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1 : // hashtable.h header -*- C++ -*-
2 :
3 : // Copyright (C) 2007-2019 Free Software Foundation, Inc.
4 : //
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)
9 : // any later version.
10 :
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.
15 :
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.
19 :
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/>.
24 :
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}
28 : */
29 :
30 : #ifndef _HASHTABLE_H
31 : #define _HASHTABLE_H 1
32 :
33 : #pragma GCC system_header
34 :
35 : #include <bits/hashtable_policy.h>
36 : #if __cplusplus > 201402L
37 : # include <bits/node_handle.h>
38 : #endif
39 :
40 : namespace std _GLIBCXX_VISIBILITY(default)
41 : {
42 : _GLIBCXX_BEGIN_NAMESPACE_VERSION
43 :
44 : template<typename _Tp, typename _Hash>
45 : using __cache_default
46 : = __not_<__and_<// Do not cache for fast hasher.
47 : __is_fast_hash<_Hash>,
48 : // Mandatory to have erase not throwing.
49 : __is_nothrow_invocable<const _Hash&, const _Tp&>>>;
50 :
51 : /**
52 : * Primary class template _Hashtable.
53 : *
54 : * @ingroup hashtable-detail
55 : *
56 : * @tparam _Value CopyConstructible type.
57 : *
58 : * @tparam _Key CopyConstructible type.
59 : *
60 : * @tparam _Alloc An allocator type
61 : * ([lib.allocator.requirements]) whose _Alloc::value_type is
62 : * _Value. As a conforming extension, we allow for
63 : * _Alloc::value_type != _Value.
64 : *
65 : * @tparam _ExtractKey Function object that takes an object of type
66 : * _Value and returns a value of type _Key.
67 : *
68 : * @tparam _Equal Function object that takes two objects of type k
69 : * and returns a bool-like value that is true if the two objects
70 : * are considered equal.
71 : *
72 : * @tparam _H1 The hash function. A unary function object with
73 : * argument type _Key and result type size_t. Return values should
74 : * be distributed over the entire range [0, numeric_limits<size_t>:::max()].
75 : *
76 : * @tparam _H2 The range-hashing function (in the terminology of
77 : * Tavori and Dreizin). A binary function object whose argument
78 : * types and result type are all size_t. Given arguments r and N,
79 : * the return value is in the range [0, N).
80 : *
81 : * @tparam _Hash The ranged hash function (Tavori and Dreizin). A
82 : * binary function whose argument types are _Key and size_t and
83 : * whose result type is size_t. Given arguments k and N, the
84 : * return value is in the range [0, N). Default: hash(k, N) =
85 : * h2(h1(k), N). If _Hash is anything other than the default, _H1
86 : * and _H2 are ignored.
87 : *
88 : * @tparam _RehashPolicy Policy class with three members, all of
89 : * which govern the bucket count. _M_next_bkt(n) returns a bucket
90 : * count no smaller than n. _M_bkt_for_elements(n) returns a
91 : * bucket count appropriate for an element count of n.
92 : * _M_need_rehash(n_bkt, n_elt, n_ins) determines whether, if the
93 : * current bucket count is n_bkt and the current element count is
94 : * n_elt, we need to increase the bucket count. If so, returns
95 : * make_pair(true, n), where n is the new bucket count. If not,
96 : * returns make_pair(false, <anything>)
97 : *
98 : * @tparam _Traits Compile-time class with three boolean
99 : * std::integral_constant members: __cache_hash_code, __constant_iterators,
100 : * __unique_keys.
101 : *
102 : * Each _Hashtable data structure has:
103 : *
104 : * - _Bucket[] _M_buckets
105 : * - _Hash_node_base _M_before_begin
106 : * - size_type _M_bucket_count
107 : * - size_type _M_element_count
108 : *
109 : * with _Bucket being _Hash_node* and _Hash_node containing:
110 : *
111 : * - _Hash_node* _M_next
112 : * - Tp _M_value
113 : * - size_t _M_hash_code if cache_hash_code is true
114 : *
115 : * In terms of Standard containers the hashtable is like the aggregation of:
116 : *
117 : * - std::forward_list<_Node> containing the elements
118 : * - std::vector<std::forward_list<_Node>::iterator> representing the buckets
119 : *
120 : * The non-empty buckets contain the node before the first node in the
121 : * bucket. This design makes it possible to implement something like a
122 : * std::forward_list::insert_after on container insertion and
123 : * std::forward_list::erase_after on container erase
124 : * calls. _M_before_begin is equivalent to
125 : * std::forward_list::before_begin. Empty buckets contain
126 : * nullptr. Note that one of the non-empty buckets contains
127 : * &_M_before_begin which is not a dereferenceable node so the
128 : * node pointer in a bucket shall never be dereferenced, only its
129 : * next node can be.
130 : *
131 : * Walking through a bucket's nodes requires a check on the hash code to
132 : * see if each node is still in the bucket. Such a design assumes a
133 : * quite efficient hash functor and is one of the reasons it is
134 : * highly advisable to set __cache_hash_code to true.
135 : *
136 : * The container iterators are simply built from nodes. This way
137 : * incrementing the iterator is perfectly efficient independent of
138 : * how many empty buckets there are in the container.
139 : *
140 : * On insert we compute the element's hash code and use it to find the
141 : * bucket index. If the element must be inserted in an empty bucket
142 : * we add it at the beginning of the singly linked list and make the
143 : * bucket point to _M_before_begin. The bucket that used to point to
144 : * _M_before_begin, if any, is updated to point to its new before
145 : * begin node.
146 : *
147 : * On erase, the simple iterator design requires using the hash
148 : * functor to get the index of the bucket to update. For this
149 : * reason, when __cache_hash_code is set to false the hash functor must
150 : * not throw and this is enforced by a static assertion.
151 : *
152 : * Functionality is implemented by decomposition into base classes,
153 : * where the derived _Hashtable class is used in _Map_base,
154 : * _Insert, _Rehash_base, and _Equality base classes to access the
155 : * "this" pointer. _Hashtable_base is used in the base classes as a
156 : * non-recursive, fully-completed-type so that detailed nested type
157 : * information, such as iterator type and node type, can be
158 : * used. This is similar to the "Curiously Recurring Template
159 : * Pattern" (CRTP) technique, but uses a reconstructed, not
160 : * explicitly passed, template pattern.
161 : *
162 : * Base class templates are:
163 : * - __detail::_Hashtable_base
164 : * - __detail::_Map_base
165 : * - __detail::_Insert
166 : * - __detail::_Rehash_base
167 : * - __detail::_Equality
168 : */
169 : template<typename _Key, typename _Value, typename _Alloc,
170 : typename _ExtractKey, typename _Equal,
171 : typename _H1, typename _H2, typename _Hash,
172 : typename _RehashPolicy, typename _Traits>
173 : class _Hashtable
174 : : public __detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal,
175 : _H1, _H2, _Hash, _Traits>,
176 : public __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
177 : _H1, _H2, _Hash, _RehashPolicy, _Traits>,
178 : public __detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal,
179 : _H1, _H2, _Hash, _RehashPolicy, _Traits>,
180 : public __detail::_Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
181 : _H1, _H2, _Hash, _RehashPolicy, _Traits>,
182 : public __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
183 : _H1, _H2, _Hash, _RehashPolicy, _Traits>,
184 : private __detail::_Hashtable_alloc<
185 : __alloc_rebind<_Alloc,
186 : __detail::_Hash_node<_Value,
187 : _Traits::__hash_cached::value>>>
188 : {
189 : static_assert(is_same<typename remove_cv<_Value>::type, _Value>::value,
190 : "unordered container must have a non-const, non-volatile value_type");
191 : #ifdef __STRICT_ANSI__
192 : static_assert(is_same<typename _Alloc::value_type, _Value>{},
193 : "unordered container must have the same value_type as its allocator");
194 : #endif
195 :
196 : using __traits_type = _Traits;
197 : using __hash_cached = typename __traits_type::__hash_cached;
198 : using __node_type = __detail::_Hash_node<_Value, __hash_cached::value>;
199 : using __node_alloc_type = __alloc_rebind<_Alloc, __node_type>;
200 :
201 : using __hashtable_alloc = __detail::_Hashtable_alloc<__node_alloc_type>;
202 :
203 : using __value_alloc_traits =
204 : typename __hashtable_alloc::__value_alloc_traits;
205 : using __node_alloc_traits =
206 : typename __hashtable_alloc::__node_alloc_traits;
207 : using __node_base = typename __hashtable_alloc::__node_base;
208 : using __bucket_type = typename __hashtable_alloc::__bucket_type;
209 :
210 : public:
211 : typedef _Key key_type;
212 : typedef _Value value_type;
213 : typedef _Alloc allocator_type;
214 : typedef _Equal key_equal;
215 :
216 : // mapped_type, if present, comes from _Map_base.
217 : // hasher, if present, comes from _Hash_code_base/_Hashtable_base.
218 : typedef typename __value_alloc_traits::pointer pointer;
219 : typedef typename __value_alloc_traits::const_pointer const_pointer;
220 : typedef value_type& reference;
221 : typedef const value_type& const_reference;
222 :
223 : private:
224 : using __rehash_type = _RehashPolicy;
225 : using __rehash_state = typename __rehash_type::_State;
226 :
227 : using __constant_iterators = typename __traits_type::__constant_iterators;
228 : using __unique_keys = typename __traits_type::__unique_keys;
229 :
230 : using __key_extract = typename std::conditional<
231 : __constant_iterators::value,
232 : __detail::_Identity,
233 : __detail::_Select1st>::type;
234 :
235 : using __hashtable_base = __detail::
236 : _Hashtable_base<_Key, _Value, _ExtractKey,
237 : _Equal, _H1, _H2, _Hash, _Traits>;
238 :
239 : using __hash_code_base = typename __hashtable_base::__hash_code_base;
240 : using __hash_code = typename __hashtable_base::__hash_code;
241 : using __ireturn_type = typename __hashtable_base::__ireturn_type;
242 :
243 : using __map_base = __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey,
244 : _Equal, _H1, _H2, _Hash,
245 : _RehashPolicy, _Traits>;
246 :
247 : using __rehash_base = __detail::_Rehash_base<_Key, _Value, _Alloc,
248 : _ExtractKey, _Equal,
249 : _H1, _H2, _Hash,
250 : _RehashPolicy, _Traits>;
251 :
252 : using __eq_base = __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey,
253 : _Equal, _H1, _H2, _Hash,
254 : _RehashPolicy, _Traits>;
255 :
256 : using __reuse_or_alloc_node_type =
257 : __detail::_ReuseOrAllocNode<__node_alloc_type>;
258 :
259 : // Metaprogramming for picking apart hash caching.
260 : template<typename _Cond>
261 : using __if_hash_cached = __or_<__not_<__hash_cached>, _Cond>;
262 :
263 : template<typename _Cond>
264 : using __if_hash_not_cached = __or_<__hash_cached, _Cond>;
265 :
266 : // Compile-time diagnostics.
267 :
268 : // _Hash_code_base has everything protected, so use this derived type to
269 : // access it.
270 : struct __hash_code_base_access : __hash_code_base
271 : { using __hash_code_base::_M_bucket_index; };
272 :
273 : // Getting a bucket index from a node shall not throw because it is used
274 : // in methods (erase, swap...) that shall not throw.
275 : static_assert(noexcept(declval<const __hash_code_base_access&>()
276 : ._M_bucket_index((const __node_type*)nullptr,
277 : (std::size_t)0)),
278 : "Cache the hash code or qualify your functors involved"
279 : " in hash code and bucket index computation with noexcept");
280 :
281 : // Following two static assertions are necessary to guarantee
282 : // that local_iterator will be default constructible.
283 :
284 : // When hash codes are cached local iterator inherits from H2 functor
285 : // which must then be default constructible.
286 : static_assert(__if_hash_cached<is_default_constructible<_H2>>::value,
287 : "Functor used to map hash code to bucket index"
288 : " must be default constructible");
289 :
290 : template<typename _Keya, typename _Valuea, typename _Alloca,
291 : typename _ExtractKeya, typename _Equala,
292 : typename _H1a, typename _H2a, typename _Hasha,
293 : typename _RehashPolicya, typename _Traitsa,
294 : bool _Unique_keysa>
295 : friend struct __detail::_Map_base;
296 :
297 : template<typename _Keya, typename _Valuea, typename _Alloca,
298 : typename _ExtractKeya, typename _Equala,
299 : typename _H1a, typename _H2a, typename _Hasha,
300 : typename _RehashPolicya, typename _Traitsa>
301 : friend struct __detail::_Insert_base;
302 :
303 : template<typename _Keya, typename _Valuea, typename _Alloca,
304 : typename _ExtractKeya, typename _Equala,
305 : typename _H1a, typename _H2a, typename _Hasha,
306 : typename _RehashPolicya, typename _Traitsa,
307 : bool _Constant_iteratorsa>
308 : friend struct __detail::_Insert;
309 :
310 : public:
311 : using size_type = typename __hashtable_base::size_type;
312 : using difference_type = typename __hashtable_base::difference_type;
313 :
314 : using iterator = typename __hashtable_base::iterator;
315 : using const_iterator = typename __hashtable_base::const_iterator;
316 :
317 : using local_iterator = typename __hashtable_base::local_iterator;
318 : using const_local_iterator = typename __hashtable_base::
319 : const_local_iterator;
320 :
321 : #if __cplusplus > 201402L
322 : using node_type = _Node_handle<_Key, _Value, __node_alloc_type>;
323 : using insert_return_type = _Node_insert_return<iterator, node_type>;
324 : #endif
325 :
326 : private:
327 : __bucket_type* _M_buckets = &_M_single_bucket;
328 : size_type _M_bucket_count = 1;
329 : __node_base _M_before_begin;
330 : size_type _M_element_count = 0;
331 : _RehashPolicy _M_rehash_policy;
332 :
333 : // A single bucket used when only need for 1 bucket. Especially
334 : // interesting in move semantic to leave hashtable with only 1 buckets
335 : // which is not allocated so that we can have those operations noexcept
336 : // qualified.
337 : // Note that we can't leave hashtable with 0 bucket without adding
338 : // numerous checks in the code to avoid 0 modulus.
339 : __bucket_type _M_single_bucket = nullptr;
340 :
341 : bool
342 712 : _M_uses_single_bucket(__bucket_type* __bkts) const
343 712 : { return __builtin_expect(__bkts == &_M_single_bucket, false); }
344 :
345 : bool
346 : _M_uses_single_bucket() const
347 : { return _M_uses_single_bucket(_M_buckets); }
348 :
349 : __hashtable_alloc&
350 : _M_base_alloc() { return *this; }
351 :
352 : __bucket_type*
353 : _M_allocate_buckets(size_type __n)
354 : {
355 : if (__builtin_expect(__n == 1, false))
356 : {
357 : _M_single_bucket = nullptr;
358 : return &_M_single_bucket;
359 : }
360 :
361 : return __hashtable_alloc::_M_allocate_buckets(__n);
362 : }
363 :
364 : void
365 712 : _M_deallocate_buckets(__bucket_type* __bkts, size_type __n)
366 : {
367 712 : if (_M_uses_single_bucket(__bkts))
368 : return;
369 :
370 0 : __hashtable_alloc::_M_deallocate_buckets(__bkts, __n);
371 : }
372 :
373 : void
374 712 : _M_deallocate_buckets()
375 1424 : { _M_deallocate_buckets(_M_buckets, _M_bucket_count); }
376 :
377 : // Gets bucket begin, deals with the fact that non-empty buckets contain
378 : // their before begin node.
379 : __node_type*
380 : _M_bucket_begin(size_type __bkt) const;
381 :
382 : __node_type*
383 712 : _M_begin() const
384 : { return static_cast<__node_type*>(_M_before_begin._M_nxt); }
385 :
386 : // Assign *this using another _Hashtable instance. Either elements
387 : // are copy or move depends on the _NodeGenerator.
388 : template<typename _Ht, typename _NodeGenerator>
389 : void
390 : _M_assign_elements(_Ht&&, const _NodeGenerator&);
391 :
392 : template<typename _NodeGenerator>
393 : void
394 : _M_assign(const _Hashtable&, const _NodeGenerator&);
395 :
396 : void
397 : _M_move_assign(_Hashtable&&, std::true_type);
398 :
399 : void
400 : _M_move_assign(_Hashtable&&, std::false_type);
401 :
402 : void
403 : _M_reset() noexcept;
404 :
405 : _Hashtable(const _H1& __h1, const _H2& __h2, const _Hash& __h,
406 : const _Equal& __eq, const _ExtractKey& __exk,
407 : const allocator_type& __a)
408 : : __hashtable_base(__exk, __h1, __h2, __h, __eq),
409 : __hashtable_alloc(__node_alloc_type(__a))
410 : { }
411 :
412 : template<bool _No_realloc = true>
413 : static constexpr bool
414 : _S_nothrow_move()
415 : {
416 : #if __cplusplus <= 201402L
417 : return __and_<__bool_constant<_No_realloc>,
418 : is_nothrow_copy_constructible<_H1>,
419 : is_nothrow_copy_constructible<_Equal>>::value;
420 : #else
421 : if constexpr (_No_realloc)
422 : if constexpr (is_nothrow_copy_constructible<_H1>())
423 : return is_nothrow_copy_constructible<_Equal>();
424 : return false;
425 : #endif
426 : }
427 :
428 : _Hashtable(_Hashtable&& __ht, __node_alloc_type&& __a,
429 : true_type /* alloc always equal */)
430 : noexcept(_S_nothrow_move());
431 :
432 : _Hashtable(_Hashtable&&, __node_alloc_type&&,
433 : false_type /* alloc always equal */);
434 :
435 :
436 : public:
437 : // Constructor, destructor, assignment, swap
438 : _Hashtable() = default;
439 : _Hashtable(size_type __bucket_hint,
440 : const _H1&, const _H2&, const _Hash&,
441 : const _Equal&, const _ExtractKey&,
442 : const allocator_type&);
443 :
444 : template<typename _InputIterator>
445 : _Hashtable(_InputIterator __first, _InputIterator __last,
446 : size_type __bucket_hint,
447 : const _H1&, const _H2&, const _Hash&,
448 : const _Equal&, const _ExtractKey&,
449 : const allocator_type&);
450 :
451 : _Hashtable(const _Hashtable&);
452 :
453 : _Hashtable(_Hashtable&& __ht)
454 : noexcept(_S_nothrow_move())
455 : : _Hashtable(std::move(__ht), std::move(__ht._M_node_allocator()),
456 : true_type{})
457 : { }
458 :
459 : _Hashtable(const _Hashtable&, const allocator_type&);
460 :
461 : _Hashtable(_Hashtable&& __ht, const allocator_type& __a)
462 : noexcept(_S_nothrow_move<__node_alloc_traits::_S_always_equal()>())
463 : : _Hashtable(std::move(__ht), __node_alloc_type(__a),
464 : typename __node_alloc_traits::is_always_equal{})
465 : { }
466 :
467 : // Use delegating constructors.
468 : explicit
469 : _Hashtable(const allocator_type& __a)
470 : : __hashtable_alloc(__node_alloc_type(__a))
471 : { }
472 :
473 : explicit
474 : _Hashtable(size_type __n,
475 : const _H1& __hf = _H1(),
476 : const key_equal& __eql = key_equal(),
477 : const allocator_type& __a = allocator_type())
478 : : _Hashtable(__n, __hf, _H2(), _Hash(), __eql,
479 : __key_extract(), __a)
480 : { }
481 :
482 : template<typename _InputIterator>
483 : _Hashtable(_InputIterator __f, _InputIterator __l,
484 : size_type __n = 0,
485 : const _H1& __hf = _H1(),
486 : const key_equal& __eql = key_equal(),
487 : const allocator_type& __a = allocator_type())
488 : : _Hashtable(__f, __l, __n, __hf, _H2(), _Hash(), __eql,
489 : __key_extract(), __a)
490 : { }
491 :
492 : _Hashtable(initializer_list<value_type> __l,
493 : size_type __n = 0,
494 : const _H1& __hf = _H1(),
495 : const key_equal& __eql = key_equal(),
496 : const allocator_type& __a = allocator_type())
497 : : _Hashtable(__l.begin(), __l.end(), __n, __hf, _H2(), _Hash(), __eql,
498 : __key_extract(), __a)
499 : { }
500 :
501 : _Hashtable&
502 : operator=(const _Hashtable& __ht);
503 :
504 : _Hashtable&
505 : operator=(_Hashtable&& __ht)
506 : noexcept(__node_alloc_traits::_S_nothrow_move()
507 : && is_nothrow_move_assignable<_H1>::value
508 : && is_nothrow_move_assignable<_Equal>::value)
509 : {
510 : constexpr bool __move_storage =
511 : __node_alloc_traits::_S_propagate_on_move_assign()
512 : || __node_alloc_traits::_S_always_equal();
513 : _M_move_assign(std::move(__ht), __bool_constant<__move_storage>());
514 : return *this;
515 : }
516 :
517 : _Hashtable&
518 : operator=(initializer_list<value_type> __l)
519 : {
520 : __reuse_or_alloc_node_type __roan(_M_begin(), *this);
521 : _M_before_begin._M_nxt = nullptr;
522 : clear();
523 : this->_M_insert_range(__l.begin(), __l.end(), __roan, __unique_keys());
524 : return *this;
525 : }
526 :
527 : ~_Hashtable() noexcept;
528 :
529 : void
530 : swap(_Hashtable&)
531 : noexcept(__and_<__is_nothrow_swappable<_H1>,
532 : __is_nothrow_swappable<_Equal>>::value);
533 :
534 : // Basic container operations
535 : iterator
536 : begin() noexcept
537 : { return iterator(_M_begin()); }
538 :
539 : const_iterator
540 : begin() const noexcept
541 : { return const_iterator(_M_begin()); }
542 :
543 : iterator
544 : end() noexcept
545 : { return iterator(nullptr); }
546 :
547 : const_iterator
548 : end() const noexcept
549 : { return const_iterator(nullptr); }
550 :
551 : const_iterator
552 : cbegin() const noexcept
553 : { return const_iterator(_M_begin()); }
554 :
555 : const_iterator
556 : cend() const noexcept
557 : { return const_iterator(nullptr); }
558 :
559 : size_type
560 : size() const noexcept
561 : { return _M_element_count; }
562 :
563 : _GLIBCXX_NODISCARD bool
564 : empty() const noexcept
565 : { return size() == 0; }
566 :
567 : allocator_type
568 : get_allocator() const noexcept
569 : { return allocator_type(this->_M_node_allocator()); }
570 :
571 : size_type
572 : max_size() const noexcept
573 : { return __node_alloc_traits::max_size(this->_M_node_allocator()); }
574 :
575 : // Observers
576 : key_equal
577 : key_eq() const
578 : { return this->_M_eq(); }
579 :
580 : // hash_function, if present, comes from _Hash_code_base.
581 :
582 : // Bucket operations
583 : size_type
584 : bucket_count() const noexcept
585 : { return _M_bucket_count; }
586 :
587 : size_type
588 : max_bucket_count() const noexcept
589 : { return max_size(); }
590 :
591 : size_type
592 : bucket_size(size_type __n) const
593 : { return std::distance(begin(__n), end(__n)); }
594 :
595 : size_type
596 : bucket(const key_type& __k) const
597 : { return _M_bucket_index(__k, this->_M_hash_code(__k)); }
598 :
599 : local_iterator
600 : begin(size_type __n)
601 : {
602 : return local_iterator(*this, _M_bucket_begin(__n),
603 : __n, _M_bucket_count);
604 : }
605 :
606 : local_iterator
607 : end(size_type __n)
608 : { return local_iterator(*this, nullptr, __n, _M_bucket_count); }
609 :
610 : const_local_iterator
611 : begin(size_type __n) const
612 : {
613 : return const_local_iterator(*this, _M_bucket_begin(__n),
614 : __n, _M_bucket_count);
615 : }
616 :
617 : const_local_iterator
618 : end(size_type __n) const
619 : { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); }
620 :
621 : // DR 691.
622 : const_local_iterator
623 : cbegin(size_type __n) const
624 : {
625 : return const_local_iterator(*this, _M_bucket_begin(__n),
626 : __n, _M_bucket_count);
627 : }
628 :
629 : const_local_iterator
630 : cend(size_type __n) const
631 : { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); }
632 :
633 : float
634 : load_factor() const noexcept
635 : {
636 : return static_cast<float>(size()) / static_cast<float>(bucket_count());
637 : }
638 :
639 : // max_load_factor, if present, comes from _Rehash_base.
640 :
641 : // Generalization of max_load_factor. Extension, not found in
642 : // TR1. Only useful if _RehashPolicy is something other than
643 : // the default.
644 : const _RehashPolicy&
645 : __rehash_policy() const
646 : { return _M_rehash_policy; }
647 :
648 : void
649 : __rehash_policy(const _RehashPolicy& __pol)
650 : { _M_rehash_policy = __pol; }
651 :
652 : // Lookup.
653 : iterator
654 : find(const key_type& __k);
655 :
656 : const_iterator
657 : find(const key_type& __k) const;
658 :
659 : size_type
660 : count(const key_type& __k) const;
661 :
662 : std::pair<iterator, iterator>
663 : equal_range(const key_type& __k);
664 :
665 : std::pair<const_iterator, const_iterator>
666 : equal_range(const key_type& __k) const;
667 :
668 : protected:
669 : // Bucket index computation helpers.
670 : size_type
671 : _M_bucket_index(__node_type* __n) const noexcept
672 : { return __hash_code_base::_M_bucket_index(__n, _M_bucket_count); }
673 :
674 : size_type
675 : _M_bucket_index(const key_type& __k, __hash_code __c) const
676 : { return __hash_code_base::_M_bucket_index(__k, __c, _M_bucket_count); }
677 :
678 : // Find and insert helper functions and types
679 : // Find the node before the one matching the criteria.
680 : __node_base*
681 : _M_find_before_node(size_type, const key_type&, __hash_code) const;
682 :
683 : __node_type*
684 : _M_find_node(size_type __bkt, const key_type& __key,
685 : __hash_code __c) const
686 : {
687 : __node_base* __before_n = _M_find_before_node(__bkt, __key, __c);
688 : if (__before_n)
689 : return static_cast<__node_type*>(__before_n->_M_nxt);
690 : return nullptr;
691 : }
692 :
693 : // Insert a node at the beginning of a bucket.
694 : void
695 : _M_insert_bucket_begin(size_type, __node_type*);
696 :
697 : // Remove the bucket first node
698 : void
699 : _M_remove_bucket_begin(size_type __bkt, __node_type* __next_n,
700 : size_type __next_bkt);
701 :
702 : // Get the node before __n in the bucket __bkt
703 : __node_base*
704 : _M_get_previous_node(size_type __bkt, __node_base* __n);
705 :
706 : // Insert node with hash code __code, in bucket bkt if no rehash (assumes
707 : // no element with its key already present). Take ownership of the node,
708 : // deallocate it on exception.
709 : iterator
710 : _M_insert_unique_node(size_type __bkt, __hash_code __code,
711 : __node_type* __n, size_type __n_elt = 1);
712 :
713 : // Insert node with hash code __code. Take ownership of the node,
714 : // deallocate it on exception.
715 : iterator
716 : _M_insert_multi_node(__node_type* __hint,
717 : __hash_code __code, __node_type* __n);
718 :
719 : template<typename... _Args>
720 : std::pair<iterator, bool>
721 : _M_emplace(std::true_type, _Args&&... __args);
722 :
723 : template<typename... _Args>
724 : iterator
725 : _M_emplace(std::false_type __uk, _Args&&... __args)
726 : { return _M_emplace(cend(), __uk, std::forward<_Args>(__args)...); }
727 :
728 : // Emplace with hint, useless when keys are unique.
729 : template<typename... _Args>
730 : iterator
731 : _M_emplace(const_iterator, std::true_type __uk, _Args&&... __args)
732 : { return _M_emplace(__uk, std::forward<_Args>(__args)...).first; }
733 :
734 : template<typename... _Args>
735 : iterator
736 : _M_emplace(const_iterator, std::false_type, _Args&&... __args);
737 :
738 : template<typename _Arg, typename _NodeGenerator>
739 : std::pair<iterator, bool>
740 : _M_insert(_Arg&&, const _NodeGenerator&, true_type, size_type = 1);
741 :
742 : template<typename _Arg, typename _NodeGenerator>
743 : iterator
744 : _M_insert(_Arg&& __arg, const _NodeGenerator& __node_gen,
745 : false_type __uk)
746 : {
747 : return _M_insert(cend(), std::forward<_Arg>(__arg), __node_gen,
748 : __uk);
749 : }
750 :
751 : // Insert with hint, not used when keys are unique.
752 : template<typename _Arg, typename _NodeGenerator>
753 : iterator
754 : _M_insert(const_iterator, _Arg&& __arg,
755 : const _NodeGenerator& __node_gen, true_type __uk)
756 : {
757 : return
758 : _M_insert(std::forward<_Arg>(__arg), __node_gen, __uk).first;
759 : }
760 :
761 : // Insert with hint when keys are not unique.
762 : template<typename _Arg, typename _NodeGenerator>
763 : iterator
764 : _M_insert(const_iterator, _Arg&&,
765 : const _NodeGenerator&, false_type);
766 :
767 : size_type
768 : _M_erase(std::true_type, const key_type&);
769 :
770 : size_type
771 : _M_erase(std::false_type, const key_type&);
772 :
773 : iterator
774 : _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n);
775 :
776 : public:
777 : // Emplace
778 : template<typename... _Args>
779 : __ireturn_type
780 : emplace(_Args&&... __args)
781 : { return _M_emplace(__unique_keys(), std::forward<_Args>(__args)...); }
782 :
783 : template<typename... _Args>
784 : iterator
785 : emplace_hint(const_iterator __hint, _Args&&... __args)
786 : {
787 : return _M_emplace(__hint, __unique_keys(),
788 : std::forward<_Args>(__args)...);
789 : }
790 :
791 : // Insert member functions via inheritance.
792 :
793 : // Erase
794 : iterator
795 : erase(const_iterator);
796 :
797 : // LWG 2059.
798 : iterator
799 : erase(iterator __it)
800 : { return erase(const_iterator(__it)); }
801 :
802 : size_type
803 : erase(const key_type& __k)
804 : { return _M_erase(__unique_keys(), __k); }
805 :
806 : iterator
807 : erase(const_iterator, const_iterator);
808 :
809 : void
810 : clear() noexcept;
811 :
812 : // Set number of buckets to be appropriate for container of n element.
813 : void rehash(size_type __n);
814 :
815 : // DR 1189.
816 : // reserve, if present, comes from _Rehash_base.
817 :
818 : #if __cplusplus > 201402L
819 : /// Re-insert an extracted node into a container with unique keys.
820 : insert_return_type
821 : _M_reinsert_node(node_type&& __nh)
822 : {
823 : insert_return_type __ret;
824 : if (__nh.empty())
825 : __ret.position = end();
826 : else
827 : {
828 : __glibcxx_assert(get_allocator() == __nh.get_allocator());
829 :
830 : const key_type& __k = __nh._M_key();
831 : __hash_code __code = this->_M_hash_code(__k);
832 : size_type __bkt = _M_bucket_index(__k, __code);
833 : if (__node_type* __n = _M_find_node(__bkt, __k, __code))
834 : {
835 : __ret.node = std::move(__nh);
836 : __ret.position = iterator(__n);
837 : __ret.inserted = false;
838 : }
839 : else
840 : {
841 : __ret.position
842 : = _M_insert_unique_node(__bkt, __code, __nh._M_ptr);
843 : __nh._M_ptr = nullptr;
844 : __ret.inserted = true;
845 : }
846 : }
847 : return __ret;
848 : }
849 :
850 : /// Re-insert an extracted node into a container with equivalent keys.
851 : iterator
852 : _M_reinsert_node_multi(const_iterator __hint, node_type&& __nh)
853 : {
854 : iterator __ret;
855 : if (__nh.empty())
856 : __ret = end();
857 : else
858 : {
859 : __glibcxx_assert(get_allocator() == __nh.get_allocator());
860 :
861 : auto __code = this->_M_hash_code(__nh._M_key());
862 : auto __node = std::exchange(__nh._M_ptr, nullptr);
863 : // FIXME: this deallocates the node on exception.
864 : __ret = _M_insert_multi_node(__hint._M_cur, __code, __node);
865 : }
866 : return __ret;
867 : }
868 :
869 : /// Extract a node.
870 : node_type
871 : extract(const_iterator __pos)
872 : {
873 : __node_type* __n = __pos._M_cur;
874 : size_t __bkt = _M_bucket_index(__n);
875 :
876 : // Look for previous node to unlink it from the erased one, this
877 : // is why we need buckets to contain the before begin to make
878 : // this search fast.
879 : __node_base* __prev_n = _M_get_previous_node(__bkt, __n);
880 :
881 : if (__prev_n == _M_buckets[__bkt])
882 : _M_remove_bucket_begin(__bkt, __n->_M_next(),
883 : __n->_M_nxt ? _M_bucket_index(__n->_M_next()) : 0);
884 : else if (__n->_M_nxt)
885 : {
886 : size_type __next_bkt = _M_bucket_index(__n->_M_next());
887 : if (__next_bkt != __bkt)
888 : _M_buckets[__next_bkt] = __prev_n;
889 : }
890 :
891 : __prev_n->_M_nxt = __n->_M_nxt;
892 : __n->_M_nxt = nullptr;
893 : --_M_element_count;
894 : return { __n, this->_M_node_allocator() };
895 : }
896 :
897 : /// Extract a node.
898 : node_type
899 : extract(const _Key& __k)
900 : {
901 : node_type __nh;
902 : auto __pos = find(__k);
903 : if (__pos != end())
904 : __nh = extract(const_iterator(__pos));
905 : return __nh;
906 : }
907 :
908 : /// Merge from a compatible container into one with unique keys.
909 : template<typename _Compatible_Hashtable>
910 : void
911 : _M_merge_unique(_Compatible_Hashtable& __src) noexcept
912 : {
913 : static_assert(is_same_v<typename _Compatible_Hashtable::node_type,
914 : node_type>, "Node types are compatible");
915 : __glibcxx_assert(get_allocator() == __src.get_allocator());
916 :
917 : auto __n_elt = __src.size();
918 : for (auto __i = __src.begin(), __end = __src.end(); __i != __end;)
919 : {
920 : auto __pos = __i++;
921 : const key_type& __k = this->_M_extract()(__pos._M_cur->_M_v());
922 : __hash_code __code = this->_M_hash_code(__k);
923 : size_type __bkt = _M_bucket_index(__k, __code);
924 : if (_M_find_node(__bkt, __k, __code) == nullptr)
925 : {
926 : auto __nh = __src.extract(__pos);
927 : _M_insert_unique_node(__bkt, __code, __nh._M_ptr, __n_elt);
928 : __nh._M_ptr = nullptr;
929 : __n_elt = 1;
930 : }
931 : else if (__n_elt != 1)
932 : --__n_elt;
933 : }
934 : }
935 :
936 : /// Merge from a compatible container into one with equivalent keys.
937 : template<typename _Compatible_Hashtable>
938 : void
939 : _M_merge_multi(_Compatible_Hashtable& __src) noexcept
940 : {
941 : static_assert(is_same_v<typename _Compatible_Hashtable::node_type,
942 : node_type>, "Node types are compatible");
943 : __glibcxx_assert(get_allocator() == __src.get_allocator());
944 :
945 : this->reserve(size() + __src.size());
946 : for (auto __i = __src.begin(), __end = __src.end(); __i != __end;)
947 : _M_reinsert_node_multi(cend(), __src.extract(__i++));
948 : }
949 : #endif // C++17
950 :
951 : private:
952 : // Helper rehash method used when keys are unique.
953 : void _M_rehash_aux(size_type __n, std::true_type);
954 :
955 : // Helper rehash method used when keys can be non-unique.
956 : void _M_rehash_aux(size_type __n, std::false_type);
957 :
958 : // Unconditionally change size of bucket array to n, restore
959 : // hash policy state to __state on exception.
960 : void _M_rehash(size_type __n, const __rehash_state& __state);
961 : };
962 :
963 :
964 : // Definitions of class template _Hashtable's out-of-line member functions.
965 : template<typename _Key, typename _Value,
966 : typename _Alloc, typename _ExtractKey, typename _Equal,
967 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
968 : typename _Traits>
969 : auto
970 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
971 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
972 : _M_bucket_begin(size_type __bkt) const
973 : -> __node_type*
974 : {
975 : __node_base* __n = _M_buckets[__bkt];
976 : return __n ? static_cast<__node_type*>(__n->_M_nxt) : nullptr;
977 : }
978 :
979 : template<typename _Key, typename _Value,
980 : typename _Alloc, typename _ExtractKey, typename _Equal,
981 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
982 : typename _Traits>
983 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
984 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
985 : _Hashtable(size_type __bucket_hint,
986 : const _H1& __h1, const _H2& __h2, const _Hash& __h,
987 : const _Equal& __eq, const _ExtractKey& __exk,
988 : const allocator_type& __a)
989 : : _Hashtable(__h1, __h2, __h, __eq, __exk, __a)
990 : {
991 : auto __bkt = _M_rehash_policy._M_next_bkt(__bucket_hint);
992 : if (__bkt > _M_bucket_count)
993 : {
994 : _M_buckets = _M_allocate_buckets(__bkt);
995 : _M_bucket_count = __bkt;
996 : }
997 : }
998 :
999 : template<typename _Key, typename _Value,
1000 : typename _Alloc, typename _ExtractKey, typename _Equal,
1001 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1002 : typename _Traits>
1003 : template<typename _InputIterator>
1004 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1005 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1006 : _Hashtable(_InputIterator __f, _InputIterator __l,
1007 : size_type __bucket_hint,
1008 : const _H1& __h1, const _H2& __h2, const _Hash& __h,
1009 : const _Equal& __eq, const _ExtractKey& __exk,
1010 : const allocator_type& __a)
1011 : : _Hashtable(__h1, __h2, __h, __eq, __exk, __a)
1012 : {
1013 : auto __nb_elems = __detail::__distance_fw(__f, __l);
1014 : auto __bkt_count =
1015 : _M_rehash_policy._M_next_bkt(
1016 : std::max(_M_rehash_policy._M_bkt_for_elements(__nb_elems),
1017 : __bucket_hint));
1018 :
1019 : if (__bkt_count > _M_bucket_count)
1020 : {
1021 : _M_buckets = _M_allocate_buckets(__bkt_count);
1022 : _M_bucket_count = __bkt_count;
1023 : }
1024 :
1025 : for (; __f != __l; ++__f)
1026 : this->insert(*__f);
1027 : }
1028 :
1029 : template<typename _Key, typename _Value,
1030 : typename _Alloc, typename _ExtractKey, typename _Equal,
1031 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1032 : typename _Traits>
1033 : auto
1034 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1035 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1036 : operator=(const _Hashtable& __ht)
1037 : -> _Hashtable&
1038 : {
1039 : if (&__ht == this)
1040 : return *this;
1041 :
1042 : if (__node_alloc_traits::_S_propagate_on_copy_assign())
1043 : {
1044 : auto& __this_alloc = this->_M_node_allocator();
1045 : auto& __that_alloc = __ht._M_node_allocator();
1046 : if (!__node_alloc_traits::_S_always_equal()
1047 : && __this_alloc != __that_alloc)
1048 : {
1049 : // Replacement allocator cannot free existing storage.
1050 : this->_M_deallocate_nodes(_M_begin());
1051 : _M_before_begin._M_nxt = nullptr;
1052 : _M_deallocate_buckets();
1053 : _M_buckets = nullptr;
1054 : std::__alloc_on_copy(__this_alloc, __that_alloc);
1055 : __hashtable_base::operator=(__ht);
1056 : _M_bucket_count = __ht._M_bucket_count;
1057 : _M_element_count = __ht._M_element_count;
1058 : _M_rehash_policy = __ht._M_rehash_policy;
1059 : __try
1060 : {
1061 : _M_assign(__ht,
1062 : [this](const __node_type* __n)
1063 : { return this->_M_allocate_node(__n->_M_v()); });
1064 : }
1065 : __catch(...)
1066 : {
1067 : // _M_assign took care of deallocating all memory. Now we
1068 : // must make sure this instance remains in a usable state.
1069 : _M_reset();
1070 : __throw_exception_again;
1071 : }
1072 : return *this;
1073 : }
1074 : std::__alloc_on_copy(__this_alloc, __that_alloc);
1075 : }
1076 :
1077 : // Reuse allocated buckets and nodes.
1078 : _M_assign_elements(__ht,
1079 : [](const __reuse_or_alloc_node_type& __roan, const __node_type* __n)
1080 : { return __roan(__n->_M_v()); });
1081 : return *this;
1082 : }
1083 :
1084 : template<typename _Key, typename _Value,
1085 : typename _Alloc, typename _ExtractKey, typename _Equal,
1086 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1087 : typename _Traits>
1088 : template<typename _Ht, typename _NodeGenerator>
1089 : void
1090 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1091 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1092 : _M_assign_elements(_Ht&& __ht, const _NodeGenerator& __node_gen)
1093 : {
1094 : __bucket_type* __former_buckets = nullptr;
1095 : std::size_t __former_bucket_count = _M_bucket_count;
1096 : const __rehash_state& __former_state = _M_rehash_policy._M_state();
1097 :
1098 : if (_M_bucket_count != __ht._M_bucket_count)
1099 : {
1100 : __former_buckets = _M_buckets;
1101 : _M_buckets = _M_allocate_buckets(__ht._M_bucket_count);
1102 : _M_bucket_count = __ht._M_bucket_count;
1103 : }
1104 : else
1105 : __builtin_memset(_M_buckets, 0,
1106 : _M_bucket_count * sizeof(__bucket_type));
1107 :
1108 : __try
1109 : {
1110 : __hashtable_base::operator=(std::forward<_Ht>(__ht));
1111 : _M_element_count = __ht._M_element_count;
1112 : _M_rehash_policy = __ht._M_rehash_policy;
1113 : __reuse_or_alloc_node_type __roan(_M_begin(), *this);
1114 : _M_before_begin._M_nxt = nullptr;
1115 : _M_assign(__ht,
1116 : [&__node_gen, &__roan](__node_type* __n)
1117 : { return __node_gen(__roan, __n); });
1118 : if (__former_buckets)
1119 : _M_deallocate_buckets(__former_buckets, __former_bucket_count);
1120 : }
1121 : __catch(...)
1122 : {
1123 : if (__former_buckets)
1124 : {
1125 : // Restore previous buckets.
1126 : _M_deallocate_buckets();
1127 : _M_rehash_policy._M_reset(__former_state);
1128 : _M_buckets = __former_buckets;
1129 : _M_bucket_count = __former_bucket_count;
1130 : }
1131 : __builtin_memset(_M_buckets, 0,
1132 : _M_bucket_count * sizeof(__bucket_type));
1133 : __throw_exception_again;
1134 : }
1135 : }
1136 :
1137 : template<typename _Key, typename _Value,
1138 : typename _Alloc, typename _ExtractKey, typename _Equal,
1139 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1140 : typename _Traits>
1141 : template<typename _NodeGenerator>
1142 : void
1143 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1144 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1145 : _M_assign(const _Hashtable& __ht, const _NodeGenerator& __node_gen)
1146 : {
1147 : __bucket_type* __buckets = nullptr;
1148 : if (!_M_buckets)
1149 : _M_buckets = __buckets = _M_allocate_buckets(_M_bucket_count);
1150 :
1151 : __try
1152 : {
1153 : if (!__ht._M_before_begin._M_nxt)
1154 : return;
1155 :
1156 : // First deal with the special first node pointed to by
1157 : // _M_before_begin.
1158 : __node_type* __ht_n = __ht._M_begin();
1159 : __node_type* __this_n = __node_gen(__ht_n);
1160 : this->_M_copy_code(__this_n, __ht_n);
1161 : _M_before_begin._M_nxt = __this_n;
1162 : _M_buckets[_M_bucket_index(__this_n)] = &_M_before_begin;
1163 :
1164 : // Then deal with other nodes.
1165 : __node_base* __prev_n = __this_n;
1166 : for (__ht_n = __ht_n->_M_next(); __ht_n; __ht_n = __ht_n->_M_next())
1167 : {
1168 : __this_n = __node_gen(__ht_n);
1169 : __prev_n->_M_nxt = __this_n;
1170 : this->_M_copy_code(__this_n, __ht_n);
1171 : size_type __bkt = _M_bucket_index(__this_n);
1172 : if (!_M_buckets[__bkt])
1173 : _M_buckets[__bkt] = __prev_n;
1174 : __prev_n = __this_n;
1175 : }
1176 : }
1177 : __catch(...)
1178 : {
1179 : clear();
1180 : if (__buckets)
1181 : _M_deallocate_buckets();
1182 : __throw_exception_again;
1183 : }
1184 : }
1185 :
1186 : template<typename _Key, typename _Value,
1187 : typename _Alloc, typename _ExtractKey, typename _Equal,
1188 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1189 : typename _Traits>
1190 : void
1191 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1192 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1193 : _M_reset() noexcept
1194 : {
1195 : _M_rehash_policy._M_reset();
1196 : _M_bucket_count = 1;
1197 : _M_single_bucket = nullptr;
1198 : _M_buckets = &_M_single_bucket;
1199 : _M_before_begin._M_nxt = nullptr;
1200 : _M_element_count = 0;
1201 : }
1202 :
1203 : template<typename _Key, typename _Value,
1204 : typename _Alloc, typename _ExtractKey, typename _Equal,
1205 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1206 : typename _Traits>
1207 : void
1208 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1209 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1210 : _M_move_assign(_Hashtable&& __ht, std::true_type)
1211 : {
1212 : this->_M_deallocate_nodes(_M_begin());
1213 : _M_deallocate_buckets();
1214 : __hashtable_base::operator=(std::move(__ht));
1215 : _M_rehash_policy = __ht._M_rehash_policy;
1216 : if (!__ht._M_uses_single_bucket())
1217 : _M_buckets = __ht._M_buckets;
1218 : else
1219 : {
1220 : _M_buckets = &_M_single_bucket;
1221 : _M_single_bucket = __ht._M_single_bucket;
1222 : }
1223 : _M_bucket_count = __ht._M_bucket_count;
1224 : _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt;
1225 : _M_element_count = __ht._M_element_count;
1226 : std::__alloc_on_move(this->_M_node_allocator(), __ht._M_node_allocator());
1227 :
1228 : // Fix buckets containing the _M_before_begin pointers that can't be
1229 : // moved.
1230 : if (_M_begin())
1231 : _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
1232 : __ht._M_reset();
1233 : }
1234 :
1235 : template<typename _Key, typename _Value,
1236 : typename _Alloc, typename _ExtractKey, typename _Equal,
1237 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1238 : typename _Traits>
1239 : void
1240 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1241 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1242 : _M_move_assign(_Hashtable&& __ht, std::false_type)
1243 : {
1244 : if (__ht._M_node_allocator() == this->_M_node_allocator())
1245 : _M_move_assign(std::move(__ht), std::true_type());
1246 : else
1247 : {
1248 : // Can't move memory, move elements then.
1249 : _M_assign_elements(std::move(__ht),
1250 : [](const __reuse_or_alloc_node_type& __roan, __node_type* __n)
1251 : { return __roan(std::move_if_noexcept(__n->_M_v())); });
1252 : __ht.clear();
1253 : }
1254 : }
1255 :
1256 : template<typename _Key, typename _Value,
1257 : typename _Alloc, typename _ExtractKey, typename _Equal,
1258 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1259 : typename _Traits>
1260 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1261 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1262 : _Hashtable(const _Hashtable& __ht)
1263 : : __hashtable_base(__ht),
1264 : __map_base(__ht),
1265 : __rehash_base(__ht),
1266 : __hashtable_alloc(
1267 : __node_alloc_traits::_S_select_on_copy(__ht._M_node_allocator())),
1268 : _M_buckets(nullptr),
1269 : _M_bucket_count(__ht._M_bucket_count),
1270 : _M_element_count(__ht._M_element_count),
1271 : _M_rehash_policy(__ht._M_rehash_policy)
1272 : {
1273 : _M_assign(__ht,
1274 : [this](const __node_type* __n)
1275 : { return this->_M_allocate_node(__n->_M_v()); });
1276 : }
1277 :
1278 : template<typename _Key, typename _Value,
1279 : typename _Alloc, typename _ExtractKey, typename _Equal,
1280 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1281 : typename _Traits>
1282 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1283 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1284 : _Hashtable(_Hashtable&& __ht, __node_alloc_type&& __a,
1285 : true_type /* alloc always equal */)
1286 : noexcept(_S_nothrow_move())
1287 : : __hashtable_base(__ht),
1288 : __map_base(__ht),
1289 : __rehash_base(__ht),
1290 : __hashtable_alloc(std::move(__a)),
1291 : _M_buckets(__ht._M_buckets),
1292 : _M_bucket_count(__ht._M_bucket_count),
1293 : _M_before_begin(__ht._M_before_begin._M_nxt),
1294 : _M_element_count(__ht._M_element_count),
1295 : _M_rehash_policy(__ht._M_rehash_policy)
1296 : {
1297 : // Update buckets if __ht is using its single bucket.
1298 : if (__ht._M_uses_single_bucket())
1299 : {
1300 : _M_buckets = &_M_single_bucket;
1301 : _M_single_bucket = __ht._M_single_bucket;
1302 : }
1303 :
1304 : // Update, if necessary, bucket pointing to before begin that hasn't
1305 : // moved.
1306 : if (_M_begin())
1307 : _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
1308 :
1309 : __ht._M_reset();
1310 : }
1311 :
1312 : template<typename _Key, typename _Value,
1313 : typename _Alloc, typename _ExtractKey, typename _Equal,
1314 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1315 : typename _Traits>
1316 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1317 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1318 : _Hashtable(const _Hashtable& __ht, const allocator_type& __a)
1319 : : __hashtable_base(__ht),
1320 : __map_base(__ht),
1321 : __rehash_base(__ht),
1322 : __hashtable_alloc(__node_alloc_type(__a)),
1323 : _M_buckets(),
1324 : _M_bucket_count(__ht._M_bucket_count),
1325 : _M_element_count(__ht._M_element_count),
1326 : _M_rehash_policy(__ht._M_rehash_policy)
1327 : {
1328 : _M_assign(__ht,
1329 : [this](const __node_type* __n)
1330 : { return this->_M_allocate_node(__n->_M_v()); });
1331 : }
1332 :
1333 : template<typename _Key, typename _Value,
1334 : typename _Alloc, typename _ExtractKey, typename _Equal,
1335 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1336 : typename _Traits>
1337 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1338 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1339 : _Hashtable(_Hashtable&& __ht, __node_alloc_type&& __a,
1340 : false_type /* alloc always equal */)
1341 : : __hashtable_base(__ht),
1342 : __map_base(__ht),
1343 : __rehash_base(__ht),
1344 : __hashtable_alloc(std::move(__a)),
1345 : _M_buckets(nullptr),
1346 : _M_bucket_count(__ht._M_bucket_count),
1347 : _M_element_count(__ht._M_element_count),
1348 : _M_rehash_policy(__ht._M_rehash_policy)
1349 : {
1350 : if (__ht._M_node_allocator() == this->_M_node_allocator())
1351 : {
1352 : if (__ht._M_uses_single_bucket())
1353 : {
1354 : _M_buckets = &_M_single_bucket;
1355 : _M_single_bucket = __ht._M_single_bucket;
1356 : }
1357 : else
1358 : _M_buckets = __ht._M_buckets;
1359 :
1360 : _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt;
1361 : // Update, if necessary, bucket pointing to before begin that hasn't
1362 : // moved.
1363 : if (_M_begin())
1364 : _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
1365 : __ht._M_reset();
1366 : }
1367 : else
1368 : {
1369 : _M_assign(__ht,
1370 : [this](__node_type* __n)
1371 : {
1372 : return this->_M_allocate_node(
1373 : std::move_if_noexcept(__n->_M_v()));
1374 : });
1375 : __ht.clear();
1376 : }
1377 : }
1378 :
1379 : template<typename _Key, typename _Value,
1380 : typename _Alloc, typename _ExtractKey, typename _Equal,
1381 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1382 : typename _Traits>
1383 712 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1384 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1385 : ~_Hashtable() noexcept
1386 : {
1387 712 : clear();
1388 712 : _M_deallocate_buckets();
1389 712 : }
1390 :
1391 : template<typename _Key, typename _Value,
1392 : typename _Alloc, typename _ExtractKey, typename _Equal,
1393 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1394 : typename _Traits>
1395 : void
1396 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1397 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1398 : swap(_Hashtable& __x)
1399 : noexcept(__and_<__is_nothrow_swappable<_H1>,
1400 : __is_nothrow_swappable<_Equal>>::value)
1401 : {
1402 : // The only base class with member variables is hash_code_base.
1403 : // We define _Hash_code_base::_M_swap because different
1404 : // specializations have different members.
1405 : this->_M_swap(__x);
1406 :
1407 : std::__alloc_on_swap(this->_M_node_allocator(), __x._M_node_allocator());
1408 : std::swap(_M_rehash_policy, __x._M_rehash_policy);
1409 :
1410 : // Deal properly with potentially moved instances.
1411 : if (this->_M_uses_single_bucket())
1412 : {
1413 : if (!__x._M_uses_single_bucket())
1414 : {
1415 : _M_buckets = __x._M_buckets;
1416 : __x._M_buckets = &__x._M_single_bucket;
1417 : }
1418 : }
1419 : else if (__x._M_uses_single_bucket())
1420 : {
1421 : __x._M_buckets = _M_buckets;
1422 : _M_buckets = &_M_single_bucket;
1423 : }
1424 : else
1425 : std::swap(_M_buckets, __x._M_buckets);
1426 :
1427 : std::swap(_M_bucket_count, __x._M_bucket_count);
1428 : std::swap(_M_before_begin._M_nxt, __x._M_before_begin._M_nxt);
1429 : std::swap(_M_element_count, __x._M_element_count);
1430 : std::swap(_M_single_bucket, __x._M_single_bucket);
1431 :
1432 : // Fix buckets containing the _M_before_begin pointers that can't be
1433 : // swapped.
1434 : if (_M_begin())
1435 : _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin;
1436 :
1437 : if (__x._M_begin())
1438 : __x._M_buckets[__x._M_bucket_index(__x._M_begin())]
1439 : = &__x._M_before_begin;
1440 : }
1441 :
1442 : template<typename _Key, typename _Value,
1443 : typename _Alloc, typename _ExtractKey, typename _Equal,
1444 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1445 : typename _Traits>
1446 : auto
1447 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1448 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1449 : find(const key_type& __k)
1450 : -> iterator
1451 : {
1452 : __hash_code __code = this->_M_hash_code(__k);
1453 : std::size_t __n = _M_bucket_index(__k, __code);
1454 : __node_type* __p = _M_find_node(__n, __k, __code);
1455 : return __p ? iterator(__p) : end();
1456 : }
1457 :
1458 : template<typename _Key, typename _Value,
1459 : typename _Alloc, typename _ExtractKey, typename _Equal,
1460 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1461 : typename _Traits>
1462 : auto
1463 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1464 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1465 : find(const key_type& __k) const
1466 : -> const_iterator
1467 : {
1468 : __hash_code __code = this->_M_hash_code(__k);
1469 : std::size_t __n = _M_bucket_index(__k, __code);
1470 : __node_type* __p = _M_find_node(__n, __k, __code);
1471 : return __p ? const_iterator(__p) : end();
1472 : }
1473 :
1474 : template<typename _Key, typename _Value,
1475 : typename _Alloc, typename _ExtractKey, typename _Equal,
1476 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1477 : typename _Traits>
1478 : auto
1479 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1480 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1481 : count(const key_type& __k) const
1482 : -> size_type
1483 : {
1484 : __hash_code __code = this->_M_hash_code(__k);
1485 : std::size_t __n = _M_bucket_index(__k, __code);
1486 : __node_type* __p = _M_bucket_begin(__n);
1487 : if (!__p)
1488 : return 0;
1489 :
1490 : std::size_t __result = 0;
1491 : for (;; __p = __p->_M_next())
1492 : {
1493 : if (this->_M_equals(__k, __code, __p))
1494 : ++__result;
1495 : else if (__result)
1496 : // All equivalent values are next to each other, if we
1497 : // found a non-equivalent value after an equivalent one it
1498 : // means that we won't find any new equivalent value.
1499 : break;
1500 : if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n)
1501 : break;
1502 : }
1503 : return __result;
1504 : }
1505 :
1506 : template<typename _Key, typename _Value,
1507 : typename _Alloc, typename _ExtractKey, typename _Equal,
1508 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1509 : typename _Traits>
1510 : auto
1511 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1512 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1513 : equal_range(const key_type& __k)
1514 : -> pair<iterator, iterator>
1515 : {
1516 : __hash_code __code = this->_M_hash_code(__k);
1517 : std::size_t __n = _M_bucket_index(__k, __code);
1518 : __node_type* __p = _M_find_node(__n, __k, __code);
1519 :
1520 : if (__p)
1521 : {
1522 : __node_type* __p1 = __p->_M_next();
1523 : while (__p1 && _M_bucket_index(__p1) == __n
1524 : && this->_M_equals(__k, __code, __p1))
1525 : __p1 = __p1->_M_next();
1526 :
1527 : return std::make_pair(iterator(__p), iterator(__p1));
1528 : }
1529 : else
1530 : return std::make_pair(end(), end());
1531 : }
1532 :
1533 : template<typename _Key, typename _Value,
1534 : typename _Alloc, typename _ExtractKey, typename _Equal,
1535 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1536 : typename _Traits>
1537 : auto
1538 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1539 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1540 : equal_range(const key_type& __k) const
1541 : -> pair<const_iterator, const_iterator>
1542 : {
1543 : __hash_code __code = this->_M_hash_code(__k);
1544 : std::size_t __n = _M_bucket_index(__k, __code);
1545 : __node_type* __p = _M_find_node(__n, __k, __code);
1546 :
1547 : if (__p)
1548 : {
1549 : __node_type* __p1 = __p->_M_next();
1550 : while (__p1 && _M_bucket_index(__p1) == __n
1551 : && this->_M_equals(__k, __code, __p1))
1552 : __p1 = __p1->_M_next();
1553 :
1554 : return std::make_pair(const_iterator(__p), const_iterator(__p1));
1555 : }
1556 : else
1557 : return std::make_pair(end(), end());
1558 : }
1559 :
1560 : // Find the node whose key compares equal to k in the bucket n.
1561 : // Return nullptr if no node is found.
1562 : template<typename _Key, typename _Value,
1563 : typename _Alloc, typename _ExtractKey, typename _Equal,
1564 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1565 : typename _Traits>
1566 : auto
1567 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1568 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1569 : _M_find_before_node(size_type __n, const key_type& __k,
1570 : __hash_code __code) const
1571 : -> __node_base*
1572 : {
1573 : __node_base* __prev_p = _M_buckets[__n];
1574 : if (!__prev_p)
1575 : return nullptr;
1576 :
1577 : for (__node_type* __p = static_cast<__node_type*>(__prev_p->_M_nxt);;
1578 : __p = __p->_M_next())
1579 : {
1580 : if (this->_M_equals(__k, __code, __p))
1581 : return __prev_p;
1582 :
1583 : if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n)
1584 : break;
1585 : __prev_p = __p;
1586 : }
1587 : return nullptr;
1588 : }
1589 :
1590 : template<typename _Key, typename _Value,
1591 : typename _Alloc, typename _ExtractKey, typename _Equal,
1592 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1593 : typename _Traits>
1594 : void
1595 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1596 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1597 : _M_insert_bucket_begin(size_type __bkt, __node_type* __node)
1598 : {
1599 : if (_M_buckets[__bkt])
1600 : {
1601 : // Bucket is not empty, we just need to insert the new node
1602 : // after the bucket before begin.
1603 : __node->_M_nxt = _M_buckets[__bkt]->_M_nxt;
1604 : _M_buckets[__bkt]->_M_nxt = __node;
1605 : }
1606 : else
1607 : {
1608 : // The bucket is empty, the new node is inserted at the
1609 : // beginning of the singly-linked list and the bucket will
1610 : // contain _M_before_begin pointer.
1611 : __node->_M_nxt = _M_before_begin._M_nxt;
1612 : _M_before_begin._M_nxt = __node;
1613 : if (__node->_M_nxt)
1614 : // We must update former begin bucket that is pointing to
1615 : // _M_before_begin.
1616 : _M_buckets[_M_bucket_index(__node->_M_next())] = __node;
1617 : _M_buckets[__bkt] = &_M_before_begin;
1618 : }
1619 : }
1620 :
1621 : template<typename _Key, typename _Value,
1622 : typename _Alloc, typename _ExtractKey, typename _Equal,
1623 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1624 : typename _Traits>
1625 : void
1626 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1627 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1628 : _M_remove_bucket_begin(size_type __bkt, __node_type* __next,
1629 : size_type __next_bkt)
1630 : {
1631 : if (!__next || __next_bkt != __bkt)
1632 : {
1633 : // Bucket is now empty
1634 : // First update next bucket if any
1635 : if (__next)
1636 : _M_buckets[__next_bkt] = _M_buckets[__bkt];
1637 :
1638 : // Second update before begin node if necessary
1639 : if (&_M_before_begin == _M_buckets[__bkt])
1640 : _M_before_begin._M_nxt = __next;
1641 : _M_buckets[__bkt] = nullptr;
1642 : }
1643 : }
1644 :
1645 : template<typename _Key, typename _Value,
1646 : typename _Alloc, typename _ExtractKey, typename _Equal,
1647 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1648 : typename _Traits>
1649 : auto
1650 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1651 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1652 : _M_get_previous_node(size_type __bkt, __node_base* __n)
1653 : -> __node_base*
1654 : {
1655 : __node_base* __prev_n = _M_buckets[__bkt];
1656 : while (__prev_n->_M_nxt != __n)
1657 : __prev_n = __prev_n->_M_nxt;
1658 : return __prev_n;
1659 : }
1660 :
1661 : template<typename _Key, typename _Value,
1662 : typename _Alloc, typename _ExtractKey, typename _Equal,
1663 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1664 : typename _Traits>
1665 : template<typename... _Args>
1666 : auto
1667 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1668 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1669 : _M_emplace(std::true_type, _Args&&... __args)
1670 : -> pair<iterator, bool>
1671 : {
1672 : // First build the node to get access to the hash code
1673 : __node_type* __node = this->_M_allocate_node(std::forward<_Args>(__args)...);
1674 : const key_type& __k = this->_M_extract()(__node->_M_v());
1675 : __hash_code __code;
1676 : __try
1677 : {
1678 : __code = this->_M_hash_code(__k);
1679 : }
1680 : __catch(...)
1681 : {
1682 : this->_M_deallocate_node(__node);
1683 : __throw_exception_again;
1684 : }
1685 :
1686 : size_type __bkt = _M_bucket_index(__k, __code);
1687 : if (__node_type* __p = _M_find_node(__bkt, __k, __code))
1688 : {
1689 : // There is already an equivalent node, no insertion
1690 : this->_M_deallocate_node(__node);
1691 : return std::make_pair(iterator(__p), false);
1692 : }
1693 :
1694 : // Insert the node
1695 : return std::make_pair(_M_insert_unique_node(__bkt, __code, __node),
1696 : true);
1697 : }
1698 :
1699 : template<typename _Key, typename _Value,
1700 : typename _Alloc, typename _ExtractKey, typename _Equal,
1701 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1702 : typename _Traits>
1703 : template<typename... _Args>
1704 : auto
1705 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1706 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1707 : _M_emplace(const_iterator __hint, std::false_type, _Args&&... __args)
1708 : -> iterator
1709 : {
1710 : // First build the node to get its hash code.
1711 : __node_type* __node =
1712 : this->_M_allocate_node(std::forward<_Args>(__args)...);
1713 :
1714 : __hash_code __code;
1715 : __try
1716 : {
1717 : __code = this->_M_hash_code(this->_M_extract()(__node->_M_v()));
1718 : }
1719 : __catch(...)
1720 : {
1721 : this->_M_deallocate_node(__node);
1722 : __throw_exception_again;
1723 : }
1724 :
1725 : return _M_insert_multi_node(__hint._M_cur, __code, __node);
1726 : }
1727 :
1728 : template<typename _Key, typename _Value,
1729 : typename _Alloc, typename _ExtractKey, typename _Equal,
1730 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1731 : typename _Traits>
1732 : auto
1733 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1734 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1735 : _M_insert_unique_node(size_type __bkt, __hash_code __code,
1736 : __node_type* __node, size_type __n_elt)
1737 : -> iterator
1738 : {
1739 : const __rehash_state& __saved_state = _M_rehash_policy._M_state();
1740 : std::pair<bool, std::size_t> __do_rehash
1741 : = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count,
1742 : __n_elt);
1743 :
1744 : __try
1745 : {
1746 : if (__do_rehash.first)
1747 : {
1748 : _M_rehash(__do_rehash.second, __saved_state);
1749 : __bkt = _M_bucket_index(this->_M_extract()(__node->_M_v()), __code);
1750 : }
1751 :
1752 : this->_M_store_code(__node, __code);
1753 :
1754 : // Always insert at the beginning of the bucket.
1755 : _M_insert_bucket_begin(__bkt, __node);
1756 : ++_M_element_count;
1757 : return iterator(__node);
1758 : }
1759 : __catch(...)
1760 : {
1761 : this->_M_deallocate_node(__node);
1762 : __throw_exception_again;
1763 : }
1764 : }
1765 :
1766 : // Insert node, in bucket bkt if no rehash (assumes no element with its key
1767 : // already present). Take ownership of the node, deallocate it on exception.
1768 : template<typename _Key, typename _Value,
1769 : typename _Alloc, typename _ExtractKey, typename _Equal,
1770 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1771 : typename _Traits>
1772 : auto
1773 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1774 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1775 : _M_insert_multi_node(__node_type* __hint, __hash_code __code,
1776 : __node_type* __node)
1777 : -> iterator
1778 : {
1779 : const __rehash_state& __saved_state = _M_rehash_policy._M_state();
1780 : std::pair<bool, std::size_t> __do_rehash
1781 : = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 1);
1782 :
1783 : __try
1784 : {
1785 : if (__do_rehash.first)
1786 : _M_rehash(__do_rehash.second, __saved_state);
1787 :
1788 : this->_M_store_code(__node, __code);
1789 : const key_type& __k = this->_M_extract()(__node->_M_v());
1790 : size_type __bkt = _M_bucket_index(__k, __code);
1791 :
1792 : // Find the node before an equivalent one or use hint if it exists and
1793 : // if it is equivalent.
1794 : __node_base* __prev
1795 : = __builtin_expect(__hint != nullptr, false)
1796 : && this->_M_equals(__k, __code, __hint)
1797 : ? __hint
1798 : : _M_find_before_node(__bkt, __k, __code);
1799 : if (__prev)
1800 : {
1801 : // Insert after the node before the equivalent one.
1802 : __node->_M_nxt = __prev->_M_nxt;
1803 : __prev->_M_nxt = __node;
1804 : if (__builtin_expect(__prev == __hint, false))
1805 : // hint might be the last bucket node, in this case we need to
1806 : // update next bucket.
1807 : if (__node->_M_nxt
1808 : && !this->_M_equals(__k, __code, __node->_M_next()))
1809 : {
1810 : size_type __next_bkt = _M_bucket_index(__node->_M_next());
1811 : if (__next_bkt != __bkt)
1812 : _M_buckets[__next_bkt] = __node;
1813 : }
1814 : }
1815 : else
1816 : // The inserted node has no equivalent in the
1817 : // hashtable. We must insert the new node at the
1818 : // beginning of the bucket to preserve equivalent
1819 : // elements' relative positions.
1820 : _M_insert_bucket_begin(__bkt, __node);
1821 : ++_M_element_count;
1822 : return iterator(__node);
1823 : }
1824 : __catch(...)
1825 : {
1826 : this->_M_deallocate_node(__node);
1827 : __throw_exception_again;
1828 : }
1829 : }
1830 :
1831 : // Insert v if no element with its key is already present.
1832 : template<typename _Key, typename _Value,
1833 : typename _Alloc, typename _ExtractKey, typename _Equal,
1834 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1835 : typename _Traits>
1836 : template<typename _Arg, typename _NodeGenerator>
1837 : auto
1838 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1839 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1840 : _M_insert(_Arg&& __v, const _NodeGenerator& __node_gen, true_type,
1841 : size_type __n_elt)
1842 : -> pair<iterator, bool>
1843 : {
1844 : const key_type& __k = this->_M_extract()(__v);
1845 : __hash_code __code = this->_M_hash_code(__k);
1846 : size_type __bkt = _M_bucket_index(__k, __code);
1847 :
1848 : __node_type* __n = _M_find_node(__bkt, __k, __code);
1849 : if (__n)
1850 : return std::make_pair(iterator(__n), false);
1851 :
1852 : __n = __node_gen(std::forward<_Arg>(__v));
1853 : return { _M_insert_unique_node(__bkt, __code, __n, __n_elt), true };
1854 : }
1855 :
1856 : // Insert v unconditionally.
1857 : template<typename _Key, typename _Value,
1858 : typename _Alloc, typename _ExtractKey, typename _Equal,
1859 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1860 : typename _Traits>
1861 : template<typename _Arg, typename _NodeGenerator>
1862 : auto
1863 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1864 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1865 : _M_insert(const_iterator __hint, _Arg&& __v,
1866 : const _NodeGenerator& __node_gen, false_type)
1867 : -> iterator
1868 : {
1869 : // First compute the hash code so that we don't do anything if it
1870 : // throws.
1871 : __hash_code __code = this->_M_hash_code(this->_M_extract()(__v));
1872 :
1873 : // Second allocate new node so that we don't rehash if it throws.
1874 : __node_type* __node = __node_gen(std::forward<_Arg>(__v));
1875 :
1876 : return _M_insert_multi_node(__hint._M_cur, __code, __node);
1877 : }
1878 :
1879 : template<typename _Key, typename _Value,
1880 : typename _Alloc, typename _ExtractKey, typename _Equal,
1881 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1882 : typename _Traits>
1883 : auto
1884 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1885 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1886 : erase(const_iterator __it)
1887 : -> iterator
1888 : {
1889 : __node_type* __n = __it._M_cur;
1890 : std::size_t __bkt = _M_bucket_index(__n);
1891 :
1892 : // Look for previous node to unlink it from the erased one, this
1893 : // is why we need buckets to contain the before begin to make
1894 : // this search fast.
1895 : __node_base* __prev_n = _M_get_previous_node(__bkt, __n);
1896 : return _M_erase(__bkt, __prev_n, __n);
1897 : }
1898 :
1899 : template<typename _Key, typename _Value,
1900 : typename _Alloc, typename _ExtractKey, typename _Equal,
1901 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1902 : typename _Traits>
1903 : auto
1904 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1905 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1906 : _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n)
1907 : -> iterator
1908 : {
1909 : if (__prev_n == _M_buckets[__bkt])
1910 : _M_remove_bucket_begin(__bkt, __n->_M_next(),
1911 : __n->_M_nxt ? _M_bucket_index(__n->_M_next()) : 0);
1912 : else if (__n->_M_nxt)
1913 : {
1914 : size_type __next_bkt = _M_bucket_index(__n->_M_next());
1915 : if (__next_bkt != __bkt)
1916 : _M_buckets[__next_bkt] = __prev_n;
1917 : }
1918 :
1919 : __prev_n->_M_nxt = __n->_M_nxt;
1920 : iterator __result(__n->_M_next());
1921 : this->_M_deallocate_node(__n);
1922 : --_M_element_count;
1923 :
1924 : return __result;
1925 : }
1926 :
1927 : template<typename _Key, typename _Value,
1928 : typename _Alloc, typename _ExtractKey, typename _Equal,
1929 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1930 : typename _Traits>
1931 : auto
1932 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1933 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1934 : _M_erase(std::true_type, const key_type& __k)
1935 : -> size_type
1936 : {
1937 : __hash_code __code = this->_M_hash_code(__k);
1938 : std::size_t __bkt = _M_bucket_index(__k, __code);
1939 :
1940 : // Look for the node before the first matching node.
1941 : __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code);
1942 : if (!__prev_n)
1943 : return 0;
1944 :
1945 : // We found a matching node, erase it.
1946 : __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt);
1947 : _M_erase(__bkt, __prev_n, __n);
1948 : return 1;
1949 : }
1950 :
1951 : template<typename _Key, typename _Value,
1952 : typename _Alloc, typename _ExtractKey, typename _Equal,
1953 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
1954 : typename _Traits>
1955 : auto
1956 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1957 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
1958 : _M_erase(std::false_type, const key_type& __k)
1959 : -> size_type
1960 : {
1961 : __hash_code __code = this->_M_hash_code(__k);
1962 : std::size_t __bkt = _M_bucket_index(__k, __code);
1963 :
1964 : // Look for the node before the first matching node.
1965 : __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code);
1966 : if (!__prev_n)
1967 : return 0;
1968 :
1969 : // _GLIBCXX_RESOLVE_LIB_DEFECTS
1970 : // 526. Is it undefined if a function in the standard changes
1971 : // in parameters?
1972 : // We use one loop to find all matching nodes and another to deallocate
1973 : // them so that the key stays valid during the first loop. It might be
1974 : // invalidated indirectly when destroying nodes.
1975 : __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt);
1976 : __node_type* __n_last = __n;
1977 : std::size_t __n_last_bkt = __bkt;
1978 : do
1979 : {
1980 : __n_last = __n_last->_M_next();
1981 : if (!__n_last)
1982 : break;
1983 : __n_last_bkt = _M_bucket_index(__n_last);
1984 : }
1985 : while (__n_last_bkt == __bkt && this->_M_equals(__k, __code, __n_last));
1986 :
1987 : // Deallocate nodes.
1988 : size_type __result = 0;
1989 : do
1990 : {
1991 : __node_type* __p = __n->_M_next();
1992 : this->_M_deallocate_node(__n);
1993 : __n = __p;
1994 : ++__result;
1995 : --_M_element_count;
1996 : }
1997 : while (__n != __n_last);
1998 :
1999 : if (__prev_n == _M_buckets[__bkt])
2000 : _M_remove_bucket_begin(__bkt, __n_last, __n_last_bkt);
2001 : else if (__n_last && __n_last_bkt != __bkt)
2002 : _M_buckets[__n_last_bkt] = __prev_n;
2003 : __prev_n->_M_nxt = __n_last;
2004 : return __result;
2005 : }
2006 :
2007 : template<typename _Key, typename _Value,
2008 : typename _Alloc, typename _ExtractKey, typename _Equal,
2009 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
2010 : typename _Traits>
2011 : auto
2012 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
2013 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
2014 : erase(const_iterator __first, const_iterator __last)
2015 : -> iterator
2016 : {
2017 : __node_type* __n = __first._M_cur;
2018 : __node_type* __last_n = __last._M_cur;
2019 : if (__n == __last_n)
2020 : return iterator(__n);
2021 :
2022 : std::size_t __bkt = _M_bucket_index(__n);
2023 :
2024 : __node_base* __prev_n = _M_get_previous_node(__bkt, __n);
2025 : bool __is_bucket_begin = __n == _M_bucket_begin(__bkt);
2026 : std::size_t __n_bkt = __bkt;
2027 : for (;;)
2028 : {
2029 : do
2030 : {
2031 : __node_type* __tmp = __n;
2032 : __n = __n->_M_next();
2033 : this->_M_deallocate_node(__tmp);
2034 : --_M_element_count;
2035 : if (!__n)
2036 : break;
2037 : __n_bkt = _M_bucket_index(__n);
2038 : }
2039 : while (__n != __last_n && __n_bkt == __bkt);
2040 : if (__is_bucket_begin)
2041 : _M_remove_bucket_begin(__bkt, __n, __n_bkt);
2042 : if (__n == __last_n)
2043 : break;
2044 : __is_bucket_begin = true;
2045 : __bkt = __n_bkt;
2046 : }
2047 :
2048 : if (__n && (__n_bkt != __bkt || __is_bucket_begin))
2049 : _M_buckets[__n_bkt] = __prev_n;
2050 : __prev_n->_M_nxt = __n;
2051 : return iterator(__n);
2052 : }
2053 :
2054 : template<typename _Key, typename _Value,
2055 : typename _Alloc, typename _ExtractKey, typename _Equal,
2056 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
2057 : typename _Traits>
2058 : void
2059 712 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
2060 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
2061 : clear() noexcept
2062 : {
2063 712 : this->_M_deallocate_nodes(_M_begin());
2064 712 : __builtin_memset(_M_buckets, 0, _M_bucket_count * sizeof(__bucket_type));
2065 712 : _M_element_count = 0;
2066 712 : _M_before_begin._M_nxt = nullptr;
2067 712 : }
2068 :
2069 : template<typename _Key, typename _Value,
2070 : typename _Alloc, typename _ExtractKey, typename _Equal,
2071 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
2072 : typename _Traits>
2073 : void
2074 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
2075 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
2076 : rehash(size_type __n)
2077 : {
2078 : const __rehash_state& __saved_state = _M_rehash_policy._M_state();
2079 : std::size_t __buckets
2080 : = std::max(_M_rehash_policy._M_bkt_for_elements(_M_element_count + 1),
2081 : __n);
2082 : __buckets = _M_rehash_policy._M_next_bkt(__buckets);
2083 :
2084 : if (__buckets != _M_bucket_count)
2085 : _M_rehash(__buckets, __saved_state);
2086 : else
2087 : // No rehash, restore previous state to keep a consistent state.
2088 : _M_rehash_policy._M_reset(__saved_state);
2089 : }
2090 :
2091 : template<typename _Key, typename _Value,
2092 : typename _Alloc, typename _ExtractKey, typename _Equal,
2093 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
2094 : typename _Traits>
2095 : void
2096 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
2097 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
2098 : _M_rehash(size_type __n, const __rehash_state& __state)
2099 : {
2100 : __try
2101 : {
2102 : _M_rehash_aux(__n, __unique_keys());
2103 : }
2104 : __catch(...)
2105 : {
2106 : // A failure here means that buckets allocation failed. We only
2107 : // have to restore hash policy previous state.
2108 : _M_rehash_policy._M_reset(__state);
2109 : __throw_exception_again;
2110 : }
2111 : }
2112 :
2113 : // Rehash when there is no equivalent elements.
2114 : template<typename _Key, typename _Value,
2115 : typename _Alloc, typename _ExtractKey, typename _Equal,
2116 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
2117 : typename _Traits>
2118 : void
2119 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
2120 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
2121 : _M_rehash_aux(size_type __n, std::true_type)
2122 : {
2123 : __bucket_type* __new_buckets = _M_allocate_buckets(__n);
2124 : __node_type* __p = _M_begin();
2125 : _M_before_begin._M_nxt = nullptr;
2126 : std::size_t __bbegin_bkt = 0;
2127 : while (__p)
2128 : {
2129 : __node_type* __next = __p->_M_next();
2130 : std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n);
2131 : if (!__new_buckets[__bkt])
2132 : {
2133 : __p->_M_nxt = _M_before_begin._M_nxt;
2134 : _M_before_begin._M_nxt = __p;
2135 : __new_buckets[__bkt] = &_M_before_begin;
2136 : if (__p->_M_nxt)
2137 : __new_buckets[__bbegin_bkt] = __p;
2138 : __bbegin_bkt = __bkt;
2139 : }
2140 : else
2141 : {
2142 : __p->_M_nxt = __new_buckets[__bkt]->_M_nxt;
2143 : __new_buckets[__bkt]->_M_nxt = __p;
2144 : }
2145 : __p = __next;
2146 : }
2147 :
2148 : _M_deallocate_buckets();
2149 : _M_bucket_count = __n;
2150 : _M_buckets = __new_buckets;
2151 : }
2152 :
2153 : // Rehash when there can be equivalent elements, preserve their relative
2154 : // order.
2155 : template<typename _Key, typename _Value,
2156 : typename _Alloc, typename _ExtractKey, typename _Equal,
2157 : typename _H1, typename _H2, typename _Hash, typename _RehashPolicy,
2158 : typename _Traits>
2159 : void
2160 : _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
2161 : _H1, _H2, _Hash, _RehashPolicy, _Traits>::
2162 : _M_rehash_aux(size_type __n, std::false_type)
2163 : {
2164 : __bucket_type* __new_buckets = _M_allocate_buckets(__n);
2165 :
2166 : __node_type* __p = _M_begin();
2167 : _M_before_begin._M_nxt = nullptr;
2168 : std::size_t __bbegin_bkt = 0;
2169 : std::size_t __prev_bkt = 0;
2170 : __node_type* __prev_p = nullptr;
2171 : bool __check_bucket = false;
2172 :
2173 : while (__p)
2174 : {
2175 : __node_type* __next = __p->_M_next();
2176 : std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n);
2177 :
2178 : if (__prev_p && __prev_bkt == __bkt)
2179 : {
2180 : // Previous insert was already in this bucket, we insert after
2181 : // the previously inserted one to preserve equivalent elements
2182 : // relative order.
2183 : __p->_M_nxt = __prev_p->_M_nxt;
2184 : __prev_p->_M_nxt = __p;
2185 :
2186 : // Inserting after a node in a bucket require to check that we
2187 : // haven't change the bucket last node, in this case next
2188 : // bucket containing its before begin node must be updated. We
2189 : // schedule a check as soon as we move out of the sequence of
2190 : // equivalent nodes to limit the number of checks.
2191 : __check_bucket = true;
2192 : }
2193 : else
2194 : {
2195 : if (__check_bucket)
2196 : {
2197 : // Check if we shall update the next bucket because of
2198 : // insertions into __prev_bkt bucket.
2199 : if (__prev_p->_M_nxt)
2200 : {
2201 : std::size_t __next_bkt
2202 : = __hash_code_base::_M_bucket_index(__prev_p->_M_next(),
2203 : __n);
2204 : if (__next_bkt != __prev_bkt)
2205 : __new_buckets[__next_bkt] = __prev_p;
2206 : }
2207 : __check_bucket = false;
2208 : }
2209 :
2210 : if (!__new_buckets[__bkt])
2211 : {
2212 : __p->_M_nxt = _M_before_begin._M_nxt;
2213 : _M_before_begin._M_nxt = __p;
2214 : __new_buckets[__bkt] = &_M_before_begin;
2215 : if (__p->_M_nxt)
2216 : __new_buckets[__bbegin_bkt] = __p;
2217 : __bbegin_bkt = __bkt;
2218 : }
2219 : else
2220 : {
2221 : __p->_M_nxt = __new_buckets[__bkt]->_M_nxt;
2222 : __new_buckets[__bkt]->_M_nxt = __p;
2223 : }
2224 : }
2225 : __prev_p = __p;
2226 : __prev_bkt = __bkt;
2227 : __p = __next;
2228 : }
2229 :
2230 : if (__check_bucket && __prev_p->_M_nxt)
2231 : {
2232 : std::size_t __next_bkt
2233 : = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), __n);
2234 : if (__next_bkt != __prev_bkt)
2235 : __new_buckets[__next_bkt] = __prev_p;
2236 : }
2237 :
2238 : _M_deallocate_buckets();
2239 : _M_bucket_count = __n;
2240 : _M_buckets = __new_buckets;
2241 : }
2242 :
2243 : #if __cplusplus > 201402L
2244 : template<typename, typename, typename> class _Hash_merge_helper { };
2245 : #endif // C++17
2246 :
2247 : #if __cpp_deduction_guides >= 201606
2248 : // Used to constrain deduction guides
2249 : template<typename _Hash>
2250 : using _RequireNotAllocatorOrIntegral
2251 : = __enable_if_t<!__or_<is_integral<_Hash>, __is_allocator<_Hash>>::value>;
2252 : #endif
2253 :
2254 : _GLIBCXX_END_NAMESPACE_VERSION
2255 : } // namespace std
2256 :
2257 : #endif // _HASHTABLE_H
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