1 // hashtable.h header -*- C++ -*-
3 // Copyright (C) 2007-2014 Free Software Foundation, Inc.
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the
7 // terms of the GNU General Public License as published by the
8 // Free Software Foundation; either version 3, or (at your option)
11 // This library is distributed in the hope that it will be useful,
12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 // GNU General Public License for more details.
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23 // <http://www.gnu.org/licenses/>.
25 /** @file bits/hashtable.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly. @headername{unordered_map, unordered_set}
31 #define _HASHTABLE_H 1
33 #pragma GCC system_header
35 #include <bits/hashtable_policy.h>
37 namespace std _GLIBCXX_VISIBILITY(default)
39 _GLIBCXX_BEGIN_NAMESPACE_VERSION
41 template<typename _Tp, typename _Hash>
43 = __not_<__and_<// Do not cache for fast hasher.
44 __is_fast_hash<_Hash>,
45 // Mandatory to have erase not throwing.
46 __detail::__is_noexcept_hash<_Tp, _Hash>>>;
49 * Primary class template _Hashtable.
51 * @ingroup hashtable-detail
53 * @tparam _Value CopyConstructible type.
55 * @tparam _Key CopyConstructible type.
57 * @tparam _Alloc An allocator type
58 * ([lib.allocator.requirements]) whose _Alloc::value_type is
59 * _Value. As a conforming extension, we allow for
60 * _Alloc::value_type != _Value.
62 * @tparam _ExtractKey Function object that takes an object of type
63 * _Value and returns a value of type _Key.
65 * @tparam _Equal Function object that takes two objects of type k
66 * and returns a bool-like value that is true if the two objects
67 * are considered equal.
69 * @tparam _H1 The hash function. A unary function object with
70 * argument type _Key and result type size_t. Return values should
71 * be distributed over the entire range [0, numeric_limits<size_t>:::max()].
73 * @tparam _H2 The range-hashing function (in the terminology of
74 * Tavori and Dreizin). A binary function object whose argument
75 * types and result type are all size_t. Given arguments r and N,
76 * the return value is in the range [0, N).
78 * @tparam _Hash The ranged hash function (Tavori and Dreizin). A
79 * binary function whose argument types are _Key and size_t and
80 * whose result type is size_t. Given arguments k and N, the
81 * return value is in the range [0, N). Default: hash(k, N) =
82 * h2(h1(k), N). If _Hash is anything other than the default, _H1
83 * and _H2 are ignored.
85 * @tparam _RehashPolicy Policy class with three members, all of
86 * which govern the bucket count. _M_next_bkt(n) returns a bucket
87 * count no smaller than n. _M_bkt_for_elements(n) returns a
88 * bucket count appropriate for an element count of n.
89 * _M_need_rehash(n_bkt, n_elt, n_ins) determines whether, if the
90 * current bucket count is n_bkt and the current element count is
91 * n_elt, we need to increase the bucket count. If so, returns
92 * make_pair(true, n), where n is the new bucket count. If not,
93 * returns make_pair(false, <anything>)
95 * @tparam _Traits Compile-time class with three boolean
96 * std::integral_constant members: __cache_hash_code, __constant_iterators,
99 * Each _Hashtable data structure has:
101 * - _Bucket[] _M_buckets
102 * - _Hash_node_base _M_before_begin
103 * - size_type _M_bucket_count
104 * - size_type _M_element_count
106 * with _Bucket being _Hash_node* and _Hash_node containing:
108 * - _Hash_node* _M_next
110 * - size_t _M_hash_code if cache_hash_code is true
112 * In terms of Standard containers the hashtable is like the aggregation of:
114 * - std::forward_list<_Node> containing the elements
115 * - std::vector<std::forward_list<_Node>::iterator> representing the buckets
117 * The non-empty buckets contain the node before the first node in the
118 * bucket. This design makes it possible to implement something like a
119 * std::forward_list::insert_after on container insertion and
120 * std::forward_list::erase_after on container erase
121 * calls. _M_before_begin is equivalent to
122 * std::forward_list::before_begin. Empty buckets contain
123 * nullptr. Note that one of the non-empty buckets contains
124 * &_M_before_begin which is not a dereferenceable node so the
125 * node pointer in a bucket shall never be dereferenced, only its
128 * Walking through a bucket's nodes requires a check on the hash code to
129 * see if each node is still in the bucket. Such a design assumes a
130 * quite efficient hash functor and is one of the reasons it is
131 * highly advisable to set __cache_hash_code to true.
133 * The container iterators are simply built from nodes. This way
134 * incrementing the iterator is perfectly efficient independent of
135 * how many empty buckets there are in the container.
137 * On insert we compute the element's hash code and use it to find the
138 * bucket index. If the element must be inserted in an empty bucket
139 * we add it at the beginning of the singly linked list and make the
140 * bucket point to _M_before_begin. The bucket that used to point to
141 * _M_before_begin, if any, is updated to point to its new before
144 * On erase, the simple iterator design requires using the hash
145 * functor to get the index of the bucket to update. For this
146 * reason, when __cache_hash_code is set to false the hash functor must
147 * not throw and this is enforced by a static assertion.
149 * Functionality is implemented by decomposition into base classes,
150 * where the derived _Hashtable class is used in _Map_base,
151 * _Insert, _Rehash_base, and _Equality base classes to access the
152 * "this" pointer. _Hashtable_base is used in the base classes as a
153 * non-recursive, fully-completed-type so that detailed nested type
154 * information, such as iterator type and node type, can be
155 * used. This is similar to the "Curiously Recurring Template
156 * Pattern" (CRTP) technique, but uses a reconstructed, not
157 * explicitly passed, template pattern.
159 * Base class templates are:
160 * - __detail::_Hashtable_base
161 * - __detail::_Map_base
162 * - __detail::_Insert
163 * - __detail::_Rehash_base
164 * - __detail::_Equality
166 template<typename _Key, typename _Value, typename _Alloc,
167 typename _ExtractKey, typename _Equal,
168 typename _H1, typename _H2, typename _Hash,
169 typename _RehashPolicy, typename _Traits>
171 : public __detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal,
172 _H1, _H2, _Hash, _Traits>,
173 public __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
174 _H1, _H2, _Hash, _RehashPolicy, _Traits>,
175 public __detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal,
176 _H1, _H2, _Hash, _RehashPolicy, _Traits>,
177 public __detail::_Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
178 _H1, _H2, _Hash, _RehashPolicy, _Traits>,
179 public __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
180 _H1, _H2, _Hash, _RehashPolicy, _Traits>,
181 private __detail::_Hashtable_alloc<
182 typename __alloctr_rebind<_Alloc,
183 __detail::_Hash_node<_Value,
184 _Traits::__hash_cached::value> >::__type>
186 using __traits_type = _Traits;
187 using __hash_cached = typename __traits_type::__hash_cached;
188 using __node_type = __detail::_Hash_node<_Value, __hash_cached::value>;
189 using __node_alloc_type =
190 typename __alloctr_rebind<_Alloc, __node_type>::__type;
192 using __hashtable_alloc = __detail::_Hashtable_alloc<__node_alloc_type>;
194 using __value_alloc_traits =
195 typename __hashtable_alloc::__value_alloc_traits;
196 using __node_alloc_traits =
197 typename __hashtable_alloc::__node_alloc_traits;
198 using __node_base = typename __hashtable_alloc::__node_base;
199 using __bucket_type = typename __hashtable_alloc::__bucket_type;
202 typedef _Key key_type;
203 typedef _Value value_type;
204 typedef _Alloc allocator_type;
205 typedef _Equal key_equal;
207 // mapped_type, if present, comes from _Map_base.
208 // hasher, if present, comes from _Hash_code_base/_Hashtable_base.
209 typedef typename __value_alloc_traits::pointer pointer;
210 typedef typename __value_alloc_traits::const_pointer const_pointer;
211 typedef value_type& reference;
212 typedef const value_type& const_reference;
215 using __rehash_type = _RehashPolicy;
216 using __rehash_state = typename __rehash_type::_State;
218 using __constant_iterators = typename __traits_type::__constant_iterators;
219 using __unique_keys = typename __traits_type::__unique_keys;
221 using __key_extract = typename std::conditional<
222 __constant_iterators::value,
224 __detail::_Select1st>::type;
226 using __hashtable_base = __detail::
227 _Hashtable_base<_Key, _Value, _ExtractKey,
228 _Equal, _H1, _H2, _Hash, _Traits>;
230 using __hash_code_base = typename __hashtable_base::__hash_code_base;
231 using __hash_code = typename __hashtable_base::__hash_code;
232 using __ireturn_type = typename __hashtable_base::__ireturn_type;
234 using __map_base = __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey,
235 _Equal, _H1, _H2, _Hash,
236 _RehashPolicy, _Traits>;
238 using __rehash_base = __detail::_Rehash_base<_Key, _Value, _Alloc,
241 _RehashPolicy, _Traits>;
243 using __eq_base = __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey,
244 _Equal, _H1, _H2, _Hash,
245 _RehashPolicy, _Traits>;
247 using __reuse_or_alloc_node_type =
248 __detail::_ReuseOrAllocNode<__node_alloc_type>;
250 // Metaprogramming for picking apart hash caching.
251 template<typename _Cond>
252 using __if_hash_cached = __or_<__not_<__hash_cached>, _Cond>;
254 template<typename _Cond>
255 using __if_hash_not_cached = __or_<__hash_cached, _Cond>;
257 // Compile-time diagnostics.
259 // _Hash_code_base has everything protected, so use this derived type to
261 struct __hash_code_base_access : __hash_code_base
262 { using __hash_code_base::_M_bucket_index; };
264 // Getting a bucket index from a node shall not throw because it is used
265 // in methods (erase, swap...) that shall not throw.
266 static_assert(noexcept(declval<const __hash_code_base_access&>()
267 ._M_bucket_index((const __node_type*)nullptr,
269 "Cache the hash code or qualify your functors involved"
270 " in hash code and bucket index computation with noexcept");
272 // Following two static assertions are necessary to guarantee
273 // that local_iterator will be default constructible.
275 // When hash codes are cached local iterator inherits from H2 functor
276 // which must then be default constructible.
277 static_assert(__if_hash_cached<is_default_constructible<_H2>>::value,
278 "Functor used to map hash code to bucket index"
279 " must be default constructible");
281 template<typename _Keya, typename _Valuea, typename _Alloca,
282 typename _ExtractKeya, typename _Equala,
283 typename _H1a, typename _H2a, typename _Hasha,
284 typename _RehashPolicya, typename _Traitsa,
286 friend struct __detail::_Map_base;
288 template<typename _Keya, typename _Valuea, typename _Alloca,
289 typename _ExtractKeya, typename _Equala,
290 typename _H1a, typename _H2a, typename _Hasha,
291 typename _RehashPolicya, typename _Traitsa>
292 friend struct __detail::_Insert_base;
294 template<typename _Keya, typename _Valuea, typename _Alloca,
295 typename _ExtractKeya, typename _Equala,
296 typename _H1a, typename _H2a, typename _Hasha,
297 typename _RehashPolicya, typename _Traitsa,
298 bool _Constant_iteratorsa, bool _Unique_keysa>
299 friend struct __detail::_Insert;
302 using size_type = typename __hashtable_base::size_type;
303 using difference_type = typename __hashtable_base::difference_type;
305 using iterator = typename __hashtable_base::iterator;
306 using const_iterator = typename __hashtable_base::const_iterator;
308 using local_iterator = typename __hashtable_base::local_iterator;
309 using const_local_iterator = typename __hashtable_base::
310 const_local_iterator;
313 __bucket_type* _M_buckets;
314 size_type _M_bucket_count;
315 __node_base _M_before_begin;
316 size_type _M_element_count;
317 _RehashPolicy _M_rehash_policy;
319 // A single bucket used when only need for 1 bucket. Especially
320 // interesting in move semantic to leave hashtable with only 1 buckets
321 // which is not allocated so that we can have those operations noexcept
323 // Note that we can't leave hashtable with 0 bucket without adding
324 // numerous checks in the code to avoid 0 modulus.
325 __bucket_type _M_single_bucket;
328 _M_uses_single_bucket(__bucket_type* __bkts) const
329 { return __builtin_expect(__bkts == &_M_single_bucket, false); }
332 _M_uses_single_bucket() const
333 { return _M_uses_single_bucket(_M_buckets); }
336 _M_base_alloc() { return *this; }
339 _M_allocate_buckets(size_type __n)
341 if (__builtin_expect(__n == 1, false))
343 _M_single_bucket = nullptr;
344 return &_M_single_bucket;
347 return __hashtable_alloc::_M_allocate_buckets(__n);
351 _M_deallocate_buckets(__bucket_type* __bkts, size_type __n)
353 if (_M_uses_single_bucket(__bkts))
356 __hashtable_alloc::_M_deallocate_buckets(__bkts, __n);
360 _M_deallocate_buckets()
361 { _M_deallocate_buckets(_M_buckets, _M_bucket_count); }
363 // Gets bucket begin, deals with the fact that non-empty buckets contain
364 // their before begin node.
366 _M_bucket_begin(size_type __bkt) const;
370 { return static_cast<__node_type*>(_M_before_begin._M_nxt); }
372 template<typename _NodeGenerator>
374 _M_assign(const _Hashtable&, const _NodeGenerator&);
377 _M_move_assign(_Hashtable&&, std::true_type);
380 _M_move_assign(_Hashtable&&, std::false_type);
386 // Constructor, destructor, assignment, swap
387 _Hashtable(size_type __bucket_hint,
388 const _H1&, const _H2&, const _Hash&,
389 const _Equal&, const _ExtractKey&,
390 const allocator_type&);
392 template<typename _InputIterator>
393 _Hashtable(_InputIterator __first, _InputIterator __last,
394 size_type __bucket_hint,
395 const _H1&, const _H2&, const _Hash&,
396 const _Equal&, const _ExtractKey&,
397 const allocator_type&);
399 _Hashtable(const _Hashtable&);
401 _Hashtable(_Hashtable&&) noexcept;
403 _Hashtable(const _Hashtable&, const allocator_type&);
405 _Hashtable(_Hashtable&&, const allocator_type&);
407 // Use delegating constructors.
409 _Hashtable(const allocator_type& __a)
410 : _Hashtable(10, _H1(), _H2(), _Hash(), key_equal(),
411 __key_extract(), __a)
415 _Hashtable(size_type __n = 10,
416 const _H1& __hf = _H1(),
417 const key_equal& __eql = key_equal(),
418 const allocator_type& __a = allocator_type())
419 : _Hashtable(__n, __hf, _H2(), _Hash(), __eql,
420 __key_extract(), __a)
423 template<typename _InputIterator>
424 _Hashtable(_InputIterator __f, _InputIterator __l,
426 const _H1& __hf = _H1(),
427 const key_equal& __eql = key_equal(),
428 const allocator_type& __a = allocator_type())
429 : _Hashtable(__f, __l, __n, __hf, _H2(), _Hash(), __eql,
430 __key_extract(), __a)
433 _Hashtable(initializer_list<value_type> __l,
435 const _H1& __hf = _H1(),
436 const key_equal& __eql = key_equal(),
437 const allocator_type& __a = allocator_type())
438 : _Hashtable(__l.begin(), __l.end(), __n, __hf, _H2(), _Hash(), __eql,
439 __key_extract(), __a)
443 operator=(const _Hashtable& __ht);
446 operator=(_Hashtable&& __ht)
447 noexcept(__node_alloc_traits::_S_nothrow_move())
449 constexpr bool __move_storage =
450 __node_alloc_traits::_S_propagate_on_move_assign()
451 || __node_alloc_traits::_S_always_equal();
452 _M_move_assign(std::move(__ht),
453 integral_constant<bool, __move_storage>());
458 operator=(initializer_list<value_type> __l)
460 __reuse_or_alloc_node_type __roan(_M_begin(), *this);
461 _M_before_begin._M_nxt = nullptr;
463 this->_M_insert_range(__l.begin(), __l.end(), __roan);
467 ~_Hashtable() noexcept;
471 noexcept(__node_alloc_traits::_S_nothrow_swap());
473 // Basic container operations
476 { return iterator(_M_begin()); }
479 begin() const noexcept
480 { return const_iterator(_M_begin()); }
484 { return iterator(nullptr); }
488 { return const_iterator(nullptr); }
491 cbegin() const noexcept
492 { return const_iterator(_M_begin()); }
495 cend() const noexcept
496 { return const_iterator(nullptr); }
499 size() const noexcept
500 { return _M_element_count; }
503 empty() const noexcept
504 { return size() == 0; }
507 get_allocator() const noexcept
508 { return allocator_type(this->_M_node_allocator()); }
511 max_size() const noexcept
512 { return __node_alloc_traits::max_size(this->_M_node_allocator()); }
517 { return this->_M_eq(); }
519 // hash_function, if present, comes from _Hash_code_base.
523 bucket_count() const noexcept
524 { return _M_bucket_count; }
527 max_bucket_count() const noexcept
528 { return max_size(); }
531 bucket_size(size_type __n) const
532 { return std::distance(begin(__n), end(__n)); }
535 bucket(const key_type& __k) const
536 { return _M_bucket_index(__k, this->_M_hash_code(__k)); }
541 return local_iterator(*this, _M_bucket_begin(__n),
542 __n, _M_bucket_count);
547 { return local_iterator(*this, nullptr, __n, _M_bucket_count); }
550 begin(size_type __n) const
552 return const_local_iterator(*this, _M_bucket_begin(__n),
553 __n, _M_bucket_count);
557 end(size_type __n) const
558 { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); }
562 cbegin(size_type __n) const
564 return const_local_iterator(*this, _M_bucket_begin(__n),
565 __n, _M_bucket_count);
569 cend(size_type __n) const
570 { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); }
573 load_factor() const noexcept
575 return static_cast<float>(size()) / static_cast<float>(bucket_count());
578 // max_load_factor, if present, comes from _Rehash_base.
580 // Generalization of max_load_factor. Extension, not found in
581 // TR1. Only useful if _RehashPolicy is something other than
584 __rehash_policy() const
585 { return _M_rehash_policy; }
588 __rehash_policy(const _RehashPolicy&);
592 find(const key_type& __k);
595 find(const key_type& __k) const;
598 count(const key_type& __k) const;
600 std::pair<iterator, iterator>
601 equal_range(const key_type& __k);
603 std::pair<const_iterator, const_iterator>
604 equal_range(const key_type& __k) const;
607 // Bucket index computation helpers.
609 _M_bucket_index(__node_type* __n) const noexcept
610 { return __hash_code_base::_M_bucket_index(__n, _M_bucket_count); }
613 _M_bucket_index(const key_type& __k, __hash_code __c) const
614 { return __hash_code_base::_M_bucket_index(__k, __c, _M_bucket_count); }
616 // Find and insert helper functions and types
617 // Find the node before the one matching the criteria.
619 _M_find_before_node(size_type, const key_type&, __hash_code) const;
622 _M_find_node(size_type __bkt, const key_type& __key,
623 __hash_code __c) const
625 __node_base* __before_n = _M_find_before_node(__bkt, __key, __c);
627 return static_cast<__node_type*>(__before_n->_M_nxt);
631 // Insert a node at the beginning of a bucket.
633 _M_insert_bucket_begin(size_type, __node_type*);
635 // Remove the bucket first node
637 _M_remove_bucket_begin(size_type __bkt, __node_type* __next_n,
638 size_type __next_bkt);
640 // Get the node before __n in the bucket __bkt
642 _M_get_previous_node(size_type __bkt, __node_base* __n);
644 // Insert node with hash code __code, in bucket bkt if no rehash (assumes
645 // no element with its key already present). Take ownership of the node,
646 // deallocate it on exception.
648 _M_insert_unique_node(size_type __bkt, __hash_code __code,
651 // Insert node with hash code __code. Take ownership of the node,
652 // deallocate it on exception.
654 _M_insert_multi_node(__node_type* __hint,
655 __hash_code __code, __node_type* __n);
657 template<typename... _Args>
658 std::pair<iterator, bool>
659 _M_emplace(std::true_type, _Args&&... __args);
661 template<typename... _Args>
663 _M_emplace(std::false_type __uk, _Args&&... __args)
664 { return _M_emplace(cend(), __uk, std::forward<_Args>(__args)...); }
666 // Emplace with hint, useless when keys are unique.
667 template<typename... _Args>
669 _M_emplace(const_iterator, std::true_type __uk, _Args&&... __args)
670 { return _M_emplace(__uk, std::forward<_Args>(__args)...).first; }
672 template<typename... _Args>
674 _M_emplace(const_iterator, std::false_type, _Args&&... __args);
676 template<typename _Arg, typename _NodeGenerator>
677 std::pair<iterator, bool>
678 _M_insert(_Arg&&, const _NodeGenerator&, std::true_type);
680 template<typename _Arg, typename _NodeGenerator>
682 _M_insert(_Arg&& __arg, const _NodeGenerator& __node_gen,
683 std::false_type __uk)
685 return _M_insert(cend(), std::forward<_Arg>(__arg), __node_gen,
689 // Insert with hint, not used when keys are unique.
690 template<typename _Arg, typename _NodeGenerator>
692 _M_insert(const_iterator, _Arg&& __arg, const _NodeGenerator& __node_gen,
696 _M_insert(std::forward<_Arg>(__arg), __node_gen, __uk).first;
699 // Insert with hint when keys are not unique.
700 template<typename _Arg, typename _NodeGenerator>
702 _M_insert(const_iterator, _Arg&&, const _NodeGenerator&, std::false_type);
705 _M_erase(std::true_type, const key_type&);
708 _M_erase(std::false_type, const key_type&);
711 _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n);
715 template<typename... _Args>
717 emplace(_Args&&... __args)
718 { return _M_emplace(__unique_keys(), std::forward<_Args>(__args)...); }
720 template<typename... _Args>
722 emplace_hint(const_iterator __hint, _Args&&... __args)
724 return _M_emplace(__hint, __unique_keys(),
725 std::forward<_Args>(__args)...);
728 // Insert member functions via inheritance.
732 erase(const_iterator);
737 { return erase(const_iterator(__it)); }
740 erase(const key_type& __k)
741 { return _M_erase(__unique_keys(), __k); }
744 erase(const_iterator, const_iterator);
749 // Set number of buckets to be appropriate for container of n element.
750 void rehash(size_type __n);
753 // reserve, if present, comes from _Rehash_base.
756 // Helper rehash method used when keys are unique.
757 void _M_rehash_aux(size_type __n, std::true_type);
759 // Helper rehash method used when keys can be non-unique.
760 void _M_rehash_aux(size_type __n, std::false_type);
762 // Unconditionally change size of bucket array to n, restore
763 // hash policy state to __state on exception.
764 void _M_rehash(size_type __n, const __rehash_state& __state);
768 // Definitions of class template _Hashtable's out-of-line member functions.
769 template<typename _Key, typename _Value,
770 typename _Alloc, typename _ExtractKey, typename _Equal,
771 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
773 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
774 _Equal, _H1, _H2, _Hash, _RehashPolicy,
775 _Traits>::__node_type*
776 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
777 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
778 _M_bucket_begin(size_type __bkt) const
780 __node_base* __n = _M_buckets[__bkt];
781 return __n ? static_cast<__node_type*>(__n->_M_nxt) : nullptr;
784 template<typename _Key, typename _Value,
785 typename _Alloc, typename _ExtractKey, typename _Equal,
786 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
788 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
789 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
790 _Hashtable(size_type __bucket_hint,
791 const _H1& __h1, const _H2& __h2, const _Hash& __h,
792 const _Equal& __eq, const _ExtractKey& __exk,
793 const allocator_type& __a)
794 : __hashtable_base(__exk, __h1, __h2, __h, __eq),
797 __hashtable_alloc(__node_alloc_type(__a)),
801 _M_bucket_count = _M_rehash_policy._M_next_bkt(__bucket_hint);
802 _M_buckets = _M_allocate_buckets(_M_bucket_count);
805 template<typename _Key, typename _Value,
806 typename _Alloc, typename _ExtractKey, typename _Equal,
807 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
809 template<typename _InputIterator>
810 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
811 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
812 _Hashtable(_InputIterator __f, _InputIterator __l,
813 size_type __bucket_hint,
814 const _H1& __h1, const _H2& __h2, const _Hash& __h,
815 const _Equal& __eq, const _ExtractKey& __exk,
816 const allocator_type& __a)
817 : __hashtable_base(__exk, __h1, __h2, __h, __eq),
820 __hashtable_alloc(__node_alloc_type(__a)),
824 auto __nb_elems = __detail::__distance_fw(__f, __l);
826 _M_rehash_policy._M_next_bkt(
827 std::max(_M_rehash_policy._M_bkt_for_elements(__nb_elems),
830 _M_buckets = _M_allocate_buckets(_M_bucket_count);
833 for (; __f != __l; ++__f)
839 _M_deallocate_buckets();
840 __throw_exception_again;
844 template<typename _Key, typename _Value,
845 typename _Alloc, typename _ExtractKey, typename _Equal,
846 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
848 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
849 _H1, _H2, _Hash, _RehashPolicy, _Traits>&
850 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
851 _H1, _H2, _Hash, _RehashPolicy, _Traits>::operator=(
852 const _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
853 _H1, _H2, _Hash, _RehashPolicy, _Traits>& __ht)
858 if (__node_alloc_traits::_S_propagate_on_copy_assign())
860 auto& __this_alloc = this->_M_node_allocator();
861 auto& __that_alloc = __ht._M_node_allocator();
862 if (!__node_alloc_traits::_S_always_equal()
863 && __this_alloc != __that_alloc)
865 // Replacement allocator cannot free existing storage.
866 this->_M_deallocate_nodes(_M_begin());
867 _M_before_begin._M_nxt = nullptr;
868 _M_deallocate_buckets();
869 _M_buckets = nullptr;
870 std::__alloc_on_copy(__this_alloc, __that_alloc);
871 __hashtable_base::operator=(__ht);
872 _M_bucket_count = __ht._M_bucket_count;
873 _M_element_count = __ht._M_element_count;
874 _M_rehash_policy = __ht._M_rehash_policy;
878 [this](const __node_type* __n)
879 { return this->_M_allocate_node(__n->_M_v()); });
883 // _M_assign took care of deallocating all memory. Now we
884 // must make sure this instance remains in a usable state.
886 __throw_exception_again;
890 std::__alloc_on_copy(__this_alloc, __that_alloc);
893 // Reuse allocated buckets and nodes.
894 __bucket_type* __former_buckets = nullptr;
895 std::size_t __former_bucket_count = _M_bucket_count;
896 const __rehash_state& __former_state = _M_rehash_policy._M_state();
898 if (_M_bucket_count != __ht._M_bucket_count)
900 __former_buckets = _M_buckets;
901 _M_buckets = _M_allocate_buckets(__ht._M_bucket_count);
902 _M_bucket_count = __ht._M_bucket_count;
905 __builtin_memset(_M_buckets, 0,
906 _M_bucket_count * sizeof(__bucket_type));
910 __hashtable_base::operator=(__ht);
911 _M_element_count = __ht._M_element_count;
912 _M_rehash_policy = __ht._M_rehash_policy;
913 __reuse_or_alloc_node_type __roan(_M_begin(), *this);
914 _M_before_begin._M_nxt = nullptr;
916 [&__roan](const __node_type* __n)
917 { return __roan(__n->_M_v()); });
918 if (__former_buckets)
919 _M_deallocate_buckets(__former_buckets, __former_bucket_count);
923 if (__former_buckets)
925 // Restore previous buckets.
926 _M_deallocate_buckets();
927 _M_rehash_policy._M_reset(__former_state);
928 _M_buckets = __former_buckets;
929 _M_bucket_count = __former_bucket_count;
931 __builtin_memset(_M_buckets, 0,
932 _M_bucket_count * sizeof(__bucket_type));
933 __throw_exception_again;
938 template<typename _Key, typename _Value,
939 typename _Alloc, typename _ExtractKey, typename _Equal,
940 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
942 template<typename _NodeGenerator>
944 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
945 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
946 _M_assign(const _Hashtable& __ht, const _NodeGenerator& __node_gen)
948 __bucket_type* __buckets = nullptr;
950 _M_buckets = __buckets = _M_allocate_buckets(_M_bucket_count);
954 if (!__ht._M_before_begin._M_nxt)
957 // First deal with the special first node pointed to by
959 __node_type* __ht_n = __ht._M_begin();
960 __node_type* __this_n = __node_gen(__ht_n);
961 this->_M_copy_code(__this_n, __ht_n);
962 _M_before_begin._M_nxt = __this_n;
963 _M_buckets[_M_bucket_index(__this_n)] = &_M_before_begin;
965 // Then deal with other nodes.
966 __node_base* __prev_n = __this_n;
967 for (__ht_n = __ht_n->_M_next(); __ht_n; __ht_n = __ht_n->_M_next())
969 __this_n = __node_gen(__ht_n);
970 __prev_n->_M_nxt = __this_n;
971 this->_M_copy_code(__this_n, __ht_n);
972 size_type __bkt = _M_bucket_index(__this_n);
973 if (!_M_buckets[__bkt])
974 _M_buckets[__bkt] = __prev_n;
982 _M_deallocate_buckets();
983 __throw_exception_again;
987 template<typename _Key, typename _Value,
988 typename _Alloc, typename _ExtractKey, typename _Equal,
989 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
992 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
993 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
996 _M_rehash_policy._M_reset();
998 _M_single_bucket = nullptr;
999 _M_buckets = &_M_single_bucket;
1000 _M_before_begin._M_nxt = nullptr;
1001 _M_element_count = 0;
1004 template<typename _Key, typename _Value,
1005 typename _Alloc, typename _ExtractKey, typename _Equal,
1006 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1009 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1010 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1011 _M_move_assign(_Hashtable&& __ht, std::true_type)
1013 this->_M_deallocate_nodes(_M_begin());
1014 _M_deallocate_buckets();
1015 __hashtable_base::operator=(std::move(__ht));
1016 _M_rehash_policy = __ht._M_rehash_policy;
1017 if (!__ht._M_uses_single_bucket())
1018 _M_buckets = __ht._M_buckets;
1021 _M_buckets = &_M_single_bucket;
1022 _M_single_bucket = __ht._M_single_bucket;
1024 _M_bucket_count = __ht._M_bucket_count;
1025 _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt;
1026 _M_element_count = __ht._M_element_count;
1027 std::__alloc_on_move(this->_M_node_allocator(), __ht._M_node_allocator());
1029 // Fix buckets containing the _M_before_begin pointers that can't be
1032 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
1036 template<typename _Key, typename _Value,
1037 typename _Alloc, typename _ExtractKey, typename _Equal,
1038 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1041 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1042 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1043 _M_move_assign(_Hashtable&& __ht, std::false_type)
1045 if (__ht._M_node_allocator() == this->_M_node_allocator())
1046 _M_move_assign(std::move(__ht), std::true_type());
1049 // Can't move memory, move elements then.
1050 __bucket_type* __former_buckets = nullptr;
1051 size_type __former_bucket_count = _M_bucket_count;
1052 const __rehash_state& __former_state = _M_rehash_policy._M_state();
1054 if (_M_bucket_count != __ht._M_bucket_count)
1056 __former_buckets = _M_buckets;
1057 _M_buckets = _M_allocate_buckets(__ht._M_bucket_count);
1058 _M_bucket_count = __ht._M_bucket_count;
1061 __builtin_memset(_M_buckets, 0,
1062 _M_bucket_count * sizeof(__bucket_type));
1066 __hashtable_base::operator=(std::move(__ht));
1067 _M_element_count = __ht._M_element_count;
1068 _M_rehash_policy = __ht._M_rehash_policy;
1069 __reuse_or_alloc_node_type __roan(_M_begin(), *this);
1070 _M_before_begin._M_nxt = nullptr;
1072 [&__roan](__node_type* __n)
1073 { return __roan(std::move_if_noexcept(__n->_M_v())); });
1078 if (__former_buckets)
1080 _M_deallocate_buckets();
1081 _M_rehash_policy._M_reset(__former_state);
1082 _M_buckets = __former_buckets;
1083 _M_bucket_count = __former_bucket_count;
1085 __builtin_memset(_M_buckets, 0,
1086 _M_bucket_count * sizeof(__bucket_type));
1087 __throw_exception_again;
1092 template<typename _Key, typename _Value,
1093 typename _Alloc, typename _ExtractKey, typename _Equal,
1094 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1096 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1097 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1098 _Hashtable(const _Hashtable& __ht)
1099 : __hashtable_base(__ht),
1101 __rehash_base(__ht),
1103 __node_alloc_traits::_S_select_on_copy(__ht._M_node_allocator())),
1105 _M_bucket_count(__ht._M_bucket_count),
1106 _M_element_count(__ht._M_element_count),
1107 _M_rehash_policy(__ht._M_rehash_policy)
1110 [this](const __node_type* __n)
1111 { return this->_M_allocate_node(__n->_M_v()); });
1114 template<typename _Key, typename _Value,
1115 typename _Alloc, typename _ExtractKey, typename _Equal,
1116 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1118 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1119 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1120 _Hashtable(_Hashtable&& __ht) noexcept
1121 : __hashtable_base(__ht),
1123 __rehash_base(__ht),
1124 __hashtable_alloc(std::move(__ht._M_base_alloc())),
1125 _M_buckets(__ht._M_buckets),
1126 _M_bucket_count(__ht._M_bucket_count),
1127 _M_before_begin(__ht._M_before_begin._M_nxt),
1128 _M_element_count(__ht._M_element_count),
1129 _M_rehash_policy(__ht._M_rehash_policy)
1131 // Update, if necessary, buckets if __ht is using its single bucket.
1132 if (__ht._M_uses_single_bucket())
1134 _M_buckets = &_M_single_bucket;
1135 _M_single_bucket = __ht._M_single_bucket;
1138 // Update, if necessary, bucket pointing to before begin that hasn't
1141 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
1146 template<typename _Key, typename _Value,
1147 typename _Alloc, typename _ExtractKey, typename _Equal,
1148 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1150 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1151 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1152 _Hashtable(const _Hashtable& __ht, const allocator_type& __a)
1153 : __hashtable_base(__ht),
1155 __rehash_base(__ht),
1156 __hashtable_alloc(__node_alloc_type(__a)),
1158 _M_bucket_count(__ht._M_bucket_count),
1159 _M_element_count(__ht._M_element_count),
1160 _M_rehash_policy(__ht._M_rehash_policy)
1163 [this](const __node_type* __n)
1164 { return this->_M_allocate_node(__n->_M_v()); });
1167 template<typename _Key, typename _Value,
1168 typename _Alloc, typename _ExtractKey, typename _Equal,
1169 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1171 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1172 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1173 _Hashtable(_Hashtable&& __ht, const allocator_type& __a)
1174 : __hashtable_base(__ht),
1176 __rehash_base(__ht),
1177 __hashtable_alloc(__node_alloc_type(__a)),
1179 _M_bucket_count(__ht._M_bucket_count),
1180 _M_element_count(__ht._M_element_count),
1181 _M_rehash_policy(__ht._M_rehash_policy)
1183 if (__ht._M_node_allocator() == this->_M_node_allocator())
1185 if (__ht._M_uses_single_bucket())
1187 _M_buckets = &_M_single_bucket;
1188 _M_single_bucket = __ht._M_single_bucket;
1191 _M_buckets = __ht._M_buckets;
1193 _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt;
1194 // Update, if necessary, bucket pointing to before begin that hasn't
1197 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
1203 [this](__node_type* __n)
1205 return this->_M_allocate_node(
1206 std::move_if_noexcept(__n->_M_v()));
1212 template<typename _Key, typename _Value,
1213 typename _Alloc, typename _ExtractKey, typename _Equal,
1214 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1216 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1217 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1218 ~_Hashtable() noexcept
1222 _M_deallocate_buckets();
1225 template<typename _Key, typename _Value,
1226 typename _Alloc, typename _ExtractKey, typename _Equal,
1227 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1230 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1231 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1232 swap(_Hashtable& __x)
1233 noexcept(__node_alloc_traits::_S_nothrow_swap())
1235 // The only base class with member variables is hash_code_base.
1236 // We define _Hash_code_base::_M_swap because different
1237 // specializations have different members.
1240 std::__alloc_on_swap(this->_M_node_allocator(), __x._M_node_allocator());
1241 std::swap(_M_rehash_policy, __x._M_rehash_policy);
1243 // Deal properly with potentially moved instances.
1244 if (this->_M_uses_single_bucket())
1246 if (!__x._M_uses_single_bucket())
1248 _M_buckets = __x._M_buckets;
1249 __x._M_buckets = &__x._M_single_bucket;
1252 else if (__x._M_uses_single_bucket())
1254 __x._M_buckets = _M_buckets;
1255 _M_buckets = &_M_single_bucket;
1258 std::swap(_M_buckets, __x._M_buckets);
1260 std::swap(_M_bucket_count, __x._M_bucket_count);
1261 std::swap(_M_before_begin._M_nxt, __x._M_before_begin._M_nxt);
1262 std::swap(_M_element_count, __x._M_element_count);
1263 std::swap(_M_single_bucket, __x._M_single_bucket);
1265 // Fix buckets containing the _M_before_begin pointers that can't be
1268 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
1271 __x._M_buckets[__x._M_bucket_index(__x._M_begin())]
1272 = &__x._M_before_begin;
1275 template<typename _Key, typename _Value,
1276 typename _Alloc, typename _ExtractKey, typename _Equal,
1277 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1280 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1281 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1282 __rehash_policy(const _RehashPolicy& __pol)
1285 __pol._M_need_rehash(_M_bucket_count, _M_element_count, 0);
1286 if (__do_rehash.first)
1287 _M_rehash(__do_rehash.second, _M_rehash_policy._M_state());
1288 _M_rehash_policy = __pol;
1291 template<typename _Key, typename _Value,
1292 typename _Alloc, typename _ExtractKey, typename _Equal,
1293 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1295 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1296 _H1, _H2, _Hash, _RehashPolicy,
1298 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1299 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1300 find(const key_type& __k)
1302 __hash_code __code = this->_M_hash_code(__k);
1303 std::size_t __n = _M_bucket_index(__k, __code);
1304 __node_type* __p = _M_find_node(__n, __k, __code);
1305 return __p ? iterator(__p) : end();
1308 template<typename _Key, typename _Value,
1309 typename _Alloc, typename _ExtractKey, typename _Equal,
1310 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1312 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1313 _H1, _H2, _Hash, _RehashPolicy,
1314 _Traits>::const_iterator
1315 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1316 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1317 find(const key_type& __k) const
1319 __hash_code __code = this->_M_hash_code(__k);
1320 std::size_t __n = _M_bucket_index(__k, __code);
1321 __node_type* __p = _M_find_node(__n, __k, __code);
1322 return __p ? const_iterator(__p) : end();
1325 template<typename _Key, typename _Value,
1326 typename _Alloc, typename _ExtractKey, typename _Equal,
1327 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1329 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1330 _H1, _H2, _Hash, _RehashPolicy,
1332 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1333 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1334 count(const key_type& __k) const
1336 __hash_code __code = this->_M_hash_code(__k);
1337 std::size_t __n = _M_bucket_index(__k, __code);
1338 __node_type* __p = _M_bucket_begin(__n);
1342 std::size_t __result = 0;
1343 for (;; __p = __p->_M_next())
1345 if (this->_M_equals(__k, __code, __p))
1348 // All equivalent values are next to each other, if we
1349 // found a non-equivalent value after an equivalent one it
1350 // means that we won't find any new equivalent value.
1352 if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n)
1358 template<typename _Key, typename _Value,
1359 typename _Alloc, typename _ExtractKey, typename _Equal,
1360 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1362 std::pair<typename _Hashtable<_Key, _Value, _Alloc,
1363 _ExtractKey, _Equal, _H1,
1364 _H2, _Hash, _RehashPolicy,
1366 typename _Hashtable<_Key, _Value, _Alloc,
1367 _ExtractKey, _Equal, _H1,
1368 _H2, _Hash, _RehashPolicy,
1370 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1371 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1372 equal_range(const key_type& __k)
1374 __hash_code __code = this->_M_hash_code(__k);
1375 std::size_t __n = _M_bucket_index(__k, __code);
1376 __node_type* __p = _M_find_node(__n, __k, __code);
1380 __node_type* __p1 = __p->_M_next();
1381 while (__p1 && _M_bucket_index(__p1) == __n
1382 && this->_M_equals(__k, __code, __p1))
1383 __p1 = __p1->_M_next();
1385 return std::make_pair(iterator(__p), iterator(__p1));
1388 return std::make_pair(end(), end());
1391 template<typename _Key, typename _Value,
1392 typename _Alloc, typename _ExtractKey, typename _Equal,
1393 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1395 std::pair<typename _Hashtable<_Key, _Value, _Alloc,
1396 _ExtractKey, _Equal, _H1,
1397 _H2, _Hash, _RehashPolicy,
1398 _Traits>::const_iterator,
1399 typename _Hashtable<_Key, _Value, _Alloc,
1400 _ExtractKey, _Equal, _H1,
1401 _H2, _Hash, _RehashPolicy,
1402 _Traits>::const_iterator>
1403 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1404 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1405 equal_range(const key_type& __k) const
1407 __hash_code __code = this->_M_hash_code(__k);
1408 std::size_t __n = _M_bucket_index(__k, __code);
1409 __node_type* __p = _M_find_node(__n, __k, __code);
1413 __node_type* __p1 = __p->_M_next();
1414 while (__p1 && _M_bucket_index(__p1) == __n
1415 && this->_M_equals(__k, __code, __p1))
1416 __p1 = __p1->_M_next();
1418 return std::make_pair(const_iterator(__p), const_iterator(__p1));
1421 return std::make_pair(end(), end());
1424 // Find the node whose key compares equal to k in the bucket n.
1425 // Return nullptr if no node is found.
1426 template<typename _Key, typename _Value,
1427 typename _Alloc, typename _ExtractKey, typename _Equal,
1428 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1430 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
1431 _Equal, _H1, _H2, _Hash, _RehashPolicy,
1432 _Traits>::__node_base*
1433 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1434 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1435 _M_find_before_node(size_type __n, const key_type& __k,
1436 __hash_code __code) const
1438 __node_base* __prev_p = _M_buckets[__n];
1442 for (__node_type* __p = static_cast<__node_type*>(__prev_p->_M_nxt);;
1443 __p = __p->_M_next())
1445 if (this->_M_equals(__k, __code, __p))
1448 if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n)
1455 template<typename _Key, typename _Value,
1456 typename _Alloc, typename _ExtractKey, typename _Equal,
1457 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1460 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1461 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1462 _M_insert_bucket_begin(size_type __bkt, __node_type* __node)
1464 if (_M_buckets[__bkt])
1466 // Bucket is not empty, we just need to insert the new node
1467 // after the bucket before begin.
1468 __node->_M_nxt = _M_buckets[__bkt]->_M_nxt;
1469 _M_buckets[__bkt]->_M_nxt = __node;
1473 // The bucket is empty, the new node is inserted at the
1474 // beginning of the singly-linked list and the bucket will
1475 // contain _M_before_begin pointer.
1476 __node->_M_nxt = _M_before_begin._M_nxt;
1477 _M_before_begin._M_nxt = __node;
1479 // We must update former begin bucket that is pointing to
1481 _M_buckets[_M_bucket_index(__node->_M_next())] = __node;
1482 _M_buckets[__bkt] = &_M_before_begin;
1486 template<typename _Key, typename _Value,
1487 typename _Alloc, typename _ExtractKey, typename _Equal,
1488 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1491 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1492 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1493 _M_remove_bucket_begin(size_type __bkt, __node_type* __next,
1494 size_type __next_bkt)
1496 if (!__next || __next_bkt != __bkt)
1498 // Bucket is now empty
1499 // First update next bucket if any
1501 _M_buckets[__next_bkt] = _M_buckets[__bkt];
1503 // Second update before begin node if necessary
1504 if (&_M_before_begin == _M_buckets[__bkt])
1505 _M_before_begin._M_nxt = __next;
1506 _M_buckets[__bkt] = nullptr;
1510 template<typename _Key, typename _Value,
1511 typename _Alloc, typename _ExtractKey, typename _Equal,
1512 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1514 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
1515 _Equal, _H1, _H2, _Hash, _RehashPolicy,
1516 _Traits>::__node_base*
1517 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1518 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1519 _M_get_previous_node(size_type __bkt, __node_base* __n)
1521 __node_base* __prev_n = _M_buckets[__bkt];
1522 while (__prev_n->_M_nxt != __n)
1523 __prev_n = __prev_n->_M_nxt;
1527 template<typename _Key, typename _Value,
1528 typename _Alloc, typename _ExtractKey, typename _Equal,
1529 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1531 template<typename... _Args>
1532 std::pair<typename _Hashtable<_Key, _Value, _Alloc,
1533 _ExtractKey, _Equal, _H1,
1534 _H2, _Hash, _RehashPolicy,
1535 _Traits>::iterator, bool>
1536 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1537 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1538 _M_emplace(std::true_type, _Args&&... __args)
1540 // First build the node to get access to the hash code
1541 __node_type* __node = this->_M_allocate_node(std::forward<_Args>(__args)...);
1542 const key_type& __k = this->_M_extract()(__node->_M_v());
1546 __code = this->_M_hash_code(__k);
1550 this->_M_deallocate_node(__node);
1551 __throw_exception_again;
1554 size_type __bkt = _M_bucket_index(__k, __code);
1555 if (__node_type* __p = _M_find_node(__bkt, __k, __code))
1557 // There is already an equivalent node, no insertion
1558 this->_M_deallocate_node(__node);
1559 return std::make_pair(iterator(__p), false);
1563 return std::make_pair(_M_insert_unique_node(__bkt, __code, __node),
1567 template<typename _Key, typename _Value,
1568 typename _Alloc, typename _ExtractKey, typename _Equal,
1569 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1571 template<typename... _Args>
1572 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1573 _H1, _H2, _Hash, _RehashPolicy,
1575 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1576 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1577 _M_emplace(const_iterator __hint, std::false_type, _Args&&... __args)
1579 // First build the node to get its hash code.
1580 __node_type* __node =
1581 this->_M_allocate_node(std::forward<_Args>(__args)...);
1586 __code = this->_M_hash_code(this->_M_extract()(__node->_M_v()));
1590 this->_M_deallocate_node(__node);
1591 __throw_exception_again;
1594 return _M_insert_multi_node(__hint._M_cur, __code, __node);
1597 template<typename _Key, typename _Value,
1598 typename _Alloc, typename _ExtractKey, typename _Equal,
1599 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1601 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1602 _H1, _H2, _Hash, _RehashPolicy,
1604 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1605 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1606 _M_insert_unique_node(size_type __bkt, __hash_code __code,
1607 __node_type* __node)
1609 const __rehash_state& __saved_state = _M_rehash_policy._M_state();
1610 std::pair<bool, std::size_t> __do_rehash
1611 = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 1);
1615 if (__do_rehash.first)
1617 _M_rehash(__do_rehash.second, __saved_state);
1618 __bkt = _M_bucket_index(this->_M_extract()(__node->_M_v()), __code);
1621 this->_M_store_code(__node, __code);
1623 // Always insert at the beginning of the bucket.
1624 _M_insert_bucket_begin(__bkt, __node);
1626 return iterator(__node);
1630 this->_M_deallocate_node(__node);
1631 __throw_exception_again;
1635 // Insert node, in bucket bkt if no rehash (assumes no element with its key
1636 // already present). Take ownership of the node, deallocate it on exception.
1637 template<typename _Key, typename _Value,
1638 typename _Alloc, typename _ExtractKey, typename _Equal,
1639 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1641 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1642 _H1, _H2, _Hash, _RehashPolicy,
1644 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1645 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1646 _M_insert_multi_node(__node_type* __hint, __hash_code __code,
1647 __node_type* __node)
1649 const __rehash_state& __saved_state = _M_rehash_policy._M_state();
1650 std::pair<bool, std::size_t> __do_rehash
1651 = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 1);
1655 if (__do_rehash.first)
1656 _M_rehash(__do_rehash.second, __saved_state);
1658 this->_M_store_code(__node, __code);
1659 const key_type& __k = this->_M_extract()(__node->_M_v());
1660 size_type __bkt = _M_bucket_index(__k, __code);
1662 // Find the node before an equivalent one or use hint if it exists and
1663 // if it is equivalent.
1665 = __builtin_expect(__hint != nullptr, false)
1666 && this->_M_equals(__k, __code, __hint)
1668 : _M_find_before_node(__bkt, __k, __code);
1671 // Insert after the node before the equivalent one.
1672 __node->_M_nxt = __prev->_M_nxt;
1673 __prev->_M_nxt = __node;
1674 if (__builtin_expect(__prev == __hint, false))
1675 // hint might be the last bucket node, in this case we need to
1676 // update next bucket.
1678 && !this->_M_equals(__k, __code, __node->_M_next()))
1680 size_type __next_bkt = _M_bucket_index(__node->_M_next());
1681 if (__next_bkt != __bkt)
1682 _M_buckets[__next_bkt] = __node;
1686 // The inserted node has no equivalent in the
1687 // hashtable. We must insert the new node at the
1688 // beginning of the bucket to preserve equivalent
1689 // elements' relative positions.
1690 _M_insert_bucket_begin(__bkt, __node);
1692 return iterator(__node);
1696 this->_M_deallocate_node(__node);
1697 __throw_exception_again;
1701 // Insert v if no element with its key is already present.
1702 template<typename _Key, typename _Value,
1703 typename _Alloc, typename _ExtractKey, typename _Equal,
1704 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1706 template<typename _Arg, typename _NodeGenerator>
1707 std::pair<typename _Hashtable<_Key, _Value, _Alloc,
1708 _ExtractKey, _Equal, _H1,
1709 _H2, _Hash, _RehashPolicy,
1710 _Traits>::iterator, bool>
1711 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1712 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1713 _M_insert(_Arg&& __v, const _NodeGenerator& __node_gen, std::true_type)
1715 const key_type& __k = this->_M_extract()(__v);
1716 __hash_code __code = this->_M_hash_code(__k);
1717 size_type __bkt = _M_bucket_index(__k, __code);
1719 __node_type* __n = _M_find_node(__bkt, __k, __code);
1721 return std::make_pair(iterator(__n), false);
1723 __n = __node_gen(std::forward<_Arg>(__v));
1724 return std::make_pair(_M_insert_unique_node(__bkt, __code, __n), true);
1727 // Insert v unconditionally.
1728 template<typename _Key, typename _Value,
1729 typename _Alloc, typename _ExtractKey, typename _Equal,
1730 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1732 template<typename _Arg, typename _NodeGenerator>
1733 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1734 _H1, _H2, _Hash, _RehashPolicy,
1736 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1737 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1738 _M_insert(const_iterator __hint, _Arg&& __v,
1739 const _NodeGenerator& __node_gen,
1742 // First compute the hash code so that we don't do anything if it
1744 __hash_code __code = this->_M_hash_code(this->_M_extract()(__v));
1746 // Second allocate new node so that we don't rehash if it throws.
1747 __node_type* __node = __node_gen(std::forward<_Arg>(__v));
1749 return _M_insert_multi_node(__hint._M_cur, __code, __node);
1752 template<typename _Key, typename _Value,
1753 typename _Alloc, typename _ExtractKey, typename _Equal,
1754 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1756 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1757 _H1, _H2, _Hash, _RehashPolicy,
1759 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1760 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1761 erase(const_iterator __it)
1763 __node_type* __n = __it._M_cur;
1764 std::size_t __bkt = _M_bucket_index(__n);
1766 // Look for previous node to unlink it from the erased one, this
1767 // is why we need buckets to contain the before begin to make
1768 // this search fast.
1769 __node_base* __prev_n = _M_get_previous_node(__bkt, __n);
1770 return _M_erase(__bkt, __prev_n, __n);
1773 template<typename _Key, typename _Value,
1774 typename _Alloc, typename _ExtractKey, typename _Equal,
1775 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1777 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1778 _H1, _H2, _Hash, _RehashPolicy,
1780 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1781 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1782 _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n)
1784 if (__prev_n == _M_buckets[__bkt])
1785 _M_remove_bucket_begin(__bkt, __n->_M_next(),
1786 __n->_M_nxt ? _M_bucket_index(__n->_M_next()) : 0);
1787 else if (__n->_M_nxt)
1789 size_type __next_bkt = _M_bucket_index(__n->_M_next());
1790 if (__next_bkt != __bkt)
1791 _M_buckets[__next_bkt] = __prev_n;
1794 __prev_n->_M_nxt = __n->_M_nxt;
1795 iterator __result(__n->_M_next());
1796 this->_M_deallocate_node(__n);
1802 template<typename _Key, typename _Value,
1803 typename _Alloc, typename _ExtractKey, typename _Equal,
1804 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1806 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1807 _H1, _H2, _Hash, _RehashPolicy,
1809 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1810 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1811 _M_erase(std::true_type, const key_type& __k)
1813 __hash_code __code = this->_M_hash_code(__k);
1814 std::size_t __bkt = _M_bucket_index(__k, __code);
1816 // Look for the node before the first matching node.
1817 __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code);
1821 // We found a matching node, erase it.
1822 __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt);
1823 _M_erase(__bkt, __prev_n, __n);
1827 template<typename _Key, typename _Value,
1828 typename _Alloc, typename _ExtractKey, typename _Equal,
1829 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1831 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1832 _H1, _H2, _Hash, _RehashPolicy,
1834 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1835 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1836 _M_erase(std::false_type, const key_type& __k)
1838 __hash_code __code = this->_M_hash_code(__k);
1839 std::size_t __bkt = _M_bucket_index(__k, __code);
1841 // Look for the node before the first matching node.
1842 __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code);
1846 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1847 // 526. Is it undefined if a function in the standard changes
1849 // We use one loop to find all matching nodes and another to deallocate
1850 // them so that the key stays valid during the first loop. It might be
1851 // invalidated indirectly when destroying nodes.
1852 __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt);
1853 __node_type* __n_last = __n;
1854 std::size_t __n_last_bkt = __bkt;
1857 __n_last = __n_last->_M_next();
1860 __n_last_bkt = _M_bucket_index(__n_last);
1862 while (__n_last_bkt == __bkt && this->_M_equals(__k, __code, __n_last));
1864 // Deallocate nodes.
1865 size_type __result = 0;
1868 __node_type* __p = __n->_M_next();
1869 this->_M_deallocate_node(__n);
1874 while (__n != __n_last);
1876 if (__prev_n == _M_buckets[__bkt])
1877 _M_remove_bucket_begin(__bkt, __n_last, __n_last_bkt);
1878 else if (__n_last && __n_last_bkt != __bkt)
1879 _M_buckets[__n_last_bkt] = __prev_n;
1880 __prev_n->_M_nxt = __n_last;
1884 template<typename _Key, typename _Value,
1885 typename _Alloc, typename _ExtractKey, typename _Equal,
1886 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1888 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1889 _H1, _H2, _Hash, _RehashPolicy,
1891 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1892 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1893 erase(const_iterator __first, const_iterator __last)
1895 __node_type* __n = __first._M_cur;
1896 __node_type* __last_n = __last._M_cur;
1897 if (__n == __last_n)
1898 return iterator(__n);
1900 std::size_t __bkt = _M_bucket_index(__n);
1902 __node_base* __prev_n = _M_get_previous_node(__bkt, __n);
1903 bool __is_bucket_begin = __n == _M_bucket_begin(__bkt);
1904 std::size_t __n_bkt = __bkt;
1909 __node_type* __tmp = __n;
1910 __n = __n->_M_next();
1911 this->_M_deallocate_node(__tmp);
1915 __n_bkt = _M_bucket_index(__n);
1917 while (__n != __last_n && __n_bkt == __bkt);
1918 if (__is_bucket_begin)
1919 _M_remove_bucket_begin(__bkt, __n, __n_bkt);
1920 if (__n == __last_n)
1922 __is_bucket_begin = true;
1926 if (__n && (__n_bkt != __bkt || __is_bucket_begin))
1927 _M_buckets[__n_bkt] = __prev_n;
1928 __prev_n->_M_nxt = __n;
1929 return iterator(__n);
1932 template<typename _Key, typename _Value,
1933 typename _Alloc, typename _ExtractKey, typename _Equal,
1934 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1937 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1938 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1941 this->_M_deallocate_nodes(_M_begin());
1942 __builtin_memset(_M_buckets, 0, _M_bucket_count * sizeof(__bucket_type));
1943 _M_element_count = 0;
1944 _M_before_begin._M_nxt = nullptr;
1947 template<typename _Key, typename _Value,
1948 typename _Alloc, typename _ExtractKey, typename _Equal,
1949 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1952 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1953 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1954 rehash(size_type __n)
1956 const __rehash_state& __saved_state = _M_rehash_policy._M_state();
1957 std::size_t __buckets
1958 = std::max(_M_rehash_policy._M_bkt_for_elements(_M_element_count + 1),
1960 __buckets = _M_rehash_policy._M_next_bkt(__buckets);
1962 if (__buckets != _M_bucket_count)
1963 _M_rehash(__buckets, __saved_state);
1965 // No rehash, restore previous state to keep a consistent state.
1966 _M_rehash_policy._M_reset(__saved_state);
1969 template<typename _Key, typename _Value,
1970 typename _Alloc, typename _ExtractKey, typename _Equal,
1971 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1974 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1975 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1976 _M_rehash(size_type __n, const __rehash_state& __state)
1980 _M_rehash_aux(__n, __unique_keys());
1984 // A failure here means that buckets allocation failed. We only
1985 // have to restore hash policy previous state.
1986 _M_rehash_policy._M_reset(__state);
1987 __throw_exception_again;
1991 // Rehash when there is no equivalent elements.
1992 template<typename _Key, typename _Value,
1993 typename _Alloc, typename _ExtractKey, typename _Equal,
1994 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1997 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1998 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1999 _M_rehash_aux(size_type __n, std::true_type)
2001 __bucket_type* __new_buckets = _M_allocate_buckets(__n);
2002 __node_type* __p = _M_begin();
2003 _M_before_begin._M_nxt = nullptr;
2004 std::size_t __bbegin_bkt = 0;
2007 __node_type* __next = __p->_M_next();
2008 std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n);
2009 if (!__new_buckets[__bkt])
2011 __p->_M_nxt = _M_before_begin._M_nxt;
2012 _M_before_begin._M_nxt = __p;
2013 __new_buckets[__bkt] = &_M_before_begin;
2015 __new_buckets[__bbegin_bkt] = __p;
2016 __bbegin_bkt = __bkt;
2020 __p->_M_nxt = __new_buckets[__bkt]->_M_nxt;
2021 __new_buckets[__bkt]->_M_nxt = __p;
2026 _M_deallocate_buckets();
2027 _M_bucket_count = __n;
2028 _M_buckets = __new_buckets;
2031 // Rehash when there can be equivalent elements, preserve their relative
2033 template<typename _Key, typename _Value,
2034 typename _Alloc, typename _ExtractKey, typename _Equal,
2035 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
2038 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
2039 _H1, _H2, _Hash, _RehashPolicy, _Traits>::
2040 _M_rehash_aux(size_type __n, std::false_type)
2042 __bucket_type* __new_buckets = _M_allocate_buckets(__n);
2044 __node_type* __p = _M_begin();
2045 _M_before_begin._M_nxt = nullptr;
2046 std::size_t __bbegin_bkt = 0;
2047 std::size_t __prev_bkt = 0;
2048 __node_type* __prev_p = nullptr;
2049 bool __check_bucket = false;
2053 __node_type* __next = __p->_M_next();
2054 std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n);
2056 if (__prev_p && __prev_bkt == __bkt)
2058 // Previous insert was already in this bucket, we insert after
2059 // the previously inserted one to preserve equivalent elements
2061 __p->_M_nxt = __prev_p->_M_nxt;
2062 __prev_p->_M_nxt = __p;
2064 // Inserting after a node in a bucket require to check that we
2065 // haven't change the bucket last node, in this case next
2066 // bucket containing its before begin node must be updated. We
2067 // schedule a check as soon as we move out of the sequence of
2068 // equivalent nodes to limit the number of checks.
2069 __check_bucket = true;
2075 // Check if we shall update the next bucket because of
2076 // insertions into __prev_bkt bucket.
2077 if (__prev_p->_M_nxt)
2079 std::size_t __next_bkt
2080 = __hash_code_base::_M_bucket_index(__prev_p->_M_next(),
2082 if (__next_bkt != __prev_bkt)
2083 __new_buckets[__next_bkt] = __prev_p;
2085 __check_bucket = false;
2088 if (!__new_buckets[__bkt])
2090 __p->_M_nxt = _M_before_begin._M_nxt;
2091 _M_before_begin._M_nxt = __p;
2092 __new_buckets[__bkt] = &_M_before_begin;
2094 __new_buckets[__bbegin_bkt] = __p;
2095 __bbegin_bkt = __bkt;
2099 __p->_M_nxt = __new_buckets[__bkt]->_M_nxt;
2100 __new_buckets[__bkt]->_M_nxt = __p;
2108 if (__check_bucket && __prev_p->_M_nxt)
2110 std::size_t __next_bkt
2111 = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), __n);
2112 if (__next_bkt != __prev_bkt)
2113 __new_buckets[__next_bkt] = __prev_p;
2116 _M_deallocate_buckets();
2117 _M_bucket_count = __n;
2118 _M_buckets = __new_buckets;
2121 _GLIBCXX_END_NAMESPACE_VERSION
2124 #endif // _HASHTABLE_H