1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP__HASH_TABLE
11#define _LIBCPP__HASH_TABLE
12
13#include <__config>
14#include <initializer_list>
15#include <memory>
16#include <iterator>
17#include <algorithm>
18#include <cmath>
19#include <utility>
20#include <type_traits>
21
22#include <__debug>
23
24#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
25#pragma GCC system_header
26#endif
27
28_LIBCPP_PUSH_MACROS
29#include <__undef_macros>
30
31
32_LIBCPP_BEGIN_NAMESPACE_STD
33
34template <class _Key, class _Tp>
35struct __hash_value_type;
36
37template <class _Tp>
38struct __is_hash_value_type_imp : false_type {};
39
40template <class _Key, class _Value>
41struct __is_hash_value_type_imp<__hash_value_type<_Key, _Value> > : true_type {};
42
43template <class ..._Args>
44struct __is_hash_value_type : false_type {};
45
46template <class _One>
47struct __is_hash_value_type<_One> : __is_hash_value_type_imp<typename __uncvref<_One>::type> {};
48
49_LIBCPP_FUNC_VIS
50size_t __next_prime(size_t __n);
51
52template <class _NodePtr>
53struct __hash_node_base
54{
55    typedef typename pointer_traits<_NodePtr>::element_type __node_type;
56    typedef __hash_node_base __first_node;
57    typedef typename __rebind_pointer<_NodePtr, __first_node>::type __node_base_pointer;
58    typedef _NodePtr __node_pointer;
59
60#if defined(_LIBCPP_ABI_FIX_UNORDERED_NODE_POINTER_UB)
61  typedef __node_base_pointer __next_pointer;
62#else
63  typedef typename conditional<
64      is_pointer<__node_pointer>::value,
65      __node_base_pointer,
66      __node_pointer>::type   __next_pointer;
67#endif
68
69    __next_pointer    __next_;
70
71    _LIBCPP_INLINE_VISIBILITY
72    __next_pointer __ptr() _NOEXCEPT {
73        return static_cast<__next_pointer>(
74            pointer_traits<__node_base_pointer>::pointer_to(*this));
75    }
76
77    _LIBCPP_INLINE_VISIBILITY
78    __node_pointer __upcast() _NOEXCEPT {
79        return static_cast<__node_pointer>(
80            pointer_traits<__node_base_pointer>::pointer_to(*this));
81    }
82
83    _LIBCPP_INLINE_VISIBILITY
84    size_t __hash() const _NOEXCEPT {
85        return static_cast<__node_type const&>(*this).__hash_;
86    }
87
88    _LIBCPP_INLINE_VISIBILITY __hash_node_base() _NOEXCEPT : __next_(nullptr) {}
89};
90
91template <class _Tp, class _VoidPtr>
92struct __hash_node
93    : public __hash_node_base
94             <
95                 typename __rebind_pointer<_VoidPtr, __hash_node<_Tp, _VoidPtr> >::type
96             >
97{
98    typedef _Tp __node_value_type;
99
100    size_t            __hash_;
101    __node_value_type __value_;
102};
103
104inline _LIBCPP_INLINE_VISIBILITY
105bool
106__is_hash_power2(size_t __bc)
107{
108    return __bc > 2 && !(__bc & (__bc - 1));
109}
110
111inline _LIBCPP_INLINE_VISIBILITY
112size_t
113__constrain_hash(size_t __h, size_t __bc)
114{
115    return !(__bc & (__bc - 1)) ? __h & (__bc - 1) :
116        (__h < __bc ? __h : __h % __bc);
117}
118
119inline _LIBCPP_INLINE_VISIBILITY
120size_t
121__next_hash_pow2(size_t __n)
122{
123    return __n < 2 ? __n : (size_t(1) << (numeric_limits<size_t>::digits - __libcpp_clz(__n-1)));
124}
125
126
127template <class _Tp, class _Hash, class _Equal, class _Alloc> class __hash_table;
128
129template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_iterator;
130template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
131template <class _NodePtr>      class _LIBCPP_TEMPLATE_VIS __hash_local_iterator;
132template <class _ConstNodePtr> class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
133template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
134template <class _HashIterator> class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
135
136template <class _Tp>
137struct __hash_key_value_types {
138  static_assert(!is_reference<_Tp>::value && !is_const<_Tp>::value, "");
139  typedef _Tp key_type;
140  typedef _Tp __node_value_type;
141  typedef _Tp __container_value_type;
142  static const bool __is_map = false;
143
144  _LIBCPP_INLINE_VISIBILITY
145  static key_type const& __get_key(_Tp const& __v) {
146    return __v;
147  }
148  _LIBCPP_INLINE_VISIBILITY
149  static __container_value_type const& __get_value(__node_value_type const& __v) {
150    return __v;
151  }
152  _LIBCPP_INLINE_VISIBILITY
153  static __container_value_type* __get_ptr(__node_value_type& __n) {
154    return _VSTD::addressof(__n);
155  }
156  _LIBCPP_INLINE_VISIBILITY
157  static __container_value_type&& __move(__node_value_type& __v) {
158    return _VSTD::move(__v);
159  }
160};
161
162template <class _Key, class _Tp>
163struct __hash_key_value_types<__hash_value_type<_Key, _Tp> > {
164  typedef _Key                                         key_type;
165  typedef _Tp                                          mapped_type;
166  typedef __hash_value_type<_Key, _Tp>                 __node_value_type;
167  typedef pair<const _Key, _Tp>                        __container_value_type;
168  typedef __container_value_type                       __map_value_type;
169  static const bool __is_map = true;
170
171  _LIBCPP_INLINE_VISIBILITY
172  static key_type const& __get_key(__container_value_type const& __v) {
173    return __v.first;
174  }
175
176  template <class _Up>
177  _LIBCPP_INLINE_VISIBILITY
178  static typename enable_if<__is_same_uncvref<_Up, __node_value_type>::value,
179      __container_value_type const&>::type
180  __get_value(_Up& __t) {
181    return __t.__get_value();
182  }
183
184  template <class _Up>
185  _LIBCPP_INLINE_VISIBILITY
186  static typename enable_if<__is_same_uncvref<_Up, __container_value_type>::value,
187      __container_value_type const&>::type
188  __get_value(_Up& __t) {
189    return __t;
190  }
191
192  _LIBCPP_INLINE_VISIBILITY
193  static __container_value_type* __get_ptr(__node_value_type& __n) {
194    return _VSTD::addressof(__n.__get_value());
195  }
196  _LIBCPP_INLINE_VISIBILITY
197  static pair<key_type&&, mapped_type&&> __move(__node_value_type& __v) {
198    return __v.__move();
199  }
200};
201
202template <class _Tp, class _AllocPtr, class _KVTypes = __hash_key_value_types<_Tp>,
203          bool = _KVTypes::__is_map>
204struct __hash_map_pointer_types {};
205
206template <class _Tp, class _AllocPtr, class _KVTypes>
207struct __hash_map_pointer_types<_Tp, _AllocPtr, _KVTypes, true> {
208  typedef typename _KVTypes::__map_value_type   _Mv;
209  typedef typename __rebind_pointer<_AllocPtr, _Mv>::type
210                                                       __map_value_type_pointer;
211  typedef typename __rebind_pointer<_AllocPtr, const _Mv>::type
212                                                 __const_map_value_type_pointer;
213};
214
215template <class _NodePtr, class _NodeT = typename pointer_traits<_NodePtr>::element_type>
216struct __hash_node_types;
217
218template <class _NodePtr, class _Tp, class _VoidPtr>
219struct __hash_node_types<_NodePtr, __hash_node<_Tp, _VoidPtr> >
220    : public __hash_key_value_types<_Tp>, __hash_map_pointer_types<_Tp, _VoidPtr>
221
222{
223  typedef __hash_key_value_types<_Tp>           __base;
224
225public:
226  typedef ptrdiff_t difference_type;
227  typedef size_t size_type;
228
229  typedef typename __rebind_pointer<_NodePtr, void>::type       __void_pointer;
230
231  typedef typename pointer_traits<_NodePtr>::element_type       __node_type;
232  typedef _NodePtr                                              __node_pointer;
233
234  typedef __hash_node_base<__node_pointer>                      __node_base_type;
235  typedef typename __rebind_pointer<_NodePtr, __node_base_type>::type
236                                                             __node_base_pointer;
237
238  typedef typename __node_base_type::__next_pointer          __next_pointer;
239
240  typedef _Tp                                                 __node_value_type;
241  typedef typename __rebind_pointer<_VoidPtr, __node_value_type>::type
242                                                      __node_value_type_pointer;
243  typedef typename __rebind_pointer<_VoidPtr, const __node_value_type>::type
244                                                __const_node_value_type_pointer;
245
246private:
247    static_assert(!is_const<__node_type>::value,
248                "_NodePtr should never be a pointer to const");
249    static_assert((is_same<typename pointer_traits<_VoidPtr>::element_type, void>::value),
250                  "_VoidPtr does not point to unqualified void type");
251    static_assert((is_same<typename __rebind_pointer<_VoidPtr, __node_type>::type,
252                          _NodePtr>::value), "_VoidPtr does not rebind to _NodePtr.");
253};
254
255template <class _HashIterator>
256struct __hash_node_types_from_iterator;
257template <class _NodePtr>
258struct __hash_node_types_from_iterator<__hash_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
259template <class _NodePtr>
260struct __hash_node_types_from_iterator<__hash_const_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
261template <class _NodePtr>
262struct __hash_node_types_from_iterator<__hash_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
263template <class _NodePtr>
264struct __hash_node_types_from_iterator<__hash_const_local_iterator<_NodePtr> > : __hash_node_types<_NodePtr> {};
265
266
267template <class _NodeValueTp, class _VoidPtr>
268struct __make_hash_node_types {
269  typedef __hash_node<_NodeValueTp, _VoidPtr> _NodeTp;
270  typedef typename __rebind_pointer<_VoidPtr, _NodeTp>::type _NodePtr;
271  typedef __hash_node_types<_NodePtr> type;
272};
273
274template <class _NodePtr>
275class _LIBCPP_TEMPLATE_VIS __hash_iterator
276{
277    typedef __hash_node_types<_NodePtr> _NodeTypes;
278    typedef _NodePtr                            __node_pointer;
279    typedef typename _NodeTypes::__next_pointer __next_pointer;
280
281    __next_pointer            __node_;
282
283public:
284    typedef forward_iterator_tag                           iterator_category;
285    typedef typename _NodeTypes::__node_value_type         value_type;
286    typedef typename _NodeTypes::difference_type           difference_type;
287    typedef value_type&                                    reference;
288    typedef typename _NodeTypes::__node_value_type_pointer pointer;
289
290    _LIBCPP_INLINE_VISIBILITY __hash_iterator() _NOEXCEPT : __node_(nullptr) {
291#if _LIBCPP_DEBUG_LEVEL == 2
292        __get_db()->__insert_i(this);
293#endif
294    }
295
296#if _LIBCPP_DEBUG_LEVEL == 2
297    _LIBCPP_INLINE_VISIBILITY
298    __hash_iterator(const __hash_iterator& __i)
299        : __node_(__i.__node_)
300    {
301        __get_db()->__iterator_copy(this, &__i);
302    }
303
304    _LIBCPP_INLINE_VISIBILITY
305    ~__hash_iterator()
306    {
307        __get_db()->__erase_i(this);
308    }
309
310    _LIBCPP_INLINE_VISIBILITY
311    __hash_iterator& operator=(const __hash_iterator& __i)
312    {
313        if (this != &__i)
314        {
315            __get_db()->__iterator_copy(this, &__i);
316            __node_ = __i.__node_;
317        }
318        return *this;
319    }
320#endif  // _LIBCPP_DEBUG_LEVEL == 2
321
322    _LIBCPP_INLINE_VISIBILITY
323    reference operator*() const {
324        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
325                             "Attempted to dereference a non-dereferenceable unordered container iterator");
326        return __node_->__upcast()->__value_;
327    }
328
329    _LIBCPP_INLINE_VISIBILITY
330    pointer operator->() const {
331        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
332                           "Attempted to dereference a non-dereferenceable unordered container iterator");
333        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
334    }
335
336    _LIBCPP_INLINE_VISIBILITY
337    __hash_iterator& operator++() {
338        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
339                       "Attempted to increment non-incrementable unordered container iterator");
340        __node_ = __node_->__next_;
341        return *this;
342    }
343
344    _LIBCPP_INLINE_VISIBILITY
345    __hash_iterator operator++(int)
346    {
347        __hash_iterator __t(*this);
348        ++(*this);
349        return __t;
350    }
351
352    friend _LIBCPP_INLINE_VISIBILITY
353    bool operator==(const __hash_iterator& __x, const __hash_iterator& __y)
354    {
355        return __x.__node_ == __y.__node_;
356    }
357    friend _LIBCPP_INLINE_VISIBILITY
358    bool operator!=(const __hash_iterator& __x, const __hash_iterator& __y)
359        {return !(__x == __y);}
360
361private:
362#if _LIBCPP_DEBUG_LEVEL == 2
363    _LIBCPP_INLINE_VISIBILITY
364    __hash_iterator(__next_pointer __node, const void* __c) _NOEXCEPT
365        : __node_(__node)
366        {
367            __get_db()->__insert_ic(this, __c);
368        }
369#else
370    _LIBCPP_INLINE_VISIBILITY
371    __hash_iterator(__next_pointer __node) _NOEXCEPT
372        : __node_(__node)
373        {}
374#endif
375    template <class, class, class, class> friend class __hash_table;
376    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_iterator;
377    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
378    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
379    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
380};
381
382template <class _NodePtr>
383class _LIBCPP_TEMPLATE_VIS __hash_const_iterator
384{
385    static_assert(!is_const<typename pointer_traits<_NodePtr>::element_type>::value, "");
386    typedef __hash_node_types<_NodePtr> _NodeTypes;
387    typedef _NodePtr                            __node_pointer;
388    typedef typename _NodeTypes::__next_pointer __next_pointer;
389
390    __next_pointer __node_;
391
392public:
393    typedef __hash_iterator<_NodePtr> __non_const_iterator;
394
395    typedef forward_iterator_tag                                 iterator_category;
396    typedef typename _NodeTypes::__node_value_type               value_type;
397    typedef typename _NodeTypes::difference_type                 difference_type;
398    typedef const value_type&                                    reference;
399    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
400
401
402    _LIBCPP_INLINE_VISIBILITY __hash_const_iterator() _NOEXCEPT : __node_(nullptr) {
403#if _LIBCPP_DEBUG_LEVEL == 2
404        __get_db()->__insert_i(this);
405#endif
406    }
407
408    _LIBCPP_INLINE_VISIBILITY
409    __hash_const_iterator(const __non_const_iterator& __x) _NOEXCEPT
410        : __node_(__x.__node_)
411    {
412#if _LIBCPP_DEBUG_LEVEL == 2
413        __get_db()->__iterator_copy(this, &__x);
414#endif
415    }
416
417#if _LIBCPP_DEBUG_LEVEL == 2
418    _LIBCPP_INLINE_VISIBILITY
419    __hash_const_iterator(const __hash_const_iterator& __i)
420        : __node_(__i.__node_)
421    {
422        __get_db()->__iterator_copy(this, &__i);
423    }
424
425    _LIBCPP_INLINE_VISIBILITY
426    ~__hash_const_iterator()
427    {
428        __get_db()->__erase_i(this);
429    }
430
431    _LIBCPP_INLINE_VISIBILITY
432    __hash_const_iterator& operator=(const __hash_const_iterator& __i)
433    {
434        if (this != &__i)
435        {
436            __get_db()->__iterator_copy(this, &__i);
437            __node_ = __i.__node_;
438        }
439        return *this;
440    }
441#endif  // _LIBCPP_DEBUG_LEVEL == 2
442
443    _LIBCPP_INLINE_VISIBILITY
444    reference operator*() const {
445        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
446                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
447        return __node_->__upcast()->__value_;
448    }
449    _LIBCPP_INLINE_VISIBILITY
450    pointer operator->() const {
451        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
452                           "Attempted to dereference a non-dereferenceable unordered container const_iterator");
453        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
454    }
455
456    _LIBCPP_INLINE_VISIBILITY
457    __hash_const_iterator& operator++() {
458        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
459                             "Attempted to increment non-incrementable unordered container const_iterator");
460        __node_ = __node_->__next_;
461        return *this;
462    }
463
464    _LIBCPP_INLINE_VISIBILITY
465    __hash_const_iterator operator++(int)
466    {
467        __hash_const_iterator __t(*this);
468        ++(*this);
469        return __t;
470    }
471
472    friend _LIBCPP_INLINE_VISIBILITY
473    bool operator==(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
474    {
475        return __x.__node_ == __y.__node_;
476    }
477    friend _LIBCPP_INLINE_VISIBILITY
478    bool operator!=(const __hash_const_iterator& __x, const __hash_const_iterator& __y)
479        {return !(__x == __y);}
480
481private:
482#if _LIBCPP_DEBUG_LEVEL == 2
483    _LIBCPP_INLINE_VISIBILITY
484    __hash_const_iterator(__next_pointer __node, const void* __c) _NOEXCEPT
485        : __node_(__node)
486        {
487            __get_db()->__insert_ic(this, __c);
488        }
489#else
490    _LIBCPP_INLINE_VISIBILITY
491    __hash_const_iterator(__next_pointer __node) _NOEXCEPT
492        : __node_(__node)
493        {}
494#endif
495    template <class, class, class, class> friend class __hash_table;
496    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
497    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
498    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
499};
500
501template <class _NodePtr>
502class _LIBCPP_TEMPLATE_VIS __hash_local_iterator
503{
504    typedef __hash_node_types<_NodePtr> _NodeTypes;
505    typedef _NodePtr                            __node_pointer;
506    typedef typename _NodeTypes::__next_pointer __next_pointer;
507
508    __next_pointer         __node_;
509    size_t                 __bucket_;
510    size_t                 __bucket_count_;
511
512public:
513    typedef forward_iterator_tag                                iterator_category;
514    typedef typename _NodeTypes::__node_value_type              value_type;
515    typedef typename _NodeTypes::difference_type                difference_type;
516    typedef value_type&                                         reference;
517    typedef typename _NodeTypes::__node_value_type_pointer      pointer;
518
519    _LIBCPP_INLINE_VISIBILITY __hash_local_iterator() _NOEXCEPT : __node_(nullptr) {
520#if _LIBCPP_DEBUG_LEVEL == 2
521        __get_db()->__insert_i(this);
522#endif
523    }
524
525#if _LIBCPP_DEBUG_LEVEL == 2
526    _LIBCPP_INLINE_VISIBILITY
527    __hash_local_iterator(const __hash_local_iterator& __i)
528        : __node_(__i.__node_),
529          __bucket_(__i.__bucket_),
530          __bucket_count_(__i.__bucket_count_)
531    {
532        __get_db()->__iterator_copy(this, &__i);
533    }
534
535    _LIBCPP_INLINE_VISIBILITY
536    ~__hash_local_iterator()
537    {
538        __get_db()->__erase_i(this);
539    }
540
541    _LIBCPP_INLINE_VISIBILITY
542    __hash_local_iterator& operator=(const __hash_local_iterator& __i)
543    {
544        if (this != &__i)
545        {
546            __get_db()->__iterator_copy(this, &__i);
547            __node_ = __i.__node_;
548            __bucket_ = __i.__bucket_;
549            __bucket_count_ = __i.__bucket_count_;
550        }
551        return *this;
552    }
553#endif  // _LIBCPP_DEBUG_LEVEL == 2
554
555    _LIBCPP_INLINE_VISIBILITY
556    reference operator*() const {
557        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
558                           "Attempted to dereference a non-dereferenceable unordered container local_iterator");
559        return __node_->__upcast()->__value_;
560    }
561
562    _LIBCPP_INLINE_VISIBILITY
563    pointer operator->() const {
564        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
565                             "Attempted to dereference a non-dereferenceable unordered container local_iterator");
566        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
567    }
568
569    _LIBCPP_INLINE_VISIBILITY
570    __hash_local_iterator& operator++() {
571        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
572                       "Attempted to increment non-incrementable unordered container local_iterator");
573        __node_ = __node_->__next_;
574        if (__node_ != nullptr && __constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
575            __node_ = nullptr;
576        return *this;
577    }
578
579    _LIBCPP_INLINE_VISIBILITY
580    __hash_local_iterator operator++(int)
581    {
582        __hash_local_iterator __t(*this);
583        ++(*this);
584        return __t;
585    }
586
587    friend _LIBCPP_INLINE_VISIBILITY
588    bool operator==(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
589    {
590        return __x.__node_ == __y.__node_;
591    }
592    friend _LIBCPP_INLINE_VISIBILITY
593    bool operator!=(const __hash_local_iterator& __x, const __hash_local_iterator& __y)
594        {return !(__x == __y);}
595
596private:
597#if _LIBCPP_DEBUG_LEVEL == 2
598    _LIBCPP_INLINE_VISIBILITY
599    __hash_local_iterator(__next_pointer __node, size_t __bucket,
600                          size_t __bucket_count, const void* __c) _NOEXCEPT
601        : __node_(__node),
602          __bucket_(__bucket),
603          __bucket_count_(__bucket_count)
604        {
605            __get_db()->__insert_ic(this, __c);
606            if (__node_ != nullptr)
607                __node_ = __node_->__next_;
608        }
609#else
610    _LIBCPP_INLINE_VISIBILITY
611    __hash_local_iterator(__next_pointer __node, size_t __bucket,
612                          size_t __bucket_count) _NOEXCEPT
613        : __node_(__node),
614          __bucket_(__bucket),
615          __bucket_count_(__bucket_count)
616        {
617            if (__node_ != nullptr)
618                __node_ = __node_->__next_;
619        }
620#endif
621    template <class, class, class, class> friend class __hash_table;
622    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator;
623    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_iterator;
624};
625
626template <class _ConstNodePtr>
627class _LIBCPP_TEMPLATE_VIS __hash_const_local_iterator
628{
629    typedef __hash_node_types<_ConstNodePtr> _NodeTypes;
630    typedef _ConstNodePtr                       __node_pointer;
631    typedef typename _NodeTypes::__next_pointer __next_pointer;
632
633    __next_pointer         __node_;
634    size_t                 __bucket_;
635    size_t                 __bucket_count_;
636
637    typedef pointer_traits<__node_pointer>          __pointer_traits;
638    typedef typename __pointer_traits::element_type __node;
639    typedef typename remove_const<__node>::type     __non_const_node;
640    typedef typename __rebind_pointer<__node_pointer, __non_const_node>::type
641        __non_const_node_pointer;
642public:
643    typedef __hash_local_iterator<__non_const_node_pointer>
644                                                    __non_const_iterator;
645
646    typedef forward_iterator_tag                                 iterator_category;
647    typedef typename _NodeTypes::__node_value_type               value_type;
648    typedef typename _NodeTypes::difference_type                 difference_type;
649    typedef const value_type&                                    reference;
650    typedef typename _NodeTypes::__const_node_value_type_pointer pointer;
651
652
653    _LIBCPP_INLINE_VISIBILITY __hash_const_local_iterator() _NOEXCEPT : __node_(nullptr) {
654#if _LIBCPP_DEBUG_LEVEL == 2
655        __get_db()->__insert_i(this);
656#endif
657    }
658
659    _LIBCPP_INLINE_VISIBILITY
660    __hash_const_local_iterator(const __non_const_iterator& __x) _NOEXCEPT
661        : __node_(__x.__node_),
662          __bucket_(__x.__bucket_),
663          __bucket_count_(__x.__bucket_count_)
664    {
665#if _LIBCPP_DEBUG_LEVEL == 2
666        __get_db()->__iterator_copy(this, &__x);
667#endif
668    }
669
670#if _LIBCPP_DEBUG_LEVEL == 2
671    _LIBCPP_INLINE_VISIBILITY
672    __hash_const_local_iterator(const __hash_const_local_iterator& __i)
673        : __node_(__i.__node_),
674          __bucket_(__i.__bucket_),
675          __bucket_count_(__i.__bucket_count_)
676    {
677        __get_db()->__iterator_copy(this, &__i);
678    }
679
680    _LIBCPP_INLINE_VISIBILITY
681    ~__hash_const_local_iterator()
682    {
683        __get_db()->__erase_i(this);
684    }
685
686    _LIBCPP_INLINE_VISIBILITY
687    __hash_const_local_iterator& operator=(const __hash_const_local_iterator& __i)
688    {
689        if (this != &__i)
690        {
691            __get_db()->__iterator_copy(this, &__i);
692            __node_ = __i.__node_;
693            __bucket_ = __i.__bucket_;
694            __bucket_count_ = __i.__bucket_count_;
695        }
696        return *this;
697    }
698#endif  // _LIBCPP_DEBUG_LEVEL == 2
699
700    _LIBCPP_INLINE_VISIBILITY
701    reference operator*() const {
702        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
703                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
704        return __node_->__upcast()->__value_;
705    }
706
707    _LIBCPP_INLINE_VISIBILITY
708    pointer operator->() const {
709        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
710                           "Attempted to dereference a non-dereferenceable unordered container const_local_iterator");
711        return pointer_traits<pointer>::pointer_to(__node_->__upcast()->__value_);
712    }
713
714    _LIBCPP_INLINE_VISIBILITY
715    __hash_const_local_iterator& operator++() {
716        _LIBCPP_DEBUG_ASSERT(__get_const_db()->__dereferenceable(this),
717                       "Attempted to increment non-incrementable unordered container const_local_iterator");
718        __node_ = __node_->__next_;
719        if (__node_ != nullptr && __constrain_hash(__node_->__hash(), __bucket_count_) != __bucket_)
720            __node_ = nullptr;
721        return *this;
722    }
723
724    _LIBCPP_INLINE_VISIBILITY
725    __hash_const_local_iterator operator++(int)
726    {
727        __hash_const_local_iterator __t(*this);
728        ++(*this);
729        return __t;
730    }
731
732    friend _LIBCPP_INLINE_VISIBILITY
733    bool operator==(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
734    {
735        return __x.__node_ == __y.__node_;
736    }
737    friend _LIBCPP_INLINE_VISIBILITY
738    bool operator!=(const __hash_const_local_iterator& __x, const __hash_const_local_iterator& __y)
739        {return !(__x == __y);}
740
741private:
742#if _LIBCPP_DEBUG_LEVEL == 2
743    _LIBCPP_INLINE_VISIBILITY
744    __hash_const_local_iterator(__next_pointer __node, size_t __bucket,
745                                size_t __bucket_count, const void* __c) _NOEXCEPT
746        : __node_(__node),
747          __bucket_(__bucket),
748          __bucket_count_(__bucket_count)
749        {
750            __get_db()->__insert_ic(this, __c);
751            if (__node_ != nullptr)
752                __node_ = __node_->__next_;
753        }
754#else
755    _LIBCPP_INLINE_VISIBILITY
756    __hash_const_local_iterator(__next_pointer __node, size_t __bucket,
757                                size_t __bucket_count) _NOEXCEPT
758        : __node_(__node),
759          __bucket_(__bucket),
760          __bucket_count_(__bucket_count)
761        {
762            if (__node_ != nullptr)
763                __node_ = __node_->__next_;
764        }
765#endif
766    template <class, class, class, class> friend class __hash_table;
767    template <class> friend class _LIBCPP_TEMPLATE_VIS __hash_map_const_iterator;
768};
769
770template <class _Alloc>
771class __bucket_list_deallocator
772{
773    typedef _Alloc                                          allocator_type;
774    typedef allocator_traits<allocator_type>                __alloc_traits;
775    typedef typename __alloc_traits::size_type              size_type;
776
777    __compressed_pair<size_type, allocator_type> __data_;
778public:
779    typedef typename __alloc_traits::pointer pointer;
780
781    _LIBCPP_INLINE_VISIBILITY
782    __bucket_list_deallocator()
783        _NOEXCEPT_(is_nothrow_default_constructible<allocator_type>::value)
784        : __data_(0, __default_init_tag()) {}
785
786    _LIBCPP_INLINE_VISIBILITY
787    __bucket_list_deallocator(const allocator_type& __a, size_type __size)
788        _NOEXCEPT_(is_nothrow_copy_constructible<allocator_type>::value)
789        : __data_(__size, __a) {}
790
791    _LIBCPP_INLINE_VISIBILITY
792    __bucket_list_deallocator(__bucket_list_deallocator&& __x)
793        _NOEXCEPT_(is_nothrow_move_constructible<allocator_type>::value)
794        : __data_(_VSTD::move(__x.__data_))
795    {
796        __x.size() = 0;
797    }
798
799    _LIBCPP_INLINE_VISIBILITY
800    size_type& size() _NOEXCEPT {return __data_.first();}
801    _LIBCPP_INLINE_VISIBILITY
802    size_type  size() const _NOEXCEPT {return __data_.first();}
803
804    _LIBCPP_INLINE_VISIBILITY
805    allocator_type& __alloc() _NOEXCEPT {return __data_.second();}
806    _LIBCPP_INLINE_VISIBILITY
807    const allocator_type& __alloc() const _NOEXCEPT {return __data_.second();}
808
809    _LIBCPP_INLINE_VISIBILITY
810    void operator()(pointer __p) _NOEXCEPT
811    {
812        __alloc_traits::deallocate(__alloc(), __p, size());
813    }
814};
815
816template <class _Alloc> class __hash_map_node_destructor;
817
818template <class _Alloc>
819class __hash_node_destructor
820{
821    typedef _Alloc                                          allocator_type;
822    typedef allocator_traits<allocator_type>                __alloc_traits;
823
824public:
825    typedef typename __alloc_traits::pointer                pointer;
826private:
827    typedef __hash_node_types<pointer> _NodeTypes;
828
829    allocator_type& __na_;
830
831public:
832    bool __value_constructed;
833
834    __hash_node_destructor(__hash_node_destructor const&) = default;
835    __hash_node_destructor& operator=(const __hash_node_destructor&) = delete;
836
837
838    _LIBCPP_INLINE_VISIBILITY
839    explicit __hash_node_destructor(allocator_type& __na,
840                                    bool __constructed = false) _NOEXCEPT
841        : __na_(__na),
842          __value_constructed(__constructed)
843        {}
844
845    _LIBCPP_INLINE_VISIBILITY
846    void operator()(pointer __p) _NOEXCEPT
847    {
848        if (__value_constructed)
849            __alloc_traits::destroy(__na_, _NodeTypes::__get_ptr(__p->__value_));
850        if (__p)
851            __alloc_traits::deallocate(__na_, __p, 1);
852    }
853
854    template <class> friend class __hash_map_node_destructor;
855};
856
857#if _LIBCPP_STD_VER > 14
858template <class _NodeType, class _Alloc>
859struct __generic_container_node_destructor;
860
861template <class _Tp, class _VoidPtr, class _Alloc>
862struct __generic_container_node_destructor<__hash_node<_Tp, _VoidPtr>, _Alloc>
863    : __hash_node_destructor<_Alloc>
864{
865    using __hash_node_destructor<_Alloc>::__hash_node_destructor;
866};
867#endif
868
869template <class _Key, class _Hash, class _Equal>
870struct __enforce_unordered_container_requirements {
871#ifndef _LIBCPP_CXX03_LANG
872    static_assert(__check_hash_requirements<_Key, _Hash>::value,
873    "the specified hash does not meet the Hash requirements");
874    static_assert(is_copy_constructible<_Equal>::value,
875    "the specified comparator is required to be copy constructible");
876#endif
877    typedef int type;
878};
879
880template <class _Key, class _Hash, class _Equal>
881#ifndef _LIBCPP_CXX03_LANG
882    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Equal const&, _Key const&, _Key const&>::value,
883    "the specified comparator type does not provide a viable const call operator")
884    _LIBCPP_DIAGNOSE_WARNING(!__invokable<_Hash const&, _Key const&>::value,
885    "the specified hash functor does not provide a viable const call operator")
886#endif
887typename __enforce_unordered_container_requirements<_Key, _Hash, _Equal>::type
888__diagnose_unordered_container_requirements(int);
889
890// This dummy overload is used so that the compiler won't emit a spurious
891// "no matching function for call to __diagnose_unordered_xxx" diagnostic
892// when the overload above causes a hard error.
893template <class _Key, class _Hash, class _Equal>
894int __diagnose_unordered_container_requirements(void*);
895
896template <class _Tp, class _Hash, class _Equal, class _Alloc>
897class __hash_table
898{
899public:
900    typedef _Tp    value_type;
901    typedef _Hash  hasher;
902    typedef _Equal key_equal;
903    typedef _Alloc allocator_type;
904
905private:
906    typedef allocator_traits<allocator_type> __alloc_traits;
907    typedef typename
908      __make_hash_node_types<value_type, typename __alloc_traits::void_pointer>::type
909                                                                     _NodeTypes;
910public:
911
912    typedef typename _NodeTypes::__node_value_type           __node_value_type;
913    typedef typename _NodeTypes::__container_value_type      __container_value_type;
914    typedef typename _NodeTypes::key_type                    key_type;
915    typedef value_type&                              reference;
916    typedef const value_type&                        const_reference;
917    typedef typename __alloc_traits::pointer         pointer;
918    typedef typename __alloc_traits::const_pointer   const_pointer;
919#ifndef _LIBCPP_ABI_FIX_UNORDERED_CONTAINER_SIZE_TYPE
920    typedef typename __alloc_traits::size_type       size_type;
921#else
922    typedef typename _NodeTypes::size_type           size_type;
923#endif
924    typedef typename _NodeTypes::difference_type     difference_type;
925public:
926    // Create __node
927
928    typedef typename _NodeTypes::__node_type __node;
929    typedef typename __rebind_alloc_helper<__alloc_traits, __node>::type __node_allocator;
930    typedef allocator_traits<__node_allocator>       __node_traits;
931    typedef typename _NodeTypes::__void_pointer      __void_pointer;
932    typedef typename _NodeTypes::__node_pointer      __node_pointer;
933    typedef typename _NodeTypes::__node_pointer      __node_const_pointer;
934    typedef typename _NodeTypes::__node_base_type    __first_node;
935    typedef typename _NodeTypes::__node_base_pointer __node_base_pointer;
936    typedef typename _NodeTypes::__next_pointer      __next_pointer;
937
938private:
939    // check for sane allocator pointer rebinding semantics. Rebinding the
940    // allocator for a new pointer type should be exactly the same as rebinding
941    // the pointer using 'pointer_traits'.
942    static_assert((is_same<__node_pointer, typename __node_traits::pointer>::value),
943                  "Allocator does not rebind pointers in a sane manner.");
944    typedef typename __rebind_alloc_helper<__node_traits, __first_node>::type
945        __node_base_allocator;
946    typedef allocator_traits<__node_base_allocator> __node_base_traits;
947    static_assert((is_same<__node_base_pointer, typename __node_base_traits::pointer>::value),
948                 "Allocator does not rebind pointers in a sane manner.");
949
950private:
951
952    typedef typename __rebind_alloc_helper<__node_traits, __next_pointer>::type __pointer_allocator;
953    typedef __bucket_list_deallocator<__pointer_allocator> __bucket_list_deleter;
954    typedef unique_ptr<__next_pointer[], __bucket_list_deleter> __bucket_list;
955    typedef allocator_traits<__pointer_allocator>          __pointer_alloc_traits;
956    typedef typename __bucket_list_deleter::pointer       __node_pointer_pointer;
957
958    // --- Member data begin ---
959    __bucket_list                                         __bucket_list_;
960    __compressed_pair<__first_node, __node_allocator>     __p1_;
961    __compressed_pair<size_type, hasher>                  __p2_;
962    __compressed_pair<float, key_equal>                   __p3_;
963    // --- Member data end ---
964
965    _LIBCPP_INLINE_VISIBILITY
966    size_type& size() _NOEXCEPT {return __p2_.first();}
967public:
968    _LIBCPP_INLINE_VISIBILITY
969    size_type  size() const _NOEXCEPT {return __p2_.first();}
970
971    _LIBCPP_INLINE_VISIBILITY
972    hasher& hash_function() _NOEXCEPT {return __p2_.second();}
973    _LIBCPP_INLINE_VISIBILITY
974    const hasher& hash_function() const _NOEXCEPT {return __p2_.second();}
975
976    _LIBCPP_INLINE_VISIBILITY
977    float& max_load_factor() _NOEXCEPT {return __p3_.first();}
978    _LIBCPP_INLINE_VISIBILITY
979    float  max_load_factor() const _NOEXCEPT {return __p3_.first();}
980
981    _LIBCPP_INLINE_VISIBILITY
982    key_equal& key_eq() _NOEXCEPT {return __p3_.second();}
983    _LIBCPP_INLINE_VISIBILITY
984    const key_equal& key_eq() const _NOEXCEPT {return __p3_.second();}
985
986    _LIBCPP_INLINE_VISIBILITY
987    __node_allocator& __node_alloc() _NOEXCEPT {return __p1_.second();}
988    _LIBCPP_INLINE_VISIBILITY
989    const __node_allocator& __node_alloc() const _NOEXCEPT
990        {return __p1_.second();}
991
992public:
993    typedef __hash_iterator<__node_pointer>                   iterator;
994    typedef __hash_const_iterator<__node_pointer>             const_iterator;
995    typedef __hash_local_iterator<__node_pointer>             local_iterator;
996    typedef __hash_const_local_iterator<__node_pointer>       const_local_iterator;
997
998    _LIBCPP_INLINE_VISIBILITY
999    __hash_table()
1000        _NOEXCEPT_(
1001            is_nothrow_default_constructible<__bucket_list>::value &&
1002            is_nothrow_default_constructible<__first_node>::value &&
1003            is_nothrow_default_constructible<__node_allocator>::value &&
1004            is_nothrow_default_constructible<hasher>::value &&
1005            is_nothrow_default_constructible<key_equal>::value);
1006    _LIBCPP_INLINE_VISIBILITY
1007    __hash_table(const hasher& __hf, const key_equal& __eql);
1008    __hash_table(const hasher& __hf, const key_equal& __eql,
1009                 const allocator_type& __a);
1010    explicit __hash_table(const allocator_type& __a);
1011    __hash_table(const __hash_table& __u);
1012    __hash_table(const __hash_table& __u, const allocator_type& __a);
1013    __hash_table(__hash_table&& __u)
1014        _NOEXCEPT_(
1015            is_nothrow_move_constructible<__bucket_list>::value &&
1016            is_nothrow_move_constructible<__first_node>::value &&
1017            is_nothrow_move_constructible<__node_allocator>::value &&
1018            is_nothrow_move_constructible<hasher>::value &&
1019            is_nothrow_move_constructible<key_equal>::value);
1020    __hash_table(__hash_table&& __u, const allocator_type& __a);
1021    ~__hash_table();
1022
1023    __hash_table& operator=(const __hash_table& __u);
1024    _LIBCPP_INLINE_VISIBILITY
1025    __hash_table& operator=(__hash_table&& __u)
1026        _NOEXCEPT_(
1027            __node_traits::propagate_on_container_move_assignment::value &&
1028            is_nothrow_move_assignable<__node_allocator>::value &&
1029            is_nothrow_move_assignable<hasher>::value &&
1030            is_nothrow_move_assignable<key_equal>::value);
1031    template <class _InputIterator>
1032        void __assign_unique(_InputIterator __first, _InputIterator __last);
1033    template <class _InputIterator>
1034        void __assign_multi(_InputIterator __first, _InputIterator __last);
1035
1036    _LIBCPP_INLINE_VISIBILITY
1037    size_type max_size() const _NOEXCEPT
1038    {
1039        return _VSTD::min<size_type>(
1040            __node_traits::max_size(__node_alloc()),
1041            numeric_limits<difference_type >::max()
1042        );
1043    }
1044
1045private:
1046    _LIBCPP_INLINE_VISIBILITY
1047    __next_pointer __node_insert_multi_prepare(size_t __cp_hash,
1048                                               value_type& __cp_val);
1049    _LIBCPP_INLINE_VISIBILITY
1050    void __node_insert_multi_perform(__node_pointer __cp,
1051                                     __next_pointer __pn) _NOEXCEPT;
1052
1053    _LIBCPP_INLINE_VISIBILITY
1054    __next_pointer __node_insert_unique_prepare(size_t __nd_hash,
1055                                                value_type& __nd_val);
1056    _LIBCPP_INLINE_VISIBILITY
1057    void __node_insert_unique_perform(__node_pointer __ptr) _NOEXCEPT;
1058
1059public:
1060    _LIBCPP_INLINE_VISIBILITY
1061    pair<iterator, bool> __node_insert_unique(__node_pointer __nd);
1062    _LIBCPP_INLINE_VISIBILITY
1063    iterator             __node_insert_multi(__node_pointer __nd);
1064    _LIBCPP_INLINE_VISIBILITY
1065    iterator             __node_insert_multi(const_iterator __p,
1066                                             __node_pointer __nd);
1067
1068    template <class _Key, class ..._Args>
1069    _LIBCPP_INLINE_VISIBILITY
1070    pair<iterator, bool> __emplace_unique_key_args(_Key const& __k, _Args&&... __args);
1071
1072    template <class... _Args>
1073    _LIBCPP_INLINE_VISIBILITY
1074    pair<iterator, bool> __emplace_unique_impl(_Args&&... __args);
1075
1076    template <class _Pp>
1077    _LIBCPP_INLINE_VISIBILITY
1078    pair<iterator, bool> __emplace_unique(_Pp&& __x) {
1079      return __emplace_unique_extract_key(_VSTD::forward<_Pp>(__x),
1080                                          __can_extract_key<_Pp, key_type>());
1081    }
1082
1083    template <class _First, class _Second>
1084    _LIBCPP_INLINE_VISIBILITY
1085    typename enable_if<
1086        __can_extract_map_key<_First, key_type, __container_value_type>::value,
1087        pair<iterator, bool>
1088    >::type __emplace_unique(_First&& __f, _Second&& __s) {
1089        return __emplace_unique_key_args(__f, _VSTD::forward<_First>(__f),
1090                                              _VSTD::forward<_Second>(__s));
1091    }
1092
1093    template <class... _Args>
1094    _LIBCPP_INLINE_VISIBILITY
1095    pair<iterator, bool> __emplace_unique(_Args&&... __args) {
1096      return __emplace_unique_impl(_VSTD::forward<_Args>(__args)...);
1097    }
1098
1099    template <class _Pp>
1100    _LIBCPP_INLINE_VISIBILITY
1101    pair<iterator, bool>
1102    __emplace_unique_extract_key(_Pp&& __x, __extract_key_fail_tag) {
1103      return __emplace_unique_impl(_VSTD::forward<_Pp>(__x));
1104    }
1105    template <class _Pp>
1106    _LIBCPP_INLINE_VISIBILITY
1107    pair<iterator, bool>
1108    __emplace_unique_extract_key(_Pp&& __x, __extract_key_self_tag) {
1109      return __emplace_unique_key_args(__x, _VSTD::forward<_Pp>(__x));
1110    }
1111    template <class _Pp>
1112    _LIBCPP_INLINE_VISIBILITY
1113    pair<iterator, bool>
1114    __emplace_unique_extract_key(_Pp&& __x, __extract_key_first_tag) {
1115      return __emplace_unique_key_args(__x.first, _VSTD::forward<_Pp>(__x));
1116    }
1117
1118    template <class... _Args>
1119    _LIBCPP_INLINE_VISIBILITY
1120    iterator __emplace_multi(_Args&&... __args);
1121    template <class... _Args>
1122    _LIBCPP_INLINE_VISIBILITY
1123    iterator __emplace_hint_multi(const_iterator __p, _Args&&... __args);
1124
1125
1126    _LIBCPP_INLINE_VISIBILITY
1127    pair<iterator, bool>
1128    __insert_unique(__container_value_type&& __x) {
1129      return __emplace_unique_key_args(_NodeTypes::__get_key(__x), _VSTD::move(__x));
1130    }
1131
1132    template <class _Pp, class = typename enable_if<
1133            !__is_same_uncvref<_Pp, __container_value_type>::value
1134        >::type>
1135    _LIBCPP_INLINE_VISIBILITY
1136    pair<iterator, bool> __insert_unique(_Pp&& __x) {
1137      return __emplace_unique(_VSTD::forward<_Pp>(__x));
1138    }
1139
1140    template <class _Pp>
1141    _LIBCPP_INLINE_VISIBILITY
1142    iterator __insert_multi(_Pp&& __x) {
1143      return __emplace_multi(_VSTD::forward<_Pp>(__x));
1144    }
1145
1146    template <class _Pp>
1147    _LIBCPP_INLINE_VISIBILITY
1148    iterator __insert_multi(const_iterator __p, _Pp&& __x) {
1149        return __emplace_hint_multi(__p, _VSTD::forward<_Pp>(__x));
1150    }
1151
1152    _LIBCPP_INLINE_VISIBILITY
1153    pair<iterator, bool> __insert_unique(const __container_value_type& __x) {
1154        return __emplace_unique_key_args(_NodeTypes::__get_key(__x), __x);
1155    }
1156
1157#if _LIBCPP_STD_VER > 14
1158    template <class _NodeHandle, class _InsertReturnType>
1159    _LIBCPP_INLINE_VISIBILITY
1160    _InsertReturnType __node_handle_insert_unique(_NodeHandle&& __nh);
1161    template <class _NodeHandle>
1162    _LIBCPP_INLINE_VISIBILITY
1163    iterator __node_handle_insert_unique(const_iterator __hint,
1164                                         _NodeHandle&& __nh);
1165    template <class _Table>
1166    _LIBCPP_INLINE_VISIBILITY
1167    void __node_handle_merge_unique(_Table& __source);
1168
1169    template <class _NodeHandle>
1170    _LIBCPP_INLINE_VISIBILITY
1171    iterator __node_handle_insert_multi(_NodeHandle&& __nh);
1172    template <class _NodeHandle>
1173    _LIBCPP_INLINE_VISIBILITY
1174    iterator __node_handle_insert_multi(const_iterator __hint, _NodeHandle&& __nh);
1175    template <class _Table>
1176    _LIBCPP_INLINE_VISIBILITY
1177    void __node_handle_merge_multi(_Table& __source);
1178
1179    template <class _NodeHandle>
1180    _LIBCPP_INLINE_VISIBILITY
1181    _NodeHandle __node_handle_extract(key_type const& __key);
1182    template <class _NodeHandle>
1183    _LIBCPP_INLINE_VISIBILITY
1184    _NodeHandle __node_handle_extract(const_iterator __it);
1185#endif
1186
1187    void clear() _NOEXCEPT;
1188    void rehash(size_type __n);
1189    _LIBCPP_INLINE_VISIBILITY void reserve(size_type __n)
1190        {rehash(static_cast<size_type>(ceil(__n / max_load_factor())));}
1191
1192    _LIBCPP_INLINE_VISIBILITY
1193    size_type bucket_count() const _NOEXCEPT
1194    {
1195        return __bucket_list_.get_deleter().size();
1196    }
1197
1198    _LIBCPP_INLINE_VISIBILITY
1199    iterator       begin() _NOEXCEPT;
1200    _LIBCPP_INLINE_VISIBILITY
1201    iterator       end() _NOEXCEPT;
1202    _LIBCPP_INLINE_VISIBILITY
1203    const_iterator begin() const _NOEXCEPT;
1204    _LIBCPP_INLINE_VISIBILITY
1205    const_iterator end() const _NOEXCEPT;
1206
1207    template <class _Key>
1208        _LIBCPP_INLINE_VISIBILITY
1209        size_type bucket(const _Key& __k) const
1210        {
1211            _LIBCPP_ASSERT(bucket_count() > 0,
1212                "unordered container::bucket(key) called when bucket_count() == 0");
1213            return __constrain_hash(hash_function()(__k), bucket_count());
1214        }
1215
1216    template <class _Key>
1217        iterator       find(const _Key& __x);
1218    template <class _Key>
1219        const_iterator find(const _Key& __x) const;
1220
1221    typedef __hash_node_destructor<__node_allocator> _Dp;
1222    typedef unique_ptr<__node, _Dp> __node_holder;
1223
1224    iterator erase(const_iterator __p);
1225    iterator erase(const_iterator __first, const_iterator __last);
1226    template <class _Key>
1227        size_type __erase_unique(const _Key& __k);
1228    template <class _Key>
1229        size_type __erase_multi(const _Key& __k);
1230    __node_holder remove(const_iterator __p) _NOEXCEPT;
1231
1232    template <class _Key>
1233        _LIBCPP_INLINE_VISIBILITY
1234        size_type __count_unique(const _Key& __k) const;
1235    template <class _Key>
1236        size_type __count_multi(const _Key& __k) const;
1237
1238    template <class _Key>
1239        pair<iterator, iterator>
1240        __equal_range_unique(const _Key& __k);
1241    template <class _Key>
1242        pair<const_iterator, const_iterator>
1243        __equal_range_unique(const _Key& __k) const;
1244
1245    template <class _Key>
1246        pair<iterator, iterator>
1247        __equal_range_multi(const _Key& __k);
1248    template <class _Key>
1249        pair<const_iterator, const_iterator>
1250        __equal_range_multi(const _Key& __k) const;
1251
1252    void swap(__hash_table& __u)
1253#if _LIBCPP_STD_VER <= 11
1254        _NOEXCEPT_(
1255            __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
1256            && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
1257                  || __is_nothrow_swappable<__pointer_allocator>::value)
1258            && (!__node_traits::propagate_on_container_swap::value
1259                  || __is_nothrow_swappable<__node_allocator>::value)
1260            );
1261#else
1262     _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value);
1263#endif
1264
1265    _LIBCPP_INLINE_VISIBILITY
1266    size_type max_bucket_count() const _NOEXCEPT
1267        {return max_size(); }
1268    size_type bucket_size(size_type __n) const;
1269    _LIBCPP_INLINE_VISIBILITY float load_factor() const _NOEXCEPT
1270    {
1271        size_type __bc = bucket_count();
1272        return __bc != 0 ? (float)size() / __bc : 0.f;
1273    }
1274    _LIBCPP_INLINE_VISIBILITY void max_load_factor(float __mlf) _NOEXCEPT
1275    {
1276        _LIBCPP_ASSERT(__mlf > 0,
1277            "unordered container::max_load_factor(lf) called with lf <= 0");
1278        max_load_factor() = _VSTD::max(__mlf, load_factor());
1279    }
1280
1281    _LIBCPP_INLINE_VISIBILITY
1282    local_iterator
1283    begin(size_type __n)
1284    {
1285        _LIBCPP_ASSERT(__n < bucket_count(),
1286            "unordered container::begin(n) called with n >= bucket_count()");
1287#if _LIBCPP_DEBUG_LEVEL == 2
1288        return local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
1289#else
1290        return local_iterator(__bucket_list_[__n], __n, bucket_count());
1291#endif
1292    }
1293
1294    _LIBCPP_INLINE_VISIBILITY
1295    local_iterator
1296    end(size_type __n)
1297    {
1298        _LIBCPP_ASSERT(__n < bucket_count(),
1299            "unordered container::end(n) called with n >= bucket_count()");
1300#if _LIBCPP_DEBUG_LEVEL == 2
1301        return local_iterator(nullptr, __n, bucket_count(), this);
1302#else
1303        return local_iterator(nullptr, __n, bucket_count());
1304#endif
1305    }
1306
1307    _LIBCPP_INLINE_VISIBILITY
1308    const_local_iterator
1309    cbegin(size_type __n) const
1310    {
1311        _LIBCPP_ASSERT(__n < bucket_count(),
1312            "unordered container::cbegin(n) called with n >= bucket_count()");
1313#if _LIBCPP_DEBUG_LEVEL == 2
1314        return const_local_iterator(__bucket_list_[__n], __n, bucket_count(), this);
1315#else
1316        return const_local_iterator(__bucket_list_[__n], __n, bucket_count());
1317#endif
1318    }
1319
1320    _LIBCPP_INLINE_VISIBILITY
1321    const_local_iterator
1322    cend(size_type __n) const
1323    {
1324        _LIBCPP_ASSERT(__n < bucket_count(),
1325            "unordered container::cend(n) called with n >= bucket_count()");
1326#if _LIBCPP_DEBUG_LEVEL == 2
1327        return const_local_iterator(nullptr, __n, bucket_count(), this);
1328#else
1329        return const_local_iterator(nullptr, __n, bucket_count());
1330#endif
1331    }
1332
1333#if _LIBCPP_DEBUG_LEVEL == 2
1334
1335    bool __dereferenceable(const const_iterator* __i) const;
1336    bool __decrementable(const const_iterator* __i) const;
1337    bool __addable(const const_iterator* __i, ptrdiff_t __n) const;
1338    bool __subscriptable(const const_iterator* __i, ptrdiff_t __n) const;
1339
1340#endif  // _LIBCPP_DEBUG_LEVEL == 2
1341
1342private:
1343    void __rehash(size_type __n);
1344
1345    template <class ..._Args>
1346    __node_holder __construct_node(_Args&& ...__args);
1347
1348    template <class _First, class ..._Rest>
1349    __node_holder __construct_node_hash(size_t __hash, _First&& __f, _Rest&&... __rest);
1350
1351
1352    _LIBCPP_INLINE_VISIBILITY
1353    void __copy_assign_alloc(const __hash_table& __u)
1354        {__copy_assign_alloc(__u, integral_constant<bool,
1355             __node_traits::propagate_on_container_copy_assignment::value>());}
1356    void __copy_assign_alloc(const __hash_table& __u, true_type);
1357    _LIBCPP_INLINE_VISIBILITY
1358        void __copy_assign_alloc(const __hash_table&, false_type) {}
1359
1360    void __move_assign(__hash_table& __u, false_type);
1361    void __move_assign(__hash_table& __u, true_type)
1362        _NOEXCEPT_(
1363            is_nothrow_move_assignable<__node_allocator>::value &&
1364            is_nothrow_move_assignable<hasher>::value &&
1365            is_nothrow_move_assignable<key_equal>::value);
1366    _LIBCPP_INLINE_VISIBILITY
1367    void __move_assign_alloc(__hash_table& __u)
1368        _NOEXCEPT_(
1369            !__node_traits::propagate_on_container_move_assignment::value ||
1370            (is_nothrow_move_assignable<__pointer_allocator>::value &&
1371             is_nothrow_move_assignable<__node_allocator>::value))
1372        {__move_assign_alloc(__u, integral_constant<bool,
1373             __node_traits::propagate_on_container_move_assignment::value>());}
1374    _LIBCPP_INLINE_VISIBILITY
1375    void __move_assign_alloc(__hash_table& __u, true_type)
1376        _NOEXCEPT_(
1377            is_nothrow_move_assignable<__pointer_allocator>::value &&
1378            is_nothrow_move_assignable<__node_allocator>::value)
1379    {
1380        __bucket_list_.get_deleter().__alloc() =
1381                _VSTD::move(__u.__bucket_list_.get_deleter().__alloc());
1382        __node_alloc() = _VSTD::move(__u.__node_alloc());
1383    }
1384    _LIBCPP_INLINE_VISIBILITY
1385        void __move_assign_alloc(__hash_table&, false_type) _NOEXCEPT {}
1386
1387    void __deallocate_node(__next_pointer __np) _NOEXCEPT;
1388    __next_pointer __detach() _NOEXCEPT;
1389
1390    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_map;
1391    template <class, class, class, class, class> friend class _LIBCPP_TEMPLATE_VIS unordered_multimap;
1392};
1393
1394template <class _Tp, class _Hash, class _Equal, class _Alloc>
1395inline
1396__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table()
1397    _NOEXCEPT_(
1398        is_nothrow_default_constructible<__bucket_list>::value &&
1399        is_nothrow_default_constructible<__first_node>::value &&
1400        is_nothrow_default_constructible<__node_allocator>::value &&
1401        is_nothrow_default_constructible<hasher>::value &&
1402        is_nothrow_default_constructible<key_equal>::value)
1403    : __p2_(0, __default_init_tag()),
1404      __p3_(1.0f, __default_init_tag())
1405{
1406}
1407
1408template <class _Tp, class _Hash, class _Equal, class _Alloc>
1409inline
1410__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
1411                                                       const key_equal& __eql)
1412    : __bucket_list_(nullptr, __bucket_list_deleter()),
1413      __p1_(),
1414      __p2_(0, __hf),
1415      __p3_(1.0f, __eql)
1416{
1417}
1418
1419template <class _Tp, class _Hash, class _Equal, class _Alloc>
1420__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const hasher& __hf,
1421                                                       const key_equal& __eql,
1422                                                       const allocator_type& __a)
1423    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1424      __p1_(__default_init_tag(), __node_allocator(__a)),
1425      __p2_(0, __hf),
1426      __p3_(1.0f, __eql)
1427{
1428}
1429
1430template <class _Tp, class _Hash, class _Equal, class _Alloc>
1431__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const allocator_type& __a)
1432    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1433      __p1_(__default_init_tag(), __node_allocator(__a)),
1434      __p2_(0, __default_init_tag()),
1435      __p3_(1.0f, __default_init_tag())
1436{
1437}
1438
1439template <class _Tp, class _Hash, class _Equal, class _Alloc>
1440__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u)
1441    : __bucket_list_(nullptr,
1442          __bucket_list_deleter(allocator_traits<__pointer_allocator>::
1443              select_on_container_copy_construction(
1444                  __u.__bucket_list_.get_deleter().__alloc()), 0)),
1445      __p1_(__default_init_tag(), allocator_traits<__node_allocator>::
1446          select_on_container_copy_construction(__u.__node_alloc())),
1447      __p2_(0, __u.hash_function()),
1448      __p3_(__u.__p3_)
1449{
1450}
1451
1452template <class _Tp, class _Hash, class _Equal, class _Alloc>
1453__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(const __hash_table& __u,
1454                                                       const allocator_type& __a)
1455    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1456      __p1_(__default_init_tag(), __node_allocator(__a)),
1457      __p2_(0, __u.hash_function()),
1458      __p3_(__u.__p3_)
1459{
1460}
1461
1462template <class _Tp, class _Hash, class _Equal, class _Alloc>
1463__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u)
1464        _NOEXCEPT_(
1465            is_nothrow_move_constructible<__bucket_list>::value &&
1466            is_nothrow_move_constructible<__first_node>::value &&
1467            is_nothrow_move_constructible<__node_allocator>::value &&
1468            is_nothrow_move_constructible<hasher>::value &&
1469            is_nothrow_move_constructible<key_equal>::value)
1470    : __bucket_list_(_VSTD::move(__u.__bucket_list_)),
1471      __p1_(_VSTD::move(__u.__p1_)),
1472      __p2_(_VSTD::move(__u.__p2_)),
1473      __p3_(_VSTD::move(__u.__p3_))
1474{
1475    if (size() > 0)
1476    {
1477        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
1478            __p1_.first().__ptr();
1479        __u.__p1_.first().__next_ = nullptr;
1480        __u.size() = 0;
1481    }
1482}
1483
1484template <class _Tp, class _Hash, class _Equal, class _Alloc>
1485__hash_table<_Tp, _Hash, _Equal, _Alloc>::__hash_table(__hash_table&& __u,
1486                                                       const allocator_type& __a)
1487    : __bucket_list_(nullptr, __bucket_list_deleter(__pointer_allocator(__a), 0)),
1488      __p1_(__default_init_tag(), __node_allocator(__a)),
1489      __p2_(0, _VSTD::move(__u.hash_function())),
1490      __p3_(_VSTD::move(__u.__p3_))
1491{
1492    if (__a == allocator_type(__u.__node_alloc()))
1493    {
1494        __bucket_list_.reset(__u.__bucket_list_.release());
1495        __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
1496        __u.__bucket_list_.get_deleter().size() = 0;
1497        if (__u.size() > 0)
1498        {
1499            __p1_.first().__next_ = __u.__p1_.first().__next_;
1500            __u.__p1_.first().__next_ = nullptr;
1501            __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
1502                __p1_.first().__ptr();
1503            size() = __u.size();
1504            __u.size() = 0;
1505        }
1506    }
1507}
1508
1509template <class _Tp, class _Hash, class _Equal, class _Alloc>
1510__hash_table<_Tp, _Hash, _Equal, _Alloc>::~__hash_table()
1511{
1512#if defined(_LIBCPP_CXX03_LANG)
1513    static_assert((is_copy_constructible<key_equal>::value),
1514                 "Predicate must be copy-constructible.");
1515    static_assert((is_copy_constructible<hasher>::value),
1516                 "Hasher must be copy-constructible.");
1517#endif
1518
1519    __deallocate_node(__p1_.first().__next_);
1520#if _LIBCPP_DEBUG_LEVEL == 2
1521    __get_db()->__erase_c(this);
1522#endif
1523}
1524
1525template <class _Tp, class _Hash, class _Equal, class _Alloc>
1526void
1527__hash_table<_Tp, _Hash, _Equal, _Alloc>::__copy_assign_alloc(
1528        const __hash_table& __u, true_type)
1529{
1530    if (__node_alloc() != __u.__node_alloc())
1531    {
1532        clear();
1533        __bucket_list_.reset();
1534        __bucket_list_.get_deleter().size() = 0;
1535    }
1536    __bucket_list_.get_deleter().__alloc() = __u.__bucket_list_.get_deleter().__alloc();
1537    __node_alloc() = __u.__node_alloc();
1538}
1539
1540template <class _Tp, class _Hash, class _Equal, class _Alloc>
1541__hash_table<_Tp, _Hash, _Equal, _Alloc>&
1542__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(const __hash_table& __u)
1543{
1544    if (this != &__u)
1545    {
1546        __copy_assign_alloc(__u);
1547        hash_function() = __u.hash_function();
1548        key_eq() = __u.key_eq();
1549        max_load_factor() = __u.max_load_factor();
1550        __assign_multi(__u.begin(), __u.end());
1551    }
1552    return *this;
1553}
1554
1555template <class _Tp, class _Hash, class _Equal, class _Alloc>
1556void
1557__hash_table<_Tp, _Hash, _Equal, _Alloc>::__deallocate_node(__next_pointer __np)
1558    _NOEXCEPT
1559{
1560    __node_allocator& __na = __node_alloc();
1561    while (__np != nullptr)
1562    {
1563        __next_pointer __next = __np->__next_;
1564#if _LIBCPP_DEBUG_LEVEL == 2
1565        __c_node* __c = __get_db()->__find_c_and_lock(this);
1566        for (__i_node** __p = __c->end_; __p != __c->beg_; )
1567        {
1568            --__p;
1569            iterator* __i = static_cast<iterator*>((*__p)->__i_);
1570            if (__i->__node_ == __np)
1571            {
1572                (*__p)->__c_ = nullptr;
1573                if (--__c->end_ != __p)
1574                    memmove(__p, __p+1, (__c->end_ - __p)*sizeof(__i_node*));
1575            }
1576        }
1577        __get_db()->unlock();
1578#endif
1579        __node_pointer __real_np = __np->__upcast();
1580        __node_traits::destroy(__na, _NodeTypes::__get_ptr(__real_np->__value_));
1581        __node_traits::deallocate(__na, __real_np, 1);
1582        __np = __next;
1583    }
1584}
1585
1586template <class _Tp, class _Hash, class _Equal, class _Alloc>
1587typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
1588__hash_table<_Tp, _Hash, _Equal, _Alloc>::__detach() _NOEXCEPT
1589{
1590    size_type __bc = bucket_count();
1591    for (size_type __i = 0; __i < __bc; ++__i)
1592        __bucket_list_[__i] = nullptr;
1593    size() = 0;
1594    __next_pointer __cache = __p1_.first().__next_;
1595    __p1_.first().__next_ = nullptr;
1596    return __cache;
1597}
1598
1599template <class _Tp, class _Hash, class _Equal, class _Alloc>
1600void
1601__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
1602        __hash_table& __u, true_type)
1603    _NOEXCEPT_(
1604        is_nothrow_move_assignable<__node_allocator>::value &&
1605        is_nothrow_move_assignable<hasher>::value &&
1606        is_nothrow_move_assignable<key_equal>::value)
1607{
1608    clear();
1609    __bucket_list_.reset(__u.__bucket_list_.release());
1610    __bucket_list_.get_deleter().size() = __u.__bucket_list_.get_deleter().size();
1611    __u.__bucket_list_.get_deleter().size() = 0;
1612    __move_assign_alloc(__u);
1613    size() = __u.size();
1614    hash_function() = _VSTD::move(__u.hash_function());
1615    max_load_factor() = __u.max_load_factor();
1616    key_eq() = _VSTD::move(__u.key_eq());
1617    __p1_.first().__next_ = __u.__p1_.first().__next_;
1618    if (size() > 0)
1619    {
1620        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
1621            __p1_.first().__ptr();
1622        __u.__p1_.first().__next_ = nullptr;
1623        __u.size() = 0;
1624    }
1625#if _LIBCPP_DEBUG_LEVEL == 2
1626    __get_db()->swap(this, &__u);
1627#endif
1628}
1629
1630template <class _Tp, class _Hash, class _Equal, class _Alloc>
1631void
1632__hash_table<_Tp, _Hash, _Equal, _Alloc>::__move_assign(
1633        __hash_table& __u, false_type)
1634{
1635    if (__node_alloc() == __u.__node_alloc())
1636        __move_assign(__u, true_type());
1637    else
1638    {
1639        hash_function() = _VSTD::move(__u.hash_function());
1640        key_eq() = _VSTD::move(__u.key_eq());
1641        max_load_factor() = __u.max_load_factor();
1642        if (bucket_count() != 0)
1643        {
1644            __next_pointer __cache = __detach();
1645#ifndef _LIBCPP_NO_EXCEPTIONS
1646            try
1647            {
1648#endif  // _LIBCPP_NO_EXCEPTIONS
1649                const_iterator __i = __u.begin();
1650                while (__cache != nullptr && __u.size() != 0)
1651                {
1652                    __cache->__upcast()->__value_ =
1653                        _VSTD::move(__u.remove(__i++)->__value_);
1654                    __next_pointer __next = __cache->__next_;
1655                    __node_insert_multi(__cache->__upcast());
1656                    __cache = __next;
1657                }
1658#ifndef _LIBCPP_NO_EXCEPTIONS
1659            }
1660            catch (...)
1661            {
1662                __deallocate_node(__cache);
1663                throw;
1664            }
1665#endif  // _LIBCPP_NO_EXCEPTIONS
1666            __deallocate_node(__cache);
1667        }
1668        const_iterator __i = __u.begin();
1669        while (__u.size() != 0)
1670        {
1671            __node_holder __h = __construct_node(_NodeTypes::__move(__u.remove(__i++)->__value_));
1672            __node_insert_multi(__h.get());
1673            __h.release();
1674        }
1675    }
1676}
1677
1678template <class _Tp, class _Hash, class _Equal, class _Alloc>
1679inline
1680__hash_table<_Tp, _Hash, _Equal, _Alloc>&
1681__hash_table<_Tp, _Hash, _Equal, _Alloc>::operator=(__hash_table&& __u)
1682    _NOEXCEPT_(
1683        __node_traits::propagate_on_container_move_assignment::value &&
1684        is_nothrow_move_assignable<__node_allocator>::value &&
1685        is_nothrow_move_assignable<hasher>::value &&
1686        is_nothrow_move_assignable<key_equal>::value)
1687{
1688    __move_assign(__u, integral_constant<bool,
1689                  __node_traits::propagate_on_container_move_assignment::value>());
1690    return *this;
1691}
1692
1693template <class _Tp, class _Hash, class _Equal, class _Alloc>
1694template <class _InputIterator>
1695void
1696__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_unique(_InputIterator __first,
1697                                                          _InputIterator __last)
1698{
1699    typedef iterator_traits<_InputIterator> _ITraits;
1700    typedef typename _ITraits::value_type _ItValueType;
1701    static_assert((is_same<_ItValueType, __container_value_type>::value),
1702                  "__assign_unique may only be called with the containers value type");
1703
1704    if (bucket_count() != 0)
1705    {
1706        __next_pointer __cache = __detach();
1707#ifndef _LIBCPP_NO_EXCEPTIONS
1708        try
1709        {
1710#endif  // _LIBCPP_NO_EXCEPTIONS
1711            for (; __cache != nullptr && __first != __last; ++__first)
1712            {
1713                __cache->__upcast()->__value_ = *__first;
1714                __next_pointer __next = __cache->__next_;
1715                __node_insert_unique(__cache->__upcast());
1716                __cache = __next;
1717            }
1718#ifndef _LIBCPP_NO_EXCEPTIONS
1719        }
1720        catch (...)
1721        {
1722            __deallocate_node(__cache);
1723            throw;
1724        }
1725#endif  // _LIBCPP_NO_EXCEPTIONS
1726        __deallocate_node(__cache);
1727    }
1728    for (; __first != __last; ++__first)
1729        __insert_unique(*__first);
1730}
1731
1732template <class _Tp, class _Hash, class _Equal, class _Alloc>
1733template <class _InputIterator>
1734void
1735__hash_table<_Tp, _Hash, _Equal, _Alloc>::__assign_multi(_InputIterator __first,
1736                                                         _InputIterator __last)
1737{
1738    typedef iterator_traits<_InputIterator> _ITraits;
1739    typedef typename _ITraits::value_type _ItValueType;
1740    static_assert((is_same<_ItValueType, __container_value_type>::value ||
1741                  is_same<_ItValueType, __node_value_type>::value),
1742                  "__assign_multi may only be called with the containers value type"
1743                  " or the nodes value type");
1744    if (bucket_count() != 0)
1745    {
1746        __next_pointer __cache = __detach();
1747#ifndef _LIBCPP_NO_EXCEPTIONS
1748        try
1749        {
1750#endif  // _LIBCPP_NO_EXCEPTIONS
1751            for (; __cache != nullptr && __first != __last; ++__first)
1752            {
1753                __cache->__upcast()->__value_ = *__first;
1754                __next_pointer __next = __cache->__next_;
1755                __node_insert_multi(__cache->__upcast());
1756                __cache = __next;
1757            }
1758#ifndef _LIBCPP_NO_EXCEPTIONS
1759        }
1760        catch (...)
1761        {
1762            __deallocate_node(__cache);
1763            throw;
1764        }
1765#endif  // _LIBCPP_NO_EXCEPTIONS
1766        __deallocate_node(__cache);
1767    }
1768    for (; __first != __last; ++__first)
1769        __insert_multi(_NodeTypes::__get_value(*__first));
1770}
1771
1772template <class _Tp, class _Hash, class _Equal, class _Alloc>
1773inline
1774typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1775__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() _NOEXCEPT
1776{
1777#if _LIBCPP_DEBUG_LEVEL == 2
1778    return iterator(__p1_.first().__next_, this);
1779#else
1780    return iterator(__p1_.first().__next_);
1781#endif
1782}
1783
1784template <class _Tp, class _Hash, class _Equal, class _Alloc>
1785inline
1786typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
1787__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() _NOEXCEPT
1788{
1789#if _LIBCPP_DEBUG_LEVEL == 2
1790    return iterator(nullptr, this);
1791#else
1792    return iterator(nullptr);
1793#endif
1794}
1795
1796template <class _Tp, class _Hash, class _Equal, class _Alloc>
1797inline
1798typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
1799__hash_table<_Tp, _Hash, _Equal, _Alloc>::begin() const _NOEXCEPT
1800{
1801#if _LIBCPP_DEBUG_LEVEL == 2
1802    return const_iterator(__p1_.first().__next_, this);
1803#else
1804    return const_iterator(__p1_.first().__next_);
1805#endif
1806}
1807
1808template <class _Tp, class _Hash, class _Equal, class _Alloc>
1809inline
1810typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
1811__hash_table<_Tp, _Hash, _Equal, _Alloc>::end() const _NOEXCEPT
1812{
1813#if _LIBCPP_DEBUG_LEVEL == 2
1814    return const_iterator(nullptr, this);
1815#else
1816    return const_iterator(nullptr);
1817#endif
1818}
1819
1820template <class _Tp, class _Hash, class _Equal, class _Alloc>
1821void
1822__hash_table<_Tp, _Hash, _Equal, _Alloc>::clear() _NOEXCEPT
1823{
1824    if (size() > 0)
1825    {
1826        __deallocate_node(__p1_.first().__next_);
1827        __p1_.first().__next_ = nullptr;
1828        size_type __bc = bucket_count();
1829        for (size_type __i = 0; __i < __bc; ++__i)
1830            __bucket_list_[__i] = nullptr;
1831        size() = 0;
1832    }
1833}
1834
1835
1836// Prepare the container for an insertion of the value __value with the hash
1837// __hash. This does a lookup into the container to see if __value is already
1838// present, and performs a rehash if necessary. Returns a pointer to the
1839// existing element if it exists, otherwise nullptr.
1840//
1841// Note that this function does forward exceptions if key_eq() throws, and never
1842// mutates __value or actually inserts into the map.
1843template <class _Tp, class _Hash, class _Equal, class _Alloc>
1844_LIBCPP_INLINE_VISIBILITY
1845typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
1846__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique_prepare(
1847    size_t __hash, value_type& __value)
1848{
1849    size_type __bc = bucket_count();
1850
1851    if (__bc != 0)
1852    {
1853        size_t __chash = __constrain_hash(__hash, __bc);
1854        __next_pointer __ndptr = __bucket_list_[__chash];
1855        if (__ndptr != nullptr)
1856        {
1857            for (__ndptr = __ndptr->__next_; __ndptr != nullptr &&
1858                                             __constrain_hash(__ndptr->__hash(), __bc) == __chash;
1859                                                     __ndptr = __ndptr->__next_)
1860            {
1861                if (key_eq()(__ndptr->__upcast()->__value_, __value))
1862                    return __ndptr;
1863            }
1864        }
1865    }
1866    if (size()+1 > __bc * max_load_factor() || __bc == 0)
1867    {
1868        rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
1869                                     size_type(ceil(float(size() + 1) / max_load_factor()))));
1870    }
1871    return nullptr;
1872}
1873
1874// Insert the node __nd into the container by pushing it into the right bucket,
1875// and updating size(). Assumes that __nd->__hash is up-to-date, and that
1876// rehashing has already occurred and that no element with the same key exists
1877// in the map.
1878template <class _Tp, class _Hash, class _Equal, class _Alloc>
1879_LIBCPP_INLINE_VISIBILITY
1880void
1881__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique_perform(
1882    __node_pointer __nd) _NOEXCEPT
1883{
1884    size_type __bc = bucket_count();
1885    size_t __chash = __constrain_hash(__nd->__hash(), __bc);
1886    // insert_after __bucket_list_[__chash], or __first_node if bucket is null
1887    __next_pointer __pn = __bucket_list_[__chash];
1888    if (__pn == nullptr)
1889    {
1890        __pn =__p1_.first().__ptr();
1891        __nd->__next_ = __pn->__next_;
1892        __pn->__next_ = __nd->__ptr();
1893        // fix up __bucket_list_
1894        __bucket_list_[__chash] = __pn;
1895        if (__nd->__next_ != nullptr)
1896            __bucket_list_[__constrain_hash(__nd->__next_->__hash(), __bc)] = __nd->__ptr();
1897    }
1898    else
1899    {
1900        __nd->__next_ = __pn->__next_;
1901        __pn->__next_ = __nd->__ptr();
1902    }
1903    ++size();
1904}
1905
1906template <class _Tp, class _Hash, class _Equal, class _Alloc>
1907pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
1908__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_unique(__node_pointer __nd)
1909{
1910    __nd->__hash_ = hash_function()(__nd->__value_);
1911    __next_pointer __existing_node =
1912        __node_insert_unique_prepare(__nd->__hash(), __nd->__value_);
1913
1914    // Insert the node, unless it already exists in the container.
1915    bool __inserted = false;
1916    if (__existing_node == nullptr)
1917    {
1918        __node_insert_unique_perform(__nd);
1919        __existing_node = __nd->__ptr();
1920        __inserted = true;
1921    }
1922#if _LIBCPP_DEBUG_LEVEL == 2
1923    return pair<iterator, bool>(iterator(__existing_node, this), __inserted);
1924#else
1925    return pair<iterator, bool>(iterator(__existing_node), __inserted);
1926#endif
1927}
1928
1929// Prepare the container for an insertion of the value __cp_val with the hash
1930// __cp_hash. This does a lookup into the container to see if __cp_value is
1931// already present, and performs a rehash if necessary. Returns a pointer to the
1932// last occurance of __cp_val in the map.
1933//
1934// Note that this function does forward exceptions if key_eq() throws, and never
1935// mutates __value or actually inserts into the map.
1936template <class _Tp, class _Hash, class _Equal, class _Alloc>
1937typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__next_pointer
1938__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi_prepare(
1939    size_t __cp_hash, value_type& __cp_val)
1940{
1941    size_type __bc = bucket_count();
1942    if (size()+1 > __bc * max_load_factor() || __bc == 0)
1943    {
1944        rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
1945                       size_type(ceil(float(size() + 1) / max_load_factor()))));
1946        __bc = bucket_count();
1947    }
1948    size_t __chash = __constrain_hash(__cp_hash, __bc);
1949    __next_pointer __pn = __bucket_list_[__chash];
1950    if (__pn != nullptr)
1951    {
1952        for (bool __found = false; __pn->__next_ != nullptr &&
1953                                   __constrain_hash(__pn->__next_->__hash(), __bc) == __chash;
1954                                                           __pn = __pn->__next_)
1955        {
1956            //      __found    key_eq()     action
1957            //      false       false       loop
1958            //      true        true        loop
1959            //      false       true        set __found to true
1960            //      true        false       break
1961            if (__found != (__pn->__next_->__hash() == __cp_hash &&
1962                            key_eq()(__pn->__next_->__upcast()->__value_, __cp_val)))
1963            {
1964                if (!__found)
1965                    __found = true;
1966                else
1967                    break;
1968            }
1969        }
1970    }
1971    return __pn;
1972}
1973
1974// Insert the node __cp into the container after __pn (which is the last node in
1975// the bucket that compares equal to __cp). Rehashing, and checking for
1976// uniqueness has already been performed (in __node_insert_multi_prepare), so
1977// all we need to do is update the bucket and size(). Assumes that __cp->__hash
1978// is up-to-date.
1979template <class _Tp, class _Hash, class _Equal, class _Alloc>
1980void
1981__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi_perform(
1982    __node_pointer __cp, __next_pointer __pn) _NOEXCEPT
1983{
1984    size_type __bc = bucket_count();
1985    size_t __chash = __constrain_hash(__cp->__hash_, __bc);
1986    if (__pn == nullptr)
1987    {
1988        __pn =__p1_.first().__ptr();
1989        __cp->__next_ = __pn->__next_;
1990        __pn->__next_ = __cp->__ptr();
1991        // fix up __bucket_list_
1992        __bucket_list_[__chash] = __pn;
1993        if (__cp->__next_ != nullptr)
1994            __bucket_list_[__constrain_hash(__cp->__next_->__hash(), __bc)]
1995                = __cp->__ptr();
1996    }
1997    else
1998    {
1999        __cp->__next_ = __pn->__next_;
2000        __pn->__next_ = __cp->__ptr();
2001        if (__cp->__next_ != nullptr)
2002        {
2003            size_t __nhash = __constrain_hash(__cp->__next_->__hash(), __bc);
2004            if (__nhash != __chash)
2005                __bucket_list_[__nhash] = __cp->__ptr();
2006        }
2007    }
2008    ++size();
2009}
2010
2011
2012template <class _Tp, class _Hash, class _Equal, class _Alloc>
2013typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2014__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(__node_pointer __cp)
2015{
2016    __cp->__hash_ = hash_function()(__cp->__value_);
2017    __next_pointer __pn = __node_insert_multi_prepare(__cp->__hash(), __cp->__value_);
2018    __node_insert_multi_perform(__cp, __pn);
2019
2020#if _LIBCPP_DEBUG_LEVEL == 2
2021    return iterator(__cp->__ptr(), this);
2022#else
2023    return iterator(__cp->__ptr());
2024#endif
2025}
2026
2027template <class _Tp, class _Hash, class _Equal, class _Alloc>
2028typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2029__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_insert_multi(
2030        const_iterator __p, __node_pointer __cp)
2031{
2032#if _LIBCPP_DEBUG_LEVEL == 2
2033    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
2034        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
2035        " referring to this unordered container");
2036#endif
2037    if (__p != end() && key_eq()(*__p, __cp->__value_))
2038    {
2039        __next_pointer __np = __p.__node_;
2040        __cp->__hash_ = __np->__hash();
2041        size_type __bc = bucket_count();
2042        if (size()+1 > __bc * max_load_factor() || __bc == 0)
2043        {
2044            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
2045                           size_type(ceil(float(size() + 1) / max_load_factor()))));
2046            __bc = bucket_count();
2047        }
2048        size_t __chash = __constrain_hash(__cp->__hash_, __bc);
2049        __next_pointer __pp = __bucket_list_[__chash];
2050        while (__pp->__next_ != __np)
2051            __pp = __pp->__next_;
2052        __cp->__next_ = __np;
2053        __pp->__next_ = static_cast<__next_pointer>(__cp);
2054        ++size();
2055#if _LIBCPP_DEBUG_LEVEL == 2
2056        return iterator(static_cast<__next_pointer>(__cp), this);
2057#else
2058        return iterator(static_cast<__next_pointer>(__cp));
2059#endif
2060    }
2061    return __node_insert_multi(__cp);
2062}
2063
2064
2065
2066template <class _Tp, class _Hash, class _Equal, class _Alloc>
2067template <class _Key, class ..._Args>
2068pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
2069__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_key_args(_Key const& __k, _Args&&... __args)
2070{
2071
2072    size_t __hash = hash_function()(__k);
2073    size_type __bc = bucket_count();
2074    bool __inserted = false;
2075    __next_pointer __nd;
2076    size_t __chash;
2077    if (__bc != 0)
2078    {
2079        __chash = __constrain_hash(__hash, __bc);
2080        __nd = __bucket_list_[__chash];
2081        if (__nd != nullptr)
2082        {
2083            for (__nd = __nd->__next_; __nd != nullptr &&
2084                (__nd->__hash() == __hash || __constrain_hash(__nd->__hash(), __bc) == __chash);
2085                                                           __nd = __nd->__next_)
2086            {
2087                if (key_eq()(__nd->__upcast()->__value_, __k))
2088                    goto __done;
2089            }
2090        }
2091    }
2092    {
2093        __node_holder __h = __construct_node_hash(__hash, _VSTD::forward<_Args>(__args)...);
2094        if (size()+1 > __bc * max_load_factor() || __bc == 0)
2095        {
2096            rehash(_VSTD::max<size_type>(2 * __bc + !__is_hash_power2(__bc),
2097                           size_type(ceil(float(size() + 1) / max_load_factor()))));
2098            __bc = bucket_count();
2099            __chash = __constrain_hash(__hash, __bc);
2100        }
2101        // insert_after __bucket_list_[__chash], or __first_node if bucket is null
2102        __next_pointer __pn = __bucket_list_[__chash];
2103        if (__pn == nullptr)
2104        {
2105            __pn = __p1_.first().__ptr();
2106            __h->__next_ = __pn->__next_;
2107            __pn->__next_ = __h.get()->__ptr();
2108            // fix up __bucket_list_
2109            __bucket_list_[__chash] = __pn;
2110            if (__h->__next_ != nullptr)
2111                __bucket_list_[__constrain_hash(__h->__next_->__hash(), __bc)]
2112                    = __h.get()->__ptr();
2113        }
2114        else
2115        {
2116            __h->__next_ = __pn->__next_;
2117            __pn->__next_ = static_cast<__next_pointer>(__h.get());
2118        }
2119        __nd = static_cast<__next_pointer>(__h.release());
2120        // increment size
2121        ++size();
2122        __inserted = true;
2123    }
2124__done:
2125#if _LIBCPP_DEBUG_LEVEL == 2
2126    return pair<iterator, bool>(iterator(__nd, this), __inserted);
2127#else
2128    return pair<iterator, bool>(iterator(__nd), __inserted);
2129#endif
2130}
2131
2132template <class _Tp, class _Hash, class _Equal, class _Alloc>
2133template <class... _Args>
2134pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator, bool>
2135__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_unique_impl(_Args&&... __args)
2136{
2137    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2138    pair<iterator, bool> __r = __node_insert_unique(__h.get());
2139    if (__r.second)
2140        __h.release();
2141    return __r;
2142}
2143
2144template <class _Tp, class _Hash, class _Equal, class _Alloc>
2145template <class... _Args>
2146typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2147__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_multi(_Args&&... __args)
2148{
2149    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2150    iterator __r = __node_insert_multi(__h.get());
2151    __h.release();
2152    return __r;
2153}
2154
2155template <class _Tp, class _Hash, class _Equal, class _Alloc>
2156template <class... _Args>
2157typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2158__hash_table<_Tp, _Hash, _Equal, _Alloc>::__emplace_hint_multi(
2159        const_iterator __p, _Args&&... __args)
2160{
2161#if _LIBCPP_DEBUG_LEVEL == 2
2162    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
2163        "unordered container::emplace_hint(const_iterator, args...) called with an iterator not"
2164        " referring to this unordered container");
2165#endif
2166    __node_holder __h = __construct_node(_VSTD::forward<_Args>(__args)...);
2167    iterator __r = __node_insert_multi(__p, __h.get());
2168    __h.release();
2169    return __r;
2170}
2171
2172#if _LIBCPP_STD_VER > 14
2173template <class _Tp, class _Hash, class _Equal, class _Alloc>
2174template <class _NodeHandle, class _InsertReturnType>
2175_LIBCPP_INLINE_VISIBILITY
2176_InsertReturnType
2177__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
2178    _NodeHandle&& __nh)
2179{
2180    if (__nh.empty())
2181        return _InsertReturnType{end(), false, _NodeHandle()};
2182    pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
2183    if (__result.second)
2184        __nh.__release_ptr();
2185    return _InsertReturnType{__result.first, __result.second, _VSTD::move(__nh)};
2186}
2187
2188template <class _Tp, class _Hash, class _Equal, class _Alloc>
2189template <class _NodeHandle>
2190_LIBCPP_INLINE_VISIBILITY
2191typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2192__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_unique(
2193    const_iterator, _NodeHandle&& __nh)
2194{
2195    if (__nh.empty())
2196        return end();
2197    pair<iterator, bool> __result = __node_insert_unique(__nh.__ptr_);
2198    if (__result.second)
2199        __nh.__release_ptr();
2200    return __result.first;
2201}
2202
2203template <class _Tp, class _Hash, class _Equal, class _Alloc>
2204template <class _NodeHandle>
2205_LIBCPP_INLINE_VISIBILITY
2206_NodeHandle
2207__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_extract(
2208    key_type const& __key)
2209{
2210    iterator __i = find(__key);
2211    if (__i == end())
2212        return _NodeHandle();
2213    return __node_handle_extract<_NodeHandle>(__i);
2214}
2215
2216template <class _Tp, class _Hash, class _Equal, class _Alloc>
2217template <class _NodeHandle>
2218_LIBCPP_INLINE_VISIBILITY
2219_NodeHandle
2220__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_extract(
2221    const_iterator __p)
2222{
2223    allocator_type __alloc(__node_alloc());
2224    return _NodeHandle(remove(__p).release(), __alloc);
2225}
2226
2227template <class _Tp, class _Hash, class _Equal, class _Alloc>
2228template <class _Table>
2229_LIBCPP_INLINE_VISIBILITY
2230void
2231__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_merge_unique(
2232    _Table& __source)
2233{
2234    static_assert(is_same<__node, typename _Table::__node>::value, "");
2235
2236    for (typename _Table::iterator __it = __source.begin();
2237         __it != __source.end();)
2238    {
2239        __node_pointer __src_ptr = __it.__node_->__upcast();
2240        size_t __hash = hash_function()(__src_ptr->__value_);
2241        __next_pointer __existing_node =
2242            __node_insert_unique_prepare(__hash, __src_ptr->__value_);
2243        auto __prev_iter = __it++;
2244        if (__existing_node == nullptr)
2245        {
2246            (void)__source.remove(__prev_iter).release();
2247            __src_ptr->__hash_ = __hash;
2248            __node_insert_unique_perform(__src_ptr);
2249        }
2250    }
2251}
2252
2253template <class _Tp, class _Hash, class _Equal, class _Alloc>
2254template <class _NodeHandle>
2255_LIBCPP_INLINE_VISIBILITY
2256typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2257__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
2258    _NodeHandle&& __nh)
2259{
2260    if (__nh.empty())
2261        return end();
2262    iterator __result = __node_insert_multi(__nh.__ptr_);
2263    __nh.__release_ptr();
2264    return __result;
2265}
2266
2267template <class _Tp, class _Hash, class _Equal, class _Alloc>
2268template <class _NodeHandle>
2269_LIBCPP_INLINE_VISIBILITY
2270typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2271__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_insert_multi(
2272    const_iterator __hint, _NodeHandle&& __nh)
2273{
2274    if (__nh.empty())
2275        return end();
2276    iterator __result = __node_insert_multi(__hint, __nh.__ptr_);
2277    __nh.__release_ptr();
2278    return __result;
2279}
2280
2281template <class _Tp, class _Hash, class _Equal, class _Alloc>
2282template <class _Table>
2283_LIBCPP_INLINE_VISIBILITY
2284void
2285__hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_handle_merge_multi(
2286    _Table& __source)
2287{
2288    static_assert(is_same<typename _Table::__node, __node>::value, "");
2289
2290    for (typename _Table::iterator __it = __source.begin();
2291         __it != __source.end();)
2292    {
2293        __node_pointer __src_ptr = __it.__node_->__upcast();
2294        size_t __src_hash = hash_function()(__src_ptr->__value_);
2295        __next_pointer __pn =
2296            __node_insert_multi_prepare(__src_hash, __src_ptr->__value_);
2297        (void)__source.remove(__it++).release();
2298        __src_ptr->__hash_ = __src_hash;
2299        __node_insert_multi_perform(__src_ptr, __pn);
2300    }
2301}
2302#endif  // _LIBCPP_STD_VER > 14
2303
2304template <class _Tp, class _Hash, class _Equal, class _Alloc>
2305void
2306__hash_table<_Tp, _Hash, _Equal, _Alloc>::rehash(size_type __n)
2307_LIBCPP_DISABLE_UBSAN_UNSIGNED_INTEGER_CHECK
2308{
2309    if (__n == 1)
2310        __n = 2;
2311    else if (__n & (__n - 1))
2312        __n = __next_prime(__n);
2313    size_type __bc = bucket_count();
2314    if (__n > __bc)
2315        __rehash(__n);
2316    else if (__n < __bc)
2317    {
2318        __n = _VSTD::max<size_type>
2319              (
2320                  __n,
2321                  __is_hash_power2(__bc) ? __next_hash_pow2(size_t(ceil(float(size()) / max_load_factor()))) :
2322                                           __next_prime(size_t(ceil(float(size()) / max_load_factor())))
2323              );
2324        if (__n < __bc)
2325            __rehash(__n);
2326    }
2327}
2328
2329template <class _Tp, class _Hash, class _Equal, class _Alloc>
2330void
2331__hash_table<_Tp, _Hash, _Equal, _Alloc>::__rehash(size_type __nbc)
2332{
2333#if _LIBCPP_DEBUG_LEVEL == 2
2334    __get_db()->__invalidate_all(this);
2335#endif
2336    __pointer_allocator& __npa = __bucket_list_.get_deleter().__alloc();
2337    __bucket_list_.reset(__nbc > 0 ?
2338                      __pointer_alloc_traits::allocate(__npa, __nbc) : nullptr);
2339    __bucket_list_.get_deleter().size() = __nbc;
2340    if (__nbc > 0)
2341    {
2342        for (size_type __i = 0; __i < __nbc; ++__i)
2343            __bucket_list_[__i] = nullptr;
2344        __next_pointer __pp = __p1_.first().__ptr();
2345        __next_pointer __cp = __pp->__next_;
2346        if (__cp != nullptr)
2347        {
2348            size_type __chash = __constrain_hash(__cp->__hash(), __nbc);
2349            __bucket_list_[__chash] = __pp;
2350            size_type __phash = __chash;
2351            for (__pp = __cp, __cp = __cp->__next_; __cp != nullptr;
2352                                                           __cp = __pp->__next_)
2353            {
2354                __chash = __constrain_hash(__cp->__hash(), __nbc);
2355                if (__chash == __phash)
2356                    __pp = __cp;
2357                else
2358                {
2359                    if (__bucket_list_[__chash] == nullptr)
2360                    {
2361                        __bucket_list_[__chash] = __pp;
2362                        __pp = __cp;
2363                        __phash = __chash;
2364                    }
2365                    else
2366                    {
2367                        __next_pointer __np = __cp;
2368                        for (; __np->__next_ != nullptr &&
2369                               key_eq()(__cp->__upcast()->__value_,
2370                                        __np->__next_->__upcast()->__value_);
2371                                                           __np = __np->__next_)
2372                            ;
2373                        __pp->__next_ = __np->__next_;
2374                        __np->__next_ = __bucket_list_[__chash]->__next_;
2375                        __bucket_list_[__chash]->__next_ = __cp;
2376
2377                    }
2378                }
2379            }
2380        }
2381    }
2382}
2383
2384template <class _Tp, class _Hash, class _Equal, class _Alloc>
2385template <class _Key>
2386typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2387__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k)
2388{
2389    size_t __hash = hash_function()(__k);
2390    size_type __bc = bucket_count();
2391    if (__bc != 0)
2392    {
2393        size_t __chash = __constrain_hash(__hash, __bc);
2394        __next_pointer __nd = __bucket_list_[__chash];
2395        if (__nd != nullptr)
2396        {
2397            for (__nd = __nd->__next_; __nd != nullptr &&
2398                (__nd->__hash() == __hash
2399                  || __constrain_hash(__nd->__hash(), __bc) == __chash);
2400                                                           __nd = __nd->__next_)
2401            {
2402                if ((__nd->__hash() == __hash)
2403                    && key_eq()(__nd->__upcast()->__value_, __k))
2404#if _LIBCPP_DEBUG_LEVEL == 2
2405                    return iterator(__nd, this);
2406#else
2407                    return iterator(__nd);
2408#endif
2409            }
2410        }
2411    }
2412    return end();
2413}
2414
2415template <class _Tp, class _Hash, class _Equal, class _Alloc>
2416template <class _Key>
2417typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator
2418__hash_table<_Tp, _Hash, _Equal, _Alloc>::find(const _Key& __k) const
2419{
2420    size_t __hash = hash_function()(__k);
2421    size_type __bc = bucket_count();
2422    if (__bc != 0)
2423    {
2424        size_t __chash = __constrain_hash(__hash, __bc);
2425        __next_pointer __nd = __bucket_list_[__chash];
2426        if (__nd != nullptr)
2427        {
2428            for (__nd = __nd->__next_; __nd != nullptr &&
2429                (__hash == __nd->__hash()
2430                    || __constrain_hash(__nd->__hash(), __bc) == __chash);
2431                                                           __nd = __nd->__next_)
2432            {
2433                if ((__nd->__hash() == __hash)
2434                    && key_eq()(__nd->__upcast()->__value_, __k))
2435#if _LIBCPP_DEBUG_LEVEL == 2
2436                    return const_iterator(__nd, this);
2437#else
2438                    return const_iterator(__nd);
2439#endif
2440            }
2441        }
2442
2443    }
2444    return end();
2445}
2446
2447template <class _Tp, class _Hash, class _Equal, class _Alloc>
2448template <class ..._Args>
2449typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2450__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node(_Args&& ...__args)
2451{
2452    static_assert(!__is_hash_value_type<_Args...>::value,
2453                  "Construct cannot be called with a hash value type");
2454    __node_allocator& __na = __node_alloc();
2455    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
2456    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_), _VSTD::forward<_Args>(__args)...);
2457    __h.get_deleter().__value_constructed = true;
2458    __h->__hash_ = hash_function()(__h->__value_);
2459    __h->__next_ = nullptr;
2460    return __h;
2461}
2462
2463template <class _Tp, class _Hash, class _Equal, class _Alloc>
2464template <class _First, class ..._Rest>
2465typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2466__hash_table<_Tp, _Hash, _Equal, _Alloc>::__construct_node_hash(
2467    size_t __hash, _First&& __f, _Rest&& ...__rest)
2468{
2469    static_assert(!__is_hash_value_type<_First, _Rest...>::value,
2470                  "Construct cannot be called with a hash value type");
2471    __node_allocator& __na = __node_alloc();
2472    __node_holder __h(__node_traits::allocate(__na, 1), _Dp(__na));
2473    __node_traits::construct(__na, _NodeTypes::__get_ptr(__h->__value_),
2474                             _VSTD::forward<_First>(__f),
2475                             _VSTD::forward<_Rest>(__rest)...);
2476    __h.get_deleter().__value_constructed = true;
2477    __h->__hash_ = __hash;
2478    __h->__next_ = nullptr;
2479    return __h;
2480}
2481
2482template <class _Tp, class _Hash, class _Equal, class _Alloc>
2483typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2484__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __p)
2485{
2486    __next_pointer __np = __p.__node_;
2487#if _LIBCPP_DEBUG_LEVEL == 2
2488    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__p) == this,
2489        "unordered container erase(iterator) called with an iterator not"
2490        " referring to this container");
2491    _LIBCPP_ASSERT(__p != end(),
2492        "unordered container erase(iterator) called with a non-dereferenceable iterator");
2493    iterator __r(__np, this);
2494#else
2495    iterator __r(__np);
2496#endif
2497    ++__r;
2498    remove(__p);
2499    return __r;
2500}
2501
2502template <class _Tp, class _Hash, class _Equal, class _Alloc>
2503typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator
2504__hash_table<_Tp, _Hash, _Equal, _Alloc>::erase(const_iterator __first,
2505                                                const_iterator __last)
2506{
2507#if _LIBCPP_DEBUG_LEVEL == 2
2508    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__first) == this,
2509        "unodered container::erase(iterator, iterator) called with an iterator not"
2510        " referring to this unodered container");
2511    _LIBCPP_ASSERT(__get_const_db()->__find_c_from_i(&__last) == this,
2512        "unodered container::erase(iterator, iterator) called with an iterator not"
2513        " referring to this unodered container");
2514#endif
2515    for (const_iterator __p = __first; __first != __last; __p = __first)
2516    {
2517        ++__first;
2518        erase(__p);
2519    }
2520    __next_pointer __np = __last.__node_;
2521#if _LIBCPP_DEBUG_LEVEL == 2
2522    return iterator (__np, this);
2523#else
2524    return iterator (__np);
2525#endif
2526}
2527
2528template <class _Tp, class _Hash, class _Equal, class _Alloc>
2529template <class _Key>
2530typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2531__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_unique(const _Key& __k)
2532{
2533    iterator __i = find(__k);
2534    if (__i == end())
2535        return 0;
2536    erase(__i);
2537    return 1;
2538}
2539
2540template <class _Tp, class _Hash, class _Equal, class _Alloc>
2541template <class _Key>
2542typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2543__hash_table<_Tp, _Hash, _Equal, _Alloc>::__erase_multi(const _Key& __k)
2544{
2545    size_type __r = 0;
2546    iterator __i = find(__k);
2547    if (__i != end())
2548    {
2549        iterator __e = end();
2550        do
2551        {
2552            erase(__i++);
2553            ++__r;
2554        } while (__i != __e && key_eq()(*__i, __k));
2555    }
2556    return __r;
2557}
2558
2559template <class _Tp, class _Hash, class _Equal, class _Alloc>
2560typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::__node_holder
2561__hash_table<_Tp, _Hash, _Equal, _Alloc>::remove(const_iterator __p) _NOEXCEPT
2562{
2563    // current node
2564    __next_pointer __cn = __p.__node_;
2565    size_type __bc = bucket_count();
2566    size_t __chash = __constrain_hash(__cn->__hash(), __bc);
2567    // find previous node
2568    __next_pointer __pn = __bucket_list_[__chash];
2569    for (; __pn->__next_ != __cn; __pn = __pn->__next_)
2570        ;
2571    // Fix up __bucket_list_
2572        // if __pn is not in same bucket (before begin is not in same bucket) &&
2573        //    if __cn->__next_ is not in same bucket (nullptr is not in same bucket)
2574    if (__pn == __p1_.first().__ptr()
2575            || __constrain_hash(__pn->__hash(), __bc) != __chash)
2576    {
2577        if (__cn->__next_ == nullptr
2578            || __constrain_hash(__cn->__next_->__hash(), __bc) != __chash)
2579            __bucket_list_[__chash] = nullptr;
2580    }
2581        // if __cn->__next_ is not in same bucket (nullptr is in same bucket)
2582    if (__cn->__next_ != nullptr)
2583    {
2584        size_t __nhash = __constrain_hash(__cn->__next_->__hash(), __bc);
2585        if (__nhash != __chash)
2586            __bucket_list_[__nhash] = __pn;
2587    }
2588    // remove __cn
2589    __pn->__next_ = __cn->__next_;
2590    __cn->__next_ = nullptr;
2591    --size();
2592#if _LIBCPP_DEBUG_LEVEL == 2
2593    __c_node* __c = __get_db()->__find_c_and_lock(this);
2594    for (__i_node** __dp = __c->end_; __dp != __c->beg_; )
2595    {
2596        --__dp;
2597        iterator* __i = static_cast<iterator*>((*__dp)->__i_);
2598        if (__i->__node_ == __cn)
2599        {
2600            (*__dp)->__c_ = nullptr;
2601            if (--__c->end_ != __dp)
2602                memmove(__dp, __dp+1, (__c->end_ - __dp)*sizeof(__i_node*));
2603        }
2604    }
2605    __get_db()->unlock();
2606#endif
2607    return __node_holder(__cn->__upcast(), _Dp(__node_alloc(), true));
2608}
2609
2610template <class _Tp, class _Hash, class _Equal, class _Alloc>
2611template <class _Key>
2612inline
2613typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2614__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_unique(const _Key& __k) const
2615{
2616    return static_cast<size_type>(find(__k) != end());
2617}
2618
2619template <class _Tp, class _Hash, class _Equal, class _Alloc>
2620template <class _Key>
2621typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2622__hash_table<_Tp, _Hash, _Equal, _Alloc>::__count_multi(const _Key& __k) const
2623{
2624    size_type __r = 0;
2625    const_iterator __i = find(__k);
2626    if (__i != end())
2627    {
2628        const_iterator __e = end();
2629        do
2630        {
2631            ++__i;
2632            ++__r;
2633        } while (__i != __e && key_eq()(*__i, __k));
2634    }
2635    return __r;
2636}
2637
2638template <class _Tp, class _Hash, class _Equal, class _Alloc>
2639template <class _Key>
2640pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
2641     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
2642__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
2643        const _Key& __k)
2644{
2645    iterator __i = find(__k);
2646    iterator __j = __i;
2647    if (__i != end())
2648        ++__j;
2649    return pair<iterator, iterator>(__i, __j);
2650}
2651
2652template <class _Tp, class _Hash, class _Equal, class _Alloc>
2653template <class _Key>
2654pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
2655     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
2656__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_unique(
2657        const _Key& __k) const
2658{
2659    const_iterator __i = find(__k);
2660    const_iterator __j = __i;
2661    if (__i != end())
2662        ++__j;
2663    return pair<const_iterator, const_iterator>(__i, __j);
2664}
2665
2666template <class _Tp, class _Hash, class _Equal, class _Alloc>
2667template <class _Key>
2668pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator,
2669     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::iterator>
2670__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
2671        const _Key& __k)
2672{
2673    iterator __i = find(__k);
2674    iterator __j = __i;
2675    if (__i != end())
2676    {
2677        iterator __e = end();
2678        do
2679        {
2680            ++__j;
2681        } while (__j != __e && key_eq()(*__j, __k));
2682    }
2683    return pair<iterator, iterator>(__i, __j);
2684}
2685
2686template <class _Tp, class _Hash, class _Equal, class _Alloc>
2687template <class _Key>
2688pair<typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator,
2689     typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::const_iterator>
2690__hash_table<_Tp, _Hash, _Equal, _Alloc>::__equal_range_multi(
2691        const _Key& __k) const
2692{
2693    const_iterator __i = find(__k);
2694    const_iterator __j = __i;
2695    if (__i != end())
2696    {
2697        const_iterator __e = end();
2698        do
2699        {
2700            ++__j;
2701        } while (__j != __e && key_eq()(*__j, __k));
2702    }
2703    return pair<const_iterator, const_iterator>(__i, __j);
2704}
2705
2706template <class _Tp, class _Hash, class _Equal, class _Alloc>
2707void
2708__hash_table<_Tp, _Hash, _Equal, _Alloc>::swap(__hash_table& __u)
2709#if _LIBCPP_STD_VER <= 11
2710    _NOEXCEPT_(
2711        __is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value
2712        && (!allocator_traits<__pointer_allocator>::propagate_on_container_swap::value
2713              || __is_nothrow_swappable<__pointer_allocator>::value)
2714        && (!__node_traits::propagate_on_container_swap::value
2715              || __is_nothrow_swappable<__node_allocator>::value)
2716            )
2717#else
2718  _NOEXCEPT_(__is_nothrow_swappable<hasher>::value && __is_nothrow_swappable<key_equal>::value)
2719#endif
2720{
2721    _LIBCPP_ASSERT(__node_traits::propagate_on_container_swap::value ||
2722                   this->__node_alloc() == __u.__node_alloc(),
2723                   "list::swap: Either propagate_on_container_swap must be true"
2724                   " or the allocators must compare equal");
2725    {
2726    __node_pointer_pointer __npp = __bucket_list_.release();
2727    __bucket_list_.reset(__u.__bucket_list_.release());
2728    __u.__bucket_list_.reset(__npp);
2729    }
2730    _VSTD::swap(__bucket_list_.get_deleter().size(), __u.__bucket_list_.get_deleter().size());
2731    _VSTD::__swap_allocator(__bucket_list_.get_deleter().__alloc(),
2732             __u.__bucket_list_.get_deleter().__alloc());
2733    _VSTD::__swap_allocator(__node_alloc(), __u.__node_alloc());
2734    _VSTD::swap(__p1_.first().__next_, __u.__p1_.first().__next_);
2735    __p2_.swap(__u.__p2_);
2736    __p3_.swap(__u.__p3_);
2737    if (size() > 0)
2738        __bucket_list_[__constrain_hash(__p1_.first().__next_->__hash(), bucket_count())] =
2739            __p1_.first().__ptr();
2740    if (__u.size() > 0)
2741        __u.__bucket_list_[__constrain_hash(__u.__p1_.first().__next_->__hash(), __u.bucket_count())] =
2742            __u.__p1_.first().__ptr();
2743#if _LIBCPP_DEBUG_LEVEL == 2
2744    __get_db()->swap(this, &__u);
2745#endif
2746}
2747
2748template <class _Tp, class _Hash, class _Equal, class _Alloc>
2749typename __hash_table<_Tp, _Hash, _Equal, _Alloc>::size_type
2750__hash_table<_Tp, _Hash, _Equal, _Alloc>::bucket_size(size_type __n) const
2751{
2752    _LIBCPP_ASSERT(__n < bucket_count(),
2753        "unordered container::bucket_size(n) called with n >= bucket_count()");
2754    __next_pointer __np = __bucket_list_[__n];
2755    size_type __bc = bucket_count();
2756    size_type __r = 0;
2757    if (__np != nullptr)
2758    {
2759        for (__np = __np->__next_; __np != nullptr &&
2760                                   __constrain_hash(__np->__hash(), __bc) == __n;
2761                                                    __np = __np->__next_, ++__r)
2762            ;
2763    }
2764    return __r;
2765}
2766
2767template <class _Tp, class _Hash, class _Equal, class _Alloc>
2768inline _LIBCPP_INLINE_VISIBILITY
2769void
2770swap(__hash_table<_Tp, _Hash, _Equal, _Alloc>& __x,
2771     __hash_table<_Tp, _Hash, _Equal, _Alloc>& __y)
2772    _NOEXCEPT_(_NOEXCEPT_(__x.swap(__y)))
2773{
2774    __x.swap(__y);
2775}
2776
2777#if _LIBCPP_DEBUG_LEVEL == 2
2778
2779template <class _Tp, class _Hash, class _Equal, class _Alloc>
2780bool
2781__hash_table<_Tp, _Hash, _Equal, _Alloc>::__dereferenceable(const const_iterator* __i) const
2782{
2783    return __i->__node_ != nullptr;
2784}
2785
2786template <class _Tp, class _Hash, class _Equal, class _Alloc>
2787bool
2788__hash_table<_Tp, _Hash, _Equal, _Alloc>::__decrementable(const const_iterator*) const
2789{
2790    return false;
2791}
2792
2793template <class _Tp, class _Hash, class _Equal, class _Alloc>
2794bool
2795__hash_table<_Tp, _Hash, _Equal, _Alloc>::__addable(const const_iterator*, ptrdiff_t) const
2796{
2797    return false;
2798}
2799
2800template <class _Tp, class _Hash, class _Equal, class _Alloc>
2801bool
2802__hash_table<_Tp, _Hash, _Equal, _Alloc>::__subscriptable(const const_iterator*, ptrdiff_t) const
2803{
2804    return false;
2805}
2806
2807#endif  // _LIBCPP_DEBUG_LEVEL == 2
2808
2809_LIBCPP_END_NAMESPACE_STD
2810
2811_LIBCPP_POP_MACROS
2812
2813#endif  // _LIBCPP__HASH_TABLE
2814