1 // Internal policy header for unordered_set and unordered_map -*- C++ -*- 2 3 // Copyright (C) 2010-2020 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, std::is_permutation. 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 _Hash or _Equal 185 * functors. 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 = 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_ceill(__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::bit_ceil(__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 = 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 if (__n == 0) 539 // Special case on container 1st initialization with 0 bucket count 540 // hint. We keep _M_next_resize to 0 to make sure that next time we 541 // want to add an element allocation will take place. 542 return 1; 543 544 const auto __max_width = std::min<size_t>(sizeof(size_t), 8); 545 const auto __max_bkt = size_t(1) << (__max_width * __CHAR_BIT__ - 1); 546 std::size_t __res = __clp2(__n); 547 548 if (__res == 0) 549 __res = __max_bkt; 550 else if (__res == 1) 551 // If __res is 1 we force it to 2 to make sure there will be an 552 // allocation so that nothing need to be stored in the initial 553 // single bucket 554 __res = 2; 555 556 if (__res == __max_bkt) 557 // Set next resize to the max value so that we never try to rehash again 558 // as we already reach the biggest possible bucket number. 559 // Note that it might result in max_load_factor not being respected. 560 _M_next_resize = numeric_limits<size_t>::max(); 561 else 562 _M_next_resize 563 = __builtin_floorl(__res * (long double)_M_max_load_factor); 564 565 return __res; 566 } 567 568 // Return a bucket count appropriate for n elements 569 std::size_t 570 _M_bkt_for_elements(std::size_t __n) const noexcept 571 { return __builtin_ceill(__n / (long double)_M_max_load_factor); } 572 573 // __n_bkt is current bucket count, __n_elt is current element count, 574 // and __n_ins is number of elements to be inserted. Do we need to 575 // increase bucket count? If so, return make_pair(true, n), where n 576 // is the new bucket count. If not, return make_pair(false, 0). 577 std::pair<bool, std::size_t> 578 _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, 579 std::size_t __n_ins) noexcept 580 { 581 if (__n_elt + __n_ins > _M_next_resize) 582 { 583 // If _M_next_resize is 0 it means that we have nothing allocated so 584 // far and that we start inserting elements. In this case we start 585 // with an initial bucket size of 11. 586 long double __min_bkts 587 = std::max<std::size_t>(__n_elt + __n_ins, _M_next_resize ? 0 : 11) 588 / (long double)_M_max_load_factor; 589 if (__min_bkts >= __n_bkt) 590 return { true, 591 _M_next_bkt(std::max<std::size_t>(__builtin_floorl(__min_bkts) + 1, 592 __n_bkt * _S_growth_factor)) }; 593 594 _M_next_resize 595 = __builtin_floorl(__n_bkt * (long double)_M_max_load_factor); 596 return { false, 0 }; 597 } 598 else 599 return { false, 0 }; 600 } 601 602 typedef std::size_t _State; 603 604 _State 605 _M_state() const noexcept 606 { return _M_next_resize; } 607 608 void 609 _M_reset() noexcept 610 { _M_next_resize = 0; } 611 612 void 613 _M_reset(_State __state) noexcept 614 { _M_next_resize = __state; } 615 616 static const std::size_t _S_growth_factor = 2; 617 618 float _M_max_load_factor; 619 std::size_t _M_next_resize; 620 }; 621 622 // Base classes for std::_Hashtable. We define these base classes 623 // because in some cases we want to do different things depending on 624 // the value of a policy class. In some cases the policy class 625 // affects which member functions and nested typedefs are defined; 626 // we handle that by specializing base class templates. Several of 627 // the base class templates need to access other members of class 628 // template _Hashtable, so we use a variant of the "Curiously 629 // Recurring Template Pattern" (CRTP) technique. 630 631 /** 632 * Primary class template _Map_base. 633 * 634 * If the hashtable has a value type of the form pair<T1, T2> and a 635 * key extraction policy (_ExtractKey) that returns the first part 636 * of the pair, the hashtable gets a mapped_type typedef. If it 637 * satisfies those criteria and also has unique keys, then it also 638 * gets an operator[]. 639 */ 640 template<typename _Key, typename _Value, typename _Alloc, 641 typename _ExtractKey, typename _Equal, 642 typename _H1, typename _H2, typename _Hash, 643 typename _RehashPolicy, typename _Traits, 644 bool _Unique_keys = _Traits::__unique_keys::value> 645 struct _Map_base { }; 646 647 /// Partial specialization, __unique_keys set to false. 648 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 649 typename _H1, typename _H2, typename _Hash, 650 typename _RehashPolicy, typename _Traits> 651 struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 652 _H1, _H2, _Hash, _RehashPolicy, _Traits, false> 653 { 654 using mapped_type = typename std::tuple_element<1, _Pair>::type; 655 }; 656 657 /// Partial specialization, __unique_keys set to true. 658 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 659 typename _H1, typename _H2, typename _Hash, 660 typename _RehashPolicy, typename _Traits> 661 struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 662 _H1, _H2, _Hash, _RehashPolicy, _Traits, true> 663 { 664 private: 665 using __hashtable_base = __detail::_Hashtable_base<_Key, _Pair, 666 _Select1st, 667 _Equal, _H1, _H2, _Hash, 668 _Traits>; 669 670 using __hashtable = _Hashtable<_Key, _Pair, _Alloc, 671 _Select1st, _Equal, 672 _H1, _H2, _Hash, _RehashPolicy, _Traits>; 673 674 using __hash_code = typename __hashtable_base::__hash_code; 675 using __node_type = typename __hashtable_base::__node_type; 676 677 public: 678 using key_type = typename __hashtable_base::key_type; 679 using iterator = typename __hashtable_base::iterator; 680 using mapped_type = typename std::tuple_element<1, _Pair>::type; 681 682 mapped_type& 683 operator[](const key_type& __k); 684 685 mapped_type& 686 operator[](key_type&& __k); 687 688 // _GLIBCXX_RESOLVE_LIB_DEFECTS 689 // DR 761. unordered_map needs an at() member function. 690 mapped_type& 691 at(const key_type& __k); 692 693 const mapped_type& 694 at(const key_type& __k) const; 695 }; 696 697 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 698 typename _H1, typename _H2, typename _Hash, 699 typename _RehashPolicy, typename _Traits> 700 auto 701 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 702 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 703 operator[](const key_type& __k) 704 -> mapped_type& 705 { 706 __hashtable* __h = static_cast<__hashtable*>(this); 707 __hash_code __code = __h->_M_hash_code(__k); 708 std::size_t __bkt = __h->_M_bucket_index(__k, __code); 709 if (__node_type* __node = __h->_M_find_node(__bkt, __k, __code)) 710 return __node->_M_v().second; 711 712 typename __hashtable::_Scoped_node __node { 713 __h, 714 std::piecewise_construct, 715 std::tuple<const key_type&>(__k), 716 std::tuple<>() 717 }; 718 auto __pos 719 = __h->_M_insert_unique_node(__k, __bkt, __code, __node._M_node); 720 __node._M_node = nullptr; 721 return __pos->second; 722 } 723 724 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 725 typename _H1, typename _H2, typename _Hash, 726 typename _RehashPolicy, typename _Traits> 727 auto 728 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 729 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 730 operator[](key_type&& __k) 731 -> mapped_type& 732 { 733 __hashtable* __h = static_cast<__hashtable*>(this); 734 __hash_code __code = __h->_M_hash_code(__k); 735 std::size_t __bkt = __h->_M_bucket_index(__k, __code); 736 if (__node_type* __node = __h->_M_find_node(__bkt, __k, __code)) 737 return __node->_M_v().second; 738 739 typename __hashtable::_Scoped_node __node { 740 __h, 741 std::piecewise_construct, 742 std::forward_as_tuple(std::move(__k)), 743 std::tuple<>() 744 }; 745 auto __pos 746 = __h->_M_insert_unique_node(__k, __bkt, __code, __node._M_node); 747 __node._M_node = nullptr; 748 return __pos->second; 749 } 750 751 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 752 typename _H1, typename _H2, typename _Hash, 753 typename _RehashPolicy, typename _Traits> 754 auto 755 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 756 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 757 at(const key_type& __k) 758 -> mapped_type& 759 { 760 __hashtable* __h = static_cast<__hashtable*>(this); 761 __hash_code __code = __h->_M_hash_code(__k); 762 std::size_t __bkt = __h->_M_bucket_index(__k, __code); 763 __node_type* __p = __h->_M_find_node(__bkt, __k, __code); 764 765 if (!__p) 766 __throw_out_of_range(__N("_Map_base::at")); 767 return __p->_M_v().second; 768 } 769 770 template<typename _Key, typename _Pair, typename _Alloc, typename _Equal, 771 typename _H1, typename _H2, typename _Hash, 772 typename _RehashPolicy, typename _Traits> 773 auto 774 _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal, 775 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 776 at(const key_type& __k) const 777 -> const mapped_type& 778 { 779 const __hashtable* __h = static_cast<const __hashtable*>(this); 780 __hash_code __code = __h->_M_hash_code(__k); 781 std::size_t __bkt = __h->_M_bucket_index(__k, __code); 782 __node_type* __p = __h->_M_find_node(__bkt, __k, __code); 783 784 if (!__p) 785 __throw_out_of_range(__N("_Map_base::at")); 786 return __p->_M_v().second; 787 } 788 789 /** 790 * Primary class template _Insert_base. 791 * 792 * Defines @c insert member functions appropriate to all _Hashtables. 793 */ 794 template<typename _Key, typename _Value, typename _Alloc, 795 typename _ExtractKey, typename _Equal, 796 typename _H1, typename _H2, typename _Hash, 797 typename _RehashPolicy, typename _Traits> 798 struct _Insert_base 799 { 800 protected: 801 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, 802 _Equal, _H1, _H2, _Hash, 803 _RehashPolicy, _Traits>; 804 805 using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey, 806 _Equal, _H1, _H2, _Hash, 807 _Traits>; 808 809 using value_type = typename __hashtable_base::value_type; 810 using iterator = typename __hashtable_base::iterator; 811 using const_iterator = typename __hashtable_base::const_iterator; 812 using size_type = typename __hashtable_base::size_type; 813 814 using __unique_keys = typename __hashtable_base::__unique_keys; 815 using __ireturn_type = typename __hashtable_base::__ireturn_type; 816 using __node_type = _Hash_node<_Value, _Traits::__hash_cached::value>; 817 using __node_alloc_type = __alloc_rebind<_Alloc, __node_type>; 818 using __node_gen_type = _AllocNode<__node_alloc_type>; 819 820 __hashtable& 821 _M_conjure_hashtable() 822 { return *(static_cast<__hashtable*>(this)); } 823 824 template<typename _InputIterator, typename _NodeGetter> 825 void 826 _M_insert_range(_InputIterator __first, _InputIterator __last, 827 const _NodeGetter&, true_type); 828 829 template<typename _InputIterator, typename _NodeGetter> 830 void 831 _M_insert_range(_InputIterator __first, _InputIterator __last, 832 const _NodeGetter&, false_type); 833 834 public: 835 __ireturn_type 836 insert(const value_type& __v) 837 { 838 __hashtable& __h = _M_conjure_hashtable(); 839 __node_gen_type __node_gen(__h); 840 return __h._M_insert(__v, __node_gen, __unique_keys()); 841 } 842 843 iterator 844 insert(const_iterator __hint, const value_type& __v) 845 { 846 __hashtable& __h = _M_conjure_hashtable(); 847 __node_gen_type __node_gen(__h); 848 return __h._M_insert(__hint, __v, __node_gen, __unique_keys()); 849 } 850 851 void 852 insert(initializer_list<value_type> __l) 853 { this->insert(__l.begin(), __l.end()); } 854 855 template<typename _InputIterator> 856 void 857 insert(_InputIterator __first, _InputIterator __last) 858 { 859 __hashtable& __h = _M_conjure_hashtable(); 860 __node_gen_type __node_gen(__h); 861 return _M_insert_range(__first, __last, __node_gen, __unique_keys()); 862 } 863 }; 864 865 template<typename _Key, typename _Value, typename _Alloc, 866 typename _ExtractKey, typename _Equal, 867 typename _H1, typename _H2, typename _Hash, 868 typename _RehashPolicy, typename _Traits> 869 template<typename _InputIterator, typename _NodeGetter> 870 void 871 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, 872 _RehashPolicy, _Traits>:: 873 _M_insert_range(_InputIterator __first, _InputIterator __last, 874 const _NodeGetter& __node_gen, true_type) 875 { 876 size_type __n_elt = __detail::__distance_fw(__first, __last); 877 if (__n_elt == 0) 878 return; 879 880 __hashtable& __h = _M_conjure_hashtable(); 881 for (; __first != __last; ++__first) 882 { 883 if (__h._M_insert(*__first, __node_gen, __unique_keys(), 884 __n_elt).second) 885 __n_elt = 1; 886 else if (__n_elt != 1) 887 --__n_elt; 888 } 889 } 890 891 template<typename _Key, typename _Value, typename _Alloc, 892 typename _ExtractKey, typename _Equal, 893 typename _H1, typename _H2, typename _Hash, 894 typename _RehashPolicy, typename _Traits> 895 template<typename _InputIterator, typename _NodeGetter> 896 void 897 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, 898 _RehashPolicy, _Traits>:: 899 _M_insert_range(_InputIterator __first, _InputIterator __last, 900 const _NodeGetter& __node_gen, false_type) 901 { 902 using __rehash_type = typename __hashtable::__rehash_type; 903 using __rehash_state = typename __hashtable::__rehash_state; 904 using pair_type = std::pair<bool, std::size_t>; 905 906 size_type __n_elt = __detail::__distance_fw(__first, __last); 907 if (__n_elt == 0) 908 return; 909 910 __hashtable& __h = _M_conjure_hashtable(); 911 __rehash_type& __rehash = __h._M_rehash_policy; 912 const __rehash_state& __saved_state = __rehash._M_state(); 913 pair_type __do_rehash = __rehash._M_need_rehash(__h._M_bucket_count, 914 __h._M_element_count, 915 __n_elt); 916 917 if (__do_rehash.first) 918 __h._M_rehash(__do_rehash.second, __saved_state); 919 920 for (; __first != __last; ++__first) 921 __h._M_insert(*__first, __node_gen, __unique_keys()); 922 } 923 924 /** 925 * Primary class template _Insert. 926 * 927 * Defines @c insert member functions that depend on _Hashtable policies, 928 * via partial specializations. 929 */ 930 template<typename _Key, typename _Value, typename _Alloc, 931 typename _ExtractKey, typename _Equal, 932 typename _H1, typename _H2, typename _Hash, 933 typename _RehashPolicy, typename _Traits, 934 bool _Constant_iterators = _Traits::__constant_iterators::value> 935 struct _Insert; 936 937 /// Specialization. 938 template<typename _Key, typename _Value, typename _Alloc, 939 typename _ExtractKey, typename _Equal, 940 typename _H1, typename _H2, typename _Hash, 941 typename _RehashPolicy, typename _Traits> 942 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, 943 _RehashPolicy, _Traits, true> 944 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 945 _H1, _H2, _Hash, _RehashPolicy, _Traits> 946 { 947 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey, 948 _Equal, _H1, _H2, _Hash, 949 _RehashPolicy, _Traits>; 950 951 using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey, 952 _Equal, _H1, _H2, _Hash, 953 _Traits>; 954 955 using value_type = typename __base_type::value_type; 956 using iterator = typename __base_type::iterator; 957 using const_iterator = typename __base_type::const_iterator; 958 959 using __unique_keys = typename __base_type::__unique_keys; 960 using __ireturn_type = typename __hashtable_base::__ireturn_type; 961 using __hashtable = typename __base_type::__hashtable; 962 using __node_gen_type = typename __base_type::__node_gen_type; 963 964 using __base_type::insert; 965 966 __ireturn_type 967 insert(value_type&& __v) 968 { 969 __hashtable& __h = this->_M_conjure_hashtable(); 970 __node_gen_type __node_gen(__h); 971 return __h._M_insert(std::move(__v), __node_gen, __unique_keys()); 972 } 973 974 iterator 975 insert(const_iterator __hint, value_type&& __v) 976 { 977 __hashtable& __h = this->_M_conjure_hashtable(); 978 __node_gen_type __node_gen(__h); 979 return __h._M_insert(__hint, std::move(__v), __node_gen, 980 __unique_keys()); 981 } 982 }; 983 984 /// Specialization. 985 template<typename _Key, typename _Value, typename _Alloc, 986 typename _ExtractKey, typename _Equal, 987 typename _H1, typename _H2, typename _Hash, 988 typename _RehashPolicy, typename _Traits> 989 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash, 990 _RehashPolicy, _Traits, false> 991 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 992 _H1, _H2, _Hash, _RehashPolicy, _Traits> 993 { 994 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey, 995 _Equal, _H1, _H2, _Hash, 996 _RehashPolicy, _Traits>; 997 using value_type = typename __base_type::value_type; 998 using iterator = typename __base_type::iterator; 999 using const_iterator = typename __base_type::const_iterator; 1000 1001 using __unique_keys = typename __base_type::__unique_keys; 1002 using __hashtable = typename __base_type::__hashtable; 1003 using __ireturn_type = typename __base_type::__ireturn_type; 1004 1005 using __base_type::insert; 1006 1007 template<typename _Pair> 1008 using __is_cons = std::is_constructible<value_type, _Pair&&>; 1009 1010 template<typename _Pair> 1011 using _IFcons = std::enable_if<__is_cons<_Pair>::value>; 1012 1013 template<typename _Pair> 1014 using _IFconsp = typename _IFcons<_Pair>::type; 1015 1016 template<typename _Pair, typename = _IFconsp<_Pair>> 1017 __ireturn_type 1018 insert(_Pair&& __v) 1019 { 1020 __hashtable& __h = this->_M_conjure_hashtable(); 1021 return __h._M_emplace(__unique_keys(), std::forward<_Pair>(__v)); 1022 } 1023 1024 template<typename _Pair, typename = _IFconsp<_Pair>> 1025 iterator 1026 insert(const_iterator __hint, _Pair&& __v) 1027 { 1028 __hashtable& __h = this->_M_conjure_hashtable(); 1029 return __h._M_emplace(__hint, __unique_keys(), 1030 std::forward<_Pair>(__v)); 1031 } 1032 }; 1033 1034 template<typename _Policy> 1035 using __has_load_factor = typename _Policy::__has_load_factor; 1036 1037 /** 1038 * Primary class template _Rehash_base. 1039 * 1040 * Give hashtable the max_load_factor functions and reserve iff the 1041 * rehash policy supports it. 1042 */ 1043 template<typename _Key, typename _Value, typename _Alloc, 1044 typename _ExtractKey, typename _Equal, 1045 typename _H1, typename _H2, typename _Hash, 1046 typename _RehashPolicy, typename _Traits, 1047 typename = 1048 __detected_or_t<false_type, __has_load_factor, _RehashPolicy>> 1049 struct _Rehash_base; 1050 1051 /// Specialization when rehash policy doesn't provide load factor management. 1052 template<typename _Key, typename _Value, typename _Alloc, 1053 typename _ExtractKey, typename _Equal, 1054 typename _H1, typename _H2, typename _Hash, 1055 typename _RehashPolicy, typename _Traits> 1056 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1057 _H1, _H2, _Hash, _RehashPolicy, _Traits, 1058 false_type> 1059 { 1060 }; 1061 1062 /// Specialization when rehash policy provide load factor management. 1063 template<typename _Key, typename _Value, typename _Alloc, 1064 typename _ExtractKey, typename _Equal, 1065 typename _H1, typename _H2, typename _Hash, 1066 typename _RehashPolicy, typename _Traits> 1067 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1068 _H1, _H2, _Hash, _RehashPolicy, _Traits, 1069 true_type> 1070 { 1071 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, 1072 _Equal, _H1, _H2, _Hash, 1073 _RehashPolicy, _Traits>; 1074 1075 float 1076 max_load_factor() const noexcept 1077 { 1078 const __hashtable* __this = static_cast<const __hashtable*>(this); 1079 return __this->__rehash_policy().max_load_factor(); 1080 } 1081 1082 void 1083 max_load_factor(float __z) 1084 { 1085 __hashtable* __this = static_cast<__hashtable*>(this); 1086 __this->__rehash_policy(_RehashPolicy(__z)); 1087 } 1088 1089 void 1090 reserve(std::size_t __n) 1091 { 1092 __hashtable* __this = static_cast<__hashtable*>(this); 1093 __this->rehash(__this->__rehash_policy()._M_bkt_for_elements(__n)); 1094 } 1095 }; 1096 1097 /** 1098 * Primary class template _Hashtable_ebo_helper. 1099 * 1100 * Helper class using EBO when it is not forbidden (the type is not 1101 * final) and when it is worth it (the type is empty.) 1102 */ 1103 template<int _Nm, typename _Tp, 1104 bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)> 1105 struct _Hashtable_ebo_helper; 1106 1107 /// Specialization using EBO. 1108 template<int _Nm, typename _Tp> 1109 struct _Hashtable_ebo_helper<_Nm, _Tp, true> 1110 : private _Tp 1111 { 1112 _Hashtable_ebo_helper() = default; 1113 1114 template<typename _OtherTp> 1115 _Hashtable_ebo_helper(_OtherTp&& __tp) 1116 : _Tp(std::forward<_OtherTp>(__tp)) 1117 { } 1118 1119 const _Tp& _M_cget() const { return static_cast<const _Tp&>(*this); } 1120 _Tp& _M_get() { return static_cast<_Tp&>(*this); } 1121 }; 1122 1123 /// Specialization not using EBO. 1124 template<int _Nm, typename _Tp> 1125 struct _Hashtable_ebo_helper<_Nm, _Tp, false> 1126 { 1127 _Hashtable_ebo_helper() = default; 1128 1129 template<typename _OtherTp> 1130 _Hashtable_ebo_helper(_OtherTp&& __tp) 1131 : _M_tp(std::forward<_OtherTp>(__tp)) 1132 { } 1133 1134 const _Tp& _M_cget() const { return _M_tp; } 1135 _Tp& _M_get() { return _M_tp; } 1136 1137 private: 1138 _Tp _M_tp; 1139 }; 1140 1141 /** 1142 * Primary class template _Local_iterator_base. 1143 * 1144 * Base class for local iterators, used to iterate within a bucket 1145 * but not between buckets. 1146 */ 1147 template<typename _Key, typename _Value, typename _ExtractKey, 1148 typename _H1, typename _H2, typename _Hash, 1149 bool __cache_hash_code> 1150 struct _Local_iterator_base; 1151 1152 /** 1153 * Primary class template _Hash_code_base. 1154 * 1155 * Encapsulates two policy issues that aren't quite orthogonal. 1156 * (1) the difference between using a ranged hash function and using 1157 * the combination of a hash function and a range-hashing function. 1158 * In the former case we don't have such things as hash codes, so 1159 * we have a dummy type as placeholder. 1160 * (2) Whether or not we cache hash codes. Caching hash codes is 1161 * meaningless if we have a ranged hash function. 1162 * 1163 * We also put the key extraction objects here, for convenience. 1164 * Each specialization derives from one or more of the template 1165 * parameters to benefit from Ebo. This is important as this type 1166 * is inherited in some cases by the _Local_iterator_base type used 1167 * to implement local_iterator and const_local_iterator. As with 1168 * any iterator type we prefer to make it as small as possible. 1169 * 1170 * Primary template is unused except as a hook for specializations. 1171 */ 1172 template<typename _Key, typename _Value, typename _ExtractKey, 1173 typename _H1, typename _H2, typename _Hash, 1174 bool __cache_hash_code> 1175 struct _Hash_code_base; 1176 1177 /// Specialization: ranged hash function, no caching hash codes. H1 1178 /// and H2 are provided but ignored. We define a dummy hash code type. 1179 template<typename _Key, typename _Value, typename _ExtractKey, 1180 typename _H1, typename _H2, typename _Hash> 1181 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false> 1182 : private _Hashtable_ebo_helper<0, _ExtractKey>, 1183 private _Hashtable_ebo_helper<1, _Hash> 1184 { 1185 private: 1186 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>; 1187 using __ebo_hash = _Hashtable_ebo_helper<1, _Hash>; 1188 1189 protected: 1190 typedef void* __hash_code; 1191 typedef _Hash_node<_Value, false> __node_type; 1192 1193 // We need the default constructor for the local iterators and _Hashtable 1194 // default constructor. 1195 _Hash_code_base() = default; 1196 1197 _Hash_code_base(const _ExtractKey& __ex, const _H1&, const _H2&, 1198 const _Hash& __h) 1199 : __ebo_extract_key(__ex), __ebo_hash(__h) { } 1200 1201 __hash_code 1202 _M_hash_code(const _Key& __key) const 1203 { return 0; } 1204 1205 std::size_t 1206 _M_bucket_index(const _Key& __k, __hash_code, 1207 std::size_t __bkt_count) const 1208 { return _M_ranged_hash()(__k, __bkt_count); } 1209 1210 std::size_t 1211 _M_bucket_index(const __node_type* __p, std::size_t __bkt_count) const 1212 noexcept( noexcept(declval<const _Hash&>()(declval<const _Key&>(), 1213 (std::size_t)0)) ) 1214 { return _M_ranged_hash()(_M_extract()(__p->_M_v()), __bkt_count); } 1215 1216 void 1217 _M_store_code(__node_type*, __hash_code) const 1218 { } 1219 1220 void 1221 _M_copy_code(__node_type*, const __node_type*) const 1222 { } 1223 1224 void 1225 _M_swap(_Hash_code_base& __x) 1226 { 1227 std::swap(__ebo_extract_key::_M_get(), 1228 __x.__ebo_extract_key::_M_get()); 1229 std::swap(__ebo_hash::_M_get(), __x.__ebo_hash::_M_get()); 1230 } 1231 1232 const _ExtractKey& 1233 _M_extract() const { return __ebo_extract_key::_M_cget(); } 1234 1235 const _Hash& 1236 _M_ranged_hash() const { return __ebo_hash::_M_cget(); } 1237 }; 1238 1239 // No specialization for ranged hash function while caching hash codes. 1240 // That combination is meaningless, and trying to do it is an error. 1241 1242 /// Specialization: ranged hash function, cache hash codes. This 1243 /// combination is meaningless, so we provide only a declaration 1244 /// and no definition. 1245 template<typename _Key, typename _Value, typename _ExtractKey, 1246 typename _H1, typename _H2, typename _Hash> 1247 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>; 1248 1249 /// Specialization: hash function and range-hashing function, no 1250 /// caching of hash codes. 1251 /// Provides typedef and accessor required by C++ 11. 1252 template<typename _Key, typename _Value, typename _ExtractKey, 1253 typename _H1, typename _H2> 1254 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, 1255 _Default_ranged_hash, false> 1256 : private _Hashtable_ebo_helper<0, _ExtractKey>, 1257 private _Hashtable_ebo_helper<1, _H1>, 1258 private _Hashtable_ebo_helper<2, _H2> 1259 { 1260 private: 1261 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>; 1262 using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>; 1263 using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>; 1264 1265 // Gives the local iterator implementation access to _M_bucket_index(). 1266 friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, 1267 _Default_ranged_hash, false>; 1268 1269 public: 1270 typedef _H1 hasher; 1271 1272 hasher 1273 hash_function() const 1274 { return _M_h1(); } 1275 1276 protected: 1277 typedef std::size_t __hash_code; 1278 typedef _Hash_node<_Value, false> __node_type; 1279 1280 // We need the default constructor for the local iterators and _Hashtable 1281 // default constructor. 1282 _Hash_code_base() = default; 1283 1284 _Hash_code_base(const _ExtractKey& __ex, 1285 const _H1& __h1, const _H2& __h2, 1286 const _Default_ranged_hash&) 1287 : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { } 1288 1289 __hash_code 1290 _M_hash_code(const _Key& __k) const 1291 { 1292 static_assert(__is_invocable<const _H1&, const _Key&>{}, 1293 "hash function must be invocable with an argument of key type"); 1294 return _M_h1()(__k); 1295 } 1296 1297 std::size_t 1298 _M_bucket_index(const _Key&, __hash_code __c, 1299 std::size_t __bkt_count) const 1300 { return _M_h2()(__c, __bkt_count); } 1301 1302 std::size_t 1303 _M_bucket_index(const __node_type* __p, std::size_t __bkt_count) const 1304 noexcept( noexcept(declval<const _H1&>()(declval<const _Key&>())) 1305 && noexcept(declval<const _H2&>()((__hash_code)0, 1306 (std::size_t)0)) ) 1307 { return _M_h2()(_M_h1()(_M_extract()(__p->_M_v())), __bkt_count); } 1308 1309 void 1310 _M_store_code(__node_type*, __hash_code) const 1311 { } 1312 1313 void 1314 _M_copy_code(__node_type*, const __node_type*) const 1315 { } 1316 1317 void 1318 _M_swap(_Hash_code_base& __x) 1319 { 1320 std::swap(__ebo_extract_key::_M_get(), 1321 __x.__ebo_extract_key::_M_get()); 1322 std::swap(__ebo_h1::_M_get(), __x.__ebo_h1::_M_get()); 1323 std::swap(__ebo_h2::_M_get(), __x.__ebo_h2::_M_get()); 1324 } 1325 1326 const _ExtractKey& 1327 _M_extract() const { return __ebo_extract_key::_M_cget(); } 1328 1329 const _H1& 1330 _M_h1() const { return __ebo_h1::_M_cget(); } 1331 1332 const _H2& 1333 _M_h2() const { return __ebo_h2::_M_cget(); } 1334 }; 1335 1336 /// Specialization: hash function and range-hashing function, 1337 /// caching hash codes. H is provided but ignored. Provides 1338 /// typedef and accessor required by C++ 11. 1339 template<typename _Key, typename _Value, typename _ExtractKey, 1340 typename _H1, typename _H2> 1341 struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, 1342 _Default_ranged_hash, true> 1343 : private _Hashtable_ebo_helper<0, _ExtractKey>, 1344 private _Hashtable_ebo_helper<1, _H1>, 1345 private _Hashtable_ebo_helper<2, _H2> 1346 { 1347 private: 1348 // Gives the local iterator implementation access to _M_h2(). 1349 friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, 1350 _Default_ranged_hash, true>; 1351 1352 using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>; 1353 using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>; 1354 using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>; 1355 1356 public: 1357 typedef _H1 hasher; 1358 1359 hasher 1360 hash_function() const 1361 { return _M_h1(); } 1362 1363 protected: 1364 typedef std::size_t __hash_code; 1365 typedef _Hash_node<_Value, true> __node_type; 1366 1367 // We need the default constructor for _Hashtable default constructor. 1368 _Hash_code_base() = default; 1369 _Hash_code_base(const _ExtractKey& __ex, 1370 const _H1& __h1, const _H2& __h2, 1371 const _Default_ranged_hash&) 1372 : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { } 1373 1374 __hash_code 1375 _M_hash_code(const _Key& __k) const 1376 { 1377 static_assert(__is_invocable<const _H1&, const _Key&>{}, 1378 "hash function must be invocable with an argument of key type"); 1379 return _M_h1()(__k); 1380 } 1381 1382 std::size_t 1383 _M_bucket_index(const _Key&, __hash_code __c, 1384 std::size_t __bkt_count) const 1385 { return _M_h2()(__c, __bkt_count); } 1386 1387 std::size_t 1388 _M_bucket_index(const __node_type* __p, std::size_t __bkt_count) const 1389 noexcept( noexcept(declval<const _H2&>()((__hash_code)0, 1390 (std::size_t)0)) ) 1391 { return _M_h2()(__p->_M_hash_code, __bkt_count); } 1392 1393 void 1394 _M_store_code(__node_type* __n, __hash_code __c) const 1395 { __n->_M_hash_code = __c; } 1396 1397 void 1398 _M_copy_code(__node_type* __to, const __node_type* __from) const 1399 { __to->_M_hash_code = __from->_M_hash_code; } 1400 1401 void 1402 _M_swap(_Hash_code_base& __x) 1403 { 1404 std::swap(__ebo_extract_key::_M_get(), 1405 __x.__ebo_extract_key::_M_get()); 1406 std::swap(__ebo_h1::_M_get(), __x.__ebo_h1::_M_get()); 1407 std::swap(__ebo_h2::_M_get(), __x.__ebo_h2::_M_get()); 1408 } 1409 1410 const _ExtractKey& 1411 _M_extract() const { return __ebo_extract_key::_M_cget(); } 1412 1413 const _H1& 1414 _M_h1() const { return __ebo_h1::_M_cget(); } 1415 1416 const _H2& 1417 _M_h2() const { return __ebo_h2::_M_cget(); } 1418 }; 1419 1420 /// Partial specialization used when nodes contain a cached hash code. 1421 template<typename _Key, typename _Value, typename _ExtractKey, 1422 typename _H1, typename _H2, typename _Hash> 1423 struct _Local_iterator_base<_Key, _Value, _ExtractKey, 1424 _H1, _H2, _Hash, true> 1425 : private _Hashtable_ebo_helper<0, _H2> 1426 { 1427 protected: 1428 using __base_type = _Hashtable_ebo_helper<0, _H2>; 1429 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, 1430 _H1, _H2, _Hash, true>; 1431 1432 _Local_iterator_base() = default; 1433 _Local_iterator_base(const __hash_code_base& __base, 1434 _Hash_node<_Value, true>* __p, 1435 std::size_t __bkt, std::size_t __bkt_count) 1436 : __base_type(__base._M_h2()), 1437 _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { } 1438 1439 void 1440 _M_incr() 1441 { 1442 _M_cur = _M_cur->_M_next(); 1443 if (_M_cur) 1444 { 1445 std::size_t __bkt 1446 = __base_type::_M_get()(_M_cur->_M_hash_code, 1447 _M_bucket_count); 1448 if (__bkt != _M_bucket) 1449 _M_cur = nullptr; 1450 } 1451 } 1452 1453 _Hash_node<_Value, true>* _M_cur; 1454 std::size_t _M_bucket; 1455 std::size_t _M_bucket_count; 1456 1457 public: 1458 const void* 1459 _M_curr() const { return _M_cur; } // for equality ops 1460 1461 std::size_t 1462 _M_get_bucket() const { return _M_bucket; } // for debug mode 1463 }; 1464 1465 // Uninitialized storage for a _Hash_code_base. 1466 // This type is DefaultConstructible and Assignable even if the 1467 // _Hash_code_base type isn't, so that _Local_iterator_base<..., false> 1468 // can be DefaultConstructible and Assignable. 1469 template<typename _Tp, bool _IsEmpty = std::is_empty<_Tp>::value> 1470 struct _Hash_code_storage 1471 { 1472 __gnu_cxx::__aligned_buffer<_Tp> _M_storage; 1473 1474 _Tp* 1475 _M_h() { return _M_storage._M_ptr(); } 1476 1477 const _Tp* 1478 _M_h() const { return _M_storage._M_ptr(); } 1479 }; 1480 1481 // Empty partial specialization for empty _Hash_code_base types. 1482 template<typename _Tp> 1483 struct _Hash_code_storage<_Tp, true> 1484 { 1485 static_assert( std::is_empty<_Tp>::value, "Type must be empty" ); 1486 1487 // As _Tp is an empty type there will be no bytes written/read through 1488 // the cast pointer, so no strict-aliasing violation. 1489 _Tp* 1490 _M_h() { return reinterpret_cast<_Tp*>(this); } 1491 1492 const _Tp* 1493 _M_h() const { return reinterpret_cast<const _Tp*>(this); } 1494 }; 1495 1496 template<typename _Key, typename _Value, typename _ExtractKey, 1497 typename _H1, typename _H2, typename _Hash> 1498 using __hash_code_for_local_iter 1499 = _Hash_code_storage<_Hash_code_base<_Key, _Value, _ExtractKey, 1500 _H1, _H2, _Hash, false>>; 1501 1502 // Partial specialization used when hash codes are not cached 1503 template<typename _Key, typename _Value, typename _ExtractKey, 1504 typename _H1, typename _H2, typename _Hash> 1505 struct _Local_iterator_base<_Key, _Value, _ExtractKey, 1506 _H1, _H2, _Hash, false> 1507 : __hash_code_for_local_iter<_Key, _Value, _ExtractKey, _H1, _H2, _Hash> 1508 { 1509 protected: 1510 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, 1511 _H1, _H2, _Hash, false>; 1512 1513 _Local_iterator_base() : _M_bucket_count(-1) { } 1514 1515 _Local_iterator_base(const __hash_code_base& __base, 1516 _Hash_node<_Value, false>* __p, 1517 std::size_t __bkt, std::size_t __bkt_count) 1518 : _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) 1519 { _M_init(__base); } 1520 1521 ~_Local_iterator_base() 1522 { 1523 if (_M_bucket_count != -1) 1524 _M_destroy(); 1525 } 1526 1527 _Local_iterator_base(const _Local_iterator_base& __iter) 1528 : _M_cur(__iter._M_cur), _M_bucket(__iter._M_bucket), 1529 _M_bucket_count(__iter._M_bucket_count) 1530 { 1531 if (_M_bucket_count != -1) 1532 _M_init(*__iter._M_h()); 1533 } 1534 1535 _Local_iterator_base& 1536 operator=(const _Local_iterator_base& __iter) 1537 { 1538 if (_M_bucket_count != -1) 1539 _M_destroy(); 1540 _M_cur = __iter._M_cur; 1541 _M_bucket = __iter._M_bucket; 1542 _M_bucket_count = __iter._M_bucket_count; 1543 if (_M_bucket_count != -1) 1544 _M_init(*__iter._M_h()); 1545 return *this; 1546 } 1547 1548 void 1549 _M_incr() 1550 { 1551 _M_cur = _M_cur->_M_next(); 1552 if (_M_cur) 1553 { 1554 std::size_t __bkt = this->_M_h()->_M_bucket_index(_M_cur, 1555 _M_bucket_count); 1556 if (__bkt != _M_bucket) 1557 _M_cur = nullptr; 1558 } 1559 } 1560 1561 _Hash_node<_Value, false>* _M_cur; 1562 std::size_t _M_bucket; 1563 std::size_t _M_bucket_count; 1564 1565 void 1566 _M_init(const __hash_code_base& __base) 1567 { ::new(this->_M_h()) __hash_code_base(__base); } 1568 1569 void 1570 _M_destroy() { this->_M_h()->~__hash_code_base(); } 1571 1572 public: 1573 const void* 1574 _M_curr() const { return _M_cur; } // for equality ops and debug mode 1575 1576 std::size_t 1577 _M_get_bucket() const { return _M_bucket; } // for debug mode 1578 }; 1579 1580 template<typename _Key, typename _Value, typename _ExtractKey, 1581 typename _H1, typename _H2, typename _Hash, bool __cache> 1582 inline bool 1583 operator==(const _Local_iterator_base<_Key, _Value, _ExtractKey, 1584 _H1, _H2, _Hash, __cache>& __x, 1585 const _Local_iterator_base<_Key, _Value, _ExtractKey, 1586 _H1, _H2, _Hash, __cache>& __y) 1587 { return __x._M_curr() == __y._M_curr(); } 1588 1589 template<typename _Key, typename _Value, typename _ExtractKey, 1590 typename _H1, typename _H2, typename _Hash, bool __cache> 1591 inline bool 1592 operator!=(const _Local_iterator_base<_Key, _Value, _ExtractKey, 1593 _H1, _H2, _Hash, __cache>& __x, 1594 const _Local_iterator_base<_Key, _Value, _ExtractKey, 1595 _H1, _H2, _Hash, __cache>& __y) 1596 { return __x._M_curr() != __y._M_curr(); } 1597 1598 /// local iterators 1599 template<typename _Key, typename _Value, typename _ExtractKey, 1600 typename _H1, typename _H2, typename _Hash, 1601 bool __constant_iterators, bool __cache> 1602 struct _Local_iterator 1603 : public _Local_iterator_base<_Key, _Value, _ExtractKey, 1604 _H1, _H2, _Hash, __cache> 1605 { 1606 private: 1607 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey, 1608 _H1, _H2, _Hash, __cache>; 1609 using __hash_code_base = typename __base_type::__hash_code_base; 1610 public: 1611 typedef _Value value_type; 1612 typedef typename std::conditional<__constant_iterators, 1613 const _Value*, _Value*>::type 1614 pointer; 1615 typedef typename std::conditional<__constant_iterators, 1616 const _Value&, _Value&>::type 1617 reference; 1618 typedef std::ptrdiff_t difference_type; 1619 typedef std::forward_iterator_tag iterator_category; 1620 1621 _Local_iterator() = default; 1622 1623 _Local_iterator(const __hash_code_base& __base, 1624 _Hash_node<_Value, __cache>* __n, 1625 std::size_t __bkt, std::size_t __bkt_count) 1626 : __base_type(__base, __n, __bkt, __bkt_count) 1627 { } 1628 1629 reference 1630 operator*() const 1631 { return this->_M_cur->_M_v(); } 1632 1633 pointer 1634 operator->() const 1635 { return this->_M_cur->_M_valptr(); } 1636 1637 _Local_iterator& 1638 operator++() 1639 { 1640 this->_M_incr(); 1641 return *this; 1642 } 1643 1644 _Local_iterator 1645 operator++(int) 1646 { 1647 _Local_iterator __tmp(*this); 1648 this->_M_incr(); 1649 return __tmp; 1650 } 1651 }; 1652 1653 /// local const_iterators 1654 template<typename _Key, typename _Value, typename _ExtractKey, 1655 typename _H1, typename _H2, typename _Hash, 1656 bool __constant_iterators, bool __cache> 1657 struct _Local_const_iterator 1658 : public _Local_iterator_base<_Key, _Value, _ExtractKey, 1659 _H1, _H2, _Hash, __cache> 1660 { 1661 private: 1662 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey, 1663 _H1, _H2, _Hash, __cache>; 1664 using __hash_code_base = typename __base_type::__hash_code_base; 1665 1666 public: 1667 typedef _Value value_type; 1668 typedef const _Value* pointer; 1669 typedef const _Value& reference; 1670 typedef std::ptrdiff_t difference_type; 1671 typedef std::forward_iterator_tag iterator_category; 1672 1673 _Local_const_iterator() = default; 1674 1675 _Local_const_iterator(const __hash_code_base& __base, 1676 _Hash_node<_Value, __cache>* __n, 1677 std::size_t __bkt, std::size_t __bkt_count) 1678 : __base_type(__base, __n, __bkt, __bkt_count) 1679 { } 1680 1681 _Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey, 1682 _H1, _H2, _Hash, 1683 __constant_iterators, 1684 __cache>& __x) 1685 : __base_type(__x) 1686 { } 1687 1688 reference 1689 operator*() const 1690 { return this->_M_cur->_M_v(); } 1691 1692 pointer 1693 operator->() const 1694 { return this->_M_cur->_M_valptr(); } 1695 1696 _Local_const_iterator& 1697 operator++() 1698 { 1699 this->_M_incr(); 1700 return *this; 1701 } 1702 1703 _Local_const_iterator 1704 operator++(int) 1705 { 1706 _Local_const_iterator __tmp(*this); 1707 this->_M_incr(); 1708 return __tmp; 1709 } 1710 }; 1711 1712 /** 1713 * Primary class template _Hashtable_base. 1714 * 1715 * Helper class adding management of _Equal functor to 1716 * _Hash_code_base type. 1717 * 1718 * Base class templates are: 1719 * - __detail::_Hash_code_base 1720 * - __detail::_Hashtable_ebo_helper 1721 */ 1722 template<typename _Key, typename _Value, 1723 typename _ExtractKey, typename _Equal, 1724 typename _H1, typename _H2, typename _Hash, typename _Traits> 1725 struct _Hashtable_base 1726 : public _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, 1727 _Traits::__hash_cached::value>, 1728 private _Hashtable_ebo_helper<0, _Equal> 1729 { 1730 public: 1731 typedef _Key key_type; 1732 typedef _Value value_type; 1733 typedef _Equal key_equal; 1734 typedef std::size_t size_type; 1735 typedef std::ptrdiff_t difference_type; 1736 1737 using __traits_type = _Traits; 1738 using __hash_cached = typename __traits_type::__hash_cached; 1739 using __constant_iterators = typename __traits_type::__constant_iterators; 1740 using __unique_keys = typename __traits_type::__unique_keys; 1741 1742 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, 1743 _H1, _H2, _Hash, 1744 __hash_cached::value>; 1745 1746 using __hash_code = typename __hash_code_base::__hash_code; 1747 using __node_type = typename __hash_code_base::__node_type; 1748 1749 using iterator = __detail::_Node_iterator<value_type, 1750 __constant_iterators::value, 1751 __hash_cached::value>; 1752 1753 using const_iterator = __detail::_Node_const_iterator<value_type, 1754 __constant_iterators::value, 1755 __hash_cached::value>; 1756 1757 using local_iterator = __detail::_Local_iterator<key_type, value_type, 1758 _ExtractKey, _H1, _H2, _Hash, 1759 __constant_iterators::value, 1760 __hash_cached::value>; 1761 1762 using const_local_iterator = __detail::_Local_const_iterator<key_type, 1763 value_type, 1764 _ExtractKey, _H1, _H2, _Hash, 1765 __constant_iterators::value, 1766 __hash_cached::value>; 1767 1768 using __ireturn_type = typename std::conditional<__unique_keys::value, 1769 std::pair<iterator, bool>, 1770 iterator>::type; 1771 private: 1772 using _EqualEBO = _Hashtable_ebo_helper<0, _Equal>; 1773 1774 template<typename _NodeT> 1775 struct _Equal_hash_code 1776 { 1777 static bool 1778 _S_equals(__hash_code, const _NodeT&) 1779 { return true; } 1780 }; 1781 1782 template<typename _Ptr2> 1783 struct _Equal_hash_code<_Hash_node<_Ptr2, true>> 1784 { 1785 static bool 1786 _S_equals(__hash_code __c, const _Hash_node<_Ptr2, true>& __n) 1787 { return __c == __n._M_hash_code; } 1788 }; 1789 1790 protected: 1791 _Hashtable_base() = default; 1792 _Hashtable_base(const _ExtractKey& __ex, const _H1& __h1, const _H2& __h2, 1793 const _Hash& __hash, const _Equal& __eq) 1794 : __hash_code_base(__ex, __h1, __h2, __hash), _EqualEBO(__eq) 1795 { } 1796 1797 bool 1798 _M_equals(const _Key& __k, __hash_code __c, __node_type* __n) const 1799 { 1800 static_assert(__is_invocable<const _Equal&, const _Key&, const _Key&>{}, 1801 "key equality predicate must be invocable with two arguments of " 1802 "key type"); 1803 return _Equal_hash_code<__node_type>::_S_equals(__c, *__n) 1804 && _M_eq()(__k, this->_M_extract()(__n->_M_v())); 1805 } 1806 1807 void 1808 _M_swap(_Hashtable_base& __x) 1809 { 1810 __hash_code_base::_M_swap(__x); 1811 std::swap(_EqualEBO::_M_get(), __x._EqualEBO::_M_get()); 1812 } 1813 1814 const _Equal& 1815 _M_eq() const { return _EqualEBO::_M_cget(); } 1816 }; 1817 1818 /** 1819 * Primary class template _Equality. 1820 * 1821 * This is for implementing equality comparison for unordered 1822 * containers, per N3068, by John Lakos and Pablo Halpern. 1823 * Algorithmically, we follow closely the reference implementations 1824 * therein. 1825 */ 1826 template<typename _Key, typename _Value, typename _Alloc, 1827 typename _ExtractKey, typename _Equal, 1828 typename _H1, typename _H2, typename _Hash, 1829 typename _RehashPolicy, typename _Traits, 1830 bool _Unique_keys = _Traits::__unique_keys::value> 1831 struct _Equality; 1832 1833 /// unordered_map and unordered_set specializations. 1834 template<typename _Key, typename _Value, typename _Alloc, 1835 typename _ExtractKey, typename _Equal, 1836 typename _H1, typename _H2, typename _Hash, 1837 typename _RehashPolicy, typename _Traits> 1838 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1839 _H1, _H2, _Hash, _RehashPolicy, _Traits, true> 1840 { 1841 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1842 _H1, _H2, _Hash, _RehashPolicy, _Traits>; 1843 1844 bool 1845 _M_equal(const __hashtable&) const; 1846 }; 1847 1848 template<typename _Key, typename _Value, typename _Alloc, 1849 typename _ExtractKey, typename _Equal, 1850 typename _H1, typename _H2, typename _Hash, 1851 typename _RehashPolicy, typename _Traits> 1852 bool 1853 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1854 _H1, _H2, _Hash, _RehashPolicy, _Traits, true>:: 1855 _M_equal(const __hashtable& __other) const 1856 { 1857 using __node_base = typename __hashtable::__node_base; 1858 using __node_type = typename __hashtable::__node_type; 1859 const __hashtable* __this = static_cast<const __hashtable*>(this); 1860 if (__this->size() != __other.size()) 1861 return false; 1862 1863 for (auto __itx = __this->begin(); __itx != __this->end(); ++__itx) 1864 { 1865 std::size_t __ybkt = __other._M_bucket_index(__itx._M_cur); 1866 __node_base* __prev_n = __other._M_buckets[__ybkt]; 1867 if (!__prev_n) 1868 return false; 1869 1870 for (__node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt);; 1871 __n = __n->_M_next()) 1872 { 1873 if (__n->_M_v() == *__itx) 1874 break; 1875 1876 if (!__n->_M_nxt 1877 || __other._M_bucket_index(__n->_M_next()) != __ybkt) 1878 return false; 1879 } 1880 } 1881 1882 return true; 1883 } 1884 1885 /// unordered_multiset and unordered_multimap specializations. 1886 template<typename _Key, typename _Value, typename _Alloc, 1887 typename _ExtractKey, typename _Equal, 1888 typename _H1, typename _H2, typename _Hash, 1889 typename _RehashPolicy, typename _Traits> 1890 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1891 _H1, _H2, _Hash, _RehashPolicy, _Traits, false> 1892 { 1893 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1894 _H1, _H2, _Hash, _RehashPolicy, _Traits>; 1895 1896 bool 1897 _M_equal(const __hashtable&) const; 1898 }; 1899 1900 template<typename _Key, typename _Value, typename _Alloc, 1901 typename _ExtractKey, typename _Equal, 1902 typename _H1, typename _H2, typename _Hash, 1903 typename _RehashPolicy, typename _Traits> 1904 bool 1905 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1906 _H1, _H2, _Hash, _RehashPolicy, _Traits, false>:: 1907 _M_equal(const __hashtable& __other) const 1908 { 1909 using __node_base = typename __hashtable::__node_base; 1910 using __node_type = typename __hashtable::__node_type; 1911 const __hashtable* __this = static_cast<const __hashtable*>(this); 1912 if (__this->size() != __other.size()) 1913 return false; 1914 1915 for (auto __itx = __this->begin(); __itx != __this->end();) 1916 { 1917 std::size_t __x_count = 1; 1918 auto __itx_end = __itx; 1919 for (++__itx_end; __itx_end != __this->end() 1920 && __this->key_eq()(_ExtractKey()(*__itx), 1921 _ExtractKey()(*__itx_end)); 1922 ++__itx_end) 1923 ++__x_count; 1924 1925 std::size_t __ybkt = __other._M_bucket_index(__itx._M_cur); 1926 __node_base* __y_prev_n = __other._M_buckets[__ybkt]; 1927 if (!__y_prev_n) 1928 return false; 1929 1930 __node_type* __y_n = static_cast<__node_type*>(__y_prev_n->_M_nxt); 1931 for (;; __y_n = __y_n->_M_next()) 1932 { 1933 if (__this->key_eq()(_ExtractKey()(__y_n->_M_v()), 1934 _ExtractKey()(*__itx))) 1935 break; 1936 1937 if (!__y_n->_M_nxt 1938 || __other._M_bucket_index(__y_n->_M_next()) != __ybkt) 1939 return false; 1940 } 1941 1942 typename __hashtable::const_iterator __ity(__y_n); 1943 for (auto __ity_end = __ity; __ity_end != __other.end(); ++__ity_end) 1944 if (--__x_count == 0) 1945 break; 1946 1947 if (__x_count != 0) 1948 return false; 1949 1950 if (!std::is_permutation(__itx, __itx_end, __ity)) 1951 return false; 1952 1953 __itx = __itx_end; 1954 } 1955 return true; 1956 } 1957 1958 /** 1959 * This type deals with all allocation and keeps an allocator instance 1960 * through inheritance to benefit from EBO when possible. 1961 */ 1962 template<typename _NodeAlloc> 1963 struct _Hashtable_alloc : private _Hashtable_ebo_helper<0, _NodeAlloc> 1964 { 1965 private: 1966 using __ebo_node_alloc = _Hashtable_ebo_helper<0, _NodeAlloc>; 1967 public: 1968 using __node_type = typename _NodeAlloc::value_type; 1969 using __node_alloc_type = _NodeAlloc; 1970 // Use __gnu_cxx to benefit from _S_always_equal and al. 1971 using __node_alloc_traits = __gnu_cxx::__alloc_traits<__node_alloc_type>; 1972 1973 using __value_alloc_traits = typename __node_alloc_traits::template 1974 rebind_traits<typename __node_type::value_type>; 1975 1976 using __node_base = __detail::_Hash_node_base; 1977 using __bucket_type = __node_base*; 1978 using __bucket_alloc_type = 1979 __alloc_rebind<__node_alloc_type, __bucket_type>; 1980 using __bucket_alloc_traits = std::allocator_traits<__bucket_alloc_type>; 1981 1982 _Hashtable_alloc() = default; 1983 _Hashtable_alloc(const _Hashtable_alloc&) = default; 1984 _Hashtable_alloc(_Hashtable_alloc&&) = default; 1985 1986 template<typename _Alloc> 1987 _Hashtable_alloc(_Alloc&& __a) 1988 : __ebo_node_alloc(std::forward<_Alloc>(__a)) 1989 { } 1990 1991 __node_alloc_type& 1992 _M_node_allocator() 1993 { return __ebo_node_alloc::_M_get(); } 1994 1995 const __node_alloc_type& 1996 _M_node_allocator() const 1997 { return __ebo_node_alloc::_M_cget(); } 1998 1999 // Allocate a node and construct an element within it. 2000 template<typename... _Args> 2001 __node_type* 2002 _M_allocate_node(_Args&&... __args); 2003 2004 // Destroy the element within a node and deallocate the node. 2005 void 2006 _M_deallocate_node(__node_type* __n); 2007 2008 // Deallocate a node. 2009 void 2010 _M_deallocate_node_ptr(__node_type* __n); 2011 2012 // Deallocate the linked list of nodes pointed to by __n. 2013 // The elements within the nodes are destroyed. 2014 void 2015 _M_deallocate_nodes(__node_type* __n); 2016 2017 __bucket_type* 2018 _M_allocate_buckets(std::size_t __bkt_count); 2019 2020 void 2021 _M_deallocate_buckets(__bucket_type*, std::size_t __bkt_count); 2022 }; 2023 2024 // Definitions of class template _Hashtable_alloc's out-of-line member 2025 // functions. 2026 template<typename _NodeAlloc> 2027 template<typename... _Args> 2028 auto 2029 _Hashtable_alloc<_NodeAlloc>::_M_allocate_node(_Args&&... __args) 2030 -> __node_type* 2031 { 2032 auto __nptr = __node_alloc_traits::allocate(_M_node_allocator(), 1); 2033 __node_type* __n = std::__to_address(__nptr); 2034 __try 2035 { 2036 ::new ((void*)__n) __node_type; 2037 __node_alloc_traits::construct(_M_node_allocator(), 2038 __n->_M_valptr(), 2039 std::forward<_Args>(__args)...); 2040 return __n; 2041 } 2042 __catch(...) 2043 { 2044 __node_alloc_traits::deallocate(_M_node_allocator(), __nptr, 1); 2045 __throw_exception_again; 2046 } 2047 } 2048 2049 template<typename _NodeAlloc> 2050 void 2051 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node(__node_type* __n) 2052 { 2053 __node_alloc_traits::destroy(_M_node_allocator(), __n->_M_valptr()); 2054 _M_deallocate_node_ptr(__n); 2055 } 2056 2057 template<typename _NodeAlloc> 2058 void 2059 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node_ptr(__node_type* __n) 2060 { 2061 typedef typename __node_alloc_traits::pointer _Ptr; 2062 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__n); 2063 __n->~__node_type(); 2064 __node_alloc_traits::deallocate(_M_node_allocator(), __ptr, 1); 2065 } 2066 2067 template<typename _NodeAlloc> 2068 void 2069 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_nodes(__node_type* __n) 2070 { 2071 while (__n) 2072 { 2073 __node_type* __tmp = __n; 2074 __n = __n->_M_next(); 2075 _M_deallocate_node(__tmp); 2076 } 2077 } 2078 2079 template<typename _NodeAlloc> 2080 typename _Hashtable_alloc<_NodeAlloc>::__bucket_type* 2081 _Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets(std::size_t __bkt_count) 2082 { 2083 __bucket_alloc_type __alloc(_M_node_allocator()); 2084 2085 auto __ptr = __bucket_alloc_traits::allocate(__alloc, __bkt_count); 2086 __bucket_type* __p = std::__to_address(__ptr); 2087 __builtin_memset(__p, 0, __bkt_count * sizeof(__bucket_type)); 2088 return __p; 2089 } 2090 2091 template<typename _NodeAlloc> 2092 void 2093 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_buckets(__bucket_type* __bkts, 2094 std::size_t __bkt_count) 2095 { 2096 typedef typename __bucket_alloc_traits::pointer _Ptr; 2097 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__bkts); 2098 __bucket_alloc_type __alloc(_M_node_allocator()); 2099 __bucket_alloc_traits::deallocate(__alloc, __ptr, __bkt_count); 2100 } 2101 2102 //@} hashtable-detail 2103 } // namespace __detail 2104 _GLIBCXX_END_NAMESPACE_VERSION 2105 } // namespace std 2106 2107 #endif // _HASHTABLE_POLICY_H 2108