1// hashtable.h header -*- C++ -*- 2 3// Copyright (C) 2007-2013 Free Software Foundation, Inc. 4// 5// This file is part of the GNU ISO C++ Library. This library is free 6// software; you can redistribute it and/or modify it under the 7// terms of the GNU General Public License as published by the 8// Free Software Foundation; either version 3, or (at your option) 9// any later version. 10 11// This library is distributed in the hope that it will be useful, 12// but WITHOUT ANY WARRANTY; without even the implied warranty of 13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14// GNU General Public License for more details. 15 16// Under Section 7 of GPL version 3, you are granted additional 17// permissions described in the GCC Runtime Library Exception, version 18// 3.1, as published by the Free Software Foundation. 19 20// You should have received a copy of the GNU General Public License and 21// a copy of the GCC Runtime Library Exception along with this program; 22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23// <http://www.gnu.org/licenses/>. 24 25/** @file bits/hashtable.h 26 * This is an internal header file, included by other library headers. 27 * Do not attempt to use it directly. @headername{unordered_map, unordered_set} 28 */ 29 30#ifndef _HASHTABLE_H 31#define _HASHTABLE_H 1 32 33#pragma GCC system_header 34 35#include <bits/hashtable_policy.h> 36 37namespace std _GLIBCXX_VISIBILITY(default) 38{ 39_GLIBCXX_BEGIN_NAMESPACE_VERSION 40 41 template<typename _Tp, typename _Hash> 42 using __cache_default 43 = __not_<__and_<// Do not cache for fast hasher. 44 __is_fast_hash<_Hash>, 45 // Mandatory to make local_iterator default 46 // constructible and assignable. 47 is_default_constructible<_Hash>, 48 is_copy_assignable<_Hash>, 49 // Mandatory to have erase not throwing. 50 __detail::__is_noexcept_hash<_Tp, _Hash>>>; 51 52 /** 53 * Primary class template _Hashtable. 54 * 55 * @ingroup hashtable-detail 56 * 57 * @tparam _Value CopyConstructible type. 58 * 59 * @tparam _Key CopyConstructible type. 60 * 61 * @tparam _Alloc An allocator type 62 * ([lib.allocator.requirements]) whose _Alloc::value_type is 63 * _Value. As a conforming extension, we allow for 64 * _Alloc::value_type != _Value. 65 * 66 * @tparam _ExtractKey Function object that takes an object of type 67 * _Value and returns a value of type _Key. 68 * 69 * @tparam _Equal Function object that takes two objects of type k 70 * and returns a bool-like value that is true if the two objects 71 * are considered equal. 72 * 73 * @tparam _H1 The hash function. A unary function object with 74 * argument type _Key and result type size_t. Return values should 75 * be distributed over the entire range [0, numeric_limits<size_t>:::max()]. 76 * 77 * @tparam _H2 The range-hashing function (in the terminology of 78 * Tavori and Dreizin). A binary function object whose argument 79 * types and result type are all size_t. Given arguments r and N, 80 * the return value is in the range [0, N). 81 * 82 * @tparam _Hash The ranged hash function (Tavori and Dreizin). A 83 * binary function whose argument types are _Key and size_t and 84 * whose result type is size_t. Given arguments k and N, the 85 * return value is in the range [0, N). Default: hash(k, N) = 86 * h2(h1(k), N). If _Hash is anything other than the default, _H1 87 * and _H2 are ignored. 88 * 89 * @tparam _RehashPolicy Policy class with three members, all of 90 * which govern the bucket count. _M_next_bkt(n) returns a bucket 91 * count no smaller than n. _M_bkt_for_elements(n) returns a 92 * bucket count appropriate for an element count of n. 93 * _M_need_rehash(n_bkt, n_elt, n_ins) determines whether, if the 94 * current bucket count is n_bkt and the current element count is 95 * n_elt, we need to increase the bucket count. If so, returns 96 * make_pair(true, n), where n is the new bucket count. If not, 97 * returns make_pair(false, <anything>) 98 * 99 * @tparam _Traits Compile-time class with three boolean 100 * std::integral_constant members: __cache_hash_code, __constant_iterators, 101 * __unique_keys. 102 * 103 * Each _Hashtable data structure has: 104 * 105 * - _Bucket[] _M_buckets 106 * - _Hash_node_base _M_bbegin 107 * - size_type _M_bucket_count 108 * - size_type _M_element_count 109 * 110 * with _Bucket being _Hash_node* and _Hash_node containing: 111 * 112 * - _Hash_node* _M_next 113 * - Tp _M_value 114 * - size_t _M_hash_code if cache_hash_code is true 115 * 116 * In terms of Standard containers the hashtable is like the aggregation of: 117 * 118 * - std::forward_list<_Node> containing the elements 119 * - std::vector<std::forward_list<_Node>::iterator> representing the buckets 120 * 121 * The non-empty buckets contain the node before the first node in the 122 * bucket. This design makes it possible to implement something like a 123 * std::forward_list::insert_after on container insertion and 124 * std::forward_list::erase_after on container erase 125 * calls. _M_before_begin is equivalent to 126 * std::forward_list::before_begin. Empty buckets contain 127 * nullptr. Note that one of the non-empty buckets contains 128 * &_M_before_begin which is not a dereferenceable node so the 129 * node pointer in a bucket shall never be dereferenced, only its 130 * next node can be. 131 * 132 * Walking through a bucket's nodes requires a check on the hash code to 133 * see if each node is still in the bucket. Such a design assumes a 134 * quite efficient hash functor and is one of the reasons it is 135 * highly advisable to set __cache_hash_code to true. 136 * 137 * The container iterators are simply built from nodes. This way 138 * incrementing the iterator is perfectly efficient independent of 139 * how many empty buckets there are in the container. 140 * 141 * On insert we compute the element's hash code and use it to find the 142 * bucket index. If the element must be inserted in an empty bucket 143 * we add it at the beginning of the singly linked list and make the 144 * bucket point to _M_before_begin. The bucket that used to point to 145 * _M_before_begin, if any, is updated to point to its new before 146 * begin node. 147 * 148 * On erase, the simple iterator design requires using the hash 149 * functor to get the index of the bucket to update. For this 150 * reason, when __cache_hash_code is set to false the hash functor must 151 * not throw and this is enforced by a static assertion. 152 * 153 * Functionality is implemented by decomposition into base classes, 154 * where the derived _Hashtable class is used in _Map_base, 155 * _Insert, _Rehash_base, and _Equality base classes to access the 156 * "this" pointer. _Hashtable_base is used in the base classes as a 157 * non-recursive, fully-completed-type so that detailed nested type 158 * information, such as iterator type and node type, can be 159 * used. This is similar to the "Curiously Recurring Template 160 * Pattern" (CRTP) technique, but uses a reconstructed, not 161 * explicitly passed, template pattern. 162 * 163 * Base class templates are: 164 * - __detail::_Hashtable_base 165 * - __detail::_Map_base 166 * - __detail::_Insert 167 * - __detail::_Rehash_base 168 * - __detail::_Equality 169 */ 170 template<typename _Key, typename _Value, typename _Alloc, 171 typename _ExtractKey, typename _Equal, 172 typename _H1, typename _H2, typename _Hash, 173 typename _RehashPolicy, typename _Traits> 174 class _Hashtable 175 : public __detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, 176 _H1, _H2, _Hash, _Traits>, 177 public __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 178 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 179 public __detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, 180 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 181 public __detail::_Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 182 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 183 public __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 184 _H1, _H2, _Hash, _RehashPolicy, _Traits> 185 { 186 public: 187 typedef _Key key_type; 188 typedef _Value value_type; 189 typedef _Alloc allocator_type; 190 typedef _Equal key_equal; 191 192 // mapped_type, if present, comes from _Map_base. 193 // hasher, if present, comes from _Hash_code_base/_Hashtable_base. 194 typedef typename _Alloc::pointer pointer; 195 typedef typename _Alloc::const_pointer const_pointer; 196 typedef typename _Alloc::reference reference; 197 typedef typename _Alloc::const_reference const_reference; 198 199 private: 200 using __rehash_type = _RehashPolicy; 201 using __rehash_state = typename __rehash_type::_State; 202 203 using __traits_type = _Traits; 204 using __hash_cached = typename __traits_type::__hash_cached; 205 using __constant_iterators = typename __traits_type::__constant_iterators; 206 using __unique_keys = typename __traits_type::__unique_keys; 207 208 using __key_extract = typename std::conditional< 209 __constant_iterators::value, 210 __detail::_Identity, 211 __detail::_Select1st>::type; 212 213 using __hashtable_base = __detail:: 214 _Hashtable_base<_Key, _Value, _ExtractKey, 215 _Equal, _H1, _H2, _Hash, _Traits>; 216 217 using __hash_code_base = typename __hashtable_base::__hash_code_base; 218 using __hash_code = typename __hashtable_base::__hash_code; 219 using __node_type = typename __hashtable_base::__node_type; 220 using __node_base = typename __hashtable_base::__node_base; 221 using __bucket_type = typename __hashtable_base::__bucket_type; 222 using __ireturn_type = typename __hashtable_base::__ireturn_type; 223 using __iconv_type = typename __hashtable_base::__iconv_type; 224 225 using __map_base = __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, 226 _Equal, _H1, _H2, _Hash, 227 _RehashPolicy, _Traits>; 228 229 using __rehash_base = __detail::_Rehash_base<_Key, _Value, _Alloc, 230 _ExtractKey, _Equal, 231 _H1, _H2, _Hash, 232 _RehashPolicy, _Traits>; 233 234 using __eq_base = __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, 235 _Equal, _H1, _H2, _Hash, 236 _RehashPolicy, _Traits>; 237 238 // Metaprogramming for picking apart hash caching. 239 using __hash_noexcept = __detail::__is_noexcept_hash<_Key, _H1>; 240 241 template<typename _Cond> 242 using __if_hash_cached = __or_<__not_<__hash_cached>, _Cond>; 243 244 template<typename _Cond> 245 using __if_hash_not_cached = __or_<__hash_cached, _Cond>; 246 247 // Compile-time diagnostics. 248 249 // When hash codes are not cached the hash functor shall not 250 // throw because it is used in methods (erase, swap...) that 251 // shall not throw. 252 static_assert(__if_hash_not_cached<__hash_noexcept>::value, 253 "Cache the hash code" 254 " or qualify your hash functor with noexcept"); 255 256 // Following two static assertions are necessary to guarantee 257 // that local_iterator will be default constructible. 258 259 // When hash codes are cached local iterator inherits from H2 functor 260 // which must then be default constructible. 261 static_assert(__if_hash_cached<is_default_constructible<_H2>>::value, 262 "Functor used to map hash code to bucket index" 263 " must be default constructible"); 264 265 // When hash codes are not cached local iterator inherits from 266 // __hash_code_base above to compute node bucket index so it has to be 267 // default constructible. 268 static_assert(__if_hash_not_cached< 269 is_default_constructible< 270 // We use _Hashtable_ebo_helper to access the protected 271 // default constructor. 272 __detail::_Hashtable_ebo_helper<0, __hash_code_base>>>::value, 273 "Cache the hash code or make functors involved in hash code" 274 " and bucket index computation default constructible"); 275 276 // When hash codes are not cached local iterator inherits from 277 // __hash_code_base above to compute node bucket index so it has to be 278 // assignable. 279 static_assert(__if_hash_not_cached< 280 is_copy_assignable<__hash_code_base>>::value, 281 "Cache the hash code or make functors involved in hash code" 282 " and bucket index computation copy assignable"); 283 284 public: 285 template<typename _Keya, typename _Valuea, typename _Alloca, 286 typename _ExtractKeya, typename _Equala, 287 typename _H1a, typename _H2a, typename _Hasha, 288 typename _RehashPolicya, typename _Traitsa, 289 bool _Unique_keysa> 290 friend struct __detail::_Map_base; 291 292 template<typename _Keya, typename _Valuea, typename _Alloca, 293 typename _ExtractKeya, typename _Equala, 294 typename _H1a, typename _H2a, typename _Hasha, 295 typename _RehashPolicya, typename _Traitsa> 296 friend struct __detail::_Insert_base; 297 298 template<typename _Keya, typename _Valuea, typename _Alloca, 299 typename _ExtractKeya, typename _Equala, 300 typename _H1a, typename _H2a, typename _Hasha, 301 typename _RehashPolicya, typename _Traitsa, 302 bool _Constant_iteratorsa, bool _Unique_keysa> 303 friend struct __detail::_Insert; 304 305 using size_type = typename __hashtable_base::size_type; 306 using difference_type = typename __hashtable_base::difference_type; 307 308 using iterator = typename __hashtable_base::iterator; 309 using const_iterator = typename __hashtable_base::const_iterator; 310 311 using local_iterator = typename __hashtable_base::local_iterator; 312 using const_local_iterator = typename __hashtable_base:: 313 const_local_iterator; 314 315 private: 316 typedef typename _Alloc::template rebind<__node_type>::other 317 _Node_allocator_type; 318 typedef typename _Alloc::template rebind<__bucket_type>::other 319 _Bucket_allocator_type; 320 321 using __before_begin = __detail::_Before_begin<_Node_allocator_type>; 322 323 __bucket_type* _M_buckets; 324 size_type _M_bucket_count; 325 __before_begin _M_bbegin; 326 size_type _M_element_count; 327 _RehashPolicy _M_rehash_policy; 328 329 _Node_allocator_type& 330 _M_node_allocator() 331 { return _M_bbegin; } 332 333 const _Node_allocator_type& 334 _M_node_allocator() const 335 { return _M_bbegin; } 336 337 __node_base& 338 _M_before_begin() 339 { return _M_bbegin._M_node; } 340 341 const __node_base& 342 _M_before_begin() const 343 { return _M_bbegin._M_node; } 344 345 template<typename... _Args> 346 __node_type* 347 _M_allocate_node(_Args&&... __args); 348 349 void 350 _M_deallocate_node(__node_type* __n); 351 352 // Deallocate the linked list of nodes pointed to by __n 353 void 354 _M_deallocate_nodes(__node_type* __n); 355 356 __bucket_type* 357 _M_allocate_buckets(size_type __n); 358 359 void 360 _M_deallocate_buckets(__bucket_type*, size_type __n); 361 362 // Gets bucket begin, deals with the fact that non-empty buckets contain 363 // their before begin node. 364 __node_type* 365 _M_bucket_begin(size_type __bkt) const; 366 367 __node_type* 368 _M_begin() const 369 { return static_cast<__node_type*>(_M_before_begin()._M_nxt); } 370 371 public: 372 // Constructor, destructor, assignment, swap 373 _Hashtable(size_type __bucket_hint, 374 const _H1&, const _H2&, const _Hash&, 375 const _Equal&, const _ExtractKey&, 376 const allocator_type&); 377 378 template<typename _InputIterator> 379 _Hashtable(_InputIterator __first, _InputIterator __last, 380 size_type __bucket_hint, 381 const _H1&, const _H2&, const _Hash&, 382 const _Equal&, const _ExtractKey&, 383 const allocator_type&); 384 385 _Hashtable(const _Hashtable&); 386 387 _Hashtable(_Hashtable&&); 388 389 // Use delegating constructors. 390 explicit 391 _Hashtable(size_type __n = 10, 392 const _H1& __hf = _H1(), 393 const key_equal& __eql = key_equal(), 394 const allocator_type& __a = allocator_type()) 395 : _Hashtable(__n, __hf, __detail::_Mod_range_hashing(), 396 __detail::_Default_ranged_hash(), __eql, 397 __key_extract(), __a) 398 { } 399 400 template<typename _InputIterator> 401 _Hashtable(_InputIterator __f, _InputIterator __l, 402 size_type __n = 0, 403 const _H1& __hf = _H1(), 404 const key_equal& __eql = key_equal(), 405 const allocator_type& __a = allocator_type()) 406 : _Hashtable(__f, __l, __n, __hf, __detail::_Mod_range_hashing(), 407 __detail::_Default_ranged_hash(), __eql, 408 __key_extract(), __a) 409 { } 410 411 _Hashtable(initializer_list<value_type> __l, 412 size_type __n = 0, 413 const _H1& __hf = _H1(), 414 const key_equal& __eql = key_equal(), 415 const allocator_type& __a = allocator_type()) 416 : _Hashtable(__l.begin(), __l.end(), __n, __hf, 417 __detail::_Mod_range_hashing(), 418 __detail::_Default_ranged_hash(), __eql, 419 __key_extract(), __a) 420 { } 421 422 _Hashtable& 423 operator=(const _Hashtable& __ht) 424 { 425 _Hashtable __tmp(__ht); 426 this->swap(__tmp); 427 return *this; 428 } 429 430 _Hashtable& 431 operator=(_Hashtable&& __ht) 432 { 433 // NB: DR 1204. 434 // NB: DR 675. 435 this->clear(); 436 this->swap(__ht); 437 return *this; 438 } 439 440 _Hashtable& 441 operator=(initializer_list<value_type> __l) 442 { 443 this->clear(); 444 this->insert(__l.begin(), __l.end()); 445 return *this; 446 } 447 448 ~_Hashtable() noexcept; 449 450 void swap(_Hashtable&); 451 452 // Basic container operations 453 iterator 454 begin() noexcept 455 { return iterator(_M_begin()); } 456 457 const_iterator 458 begin() const noexcept 459 { return const_iterator(_M_begin()); } 460 461 iterator 462 end() noexcept 463 { return iterator(nullptr); } 464 465 const_iterator 466 end() const noexcept 467 { return const_iterator(nullptr); } 468 469 const_iterator 470 cbegin() const noexcept 471 { return const_iterator(_M_begin()); } 472 473 const_iterator 474 cend() const noexcept 475 { return const_iterator(nullptr); } 476 477 size_type 478 size() const noexcept 479 { return _M_element_count; } 480 481 bool 482 empty() const noexcept 483 { return size() == 0; } 484 485 allocator_type 486 get_allocator() const noexcept 487 { return allocator_type(_M_node_allocator()); } 488 489 size_type 490 max_size() const noexcept 491 { return _M_node_allocator().max_size(); } 492 493 // Observers 494 key_equal 495 key_eq() const 496 { return this->_M_eq(); } 497 498 // hash_function, if present, comes from _Hash_code_base. 499 500 // Bucket operations 501 size_type 502 bucket_count() const noexcept 503 { return _M_bucket_count; } 504 505 size_type 506 max_bucket_count() const noexcept 507 { return max_size(); } 508 509 size_type 510 bucket_size(size_type __n) const 511 { return std::distance(begin(__n), end(__n)); } 512 513 size_type 514 bucket(const key_type& __k) const 515 { return _M_bucket_index(__k, this->_M_hash_code(__k)); } 516 517 local_iterator 518 begin(size_type __n) 519 { 520 return local_iterator(*this, _M_bucket_begin(__n), 521 __n, _M_bucket_count); 522 } 523 524 local_iterator 525 end(size_type __n) 526 { return local_iterator(*this, nullptr, __n, _M_bucket_count); } 527 528 const_local_iterator 529 begin(size_type __n) const 530 { 531 return const_local_iterator(*this, _M_bucket_begin(__n), 532 __n, _M_bucket_count); 533 } 534 535 const_local_iterator 536 end(size_type __n) const 537 { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); } 538 539 // DR 691. 540 const_local_iterator 541 cbegin(size_type __n) const 542 { 543 return const_local_iterator(*this, _M_bucket_begin(__n), 544 __n, _M_bucket_count); 545 } 546 547 const_local_iterator 548 cend(size_type __n) const 549 { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); } 550 551 float 552 load_factor() const noexcept 553 { 554 return static_cast<float>(size()) / static_cast<float>(bucket_count()); 555 } 556 557 // max_load_factor, if present, comes from _Rehash_base. 558 559 // Generalization of max_load_factor. Extension, not found in 560 // TR1. Only useful if _RehashPolicy is something other than 561 // the default. 562 const _RehashPolicy& 563 __rehash_policy() const 564 { return _M_rehash_policy; } 565 566 void 567 __rehash_policy(const _RehashPolicy&); 568 569 // Lookup. 570 iterator 571 find(const key_type& __k); 572 573 const_iterator 574 find(const key_type& __k) const; 575 576 size_type 577 count(const key_type& __k) const; 578 579 std::pair<iterator, iterator> 580 equal_range(const key_type& __k); 581 582 std::pair<const_iterator, const_iterator> 583 equal_range(const key_type& __k) const; 584 585 protected: 586 // Bucket index computation helpers. 587 size_type 588 _M_bucket_index(__node_type* __n) const 589 { return __hash_code_base::_M_bucket_index(__n, _M_bucket_count); } 590 591 size_type 592 _M_bucket_index(const key_type& __k, __hash_code __c) const 593 { return __hash_code_base::_M_bucket_index(__k, __c, _M_bucket_count); } 594 595 // Find and insert helper functions and types 596 // Find the node before the one matching the criteria. 597 __node_base* 598 _M_find_before_node(size_type, const key_type&, __hash_code) const; 599 600 __node_type* 601 _M_find_node(size_type __bkt, const key_type& __key, 602 __hash_code __c) const 603 { 604 __node_base* __before_n = _M_find_before_node(__bkt, __key, __c); 605 if (__before_n) 606 return static_cast<__node_type*>(__before_n->_M_nxt); 607 return nullptr; 608 } 609 610 // Insert a node at the beginning of a bucket. 611 void 612 _M_insert_bucket_begin(size_type, __node_type*); 613 614 // Remove the bucket first node 615 void 616 _M_remove_bucket_begin(size_type __bkt, __node_type* __next_n, 617 size_type __next_bkt); 618 619 // Get the node before __n in the bucket __bkt 620 __node_base* 621 _M_get_previous_node(size_type __bkt, __node_base* __n); 622 623 // Insert node with hash code __code, in bucket bkt if no rehash (assumes 624 // no element with its key already present). Take ownership of the node, 625 // deallocate it on exception. 626 iterator 627 _M_insert_unique_node(size_type __bkt, __hash_code __code, 628 __node_type* __n); 629 630 // Insert node with hash code __code. Take ownership of the node, 631 // deallocate it on exception. 632 iterator 633 _M_insert_multi_node(__hash_code __code, __node_type* __n); 634 635 template<typename... _Args> 636 std::pair<iterator, bool> 637 _M_emplace(std::true_type, _Args&&... __args); 638 639 template<typename... _Args> 640 iterator 641 _M_emplace(std::false_type, _Args&&... __args); 642 643 template<typename _Arg> 644 std::pair<iterator, bool> 645 _M_insert(_Arg&&, std::true_type); 646 647 template<typename _Arg> 648 iterator 649 _M_insert(_Arg&&, std::false_type); 650 651 size_type 652 _M_erase(std::true_type, const key_type&); 653 654 size_type 655 _M_erase(std::false_type, const key_type&); 656 657 iterator 658 _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n); 659 660 public: 661 // Emplace 662 template<typename... _Args> 663 __ireturn_type 664 emplace(_Args&&... __args) 665 { return _M_emplace(__unique_keys(), std::forward<_Args>(__args)...); } 666 667 template<typename... _Args> 668 iterator 669 emplace_hint(const_iterator, _Args&&... __args) 670 { return __iconv_type()(emplace(std::forward<_Args>(__args)...)); } 671 672 // Insert member functions via inheritance. 673 674 // Erase 675 iterator 676 erase(const_iterator); 677 678 // LWG 2059. 679 iterator 680 erase(iterator __it) 681 { return erase(const_iterator(__it)); } 682 683 size_type 684 erase(const key_type& __k) 685 { return _M_erase(__unique_keys(), __k); } 686 687 iterator 688 erase(const_iterator, const_iterator); 689 690 void 691 clear() noexcept; 692 693 // Set number of buckets to be appropriate for container of n element. 694 void rehash(size_type __n); 695 696 // DR 1189. 697 // reserve, if present, comes from _Rehash_base. 698 699 private: 700 // Helper rehash method used when keys are unique. 701 void _M_rehash_aux(size_type __n, std::true_type); 702 703 // Helper rehash method used when keys can be non-unique. 704 void _M_rehash_aux(size_type __n, std::false_type); 705 706 // Unconditionally change size of bucket array to n, restore 707 // hash policy state to __state on exception. 708 void _M_rehash(size_type __n, const __rehash_state& __state); 709 }; 710 711 712 // Definitions of class template _Hashtable's out-of-line member functions. 713 template<typename _Key, typename _Value, 714 typename _Alloc, typename _ExtractKey, typename _Equal, 715 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 716 typename _Traits> 717 template<typename... _Args> 718 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 719 _H1, _H2, _Hash, _RehashPolicy, _Traits>::__node_type* 720 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 721 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 722 _M_allocate_node(_Args&&... __args) 723 { 724 __node_type* __n = _M_node_allocator().allocate(1); 725 __try 726 { 727 _M_node_allocator().construct(__n, std::forward<_Args>(__args)...); 728 return __n; 729 } 730 __catch(...) 731 { 732 _M_node_allocator().deallocate(__n, 1); 733 __throw_exception_again; 734 } 735 } 736 737 template<typename _Key, typename _Value, 738 typename _Alloc, typename _ExtractKey, typename _Equal, 739 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 740 typename _Traits> 741 void 742 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 743 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 744 _M_deallocate_node(__node_type* __n) 745 { 746 _M_node_allocator().destroy(__n); 747 _M_node_allocator().deallocate(__n, 1); 748 } 749 750 template<typename _Key, typename _Value, 751 typename _Alloc, typename _ExtractKey, typename _Equal, 752 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 753 typename _Traits> 754 void 755 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 756 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 757 _M_deallocate_nodes(__node_type* __n) 758 { 759 while (__n) 760 { 761 __node_type* __tmp = __n; 762 __n = __n->_M_next(); 763 _M_deallocate_node(__tmp); 764 } 765 } 766 767 template<typename _Key, typename _Value, 768 typename _Alloc, typename _ExtractKey, typename _Equal, 769 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 770 typename _Traits> 771 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 772 _H1, _H2, _Hash, _RehashPolicy, _Traits>::__bucket_type* 773 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 774 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 775 _M_allocate_buckets(size_type __n) 776 { 777 _Bucket_allocator_type __alloc(_M_node_allocator()); 778 779 __bucket_type* __p = __alloc.allocate(__n); 780 __builtin_memset(__p, 0, __n * sizeof(__bucket_type)); 781 return __p; 782 } 783 784 template<typename _Key, typename _Value, 785 typename _Alloc, typename _ExtractKey, typename _Equal, 786 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 787 typename _Traits> 788 void 789 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 790 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 791 _M_deallocate_buckets(__bucket_type* __p, size_type __n) 792 { 793 _Bucket_allocator_type __alloc(_M_node_allocator()); 794 __alloc.deallocate(__p, __n); 795 } 796 797 template<typename _Key, typename _Value, 798 typename _Alloc, typename _ExtractKey, typename _Equal, 799 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 800 typename _Traits> 801 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, 802 _Equal, _H1, _H2, _Hash, _RehashPolicy, 803 _Traits>::__node_type* 804 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 805 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 806 _M_bucket_begin(size_type __bkt) const 807 { 808 __node_base* __n = _M_buckets[__bkt]; 809 return __n ? static_cast<__node_type*>(__n->_M_nxt) : nullptr; 810 } 811 812 template<typename _Key, typename _Value, 813 typename _Alloc, typename _ExtractKey, typename _Equal, 814 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 815 typename _Traits> 816 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 817 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 818 _Hashtable(size_type __bucket_hint, 819 const _H1& __h1, const _H2& __h2, const _Hash& __h, 820 const _Equal& __eq, const _ExtractKey& __exk, 821 const allocator_type& __a) 822 : __hashtable_base(__exk, __h1, __h2, __h, __eq), 823 __map_base(), 824 __rehash_base(), 825 _M_bucket_count(0), 826 _M_bbegin(__a), 827 _M_element_count(0), 828 _M_rehash_policy() 829 { 830 _M_bucket_count = _M_rehash_policy._M_next_bkt(__bucket_hint); 831 _M_buckets = _M_allocate_buckets(_M_bucket_count); 832 } 833 834 template<typename _Key, typename _Value, 835 typename _Alloc, typename _ExtractKey, typename _Equal, 836 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 837 typename _Traits> 838 template<typename _InputIterator> 839 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 840 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 841 _Hashtable(_InputIterator __f, _InputIterator __l, 842 size_type __bucket_hint, 843 const _H1& __h1, const _H2& __h2, const _Hash& __h, 844 const _Equal& __eq, const _ExtractKey& __exk, 845 const allocator_type& __a) 846 : __hashtable_base(__exk, __h1, __h2, __h, __eq), 847 __map_base(), 848 __rehash_base(), 849 _M_bucket_count(0), 850 _M_bbegin(__a), 851 _M_element_count(0), 852 _M_rehash_policy() 853 { 854 auto __nb_elems = __detail::__distance_fw(__f, __l); 855 _M_bucket_count = 856 _M_rehash_policy._M_next_bkt( 857 std::max(_M_rehash_policy._M_bkt_for_elements(__nb_elems), 858 __bucket_hint)); 859 860 _M_buckets = _M_allocate_buckets(_M_bucket_count); 861 __try 862 { 863 for (; __f != __l; ++__f) 864 this->insert(*__f); 865 } 866 __catch(...) 867 { 868 clear(); 869 _M_deallocate_buckets(_M_buckets, _M_bucket_count); 870 __throw_exception_again; 871 } 872 } 873 874 template<typename _Key, typename _Value, 875 typename _Alloc, typename _ExtractKey, typename _Equal, 876 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 877 typename _Traits> 878 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 879 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 880 _Hashtable(const _Hashtable& __ht) 881 : __hashtable_base(__ht), 882 __map_base(__ht), 883 __rehash_base(__ht), 884 _M_bucket_count(__ht._M_bucket_count), 885 _M_bbegin(__ht._M_bbegin), 886 _M_element_count(__ht._M_element_count), 887 _M_rehash_policy(__ht._M_rehash_policy) 888 { 889 _M_buckets = _M_allocate_buckets(_M_bucket_count); 890 __try 891 { 892 if (!__ht._M_before_begin()._M_nxt) 893 return; 894 895 // First deal with the special first node pointed to by 896 // _M_before_begin. 897 const __node_type* __ht_n = __ht._M_begin(); 898 __node_type* __this_n = _M_allocate_node(__ht_n->_M_v); 899 this->_M_copy_code(__this_n, __ht_n); 900 _M_before_begin()._M_nxt = __this_n; 901 _M_buckets[_M_bucket_index(__this_n)] = &_M_before_begin(); 902 903 // Then deal with other nodes. 904 __node_base* __prev_n = __this_n; 905 for (__ht_n = __ht_n->_M_next(); __ht_n; __ht_n = __ht_n->_M_next()) 906 { 907 __this_n = _M_allocate_node(__ht_n->_M_v); 908 __prev_n->_M_nxt = __this_n; 909 this->_M_copy_code(__this_n, __ht_n); 910 size_type __bkt = _M_bucket_index(__this_n); 911 if (!_M_buckets[__bkt]) 912 _M_buckets[__bkt] = __prev_n; 913 __prev_n = __this_n; 914 } 915 } 916 __catch(...) 917 { 918 clear(); 919 _M_deallocate_buckets(_M_buckets, _M_bucket_count); 920 __throw_exception_again; 921 } 922 } 923 924 template<typename _Key, typename _Value, 925 typename _Alloc, typename _ExtractKey, typename _Equal, 926 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 927 typename _Traits> 928 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 929 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 930 _Hashtable(_Hashtable&& __ht) 931 : __hashtable_base(__ht), 932 __map_base(__ht), 933 __rehash_base(__ht), 934 _M_buckets(__ht._M_buckets), 935 _M_bucket_count(__ht._M_bucket_count), 936 _M_bbegin(std::move(__ht._M_bbegin)), 937 _M_element_count(__ht._M_element_count), 938 _M_rehash_policy(__ht._M_rehash_policy) 939 { 940 // Update, if necessary, bucket pointing to before begin that hasn't moved. 941 if (_M_begin()) 942 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin(); 943 __ht._M_rehash_policy = _RehashPolicy(); 944 __ht._M_bucket_count = __ht._M_rehash_policy._M_next_bkt(0); 945 __ht._M_buckets = __ht._M_allocate_buckets(__ht._M_bucket_count); 946 __ht._M_before_begin()._M_nxt = nullptr; 947 __ht._M_element_count = 0; 948 } 949 950 template<typename _Key, typename _Value, 951 typename _Alloc, typename _ExtractKey, typename _Equal, 952 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 953 typename _Traits> 954 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 955 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 956 ~_Hashtable() noexcept 957 { 958 clear(); 959 _M_deallocate_buckets(_M_buckets, _M_bucket_count); 960 } 961 962 template<typename _Key, typename _Value, 963 typename _Alloc, typename _ExtractKey, typename _Equal, 964 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 965 typename _Traits> 966 void 967 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 968 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 969 swap(_Hashtable& __x) 970 { 971 // The only base class with member variables is hash_code_base. 972 // We define _Hash_code_base::_M_swap because different 973 // specializations have different members. 974 this->_M_swap(__x); 975 976 // _GLIBCXX_RESOLVE_LIB_DEFECTS 977 // 431. Swapping containers with unequal allocators. 978 std::__alloc_swap<_Node_allocator_type>::_S_do_it(_M_node_allocator(), 979 __x._M_node_allocator()); 980 981 std::swap(_M_rehash_policy, __x._M_rehash_policy); 982 std::swap(_M_buckets, __x._M_buckets); 983 std::swap(_M_bucket_count, __x._M_bucket_count); 984 std::swap(_M_before_begin()._M_nxt, __x._M_before_begin()._M_nxt); 985 std::swap(_M_element_count, __x._M_element_count); 986 987 // Fix buckets containing the _M_before_begin pointers that 988 // can't be swapped. 989 if (_M_begin()) 990 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin(); 991 if (__x._M_begin()) 992 __x._M_buckets[__x._M_bucket_index(__x._M_begin())] 993 = &(__x._M_before_begin()); 994 } 995 996 template<typename _Key, typename _Value, 997 typename _Alloc, typename _ExtractKey, typename _Equal, 998 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 999 typename _Traits> 1000 void 1001 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1002 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1003 __rehash_policy(const _RehashPolicy& __pol) 1004 { 1005 size_type __n_bkt = __pol._M_bkt_for_elements(_M_element_count); 1006 __n_bkt = __pol._M_next_bkt(__n_bkt); 1007 if (__n_bkt != _M_bucket_count) 1008 _M_rehash(__n_bkt, _M_rehash_policy._M_state()); 1009 _M_rehash_policy = __pol; 1010 } 1011 1012 template<typename _Key, typename _Value, 1013 typename _Alloc, typename _ExtractKey, typename _Equal, 1014 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1015 typename _Traits> 1016 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1017 _H1, _H2, _Hash, _RehashPolicy, 1018 _Traits>::iterator 1019 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1020 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1021 find(const key_type& __k) 1022 { 1023 __hash_code __code = this->_M_hash_code(__k); 1024 std::size_t __n = _M_bucket_index(__k, __code); 1025 __node_type* __p = _M_find_node(__n, __k, __code); 1026 return __p ? iterator(__p) : this->end(); 1027 } 1028 1029 template<typename _Key, typename _Value, 1030 typename _Alloc, typename _ExtractKey, typename _Equal, 1031 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1032 typename _Traits> 1033 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1034 _H1, _H2, _Hash, _RehashPolicy, 1035 _Traits>::const_iterator 1036 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1037 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1038 find(const key_type& __k) const 1039 { 1040 __hash_code __code = this->_M_hash_code(__k); 1041 std::size_t __n = _M_bucket_index(__k, __code); 1042 __node_type* __p = _M_find_node(__n, __k, __code); 1043 return __p ? const_iterator(__p) : this->end(); 1044 } 1045 1046 template<typename _Key, typename _Value, 1047 typename _Alloc, typename _ExtractKey, typename _Equal, 1048 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1049 typename _Traits> 1050 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1051 _H1, _H2, _Hash, _RehashPolicy, 1052 _Traits>::size_type 1053 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1054 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1055 count(const key_type& __k) const 1056 { 1057 __hash_code __code = this->_M_hash_code(__k); 1058 std::size_t __n = _M_bucket_index(__k, __code); 1059 __node_type* __p = _M_bucket_begin(__n); 1060 if (!__p) 1061 return 0; 1062 1063 std::size_t __result = 0; 1064 for (;; __p = __p->_M_next()) 1065 { 1066 if (this->_M_equals(__k, __code, __p)) 1067 ++__result; 1068 else if (__result) 1069 // All equivalent values are next to each other, if we 1070 // found a non-equivalent value after an equivalent one it 1071 // means that we won't find any more equivalent values. 1072 break; 1073 if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n) 1074 break; 1075 } 1076 return __result; 1077 } 1078 1079 template<typename _Key, typename _Value, 1080 typename _Alloc, typename _ExtractKey, typename _Equal, 1081 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1082 typename _Traits> 1083 std::pair<typename _Hashtable<_Key, _Value, _Alloc, 1084 _ExtractKey, _Equal, _H1, 1085 _H2, _Hash, _RehashPolicy, 1086 _Traits>::iterator, 1087 typename _Hashtable<_Key, _Value, _Alloc, 1088 _ExtractKey, _Equal, _H1, 1089 _H2, _Hash, _RehashPolicy, 1090 _Traits>::iterator> 1091 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1092 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1093 equal_range(const key_type& __k) 1094 { 1095 __hash_code __code = this->_M_hash_code(__k); 1096 std::size_t __n = _M_bucket_index(__k, __code); 1097 __node_type* __p = _M_find_node(__n, __k, __code); 1098 1099 if (__p) 1100 { 1101 __node_type* __p1 = __p->_M_next(); 1102 while (__p1 && _M_bucket_index(__p1) == __n 1103 && this->_M_equals(__k, __code, __p1)) 1104 __p1 = __p1->_M_next(); 1105 1106 return std::make_pair(iterator(__p), iterator(__p1)); 1107 } 1108 else 1109 return std::make_pair(this->end(), this->end()); 1110 } 1111 1112 template<typename _Key, typename _Value, 1113 typename _Alloc, typename _ExtractKey, typename _Equal, 1114 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1115 typename _Traits> 1116 std::pair<typename _Hashtable<_Key, _Value, _Alloc, 1117 _ExtractKey, _Equal, _H1, 1118 _H2, _Hash, _RehashPolicy, 1119 _Traits>::const_iterator, 1120 typename _Hashtable<_Key, _Value, _Alloc, 1121 _ExtractKey, _Equal, _H1, 1122 _H2, _Hash, _RehashPolicy, 1123 _Traits>::const_iterator> 1124 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1125 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1126 equal_range(const key_type& __k) const 1127 { 1128 __hash_code __code = this->_M_hash_code(__k); 1129 std::size_t __n = _M_bucket_index(__k, __code); 1130 __node_type* __p = _M_find_node(__n, __k, __code); 1131 1132 if (__p) 1133 { 1134 __node_type* __p1 = __p->_M_next(); 1135 while (__p1 && _M_bucket_index(__p1) == __n 1136 && this->_M_equals(__k, __code, __p1)) 1137 __p1 = __p1->_M_next(); 1138 1139 return std::make_pair(const_iterator(__p), const_iterator(__p1)); 1140 } 1141 else 1142 return std::make_pair(this->end(), this->end()); 1143 } 1144 1145 // Find the node whose key compares equal to k in the bucket n. 1146 // Return nullptr if no node is found. 1147 template<typename _Key, typename _Value, 1148 typename _Alloc, typename _ExtractKey, typename _Equal, 1149 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1150 typename _Traits> 1151 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, 1152 _Equal, _H1, _H2, _Hash, _RehashPolicy, 1153 _Traits>::__node_base* 1154 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1155 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1156 _M_find_before_node(size_type __n, const key_type& __k, 1157 __hash_code __code) const 1158 { 1159 __node_base* __prev_p = _M_buckets[__n]; 1160 if (!__prev_p) 1161 return nullptr; 1162 __node_type* __p = static_cast<__node_type*>(__prev_p->_M_nxt); 1163 for (;; __p = __p->_M_next()) 1164 { 1165 if (this->_M_equals(__k, __code, __p)) 1166 return __prev_p; 1167 if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n) 1168 break; 1169 __prev_p = __p; 1170 } 1171 return nullptr; 1172 } 1173 1174 template<typename _Key, typename _Value, 1175 typename _Alloc, typename _ExtractKey, typename _Equal, 1176 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1177 typename _Traits> 1178 void 1179 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1180 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1181 _M_insert_bucket_begin(size_type __bkt, __node_type* __node) 1182 { 1183 if (_M_buckets[__bkt]) 1184 { 1185 // Bucket is not empty, we just need to insert the new node 1186 // after the bucket before begin. 1187 __node->_M_nxt = _M_buckets[__bkt]->_M_nxt; 1188 _M_buckets[__bkt]->_M_nxt = __node; 1189 } 1190 else 1191 { 1192 // The bucket is empty, the new node is inserted at the 1193 // beginning of the singly-linked list and the bucket will 1194 // contain _M_before_begin pointer. 1195 __node->_M_nxt = _M_before_begin()._M_nxt; 1196 _M_before_begin()._M_nxt = __node; 1197 if (__node->_M_nxt) 1198 // We must update former begin bucket that is pointing to 1199 // _M_before_begin. 1200 _M_buckets[_M_bucket_index(__node->_M_next())] = __node; 1201 _M_buckets[__bkt] = &_M_before_begin(); 1202 } 1203 } 1204 1205 template<typename _Key, typename _Value, 1206 typename _Alloc, typename _ExtractKey, typename _Equal, 1207 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1208 typename _Traits> 1209 void 1210 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1211 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1212 _M_remove_bucket_begin(size_type __bkt, __node_type* __next, 1213 size_type __next_bkt) 1214 { 1215 if (!__next || __next_bkt != __bkt) 1216 { 1217 // Bucket is now empty 1218 // First update next bucket if any 1219 if (__next) 1220 _M_buckets[__next_bkt] = _M_buckets[__bkt]; 1221 1222 // Second update before begin node if necessary 1223 if (&_M_before_begin() == _M_buckets[__bkt]) 1224 _M_before_begin()._M_nxt = __next; 1225 _M_buckets[__bkt] = nullptr; 1226 } 1227 } 1228 1229 template<typename _Key, typename _Value, 1230 typename _Alloc, typename _ExtractKey, typename _Equal, 1231 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1232 typename _Traits> 1233 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, 1234 _Equal, _H1, _H2, _Hash, _RehashPolicy, 1235 _Traits>::__node_base* 1236 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1237 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1238 _M_get_previous_node(size_type __bkt, __node_base* __n) 1239 { 1240 __node_base* __prev_n = _M_buckets[__bkt]; 1241 while (__prev_n->_M_nxt != __n) 1242 __prev_n = __prev_n->_M_nxt; 1243 return __prev_n; 1244 } 1245 1246 template<typename _Key, typename _Value, 1247 typename _Alloc, typename _ExtractKey, typename _Equal, 1248 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1249 typename _Traits> 1250 template<typename... _Args> 1251 std::pair<typename _Hashtable<_Key, _Value, _Alloc, 1252 _ExtractKey, _Equal, _H1, 1253 _H2, _Hash, _RehashPolicy, 1254 _Traits>::iterator, bool> 1255 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1256 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1257 _M_emplace(std::true_type, _Args&&... __args) 1258 { 1259 // First build the node to get access to the hash code 1260 __node_type* __node = _M_allocate_node(std::forward<_Args>(__args)...); 1261 const key_type& __k = this->_M_extract()(__node->_M_v); 1262 __hash_code __code; 1263 __try 1264 { 1265 __code = this->_M_hash_code(__k); 1266 } 1267 __catch(...) 1268 { 1269 _M_deallocate_node(__node); 1270 __throw_exception_again; 1271 } 1272 1273 size_type __bkt = _M_bucket_index(__k, __code); 1274 if (__node_type* __p = _M_find_node(__bkt, __k, __code)) 1275 { 1276 // There is already an equivalent node, no insertion 1277 _M_deallocate_node(__node); 1278 return std::make_pair(iterator(__p), false); 1279 } 1280 1281 // Insert the node 1282 return std::make_pair(_M_insert_unique_node(__bkt, __code, __node), 1283 true); 1284 } 1285 1286 template<typename _Key, typename _Value, 1287 typename _Alloc, typename _ExtractKey, typename _Equal, 1288 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1289 typename _Traits> 1290 template<typename... _Args> 1291 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1292 _H1, _H2, _Hash, _RehashPolicy, 1293 _Traits>::iterator 1294 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1295 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1296 _M_emplace(std::false_type, _Args&&... __args) 1297 { 1298 // First build the node to get its hash code. 1299 __node_type* __node = _M_allocate_node(std::forward<_Args>(__args)...); 1300 1301 __hash_code __code; 1302 __try 1303 { 1304 __code = this->_M_hash_code(this->_M_extract()(__node->_M_v)); 1305 } 1306 __catch(...) 1307 { 1308 _M_deallocate_node(__node); 1309 __throw_exception_again; 1310 } 1311 1312 return _M_insert_multi_node(__code, __node); 1313 } 1314 1315 template<typename _Key, typename _Value, 1316 typename _Alloc, typename _ExtractKey, typename _Equal, 1317 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1318 typename _Traits> 1319 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1320 _H1, _H2, _Hash, _RehashPolicy, 1321 _Traits>::iterator 1322 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1323 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1324 _M_insert_unique_node(size_type __bkt, __hash_code __code, 1325 __node_type* __node) 1326 { 1327 const __rehash_state& __saved_state = _M_rehash_policy._M_state(); 1328 std::pair<bool, std::size_t> __do_rehash 1329 = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 1); 1330 1331 __try 1332 { 1333 if (__do_rehash.first) 1334 { 1335 _M_rehash(__do_rehash.second, __saved_state); 1336 __bkt = _M_bucket_index(this->_M_extract()(__node->_M_v), __code); 1337 } 1338 1339 this->_M_store_code(__node, __code); 1340 1341 // Always insert at the begining of the bucket. 1342 _M_insert_bucket_begin(__bkt, __node); 1343 ++_M_element_count; 1344 return iterator(__node); 1345 } 1346 __catch(...) 1347 { 1348 _M_deallocate_node(__node); 1349 __throw_exception_again; 1350 } 1351 } 1352 1353 // Insert node, in bucket bkt if no rehash (assumes no element with its key 1354 // already present). Take ownership of the node, deallocate it on exception. 1355 template<typename _Key, typename _Value, 1356 typename _Alloc, typename _ExtractKey, typename _Equal, 1357 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1358 typename _Traits> 1359 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1360 _H1, _H2, _Hash, _RehashPolicy, 1361 _Traits>::iterator 1362 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1363 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1364 _M_insert_multi_node(__hash_code __code, __node_type* __node) 1365 { 1366 const __rehash_state& __saved_state = _M_rehash_policy._M_state(); 1367 std::pair<bool, std::size_t> __do_rehash 1368 = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 1); 1369 1370 __try 1371 { 1372 if (__do_rehash.first) 1373 _M_rehash(__do_rehash.second, __saved_state); 1374 1375 this->_M_store_code(__node, __code); 1376 const key_type& __k = this->_M_extract()(__node->_M_v); 1377 size_type __bkt = _M_bucket_index(__k, __code); 1378 1379 // Find the node before an equivalent one. 1380 __node_base* __prev = _M_find_before_node(__bkt, __k, __code); 1381 if (__prev) 1382 { 1383 // Insert after the node before the equivalent one. 1384 __node->_M_nxt = __prev->_M_nxt; 1385 __prev->_M_nxt = __node; 1386 } 1387 else 1388 // The inserted node has no equivalent in the 1389 // hashtable. We must insert the new node at the 1390 // beginning of the bucket to preserve equivalent 1391 // elements' relative positions. 1392 _M_insert_bucket_begin(__bkt, __node); 1393 ++_M_element_count; 1394 return iterator(__node); 1395 } 1396 __catch(...) 1397 { 1398 _M_deallocate_node(__node); 1399 __throw_exception_again; 1400 } 1401 } 1402 1403 // Insert v if no element with its key is already present. 1404 template<typename _Key, typename _Value, 1405 typename _Alloc, typename _ExtractKey, typename _Equal, 1406 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1407 typename _Traits> 1408 template<typename _Arg> 1409 std::pair<typename _Hashtable<_Key, _Value, _Alloc, 1410 _ExtractKey, _Equal, _H1, 1411 _H2, _Hash, _RehashPolicy, 1412 _Traits>::iterator, bool> 1413 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1414 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1415 _M_insert(_Arg&& __v, std::true_type) 1416 { 1417 const key_type& __k = this->_M_extract()(__v); 1418 __hash_code __code = this->_M_hash_code(__k); 1419 size_type __bkt = _M_bucket_index(__k, __code); 1420 1421 __node_type* __n = _M_find_node(__bkt, __k, __code); 1422 if (__n) 1423 return std::make_pair(iterator(__n), false); 1424 1425 __n = _M_allocate_node(std::forward<_Arg>(__v)); 1426 return std::make_pair(_M_insert_unique_node(__bkt, __code, __n), true); 1427 } 1428 1429 // Insert v unconditionally. 1430 template<typename _Key, typename _Value, 1431 typename _Alloc, typename _ExtractKey, typename _Equal, 1432 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1433 typename _Traits> 1434 template<typename _Arg> 1435 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1436 _H1, _H2, _Hash, _RehashPolicy, 1437 _Traits>::iterator 1438 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1439 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1440 _M_insert(_Arg&& __v, std::false_type) 1441 { 1442 // First compute the hash code so that we don't do anything if it 1443 // throws. 1444 __hash_code __code = this->_M_hash_code(this->_M_extract()(__v)); 1445 1446 // Second allocate new node so that we don't rehash if it throws. 1447 __node_type* __node = _M_allocate_node(std::forward<_Arg>(__v)); 1448 1449 return _M_insert_multi_node(__code, __node); 1450 } 1451 1452 template<typename _Key, typename _Value, 1453 typename _Alloc, typename _ExtractKey, typename _Equal, 1454 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1455 typename _Traits> 1456 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1457 _H1, _H2, _Hash, _RehashPolicy, 1458 _Traits>::iterator 1459 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1460 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1461 erase(const_iterator __it) 1462 { 1463 __node_type* __n = __it._M_cur; 1464 std::size_t __bkt = _M_bucket_index(__n); 1465 1466 // Look for previous node to unlink it from the erased one, this 1467 // is why we need buckets to contain the before begin to make 1468 // this search fast. 1469 __node_base* __prev_n = _M_get_previous_node(__bkt, __n); 1470 return _M_erase(__bkt, __prev_n, __n); 1471 } 1472 1473 template<typename _Key, typename _Value, 1474 typename _Alloc, typename _ExtractKey, typename _Equal, 1475 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1476 typename _Traits> 1477 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1478 _H1, _H2, _Hash, _RehashPolicy, 1479 _Traits>::iterator 1480 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1481 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1482 _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n) 1483 { 1484 if (__prev_n == _M_buckets[__bkt]) 1485 _M_remove_bucket_begin(__bkt, __n->_M_next(), 1486 __n->_M_nxt ? _M_bucket_index(__n->_M_next()) : 0); 1487 else if (__n->_M_nxt) 1488 { 1489 size_type __next_bkt = _M_bucket_index(__n->_M_next()); 1490 if (__next_bkt != __bkt) 1491 _M_buckets[__next_bkt] = __prev_n; 1492 } 1493 1494 __prev_n->_M_nxt = __n->_M_nxt; 1495 iterator __result(__n->_M_next()); 1496 _M_deallocate_node(__n); 1497 --_M_element_count; 1498 1499 return __result; 1500 } 1501 1502 template<typename _Key, typename _Value, 1503 typename _Alloc, typename _ExtractKey, typename _Equal, 1504 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1505 typename _Traits> 1506 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1507 _H1, _H2, _Hash, _RehashPolicy, 1508 _Traits>::size_type 1509 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1510 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1511 _M_erase(std::true_type, const key_type& __k) 1512 { 1513 __hash_code __code = this->_M_hash_code(__k); 1514 std::size_t __bkt = _M_bucket_index(__k, __code); 1515 1516 // Look for the node before the first matching node. 1517 __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code); 1518 if (!__prev_n) 1519 return 0; 1520 1521 // We found a matching node, erase it. 1522 __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt); 1523 _M_erase(__bkt, __prev_n, __n); 1524 return 1; 1525 } 1526 1527 template<typename _Key, typename _Value, 1528 typename _Alloc, typename _ExtractKey, typename _Equal, 1529 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1530 typename _Traits> 1531 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1532 _H1, _H2, _Hash, _RehashPolicy, 1533 _Traits>::size_type 1534 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1535 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1536 _M_erase(std::false_type, const key_type& __k) 1537 { 1538 __hash_code __code = this->_M_hash_code(__k); 1539 std::size_t __bkt = _M_bucket_index(__k, __code); 1540 1541 // Look for the node before the first matching node. 1542 __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code); 1543 if (!__prev_n) 1544 return 0; 1545 1546 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1547 // 526. Is it undefined if a function in the standard changes 1548 // in parameters? 1549 // We use one loop to find all matching nodes and another to deallocate 1550 // them so that the key stays valid during the first loop. It might be 1551 // invalidated indirectly when destroying nodes. 1552 __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt); 1553 __node_type* __n_last = __n; 1554 std::size_t __n_last_bkt = __bkt; 1555 do 1556 { 1557 __n_last = __n_last->_M_next(); 1558 if (!__n_last) 1559 break; 1560 __n_last_bkt = _M_bucket_index(__n_last); 1561 } 1562 while (__n_last_bkt == __bkt && this->_M_equals(__k, __code, __n_last)); 1563 1564 // Deallocate nodes. 1565 size_type __result = 0; 1566 do 1567 { 1568 __node_type* __p = __n->_M_next(); 1569 _M_deallocate_node(__n); 1570 __n = __p; 1571 ++__result; 1572 --_M_element_count; 1573 } 1574 while (__n != __n_last); 1575 1576 if (__prev_n == _M_buckets[__bkt]) 1577 _M_remove_bucket_begin(__bkt, __n_last, __n_last_bkt); 1578 else if (__n_last && __n_last_bkt != __bkt) 1579 _M_buckets[__n_last_bkt] = __prev_n; 1580 __prev_n->_M_nxt = __n_last; 1581 return __result; 1582 } 1583 1584 template<typename _Key, typename _Value, 1585 typename _Alloc, typename _ExtractKey, typename _Equal, 1586 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1587 typename _Traits> 1588 typename _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1589 _H1, _H2, _Hash, _RehashPolicy, 1590 _Traits>::iterator 1591 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1592 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1593 erase(const_iterator __first, const_iterator __last) 1594 { 1595 __node_type* __n = __first._M_cur; 1596 __node_type* __last_n = __last._M_cur; 1597 if (__n == __last_n) 1598 return iterator(__n); 1599 1600 std::size_t __bkt = _M_bucket_index(__n); 1601 1602 __node_base* __prev_n = _M_get_previous_node(__bkt, __n); 1603 bool __is_bucket_begin = __n == _M_bucket_begin(__bkt); 1604 std::size_t __n_bkt = __bkt; 1605 for (;;) 1606 { 1607 do 1608 { 1609 __node_type* __tmp = __n; 1610 __n = __n->_M_next(); 1611 _M_deallocate_node(__tmp); 1612 --_M_element_count; 1613 if (!__n) 1614 break; 1615 __n_bkt = _M_bucket_index(__n); 1616 } 1617 while (__n != __last_n && __n_bkt == __bkt); 1618 if (__is_bucket_begin) 1619 _M_remove_bucket_begin(__bkt, __n, __n_bkt); 1620 if (__n == __last_n) 1621 break; 1622 __is_bucket_begin = true; 1623 __bkt = __n_bkt; 1624 } 1625 1626 if (__n && (__n_bkt != __bkt || __is_bucket_begin)) 1627 _M_buckets[__n_bkt] = __prev_n; 1628 __prev_n->_M_nxt = __n; 1629 return iterator(__n); 1630 } 1631 1632 template<typename _Key, typename _Value, 1633 typename _Alloc, typename _ExtractKey, typename _Equal, 1634 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1635 typename _Traits> 1636 void 1637 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1638 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1639 clear() noexcept 1640 { 1641 _M_deallocate_nodes(_M_begin()); 1642 __builtin_memset(_M_buckets, 0, _M_bucket_count * sizeof(__bucket_type)); 1643 _M_element_count = 0; 1644 _M_before_begin()._M_nxt = nullptr; 1645 } 1646 1647 template<typename _Key, typename _Value, 1648 typename _Alloc, typename _ExtractKey, typename _Equal, 1649 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1650 typename _Traits> 1651 void 1652 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1653 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1654 rehash(size_type __n) 1655 { 1656 const __rehash_state& __saved_state = _M_rehash_policy._M_state(); 1657 std::size_t __buckets 1658 = std::max(_M_rehash_policy._M_bkt_for_elements(_M_element_count + 1), 1659 __n); 1660 __buckets = _M_rehash_policy._M_next_bkt(__buckets); 1661 1662 if (__buckets != _M_bucket_count) 1663 _M_rehash(__buckets, __saved_state); 1664 else 1665 // No rehash, restore previous state to keep a consistent state. 1666 _M_rehash_policy._M_reset(__saved_state); 1667 } 1668 1669 template<typename _Key, typename _Value, 1670 typename _Alloc, typename _ExtractKey, typename _Equal, 1671 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1672 typename _Traits> 1673 void 1674 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1675 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1676 _M_rehash(size_type __n, const __rehash_state& __state) 1677 { 1678 __try 1679 { 1680 _M_rehash_aux(__n, __unique_keys()); 1681 } 1682 __catch(...) 1683 { 1684 // A failure here means that buckets allocation failed. We only 1685 // have to restore hash policy previous state. 1686 _M_rehash_policy._M_reset(__state); 1687 __throw_exception_again; 1688 } 1689 } 1690 1691 // Rehash when there is no equivalent elements. 1692 template<typename _Key, typename _Value, 1693 typename _Alloc, typename _ExtractKey, typename _Equal, 1694 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1695 typename _Traits> 1696 void 1697 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1698 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1699 _M_rehash_aux(size_type __n, std::true_type) 1700 { 1701 __bucket_type* __new_buckets = _M_allocate_buckets(__n); 1702 __node_type* __p = _M_begin(); 1703 _M_before_begin()._M_nxt = nullptr; 1704 std::size_t __bbegin_bkt = 0; 1705 while (__p) 1706 { 1707 __node_type* __next = __p->_M_next(); 1708 std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n); 1709 if (!__new_buckets[__bkt]) 1710 { 1711 __p->_M_nxt = _M_before_begin()._M_nxt; 1712 _M_before_begin()._M_nxt = __p; 1713 __new_buckets[__bkt] = &_M_before_begin(); 1714 if (__p->_M_nxt) 1715 __new_buckets[__bbegin_bkt] = __p; 1716 __bbegin_bkt = __bkt; 1717 } 1718 else 1719 { 1720 __p->_M_nxt = __new_buckets[__bkt]->_M_nxt; 1721 __new_buckets[__bkt]->_M_nxt = __p; 1722 } 1723 __p = __next; 1724 } 1725 _M_deallocate_buckets(_M_buckets, _M_bucket_count); 1726 _M_bucket_count = __n; 1727 _M_buckets = __new_buckets; 1728 } 1729 1730 // Rehash when there can be equivalent elements, preserve their relative 1731 // order. 1732 template<typename _Key, typename _Value, 1733 typename _Alloc, typename _ExtractKey, typename _Equal, 1734 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1735 typename _Traits> 1736 void 1737 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1738 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1739 _M_rehash_aux(size_type __n, std::false_type) 1740 { 1741 __bucket_type* __new_buckets = _M_allocate_buckets(__n); 1742 1743 __node_type* __p = _M_begin(); 1744 _M_before_begin()._M_nxt = nullptr; 1745 std::size_t __bbegin_bkt = 0; 1746 std::size_t __prev_bkt = 0; 1747 __node_type* __prev_p = nullptr; 1748 bool __check_bucket = false; 1749 1750 while (__p) 1751 { 1752 __node_type* __next = __p->_M_next(); 1753 std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n); 1754 1755 if (__prev_p && __prev_bkt == __bkt) 1756 { 1757 // Previous insert was already in this bucket, we insert after 1758 // the previously inserted one to preserve equivalent elements 1759 // relative order. 1760 __p->_M_nxt = __prev_p->_M_nxt; 1761 __prev_p->_M_nxt = __p; 1762 1763 // Inserting after a node in a bucket require to check that we 1764 // haven't change the bucket last node, in this case next 1765 // bucket containing its before begin node must be updated. We 1766 // schedule a check as soon as we move out of the sequence of 1767 // equivalent nodes to limit the number of checks. 1768 __check_bucket = true; 1769 } 1770 else 1771 { 1772 if (__check_bucket) 1773 { 1774 // Check if we shall update the next bucket because of 1775 // insertions into __prev_bkt bucket. 1776 if (__prev_p->_M_nxt) 1777 { 1778 std::size_t __next_bkt 1779 = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), 1780 __n); 1781 if (__next_bkt != __prev_bkt) 1782 __new_buckets[__next_bkt] = __prev_p; 1783 } 1784 __check_bucket = false; 1785 } 1786 1787 if (!__new_buckets[__bkt]) 1788 { 1789 __p->_M_nxt = _M_before_begin()._M_nxt; 1790 _M_before_begin()._M_nxt = __p; 1791 __new_buckets[__bkt] = &_M_before_begin(); 1792 if (__p->_M_nxt) 1793 __new_buckets[__bbegin_bkt] = __p; 1794 __bbegin_bkt = __bkt; 1795 } 1796 else 1797 { 1798 __p->_M_nxt = __new_buckets[__bkt]->_M_nxt; 1799 __new_buckets[__bkt]->_M_nxt = __p; 1800 } 1801 } 1802 __prev_p = __p; 1803 __prev_bkt = __bkt; 1804 __p = __next; 1805 } 1806 1807 if (__check_bucket && __prev_p->_M_nxt) 1808 { 1809 std::size_t __next_bkt 1810 = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), __n); 1811 if (__next_bkt != __prev_bkt) 1812 __new_buckets[__next_bkt] = __prev_p; 1813 } 1814 1815 _M_deallocate_buckets(_M_buckets, _M_bucket_count); 1816 _M_bucket_count = __n; 1817 _M_buckets = __new_buckets; 1818 } 1819 1820_GLIBCXX_END_NAMESPACE_VERSION 1821} // namespace std 1822 1823#endif // _HASHTABLE_H 1824