1// Internal policy header for unordered_set and unordered_map -*- C++ -*-
2
3// Copyright (C) 2010-2019 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_policy.h
26 * This is an internal header file, included by other library headers.
27 * Do not attempt to use it directly.
28 * @headername{unordered_map,unordered_set}
29 */
30
31#ifndef _HASHTABLE_POLICY_H
32#define _HASHTABLE_POLICY_H 1
33
34#include <tuple> // for std::tuple, std::forward_as_tuple
35#include <limits> // for std::numeric_limits
36#include <bits/stl_algobase.h> // for std::min.
37
38namespace std _GLIBCXX_VISIBILITY(default)
39{
40_GLIBCXX_BEGIN_NAMESPACE_VERSION
41
42 template<typename _Key, typename _Value, typename _Alloc,
43 typename _ExtractKey, typename _Equal,
44 typename _H1, typename _H2, typename _Hash,
45 typename _RehashPolicy, typename _Traits>
46 class _Hashtable;
47
48namespace __detail
49{
50 /**
51 * @defgroup hashtable-detail Base and Implementation Classes
52 * @ingroup unordered_associative_containers
53 * @{
54 */
55 template<typename _Key, typename _Value,
56 typename _ExtractKey, typename _Equal,
57 typename _H1, typename _H2, typename _Hash, typename _Traits>
58 struct _Hashtable_base;
59
60 // Helper function: return distance(first, last) for forward
61 // iterators, or 0/1 for input iterators.
62 template<class _Iterator>
63 inline typename std::iterator_traits<_Iterator>::difference_type
64 __distance_fw(_Iterator __first, _Iterator __last,
65 std::input_iterator_tag)
66 { return __first != __last ? 1 : 0; }
67
68 template<class _Iterator>
69 inline typename std::iterator_traits<_Iterator>::difference_type
70 __distance_fw(_Iterator __first, _Iterator __last,
71 std::forward_iterator_tag)
72 { return std::distance(__first, __last); }
73
74 template<class _Iterator>
75 inline typename std::iterator_traits<_Iterator>::difference_type
76 __distance_fw(_Iterator __first, _Iterator __last)
77 { return __distance_fw(__first, __last,
78 std::__iterator_category(__first)); }
79
80 struct _Identity
81 {
82 template<typename _Tp>
83 _Tp&&
84 operator()(_Tp&& __x) const
85 { return std::forward<_Tp>(__x); }
86 };
87
88 struct _Select1st
89 {
90 template<typename _Tp>
91 auto
92 operator()(_Tp&& __x) const
93 -> decltype(std::get<0>(std::forward<_Tp>(__x)))
94 { return std::get<0>(std::forward<_Tp>(__x)); }
95 };
96
97 template<typename _NodeAlloc>
98 struct _Hashtable_alloc;
99
100 // Functor recycling a pool of nodes and using allocation once the pool is
101 // empty.
102 template<typename _NodeAlloc>
103 struct _ReuseOrAllocNode
104 {
105 private:
106 using __node_alloc_type = _NodeAlloc;
107 using __hashtable_alloc = _Hashtable_alloc<__node_alloc_type>;
108 using __node_alloc_traits =
109 typename __hashtable_alloc::__node_alloc_traits;
110 using __node_type = typename __hashtable_alloc::__node_type;
111
112 public:
113 _ReuseOrAllocNode(__node_type* __nodes, __hashtable_alloc& __h)
114 : _M_nodes(__nodes), _M_h(__h) { }
115 _ReuseOrAllocNode(const _ReuseOrAllocNode&) = delete;
116
117 ~_ReuseOrAllocNode()
118 { _M_h._M_deallocate_nodes(_M_nodes); }
119
120 template<typename _Arg>
121 __node_type*
122 operator()(_Arg&& __arg) const
123 {
124 if (_M_nodes)
125 {
126 __node_type* __node = _M_nodes;
127 _M_nodes = _M_nodes->_M_next();
128 __node->_M_nxt = nullptr;
129 auto& __a = _M_h._M_node_allocator();
130 __node_alloc_traits::destroy(__a, __node->_M_valptr());
131 __try
132 {
133 __node_alloc_traits::construct(__a, __node->_M_valptr(),
134 std::forward<_Arg>(__arg));
135 }
136 __catch(...)
137 {
138 _M_h._M_deallocate_node_ptr(__node);
139 __throw_exception_again;
140 }
141 return __node;
142 }
143 return _M_h._M_allocate_node(std::forward<_Arg>(__arg));
144 }
145
146 private:
147 mutable __node_type* _M_nodes;
148 __hashtable_alloc& _M_h;
149 };
150
151 // Functor similar to the previous one but without any pool of nodes to
152 // recycle.
153 template<typename _NodeAlloc>
154 struct _AllocNode
155 {
156 private:
157 using __hashtable_alloc = _Hashtable_alloc<_NodeAlloc>;
158 using __node_type = typename __hashtable_alloc::__node_type;
159
160 public:
161 _AllocNode(__hashtable_alloc& __h)
162 : _M_h(__h) { }
163
164 template<typename _Arg>
165 __node_type*
166 operator()(_Arg&& __arg) const
167 { return _M_h._M_allocate_node(std::forward<_Arg>(__arg)); }
168
169 private:
170 __hashtable_alloc& _M_h;
171 };
172
173 // Auxiliary types used for all instantiations of _Hashtable nodes
174 // and iterators.
175
176 /**
177 * struct _Hashtable_traits
178 *
179 * Important traits for hash tables.
180 *
181 * @tparam _Cache_hash_code Boolean value. True if the value of
182 * the hash function is stored along with the value. This is a
183 * time-space tradeoff. Storing it may improve lookup speed by
184 * reducing the number of times we need to call the _Equal
185 * function.
186 *
187 * @tparam _Constant_iterators Boolean value. True if iterator and
188 * const_iterator are both constant iterator types. This is true
189 * for unordered_set and unordered_multiset, false for
190 * unordered_map and unordered_multimap.
191 *
192 * @tparam _Unique_keys Boolean value. True if the return value
193 * of _Hashtable::count(k) is always at most one, false if it may
194 * be an arbitrary number. This is true for unordered_set and
195 * unordered_map, false for unordered_multiset and
196 * unordered_multimap.
197 */
198 template<bool _Cache_hash_code, bool _Constant_iterators, bool _Unique_keys>
199 struct _Hashtable_traits
200 {
201 using __hash_cached = __bool_constant<_Cache_hash_code>;
202 using __constant_iterators = __bool_constant<_Constant_iterators>;
203 using __unique_keys = __bool_constant<_Unique_keys>;
204 };
205
206 /**
207 * struct _Hash_node_base
208 *
209 * Nodes, used to wrap elements stored in the hash table. A policy
210 * template parameter of class template _Hashtable controls whether
211 * nodes also store a hash code. In some cases (e.g. strings) this
212 * may be a performance win.
213 */
214 struct _Hash_node_base
215 {
216 _Hash_node_base* _M_nxt;
217
218 _Hash_node_base() noexcept : _M_nxt() { }
219
220 _Hash_node_base(_Hash_node_base* __next) noexcept : _M_nxt(__next) { }
221 };
222
223 /**
224 * struct _Hash_node_value_base
225 *
226 * Node type with the value to store.
227 */
228 template<typename _Value>
229 struct _Hash_node_value_base : _Hash_node_base
230 {
231 typedef _Value value_type;
232
233 __gnu_cxx::__aligned_buffer<_Value> _M_storage;
234
235 _Value*
236 _M_valptr() noexcept
237 { return _M_storage._M_ptr(); }
238
239 const _Value*
240 _M_valptr() const noexcept
241 { return _M_storage._M_ptr(); }
242
243 _Value&
244 _M_v() noexcept
245 { return *_M_valptr(); }
246
247 const _Value&
248 _M_v() const noexcept
249 { return *_M_valptr(); }
250 };
251
252 /**
253 * Primary template struct _Hash_node.
254 */
255 template<typename _Value, bool _Cache_hash_code>
256 struct _Hash_node;
257
258 /**
259 * Specialization for nodes with caches, struct _Hash_node.
260 *
261 * Base class is __detail::_Hash_node_value_base.
262 */
263 template<typename _Value>
264 struct _Hash_node<_Value, true> : _Hash_node_value_base<_Value>
265 {
266 std::size_t _M_hash_code;
267
268 _Hash_node*
269 _M_next() const noexcept
270 { return static_cast<_Hash_node*>(this->_M_nxt); }
271 };
272
273 /**
274 * Specialization for nodes without caches, struct _Hash_node.
275 *
276 * Base class is __detail::_Hash_node_value_base.
277 */
278 template<typename _Value>
279 struct _Hash_node<_Value, false> : _Hash_node_value_base<_Value>
280 {
281 _Hash_node*
282 _M_next() const noexcept
283 { return static_cast<_Hash_node*>(this->_M_nxt); }
284 };
285
286 /// Base class for node iterators.
287 template<typename _Value, bool _Cache_hash_code>
288 struct _Node_iterator_base
289 {
290 using __node_type = _Hash_node<_Value, _Cache_hash_code>;
291
292 __node_type* _M_cur;
293
294 _Node_iterator_base(__node_type* __p) noexcept
295 : _M_cur(__p) { }
296
297 void
298 _M_incr() noexcept
299 { _M_cur = _M_cur->_M_next(); }
300 };
301
302 template<typename _Value, bool _Cache_hash_code>
303 inline bool
304 operator==(const _Node_iterator_base<_Value, _Cache_hash_code>& __x,
305 const _Node_iterator_base<_Value, _Cache_hash_code >& __y)
306 noexcept
307 { return __x._M_cur == __y._M_cur; }
308
309 template<typename _Value, bool _Cache_hash_code>
310 inline bool
311 operator!=(const _Node_iterator_base<_Value, _Cache_hash_code>& __x,
312 const _Node_iterator_base<_Value, _Cache_hash_code>& __y)
313 noexcept
314 { return __x._M_cur != __y._M_cur; }
315
316 /// Node iterators, used to iterate through all the hashtable.
317 template<typename _Value, bool __constant_iterators, bool __cache>
318 struct _Node_iterator
319 : public _Node_iterator_base<_Value, __cache>
320 {
321 private:
322 using __base_type = _Node_iterator_base<_Value, __cache>;
323 using __node_type = typename __base_type::__node_type;
324
325 public:
326 typedef _Value value_type;
327 typedef std::ptrdiff_t difference_type;
328 typedef std::forward_iterator_tag iterator_category;
329
330 using pointer = typename std::conditional<__constant_iterators,
331 const _Value*, _Value*>::type;
332
333 using reference = typename std::conditional<__constant_iterators,
334 const _Value&, _Value&>::type;
335
336 _Node_iterator() noexcept
337 : __base_type(0) { }
338
339 explicit
340 _Node_iterator(__node_type* __p) noexcept
341 : __base_type(__p) { }
342
343 reference
344 operator*() const noexcept
345 { return this->_M_cur->_M_v(); }
346
347 pointer
348 operator->() const noexcept
349 { return this->_M_cur->_M_valptr(); }
350
351 _Node_iterator&
352 operator++() noexcept
353 {
354 this->_M_incr();
355 return *this;
356 }
357
358 _Node_iterator
359 operator++(int) noexcept
360 {
361 _Node_iterator __tmp(*this);
362 this->_M_incr();
363 return __tmp;
364 }
365 };
366
367 /// Node const_iterators, used to iterate through all the hashtable.
368 template<typename _Value, bool __constant_iterators, bool __cache>
369 struct _Node_const_iterator
370 : public _Node_iterator_base<_Value, __cache>
371 {
372 private:
373 using __base_type = _Node_iterator_base<_Value, __cache>;
374 using __node_type = typename __base_type::__node_type;
375
376 public:
377 typedef _Value value_type;
378 typedef std::ptrdiff_t difference_type;
379 typedef std::forward_iterator_tag iterator_category;
380
381 typedef const _Value* pointer;
382 typedef const _Value& reference;
383
384 _Node_const_iterator() noexcept
385 : __base_type(0) { }
386
387 explicit
388 _Node_const_iterator(__node_type* __p) noexcept
389 : __base_type(__p) { }
390
391 _Node_const_iterator(const _Node_iterator<_Value, __constant_iterators,
392 __cache>& __x) noexcept
393 : __base_type(__x._M_cur) { }
394
395 reference
396 operator*() const noexcept
397 { return this->_M_cur->_M_v(); }
398
399 pointer
400 operator->() const noexcept
401 { return this->_M_cur->_M_valptr(); }
402
403 _Node_const_iterator&
404 operator++() noexcept
405 {
406 this->_M_incr();
407 return *this;
408 }
409
410 _Node_const_iterator
411 operator++(int) noexcept
412 {
413 _Node_const_iterator __tmp(*this);
414 this->_M_incr();
415 return __tmp;
416 }
417 };
418
419 // Many of class template _Hashtable's template parameters are policy
420 // classes. These are defaults for the policies.
421
422 /// Default range hashing function: use division to fold a large number
423 /// into the range [0, N).
424 struct _Mod_range_hashing
425 {
426 typedef std::size_t first_argument_type;
427 typedef std::size_t second_argument_type;
428 typedef std::size_t result_type;
429
430 result_type
431 operator()(first_argument_type __num,
432 second_argument_type __den) const noexcept
433 { return __num % __den; }
434 };
435
436 /// Default ranged hash function H. In principle it should be a
437 /// function object composed from objects of type H1 and H2 such that
438 /// h(k, N) = h2(h1(k), N), but that would mean making extra copies of
439 /// h1 and h2. So instead we'll just use a tag to tell class template
440 /// hashtable to do that composition.
441 struct _Default_ranged_hash { };
442
443 /// Default value for rehash policy. Bucket size is (usually) the
444 /// smallest prime that keeps the load factor small enough.
445 struct _Prime_rehash_policy
446 {
447 using __has_load_factor = std::true_type;
448
449 _Prime_rehash_policy(float __z = 1.0) noexcept
450 : _M_max_load_factor(__z), _M_next_resize(0) { }
451
452 float
453 max_load_factor() const noexcept
454 { return _M_max_load_factor; }
455
456 // Return a bucket size no smaller than n.
457 std::size_t
458 _M_next_bkt(std::size_t __n) const;
459
460 // Return a bucket count appropriate for n elements
461 std::size_t
462 _M_bkt_for_elements(std::size_t __n) const
463 { return __builtin_ceil(__n / (long double)_M_max_load_factor); }
464
465 // __n_bkt is current bucket count, __n_elt is current element count,
466 // and __n_ins is number of elements to be inserted. Do we need to
467 // increase bucket count? If so, return make_pair(true, n), where n
468 // is the new bucket count. If not, return make_pair(false, 0).
469 std::pair<bool, std::size_t>
470 _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
471 std::size_t __n_ins) const;
472
473 typedef std::size_t _State;
474
475 _State
476 _M_state() const
477 { return _M_next_resize; }
478
479 void
480 _M_reset() noexcept
481 { _M_next_resize = 0; }
482
483 void
484 _M_reset(_State __state)
485 { _M_next_resize = __state; }
486
487 static const std::size_t _S_growth_factor = 2;
488
489 float _M_max_load_factor;
490 mutable std::size_t _M_next_resize;
491 };
492
493 /// Range hashing function assuming that second arg is a power of 2.
494 struct _Mask_range_hashing
495 {
496 typedef std::size_t first_argument_type;
497 typedef std::size_t second_argument_type;
498 typedef std::size_t result_type;
499
500 result_type
501 operator()(first_argument_type __num,
502 second_argument_type __den) const noexcept
503 { return __num & (__den - 1); }
504 };
505
506 /// Compute closest power of 2 not less than __n
507 inline std::size_t
508 __clp2(std::size_t __n) noexcept
509 {
510 // Equivalent to return __n ? std::ceil2(__n) : 0;
511 if (__n < 2)
512 return __n;
513 const unsigned __lz = sizeof(size_t) > sizeof(long)
514 ? __builtin_clzll(__n - 1ull)
515 : __builtin_clzl(__n - 1ul);
516 // Doing two shifts avoids undefined behaviour when __lz == 0.
517 return (size_t(1) << (numeric_limits<size_t>::digits - __lz - 1)) << 1;
518 }
519
520 /// Rehash policy providing power of 2 bucket numbers. Avoids modulo
521 /// operations.
522 struct _Power2_rehash_policy
523 {
524 using __has_load_factor = std::true_type;
525
526 _Power2_rehash_policy(float __z = 1.0) noexcept
527 : _M_max_load_factor(__z), _M_next_resize(0) { }
528
529 float
530 max_load_factor() const noexcept
531 { return _M_max_load_factor; }
532
533 // Return a bucket size no smaller than n (as long as n is not above the
534 // highest power of 2).
535 std::size_t
536 _M_next_bkt(std::size_t __n) noexcept
537 {
538 const auto __max_width = std::min<size_t>(sizeof(size_t), 8);
539 const auto __max_bkt = size_t(1) << (__max_width * __CHAR_BIT__ - 1);
540 std::size_t __res = __clp2(__n);
541
542 if (__res == __n)
543 __res <<= 1;
544
545 if (__res == 0)
546 __res = __max_bkt;
547
548 if (__res == __max_bkt)
549 // Set next resize to the max value so that we never try to rehash again
550 // as we already reach the biggest possible bucket number.
551 // Note that it might result in max_load_factor not being respected.
552 _M_next_resize = std::size_t(-1);
553 else
554 _M_next_resize
555 = __builtin_ceil(__res * (long double)_M_max_load_factor);
556
557 return __res;
558 }
559
560 // Return a bucket count appropriate for n elements
561 std::size_t
562 _M_bkt_for_elements(std::size_t __n) const noexcept
563 { return __builtin_ceil(__n / (long double)_M_max_load_factor); }
564
565 // __n_bkt is current bucket count, __n_elt is current element count,
566 // and __n_ins is number of elements to be inserted. Do we need to
567 // increase bucket count? If so, return make_pair(true, n), where n
568 // is the new bucket count. If not, return make_pair(false, 0).
569 std::pair<bool, std::size_t>
570 _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
571 std::size_t __n_ins) noexcept
572 {
573 if (__n_elt + __n_ins >= _M_next_resize)
574 {
575 long double __min_bkts = (__n_elt + __n_ins)
576 / (long double)_M_max_load_factor;
577 if (__min_bkts >= __n_bkt)
578 return std::make_pair(true,
579 _M_next_bkt(std::max<std::size_t>(__builtin_floor(__min_bkts) + 1,
580 __n_bkt * _S_growth_factor)));
581
582 _M_next_resize
583 = __builtin_floor(__n_bkt * (long double)_M_max_load_factor);
584 return std::make_pair(false, 0);
585 }
586 else
587 return std::make_pair(false, 0);
588 }
589
590 typedef std::size_t _State;
591
592 _State
593 _M_state() const noexcept
594 { return _M_next_resize; }
595
596 void
597 _M_reset() noexcept
598 { _M_next_resize = 0; }
599
600 void
601 _M_reset(_State __state) noexcept
602 { _M_next_resize = __state; }
603
604 static const std::size_t _S_growth_factor = 2;
605
606 float _M_max_load_factor;
607 std::size_t _M_next_resize;
608 };
609
610 // Base classes for std::_Hashtable. We define these base classes
611 // because in some cases we want to do different things depending on
612 // the value of a policy class. In some cases the policy class
613 // affects which member functions and nested typedefs are defined;
614 // we handle that by specializing base class templates. Several of
615 // the base class templates need to access other members of class
616 // template _Hashtable, so we use a variant of the "Curiously
617 // Recurring Template Pattern" (CRTP) technique.
618
619 /**
620 * Primary class template _Map_base.
621 *
622 * If the hashtable has a value type of the form pair<T1, T2> and a
623 * key extraction policy (_ExtractKey) that returns the first part
624 * of the pair, the hashtable gets a mapped_type typedef. If it
625 * satisfies those criteria and also has unique keys, then it also
626 * gets an operator[].
627 */
628 template<typename _Key, typename _Value, typename _Alloc,
629 typename _ExtractKey, typename _Equal,
630 typename _H1, typename _H2, typename _Hash,
631 typename _RehashPolicy, typename _Traits,
632 bool _Unique_keys = _Traits::__unique_keys::value>
633 struct _Map_base { };
634
635 /// Partial specialization, __unique_keys set to false.
636 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
637 typename _H1, typename _H2, typename _Hash,
638 typename _RehashPolicy, typename _Traits>
639 struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
640 _H1, _H2, _Hash, _RehashPolicy, _Traits, false>
641 {
642 using mapped_type = typename std::tuple_element<1, _Pair>::type;
643 };
644
645 /// Partial specialization, __unique_keys set to true.
646 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
647 typename _H1, typename _H2, typename _Hash,
648 typename _RehashPolicy, typename _Traits>
649 struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
650 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>
651 {
652 private:
653 using __hashtable_base = __detail::_Hashtable_base<_Key, _Pair,
654 _Select1st,
655 _Equal, _H1, _H2, _Hash,
656 _Traits>;
657
658 using __hashtable = _Hashtable<_Key, _Pair, _Alloc,
659 _Select1st, _Equal,
660 _H1, _H2, _Hash, _RehashPolicy, _Traits>;
661
662 using __hash_code = typename __hashtable_base::__hash_code;
663 using __node_type = typename __hashtable_base::__node_type;
664
665 public:
666 using key_type = typename __hashtable_base::key_type;
667 using iterator = typename __hashtable_base::iterator;
668 using mapped_type = typename std::tuple_element<1, _Pair>::type;
669
670 mapped_type&
671 operator[](const key_type& __k);
672
673 mapped_type&
674 operator[](key_type&& __k);
675
676 // _GLIBCXX_RESOLVE_LIB_DEFECTS
677 // DR 761. unordered_map needs an at() member function.
678 mapped_type&
679 at(const key_type& __k);
680
681 const mapped_type&
682 at(const key_type& __k) const;
683 };
684
685 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
686 typename _H1, typename _H2, typename _Hash,
687 typename _RehashPolicy, typename _Traits>
688 auto
689 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
690 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
691 operator[](const key_type& __k)
692 -> mapped_type&
693 {
694 __hashtable* __h = static_cast<__hashtable*>(this);
695 __hash_code __code = __h->_M_hash_code(__k);
696 std::size_t __n = __h->_M_bucket_index(__k, __code);
697 __node_type* __p = __h->_M_find_node(__n, __k, __code);
698
699 if (!__p)
700 {
701 __p = __h->_M_allocate_node(std::piecewise_construct,
702 std::tuple<const key_type&>(__k),
703 std::tuple<>());
704 return __h->_M_insert_unique_node(__n, __code, __p)->second;
705 }
706
707 return __p->_M_v().second;
708 }
709
710 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
711 typename _H1, typename _H2, typename _Hash,
712 typename _RehashPolicy, typename _Traits>
713 auto
714 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
715 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
716 operator[](key_type&& __k)
717 -> mapped_type&
718 {
719 __hashtable* __h = static_cast<__hashtable*>(this);
720 __hash_code __code = __h->_M_hash_code(__k);
721 std::size_t __n = __h->_M_bucket_index(__k, __code);
722 __node_type* __p = __h->_M_find_node(__n, __k, __code);
723
724 if (!__p)
725 {
726 __p = __h->_M_allocate_node(std::piecewise_construct,
727 std::forward_as_tuple(std::move(__k)),
728 std::tuple<>());
729 return __h->_M_insert_unique_node(__n, __code, __p)->second;
730 }
731
732 return __p->_M_v().second;
733 }
734
735 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
736 typename _H1, typename _H2, typename _Hash,
737 typename _RehashPolicy, typename _Traits>
738 auto
739 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
740 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
741 at(const key_type& __k)
742 -> mapped_type&
743 {
744 __hashtable* __h = static_cast<__hashtable*>(this);
745 __hash_code __code = __h->_M_hash_code(__k);
746 std::size_t __n = __h->_M_bucket_index(__k, __code);
747 __node_type* __p = __h->_M_find_node(__n, __k, __code);
748
749 if (!__p)
750 __throw_out_of_range(__N("_Map_base::at"));
751 return __p->_M_v().second;
752 }
753
754 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
755 typename _H1, typename _H2, typename _Hash,
756 typename _RehashPolicy, typename _Traits>
757 auto
758 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
759 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
760 at(const key_type& __k) const
761 -> const mapped_type&
762 {
763 const __hashtable* __h = static_cast<const __hashtable*>(this);
764 __hash_code __code = __h->_M_hash_code(__k);
765 std::size_t __n = __h->_M_bucket_index(__k, __code);
766 __node_type* __p = __h->_M_find_node(__n, __k, __code);
767
768 if (!__p)
769 __throw_out_of_range(__N("_Map_base::at"));
770 return __p->_M_v().second;
771 }
772
773 /**
774 * Primary class template _Insert_base.
775 *
776 * Defines @c insert member functions appropriate to all _Hashtables.
777 */
778 template<typename _Key, typename _Value, typename _Alloc,
779 typename _ExtractKey, typename _Equal,
780 typename _H1, typename _H2, typename _Hash,
781 typename _RehashPolicy, typename _Traits>
782 struct _Insert_base
783 {
784 protected:
785 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
786 _Equal, _H1, _H2, _Hash,
787 _RehashPolicy, _Traits>;
788
789 using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey,
790 _Equal, _H1, _H2, _Hash,
791 _Traits>;
792
793 using value_type = typename __hashtable_base::value_type;
794 using iterator = typename __hashtable_base::iterator;
795 using const_iterator = typename __hashtable_base::const_iterator;
796 using size_type = typename __hashtable_base::size_type;
797
798 using __unique_keys = typename __hashtable_base::__unique_keys;
799 using __ireturn_type = typename __hashtable_base::__ireturn_type;
800 using __node_type = _Hash_node<_Value, _Traits::__hash_cached::value>;
801 using __node_alloc_type = __alloc_rebind<_Alloc, __node_type>;
802 using __node_gen_type = _AllocNode<__node_alloc_type>;
803
804 __hashtable&
805 _M_conjure_hashtable()
806 { return *(static_cast<__hashtable*>(this)); }
807
808 template<typename _InputIterator, typename _NodeGetter>
809 void
810 _M_insert_range(_InputIterator __first, _InputIterator __last,
811 const _NodeGetter&, true_type);
812
813 template<typename _InputIterator, typename _NodeGetter>
814 void
815 _M_insert_range(_InputIterator __first, _InputIterator __last,
816 const _NodeGetter&, false_type);
817
818 public:
819 __ireturn_type
820 insert(const value_type& __v)
821 {
822 __hashtable& __h = _M_conjure_hashtable();
823 __node_gen_type __node_gen(__h);
824 return __h._M_insert(__v, __node_gen, __unique_keys());
825 }
826
827 iterator
828 insert(const_iterator __hint, const value_type& __v)
829 {
830 __hashtable& __h = _M_conjure_hashtable();
831 __node_gen_type __node_gen(__h);
832 return __h._M_insert(__hint, __v, __node_gen, __unique_keys());
833 }
834
835 void
836 insert(initializer_list<value_type> __l)
837 { this->insert(__l.begin(), __l.end()); }
838
839 template<typename _InputIterator>
840 void
841 insert(_InputIterator __first, _InputIterator __last)
842 {
843 __hashtable& __h = _M_conjure_hashtable();
844 __node_gen_type __node_gen(__h);
845 return _M_insert_range(__first, __last, __node_gen, __unique_keys());
846 }
847 };
848
849 template<typename _Key, typename _Value, typename _Alloc,
850 typename _ExtractKey, typename _Equal,
851 typename _H1, typename _H2, typename _Hash,
852 typename _RehashPolicy, typename _Traits>
853 template<typename _InputIterator, typename _NodeGetter>
854 void
855 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
856 _RehashPolicy, _Traits>::
857 _M_insert_range(_InputIterator __first, _InputIterator __last,
858 const _NodeGetter& __node_gen, true_type)
859 {
860 size_type __n_elt = __detail::__distance_fw(__first, __last);
861 if (__n_elt == 0)
862 return;
863
864 __hashtable& __h = _M_conjure_hashtable();
865 for (; __first != __last; ++__first)
866 {
867 if (__h._M_insert(*__first, __node_gen, __unique_keys(),
868 __n_elt).second)
869 __n_elt = 1;
870 else if (__n_elt != 1)
871 --__n_elt;
872 }
873 }
874
875 template<typename _Key, typename _Value, typename _Alloc,
876 typename _ExtractKey, typename _Equal,
877 typename _H1, typename _H2, typename _Hash,
878 typename _RehashPolicy, typename _Traits>
879 template<typename _InputIterator, typename _NodeGetter>
880 void
881 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
882 _RehashPolicy, _Traits>::
883 _M_insert_range(_InputIterator __first, _InputIterator __last,
884 const _NodeGetter& __node_gen, false_type)
885 {
886 using __rehash_type = typename __hashtable::__rehash_type;
887 using __rehash_state = typename __hashtable::__rehash_state;
888 using pair_type = std::pair<bool, std::size_t>;
889
890 size_type __n_elt = __detail::__distance_fw(__first, __last);
891 if (__n_elt == 0)
892 return;
893
894 __hashtable& __h = _M_conjure_hashtable();
895 __rehash_type& __rehash = __h._M_rehash_policy;
896 const __rehash_state& __saved_state = __rehash._M_state();
897 pair_type __do_rehash = __rehash._M_need_rehash(__h._M_bucket_count,
898 __h._M_element_count,
899 __n_elt);
900
901 if (__do_rehash.first)
902 __h._M_rehash(__do_rehash.second, __saved_state);
903
904 for (; __first != __last; ++__first)
905 __h._M_insert(*__first, __node_gen, __unique_keys());
906 }
907
908 /**
909 * Primary class template _Insert.
910 *
911 * Defines @c insert member functions that depend on _Hashtable policies,
912 * via partial specializations.
913 */
914 template<typename _Key, typename _Value, typename _Alloc,
915 typename _ExtractKey, typename _Equal,
916 typename _H1, typename _H2, typename _Hash,
917 typename _RehashPolicy, typename _Traits,
918 bool _Constant_iterators = _Traits::__constant_iterators::value>
919 struct _Insert;
920
921 /// Specialization.
922 template<typename _Key, typename _Value, typename _Alloc,
923 typename _ExtractKey, typename _Equal,
924 typename _H1, typename _H2, typename _Hash,
925 typename _RehashPolicy, typename _Traits>
926 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
927 _RehashPolicy, _Traits, true>
928 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
929 _H1, _H2, _Hash, _RehashPolicy, _Traits>
930 {
931 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
932 _Equal, _H1, _H2, _Hash,
933 _RehashPolicy, _Traits>;
934
935 using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey,
936 _Equal, _H1, _H2, _Hash,
937 _Traits>;
938
939 using value_type = typename __base_type::value_type;
940 using iterator = typename __base_type::iterator;
941 using const_iterator = typename __base_type::const_iterator;
942
943 using __unique_keys = typename __base_type::__unique_keys;
944 using __ireturn_type = typename __hashtable_base::__ireturn_type;
945 using __hashtable = typename __base_type::__hashtable;
946 using __node_gen_type = typename __base_type::__node_gen_type;
947
948 using __base_type::insert;
949
950 __ireturn_type
951 insert(value_type&& __v)
952 {
953 __hashtable& __h = this->_M_conjure_hashtable();
954 __node_gen_type __node_gen(__h);
955 return __h._M_insert(std::move(__v), __node_gen, __unique_keys());
956 }
957
958 iterator
959 insert(const_iterator __hint, value_type&& __v)
960 {
961 __hashtable& __h = this->_M_conjure_hashtable();
962 __node_gen_type __node_gen(__h);
963 return __h._M_insert(__hint, std::move(__v), __node_gen,
964 __unique_keys());
965 }
966 };
967
968 /// Specialization.
969 template<typename _Key, typename _Value, typename _Alloc,
970 typename _ExtractKey, typename _Equal,
971 typename _H1, typename _H2, typename _Hash,
972 typename _RehashPolicy, typename _Traits>
973 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
974 _RehashPolicy, _Traits, false>
975 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
976 _H1, _H2, _Hash, _RehashPolicy, _Traits>
977 {
978 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
979 _Equal, _H1, _H2, _Hash,
980 _RehashPolicy, _Traits>;
981 using value_type = typename __base_type::value_type;
982 using iterator = typename __base_type::iterator;
983 using const_iterator = typename __base_type::const_iterator;
984
985 using __unique_keys = typename __base_type::__unique_keys;
986 using __hashtable = typename __base_type::__hashtable;
987 using __ireturn_type = typename __base_type::__ireturn_type;
988
989 using __base_type::insert;
990
991 template<typename _Pair>
992 using __is_cons = std::is_constructible<value_type, _Pair&&>;
993
994 template<typename _Pair>
995 using _IFcons = std::enable_if<__is_cons<_Pair>::value>;
996
997 template<typename _Pair>
998 using _IFconsp = typename _IFcons<_Pair>::type;
999
1000 template<typename _Pair, typename = _IFconsp<_Pair>>
1001 __ireturn_type
1002 insert(_Pair&& __v)
1003 {
1004 __hashtable& __h = this->_M_conjure_hashtable();
1005 return __h._M_emplace(__unique_keys(), std::forward<_Pair>(__v));
1006 }
1007
1008 template<typename _Pair, typename = _IFconsp<_Pair>>
1009 iterator
1010 insert(const_iterator __hint, _Pair&& __v)
1011 {
1012 __hashtable& __h = this->_M_conjure_hashtable();
1013 return __h._M_emplace(__hint, __unique_keys(),
1014 std::forward<_Pair>(__v));
1015 }
1016 };
1017
1018 template<typename _Policy>
1019 using __has_load_factor = typename _Policy::__has_load_factor;
1020
1021 /**
1022 * Primary class template _Rehash_base.
1023 *
1024 * Give hashtable the max_load_factor functions and reserve iff the
1025 * rehash policy supports it.
1026 */
1027 template<typename _Key, typename _Value, typename _Alloc,
1028 typename _ExtractKey, typename _Equal,
1029 typename _H1, typename _H2, typename _Hash,
1030 typename _RehashPolicy, typename _Traits,
1031 typename =
1032 __detected_or_t<std::false_type, __has_load_factor, _RehashPolicy>>
1033 struct _Rehash_base;
1034
1035 /// Specialization when rehash policy doesn't provide load factor management.
1036 template<typename _Key, typename _Value, typename _Alloc,
1037 typename _ExtractKey, typename _Equal,
1038 typename _H1, typename _H2, typename _Hash,
1039 typename _RehashPolicy, typename _Traits>
1040 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1041 _H1, _H2, _Hash, _RehashPolicy, _Traits,
1042 std::false_type>
1043 {
1044 };
1045
1046 /// Specialization when rehash policy provide load factor management.
1047 template<typename _Key, typename _Value, typename _Alloc,
1048 typename _ExtractKey, typename _Equal,
1049 typename _H1, typename _H2, typename _Hash,
1050 typename _RehashPolicy, typename _Traits>
1051 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1052 _H1, _H2, _Hash, _RehashPolicy, _Traits,
1053 std::true_type>
1054 {
1055 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
1056 _Equal, _H1, _H2, _Hash,
1057 _RehashPolicy, _Traits>;
1058
1059 float
1060 max_load_factor() const noexcept
1061 {
1062 const __hashtable* __this = static_cast<const __hashtable*>(this);
1063 return __this->__rehash_policy().max_load_factor();
1064 }
1065
1066 void
1067 max_load_factor(float __z)
1068 {
1069 __hashtable* __this = static_cast<__hashtable*>(this);
1070 __this->__rehash_policy(_RehashPolicy(__z));
1071 }
1072
1073 void
1074 reserve(std::size_t __n)
1075 {
1076 __hashtable* __this = static_cast<__hashtable*>(this);
1077 __this->rehash(__builtin_ceil(__n / max_load_factor()));
1078 }
1079 };
1080
1081 /**
1082 * Primary class template _Hashtable_ebo_helper.
1083 *
1084 * Helper class using EBO when it is not forbidden (the type is not
1085 * final) and when it is worth it (the type is empty.)
1086 */
1087 template<int _Nm, typename _Tp,
1088 bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)>
1089 struct _Hashtable_ebo_helper;
1090
1091 /// Specialization using EBO.
1092 template<int _Nm, typename _Tp>
1093 struct _Hashtable_ebo_helper<_Nm, _Tp, true>
1094 : private _Tp
1095 {
1096 _Hashtable_ebo_helper() = default;
1097
1098 template<typename _OtherTp>
1099 _Hashtable_ebo_helper(_OtherTp&& __tp)
1100 : _Tp(std::forward<_OtherTp>(__tp))
1101 { }
1102
1103 static const _Tp&
1104 _S_cget(const _Hashtable_ebo_helper& __eboh)
1105 { return static_cast<const _Tp&>(__eboh); }
1106
1107 static _Tp&
1108 _S_get(_Hashtable_ebo_helper& __eboh)
1109 { return static_cast<_Tp&>(__eboh); }
1110 };
1111
1112 /// Specialization not using EBO.
1113 template<int _Nm, typename _Tp>
1114 struct _Hashtable_ebo_helper<_Nm, _Tp, false>
1115 {
1116 _Hashtable_ebo_helper() = default;
1117
1118 template<typename _OtherTp>
1119 _Hashtable_ebo_helper(_OtherTp&& __tp)
1120 : _M_tp(std::forward<_OtherTp>(__tp))
1121 { }
1122
1123 static const _Tp&
1124 _S_cget(const _Hashtable_ebo_helper& __eboh)
1125 { return __eboh._M_tp; }
1126
1127 static _Tp&
1128 _S_get(_Hashtable_ebo_helper& __eboh)
1129 { return __eboh._M_tp; }
1130
1131 private:
1132 _Tp _M_tp;
1133 };
1134
1135 /**
1136 * Primary class template _Local_iterator_base.
1137 *
1138 * Base class for local iterators, used to iterate within a bucket
1139 * but not between buckets.
1140 */
1141 template<typename _Key, typename _Value, typename _ExtractKey,
1142 typename _H1, typename _H2, typename _Hash,
1143 bool __cache_hash_code>
1144 struct _Local_iterator_base;
1145
1146 /**
1147 * Primary class template _Hash_code_base.
1148 *
1149 * Encapsulates two policy issues that aren't quite orthogonal.
1150 * (1) the difference between using a ranged hash function and using
1151 * the combination of a hash function and a range-hashing function.
1152 * In the former case we don't have such things as hash codes, so
1153 * we have a dummy type as placeholder.
1154 * (2) Whether or not we cache hash codes. Caching hash codes is
1155 * meaningless if we have a ranged hash function.
1156 *
1157 * We also put the key extraction objects here, for convenience.
1158 * Each specialization derives from one or more of the template
1159 * parameters to benefit from Ebo. This is important as this type
1160 * is inherited in some cases by the _Local_iterator_base type used
1161 * to implement local_iterator and const_local_iterator. As with
1162 * any iterator type we prefer to make it as small as possible.
1163 *
1164 * Primary template is unused except as a hook for specializations.
1165 */
1166 template<typename _Key, typename _Value, typename _ExtractKey,
1167 typename _H1, typename _H2, typename _Hash,
1168 bool __cache_hash_code>
1169 struct _Hash_code_base;
1170
1171 /// Specialization: ranged hash function, no caching hash codes. H1
1172 /// and H2 are provided but ignored. We define a dummy hash code type.
1173 template<typename _Key, typename _Value, typename _ExtractKey,
1174 typename _H1, typename _H2, typename _Hash>
1175 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>
1176 : private _Hashtable_ebo_helper<0, _ExtractKey>,
1177 private _Hashtable_ebo_helper<1, _Hash>
1178 {
1179 private:
1180 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
1181 using __ebo_hash = _Hashtable_ebo_helper<1, _Hash>;
1182
1183 protected:
1184 typedef void* __hash_code;
1185 typedef _Hash_node<_Value, false> __node_type;
1186
1187 // We need the default constructor for the local iterators and _Hashtable
1188 // default constructor.
1189 _Hash_code_base() = default;
1190
1191 _Hash_code_base(const _ExtractKey& __ex, const _H1&, const _H2&,
1192 const _Hash& __h)
1193 : __ebo_extract_key(__ex), __ebo_hash(__h) { }
1194
1195 __hash_code
1196 _M_hash_code(const _Key& __key) const
1197 { return 0; }
1198
1199 std::size_t
1200 _M_bucket_index(const _Key& __k, __hash_code, std::size_t __n) const
1201 { return _M_ranged_hash()(__k, __n); }
1202
1203 std::size_t
1204 _M_bucket_index(const __node_type* __p, std::size_t __n) const
1205 noexcept( noexcept(declval<const _Hash&>()(declval<const _Key&>(),
1206 (std::size_t)0)) )
1207 { return _M_ranged_hash()(_M_extract()(__p->_M_v()), __n); }
1208
1209 void
1210 _M_store_code(__node_type*, __hash_code) const
1211 { }
1212
1213 void
1214 _M_copy_code(__node_type*, const __node_type*) const
1215 { }
1216
1217 void
1218 _M_swap(_Hash_code_base& __x)
1219 {
1220 std::swap(_M_extract(), __x._M_extract());
1221 std::swap(_M_ranged_hash(), __x._M_ranged_hash());
1222 }
1223
1224 const _ExtractKey&
1225 _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
1226
1227 _ExtractKey&
1228 _M_extract() { return __ebo_extract_key::_S_get(*this); }
1229
1230 const _Hash&
1231 _M_ranged_hash() const { return __ebo_hash::_S_cget(*this); }
1232
1233 _Hash&
1234 _M_ranged_hash() { return __ebo_hash::_S_get(*this); }
1235 };
1236
1237 // No specialization for ranged hash function while caching hash codes.
1238 // That combination is meaningless, and trying to do it is an error.
1239
1240 /// Specialization: ranged hash function, cache hash codes. This
1241 /// combination is meaningless, so we provide only a declaration
1242 /// and no definition.
1243 template<typename _Key, typename _Value, typename _ExtractKey,
1244 typename _H1, typename _H2, typename _Hash>
1245 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>;
1246
1247 /// Specialization: hash function and range-hashing function, no
1248 /// caching of hash codes.
1249 /// Provides typedef and accessor required by C++ 11.
1250 template<typename _Key, typename _Value, typename _ExtractKey,
1251 typename _H1, typename _H2>
1252 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
1253 _Default_ranged_hash, false>
1254 : private _Hashtable_ebo_helper<0, _ExtractKey>,
1255 private _Hashtable_ebo_helper<1, _H1>,
1256 private _Hashtable_ebo_helper<2, _H2>
1257 {
1258 private:
1259 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
1260 using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>;
1261 using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>;
1262
1263 // Gives the local iterator implementation access to _M_bucket_index().
1264 friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2,
1265 _Default_ranged_hash, false>;
1266
1267 public:
1268 typedef _H1 hasher;
1269
1270 hasher
1271 hash_function() const
1272 { return _M_h1(); }
1273
1274 protected:
1275 typedef std::size_t __hash_code;
1276 typedef _Hash_node<_Value, false> __node_type;
1277
1278 // We need the default constructor for the local iterators and _Hashtable
1279 // default constructor.
1280 _Hash_code_base() = default;
1281
1282 _Hash_code_base(const _ExtractKey& __ex,
1283 const _H1& __h1, const _H2& __h2,
1284 const _Default_ranged_hash&)
1285 : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { }
1286
1287 __hash_code
1288 _M_hash_code(const _Key& __k) const
1289 {
1290 static_assert(__is_invocable<const _H1&, const _Key&>{},
1291 "hash function must be invocable with an argument of key type");
1292 return _M_h1()(__k);
1293 }
1294
1295 std::size_t
1296 _M_bucket_index(const _Key&, __hash_code __c, std::size_t __n) const
1297 { return _M_h2()(__c, __n); }
1298
1299 std::size_t
1300 _M_bucket_index(const __node_type* __p, std::size_t __n) const
1301 noexcept( noexcept(declval<const _H1&>()(declval<const _Key&>()))
1302 && noexcept(declval<const _H2&>()((__hash_code)0,
1303 (std::size_t)0)) )
1304 { return _M_h2()(_M_h1()(_M_extract()(__p->_M_v())), __n); }
1305
1306 void
1307 _M_store_code(__node_type*, __hash_code) const
1308 { }
1309
1310 void
1311 _M_copy_code(__node_type*, const __node_type*) const
1312 { }
1313
1314 void
1315 _M_swap(_Hash_code_base& __x)
1316 {
1317 std::swap(_M_extract(), __x._M_extract());
1318 std::swap(_M_h1(), __x._M_h1());
1319 std::swap(_M_h2(), __x._M_h2());
1320 }
1321
1322 const _ExtractKey&
1323 _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
1324
1325 _ExtractKey&
1326 _M_extract() { return __ebo_extract_key::_S_get(*this); }
1327
1328 const _H1&
1329 _M_h1() const { return __ebo_h1::_S_cget(*this); }
1330
1331 _H1&
1332 _M_h1() { return __ebo_h1::_S_get(*this); }
1333
1334 const _H2&
1335 _M_h2() const { return __ebo_h2::_S_cget(*this); }
1336
1337 _H2&
1338 _M_h2() { return __ebo_h2::_S_get(*this); }
1339 };
1340
1341 /// Specialization: hash function and range-hashing function,
1342 /// caching hash codes. H is provided but ignored. Provides
1343 /// typedef and accessor required by C++ 11.
1344 template<typename _Key, typename _Value, typename _ExtractKey,
1345 typename _H1, typename _H2>
1346 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
1347 _Default_ranged_hash, true>
1348 : private _Hashtable_ebo_helper<0, _ExtractKey>,
1349 private _Hashtable_ebo_helper<1, _H1>,
1350 private _Hashtable_ebo_helper<2, _H2>
1351 {
1352 private:
1353 // Gives the local iterator implementation access to _M_h2().
1354 friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2,
1355 _Default_ranged_hash, true>;
1356
1357 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
1358 using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>;
1359 using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>;
1360
1361 public:
1362 typedef _H1 hasher;
1363
1364 hasher
1365 hash_function() const
1366 { return _M_h1(); }
1367
1368 protected:
1369 typedef std::size_t __hash_code;
1370 typedef _Hash_node<_Value, true> __node_type;
1371
1372 // We need the default constructor for _Hashtable default constructor.
1373 _Hash_code_base() = default;
1374 _Hash_code_base(const _ExtractKey& __ex,
1375 const _H1& __h1, const _H2& __h2,
1376 const _Default_ranged_hash&)
1377 : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { }
1378
1379 __hash_code
1380 _M_hash_code(const _Key& __k) const
1381 {
1382 static_assert(__is_invocable<const _H1&, const _Key&>{},
1383 "hash function must be invocable with an argument of key type");
1384 return _M_h1()(__k);
1385 }
1386
1387 std::size_t
1388 _M_bucket_index(const _Key&, __hash_code __c,
1389 std::size_t __n) const
1390 { return _M_h2()(__c, __n); }
1391
1392 std::size_t
1393 _M_bucket_index(const __node_type* __p, std::size_t __n) const
1394 noexcept( noexcept(declval<const _H2&>()((__hash_code)0,
1395 (std::size_t)0)) )
1396 { return _M_h2()(__p->_M_hash_code, __n); }
1397
1398 void
1399 _M_store_code(__node_type* __n, __hash_code __c) const
1400 { __n->_M_hash_code = __c; }
1401
1402 void
1403 _M_copy_code(__node_type* __to, const __node_type* __from) const
1404 { __to->_M_hash_code = __from->_M_hash_code; }
1405
1406 void
1407 _M_swap(_Hash_code_base& __x)
1408 {
1409 std::swap(_M_extract(), __x._M_extract());
1410 std::swap(_M_h1(), __x._M_h1());
1411 std::swap(_M_h2(), __x._M_h2());
1412 }
1413
1414 const _ExtractKey&
1415 _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
1416
1417 _ExtractKey&
1418 _M_extract() { return __ebo_extract_key::_S_get(*this); }
1419
1420 const _H1&
1421 _M_h1() const { return __ebo_h1::_S_cget(*this); }
1422
1423 _H1&
1424 _M_h1() { return __ebo_h1::_S_get(*this); }
1425
1426 const _H2&
1427 _M_h2() const { return __ebo_h2::_S_cget(*this); }
1428
1429 _H2&
1430 _M_h2() { return __ebo_h2::_S_get(*this); }
1431 };
1432
1433 /**
1434 * Primary class template _Equal_helper.
1435 *
1436 */
1437 template <typename _Key, typename _Value, typename _ExtractKey,
1438 typename _Equal, typename _HashCodeType,
1439 bool __cache_hash_code>
1440 struct _Equal_helper;
1441
1442 /// Specialization.
1443 template<typename _Key, typename _Value, typename _ExtractKey,
1444 typename _Equal, typename _HashCodeType>
1445 struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, true>
1446 {
1447 static bool
1448 _S_equals(const _Equal& __eq, const _ExtractKey& __extract,
1449 const _Key& __k, _HashCodeType __c, _Hash_node<_Value, true>* __n)
1450 { return __c == __n->_M_hash_code && __eq(__k, __extract(__n->_M_v())); }
1451 };
1452
1453 /// Specialization.
1454 template<typename _Key, typename _Value, typename _ExtractKey,
1455 typename _Equal, typename _HashCodeType>
1456 struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, false>
1457 {
1458 static bool
1459 _S_equals(const _Equal& __eq, const _ExtractKey& __extract,
1460 const _Key& __k, _HashCodeType, _Hash_node<_Value, false>* __n)
1461 { return __eq(__k, __extract(__n->_M_v())); }
1462 };
1463
1464
1465 /// Partial specialization used when nodes contain a cached hash code.
1466 template<typename _Key, typename _Value, typename _ExtractKey,
1467 typename _H1, typename _H2, typename _Hash>
1468 struct _Local_iterator_base<_Key, _Value, _ExtractKey,
1469 _H1, _H2, _Hash, true>
1470 : private _Hashtable_ebo_helper<0, _H2>
1471 {
1472 protected:
1473 using __base_type = _Hashtable_ebo_helper<0, _H2>;
1474 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
1475 _H1, _H2, _Hash, true>;
1476
1477 _Local_iterator_base() = default;
1478 _Local_iterator_base(const __hash_code_base& __base,
1479 _Hash_node<_Value, true>* __p,
1480 std::size_t __bkt, std::size_t __bkt_count)
1481 : __base_type(__base._M_h2()),
1482 _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { }
1483
1484 void
1485 _M_incr()
1486 {
1487 _M_cur = _M_cur->_M_next();
1488 if (_M_cur)
1489 {
1490 std::size_t __bkt
1491 = __base_type::_S_get(*this)(_M_cur->_M_hash_code,
1492 _M_bucket_count);
1493 if (__bkt != _M_bucket)
1494 _M_cur = nullptr;
1495 }
1496 }
1497
1498 _Hash_node<_Value, true>* _M_cur;
1499 std::size_t _M_bucket;
1500 std::size_t _M_bucket_count;
1501
1502 public:
1503 const void*
1504 _M_curr() const { return _M_cur; } // for equality ops
1505
1506 std::size_t
1507 _M_get_bucket() const { return _M_bucket; } // for debug mode
1508 };
1509
1510 // Uninitialized storage for a _Hash_code_base.
1511 // This type is DefaultConstructible and Assignable even if the
1512 // _Hash_code_base type isn't, so that _Local_iterator_base<..., false>
1513 // can be DefaultConstructible and Assignable.
1514 template<typename _Tp, bool _IsEmpty = std::is_empty<_Tp>::value>
1515 struct _Hash_code_storage
1516 {
1517 __gnu_cxx::__aligned_buffer<_Tp> _M_storage;
1518
1519 _Tp*
1520 _M_h() { return _M_storage._M_ptr(); }
1521
1522 const _Tp*
1523 _M_h() const { return _M_storage._M_ptr(); }
1524 };
1525
1526 // Empty partial specialization for empty _Hash_code_base types.
1527 template<typename _Tp>
1528 struct _Hash_code_storage<_Tp, true>
1529 {
1530 static_assert( std::is_empty<_Tp>::value, "Type must be empty" );
1531
1532 // As _Tp is an empty type there will be no bytes written/read through
1533 // the cast pointer, so no strict-aliasing violation.
1534 _Tp*
1535 _M_h() { return reinterpret_cast<_Tp*>(this); }
1536
1537 const _Tp*
1538 _M_h() const { return reinterpret_cast<const _Tp*>(this); }
1539 };
1540
1541 template<typename _Key, typename _Value, typename _ExtractKey,
1542 typename _H1, typename _H2, typename _Hash>
1543 using __hash_code_for_local_iter
1544 = _Hash_code_storage<_Hash_code_base<_Key, _Value, _ExtractKey,
1545 _H1, _H2, _Hash, false>>;
1546
1547 // Partial specialization used when hash codes are not cached
1548 template<typename _Key, typename _Value, typename _ExtractKey,
1549 typename _H1, typename _H2, typename _Hash>
1550 struct _Local_iterator_base<_Key, _Value, _ExtractKey,
1551 _H1, _H2, _Hash, false>
1552 : __hash_code_for_local_iter<_Key, _Value, _ExtractKey, _H1, _H2, _Hash>
1553 {
1554 protected:
1555 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
1556 _H1, _H2, _Hash, false>;
1557
1558 _Local_iterator_base() : _M_bucket_count(-1) { }
1559
1560 _Local_iterator_base(const __hash_code_base& __base,
1561 _Hash_node<_Value, false>* __p,
1562 std::size_t __bkt, std::size_t __bkt_count)
1563 : _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count)
1564 { _M_init(__base); }
1565
1566 ~_Local_iterator_base()
1567 {
1568 if (_M_bucket_count != -1)
1569 _M_destroy();
1570 }
1571
1572 _Local_iterator_base(const _Local_iterator_base& __iter)
1573 : _M_cur(__iter._M_cur), _M_bucket(__iter._M_bucket),
1574 _M_bucket_count(__iter._M_bucket_count)
1575 {
1576 if (_M_bucket_count != -1)
1577 _M_init(*__iter._M_h());
1578 }
1579
1580 _Local_iterator_base&
1581 operator=(const _Local_iterator_base& __iter)
1582 {
1583 if (_M_bucket_count != -1)
1584 _M_destroy();
1585 _M_cur = __iter._M_cur;
1586 _M_bucket = __iter._M_bucket;
1587 _M_bucket_count = __iter._M_bucket_count;
1588 if (_M_bucket_count != -1)
1589 _M_init(*__iter._M_h());
1590 return *this;
1591 }
1592
1593 void
1594 _M_incr()
1595 {
1596 _M_cur = _M_cur->_M_next();
1597 if (_M_cur)
1598 {
1599 std::size_t __bkt = this->_M_h()->_M_bucket_index(_M_cur,
1600 _M_bucket_count);
1601 if (__bkt != _M_bucket)
1602 _M_cur = nullptr;
1603 }
1604 }
1605
1606 _Hash_node<_Value, false>* _M_cur;
1607 std::size_t _M_bucket;
1608 std::size_t _M_bucket_count;
1609
1610 void
1611 _M_init(const __hash_code_base& __base)
1612 { ::new(this->_M_h()) __hash_code_base(__base); }
1613
1614 void
1615 _M_destroy() { this->_M_h()->~__hash_code_base(); }
1616
1617 public:
1618 const void*
1619 _M_curr() const { return _M_cur; } // for equality ops and debug mode
1620
1621 std::size_t
1622 _M_get_bucket() const { return _M_bucket; } // for debug mode
1623 };
1624
1625 template<typename _Key, typename _Value, typename _ExtractKey,
1626 typename _H1, typename _H2, typename _Hash, bool __cache>
1627 inline bool
1628 operator==(const _Local_iterator_base<_Key, _Value, _ExtractKey,
1629 _H1, _H2, _Hash, __cache>& __x,
1630 const _Local_iterator_base<_Key, _Value, _ExtractKey,
1631 _H1, _H2, _Hash, __cache>& __y)
1632 { return __x._M_curr() == __y._M_curr(); }
1633
1634 template<typename _Key, typename _Value, typename _ExtractKey,
1635 typename _H1, typename _H2, typename _Hash, bool __cache>
1636 inline bool
1637 operator!=(const _Local_iterator_base<_Key, _Value, _ExtractKey,
1638 _H1, _H2, _Hash, __cache>& __x,
1639 const _Local_iterator_base<_Key, _Value, _ExtractKey,
1640 _H1, _H2, _Hash, __cache>& __y)
1641 { return __x._M_curr() != __y._M_curr(); }
1642
1643 /// local iterators
1644 template<typename _Key, typename _Value, typename _ExtractKey,
1645 typename _H1, typename _H2, typename _Hash,
1646 bool __constant_iterators, bool __cache>
1647 struct _Local_iterator
1648 : public _Local_iterator_base<_Key, _Value, _ExtractKey,
1649 _H1, _H2, _Hash, __cache>
1650 {
1651 private:
1652 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey,
1653 _H1, _H2, _Hash, __cache>;
1654 using __hash_code_base = typename __base_type::__hash_code_base;
1655 public:
1656 typedef _Value value_type;
1657 typedef typename std::conditional<__constant_iterators,
1658 const _Value*, _Value*>::type
1659 pointer;
1660 typedef typename std::conditional<__constant_iterators,
1661 const _Value&, _Value&>::type
1662 reference;
1663 typedef std::ptrdiff_t difference_type;
1664 typedef std::forward_iterator_tag iterator_category;
1665
1666 _Local_iterator() = default;
1667
1668 _Local_iterator(const __hash_code_base& __base,
1669 _Hash_node<_Value, __cache>* __p,
1670 std::size_t __bkt, std::size_t __bkt_count)
1671 : __base_type(__base, __p, __bkt, __bkt_count)
1672 { }
1673
1674 reference
1675 operator*() const
1676 { return this->_M_cur->_M_v(); }
1677
1678 pointer
1679 operator->() const
1680 { return this->_M_cur->_M_valptr(); }
1681
1682 _Local_iterator&
1683 operator++()
1684 {
1685 this->_M_incr();
1686 return *this;
1687 }
1688
1689 _Local_iterator
1690 operator++(int)
1691 {
1692 _Local_iterator __tmp(*this);
1693 this->_M_incr();
1694 return __tmp;
1695 }
1696 };
1697
1698 /// local const_iterators
1699 template<typename _Key, typename _Value, typename _ExtractKey,
1700 typename _H1, typename _H2, typename _Hash,
1701 bool __constant_iterators, bool __cache>
1702 struct _Local_const_iterator
1703 : public _Local_iterator_base<_Key, _Value, _ExtractKey,
1704 _H1, _H2, _Hash, __cache>
1705 {
1706 private:
1707 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey,
1708 _H1, _H2, _Hash, __cache>;
1709 using __hash_code_base = typename __base_type::__hash_code_base;
1710
1711 public:
1712 typedef _Value value_type;
1713 typedef const _Value* pointer;
1714 typedef const _Value& reference;
1715 typedef std::ptrdiff_t difference_type;
1716 typedef std::forward_iterator_tag iterator_category;
1717
1718 _Local_const_iterator() = default;
1719
1720 _Local_const_iterator(const __hash_code_base& __base,
1721 _Hash_node<_Value, __cache>* __p,
1722 std::size_t __bkt, std::size_t __bkt_count)
1723 : __base_type(__base, __p, __bkt, __bkt_count)
1724 { }
1725
1726 _Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey,
1727 _H1, _H2, _Hash,
1728 __constant_iterators,
1729 __cache>& __x)
1730 : __base_type(__x)
1731 { }
1732
1733 reference
1734 operator*() const
1735 { return this->_M_cur->_M_v(); }
1736
1737 pointer
1738 operator->() const
1739 { return this->_M_cur->_M_valptr(); }
1740
1741 _Local_const_iterator&
1742 operator++()
1743 {
1744 this->_M_incr();
1745 return *this;
1746 }
1747
1748 _Local_const_iterator
1749 operator++(int)
1750 {
1751 _Local_const_iterator __tmp(*this);
1752 this->_M_incr();
1753 return __tmp;
1754 }
1755 };
1756
1757 /**
1758 * Primary class template _Hashtable_base.
1759 *
1760 * Helper class adding management of _Equal functor to
1761 * _Hash_code_base type.
1762 *
1763 * Base class templates are:
1764 * - __detail::_Hash_code_base
1765 * - __detail::_Hashtable_ebo_helper
1766 */
1767 template<typename _Key, typename _Value,
1768 typename _ExtractKey, typename _Equal,
1769 typename _H1, typename _H2, typename _Hash, typename _Traits>
1770 struct _Hashtable_base
1771 : public _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash,
1772 _Traits::__hash_cached::value>,
1773 private _Hashtable_ebo_helper<0, _Equal>
1774 {
1775 public:
1776 typedef _Key key_type;
1777 typedef _Value value_type;
1778 typedef _Equal key_equal;
1779 typedef std::size_t size_type;
1780 typedef std::ptrdiff_t difference_type;
1781
1782 using __traits_type = _Traits;
1783 using __hash_cached = typename __traits_type::__hash_cached;
1784 using __constant_iterators = typename __traits_type::__constant_iterators;
1785 using __unique_keys = typename __traits_type::__unique_keys;
1786
1787 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
1788 _H1, _H2, _Hash,
1789 __hash_cached::value>;
1790
1791 using __hash_code = typename __hash_code_base::__hash_code;
1792 using __node_type = typename __hash_code_base::__node_type;
1793
1794 using iterator = __detail::_Node_iterator<value_type,
1795 __constant_iterators::value,
1796 __hash_cached::value>;
1797
1798 using const_iterator = __detail::_Node_const_iterator<value_type,
1799 __constant_iterators::value,
1800 __hash_cached::value>;
1801
1802 using local_iterator = __detail::_Local_iterator<key_type, value_type,
1803 _ExtractKey, _H1, _H2, _Hash,
1804 __constant_iterators::value,
1805 __hash_cached::value>;
1806
1807 using const_local_iterator = __detail::_Local_const_iterator<key_type,
1808 value_type,
1809 _ExtractKey, _H1, _H2, _Hash,
1810 __constant_iterators::value,
1811 __hash_cached::value>;
1812
1813 using __ireturn_type = typename std::conditional<__unique_keys::value,
1814 std::pair<iterator, bool>,
1815 iterator>::type;
1816 private:
1817 using _EqualEBO = _Hashtable_ebo_helper<0, _Equal>;
1818 using _EqualHelper = _Equal_helper<_Key, _Value, _ExtractKey, _Equal,
1819 __hash_code, __hash_cached::value>;
1820
1821 protected:
1822 _Hashtable_base() = default;
1823 _Hashtable_base(const _ExtractKey& __ex, const _H1& __h1, const _H2& __h2,
1824 const _Hash& __hash, const _Equal& __eq)
1825 : __hash_code_base(__ex, __h1, __h2, __hash), _EqualEBO(__eq)
1826 { }
1827
1828 bool
1829 _M_equals(const _Key& __k, __hash_code __c, __node_type* __n) const
1830 {
1831 static_assert(__is_invocable<const _Equal&, const _Key&, const _Key&>{},
1832 "key equality predicate must be invocable with two arguments of "
1833 "key type");
1834 return _EqualHelper::_S_equals(_M_eq(), this->_M_extract(),
1835 __k, __c, __n);
1836 }
1837
1838 void
1839 _M_swap(_Hashtable_base& __x)
1840 {
1841 __hash_code_base::_M_swap(__x);
1842 std::swap(_M_eq(), __x._M_eq());
1843 }
1844
1845 const _Equal&
1846 _M_eq() const { return _EqualEBO::_S_cget(*this); }
1847
1848 _Equal&
1849 _M_eq() { return _EqualEBO::_S_get(*this); }
1850 };
1851
1852 /**
1853 * struct _Equality_base.
1854 *
1855 * Common types and functions for class _Equality.
1856 */
1857 struct _Equality_base
1858 {
1859 protected:
1860 template<typename _Uiterator>
1861 static bool
1862 _S_is_permutation(_Uiterator, _Uiterator, _Uiterator);
1863 };
1864
1865 // See std::is_permutation in N3068.
1866 template<typename _Uiterator>
1867 bool
1868 _Equality_base::
1869 _S_is_permutation(_Uiterator __first1, _Uiterator __last1,
1870 _Uiterator __first2)
1871 {
1872 for (; __first1 != __last1; ++__first1, ++__first2)
1873 if (!(*__first1 == *__first2))
1874 break;
1875
1876 if (__first1 == __last1)
1877 return true;
1878
1879 _Uiterator __last2 = __first2;
1880 std::advance(__last2, std::distance(__first1, __last1));
1881
1882 for (_Uiterator __it1 = __first1; __it1 != __last1; ++__it1)
1883 {
1884 _Uiterator __tmp = __first1;
1885 while (__tmp != __it1 && !bool(*__tmp == *__it1))
1886 ++__tmp;
1887
1888 // We've seen this one before.
1889 if (__tmp != __it1)
1890 continue;
1891
1892 std::ptrdiff_t __n2 = 0;
1893 for (__tmp = __first2; __tmp != __last2; ++__tmp)
1894 if (*__tmp == *__it1)
1895 ++__n2;
1896
1897 if (!__n2)
1898 return false;
1899
1900 std::ptrdiff_t __n1 = 0;
1901 for (__tmp = __it1; __tmp != __last1; ++__tmp)
1902 if (*__tmp == *__it1)
1903 ++__n1;
1904
1905 if (__n1 != __n2)
1906 return false;
1907 }
1908 return true;
1909 }
1910
1911 /**
1912 * Primary class template _Equality.
1913 *
1914 * This is for implementing equality comparison for unordered
1915 * containers, per N3068, by John Lakos and Pablo Halpern.
1916 * Algorithmically, we follow closely the reference implementations
1917 * therein.
1918 */
1919 template<typename _Key, typename _Value, typename _Alloc,
1920 typename _ExtractKey, typename _Equal,
1921 typename _H1, typename _H2, typename _Hash,
1922 typename _RehashPolicy, typename _Traits,
1923 bool _Unique_keys = _Traits::__unique_keys::value>
1924 struct _Equality;
1925
1926 /// Specialization.
1927 template<typename _Key, typename _Value, typename _Alloc,
1928 typename _ExtractKey, typename _Equal,
1929 typename _H1, typename _H2, typename _Hash,
1930 typename _RehashPolicy, typename _Traits>
1931 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1932 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>
1933 {
1934 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1935 _H1, _H2, _Hash, _RehashPolicy, _Traits>;
1936
1937 bool
1938 _M_equal(const __hashtable&) const;
1939 };
1940
1941 template<typename _Key, typename _Value, typename _Alloc,
1942 typename _ExtractKey, typename _Equal,
1943 typename _H1, typename _H2, typename _Hash,
1944 typename _RehashPolicy, typename _Traits>
1945 bool
1946 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1947 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
1948 _M_equal(const __hashtable& __other) const
1949 {
1950 const __hashtable* __this = static_cast<const __hashtable*>(this);
1951
1952 if (__this->size() != __other.size())
1953 return false;
1954
1955 for (auto __itx = __this->begin(); __itx != __this->end(); ++__itx)
1956 {
1957 const auto __ity = __other.find(_ExtractKey()(*__itx));
1958 if (__ity == __other.end() || !bool(*__ity == *__itx))
1959 return false;
1960 }
1961 return true;
1962 }
1963
1964 /// Specialization.
1965 template<typename _Key, typename _Value, typename _Alloc,
1966 typename _ExtractKey, typename _Equal,
1967 typename _H1, typename _H2, typename _Hash,
1968 typename _RehashPolicy, typename _Traits>
1969 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1970 _H1, _H2, _Hash, _RehashPolicy, _Traits, false>
1971 : public _Equality_base
1972 {
1973 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1974 _H1, _H2, _Hash, _RehashPolicy, _Traits>;
1975
1976 bool
1977 _M_equal(const __hashtable&) const;
1978 };
1979
1980 template<typename _Key, typename _Value, typename _Alloc,
1981 typename _ExtractKey, typename _Equal,
1982 typename _H1, typename _H2, typename _Hash,
1983 typename _RehashPolicy, typename _Traits>
1984 bool
1985 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
1986 _H1, _H2, _Hash, _RehashPolicy, _Traits, false>::
1987 _M_equal(const __hashtable& __other) const
1988 {
1989 const __hashtable* __this = static_cast<const __hashtable*>(this);
1990
1991 if (__this->size() != __other.size())
1992 return false;
1993
1994 for (auto __itx = __this->begin(); __itx != __this->end();)
1995 {
1996 const auto __xrange = __this->equal_range(_ExtractKey()(*__itx));
1997 const auto __yrange = __other.equal_range(_ExtractKey()(*__itx));
1998
1999 if (std::distance(__xrange.first, __xrange.second)
2000 != std::distance(__yrange.first, __yrange.second))
2001 return false;
2002
2003 if (!_S_is_permutation(__xrange.first, __xrange.second,
2004 __yrange.first))
2005 return false;
2006
2007 __itx = __xrange.second;
2008 }
2009 return true;
2010 }
2011
2012 /**
2013 * This type deals with all allocation and keeps an allocator instance through
2014 * inheritance to benefit from EBO when possible.
2015 */
2016 template<typename _NodeAlloc>
2017 struct _Hashtable_alloc : private _Hashtable_ebo_helper<0, _NodeAlloc>
2018 {
2019 private:
2020 using __ebo_node_alloc = _Hashtable_ebo_helper<0, _NodeAlloc>;
2021 public:
2022 using __node_type = typename _NodeAlloc::value_type;
2023 using __node_alloc_type = _NodeAlloc;
2024 // Use __gnu_cxx to benefit from _S_always_equal and al.
2025 using __node_alloc_traits = __gnu_cxx::__alloc_traits<__node_alloc_type>;
2026
2027 using __value_alloc_traits = typename __node_alloc_traits::template
2028 rebind_traits<typename __node_type::value_type>;
2029
2030 using __node_base = __detail::_Hash_node_base;
2031 using __bucket_type = __node_base*;
2032 using __bucket_alloc_type =
2033 __alloc_rebind<__node_alloc_type, __bucket_type>;
2034 using __bucket_alloc_traits = std::allocator_traits<__bucket_alloc_type>;
2035
2036 _Hashtable_alloc() = default;
2037 _Hashtable_alloc(const _Hashtable_alloc&) = default;
2038 _Hashtable_alloc(_Hashtable_alloc&&) = default;
2039
2040 template<typename _Alloc>
2041 _Hashtable_alloc(_Alloc&& __a)
2042 : __ebo_node_alloc(std::forward<_Alloc>(__a))
2043 { }
2044
2045 __node_alloc_type&
2046 _M_node_allocator()
2047 { return __ebo_node_alloc::_S_get(*this); }
2048
2049 const __node_alloc_type&
2050 _M_node_allocator() const
2051 { return __ebo_node_alloc::_S_cget(*this); }
2052
2053 template<typename... _Args>
2054 __node_type*
2055 _M_allocate_node(_Args&&... __args);
2056
2057 void
2058 _M_deallocate_node(__node_type* __n);
2059
2060 void
2061 _M_deallocate_node_ptr(__node_type* __n);
2062
2063 // Deallocate the linked list of nodes pointed to by __n
2064 void
2065 _M_deallocate_nodes(__node_type* __n);
2066
2067 __bucket_type*
2068 _M_allocate_buckets(std::size_t __n);
2069
2070 void
2071 _M_deallocate_buckets(__bucket_type*, std::size_t __n);
2072 };
2073
2074 // Definitions of class template _Hashtable_alloc's out-of-line member
2075 // functions.
2076 template<typename _NodeAlloc>
2077 template<typename... _Args>
2078 typename _Hashtable_alloc<_NodeAlloc>::__node_type*
2079 _Hashtable_alloc<_NodeAlloc>::_M_allocate_node(_Args&&... __args)
2080 {
2081 auto __nptr = __node_alloc_traits::allocate(_M_node_allocator(), 1);
2082 __node_type* __n = std::__to_address(__nptr);
2083 __try
2084 {
2085 ::new ((void*)__n) __node_type;
2086 __node_alloc_traits::construct(_M_node_allocator(),
2087 __n->_M_valptr(),
2088 std::forward<_Args>(__args)...);
2089 return __n;
2090 }
2091 __catch(...)
2092 {
2093 __node_alloc_traits::deallocate(_M_node_allocator(), __nptr, 1);
2094 __throw_exception_again;
2095 }
2096 }
2097
2098 template<typename _NodeAlloc>
2099 void
2100 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node(__node_type* __n)
2101 {
2102 __node_alloc_traits::destroy(_M_node_allocator(), __n->_M_valptr());
2103 _M_deallocate_node_ptr(__n);
2104 }
2105
2106 template<typename _NodeAlloc>
2107 void
2108 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node_ptr(__node_type* __n)
2109 {
2110 typedef typename __node_alloc_traits::pointer _Ptr;
2111 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__n);
2112 __n->~__node_type();
2113 __node_alloc_traits::deallocate(_M_node_allocator(), __ptr, 1);
2114 }
2115
2116 template<typename _NodeAlloc>
2117 void
2118 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_nodes(__node_type* __n)
2119 {
2120 while (__n)
2121 {
2122 __node_type* __tmp = __n;
2123 __n = __n->_M_next();
2124 _M_deallocate_node(__tmp);
2125 }
2126 }
2127
2128 template<typename _NodeAlloc>
2129 typename _Hashtable_alloc<_NodeAlloc>::__bucket_type*
2130 _Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets(std::size_t __n)
2131 {
2132 __bucket_alloc_type __alloc(_M_node_allocator());
2133
2134 auto __ptr = __bucket_alloc_traits::allocate(__alloc, __n);
2135 __bucket_type* __p = std::__to_address(__ptr);
2136 __builtin_memset(__p, 0, __n * sizeof(__bucket_type));
2137 return __p;
2138 }
2139
2140 template<typename _NodeAlloc>
2141 void
2142 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_buckets(__bucket_type* __bkts,
2143 std::size_t __n)
2144 {
2145 typedef typename __bucket_alloc_traits::pointer _Ptr;
2146 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__bkts);
2147 __bucket_alloc_type __alloc(_M_node_allocator());
2148 __bucket_alloc_traits::deallocate(__alloc, __ptr, __n);
2149 }
2150
2151 //@} hashtable-detail
2152} // namespace __detail
2153_GLIBCXX_END_NAMESPACE_VERSION
2154} // namespace std
2155
2156#endif // _HASHTABLE_POLICY_H
2157