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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 :
38 : namespace 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 :
48 : namespace __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 0 : _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 712 : 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 0 : _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 712 : 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 0 : _M_node_allocator()
2047 0 : { 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 712 : _Hashtable_alloc<_NodeAlloc>::_M_deallocate_nodes(__node_type* __n)
2119 : {
2120 712 : while (__n)
2121 : {
2122 0 : __node_type* __tmp = __n;
2123 0 : __n = __n->_M_next();
2124 0 : _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 0 : _Hashtable_alloc<_NodeAlloc>::_M_deallocate_buckets(__bucket_type* __bkts,
2143 : std::size_t __n)
2144 : {
2145 : typedef typename __bucket_alloc_traits::pointer _Ptr;
2146 0 : auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__bkts);
2147 0 : __bucket_alloc_type __alloc(_M_node_allocator());
2148 0 : __bucket_alloc_traits::deallocate(__alloc, __ptr, __n);
2149 0 : }
2150 :
2151 : ///@} hashtable-detail
2152 : } // namespace __detail
2153 : _GLIBCXX_END_NAMESPACE_VERSION
2154 : } // namespace std
2155 :
2156 : #endif // _HASHTABLE_POLICY_H
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