1263970Sdes// hashtable.h header -*- C++ -*- 257429Smarkm 357429Smarkm// Copyright (C) 2007-2015 Free Software Foundation, Inc. 457429Smarkm// 557429Smarkm// This file is part of the GNU ISO C++ Library. This library is free 657429Smarkm// software; you can redistribute it and/or modify it under the 757429Smarkm// terms of the GNU General Public License as published by the 876259Sgreen// Free Software Foundation; either version 3, or (at your option) 965668Skris// any later version. 1065668Skris 1165668Skris// This library is distributed in the hope that it will be useful, 1265668Skris// but WITHOUT ANY WARRANTY; without even the implied warranty of 1365668Skris// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1457429Smarkm// GNU General Public License for more details. 1557429Smarkm 1657429Smarkm// Under Section 7 of GPL version 3, you are granted additional 1757429Smarkm// permissions described in the GCC Runtime Library Exception, version 18162852Sdes// 3.1, as published by the Free Software Foundation. 19162852Sdes 20162852Sdes// You should have received a copy of the GNU General Public License and 21162852Sdes// a copy of the GCC Runtime Library Exception along with this program; 22162852Sdes// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23162852Sdes// <http://www.gnu.org/licenses/>. 2476259Sgreen 2576259Sgreen/** @file bits/hashtable.h 2657429Smarkm * This is an internal header file, included by other library headers. 2757429Smarkm * Do not attempt to use it directly. @headername{unordered_map, unordered_set} 2857429Smarkm */ 2957429Smarkm 3076259Sgreen#ifndef _HASHTABLE_H 3176259Sgreen#define _HASHTABLE_H 1 3276259Sgreen 3376259Sgreen#pragma GCC system_header 3476259Sgreen 3557429Smarkm#include <bits/hashtable_policy.h> 36263970Sdes 3757429Smarkmnamespace std _GLIBCXX_VISIBILITY(default) 3857429Smarkm{ 3957429Smarkm_GLIBCXX_BEGIN_NAMESPACE_VERSION 4057429Smarkm 41162852Sdes template<typename _Tp, typename _Hash> 4257429Smarkm using __cache_default 43162852Sdes = __not_<__and_<// Do not cache for fast hasher. 44162852Sdes __is_fast_hash<_Hash>, 45162852Sdes // Mandatory to have erase not throwing. 46162852Sdes __detail::__is_noexcept_hash<_Tp, _Hash>>>; 47162852Sdes 48162852Sdes /** 49162852Sdes * Primary class template _Hashtable. 50162852Sdes * 51263970Sdes * @ingroup hashtable-detail 52263970Sdes * 53162852Sdes * @tparam _Value CopyConstructible type. 54162852Sdes * 55162852Sdes * @tparam _Key CopyConstructible type. 56162852Sdes * 57162852Sdes * @tparam _Alloc An allocator type 58162852Sdes * ([lib.allocator.requirements]) whose _Alloc::value_type is 5957429Smarkm * _Value. As a conforming extension, we allow for 60162852Sdes * _Alloc::value_type != _Value. 6157429Smarkm * 6276259Sgreen * @tparam _ExtractKey Function object that takes an object of type 6376259Sgreen * _Value and returns a value of type _Key. 64162852Sdes * 65162852Sdes * @tparam _Equal Function object that takes two objects of type k 6657429Smarkm * and returns a bool-like value that is true if the two objects 6776259Sgreen * are considered equal. 6876259Sgreen * 6976259Sgreen * @tparam _H1 The hash function. A unary function object with 7057429Smarkm * argument type _Key and result type size_t. Return values should 71263970Sdes * be distributed over the entire range [0, numeric_limits<size_t>:::max()]. 72263970Sdes * 7357429Smarkm * @tparam _H2 The range-hashing function (in the terminology of 7457429Smarkm * Tavori and Dreizin). A binary function object whose argument 7557429Smarkm * types and result type are all size_t. Given arguments r and N, 7657429Smarkm * the return value is in the range [0, N). 7757429Smarkm * 7857429Smarkm * @tparam _Hash The ranged hash function (Tavori and Dreizin). A 7992555Sdes * binary function whose argument types are _Key and size_t and 8076259Sgreen * whose result type is size_t. Given arguments k and N, the 8157429Smarkm * return value is in the range [0, N). Default: hash(k, N) = 8292555Sdes * h2(h1(k), N). If _Hash is anything other than the default, _H1 8376259Sgreen * and _H2 are ignored. 8457429Smarkm * 8557429Smarkm * @tparam _RehashPolicy Policy class with three members, all of 8657429Smarkm * which govern the bucket count. _M_next_bkt(n) returns a bucket 87162852Sdes * count no smaller than n. _M_bkt_for_elements(n) returns a 88162852Sdes * bucket count appropriate for an element count of n. 89162852Sdes * _M_need_rehash(n_bkt, n_elt, n_ins) determines whether, if the 90162852Sdes * current bucket count is n_bkt and the current element count is 91162852Sdes * n_elt, we need to increase the bucket count. If so, returns 92162852Sdes * make_pair(true, n), where n is the new bucket count. If not, 93162852Sdes * returns make_pair(false, <anything>) 94162852Sdes * 95162852Sdes * @tparam _Traits Compile-time class with three boolean 96162852Sdes * std::integral_constant members: __cache_hash_code, __constant_iterators, 97162852Sdes * __unique_keys. 98162852Sdes * 99162852Sdes * Each _Hashtable data structure has: 100162852Sdes * 101162852Sdes * - _Bucket[] _M_buckets 102162852Sdes * - _Hash_node_base _M_before_begin 103 * - size_type _M_bucket_count 104 * - size_type _M_element_count 105 * 106 * with _Bucket being _Hash_node* and _Hash_node containing: 107 * 108 * - _Hash_node* _M_next 109 * - Tp _M_value 110 * - size_t _M_hash_code if cache_hash_code is true 111 * 112 * In terms of Standard containers the hashtable is like the aggregation of: 113 * 114 * - std::forward_list<_Node> containing the elements 115 * - std::vector<std::forward_list<_Node>::iterator> representing the buckets 116 * 117 * The non-empty buckets contain the node before the first node in the 118 * bucket. This design makes it possible to implement something like a 119 * std::forward_list::insert_after on container insertion and 120 * std::forward_list::erase_after on container erase 121 * calls. _M_before_begin is equivalent to 122 * std::forward_list::before_begin. Empty buckets contain 123 * nullptr. Note that one of the non-empty buckets contains 124 * &_M_before_begin which is not a dereferenceable node so the 125 * node pointer in a bucket shall never be dereferenced, only its 126 * next node can be. 127 * 128 * Walking through a bucket's nodes requires a check on the hash code to 129 * see if each node is still in the bucket. Such a design assumes a 130 * quite efficient hash functor and is one of the reasons it is 131 * highly advisable to set __cache_hash_code to true. 132 * 133 * The container iterators are simply built from nodes. This way 134 * incrementing the iterator is perfectly efficient independent of 135 * how many empty buckets there are in the container. 136 * 137 * On insert we compute the element's hash code and use it to find the 138 * bucket index. If the element must be inserted in an empty bucket 139 * we add it at the beginning of the singly linked list and make the 140 * bucket point to _M_before_begin. The bucket that used to point to 141 * _M_before_begin, if any, is updated to point to its new before 142 * begin node. 143 * 144 * On erase, the simple iterator design requires using the hash 145 * functor to get the index of the bucket to update. For this 146 * reason, when __cache_hash_code is set to false the hash functor must 147 * not throw and this is enforced by a static assertion. 148 * 149 * Functionality is implemented by decomposition into base classes, 150 * where the derived _Hashtable class is used in _Map_base, 151 * _Insert, _Rehash_base, and _Equality base classes to access the 152 * "this" pointer. _Hashtable_base is used in the base classes as a 153 * non-recursive, fully-completed-type so that detailed nested type 154 * information, such as iterator type and node type, can be 155 * used. This is similar to the "Curiously Recurring Template 156 * Pattern" (CRTP) technique, but uses a reconstructed, not 157 * explicitly passed, template pattern. 158 * 159 * Base class templates are: 160 * - __detail::_Hashtable_base 161 * - __detail::_Map_base 162 * - __detail::_Insert 163 * - __detail::_Rehash_base 164 * - __detail::_Equality 165 */ 166 template<typename _Key, typename _Value, typename _Alloc, 167 typename _ExtractKey, typename _Equal, 168 typename _H1, typename _H2, typename _Hash, 169 typename _RehashPolicy, typename _Traits> 170 class _Hashtable 171 : public __detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, 172 _H1, _H2, _Hash, _Traits>, 173 public __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 174 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 175 public __detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, 176 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 177 public __detail::_Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 178 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 179 public __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 180 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 181 private __detail::_Hashtable_alloc< 182 typename __alloctr_rebind<_Alloc, 183 __detail::_Hash_node<_Value, 184 _Traits::__hash_cached::value> >::__type> 185 { 186 using __traits_type = _Traits; 187 using __hash_cached = typename __traits_type::__hash_cached; 188 using __node_type = __detail::_Hash_node<_Value, __hash_cached::value>; 189 using __node_alloc_type = 190 typename __alloctr_rebind<_Alloc, __node_type>::__type; 191 192 using __hashtable_alloc = __detail::_Hashtable_alloc<__node_alloc_type>; 193 194 using __value_alloc_traits = 195 typename __hashtable_alloc::__value_alloc_traits; 196 using __node_alloc_traits = 197 typename __hashtable_alloc::__node_alloc_traits; 198 using __node_base = typename __hashtable_alloc::__node_base; 199 using __bucket_type = typename __hashtable_alloc::__bucket_type; 200 201 public: 202 typedef _Key key_type; 203 typedef _Value value_type; 204 typedef _Alloc allocator_type; 205 typedef _Equal key_equal; 206 207 // mapped_type, if present, comes from _Map_base. 208 // hasher, if present, comes from _Hash_code_base/_Hashtable_base. 209 typedef typename __value_alloc_traits::pointer pointer; 210 typedef typename __value_alloc_traits::const_pointer const_pointer; 211 typedef value_type& reference; 212 typedef const value_type& const_reference; 213 214 private: 215 using __rehash_type = _RehashPolicy; 216 using __rehash_state = typename __rehash_type::_State; 217 218 using __constant_iterators = typename __traits_type::__constant_iterators; 219 using __unique_keys = typename __traits_type::__unique_keys; 220 221 using __key_extract = typename std::conditional< 222 __constant_iterators::value, 223 __detail::_Identity, 224 __detail::_Select1st>::type; 225 226 using __hashtable_base = __detail:: 227 _Hashtable_base<_Key, _Value, _ExtractKey, 228 _Equal, _H1, _H2, _Hash, _Traits>; 229 230 using __hash_code_base = typename __hashtable_base::__hash_code_base; 231 using __hash_code = typename __hashtable_base::__hash_code; 232 using __ireturn_type = typename __hashtable_base::__ireturn_type; 233 234 using __map_base = __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, 235 _Equal, _H1, _H2, _Hash, 236 _RehashPolicy, _Traits>; 237 238 using __rehash_base = __detail::_Rehash_base<_Key, _Value, _Alloc, 239 _ExtractKey, _Equal, 240 _H1, _H2, _Hash, 241 _RehashPolicy, _Traits>; 242 243 using __eq_base = __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, 244 _Equal, _H1, _H2, _Hash, 245 _RehashPolicy, _Traits>; 246 247 using __reuse_or_alloc_node_type = 248 __detail::_ReuseOrAllocNode<__node_alloc_type>; 249 250 // Metaprogramming for picking apart hash caching. 251 template<typename _Cond> 252 using __if_hash_cached = __or_<__not_<__hash_cached>, _Cond>; 253 254 template<typename _Cond> 255 using __if_hash_not_cached = __or_<__hash_cached, _Cond>; 256 257 // Compile-time diagnostics. 258 259 // _Hash_code_base has everything protected, so use this derived type to 260 // access it. 261 struct __hash_code_base_access : __hash_code_base 262 { using __hash_code_base::_M_bucket_index; }; 263 264 // Getting a bucket index from a node shall not throw because it is used 265 // in methods (erase, swap...) that shall not throw. 266 static_assert(noexcept(declval<const __hash_code_base_access&>() 267 ._M_bucket_index((const __node_type*)nullptr, 268 (std::size_t)0)), 269 "Cache the hash code or qualify your functors involved" 270 " in hash code and bucket index computation with noexcept"); 271 272 // Following two static assertions are necessary to guarantee 273 // that local_iterator will be default constructible. 274 275 // When hash codes are cached local iterator inherits from H2 functor 276 // which must then be default constructible. 277 static_assert(__if_hash_cached<is_default_constructible<_H2>>::value, 278 "Functor used to map hash code to bucket index" 279 " must be default constructible"); 280 281 template<typename _Keya, typename _Valuea, typename _Alloca, 282 typename _ExtractKeya, typename _Equala, 283 typename _H1a, typename _H2a, typename _Hasha, 284 typename _RehashPolicya, typename _Traitsa, 285 bool _Unique_keysa> 286 friend struct __detail::_Map_base; 287 288 template<typename _Keya, typename _Valuea, typename _Alloca, 289 typename _ExtractKeya, typename _Equala, 290 typename _H1a, typename _H2a, typename _Hasha, 291 typename _RehashPolicya, typename _Traitsa> 292 friend struct __detail::_Insert_base; 293 294 template<typename _Keya, typename _Valuea, typename _Alloca, 295 typename _ExtractKeya, typename _Equala, 296 typename _H1a, typename _H2a, typename _Hasha, 297 typename _RehashPolicya, typename _Traitsa, 298 bool _Constant_iteratorsa, bool _Unique_keysa> 299 friend struct __detail::_Insert; 300 301 public: 302 using size_type = typename __hashtable_base::size_type; 303 using difference_type = typename __hashtable_base::difference_type; 304 305 using iterator = typename __hashtable_base::iterator; 306 using const_iterator = typename __hashtable_base::const_iterator; 307 308 using local_iterator = typename __hashtable_base::local_iterator; 309 using const_local_iterator = typename __hashtable_base:: 310 const_local_iterator; 311 312 private: 313 __bucket_type* _M_buckets = &_M_single_bucket; 314 size_type _M_bucket_count = 1; 315 __node_base _M_before_begin; 316 size_type _M_element_count = 0; 317 _RehashPolicy _M_rehash_policy; 318 319 // A single bucket used when only need for 1 bucket. Especially 320 // interesting in move semantic to leave hashtable with only 1 buckets 321 // which is not allocated so that we can have those operations noexcept 322 // qualified. 323 // Note that we can't leave hashtable with 0 bucket without adding 324 // numerous checks in the code to avoid 0 modulus. 325 __bucket_type _M_single_bucket = nullptr; 326 327 bool 328 _M_uses_single_bucket(__bucket_type* __bkts) const 329 { return __builtin_expect(__bkts == &_M_single_bucket, false); } 330 331 bool 332 _M_uses_single_bucket() const 333 { return _M_uses_single_bucket(_M_buckets); } 334 335 __hashtable_alloc& 336 _M_base_alloc() { return *this; } 337 338 __bucket_type* 339 _M_allocate_buckets(size_type __n) 340 { 341 if (__builtin_expect(__n == 1, false)) 342 { 343 _M_single_bucket = nullptr; 344 return &_M_single_bucket; 345 } 346 347 return __hashtable_alloc::_M_allocate_buckets(__n); 348 } 349 350 void 351 _M_deallocate_buckets(__bucket_type* __bkts, size_type __n) 352 { 353 if (_M_uses_single_bucket(__bkts)) 354 return; 355 356 __hashtable_alloc::_M_deallocate_buckets(__bkts, __n); 357 } 358 359 void 360 _M_deallocate_buckets() 361 { _M_deallocate_buckets(_M_buckets, _M_bucket_count); } 362 363 // Gets bucket begin, deals with the fact that non-empty buckets contain 364 // their before begin node. 365 __node_type* 366 _M_bucket_begin(size_type __bkt) const; 367 368 __node_type* 369 _M_begin() const 370 { return static_cast<__node_type*>(_M_before_begin._M_nxt); } 371 372 template<typename _NodeGenerator> 373 void 374 _M_assign(const _Hashtable&, const _NodeGenerator&); 375 376 void 377 _M_move_assign(_Hashtable&&, std::true_type); 378 379 void 380 _M_move_assign(_Hashtable&&, std::false_type); 381 382 void 383 _M_reset() noexcept; 384 385 _Hashtable(const _H1& __h1, const _H2& __h2, const _Hash& __h, 386 const _Equal& __eq, const _ExtractKey& __exk, 387 const allocator_type& __a) 388 : __hashtable_base(__exk, __h1, __h2, __h, __eq), 389 __hashtable_alloc(__node_alloc_type(__a)) 390 { } 391 392 public: 393 // Constructor, destructor, assignment, swap 394 _Hashtable() = default; 395 _Hashtable(size_type __bucket_hint, 396 const _H1&, const _H2&, const _Hash&, 397 const _Equal&, const _ExtractKey&, 398 const allocator_type&); 399 400 template<typename _InputIterator> 401 _Hashtable(_InputIterator __first, _InputIterator __last, 402 size_type __bucket_hint, 403 const _H1&, const _H2&, const _Hash&, 404 const _Equal&, const _ExtractKey&, 405 const allocator_type&); 406 407 _Hashtable(const _Hashtable&); 408 409 _Hashtable(_Hashtable&&) noexcept; 410 411 _Hashtable(const _Hashtable&, const allocator_type&); 412 413 _Hashtable(_Hashtable&&, const allocator_type&); 414 415 // Use delegating constructors. 416 explicit 417 _Hashtable(const allocator_type& __a) 418 : __hashtable_alloc(__node_alloc_type(__a)) 419 { } 420 421 explicit 422 _Hashtable(size_type __n, 423 const _H1& __hf = _H1(), 424 const key_equal& __eql = key_equal(), 425 const allocator_type& __a = allocator_type()) 426 : _Hashtable(__n, __hf, _H2(), _Hash(), __eql, 427 __key_extract(), __a) 428 { } 429 430 template<typename _InputIterator> 431 _Hashtable(_InputIterator __f, _InputIterator __l, 432 size_type __n = 0, 433 const _H1& __hf = _H1(), 434 const key_equal& __eql = key_equal(), 435 const allocator_type& __a = allocator_type()) 436 : _Hashtable(__f, __l, __n, __hf, _H2(), _Hash(), __eql, 437 __key_extract(), __a) 438 { } 439 440 _Hashtable(initializer_list<value_type> __l, 441 size_type __n = 0, 442 const _H1& __hf = _H1(), 443 const key_equal& __eql = key_equal(), 444 const allocator_type& __a = allocator_type()) 445 : _Hashtable(__l.begin(), __l.end(), __n, __hf, _H2(), _Hash(), __eql, 446 __key_extract(), __a) 447 { } 448 449 _Hashtable& 450 operator=(const _Hashtable& __ht); 451 452 _Hashtable& 453 operator=(_Hashtable&& __ht) 454 noexcept(__node_alloc_traits::_S_nothrow_move()) 455 { 456 constexpr bool __move_storage = 457 __node_alloc_traits::_S_propagate_on_move_assign() 458 || __node_alloc_traits::_S_always_equal(); 459 _M_move_assign(std::move(__ht), 460 integral_constant<bool, __move_storage>()); 461 return *this; 462 } 463 464 _Hashtable& 465 operator=(initializer_list<value_type> __l) 466 { 467 __reuse_or_alloc_node_type __roan(_M_begin(), *this); 468 _M_before_begin._M_nxt = nullptr; 469 clear(); 470 this->_M_insert_range(__l.begin(), __l.end(), __roan); 471 return *this; 472 } 473 474 ~_Hashtable() noexcept; 475 476 void 477 swap(_Hashtable&) 478 noexcept(__node_alloc_traits::_S_nothrow_swap()); 479 480 // Basic container operations 481 iterator 482 begin() noexcept 483 { return iterator(_M_begin()); } 484 485 const_iterator 486 begin() const noexcept 487 { return const_iterator(_M_begin()); } 488 489 iterator 490 end() noexcept 491 { return iterator(nullptr); } 492 493 const_iterator 494 end() const noexcept 495 { return const_iterator(nullptr); } 496 497 const_iterator 498 cbegin() const noexcept 499 { return const_iterator(_M_begin()); } 500 501 const_iterator 502 cend() const noexcept 503 { return const_iterator(nullptr); } 504 505 size_type 506 size() const noexcept 507 { return _M_element_count; } 508 509 bool 510 empty() const noexcept 511 { return size() == 0; } 512 513 allocator_type 514 get_allocator() const noexcept 515 { return allocator_type(this->_M_node_allocator()); } 516 517 size_type 518 max_size() const noexcept 519 { return __node_alloc_traits::max_size(this->_M_node_allocator()); } 520 521 // Observers 522 key_equal 523 key_eq() const 524 { return this->_M_eq(); } 525 526 // hash_function, if present, comes from _Hash_code_base. 527 528 // Bucket operations 529 size_type 530 bucket_count() const noexcept 531 { return _M_bucket_count; } 532 533 size_type 534 max_bucket_count() const noexcept 535 { return max_size(); } 536 537 size_type 538 bucket_size(size_type __n) const 539 { return std::distance(begin(__n), end(__n)); } 540 541 size_type 542 bucket(const key_type& __k) const 543 { return _M_bucket_index(__k, this->_M_hash_code(__k)); } 544 545 local_iterator 546 begin(size_type __n) 547 { 548 return local_iterator(*this, _M_bucket_begin(__n), 549 __n, _M_bucket_count); 550 } 551 552 local_iterator 553 end(size_type __n) 554 { return local_iterator(*this, nullptr, __n, _M_bucket_count); } 555 556 const_local_iterator 557 begin(size_type __n) const 558 { 559 return const_local_iterator(*this, _M_bucket_begin(__n), 560 __n, _M_bucket_count); 561 } 562 563 const_local_iterator 564 end(size_type __n) const 565 { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); } 566 567 // DR 691. 568 const_local_iterator 569 cbegin(size_type __n) const 570 { 571 return const_local_iterator(*this, _M_bucket_begin(__n), 572 __n, _M_bucket_count); 573 } 574 575 const_local_iterator 576 cend(size_type __n) const 577 { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); } 578 579 float 580 load_factor() const noexcept 581 { 582 return static_cast<float>(size()) / static_cast<float>(bucket_count()); 583 } 584 585 // max_load_factor, if present, comes from _Rehash_base. 586 587 // Generalization of max_load_factor. Extension, not found in 588 // TR1. Only useful if _RehashPolicy is something other than 589 // the default. 590 const _RehashPolicy& 591 __rehash_policy() const 592 { return _M_rehash_policy; } 593 594 void 595 __rehash_policy(const _RehashPolicy&); 596 597 // Lookup. 598 iterator 599 find(const key_type& __k); 600 601 const_iterator 602 find(const key_type& __k) const; 603 604 size_type 605 count(const key_type& __k) const; 606 607 std::pair<iterator, iterator> 608 equal_range(const key_type& __k); 609 610 std::pair<const_iterator, const_iterator> 611 equal_range(const key_type& __k) const; 612 613 protected: 614 // Bucket index computation helpers. 615 size_type 616 _M_bucket_index(__node_type* __n) const noexcept 617 { return __hash_code_base::_M_bucket_index(__n, _M_bucket_count); } 618 619 size_type 620 _M_bucket_index(const key_type& __k, __hash_code __c) const 621 { return __hash_code_base::_M_bucket_index(__k, __c, _M_bucket_count); } 622 623 // Find and insert helper functions and types 624 // Find the node before the one matching the criteria. 625 __node_base* 626 _M_find_before_node(size_type, const key_type&, __hash_code) const; 627 628 __node_type* 629 _M_find_node(size_type __bkt, const key_type& __key, 630 __hash_code __c) const 631 { 632 __node_base* __before_n = _M_find_before_node(__bkt, __key, __c); 633 if (__before_n) 634 return static_cast<__node_type*>(__before_n->_M_nxt); 635 return nullptr; 636 } 637 638 // Insert a node at the beginning of a bucket. 639 void 640 _M_insert_bucket_begin(size_type, __node_type*); 641 642 // Remove the bucket first node 643 void 644 _M_remove_bucket_begin(size_type __bkt, __node_type* __next_n, 645 size_type __next_bkt); 646 647 // Get the node before __n in the bucket __bkt 648 __node_base* 649 _M_get_previous_node(size_type __bkt, __node_base* __n); 650 651 // Insert node with hash code __code, in bucket bkt if no rehash (assumes 652 // no element with its key already present). Take ownership of the node, 653 // deallocate it on exception. 654 iterator 655 _M_insert_unique_node(size_type __bkt, __hash_code __code, 656 __node_type* __n); 657 658 // Insert node with hash code __code. Take ownership of the node, 659 // deallocate it on exception. 660 iterator 661 _M_insert_multi_node(__node_type* __hint, 662 __hash_code __code, __node_type* __n); 663 664 template<typename... _Args> 665 std::pair<iterator, bool> 666 _M_emplace(std::true_type, _Args&&... __args); 667 668 template<typename... _Args> 669 iterator 670 _M_emplace(std::false_type __uk, _Args&&... __args) 671 { return _M_emplace(cend(), __uk, std::forward<_Args>(__args)...); } 672 673 // Emplace with hint, useless when keys are unique. 674 template<typename... _Args> 675 iterator 676 _M_emplace(const_iterator, std::true_type __uk, _Args&&... __args) 677 { return _M_emplace(__uk, std::forward<_Args>(__args)...).first; } 678 679 template<typename... _Args> 680 iterator 681 _M_emplace(const_iterator, std::false_type, _Args&&... __args); 682 683 template<typename _Arg, typename _NodeGenerator> 684 std::pair<iterator, bool> 685 _M_insert(_Arg&&, const _NodeGenerator&, std::true_type); 686 687 template<typename _Arg, typename _NodeGenerator> 688 iterator 689 _M_insert(_Arg&& __arg, const _NodeGenerator& __node_gen, 690 std::false_type __uk) 691 { 692 return _M_insert(cend(), std::forward<_Arg>(__arg), __node_gen, 693 __uk); 694 } 695 696 // Insert with hint, not used when keys are unique. 697 template<typename _Arg, typename _NodeGenerator> 698 iterator 699 _M_insert(const_iterator, _Arg&& __arg, 700 const _NodeGenerator& __node_gen, std::true_type __uk) 701 { 702 return 703 _M_insert(std::forward<_Arg>(__arg), __node_gen, __uk).first; 704 } 705 706 // Insert with hint when keys are not unique. 707 template<typename _Arg, typename _NodeGenerator> 708 iterator 709 _M_insert(const_iterator, _Arg&&, 710 const _NodeGenerator&, std::false_type); 711 712 size_type 713 _M_erase(std::true_type, const key_type&); 714 715 size_type 716 _M_erase(std::false_type, const key_type&); 717 718 iterator 719 _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n); 720 721 public: 722 // Emplace 723 template<typename... _Args> 724 __ireturn_type 725 emplace(_Args&&... __args) 726 { return _M_emplace(__unique_keys(), std::forward<_Args>(__args)...); } 727 728 template<typename... _Args> 729 iterator 730 emplace_hint(const_iterator __hint, _Args&&... __args) 731 { 732 return _M_emplace(__hint, __unique_keys(), 733 std::forward<_Args>(__args)...); 734 } 735 736 // Insert member functions via inheritance. 737 738 // Erase 739 iterator 740 erase(const_iterator); 741 742 // LWG 2059. 743 iterator 744 erase(iterator __it) 745 { return erase(const_iterator(__it)); } 746 747 size_type 748 erase(const key_type& __k) 749 { return _M_erase(__unique_keys(), __k); } 750 751 iterator 752 erase(const_iterator, const_iterator); 753 754 void 755 clear() noexcept; 756 757 // Set number of buckets to be appropriate for container of n element. 758 void rehash(size_type __n); 759 760 // DR 1189. 761 // reserve, if present, comes from _Rehash_base. 762 763 private: 764 // Helper rehash method used when keys are unique. 765 void _M_rehash_aux(size_type __n, std::true_type); 766 767 // Helper rehash method used when keys can be non-unique. 768 void _M_rehash_aux(size_type __n, std::false_type); 769 770 // Unconditionally change size of bucket array to n, restore 771 // hash policy state to __state on exception. 772 void _M_rehash(size_type __n, const __rehash_state& __state); 773 }; 774 775 776 // Definitions of class template _Hashtable's out-of-line member functions. 777 template<typename _Key, typename _Value, 778 typename _Alloc, typename _ExtractKey, typename _Equal, 779 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 780 typename _Traits> 781 auto 782 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 783 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 784 _M_bucket_begin(size_type __bkt) const 785 -> __node_type* 786 { 787 __node_base* __n = _M_buckets[__bkt]; 788 return __n ? static_cast<__node_type*>(__n->_M_nxt) : nullptr; 789 } 790 791 template<typename _Key, typename _Value, 792 typename _Alloc, typename _ExtractKey, typename _Equal, 793 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 794 typename _Traits> 795 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 796 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 797 _Hashtable(size_type __bucket_hint, 798 const _H1& __h1, const _H2& __h2, const _Hash& __h, 799 const _Equal& __eq, const _ExtractKey& __exk, 800 const allocator_type& __a) 801 : _Hashtable(__h1, __h2, __h, __eq, __exk, __a) 802 { 803 auto __bkt = _M_rehash_policy._M_next_bkt(__bucket_hint); 804 if (__bkt > _M_bucket_count) 805 { 806 _M_buckets = _M_allocate_buckets(__bkt); 807 _M_bucket_count = __bkt; 808 } 809 } 810 811 template<typename _Key, typename _Value, 812 typename _Alloc, typename _ExtractKey, typename _Equal, 813 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 814 typename _Traits> 815 template<typename _InputIterator> 816 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 817 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 818 _Hashtable(_InputIterator __f, _InputIterator __l, 819 size_type __bucket_hint, 820 const _H1& __h1, const _H2& __h2, const _Hash& __h, 821 const _Equal& __eq, const _ExtractKey& __exk, 822 const allocator_type& __a) 823 : _Hashtable(__h1, __h2, __h, __eq, __exk, __a) 824 { 825 auto __nb_elems = __detail::__distance_fw(__f, __l); 826 auto __bkt_count = 827 _M_rehash_policy._M_next_bkt( 828 std::max(_M_rehash_policy._M_bkt_for_elements(__nb_elems), 829 __bucket_hint)); 830 831 if (__bkt_count > _M_bucket_count) 832 { 833 _M_buckets = _M_allocate_buckets(__bkt_count); 834 _M_bucket_count = __bkt_count; 835 } 836 837 __try 838 { 839 for (; __f != __l; ++__f) 840 this->insert(*__f); 841 } 842 __catch(...) 843 { 844 clear(); 845 _M_deallocate_buckets(); 846 __throw_exception_again; 847 } 848 } 849 850 template<typename _Key, typename _Value, 851 typename _Alloc, typename _ExtractKey, typename _Equal, 852 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 853 typename _Traits> 854 auto 855 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 856 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 857 operator=(const _Hashtable& __ht) 858 -> _Hashtable& 859 { 860 if (&__ht == this) 861 return *this; 862 863 if (__node_alloc_traits::_S_propagate_on_copy_assign()) 864 { 865 auto& __this_alloc = this->_M_node_allocator(); 866 auto& __that_alloc = __ht._M_node_allocator(); 867 if (!__node_alloc_traits::_S_always_equal() 868 && __this_alloc != __that_alloc) 869 { 870 // Replacement allocator cannot free existing storage. 871 this->_M_deallocate_nodes(_M_begin()); 872 _M_before_begin._M_nxt = nullptr; 873 _M_deallocate_buckets(); 874 _M_buckets = nullptr; 875 std::__alloc_on_copy(__this_alloc, __that_alloc); 876 __hashtable_base::operator=(__ht); 877 _M_bucket_count = __ht._M_bucket_count; 878 _M_element_count = __ht._M_element_count; 879 _M_rehash_policy = __ht._M_rehash_policy; 880 __try 881 { 882 _M_assign(__ht, 883 [this](const __node_type* __n) 884 { return this->_M_allocate_node(__n->_M_v()); }); 885 } 886 __catch(...) 887 { 888 // _M_assign took care of deallocating all memory. Now we 889 // must make sure this instance remains in a usable state. 890 _M_reset(); 891 __throw_exception_again; 892 } 893 return *this; 894 } 895 std::__alloc_on_copy(__this_alloc, __that_alloc); 896 } 897 898 // Reuse allocated buckets and nodes. 899 __bucket_type* __former_buckets = nullptr; 900 std::size_t __former_bucket_count = _M_bucket_count; 901 const __rehash_state& __former_state = _M_rehash_policy._M_state(); 902 903 if (_M_bucket_count != __ht._M_bucket_count) 904 { 905 __former_buckets = _M_buckets; 906 _M_buckets = _M_allocate_buckets(__ht._M_bucket_count); 907 _M_bucket_count = __ht._M_bucket_count; 908 } 909 else 910 __builtin_memset(_M_buckets, 0, 911 _M_bucket_count * sizeof(__bucket_type)); 912 913 __try 914 { 915 __hashtable_base::operator=(__ht); 916 _M_element_count = __ht._M_element_count; 917 _M_rehash_policy = __ht._M_rehash_policy; 918 __reuse_or_alloc_node_type __roan(_M_begin(), *this); 919 _M_before_begin._M_nxt = nullptr; 920 _M_assign(__ht, 921 [&__roan](const __node_type* __n) 922 { return __roan(__n->_M_v()); }); 923 if (__former_buckets) 924 _M_deallocate_buckets(__former_buckets, __former_bucket_count); 925 } 926 __catch(...) 927 { 928 if (__former_buckets) 929 { 930 // Restore previous buckets. 931 _M_deallocate_buckets(); 932 _M_rehash_policy._M_reset(__former_state); 933 _M_buckets = __former_buckets; 934 _M_bucket_count = __former_bucket_count; 935 } 936 __builtin_memset(_M_buckets, 0, 937 _M_bucket_count * sizeof(__bucket_type)); 938 __throw_exception_again; 939 } 940 return *this; 941 } 942 943 template<typename _Key, typename _Value, 944 typename _Alloc, typename _ExtractKey, typename _Equal, 945 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 946 typename _Traits> 947 template<typename _NodeGenerator> 948 void 949 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 950 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 951 _M_assign(const _Hashtable& __ht, const _NodeGenerator& __node_gen) 952 { 953 __bucket_type* __buckets = nullptr; 954 if (!_M_buckets) 955 _M_buckets = __buckets = _M_allocate_buckets(_M_bucket_count); 956 957 __try 958 { 959 if (!__ht._M_before_begin._M_nxt) 960 return; 961 962 // First deal with the special first node pointed to by 963 // _M_before_begin. 964 __node_type* __ht_n = __ht._M_begin(); 965 __node_type* __this_n = __node_gen(__ht_n); 966 this->_M_copy_code(__this_n, __ht_n); 967 _M_before_begin._M_nxt = __this_n; 968 _M_buckets[_M_bucket_index(__this_n)] = &_M_before_begin; 969 970 // Then deal with other nodes. 971 __node_base* __prev_n = __this_n; 972 for (__ht_n = __ht_n->_M_next(); __ht_n; __ht_n = __ht_n->_M_next()) 973 { 974 __this_n = __node_gen(__ht_n); 975 __prev_n->_M_nxt = __this_n; 976 this->_M_copy_code(__this_n, __ht_n); 977 size_type __bkt = _M_bucket_index(__this_n); 978 if (!_M_buckets[__bkt]) 979 _M_buckets[__bkt] = __prev_n; 980 __prev_n = __this_n; 981 } 982 } 983 __catch(...) 984 { 985 clear(); 986 if (__buckets) 987 _M_deallocate_buckets(); 988 __throw_exception_again; 989 } 990 } 991 992 template<typename _Key, typename _Value, 993 typename _Alloc, typename _ExtractKey, typename _Equal, 994 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 995 typename _Traits> 996 void 997 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 998 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 999 _M_reset() noexcept 1000 { 1001 _M_rehash_policy._M_reset(); 1002 _M_bucket_count = 1; 1003 _M_single_bucket = nullptr; 1004 _M_buckets = &_M_single_bucket; 1005 _M_before_begin._M_nxt = nullptr; 1006 _M_element_count = 0; 1007 } 1008 1009 template<typename _Key, typename _Value, 1010 typename _Alloc, typename _ExtractKey, typename _Equal, 1011 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1012 typename _Traits> 1013 void 1014 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1015 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1016 _M_move_assign(_Hashtable&& __ht, std::true_type) 1017 { 1018 this->_M_deallocate_nodes(_M_begin()); 1019 _M_deallocate_buckets(); 1020 __hashtable_base::operator=(std::move(__ht)); 1021 _M_rehash_policy = __ht._M_rehash_policy; 1022 if (!__ht._M_uses_single_bucket()) 1023 _M_buckets = __ht._M_buckets; 1024 else 1025 { 1026 _M_buckets = &_M_single_bucket; 1027 _M_single_bucket = __ht._M_single_bucket; 1028 } 1029 _M_bucket_count = __ht._M_bucket_count; 1030 _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt; 1031 _M_element_count = __ht._M_element_count; 1032 std::__alloc_on_move(this->_M_node_allocator(), __ht._M_node_allocator()); 1033 1034 // Fix buckets containing the _M_before_begin pointers that can't be 1035 // moved. 1036 if (_M_begin()) 1037 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; 1038 __ht._M_reset(); 1039 } 1040 1041 template<typename _Key, typename _Value, 1042 typename _Alloc, typename _ExtractKey, typename _Equal, 1043 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1044 typename _Traits> 1045 void 1046 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1047 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1048 _M_move_assign(_Hashtable&& __ht, std::false_type) 1049 { 1050 if (__ht._M_node_allocator() == this->_M_node_allocator()) 1051 _M_move_assign(std::move(__ht), std::true_type()); 1052 else 1053 { 1054 // Can't move memory, move elements then. 1055 __bucket_type* __former_buckets = nullptr; 1056 size_type __former_bucket_count = _M_bucket_count; 1057 const __rehash_state& __former_state = _M_rehash_policy._M_state(); 1058 1059 if (_M_bucket_count != __ht._M_bucket_count) 1060 { 1061 __former_buckets = _M_buckets; 1062 _M_buckets = _M_allocate_buckets(__ht._M_bucket_count); 1063 _M_bucket_count = __ht._M_bucket_count; 1064 } 1065 else 1066 __builtin_memset(_M_buckets, 0, 1067 _M_bucket_count * sizeof(__bucket_type)); 1068 1069 __try 1070 { 1071 __hashtable_base::operator=(std::move(__ht)); 1072 _M_element_count = __ht._M_element_count; 1073 _M_rehash_policy = __ht._M_rehash_policy; 1074 __reuse_or_alloc_node_type __roan(_M_begin(), *this); 1075 _M_before_begin._M_nxt = nullptr; 1076 _M_assign(__ht, 1077 [&__roan](__node_type* __n) 1078 { return __roan(std::move_if_noexcept(__n->_M_v())); }); 1079 __ht.clear(); 1080 } 1081 __catch(...) 1082 { 1083 if (__former_buckets) 1084 { 1085 _M_deallocate_buckets(); 1086 _M_rehash_policy._M_reset(__former_state); 1087 _M_buckets = __former_buckets; 1088 _M_bucket_count = __former_bucket_count; 1089 } 1090 __builtin_memset(_M_buckets, 0, 1091 _M_bucket_count * sizeof(__bucket_type)); 1092 __throw_exception_again; 1093 } 1094 } 1095 } 1096 1097 template<typename _Key, typename _Value, 1098 typename _Alloc, typename _ExtractKey, typename _Equal, 1099 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1100 typename _Traits> 1101 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1102 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1103 _Hashtable(const _Hashtable& __ht) 1104 : __hashtable_base(__ht), 1105 __map_base(__ht), 1106 __rehash_base(__ht), 1107 __hashtable_alloc( 1108 __node_alloc_traits::_S_select_on_copy(__ht._M_node_allocator())), 1109 _M_buckets(nullptr), 1110 _M_bucket_count(__ht._M_bucket_count), 1111 _M_element_count(__ht._M_element_count), 1112 _M_rehash_policy(__ht._M_rehash_policy) 1113 { 1114 _M_assign(__ht, 1115 [this](const __node_type* __n) 1116 { return this->_M_allocate_node(__n->_M_v()); }); 1117 } 1118 1119 template<typename _Key, typename _Value, 1120 typename _Alloc, typename _ExtractKey, typename _Equal, 1121 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1122 typename _Traits> 1123 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1124 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1125 _Hashtable(_Hashtable&& __ht) noexcept 1126 : __hashtable_base(__ht), 1127 __map_base(__ht), 1128 __rehash_base(__ht), 1129 __hashtable_alloc(std::move(__ht._M_base_alloc())), 1130 _M_buckets(__ht._M_buckets), 1131 _M_bucket_count(__ht._M_bucket_count), 1132 _M_before_begin(__ht._M_before_begin._M_nxt), 1133 _M_element_count(__ht._M_element_count), 1134 _M_rehash_policy(__ht._M_rehash_policy) 1135 { 1136 // Update, if necessary, buckets if __ht is using its single bucket. 1137 if (__ht._M_uses_single_bucket()) 1138 { 1139 _M_buckets = &_M_single_bucket; 1140 _M_single_bucket = __ht._M_single_bucket; 1141 } 1142 1143 // Update, if necessary, bucket pointing to before begin that hasn't 1144 // moved. 1145 if (_M_begin()) 1146 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; 1147 1148 __ht._M_reset(); 1149 } 1150 1151 template<typename _Key, typename _Value, 1152 typename _Alloc, typename _ExtractKey, typename _Equal, 1153 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1154 typename _Traits> 1155 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1156 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1157 _Hashtable(const _Hashtable& __ht, const allocator_type& __a) 1158 : __hashtable_base(__ht), 1159 __map_base(__ht), 1160 __rehash_base(__ht), 1161 __hashtable_alloc(__node_alloc_type(__a)), 1162 _M_buckets(), 1163 _M_bucket_count(__ht._M_bucket_count), 1164 _M_element_count(__ht._M_element_count), 1165 _M_rehash_policy(__ht._M_rehash_policy) 1166 { 1167 _M_assign(__ht, 1168 [this](const __node_type* __n) 1169 { return this->_M_allocate_node(__n->_M_v()); }); 1170 } 1171 1172 template<typename _Key, typename _Value, 1173 typename _Alloc, typename _ExtractKey, typename _Equal, 1174 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1175 typename _Traits> 1176 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1177 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1178 _Hashtable(_Hashtable&& __ht, const allocator_type& __a) 1179 : __hashtable_base(__ht), 1180 __map_base(__ht), 1181 __rehash_base(__ht), 1182 __hashtable_alloc(__node_alloc_type(__a)), 1183 _M_buckets(nullptr), 1184 _M_bucket_count(__ht._M_bucket_count), 1185 _M_element_count(__ht._M_element_count), 1186 _M_rehash_policy(__ht._M_rehash_policy) 1187 { 1188 if (__ht._M_node_allocator() == this->_M_node_allocator()) 1189 { 1190 if (__ht._M_uses_single_bucket()) 1191 { 1192 _M_buckets = &_M_single_bucket; 1193 _M_single_bucket = __ht._M_single_bucket; 1194 } 1195 else 1196 _M_buckets = __ht._M_buckets; 1197 1198 _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt; 1199 // Update, if necessary, bucket pointing to before begin that hasn't 1200 // moved. 1201 if (_M_begin()) 1202 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; 1203 __ht._M_reset(); 1204 } 1205 else 1206 { 1207 _M_assign(__ht, 1208 [this](__node_type* __n) 1209 { 1210 return this->_M_allocate_node( 1211 std::move_if_noexcept(__n->_M_v())); 1212 }); 1213 __ht.clear(); 1214 } 1215 } 1216 1217 template<typename _Key, typename _Value, 1218 typename _Alloc, typename _ExtractKey, typename _Equal, 1219 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1220 typename _Traits> 1221 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1222 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1223 ~_Hashtable() noexcept 1224 { 1225 clear(); 1226 _M_deallocate_buckets(); 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 void 1234 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1235 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1236 swap(_Hashtable& __x) 1237 noexcept(__node_alloc_traits::_S_nothrow_swap()) 1238 { 1239 // The only base class with member variables is hash_code_base. 1240 // We define _Hash_code_base::_M_swap because different 1241 // specializations have different members. 1242 this->_M_swap(__x); 1243 1244 std::__alloc_on_swap(this->_M_node_allocator(), __x._M_node_allocator()); 1245 std::swap(_M_rehash_policy, __x._M_rehash_policy); 1246 1247 // Deal properly with potentially moved instances. 1248 if (this->_M_uses_single_bucket()) 1249 { 1250 if (!__x._M_uses_single_bucket()) 1251 { 1252 _M_buckets = __x._M_buckets; 1253 __x._M_buckets = &__x._M_single_bucket; 1254 } 1255 } 1256 else if (__x._M_uses_single_bucket()) 1257 { 1258 __x._M_buckets = _M_buckets; 1259 _M_buckets = &_M_single_bucket; 1260 } 1261 else 1262 std::swap(_M_buckets, __x._M_buckets); 1263 1264 std::swap(_M_bucket_count, __x._M_bucket_count); 1265 std::swap(_M_before_begin._M_nxt, __x._M_before_begin._M_nxt); 1266 std::swap(_M_element_count, __x._M_element_count); 1267 std::swap(_M_single_bucket, __x._M_single_bucket); 1268 1269 // Fix buckets containing the _M_before_begin pointers that can't be 1270 // swapped. 1271 if (_M_begin()) 1272 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; 1273 1274 if (__x._M_begin()) 1275 __x._M_buckets[__x._M_bucket_index(__x._M_begin())] 1276 = &__x._M_before_begin; 1277 } 1278 1279 template<typename _Key, typename _Value, 1280 typename _Alloc, typename _ExtractKey, typename _Equal, 1281 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1282 typename _Traits> 1283 void 1284 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1285 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1286 __rehash_policy(const _RehashPolicy& __pol) 1287 { 1288 auto __do_rehash = 1289 __pol._M_need_rehash(_M_bucket_count, _M_element_count, 0); 1290 if (__do_rehash.first) 1291 _M_rehash(__do_rehash.second, _M_rehash_policy._M_state()); 1292 _M_rehash_policy = __pol; 1293 } 1294 1295 template<typename _Key, typename _Value, 1296 typename _Alloc, typename _ExtractKey, typename _Equal, 1297 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1298 typename _Traits> 1299 auto 1300 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1301 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1302 find(const key_type& __k) 1303 -> iterator 1304 { 1305 __hash_code __code = this->_M_hash_code(__k); 1306 std::size_t __n = _M_bucket_index(__k, __code); 1307 __node_type* __p = _M_find_node(__n, __k, __code); 1308 return __p ? iterator(__p) : end(); 1309 } 1310 1311 template<typename _Key, typename _Value, 1312 typename _Alloc, typename _ExtractKey, typename _Equal, 1313 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1314 typename _Traits> 1315 auto 1316 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1317 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1318 find(const key_type& __k) const 1319 -> const_iterator 1320 { 1321 __hash_code __code = this->_M_hash_code(__k); 1322 std::size_t __n = _M_bucket_index(__k, __code); 1323 __node_type* __p = _M_find_node(__n, __k, __code); 1324 return __p ? const_iterator(__p) : end(); 1325 } 1326 1327 template<typename _Key, typename _Value, 1328 typename _Alloc, typename _ExtractKey, typename _Equal, 1329 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1330 typename _Traits> 1331 auto 1332 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1333 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1334 count(const key_type& __k) const 1335 -> size_type 1336 { 1337 __hash_code __code = this->_M_hash_code(__k); 1338 std::size_t __n = _M_bucket_index(__k, __code); 1339 __node_type* __p = _M_bucket_begin(__n); 1340 if (!__p) 1341 return 0; 1342 1343 std::size_t __result = 0; 1344 for (;; __p = __p->_M_next()) 1345 { 1346 if (this->_M_equals(__k, __code, __p)) 1347 ++__result; 1348 else if (__result) 1349 // All equivalent values are next to each other, if we 1350 // found a non-equivalent value after an equivalent one it 1351 // means that we won't find any new equivalent value. 1352 break; 1353 if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n) 1354 break; 1355 } 1356 return __result; 1357 } 1358 1359 template<typename _Key, typename _Value, 1360 typename _Alloc, typename _ExtractKey, typename _Equal, 1361 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1362 typename _Traits> 1363 auto 1364 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1365 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1366 equal_range(const key_type& __k) 1367 -> pair<iterator, iterator> 1368 { 1369 __hash_code __code = this->_M_hash_code(__k); 1370 std::size_t __n = _M_bucket_index(__k, __code); 1371 __node_type* __p = _M_find_node(__n, __k, __code); 1372 1373 if (__p) 1374 { 1375 __node_type* __p1 = __p->_M_next(); 1376 while (__p1 && _M_bucket_index(__p1) == __n 1377 && this->_M_equals(__k, __code, __p1)) 1378 __p1 = __p1->_M_next(); 1379 1380 return std::make_pair(iterator(__p), iterator(__p1)); 1381 } 1382 else 1383 return std::make_pair(end(), end()); 1384 } 1385 1386 template<typename _Key, typename _Value, 1387 typename _Alloc, typename _ExtractKey, typename _Equal, 1388 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1389 typename _Traits> 1390 auto 1391 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1392 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1393 equal_range(const key_type& __k) const 1394 -> pair<const_iterator, const_iterator> 1395 { 1396 __hash_code __code = this->_M_hash_code(__k); 1397 std::size_t __n = _M_bucket_index(__k, __code); 1398 __node_type* __p = _M_find_node(__n, __k, __code); 1399 1400 if (__p) 1401 { 1402 __node_type* __p1 = __p->_M_next(); 1403 while (__p1 && _M_bucket_index(__p1) == __n 1404 && this->_M_equals(__k, __code, __p1)) 1405 __p1 = __p1->_M_next(); 1406 1407 return std::make_pair(const_iterator(__p), const_iterator(__p1)); 1408 } 1409 else 1410 return std::make_pair(end(), end()); 1411 } 1412 1413 // Find the node whose key compares equal to k in the bucket n. 1414 // Return nullptr if no node is found. 1415 template<typename _Key, typename _Value, 1416 typename _Alloc, typename _ExtractKey, typename _Equal, 1417 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1418 typename _Traits> 1419 auto 1420 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1421 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1422 _M_find_before_node(size_type __n, const key_type& __k, 1423 __hash_code __code) const 1424 -> __node_base* 1425 { 1426 __node_base* __prev_p = _M_buckets[__n]; 1427 if (!__prev_p) 1428 return nullptr; 1429 1430 for (__node_type* __p = static_cast<__node_type*>(__prev_p->_M_nxt);; 1431 __p = __p->_M_next()) 1432 { 1433 if (this->_M_equals(__k, __code, __p)) 1434 return __prev_p; 1435 1436 if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n) 1437 break; 1438 __prev_p = __p; 1439 } 1440 return nullptr; 1441 } 1442 1443 template<typename _Key, typename _Value, 1444 typename _Alloc, typename _ExtractKey, typename _Equal, 1445 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1446 typename _Traits> 1447 void 1448 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1449 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1450 _M_insert_bucket_begin(size_type __bkt, __node_type* __node) 1451 { 1452 if (_M_buckets[__bkt]) 1453 { 1454 // Bucket is not empty, we just need to insert the new node 1455 // after the bucket before begin. 1456 __node->_M_nxt = _M_buckets[__bkt]->_M_nxt; 1457 _M_buckets[__bkt]->_M_nxt = __node; 1458 } 1459 else 1460 { 1461 // The bucket is empty, the new node is inserted at the 1462 // beginning of the singly-linked list and the bucket will 1463 // contain _M_before_begin pointer. 1464 __node->_M_nxt = _M_before_begin._M_nxt; 1465 _M_before_begin._M_nxt = __node; 1466 if (__node->_M_nxt) 1467 // We must update former begin bucket that is pointing to 1468 // _M_before_begin. 1469 _M_buckets[_M_bucket_index(__node->_M_next())] = __node; 1470 _M_buckets[__bkt] = &_M_before_begin; 1471 } 1472 } 1473 1474 template<typename _Key, typename _Value, 1475 typename _Alloc, typename _ExtractKey, typename _Equal, 1476 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1477 typename _Traits> 1478 void 1479 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1480 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1481 _M_remove_bucket_begin(size_type __bkt, __node_type* __next, 1482 size_type __next_bkt) 1483 { 1484 if (!__next || __next_bkt != __bkt) 1485 { 1486 // Bucket is now empty 1487 // First update next bucket if any 1488 if (__next) 1489 _M_buckets[__next_bkt] = _M_buckets[__bkt]; 1490 1491 // Second update before begin node if necessary 1492 if (&_M_before_begin == _M_buckets[__bkt]) 1493 _M_before_begin._M_nxt = __next; 1494 _M_buckets[__bkt] = nullptr; 1495 } 1496 } 1497 1498 template<typename _Key, typename _Value, 1499 typename _Alloc, typename _ExtractKey, typename _Equal, 1500 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1501 typename _Traits> 1502 auto 1503 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1504 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1505 _M_get_previous_node(size_type __bkt, __node_base* __n) 1506 -> __node_base* 1507 { 1508 __node_base* __prev_n = _M_buckets[__bkt]; 1509 while (__prev_n->_M_nxt != __n) 1510 __prev_n = __prev_n->_M_nxt; 1511 return __prev_n; 1512 } 1513 1514 template<typename _Key, typename _Value, 1515 typename _Alloc, typename _ExtractKey, typename _Equal, 1516 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1517 typename _Traits> 1518 template<typename... _Args> 1519 auto 1520 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1521 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1522 _M_emplace(std::true_type, _Args&&... __args) 1523 -> pair<iterator, bool> 1524 { 1525 // First build the node to get access to the hash code 1526 __node_type* __node = this->_M_allocate_node(std::forward<_Args>(__args)...); 1527 const key_type& __k = this->_M_extract()(__node->_M_v()); 1528 __hash_code __code; 1529 __try 1530 { 1531 __code = this->_M_hash_code(__k); 1532 } 1533 __catch(...) 1534 { 1535 this->_M_deallocate_node(__node); 1536 __throw_exception_again; 1537 } 1538 1539 size_type __bkt = _M_bucket_index(__k, __code); 1540 if (__node_type* __p = _M_find_node(__bkt, __k, __code)) 1541 { 1542 // There is already an equivalent node, no insertion 1543 this->_M_deallocate_node(__node); 1544 return std::make_pair(iterator(__p), false); 1545 } 1546 1547 // Insert the node 1548 return std::make_pair(_M_insert_unique_node(__bkt, __code, __node), 1549 true); 1550 } 1551 1552 template<typename _Key, typename _Value, 1553 typename _Alloc, typename _ExtractKey, typename _Equal, 1554 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1555 typename _Traits> 1556 template<typename... _Args> 1557 auto 1558 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1559 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1560 _M_emplace(const_iterator __hint, std::false_type, _Args&&... __args) 1561 -> iterator 1562 { 1563 // First build the node to get its hash code. 1564 __node_type* __node = 1565 this->_M_allocate_node(std::forward<_Args>(__args)...); 1566 1567 __hash_code __code; 1568 __try 1569 { 1570 __code = this->_M_hash_code(this->_M_extract()(__node->_M_v())); 1571 } 1572 __catch(...) 1573 { 1574 this->_M_deallocate_node(__node); 1575 __throw_exception_again; 1576 } 1577 1578 return _M_insert_multi_node(__hint._M_cur, __code, __node); 1579 } 1580 1581 template<typename _Key, typename _Value, 1582 typename _Alloc, typename _ExtractKey, typename _Equal, 1583 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1584 typename _Traits> 1585 auto 1586 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1587 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1588 _M_insert_unique_node(size_type __bkt, __hash_code __code, 1589 __node_type* __node) 1590 -> iterator 1591 { 1592 const __rehash_state& __saved_state = _M_rehash_policy._M_state(); 1593 std::pair<bool, std::size_t> __do_rehash 1594 = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 1); 1595 1596 __try 1597 { 1598 if (__do_rehash.first) 1599 { 1600 _M_rehash(__do_rehash.second, __saved_state); 1601 __bkt = _M_bucket_index(this->_M_extract()(__node->_M_v()), __code); 1602 } 1603 1604 this->_M_store_code(__node, __code); 1605 1606 // Always insert at the beginning of the bucket. 1607 _M_insert_bucket_begin(__bkt, __node); 1608 ++_M_element_count; 1609 return iterator(__node); 1610 } 1611 __catch(...) 1612 { 1613 this->_M_deallocate_node(__node); 1614 __throw_exception_again; 1615 } 1616 } 1617 1618 // Insert node, in bucket bkt if no rehash (assumes no element with its key 1619 // already present). Take ownership of the node, deallocate it on exception. 1620 template<typename _Key, typename _Value, 1621 typename _Alloc, typename _ExtractKey, typename _Equal, 1622 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1623 typename _Traits> 1624 auto 1625 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1626 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1627 _M_insert_multi_node(__node_type* __hint, __hash_code __code, 1628 __node_type* __node) 1629 -> iterator 1630 { 1631 const __rehash_state& __saved_state = _M_rehash_policy._M_state(); 1632 std::pair<bool, std::size_t> __do_rehash 1633 = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 1); 1634 1635 __try 1636 { 1637 if (__do_rehash.first) 1638 _M_rehash(__do_rehash.second, __saved_state); 1639 1640 this->_M_store_code(__node, __code); 1641 const key_type& __k = this->_M_extract()(__node->_M_v()); 1642 size_type __bkt = _M_bucket_index(__k, __code); 1643 1644 // Find the node before an equivalent one or use hint if it exists and 1645 // if it is equivalent. 1646 __node_base* __prev 1647 = __builtin_expect(__hint != nullptr, false) 1648 && this->_M_equals(__k, __code, __hint) 1649 ? __hint 1650 : _M_find_before_node(__bkt, __k, __code); 1651 if (__prev) 1652 { 1653 // Insert after the node before the equivalent one. 1654 __node->_M_nxt = __prev->_M_nxt; 1655 __prev->_M_nxt = __node; 1656 if (__builtin_expect(__prev == __hint, false)) 1657 // hint might be the last bucket node, in this case we need to 1658 // update next bucket. 1659 if (__node->_M_nxt 1660 && !this->_M_equals(__k, __code, __node->_M_next())) 1661 { 1662 size_type __next_bkt = _M_bucket_index(__node->_M_next()); 1663 if (__next_bkt != __bkt) 1664 _M_buckets[__next_bkt] = __node; 1665 } 1666 } 1667 else 1668 // The inserted node has no equivalent in the 1669 // hashtable. We must insert the new node at the 1670 // beginning of the bucket to preserve equivalent 1671 // elements' relative positions. 1672 _M_insert_bucket_begin(__bkt, __node); 1673 ++_M_element_count; 1674 return iterator(__node); 1675 } 1676 __catch(...) 1677 { 1678 this->_M_deallocate_node(__node); 1679 __throw_exception_again; 1680 } 1681 } 1682 1683 // Insert v if no element with its key is already present. 1684 template<typename _Key, typename _Value, 1685 typename _Alloc, typename _ExtractKey, typename _Equal, 1686 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1687 typename _Traits> 1688 template<typename _Arg, typename _NodeGenerator> 1689 auto 1690 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1691 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1692 _M_insert(_Arg&& __v, const _NodeGenerator& __node_gen, std::true_type) 1693 -> pair<iterator, bool> 1694 { 1695 const key_type& __k = this->_M_extract()(__v); 1696 __hash_code __code = this->_M_hash_code(__k); 1697 size_type __bkt = _M_bucket_index(__k, __code); 1698 1699 __node_type* __n = _M_find_node(__bkt, __k, __code); 1700 if (__n) 1701 return std::make_pair(iterator(__n), false); 1702 1703 __n = __node_gen(std::forward<_Arg>(__v)); 1704 return std::make_pair(_M_insert_unique_node(__bkt, __code, __n), true); 1705 } 1706 1707 // Insert v unconditionally. 1708 template<typename _Key, typename _Value, 1709 typename _Alloc, typename _ExtractKey, typename _Equal, 1710 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1711 typename _Traits> 1712 template<typename _Arg, typename _NodeGenerator> 1713 auto 1714 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1715 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1716 _M_insert(const_iterator __hint, _Arg&& __v, 1717 const _NodeGenerator& __node_gen, std::false_type) 1718 -> iterator 1719 { 1720 // First compute the hash code so that we don't do anything if it 1721 // throws. 1722 __hash_code __code = this->_M_hash_code(this->_M_extract()(__v)); 1723 1724 // Second allocate new node so that we don't rehash if it throws. 1725 __node_type* __node = __node_gen(std::forward<_Arg>(__v)); 1726 1727 return _M_insert_multi_node(__hint._M_cur, __code, __node); 1728 } 1729 1730 template<typename _Key, typename _Value, 1731 typename _Alloc, typename _ExtractKey, typename _Equal, 1732 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1733 typename _Traits> 1734 auto 1735 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1736 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1737 erase(const_iterator __it) 1738 -> iterator 1739 { 1740 __node_type* __n = __it._M_cur; 1741 std::size_t __bkt = _M_bucket_index(__n); 1742 1743 // Look for previous node to unlink it from the erased one, this 1744 // is why we need buckets to contain the before begin to make 1745 // this search fast. 1746 __node_base* __prev_n = _M_get_previous_node(__bkt, __n); 1747 return _M_erase(__bkt, __prev_n, __n); 1748 } 1749 1750 template<typename _Key, typename _Value, 1751 typename _Alloc, typename _ExtractKey, typename _Equal, 1752 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1753 typename _Traits> 1754 auto 1755 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1756 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1757 _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n) 1758 -> iterator 1759 { 1760 if (__prev_n == _M_buckets[__bkt]) 1761 _M_remove_bucket_begin(__bkt, __n->_M_next(), 1762 __n->_M_nxt ? _M_bucket_index(__n->_M_next()) : 0); 1763 else if (__n->_M_nxt) 1764 { 1765 size_type __next_bkt = _M_bucket_index(__n->_M_next()); 1766 if (__next_bkt != __bkt) 1767 _M_buckets[__next_bkt] = __prev_n; 1768 } 1769 1770 __prev_n->_M_nxt = __n->_M_nxt; 1771 iterator __result(__n->_M_next()); 1772 this->_M_deallocate_node(__n); 1773 --_M_element_count; 1774 1775 return __result; 1776 } 1777 1778 template<typename _Key, typename _Value, 1779 typename _Alloc, typename _ExtractKey, typename _Equal, 1780 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1781 typename _Traits> 1782 auto 1783 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1784 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1785 _M_erase(std::true_type, const key_type& __k) 1786 -> size_type 1787 { 1788 __hash_code __code = this->_M_hash_code(__k); 1789 std::size_t __bkt = _M_bucket_index(__k, __code); 1790 1791 // Look for the node before the first matching node. 1792 __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code); 1793 if (!__prev_n) 1794 return 0; 1795 1796 // We found a matching node, erase it. 1797 __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt); 1798 _M_erase(__bkt, __prev_n, __n); 1799 return 1; 1800 } 1801 1802 template<typename _Key, typename _Value, 1803 typename _Alloc, typename _ExtractKey, typename _Equal, 1804 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1805 typename _Traits> 1806 auto 1807 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1808 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1809 _M_erase(std::false_type, const key_type& __k) 1810 -> size_type 1811 { 1812 __hash_code __code = this->_M_hash_code(__k); 1813 std::size_t __bkt = _M_bucket_index(__k, __code); 1814 1815 // Look for the node before the first matching node. 1816 __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code); 1817 if (!__prev_n) 1818 return 0; 1819 1820 // _GLIBCXX_RESOLVE_LIB_DEFECTS 1821 // 526. Is it undefined if a function in the standard changes 1822 // in parameters? 1823 // We use one loop to find all matching nodes and another to deallocate 1824 // them so that the key stays valid during the first loop. It might be 1825 // invalidated indirectly when destroying nodes. 1826 __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt); 1827 __node_type* __n_last = __n; 1828 std::size_t __n_last_bkt = __bkt; 1829 do 1830 { 1831 __n_last = __n_last->_M_next(); 1832 if (!__n_last) 1833 break; 1834 __n_last_bkt = _M_bucket_index(__n_last); 1835 } 1836 while (__n_last_bkt == __bkt && this->_M_equals(__k, __code, __n_last)); 1837 1838 // Deallocate nodes. 1839 size_type __result = 0; 1840 do 1841 { 1842 __node_type* __p = __n->_M_next(); 1843 this->_M_deallocate_node(__n); 1844 __n = __p; 1845 ++__result; 1846 --_M_element_count; 1847 } 1848 while (__n != __n_last); 1849 1850 if (__prev_n == _M_buckets[__bkt]) 1851 _M_remove_bucket_begin(__bkt, __n_last, __n_last_bkt); 1852 else if (__n_last && __n_last_bkt != __bkt) 1853 _M_buckets[__n_last_bkt] = __prev_n; 1854 __prev_n->_M_nxt = __n_last; 1855 return __result; 1856 } 1857 1858 template<typename _Key, typename _Value, 1859 typename _Alloc, typename _ExtractKey, typename _Equal, 1860 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1861 typename _Traits> 1862 auto 1863 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1864 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1865 erase(const_iterator __first, const_iterator __last) 1866 -> iterator 1867 { 1868 __node_type* __n = __first._M_cur; 1869 __node_type* __last_n = __last._M_cur; 1870 if (__n == __last_n) 1871 return iterator(__n); 1872 1873 std::size_t __bkt = _M_bucket_index(__n); 1874 1875 __node_base* __prev_n = _M_get_previous_node(__bkt, __n); 1876 bool __is_bucket_begin = __n == _M_bucket_begin(__bkt); 1877 std::size_t __n_bkt = __bkt; 1878 for (;;) 1879 { 1880 do 1881 { 1882 __node_type* __tmp = __n; 1883 __n = __n->_M_next(); 1884 this->_M_deallocate_node(__tmp); 1885 --_M_element_count; 1886 if (!__n) 1887 break; 1888 __n_bkt = _M_bucket_index(__n); 1889 } 1890 while (__n != __last_n && __n_bkt == __bkt); 1891 if (__is_bucket_begin) 1892 _M_remove_bucket_begin(__bkt, __n, __n_bkt); 1893 if (__n == __last_n) 1894 break; 1895 __is_bucket_begin = true; 1896 __bkt = __n_bkt; 1897 } 1898 1899 if (__n && (__n_bkt != __bkt || __is_bucket_begin)) 1900 _M_buckets[__n_bkt] = __prev_n; 1901 __prev_n->_M_nxt = __n; 1902 return iterator(__n); 1903 } 1904 1905 template<typename _Key, typename _Value, 1906 typename _Alloc, typename _ExtractKey, typename _Equal, 1907 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1908 typename _Traits> 1909 void 1910 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1911 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1912 clear() noexcept 1913 { 1914 this->_M_deallocate_nodes(_M_begin()); 1915 __builtin_memset(_M_buckets, 0, _M_bucket_count * sizeof(__bucket_type)); 1916 _M_element_count = 0; 1917 _M_before_begin._M_nxt = nullptr; 1918 } 1919 1920 template<typename _Key, typename _Value, 1921 typename _Alloc, typename _ExtractKey, typename _Equal, 1922 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1923 typename _Traits> 1924 void 1925 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1926 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1927 rehash(size_type __n) 1928 { 1929 const __rehash_state& __saved_state = _M_rehash_policy._M_state(); 1930 std::size_t __buckets 1931 = std::max(_M_rehash_policy._M_bkt_for_elements(_M_element_count + 1), 1932 __n); 1933 __buckets = _M_rehash_policy._M_next_bkt(__buckets); 1934 1935 if (__buckets != _M_bucket_count) 1936 _M_rehash(__buckets, __saved_state); 1937 else 1938 // No rehash, restore previous state to keep a consistent state. 1939 _M_rehash_policy._M_reset(__saved_state); 1940 } 1941 1942 template<typename _Key, typename _Value, 1943 typename _Alloc, typename _ExtractKey, typename _Equal, 1944 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1945 typename _Traits> 1946 void 1947 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1948 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1949 _M_rehash(size_type __n, const __rehash_state& __state) 1950 { 1951 __try 1952 { 1953 _M_rehash_aux(__n, __unique_keys()); 1954 } 1955 __catch(...) 1956 { 1957 // A failure here means that buckets allocation failed. We only 1958 // have to restore hash policy previous state. 1959 _M_rehash_policy._M_reset(__state); 1960 __throw_exception_again; 1961 } 1962 } 1963 1964 // Rehash when there is no equivalent elements. 1965 template<typename _Key, typename _Value, 1966 typename _Alloc, typename _ExtractKey, typename _Equal, 1967 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 1968 typename _Traits> 1969 void 1970 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1971 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 1972 _M_rehash_aux(size_type __n, std::true_type) 1973 { 1974 __bucket_type* __new_buckets = _M_allocate_buckets(__n); 1975 __node_type* __p = _M_begin(); 1976 _M_before_begin._M_nxt = nullptr; 1977 std::size_t __bbegin_bkt = 0; 1978 while (__p) 1979 { 1980 __node_type* __next = __p->_M_next(); 1981 std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n); 1982 if (!__new_buckets[__bkt]) 1983 { 1984 __p->_M_nxt = _M_before_begin._M_nxt; 1985 _M_before_begin._M_nxt = __p; 1986 __new_buckets[__bkt] = &_M_before_begin; 1987 if (__p->_M_nxt) 1988 __new_buckets[__bbegin_bkt] = __p; 1989 __bbegin_bkt = __bkt; 1990 } 1991 else 1992 { 1993 __p->_M_nxt = __new_buckets[__bkt]->_M_nxt; 1994 __new_buckets[__bkt]->_M_nxt = __p; 1995 } 1996 __p = __next; 1997 } 1998 1999 _M_deallocate_buckets(); 2000 _M_bucket_count = __n; 2001 _M_buckets = __new_buckets; 2002 } 2003 2004 // Rehash when there can be equivalent elements, preserve their relative 2005 // order. 2006 template<typename _Key, typename _Value, 2007 typename _Alloc, typename _ExtractKey, typename _Equal, 2008 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 2009 typename _Traits> 2010 void 2011 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 2012 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 2013 _M_rehash_aux(size_type __n, std::false_type) 2014 { 2015 __bucket_type* __new_buckets = _M_allocate_buckets(__n); 2016 2017 __node_type* __p = _M_begin(); 2018 _M_before_begin._M_nxt = nullptr; 2019 std::size_t __bbegin_bkt = 0; 2020 std::size_t __prev_bkt = 0; 2021 __node_type* __prev_p = nullptr; 2022 bool __check_bucket = false; 2023 2024 while (__p) 2025 { 2026 __node_type* __next = __p->_M_next(); 2027 std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n); 2028 2029 if (__prev_p && __prev_bkt == __bkt) 2030 { 2031 // Previous insert was already in this bucket, we insert after 2032 // the previously inserted one to preserve equivalent elements 2033 // relative order. 2034 __p->_M_nxt = __prev_p->_M_nxt; 2035 __prev_p->_M_nxt = __p; 2036 2037 // Inserting after a node in a bucket require to check that we 2038 // haven't change the bucket last node, in this case next 2039 // bucket containing its before begin node must be updated. We 2040 // schedule a check as soon as we move out of the sequence of 2041 // equivalent nodes to limit the number of checks. 2042 __check_bucket = true; 2043 } 2044 else 2045 { 2046 if (__check_bucket) 2047 { 2048 // Check if we shall update the next bucket because of 2049 // insertions into __prev_bkt bucket. 2050 if (__prev_p->_M_nxt) 2051 { 2052 std::size_t __next_bkt 2053 = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), 2054 __n); 2055 if (__next_bkt != __prev_bkt) 2056 __new_buckets[__next_bkt] = __prev_p; 2057 } 2058 __check_bucket = false; 2059 } 2060 2061 if (!__new_buckets[__bkt]) 2062 { 2063 __p->_M_nxt = _M_before_begin._M_nxt; 2064 _M_before_begin._M_nxt = __p; 2065 __new_buckets[__bkt] = &_M_before_begin; 2066 if (__p->_M_nxt) 2067 __new_buckets[__bbegin_bkt] = __p; 2068 __bbegin_bkt = __bkt; 2069 } 2070 else 2071 { 2072 __p->_M_nxt = __new_buckets[__bkt]->_M_nxt; 2073 __new_buckets[__bkt]->_M_nxt = __p; 2074 } 2075 } 2076 __prev_p = __p; 2077 __prev_bkt = __bkt; 2078 __p = __next; 2079 } 2080 2081 if (__check_bucket && __prev_p->_M_nxt) 2082 { 2083 std::size_t __next_bkt 2084 = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), __n); 2085 if (__next_bkt != __prev_bkt) 2086 __new_buckets[__next_bkt] = __prev_p; 2087 } 2088 2089 _M_deallocate_buckets(); 2090 _M_bucket_count = __n; 2091 _M_buckets = __new_buckets; 2092 } 2093 2094_GLIBCXX_END_NAMESPACE_VERSION 2095} // namespace std 2096 2097#endif // _HASHTABLE_H 2098