lxx;};
1013    template <class _Up> static __two __test(...);
1014    template <class _Up> static char __test(typename _Up::void_pointer* = 0);
1015public:
1016    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1017};
1018
1019template <class _Ptr, class _Alloc, bool = __has_void_pointer<_Alloc>::value>
1020struct __void_pointer
1021{
1022    typedef typename _Alloc::void_pointer type;
1023};
1024
1025template <class _Ptr, class _Alloc>
1026struct __void_pointer<_Ptr, _Alloc, false>
1027{
1028#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
1029    typedef typename pointer_traits<_Ptr>::template rebind<void> type;
1030#else
1031    typedef typename pointer_traits<_Ptr>::template rebind<void>::other type;
1032#endif
1033};
1034
1035template <class _Tp>
1036struct __has_const_void_pointer
1037{
1038private:
1039    struct __two {char __lx; char __lxx;};
1040    template <class _Up> static __two __test(...);
1041    template <class _Up> static char __test(typename _Up::const_void_pointer* = 0);
1042public:
1043    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1044};
1045
1046template <class _Ptr, class _Alloc, bool = __has_const_void_pointer<_Alloc>::value>
1047struct __const_void_pointer
1048{
1049    typedef typename _Alloc::const_void_pointer type;
1050};
1051
1052template <class _Ptr, class _Alloc>
1053struct __const_void_pointer<_Ptr, _Alloc, false>
1054{
1055#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
1056    typedef typename pointer_traits<_Ptr>::template rebind<const void> type;
1057#else
1058    typedef typename pointer_traits<_Ptr>::template rebind<const void>::other type;
1059#endif
1060};
1061
1062template <class _Tp>
1063inline _LIBCPP_INLINE_VISIBILITY
1064_Tp*
1065__to_raw_pointer(_Tp* __p) _NOEXCEPT
1066{
1067    return __p;
1068}
1069
1070template <class _Pointer>
1071inline _LIBCPP_INLINE_VISIBILITY
1072typename pointer_traits<_Pointer>::element_type*
1073__to_raw_pointer(_Pointer __p) _NOEXCEPT
1074{
1075    return _VSTD::__to_raw_pointer(__p.operator->());
1076}
1077
1078template <class _Tp>
1079struct __has_size_type
1080{
1081private:
1082    struct __two {char __lx; char __lxx;};
1083    template <class _Up> static __two __test(...);
1084    template <class _Up> static char __test(typename _Up::size_type* = 0);
1085public:
1086    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1087};
1088
1089template <class _Alloc, class _DiffType, bool = __has_size_type<_Alloc>::value>
1090struct __size_type
1091{
1092    typedef typename make_unsigned<_DiffType>::type type;
1093};
1094
1095template <class _Alloc, class _DiffType>
1096struct __size_type<_Alloc, _DiffType, true>
1097{
1098    typedef typename _Alloc::size_type type;
1099};
1100
1101template <class _Tp>
1102struct __has_propagate_on_container_copy_assignment
1103{
1104private:
1105    struct __two {char __lx; char __lxx;};
1106    template <class _Up> static __two __test(...);
1107    template <class _Up> static char __test(typename _Up::propagate_on_container_copy_assignment* = 0);
1108public:
1109    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1110};
1111
1112template <class _Alloc, bool = __has_propagate_on_container_copy_assignment<_Alloc>::value>
1113struct __propagate_on_container_copy_assignment
1114{
1115    typedef false_type type;
1116};
1117
1118template <class _Alloc>
1119struct __propagate_on_container_copy_assignment<_Alloc, true>
1120{
1121    typedef typename _Alloc::propagate_on_container_copy_assignment type;
1122};
1123
1124template <class _Tp>
1125struct __has_propagate_on_container_move_assignment
1126{
1127private:
1128    struct __two {char __lx; char __lxx;};
1129    template <class _Up> static __two __test(...);
1130    template <class _Up> static char __test(typename _Up::propagate_on_container_move_assignment* = 0);
1131public:
1132    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1133};
1134
1135template <class _Alloc, bool = __has_propagate_on_container_move_assignment<_Alloc>::value>
1136struct __propagate_on_container_move_assignment
1137{
1138    typedef false_type type;
1139};
1140
1141template <class _Alloc>
1142struct __propagate_on_container_move_assignment<_Alloc, true>
1143{
1144    typedef typename _Alloc::propagate_on_container_move_assignment type;
1145};
1146
1147template <class _Tp>
1148struct __has_propagate_on_container_swap
1149{
1150private:
1151    struct __two {char __lx; char __lxx;};
1152    template <class _Up> static __two __test(...);
1153    template <class _Up> static char __test(typename _Up::propagate_on_container_swap* = 0);
1154public:
1155    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1156};
1157
1158template <class _Alloc, bool = __has_propagate_on_container_swap<_Alloc>::value>
1159struct __propagate_on_container_swap
1160{
1161    typedef false_type type;
1162};
1163
1164template <class _Alloc>
1165struct __propagate_on_container_swap<_Alloc, true>
1166{
1167    typedef typename _Alloc::propagate_on_container_swap type;
1168};
1169
1170template <class _Tp>
1171struct __has_is_always_equal
1172{
1173private:
1174    struct __two {char __lx; char __lxx;};
1175    template <class _Up> static __two __test(...);
1176    template <class _Up> static char __test(typename _Up::is_always_equal* = 0);
1177public:
1178    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1179};
1180
1181template <class _Alloc, bool = __has_is_always_equal<_Alloc>::value>
1182struct __is_always_equal
1183{
1184    typedef typename _VSTD::is_empty<_Alloc>::type type;
1185};
1186
1187template <class _Alloc>
1188struct __is_always_equal<_Alloc, true>
1189{
1190    typedef typename _Alloc::is_always_equal type;
1191};
1192
1193template <class _Tp, class _Up, bool = __has_rebind<_Tp, _Up>::value>
1194struct __has_rebind_other
1195{
1196private:
1197    struct __two {char __lx; char __lxx;};
1198    template <class _Xp> static __two __test(...);
1199    template <class _Xp> static char __test(typename _Xp::template rebind<_Up>::other* = 0);
1200public:
1201    static const bool value = sizeof(__test<_Tp>(0)) == 1;
1202};
1203
1204template <class _Tp, class _Up>
1205struct __has_rebind_other<_Tp, _Up, false>
1206{
1207    static const bool value = false;
1208};
1209
1210template <class _Tp, class _Up, bool = __has_rebind_other<_Tp, _Up>::value>
1211struct __allocator_traits_rebind
1212{
1213    typedef typename _Tp::template rebind<_Up>::other type;
1214};
1215
1216#ifndef _LIBCPP_HAS_NO_VARIADICS
1217
1218template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1219struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, true>
1220{
1221    typedef typename _Alloc<_Tp, _Args...>::template rebind<_Up>::other type;
1222};
1223
1224template <template <class, class...> class _Alloc, class _Tp, class ..._Args, class _Up>
1225struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
1226{
1227    typedef _Alloc<_Up, _Args...> type;
1228};
1229
1230#else  // _LIBCPP_HAS_NO_VARIADICS
1231
1232template <template <class> class _Alloc, class _Tp, class _Up>
1233struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, true>
1234{
1235    typedef typename _Alloc<_Tp>::template rebind<_Up>::other type;
1236};
1237
1238template <template <class> class _Alloc, class _Tp, class _Up>
1239struct __allocator_traits_rebind<_Alloc<_Tp>, _Up, false>
1240{
1241    typedef _Alloc<_Up> type;
1242};
1243
1244template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1245struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, true>
1246{
1247    typedef typename _Alloc<_Tp, _A0>::template rebind<_Up>::other type;
1248};
1249
1250template <template <class, class> class _Alloc, class _Tp, class _A0, class _Up>
1251struct __allocator_traits_rebind<_Alloc<_Tp, _A0>, _Up, false>
1252{
1253    typedef _Alloc<_Up, _A0> type;
1254};
1255
1256template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1257                                         class _A1, class _Up>
1258struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, true>
1259{
1260    typedef typename _Alloc<_Tp, _A0, _A1>::template rebind<_Up>::other type;
1261};
1262
1263template <template <class, class, class> class _Alloc, class _Tp, class _A0,
1264                                         class _A1, class _Up>
1265struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1>, _Up, false>
1266{
1267    typedef _Alloc<_Up, _A0, _A1> type;
1268};
1269
1270template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1271                                                class _A1, class _A2, class _Up>
1272struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, true>
1273{
1274    typedef typename _Alloc<_Tp, _A0, _A1, _A2>::template rebind<_Up>::other type;
1275};
1276
1277template <template <class, class, class, class> class _Alloc, class _Tp, class _A0,
1278                                                class _A1, class _A2, class _Up>
1279struct __allocator_traits_rebind<_Alloc<_Tp, _A0, _A1, _A2>, _Up, false>
1280{
1281    typedef _Alloc<_Up, _A0, _A1, _A2> type;
1282};
1283
1284#endif  // _LIBCPP_HAS_NO_VARIADICS
1285
1286#ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
1287
1288template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1289auto
1290__has_allocate_hint_test(_Alloc&& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1291    -> decltype(__a.allocate(__sz, __p), true_type());
1292
1293template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1294auto
1295__has_allocate_hint_test(const _Alloc& __a, _SizeType&& __sz, _ConstVoidPtr&& __p)
1296    -> false_type;
1297
1298template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1299struct __has_allocate_hint
1300    : integral_constant<bool,
1301        is_same<
1302            decltype(__has_allocate_hint_test(declval<_Alloc>(),
1303                                          declval<_SizeType>(),
1304                                          declval<_ConstVoidPtr>())),
1305            true_type>::value>
1306{
1307};
1308
1309#else  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
1310
1311template <class _Alloc, class _SizeType, class _ConstVoidPtr>
1312struct __has_allocate_hint
1313    : true_type
1314{
1315};
1316
1317#endif  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
1318
1319#if !defined(_LIBCPP_HAS_NO_ADVANCED_SFINAE) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1320
1321template <class _Alloc, class _Tp, class ..._Args>
1322decltype(_VSTD::declval<_Alloc>().construct(_VSTD::declval<_Tp*>(),
1323                                           _VSTD::declval<_Args>()...),
1324                                           true_type())
1325__has_construct_test(_Alloc&& __a, _Tp* __p, _Args&& ...__args);
1326
1327template <class _Alloc, class _Pointer, class ..._Args>
1328false_type
1329__has_construct_test(const _Alloc& __a, _Pointer&& __p, _Args&& ...__args);
1330
1331template <class _Alloc, class _Pointer, class ..._Args>
1332struct __has_construct
1333    : integral_constant<bool,
1334        is_same<
1335            decltype(__has_construct_test(declval<_Alloc>(),
1336                                          declval<_Pointer>(),
1337                                          declval<_Args>()...)),
1338            true_type>::value>
1339{
1340};
1341
1342template <class _Alloc, class _Pointer>
1343auto
1344__has_destroy_test(_Alloc&& __a, _Pointer&& __p)
1345    -> decltype(__a.destroy(__p), true_type());
1346
1347template <class _Alloc, class _Pointer>
1348auto
1349__has_destroy_test(const _Alloc& __a, _Pointer&& __p)
1350    -> false_type;
1351
1352template <class _Alloc, class _Pointer>
1353struct __has_destroy
1354    : integral_constant<bool,
1355        is_same<
1356            decltype(__has_destroy_test(declval<_Alloc>(),
1357                                        declval<_Pointer>())),
1358            true_type>::value>
1359{
1360};
1361
1362template <class _Alloc>
1363auto
1364__has_max_size_test(_Alloc&& __a)
1365    -> decltype(__a.max_size(), true_type());
1366
1367template <class _Alloc>
1368auto
1369__has_max_size_test(const volatile _Alloc& __a)
1370    -> false_type;
1371
1372template <class _Alloc>
1373struct __has_max_size
1374    : integral_constant<bool,
1375        is_same<
1376            decltype(__has_max_size_test(declval<_Alloc&>())),
1377            true_type>::value>
1378{
1379};
1380
1381template <class _Alloc>
1382auto
1383__has_select_on_container_copy_construction_test(_Alloc&& __a)
1384    -> decltype(__a.select_on_container_copy_construction(), true_type());
1385
1386template <class _Alloc>
1387auto
1388__has_select_on_container_copy_construction_test(const volatile _Alloc& __a)
1389    -> false_type;
1390
1391template <class _Alloc>
1392struct __has_select_on_container_copy_construction
1393    : integral_constant<bool,
1394        is_same<
1395            decltype(__has_select_on_container_copy_construction_test(declval<_Alloc&>())),
1396            true_type>::value>
1397{
1398};
1399
1400#else  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
1401
1402#ifndef _LIBCPP_HAS_NO_VARIADICS
1403
1404template <class _Alloc, class _Pointer, class ..._Args>
1405struct __has_construct
1406    : false_type
1407{
1408};
1409
1410#else  // _LIBCPP_HAS_NO_VARIADICS
1411
1412template <class _Alloc, class _Pointer, class _Args>
1413struct __has_construct
1414    : false_type
1415{
1416};
1417
1418#endif  // _LIBCPP_HAS_NO_VARIADICS
1419
1420template <class _Alloc, class _Pointer>
1421struct __has_destroy
1422    : false_type
1423{
1424};
1425
1426template <class _Alloc>
1427struct __has_max_size
1428    : true_type
1429{
1430};
1431
1432template <class _Alloc>
1433struct __has_select_on_container_copy_construction
1434    : false_type
1435{
1436};
1437
1438#endif  // _LIBCPP_HAS_NO_ADVANCED_SFINAE
1439
1440template <class _Alloc, class _Ptr, bool = __has_difference_type<_Alloc>::value>
1441struct __alloc_traits_difference_type
1442{
1443    typedef typename pointer_traits<_Ptr>::difference_type type;
1444};
1445
1446template <class _Alloc, class _Ptr>
1447struct __alloc_traits_difference_type<_Alloc, _Ptr, true>
1448{
1449    typedef typename _Alloc::difference_type type;
1450};
1451
1452template <class _Alloc>
1453struct _LIBCPP_TYPE_VIS_ONLY allocator_traits
1454{
1455    typedef _Alloc                              allocator_type;
1456    typedef typename allocator_type::value_type value_type;
1457
1458    typedef typename __pointer_type<value_type, allocator_type>::type pointer;
1459    typedef typename __const_pointer<value_type, pointer, allocator_type>::type const_pointer;
1460    typedef typename __void_pointer<pointer, allocator_type>::type void_pointer;
1461    typedef typename __const_void_pointer<pointer, allocator_type>::type const_void_pointer;
1462
1463    typedef typename __alloc_traits_difference_type<allocator_type, pointer>::type difference_type;
1464    typedef typename __size_type<allocator_type, difference_type>::type size_type;
1465
1466    typedef typename __propagate_on_container_copy_assignment<allocator_type>::type
1467                     propagate_on_container_copy_assignment;
1468    typedef typename __propagate_on_container_move_assignment<allocator_type>::type
1469                     propagate_on_container_move_assignment;
1470    typedef typename __propagate_on_container_swap<allocator_type>::type
1471                     propagate_on_container_swap;
1472    typedef typename __is_always_equal<allocator_type>::type
1473                     is_always_equal;
1474
1475#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
1476    template <class _Tp> using rebind_alloc =
1477                  typename __allocator_traits_rebind<allocator_type, _Tp>::type;
1478    template <class _Tp> using rebind_traits = allocator_traits<rebind_alloc<_Tp>>;
1479#else  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
1480    template <class _Tp> struct rebind_alloc
1481        {typedef typename __allocator_traits_rebind<allocator_type, _Tp>::type other;};
1482    template <class _Tp> struct rebind_traits
1483        {typedef allocator_traits<typename rebind_alloc<_Tp>::other> other;};
1484#endif  // _LIBCPP_HAS_NO_TEMPLATE_ALIASES
1485
1486    _LIBCPP_INLINE_VISIBILITY
1487    static pointer allocate(allocator_type& __a, size_type __n)
1488        {return __a.allocate(__n);}
1489    _LIBCPP_INLINE_VISIBILITY
1490    static pointer allocate(allocator_type& __a, size_type __n, const_void_pointer __hint)
1491        {return allocate(__a, __n, __hint,
1492            __has_allocate_hint<allocator_type, size_type, const_void_pointer>());}
1493
1494    _LIBCPP_INLINE_VISIBILITY
1495    static void deallocate(allocator_type& __a, pointer __p, size_type __n) _NOEXCEPT
1496        {__a.deallocate(__p, __n);}
1497
1498#ifndef _LIBCPP_HAS_NO_VARIADICS
1499    template <class _Tp, class... _Args>
1500        _LIBCPP_INLINE_VISIBILITY
1501        static void construct(allocator_type& __a, _Tp* __p, _Args&&... __args)
1502            {__construct(__has_construct<allocator_type, _Tp*, _Args...>(),
1503                         __a, __p, _VSTD::forward<_Args>(__args)...);}
1504#else  // _LIBCPP_HAS_NO_VARIADICS
1505    template <class _Tp>
1506        _LIBCPP_INLINE_VISIBILITY
1507        static void construct(allocator_type& __a, _Tp* __p)
1508            {
1509                ::new ((void*)__p) _Tp();
1510            }
1511    template <class _Tp, class _A0>
1512        _LIBCPP_INLINE_VISIBILITY
1513        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0)
1514            {
1515                ::new ((void*)__p) _Tp(__a0);
1516            }
1517    template <class _Tp, class _A0, class _A1>
1518        _LIBCPP_INLINE_VISIBILITY
1519        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0,
1520                              const _A1& __a1)
1521            {
1522                ::new ((void*)__p) _Tp(__a0, __a1);
1523            }
1524    template <class _Tp, class _A0, class _A1, class _A2>
1525        _LIBCPP_INLINE_VISIBILITY
1526        static void construct(allocator_type& __a, _Tp* __p, const _A0& __a0,
1527                              const _A1& __a1, const _A2& __a2)
1528            {
1529                ::new ((void*)__p) _Tp(__a0, __a1, __a2);
1530            }
1531#endif  // _LIBCPP_HAS_NO_VARIADICS
1532
1533    template <class _Tp>
1534        _LIBCPP_INLINE_VISIBILITY
1535        static void destroy(allocator_type& __a, _Tp* __p)
1536            {__destroy(__has_destroy<allocator_type, _Tp*>(), __a, __p);}
1537
1538    _LIBCPP_INLINE_VISIBILITY
1539    static size_type max_size(const allocator_type& __a) _NOEXCEPT
1540        {return __max_size(__has_max_size<const allocator_type>(), __a);}
1541
1542    _LIBCPP_INLINE_VISIBILITY
1543    static allocator_type
1544        select_on_container_copy_construction(const allocator_type& __a)
1545            {return select_on_container_copy_construction(
1546                __has_select_on_container_copy_construction<const allocator_type>(),
1547                __a);}
1548
1549    template <class _Ptr>
1550        _LIBCPP_INLINE_VISIBILITY
1551        static
1552        void
1553        __construct_forward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __begin2)
1554        {
1555            for (; __begin1 != __end1; ++__begin1, ++__begin2)
1556                construct(__a, _VSTD::__to_raw_pointer(__begin2), _VSTD::move_if_noexcept(*__begin1));
1557        }
1558
1559    template <class _Tp>
1560        _LIBCPP_INLINE_VISIBILITY
1561        static
1562        typename enable_if
1563        <
1564            (is_same<allocator_type, allocator<_Tp> >::value
1565                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1566             is_trivially_move_constructible<_Tp>::value,
1567            void
1568        >::type
1569        __construct_forward(allocator_type& __a, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
1570        {
1571            ptrdiff_t _Np = __end1 - __begin1;
1572            if (_Np > 0)
1573            {
1574                _VSTD::memcpy(__begin2, __begin1, _Np * sizeof(_Tp));
1575                __begin2 += _Np;
1576            }
1577        }
1578
1579    template <class _Iter, class _Ptr>
1580        _LIBCPP_INLINE_VISIBILITY
1581        static
1582        void
1583        __construct_range_forward(allocator_type& __a, _Iter __begin1, _Iter __end1, _Ptr& __begin2)
1584        {
1585            for (; __begin1 != __end1; ++__begin1, (void) ++__begin2)
1586                construct(__a, _VSTD::__to_raw_pointer(__begin2), *__begin1);
1587        }
1588
1589    template <class _Tp>
1590        _LIBCPP_INLINE_VISIBILITY
1591        static
1592        typename enable_if
1593        <
1594            (is_same<allocator_type, allocator<_Tp> >::value
1595                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1596             is_trivially_move_constructible<_Tp>::value,
1597            void
1598        >::type
1599        __construct_range_forward(allocator_type& __a, _Tp* __begin1, _Tp* __end1, _Tp*& __begin2)
1600        {
1601            typedef typename remove_const<_Tp>::type _Vp;
1602            ptrdiff_t _Np = __end1 - __begin1;
1603            if (_Np > 0)
1604            {
1605                _VSTD::memcpy(const_cast<_Vp*>(__begin2), __begin1, _Np * sizeof(_Tp));
1606                __begin2 += _Np;
1607            }
1608        }
1609
1610    template <class _Ptr>
1611        _LIBCPP_INLINE_VISIBILITY
1612        static
1613        void
1614        __construct_backward(allocator_type& __a, _Ptr __begin1, _Ptr __end1, _Ptr& __end2)
1615        {
1616            while (__end1 != __begin1)
1617            {
1618                construct(__a, _VSTD::__to_raw_pointer(__end2-1), _VSTD::move_if_noexcept(*--__end1));
1619                --__end2;
1620            }
1621        }
1622
1623    template <class _Tp>
1624        _LIBCPP_INLINE_VISIBILITY
1625        static
1626        typename enable_if
1627        <
1628            (is_same<allocator_type, allocator<_Tp> >::value
1629                || !__has_construct<allocator_type, _Tp*, _Tp>::value) &&
1630             is_trivially_move_constructible<_Tp>::value,
1631            void
1632        >::type
1633        __construct_backward(allocator_type& __a, _Tp* __begin1, _Tp* __end1, _Tp*& __end2)
1634        {
1635            ptrdiff_t _Np = __end1 - __begin1;
1636            __end2 -= _Np;
1637            if (_Np > 0)
1638                _VSTD::memcpy(__end2, __begin1, _Np * sizeof(_Tp));
1639        }
1640
1641private:
1642
1643    _LIBCPP_INLINE_VISIBILITY
1644    static pointer allocate(allocator_type& __a, size_type __n,
1645        const_void_pointer __hint, true_type)
1646        {return __a.allocate(__n, __hint);}
1647    _LIBCPP_INLINE_VISIBILITY
1648    static pointer allocate(allocator_type& __a, size_type __n,
1649        const_void_pointer, false_type)
1650        {return __a.allocate(__n);}
1651
1652#ifndef _LIBCPP_HAS_NO_VARIADICS
1653    template <class _Tp, class... _Args>
1654        _LIBCPP_INLINE_VISIBILITY
1655        static void __construct(true_type, allocator_type& __a, _Tp* __p, _Args&&... __args)
1656            {__a.construct(__p, _VSTD::forward<_Args>(__args)...);}
1657    template <class _Tp, class... _Args>
1658        _LIBCPP_INLINE_VISIBILITY
1659        static void __construct(false_type, allocator_type&, _Tp* __p, _Args&&... __args)
1660            {
1661                ::new ((void*)__p) _Tp(_VSTD::forward<_Args>(__args)...);
1662            }
1663#endif  // _LIBCPP_HAS_NO_VARIADICS
1664
1665    template <class _Tp>
1666        _LIBCPP_INLINE_VISIBILITY
1667        static void __destroy(true_type, allocator_type& __a, _Tp* __p)
1668            {__a.destroy(__p);}
1669    template <class _Tp>
1670        _LIBCPP_INLINE_VISIBILITY
1671        static void __destroy(false_type, allocator_type&, _Tp* __p)
1672            {
1673                __p->~_Tp();
1674            }
1675
1676    _LIBCPP_INLINE_VISIBILITY
1677    static size_type __max_size(true_type, const allocator_type& __a)
1678            {return __a.max_size();}
1679    _LIBCPP_INLINE_VISIBILITY
1680    static size_type __max_size(false_type, const allocator_type&)
1681            {return numeric_limits<size_type>::max() / sizeof(value_type);}
1682
1683    _LIBCPP_INLINE_VISIBILITY
1684    static allocator_type
1685        select_on_container_copy_construction(true_type, const allocator_type& __a)
1686            {return __a.select_on_container_copy_construction();}
1687    _LIBCPP_INLINE_VISIBILITY
1688    static allocator_type
1689        select_on_container_copy_construction(false_type, const allocator_type& __a)
1690            {return __a;}
1691};
1692
1693template <class _Traits, class _Tp>
1694struct __rebind_alloc_helper
1695{
1696#ifndef _LIBCPP_HAS_NO_TEMPLATE_ALIASES
1697    typedef typename _Traits::template rebind_alloc<_Tp>        type;
1698#else
1699    typedef typename _Traits::template rebind_alloc<_Tp>::other type;
1700#endif
1701};
1702
1703// allocator
1704
1705template <class _Tp>
1706class _LIBCPP_TYPE_VIS_ONLY allocator
1707{
1708public:
1709    typedef size_t            size_type;
1710    typedef ptrdiff_t         difference_type;
1711    typedef _Tp*              pointer;
1712    typedef const _Tp*        const_pointer;
1713    typedef _Tp&              reference;
1714    typedef const _Tp&        const_reference;
1715    typedef _Tp               value_type;
1716
1717    typedef true_type propagate_on_container_move_assignment;
1718    typedef true_type is_always_equal;
1719
1720    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1721
1722    _LIBCPP_INLINE_VISIBILITY allocator() _NOEXCEPT {}
1723    template <class _Up> _LIBCPP_INLINE_VISIBILITY allocator(const allocator<_Up>&) _NOEXCEPT {}
1724    _LIBCPP_INLINE_VISIBILITY pointer address(reference __x) const _NOEXCEPT
1725        {return _VSTD::addressof(__x);}
1726    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1727        {return _VSTD::addressof(__x);}
1728    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1729        {return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));}
1730    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
1731        {_VSTD::__deallocate((void*)__p);}
1732    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1733        {return size_type(~0) / sizeof(_Tp);}
1734#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1735    template <class _Up, class... _Args>
1736        _LIBCPP_INLINE_VISIBILITY
1737        void
1738        construct(_Up* __p, _Args&&... __args)
1739        {
1740            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1741        }
1742#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1743        _LIBCPP_INLINE_VISIBILITY
1744        void
1745        construct(pointer __p)
1746        {
1747            ::new((void*)__p) _Tp();
1748        }
1749# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1750
1751    template <class _A0>
1752        _LIBCPP_INLINE_VISIBILITY
1753        void
1754        construct(pointer __p, _A0& __a0)
1755        {
1756            ::new((void*)__p) _Tp(__a0);
1757        }
1758    template <class _A0>
1759        _LIBCPP_INLINE_VISIBILITY
1760        void
1761        construct(pointer __p, const _A0& __a0)
1762        {
1763            ::new((void*)__p) _Tp(__a0);
1764        }
1765# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1766    template <class _A0, class _A1>
1767        _LIBCPP_INLINE_VISIBILITY
1768        void
1769        construct(pointer __p, _A0& __a0, _A1& __a1)
1770        {
1771            ::new((void*)__p) _Tp(__a0, __a1);
1772        }
1773    template <class _A0, class _A1>
1774        _LIBCPP_INLINE_VISIBILITY
1775        void
1776        construct(pointer __p, const _A0& __a0, _A1& __a1)
1777        {
1778            ::new((void*)__p) _Tp(__a0, __a1);
1779        }
1780    template <class _A0, class _A1>
1781        _LIBCPP_INLINE_VISIBILITY
1782        void
1783        construct(pointer __p, _A0& __a0, const _A1& __a1)
1784        {
1785            ::new((void*)__p) _Tp(__a0, __a1);
1786        }
1787    template <class _A0, class _A1>
1788        _LIBCPP_INLINE_VISIBILITY
1789        void
1790        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1791        {
1792            ::new((void*)__p) _Tp(__a0, __a1);
1793        }
1794#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1795    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1796};
1797
1798template <class _Tp>
1799class _LIBCPP_TYPE_VIS_ONLY allocator<const _Tp>
1800{
1801public:
1802    typedef size_t            size_type;
1803    typedef ptrdiff_t         difference_type;
1804    typedef const _Tp*        pointer;
1805    typedef const _Tp*        const_pointer;
1806    typedef const _Tp&        reference;
1807    typedef const _Tp&        const_reference;
1808    typedef const _Tp         value_type;
1809
1810    typedef true_type propagate_on_container_move_assignment;
1811    typedef true_type is_always_equal;
1812
1813    template <class _Up> struct rebind {typedef allocator<_Up> other;};
1814
1815    _LIBCPP_INLINE_VISIBILITY allocator() _NOEXCEPT {}
1816    template <class _Up> _LIBCPP_INLINE_VISIBILITY allocator(const allocator<_Up>&) _NOEXCEPT {}
1817    _LIBCPP_INLINE_VISIBILITY const_pointer address(const_reference __x) const _NOEXCEPT
1818        {return _VSTD::addressof(__x);}
1819    _LIBCPP_INLINE_VISIBILITY pointer allocate(size_type __n, allocator<void>::const_pointer = 0)
1820        {return static_cast<pointer>(_VSTD::__allocate(__n * sizeof(_Tp)));}
1821    _LIBCPP_INLINE_VISIBILITY void deallocate(pointer __p, size_type) _NOEXCEPT
1822        {_VSTD::__deallocate((void*)__p);}
1823    _LIBCPP_INLINE_VISIBILITY size_type max_size() const _NOEXCEPT
1824        {return size_type(~0) / sizeof(_Tp);}
1825#if !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1826    template <class _Up, class... _Args>
1827        _LIBCPP_INLINE_VISIBILITY
1828        void
1829        construct(_Up* __p, _Args&&... __args)
1830        {
1831            ::new((void*)__p) _Up(_VSTD::forward<_Args>(__args)...);
1832        }
1833#else  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1834        _LIBCPP_INLINE_VISIBILITY
1835        void
1836        construct(pointer __p)
1837        {
1838            ::new((void*)__p) _Tp();
1839        }
1840# if defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1841
1842    template <class _A0>
1843        _LIBCPP_INLINE_VISIBILITY
1844        void
1845        construct(pointer __p, _A0& __a0)
1846        {
1847            ::new((void*)__p) _Tp(__a0);
1848        }
1849    template <class _A0>
1850        _LIBCPP_INLINE_VISIBILITY
1851        void
1852        construct(pointer __p, const _A0& __a0)
1853        {
1854            ::new((void*)__p) _Tp(__a0);
1855        }
1856# endif  // defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
1857    template <class _A0, class _A1>
1858        _LIBCPP_INLINE_VISIBILITY
1859        void
1860        construct(pointer __p, _A0& __a0, _A1& __a1)
1861        {
1862            ::new((void*)__p) _Tp(__a0, __a1);
1863        }
1864    template <class _A0, class _A1>
1865        _LIBCPP_INLINE_VISIBILITY
1866        void
1867        construct(pointer __p, const _A0& __a0, _A1& __a1)
1868        {
1869            ::new((void*)__p) _Tp(__a0, __a1);
1870        }
1871    template <class _A0, class _A1>
1872        _LIBCPP_INLINE_VISIBILITY
1873        void
1874        construct(pointer __p, _A0& __a0, const _A1& __a1)
1875        {
1876            ::new((void*)__p) _Tp(__a0, __a1);
1877        }
1878    template <class _A0, class _A1>
1879        _LIBCPP_INLINE_VISIBILITY
1880        void
1881        construct(pointer __p, const _A0& __a0, const _A1& __a1)
1882        {
1883            ::new((void*)__p) _Tp(__a0, __a1);
1884        }
1885#endif  // !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES) && !defined(_LIBCPP_HAS_NO_VARIADICS)
1886    _LIBCPP_INLINE_VISIBILITY void destroy(pointer __p) {__p->~_Tp();}
1887};
1888
1889template <class _Tp, class _Up>
1890inline _LIBCPP_INLINE_VISIBILITY
1891bool operator==(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return true;}
1892
1893template <class _Tp, class _Up>
1894inline _LIBCPP_INLINE_VISIBILITY
1895bool operator!=(const allocator<_Tp>&, const allocator<_Up>&) _NOEXCEPT {return false;}
1896
1897template <class _OutputIterator, class _Tp>
1898class _LIBCPP_TYPE_VIS_ONLY raw_storage_iterator
1899    : public iterator<output_iterator_tag,
1900                      _Tp,                                         // purposefully not C++03
1901                      ptrdiff_t,                                   // purposefully not C++03
1902                      _Tp*,                                        // purposefully not C++03
1903                      raw_storage_iterator<_OutputIterator, _Tp>&> // purposefully not C++03
1904{
1905private:
1906    _OutputIterator __x_;
1907public:
1908    _LIBCPP_INLINE_VISIBILITY explicit raw_storage_iterator(_OutputIterator __x) : __x_(__x) {}
1909    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator*() {return *this;}
1910    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(const _Tp& __element)
1911        {::new(&*__x_) _Tp(__element); return *this;}
1912#if _LIBCPP_STD_VER >= 14
1913    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator=(_Tp&& __element)
1914        {::new(&*__x_) _Tp(_VSTD::move(__element)); return *this;}
1915#endif
1916    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator& operator++() {++__x_; return *this;}
1917    _LIBCPP_INLINE_VISIBILITY raw_storage_iterator  operator++(int)
1918        {raw_storage_iterator __t(*this); ++__x_; return __t;}
1919#if _LIBCPP_STD_VER >= 14
1920    _LIBCPP_INLINE_VISIBILITY _OutputIterator base() const { return __x_; }
1921#endif
1922};
1923
1924template <class _Tp>
1925pair<_Tp*, ptrdiff_t>
1926get_temporary_buffer(ptrdiff_t __n) _NOEXCEPT
1927{
1928    pair<_Tp*, ptrdiff_t> __r(0, 0);
1929    const ptrdiff_t __m = (~ptrdiff_t(0) ^
1930                           ptrdiff_t(ptrdiff_t(1) << (sizeof(ptrdiff_t) * __CHAR_BIT__ - 1)))
1931                           / sizeof(_Tp);
1932    if (__n > __m)
1933        __n = __m;
1934    while (__n > 0)
1935    {
1936        __r.first = static_cast<_Tp*>(::operator new(__n * sizeof(_Tp), nothrow));
1937        if (__r.first)
1938        {
1939            __r.second = __n;
1940            break;
1941        }
1942        __n /= 2;
1943    }
1944    return __r;
1945}
1946
1947template <class _Tp>
1948inline _LIBCPP_INLINE_VISIBILITY
1949void return_temporary_buffer(_Tp* __p) _NOEXCEPT {::operator delete(__p);}
1950
1951template <class _Tp>
1952struct auto_ptr_ref
1953{
1954    _Tp* __ptr_;
1955};
1956
1957template<class _Tp>
1958class _LIBCPP_TYPE_VIS_ONLY auto_ptr
1959{
1960private:
1961    _Tp* __ptr_;
1962public:
1963    typedef _Tp element_type;
1964
1965    _LIBCPP_INLINE_VISIBILITY explicit auto_ptr(_Tp* __p = 0) throw() : __ptr_(__p) {}
1966    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr& __p) throw() : __ptr_(__p.release()) {}
1967    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr<_Up>& __p) throw()
1968        : __ptr_(__p.release()) {}
1969    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr& __p) throw()
1970        {reset(__p.release()); return *this;}
1971    template<class _Up> _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr<_Up>& __p) throw()
1972        {reset(__p.release()); return *this;}
1973    _LIBCPP_INLINE_VISIBILITY auto_ptr& operator=(auto_ptr_ref<_Tp> __p) throw()
1974        {reset(__p.__ptr_); return *this;}
1975    _LIBCPP_INLINE_VISIBILITY ~auto_ptr() throw() {delete __ptr_;}
1976
1977    _LIBCPP_INLINE_VISIBILITY _Tp& operator*() const throw()
1978        {return *__ptr_;}
1979    _LIBCPP_INLINE_VISIBILITY _Tp* operator->() const throw() {return __ptr_;}
1980    _LIBCPP_INLINE_VISIBILITY _Tp* get() const throw() {return __ptr_;}
1981    _LIBCPP_INLINE_VISIBILITY _Tp* release() throw()
1982    {
1983        _Tp* __t = __ptr_;
1984        __ptr_ = 0;
1985        return __t;
1986    }
1987    _LIBCPP_INLINE_VISIBILITY void reset(_Tp* __p = 0) throw()
1988    {
1989        if (__ptr_ != __p)
1990            delete __ptr_;
1991        __ptr_ = __p;
1992    }
1993
1994    _LIBCPP_INLINE_VISIBILITY auto_ptr(auto_ptr_ref<_Tp> __p) throw() : __ptr_(__p.__ptr_) {}
1995    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr_ref<_Up>() throw()
1996        {auto_ptr_ref<_Up> __t; __t.__ptr_ = release(); return __t;}
1997    template<class _Up> _LIBCPP_INLINE_VISIBILITY operator auto_ptr<_Up>() throw()
1998        {return auto_ptr<_Up>(release());}
1999};
2000
2001template <>
2002class _LIBCPP_TYPE_VIS_ONLY auto_ptr<void>
2003{
2004public:
2005    typedef void element_type;
2006};
2007
2008template <class _T1, class _T2, bool = is_same<typename remove_cv<_T1>::type,
2009                                                     typename remove_cv<_T2>::type>::value,
2010                                bool = is_empty<_T1>::value
2011                                       && !__libcpp_is_final<_T1>::value,
2012                                bool = is_empty<_T2>::value
2013                                       && !__libcpp_is_final<_T2>::value
2014         >
2015struct __libcpp_compressed_pair_switch;
2016
2017template <class _T1, class _T2, bool IsSame>
2018struct __libcpp_compressed_pair_switch<_T1, _T2, IsSame, false, false> {enum {value = 0};};
2019
2020template <class _T1, class _T2, bool IsSame>
2021struct __libcpp_compressed_pair_switch<_T1, _T2, IsSame, true, false>  {enum {value = 1};};
2022
2023template <class _T1, class _T2, bool IsSame>
2024struct __libcpp_compressed_pair_switch<_T1, _T2, IsSame, false, true>  {enum {value = 2};};
2025
2026template <class _T1, class _T2>
2027struct __libcpp_compressed_pair_switch<_T1, _T2, false, true, true>    {enum {value = 3};};
2028
2029template <class _T1, class _T2>
2030struct __libcpp_compressed_pair_switch<_T1, _T2, true, true, true>     {enum {value = 1};};
2031
2032template <class _T1, class _T2, unsigned = __libcpp_compressed_pair_switch<_T1, _T2>::value>
2033class __libcpp_compressed_pair_imp;
2034
2035template <class _T1, class _T2>
2036class __libcpp_compressed_pair_imp<_T1, _T2, 0>
2037{
2038private:
2039    _T1 __first_;
2040    _T2 __second_;
2041public:
2042    typedef _T1 _T1_param;
2043    typedef _T2 _T2_param;
2044
2045    typedef typename remove_reference<_T1>::type& _T1_reference;
2046    typedef typename remove_reference<_T2>::type& _T2_reference;
2047
2048    typedef const typename remove_reference<_T1>::type& _T1_const_reference;
2049    typedef const typename remove_reference<_T2>::type& _T2_const_reference;
2050
2051    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() : __first_(), __second_() {}
2052    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
2053        : __first_(_VSTD::forward<_T1_param>(__t1)), __second_() {}
2054    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
2055        : __first_(), __second_(_VSTD::forward<_T2_param>(__t2)) {}
2056    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
2057        : __first_(_VSTD::forward<_T1_param>(__t1)), __second_(_VSTD::forward<_T2_param>(__t2)) {}
2058
2059#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2060
2061    _LIBCPP_INLINE_VISIBILITY
2062    __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
2063        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
2064                   is_nothrow_copy_constructible<_T2>::value)
2065        : __first_(__p.first()),
2066          __second_(__p.second()) {}
2067
2068    _LIBCPP_INLINE_VISIBILITY
2069    __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
2070        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
2071                   is_nothrow_copy_assignable<_T2>::value)
2072        {
2073            __first_ = __p.first();
2074            __second_ = __p.second();
2075            return *this;
2076        }
2077
2078    _LIBCPP_INLINE_VISIBILITY
2079    __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
2080        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
2081                   is_nothrow_move_constructible<_T2>::value)
2082        : __first_(_VSTD::forward<_T1>(__p.first())),
2083          __second_(_VSTD::forward<_T2>(__p.second())) {}
2084
2085    _LIBCPP_INLINE_VISIBILITY
2086    __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
2087        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
2088                   is_nothrow_move_assignable<_T2>::value)
2089        {
2090            __first_ = _VSTD::forward<_T1>(__p.first());
2091            __second_ = _VSTD::forward<_T2>(__p.second());
2092            return *this;
2093        }
2094
2095#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2096
2097#ifndef _LIBCPP_HAS_NO_VARIADICS
2098
2099    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
2100        _LIBCPP_INLINE_VISIBILITY
2101        __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
2102                                     tuple<_Args1...> __first_args,
2103                                     tuple<_Args2...> __second_args,
2104                                     __tuple_indices<_I1...>,
2105                                     __tuple_indices<_I2...>)
2106            : __first_(_VSTD::forward<_Args1>(_VSTD::get<_I1>(__first_args))...),
2107              __second_(_VSTD::forward<_Args2>(_VSTD::get<_I2>(__second_args))...)
2108            {}
2109
2110#endif  // _LIBCPP_HAS_NO_VARIADICS
2111
2112    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return __first_;}
2113    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return __first_;}
2114
2115    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return __second_;}
2116    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return __second_;}
2117
2118    _LIBCPP_INLINE_VISIBILITY void swap(__libcpp_compressed_pair_imp& __x)
2119        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2120                   __is_nothrow_swappable<_T2>::value)
2121    {
2122        using _VSTD::swap;
2123        swap(__first_, __x.__first_);
2124        swap(__second_, __x.__second_);
2125    }
2126};
2127
2128template <class _T1, class _T2>
2129class __libcpp_compressed_pair_imp<_T1, _T2, 1>
2130    : private _T1
2131{
2132private:
2133    _T2 __second_;
2134public:
2135    typedef _T1 _T1_param;
2136    typedef _T2 _T2_param;
2137
2138    typedef _T1&                                        _T1_reference;
2139    typedef typename remove_reference<_T2>::type& _T2_reference;
2140
2141    typedef const _T1&                                        _T1_const_reference;
2142    typedef const typename remove_reference<_T2>::type& _T2_const_reference;
2143
2144    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() : __second_() {}
2145    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
2146        : _T1(_VSTD::forward<_T1_param>(__t1)), __second_() {}
2147    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
2148        : __second_(_VSTD::forward<_T2_param>(__t2)) {}
2149    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
2150        : _T1(_VSTD::forward<_T1_param>(__t1)), __second_(_VSTD::forward<_T2_param>(__t2)) {}
2151
2152#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2153
2154    _LIBCPP_INLINE_VISIBILITY
2155    __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
2156        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
2157                   is_nothrow_copy_constructible<_T2>::value)
2158        : _T1(__p.first()), __second_(__p.second()) {}
2159
2160    _LIBCPP_INLINE_VISIBILITY
2161    __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
2162        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
2163                   is_nothrow_copy_assignable<_T2>::value)
2164        {
2165            _T1::operator=(__p.first());
2166            __second_ = __p.second();
2167            return *this;
2168        }
2169
2170    _LIBCPP_INLINE_VISIBILITY
2171    __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
2172        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
2173                   is_nothrow_move_constructible<_T2>::value)
2174        : _T1(_VSTD::move(__p.first())), __second_(_VSTD::forward<_T2>(__p.second())) {}
2175
2176    _LIBCPP_INLINE_VISIBILITY
2177    __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
2178        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
2179                   is_nothrow_move_assignable<_T2>::value)
2180        {
2181            _T1::operator=(_VSTD::move(__p.first()));
2182            __second_ = _VSTD::forward<_T2>(__p.second());
2183            return *this;
2184        }
2185
2186#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2187
2188#ifndef _LIBCPP_HAS_NO_VARIADICS
2189
2190    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
2191        _LIBCPP_INLINE_VISIBILITY
2192        __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
2193                                     tuple<_Args1...> __first_args,
2194                                     tuple<_Args2...> __second_args,
2195                                     __tuple_indices<_I1...>,
2196                                     __tuple_indices<_I2...>)
2197            : _T1(_VSTD::forward<_Args1>(_VSTD::get<_I1>(__first_args))...),
2198              __second_(_VSTD::forward<_Args2>(_VSTD::get<_I2>(__second_args))...)
2199            {}
2200
2201#endif  // _LIBCPP_HAS_NO_VARIADICS
2202
2203    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return *this;}
2204    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return *this;}
2205
2206    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return __second_;}
2207    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return __second_;}
2208
2209    _LIBCPP_INLINE_VISIBILITY void swap(__libcpp_compressed_pair_imp& __x)
2210        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2211                   __is_nothrow_swappable<_T2>::value)
2212    {
2213        using _VSTD::swap;
2214        swap(__second_, __x.__second_);
2215    }
2216};
2217
2218template <class _T1, class _T2>
2219class __libcpp_compressed_pair_imp<_T1, _T2, 2>
2220    : private _T2
2221{
2222private:
2223    _T1 __first_;
2224public:
2225    typedef _T1 _T1_param;
2226    typedef _T2 _T2_param;
2227
2228    typedef typename remove_reference<_T1>::type& _T1_reference;
2229    typedef _T2&                                        _T2_reference;
2230
2231    typedef const typename remove_reference<_T1>::type& _T1_const_reference;
2232    typedef const _T2&                                        _T2_const_reference;
2233
2234    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() : __first_() {}
2235    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
2236        : __first_(_VSTD::forward<_T1_param>(__t1)) {}
2237    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
2238        : _T2(_VSTD::forward<_T2_param>(__t2)), __first_() {}
2239    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
2240        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
2241                   is_nothrow_move_constructible<_T2>::value)
2242        : _T2(_VSTD::forward<_T2_param>(__t2)), __first_(_VSTD::forward<_T1_param>(__t1)) {}
2243
2244#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2245
2246    _LIBCPP_INLINE_VISIBILITY
2247    __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
2248        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
2249                   is_nothrow_copy_constructible<_T2>::value)
2250        : _T2(__p.second()), __first_(__p.first()) {}
2251
2252    _LIBCPP_INLINE_VISIBILITY
2253    __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
2254        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
2255                   is_nothrow_copy_assignable<_T2>::value)
2256        {
2257            _T2::operator=(__p.second());
2258            __first_ = __p.first();
2259            return *this;
2260        }
2261
2262    _LIBCPP_INLINE_VISIBILITY
2263    __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
2264        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
2265                   is_nothrow_move_constructible<_T2>::value)
2266        : _T2(_VSTD::forward<_T2>(__p.second())), __first_(_VSTD::move(__p.first())) {}
2267
2268    _LIBCPP_INLINE_VISIBILITY
2269    __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
2270        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
2271                   is_nothrow_move_assignable<_T2>::value)
2272        {
2273            _T2::operator=(_VSTD::forward<_T2>(__p.second()));
2274            __first_ = _VSTD::move(__p.first());
2275            return *this;
2276        }
2277
2278#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2279
2280#ifndef _LIBCPP_HAS_NO_VARIADICS
2281
2282    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
2283        _LIBCPP_INLINE_VISIBILITY
2284        __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
2285                                     tuple<_Args1...> __first_args,
2286                                     tuple<_Args2...> __second_args,
2287                                     __tuple_indices<_I1...>,
2288                                     __tuple_indices<_I2...>)
2289            : _T2(_VSTD::forward<_Args2>(_VSTD::get<_I2>(__second_args))...),
2290              __first_(_VSTD::forward<_Args1>(_VSTD::get<_I1>(__first_args))...)
2291
2292            {}
2293
2294#endif  // _LIBCPP_HAS_NO_VARIADICS
2295
2296    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return __first_;}
2297    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return __first_;}
2298
2299    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return *this;}
2300    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return *this;}
2301
2302    _LIBCPP_INLINE_VISIBILITY void swap(__libcpp_compressed_pair_imp& __x)
2303        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2304                   __is_nothrow_swappable<_T2>::value)
2305    {
2306        using _VSTD::swap;
2307        swap(__first_, __x.__first_);
2308    }
2309};
2310
2311template <class _T1, class _T2>
2312class __libcpp_compressed_pair_imp<_T1, _T2, 3>
2313    : private _T1,
2314      private _T2
2315{
2316public:
2317    typedef _T1 _T1_param;
2318    typedef _T2 _T2_param;
2319
2320    typedef _T1& _T1_reference;
2321    typedef _T2& _T2_reference;
2322
2323    typedef const _T1& _T1_const_reference;
2324    typedef const _T2& _T2_const_reference;
2325
2326    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp() {}
2327    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T1_param __t1)
2328        : _T1(_VSTD::forward<_T1_param>(__t1)) {}
2329    _LIBCPP_INLINE_VISIBILITY explicit __libcpp_compressed_pair_imp(_T2_param __t2)
2330        : _T2(_VSTD::forward<_T2_param>(__t2)) {}
2331    _LIBCPP_INLINE_VISIBILITY __libcpp_compressed_pair_imp(_T1_param __t1, _T2_param __t2)
2332        : _T1(_VSTD::forward<_T1_param>(__t1)), _T2(_VSTD::forward<_T2_param>(__t2)) {}
2333
2334#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2335
2336    _LIBCPP_INLINE_VISIBILITY
2337    __libcpp_compressed_pair_imp(const __libcpp_compressed_pair_imp& __p)
2338        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
2339                   is_nothrow_copy_constructible<_T2>::value)
2340        : _T1(__p.first()), _T2(__p.second()) {}
2341
2342    _LIBCPP_INLINE_VISIBILITY
2343    __libcpp_compressed_pair_imp& operator=(const __libcpp_compressed_pair_imp& __p)
2344        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
2345                   is_nothrow_copy_assignable<_T2>::value)
2346        {
2347            _T1::operator=(__p.first());
2348            _T2::operator=(__p.second());
2349            return *this;
2350        }
2351
2352    _LIBCPP_INLINE_VISIBILITY
2353    __libcpp_compressed_pair_imp(__libcpp_compressed_pair_imp&& __p)
2354        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
2355                   is_nothrow_move_constructible<_T2>::value)
2356        : _T1(_VSTD::move(__p.first())), _T2(_VSTD::move(__p.second())) {}
2357
2358    _LIBCPP_INLINE_VISIBILITY
2359    __libcpp_compressed_pair_imp& operator=(__libcpp_compressed_pair_imp&& __p)
2360        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
2361                   is_nothrow_move_assignable<_T2>::value)
2362        {
2363            _T1::operator=(_VSTD::move(__p.first()));
2364            _T2::operator=(_VSTD::move(__p.second()));
2365            return *this;
2366        }
2367
2368#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2369
2370#ifndef _LIBCPP_HAS_NO_VARIADICS
2371
2372    template <class... _Args1, class... _Args2, size_t... _I1, size_t... _I2>
2373        _LIBCPP_INLINE_VISIBILITY
2374        __libcpp_compressed_pair_imp(piecewise_construct_t __pc,
2375                                     tuple<_Args1...> __first_args,
2376                                     tuple<_Args2...> __second_args,
2377                                     __tuple_indices<_I1...>,
2378                                     __tuple_indices<_I2...>)
2379            : _T1(_VSTD::forward<_Args1>(_VSTD::get<_I1>(__first_args))...),
2380              _T2(_VSTD::forward<_Args2>(_VSTD::get<_I2>(__second_args))...)
2381            {}
2382
2383#endif  // _LIBCPP_HAS_NO_VARIADICS
2384
2385    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return *this;}
2386    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return *this;}
2387
2388    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return *this;}
2389    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return *this;}
2390
2391    _LIBCPP_INLINE_VISIBILITY void swap(__libcpp_compressed_pair_imp&)
2392        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2393                   __is_nothrow_swappable<_T2>::value)
2394    {
2395    }
2396};
2397
2398template <class _T1, class _T2>
2399class __compressed_pair
2400    : private __libcpp_compressed_pair_imp<_T1, _T2>
2401{
2402    typedef __libcpp_compressed_pair_imp<_T1, _T2> base;
2403public:
2404    typedef typename base::_T1_param _T1_param;
2405    typedef typename base::_T2_param _T2_param;
2406
2407    typedef typename base::_T1_reference _T1_reference;
2408    typedef typename base::_T2_reference _T2_reference;
2409
2410    typedef typename base::_T1_const_reference _T1_const_reference;
2411    typedef typename base::_T2_const_reference _T2_const_reference;
2412
2413    _LIBCPP_INLINE_VISIBILITY __compressed_pair() {}
2414    _LIBCPP_INLINE_VISIBILITY explicit __compressed_pair(_T1_param __t1)
2415        : base(_VSTD::forward<_T1_param>(__t1)) {}
2416    _LIBCPP_INLINE_VISIBILITY explicit __compressed_pair(_T2_param __t2)
2417        : base(_VSTD::forward<_T2_param>(__t2)) {}
2418    _LIBCPP_INLINE_VISIBILITY __compressed_pair(_T1_param __t1, _T2_param __t2)
2419        : base(_VSTD::forward<_T1_param>(__t1), _VSTD::forward<_T2_param>(__t2)) {}
2420
2421#if defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2422
2423    _LIBCPP_INLINE_VISIBILITY
2424    __compressed_pair(const __compressed_pair& __p)
2425        _NOEXCEPT_(is_nothrow_copy_constructible<_T1>::value &&
2426                   is_nothrow_copy_constructible<_T2>::value)
2427        : base(__p) {}
2428
2429    _LIBCPP_INLINE_VISIBILITY
2430    __compressed_pair& operator=(const __compressed_pair& __p)
2431        _NOEXCEPT_(is_nothrow_copy_assignable<_T1>::value &&
2432                   is_nothrow_copy_assignable<_T2>::value)
2433        {
2434            base::operator=(__p);
2435            return *this;
2436        }
2437
2438    _LIBCPP_INLINE_VISIBILITY
2439    __compressed_pair(__compressed_pair&& __p)
2440        _NOEXCEPT_(is_nothrow_move_constructible<_T1>::value &&
2441                   is_nothrow_move_constructible<_T2>::value)
2442        : base(_VSTD::move(__p)) {}
2443
2444    _LIBCPP_INLINE_VISIBILITY
2445    __compressed_pair& operator=(__compressed_pair&& __p)
2446        _NOEXCEPT_(is_nothrow_move_assignable<_T1>::value &&
2447                   is_nothrow_move_assignable<_T2>::value)
2448        {
2449            base::operator=(_VSTD::move(__p));
2450            return *this;
2451        }
2452
2453#endif  // defined(_LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS) && !defined(_LIBCPP_HAS_NO_RVALUE_REFERENCES)
2454
2455#ifndef _LIBCPP_HAS_NO_VARIADICS
2456
2457    template <class... _Args1, class... _Args2>
2458        _LIBCPP_INLINE_VISIBILITY
2459        __compressed_pair(piecewise_construct_t __pc, tuple<_Args1...> __first_args,
2460                                                      tuple<_Args2...> __second_args)
2461            : base(__pc, _VSTD::move(__first_args), _VSTD::move(__second_args),
2462                   typename __make_tuple_indices<sizeof...(_Args1)>::type(),
2463                   typename __make_tuple_indices<sizeof...(_Args2) >::type())
2464            {}
2465
2466#endif  // _LIBCPP_HAS_NO_VARIADICS
2467
2468    _LIBCPP_INLINE_VISIBILITY _T1_reference       first() _NOEXCEPT       {return base::first();}
2469    _LIBCPP_INLINE_VISIBILITY _T1_const_reference first() const _NOEXCEPT {return base::first();}
2470
2471    _LIBCPP_INLINE_VISIBILITY _T2_reference       second() _NOEXCEPT       {return base::second();}
2472    _LIBCPP_INLINE_VISIBILITY _T2_const_reference second() const _NOEXCEPT {return base::second();}
2473
2474    _LIBCPP_INLINE_VISIBILITY void swap(__compressed_pair& __x)
2475        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2476                   __is_nothrow_swappable<_T2>::value)
2477        {base::swap(__x);}
2478};
2479
2480template <class _T1, class _T2>
2481inline _LIBCPP_INLINE_VISIBILITY
2482void
2483swap(__compressed_pair<_T1, _T2>& __x, __compressed_pair<_T1, _T2>& __y)
2484        _NOEXCEPT_(__is_nothrow_swappable<_T1>::value &&
2485                   __is_nothrow_swappable<_T2>::value)
2486    {__x.swap(__y);}
2487
2488// __same_or_less_cv_qualified
2489
2490template <class _Ptr1, class _Ptr2,
2491          bool = is_same<typename remove_cv<typename pointer_traits<_Ptr1>::element_type>::type,
2492                         typename remove_cv<typename pointer_traits<_Ptr2>::element_type>::type
2493                        >::value
2494         >
2495struct __same_or_less_cv_qualified_imp
2496    : is_convertible<_Ptr1, _Ptr2> {};
2497
2498template <class _Ptr1, class _Ptr2>
2499struct __same_or_less_cv_qualified_imp<_Ptr1, _Ptr2, false>
2500    : false_type {};
2501
2502template <class _Ptr1, class _Ptr2, bool = is_pointer<_Ptr1>::value ||
2503                                           is_same<_Ptr1, _Ptr2>::value ||
2504                                           __has_element_type<_Ptr1>::value>
2505struct __same_or_less_cv_qualified
2506    : __same_or_less_cv_qualified_imp<_Ptr1, _Ptr2> {};
2507
2508template <class _Ptr1, class _Ptr2>
2509struct __same_or_less_cv_qualified<_Ptr1, _Ptr2, false>
2510    : false_type {};
2511
2512// default_delete
2513
2514template <class _Tp>
2515struct _LIBCPP_TYPE_VIS_ONLY default_delete
2516{
2517#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
2518    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR default_delete() _NOEXCEPT = default;
2519#else
2520    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR default_delete() _NOEXCEPT {}
2521#endif
2522    template <class _Up>
2523        _LIBCPP_INLINE_VISIBILITY default_delete(const default_delete<_Up>&,
2524             typename enable_if<is_convertible<_Up*, _Tp*>::value>::type* = 0) _NOEXCEPT {}
2525    _LIBCPP_INLINE_VISIBILITY void operator() (_Tp* __ptr) const _NOEXCEPT
2526        {
2527            static_assert(sizeof(_Tp) > 0, "default_delete can not delete incomplete type");
2528            static_assert(!is_void<_Tp>::value, "default_delete can not delete incomplete type");
2529            delete __ptr;
2530        }
2531};
2532
2533template <class _Tp>
2534struct _LIBCPP_TYPE_VIS_ONLY default_delete<_Tp[]>
2535{
2536public:
2537#ifndef _LIBCPP_HAS_NO_DEFAULTED_FUNCTIONS
2538    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR default_delete() _NOEXCEPT = default;
2539#else
2540    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR default_delete() _NOEXCEPT {}
2541#endif
2542    template <class _Up>
2543        _LIBCPP_INLINE_VISIBILITY default_delete(const default_delete<_Up[]>&,
2544             typename enable_if<__same_or_less_cv_qualified<_Up*, _Tp*>::value>::type* = 0) _NOEXCEPT {}
2545    template <class _Up>
2546        _LIBCPP_INLINE_VISIBILITY
2547        void operator() (_Up* __ptr,
2548                         typename enable_if<__same_or_less_cv_qualified<_Up*, _Tp*>::value>::type* = 0) const _NOEXCEPT
2549        {
2550            static_assert(sizeof(_Tp) > 0, "default_delete can not delete incomplete type");
2551            static_assert(!is_void<_Tp>::value, "default_delete can not delete incomplete type");
2552            delete [] __ptr;
2553        }
2554};
2555
2556template <class _Tp, class _Dp = default_delete<_Tp> >
2557class _LIBCPP_TYPE_VIS_ONLY unique_ptr
2558{
2559public:
2560    typedef _Tp element_type;
2561    typedef _Dp deleter_type;
2562    typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2563private:
2564    __compressed_pair<pointer, deleter_type> __ptr_;
2565
2566#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2567    unique_ptr(unique_ptr&);
2568    template <class _Up, class _Ep>
2569        unique_ptr(unique_ptr<_Up, _Ep>&);
2570    unique_ptr& operator=(unique_ptr&);
2571    template <class _Up, class _Ep>
2572        unique_ptr& operator=(unique_ptr<_Up, _Ep>&);
2573#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2574
2575    struct __nat {int __for_bool_;};
2576
2577    typedef       typename remove_reference<deleter_type>::type& _Dp_reference;
2578    typedef const typename remove_reference<deleter_type>::type& _Dp_const_reference;
2579public:
2580    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT
2581        : __ptr_(pointer())
2582        {
2583            static_assert(!is_pointer<deleter_type>::value,
2584                "unique_ptr constructed with null function pointer deleter");
2585        }
2586    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT
2587        : __ptr_(pointer())
2588        {
2589            static_assert(!is_pointer<deleter_type>::value,
2590                "unique_ptr constructed with null function pointer deleter");
2591        }
2592    _LIBCPP_INLINE_VISIBILITY explicit unique_ptr(pointer __p) _NOEXCEPT
2593        : __ptr_(_VSTD::move(__p))
2594        {
2595            static_assert(!is_pointer<deleter_type>::value,
2596                "unique_ptr constructed with null function pointer deleter");
2597        }
2598
2599#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2600    _LIBCPP_INLINE_VISIBILITY unique_ptr(pointer __p, typename conditional<
2601                                        is_reference<deleter_type>::value,
2602                                        deleter_type,
2603                                        typename add_lvalue_reference<const deleter_type>::type>::type __d)
2604             _NOEXCEPT
2605        : __ptr_(__p, __d) {}
2606
2607    _LIBCPP_INLINE_VISIBILITY unique_ptr(pointer __p, typename remove_reference<deleter_type>::type&& __d)
2608             _NOEXCEPT
2609        : __ptr_(__p, _VSTD::move(__d))
2610        {
2611            static_assert(!is_reference<deleter_type>::value, "rvalue deleter bound to reference");
2612        }
2613    _LIBCPP_INLINE_VISIBILITY unique_ptr(unique_ptr&& __u) _NOEXCEPT
2614        : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {}
2615    template <class _Up, class _Ep>
2616        _LIBCPP_INLINE_VISIBILITY
2617        unique_ptr(unique_ptr<_Up, _Ep>&& __u,
2618                   typename enable_if
2619                      <
2620                        !is_array<_Up>::value &&
2621                         is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value &&
2622                         is_convertible<_Ep, deleter_type>::value &&
2623                         (
2624                            !is_reference<deleter_type>::value ||
2625                            is_same<deleter_type, _Ep>::value
2626                         ),
2627                         __nat
2628                      >::type = __nat()) _NOEXCEPT
2629            : __ptr_(__u.release(), _VSTD::forward<_Ep>(__u.get_deleter())) {}
2630
2631    template <class _Up>
2632        _LIBCPP_INLINE_VISIBILITY unique_ptr(auto_ptr<_Up>&& __p,
2633                typename enable_if<
2634                                      is_convertible<_Up*, _Tp*>::value &&
2635                                      is_same<_Dp, default_delete<_Tp> >::value,
2636                                      __nat
2637                                  >::type = __nat()) _NOEXCEPT
2638            : __ptr_(__p.release())
2639            {
2640            }
2641
2642        _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT
2643            {
2644                reset(__u.release());
2645                __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2646                return *this;
2647            }
2648
2649        template <class _Up, class _Ep>
2650            _LIBCPP_INLINE_VISIBILITY
2651            typename enable_if
2652            <
2653                !is_array<_Up>::value &&
2654                is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value &&
2655                is_assignable<deleter_type&, _Ep&&>::value,
2656                unique_ptr&
2657            >::type
2658            operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2659            {
2660                reset(__u.release());
2661                __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2662                return *this;
2663            }
2664#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2665
2666    _LIBCPP_INLINE_VISIBILITY operator __rv<unique_ptr>()
2667    {
2668        return __rv<unique_ptr>(*this);
2669    }
2670
2671    _LIBCPP_INLINE_VISIBILITY unique_ptr(__rv<unique_ptr> __u)
2672        : __ptr_(__u->release(), _VSTD::forward<deleter_type>(__u->get_deleter())) {}
2673
2674    template <class _Up, class _Ep>
2675    _LIBCPP_INLINE_VISIBILITY
2676    typename enable_if<
2677        !is_array<_Up>::value &&
2678        is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value &&
2679        is_assignable<deleter_type&, _Ep&>::value,
2680        unique_ptr&
2681    >::type
2682    operator=(unique_ptr<_Up, _Ep> __u)
2683    {
2684        reset(__u.release());
2685        __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2686        return *this;
2687    }
2688
2689    _LIBCPP_INLINE_VISIBILITY unique_ptr(pointer __p, deleter_type __d)
2690        : __ptr_(_VSTD::move(__p), _VSTD::move(__d)) {}
2691
2692    template <class _Up>
2693        _LIBCPP_INLINE_VISIBILITY
2694                typename enable_if<
2695                                      is_convertible<_Up*, _Tp*>::value &&
2696                                      is_same<_Dp, default_delete<_Tp> >::value,
2697                                      unique_ptr&
2698                                  >::type
2699        operator=(auto_ptr<_Up> __p)
2700            {reset(__p.release()); return *this;}
2701
2702#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2703    _LIBCPP_INLINE_VISIBILITY ~unique_ptr() {reset();}
2704
2705    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(nullptr_t) _NOEXCEPT
2706    {
2707        reset();
2708        return *this;
2709    }
2710
2711    _LIBCPP_INLINE_VISIBILITY typename add_lvalue_reference<_Tp>::type operator*() const
2712        {return *__ptr_.first();}
2713    _LIBCPP_INLINE_VISIBILITY pointer operator->() const _NOEXCEPT {return __ptr_.first();}
2714    _LIBCPP_INLINE_VISIBILITY pointer get() const _NOEXCEPT {return __ptr_.first();}
2715    _LIBCPP_INLINE_VISIBILITY       _Dp_reference get_deleter() _NOEXCEPT
2716        {return __ptr_.second();}
2717    _LIBCPP_INLINE_VISIBILITY _Dp_const_reference get_deleter() const _NOEXCEPT
2718        {return __ptr_.second();}
2719    _LIBCPP_INLINE_VISIBILITY
2720        _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT
2721        {return __ptr_.first() != nullptr;}
2722
2723    _LIBCPP_INLINE_VISIBILITY pointer release() _NOEXCEPT
2724    {
2725        pointer __t = __ptr_.first();
2726        __ptr_.first() = pointer();
2727        return __t;
2728    }
2729
2730    _LIBCPP_INLINE_VISIBILITY void reset(pointer __p = pointer()) _NOEXCEPT
2731    {
2732        pointer __tmp = __ptr_.first();
2733        __ptr_.first() = __p;
2734        if (__tmp)
2735            __ptr_.second()(__tmp);
2736    }
2737
2738    _LIBCPP_INLINE_VISIBILITY void swap(unique_ptr& __u) _NOEXCEPT
2739        {__ptr_.swap(__u.__ptr_);}
2740};
2741
2742template <class _Tp, class _Dp>
2743class _LIBCPP_TYPE_VIS_ONLY unique_ptr<_Tp[], _Dp>
2744{
2745public:
2746    typedef _Tp element_type;
2747    typedef _Dp deleter_type;
2748    typedef typename __pointer_type<_Tp, deleter_type>::type pointer;
2749private:
2750    __compressed_pair<pointer, deleter_type> __ptr_;
2751
2752#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2753    unique_ptr(unique_ptr&);
2754    template <class _Up>
2755        unique_ptr(unique_ptr<_Up>&);
2756    unique_ptr& operator=(unique_ptr&);
2757    template <class _Up>
2758        unique_ptr& operator=(unique_ptr<_Up>&);
2759#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2760
2761    struct __nat {int __for_bool_;};
2762
2763    typedef       typename remove_reference<deleter_type>::type& _Dp_reference;
2764    typedef const typename remove_reference<deleter_type>::type& _Dp_const_reference;
2765public:
2766    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unique_ptr() _NOEXCEPT
2767        : __ptr_(pointer())
2768        {
2769            static_assert(!is_pointer<deleter_type>::value,
2770                "unique_ptr constructed with null function pointer deleter");
2771        }
2772    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR unique_ptr(nullptr_t) _NOEXCEPT
2773        : __ptr_(pointer())
2774        {
2775            static_assert(!is_pointer<deleter_type>::value,
2776                "unique_ptr constructed with null function pointer deleter");
2777        }
2778#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2779    template <class _Pp>
2780    _LIBCPP_INLINE_VISIBILITY explicit unique_ptr(_Pp __p,
2781            typename enable_if<__same_or_less_cv_qualified<_Pp, pointer>::value, __nat>::type = __nat()) _NOEXCEPT
2782        : __ptr_(__p)
2783        {
2784            static_assert(!is_pointer<deleter_type>::value,
2785                "unique_ptr constructed with null function pointer deleter");
2786        }
2787
2788    template <class _Pp>
2789    _LIBCPP_INLINE_VISIBILITY unique_ptr(_Pp __p, typename conditional<
2790                                       is_reference<deleter_type>::value,
2791                                       deleter_type,
2792                                       typename add_lvalue_reference<const deleter_type>::type>::type __d,
2793                                       typename enable_if<__same_or_less_cv_qualified<_Pp, pointer>::value, __nat>::type = __nat())
2794             _NOEXCEPT
2795        : __ptr_(__p, __d) {}
2796
2797    _LIBCPP_INLINE_VISIBILITY unique_ptr(nullptr_t, typename conditional<
2798                                       is_reference<deleter_type>::value,
2799                                       deleter_type,
2800                                       typename add_lvalue_reference<const deleter_type>::type>::type __d)
2801             _NOEXCEPT
2802        : __ptr_(pointer(), __d) {}
2803
2804    template <class _Pp>
2805    _LIBCPP_INLINE_VISIBILITY unique_ptr(_Pp __p,
2806                                         typename remove_reference<deleter_type>::type&& __d,
2807                                         typename enable_if<__same_or_less_cv_qualified<_Pp, pointer>::value, __nat>::type = __nat())
2808             _NOEXCEPT
2809        : __ptr_(__p, _VSTD::move(__d))
2810        {
2811            static_assert(!is_reference<deleter_type>::value, "rvalue deleter bound to reference");
2812        }
2813
2814    _LIBCPP_INLINE_VISIBILITY unique_ptr(nullptr_t, typename remove_reference<deleter_type>::type&& __d)
2815             _NOEXCEPT
2816        : __ptr_(pointer(), _VSTD::move(__d))
2817        {
2818            static_assert(!is_reference<deleter_type>::value, "rvalue deleter bound to reference");
2819        }
2820
2821    _LIBCPP_INLINE_VISIBILITY unique_ptr(unique_ptr&& __u) _NOEXCEPT
2822        : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {}
2823
2824    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(unique_ptr&& __u) _NOEXCEPT
2825        {
2826            reset(__u.release());
2827            __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
2828            return *this;
2829        }
2830
2831    template <class _Up, class _Ep>
2832        _LIBCPP_INLINE_VISIBILITY
2833        unique_ptr(unique_ptr<_Up, _Ep>&& __u,
2834                   typename enable_if
2835                            <
2836                                is_array<_Up>::value &&
2837                                __same_or_less_cv_qualified<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value
2838                                && is_convertible<_Ep, deleter_type>::value &&
2839                                (
2840                                    !is_reference<deleter_type>::value ||
2841                                    is_same<deleter_type, _Ep>::value
2842                                ),
2843                                __nat
2844                            >::type = __nat()
2845                  ) _NOEXCEPT
2846        : __ptr_(__u.release(), _VSTD::forward<deleter_type>(__u.get_deleter())) {}
2847
2848
2849        template <class _Up, class _Ep>
2850            _LIBCPP_INLINE_VISIBILITY
2851            typename enable_if
2852            <
2853                is_array<_Up>::value &&
2854                __same_or_less_cv_qualified<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value &&
2855                is_assignable<deleter_type&, _Ep&&>::value,
2856                unique_ptr&
2857            >::type
2858            operator=(unique_ptr<_Up, _Ep>&& __u) _NOEXCEPT
2859            {
2860                reset(__u.release());
2861                __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
2862                return *this;
2863            }
2864#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2865
2866    _LIBCPP_INLINE_VISIBILITY explicit unique_ptr(pointer __p)
2867        : __ptr_(__p)
2868        {
2869            static_assert(!is_pointer<deleter_type>::value,
2870                "unique_ptr constructed with null function pointer deleter");
2871        }
2872
2873    _LIBCPP_INLINE_VISIBILITY unique_ptr(pointer __p, deleter_type __d)
2874        : __ptr_(__p, _VSTD::forward<deleter_type>(__d)) {}
2875
2876    _LIBCPP_INLINE_VISIBILITY unique_ptr(nullptr_t, deleter_type __d)
2877        : __ptr_(pointer(), _VSTD::forward<deleter_type>(__d)) {}
2878
2879    _LIBCPP_INLINE_VISIBILITY operator __rv<unique_ptr>()
2880    {
2881        return __rv<unique_ptr>(*this);
2882    }
2883
2884    _LIBCPP_INLINE_VISIBILITY unique_ptr(__rv<unique_ptr> __u)
2885        : __ptr_(__u->release(), _VSTD::forward<deleter_type>(__u->get_deleter())) {}
2886
2887    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(__rv<unique_ptr> __u)
2888    {
2889        reset(__u->release());
2890        __ptr_.second() = _VSTD::forward<deleter_type>(__u->get_deleter());
2891        return *this;
2892    }
2893
2894#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2895    _LIBCPP_INLINE_VISIBILITY ~unique_ptr() {reset();}
2896
2897    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(nullptr_t) _NOEXCEPT
2898    {
2899        reset();
2900        return *this;
2901    }
2902
2903    _LIBCPP_INLINE_VISIBILITY typename add_lvalue_reference<_Tp>::type operator[](size_t __i) const
2904        {return __ptr_.first()[__i];}
2905    _LIBCPP_INLINE_VISIBILITY pointer get() const _NOEXCEPT {return __ptr_.first();}
2906    _LIBCPP_INLINE_VISIBILITY       _Dp_reference get_deleter() _NOEXCEPT
2907        {return __ptr_.second();}
2908    _LIBCPP_INLINE_VISIBILITY _Dp_const_reference get_deleter() const _NOEXCEPT
2909        {return __ptr_.second();}
2910    _LIBCPP_INLINE_VISIBILITY
2911        _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT
2912        {return __ptr_.first() != nullptr;}
2913
2914    _LIBCPP_INLINE_VISIBILITY pointer release() _NOEXCEPT
2915    {
2916        pointer __t = __ptr_.first();
2917        __ptr_.first() = pointer();
2918        return __t;
2919    }
2920
2921#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2922    template <class _Pp>
2923    _LIBCPP_INLINE_VISIBILITY
2924    typename enable_if<__same_or_less_cv_qualified<_Pp, pointer>::value, void>::type
2925    reset(_Pp __p) _NOEXCEPT
2926    {
2927        pointer __tmp = __ptr_.first();
2928        __ptr_.first() = __p;
2929        if (__tmp)
2930            __ptr_.second()(__tmp);
2931    }
2932    _LIBCPP_INLINE_VISIBILITY void reset(nullptr_t) _NOEXCEPT
2933    {
2934        pointer __tmp = __ptr_.first();
2935        __ptr_.first() = nullptr;
2936        if (__tmp)
2937            __ptr_.second()(__tmp);
2938    }
2939    _LIBCPP_INLINE_VISIBILITY void reset() _NOEXCEPT
2940    {
2941        pointer __tmp = __ptr_.first();
2942        __ptr_.first() = nullptr;
2943        if (__tmp)
2944            __ptr_.second()(__tmp);
2945    }
2946#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2947    _LIBCPP_INLINE_VISIBILITY void reset(pointer __p = pointer())
2948    {
2949        pointer __tmp = __ptr_.first();
2950        __ptr_.first() = __p;
2951        if (__tmp)
2952            __ptr_.second()(__tmp);
2953    }
2954#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2955
2956    _LIBCPP_INLINE_VISIBILITY void swap(unique_ptr& __u) {__ptr_.swap(__u.__ptr_);}
2957private:
2958
2959#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
2960    template <class _Up>
2961        explicit unique_ptr(_Up);
2962    template <class _Up>
2963        unique_ptr(_Up __u,
2964                   typename conditional<
2965                                       is_reference<deleter_type>::value,
2966                                       deleter_type,
2967                                       typename add_lvalue_reference<const deleter_type>::type>::type,
2968                   typename enable_if
2969                      <
2970                         is_convertible<_Up, pointer>::value,
2971                         __nat
2972                      >::type = __nat());
2973#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
2974};
2975
2976template <class _Tp, class _Dp>
2977inline _LIBCPP_INLINE_VISIBILITY
2978void
2979swap(unique_ptr<_Tp, _Dp>& __x, unique_ptr<_Tp, _Dp>& __y) _NOEXCEPT {__x.swap(__y);}
2980
2981template <class _T1, class _D1, class _T2, class _D2>
2982inline _LIBCPP_INLINE_VISIBILITY
2983bool
2984operator==(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __x.get() == __y.get();}
2985
2986template <class _T1, class _D1, class _T2, class _D2>
2987inline _LIBCPP_INLINE_VISIBILITY
2988bool
2989operator!=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x == __y);}
2990
2991template <class _T1, class _D1, class _T2, class _D2>
2992inline _LIBCPP_INLINE_VISIBILITY
2993bool
2994operator< (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y)
2995{
2996    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
2997    typedef typename unique_ptr<_T2, _D2>::pointer _P2;
2998    typedef typename common_type<_P1, _P2>::type _Vp;
2999    return less<_Vp>()(__x.get(), __y.get());
3000}
3001
3002template <class _T1, class _D1, class _T2, class _D2>
3003inline _LIBCPP_INLINE_VISIBILITY
3004bool
3005operator> (const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return __y < __x;}
3006
3007template <class _T1, class _D1, class _T2, class _D2>
3008inline _LIBCPP_INLINE_VISIBILITY
3009bool
3010operator<=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__y < __x);}
3011
3012template <class _T1, class _D1, class _T2, class _D2>
3013inline _LIBCPP_INLINE_VISIBILITY
3014bool
3015operator>=(const unique_ptr<_T1, _D1>& __x, const unique_ptr<_T2, _D2>& __y) {return !(__x < __y);}
3016
3017template <class _T1, class _D1>
3018inline _LIBCPP_INLINE_VISIBILITY
3019bool
3020operator==(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
3021{
3022    return !__x;
3023}
3024
3025template <class _T1, class _D1>
3026inline _LIBCPP_INLINE_VISIBILITY
3027bool
3028operator==(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
3029{
3030    return !__x;
3031}
3032
3033template <class _T1, class _D1>
3034inline _LIBCPP_INLINE_VISIBILITY
3035bool
3036operator!=(const unique_ptr<_T1, _D1>& __x, nullptr_t) _NOEXCEPT
3037{
3038    return static_cast<bool>(__x);
3039}
3040
3041template <class _T1, class _D1>
3042inline _LIBCPP_INLINE_VISIBILITY
3043bool
3044operator!=(nullptr_t, const unique_ptr<_T1, _D1>& __x) _NOEXCEPT
3045{
3046    return static_cast<bool>(__x);
3047}
3048
3049template <class _T1, class _D1>
3050inline _LIBCPP_INLINE_VISIBILITY
3051bool
3052operator<(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3053{
3054    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
3055    return less<_P1>()(__x.get(), nullptr);
3056}
3057
3058template <class _T1, class _D1>
3059inline _LIBCPP_INLINE_VISIBILITY
3060bool
3061operator<(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3062{
3063    typedef typename unique_ptr<_T1, _D1>::pointer _P1;
3064    return less<_P1>()(nullptr, __x.get());
3065}
3066
3067template <class _T1, class _D1>
3068inline _LIBCPP_INLINE_VISIBILITY
3069bool
3070operator>(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3071{
3072    return nullptr < __x;
3073}
3074
3075template <class _T1, class _D1>
3076inline _LIBCPP_INLINE_VISIBILITY
3077bool
3078operator>(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3079{
3080    return __x < nullptr;
3081}
3082
3083template <class _T1, class _D1>
3084inline _LIBCPP_INLINE_VISIBILITY
3085bool
3086operator<=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3087{
3088    return !(nullptr < __x);
3089}
3090
3091template <class _T1, class _D1>
3092inline _LIBCPP_INLINE_VISIBILITY
3093bool
3094operator<=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3095{
3096    return !(__x < nullptr);
3097}
3098
3099template <class _T1, class _D1>
3100inline _LIBCPP_INLINE_VISIBILITY
3101bool
3102operator>=(const unique_ptr<_T1, _D1>& __x, nullptr_t)
3103{
3104    return !(__x < nullptr);
3105}
3106
3107template <class _T1, class _D1>
3108inline _LIBCPP_INLINE_VISIBILITY
3109bool
3110operator>=(nullptr_t, const unique_ptr<_T1, _D1>& __x)
3111{
3112    return !(nullptr < __x);
3113}
3114
3115#ifdef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3116
3117template <class _Tp, class _Dp>
3118inline _LIBCPP_INLINE_VISIBILITY
3119unique_ptr<_Tp, _Dp>
3120move(unique_ptr<_Tp, _Dp>& __t)
3121{
3122    return unique_ptr<_Tp, _Dp>(__rv<unique_ptr<_Tp, _Dp> >(__t));
3123}
3124
3125#endif
3126
3127#if _LIBCPP_STD_VER > 11
3128
3129template<class _Tp>
3130struct __unique_if
3131{
3132    typedef unique_ptr<_Tp> __unique_single;
3133};
3134
3135template<class _Tp>
3136struct __unique_if<_Tp[]>
3137{
3138    typedef unique_ptr<_Tp[]> __unique_array_unknown_bound;
3139};
3140
3141template<class _Tp, size_t _Np>
3142struct __unique_if<_Tp[_Np]>
3143{
3144    typedef void __unique_array_known_bound;
3145};
3146
3147template<class _Tp, class... _Args>
3148inline _LIBCPP_INLINE_VISIBILITY
3149typename __unique_if<_Tp>::__unique_single
3150make_unique(_Args&&... __args)
3151{
3152    return unique_ptr<_Tp>(new _Tp(_VSTD::forward<_Args>(__args)...));
3153}
3154
3155template<class _Tp>
3156inline _LIBCPP_INLINE_VISIBILITY
3157typename __unique_if<_Tp>::__unique_array_unknown_bound
3158make_unique(size_t __n)
3159{
3160    typedef typename remove_extent<_Tp>::type _Up;
3161    return unique_ptr<_Tp>(new _Up[__n]());
3162}
3163
3164template<class _Tp, class... _Args>
3165    typename __unique_if<_Tp>::__unique_array_known_bound
3166    make_unique(_Args&&...) = delete;
3167
3168#endif  // _LIBCPP_STD_VER > 11
3169
3170template <class _Tp> struct hash;
3171
3172template <class _Size>
3173inline _LIBCPP_INLINE_VISIBILITY
3174_Size
3175__loadword(const void* __p)
3176{
3177    _Size __r;
3178    std::memcpy(&__r, __p, sizeof(__r));
3179    return __r;
3180}
3181
3182// We use murmur2 when size_t is 32 bits, and cityhash64 when size_t
3183// is 64 bits.  This is because cityhash64 uses 64bit x 64bit
3184// multiplication, which can be very slow on 32-bit systems.
3185template <class _Size, size_t = sizeof(_Size)*__CHAR_BIT__>
3186struct __murmur2_or_cityhash;
3187
3188template <class _Size>
3189struct __murmur2_or_cityhash<_Size, 32>
3190{
3191    _Size operator()(const void* __key, _Size __len);
3192};
3193
3194// murmur2
3195template <class _Size>
3196_Size
3197__murmur2_or_cityhash<_Size, 32>::operator()(const void* __key, _Size __len)
3198{
3199    const _Size __m = 0x5bd1e995;
3200    const _Size __r = 24;
3201    _Size __h = __len;
3202    const unsigned char* __data = static_cast<const unsigned char*>(__key);
3203    for (; __len >= 4; __data += 4, __len -= 4)
3204    {
3205        _Size __k = __loadword<_Size>(__data);
3206        __k *= __m;
3207        __k ^= __k >> __r;
3208        __k *= __m;
3209        __h *= __m;
3210        __h ^= __k;
3211    }
3212    switch (__len)
3213    {
3214    case 3:
3215        __h ^= __data[2] << 16;
3216    case 2:
3217        __h ^= __data[1] << 8;
3218    case 1:
3219        __h ^= __data[0];
3220        __h *= __m;
3221    }
3222    __h ^= __h >> 13;
3223    __h *= __m;
3224    __h ^= __h >> 15;
3225    return __h;
3226}
3227
3228template <class _Size>
3229struct __murmur2_or_cityhash<_Size, 64>
3230{
3231    _Size operator()(const void* __key, _Size __len);
3232
3233 private:
3234  // Some primes between 2^63 and 2^64.
3235  static const _Size __k0 = 0xc3a5c85c97cb3127ULL;
3236  static const _Size __k1 = 0xb492b66fbe98f273ULL;
3237  static const _Size __k2 = 0x9ae16a3b2f90404fULL;
3238  static const _Size __k3 = 0xc949d7c7509e6557ULL;
3239
3240  static _Size __rotate(_Size __val, int __shift) {
3241    return __shift == 0 ? __val : ((__val >> __shift) | (__val << (64 - __shift)));
3242  }
3243
3244  static _Size __rotate_by_at_least_1(_Size __val, int __shift) {
3245    return (__val >> __shift) | (__val << (64 - __shift));
3246  }
3247
3248  static _Size __shift_mix(_Size __val) {
3249    return __val ^ (__val >> 47);
3250  }
3251
3252  static _Size __hash_len_16(_Size __u, _Size __v) {
3253    const _Size __mul = 0x9ddfea08eb382d69ULL;
3254    _Size __a = (__u ^ __v) * __mul;
3255    __a ^= (__a >> 47);
3256    _Size __b = (__v ^ __a) * __mul;
3257    __b ^= (__b >> 47);
3258    __b *= __mul;
3259    return __b;
3260  }
3261
3262  static _Size __hash_len_0_to_16(const char* __s, _Size __len) {
3263    if (__len > 8) {
3264      const _Size __a = __loadword<_Size>(__s);
3265      const _Size __b = __loadword<_Size>(__s + __len - 8);
3266      return __hash_len_16(__a, __rotate_by_at_least_1(__b + __len, __len)) ^ __b;
3267    }
3268    if (__len >= 4) {
3269      const uint32_t __a = __loadword<uint32_t>(__s);
3270      const uint32_t __b = __loadword<uint32_t>(__s + __len - 4);
3271      return __hash_len_16(__len + (__a << 3), __b);
3272    }
3273    if (__len > 0) {
3274      const unsigned char __a = __s[0];
3275      const unsigned char __b = __s[__len >> 1];
3276      const unsigned char __c = __s[__len - 1];
3277      const uint32_t __y = static_cast<uint32_t>(__a) +
3278                           (static_cast<uint32_t>(__b) << 8);
3279      const uint32_t __z = __len + (static_cast<uint32_t>(__c) << 2);
3280      return __shift_mix(__y * __k2 ^ __z * __k3) * __k2;
3281    }
3282    return __k2;
3283  }
3284
3285  static _Size __hash_len_17_to_32(const char *__s, _Size __len) {
3286    const _Size __a = __loadword<_Size>(__s) * __k1;
3287    const _Size __b = __loadword<_Size>(__s + 8);
3288    const _Size __c = __loadword<_Size>(__s + __len - 8) * __k2;
3289    const _Size __d = __loadword<_Size>(__s + __len - 16) * __k0;
3290    return __hash_len_16(__rotate(__a - __b, 43) + __rotate(__c, 30) + __d,
3291                         __a + __rotate(__b ^ __k3, 20) - __c + __len);
3292  }
3293
3294  // Return a 16-byte hash for 48 bytes.  Quick and dirty.
3295  // Callers do best to use "random-looking" values for a and b.
3296  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
3297      _Size __w, _Size __x, _Size __y, _Size __z, _Size __a, _Size __b) {
3298    __a += __w;
3299    __b = __rotate(__b + __a + __z, 21);
3300    const _Size __c = __a;
3301    __a += __x;
3302    __a += __y;
3303    __b += __rotate(__a, 44);
3304    return pair<_Size, _Size>(__a + __z, __b + __c);
3305  }
3306
3307  // Return a 16-byte hash for s[0] ... s[31], a, and b.  Quick and dirty.
3308  static pair<_Size, _Size> __weak_hash_len_32_with_seeds(
3309      const char* __s, _Size __a, _Size __b) {
3310    return __weak_hash_len_32_with_seeds(__loadword<_Size>(__s),
3311                                         __loadword<_Size>(__s + 8),
3312                                         __loadword<_Size>(__s + 16),
3313                                         __loadword<_Size>(__s + 24),
3314                                         __a,
3315                                         __b);
3316  }
3317
3318  // Return an 8-byte hash for 33 to 64 bytes.
3319  static _Size __hash_len_33_to_64(const char *__s, size_t __len) {
3320    _Size __z = __loadword<_Size>(__s + 24);
3321    _Size __a = __loadword<_Size>(__s) +
3322                (__len + __loadword<_Size>(__s + __len - 16)) * __k0;
3323    _Size __b = __rotate(__a + __z, 52);
3324    _Size __c = __rotate(__a, 37);
3325    __a += __loadword<_Size>(__s + 8);
3326    __c += __rotate(__a, 7);
3327    __a += __loadword<_Size>(__s + 16);
3328    _Size __vf = __a + __z;
3329    _Size __vs = __b + __rotate(__a, 31) + __c;
3330    __a = __loadword<_Size>(__s + 16) + __loadword<_Size>(__s + __len - 32);
3331    __z += __loadword<_Size>(__s + __len - 8);
3332    __b = __rotate(__a + __z, 52);
3333    __c = __rotate(__a, 37);
3334    __a += __loadword<_Size>(__s + __len - 24);
3335    __c += __rotate(__a, 7);
3336    __a += __loadword<_Size>(__s + __len - 16);
3337    _Size __wf = __a + __z;
3338    _Size __ws = __b + __rotate(__a, 31) + __c;
3339    _Size __r = __shift_mix((__vf + __ws) * __k2 + (__wf + __vs) * __k0);
3340    return __shift_mix(__r * __k0 + __vs) * __k2;
3341  }
3342};
3343
3344// cityhash64
3345template <class _Size>
3346_Size
3347__murmur2_or_cityhash<_Size, 64>::operator()(const void* __key, _Size __len)
3348{
3349  const char* __s = static_cast<const char*>(__key);
3350  if (__len <= 32) {
3351    if (__len <= 16) {
3352      return __hash_len_0_to_16(__s, __len);
3353    } else {
3354      return __hash_len_17_to_32(__s, __len);
3355    }
3356  } else if (__len <= 64) {
3357    return __hash_len_33_to_64(__s, __len);
3358  }
3359
3360  // For strings over 64 bytes we hash the end first, and then as we
3361  // loop we keep 56 bytes of state: v, w, x, y, and z.
3362  _Size __x = __loadword<_Size>(__s + __len - 40);
3363  _Size __y = __loadword<_Size>(__s + __len - 16) +
3364              __loadword<_Size>(__s + __len - 56);
3365  _Size __z = __hash_len_16(__loadword<_Size>(__s + __len - 48) + __len,
3366                          __loadword<_Size>(__s + __len - 24));
3367  pair<_Size, _Size> __v = __weak_hash_len_32_with_seeds(__s + __len - 64, __len, __z);
3368  pair<_Size, _Size> __w = __weak_hash_len_32_with_seeds(__s + __len - 32, __y + __k1, __x);
3369  __x = __x * __k1 + __loadword<_Size>(__s);
3370
3371  // Decrease len to the nearest multiple of 64, and operate on 64-byte chunks.
3372  __len = (__len - 1) & ~static_cast<_Size>(63);
3373  do {
3374    __x = __rotate(__x + __y + __v.first + __loadword<_Size>(__s + 8), 37) * __k1;
3375    __y = __rotate(__y + __v.second + __loadword<_Size>(__s + 48), 42) * __k1;
3376    __x ^= __w.second;
3377    __y += __v.first + __loadword<_Size>(__s + 40);
3378    __z = __rotate(__z + __w.first, 33) * __k1;
3379    __v = __weak_hash_len_32_with_seeds(__s, __v.second * __k1, __x + __w.first);
3380    __w = __weak_hash_len_32_with_seeds(__s + 32, __z + __w.second,
3381                                        __y + __loadword<_Size>(__s + 16));
3382    std::swap(__z, __x);
3383    __s += 64;
3384    __len -= 64;
3385  } while (__len != 0);
3386  return __hash_len_16(
3387      __hash_len_16(__v.first, __w.first) + __shift_mix(__y) * __k1 + __z,
3388      __hash_len_16(__v.second, __w.second) + __x);
3389}
3390
3391template <class _Tp, size_t = sizeof(_Tp) / sizeof(size_t)>
3392struct __scalar_hash;
3393
3394template <class _Tp>
3395struct __scalar_hash<_Tp, 0>
3396    : public unary_function<_Tp, size_t>
3397{
3398    _LIBCPP_INLINE_VISIBILITY
3399    size_t operator()(_Tp __v) const _NOEXCEPT
3400    {
3401        union
3402        {
3403            _Tp    __t;
3404            size_t __a;
3405        } __u;
3406        __u.__a = 0;
3407        __u.__t = __v;
3408        return __u.__a;
3409    }
3410};
3411
3412template <class _Tp>
3413struct __scalar_hash<_Tp, 1>
3414    : public unary_function<_Tp, size_t>
3415{
3416    _LIBCPP_INLINE_VISIBILITY
3417    size_t operator()(_Tp __v) const _NOEXCEPT
3418    {
3419        union
3420        {
3421            _Tp    __t;
3422            size_t __a;
3423        } __u;
3424        __u.__t = __v;
3425        return __u.__a;
3426    }
3427};
3428
3429template <class _Tp>
3430struct __scalar_hash<_Tp, 2>
3431    : public unary_function<_Tp, size_t>
3432{
3433    _LIBCPP_INLINE_VISIBILITY
3434    size_t operator()(_Tp __v) const _NOEXCEPT
3435    {
3436        union
3437        {
3438            _Tp __t;
3439            struct
3440            {
3441                size_t __a;
3442                size_t __b;
3443            } __s;
3444        } __u;
3445        __u.__t = __v;
3446        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
3447    }
3448};
3449
3450template <class _Tp>
3451struct __scalar_hash<_Tp, 3>
3452    : public unary_function<_Tp, size_t>
3453{
3454    _LIBCPP_INLINE_VISIBILITY
3455    size_t operator()(_Tp __v) const _NOEXCEPT
3456    {
3457        union
3458        {
3459            _Tp __t;
3460            struct
3461            {
3462                size_t __a;
3463                size_t __b;
3464                size_t __c;
3465            } __s;
3466        } __u;
3467        __u.__t = __v;
3468        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
3469    }
3470};
3471
3472template <class _Tp>
3473struct __scalar_hash<_Tp, 4>
3474    : public unary_function<_Tp, size_t>
3475{
3476    _LIBCPP_INLINE_VISIBILITY
3477    size_t operator()(_Tp __v) const _NOEXCEPT
3478    {
3479        union
3480        {
3481            _Tp __t;
3482            struct
3483            {
3484                size_t __a;
3485                size_t __b;
3486                size_t __c;
3487                size_t __d;
3488            } __s;
3489        } __u;
3490        __u.__t = __v;
3491        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
3492    }
3493};
3494
3495template<class _Tp>
3496struct _LIBCPP_TYPE_VIS_ONLY hash<_Tp*>
3497    : public unary_function<_Tp*, size_t>
3498{
3499    _LIBCPP_INLINE_VISIBILITY
3500    size_t operator()(_Tp* __v) const _NOEXCEPT
3501    {
3502        union
3503        {
3504            _Tp* __t;
3505            size_t __a;
3506        } __u;
3507        __u.__t = __v;
3508        return __murmur2_or_cityhash<size_t>()(&__u, sizeof(__u));
3509    }
3510};
3511
3512template <class _Tp, class _Dp>
3513struct _LIBCPP_TYPE_VIS_ONLY hash<unique_ptr<_Tp, _Dp> >
3514{
3515    typedef unique_ptr<_Tp, _Dp> argument_type;
3516    typedef size_t               result_type;
3517    _LIBCPP_INLINE_VISIBILITY
3518    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
3519    {
3520        typedef typename argument_type::pointer pointer;
3521        return hash<pointer>()(__ptr.get());
3522    }
3523};
3524
3525struct __destruct_n
3526{
3527private:
3528    size_t size;
3529
3530    template <class _Tp>
3531    _LIBCPP_INLINE_VISIBILITY void __process(_Tp* __p, false_type) _NOEXCEPT
3532        {for (size_t __i = 0; __i < size; ++__i, ++__p) __p->~_Tp();}
3533
3534    template <class _Tp>
3535    _LIBCPP_INLINE_VISIBILITY void __process(_Tp*, true_type) _NOEXCEPT
3536        {}
3537
3538    _LIBCPP_INLINE_VISIBILITY void __incr(false_type) _NOEXCEPT
3539        {++size;}
3540    _LIBCPP_INLINE_VISIBILITY void __incr(true_type) _NOEXCEPT
3541        {}
3542
3543    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, false_type) _NOEXCEPT
3544        {size = __s;}
3545    _LIBCPP_INLINE_VISIBILITY void __set(size_t, true_type) _NOEXCEPT
3546        {}
3547public:
3548    _LIBCPP_INLINE_VISIBILITY explicit __destruct_n(size_t __s) _NOEXCEPT
3549        : size(__s) {}
3550
3551    template <class _Tp>
3552    _LIBCPP_INLINE_VISIBILITY void __incr(_Tp*) _NOEXCEPT
3553        {__incr(integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3554
3555    template <class _Tp>
3556    _LIBCPP_INLINE_VISIBILITY void __set(size_t __s, _Tp*) _NOEXCEPT
3557        {__set(__s, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3558
3559    template <class _Tp>
3560    _LIBCPP_INLINE_VISIBILITY void operator()(_Tp* __p) _NOEXCEPT
3561        {__process(__p, integral_constant<bool, is_trivially_destructible<_Tp>::value>());}
3562};
3563
3564template <class _Alloc>
3565class __allocator_destructor
3566{
3567    typedef allocator_traits<_Alloc> __alloc_traits;
3568public:
3569    typedef typename __alloc_traits::pointer pointer;
3570    typedef typename __alloc_traits::size_type size_type;
3571private:
3572    _Alloc& __alloc_;
3573    size_type __s_;
3574public:
3575    _LIBCPP_INLINE_VISIBILITY __allocator_destructor(_Alloc& __a, size_type __s)
3576             _NOEXCEPT
3577        : __alloc_(__a), __s_(__s) {}
3578    _LIBCPP_INLINE_VISIBILITY
3579    void operator()(pointer __p) _NOEXCEPT
3580        {__alloc_traits::deallocate(__alloc_, __p, __s_);}
3581};
3582
3583template <class _InputIterator, class _ForwardIterator>
3584_ForwardIterator
3585uninitialized_copy(_InputIterator __f, _InputIterator __l, _ForwardIterator __r)
3586{
3587    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3588#ifndef _LIBCPP_NO_EXCEPTIONS
3589    _ForwardIterator __s = __r;
3590    try
3591    {
3592#endif
3593        for (; __f != __l; ++__f, (void) ++__r)
3594            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3595#ifndef _LIBCPP_NO_EXCEPTIONS
3596    }
3597    catch (...)
3598    {
3599        for (; __s != __r; ++__s)
3600            __s->~value_type();
3601        throw;
3602    }
3603#endif
3604    return __r;
3605}
3606
3607template <class _InputIterator, class _Size, class _ForwardIterator>
3608_ForwardIterator
3609uninitialized_copy_n(_InputIterator __f, _Size __n, _ForwardIterator __r)
3610{
3611    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3612#ifndef _LIBCPP_NO_EXCEPTIONS
3613    _ForwardIterator __s = __r;
3614    try
3615    {
3616#endif
3617        for (; __n > 0; ++__f, (void) ++__r, (void) --__n)
3618            ::new (static_cast<void*>(_VSTD::addressof(*__r))) value_type(*__f);
3619#ifndef _LIBCPP_NO_EXCEPTIONS
3620    }
3621    catch (...)
3622    {
3623        for (; __s != __r; ++__s)
3624            __s->~value_type();
3625        throw;
3626    }
3627#endif
3628    return __r;
3629}
3630
3631template <class _ForwardIterator, class _Tp>
3632void
3633uninitialized_fill(_ForwardIterator __f, _ForwardIterator __l, const _Tp& __x)
3634{
3635    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3636#ifndef _LIBCPP_NO_EXCEPTIONS
3637    _ForwardIterator __s = __f;
3638    try
3639    {
3640#endif
3641        for (; __f != __l; ++__f)
3642            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3643#ifndef _LIBCPP_NO_EXCEPTIONS
3644    }
3645    catch (...)
3646    {
3647        for (; __s != __f; ++__s)
3648            __s->~value_type();
3649        throw;
3650    }
3651#endif
3652}
3653
3654template <class _ForwardIterator, class _Size, class _Tp>
3655_ForwardIterator
3656uninitialized_fill_n(_ForwardIterator __f, _Size __n, const _Tp& __x)
3657{
3658    typedef typename iterator_traits<_ForwardIterator>::value_type value_type;
3659#ifndef _LIBCPP_NO_EXCEPTIONS
3660    _ForwardIterator __s = __f;
3661    try
3662    {
3663#endif
3664        for (; __n > 0; ++__f, (void) --__n)
3665            ::new (static_cast<void*>(_VSTD::addressof(*__f))) value_type(__x);
3666#ifndef _LIBCPP_NO_EXCEPTIONS
3667    }
3668    catch (...)
3669    {
3670        for (; __s != __f; ++__s)
3671            __s->~value_type();
3672        throw;
3673    }
3674#endif
3675    return __f;
3676}
3677
3678class _LIBCPP_EXCEPTION_ABI bad_weak_ptr
3679    : public std::exception
3680{
3681public:
3682    virtual ~bad_weak_ptr() _NOEXCEPT;
3683    virtual const char* what() const  _NOEXCEPT;
3684};
3685
3686template<class _Tp> class _LIBCPP_TYPE_VIS_ONLY weak_ptr;
3687
3688class _LIBCPP_TYPE_VIS __shared_count
3689{
3690    __shared_count(const __shared_count&);
3691    __shared_count& operator=(const __shared_count&);
3692
3693protected:
3694    long __shared_owners_;
3695    virtual ~__shared_count();
3696private:
3697    virtual void __on_zero_shared() _NOEXCEPT = 0;
3698
3699public:
3700    _LIBCPP_INLINE_VISIBILITY
3701    explicit __shared_count(long __refs = 0) _NOEXCEPT
3702        : __shared_owners_(__refs) {}
3703
3704    void __add_shared() _NOEXCEPT;
3705    bool __release_shared() _NOEXCEPT;
3706    _LIBCPP_INLINE_VISIBILITY
3707    long use_count() const _NOEXCEPT {
3708        return __libcpp_relaxed_load(&__shared_owners_) + 1;
3709    }
3710};
3711
3712class _LIBCPP_TYPE_VIS __shared_weak_count
3713    : private __shared_count
3714{
3715    long __shared_weak_owners_;
3716
3717public:
3718    _LIBCPP_INLINE_VISIBILITY
3719    explicit __shared_weak_count(long __refs = 0) _NOEXCEPT
3720        : __shared_count(__refs),
3721          __shared_weak_owners_(__refs) {}
3722protected:
3723    virtual ~__shared_weak_count();
3724
3725public:
3726    void __add_shared() _NOEXCEPT;
3727    void __add_weak() _NOEXCEPT;
3728    void __release_shared() _NOEXCEPT;
3729    void __release_weak() _NOEXCEPT;
3730    _LIBCPP_INLINE_VISIBILITY
3731    long use_count() const _NOEXCEPT {return __shared_count::use_count();}
3732    __shared_weak_count* lock() _NOEXCEPT;
3733
3734    // Define the function out only if we build static libc++ without RTTI.
3735    // Otherwise we may break clients who need to compile their projects with
3736    // -fno-rtti and yet link against a libc++.dylib compiled
3737    // without -fno-rtti.
3738#if !defined(_LIBCPP_NO_RTTI) || !defined(_LIBCPP_BUILD_STATIC)
3739    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3740#endif
3741private:
3742    virtual void __on_zero_shared_weak() _NOEXCEPT = 0;
3743};
3744
3745template <class _Tp, class _Dp, class _Alloc>
3746class __shared_ptr_pointer
3747    : public __shared_weak_count
3748{
3749    __compressed_pair<__compressed_pair<_Tp, _Dp>, _Alloc> __data_;
3750public:
3751    _LIBCPP_INLINE_VISIBILITY
3752    __shared_ptr_pointer(_Tp __p, _Dp __d, _Alloc __a)
3753        :  __data_(__compressed_pair<_Tp, _Dp>(__p, _VSTD::move(__d)), _VSTD::move(__a)) {}
3754
3755#ifndef _LIBCPP_NO_RTTI
3756    virtual const void* __get_deleter(const type_info&) const _NOEXCEPT;
3757#endif
3758
3759private:
3760    virtual void __on_zero_shared() _NOEXCEPT;
3761    virtual void __on_zero_shared_weak() _NOEXCEPT;
3762};
3763
3764#ifndef _LIBCPP_NO_RTTI
3765
3766template <class _Tp, class _Dp, class _Alloc>
3767const void*
3768__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__get_deleter(const type_info& __t) const _NOEXCEPT
3769{
3770    return __t == typeid(_Dp) ? _VSTD::addressof(__data_.first().second()) : 0;
3771}
3772
3773#endif  // _LIBCPP_NO_RTTI
3774
3775template <class _Tp, class _Dp, class _Alloc>
3776void
3777__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared() _NOEXCEPT
3778{
3779    __data_.first().second()(__data_.first().first());
3780    __data_.first().second().~_Dp();
3781}
3782
3783template <class _Tp, class _Dp, class _Alloc>
3784void
3785__shared_ptr_pointer<_Tp, _Dp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3786{
3787    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_pointer>::type _Al;
3788    typedef allocator_traits<_Al> _ATraits;
3789    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3790
3791    _Al __a(__data_.second());
3792    __data_.second().~_Alloc();
3793    __a.deallocate(_PTraits::pointer_to(*this), 1);
3794}
3795
3796template <class _Tp, class _Alloc>
3797class __shared_ptr_emplace
3798    : public __shared_weak_count
3799{
3800    __compressed_pair<_Alloc, _Tp> __data_;
3801public:
3802#ifndef _LIBCPP_HAS_NO_VARIADICS
3803
3804    _LIBCPP_INLINE_VISIBILITY
3805    __shared_ptr_emplace(_Alloc __a)
3806        :  __data_(_VSTD::move(__a)) {}
3807
3808    template <class ..._Args>
3809        _LIBCPP_INLINE_VISIBILITY
3810        __shared_ptr_emplace(_Alloc __a, _Args&& ...__args)
3811            :  __data_(piecewise_construct, _VSTD::forward_as_tuple(__a),
3812                   _VSTD::forward_as_tuple(_VSTD::forward<_Args>(__args)...)) {}
3813
3814#else  // _LIBCPP_HAS_NO_VARIADICS
3815
3816    _LIBCPP_INLINE_VISIBILITY
3817    __shared_ptr_emplace(_Alloc __a)
3818        :  __data_(__a) {}
3819
3820    template <class _A0>
3821        _LIBCPP_INLINE_VISIBILITY
3822        __shared_ptr_emplace(_Alloc __a, _A0& __a0)
3823            :  __data_(__a, _Tp(__a0)) {}
3824
3825    template <class _A0, class _A1>
3826        _LIBCPP_INLINE_VISIBILITY
3827        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1)
3828            :  __data_(__a, _Tp(__a0, __a1)) {}
3829
3830    template <class _A0, class _A1, class _A2>
3831        _LIBCPP_INLINE_VISIBILITY
3832        __shared_ptr_emplace(_Alloc __a, _A0& __a0, _A1& __a1, _A2& __a2)
3833            :  __data_(__a, _Tp(__a0, __a1, __a2)) {}
3834
3835#endif  // _LIBCPP_HAS_NO_VARIADICS
3836
3837private:
3838    virtual void __on_zero_shared() _NOEXCEPT;
3839    virtual void __on_zero_shared_weak() _NOEXCEPT;
3840public:
3841    _LIBCPP_INLINE_VISIBILITY
3842    _Tp* get() _NOEXCEPT {return &__data_.second();}
3843};
3844
3845template <class _Tp, class _Alloc>
3846void
3847__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared() _NOEXCEPT
3848{
3849    __data_.second().~_Tp();
3850}
3851
3852template <class _Tp, class _Alloc>
3853void
3854__shared_ptr_emplace<_Tp, _Alloc>::__on_zero_shared_weak() _NOEXCEPT
3855{
3856    typedef typename __allocator_traits_rebind<_Alloc, __shared_ptr_emplace>::type _Al;
3857    typedef allocator_traits<_Al> _ATraits;
3858    typedef pointer_traits<typename _ATraits::pointer> _PTraits;
3859    _Al __a(__data_.first());
3860    __data_.first().~_Alloc();
3861    __a.deallocate(_PTraits::pointer_to(*this), 1);
3862}
3863
3864template<class _Tp> class _LIBCPP_TYPE_VIS_ONLY enable_shared_from_this;
3865
3866template<class _Tp>
3867class _LIBCPP_TYPE_VIS_ONLY shared_ptr
3868{
3869public:
3870    typedef _Tp element_type;
3871private:
3872    element_type*      __ptr_;
3873    __shared_weak_count* __cntrl_;
3874
3875    struct __nat {int __for_bool_;};
3876public:
3877    _LIBCPP_CONSTEXPR shared_ptr() _NOEXCEPT;
3878    _LIBCPP_CONSTEXPR shared_ptr(nullptr_t) _NOEXCEPT;
3879    template<class _Yp>
3880        explicit shared_ptr(_Yp* __p,
3881                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3882    template<class _Yp, class _Dp>
3883        shared_ptr(_Yp* __p, _Dp __d,
3884                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3885    template<class _Yp, class _Dp, class _Alloc>
3886        shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
3887                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3888    template <class _Dp> shared_ptr(nullptr_t __p, _Dp __d);
3889    template <class _Dp, class _Alloc> shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a);
3890    template<class _Yp> shared_ptr(const shared_ptr<_Yp>& __r, element_type* __p) _NOEXCEPT;
3891    shared_ptr(const shared_ptr& __r) _NOEXCEPT;
3892    template<class _Yp>
3893        shared_ptr(const shared_ptr<_Yp>& __r,
3894                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type = __nat())
3895                       _NOEXCEPT;
3896#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3897    shared_ptr(shared_ptr&& __r) _NOEXCEPT;
3898    template<class _Yp> shared_ptr(shared_ptr<_Yp>&& __r,
3899                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type = __nat())
3900                       _NOEXCEPT;
3901#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3902    template<class _Yp> explicit shared_ptr(const weak_ptr<_Yp>& __r,
3903                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type= __nat());
3904#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3905    template<class _Yp>
3906        shared_ptr(auto_ptr<_Yp>&& __r,
3907                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3908#else
3909    template<class _Yp>
3910        shared_ptr(auto_ptr<_Yp> __r,
3911                   typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type = __nat());
3912#endif
3913#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3914    template <class _Yp, class _Dp>
3915        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3916                   typename enable_if
3917                   <
3918                       !is_lvalue_reference<_Dp>::value &&
3919                       !is_array<_Yp>::value &&
3920                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3921                       __nat
3922                   >::type = __nat());
3923    template <class _Yp, class _Dp>
3924        shared_ptr(unique_ptr<_Yp, _Dp>&&,
3925                   typename enable_if
3926                   <
3927                       is_lvalue_reference<_Dp>::value &&
3928                       !is_array<_Yp>::value &&
3929                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3930                       __nat
3931                   >::type = __nat());
3932#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3933    template <class _Yp, class _Dp>
3934        shared_ptr(unique_ptr<_Yp, _Dp>,
3935                   typename enable_if
3936                   <
3937                       !is_lvalue_reference<_Dp>::value &&
3938                       !is_array<_Yp>::value &&
3939                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3940                       __nat
3941                   >::type = __nat());
3942    template <class _Yp, class _Dp>
3943        shared_ptr(unique_ptr<_Yp, _Dp>,
3944                   typename enable_if
3945                   <
3946                       is_lvalue_reference<_Dp>::value &&
3947                       !is_array<_Yp>::value &&
3948                       is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3949                       __nat
3950                   >::type = __nat());
3951#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3952
3953    ~shared_ptr();
3954
3955    shared_ptr& operator=(const shared_ptr& __r) _NOEXCEPT;
3956    template<class _Yp>
3957        typename enable_if
3958        <
3959            is_convertible<_Yp*, element_type*>::value,
3960            shared_ptr&
3961        >::type
3962        operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT;
3963#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3964    shared_ptr& operator=(shared_ptr&& __r) _NOEXCEPT;
3965    template<class _Yp>
3966        typename enable_if
3967        <
3968            is_convertible<_Yp*, element_type*>::value,
3969            shared_ptr<_Tp>&
3970        >::type
3971        operator=(shared_ptr<_Yp>&& __r);
3972    template<class _Yp>
3973        typename enable_if
3974        <
3975            !is_array<_Yp>::value &&
3976            is_convertible<_Yp*, element_type*>::value,
3977            shared_ptr
3978        >::type&
3979        operator=(auto_ptr<_Yp>&& __r);
3980#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
3981    template<class _Yp>
3982        typename enable_if
3983        <
3984            !is_array<_Yp>::value &&
3985            is_convertible<_Yp*, element_type*>::value,
3986            shared_ptr&
3987        >::type
3988        operator=(auto_ptr<_Yp> __r);
3989#endif
3990    template <class _Yp, class _Dp>
3991        typename enable_if
3992        <
3993            !is_array<_Yp>::value &&
3994            is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
3995            shared_ptr&
3996        >::type
3997#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
3998        operator=(unique_ptr<_Yp, _Dp>&& __r);
3999#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4000        operator=(unique_ptr<_Yp, _Dp> __r);
4001#endif
4002
4003    void swap(shared_ptr& __r) _NOEXCEPT;
4004    void reset() _NOEXCEPT;
4005    template<class _Yp>
4006        typename enable_if
4007        <
4008            is_convertible<_Yp*, element_type*>::value,
4009            void
4010        >::type
4011        reset(_Yp* __p);
4012    template<class _Yp, class _Dp>
4013        typename enable_if
4014        <
4015            is_convertible<_Yp*, element_type*>::value,
4016            void
4017        >::type
4018        reset(_Yp* __p, _Dp __d);
4019    template<class _Yp, class _Dp, class _Alloc>
4020        typename enable_if
4021        <
4022            is_convertible<_Yp*, element_type*>::value,
4023            void
4024        >::type
4025        reset(_Yp* __p, _Dp __d, _Alloc __a);
4026
4027    _LIBCPP_INLINE_VISIBILITY
4028    element_type* get() const _NOEXCEPT {return __ptr_;}
4029    _LIBCPP_INLINE_VISIBILITY
4030    typename add_lvalue_reference<element_type>::type operator*() const _NOEXCEPT
4031        {return *__ptr_;}
4032    _LIBCPP_INLINE_VISIBILITY
4033    element_type* operator->() const _NOEXCEPT {return __ptr_;}
4034    _LIBCPP_INLINE_VISIBILITY
4035    long use_count() const _NOEXCEPT {return __cntrl_ ? __cntrl_->use_count() : 0;}
4036    _LIBCPP_INLINE_VISIBILITY
4037    bool unique() const _NOEXCEPT {return use_count() == 1;}
4038    _LIBCPP_INLINE_VISIBILITY
4039    _LIBCPP_EXPLICIT operator bool() const _NOEXCEPT {return get() != 0;}
4040    template <class _Up>
4041        _LIBCPP_INLINE_VISIBILITY
4042        bool owner_before(shared_ptr<_Up> const& __p) const
4043        {return __cntrl_ < __p.__cntrl_;}
4044    template <class _Up>
4045        _LIBCPP_INLINE_VISIBILITY
4046        bool owner_before(weak_ptr<_Up> const& __p) const
4047        {return __cntrl_ < __p.__cntrl_;}
4048    _LIBCPP_INLINE_VISIBILITY
4049    bool
4050    __owner_equivalent(const shared_ptr& __p) const
4051        {return __cntrl_ == __p.__cntrl_;}
4052
4053#ifndef _LIBCPP_NO_RTTI
4054    template <class _Dp>
4055        _LIBCPP_INLINE_VISIBILITY
4056        _Dp* __get_deleter() const _NOEXCEPT
4057            {return (_Dp*)(__cntrl_ ? __cntrl_->__get_deleter(typeid(_Dp)) : 0);}
4058#endif  // _LIBCPP_NO_RTTI
4059
4060#ifndef _LIBCPP_HAS_NO_VARIADICS
4061
4062    template<class ..._Args>
4063        static
4064        shared_ptr<_Tp>
4065        make_shared(_Args&& ...__args);
4066
4067    template<class _Alloc, class ..._Args>
4068        static
4069        shared_ptr<_Tp>
4070        allocate_shared(const _Alloc& __a, _Args&& ...__args);
4071
4072#else  // _LIBCPP_HAS_NO_VARIADICS
4073
4074    static shared_ptr<_Tp> make_shared();
4075
4076    template<class _A0>
4077        static shared_ptr<_Tp> make_shared(_A0&);
4078
4079    template<class _A0, class _A1>
4080        static shared_ptr<_Tp> make_shared(_A0&, _A1&);
4081
4082    template<class _A0, class _A1, class _A2>
4083        static shared_ptr<_Tp> make_shared(_A0&, _A1&, _A2&);
4084
4085    template<class _Alloc>
4086        static shared_ptr<_Tp>
4087        allocate_shared(const _Alloc& __a);
4088
4089    template<class _Alloc, class _A0>
4090        static shared_ptr<_Tp>
4091        allocate_shared(const _Alloc& __a, _A0& __a0);
4092
4093    template<class _Alloc, class _A0, class _A1>
4094        static shared_ptr<_Tp>
4095        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1);
4096
4097    template<class _Alloc, class _A0, class _A1, class _A2>
4098        static shared_ptr<_Tp>
4099        allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2);
4100
4101#endif  // _LIBCPP_HAS_NO_VARIADICS
4102
4103private:
4104
4105    template <class _Yp>
4106        _LIBCPP_INLINE_VISIBILITY
4107        void
4108        __enable_weak_this(const enable_shared_from_this<_Yp>* __e) _NOEXCEPT
4109        {
4110            if (__e)
4111            {
4112                __e->__weak_this_.__ptr_ = const_cast<_Yp*>(static_cast<const _Yp*>(__e));
4113                __e->__weak_this_.__cntrl_ = __cntrl_;
4114                __cntrl_->__add_weak();
4115            }
4116        }
4117
4118    _LIBCPP_INLINE_VISIBILITY
4119    void __enable_weak_this(const volatile void*) _NOEXCEPT {}
4120
4121    template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY shared_ptr;
4122    template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY weak_ptr;
4123};
4124
4125template<class _Tp>
4126inline _LIBCPP_INLINE_VISIBILITY
4127_LIBCPP_CONSTEXPR
4128shared_ptr<_Tp>::shared_ptr() _NOEXCEPT
4129    : __ptr_(0),
4130      __cntrl_(0)
4131{
4132}
4133
4134template<class _Tp>
4135inline _LIBCPP_INLINE_VISIBILITY
4136_LIBCPP_CONSTEXPR
4137shared_ptr<_Tp>::shared_ptr(nullptr_t) _NOEXCEPT
4138    : __ptr_(0),
4139      __cntrl_(0)
4140{
4141}
4142
4143template<class _Tp>
4144template<class _Yp>
4145shared_ptr<_Tp>::shared_ptr(_Yp* __p,
4146                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4147    : __ptr_(__p)
4148{
4149    unique_ptr<_Yp> __hold(__p);
4150    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
4151    __cntrl_ = new _CntrlBlk(__p, default_delete<_Yp>(), allocator<_Yp>());
4152    __hold.release();
4153    __enable_weak_this(__p);
4154}
4155
4156template<class _Tp>
4157template<class _Yp, class _Dp>
4158shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d,
4159                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4160    : __ptr_(__p)
4161{
4162#ifndef _LIBCPP_NO_EXCEPTIONS
4163    try
4164    {
4165#endif  // _LIBCPP_NO_EXCEPTIONS
4166        typedef __shared_ptr_pointer<_Yp*, _Dp, allocator<_Yp> > _CntrlBlk;
4167        __cntrl_ = new _CntrlBlk(__p, __d, allocator<_Yp>());
4168        __enable_weak_this(__p);
4169#ifndef _LIBCPP_NO_EXCEPTIONS
4170    }
4171    catch (...)
4172    {
4173        __d(__p);
4174        throw;
4175    }
4176#endif  // _LIBCPP_NO_EXCEPTIONS
4177}
4178
4179template<class _Tp>
4180template<class _Dp>
4181shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d)
4182    : __ptr_(0)
4183{
4184#ifndef _LIBCPP_NO_EXCEPTIONS
4185    try
4186    {
4187#endif  // _LIBCPP_NO_EXCEPTIONS
4188        typedef __shared_ptr_pointer<nullptr_t, _Dp, allocator<_Tp> > _CntrlBlk;
4189        __cntrl_ = new _CntrlBlk(__p, __d, allocator<_Tp>());
4190#ifndef _LIBCPP_NO_EXCEPTIONS
4191    }
4192    catch (...)
4193    {
4194        __d(__p);
4195        throw;
4196    }
4197#endif  // _LIBCPP_NO_EXCEPTIONS
4198}
4199
4200template<class _Tp>
4201template<class _Yp, class _Dp, class _Alloc>
4202shared_ptr<_Tp>::shared_ptr(_Yp* __p, _Dp __d, _Alloc __a,
4203                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4204    : __ptr_(__p)
4205{
4206#ifndef _LIBCPP_NO_EXCEPTIONS
4207    try
4208    {
4209#endif  // _LIBCPP_NO_EXCEPTIONS
4210        typedef __shared_ptr_pointer<_Yp*, _Dp, _Alloc> _CntrlBlk;
4211        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4212        typedef __allocator_destructor<_A2> _D2;
4213        _A2 __a2(__a);
4214        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4215        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4216            _CntrlBlk(__p, __d, __a);
4217        __cntrl_ = _VSTD::addressof(*__hold2.release());
4218        __enable_weak_this(__p);
4219#ifndef _LIBCPP_NO_EXCEPTIONS
4220    }
4221    catch (...)
4222    {
4223        __d(__p);
4224        throw;
4225    }
4226#endif  // _LIBCPP_NO_EXCEPTIONS
4227}
4228
4229template<class _Tp>
4230template<class _Dp, class _Alloc>
4231shared_ptr<_Tp>::shared_ptr(nullptr_t __p, _Dp __d, _Alloc __a)
4232    : __ptr_(0)
4233{
4234#ifndef _LIBCPP_NO_EXCEPTIONS
4235    try
4236    {
4237#endif  // _LIBCPP_NO_EXCEPTIONS
4238        typedef __shared_ptr_pointer<nullptr_t, _Dp, _Alloc> _CntrlBlk;
4239        typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4240        typedef __allocator_destructor<_A2> _D2;
4241        _A2 __a2(__a);
4242        unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4243        ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4244            _CntrlBlk(__p, __d, __a);
4245        __cntrl_ = _VSTD::addressof(*__hold2.release());
4246#ifndef _LIBCPP_NO_EXCEPTIONS
4247    }
4248    catch (...)
4249    {
4250        __d(__p);
4251        throw;
4252    }
4253#endif  // _LIBCPP_NO_EXCEPTIONS
4254}
4255
4256template<class _Tp>
4257template<class _Yp>
4258inline _LIBCPP_INLINE_VISIBILITY
4259shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r, element_type *__p) _NOEXCEPT
4260    : __ptr_(__p),
4261      __cntrl_(__r.__cntrl_)
4262{
4263    if (__cntrl_)
4264        __cntrl_->__add_shared();
4265}
4266
4267template<class _Tp>
4268inline _LIBCPP_INLINE_VISIBILITY
4269shared_ptr<_Tp>::shared_ptr(const shared_ptr& __r) _NOEXCEPT
4270    : __ptr_(__r.__ptr_),
4271      __cntrl_(__r.__cntrl_)
4272{
4273    if (__cntrl_)
4274        __cntrl_->__add_shared();
4275}
4276
4277template<class _Tp>
4278template<class _Yp>
4279inline _LIBCPP_INLINE_VISIBILITY
4280shared_ptr<_Tp>::shared_ptr(const shared_ptr<_Yp>& __r,
4281                            typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type)
4282         _NOEXCEPT
4283    : __ptr_(__r.__ptr_),
4284      __cntrl_(__r.__cntrl_)
4285{
4286    if (__cntrl_)
4287        __cntrl_->__add_shared();
4288}
4289
4290#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4291
4292template<class _Tp>
4293inline _LIBCPP_INLINE_VISIBILITY
4294shared_ptr<_Tp>::shared_ptr(shared_ptr&& __r) _NOEXCEPT
4295    : __ptr_(__r.__ptr_),
4296      __cntrl_(__r.__cntrl_)
4297{
4298    __r.__ptr_ = 0;
4299    __r.__cntrl_ = 0;
4300}
4301
4302template<class _Tp>
4303template<class _Yp>
4304inline _LIBCPP_INLINE_VISIBILITY
4305shared_ptr<_Tp>::shared_ptr(shared_ptr<_Yp>&& __r,
4306                            typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type)
4307         _NOEXCEPT
4308    : __ptr_(__r.__ptr_),
4309      __cntrl_(__r.__cntrl_)
4310{
4311    __r.__ptr_ = 0;
4312    __r.__cntrl_ = 0;
4313}
4314
4315#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4316
4317template<class _Tp>
4318template<class _Yp>
4319#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4320shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp>&& __r,
4321#else
4322shared_ptr<_Tp>::shared_ptr(auto_ptr<_Yp> __r,
4323#endif
4324                            typename enable_if<is_convertible<_Yp*, element_type*>::value, __nat>::type)
4325    : __ptr_(__r.get())
4326{
4327    typedef __shared_ptr_pointer<_Yp*, default_delete<_Yp>, allocator<_Yp> > _CntrlBlk;
4328    __cntrl_ = new _CntrlBlk(__r.get(), default_delete<_Yp>(), allocator<_Yp>());
4329    __enable_weak_this(__r.get());
4330    __r.release();
4331}
4332
4333template<class _Tp>
4334template <class _Yp, class _Dp>
4335#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4336shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4337#else
4338shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4339#endif
4340                            typename enable_if
4341                            <
4342                                !is_lvalue_reference<_Dp>::value &&
4343                                !is_array<_Yp>::value &&
4344                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4345                                __nat
4346                            >::type)
4347    : __ptr_(__r.get())
4348{
4349#if _LIBCPP_STD_VER > 11
4350    if (__ptr_ == nullptr)
4351        __cntrl_ = nullptr;
4352    else
4353#endif
4354    {
4355        typedef __shared_ptr_pointer<_Yp*, _Dp, allocator<_Yp> > _CntrlBlk;
4356        __cntrl_ = new _CntrlBlk(__r.get(), __r.get_deleter(), allocator<_Yp>());
4357        __enable_weak_this(__r.get());
4358    }
4359    __r.release();
4360}
4361
4362template<class _Tp>
4363template <class _Yp, class _Dp>
4364#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4365shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp>&& __r,
4366#else
4367shared_ptr<_Tp>::shared_ptr(unique_ptr<_Yp, _Dp> __r,
4368#endif
4369                            typename enable_if
4370                            <
4371                                is_lvalue_reference<_Dp>::value &&
4372                                !is_array<_Yp>::value &&
4373                                is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, element_type*>::value,
4374                                __nat
4375                            >::type)
4376    : __ptr_(__r.get())
4377{
4378#if _LIBCPP_STD_VER > 11
4379    if (__ptr_ == nullptr)
4380        __cntrl_ = nullptr;
4381    else
4382#endif
4383    {
4384        typedef __shared_ptr_pointer<_Yp*,
4385                                     reference_wrapper<typename remove_reference<_Dp>::type>,
4386                                     allocator<_Yp> > _CntrlBlk;
4387        __cntrl_ = new _CntrlBlk(__r.get(), ref(__r.get_deleter()), allocator<_Yp>());
4388        __enable_weak_this(__r.get());
4389    }
4390    __r.release();
4391}
4392
4393#ifndef _LIBCPP_HAS_NO_VARIADICS
4394
4395template<class _Tp>
4396template<class ..._Args>
4397shared_ptr<_Tp>
4398shared_ptr<_Tp>::make_shared(_Args&& ...__args)
4399{
4400    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4401    typedef allocator<_CntrlBlk> _A2;
4402    typedef __allocator_destructor<_A2> _D2;
4403    _A2 __a2;
4404    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4405    ::new(__hold2.get()) _CntrlBlk(__a2, _VSTD::forward<_Args>(__args)...);
4406    shared_ptr<_Tp> __r;
4407    __r.__ptr_ = __hold2.get()->get();
4408    __r.__cntrl_ = __hold2.release();
4409    __r.__enable_weak_this(__r.__ptr_);
4410    return __r;
4411}
4412
4413template<class _Tp>
4414template<class _Alloc, class ..._Args>
4415shared_ptr<_Tp>
4416shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _Args&& ...__args)
4417{
4418    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4419    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _A2;
4420    typedef __allocator_destructor<_A2> _D2;
4421    _A2 __a2(__a);
4422    unique_ptr<_CntrlBlk, _D2> __hold2(__a2.allocate(1), _D2(__a2, 1));
4423    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4424        _CntrlBlk(__a, _VSTD::forward<_Args>(__args)...);
4425    shared_ptr<_Tp> __r;
4426    __r.__ptr_ = __hold2.get()->get();
4427    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4428    __r.__enable_weak_this(__r.__ptr_);
4429    return __r;
4430}
4431
4432#else  // _LIBCPP_HAS_NO_VARIADICS
4433
4434template<class _Tp>
4435shared_ptr<_Tp>
4436shared_ptr<_Tp>::make_shared()
4437{
4438    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4439    typedef allocator<_CntrlBlk> _Alloc2;
4440    typedef __allocator_destructor<_Alloc2> _D2;
4441    _Alloc2 __alloc2;
4442    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4443    ::new(__hold2.get()) _CntrlBlk(__alloc2);
4444    shared_ptr<_Tp> __r;
4445    __r.__ptr_ = __hold2.get()->get();
4446    __r.__cntrl_ = __hold2.release();
4447    __r.__enable_weak_this(__r.__ptr_);
4448    return __r;
4449}
4450
4451template<class _Tp>
4452template<class _A0>
4453shared_ptr<_Tp>
4454shared_ptr<_Tp>::make_shared(_A0& __a0)
4455{
4456    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4457    typedef allocator<_CntrlBlk> _Alloc2;
4458    typedef __allocator_destructor<_Alloc2> _D2;
4459    _Alloc2 __alloc2;
4460    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4461    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0);
4462    shared_ptr<_Tp> __r;
4463    __r.__ptr_ = __hold2.get()->get();
4464    __r.__cntrl_ = __hold2.release();
4465    __r.__enable_weak_this(__r.__ptr_);
4466    return __r;
4467}
4468
4469template<class _Tp>
4470template<class _A0, class _A1>
4471shared_ptr<_Tp>
4472shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1)
4473{
4474    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4475    typedef allocator<_CntrlBlk> _Alloc2;
4476    typedef __allocator_destructor<_Alloc2> _D2;
4477    _Alloc2 __alloc2;
4478    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4479    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1);
4480    shared_ptr<_Tp> __r;
4481    __r.__ptr_ = __hold2.get()->get();
4482    __r.__cntrl_ = __hold2.release();
4483    __r.__enable_weak_this(__r.__ptr_);
4484    return __r;
4485}
4486
4487template<class _Tp>
4488template<class _A0, class _A1, class _A2>
4489shared_ptr<_Tp>
4490shared_ptr<_Tp>::make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
4491{
4492    typedef __shared_ptr_emplace<_Tp, allocator<_Tp> > _CntrlBlk;
4493    typedef allocator<_CntrlBlk> _Alloc2;
4494    typedef __allocator_destructor<_Alloc2> _D2;
4495    _Alloc2 __alloc2;
4496    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4497    ::new(__hold2.get()) _CntrlBlk(__alloc2, __a0, __a1, __a2);
4498    shared_ptr<_Tp> __r;
4499    __r.__ptr_ = __hold2.get()->get();
4500    __r.__cntrl_ = __hold2.release();
4501    __r.__enable_weak_this(__r.__ptr_);
4502    return __r;
4503}
4504
4505template<class _Tp>
4506template<class _Alloc>
4507shared_ptr<_Tp>
4508shared_ptr<_Tp>::allocate_shared(const _Alloc& __a)
4509{
4510    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4511    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4512    typedef __allocator_destructor<_Alloc2> _D2;
4513    _Alloc2 __alloc2(__a);
4514    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4515    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4516        _CntrlBlk(__a);
4517    shared_ptr<_Tp> __r;
4518    __r.__ptr_ = __hold2.get()->get();
4519    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4520    __r.__enable_weak_this(__r.__ptr_);
4521    return __r;
4522}
4523
4524template<class _Tp>
4525template<class _Alloc, class _A0>
4526shared_ptr<_Tp>
4527shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0)
4528{
4529    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4530    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4531    typedef __allocator_destructor<_Alloc2> _D2;
4532    _Alloc2 __alloc2(__a);
4533    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4534    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4535        _CntrlBlk(__a, __a0);
4536    shared_ptr<_Tp> __r;
4537    __r.__ptr_ = __hold2.get()->get();
4538    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4539    __r.__enable_weak_this(__r.__ptr_);
4540    return __r;
4541}
4542
4543template<class _Tp>
4544template<class _Alloc, class _A0, class _A1>
4545shared_ptr<_Tp>
4546shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
4547{
4548    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4549    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4550    typedef __allocator_destructor<_Alloc2> _D2;
4551    _Alloc2 __alloc2(__a);
4552    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4553    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4554        _CntrlBlk(__a, __a0, __a1);
4555    shared_ptr<_Tp> __r;
4556    __r.__ptr_ = __hold2.get()->get();
4557    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4558    __r.__enable_weak_this(__r.__ptr_);
4559    return __r;
4560}
4561
4562template<class _Tp>
4563template<class _Alloc, class _A0, class _A1, class _A2>
4564shared_ptr<_Tp>
4565shared_ptr<_Tp>::allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
4566{
4567    typedef __shared_ptr_emplace<_Tp, _Alloc> _CntrlBlk;
4568    typedef typename __allocator_traits_rebind<_Alloc, _CntrlBlk>::type _Alloc2;
4569    typedef __allocator_destructor<_Alloc2> _D2;
4570    _Alloc2 __alloc2(__a);
4571    unique_ptr<_CntrlBlk, _D2> __hold2(__alloc2.allocate(1), _D2(__alloc2, 1));
4572    ::new(static_cast<void*>(_VSTD::addressof(*__hold2.get())))
4573        _CntrlBlk(__a, __a0, __a1, __a2);
4574    shared_ptr<_Tp> __r;
4575    __r.__ptr_ = __hold2.get()->get();
4576    __r.__cntrl_ = _VSTD::addressof(*__hold2.release());
4577    __r.__enable_weak_this(__r.__ptr_);
4578    return __r;
4579}
4580
4581#endif  // _LIBCPP_HAS_NO_VARIADICS
4582
4583template<class _Tp>
4584shared_ptr<_Tp>::~shared_ptr()
4585{
4586    if (__cntrl_)
4587        __cntrl_->__release_shared();
4588}
4589
4590template<class _Tp>
4591inline _LIBCPP_INLINE_VISIBILITY
4592shared_ptr<_Tp>&
4593shared_ptr<_Tp>::operator=(const shared_ptr& __r) _NOEXCEPT
4594{
4595    shared_ptr(__r).swap(*this);
4596    return *this;
4597}
4598
4599template<class _Tp>
4600template<class _Yp>
4601inline _LIBCPP_INLINE_VISIBILITY
4602typename enable_if
4603<
4604    is_convertible<_Yp*, _Tp*>::value,
4605    shared_ptr<_Tp>&
4606>::type
4607shared_ptr<_Tp>::operator=(const shared_ptr<_Yp>& __r) _NOEXCEPT
4608{
4609    shared_ptr(__r).swap(*this);
4610    return *this;
4611}
4612
4613#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
4614
4615template<class _Tp>
4616inline _LIBCPP_INLINE_VISIBILITY
4617shared_ptr<_Tp>&
4618shared_ptr<_Tp>::operator=(shared_ptr&& __r) _NOEXCEPT
4619{
4620    shared_ptr(_VSTD::move(__r)).swap(*this);
4621    return *this;
4622}
4623
4624template<class _Tp>
4625template<class _Yp>
4626inline _LIBCPP_INLINE_VISIBILITY
4627typename enable_if
4628<
4629    is_convertible<_Yp*, _Tp*>::value,
4630    shared_ptr<_Tp>&
4631>::type
4632shared_ptr<_Tp>::operator=(shared_ptr<_Yp>&& __r)
4633{
4634    shared_ptr(_VSTD::move(__r)).swap(*this);
4635    return *this;
4636}
4637
4638template<class _Tp>
4639template<class _Yp>
4640inline _LIBCPP_INLINE_VISIBILITY
4641typename enable_if
4642<
4643    !is_array<_Yp>::value &&
4644    is_convertible<_Yp*, _Tp*>::value,
4645    shared_ptr<_Tp>
4646>::type&
4647shared_ptr<_Tp>::operator=(auto_ptr<_Yp>&& __r)
4648{
4649    shared_ptr(_VSTD::move(__r)).swap(*this);
4650    return *this;
4651}
4652
4653template<class _Tp>
4654template <class _Yp, class _Dp>
4655inline _LIBCPP_INLINE_VISIBILITY
4656typename enable_if
4657<
4658    !is_array<_Yp>::value &&
4659    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, _Tp*>::value,
4660    shared_ptr<_Tp>&
4661>::type
4662shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp>&& __r)
4663{
4664    shared_ptr(_VSTD::move(__r)).swap(*this);
4665    return *this;
4666}
4667
4668#else  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4669
4670template<class _Tp>
4671template<class _Yp>
4672inline _LIBCPP_INLINE_VISIBILITY
4673typename enable_if
4674<
4675    !is_array<_Yp>::value &&
4676    is_convertible<_Yp*, _Tp*>::value,
4677    shared_ptr<_Tp>&
4678>::type
4679shared_ptr<_Tp>::operator=(auto_ptr<_Yp> __r)
4680{
4681    shared_ptr(__r).swap(*this);
4682    return *this;
4683}
4684
4685template<class _Tp>
4686template <class _Yp, class _Dp>
4687inline _LIBCPP_INLINE_VISIBILITY
4688typename enable_if
4689<
4690    !is_array<_Yp>::value &&
4691    is_convertible<typename unique_ptr<_Yp, _Dp>::pointer, _Tp*>::value,
4692    shared_ptr<_Tp>&
4693>::type
4694shared_ptr<_Tp>::operator=(unique_ptr<_Yp, _Dp> __r)
4695{
4696    shared_ptr(_VSTD::move(__r)).swap(*this);
4697    return *this;
4698}
4699
4700#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
4701
4702template<class _Tp>
4703inline _LIBCPP_INLINE_VISIBILITY
4704void
4705shared_ptr<_Tp>::swap(shared_ptr& __r) _NOEXCEPT
4706{
4707    _VSTD::swap(__ptr_, __r.__ptr_);
4708    _VSTD::swap(__cntrl_, __r.__cntrl_);
4709}
4710
4711template<class _Tp>
4712inline _LIBCPP_INLINE_VISIBILITY
4713void
4714shared_ptr<_Tp>::reset() _NOEXCEPT
4715{
4716    shared_ptr().swap(*this);
4717}
4718
4719template<class _Tp>
4720template<class _Yp>
4721inline _LIBCPP_INLINE_VISIBILITY
4722typename enable_if
4723<
4724    is_convertible<_Yp*, _Tp*>::value,
4725    void
4726>::type
4727shared_ptr<_Tp>::reset(_Yp* __p)
4728{
4729    shared_ptr(__p).swap(*this);
4730}
4731
4732template<class _Tp>
4733template<class _Yp, class _Dp>
4734inline _LIBCPP_INLINE_VISIBILITY
4735typename enable_if
4736<
4737    is_convertible<_Yp*, _Tp*>::value,
4738    void
4739>::type
4740shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d)
4741{
4742    shared_ptr(__p, __d).swap(*this);
4743}
4744
4745template<class _Tp>
4746template<class _Yp, class _Dp, class _Alloc>
4747inline _LIBCPP_INLINE_VISIBILITY
4748typename enable_if
4749<
4750    is_convertible<_Yp*, _Tp*>::value,
4751    void
4752>::type
4753shared_ptr<_Tp>::reset(_Yp* __p, _Dp __d, _Alloc __a)
4754{
4755    shared_ptr(__p, __d, __a).swap(*this);
4756}
4757
4758#ifndef _LIBCPP_HAS_NO_VARIADICS
4759
4760template<class _Tp, class ..._Args>
4761inline _LIBCPP_INLINE_VISIBILITY
4762typename enable_if
4763<
4764    !is_array<_Tp>::value,
4765    shared_ptr<_Tp>
4766>::type
4767make_shared(_Args&& ...__args)
4768{
4769    return shared_ptr<_Tp>::make_shared(_VSTD::forward<_Args>(__args)...);
4770}
4771
4772template<class _Tp, class _Alloc, class ..._Args>
4773inline _LIBCPP_INLINE_VISIBILITY
4774typename enable_if
4775<
4776    !is_array<_Tp>::value,
4777    shared_ptr<_Tp>
4778>::type
4779allocate_shared(const _Alloc& __a, _Args&& ...__args)
4780{
4781    return shared_ptr<_Tp>::allocate_shared(__a, _VSTD::forward<_Args>(__args)...);
4782}
4783
4784#else  // _LIBCPP_HAS_NO_VARIADICS
4785
4786template<class _Tp>
4787inline _LIBCPP_INLINE_VISIBILITY
4788shared_ptr<_Tp>
4789make_shared()
4790{
4791    return shared_ptr<_Tp>::make_shared();
4792}
4793
4794template<class _Tp, class _A0>
4795inline _LIBCPP_INLINE_VISIBILITY
4796shared_ptr<_Tp>
4797make_shared(_A0& __a0)
4798{
4799    return shared_ptr<_Tp>::make_shared(__a0);
4800}
4801
4802template<class _Tp, class _A0, class _A1>
4803inline _LIBCPP_INLINE_VISIBILITY
4804shared_ptr<_Tp>
4805make_shared(_A0& __a0, _A1& __a1)
4806{
4807    return shared_ptr<_Tp>::make_shared(__a0, __a1);
4808}
4809
4810template<class _Tp, class _A0, class _A1, class _A2>
4811inline _LIBCPP_INLINE_VISIBILITY
4812shared_ptr<_Tp>
4813make_shared(_A0& __a0, _A1& __a1, _A2& __a2)
4814{
4815    return shared_ptr<_Tp>::make_shared(__a0, __a1, __a2);
4816}
4817
4818template<class _Tp, class _Alloc>
4819inline _LIBCPP_INLINE_VISIBILITY
4820shared_ptr<_Tp>
4821allocate_shared(const _Alloc& __a)
4822{
4823    return shared_ptr<_Tp>::allocate_shared(__a);
4824}
4825
4826template<class _Tp, class _Alloc, class _A0>
4827inline _LIBCPP_INLINE_VISIBILITY
4828shared_ptr<_Tp>
4829allocate_shared(const _Alloc& __a, _A0& __a0)
4830{
4831    return shared_ptr<_Tp>::allocate_shared(__a, __a0);
4832}
4833
4834template<class _Tp, class _Alloc, class _A0, class _A1>
4835inline _LIBCPP_INLINE_VISIBILITY
4836shared_ptr<_Tp>
4837allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1)
4838{
4839    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1);
4840}
4841
4842template<class _Tp, class _Alloc, class _A0, class _A1, class _A2>
4843inline _LIBCPP_INLINE_VISIBILITY
4844shared_ptr<_Tp>
4845allocate_shared(const _Alloc& __a, _A0& __a0, _A1& __a1, _A2& __a2)
4846{
4847    return shared_ptr<_Tp>::allocate_shared(__a, __a0, __a1, __a2);
4848}
4849
4850#endif  // _LIBCPP_HAS_NO_VARIADICS
4851
4852template<class _Tp, class _Up>
4853inline _LIBCPP_INLINE_VISIBILITY
4854bool
4855operator==(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4856{
4857    return __x.get() == __y.get();
4858}
4859
4860template<class _Tp, class _Up>
4861inline _LIBCPP_INLINE_VISIBILITY
4862bool
4863operator!=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4864{
4865    return !(__x == __y);
4866}
4867
4868template<class _Tp, class _Up>
4869inline _LIBCPP_INLINE_VISIBILITY
4870bool
4871operator<(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4872{
4873    typedef typename common_type<_Tp*, _Up*>::type _Vp;
4874    return less<_Vp>()(__x.get(), __y.get());
4875}
4876
4877template<class _Tp, class _Up>
4878inline _LIBCPP_INLINE_VISIBILITY
4879bool
4880operator>(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4881{
4882    return __y < __x;
4883}
4884
4885template<class _Tp, class _Up>
4886inline _LIBCPP_INLINE_VISIBILITY
4887bool
4888operator<=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4889{
4890    return !(__y < __x);
4891}
4892
4893template<class _Tp, class _Up>
4894inline _LIBCPP_INLINE_VISIBILITY
4895bool
4896operator>=(const shared_ptr<_Tp>& __x, const shared_ptr<_Up>& __y) _NOEXCEPT
4897{
4898    return !(__x < __y);
4899}
4900
4901template<class _Tp>
4902inline _LIBCPP_INLINE_VISIBILITY
4903bool
4904operator==(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4905{
4906    return !__x;
4907}
4908
4909template<class _Tp>
4910inline _LIBCPP_INLINE_VISIBILITY
4911bool
4912operator==(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4913{
4914    return !__x;
4915}
4916
4917template<class _Tp>
4918inline _LIBCPP_INLINE_VISIBILITY
4919bool
4920operator!=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4921{
4922    return static_cast<bool>(__x);
4923}
4924
4925template<class _Tp>
4926inline _LIBCPP_INLINE_VISIBILITY
4927bool
4928operator!=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4929{
4930    return static_cast<bool>(__x);
4931}
4932
4933template<class _Tp>
4934inline _LIBCPP_INLINE_VISIBILITY
4935bool
4936operator<(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4937{
4938    return less<_Tp*>()(__x.get(), nullptr);
4939}
4940
4941template<class _Tp>
4942inline _LIBCPP_INLINE_VISIBILITY
4943bool
4944operator<(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4945{
4946    return less<_Tp*>()(nullptr, __x.get());
4947}
4948
4949template<class _Tp>
4950inline _LIBCPP_INLINE_VISIBILITY
4951bool
4952operator>(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4953{
4954    return nullptr < __x;
4955}
4956
4957template<class _Tp>
4958inline _LIBCPP_INLINE_VISIBILITY
4959bool
4960operator>(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4961{
4962    return __x < nullptr;
4963}
4964
4965template<class _Tp>
4966inline _LIBCPP_INLINE_VISIBILITY
4967bool
4968operator<=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4969{
4970    return !(nullptr < __x);
4971}
4972
4973template<class _Tp>
4974inline _LIBCPP_INLINE_VISIBILITY
4975bool
4976operator<=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4977{
4978    return !(__x < nullptr);
4979}
4980
4981template<class _Tp>
4982inline _LIBCPP_INLINE_VISIBILITY
4983bool
4984operator>=(const shared_ptr<_Tp>& __x, nullptr_t) _NOEXCEPT
4985{
4986    return !(__x < nullptr);
4987}
4988
4989template<class _Tp>
4990inline _LIBCPP_INLINE_VISIBILITY
4991bool
4992operator>=(nullptr_t, const shared_ptr<_Tp>& __x) _NOEXCEPT
4993{
4994    return !(nullptr < __x);
4995}
4996
4997template<class _Tp>
4998inline _LIBCPP_INLINE_VISIBILITY
4999void
5000swap(shared_ptr<_Tp>& __x, shared_ptr<_Tp>& __y) _NOEXCEPT
5001{
5002    __x.swap(__y);
5003}
5004
5005template<class _Tp, class _Up>
5006inline _LIBCPP_INLINE_VISIBILITY
5007typename enable_if
5008<
5009    !is_array<_Tp>::value && !is_array<_Up>::value,
5010    shared_ptr<_Tp>
5011>::type
5012static_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
5013{
5014    return shared_ptr<_Tp>(__r, static_cast<_Tp*>(__r.get()));
5015}
5016
5017template<class _Tp, class _Up>
5018inline _LIBCPP_INLINE_VISIBILITY
5019typename enable_if
5020<
5021    !is_array<_Tp>::value && !is_array<_Up>::value,
5022    shared_ptr<_Tp>
5023>::type
5024dynamic_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
5025{
5026    _Tp* __p = dynamic_cast<_Tp*>(__r.get());
5027    return __p ? shared_ptr<_Tp>(__r, __p) : shared_ptr<_Tp>();
5028}
5029
5030template<class _Tp, class _Up>
5031typename enable_if
5032<
5033    is_array<_Tp>::value == is_array<_Up>::value,
5034    shared_ptr<_Tp>
5035>::type
5036const_pointer_cast(const shared_ptr<_Up>& __r) _NOEXCEPT
5037{
5038    typedef typename remove_extent<_Tp>::type _RTp;
5039    return shared_ptr<_Tp>(__r, const_cast<_RTp*>(__r.get()));
5040}
5041
5042#ifndef _LIBCPP_NO_RTTI
5043
5044template<class _Dp, class _Tp>
5045inline _LIBCPP_INLINE_VISIBILITY
5046_Dp*
5047get_deleter(const shared_ptr<_Tp>& __p) _NOEXCEPT
5048{
5049    return __p.template __get_deleter<_Dp>();
5050}
5051
5052#endif  // _LIBCPP_NO_RTTI
5053
5054template<class _Tp>
5055class _LIBCPP_TYPE_VIS_ONLY weak_ptr
5056{
5057public:
5058    typedef _Tp element_type;
5059private:
5060    element_type*        __ptr_;
5061    __shared_weak_count* __cntrl_;
5062
5063public:
5064    _LIBCPP_CONSTEXPR weak_ptr() _NOEXCEPT;
5065    template<class _Yp> weak_ptr(shared_ptr<_Yp> const& __r,
5066                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
5067                        _NOEXCEPT;
5068    weak_ptr(weak_ptr const& __r) _NOEXCEPT;
5069    template<class _Yp> weak_ptr(weak_ptr<_Yp> const& __r,
5070                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
5071                         _NOEXCEPT;
5072
5073#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5074    weak_ptr(weak_ptr&& __r) _NOEXCEPT;
5075    template<class _Yp> weak_ptr(weak_ptr<_Yp>&& __r,
5076                   typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type = 0)
5077                         _NOEXCEPT;
5078#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5079    ~weak_ptr();
5080
5081    weak_ptr& operator=(weak_ptr const& __r) _NOEXCEPT;
5082    template<class _Yp>
5083        typename enable_if
5084        <
5085            is_convertible<_Yp*, element_type*>::value,
5086            weak_ptr&
5087        >::type
5088        operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT;
5089
5090#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5091
5092    weak_ptr& operator=(weak_ptr&& __r) _NOEXCEPT;
5093    template<class _Yp>
5094        typename enable_if
5095        <
5096            is_convertible<_Yp*, element_type*>::value,
5097            weak_ptr&
5098        >::type
5099        operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT;
5100
5101#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5102
5103    template<class _Yp>
5104        typename enable_if
5105        <
5106            is_convertible<_Yp*, element_type*>::value,
5107            weak_ptr&
5108        >::type
5109        operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT;
5110
5111    void swap(weak_ptr& __r) _NOEXCEPT;
5112    void reset() _NOEXCEPT;
5113
5114    _LIBCPP_INLINE_VISIBILITY
5115    long use_count() const _NOEXCEPT
5116        {return __cntrl_ ? __cntrl_->use_count() : 0;}
5117    _LIBCPP_INLINE_VISIBILITY
5118    bool expired() const _NOEXCEPT
5119        {return __cntrl_ == 0 || __cntrl_->use_count() == 0;}
5120    shared_ptr<_Tp> lock() const _NOEXCEPT;
5121    template<class _Up>
5122        _LIBCPP_INLINE_VISIBILITY
5123        bool owner_before(const shared_ptr<_Up>& __r) const
5124        {return __cntrl_ < __r.__cntrl_;}
5125    template<class _Up>
5126        _LIBCPP_INLINE_VISIBILITY
5127        bool owner_before(const weak_ptr<_Up>& __r) const
5128        {return __cntrl_ < __r.__cntrl_;}
5129
5130    template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY weak_ptr;
5131    template <class _Up> friend class _LIBCPP_TYPE_VIS_ONLY shared_ptr;
5132};
5133
5134template<class _Tp>
5135inline _LIBCPP_INLINE_VISIBILITY
5136_LIBCPP_CONSTEXPR
5137weak_ptr<_Tp>::weak_ptr() _NOEXCEPT
5138    : __ptr_(0),
5139      __cntrl_(0)
5140{
5141}
5142
5143template<class _Tp>
5144inline _LIBCPP_INLINE_VISIBILITY
5145weak_ptr<_Tp>::weak_ptr(weak_ptr const& __r) _NOEXCEPT
5146    : __ptr_(__r.__ptr_),
5147      __cntrl_(__r.__cntrl_)
5148{
5149    if (__cntrl_)
5150        __cntrl_->__add_weak();
5151}
5152
5153template<class _Tp>
5154template<class _Yp>
5155inline _LIBCPP_INLINE_VISIBILITY
5156weak_ptr<_Tp>::weak_ptr(shared_ptr<_Yp> const& __r,
5157                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5158                         _NOEXCEPT
5159    : __ptr_(__r.__ptr_),
5160      __cntrl_(__r.__cntrl_)
5161{
5162    if (__cntrl_)
5163        __cntrl_->__add_weak();
5164}
5165
5166template<class _Tp>
5167template<class _Yp>
5168inline _LIBCPP_INLINE_VISIBILITY
5169weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp> const& __r,
5170                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5171         _NOEXCEPT
5172    : __ptr_(__r.__ptr_),
5173      __cntrl_(__r.__cntrl_)
5174{
5175    if (__cntrl_)
5176        __cntrl_->__add_weak();
5177}
5178
5179#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5180
5181template<class _Tp>
5182inline _LIBCPP_INLINE_VISIBILITY
5183weak_ptr<_Tp>::weak_ptr(weak_ptr&& __r) _NOEXCEPT
5184    : __ptr_(__r.__ptr_),
5185      __cntrl_(__r.__cntrl_)
5186{
5187    __r.__ptr_ = 0;
5188    __r.__cntrl_ = 0;
5189}
5190
5191template<class _Tp>
5192template<class _Yp>
5193inline _LIBCPP_INLINE_VISIBILITY
5194weak_ptr<_Tp>::weak_ptr(weak_ptr<_Yp>&& __r,
5195                        typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat*>::type)
5196         _NOEXCEPT
5197    : __ptr_(__r.__ptr_),
5198      __cntrl_(__r.__cntrl_)
5199{
5200    __r.__ptr_ = 0;
5201    __r.__cntrl_ = 0;
5202}
5203
5204#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5205
5206template<class _Tp>
5207weak_ptr<_Tp>::~weak_ptr()
5208{
5209    if (__cntrl_)
5210        __cntrl_->__release_weak();
5211}
5212
5213template<class _Tp>
5214inline _LIBCPP_INLINE_VISIBILITY
5215weak_ptr<_Tp>&
5216weak_ptr<_Tp>::operator=(weak_ptr const& __r) _NOEXCEPT
5217{
5218    weak_ptr(__r).swap(*this);
5219    return *this;
5220}
5221
5222template<class _Tp>
5223template<class _Yp>
5224inline _LIBCPP_INLINE_VISIBILITY
5225typename enable_if
5226<
5227    is_convertible<_Yp*, _Tp*>::value,
5228    weak_ptr<_Tp>&
5229>::type
5230weak_ptr<_Tp>::operator=(weak_ptr<_Yp> const& __r) _NOEXCEPT
5231{
5232    weak_ptr(__r).swap(*this);
5233    return *this;
5234}
5235
5236#ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
5237
5238template<class _Tp>
5239inline _LIBCPP_INLINE_VISIBILITY
5240weak_ptr<_Tp>&
5241weak_ptr<_Tp>::operator=(weak_ptr&& __r) _NOEXCEPT
5242{
5243    weak_ptr(_VSTD::move(__r)).swap(*this);
5244    return *this;
5245}
5246
5247template<class _Tp>
5248template<class _Yp>
5249inline _LIBCPP_INLINE_VISIBILITY
5250typename enable_if
5251<
5252    is_convertible<_Yp*, _Tp*>::value,
5253    weak_ptr<_Tp>&
5254>::type
5255weak_ptr<_Tp>::operator=(weak_ptr<_Yp>&& __r) _NOEXCEPT
5256{
5257    weak_ptr(_VSTD::move(__r)).swap(*this);
5258    return *this;
5259}
5260
5261#endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
5262
5263template<class _Tp>
5264template<class _Yp>
5265inline _LIBCPP_INLINE_VISIBILITY
5266typename enable_if
5267<
5268    is_convertible<_Yp*, _Tp*>::value,
5269    weak_ptr<_Tp>&
5270>::type
5271weak_ptr<_Tp>::operator=(shared_ptr<_Yp> const& __r) _NOEXCEPT
5272{
5273    weak_ptr(__r).swap(*this);
5274    return *this;
5275}
5276
5277template<class _Tp>
5278inline _LIBCPP_INLINE_VISIBILITY
5279void
5280weak_ptr<_Tp>::swap(weak_ptr& __r) _NOEXCEPT
5281{
5282    _VSTD::swap(__ptr_, __r.__ptr_);
5283    _VSTD::swap(__cntrl_, __r.__cntrl_);
5284}
5285
5286template<class _Tp>
5287inline _LIBCPP_INLINE_VISIBILITY
5288void
5289swap(weak_ptr<_Tp>& __x, weak_ptr<_Tp>& __y) _NOEXCEPT
5290{
5291    __x.swap(__y);
5292}
5293
5294template<class _Tp>
5295inline _LIBCPP_INLINE_VISIBILITY
5296void
5297weak_ptr<_Tp>::reset() _NOEXCEPT
5298{
5299    weak_ptr().swap(*this);
5300}
5301
5302template<class _Tp>
5303template<class _Yp>
5304shared_ptr<_Tp>::shared_ptr(const weak_ptr<_Yp>& __r,
5305                            typename enable_if<is_convertible<_Yp*, _Tp*>::value, __nat>::type)
5306    : __ptr_(__r.__ptr_),
5307      __cntrl_(__r.__cntrl_ ? __r.__cntrl_->lock() : __r.__cntrl_)
5308{
5309    if (__cntrl_ == 0)
5310#ifndef _LIBCPP_NO_EXCEPTIONS
5311        throw bad_weak_ptr();
5312#else
5313        assert(!"bad_weak_ptr");
5314#endif
5315}
5316
5317template<class _Tp>
5318shared_ptr<_Tp>
5319weak_ptr<_Tp>::lock() const _NOEXCEPT
5320{
5321    shared_ptr<_Tp> __r;
5322    __r.__cntrl_ = __cntrl_ ? __cntrl_->lock() : __cntrl_;
5323    if (__r.__cntrl_)
5324        __r.__ptr_ = __ptr_;
5325    return __r;
5326}
5327
5328template <class _Tp> struct owner_less;
5329
5330template <class _Tp>
5331struct _LIBCPP_TYPE_VIS_ONLY owner_less<shared_ptr<_Tp> >
5332    : binary_function<shared_ptr<_Tp>, shared_ptr<_Tp>, bool>
5333{
5334    typedef bool result_type;
5335    _LIBCPP_INLINE_VISIBILITY
5336    bool operator()(shared_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const
5337        {return __x.owner_before(__y);}
5338    _LIBCPP_INLINE_VISIBILITY
5339    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const
5340        {return __x.owner_before(__y);}
5341    _LIBCPP_INLINE_VISIBILITY
5342    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const
5343        {return __x.owner_before(__y);}
5344};
5345
5346template <class _Tp>
5347struct _LIBCPP_TYPE_VIS_ONLY owner_less<weak_ptr<_Tp> >
5348    : binary_function<weak_ptr<_Tp>, weak_ptr<_Tp>, bool>
5349{
5350    typedef bool result_type;
5351    _LIBCPP_INLINE_VISIBILITY
5352    bool operator()(  weak_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const
5353        {return __x.owner_before(__y);}
5354    _LIBCPP_INLINE_VISIBILITY
5355    bool operator()(shared_ptr<_Tp> const& __x,   weak_ptr<_Tp> const& __y) const
5356        {return __x.owner_before(__y);}
5357    _LIBCPP_INLINE_VISIBILITY
5358    bool operator()(  weak_ptr<_Tp> const& __x, shared_ptr<_Tp> const& __y) const
5359        {return __x.owner_before(__y);}
5360};
5361
5362template<class _Tp>
5363class _LIBCPP_TYPE_VIS_ONLY enable_shared_from_this
5364{
5365    mutable weak_ptr<_Tp> __weak_this_;
5366protected:
5367    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
5368    enable_shared_from_this() _NOEXCEPT {}
5369    _LIBCPP_INLINE_VISIBILITY
5370    enable_shared_from_this(enable_shared_from_this const&) _NOEXCEPT {}
5371    _LIBCPP_INLINE_VISIBILITY
5372    enable_shared_from_this& operator=(enable_shared_from_this const&) _NOEXCEPT
5373        {return *this;}
5374    _LIBCPP_INLINE_VISIBILITY
5375    ~enable_shared_from_this() {}
5376public:
5377    _LIBCPP_INLINE_VISIBILITY
5378    shared_ptr<_Tp> shared_from_this()
5379        {return shared_ptr<_Tp>(__weak_this_);}
5380    _LIBCPP_INLINE_VISIBILITY
5381    shared_ptr<_Tp const> shared_from_this() const
5382        {return shared_ptr<const _Tp>(__weak_this_);}
5383
5384    template <class _Up> friend class shared_ptr;
5385};
5386
5387template <class _Tp>
5388struct _LIBCPP_TYPE_VIS_ONLY hash<shared_ptr<_Tp> >
5389{
5390    typedef shared_ptr<_Tp>      argument_type;
5391    typedef size_t               result_type;
5392    _LIBCPP_INLINE_VISIBILITY
5393    result_type operator()(const argument_type& __ptr) const _NOEXCEPT
5394    {
5395        return hash<_Tp*>()(__ptr.get());
5396    }
5397};
5398
5399template<class _CharT, class _Traits, class _Yp>
5400inline _LIBCPP_INLINE_VISIBILITY
5401basic_ostream<_CharT, _Traits>&
5402operator<<(basic_ostream<_CharT, _Traits>& __os, shared_ptr<_Yp> const& __p);
5403
5404// TODO(EricWF): Enable this for both Clang and GCC. Currently it is only
5405// enabled with clang.
5406#if defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_NO_THREADS)
5407
5408class _LIBCPP_TYPE_VIS __sp_mut
5409{
5410    void* __lx;
5411public:
5412    void lock() _NOEXCEPT;
5413    void unlock() _NOEXCEPT;
5414
5415private:
5416    _LIBCPP_CONSTEXPR __sp_mut(void*) _NOEXCEPT;
5417    __sp_mut(const __sp_mut&);
5418    __sp_mut& operator=(const __sp_mut&);
5419
5420    friend _LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
5421};
5422
5423_LIBCPP_FUNC_VIS __sp_mut& __get_sp_mut(const void*);
5424
5425template <class _Tp>
5426inline _LIBCPP_INLINE_VISIBILITY
5427bool
5428atomic_is_lock_free(const shared_ptr<_Tp>*)
5429{
5430    return false;
5431}
5432
5433template <class _Tp>
5434shared_ptr<_Tp>
5435atomic_load(const shared_ptr<_Tp>* __p)
5436{
5437    __sp_mut& __m = __get_sp_mut(__p);
5438    __m.lock();
5439    shared_ptr<_Tp> __q = *__p;
5440    __m.unlock();
5441    return __q;
5442}
5443
5444template <class _Tp>
5445inline _LIBCPP_INLINE_VISIBILITY
5446shared_ptr<_Tp>
5447atomic_load_explicit(const shared_ptr<_Tp>* __p, memory_order)
5448{
5449    return atomic_load(__p);
5450}
5451
5452template <class _Tp>
5453void
5454atomic_store(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5455{
5456    __sp_mut& __m = __get_sp_mut(__p);
5457    __m.lock();
5458    __p->swap(__r);
5459    __m.unlock();
5460}
5461
5462template <class _Tp>
5463inline _LIBCPP_INLINE_VISIBILITY
5464void
5465atomic_store_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5466{
5467    atomic_store(__p, __r);
5468}
5469
5470template <class _Tp>
5471shared_ptr<_Tp>
5472atomic_exchange(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r)
5473{
5474    __sp_mut& __m = __get_sp_mut(__p);
5475    __m.lock();
5476    __p->swap(__r);
5477    __m.unlock();
5478    return __r;
5479}
5480
5481template <class _Tp>
5482inline _LIBCPP_INLINE_VISIBILITY
5483shared_ptr<_Tp>
5484atomic_exchange_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp> __r, memory_order)
5485{
5486    return atomic_exchange(__p, __r);
5487}
5488
5489template <class _Tp>
5490bool
5491atomic_compare_exchange_strong(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5492{
5493    __sp_mut& __m = __get_sp_mut(__p);
5494    __m.lock();
5495    if (__p->__owner_equivalent(*__v))
5496    {
5497        *__p = __w;
5498        __m.unlock();
5499        return true;
5500    }
5501    *__v = *__p;
5502    __m.unlock();
5503    return false;
5504}
5505
5506template <class _Tp>
5507inline _LIBCPP_INLINE_VISIBILITY
5508bool
5509atomic_compare_exchange_weak(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v, shared_ptr<_Tp> __w)
5510{
5511    return atomic_compare_exchange_strong(__p, __v, __w);
5512}
5513
5514template <class _Tp>
5515inline _LIBCPP_INLINE_VISIBILITY
5516bool
5517atomic_compare_exchange_strong_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5518                                        shared_ptr<_Tp> __w, memory_order, memory_order)
5519{
5520    return atomic_compare_exchange_strong(__p, __v, __w);
5521}
5522
5523template <class _Tp>
5524inline _LIBCPP_INLINE_VISIBILITY
5525bool
5526atomic_compare_exchange_weak_explicit(shared_ptr<_Tp>* __p, shared_ptr<_Tp>* __v,
5527                                      shared_ptr<_Tp> __w, memory_order, memory_order)
5528{
5529    return atomic_compare_exchange_weak(__p, __v, __w);
5530}
5531
5532#endif  // defined(_LIBCPP_HAS_C_ATOMIC_IMP) && !defined(_LIBCPP_HAS_NO_THREADS)
5533
5534//enum class
5535struct _LIBCPP_TYPE_VIS pointer_safety
5536{
5537    enum __lx
5538    {
5539        relaxed,
5540        preferred,
5541        strict
5542    };
5543
5544    __lx __v_;
5545
5546    _LIBCPP_INLINE_VISIBILITY
5547    pointer_safety(__lx __v) : __v_(__v) {}
5548    _LIBCPP_INLINE_VISIBILITY
5549    operator int() const {return __v_;}
5550};
5551
5552_LIBCPP_FUNC_VIS void declare_reachable(void* __p);
5553_LIBCPP_FUNC_VIS void declare_no_pointers(char* __p, size_t __n);
5554_LIBCPP_FUNC_VIS void undeclare_no_pointers(char* __p, size_t __n);
5555_LIBCPP_FUNC_VIS pointer_safety get_pointer_safety() _NOEXCEPT;
5556_LIBCPP_FUNC_VIS void* __undeclare_reachable(void* __p);
5557
5558template <class _Tp>
5559inline _LIBCPP_INLINE_VISIBILITY
5560_Tp*
5561undeclare_reachable(_Tp* __p)
5562{
5563    return static_cast<_Tp*>(__undeclare_reachable(__p));
5564}
5565
5566_LIBCPP_FUNC_VIS void* align(size_t __align, size_t __sz, void*& __ptr, size_t& __space);
5567
5568// --- Helper for container swap --
5569template <typename _Alloc>
5570_LIBCPP_INLINE_VISIBILITY
5571void __swap_allocator(_Alloc & __a1, _Alloc & __a2)
5572#if _LIBCPP_STD_VER >= 14
5573    _NOEXCEPT
5574#else
5575    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5576#endif
5577{
5578    __swap_allocator(__a1, __a2,
5579      integral_constant<bool, _VSTD::allocator_traits<_Alloc>::propagate_on_container_swap::value>());
5580}
5581
5582template <typename _Alloc>
5583_LIBCPP_INLINE_VISIBILITY
5584void __swap_allocator(_Alloc & __a1, _Alloc & __a2, true_type)
5585#if _LIBCPP_STD_VER >= 14
5586    _NOEXCEPT
5587#else
5588    _NOEXCEPT_(__is_nothrow_swappable<_Alloc>::value)
5589#endif
5590{
5591    using _VSTD::swap;
5592    swap(__a1, __a2);
5593}
5594
5595template <typename _Alloc>
5596_LIBCPP_INLINE_VISIBILITY
5597void __swap_allocator(_Alloc &, _Alloc &, false_type) _NOEXCEPT {}
5598
5599template <typename _Alloc, typename _Traits=allocator_traits<_Alloc> >
5600struct __noexcept_move_assign_container : public integral_constant<bool,
5601    _Traits::propagate_on_container_move_assignment::value
5602#if _LIBCPP_STD_VER > 14
5603        || _Traits::is_always_equal::value
5604#else
5605        && is_nothrow_move_assignable<_Alloc>::value
5606#endif
5607    > {};
5608
5609_LIBCPP_END_NAMESPACE_STD
5610
5611#endif  // _LIBCPP_MEMORY
5612