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/usr/include/c++/13/bits/hashtable_policy.h
$ cat -n /usr/include/c++/13/bits/hashtable_policy.h 1 // Internal policy header for unordered_set and unordered_map -*- C++ -*- 2 3 // Copyright (C) 2010-2023 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 <bits/functional_hash.h> // for __is_fast_hash 36 #include <bits/stl_algobase.h> // for std::min, std::is_permutation. 37 #include <bits/stl_pair.h> // for std::pair 38 #include <ext/aligned_buffer.h> // for __gnu_cxx::__aligned_buffer 39 #include <ext/alloc_traits.h> // for std::__alloc_rebind 40 #include <ext/numeric_traits.h> // for __gnu_cxx::__int_traits 41 42 namespace std _GLIBCXX_VISIBILITY(default) 43 { 44 _GLIBCXX_BEGIN_NAMESPACE_VERSION 45 /// @cond undocumented 46 47 template<typename _Key, typename _Value, typename _Alloc, 48 typename _ExtractKey, typename _Equal, 49 typename _Hash, typename _RangeHash, typename _Unused, 50 typename _RehashPolicy, typename _Traits> 51 class _Hashtable; 52 53 namespace __detail 54 { 55 /** 56 * @defgroup hashtable-detail Base and Implementation Classes 57 * @ingroup unordered_associative_containers 58 * @{ 59 */ 60 template<typename _Key, typename _Value, typename _ExtractKey, 61 typename _Equal, typename _Hash, typename _RangeHash, 62 typename _Unused, typename _Traits> 63 struct _Hashtable_base; 64 65 // Helper function: return distance(first, last) for forward 66 // iterators, or 0/1 for input iterators. 67 template<typename _Iterator> 68 inline typename std::iterator_traits<_Iterator>::difference_type 69 __distance_fw(_Iterator __first, _Iterator __last, 70 std::input_iterator_tag) 71 { return __first != __last ? 1 : 0; } 72 73 template<typename _Iterator> 74 inline typename std::iterator_traits<_Iterator>::difference_type 75 __distance_fw(_Iterator __first, _Iterator __last, 76 std::forward_iterator_tag) 77 { return std::distance(__first, __last); } 78 79 template<typename _Iterator> 80 inline typename std::iterator_traits<_Iterator>::difference_type 81 __distance_fw(_Iterator __first, _Iterator __last) 82 { return __distance_fw(__first, __last, 83 std::__iterator_category(__first)); } 84 85 struct _Identity 86 { 87 template<typename _Tp> 88 _Tp&& 89 operator()(_Tp&& __x) const noexcept 90 { return std::forward<_Tp>(__x); } 91 }; 92 93 struct _Select1st 94 { 95 template<typename _Pair> 96 struct __1st_type; 97 98 template<typename _Tp, typename _Up> 99 struct __1st_type<pair<_Tp, _Up>> 100 { using type = _Tp; }; 101 102 template<typename _Tp, typename _Up> 103 struct __1st_type<const pair<_Tp, _Up>> 104 { using type = const _Tp; }; 105 106 template<typename _Pair> 107 struct __1st_type<_Pair&> 108 { using type = typename __1st_type<_Pair>::type&; }; 109 110 template<typename _Tp> 111 typename __1st_type<_Tp>::type&& 112 operator()(_Tp&& __x) const noexcept 113 { return std::forward<_Tp>(__x).first; } 114 }; 115 116 template<typename _ExKey, typename _Value> 117 struct _ConvertToValueType; 118 119 template<typename _Value> 120 struct _ConvertToValueType<_Identity, _Value> 121 { 122 template<typename _Kt> 123 constexpr _Kt&& 124 operator()(_Kt&& __k) const noexcept 125 { return std::forward<_Kt>(__k); } 126 }; 127 128 template<typename _Value> 129 struct _ConvertToValueType<_Select1st, _Value> 130 { 131 constexpr _Value&& 132 operator()(_Value&& __x) const noexcept 133 { return std::move(__x); } 134 135 constexpr const _Value& 136 operator()(const _Value& __x) const noexcept 137 { return __x; } 138 139 template<typename _Kt, typename _Val> 140 constexpr std::pair<_Kt, _Val>&& 141 operator()(std::pair<_Kt, _Val>&& __x) const noexcept 142 { return std::move(__x); } 143 144 template<typename _Kt, typename _Val> 145 constexpr const std::pair<_Kt, _Val>& 146 operator()(const std::pair<_Kt, _Val>& __x) const noexcept 147 { return __x; } 148 }; 149 150 template<typename _ExKey> 151 struct _NodeBuilder; 152 153 template<> 154 struct _NodeBuilder<_Select1st> 155 { 156 template<typename _Kt, typename _Arg, typename _NodeGenerator> 157 static auto 158 _S_build(_Kt&& __k, _Arg&& __arg, const _NodeGenerator& __node_gen) 159 -> typename _NodeGenerator::__node_type* 160 { 161 return __node_gen(std::forward<_Kt>(__k), 162 std::forward<_Arg>(__arg).second); 163 } 164 }; 165 166 template<> 167 struct _NodeBuilder<_Identity> 168 { 169 template<typename _Kt, typename _Arg, typename _NodeGenerator> 170 static auto 171 _S_build(_Kt&& __k, _Arg&&, const _NodeGenerator& __node_gen) 172 -> typename _NodeGenerator::__node_type* 173 { return __node_gen(std::forward<_Kt>(__k)); } 174 }; 175 176 template<typename _NodeAlloc> 177 struct _Hashtable_alloc; 178 179 // Functor recycling a pool of nodes and using allocation once the pool is 180 // empty. 181 template<typename _NodeAlloc> 182 struct _ReuseOrAllocNode 183 { 184 private: 185 using __node_alloc_type = _NodeAlloc; 186 using __hashtable_alloc = _Hashtable_alloc<__node_alloc_type>; 187 using __node_alloc_traits = 188 typename __hashtable_alloc::__node_alloc_traits; 189 190 public: 191 using __node_type = typename __hashtable_alloc::__node_type; 192 193 _ReuseOrAllocNode(__node_type* __nodes, __hashtable_alloc& __h) 194 : _M_nodes(__nodes), _M_h(__h) { } 195 _ReuseOrAllocNode(const _ReuseOrAllocNode&) = delete; 196 197 ~_ReuseOrAllocNode() 198 { _M_h._M_deallocate_nodes(_M_nodes); } 199 200 template<typename... _Args> 201 __node_type* 202 operator()(_Args&&... __args) const 203 { 204 if (_M_nodes) 205 { 206 __node_type* __node = _M_nodes; 207 _M_nodes = _M_nodes->_M_next(); 208 __node->_M_nxt = nullptr; 209 auto& __a = _M_h._M_node_allocator(); 210 __node_alloc_traits::destroy(__a, __node->_M_valptr()); 211 __try 212 { 213 __node_alloc_traits::construct(__a, __node->_M_valptr(), 214 std::forward<_Args>(__args)...); 215 } 216 __catch(...) 217 { 218 _M_h._M_deallocate_node_ptr(__node); 219 __throw_exception_again; 220 } 221 return __node; 222 } 223 return _M_h._M_allocate_node(std::forward<_Args>(__args)...); 224 } 225 226 private: 227 mutable __node_type* _M_nodes; 228 __hashtable_alloc& _M_h; 229 }; 230 231 // Functor similar to the previous one but without any pool of nodes to 232 // recycle. 233 template<typename _NodeAlloc> 234 struct _AllocNode 235 { 236 private: 237 using __hashtable_alloc = _Hashtable_alloc<_NodeAlloc>; 238 239 public: 240 using __node_type = typename __hashtable_alloc::__node_type; 241 242 _AllocNode(__hashtable_alloc& __h) 243 : _M_h(__h) { } 244 245 template<typename... _Args> 246 __node_type* 247 operator()(_Args&&... __args) const 248 { return _M_h._M_allocate_node(std::forward<_Args>(__args)...); } 249 250 private: 251 __hashtable_alloc& _M_h; 252 }; 253 254 // Auxiliary types used for all instantiations of _Hashtable nodes 255 // and iterators. 256 257 /** 258 * struct _Hashtable_traits 259 * 260 * Important traits for hash tables. 261 * 262 * @tparam _Cache_hash_code Boolean value. True if the value of 263 * the hash function is stored along with the value. This is a 264 * time-space tradeoff. Storing it may improve lookup speed by 265 * reducing the number of times we need to call the _Hash or _Equal 266 * functors. 267 * 268 * @tparam _Constant_iterators Boolean value. True if iterator and 269 * const_iterator are both constant iterator types. This is true 270 * for unordered_set and unordered_multiset, false for 271 * unordered_map and unordered_multimap. 272 * 273 * @tparam _Unique_keys Boolean value. True if the return value 274 * of _Hashtable::count(k) is always at most one, false if it may 275 * be an arbitrary number. This is true for unordered_set and 276 * unordered_map, false for unordered_multiset and 277 * unordered_multimap. 278 */ 279 template<bool _Cache_hash_code, bool _Constant_iterators, bool _Unique_keys> 280 struct _Hashtable_traits 281 { 282 using __hash_cached = __bool_constant<_Cache_hash_code>; 283 using __constant_iterators = __bool_constant<_Constant_iterators>; 284 using __unique_keys = __bool_constant<_Unique_keys>; 285 }; 286 287 /** 288 * struct _Hashtable_hash_traits 289 * 290 * Important traits for hash tables depending on associated hasher. 291 * 292 */ 293 template<typename _Hash> 294 struct _Hashtable_hash_traits 295 { 296 static constexpr std::size_t 297 __small_size_threshold() noexcept 298 { return std::__is_fast_hash<_Hash>::value ? 0 : 20; } 299 }; 300 301 /** 302 * struct _Hash_node_base 303 * 304 * Nodes, used to wrap elements stored in the hash table. A policy 305 * template parameter of class template _Hashtable controls whether 306 * nodes also store a hash code. In some cases (e.g. strings) this 307 * may be a performance win. 308 */ 309 struct _Hash_node_base 310 { 311 _Hash_node_base* _M_nxt; 312 313 _Hash_node_base() noexcept : _M_nxt() { } 314 315 _Hash_node_base(_Hash_node_base* __next) noexcept : _M_nxt(__next) { } 316 }; 317 318 /** 319 * struct _Hash_node_value_base 320 * 321 * Node type with the value to store. 322 */ 323 template<typename _Value> 324 struct _Hash_node_value_base 325 { 326 typedef _Value value_type; 327 328 __gnu_cxx::__aligned_buffer<_Value> _M_storage; 329 330 [[__gnu__::__always_inline__]] 331 _Value* 332 _M_valptr() noexcept 333 { return _M_storage._M_ptr(); } 334 335 [[__gnu__::__always_inline__]] 336 const _Value* 337 _M_valptr() const noexcept 338 { return _M_storage._M_ptr(); } 339 340 [[__gnu__::__always_inline__]] 341 _Value& 342 _M_v() noexcept 343 { return *_M_valptr(); } 344 345 [[__gnu__::__always_inline__]] 346 const _Value& 347 _M_v() const noexcept 348 { return *_M_valptr(); } 349 }; 350 351 /** 352 * Primary template struct _Hash_node_code_cache. 353 */ 354 template<bool _Cache_hash_code> 355 struct _Hash_node_code_cache 356 { }; 357 358 /** 359 * Specialization for node with cache, struct _Hash_node_code_cache. 360 */ 361 template<> 362 struct _Hash_node_code_cache<true> 363 { std::size_t _M_hash_code; }; 364 365 template<typename _Value, bool _Cache_hash_code> 366 struct _Hash_node_value 367 : _Hash_node_value_base<_Value> 368 , _Hash_node_code_cache<_Cache_hash_code> 369 { }; 370 371 /** 372 * Primary template struct _Hash_node. 373 */ 374 template<typename _Value, bool _Cache_hash_code> 375 struct _Hash_node 376 : _Hash_node_base 377 , _Hash_node_value<_Value, _Cache_hash_code> 378 { 379 _Hash_node* 380 _M_next() const noexcept 381 { return static_cast<_Hash_node*>(this->_M_nxt); } 382 }; 383 384 /// Base class for node iterators. 385 template<typename _Value, bool _Cache_hash_code> 386 struct _Node_iterator_base 387 { 388 using __node_type = _Hash_node<_Value, _Cache_hash_code>; 389 390 __node_type* _M_cur; 391 392 _Node_iterator_base() : _M_cur(nullptr) { } 393 _Node_iterator_base(__node_type* __p) noexcept 394 : _M_cur(__p) { } 395 396 void 397 _M_incr() noexcept 398 { _M_cur = _M_cur->_M_next(); } 399 400 friend bool 401 operator==(const _Node_iterator_base& __x, const _Node_iterator_base& __y) 402 noexcept 403 { return __x._M_cur == __y._M_cur; } 404 405 #if __cpp_impl_three_way_comparison < 201907L 406 friend bool 407 operator!=(const _Node_iterator_base& __x, const _Node_iterator_base& __y) 408 noexcept 409 { return __x._M_cur != __y._M_cur; } 410 #endif 411 }; 412 413 /// Node iterators, used to iterate through all the hashtable. 414 template<typename _Value, bool __constant_iterators, bool __cache> 415 struct _Node_iterator 416 : public _Node_iterator_base<_Value, __cache> 417 { 418 private: 419 using __base_type = _Node_iterator_base<_Value, __cache>; 420 using __node_type = typename __base_type::__node_type; 421 422 public: 423 using value_type = _Value; 424 using difference_type = std::ptrdiff_t; 425 using iterator_category = std::forward_iterator_tag; 426 427 using pointer = __conditional_t<__constant_iterators, 428 const value_type*, value_type*>; 429 430 using reference = __conditional_t<__constant_iterators, 431 const value_type&, value_type&>; 432 433 _Node_iterator() = default; 434 435 explicit 436 _Node_iterator(__node_type* __p) noexcept 437 : __base_type(__p) { } 438 439 reference 440 operator*() const noexcept 441 { return this->_M_cur->_M_v(); } 442 443 pointer 444 operator->() const noexcept 445 { return this->_M_cur->_M_valptr(); } 446 447 _Node_iterator& 448 operator++() noexcept 449 { 450 this->_M_incr(); 451 return *this; 452 } 453 454 _Node_iterator 455 operator++(int) noexcept 456 { 457 _Node_iterator __tmp(*this); 458 this->_M_incr(); 459 return __tmp; 460 } 461 }; 462 463 /// Node const_iterators, used to iterate through all the hashtable. 464 template<typename _Value, bool __constant_iterators, bool __cache> 465 struct _Node_const_iterator 466 : public _Node_iterator_base<_Value, __cache> 467 { 468 private: 469 using __base_type = _Node_iterator_base<_Value, __cache>; 470 using __node_type = typename __base_type::__node_type; 471 472 public: 473 typedef _Value value_type; 474 typedef std::ptrdiff_t difference_type; 475 typedef std::forward_iterator_tag iterator_category; 476 477 typedef const value_type* pointer; 478 typedef const value_type& reference; 479 480 _Node_const_iterator() = default; 481 482 explicit 483 _Node_const_iterator(__node_type* __p) noexcept 484 : __base_type(__p) { } 485 486 _Node_const_iterator(const _Node_iterator<_Value, __constant_iterators, 487 __cache>& __x) noexcept 488 : __base_type(__x._M_cur) { } 489 490 reference 491 operator*() const noexcept 492 { return this->_M_cur->_M_v(); } 493 494 pointer 495 operator->() const noexcept 496 { return this->_M_cur->_M_valptr(); } 497 498 _Node_const_iterator& 499 operator++() noexcept 500 { 501 this->_M_incr(); 502 return *this; 503 } 504 505 _Node_const_iterator 506 operator++(int) noexcept 507 { 508 _Node_const_iterator __tmp(*this); 509 this->_M_incr(); 510 return __tmp; 511 } 512 }; 513 514 // Many of class template _Hashtable's template parameters are policy 515 // classes. These are defaults for the policies. 516 517 /// Default range hashing function: use division to fold a large number 518 /// into the range [0, N). 519 struct _Mod_range_hashing 520 { 521 typedef std::size_t first_argument_type; 522 typedef std::size_t second_argument_type; 523 typedef std::size_t result_type; 524 525 result_type 526 operator()(first_argument_type __num, 527 second_argument_type __den) const noexcept 528 { return __num % __den; } 529 }; 530 531 /// Default ranged hash function H. In principle it should be a 532 /// function object composed from objects of type H1 and H2 such that 533 /// h(k, N) = h2(h1(k), N), but that would mean making extra copies of 534 /// h1 and h2. So instead we'll just use a tag to tell class template 535 /// hashtable to do that composition. 536 struct _Default_ranged_hash { }; 537 538 /// Default value for rehash policy. Bucket size is (usually) the 539 /// smallest prime that keeps the load factor small enough. 540 struct _Prime_rehash_policy 541 { 542 using __has_load_factor = true_type; 543 544 _Prime_rehash_policy(float __z = 1.0) noexcept 545 : _M_max_load_factor(__z), _M_next_resize(0) { } 546 547 float 548 max_load_factor() const noexcept 549 { return _M_max_load_factor; } 550 551 // Return a bucket size no smaller than n. 552 std::size_t 553 _M_next_bkt(std::size_t __n) const; 554 555 // Return a bucket count appropriate for n elements 556 std::size_t 557 _M_bkt_for_elements(std::size_t __n) const 558 { return __builtin_ceil(__n / (double)_M_max_load_factor); } 559 560 // __n_bkt is current bucket count, __n_elt is current element count, 561 // and __n_ins is number of elements to be inserted. Do we need to 562 // increase bucket count? If so, return make_pair(true, n), where n 563 // is the new bucket count. If not, return make_pair(false, 0). 564 std::pair<bool, std::size_t> 565 _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, 566 std::size_t __n_ins) const; 567 568 typedef std::size_t _State; 569 570 _State 571 _M_state() const 572 { return _M_next_resize; } 573 574 void 575 _M_reset() noexcept 576 { _M_next_resize = 0; } 577 578 void 579 _M_reset(_State __state) 580 { _M_next_resize = __state; } 581 582 static const std::size_t _S_growth_factor = 2; 583 584 float _M_max_load_factor; 585 mutable std::size_t _M_next_resize; 586 }; 587 588 /// Range hashing function assuming that second arg is a power of 2. 589 struct _Mask_range_hashing 590 { 591 typedef std::size_t first_argument_type; 592 typedef std::size_t second_argument_type; 593 typedef std::size_t result_type; 594 595 result_type 596 operator()(first_argument_type __num, 597 second_argument_type __den) const noexcept 598 { return __num & (__den - 1); } 599 }; 600 601 /// Compute closest power of 2 not less than __n 602 inline std::size_t 603 __clp2(std::size_t __n) noexcept 604 { 605 using __gnu_cxx::__int_traits; 606 // Equivalent to return __n ? std::bit_ceil(__n) : 0; 607 if (__n < 2) 608 return __n; 609 const unsigned __lz = sizeof(size_t) > sizeof(long) 610 ? __builtin_clzll(__n - 1ull) 611 : __builtin_clzl(__n - 1ul); 612 // Doing two shifts avoids undefined behaviour when __lz == 0. 613 return (size_t(1) << (__int_traits<size_t>::__digits - __lz - 1)) << 1; 614 } 615 616 /// Rehash policy providing power of 2 bucket numbers. Avoids modulo 617 /// operations. 618 struct _Power2_rehash_policy 619 { 620 using __has_load_factor = true_type; 621 622 _Power2_rehash_policy(float __z = 1.0) noexcept 623 : _M_max_load_factor(__z), _M_next_resize(0) { } 624 625 float 626 max_load_factor() const noexcept 627 { return _M_max_load_factor; } 628 629 // Return a bucket size no smaller than n (as long as n is not above the 630 // highest power of 2). 631 std::size_t 632 _M_next_bkt(std::size_t __n) noexcept 633 { 634 if (__n == 0) 635 // Special case on container 1st initialization with 0 bucket count 636 // hint. We keep _M_next_resize to 0 to make sure that next time we 637 // want to add an element allocation will take place. 638 return 1; 639 640 const auto __max_width = std::min<size_t>(sizeof(size_t), 8); 641 const auto __max_bkt = size_t(1) << (__max_width * __CHAR_BIT__ - 1); 642 std::size_t __res = __clp2(__n); 643 644 if (__res == 0) 645 __res = __max_bkt; 646 else if (__res == 1) 647 // If __res is 1 we force it to 2 to make sure there will be an 648 // allocation so that nothing need to be stored in the initial 649 // single bucket 650 __res = 2; 651 652 if (__res == __max_bkt) 653 // Set next resize to the max value so that we never try to rehash again 654 // as we already reach the biggest possible bucket number. 655 // Note that it might result in max_load_factor not being respected. 656 _M_next_resize = size_t(-1); 657 else 658 _M_next_resize 659 = __builtin_floor(__res * (double)_M_max_load_factor); 660 661 return __res; 662 } 663 664 // Return a bucket count appropriate for n elements 665 std::size_t 666 _M_bkt_for_elements(std::size_t __n) const noexcept 667 { return __builtin_ceil(__n / (double)_M_max_load_factor); } 668 669 // __n_bkt is current bucket count, __n_elt is current element count, 670 // and __n_ins is number of elements to be inserted. Do we need to 671 // increase bucket count? If so, return make_pair(true, n), where n 672 // is the new bucket count. If not, return make_pair(false, 0). 673 std::pair<bool, std::size_t> 674 _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt, 675 std::size_t __n_ins) noexcept 676 { 677 if (__n_elt + __n_ins > _M_next_resize) 678 { 679 // If _M_next_resize is 0 it means that we have nothing allocated so 680 // far and that we start inserting elements. In this case we start 681 // with an initial bucket size of 11. 682 double __min_bkts 683 = std::max<std::size_t>(__n_elt + __n_ins, _M_next_resize ? 0 : 11) 684 / (double)_M_max_load_factor; 685 if (__min_bkts >= __n_bkt) 686 return { true, 687 _M_next_bkt(std::max<std::size_t>(__builtin_floor(__min_bkts) + 1, 688 __n_bkt * _S_growth_factor)) }; 689 690 _M_next_resize 691 = __builtin_floor(__n_bkt * (double)_M_max_load_factor); 692 return { false, 0 }; 693 } 694 else 695 return { false, 0 }; 696 } 697 698 typedef std::size_t _State; 699 700 _State 701 _M_state() const noexcept 702 { return _M_next_resize; } 703 704 void 705 _M_reset() noexcept 706 { _M_next_resize = 0; } 707 708 void 709 _M_reset(_State __state) noexcept 710 { _M_next_resize = __state; } 711 712 static const std::size_t _S_growth_factor = 2; 713 714 float _M_max_load_factor; 715 std::size_t _M_next_resize; 716 }; 717 718 // Base classes for std::_Hashtable. We define these base classes 719 // because in some cases we want to do different things depending on 720 // the value of a policy class. In some cases the policy class 721 // affects which member functions and nested typedefs are defined; 722 // we handle that by specializing base class templates. Several of 723 // the base class templates need to access other members of class 724 // template _Hashtable, so we use a variant of the "Curiously 725 // Recurring Template Pattern" (CRTP) technique. 726 727 /** 728 * Primary class template _Map_base. 729 * 730 * If the hashtable has a value type of the form pair<const T1, T2> and 731 * a key extraction policy (_ExtractKey) that returns the first part 732 * of the pair, the hashtable gets a mapped_type typedef. If it 733 * satisfies those criteria and also has unique keys, then it also 734 * gets an operator[]. 735 */ 736 template<typename _Key, typename _Value, typename _Alloc, 737 typename _ExtractKey, typename _Equal, 738 typename _Hash, typename _RangeHash, typename _Unused, 739 typename _RehashPolicy, typename _Traits, 740 bool _Unique_keys = _Traits::__unique_keys::value> 741 struct _Map_base { }; 742 743 /// Partial specialization, __unique_keys set to false, std::pair value type. 744 template<typename _Key, typename _Val, typename _Alloc, typename _Equal, 745 typename _Hash, typename _RangeHash, typename _Unused, 746 typename _RehashPolicy, typename _Traits> 747 struct _Map_base<_Key, pair<const _Key, _Val>, _Alloc, _Select1st, _Equal, 748 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, false> 749 { 750 using mapped_type = _Val; 751 }; 752 753 /// Partial specialization, __unique_keys set to true. 754 template<typename _Key, typename _Val, typename _Alloc, typename _Equal, 755 typename _Hash, typename _RangeHash, typename _Unused, 756 typename _RehashPolicy, typename _Traits> 757 struct _Map_base<_Key, pair<const _Key, _Val>, _Alloc, _Select1st, _Equal, 758 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, true> 759 { 760 private: 761 using __hashtable_base = _Hashtable_base<_Key, pair<const _Key, _Val>, 762 _Select1st, _Equal, _Hash, 763 _RangeHash, _Unused, 764 _Traits>; 765 766 using __hashtable = _Hashtable<_Key, pair<const _Key, _Val>, _Alloc, 767 _Select1st, _Equal, _Hash, _RangeHash, 768 _Unused, _RehashPolicy, _Traits>; 769 770 using __hash_code = typename __hashtable_base::__hash_code; 771 772 public: 773 using key_type = typename __hashtable_base::key_type; 774 using mapped_type = _Val; 775 776 mapped_type& 777 operator[](const key_type& __k); 778 779 mapped_type& 780 operator[](key_type&& __k); 781 782 // _GLIBCXX_RESOLVE_LIB_DEFECTS 783 // DR 761. unordered_map needs an at() member function. 784 mapped_type& 785 at(const key_type& __k) 786 { 787 auto __ite = static_cast<__hashtable*>(this)->find(__k); 788 if (!__ite._M_cur) 789 __throw_out_of_range(__N("unordered_map::at")); 790 return __ite->second; 791 } 792 793 const mapped_type& 794 at(const key_type& __k) const 795 { 796 auto __ite = static_cast<const __hashtable*>(this)->find(__k); 797 if (!__ite._M_cur) 798 __throw_out_of_range(__N("unordered_map::at")); 799 return __ite->second; 800 } 801 }; 802 803 template<typename _Key, typename _Val, typename _Alloc, typename _Equal, 804 typename _Hash, typename _RangeHash, typename _Unused, 805 typename _RehashPolicy, typename _Traits> 806 auto 807 _Map_base<_Key, pair<const _Key, _Val>, _Alloc, _Select1st, _Equal, 808 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, true>:: 809 operator[](const key_type& __k) 810 -> mapped_type& 811 { 812 __hashtable* __h = static_cast<__hashtable*>(this); 813 __hash_code __code = __h->_M_hash_code(__k); 814 std::size_t __bkt = __h->_M_bucket_index(__code); 815 if (auto __node = __h->_M_find_node(__bkt, __k, __code)) 816 return __node->_M_v().second; 817 818 typename __hashtable::_Scoped_node __node { 819 __h, 820 std::piecewise_construct, 821 std::tuple<const key_type&>(__k), 822 std::tuple<>() 823 }; 824 auto __pos 825 = __h->_M_insert_unique_node(__bkt, __code, __node._M_node); 826 __node._M_node = nullptr; 827 return __pos->second; 828 } 829 830 template<typename _Key, typename _Val, typename _Alloc, typename _Equal, 831 typename _Hash, typename _RangeHash, typename _Unused, 832 typename _RehashPolicy, typename _Traits> 833 auto 834 _Map_base<_Key, pair<const _Key, _Val>, _Alloc, _Select1st, _Equal, 835 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, true>:: 836 operator[](key_type&& __k) 837 -> mapped_type& 838 { 839 __hashtable* __h = static_cast<__hashtable*>(this); 840 __hash_code __code = __h->_M_hash_code(__k); 841 std::size_t __bkt = __h->_M_bucket_index(__code); 842 if (auto __node = __h->_M_find_node(__bkt, __k, __code)) 843 return __node->_M_v().second; 844 845 typename __hashtable::_Scoped_node __node { 846 __h, 847 std::piecewise_construct, 848 std::forward_as_tuple(std::move(__k)), 849 std::tuple<>() 850 }; 851 auto __pos 852 = __h->_M_insert_unique_node(__bkt, __code, __node._M_node); 853 __node._M_node = nullptr; 854 return __pos->second; 855 } 856 857 // Partial specialization for unordered_map<const T, U>, see PR 104174. 858 template<typename _Key, typename _Val, typename _Alloc, typename _Equal, 859 typename _Hash, typename _RangeHash, typename _Unused, 860 typename _RehashPolicy, typename _Traits, bool __uniq> 861 struct _Map_base<const _Key, pair<const _Key, _Val>, 862 _Alloc, _Select1st, _Equal, _Hash, 863 _RangeHash, _Unused, _RehashPolicy, _Traits, __uniq> 864 : _Map_base<_Key, pair<const _Key, _Val>, _Alloc, _Select1st, _Equal, _Hash, 865 _RangeHash, _Unused, _RehashPolicy, _Traits, __uniq> 866 { }; 867 868 /** 869 * Primary class template _Insert_base. 870 * 871 * Defines @c insert member functions appropriate to all _Hashtables. 872 */ 873 template<typename _Key, typename _Value, typename _Alloc, 874 typename _ExtractKey, typename _Equal, 875 typename _Hash, typename _RangeHash, typename _Unused, 876 typename _RehashPolicy, typename _Traits> 877 struct _Insert_base 878 { 879 protected: 880 using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey, 881 _Equal, _Hash, _RangeHash, 882 _Unused, _Traits>; 883 884 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 885 _Hash, _RangeHash, 886 _Unused, _RehashPolicy, _Traits>; 887 888 using __hash_cached = typename _Traits::__hash_cached; 889 using __constant_iterators = typename _Traits::__constant_iterators; 890 891 using __hashtable_alloc = _Hashtable_alloc< 892 __alloc_rebind<_Alloc, _Hash_node<_Value, 893 __hash_cached::value>>>; 894 895 using value_type = typename __hashtable_base::value_type; 896 using size_type = typename __hashtable_base::size_type; 897 898 using __unique_keys = typename _Traits::__unique_keys; 899 using __node_alloc_type = typename __hashtable_alloc::__node_alloc_type; 900 using __node_gen_type = _AllocNode<__node_alloc_type>; 901 902 __hashtable& 903 _M_conjure_hashtable() 904 { return *(static_cast<__hashtable*>(this)); } 905 906 template<typename _InputIterator, typename _NodeGetter> 907 void 908 _M_insert_range(_InputIterator __first, _InputIterator __last, 909 const _NodeGetter&, true_type __uks); 910 911 template<typename _InputIterator, typename _NodeGetter> 912 void 913 _M_insert_range(_InputIterator __first, _InputIterator __last, 914 const _NodeGetter&, false_type __uks); 915 916 public: 917 using iterator = _Node_iterator<_Value, __constant_iterators::value, 918 __hash_cached::value>; 919 920 using const_iterator = _Node_const_iterator<_Value, 921 __constant_iterators::value, 922 __hash_cached::value>; 923 924 using __ireturn_type = __conditional_t<__unique_keys::value, 925 std::pair<iterator, bool>, 926 iterator>; 927 928 __ireturn_type 929 insert(const value_type& __v) 930 { 931 __hashtable& __h = _M_conjure_hashtable(); 932 __node_gen_type __node_gen(__h); 933 return __h._M_insert(__v, __node_gen, __unique_keys{}); 934 } 935 936 iterator 937 insert(const_iterator __hint, const value_type& __v) 938 { 939 __hashtable& __h = _M_conjure_hashtable(); 940 __node_gen_type __node_gen(__h); 941 return __h._M_insert(__hint, __v, __node_gen, __unique_keys{}); 942 } 943 944 template<typename _KType, typename... _Args> 945 std::pair<iterator, bool> 946 try_emplace(const_iterator, _KType&& __k, _Args&&... __args) 947 { 948 __hashtable& __h = _M_conjure_hashtable(); 949 auto __code = __h._M_hash_code(__k); 950 std::size_t __bkt = __h._M_bucket_index(__code); 951 if (auto __node = __h._M_find_node(__bkt, __k, __code)) 952 return { iterator(__node), false }; 953 954 typename __hashtable::_Scoped_node __node { 955 &__h, 956 std::piecewise_construct, 957 std::forward_as_tuple(std::forward<_KType>(__k)), 958 std::forward_as_tuple(std::forward<_Args>(__args)...) 959 }; 960 auto __it 961 = __h._M_insert_unique_node(__bkt, __code, __node._M_node); 962 __node._M_node = nullptr; 963 return { __it, true }; 964 } 965 966 void 967 insert(initializer_list<value_type> __l) 968 { this->insert(__l.begin(), __l.end()); } 969 970 template<typename _InputIterator> 971 void 972 insert(_InputIterator __first, _InputIterator __last) 973 { 974 __hashtable& __h = _M_conjure_hashtable(); 975 __node_gen_type __node_gen(__h); 976 return _M_insert_range(__first, __last, __node_gen, __unique_keys{}); 977 } 978 }; 979 980 template<typename _Key, typename _Value, typename _Alloc, 981 typename _ExtractKey, typename _Equal, 982 typename _Hash, typename _RangeHash, typename _Unused, 983 typename _RehashPolicy, typename _Traits> 984 template<typename _InputIterator, typename _NodeGetter> 985 void 986 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 987 _Hash, _RangeHash, _Unused, 988 _RehashPolicy, _Traits>:: 989 _M_insert_range(_InputIterator __first, _InputIterator __last, 990 const _NodeGetter& __node_gen, true_type __uks) 991 { 992 __hashtable& __h = _M_conjure_hashtable(); 993 for (; __first != __last; ++__first) 994 __h._M_insert(*__first, __node_gen, __uks); 995 } 996 997 template<typename _Key, typename _Value, typename _Alloc, 998 typename _ExtractKey, typename _Equal, 999 typename _Hash, typename _RangeHash, typename _Unused, 1000 typename _RehashPolicy, typename _Traits> 1001 template<typename _InputIterator, typename _NodeGetter> 1002 void 1003 _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1004 _Hash, _RangeHash, _Unused, 1005 _RehashPolicy, _Traits>:: 1006 _M_insert_range(_InputIterator __first, _InputIterator __last, 1007 const _NodeGetter& __node_gen, false_type __uks) 1008 { 1009 using __rehash_type = typename __hashtable::__rehash_type; 1010 using __rehash_state = typename __hashtable::__rehash_state; 1011 using pair_type = std::pair<bool, std::size_t>; 1012 1013 size_type __n_elt = __detail::__distance_fw(__first, __last); 1014 if (__n_elt == 0) 1015 return; 1016 1017 __hashtable& __h = _M_conjure_hashtable(); 1018 __rehash_type& __rehash = __h._M_rehash_policy; 1019 const __rehash_state& __saved_state = __rehash._M_state(); 1020 pair_type __do_rehash = __rehash._M_need_rehash(__h._M_bucket_count, 1021 __h._M_element_count, 1022 __n_elt); 1023 1024 if (__do_rehash.first) 1025 __h._M_rehash(__do_rehash.second, __saved_state); 1026 1027 for (; __first != __last; ++__first) 1028 __h._M_insert(*__first, __node_gen, __uks); 1029 } 1030 1031 /** 1032 * Primary class template _Insert. 1033 * 1034 * Defines @c insert member functions that depend on _Hashtable policies, 1035 * via partial specializations. 1036 */ 1037 template<typename _Key, typename _Value, typename _Alloc, 1038 typename _ExtractKey, typename _Equal, 1039 typename _Hash, typename _RangeHash, typename _Unused, 1040 typename _RehashPolicy, typename _Traits, 1041 bool _Constant_iterators = _Traits::__constant_iterators::value> 1042 struct _Insert; 1043 1044 /// Specialization. 1045 template<typename _Key, typename _Value, typename _Alloc, 1046 typename _ExtractKey, typename _Equal, 1047 typename _Hash, typename _RangeHash, typename _Unused, 1048 typename _RehashPolicy, typename _Traits> 1049 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1050 _Hash, _RangeHash, _Unused, 1051 _RehashPolicy, _Traits, true> 1052 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1053 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits> 1054 { 1055 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey, 1056 _Equal, _Hash, _RangeHash, _Unused, 1057 _RehashPolicy, _Traits>; 1058 1059 using value_type = typename __base_type::value_type; 1060 using iterator = typename __base_type::iterator; 1061 using const_iterator = typename __base_type::const_iterator; 1062 using __ireturn_type = typename __base_type::__ireturn_type; 1063 1064 using __unique_keys = typename __base_type::__unique_keys; 1065 using __hashtable = typename __base_type::__hashtable; 1066 using __node_gen_type = typename __base_type::__node_gen_type; 1067 1068 using __base_type::insert; 1069 1070 __ireturn_type 1071 insert(value_type&& __v) 1072 { 1073 __hashtable& __h = this->_M_conjure_hashtable(); 1074 __node_gen_type __node_gen(__h); 1075 return __h._M_insert(std::move(__v), __node_gen, __unique_keys{}); 1076 } 1077 1078 iterator 1079 insert(const_iterator __hint, value_type&& __v) 1080 { 1081 __hashtable& __h = this->_M_conjure_hashtable(); 1082 __node_gen_type __node_gen(__h); 1083 return __h._M_insert(__hint, std::move(__v), __node_gen, 1084 __unique_keys{}); 1085 } 1086 }; 1087 1088 /// Specialization. 1089 template<typename _Key, typename _Value, typename _Alloc, 1090 typename _ExtractKey, typename _Equal, 1091 typename _Hash, typename _RangeHash, typename _Unused, 1092 typename _RehashPolicy, typename _Traits> 1093 struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1094 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, false> 1095 : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1096 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits> 1097 { 1098 using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey, 1099 _Equal, _Hash, _RangeHash, _Unused, 1100 _RehashPolicy, _Traits>; 1101 using value_type = typename __base_type::value_type; 1102 using iterator = typename __base_type::iterator; 1103 using const_iterator = typename __base_type::const_iterator; 1104 1105 using __unique_keys = typename __base_type::__unique_keys; 1106 using __hashtable = typename __base_type::__hashtable; 1107 using __ireturn_type = typename __base_type::__ireturn_type; 1108 1109 using __base_type::insert; 1110 1111 template<typename _Pair> 1112 using __is_cons = std::is_constructible<value_type, _Pair&&>; 1113 1114 template<typename _Pair> 1115 using _IFcons = std::enable_if<__is_cons<_Pair>::value>; 1116 1117 template<typename _Pair> 1118 using _IFconsp = typename _IFcons<_Pair>::type; 1119 1120 template<typename _Pair, typename = _IFconsp<_Pair>> 1121 __ireturn_type 1122 insert(_Pair&& __v) 1123 { 1124 __hashtable& __h = this->_M_conjure_hashtable(); 1125 return __h._M_emplace(__unique_keys{}, std::forward<_Pair>(__v)); 1126 } 1127 1128 template<typename _Pair, typename = _IFconsp<_Pair>> 1129 iterator 1130 insert(const_iterator __hint, _Pair&& __v) 1131 { 1132 __hashtable& __h = this->_M_conjure_hashtable(); 1133 return __h._M_emplace(__hint, __unique_keys{}, 1134 std::forward<_Pair>(__v)); 1135 } 1136 }; 1137 1138 template<typename _Policy> 1139 using __has_load_factor = typename _Policy::__has_load_factor; 1140 1141 /** 1142 * Primary class template _Rehash_base. 1143 * 1144 * Give hashtable the max_load_factor functions and reserve iff the 1145 * rehash policy supports it. 1146 */ 1147 template<typename _Key, typename _Value, typename _Alloc, 1148 typename _ExtractKey, typename _Equal, 1149 typename _Hash, typename _RangeHash, typename _Unused, 1150 typename _RehashPolicy, typename _Traits, 1151 typename = 1152 __detected_or_t<false_type, __has_load_factor, _RehashPolicy>> 1153 struct _Rehash_base; 1154 1155 /// Specialization when rehash policy doesn't provide load factor management. 1156 template<typename _Key, typename _Value, typename _Alloc, 1157 typename _ExtractKey, typename _Equal, 1158 typename _Hash, typename _RangeHash, typename _Unused, 1159 typename _RehashPolicy, typename _Traits> 1160 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1161 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, 1162 false_type /* Has load factor */> 1163 { 1164 }; 1165 1166 /// Specialization when rehash policy provide load factor management. 1167 template<typename _Key, typename _Value, typename _Alloc, 1168 typename _ExtractKey, typename _Equal, 1169 typename _Hash, typename _RangeHash, typename _Unused, 1170 typename _RehashPolicy, typename _Traits> 1171 struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1172 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, 1173 true_type /* Has load factor */> 1174 { 1175 private: 1176 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, 1177 _Equal, _Hash, _RangeHash, _Unused, 1178 _RehashPolicy, _Traits>; 1179 1180 public: 1181 float 1182 max_load_factor() const noexcept 1183 { 1184 const __hashtable* __this = static_cast<const __hashtable*>(this); 1185 return __this->__rehash_policy().max_load_factor(); 1186 } 1187 1188 void 1189 max_load_factor(float __z) 1190 { 1191 __hashtable* __this = static_cast<__hashtable*>(this); 1192 __this->__rehash_policy(_RehashPolicy(__z)); 1193 } 1194 1195 void 1196 reserve(std::size_t __n) 1197 { 1198 __hashtable* __this = static_cast<__hashtable*>(this); 1199 __this->rehash(__this->__rehash_policy()._M_bkt_for_elements(__n)); 1200 } 1201 }; 1202 1203 /** 1204 * Primary class template _Hashtable_ebo_helper. 1205 * 1206 * Helper class using EBO when it is not forbidden (the type is not 1207 * final) and when it is worth it (the type is empty.) 1208 */ 1209 template<int _Nm, typename _Tp, 1210 bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)> 1211 struct _Hashtable_ebo_helper; 1212 1213 /// Specialization using EBO. 1214 template<int _Nm, typename _Tp> 1215 struct _Hashtable_ebo_helper<_Nm, _Tp, true> 1216 : private _Tp 1217 { 1218 _Hashtable_ebo_helper() noexcept(noexcept(_Tp())) : _Tp() { } 1219 1220 template<typename _OtherTp> 1221 _Hashtable_ebo_helper(_OtherTp&& __tp) 1222 : _Tp(std::forward<_OtherTp>(__tp)) 1223 { } 1224 1225 const _Tp& _M_cget() const { return static_cast<const _Tp&>(*this); } 1226 _Tp& _M_get() { return static_cast<_Tp&>(*this); } 1227 }; 1228 1229 /// Specialization not using EBO. 1230 template<int _Nm, typename _Tp> 1231 struct _Hashtable_ebo_helper<_Nm, _Tp, false> 1232 { 1233 _Hashtable_ebo_helper() = default; 1234 1235 template<typename _OtherTp> 1236 _Hashtable_ebo_helper(_OtherTp&& __tp) 1237 : _M_tp(std::forward<_OtherTp>(__tp)) 1238 { } 1239 1240 const _Tp& _M_cget() const { return _M_tp; } 1241 _Tp& _M_get() { return _M_tp; } 1242 1243 private: 1244 _Tp _M_tp{}; 1245 }; 1246 1247 /** 1248 * Primary class template _Local_iterator_base. 1249 * 1250 * Base class for local iterators, used to iterate within a bucket 1251 * but not between buckets. 1252 */ 1253 template<typename _Key, typename _Value, typename _ExtractKey, 1254 typename _Hash, typename _RangeHash, typename _Unused, 1255 bool __cache_hash_code> 1256 struct _Local_iterator_base; 1257 1258 /** 1259 * Primary class template _Hash_code_base. 1260 * 1261 * Encapsulates two policy issues that aren't quite orthogonal. 1262 * (1) the difference between using a ranged hash function and using 1263 * the combination of a hash function and a range-hashing function. 1264 * In the former case we don't have such things as hash codes, so 1265 * we have a dummy type as placeholder. 1266 * (2) Whether or not we cache hash codes. Caching hash codes is 1267 * meaningless if we have a ranged hash function. 1268 * 1269 * We also put the key extraction objects here, for convenience. 1270 * Each specialization derives from one or more of the template 1271 * parameters to benefit from Ebo. This is important as this type 1272 * is inherited in some cases by the _Local_iterator_base type used 1273 * to implement local_iterator and const_local_iterator. As with 1274 * any iterator type we prefer to make it as small as possible. 1275 */ 1276 template<typename _Key, typename _Value, typename _ExtractKey, 1277 typename _Hash, typename _RangeHash, typename _Unused, 1278 bool __cache_hash_code> 1279 struct _Hash_code_base 1280 : private _Hashtable_ebo_helper<1, _Hash> 1281 { 1282 private: 1283 using __ebo_hash = _Hashtable_ebo_helper<1, _Hash>; 1284 1285 // Gives the local iterator implementation access to _M_bucket_index(). 1286 friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, 1287 _Hash, _RangeHash, _Unused, false>; 1288 1289 public: 1290 typedef _Hash hasher; 1291 1292 hasher 1293 hash_function() const 1294 { return _M_hash(); } 1295 1296 protected: 1297 typedef std::size_t __hash_code; 1298 1299 // We need the default constructor for the local iterators and _Hashtable 1300 // default constructor. 1301 _Hash_code_base() = default; 1302 1303 _Hash_code_base(const _Hash& __hash) : __ebo_hash(__hash) { } 1304 1305 __hash_code 1306 _M_hash_code(const _Key& __k) const 1307 { 1308 static_assert(__is_invocable<const _Hash&, const _Key&>{}, 1309 "hash function must be invocable with an argument of key type"); 1310 return _M_hash()(__k); 1311 } 1312 1313 template<typename _Kt> 1314 __hash_code 1315 _M_hash_code_tr(const _Kt& __k) const 1316 { 1317 static_assert(__is_invocable<const _Hash&, const _Kt&>{}, 1318 "hash function must be invocable with an argument of key type"); 1319 return _M_hash()(__k); 1320 } 1321 1322 __hash_code 1323 _M_hash_code(const _Hash_node_value<_Value, false>& __n) const 1324 { return _M_hash_code(_ExtractKey{}(__n._M_v())); } 1325 1326 __hash_code 1327 _M_hash_code(const _Hash_node_value<_Value, true>& __n) const 1328 { return __n._M_hash_code; } 1329 1330 std::size_t 1331 _M_bucket_index(__hash_code __c, std::size_t __bkt_count) const 1332 { return _RangeHash{}(__c, __bkt_count); } 1333 1334 std::size_t 1335 _M_bucket_index(const _Hash_node_value<_Value, false>& __n, 1336 std::size_t __bkt_count) const 1337 noexcept( noexcept(declval<const _Hash&>()(declval<const _Key&>())) 1338 && noexcept(declval<const _RangeHash&>()((__hash_code)0, 1339 (std::size_t)0)) ) 1340 { 1341 return _RangeHash{}(_M_hash_code(_ExtractKey{}(__n._M_v())), 1342 __bkt_count); 1343 } 1344 1345 std::size_t 1346 _M_bucket_index(const _Hash_node_value<_Value, true>& __n, 1347 std::size_t __bkt_count) const 1348 noexcept( noexcept(declval<const _RangeHash&>()((__hash_code)0, 1349 (std::size_t)0)) ) 1350 { return _RangeHash{}(__n._M_hash_code, __bkt_count); } 1351 1352 void 1353 _M_store_code(_Hash_node_code_cache<false>&, __hash_code) const 1354 { } 1355 1356 void 1357 _M_copy_code(_Hash_node_code_cache<false>&, 1358 const _Hash_node_code_cache<false>&) const 1359 { } 1360 1361 void 1362 _M_store_code(_Hash_node_code_cache<true>& __n, __hash_code __c) const 1363 { __n._M_hash_code = __c; } 1364 1365 void 1366 _M_copy_code(_Hash_node_code_cache<true>& __to, 1367 const _Hash_node_code_cache<true>& __from) const 1368 { __to._M_hash_code = __from._M_hash_code; } 1369 1370 void 1371 _M_swap(_Hash_code_base& __x) 1372 { std::swap(__ebo_hash::_M_get(), __x.__ebo_hash::_M_get()); } 1373 1374 const _Hash& 1375 _M_hash() const { return __ebo_hash::_M_cget(); } 1376 }; 1377 1378 /// Partial specialization used when nodes contain a cached hash code. 1379 template<typename _Key, typename _Value, typename _ExtractKey, 1380 typename _Hash, typename _RangeHash, typename _Unused> 1381 struct _Local_iterator_base<_Key, _Value, _ExtractKey, 1382 _Hash, _RangeHash, _Unused, true> 1383 : public _Node_iterator_base<_Value, true> 1384 { 1385 protected: 1386 using __base_node_iter = _Node_iterator_base<_Value, true>; 1387 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, 1388 _Hash, _RangeHash, _Unused, true>; 1389 1390 _Local_iterator_base() = default; 1391 _Local_iterator_base(const __hash_code_base&, 1392 _Hash_node<_Value, true>* __p, 1393 std::size_t __bkt, std::size_t __bkt_count) 1394 : __base_node_iter(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) 1395 { } 1396 1397 void 1398 _M_incr() 1399 { 1400 __base_node_iter::_M_incr(); 1401 if (this->_M_cur) 1402 { 1403 std::size_t __bkt 1404 = _RangeHash{}(this->_M_cur->_M_hash_code, _M_bucket_count); 1405 if (__bkt != _M_bucket) 1406 this->_M_cur = nullptr; 1407 } 1408 } 1409 1410 std::size_t _M_bucket; 1411 std::size_t _M_bucket_count; 1412 1413 public: 1414 std::size_t 1415 _M_get_bucket() const { return _M_bucket; } // for debug mode 1416 }; 1417 1418 // Uninitialized storage for a _Hash_code_base. 1419 // This type is DefaultConstructible and Assignable even if the 1420 // _Hash_code_base type isn't, so that _Local_iterator_base<..., false> 1421 // can be DefaultConstructible and Assignable. 1422 template<typename _Tp, bool _IsEmpty = std::is_empty<_Tp>::value> 1423 struct _Hash_code_storage 1424 { 1425 __gnu_cxx::__aligned_buffer<_Tp> _M_storage; 1426 1427 _Tp* 1428 _M_h() { return _M_storage._M_ptr(); } 1429 1430 const _Tp* 1431 _M_h() const { return _M_storage._M_ptr(); } 1432 }; 1433 1434 // Empty partial specialization for empty _Hash_code_base types. 1435 template<typename _Tp> 1436 struct _Hash_code_storage<_Tp, true> 1437 { 1438 static_assert( std::is_empty<_Tp>::value, "Type must be empty" ); 1439 1440 // As _Tp is an empty type there will be no bytes written/read through 1441 // the cast pointer, so no strict-aliasing violation. 1442 _Tp* 1443 _M_h() { return reinterpret_cast<_Tp*>(this); } 1444 1445 const _Tp* 1446 _M_h() const { return reinterpret_cast<const _Tp*>(this); } 1447 }; 1448 1449 template<typename _Key, typename _Value, typename _ExtractKey, 1450 typename _Hash, typename _RangeHash, typename _Unused> 1451 using __hash_code_for_local_iter 1452 = _Hash_code_storage<_Hash_code_base<_Key, _Value, _ExtractKey, 1453 _Hash, _RangeHash, _Unused, false>>; 1454 1455 // Partial specialization used when hash codes are not cached 1456 template<typename _Key, typename _Value, typename _ExtractKey, 1457 typename _Hash, typename _RangeHash, typename _Unused> 1458 struct _Local_iterator_base<_Key, _Value, _ExtractKey, 1459 _Hash, _RangeHash, _Unused, false> 1460 : __hash_code_for_local_iter<_Key, _Value, _ExtractKey, _Hash, _RangeHash, 1461 _Unused> 1462 , _Node_iterator_base<_Value, false> 1463 { 1464 protected: 1465 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, 1466 _Hash, _RangeHash, _Unused, false>; 1467 using __node_iter_base = _Node_iterator_base<_Value, false>; 1468 1469 _Local_iterator_base() : _M_bucket_count(-1) { } 1470 1471 _Local_iterator_base(const __hash_code_base& __base, 1472 _Hash_node<_Value, false>* __p, 1473 std::size_t __bkt, std::size_t __bkt_count) 1474 : __node_iter_base(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) 1475 { _M_init(__base); } 1476 1477 ~_Local_iterator_base() 1478 { 1479 if (_M_bucket_count != size_t(-1)) 1480 _M_destroy(); 1481 } 1482 1483 _Local_iterator_base(const _Local_iterator_base& __iter) 1484 : __node_iter_base(__iter._M_cur), _M_bucket(__iter._M_bucket) 1485 , _M_bucket_count(__iter._M_bucket_count) 1486 { 1487 if (_M_bucket_count != size_t(-1)) 1488 _M_init(*__iter._M_h()); 1489 } 1490 1491 _Local_iterator_base& 1492 operator=(const _Local_iterator_base& __iter) 1493 { 1494 if (_M_bucket_count != -1) 1495 _M_destroy(); 1496 this->_M_cur = __iter._M_cur; 1497 _M_bucket = __iter._M_bucket; 1498 _M_bucket_count = __iter._M_bucket_count; 1499 if (_M_bucket_count != -1) 1500 _M_init(*__iter._M_h()); 1501 return *this; 1502 } 1503 1504 void 1505 _M_incr() 1506 { 1507 __node_iter_base::_M_incr(); 1508 if (this->_M_cur) 1509 { 1510 std::size_t __bkt = this->_M_h()->_M_bucket_index(*this->_M_cur, 1511 _M_bucket_count); 1512 if (__bkt != _M_bucket) 1513 this->_M_cur = nullptr; 1514 } 1515 } 1516 1517 std::size_t _M_bucket; 1518 std::size_t _M_bucket_count; 1519 1520 void 1521 _M_init(const __hash_code_base& __base) 1522 { ::new(this->_M_h()) __hash_code_base(__base); } 1523 1524 void 1525 _M_destroy() { this->_M_h()->~__hash_code_base(); } 1526 1527 public: 1528 std::size_t 1529 _M_get_bucket() const { return _M_bucket; } // for debug mode 1530 }; 1531 1532 /// local iterators 1533 template<typename _Key, typename _Value, typename _ExtractKey, 1534 typename _Hash, typename _RangeHash, typename _Unused, 1535 bool __constant_iterators, bool __cache> 1536 struct _Local_iterator 1537 : public _Local_iterator_base<_Key, _Value, _ExtractKey, 1538 _Hash, _RangeHash, _Unused, __cache> 1539 { 1540 private: 1541 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey, 1542 _Hash, _RangeHash, _Unused, __cache>; 1543 using __hash_code_base = typename __base_type::__hash_code_base; 1544 1545 public: 1546 using value_type = _Value; 1547 using pointer = __conditional_t<__constant_iterators, 1548 const value_type*, value_type*>; 1549 using reference = __conditional_t<__constant_iterators, 1550 const value_type&, value_type&>; 1551 using difference_type = ptrdiff_t; 1552 using iterator_category = forward_iterator_tag; 1553 1554 _Local_iterator() = default; 1555 1556 _Local_iterator(const __hash_code_base& __base, 1557 _Hash_node<_Value, __cache>* __n, 1558 std::size_t __bkt, std::size_t __bkt_count) 1559 : __base_type(__base, __n, __bkt, __bkt_count) 1560 { } 1561 1562 reference 1563 operator*() const 1564 { return this->_M_cur->_M_v(); } 1565 1566 pointer 1567 operator->() const 1568 { return this->_M_cur->_M_valptr(); } 1569 1570 _Local_iterator& 1571 operator++() 1572 { 1573 this->_M_incr(); 1574 return *this; 1575 } 1576 1577 _Local_iterator 1578 operator++(int) 1579 { 1580 _Local_iterator __tmp(*this); 1581 this->_M_incr(); 1582 return __tmp; 1583 } 1584 }; 1585 1586 /// local const_iterators 1587 template<typename _Key, typename _Value, typename _ExtractKey, 1588 typename _Hash, typename _RangeHash, typename _Unused, 1589 bool __constant_iterators, bool __cache> 1590 struct _Local_const_iterator 1591 : public _Local_iterator_base<_Key, _Value, _ExtractKey, 1592 _Hash, _RangeHash, _Unused, __cache> 1593 { 1594 private: 1595 using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey, 1596 _Hash, _RangeHash, _Unused, __cache>; 1597 using __hash_code_base = typename __base_type::__hash_code_base; 1598 1599 public: 1600 typedef _Value value_type; 1601 typedef const value_type* pointer; 1602 typedef const value_type& reference; 1603 typedef std::ptrdiff_t difference_type; 1604 typedef std::forward_iterator_tag iterator_category; 1605 1606 _Local_const_iterator() = default; 1607 1608 _Local_const_iterator(const __hash_code_base& __base, 1609 _Hash_node<_Value, __cache>* __n, 1610 std::size_t __bkt, std::size_t __bkt_count) 1611 : __base_type(__base, __n, __bkt, __bkt_count) 1612 { } 1613 1614 _Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey, 1615 _Hash, _RangeHash, _Unused, 1616 __constant_iterators, 1617 __cache>& __x) 1618 : __base_type(__x) 1619 { } 1620 1621 reference 1622 operator*() const 1623 { return this->_M_cur->_M_v(); } 1624 1625 pointer 1626 operator->() const 1627 { return this->_M_cur->_M_valptr(); } 1628 1629 _Local_const_iterator& 1630 operator++() 1631 { 1632 this->_M_incr(); 1633 return *this; 1634 } 1635 1636 _Local_const_iterator 1637 operator++(int) 1638 { 1639 _Local_const_iterator __tmp(*this); 1640 this->_M_incr(); 1641 return __tmp; 1642 } 1643 }; 1644 1645 /** 1646 * Primary class template _Hashtable_base. 1647 * 1648 * Helper class adding management of _Equal functor to 1649 * _Hash_code_base type. 1650 * 1651 * Base class templates are: 1652 * - __detail::_Hash_code_base 1653 * - __detail::_Hashtable_ebo_helper 1654 */ 1655 template<typename _Key, typename _Value, typename _ExtractKey, 1656 typename _Equal, typename _Hash, typename _RangeHash, 1657 typename _Unused, typename _Traits> 1658 struct _Hashtable_base 1659 : public _Hash_code_base<_Key, _Value, _ExtractKey, _Hash, _RangeHash, 1660 _Unused, _Traits::__hash_cached::value>, 1661 private _Hashtable_ebo_helper<0, _Equal> 1662 { 1663 public: 1664 typedef _Key key_type; 1665 typedef _Value value_type; 1666 typedef _Equal key_equal; 1667 typedef std::size_t size_type; 1668 typedef std::ptrdiff_t difference_type; 1669 1670 using __traits_type = _Traits; 1671 using __hash_cached = typename __traits_type::__hash_cached; 1672 1673 using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey, 1674 _Hash, _RangeHash, _Unused, 1675 __hash_cached::value>; 1676 1677 using __hash_code = typename __hash_code_base::__hash_code; 1678 1679 private: 1680 using _EqualEBO = _Hashtable_ebo_helper<0, _Equal>; 1681 1682 static bool 1683 _S_equals(__hash_code, const _Hash_node_code_cache<false>&) 1684 { return true; } 1685 1686 static bool 1687 _S_node_equals(const _Hash_node_code_cache<false>&, 1688 const _Hash_node_code_cache<false>&) 1689 { return true; } 1690 1691 static bool 1692 _S_equals(__hash_code __c, const _Hash_node_code_cache<true>& __n) 1693 { return __c == __n._M_hash_code; } 1694 1695 static bool 1696 _S_node_equals(const _Hash_node_code_cache<true>& __lhn, 1697 const _Hash_node_code_cache<true>& __rhn) 1698 { return __lhn._M_hash_code == __rhn._M_hash_code; } 1699 1700 protected: 1701 _Hashtable_base() = default; 1702 1703 _Hashtable_base(const _Hash& __hash, const _Equal& __eq) 1704 : __hash_code_base(__hash), _EqualEBO(__eq) 1705 { } 1706 1707 bool 1708 _M_key_equals(const _Key& __k, 1709 const _Hash_node_value<_Value, 1710 __hash_cached::value>& __n) const 1711 { 1712 static_assert(__is_invocable<const _Equal&, const _Key&, const _Key&>{}, 1713 "key equality predicate must be invocable with two arguments of " 1714 "key type"); 1715 return _M_eq()(__k, _ExtractKey{}(__n._M_v())); 1716 } 1717 1718 template<typename _Kt> 1719 bool 1720 _M_key_equals_tr(const _Kt& __k, 1721 const _Hash_node_value<_Value, 1722 __hash_cached::value>& __n) const 1723 { 1724 static_assert( 1725 __is_invocable<const _Equal&, const _Kt&, const _Key&>{}, 1726 "key equality predicate must be invocable with two arguments of " 1727 "key type"); 1728 return _M_eq()(__k, _ExtractKey{}(__n._M_v())); 1729 } 1730 1731 bool 1732 _M_equals(const _Key& __k, __hash_code __c, 1733 const _Hash_node_value<_Value, __hash_cached::value>& __n) const 1734 { return _S_equals(__c, __n) && _M_key_equals(__k, __n); } 1735 1736 template<typename _Kt> 1737 bool 1738 _M_equals_tr(const _Kt& __k, __hash_code __c, 1739 const _Hash_node_value<_Value, 1740 __hash_cached::value>& __n) const 1741 { return _S_equals(__c, __n) && _M_key_equals_tr(__k, __n); } 1742 1743 bool 1744 _M_node_equals( 1745 const _Hash_node_value<_Value, __hash_cached::value>& __lhn, 1746 const _Hash_node_value<_Value, __hash_cached::value>& __rhn) const 1747 { 1748 return _S_node_equals(__lhn, __rhn) 1749 && _M_key_equals(_ExtractKey{}(__lhn._M_v()), __rhn); 1750 } 1751 1752 void 1753 _M_swap(_Hashtable_base& __x) 1754 { 1755 __hash_code_base::_M_swap(__x); 1756 std::swap(_EqualEBO::_M_get(), __x._EqualEBO::_M_get()); 1757 } 1758 1759 const _Equal& 1760 _M_eq() const { return _EqualEBO::_M_cget(); } 1761 }; 1762 1763 /** 1764 * Primary class template _Equality. 1765 * 1766 * This is for implementing equality comparison for unordered 1767 * containers, per N3068, by John Lakos and Pablo Halpern. 1768 * Algorithmically, we follow closely the reference implementations 1769 * therein. 1770 */ 1771 template<typename _Key, typename _Value, typename _Alloc, 1772 typename _ExtractKey, typename _Equal, 1773 typename _Hash, typename _RangeHash, typename _Unused, 1774 typename _RehashPolicy, typename _Traits, 1775 bool _Unique_keys = _Traits::__unique_keys::value> 1776 struct _Equality; 1777 1778 /// unordered_map and unordered_set specializations. 1779 template<typename _Key, typename _Value, typename _Alloc, 1780 typename _ExtractKey, typename _Equal, 1781 typename _Hash, typename _RangeHash, typename _Unused, 1782 typename _RehashPolicy, typename _Traits> 1783 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1784 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, true> 1785 { 1786 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1787 _Hash, _RangeHash, _Unused, 1788 _RehashPolicy, _Traits>; 1789 1790 bool 1791 _M_equal(const __hashtable&) const; 1792 }; 1793 1794 template<typename _Key, typename _Value, typename _Alloc, 1795 typename _ExtractKey, typename _Equal, 1796 typename _Hash, typename _RangeHash, typename _Unused, 1797 typename _RehashPolicy, typename _Traits> 1798 bool 1799 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1800 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, true>:: 1801 _M_equal(const __hashtable& __other) const 1802 { 1803 using __node_type = typename __hashtable::__node_type; 1804 const __hashtable* __this = static_cast<const __hashtable*>(this); 1805 if (__this->size() != __other.size()) 1806 return false; 1807 1808 for (auto __itx = __this->begin(); __itx != __this->end(); ++__itx) 1809 { 1810 std::size_t __ybkt = __other._M_bucket_index(*__itx._M_cur); 1811 auto __prev_n = __other._M_buckets[__ybkt]; 1812 if (!__prev_n) 1813 return false; 1814 1815 for (__node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt);; 1816 __n = __n->_M_next()) 1817 { 1818 if (__n->_M_v() == *__itx) 1819 break; 1820 1821 if (!__n->_M_nxt 1822 || __other._M_bucket_index(*__n->_M_next()) != __ybkt) 1823 return false; 1824 } 1825 } 1826 1827 return true; 1828 } 1829 1830 /// unordered_multiset and unordered_multimap specializations. 1831 template<typename _Key, typename _Value, typename _Alloc, 1832 typename _ExtractKey, typename _Equal, 1833 typename _Hash, typename _RangeHash, typename _Unused, 1834 typename _RehashPolicy, typename _Traits> 1835 struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1836 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, false> 1837 { 1838 using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1839 _Hash, _RangeHash, _Unused, 1840 _RehashPolicy, _Traits>; 1841 1842 bool 1843 _M_equal(const __hashtable&) const; 1844 }; 1845 1846 template<typename _Key, typename _Value, typename _Alloc, 1847 typename _ExtractKey, typename _Equal, 1848 typename _Hash, typename _RangeHash, typename _Unused, 1849 typename _RehashPolicy, typename _Traits> 1850 bool 1851 _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 1852 _Hash, _RangeHash, _Unused, _RehashPolicy, _Traits, false>:: 1853 _M_equal(const __hashtable& __other) const 1854 { 1855 using __node_type = typename __hashtable::__node_type; 1856 const __hashtable* __this = static_cast<const __hashtable*>(this); 1857 if (__this->size() != __other.size()) 1858 return false; 1859 1860 for (auto __itx = __this->begin(); __itx != __this->end();) 1861 { 1862 std::size_t __x_count = 1; 1863 auto __itx_end = __itx; 1864 for (++__itx_end; __itx_end != __this->end() 1865 && __this->key_eq()(_ExtractKey{}(*__itx), 1866 _ExtractKey{}(*__itx_end)); 1867 ++__itx_end) 1868 ++__x_count; 1869 1870 std::size_t __ybkt = __other._M_bucket_index(*__itx._M_cur); 1871 auto __y_prev_n = __other._M_buckets[__ybkt]; 1872 if (!__y_prev_n) 1873 return false; 1874 1875 __node_type* __y_n = static_cast<__node_type*>(__y_prev_n->_M_nxt); 1876 for (;;) 1877 { 1878 if (__this->key_eq()(_ExtractKey{}(__y_n->_M_v()), 1879 _ExtractKey{}(*__itx))) 1880 break; 1881 1882 auto __y_ref_n = __y_n; 1883 for (__y_n = __y_n->_M_next(); __y_n; __y_n = __y_n->_M_next()) 1884 if (!__other._M_node_equals(*__y_ref_n, *__y_n)) 1885 break; 1886 1887 if (!__y_n || __other._M_bucket_index(*__y_n) != __ybkt) 1888 return false; 1889 } 1890 1891 typename __hashtable::const_iterator __ity(__y_n); 1892 for (auto __ity_end = __ity; __ity_end != __other.end(); ++__ity_end) 1893 if (--__x_count == 0) 1894 break; 1895 1896 if (__x_count != 0) 1897 return false; 1898 1899 if (!std::is_permutation(__itx, __itx_end, __ity)) 1900 return false; 1901 1902 __itx = __itx_end; 1903 } 1904 return true; 1905 } 1906 1907 /** 1908 * This type deals with all allocation and keeps an allocator instance 1909 * through inheritance to benefit from EBO when possible. 1910 */ 1911 template<typename _NodeAlloc> 1912 struct _Hashtable_alloc : private _Hashtable_ebo_helper<0, _NodeAlloc> 1913 { 1914 private: 1915 using __ebo_node_alloc = _Hashtable_ebo_helper<0, _NodeAlloc>; 1916 1917 template<typename> 1918 struct __get_value_type; 1919 template<typename _Val, bool _Cache_hash_code> 1920 struct __get_value_type<_Hash_node<_Val, _Cache_hash_code>> 1921 { using type = _Val; }; 1922 1923 public: 1924 using __node_type = typename _NodeAlloc::value_type; 1925 using __node_alloc_type = _NodeAlloc; 1926 // Use __gnu_cxx to benefit from _S_always_equal and al. 1927 using __node_alloc_traits = __gnu_cxx::__alloc_traits<__node_alloc_type>; 1928 1929 using __value_alloc_traits = typename __node_alloc_traits::template 1930 rebind_traits<typename __get_value_type<__node_type>::type>; 1931 1932 using __node_ptr = __node_type*; 1933 using __node_base = _Hash_node_base; 1934 using __node_base_ptr = __node_base*; 1935 using __buckets_alloc_type = 1936 __alloc_rebind<__node_alloc_type, __node_base_ptr>; 1937 using __buckets_alloc_traits = std::allocator_traits<__buckets_alloc_type>; 1938 using __buckets_ptr = __node_base_ptr*; 1939 1940 _Hashtable_alloc() = default; 1941 _Hashtable_alloc(const _Hashtable_alloc&) = default; 1942 _Hashtable_alloc(_Hashtable_alloc&&) = default; 1943 1944 template<typename _Alloc> 1945 _Hashtable_alloc(_Alloc&& __a) 1946 : __ebo_node_alloc(std::forward<_Alloc>(__a)) 1947 { } 1948 1949 __node_alloc_type& 1950 _M_node_allocator() 1951 { return __ebo_node_alloc::_M_get(); } 1952 1953 const __node_alloc_type& 1954 _M_node_allocator() const 1955 { return __ebo_node_alloc::_M_cget(); } 1956 1957 // Allocate a node and construct an element within it. 1958 template<typename... _Args> 1959 __node_ptr 1960 _M_allocate_node(_Args&&... __args); 1961 1962 // Destroy the element within a node and deallocate the node. 1963 void 1964 _M_deallocate_node(__node_ptr __n); 1965 1966 // Deallocate a node. 1967 void 1968 _M_deallocate_node_ptr(__node_ptr __n); 1969 1970 // Deallocate the linked list of nodes pointed to by __n. 1971 // The elements within the nodes are destroyed. 1972 void 1973 _M_deallocate_nodes(__node_ptr __n); 1974 1975 __buckets_ptr 1976 _M_allocate_buckets(std::size_t __bkt_count); 1977 1978 void 1979 _M_deallocate_buckets(__buckets_ptr, std::size_t __bkt_count); 1980 }; 1981 1982 // Definitions of class template _Hashtable_alloc's out-of-line member 1983 // functions. 1984 template<typename _NodeAlloc> 1985 template<typename... _Args> 1986 auto 1987 _Hashtable_alloc<_NodeAlloc>::_M_allocate_node(_Args&&... __args) 1988 -> __node_ptr 1989 { 1990 auto __nptr = __node_alloc_traits::allocate(_M_node_allocator(), 1); 1991 __node_ptr __n = std::__to_address(__nptr); 1992 __try 1993 { 1994 ::new ((void*)__n) __node_type; 1995 __node_alloc_traits::construct(_M_node_allocator(), 1996 __n->_M_valptr(), 1997 std::forward<_Args>(__args)...); 1998 return __n; 1999 } 2000 __catch(...) 2001 { 2002 __node_alloc_traits::deallocate(_M_node_allocator(), __nptr, 1); 2003 __throw_exception_again; 2004 } 2005 } 2006 2007 template<typename _NodeAlloc> 2008 void 2009 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node(__node_ptr __n) 2010 { 2011 __node_alloc_traits::destroy(_M_node_allocator(), __n->_M_valptr()); 2012 _M_deallocate_node_ptr(__n); 2013 } 2014 2015 template<typename _NodeAlloc> 2016 void 2017 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_node_ptr(__node_ptr __n) 2018 { 2019 typedef typename __node_alloc_traits::pointer _Ptr; 2020 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__n); 2021 __n->~__node_type(); 2022 __node_alloc_traits::deallocate(_M_node_allocator(), __ptr, 1); 2023 } 2024 2025 template<typename _NodeAlloc> 2026 void 2027 _Hashtable_alloc<_NodeAlloc>::_M_deallocate_nodes(__node_ptr __n) 2028 { 2029 while (__n) 2030 { 2031 __node_ptr __tmp = __n; 2032 __n = __n->_M_next(); 2033 _M_deallocate_node(__tmp); 2034 } 2035 } 2036 2037 template<typename _NodeAlloc> 2038 auto 2039 _Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets(std::size_t __bkt_count) 2040 -> __buckets_ptr 2041 { 2042 __buckets_alloc_type __alloc(_M_node_allocator()); 2043 2044 auto __ptr = __buckets_alloc_traits::allocate(__alloc, __bkt_count); 2045 __buckets_ptr __p = std::__to_address(__ptr); 2046 __builtin_memset(__p, 0, __bkt_count * sizeof(__node_base_ptr)); 2047 return __p; 2048 } 2049 2050 template<typename _NodeAlloc> 2051 void 2052 _Hashtable_alloc<_NodeAlloc>:: 2053 _M_deallocate_buckets(__buckets_ptr __bkts, 2054 std::size_t __bkt_count) 2055 { 2056 typedef typename __buckets_alloc_traits::pointer _Ptr; 2057 auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__bkts); 2058 __buckets_alloc_type __alloc(_M_node_allocator()); 2059 __buckets_alloc_traits::deallocate(__alloc, __ptr, __bkt_count); 2060 } 2061 2062 ///@} hashtable-detail 2063 } // namespace __detail 2064 /// @endcond 2065 _GLIBCXX_END_NAMESPACE_VERSION 2066 } // namespace std 2067 2068 #endif // _HASHTABLE_POLICY_H
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