1 // Internal policy header for unordered_set and unordered_map -*- C++ -*- 2 3 // Copyright (C) 2010-2019 Free Software Foundation, Inc. 4 // 5 // This file is part of the GNU ISO C++ Library. This library is free 6 // software; you can redistribute it and/or modify it under the 7 // terms of the GNU General Public License as published by the 8 // Free Software Foundation; either version 3, or (at your option) 9 // any later version. 10 11 // This library is distributed in the hope that it will be useful, 12 // but WITHOUT ANY WARRANTY; without even the implied warranty of 13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 // GNU General Public License for more details. 15 16 // Under Section 7 of GPL version 3, you are granted additional 17 // permissions described in the GCC Runtime Library Exception, version 18 // 3.1, as published by the Free Software Foundation. 19 20 // You should have received a copy of the GNU General Public License and 21 // a copy of the GCC Runtime Library Exception along with this program; 22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 // <http://www.gnu.org/licenses/>. 24 25 /** @file bits/hashtable_policy.h 26 * This is an internal header file, included by other library headers. 27 * Do not attempt to use it directly. 28 * @headername{unordered_map,unordered_set} 29 */ 30 31 #ifndef _HASHTABLE_POLICY_H 32 #define _HASHTABLE_POLICY_H 1 33 34 #include <tuple> // for std::tuple, std::forward_as_tuple 35 #include <limits> // for std::numeric_limits 36 #include <bits/stl_algobase.h> // for std::min. 37 38 namespace std _GLIBCXX_VISIBILITY(default) 39 { 40 _GLIBCXX_BEGIN_NAMESPACE_VERSION 41 42 template<typename _Key, typename _Value, typename _Alloc, 43 typename _ExtractKey, typename _Equal, 44 typename _H1, typename _H2, typename _Hash, 45 typename _RehashPolicy, typename _Traits> 46 class _Hashtable; 47 48 namespace __detail 49 { 50 /** 51 * @defgroup hashtable-detail Base and Implementation Classes 52 * @ingroup unordered_associative_containers 53 * @{ 54 */ 55 template<typename _Key, typename _Value, 56 typename _ExtractKey, typename _Equal, 57 typename _H1, typename _H2, typename _Hash, typename _Traits> 58 struct _Hashtable_base; 59 60 // Helper function: return distance(first, last) for forward 61 // iterators, or 0/1 for input iterators. 62 template<class _Iterator> 63 inline typename std::iterator_traits<_Iterator>::difference_type 64 __distance_fw(_Iterator __first, _Iterator __last, 65 std::input_iterator_tag) 66 { return __first != __last ? 1 : 0; } 67 68 template<class _Iterator> 69 inline typename std::iterator_traits<_Iterator>::difference_type 70 __distance_fw(_Iterator __first, _Iterator __last, 71 std::forward_iterator_tag) 72 { return std::distance(__first, __last); } 73 74 template<class _Iterator> 75 inline typename std::iterator_traits<_Iterator>::difference_type 76 __distance_fw(_Iterator __first, _Iterator __last) 77 { return __distance_fw(__first, __last, 78 std::__iterator_category(__first)); } 79 80 struct _Identity 81 { 82 template<typename _Tp> 83 _Tp&& 84 operator()(_Tp&& __x) const 85 { return std::forward<_Tp>(__x); } 86 }; 87 88 struct _Select1st 89 { 90 template<typename _Tp> 91 auto 92 operator()(_Tp&& __x) const 93 -> decltype(std::get<0>(std::forward<_Tp>(__x))) 94 { return std::get<0>(std::forward<_Tp>(__x)); } 95 }; 96 97 template<typename _NodeAlloc> 98 struct _Hashtable_alloc; 99 100 // Functor recycling a pool of nodes and using allocation once the pool is 101 // empty. 102 template<typename _NodeAlloc> 103 struct _ReuseOrAllocNode 104 { 105 private: 106 using __node_alloc_type = _NodeAlloc; 107 using __hashtable_alloc = _Hashtable_alloc<__node_alloc_type>; 108 using __node_alloc_traits = 109 typename __hashtable_alloc::__node_alloc_traits; 110 using __node_type = typename __hashtable_alloc::__node_type; 111 112 public: 113 _ReuseOrAllocNode(__node_type* __nodes, __hashtable_alloc& __h) 114 : _M_nodes(__nodes), _M_h(__h) { } 115 _ReuseOrAllocNode(const _ReuseOrAllocNode&) = delete; 116 117 ~_ReuseOrAllocNode() 118 { _M_h._M_deallocate_nodes(_M_nodes); } 119 120 template<typename _Arg> 121 __node_type* 122 operator()(_Arg&& __arg) const 123 { 124 if (_M_nodes) 125 { 126 __node_type* __node = _M_nodes; 127 _M_nodes = _M_nodes->_M_next(); 128 __node->_M_nxt = nullptr; 129 auto& __a = _M_h._M_node_allocator(); 130 __node_alloc_traits::destroy(__a, __node->_M_valptr()); 131 __try 132 { 133 __node_alloc_traits::construct(__a, __node->_M_valptr(), 134 std::forward<_Arg>(__arg)); 135 } 136 __catch(...) 137 { 138 _M_h._M_deallocate_node_ptr(__node); 139 __throw_exception_again; 140 } 141 return __node; 142 } 143 return _M_h._M_allocate_node(std::forward<_Arg>(__arg)); 144 } 145 146 private: 147 mutable __node_type* _M_nodes; 148 __hashtable_alloc& _M_h; 149 }; 150 151 // Functor similar to the previous one but without any pool of nodes to 152 // recycle. 153 template<typename _NodeAlloc> 154 struct _AllocNode 155 { 156 private: 157 using __hashtable_alloc = _Hashtable_alloc<_NodeAlloc>; 158 using __node_type = typename __hashtable_alloc::__node_type; 159 160 public: 161 _AllocNode(__hashtable_alloc& __h) 162 : _M_h(__h) { } 163 164 template<typename _Arg> 165 __node_type* 166 operator()(_Arg&& __arg) const 167 { return _M_h._M_allocate_node(std::forward<_Arg>(__arg)); } 168 169 private: 170 __hashtable_alloc& _M_h; 171 }; 172 173 // Auxiliary types used for all instantiations of _Hashtable nodes 174 // and iterators. 175 176 /** 177 * struct _Hashtable_traits 178 * 179 * Important traits for hash tables. 180 * 181 * @tparam _Cache_hash_code Boolean value. True if the value of 182 * the hash function is stored along with the value. This is a 183 * time-space tradeoff. Storing it may improve lookup speed by 184 * reducing the number of times we need to call the _Equal 185 * function. 186 * 187 * @tparam _Constant_iterators Boolean value. True if iterator and 188 * const_iterator are both constant iterator types. This is true 189 * for unordered_set and unordered_multiset, false for 190 * unordered_map and unordered_multimap. 191 * 192 * @tparam _Unique_keys Boolean value. True if the return value 193 * of _Hashtable::count(k) is always at most one, false if it may 194 * be an arbitrary number. This is true for unordered_set and 195 * unordered_map, false for unordered_multiset and 196 * unordered_multimap. 197 */ 198 template<bool _Cache_hash_code, bool _Constant_iterators, bool _Unique_keys> 199 struct _Hashtable_traits 200 { 201 using __hash_cached = __bool_constant<_Cache_hash_code>; 202 using __constant_iterators = __bool_constant<_Constant_iterators>; 203 using __unique_keys = __bool_constant<_Unique_keys>; 204 }; 205 206 /** 207 * struct _Hash_node_base 208 * 209 * Nodes, used to wrap elements stored in the hash table. A policy 210 * template parameter of class template _Hashtable controls whether 211 * nodes also store a hash code. In some cases (e.g. strings) this 212 * may be a performance win. 213 */ 214 struct _Hash_node_base 215 { 216 _Hash_node_base* _M_nxt; 217 218 _Hash_node_base() noexcept : _M_nxt() { } 219 220 _Hash_node_base(_Hash_node_base* __next) noexcept : _M_nxt(__next) { } 221 }; 222 223 /** 224 * struct _Hash_node_value_base 225 * 226 * Node type with the value to store. 227 */ 228 template<typename _Value> 229 struct _Hash_node_value_base : _Hash_node_base 230 { 231 typedef _Value value_type; 232 233 __gnu_cxx::__aligned_buffer<_Value> _M_storage; 234 235 _Value* 236 _M_valptr() noexcept 237 { return _M_storage._M_ptr(); } 238 239 const _Value* 240 _M_valptr() const noexcept 241 { return _M_storage._M_ptr(); } 242 243 _Value& 244 _M_v() noexcept 245 { return *_M_valptr(); } 246 247 const _Value& 248 _M_v() const noexcept 249 { return *_M_valptr(); } 250 }; 251 252 /** 253 * Primary template struct _Hash_node. 254 */ 255 template<typename _Value, bool _Cache_hash_code> 256 struct _Hash_node; 257 258 /** 259 * Specialization for nodes with caches, struct _Hash_node. 260 * 261 * Base class is __detail::_Hash_node_value_base. 262 */ 263 template<typename _Value> 264 struct _Hash_node<_Value, true> : _Hash_node_value_base<_Value> 265 { 266 std::size_t _M_hash_code; 267 268 _Hash_node* 269 _M_next() const noexcept 270 { return static_cast<_Hash_node*>(this->_M_nxt); } 271 }; 272 273 /** 274 * Specialization for nodes without caches, struct _Hash_node. 275 * 276 * Base class is __detail::_Hash_node_value_base. 277 */ 278 template<typename _Value> 279 struct _Hash_node<_Value, false> : _Hash_node_value_base<_Value> 280 { 281 _Hash_node* 282 _M_next() const noexcept 283 { return static_cast<_Hash_node*>(this->_M_nxt); } 284 }; 285 286 /// Base class for node iterators. 287 template<typename _Value, bool _Cache_hash_code> 288 struct _Node_iterator_base 289 { 290 using __node_type = _Hash_node<_Value, _Cache_hash_code>; 291 292 __node_type* _M_cur; 293 294 _Node_iterator_base(__node_type* __p) noexcept 295 : _M_cur(__p) { } 296 297 void 298 _M_incr() noexcept 299 { _M_cur = _M_cur->_M_next(); } 300 }; 301 302 template<typename _Value, bool _Cache_hash_code> 303 inline bool 304 operator==(const _Node_iterator_base<_Value, _Cache_hash_code>& __x, 305 const _Node_iterator_base<_Value, _Cache_hash_code >& __y) 306 noexcept 307 { return __x._M_cur == __y._M_cur; } 308 309 template<typename _Value, bool _Cache_hash_code> 310 inline bool 311 operator!=(const _Node_iterator_base<_Value, _Cache_hash_code>& __x, 312 const _Node_iterator_base<_Value, _Cache_hash_code>& __y) 313 noexcept 314 { return __x._M_cur != __y._M_cur; } 315 316 /// Node iterators, used to iterate through all the hashtable. 317 template<typename _Value, bool __constant_iterators, bool __cache> 318 struct _Node_iterator 319 : public _Node_iterator_base<_Value, __cache> 320 { 321 private: 322 using __base_type = _Node_iterator_base<_Value, __cache>; 323 using __node_type = typename __base_type::__node_type; 324 325 public: 326 typedef _Value value_type; 327 typedef std::ptrdiff_t difference_type; 328 typedef std::forward_iterator_tag iterator_category; 329 330 using pointer = typename std::conditional<__constant_iterators, 331 const _Value*, _Value*>::type; 332 333 using reference = typename std::conditional<__constant_iterators, 334 const _Value&, _Value&>::type; 335 336 _Node_iterator() noexcept 337 : __base_type(0) { } 338 339 explicit 340 _Node_iterator(__node_type* __p) noexcept 341 : __base_type(__p) { } 342 343 reference 344 operator*() const noexcept 345 { return this->_M_cur->_M_v(); } 346 347 pointer 348 operator->() const noexcept 349 { return this->_M_cur->_M_valptr(); } 350 351 _Node_iterator& 352 operator++() noexcept 353 { 354 this->_M_incr(); 355 return *this; 356 } 357 358 _Node_iterator 359 operator++(int) noexcept 360 { 361 _Node_iterator __tmp(*this); 362 this->_M_incr(); 363 return __tmp; 364 } 365 }; 366 367 /// Node const_iterators, used to iterate through all the hashtable. 368 template<typename _Value, bool __constant_iterators, bool __cache> 369 struct _Node_const_iterator 370 : public _Node_iterator_base<_Value, __cache> 371 { 372 private: 373 using __base_type = _Node_iterator_base<_Value, __cache>; 374 using __node_type = typename __base_type::__node_type; 375 376 public: 377 typedef _Value value_type; 378 typedef std::ptrdiff_t difference_type; 379 typedef std::forward_iterator_tag iterator_category; 380 381 typedef const _Value* pointer; 382 typedef const _Value& reference; 383 384 _Node_const_iterator() noexcept 385 : __base_type(0) { } 386 387 explicit 388 _Node_const_iterator(__node_type* __p) noexcept 389 : __base_type(__p) { } 390 391 _Node_const_iterator(const _Node_iterator<_Value, __constant_iterators, 392 __cache>& __x) noexcept 393 : __base_type(__x._M_cur) { } 394 395 reference 396 operator*() const noexcept 397 { return this->_M_cur->_M_v(); } 398 399 pointer 400 operator->() const noexcept 401 { return this->_M_cur->_M_valptr(); } 402 403 _Node_const_iterator& 404 operator++() noexcept 405 { 406 this->_M_incr(); 407 return *this; 408 } 409 410 _Node_const_iterator 411 operator++(int) noexcept 412 { 413 _Node_const_iterator __tmp(*this); 414 this->_M_incr(); 415 return __tmp; 416 } 417 }; 418 419 // Many of class template _Hashtable's template parameters are policy 420 // classes. These are defaults for the policies. 421 422 /// Default range hashing function: use division to fold a large number 423 /// into the range [0, N). 424 struct _Mod_range_hashing 425 { 426 typedef std::size_t first_argument_type; 427 typedef std::size_t second_argument_type; 428 typedef std::size_t result_type; 429 430 result_type 431 operator()(first_argument_type __num, 432 second_argument_type __den) const noexcept 433 { return __num % __den; } 434 }; 435 436 /// Default ranged hash function H. In principle it should be a 437 /// function object composed from objects of type H1 and H2 such that 438 /// h(k, N) = h2(h1(k), N), but that would mean making extra copies of 439 /// h1 and h2. So instead we'll just use a tag to tell class template 440 /// hashtable to do that composition. 441 struct _Default_ranged_hash { }; 442 443 /// Default value for rehash policy. Bucket size is (usually) the 444 /// smallest prime that keeps the load factor small enough. 445 struct _Prime_rehash_policy 446 { 447 using __has_load_factor = std::true_type; 448 449 _Prime_rehash_policy(float __z = 1.0) noexcept 450 : _M_max_load_factor(__z), _M_next_resize(0) { } 451 452 float 453 max_load_factor() const noexcept 454 { return _M_max_load_factor; } 455 456 // Return a bucket size no smaller than n. 457 std::size_t 458 _M_next_bkt(std::size_t __n) const; 459 460 // Return a bucket count appropriate for n elements 461 std::size_t 462 _M_bkt_for_elements(std::size_t __n) const 463 { return __builtin_ceil(__n / (long double)_M_max_load_factor); } 464 465 // __n_bkt is current bucket count, __n_elt is current element count, 466 // and __n_ins is number of elements to be inserted. Do we need to 467 // increase bucket count? If so, return make_pair(true, n), where n 468 // is the new bucket count. If not, return make_pair(false, 0). 469 std::pair<bool, std::size_t> 470 _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, 471 std::size_t __n_ins) const; 472 473 typedef std::size_t _State; 474 475 _State 476 _M_state() const 477 { return _M_next_resize; } 478 479 void 480 _M_reset() noexcept 481 { _M_next_resize = 0; } 482 483 void 484 _M_reset(_State __state) 485 { _M_next_resize = __state; } 486 487 static const std::size_t _S_growth_factor = 2; 488 489 float _M_max_load_factor; 490 mutable std::size_t _M_next_resize; 491 }; 492 493 /// Range hashing function assuming that second arg is a power of 2. 494 struct _Mask_range_hashing 495 { 496 typedef std::size_t first_argument_type; 497 typedef std::size_t second_argument_type; 498 typedef std::size_t result_type; 499 500 result_type 501 operator()(first_argument_type __num, 502 second_argument_type __den) const noexcept 503 { return __num & (__den - 1); } 504 }; 505 506 /// Compute closest power of 2 not less than __n 507 inline std::size_t 508 __clp2(std::size_t __n) noexcept 509 { 510 // Equivalent to return __n ? std::ceil2(__n) : 0; 511 if (__n < 2) 512 return __n; 513 const unsigned __lz = sizeof(size_t) > sizeof(long) 514 ? __builtin_clzll(__n - 1ull) 515 : __builtin_clzl(__n - 1ul); 516 // Doing two shifts avoids undefined behaviour when __lz == 0. 517 return (size_t(1) << (numeric_limits<size_t>::digits - __lz - 1)) << 1; 518 } 519 520 /// Rehash policy providing power of 2 bucket numbers. Avoids modulo 521 /// operations. 522 struct _Power2_rehash_policy 523 { 524 using __has_load_factor = std::true_type; 525 526 _Power2_rehash_policy(float __z = 1.0) noexcept 527 : _M_max_load_factor(__z), _M_next_resize(0) { } 528 529 float 530 max_load_factor() const noexcept 531 { return _M_max_load_factor; } 532 533 // Return a bucket size no smaller than n (as long as n is not above the 534 // highest power of 2). 535 std::size_t 536 _M_next_bkt(std::size_t __n) noexcept 537 { 538 const auto __max_width = std::min<size_t>(sizeof(size_t), 8); 539 const auto __max_bkt = size_t(1) << (__max_width * __CHAR_BIT__ - 1); 540 std::size_t __res = __clp2(__n); 541 542 if (__res == __n) 543 __res <<= 1; 544 545 if (__res == 0) 546 __res = __max_bkt; 547 548 if (__res == __max_bkt) 549 // Set next resize to the max value so that we never try to rehash again 550 // as we already reach the biggest possible bucket number. 551 // Note that it might result in max_load_factor not being respected. 552 _M_next_resize = std::size_t(-1); 553 else 554 _M_next_resize 555 = __builtin_ceil(__res * (long double)_M_max_load_factor); 556 557 return __res; 558 } 559 560 // Return a bucket count appropriate for n elements 561 std::size_t 562 _M_bkt_for_elements(std::size_t __n) const noexcept 563 { return __builtin_ceil(__n / (long double)_M_max_load_factor); } 564 565 // __n_bkt is current bucket count, __n_elt is current element count, 566 // and __n_ins is number of elements to be inserted. Do we need to 567 // increase bucket count? If so, return make_pair(true, n), where n 568 // is the new bucket count. If not, return make_pair(false, 0). 569 std::pair<bool, std::size_t> 570 _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, 571 std::size_t __n_ins) noexcept 572 { 573 if (__n_elt + __n_ins >= _M_next_resize) 574 { 575 long double __min_bkts = (__n_elt + __n_ins) 576 / (long double)_M_max_load_factor; 577 if (__min_bkts >= __n_bkt) 578 return std::make_pair(true, 579 _M_next_bkt(std::max<std::size_t>(__builtin_floor(__min_bkts) + 1, 580 __n_bkt * _S_growth_factor))); 581 582 _M_next_resize 583 = __builtin_floor(__n_bkt * (long double)_M_max_load_factor); 584 return std::make_pair(false, 0); 585 } 586 else 587 return std::make_pair(false, 0); 588 } 589 590 typedef std::size_t _State; 591 592 _State 593 _M_state() const noexcept 594 { return _M_next_resize; } 595 596 void 597 _M_reset() noexcept 598 { _M_next_resize = 0; } 599 600 void 601 _M_reset(_State __state) noexcept 602 { _M_next_resize = __state; } 603 604 static const std::size_t _S_growth_factor = 2; 605 606 float _M_max_load_factor; 607 std::size_t _M_next_resize; 608 }; 609 610 // Base classes for std::_Hashtable. We define these base classes 611 // because in some cases we want to do different things depending on 612 // the value of a policy class. In some cases the policy class 613 // affects which member functions and nested typedefs are defined; 614 // we handle that by specializing base class templates. Several of 615 // the base class templates need to access other members of class 616 // template _Hashtable, so we use a variant of the "Curiously 617 // Recurring Template Pattern" (CRTP) technique. 618 619 /** 620 * Primary class template _Map_base. 621 * 622 * If the hashtable has a value type of the form pair<T1, T2> and a 623 * key extraction policy (_ExtractKey) that returns the first part 624 * of the pair, the hashtable gets a mapped_type typedef. If it 625 * satisfies those criteria and also has unique keys, then it also 626 * gets an operator[]. 627 */ 628 template<typename _Key, typename _Value, typename _Alloc, 629 typename _ExtractKey, typename _Equal, 630 typename _H1, typename _H2, typename _Hash, 631 typename _RehashPolicy, typename _Traits, 632 bool _Unique_keys = _Traits::__unique_keys::value> 633 struct _Map_base { }; 634 635 /// Partial specialization, __unique_keys set to false. 636 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 637 typename _H1, typename _H2, typename _Hash, 638 typename _RehashPolicy, typename _Traits> 639 struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 640 _H1, _H2, _Hash, _RehashPolicy, _Traits, false> 641 { 642 using mapped_type = typename std::tuple_element<1, _Pair>::type; 643 }; 644 645 /// Partial specialization, __unique_keys set to true. 646 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 647 typename _H1, typename _H2, typename _Hash, 648 typename _RehashPolicy, typename _Traits> 649 struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 650 _H1, _H2, _Hash, _RehashPolicy, _Traits, true> 651 { 652 private: 653 using __hashtable_base = __detail::_Hashtable_base<_Key, _Pair, 654 _Select1st, 655 _Equal, _H1, _H2, _Hash, 656 _Traits>; 657 658 using __hashtable = _Hashtable<_Key, _Pair, _Alloc, 659 _Select1st, _Equal, 660 _H1, _H2, _Hash, _RehashPolicy, _Traits>; 661 662 using __hash_code = typename __hashtable_base::__hash_code; 663 using __node_type = typename __hashtable_base::__node_type; 664 665 public: 666 using key_type = typename __hashtable_base::key_type; 667 using iterator = typename __hashtable_base::iterator; 668 using mapped_type = typename std::tuple_element<1, _Pair>::type; 669 670 mapped_type& 671 operator[](const key_type& __k); 672 673 mapped_type& 674 operator[](key_type&& __k); 675 676 // _GLIBCXX_RESOLVE_LIB_DEFECTS 677 // DR 761. unordered_map needs an at() member function. 678 mapped_type& 679 at(const key_type& __k); 680 681 const mapped_type& 682 at(const key_type& __k) const; 683 }; 684 685 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 686 typename _H1, typename _H2, typename _Hash, 687 typename _RehashPolicy, typename _Traits> 688 auto 689 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 690 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 691 operator[](const key_type& __k) 692 -> mapped_type& 693 { 694 __hashtable* __h = static_cast<__hashtable*>(this); 695 __hash_code __code = __h->_M_hash_code(__k); 696 std::size_t __n = __h->_M_bucket_index(__k, __code); 697 __node_type* __p = __h->_M_find_node(__n, __k, __code); 698 699 if (!__p) 700 { 701 __p = __h->_M_allocate_node(std::piecewise_construct, 702 std::tuple<const key_type&>(__k), 703 std::tuple<>()); 704 return __h->_M_insert_unique_node(__n, __code, __p)->second; 705 } 706 707 return __p->_M_v().second; 708 } 709 710 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 711 typename _H1, typename _H2, typename _Hash, 712 typename _RehashPolicy, typename _Traits> 713 auto 714 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 715 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 716 operator[](key_type&& __k) 717 -> mapped_type& 718 { 719 __hashtable* __h = static_cast<__hashtable*>(this); 720 __hash_code __code = __h->_M_hash_code(__k); 721 std::size_t __n = __h->_M_bucket_index(__k, __code); 722 __node_type* __p = __h->_M_find_node(__n, __k, __code); 723 724 if (!__p) 725 { 726 __p = __h->_M_allocate_node(std::piecewise_construct, 727 std::forward_as_tuple(std::move(__k)), 728 std::tuple<>()); 729 return __h->_M_insert_unique_node(__n, __code, __p)->second; 730 } 731 732 return __p->_M_v().second; 733 } 734 735 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 736 typename _H1, typename _H2, typename _Hash, 737 typename _RehashPolicy, typename _Traits> 738 auto 739 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 740 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 741 at(const key_type& __k) 742 -> mapped_type& 743 { 744 __hashtable* __h = static_cast<__hashtable*>(this); 745 __hash_code __code = __h->_M_hash_code(__k); 746 std::size_t __n = __h->_M_bucket_index(__k, __code); 747 __node_type* __p = __h->_M_find_node(__n, __k, __code); 748 749 if (!__p) 750 __throw_out_of_range(__N("_Map_base::at")); 751 return __p->_M_v().second; 752 } 753 754 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 755 typename _H1, typename _H2, typename _Hash, 756 typename _RehashPolicy, typename _Traits> 757 auto 758 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 759 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 760 at(const key_type& __k) const 761 -> const mapped_type& 762 { 763 const __hashtable* __h = static_cast<const __hashtable*>(this); 764 __hash_code __code = __h->_M_hash_code(__k); 765 std::size_t __n = __h->_M_bucket_index(__k, __code); 766 __node_type* __p = __h->_M_find_node(__n, __k, __code); 767 768 if (!__p) 769 __throw_out_of_range(__N("_Map_base::at")); 770 return __p->_M_v().second; 771 } 772 773 /** 774 * Primary class template _Insert_base. 775 * 776 * Defines @c insert member functions appropriate to all _Hashtables. 777 */ 778 template<typename _Key, typename _Value, typename _Alloc, 779 typename _ExtractKey, typename _Equal, 780 typename _H1, typename _H2, typename _Hash, 781 typename _RehashPolicy, typename _Traits> 782 struct _Insert_base 783 { 784 protected: 785 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, 786 _Equal, _H1, _H2, _Hash, 787 _RehashPolicy, _Traits>; 788 789 using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey, 790 _Equal, _H1, _H2, _Hash, 791 _Traits>; 792 793 using value_type = typename __hashtable_base::value_type; 794 using iterator = typename __hashtable_base::iterator; 795 using const_iterator = typename __hashtable_base::const_iterator; 796 using size_type = typename __hashtable_base::size_type; 797 798 using __unique_keys = typename __hashtable_base::__unique_keys; 799 using __ireturn_type = typename __hashtable_base::__ireturn_type; 800 using __node_type = _Hash_node<_Value, _Traits::__hash_cached::value>; 801 using __node_alloc_type = __alloc_rebind<_Alloc, __node_type>; 802 using __node_gen_type = _AllocNode<__node_alloc_type>; 803 804 __hashtable& 805 _M_conjure_hashtable() 806 { return *(static_cast<__hashtable*>(this)); } 807 808 template<typename _InputIterator, typename _NodeGetter> 809 void 810 _M_insert_range(_InputIterator __first, _InputIterator __last, 811 const _NodeGetter&, true_type); 812 813 template<typename _InputIterator, typename _NodeGetter> 814 void 815 _M_insert_range(_InputIterator __first, _InputIterator __last, 816 const _NodeGetter&, false_type); 817 818 public: 819 __ireturn_type 820 insert(const value_type& __v) 821 { 822 __hashtable& __h = _M_conjure_hashtable(); 823 __node_gen_type __node_gen(__h); 824 return __h._M_insert(__v, __node_gen, __unique_keys()); 825 } 826 827 iterator 828 insert(const_iterator __hint, const value_type& __v) 829 { 830 __hashtable& __h = _M_conjure_hashtable(); 831 __node_gen_type __node_gen(__h); 832 return __h._M_insert(__hint, __v, __node_gen, __unique_keys()); 833 } 834 835 void 836 insert(initializer_list<value_type> __l) 837 { this->insert(__l.begin(), __l.end()); } 838 839 template<typename _InputIterator> 840 void 841 insert(_InputIterator __first, _InputIterator __last) 842 { 843 __hashtable& __h = _M_conjure_hashtable(); 844 __node_gen_type __node_gen(__h); 845 return _M_insert_range(__first, __last, __node_gen, __unique_keys()); 846 } 847 }; 848 849 template<typename _Key, typename _Value, typename _Alloc, 850 typename _ExtractKey, typename _Equal, 851 typename _H1, typename _H2, typename _Hash, 852 typename _RehashPolicy, typename _Traits> 853 template<typename _InputIterator, typename _NodeGetter> 854 void 855 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, 856 _RehashPolicy, _Traits>:: 857 _M_insert_range(_InputIterator __first, _InputIterator __last, 858 const _NodeGetter& __node_gen, true_type) 859 { 860 size_type __n_elt = __detail::__distance_fw(__first, __last); 861 if (__n_elt == 0) 862 return; 863 864 __hashtable& __h = _M_conjure_hashtable(); 865 for (; __first != __last; ++__first) 866 { 867 if (__h._M_insert(*__first, __node_gen, __unique_keys(), 868 __n_elt).second) 869 __n_elt = 1; 870 else if (__n_elt != 1) 871 --__n_elt; 872 } 873 } 874 875 template<typename _Key, typename _Value, typename _Alloc, 876 typename _ExtractKey, typename _Equal, 877 typename _H1, typename _H2, typename _Hash, 878 typename _RehashPolicy, typename _Traits> 879 template<typename _InputIterator, typename _NodeGetter> 880 void 881 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, 882 _RehashPolicy, _Traits>:: 883 _M_insert_range(_InputIterator __first, _InputIterator __last, 884 const _NodeGetter& __node_gen, false_type) 885 { 886 using __rehash_type = typename __hashtable::__rehash_type; 887 using __rehash_state = typename __hashtable::__rehash_state; 888 using pair_type = std::pair<bool, std::size_t>; 889 890 size_type __n_elt = __detail::__distance_fw(__first, __last); 891 if (__n_elt == 0) 892 return; 893 894 __hashtable& __h = _M_conjure_hashtable(); 895 __rehash_type& __rehash = __h._M_rehash_policy; 896 const __rehash_state& __saved_state = __rehash._M_state(); 897 pair_type __do_rehash = __rehash._M_need_rehash(__h._M_bucket_count, 898 __h._M_element_count, 899 __n_elt); 900 901 if (__do_rehash.first) 902 __h._M_rehash(__do_rehash.second, __saved_state); 903 904 for (; __first != __last; ++__first) 905 __h._M_insert(*__first, __node_gen, __unique_keys()); 906 } 907 908 /** 909 * Primary class template _Insert. 910 * 911 * Defines @c insert member functions that depend on _Hashtable policies, 912 * via partial specializations. 913 */ 914 template<typename _Key, typename _Value, typename _Alloc, 915 typename _ExtractKey, typename _Equal, 916 typename _H1, typename _H2, typename _Hash, 917 typename _RehashPolicy, typename _Traits, 918 bool _Constant_iterators = _Traits::__constant_iterators::value> 919 struct _Insert; 920 921 /// Specialization. 922 template<typename _Key, typename _Value, typename _Alloc, 923 typename _ExtractKey, typename _Equal, 924 typename _H1, typename _H2, typename _Hash, 925 typename _RehashPolicy, typename _Traits> 926 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, 927 _RehashPolicy, _Traits, true> 928 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 929 _H1, _H2, _Hash, _RehashPolicy, _Traits> 930 { 931 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey, 932 _Equal, _H1, _H2, _Hash, 933 _RehashPolicy, _Traits>; 934 935 using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey, 936 _Equal, _H1, _H2, _Hash, 937 _Traits>; 938 939 using value_type = typename __base_type::value_type; 940 using iterator = typename __base_type::iterator; 941 using const_iterator = typename __base_type::const_iterator; 942 943 using __unique_keys = typename __base_type::__unique_keys; 944 using __ireturn_type = typename __hashtable_base::__ireturn_type; 945 using __hashtable = typename __base_type::__hashtable; 946 using __node_gen_type = typename __base_type::__node_gen_type; 947 948 using __base_type::insert; 949 950 __ireturn_type 951 insert(value_type&& __v) 952 { 953 __hashtable& __h = this->_M_conjure_hashtable(); 954 __node_gen_type __node_gen(__h); 955 return __h._M_insert(std::move(__v), __node_gen, __unique_keys()); 956 } 957 958 iterator 959 insert(const_iterator __hint, value_type&& __v) 960 { 961 __hashtable& __h = this->_M_conjure_hashtable(); 962 __node_gen_type __node_gen(__h); 963 return __h._M_insert(__hint, std::move(__v), __node_gen, 964 __unique_keys()); 965 } 966 }; 967 968 /// Specialization. 969 template<typename _Key, typename _Value, typename _Alloc, 970 typename _ExtractKey, typename _Equal, 971 typename _H1, typename _H2, typename _Hash, 972 typename _RehashPolicy, typename _Traits> 973 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, 974 _RehashPolicy, _Traits, false> 975 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 976 _H1, _H2, _Hash, _RehashPolicy, _Traits> 977 { 978 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey, 979 _Equal, _H1, _H2, _Hash, 980 _RehashPolicy, _Traits>; 981 using value_type = typename __base_type::value_type; 982 using iterator = typename __base_type::iterator; 983 using const_iterator = typename __base_type::const_iterator; 984 985 using __unique_keys = typename __base_type::__unique_keys; 986 using __hashtable = typename __base_type::__hashtable; 987 using __ireturn_type = typename __base_type::__ireturn_type; 988 989 using __base_type::insert; 990 991 template<typename _Pair> 992 using __is_cons = std::is_constructible<value_type, _Pair&&>; 993 994 template<typename _Pair> 995 using _IFcons = std::enable_if<__is_cons<_Pair>::value>; 996 997 template<typename _Pair> 998 using _IFconsp = typename _IFcons<_Pair>::type; 999 1000 template<typename _Pair, typename = _IFconsp<_Pair>> 1001 __ireturn_type 1002 insert(_Pair&& __v) 1003 { 1004 __hashtable& __h = this->_M_conjure_hashtable(); 1005 return __h._M_emplace(__unique_keys(), std::forward<_Pair>(__v)); 1006 } 1007 1008 template<typename _Pair, typename = _IFconsp<_Pair>> 1009 iterator 1010 insert(const_iterator __hint, _Pair&& __v) 1011 { 1012 __hashtable& __h = this->_M_conjure_hashtable(); 1013 return __h._M_emplace(__hint, __unique_keys(), 1014 std::forward<_Pair>(__v)); 1015 } 1016 }; 1017 1018 template<typename _Policy> 1019 using __has_load_factor = typename _Policy::__has_load_factor; 1020 1021 /** 1022 * Primary class template _Rehash_base. 1023 * 1024 * Give hashtable the max_load_factor functions and reserve iff the 1025 * rehash policy supports it. 1026 */ 1027 template<typename _Key, typename _Value, typename _Alloc, 1028 typename _ExtractKey, typename _Equal, 1029 typename _H1, typename _H2, typename _Hash, 1030 typename _RehashPolicy, typename _Traits, 1031 typename = 1032 __detected_or_t<std::false_type, __has_load_factor, _RehashPolicy>> 1033 struct _Rehash_base; 1034 1035 /// Specialization when rehash policy doesn't provide load factor management. 1036 template<typename _Key, typename _Value, typename _Alloc, 1037 typename _ExtractKey, typename _Equal, 1038 typename _H1, typename _H2, typename _Hash, 1039 typename _RehashPolicy, typename _Traits> 1040 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1041 _H1, _H2, _Hash, _RehashPolicy, _Traits, 1042 std::false_type> 1043 { 1044 }; 1045 1046 /// Specialization when rehash policy provide load factor management. 1047 template<typename _Key, typename _Value, typename _Alloc, 1048 typename _ExtractKey, typename _Equal, 1049 typename _H1, typename _H2, typename _Hash, 1050 typename _RehashPolicy, typename _Traits> 1051 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1052 _H1, _H2, _Hash, _RehashPolicy, _Traits, 1053 std::true_type> 1054 { 1055 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, 1056 _Equal, _H1, _H2, _Hash, 1057 _RehashPolicy, _Traits>; 1058 1059 float 1060 max_load_factor() const noexcept 1061 { 1062 const __hashtable* __this = static_cast<const __hashtable*>(this); 1063 return __this->__rehash_policy().max_load_factor(); 1064 } 1065 1066 void 1067 max_load_factor(float __z) 1068 { 1069 __hashtable* __this = static_cast<__hashtable*>(this); 1070 __this->__rehash_policy(_RehashPolicy(__z)); 1071 } 1072 1073 void 1074 reserve(std::size_t __n) 1075 { 1076 __hashtable* __this = static_cast<__hashtable*>(this); 1077 __this->rehash(__builtin_ceil(__n / max_load_factor())); 1078 } 1079 }; 1080 1081 /** 1082 * Primary class template _Hashtable_ebo_helper. 1083 * 1084 * Helper class using EBO when it is not forbidden (the type is not 1085 * final) and when it is worth it (the type is empty.) 1086 */ 1087 template<int _Nm, typename _Tp, 1088 bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)> 1089 struct _Hashtable_ebo_helper; 1090 1091 /// Specialization using EBO. 1092 template<int _Nm, typename _Tp> 1093 struct _Hashtable_ebo_helper<_Nm, _Tp, true> 1094 : private _Tp 1095 { 1096 _Hashtable_ebo_helper() = default; 1097 1098 template<typename _OtherTp> 1099 _Hashtable_ebo_helper(_OtherTp&& __tp) 1100 : _Tp(std::forward<_OtherTp>(__tp)) 1101 { } 1102 1103 static const _Tp& 1104 _S_cget(const _Hashtable_ebo_helper& __eboh) 1105 { return static_cast<const _Tp&>(__eboh); } 1106 1107 static _Tp& 1108 _S_get(_Hashtable_ebo_helper& __eboh) 1109 { return static_cast<_Tp&>(__eboh); } 1110 }; 1111 1112 /// Specialization not using EBO. 1113 template<int _Nm, typename _Tp> 1114 struct _Hashtable_ebo_helper<_Nm, _Tp, false> 1115 { 1116 _Hashtable_ebo_helper() = default; 1117 1118 template<typename _OtherTp> 1119 _Hashtable_ebo_helper(_OtherTp&& __tp) 1120 : _M_tp(std::forward<_OtherTp>(__tp)) 1121 { } 1122 1123 static const _Tp& 1124 _S_cget(const _Hashtable_ebo_helper& __eboh) 1125 { return __eboh._M_tp; } 1126 1127 static _Tp& 1128 _S_get(_Hashtable_ebo_helper& __eboh) 1129 { return __eboh._M_tp; } 1130 1131 private: 1132 _Tp _M_tp; 1133 }; 1134 1135 /** 1136 * Primary class template _Local_iterator_base. 1137 * 1138 * Base class for local iterators, used to iterate within a bucket 1139 * but not between buckets. 1140 */ 1141 template<typename _Key, typename _Value, typename _ExtractKey, 1142 typename _H1, typename _H2, typename _Hash, 1143 bool __cache_hash_code> 1144 struct _Local_iterator_base; 1145 1146 /** 1147 * Primary class template _Hash_code_base. 1148 * 1149 * Encapsulates two policy issues that aren't quite orthogonal. 1150 * (1) the difference between using a ranged hash function and using 1151 * the combination of a hash function and a range-hashing function. 1152 * In the former case we don't have such things as hash codes, so 1153 * we have a dummy type as placeholder. 1154 * (2) Whether or not we cache hash codes. Caching hash codes is 1155 * meaningless if we have a ranged hash function. 1156 * 1157 * We also put the key extraction objects here, for convenience. 1158 * Each specialization derives from one or more of the template 1159 * parameters to benefit from Ebo. This is important as this type 1160 * is inherited in some cases by the _Local_iterator_base type used 1161 * to implement local_iterator and const_local_iterator. As with 1162 * any iterator type we prefer to make it as small as possible. 1163 * 1164 * Primary template is unused except as a hook for specializations. 1165 */ 1166 template<typename _Key, typename _Value, typename _ExtractKey, 1167 typename _H1, typename _H2, typename _Hash, 1168 bool __cache_hash_code> 1169 struct _Hash_code_base; 1170 1171 /// Specialization: ranged hash function, no caching hash codes. H1 1172 /// and H2 are provided but ignored. We define a dummy hash code type. 1173 template<typename _Key, typename _Value, typename _ExtractKey, 1174 typename _H1, typename _H2, typename _Hash> 1175 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false> 1176 : private _Hashtable_ebo_helper<0, _ExtractKey>, 1177 private _Hashtable_ebo_helper<1, _Hash> 1178 { 1179 private: 1180 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>; 1181 using __ebo_hash = _Hashtable_ebo_helper<1, _Hash>; 1182 1183 protected: 1184 typedef void* __hash_code; 1185 typedef _Hash_node<_Value, false> __node_type; 1186 1187 // We need the default constructor for the local iterators and _Hashtable 1188 // default constructor. 1189 _Hash_code_base() = default; 1190 1191 _Hash_code_base(const _ExtractKey& __ex, const _H1&, const _H2&, 1192 const _Hash& __h) 1193 : __ebo_extract_key(__ex), __ebo_hash(__h) { } 1194 1195 __hash_code 1196 _M_hash_code(const _Key& __key) const 1197 { return 0; } 1198 1199 std::size_t 1200 _M_bucket_index(const _Key& __k, __hash_code, std::size_t __n) const 1201 { return _M_ranged_hash()(__k, __n); } 1202 1203 std::size_t 1204 _M_bucket_index(const __node_type* __p, std::size_t __n) const 1205 noexcept( noexcept(declval<const _Hash&>()(declval<const _Key&>(), 1206 (std::size_t)0)) ) 1207 { return _M_ranged_hash()(_M_extract()(__p->_M_v()), __n); } 1208 1209 void 1210 _M_store_code(__node_type*, __hash_code) const 1211 { } 1212 1213 void 1214 _M_copy_code(__node_type*, const __node_type*) const 1215 { } 1216 1217 void 1218 _M_swap(_Hash_code_base& __x) 1219 { 1220 std::swap(_M_extract(), __x._M_extract()); 1221 std::swap(_M_ranged_hash(), __x._M_ranged_hash()); 1222 } 1223 1224 const _ExtractKey& 1225 _M_extract() const { return __ebo_extract_key::_S_cget(*this); } 1226 1227 _ExtractKey& 1228 _M_extract() { return __ebo_extract_key::_S_get(*this); } 1229 1230 const _Hash& 1231 _M_ranged_hash() const { return __ebo_hash::_S_cget(*this); } 1232 1233 _Hash& 1234 _M_ranged_hash() { return __ebo_hash::_S_get(*this); } 1235 }; 1236 1237 // No specialization for ranged hash function while caching hash codes. 1238 // That combination is meaningless, and trying to do it is an error. 1239 1240 /// Specialization: ranged hash function, cache hash codes. This 1241 /// combination is meaningless, so we provide only a declaration 1242 /// and no definition. 1243 template<typename _Key, typename _Value, typename _ExtractKey, 1244 typename _H1, typename _H2, typename _Hash> 1245 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>; 1246 1247 /// Specialization: hash function and range-hashing function, no 1248 /// caching of hash codes. 1249 /// Provides typedef and accessor required by C++ 11. 1250 template<typename _Key, typename _Value, typename _ExtractKey, 1251 typename _H1, typename _H2> 1252 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, 1253 _Default_ranged_hash, false> 1254 : private _Hashtable_ebo_helper<0, _ExtractKey>, 1255 private _Hashtable_ebo_helper<1, _H1>, 1256 private _Hashtable_ebo_helper<2, _H2> 1257 { 1258 private: 1259 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>; 1260 using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>; 1261 using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>; 1262 1263 // Gives the local iterator implementation access to _M_bucket_index(). 1264 friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, 1265 _Default_ranged_hash, false>; 1266 1267 public: 1268 typedef _H1 hasher; 1269 1270 hasher 1271 hash_function() const 1272 { return _M_h1(); } 1273 1274 protected: 1275 typedef std::size_t __hash_code; 1276 typedef _Hash_node<_Value, false> __node_type; 1277 1278 // We need the default constructor for the local iterators and _Hashtable 1279 // default constructor. 1280 _Hash_code_base() = default; 1281 1282 _Hash_code_base(const _ExtractKey& __ex, 1283 const _H1& __h1, const _H2& __h2, 1284 const _Default_ranged_hash&) 1285 : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { } 1286 1287 __hash_code 1288 _M_hash_code(const _Key& __k) const 1289 { 1290 static_assert(__is_invocable<const _H1&, const _Key&>{}, 1291 "hash function must be invocable with an argument of key type"); 1292 return _M_h1()(__k); 1293 } 1294 1295 std::size_t 1296 _M_bucket_index(const _Key&, __hash_code __c, std::size_t __n) const 1297 { return _M_h2()(__c, __n); } 1298 1299 std::size_t 1300 _M_bucket_index(const __node_type* __p, std::size_t __n) const 1301 noexcept( noexcept(declval<const _H1&>()(declval<const _Key&>())) 1302 && noexcept(declval<const _H2&>()((__hash_code)0, 1303 (std::size_t)0)) ) 1304 { return _M_h2()(_M_h1()(_M_extract()(__p->_M_v())), __n); } 1305 1306 void 1307 _M_store_code(__node_type*, __hash_code) const 1308 { } 1309 1310 void 1311 _M_copy_code(__node_type*, const __node_type*) const 1312 { } 1313 1314 void 1315 _M_swap(_Hash_code_base& __x) 1316 { 1317 std::swap(_M_extract(), __x._M_extract()); 1318 std::swap(_M_h1(), __x._M_h1()); 1319 std::swap(_M_h2(), __x._M_h2()); 1320 } 1321 1322 const _ExtractKey& 1323 _M_extract() const { return __ebo_extract_key::_S_cget(*this); } 1324 1325 _ExtractKey& 1326 _M_extract() { return __ebo_extract_key::_S_get(*this); } 1327 1328 const _H1& 1329 _M_h1() const { return __ebo_h1::_S_cget(*this); } 1330 1331 _H1& 1332 _M_h1() { return __ebo_h1::_S_get(*this); } 1333 1334 const _H2& 1335 _M_h2() const { return __ebo_h2::_S_cget(*this); } 1336 1337 _H2& 1338 _M_h2() { return __ebo_h2::_S_get(*this); } 1339 }; 1340 1341 /// Specialization: hash function and range-hashing function, 1342 /// caching hash codes. H is provided but ignored. Provides 1343 /// typedef and accessor required by C++ 11. 1344 template<typename _Key, typename _Value, typename _ExtractKey, 1345 typename _H1, typename _H2> 1346 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, 1347 _Default_ranged_hash, true> 1348 : private _Hashtable_ebo_helper<0, _ExtractKey>, 1349 private _Hashtable_ebo_helper<1, _H1>, 1350 private _Hashtable_ebo_helper<2, _H2> 1351 { 1352 private: 1353 // Gives the local iterator implementation access to _M_h2(). 1354 friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, 1355 _Default_ranged_hash, true>; 1356 1357 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>; 1358 using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>; 1359 using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>; 1360 1361 public: 1362 typedef _H1 hasher; 1363 1364 hasher 1365 hash_function() const 1366 { return _M_h1(); } 1367 1368 protected: 1369 typedef std::size_t __hash_code; 1370 typedef _Hash_node<_Value, true> __node_type; 1371 1372 // We need the default constructor for _Hashtable default constructor. 1373 _Hash_code_base() = default; 1374 _Hash_code_base(const _ExtractKey& __ex, 1375 const _H1& __h1, const _H2& __h2, 1376 const _Default_ranged_hash&) 1377 : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { } 1378 1379 __hash_code 1380 _M_hash_code(const _Key& __k) const 1381 { 1382 static_assert(__is_invocable<const _H1&, const _Key&>{}, 1383 "hash function must be invocable with an argument of key type"); 1384 return _M_h1()(__k); 1385 } 1386 1387 std::size_t 1388 _M_bucket_index(const _Key&, __hash_code __c, 1389 std::size_t __n) const 1390 { return _M_h2()(__c, __n); } 1391 1392 std::size_t 1393 _M_bucket_index(const __node_type* __p, std::size_t __n) const 1394 noexcept( noexcept(declval<const _H2&>()((__hash_code)0, 1395 (std::size_t)0)) ) 1396 { return _M_h2()(__p->_M_hash_code, __n); } 1397 1398 void 1399 _M_store_code(__node_type* __n, __hash_code __c) const 1400 { __n->_M_hash_code = __c; } 1401 1402 void 1403 _M_copy_code(__node_type* __to, const __node_type* __from) const 1404 { __to->_M_hash_code = __from->_M_hash_code; } 1405 1406 void 1407 _M_swap(_Hash_code_base& __x) 1408 { 1409 std::swap(_M_extract(), __x._M_extract()); 1410 std::swap(_M_h1(), __x._M_h1()); 1411 std::swap(_M_h2(), __x._M_h2()); 1412 } 1413 1414 const _ExtractKey& 1415 _M_extract() const { return __ebo_extract_key::_S_cget(*this); } 1416 1417 _ExtractKey& 1418 _M_extract() { return __ebo_extract_key::_S_get(*this); } 1419 1420 const _H1& 1421 _M_h1() const { return __ebo_h1::_S_cget(*this); } 1422 1423 _H1& 1424 _M_h1() { return __ebo_h1::_S_get(*this); } 1425 1426 const _H2& 1427 _M_h2() const { return __ebo_h2::_S_cget(*this); } 1428 1429 _H2& 1430 _M_h2() { return __ebo_h2::_S_get(*this); } 1431 }; 1432 1433 /** 1434 * Primary class template _Equal_helper. 1435 * 1436 */ 1437 template <typename _Key, typename _Value, typename _ExtractKey, 1438 typename _Equal, typename _HashCodeType, 1439 bool __cache_hash_code> 1440 struct _Equal_helper; 1441 1442 /// Specialization. 1443 template<typename _Key, typename _Value, typename _ExtractKey, 1444 typename _Equal, typename _HashCodeType> 1445 struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, true> 1446 { 1447 static bool 1448 _S_equals(const _Equal& __eq, const _ExtractKey& __extract, 1449 const _Key& __k, _HashCodeType __c, _Hash_node<_Value, true>* __n) 1450 { return __c == __n->_M_hash_code && __eq(__k, __extract(__n->_M_v())); } 1451 }; 1452 1453 /// Specialization. 1454 template<typename _Key, typename _Value, typename _ExtractKey, 1455 typename _Equal, typename _HashCodeType> 1456 struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, false> 1457 { 1458 static bool 1459 _S_equals(const _Equal& __eq, const _ExtractKey& __extract, 1460 const _Key& __k, _HashCodeType, _Hash_node<_Value, false>* __n) 1461 { return __eq(__k, __extract(__n->_M_v())); } 1462 }; 1463 1464 1465 /// Partial specialization used when nodes contain a cached hash code. 1466 template<typename _Key, typename _Value, typename _ExtractKey, 1467 typename _H1, typename _H2, typename _Hash> 1468 struct _Local_iterator_base<_Key, _Value, _ExtractKey, 1469 _H1, _H2, _Hash, true> 1470 : private _Hashtable_ebo_helper<0, _H2> 1471 { 1472 protected: 1473 using __base_type = _Hashtable_ebo_helper<0, _H2>; 1474 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, 1475 _H1, _H2, _Hash, true>; 1476 1477 _Local_iterator_base() = default; 1478 _Local_iterator_base(const __hash_code_base& __base, 1479 _Hash_node<_Value, true>* __p, 1480 std::size_t __bkt, std::size_t __bkt_count) 1481 : __base_type(__base._M_h2()), 1482 _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { } 1483 1484 void 1485 _M_incr() 1486 { 1487 _M_cur = _M_cur->_M_next(); 1488 if (_M_cur) 1489 { 1490 std::size_t __bkt 1491 = __base_type::_S_get(*this)(_M_cur->_M_hash_code, 1492 _M_bucket_count); 1493 if (__bkt != _M_bucket) 1494 _M_cur = nullptr; 1495 } 1496 } 1497 1498 _Hash_node<_Value, true>* _M_cur; 1499 std::size_t _M_bucket; 1500 std::size_t _M_bucket_count; 1501 1502 public: 1503 const void* 1504 _M_curr() const { return _M_cur; } // for equality ops 1505 1506 std::size_t 1507 _M_get_bucket() const { return _M_bucket; } // for debug mode 1508 }; 1509 1510 // Uninitialized storage for a _Hash_code_base. 1511 // This type is DefaultConstructible and Assignable even if the 1512 // _Hash_code_base type isn't, so that _Local_iterator_base<..., false> 1513 // can be DefaultConstructible and Assignable. 1514 template<typename _Tp, bool _IsEmpty = std::is_empty<_Tp>::value> 1515 struct _Hash_code_storage 1516 { 1517 __gnu_cxx::__aligned_buffer<_Tp> _M_storage; 1518 1519 _Tp* 1520 _M_h() { return _M_storage._M_ptr(); } 1521 1522 const _Tp* 1523 _M_h() const { return _M_storage._M_ptr(); } 1524 }; 1525 1526 // Empty partial specialization for empty _Hash_code_base types. 1527 template<typename _Tp> 1528 struct _Hash_code_storage<_Tp, true> 1529 { 1530 static_assert( std::is_empty<_Tp>::value, "Type must be empty" ); 1531 1532 // As _Tp is an empty type there will be no bytes written/read through 1533 // the cast pointer, so no strict-aliasing violation. 1534 _Tp* 1535 _M_h() { return reinterpret_cast<_Tp*>(this); } 1536 1537 const _Tp* 1538 _M_h() const { return reinterpret_cast<const _Tp*>(this); } 1539 }; 1540 1541 template<typename _Key, typename _Value, typename _ExtractKey, 1542 typename _H1, typename _H2, typename _Hash> 1543 using __hash_code_for_local_iter 1544 = _Hash_code_storage<_Hash_code_base<_Key, _Value, _ExtractKey, 1545 _H1, _H2, _Hash, false>>; 1546 1547 // Partial specialization used when hash codes are not cached 1548 template<typename _Key, typename _Value, typename _ExtractKey, 1549 typename _H1, typename _H2, typename _Hash> 1550 struct _Local_iterator_base<_Key, _Value, _ExtractKey, 1551 _H1, _H2, _Hash, false> 1552 : __hash_code_for_local_iter<_Key, _Value, _ExtractKey, _H1, _H2, _Hash> 1553 { 1554 protected: 1555 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, 1556 _H1, _H2, _Hash, false>; 1557 1558 _Local_iterator_base() : _M_bucket_count(-1) { } 1559 1560 _Local_iterator_base(const __hash_code_base& __base, 1561 _Hash_node<_Value, false>* __p, 1562 std::size_t __bkt, std::size_t __bkt_count) 1563 : _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) 1564 { _M_init(__base); } 1565 1566 ~_Local_iterator_base() 1567 { 1568 if (_M_bucket_count != -1) 1569 _M_destroy(); 1570 } 1571 1572 _Local_iterator_base(const _Local_iterator_base& __iter) 1573 : _M_cur(__iter._M_cur), _M_bucket(__iter._M_bucket), 1574 _M_bucket_count(__iter._M_bucket_count) 1575 { 1576 if (_M_bucket_count != -1) 1577 _M_init(*__iter._M_h()); 1578 } 1579 1580 _Local_iterator_base& 1581 operator=(const _Local_iterator_base& __iter) 1582 { 1583 if (_M_bucket_count != -1) 1584 _M_destroy(); 1585 _M_cur = __iter._M_cur; 1586 _M_bucket = __iter._M_bucket; 1587 _M_bucket_count = __iter._M_bucket_count; 1588 if (_M_bucket_count != -1) 1589 _M_init(*__iter._M_h()); 1590 return *this; 1591 } 1592 1593 void 1594 _M_incr() 1595 { 1596 _M_cur = _M_cur->_M_next(); 1597 if (_M_cur) 1598 { 1599 std::size_t __bkt = this->_M_h()->_M_bucket_index(_M_cur, 1600 _M_bucket_count); 1601 if (__bkt != _M_bucket) 1602 _M_cur = nullptr; 1603 } 1604 } 1605 1606 _Hash_node<_Value, false>* _M_cur; 1607 std::size_t _M_bucket; 1608 std::size_t _M_bucket_count; 1609 1610 void 1611 _M_init(const __hash_code_base& __base) 1612 { ::new(this->_M_h()) __hash_code_base(__base); } 1613 1614 void 1615 _M_destroy() { this->_M_h()->~__hash_code_base(); } 1616 1617 public: 1618 const void* 1619 _M_curr() const { return _M_cur; } // for equality ops and debug mode 1620 1621 std::size_t 1622 _M_get_bucket() const { return _M_bucket; } // for debug mode 1623 }; 1624 1625 template<typename _Key, typename _Value, typename _ExtractKey, 1626 typename _H1, typename _H2, typename _Hash, bool __cache> 1627 inline bool 1628 operator==(const _Local_iterator_base<_Key, _Value, _ExtractKey, 1629 _H1, _H2, _Hash, __cache>& __x, 1630 const _Local_iterator_base<_Key, _Value, _ExtractKey, 1631 _H1, _H2, _Hash, __cache>& __y) 1632 { return __x._M_curr() == __y._M_curr(); } 1633 1634 template<typename _Key, typename _Value, typename _ExtractKey, 1635 typename _H1, typename _H2, typename _Hash, bool __cache> 1636 inline bool 1637 operator!=(const _Local_iterator_base<_Key, _Value, _ExtractKey, 1638 _H1, _H2, _Hash, __cache>& __x, 1639 const _Local_iterator_base<_Key, _Value, _ExtractKey, 1640 _H1, _H2, _Hash, __cache>& __y) 1641 { return __x._M_curr() != __y._M_curr(); } 1642 1643 /// local iterators 1644 template<typename _Key, typename _Value, typename _ExtractKey, 1645 typename _H1, typename _H2, typename _Hash, 1646 bool __constant_iterators, bool __cache> 1647 struct _Local_iterator 1648 : public _Local_iterator_base<_Key, _Value, _ExtractKey, 1649 _H1, _H2, _Hash, __cache> 1650 { 1651 private: 1652 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey, 1653 _H1, _H2, _Hash, __cache>; 1654 using __hash_code_base = typename __base_type::__hash_code_base; 1655 public: 1656 typedef _Value value_type; 1657 typedef typename std::conditional<__constant_iterators, 1658 const _Value*, _Value*>::type 1659 pointer; 1660 typedef typename std::conditional<__constant_iterators, 1661 const _Value&, _Value&>::type 1662 reference; 1663 typedef std::ptrdiff_t difference_type; 1664 typedef std::forward_iterator_tag iterator_category; 1665 1666 _Local_iterator() = default; 1667 1668 _Local_iterator(const __hash_code_base& __base, 1669 _Hash_node<_Value, __cache>* __p, 1670 std::size_t __bkt, std::size_t __bkt_count) 1671 : __base_type(__base, __p, __bkt, __bkt_count) 1672 { } 1673 1674 reference 1675 operator*() const 1676 { return this->_M_cur->_M_v(); } 1677 1678 pointer 1679 operator->() const 1680 { return this->_M_cur->_M_valptr(); } 1681 1682 _Local_iterator& 1683 operator++() 1684 { 1685 this->_M_incr(); 1686 return *this; 1687 } 1688 1689 _Local_iterator 1690 operator++(int) 1691 { 1692 _Local_iterator __tmp(*this); 1693 this->_M_incr(); 1694 return __tmp; 1695 } 1696 }; 1697 1698 /// local const_iterators 1699 template<typename _Key, typename _Value, typename _ExtractKey, 1700 typename _H1, typename _H2, typename _Hash, 1701 bool __constant_iterators, bool __cache> 1702 struct _Local_const_iterator 1703 : public _Local_iterator_base<_Key, _Value, _ExtractKey, 1704 _H1, _H2, _Hash, __cache> 1705 { 1706 private: 1707 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey, 1708 _H1, _H2, _Hash, __cache>; 1709 using __hash_code_base = typename __base_type::__hash_code_base; 1710 1711 public: 1712 typedef _Value value_type; 1713 typedef const _Value* pointer; 1714 typedef const _Value& reference; 1715 typedef std::ptrdiff_t difference_type; 1716 typedef std::forward_iterator_tag iterator_category; 1717 1718 _Local_const_iterator() = default; 1719 1720 _Local_const_iterator(const __hash_code_base& __base, 1721 _Hash_node<_Value, __cache>* __p, 1722 std::size_t __bkt, std::size_t __bkt_count) 1723 : __base_type(__base, __p, __bkt, __bkt_count) 1724 { } 1725 1726 _Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey, 1727 _H1, _H2, _Hash, 1728 __constant_iterators, 1729 __cache>& __x) 1730 : __base_type(__x) 1731 { } 1732 1733 reference 1734 operator*() const 1735 { return this->_M_cur->_M_v(); } 1736 1737 pointer 1738 operator->() const 1739 { return this->_M_cur->_M_valptr(); } 1740 1741 _Local_const_iterator& 1742 operator++() 1743 { 1744 this->_M_incr(); 1745 return *this; 1746 } 1747 1748 _Local_const_iterator 1749 operator++(int) 1750 { 1751 _Local_const_iterator __tmp(*this); 1752 this->_M_incr(); 1753 return __tmp; 1754 } 1755 }; 1756 1757 /** 1758 * Primary class template _Hashtable_base. 1759 * 1760 * Helper class adding management of _Equal functor to 1761 * _Hash_code_base type. 1762 * 1763 * Base class templates are: 1764 * - __detail::_Hash_code_base 1765 * - __detail::_Hashtable_ebo_helper 1766 */ 1767 template<typename _Key, typename _Value, 1768 typename _ExtractKey, typename _Equal, 1769 typename _H1, typename _H2, typename _Hash, typename _Traits> 1770 struct _Hashtable_base 1771 : public _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, 1772 _Traits::__hash_cached::value>, 1773 private _Hashtable_ebo_helper<0, _Equal> 1774 { 1775 public: 1776 typedef _Key key_type; 1777 typedef _Value value_type; 1778 typedef _Equal key_equal; 1779 typedef std::size_t size_type; 1780 typedef std::ptrdiff_t difference_type; 1781 1782 using __traits_type = _Traits; 1783 using __hash_cached = typename __traits_type::__hash_cached; 1784 using __constant_iterators = typename __traits_type::__constant_iterators; 1785 using __unique_keys = typename __traits_type::__unique_keys; 1786 1787 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, 1788 _H1, _H2, _Hash, 1789 __hash_cached::value>; 1790 1791 using __hash_code = typename __hash_code_base::__hash_code; 1792 using __node_type = typename __hash_code_base::__node_type; 1793 1794 using iterator = __detail::_Node_iterator<value_type, 1795 __constant_iterators::value, 1796 __hash_cached::value>; 1797 1798 using const_iterator = __detail::_Node_const_iterator<value_type, 1799 __constant_iterators::value, 1800 __hash_cached::value>; 1801 1802 using local_iterator = __detail::_Local_iterator<key_type, value_type, 1803 _ExtractKey, _H1, _H2, _Hash, 1804 __constant_iterators::value, 1805 __hash_cached::value>; 1806 1807 using const_local_iterator = __detail::_Local_const_iterator<key_type, 1808 value_type, 1809 _ExtractKey, _H1, _H2, _Hash, 1810 __constant_iterators::value, 1811 __hash_cached::value>; 1812 1813 using __ireturn_type = typename std::conditional<__unique_keys::value, 1814 std::pair<iterator, bool>, 1815 iterator>::type; 1816 private: 1817 using _EqualEBO = _Hashtable_ebo_helper<0, _Equal>; 1818 using _EqualHelper = _Equal_helper<_Key, _Value, _ExtractKey, _Equal, 1819 __hash_code, __hash_cached::value>; 1820 1821 protected: 1822 _Hashtable_base() = default; 1823 _Hashtable_base(const _ExtractKey& __ex, const _H1& __h1, const _H2& __h2, 1824 const _Hash& __hash, const _Equal& __eq) 1825 : __hash_code_base(__ex, __h1, __h2, __hash), _EqualEBO(__eq) 1826 { } 1827 1828 bool 1829 _M_equals(const _Key& __k, __hash_code __c, __node_type* __n) const 1830 { 1831 static_assert(__is_invocable<const _Equal&, const _Key&, const _Key&>{}, 1832 "key equality predicate must be invocable with two arguments of " 1833 "key type"); 1834 return _EqualHelper::_S_equals(_M_eq(), this->_M_extract(), 1835 __k, __c, __n); 1836 } 1837 1838 void 1839 _M_swap(_Hashtable_base& __x) 1840 { 1841 __hash_code_base::_M_swap(__x); 1842 std::swap(_M_eq(), __x._M_eq()); 1843 } 1844 1845 const _Equal& 1846 _M_eq() const { return _EqualEBO::_S_cget(*this); } 1847 1848 _Equal& 1849 _M_eq() { return _EqualEBO::_S_get(*this); } 1850 }; 1851 1852 /** 1853 * struct _Equality_base. 1854 * 1855 * Common types and functions for class _Equality. 1856 */ 1857 struct _Equality_base 1858 { 1859 protected: 1860 template<typename _Uiterator> 1861 static bool 1862 _S_is_permutation(_Uiterator, _Uiterator, _Uiterator); 1863 }; 1864 1865 // See std::is_permutation in N3068. 1866 template<typename _Uiterator> 1867 bool 1868 _Equality_base:: 1869 _S_is_permutation(_Uiterator __first1, _Uiterator __last1, 1870 _Uiterator __first2) 1871 { 1872 for (; __first1 != __last1; ++__first1, ++__first2) 1873 if (!(*__first1 == *__first2)) 1874 break; 1875 1876 if (__first1 == __last1) 1877 return true; 1878 1879 _Uiterator __last2 = __first2; 1880 std::advance(__last2, std::distance(__first1, __last1)); 1881 1882 for (_Uiterator __it1 = __first1; __it1 != __last1; ++__it1) 1883 { 1884 _Uiterator __tmp = __first1; 1885 while (__tmp != __it1 && !bool(*__tmp == *__it1)) 1886 ++__tmp; 1887 1888 // We've seen this one before. 1889 if (__tmp != __it1) 1890 continue; 1891 1892 std::ptrdiff_t __n2 = 0; 1893 for (__tmp = __first2; __tmp != __last2; ++__tmp) 1894 if (*__tmp == *__it1) 1895 ++__n2; 1896 1897 if (!__n2) 1898 return false; 1899 1900 std::ptrdiff_t __n1 = 0; 1901 for (__tmp = __it1; __tmp != __last1; ++__tmp) 1902 if (*__tmp == *__it1) 1903 ++__n1; 1904 1905 if (__n1 != __n2) 1906 return false; 1907 } 1908 return true; 1909 } 1910 1911 /** 1912 * Primary class template _Equality. 1913 * 1914 * This is for implementing equality comparison for unordered 1915 * containers, per N3068, by John Lakos and Pablo Halpern. 1916 * Algorithmically, we follow closely the reference implementations 1917 * therein. 1918 */ 1919 template<typename _Key, typename _Value, typename _Alloc, 1920 typename _ExtractKey, typename _Equal, 1921 typename _H1, typename _H2, typename _Hash, 1922 typename _RehashPolicy, typename _Traits, 1923 bool _Unique_keys = _Traits::__unique_keys::value> 1924 struct _Equality; 1925 1926 /// Specialization. 1927 template<typename _Key, typename _Value, typename _Alloc, 1928 typename _ExtractKey, typename _Equal, 1929 typename _H1, typename _H2, typename _Hash, 1930 typename _RehashPolicy, typename _Traits> 1931 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1932 _H1, _H2, _Hash, _RehashPolicy, _Traits, true> 1933 { 1934 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1935 _H1, _H2, _Hash, _RehashPolicy, _Traits>; 1936 1937 bool 1938 _M_equal(const __hashtable&) const; 1939 }; 1940 1941 template<typename _Key, typename _Value, typename _Alloc, 1942 typename _ExtractKey, typename _Equal, 1943 typename _H1, typename _H2, typename _Hash, 1944 typename _RehashPolicy, typename _Traits> 1945 bool 1946 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1947 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 1948 _M_equal(const __hashtable& __other) const 1949 { 1950 const __hashtable* __this = static_cast<const __hashtable*>(this); 1951 1952 if (__this->size() != __other.size()) 1953 return false; 1954 1955 for (auto __itx = __this->begin(); __itx != __this->end(); ++__itx) 1956 { 1957 const auto __ity = __other.find(_ExtractKey()(*__itx)); 1958 if (__ity == __other.end() || !bool(*__ity == *__itx)) 1959 return false; 1960 } 1961 return true; 1962 } 1963 1964 /// Specialization. 1965 template<typename _Key, typename _Value, typename _Alloc, 1966 typename _ExtractKey, typename _Equal, 1967 typename _H1, typename _H2, typename _Hash, 1968 typename _RehashPolicy, typename _Traits> 1969 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1970 _H1, _H2, _Hash, _RehashPolicy, _Traits, false> 1971 : public _Equality_base 1972 { 1973 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1974 _H1, _H2, _Hash, _RehashPolicy, _Traits>; 1975 1976 bool 1977 _M_equal(const __hashtable&) const; 1978 }; 1979 1980 template<typename _Key, typename _Value, typename _Alloc, 1981 typename _ExtractKey, typename _Equal, 1982 typename _H1, typename _H2, typename _Hash, 1983 typename _RehashPolicy, typename _Traits> 1984 bool 1985 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1986 _H1, _H2, _Hash, _RehashPolicy, _Traits, false>:: 1987 _M_equal(const __hashtable& __other) const 1988 { 1989 const __hashtable* __this = static_cast<const __hashtable*>(this); 1990 1991 if (__this->size() != __other.size()) 1992 return false; 1993 1994 for (auto __itx = __this->begin(); __itx != __this->end();) 1995 { 1996 const auto __xrange = __this->equal_range(_ExtractKey()(*__itx)); 1997 const auto __yrange = __other.equal_range(_ExtractKey()(*__itx)); 1998 1999 if (std::distance(__xrange.first, __xrange.second) 2000 != std::distance(__yrange.first, __yrange.second)) 2001 return false; 2002 2003 if (!_S_is_permutation(__xrange.first, __xrange.second, 2004 __yrange.first)) 2005 return false; 2006 2007 __itx = __xrange.second; 2008 } 2009 return true; 2010 } 2011 2012 /** 2013 * This type deals with all allocation and keeps an allocator instance through 2014 * inheritance to benefit from EBO when possible. 2015 */ 2016 template<typename _NodeAlloc> 2017 struct _Hashtable_alloc : private _Hashtable_ebo_helper<0, _NodeAlloc> 2018 { 2019 private: 2020 using __ebo_node_alloc = _Hashtable_ebo_helper<0, _NodeAlloc>; 2021 public: 2022 using __node_type = typename _NodeAlloc::value_type; 2023 using __node_alloc_type = _NodeAlloc; 2024 // Use __gnu_cxx to benefit from _S_always_equal and al. 2025 using __node_alloc_traits = __gnu_cxx::__alloc_traits<__node_alloc_type>; 2026 2027 using __value_alloc_traits = typename __node_alloc_traits::template 2028 rebind_traits<typename __node_type::value_type>; 2029 2030 using __node_base = __detail::_Hash_node_base; 2031 using __bucket_type = __node_base*; 2032 using __bucket_alloc_type = 2033 __alloc_rebind<__node_alloc_type, __bucket_type>; 2034 using __bucket_alloc_traits = std::allocator_traits<__bucket_alloc_type>; 2035 2036 _Hashtable_alloc() = default; 2037 _Hashtable_alloc(const _Hashtable_alloc&) = default; 2038 _Hashtable_alloc(_Hashtable_alloc&&) = default; 2039 2040 template<typename _Alloc> 2041 _Hashtable_alloc(_Alloc&& __a) 2042 : __ebo_node_alloc(std::forward<_Alloc>(__a)) 2043 { } 2044 2045 __node_alloc_type& 2046 _M_node_allocator() 2047 { return __ebo_node_alloc::_S_get(*this); } 2048 2049 const __node_alloc_type& 2050 _M_node_allocator() const 2051 { return __ebo_node_alloc::_S_cget(*this); } 2052 2053 template<typename... _Args> 2054 __node_type* 2055 _M_allocate_node(_Args&&... __args); 2056 2057 void 2058 _M_deallocate_node(__node_type* __n); 2059 2060 void 2061 _M_deallocate_node_ptr(__node_type* __n); 2062 2063 // Deallocate the linked list of nodes pointed to by __n 2064 void 2065 _M_deallocate_nodes(__node_type* __n); 2066 2067 __bucket_type* 2068 _M_allocate_buckets(std::size_t __n); 2069 2070 void 2071 _M_deallocate_buckets(__bucket_type*, std::size_t __n); 2072 }; 2073 2074 // Definitions of class template _Hashtable_alloc's out-of-line member 2075 // functions. 2076 template<typename _NodeAlloc> 2077 template<typename... _Args> 2078 typename _Hashtable_alloc<_NodeAlloc>::__node_type* 2079 _Hashtable_alloc<_NodeAlloc>::_M_allocate_node(_Args&&... __args) 2080 { 2081 auto __nptr = __node_alloc_traits::allocate(_M_node_allocator(), 1); 2082 __node_type* __n = std::__to_address(__nptr); 2083 __try 2084 { 2085 ::new ((void*)__n) __node_type; 2086 __node_alloc_traits::construct(_M_node_allocator(), 2087 __n->_M_valptr(), 2088 std::forward<_Args>(__args)...); 2089 return __n; 2090 } 2091 __catch(...) 2092 { 2093 __node_alloc_traits::deallocate(_M_node_allocator(), __nptr, 1); 2094 __throw_exception_again; 2095 } 2096 } 2097 2098 template<typename _NodeAlloc> 2099 void 2100 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node(__node_type* __n) 2101 { 2102 __node_alloc_traits::destroy(_M_node_allocator(), __n->_M_valptr()); 2103 _M_deallocate_node_ptr(__n); 2104 } 2105 2106 template<typename _NodeAlloc> 2107 void 2108 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node_ptr(__node_type* __n) 2109 { 2110 typedef typename __node_alloc_traits::pointer _Ptr; 2111 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__n); 2112 __n->~__node_type(); 2113 __node_alloc_traits::deallocate(_M_node_allocator(), __ptr, 1); 2114 } 2115 2116 template<typename _NodeAlloc> 2117 void 2118 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_nodes(__node_type* __n) 2119 { 2120 while (__n) 2121 { 2122 __node_type* __tmp = __n; 2123 __n = __n->_M_next(); 2124 _M_deallocate_node(__tmp); 2125 } 2126 } 2127 2128 template<typename _NodeAlloc> 2129 typename _Hashtable_alloc<_NodeAlloc>::__bucket_type* 2130 _Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets(std::size_t __n) 2131 { 2132 __bucket_alloc_type __alloc(_M_node_allocator()); 2133 2134 auto __ptr = __bucket_alloc_traits::allocate(__alloc, __n); 2135 __bucket_type* __p = std::__to_address(__ptr); 2136 __builtin_memset(__p, 0, __n * sizeof(__bucket_type)); 2137 return __p; 2138 } 2139 2140 template<typename _NodeAlloc> 2141 void 2142 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_buckets(__bucket_type* __bkts, 2143 std::size_t __n) 2144 { 2145 typedef typename __bucket_alloc_traits::pointer _Ptr; 2146 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__bkts); 2147 __bucket_alloc_type __alloc(_M_node_allocator()); 2148 __bucket_alloc_traits::deallocate(__alloc, __ptr, __n); 2149 } 2150 2151 //@} hashtable-detail 2152 } // namespace __detail 2153 _GLIBCXX_END_NAMESPACE_VERSION 2154 } // namespace std 2155 2156 #endif // _HASHTABLE_POLICY_H 2157