libstdc++
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00001 // hashtable.h header -*- C++ -*- 00002 00003 // Copyright (C) 2007-2019 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /** @file bits/hashtable.h 00026 * This is an internal header file, included by other library headers. 00027 * Do not attempt to use it directly. @headername{unordered_map, unordered_set} 00028 */ 00029 00030 #ifndef _HASHTABLE_H 00031 #define _HASHTABLE_H 1 00032 00033 #pragma GCC system_header 00034 00035 #include <bits/hashtable_policy.h> 00036 #if __cplusplus > 201402L 00037 # include <bits/node_handle.h> 00038 #endif 00039 00040 namespace std _GLIBCXX_VISIBILITY(default) 00041 { 00042 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00043 00044 template<typename _Tp, typename _Hash> 00045 using __cache_default 00046 = __not_<__and_<// Do not cache for fast hasher. 00047 __is_fast_hash<_Hash>, 00048 // Mandatory to have erase not throwing. 00049 __is_nothrow_invocable<const _Hash&, const _Tp&>>>; 00050 00051 /** 00052 * Primary class template _Hashtable. 00053 * 00054 * @ingroup hashtable-detail 00055 * 00056 * @tparam _Value CopyConstructible type. 00057 * 00058 * @tparam _Key CopyConstructible type. 00059 * 00060 * @tparam _Alloc An allocator type 00061 * ([lib.allocator.requirements]) whose _Alloc::value_type is 00062 * _Value. As a conforming extension, we allow for 00063 * _Alloc::value_type != _Value. 00064 * 00065 * @tparam _ExtractKey Function object that takes an object of type 00066 * _Value and returns a value of type _Key. 00067 * 00068 * @tparam _Equal Function object that takes two objects of type k 00069 * and returns a bool-like value that is true if the two objects 00070 * are considered equal. 00071 * 00072 * @tparam _H1 The hash function. A unary function object with 00073 * argument type _Key and result type size_t. Return values should 00074 * be distributed over the entire range [0, numeric_limits<size_t>:::max()]. 00075 * 00076 * @tparam _H2 The range-hashing function (in the terminology of 00077 * Tavori and Dreizin). A binary function object whose argument 00078 * types and result type are all size_t. Given arguments r and N, 00079 * the return value is in the range [0, N). 00080 * 00081 * @tparam _Hash The ranged hash function (Tavori and Dreizin). A 00082 * binary function whose argument types are _Key and size_t and 00083 * whose result type is size_t. Given arguments k and N, the 00084 * return value is in the range [0, N). Default: hash(k, N) = 00085 * h2(h1(k), N). If _Hash is anything other than the default, _H1 00086 * and _H2 are ignored. 00087 * 00088 * @tparam _RehashPolicy Policy class with three members, all of 00089 * which govern the bucket count. _M_next_bkt(n) returns a bucket 00090 * count no smaller than n. _M_bkt_for_elements(n) returns a 00091 * bucket count appropriate for an element count of n. 00092 * _M_need_rehash(n_bkt, n_elt, n_ins) determines whether, if the 00093 * current bucket count is n_bkt and the current element count is 00094 * n_elt, we need to increase the bucket count. If so, returns 00095 * make_pair(true, n), where n is the new bucket count. If not, 00096 * returns make_pair(false, <anything>) 00097 * 00098 * @tparam _Traits Compile-time class with three boolean 00099 * std::integral_constant members: __cache_hash_code, __constant_iterators, 00100 * __unique_keys. 00101 * 00102 * Each _Hashtable data structure has: 00103 * 00104 * - _Bucket[] _M_buckets 00105 * - _Hash_node_base _M_before_begin 00106 * - size_type _M_bucket_count 00107 * - size_type _M_element_count 00108 * 00109 * with _Bucket being _Hash_node* and _Hash_node containing: 00110 * 00111 * - _Hash_node* _M_next 00112 * - Tp _M_value 00113 * - size_t _M_hash_code if cache_hash_code is true 00114 * 00115 * In terms of Standard containers the hashtable is like the aggregation of: 00116 * 00117 * - std::forward_list<_Node> containing the elements 00118 * - std::vector<std::forward_list<_Node>::iterator> representing the buckets 00119 * 00120 * The non-empty buckets contain the node before the first node in the 00121 * bucket. This design makes it possible to implement something like a 00122 * std::forward_list::insert_after on container insertion and 00123 * std::forward_list::erase_after on container erase 00124 * calls. _M_before_begin is equivalent to 00125 * std::forward_list::before_begin. Empty buckets contain 00126 * nullptr. Note that one of the non-empty buckets contains 00127 * &_M_before_begin which is not a dereferenceable node so the 00128 * node pointer in a bucket shall never be dereferenced, only its 00129 * next node can be. 00130 * 00131 * Walking through a bucket's nodes requires a check on the hash code to 00132 * see if each node is still in the bucket. Such a design assumes a 00133 * quite efficient hash functor and is one of the reasons it is 00134 * highly advisable to set __cache_hash_code to true. 00135 * 00136 * The container iterators are simply built from nodes. This way 00137 * incrementing the iterator is perfectly efficient independent of 00138 * how many empty buckets there are in the container. 00139 * 00140 * On insert we compute the element's hash code and use it to find the 00141 * bucket index. If the element must be inserted in an empty bucket 00142 * we add it at the beginning of the singly linked list and make the 00143 * bucket point to _M_before_begin. The bucket that used to point to 00144 * _M_before_begin, if any, is updated to point to its new before 00145 * begin node. 00146 * 00147 * On erase, the simple iterator design requires using the hash 00148 * functor to get the index of the bucket to update. For this 00149 * reason, when __cache_hash_code is set to false the hash functor must 00150 * not throw and this is enforced by a static assertion. 00151 * 00152 * Functionality is implemented by decomposition into base classes, 00153 * where the derived _Hashtable class is used in _Map_base, 00154 * _Insert, _Rehash_base, and _Equality base classes to access the 00155 * "this" pointer. _Hashtable_base is used in the base classes as a 00156 * non-recursive, fully-completed-type so that detailed nested type 00157 * information, such as iterator type and node type, can be 00158 * used. This is similar to the "Curiously Recurring Template 00159 * Pattern" (CRTP) technique, but uses a reconstructed, not 00160 * explicitly passed, template pattern. 00161 * 00162 * Base class templates are: 00163 * - __detail::_Hashtable_base 00164 * - __detail::_Map_base 00165 * - __detail::_Insert 00166 * - __detail::_Rehash_base 00167 * - __detail::_Equality 00168 */ 00169 template<typename _Key, typename _Value, typename _Alloc, 00170 typename _ExtractKey, typename _Equal, 00171 typename _H1, typename _H2, typename _Hash, 00172 typename _RehashPolicy, typename _Traits> 00173 class _Hashtable 00174 : public __detail::_Hashtable_base<_Key, _Value, _ExtractKey, _Equal, 00175 _H1, _H2, _Hash, _Traits>, 00176 public __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 00177 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 00178 public __detail::_Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, 00179 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 00180 public __detail::_Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, 00181 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 00182 public __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal, 00183 _H1, _H2, _Hash, _RehashPolicy, _Traits>, 00184 private __detail::_Hashtable_alloc< 00185 __alloc_rebind<_Alloc, 00186 __detail::_Hash_node<_Value, 00187 _Traits::__hash_cached::value>>> 00188 { 00189 static_assert(is_same<typename remove_cv<_Value>::type, _Value>::value, 00190 "unordered container must have a non-const, non-volatile value_type"); 00191 #ifdef __STRICT_ANSI__ 00192 static_assert(is_same<typename _Alloc::value_type, _Value>{}, 00193 "unordered container must have the same value_type as its allocator"); 00194 #endif 00195 00196 using __traits_type = _Traits; 00197 using __hash_cached = typename __traits_type::__hash_cached; 00198 using __node_type = __detail::_Hash_node<_Value, __hash_cached::value>; 00199 using __node_alloc_type = __alloc_rebind<_Alloc, __node_type>; 00200 00201 using __hashtable_alloc = __detail::_Hashtable_alloc<__node_alloc_type>; 00202 00203 using __value_alloc_traits = 00204 typename __hashtable_alloc::__value_alloc_traits; 00205 using __node_alloc_traits = 00206 typename __hashtable_alloc::__node_alloc_traits; 00207 using __node_base = typename __hashtable_alloc::__node_base; 00208 using __bucket_type = typename __hashtable_alloc::__bucket_type; 00209 00210 public: 00211 typedef _Key key_type; 00212 typedef _Value value_type; 00213 typedef _Alloc allocator_type; 00214 typedef _Equal key_equal; 00215 00216 // mapped_type, if present, comes from _Map_base. 00217 // hasher, if present, comes from _Hash_code_base/_Hashtable_base. 00218 typedef typename __value_alloc_traits::pointer pointer; 00219 typedef typename __value_alloc_traits::const_pointer const_pointer; 00220 typedef value_type& reference; 00221 typedef const value_type& const_reference; 00222 00223 private: 00224 using __rehash_type = _RehashPolicy; 00225 using __rehash_state = typename __rehash_type::_State; 00226 00227 using __constant_iterators = typename __traits_type::__constant_iterators; 00228 using __unique_keys = typename __traits_type::__unique_keys; 00229 00230 using __key_extract = typename std::conditional< 00231 __constant_iterators::value, 00232 __detail::_Identity, 00233 __detail::_Select1st>::type; 00234 00235 using __hashtable_base = __detail:: 00236 _Hashtable_base<_Key, _Value, _ExtractKey, 00237 _Equal, _H1, _H2, _Hash, _Traits>; 00238 00239 using __hash_code_base = typename __hashtable_base::__hash_code_base; 00240 using __hash_code = typename __hashtable_base::__hash_code; 00241 using __ireturn_type = typename __hashtable_base::__ireturn_type; 00242 00243 using __map_base = __detail::_Map_base<_Key, _Value, _Alloc, _ExtractKey, 00244 _Equal, _H1, _H2, _Hash, 00245 _RehashPolicy, _Traits>; 00246 00247 using __rehash_base = __detail::_Rehash_base<_Key, _Value, _Alloc, 00248 _ExtractKey, _Equal, 00249 _H1, _H2, _Hash, 00250 _RehashPolicy, _Traits>; 00251 00252 using __eq_base = __detail::_Equality<_Key, _Value, _Alloc, _ExtractKey, 00253 _Equal, _H1, _H2, _Hash, 00254 _RehashPolicy, _Traits>; 00255 00256 using __reuse_or_alloc_node_type = 00257 __detail::_ReuseOrAllocNode<__node_alloc_type>; 00258 00259 // Metaprogramming for picking apart hash caching. 00260 template<typename _Cond> 00261 using __if_hash_cached = __or_<__not_<__hash_cached>, _Cond>; 00262 00263 template<typename _Cond> 00264 using __if_hash_not_cached = __or_<__hash_cached, _Cond>; 00265 00266 // Compile-time diagnostics. 00267 00268 // _Hash_code_base has everything protected, so use this derived type to 00269 // access it. 00270 struct __hash_code_base_access : __hash_code_base 00271 { using __hash_code_base::_M_bucket_index; }; 00272 00273 // Getting a bucket index from a node shall not throw because it is used 00274 // in methods (erase, swap...) that shall not throw. 00275 static_assert(noexcept(declval<const __hash_code_base_access&>() 00276 ._M_bucket_index((const __node_type*)nullptr, 00277 (std::size_t)0)), 00278 "Cache the hash code or qualify your functors involved" 00279 " in hash code and bucket index computation with noexcept"); 00280 00281 // Following two static assertions are necessary to guarantee 00282 // that local_iterator will be default constructible. 00283 00284 // When hash codes are cached local iterator inherits from H2 functor 00285 // which must then be default constructible. 00286 static_assert(__if_hash_cached<is_default_constructible<_H2>>::value, 00287 "Functor used to map hash code to bucket index" 00288 " must be default constructible"); 00289 00290 template<typename _Keya, typename _Valuea, typename _Alloca, 00291 typename _ExtractKeya, typename _Equala, 00292 typename _H1a, typename _H2a, typename _Hasha, 00293 typename _RehashPolicya, typename _Traitsa, 00294 bool _Unique_keysa> 00295 friend struct __detail::_Map_base; 00296 00297 template<typename _Keya, typename _Valuea, typename _Alloca, 00298 typename _ExtractKeya, typename _Equala, 00299 typename _H1a, typename _H2a, typename _Hasha, 00300 typename _RehashPolicya, typename _Traitsa> 00301 friend struct __detail::_Insert_base; 00302 00303 template<typename _Keya, typename _Valuea, typename _Alloca, 00304 typename _ExtractKeya, typename _Equala, 00305 typename _H1a, typename _H2a, typename _Hasha, 00306 typename _RehashPolicya, typename _Traitsa, 00307 bool _Constant_iteratorsa> 00308 friend struct __detail::_Insert; 00309 00310 public: 00311 using size_type = typename __hashtable_base::size_type; 00312 using difference_type = typename __hashtable_base::difference_type; 00313 00314 using iterator = typename __hashtable_base::iterator; 00315 using const_iterator = typename __hashtable_base::const_iterator; 00316 00317 using local_iterator = typename __hashtable_base::local_iterator; 00318 using const_local_iterator = typename __hashtable_base:: 00319 const_local_iterator; 00320 00321 #if __cplusplus > 201402L 00322 using node_type = _Node_handle<_Key, _Value, __node_alloc_type>; 00323 using insert_return_type = _Node_insert_return<iterator, node_type>; 00324 #endif 00325 00326 private: 00327 __bucket_type* _M_buckets = &_M_single_bucket; 00328 size_type _M_bucket_count = 1; 00329 __node_base _M_before_begin; 00330 size_type _M_element_count = 0; 00331 _RehashPolicy _M_rehash_policy; 00332 00333 // A single bucket used when only need for 1 bucket. Especially 00334 // interesting in move semantic to leave hashtable with only 1 buckets 00335 // which is not allocated so that we can have those operations noexcept 00336 // qualified. 00337 // Note that we can't leave hashtable with 0 bucket without adding 00338 // numerous checks in the code to avoid 0 modulus. 00339 __bucket_type _M_single_bucket = nullptr; 00340 00341 bool 00342 _M_uses_single_bucket(__bucket_type* __bkts) const 00343 { return __builtin_expect(__bkts == &_M_single_bucket, false); } 00344 00345 bool 00346 _M_uses_single_bucket() const 00347 { return _M_uses_single_bucket(_M_buckets); } 00348 00349 __hashtable_alloc& 00350 _M_base_alloc() { return *this; } 00351 00352 __bucket_type* 00353 _M_allocate_buckets(size_type __n) 00354 { 00355 if (__builtin_expect(__n == 1, false)) 00356 { 00357 _M_single_bucket = nullptr; 00358 return &_M_single_bucket; 00359 } 00360 00361 return __hashtable_alloc::_M_allocate_buckets(__n); 00362 } 00363 00364 void 00365 _M_deallocate_buckets(__bucket_type* __bkts, size_type __n) 00366 { 00367 if (_M_uses_single_bucket(__bkts)) 00368 return; 00369 00370 __hashtable_alloc::_M_deallocate_buckets(__bkts, __n); 00371 } 00372 00373 void 00374 _M_deallocate_buckets() 00375 { _M_deallocate_buckets(_M_buckets, _M_bucket_count); } 00376 00377 // Gets bucket begin, deals with the fact that non-empty buckets contain 00378 // their before begin node. 00379 __node_type* 00380 _M_bucket_begin(size_type __bkt) const; 00381 00382 __node_type* 00383 _M_begin() const 00384 { return static_cast<__node_type*>(_M_before_begin._M_nxt); } 00385 00386 // Assign *this using another _Hashtable instance. Either elements 00387 // are copy or move depends on the _NodeGenerator. 00388 template<typename _Ht, typename _NodeGenerator> 00389 void 00390 _M_assign_elements(_Ht&&, const _NodeGenerator&); 00391 00392 template<typename _NodeGenerator> 00393 void 00394 _M_assign(const _Hashtable&, const _NodeGenerator&); 00395 00396 void 00397 _M_move_assign(_Hashtable&&, std::true_type); 00398 00399 void 00400 _M_move_assign(_Hashtable&&, std::false_type); 00401 00402 void 00403 _M_reset() noexcept; 00404 00405 _Hashtable(const _H1& __h1, const _H2& __h2, const _Hash& __h, 00406 const _Equal& __eq, const _ExtractKey& __exk, 00407 const allocator_type& __a) 00408 : __hashtable_base(__exk, __h1, __h2, __h, __eq), 00409 __hashtable_alloc(__node_alloc_type(__a)) 00410 { } 00411 00412 public: 00413 // Constructor, destructor, assignment, swap 00414 _Hashtable() = default; 00415 _Hashtable(size_type __bucket_hint, 00416 const _H1&, const _H2&, const _Hash&, 00417 const _Equal&, const _ExtractKey&, 00418 const allocator_type&); 00419 00420 template<typename _InputIterator> 00421 _Hashtable(_InputIterator __first, _InputIterator __last, 00422 size_type __bucket_hint, 00423 const _H1&, const _H2&, const _Hash&, 00424 const _Equal&, const _ExtractKey&, 00425 const allocator_type&); 00426 00427 _Hashtable(const _Hashtable&); 00428 00429 _Hashtable(_Hashtable&&) noexcept; 00430 00431 _Hashtable(const _Hashtable&, const allocator_type&); 00432 00433 _Hashtable(_Hashtable&&, const allocator_type&); 00434 00435 // Use delegating constructors. 00436 explicit 00437 _Hashtable(const allocator_type& __a) 00438 : __hashtable_alloc(__node_alloc_type(__a)) 00439 { } 00440 00441 explicit 00442 _Hashtable(size_type __n, 00443 const _H1& __hf = _H1(), 00444 const key_equal& __eql = key_equal(), 00445 const allocator_type& __a = allocator_type()) 00446 : _Hashtable(__n, __hf, _H2(), _Hash(), __eql, 00447 __key_extract(), __a) 00448 { } 00449 00450 template<typename _InputIterator> 00451 _Hashtable(_InputIterator __f, _InputIterator __l, 00452 size_type __n = 0, 00453 const _H1& __hf = _H1(), 00454 const key_equal& __eql = key_equal(), 00455 const allocator_type& __a = allocator_type()) 00456 : _Hashtable(__f, __l, __n, __hf, _H2(), _Hash(), __eql, 00457 __key_extract(), __a) 00458 { } 00459 00460 _Hashtable(initializer_list<value_type> __l, 00461 size_type __n = 0, 00462 const _H1& __hf = _H1(), 00463 const key_equal& __eql = key_equal(), 00464 const allocator_type& __a = allocator_type()) 00465 : _Hashtable(__l.begin(), __l.end(), __n, __hf, _H2(), _Hash(), __eql, 00466 __key_extract(), __a) 00467 { } 00468 00469 _Hashtable& 00470 operator=(const _Hashtable& __ht); 00471 00472 _Hashtable& 00473 operator=(_Hashtable&& __ht) 00474 noexcept(__node_alloc_traits::_S_nothrow_move() 00475 && is_nothrow_move_assignable<_H1>::value 00476 && is_nothrow_move_assignable<_Equal>::value) 00477 { 00478 constexpr bool __move_storage = 00479 __node_alloc_traits::_S_propagate_on_move_assign() 00480 || __node_alloc_traits::_S_always_equal(); 00481 _M_move_assign(std::move(__ht), __bool_constant<__move_storage>()); 00482 return *this; 00483 } 00484 00485 _Hashtable& 00486 operator=(initializer_list<value_type> __l) 00487 { 00488 __reuse_or_alloc_node_type __roan(_M_begin(), *this); 00489 _M_before_begin._M_nxt = nullptr; 00490 clear(); 00491 this->_M_insert_range(__l.begin(), __l.end(), __roan, __unique_keys()); 00492 return *this; 00493 } 00494 00495 ~_Hashtable() noexcept; 00496 00497 void 00498 swap(_Hashtable&) 00499 noexcept(__and_<__is_nothrow_swappable<_H1>, 00500 __is_nothrow_swappable<_Equal>>::value); 00501 00502 // Basic container operations 00503 iterator 00504 begin() noexcept 00505 { return iterator(_M_begin()); } 00506 00507 const_iterator 00508 begin() const noexcept 00509 { return const_iterator(_M_begin()); } 00510 00511 iterator 00512 end() noexcept 00513 { return iterator(nullptr); } 00514 00515 const_iterator 00516 end() const noexcept 00517 { return const_iterator(nullptr); } 00518 00519 const_iterator 00520 cbegin() const noexcept 00521 { return const_iterator(_M_begin()); } 00522 00523 const_iterator 00524 cend() const noexcept 00525 { return const_iterator(nullptr); } 00526 00527 size_type 00528 size() const noexcept 00529 { return _M_element_count; } 00530 00531 _GLIBCXX_NODISCARD bool 00532 empty() const noexcept 00533 { return size() == 0; } 00534 00535 allocator_type 00536 get_allocator() const noexcept 00537 { return allocator_type(this->_M_node_allocator()); } 00538 00539 size_type 00540 max_size() const noexcept 00541 { return __node_alloc_traits::max_size(this->_M_node_allocator()); } 00542 00543 // Observers 00544 key_equal 00545 key_eq() const 00546 { return this->_M_eq(); } 00547 00548 // hash_function, if present, comes from _Hash_code_base. 00549 00550 // Bucket operations 00551 size_type 00552 bucket_count() const noexcept 00553 { return _M_bucket_count; } 00554 00555 size_type 00556 max_bucket_count() const noexcept 00557 { return max_size(); } 00558 00559 size_type 00560 bucket_size(size_type __n) const 00561 { return std::distance(begin(__n), end(__n)); } 00562 00563 size_type 00564 bucket(const key_type& __k) const 00565 { return _M_bucket_index(__k, this->_M_hash_code(__k)); } 00566 00567 local_iterator 00568 begin(size_type __n) 00569 { 00570 return local_iterator(*this, _M_bucket_begin(__n), 00571 __n, _M_bucket_count); 00572 } 00573 00574 local_iterator 00575 end(size_type __n) 00576 { return local_iterator(*this, nullptr, __n, _M_bucket_count); } 00577 00578 const_local_iterator 00579 begin(size_type __n) const 00580 { 00581 return const_local_iterator(*this, _M_bucket_begin(__n), 00582 __n, _M_bucket_count); 00583 } 00584 00585 const_local_iterator 00586 end(size_type __n) const 00587 { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); } 00588 00589 // DR 691. 00590 const_local_iterator 00591 cbegin(size_type __n) const 00592 { 00593 return const_local_iterator(*this, _M_bucket_begin(__n), 00594 __n, _M_bucket_count); 00595 } 00596 00597 const_local_iterator 00598 cend(size_type __n) const 00599 { return const_local_iterator(*this, nullptr, __n, _M_bucket_count); } 00600 00601 float 00602 load_factor() const noexcept 00603 { 00604 return static_cast<float>(size()) / static_cast<float>(bucket_count()); 00605 } 00606 00607 // max_load_factor, if present, comes from _Rehash_base. 00608 00609 // Generalization of max_load_factor. Extension, not found in 00610 // TR1. Only useful if _RehashPolicy is something other than 00611 // the default. 00612 const _RehashPolicy& 00613 __rehash_policy() const 00614 { return _M_rehash_policy; } 00615 00616 void 00617 __rehash_policy(const _RehashPolicy& __pol) 00618 { _M_rehash_policy = __pol; } 00619 00620 // Lookup. 00621 iterator 00622 find(const key_type& __k); 00623 00624 const_iterator 00625 find(const key_type& __k) const; 00626 00627 size_type 00628 count(const key_type& __k) const; 00629 00630 std::pair<iterator, iterator> 00631 equal_range(const key_type& __k); 00632 00633 std::pair<const_iterator, const_iterator> 00634 equal_range(const key_type& __k) const; 00635 00636 protected: 00637 // Bucket index computation helpers. 00638 size_type 00639 _M_bucket_index(__node_type* __n) const noexcept 00640 { return __hash_code_base::_M_bucket_index(__n, _M_bucket_count); } 00641 00642 size_type 00643 _M_bucket_index(const key_type& __k, __hash_code __c) const 00644 { return __hash_code_base::_M_bucket_index(__k, __c, _M_bucket_count); } 00645 00646 // Find and insert helper functions and types 00647 // Find the node before the one matching the criteria. 00648 __node_base* 00649 _M_find_before_node(size_type, const key_type&, __hash_code) const; 00650 00651 __node_type* 00652 _M_find_node(size_type __bkt, const key_type& __key, 00653 __hash_code __c) const 00654 { 00655 __node_base* __before_n = _M_find_before_node(__bkt, __key, __c); 00656 if (__before_n) 00657 return static_cast<__node_type*>(__before_n->_M_nxt); 00658 return nullptr; 00659 } 00660 00661 // Insert a node at the beginning of a bucket. 00662 void 00663 _M_insert_bucket_begin(size_type, __node_type*); 00664 00665 // Remove the bucket first node 00666 void 00667 _M_remove_bucket_begin(size_type __bkt, __node_type* __next_n, 00668 size_type __next_bkt); 00669 00670 // Get the node before __n in the bucket __bkt 00671 __node_base* 00672 _M_get_previous_node(size_type __bkt, __node_base* __n); 00673 00674 // Insert node with hash code __code, in bucket bkt if no rehash (assumes 00675 // no element with its key already present). Take ownership of the node, 00676 // deallocate it on exception. 00677 iterator 00678 _M_insert_unique_node(size_type __bkt, __hash_code __code, 00679 __node_type* __n, size_type __n_elt = 1); 00680 00681 // Insert node with hash code __code. Take ownership of the node, 00682 // deallocate it on exception. 00683 iterator 00684 _M_insert_multi_node(__node_type* __hint, 00685 __hash_code __code, __node_type* __n); 00686 00687 template<typename... _Args> 00688 std::pair<iterator, bool> 00689 _M_emplace(std::true_type, _Args&&... __args); 00690 00691 template<typename... _Args> 00692 iterator 00693 _M_emplace(std::false_type __uk, _Args&&... __args) 00694 { return _M_emplace(cend(), __uk, std::forward<_Args>(__args)...); } 00695 00696 // Emplace with hint, useless when keys are unique. 00697 template<typename... _Args> 00698 iterator 00699 _M_emplace(const_iterator, std::true_type __uk, _Args&&... __args) 00700 { return _M_emplace(__uk, std::forward<_Args>(__args)...).first; } 00701 00702 template<typename... _Args> 00703 iterator 00704 _M_emplace(const_iterator, std::false_type, _Args&&... __args); 00705 00706 template<typename _Arg, typename _NodeGenerator> 00707 std::pair<iterator, bool> 00708 _M_insert(_Arg&&, const _NodeGenerator&, true_type, size_type = 1); 00709 00710 template<typename _Arg, typename _NodeGenerator> 00711 iterator 00712 _M_insert(_Arg&& __arg, const _NodeGenerator& __node_gen, 00713 false_type __uk) 00714 { 00715 return _M_insert(cend(), std::forward<_Arg>(__arg), __node_gen, 00716 __uk); 00717 } 00718 00719 // Insert with hint, not used when keys are unique. 00720 template<typename _Arg, typename _NodeGenerator> 00721 iterator 00722 _M_insert(const_iterator, _Arg&& __arg, 00723 const _NodeGenerator& __node_gen, true_type __uk) 00724 { 00725 return 00726 _M_insert(std::forward<_Arg>(__arg), __node_gen, __uk).first; 00727 } 00728 00729 // Insert with hint when keys are not unique. 00730 template<typename _Arg, typename _NodeGenerator> 00731 iterator 00732 _M_insert(const_iterator, _Arg&&, 00733 const _NodeGenerator&, false_type); 00734 00735 size_type 00736 _M_erase(std::true_type, const key_type&); 00737 00738 size_type 00739 _M_erase(std::false_type, const key_type&); 00740 00741 iterator 00742 _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n); 00743 00744 public: 00745 // Emplace 00746 template<typename... _Args> 00747 __ireturn_type 00748 emplace(_Args&&... __args) 00749 { return _M_emplace(__unique_keys(), std::forward<_Args>(__args)...); } 00750 00751 template<typename... _Args> 00752 iterator 00753 emplace_hint(const_iterator __hint, _Args&&... __args) 00754 { 00755 return _M_emplace(__hint, __unique_keys(), 00756 std::forward<_Args>(__args)...); 00757 } 00758 00759 // Insert member functions via inheritance. 00760 00761 // Erase 00762 iterator 00763 erase(const_iterator); 00764 00765 // LWG 2059. 00766 iterator 00767 erase(iterator __it) 00768 { return erase(const_iterator(__it)); } 00769 00770 size_type 00771 erase(const key_type& __k) 00772 { return _M_erase(__unique_keys(), __k); } 00773 00774 iterator 00775 erase(const_iterator, const_iterator); 00776 00777 void 00778 clear() noexcept; 00779 00780 // Set number of buckets to be appropriate for container of n element. 00781 void rehash(size_type __n); 00782 00783 // DR 1189. 00784 // reserve, if present, comes from _Rehash_base. 00785 00786 #if __cplusplus > 201402L 00787 /// Re-insert an extracted node into a container with unique keys. 00788 insert_return_type 00789 _M_reinsert_node(node_type&& __nh) 00790 { 00791 insert_return_type __ret; 00792 if (__nh.empty()) 00793 __ret.position = end(); 00794 else 00795 { 00796 __glibcxx_assert(get_allocator() == __nh.get_allocator()); 00797 00798 const key_type& __k = __nh._M_key(); 00799 __hash_code __code = this->_M_hash_code(__k); 00800 size_type __bkt = _M_bucket_index(__k, __code); 00801 if (__node_type* __n = _M_find_node(__bkt, __k, __code)) 00802 { 00803 __ret.node = std::move(__nh); 00804 __ret.position = iterator(__n); 00805 __ret.inserted = false; 00806 } 00807 else 00808 { 00809 __ret.position 00810 = _M_insert_unique_node(__bkt, __code, __nh._M_ptr); 00811 __nh._M_ptr = nullptr; 00812 __ret.inserted = true; 00813 } 00814 } 00815 return __ret; 00816 } 00817 00818 /// Re-insert an extracted node into a container with equivalent keys. 00819 iterator 00820 _M_reinsert_node_multi(const_iterator __hint, node_type&& __nh) 00821 { 00822 iterator __ret; 00823 if (__nh.empty()) 00824 __ret = end(); 00825 else 00826 { 00827 __glibcxx_assert(get_allocator() == __nh.get_allocator()); 00828 00829 auto __code = this->_M_hash_code(__nh._M_key()); 00830 auto __node = std::exchange(__nh._M_ptr, nullptr); 00831 // FIXME: this deallocates the node on exception. 00832 __ret = _M_insert_multi_node(__hint._M_cur, __code, __node); 00833 } 00834 return __ret; 00835 } 00836 00837 /// Extract a node. 00838 node_type 00839 extract(const_iterator __pos) 00840 { 00841 __node_type* __n = __pos._M_cur; 00842 size_t __bkt = _M_bucket_index(__n); 00843 00844 // Look for previous node to unlink it from the erased one, this 00845 // is why we need buckets to contain the before begin to make 00846 // this search fast. 00847 __node_base* __prev_n = _M_get_previous_node(__bkt, __n); 00848 00849 if (__prev_n == _M_buckets[__bkt]) 00850 _M_remove_bucket_begin(__bkt, __n->_M_next(), 00851 __n->_M_nxt ? _M_bucket_index(__n->_M_next()) : 0); 00852 else if (__n->_M_nxt) 00853 { 00854 size_type __next_bkt = _M_bucket_index(__n->_M_next()); 00855 if (__next_bkt != __bkt) 00856 _M_buckets[__next_bkt] = __prev_n; 00857 } 00858 00859 __prev_n->_M_nxt = __n->_M_nxt; 00860 __n->_M_nxt = nullptr; 00861 --_M_element_count; 00862 return { __n, this->_M_node_allocator() }; 00863 } 00864 00865 /// Extract a node. 00866 node_type 00867 extract(const _Key& __k) 00868 { 00869 node_type __nh; 00870 auto __pos = find(__k); 00871 if (__pos != end()) 00872 __nh = extract(const_iterator(__pos)); 00873 return __nh; 00874 } 00875 00876 /// Merge from a compatible container into one with unique keys. 00877 template<typename _Compatible_Hashtable> 00878 void 00879 _M_merge_unique(_Compatible_Hashtable& __src) noexcept 00880 { 00881 static_assert(is_same_v<typename _Compatible_Hashtable::node_type, 00882 node_type>, "Node types are compatible"); 00883 __glibcxx_assert(get_allocator() == __src.get_allocator()); 00884 00885 auto __n_elt = __src.size(); 00886 for (auto __i = __src.begin(), __end = __src.end(); __i != __end;) 00887 { 00888 auto __pos = __i++; 00889 const key_type& __k = this->_M_extract()(__pos._M_cur->_M_v()); 00890 __hash_code __code = this->_M_hash_code(__k); 00891 size_type __bkt = _M_bucket_index(__k, __code); 00892 if (_M_find_node(__bkt, __k, __code) == nullptr) 00893 { 00894 auto __nh = __src.extract(__pos); 00895 _M_insert_unique_node(__bkt, __code, __nh._M_ptr, __n_elt); 00896 __nh._M_ptr = nullptr; 00897 __n_elt = 1; 00898 } 00899 else if (__n_elt != 1) 00900 --__n_elt; 00901 } 00902 } 00903 00904 /// Merge from a compatible container into one with equivalent keys. 00905 template<typename _Compatible_Hashtable> 00906 void 00907 _M_merge_multi(_Compatible_Hashtable& __src) noexcept 00908 { 00909 static_assert(is_same_v<typename _Compatible_Hashtable::node_type, 00910 node_type>, "Node types are compatible"); 00911 __glibcxx_assert(get_allocator() == __src.get_allocator()); 00912 00913 this->reserve(size() + __src.size()); 00914 for (auto __i = __src.begin(), __end = __src.end(); __i != __end;) 00915 _M_reinsert_node_multi(cend(), __src.extract(__i++)); 00916 } 00917 #endif // C++17 00918 00919 private: 00920 // Helper rehash method used when keys are unique. 00921 void _M_rehash_aux(size_type __n, std::true_type); 00922 00923 // Helper rehash method used when keys can be non-unique. 00924 void _M_rehash_aux(size_type __n, std::false_type); 00925 00926 // Unconditionally change size of bucket array to n, restore 00927 // hash policy state to __state on exception. 00928 void _M_rehash(size_type __n, const __rehash_state& __state); 00929 }; 00930 00931 00932 // Definitions of class template _Hashtable's out-of-line member functions. 00933 template<typename _Key, typename _Value, 00934 typename _Alloc, typename _ExtractKey, typename _Equal, 00935 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 00936 typename _Traits> 00937 auto 00938 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 00939 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 00940 _M_bucket_begin(size_type __bkt) const 00941 -> __node_type* 00942 { 00943 __node_base* __n = _M_buckets[__bkt]; 00944 return __n ? static_cast<__node_type*>(__n->_M_nxt) : nullptr; 00945 } 00946 00947 template<typename _Key, typename _Value, 00948 typename _Alloc, typename _ExtractKey, typename _Equal, 00949 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 00950 typename _Traits> 00951 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 00952 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 00953 _Hashtable(size_type __bucket_hint, 00954 const _H1& __h1, const _H2& __h2, const _Hash& __h, 00955 const _Equal& __eq, const _ExtractKey& __exk, 00956 const allocator_type& __a) 00957 : _Hashtable(__h1, __h2, __h, __eq, __exk, __a) 00958 { 00959 auto __bkt = _M_rehash_policy._M_next_bkt(__bucket_hint); 00960 if (__bkt > _M_bucket_count) 00961 { 00962 _M_buckets = _M_allocate_buckets(__bkt); 00963 _M_bucket_count = __bkt; 00964 } 00965 } 00966 00967 template<typename _Key, typename _Value, 00968 typename _Alloc, typename _ExtractKey, typename _Equal, 00969 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 00970 typename _Traits> 00971 template<typename _InputIterator> 00972 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 00973 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 00974 _Hashtable(_InputIterator __f, _InputIterator __l, 00975 size_type __bucket_hint, 00976 const _H1& __h1, const _H2& __h2, const _Hash& __h, 00977 const _Equal& __eq, const _ExtractKey& __exk, 00978 const allocator_type& __a) 00979 : _Hashtable(__h1, __h2, __h, __eq, __exk, __a) 00980 { 00981 auto __nb_elems = __detail::__distance_fw(__f, __l); 00982 auto __bkt_count = 00983 _M_rehash_policy._M_next_bkt( 00984 std::max(_M_rehash_policy._M_bkt_for_elements(__nb_elems), 00985 __bucket_hint)); 00986 00987 if (__bkt_count > _M_bucket_count) 00988 { 00989 _M_buckets = _M_allocate_buckets(__bkt_count); 00990 _M_bucket_count = __bkt_count; 00991 } 00992 00993 for (; __f != __l; ++__f) 00994 this->insert(*__f); 00995 } 00996 00997 template<typename _Key, typename _Value, 00998 typename _Alloc, typename _ExtractKey, typename _Equal, 00999 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01000 typename _Traits> 01001 auto 01002 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01003 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01004 operator=(const _Hashtable& __ht) 01005 -> _Hashtable& 01006 { 01007 if (&__ht == this) 01008 return *this; 01009 01010 if (__node_alloc_traits::_S_propagate_on_copy_assign()) 01011 { 01012 auto& __this_alloc = this->_M_node_allocator(); 01013 auto& __that_alloc = __ht._M_node_allocator(); 01014 if (!__node_alloc_traits::_S_always_equal() 01015 && __this_alloc != __that_alloc) 01016 { 01017 // Replacement allocator cannot free existing storage. 01018 this->_M_deallocate_nodes(_M_begin()); 01019 _M_before_begin._M_nxt = nullptr; 01020 _M_deallocate_buckets(); 01021 _M_buckets = nullptr; 01022 std::__alloc_on_copy(__this_alloc, __that_alloc); 01023 __hashtable_base::operator=(__ht); 01024 _M_bucket_count = __ht._M_bucket_count; 01025 _M_element_count = __ht._M_element_count; 01026 _M_rehash_policy = __ht._M_rehash_policy; 01027 __try 01028 { 01029 _M_assign(__ht, 01030 [this](const __node_type* __n) 01031 { return this->_M_allocate_node(__n->_M_v()); }); 01032 } 01033 __catch(...) 01034 { 01035 // _M_assign took care of deallocating all memory. Now we 01036 // must make sure this instance remains in a usable state. 01037 _M_reset(); 01038 __throw_exception_again; 01039 } 01040 return *this; 01041 } 01042 std::__alloc_on_copy(__this_alloc, __that_alloc); 01043 } 01044 01045 // Reuse allocated buckets and nodes. 01046 _M_assign_elements(__ht, 01047 [](const __reuse_or_alloc_node_type& __roan, const __node_type* __n) 01048 { return __roan(__n->_M_v()); }); 01049 return *this; 01050 } 01051 01052 template<typename _Key, typename _Value, 01053 typename _Alloc, typename _ExtractKey, typename _Equal, 01054 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01055 typename _Traits> 01056 template<typename _Ht, typename _NodeGenerator> 01057 void 01058 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01059 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01060 _M_assign_elements(_Ht&& __ht, const _NodeGenerator& __node_gen) 01061 { 01062 __bucket_type* __former_buckets = nullptr; 01063 std::size_t __former_bucket_count = _M_bucket_count; 01064 const __rehash_state& __former_state = _M_rehash_policy._M_state(); 01065 01066 if (_M_bucket_count != __ht._M_bucket_count) 01067 { 01068 __former_buckets = _M_buckets; 01069 _M_buckets = _M_allocate_buckets(__ht._M_bucket_count); 01070 _M_bucket_count = __ht._M_bucket_count; 01071 } 01072 else 01073 __builtin_memset(_M_buckets, 0, 01074 _M_bucket_count * sizeof(__bucket_type)); 01075 01076 __try 01077 { 01078 __hashtable_base::operator=(std::forward<_Ht>(__ht)); 01079 _M_element_count = __ht._M_element_count; 01080 _M_rehash_policy = __ht._M_rehash_policy; 01081 __reuse_or_alloc_node_type __roan(_M_begin(), *this); 01082 _M_before_begin._M_nxt = nullptr; 01083 _M_assign(__ht, 01084 [&__node_gen, &__roan](__node_type* __n) 01085 { return __node_gen(__roan, __n); }); 01086 if (__former_buckets) 01087 _M_deallocate_buckets(__former_buckets, __former_bucket_count); 01088 } 01089 __catch(...) 01090 { 01091 if (__former_buckets) 01092 { 01093 // Restore previous buckets. 01094 _M_deallocate_buckets(); 01095 _M_rehash_policy._M_reset(__former_state); 01096 _M_buckets = __former_buckets; 01097 _M_bucket_count = __former_bucket_count; 01098 } 01099 __builtin_memset(_M_buckets, 0, 01100 _M_bucket_count * sizeof(__bucket_type)); 01101 __throw_exception_again; 01102 } 01103 } 01104 01105 template<typename _Key, typename _Value, 01106 typename _Alloc, typename _ExtractKey, typename _Equal, 01107 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01108 typename _Traits> 01109 template<typename _NodeGenerator> 01110 void 01111 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01112 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01113 _M_assign(const _Hashtable& __ht, const _NodeGenerator& __node_gen) 01114 { 01115 __bucket_type* __buckets = nullptr; 01116 if (!_M_buckets) 01117 _M_buckets = __buckets = _M_allocate_buckets(_M_bucket_count); 01118 01119 __try 01120 { 01121 if (!__ht._M_before_begin._M_nxt) 01122 return; 01123 01124 // First deal with the special first node pointed to by 01125 // _M_before_begin. 01126 __node_type* __ht_n = __ht._M_begin(); 01127 __node_type* __this_n = __node_gen(__ht_n); 01128 this->_M_copy_code(__this_n, __ht_n); 01129 _M_before_begin._M_nxt = __this_n; 01130 _M_buckets[_M_bucket_index(__this_n)] = &_M_before_begin; 01131 01132 // Then deal with other nodes. 01133 __node_base* __prev_n = __this_n; 01134 for (__ht_n = __ht_n->_M_next(); __ht_n; __ht_n = __ht_n->_M_next()) 01135 { 01136 __this_n = __node_gen(__ht_n); 01137 __prev_n->_M_nxt = __this_n; 01138 this->_M_copy_code(__this_n, __ht_n); 01139 size_type __bkt = _M_bucket_index(__this_n); 01140 if (!_M_buckets[__bkt]) 01141 _M_buckets[__bkt] = __prev_n; 01142 __prev_n = __this_n; 01143 } 01144 } 01145 __catch(...) 01146 { 01147 clear(); 01148 if (__buckets) 01149 _M_deallocate_buckets(); 01150 __throw_exception_again; 01151 } 01152 } 01153 01154 template<typename _Key, typename _Value, 01155 typename _Alloc, typename _ExtractKey, typename _Equal, 01156 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01157 typename _Traits> 01158 void 01159 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01160 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01161 _M_reset() noexcept 01162 { 01163 _M_rehash_policy._M_reset(); 01164 _M_bucket_count = 1; 01165 _M_single_bucket = nullptr; 01166 _M_buckets = &_M_single_bucket; 01167 _M_before_begin._M_nxt = nullptr; 01168 _M_element_count = 0; 01169 } 01170 01171 template<typename _Key, typename _Value, 01172 typename _Alloc, typename _ExtractKey, typename _Equal, 01173 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01174 typename _Traits> 01175 void 01176 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01177 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01178 _M_move_assign(_Hashtable&& __ht, std::true_type) 01179 { 01180 this->_M_deallocate_nodes(_M_begin()); 01181 _M_deallocate_buckets(); 01182 __hashtable_base::operator=(std::move(__ht)); 01183 _M_rehash_policy = __ht._M_rehash_policy; 01184 if (!__ht._M_uses_single_bucket()) 01185 _M_buckets = __ht._M_buckets; 01186 else 01187 { 01188 _M_buckets = &_M_single_bucket; 01189 _M_single_bucket = __ht._M_single_bucket; 01190 } 01191 _M_bucket_count = __ht._M_bucket_count; 01192 _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt; 01193 _M_element_count = __ht._M_element_count; 01194 std::__alloc_on_move(this->_M_node_allocator(), __ht._M_node_allocator()); 01195 01196 // Fix buckets containing the _M_before_begin pointers that can't be 01197 // moved. 01198 if (_M_begin()) 01199 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; 01200 __ht._M_reset(); 01201 } 01202 01203 template<typename _Key, typename _Value, 01204 typename _Alloc, typename _ExtractKey, typename _Equal, 01205 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01206 typename _Traits> 01207 void 01208 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01209 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01210 _M_move_assign(_Hashtable&& __ht, std::false_type) 01211 { 01212 if (__ht._M_node_allocator() == this->_M_node_allocator()) 01213 _M_move_assign(std::move(__ht), std::true_type()); 01214 else 01215 { 01216 // Can't move memory, move elements then. 01217 _M_assign_elements(std::move(__ht), 01218 [](const __reuse_or_alloc_node_type& __roan, __node_type* __n) 01219 { return __roan(std::move_if_noexcept(__n->_M_v())); }); 01220 __ht.clear(); 01221 } 01222 } 01223 01224 template<typename _Key, typename _Value, 01225 typename _Alloc, typename _ExtractKey, typename _Equal, 01226 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01227 typename _Traits> 01228 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01229 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01230 _Hashtable(const _Hashtable& __ht) 01231 : __hashtable_base(__ht), 01232 __map_base(__ht), 01233 __rehash_base(__ht), 01234 __hashtable_alloc( 01235 __node_alloc_traits::_S_select_on_copy(__ht._M_node_allocator())), 01236 _M_buckets(nullptr), 01237 _M_bucket_count(__ht._M_bucket_count), 01238 _M_element_count(__ht._M_element_count), 01239 _M_rehash_policy(__ht._M_rehash_policy) 01240 { 01241 _M_assign(__ht, 01242 [this](const __node_type* __n) 01243 { return this->_M_allocate_node(__n->_M_v()); }); 01244 } 01245 01246 template<typename _Key, typename _Value, 01247 typename _Alloc, typename _ExtractKey, typename _Equal, 01248 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01249 typename _Traits> 01250 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01251 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01252 _Hashtable(_Hashtable&& __ht) noexcept 01253 : __hashtable_base(__ht), 01254 __map_base(__ht), 01255 __rehash_base(__ht), 01256 __hashtable_alloc(std::move(__ht._M_base_alloc())), 01257 _M_buckets(__ht._M_buckets), 01258 _M_bucket_count(__ht._M_bucket_count), 01259 _M_before_begin(__ht._M_before_begin._M_nxt), 01260 _M_element_count(__ht._M_element_count), 01261 _M_rehash_policy(__ht._M_rehash_policy) 01262 { 01263 // Update, if necessary, buckets if __ht is using its single bucket. 01264 if (__ht._M_uses_single_bucket()) 01265 { 01266 _M_buckets = &_M_single_bucket; 01267 _M_single_bucket = __ht._M_single_bucket; 01268 } 01269 01270 // Update, if necessary, bucket pointing to before begin that hasn't 01271 // moved. 01272 if (_M_begin()) 01273 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; 01274 01275 __ht._M_reset(); 01276 } 01277 01278 template<typename _Key, typename _Value, 01279 typename _Alloc, typename _ExtractKey, typename _Equal, 01280 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01281 typename _Traits> 01282 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01283 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01284 _Hashtable(const _Hashtable& __ht, const allocator_type& __a) 01285 : __hashtable_base(__ht), 01286 __map_base(__ht), 01287 __rehash_base(__ht), 01288 __hashtable_alloc(__node_alloc_type(__a)), 01289 _M_buckets(), 01290 _M_bucket_count(__ht._M_bucket_count), 01291 _M_element_count(__ht._M_element_count), 01292 _M_rehash_policy(__ht._M_rehash_policy) 01293 { 01294 _M_assign(__ht, 01295 [this](const __node_type* __n) 01296 { return this->_M_allocate_node(__n->_M_v()); }); 01297 } 01298 01299 template<typename _Key, typename _Value, 01300 typename _Alloc, typename _ExtractKey, typename _Equal, 01301 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01302 typename _Traits> 01303 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01304 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01305 _Hashtable(_Hashtable&& __ht, const allocator_type& __a) 01306 : __hashtable_base(__ht), 01307 __map_base(__ht), 01308 __rehash_base(__ht), 01309 __hashtable_alloc(__node_alloc_type(__a)), 01310 _M_buckets(nullptr), 01311 _M_bucket_count(__ht._M_bucket_count), 01312 _M_element_count(__ht._M_element_count), 01313 _M_rehash_policy(__ht._M_rehash_policy) 01314 { 01315 if (__ht._M_node_allocator() == this->_M_node_allocator()) 01316 { 01317 if (__ht._M_uses_single_bucket()) 01318 { 01319 _M_buckets = &_M_single_bucket; 01320 _M_single_bucket = __ht._M_single_bucket; 01321 } 01322 else 01323 _M_buckets = __ht._M_buckets; 01324 01325 _M_before_begin._M_nxt = __ht._M_before_begin._M_nxt; 01326 // Update, if necessary, bucket pointing to before begin that hasn't 01327 // moved. 01328 if (_M_begin()) 01329 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; 01330 __ht._M_reset(); 01331 } 01332 else 01333 { 01334 _M_assign(__ht, 01335 [this](__node_type* __n) 01336 { 01337 return this->_M_allocate_node( 01338 std::move_if_noexcept(__n->_M_v())); 01339 }); 01340 __ht.clear(); 01341 } 01342 } 01343 01344 template<typename _Key, typename _Value, 01345 typename _Alloc, typename _ExtractKey, typename _Equal, 01346 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01347 typename _Traits> 01348 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01349 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01350 ~_Hashtable() noexcept 01351 { 01352 clear(); 01353 _M_deallocate_buckets(); 01354 } 01355 01356 template<typename _Key, typename _Value, 01357 typename _Alloc, typename _ExtractKey, typename _Equal, 01358 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01359 typename _Traits> 01360 void 01361 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01362 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01363 swap(_Hashtable& __x) 01364 noexcept(__and_<__is_nothrow_swappable<_H1>, 01365 __is_nothrow_swappable<_Equal>>::value) 01366 { 01367 // The only base class with member variables is hash_code_base. 01368 // We define _Hash_code_base::_M_swap because different 01369 // specializations have different members. 01370 this->_M_swap(__x); 01371 01372 std::__alloc_on_swap(this->_M_node_allocator(), __x._M_node_allocator()); 01373 std::swap(_M_rehash_policy, __x._M_rehash_policy); 01374 01375 // Deal properly with potentially moved instances. 01376 if (this->_M_uses_single_bucket()) 01377 { 01378 if (!__x._M_uses_single_bucket()) 01379 { 01380 _M_buckets = __x._M_buckets; 01381 __x._M_buckets = &__x._M_single_bucket; 01382 } 01383 } 01384 else if (__x._M_uses_single_bucket()) 01385 { 01386 __x._M_buckets = _M_buckets; 01387 _M_buckets = &_M_single_bucket; 01388 } 01389 else 01390 std::swap(_M_buckets, __x._M_buckets); 01391 01392 std::swap(_M_bucket_count, __x._M_bucket_count); 01393 std::swap(_M_before_begin._M_nxt, __x._M_before_begin._M_nxt); 01394 std::swap(_M_element_count, __x._M_element_count); 01395 std::swap(_M_single_bucket, __x._M_single_bucket); 01396 01397 // Fix buckets containing the _M_before_begin pointers that can't be 01398 // swapped. 01399 if (_M_begin()) 01400 _M_buckets[_M_bucket_index(_M_begin())] = &_M_before_begin; 01401 01402 if (__x._M_begin()) 01403 __x._M_buckets[__x._M_bucket_index(__x._M_begin())] 01404 = &__x._M_before_begin; 01405 } 01406 01407 template<typename _Key, typename _Value, 01408 typename _Alloc, typename _ExtractKey, typename _Equal, 01409 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01410 typename _Traits> 01411 auto 01412 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01413 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01414 find(const key_type& __k) 01415 -> iterator 01416 { 01417 __hash_code __code = this->_M_hash_code(__k); 01418 std::size_t __n = _M_bucket_index(__k, __code); 01419 __node_type* __p = _M_find_node(__n, __k, __code); 01420 return __p ? iterator(__p) : end(); 01421 } 01422 01423 template<typename _Key, typename _Value, 01424 typename _Alloc, typename _ExtractKey, typename _Equal, 01425 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01426 typename _Traits> 01427 auto 01428 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01429 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01430 find(const key_type& __k) const 01431 -> const_iterator 01432 { 01433 __hash_code __code = this->_M_hash_code(__k); 01434 std::size_t __n = _M_bucket_index(__k, __code); 01435 __node_type* __p = _M_find_node(__n, __k, __code); 01436 return __p ? const_iterator(__p) : end(); 01437 } 01438 01439 template<typename _Key, typename _Value, 01440 typename _Alloc, typename _ExtractKey, typename _Equal, 01441 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01442 typename _Traits> 01443 auto 01444 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01445 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01446 count(const key_type& __k) const 01447 -> size_type 01448 { 01449 __hash_code __code = this->_M_hash_code(__k); 01450 std::size_t __n = _M_bucket_index(__k, __code); 01451 __node_type* __p = _M_bucket_begin(__n); 01452 if (!__p) 01453 return 0; 01454 01455 std::size_t __result = 0; 01456 for (;; __p = __p->_M_next()) 01457 { 01458 if (this->_M_equals(__k, __code, __p)) 01459 ++__result; 01460 else if (__result) 01461 // All equivalent values are next to each other, if we 01462 // found a non-equivalent value after an equivalent one it 01463 // means that we won't find any new equivalent value. 01464 break; 01465 if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n) 01466 break; 01467 } 01468 return __result; 01469 } 01470 01471 template<typename _Key, typename _Value, 01472 typename _Alloc, typename _ExtractKey, typename _Equal, 01473 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01474 typename _Traits> 01475 auto 01476 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01477 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01478 equal_range(const key_type& __k) 01479 -> pair<iterator, iterator> 01480 { 01481 __hash_code __code = this->_M_hash_code(__k); 01482 std::size_t __n = _M_bucket_index(__k, __code); 01483 __node_type* __p = _M_find_node(__n, __k, __code); 01484 01485 if (__p) 01486 { 01487 __node_type* __p1 = __p->_M_next(); 01488 while (__p1 && _M_bucket_index(__p1) == __n 01489 && this->_M_equals(__k, __code, __p1)) 01490 __p1 = __p1->_M_next(); 01491 01492 return std::make_pair(iterator(__p), iterator(__p1)); 01493 } 01494 else 01495 return std::make_pair(end(), end()); 01496 } 01497 01498 template<typename _Key, typename _Value, 01499 typename _Alloc, typename _ExtractKey, typename _Equal, 01500 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01501 typename _Traits> 01502 auto 01503 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01504 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01505 equal_range(const key_type& __k) const 01506 -> pair<const_iterator, const_iterator> 01507 { 01508 __hash_code __code = this->_M_hash_code(__k); 01509 std::size_t __n = _M_bucket_index(__k, __code); 01510 __node_type* __p = _M_find_node(__n, __k, __code); 01511 01512 if (__p) 01513 { 01514 __node_type* __p1 = __p->_M_next(); 01515 while (__p1 && _M_bucket_index(__p1) == __n 01516 && this->_M_equals(__k, __code, __p1)) 01517 __p1 = __p1->_M_next(); 01518 01519 return std::make_pair(const_iterator(__p), const_iterator(__p1)); 01520 } 01521 else 01522 return std::make_pair(end(), end()); 01523 } 01524 01525 // Find the node whose key compares equal to k in the bucket n. 01526 // Return nullptr if no node is found. 01527 template<typename _Key, typename _Value, 01528 typename _Alloc, typename _ExtractKey, typename _Equal, 01529 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01530 typename _Traits> 01531 auto 01532 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01533 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01534 _M_find_before_node(size_type __n, const key_type& __k, 01535 __hash_code __code) const 01536 -> __node_base* 01537 { 01538 __node_base* __prev_p = _M_buckets[__n]; 01539 if (!__prev_p) 01540 return nullptr; 01541 01542 for (__node_type* __p = static_cast<__node_type*>(__prev_p->_M_nxt);; 01543 __p = __p->_M_next()) 01544 { 01545 if (this->_M_equals(__k, __code, __p)) 01546 return __prev_p; 01547 01548 if (!__p->_M_nxt || _M_bucket_index(__p->_M_next()) != __n) 01549 break; 01550 __prev_p = __p; 01551 } 01552 return nullptr; 01553 } 01554 01555 template<typename _Key, typename _Value, 01556 typename _Alloc, typename _ExtractKey, typename _Equal, 01557 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01558 typename _Traits> 01559 void 01560 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01561 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01562 _M_insert_bucket_begin(size_type __bkt, __node_type* __node) 01563 { 01564 if (_M_buckets[__bkt]) 01565 { 01566 // Bucket is not empty, we just need to insert the new node 01567 // after the bucket before begin. 01568 __node->_M_nxt = _M_buckets[__bkt]->_M_nxt; 01569 _M_buckets[__bkt]->_M_nxt = __node; 01570 } 01571 else 01572 { 01573 // The bucket is empty, the new node is inserted at the 01574 // beginning of the singly-linked list and the bucket will 01575 // contain _M_before_begin pointer. 01576 __node->_M_nxt = _M_before_begin._M_nxt; 01577 _M_before_begin._M_nxt = __node; 01578 if (__node->_M_nxt) 01579 // We must update former begin bucket that is pointing to 01580 // _M_before_begin. 01581 _M_buckets[_M_bucket_index(__node->_M_next())] = __node; 01582 _M_buckets[__bkt] = &_M_before_begin; 01583 } 01584 } 01585 01586 template<typename _Key, typename _Value, 01587 typename _Alloc, typename _ExtractKey, typename _Equal, 01588 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01589 typename _Traits> 01590 void 01591 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01592 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01593 _M_remove_bucket_begin(size_type __bkt, __node_type* __next, 01594 size_type __next_bkt) 01595 { 01596 if (!__next || __next_bkt != __bkt) 01597 { 01598 // Bucket is now empty 01599 // First update next bucket if any 01600 if (__next) 01601 _M_buckets[__next_bkt] = _M_buckets[__bkt]; 01602 01603 // Second update before begin node if necessary 01604 if (&_M_before_begin == _M_buckets[__bkt]) 01605 _M_before_begin._M_nxt = __next; 01606 _M_buckets[__bkt] = nullptr; 01607 } 01608 } 01609 01610 template<typename _Key, typename _Value, 01611 typename _Alloc, typename _ExtractKey, typename _Equal, 01612 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01613 typename _Traits> 01614 auto 01615 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01616 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01617 _M_get_previous_node(size_type __bkt, __node_base* __n) 01618 -> __node_base* 01619 { 01620 __node_base* __prev_n = _M_buckets[__bkt]; 01621 while (__prev_n->_M_nxt != __n) 01622 __prev_n = __prev_n->_M_nxt; 01623 return __prev_n; 01624 } 01625 01626 template<typename _Key, typename _Value, 01627 typename _Alloc, typename _ExtractKey, typename _Equal, 01628 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01629 typename _Traits> 01630 template<typename... _Args> 01631 auto 01632 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01633 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01634 _M_emplace(std::true_type, _Args&&... __args) 01635 -> pair<iterator, bool> 01636 { 01637 // First build the node to get access to the hash code 01638 __node_type* __node = this->_M_allocate_node(std::forward<_Args>(__args)...); 01639 const key_type& __k = this->_M_extract()(__node->_M_v()); 01640 __hash_code __code; 01641 __try 01642 { 01643 __code = this->_M_hash_code(__k); 01644 } 01645 __catch(...) 01646 { 01647 this->_M_deallocate_node(__node); 01648 __throw_exception_again; 01649 } 01650 01651 size_type __bkt = _M_bucket_index(__k, __code); 01652 if (__node_type* __p = _M_find_node(__bkt, __k, __code)) 01653 { 01654 // There is already an equivalent node, no insertion 01655 this->_M_deallocate_node(__node); 01656 return std::make_pair(iterator(__p), false); 01657 } 01658 01659 // Insert the node 01660 return std::make_pair(_M_insert_unique_node(__bkt, __code, __node), 01661 true); 01662 } 01663 01664 template<typename _Key, typename _Value, 01665 typename _Alloc, typename _ExtractKey, typename _Equal, 01666 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01667 typename _Traits> 01668 template<typename... _Args> 01669 auto 01670 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01671 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01672 _M_emplace(const_iterator __hint, std::false_type, _Args&&... __args) 01673 -> iterator 01674 { 01675 // First build the node to get its hash code. 01676 __node_type* __node = 01677 this->_M_allocate_node(std::forward<_Args>(__args)...); 01678 01679 __hash_code __code; 01680 __try 01681 { 01682 __code = this->_M_hash_code(this->_M_extract()(__node->_M_v())); 01683 } 01684 __catch(...) 01685 { 01686 this->_M_deallocate_node(__node); 01687 __throw_exception_again; 01688 } 01689 01690 return _M_insert_multi_node(__hint._M_cur, __code, __node); 01691 } 01692 01693 template<typename _Key, typename _Value, 01694 typename _Alloc, typename _ExtractKey, typename _Equal, 01695 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01696 typename _Traits> 01697 auto 01698 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01699 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01700 _M_insert_unique_node(size_type __bkt, __hash_code __code, 01701 __node_type* __node, size_type __n_elt) 01702 -> iterator 01703 { 01704 const __rehash_state& __saved_state = _M_rehash_policy._M_state(); 01705 std::pair<bool, std::size_t> __do_rehash 01706 = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 01707 __n_elt); 01708 01709 __try 01710 { 01711 if (__do_rehash.first) 01712 { 01713 _M_rehash(__do_rehash.second, __saved_state); 01714 __bkt = _M_bucket_index(this->_M_extract()(__node->_M_v()), __code); 01715 } 01716 01717 this->_M_store_code(__node, __code); 01718 01719 // Always insert at the beginning of the bucket. 01720 _M_insert_bucket_begin(__bkt, __node); 01721 ++_M_element_count; 01722 return iterator(__node); 01723 } 01724 __catch(...) 01725 { 01726 this->_M_deallocate_node(__node); 01727 __throw_exception_again; 01728 } 01729 } 01730 01731 // Insert node, in bucket bkt if no rehash (assumes no element with its key 01732 // already present). Take ownership of the node, deallocate it on exception. 01733 template<typename _Key, typename _Value, 01734 typename _Alloc, typename _ExtractKey, typename _Equal, 01735 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01736 typename _Traits> 01737 auto 01738 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01739 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01740 _M_insert_multi_node(__node_type* __hint, __hash_code __code, 01741 __node_type* __node) 01742 -> iterator 01743 { 01744 const __rehash_state& __saved_state = _M_rehash_policy._M_state(); 01745 std::pair<bool, std::size_t> __do_rehash 01746 = _M_rehash_policy._M_need_rehash(_M_bucket_count, _M_element_count, 1); 01747 01748 __try 01749 { 01750 if (__do_rehash.first) 01751 _M_rehash(__do_rehash.second, __saved_state); 01752 01753 this->_M_store_code(__node, __code); 01754 const key_type& __k = this->_M_extract()(__node->_M_v()); 01755 size_type __bkt = _M_bucket_index(__k, __code); 01756 01757 // Find the node before an equivalent one or use hint if it exists and 01758 // if it is equivalent. 01759 __node_base* __prev 01760 = __builtin_expect(__hint != nullptr, false) 01761 && this->_M_equals(__k, __code, __hint) 01762 ? __hint 01763 : _M_find_before_node(__bkt, __k, __code); 01764 if (__prev) 01765 { 01766 // Insert after the node before the equivalent one. 01767 __node->_M_nxt = __prev->_M_nxt; 01768 __prev->_M_nxt = __node; 01769 if (__builtin_expect(__prev == __hint, false)) 01770 // hint might be the last bucket node, in this case we need to 01771 // update next bucket. 01772 if (__node->_M_nxt 01773 && !this->_M_equals(__k, __code, __node->_M_next())) 01774 { 01775 size_type __next_bkt = _M_bucket_index(__node->_M_next()); 01776 if (__next_bkt != __bkt) 01777 _M_buckets[__next_bkt] = __node; 01778 } 01779 } 01780 else 01781 // The inserted node has no equivalent in the 01782 // hashtable. We must insert the new node at the 01783 // beginning of the bucket to preserve equivalent 01784 // elements' relative positions. 01785 _M_insert_bucket_begin(__bkt, __node); 01786 ++_M_element_count; 01787 return iterator(__node); 01788 } 01789 __catch(...) 01790 { 01791 this->_M_deallocate_node(__node); 01792 __throw_exception_again; 01793 } 01794 } 01795 01796 // Insert v if no element with its key is already present. 01797 template<typename _Key, typename _Value, 01798 typename _Alloc, typename _ExtractKey, typename _Equal, 01799 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01800 typename _Traits> 01801 template<typename _Arg, typename _NodeGenerator> 01802 auto 01803 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01804 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01805 _M_insert(_Arg&& __v, const _NodeGenerator& __node_gen, true_type, 01806 size_type __n_elt) 01807 -> pair<iterator, bool> 01808 { 01809 const key_type& __k = this->_M_extract()(__v); 01810 __hash_code __code = this->_M_hash_code(__k); 01811 size_type __bkt = _M_bucket_index(__k, __code); 01812 01813 __node_type* __n = _M_find_node(__bkt, __k, __code); 01814 if (__n) 01815 return std::make_pair(iterator(__n), false); 01816 01817 __n = __node_gen(std::forward<_Arg>(__v)); 01818 return { _M_insert_unique_node(__bkt, __code, __n, __n_elt), true }; 01819 } 01820 01821 // Insert v unconditionally. 01822 template<typename _Key, typename _Value, 01823 typename _Alloc, typename _ExtractKey, typename _Equal, 01824 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01825 typename _Traits> 01826 template<typename _Arg, typename _NodeGenerator> 01827 auto 01828 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01829 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01830 _M_insert(const_iterator __hint, _Arg&& __v, 01831 const _NodeGenerator& __node_gen, false_type) 01832 -> iterator 01833 { 01834 // First compute the hash code so that we don't do anything if it 01835 // throws. 01836 __hash_code __code = this->_M_hash_code(this->_M_extract()(__v)); 01837 01838 // Second allocate new node so that we don't rehash if it throws. 01839 __node_type* __node = __node_gen(std::forward<_Arg>(__v)); 01840 01841 return _M_insert_multi_node(__hint._M_cur, __code, __node); 01842 } 01843 01844 template<typename _Key, typename _Value, 01845 typename _Alloc, typename _ExtractKey, typename _Equal, 01846 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01847 typename _Traits> 01848 auto 01849 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01850 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01851 erase(const_iterator __it) 01852 -> iterator 01853 { 01854 __node_type* __n = __it._M_cur; 01855 std::size_t __bkt = _M_bucket_index(__n); 01856 01857 // Look for previous node to unlink it from the erased one, this 01858 // is why we need buckets to contain the before begin to make 01859 // this search fast. 01860 __node_base* __prev_n = _M_get_previous_node(__bkt, __n); 01861 return _M_erase(__bkt, __prev_n, __n); 01862 } 01863 01864 template<typename _Key, typename _Value, 01865 typename _Alloc, typename _ExtractKey, typename _Equal, 01866 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01867 typename _Traits> 01868 auto 01869 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01870 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01871 _M_erase(size_type __bkt, __node_base* __prev_n, __node_type* __n) 01872 -> iterator 01873 { 01874 if (__prev_n == _M_buckets[__bkt]) 01875 _M_remove_bucket_begin(__bkt, __n->_M_next(), 01876 __n->_M_nxt ? _M_bucket_index(__n->_M_next()) : 0); 01877 else if (__n->_M_nxt) 01878 { 01879 size_type __next_bkt = _M_bucket_index(__n->_M_next()); 01880 if (__next_bkt != __bkt) 01881 _M_buckets[__next_bkt] = __prev_n; 01882 } 01883 01884 __prev_n->_M_nxt = __n->_M_nxt; 01885 iterator __result(__n->_M_next()); 01886 this->_M_deallocate_node(__n); 01887 --_M_element_count; 01888 01889 return __result; 01890 } 01891 01892 template<typename _Key, typename _Value, 01893 typename _Alloc, typename _ExtractKey, typename _Equal, 01894 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01895 typename _Traits> 01896 auto 01897 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01898 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01899 _M_erase(std::true_type, const key_type& __k) 01900 -> size_type 01901 { 01902 __hash_code __code = this->_M_hash_code(__k); 01903 std::size_t __bkt = _M_bucket_index(__k, __code); 01904 01905 // Look for the node before the first matching node. 01906 __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code); 01907 if (!__prev_n) 01908 return 0; 01909 01910 // We found a matching node, erase it. 01911 __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt); 01912 _M_erase(__bkt, __prev_n, __n); 01913 return 1; 01914 } 01915 01916 template<typename _Key, typename _Value, 01917 typename _Alloc, typename _ExtractKey, typename _Equal, 01918 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01919 typename _Traits> 01920 auto 01921 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01922 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01923 _M_erase(std::false_type, const key_type& __k) 01924 -> size_type 01925 { 01926 __hash_code __code = this->_M_hash_code(__k); 01927 std::size_t __bkt = _M_bucket_index(__k, __code); 01928 01929 // Look for the node before the first matching node. 01930 __node_base* __prev_n = _M_find_before_node(__bkt, __k, __code); 01931 if (!__prev_n) 01932 return 0; 01933 01934 // _GLIBCXX_RESOLVE_LIB_DEFECTS 01935 // 526. Is it undefined if a function in the standard changes 01936 // in parameters? 01937 // We use one loop to find all matching nodes and another to deallocate 01938 // them so that the key stays valid during the first loop. It might be 01939 // invalidated indirectly when destroying nodes. 01940 __node_type* __n = static_cast<__node_type*>(__prev_n->_M_nxt); 01941 __node_type* __n_last = __n; 01942 std::size_t __n_last_bkt = __bkt; 01943 do 01944 { 01945 __n_last = __n_last->_M_next(); 01946 if (!__n_last) 01947 break; 01948 __n_last_bkt = _M_bucket_index(__n_last); 01949 } 01950 while (__n_last_bkt == __bkt && this->_M_equals(__k, __code, __n_last)); 01951 01952 // Deallocate nodes. 01953 size_type __result = 0; 01954 do 01955 { 01956 __node_type* __p = __n->_M_next(); 01957 this->_M_deallocate_node(__n); 01958 __n = __p; 01959 ++__result; 01960 --_M_element_count; 01961 } 01962 while (__n != __n_last); 01963 01964 if (__prev_n == _M_buckets[__bkt]) 01965 _M_remove_bucket_begin(__bkt, __n_last, __n_last_bkt); 01966 else if (__n_last && __n_last_bkt != __bkt) 01967 _M_buckets[__n_last_bkt] = __prev_n; 01968 __prev_n->_M_nxt = __n_last; 01969 return __result; 01970 } 01971 01972 template<typename _Key, typename _Value, 01973 typename _Alloc, typename _ExtractKey, typename _Equal, 01974 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 01975 typename _Traits> 01976 auto 01977 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 01978 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 01979 erase(const_iterator __first, const_iterator __last) 01980 -> iterator 01981 { 01982 __node_type* __n = __first._M_cur; 01983 __node_type* __last_n = __last._M_cur; 01984 if (__n == __last_n) 01985 return iterator(__n); 01986 01987 std::size_t __bkt = _M_bucket_index(__n); 01988 01989 __node_base* __prev_n = _M_get_previous_node(__bkt, __n); 01990 bool __is_bucket_begin = __n == _M_bucket_begin(__bkt); 01991 std::size_t __n_bkt = __bkt; 01992 for (;;) 01993 { 01994 do 01995 { 01996 __node_type* __tmp = __n; 01997 __n = __n->_M_next(); 01998 this->_M_deallocate_node(__tmp); 01999 --_M_element_count; 02000 if (!__n) 02001 break; 02002 __n_bkt = _M_bucket_index(__n); 02003 } 02004 while (__n != __last_n && __n_bkt == __bkt); 02005 if (__is_bucket_begin) 02006 _M_remove_bucket_begin(__bkt, __n, __n_bkt); 02007 if (__n == __last_n) 02008 break; 02009 __is_bucket_begin = true; 02010 __bkt = __n_bkt; 02011 } 02012 02013 if (__n && (__n_bkt != __bkt || __is_bucket_begin)) 02014 _M_buckets[__n_bkt] = __prev_n; 02015 __prev_n->_M_nxt = __n; 02016 return iterator(__n); 02017 } 02018 02019 template<typename _Key, typename _Value, 02020 typename _Alloc, typename _ExtractKey, typename _Equal, 02021 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 02022 typename _Traits> 02023 void 02024 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 02025 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 02026 clear() noexcept 02027 { 02028 this->_M_deallocate_nodes(_M_begin()); 02029 __builtin_memset(_M_buckets, 0, _M_bucket_count * sizeof(__bucket_type)); 02030 _M_element_count = 0; 02031 _M_before_begin._M_nxt = nullptr; 02032 } 02033 02034 template<typename _Key, typename _Value, 02035 typename _Alloc, typename _ExtractKey, typename _Equal, 02036 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 02037 typename _Traits> 02038 void 02039 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 02040 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 02041 rehash(size_type __n) 02042 { 02043 const __rehash_state& __saved_state = _M_rehash_policy._M_state(); 02044 std::size_t __buckets 02045 = std::max(_M_rehash_policy._M_bkt_for_elements(_M_element_count + 1), 02046 __n); 02047 __buckets = _M_rehash_policy._M_next_bkt(__buckets); 02048 02049 if (__buckets != _M_bucket_count) 02050 _M_rehash(__buckets, __saved_state); 02051 else 02052 // No rehash, restore previous state to keep a consistent state. 02053 _M_rehash_policy._M_reset(__saved_state); 02054 } 02055 02056 template<typename _Key, typename _Value, 02057 typename _Alloc, typename _ExtractKey, typename _Equal, 02058 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 02059 typename _Traits> 02060 void 02061 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 02062 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 02063 _M_rehash(size_type __n, const __rehash_state& __state) 02064 { 02065 __try 02066 { 02067 _M_rehash_aux(__n, __unique_keys()); 02068 } 02069 __catch(...) 02070 { 02071 // A failure here means that buckets allocation failed. We only 02072 // have to restore hash policy previous state. 02073 _M_rehash_policy._M_reset(__state); 02074 __throw_exception_again; 02075 } 02076 } 02077 02078 // Rehash when there is no equivalent elements. 02079 template<typename _Key, typename _Value, 02080 typename _Alloc, typename _ExtractKey, typename _Equal, 02081 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 02082 typename _Traits> 02083 void 02084 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 02085 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 02086 _M_rehash_aux(size_type __n, std::true_type) 02087 { 02088 __bucket_type* __new_buckets = _M_allocate_buckets(__n); 02089 __node_type* __p = _M_begin(); 02090 _M_before_begin._M_nxt = nullptr; 02091 std::size_t __bbegin_bkt = 0; 02092 while (__p) 02093 { 02094 __node_type* __next = __p->_M_next(); 02095 std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n); 02096 if (!__new_buckets[__bkt]) 02097 { 02098 __p->_M_nxt = _M_before_begin._M_nxt; 02099 _M_before_begin._M_nxt = __p; 02100 __new_buckets[__bkt] = &_M_before_begin; 02101 if (__p->_M_nxt) 02102 __new_buckets[__bbegin_bkt] = __p; 02103 __bbegin_bkt = __bkt; 02104 } 02105 else 02106 { 02107 __p->_M_nxt = __new_buckets[__bkt]->_M_nxt; 02108 __new_buckets[__bkt]->_M_nxt = __p; 02109 } 02110 __p = __next; 02111 } 02112 02113 _M_deallocate_buckets(); 02114 _M_bucket_count = __n; 02115 _M_buckets = __new_buckets; 02116 } 02117 02118 // Rehash when there can be equivalent elements, preserve their relative 02119 // order. 02120 template<typename _Key, typename _Value, 02121 typename _Alloc, typename _ExtractKey, typename _Equal, 02122 typename _H1, typename _H2, typename _Hash, typename _RehashPolicy, 02123 typename _Traits> 02124 void 02125 _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal, 02126 _H1, _H2, _Hash, _RehashPolicy, _Traits>:: 02127 _M_rehash_aux(size_type __n, std::false_type) 02128 { 02129 __bucket_type* __new_buckets = _M_allocate_buckets(__n); 02130 02131 __node_type* __p = _M_begin(); 02132 _M_before_begin._M_nxt = nullptr; 02133 std::size_t __bbegin_bkt = 0; 02134 std::size_t __prev_bkt = 0; 02135 __node_type* __prev_p = nullptr; 02136 bool __check_bucket = false; 02137 02138 while (__p) 02139 { 02140 __node_type* __next = __p->_M_next(); 02141 std::size_t __bkt = __hash_code_base::_M_bucket_index(__p, __n); 02142 02143 if (__prev_p && __prev_bkt == __bkt) 02144 { 02145 // Previous insert was already in this bucket, we insert after 02146 // the previously inserted one to preserve equivalent elements 02147 // relative order. 02148 __p->_M_nxt = __prev_p->_M_nxt; 02149 __prev_p->_M_nxt = __p; 02150 02151 // Inserting after a node in a bucket require to check that we 02152 // haven't change the bucket last node, in this case next 02153 // bucket containing its before begin node must be updated. We 02154 // schedule a check as soon as we move out of the sequence of 02155 // equivalent nodes to limit the number of checks. 02156 __check_bucket = true; 02157 } 02158 else 02159 { 02160 if (__check_bucket) 02161 { 02162 // Check if we shall update the next bucket because of 02163 // insertions into __prev_bkt bucket. 02164 if (__prev_p->_M_nxt) 02165 { 02166 std::size_t __next_bkt 02167 = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), 02168 __n); 02169 if (__next_bkt != __prev_bkt) 02170 __new_buckets[__next_bkt] = __prev_p; 02171 } 02172 __check_bucket = false; 02173 } 02174 02175 if (!__new_buckets[__bkt]) 02176 { 02177 __p->_M_nxt = _M_before_begin._M_nxt; 02178 _M_before_begin._M_nxt = __p; 02179 __new_buckets[__bkt] = &_M_before_begin; 02180 if (__p->_M_nxt) 02181 __new_buckets[__bbegin_bkt] = __p; 02182 __bbegin_bkt = __bkt; 02183 } 02184 else 02185 { 02186 __p->_M_nxt = __new_buckets[__bkt]->_M_nxt; 02187 __new_buckets[__bkt]->_M_nxt = __p; 02188 } 02189 } 02190 __prev_p = __p; 02191 __prev_bkt = __bkt; 02192 __p = __next; 02193 } 02194 02195 if (__check_bucket && __prev_p->_M_nxt) 02196 { 02197 std::size_t __next_bkt 02198 = __hash_code_base::_M_bucket_index(__prev_p->_M_next(), __n); 02199 if (__next_bkt != __prev_bkt) 02200 __new_buckets[__next_bkt] = __prev_p; 02201 } 02202 02203 _M_deallocate_buckets(); 02204 _M_bucket_count = __n; 02205 _M_buckets = __new_buckets; 02206 } 02207 02208 #if __cplusplus > 201402L 02209 template<typename, typename, typename> class _Hash_merge_helper { }; 02210 #endif // C++17 02211 02212 #if __cpp_deduction_guides >= 201606 02213 // Used to constrain deduction guides 02214 template<typename _Hash> 02215 using _RequireNotAllocatorOrIntegral 02216 = __enable_if_t<!__or_<is_integral<_Hash>, __is_allocator<_Hash>>::value>; 02217 #endif 02218 02219 _GLIBCXX_END_NAMESPACE_VERSION 02220 } // namespace std 02221 02222 #endif // _HASHTABLE_H